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FIELD OF INVENTION
The invention relates to a method and a circuit for synchronizing a receiver for a convolutionally coded reception signal, and in particular to a convolutionally coded QAM reception signal.
RELATED APPLICATIONS
This application claims the benefit of the priority date of German application DE 100 55 658.2, file on Nov. 10, 2000, the contents of which are herein incorporated by reference.
BACKGROUND
For convolutional coding, transmitted digital data symbols are provided with redundancy so that error detection and error correction is made possible at the receive end.
FIG. 1 shows a 64-QAM transmitter as taught in the prior art. The data originating from a data source DQ are coded in a Reed-Solomon coder and interleaved and transmitted, after scrambling in a scrambler V, to a serial/parallel converter S/P that converts the received scrambled serial data stream into six parallel data streams. In a 64-QAM transmitter, 28 bits of the serial data stream are converted, in accordance with the ITUJ.83 data standard for DOCSIS cable modems, by the serial/parallel converter S/P into four data streams of five bits that are transmitted directly via the data lines d 1 -d 4 in uncoded form, to a downstream QAM mapper. Four bits of the received 28 bits are respectively applied to a coder via data bit lines d 5 , d 6 . After coding in a differential precoder (DPC), the four precoded data bits are fed to a binary convolutional coder CC I , CC II (CC=Convolutional Coding).
The convolutional coders C I , C I each have a puncturing circuit P I , P II connected downstream of them. According to the ITUJ.83 standard, in each case convolutional coders CC I , CC II with a code rate r=½ are used, the applied differentially precoded four data bits in the convolutional coder being recoded into eight data bits, five data bits of which are transmitted to the QAM mapper via the data lines d 7 , d 8 by means of the puncturing circuit P. The QAM mapper performs the quadrature-amplitude-modulated output signal, which can assume 64 statuses, from the six parallel data streams applied, and transmits the output signal to a QAM receiver via a transmission channel K.
FIG. 2 shows a 64-QAM transmit signal with in-phase component I and quadrature component Q.
FIG. 3 shows the structure of a convolutional coder CC. The convolutional coder CC has an input E and an output A. The serial data stream applied to the input E is written into a k-bit-wide first stage. For each input bit, n output bits are generated. These bits are linear combinations of the data bits contained in the shift register. The convolutional coder CC shown in FIG. 3 has M stages that each contain k data bits. The input bits are composed of a block of k data bits that are written into the first stage 1 . The data bits of a stage are shifted to the next stage. The data bits of the last stage are extracted or deleted. The code rate r of the convolutional coder CC is k/n.
As in the case of the block codes, redundancy is additionally added during the convolutional coding in order to be able to detect and correct errors. An essential difference between block codes and convolutional coders is that individual data blocks cannot be successively coded in the latter, but rather continuous coding takes place. The current coding of a transmit data sequence depends on the preceding transmit data sequences.
In each case k new transmit data bits are written into the first stage of the convolutional coder per clock cycle. The number M of stages (constrained length) indicates the number of clock cycles of k new data bits over which a written-in data bit influences the code word. The contents of the individual registers are read out by means of logic-operation circuits and added in v modulus 2 adders and subsequently sampled. The type of logic operations comprises the actual coding rule of the convolutional coder CC.
The method of operation of a convolutional coder CC according to the prior art as represented in FIG. 3 will be explained below by means of an example.
The convolutional coder CC illustrated in FIG. 4 has three stages each with a data bit and a coding rate of ½(M=3, k=1, r=½).
The applied transmit data sequence D(x)=(101) is recoded by the convolutional coder CC into the coded output signal sequence C(x)=(1110001011).
In polynomial representation, the convolutional coder illustrated in FIG. 4 can be described as:
G 1 ( x )=1 +x+x 2
G 2 ( x )=1+ x 2
C ( x )= D ( x ) G 1 ( x ) interleaved with D(x)G 2 (x).
FIG. 5 shows a status diagram of the convolutional coder illustrated in FIG. 4 . The M−1 states of the right-hand part of the shift register composed of three bits are represented in the rectangles. Either the crossovers of the dashed or of the continuous diagram lines are passed through depending on the data bit written in per clock cycle.
If the written-in data bit is a logic zero, the crossovers that are illustrated as a continuous line will take place, whereas when a logic one is written in the crossovers represented by broken lines take place.
FIG. 6 shows the associated tree diagram of the convolutional coder CC represented in FIG. 4 . The longer the sequence of data to be transmitted, the more confusing the representation as a tree diagram.
The convolutional rule of a convolutional coder CC is therefore represented in a clearer way than what is referred to as a trellis diagram. FIG. 7 shows the trellis diagram of the convolutional coder CC illustrated in FIG. 4 . The four lines correspond to the states of the right-hand part of the register of the convolutional coder. For each clock there are 2 k branching points. As in the status diagram illustrated in FIG. 5 , when there is a logic zero as input bit the crossover represented as a continuous line takes place, whereas when a logic one is written in the crossover represented as a broken line takes place. The pairs of numbers associated with the lines each indicate the output values of this status crossover. After M clocks, in each case 2 k different branchings converge again.
FIGS. 8 a- 8 h show by way of example the method of operation of a Viterbi decoder for the coding of a convolutionally coded reception signal as used in receivers according to the prior art. In the example illustrated in FIG. 8 a , the Viterbi decoder decodes a convolutionally coded reception signal that has been coded by the convolutional coder CC that is illustrated in FIG. 4 and has the trellis diagram illustrated in FIG. 7 . The transmitted code sequence is Cs(x)=(1101010001) in the example illustrated in FIG. 8 .
The code sequence received by the receiver (with errors) is: CE(x)=(1101011001).
As in the first step illustrated in FIG. 8 a , the first two digits of the received code sequence (11) are compared with the output values of the two trellis branchings. The calculation of the Hamming distance as a metric value yields the value 2 for the upper branching and the value 0 for the lower branching. At the next clock, the Hamming distance between the next digits of the received code sequence (01) and the output values of the now four branchings of the trellis diagram is calculated. FIG. 8 b shows the accumulated metric values that are obtained from the sum of the previous metric value of the path and of the metric value calculated for this step.
The calculation of the metric values for the next two digits is carried out in an analogous fashion. FIG. 8 c shows the calculated result. As can be seen in FIG. 8 c , an end point of in each case two paths now is reached. This is generally the case after M clock pulses. Of these further clock pulses, only that with the lower accumulated metric is used by these two paths for the further calculation. As a result, a significant reduction in the necessary storage requirement in the Viterbi decoder is possible. FIG. 8 c shows the result of this selection.
The following two clocks and the respective selection are illustrated in FIGS. 8 e - 8 h . The path printed in bold in FIG. 8 h represents, for the overall metric one, the path with the lowest metric.
A comparison of this discovered path with the trellis diagram illustrated in FIG. 7 shows that this signal path corresponds to the code sequence (111010001), i.e. to the code sequence Cs(x) that is actually transmitted. The transmit error was implicitly corrected by means of the Viterbi decoder. This error correction took place in the fourth clock pulse (see FIGS. 8 e and 8 f ) in the example shown. The fact that an error was corrected by the Viterbi decoder is apparent from the fact that the overall metric is no longer equal to zero, as was still the case at the third clock pulse, but rather equal to one. By means of the metric value m, an estimate of the error rate is therefore obtained. By means of the calculated metric value, it is thus possible to estimate the connection quality of the transmission channel. If the case occurs that two different paths of an end point yield the same overall metric, it is possible to detect from this that more errors have occurred than can be corrected. The method of operation of a Viterbi decoder is described in IEEE, Vol. 61, No. 3, March 1973 “The Viterbi Algorithm”.
FIG. 9 shows a QAM receiver according to the prior art. The convolutionally coded transmit signal that is output by the 64-QAM transmitter illustrated in FIG. 1 via the transmission channel K is demodulated in an equalizer and the in-phase component I and the quadrature component Q of the QAM transmit signal represented in FIG. 2 are fed to a switching device S. The received data symbols are applied to the input of a Viterbi decoder by the equalizer EQ via the switched data lines. The Viterbi decoder decodes the applied convolutionally coded reception signal and in the process the reception signal sequence is continuously compared with theoretically possible transmit signal sequences, and the degree of correspondence is made the basis of the decision using a static estimation method. The higher value data bits that are output by the Viterbi decoder are fed directly to a parallel/serial converter P/S via four data lines, while the low value data bits are firstly decoded in a differential decoder and then fed to the parallel/serial converter PS. The decoded data is passed on from the output of the parallel/serial converter P/S to any desired data sink DS for further data processing.
In the 64-QAM transmitter illustrated in FIG. 1 , the convolutional coders CC each code bit groups composed of four bits that are applied to the data lines d 5 , d 6 in bit groups composed of five bits that are output to the QAM mapper via data lines d 7 , d 8 . By puncturing the data bit stream that is output by the convolutional coder CC, three QAM data symbols are generated by the QAM mapper based on the first three data bits, while two further QAM data symbols are generated based on the last of the four input data bits. Puncturing at the puncturing circuit P ensures that a data sequence that follows in accordance with the standard ITUJ.83 is output to the QAM mapper by the coder via the data lines d 7 , d 8 :
C(x)=x0, x0, x0, x1, x0.
The QAM mapper thus generates three QAM transmit data symbols by means of three iterations or shift operations of the two convolutional coders. Two QAM symbols are then generated by means of an iteration or a shift operation of the two convolutional coders.
A synchronization operation must therefore take place in the 64-QAM receiver, as illustrated in FIG. 9 , because the three QAM data symbols are to be processed by the Viterbi decoder in a way that differs from that for the next two QAM data symbols.
Therefore, the 64-QAM receiver illustrated in FIG. 9 according to the prior art contains a synchronization circuit. The synchronization circuit is connected to the output of the parallel/serial converter P/S. The data sequence that is output by the parallel/serial converter P/S in the synchronization circuit is compared with a stored known synchronization word data pattern until the synchronization circuit detects correspondence. In the process, a plurality of received data frames are sampled until at least two data frames at the correct data interval contain the known synchronization data word.
However, such a conventional synchronization operation has a number of disadvantages. The synchronization circuit, as illustrated in FIG. 9 , requires a comparator memory for the various synchronization data words FSYNC that differ in a 256-QAM receiver and a 64-QAM receiver. In addition, two different search algorithms must be implemented for sensing the different training sequences. A separate counter is provided for sensing the distance between the transmitted data frames. The distance is different in E4-QAM signals and 256-QAM signals. A further counter counts the number of sensed frames. A further counter must be provided for checking for the resetting operation. Because the transmitted synchronization words are approximately 2 milliseconds apart from one another, the time for the synchronization operation in the conventional 64-QAM receiver illustrated in FIG. 9 is long.
SUMMARY
The object of the present invention is therefore to provide a method and a device that permits fast synchronization of a receiver for convolutionally coded reception signals in a way that is simple in terms of circuitry.
The invention provides a method for synchronizing a receiver for a convolutionally coded reception signal that is composed of a sequence of received data symbols, having the following steps:
the convolutionally coded reception signal is decoded by means of a Viterbi decoder that calculates a minimum metric signal sequence of the reception signal;
the signal values of the metric signal sequence calculated by means of the Viterbi decoder are compared with an adjustable threshold value; and
at least one received data symbol is discarded if the threshold value is exceeded too frequently by the metric signal sequence within a predetermined time period.
The received data symbols are preferably QAM data symbols.
The received QAM data symbols are preferably 64-QAM or 256-QAM data symbols.
The invention also provides a synchronization circuit for a signal receiver for receiving a convolutionally coded reception signal that is composed of a sequence of data symbols, having:
a switching device for switching through the received convolutionally coded data symbols;
a Viterbi decoder for decoding the switched-through data symbols, the Viterbi decoder calculating a minimum metric signal sequence of the reception signal;
a first comparator circuit for comparing the signal values of the calculated metric signal sequence with an adjustable threshold value;
a counter that counts the number of occasions the threshold value is exceeded in a predetermined time period;
a second comparator circuit for comparing the counter reading of the counter with an adjustable counter threshold value and with the second comparator circuit actuating a switching device in such a manner that a received data symbol is suppressed when the counter threshold value is exceeded.
The convolutionally coded reception signal is preferably a convolutionally coded QAM reception signal.
Preferred embodiments of the synchronization method according to the invention and of the synchronization circuit according to the invention will be described below with reference to the appended drawings in order to explain features that are essential to the invention.
BRIEF DESCRIPTION OF THE FIGURES
FIG. 1 shows a 64-QAM transmitter according to the prior art;
FIG. 2 shows a 64-QAM transmit signal;
FIG. 3 shows a convolution coder according to the prior art, contained in a transmitter;
FIG. 4 shows an example of a convolution coder according to the prior art;
FIG. 5 shows a status diagram of the convolution coder illustrated in FIG. 4 ;
FIG. 6 shows a tree diagram of the convolution coder illustrated in FIG. 4 ;
FIG. 7 shows a trellis diagram of the convolution coder illustrated in FIG. 4 ;
FIGS. 8 a - 8 h show diagrams explaining the method of operation of a conventional Viterbi decoder that is installed in a receiver according to the prior art;
FIG. 9 shows a 64-QAM receiver according to the prior art;
FIG. 10 shows a block diagram of QAM receiver according to the invention;
FIG. 11 shows the circuit design of a synchronization circuit according to the invention;
FIG. 12 shows a flowchart of a preferred embodiment of the synchronization method according to the invention;
FIGS. 13 a , 13 b show signal flowcharts of the low signal sequence that is output by the Viterbi decoder within the receiver according to the invention;
FIGS. 14 a , 14 b show the counter value with different signal-to-noise ratios of a preferred embodiment of the synchronization method according to the invention;
FIG. 15 shows a trellis diagram of the convolution coding and decoding such as is used in a preferred embodiment of the method according to the invention.
DETAILED DESCRIPTION
As is apparent from FIG. 10 , the QAM receiver 1 according to the invention contains a signal input 2 for receiving a convolutionally coded reception signal that is transmitted via a transmission channel 3 and is composed of a sequence of data symbols, for example QAM data symbols. The QAM receiver 1 is preferably a 64-QAM receiver or a 256-QAM receiver. The received 64-QAM data symbols are composed of six bits, two bits of which are convolutionally coded. The data symbols are fed via data lines 4 to an equalizer or a demodulator circuit 5 that feeds the in-phase signal component I via a data line 6 to an input 7 of a switching device 8 . The demodulator 5 outputs the quadrature component Q of the QAM-modulated reception signal to a second input 10 of the switching device 8 via a further data line 9 . The switching device 8 contains two controllable switches 11 , 12 that are actuated by a synchronization circuit 14 via control lines 13 . The switching device 8 has a first signal input 15 that is connected via a signal line 16 to a first input 17 of a Viterbi decoder 18 . The Viterbi decoder 18 receives via the signal input 17 the switched-through in-phase component I of the received quadrature-amplitude-modulated reception signal.
The switching device 8 has a signal output 19 that is connected via a line 20 to a second input 21 Of the Viterbi decoder 18 The Viterbi decoder 18 receives the quadrature component Q of the reception signal via the signal input 21 . The Viterbi decoder 18 carries out decoding of the QAM data symbols switched through by the switching device 8 , the Viterbi decoder 18 calculating, during the decoding operation, a signal sequence of minimum metric values for detecting the optimum path within the trellis diagram. The Viterbi decoder 18 outputs the calculated signal sequence of minimum metric values of the QAM reception signal via an output 22 , and to the synchronization circuit 14 via a line 23 . The synchronization circuit 14 evaluates the received metric signal and actuates the switching device 8 via the control line 13 as a function of the received metric signal.
The Viterbi decoder 18 of the 64-QAM receiver according to the invention that is illustrated in FIG. 10 has six signal outputs 24 - 29 , the four signal outputs 24 - 27 for the non-precoded data bits being transmitted directly via associated data lines 30 - 33 to a parallel/serial converter 34 . The precoded data bits are firstly decoded by a differential decoder 35 and then also transmitted to the parallel/serial converter 34 via lines 36 , 37 . The parallel/serial converter 34 converts the parallel data streams present at the six inputs into a serial data stream and outputs it via a line 38 to a serial data output 39 of the QAM receiver 1 . The serial data output 39 of the QAM receiver 1 is connected via a data line 40 , a deinterleaver, a descrambler and a Reed-Solomon decoder to any desired data sink 41 for further data processing of the decoded data.
FIG. 11 shows the circuit design of the synchronization circuit 14 illustrated in FIG. 10 . The synchronization circuit 14 has a control input 42 for receiving the metric signal that is output by the Viterbi decoder 18 . The input 42 of the synchronization circuit 40 is connected via a signal line 43 to the input 44 of a first comparator circuit 45 . The first comparator circuit 45 compares the applied signal values of the calculated metric signal sequence with an adjustable threshold value that can be adjusted by means of an adjustment line 46 and an adjustment terminal 47 of the synchronization circuit 14 . The first comparator circuit 45 has a control output 48 that is connected via a control line 49 to an input 50 of a counter 51 . The counter counts the number of occasions when the threshold value is exceeded within a predetermined time period. The counter 51 can be reset by means of a resetting line 52 and a resetting terminal 53 . The counter 51 is connected at the output end to an input 56 of a second comparator circuit 57 via a counter output 54 and a line 55 , the comparator circuit 57 comparing the counter reading at the output of the counter 51 with an adjustable counter place value. The counter place value can be adjusted by means of an adjustment line 58 and an adjustment terminal 59 of the synchronization circuit 14 . The second comparator circuit 57 has a control output 60 that is connected via a line 61 to a control output 62 of the synchronization circuit 14 The control output 62 Of the synchronization circuit 14 controls the switching device 8 illustrated in FIG. 10 via the control line 13 .
FIG. 12 shows a flowchart of the preferred embodiment of the synchronization method according to the invention.
In a step S 0 , a timing counter is initialized. For example, 2048 QAM data symbols are to be checked at the signal output 24 - 29 of the Viterbi decoder 18 , this corresponding to 2560 received QAM data symbols. The time period required for this is approximately 0.5 milliseconds.
In a step S 1 , the metric value applied to the signal input 42 of the synchronization circuit 14 is read in and in a step S 2 it is checked whether the calculated metric value exceeds a specific adjustable threshold value. The threshold value is, for example, eight so that the first comparator circuit 45 only has to check the three highest order bits MSB of the applied metric signal.
If the threshold value is exceeded, in a step S 3 the counter 51 within the synchronization circuit 14 is incremented and this system moves on to step S 4 . If the threshold value is not exceeded by the applied metric value, the system moves from step S 2 directly to step S 4 .
In step S 4 it is checked whether or not the timing counter initialized in step S 0 has expired. If the timing counter, which is preferably implemented as a decrementing counter, has not yet expired, it is decremented in step S 5 .
If the time period that is to be monitored has expired and the timing counter has reached the value 0, in step S 6 , the counter reading of the counter 51 is read out and compared with a counter threshold value that can be counted in. If the counter has reached the maximum counter threshold value (and has then overflowed), the synchronization circuit 14 detects that synchronization has not yet been achieved, and in a step S 7 the comparator circuit 57 actuates the switching device 8 in such a way that an applied QAM data symbol is discarded or suppressed.
If the maximum permitted counter reading has not yet been reached, in step S 6 it is decided that synchronization has already taken place and the sequence goes directly on to step S 8
In step S 8 , the counter 51 within the synchronization circuit 14 is reset to zero, and the timing counter is set to the maximum time. The sequence then returns to step S 1 .
FIGS. 13 a , 13 b show the metric signals that are output by the Viterbi decoder 18 , for different signal-to-noise ratios SNR on the transmission channel 3 . In the examples shown in FIGS. 13 a , 13 b , there is no synchronization for the first 2000 received data symbols synchronization has taken place for the following 5000 data symbols. The examples shown in the two FIGS. 13 a , 13 b relate to a 256-QAM receiver with a poor signal-to-noise ratio of 29 dB and a good signal-to-noise ratio of 39 dB. As is apparent from the two FIGS. 13 a , 13 b , the mean value of the metric signal with a large degree of noise on the transmission channel is greater than with a small degree of noise. The data symbols with the highest metric values are the consequence of incorrect synchronization, and the influence of the noise on these data symbols is weak.
FIG. 14 shows the value profile of the counter 51 within the synchronization circuit 14 for the cases shown in FIGS. 13 a , 13 b . As is apparent from comparison of the two counter profiles, the different between the counter values with a good signal-to-noise ratio SNR of the transmission channel 3 and with a poor signal-to-noise ratio SNR of the transmission channel 3 is almost identical. The counter 51 exceeds the error threshold value 15 if no synchronization or alignment is achieved and assumes very low values if the QAM receiver is synchronized to the reception signal.
FIG. 15 shows an example of a trellis diagram such as is used by the Viterbi decoder 18 , illustrated in FIG. 10 , for transmitting the metric signal.
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A method for synchronizing a receiver for a convolutionally coded reception signal having a sequence of received data symbols includes decoding the convolutionally coded reception signal by means of a Viterbi decoder that calculates a minimum metric signal sequence. The metric signal sequence is then compared with an adjustable threshold value. If metric signal exceeds the threshold value too frequently during a predetermined time period, at least one received data symbol is discarded.
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BACKGROUND OF THE INVENTION
[0001] 1. Field of the Invention
[0002] The present invention relates to an outlet switch socket device; in particular, to an outlet switch socket device allowing both electronic device power control and electronic device function control features.
[0003] 2. Description of Related Art
[0004] Currently available remote controls for controlling the functions of various types of audio-video switch socket device mostly use Infra-Red (IR) technology to perform wireless remote control. However, due to poor penetration of IR beam and directional limit, the emitter in the IR remote control needs to be substantially aimed at the IR receiver installed in the audio-video switch socket device so as to achieve the purpose of IR remote control. Therefore, in case that it is needed to remotely control a distant IR audio-video switch socket device, the IR technology may not be able to successfully meet such a requirement. Besides, there at present also exists a type of Radio Frequency (RF) remote control, which presents better radio penetration feature without undesirable directional limits, thus very suitable for the use as the remote control function.
[0005] In general, a common remote controlled outlet switch socket device comprises a receiver, which receives a control signal emitted from some remote device. Then, the socket on the remote controlled outlet switch socket device is under the control of the control signal to be set as conducting or not; thereby, the remote controlled outlet switch socket device may control whether to supply power to the electronic device plugged to the socket, further operating the power ON/OFF of such a plugged device. However, the aforementioned remote controlled outlet switch socket device can only control whether to supply power to the electronic device, but is still unable to control operations of other functions of the electronic device.
[0006] Accordingly, it is desirable for the industry to provide an outlet switch socket device allowing both electronic device power control and electronic device function control.
SUMMARY OF THE INVENTION
[0007] The present invention provides an outlet switch socket, which receives the Radio Frequency (RF) wireless remote control and further controls peripheral Infra-Red (IR) electronic devices based on the RF wireless remote control and by using IR technology. As such, the outlet switch socket device according to the present invention is allowed to control not only whether to supply power to the IR electronic device but, meanwhile, various functions thereof.
[0008] The outlet switch socket device according to a preferred embodiment of the present invention is controlled by a control signal, comprising: a plug, at least one socket, at least one switch, a power converter, a communication module, a microprocessor and an IR module. Herein the plug is used to receive an alternative current (AC) power. Each of the at least one switch is respectively connected in series between each corresponding socket and the plug. The power converter is coupled to the plug and used to convert the AC power into a direct current (DC) power. The communication module is used to receive a control signal. The microprocessor is coupled to the communication module, the power converter and the at least one switch to use the DC power, controlling the enable or disable of such switches based on the control signal and transferring the control signal to the IR module. The IR module is coupled to the microprocessor and emits an IR signal to an IR electronic device based on the control signal.
[0009] In summary, the outlet switch socket device according to the present invention combines the technologies of RF wireless remote control and IR control to remotely control an IR electronic device at a distance, thus providing both the control over power supply to the IR electronic device as well as the control over various functions of the IR electronic device. In this way, the present invention is allowed to effectively eliminate the drawback that conventional remote controlled outlet switch socket device can only control the power supply to the electronic device, but is unable to control other features thereof.
[0010] The summary introduced hereinbefore and detailed descriptions illustrated hereinafter are simply exemplary and addressed to further facilitate understanding in depth for the claimed scope of the present invention. Other objectives and advantages of the present invention will be thoroughly construed in the following descriptions and drawings.
BRIEF DESCRIPTION OF THE DRAWINGS
[0011] FIG. 1 is a circuit block diagram for the outlet switch socket device of a first preferred embodiment according to the present invention;
[0012] FIG. 2 is an application diagram for the outlet switch socket device of the first preferred embodiment according to the present invention;
[0013] FIG. 3 is a circuit block diagram for the outlet switch socket device of a second preferred embodiment according to the present invention; and
[0014] FIG. 4 is an application diagram for the outlet switch socket device of the second preferred embodiment according to the present invention.
DETAILED DESCRIPTION OF PREFERRED EMBODIMENTS
[0015] Refer now to FIG. 1 , wherein a circuit block diagram for the outlet switch socket device of a first preferred embodiment according to the present invention is shown. Herein the outlet switch socket device 1 comprises a plug 10 , at least one socket 142 , at least one switch SW 1 ˜SWn, a power converter 19 , a communication module 13 , a microprocessor 11 and an IR module 15 . Herein the plug 10 is used to receive an AC power, and each of the at least one switch SW 1 ˜SWn is respectively connected in series between each corresponding socket 142 and the plug 10 .
[0016] Referring again to FIG. 1 , the power converter 19 in the outlet switch socket device 1 is coupled to the plug 10 , used to convert the alternative current (AC) power into a direct current (DC) power for the use by the microprocessor 11 . The communication module 13 is a radio transceiver module which receives a control signal S 1 from a remote control (not shown) in a RF wireless fashion, and transfers the received control signal S 1 to the microprocessor 11 . The microprocessor 11 is coupled to the communication module 13 , the power converter 19 and the switches SW 1 ˜SWn, in which the microprocessor 11 receives the DC power, decodes the received control signal S 1 , and then controls the enable or disable of such switches SW 1 ˜SWn based on the decoded control signal S 1 , further controlling whether to supply power to the load. The aforementioned switches SW 1 ˜SWn each may be a relay or a TRIodes AC (TRIAC) switch.
[0017] Referring once again to FIG. 1 , additionally, after decoding the control signal SI by the microprocessor 11 , it is further transferred to the IR module 15 . The IR module 15 emits an IR signal S 2 to an IR electronic device (not shown) based on the decoded control signal S 1 to control the IR electronic device to perform functional operations. Meanwhile, the microprocessor 11 in the outlet switch socket device 1 may also acquire the operation status of the IR electronic device through the IR module 15 , and send the acquired operation status to a distant remote control (not shown) via the communication module 13 . Thereby, the user may observe the operation status in the IR electronic device through the display (not shown) installed on the remote control. Referring yet once again to FIG. 1 , in order to prevent the problems of surge and electromagnetic interference, the outlet switch socket device 1 is further installed with a surge protection circuit 16 , the surge protection circuit 16 being connected in series between the plug 10 and such switches SW 1 ˜SWn. At the same time, the outlet switch socket device 1 in the second (first?) preferred embodiment is also further installed with an electromagnetic interference protection circuit 17 , the electromagnetic interference protection circuit 17 being connected in series between the plug 10 and such switches SW 1 ˜SWn.
[0018] In conjunction with FIG. 1 , refer now to FIG. 2 , wherein an application diagram for the outlet switch socket device of the first preferred embodiment according to the present invention is shown. In FIG. 2 , the outlet switch socket device 1 according to the present invention is illustrated in a form of an extension line. Similarly, the outlet switch socket device 1 according to the present invention may also be implemented in a form of wall-tap typed socket. As such, FIG. 2 simply illustrates the application examples of the first preferred embodiment according to the present invention which is irrelevant to the definition regarding to the scope of the present invention.
[0019] Referring again to FIG. 2 , the outlet switch socket device 1 comprises a plug 10 , an extension line 12 and a body 14 ; herein, on the body 14 there install multiple sockets 142 and a switch 144 . All sockets 142 on the body 14 can be controlled by the switch 144 , and once the switch 144 is turned on, the AC power is conduced to the plug 10 and sent to each socket 142 thereon through the extension line 12 and the conducted switch 144 to allow the use by various loads.
[0020] Meanwhile, in the outlet switch socket device 1 , there also includes a communication module 13 , a microprocessor 11 and an IR module 15 ; herein the communication module 13 builds wireless communications with a distant remote control 2 in a RF wireless fashion. Besides, the microprocessor 11 in the outlet switch socket device 1 is coupled to the communication module 13 and the IR module 15 , wherein the microprocessor 11 acquires through the communication module 13 the control signal S 1 emitted from the remote control 2 , decodes the acquired control signal S 1 , and then transfers the decoded control signal S 1 to the IR module 15 . Next, the IR module 15 sends an IR signal S 2 to an IR electronic device 3 by way of an IR cable 152 . At the same time, the microprocessor 11 decodes the control signal S 1 , and uses the decoded control signal S 1 to control such sockets 142 whether to power the load.
[0021] In this way, the user is allowed to perform functional operations on the IR electronic device by using the remote control 2 through the outlet switch socket device 1 according to the present invention. Meanwhile, by means of bi-directional wireless communication with the communication module 13 , the remote control 2 is allowed to acquire the operation status in the IR electronic device 3 through the outlet switch socket device 1 according to the present invention. Additionally, the multiple sockets 142 installed on the outlet switch socket device 1 according to the present invention can be controlled by the control signal S 1 emitted by the remote control 2 as well, thus enabling further control over power supply for the use by the load.
[0022] In conjunction with FIG. 1 , refer now to FIG. 3 , wherein a circuit block diagram for the outlet switch socket device of a second preferred embodiment according to the present invention is shown. The same components shown in both the second preferred embodiment and the first preferred embodiment are designated with the identical reference numbers. The second preferred embodiment and the first preferred embodiment can effectively equivalent, the major differences lie in that: the outlet switch socket device 1 ′ in the second preferred embodiment further comprises a communication interface 18 , in which the communication interface 18 is coupled to the communication module 13 and exemplified as a RJ-45 communication interface.
[0023] In conjunction with FIG. 3 , refer next to FIG. 4 , wherein an application diagram for the outlet switch socket device of the second preferred embodiment according to the present invention is shown. In FIG. 4 , the outlet switch socket device 1 ′ according to the present invention is in a form of extension line as an example. Similarly, the outlet switch socket device 1 ′ according to the present invention may also take a form of wall-tap type. As such, FIG. 4 simply illustrates the application examples of the second preferred embodiment according to the present invention which is irrelevant to the definition regarding to the scope of the present invention.
[0024] In FIG. 4 , the communication module 13 of the outlet switch socket device 1 ′ is coupled to the RJ-45 communication interface 18 , the RJ-45 communication interface 18 being connected to a computer device 4 via Internet 5 . The computer device 4 transfers the control signal S 1 to the communication module 13 through Internet 5 and the RJ-45 communication interface 18 . Then, the microprocessor 11 acquires the control signal S 1 from the communication module 13 , decodes the acquired control signal S 1 and transfers to the IR module 15 . Subsequently, the IR module 15 transfers an IR signal S 2 to the IR electronic device 3 through an IR cable 152 . Besides, the microprocessor 11 at the same time decodes the control signal S 1 and controls such sockets 142 whether to supply power to the load based on the decoded control signal S 1 .
[0025] In the way, the user is allowed to perform functional operations on the IR electronic device 3 by using the computer device 4 through the outlet switch socket device 1 ′ according to the present invention. Meanwhile, the computer device 4 is also allowed to acquire the operation status in the IR electronic device 3 by means of the outlet switch socket device 1 ′ according to the present invention. Also, the multiple sockets installed on the outlet switch socket device 1 ′ according to the present invention are controlled by the control signal S 1 from the computer device 4 , thus enabling further control over power supply for the use by the load.
[0026] In summary, the outlet switch socket device according to the present invention uses wireless remote control transceiving features, in combination with surge protection circuit, to provide an IR electronic device plugged in the outlet switch socket device with a stable and surge-protected power source.
[0027] Furthermore, the outlet switch socket device according to the present invention uses the built-in wireless communication module to receive the control signal outputted by a distant remote control, which control signal being decoded and transferred to the IR module, and therein the IR module emitting an IR signal based on the decoded control signal to control the IR electronic device.
[0028] Also, in addition to use of radio distant remote control, it is also possible to internally install a RJ-45 communication interface in the outlet switch socket device according to the present invention, allowing to link with a remote computer device via Internet. In this way, as the computer device is connected to the network, it is possible to use dedicated software executed on the computer device to issue control signals to the outlet switch socket device according to the present invention through Internet. Then the outlet switch socket device according to the present invention controls the IR electronic device via the IR module.
[0029] Thus, the outlet switch socket device according to the present invention combines the function of radio transmission/reception and provides IR connection to the IR electronic device required to be controlled remotely. In addition to provision of power supply that the IR electronic device needs, it is also possible to provide radio transmission/reception feature and ability of network remote control through the RJ-45 communication interface. The outlet switch socket device according to the present invention is not limited in terms of perspective or form thereof, but, based on the actual application environment, can be implemented in accordance with various shapes or forms, e.g. Strip, Wall-Tap, Rack-Mount and the like.
[0030] The aforementioned descriptions simply illustrate the preferred embodiments of the present invention, but the characteristics of the present invention are by no means limited thereto. All changes or modifications that skilled ones in the art can conveniently consider in the field of the present invention are deemed to be encompassed by the scope of the present invention delineated by the following claims.
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An outlet switch socket device includes a plug, at least one socket, at least one switch, a power converter, a communication module, a microprocessor and an infrared module. Moreover, the plug is used to receive an alternating current. Each switch is respectively coupled between each corresponding socket and the plug. The power converter is coupled to the plug and converts the alternating current into a direct current, thereby supplying the direct current to the microprocessor. Moreover, the microprocessor receives the direct current from the power converter and receives a control signal from a remote control via the communication module. Furthermore, the microprocessor is used to control those switches according to the control signal and transmits the control signal to the infrared module. The infrared module is used to output an infrared signal to control an infrared device.
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CROSS REFERENCE TO RELATED APPLICATIONS
This application is the US National Stage of International Application No. PCT/EP2004/008357, filed Jul. 26, 2004 and claims the benefit thereof. The International Application claims the benefits of European Patent application No. EP03019093.8 filed Aug. 22, 2003. All of the applications are incorporated by reference herein in their entirety.
FIELD OF THE INVENTION
The invention relates to a heat shield block, in particular for lining a combustion chamber wall, having a hot side that can be impinged upon by a hot medium and a wall side situated opposite the hot side, and having a core area which extends from the hot side to the wall side and has a core material. The invention relates further to a combustion chamber having an inner combustion chamber lining and to a gas turbine.
BACKGROUND OF THE INVENTION
A thermally and/or thermo-mechanically highly stressed combustion space such as, for instance, a furnace, a hot gas duct or a combustion chamber in a gas turbine in which space a hot medium is produced and/or ducted is provided with a suitable lining as a protection against excessive thermal stressing. Said lining consists usually of a heat-resistant material and protects a wall of the combustion space from direct contact with the hot medium and the heavy thermal stressing associated therewith.
U.S. Pat. No. 4,840,131 relates to the securing of ceramic lining elements to a wall of a furnace or kiln, with a system of rails being secured to said wall. The lining elements are rectangular in shape with a planar surface and consist of a heat-insulating, fireproof, ceramic fibrous material.
U.S. Pat. No. 4,835,831 relates likewise to the affixing of a fireproof lining to a furnace wall, in particular a vertically arranged wall. A layer consisting of glass, ceramic, or mineral fibers is affixed to the metallic wall of the furnace. Said layer is secured to the wall by means of metallic hook members or by adhesive means. Wire netting having . . . —shaped meshing is affixed to said layer. The meshed netting serves also to prevent the ceramic-fiber layer from dropping. An even, closed surface of fireproof material is additionally applied secured by means of a bolt. The rebounding of fireproof particles formed during spraying, as would occur were the fireproof particles sprayed onto the metallic wall directly, will substantially be avoided as a result of applying the method described.
A ceramic lining of the walls of thermally highly stressed combustion spaces, for example of gas turbine combustion chambers, is described in EP 0 724 116 A2. The lining consists of wall elements made of high-temperature resistant structural ceramic material such as, for example, silicon carbide (SeC) or silicon nitrite (Si 3 N 4 ). The wall elements are fastened mechanically and resiliently to a metallic supporting structure (wall) of the combustion chamber by means of a central fastening bolt. A thick thermal insulating layer is provided between the wall element and the wall of the combustion space so that the wall element is correspondingly distanced from the wall of the combustion chamber. The insulating layer, which is about three times as thick as the wall element, consists of ceramic fibrous material prefabricated in blocks. The wall elements can be accommodated in terms of their dimensions and external shape to the geometry of the space requiring to be lined. Another kind of lining for a thermally highly stressed combustion space is described in EP 0 419 787 B1. The lining consists of heat shield elements secured mechanically to a metallic wall of the combustion space. The heat shield elements are in direct contact with the metallic wall. To avoid excessive heating of the wall resulting from, for instance, a direct transfer of heat from the heat shield element or the ingress of hot medium into the gaps formed by the mutually abutting heat shield elements, the space formed by the wall of the combustion space and the heat shield element is exposed to cooling air, termed barrier air. Said barrier air prevents hot medium from penetrating as far as the wall and simultaneously cools the wall and the heat shield element.
WO 99/47874 relates to a wall segment for a combustion chamber and to a combustion chamber of a gas turbine. Described therein is a wall segment for a combustion chamber, which can be impinged upon by a hot fluid, for example a hot gas, having a metal support structure and a heat protection element secured thereon. Fitted between said metal support structure and said heat protection element is a deformable separating layer whose purpose is to absorb and compensate for possible relative movements of the heat shield element and support structure. Such relative movements can be caused, for example, in the combustion chamber of a gas turbine, in particular an annular combustion chamber, by the materials used having different thermal expansion characteristics or by pulsations in the combustion area that can occur in the event of irregular combustion to produce the hot working medium or as a result of resonant effects. At the same time the separating layer results in the relatively inelastic heat protection element overall lying flatter on the separating layer and metallic support structure because the heat protection element penetrates in places into the separating layer. The separating layer can thus also compensate for irregularities, due to production effects, on the support structure and/or heat protection element, which can lead to the disadvantageous introduction of forces at specific points, locally.
Particularly in the case of walls of high-temperature gas reactors such as, for example, gas turbine combustion chambers operated under pressure, their supporting structures have to be protected by means of suitable combustion chamber linings against an attack by hot gas. Owing to their high temperature stability, corrosion resistance, and low thermal conductivity, ceramic materials are ideal candidates for this compared to metallic materials. Owing to thermal expansion properties that are typical of materials and cause movement in the presence of differences in temperature (ambient temperature when stopped, maximum temperature when fully loaded) typically occurring during operation, the thermal mobility of ceramic heat shields resulting from temperature-dependent expansion has to be accommodated to obviate the occurrence of thermal stress which obstructing expansion causes and can lead to component destruction. This can be achieved by lining the wall requiring to be protected from hot gas attack with a plurality of individual, size-limited ceramic heat shields, for example heat shield blocks made of fireproof ceramic: As already discussed above in connection with EP 0 419 487 B1, suitable expansion gaps which, as explained, must for safety reasons never be completely closed even in the hot condition must be provided between the individual ceramic heat shield elements. It must at the same time be ensured that the hot gas does not excessively heat the supporting wall structure via the expansion gap. The simplest and surest way to avoid this in a gas turbine combustion chamber is to flush the expansion gap with air, by a process termed barrier-air cooling. The air required in any event for cooling mounting elements for the ceramic heat shields can be used for that purpose.
WO 02/25173 A1 discloses a heat shield brick, in particular for lining a combustion chamber wall, comprising a hot side that can be exposed to a hot medium, a wall side that lies opposite the hot side, and a peripheral side that lies adjacent to the hot side and the wall side and that has a peripheral lateral face. A tensioning element, pre-stressed in the peripheral direction, is provided on the peripheral side, whereby a compressive stress is generated perpendicularly to the peripheral lateral face. Extremely efficient and long-lasting protection for a heat shield brick is indicated thereby. The tensioning element is pre-stressed in the peripheral direction, whereby a certain compressive stress is generated perpendicularly to the peripheral lateral face. The heat shield brick is secured by this normal force, which is directed toward the interior of the heat shield brick at its center, even when the normal forces are very small. An incipient crack in the material, resulting from, for instance, impact loading, will be effectively counteracted thereby. Given a suitably arranged and embodied tensioning element, any incipient cracks present in the material will not, or only to a limited extent, be able to develop further or expand. The tensioning element holds the heat shield brick together, as it were, and protects it on the one hand from incipient cracking and, on the other, primarily from cracking through completely. The danger of smaller or larger fragments becoming loose or dropping out in the possible event of complete cracking through is additionally effectively counteracted.
SUMMARY OF THE INVENTION
The object of the invention is to disclose a heat shield block ensuring a high level of operational reliability and long tool life in terms both of unrestricted thermal expansion and of its resistance to a hot gas attack. Further objects of the invention are to disclose a combustion chamber having an inner combustion chamber lining and to disclose a gas turbine having a combustion chamber.
The object relating to the heat shield block is inventively achieved by means of a heat shield block, in particular for lining a combustion chamber wall, having a hot side that can be impinged upon by a hot medium and a wall side situated opposite the hot side, and having a core area which extends from the hot side to the wall side and has a core material, with the core area being surrounded by an edge area having an edge material whose thermal conductivity is lower than the core material's.
The invention already proceeds here from the knowledge that as a result of the air current cooling the edges of the heat shield block and flowing through the gap between the heat shield blocks and of the transfer of heat to the hot side of the heat shield block as a result of the impinging thereon of hot gas, a three-dimensional temperature distribution will in individual cases occur within the heat shield block. This is characterized by a drop in temperature from the hot side to the wall side and, as a result of the barrier-air cooling of the edges (“edge cooling”), from central points in the ceramic heat shield block toward the cooled edges. In the case of heat shield blocks typically flat parallel to the hot side or, as the case may be, wall side the temperature gradient perpendicular to the wall-side surface will result in comparatively only slight thermal stresses provided nothing impedes the thermally induced arching of the heat shield block in its mounted condition. Conversely, a temperature gradient that is parallel—proceeding from an edge toward an inner area of the heat shield block—to the wall side will result very readily in increased thermal stresses owing to the mechanical rigidity of plate-like geometries in terms of deformations parallel to their size-projection areas. Owing to their comparatively low thermal expansion, cold edges are here put under tension by hotter central areas, which undergo greater thermal expansion; that can lead to the formation of cracks, starting at the edges of the heat shield block, if the material's strength is exceeded.
The invention discloses a totally novel concept, in particular for avoiding a failure of the heat shield block ensuing from the problem of crack formation starting at the edges of the heat shield block. In doing so the invention makes use of the knowledge that thermally induced tensile stresses as a rule only occur where there are temperature gradients. If temperature gradients starting at the edges of the heat shield block are prevented from penetrating deep into the interior of the heat shield block, any cracks occasioned thereby will only be able to penetrate to a limited extent or, as the case may be, cracks will not form at all. Short cracks that start at the edges and extend only slightly toward the interior of the heat shield block will be tolerated because they will not impair the functioning capability of the heat shield block either theoretically or as shown by practical experience.
The invention provides a heat shield block whose thermal conductivity is selectively set locally for avoiding the formation and growth of cracks. The core area is or for this purpose surrounded by an edge area having an edge material whose thermal conductivity is lower than the core material's. A two-material heat shield block is therefore disclosed having thermal insulation in the edge area which, owing to the targeted choice of material for the edge material, has reduced thermal conductivity compared to the core material. The core area and edge area are herein integral parts of the heat shield block so that a heat shield block is provided having thermal conductivity that can be varied via its volume. What is achieved by having the greater thermal conductivity in the core area is that a temperature profile that is approximately balanced parallel to the hot side arises in the core area. The core area thus remains substantially free of thermal stress. Temperature gradients and thermal stresses associated therewith occur only in the edge area.
The edge area herein advantageously also includes the outer edges of the heat shield block so that, owing to the lower thermal conductivity compared to the core area, these act as thermal insulation or, as the case may be, an insulating area. It is of particular advantage herein that the length of cracks due to thermal stresses is shortened because such cracks are limited to the edge area, as a result of which the heat shield block is stabilized in terms of crack formation.
In a preferred embodiment of the heat shield block the thermal conductivity of the edge material is less than 60%, in particular less than 50%, of the thermal conductivity of the core material. The heat shield block is accordingly embodied in such a way that a significant drop in thermal conductivity can be observed at the transition from the core area to the edge area. The edge area acts therein as thermal insulation surrounding the core area. The edge area therein advantageously encloses the core area directly, with a materially coherent bond being realized from the core material and edge material.
The edge material is preferably porous, with the porosity of said material being selectively set in such a way that the thermal conductivity of the edge material is thereby reduced compared to that of the core material. Via the density distribution and size distribution of the pore structure of the edge material, the thermal conductivity can be selectively set in the edge area depending on what is required during loading. Where applicable, varying of the local thermal conductivity can also be achieved within the edge area by appropriately varying the pore size and pore diameter distribution.
In a particularly preferred embodiment the core material and edge material are formed from the same ceramic base material, in particular a fireproof ceramic material. Particularly good material coherence between the core material and edge material can be achieved through said material identicality of the base material. The admixing of pore-forming materials with the base material while the heat shield block is being produced can, for example, be provided to achieve the desired porous structure within the edge area, with said pore-forming material being advantageously pressed or poured into the area close to the edge, which is to say into the edge area of the block being produced. The pore-forming material evaporates during sintering, leaving behind the pores that will appropriately reduce the base material's effective thermal conductivity. Said pore-forming material is preferably not applied to the core area so that the desired reduction in thermal conductivity at the transition from the core area to the edge area will result.
In an advantageous embodiment the axial extent of the edge area along the hot side of the heat shield block is less than 20%, in particular between around 5% and 10%, of the total axial extent of the heat shield block. The heat shield block is in particular provided at all edges that are included in the edge area and have low thermal conductivity differing from the core material's with a reduction in thermal conductivity compared to that of the core area to less than 50% of the core material's thermal conductivity at a spacing somewhat less than 10% of the respective overall extent (support length).
The edge area preferably extends from the hot side to the wall side. The core area is in this embodiment fully encompassed around its circumference by the edge area so that fully circumferential thermal insulation of the core area is achieved with material coherence being realized between the core material and edge material.
The heat shield block preferably has a peripheral side which abuts the hot side and wall side and has a peripheral lateral face formed at least partially from the edge material. In an arrangement of a plurality of heat shield blocks required for lining a combustion chamber wall the gaps between the heat shield blocks are at least partially limited by the edge material on the peripheral lateral face. The peripheral lateral face is advantageously formed completely by the core material so that as good as possible thermal insulation of the core material is provided.
The heat shield block consists preferably of a ceramic base material, in particular a fireproof ceramic material. Choosing a ceramic as the base material for the heat shield block means the heat shield block can safely be used up to very high temperatures, with oxidative and/or corrosive attacks such as occur when the hot side of the heat shield block is impinged upon by a hot medium, for example a hot gas, being at the same time very substantially non-damaging for the heat shield block. This is of particularly major advantage when the heat shield block is used in a combustion chamber because the heat shield block's heat shield function will continue to be maintained even after incipient cracking of the material in the edge area; in particular failure of the heat shield block, for example its complete breakage, will be reliably avoided so that no fragments will be able to reach into the combustion chamber, either.
In economic terms the advantage ensuing therefrom is, on the one hand, that no extraordinary maintenance and/or inspecting of a combustion chamber having the heat shield block will be required in cases of normal operation; on the other hand, in the event of exceptional incidents the heat shield block has emergency running properties so that consequential damage to a turbine, for example to its blade assembly, can be avoided since crack spreading will extensively be prevented thanks to the selective setting of the thermal conductivity in different areas of the heat shield block.
The combustion chamber can be operated applying at least the customary maintenance cycles, moreover with the exposure times being extendible owing to the lower tendency for cracks to spread.
The object relating to a combustion chamber is inventively achieved by means of a combustion chamber having an inner combustion chamber lining having the heat shield blocks according to the explanations.
The object relating to a gas turbine is inventively achieved by means of a gas turbine having a combustion chamber of said type.
The advantages of a combustion chamber of said type or a gas turbine of said type emerge in keeping with the explanations pertaining to the heat shield block.
BRIEF DESCRIPTION OF THE DRAWINGS
The invention is explained in more detail in an exemplary manner with reference to the drawings, in which, in a schematic and in part simplified representation:
FIG. 1 is a cross-sectional view of a gas turbine,
FIG. 2 is a perspective view of a heat shield block,
FIG. 3 is a sectional view of the heat shield block shown in FIG. 2 along the intersection III-III.
FIGS. 4 to 7 show different embodiments of a heat shield block having a core area and an edge area.
Identical parts are provided with the same reference numerals in all the figures.
DETAILED DESCRIPTION OF THE INVENTION
The gas turbine 1 according to FIG. 1 has a compressor 2 for combustion air, a combustion chamber 4 , and a turbine 6 for driving the compressor 2 and a generator (not shown), or a production machine. The turbine 6 and the compressor 2 are for this purpose located on a common turbine shaft 8 , referred to also as a rotor disk, to which the generator or, as the case may be, production machine is also linked and which is mounted to be rotatable around its central axis 9 . The combustion chamber 4 embodied in the manner of an annular combustion chamber is fitted with a number of burners 10 for burning a liquid or gaseous fuel.
The turbine 6 has a number of rotor blades 12 linked to the turbine shaft 8 . The rotor blades 12 are arranged in a ring around the turbine shaft 8 , thereby forming a number of rotor blade rows. The turbine 6 further includes a number of fixed guide vanes 14 attached, likewise in a ring, to the inner housing 16 of the turbine 6 and forming guide vane rows. The rotor blades 12 therein serve to drive the turbine shaft 8 by means of the transfer of pulses from the hot medium—the working medium M—flowing through the turbine 6 . The guide vanes 14 serve, conversely, to duct the flow of the working medium M between in each case two sequential rotor blade rows or rotor blade rings viewed in the flow direction of the working medium M. A sequential pair comprising a ring of guide vanes 14 or guide vane row and a ring of rotor blades 12 or rotor blade row is therein referred to also as a turbine stage.
Each guide vane 14 also has a platform 18 , referred to also as a vane root, which is arranged on the inner housing 16 of the turbine 6 as a wall element for securing the respective guide vane 14 . The platform 18 is therein a thermally comparatively highly stressed structural component forming the outer limit of a hot gas duct for the working medium M flowing through the turbine 6 . Each rotor blade 12 is analogously secured to the turbine shaft 8 via a platform 20 referred to also as a blade root.
A guide ring 21 is in each case arranged between the platforms 18 , arranged spaced apart, of the guide vanes 14 of two adjacent guide vane rows. The outer surface of each guide ring 21 is therein likewise exposed to the hot working medium M flowing through the turbine 6 and spaced in a radial direction from the outer end 22 of the rotor blade 12 situated opposite it by means of a gap. The guide rings 21 arranged between adjacent guide vane rows serve therein in particular as covering elements that protect the inner wall 16 or other housing mounting parts from excessive thermal stressing by the hot working medium M flowing through the turbine 6 . The combustion chamber 4 is limited by a combustion chamber housing 29 , with a combustion chamber wall 24 being formed on the combustion chamber side. In an exemplary embodiment the combustion chamber 4 is embodied as what is termed an annular combustion chamber in which a plurality of burners arranged peripherally around the turbine shaft 8 discharge into a common combustion chamber space. The combustion chamber 4 is for this purpose embodied in its totality as a ring-shaped structure positioned around the turbine shaft 8 .
The combustion chamber 4 is designed for a comparatively high temperature of the working medium M of approximately 1,200° C. to 1,500° C. in order to achieve a comparatively high level of efficiency. To enable comparatively long operating times even given these operating parameters that are unfavorable for the materials, the combustion chamber wall 24 is provided on its side facing the working medium M with a combustion chamber lining formed from heat shield blocks 26 . To ensure that the structure of the combustion chamber 4 embodied as an annular combustion chamber will be stable in the presence of hot gas, the combustion chamber lining is provided with a plurality of heat shield blocks 26 having high-temperature stability so that a full-coverage, extensively leak-free combustion chamber lining is formed in the annulus in this way.
FIG. 2 is a perspective view of a heat shield block 26 as embodied in particular for lining a combustion chamber wall 24 according to the invention. The combustion chamber block 26 has a cuboidal or cube-like geometry and extends along a longitudinal axis 43 and a transverse axis 45 running substantially perpendicular to the longitudinal axis 43 . The heat shield block 26 has a hot side 35 that can be impinged upon by the hot medium M and a wall side 33 situated opposite the hot side 35 . A core area 31 having a core material 39 extends from the hot side 35 to the wall side 33 through the interior of the heat shield block 26 . The core area 31 is surrounded by an edge area 37 having an edge material 41 , with the thermal conductivity of the edge material 41 being lower than that of the core material 39 . The edge area 37 encloses the core area 31 throughout its circumference along the edges of the cuboidal or cube-like heat shield element 26 . The transition from the core material 39 in the core area 31 to the edge material 41 in the edge area 37 takes place materially cohesively. The thermal conductivity of the edge material 41 is less than 50% that of the core material 39 . This ensures that a temperature profile that is approximately balanced parallel to the hot side 35 will arise in the core area when the heat shield block 26 is used in a combustion chamber 4 of a gas turbine 1 (see FIG. 1 ). The core area 31 will remain substantially free of thermal stress as a result of the thermal insulation effect of the edge area 37 having the reduced thermal conductivity. Temperature gradients and thermal stresses associated therewith will consequently occur only in the edge area 37 or almost exclusively there, which is to say near the edges of the heat shield block 26 . The length of any cracks occurring owing to thermal stresses will hence be shortened and limited to the edge area 31 , and the heat shield block 26 will be stabilized overall in terms of the formation and spreading of cracks compared to conventional embodiments.
FIG. 3 is a sectional view along the intersection III-III of the heat shield block 26 shown in FIG. 2 . Shown therein is a view of the heat shield block 26 in the direction of the transverse axis 45 onto the cutting plane. The core area 31 is cuboidal or cube-like. The edge area 37 surrounds the core area 31 throughout its circumference, with the edge area 31 extending from the hot side 35 to the wall side 33 . The edge area 37 consists of an edge material 41 , with the peripheral lateral face 49 having the edge material 41 . The peripheral lateral face 49 is therein the outermost limiting area of the peripheral side 47 , which abuts the hot side 35 and the wall side 33 . In order to set a reduced thermal conductivity in the edge area 41 compared to the core area 31 , the edge material 41 is embodied as porous material having a plurality of pores, with the porosity of the edge material 41 being selectively set in such a way that the thermal conductivity of the edge material 41 is thereby reduced compared to that of the core material 39 to a desired level. The thermal conductivity of the edge material 41 is, for example, less than 60%, in particular less than 50%, of that of the core material 39 . The core material 39 and the edge material 41 can herein be formed, for example, from the same ceramic base material, in particular a fireproof ceramic material. A particularly firm material bond having a long service life is realized through said material identicality of the base material for the core material 39 and the edge material 41 .
A desired porosity for reducing the thermal conductivity in the edge area 37 is set by, for example, admixing suitable pore-forming materials with the ceramic compound, with the pore-forming materials being pressed or poured into the area of the block being produced that is near the edge and defined by the edge area 37 . The pore-forming material evaporates during sintering, leaving behind pores having a pre-determined pore diameter distribution and pore density distribution within the edge area 37 . The heat shield block 26 will hence be provided in its edge area 37 with lower thermal conductivity differing from that of the core material 39 , for example with a lowering of the thermal conductivity to less than 50% of that of the core material 39 . Along the hot side 35 the axial extent d R of the edge area 37 is therein less than 20%, in particular between around 5% and 10%, of the total axial extent L of the heat shield block 26 . The axial extent d K of the core area 31 having the core material 39 is in this embodiment consequently significantly greater than the axial extent d R of the edge area 37 . The advantages of the core material 39 in the core area 31 in terms of resistance to high-temperature stressing and the impinging thereon of a hot medium M, for example a hot gas, will hence be substantially retained, with the formation of cracks in particular on the hot side 35 in the core area 31 being substantially suppressed, thanks to the thermal insulation effect of the porous edge material 41 , even in conditions of high-temperature or thermal shock stressing. Cracks can, at most, form or spread in the edge area 37 , where this can be tolerated.
FIGS. 4 to 7 show further embodiments of the heat shield block 26 having a modified geometry of the heat shield block 26 (see FIGS. 6 and 7 ) or, as the case may be, having a variation of the geometry of the core area 31 and edge area 37 . FIG. 4 is a sectional view of a heat shield block 26 having an edge area 37 extending from the hot side 35 to the wall side 33 , with the cross-section of the edge area 37 narrowing toward the wall side 33 . The cross-section of the core area 31 correspondingly continuously broadens from the hot side 35 toward the cold side 33 . In contrast to this, FIG. 5 shows an exemplary embodiment of the heat shield block 26 in which the edge area 37 having the edge material 41 forms a partial area of the peripheral lateral face 49 . The edge area 37 faces the hot side 35 and is at the same time a constituent part of the hot side 35 . The peripheral lateral face 49 has both the core material 39 and the edge material 41 , with the edge material 41 facing the hot side 35 and the core material 39 facing the wall side 33 . Depending on the stress to which the heat shield block 26 is exposed and is typical of a particular application, both the geometry of the edge area 37 and core area 31 and the local thermal-conducting properties in the edge area 37 can be modified and adjusted by setting an appropriate porosity of the edge material 41 in the edge area 37 .
FIGS. 6 and 7 show different geometries of the heat shield block 26 in a plan view onto the hot side 35 . The geometry of the core area 31 is in both exemplary embodiments substantially cylindrical and extends from the hot side 35 to the cold side 33 . The outer boundary of the heat shield element 26 exhibits square geometry in FIG. 6 and hexagonal geometry in FIG. 7 . The edge area 37 is substantially a complementary volume to the cylindrical core area 31 . For thermal insulation purposes the edge material 41 has a porosity so that a thermal conductivity significantly reduced compared to that of the core area 31 is achieved in the edge area 37 . The core material 39 and the edge material 41 consist of identical base material or substantially similar base material so that the transition from the core area 31 to the edge area 37 is achieved in the form of a materially cohesive, extensively homogenous material bond which, although chemically identical or similar, will nonetheless cause the desired reduction in thermal conductivity from the core area 31 to the edge area 37 owing to the physical effect of the selectively set porosity of the edge material 41 .
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The invention relates to a heat shield block, particularly for lining a combustion chamber wall, with a hot side that can be subjected to the action of hot medium and with a wall side situated opposite the hot side. A core area, which has a core material, extends inside the heat shield block from the hot side to the wall side. The core area is surrounded by an edge area with an edge material whose heat conductivity is lower than that of the core material. This targeted thermal insulation in the edge area provided in the form of a material bond between the core material and the edge material renders the heat shield block particularly unsusceptible to the formation and growth of cracks in the core area on the hot side. The invention also relates to a combustion chamber provided with heat shield blocks of the aforementioned type, and to a gas turbine provided with a combustion chamber comprising such a heat shield block.
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This application for a United States Patent claims the benefit of the filing date of United States Provisional Application for Patent having Ser. No. 60/061,042 filed on Sep. 26, 1997 as this application is a continuation of U.S. patent application Ser. No. 09/677,164 filed on Oct. 2, 2000 and having issued as U.S. Pat. No. 6,813,995 on Nov. 9, 2004, which is a continuation-in-part of U.S. patent application Ser. No. 09/329,690 filed on Jun. 10, 1999 and having issued as U.S. Pat. No. 6,143,341 on Nov. 7, 2000, which is a divisional of U.S. patent application Ser. No. 09/083,416 filed on May 22, 1998 and having issued as U.S. Pat. No. 6,038,964 on Mar. 21, 2000, which claims the benefit of U.S. Provisional Application for patent Ser. No. 60/061,042 filed on Sep. 26, 1997.
TECHNICAL FIELD
The present invention relates to convection based ovens, grills and similar cooking apparatus and, more specifically, to a convection based cooking apparatus with an internal draft chimney.
BACKGROUND OF THE INVENTION
Convection based cooking apparatus operate on the principle that hot air rises. A heating element generates hot air within a cabinet of the cooking device. The hot air generated by the heating element is drawn over a cooking surface inside the cabinet. Typically, an elongated draft chimney is used as a draft generator to pull air through the cabinet interior. Known draft chimneys are attached to the exterior of a side wall of the cabinet. The heated air that is forced into the chimney rises to the top of the chimney and exits through an opening at the top of the chimney. As the heated air rises through the chimney, a vacuum, similar to a siphon, is generated to draw additional air through the interior of the cabinet. This allows items on the cooking surface to be cooked more quickly. Alternatively, decreasing the rate of airflow through the chimney allows items on the cooking surface to be cooked at a slower rate.
However, these known draft chimneys attached to the exterior of the cabinet are large and cumbersome. The length of the chimney typically extends approximately two feet above the cabinet. Also, because the chimneys are attached to the exterior side wall of the cabinet, the width of the entire apparatus is increased by at least the width of the chimney.
Therefore, there is a need in the art for a compact convection based apparatus that does not include a massive, exterior mounted, chimney, but continues to facilitate airflow as described above.
SUMMARY OF THE INVENTION
The present invention solves the above-identified problem by providing an improved draft chimney for convention based cooking apparatus. The improved draft chimney of the present invention is substantially contained within the confines of the cabinet of the cooking apparatus.
Generally described, the draft chimney of the present invention includes a flue. The flue at least partially defines a path of convection airflow through at least a portion of the interior of a cabinet of the cooking apparatus. The flue passes convection airflow to the exterior of the cabinet.
In one aspect of the present invention, the draft chimney is entirely defined within the cabinet and the path of convection airflow communicates with the exterior of the cabinet at an end of the path.
More particularly described, the flue includes opposing first and second openings. The first opening communicates with the cabinet interior and is at least partially defined by at least a portion of a surface of the cabinet interior. Preferably, the first opening is at least partially defined by either a portion of a bottom surface of the cabinet or by the entire width of the bottom surface of the cabinet.
The foregoing has broadly outlined some of the more pertinent aspects and features of the present invention. These should be construed to be merely illustrative of some of the more prominent features and applications of the invention. Other beneficial results can be obtained by applying the disclosed information in a different manner or by modifying the disclosed embodiments. Accordingly, other aspects and a more comprehensive understanding of the invention may be obtained by referring to the detailed description of the exemplary embodiments taken in conjunction with the accompanying drawings, in addition to the scope of the invention defined by the claims.
BRIEF DESCRIPTION OF THE DRAWINGS
FIG. 1 illustrates a perspective view of one embodiment of the improved draft chimney of the present invention within a convection based grill.
FIG. 2 illustrates a perspective view of an alternative embodiment of the improved draft chimney of the present invention within a convection based grill.
FIGS. 3A and 3B illustrate a side view of the convection based grill of either of FIGS. 1 and 2 .
FIG. 4 illustrates a top view of the convection based grill of either of FIGS. 1 and 2 .
FIG. 5 illustrates a perspective view of one embodiment of a hood of a convection based grill showing, in particular, a plurality of exit openings for venting airflow from the cabinet through the chimney of the present invention.
DETAILED DESCRIPTION
Referring now to the drawings in which like numerals indicate like elements throughout the several views, FIGS. 1 and 2 each depict one embodiment of an improved draft chimney 10 of the present invention within a convection based grill 12 . Each convection based grill 12 includes a cabinet 14 with a plurality of surfaces for defining a cabinet interior 16 ( FIGS. 3A and 3B ). The cabinet interior 16 is divided into two chambers by an insulating baffle 18 extending across the longitudinal dimension of the cabinet 14 . The two chambers include a heating chamber 20 and a cooking chamber 22 .
In the lower portion of the heating chamber 20 is a heating element 24 and a steel flame grate 26 is positioned over the heating element 24 . A cooking surface 28 substantially extends the length and the width of the cooking chamber 22 . The grill 12 is described in greater detail in copending U.S. patent application having U.S. Ser. No. 09/083,416 filed on May 22, 1998 and titled “A CONVECTION BASED COOKING APPARATUS WITH IMPROVED AIRFLOW”, and in copending U.S. patent application having U.S. Ser. No. 09/329,690 filed on Jun. 10, 1999 and titled “A CONVECTION BASED COOKING APPARATUS WITH IMPROVED AIRFLOW”, the entire disclosures of which are incorporated herein by reference.
Referring now to FIGS. 3A , 3 B and 4 , the cabinet 14 is defined by a bottom surface 30 , a front surface 32 , a back surface 34 , a left side surface 36 , and a right side surface 38 . The combination of the bottom surface 30 with lower portions of the front surface 32 , the back surface 34 , the left side surface 36 and the right side surface 38 , defines a lower portion of the cabinet interior, and is commonly referred to as a lower container 40 . Also, the cabinet 14 is further defined by a hood 42 , the interior of which is commonly referred to as an upper cabinet interior, best illustrated in FIG. 5 . The hood 42 is defined by upper portions of the front surface 32 , the back surface 34 , the left side surface 36 , and the right side surface 38 .
Still referring to FIGS. 3A and 3B , the chimney 10 is defined by the right side surface 38 , portions of the front and back side surfaces 32 , 34 , and an internal surface 50 positioned in substantially a vertical manner. In FIG. 3A , the internal surface 50 is parallel to the right side surface 38 . In another embodiment, as shown in FIG. 3B , a portion of the internal surface 50 is parallel to the right side surface 38 and an another portion of the internal surface 50 tapers away from the right side surface 38 .
As best shown in FIGS. 1 and 2 , the internal surface 50 has an upper portion 52 and a lower portion 54 . The upper portion 52 is attached to the inside of the hood 42 and the lower portion 54 is attached to the inside of the lower container 40 . When the hood 42 is opened to expose the cabinet interior 16 as shown in FIGS. 1 and 2 , the draft chimney 10 is separated into two pieces. However, when the hood 42 is closed as shown in FIGS. 3A and 3B , the upper and lower portions 52 , 54 are joined together to define the entire length of the draft chimney 10 . The length of the draft chimney is commonly refer to as a flue and is described in greater detail below.
In order to insure the upper and lower portions 52 , 54 of the internal surface 50 are properly joined together each time they come into contact with each other, the ends of each portion are bent back in a widthwise manner to define flanges 56 and 58 . The end of the upper portion 52 of the internal surface is bent inward and the end of the lower portion 54 of the internal surface in bent outward toward the right side surface 38 to form a seal when the hood 42 is closed. FIG. 4 also illustrates the inwardly bent flanges 56 , 58 of the internal surface 50 . The seal is formed by permitting the upper and lower portions 52 , 54 to overlap as shown in FIG. 3A . Alternatively, as shown in FIG. 3B , the seal could be formed by permitting the flange 56 to directly abut the flange 58 without the upper and lower portions 52 , 54 overlapping.
The draft chimney 10 includes an elongated, vertical flue 60 having a first opening 62 and a second opening 64 . The internal surface 50 defines a portion of the flue 60 . Therefore, the flue 60 is separable into two portions as shown in FIGS. 1 and 2 . Preferably, the flue 60 is prismatic and the length of the flue 60 in the direction of airflow is longer than the width of the flue; however, alternative configurations are also anticipated by the present invention. The first opening 62 communicates with the cabinet interior 16 . Preferably, the first opening 62 is defined between the bottom surface 30 and the end of the vertically positioned internal surface 50 as shown in FIGS. 1 and 2 . The width of the first opening 62 can extend only a portion of the width of the cabinet 14 as shown in FIG. 1 or, alternatively, the width of the first opening 62 can extend the full width of the cabinet 14 as shown in FIG. 2 .
In operation, ambient air enters the heating chamber 20 through an air inlet 70 . The ambient air is heated and rises through the steel frame grate 26 towards the top of the heating chamber 20 . Eventually, the heated air is forced through an air passage 72 over the baffle 18 into the cooking chamber 22 . As the heated air is forced into the cooking chamber 22 , the cooler air existing the cooking chamber 22 is forced down through the first opening 62 of the flue 60 . The heated air that is forced into the flue 60 of the draft chimney 10 rises to the top and exits through the second opening 64 in the top of the hood 42 to the environment surrounding the cabinet 14 . In the preferred embodiment, a plurality of smaller exit openings combined together to form the second opening 64 as shown in FIG. 5 . The portion of the surface with the smaller exit openings is commonly referred to as being grilled.
A path of convection airflow, generally shown by arrows 80 a , 80 b and 80 c in FIGS. 3A and 3B is created within the cabinet 14 during operation of the grill 12 . The portion 80 a of the path begins at the air inlet 70 and proceeds to the passage 72 over the baffle 18 as described above. Then, the path continues through the cooking chamber 22 to pass over the cooking surface 28 in an even manner. This portion of the path is shown by the reference numeral 80 b. Next, the path continues to the first opening 62 of the flue 60 of the draft chimney 10 . The portion 80 c begins at the first opening 62 , rises to the second opening 64 , and passes into the exterior environment surrounding the grill 12 . Preferably, the draft chimney 10 is entirely defined within the cabinet 14 such that the end of the path 70 communicates with the exterior of the cabinet as best shown in FIGS. 1-3A and 3 B. Alternatively, the flue 60 may extend beyond the top of the hood 42 so that a portion of the path of airflow extends beyond the cabinet 16 before exiting to the environment surrounding the grill.
The present invention has been illustrated in relation to particular embodiments which are intended in all respects to be illustrative rather than restrictive. Those skilled in the art will recognize that the present invention is capable of many modifications and variations without departing from the scope of the invention. Accordingly, the scope of the present invention is described by the claims appended hereto and supported by the foregoing.
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A draft chimney for a convention based apparatus. The draft chimney comprises a flue at least partially defining a path of convection airflow through at least a portion of the interior of a cabinet. The flue passes convection airflow to the exterior of the cabinet.
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FIELD OF THE INVENTION
The invention relates to improved techniques for producing and purifying vitamin D 3 receptor proteins through the use of recombinant DNA sequences.
BACKGROUND OF THE INVENTION
1,25-dihydroxyvitamin D 3 ("1,25-(OH) 2 D 3 "), the hormonal form of vitamin D, has several important biological activities in mammals. These activities include: (i) stimulation of intestinal calcium and phosphate transport from the lumen of the small intestine to the plasma; (ii) mobilization of calcium from bone to plasma; and (iii) reabsorption of calcium in the distal renal tubule. The biological activities of vitamin D ultimately lead to the elevation of plasma calcium and phosphorus levels which are necessary for bone mineralization and proper neuromuscular function.
The biological activities of 1,25-(OH) 2 D 3 are mediated via intracellular receptor protein. DeLuca, H.F. et al., (1983) Ann. Rev. Biochem. 52, 411-439. (The disclosures of all articles recited herein are incorporated by reference as if fully set forth below.) The probable mechanism by which 1,25-(OH) 2 D 3 elicits the intestinal calcium and phosphorus transport response consists of the 1,25-(OH) 2 D 3 hormone entering the target cell and binding the nuclear receptor. The interaction of hormone with receptor may introduce changes in receptor conformation that allow the receptor to interact with chromatin. This interaction alters the expression of genes whose protein products influence functions such as calcium transport and mobilization. Link, R. et al. (1985) in The Vitamin D Receptor, Academic Press, New York, pp. 1-35.
Vitamin D-dependent rickets Type II is a disease that exemplifies the receptor-dependent function of 1,25-(OH) 2 D 3 . Bell, N.H. et al. (1978) N. Engl. J. Med. 298, 996-999. Patients with this disease suffer from hypocalcemia despite having elevated levels of 1,25-(OH) 2 D 3 in their plasma because they have a target organ resistance to the hormonal derivative of vitamin D. A defect in the 1,25-(OH) 2 D 3 receptor exists in at least one subgroup of rickets Type II patients. Eil, C., et al. (1986) Adv. Exp. Med. Biol. 196, 407-422.
The sequences for various animal vitamin D receptors are known. See McDonnell, D.P. et al., (1987) Science 235, 1214-1217 (Avian) (SEQID NO:3) Burmester, J.K., et al. (1988) Proc. Natl. Acad. Sci. USA 85, 1005-1009 (rat) (SEQ ID NO:4), and Baker, A.R. et al., (1988) Proc. Natl. Acad. Sci. USA 85, 3294-3298 (human)(SEQID NO:5). The amino acid sequences for these cDNAs have much in common. For example, the cDNAs display a cysteine-rich region at the amino terminus, characteristic of a DNA binding region. Also, the hydrophobic amino acids near the carboxy terminus form what is likely the hydrophobic pocket responsible for hormone binding. Domains within the human 1,25-(OH) 2 D 3 receptor protein have been defined more precisely in McDonnell, D.P. et al., (1989) Mol. Endocrinol. 3, 635-644.
Discovery of cis-acting vitamin D-response elements (DRE) lying within the upstream regions of the human (Kerner, S.A., et al. (1989) Proc. Natl. Acad. Sci. USA 86, 4455-4459) and rat (Demay, M.B., et al. (1990) Proc. Natl. Acad. Sci. USA 87, 369-373, Markose, E.R. et al., (1990) Proc. Natl. Acad. Sci. USA 87, 1701-1705) osteocalcin genes, and the mouse osteopontin gene (Noda, M. et al., (1990) Proc. Natl. Acad. Sci. USA 87, 9995-9999) is consistent with 1,25-(OH) 2 D 3 being a member of the steroid family of receptors. The sequences of other receptor DNA can now readily be determined using the existing sequences as hybridization probes against genomic and CDNA libraries, obtaining the cDNA using standard screening techniques, and then sequencing the DNA.
Lack of a low cost source of large amounts of 1,25-(OH) 2 D 3 receptor has hindered commercial use and scientific studies of the receptor. For example, as disclosed in U.S. Pat. No. 4,816,417, 1,25-(OH) 2 D 3 receptor is useful in an assay for 1,25-(OH) 2 D 3 .
Isolation-of receptor from natural animal cells produces only very small quantities at very great cost. Dame, M. et al., (1986) Biochemistry, 25, 4523. The human 1,25-(OH) 2 D 3 receptor has been expressed from full length DNA in Saccharomyces cerevisiae (yeast) cells. Sone, T., et al., (1990) J. Biol. Chem. 265, 21997-22003. However, the authors indicated potential problems in that the recombinant product upon purification lacked activities comparable to the natural receptor protein and amounts of receptor protein produced were quite low.
The need therefore exists for the creation of an improved method for expressing vitamin D receptor protein.
SUMMARY OF THE INVENTION
In one aspect, the present invention provides a method of producing 1,25-dihydroxyvitamin D 3 receptor protein. This method begins with the step of transcribing a DNA sequence to form an RNA sequence, the RNA sequence encoding animal vitamin D receptor. The receptor protein is then expressed from the RNA sequence. Less than the full natural 5' non-translated leader sequence is transcribed as part of the RNA sequence.
In a particularly advantageous embodiment, a 5' non-translated leader sequence on the RNA is less than 60% and more than 2% of the full natural 5' non-translated leader sequence. In another preferred embodiment, less than 90% of the full natural 3' non-translated flanking sequence is transcribed as part of the RNA.
In another aspect, the invention provides 1,25-dihydroxyvitamin D 3 receptor protein using the above methods.
In still another aspect, the invention provides an expression system for the production of 1,25-dihydroxyvitamin D 3 receptor protein. The system has an insect cell host and a recombinant virus. The virus contains a foreign DNA sequence encoding an RNA sequence which, when expressed in the insect cell host, produces 1,25-dihydroxyvitamin D receptor protein.
In yet another related aspect, the invention also provides a recombinant plasmid containing a DNA sequence encoding 1,25-dihydroxyvitamin D 3 receptor protein, the DNA sequence containing a 5' non-translated sequence that when transcribed to RNA produces an RNA sequence that has less than the full 5' leader sequence present in the natural form of the RNA sequence.
An object of the present invention is to produce 1,25-(OH) 2 D 3 receptor protein at low cost and in high quantity.
Another object is to produce the receptor protein in a biologically active state.
Another object of the invention is to express receptor protein that is at least 5% of the total soluble protein extracted from host expressing cells.
BRIEF DESCRIPTION OF THE DRAWINGS
FIG. 1 depicts rat 1,25-(OH) 2 D 3 receptor CDNA. The arrows labeled I and II denote the location of the sequences from which the synthetic oligonucleotide primers were derived. The position of a unique Nae I restriction site is also indicated;
FIG. 2 describes the nucleotide sequence of primers that were used in the PCR amplification of the 1,25-(OH) 2 D 3 receptor open reading frame (ORF). Artificial BamH I recognition sequences are highlighted. Random tailing sequences are shown in lower case letters; and
FIG. 3 is a schematic representation of recombinant plasmid PCR-YM1, which consists of the segment of receptor CDNA inserted to plasmid vector pAcYM1.
DESCRIPTION OF THE PREFERRED EMBODIMENTS
The description of the preferred embodiments below are examples of the invention. They are not, however, intended to represent the full scope of the invention. The claims should be examined to determine the full scope of the invention.
1. Overview
As an example, we chose to express modified rat receptor DNA in a baculovirus expression system. Receptor DNA sequences from other animals that have been modified in accordance with the present invention are equally suitable for the practice of the present invention.
Baculovirus vector/insect cell expression systems have been used to express certain other CDNAS. See Luckow, V.A., (1990) in Recombinant DNA Technology And Applications, McGraw-Hill, N.Y. pp. 1-25; Summers, M. & Smith, G.E. (1987) A Manual of Methods for Baculovirus Vectors and Insect Cell Culture Procedures, Texas Agricultural Experiment Station and Texas A & X University, College Station, Tex.; and Summers, M.D. (1989) in Concepts in Viral Pathogenesis, N.Y. pp. 77-86. However, there are no previous reports of such systems being successfully used to express vitamin D 3 receptor protein, and our attempts to express natural vitamin D 3 receptor DNA in such baculovirus systems were not successful.
We then created a plasmid containing modified receptor cDNA. A problem we faced in making modifications was that the sequence of the CDNA indicated that there were no convenient restriction sites where we wanted to modify. We therefore used a special adaptation of polymerase chain reaction to construct a version of the receptor CDNA with truncated 5' and 3' untranslated flanking sequences and cloned this truncated CDNA segment into a plasmid vector. We then co-transfected this plasmid with DNA from ACNDV, a wild-type baculovirus, into Sf21 insect cells. Co-transfection produced a recombinant baculovirus containing the receptor segment. The recombinant virus was identified by a unique visual screening technique for plaque morphology and purified through three rounds of plaque purification.
2. Construction Of Recombinant Plasmid Transfer Vector PCR-YM1
Plasmid pRDR26 is a pUC18 derivative harboring a 2043 base pair (bp) rat 1,25-(OH) 2 D 3 receptor CDNA. The 2043 bp segment is illustrated in FIG. 1. This CDNA is believed to contain complete 5' and 3' untranslated regions and the receptor protein-encoding region. The construction of this plasmid, together with the nucleotide sequence of the rat CDNA (SEQID NO:6), has been described Bummester, J.K. et al., (1988) Proc. Natl. Acad. Sci. USA 85, 9499-9502.
Our belief is that the non-translated sequences of the receptor DNA needs some length for message stability, but that too much length destroys expression. The rat receptor 5' nontranslated leader sequence is 94 bp (FIG. 1.). We decided to shorten it to 45 bp and to add a BAMH I site to permit cloning. We also decided to shorten the 3' nontranslated sequence to 300 bp.
Unfortunately, as indicated above, these non-translated regions lacked convenient restriction enzyme recognition sites. We chose to create a "truncated" modified CDNA by amplifying only a defined segment of the known CDNA using a modification of polymerase chain reaction techniques. This approach circumvented the restriction site problem.
For this purpose oligonucleotide primers were synthesized as follows: Primer I contained nucleotides -45 to -23, and Primer II contained nucleotides 1569 to 1547. FIG. 2 describes these primers. Primer I is SEQ ID WO:1 and Primer II is SEQ ID NO:2 in the Sequence Listing below. Both primers were synthesized with both the recognition sequence for BamH I and 8 nucleotides of random sequence at their 5' termini.
To perform the PCR-mediated truncation, we first transformed E. coli strain DH5α (Manahan, D. (1983) J. Mol. Biol. 166, 557-580) with pRDR26, and a single colony was transferred into 150 μl H 2 O to make a homogeneous cell suspension. Fifteen μl of the cell suspension were added to the following PCR reaction components: 1 μM primer I, 1 μM primer II, 1x Taq polymerase reaction buffer, 2 units Taq polymerase (Promega Corp., Madison, Wis.), and 200 nM deoxynucleotide triphosphates (DATP, DGTP, DCTP, and dTTP) in a total reaction volume of 100 pl. A Perkin Elmer Cetus, DNA Thermal Cycler was used to change the reaction temperature. We used the following time and temperature parameters: 94° C. for 1 min., 20 cycles [94° C. for 1 min., 55° C. for 1 min., 72° C. for 1.5 min.], 72° C. for 5 min., storage at 4° C.
An aliquot of the amplified DNA was treated with BamH I to generate the appropriate cohesive restriction termini and then ligated with 1 μg of BamH I-digested plasmid transfer vector pAcYM1 (Matsuura, Y. et al., (1987 ), J. Gen. Virol. 68, 1233-1250) in the presence of T4 DNA ligase for 18 hours at 16° C. Vector pAcYM1 contains polyhedron sequences that permit recombination with a wild-type baculovirus. Vector pAcYM1 is available from Dr. D.H.L. Bishop (NERC Institute of Virology, Oxford, U.K.).
A portion of the ligated mixture was used to transform competent cells of strain DH5α to ampicillin resistance (Ap R ) (Hanahan, D. (1985) in DNA Cloning: A Practical Approach, IRL Press, Oxford, p. 109). Small-scale isolation and restriction analysis of plasmid DNAs from several Ap R transformants revealed four having the proper PCR-amplified product contained within the pAcYN1 vector. We identified a recombinant plasmid with the insert DNA in the proper orientation with respect to the polyhedrin gene signals from pAcYM1 by using several different combinations of restriction endonuclease digestions, and subsequent analysis by agarose gel electrophoresis. The recombinant plasmid transfer vector was designated PCR-Ym1. FIG. 3 illustrates PCR-YM1. For other CDNA (e.g. avian, human, pig) trancation/modifications can be achieved in similar fashion.
3. Generation Of Recombinant Baculovirus DR-AcNPV
AcNPV is a wild-type baculovirus. It is commercially available from InVitroGen Corp. (San Diego, Calif.). Upon co-transfection of an insect host with a plasmid containing a foreign gene flanked by polyhedron sequences, a recombinant baculovirus will be formed. The co-transfections and protein expression can be done in various insect cells, such as Sf21 cells. Sf21 cells are insect cells commonly used for the baculovirus expression system and are also commercially available from InVitroGen Corp. (San Diego, Calif.).
We performed the co-transfection as follows: Fifteen μg PCR-YM1 plasmid DNA, purified by ethidium bromide-CsCl equilibrium density gradient centrifugation, was added to 1 μg wild-type ACNPV DNA (Granados, R.R.-et al., (1986) in Biological Properties and Molecular Biology, CRC, Boca Raton, Fla., vol. 1, pp. 90-127) and transfected into SF21 cells (Vaugh, J.L. et al., (1977) In Vitro 13, 213-217) using the Lipofectin (Gibco BRL/Life Technologies, Inc, Gaithersburg, Md.) reagent according to the manufacturer's specifications. The Sf21 (Spodoptera frugiperda) insect cells and wild-type ACNPV (Autographs californica nuclear polyhedrosis virus) that we used were gifts from Dr. Paul Friesen (Dept. of Biochemistry, University of Wisconsin, Madison, Wis.).
After a 96-hour incubation of the co-transfection mixture at 27° C., the viral supernatant was harvested as in Summers et al. (above). This supernatant contained both recombinant and non-recombinant virion particles. Dilutions of this viral preparation were used to infect freshly plated Sf21 cells according to the agarose overlay procedure (Summers et al., above). Plaques derived from a potential occlusion deficient, recombinant virus were picked and purified through three rounds of purification. We confirmed that we had created recombinant virus DR-AcNpv, containing the 1,25-(OH) 2 D 3 receptor coding region, by hybridization screening (Summers et al., above).
We have deposited DR-ACNPV with American Type Culture Collection 12301 Parklawn Drive, Rockville, Md., U.S.A., as ATCC No. VR2334, on Jul. 26, 1991. Samples from the deposit are available in accordance with U.S. patent law requirements upon issuance of the patent and the requirements of any applicable foreign patent laws. No patent license is intended by such availability.
4. Preparation Of Protein Extracts From Infected Insect Cells
Sf21 cells were plated at a density of 3×10 6 per 100 nm plate in TC100 (Gibco BRL) insect cell media and allowed to attach for 30 to 60 min. The medium was removed and 1 ml of either DR-ACNPV or ACNPV (multiplicity of infection=1 to 10) was added to the surface of the cell monolayer. (AcNPV, the wild-type virus, was added as a control.) The cells were maintained at 27° C. with gentle rocking for 60 min. This was followed by the addition of 5 ml of TC100 media supplemented with 10% fetal calf serum and continued incubation at 27° C. Cells were harvested 72 hr after infection with virus unless otherwise noted.
Extracts of soluble protein were prepared by first disrupting the infected cells by repeated pipetting and washing of the plate surface. The suspended cells were transferred to a plastic conical tube and collected by centrifugation at 500 x g for 10 min. The medium was discarded and the cells were suspended in TEDK 20 [50 mM Tris-HCl, pH 7.4/1.5 mM EDTA/5 mM dithiothreitol/20 mM KCl] containing 1 mM phenylmethylsulfonyl fluoride (PMSF), 5 mM diisopropylfluorophosphate (DFP), and 1 μg/ml pepstatin. The cell suspension was incubated for 30 min on ice before homogenization in a stainless steel Dounce homogenizer (3 strokes). Enough TED buffer, containing 600 mM KCl, was added to bring the final KCl concentration to 300 mM. The cells were homogenized with 3 additional strokes and the homogenate was centrifuged for 60 min at 45,000 rpm in a Beckman 70.1 Ti rotor. The cleared supernatant was divided into small aliquots and quick-frozen in liquid nitrogen. Storage of the extracts was at -70° C.
5. Gel Electrophoresis Analysis Of Protein Extracts
We analyzed both total cell protein and soluble cell protein via gel electrophoresis. The soluble cell protein is that obtained by the method described above. Total cellular protein extracts were prepared by infecting and harvesting the cells as described above. The cells, collected by centrifugation, were lysed in 4% SDS, electrophoresis sample buffer. Vialard, J. et al., (1990) J. Virol. 64, 37-50. Total protein extracts or total soluble protein extracts were mixed with electrophoresis buffer (Laemmli U.K. (1970) Nature 227, 680-685) and boiled for 1 min. The protein samples were electrophoresed on 9% SDS-polyacrylamide gels.
Confirmation of rat 1,25-(OH) 2 D 3 receptor protein production in infected insect cells was obtained by SDS-polyacrylamide gel analysis of cell extracts. We observed that a prominant band at Mr 55,000 evident in the extract from cells infected with DA-ACNPV is not present in the extract from Sf21 cells or the extract from Sf21 cells infected with wild-type AcNPV. We believe that this Mr 55,000 band is due to the receptor protein.
6. Measurement Of 1,25-(OH) 2 D 3 Receptor Via Hydroxylapatite Binding And Immunoradiometric Assay
The 1,25-(OH) 2 -(26,27- 3 H]D 3 binding activity in total soluble protein extracts from DR-AcNPV-infected Sf21 cells was determined by a hydroxylapatite binding assay as previously described in Dame et al., (1985) Proc. Natl. Acad. Sci. USA 82, 7823-7829. Total 1,25-(OH) 2 D 3 receptor was determined by an immunoradiometric assay (IRMA). Sandgren, M. et al., (1989) Anal. Biochem. 183, 57-63. Protein content of the extracts was measured by the Bradford method. Bradford, M.M. (1976) Anal. Biochem. 72, 248-254. 1,25-(OH) 2 D 3 was a gift from the Hoffmann-LaRoche Co. (Nutley, N.J.). 1,25-(OH) 2 -[26,27- 3 H]D 3 (160 Ci/mmol; 1 Ci=37 GBq) was produced by Dupont/NEN (Boston, Mass.) as described. Napoli, J.L. et al., (1980) Biochemistry 19, 2515-2521.
Table 1 (following) describes the results of quantification of recombinant 1,25-(OH) 2 D 3 receptor using the hydroxylapatite ligand-binding assay and the ligand-independent, immunoradiometric assay. The level of receptor per weight of material was determined to be nearly 1500 times greater when derived from our method than from the prior art pig nuclear extract (1.35 pmol/mg).
TABLE 1______________________________________Measurements of 1,25-(OH).sub.2 D.sub.3 Receptor.sup.a Ligand Binding Assay.sup.b IRMA.sup.cSample (pmol/mg protein) (pmol/mg protein)______________________________________Recombinant 2,000 ± 1,000 2,300 ± 1,000DR-AcNPV/Sf21CytosolPig Intestinal 1.35 ± 0.15 1.68 ± 0.12Nuclear Extract______________________________________ .sup.a These levels represent an average of measurements performed in triplicate on six different cytosolic preparations. .sup.b Obtained using the hydroxylapatite assay. .sup.c Obtained using the immunoradiometric assay.
7. Characteristics Of The Recombinant 1,25-(OH) 2 D 3 Receptor
a. Scatchard Analysis
We confirmed that our receptor protein binds to vitamin D with a binding constant similar to that of natural receptor. A 1,25-(OH) 2 D 3 saturation analysis of cytosol from DR-AcNPV-infected Sf 2 l cells was plotted by the method of Scatchard. The equilibrium dissociation constant (Kd), calculated by linear regression, was 1×10 -11 M. The Kd value is consistent with the reported measurements of 10 -10 to 10 -11 M for the hormone-receptor complex in crude preparations. Link, R. et al. (1985) in The Vitamin D Receptor, Academic Press, New York, pp. 1-35.
b. Western Blot Analysis
We then confirmed that our receptor bound to antibody to natural rat receptor, but not to antibody specific for pig receptor. Samples containing both recombinant and non-recombinant 1,25-(OH) 2 D 3 receptor were electrophoresed on polyacrylamide gels. The proteins were immobilized on filters and the filters were blocked with Tris-buffered saline/Tween 20 (TBST) containing 5% nonfat dry milk. The filters were then incubated with primary antibody for 90 min. The filters were washed extensively in TBST and then incubated with a secondary alkaline-phosphatase-conjugated goat anti-mouse IgG antibody. The color was developed with nitrobluetetrazolium/5-bromo-4-chloro-3-indolylphosphate substrate using the ProtoBlot AP system according to manufacturer's specifications (Promega Corp., Madison, Wis.). Monoclonal anti-receptor antibody preparation has been described in Dame, et al., (1986) Biochemistry 25, 4523-4534).
Monoclonal antibody IVG8C11, known to cross-react with 1,25-(OH) 2 D 3 receptor from pig, rat, monkey, human and chicken (Dame, M.C. et al., (1986) Biochemistry 25, 4523-4534), was used in the Western analysis of extract from Sf21 cells. IVG8C11 reacted with our recombinant receptor.
An identical blot was analyzed with the monoclonal antibody XVIE10B6A5 as the primary antibody. This anti-receptor antibody is known to react only with porcine-derived 1,25-(OH) 2 D 3 receptor. Dame, M.C. et al., (1986) Biochemistry 25, 4523-4534. The Western analysis using XVIE10B6A5 showed no reactivity with the extract from DR-AcNPV-infected Sf21 cells.
In summary, the present invention solves the problems in prior art methods of producing 1,25-(OH) 2 D 3 receptor. In our experiments, the present invention produced 2,000 pmol/mg cellular protein of receptor that reacts with activity like the natural protein. This quantity and quality of protein should be compared to the reported 100 pmol/mg cellular protein produced in the yeast system, which upon purification did not have activities comparable to wild type activities, and the 1.35 pmol/mg cellular protein our lab reported producing from the natural pig intestinal nuclear extract system.
8. Other Systems
While rat, human, avian, and porcine receptors are preferred, the method of the present invention should be applicable for expression of receptor protein derived from other animal (e.g. mammalian and avian) systems. A CDNA encoding the receptor will typically first be isolated from the animal cells using known receptor fragments as probes. Once a CDNA sequence is obtained, it will then be sequenced using standard techniques and the sequence must be modified according to the method of the present invention. The 3' and 5' nontranslated flanking sequences should preferably be truncated by between 90% and 2 %. More preferably, the 5' untranslated sequence is shortened to approximately 45 nucleotides and the 3' untranslated sequence is shortened to approximately 300 nucleotides. A plasmid containing this truncated CDNA will then be co-transfected with baculovirus. Co-transfection will produce a recombinant virus. This virus can be used to infect insect cells, and the recombinant protein can be expressed.
__________________________________________________________________________SEQUENCE LISTING(1) GENERAL INFORMATION:(iii) NUMBER OF SEQUENCES: 6(2) INFORMATION FOR SEQ ID NO:1:(i) SEQUENCE CHARACTERISTICS:(A) LENGTH: 37 base pairs(B) TYPE: nucleic acid(C) STRANDEDNESS: single(D) TOPOLOGY: linear(iii) HYPOTHETICAL: YES(iv) ANTI-SENSE: NO(x) PUBLICATION INFORMATION: (A) AUTHORS: Ross, Troy K.Prahl, Jean M.DeLuca, Hector F.(B) TITLE: Overproduction of rat 1,25-dihydroxyvitaminD3 receptor in insect cells using the baculovirusexpression system(C) JOURNAL: Proc. Natl. Acad. Sci. U.S.A.(D) VOLUME: 88(F) PAGES: 6555-6559(G) DATE: August-1991 (K) RELEVANT RESIDUES IN SEQ ID NO:1: FROM 1 TO 37(xi) SEQUENCE DESCRIPTION: SEQ ID NO:1:CGAGCCGGGGATCCTCCAGGAGAGCACCCTTGGGCTC37(2) INFORMATION FOR SEQ ID NO:2:(i) SEQUENCE CHARACTERISTICS:(A) LENGTH: 37 base pairs(B) TYPE: nucleic acid(C) STRANDEDNESS: single (D) TOPOLOGY: linear(iii) HYPOTHETICAL: YES(iv) ANTI-SENSE: NO(x) PUBLICATION INFORMATION:(A) AUTHORS: Ross, Troy KPrahl, Jean MDeLuca, Hector F(B) TITLE: Overproduction of rat 1,25-dihydroxyvitaminD3 receptor in insect cells using the baculovirusexpression system(C) JOURNAL: Proc. Natl. Acad. Sci. U.S.A. (D) VOLUME: 88(F) PAGES: 6555-6559(G) DATE: August-1991(K) RELEVANT RESIDUES IN SEQ ID NO:2: FROM 1 TO 37(xi) SEQUENCE DESCRIPTION: SEQ ID NO:2:CGAGCCGGGGATCCAGTTCCGCCTTCAGCCCCTGCCC37(2) INFORMATION FOR SEQ ID NO:3:(i) SEQUENCE CHARACTERISTICS:(A) LENGTH: 70 amino acids (B) TYPE: amino acid(C) STRANDEDNESS: single(D) TOPOLOGY: linear(ii) MOLECULE TYPE: protein(iii) HYPOTHETICAL: NO(iv) ANTI-SENSE: NO(vi) ORIGINAL SOURCE:(A) ORGANISM: Chicken(x) PUBLICATION INFORMATION:(A) AUTHORS: McDonnell, Donald P.Mangelsdorf, David J.Pike, J. W. Haussler, Mark R.O'Malley, Bert W.(B) TITLE: Molecular Cloning of Complementary DNAEncoding the Avian Receptor for Vitamin D(C) JOURNAL: Science(D) VOLUME: 235(F) PAGES: 1214-1217(G) DATE: March 6-1987(xi) SEQUENCE DESCRIPTION: SEQ ID NO:3:ArgIleCysGlyValCysGly AspArgAlaThrGlyPheHisPheAsn151015AlaMetThrCysGluGlyCysLysGlyPhePheArgArgSerMetLys20 2530ArgLysAlaMetPheThrCysProPheAsnGlyAspCysLysIleThr354045LysAspAsnArgArgHisCysGln AlaCysArgLeuLysArgCysVal505560AspIleGlyMetMetLys6570(2) INFORMATION FOR SEQ ID NO:4:(i) SEQUENCE CHARACTERISTICS:(A) LENGTH: 367 amino acids (B) TYPE: amino acid(C) STRANDEDNESS: single(D) TOPOLOGY: linear(ii) MOLECULE TYPE: protein(iii) HYPOTHETICAL: NO(iv) ANTI-SENSE: NO(vi) ORIGINAL SOURCE:(A) ORGANISM: Rat(x) PUBLICATION INFORMATION:(A) AUTHORS: Burmester, James K.Maeda, NobuyoDeLuca, Hector F.(B) TITLE: Isolation and expression of rat1,25- dihydroxyvitamin D3 receptor cDNA(C) JOURNAL: Proc. Natl. Acad. Sci. U.S.A.(D) VOLUME: 85(F) PAGES: 1005-1009(G) DATE: February-1988(xi) SEQUENCE DESCRIPTION: SEQ ID NO:4:ArgPheThrCysProPheAsnGlyAspCysArgIleThrLysAspAsn1 51015ArgArgHisCysGlnAlaCysArgLeuLysArgCysValAspIleGly202530MetMetLys GluPheIleLeuThrAspGluGluValGlnArgLysArg354045GluMetIleMetLysArgLysGluGluGluAlaLeuLysAspSerLeu50 5560ArgProLysLeuSerGluGluGlnGlnHisIleIleAlaIleLeuLeu65707580AspAlaHisHisLys ThrTyrAspProThrTyrAlaAspPheArgAsp859095PheArgProProValArgMetAspGlySerThrGlySerTyrSerPro10 0105110ArgProThrLeuSerPheSerGlyAsnSerSerSerSerSerSerAsp115120125LeuTyrThrThrSerLe uAspMetMetGluProSerGlyPheSerAsn130135140LeuAspLeuAsnGlyGluAspSerAspAspProSerValThrLeuAsp145150 155160LeuSerProLeuSerMetLeuProHisLeuAlaAspLeuValSerTyr165170175SerIleGlyLysVal IleGlyPheAlaLysMetIleProGlyPheArg180185190AspLeuThrSerAspAspGlnIleValLeuLeuLysSerSerAlaIle195 200205GluValIleMetLeuArgSerAsnGlnSerPheThrMetAspAspMet210215220SerTrpAspCysGlySerGlnAsp TyrLysTyrAspValThrAspVal225230235240SerLysAlaGlyHisThrLeuGluLeuIleGluProLeuIleLysPhe245 250255GlnValGlyLeuLysLysLeuAsnLeuHisGluGluGluHisValLeu260265270LeuMetAlaIleCysI leValSerProAspArgProGlyValGlnAsp275280285AlaLysLeuValGluAlaIleGlnAspArgLeuSerAsnThrLeuGln290 295300ThrTyrIleArgCysArgHisProProProGlySerHisGlnLeuTyr305310315320AlaLysMetIleGlnLysLe uAlaAspLeuArgSerLeuAsnGluGlu325330335HisSerLysGlnTyrArgSerLeuSerPheGlnProGluAsnSerMet340 345350LysLeuThrProLeuValLeuGluValPheGlyAsnGluIleSer355360365(2) INFORMATION FOR SEQ ID NO:5:(i) SEQUENCE CHARACTERISTICS:(A ) LENGTH: 1399 base pairs(B) TYPE: nucleic acid(C) STRANDEDNESS: double(D) TOPOLOGY: linear(ii) MOLECULE TYPE: cDNA(iii) HYPOTHETICAL: NO(iv) ANTI-SENSE: NO(vi) ORIGINAL SOURCE:(A) ORGANISM: Homo sapiens(x) PUBLICATION INFORMATION:(A) AUTHORS: Baker, Andrew R.McDonnell, Donald P.Hughes, Mark Crisp, Tracey M.Mangelsdorf, David J.Haussler, Mark R.Pike, J. W.Shine, JohnO'Malley, Bert W.(B) TITLE: Cloning and expression of full-length cDNAencoding human vitamin D receptor(C) JOURNAL: Proc. Natl. Acad. Sci. U.S.A.(D) VOLUME: 85(F) PAGES: 3294-3298(G) DATE: May-1988(xi) SEQUENCE DESCRIPTION: SEQ ID NO:5:GGAACAGCTTGTCCACCCGCCGGCCGGACCAGAAGCCTTTGGGTCTGAAGTGTCTGTGAG60ACCTCACAGAAGAGCACCCCTGGGCTCCACTTACCTGCCCCCTGCTCCTTCAGGGATGGA12 0GGCAATGGCGGCCAGCACTTCCCTGCCTGACCCTGGAGACTTTGACCGGAACGTGCCCCG180GATCTGTGGGGTGTGTGGAGACCGAGCCACTGGCTTTCACTTCAATGCTATGACCTGTGA240AGGCTGCAAAGGCTTCTTCAGGCGAAGCATGAAGCGGAAGGC ACTATTCACCTGCCCCTT300CAACGGGGACTGCCGCATCACCAAGGACAACCGACGCCACTGCCAGGCCTGCCGGCTCAA360ACGCTGTGTGGACATCGGCATGATGAAGGAGTTCATTCTGACAGATGAGGAAGTGCAGAG420GAAGCGGGAGATGATCCTGA AGCGGAAGGAGGAGGAGGCCTTGAAGGACAGTCTGCGGCC480CAAGCTGTCTGAGGAGCAGCAGCGCATCATTGCCATACTGCTGGACGCCCACCATAAGAC540CTACGACCCCACCTACTCCGACTTCTGCCAGTTCCGGCCTCCAGTTCGTGTGAATGATGG60 0TGGAGGGAGCCATCCTTCCAGGCCCAACTCCAGACACACTCCCAGCTTCTCTGGGGACTC660CTCCTCCTCCTGCTCAGATCACTGTATCACCTCTTCAGACATGATGGACTCGTCCAGCTT720CTCCAATCTGGATCTGAGTGAAGAAGATTCAGATGACCCTTC TGTGACCCTAGAGCTGTC780CCAGCTCTCCATGCTGCCCCACCTGGCTGACCTGGTCAGTTACAGCATCCAAAAGGTCAT840TGGCTTTGCTAAGATGATACCAGGATTCAGAGACCTCACCTCTGAGGACCAGATCGTACT900GCTGAAGTCAAGTGCCATTG AGGTCATCATGTTGCGCTCCAATGAGTCCTTCACCATGGA960CGACATGTCCTGGACCTGTGGCAACCAAGACTACAAGTACCGCGTCAGTGACGTGACCAA1020AGCCGGACACAGCCTGGAGCTGATTGAGCCCCTCATCAAGTTCCAGGTGGGACTGAAGAA108 0GCTGAACTTGCATGAGGAGGAGCATGTCCTGCTCATGGCCATCTGCATCGTCTCCCCAGA1140TCGTCCTGGGGTGCAGGACGCCGCGCTGATTGAGGCCATCCAGGACCGCCTGTCCAACAC1200ACTGCAGACGTACATCCGCTGCCGCCACCCGCCCCCGGGCAG CCACCTGCTCTATGCCAA1260GATGATCCAGAAGCTAGCCGACCTGCGCAGCCTCAATGAGGAGCACTCCAAGCAGTACCG1320CTGCCTCTCCTTCCAGCCTGAGTGCAGCATGAAGCTAACGCCCCTTGTGCTCGAAGTGTT1380TGGCAATGAGATCTCCTGA 1399(2) INFORMATION FOR SEQ ID NO:6:(i) SEQUENCE CHARACTERISTICS:(A) LENGTH: 2043 base pairs(B) TYPE: nucleic acid(C) STRANDEDNESS: double(D) TOPOLOGY: linear(ii) MOLECULE TYPE: cDNA(iii) HYPOTHETICAL: NO(iv) ANTI-SENSE: NO(vi) ORIGINAL SOURCE:(A) ORGANISM: Rat(x) PUBLICATION INFORMATION:(A) AUTHORS: Burmester, James K.Wiese, Russell J.Maeda, NobuyoDeLuca, hector F.(B) TITLE: Structure and regulation of the rat1,25- dihydroxyvitamin D3 receptor(C) JOURNAL: Proc. Natl. Acad. Sci. U.S.A.(D) VOLUME: 85 (F) PAGES: 9499-9502(G) DATE: December-1988(xi) SEQUENCE DESCRIPTION: SEQ ID NO:6:CGTCCACCGCCAGACCAGAGTTCTTTTGGTCGGACAGATCTGTGAGACTTCCAGGAGAGC60ACCCTTGGGCTCTACTCACCCTGCTCCTTCAGGGATGGAGGCAACAGCGGCCAGCACCTC120CCTGCCCG ACCCTGGTGACTTTGACCGGAACGTGCCCCGGATCTGTGGAGTGTGTGGAGA180CCGAGCCACAGGCTTCCACTTCAATGCTATGACCTGTGAAGGCTGCAAAGGTTTCTTCAG240GCGGAGCATGAAGCGGAAGGCCCTGTTCACCTGTCCCTTCAATGGAGATTGCC GCATCAC300CAAGGACAACCGGCGACACTGCCAGGCCTGCCGGCTCAAACGCTGTGTGGACATCGGCAT360GATGAAGGAGTTCATCCTGACAGATGAGGAGGTACAGCGTAAGAGGGAGATGATAATGAA420GAGAAAAGAGGAAGAGGCCTTGAAGGACAG TCTGAGGCCCAAGCTATCTGAAGAACAACA480GCACATCATAGCCATCCTGCTGGACGCCCACCACAAGACCTATGACCCCACCTACGCTGA540CTTCAGGGACTTCCGGCCTCCAGTTCGTATGGACGGAAGTACAGGGAGCTATTCTCCAAG600GCCCACAC TCAGCTTCTCCGGGAACTCCTCCTCCTCCAGCTCTGACCTGTACACCACCTC660ACTAGACATGATGGAACCATCCGGCTTTTCCAACCTGGATCTGAACGGAGAGGATTCTGA720TGACCCGTCTGTGACTCTGGACCTGTCTCCTCTCTCCATGCTGCCCCACCTGG CTGACCT780TGTCAGTTACAGCATCCAAAAGGTCATCGGCTTTGCCAAGATGATCCCAGGATTCAGGGA840TCTCACCTCCGATGACCAGATTGTCCTGCTTAAGTCAAGCGCCATTGAGGTGATCATGTT900ACGCTCCAACCAGTCTTTCACCATGGATGA TATGTCCTGGGACTGTGGCAGCCAGGACTA960CAAGTACGACGTCACCGATGTCTCCAAAGCTGGGCACACCCTGGAGCTGATCGAGCCCCT1020CATAAAGTTCCAGGTGGGGCTGAAGAAGCTGAACTTACATGAGGAAGAGCATGTCCTTCT1080CATGGCCA TCTGCATTGTCTCCCCGGACCGACCTGGGGTCCAGGACGCCAAGCTGGTGGA1140AGCCATTCAGGACCGCCTATCCAACACGCTGCAGACCTACATCCGCTGCCGCCACCCGCC1200CCCAGGCAGCCACCAGCTCTATGCCAAGATGATCCAGAAACTGGCCGACCTGC GGAGCCT1260CAACGAGGAACACTCCAAACAATACCGCTCCCTCTCCTTCCAGCCCGAGAATAGCATGAA1320GCTCACACCCCTTGTGCTGGAGGTGTTCGGCAATGAGATCTCCTGACCAGGGTGGCCCAC1380AGTGGTGCCTGGGTAGGGCCGCTCCTCCAG AGCCCTGTGCCCAGGCCCTGGGCTTGGTTG1440CAGCCCAGCAGTGCCTCCTGCCCTTTCTGGAGTTCAGTCCTTCCTCTGCCATGGCCTCTG1500TCTGTCTGCCTCATCCTTTCTCCTGCCCAGCCTAACACCTGGTCTCCCTTTCCTGTAGAC1560CTCGAGTT GCTCCTGTCTCTTGAGACCTCAGTTAGGAGAGGCTGCTGTTTATCTGACAAA1620GGAACTCAATTGGGGATAGAGGGCAGGGGCTGAAGGCGGAACTCTGCCTAGGGGATGCCT1680CCACCACAAGGGGCTGCTGCTTGTGTCAAGGGAGGCAGGCAGAAGAGACGCAT TCACTCC1740TCAGGGACAGGTACCTGCACCTCCCCTCACTCCAGCCCTACCTGCCCAAAGCCTAGTGAG1800AAATCTGGCCCCTGCCTGCGAAGGGTACACAACCTACCCATCATCCCTACTGTGTCCCGT1860CTCGTCCTGCCGCCTGTCTGTGTTATTCTG ACCCGGGGGAGTAGGTCACTGAGGGGCCTC1920CTTCCTCTGCCTTTATACTCACGGGGCTCACTCACTGCCAAGATGACCAAATACACTACC1980ACACGAACCAAGGAGCACTCACCCAGCCCTGCAGTTCCCACCTTTGAGGTTTTGCCATGG2040GAA 204
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A method of producing 1,25-dihydroxyvitamin D 3 receptor protein is disclosed. A DNA sequence is transcribed to form an RNA sequence which encodes animal vitamin D receptor. Receptor protein is expressed from the RNA sequence. The RNA sequence contains less than the full 5' and 3' non-translated flanking sequences present in the natural form of the RNA sequence. Receptor protein produced by the above method, expression systems used in the method, and plasmids useful in constructing such expression systems are also disclosed.
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FIELD OF THE INVENTION
The present invention relates to a method for protecting a torque converter from overheating and a traction control system including a converter protection function.
BACKGROUND INFORMATION
When starting off on a road surface having different adhesive friction values between the right and left sides of the vehicle (μ-split), even when a relatively slight drive torque is applied, the wheel (low-μ wheel) located on the slippery side of the road surface begins to spin. If the speed of the low-μ wheel exceeds a specific slip threshold, the traction control system (TCS) intervenes in the operation of the vehicle and brakes the slipping wheel.
The braking torque exerted on the low-μ wheel is transferred via the differential to the wheel on the non-skid side of the road surface (high-μ wheel) and may be used there for the propulsion of the vehicle.
With a regulation of this type, the brake intervention on the slipping wheel converts the engine torque in the brake into heat. In vehicles with automatic transmission, this also has the consequence that the engine torque produced (less the torque acting in the brake) is converted into thermal energy in the torque converter of the automatic transmission, which may destroy the torque converter or the transmission even after a relatively short time.
During standing-start operations under μ-split conditions, situations may arise in particular with heavily loaded vehicles or vehicles with trailers in which the vehicle does not begin to move despite maximum drive torque, since the braking resistance torque and rolling resistance torque of the vehicle and the downgrade force acting on the vehicle and trailer are greater than the engine torque produced by the engine. In such situations, the result is an extreme load and a correspondingly rapid overheating of the torque converter.
Other traction control systems therefore include a converter or transmission protection function, which is implemented using a time counter, which is started in the control state “select high” when starting off on μ-split and below a vehicle speed of 5 km/h and which causes a forced switch into the state “select low” after a specified period of time (e.g., 15 seconds).
The state “select high” of a TCS is used to attain the maximum possible traction and is characterized by high slip thresholds for the drive wheels and a relatively high delivery of engine torque. In contrast, the state “select low” is used to attain the maximum possible vehicle stability and is characterized by slip thresholds set to be very sensitive and a correspondingly low engine torque.
The protective function of other systems provide that the TCS performs a rigid (time-controlled) switch independent of the actual load on the torque converter. Thus the speed of a vehicle moving slowly forward with slipping drive wheels may be limited just before reaching a non-skid road surface, although the temperature reached in the torque converter would not have required this yet.
SUMMARY OF THE INVENTION
The present invention provides a converter protection function for a traction control system to the effect that the engine torque is reduced when it is actually necessary to protect the converter.
BRIEF DESCRIPTION OF THE DRAWINGS
FIG. 1 shows a flow chart to explain a method for protecting a torque converter from overheating according to one exemplary embodiment of the present invention.
FIG. 2 shows a schematic representation of a traction control system.
DETAILED DESCRIPTION
The sequence of a method for protecting a torque converter from overheating is shown in FIG. 1 in the form of a flow chart. In a first step 1 , the energy loss M CONVERTER — LOSS or a value proportional to it is calculated and this value is compared with a specified threshold value in Step 2 .
If the energy loss converted in the torque converter is greater than threshold value sw, the engine torque is reduced in step 3 , otherwise the current engine torque is maintained.
FIG. 2 shows a traction control system 4 including a device 5 for determining the energy loss converted in the torque converter or a value proportional to it. The current braking torque M BRAKE and the current engine torque M ENGINE are supplied to traction control system 4 . As was described above, engine torque M ENGINE is reduced if the converter energy loss or the proportional value exceeds a specified threshold value.
In particular, an exemplary embodiment includes calculating the energy loss converted in the torque converter or a value proportional to it and reduce the engine torque if the energy loss or the proportional value exceeds a specified threshold value. The energy loss or the proportional value represents a measure of the temperature prevailing in the torque converter, which is accordingly only reduced if the converter temperature requires it.
Also, according to an exemplary embodiment, a torque balance is performed relative to the propulsion and deceleration moments acting on the vehicle, from which a converter torque loss is determined. The converter torque loss is integrated over time and thus forms a reference value, which is a measure of the energy dissipation converted in the torque converter and accordingly the converter temperature.
In calculating the energy loss converted in the torque converter or the proportional value, the heat dissipation of the torque converter may be taken into consideration.
The TCS, which is in the state “select high” at the beginning of the starting-off operation, may switch to the state “select low” if the energy loss converted in the torque converter or the value proportional to it exceeds the specified threshold value.
During standing-start under μ-split conditions, a wheel located on the slippery side of the road surface begins to slip due to the engine torque applied by the driver. The TCS recognizes this and regulates an appropriate brake pressure on the low-μ wheel. Since the vehicle does not drive off, the engine torque delivered is converted into heat in the torque converter and in the brake and into acceleration in the drive train. The following relationship applies:
M ENGINE =M BRAKE +M CONVERTER — LOSS +M WBR , where
M ENGINE : engine torque produced M BRAKE : braking torque converted in the brake M CONVERTER — LOSS : torque loss which heats the converter M WBR : rotational acceleration resistance torque of the drive train
The acceleration of the drive train lasts for only a short period of time. Afterwards, a steady state prevails, i.e., the angular acceleration is equal to zero as is the rotational acceleration resistance torque M WBR as well. In the steady state, the following equation applies to the torque loss of the converter M CONVERTER — LOSS :
M CONVERTER — LOSS =M ENGINE −M BRAKE
For the brake pressure P BRAKE delivered by the TCS, the following applies:
M BRAKE =P BRAKE *C,
C being a conversion constant (Nm/bar).
Taking into consideration the rotational acceleration resistance torque M WBR of the drive train, the following applies:
M WBR =M WBR — ENGINE +M WBR — DRIVETRAIN with
M WBR =J ENGINE *ω ENGINE +J DRIVETRAIN *ω DRIVETRAIN , where
J: mass moment of inertia [kgm 2 ] ω: angular acceleration [l/s 2 ]
Both the engine speed and the wheel speeds are known as are the individual mass moments of inertia J of the drive train.
To determine the energy loss converted in the converter, the converter torque loss M CONVERTER — LOSS is integrated over time. In doing so, the energy dissipation, through convection and thermal radiation in particular, which causes a reduction in temperature, may also be considered. With iterative calculation (index t), the following applies:
M CONVERTER — LIMIT =M CONVERTER — LIMIT(t-1) +dM CONVERTER — LOSS *dt−dM CONVECTION *dt where
dM CONVECTION : application parameter.
If converter limit torque M CONVERTER — LIMIT , which is specified as the threshold value, is exceeded the operating state of the TCS is switched from “select high” to “select low,” i.e., the engine regulates very sensitively.
According to another exemplary embodiment, a temperature model may be used to determine the temperature of the torque converter. The temperature model is a computer model which describes the thermal characteristics of the torque converter under different propulsion and braking conditions. As an input variable, the temperature model includes, for example, the converter torque loss and may also take the heat dissipation into consideration.
The TCS may switch from “select high” to “select low” if the temperature determined by the temperature model exceeds a specified threshold value.
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A method and a device for protecting a torque converter of an automatic transmission from overheating during standing-start of a motor vehicle, a slipping wheel being decelerated by a traction control system by a braking intervention. To improve the protective function of the traction control system, the energy loss converted in the torque converter or a value proportional to it is calculated and the engine torque is reduced if a specified threshold value is exceeded.
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FIELD OF THE INVENTION
The present invention pertains generally to the field of geometrical instruments, more particularly to the field of celestial instruments having a gnomonic indicator.
BACKGROUND
School children are taught about how the earth is round and orbits around the sun and about the earth's declination on the orbit and how this results in the four seasons. Yet when one goes outside, the earth looks flat and the sun is somewhere in the sky, and it is difficult to fully grasp or appreciate the geometry involved. In addition, modern air travel has greatly shortened the time and effort required to travel great distances around the globe. One crosses multiple time zones, experiences jet lag and may experience different climates or reversal of the seasons upon travel to the opposite hemisphere. Yet the geometry behind this can remain somewhat obscure and theoretical.
Thus, there is a need for a portable device that can be easily carried on trips to enhance the appreciation of the concepts of latitude and longitude, and timekeeping and how these concepts relate to the daily and annual movements of the sun and the stars.
BRIEF DESCRIPTION OF THE INVENTION
Briefly, the present invention relates to a celestial navigation device. A full-featured embodiment is useful as a sundial and planisphere and for measuring, among other things, latitude, longitude, and for time to angle conversions. The device may have one or more rings and is based on a transparent circular tube having a gravity indicator, typically a ball or bubble, in the circular tube, which locates the lowest or highest point in the tube to indicate time or angle measurements against a corresponding scale. The device may have a 24-hour time scale, a calendar scale, and/or an angle scale. One embodiment includes a split analemma with separate north and south portions. Each analemma portion is used with a corresponding gnomon of a pair of gnomons, each on opposite sides of the tubular ring. A two-ring embodiment has an inner ring and outer ring rotatably slidable relative to one another. Two additional gnomons and star position marks may be provided for star sighting observations. The device has a hollow center and may be worn as a bracelet and may be constructed with precious metals and/or gems to enhance the value of the bracelet aspect.
These and further benefits and features of the present invention are herein described in detail with reference to exemplary embodiments in accordance with the invention.
BRIEF DESCRIPTION OF THE FIGURES
The present invention is described with reference to the accompanying drawings. In the drawings, like reference numbers indicate identical or functionally similar elements.
Additionally, the left-most digit(s) of a reference number identifies the drawing in which the reference number first appears.
FIG. 1 illustrates a top view of an exemplary sundial in accordance with the present invention, showing the north face with an hour scale on the inner ring and an angle scale on the outer ring.
FIG. 2 illustrates a bottom view of an exemplary sundial in accordance with the present invention, showing the south face with an hour scale on the inner ring and a calendar scale on the outer ring.
FIG. 3 illustrates a cross section through an exemplary sundial in accordance with the present invention.
FIG. 4 illustrates a cross section through an alternative exemplary sundial in accordance with the present invention.
FIG. 5 shows a side view of the sundial of FIG. 1 and FIG. 2 .
FIG. 6 shows an exemplary analemma ticket for use with the ring of FIG. 1 to form a sundial.
FIG. 7 shows the sundial configured to measure solar time.
FIG. 8A and FIG. 8B show summer and winter alignments, respectively, for measuring solar time.
DETAILED DESCRIPTION OF THE INVENTION
The present invention relates to an ornamental bangle which allows the bearer to estimate his/her longitude and latitude from the sun and stars.
One exemplary embodiment comprises a bangle comprised of approximately one centimeter diameter transparent tubular material formed into a ring of approximately 7 cm inside diameter and sheathed on the inside to form an additional ring of half cylinder cross section which may slide in relation to the first mentioned ring. The former containing either a small sphere which can roll within the lumen of the first ring or be filled with liquid excepting a small bubble of air either of which will act as the indicator. The sheath modified to accept a 13 mm×32 mm ticket on its inner surface perpendicular to the plane of the rings on the surfaces of which is printed an analemma. The inner ring forming the sheath having the numerals of a 24 hour clock printed on its lateral surfaces and a directional inscription on the inner surface. The outer tubular ring on its outer half having the degrees of longitude printed on one lateral surface and the days of the year on the remaining lateral surface. The hours, degrees, and days aligning to form an analog slide rule for calculating time vs. longitude and the opposite surface a planisphere for calculating the ecliptic. The inner surface of the inner ring having printed on its concave surface (visible through the transparent outer ring) the longitude and latitude of forty major cities, i.e., an alpha numeric map of the earth. The inner ring having four gnomons, one each of a first pair on opposite sides of the ring at the 12 midnight position and one each of a second pair on opposite sides at a 12 o'clock noon position.
The inner ring is aligned with its axis north and south and its gnomon's solar shadow positioned to fall on the analemma giving thus by the indicator solar time. Held with its axis in an east west direction at noon and setting the declination indicated on the analemma for the day in question to the noon gnomon the bracelet indicates latitude when the sun's shadow is cast on the mean solar time line of the analemma.
The outer ring is marked with two luminescent dots on either face which represent specific stars and when aligned as a planisphere with the day's date on the 12 noon gnomon the bracelet will indicate solar time at night. The gnomon when aligned with the 90 degree marks on the outer ring and then aligned with the North Star gives declination and therefore latitude at night. Solar time day or night is converted to longitude with the analog slide rule by first setting the zero degree mark at Mean Greenwich time and reading longitude at solar time.
The present invention will now be described in detail with reference to the figures.
FIG. 1 illustrates a top view of an exemplary sundial in accordance with the present invention, showing the north face with an hour scale on the inner ring and an angle scale on the outer ring. Referring to FIG. 1 , the sundial comprises two rings, an inner ring 104 and an outer ring 102 that may slidably rotate relative to one another. The inner ring 104 is shown with an hour scale 108 a for time measurements and settings. The inner ring 104 also includes two gnomons 106 a and 106 b as shown on the top and two more directly underneath on the underside ( 106 c and 106 d of FIG. 2 ). The outer ring 102 is shown with an angle scale 110 marked in degrees which may be used for various angle measurements and settings. The outer ring 102 comprises a partial or complete circular cross section tube. The tube is preferably transparent and contains a leveling indicator 118 (also referred to as a gravity indicator) freely traveling within the tube. In one embodiment, the leveling indicator 118 may be a spherical object freely rolling within the tube to indicate the lowest point and may be read against the angle scale 110 or hour scale 108 a . The leveling indicator may be any spherical object of sufficient durability including but not limited to glass, plastic, metal (aluminum, stainless steel), and in keeping with the bracelet embodiment, may be pearl, silver, or a gemstone. In an alternative embodiment, the tube may be filled with a liquid leaving a bubble or floating sphere as the level indicator—in which case the indication would be at the top rather than the bottom of the ring. The liquid may include but is not limited to water, alcohol, or antifreeze.
The outer ring 102 may be any transparent or translucent material sufficiently transparent to observe the level indicator 118 within. Clear plastic tubing is preferred for durability. The outer rim of the outer ring includes numerical angle values 114 for each 30 degrees on the angle scale. The numerical angle values 114 are positioned right side up as viewed from above the topside 100 center of the ring, viewing across the angle scale 110 . Also shown are month label markings 112 for a month scale on the opposite side ( FIG. 2 ). The month markings 112 are interleaved with the angle markings 110 and are upside-down as viewed on the topside 100 because they are to be viewed with reference to the month scale on the bottom side ( FIG. 2 ).
The inner ring 104 comprises a half circle cross section annular ring that slidably rotates relative to the outer ring 102 . The inner ring 104 has a time scale 108 a showing 24 hours in the 360 degrees of the ring. The time scale 108 a is marked in hours with ten-minute dots and 30-minute marks between each hour. Two 12-hour periods are shown. Alternatively a single 24-hour period could be used. The inner ring 104 includes two gnomons 106 a and 106 b on the topside 100 , one at each 12-hour mark, and two additional gnomons on the bottom side (see FIG. 2 ). The gnomons are used as indicators in various measurements that may be made with the device. Each gnomon is preferably a short half circle cross section as sharp features are preferably avoided to prevent injury to a wearer of the bracelet embodiment. The half circle diameter and thus the width of the gnomon 106 a and 106 b at the base is preferably 2 mm for an exemplary bracelet embodiment. One to three millimeters diameter is desirable, with a height less than 4 millimeters being preferred for a bracelet. Other sizes and shapes may be used. The short and round gnomon shown is desirable for a bracelet embodiment because it will not easily catch on things and be damaged or cause damage. A non-bracelet embodiment may have less reason to prefer a small gnomon. The gnomon being on one side of the ring across the center (diameter) of the ring from the analemma, is twice as sensitive in indicating time as a gnomon located in the center of the ring and more sensitive than gnomons located above the ring, as may be provided in prior art sundials.
The inner ring 140 typically comprises an opaque material; however, the inner ring may be transparent if desired. The material may include plastic, metal, wood or other stable material. In one embodiment, the inner ring 140 may be silver or gold for greater decorative value and greater appeal as a bracelet.
The inner ring also includes a marking “N” 116 to identify the face as the North face 100 to be positioned toward the north when the device is used in the sundial configuration.
Also shown is an analemma ticket holder 120 . The sundial configuration also comprises an analemma ticket as a separable component that may be carried separately and installed in the analemma holder when the device is used in the sundial configuration. The analemma ticket is a flat rectangular piece with an analemma pattern printed thereon for use in various measurements. The card is inserted into the analemma holder with the equator line flush with the north or south face of the sundial. The analemma holder 120 is provided with rounded points to avoid injuring someone wearing the ring as a bracelet. FIG. 6 and associated text.
The ring may be made any size as desired for the sundial. In one particular embodiment, the ring may also be worn as a bracelet. The ring may be made from materials desirable as jewelry to enhance the appeal of the device as a bracelet, thus encouraging the owner to take the device on trips around the world, during which the device can be used to better appreciate the context of the earth's relationship to the sun and stars and the basis of our timekeeping. In one exemplary bracelet embodiment, the inside diameter may be 67 mm. Typical bracelets are in the range from 63 mm to 76 mm inside diameter. Smaller diameters may be made for children. Larger diameters may be made for specialty purposes, but may have less mass market appeal.
Cross section 3 is shown in FIG. 3 with an alternative shown in FIG. 4 .
FIG. 2 illustrates a bottom view of an exemplary sundial in accordance with the present invention, showing the south face with an hour scale on the inner ring and a calendar scale on the outer ring. Referring to FIG. 2 , the inner ring 104 comprises a time scale 108 b corresponding to the time scale 108 a on the top side, i.e., each scale number is the same as the one directly opposite on the north face 100 (top side), i.e., as if seen directly through the ring 104 . The south face 200 (bottom side) of the inner ring 104 also includes two gnomons 106 c and 106 d at the 12 hour positions directly opposite the corresponding gnomons 106 a and 106 b on the north face 100 .
The south face 200 also includes a calendar scale 202 on the outer ring 102 instead of the angle scale shown on the north face. The calendar scale 102 has major ticks at the first of each month, intermediate ticks at ten day intervals and small ticks at five day intervals between the ten day intervals. The day intervals are measured from the beginning of each month and restart at the beginning of each month. As an additional (alternative) indication of the day of the month, the text 112 indicating the month may be a three character abbreviation of the month and is placed with the center of each character at the 10, 15, and 20 day points from the beginning of the month. Alternative meaningful intervals include the 7, 14, and 21 day points. The text 112 is oriented to be read right side up from a viewpoint over the center of the south face 200 . The month name text 112 shown in FIG. 2 is printed on the rim of the tubular outer ring 102 so that only the bottom half of the characters are visible in the view.
FIG. 2 also shows two dots 204 and 208 on the month scale 202 , not indicating time, but indicating angle to a particular star, for use in nighttime measurements. One dot 204 is positioned at about March 8 and represents the angle of the star Dubhe, the pointer star on the lip of the bowl in the Big Dipper, Ursa Major. The other dot 208 is at about September 20 and represents the angle to Caph in Cassiopeia, which may be used if Dubhe is below the horizon. Dot 204 may be one color and dot 208 may be another color to distinguish them, for example blue and red respectively. The dots 204 and 208 may be luminescent or may include white, or otherwise made to be visible at night. The use of these dots will be described later. Southern hemisphere stars may also be included, for example Beta Carina and Alpha Triangulum Australis. Other stars may be chosen as desired.
The south face also includes a marking “S” 206 indicating the south face. The south face faces toward the south for sundial time measurements.
FIG. 3 illustrates a cross section through an exemplary sundial in accordance with the present invention. Referring to FIG. 3 , the inner ring 104 and outer ring 102 each comprise a half shell that, when joined, forms a complete tubular ring. The inner shell 104 and outer shell 102 may slide to allow independent rotation about the ring center along an interlocking junction 302 . The inner ring 104 is typically opaque, preferably an ivory colored plastic. Other materials may be used. The outer ring is sufficiently transparent to view the gravity indicating ball 118 in the tubular structure. The gravity indicating ball 118 is preferably a white ball for clear viewing at night. Other colors may be used. The ball materials include white plastic, glass, silver, pearl or any other stable, solid, round material. Pearl may enhance the sundial's appeal as a bracelet. In a bracelet embodiment, an exemplary gravity indicating ball may be 3.5 mm in diameter, but any convenient size may be used. Also shown are the gnomons 106 b and 106 d attached at the 12 hour mark near the analemma holder 120 . A cross section through the analemma holder 120 shows the flat back surface and holder arms.
FIG. 4 illustrates a cross section through an alternative exemplary sundial in accordance with the present invention. Referring to FIG. 4 , the inner ring 104 comprises an annular half shell riding on a tubular ring forming the outer ring 102 . The gravity indicator 118 rides within the outer ring tube 102 . In one embodiment, the outer ring 102 may have a continuous cross section. In another embodiment, the outer ring may have a split 402 on the inside rim, as shown in FIG. 4 . If the plastic forming the outer ring 102 is sufficiently flexible, the tube may be opened at the split 402 to insert the gravity indicator 118 . Heat may be applied to improve flexibility.
In an alternative embodiment, the tube 102 of FIG. 4 (sealed, without the split 402 ) may be filled with liquid and the gravity indicator 118 may be lighter than the liquid, such as a hollow ball, or light plastic; or the gravity indicator 118 may be a bubble in the liquid. The lighter than liquid indicator will indicate at the top of the ring rather than at the bottom and the appropriate angle measurements are adjusted for the difference, as will be described later.
In one embodiment, the concave surface of the inside of the inner ring (between the inner ring and the outer ring) may have an inscription of any sort because the inner ring may be read through the transparent outer ring. In particular, the surface may contain an alphanumeric map of the world, i.e., a list of city codes and associated latitude and longitude values for each city. An exemplary map inscription may include the following cities and associated lat-long values:
Line 1:
DUB 53N 6W AZO 39N 27W PAR 49W 2E ROM 42N 12E MOS 56N 38E MEC 21N 40E CPT 34S 18E MAN 15N 121E
Line 2:
LON 51N 0W GIB 36N 5W AMS 52N 5E OSL 60N 42E CRO 30N 31E BOM 19N 73E BKK 14N 101E TKO 36N 140 E
Line 3:
LIS 38N 9W MAD 40N 4W BER 53N 13W ATN 38N 24E JER 32N 35E BAG 33N 44E SGP 1N 104E SGH 31N 121E
Line 4:
SYD 34S 151E STK 57N 135W LAX 34N 118W MIA 26N 80W NYC 48N 74W STG 33S 71W BAR 13N 60W
Line 5
AKL 37S 175E SEA 48N 122W DEN 40N 105W VRC 19N 96W PMC 9N 80W BNA 35S 58W BRM 33N 65W
Line 6
HAW 21N 132W TAH 18S 150W NOR 30N 90W TEG 14N 87W QTO 0N 77W RIO 23S 43W PTR 18N 66W
This inscription space may also be used for a table of cosine values and associated degrees, which may be used for some measurements which may be made with the device. Also, the cosine table may be used to find distance between cities on the map by noting that at the equator, one degree longitude is about 100 kilometers (more precisely 111 km). Higher latitudes are reduced by the cosine of the latitude. The cosine value table may be inscribed as follows:
/1 /98 /94 /87 /77 /64 /50 /34 /17 /0 COS
0 10 20 30 40 50 60 70 80 90 DEG
If additional space is needed, the inside of the inner ring may also be used for inscriptions. In particular, the inventor finds the following inscription in keeping with the spirit of finding guidance from the heavens:
TRUST IN THE LORD WITH ALL YOUR HEART AND DO NOT RELY ON YOUR OWN UNDERSTANDING THINK ABOUT HIM IN ALL YOUR WAYS AND HE WILL GUIDE YOU ON THE RIGHT PATHS.
FIG. 5 shows a side view of the sundial of FIG. 1 and FIG. 2 . FIG. 5 shows the tubular ring 102 with the angle markings 114 for the angle scale 110 on the north face 100 , (top side) and the month labels 112 for the calendar scale 202 on the south face 200 (bottom side). Two gnomons 106 b and 106 d are seen, one on the north face 100 and another on the south face 200 .
FIG. 6 shows an exemplary analemma ticket for use with the ring of FIG. 1 to form a sundial. The analemma ticket 600 of FIG. 6 comprises a base material on which an analemma pattern 608 is printed. A time scale is efficiently displayed along the analemma. The time scale comprises twelve points 610 that indicate the beginning of each month together with the three letter abbreviation 612 for each month. The three letters 612 provide the dual function of indicating the month and serving as day markers within the month. Each of the three letters indicates a span of about one third of the month, i.e. ten days. Thus each letter may be centered on an associated ten day span. Also, each letter may be stretched to span each ten day span. Thus, the letters may provide scale resolution in addition to indicating the month.
The analemma ticket 600 also includes a declination scale 616 for finding the earth's declination according to the calendar scale 610 , 612 on the analemma 608 . To find declination, one finds the calendar date point on the analemma for the current date and then reads across to the declination scale 616 to find the earth's declination at that calendar date. Also included on the ticket is a centerline 614 (also referred to as the mean solar noon line 614 ) for use in latitude measurements.
In accordance with one embodiment of the present invention, the analemma ticket 602 may be folded or cut at the equator line 606 , or each half 602 , 604 may be printed on opposite sides of a single ticket 600 . Each side of the ticket would be used during the associated time interval shown on the ticket, i.e., a first half ticket, labeled “S,” would include north declinations from the spring to the fall equinox, and a second half ticket, labeled “N,” would include south declinations from the fall to the spring equinox. The first half ticket is labeled “S” because the analemma shadows for northern declinations fall lower on the ticket. Thus the “S” ticket is mounted extending below the “S” face of the ring, and conversely for the second “N” half of the ticket.
The analemma ticket is placed in the analemma holder and positioned so that the equatorial line is flush with the north face or south face of the sundial ring. The face selected depends on the ticket chosen. See FIG. 7 . The analemma ticket may be made of a durable plastic, metal, paper or other sheet material. The ticket may be carried independently of the ring, e.g., the ticket may be carried with credit cards in a wallet or handbag. Alternatively, the ticket may be attached by a decorative chain to the ring, allowing the ring to be worn as a bracelet without the interference of the analemma ticket as would be encountered with the ticket permanently installed in the ring for use as a sundial. In one exemplary embodiment, the analemma ticket may be 13 mm wide and 32 mm long, from one end to the equator line 606 . The size of the analemma ticket 600 is primarily determined by the distance from the gnomon 106 a to the analemma ticket 600 , since the analemma itself is defined by angles that are fixed by the earth's declination and orbit. Thus if the sundial is scaled to a different ring size, the analemma would also be scaled proportionately.
The dual (split) analemma works with the dual gnomons on the north and south face to permit a more compact assembled package by allowing the analemma to occupy interior space in the ring and thus protrude outside the ring by a smaller amount than would otherwise be the case. Thus, the assembled size is reduced by at least two characteristics: first, the analemma is divided in half, and second, the half is positioned to utilize interior ring space. Since the two halves are not used simultaneously, each half may separately occupy the same interior space, reducing the total length occupied by the analemma by the width of the ring. The dividing in half of the analemma has the further advantage of increasing the strength and durability of the analemma ticket by reducing the tendency to bend or flex the ticket.
FIG. 7 shows the sundial configured to measure solar time. Referring to FIG. 7 , northern declination (summer in northern hemisphere) side 602 of the analemma ticket is installed in the analemma holder 120 with the equatorial line 606 flush with the north face 100 of the sundial. Note that in the summer (in the northern hemisphere) when the sun moves north to higher declinations, the shadow will move lower. Thus the analemma ticket 602 extends downward from the ring past the south face 200 of the ring. The shadow 702 of the north face gnomon 106 b is positioned at today's date on the analemma with the gnomon 602 b center providing vertical alignment and the north face 100 of the ring providing horizontal alignment to the analemma.
Note that the operational device with the analemma ticket installed has a thickness parallel to the ring axis which is less than the full height of the analemma pattern shown in FIG. 6 . The thickness being maximum at the analemma ticket, where the thickness is only slightly greater than half of the full analemma pattern, i.e., the length of one analemma ticket plus the height of one gnomon. Thus, the use of the analemma ticket with half of the full analemma pattern reduces at least one size envelope dimension for the device, in particular, the overall thickness (perpendicular to the plane of the ring). The thickness is further reduced by placing the equatorial line of the half analemma even with one face of the ring and extending the half analemma through the interior of the ring.
FIG. 8A and FIG. 8B show summer and winter alignments, respectively, for measuring solar time.
Referring to FIG. 8A , the sundial ring is shown with the analemma ticket extending below the south face 200 of the ring. The ring is aligned with the plane of the ring 804 parallel to the plane of the earth's equator and the axis of the ring 806 parallel to the earth's rotation axis. In the summer (northern hemisphere), the sun's rays 802 a come from above the equatorial plane, producing a shadow 808 a of the north face gnomon 106 a that shines through the center of the ring to the analemma ticket 602 below.
Referring to FIG. 8B , the sundial ring is shown with the analemma ticket extending above the north face 100 of the ring. The ring is aligned with the plane of the ring 804 parallel to the plane of the earth's equator and the axis of the ring 806 parallel to the earth's rotation axis. In the winter (northern hemisphere), the sun's rays 802 b come from below the equatorial plane, producing a shadow 808 b of the south face gnomon 106 c that shines through the center of the ring to the analemma ticket 604 above.
Using the Celestial Navigation Bracelet
If one were to possess a water filled glass globe with a map of the earth and lines of latitude and longitude marked on the globe, and if one were to orient the globe's axis parallel to the earth's axis and its face towards the sun in the same way the earth is oriented, then a small bubble in that globe would indicate one's exact position on the earth no matter where one travels on earth. The celestial navigation device can utilize this principle for making measurements, yet is compact, rugged, and free of protrusions so that the device may be carried in a pocket or worn as a bracelet on the wrist.
To Determine Mean Sun Time
From the northern hemisphere face south and hold the instrument in front of you with the rotation axis in a vertical north-south plane. Place the analemma in the analemma holder with the face containing today's date towards the center of the bracelet. The equatorial line 606 of the analemma 600 should be flush with the edge 100 or 200 of the instrument. Now, while maintaining the instrument's rotation axis 806 in the vertical north south plane, tilt the top of the instrument toward or away from you until the shadow of the gnomon 106 a or 106 c located on the same side as the equatorial line falls on today's date on the analemma. (i.e., use the gnomon 106 a or 106 c corresponding to the analemma side 602 or 604 being used) The instrument may be rotated about the axis and the axis may be tilted up or down to achieve the gnomon shadow alignment, but the axis must remain in the north-south vertical plane. Once the gnomon shadow is aligned with the analemma at today's date, the bubble indicator 118 of the bubble embodiment will indicate the sun time on the time scale. The pearl indicator 118 of the pearl embodiment will be 180 degrees on the angle scale or 12 hours on the hour scale from the correct sun time.
To Determine Latitude
To determine latitude by day, the instrument is held vertically in a north-south plane to observe the angle of the sun at noon. The north face, having the angle scale is used for the measurement. First, insert the analemma ticket in the ticket holder and rotate the inner ring relative to the outer ring so that the north face 100 gnomon 106 a (opposite the analemma holder 120 ) is at the angle of the sun's declination for the calendar day as read from the angle scale 110 . The sun's declination may be read from the analemma ticket 600 by finding the present calendar day on the analemma pattern 608 and then reading across to the declination scale 616 to find the sun's declination. Next, hold the instrument so that the plane of the ring is in a north-south vertical orientation. Rotate the instrument on its axis until the shadow of the gnomon 106 a aligns with the mean solar noon line 614 of the analemma ticket. In a version with a floating ball or bubble indicator 118 , the indicator 118 will float to the top and will now indicate the latitude on the angle scale 110 . In an instrument with a heavy indicator, the indicator will find the lowest point, and the latitude will be 180 degrees from the indictor 118 location read from the angle scale 110 , or 12 hours around on the hour scale 108 a.
The geometry is easier to visualize if one considers the measurement taking place at the equator. When setup, the zero degree mark on the scale would be vertical and the gnomon 106 a would be aligned with the sun, the mean solar noon line 614 and the sun's declination on the angle scale 110 . Southern declinations would be used in winter and northern declinations for summer.
To find latitude at night, the two north face 100 gnomons 106 a and 106 b are used to sight the North Star. The analemma ticket 600 is removed for this measurement. Place the gnomons 106 a and 106 b at the 90 degree marks on the angle scale 110 . Hold the instrument so that the ring is in a vertical north-south plane. Initially, place the zero degree mark up for the floating indicator and down for the heavy indicator. Rotate the instrument while keeping the inner and outer rings fixed relative to one another to align the two gnomons 106 a and 106 b with the North Star, i.e., sight from one gnomon over the top of the other gnomon to the North Star. The indicator 118 will now indicate the latitude as the angle scale value 110 at the indicator 118 , e.g., bubble or pearl.
Since the North Star is about ¾ degree from true north in the direction of the little dipper, a slight correction in latitude may be made by observing the angle and direction of this offset. The cosine table inscribed on the device or provided with the device may be consulted to refine the correction.
To Determine Longitude
To determine longitude by day, the sundial is configured for time and used to find longitude. Set the zero degree mark on the angle scale 110 to align with the present time at zero longitude (Greenwich Mean Time, or Universal Time), preferably not standard time, but solar time at zero longitude.
From the northern hemisphere face south and hold the instrument in front of you with the rotation axis in a vertical north-south plane. Place the analemma in the analemma holder with the face containing today's date towards the center of the bracelet. The equatorial line 606 of the analemma 600 should be flush with the edge 100 or 200 of the instrument. Now, while maintaining the instrument's rotation axis 806 in the vertical north south plane, tilt the top of the instrument toward or away from you until the shadow of the gnomon 106 a or 106 c located on the same side as the equatorial line falls on today's date on the analemma. (i.e., use the gnomon 106 a or 106 c corresponding to the analemma side 602 or 604 being used) The instrument may be rotated about the axis and the axis may be tilted up or down to achieve the gnomon shadow alignment, but the axis must remain in the north-south plane. Once the gnomon shadow is aligned with the analemma at today's date, the bubble indicator 118 of the bubble embodiment will indicate the longitude. The pearl indicator 118 of the pearl embodiment will be 180 degrees on the angle scale or 12 hours on the hour scale from the correct longitude.
To find longitude at night, place the noon gnomon 106 c of the south face 200 at today's date on the calendar scale 202 . Hold the instrument like a picture frame in front of you while facing north. Center the North Star in the middle of the instrument and rotate the instrument, while keeping the inner ring and outer ring fixed relative to one another, until the blue dot at March 3 on the calendar scale is on an imaginary line between the North Star and Dubhe. Dubhe is the star on the lip of the big dipper (Ursa Major). The bubble or pearl will indicate solar time. Now set the zero degree mark to Greenwich Mean Time and read the longitude at the solar time just determined.
Since the North Star is about ¾ degree from true north in the direction of the little dipper, a slight correction in latitude may be made by observing the angle and direction of this offset. The cosine table inscribed on the device or provided with the device may be consulted to refine the correction.
Time Conversion Between Different Time Zones
As an additional benefit to travelers, or those communicating internationally, the device can also be used to quickly determine the time in another time zone. Travelers often need to call home and wish to call at a convenient time both at the travel location and the home location. The time at home can be found by setting the time scale equal to the current time at the angle scale value equal to the present longitude. The time at home can be read as the time at the home longitude.
Variations
Note that in one configuration having only sundial functionality, the device may comprise a single ring with one gnomon, the 24 hour time scale, and the analemma ticket. Such configuration may be observed in FIG. 1 and FIG. 2 by fixedly attaching the inner and outer rings together. In another configuration, the angle scale may be added to the single ring configuration. In still another variation, two gnomons 106 a and 106 c may be used with the single ring and the analemma ticket may be shortened to half size, each half being used with one of the respective gnomon 106 a or 106 c . These and other subcombinatons of the full device may be found useful in accordance with the teachings herein.
One of ordinary skill in the art may vary the design based on the teachings herein. Such variations include but are not limited to interchanging the inner and outer ring functions, repositioning the scales, alternate scale labels, variations in diameter or thickness, different color schemes, and different materials used for constructing the invention.
CONCLUSION
While various embodiments of the present invention have been described above, it should be understood that they have been presented by way of example only, and not limitation. Thus, the breadth and scope of the present invention should not be limited by any of the above-described exemplary embodiments, but should be defined only in accordance with the following claims and their equivalents.
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A celestial navigation device. A full-featured embodiment is useful as a sundial and planisphere and for measuring, among other things, latitude, longitude, and for time to angle conversions. The device may have one or more rings and is based on a transparent circular tube having a gravity indicator, typically a ball or bubble, in the circular tube, which locates the lowest or highest point in the tube to indicate time or angle measurements against a corresponding scale. The device may have a 24-hour time scale, a calendar scale, and/or an angle scale. One embodiment includes a split analemma with separate north and south portions. Each analemma portion is used with a corresponding gnomon of a pair of gnomons, each on opposite sides of the tubular ring. A two-ring embodiment has an inner ring and outer ring rotatably slidable relative to one another. Two additional gnomons and star position marks may be provided for star sighting observations. The device has a hollow center and may be worn as a bracelet and may be constructed with precious metals and/or gems to enhance the value of the bracelet aspect.
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RELATED APPLICATIONS
[0001] This application claims priority of U.S. Provisional Patent Application No. 61/055,848, filed May 23, 2008 and incorporated herein by reference in its entirety.
INCORPORATION-BY-REFERENCE OF SEQUENCE LISTING
[0002] The Sequence Listing, which is a part of the present disclosure, includes a text file “CRC_ST25.txt,” generated by U.S. Patent & Trademark Office Patent In Version 3.5 software, comprising nucleotide sequences of the present invention. This .txt file has been filed electronically herewith and is incorporated herein by reference in its entirety.
BACKGROUND OF THE INVENTION
[0003] 1. Field of the Invention
[0004] The present invention relates generally to a novel microorganism strain, Salmonella typhimurium CRC2631, and it use as a cancer therapeutic.
[0005] 2. Description of the Prior Art
[0006] The term ‘cancer’ refers generally to a condition in which cells in an organism undergo unchecked growth, tending toward limitless expansion and creation of a tumor. Cancer can originate anywhere in the human body. Cancers that arise from cells covering internal and external body surfaces are referred to as ‘carcinomas,’ while those developing from cells comprising the body's supportive tissues (such as fat, cartilage, bone, and the like) are called ‘sarcomas.’ Other categories of cancers include lymphomas and leukemias.
[0007] The unregulated growth of cancer cells is typically due to a mutation in the DNA of the cell, such as, for example, in genes controlling cell growth (e.g. the transformation of proto-oncogenes into oncogenes). In early stages, such mutations are not noticeable, and a cancer is typically discovered only after it has grown severe enough to produce symptoms in the patient. Early screening techniques can detect cancers prior to the onset of noticeable symptoms in the patient. Breast cancer, for example, is detectable in early stages by the use of mammography. Testing PSA levels in males, coupled with direct rectal exams, can allow a physician to detect early stages of prostate cancer. Early detection of a cancer significantly increases the likelihood of successful treatment of the patient.
[0008] A variety of treatment options exist for the cancer patient. For a male suffering from prostate cancer, for example, hormone-ablative therapy is often effective in treating the early stages of the disease. If the cancer progresses to an androgen-independent stage, other chemotherapies, such as the use of the compound taxol, are indicated. Patients can, however, develop resistance to chemotherapeutic agents such as taxol, and many chemotherapeutic agents are highly toxic to the body. Thus, alternative therapies are desired.
[0009] Salmonella is a genus of gram-negative, rod-shaped enterobacteria. The genus contains over 2,000 sero-species and is one of the most important pathogens in the Enterobacteriaceae family. They are facultative anaerobes, non-spore forming, and are usually motile, having peritrichous flagella. The organisms use citrate as a sole carbon source and typically ferment glucose, but not sucrose or lactose.
[0010] Taxonomically, all Salmonella fall into two species: S. enterica , and S. bongori , with six subspecies present. Popular species names, based largely on sero-typing, are commonly used. Salmonella are often referred to by genus and serovar, such as S. typhimurium , rather than by an extended nomenclature such as S. enterica subspecies enterica serovar typhimurium . For purposes of this document, the name S. typhimurium will be used to refer to S. enterica subspecies enterica serovar typhimurium.
[0011] S. typhimurium is among the more common of the Salmonella serovars . The organism has a circular chromosome of approximately 4,857 kilobases (kb). It is known to cause salmonellosis in humans with varying degrees of severity. In some cases hospitalization is required. Clinical isolation of S. typhimurium is typically performed using MacConkey, XLD, XLT, DCA, or Önöz agars. Preliminary isolation generally requires a selective medium because of the presence of normal intestinal flora in the sample.
[0012] Salmonella-based therapies have been described with respect to prostate and breast cancers. Salmonella typhimurium strains, for example, have been found to target and destroy breast cancer and prostate cancer cells both in vitro and in animal models. S. typhimurium strain VNP20009, a Salmonella derived from strain ATCC14028, has been used in Phase I clinical trials for treatment of human cancers, but was found to have unacceptable levels of toxicity and was therefore unacceptable for use as a therapeutic organism.
[0013] What is needed, then, is a strain of S. typhimurium having reduced or no toxicity while retaining the ability to target and destroy cancer cells.
SUMMARY OF THE INVENTION
[0014] The present invention provides novel strains of the bacterium Salmonella typhimurium for use as a cancer therapeutic.
[0015] One aspect of the present invention provides a biologically pure isolate of the genus Salmonella having a disruption of at least one gene selected from the group consisting of aroA, rfaH, and thyA.
[0016] Another aspect of the present invention provides a biologically pure isolate of the genus Salmonella having a disruption of each of the genes aroA, rfaH, and thyA.
[0017] Another aspect of the present invention provides a biologically pure isolate of Salmonella typhimurium strain CRC2631.
[0018] Still another aspect of the present invention provides a biologically pure isolate of Salmonella typhimurium strain CRC2636.
[0019] Another aspect of the invention provides a method of treating cancer, the method including the step of administering to a subject a therapeutically effective amount of Salmonella having a disruption of at least one gene selected from the group consisting of aroA, rfaH, and thyA.
[0020] In another aspect of the present invention, the method of treating cancer includes administering to a subject a therapeutically effective amount of Salmonella having a disruption of each of the genes aroA, rfaH, and thyA.
[0021] In still another aspect of the present invention, the method of treating cancer includes administering to a subject a therapeutically effective amount of Salmonella typhimurium strain CRC2631.
[0022] In still another aspect of the present invention, the method of treating cancer includes administering to a subject a therapeutically effective amount of Salmonella typhimurium strain CRC2636.
[0023] In another aspect of the present invention, the subject being treated by the present methods is a human. In another aspect of the present invention, the cancer being treated by the present methods is prostate cancer.
[0024] In still another aspect of the invention, a method for treating cancer is provided, the method including the step of administering to a subject in need thereof a therapeutic agent bound to Salmonella having a disruption of at least one gene selected from the group consisting of aroA, rfaH, and thyA.
[0025] In another aspect of the invention, a method for treating cancer is provided, the method including the step of administering to a subject in need thereof a therapeutic agent bound to Salmonella having a disruption of each of aroA, rfaH, and thyA.
[0026] In still another aspect of the invention, a method for treating cancer is provided, the method including the step of administering to a subject in need thereof a therapeutic agent bound to a molecule capable of binding mannose-linked GlcNAcβ1-4GlcNAcβ-N/Gly, mannose-linked Manα1-6Manα-Sp9, or transferring-lined glycans.
BRIEF DESCRIPTION OF THE DRAWINGS
[0027] FIG. 1 : Fluorescent CRC2636 binds preferentially to PC-3M cells but not to normal RWPE-1 cells.
[0028] FIG. 2 : CRC2631 more effectively invades PC-3M carcinoma cells over time.
[0029] FIG. 3 : Archived S. typhimurium preferentially targets PC-3M prostate carcinoma cells but do not target normal RWPE-1 prostate cells.
[0030] FIG. 4 : Histological analysis of S. typhimurium CRC2636 specific targeting of primary prostate tumor.
[0031] FIG. 5 : CRC2631 S. typhimurium binds specifically to glycans present on carcinoma cells and viral proteins.
[0032] FIG. 6 : DNA-DNA microarray of labeled CRC1674 and CRC2631 sequences on an LT2 gene microarray.
DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS
Definitions
[0033] “Agent” or “Therapeutic Agent:” As used herein, the terms “agent” and “therapeutic agent” refer to any natural or synthesized composition that when administered to a subject relieves the subject of disease or improves health. Wherein the disease being treated is cancer. The “agent” or “therapeutic agent” may be a pro-drug, further defined below.
[0034] “Bind, Binds, or Interacts With:” As used herein, “bind,” “binds,” or “interacts with” means that one molecule recognizes and adheres to a particular second molecule in a sample, in vitro or in vivo, but does not substantially recognize or adhere to other structurally-unrelated molecules in the sample. Generally, a first molecule that “specifically binds” a second molecule has a binding affinity of greater than about 10 5 or 10 6 moles/liter for that second molecule.
[0035] “Gene:” As used herein, the term “gene” means a nucleic acid molecule that codes for a particular protein, or in certain cases, a functional or structural RNA molecule.
[0036] “Labeled:” The term “labeled,” with regard to a probe or antibody, is intended to encompass direct labeling of the probe or antibody by coupling (i.e., physically linking) a detectable substance to the probe or antibody.
[0037] “Native:” When referring to a nucleic acid molecule or polypeptide, the term “native” refers to a naturally-occurring (e.g., a “wild-type”) nucleic acid or polypeptide.
[0038] “Nucleic Acid or Nucleic Acid Molecule:” As used herein, the term “nucleic acid” or “nucleic acid molecule” means a chain of two or more nucleotides such as RNA (ribonucleic acid) and DNA (deoxyribonucleic acid). A “purified” nucleic acid molecule is one that is substantially separated from other nucleic acid sequences in a cell or organism in which the nucleic acid naturally occurs (e.g., 30%, 40%, 50%, 60%, 70%, 80%, 90%, 95%, 96%, 97%, 98%, 99%, 100% free of contaminants). The term includes, e.g., a recombinant nucleic acid molecule incorporated into a vector, a plasmid, a virus, or a genome of a prokaryote or eukaryote. Examples of purified nucleic acids include cDNAs, fragments of genomic nucleic acids, nucleic acids produced polymerase chain reaction (PCR), nucleic acids formed by restriction enzyme treatment of genomic nucleic acids, recombinant nucleic acids, and chemically synthesized nucleic acid molecules. A “recombinant” nucleic acid molecule is one made by an artificial combination of two otherwise separated segments of sequence, e.g., by chemical synthesis or by the manipulation of isolated segments of nucleic acids by genetic engineering techniques.
[0039] “Pharmaceutically Acceptable:” As used herein, the term “pharmaceutically acceptable” means approved by a regulatory agency of the Federal or a state government or listed in the U.S. Pharmacopeia or other generally recognized pharmacopeia for use in animals, and more particularly in humans.
[0040] “Pharmaceutically Acceptable Carrier:” As used herein, the term “pharmaceutically acceptable carrier” refers to a diluent, adjuvant, excipient, or vehicle with which a composition is administered. Such carriers can be sterile liquids, such as water and oils, including those of petroleum, animal, vegetable or synthetic origin, such as peanut oil, soybean oil, mineral oil, sesame oil and the like, polyethylene glycols, glycerine, propylene glycol or other synthetic solvents. Water is a preferred carrier when a composition is administered intravenously. Saline solutions and aqueous dextrose and glycerol solutions can also be employed as liquid carriers, particularly for injectable solutions. Suitable excipients include starch, glucose, lactose, sucrose, gelatin, malt, rice, flour, chalk, silica gel, sodium stearate, glycerol monostearate, talc, sodium chloride, dried skim milk, glycerol, propylene, glycol, water, ethanol and the like. A composition, if desired, can also contain minor amounts of wetting or emulsifying agents, or pH buffering agents such as acetates, citrates or phosphates. Antibacterial agents such as benzyl alcohol or methyl parabens; antioxidants such as ascorbic acid or sodium bisulfite; chelating agents such as ethylenediaminetetraacetic acid; and agents for the adjustment of tonicity such as sodium chloride or dextrose may also be a carrier.
[0041] “Pro-drug:” As used herein, the term “pro-drug” refers to any composition which releases an active drug in vivo when such a composition is administered to a mammalian subject. Pro-drugs can be prepared, for example, by functional group modification of a parent drug. The functional group may be cleaved in vivo to release the active parent drug compound. Pro-drugs include, for example, compounds in which a group that may be cleaved in vivo is attached to a hydroxy, amino or carboxyl group in the active drug. Examples of pro-drugs include, but are not limited to esters (e.g., acetate, methyl, ethyl, formate, and benzoate derivatives), carbamates, amides and ethers. Methods for synthesizing such pro-drugs are known to those of skill in the art.
[0042] “Subject:” As used herein, the terms “subject” and “subjects” refer to any mammal, including a human mammal.
[0043] Non-human animals subjects may include, but are not limited to, mammals such as primates, mice, pigs, cows, cats, goats, rabbits, rats, guinea pigs, hamsters, horses, sheep, dogs, and the like. Such animals may be companion animals, as in the case of dogs and cats, for example, or may be trained animals including therapy animals such as a therapy dog. Also included are service animals, such as dogs that assist persons who are in need of assistance due to loss or impairment of sight, hearing, or other senses. Further, non-human subjects may include working animals such as dogs or other animals trained for security or rescue work. Also included are animals trained or maintained for procreation or entertainment purposes, including purebred animal breeds, racehorses, or workhorses. Animals that are genetically-engineered are likewise included, regardless of the purposes of the genetic engineering, as are rare or exotic animals, including zoo animals and wild animals.
[0044] “Therapeutically Effective Amount:” As used herein, the term “therapeutically effective amount” refers to those amounts that, when administered to a particular subject in view of the nature and severity of that subject's disease or condition will have a desired therapeutic effect, e.g. an amount that will cure, prevent, inhibit, or at least partially arrest or partially prevent a target disease or condition.
[0045] “G,” “C,” “A”, “T” and “U” (irrespective of whether written in capital or small letters) each generally stand for a nucleotide that contains guanine, cytosine, adenine, thymine, and uracil as a base, respectively. However, it will be understood that the term “ribonucleotide” or “nucleotide” can also refer to a modified nucleotide, as further detailed below, or a surrogate replacement moiety. The skilled person is well aware that guanine, cytosine, adenine, thymine, and uracil may be replaced by other moieties without substantially altering the base pairing properties of an oligonucleotide comprising a nucleotide bearing such replacement moiety. For example, without limitation, a nucleotide comprising inosine as its base may base pair with nucleotides containing adenine, cytosine, or uracil. Hence, nucleotides containing uracil, guanine, or adenine may be replaced in the nucleotide sequences of the invention by a nucleotide containing, for example, inosine.
[0046] In accordance with the present invention, there may be employed conventional techniques of molecular biology and microbiology. These techniques are within the skill in the art and are explained fully in the literature. See, for example, Sambrook, Fritsch & Maniatis, M OLECULAR C LONING : A LABORATORY M ANUAL , Third Edition (2001), Cold Spring Harbor Laboratory Press, Cold Spring Harbor, N.Y.
[0047] The present invention is directed to a novel microorganism strain designated Salmonella typhimurium CRC2631 ( S. enterica subspecies enterica serovar typhimurium ), and its use as a cancer therapeutic. The strain has been derived from a Salmonella typhimurium LT2 hisD2550 mutant, CRC1674, as described below. The toxicity of the CRC2631 strain was attenuated by long-term archival storage as well as direct manipulation of the microorganism's genome.
[0048] Archival Storage of Salmonella typhimurium CRC1674
[0049] In April of 1967, an inoculum of S. typhimurium strain CRC1674 was placed in a sealed glass stab jar containing solid Luria-Bertani (LB) agar. A plug of this archival agar stab was extracted and grown in LB broth on Jan. 19, 1999, meaning that the S. typhimurium strain at issue was stored under archival conditions for approximately 32 years. A number of mutations in the microorganism were observed after the period of archival storage, and these mutations are described in the literature and known in the art. After storage, CRC1674 had developed, for example, a G168T mutation of rpoS (RNA-polymerase sigma factor). Further, the hisD2550 auxotrophic mutation in the parent strain was partially suppressed. Ten genes located in the membrane region of the microorganism were also deleted, and one-hundred eighty-two genes showed substantial changes (amounting to 4.4% of the genome).
[0050] Production of Strain CRC2631 from Archival CRC1674
[0051] Archival strain CRC1674 retains a level of toxicity that renders it undesirable for use in human cancer therapies. In order to reduce this toxicity to acceptable levels, the present invention was developed, and the process of that development is now described.
[0052] In order to reduce the toxicity of CRC1674, and thus produce the present invention, CRC2631, targeted gene disruptions were performed with respect to three S. typhimurium genes: aroA, rfaH, and thyA. The method of disruption used with respect to each gene is detailed below, although it is contemplated that any suitable method of gene disruption may be used without departing from the spirit or scope of the present invention. For purposes of this document, the term ‘disruption’ may include, but is not limited to, deletion of the gene in question.
[0053] Disruption of aroA
[0054] The aroA gene of S. typhimurium is involved in the synthetic pathways relating to aromatic amino acids as well as folic acid. Thus, disruption of the aroA gene renders the bacterium auxotrophic for aromatic amino acids. Disruption of aroA was accomplished by use of the high-transducing phage P22HT. P22HT transduction was used to insert a Tn10 cassette, a contiguous block of genes derived from the bacterial transposon Tn10, into the aroA gene, thereby disrupting the functionality thereof. The Tn10 cassette is known in the art, as it is use in disrupting bacterial genes.
[0055] Disruption of rfaH
[0056] The rfaH gene of S. typhimurium is involved in lipopolysaccharide (LPS) synthesis. The gene product is a transcriptional promoter that stimulates the production of LPS biosynthesis gene products. Disruption of rfaH resulted in shorter and less lipopolysaccharide production by the bacterium. The gene was disrupted via the lambda red recombination protocol, which is known in the art and provides for efficient recombination between homologous sequences as short as forty base pairs. The use of the lambda red recombination protocol in this instance resulted in deletion of the gene.
[0057] The primers used for constructing the Lambda Red recombination deletions in the rfaH gene are provided in Table 1, below, as SEQ ID NO 3 and SEQ ID NO 4. Sequences are provided in 5′ to 3′ orientation.
[0000]
TABLE 1
Primers used for constructing Lambda Red
recombination deletions in rfaH
SEQ ID NO 3: CTA AAT CTT GCG AAA ACC GGT GTT TTT
TAC GCT CTG CTT GTG TAG GCT GGA GCT GCT TC
SEQ ID NO 4: ATG CAA TCC TGG TAT TTA CTG TAC TGC
AAA CGC GGG CAA CAT ATG AAT ATC CTC CTT AG
[0058] Disruption of thyA
[0059] The thyA gene of S. typhimurium encodes thymidylate synthase A, an enzyme involved in the production of nucleic acid precursors. The disruption of thyA was also accomplished via the lambda red recombination protocol and resulted in deletion of the gene.
[0060] The primers used for constructing the Lambda Red recombination deletions in the thyA gene are provided in Table 2, below, as SEQ ID NO 1 and SEQ ID NO 2. Sequences are provided in 5′ to 3′ orientation.
[0000]
TABLE 2
Primers used for constructing Lambda Red
recombination deletions in thyA
SEQ ID NO 1: TTA GAT AGC GAC CGG CGC TTT AAT ACC
GGG GTG CGG ATC GTG TAG GCT GGA GCT GCT TC
SEQ ID NO 2: ATG AAA CAG TAT TTA GAA CTG ATG CAA
AAA GTG CTG GAT CAT ATG AAT ATC CTC CTT AG
Example 1
CRC1674 Retains the Ability to Target Prostate and Breast Cancer Cells In Vivo
[0061] CRC1674, one of the archival LT2 strains of S. typhimurium , retains the ability to target prostate and breast cancer cells in vivo, as shown in FIG. 3 . The top panel of FIG. 3 shows co-incubation for one hour of live RWPE-1 cells and CRC1674. Both RWPE-1 cells and CRC1674 cells were fluorescently labeled. As shown in the figure, CRC1674 showed no affinity for RWPE-1 cells. The photographs provided in the figure were obtained using confocal microscopy of two different focal planes.
[0062] The bottom panel of FIG. 3 compares the targeting of fixed PC-3M prostate cancer cells by S. typhimurium strains CRC1674 and VNP20009. VNP20009 is a strain of S. typhimurium already known to shrink solid tumors. As shown in the figure, CRC1674 more effectively targeted PC-3M than did VNP20009. A greater proportion of CRC1674 bacteria are seen attached to the PC-3M cells as compared to VNP20009, which is present in equal proportion in both cell and non-cell areas.
Example 2
CRC2631 Preferentially Invades PC-3M Cancer Cells
[0063] S. typhimurium strain CRC2631 was observed to attach to RWPE-1 normal prostate cells at low levels. Gentamycin exclusion assays were performed in order to determine the rate of normal RWPE-1 cell invasion versus cancer PC-3M cell invasion. An initial 2 mL of media containing about 5×10 6 to 1×10 7 colony-forming units (CFU) of S. typhimurium CRC2631 in co-incubation with PC-3M and RWPE-1 cells was removed after 0.5 hours of incubation and replaced with appropriate cell culture media containing 40 μg/mL gentamycin. This killed all non-invaded Salmonella.
[0064] Approximately 1% to 10% of the initial CRC2631 load was able to successfully invade PC-3M prostate cancer cells after a thirty-minute incubation. Less than about 0.1% to 1% of the initial CRC2631 load was able to invade the normal RWPE-1 cells over the same time period. After twenty-four hours both strains CRC1674 and CRC2631 exhibited an increase in PC-3M cells, but not in RWPE-1 cells, indicating that these strains were successfully growing in the prostate cancer cell line, but were not able to persist as effectively in the normal RWPE-1 cell line.
Example 3
Fluorescent CRC2636 Binds Preferentially to PC-3M Cells but not to Normal RWPE-1 Cells
[0065] Strain CRC2631 was provided with a plasmid expressing a red fluorescent protein (pRST-mCherry) in order to produce fluorescent strain CRC2636. This strain was then co-incubated with RWPE-1 cells in one instance, and with PC-3M cells in a second instance. FIG. 1 a shows preferential binding of CRC2626 to PC-3M after twenty minute incubation period. FIG. 1 b , top panel, shows that CRC2636 did not target normal RPWE-1 cells after one hour of incubation. Conversely, FIG. 1 b , bottom panel, shows that CRC2636 did in fact target PC-3M carcinoma cells after incubation for the same amount of time. As can be seen in the figure, a larger number of CRC2636 (greater than one-hundred) cells are bound to sub-confluent PC-3M cells as compared to CRC2636 cells bound to fully confluent RPWE-1 cells (approximately eight).
Example 4
CRC2631 More Effectively Invades PC-3M Carcinoma Cells Over Time
[0066] Bacterial strains CRC1674 and CRC2631 were incubated with PC-3M or RPWE-1 cells for one-half hour or for two hours. Bacteria outside of cells were killed with gentamycin, and viable bacteria were recovered from within cells. FIG. 2 depicts the results, showing the number of Salmonella that invaded the two cell lines at either one-half or two hours. As can be seen from the figure, CRC1674 and CRC2631 cells preferentially invaded PC-3M cancer cells as compared to RWPE-1 normal cells. The ratio between the two varied from 250:1 to 1000:1.
Example 5
Histological Analysis of S. typhimurium CRC2636 Specific Targeting of Primary Prostate Tumor
[0067] CRC2636 was introduced into TRAMP mice via intra-peritoneal injection. Three days after injection, the mice were killed and primary prostate tumor and liver samples were taken and prepared for histological examination. Transmission and fluorescent photomicrographs of the same field were taken of both liver and primary prostate tumor tissue. The fluorescent field was then overlaid with the transmission photograph. The results are shown in FIG. 4 . As can be seen from the figure, in vivo the fluorescent CDC2636 strain preferentially targets primary mouse prostate tumors.
Example 6
CRC2631 S. typhimurium Binds Specifically to Glycans Present on Carcinoma Cells and Viral Proteins
[0068] Two-hundred and eighty-five eukaryotic cell glycans were extracted, purified, and spotted onto glass slides. The slides were then incubated with FITC-labeled bacteria strains LT2, CRC1674, CRC2631, and VNP20009. Binding was detected as relative fluorescence units. Six replicates were performed for each of the glycans, with the top and bottom values eliminated from each replicate. Relative fluorescence was calculated using the middle values. The results are shown in FIG. 5 , in which bacterial strains are connected by lines to the glycans to which they bound, with intensity of binding indicated by the lightness or darkness of the lines. Glycans bound with high intensity by CRC2631 are indicated with large red circles.
[0069] Only CRC2631 and VNP20009 showed high intensity binding to glycans. CRC2631 bound to mannose-linked GlcNAcβ1-4GlcNAcβ-N/Gly terminal disaccharides, Manα1-3(Manα1-6)Manα-Sp9, and transferrin-linked glycans. The range of glycans to which CRC2631 binds with high intensity is reduced as compared to VNP20009, which suggests that CRC2631 binds with higher specificity to carcinoma-associated antigens. This finding can provide the basis for therapies directed to cells expressing these carcinoma-associated antigens. Expression of GlcNAcβ1-4GlcNAcβ-N/Gly terminal disaccharides is upregulated on various carcinoma cells. Carcinoma cells also express transferrin, which may play a role in carcinoma cell survival. High-mannose carbohydrates are found on viral proteins and serve as a ligand for DC-SIGN (Dendritic Cell-Specific Intercellular adhesion molecule-3-Grabbing Non-integrin).
Example 7
Microarray Characterization of CRC1674 and CRC2631 as Compared to LT2
[0070] CRC1674 (the parent strain of CRC2631, exhibiting unacceptable toxicity), CRC2631, and LT2 were each genetically profiled to determine the differences between the three strains. Because CRC1674 was derived from LT2, and CRC2631, the strain of the present invention, was developed in an attempt to create a therapeutic strain, it was desirable to determine the extent of the differences between the three. Both the CRC1674 and CRC2631 strains were profiled by generating Cy3-dCTP-labeled PCR products using random primers, then comparing their hybridization on multi-serovar S. enterica microarrays with the hybridization of a sequence LT2 isolate.
[0071] The majority of the CRC1674 cells were observed to have lost or have substantial changes in ten genes as compared to the sequences LT2 strain. The genes lost include the transcriptional regulator KdgR, a member of the IciR transcriptional regulator family. KdgR normally regulates pectin degradation in Erwinia chrysanthemia and is conserved in the Enterobacteriaceae family. Other lost or modified genes included rrmA, which encodes a rRNA guanine-N1-methyltransferase protein, a penicillin-binding protein, and six uncharacterized proteins with putative functions. Higher microarray signals in the query strain compared to LT2 indicated that the Gifsy-1 and Gifsy-2 phage genomes were amplified at positions STM1005-STM10056 and STM2584-STM2636. this indicates the existence of more copies of the Gifsy phase in CRC1674, possibly due to phage propagation or duplication.
[0072] The CRC2631 strain retained the STM1834-1843 deletions of CRC1674, and results confirmed the engineered loss of thyA and rfaH using the Red-mediated recombination protocol previously referenced. Gene amplifications in CRC2631 were distinct from those of CRC1674. In CRC2631, only the gene region from STM943-STM1013 and the Gifsy-1 phage gene STM2630 were amplified.
[0073] FIG. 6 provides the results of a DNA-DNA microarray of labeled CRC1674 and CRC2631 on an LT2 gene microarray. Gene deletions and amplifications were detected by comparing the relative fluorescence of labeled S. typhimurium LT2, CRC1674, and CRC2631 chromosomal DNA. Signals greater than 4600 represent genes in the pLST Salmonella plasmid.
Example 8
Injection Procedure in Tumor-Bearing Mammalian Models
[0074] The following procedure was generally used for injection of the therapeutic strain CRC2631 of the present invention into mice for monitoring the efficacy and toxicity of the present invention.
[0075] Overnight cultures of CRC2631 containing the pRTSmCherry plasmid were grown in 100 mL of LB broth with 200 μg/mL of thymine. The culture was centrifuged at 2700×g, the supernatant carefully removed, and the pellet of cells resuspended with gently shaking in 2 mL of 1×PBS. 1 mL of the cells was then diluted in PBS to a final optical density of 0.200, which represents approximately 1.0×10 7 CRC2631 bacteria/mL. Each of four mice were injected interperitoneally with 1.0 mL of each serial dilution concentration of CRC2631. The mice were monitored for toxic symptoms hourly for the first twelve hours, and then three times daily afterward.
Example 9
Toxicity Studies of CRC2631 in TRAMP Mice
[0076] Male TRAMP mice between the ages of eight and twelve weeks were injected interperitoneally (IP) with 0.9 mL of overnight CRC2631 cultures washed in PBS and diluted serially to determine the minimum toxic dose in the mammalian mouse model. The IP injections were performed according to the following procedure:
[0077] To prepare an overnight culture for injection, frozen stock was streaked onto LB agar with 200 μg/mL thymine. The plates were incubated overnight at 37 degrees C. A 25 mL culture of CRC2631 in LB broth having 200 μg/mL thymine added thereto was started from a single isolated colony from one of the agar plates. The culture was incubated in a shaking 37° C. water bath overnight. The following day, the 25 mL culture was spun down at 4000 rpm for ten minutes in a 50 mL conical tube using a swing bucket rotor. The supernatant was discarded and the pellet of cells resuspended in 25 mL 1×PBS. The optical density of the therapeutic strain was normalized to Abs 600=0.200 and the culture was transported to the facility housing the TRAMP mice.
[0078] For each mouse to be injected, 0.9 mL of the Salmonella test culture was drawn into a sterile hypodermic syringe. The injection site on each mouse was sterilized with 70% ethanol and the interperitoneal injection was made. The mice were checked at four, eight, and twelve hours post-injection.
[0079] Male TRAMP mice were selected because of their tendency to spontaneously develop primary and secondary prostate cancer cells after twenty weeks of age. The mice tolerated single injections of up to about 2×10 8 CFU of CRC2636 bacteria. When the therapeutic bacteria were injected into mice having prostate tumors, the tumors were found to have Salmonella loads two-fold to one-hundred-fold higher than the liver after two to three days.
Example 10
Tolerance of S. typhimurium strain CRC2636 Injected into TRAMP Mice with and without Primary Tumors
[0080] Table 3, below, provides the results of injection of strain CRC2636 into TRAMP mice both with and without primary tumors. Injections were performed intraperitoneally with strain CRC2636 cells suspended in PBS. The column labeled ‘deaths’ refers to mice that either died or were rapidly crashing (i.e. dying) before sacrifice. ‘Survival’ is an indication of how long, in days, mice survived before sacrifice. Non-tumor bearing mice were co-injected with tumor-bearing mice in order to compare survival rates. None of these mice suffered ill effects from any of the CRC2636 injections. Mice living for 2-3 days were sacrificed intentionally to determine the location and number of Salmonella in the mouse model (the prostate tumor, liver, and spleen).
[0000]
TABLE 3
Deaths
Mean
Median
Range of
TRAMP
Number
CRC2636 Dose
(total number
Survival
Survival
Survival
Mice
of Mice
(CFU/IP Injection)
treated)
(Days)
(Days)
(Days)
Tumor-
22
9.3e 4 to 3.3e 7
9/22
2.2
2
1 to 14
bearing,
injected
Non-tumor
4
5.9e 6 to 3.3e 7
0(4)
2.8
3
2 to 3
bearing,
injected
Non-tumor
4
1.18e 8
1(4)
398
525+
18 to 525+
bearing,
injected
Non-tumor
4
1.24e 7
0(4)
525+
525+
525+
bearing,
injected
FURTHER ASPECTS OF THE INVENTION
[0081] One of skill in the art will recognize further aspects of the present invention based on the disclosure provided herein. For example, it is contemplated that the Salmonella of the present invention could be associated with a therapeutic agent effective against cancer and the Salmonella used to target cancer cells for delivery of the therapeutic agent. It is further contemplated that a therapeutic agent effective against cancer could be bound to a molecule targeting the glycans described above as specifically bound by S. typhimurium strain CRC2631, thereby delivering the therapeutic agent to cells having those specific glycans expressed on a membrane thereof.
[0082] The detailed description set forth above is provided to aid those skilled in the art in practicing the present invention. The invention described and claimed herein, however, is not to be limited in scope by the specific embodiments disclosed because these embodiments are intended to be illustrative of several aspects of the invention. Any equivalent embodiments are intended to be within the scope of the present invention. Various modifications of the invention that do not depart from the spirit or scope of the present invention, in addition to those shown and described herein, will become apparent to those skilled in the art from the foregoing description. Such modifications are also intended to fall within the scope of the appended claims.
[0083] Having thus described the preferred embodiment of the invention, what is claimed as new and desired to be protected by Letters Patent includes the following:
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The present invention provides a biologically pure isolate of the genus Salmonella having a disruption of at least one gene selected from the group consisting of aroA, rfaH, and thyA, as well as a method of treating cancer including the step of administering such a Salmonella to a subject in need thereof.
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PRIORITY CLAIM
The present application claims the benefit of French patent application Ser. No. 05/54130, filed Dec. 29, 2005, which application is incorporated herein by reference in its entirety.
1. Technical Field
Embodiments of the present invention generally relate to liquid crystal display screens (LCD) and, more specifically, to circuits for controlling such screens.
2. Discussion of the Related Art
FIG. 1 partially and very schematically shows a pixel 1 of a monochrome LCD screen or a sub-pixel of a color LCD screen. Electrically, each pixel 1 is formed of a control switch M (typically, a MOS transistor) and of a capacitor C 1 , as a memory cell. A first conduction terminal of switch M is connected to a column conductor Col, common to all the switches of the display panel column. The other conduction terminal is connected to a first electrode of capacitor C 1 of the pixel, having its second electrode connected to ground, the dielectric of capacitor C 1 being formed of the liquid crystal used for the display. The gates of switches M are connected, in rows, to line conductors Row. The presence of switch M generates a capacitive element C between its gate and its source, and thus between line Row and the first electrode of capacitance C 1 of cell 1 . Columns conductors Col are controlled by a column driver circuit 2 (CDRIVER) generally setting the luminance reference values while row conductors Row are controlled in scan mode by a row driver circuit 3 (GDRIVER).
For a color screen, each cell 1 forms a sub-pixel and the color is provided by a corresponding chromatic filter (RGB) arranged in front of each sub-pixel.
FIG. 2 partially and schematically shows the equivalent electric diagram of a liquid crystal display panel 10 and of its row control circuit In the example of FIG. 2 , only two columns Col i and Col i+1 have been shown. Similarly, only five rows Row 1 , Row 2 , Row 3 , Row n-1 , and Row n have been shown. The screen integration on a substrate generally made of glass is no longer limited to the cells but also involves the row control circuits. These circuits comprise, for each row, an RS-type flip-flop B 1 , B 2 , B 3 . . . , Bn- 1 , and Bn, the direct Q output of which is used to control a switch K 1 , K 2 , K 3 , Kn- 1 , Kn placed on each row conductor to bring a supply voltage onto it. The S activation input of first flip-flop B 1 receives a scan start signal Start. The S activation input of flip-flop B 2 is connected to line Row 1 , downstream of switch K 1 with respect to the supply source. The S activation input of flip-flop B 3 is connected to line Row 2 , downstream of switch K 2 , etc. until the S activation input of the last flip-flop Bn connected to line Row n-1 . The R reset inputs of the flip-flops are respectively connected to the conductor of the row of next rank, downstream of the corresponding switch K, until the R input of the last flip-flop Bn which is looped back on row Row 1 .
The line powering is generally performed by a line scanning. The rows of odd rank Row 1 , Row 3 , . . . , Row n-1 are interconnected upstream of switches K 1 , K 3 , . . . Kn- 1 to a terminal 32 while the lines of even rank Row 2 , . . . Row n are, upstream of their respective switches, connected to a terminal 33 . Terminals 32 and 33 are respectively connected to the junction points of pairs of switches Q 1 and Q 2 , respectively Q 3 and Q 4 , series-connected between terminals of application of respectively high and low turn-on and turn-off voltages V ON and V OFF .
The scanning is performed by lines, starting, for example, with an odd line by turning on switches Q 1 and Q 4 and by turning off switches Q 2 and Q 3 for both supplying this odd line and forcing the turning-off of the even line of next rank. Signal Start applied on the S activation input of first flip-flop B 1 enables automatic row scanning. The addressing of an even row is performed symmetrically by turning off switches Q 1 and Q 4 and by turning on switches Q 2 and Q 3 . The switching of switches Q 1 to Q 4 is thus performed at the rate of the line scanning under control of a circuit 5 (CTRL).
A problem is that the series associations of elements C and C 1 of all columns of a row are in parallel and have a charge opposite to that of the next row.
To avoid too high a power loss, a charge recovery stage is generally provided, thus enabling, for each column, using the power stored in the pixels to be turned off of the row which has just been addressed to help the turning-on of the pixels of the next line. For this purpose, terminals 32 and 33 are generally connected by an assembly of two diodes in ant-parallel D 1 and D 2 , each in series with a resistor R 1 and R 2 and a switch S 1 and S 2 .
FIG. 3 shows an equivalent simplified electric diagram of FIG. 2 enabling better illustrating the operation of the H bridge formed of switches Q 1 , Q 2 , Q 3 , and Q 4 and the charge transfer circuits formed of switches S 1 , S 2 and of their diodes and resistors in series. The assembly of the cells of an odd line of the panel has been symbolized by a block 35 , a switch Mo, and an equivalent capacitance
Co ( 1 Co = ∑ ( 1 C + 1 C 1 ) ,
the sum comprising all the cells in the odd row). The assembly of the cells of the even rows has been symbolized by a block 36 , a switch Me and an equivalent capacitance
Ce ( 1 Ce = ∑ ( 1 C + 1 C 1 ) ,
the sum comprising all the cells in the even row). For simplification, the flip-flops used for the scanning have not been illustrated in FIG. 3 . These flip-flops are in practice interposed between each terminal 32 and 33 and the odd and even lines of blocks 35 and 36 .
For the turning-on of the pixels of the first odd line, switches Q 1 and Q 4 are turned on, which causes the application of a voltage V ON on terminal 32 and V OFF on terminal 33 . A current can then flow to charge the capacitances of pixels of this first line. At the end of this addressing period, transistors Q 1 and Q 4 are turned off and switch S 1 is turned on for a so-called power recovery or transfer phase, which enables precharging the next line (even) by the discharge of the odd line which has just been addressed. This phase places the first odd and even lines in an intermediary equilibrium voltage. Then, switches Q 2 and Q 3 are turned on to bring the voltage of the even line to level V ON and end the discharge of the first odd line to level V OFF . At the end of the turning-on of the even line, switches Q 2 and Q 3 are turned off and switch S 2 is turned on to enable precharge of the next odd line and thus resume the operation by turning-on of switches Q 1 and Q 4 .
With known LCD screens or panels, losses remain high even with the charge transfer stages. For example, for a screen having its assemblies of even and odd lines respectively exhibiting equivalent 4.7-nF capacitances Ceq=Co=Ce, with a line scanning at a 166-kHz frequency f with a 35-volt turn-on voltage V ON and a −25-volt turn-off voltage V OFF , losses amount to approximately 1.4 watts (f*Ceq(V ON -V OFF ) 2 /2).
Furthermore, with known displays the control of the switches S 1 and S 2 of the charge recovery stages is generally complex, due to the floating voltages of the terminals of these switches.
SUMMARY OF THE INVENTION
Embodiments of the present invention improve the control of flat screens, especially with liquid crystals, with a charge transfer stage to decrease the power losses of such screens.
The control of the switches of charge transfer stages may also be simplified.
One embodiment of the present invention provides a liquid crystal display charge transfer circuit including at least one inductive element connectable between a first and a second common terminal, respectively, to a first and to a second group of lines of the display.
According to an embodiment of the present invention, said terminals are connected to the respective junction points of switches connected, in pairs, in series between third and fourth terminals of application of high and low line supply voltages.
According to an embodiment of the present invention, the circuit comprises two switches respectively in parallel with a diode, these parallel associations being in series between said first and second terminals, and said inductive element being interposed between the two switches.
According to an embodiment of the present invention, each switch has a first conduction terminal connected to the inductive element and its control terminal connected to its second conduction terminal by a parallel association of a resistive element, of a capacitive element, and of a voltage-limiting element, the control terminal of each switch being further respectively connected to the midpoints of series associations of diodes connected between a fifth terminal of provision of a control current and said third terminal of application of the high line supply voltage.
According to an embodiment of the present invention, said control current is provided by a current source connected via a third switch to said fifth terminal.
According to an embodiment of the present invention, said capacitive element comprises the gate-source capacitance of a MOS transistor forming the corresponding switch.
Embodiments of the present invention also provide a circuit for controlling a liquid crystal display.
Embodiments of the present invention include a circuit for controlling a liquid crystal display and may also include such a control circuit in a flat liquid crystal display.
Embodiments of the present invention will be discussed in detail in the following non-limiting description of example embodiments in connection with the accompanying drawings.
BRIEF DESCRIPTION OF THE DRAWINGS
FIG. 1 , previously described, very schematically and partially shows a liquid crystal display to which embodiments of the present invention apply;
FIG. 2 , previously described, shows an equivalent electric diagram of a liquid crystal display and of a conventional line control circuit with a supply and charge transfer stage;
FIG. 3 , previously described, shows a simplified electric diagram of the supply and charge transfer circuit of FIG. 2 ;
FIG. 4 very schematically and partially shows a power supply circuit of a liquid crystal display according to an embodiment of the present invention;
FIGS. 5A , 5 B, 5 C, 5 D, 5 E, 5 F, and 5 G are examples of timing diagrams illustrating the operation of the circuit of FIG. 4 ;
FIG. 6 shows an embodiment of a circuit for controlling the charge transfer switches of the circuit of FIG. 4 ; and
FIG. 7 shows a variation of charge transfer circuit according to an embodiment of the present invention.
DETAILED DESCRIPTION
The following discussion is presented to enable a person skilled in the art to make and use the invention. Various modifications to the embodiments will be readily apparent to those skilled in the art, and the generic principles herein may be applied to other embodiments and applications without departing from the spirit and scope of the present invention. Thus, the present invention is not intended to be limited to the embodiments shown, but is to be accorded the widest scope consistent with the principles and features disclosed herein.
The same elements have been designated with the same reference numerals in the different drawings. For clarity, only those control steps and elements which are necessary to the understanding of embodiments of the present invention have been shown in the drawings and will be described hereafter. In particular, the provision of the different luminance control signals brought by the column control circuits has not been detailed, since embodiments of the present invention involve no necessary modifications of these circuits. The same is true for the line scanning performed by a conventional circuit (for example, of the type described in relation with FIG. 2 ).
A feature of an embodiment of the present invention is to use an inductive element in the charge transfer stage of the display.
FIG. 4 shows an embodiment of the present invention. This drawing shows the equivalent electric diagram of a liquid crystal display in a representation to be compared with that of previously-described FIG. 3 .
The assembly of cells of a line of odd rank is symbolized by a block 35 , a switch Mo, and an equivalent capacitor Co. The assembly of cells of a line of even rank is symbolized by a block 36 , a switch Me, and an equivalent capacitance Ce. As previously described, the line conductors are connected via scan switches (not shown) to common points, respectively 32 for odd lines and 33 for even lines. For simplification, the scan circuit has not been illustrated in FIG. 4 . Points 32 and 33 are connected to the junction points of switches Q 1 and Q 2 and switches Q 3 and Q 4 , respectively, between two terminals of application of respectively high and low supply voltages V ON and V OFF .
According to this embodiment of the present invention, charge transfer stage 38 connecting terminals 32 and 33 to form, with switches Q 1 to Q 4 , an H bridge, comprises two switches S 1 and S 2 in series and between which an inductive element L is interposed, each switch being in parallel with diodes D 1 , D 2 having anodes connected to terminals 33 , and 32 , respectively.
An inductance L made of ferrite may be used to optimize the loss reduction.
FIGS. 5A , 5 B, 5 C, 5 D, 5 E, 5 F, and 5 G are timing diagrams illustrating, in examples of shapes of control signals of switches Q 1 and Q 4 , of switch S 1 , switches Q 2 and Q 3 , of switch S 2 , and in examples of shapes of voltages VCe and VCo across equivalent capacitors Ce and Co of the cells of an even and odd line, respectively, as well as in an example of shape of current I in the charge transfer stage, the operation of the circuit of FIG. 4 .
As previously, the turning-on of the first odd line starts with a turning-on of switches Q 1 and Q 4 (time t 0 ), with switches Q 2 and Q 3 as well as switches S 1 and S 2 being off. Voltage VCo is then brought to level V ON and voltage VCe is brought to level V OFF . The luminance reference values are provided by the column control circuit (not shown). In the indicated voltage levels, the influences of the different voltage drops of the switching elements in the ON state are neglected.
At a time t 1 , subsequent to the end of the addressing of the first odd line, switches Q 1 and Q 4 are turned off and switch S 1 is turned on to precharge the first even line by flowing of a current through diode D 2 , inductance L, and switch S 1 . The current through inductance L increases up to a maximum Ip before canceling at a time t 2 . Between times t 1 and t 2 , voltage VCe switches from level V OFF to a level dose to level V ON and voltage VCo switches from level V ON to a level dose to level V OFF . The interval between times t 1 and t 2 is a function of equivalent capacitance Co and of the value of inductance
L ( t 2 - t 1 = π 2 · Co · L ) .
The maximum current Ip also depends on equivalent capacitance Co and on inductance L and is equal to V ON -V OFF ·√{square root over (Co/2L)}.
From a time t 3 , subsequent to time t 2 , switch S 1 is off and switches Q 3 and Q 2 are on to complete the charge of the cells of the even line (voltage VCe) to level V ON and end the discharge of the cells of the odd line (voltage VCo) to level V OFF . The addressing of the cells of the first even line is performed during this phase.
At the end of this addressing phase (time t 4 ), switch S 2 is turned on while switches Q 2 and Q 3 are off to cause a precharge of the cells of the next odd line. A current then flows through diode D 1 , inductance L, and switch S 2 . This current is of course in reverse direction with respect to the current between times t 1 and t 2 . It also has a non-linear increase and decrease and a peak value V ON -V OFF ·√{square root over (Ce/2L)} which is a function of equivalent capacitance Ce. Similarly, the interval between times t 4 and t 5 during which a current flows through inductance L, and which conditions the duration for voltages VCe and VCo to respectively reach levels dose to levels V OFF and V ON , depends on equivalent capacitance
Ce
(
t
5
-
t
4
=
π
2
·
Ce
·
L
)
.
The same operation is then repeated for the next odd line (times t 0 ′, to t 2 ′), etc.
An advantage of this embodiment of the present invention is that it decreases losses by taking advantage of the resonance introduced by inductance L in charge transfer phases. Losses P during this resonance phase can be expressed as:
P = f · C eq · π · ( V ON - V OFF ) 2 4 · 2 C eq L · R eq ,
where Ceq=Ce=Co and where Req represents the sum of the resistances of the conductive row lines and of the switches in the on state. In the former example of a 4.7-nF equivalent capacitance Ceq, of a 166-kHz frequency, of a 35-volt voltage V ON , and of a −25-volt voltage V OFF , and estimating at 20 ohms the total equivalent resistance of the lines, a 0.213-watt loss to be compared with the previously-obtained 1.4 watts is obtained
Another advantage of the resonance is that it smoothes switching edges. The value of inductance L (for a given panel) sets the dV/dt This enables decreasing cell-to-cell interferences.
FIG. 6 shows the electric diagram of a circuit for controlling switches S 1 and S 2 of FIG. 4 , here made in the form of MOS transistors. The cells of an even and odd line are symbolized by the respective equivalent capacitances Ce and Co in series with respective resistances Re and Ro between terminals 33 , and 32 , respectively, and a grounded terminal 44 .
The respective gates of transistors S 1 and S 2 are connected to terminals 33 and 32 by parallel assemblies, each formed of a resistor R 11 or R 12 , of a capacitor C 1 or C 2 (possibly formed of the gate-source capacitance of transistor S 1 or S 2 ), and of a Zener diode DZ 1 or DZ 2 (or another voltage-limiting element). The function of diodes DZ 1 and DZ 2 is to protect the gates of transistors S 1 and S 2 . These gates are further connected to the respective junction points of diodes D 11 and D 12 , and D 13 and D 14 , connecting a terminal 40 , connected by a switch S 3 to a source 41 of a preferably constant current ( 10 ), to a terminal 42 of application of voltage V ON . Source 41 is supplied by a D.C. voltage Vcc, at least greater than voltage V ON plus the on-state gate-source voltage (Vgs ON ) of transistor S 1 or S 2 . Diodes D 11 to D 14 selectively charge the gate of transistor S 1 or S 2 having its conduction terminal on the side of switches Q at the low level (typically V OFF at the beginning, but the selection operates as long as the voltage is smaller than V ON ). Resistors R 11 and R 12 are used to discharge the gates of transistors S 1 and S 2 in the quiescent state.
Switch S 3 is controlled to be turned on at times t 1 , t 4 , t 1 ′, etc. to initiate the power recovery phases.
Taking the example of time t 1 , that is, once the addressing of an odd line is over, the turning-on of switch S 3 causes the flowing of a current from current source 41 through diode D 11 to charge capacitor C 1 in parallel on the gate of transistor S 1 . The flowing to terminal 33 rather than to terminal 32 results from the fact that, on turning-off of switches Q 1 and Q 3 , terminal 32 is approximately at level V ON (at the voltage set by the cells of the odd line) while terminal 32 approximately is at level V OFF (voltage of the cells of the even line). The fact that terminal 42 is at voltage V ON takes part in the blocking of the upper portion (in the arbitrary orientation of the drawing) of the assembly. A current also flows through diode DZ 1 to start charging the cells of the even line (Ce, Re).
Once capacitor C 1 has reached a sufficient charge, it causes the turning-on of transistor S 1 . In fact, as compared with the illustration of FIGS. 5A to 5G , this translates as a slight delay (set by the on-state gate-source voltage Vgs ON of transistor S 1 , the current in source 41 , and capacitor C 1 ) on turning-on of switch S 1 with respect to time t 1 . A flowing of the current then establishes from the cells of the odd line (Co, Ro), through diode D 2 , inductance L, and switch S 1 , to reach the cells of the next even line (Ce, Re). Transistor S 1 remains on as long as the voltage across its gate is positive and is greater than the threshold set by diode DZ 1 . Switch S 3 remains on until capacitor C 1 has a sufficient charge (for example, on the order of from 10 to 12 volts). This amounts, for example, to a few hundreds of nanoseconds.
At time t 2 , the voltage of capacitor C 1 plus the voltage between point 33 and the ground becomes sufficient to turn on diode D 2 . This enables discharge of capacitor C 1 and blocking of transistor S 1 . As soon as switches Q 2 and Q 3 are turned on (time t 3 ), voltage V ON -V OFF between terminals 33 and 32 confirms the blocking of the low portion of the assembly by the discharge of capacitor C 1 through diode D 12 and switch Q 3 . Further, the charge of the cells of the even line and the discharge of those of the odd line are carried on.
At the end of the even line cell addressing period (time t 4 ), the voltage of terminal 33 is V OFF , that of terminal 32 is V ON . Accordingly, a turning-on of switch S 3 from time t 4 causes the flowing of a charge current of capacitor C 2 to turn on transistor S 2 . An operation similar to that described hereabove for switch S 1 is repeated for switch S 2 .
An advantage of the circuit of FIG. 6 is that it enables controlling both switches S 1 and S 2 by means of a same control circuit, and thus solving the problems of floating voltages of the conventional circuit ( FIG. 3 ). The control signal of switch S 3 , which is designated CT in FIG. 6 , is, for example, generated by a circuit of control and synchronization ( 5 , FIG. 2 ) of the screen circuits (generally, of microprocessor type).
As a specific example, a circuit such as illustrated in FIG. 6 may be formed with components having the following values:
L=100 μH; C 1 =C 2 =1 nF; R 11 =R 12 =100 kΩ; and DZ 1 =DZ 2 =10 Volts.
FIG. 7 illustrates a variation of the circuit of FIG. 4 according to which two inductive elements L 1 and L 2 replace the conventional resistors of the assembly of FIG. 3 according to another embodiment of the present invention. Such a variation enables decreasing losses with respect to this conventional assembly of FIG. 3 but it does not enable simplifying the control as in the assembly of FIGS. 4 and 6 .
Of course, the present invention and embodiments thereof are likely to have various alterations, modifications, and improvements which will readily occur to those skilled in the art In particular, the sizing of the circuit components according to the screen type (especially its scan frequency and the equivalent capacitances of its cells), is within the abilities of those skilled in the art. Further, the turn-on and turn-off times of the different switching elements which have been shown as being simultaneous may in practice be shifted in time, for example, to avoid simultaneous conduction periods risking short-circuiting the supply lines. Such switching elements arbitrarily designated as switches are in practice MOS transistors (except for switch S 3 which is, preferably, a bipolar transistor).
Such alterations, modifications, and improvements are intended to be part of this disclosure, and are intended to be within the spirit and the scope of the present invention. Accordingly, the foregoing description is by way of example only and is not intended to be limiting. The present invention is limited only as defined in the following claims and the equivalents thereto.
Flat screens such as LCD panels including embodiments of the present invention may be contained in a variety of different types of electronic devices, such as portable devices like cellular phones, personal digital assistants (PDAs), calculators, video/audio players, and so on, and may be contained in electronic systems such as computer systems.
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A charge transfer circuit of a liquid crystal display includes at least one inductive element connectable between first and second common terminals, to a first and to a second groups of lines of the display, respectively.
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FIELD OF THE INVENTION
[0001] This invention relates to cooling devices generally, and is more specifically related to a cooling device having particular utility for outdoor use.
BACKGROUND OF THE INVENTION
[0002] There is a need for outgoing environs more comfortable during hot weather. It is not practical to provide ordinary air conditioning for spaces that are not enclosed. It has long been known that evaporation of water will evaporate quickly and provide a cooling effect. However, nozzles that simply atomize and spray water do not sufficiently provide a cooling effect for surrounding air, and people and objects in vicinity of the device will be dampened by such a spray.
SUMMARY OF THE PRESENT INVENTION
[0003] The present invention is a cooling device having a series of baffles that deflect a falling stream of liquid coolant. An air handler, such as a fan, pulls air through the liquid coolant. The air moved by the air handler through the liquid coolant is cooled, and the cooled air exits the device to cool the surrounding environs.
DESCRIPTION OF THE DRAWINGS
[0004] FIG. 1 is a perspective view of an embodiment of the device, with arrows indicating air flow through the device.
[0005] FIG. 2 is a sectioned view of an embodiment of the invention taken essentially along line 2 - 2 of FIG. 1 .
[0006] FIG. 3A is a partial view of the upper portion of the device.
[0007] FIG. 3B is a partial view of a lower portion of the device.
DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENT
[0008] A preferred embodiment of the present invention takes the form of a patio table having an umbrella 2 . A patio table of this type is a suggestion for a possible use of the invention, however the device is useful for cooling any area as will be seen, and is not necessary that the device have a table or umbrella affixed.
[0009] A liquid coolant 4 , which may be water, is placed in the base 6 of the cooling tower, and is pumped into a tray that is part of distributor 8 , located in the upper portion of the cooling tower. Water drips from multiple orifices 10 in the distributor, and onto multiple baffles 12 that are positioned around the tower, and underneath the orifices. Air inlets 14 are positioned under the baffles. As the water drips on the baffles, the water is diffused by the baffles. The fan 16 in the upper portion of the tower pulls air through the inlets, and the air passes through the water. Heat is removed from the air and transferred to the water. The air cooled by the water is delivered outside of the tower, through outlets 18 in an upper portion of the tower. The tower may have a dome, or other air directing device, such as an umbrella 20 , which directs the cooled air as it exits the device.
[0010] Turning now to the drawing figures, FIG. 2 shows a series of baffles 12 that are positioned within a housing. The series of baffles may be positioned generally vertically, and are preferred to be increasingly closer together toward the bottom of the device. As shown in FIG. 3A , a liquid coolant is directed on to the top baffle. The liquid coolant, which is preferred to be water, but which could be other liquids, strikes the top baffle, and then drops to the next lower baffle. This process is repeated until the coolant exits the last baffle and is collected in the reservoir in the bottom of the housing.
[0011] Below each baffle is an air inlet that is formed in the housing.
[0012] As shown in FIG. 3A , air is pulled through an inlet that is effectively below the baffle. The coolant is splattered, and somewhat atomized, by striking the baffles, and the air entering the housing through the inlet is cooled by exposure to the multiple surfaces of the water created by diffusing the water by means of the baffles. The air is then pulled through the top of the housing by an air handler, where the cooled air exits the housing. A deflector 22 in the upper part of the housing, and the umbrella, direct the cool air toward the persons sitting around the table 24 , and persons who are otherwise in the area of the device.
[0013] The coolant, which may be water, is pumped from the reservoir and through the center of the tower and into a liquid coolant source for the baffles. The liquid coolant source may be a distributor having a series of voids that allow the coolant to drip directly on the baffles as shown in FIG. 3A . The distributor 8 may be an annular trough that receives liquid coolant that is pumped from the reservoir and through the conduit 26 by a pump that is located in the reservoir in a lower portion of the housing. The weight of the coolant in the lower portion of the reservoir assists in stabilizing the device.
[0014] The reservoir may be either manually filled with water on a periodic basis, or may be plumbed and connected to a larger water source. A float actuated valve 28 may be used to control the level of the water within the reservoir.
[0015] The air handler pulls air through the plurality of inlets in the housing. It is preferred that at least one inlet is associated with each baffle. As shown in the drawings, the inlet is constructed to direct air below the baffle after the coolant strikes the baffle. The inlets could also be positioned above the baffles.
[0016] The air handler may be a fan. It is preferred that the fan is positioned above the baffles and below the exhaust as shown in FIG. 3A . There is a relatively large void through the center of the housing which allows for sufficient air flow. The void in the housing extends through the center of the distributor 8 .
[0017] Excepting the air inlets and outlets, the device is preferred to be enclosed, so that the liquid coolant is retained within the device. For example, the water falling against the baffles is preferred to not be exposed to an exterior of the device, so that the water is retained in the interior of the housing.
[0018] The device is preferred to be portable, and capable of movement by one or two persons, so that it can be positioned as desired.
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A cooling device has a series of baffles that deflect a falling stream of liquid coolant. An air handler, such as a fan, pulls air through the liquid coolant. The air moved by the air handler through the liquid coolant is cooled, and the cooled air exits the device to cool the surrounding environs.
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BACKGROUND OF THE INVENTION
The present invention relates generally to improvements in display and dispensing devices and it relates particularly to an improved collapsible structure for displaying a product and facilitating the individual dispensing of the product and the replenishment of the depleted product.
In the merchandising of many products, the products are conventionally prepackaged in small individual containers such as bottles, jars, small cartons and the like, examples of such products being lotions and solid and liquid medications of various type. The prepackaged products are usually displayed on and dispensed from permanently constructed shelves or are located on counters where they are exhibited in a similar manner. However, it is frequently necessary or desirable to display and dispense a product in an area separate from the usual product display area where the product is readily observable and obvious and where it is conveniently available and dispensable. Heretofore many structures and arrangements have been proposed and employed for displaying and dispensing prepackaged products in areas displaced or isolated from the usual product and article display and dispensing areas, such as shelves, counters and the like. However, these earlier structures possess numerous drawbacks and disadvantages. They are expensive structures, awkward and time consuming to assemble, inconvenient and unreliable to operate, unattractive, of little versatility and adaptability and otherwise leave much to be desired.
SUMMARY OF THE INVENTION
It is thus a principal object of the present invention to provide an improved display and dispensing device.
Another object of the present invention is to provide an improved device for displaying and individually dispensing prepackaged products.
Still another object of the present invention is to provide an improved display device for individually dispensing products prepackaged in small bottles, jars, cartons and the like.
A further object of the present invention is to provide an improved product display and dispensing device which is collapsible to a highly compact state to facilitate its storage and shipping and in which the dispensed product packages may be easily and quickly replenished.
Still a further object of the present invention is to provide an improved device of the above nature characterized by its reliability, attractive appearance, ease and convenience of assembly and use and its great versatility and adaptability.
A display and dispensing device in accordance with the present invention includes a collapsible base unit advantageously formed of cardboard or the like, having, in its erected condition, relatively low front and relatively high rear walls and side walls hinged along adjacent edges, the side walls having coplanar, parallel rearwardly upwardly inclined top edges, a prepackaged product dispensing unit having a bottom wall resting on the top portion of the base unit and restricted against downward movement and including a cover panel swingable between open and closed positions and releasably locked in its closed position, the cover panel having an opening in its lower border, providing access to the interior of the container unit and a partition member having transversely spaced longitudinal package guideways nested in the container unit. Advantageously, inwardly directed flaps are formed at the upper portions of the side wall edges and a platform rests on the lower portions of the side edges and underlies the container unit bottom wall and coupling means are formed on the base unit rear wall and the container unit bottom wall interlocking the base and container unit.
The improved display and dispensing unit is easy to quickly erect and assemble without the use of tools, is convenient and reliable to use, is inexpensive, rugged and highly attractive and is of great versatility and adaptability.
BRIEF DESCRIPTION OF THE DRAWINGS
FIG. 1 is a front perspective view of a display and dispensing device embodying the present invention shown in an assembled and erected condition;
FIG. 2 is a front perspective view of the base portion thereof shown in the process of assembly;
FIG. 3 is a rear fragmentary perspective view of the device shown in the process of interlocking the container and base portions thereof;
FIG. 4 is a front perspective view of the container portion as shown in detached and open condition;
FIG. 5 is a view similar to FIG. 4 but with the container shown in closed condition;
FIG. 6 is a sectional view taken along line 6--6 in FIG. 5;
FIG. 7 is a sectional view taken along line 7--7 in FIG. 5; and
FIG. 8 is a sectional view taken along line 8--8 in FIG. 5.
DESCRIPTION OF THE PREFERRED EMBODIMENT
Referring now to the drawings which illustrate a preferred embodiment of the present invention, the reference numeral 10 generally designates the improved display and dispensing device which comprises a base unit 11 and a container unit 12. The base unit 11 is formed of two sections, a body section 13 integrally formed preferrably of cardboard in the conventional manner by stamping and shaping and a platform section 14 likewise stamped and shaped preferrably of cardboard.
The base unit body section 13 includes a rearwardly upwardly inclined short rectangular front wall 16 and an upright high rear wall 17. Extending between and self or live hinged to corresponding edges of front and rear walls 17 are similarly shaped side walls 18, walls 16,17 and 18 being formed of a single sheet with the free contiguous edges of the sheet being joined in any suitable manner to form body member 13. Formed along the bottom edges of and integral with walls 16,17 and 18 are flaps 19 which are folded inwardly to define foot pieces.
The top edges 20 of side walls 18 are parallel and coplanar and rearwardly upwardly inclined preferrably at an angle greater than 45 degrees to the horizontal, each of the edges 20 terminating at its front end in a shoulder defining edge 21 perpendicular to and projecting upwardly from respective inclined edge 20. A flap 22 is formed along the upper portion of each inclined edge 20 and a notch, perpendicular to inclined edge 20 is formed in the upper border of each side wall 18 intermediate the ends of edge 20. Medially formed in the upper border of rear wall 17 is a vertical slot 24 joining a horizontal slot 26 which delineate the bottom and inner spaced confronting edges of a pair of hinged flaps 27. Projecting medially upwardly from and coplanar with front wall 16 is a short tab 28.
Platform section 14 includes a rectangular panel 29 of greater width than the distance between side walls 18 and of a length about equal to the distance between slots 23 and shoulders 21. A downwardly projecting flap 30 extends along the full length of the rear edge of panel 29 and is provided with notches 32 which engage slots 23 and a flap 33 projects upwardly from the front edge of panel 29 and shoulders 21 in the assembled erected condition of base unit 11.
The container unit 12 comprises a body portion 34, a cover member 36 and a guideway insert 37. Body portion 34 is formed of a unitary cardboard blank and includes a rectangular bottom wall 33, front and rear walls 39 and 40 and side walls 41 and 42 projecting perpendicular from the edges of bottom wall 38 and coextensive therewith. Each of walls 39-42 includes an outer panel 43 joined along its lower edge to bottom wall 38 and an inner panel 44 joined along the upper edge of outer panel 43 and provided along its bottom edge in a plurality of longitudinally spaced depending tabs 46 engaging corresponding slots in bottom wall 38.
Cover member 36 includes a main rectangular panel 47 suitably hinged along a longitudinal edge thereof to the top edge of body portion side wall 41. A score line 48 parallel to the front edge of panel 47 is formed in panel 47 a distance from the bottom edge thereof slightly greater than the length of a bottle or other package P dispensed by device 10. A score line 48 delineates a forward separable panel whose detachment from panel 47 exposes the bottom row of products P when cover 36 is in closed position. It should be noted that panel 49 may have a rectangular cut-out 50 at its inner end to expose one of the products P even in the closed condition of cover member 36.
Closure top and free end side flaps 51 and 52 project perpendicularly inwardly from corresponding edges of panel 47, and in the closed condition of cover member 47 flap 31 engages the inside face of rear wall 40 and flap 52 engages the outside face of side wall 42. Cemented to the outside face of side 42 is a pair of longitudinally spaced rectangular Velcro sheet separable fastener units 53 and cemented to the inside face of flap 52 is a pair of correspondingly spaced rectangular Velcro sheet units 54 which separably engage respective fastener units 53 in the closed condition of cover member 36 to releasably lock the cover member in its closed condition.
Integrally formed with and stamped from the medial rear border of container unit bottom wall 38 is a depending locktab 56 having laterally extending hinged butterfly or wing flaps 57. A corresponding opening 58 is formed in bottom wall 38, locktab 56 being swingably connected to the front lateral edge of opening 58. A notch is medially formed in the top edge of opening 58 to provide finger access to tab 56.
Nesting in the lower portion of container body portion 34 and resting on bottom wall 38 and extending between front and rear walls 39 and 40 and side walls 41 and 42 is guideway insert 37 which is formed of a unitary sheet of cardboard or other suitable material. Insert 37 is shaped to form a plurality of parallel side-by-side longitudinally extending guideways 59 of arcuate transverse cross-section of somewhat less than 180 degrees and of a diameter about equal to that of product bottle P. The adjacent edges of successive guideways 59 are integrally joined by cusps 60.
In the collapsed condition of base unit 11 body member 13 is folded along the hinge lines between contiguous edges of walls 16,17 and 18 to a lay flat condition with flaps 19 and 20 being coplanar with corresponding walls. To assemble the device 10 the body member walls 16,17 and 18 are swung to their expanded position as shown in FIGS. 1 and 2 and the flaps 19 and 22 are swung inwardly. The base unit is then locked in its erected position by applying platform member 14 with flap 33 bearing on the rear face of tab 28 and the notches 32 engaging slots 23 to retain the body member and platform in the erected assembled condition.
The lock tab 56 is opened and swung downwardly from the bottom wall of container unit 12 which is positioned above platform 14 and the opposite wing flaps 57 are folded inwardly and the tab thus inserted through slot 26. Wing flaps 57 are then opened up to securely lock container unit 12 and base unit 11 with the dispensing and display device in assembled erected condition.
The panel 49 is detached and separated from the remainder of cover panel 47 along score line 48 to expose and provide access to the bottom row of bottles P which are slideably located end to end as columns in guideways 59. As a bottom bottle P is withdrawn through the bottom opening the column of successive end to end bottles is gravity fed downwardly along the respective guideway to replace the withdrawn bottle. When the bottles in the container are depleted they are replenished merely by unlocking flap 42 by separating fastener members 53 and 54, opening cover member 46, filling guideways 59 with bottles P and then closing and relocking cover member 36.
While there has been described and illustrated a preferred embodiment of the present invention it is apparent that numerous omissions, additions and alterations may be made without departing from the spirit thereof.
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An article display and dispensing structure includes a cardboard base unit collapsible to a lay flat condition and having side walls with upwardly rearwardly inclined edges on the lower part of which is located a separable platform panel and an inclined container unit resting on the inclined edges and platform and enclosing a partition unit having open topped longitudinal passageways slideably carrying end to end bottles, the container being closed by a swingable rectangular cover releasably locked in closed position by Velcro coupling sections and having a transverse line of weakness delineating with the bottom front edge of the cover member a separable panel whose separation provides access to the lowermost bottles for individual removal.
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BACKGROUND OF THE INVENTION
1. Field of the Invention
The present invention relates to the vaporization of liquid hydrocarbon fuel for use in conventional steam reformers, thermal steam reformers, and advanced reformer concepts.
2. Description of the Prior Art
It is known to use hydrogen as a source of energy in fuel cells. One method of obtaining hydrogen fuel is by conventional steam reforming in which vaporized hydrocarbon fuel is reacted with steam in the presence of a catalyst to produce hydrogen (hydrocarbon+H 2 O+energy→3H 2 +CO 2 ). The liquid hydrocarbon fuel which is to be reacted must be introduced into the steam reforming reactor in vapor phase.
One method of vaporizing the liquid hydrocarbon fuel is to pass the liquid through a heat exchanger to vaporize the liquid before introducing it into the steam reformer. A disadvantage with this method is that hydrocarbon residue tends to bake and accumulate on heat exchanger walls, thus reducing heat exchanger efficiency and eventually clogging the heat exchanger.
One method of reducing hydrocarbon accumulation and clogging is to mix the liquid hydrocarbon fuel with a vapor prior to introduction into the steam reforming reactor. U.S. Pat. No. 3,698,957 discloses a method wherein steam from a heat exchanger is mixed with liquid hydrocarbon fuel to produce vapor which is injected into the reformer reactor. There are two drawbacks to this method. In order for the heat exchanger to heat water into steam having a sufficiently high energy content to vaporize the liquid hydrocarbon fuel, a high temperature energy source must be used in the heat exchanger. Also the liquid hydrocarbon fuel may contain significant amounts of sulfur, which may have to be removed from the fuel before it is introduced into the reformer reactor. A conventional desulfurizer is used for this purpose. However, the desulfurizer cannot tolerate significant amounts of oxygen, and therefore, steam cannot be used to vaporize the liquid fuel.
It is also known to use recycled hydrogen vapor from the reformer reactor to vaporize the liquid hydrocarbon fuel. The hydrogen vapor must be heated in a heat exchanger prior to mixing with the liquid hydrocarbon fuel. A disadvantage of this method is that the energy source used to heat the hydrogen vapor in the heat exchanger must have a relatively high temperature.
To summarize, the prior art method of vaporizing liquid hydrocarbon fuel is a one step process wherein the vapor to be mixed with the liquid hydrocarbon is heated in heat exchangers to temperatures in excess of 1000° F. In order to heat the vapor to such high temperatures, the heat exchanger must use a high temperature energy source, generally, vapor having a specific heat in the range from 0.2 to 1 Btu/lb°F. and having a temperature between about 1100° and 1200° F.
It is an object of the present invention to provide vaporized liquid hydrocarbon fuel without necessitating reliance on high temperature energy sources for the heat exchanger.
It is a further object of the present invention to provide a method of vaporization of liquid hydrocarbon fuels that reduces hydrocarbon accumulation on heat exchangers.
SUMMARY OF THE INVENTION
The present invention provides a method for vaporization of liquid hydrocarbon fuel wherein liquid hydrocarbon fuel is mixed with vapor to provide a first vapor product, the first vapor product is heated in a heat exchanger and then mixed with additional liquid hydrocarbon fuel to provide a second vapor product which may be used for additional vaporization stages or introduced in the reformer reactor or desulfurizer.
In one embodiment of the invention, the vapor comprising hydrogen, which is recycled from the steam reformer, is heated in a heat exchanger prior to mixing with liquid hydrocarbon fuel. The heat exchanger can use energy sources having relatively low energy content. The heated hydrogen vapor is then mixed with liquid hydrocarbon fuel to form a first vapor product. The first vapor product is then heated in a heat exchanger which may also use energy sources having relatively low energy content and is then mixed with additional liquid hydrocarbon fuel to provide a second vapor product which is ultimately introduced into a conventional reformer reactor.
BRIEF DESCRIPTION OF THE DRAWING
The FIGURE is a diagramatic flow plan of a two-stage vaporization system.
DETAILED DESCRIPTION OF THE INVENTION
The invention is described with reference to the FIGURE.
Vapor having a temperature between about 200° F. and about 600° F. is introduced into heat exchanger 2 wherein the vapor is heated to between about 300° F. and about 900° F. The heated vapor is delivered to mixer 4 through line 3 where the vapor is mixed with liquid hydrocarbon fuel which is delivered to mixer 4 through line 5. The mixing of the liquid hydrocarbon fuel and the vapor in mixer 4 allows for the vaporization of the liquid hydrocarbon fuel to produce a first vapor product having a temperature between about 200° F. and about 700° F.
The first vapor product from mixer 4 is delivered through line 6 to heat exchanger 7 wherein the first vapor product is heated to a temperature between about 300° F. and about 900° F. The first vapor product having an elevated temperature is delivered from heat exchanger 7 through line 8 to mixer 9 where it is mixed with additional liquid hydrocarbon fuel delivered through line 10 into mixer 9 to provide a second vapor product. The second vapor product may be delivered through line 11 to a conventional steam reforming reactor 12 wherein the second vapor product is reacted to form hydrogen vapor. However, if the liquid hydrocarbon fuel contains substantial quantities of sulfur, the second vapor product will be delivered through line 13 to a conventional desulfurizer 14 and then delivered through line 15 to steam reformer 12.
Steam reformer 12 produces a vapor comprising hydrogen. A portion of the hydrogen vapor is recycled and delivered through line 1 to heat exchanger 2. Another portion of the hydrogen vapor is removed from the system through line 16 to be used eventually as a fuel in a fuel cell.
The vapor can be any gas having heat transfer characteristics such that when the vapor is heated and mixed with liquid hydrocarbon fuel, the liquid hydrocarbon fuel is vaporized. It is preferred that the vapor have a relatively high specific heat. When the process of the present invention is used for steam reforming of hydrocarbon fuels, the specific heats of the vapors range from about 0.2 to about 1 Btu/lb°F., and particularly from about 0.5 to about 0.8 Btu/lb°F. In the preferred embodiment of the invention the vapor comprises at least about 50 volume percent hydrogen the remainder being carbon dioxide and steam. When the liquid hydrocarbon fuel does not include a substantial amount of sulfur or the reformer reactor is sulfur tolerant, the vapor can comprise as much as 100% water in the form of steam. The source of steam may be the same source of steam that is necessary to provide steam to the reforming reactor.
The liquid hydrocarbon fuel which is to be vaporized may be any type of liquid hydrocarbon fuel such as, for example, naphtha, gasoline, kerosene or oil. Mixtures of different types of liquid hydrocarbon fuels may be used. The preferred source of liquid hydrocarbon fuel for use in steam reforming is naphtha having an end boiling point between about 200° F. to about 400° F. The liquid fuel may be at room temperature when mixed with the vapor, although liquid fuels having temperatures in excess of room temperatures may also be used.
One advantage of the present invention is that heat exchangers 2 and 7 may use energy sources having relatively low energy content. Heat exchanger vapor having relatively low energy content is delivered to heat exchangers 2 and 7 through conduits 17 and 18. The heat exchanger vapor may be steam or recycled hydrogen gas from another part of the reformer reactor system. In the prior art wherein the liquid hydrocarbon fuel was vaporized in a single stage process, the vapor had to be heated to relatively high temperatures, that is temperatures in excess of about 1000° F., which required the heat exchanger to use energy sources having relatively high energy content, that is, vapors having specific heats in the range from about 0.2 to about 1 Btu/lb°F. and having temperatures in the range from about 1100° to 1200° F. With the present invention, which is at least a two-stage process, the heat exchangers may use sources having a relatively low energy content. Preferably, the heat exchangers may use vapor having specific heats in the range from about 0.2 to 1 Btu/lb°F. and having a temperature below about 1000° F., and even below about 750° F. Although the ability of the heat exchangers to elevate the temperature of the vapor to be mixed with the liquid hydrocarbon fuel is dependent on the efficiency of the heat exchangers, the mass flow of the heat exchange vapor through the heat exchanger and other parameters, it should be understood that, all other parameters remaining constant, the heat exchangers of the present invention require a lower temperature energy source than the prior known methods.
It is preferred that the vapor delivered through line 3 to mixer 4 have a temperature sufficient to vaporize the liquid hydrocarbon fuel delivered to mixer 4 through line 5. It is undesirable to have liquid hydrocarbon fuel remaining after mixing in mixer 4 because liquid hydrocarbon fuel may tend to clog heat exchanger 7. It is preferred to mix liquid hydrocarbon fuel and vapor of about 300° F. to about 900° F. in a weight ratio of fuel to vapor from about 0.1 to about 1.0.
The first vapor product which is delivered through line 6 to heat exchanger 7 is a mixture of vaporized hydrocarbon fuel and vapor. It is preferred that the first vapor product be heated by heat exchanger 7 to a temperature sufficient to vaporize the additional liquid hydrocarbon fuel which is delivered via line 10 to mixer 9. It is preferred that the first vapor product have a temperature after it has been heated in heat exchanger 7 between about 300° F. and 900° F. and that it be mixed with liquid hydrocarbon fuel in mixer 9 in a liquid fuel-to-first vapor product weight ratio from about 0.1 to about 0.5.
The heat exchangers described in connection with the present invention can be any conventional heat exchanger that provides for heat exchange between gases. The mixers described in the present invention can be any conventional mixer which will provide for the mixture of liquid hydrocarbon fuel with vapor to provide a vapor product. It is known to use a mixer which is simply a joinder of two conduits into one conduit. In the preferred type of mixer, after the liquid fuel in one conduit and the vapor in another conduit are delivered to a single conduit, the mixture is flowed into a chamber having obstructions therein which provide for mixing and vaporization.
Although the process of the present invention has been described as a two-stage process, the concept of staged vaporization of liquid hydrocarbon fuel can be extended to provide methods having three or more stages.
ILLUSTRATIVE EXAMPLE
Hot recycled vapor from the steam reforming reactor containing about 57 volume percent hydrogen and about 43 volume percent carbon dioxide and water, having a specific heat of about 0.6 Btu/lb°F. and having a temperature of about 700° F. was mixed with heavy naphtha (400° F. end boiling point). The vapor was mixed with liquid naphtha in a weight ratio of vapor to naphtha of 1:0.6 and provided a first vapor product containing vaporized naphtha and having a temperature of about 400° F. The first vapor product was introduced into a heat exchanger which used a low temperature energy source, that is, a vapor containing about 57 volume percent hydrogen, 43 volume percent carbon dioxide and water, having a specific heat of about 0.6 Btu/lb°F. and having a temperature of about 900° F. The temperature of the first vapor product was elevated by the heat exchanger to about 800° F. The first vapor product was mixed with additional liquid hydrocarbon fuel in a weight ratio of vapor to naphtha of 1:0.3 to provide a second vapor product which was delivered to the desulfurizer and eventually to the steam reforming reactor.
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 will be understood that the present invention has been described by way of illustration and not limitation.
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A method for vaporization of liquid hydrocarbon fuel wherein liquid hydrocarbon fuel is mixed with vapor to provide a vapor product which is heated. The heated vapor product is mixed with additional liquid hydrocarbon fuel to provide a second vapor product comprising vaporized hydrocarbon fuel. The heating of vapor product and mixing of additional liquid hydrocarbon fuel can be done until a desired amount of liquid hydrocarbon fuel is vaporized.
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BACKGROUND OF THE INVENTION
The present invention relates to a dual-circuit pressure control valve for hydraulic brake systems having two control valves arranged in a housing in a parallel side by side relationship each assigned a different one of the two brake circuits, each of the two control valves having a separate control piston located between an associated inlet chamber and an associated outlet chamber, and the control pistons are subjected to a common control force acting on the pistons through the intermediary of a preload distributor.
In a known dual-circuit pressure control valve of the aforementioned type such as disclosed in German Pat. DE-OS No. 2,614,080, the two control pistons are arranged in a parallel side by side relationship. The preload distributor includes a semicircular disc made of elastic material which abuts with its entire circumferential surface on a supporting element with the same radius. The elastic disc has both end surfaces embraced by further wall components of the supporting element and which has a rigid beam at the diameter surface, against which beam the control pistons are adapted to bear. The supporting element is carried by a lever upon which a control force acts which is variable dependent upon the vehicle's axle load. With varying pressures prevailing at the outlet of the two pressure control valves, the system comprising the two control pistons and the distributor will be displaced in such a way that additional pressure fluid is fed to the brake circuit having the lower pressure until the balance in pressure is re-established. Thus, it is possible to compensate to a certain extent for discrepancies in tolerance occurring in the manufacture of the control valves. Moreover, if one brake circuit fails, the pressure in the still intact brake circuit is allowed to increase. It has to be taken into consideration, however, that the distributor is largely made of elastic material, in particular rubber, and is, therefore, subjected to substantial aging and wear phenomena. This is especially true due to the considerable fluctuations in temperature occurring in automotive vehicles, due to the ingress of dirt and the strong forces to be absorbed during each braking operation, which leads to a deformation or a grinding along the supporting surface. Besides, difficulties arise if the two control pistons do not act upon the distributor precisely symmetrically.
SUMMARY OF THE INVENTION
It is an object of the present invention to provide a dual-circuit pressure control valve of the type referred to hereinabove, in which all tolerances of the control valves are compensated for and in which the two outlet pressures of the pressure control valve are equal during the entire life span of the device.
A feature of the present invention is the provision of a dual-circuit pressure control valve for hydraulic brake systems comprising two control valves disposed in a housing in a parallel side by side relationship, each of the two control valves controlling a different one of two brake circuits, having a control piston disposed between an inlet chamber and an outlet chamber and subjected to a common control force acting on each of the control pistons through a preload distributor; and means disposed in the housing disposed between the outlet chamber of one of the two control valves and the outlet chamber of the other of the two control valves to provide a hydraulic balancing of the outlet pressure in each of the outlet chambers.
As a result of this measure, all manufacturing tolerances of the control valves and of the preload distributor are compensated for and the closure travel of the control valves is kept small.
In a suitable improvement upon the subject matter of the present invention, the means for the hydraulic balancing is a piston with end surfaces of equal size, which piston is acted upon by the pressures in the outlet chambers and on account of whose movement the valve of the one brake circuit is adapted to be controlled. It is attained by this arrangement that the piston has to move only in the area of the closure travel of the valve. To keep the loss in volume of the one brake circuit at a minimum possible rate in the event of failure of the other brake circuit and to ensure an increase of the change-over point in the event of a circuit failure independently of the piston's diameter, it is suggested that the piston be displaceable within limits. This may be accomplished in a particularly simple way by providing the piston with a radial extension which is located between a shoulder and a stop ring fastened in the housing. Advantageously, the radial extension is formed by a collar arranged at the end surface of the piston defining the outlet chamber.
To enable the piston to directly control the valve without insertion of transmitting members, the piston and the stepped piston are arranged in series on a common axis.
For increasing the change-over point of the intact brake circuit to the double pressure valve upon failure of the other brake circuit, the preload distributor is favorably guided in the direction of the axes of the stepped pistons. To vary the control force acting on the stepped pistons dependent upon the vehicle's axle load, it is advantageous that the preload distributor is a lever adapted to swivel around a transverse axis of the stepped pistons. Preferably, the stepped piston includes a clearance relative to the preload distributor. It is thereby obtained that a valve closes to begin with and that a further pressure increase in this circuit is effected by controlling the valve through the piston. To be able to determine the clearance exactly, it is suitable to provide a means for adjustment of the clearance. A spring may be arranged between the stepped piston and the preload distributor which will load the stepped piston when depressurized back to its end position close to the outlet chamber. The same effect as that of the clearance between stepped piston and preload distributor may be achieved by providing the control valves with different closure travels.
A dual-circuit pressure control valve, in which the control pistons are of smaller diameter, is advantageously constructed in such a manner that the control valves each include one slidable sleeve being sealed at its outer periphery and forming a valve seat at the one end surface, that the shanks of the control pistons penetrate each of the sleeves with clearance and have a valve plate at its end portion, that the one sleeve is synchronized with the compensating piston and that a stop is provided for fixing the rest position of the other sleeve.
The control piston has a comparatively small diameter in this construction, since it does not have to incorporate any valve components in its inside. Due to the smaller cross section, it is possible to operate the device with a lower amount of control force than heretofore. Therefore, a less powerful and-with regard to the manufacturing tolerances-less exact spring may be employed, or a smaller lever transmission is sufficient. Both solutions result in a reduced space requirement. The diameter to be sealed is comparatively small, the friction forces which have to be overcome upon a displacement are correspondingly insignificant. Thereby a very precise operation of the control piston is achieved. The sleeve bearing the valve seat is freely accessible at its periphery. It is, therefore, not difficult to couple the one sleeve with the compensating piston. Valve closure springs are not required. This avoids in addition the occurrence of the reactive effect of such a spring on the compensating piston.
Advantageously, the compensating piston is of a larger outside diameter than the sleeve. It is thereby accomplished that even slightest differences in the outlet pressure cause a sufficiently great force to displace the associated sleeve.
Favorably, the compensating piston and the associated sleeve are coaxially arranged in tandem and are rigidly connected to each other by means of a bridge extending over the valve plate cooperating therewith. With the aid of the bridge, the sleeve may be loaded axially from the compensating piston despite the existence of the valve plate.
For the resetting of the sleeve, the control piston advantageously includes a shoulder which is able to act upon an end surface of the sleeve remote from the valve seat. Since the control pistons are reset by the control force and entrain the sleeve, no separate return spring is required for the sleeve. The advantage is that the compensating piston is able to displace the sleeve without having to overcome a spring force, thereby rendering possible a still more precise pressure balance.
For fixing the rest position of the other sleeve, a stop formed in the housing may cooperate with a step at the outer periphery of the sleeve. This results in a particularly simple construction.
In a dual-circuit pressure control valve with unsymmetrical construction, slight differences in the control behavior of the valves cannot be avoided completely, and, moreover, the control valve assigned to the compensating piston has to close first. It is, therefore, particularly expedient to have the compensating piston act on a distribution device which will influence both control valves at the same time, but in an opposite sense in the event of an actuation.
This distribution device results in both control pistons and both control valves operating completely equally in status. There is no need for a lost motion for the one control piston. If the control valves include locking springs, the effect of these springs will be equalized by each other. The desired like pressure in both outlet chambers is achieved quickly in each case by the opposing influence on the two control valves. In addition to this, the components are accommodated symmetrically in the housing so that a simpler and more compact construction is achieved.
According to a preferred embodiment, the distribution device comprises a distribution element which is slidably arranged transversely to the axes of the two control pistons and each includes an inclined surface to additionally govern a control valve with the inclined surfaces being oppositely sloped relative to each other. This leads to a very simple construction of the distribution element and permits a space-saving construction in comparison with tiltable distribution elements or the like.
In particular, the compensating piston and the distribution element may be integrally formed. This combination saves component parts. Since the compensating piston is situated transversely to the control pistons, a housing is obtained which has a short length in direction of the control pistons' axes.
When using a cylindrical compensating piston, the compensation piston is provided with conical inclined surfaces close to its end portions.
It is, moreover, favorable to have a transmission piston seated on the inclined surface, which transmission piston is guided on the same axis with the associated control piston in the housing and acts on the control valve. This transmission piston ensures that the valve closure member is not loaded in the transverse direction on account of friction between the inclined surface and a valve tappet.
In another development of the present structure, an auxiliary inclined surface being oppositely sloped can join the outer ends of each inclined surface. In particular, the inclined surface and the auxiliary inclined surface can form a double cone. The auxiliary inclined surface enables, upon failure of the one circuit, the control valve of the other circuit to be urged compulsorily to the open position so that in this circuit the outlet pressure follows the inlet pressure even in the case of higher values. In this arrangement, the remaining stroke of the stepped piston is desired to be only somewhat greater than the closure travel of the valve.
Besides, a differential pressure indicating device can be provided, whose actuating element engages in a groove in the piston portion between the inclined surfaces. The groove requires including the seals on both sides of a specific axial length of the compensating piston. Since the compensating piston is no longer permitted to be arranged in axial prolongation of the one control piston but transversely thereto, it is not difficult to construct the compensating piston with this specific length.
BRIEF DESCRIPTION OF THE DRAWING
Above-mentioned and other features and objects of this invention will become more apparent by reference to the following description taken in conjunction with the accompanying drawing, in which:
FIG. 1 is a longitudinal cross-sectional view of a first embodiment of a dual-circuit pressure control valve in accordance with the principles of the present invention;
FIG. 2 is a longitudinal cross-sectional view taken along the line II--II of FIG. 1;
FIG. 3 is a longitudinal cross-sectional view of a second embodiment of a dual-circuit pressure control valve in accordance with the principles of the present invention;
FIG. 4 is a longitudinal cross-sectional view of a third embodiment of a dual-circuit pressure control valve in accordance with the principles of the present invention;
FIG. 5 is a longitudinal cross-sectional view of a fourth embodiment of a dual-circuit pressure control valve in accordance with the principles of the present invention; and
FIG. 6 illustrates a variant of the embodiment of FIG. 5.
DESCRIPTION OF THE PREFERRED EMBODIMENTS
In FIG. 1, a housing 1 accommodates two parallel, stepped bores 2 and 2' in which the control valves are disposed. Since the two control valves are substantially alike, the valves will not be described separately in the following; however, the valve components will be assigned the reference numerals of both devices. Slight differences will be pointed at where need be.
A sleeve 3,3' is arranged in the enlarged bore portion of bore 2,2' and sealed relative to housing 1 by means of a sealing ring 4,4'. Sleeve 3,3' abuts a first shoulder 5,5' of housing 1 and is secured against axial displacement by means of a ring 6,6' fastened in the housing 1. Located in each bore 2,2' is a stepped piston 7,7' which is guided by its larger diameter portion in bore 2,2' and with its smaller diameter portion in sleeve 3,3' and which is sealed by seals 8,8' and 9,9'.
An inlet chamber 10,10' is bounded by an annular surface between the steps of stepped piston 7,7' and an outlet chamber 11,11' by the end surface of the larger diameter portion of stepped piston 7,7'. A radial bore 12,12' and a coaxial fluid passageway 13,13' in the inside of stepped piston 7,7' connects inlet chamber 10,10' to outlet chamber 11,11'. Disposed in fluid passageway 13,13' is a valve closure member 14,14' being loaded against a valve seat 16,16' by a spring 15,15'. Valve closure member 14,14' accommodates a tappet 17,17' projecting from stepped piston 7,7'.
Arranged in an extension of bore 2 tapered in its diameter is a piston 18 which is sealed relative to housing 1 by means of two seals 19 and 20. Piston 18 defines with its end surfaces, being of equal size, outlet chamber 11, on the one hand, and a pressure chamber 21, on the other hand. Pressure chamber 21 communicates with outlet chamber 11' via a pressure fluid channel 22. The end portion of piston 18 close to outlet chamber 11 is radially enlarged in the form of a collar 23, with collar 23 being disposed between a second shoulder 24 of housing 1 and a stop ring 25 fastened in housing 1. Piston 18 is displaceable within limits, with its respective end position being defined by shoulder 24 and stop ring 25.
Tappet 17 of valve closure member 14 projecting from stepped piston 7 bears against collar 23, and tappet 17' of valve closure member 14' projecting from stepped piston 7' bears against the bottom of bore 2'. Because of this, both control valves are opened in the inactivated position of the device.
Secured to housing 1 by means of a pivot 26 is a lever 27 which is adapted to swivel around the longitudinal axis of pivot 26. Lever 27 bears against one end of one of stepped pistons 7,7' in the inactivated position of the device. At its point lying opposite the end of piston 7, lever 27 includes a threaded portion 30 in which an adjusting screw 31 is accommodated. In the embodiment shown, the piston end of stepped piston 7 has a clearance relative to adjusting screw 31, which is smaller than the valve closure travel and whose significance will be described below when the operation of the device is described.
A longitudinal cross section taken along the line II--II in FIG. 1 is shown in FIG. 2. The reference numerals of the individual elements correspond to those in FIG. 1. From FIG. 2, the moving ability of lever 27 can be clearly seen, and that a force designated F acts on lever 27. Force F is variable and serves as a control force of valve pistons 7,7'. In addition, FIG. 2 shows the pressure fluid ports leading to the master cylinder Hz and the wheel cylinder Rz.
The mode of operation of the braking pressure control unit illustrated in FIGS. 1 and 2 will be first described assuming that both brake circuits are operable. In the inactivated position of the device, the movable parts will be positioned as illustrated with the exception that stepped piston 7 abuts adjusting screw 31 and clearance a is situated between collar 23 and housing shoulder 24. Closure members 14,14' of the control valves are opened in this position.
When the brake is actuated, the pressure fluid in both brake circuits will first of all be allowed to flow unhindered from the master cylinder Hz to the wheel cylinders Rz. Acting in each case on the stepped pistons 7,7', due to different sized pressurized surfaces, is a differential of force which causes a movement of stepped pistons 7,7' in opposition to lever 27 and control force F acting thereupon.
Since the closure travel of the valve 14,16 is reduced by the amount of the clearance a, it will be valve closure member 14 that closes fluid passageway 13 first by abutting the valve seat 16 after the remaining closure travel has been overcome. The other valve 14',16', the closure travel of which is not reduced by the amount of the clearance a, will be still open in the event of the same displacement travel of both stepped pistons 7,7', and the pressure build-up will thus be continued undiminished in the associated brake circuit. Due to the slight difference in pressure occurring in outlet chambers 11 and 11', a resultant force will act on piston 18 and displace piston 18 in the direction of stepped piston 7. Thereby, collar 23 acts upon tappet 17 and lifts valve closure member 14 from its valve seat 16. As a result, additional pressure fluid is supplied to outlet chamber 11 until the same pressure prevails there as in outlet chamber 11'. This compensation procedure will be repeated, if necessary, until stepped piston 7', too, has overcome the closure travel of valve 14',16'.
A further pressure increase on the inlet side results in a reduced pressure increase on the outlet side, with the pressures in the outlet chambers 11,11' being always of equal amount due to the compensating effect of piston 18. The pressure level, at which the reducing effect of the control valves occurs, is dependent on the magnitude of control force F which may be fixedly set or may be variable.
When the pressure is decreased on the inlet side, valve closure members 14,14' will be lifted from valve seats 16,16' on account of the pressure still prevailing on the outlet side causing the pressure being decreased there, too. Control force F causes stepped pistons 7 and 7' to move back to their inactive positions, with stepped piston 7' moving in abutment with the end surface of housing 1 and the clearance a being maintained between the housing shoulder 24 and collar 23.
If one of the brake circuits fails due to a defect, stepped piston 7,7' of the still intact brake circuit will have to overcome the entire control force F prior to the reducing effect of the valve taking place. The changeover pressure of the valve will be increased to double the value. For providing the volume input of the still intact brake circuit to be increased only slightly upon failure of a circuit, the displacement travel of piston 18 is bounded by shoulder 24 of housing 1 and stop ring 25.
The embodiment shown in FIG. 3 distinguishes from the embodiment of FIG. 1 merely in that piston 7 includes a step 28 close to its end portion projecting from housing 1 and a spring 29 having one end bearing against step 28 and its other end acting on lever 27. An adjusting screw, as is illustrated in FIGS. 1 and 2, can also be included in this arrangement. In principle, spring 29 could be inserted in a different place. However, in the illustrated device it affords the advantage of having no detrimental effects (for example, in the form of a pressure difference in the outlet chambers 11 and 11').
The braking pressure control unit in accordance with FIG. 3 corresponds in its mode of operation with the preceding description referring to FIGS. 1 and 2. However, when the device is depressurized, spring 29 always causes stepped piston 7 to move to its end position closed to outlet chamber 11.
In the embodiment of FIG. 4, two parallel stepped bores 52 and 52' are provided in a housing 51. Located in bore 52 is a control valve 53 and a compensating piston 54 and located in bore 52' is a control valve 53'.
Control valve 53 includes a sleeve 55 forming a valve seat 56 at one end surface thereof. Sleeve 55 is sealed at its outside by means of a seal 57 which is held between a guide ring 58 and a prop ring 59. A control piston 60 includes a valve plate 61, a shank portion 62 of smaller diameter penetrating sleeve 55 and a shaft portion 63 of greater diameter leading outwardly and surrounded by a seal 64. Seal 64 is arranged in an inset 65 which is held between prop ring 59 and a circlip 66. Valve plate 61 includes an elastic closure element 67 which is held by a sheet metal top 68 forming a guide flange at the same time. Control valve 53 separates an inlet chamber 69 communicating with a port Hz of a tandem master cylinder from an outlet chamber 70 connected to at least one wheel cylinder Rz. A step 71 between shank portions 62 and 63 cooperates with the end surface 72 of sleeve 55 in order to entrain sleeve 55 to the left-hand position. Notches 73 permit fluid flow in this position.
The compensating piston 54 is provided with two seals 74 and 75. A bridge 76 connects compensating piston 54 to sleeve 55. Bridge 76 is permeable to liquid. For example, bridge 76 may be welded annularly with the end surface of compensating piston 54 and may engage with resilient ribs in an annular groove of sleeve 55. Compensating piston 54 is located between outlet chamber 70 and a pressure chamber 77, the latter being connected via a bore 78 with outlet chamber 70' of control valve 53'. The movement of the compensating piston is limited to the right by a circlip 79 and to the left by an end surface 80 of housing 51.
Control valve 53' is of the same construction as control valve 53. Therefore, like parts are assigned like reference numerals, however, marked with an apostrophe. In this arrangement, the inlet chamber 69' is connected with a second port Hz' of a tandem master cylinder. The outlet chamber 70' leads to at least one other wheel cylinder Rz'. In addition, provided in the guide ring 58' is a stop 81 which cooperates with a step 82 at sleeve 55'. Acting on the end surfaces of both control pistons 60 and 60' leading out of housing 51 is a lever 83 which is adapted to swivel around pivots 84 and, located outside the drawing plane, to be loaded by a control force F. Force F may be constant or responsive to the vehicle load.
In normal operation, the arrangement illustrated in FIG. 4 operates as follows:
With pressure fluid subjected to increasing pressure being fed to the two inlet chambers 69,69', the pressure in the outlet chambers 70,70' rises in the same manner. When the inlet pressure in each brake circuit multiplied by the surface Q2 exceeds half the control force F, both control valves 53,53' will close. Thereupon, a rise of the outlet pressure will occur, said rise being reduced with reference to the rise of the inlet pressure according to the relation ##EQU1## In the event of control valve 53 closing prior to control valve 53', a higher pressure will develop in outlet chamber 70' and thus in pressure chamber 77 causing compensating piston 54 with sleeve 55 to be displaced to the right in the drawing so that control valve 53 opens anew until a pressure balance prevails in both outlet chambers 70,70'. In the event of control valve 53' closing first, compensating piston 54 and sleeve 55 will be moved to the left in the drawing so that control valve 53 closes as well. If the inlet pressure is decreased, control pistons 60,60' will return to the drawn initial position under the influence of the control force F. In doing so, pistons 60,60' entrain sleeves 55,55' via the step 71,71'. The backstroke is terminated when step 82 of sleeve 55' abuts stop 81. The inactivated position of the system is defined this way.
When one brake circuit fails, the associated control piston remains in its rest position. The other control piston will then be loaded with the full control force F resulting in the change-over pressure of the valve being increased to double the value, which is desired in such cases.
In FIG. 5, two like control valves are accommodated in a housing 101, one of which will be described. The other control valve is assigned like reference numerals, however, marked with an apostrophe.
A stepped bore 102 is provided in its enlarged bore portion with a sleeve 103 which is sealed relative to housing 101 by means of a sealing ring 104. Sleeve 103 bears against a first shoulder 105 of housing 101 and is located against axial displacement by means of a ring 106 which is fastened in housing 101. A stepped piston 107 is guided with its larger diameter portion in bore 102 and with its smaller diameter portion in sleeve 103 and sealed by means of seals 108 and 109.
An inlet chamber 110 is defined by an annular surface between the larger and the smaller diameter portions of stepped piston 107 and an outlet chamber 111 is defined by the end surface of the larger diameter portion of stepped piston 107. Inlet chamber 110 and outlet chamber 111 communicate with each other via a radial bore 112 and a coaxial pressure fluid passageway 113 on the inside of stepped piston 107. Situated in pressure fluid passageway 113 is a valve closure member 114, which is loaded by a spring 115 against a valve seat 116. Valve closure member 114 includes a tappet 117 extending from stepped piston 107.
A compensating piston 118 which is sealed relative to housing 101 by means of two seals 119 and 120 is arranged in a transverse bore 121, bore 121 being closed by a plug 122 which is sealed relative to housing 101 by means of a seal 123 and which is fastened by means of a circlip 124. Compensating piston 118 is integrally formed with a distribution element which includes in this case two cones 125 and 126 whose inclined surfaces 127 and 128 are oppositely sloped with respect to each other. Seated on cones 125 and 126 are transmission pistons 129 and 130 which are guided in bores 131 and 132 by means of ribs. Via the channels remaining between the ribs, outlet chamber 111 is connected to the pressure chamber 133 on the one side of compensating piston 118, and outlet chamber 111' is connected to the pressure chamber 134 on the other side of compensating piston 118. Pressure chambers 133 and 134, on their part, communicate with ports 135 and 136, to which ports lines leading to wheel cylinders Rz and Rz' are connectible. The inlet chambers 110,110' are connected with two outlets Hz and HZ' of a tandem master cylinder.
A preloading force F acts on a lever 137 which is pivotable around two pivots 138 and 139 which are displaced from the drawing plane. Force F can be constant or vary load-responsively.
The mode of operation of the dual-circuit pressure control valve illustrated in FIG. 5 will first be described assuming that both brake circuits are operable. The two stepped pistons 107,107' bear with their end surface against the left-hand step of bores 102,102' in the rest position such that valves 114, 116 and 114', 116' are open. When the pressure increases at the inlet Hz,Hz', the pressure at the outlet Rz,Rz' will follow in the same way, since the two control valves 114,116 and 114',116' are open. With increasing pressure, the stepped pistons 107,107' will move to the right in the drawing, until the aforementioned valves finally close. In case one control valve 114,116 closes earlier than the other control valve 114',116', the pressure in the pressure chamber 134 will rise higher than the one in the pressure chamber 133, and the compensating piston 118 moves downwards. As a result, transmission piston 130 and, thus, tappet 117 will be shifted to the right in the drawing by means of inclined surface 128 so that control valve 114,116 opens again. At the same time, valve closure member 114' and transmission piston 131 will be displaced to the left in the drawing by locking spring 115' because inclined surface 127 offers the respective space therefor. Control valve 114',116' will be, therefore, moved in the closing direction. Due to this oppositely directed movement, both control valves will be closed approximately simultaneously and, for this reason, at the same pressure. With the inlet pressure continuing to rise, the outlet pressure follows along a characteristic curve with a reduced slope. If the control valve 114',116' had closed first, compensating piston 118 would have been moved upwards so that control valve 114',116' would have opened again and the other control valve 114,116 would have been moved in the closing direction.
When one brake circuit fails, compensating piston 118 will move to the stop provided by plug 122 or the stop provided by the oppositely disposed end surface of transverse bore 121, and the control valve of the operable brake circuit will function as usual. The valve will, however, close after a shorter travel of piston 107,107' and against an increased force because the preloading force F is no longer distributed onto the two pistons. In total, the changeover pressure of the intact valve will, therefore, be increased when a circuit fails.
It is, however, frequently desired in the event of failure of the one brake circuit to keep the outlet pressure of the other brake circuit always at the same level as the inlet pressure. This may be achieved by the embodiment according to FIG. 6.
In FIG. 6, like parts are assigned like reference numerals as in FIG. 5, increased by 100. In this structure, adjoining the two cones 225,226 with their inclined surfaces 227,228 are auxiliary cones 240,241 with oppositely sloped inclined surfaces 242,243, respectively. When the compensating piston 218 is urged into the one end position upon failure of the one brake circuit, these inclined surfaces cause the transmission piston 230,231 to be pressed completely to the right in the drawing of FIG. 5, and, by this means, to constantly keep open the pertinent control valve 114,116 or 114',116'. To the end that this is accomplished for sure, the maximum displacement travel of piston 107--as shown in FIG. 5--which always has to be greater than the closure travel of the valve 114,116, is smaller than the sum of the displacement travel of the transmission piston 130 (in the case of piston 107', transmission piston 129 is meant) upon failure of a brake circuit plus the valve closure travel. Therefore, the wheel cylinders of the brake circuit in operation are supplied with the full inlet pressure over the entire range of pressure.
In addition, compensating piston 218 has a groove 244 between inclined surfaces 227 and 228, in which a tripping pin 245 of a differential pressure indicating device 246 engages. This groove 244 is of such an axial length that the compensating function of compensating piston 218 is possible in the range of the usual pressure differentials of the inlet pressures without actuating the differential pressure indicating device 246. After a predetermined travel, compensating piston 218 with its end surface 247 will be in operative connection via a spring plate 248 with a spring 249, or with a circlip 250 via a spring plate 251 with spring 249. As soon as the differential of pressure between the two brake systems acting on compensating piston 218 exceeds the preload of spring 249, tripping pin 245 is moved by groove 244 outwardly so that a switching operation occurs which provides an indication.
The compensating piston is likewise able to act on a distribution device separated therefrom. The distribution device may, for instance, be composed of a lever which is tiltable around a point of rotation arranged between the two stepped pistons' axes. The inventive principle can be used in connection with control valves of different design as well.
While we have described above the principles of our invention in connection with specific apparatus, it is to be clearly understood that this description is made only by way of example and not as a limitation to the scope of our invention as set forth in the objects thereof and in the accompanying claims.
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Dual-circuit pressure control valves are known in which the control pistons are acted upon by a common control force. A preload distributor constructed as beams of balance to compensate for differences in the control behavior of the two control valves due to manufacturing tolerances have not provided the desired compensation. Therefore, according to the present invention an improved compensation arrangement is provided in the form of a compensating piston which is subjected to the outlet pressures of the two brake circuits.
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This application is a continuation of U.S. Ser. No. 08/410,657 filed Mar. 24, 1995 now U.S. Pat. No. 5,512,477 which is a continuation of U.S. Ser. No. 08/230,933 filed Apr. 21, 1994, abandoned.
BACKGROUND OF THE INVENTION
Since the development of the in vitro cultivation of mammalian cells the demand for large scale production of these cells has increased due to diagnostic and therapeutic potential of many of the products they produce. These useful agents include monoclonal antibodies, human growth hormone, lymphokines, erythropoietin, blood clotting factors and tissue plasminogen activators.
For many of these cellular agents mammalian cell culture provides the only viable production source. Mammalian cells have the capability to synthesize such agents with the proper configuration, correct disulfide bonding, and arrays of sugar side chains, all of which result in the desired activity of the naturally occurring agent. Therefore, many agents derived from mammalian cells are more likely to be efficacious and are less likely to be immunogenic in target mammals if expressed by bacterial or yeast fermentation.
To improve productivity, many medium formulations for feeding of mammalian cultures have been suggested (Fike et al., BioPharm. Oct.: 49-54, 1993). Some suggested medium formulations using unconcentrated nutrients significantly increase the final culture volume and thus complicate the production and recovery process (Reuveny et al. Develop. Biol. Standard 60:185-197, 1985).
Feeding with concentrated nutrients (i.e., supplements) is the preferred in vitro cultivation strategy because the product can be recovered more economically from a smaller volume of liquid, i.e., more concentrated. Methods of supplementation involve either boosting the concentration of nutrients in a basal formulation or feeding the culture with supplements. There have been only a few reports on such feeding strategies (Jo E. C. et al., UK Patent Application #2251249A, 1992; Jo E. C. et al., Biotechnol. & Bioeng. 42:1229-1237, 1993; Luan Y. T., Biotechnol. Letters 9:691:696, 1987). However, serum has to be present in the feeding media which complicates subsequent purification procedures and increases production costs.
A need exists to develop a low-cost, serum-free supplement for use in mammalian cell cultures.
SUMMARY OF THE INVENTION
This invention relates to a serum-free eukaryotic cell culture medium supplement. The supplement comprises carbon sources, vitamins, inorganic salts, amino acids and a protein digest.
The medium supplement of the present invention enables the maintenance of mammalian cell cultures at cell densities equal to or greater than that obtained with batch culture methods while increasing longevity and productivity.
BRIEF DESCRIPTION OF THE DRAWINGS
FIG. 1 shows a graph illustrating the monoclonal antibody production and cell density of one hybridoma cell line when fed with the medium supplement of the present invention versus the same culture without supplementation.
FIG. 2 shows a graph of the final monoclonal antibody production of 16 different hybridomas using fed-batch method of cell culture with the medium supplement of the present invention versus that achieved through batch culture (i.e., without supplement feeding)
FIG. 3 shows a graph of the maximum viable cell number of the 16 hybridomas in the fed-batch mode with supplementation using the medium supplement of the present invention versus the batch method of cell culture.
FIG. 4 shows a graph of the longevity of the 16 hybridomas in the fed-batch mode with the medium supplement of the present invention versus batch method.
DETAILED DESCRIPTION OF THE INVENTION
This invention is based upon the discovery of a serum-free medium supplement which can be used to maintain a eukaryotic cell line in culture. The supplement comprises carbon sources, vitamins, inorganic salts, amino acids and a protein digest.
By the use of the term "supplement" what is intended is a buffered solution containing a concentrated amount of nutrients which when added to an in vitro eukaryotic cell line, maintains viability. The supplement of the present invention can be added to an in vitro eukaryotic cell culture medium without the need to remove old or spent medium.
The term "batch mode of cell culture" as used herein describes a method of culturing cells where cells are seeded into a cell culture vessel containing an initial volume of nutrient medium (such as Dulbecco's Modified Eagles Medium (DMEM) with 10% fetal bovine serum (FBS) or Protein-Free Hybridoma Medium (PFHM-II), wherein the initial volume of nutrient medium is not replenished with any medium.
The term "fed-batch mode of cell culture" as used herein describes a method of culturing cells where cells are seeded into a cell culture vessel containing an initial volume of nutrient medium and where supplements are added to the medium in a continuous or semi-continous manner.
The medium of the present invention includes a carbon source. Suitable carbon sources include L-glutamine and D-glucose. A carbon source containing L-glutamine in a concentration of about 7.3 grams per liter (g/L) and D-glucose in a concentration of 25 g/L are preferred.
The medium of the present invention, in addition, comprises vitamins. Suitable vitamins include a biotin, choline chloride, a folic acid, an inositol, a niacinamide, benzoic acid, a pantothenic acid, a pyridoxine, a riboflavin, a thiamine and B vitamin or mixture thereof. A mixture containing the vitamins listed in Table 1 below is preferred.
TABLE 1______________________________________VITAMINSVitamins g/L______________________________________D-Biotin 0.005Choline Chloride 0.075Folic Acid 0.025myo-Inosito1 0.875Niacinamide 0.025p-Amino Benzoic Acid 0.025D-Pantothenic Acid 0.00625(hemicalcium)Pyridoxine HCl 0.025Riboflavin 0.005Thiamine HCl 0.025Vitamin B12 0.000125______________________________________
Furthermore, the medium of the present invention comprises inorganic salts. Suitable inorganic salts include potassium chloride, potassium phosphate, sodium chloride and sodium phosphate or a mixture. A mixture containing the inorganic salts listed in Table 2 below is preferred.
TABLE 2______________________________________INORGANIC SALT MIXTUREInorganic Salts g/L______________________________________Potassium Chloride 0.05Potassium Phosphate 0.05Monobasic (anhydrous)Sodium Chloride 2.0Sodium Phosphate Dibasic 0.2(anhydrous)______________________________________
The medium of the present invention, further comprises amino acids. Suitable amino acids include alanine, arginine, asparagine, aspartic acid, cystine, glutamic acid, glycine, histidine, proline, isoleucine, lysine, methionine, serine, threonine, trytophan, tyrosine and valine or a mixture thereof. A mixture containing the amino acids listed in Table 3 below is preferred.
TABLE 3______________________________________AMINO ACID MIXTUREAmino Acids g/L______________________________________L-Arginine (free base) 2.5L-Asparagine hydrous) 0.625L-Aspartic Acid 0.25L-Cystine 0.625L-Glutamic Acid 0.25Glycine 0.125L-Histidine (free base) 0.1875Hydroxy-L-Proline 0.25L-Isoleucine 0.625L-Lysine-HC1 0.5L-Methionine 0.1875L-Phenylalanine 0.1875L-Proline 0.25L-Serine 0.375L-Threonine 0.25L-Trytophan 0.0625L-Tyrosine-2Na2H.sub.2 O 0.3604L-Valine 0.25______________________________________
In addition, the medium of the present invention comprises a protein digest. Suitable protein digests include PRIMATONE CLT™ an enzymatic digestion of meat (or meat digest), manufactured by Sheffield Products of Norwich, N.Y., casein or enzymatic hydrolysates. In a preferred embodiment the medium comprises PRIMATONE RL™ meat digest (Sheffield Products) in the amount of 25 g/L of the water component of the medium.
Exemplification
Material and Method:
Maintenance, Expansion and Feeding of Cultures
Frozen hybridoma cells (16 distinct cell lines) were thawed quickly at 37° C. and transferred into DMEM (Gibco, Grand Island N.Y.) with 10% FBS (Hyclone Laboratories Inc., Logan Utah) or PFHM-II (Gibco) and grown in t-flasks. The cells were maintained in the t-flasks at 37°±1° C. and 5-10% CO 2 until the cultures reached 40-70% maximum viable density.
The cells were then expanded into 1, 2, or 8-L spinner flasks with a starting viable cell density of at least 0.1-0.2 million/ml as determined by hemocytometer and trypan blue staining. The 1-L and 3-L flasks were maintained at 37±1 C. and agitated at 50-80 rpm (stir bar) with an overlay of mixed gas (5% CO 2 , 20-40% O 2 , balance N 2 ) at 10-20 ml/min/L. The 8-10-L flasks were agitated at 50 rpm with overhead drive and overlaid with the same gas mixture at 10-20 ml/min/L. The cultures were monitored daily as to total cell number, viable cell number, cell viability, monoclonal antibody concentration, glucose concentration, ammonia concentration, and lactate concentration.
When the viable cell density reached 50%±20% of peak density, 20 ml/L of the serum-free medium supplement, components of which are shown in Table 4 below, were added to the culture.
TABLE 4______________________________________Serum-Free Medium SupplementComponent g/L______________________________________L-Glutamine 7.3D-Glucose 25.0vitamin mixture (Table 1) 1.0914inorganic salt mixture (Table 2) 2.3875amino acid mixture (Table 3) 7.8829PRIMATONE RL ™ 25.0purchased fromSheffield Products)______________________________________
Feeding was continued daily and D-glucose was maintained above 1 g/L (45% D-glucose solution) until the viable cell density had dropped below 0.3 million/ml. The culture was harvested, the cells removed, and the product purified from the culture with the appropriate purification procedure.
Viable Cell Count
A 0.5 to 1.0 ml sample of the culture was aseptically removed from the culture in a laminar flow hood and placed in a microfuge tube.
The cell suspension was diluted with Trypan blue/PBS (0.4%) and mix thoroughly. A cover slip was placed on a hemocytometer and a small amount of the cell mixture placed into the chambers. The chambers were allowed to be filled by capillary action. The hemocytometer was viewed under a microscope under 10×10 power and cells in all 8 of the outer boxes were counted and recorded. Both viable (clear white) and non-viable (blue) cells were counted. ##EQU1## ELISA assay
Wells in polystyrene plates (cat #25801-96 high-binding flat bottom, Corning, Corning, N.Y.) were coated with 100 μl of Goat anti-mouse IgG (H+L) (Cat #115-005-003, Jackson ImmunoResearch, West Grove, Pa.), 1:200 dilution into 0.1M sodium carbonate pH 9.0, overnight at 4° C. After the overnight incubation, the liquid was removed and the plate was washed four times with phosphate buffered saline (PBS) pH 7.4 containing 0.05% Tween 20. The wells were filled with 200 μl of 2% Bovine Serum Albumin (BSA) solution in PBS to block residual binding sites. After 30 minutes incubation at room temperature (RT), the blocking reagent was removed and 100 μl of the diluted culture supernatant (PBS containing 0.05% Tween 20 and 0.5% BSA diluant) or standard antibody preparation (0 to 20 ng/ml) was added to each well. After 30 minutes incubation at RT, the plate was washed four times with the washing solution and 100 μl of peroxidase conjugated Goat anti-mouse IgG (cat #115-035-062, Jackson ImmunoResearch) diluted 1:2000 in PBS containing 0.05% Tween 20 and 0.5% BSA was added to each well. After 30 minutes incubation at RT, the plate was washed four times with the washing solution and 100 μl of OPD substrate (Cat #CIN4905/CIN4805, Medix Biotech, Inc. Foster City, Calif.) was added to each well. After 5 minutes incubation at RT, 100 μl 0.2N Sulfuric Acid was added to each well. Absorbance at 492 nm was measured in an ELISA reader and concentrations determined from the linear standard curve.
Glucose, lactate, and ammonium analysis
Glucose, lactate, and ammonium concentrations in culture samples were measured by an IBI Biolyzer (International Biotechnologies, Inc., New Haven, Conn.) following the directions provided.
Equivalents
Those skilled in the art will recognize, or be able to ascertain, using no more than routine experimentation many equivalents to the specific embodiments of the invention described herein. Such equivalents are intended to be encompassed by the following claims:
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This invention relates to a serum-free eukaryotic cell culture medium supplement. The supplement comprises carbon sources, vitamins, inorganic salts, amino acids and a protein digest.
The medium supplement of the present invention enables the maintenance of mammalian cell cultures at cell densities equal to or greater than that obtained with batch culture methods while increasing longevity and productivity.
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BACKGROUND OF THE INVENTION
The tubes in the primary loops of steam generators of nuclear reactors are subjected to high temperatures and pressures, radioactive bombardment, and attack by corrosive materials carried in the steam that passes through them. As a result, they frequently bend or deform from a straight or linear configuration. Because deformation usually precedes failure, it is necessary to periodically ascertain the deformation of these tubes so that dangerously deformed tubes can be plugged or replaced. In order to rationally decide how likely a deformed tube is to fail, one must know not only how much the tube is deformed, but also where along the tube the deformation occurs, as well as its direction.
Since the tubes are not visible or otherwise accessible from the outside, this information must be obtained by examining the inside of the tubes. The examination must be as precise as possible, of course, for otherwise tubes in acceptable condition will be unnecessarily plugged or replaced, or worse, a defective tube will not be detected and conceivably could fail, permitting contaminated water to enter the secondary loop. The problem is difficult because the tubes, of which there may be several thousands, are vertical, and can be only 1/4 to 1 inch in inside diameter, yet longer than 15 feet. In addition, the area where the examination must be performed is highly radioactive, so the examination must be done as quickly as possible to reduce radiation exposure to humans.
SUMMARY OF THE INVENTION
I have invented a probe, which, when driven through a confined passage, or over a surface, will provide electrical signals that are proportional to the deformation of the passage or surface from linearity. Two of these electrical signals can independently indicate the amount of bending in directions that are at right angles, and therefore the amount of bending in any direction can be determined. The apparatus of this invention can also precisely measure the position of deformations along tubes, and the direction of the deformations.
Moreover, when the apparatus is used to examine the tubes in a steam generator of a nuclear reactor, very little human exposure time to radiation is required because the apparatus can be quickly attached to the bank of tubes in the steam generator at the tube sheet. Once attached, no human manipulation or control in the highly radioactive area of the steam generator is required to operate the apparatus.
DESCRIPTION OF THE INVENTION
FIG. 1 is an isometric view partially in section illustrating a certain presently preferred embodiment of a probe according to this invention.
FIG. 2 is a side view in section illustrating a portion of the probe shown in FIG. 1.
FIG. 3 is a side view in section illustrating another embodiment of a portion of the probe shown in FIG. 1.
FIG. 4 is a side view in section illustrating still another embodiment of a portion of the probe shown in FIG. 1.
FIG. 5 is an isometric view illustrating another embodiment of a portion of a probe according to this invention.
FIG. 6 is a side view, partially in section, illustrating a certain presently preferred embodiment of an apparatus for driving a probe according to this invention.
FIG. 7 is a side view, partially in section, illustrating another embodiment of an apparatus for driving a probe according to this invention.
In FIGS. 1 and 2, a probe 1 in tube 2, consists of an elongated member 3 which is composed of sections 4, 5, 6, 7, and 8. Sections 4, 6, and 8 are rigid or are equally flexible in all directions, or are equally flexible in two directions that are perpendicular to the longitudinal axis 9 of tube 2 and of member 3. Sections 5 and 7 are more flexible than sections 4, 6, and 8, although sections 4, 6, and 8 should also be somewhat flexible, for otherwise the probe may become stuck in sharp bends, or its usefulness will be limited to channels of limited deformation. Sections 5 and 7 are more easily flexed around axes 10 and 11, respectively, which are at right angles, and are also at right angles to axis 9. The increased flexibility of sections 5 and 7 over sections 4, 6, and 8 is due to the constriction of member 3 at these sections, where indentations from each side of member 3 insure that sections 5 and 7 will bend along axes 10 and 11, respectively, before sections 4, 6, and 8 will bend in those directions. In directions that are normal to those directions, however, sections 5 and 7 are about as inflexible as are sections 4, 6, and 8.
Mounted on the flexing surfaces of sections 5 and 7 are strain sensors 12 and 13, respectively. Similar strain sensors (only strain sensor 12a is shown) are mounted on the opposite sides of these surfaces. These strain sensors generate an electrical signal that is proportional to the amount that these surfaces are flexed. Wires 14 carry this current from the probe through wand 15 to apparatus (not shown) for analyzing these signals. Coiled over member 3 in contact therewith is a spring 16 which tends to restore member 3 to a linear configuration whenever it is deformed from linearity by the walls of tube 2. An elastomeric material 17 encapsulates spring 16 to maintain a fixed relationship between member 3 and spring 16. A protective jacket 18 encloses elastomeric material 17 to reduce friction between the probe and the inside walls of tube 2. As probe 1 is driven along the walls of tube 2, any deviation in the walls of tube 2 from a straight line forces protective jacket 18 to bend the same amount, which, in turn, transmits the deformation to sensors 12 and/or 13.
In FIG. 3, capacitance type displacement sensing devices consisting of plate pairs 20 and 21, 22 and 23, and 24 and 25, and a pair opposite pair 24 and 25 (not shown), are mounted on the sides of sections 4, 6, and 8 of member 3, rather than on sections 5 and 7 as is shown in FIGS. 1 and 2.
FIG. 4 illustrates another variation, where linear variable differential transformers (LVDT) 31 and 32 are mounted between sections 4 and 6, and between sections 6 and 8 (not shown). Movements by sections 4 and 6 together or apart move iron cores 33 and 34 within coils 35 and 36 of LVDT's 31 and 32, respectively, generating electrical signals that are proportional to the amount of movement.
FIG. 5 illustrates a tubular member 40, where all sections of the member are equally flexible in all directions. Stress sensing devices 41, 42, and 43, and one opposite device 41 (not shown), are mounted on the outside of member 40.
FIG. 6 illustrates an apparatus for driving probe 1 into tube 2. One end of wand 15 is attached to a block 56 having a pin 51 which engages it with a chain belt 50. Chain belt 50 is driven by sprocket 52 which is coupled to motor 54. In addition to sprocket 52 the chain belt 50 is also supported by driven sproket 53 which is coupled to position encoder 55. As belt 50 moves, wand 15 is forced through a flexible conduit 57 which connects drive housing 58 with support plate 59 of the tube bundle of the steam generator. Although conduit 57 is flexible, it is made to resist torsional deformation. Conduit 57 is attached to drive housing 58 via a rotary coupling comprised of sleeve 64 and bearing 60 with gear 61 fixed to the sleeve 62. Gear 61 is coupled by another gear 62 to a rotary transducer 63 that indicates the position (twist) of the conduit at any point in time when the probe is inserted into the generator. This twist is then referenced to the arbitrary position of the drive housing 58 which is positioned in a known relationship to the support plate 59 of the tube bundle. The orientation of the probe is then determined by the azimuthal orientation of two other locating pins 65 and 66 inserted into two adjacent tubes. The two pins are tied together in a gripper block 67 fastened to the conduit in a pneumatically expanded elastic anchor 68. Pressurized air fed through tube 69 keeps the gripper block 67 in place during a measurement scan of a tube.
FIG. 7 illustrates an alternative apparatus for driving wand 15, where wand 15 is to attached by pin 70 to a rotating drum 71 and trapped in place by a series of idle rollers 72 surrounding the drum. This configuration allows a single or multiple wraps of the wand on the drum. Drum 71 is driven by motor 73 through gear 74. Gear 74 is also coupled to rotational transducer 75, so that the orientation of probe 1 in tube 2 can be determined as in FIG. 6.
Member 3 may be constructed in a variety of ways from many different materials. If it is desired to measure deformation in only one direction, the member would need to be flexible only in that direction. The member should be sufficiently resilient to "unflex" when the deforming force of the tube is lessened. This can be accomplished, for example, by choosing a resilient polymeric material such as nylon, rubber, or metallic materials such as spring steel, for the flexing portion of the member. While several different materials can be used in making the member, it is preferable to construct the member out of a single piece of resilient polymeric material, as shown in FIG. 1, because construction is simplified. Nylon is the preferred resilient polymeric material because it has about the right degree of strength, flexibility, and resiliency required for best performance. The tendency of a resilient member to return to its initial undisturbed shape when not forced to bend can be greatly enhanced by the addition of one or more helically wound springs surrounding it along its entire length. The member may be square, circular, polygonal, or of other cross-sectional shape, and can be solid or tubular. If the member has a more flexible portion, it should have at least two portions that contact the surface being examined, with the more flexible portion inbetween. Preferably, the member has three sections that contact the surface being examined, and two portions inbetween that flex in directions at right angles, so that deformations in all directions can be measured. However, when a plurality of sections is used the sequence repeats the above.
A variety of devices can be used to measure the bending of the member. Typical sensors include resistive strain gauges, piezoelectric crystal gauges, capacitance sensors, linear variable differential transformers, magnetic reluctance sensors, inductance sensors, capacitance sensors, and digitally encoded magnetic sensors. Resistive strain gauges are preferred as they are small, inexpensive, reliable, and have been found to work well. Each sensor is generally attached to the member at at least two points spaced apart along its longitudinal axis, with at least part of the flexing portion of the member inbetween; the sensor then detects the movement of these two points together and apart. It is preferable to use a redundant sensor on the opposite side of the flexing portion of the member, and to sum the results (taking direction of movement into account), to obtain a larger signal and a more precise measurement of the amount of deformation. The sensors can be mounted in a variety of ways, as shown in the drawings. The output of the sensor is preferably an electrical signal, although other types of signals, such as changes in air flow, light intensity, light reflection, or sound echo could also be used. An electrical signal output can be converted to observable form, by, for example, operating a magnet that moves a needle or a pen across moving paper. It is preferable, however, to analyze the signal with a computer, especially if there are sensors at right angles, so that the amount of deformation, direction of deformation, and position of deformation can be calculated and displayed in an easily understood form. For example, a graph can be drawn which gives the amount of incremental deformation (in the direction of maximum deformation) along the ordinate, and the position of the deformation along the abscissa. Computer programs for doing this are known and available.
If the surface itself does not confine the probe, then the means for driving the probe across the surface must include means for pressing the probe against the surface. For example, if the convolutions of a turbine blade are to be examined, the probe can be mounted on springs which ride over an opposing surface and press it against the turbine blade. A wand, which drives and retrieves the probe from a confined passage such as a channel, or a tube, is preferably made of a material, such as woven fiber or wire embedded in or covered with a low-friction elastomer, which will neither compress nor stretch in its elongated direction, so that the position of the probe in the tube can be determined, and which will not twist, so that the orientation of the probe within the tube can be determined. At the same time, however, the wand must, of course, be be sufficiently flexible to pass by whatever bends it encounters in the passage. It is also desirable that that the wand contain the wires from the pressure sensing devices mounted on the probe so that they do not become entangled or damaged.
The probe of this invention can be used to measure the deformation of any surface, including tubes, turbine blades, channels, nuclear fuel bundles, and filters. It is only necessary that the probe be pressed against the surface as it is driven across it, sufficiently for the flexing portion of the member to bend so that the probe conforms to the contours of the surface. The probe is especially useful, however, in measuring the deformation of tubes, such as the heat exchange tubes in the steam generators of nuclear reactors.
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Disclosed is an apparatus for measuring the deviation from a straight line of an elongated passage having opposing sides. The apparatus comprises a member sufficiently bendable and sufficiently large that it can pass through the passage in contact with both of the sides of the passage. Included is a means for measuring the amount that the member bends as it passes through the passage, means for moving the member through the passage between its opposing sides, and means to indicate, collect, and analyze the resultant electrical signals. The apparatus is most useful in measuring and locating deformations in the tubes of the steam generators of nuclear reactors.
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BACKGROUND OF THE INVENTION
1. Field of the Invention
This invention relates to a pneumatic screw aligner-feeder incorporating a screw feeder and a screw tightener.
2. Description of the Prior Art
Heretofore, there have been employed screw aligner-feeders consisting of separate screw tighteners and screw feeders which were coupled with hoses for passing screws. U.S. Pat. No. 4,114,663 falls under this category. Such a screw tightener installed separately from a screw feeder is, however, limited to the operating radius of the connecting hose.
U.S. Pat. No. 2,922,447 describes another screw aligner-feeder incorporating a screw tightener and a screw feeder. In this invention, however, screws are fed by gravity. The device is therefore useful only when used in an upright position.
A similar problem arises with the use of an aligner-feeder developed by the present inventors which is the subject of Japanese Pat. No. 31716/76. This device uses compressed air to stir screws in a container and to force them along an incline guide wall on the bottom of the container, forcing the screw to an upper output in a desired orientation.
Since the inclined guide wall is installed on the bottom of the container, use of the device is not possible at an inverted position. Therefore, when this directional screw aligner is attached to a screw tightener using compressed air as a driving source, it is still not possible to use the combined device for driving screws into a ceiling.
U.S. Pat. No. 3,247,874 describes a mechanism for orienting random screws on a chute and supplying the screws one-by-one to a screw tightener on a first-in, first-out basis. This device uses a closing shutter to separate the first screw from the following one on chute and allows the first screw to fall into a chamber which leads to a screw tightener. Because this mechanism also utilizes gravity, reliability may be poor since clogging may occur depending on the orientation of the device in use. For the above reasons, conventional screw separator-feeders and screw tighteners are separately installed and hoses generally used to couple them.
SUMMARY OF THE INVENTION
The present invention is intended to solve the aforementioned problems and it is therefore an object of the invention to provide a non-directional screw aligner-feeder mechanism ensuring that all screws are aligned regardless of orientation of use.
It is a further object of the invention to provide a screw aligner-feeder which may be incorporated with a screw tightener.
It is yet another object of this invention to provide a screw aligner-feeder and screw tightener combination composed of materials which result in improved wearability.
It is further object of the invention to provide a screw aligner-feeder which is easily adjustable for use with screws of any length.
In order to accomplish the above-noted objects, there is provided a non-directional screw aligner comprising a container for containing a large number of screws, a pair of cone shaped guide walls formed opposite each other forming the container, an inlet for compressed air for stirring the screws along the peripheral direction of each guide wall of the container, a groove for receiving the shank portion of the screws and a screw alignment passage adjacent to the groove, the alignment passage being used to parallel the screws continuously received by the groove under the influence of compressed air supplied thereto.
A mechanism for isolating and feeding screws thus aligned carries the aligned screws via a chute to an outlet by means of compressed air. At the chute outlet, the mechanism further contains a stopper member equipped with a pawl which intervenes between the lead and second screws, an opening on the rearend side of a screw transfer chamber such that the screw may be driven out of the chute outlet and into the chamber, and a piston rod which delivers the screws supplied from the chamber to a screw passage. A stopper member limits the feed to a single screw. The invention further contains a system of air control valves which, when actuated, allow compressed air to enter the device thereby forcing a single screw out of the chamber and down a hose to a position such that the screw may be driven by the attached driver.
BRIEF DESCRIPTION OF THE DRAWINGS
Careful study of the following detailed description will allow for a better understanding of the instant invention in conjunction with the accompanying drawings, of which:
FIG. 1 is a vertical sectional view of the central portion of the screw aligner-feeder illustrating the preferred embodiment of the present invention;
FIG. 2 is a transverse sectional view of the central portion of the screw aligner-feeder of FIG. 1;
FIGS. 4a and 4b are enlarged perspective views of outlets for the air blown in the screw aligner-feeder;
FIG. 5 is a perspective view of a screw guidance section of the screw aligner feeder;
FIG. 6 is a perspective view illustrating the upper portion of the screw guidance section;
FIGS. 7a, 7b and 7c are sectional views taken on lines VIIa--VIIa, VIIb--VIIb and VIIc--VIIc of FIG. 6;
FIG. 8 is a perspective view of another screw guidance section of the screw aligner-feeder;
FIG. 9 is an elevation view of the principal portion of a magazine of the screw aligner-feeder;
FIG. 10 is a sectional view taken on line X--X of FIG. 9;
FIG. 11 is a perspective view of the principal portion of the magazine of FIG. 9;
FIG. 12 is a vertical sectional view of a screw tightener containing the screw aligner-feeder mechanism embodying the present invention;
FIG. 13 is a diagram illustrating a mechanism for driving a piston rod for delivering screws;
FIG. 14 is a sectional view taken on line XIV--XIV of FIG. 12;
FIG. 15 is a perspective view of the screw tightener containing the screw aligner-feeder according to the present invention;
FIG. 16 is a sectional view of the principal portion of the connection between the screw tightener proper and the screwed aligner-screw;
FIG. 17 is a vertical sectional view of the screw tightener for illustrating the operating mechanism of the screw aligner-feeder;
FIG. 18 is a diagram illustrating the operating conditions and set and timer valves; and
FIG. 19 is a perspective view of the connection between a contact arm and a member for receiving the arm.
DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENT
In FIGS. 1 and 2, a screw aligner is similar to that of a conventional screw aligner, wherein a pair of cone-shaped guide walls 2, face each other and form hopper 1. A guide groove 3, narrower than head N1 of screws N and wider than screw shanks N2 is formed in the periphery of guide walls 2. A magazine 6 having a screw alignment passage 5 communicating with guide groove 3 through a guidance section 4 is also shown. The screws contained in hopper 1 are stirred by means of compressed air forced into hopper 1 through blowing means 7. The screws are made to move along guide walls 2 so that they may fall into guide groove 3 in a certain alignment. The screws are forced from the guidance section 4 to screw alignment passage 5 under air pressure and aligned therein. The above described blowing means 7 is coupled to an outside air supply source (not shown).
Regardless of the position of the screws and the hopper, cone-shaped guide walls 2 in combination with the compressed air supply assure that the screws will be aligned in passage 5 regardless of the orientation of the hopper 1 when the device is in use. The ultimate screw alignment is shown in FIG. 2.
In the exemplary embodiment, the screw aligner body itself is formed from transparent engineering plastic. Internal members, however, such as head support edge 10, alignment passage 5 and separator 11 are preferably made of metal. Such a composition allows for improved wearability of the internal parts while still allowing an operator to visually check the number of screw remaining in the hopper. Durability and use are further improved since head support edge members 10 and separator member 11 are easily replaced. Because members 10 and 11 are fitted into groove 13, alignment of these parts upon replacement is assured.
The outlet of blowing means 7 is directed to hopper 1 and the opening of magazine 6 and simultaneously to screw alignment passage 5 from the rearside of guide groove 3 as shown in FIGS. 1, 3 and 4. FIG. 3 indicates one possible means of splitting the compressed air stream. The compressed air exiting from portion 7a of FIGS. 3 and 4 is used to stir screws in hopper 1. Air exiting from slit or tube 8 in FIGS. 3 and 4 is used to move screws along screw alignment passage 5.
It is clear therefore, that air pressure applied in the direction of guide groove 3 will force the aligned screws to alignment passage 5 of magazine 6. This arrangement ensures that all screws are transferred to the magazine 6 smoothly and certainly such that a continuous stream of screws is available for use in chamber 12. Once in chamber 12, the screws are pushed forward by ejecting means 14 which is also operated by compressed air. It will be noted that in use, the above described screw feed mechanism results in improved feed efficiency and therefore improved ease of use.
FIG. 5 details screw guidance section 4. Screw guidance section 4 is composed of a screw guidance recess 4a and a screw head receiving face 4b formed at the bottom thereof. The screw guidance recess 4a is formed by cutting out the guide wall to the extent that at least the head of one screw end can be accommodated, whereas the screw head receiving face is made contiguous with an aligned screw head supporting face 507 in screw alignment passage 5. Front end 11a of the separator 11 is formed at roughly the same level as edge 509 between guide wall 2 and guide groove 3.
In this embodiment then, the screws contained in hopper 1 in bulk are stirred along guide walls 2 by compressed air blown out of blowing means 7 and allowed to fall into guide groove 3 with their heads aligned. Subsequently, the screws are guided to guidance recess 4a of guidance section 4 by the compressed air. As shown in FIGS. 6 and 7, the heads in one of the aligned screws supported by edge 509 between guide wall 2 and guide groove 3 are made to fall onto screw head receiving face 4b at the bottom of guidance recess 4a. Flat, pan and hexagonal head screws may all be used in the present invention with equal ease using the above construction. Since the screw head receiving face 4b is contiguous with screw supporting face 507 of screw alignment passage 5, the screw heads are prevented from being caught by separator 11 and are therefore smoothly delivered to screw alignment passage 5 by the compressed air.
Moreover, since the front end 11a of the separator 11 is arranged at roughly the same level as edge 509 between guide wall 2 and guide groove 3, it will constitute no obstacle to the stirring of the screws revolving within the hopper 1. Accordingly, the screws may be efficiently stirred without unduly wearing separator 11.
The configuration of guidance section 4 is not limited to the construction shown in FIGS. 5 and 6. As shown in FIG. 8, for instance, edge 509 between guide wall 2 and guide groove 3 may be formed at the same level as the screw heads supporting face 507 of screw alignment passage 5. The screw guidance recess 4a may be formed by cutting out guide wall 2 to the extent that at least the head of one screw can be accommodated, and the screw head receiving face 4b may be made contiguous to screw head supporting face 507.
In the above-described guidance section, the under surfaces of the heads of the screws are supported by the screw head receiving face formed at the bottom of the guidance recess. As the screw head receiving face is contiguous to the screw head supporting face of the screw alignment passage, the heads of the screws in the guide groove have already been placed at the same level as those supported on the screw alignment passage when the screws are introduced in the guidance section. The heads of the aligned screws supported by the edge between the guide wall and the guide groove are therefore smoothly guided to the screw supporting face of the screw alignment passage through the screw head supporting face in the screw guidance section without being caught by the separator. This also allows the use of different types of screws in the device.
FIGS. 9 through 11 show a mechanism for regulating magazine 6 for feeding screws arranged in the screw alignment passage up to cylindrical transfer chamber 12 of a screw tightener. Magazine 6 is equipped with a screw feed passage 902 for guiding and feeding the screws arranged within hopper 1 to cylindrical transfer chamber 12 arranged at the front end of screw feed passage 902. Compressed air is made to flow from hopper 1 to the transfer chamber 12 through screw feed passage 902 and the air flow is used to align the screws from hopper 1 in screw feed passage 902. Subsequently, the lead screw, having been separated from the following one, is fed from transfer chamber 12 to a tool such as a screw tightener (not shown).
Screw feed passage 902 is separated from hopper 1 by partition 11 and composed of a pair of side walls 905. Walls 905 face each other for supporting the screws in an aligned state. The aligned screws within the screw feed passage 902 are delivered to transfer chamber 12 by the compressed air flow.
Part 905a located adjacent to transfer chamber 12 (see FIG. 11), and part 12a of chamber 12 are each made part of divided side wall member 907 Member 907 is hingedly coupled to the screw feeder body by hinges 908a, 908b. A lock member 909 is attached to side wall 905 continuous to the side wall member 907. (See FIG. 9). When side wall member 907 is opened, lock member 909 is released, whereas lock member 909 is locked when side wall member 907 is shut. When side wall member 907 is opened, screw feed passage 902 and part of cylindrical chamber 12 are exposed.
As shown in FIG. 11, spacing member 910 is arranged in between side walls 905 and contains an adjustment hole 911 extending in the axial direction of the screws aligned in screw feed passage 902. Hole 911 is fixed by a fixing screw 912 driven into screw holes made in facing side walls 905 corresponding with the long hole 911.
Spacing member 910 may also be fixed by inserting a fixing screw into a screw hole in side walls 905 facing a recessed groove (not shown), in place of the long hole, made in one side of the bottom member, and fitting and pressing the lip of the fixing screw into and against the recessed groove.
Parallel opposed ridges 913 and 914 capable of engaging with each other, are formed on the opposed faces of side wall member 907 and spacing member 910. Ridges 913 and 914 run parallel to the direction of movement of screws in screw feed passage 102. Accordingly, opposed ridges 913 and 914 are engaged when side wall member 907 is in a closed position, ensuring that spacing member 910 is always kept parallel to screw feed passage 902.
The inside diameter of chamber 12 is made large enough to allow the passage of only one screw at a time. One side of the rear end of chamber 12 is opened to the front end of screw feed passage 902. The front end of chamber 12 is coupled to a tool such as a screw tightener, and a piston rod ejecting means 14 is positioned at the rear thereof. The rear end of chamber 12 is in two parts to allow access to the chamber when side wall member 907 is opened.
The ejecting means 14 is used to push the lead screw toward the front of the chamber so that the screw may be delivered by means of compressed air to the position where it is easily fed to a screw tightener. The ejecting means 14 normally comprising an air cylinder or piston rod.
In order to adjust spacing member 910 to the height of the screws to be used in a given application, side wall member 907 is opened to expose screw feed passage 902, the screws to be used are placed in screw feed passage 902, spacing member 910 is adjusted to the length of the screws, fixing screw 912 is tightened in place, side wall member 907 is closed to let parallel ridges 913 and 914 engage with each other, and finally the magazine is locked using lock member 909. The height of screw feed passage 902 is thus properly adjusted and the spacing member 910 is kept parallel to screw feed passage 902. Consequently, the compressed air flow is efficiently employed to feed the aligned screws while it is flowing through screw feed passage 902, and the screws are delivered to chamber 12, separated from each other, and subsequently fed to a tool such as a screw tightener.
Since the height of the screw feed passage 902 of magazine 6 is simply adjustable to the length of screws for use as aforementioned, the compressed air flow is allowed to pass through screw feed passage 902 efficiently to ensure that the screws for use are smoothly supplied.
In case screw feed passage 902 or chamber 12 is clogged with a screw for some reason while magazine 6 is operated, the screw can be taken out simply by opening side wall member 907 without disassemblying the apparatus. Although the engagement of the face of side wall member 907 with the opposing face of spacing member 910 is released, bottom member 910 is fixed to the side walls 905 with fixing screw 912 and the adjusted position is thereby maintained.
The direction in which side wall member 907 is opened is not limited to what has been described in reference to the above embodiment. Moreover, the means for keeping bottom member 910 parallel to screw feed passage 902 is not always limited to the use of ridges 913 and 914. There may be used, for instance, a rail on which spacing member 910 slides in parallel to screw feed passage 902 or other combinations of parts which engage each other when in the closed position.
FIGS. 12-14 show a screw tightener mechanism equipped with a separator-feeder mechanism for separating and feeding screws to the screw tightener via the magazine mechanism.
In FIG. 12, the screws separator-feeder mechanism is represented by a reference character C. The screw separator-feeder mechanism C comprises a stopper member 113 slidably installed at front end outlet 5a of chute 5 for aligning the screws by means of the above-described screw alignment mechanism, a piston rod 14 movably installed at the rear end of chamber 12 communicating with outlet 5a, and an actuating member 15 oscillatably provided in the position where piston rod 14 moves back and forth.
The front end of chute 5 is open and the rear end side of chamber 12 is made to communicate with the outlet 5a. The chamber 12 is designed to feed screws using air to a nose 1 installed in front of the screw tightener, nose 1 being slidable in the axial direction. The screws are aligned on chute 5 by compressed air and sent from front end outlet 5a to the rear end of chamber 12 and then fed to the nose of the screw tightener. However, because the alignment direction is roughly perpendicular to the feed direction, the compressed air perpendicularly hits the shank of the screws sent to the rear end of chamber 12 and consequently the screws are pressed against only the inside wall of chamber 12 but not made to move forward. In order to make the screws move forward using compressed air, they must be delivered to the position P of the chamber 12. Piston rod 14 is installed as means for thus delivering the screws to position P.
Piston rod 14a of FIG. 13 is projected from the tip of piston 14 slidably contained in a cylinder 20 and movable from the rear end of and into chamber 12. When the piston rod 14 moves back, it moves back behind the heads of the aligned screws in chute 5 after opening chamber 12 so that the screws may be supplied from outlet 5a into chamber 12.
The piston driving mechanism is so arranged as to move back and forth while the driving air is supplied to the screw alignment mechanism. In other words, actuating member 15 swings in a direction opposite to the movement of piston rod 14a abutting against the engaged boss 15a of actuating member 15. Simultaneously, stopper member 113 swings interlockingly in the direction opposite thereto to make pawl 113a retreat from holding the second and following screws in position. The screws in chute 5 are thus freed, whereas only one screw is sent to the front end of chute 5. That procedure is repeated so that the lead screw of those aligned on chute 5 may successively be delivered to feed position P. The compressed air supplied from air supply hole 7 causes each screw to reach the fixed position where it is fed into the screw tightener.
FIGS. 12 and 13 further describe the mechanism for driving the piston rod 14a via compressed air supplied to drive the screw alignment mechanism. The compressed air supplied from driving air supply port 22 into cylinder 20 works on the front side of piston 14, the side having a small effective pressure receiving area, and causes piston 14 to retreat from the front side against the force of a spring 17 toward an exhaust valve located opposite thereto (piston rod 14a moves back). Piston 14 engages with and presses exhaust valve 18 at the end of its back movement. Exhaust valve 18 moves against the force of a spring 19 to the position where it intercepts the air from cylinder 20 and makes airtight one side of cylinder 20, that side being opposite to exhaust valve 18 (FIG. 13). However, the compressed air supplied from driving air supply port 22 is supplied from the front side toward exhaust valve 18 through a communicating pipe 23 and the pressure within cylinder 20 on exhaust valve 18 side is increased. As the pressure inside exhaust valve 18 increases, the pressure working on piston 14 surpasses the pressure on the supply side because the effective pressure receiving area of the piston on its exhaust valve 18 side is set greater than that on its front side and because spring 17 force works on its front side. Consequently, piston 14 is caused to move forward to the front side when piston rod 14a moves forward and enters chamber 12, causing the screw to move to position P. The inside pressure above allows exhaust valve 18 to remain in the intercepting position. When piston 14 returns to its initial position, the supply of compressed air is stopped and it is discharged, whereby the pressure within cylinder 20 is reduced. Consequently, exhaust valve 18 is energized by spring 19 and returned to the position where cylinder 20 is allowed to communicate with the air, so that the initial air pressure is restored as the air in cylinder 20 is discharged therefrom.
FIG. 14 shows that stopper member 113 is equipped with pawl 113a at one end and abutting piece 113b at the other, and oscillatably installed at front end outlet 5a. An oscillating shaft 121 is provided with a spring 122, which energizes pawl 113a of stopper member 113 and abutting piece 113b so that the former and the latter may rise and fall, respectively. Pawl 113a is arranged to penetrate in between the lead screw and a second screw and retreat therefrom when it oscillates.
As seen in FIG. 12, actuating member 15 is plate-like, one end of which is pivotally coupled to oscillating shaft 125 fixed to the position where piston rod 14a moves back and forth, whereas inclined face 15b is formed at the other end, the intermediate portion being provided with an engaging projection 15a. Inclined face 15b is made to abut against and engage with the abutting piece 113b of the stopper member 113 and the rear end of projection 15a is cut obliquely. Moreover, oscillating shaft 125 is equipped with spring 16 by which inclined face 15b and engaging projection 15a are respectively energized toward chamber 12 and stopper member 113. When piston rod 14 is in the rear position, actuating member 15 is energized by spring 16 and its engaging projection 15a is deeply inserted into chamber 12. At the same time, inclined face 15b is moved toward stopper member 113. Abutting piece 113b then slides upward along inclined face 15b and is pushed up against the force of spring 122 whereby stopper member 113 oscillates around the oscillating shaft 121, allowing pawl 113a to enter the front positron of the second screw in chute 5. In the reverse action, projection 15a is pushed back by, and made to engage with the piston rod, while inclined face 15b retreats from stopper member 113. At this time, the abutting piece 113b is slid downward along inclined face 15b by the force of spring 122 and stopper member 113 is oscillated around oscillating shaft 121, forcing pawl 113a to retreat. The oscillations of actuating member 15 and stopper member 113 are thus interlocked.
When piston rod 14a is moved back using the compressed air from air source 103 while the compressed air for driving the screw alignment mechanism A is supplied from the air source, actuating member 15 correspondingly oscillates and pawl 113a of stopper member 113 moves forward to the front of the second screw according to the oscillation of actuating member 15. As the lead screw is free when the second and the following screws in chute 5 are checked by pawl 113a, the lead screw is separated from the following ones. When piston rod 14a retreats from screw chamber 12 and the lead screw is pushed into chamber 12 by compressed air. Subsequently, when piston rod 14 moves forward, the screw in chamber 12 is delivered to feed position P by piston rod 14 and fed by compressed air to a fixed screw driving position at the nose of the screw tightener. When piston rod 14a moves forward it abuts actuating member 15, causing actuating member 15 to oscillate in the direction opposite to the movement of piston rod 14, and retreats from the above position. A single screw among those in chute 5 is simultaneously sent to the front end of the chute by the compressed air. When piston rod 14 is then moved back, actuating member 15 oscillates as aforementioned and pawl 113a correspondingly moves forward to the front of the second screw to check the delivery of the second and following screws, whereas the lead screw is separated from the second and supplied into the opened screw passage. This procedure is repeated to deliver and feed each lead screw successively to the feed position and then to the screw tightener using the compressed air.
FIG. 15 depicts the screw aligner-feeder and tightener as a whole, including screw tightener B. Screw tightener B contains an air motor (not shown) with a driver bit held therein. Screw tightener body A2 is equipped with a nose 101 forwardly projected from the driver bit which is made to slide in the axial direction, and air control device 27. During the initial period of the actuating stroke of nose 101, air control device 27 allows communication between air passages 25 and 26. Air is supplied from air source 103. During the late period of the actuating stroke, as the driver is pulled away from a wall for example, air control device 27 cuts off communication of both air passage 25 and 26. Air control device 27 may be constructed of a contact arm 28 coupled to nose 101, and a valve for intermittently cutting off communication of air passages 25 and 26, depending on the movement of contact arm 28.
The screw tightener body A1 is rotatably coupled to screw aligner-feeder body A2 with oscillating shaft 30. Accordingly, screw feeder A1 is oscillatably coupled to screw tightener body A2 with oscillating shaft 30 as a pivot. (FIG. 16). Oscillating shaft 30 is formed of a hollow body with one end connected to air source 103 through air control device 27 of the screw tightener body A2 and air passage 25. The other end is connected to screw aligner-feeder A through air passage 26a. Therefore, no air passages need to be installed externally.
Moreover, nose 101 and screw separator-feeder mechanism 107 of the screw feeder A1 are coupled together through hose 102. The screws supplied from screw aligner-feeder A are supplied through hose 102 to nose 101.
As screw aligner-feeder A is equipped with the screw aligner and screw separator-feeder mechanisms, the screws contained at random in hopper 1 can be aligned and successively supplied through hose 102 to nose 101 using compressed air. Nose 101 is pressed against the surface to which the screw is to be applied and made to slide in an axial direction along screw tightener body A2. Hose 102 is pressed in the same direction at that time. As hose 102 has intrinsic strength, the screw aligner-feeder is forced back around shaft 30 by hose 102 as shown in FIG. 12. This aspect of the invention keeps hose 102 from kinking, thereby avoiding blockage of the hose.
Although FIG. 12 illustrates screw aligner-feeder A oscillating while piston rod 14 is in the forward position, the oscillation of the screw aligner-feeder and the screw pushing operation are normally separately conducted and the illustration in the figure is not definitive.
FIGS. 17-19 depict a compressed air control means for controlling the compressed air from an air source to the above-described apparatus. In the screw tightener employing compressed air as a power source according to the present invention, the screw tightener body and the screw feeder are driven by a common air source. Consequently, there is an inherent disadvantage that, if both units are simultaneously driven, the air pressure for driving the screw tightener may be reduced and thus fail to tighten screws completely.
In order to solve this problem, the nose member is forwardly projected from screw tightener body over the drive bit and slidably installed along the axial line defined by the bit. The screw tightener body is equipped with an air chamber having a small exhaust hole; a set valve for letting an inlet port connected to the air source communicate with a first coupling port; and a first coupling port connected to the actuating chamber of a timer valve or a second coupling port provided in the timer valve. In this construction, the set valve itself is operatively coupled to the nose member, and the timer valve containing an actuating chamber at one end is used for making the first coupling port communicate with the air chamber and intermittently cut off an outlet port connected to the second coupling port and the screw feeder. The set valve is operated so as to make the inlet port communicate with the first coupling port based on the movement of the nose member as it is initially pushed against a surface. The timer valve then communicates with the second coupling port and the outlet port when the pressurized air is supplied to the actuating chamber. The air source communicates with the second coupling port based on the movement of the nose member in the last period of the actuating stroke of the nose member, and the timer valve self-holds until the pressure in the air chamber is reduced to a fixed level. Thus, the valves allows transfer of the full force of the compressed air to the driver as needed, and to the aligner-feeder otherwise, as shown in FIG. 17.
FIG. 17 shows a screw tightener D containing air motor 702 in screw tightener body C. The compressed air supplied from an air source is used to drive the air motor 702 and rotate driver bit 704 connected to the output shaft thereof, so that the screw attached to the front end of the driver bit 704 is driven into a material (not shown). Air motor 702 is supplied with air in a manner analogous to the embodiment illustrated in FIG. 2 and the embodiment of FIG. 15, though this connection is not shown in detail in FIG. 17, for clarity. Screw tightener D is also equipped with a mechanism for actuating a screw feeder A for supplying screws to the front end of driver bit 704.
The mechanism for actuating screw feeder A comprises nose member 706 provided at the front end of screw tightener body C, set valve 707, timer valve 708 and air chamber 709. Set valve 707 is operationally coupled to nose member 706 through contact arm 710. Set valve 707 and timer valve 708 are operated in accordance with the movement of nose member 706 accompanied by the operation of screw tightener C. Air source 703 is connected to air chamber 709 when screw tightener C is operated to drive screws and to the screw feeder while screw tightener C is not operated.
Nose member 706 is cylindrical and provided with a screw passage branching off the cylinder. Nose member 706 is forwardly projected from driver bit 704 installed in screw tightener body C and slidably provided along the axial line and always forwardly energized by a spring (not shown). One end 710a of contact arm 710 is coupled to nose member 706 is the direction wherein it sides.
Set valve 707 and timer valve 708 are installed close to screw tightener body C and respectively communicate with first and second coupling ports 711 and 712.
Set valve 707 accommodates slidable valve stem 715 with valve housing 714 equipped with the first and second coupling ports 711 and 712 communicating with timer valve 708, and inlet port 703a communicating with the air source 703 so as to energize one end of valve stem 715 by means of spring 716. Inlet port 703a and second coupling port 712 are connected in the position (shown in FIG. 17) to which valve stem 715 has moved against the force of spring 716, whereas inlet port 703a and first coupling port 711 are connected when valve stem 715 has moved to the position (shown in FIG. 18) energized by spring 716. In FIG. 19 it is seen that one end 717a of receiving member 717 is fixed to the end of spring 716 of valve stem 715. Bent piece 719 having through hole 718 is formed at the other end of receiving member 717 and the free end of contact arm 710 is fitted into through hole 718 in such a manner that the contact arm is permanently held by receiving member 717. The stroke of valve stem 715 is set smaller than the actuating stroke of nose member 706 and the difference therebetween is defined as a play L between bent piece 719 of receiving member 717 and the end of contact arm 710 in the shifted position of nose member 706 when it is moved toward screw tightener body C. If nose member 706 is returned to the original position again, the end of contact arm 710 will catch bent piece 719 in the meantime to cause receiving member 717 to move. Accordingly, valve stem 715 will move to the associated position in the initial or last position of the actuating stroke.
The valve arrangement further contains timer valve 708, slidable valve stem 721 within valve housing 720, spring 724, and actuating chamber member 722. In use, the movement of the valves ensures that actuating chamber 722 always communicates with first coupling port 711 and with air passage 709a connected to air chamber 709. A second coupling port 712 is connected to set valve 707 and outlet port 705a which is connected to the screw feeder. When valve stem 721 moves to the position energized by spring 724 (as shown in FIG. 17), outlet port 705a is disconnected from second coupling port 712 and screw feeder 705 is cut off and ports 712 and 705a are not allowed to communicate with each other.
Air chamber 709 is installed in the rear of screw tightener body 701 and equipped with a small exhaust hole 723. Even if the pressurized air is supplied to air chamber 709, the air will be discharged from small exhaust hole 723 and the pressure inside air chamber 709 will gradually reduce as time elapses.
As screw tightener C operates to drive a screw, driver bit 704 and a screw attached to the tip of driver bit 704 is pressed against a material into which it is driven. Nose member 706 is then slid along the axial line of driver bit 704. Contact arm 710 subsequently moves to release the engagement of end 710b of contact arm 710 and valve stem 715 is moved by the force of spring 716 to the position where inlet port 703a is allowed to communicate with first coupling port 711. Consequently, pressurized air from air source 703 is supplied from the first coupling port 711 to air chamber 709 through the actuating chamber 722 of timer valve 708. As the pressure inside air chamber 709 increases, the pressure in actuating chamber 722 is increased and accordingly valve stem 721 moves against the force of spring 724 to the position where second coupling port 712 is allowed to communicate with outlet port 705a connected to screw feeder 705 (see FIG. 18). At this time, second coupling port 712 is kept cut off inlet port 703a and air source 703. Accordingly, the pressurized air is supplied to air chamber 709 while screw tightener C is operating but not supplied to screw feeder 705.
When operation of the driver bit is stopped, however, nose member 706 is slid in the opposite direction along the axial line of driver bit 704. Contact arm 710 then moves in the opposite direction to the aforementioned, allowing the end of contact arm 710 to engage with receiving member 717 at the end of the return process. Consequently, set valve 707 is returned to its original position where inlet port 703a communicates with second coupling port 712, and at the same time inlet port 703a is cut off from first coupling port 711. However, timer valve 708 is held in place in the above-described position because of the pressurized air acting in air chamber 709. For this reason, inlet port 703a is made to communicate with outlet port 705a of the screw feeder through second coupling port 712, so that pressurized air is being supplied to the screw feeder 705. As there is provided small exhaust hole 723 in air chamber 709, the pressure in the air chamber gradually decreases to a fixed level after predetermined time elapses and the force of spring 724 surpasses the pressure to release the self-holding timer valve 708. Accordingly, the valve stem 721 moves to a position where outlet port 705a is cut off from second coupling port 712. This action ensure screws will be fed to the driver before the next screws is to be aligned.
As the mechanism of screw feeder 705 is designed to cut inlet port 703a off outlet port 705a in response to the actuating stroke of the nose member, it is impossible to supply the pressurized air to screw feeder 705 while screws are tightened and tighten screws while the screw feeder 705 is driven. Moreover, because set valve 707 operates in the initial and last periods of the actuating stroke of nose member 706, the supply of the air to air chamber 709 allows thus action.
In the screw aligner-feeder according to the present invention, one and the same air system can be used as a power source for aligning, feeding and tightening screws. Since a screw aligner and a screw tightener can be used in one body, the radius of operation is not limited. Moreover, the screw alignment and distribution mechanisms operated by compressed air allow nondirectional operation, i.e., operation of the device is the same whether driving screws into a floor or a ceiling.
Although only a few embodiments have been described in detail above, those skilled in the art will readily appreciate that many modifications are possible in the preferred embodiments without materially departing from the novel teachings and advantages of this invention. Accordingly, all such modifications are intended to be included within the scope of this invention as defined by the following claims.
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A hand held pneumatic screw aligner feeder device which may be used in any orientation incorporates a container for loose screws made up of two cup shaped walls forming a hopper, a groove between the walls used to align the screws, a separator to keep unaligned screws out of the groove, a chute to carry the screws to a pawl which allows only a single screw to be delivered to a transfer chamber and an inlet for compressed air along one of the hopper walls. The device may be coupled to a pneumatic screw tightener such that a screw in the transfer chamber is forced down a hose to the nose of the tightener so that the screw may be forced into an external surface. An actuating valve system within the aligner feeder tightener device, coupled to the tightener nose allows compressed air to flow to the aligner feeder when the tightener is not in use, and to the tightener only when the tightener is activated.
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This is a continuation-in-part of my prior copending U.S. patent application Ser. No. 629,694, filed Nov. 7, 1975 for "Measuring Liquid Dispenser With Flat Top" and now issued as U.S. Pat. No. 4,057,174.
BACKGROUND OF INVENTION
For the precise dispensing or transfer of fluids there have been developed a wide variety of devices and exemplary patented devices of this type are identified in my above-noted copending patent application which discloses a further advancement in this field. For many applications the precision with which liquids can be dispensed is of utmost importance and the reproducibility of these precise dispensations is also of major importance. The scale post of U.S. Pat. No. 3,452,901 is highly advantageous in this respect, and the gauge rod of my above-identified patent application provides an additional degree of precision and reproducibility. It has been discovered however, that the provision of an upstanding indexed post or rod upon a bottle cap or the like results in a structure of limited stability. Such a measuring element is susceptible to some tilting so as to be slightly misaligned with the axis of a pump plunger. Inasmuch as the stroke of the pump plunger is fixed by the upwardly extending measuring means, any misalignment may produce a mismeasurement so as to decrease the reproducibility of successive dispensing operations. For many applications precise reproducibility is of prime importance and thus only very slight variations in the metered volume of liquid dispensed by successive operations may be unacceptable or at least highly undesirable.
SUMMARY OF INVENTION
The present invention comprises a liquid dispenser of the type disclosed in my copending patent application Ser. No. 629,694, and provides particular improvements thereover. The dispenser hereof comprises a cap structure adapted for attachment to the open top of a container for liquid and having all portions thereof normally depending from the cap structure so as to be normally disposed within the container. A manually operable pump is provided by a pump cylinder or barrel depending from the cap structure with inlet and outlet valving connected to the bottom of the barrel and a cylindrical plunger slidably disposed within the barrel for drawing fluid into the barrel and expeling fluid therefrom by plunger reciprocation.
The present invention provides a new and improved manner of precisely metering the amount of fluid displaced by each reciprocation of the pump plunger. In accordance with the present invention, a limitedly movable gauge rod is disposed in parallel spaced relationship to the pump plunger in extension through the cap structure and normally disposed within a sealed tube depending from the cap structure. About the lower end of the gauge rod there is provided a lateral extension adapted to engage the under side of the cap structure as the gauge rod is moved longitudinally of the axis thereof in order to limit the vertical displacement of the gauge rod. An enlarged upper end upon the pump plunger is normally disposed atop the cap structure and extends laterally from the pump plunger to accommodate extension of the gauge rod through this enlarged end. The gauge rod is slidably disposed in the lateral extension of the upper end of the pump plunger and means are provided for locking the gauge rod in desired longitudinal relationship to the pump plunger, as indicated by indicia disposed longitudinally along the gauge rod.
The present invention provides for reciprocation of the pump plunger and gauge rod and, inasmuch as the gauge rod has a limited axial movement, the plunger stroke may be precisely adjusted by fixing the relative longitudinal position of the gauge rod and pump plunger. With these elements fixed in predetermined longitudinal relationship, each complete or full stroke of the pump plunger will, in fact, dispense a predetermined and precisely reproducible amount of fluid. Prior art problems of mounting indicating means for a liquid dispenser are overcome by the structure of the present invention. Additionally, the present invention provides for maintaining the parallelism between pump plunger and indicating means under all circumstances so as to maximize the precision of metering.
DESCRIPTION OF FIGURES
The present invention is illustrated as to a single preferred embodiment thereof in the accompanying drawings, wherein:
FIG. 1 is a top plan view of a liquid dispenser in accordance with the present invention;
FIG. 2 is a central vertical sectional view of the dispenser of FIG. 1 attached to a container for liquid and taken in the plane 2--2 of FIG. 1;
FIG. 3 is a transverse sectional view of the dispenser hereof taken in the plane 3--3 of FIG. 1; and
FIG. 4 is a partial side view of the upper portion of the dispenser hereof taken in the plane 4--4 of FIG. 3.
DESCRIPTION OF PREFERRED EMBODIMENT
The preferred embodiment of the present invention illustrated in the accompanying drawings comprises a cap structure 11 including a circular plate or floor 12 having a depending annular flange or wall 13 thereabout and an upstanding annular wall 14 thereabout. The annular depending flange 13 is shown to be provided with internal threads for threading of the cap structure 11 onto the open top of a liquid dispenser such as a bottle 16. For convenience of manufacture, the cap structure may also include a lower plate 17 secured in contiguous relation immediately beneath the floor of plate 12 as by screws or bolts 18 extending through the lower plate into threaded engagement with the plate 12. This lower plate 17 may have a somewhat greater thickness than the thickness of plate 12, for reasons noted below, and is preferably formed with an annular shoulder having a diameter that is less than the thread diameter of the flange 13 so as to fit into the neck of the bottle 16, as shown in FIG. 1.
The dispenser of the present invention includes a small manually or machine operable pump 21 comprised as an open topped cylindrical tube or barrel 22 depending from the cap structure and mounted thereon as by a lateral flange 23 about the open top thereof disposed in an indentation in the upper surface of the lower plate 17 so that the lower plate then fits under this flange to hold the barrel in position, as shown. Within the pump barrel or cylinder 22, there is slidably disposed a cylindrical piston or plunger 24 which may be formed as a hollow cylinder with a closed bottom end and which fits the interior of the barrel in very close sliding engagement so as to preclude the passage of liquid thereabout. The pump plunger 24 extends from the bottom of the cylinder 22 upwardly through the floor 12 of the cap structure.
At the bottom of the pump cylinder or barrel 22 there is provided an inlet line 31 communicating with the interior of the barrel at the bottom thereof. A check valve 32 is provided in this inlet line which is preferably dimensioned to depend substantially to the bottom of the container or bottle 16 upon which the present invention is adapted to be mounted. A pump outlet line 41 communicates with the interior of the barrel 22 through a side of the barrel at the bottom thereof and slants slightly upwardly therefrom for connection to an outlet check valve 42. A dispenser tube or nozzle 43 is disposed above the floor or plate 12 and is connected as by means of a flexible tube through the cap structure to the check valve 42 with a portion of the outlet tube 43 extending laterally outward of the cap structure through a slot in the upstanding wall 14 thereof. Reciprocation of the pump plunger 24 will be seen to draw liquid through the check valve 32 and inlet line 31 into the pump barrel 22 and thence to discharge such liquid through the outlet line 41 and check valve 42 to the outlet tube or nozzle 43. This pump structure is substantially the same as that shown in my above-noted copending patent application.
The present invention provides for very precise metering of liquid dispensed thereby and to this end there is provided an elongated gauge rod 51 having indicia 52 marked thereon along the length thereof and normally disposed to depend from the floor of the cap structure. The gauge rod 51 extends through aligned openings in the upper and lower plates 12 and 17 of the cap structure and beneath the cap structure the gauge rod is disposed within a tube 53 having a closed lower end and an open upper end secured to the lower plate 17 as by threaded engagement therewith at the gauge rod opening therethrough. The tube 53 seals the gauge rod from liquids in the container 16.
The gauge rod 51 is adapted for limited axial or longitudinal movement and the extent of upward movement of the rod is limited by a collar or the like 54 secured about the lower end of the gauge rod as by means of a screw or bolt 56 threaded through the collar and bearing upon the gauge rod or extending into an indentation therein. The cross-sectional dimensions of the upper open end of the tube 53 are greater than those of the collar 54 so that the gauge rod with collar thereon may be inserted in the tube from the top and a washer 58 is disposed atop the tube 53 and held in position thereat by the upper rim of the tube forcing the washer against a shoulder 57 on the lower plate about the gauge rod opening therethrough. The washer 58 has a central opening therethrough which is dimensioned to slidably accept the gauge rod in extension therethrough so as to close off the interior of the depending tube 53. Upward movement of the gauge rod is limited by the collar 54 thereabout which will engage the washer 58 as the gauge rod is moved upwardly to its maximum extent.
Atop the pump plunger 24 there is attached a lateral extension or block 61, preferably having a planar under surface adapted to normally rest upon the floor 12 of the cap structure. The gauge rod and pump plunger are disposed in spaced parallel relationship with the gauge rod 51 slidably extending vertically through the lateral extension or block 61 atop the plunger. Provision is made for locking the gauge rod in adjusted longitudinal relationship to the pump plunger and to this end there may be provided an annular collar 62 disposed in an indentation in the block 61 about an opening 63 therethrough. The gauge rod 51 extends through this opening 63 and through the collar 62, as illustrated in the drawings, with a pin 64 threaded through the collar and extending through a lateral notch in the block with a knurled outer end 66. The gauge rod is slidably extended through the opening 63 in the block 61 and also through the collar 62 therein so that the longitudinal position of the gauge rod may be adjusted. With the gauge rod appropriately positioned in extension through the block 61, the pin 64 is turned to cause the inner end thereof to bear against the gauge rod 51 and to lock the rod in adjusted position relative to the block 61 and thus to the pump plunger 24. Atop the gauge rod 51 there is provided a top or cap 67 which is secured to the upper end of the gauge rod and extends laterally outward therefrom. The collar 62 and pin 64 therein is adapted to snap into the depression in the block 61 so as to be normally locked therein, as indicated in FIG. 4, and it is, of course, also possible to eliminate the collar and thread the pin 64 through the block 61.
It will be appreciated that the gauge rod and associated elements are assembled in a particular order during fabrication of the present invention. The gauge rod with the collar 54 thereon is first inserted in the tube 53 and the washer is then slid over the gauge rod so as to rest against the top of the tube 53. The gauge rod is then inserted through the openings in the cap from the bottom and the tube 53 is threaded into the lower plate 17. The pump plunger 24 is then lowered into the pump cylinder 22 with the lateral extension 61 fitting over the top of the gauge rod so that the gauge rod is extended through the opening 63 therein. With the collar 62 already inserted in the extension 61, the gauge rod will likewise extend through the central opening in the collar 62 so that the resultant structure is substantially that illustrated in FIG. 2 of the drawings. The top 67 is then secured to the gauge rod 51 so that all of the foregoing elements are, in fact, removably locked together.
The lateral extension 61 on the pump plunger 24 rests upon the cap floor 12 when the plunger is fully depressed so that the bottom thereof engages the bottom of the pump cylinder 22. The vertical height of the lateral extension 61 is no greater than the height of the upstanding wall 14 above the floor 12 so that the device normally presents a substantially flat top in order to facilitate the stacking of liquid containers or bottles 16 containing devices in accordance with the present invention. The upstanding wall 14 may be provided with cutouts as indicated at 71 and 72, in order to facilitate gripping of the lateral extension or block 61 in order to manually operate the pump 21. There is also provided a vent through the cap structure 11, as indicated at 78, and a removable cover is preferably provided therefor. This then provides for venting the interior of the bottle 16 in order to accommodate the pumping of fluid or dispensing of fluid therefrom by the present invention. It is also noted that the lower plate 17 of the cap structure is provided with a fairly substantial thickness in order to provide threads for the attachment of the tube 53 thereto and to engage the under side of the flange 23 about the pump cylinder 22. The peripheral configuration of the lower plate 17 is preferably such that the outer portion of the plate at the top thereof rests upon the top rim of the bottle 16, as illustrated in FIG. 2. The lower plate 17 is indented about the periphery thereof below this lateral extension so as to form a shoulder and preferably this thicker portion of the lower plate is dimensioned to engage the inner circumference of the top opening of the bottle 16. In this manner a tight seal may be effected about the top of the bottle.
Operation of the present invention is quite simple and, in fact, is quite similar to the operation of at least certain other dispensing devices including that of my above-noted copending patent application. The device hereof is threaded onto or otherwise attached to the open top of a container 16 having a liquid therein. The pump plunger 24 is reciprocated a number of times to purge the device of any entrapped air. With the pump plunger fully depressed, so that the lateral extension 61 thereof rests upon the floor 12 of the cap structure, the gauge rod 51 is raised as by gripping the top 67 thereof until the desired volume of fluid to be dispensed per stroke, as indicated by the markings 52, is aligned with the top of the lateral extension 61. The pin 64 is then turned as by the knurled end 66 thereof to thread the pin into the collar 67 and tighten the inner end of the pin against the gauge rod so as to lock the relative longitudinal positions of the pump plunger 24 and gauge rod 51. In this condition the device hereof is ready for successive operations to dispense the exact indicated amount of fluid for each full reciprocation of the pump plunger 24. At any time it is desired to change the amount of fluid dispensed per stroke of the pump, it is only necessary to depress the pump plunger until the lateral extension 61 thereof rests upon the floor 12 of the cap structure and, upon release of the gauge rod 51, to longitudinally move the gauge rod so that the new desired volume to be dispensed is indicated on the marking 52 at the top of the extension 61 and then to again lock the gauge rod. An individual stroke of the pump is accomplished by gripping the block or lateral extension 61 and drawing it upwardly as, for example, into the position shown in phantom in FIG. 2 of the drawing. The illustration of FIG. 2 shows the pump plunger in an intermediate position during the progress of a stroke wherein the gauge rod may be further moved upwardly a distance indicated as X on the figure. At the end of this vertical displacement X, the top of the collar 54 will engage the under side of the washer 58 to prevent further upward movement of the gauge rod or the pump plunger which is locked thereto. At this point the plunger and gauge rod will have been moved into the position illustrated in phantom at the top of FIG. 2. It will be seen that in this uppermost position the block or lateral extension 61 will have been moved upwardly a distance Y 1 , which is equal to the vertical displacement Y 2 of the bottom of the plunger 24. Thus the present invention operates to precisely meter the amount of fluid dispensed from a container or the like during each stroke of the pump 21 of the device. It is to be noted that the markings 52 on the gauge rod 51 vary from the largest number at the top to the smallest number at the bottom, inasmuch as the further the gauge rod is moved through the lateral extension 61 before locking the gauge rod therein, the shorter the possible stroke of the pump plunger. It will be appreciated that the pump plunger 24 fits the barrel 22 quite snugly so that the plunger moves axially in a straight line and with the gauge rod attached to the plunger it follows that the gauge rod must move the same way so that no misalignment of pump plunger and gauge rod is possible. The present invention provides a particular improvement in liquid dispensers wherein the reproducibility of successive predetermined like dispensations of fluid is improved. Furthermore, the present invention provides an improvement in the device structure wherein prior art difficulties of mounting a gauge rod vertically above a container cap are overcome.
Although the present invention has been described with respect to a single preferred embodiment thereof, it will be apparent to those skilled in the art that numerous modifications and variations are possible within the scope of the present invention and thus it is not intended to limit the invention to the precise terms of description or details of illustration.
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A liquid dispenser adapted to fit over the open top of a container has a pump plunger connected by valving between a depending inlet and an outlet for pumping liquid from the container and a limitedly movable gauge rod is disposed in spaced parallel relation to the plunger with means securing the plunger and rod together in adjustable longitudinal relation to thereby adjustably fix the plunger stroke for metering fluid dispensed per stroke of the plunger.
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BACKGROUND OF THE INVENTION
[0001] 1. Field of the Invention
[0002] The present invention relates to mounting PC (personal computer) expansion cards or covers into computer case slots provided for same and more particularly to clips for easing such mountings by obviating the need for screws to retain the expansion cards or covers on said slot.
[0003] 2. Description of the Prior Art
[0004] Most PCs are bought with a limited number of functions. Extra functions such as modems, sound cards, math co-processor cards etc. may be added later by inserting an expansion card having the desired function into an expansion slot found at the back of the PC case. This expansion slot may be vertical or horizontal and is usually covered with a blank cover screwed to the PC case.
[0005] Referring to FIG. 1 it will be seen that the typical PC case ( 10 ) has a series of expansion slots ( 12 ) formed at the rear ( 14 ) of the PC case ( 10 ). These slots ( 12 ) extend from a ledge ( 16 ) and have a top opening ( 18 ) perpendicular to the slots ( 12 ). A series of circular holes ( 20 ) are centrally located at the end of each top opening ( 18 ). The opening ( 18 , 12 ) are usually covered with blank covers ( 22 ) having a narrow tip ( 24 ) and a right angle leg ( 26 ) with a hole ( 28 ) therein. The tip ( 24 ) is inserted into a slot ( 30 ) with the cover ( 22 ) extending over opening ( 12 ) and the leg ( 26 ) extending over opening ( 18 ) and with the hole ( 28 ) being aligned with the ledge hole ( 20 ). A screw ( 32 ) is screwed into the ledge ( 18 ) through the hole ( 28 ) and may be extended to the hole ( 20 ) to positively lock the cover ( 22 ) over the expansion slot ( 12 ). This procedure is done for all the expansion holes in the initial manufacture of the PC.
[0006] When an expansion card ( 34 ) is needed, one cover ( 22 ) is removed from the conforming expansion slot and the expansion card ( 34 ) is located therein. Since the card ( 34 ) is typically mounted to a cover plate similar in construction to the plate ( 22 ) the prime numbering has been retained for similar parts of the expansion card and the blank cover. The insertion of the card ( 34 ) and cover ( 22 ′) is as was described earlier for cover ( 22 ).
[0007] Since the holes ( 28 , 20 ) are small, as is the screw ( 28 ), alignment and threading of the screw ( 28 ) into the aligned holes is time consuming and difficult with the screw usually falling into the PC case components and having to be fished out of there.
[0008] What the prior art lacked was a simple method of retaining expansion cards and blank covers in the PC case.
SUMMARY OF THE INVENTION
[0009] The present invention solves the problems associated with prior art cover retaining means and others by providing two different types of clips for retaining an expansion card or a blank cover in the computer case without the use of screws. In one embodiment a clip mountable to the PC case is used for retaining either a prior art screw type blank cover ( 22 ) or an expansion card ( 34 ) for the PC over an expansion slot by snapping a flexible tip of the PC clip into the screw hole found in both prior art blank covers and expansion cards.
[0010] In a second embodiment the clip is made integral with the blank cover or expansion card. The clip includes a spring leg portion formed from the elongated clip body at the top of the clip but below the angled short leg portion of the clip to allow the clip to capture the computer case between the short leg portion and the spring leg portion. The spring leg portion presses against the computer case and is disengaged by pushing it forward from engagement with a tool inserted through a slot in the clip.
[0011] In view of the foregoing it will be seen that one aspect of the present inventions is to provide a means for mounting a PC expansion card or expansion slot cover over an expansion slot in the PC without the use of screws.
[0012] Another aspect is to provide a clip, which is easily mounted to a PC case to retain either PC expansion cards or blank expansions slot covers during the initial manufacture of the PC.
[0013] Yet another aspect is to provide an integral clip and expansion card cover, which is easily mounted to a PC case without the use of screws.
[0014] Still yet another aspect is to provide an integral clip and blank expansion slot cover which is easily mounted to a PC case without the use of screws.
[0015] These and other aspects of the present invention will be more fully understood after a review of the following description of the preferred embodiment when considered with the accompanying drawings.
BRIEF DESCRIPTION OF THE DRAWINGS
[0016] In the drawings:
[0017] [0017]FIG. 1 is a perspective view of prior art PC expansion card and expansion slot cover mountings;
[0018] [0018]FIG. 2 is an expanded perspective view of the PC clip of the present invention mounted to a PC case for retaining either a PC expansion card or expansion slot cover;
[0019] [0019]FIG. 3 is a perspective view of the PC clip of the present invention;
[0020] [0020]FIG. 4 is a front view of the PC clip of FIG. 3;
[0021] [0021]FIG. 5 is a side view of the PC clip of FIG. 3;
[0022] [0022]FIG. 6 is a top view of the PC clip of FIG. 3;
[0023] [0023]FIG. 7 is a perspective view of the integral clip and blank expansion slot cover of the present invention;
[0024] [0024]FIG. 8 is a perspective view of the integral clip having a cutout for an expansion card to be mounted therein;
[0025] [0025]FIG. 9 is a top view of the integral clip of FIG. 8;
[0026] [0026]FIG. 10 is a side view of the FIG. 8 clip;
[0027] [0027]FIG. 11 is a side view of the FIG. 8 clip having an expansion board mounted thereto; and
[0028] [0028]FIG. 12 is a perspective view of the FIG. 11. clip mounted to a computer case.
DESCRIPTION OF THE PREFERRED EMBODIMENT
[0029] Referring now to FIGS. 2 - 6 , one embodiment of a computer expansion slot clip is shown which requires no screws to mount the clip to the computer case. It will be understood that while the reference is to a single slot cover or PC clip ( 35 ), a plurality of same could be mounted to a plurality of expansion slots in a similar manner.
[0030] The clip ( 35 ) has a curved portion ( 36 ) folded back over a top ledge portion ( 38 ) to form a pocket ( 40 ) there between for retaining the ledge ( 16 ) portion of the PC case ( 14 ) directly behind one of the openings ( 18 ). A backplate ( 42 ) extends at a right angle up from the ledge portion ( 38 ) and is made to rest up against the PC case ( 14 ) with the ledge ( 16 ) open portion extended inside the pocket ( 40 ). The curved portion ( 36 ) has an angled tip ( 44 ) formed therein angled to bend down when the ledge ( 16 ) is inserted into the pocket ( 40 ) to be easily fitted into the pocket ( 40 ). However, the tip ( 44 ) will be bent up with any attempt to remove the ledge ( 16 ) from the pocket ( 40 ) causing interference for any attempted removal of the ledge ( 16 ).
[0031] The width W of the pocket ( 40 ) is made to be the same or slightly smaller than the width of the openings ( 18 ) to allow the capture of the ledge ( 16 ) portion behind the opening ( 18 ).
[0032] A flexible wing portion ( 46 ) is formed from the back plate portion ( 42 ) and the ledge portion ( 38 ) leaving a right angle opening ( 48 ) therein. The wing portion ( 46 ) is formed as an angled portion ( 50 ) having a straight leg portion ( 52 ) extending down therefrom and having a tab ( 54 ) at the end of the straight leg ( 52 ). The angled portion ( 50 ) extends away from the backplate portion ( 42 ) sufficiently to have the tab ( 54 ) align with one of the holes ( 20 ) when the clip ( 35 ) is properly fitted to the case ( 14 ).
[0033] Now, with the PC clip ( 35 ) properly installed, either during initial manufacture of the PC or as a retrofit, when either a blank cover plate ( 22 ) or a PC expansion card ( 22 ′) is installed into one of the openings ( 12 ) having a clip ( 34 ) mounted therein, the leg portion ( 26 , 26 ′) is aligned to have the tab ( 54 ) in line with the opening ( 28 , 28 ′). It is then pushed against the straight leg portion ( 52 ) moving it back until the restoring force of the spring in the flexible member ( 46 ) overcomes the pushing force and the tab ( 54 ) is pushed into the opening ( 28 , 28 ′) which is aligned with one of the holes ( 20 ). To disengage, the leg portion ( 52 ) may be raised out of the hole ( 28 ) releasing the cover plate or expansion card ( 22 , 22 ′). Alternately, the card or plate may be forced back until the tab is disengaged from the hole.
[0034] Referring now to FIGS. 7 - 12 generally, a second embodiment of the computer clip is shown. This embodiment provides a one piece or integral clip and expansion slot cover again requiring no screws to fasten it to the computer case.
[0035] Referring now to FIG. 7, an integral computer expansion slot cover ( 60 ) is shown which is similar to the prior art slot cover ( 22 ) except that it uses an integral clip assembly ( 62 ) to mount the cover to the computer case ( 14 ) instead of the screws ( 32 ). The slot cover ( 60 ) has a bottom leg portion ( 64 ), which is fitted into an opening ( 30 ) to cover one slot ( 12 ). The body ( 66 ) is then swung up toward the opening ( 12 ) until the assembly ( 62 ) is clamped onto the ledge ( 16 ) of the computer case ( 14 ). The cover ( 60 ) has a pair of dimples ( 68 ; 70 ) near the top of the cover ( 60 ), which fit into the edges of the opening ( 12 ) to position the cover properly over the slot ( 12 ). The clip assembly ( 62 ) comprises a flexible tab member ( 72 ) formed from the body ( 66 ) of the cover ( 60 ) to have a bent leading edge ( 74 ) which allows easy insertion of a top tab ( 76 ) of the clip ( 60 ) to easily fit over the top of the ledge ( 16 ) of the case ( 14 ) with the tab ( 74 ) fitting under the ledge ( 16 ). To release the clip ( 60 ), the tab member ( 72 must be pushed back with a screwdriver tip extended through an opening ( 75 ) to disengage the ledge ( 16 ) and allow the clip ( 60 to be removed.
[0036] Turning to FIGS. 8 - 12 , the clip ( 60 ) is shown to be modified to mount an expansion card ( 78 ) having an external to the computer case signal connection ( 80 ) mounted thereto. To accomplish this, a cutout ( 82 ) is formed in the body ( 66 ) of the cover ( 60 ). Since the operation of this modified cover is identical to the previously described cover ( 60 ) identical parts of this modified cover ( 60 ′) will be identified with a prime of the previous number used for the cover ( 60 ).
[0037] As can be best seen in FIGS. 11 - 12 , the expansion card ( 78 ) is maintained inside the computer case while the signal connection ( 80 ) is external thereto when the cover ( 60 ′) is snapped into the computer case over the proper expansion slot.
[0038] Certain modifications and additions will occur to those skilled in the art area upon reading this disclosure. It will be understood that all such were deleted herein for the sake of conciseness and readability but are intended to fall within the scope of the following claims.
[0039] As an example, the clip ( 35 ) can be fitted to expansion slots having no holes ( 20 ) in the case area around the slot ( 18 ) and will still capture expansion cards and slot covers which are formed with a hole for mounting to the expansion slot with a screw. Also, it may be possible to form the covers ( 60 ; 60 ′) from an appropriate plastic material having sufficient strength and flexibility for the tab ( 74 ; 74 ′).
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An integral spring clip and computer slot cover is disclosed for mounting over an expansion slot of a PC. The cover has an integrally formed spring clip assembly for capturing a ledge of the PC case over an expansion slot therein at one end and means formed at an opposite end of said cover assembly for retaining that end of said cover assembly to the computer case to allow either a slot cover to be mounted over the slot without the use of screws or to mount an expansion card therein by mounting the card through an opening formed in the cover assembly.
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TECHNICAL FIELD
The invention relates generally to electrical components, more particularly to electrical connectors, and even more particularly, to through-board female headers with integral solder masks enabling access to the header contacts from both sides of the board.
BACKGROUND
The use of mass soldering techniques to attach electrical components to a common support structure is well known. One exemplary process is that known as wave soldering; others are known. One common support is a printed circuit board; others are known. Various types of electrical components, such as connectors, sockets and the like, provide interconnecting electrically conductive paths on or in a printed circuit board. These components electrically interconnect other electrical components or elements, such as resistors, capacitors, conductors, transistors, integrated circuits, etc.
The invnetion is described below with reference to a female type header that provides a socket for receiving pin contacts from another connector or other component for connecting the same to circuits on a printed circuit board. The description is directed to use of such a header and circuit board in a wave soldering process. However, it will be appreciated that the features of the invention may be used in connection with other types of components, other types of common support structures, other types of mass soldering techniques, and so on.
In a typical process for manufacture circuitry employing a printed circuit board with components mounted on the board and wave soldered, the leads or solder tails (hereinafter simply referred to as solder tails) of electrical components are positioned in respective holes, preferably plated-through holes, in the printed circuit board. The plating in the holes is electrically connected to respective conductive paths or the like, printed on or otherwise formed with respect to the printed circuit board. The printed circuit board is passed through a molten solder wave that wipes against a surface of the printed circuit board to solder the connections between the solder tails and plated-through holes or other conductive paths or the like on the board.
Usually, some of the solder flows into the plated-through holes. Ordinarily, any space left between a lead and a plated-through hole would be expected to be filled with solder.
SUMMARY OF THE INVENTION
According to the present invention, an electrical component is provided with features that enable solder tails or the like to be attached to plated-through holes of a printed circuit board while those holes are occupied both by solder tails and by a mask that prevents molten solder from completely filling the hole. During wave soldering, adequate solder is provided to effect soldering of the solder tails to the conductive material (plating) in the holes and/or on the top or bottom of holes, while the mask prevents the hole from filling with molten solder. Preferably, the mask is frangibly attached to a major body portion of the component so that the mask subsequently can be removed, thus providing an open space in the hole. The open space in the hole permits a pin contact or the like to be inserted to engage the contacting portion of the component contact from the solder tail side of the printed circuit board.
Further, in accordance with the invention there is provided an electrical component to be mounted to a circuit board, comprising: an electrically insulating body for supporting an electrically conducting member to be soldered to a conductive path on a circuit board; a solder mask extending from one side of the body to be inserted in a hole in the circuit board for occupying space in the hole in the circuit board during soldering of the conductive member to the conductive path on the circuit board; and a frangible connection for securing the solder mask to the body until the conducting member is soldered to the conductive path on the circuit board and for permitting detachment of the solder mask from the body after such soldering and removal of the solder mask from the body hole thereby to provide an open space in the hole through which access may be had from one side of the board to the opposite side of the board such as for insertion of a terminal therethrough.
Also provided by the invention is an electrical component to be mounted to a circuit board, comprising: an electrically nonconducting body having a cavity and an opening at one side of the body for permitting access to the cavity; an electrically conducting member mounted within the cavity, the electrically conducting member including a solder tail extending through the opening and from the one side of the body for inserting into a hole in a circuit board and for electrically connecting with a conductive path on the circuit board by soldering; a mask proximate the opening for blocking flow of molten solder through the opening for preventing solder from filling the cavity; and frangible connecting means for connecting the mask to the body until the solder tail is soldered to the conductive path on the circuit board and for permitting detachment of the mask from the body after such soldering thereby to open the opening for providing access to the cavity from the one side of the body.
The invention also provides a method of mounting a female header on a circuit board for access to the header from either side of the board after mounting, the header including an electrically nonconducting body, an electrically conducting member having a solder tail, such member being partially disposed within a cavity in the body, the solder tail extending through an opening in the body and a solder mask extending from the body proximate the solder tail and partially blocking the opening, said method comprising: inserting the solder tail and solder mask into a hole in the circuit board from the top surface of said board, the board including a solderable contact in or proximate the hole; applying molten solder to the board and solder tail to interconnect the solderable contact and tail with solder; and detaching the solder mask from the body to give access to the electrically conducting member through the hole and opening.
With the foregoing in mind, one aspect of the invention relates to an electrical component including an electrically nonconducting body, a cavity in the body containing at least part of an electrically conducting member therein, an opening in the body for access to the cavity, a mask for preventing flow of molten solder or the like, and a frangible connecting mechanism to connect the mask to the body.
According to another aspect, the aforementioned electrical component is in the form of a female header having plural openings and contacts therein with solder tails extending from the openings. The mask is in the form of plural pin-like masks that extend generally parallel to respective solder tails.
According to still another aspect, the contacts of such an electrical component are box-type contacts, and the cavity has openings at opposed ends so that the contacting portions of respective contacts can be engaged by a member inserted from either end of the cavity.
According to still another aspect, the invention relates to the combination of an electrical component of the type described together with a printed circuit board enabling a contact of the component to be engaged from either side of the printed circuit board.
The foregoing and other objects, aspects, features and advantages of the present invention will become further apparent from the following description with reference to the accompanying drawings.
To the accomplishment of the foregoing and related ends, the invention, then, comprises the features hereinafter fully described in the specification and particularly pointed out in the claims, the following description and the annexed drawings setting forth in detail certain illustrative embodiments of the invention, these being indicative, however, of but several of the various ways in which the principles of the invention may be employed.
Although preferred embodiments of the invention are disclosed, it will be appreciated that the scope of the invention is to be determined by the scope of the claims.
BRIEF DESCRIPTION OF THE DRAWINGS
In the annexed drawings:
FIG. 1 is an isometric view of an electrical component in accordance with the invention in the form of a through-board female header positioned in a printed circuit board, part of the circuit board being broken away to show the solder tails and solder masks of the headers;
FIG. 2 is a fragmentary side elevation view of the header, partly broken away in section;
FIG. 3 is a fragmentary top view of the header of FIG. 2;
FIG. 4 is a fragmentary bottom view of the header of FIG. 2;
FIG. 5 is an end elevation view, partly in section, of the header of FIG. 2;
FIG. 6 is an end elevation view of a box contact used in the header, such contact being shown attached to a breakaway carrier strip for convenient manipulation;
FIG. 7 is a top view of the contact of FIG. 6 looking generally in the direction of the arrows 7--7;
FIG. 8 is an end elevation view of the contact of FIG. 6 looking generally in the direction of the arrows 8--8;
FIG. 9 is a fragmentary side view of a single row header with contacts therein;
FIG. 10 is an end view of the header of FIG. 9;
FIG. 11 is a schematic bottom view of the header of FIG. 9 showing positioning of the solder tails and solder masks as they would appear in plated-through holes of a printed circuit board;
FIG. 12 is a side elevation view of a dual in-line row header according to the invention, partly in section;
FIG. 13 is a top view of the header of FIG. 12;
FIG. 14 is a bottom view of the header of FIG. 12;
FIG. 15 is an end view, partly in section, of the header of FIG. 12;
FIG. 16 is a fragmentary side view of a dual in-line row header with contacts therein;
FIG. 17 is an end view of the header of FIG. 16; and
FIG. 18 is a schematic bottom view of the header of FIG. 16 as the solder tails and masks would appear in plated-through holes looking from the bottom of a printed circuit board into which the header is inserted.
DESCRIPTION OF THE PREFERRED EMBODIMENTS
Referring now in detail to the drawings, wherein like reference numerals designate like parts in the several figures, and initially to FIG. 1, an electrical component in the form of a through-board female header with integral solder masks is generally designated 10. The header 10 is shown in FIG. 1 mounted with respect to a printed circuit board 12 for the purpose of providing electrical connections between electrically conductive paths (not shown) on or in the board and further electrically conductive members that are inserted to engage respective contacts 14 of the header. The contacts accordingly have solder tails 16 that are attached by solder to electrically conductive plating in plated-through holes 18 of the printed circuit board. Advantageously, as will become apparent from the following description, using pin-like solder masks 20 of the header 10 to occupy some of the area not occupied by a solder tail 16 in a plated-through hole prevents molten solder from fully filling such hole. After removal of the solder mask, a contacting portion 22 of the contact may be engaged by an external member inserted with respect to header 10 and board 12 from either side, i.e., from either the top or bottom thereof, as is illustrated in FIG. 1.
The ability to make connections with the contacting portions 22 of the header 10 from either or both sides thereof, and from either or both sides of the printed circuit board 12, facilitates stacking of boards and/or making connections with boards in dense packing of the boards and/or circuits thereon. In connection with stacking of boards, it will be appreciated that one or more printed circuit boards 12 having headers 10 thereon may be stacked on a single group of pin contacts supported from a main mother board or the like.
Referring to FIGS. 1-5, the header 10 includes an electrically nonconductive or insulator body 30. The body has exterior side surfaces 32, 34, end surfaces 36, 38, top 40 and bottom 42. The body 30 may be made by plastic injection molding techniques. Exemplary material of which the body 30 may be made includes Rynite FR530 which is a glass filled PTE (polyethylene teraphthalate) polyester available from E.I. DuPont de Nemours and Company of Wilmington, Del.
Within the body 30 are a plurality of cavities 44 that extend through the body. Openings 46 in the top 40 permit access to the cavities from the top of the header. The openings generally indicated at 48 are provided for access to the bottom of the cavities 44. Shelf walls 50 in each cavity may be provided to aid in properly positioning respective contacts 14 during their insertion into the cavities in the desired relation to the body 30. Shelves 50 preferably include oblique surfaces 51 facing toward opening 46 for guiding contacts 14 into the proper location in cavity 44.
Covering at least part of the bottom openings 48 are a plurality of pin-like solder mask members 20. Each solder mask member is elongate; preferably the length is adequate to extend fully through and partly beyond a plated-through hole 18 of the printed circuit board 12. The cross-sectional shape of the solder mask pins 20 may be uneven, octagonal, as seen in FIG. 4, for example. The mask pins 20 are attached to the body 30 in proximity to respective openings 48 to cover at least part of such openings while providing a clearance 52 on both sides of the mask. The clearances 52 are sufficiently large to receive therethrough respective solder tails 16, on the one hand, and are sufficiently small to tend to block the flow of molten solder into respective cavities 44, especially during wave soldering, on the other hand. The flowing of molten solder into such cavities 44 could impede proper operation of the contacting portiton 22 of respective contacts 14 and/or could tend to block access to such contacting portions, particularly from the bottom thereof.
A frangible connection 54 is provided for each of the mask pin members 20. The frangible connection is formed by a directly molded piece of plastic or like material of which both the body 30 and pins 20 are made during a single injection molding process, for example. The frangible connection or connection material 54 preferably is at two sides of each pin 20. The frangible connection preferably is sufficiently strong to retain the mask pins 20 attached to the body 30 in position, as is illustrated, blocking the openings 48, while being sufficiently weak to permit breaking thereof for removal purposes. Breaking of the frangible connections 54 and removal of mask pins 20 may be effected by inserting a pin-type tool or pin-like contact member into the cavity 44 from the top opening 46 and pressing the same against the top 56 of the mask pin intended to be removed. A recess, groove or guiding slot 58 is provided in top 56 to guide such a tool generally to apply force evenly to a mask pin 20 to fracture both frangible connecting members 54 of a respective mask pin substantially simultaneously.
Preferably the plated-through holes 18 are larger than those typically found in printed circuit boards. Such larger size is provided to accommodate both the solder tails 16 and solder mask pins 20 therein. Additionally, at the bottom 42 of the header body 30, stand-offs 60 are provided for the usual purposes of maintaining bottom 42 of header 10 slightly spaced away from the top surface of the printed circuit board, for example, for cleaning, for heat dissipation, and so on.
Referring to FIGS. 6-8, an exemplary contact 14 is shown in detail. The contact includes a solder tail 16 and a contacting portion 22. The top end of the contact 14 is attached at a breakaway or frangible connection 62 to a carrier strip 64 which is provided to support a plurality of contacts for convenience of handling the same and inserting them simultaneously into the insulator body 30. The contacting portion is in the form of a box-type contact having a pair of arms or tines 66 with wiping portions 68 intended to wipe against a pin contact or the like inserted in engagement therewith. Near the top of the arms 66 is a sharp, spike-like protrusion 70 intended to bite into a wall of a respective cavity 44 to lock the respective contact in position in the cavity. Ordinarily, such positioning results in the top 72 of the contact being generally parallel to the top surface 40 of the insulator body 30.
Contact 14 includes a generally linear support structure 74 with a pair of protruding arms 76 that may cooperate, for example, with the shelves 50 in the cavity 44 to position contact 14 during insertion of the contact into the cavity. The lower surfaces of arms 76 may slide on oblique surfaces 51 of shelves 50 to guide contact 14 for proper seating in cavity 44. At the bottom end of the support structure 74 is the solder tail 16. Solder tail 16 preferably is relatively wide and flat, as is illustrated, so as to fit in the clearance area 52 at the bottom of the header body 30 and to fit properly into a plated-through hole 18 of the printed circuit board 12.
The header 10 may be made by molding the insulator body 30, forming the contacts 14 in the manner illustrated, and then inserting the contacts with respect to the cavities 44. Insertion ordinarily would take place by inserting the solder tails 16 into the top openings 46; continuing to insert the solder tails 16 through respective clearance areas 52, and finishing the insertion with the arms 76 resting at the bottom of cavity 44. During the insertion, the barb or point 70 will bite into the side wall of the cavity 44 inhibiting withdrawal of the contact from the cavity. Preferably, the contact is pressed down into the cavity far enough so that the top 72 is generally parallel to the top 40 of the insulator body 30. After a plurality of contacts 14 carried by a carrier strip 64 have been so inserted into the insulator body 30, the strip 64 can be broken away and discarded.
Briefly referring to FIGS. 9 and 10, as well as to FIG. 1, the relative positioning of the contacts, particularly the solder tails 16, relative to the insulator body 30 and the solder mask pins 20 thereof may be seen. The header 10 is shown as a single row header having a single row of contacts. The number of contacts in the row may vary, depending on the need, from only one to more than forty. As illustrated in FIGS. 9-11, the position of solder tails 16 with respect to mask pins 20 may vary. In those Figures, every other solder tail along the row of mask pins is disposed on an opposite side of a mask pin 20. The staggered solder tail arrangement adds to the mechanical stability of header 30 when mounted in resisting bending moments.
FIG. 11 is a view looking up from the botttom of the printed circuit board 12. The margin 80 of two plated-through holes 18 is shown. The position of the solder mask pin member 20 in the holes 18 and the relative position of the solder tails 16 also are shown. Desirably, adequate space is provided at 82 to perit molten solder to flow during wave soldering to effect a solder connection of the solder tail 16 to the electrically conductive plating material or the like in the hole 18. What happens on the other side of the hole in the space not occupied by a solder tail is immaterial to the operation and advantages of the invention. Importantly, though, a large amount of space is occupied by the solder mask pin member 20 so that when member 20 is removed in the manner described above, an open area is provided in the hole 18 large enough to accommodate a pin contact intended to be inserted therethrough.
Turning briefly to FIGS. 12∝18, a dual in-line row configured header 10' is illustrated. FIGS. 12-18 are analogous to FIGS. 2-5 and 9-11, respectively. The header 10' and those various parts thereof illustrated in FIGS. 12-18 that correspond to those described above with reference to the header 10 and FIGS. 2-5 and 9-11 are identified with the same reference numerals, but with ' designations. Thus, for example, the header 10' includes an insulator body 30', electrical contacts 14', etc. The arrangement of the cavities 44' in the header 10' and of the contacts 14' associated with such cavities is in dual in-line configuration, a configuration that is well known in the electronics industry. The functioning of the various elements of FIGS. 12-18 is entirely analogous to their counterparts in FIGS. 2-5 and 9-11. Regardless of whether header 10 or 10' is used, a printed circuit board or other support is prepared to receive the header by opening an appropriate number of appropriately spaced holes, each large enough to receive a combined solder tail 16 or 16' and mask pin 20 or 20' in the board. Each hole is either through-plated with a metal or is disposed adjacent a solderable contact on the bottom side of the board. The tails and pins are inserted mechanically into the holes from the top side of the board. The solder tails are subjectd to wave soldering so that mechanical and electrical bonds between the header solder tails and the solderable contacts on the printed cicuit board or other support are formed. Components may be readily connected to the header through its top surface 40 or 40' to connect with one of contacts 14 or 14'. At the contacts 14 or 14' where it is desired to make an electrical connection from the bottom side of the board or support, mask pins 20 or 20' are detached from body 30 or 30'. For example, a tool may be inserted through the openings 46 or 46' opposite the mask pins that are to be removed and the frangible connecting members 54 or 54' detached to open the selected cavities 44 or 44' for access from the bottom side of the board or support. Only those mask pins were connections are to be made from the bottom side of the board need to be broken away. While the depicted headers include a mask pin next to each solder tail, headers according to the invention may include some solder tails that lack corresponding mask pins.
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An electrical component for electrical interconnection of electrical elements includes an electrically non-conducting body containing at least one cavity for receiving an electrically conducting member, an opening for access to the cavity, a solder mask disposed proximate the opening for preventing the flow of molten solder through the opening and a frangible connection between the mask and the body. An electrical contacting member disposed within the cavity, preferably through a second opening, includes a solder tail that passes through the opening adjacent the mask. The component, containing the contacting member, is disposed on the top side of a printed circuit board with the solder tail, and preferably the mask, inserted into a plated-through hole in the board and protruding from the bottom side of the board. The solder tail is soldered to the board in a wave soldering process during which the mask prevents molten solder from entering the cavity. Thereafter, the solder mask may be removed by breaking the frangible connection so that an electrical lead can be inserted into the cavity from the bottom side of the board.
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BACKGROUND OF THE INVENTION
1. Field of the Invention
The present invention is related to high-throughput discrete-time systems with parallel pipelined architectures, and more particularly, to high-speed analog front-end circuits, such as time-interleaved analog-to-digital converters and to programmable gain amplifiers that precede the analog-to-digital converters.
2. Related Art
Many modern data communications systems use parallel pipelined architectures in order to increase the data throughput. In essence, this approach utilizes a number of identical pipelined sub-circuits arranged in parallel. Another term for this architecture is “time interleaving.”
FIG. 1A illustrates a conventional time interleaved analog-to-digital converter (ADC). As shown in FIG. 1A , an analog voltage V a is sampled by track-and-hold amplifiers 102 A– 102 P. The track-and-hold amplifiers 102 A– 102 P are clocked by clocks f adcA –f adcP , as shown in the figure. The outputs of the track-and-hold amplifiers 102 A– 102 P are inputted to sub-analog-to-digital converters 104 A– 104 P, and then to encoders 106 A– 106 P. Demultiplexers 108 A– 108 H input the multiple-phase output digital signals representing a digitized version of the input analog voltage V a of the corresponding encoders 106 A– 106 P, and output a number of single-phase digital signals, each at a lower rate.
FIGS. 1B–1C illustrate a generalized phase relationship of conventional parallel pipelined circuits. FIG. 1B shows a conventional pipelined parallel operation of either an analog or a digital circuit. Shown in FIG. 1B are three stages “a”, “b” and “c” of a device, with each stage having 3 sampling devices M (Ma, Mb, Mc), 3 analog or digital circuits A (Aa 0 –Aa 2 , Ab 0 –Ab 2 , Ac 0 –Ac 2 ), clocked by the clock signals f 0 –f 2 (note that only 3 devices in each stage are shown), with the data outputs sa 0 –sa 2 , sb 0 –sb 2 , sc 0 –sc 2 . Clocked sampling devices Mx are necessary. Common examples of Mx are track-and-hold (T/H) in the analog domain and D flip-flop (DFF) in the digital domain. FIG. 1C shows a relationship between the clock phase and signal phase—in other words, the clock is a multiple phase single rate clock.
The problem with this approach is that the slow running block in the backend limits the system clock frequency. The circuit bandwidth of the Ax blocks naturally reduces from the front-end to the backend as the block functionality increases toward the backend. However, the front-end bandwidth can not be scaled-down to match the slow clock, because the front-end has to track the fast varying signal, and/or the matching or noise (kT/C) requirements may prevent the scaling. The front-end is usually the bottleneck in mismatch and noise because of the signal amplification in the front-end stage.
More granularity in the clock rate is therefore needed to improve the efficiency for a given throughput. Accordingly, there is a need in the art for high bandwidth architectures that utilize an architectural approach to solving the bandwidth problem.
SUMMARY OF THE INVENTION
The present invention relates to a hierarchical pipelined parallel operation of analog/digital circuits that substantially obviate one or more of the disadvantages of the related art.
More particularly, in an exemplary embodiment of the present invention, a hierarchical pipelined parallel circuit includes a first stage comprising a first plurality of sampling devices and a plurality of corresponding analog circuits receiving an analog voltage; a second stage comprising a second plurality of sampling devices and a plurality of corresponding analog circuits receiving outputs from the first stage; and a multi-frequency multi-phase clock for the first and second stages. The clock frequency multiplied by the number of parallel devices in each stage is the throughput of the circuit and therefore should preferably be kept constant across the stages. The number of devices in the second stage is greater than the number of devices in the first stage, and the second frequency is lower than the first frequency. Phases of the clocks for the devices in each of the stages are related to each other by 360°/number of devices in each stage.
In another embodiment, a hierarchical pipelined parallel circuit, includes a first stage with a plurality of sampling circuits and a plurality of corresponding analog circuits that receive an output from the plurality of sampling circuits. A second stage includes a second plurality of sampling circuits and a plurality of corresponding analog circuits that receive an output from the plurality of sampling circuits. A multi-frequency, multi-phase clock clocks the first and second stages, the multi-frequency, multi-phase clock providing a first clock having a first frequency having a single or plurality of phases and a second clock having a second frequency having a plurality of phases. The number of devices in the second stage is greater than the number of devices in the first stage. A first phase of a plurality of phases is phase locked to the first phase of the first clock. The second frequency is lower than the first frequency. The clock frequency multiplied by the number of parallel devices in each stage is the throughput of the circuit and therefore should preferably be kept constant across the stages. Phases of the clocks for the devices in each of the stages are related to each other by 360°/number of devices in each stage. The phases can be equally spaced around 360°. The phases can be unequally spaced around 360°. The hierarchical pipelined parallel circuit can be an analog circuit. The hierarchical pipelined parallel circuit can be an analog to digital conversion circuit. The plurality of sampling circuits can be sample-and-hold circuits and the analog circuit is a programmable gain amplifier (PGA) preceding a time-interleaved ADC array.
In another embodiment, an analog-to-digital converter includes N track-and-hold amplifiers inputting an analog voltage and sampling the analog voltage using a N-phase clock; M sub-analog-to-digital converters receiving voltages from the track-and-hold amplifiers and sampling the voltages using an M phase clock having a frequency N/M compared to the N-phase clock; P encoders receiving outputs of the sub-analog-to-digital converters and encoding the outputs using a P phase clock having a frequency M/P of the compared to the M phase clock; and R demultiplexers retime the P different phase outputs from the P encoders and outputting R single-phase digital outputs representing the analog voltage and having a rate P/R each compared to the P-phase clock. In one embodiment, M/N=2. In one embodiment, P/M=2. In each signal path following the track-and-hold amplifiers, there is a programmable gain amplifier. In each signal path to each sub-analog-to-digital converter, a track-and-hold amplifier is clocked by the same clock as its corresponding sub-analog-to-digital converter, and there is a second programmable gain amplifier. In each signal path to a corresponding encoder, there is a D flip-flop for each encoder input bit signal clocked by the same clock as the corresponding encoder. In each signal path following a corresponding encoder, there is a D flip-flop for each encoder output bit signal clocked by the same clock as the corresponding encoder. In half of the signal paths following the encoders, there is a delay latch following the encoder output D flip-flop and clocked by the same clock as the corresponding encoder.
Additional features and advantages of the invention will be set forth in the description that follows, and in part will be apparent from the description, or may be learned by practice of the invention. The advantages of the invention will be realized and attained by the structure particularly pointed out in the written description and claims hereof as well as the appended drawings.
It is to be understood that both the foregoing general description and the following detailed description are exemplary and explanatory and are intended to provide further explanation of the invention as claimed.
BRIEF DESCRIPTION OF THE FIGURES
The accompanying drawings, which are included to provide a further understanding of the invention and are incorporated in and constitute a part of this specification, illustrate embodiments of the invention and together with the description serve to explain the principles of the invention. In the drawings:
FIG. 1A illustrates a conventional time interleaved ADC.
FIGS. 1B–1C illustrate a generalized phase relationship in of conventional parallel circuits.
FIGS. 2–3 illustrate a generalized embodiment of the present invention.
FIG. 4 illustrates an exemplary programmable gain amplifier embodiment of the invention.
FIG. 5 illustrates an exemplary analog to digital converter embodiment of the invention.
FIGS. 6A–6B illustrate how a multi-phase multi-frequency clock can be generated and used.
FIG. 6C illustrates how the multi-phase parallel signals are retimed to a single phase.
FIG. 7 illustrates the interleaving approach between the second stage and the third stage of the ADC hierarchy.
FIG. 8 illustrates how the signal travels from a first stage of the ADC hierarchy to the second stage of the ADC hierarchy.
DETAILED DESCRIPTION OF THE INVENTION
Reference will now be made in detail to embodiments of the present invention, examples of which are illustrated in the accompanying drawings.
FIG. 2 shows the present invention in a generalized form. Shown in FIG. 2 are two stages “a” and “b” (of what can be a parallel hierarchy with more than two stages) of a device, with each stage having sampling devices M (Ma, Mb), analog or digital circuits A (Aa 0 –Aa 2 , Ab 0 –Ab 5 ), clocked by the clock signals fa 0 –fa 2 and fb 0 –fb 5 , with the data outputs sa 0 –sa 2 and sb 0 –sb 5 , as shown in the figure. It will be appreciated that the number of devices in each stage is not limited to what is shown in FIG. 2 .
The phase and frequency relationships between the various signals are illustrated in FIG. 3 .
FIG. 4 illustrates how the multi-frequency multi-phase clock approach of FIGS. 2–3 may be applied to a programmable gain array, which, for example, can be one element of an ADC. Shown in FIG. 4 is a first stage comprising track-and-holds 102 and driven by the track-and-hold clock f t/hA , f t/hB . Outputs of the track-and-holds 102 are inputted into coarse programmable gain amplifiers 402 A, 402 B, and then to a second stage. In the second stage, each signal path has its own track-and-hold 404 driven by a different clock of a frequency f, and phases A–D, and a follow-on fine PGAs 406 A–D.
This way, the back-end circuitry can be clocked at a lower speed, while the front-end circuitry can be clocked at a higher speed, while maintaining a high conversion speed of the overall ADC. It also means that the number of back-end devices in an ADC, such as encoders and demultiplexers, does not need to equal the number of front-end devices, such as track-and-hold amplifiers and ADCs. In other words, a hierarchical structure results. There are fewer elements on the front-end, and the number of elements grows as the signal moves through the stages towards the back-end. This has the advantage that power consumption and area is substantially reduced. Note also that the front-end circuitry tends to consume more power than the back-end, therefore, reducing the amount of front-end circuitry has a disproportionately beneficial effect on the overall power and area requirements of the device.
Another benefit of this approach is that mismatch between the signal lines, and the mismatch between the clock lines, can be reduced or eliminated. For example, with reference to conventional circuit shown in FIG. 1A , there may be mismatch between the signal going through the signal path of the track-and-hold 102 A, sub-ADC 104 A and encoder 106 A, and a signal going through the track-and-hold 102 P, ADC 104 P and encoder 106 P.
Another way of looking at this approach is that granularity of the overall structure is increased using the hierarchical approach by using a higher granularity of the clock frequency. Note also that the spacing of phases around the unit circle can be equally spaced, or can be unequally spaced. Thus, the number of devices in the second stage is greater than the number of devices in the first stage. Normally, in each stage, one of the phases is phase locked to a phase of the clock of the previous stage, while its frequency is slower than the frequency of the clock of the previous stage. A ratio of clock frequencies of the stages corresponds to a ratio of devices in the stages. Usually phases of the clocks for the devices in each of the stages are related to each other by 360°/number of devices in each stage.
The present invention will be further illustrated with reference to a pipelined ADC, which is a particular example of the pipelined hierarchical architecture illustrated in FIGS. 2–4 . Using the parallel pipelined concepts described above, the approach of the present invention is to divide the ADC into smaller blocks, so as to avoid the back-end bandwidth limitations, and to implement it by time-interleaving an array of pipelined analog or digital blocks. Clocked sampling devices are therefore used. Common examples of such devices are track-and-hold amplifiers in analog domain, and D flip-flops in the digital domain.
FIG. 5 illustrates one ADC-related embodiment of the present invention, which is a particular example of how the general principles described above with reference to FIGS. 2–4 can be applied. Shown in FIG. 5 is a hierarchical parallel structure of an analog-to-digital converter, which includes four track-and-holds 102 A– 102 D, eight sub-ADCs 104 A– 104 H, sixteen encoders 106 A– 106 P and eight demultiplexers 108 A– 108 H. It will be appreciated that the number parallel channels, as well as the hierarchical ratios between the stages, are exemplary.
An analog signal V a is sampled by four track-and-hold amplifiers 102 A– 102 D. The sampling is performed at different phases. The clock signals provided to the track-and-hold amplifiers 102 A– 102 D are spaced apart from each other by 90°, or one quarter of the period (here, 360° divided by the number of track-and-hold amplifiers). This is an example of time interleaving. Note that the clock frequencies f t/h –f t/hD supplied to the track-and-hold amplifiers 102 A– 102 D are the same, but the phase is different. The outputs of the track-and-holds 102 A– 102 D are then split, in this case into two signals 110 A, 110 B that are fed into two sub-ADCs. For example, taking the case of the track-and-hold 102 A, its output ( 110 A, 110 B) goes to sub-ADC 104 A and sub-ADC 104 B. The two sub-ADCs 104 A, 104 B are clocked at half the frequency of the track-and-hold, and their clock waveforms f adcA , f adcB are at 180° relative to each other. In other words, the phases of the clocks of the two sub-ADCs 104 A, 104 B are complementary. At the end of the clock period of the track-and-hold 102 A (f t/hA ), the output 510 B of the track-and-hold 102 A is sampled by the sub-ADC 104 B. At the end of the next period, the output 510 A of the track-and-hold 102 A is sampled by the sub-ADC 104 A.
In the next stage, the output of each sub-ADC is split up again. For example, the output of the sub-ADC 104 A ( 512 A, 512 B) is sampled by encoders 106 A, 106 B, respectively. The clock inputs f encA , f encB to the two encoders 106 A, 106 B are similarly one half of the clock input to the sub-ADC 104 A, and are complementary in phase. The outputs 514 A, 514 B of the two encoders 106 A, 106 B, respectively, are fed into a 2-to-4 demultiplexer 108 A, which retimes the two input digital signals with one of the clock phases f encA –f encP , e.g., f encI , as shown in FIG. 5 , and de-multiplexes them into four parallel outputs at half the input rate. (The RT in block 108 A stands for “retimer”).
The output data at the outputs of the encoders 106 A– 106 P has different phases, therefore, it needs to be retimed to the same phase, which the retimer and demultiplexer blocks 108 A– 108 H accomplish. The remainder of the circuit shown in FIG. 5 works based on the same principles as described above.
In the circuit of FIG. 5 , the encoders 106 and the demultiplexers 108 may be viewed as the back-end, and the track-and-holds 102 and the ADCs 104 may be viewed as the front-end.
Note that the demultiplexers in blocks 108 can be used recursively, for example, to convert 32 to 64 parallel outputs, etc. Note also that the parallel output signals of the first three stages of the circuit of FIG. 5 have different phases, while the outputs of the last stage, the demultiplexers, are all retimed to a single phase. All the signals are locked in phase relative to each other. In other words, there is no need to retime the data between each stage of the circuit. Note also that the output of any one of the encoders 106 can be “first”, or second, etc., given that the phases of their clock inputs f enc vary.
Thus, the circuit of FIG. 5 uses a multi-phase, multi-frequency clock. FIGS. 6A and 6B illustrate how such a clock can be generated, although the invention is not limited to this particular method of generating clock waveforms, and other mechanisms may be utilized. As shown in FIG. 6A , D flip-flops 602 A– 602 E can be added to the circuit, between the track-and-holds 102 A– 102 D and the sub-ADCs 104 A– 104 H, connected as shown. The track-and-holds 102 A– 102 D are driven by a single frequency four phase clock f t/ho –f t/h3 , which can be generated, for example, by a ring oscillator. At the sub-ADC stage, an eight phase clock running at half the rate is needed. The D flip-flops 602 A– 602 E, arranged as shown in FIG. 6A , provides such a clock. FIG. 6B shows the wave forms of the clocks f t/h and f adc .
Although not shown in figures, the clocks f enc for the encoder stage 106 can be derived in the same manner, using D flip-flops and driven by clock outputs f adc of the D flip-flops 602 A– 602 E shown in FIG. 6A .
The multi-phase signals are retimed into single phase as follows (see illustration in FIG. 6C , for the case of 3 track-and-holds and six sub-ADCs): step one: retime the outputs of half of the channels with their respective complement clocks, so that each complementary pair of outputs is aligned in phase. For example, sb 0 , sb 1 , sb 2 are retimed by fb 3 , fb 4 and fb 5 respectively, as is shown in FIG. 6C .
Step two: retime the outputs that have been aligned to the complementary phases with an original clock phase, preferably the middle one of the original phases, for equal setup and hold time margin. For example, the 6 data in three phases shown in FIG. 6C are retimed with fb 1 the middle phase among fb 0 , fb 1 and fb 2 . In other words, the diagram in FIG. 6C illustrates output data retiming. Note that only three distinct clock phases are necessary, with the other three (of the six) generated by inverting the clock waveform.
Thus, with this clocking approach, phase ambiguity is avoided, though the parallel data signals have different phases before the retiming (phase-alignment). The advantage is that there is no need to put an additional retiming block in each signal path of the first stage. This eliminates the overhead and signal degradation associated with such retiming circuitry in the front end of the signal path. Also, there is no need to use a reset to resolve the phase ambiguity.
Note also that although the architecture is easy to implement when it consists of a binary tree structure, the number of parallel operations in each hierarchy can be any increasing integer from the front-end to the backend. The number of hierarchies can be any integer. The multi-phase multi-rate clock generation can be used recursively to generate more than 2× clocks for an immediately lower hierarchy.
FIG. 7 illustrates the interleaving approach between the second stage and the third stage of the ADC hierarchy. The input in the circuit of FIG. 7 is from any one of the sub-ADCs, for example, sub-ADC 104 A. The signal is fed into a comparator regenerative latch 702 with reset. It is then fed into a non-reset digital latch 704 , and then split up into two signals 512 A, 512 B that are fed into D flip-flops 706 A, 706 B, which are clocked by complementary phase clocks f enc , f encc . The outputs of the D flip-flops 706 A, 706 B, are inputted into the encoders 106 A, 106 B, and then to D flip-flops 708 A, 708 B. The output of the second D flip-flop 708 B is also latched by a digital (half clock) delay latch 710 . The comparator regenerative latch 702 and the non-reset digital latch 704 may also be viewed as the last block of the sub-ADC 102 . Note that in the case of the latch 702 , the previous sample needs to be reset, so that the next sample can be latched. The non-reset latch 704 is analogous to a data latch, and does not need to be reset. The output of the latch 704 is sampled by the D flip-flops 706 A, 706 B. The outputs of the encoders 106 A, 106 B are sampled by the D flip-flops 708 A, 708 B. Note that at the outputs of the circuit in FIG. 7 are both clocked to the same clock f encc , In other words, after the operation of the latches, the data in all the paths is retimed (phase-aligned). It should be noted that the output of the retimed path corresponds to the input sample received earlier than the path that had not been retimed.
The presence of the latches in a circuit of FIG. 7 reduces problems with the meta-stability associated with the comparator regenerative latch 702 .
FIG. 8 illustrates an example of how the signal travels from the first stage of the hierarchy to the second stage of the hierarchy. As shown in FIG. 8 , the output of the track-and-hold 102 A is fed into a coarse programmable gain amplifier 402 , which then splits the signal into 510 A, 510 B and feeds it into two track-and-hold amplifiers 404 A, 404 B, which are clocked by the same clock (f adcA , f adcB ) as their corresponding sub-ADC (here, 104 A, 104 B). The outputs of the track-and-holds 404 A, 404 B are fed into fine programmable gain amplifiers 406 A, 406 B, respectively, and then to the sub-ADCs 104 A, 104 B. Note that the clock signals f adcA and f adcB are phase compliments of each other. The presence of the programmable gain amplifiers 402 , 406 allows reducing gain mismatch between the various signal paths.
In the present invention, because the overall area is reduced, and the number of devices (e.g., track-and-hold amplifiers, sub-ADCs, etc.) is reduced, the devices can be packed closer together, reducing mismatch. The mismatch can be a gain mismatch, an offset mismatch, or a timing mismatch. Of the three mismatches, the timing mismatch, or the sampling clock mismatch, is usually the most troublesome one. However, once the signal is sampled, the timing after that point becomes essentially irrelevant. Therefore, reducing the number of track-and-holds on the front-end reduces the timing mismatch problems. Additionally, the front-end circuitry, at current technology, can be clocked at multi-gigahertz speeds, which is at present virtually unachievable for the digital encoders and digital signal processors (DSPs) that the ADC outputs are usually fed to (but which only need to run at a fraction of the speeds of the front-end).
Although the particular embodiment described above is primarily in terms of an ADC, it will be appreciated that the invention is not limited to this application, but may be used in any application that requires parallel pipelined operation. For example, the invention may be used in telecommunication circuits (e.g., in SERDES, or serializer-deserializer, circuits, in digital processors, or any discrete-time analog, digital, or analog/digital circuits).
It should also be appreciated that various modifications, adaptations, and alternative embodiments thereof may be made within the scope and spirit of the present invention. The invention is further defined by the following claims.
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A hierarchical parallel pipelined circuit includes a first stage with a plurality of sampling circuits and a plurality of corresponding analog or digital circuits that receive an output from the plurality of sampling circuits. A second stage includes a second plurality of sampling circuits and a plurality of corresponding analog or digital circuits that receive an output from the plurality of sampling circuits. A multi-frequency, multi-phase clock clocks the first and second stages, the multi-frequency, multi-phase clock providing a first clock having a first frequency having either a single or plurality of phases, and a second clock having a second frequency having a plurality of phases. A first phase of a plurality of phases is phase locked to the first phase of the first clock. The clock frequency multiplied by the number of parallel devices in each stage is the throughput of the circuit and is kept constant across the stages.
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FIELD OF THE INVENTION
The present invention relates to a method for mechanical joining a metallic fitting, in particular an end coupling member, onto a tube of a composite material, especially for use in offshore oil exploration.
BACKGROUND OF THE INVENTION
In the offshore oil exploration field, the tubes and their end coupling members must resist tensile loads capable of reaching, in normal conditions of use, about a million Newtons.
The metallic tubes with metallic end coupling members used in oil exploration resist such loads.
Various industrial methods have been developed to produce composite tubes fitted with metallic end coupling members and capable of withstanding the significant tensile loads. The composite tubes have substantial advantages over metallic tubes because of their fatigue strength, corrosion resistance and lower weight.
According to a method described in French patent FR-A-2,509,011 by the applicants, a conical metallic insert is placed at the end of a composite tube. Between the outer surface of this end and the inner wall of the tube, an elastomeric layer is applied and adhesively bonded onto this outer surface, so that the loads are transmitted through the elastomeric layer. After a first polymerization of the tube, a second metallic member in the shape of a shell is applied on the polymerized composite, and is then hooped by a circumferential winding, for example of glass fibers. The metal/composite bond can also be provided through another elastomeric layer by a second curing to provide the polymerization of the outer hooping and the adhesive films.
A further method, described in EP-A-0,093,012, enables the joining of a tube made up of filament windings and of another body. Tubular and hollow metallic envelopes are interposed between fiber layers made up of filament windings, spaced in the radial direction, this being done at the ends. The connection is provided by securing devices which pass through the composite and the metallic envelopes. In this case, the tensile load applied to the metallic end coupling member is transmitted to the composite structure by a "hammering" effect.
According to yet another method described in French Patent FR-A-2,641,841 by the applicants, essentially longitudinal fibers are would continuously around a cylindrical mandrel in order to constitute the running part of the composite tube and, at the same time, around a metallic bi-conical shaped end coupling member. These longitudinal fibers are next bound to the metallic end coupling member by circumferential fibers before providing a final polymerization of the tube. Supplementary means are provided to enhance the integration of the end coupling member in the tube, and thus, limit the tube elongation.
These methods provide tubes which can be described as "rigid" by contrast with the "flexible" or "supple" metallic tubes, and which can withstand the tensile loads of the exploitation conditions of oil exploration at sea, while offering a minimal elongation under the internal pressure. However, such tubes all have the drawback that the length of the finished tube must be known before proceeding to the fabrication of the running part of the tube, that is to say the arrangement of filament windings.
In fact, in the three techniques referred to above, the winding of the filament layers constituting the tube is carried out on a mandrel bearing the connecting fittings, or end coupling members, of the tubes. These fittings are then wrapped by the fibers, and thus, "fixed" to the composite material.
Thus, it is not possible to produce and stock composite tubes until such time as the required length of the tube, equipped with connecting and coupling members, is known.
SUMMARY OF THE INVENTION
An object of the present invention is to provide a system for joining a metallic end coupling member, or, more generally a metallic fitting, to a composite tube previously wound and polymerized or hardened.
Another object of the present invention involves connecting a metallic fitting to a preformed composite tube by penetrating elements embedded into the two elements to be assembled so as to obtain a joining having a maximal tensile strength compared with the strength of the running part of the tube.
The present invention relates to a method for mechanical joining a tube made up of a composite material and a tubular metal fitting. In a first step, a tube of constant section is provided by winding filaments of pre-impregnated fibers which can be subjected subsequently to polymerization. The tube thus obtained can be cut into sections at right angles to its axis, to the desired length. Then, a tubular metal fitting is introduced at least partially into each end of the tube. The end of the tube and the penetrating part of the metal insert are secured by penetrating elements arranged according to at least uniform circumferential alignments, which are identical and identically spaced from one another. Each circumferential alignment defines a plane perpendicular to the axis of the tube and conforms to the following law of distribution: ##EQU1## D=the distance between two successive planes of circumferential alignments of penetrating elements,
K=an integer equal to 1 or 2,
n=the number of alignments,
i=the interval between two consecutive penetrating elements of the same alignment, and
α=the angle, with respect to the axis of the tube, of the layer of fibers providing the tensile strength.
Such method balances the resistance to "hammering" load of the composite material opposite the penetrating elements and the tensile strength of the remaining section of composite material on the first circumferential alignment of penetrating elements, which integrally withstands the whole tensile load. The following alignments (towards the end of the tube) withstand a progressively lower tensile load according to their rank.
Once this prior choice has been made, having regard to the distribution requirements set out above, the penetrating elements are distributed along helical lines, and more precisely, according to both right-hand pitch helical alignments and left-hand pitch helical alignments. All helical alignments are at the same angle equal to the positive or negative winding angle, corresponding to the backwards and forwards winding directions, respectively, of the fibers.
The above penetrating elements will be aligned according to generatrices of the tube or in staggered rows, according to whether the value adopted for the coefficient K is 1 or 2. One or other of these values is selected at will and takes into account the value of the winding angle. The effects of the two distribution modes are similar.
Each helical alignment of penetrating elements will affect the same bundle or bundles of fibers. Thus, the number of fibers sectioned for the implantation of the penetrating elements will be reduced.
The number of penetrating elements per circumferential alignment is determined, as indicated above, in order to obtain the balance between resistance to "hammering" load and tensile strength of the composite material on the first alignment. The total number of penetrating elements for each end of the tube is determined to obtain the desired resistance to "hammering" load. The elements are distributed according to an appropriate number n of adjacent circumferential alignments.
Calculations and tests have shown that three was an optimal value for the number n.
According to an embodiment of the method of the present invention, the metal fitting comprises an inner tubular part introduced into the tube, and an outer tubular element coaxial and integral with the inner part to sandwich the end of the tube. The penetrating elements can be pins extending through bores formed radially in the two metallic elements and the end of the tube.
Advantageously, the bores formed in the inner tubular metallic part are blind and do not open on the inner wall or surface of the metal fitting.
The method of the present invention does not necessitate any machining, either of the outside or of the inside, of the composite tube. This guarantees the integrity of the resistance of the tube. Machining includes all grinding of the diameter, internal or external, likely to cut into the fibers, and thus, diminish the resistance.
On the other hand, it may be necessary to perform a prior "bleaching" of the end of the tube, internal as well as external. The "bleaching" eliminates surface defects due to "rejects" of resin. Such "bleaching" is not likely to reach the fibers, that is to reduce the intrinsic resistance of the tube.
The method of the present invention can be applied to a tube having fibers wound along a constant angle.
It can apply also to a tube having two types of fibers wound along different angles.
In this case, the penetrating elements are distributed in conformity with the above law of distribution, taking into account only the winding angle of the fibers which are the most loaded in tension, that is, the fibers having the lowest winding angle with respect to the axis of the tube, without taking into account the fibers wound along the other winding angle. These latter fibers will be taken into account, to a certain extent, in distributing the penetrating elements in a particular manner.
This particular manner involves distributing the penetrating elements according, on the one hand, to two circumferential alignments complying with the law of distribution set out above and in which the angle β is the winding angle of the fibers which are the most loaded in tension and, on the other hand, to a third alignment interposed between the first two and delimited by the intersections between one or other of the helical alignments, with a left-hand or right-hand pitch. The penetrating elements of the above-mentioned two alignments and one or other of the helices, with a left-hand or right-hand pitch, are equal in angle to the winding angle of the second type of fibers and cross the penetrating elements of the first alignment.
Preferably, the following supplementary condition will be assigned to the distance D between two consecutive circumferential alignments:
D≧K'd
in which
K'=an integer or a mixed number ranging from 3 to 4,
d=the diameter of a penetrating element.
This supplementary requirement can equally be imposed in a general manner to any distribution of the penetrating elements according to the present invention.
Other objects, advantages and salient features of the present invention will become apparent from the following detailed description, which, taken in conjunction with the annexed drawings, discloses preferred embodiments of the present invention.
BRIEF DESCRIPTION OF THE DRAWINGS
Referring to the drawings which form a part of this disclosure:
FIG. 1 is a partial side elevational view in section of the end of a composite tube joined to a metal end coupling member in accordance with a first embodiment of the present invention;
FIG. 2 is a diagram of the distribution pattern according to generatrices of the tube of the pins of the device of FIG. 1;
FIG. 3 is a diagram of a distribution pattern of the pins, according to a second embodiment of the present invention, in staggered rows, for the same winding angle as that of FIG. 2;
FIG. 4 is an enlarged and more detailed view of FIG. 3;
FIG. 5 is a diagram illustrating a distribution pattern of the method of the present invention, according to a third embodiment of the present invention, for a low winding angle of the fibers;
FIG. 6 is a diagram illustrating a distribution pattern of pins according to a fourth embodiment of the present invention which takes into account a second type of fibers having a winding angle different from that of the first type of fibers;
FIG. 7 is a side elevational view of the end of a composite tube having two types of fibers with different winding angles, equipped with a metal end coupling member whose pins are distributed according to the diagram of FIG. 6; and
FIG. 8 is a cross-sectional view of the tube of FIG. 7, illustrating a distribution pattern for layers of the two type of fibers.
DETAILED DESCRIPTION OF THE INVENTION
FIG. 1 illustrates a tube 1 made up of composite material of constant thickness and formed by winding fibers, for example, carbon fibers. The fibers are wound along the same winding angle, marked α in absolute value, relative to the axis 2 of the tube. An equal proportion of fibers is wound in a +α direction, for example, winding to the left or in the forward direction, and in a -α direction, winding to the right or in the backward direction.
It will be assumed, at first, that the tube 1 comprises only the wound carbon fibers. The thickness of the tube is for example, about 20 mm.
The tube 1 is formed in a known manner, by winding pre-impregnated fibers on a mandrel, followed by a polymerization. After that, the tube is withdrawn from the mandrel and cut into sections to the desired length.
In the embodiment shown in FIG. 1, the end of the tube receives a metallic tubular fitting. The metal fitting has an end coupling member 3 comprising a part 3a in the form of a wedge, or inner insert, intended to be inserted inside the tube 1. The tube end abuts against a shoulder 4 of the end coupling member 3 and a separate metallic outer tubular part or insert 5, coaxial with the end coupling member. Outer tubular part 5 is added and secured on the outside of the end coupling member to grip the end of the tube in a sandwich manner with the inner part 3a. The outer part 5 comprises an inner peripheral heel 6 locked between the shoulder 4 and a nut 7 screwed onto a thread on the outer part 3b of the end coupling member.
A pin 8 extends radially through the outer insert 5 and penetrates partially into the shoulder 4. This allows a radial indexing of the tube 1.
The areas of insertion of the penetrating elements in the inner part 3a and outer part 5 have constant thicknesses. Beyond the insertion areas, that is, towards the central part of the tube, the thicknesses of parts 3a and 5 are reduced uniformly according to a slope intended to minimize the local bending of the composite material in the transition area between the running part of the tube and the metallic end coupling member.
The inner part 3a and the outer part 5 are provided with radial bores 9 and 10, respectively. The radial bores receive pins 11 extending radially through the wall of the tube 1. The pin ends are seated in opposing radial bores 9 and 10.
FIG. 2 illustrates the distribution pattern of the pins 11 all around the tube 1 and its end coupling member 3.
The pins 11 are distributed in three circumferential alignments 12, 13 and 14 (FIG. 2). Each circumferential alignment comprises the same fixed number of pins regularly distributed along an angle, the interval between two pins being i. Each alignment defines a plane perpendicular to the axis 2 of the tube. The distance D between two consecutive planes or alignments 12, 13, 14 is identical.
The pins 11 are, according to the present invention, distributed according to the law: ##EQU2## D=the distance between two successive planes of circumferential alignments (12, 13, 14),
K=is equal to 1, which corresponds to a distribution of the pins 11 according to generatrices of the tube 1,
n=the number of alignments, and is equal to 3,
i=the interval between two consecutive pins of the same circumferential alignment (12, 13, 14),
α=the winding angle, with respect to the axis 2 of the tube 1, of the fibers of the tube.
FIG. 3 illustrates a distribution pattern of the same total number of pins 11, also in three circumferential alignments 12, 13, 14, as the pattern illustrated in FIG. 2, and complies with the same law of distribution. However, the coefficient K has a value equal to 2, corresponding to a staggered row distribution of the pins 11.
The effects of the two patterns of distribution in FIGS. 2 and 3 are equivalent, as will be explained by reference to FIG. 4.
The spatial distribution of the pins 11, whether according to the pattern in FIG. 2 or according to the pattern in FIG. 3, is such that the pins 11 are in helical alignments 15 and 16 with a left-hand pitch of angle +α, (FIGS. 2 to 4), and in helical alignments 17 and 18 with a right-hand pitch of angle -α.
These helical alignments correspond to bundles of fibers in forward and backward directions. The same forward bundle, for example N (FIG. 4), will be crossed through from place to place by all the pins 11 of the alignment 16. The same backward bundle, for example N', will be crossed through from place to place by all the pins 11 of the alignment 18.
By bundle, the set of fibers superimposed over the entire thickness of the tube is contemplated.
In that way, a minimal number of fibers of the winding will be cut by the bores provided for the pins 11.
Thus, for example, the conjunction of the bundles of fibers N-1 and N'-1, which precede the bundles N and N' when viewing the winding from the left towards the right in FIG. 4, will take up the longitudinal loads F applied to the pin 11'. The bundle N-1 will withstand the load F'. The bundle N'-1 will withstand the load F". The resultant of F' and F" is equivalent to F in absolute value.
The delimitation of the bundles of fibers N,N',N-1,N'-1 is purely artificial and intended simply to facilitate the understanding of the effects of the particular implantation of the pins 11. The fibers are aligned and distributed in a homogeneous way through the entire thickness of the tube 1.
After calculations and tests, it was found that three was an optimal number of circumferential alignments.
Each circumferential alignment 12, 13 or 14 comprises the same number of pins 11. This number is preferably determined to obtain a balance between the resistance to "hammering" load of the composite material bearing on all the pins of the assembly and the tensile strength of the remaining section of composite material on the circumferential alignment in question.
The calculations are performed considering the resistance of the composite material. The composite material resistance is less than that of the material, for example, stainless steel, of the end coupling member (3,5).
Balancing between resistance to "hammering" load and tensile strength satisfies the following equation:
Rm·d·N·n=Rt (πD-d'N)
in which:
Rm=the resistance to "hammering" load of the composite material,
d=the diameter of the pins,
N=the number of pins per circumferential alignment,
n=the number of circumferential alignments,
Rt=the tensile strength of the composite material,
D=the average diameter of the composite tube, and ##EQU3##
Comparing FIGS. 2 and 3, in the distribution of the pins 11 according to generatrices (FIG. 2), the distance D between two consecutive circumferential alignments (12,13,14) is twice that of the distribution in taggered rows (FIG. 3). Thus, the choice of the value 1 or 2 for coefficient K may depend on the configuration of the metallic end coupling member 3 and on the value of the angle α. For the same number of circumferential alignments, a greater concentration of pins could be selected (FIG. 3), covering a shorter length on an end coupling member.
The case can occur, nevertheless, of a tube with a small winding angle α, as illustrated by FIG. 5. With such an angle, a more dense distribution in staggered rows of the pins on three circumferential alignments extends over a too wide surface of the end coupling member. Then, according to an alternative embodiment of the present invention, two circumferential alignments 12' and 13' will be defined, corresponding to the law of distribution according to the present invention, with K=2. Between the two alignments 12' and 13', preferably at mid-distance, a third alignment 14' is added, identical to the two others and constituted by pins 11 placed on the right-hand pitch helical alignments 17,18 as illustrated in FIG. 5, or on the left-hand pitch helical alignments 15,16. This distribution is a compromise, since the pins 11 of the alignment 14' will necessarily affect the forward (or backward) winding of the fibers.
Moreover, the distance D' between two consecutive circumferential alignments (12',13',14') can be set at a minimal value by constraining the implantation of pins by respecting, moreover, the following condition:
D'≧K'd
in which
K'=an integer or a mixed number ranging from 3 to 4, and
d=the diameter of a pin.
In the case of FIG. 5, for the available or desirable length for the implantation of pins on the metal end coupling member in three circumferential alignments, due to the value of the angle α, the distance D' may not fulfil the second condition set out above. In such case, two alignments 12' and 13' would be used or adopted. This second condition may clearly be applied to the distance D of the distribution patterns of FIGS. 2 to 4.
If the tube comprises two types of fibers, for example, carbon fibers intended to carry the longitudinal loads and glass fibers intended to carry the circumferential loads, the winding angle α of the carbon fibers will be taken into account for the distribution of the pins. The higher or lower number of glass fibers cut for the insertion of the pins will not fundamentally affect the behavior of the end coupling member with respect to the longitudinal loads.
The mounting of the inner part 3a and outer part 5, as well as the drilling of the bores 9 and 10, does not necessitate any machining of the end of the tube 1, either inside or outside. The generatrices of the tube remain rectilinear. Only a light non-destructive "bleaching" of the fibers may be necessary to remove resin thrown outs and enable the mounting, especially of the inner part 3a.
Moreover, the increases in external diameter and the decreases in internal diameter at the level of the parts 5 and 3a are minimized as much as possible with respect to the running part of the composite tube.
However, it can be advantageous to account for the second type of fiber and to find a compromise enabling, not only a limitation of the cutting of the fibers having the highest coefficient of tensile strength, under the same conditions as set out above, but also, to a certain extent, the best use of the fibers of the other type which also participate, although to a lower degree, in the strength of the tube with respect to the longitudinal loads. FIG. 6 illustrates a distribution of the pins in such case, according to another embodiment of the method of the present invention.
As in FIG. 5, two circumferential alignments 12',13' of pins 11 are defined. The alignments correspond to the law of distribution of the present invention, with the angle α of the first type of fibers and with K=2.
A third circumferential alignment (14'a or 14'b) is defined, interposed between the two others and constituted by pins implanted at the intersection of the right-hand pitch helix 17' passing through the pins 11 of the first alignment 12' and of angle β. Angle β is equal to the winding angle of the second type of fibers (or even of the left-hand pitch helix of the same angle) with one or other of the helical alignments, with a left-hand pitch 15 or a right hand pitch 17, of the pins 11. At one of the two intersections, a pin 11a or 11b will be implanted.
Whichever of the two pins 11a,11b satisfies, the supplementary condition set out above regarding the minimal distance between the third alignment 14'a or 14'b and one or other of the alignments 12' and 13' will possibly be chosen. In that way, the pins (11a or 11b) of the third alignment will be on bundles of fibers, of the first and of the second type, already cut by the pins 11 and the first two alignments 12' and 13'. However, the pins 11a or 11b will affect the backward (or forward) winding of the fibers of the second type.
In the case where the supplementary condition is not satisfied for either of the alignments 14'a, 14'b, for example where the angles α and β are close together, distribution will be according to FIG. 5.
If the left-hand pitch helices of angles +β 15' are chosen, the pins will be implanted as illustrated at 11'a and 11'b in FIG. 6, symmetrically with the pins 11a, 11b with respect to the axis 2 of the tube 1.
FIG. 7 represents a metal end coupling member 3 fixed to the end of a composite tube 1. An implantation of the pins 11 is according to the pattern of FIG. 6 (pins 11 and 11a or 11'b)
FIG. 8 shows an illustrative embodiment of the tube 1 with two types of windings. A winding mandrel 20 supports strata of glass fibers 21, each constituted by a certain number of layers of fibers, and three strata of carbon fibers 22, each also constituted by a certain number of layers of fibers. The winding angle of the glass fibers is, for example, on the order of 60°. The winding angle of the carbon fibers is on the order of 20°.
The two alignments 12' and 13' of pins 11 of FIG. 7 are determined by the law of distribution according to the present invention with α=20° and K=2. The intermediate alignment 14' is determined in accordance with the distribution pattern illustrated by FIG. 6, with helices 15' of angle +β=60°.
The method of the present invention applies in general manner to all joining of a composite tube stressed in tension, compression, inner pressure, and torsion, with a tubular metal fitting added to the ends, and particularly, but not exclusively, with end coupling members.
While various embodiments have been chosen to illustrate the invention, it will be understood by those skilled in the art that various changes and modifications can be made therein without departing from the scope of the invention as defined in the appended claims.
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A method of joining a tube of composite material and a tubular metal fitting includes, winding filaments of pre-impregnated fibers to produce a tube with a longitudinal axis. The fibers that provide tensile strength for the tube are at a tensile fiber angle relative to the longitudinal axis. A tubular metal fitting is introduced at least partially into an end of a tube section, with inner and outer parts of the fitting being located inside and outside of the tube section. The inner and outer parts are secured by inserting penetrating elements extending radially through the tube section and the parts of the fitting. The penetrating elements are arranged in uniform circumferential alignments which are equally spaced from each other along the longitudinal axis. Each circumferential alignment defines an alignment plane perpendicular to the longitudinal axis and spaced by a distance which is a function of an integer, the number of circumferential alignments, the interval between two consecutive penetrating elements in the same circumferential alignment and the tensile fiber angle.
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The present application claims benefit of U.S. Provisional Patent Application No. 60/083,391, filed Apr. 29, 1998, the disclosure of which is hereby incorporated by reference.
BACKGROUND OF THE INVENTION
Many orally-administered drugs display poor bioavailability when administered in conventional dosage forms, i.e., the rate and extent to which the drugs are absorbed is less than desirable. With several drugs, absorption may be as little as 30% or less of the orally administered dose. To compensate for this effect, a very large dose is often administered so that absorption of the therapeutically required quantity of the drug can occur. This technique may prove costly with expensive drugs; and the nonabsorbed drug may also have undesirable side effects within the gastrointestinal tract. In addition, poorly absorbed drugs often display large inter- and intrasubject variability in bioavailability. See Aungst, B. J., J. Pharm. Sci., 82:979-987, 1993. Specific examples (with the average bioavailability given in parentheses) include methyldopa (25%) with a range of 8% to 62%. See Kwan, K. C., Folz, E. L., Breault, G. O., Baer, J. E., Totaro, J. A., J. Pharmacol. Exp. Ther., 198:264-277, 1976; and nalbuphine (approximately 17%) with a range of 6% to 40%. See Lo. M.-W, Schary, W. L., Whitney, C. C., Jr., J. Clin. Pharmacol., 27:866-873, 1987. Such variation in the amount of drug absorbed does not allow for good control of the disease condition.
To improve the bioavailability of poorly absorbed drugs, penetration enhancers have also been employed. However, many of the penetration enhancers referred to in the current literature damage the absorbing tissues and thus are not a practical solution to the problem of poor bioavailability. In fact, it has been suggested that the damage to the mucosa caused by these agents may be the factor responsible for the improved absorption. See LeCluyse, E. L. and Sutton, S. C., Advanced Drug Delivery Reviews, 23:163-183, 1997.
Other techniques which have been employed to improve bioavailability include using enteric coated tablets having effervescence to rapidly dissolve or disperse the dosage form in the stomach. See U.S. Pat. Nos. 4,503,031; 4,289,751; and 3,961,041.
SUMMARY OF THE INVENTION
The pharmaceutical compositions of the present invention comprise orally administerable dosage forms that use effervescence as a penetration enhancer for drugs known, or suspected, of having poor bioavailability. Effervescence can occur in the stomach, once the tablet or other dosage form is ingested. In addition to effervescence in the stomach, or as alternative technique, by the use of appropriate coatings and other techniques, the effervescence can occur in other parts of the gastrointestinal tract, including, but not limited to, the esophagus, duodenum, intestinal and colon. The site of effervescence and drug release is chosen to correspond with the segment of the gastrointestinal tract displaying maximal absorption of the formulated drug, or to gain some other therapeutic advantage. Desirably, such site is not in the mouth of the subject.
BRIEF DESCRIPTION OF THE DRAWINGS
FIG. 1 . is an enlarged top plan view of a tablet which has a bioconcaved shaped.
FIG. 2 . is an enlarged side view of an enteric coated multilayered tablet.
FIG. 3 . is an enlarged top view of an enteric coated multilayered tablet, which depicts the effervescent external to the mucous adhesive layer.
FIG. 4 . is an enlarged top view of an enteric coated multilayered pellet, which depicts the effervescent external to the mucous adhesive layer.
DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS
The pharmaceutical compositions of the present invention comprise orally administerable medicaments in combination with an effervescent as a penetration enhancer for influencing absorption of a drug in the gastrointestinal tract. Effervescence leads to an increase in the rate and/or the extent of absorption of the drugs that are known or suspected of having poor bioavailability. It is believed that such increase can rise from one or all of the following mechanisms:
1. reducing the thickness and/or the viscosity of the mucus layer which is present adjacent to the gastrointestinal mucosa;
2. alteration of the tight junctions between cells, thus promoting absorption through the paracellular route;
3. inducing a change in the cell membrane structure, thus promoting transcellular absorption;
4. increasing the hydrophobic environment within the cellular membrane.
The present dosage forms include an amount of effervescent agent effective to aid in penetration of the drug in the gastrointestinal tract. The amount of effervescent employed must not merely permit rapid dispersion of the medicament in the gastrointestinal tract, but must aid in penetration of the drug across the gastrointestinal mucosa. The formulations of the present invention may be distinguished from other effervescent formulation that are enteric coated on the basis of the amount of effervescent material that they contain. Prior formulations contain approximately half to a quarter as much bicarbonate as drug on a weight basis (together with a proportionate amount of acid). In these cases, the small amount of effervescent couple serves only to rapidly disintegrate the tablet.
The dosage forms of the present invention should preferably contain at least twice as much sodium bicarbonate (or an equivalent amount of other base) as drug (on a weight basis) together with the proportionate amount of an appropriate acid for generating the effervescent reaction. More preferably the present dosage forms should contain at least three times as much sodium bicarbonate as drug (on a weight basis) together with the proportionate amount of an appropriate acid. These high concentrations of effervescent couple are needed to generate effervescence in sufficient amounts to promote permeability and absorption of the drug.
Preferably, the effervescent is provided in an amount of between about 5% and about 95% by weight, based on the weight of the finished tablet, and more preferably in an amount of between about 30 to about 60%. However, the amount of effervescent agent must be optimized for each specific drug.
The term “effervescent penetration enhancer” includes compounds which evolve gas. The preferred effervescent penetration enhancers evolve gas by means of a chemical reaction which takes place upon exposure of the effervescent penetration enhancer to water and other fluids. Such water-activated materials must be kept in a generally anhydrous state and with little or no absorbed moisture or in a stable hydrated form, since exposure to water will prematurely disintegrate the tablet. The acid sources may be any which are safe for human consumption and may generally include food acids, acid and hydrite antacids such as, for example, citric, tartaric, amalic, fumeric, adipic, and succinics. Carbonate sources include dry solid carbonate and bicarbonate salt such as, preferably, sodium bicarbonate, sodium carbonate, potassium bicarbonate and potassium carbonate, magnesium carbonate and the like.
The effervescent penetration enhancers of the present invention is not limited to those which are based upon a reaction which forms carbon dioxide. Reactants which evolve oxygen or other gases and which are safe for human consumption are also considered within the scope of the present invention.
The present dosage forms may also include in amounts additional to that required for effervescence a pH adjusting substance. For drugs that are weekly acidic or weakly basic, the pH of the aqueous environment can influence the relative concentrations of the ionized and the unionized forms of the drug present in solution, according to the Henderson-Hasselbach equation. Th pH of solutions in which an effervescent couple with equimolar amounts of base and acid has dissolved is slightly acidic due to the evolution of CO 2 . While it is impractical and may not be desirable to change the pH of the contents of the small intestine, it is, nevertheless, possible to alter the pH of the local environment (intestinal contents in immediate contact with the tablet and any drug that may have dissolved from it). This is achieved by incorporating in the tablet certain pH adjusting substances. Thus, the relative proportions of the ionized and unionized forms of the drug may be controlled.
In this way the system can be optimized for each specific drug under consideration: if the drug is known, or suspected, to be absorbed through the cell membrane (transcellular absorption), it would be most appropriate to alter the pH of the local environment to a level that favors the unionized form of the drug. Conversely, if the ionized form is more readily dissolved the local environment should favor ionization. Thus, for fentanyl, as a nonlimiting example, the pH is adjusted to neutral (or slightly higher) since the pKa is 7.3. At this pH, the aqueous solubility of this poorly water-soluble drug is not compromised unduly, yet allowing a sufficient concentration of the drug to be present in the unionized form. This facilitates the permeation enhancement brought about by effervescence. In the case of prochlorperazine (pKa=8.1), a slightly higher pH is required.
Suitable pH adjusting substance for use in the present invention include any weak acid or weak base (in amounts additional to that required for effervescence) or, preferably, any buffer system that is not harmful to the gastrointestinal mucosa. These include, but are not limited to, any of the acids or bases previously mentioned as the effervescent components, sodium carbonate, potassium carbonate, potassium carbonate, disodium hydrogen phosphate, sodium dihydrogen phosphate, and the equivalent potassium salts.
The active agents suitable for use in the present invention preferably includes any drug that displays poor bioavailability, slow absorption or long t max . These active ingredients include small molecule drugs, nutritional supplements (such as vitamins and minerals), proteins and peptides and other substances of biological origin. Examples of such drugs include, but are not limited to, the following:
Drug
Bioavailability (%)
Acyclovir
15-30
Auranofin
15-25
Bretylium
23 ± 9
Cyclosporine
23 ± 7
Cytarabine
20
Doxepin
27 ± 1O
Doxorubicin
5
Hydralazine
16-35
Ketamine
20 ± 7
Labetalol
18 ± 5
Mercaptopurine
12 ± 7
Methyldopa
25 ± 16
Nalbuphine
25 ± 16
Naloxone
2
Pentoxifylline
19 ± 13
Pyridostigmine
14 ± 3
Terbutaline
14 ± 2
Verapamil
22 ± 8
Riboflavin
11
Atenolol
50
Pharmaceutical ingredients suitable for use in the present dosage forms may include, without limitation, analgesics, anti-inflammatories, antipyretics, antibiotics, antimicrobials, laxatives, anorexics, antihistamines, antiasthmatics, antidiuretics, antiflatuents, antimigraine agents, antispasmodics, sedatives, antihyperactives, antihypertensives, tranquilizers, decongestants, beta blockers; peptides, proteins, oligonucleotides and other substances of biological origin, and combinations thereof. Also encompassed by the terms “active ingredient(s)”, “pharmaceutical ingredient(s)” and “active agents” are the drugs and pharmaceutically active ingredients described in Mantelle , U.S. Pat. No. 5,234,957, in columns 18 through 21. That text of Mantelle is hereby incorporated by reference. Alternatively or additionally, the active ingredient can include drugs and other pharmaceutical ingredients, vitamins, minerals and dietary supplements as the same are defined in U.S. Pat. No. 5,178,878, the disclosure of which is also incorporated by reference herein.
The dosage forms preferably contain materials that aid in releasing the drug in a specific section of the gastrointestinal tract, thus promoting site-specific delivery. There are various mechanisms by which such materials promote site-specific delivery and this invention is not limited to any one mechanism. For example, the material may be metabolized by enzymes present in a specific part of the gastrointestinal tract, thus releasing the drug in that section.
The materials used to promote site-specific absorption may preferably be included as coatings and/or as matrix materials. If a coating is used, it may be applied to the entire dosage form or to the individual particles of which it consists. Coating materials may be used to prevent the release of the active agent before the dosage form reaches the site of more efficient absorption.
The coating can also be used in conjunction with an effervescence to cause the effervescence to occur at specific areas of the gastrointestinal tract. Nonlimiting examples or coatings used in the present invention include: cellulose derivatives including cellulose acetate phthalate (CAP); shellac and certain materials sold under the trademark Eudragit™ (various grades may be used in specific combinations). Hydroxypropylmethyl cellulose phthallate in a grade that dissolves at pH 5 is the preferred coating material.
Precoating materials may also be used in the present invention. Nonlimiting examples include cellulose derivatives such as methylcellulose, hydroxypropyl cellulose, hydroxypropyl methylcellulose or combinations and certain materials sold under the trademark Eudragit™ (various grades which may be combined). Hydroxypropylmethyl cellulose phthallate in a grade that dissolves at pH 5 is the preferred coating material.
Other materials may be used to aid in site specific delivery, and include, for example, sugars, polysaccharides, starches, polymers, etc. These compounds may be included as coatings or as matrix materials and aid in releasing the drug in specific sections of the gastrointestinal tract, thus promoting site-specific delivery.
Other ingredients or techniques may preferably be used with the present dosage forms to enhance the absorption of the pharmaceutical ingredient, to improve the disintegration profile, and/or to improve the organoleptic properties of the material and the like. These include, but are not limited to, the use of additional chemical penetration enhancers, which are referred to herein as noneffervescent penetration enhancers; absorption of the drug onto fine particles to promote absorption by specialized cells within the gastrointestinal tract (such as the M cells of Peyer's patches); ion pairing or complexation; and the use of lipid and/or surfactant drug carriers. The selected enhancement technique is preferably related to the route of drug absorption, i.e., paracellular or transcellular.
A bioadhesive polymer may preferably be included in the drug delivery device to increase the contact time between the dosage form and the mucosa of the most efficiently absorbing section of the gastrointestinal tract. See Jonathan D. Eichman, “Mechanastic Studies on Effervescent-Induced Permeability Enhancement,” University of Wisconsin-Madison (1997), hereby incorporated by reference. Nonlimiting examples of known bioadhesives used in the present invention include: carbopol (various grades), sodium carboxy methylcellulose, methylcellulose, polycarbophil (Noveon AA-1), hydroxypropyl methylcellulose, hydroxypropyl cellulose, sodium alginate, and sodium hyaluronate.
Disintegration agents may also be employed to aid in dispersion of the drug in the gastrointestinal tract. Disintegration agents include any pharmaceutically acceptable effervescent agent. In addition to the effervescence-producing disintegration agents, a dosage form according to the present invention may include suitable noneffervescent disintegration agents. Nonlimiting examples of disintegration agents include: microcrystalline cellulose, croscarmelose sodium, crospovidone, starches and modified starches.
Apart from the effervescent material within the tablet, some additional effervescent components or, alternatively, only sodium bicarbonate (or other alkaline substance) may be present in the coating around the dosage form. The purpose of the latter effervescent/alkaline material is to react within the stomach contents and promote faster stomach emptying.
The drug delivery device may be in the form of a tablet, granules, pellets or other multiparticulates, capsules that can contain the drug in the form of minitablets, beads, or a powder, or any other suitable dosage form.
If tablets are used, they may be matrix tablets; layered tablets in which the various components are separated in different layers to optimize their benefits; or other specialized forms of tablets, including nonconventional shapes and geometric arrangements. One example of a nonconventional shape is a flat-faced tablet with a biconcave central zone, as depicted in FIG. 1 . The outer, thicker part of the tablet may contain the mucoadhesive material while the inner, thinner segment may contain the drug and effervescent components. This arrangement allows drug release to a segment of the gastrointestinal mucosa in close proximity to the point at which the tablet is attached to the mucosa.
The drug and/or the effervescent material could be present in a sustained release matrix. The whole tablet may consist of this matrix or the matrix may be confined to one, or more, layers of a multilayered tablet. FIG. 2 depicts a multilayered tablet with a central layer containing the drug and optional effervescent material; and two mucoadhesive layers. The tablet would adhere to the mucosa irrespective of its spatial orientation within the intestine.
FIGS. 3 and 4 depict the effervescent layer external to the mucoadhesive layer of each dosage form. FIG. 3 depicts a multilayered tablet in which a central core is completely surrounded by each subsequent layer. Such a tablet may be prepared by a compression coating technique. A similar physical arrangement of layers can also be achieved in a spheroid or pellet which may be prepared by extrusion and spheronization, layering, coating or any combination of these techniques. (See FIG. 4.) The effervescence will cause a thinning of the mucus layer from the gastrointestinal segment, thus facilitating adhesive of the dosage form to the cellular surface rather than to the mucus layer. This arrangement promotes better absorption of the drug.
Tablets can be manufactured by wet granulation, dry granulation, direct compression or any other tablet manufacturing technique. The tablet may be a layered tablet consisting of a layer of the active ingredients set forth above in layers of diverse compositions. In accordance with the present invention, the tablet size is preferably up to about ¾″. In accordance with the present invention, the multiparticulate size is preferably up to about 3 mm. In accordance with the present invention, the tablet hardness is preferably between about 5N and 100N.
Excipient fillers can be used in connection with the present invention to facilitate tableting. Nonlimiting examples of fillers include: mannitol, dextrose, lactose, sucrose, and calcium carbonate.
Pellets or other multiparticulates may be manufactured by granulation, layering techniques, extrusion and spheronization or other pellet manufacturing methods. The multiparticulates are then coated with an enteric coating material as described for tablets. The coating is preferably done in a fluid bed coater. The preferred, but nonlimiting, coating material is hydroxypropylmethyl cellulose in a grade that dissolves at pH 5. The multiparticulates are then packed into capsules.
The granules may be made by a wet granulation process or a dry granulation process. When wet granulation is used, isopropyl alcohol, ethyl alcohol or other nonaqueous granulating agent is used. Low moisture content grades of these organic solvents are used.
Dry granulation may be achieved through slugging or chilsonation. Layering may be done in a fluid bed apparatus or coating pan. Nonaqueous binders are used to aid the adherence of the added material (drug, effervescent penetration enhancer and excipients) to the starting material. Nonlimiting examples of the starting material or cores are nonpareils (sucrose) or microcrystalline cellulose seeds.
The preferred technique for the manufacture of multiparticulates is extrusion and spheronization. The beads contain the drug, effervescent couple (as previously described), a fine particle diluent which also aids in the formation of the beads (examples are lactose and mannitol) and a spheronization aid such as microcrystalline cellulose. The preferred grade of the latter is Avicel RC 591 which contains sodium carboxymethyl cellulose as an additional ingredient. For this formulation, a nonaqueous solvent is used. Nonlimiting examples of nonaqueous solvents are isopropanol and ethanol. Low moisture content grades are used.
The alternate (and preferred) formulation is to manufacture two populations of beads, one containing the acid component and the other the alkaline component of the effervescent couple. Each population of beads contains similar drug concentrations and can be manufactured using water. Care should be taken to ensure that each population of beads has a similar size range and a similar density. Equal densities may be achieved by the incorporation of a nontoxic material of high density to the population of beads that would, otherwise, have had a lower density. A nonlimiting example of such a material is barium sulfate. Equivalence of size and density facilitates the achievement of similar emptying rates of the beads from the stomach once the dosage forms are consumed by the subject. When the beads come into contact with the intestinal fluids, the coating dissolves and the close proximity of the beads to each other allows the effervescent reaction to occur in situ.
The coating applied to the dosage forms of the present invention must be performed with precision to avoid pinhole faults since water penetration through such faults leads to rapid and premature disintegration of the tablet. Such coating can be performed by one skilled in the art who, additionally, takes precautions to limit abrasion and chipping of the partially formed coat during the coating process. A fluid bed coater, pan coater or other coating apparatus may preferably be used.
The invention will be further described by reference to the following detailed examples. These examples are provided for the purposes of illustration only, and are not intended to be limiting unless otherwise specified.
EXAMPLE 1
RIBOFLAVIN
INGREDIENTS
mg/TABLET
Riboflavin, USP
5
Silicified Microcrystalline Cellulose
19.7
Sodium Bicarbonate
18.2
Citric Acid, Anhydrous
13
Crospovidone
3
Magnesium Stearate
0.9
Colloidal Silicon Dioxide
0.5
TOTAL
60
The tablets were compressed to a hardness of 50 N using {fraction (3/16)} inch concave punches. The tablets had a friability of less than 0.25%. Coating solution was prepared according to the following formula:
INGREDIENTS
WEIGHT (gm)
Hydroxypropylmethyl cellulose
418.5
phthallate
Triethylcitrate
31.5
Ethanol
2025.0
Acetone
2025.0
TOTAL
4500.0
Using a fluidized bed coater, the tablets were coated to a 15% weight gain. Care was taken to fluidize the bed sufficiently so that agglomeration of the tablets did not occur during coating but excessive movement was avoided to minimize chipping of the tablets or abrasion of the coating material.
EXAMPLE 2
ATENOLOL
INGREDIENTS
mg/PER TABLET
Atenolol
7.143
Sodium bicarbonate
15.000
Citric acid
10.714
Silicified microcrystalline
26.043
cellulose
Magnesium stearate
0.900
Silicon dioxide
0.200
TOTAL
60.000
The tablets were compressed using {fraction (3/16)} inch concave punches to a hardness of 40 N. The tablets were coated with hydroxypropylmethyl cellulose phthallate solution as described above to a weight gain of 15%. Seven tablets were packed into a size 0 elongated capsule to form the final dosage form.
EXAMPLE 3
ATENOLOL POPULATION 1
INGREDIENTS
mg PER CAPSULE
Atenolol
25
Sodium bicarbonate
150
Lactose
37
Avicel RC 591
38
Water
Qc
TOTAL
250
The dry powders were blended together. Water was slowly added with mixing until a wet mass that was plastic (but not tacky) was formed. The wet mass was passed through an extruder. The extruded material was spheronized for 3 minutes. The beads that were formed were air dried for one hour and then dried in an oven at 35° C. overnight. The beads were sieved to remove large particles and fines.
EXAMPLE 4
ATENOLOL POPULATION 2
INGREDIENTS
mg PER CAPSULE
Atenolol
25
Citric acid
107
Lactose
80
Avicel RC 591
38
Water
Qs
TOTAL
250
Population 2 was made in a similar fashion to population 1. Each population of beads was separately coated to a 20% weight gain in a fluidized bed coater using the previously described coating solution. Two hundred and fifty milligrams of each population of beads was filled into size 0 elongated capsules and this formed the final dosage form.
Various modifications of the invention described herein will become apparent to those skilled in the art. Such modifications are intended to fall within the scope of the appending claims.
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The pharmaceutical compositions of the present invention comprise orally administerable dosage forms that use effervescence as a penetration enhancer for drugs known, or suspected, of having poor bioavailability. Effervescence can occur in the stomach, once the tablet or other dosage form is ingested. In addition to effervescence in the stomach, or as alternative technique, by the use of appropriate coatings and other techniques, the effervescence can occur in other parts of the gastrointestinal tract, including, but not limited to, the esophagus, duodenum, and colon. The site of effervescence and drug release is chosen to correspond with the segment of the gastrointestinal tract displaying maximal absorption of the formulated drug, or to gain some other therapeutic advantage.
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[0001] This application claims the benefit of U.S. Provisional Patent Application No. 60/437,460, filed Jan. 2, 2003, entitled “Engineered Glasses For Metallic Glass-Coated Wire”.
BACKGROUND OF THE INVENTION
[0002] 1. Field of the Invention
[0003] This invention relates to metallic wire for electromagnetic applications such as electronic article surveillance (EAS); and more particularly to engineered glasses having in combination transverse geometric dimensions and mechanical properties that collectively impart superior mechanical integrity and magnetic properties to the glass-coated EAS wire.
[0004] 2. Description of the Prior Art
[0005] Fine glass-coated metallic wire has been produced in a single step process without the use of quenching substrates.
[0006] A two-staged process as described by Taylor (Phys. Rev. 23, (1924) 655) involves drawing the end of a heated glass tube that contains molten alloy into a 0.5 to 1 mm diameter glass-coated rod having a length of a foot or more. This glass-coated rod is subsequently mechanically drawn through a heated die having holes the size of the final glass-coated wire diameter desired. Cooling rates employed by the Taylor method are much too low for production of metallic wire having an amorphous atomic structure.
[0007] U.S. Pat. No. 5,240,066 to Gorynin et al. discloses a method of casting amorphous and nanocrystalline alloy glass-coated wires. One of the problems with glass-coated wire produced by the '066 patent process is the tendency of glass to crack during manufacture or afterwards. The cracking problem is particularly acute when the product is exposed to changing temperatures. Another problem with the product produced by the '066 patent is its limited magnetic properties, for example low signal amplitude in the presence of an applied magnetic field. The restricted magnetic properties make the '066 product a poor candidate for use in EAS applications.
[0008] In U.S. Pat. No. 6,270,591 to Chiriac et al. and U.S. Patent Application Publication U.S. 2001/0001397 A1 (the '1397 application), there is disclosed a process as well as a glass-coated wire. The wire core is composed of an amorphous or nanocrystalline metallic alloy. Nowhere in either of these two references is a glass chemistry specified for preferential use in practice. In fact, only in Example 1 of each of these citations is reference made to the use of Pyrex®, which does not signify a specific glass chemistry, but rather a range of glass chemistries. For example, Corning Inc. offers two grades (7740 and 7789) of Pyrex for sale, one being slightly less dense and having slightly lower softening point than the other. Therefore, simply describing the use of Pyrex in glass-coated wire drawing operations is vague. As with the '066 patent, the glass-coated wire produced by Chiriac et al. and '1397 application exhibit limited magnetic response in the presence of an applied magnetic field. Such restricted magnetic properties impose reduced gating distance, limiting tag detection in EAS applications, and can trigger false alarms or fail to alarm during use of the tag in retail anti-theft systems. They also limit performance of the glass-coated wire product in other electromagnetic applications such as inductors, sensors, and transducers.
SUMMARY OF THE INVENTION
[0009] The present invention provides a method and means for producing metallic glass-coated wire directly from the melt. Metallic glass-coated wire products produced in accordance with the invention exhibit improved magnetic response in the presence of an applied magnetic field. The high signal amplitude and increased gating distance of these products make them excellent candidates for use in EAS applications.
[0010] Generally stated, a metallic glass-coated wire is formed by drawing a hollow glass fiber from a container in which molten alloy is entrained and solidified. Interference stress extant between the glass coating and the alloy core of the wire is achieved by systematically controlling thickness and mechanical elastic properties of the glass. The interference stress is tailored by selection of glass thickness, chemistry and structure to optimize wire drawing process conditions, including drawing temperature and strain rate. In addition the interference stress is especially tailored to assure physical integrity of the glass-alloy composite wire product. Local property variations along the wire length are minimized. Discrete wire segments thereby produced are especially suited for use in EAS applications.
[0011] In practice, the method of this invention allows for options in the production of glass-coated metallic wire. Limitations previously governing the selection of magnetic amorphous alloy compositions are mitigated by suitable selection of glass chemistry, microstructure and coating thickness. For magnetic amorphous alloys, a strong stress-induced magnetic directionality (anisotropy) can by induced either along the wire length, or in a plane perpendicular to the wire axis, depending on the selection of amorphous alloy chemistry, glass chemistry, microstructure, and the radial dimensions of the alloy and the glass.
BRIEF DESCRIPTION OF THE DRAWINGS
[0012] The invention will be more fully understood and further advantages will become apparent when reference is made to the following detailed description and the accompanying drawings, wherein like reference numerals denote similar elements throughout the several views and in which:
[0013] FIG. 1 shows a transverse cross-sectional view of glass-coated wire with an amorphous alloy core having nominal chemistry Fe 75 B 15 Si 10 (light colored circle) surrounded by glass (dark annulus);
[0014] FIG. 2 schematically shows a transverse cross-section of a microwire fiber, including algebraic variables for metallic core and fiber outer diameters.
[0015] FIG. 3 schematically shows an axial cross-section of a microwire fiber, including the algebraic variable for its length; and
[0016] FIG. 4 schematically shows an axial cross-section of a microwire fiber while under the influence of axial interfacial stress between the glass and the metallic core.
DETAILED DESCRIPTION OF THE INVENTION
[0017] As used herein, the term “amorphous metallic alloy” means a metallic alloy that substantially lacks any long-range order and is characterized by x-ray diffraction intensity maxima that are qualitatively similar to those observed for liquids or oxide glasses. In contrast, “nanocrystalline alloy” pertains to those having constituent grain sizes on the order of nanometers.
[0018] The term “glass”, as used throughout the specification and claims, refers to an inorganic product of fusion that has cooled to the solid state without crystallizing, or to glassy materials formed by chemical means such as a sol-gel process, or by “soot” processes, both of which are used to form glass preforms that are used in fiber optic processing. The latter materials are not fused, but rather are consolidated at high temperatures, generally below the fusion temperatures of the constituents in question.
[0019] The term “drawing”, as used herein, refers to the extension of a material using a tensile force, said extension resulting in a permanent reduction of materials cross-sectional area.
[0020] The term “fiber”, as used herein, refers to a thin element, which may be continuous or non-continuous, of circular or non-circular cross-section, and which has a transverse dimension less than about 50 μm.
[0021] The term “microwire”, as used herein, means a fiber that is present as a single element or as multiple elements, and comprises at least one metallic material. The term “microstructure”, as used herein, refers to the atomic arrangements, of a glass or as alloy, on the scale of approximately 10 nm to 10 mm. Glasses and alloys of a single chemical composition can have a wide variety of properties depending on their microstructure. It is possible to control microstructure, and hence properties, by processing variations.
[0022] The terms “liquidus temperature” and “liquidus”, as used herein, refer to the temperature above which there are no stable crystalline phases in the material.
[0023] The term “thermal contraction coefficient”, as used herein, refers to the amount of length change of a material per unit length of that material, and per unit temperature, when the materials is cooled from a high temperature to a low temperature.
[0024] The terms “annealing temperature” and “annealing point”, as used herein, refer to the temperature at which the viscosity of a glass is 10 12 Pa-sec.
[0025] The term “strain point”, as used herein, refers to the temperature at which the viscosity of a glass is 10 13.5 Pa-sec.
[0026] The terms “working temperature” and “working point”, as used herein, refer to the temperature at which a glass has a viscosity of 10 3 Pa-sec.
[0027] The term “saturation magnetization”, as used herein, refers to the finite level of magnetization attained by a ferromagnetic materials when sufficiently high magnetic fields are applied.
[0028] The term “magnetostriction”, as used herein refers to the change in dimensions of a magnetic material when subjected to a magnetic field.
[0029] The term “anisotropy”, as used herein, refers to an energetically preferred direction along which magnetization lies in a magnetic material.
[0030] The term “permeability”, as used herein refers to the increase of magnetization that occurs when a magnetic material is subjected to an applied magnetic field.
[0031] The term “squareness”, as used herein, refers to the ratio of remanent magnetization to saturation magnetization.
[0032] Stresses can develop between two materials of differing thermal contraction coefficient, as they expand and contract due to temperature excursions. This can lead to dramatic improvements of mechanical integrity and magnetic properties of glass-coated metallic microwire. The magnetic property opportunities arise from the magnetostrictive properties of the amorphous alloy. Problems can arise if the teachings of the present invention are not followed. The physical origin of some problems is related to the large stresses generated in both the metallic core and in the glass coating during the process of fiber formation from a high temperature.
[0033] Under slow cooling conditions, stresses typically begin to arise when both the glass and the alloy are cooled through the strain point. However, cooling rates are extremely high in our fiber forming process. A person schooled in the art of glass science would recognize that the temperature at which stresses begin to form are likely much higher, due to the finite time required for the stresses to relax with the time proportional to the viscosity and shear modulus of the materials in question. For present purposes we will assume that the stresses form at the glass annealing temperature (T g ).
[0034] For simplicity we will also assume that the temperature at which stresses begin to arise are determined by the glass coating.
[0035] In FIG. 2 there is shown the cross section of a typical glass-coated amorphous metallic fiber. With this geometry, and assuming that the elastic modulus and Poisson's ratio are equal for the alloy and glass, the stress in the glass is given by
σ gl = E 1 - μ ( T g - T ) ( α gl - α a ) A a A f ( 1 )
[0036] wherein the constituent terms are defined as:
E Elastic modulus. μ Poisson's ratio. T Temperature. T g Glass annealing temperature. T f Temperature to which the sample is cooled. α gl Average linear thermal contraction coefficient of the glass between T g and T. α a Average linear thermal contraction coefficient of the alloy between T g and T. A gl Cross-sectional area of the glass cladding. A f Total cross-sectional area of the fiber.
[0037] The axial stress in the metallic core is given by
σ a = E 1 - μ ( T g - T ) ( α a - α gl ) A gl A f ( 2 )
[0038] The cross-sectional areas are
A a = π D a 2 4 and A gl = π ( D f 2 - D a 2 ) 4 and A f = π D f 2 4 ( 3 )
where A a is the cross-sectional area of the metallic core.
[0040] Table I shows the calculations for various D i values where α gl is less than α a . The ratio of D f /D a is important since, for given E, μ and α values, the thickness of the glass coating relative to the metal core determines the stress in both, through the ratios A a /A f and A gl /A f . Values of the thermal contraction coefficient of the metallic alloys are not known precisely; but are assumed to be substantially equivalent to published thermal expansion coefficients.
TABLE I σ glass σ alloy D fiber D alloy Mpa Mpa PROPERTY μm μm (Compression) (Tension) E = 80 GPa 20 10 155 233 μ = 0.25 20 12 186 198 20 15 233 136 α glass = 3 ppm° C −1 . 30 10 103 276 α alloy = 8 ppm° C −1 . 30 20 207 172 30 25 258 95 T g = 600° C. 15 10 207 172 T = 20° C. 15 11 227 143 15 12 248 112
[0041] The alloy core is in tension along the axis of the fiber while the glass is in compression. Having the glass under compression is generally desired due to “delayed failure” phenomena in which cracks grow slowly under tension, leading to eventual failure. The relative thickness of the metallic core and overall fiber controls the magnitude of the stress in each. A small diameter metallic core will produce low stresses in the glass, but will itself having high tensile stresses.
[0042] When the thermal contraction coefficients are equal there will be little stress in either the glass or the alloy due to the cooling from the set point. However, as pointed out by U.S. Pat. No. 6,270,591 to Chiriac et al., the alloy will have an additional stress, due to the winding tension of the drawing process. The glass behavior can also be altered by the drawing process such that the effective thermal contraction coefficient is larger than that determined from the thermal contraction behavior of a normal, rapidly cooled glass rod.
[0043] When the contraction of the glass is greater than that of the alloy, the stress conditions are reversed. The metallic core will be under axial compression and the glass coating will be under axial tension. As noted, this is generally undesirable since failure of the glass coating can result.
[0044] When the contraction coefficient of the alloy is less than that of the glass, the degree of mismatch of the thermal contraction coefficients must be such that the stress in the glass coating is less than about 50 MPa and preferably less than about 20 MPa. Above this value it is possible to have slow crack growth over time, which can eventually cause failure of the glass coating and release of stress, locally in the alloy, such that any beneficial magnetostrictive effect is lost. This is because an enhancement of magnetic properties via magnetostriction is desired. Furthermore, the glass coating will be much more susceptible to surface damage. It will be easier to introduce new flaws, with the same result, of a loss in stress in the interior alloy, and access of the environment to the metallic core through the cracks.
[0045] Equation (1) can be rearranged to permit calculation of the allowed thermal contraction mismatch for any give set of conditions.
( α gl - α a ) = ( 50 MPa ) ( 1 - μ ) E ( T g - T ) A f A a ( 4 )
[0046] Thus, large overall fiber diameters allow a greater mismatch, as does a small metallic core diameter, for a given fiber diameter.
[0047] For the above equations it has been assumed that the modulus and the T g of the glass and alloy are the same. If the moduli are substantially different, the equations are modified.
[0000] Case With Major Differences Between the Glass and Alloy Moduli.
[0048] Generally, the moduli of the alloy and glass are substantially different. In such cases, a more detailed composite approach is used to calculate the stresses. A side view of the composite is shown in FIG. 3 . The axial cross-section of microwire fiber shown by FIG. 3 is in the initial state, prior to cooling of the fiber.
[0049] In FIG. 4 there is shown an axial cross-section of a microwire fiber while under the influence of axial interfacial stress between its glass and the metallic core components. This condition of the microwire fiber occurs after cooling—assuming that the alloy and glass are not connected. In the microwire fiber shown by FIG. 4 , the alloy has a higher contraction coefficient than the glass.
[0050] The glass and alloy of the microwire shown by FIG. 4 are bonded. During drawing, the alloy will be pulled out to a length L c , indicated by the dotted vertical line, and the glass will be pulled into compression to L c . It is important that the sum of the absolute values of the change in length of the glass coating and that of the metallic core substantially equal the distance between the glass and alloy shown in FIG. 4 . Since that distance is related to the thermal contraction coefficients, and to the difference in temperature between the set-points and room temperature:
Abs (Δ L gl +ΔL a )= Abs ( L o ΔαΔT ) (5)
[0051] Where Δα is the difference in thermal contraction coefficients of the alloy and glass from the temperature at which stresses begin to form, to room temperature.
[0052] Also, if stresses are assumed to be uniform throughout the fiber:
σ a A a =−σ gl A gl (6)
[0053] And further:
σ a = ɛ a E a 1 - μ and σ gl = ɛ gl E gl 1 - μ ( 7 )
[0054] With these approximate conditions it is possible to show that:
ɛ a = ɛ gl E gl A gl E a A a = K ɛ gl
where ( 8 ) ɛ a = L c - L m L m and ɛ gl = L c - L gl L gl ( 9 )
[0055] The preceding equations allow calculation of an approximate stress in the metallic core and in the glass, due to the thermal contraction mismatch. Other factors, such as fiberizing temperature, cooling rate, and draw speed tend to influence the axial stress; but the above formulas describe effects of the important material properties and fiber geometry, over which the experimenter or producer has considerable control. Furthermore, the thermal contraction coefficients and the temperature at which stresses begin to form (assumed here to be T g ) will also vary with fiberizing temperature, cooling rate, and draw speed.
[0056] The values set forth in Table II illustrate the effects of the important material properties and fiber geometry. In each case, there is extant a temperature difference (ΔT) of 600° C. between the annealing point and room temperature. Poisson's ratio is 0.25 for each of the metal and the glass.
TABLE II E a E gl α a α gl D a d fib σ a σ gl GPa GPa ppm ° C −1 . ppm ° C −1 . μm μm MPa MPa 200 80 8.0 3.0 5 15 −610 76 200 80 8.0 3.0 5 20 −686 46 200 80 8.0 4.0 5 20 −549 37 200 80 10.0 3.0 5 20 −960 64 200 70 8.0 3.0 10 20 −410 137 150 100 8.0 3.0 10 15 −273 218 200 70 8.0 9.0 10 15 49 −39 200 70 8.0 10.0 10 15 97 −78 200 80 8.0 10.0 10 15 107 −85 200 80 8.0 10.0 6 15 217 −41 200 80 8.0 10.0 10 22 194 −50
[0057] As shown by the data in Table II, each of the parameters has an effect on the resultant stress in the alloy and glass. For a given set of material properties, considerable control over stress is exercised by altering the fiber geometry, specifically the ratio of the metallic core diameter to the overall fiber diameter. Increasing the metallic core diameter decreases the stress in the alloy while increasing stress in the glass.
[0058] Of critical importance is the ability to control tensile stress in the glass coating by increasing the overall fiber diameter while holding the metal core diameter constant. This is illustrated by the data set forth at rows 9-11 of Table II. Glass-coated amorphous microwire of the present invention can readily be tailored to be advantageously suited to a number of distinct applications by adjusting alloy and glass chemistry as well as the relative dimensions of the alloy and glass components. Among other benefits, our glass-coated amorphous microwire needs no magnetic field annealing to achieve optimal magnetic properties. This benefit is not readily obtained with conventional amorphous alloy ribbon which, when annealed to enhance magnetic properties such as permeability, squareness and saturation magnetization, encounters substantial degradation of mechanical properties, such as ductility. Exemplary properties of our glass-coated amorphous microwire include remarkably high magnetic permeability and squareness as well as high saturation magnetization. In addition, magnetostriction can readily be adjusted by appropriate selection of amorphous alloy chemistry. In combination, these properties make our glass-coated amorphous wires ideally suited for use in magnetic harmonics-based EAS systems for antipilferage, anti-counterfeiting, authentication and the like. In addition, the encoding of our glass-coated amorphous wire forges a critical link to establishing low-cost systems wherein multi-bit information storage media is read remotely. Applications for these systems comprise inventory control, drivers' licenses, passports, and various other documentation of import, including currency, commercial instruments and the like. The ability to readily obtain selected amorphous alloy magnetostriction values makes our amorphous glass-coated wire desirable for use in sensor and transducer applications. For example, the use of amorphous glass-coated wire in selected bandaging allows the remote detection and quantification of wound healing.
[0059] Applications for use of our glass-coated microwire further include its incorporation into or onto textiles, yarn, ribbon, thread and virtually any fabric for purposes of tracking garments and clothing associated therewith. Also included in potential applications are such paper products as cardboard, paper laminations, paper composites and packaging supplies assembled and manufactured with paper based materials. Further applications of our microwire include use in or on composites comprised of plastics and resin based materials. Applications within living subjects, including humans and animals, for tracking as well as for biomedical purposes, such as monitoring stent condition during residence in the body, are readily accomplished. Use of our microwire is also found in electronics for micro miniature connectors, magnetic inductors, coaxial cabling, and for carrying electrical power. Finally, microwire of the present invention is especially suited for use in pulse power applications, high frequency motors, RFI and EMI shielding, magnetic resonance imaging, thermostats, pressure gauges, stress loading devices and the like.
[0060] The following examples are presented to provide a more complete understanding of the invention. The specific techniques, conditions, materials, proportions and reported data set forth to illustrate the principles and practice of the invention are exemplary and should not be construed as limiting the scope of the invention.
EXAMPLE 1
[0061] An ingot composed of an amorphous-forming alloy is prepared by loading the appropriate weights of constituent elements into a quartz tube that is sealed at one end. The other end of this quartz tube is connected to a pressure-vacuum system to allow evacuation and back-filling with Ar gas several times to ensure a low oxygen Ar atmosphere within the quartz tube. Next, the closed end of the quartz tube in which the elements reside is introduced into a high frequency induction heating coil. With the application of radio frequency (“r.f.”) power, the elements inside the tube are caused to heat and melt into a stirred, homogeneous alloy body. When the r.f. power is shut off, the alloy body is allowed to cool to room temperature in the Ar atmosphere. Once cooled, the same alloy body is inserted into the bottom of a vertically disposed glass tube, having 6 mm diameter, that is sealed at the lower end. The upper end of this glass tube is connected to a pressure-vacuum system to allow evacuation and back-filling with Ar gas several times to ensure a low oxygen Ar atmosphere within the quartz tube. A specially-built inductor at the bottom of the glass tube is energized with r.f. power in order to heat and then melt the alloy body within the tube. Once the alloy body is molten and overheated by some 20 to 50° C., a solid glass rod is used to touch and bond to the bottom of the sealed glass tube in which the molten alloy resides. The heat of the molten alloy having softened the glass tube, allows is to be drawn by pulling on the glass rod to which it is attached. Molten alloy is entrained in the drawn glass capillary that results. The drawn capillary is then pulled and guided onto a spinning take-up spool, which provides both winding tension to ensure continuous drawing at a rate of about 5 meters/second and a systematic alloy wound package.
[0062] Amorphous glass-coated wire is produced using the procedure described above. The microwire has an Fe 77.5 B 15 Si 7.5 amorphous alloy core that is under axial tensile stress. Glass coating the microwire is a low-expansion borosilicate having an approximate composition set forth below:
Constituent Weight % SiO 2 80 B 2 O 3 13 Al 2 O 3 3 Na 2 O 4 Working Point 1,256° C. Assumed set point = Annealing Point = 565° C. (depends on cooling rate) Elastic Modulus 80 GPa α gl (Annealing pt. - 25° C.) 3.5 ppm ° C −1 .
[0063] The metallic alloy used to form the microwire has the following properties:
Liquidus 1,230° C. Elastic Modulus 200 GPa α a 8.0 ppm ° C −1 .
[0064] The working point of the glass is slightly higher than the liquidus temperature of the alloy, but within limits that allow easy fiber formation.
TABLE III Stresses in the metallic core and glass coating as a function of the fiber geometry. E a E gl α a α gl d a d fib σ a σ gl GPa GPa ppm ° C −1 . ppm ° C −1 . μm μm MPa MPa 1 200 80 8.0 3.5 5.0 15.0 −549 69 2 200 80 8.0 3.5 5.0 20.0 −617 41 3 200 80 8.0 3.5 5.0 25.0 −652 27
EXAMPLE 2
[0065] Amorphous glass-coated wire is prepared by the procedure described in Example 1. The microwire has an Fe 77.5 B 15 Si 7.5 amorphous alloy core that is under tensile stress. It has a glass coating consisting essentially of a medium expansion alkali borosilicate having an approximate composition:
Constituent Weight % SiO 2 72 B 2 O 3 12 Al 2 O 3 7 Na 2 O 6 K 2 0 2 CaO 1 Working Point 1140° C. Annealing Pt. 570° C. Elastic Modulus 80 GPa α gl (Annealing pt. - 25° C.) 7.0 ppm ° C −1 .
[0066] The working point of this glass is at the low end of allowed temperatures since the liquidus temperature of the alloy is 1,230° C.
TABLE IV Stresses in the metallic core and glass coating as a function of the fiber geometry. α a α gl E a E gl ppm ppm d a d fib σ a σ gl GPa GPa ° C −1 . ° C −1 . μm μm MPa MPa 4 200 80 8.0 7.0 5.0 25.0 −145 6 5 200 80 8.0 7.0 5.0 20.0 −137 9 6 200 80 8.0 7.0 10.0 15.0 −53 43
[0067] In this example the metallic core stress is small and can approach zero as the fiber diameter decreases while holding the metal diameter constant, or simultaneously.
EXAMPLE 3
[0068] Amorphous glass-coated wire is prepared using the procedure described in Example 1. The microwire has a Co 66 Fe 4 Ni 1 B 14 Si 15 amorphous alloy core that is under low stress, since this alloy has nearly zero magnetostriction. Components of the glass-coated wire are described below:
[0000] Glass
[0069] Soda-lime silicate container glass—approximate composition:
Constituent Weight % SiO 2 72 B 2 O 3 — Al 2 O 3 1 Na 2 O 14 K 2 0 — CaO 10 MgO 3 Working Pt. 1,035° C. Annealing Pt. 560° C. Elastic Modulus 70 GPa α(Annealing pt. - 25° C. ) 10.3 ppm ° C −1 .
[0070] Alloy
Liquidus 1,080° C. E 100 GPa α a 12.7 ppm ° C −1 .
[0071] Soda-lime silicate glass works well for this alloy as it has a lower working range, consistent with the low liquidus temperature of CO 66 Fe 4 Ni 1 B 14 Si 15 . Furthermore, the thermal contraction coefficient more closely matches that of the alloy.
TABLE V Stresses in the metallic core and glass coating as a function of the fiber geometry. α a α gl E a E gl ppm ppm d a d fib σ a σ gl GPa GPa ° C −1 . ° C −1 . μm μm MPa MPa 7 100 70 12.7 10.3 15.0 20.0 −68 87 8 100 70 12.7 10.3 10.0 20.0 −130 43 9 100 70 12.7 10.3 10.0 15.0 −90 72
EXAMPLE 4
[0072] Amorphous glass-coated wire is prepared using the procedure described in Example 1. The microwire has an Fe 81 B 13.5 Si 3.5 C 2 amorphous alloy core. Axial compressive stresses resulting in this example cause the microwire not to function magnetically. Its glass and metallic alloy components described below:
[0000] Glass
[0073] Medium expansion alkali borosilicate—same glass as in Example 2.
Working Point 1140° C. Annealing Pt. 570° C. Elastic modulus 80 GPa α gl (Annealing pt. - 25° C.) 7.0 ppm ° C −1 .
[0074] Alloy
Liquidus 1,171° C. α a 5.6 ppm ° C. -1 Elastic modulus 100 GPa
[0075] The quoted thermal contraction coefficient between room temperature and 300° C. is 5.5 ppm ° C. −1 . This would produce a compressive stress in the alloy core. However, using the thermal contraction coefficient between the annealing point and room temperature results in a tensile stress. The glass is also in tension under these conditions.
TABLE VI Stresses in the metallic core and glass coating as a function of the fiber geometry. α a α gl E a E gl ppm ppm d a d fib σ a σ gl GPa GPa ° C −1 . ° C −1 . μm μm MPa MPa 10 100 80 5.60 7.00 10.0 15.0 56 −45 11 100 80 5.60 7.00 5.0 15.0 97 −12 12 100 80 5.60 7.00 10.0 20.0 79 −26
EXAMPLE 5
[0076] Amorphous glass-coated wire is prepared using the procedure described in Example 1. The microwire has an Fe 77.5 B 15 Si 7.5 amorphous alloy core that is under increased axial tensile stress by use of a non-commercial, low contraction glass coating. Component parts of the glass-coated wire are described below:
[0000] Glass
[0077] Partially leached low expansion alkali borosilicate glass of Example 1. The glass is treated to reduce the amount of alkali and boron oxide, using techniques well known to a person schooled in the art of glass science, yielding a preform with lower thermal contraction coefficient and higher annealing temperature.
Working Point (Estimate) 1,300° C. Annealing Point 600° C. Elastic Modulus 80 GPa α gl (Annealing pt. - 25° C.) 2.5 ppm ° C −1 .
[0078] Alloy
Liquidus 1,230° C. Elastic Modulus 200 GPa α a 8.0 ppm ° C −1 .
[0079] TABLE VII Stresses in the metallic core and glass coating as a function of the fiber geometry. GPa GPa ppm ° C −1 . ppm ° C −1 . μm μm MPa MPa 13 200 80 8.0 2.5 5.0 15 −670 84 14 200 80 8.0 2.5 5.0 20 −754 50 15 200 80 8.0 2.5 5.0 30 −821 23
In this example the stresses in the metallic core are increased over those generated by either a Pyrex® or unmodified KG-33 glass. This results in improved magnetic properties of the magnetostrictive alloy core.
[0080] Having thus described the invention in rather full detail, it will be understood that such detail need not be strictly adhered to, but that additional changes and modifications may suggest themselves to one skilled in the art, all falling within the scope of the invention as defined by the subjoined claims.
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A metallic glass-coated wire is formed by drawing a hollow glass fiber from a container in which molten alloy is entrained and solidified. Interference stresses extant between the glass coating and the alloy core of the wire are produced by systematically controlling thickness and mechanical elastic properties of the glass. The interference stress is tailored by selection of glass thickness and chemistry to optimize wire drawing process conditions, such as drawing temperature and strain rate. In addition, the interference stress is especially tailored to assure physical integrity of the glass-alloy composite wire product. Local property variations along the wire length are minimized, facilitating production of discrete wire segments especially suited for use in EAS applications.
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BACKGROUND AND SUMMARY OF THE INVENTION
[0001] The present invention relates generally to entry systems for vehicles and, more particularly, to recreational vehicles having retractable entry steps.
[0002] Vehicular entry systems typically include one or more steps leading up to a door if the vehicle has an interior floor significantly higher than the surface upon which the vehicle rests. In many applications, these steps extend laterally outward from the vehicle a significant distance in order to be most conveniently used by a person entering the vehicle. However, when the vehicle is in motion, such steps are preferably retracted toward the vehicle in order to minimize the road space or width needed by the vehicle, streamline vehicular motion, and avoid collision of the steps with objects near the path of the vehicle.
[0003] Retractable steps for vehicles are typically of two types, manually actuated or power actuated. Various different manual actuation systems have been used, including scissor linkages, parallelogram linkages, rotatable folding connections, and/or slide connections, to allow the steps to be shifted between opened and closed positions. In general, the user folds and unfolds these step systems when standing outside of the vehicle by grasping a portion of the step system, usually one or more of the steps themselves, and then pushing, pulling, or lifting the system as needed.
[0004] Power actuation is particularly advantageous when it is desirable to actuate the steps from inside the vehicle. Power actuation is also advantageous when the steps are subjected to ice, snow, mud and debris, such that users prefer to avoid contact with the steps other than with footwear. Further, power actuation also provides greater personal security when one or more persons are to be within the vehicle for an extended period of time because retraction of the step once the vehicle is occupied limits access to the vehicle interior by others. In addition, power actuation allows the steps to be easily positioned by a single person regardless of the weight or size of the steps. However, power actuation mechanisms tend to take up significantly more space than manual actuation systems even for the same size and number of steps because of the extra space required for the motors and/or other actuators which drive the steps.
[0005] In general, the space required by retractable entry systems of either type is first determined by the number of steps needed to reach from the door to within a comfortable distance from the ground (or to the ground itself, if that is desired). Then, the nature of the supporting structure for those steps must be taken into account, and then the “folding” or retracting structure (power actuated or not). Finally, consideration must be given for how the entry system is to be mounted to the vehicle.
[0006] For greatest strength and security, it can be advantageous to mount the retractable entry system directly or indirectly to the primary frame or chassis of the vehicle (often of I-beam or rectangular tube construction), rather than merely to the outer side wall of the vehicle. Thus, an opening is often left in the side wall to allow the retractable entry system to be bolted, for example, to the underlaying I-beam, typically 14 inches or so inwardly of the side wall. However, having only a 14 inch wide space for retracted stowage can significantly limit the vertical reach or capacity of a retractable entry system.
[0007] It is usually undesirable to allow any portion of the retractable entry system to protrude significantly beyond the outer side wall when the vehicle is moving. Thus, when retracted, the entire entry system must fit within that 14 inch width. However, using conventional actuation systems, the maximum number of steps which can be folded into a 14 inch wide space may be only three, especially if the actuation system is powered. Thus, if a standard eight to ten inch drop is permitted between each step, the maximum height which is comfortably serviceable by such prior systems is with vehicles having an entry door no more than 32 to 40 inches above the ground (and even less so if the bottom step is desired to be close to or resting just at ground level, so as to relieve any cantilever effect on the entry system as a whole).
[0008] When fully extended, some entry systems can be subject to a cantilever effect which gives a noticeable and potentially unsafe “bounce” when someone uses the bottom step(s). To overcome that effect, some prior entry systems have been constructed to “beef-up” the structure to increase rigidity, but that can make the cost and/or retracted dimensions of the entry system significantly higher. Resting on the ground is one cost effective way for an entry system to eliminate the cantilever effect, but at a cost of losing one step's worth of vertical capacity.
[0009] Unfortunately for many prior retractable entry systems, a current trend in vehicles, particularly fifth wheel travel trailers and similar recreational vehicles, is to make the interior floor of the vehicle higher so that additional storage space is available below the interior floor. This tends to cause the vehicle entry door to be raised such that a three step retractable entry system is not feasible or desirable, especially if it is power actuated. This is particularly true where entry doors are used in the upper deck portion of the fifth wheel travel trailer, since the interior floor of the upper deck is higher still.
[0010] In response to these new vehicle designs, prior retractable entry door systems would need to have a special cut-out in the I-beam frame in order to add another step or two, or be mounted below the I-Beam, thereby reducing the ground clearance of the vehicle. Alternatively, a portion of the interior floor could be lowered to make up the extra step or two, at a sacrifice to usable floor space and floor planing optimization of the vehicle interior. Other solutions could involve using a vehicle chassis with a greater span between the I-beam and the outer side wall (thereby increasing the width of space available to mount and retain the retractable entry system), perhaps relying upon additional “outriggers” for vehicle support laterally of the I-beam toward the outer side wall. However, such chassis constructions can have significant disadvantages in terms of cost, weight, and structural capacity.
[0011] Another important factor which limits the usefulness of some prior retractable entry systems for the new, higher entry door vehicle designs, is that fuel economy and towability concerns impose substantial constraints on the permissible component weights. Ideally, the increased vertical capacity of the retractable entry systems must be achieved without significant increases in the system weight. At the same time, system reliability in a rugged environment is another critical concern, particularly for recreational vehicles. Fifth wheel travel trailers are, for example, hauled up and down over a wide variety of roads and trails, paved and unpaved, subject to significant usage stresses over time. Retractable entry systems would hardly be of value if their design could not stand up to those stresses for long periods of time.
[0012] Accordingly, it is an object of the present invention to provide an improved retractable entry system, especially one that is suitable for use with vehicles. In particular, objects of the present invention include the provision of retractable entry systems which:
a. require a minimum of retracted space while significantly improving the system's vertical capacity, b. avoid expensive manufacturing and maintenance costs, c. facilitate mounting to the vehicle and avoid special chassis requirements, d. are reliable in operation and provide an increased sense of security to the user, and e. are readily adaptable to a wide variety of vehicle designs and requirements.
[0018] These and other objects of the present invention are attained in the provision of a retractable entry system for fifth wheel travel trailers wherein the storage width of the retracted system is limited not by the horizontal dimension of the storage space in the vehicle but, rather, by the vertical dimension of the storage space, thus becoming larger as the height of the interior floor increases. Specifically, the retractable entry system is powered to extend and retract along a plurality of spaced-apart rotatable axes, in sequential, reciprocating arcs of motion. With the first axis and in the first of the sequences of motion when retracting, a portion of the step assembly folds onto another portion of the step assembly. With the second axis and in the second of the sequences of motion in retraction, the folded step assembly rotates from a horizontal to a vertical orientation. The completed sequences of motion allow the retracted entry systems to fit between the outer side wall of a vehicle and the vehicle chassis. The present invention allows the entry system to include at least four steps down from the vehicle entry door and multiple, independent drive motors for powered actuation without decreasing vehicle ground clearance.
[0019] In a broader sense, the present invention applies multiple directions of motion in the retraction process, either sequentially or concurrently, such that an otherwise limiting dimension of the entry system (such as its width) can be manipulated into an orientation with respect to the vehicle that does not require an inconvenient storage space dimension within the vehicle. This invention is applicable with a variety of different retraction structures for entry systems, including accordion-fold (reciprocating arcs of motion, as shown further below), scissor arms, and parallelogram linkage formats. In each case, the structure supporting the steps is compacted and that compacted arrangement is then moved by rotation or otherwise to a more desirable storage orientation with respect to the vehicle. While manual actuation entry systems can employ the present invention with some advantages, power actuated entry systems can employ the present invention with particular advantages, since at least some of the additional spacial constraints, which would be caused by power drive motors and actuators, are alleviated.
[0020] Other objects, advantages, and novel features of the present invention will become readily apparent from the drawings and detailed description below.
BRIEF DESCRIPTION OF THE DRAWINGS
[0021] FIG. 1 shows a front, left side perspective plant view of an exemplary fifth wheel travel trailer having an embodiment of the present invention therein, with the retractable entry system in a fully retracted position.
[0022] FIG. 2 shows an enlarged front, left side perspective view of a portion of an exemplary fifth wheel travel trailer having an embodiment of the present invention therein, with the retractable entry system in a fully extended position and with an adjacent travel trailer slide out room in an extended position.
[0023] FIG. 3 shows a top, front, right side perspective view of an exploded assembly of a preferred embodiment of the present invention (the “right” side being with respect to a head on view of the retractable entry assembly, rather than the vehicle as a whole).
[0024] FIG. 4 shows a top, front end view of the assembled embodiment of FIG. 3 .
[0025] FIG. 5 shows a top, front, right side perspective view of the assembled embodiment of FIG. 3 with the retractable entry system in a fully extended position.
[0026] FIG. 6 shows a top, front, right side perspective view of the assembled embodiment of FIG. 3 with the retractable entry system in a partially retracted position in the first of the sequences of motion during retraction, a portion of the step assembly starting to fold onto another portion of the step assembly.
[0027] FIG. 7 shows a top, front, right side perspective view of the assembled embodiment of FIG. 3 with the retractable entry system in a partially retracted position in the first of the sequences of motion during retraction, a portion of the step assembly folded onto another portion of the step assembly.
[0028] FIG. 8 shows a right side “X-Ray” view of the assembled embodiment of FIG. 3 with the retractable entry system in the position shown in FIG. 7 .
[0029] FIG. 9 shows a right side “X-Ray” view of the assembled embodiment of FIG. 3 with the retractable entry system in a partially retracted position in the second of the sequences of motion during retraction, where the folded step assembly is partially rotated toward the vertical, storage position.
[0030] FIG. 10 shows a right side “X-Ray” view of the assembled embodiment of FIG. 3 with the retractable entry systems in a fully retracted position.
DETAILED DESCRIPTION OF PREFERRED EMBODIMENTS
[0031] FIG. 1 shows and exemplary fifth wheel travel trailer A, having front hitch B, wheels C, fully retracted slide-out rooms D, and entry door E, folded door assist handle F, a retractable entry system G in a retracted and stowed position, and a stabilizing jack H lowered to the ground, as if readying for vehicle travel or if the vehicle had just stopped traveling. FIG. 2 shows and enlarged view of a portion of such a travel trailer A, with slide-out room D extended, door assist handle F unfolded, and retractable entry system G in an extended position to facilitate access to entry door E, with an additional stabilizing jack H 1 lowered to the ground, as if the vehicle was park and ready for use of its interior. The following description is provided with respect to preferred embodiments of retractable entry system G.
[0032] In general, entry system G is characterized by a plurality of steps, numbered 101 - 104 on the drawings. Typically, each step would be approximately eight increases wide, in the direction shown as “Ws” on step 101 in FIG. 3 (although in certain situations the present invention may allow the step width to be substantially increased). Typically, each step would be positioned within the entry system such that when the entry system is fully extended into the “down” position, as it is shown to be in FIG. 2 , the vertical drop between the tread portion or tops of the steps would be eight to ten inches, in the direction shown as “Dr” between steps 103 and 104 in FIG. 4 . In the example shown in the drawings, four steps are used. However, it should be understood that the present invention is readily adaptable to use with different numbers of steps, as may be desired in a given application.
[0033] FIG. 3 shows an exploded view of preferred embodiments of the present invention where the accordion fold motion of retraction is used. Steps 101 - 104 are framed at their ends by Parts 1 - 4 , numbered also walls 111 - 114 in the drawings. Walls 111 and 112 are connected to steps 101 and 012 by any convenient conventional means, such as welding. Walls 113 and 114 are similarly connected to steps 103 and 104 .
[0034] Walls 111 and 113 are, for example, rotatably connected by axle pin 115 through alignment of opening 117 in wall 111 and opening 118 in wall 113 . One or more plastic washers 116 can be used in a conventional manner to assist in that connection. Stop pin 119 , mounted through opening 120 in wall 113 is included to provide a predetermined stop against further rotation of wall 113 with respect to wall 111 when that pin engages notch 121 in wall 111 .
[0035] Walls 112 and 114 are, for example, rotatably connected by drive bushing 125 through alignment of opening 126 in wall 114 and opening 127 in wall 112 . Stop pin 128 , mounted through opening 129 in wall 114 is included to provide a predetermined stop against further rotation of wall 114 with respect to wall 112 when that pin engages notch 130 in wall 112 .
[0036] Drive bushing 125 is selectively rotated by motor 135 , which can, for example, be a Klauber brand motor, such as part number K525. The controls for such a motor are located remotely from the entry system in any desired manner, including of conventional construction, and are not shown herein, suffice that when the motor is actuated, bushing 125 is rotated in one direction or another along axis of rotation 132 , as desired for retraction or extension of the steps of the entry system, as describe further herein. Motor 135 includes a rotatable drive shaft 137 for engagement with drive bushing 125 . Motor 135 is, for example, mounted to wall 112 via bracket 139 , in a conventional manner, such as by welding of that bracket to the wall. Motor 135 can be replaced with another type of drive or actuation device in other applications, as desired for cost considerations and as is suited to the particular “folding” or compaction structure or motion used with the steps.
[0037] Wall 111 is rotatably connected to chassis side 141 , and wall 112 is rotatably connected to chassis side 142 . These connections are, for example, accomplished through passage of cylindrical rod 143 through opening 144 in side 141 and opening 145 in wall 111 at one end of rod 143 , and through opening 146 in side 142 and opening 147 in wall 112 at the other end of rod 143 . If desired, plastic washers 148 can be used to facilitate that connection of rod 143 , as in a conventional manner. The connection of rod 143 between walls 111 and 112 and sides 141 and 142 is such that those walls are rotatable with respect to those sides about axis 149 .
[0038] Sides 141 and 142 are, for example, joined and maintained in fixed relation to each other by top bracket 150 . Sides 141 and 142 and/or bracket 150 can be mounted, in a conventional manner, to the supporting structure of vehicle A behind outer side wall S and adjacent the chassis of the vehicle, shown, for example, as I-beam I in FIG. 8 . Sides 141 and 142 can be formed with flanges 151 to assist in mounting to vehicle A. As shown in FIGS. 6 and 7 , those flanges 151 are optional, and as shown in FIGS. 8-10 , flanges 151 can be formed at different positions.
[0039] Stop rod 152 is mounted at one end to wall 111 through opening 154 and at its other end to wall 112 through opening 156 . Stop rod 152 serves to limit the rotation of walls 111 and 112 with respect to sides 141 and 142 and, preferably, permit walls 111 and 112 to be locked into position with respect to sides 141 and 142 at specified locations, such as when the entry system is in a fully extended position for use in facilitating entry to the vehicle. To assist in that regard, a pivotable spring lock 160 is mounted via spring lock pin 162 in side 141 . Spring lock 160 is formed to include a portion 164 which can releasably receive and retain a portion of stop rod 152 . Spring lock 160 can be selectively actuated by a variety of conventional means, as desired in a given application, including by manual levers, spring tensioned cables, electrical solenoids, etc. Thus, spring lock 160 can be actuated either or both at the point of pivot pin 162 or remotely, as from inside the vehicle.
[0040] In the embodiment shown in the drawings, for a power actuated entry system, a linear actuator drive member 165 , for example, is connected between top bracket 150 and bottom bracket 170 . One such actuator which can be suitable in certain applications is a commercially available PPD 1394 actuator. In other applications, various other drive members can be used and connected at the same or various other locations between the components of entry system G, such that wall members 111 and 112 are caused to move, rotatably about axis 149 or another suitably placed axis, for example, with respect sides 141 and 142 . As with motor 135 , drive member 165 can be replaced with another type of drive or actuation device in other applications, as desired for cost considerations and as is suited to the particular “folding” or compaction structure or motion used with the steps. Also, the controls for such a drive member are located remotely from the entry system in any desired manner, including of conventional construction, and are not shown herein, suffice that when the drive member is actuated, walls 111 and 112 are rotated in one direction or another along axis of rotation 149 , as desired for retraction or extension of the entry system with respect to the vehicle, as describe further herein. Actuation of motor 135 and drive member 165 can be coordinated to operate sequentially by a push of a button from either the interior and/or exterior of the vehicle and/or from a hand-held remote control or the like. Electrical programming of such coordinated actuation can be by conventional or other means, as desired in a given embodiment. Similarly, the locking or releasing action of spring lock 160 can be automatically coordinated with respect to the actuation sequence of entry system G.
[0041] In certain applications of the present invention, the motor and drive member can, for example, have sufficient security and reliability that stop pins and/or a spring lock are not needed. In other applications, the use of stop pins and/or a spring lock can be used to relieve pressure on the motor and/or drive member. In manual applications of the present invention, the motor and drive member can be omitted. In certain applications, it may be possible to arrange a single motor or drive member to provide the desired motion for the entire entry system, but with multiple motors it may be possible to significantly reduce the torque and/or power requirements (and thereby lower the costs and/or increase the component useful life) for such a single motor or drive system. Further, the power source for motor 135 and linear actuator 165 can be from any source, electrical or hydraulic, for example, as desired in a given application.
[0042] The operation of retraction of the entry system of the present invention is, for example, established in two phases or sequences of motion. In many applications, those sequences occur one after the other, at different times. However, in given applications it may be possible for both sequences to occur concurrently at the same time. In the first sequence of motion, the entry system moves from a fully extended position, such as shown in FIG. 5 , through a closing position, shown in FIG. 6 , with steps 103 and 104 rotating upwardly about axis 132 (clockwise, if viewed from the right side of entry system G) to a folded position, shown in FIGS. 7 and 8 , having those steps lay face to face (or tread to tread) with steps 102 and 101 , respectively, along arc 180 . In the drawings, arc 180 is approximately 180 degrees of rotation from the extended position to the folded position.
[0043] In the second of the sequences of motion, the entry system moves from the folded position to the fully closed position, as shown in FIGS. 8-10 . This is accomplished, for example, by rotating walls 111 and 112 downwardly about axis 149 (counterclockwise, if viewed from the right side of entry system G), along arc 185 . In the drawings, arc 185 is approximately 90 degrees of rotation from the folded position to the closed position. At that closed point, the tread surfaces of steps 101 - 104 are now, preferably, nearly vertical. Any debris or ice which may have adhered to those tread surfaces has an increased tendency to fall off automatically, especially of the vehicle is in motion to a new location before the entry system is actuated to an extended position again.
[0044] In combination, these two sequences of motion follow reciprocating arcs, collapsing the step structure in two different directions or motions, an “accordion motion,” in effect. Thus, the necessary storage width of even the folded step structure is not just reduced, it is displaced from the horizontal plane to a more spacious plane, in this case the vertical plane (often made more spacious because of the raise interior floor of the vehicle). Therefore, the same vehicle design changes which require additional steps can be used to provide the additional storage space for those steps, without having to specially alter the vehicle chassis of interior floor space.
[0045] Moreover, spacial advantage is also provided by establishing the rotational axis 149 for walls 111 and 112 near the outermost edges of walls 111 and 112 and sides 141 and 142 , as shown in the drawings, in effect cantilevering the step construction to a large extent both the walls and the sides. Thus, as the folded step assembly is rotated downward about axis 149 , it is moved back into the space formed within sides 141 and 142 , without significant interference or restriction from portions of the walls remaining there. Conversely, when the entry system is fully extended, less material is needed for walls 111 and 112 to provide the fullest step projection horizontally from the vehicle side wall, thus keeping component weight and cost lower.
[0046] Another way of looking at the present invention is that it has provided a simplified means for the horizontal width of the step structure to be compacted into nearly the total step drop dimension, “Dr,” of only half of its steps. The present application has been described and shown with respect to vehicles, namely travel trailers, but it is certainly also applicable to aircraft, marine vehicles, and static structures where a retractable step or entry system is needed but must contend with special storage envelope concerns. In such other applications, it may be advantageous for the usually sequences of motion to be reversed, even if they are not simultaneous, such that during retraction the folding of the steps upon each other occurs after the entry system is rotated toward the side wall of the item it is mounted to.
[0047] Accordingly, while the present invention has been described and shown herein with respect to certain particular embodiments, that was done by way of illustration and example only. Another example of an application for the present invention would be where the door opening is not elevated, but rather lowered with respect to the location where the user would start to access the door. Therefore, the spirit and scope of the present invention are intended to be limited only by the terms of the attached claims.
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A retractable entry system is provided which is powered to extend and retract along a plurality of spaced-apart rotatable axes, in sequential, reciprocating arcs of motion. With the first axis and in the first of the sequences of motion when retracting, a portion of the step assembly folds onto another portion of the step assembly, the steps being aligned tread to tread. With the second axis and in the second of the sequences of motion in retraction, the folded step assembly rotates from a horizontal to a vertical orientation against and into the supporting vehicle. The completed sequences of motion allow the retracted entry systems to fit between the outer side wall of a vehicle and the vehicle chassis.
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BACKGROUND AND SUMMARY
[0001] This invention relates to the casting of metal strip by continuous casting in a twin roll caster.
[0002] In a twin roll caster, molten metal is introduced between a pair of counter-rotated horizontal casting rolls that are cooled so that metal shells solidify on the moving roll surfaces and are brought together at a nip between them to produce a solidified strip product delivered downwardly from the nip between the rolls. The term “nip” is used herein to refer to the general region at which the rolls are closest together. The molten metal may be poured from a ladle into a smaller vessel or series of smaller vessels from which it flows through a metal delivery nozzle located above the nip, so forming a casting pool of molten metal supported on the casting surfaces of the rolls immediately above the nip and extending along the length of the nip. This casting pool is usually confined between side plates or dams held in sliding engagement with end surfaces of the rolls so as to dam the two ends of the casting pool against outflow.
[0003] Further, the twin roll caster may be capable of continuously producing cast strip from molten steel through a sequence of ladles. Pouring the molten metal from the ladle into smaller vessels before flowing through the metal delivery nozzle enables the exchange of an empty ladle with a full ladle without disrupting the production of cast strip.
[0004] In casting thin strip by twin roll caster, the unpredictability of the crown in the casting surfaces of the casting rolls during a casting campaign is a difficulty. The crown of the casting surfaces of the casting rolls determines the thickness profile, i.e., cross-sectional shape, of thin cast strip produced by the twin roll caster. Casting rolls with convex (i.e., positive crown) casting surfaces produced cast strip with a negative (depressed) cross-sectional shape, and casting rolls with concave (i.e., negative crown) casting surfaces produced cast strip with a positive (i.e., raised) cross-sectional shape. The casting rolls generally are formed of copper or copper alloy with internal passages for circulation of cooling water usually coated with chromium or nickel to form the casting surfaces, which undergo substantial thermal deformation with exposure to the molten metal.
[0005] In thin strip casting, there is a desired roll crown to produce a desired strip cross-sectional profile under typical casting conditions. It is usual to machine the casting rolls with an initial crown when cold based on the projected crown in the casting surfaces of the casting rolls under typical casting condition. However, the differences between the crown shape of the casting surfaces between cold and casting conditions is difficult to predict. Moreover, the actual crown of the casting surfaces during the casting campaign can vary significantly from that projected crown under typical conditions, since the crown of the casting surfaces of the casting rolls can change even during typical casting due to changes in the temperature of molten metal supplied to the casting pool of the caster, changes in casting speed and other casting conditions, and even with slight changes in the composition of the molten metal as occurs during casting.
[0006] Accordingly, there has been a need for a reliable and effective way to directly and closely control the shape of the crown in the casting surfaces of the casting rolls during casting, and in turn, the cross-sectional profile of the thin cast strip produced by the twin roll caster. Previous proposals for casting roll crown control have relied on mechanical devices to physically deform the casting roll, e.g., by the movement of deforming pistons or other elements within the casting roll or by applying bending forces to the support shafts of the casting rolls. Yet, there has not been an effective way to dynamically control the roll crown to produce the desired profile of the cast strip until now.
[0007] We have determined that reliable and effective control of the casting roll crown and, in turn, cross-sectional strip profile can be achieved by providing a casting roll of such configuration to enable control of the crown in the casting surfaces by varying casting parameters.
[0008] Disclosed is a method of continuously casting thin strip dynamically controlling roll crown comprising the steps of:
[0009] a. assembling a caster having a pair of counter rotating casting rolls with a nip there between capable of delivering cast strip downwardly from the nip, where each casting roll has a casting surface formed by a cylindrical tube of a material selected from the group consisting of copper and copper alloy optionally with a coating thereon and having a plurality of longitudinal water flow passages extending through the tube having a thickness of no more than 80 millimeters, the cylindrical tube capable of changing crown of the casting surface with changes in temperature of water flowing through the passages during casting,
[0010] b. assembling a metal delivery system capable of forming a casting pool supported on the casting surfaces of the casting rolls above the nip with side dams adjacent ends of the nip to confine the casting pool,
[0011] c. positioning at least one sensor capable of sensing thickness profile of the cast strip downstream of the nip and generating electrical signals indicative of the thickness profile of the cast strip,
[0012] d. controlling the temperature of the water flowing through the longitudinal water flow passages in the tube thickness,
[0013] e. counter rotating the casting rolls and varying the speed of the casting rolls with a casting roll drive system, and
[0014] f. controlling the casting roll drive to vary the speed of rotation of the casting rolls and varying the temperature of the water flow circulated through the water flow passages by a control system responsive to electrical signals received from the sensors to control roll crown of the casting rolls during a casting campaign.
[0015] The cylindrical tube of each casting roll is of a circumferential thickness that, by varying the casting speed and controlling the temperature of the water circulated through the casting rolls, the crown in the casting surfaces of the casting can reliably be varied to achieve and maintain a desired cross-sectional profile of the cast strip. The thickness of the cylindrical tubemay range between 40 and 80 millimeters in thickness or between 60 and 80 millimeters in thickness. The casting rolls may have a cavity internal of the cylindrical tube to define the thickness of the cylindrical tube and facilitate flexure of the cylindrical tube to provide crown control with changes in casting speed and temperature of water circulated through the casting rolls. Water may be circulated through the water flow passages and the cavities of the casting rolls in series. Alternatively, water may be circulated through the water flow passages and then through the cavity of at least one of the casting rolls, or water may be circulated through the cavity and then through the water flow passages of at least one of the casting rolls.
[0016] Also disclosed is an apparatus for continuously casting thin strip by dynamically controlling roll crown comprising:
[0017] a. a caster having a pair of counter rotating casting rolls with a nip there between capable of delivering cast strip downwardly from the nip where each casting roll has a casting surface formed by a cylindrical tube of a material selected from the group consisting of copper and copper alloy optionally with a coating thereon and has a plurality of longitudinal water flow passages extending through the tube having a thickness of no more than 80 millimeters, the cylindrical tube capable of changing crown of the casting surface with changes in temperature of water flowing through the passages during casting,
[0018] b. a metal delivery system capable of forming a casting pool supported on the casting surfaces of the casting rolls above the nip with side dams adjacent ends of the nip to confine the casting pool,
[0019] c. at least one sensor capable of sensing thickness profile of the cast strip downstream of the nip and generating electrical signals indicative of the thickness profile of the cast strip,
[0020] d. a water flow controller capable of controlling the temperature of the water flowing through the longitudinal water flow passages in the tube thickness,
[0021] e. a casting roll drive system capable of counter rotating the casting rolls and varying the speed of the casting rolls during casting, and
[0022] f. a control system responsive to electrical signals received from the sensors capable of controlling the casting roll drive to vary the speed of rotation of the casting rolls and controlling the water flow controller to vary the temperature of the water flow circulated through the water flow passages to control roll crown of the casting rolls during a casting campaign.
[0023] Again, the cylindrical tube may have an internal cavity to define the cylindrical tube and provide for flexure thereof as described above. Tube may be between 40 and 80 millimeters in thickness or between 60 and 80 millimeters in thickness.
[0024] The longitudinal water flow passages in the tube thickness may be arranged in three pass sets round the cylindrical tube thickness, so that the cooling water circulates through the three passages of the set in series before exiting the casting roll either directly or through the internal cavity. Alternatively, the longitudinal water flow passages in the tube thickness may be arranged in single pass sets round the cylindrical tube thickness so that the cooling water circulates through one passage before exiting the casting roll either directly or through the internal cavity.
[0025] At least one sensor capable of sensing thickness profile of the cast strip may be adjacent to pinch rolls through which the strip first passes after casting. A plurality of sensors capable of sensing thickness profile of the cast strip may be positioned laterally across the strip.
[0026] Various aspects of the invention will become apparent to those skilled in the art from the following detailed description, drawings and claims.
BRIEF DESCRIPTION OF THE DRAWINGS
[0027] The invention is described in more detail in reference to the accompanying drawings in which:
[0028] FIG. 1 is a diagrammatical side view of a twin roll caster of the present disclosure;
[0029] FIG. 2 is an enlarged partial sectional view of a portion of the twin roll caster of FIG. 1 including a strip inspection device for measuring strip profile;
[0030] FIG. 2A is a schematic view of a portion of twin roll caster of FIG. 2 ;
[0031] FIG. 3A is a cross sectional view longitudinally through a portion of one of the casing rolls of FIG. 2 ;
[0032] FIG. 3B is a cross sectional view longitudinally through the remaining portion of the casing roll of FIG. 3A joined on line A-A;
[0033] FIG. 4 is an end view of the casting roll of FIG. 3A on line 4 - 4 shown in partial interior detail in phantom;
[0034] FIG. 5 is a cross sectional view of the casting roll of FIG. 3A on line 5 - 5 ;
[0035] FIG. 6 is a cross sectional view of the casting roll of FIG. 3A on line 6 - 6 ;
[0036] FIG. 7 is a cross sectional view of the casting roll of FIG. 3A on line 7 - 7 ;
[0037] FIG. 8 is a schematic illustration of the twin casting rolls of FIG. 2 with a water supply system;
[0038] FIG. 9 is a schematic illustration similar to FIG. 8 with the water supply in an alternative configuration;
[0039] FIG. 10 is a graph illustrating maximum roll surface temperature to water inlet temperature for three different flows rates;
[0040] FIG. 11 is a graph illustrating strip crown to roll surface temperature for two different casting speeds;
[0041] FIG. 12 is a graph illustrating roll surface temperature across a part of the width of a casting roll;
[0042] FIG. 13 is a graph illustrating heat flux to edge distance for the casting roll of FIG. 12 ;
[0043] FIG. 14 is a graph illustrating thermal crown to edge distance for the casting roll of FIG. 12 ;
[0044] FIG. 15 is a graph illustrating heat flux attenuation to casting speed;
[0045] FIG. 16 is a graph illustrating water flow rate and water temperature at an inlet to time;
[0046] FIG. 17 is a graph illustrating strip gauge and roll crown to edge distance for a casting roll; and
[0047] FIG. 18 is a graph illustrating strip gauge and roll crown to edge distance for another casting roll.
DETAILED DESCRIPTION
[0048] Referring now to FIGS. 1 , 2 , and 2 A, a twin roll caster is illustrated that comprises a main machine frame 10 that stands up from the factory floor and supports a pair of counter-Rota table casting rolls 12 mounted in a module in a roll cassette 11 . The casting rolls 12 are mounted in the roll cassette 11 for ease of operation and movement as described below. The roll cassette 11 facilitates rapid movement of the casting rolls 12 ready for casting from a setup position into an operative casting position in the caster as a unit, and ready removal of the casting rolls 12 from the casting position when the casting rolls 12 are to be replaced. There is no particular configuration of the roll cassette 11 that is desired, so long as it performs that function of facilitating movement and positioning of the casting rolls 12 as described herein.
[0049] The casting apparatus for continuously casting thin steel strip includes the pair of counter-Rota table casting rolls 12 having casting surfaces 12 A laterally positioned to form a nip 18 there between. Molten metal is supplied from a ladle 13 through a metal delivery system to a metal delivery nozzle 17 , core nozzle, positioned between the casting rolls 12 above the nip 18 . Molten metal thus delivered forms a casting pool 19 of molten metal above the nip 18 supported on the casting surfaces 12 A of the casting rolls 12 . This casting pool 19 is confined in the casting area at the ends of the casting rolls 12 by a pair of side closure plates, or side dams 20 , (shown in dotted line in FIGS. 2 and 2A ). The upper surface of the casting pool 19 (generally referred to as the “meniscus” level) may rise above the lower end of the delivery nozzle 17 so that the lower end of the delivery nozzle 17 is immersed within the casting pool 19 . The casting area includes the addition of a protective atmosphere above the casting pool 19 to inhibit oxidation of the molten metal in the casting area.
[0050] The ladle 13 typically is of a conventional construction supported on a rotating turret 40 . For metal delivery, the ladle 13 is positioned over a movable tundish 14 in the casting position to fill the tundish 14 with molten metal. The movable tundish 14 may be positioned on a tundish car 66 capable of transferring the tundish 14 from a heating station (not shown), where the tundish 14 is heated to near a casting temperature, to the casting position. A tundish guide, such as rails 39 , may be positioned beneath the tundish car 66 to enable moving the movable tundish 14 from the heating station to the casting position.
[0051] The movable tundish 14 may be fitted with a slide gate 25 , actuable by a servo mechanism, to allow molten metal to flow from the tundish 14 through the slide gate 25 , and then through a refractory outlet shroud 15 to a transition piece or distributor 16 in the casting position. From the distributor 16 , the molten metal flows to the delivery nozzle 17 positioned between the casting rolls 12 above the nip 18 .
[0052] The side dams 20 may be made from a refractory material such as zirconia graphite, graphite alumina, boron nitride, boron nitride-zirconia, or other suitable composites. The side dams 20 have a face surface capable of physical contact with the casting rolls 12 and molten metal in the casting pool 19 . The side dams 20 are mounted in side dam holders (not shown), which are movable by side dam actuators (not shown), such as a hydraulic or pneumatic cylinder, servo mechanism, or other actuator to bring the side dams 20 into engagement with the ends of the casting rolls 12 . Additionally, the side dam actuators are capable of positioning the side dams 20 during casting. The side dams 20 form end closures for the molten pool of metal on the casting rolls 12 during the casting operation.
[0053] FIG. 1 shows the twin roll caster producing the cast strip 21 , which passes across a guide table 30 to a pinch roll stand 31 , comprising pinch rolls 31 A. Upon exiting the pinch roll stand 31 , the thin cast strip 21 may pass through a hot rolling mill 32 , comprising a pair of work rolls 32 A, and backup rolls 32 B, forming a gap capable of hot rolling the cast strip 21 delivered from the casting rolls 12 , where the cast strip 21 is hot rolled to reduce the strip to a desired thickness, improve the strip surface, and improve the strip flatness. The work rolls 32 A have work surfaces relating to the desired strip profile across the work rolls 32 A. The hot rolled cast strip 21 then passes onto a run-out table 33 , where it may be cooled by contact with a coolant, such as water, supplied via water jets 90 or other suitable means, and by convection and radiation. In any event, the hot rolled cast strip 21 may then pass through a second pinch roll stand 91 to provide tension of the cast strip 21 , and then to a coiler 92 . The cast strip 21 may be between about 0.3 and 2.0 millimeters in thickness before hot rolling.
[0054] At the start of the casting operation, a short length of imperfect strip is typically produced as casting conditions stabilize. After continuous casting is established, the casting rolls 12 are moved apart slightly and then brought together again to cause this leading end of the cast strip 21 to break away forming a clean head end of the following cast strip 21 . The imperfect material drops into a scrap receptacle 26 , which is movable on a scrap receptacle guide. The scrap receptacle 26 is located in a scrap receiving position beneath the caster and forms part of a sealed enclosure 27 as described below. The enclosure 27 is typically water cooled. At this time, a water-cooled apron 28 that normally hangs downwardly from a pivot 29 to one side in the enclosure 27 is swung into position to guide the clean end of the cast strip 21 onto the guide table 30 that feeds it to the pinch roll stand 31 . The apron 28 is then retracted back to its hanging position to allow the cast strip 21 to hang in a loop beneath the casting rolls 12 in enclosure 27 before it passes to the guide table 30 where it engages a succession of guide rollers.
[0055] An overflow container 38 may be provided beneath the movable tundish 14 to receive molten material that may spill from the tundish 14 . As shown in FIG. 1 , the overflow container 38 may be movable on rails 39 or another guide such that the overflow container 38 may be placed beneath the movable tundish 14 as desired in casting locations. Additionally, an optional overflow container (not shown) may be provided for the distributor 16 adjacent the distributor 16 .
[0056] The sealed enclosure 27 is formed by a number of separate wall sections that fit together at various seal connections to form a continuous enclosure wall that permits control of the atmosphere within the enclosure 27 . Additionally, the scrap receptacle 26 may be capable of attaching with the enclosure 27 so that the enclosure 27 is capable of supporting a protective atmosphere immediately beneath the casting rolls 12 in the casting position. The enclosure 27 includes an opening in the lower portion of the enclosure 27 , lower enclosure portion 44 , providing an outlet for scrap to pass from the enclosure 27 into the scrap receptacle 26 in the scrap receiving position. The lower enclosure portion 44 may extend downwardly as a part of the enclosure 27 , the opening being positioned above the scrap receptacle 26 in the scrap receiving position. As used in the specification and claims herein, “seal,” “sealed,” “sealing,” and “sealingly” in reference to the scrap receptacle 26 , enclosure 27 , and related features may not be a complete seal so as to prevent leakage, but rather is usually less than a perfect seal as appropriate to allow control and support of the atmosphere within the enclosure 27 as desired with some tolerable leakage.
[0057] A rim portion 45 may surround the opening of the lower enclosure portion 44 and may be movably positioned above the scrap receptacle 26 , capable of sealingly engaging and/or attaching to the scrap receptacle 26 in the scrap receiving position. The rim portion 45 may be movable between a sealing position in which the rim portion 45 engages the scrap receptacle 26 , and a clearance position in which the rim portion 45 is disengaged from the scrap receptacle 26 . Alternately, the caster or the scrap receptacle 26 may include a lifting mechanism to raise the scrap receptacle 26 into sealing engagement with the rim portion 45 of the enclosure 27 , and then lower the scrap receptacle 26 into the clearance position. When sealed, the enclosure 27 and scrap receptacle 26 are filled with a desired gas, such as nitrogen, to reduce the amount of oxygen in the enclosure 27 and provide a protective atmosphere for the cast strip 21 .
[0058] The enclosure 27 may include an upper collar portion 43 supporting a protective atmosphere immediately beneath the casting rolls 12 in the casting position. When the casting rolls 12 are in the casting position, the upper collar portion 43 is moved to the extended position closing the space between a housing portion 53 adjacent the casting rolls 12 , as shown in FIG. 2 , and the enclosure 27 . The upper collar portion 43 may be provided within or adjacent the enclosure 27 and adjacent the casting rolls 12 , and may be moved by a plurality of actuators (not shown) such as servo-mechanisms, hydraulic mechanisms, pneumatic mechanisms, and rotating actuators.
[0059] The casting rolls 12 are internally water cooled as described below so that as the casting rolls 12 are counter-rotated, shells solidify on the casting surfaces 12 A, as the casting surfaces 12 A move into contact with and through the casting pool 19 with each revolution of the casting rolls 12 . The shells are brought close together at the nip 18 between the casting rolls 12 to produce a thin cast strip product 21 delivered downwardly from the nip 18 . The thin cast strip product 21 is formed from the shells at the nip 18 between the casting rolls 12 and delivered downwardly and moved downstream as described above.
[0060] The construction of each of the two casting rolls 12 is generally the same as described with reference to FIGS. 3A , 3 B, and 4 - 7 . Each casting roll 12 includes a cylindrical tube 120 of a metal selected from the group consisting of copper and copper alloy, optionally with a coating thereon, e.g., chromium or nickel, to form the casting surfaces 12 A. Each cylindrical tube 120 may be mounted between a pair of stub shaft assemblies 121 and 122 . The stub shaft assemblies 121 and 122 have end portions 127 and 128 , respectively (shown in FIGS. 4 - 6 ),which fit snugly within the ends of cylindrical tube 120 to form the casting roll 12 . The tube cylindrical 120 is thus supported by end portions 127 and 128 having flange portions 129 and 130 , respectively, to form internal cavity 163 therein, and support the assembled casting roll between the stub shaft assemblies 121 and 122 .
[0061] The outer cylindrical surface of each cylindrical tube 120 is a roll casting surface 12 A. The cylindrical thickness of the cylindrical tube 120 may be no more than 80 millimeters thick so that crown of the outer surface of the cylindrical tube 120 can be controlled by controlling the casting speed and the temperature of the cooling water circulates through the casting roll as described below. The thickness of the tube 120 may range between 40 and 80 millimeters in thickness or between 60 and 80 millimeters in thickness.
[0062] Each cylindrical tube 120 is provided with a series of longitudinal water flow passages 126 , which may be formed by drilling long holes through the circumferential thickness of the cylindrical tube 120 from one end to the other. The ends of the holes are subsequently closed by end plugs 141 attached to the end portions 127 and 128 of stub shaft assemblies 121 and 122 by fasteners 171 . The water flow passages 126 are formed through the thickness of the cylindrical tube 120 with end plugs 141 . The number of stub shaft fasteners 171 and end plugs 141 may be selected as desired. End plugs 141 may be arranged to provide, with water passage in the stub shaft assemblies described below, in single pass cooling from one end to the other of the roll 12 , or alternatively, to provide multi-pass cooling where, for example, the flow passages 126 are connected to provide three passes of cooling water through adjacent flow passages 126 before returning the water to the water supply directly or through the cavity 163 .
[0063] The water flow passages 126 through the thickness of the cylindrical tube 120 may be connected to water supply in series with the cavity 163 . The water passages 126 may be connected to the water supply so that the cooling water first passes through the cavity 163 and then the water supply passages 126 to the return lines, or first through the water supply passages 126 and then through the cavity 163 to the return lines.
[0064] The cylindrical tube 120 may be provided with circumferential steps 123 at end to form shoulders 124 with the working portion of the roll casting surface 12 A of the roll 12 there between. The shoulders 124 are arranged to engage the side dams 20 and confine the casting pool 19 as described above during the casting operation.
[0065] End portions 127 and 128 of stub shaft assemblies 121 and 122 , respectively, typically sealingly engage the ends of cylindrical tube 120 and have radially extending water passages 135 and 136 shown in FIGS. 4-6 to deliver water to the water flow passages 126 extending through the cylindrical tube 120 . The radial flow passages 135 and 136 are connected to the ends of at least some of the water flow passages 126 , for example, in threaded arrangement, depending on whether the cooling is a single pass or multi-pass cooling system. The remaining ends of the water flow passages 126 may be closed by, for example, threaded end plugs 141 as described where the water cooling is a multi-pass system.
[0066] As shown in detail by FIG. 7 , cylindrical tube 120 may be positioned in annular arrays in the thickness of cylindrical tube 120 either in single pass or multi-pass arrays of water flow passages 126 as desired. The water flow passages 126 are connected at one end of the casting roll 12 by radial ports 160 to the annular gallery 140 and in turn radially flow passages 135 of end portion 127 in stub shaft assembly 120 , and are connected at the other end of the casting roll 12 by radial ports 161 to annular gallery 150 and in turn radial flow passages 136 of end portions 128 in stub shaft assembly 121 . Water supplied through one annular gallery, 140 or 150 , at one end of the roll 12 can flow in parallel through all of the water flow passages 126 in a single pass to the other end of the roll 12 and out through the radial passages, 135 or 136 , and the other annular gallery, 150 or 140 , at that other end of the cylindrical tube 120 . The directional flow may be reversed by appropriate connections of the supply and return line(s) as desired. Alternatively or additionally, selective ones of the water flow passages 126 may be optionally connected or blocked from the radial passages 135 and 136 to provide a multi pass arrangement, such as a three pass.
[0067] The stub shaft assembly 122 may be longer than the stub shaft assembly 121 , and the stub shaft assembly 122 provided with two sets of water flow ports 133 and 134 . Water flow ports 133 and 134 are capable of connection with rotary water flow couplings 131 and 132 by which water is delivered to and from the casting roll 12 axially through stub shaft assembly 122 . In operation, cooling water passes to and from the water flow passages 126 in the cylindrical tube 120 through radial passages 135 and 136 extending through end portions 127 and 128 of the stub shaft assemblies 121 and 122 , respectively. The stub shaft assembly 121 is fitted with axial tube 137 , to provide fluid communication between the radial passages 135 in end portions 127 and the central cavity within the casting roll 12 . The stub shaft assembly 122 is fitted with axial space tube 138 , to separate a central water duct 138 , in fluid communication with the central cavity 163 , and from annular water flow duct 139 in fluid communication with radial passages 136 in end portion 122 of stub shaft assembly 122 . Central water duct 138 and annular water duct 139 are capable of providing inflow and outflow of cooling water to and from the casting roll 12 . In operation, incoming cooling water may be supplied through supply line 131 to annular duct 139 through ports 133 , which is in turn in fluid communication with the radial passages 136 , gallery 150 and water flow passages 126 , and then returned through the gallery 140 , the radial passages 135 , axial tube 137 , central cavity 163 , and central water duct 138 to outflow line 132 through water flow ports 134 . Alternatively, the water flow to, from and through the casting roll 12 may be in the reverse direction as desired. As discussed in more detail below, the water flow ports 133 and 134 may be connected to water supply and return lines so that water may flow to and from water flow passages 126 in the cylindrical tube 120 of the casting roll 12 in either direction, as desired. Depending on the direction of flow, the cooling water flows through the cavity 163 either before or after flow through the water flow passages 126 .
[0068] FIG. 8 illustrates one arrangement in which cooling water may be supplied to the casting rolls 12 in a closed loop system. A pump 151 delivers water through a supply line 152 to the ports 133 of one casting roll 12 , and to the ports 134 of the other casting roll 12 . By this arrangement, water is delivered to the radial passages 135 at one end of one casting roll 12 and to the radial passages 136 at the other end of the second casting roll 12 . Water flows from the other ports, 134 and 133 respectively, through a discharge line 153 to a heat exchanger 154 and back to the pump 151 through a return line 155 . Both of the casting rolls 12 may receive cooling water from the common supply pump 151 at essentially the same temperature, although such is not required. However, water is delivered to the flow passages 126 of one casting roll 12 through cavity 163 , and discharge from the flow passages 126 of the other casting roll 12 through cavity 163 . By this arrangement, differential expansion due to a temperature difference across one casting roll 12 tends to be offset by differential expansion of the other casting roll 12 due to the mutual reversal of the flow direction to the two rolls 12 .
[0069] It is understood, however, that the water flow pattern and direction may be chosen as desired. For example, the direction of water flow may be the same in both casting rolls 12 by connection of the water supply in an arrangement illustrated in FIG. 9 . Components illustrated in FIG. 9 that are similar to FIG. 8 . However, in FIG. 9 , the water supply line 152 is connected to the ports 133 of both rolls 12 and the discharge line 153 is connected to the ports 134 of both rolls 12 .
[0070] The systems illustrated in FIGS. 8 and 9 may be operated to control the crown of the casting surfaces 12 A of the casting rolls 12 . In operation, deformation of the crown of the casting surfaces 12 A may be controlled by regulating the temperature of the cooling water flowing through the water flow passages 126 of the cylindrical tube 120 or controlling the speed of rotation of the casting rolls 12 with heat flux attenuation of the ends of the casting roll. In turn, the thickness profile of cast strip 21 can be controlled with the control of the crown of the casting surfaces 12 A of the casting rolls 12 . Since the circumferential thickness of the cylindrical tube 120 is made to a thickness of no more than 80 mm, the crown of the casting surfaces 12 A may be made to deform responsive to changes in the temperature of the cooling water or change in speed of the casting rolls with heat flux attenuation of the ends of the casting roll. As previously explained, the thickness of the cylindrical tube 120 may range between 40 and 80 millimeters in thickness or between 60 and 80 millimeters in thickness.
[0071] To control the temperature of the cooling water and casting speed to achieve a desired strip thickness profile, a strip thickness profile sensor 71 may be positioned downstream to detect the thickness profile of the cast strip 21 as shown in FIGS. 2 and 2A . The strip thickness sensor 71 is provided typically between the nip 18 and the pinch rolls 31 A to provide for direct control of the casting roll 12 . The sensor may be an x-ray gauge or other suitable device capable of directly measuring the thickness profile across the width of the strip periodically or continuously. Alternatively, a plurality of non-contact type sensors are arranged across the cast strip 21 at the roller table 30 and the combination of thickness measurements from the plurality of positions across the cast strip 21 are processed by a controller 72 to determine the thickness profile of the strip periodically or continuously. The thickness profile of the cast strip 21 may be determined from this data periodically or continuously as desired.
[0072] FIGS. 10-18 are a series of graphs obtained from a twin roll caster similar to that illustrated in FIGS. 1-9 . In several runs, the caster was operated at different set casting speeds, and with cooling water supplied at different inlet temperatures during the course of a casting run at each casting speed. In the twin roll caster utilized in these runs, the casting rolls comprised a cylindrical tube of copper alloy having an outer peripheral diameter of 489.6 mm, a length of 1400 mm and a circumferential thickness of 64.5 mm.
[0073] FIG. 10 is a graph illustrating the maximum measured roll surface temperature increases with increasing water inlet temperature at three different water flow rates. FIG. 10 also shows that the maximum measured roll surface temperature at a given water inlet temperature increases with decreasing water flow rate.
[0074] FIG. 11 is a graph of strip thickness profile (strip crown) versus average measured roll surface temperature (i.e. the average roll surface temperature measured across the width of the roll) at two casting roll speeds. FIG. 11 shows that strip thickness profile reduces with increasing average measured roll temperature, as roll crown increases. Thus, strip thickness profile can be varied and controlled with the casting roll temperature and correlated water inlet temperature. FIG. 11 also shows that at a given casting roll temperature, the thickness profile (strip crown) markedly decreases with decreasing casting speed and heat flux attenuation of the ends of the casting roll as discussed below in relation to FIGS. 12-14 .
[0075] FIG. 12 is a graph of roll surface temperature across a part of the casting roll width in millimeters from one end of the casting roll, with the casting roll operating at a substantially constant casting speed. The graph illustrates that there is a substantial increase in casting roll surface temperature, of the order of 30° C., from the end of the casting roll to a position approximately 150 mm inboard of the end of the casting roll.
[0076] FIG. 13 shows heat flux versus distance from the end of the casting roll. The variable heat flux curve is derived from calculations of the data set forth in the graph in FIG. 12 . The constant heat flux curve is the theoretical limit which the heat flux approaches at the end of the strip with increase in casting speed. The variable heat flux curve in FIG. 13 illustrates significant attenuation of the heat flux at the ends of the casting roll with actual casting.
[0077] FIG. 14 illustrates the effect of the end heat flux attenuation shown in FIG. 13 . FIG. 14 is a graph of change in casting surface configuration (roll crown) with distance from the end of the casting roll for the roll operation that generated the data illustrated in FIGS. 12 and 13 , i.e., for variable heat flux across the width of the roll, and for casting roll operation with a constant heat flux generated across the width of the roll. FIG. 14 shows the difference between the casting roll crown in the central section of a casting roll operating under variable heat flux compared to a constant heat flux. We have also found that with the heat flux lower at the end of a casting roll compared to 150 millimeters from the ends of the roll, more constraint to the overall axial expansion of the casting roll and greater radial expansion results at the center of the casting roll, i.e., greater roll crown, in the central section of the casting roll and a reduced thickness profile of the strip. In other runs, similar results have been obtained with different casting speeds, with the results showing greater heat flux attenuation with decreasing casting speed.
[0078] FIG. 15 is a graph of heat flux attenuation versus casting speed. The graph illustrates our finding that when casting occurs at lower casting speeds, the temperature profile of the crown in the surface of a casting roll over the last 150 millimeters from the side edge increases (even though the average temperature of the casting roll is lower). This has the effect of constraining the cylindrical tube of the casting roll, increasing diameters in the central section of the casting roll, and thus causing the casting roll to “belly out” or “crown up” more for a given heat flux than when the casting roll was rotating faster. This results in a corresponding decrease in the strip cross-sectional profile due to the increased roll crown.
[0079] FIG. 16 is a graph illustrating a cooling water temperature increase from 27° C. to 32° C. during the course of particular casting run carried out at a constant casting speed. The graph of FIG. 16 also shows an analysis of the strip produced by the caster before and after the water inlet temperature change. Coil # 1 was cast strip at a selected time in the casting run before the water inlet temperature change, and Coil # 2 was cast strip at a selected time in the casting run after the water inlet temperature change. In both cases the cast strip was analyzed to determine the thickness profile at that point in the casting run.
[0080] FIGS. 17 and 18 show the strip thickness profiles for the two tested sections of strip identified as Coil # 1 and Coil # 2 in FIG. 16 . The graphs in FIGS. 17 and 18 illustrate that with a relatively higher cooling water temperature (Coil # 2 ) the magnitude of the thickness perturbations, e.g. ridges, is lower than for a relatively lower cooling water temperature (Coil # 1 ). The graphs in FIGS. 17 and 18 also illustrate that there is significant localized variations in strip thickness profile in strip produced by the caster prior to the increase in water temperature, which was significantly reduced with increase in water temperature. The localized variations in strip thickness are evident from the series of ridges (which indicate local thickness variations) across the width of the strip in each of the graphs in FIGS. 17 and 18 . Controlling the temperature of the casting roll with change of the water inlet temperature demonstrates control for the shape of the roll crown and the strip thickness profile, as well as control over the range of localized variations in strip thickness profile. At a relatively higher cooling water temperature, the casting rolls expand more than at a relatively lower cooling water temperature and thus “crown up” more, thereby bringing the two cast shells of the thin cast strip closer together and reduce strip thickness profile. In this example, there is less molten metal being carried between the two shells in the cast strip with higher water temperature, than was the case with lower water temperatures where the two cast shells were farther apart and had greater bulging and different magnitude of ridges.
[0081] These examples illustrate control of the casting speed and the temperature of cooling water can control the crown of the casting surfaces of the casting rolls.
[0082] While principles and modes of operation have been explained and illustrated with regard to particular embodiments, it must be understood, however, that the invention may be practiced otherwise than as specifically explained and illustrated without departing from its spirit or scope.
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A method of continuously casting thin strip dynamically controlling roll casting surface configuation by controlling the temperature of water flowing through the longitudinal water flow passages in a cyclindrical tube thickness of no more than 80 millimeters of counter rotated casting rolls, and varying the speed of the casting rolls with attenuation of the ends of the casting rolls with a casting roll drive system responsive to electrical signals received from sensors during a casting campaign.
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This nonprovisional application claims priority under 35 U.S.C. §119(a) to German Patent Application No. DE 10 2010 003 864.4, which was filed in Germany on Apr. 12, 2010, and which is herein incorporated by reference.
BACKGROUND OF THE INVENTION
1. Field of the Invention
The invention relates to a device for reducing corrosive constituents in an exhaust gas condensate of an internal combustion engine, in which the exhaust gas of the internal combustion engine is recirculated to the internal combustion engine via an exhaust gas recirculation system, having an exhaust gas cooler and at least one exhaust gas recirculation line.
2. Description of the Background Art
In components for conducting exhaust gas, particularly exhaust gas coolers and charge-air coolers in low-pressure exhaust gas recirculation systems, corrosive exhaust gas condensate is produced when the temperature drops below the dew point. This corrosive exhaust gas condensate can produce corrosive effects in the components downstream and in the combustion engine itself, resulting in damage to or even failure of the components or the internal combustion engine, which come into contact with the corrosive exhaust gas condensate.
When condensate forms, strong acids are produced, which have a corrosive effect on the metallic surfaces of the exhaust gas recirculation system or the internal combustion engine.
EP 2 161 438 A2 describes a system for recirculating exhaust gas of an internal combustion engine, which has a separator unit. This separator unit separates condensate, and the condensate that is separated from the exhaust gas is discharged partially to a low pressure part of the exhaust gas system via a disposal line. Also provided is a metering unit, which introduces a definable amount of the condensate or at least of the components of the condensate into an air supply inlet channel of the combustion cylinder of the internal combustion engine.
From DE 10 2005 047 840 A1, which corresponds to U.S. Publication No. 20070261400, an air-cooled exhaust gas heat exchange system is known, in which channels for conducting the exhaust gas are embodied as tubes. Between the channels, ribs are arranged for air cooling, which are made of stainless steel and are therefore protected against corrosion.
DE 10 2005 059 717 A1, which corresponds to U.S. Publication No. 20080190403, and which describes a heat exchange device for acid-containing gases. The device comprises a heat exchanger having at least one flow channel for the acid-containing gas, which channel is made substantially of aluminum and/or an aluminum alloy and is embodied in such a way that the flow channel is protected against deep corrosion caused by the acid-containing gas, resulting in a uniform protection of components.
SUMMARY OF THE INVENTION
It is therefore an object of the present invention to provide a device for reducing corrosive constituents in an exhaust gas condensate of an internal combustion engine, in which the components of the exhaust gas recirculation system and/or the intake air components and the internal combustion engine are protected against the corrosive effects of the exhaust gas condensate, whereby the device can also be easily produced.
According to an embodiment of the invention, the problem is solved in that the exhaust gas recirculation system comprises at least one neutralization unit for neutralizing the corrosive constituents of the exhaust gas condensate, which unit is connected to at least one component arranged downstream, through which the exhaust gas, which has been nearly freed of corrosive constituents, flows. This offers the advantage that the neutralization unit produces a constant and targeted neutralization of the corrosive components of the exhaust gas condensate, thereby protecting the components of the exhaust gas recirculation system that lie downstream, the intake air components and/or the internal combustion engine itself against corrosion and mechanical wear caused by the corrosive particles.
The neutralization unit, in a region through which the exhaust gas flows, can have a surface made of a material that reacts chemically with the corrosive constituents of the exhaust gas condensate. The chemically reactive material chemically bonds with the acid constituents of the exhaust gas condensate and removes them from the region of the chemically reactive material. This chemical reaction of the corrosive constituents with the material takes place directly at the site where the condensate forms, or as close as possible downstream thereof. The resulting reaction products do not settle on the surface of the neutralization unit, therefore allowing subsequent exhaust gas condensate access to the reactive surface of the neutralization unit.
In another embodiment, the neutralization unit can be produced entirely from the material which reacts chemically with the corrosive constituents of the exhaust gas condensate. The reaction products produced by the chemical reaction are readily soluble in the liquid-containing condensate and are therefore easily transported away from the surface. The reactive surface is thus rapidly opened up for the subsequent exhaust gas condensate containing corrosive constituents. The continuous wearing away of the reactive surface allows the formation of a protective layer to be dispensed with.
In a further embodiment, the surface of the neutralization unit made of the chemically reactive material which is in contact with the exhaust gas is embodied as fine grained and can have a particle size of less than 50 μm. The small particle size results particularly in a low probability of damage to the components situated downstream in the direction of flow. As a result of the more advantageous surface to volume ratio, the reaction products are also more easily partially dissolved or dissolved in the exhaust gas condensate, wherein the corrosion products are no longer present as a solid constituent.
In one variant, the fine-grained surface of the neutralization unit is applied to a material having a coarse grain structure. Using an open-pored material, such as cast material, and applying the fine-grained surface to this coarse-grained material allows inexpensive materials to be used as the base material for the neutralization unit, resulting in a cost-effective embodiment.
In addition to neutralizing the exhaust gas, or the corrosive constituents contained in the exhaust gas condensate, the described material properties for generating very small particles represent a significant functional property of the neutralization unit.
In a variant, the material is a metallic material, preferably aluminum and alloys thereof and/or zinc and alloys thereof. Such alloys allow ready solubility of the reaction products in the exhaust gas condensate, which is achieved particularly by using alloy combinations, such as zinc alloys.
In an variant, the material includes a wrought aluminum or alloys thereof.
The chemically reactive material can include aluminum alloyed with a portion of zinc. The alloyed zinc portion makes the surface of the neutralization unit, which is in contact with the exhaust gas condensate, less noble than a purely aluminum surface, causing it to react more readily with the medium. By alloying the material with zinc, the electric potential difference between the less noble surface and the core material can be increased to greater than 70 mV. In comparison, a tubular material with zinc-free solder plating and the aforementioned aluminum core material has an electric potential difference of less than 30 mV. The higher the electric potential difference between surface and core material, the more preferable and uniform is the neutralization on the surface. In addition, deep corrosion is prevented in this manner.
In a further embodiment, the neutralization unit can be formed by at least a part of the exhaust gas cooler and/or a charge-air cooler and/or the exhaust gas recirculation line. Thus, components contained in the exhaust gas recirculation system can themselves be used as the neutralization unit. These entire components, or only parts thereof which come in contact with the exhaust gas condensate, are made of the chemically reactive material. Alternatively, these parts can simply be coated with the appropriate chemically reactive material. In this manner, a particularly cost-effective solution can be achieved.
Advantageously, the region of the neutralization unit through which the exhaust gas flows can have a small hydraulic diameter of preferably 200 mm, particularly <20 mm, in particular <6 mm, as compared with the cross-section through which the gas flows freely. The hydraulic diameter is a measurement of the amount of surface area that is used in proportion to the cross-section of the component that is used. The smaller the hydraulic diameter, the more surface area is available for reacting the exhaust gas condensate with the chemically reactive material. Therefore, to achieve a sustained reduction in the corrosive constituents of the exhaust gas condensate, the largest possible surface area must be available.
Advantageously, the region of the neutralization unit through which the exhaust gas flows has a large reactive surface area, which is preferably implemented in the form of ribs, lands or winglets.
To remove the reaction products from the region of the chemically reactive material, it is necessary for the exhaust gas condensate to have the highest possible volumetric flow rate. To achieve a high velocity gradient, the region of the neutralization unit through which the exhaust gas flows is configured such that the exhaust gas flowing through achieves Reynolds numbers of >2300, particularly as a result of installed turbulence inserts. In order for the reaction products to be removed from the reactive exhaust gas condensate, said products have the lowest possible weight and a small surface area.
In a further embodiment, the neutralization unit can be embodied as replaceable. This is advantageous particularly if the neutralization unit has only one surface that is coated with the chemically reactive material. Because this coating is consumed over time due to a limited coating thickness, it is expedient to install a new neutralization unit once this surface has been completely worn away. This will ensure that the effect of neutralizing the corrosive constituents in the exhaust gas condensate is continuously maintained.
In an embodiment, the neutralization unit can have at least one threaded and/or plug-type connection for the replaceable anchoring of the unit in the exhaust gas recirculation system. Such customary threaded or plug-type connections allow the neutralization unit to be easily replaced in the existing exhaust gas recirculation system.
A further embodiment of the invention relates to a method for reducing corrosive constituents of an exhaust gas condensate in an internal combustion engine, in which the exhaust gas of the internal combustion engine is recirculated to the internal combustion engine via an exhaust gas recirculation system, wherein, when the temperature drops below a predefined level, a corrosive exhaust gas condensate forms. To protect the internal combustion engine and the constituents of the exhaust gas recirculation system from the aggressive constituents of the exhaust gas condensate, the corrosive constituents of the exhaust gas condensate are neutralized continuously in at least one region of the exhaust gas recirculation system, wherein the exhaust gas, which has been nearly freed of the exhaust gas condensate, is recirculated to the internal combustion engine via at least one component of the exhaust gas recirculation system situated downstream. The targeted neutralization of the corrosive constituents of the exhaust gas condensate reliably protects the exhaust gas recirculation system along with the intake air components and the internal combustion engine from corrosive effects. The small particle size of the reaction products eliminates mechanical abrasion by these reaction products on the interior surfaces of the components situated downstream.
Further scope of applicability of the present invention will become apparent from the detailed description given hereinafter. However, it should be understood that the detailed description and specific examples, while indicating preferred embodiments of the invention, are given by way of illustration only, since various changes and modifications within the spirit and scope of the invention will become apparent to those skilled in the art from this detailed description
BRIEF DESCRIPTION OF THE DRAWINGS
The present invention will become more fully understood from the detailed description given hereinbelow and the accompanying drawings which are given by way of illustration only, and thus, are not limitive of the present invention, and wherein:
FIG. 1 illustrates a high-pressure exhaust gas recirculation system;
FIG. 2 illustrates a mixed exhaust gas recirculation system;
FIG. 3 illustrates a low-pressure exhaust gas recirculation system;
FIG. 4 illustrates an air-cooled exhaust gas neutralization unit;
FIG. 5 illustrates an exhaust gas neutralization unit cooled with cooling water;
FIG. 6 illustrate various cross-sections of a flow channel of an exhaust gas neutralization unit according to FIG. 2 ; and
FIG. 7 is a water solubility table.
DETAILED DESCRIPTION
Similar features are identified by the same reference signs.
In today's vehicles, particularly in commercial vehicles, exhaust gas coolers are used for cooling recirculated exhaust gases within the framework of an exhaust gas recirculation system (EGR system). The recirculation of exhaust gas is based upon legislative regulations regarding the reduction of pollutants (particularly NO x ) in exhaust gases from internal combustion engines.
FIGS. 1 to 3 show an exhaust gas recirculation system for a diesel motor, which is driven by a turbocharger. The turbocharger 1 has two turbo machines, a turbine and a compressor. The turbine utilizes the energy contained in the exhaust gas to drive the compressor, which draws in fresh air and forces precompressed air into the cylinders of the diesel motor 5 . The turbocharger 1 is energetically coupled to the diesel motor 5 only via the mass flow of air and exhaust gas.
In FIG. 1 , the turbocharger 1 is connected via a charge-air line 2 to a charge-air cooler 3 . The charge-air cooler 3 leads via a suction line 4 directly to the diesel motor 5 . The diesel motor 5 is coupled again to the turbocharger 1 via an exhaust gas line 6 , and to the exhaust gas cooler 7 via a branch line. The exhaust gas cooler 7 leads via a first exhaust gas recirculation line 8 to the suction line 4 of the diesel motor 5 . This configuration is a high-pressure exhaust gas recirculation system.
FIG. 2 shows a similar arrangement, which represents a mixed exhaust gas recirculation system. In this illustration, as before, the turbocharger 1 is connected via the charge-air line 2 to the charge-air cooler 3 , which is connected via the suction line 4 to the diesel motor 5 . The internal combustion engine 5 supplies its exhaust gas to the turbocharger 1 and to the exhaust gas cooler 7 via the exhaust gas line 6 . In this case, the exhaust gas cooler 7 is connected to the charge-air line 2 via a second exhaust gas recirculation line 9 . In this variant, therefore, the exhaust gas condensate provided by the exhaust gas cooler 7 is supplied together with the charge air to the charge-air cooler 3 , where it is cooled. This mixture of charge air and exhaust gas condensate is supplied via the suction line 4 to the diesel motor 5 .
FIG. 3 shows a low-pressure exhaust gas recirculation system, in which the turbocharger 1 leads via the charge-air line 2 to the charge-air cooler 3 , which is in turn connected via the suction line 4 to the diesel motor 5 . The exhaust gases from the diesel motor 5 are supplied via the exhaust gas line 6 to the turbocharger 1 , which discharges the exhaust gases into the environment. In contrast to the preceding FIGS. 1 and 2 , in FIG. 3 , the exhaust gas is fed via the third exhaust gas recirculating line 10 to the exhaust gas cooler 7 , wherein the third exhaust gas recirculating line 10 is connected to the turbocharger 1 output on the side of discharge to the environment. Also in this case, the exhaust gas cooler 7 introduces exhaust gases via the second exhaust gas recirculation line 9 into the charge-air line 2 , where the two are mixed and are supplied to the charge-air cooler 3 for cooling.
For all three described exhaust gas recirculation systems, there are two possible embodiments for a neutralization unit. In one embodiment, only regions of the exhaust gas recirculation system can be equipped with a coating having a material that reacts chemically with the corrosive constituents of the exhaust gas condensate. Surfaces suitable for neutralization are thereby created, which in this context have metallic materials such as zinc and alloys thereof or aluminum and alloys thereof. Ordinarily, AA7XXX (aluminum alloy with zinc portions), or zinc-containing alloys with the aluminum material groups AA4XXX (aluminum silicon), AA3XXX (aluminum manganese) or AA1XXX are used for this purpose. The chosen ratio of zinc alloy is greater than 0.5 percent by weight, preferably greater than 1%.
Alloying with zinc makes the surface less noble than a pure aluminum surface, and therefore more readily reactive with the medium. The resulting reaction products are readily soluble in the medium and are thus easily removed from the surface, thereby opening up sufficient new reactive surface. Continuous abrasion of the reactive surface without formation of a protective layer.
The ready solubility of the reaction products in the medium is achieved particularly by using the aforementioned alloy or alloy combinations, such as alloys with zinc.
For instance, it is clear from Table H that in the exhaust gas condensate containing sulfuric acid, the solubility of zinc is 50% greater than that of aluminum (630 g/l to 965 g/l). In aqueous solutions, which result, for example, from the formation of hydroxides with OH groups, the solubility of zinc is significantly greater than that of aluminum, at 0.21 g/l to 0.0015 g/l.
The reactive surface should be as large as possible to ensure the most complete neutralization of exhaust gas condensate, and the exhaust gas recirculation lines 8 , 9 , 10 should be configured so as to optimize flow in order to achieve the most uniform possible impingement of the reactive surface with the exhaust gas condensate. In FIGS. 1 to 3 , the regions of the exhaust gas recirculation lines 8 , 9 , 10 or the suction line 4 of the diesel motor 5 in question are identified by dashed arrows C, D, E.
In another variant, however, the exhaust gas cooler 7 or the charge-air cooler 3 can be produced entirely from the chemically reactive material, and can therefore serve as neutralization unit A or B.
FIG. 4 shows an air-cooled exhaust gas neutralization unit 11 in the form of a charge-air cooler. This air-cooled exhaust gas neutralization unit 11 has an exhaust gas intake 12 and an exhaust gas outlet 13 . The exhaust gas containing a high percentage of exhaust gas condensate flows through the gas intake 12 into the exhaust gas neutralization unit 11 and is guided through the exhaust gas neutralization unit 11 along the arrow F. It then exits the exhaust gas neutralization unit 11 at the exhaust gas outlet 13 . The cooling air strikes the exhaust gas neutralization unit 11 perpendicular in a cross-flow, as illustrated by the arrow G. An exhaust gas neutralization unit 11 of this type is made of aluminum or one of the above-described aluminum alloys. It serves to neutralize the corrosive constituents contained in the exhaust gas.
In the case of a cooled exhaust gas recirculation system, it is advantageous for the reactive surface to be provided in the form of the exhaust gas heat exchanger itself, as this will ensure that the condensate is largely neutralized directly at its site of formation, thereby protecting the components situated downstream.
FIG. 5 a shows an exhaust gas neutralization unit 14 which is cooled with cooling water. The cooling water flows into the cooling water-cooled exhaust gas neutralization unit 14 via the port 15 and moves along the flow direction A inside the exhaust gas neutralization unit 14 , and is then discharged from the exhaust gas neutralization unit 14 via the cooling water outlet 16 . The exhaust gas containing a high percentage of exhaust gas condensate flows into the exhaust gas neutralization unit 14 via the exhaust gas intake line 17 , and is discharged from the exhaust gas neutralization unit 14 at the exhaust gas outlet 18 .
FIG. 5 b shows a cross-section of the flow channel 19 of the cooling water-cooled exhaust gas neutralization unit 14 . Said cross-section has a radial geometry in the diameter of the flow channel 19 . The radially extending lands 19 a enlarge the surface area for reaction with the exhaust gas condensate. In the present case, the entire interior surface of the flow channel, including the radial lands, is made of aluminum or zinc or alloys thereof.
FIG. 6 shows various cross-sections of another flow channel 20 , which is also made of aluminum or alloys thereof, and/or zinc or alloys thereof.
FIG. 6 a shows a flow channel 20 which has extruded parts 21 , each of which has a rectangular cross-section and thereby forms a large surface area. Because multiple such extruded parts are arranged side by side, the exhaust gas condensate is constantly subjected to the neutralization process. The resulting reaction products are removed from the reaction region by the liquid solution which forms the exhaust gas condensate, so that subsequent exhaust gas condensate, which contains the corrosive constituents, can again react with the same surfaces.
FIG. 6 b illustrates winglets 22 . These are impressed areas, which ensure turbulence in the exhaust gas flow. FIG. 6 c shows ribs 23 , which can be produced as a rolled or stamped embodiment. This arrangement also ensures a large surface area in the flow channel 20 . One particularly simple variant of the embodiment of the flow channel 20 with an enlarged surface area is illustrated in FIG. 6 d , where the profiles are achieved with round tubes 24 . With suitable impressions for producing a swirling effect, the surface and turbulence of these tubes can be further increased.
With the constant neutralization of the corrosive constituents of the exhaust gas condensate, which is provided in the exhaust gas cooler 7 , and with the small particle size of the reaction products, which are produced by the exhaust gas condensate reacting with the chemically reactive materials, such as aluminum or an aluminum/zinc alloy, and can therefore be immediately removed from the reaction region, the components 3 , 4 , 8 , 9 , 10 downstream of the neutralization unit 7 , or the diesel motor 5 , can be comprehensively protected.
To allow the reaction products to be removed from the reacting exhaust gas condensate, said products have the lowest possible weight and a small surface area. If an aluminum alloy is used as the chemically reactive material, the reaction products have a weight of less than 50 μg. This small size of the direct and indirect reaction products is achieved particularly by configuring the neutralization surface of the neutralization unit A, B, C, D, E to be as homogeneous and fine-grained as possible. Indirect reaction products in this case are the material which is dissolved out in a neighboring region as a result of selective corrosion. Neutralization occurs uniformly and in a controlled manner, thereby ensuring that the reactive surface of the neutralization unit A, B, C, D, E is available over the entire lifespan of the product being used, which is achieved particularly by using the highly homogeneous, fine-grained material having the above-described particle size. In this manner, deep corrosion is reliably prevented.
The invention being thus described, it will be obvious that the same may be varied in many ways. Such variations are not to be regarded as a departure from the spirit and scope of the invention, and all such modifications as would be obvious to one skilled in the art are to be included within the scope of the following claims.
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A device for reducing corrosive constituents in an exhaust gas condensate of an internal combustion engine is provided, in which the exhaust gas of the internal combustion engine is recirculated to the internal combustion engine via an exhaust gas recirculation system having an exhaust gas cooler and at least one exhaust gas recirculation line. To protect the exhaust gas recirculation system along with intake air components and the internal combustion engine from the corrosive effects of the exhaust gas condensate, the exhaust gas recirculation system has at least one neutralization unit for neutralizing the corrosive constituents of the exhaust gas condensate, which is connected to at least one component arranged downstream, through which the exhaust gas, which has been freed of nearly all corrosive constituents, flows.
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FIELD OF THE INVENTION
[0001] The present invention relates to improvements in window opening control devices, and more particularly to a device that is capable of limiting the travel of a casement window.
BACKGROUND OF THE INVENTION
[0002] One safety concern for children, with respect to the windows that may be installed into residential homes and other buildings, are its features that may serve to prevent accidental egress and serious injury from a fall. One preventative feature is the height that the windows are installed above the floor, which prevents toddlers from accidentally falling out, and inhibits small children from creatively seeking to observe the outside view from the sill of the window, which could result in an accidental fall therefrom.
[0003] Opening control devices for windows (WOCDs), which serve to releasably limit the travel that a window may undergo to a relatively small amount, which may be roughly four inches, are another feature that has been employed on sliding sash windows for that reason. They have also been utilized thereon to prevent unauthorized entry into the dwelling from the outside by an intruder. However, preventative measures in the form of WOCDs have not been pursued as vigorously for casement windows, which typically are hingedly connected in some fashion to the master window frame.
[0004] As building codes have sought to regulate the construction industry to improve child safety through the use of such devices (see e.g., ASTM F2090-10: “Standard Specification for Window Fall Prevention Devices with Emergency Escape (Egress) Release Mechanisms”), tradeoffs have been proposed to reduce the height restrictions for window installations where such devices are utilized. But such lessening of these window height requirements only serves to place greater importance on the integrity of the WOCDs, particularly their ability to automatically reset themselves, after having been manually released to open the easement window beyond its restricted range of movement.
[0005] The window opening control device of the present invention is uniquely adapted to not only limit the range of travel of the casement window to prevent accidental falls therefrom, and to automatically reset itself, but to also avoid the necessity of having to remove the screen from the window in order for the device to function properly.
OBJECTS OF THE INVENTION
[0006] It is an object of the invention to provide a window opening control device that may releasably limit the travel of a casement window to an amount preventing accidental egress therefrom.
[0007] It is another object of the invention to provide a window opening control device for a casement window that is easily released to permit full travel of the casement window when desired.
[0008] It is a further object of the invention to provide a safety switch for a window opening control device for a casement window that prevents tampering by young children who may seek to impermissibly operate the safety device.
[0009] It is another object of the invention to provide a window opening control device for a casement window that automatically resets the device, after the window has been moved back to the closed position.
[0010] Further objects and advantages of the invention will become apparent from the following description and claims, and from the accompanying drawings.
SUMMARY OF THE INVENTION
[0011] A device may limit opening of a sash window that is hingedly coupled to a master window frame, and may include: a bracket attached to the sash; a first arm having a first end pivotally coupled to the bracket; a second arm having a first end pivotally coupled to the second end of the first arm; a means for biasing the second arm into a retracted position; and a release assembly. The release assembly may be secured within the master window frame and may include a hook member that is pivotable between a first position and a second position.
[0012] With the hook member occupying the first position, the hook portion thereon may be releasably received in an opening in the second end of the second arm, when the first and second arms are in the retracted position, and the sash is closed and received by the master window frame.
[0013] The first arm may normally occupy its retracted position, with respect to the bracket that is fixedly secured to the sash, by rotating downward into a vertically oriented position, and may be limited to that position through the prevention of any over-travel by a stop protruding from the bracket. The second arm may be configured to normally occupy its retracted position, with respect to the vertically oriented first arm and the bracket, by being biased against gravity to rotate upwardly to be positioned, and travel limited by a stop on the first arm, to occupy a somewhat vertical position, being at a small acute angle with respect to the first arm.
[0014] Once the hook portion of the hook member has been releasably received within the opening in the second end of the second arm, as described above, the sash may be opened, and the amount that it may be opened will be travel-limited according to the length of the first and second arms. The sash of the casement window being travel limited in this manner will prevent a small child from accidentally falling through the gap between the sash and the master window frame. When the user desires to open the window even further, the second arm may be disengaged from the hook of the release assembly, by rotating the hook to be in the second position.
[0015] The hook may be configured to extend from a graspable switch member, in order for a user's hand to more easily cause its pivotal movement between the first and second positions. The hook and switch member may be installed directly into a master window frame that is particularly configured to receive its envelope and permit pivotal movement therein, or it may instead be received within a base member that itself is adapted to be received within a simple opening in the master window frame and secured thereat.
[0016] The combination of the switch member and base member may serve to enable additional functionality. The switch member may be configured to receive a spring biased safety button therein, which may be slidable between a protruding position and a depressed position. The safety button may be configured to inhibit pivoting of the switch member and hook combination from its first position, when the button occupies its spring biased outwardly disposed position. When the button is depressed, pivoting of the switch member is no longer inhibited, and it may be pivoted into the second position to release the second arm from the hook member. The helical spring may also have its ends adapted to provide torsional biasing of the switch member relative to the base member, so that when the user releases their grasp of the switch member, it may be biased so that the combination switch member and hook member occupy the first position, and may readily accommodate engagement with the catch assembly.
BRIEF DESCRIPTION OF THE DRAWINGS
[0017] FIG. 1 illustrates a perspective view of the window opening control device of the present invention, installed upon a casement window master frame and its sash window, and with the device being used to releasably secure the window sash to prevent further travel of the opened window beyond the safe limit.
[0018] FIG. 2 illustrates the window opening control device and casement window of FIG. 1 , but with the device having been released to permit further travel of the opened window sash.
[0019] FIG. 2A is an enlarged detail view of the release assembly on the window frame and the catch assembly on the sash, as seen in perspective view of FIG. 1 .
[0020] FIG. 2B is an enlarged detail view of the bracket of the catch assembly of FIG. 1 , showing the possible use of backing plates to accommodate installation on a sash with a different profile.
[0021] FIG. 2C is a side view of the release assembly and a portion of the catch assembly, as installed on the casement window of FIG. 1 .
[0022] FIG. 2D is a front view of the release assembly protruding through the master frame of the casement window of FIG. 2C .
[0023] FIG. 2E is a top view of the release assembly of FIG. 2D , shown by itself.
[0024] FIG. 2F is a perspective view of the release assembly of FIG. 2E , but shown with the switch member cut away.
[0025] FIG. 2G is a bottom perspective view of the switch member.
[0026] FIG. 2H is a perspective view of the assembled hook member, the turning switch, and the safety button of the present invention.
[0027] FIG. 3 illustrates the catch assembly and the release assembly of the window opening control device of FIG. 2 , with the easement window omitted from the view, and with the catch assembly releasably secured to the release assembly, the arms of the catch assembly being in the retracted position, and with the sash having been closed with respect to the master frame.
[0028] FIG. 4 illustrates the catch assembly and the release assembly of the window opening control device of FIG. 3 , but with the arms of the catch assembly shown extended, for when the sash is opened with respect to the master frame, and thereby travel limited.
[0029] FIG. 4A illustrates a reverse perspective view of the release assembly of FIG. 4 , where the safety button has not been depressed.
[0030] FIG. 4B is an enlarged detail view of the release assembly retaining the second arm of the catch assembly, as seen in FIG. 4 .
[0031] FIG. 5 illustrates the catch assembly and the release assembly of the window opening control device of FIG. 4 , but with the safety button having been depressed, and the switch member pivoted to release the hook of the release assembly from the opening of the second arm of the catch assembly.
[0032] FIG. 5A illustrates a reverse perspective view of the release assembly of FIG. 5 , where the safety button has been depressed, and the switch member pivoted.
[0033] FIG. 5B is an enlarged detail view of the release assembly shown in FIG. 5 .
[0034] FIG. 6 illustrates the catch assembly and the release assembly of the window opening control device of FIG. 5 , but with arms of the catch assembly moving into the retracted position as a result of spring biasing.
[0035] FIG. 7 is an exploded view of the parts used for assembly and installation of the opening control device of the present invention.
[0036] FIG. 8 is a perspective view of the bracket of the catch assembly of the opening control device of the present invention.
[0037] FIG. 8A is a front view of the bracket of the catch assembly of FIG. 8 .
[0038] FIG. 8B is a side view of the bracket of the catch assembly of FIG. 8 .
[0039] FIG. 8C is an end view of the bracket of the catch assembly of FIG. 8 .
[0040] FIG. 9 is a perspective view of the first arm of the catch assembly of the opening control device of the present invention.
[0041] FIG. 9A is a front view of the first arm of the catch assembly of FIG. 9 .
[0042] FIG. 9B is a side view of the first arm of the catch assembly of FIG. 9 .
[0043] FIG. 9C is an end view of the first arm of the catch assembly of FIG. 9 .
[0044] FIG. 10 is a perspective view of the second arm of the catch assembly of the opening control device of the present invention.
[0045] FIG. 10A is a front view of the second arm of the catch assembly of FIG. 10 .
[0046] FIG. 10B is a side view of the second arm of the catch assembly of FIG. 10 .
[0047] FIG. 10C is an end view of the second arm of the catch assembly of FIG. 10 .
[0048] FIG. 11 is a perspective view of the torsion spring of the catch assembly of the opening control device of the present invention.
[0049] FIG. 11A is a front view of the torsion spring of the catch assembly of FIG. 11 .
[0050] FIG. 11B is a side view of the torsion spring of the catch assembly of FIG. 11 .
[0051] FIG. 11C is an end view of the torsion spring of the catch assembly of FIG. 11 .
[0052] FIG. 12 is a perspective view of the rivet of the catch assembly of the opening control device of the present invention.
[0053] FIG. 12A is a front view of the rivet of the catch assembly of FIG. 12 .
[0054] FIG. 12B is a side view of the rivet of the catch assembly of FIG. 12 .
[0055] FIG. 12C is an end view of the rivet of the catch assembly of FIG. 12 .
[0056] FIG. 13 is a perspective view of the base member of the release assembly of the opening control device of the present invention.
[0057] FIG. 13A is a front view of the base member of the release assembly of FIG. 13 .
[0058] FIG. 13B is a side view of the base member of the release assembly of FIG. 13 .
[0059] FIG. 13C is an end view of the base member of the release assembly of FIG. 13 .
[0060] FIG. 14 is a perspective view of the switch member of the release assembly of the opening control device of the present invention.
[0061] FIG. 14A is a front view of the switch member of the release assembly of FIG. 14 .
[0062] FIG. 14B is a side view of the switch member of the release assembly of FIG. 14 .
[0063] FIG. 14C is an end view of the switch member of the release assembly of FIG. 14 .
[0064] FIG. 15 is a perspective view of the hook member of the release assembly of the opening control device of the present invention.
[0065] FIG. 15A is a front view of the hook member of the release assembly of FIG. 15 .
[0066] FIG. 15B is a side view of the hook member of the release assembly of FIG. 15 .
[0067] FIG. 15C is an end view of the hook member of the release assembly of FIG. 15 .
[0068] FIG. 16 is a perspective view of the safety button of the release assembly of the opening control device of the present invention.
[0069] FIG. 16A is a front view of the safety button of the release assembly of FIG. 16 .
[0070] FIG. 16B is a side view of the safety button of the release assembly of FIG. 16 .
[0071] FIG. 16C is an end view of the safety button of the release assembly of FIG. 16 .
[0072] FIG. 17 is a perspective view of the spring of the release assembly of the opening control device of the present invention.
[0073] FIG. 17A is a front view of the spring of the release assembly of FIG. 17 .
[0074] FIG. 17B is a side view of the spring of the release assembly of FIG. 17 .
[0075] FIG. 17C is an end view of the spring of the release assembly of FIG. 17 .
[0076] FIG. 18A shows the decal of the exploded view of FIG. 7 that may be used to position holes on the sash for proper positioning thereon of the catch assembly of the opening control device of the present invention.
[0077] FIG. 18B shows the decal of FIG. 18B being further used to coordinate the hole positions on the sash with proper positioning of the holes on the master window frame, for proper mounting thereon of the release assembly.
[0078] FIG. 19 is an exploded view of the parts forming a second embodiment of the opening control device of the present invention, including a V-shaped torsion spring.
[0079] FIG. 20 illustrates the catch assembly and the release assembly of the second embodiment of the window opening control device of the present invention, with the casement window omitted from the view, and with the catch assembly releasably secured to the release assembly, the arms of the catch assembly being in the retracted position, and with the sash having been closed with respect to the master frame.
[0080] FIG. 21 illustrates the catch assembly and the release assembly of the window opening control device of FIG. 20 , but with the arms of the catch assembly shown extended, for when the sash is opened with respect to the master frame, and thereby travel limited.
[0081] FIG. 22 is a first perspective view of the base member of the release assembly of the second embodiment of the opening control device of the present invention.
[0082] FIG. 22A is a second perspective view of the base member of FIG. 22 .
[0083] FIG. 22B is a third perspective view of the base member of FIG. 22 .
[0084] FIG. 22C is a fourth perspective view of the base member of FIG. 22 .
[0085] FIG. 22D is a fifth perspective view of the base member of FIG. 22 .
[0086] FIG. 22E is a sixth perspective view of the base member of FIG. 22 .
[0087] FIG. 23 is a front view of the base member of FIG. 22 .
[0088] FIG. 23A is a rear view of the base member of FIG. 22 .
[0089] FIG. 24 is a first side view of the base member of FIG. 22 .
[0090] FIG. 24A is a second side view of the base member of FIG. 22 .
[0091] FIG. 25 is an end view of the base member of FIG. 22 .
[0092] FIG. 26 is a first perspective view of the switch member of the release assembly of the second embodiment of the opening control device of the present invention.
[0093] FIG. 26A is a second perspective view of the switch member of FIG. 26 .
[0094] FIG. 26B is a third perspective view of the switch member of FIG. 26 .
[0095] FIG. 26C is a fourth perspective view of the switch member of FIG. 26 .
[0096] FIG. 26D is a fifth perspective view of the switch member of FIG. 26 .
[0097] FIG. 26E is a sixth perspective view of the switch member of FIG. 26 .
[0098] FIG. 27 is a front view of the switch member of FIG. 26 .
[0099] FIG. 27A is a rear view of the switch member of FIG. 26 .
[0100] FIG. 28 is a first side view of the switch member of FIG. 26 .
[0101] FIG. 28A is a second side view of the switch member of FIG. 26 .
[0102] FIG. 29 is a first end view of the switch member of FIG. 26 .
[0103] FIG. 29A is a second end view of the switch member of FIG. 26 .
[0104] FIG. 30 is a perspective view of the hook member of the release assembly of the second embodiment of the opening control device of the present invention.
[0105] FIG. 31 is a front view of the hook member of FIG. 30 .
[0106] FIG. 32 is a side view of the hook member of FIG. 30 .
[0107] FIG. 33 is an end view of the hook member of FIG. 30 .
[0108] FIG. 34 is a perspective view of the torsion spring of the catch assembly of the release assembly of the second embodiment of the opening control device of the present invention.
[0109] FIG. 35 is a front view of the torsion spring of FIG. 34 .
[0110] FIG. 36 is a side view of the torsion spring of FIG. 34 .
[0111] FIG. 37 is an end view of the torsion spring of FIG. 34 .
DETAILED DESCRIPTION OF THE INVENTION
[0112] FIG. 1 illustrates a perspective view of the catch assembly of the window opening control device of the present invention having been installed upon a master frame and sash of a casement window. The device is being used thereon to releasably secure the sash to the master frame to prevent further travel of the opened window sash beyond the safe limit. Depressing of a safety button and pivoting of a switch member causes release of the device to permit further travel of the opened window sash, as seen in FIG. 2 .
[0113] The two main assemblies of the opening control device of the present invention are seen in the enlarged detail view of FIG. 2A , and consist of the catch assembly 100 , and the release assembly 200 . The catch assembly 100 and release assembly 200 may be secured to the sash window 11 and the master window frame 21 , respectively, and are discussed further hereinafter.
[0114] The catch assembly 100 may consist of a bracket 110 , a first arm 120 , a second arm 130 , and a torsion spring 140 . The bracket 110 is shown in detail within FIGS. 8-8C . Bracket 110 may be a generally flat plate that may be pocketed to reduce weight in-between certain features that are necessary to enable use of the bracket. Bracket 110 may include a pair of mounting holes 111 A and 111 B, which may be formed with a countersink to accommodate flush head mounting screws therein, in order to suitably mount the bracket to the side of the sash 11 . A hole 112 in the bracket 110 may be used for pivotal mounting thereto of the first arm 120 , which may be pivotally mounted using a rivet 159 , or other suitable pivotal fastening means. The bracket 110 may include a protruding stop member thereon, which may be used to limit travel of the pivotally mounted first arm 120 with respect to the bracket, when the arm is in the retracted position. The mounting holes 111 A and 111 B may be symmetrically positioned in the bracket, and may be symmetrically positioned with respect to the hole 112 that is used for pivotal mounting of the first arm 120 , which may be centered therein. With the hole 112 being centrally positioned, the pivotal stop may be located towards one end of the bracket 110 , to reduce loading of those features of the bracket. In order to be able to use the bracket for mounting to either a left-hand or a right-hand sash of the casement window, there may be a first pivotal stop 113 A located at one end of the bracket 110 , and a second pivotal stop 113 B located at the other end of the bracket. Each of the stops 113 A and 113 B of bracket 110 of the catch assembly 100 may have a “V” shaped cavity formed by a slanted surface 113 S ( FIG. 8 ) of the stop, which works for guiding automatic alignment of the first arm 120 when the catch assembly 100 is biased back towards the sash 11 , and thereafter the stop 113 completely inhibits further rotation of the first arm 120 at the fully retracted position with respect to bracket 110 .
[0115] The first arm 120 is shown in detail in FIGS. 9-9C , and may be an elongated thin plate member, which may be formed of plastic, metal, or any other suitable material. Proximate to the first end 121 of the arm 120 may be a hole 123 usable for pivotal mounting of the arm to the hole 112 of bracket 110 . Hole 123 may be an eccentric or slotted hole, through which the first arm 120 is riveted with the bracket 110 of catch assembly 100 via the rivet 159 . It provides free movements of the first arm 120 in all directions when the first arm 120 retracts to the sash 11 when the catch assembly 100 is unlocked from the release member 200 . Proximate to the second end 122 of the first arm 120 may be a hole 124 for the pivotal mounting thereto of the second arm 130 . Also proximate to the second end 122 may be a recess 126 in the side of the plate, which may be generally flat at a central portion. The first arm 120 may have a stop 125 positioned thereon to be in proximity to hole 124 . The stop could simply be a mechanical fastener that is fastened to the plate, such as a rivet or a nut and bolt. Alternatively, the stop could be a protrusion that is integral with the plate or bonded thereto, or the stop could be a portion of the plate being stamped and raised to protrude beyond the flat plane of one side of the arm. The latter option is shown in FIG. 9A , which may be seen to produce a straight edge for the stop that may generally be aligned with the position of the edge of the second arm 130 where it is to be restrained in the retracted position.
[0116] The second arm 130 is seen in detail within FIGS. 10-10C , and may, in general, be constructed similar to first arm 120 . Second arm 130 may be an elongated thin flat plate member, with a hole 133 proximate to its first end 131 , to be usable for pivotal mounting of the second arm to hole 124 of the first arm 120 . At the first end 131 of the second arm 130 , a small protrusion 134 may protrude orthogonally from the side of the arm, and may be formed by any of the means cited above for producing stop 125 . The protrusion 134 shown within FIG. 10 is shown as a small tab at the first end 131 that is bent at roughly a 90 degree angle. The protrusion 134 works as a stop to limit the over rotation of the second arm 130 with respect to the first arm 120 , and is received in the recess 126 of the first arm 120 when the sash is to maximum limit opening position, which his discussed further hereinafter. The second end 132 of the second arm 130 may have a shaped opening 135 therein, which may be generally rectangular, and which may further have a notch 135 N therein, both of which are discussed later as to the operation of the opening control device.
[0117] The pivotal mounting of the second arm 130 to the first arm 120 may utilize a simple rivet or other mechanical fastener, and one of many different varieties of springs, which may be a tension spring or a torsion spring. Merely to be exemplary, use of torsion spring 140 and rivet 150 is utilized herein. An exemplary torsion spring 140 is illustrated within FIGS. 11-11C , and may include a small number of helical windings 140 W or even just a portion of one winding that may terminate in a first end 141 via a radial portion 141 R, and in a second end 142 . The first and second ends 141 and 142 may be used to bias the second arm 130 with respect to the first arm 120 . (An alternative V-shaped torsion spring 340 is disclosed hereinafter discussed alternate embodiment).
[0118] In this exemplary arrangement, a rivet 150 , which is shown in detail within FIGS. 12-12C , may have a first post 151 extending from the head 153 , and a second post 152 telescoping therefrom. Pivotal mounting of the first and second arms 120 and 130 may be achieved by first receiving the helical windings 140 W of the torsion spring 140 upon the first post 151 of rivet 150 , such that its radial portion 141 R of the first end 141 is received through opening 153 P in the head 153 of the rivet 150 (see FIG. 7 and FIG. 3 ). Next, the second arm 130 may be mounted upon the rivet 150 such that hole 133 of the second arm is received upon, and sized to be pivotal with respect to, the first post 151 of the rivet. The first arm 120 may then be mounted upon the rivet 150 such that hole 124 of the arm is received upon its second post 152 . The side of the arm may abut the shoulder 151 S formed by the side of the post 151 and the post 152 . The second end 142 of torsion spring 140 may loop about the side of the elongated flat plate of the first arm, as seen for example in FIG. 4 . The post 152 may then be bucked to fixedly secure the first arm 120 to the shoulder 1515 , so that there will be no relative motion therebetween. Instead of relying upon the bucked post 152 to fixedly secure the first arm 120 to the rivet 150 , the post 152 may have a flat side 152 D, as seen in FIG. 12A , to form a D-shaped profile, which may be mated to a correspondingly keyed opening 124 D ( FIG. 9A ) that may be used instead of the plain round hole.
[0119] Therefore, as seen in FIG. 2A , when the bracket 110 of catch assembly 100 is properly mounted to the sash (i.e., with the bracket generally oriented in the vertical direction and using backing plate(s) 110 A/ 110 B that are shown in FIG. 2B to accommodate different sash/frame profiles), the first arm 120 may normally pivot downwardly (clockwise in the view) about the bracket due to gravity, until reaching the stop 113 A of the bracket. At the same time, torsional biasing provided by torsion spring 140 may cause the second arm 130 to pivot upwardly (counterclockwise in the view), in opposition of the force of gravity, until the side of the second arm contacts the stop 125 on the first arm 120 . Without any forces acting upon the catch assembly 100 , it may normally occupy this retracted position that is illustrated within FIG. 2A .
[0120] An exemplary release assembly 200 is shown separately in FIG. 4A , but in its simplest form it may instead consist of a hook element configured to be pivotally received in the master window frame, where a hook portion of the element may be configured to engage the shaped opening 135 in the second end of the second arm 130 , and be disengaged therefrom through its pivotal motion within the master window frame. This pivotal movement of this hook element that enables engagement within the opening and disengagement therefrom of its hook portion, especially using the notch 135 N in the second arm 130 , may be seen in viewing FIGS. 4B and 5B . This simple version of the hook element may be a slightly modified version of the combination of the hook member 210 and base member 230 that are discussed hereinafter.
[0121] For ease of manufacturing and/or other reasons, this simplified hook element may be replaced by the combination of the separate hook member 210 that is shown within FIGS. 15-15C and the separate graspable switch member 220 that is shown within FIGS. 14-14C .
[0122] The hook member may take many different shapes, however, the exemplary hook member 210 shown in FIG. 15 may be a narrow, thin-shaped material that is formed to have a hook portion 212 extending from one end of its shank 211 . The other end of the shank 211 may have an eye formed thereat, or it may instead be formed with a return flange 214 that extends from a cross-member 213 to create a clasp portion 210 C. The clasp portion 210 C may be fixedly secured to a corresponding retaining member 222 formed within a recess 220 R of the switch member 220 , so that the angled hook portion 210 C of hook 210 protrudes outwardly therefrom (see FIG. 2H ). The length of the shank 211 and its shape may be particularly formed so as to permit the hook portion 212 to be somewhat flexible with respect to the clasp portion 210 C, after it has been secured to the retaining member 222 of the switch member 220 . The clasp portion 210 C of hook member 210 may be fixedly secured within the corresponding recess 220 R of the switch member 220 using a friction fit, or using adhesive, or mechanical fasteners, or any suitable fastening means or combination thereof.
[0123] The shaft 221 of the switch member 220 may be formed to be pivotally received within a corresponding opening in the window master frame, and such an opening may be added to a window that is already installed and in service in a dwelling. However, to more easily accommodate installation of the release assembly 200 within the master frame of a newly manufactured window, and to further accommodate additional features of the opening control device of the present invention, the switch member 220 may instead be formed to be pivotally received within a base member 230 , which is illustrated within FIGS. 13-13C .
[0124] The base member 230 may have a correspondingly shaped shaft 231 that extends from a flange 232 . The flange 232 may have a pair of holes 233 A and 233 B formed therein to receive fasteners for mounting of the base member to the master window frame 21 , as seen in FIG. 2C , FIG. 2D shows the shaft 231 of the base member 230 installed within, and protruding from, the opening in the master window frame.
[0125] The shaft 221 of the switch member 220 may have a stop 223 protruding therefrom ( FIG. 14 ), which may serve to limit pivotal travel of the switch member to 90 degrees of travel within the shaft 231 of the base member 230 ( FIGS. 4A and 5A ). The travel of the switch member 220 may be so limited by a pair of corresponding stops formed within the hollow of the shaft 231 of the base member 230 .
[0126] As an additional safety precaution, to better prevent a mischievous child from rotating the switch member 220 to disengage the opening control device to open the window fully, the device of the current invention may furthermore include a safety button 240 , which is illustrated within FIG. 16-16C , and which may be biased by the helical spring 250 that is shown within FIGS. 17-17C . The safety button 240 may have a cylindrical head portion 240 H, from which may extend two pairs of legs—a first pair of legs, 241 A and 241 B, and a second pair of legs, 242 A and 242 B. The safety button 240 may also have a post 243 protruding away from the bottom of the head portion 24011 , upon which may be received the first end 251 of the helical spring 250 .
[0127] This combination of helical spring 250 and safety button 240 may be received within the opening 224 in the shaft of the switch member 220 , such that the pairs of legs are slidably received within corresponding elongated recesses therein, which may serve to prevent rotation of the safety button with respect to the switch member. The second pairs of legs, 242 A and 242 B, as seen in FIG. 16 , which may be longer than the first pair of legs, may have respective outwardly extending flanges 242 A F and 242 B F .
[0128] Although it may be understood by one skilled in the art that other features may be used to similarly accomplish functional mating of the safety button 240 , the switch member 220 , and the base member 230 , the second pair of legs 242 A and 242 B of the safety button may herein be received through correspondingly shaped openings 225 A and 225 B in the switch member ( FIGS. 7 and 14A ), to secure the safety button to the switch member. The second pair of legs will need to be elastically deflected inwardly in order for the outwardly extending flanges 242 A F and 242 B F of the legs to be received through the opening 224 in the shaft 221 of the switch member 220 . Once having passed therethrough, the legs would naturally deflect back to their undeformed position, as seen in FIG. 16A , and may thereby secure the safety button 240 with respect to the switch member 220 , as a portion of the outwardly extending flanges 242 A F and 242 B F of the legs would now overhang beyond the diametrical periphery of the shaft 221 (see FIGS. 14C and 16B ). The helical spring 250 retained between the safety button 240 and the base member 230 may serve to normally bias the button to have a portion protrude outwardly beyond the graspable handle portion 226 of the switch member 220 ( FIG. 4A ).
[0129] This subassembly—the switch member 220 , the safety button 240 , and the spring 250 —may be coupled with the base member 230 , with the shaft 221 of the switch member being received within the opening 234 of the shaft 231 of the base member 230 . The second pair of legs 242 A and 242 B may again need to be elastically deflected inwardly in order for the outwardly extending flanges 242 A F and 242 B F thereon that protrude beyond the diametrical periphery of the shaft 221 , to be received through the opening 234 in the shaft 231 of the base member 230 . The outwardly extending flanges 242 A F and 242 B F may also be aligned to be received through the correspondingly shaped openings 235 A and 235 B in the base member (see FIG. 7 , and FIGS. 13A , 14 A, and 16 B). Once having passed therethrough, the second pair of legs would again naturally deflect outwardly back to their undeformed position and would extend slightly beyond the periphery of the opening 234 ( FIG. 13A ), to thereby secure the subassembly of the switch member 220 , spring 250 , and safety button 240 with respect to the base member 230 . In addition, with the formation of the shaped openings 235 A and 235 B in the base member, the lateral extent of which may protrude in the axial direction to be slightly beyond the point where the outwardly extending flanges 242 A F and 242 B F overhang the periphery of the opening 234 of the shaft 231 , pivoting of the switch member relative to the base member may thereby be inhibited. This functions as a safety—a means of preventing inadvertent actuation of the release member of opening control device, by some person not familiar with the device (i.e., a child-proof safety). However, by depressing the safety button 240 to overcome the biasing by spring 250 , the portion of the outwardly extending flanges 242 A F and 242 B F of the second pair of legs that were still nested within the lateral extent of the openings 235 A and 235 B in the base member, may now protrude beyond its extent, and thus the switch member is then free to pivot until such pivoting is limited by the aforementioned stops, being after roughly 90 degrees of rotation (see FIGS. 2F , 2 G, and 2 H).
[0130] Another additional feature that may be incorporated into release assembly 200 may be the further provision that the helical compression spring 250 that is used to normally bias the safety button 240 outwardly from the opening 224 in the switch member 220 , may also be formed to have its first and second ends 251 and 252 be usable for providing torsional biasing of the switch member 220 relative to the base member 230 . The radial over-center portion 253 of spring 250 at its first end 251 ( FIG. 17C ) may be received in the groove 243 G in the post 243 of the head 240 H of the safety button 240 ( FIG. 16 ). Also, the outwardly extending hook portion 254 at the second end 252 of the spring 250 may similarly be restrained within a portion of the base member 230 . Therefore, when the safety button 240 of the release assembly 200 is depressed and the switch member 220 is manually pivoted 90 degrees to thereby also pivot hook portion 212 ( FIG. 5A ), after the user releases his/her grip from the switch member, the dual-biasing spring 250 may then serve to bias the switch member to counter-rotate the 90 degrees, and as well as serve to bias the safety button to translate outwardly to once again be positioned as seen in FIG. 4A .
[0131] Operation of the opening control device of the present invention may thus be understood by initially viewing FIG. 2 . With the catch assembly 100 shown in its normally retracted position on window sash 11 , as described hereinabove, the opened window sash may then be closed, which may serve to bring the catch assembly on the sash into proximity with the release assembly 200 on the master window frame, and cause engagement between the hook portion 212 of the hook member 210 and the shaped opening 135 of the second arm 130 . This is illustrated within FIG. 3 , in which the sash and the master window frame are not shown, to better illustrate the engagement therebetween, which occurs automatically through the mere closing of the window. The flexibility of the shank 211 of the hook 210 may serve to aid in the engagement therebetween, as the approaching side of the second arm 130 may cause the angled hook portion 212 to deflect out of its way, and then it may deflect back, as the opening 135 in the arm reaches the hook portion 212 . The generally rectangular shape of the opening 135 in the second arm 130 may also serve to better accommodate capture of the hook portion 212 of the shank 211 of hook member 210 , which will be protruding substantially orthogonally from the master window frame 21 .
[0132] When the user opens the window, the bracket 110 on the sash moves away from the release assembly 200 on the master window frame. The engagement between the hook portion 212 of the hook member 210 and the shaped opening 135 of the second arm 130 serves to overcome the torsional biasing of the spring 140 , so that increasing distance between the sash 11 and master frame 21 ( FIG. 1 ) results in the extension of the first and second arms 120 and 130 , as seen in FIG. 4 . (Note, recess 126 on first arm 120 and small tab 134 on second arm 130 may prevent over-travel therebetween). The length of the first and second arms 120 and 130 may be sized so that this limited travel of the sash 11 is small enough to prevent a child from accidentally falling through the opening, and may be roughly four inches.
[0133] As seen in FIGS. 1 and 2 , the opening control device may be positioned on an upper part of the sash and master window frame to make it more difficult for a small child to reach the release assembly. When an adult desires to open the window beyond the travel limited position of FIG. 1 , the safety button 240 of the release assembly 200 , as seen in FIG. 4A , may be depressed and the switch member 220 may be rotated, so that it appears as shown in FIG. 5A . This results in the hook portion 212 of hook member 210 moving from its initial engaged position, as seen in FIG. 4B , to the disengage position, as seen in FIG. 5B . Note that the notch 135 N in the opening 135 of the second arm 130 may be shaped as shown in FIG. 10A , so that with the second arm extended as seen in FIG. 4 , rotation of the hook member 210 would not tend to cause its hook portion 212 to jam against the side of second arm, and may freely exit from the opening 135 through the notch, as shown in FIG. 5B . The hook member may thus be freely rotated from its first hooked position, wherein the hook 212 of the release assembly is connected with the second arm of the catch assembly, to its second unhooked or position. Once the hook 210 is disengaged, retraction of the arms may occur, where the force of gravity may cause the first and second arms 120 and 130 to drop vertically, and the second arm may also pivot with respect to the first arm, due to biasing by spring 140 , and both may move away from the release assembly 200 , as seen in FIG. 6 , until reaching the retracted position seen in FIG. 2 . The sash may now be fully opened.
[0134] An alternate embodiment of the catch assembly 100 and release assembly 200 may be catch assembly 101 and release assembly 201 that is formed using component parts being generally the same as those in FIG. 7 , but with some minor adjustments have been made thereto, and with the modified parts being shown within the exploded view of FIG. 19 .
[0135] The torsion spring 140 of FIG. 7 and FIGS. 11-11C may be replaced by torsion spring 340 , which is shown in detail within FIGS. 34-37 . Torsion spring 340 may include a small number of helical windings 340 W that may terminate in a first leg 341 and a second leg 342 . At the end of the first leg 341 being distal from the windings may be formed a hook portion 341 H, and at the end of the second leg 342 may be formed a hook portion 342 H. The first and second legs 341 and 342 may be used to bias the second arm 130 with respect to the first arm 120 . However, with this arrangement, the bias that is applied by torsion spring 340 is applied directly to arms 120 and 130 , whereas, for spring 140 , the bias is applied through the rivet 150 and its connection to the first arm 120 . As seen in FIG. 20 , for catch assembly 101 and release assembly 201 , the hook portion 341 H of the first leg 341 of torsion spring 340 may wrap around the first arm 120 , in proximity to its stop 125 , while the hook portion 342 H of the second leg 342 may wrap around the second arm 130 . When the first arm 120 and second arm 130 are extended by opening of the sash, the torsion spring is elastically deformed, and as seen in FIG. 21 , the first and second legs 341 and 342 of the spring 340 being so deformed apply a biasing force to the arms 120 and 130 . Here again, once the release assembly 201 no longer has its hook secured within the opening 135 of the second arm, the spring 340 will bias the two arms to rotate toward each other until the side of the second arm contacts stop 125 , as seen in FIG. 20 .
[0136] For release assembly 201 , the hook member used therein may take a slightly different shape, and a hook member 410 , which is shown in detail within FIGS. 30-33 , may be used instead of hook 210 . Hook 410 may be formed similar to hook 210 , but may have a hook portion 410 C that is more rectangular in shape, and its return flange 414 may have a bent end flange 415 thereon, which may serve to more positively retain the hook in engagement with the switch member. The release assembly 201 may also use a base member 430 and a switch member 420 , with the features of each being shown in detail within FIGS. 22-25 , and FIGS. 26-29 , respectively.
[0137] The examples and descriptions provided merely illustrate a preferred embodiment of the present invention. Those skilled in the art and having the benefit of the present disclosure will appreciate that further embodiments may be implemented with various changes within the scope of the present invention. Other modifications, substitutions, omissions and changes may be made in the design, size, materials used or proportions, operating conditions, assembly sequence, or arrangement or positioning of elements and members of the preferred embodiment without departing from the spirit of this invention.
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A device may limit opening of a sash hingedly coupled to a master frame, and includes: a bracket attached to the sash; a first arm having a first end pivotally coupled to the bracket; a second arm having a first end pivotally coupled to the first arm's second end; means for biasing the second arm into a retracted position; and a release assembly. The release assembly is secured to the master frame and includes a hook pivotable between a first position and a second position, which, in the first position, may be releasably received in an opening in the second end of the second arm when the second arm is in the retracted position, as the sash is closed and received within the master window frame The second arm is disengaged from the hook, permitting full opening of the sash, when the hook is pivoted into the second position.
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BACKGROUND OF THE INVENTION
This invention relates, in general, to semiconductor memory devices and more particularly, to electrically alterable, nonvolatile floating gate memory devices.
The microprocessor based systems, as well as the related arts, have long required electrically alterable read only memory (EAROM) elements that were nonvolatile and many such devices have, to some extent, filled this need. However, as the computer arts have become more complex in nature and have required high speeds and greater capacity there now exists the need for a high density memory device that may be easily programmed or "written" and, as the occasion arises, to reprogram ("erase" and "rewrite") the device in the field. To this end, devices are presently available to the design engineers that exhibit nonvolatile characteristics but, as will be discussed, they have inherent shortcomings that are overcome by the subject invention.
One such device resides in the family of Floating Gate Avalanche Metal Oxide Semiconductor (FAMOS) devices. The advantage of this type of device resides in the fact that it is independent of any outside current to maintain the stored information in the event power is lost or interrupted. Since these devices are independent of any outside power there is also no need to refresh the device which feature results in a significant savings in power.
The floating gate family of devices usually has source and drain regions of a given conductivity type, formed in a substrate of the opposite conductivity type, at the surface thereof. Between the source and drain regions, and on the surface of the substrate, a gate structure is constructed by first applying a thin insulating layer followed by a conductive layer (the floating gate) which is usually followed by a second insulating layer in order to completely surround the floating gate and insulate it from the remainder of the device. A second conductive layer (usually referred to as the control gate) is formed over the second insulating layer (in the region of the floating gate) to complete the gate structure. Such devices are exemplified in U.S. Pat. No. 3,500,142 which issued to D. Khang on Mar. 10, 1970 and U.S. Pat. No. 3,660,819 which issued to D. Frohman-Bentchkowsky on May 2, 1972.
The major drawback of these prior art devices resides in the fact that high fields are required to produce the necessary avalanche breakdown in order for charge to be placed on the floating gate. Further, to erase charge placed on the floating gate, the entire device must be provided with a transparent window so that the chip may be flooded with energy in the ultra violet or x-ray portion of the spectrum. Thus, it is extremely difficult to erase a single "word" without erasing all the charge on the device then requiring that the entire chip be completely reprogrammed. Further, the erasing step required an extremely long period of exposure time, of the order of about 30 to 45 minutes, with the device or chip removed from the equipment.
In recent years, the art has progressed to the point where nonvolatile, floating gate read only memory devices have been produced which are electrically alterable. One such memory cell has been described in detail in an article entitled "16-K EE-PROM Relies on Tunneling for Byte-Erasable Program Storage" by W. S. Johnson, et al., ELECTRONICS, Feb. 28, 1980, pp. 113-117. In this article, the authors describe a "Floating-Gate Tunnel Oxide" structure wherein a cell using a polycrystalline silicon (polysilicon) floating gate structure has its gate member charged with electrons (or holes) through a thin oxide layer positioned between the floating gate and the substrate by means of the Fowler-Nordheim tunneling mechanism. An elevation view of a typical device is described, and shown in FIG. 1 of the article, wherein the floating gate member represents the first polysilicon level. By using this type of structure (a structure wherein the first level polysilicon represents the floating gate since it is closest to the substrate, and is covered by a second polysilicon level) an excessively high floating gate-to-substrate capacitance is produced. However, acceptably low "write" and "erase" operations can only be achieved when most of the applied voltage appears across the tunnel region which requires that the floating gate-to-control gate (second polysilicon level) capacitance be larger than the floating gate-to-substrate capacitance. Further, to achieve the required distribution of capacitance to produce the acceptable "write" and "erase" characteristics, the prior art has resorted to extending both the first and second polysilicon levels over the adjacent field oxide to obtain the additional capacitance. The net result is an undesirably large cell.
In one recent application, filed in the U.S. Patent and Trademark Office on Oct. 18, 1982, Ser. No. 437,271 entitled "AN ELECTRICALLY ALTERABLE, NONVOLATILE FLOATING GATE MEMORY DEVICE," and assigned to the same assignee as the subject application, and now U.S. Pat. No. 4,558,339, there is described a novel configuration of a floating gate memory device wherein the floating gate is a second level polysilicon rather than the traditional first level polysilicon. This is done in order that the second level polysilicon floating gate be provided with a shield. The first level polysilicon is provided with an aperture and the second level floating gate is made to extend through the aperture so that only a relatively small area of the second level floating gate is coupled to the substrate. By providing such a structure it was found that the otherwise high floating gate-to-substrate capacitance was reduced. These ends are accomplished by providing a dual section portion, extending from the source region, to create an auxiliary channel region for "erasing" and "writing" into the resultant cell.
In another recent application entitled "AN ELECTRICALLY ALTERABLE, NONVOLATILE FLOATING GATE MEMORY DEVICE," filed by the subject inventors in the U.S. Patent and Trademark Office on Dec. 10, 1982, Ser. No. 448,690, and assigned to the same assignee as the subject application, and now U.S. Pat. No. 4,513,397 we describe an electrically alterable, nonvolatile floating gate memory device wherein the floating gate portion is the second level polysilicon. In our co-pending application, we are able to reduce the area previously occupied by each device by coupling the floating gate to the substrate at the portion of the channel region that conduction takes place. The coupling takes place through a self-aligned, rectangularly shaped aperture in the first level polysilicon layer. The aperture has its short sides parallel to the sides of the first level polysilicon layer, but spaced therefrom to allow for mask alignment tolerances. The optimum dimension of the aperture was found to be about 5 microns long and about 2 microns wide with a 2 micron tolerance between each end of the aperture and the adjacent side of the first level polysilicon. This then dictated that the side-to-side dimension of the first and third level polysilicon layers be about 9-10 microns while the aperture is about 5 microns long. In practice, it was found that each device required a minimum active area of about 210 square micrometers (micron) to provide reliable devices consistent with good manufacturing techniques in order to produce consistently high yields. By removing the need to maintain certain mask tolerances, we find that the active area can be reduced by about 30%, thus making space available for additional devices in the same chip area.
SUMMARY OF THE INVENTION
In the subject application, as in our prior, co-pending application, the polysilicon floating gate is a second level polysilicon layer rather than the prior art first level in order to provide a structure wherein the second level polysilicon floating gate is shielded from the substrate by the first level polysilicon (the program or control gate). The first level polysilicon is now a discontinuous layer and is provided with a slot so that only a small portion of the second level polysilicon (floating gate) extends through the slot whereby only a relatively small area of the second level polysilicon is coupled to the substrate.
In order to conserve chip area and thus increase chip density (the number of devices in a given area), the subject application teaches the elimination of certain portions of the first and second level polysilicon layers and how to provide electrical continuity by means of buried contacts.
BRIEF DESCRIPTION OF THE DRAWING
FIG. 1 is a plan view of an electrically alterable, nonvolatile floating gate memory device made in accordance with the teachings of our invention;
FIG. 2 is a cross-sectional, elevation view of our novel memory device taken along line 2--2 of FIG. 1;
FIG. 3 is a cross-sectional, elevation view of our novel memory device taken along line 3--3 of FIG. 1; and
FIG. 4 is a schematic representation of an array of devices of our invention.
DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENT
Referring now to FIGS. 1, 2 and 3, there is shown a single device 10 formed in a P-doped substrate 12 with oppositely doped source and drain regions 14 and 16, respectively, separated by channel region 18. In order to simplify both the drawing and the associated explanation, it will be understood by those skilled in the art that the device 10 could also be formed in a P-doped well that had been previously formed in an N-doped substrate. The use of substrates and oppositely doped wells provides certain isolation that may be desirable in certain circumstances.
At the surface of the P-doped region are field oxide regions 22 which define the limits of each active region for device 10, it being understood that the active region or area consists of source line 14, drain line 16 and channel region 18. Above the channel region 18, and oriented in a direction generally parallel thereto, is a first level discontinuous polysilicon layer 24, representing a word line or control gate. One portion of layer 24 starts over source region 14 and terminates over channel region 18 to form one side of slot 19 while the other portion starts over drain region 16 and terminates over channel region 18 to form the other side of slot 19. Both portions are separated and insulated from the surface of substrate 12 by means of insulator layer 26 which may, for example, have a thickness of about 500 Angstroms. A second level polysilicon layer 30 (the floating gate) is positioned above and generally parallel to both portions of first polysilicon layer 24 and is shown having a portion thereof extending through the slot 19 formed between the ends of layer 24. Layer 30 is insulated from channel region 18 by means of insulating oxide layer 20 which is thinner than insulating layer 26. The need for the insulator 20 to be thinner than insulating layer 26 will be discussed later. The area of coupling of the second level polysilicon layer 30 to the substrate which, together with the slot 19 formed between the ends of layer 24, is referred to as the write window. The remainder of second level polysilicon layer 30 (floating gate) is insulated from the first level polysilicon layer 24 (word line/control gate) by means of insulating layer 28 which may, for example, have a thickness of about 400 Angstroms.
Finally, a third level polysilicon layer 34 is formed over floating gate 30 that is electrically connected to first level polysilicon layer 24 by means of buried contacts 36 and 38. The third level polysilicon layer 34 is insulated from second level polysilicon layer 30 (floating gate) by an insulating layer 32 which may, for example, have a thickness of about 300 Angstroms.
Referring again to FIGS. 1, 2 and 3 it should now be observed that, to obtain optimum tunneling it is important to maintain as much of the applied field as possible between the floating gate 30 and the substrate or P well 12. Accordingly, the floating gate (30)-to-channel (P well 12) capacitance must be reduced while the word line/control gate (24-34)-to-floating gate (30) capacitance must be increased to as large a value as possible. However, the floating gate (30)-to-channel (P well 12) capacitance is governed by the thickness of the oxide layer 20 under the slot 19. This oxide thickness should not be increased much above a thickness of about 120 Angstroms as this would tend to decrease current density which would then require higher fields or longer times to charge the device. Thus, this thickness represents an upper limit and will be determined by tunneling requirements. Since, therefore, the tunneling oxide cannot be made thicker, we have chosen to make the interpolysilicon (polysilicon-to-polysilicon) capacitance much larger than the polysilicon-to-substrate capacitance by providing a minimum area tunneling section in combination with the large polysilicon word line/control gate (24-34)-to-floating gate (30) area.
As previously stated, the improvement of the subject invention over our prior application resides in a significant reduction in the active area occupied by each device. For example, in practice it was found that in order to manufacture devices with more than just a minimum yield, certain mask tolerances must be maintained. The width of the first, second and third level polysilicon layers in our prior application (corresponding here to layers 24, 30 and 34) are all aligned and are about 10 microns wide while the length of the aperture (corresponding to slot 19) is about 5-6 microns. To insure that there is electrical continuity all along layer 20, mask tolerances dictated that an additional 2 microns be added to the width of the first polysilicon layer at each end of aperature formed therein, resulting in an increase of about 4 microns.
In the subject application, we remove the need to include the masking tolerance and thus save valuable space. In our prior application, the active area occupied by each device was found to be about 14 microns by about 15 microns (210 square microns). By reducing the width of the word line 24 of the subject application by 4 microns to about 10 microns, we now have an active area of about 10 microns by about 15 microns (150 square microns) thus effecting almost a 30% reduction in the active area. Thus, by utilizing a slot 19 configuration as shown in FIGS. 1 and 2, we eliminate the aperture of our prior application as well as the need for mask tolerance. However, to maintain the required electrical continuity between word lines 24 of adjacent devices, the buried contacts 36 and 38 (FIG. 1) are formed between layers 24 and 34.
The following table shows the nominal potentials applied to the various elements of our device in order to perform the "erase", "erase", (inhibit erase), "write", "write" (inhibit write) and "read" functions of an electrically alterable memory device. In the table, the various potentials shown in each of the columns are applied to the elements in the columns entitled "ELEMENT".
______________________________________ELE- MENT READ WRITE ##STR1## ERASE ##STR2##______________________________________Source 0 V 0 V 20 V 20 V 20 V(14)Drain 5 V 0 V 20 V 20 V 20 V(16)P well 0 V 0 V 0 V 20 V 0 V(12)Word 5 V 20 V 0 or 20 V 0 V 0 or 20 VLines(24, 34)______________________________________
Thus, as shown in the above table, the device is initially erased by placing a 20 volt signal on drain 16, source 14 and P well 12. This initial "erase" cycle places a positive charge on floating gate 30 which puts the channel region in a low threshold (high conduction) state. However, there will be no electron flow through the channel region unless and until the proper "read" voltages, as indicated in the above table, are applied. This provides a convenient method for checking the devices to determine that all the elements in the array are, in fact, erased. To be certain that the non-selected cells are not erased (placed in a high conduction/low threshold state), an erase (erase inhibit) signal of zero volts is applied to P well 12 and a signal of about 20 volts is applied to all sources 14 and drains 16.
To "write", a 20 volt signal is placed on word lines 24, 34 while source 14, drain 16 and P well 12 are maintained at ground potential (zero volts). This has the effect of placing a negative charge on floating gate 30 which puts the channel region in a high threshold (low conduction state). Under these conditions, the negative charge on floating gate 30 will prevent the channel region from being inverted and no conduction can take place between source 14 and drain 16 during the read cycle. To be certain that only the selected cell is "written", a "write" (write inhibit) signal of about 20 volts is applied to those sources 14 and drains 16 of those devices that it is desired to remain unwritten. To "read" the device, that is, to determine whether a high or a low threshold state has been written into the given cell, a 5 volt signal is placed on drain 16 and word lines 24, 34 while source 14 and P well 12 are maintained at ground potential. The indication of conduction under these circumstances will thus signify the presence of a low threshold state (erased) device.
While we have described the operation of a single device, it should be obvious to those skilled in the art that a plurality of these devices may be assembled in rows and columns to form an array. Structurally, each active device of FIGS. 1, 2 and 3 would have each portion 24 extend over a field oxide region 22 to an adjacent drain or source region of the next adjacent active device in the same row while layer 34, together with buried contact means 36 and 38, would provide the necessary electrical continuity for all devices in the row. One such array is illustrated in FIG. 4 where we have shown how our novel device may be arranged in a single well. In this FIGURE, the lines labelled S1 and D1 denote the common source and drain lines (14 and 16) shared by all the devices in the first column, while S2-D2 through Sy-Dy denote the remaining columns and their respective shared sources and drains. W1, W2-Wx indicate the common word lines (24, 34) in each row. Thus, to form a 1024-bit array, one would form eight columns (S1-D1 through S8-D8) with one hundred twenty-eight devices connected to word lines W1-W128. If, for example, one were desirous of assembling a 16 thousand (2 K×8) bit array, one would first form 16 P wells each of which would have 8 of these devices in a row and 128 rows high. Thus, each P well would have 1024 of these devices and the array would contain 16,384 cells. Each of the 128 devices in a column in a given P well should share the same source and drain lines 14 and 16 while each of the devices in the same horizontal row of all wells would share common word lines 24, 34. However, each device would have its own floating gate member 30. Accordingly, by appropriately biasing the source and drain lines 14 and 16 as well as P wells 12 as shown in the above table, one could very easily "write" or "read" any one of the 16 thousand devices present and "erase" all of the devices in a given row in a given well.
While we have chosen to describe our device in terms of multiple layers of polysilicon (polysilicon silicon), we do not wish to be so limited. It should now be obvious to those skilled in the art that various other conductive layers such as refractory metals, refractory metal silicides, etc., or any combination thereof, may be used in place of polysilicon layers 24, 30 and 34.
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A floating gate structure wherein the floating gate is a second level polysilicon layer that is substantially shielded from the substrate by a segmented, discontinuous first level word line. Coupling of the floating gate to the substrate for "writing" is accomplished by extending the floating gate between word line segments while electrical continuity of the word line is maintained by buried contacts which make electrical contact to a continuous third level polysilicon layer.
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This is a division of application Ser. No. 07/381,289, filed Jul. 18, 1989, now abandoned.
BACKGROUND OF THE INVENTION
1. Field of Invention
This invention relates to a DRAM (Dynamic Random Access Memory) cell of highly integrated semiconductor storage device, and to a method for manufacturing the same, and more particularly to a DRAM cell comprising a SDT (Side-wall Doped Trench capacitor) cell having a trench capacitor cell structure with a high concentration of selectively doped region on a silicon substrate, and a SDTSAC (Side-wall Doped Trench Capacitor using a Self-Aligned Contact) cell in the SDT cell structure for increasing the capacitance of the trench capacitor, and a method for manufacturing such cells.
2. Related Application
Photoresist etch back technology is fully described in a copending patent application, concurrently filed herewith, entitled: A Method For Manufacturing A Trench Capacitor Using A Photoresist Etch Back Process, by Yong Hyeock Yoon and Cheol Kyu Bok, inventors, assigned to Hyundai Electronics Industries Co., LTD., having U.S. Ser. No. 07/381,288, filed Jul. 18, 1989, now U.S. Pat. No. 4,994,409 granted Feb. 19, 1991, said application being expressly incorporated herein by reference as if fully set forth hereat.
INFORMATION DISCLOSURE STATEMENT
In the prior art, since the capacitor region in DRAM devices has been formed in a planar cell structure, the size of the cell increased so that it was not possible to manufacture an effective DRAM. Accordingly, in order to solve this problem, the trench capacitor or laminated capacitor cell structures have been developed in which the structure of the capacitor has three dimensions, such as the following capacitors: CCC structure (Corrugated-trench Capacitor Cell), BSE structure (Buried Storage Electrode Trench) or SPT structure (Substrate Plate Trench Capacitor Cell).
However, first, the cell size in the CCC structure is too big and the concentration of the P well is too high so that the body effect in electrical property of N-MOSFET becomes large.
Second, the BSE structure, which overcomes the disadvantage of the CCC structure set forth above, utilizes a principle of inside charge storage in which doped polysilicon functions as a storage electrode, resulting in a few advantages such as no leak current and reduction of the cell size. But this structure does not comprise C-MOSFET but rather N-MOSFET so that it consumes too much power. Further an epitaxial layer structure should be utilized and due to the buried contact structure, the process for manufacturing the cell is complex.
Third, in the SPT structure, the distance between capacitors is minimized by forming the capacitors under a field oxide film thereby reducing soft error rate caused by α particles near the P-N junction. Also, noise reduction can be obtained. This structure results in an improvement over the BSE structure. However, in this structure, when P type or N type well region is formed at an epitaxial layer on the substrate, an expensive impurity ion implantation apparatus using high voltage must be utilized instead of a high temperature diffusion process and an epitaxial substrate resulting in high manufacturing cost of the cell.
Accordingly, it is an object of the present invention to provide a DRAM cell and a method for manufacturing such. The DRAM of the present invention comprises a SDT cell structure in which charges can be stored in the trench and the effective capacitance can be increased by forming a P+diffusion region selectively on the wall of the trench, instead of using an epitaxial layer, in order to avoid the disadvantages set forth above and to reduce the size of the cell.
It is an another object of the present invention to provide a method for manufacturing a DRAM cell and a DRAM cell comprising a SDTSAC structure in which the process for connecting the bit lines and the source electrode of a transfer gate, and the drain electrode and the charge storage electrode in the trench can be implemented by a self-aligned contact process which does not require a contact mask, whereby it is possible to reduce the tolerance i.e. an effective distance required during the contact mask alignment process in the prior art so that the area of the DRAM cell comprising a SDT cell and a MOSFET can be reduced.
BRIEF SUMMARY OF THE INVENTION
The present invention relates to a dynamic random access memory, DRAM, of a SDT cell structure which comprises a P type silicon substrate on which a P well region is formed. A trench is formed through the P well region and extendS into the P type silicon substrate. The trench further includes a wall having an inner surface and an outer surface and a top. A capacitive dielectric thin film layer is formed on the inner surface of the wall of the trench Material for forming a charge storing electrode fills the trench. A field oxide layer is formed on a portion of the top of the trench and on the surface of the P well region located proximate the trench. A gate electrode line is formed on the field oxide layer. A selectively doped P+diffusion region is formed from the outer surface of the wall of the trench in a portion of the P well region and a portion of the P type silicon substrate. A N MOSFET is formed on the P well region proximate the trench with the N MOSFET having a gate electrode, a source electrode and a drain electrode, with the source electrode and the drain electrode each including a LDD region. An oxide film spacer is formed at each side of the gate electrode and the gate electrode line. A conducting layer is formed on the gate electrode, gate electrode line, drain electrode and source electrode. A first insulating layer is deposited on the conducting layer except for a portion of the top of the source electrode. A polycide layer for a bit line is formed on the first insulating layer and connected to the conducting layer on the source electrode. A second insulating layer is formed on the polycide layer for the bit line. A protective layer is formed on the second insulating layer for protecting the cell.
The present invention also relates to a method for manufacturing a DRAM of SDT cell structure which comprises forming a P well region on a P type silicon substrate. A trench is formed from the top of the P well region into a portion of the P type substrate with the trench having a wall with an inner surface and an outer surface. A selectively doped P+diffusion region is formed from the outer surface of the wall of the trench into a portion of the P well region and into a portion of the P type silicon substrate. A capacitive dielectric film layer is formed on the inner surface of the wall of the trench. The trench is filled with material for a charge storing electrode, and is planarized to give the top of the trench a smooth top surface. A field oxide layer is formed by LOCOS technology on a portion of the top surface of the trench and on the P well region proximate the trench. A gate electrode is formed by a mask pattern process on a portion of the P well region opposite the field oxide layer and a gate electrode line is formed by the mask pattern process on a portion of the field oxide layer. LDD regions are formed by an ion implantation process in the P well region near both sides of the gate electrode. An oxide film spacer is formed at each side of the gate electrode and at each side of the gate electrode line. A source electrode and a drain electrode are formed in the P well region by the ion implantation process such that a portion of the source and a portion of the drain electrode are located under the gate electrode. A conducting layer is formed on the entire surface except for a portion of the field oxide layer and the oxide film spacers formed at each side of the gate electrode and the gate electrode line, thereby connecting the drain electrode and the charge storing electrode. A first insulating layer is formed on the entire surface after the drain electrode and the source electrode are connected. A portion of the first insulating layer is removed by the mask patterning process, from the conducting layer which is formed over a portion of the source electrode. A polycide layer for a bit line is formed on the first insulating layer and the conducting layer, where a portion of the first insulating layer has been removed, thereby connecting the source electrode to the polycide layer. A second insulating layer and a protective layer on the polycide layer for the bit line are sequentially formed.
The invention also relates to a DRAM of a SDTSAC cell structure which comprises a P type silicon substrate on which a P well region is formed with a trench formed through the P well region and extending into the P type silicon substrate with the trench further including a wall having an inner surface and an outer surface and a top. A capacitive dielectric thin film layer is formed on the inner surface of the wall of the trench. Material for forming a charge storing electrode fills the trench. A field oxide layer is formed on a portion of the top of the trench and on a surface of the P well region located proximate the trench. A gate electrode line is formed on the field oxide layer. A selectively doped P+diffusion region is formed from the outer surface of the wall of the trench in a portion of the P well region and a portion of the P type silicon substrate. A N MOSFET is formed on the P well region proximate the trench with the N MOSFET having a gate electrode and a source electrode and a drain electrode, with the source electrode and the drain electrode each including a LDD region An oxide film spacer is formed at each side of the gate electrode and the gate electrode line. An insulating layer is formed on the gate electrode and gate electrode line. A conducting layer is formed on a portion of the top of the gate electrode, gate electrode line, drain electrode and source electrode, except for the top portion of the field oxide layer and a portion of top of the insulating layer formed on the gate electrode and the gate electrode line. A first insulating layer is deposited on the conducting layer except for a portion of the top of the conducting layer formed on the source electrode. A polycide layer for a bit line is formed on the insulating layer and is connected to the conducting layer on the source electrode. A second insulating layer is formed on the polycide layer for the bit line. A metal layer and a protective layer are the formed on the second insulating layer.
This invention further relates to a method for manufacturing a DRAM of SDTSAC cell structure which comprises forming a P well region on a P type silicon substrate and then forming a trench from the top of the P well region into a portion of the P type substrate with the trench having a wall with an inner surface and an outer surface. A doped P+diffusion region is selectively formed from the outer surface of the wall of the trench in a portion of the P well region and in a portion of the P type silicon substrate. A capacitive dielectric film layer is then formed on the inner surface of the wall of the trench and the trench is then filled with material for a charge storing electrode. The top of the trench is then planarized, resulting in a smooth top surface of the trench. A field oxide layer is then formed by LOCOS technology on a portion of the top surface of the trench and on the P well region proximate the trench. A gate electrode and a gate electrode line are formed by a mask pattern process after conducting material for the gate electrode and an insulating layer are sequentially formed on a portion of the P well region opposite the field oxide layer and on a portion of the field oxide layer. LDD regions are formed by an ion implantation process in the P well region near both sides of the gate electrode. An oxide film spacer is formed at each side of the gate electrode and at each side of the gate electrode line. A conductive layer is formed on the entire surface, except for a portion of the insulating layer formed on the gate electrode and the gate electrode line and execpt for a portion of the field oxide layer, thereby causing the charge storing electrode to be connected to the drain electrode to be formed later. The drain electrode and a source electrode are formed by diffusing the N+impurity contained in the conducting layer to the P well region with heat treatment. A first insulating layer is formed on the entire surface, and then removing a portion of the first insulating layer formed on the conducting layer on the source electrode by mask patterning process. A polycide layer for a bit line is formed on the first insulating layer and the conducting layer, where a portion of the first insulating layer has been removed, thereby connecting the source electrode to the polycide layer. A second insulating layer on the polycide layer for the bit line. A metal layer is formed on the second insulating layer and then a protective layer is formed on the second insulating layer and the metal layer.
This invention further relates to a method for manufacturing the DRAM of SDTSAC using a self-aligned contact process which comprising the steps of sequentially depositing a gate oxide film, a conducting material for gate electrode, an oxide film layer and a nitride film layer on the silicon substrate on which a P well region is formed. The conducting material for the gate electrode, the oxide film layer and the nitride film layer is then etched by a mask patterning process. A LDD region is then formed by ion implantation process after growing an oxide film at left and right sides of the conducting material for the gate electrode. Oxide film spacers are then formed by the anisotropic etching process after forming an oxide film at the left and right sides of the gate electrode. The nitride film is then removed. A conducting layer containing an impurity is deposited on the entire surface. Then a portion of the conducting layer which is deposited on the oxide film layer on the gate electrode is removed. The source electrode and the drain electrode are then formed by diffusing the impurity contained in the conducting layer into the P well region by heat treatment. A first insulating layer is formed on the entire surface, and then a portion of the first insulating layer formed on the conducting layer on the source electrode is removed. A polycide layer for bit line is then deposited on the first insulating layer and the conductive layer, where a portion of the first insulating layer has been removed, thereby connecting the source electrode to the polycide layer.
According to the DRAM cell technology of present invention, the following advantages are obtained:
First, an inside charge storage type structure for storing charges in the polysilicon filled trench, the trench walls having been coated by a capacitive oxide film, is utilized, the inside storage type structure can be applied to the DRAMs with more than 4M bit.
Second, since the present invention does not utilize the formation of a high concentration of an epitaxial layer on a silicon substrate, it is possible to fabricate CMOS which has a low power comsumption. This means that since the present invention utilizes a P well and N well region, there is no problem of diffusing the high concentration of the epitaxial layer toward the surface of the substrate, which occurs during the use of long periods of a high temperature as in prior art.
Third, in the conventional prior art SPT structure, in the formation of a N well region to protect the loss of effective capacitance as the depletion region of trench capacitor increases, a high energy ion implantation apparatus must be used. However, since the present invention does not require an underlying epitaxial layer as in the prior art devices, the formation of the well region can be implemented by heat treatment and a low energy ion implanation apparatus without using the high energy ion implantation apparatus.
Fourth, according to the present invention, instead of using a high concentration of an epitaxial layer to prevent a loss of the effective capacitance, a high concentration of impurity region is formed by selectively diffusing a high concentration of impurity along the trench wall, whereby it serves as the conventional epitaxial layer having a high concentration.
Fifth, according to the present invention, in order to maximize the effective area of the trench capacitor in the same cell size, a trench can be formed under the field oxide layer.
Sixth, a soft error immunity which is a capability to protect the cell from stored charge dissipation caused by a cosmic α particle is improved relative to an outside charge storing method of the prior art, since a capacitive dielectric film is formed on the wall of the trench and an inside charge storing method for storing charge thereon is utilized.
Seventh, the total area resulting from a manufacturing tolerance necessarily required for a mask process which is used for connecting or forming each electrode of the trench capacitor and the MOSFET can be reduced greatly using the self-aligned contact process according to the present invention.
BRIEF DESCRIPTION OF THE DRAWINGS
FIG. 1 illustrates a cross-section of a DRAM cell comprising a SDT (Side-wall Doped Trench Capacitor) cell and a MOSFET according to the first embodiment of the present invention;
FIG. 2 illustrates a schematic trench structure used for calculating the capacitance of the trench capacitor of the SDT cell structure shown in FIG. 1;
FIG. 3 illustrates a cross-section of a DRAM cell of SDTSAC cell comprising the SDT and MOSFET formed by the self-aligned contact process, according to the second embodiment of the present invention;
FIG. 4A illustrates a cross-section of the structure in which a gate electrode is formed during the self-aligned contact process;
FIG. 4B illustrates a cross-section of the structure in which a oxide film is formed on the left and the right sides of gate electrode of FIG. 4A, and the silicon wafer, with the LDD regions formed in the P well region;
FIG. 4C illustrates a cross-section of the structure in which spacers are formed at left and right sides of the gate electrode shown in FIG. 4B;
FIG. 4D illustrates a cross-section of the structure in which an IPOLY pattern is formed on the spacer positioned at the left and right sides of gate electrode; and
FIG. 4E illustrates a cross-section of structure in which a drain and a source electrode are formed by a known drive-in process after the process used to prepare the structure shown in FIG. 4D, and a LTO (Low Temperature Oxidation) film formed on the gate electrode with a pattern formed on the IPOLY layer, and,
FIGS. 5A through 5K inclusive illustrate in diagrammatic form a number of the sequential steps in manufacturing the cell.
The novel feature of the present invention may be understood from the accompanying description when taken in conjunction with the accompanying drawings.
DETAILED DESCRIPTION
FIG. 1 illustrates a cross-section of a DRAM cell comprising a SDT cell 40 and a MOSFET 31A according to the first embodiment of the present invention. The manufacturing process for such a structure includes a number of initial sequential steps as seen in FIGS. 5A-5K inclusive, and comprises: First, a P well region 15 is formed on a P type silicon substrate 1(FIG. 5A). A trench 41 (FIG. 5B) is then formed from the top 21 of the P well region 15 into the P type silicon substrate 1 by the known RIE (Reactive Ion Etching) technology. A P+diffusion region 14 is formed by diffusion into the wall 22 of the trench 41 by a selective doping method using photoresist etch back technology. Even though the process for selectively forming the P+diffusion region 14 adjacent trench wall 22 of the trench 41 using the photoresist etch back technology is not shown in the drawings, the method will be described briefly. After a dopant source, such as BSG (Boro-Silica-Glass), is deposited on the inner surface 22A of the wall 22 of trench 41 to a desired thickness (FIG. 5C), the trench 41 is filled with a photoresist and planarized (FIG. 5D). In the usual practice, the trench 41 is overfilled with the excess photoresist being removed in order to provide a planarized surface. As will be described below, after removing the photoresist and BSG layers up to the etch back end point 23 (FIG. 5E), i.e., the point the P+diffusion region 14 is formed from the outer surface 22B of wall 22 of the trench 41, the remaining photoresist is removed from the trench 41 (FIG. 5E). By heat treatment (FIG. 5F) on the dopant source, such as BSG, which remains on the inner wall 22A of the trench 41, the P+diffusion region 14 is formed (FIG. 5G). Next, a capacitive dielectric film layer 12 (FIG. 5H), for example an ONO (Oxide-Nitride-Oxide) or an oxide film layer, is deposited on the inner surface 22A of wall 22 of trench 41. The outer surface 22B of wall 22 is in contact with the P+diffusion region 14. In order to form a charge storing electrode 13, the trench 41 is filled with N type doped polysilicon 24 and the top 21 of the trench 41 is planarized by the known technology, thereby forming a trench capacitor 41A (FIG. 5I). A field oxide layer 9 (FIG. 5J), which is an insulating layer, is formed in and on a portion of the top 21 of the trench 41, i.e., only partially covers the top 21 of the trench 41 as see FIG. 1, by the known LOCOS (Local Oxidation of Silicon) technology.
After this process, in order to form a N-MOSFET 31 on the P well region 15 in the substrate 1, a gate oxide film 10 is selectively formed on the P well region 15 and then conducting material for a gate electrode 8 (FIG. 5K) is deposited entirely over gate oxide film layer 10 and field oxide layer 9. Then, by a mask patterning process for the gate electrode, the gate electrode 8 and a gate electrode line 8' are formed on the gate oxide film 10 and the field oxide film 9, respectively. LDD regions 19 are formed by the ion implantation in the P+well at the both sides of the gate electrode 8. An oxide film layer is formed at both sides of the gate electrode 8 and the gate electrode line 8', and then oxidation film spacers 20 and 20' are formed by anisotropic etching at the both sides of the gate electrode 8 and the gate electrode line 8'. A source electrode 11 and a drain electrode 11' are formed in the P well region 15 by the ion implantation process. Next, after a conductor layer, for example titanium layer, is formed on each electrode 8, 8', 11 and 11', by a mask patterning process, then a silicide layer 30 as a conducting layer for the respective electrodes, is formed on each electrode 8, 8', 11 and 11' by heat treatment. The oxide film spacer 20, 20' and the field oxide film layer 9 are not covered by the silicide layer 30, as illustrated at FIG. 1.
As result of the process forming the silicide layer 30, the charge storing electrode 13 of trench capacitor 41A and the drain electrode 11' are electrically connected each other, thereby the resistance of the gate electrode 8 and gate electrode line 8' can be reduced as well as the resistance at the junction between drain electrode 11' and the charge storing electrode 13 can be reduced. After that, a LTO oxide film layer 6 (FIG. 1), which functions as a first insulating layer, is formed and then a portion of LTO oxide film layer 6 on the silicide layer 30 formed on the source electrode 11 is removed by a contact mask patterning process. Then, by forming a polyside layer 5, for bit line, on the LTO oxide film layer 6, the silicide layer 30 on the source electrode 11 at which a portion of the LTO oxide film layer 6 is removed, is connected to the polyside layer 5. A doped oxide film layer 4 is formed as a second insulating layer and a protective layer 2 is formed thereon. Here, the protective layer 2 protects the cell from heat, shock and current etc. The structure formed by the process according to the present invention is a DRAM cell comprising SDT cell 40.
FIG. 2 schematically illustrates the trench 41 taken from the FIG. 1, in which it is assumed that the structure of the trench capacitor 41A is U shaped to facilitate calculation of capacitance. Here, the dimension, stored voltage and surface concentration of the field region of the trench 41 illustrated in this invention are as follows:
The size of trench 41=1.4 μm(micrometer)×2.1 μm
The thickness (d) of the capacitive dielectric film 12 of trench capacitor 41A, d=180 Angstrom.
The voltage of storing electrode (13)=5 Volts.
The voltage of silicon substrate (1)=-2 Volts.
The depth of trench (41), Td=5 μm
The surface concentration of field oxide layer region (9)=5 E 16 Cm -3
The surface concentration of the P+diffusion region (14)=2 E 19 Cm -3
The concentration of N+polysilicon (13)=1 E 20 Cm -3
Accordingly, the capacitance, Cs, of the SDT cell 40 is,
Cs=C1+C2+Cj (1)
Here, C1 is the capacitance of the region Wd without side-well doping.
C2 is the capacitance of the P+diffusion region 14 with side well doping.
Cj is the junction capacitance of at the drain electrode 11' of MOSFET.
However, when the voltage assumed above is applied, C1 and C2 are defined as efffective capacitance as follows:
1/C1=1/C1np+1/C1ox+1/C1d (2)
1/C2=1/C2np+1/C2ox+1/C2d (3)
Here, Cnp is a depletion capacitance at which a depletion is formed toward the N+doped polysilicon 13 when a voltage is applied, and Cox is the capacitance caused by the thickness "d" of the capacitive oxide and Cd is a depletion capacitance occurring toward the polysilicon substrate 1.
Combining the formulas, the following formula can be obtained. Here, Cj is negligible.
1/Cs=1/Cnp+1/Cox+1/C1d+1/C1d+C2d (4)
Here, ##EQU1## From the above formulas, Cnp, Cox, C1d and C2d are obtained. ##EQU2## Accordingly, from the formulas (1) to (9), the storing capacitance, Cs is,
Cs=50 fF (10)
Thus, in the case where the junction capacitance of drain electrode 11' is negligible, the storing capacitance of the SDT 40 is approximately 50 fF.
Next, the process simulation for forming the SDT 40 structure will be described. In the SDT structure 40, the method for selectively doping a high concentration of boron on the outer surface 22B of wall 22 of trench 41 is most important. In order to explain optimum conditions for the process, the SUPREM 3 and SUPPR, which are a one dimensional simulator and a two dimensional simulator, respectively, have been performed to obtain the optimized conditions, for example, the determination of selective etch back end point 23 of BSG to be formed by the photoresist etch-back technology, the deposition of BSG film and drive-in process condition.
Considering a condition of a break-down voltage at the junction, as can be seen from the cross-section of SDT 40 shown in FIG. 1, since a reverse voltage is applied between the drain electrode 11' and the P+diffusion region 14 doped with a high concentration of boron on the side wall of trench 41, there is a possibility of occurrence of a break-down voltage therebetween. In other words, the condition causing the break-down in the P well region 15 is the condition when the value of electric field E at the depletion region reaches the Ecrit value. In this case, it is assumed that the junction is a planar junction. Accordingly, the Ecrit value can be obtained from the following formula. ##EQU3##
Na is the concentration of the impurity in the P well region 15.
If the boron doped in the side wall of trench 41 is not diffused to the junction of drain electrode 11', the value of Na, which is the concentration of the P well region 15, will be 2 E 16 cm -3 from the formula (11). So, the value of Ecrit will be 4.4×10 5 V/Cm. However, in the worst case that the boron doped in the side wall is diffused to the junction, the Na will be 1 E 18 Cm -3 . Then, Ecrit will be 1.2×10 6 V/Cm.
When the Na is 2 E 16 Cm -3 and 1 E 18 Cm -3 respectively, the minimum width of the depletions should be 0.32 μm and 0.1 μm respectively in order to maintain the break-down voltage over 14 V, i.e. in order to maintain that voltage over the break-down voltage at the junction. Accordingly, when Na is 2 E 16 Cm -3 , in order to maintain over 14 V the break-down voltage at the junction of p+diffusion region 4 of the side wall of trench and the drain electrode 11', it is necessary to keep the width of depletion Wd over 0.4 μm.
Wd=0.4 μm (12)
Next, a depth Xj of the junction of drain electrode 11' will be considered.
In the case that the known silicide treatment is used for the source electrode 11 and drain electrode 11' in the MOSFET 31A, when the silicide layer 30 is formed, the silicon is reacted with titanium, thereby the area of silicon is collapsed depending upon their volume ratio. This results in a shallower junction depth which reduces the break-down voltage at the junction of the source and the drain. Since the prior art junction of the source and drain formed by arsenic 11, a formation of a graded junction with arsenic and phosphor is formed in manner that Xj, the depth of junction, is as follows:
Xj=0.35 μm (13)
On the other problems of process of P+diffusion will be considered. In checking, using the SUPREM 3 and SUPRA simulation, the optimum concentration of boron of BSG film, the drive-in condition, and distribution of boron impurity doped in the side wall of the trench, the determination of optimum value for distribution of boron impurity should satisfy two conditions. First, the concentration of boron near the interface of the side wall of trench should be 2 E 19 Cm -3 in order to increase the effective capacitance. Second, the minimum diffusion of boron into the P well region 15 should occur from the etch-back end point.
The two conditions mentioned above are determined by the concentration of BORON involved in the BSG film depositing process, and the temperature and time of drive-in treatment. As result of the simulations, the optimum conditions are as follows:
In the BSG film depositing process, the content of boron is from 1 E 21 Cm -3 to 5 E 21 Cm -3 and if the content is too low, it results in reduction of the effective capacitance. If the content is too high, the finally diffused distance will become too great after the drive-in process, thereby deteriorating the break-down property at the junction. Also, the drive-in condition for the BSG film takes about 30 minutes at 920 to 950 degrees Centigrade.
Under these conditions, the actually diffused distance "Ds" of the P+diffusion region 14 at side wall 22 of the simulated trench is approximately 0.8 to 1.1 μm in upper direction from the top of the etch-back end point of the BSG film. Here, the diffused distance in upper direction can be reduced more by using the P well region.
For example, in order to control the concentration of boron during the drive-in treatment, the optimum parameters of a sample wafer are set such that the sheet resistance is about 13 to 250 Ω/□ and the depth of junction is 0.2 to 0.3 μm.
Accordingly, from the above description, the etch-back end point value, Ep, of the BSG film required for selective doping of the side wall of the trench, by the photoresist etch-back technology during the actual process, can be determined.
The value of the etch back end point, Ep=Xj+Wd+Ds. where: Xj is the depth of junction of drain electrode 11'. Wd is the width of depletion in order to obtain the break-down over 14 Volts. Ds is the diffused distance in the side wall in upper direction from the etch-back point, which is determined depending upon the process conditions.
As obtained above, the optimum etch-back end point value, Ep is 0.35+0.4+(0.8 to 1.1), i.e. 1.5 to 1.8 μm.
It should be noted that the values set forth above have been determined on the basis of the results of experimental calculation and simulation in order to explain the gist of present invention.
The DRAM cell comprising the SDT 40 and MOSFET 31A according to the present invention is subjected to the contact mask patterning process to connect the source electrode 11 of MOSFET 31A and the electrode for bit line or to connect the drain electrode 11' to the charge storing electrode 13 of trench 41. In case of implementing the contact mask alignment process to form the gate electrode 8, to connect the source electrode 11 of MOSFET 31A and the electrode for bit line, and to connect the drain electrode 11' and the charge storing electrode 13, since a mismatch of mask alignment occurs due to a precision limit of apparatus used for the manufacturing process, the patterning process is implemented with a minimum tolerance, thereby a leak current at the connection with the gate electrode is prevented. Accordingly, the process should be implemented in a manner that the distance between the side of gate electrode 8 and contact mask has a minimum extra distance. Thus the DRAM cell manufactured according to the first embodiment of the present invention requires more space so that the structure of cell should be improved to be used for 16 or more megabit of large scale integrated memory devices.
The improved structure is shown in FIG. 3 which is the second embodiment of the present invention and it will be described in detail in reference to the FIG. 3 illustrates a cross-section of a DRAM cell of SDTSAC cell 50 structure comprising a SDT cell and a MOSFET 31B which is formed by a self-aligned contact technology according to the second embodiment of present invention. After forming the P well region 15 on the P type silicon substrate 1, a mask pattern layer is formed on the P well region 15 for forming a trench capacitor 41A and then the trench 41 is formed by the RIE etching technology and extends from the top of the P well region into a portion of the P type silicon substrate 1. As shown in FIG. 1, the P+diffusion region 14 for an external electrode is formed on the wall 22 of trench 41 by the selective side wall doping method using the photoresist etch-back technology as described above.
After the formation of the P+diffusion region, a capacitive dielectric film layer 12, for example an ONO layer or an oxide film, is deposited on inner surface 22A of wall 22 of trench 41, and at the outer surface 22B thereof, the P+diffusion region 14 is formed. In order to form the charge storing electrode 13, the trench 41 is filled with N type doped polysilicon 24 and the top 21 of the trench 41 is planarized by known technology. A field oxide layer 9 which is an insulating layer is formed by known LOCOS (Local Oxidation of Silicon) technology on a portion of the top 21 of the leveled trench 41.
Next, after the gate oxide film 10 is deposited in order to form the N type MOSFET on the P well region 15 in the silicon substrate 1, the conducting material for the gate electrode 8 and the LTO oxide film layer (17) are subsequently deposited thereon. Then, by a mask patterning process for the gate electrode, the gate electrode 8 and the gate electrode line 8' are formed respectively. On the other hand, the LDD region 19 is formed by the ion implantion at the P well region 15 near the both sides of gate electrode 8. An oxide film layer is formed at the both sides of the gate electrode 8 and the gate electrode line 8' and then the oxide film spacer 20 and 20' are formed by anisotropic etching.
Then, an IPOLY layer 7 is deposited and then a portion thereof on the gate electrode 8 and gate electrode line 8' is removed. By heat treatment, the N+impurity contained in the IPOLY layer 7 can be diffused into the P well region 15 so that the source electrode 11 and the drain electrodes 11' are formed. A LTO oxide film layer 6, which functions as a first insulating layer, is deposited and removed leaving the portion as shown in FIG. 3 and it is connected to the IPOLY layer 7 on the source electrode 11 by depositing a polycide layer 5. By depositing a oxide film layer 4, which functions as a second insulating layer, doped with BSG on the polycide layer 5 for the bit line, the insulation between metal oxide 3 and 3', and the polycide layer 5 for the bit line is obtained.
In case of continuously connecting the gate electrode 8 and the gate electrode line 8' which become a word line, a resistance is increased so that a processing speed is delayed. Accordingly, by forming the metal layer 3 and 3' for the word line on the doped oxide layer 4 and contacting the metal layer 3 and 3' to the gate electrode 8 and the gate electrode line 8' every 128th cell, the delay of speed can be avoided. The protective layer 2 is then formed so that the DRAM cell finally manufactured can be protected from heat, shock and current. The structure manufactured by the process described above is the DRAM cell of the SDTSAC cell 50 structure according to the present invention.
Referring to FIG. 3, the structure forming the gate electrode 8 on the gate oxide film 10 which is on the P well region 15, and the structure connecting the source electrode 11 and the drain electrode 11' of the MOSFET 31B to the bit line electrode and the charge storing electrode 13, is formed by the self-aligned contact method which comprises one of the main embodiments of present invention. The method will be described in detail in reference to FIGS. 4A-4E.
FIGS. 4A-4E illustrate a cross-section of a N type MOSFET structure which is located on the P well 15 near the trench capacitor. FIG. 4A shows a step in which a gate oxide film 10 and a conducting material for the gate electrode 8 are sequentially deposited. Then a LTO oxide film 17 is deposited thereon. Next, in order to protect the LTO oxide film when etching is performed and to prevent the oxide from growing in upper direction during oxidation process, a nitride film layer 16 is deposited on the LTO oxide film layer 17. Then only a portion of the structure described above is formed by mask patterning process.
FIG. 4B illustrates the structure of a partially completed MOSFET having an oxide film layer 18 deposited on left and right of the gate electrode 8 and on the P well 15 in order to prevent a current leak which may occur between the IPOLY layer 7 and the gate electrode 8 at left and right side of the gate electrode 8, and to make the depth of junction of N-impurity shallow. The LDD region 19 is formed by implanting N-impurity. Here, in order to prevent electrons from accelerating by the strong electric field occurring when an inverse conductive layer is produced at the source electrode 11 and the drain electrode 11' which are to be formed later, a low concentration of N-region, that is LDD region 19, is formed at a portion of the drain and the source, which are located near the gate electrode, thereby the strength of electric field is reduced so that it possible to prevent the electrons from accelerating.
FIG. 4C illustrates a cross-section view of a partially conpleted MOSFET in which, after the oxide film layer 18 is formed at both sides of the gate electrode 8, a oxide film spacer 20 is formed by the anisotropic etching. When heat treatment of IPOLY layer 7 to be formed later is performed, the oxide film spacer 20 prevents an N+impurity from diffusing into the LDD region 19 which is located under the gate electrode 8.
FIG. 4D illustrates the structure of a partially completed MOSFET in which, after the nitride film layer 16 on the gate electrode 8 is removed, the IPOLY layer 7 is deposited on the LTO layer 17 which is located on the gate electrode 8, and on the LDD region 19. Then, a portion of the IPOLY layer 7 on the gate electrode 8 is removed. At this moment, since there is no need to perform additional mask process when the IPOLY layer 7 is deposited, a tolerance required for the mismatch of mask alignment occurring when the mask patterning process is performed as described in opening paragraph does not have to be considered.
Referring to FIG. 3, it is assumed that the distance between the IPOLY layer 7 and the left and right side of gate electrode 8 are each X, the distance between the right side of gate electrode line 8' and the IPOLY layer 7 is X, and the width of unit cell, which is toward the word line, is Y. Then, the area which can be reduced according the present invention is 3xXxY.
FIG. 4E illustrates a cross-section of MOSFET 31B structure in which a source 11 and a drain 11' are formed by heat treatment of the IPOLY layer 7 shown in FIG. 4D by diffusing the impurity contained in the IPOLY layer 7 into P well region 15. In order to insulate the IPOY layer 7 on the gate electrode 8 from the polycide layer 5 for bit line, a LTO layer 6 is deposited and then a portion thereof is removed leaving a predetermined portion as shown. Next, a polycide layer 5 is deposited on entire surface of the MOSFET structure.
As described above, in the second embodiment of the present invention, the process for depositing the IPOLY layer 7 after formation of the gate electrode 8, the process for forming the source 11 and the drain electrode 11', and the process for depositing the polycide layer 5 for bit line after deposition of the LTO layer are performed by the self-aligned contact process.
The cell structure manufactured according to the second embodiment of the present invention can be operable as unit DRAM cell in which a MOSFET and a trench capacitor are connected in series. That is, the gate electrode, source electrode and drain electrode of the MOSFET are connected to the word line, bit line and the charge storing electrode of trench capacitor respectively, and the other terminal of the trench capacitor is connected to the P+substrate, so that the DRAM cell which may operate storage and clear operation can be obtained.
The area of RAM cell of SDTSAC cell 50 structure according to the second embodiment of the present invention can be reduced effectively in comparison with that of the DRAM cell of SDT cell structure according to the first embodiment of present invention. For example, the length, the product of 3X in bit line direction which is a minimum tolerance required for the DRAM cell of SDT cell structure during the contact mask process and the length, Y which is the width in word line direction, i.e., all area 3xXxY can be reduced.
In the DRAM cell of SDT cell 40 structure of the first embodiment of the present invention which does not employ the self-aligned mask contact process, since the tolerance of X and Y equals 0.5 μm and 2.8 μm, respectively, the area which can be reduced in the DRAM cell of SDTSAC cell 50 structure according to the second embodiment of present invention is 3XY=3×0.5 μm×2.8 μm=4.2 μm. Accordingly, in the case that the SDTSAC cell 50 structure is applied to a semiconductor storage device having more than a megabit, 4.2 μm per unit cell will be reduced so that it's effect is so great.
While the invention has been described with respect to the preferred embodiments of the process using a N MOSFET after forming a P well region 15 on a P type substrate 1, as appreciated by one skilled in the art, it should be noted that the same process can be applied to form a N well in a P type silicon substrate, on which a P MOSFET is formed, with the trench filled with a P-type doped impurity.
The forgoing description of the preferred embodiments has been presented for the purpose of illustration and description. It is not intended to limit the scope of this invention. Many modifications and variation are possible in the light of above teaching. It is intended that the scope of the invention be defined by the claims.
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A dynamic random access memory device having a SDT cell structure and a dynamic random access memory device having a SDTSAC cell structure together with methods for manufacturing each cell structure are disclosed.
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RELATED APPLICATIONS
This application is a continuation of U.S. patent application Ser. No. 13/474,361 filed May 17, 2012, titled “CRYSTAL OSCILLATOR WITH REDUCED ACCELERATION SENSITIVITY”, which is a continuation of U.S. patent application Ser. No. 12/613,336 filed Nov. 5, 2009, now U.S. Pat. No. 8,188,800, titled “CRYSTAL OSCILLATOR WITH REDUCED ACCELERATION SENSITIVITY”, which claims benefit under 35 U.S.C. §119(e) to U.S. Provisional Patent Application No. 61/112,634, filed Nov. 7, 2008, entitled “CRYSTAL OSCILLATOR WITH REDUCED ACCELERATION SENSITIVITY”, the entireties of which are hereby incorporated by reference herein and made a part of this specification.
BACKGROUND OF THE INVENTION
1. Field of the Invention
Embodiments of the invention relate generally to crystal oscillators and more specifically to crystal oscillators with reduced acceleration sensitivity.
2. Description of the Related Art
Quartz crystals are commonly used to control the frequency of electronic oscillators. Although quartz is one of the most stable materials available for fabricating a high frequency resonator, certain limitations can become apparent in precision applications. For instance, changes in the ambient temperature cause the resonant frequency to change. In addition, the natural frequency of a quartz resonator can also be affected by applied acceleration forces. In some situations, these effects on the frequency are relatively small and can go undetected (˜0.0000002% per g of applied force). However, in many applications, an oscillator must operate in an environment which subjects it to levels of vibration or shock, where the resultant frequency shifts can be significant and can limit system performance. These deleterious effects are a well known problem and a major concern of oscillator designers.
Acceleration forces applied to a crystal oscillator assembly will cause a shift in the operating frequency. If these forces are in the form of periodic or sinusoidal vibration, frequency modulation will appear as sidebands to the carrier at the vibration frequency, the amplitude of which is determined by the amount of frequency shift. When the acceleration forces are in the form of random vibration, an increase in the broadband noise floor of the oscillator will occur. Either of these conditions may result in serious degradation of system performance in a noise sensitive application. Shock pulses due to handling or other environmental events can cause a jump in the frequency which may result in circuit malfunction such as loss of lock in phase locked loop or GPS tracking applications.
There are generally two classes of methods to minimize the effects of acceleration forces on crystal resonators. The first class is known as active compensation. In active compensation, an acceleration sensor is used to detect the characteristics of applied forces and a signal is then processed and fed back to the oscillator circuit to adjust the frequency by an equal magnitude but in the opposite direction from the acceleration induced shifts. This method can be effective over certain vibration frequency ranges, but it requires a relatively complex circuit and can be very expensive to implement.
The second class is referred to as passive compensation. Passive methods do not attempt to sense the applied acceleration. Generally, in passive methods, the crystal resonator or resonators are constructed using special methods that render them somewhat insensitive to acceleration forces. Passive methods can be effective, but they generally require an involved and difficult fabrication process to produce the required crystal or composite crystal assembly.
In view of these complications, one attempt has been to cancel acceleration sensitivity including determining a dominant sensitivity axis of the resonators and then mounting the resonators with the dominant sensitivity axes in an anti-parallel arrangement. However, in aligning the resonators according to a supposedly dominant axis, such methods do not take into account the sensitivities along the other axes. As a result, the exact maximum magnitude and direction of a crystal's acceleration sensitivity characteristic is not accounted for in such methods, and it is less effective in minimizing the effects of acceleration forces.
SUMMARY OF THE INVENTION
It is more effective to account for the magnitude and direction of the total acceleration sensitivity vector by summing or taking into account sensitivity in all three axes of the resonator. The acceleration sensitivity of a quartz crystal can be characterized as a vector quantity, commonly denoted as Γ. The frequency shifts that are induced by external acceleration are therefore determined by both the magnitude and direction of the applied forces. The fractional frequency shift Δf/f under the acceleration {right arrow over (α)} is given by
Δ f f = Γ → · a → .
By measuring the components of Γ in three mutually perpendicular directions which are perpendicular to the faces of the crystal or resonator package, it is possible to calculate the exact maximum magnitude and direction of the Γ vector. Forces will have the most effect when they are imparted to the crystal in a direction that is parallel to this vector.
When two essentially identical crystals are aligned so that their vectors are in opposing directions or anti-parallel and coupled electrically in combination to the oscillator circuit, the vectors will cancel, rendering the composite resonator less sensitive to acceleration forces. Such an approach, however, has been difficult to achieve. Two crystals must be carefully matched and physically oriented so that the vectors are anti-parallel. Crystal resonators exhibit substantial variation in the direction and magnitude of the vector. The vector direction can vary as much as 60° even with resonators that have been identically manufactured. Measurements of many crystals have shown that the acceleration vector is not oriented relative to the crystallographic axes in any consistent manner even in identically designed and manufactured crystals. Based on these challenges, it has been necessary to physically manipulate the mounting orientation of the crystals to achieve the anti-parallel relationship. Vector inconsistency generally requires the use of complicated equipment such as an adjustable 3-axis gimbal mounting apparatus to individually align each crystal precisely as needed to achieve significant cancellation. Therefore, achieving vector cancellation involves a difficult and time consuming process of measuring, adjusting and mounting the crystals in an effective manner. Manufacturers have generally avoided this approach because it is so difficult and expensive. Embodiments of the present invention eliminate this burdensome process by configuring an oscillator with crystals that have been manufactured so that the direction of the Γ vector points in a consistent and predictable direction in each crystal, the direction being relative to the normal mounting plane.
Embodiments of the present crystal oscillator include a plurality of crystals mounted with the acceleration sensitivity vectors in an essentially anti-parallel relationship. This helps to cancel the effects of acceleration or vibration on the output signal of the oscillator. Due to the vector nature of this characteristic, when the crystals are so aligned, cancellation of the acceleration effects will occur. Embodiments of this oscillator use crystals which have been manufactured so that the acceleration sensitivity vector points in a consistent and predictable direction relative to the mounting surface of the resonator.
In one embodiment, crystals are selected which have the same acceleration sensitivity vector magnitudes, within a certain tolerance. Complete cancellation of the sensitivity vectors can occur if the sensitivity vectors are of the exact same magnitude. However, significant cancellation can be achieved if the magnitudes of the sensitivity vectors differ.
The crystals are preferably contained in individual crystal packages or resonators. The crystals or resonators are then mounted to an oscillator circuit which is configured to sustain periodic oscillations. In one embodiment, the crystals are coupled in pairs so that the first crystal is inverted with respect to the second crystal. This inversion can be achieved by rotating the first crystal 180° around either the x axis in the y-z plane or around the y axis in the x-z plane. Because the crystals have been manufactured so that the direction of the vector is substantially the same for all crystals, the vectors can be aligned in an essentially anti-parallel manner without the need to measure and characterize the vector direction of each crystal and then manipulate the orientation of the mounting plane of the crystals. The crystals are preferably coupled in a way that allows them to function as a single composite resonator. This allows for the construction of an acceleration and vibration resistant crystal oscillator.
One embodiment of an oscillator comprises an electronic circuit configured to initiate and sustain periodic oscillations, a plurality of crystal resonators having acceleration sensitivity vectors aligned in a consistent and predictable relationship to the normal mounting plane of the resonator, wherein said crystal resonators are coupled to the electronic circuit such that the acceleration sensitivity vectors of at least two of the crystals are in an essentially anti-parallel relationship, and wherein said crystal resonators function as a single composite resonator controlling the frequency of oscillation. The oscillator can have crystal resonators electrically coupled in parallel or the oscillator can have crystal resonators electrically coupled in series. The crystal resonators can also be mechanically mounted by rotating at least one crystal resonator 180° around either the x or y axis.
Also, the resonators can be mounted such that said resonators are disposed on opposite sides of an oscillator substrate such that they may be coupled to the oscillator circuit by their normal mounting means. The resonators can be disposed side by side on the same surface of an oscillator substrate with the first resonator inverted 180° and mounted on its top with connections to the substrate. The oscillator can be configured such that the resonators are disposed back to back on the same surface of an oscillator substrate said resonators being mounted on their sides so that electrical connection to all of the electrodes may be made directly to the substrate.
An embodiment of the present invention also includes a method for improving the acceleration resistance of a quartz crystal controlled oscillator comprising (a) manufacturing a plurality of crystal resonators having acceleration sensitivity vectors that point in substantially the same direction relative to the mounting surface of the resonator, (b) determining the magnitude of the acceleration sensitivity component in the axis normal to the mounting plane of the crystal for all crystals in the group, (c) selecting a first crystal and a second crystal that exhibit acceleration sensitivity magnitudes that are substantially the same within a predetermined tolerance, (d) mounting the second said crystal such that its mounting plane is rotated 180° either around the x axis in the y-z plane or around the y axis in the x-z plane relative to the first crystal, aligning the two acceleration sensitivity vectors in a substantially anti-parallel arrangement, (e) coupling said crystal pair to the oscillator circuit so that the combination performs as a composite resonator to control the frequency of the oscillator.
BRIEF DESCRIPTION OF THE DRAWINGS
FIG. 1 illustrates a crystal oscillator assembly having a composite dual crystal resonator.
FIG. 2 illustrates a cross-sectional view of the composite resonator indicating the relative relationship of the crystal blanks and the mounting structure.
FIG. 3 illustrates a cross-sectional side view of an embodiment of the invention wherein the two matched crystals are mounted on opposite sides of an oscillator substrate.
FIG. 4 illustrates an embodiment wherein the two matched crystals are mounted side by side on the same surface of the oscillator substrate.
FIG. 5 illustrates a further embodiment of the oscillator wherein the two crystals are mounted on the oscillator substrate with the packages turned on their sides.
FIG. 6 illustrates an embodiment of an oscillator including a composite dual crystal resonator on a substrate containing the circuitry to implement a Temperature Compensated Crystal Oscillator (TCXO).
FIG. 7 illustrates an embodiment of an oscillator wherein the composite crystal resonator is included in an Oven Controlled Crystal Oscillator (OCXO).
FIG. 8 illustrates the axis definitions of a single rectangular quartz crystal resonator.
DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS
Referring now to FIG. 1 , an embodiment of a crystal oscillator 30 can be configured with a composite dual crystal resonator in which the crystals are mounted with their normal mounting planes parallel to the surface plane of the circuit substrate 18 . The oscillator 30 includes a first crystal resonator 10 and second crystal resonator 12 which are both electrically connected to the circuit with conducting jumpers 22 to form composite resonator 15 . Preferably, the crystal resonators 10 and 12 have been manufactured so that their Γ or acceleration sensitivity vectors 14 and 16 are pointing in the same direction relative to the normal mounting planes of the resonator packages 36 and 38 . Therefore, when the first crystal 10 is inverted with relation to the second crystal 12 and mounted on top of it with the mounting planes parallel to each other, the acceleration sensitivity vectors 14 and 16 are essentially anti-parallel or pointing in opposing directions. While an arrangement with the acceleration sensitivity vectors exactly anti-parallel is preferred, vectors that are nearly anti-parallel may still provide the desired acceleration insensitivity. For instance, in some embodiments, the desired acceleration insensitivity benefits can be achieved where the acceleration vectors are within 5° off of anti-parallel. However, where the acceleration vectors are arranged more than 10° off of anti-parallel, the benefits can substantially diminish. Therefore, it is preferable that the acceleration vectors be within 10° of anti-parallel, and it more preferable that the vectors are within 5° of anti-parallel.
In one embodiment, the preferred crystal for the oscillator is a rectangular resonator strip crystal known as an “AT” cut crystal. This particular cut of crystal has a very low temperature coefficient with the inflection temperature near +25° C. so that frequency variations are minimized in most applications. The temperature characteristic of a quartz crystal is primarily determined by the angle that the resonator wafer is cut from a quartz bar relative to the crystal lattice. While the implementation of an anti-parallel cancellation technique is well suited to the AT cut, it may also be accomplished with any other family of cuts having an acceleration sensitivity in three axes.
The crystal resonators can be configured in an inverted position by rotating the first crystal 10 resonator 180° around either the x or y axis and directly mounting the first crystal on top of the second crystal 12 . FIG. 8 illustrates an embodiment of a rectangular resonator 10 and a three axis coordinate system 50 which defines the axes relative to the faces of the resonator. The z axis ({right arrow over (z)}) points outward from the top of the package (a major face). The x axis ({right arrow over (x)}) points outward from the side (the long minor face). The y axis ({right arrow over (y)}) points outward from the end of the package (the short minor face).
The illustrated configuration effectively causes cancellation of the acceleration sensitivity of the composite resonator due to the vector nature of the crystal acceleration parameter. Crystal electrode pads 27 and 28 can be connected to the circuit with conducting jumpers 22 so that they can be operated either in parallel or series configuration in the oscillator circuit. The crystal oscillator 30 can also be configured to include a circuit substrate 18 supporting passive and active oscillator components 20 .
FIG. 2 shows a cross-sectional side view of an embodiment of a composite resonator 15 exposing the first internal quartz crystal blank 24 of first crystal resonator 10 and the second internal quartz crystal blank 26 of the second crystal resonator 12 . Electrode pads 27 can be connected to the electrode deposited on of crystal blanks 24 and 26 . Circuit traces within the crystal packages connect pads 28 to the electrode deposited on the other side of the crystal blanks 24 and 26 . Preferably, the crystals are configured as part of a crystal resonator package which can include circuit traces, electrodes, the crystals, and other resonator materials. In constructing the composite resonator, first crystal resonator 10 can be rotated or inverted 180° and placed on top of the second crystal resonator 12 . The first resonator 10 is preferably rotated 180° around the x or y axis, as shown in FIG. 8 , so that planes 36 and 38 are mounted parallel to one another, and the acceleration sensitivity vectors 14 and 16 are aligned essentially anti-parallel. Although the vectors of the preferred embodiment are aligned exactly anti-parallel, other embodiments may have desired acceleration benefits where the vectors are aligned within 5° and 10° of anti-parallel. Conductive straps 22 can connect the electrode pads 27 and 28 of the first crystal resonator 10 to the electrode pads 27 and 28 of the second crystal resonator 12 . The crystal resonators can also be coupled together using other means such as adhesive, use of the substrate, etc.
FIG. 3 illustrates an embodiment of an oscillator wherein the matched crystal resonators 10 and 12 are disposed on opposite sides of an oscillator circuit substrate 18 . In this manner, the crystal resonators 10 and 12 can each be attached to a substrate and circuit while maintaining the acceleration resistant positioning relative to one another. Preferably, the substrate has a uniform thickness so that the mounting plane of the first crystal 36 is parallel to the mounting plane of the second crystal 38 . As the orientation of the first crystal has been inverted 180° around either the x or y axis, the acceleration sensitivity vectors 14 and 16 are essentially anti-parallel, pointing in opposite directions. Although the vectors of the preferred embodiment are aligned exactly anti-parallel, other embodiments may have the desired acceleration benefits where the vectors are aligned within roughly 5° and 10° of anti-parallel. The electrodes on crystal blanks 24 and 26 can be connected through the crystal package to the electrodes 27 and 28 . The electrodes can then be connected together by conductive circuit board via the circuit elements 40 and 42 which complete the connection to the oscillator circuit either in a parallel or series configuration.
FIG. 4 shows a further embodiment of an oscillator wherein two matched crystal resonators 10 and 12 are mounted side by side on the same surface of an oscillator substrate 18 . Crystal resonator 10 is inverted or rotated 180° about the x or y axis and mounted on its top surface so that the mounting planes 36 and 38 are parallel and the acceleration sensitivity vectors 14 and 16 are essentially anti-parallel. Although the acceleration vectors of the preferred embodiment are aligned exactly anti-parallel, other embodiments may have desired acceleration benefits where the vectors are aligned within roughly 5° and 10° of anti-parallel. The crystal resonators 10 and 12 can be coupled directly to the substrate and can also be coupled to one another. Preferably, the crystal resonators have been manufactured so that the Γ vectors 14 and 16 are pointing in a consistent direction relative to the mounting surface of each crystal. The electrode pads 27 and 28 of the inverted crystal 10 can be connected to the oscillator substrate 18 with connecting jumpers 22 .
FIG. 5 shows a further embodiment of an oscillator wherein the two matched resonators 10 and 12 are mounted on their sides with their normal mounting surfaces 36 and 38 facing outward in opposite directions. This allows crystal pads 27 and 28 to be electrically connected to the oscillator substrate 18 directly without requiring additional connecting jumpers. Acceleration sensitivity vectors 14 and 16 are thereby aligned anti-parallel in the horizontal plane. While it is most beneficial for the Γ vectors to be aligned exactly anti-parallel, substantial acceleration benefits can be achieved if the vectors are aligned within 10° of anti-parallel. The crystal resonators 10 and 12 can be mounted to the substrate and can also be coupled to one another. The oscillator can also include active or passive elements 20 configured on the substrate 18 .
FIG. 6 illustrates an embodiment of an oscillator 60 wherein the two matched resonators 10 and 12 are mounted in an inverted position or back to back with the mounting plane of resonator 10 rotated 180° around the x axis in the y-z plane. The acceleration sensitivity vectors of the crystal resonators 10 and 12 are arranged essentially anti-parallel. While it is most beneficial for the Γ vectors to be aligned exactly anti-parallel, substantial acceleration benefits can be achieved if the vectors are aligned within 10° of anti-parallel. This composite resonator is disposed on an interconnecting substrate 64 . Conductive straps 22 can connect the two resonators together and to the interconnecting substrate 64 . A TCXO circuit 62 can also be mounted on the substrate 64 in order to produce a temperature compensated crystal oscillator 60 . The TCXO circuitry 62 generates a correction signal to compensate and minimize the frequency drift of the resonator as the ambient temperature varies.
A TCXO with acceleration sensitivity vector cancellation based on embodiments of the invention has a g-sensitivity less than 0.05 parts-per-billion (ppb) or 5×10 −11 per g of applied acceleration force. This is at least an order of magnitude improvement compared to other TCXOs currently available. Also, when operating under random vibration, such a TCXO can improve the phase noise by more than 40 dB compared to conventional TCXOs. In an embodiment of an acceleration sensitivity cancelling TCXO, the frequency stability can be ±1 ppm over −40° to +70°. The input supply voltage can be +3.3 Vdc to +5 Vdc at 10 mA. Also, the low phase noise output can be CMOS compatible with 50/50±5% duty cycle. This can provide electronic frequency control for precise tuning or phase locking applications.
FIG. 7 illustrates a further embodiment of an oscillator 80 wherein the two resonators 10 and 12 are mounted in an inverted or back to back position with the mounting plane of resonator 10 rotated 180° around the x axis in the y-z plane. The acceleration sensitivity vectors of the crystal resonators 10 and 12 are arranged essentially anti-parallel. While it is most beneficial for the Γ vectors to be aligned exactly anti-parallel, substantial acceleration benefits can be achieved if the vectors are aligned within 10° of anti-parallel. This composite resonator is then mounted to a planar oven substrate 72 . On the substrate is also a heat source 68 , temperature sensor 66 , oscillator circuit 70 and oven control circuit 69 which proportionally controls and stabilizes the heat source 68 to maintain the resonators at a precise temperature even when the outside or ambient temperature varies. The oven controlled crystal oscillator is housed within a package consisting of supporting header 74 and cover 76 . Therefore, the oscillator 80 is less sensitive to acceleration forces and is also oven controlled.
It should be pointed out that while what has been described here are several embodiments of the invention, it may be possible to implement various modifications and variations without departing from the intent and scope of the invention. Although the invention presented herein has been disclosed in the context of certain preferred embodiments and examples, it will be understood by those skilled in the art that the invention extends beyond the specifically disclosed embodiments to other alternative embodiments and/or uses of the invention and obvious modifications and equivalents thereof. Thus, it is intended that the scope of the invention herein disclosed should not be limited by the particular embodiments described above, but should be determined only by a fair reading of the claims.
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A crystal oscillator having a plurality of quartz crystals that are manufactured so that the directional orientation of the acceleration sensitivity vector is essentially the same for each crystal. This enables convenient mounting of the crystals to a circuit assembly with consistent alignment of the acceleration vectors. The crystals are aligned with the acceleration vectors in an essentially anti-parallel relationship and can be coupled to the oscillator circuit in either a series or parallel arrangement. Mounting the crystals in this manner substantially cancels the acceleration sensitivity of the composite resonator and oscillator, rendering it less sensitive to vibrational forces and shock events.
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BACKGROUND
Moist cargo materials hauled in dump bed trucks can freeze and stick to the truck bed in cold weather. Frozen cargo materials are difficult and sometimes dangerous to dump from the truck bed.
DESCRIPTION OF THE DRAWINGS
FIG. 1 illustrates one example of a dump bed truck that may be adapted for use with embodiments of the invention.
FIGS. 2-6 illustrate a dump bed truck with a truck bed heater constructed according to an embodiment of the invention.
FIGS. 7-9 illustrate a dump bed truck with a truck bed heater constructed according to an embodiment of the invention.
FIGS. 10-12 illustrate examples of discharge nozzles for the hot exhaust gases used to heat the truck bed.
FIGS. 13-14 illustrate an arrangement of valves that may be used to control the flow of exhaust between the truck bed heater and the truck muffler and exhaust stack.
FIGS. 15-16 illustrate a dump bed truck with a truck bed heater constructed according to an embodiment of the invention.
FIG. 17 illustrates a truck bed heating system according to an embodiment of the invention.
DETAILED DESCRIPTION
Embodiments of the invention were developed in an effort to make it easier and safer to dump frozen materials from a dump bed truck. Exemplary embodiments, therefore, will be described with reference to a dump bed truck. Embodiments of the invention, however, are not limited to use on dump bed trucks. Embodiments may be adapted for use with other exhaust generating vehicles including flat bed trucks, tractor-trailer rigs and pick-up trucks. The exemplary embodiments shown in the figures and described below illustrate but do not limit the invention. Other forms, details, and embodiments may be made and implemented. Hence, the following description should not be construed to limit the scope of the invention, which is defined in the claims that follow the description.
FIG. 1 illustrates a dump bed truck 10 that may be adapted for use with embodiments of the invention. Truck 10 includes a cab 12 and a dump bed 14 containing cargo 16 . The front of bed 14 may be hoisted up to dump cargo 16 out the back of bed 14 . Truck 10 also includes an engine (not shown) that generates hot exhaust gases discharged through an exhaust stack 18 . Dump bed truck 10 represents generally any vehicle that generates hot exhaust gases and includes a bed or container capable of holding cargo, including containers that are only temporarily attached to the truck (roll-on trash containers, for example).
FIGS. 2-6 illustrate a dump bed truck 20 with a truck bed heater 22 constructed according to one embodiment of the invention. Only the outline of the truck bed is shown in the plan view of FIG. 4 so that the components of heater 22 under the bed are visible. The truck bed is shown in section in FIGS. 5 and 6 . Referring to FIGS. 2-6 , truck 20 includes a cab 24 , a dump bed 26 and a hydraulic hoist 28 that lifts bed 26 as shown in FIGS. 3 and 6 . The truck engine (not shown) discharges hot exhaust gases to an exhaust pipe 30 . Exhaust pipe 30 carries exhaust to a muffler/stack 32 and/or to an intake pipe 34 for bed heater 22 . A pair of butterfly valves 37 and 39 ( FIGS. 13-14 ), for example, control the flow of exhaust from pipe 30 to stack 32 and intake pipe 34 . Heater intake pipe 34 carries exhaust to a manifold 38 from which exhaust is channeled to jetted distribution pipes 40 . In the embodiment shown, manifold 38 is a continuation of intake pipe 34 . Hot exhaust gases are discharged from each distribution pipe 40 through a series of openings 42 extending along the length of pipes 40 . Manifold 38 and distribution pipes 40 are mounted to a frame 44 that supports bed 26 .
Where distribution pipes 40 are mounted to the movable dump bed frame 44 , as shown in FIGS. 4-6 , a quick disconnect 46 on intake pipe 34 allows bed heater 22 to more easily disconnect and connect to the truck exhaust as bed 26 is alternately raised and lowered. Quick disconnect 46 may include, for example, a hood that fits tightly down over the end of intake pipe 34 as best seen in FIGS. 5 and 6 . The hood may be lined with rubber or another suitable sealing material to help seal the pipe connection at disconnect 46 . In the embodiment shown in FIGS. 7-9 , in which distribution pipes 40 are attached to the stationary truck frame 47 , the quick disconnect is omitted.
In the embodiment shown in FIGS. 2-9 , two distribution pipes 40 extend parallel to one another along nearly the full length of bed 26 . Each pipe 40 is positioned approximately mid-way between the center of bed 26 and the sides of bed 26 . Openings 42 are depicted in FIGS. 4 and 5 as a series of evenly spaced nozzles that direct the flow of gas up out of pipes 40 onto the bottom of bed 26 . Other configurations are possible. Several factors may influence the configuration for any particular application including, for example, the size of the truck bed, the heat transfer characteristics of the bed, the nature of the cargo and the climatic conditions in which the bed will be used. Alternative configurations may include, for example, more or fewer distribution pipes, distribution pipes that diverge or converge along the length of the bed, more or fewer openings, openings that are clumped together along the pipe, and distribution pipes along the sides of the bed.
FIGS. 10-12 illustrate different exemplary embodiments for exhaust discharge openings 42 in distribution pipes 40 . In the embodiment shown in FIG. 10 , opening 42 is constructed as a simple opening in the top of pipe 40 . In the embodiment shown in FIG. 11 , opening 42 is constructed as a straight nozzle 48 protruding from the top of pipe 40 . In the embodiment shown in FIG. 12 , opening 42 is constructed as a nozzle 50 that protrudes horizontally from the side of pipe 40 and makes a 90° bend to vertical. Nozzle 50 in FIG. 12 includes an oxidizing catalyst 52 to increase the temperature of the exhaust gases discharged from nozzle 50 . An air injection venturi 54 feeds air into catalyst 52 to aid oxidation.
FIGS. 13 and 14 illustrate an arrangement of butterfly valves 37 and 39 for controlling the flow of engine exhaust from pipe 30 to heater intake pipe 34 and stack 32 . Valves 37 and 39 are opened and closed by a solenoid 56 acting through a linkage 58 connecting solenoid 56 to each valve 37 and 39 . In FIG. 13 , solenoid slider 60 is fully extended so that valve 37 to heater intake pipe 34 is fully closed, valve 39 to stack 32 is fully open and all of the exhaust flows to stack 32 . In FIG. 14 , solenoid slider 60 is fully retracted so that valve 39 to stack 32 is closed, valve 37 to intake pipe 34 is open and all of the exhaust flows through intake pipe 34 . It may be desirable under some operating conditions to have each valve 37 , 39 partially open to split the flow of exhaust between stack 32 and heater intake pipe 34 . In this way, the flow of hot exhaust gases to bed heater 22 may be regulated to help achieve the desired heating of bed 26 . The valve control system illustrated in FIGS. 13-14 is just one example of a suitable control system. Other systems are possible. For example, the valves may be operated manually or each valve may be operated by its own solenoid and connecting linkage.
In the embodiment shown in FIGS. 15-16 , a gas burner 62 is added to truck bed heater 22 to increase the temperature of the hot gases used to heat truck bed 26 . FIG. 17 illustrates a control system for a gas burner assisted truck bed heater 22 . Referring to FIGS. 15-17 , gas burner 62 is connected to heater intake pipe 34 . Burner 62 includes an electronic ignitor 64 to ignite natural gas, propane or another suitable gas delivered to burner 62 from gas tank 66 through a feed pipe 68 . The flow of gas from tank 66 to burner 62 is controlled by a pressure regulator 69 and flow control valve 70 . Where gas tank 66 is located remote from burner 62 , mounted to the cab or truck frame for example, then a flexible tubing feed pipe 68 may be used along with a quick disconnect at control valve 70 .
An electronic programmable controller 72 may be used to achieve the desired flow of hot gases to heater intake pipe 34 by regulating flows from the engine exhaust and heat from gas burner 62 . Controller 72 , therefore, is operatively connected to gas burner flow control valve 70 , ignitor 64 and exhaust valve actuator solenoid 56 . Gas burner 62 is one example of a secondary heat source that may be used to supplement the heat provided by exhaust from engine 76 . Control inputs to controller 72 may include, for example, a temperature signal from a thermocouple 74 to monitor the temperature of gases entering manifold. 38 , air temperature, truck bed temperatures, engine exhaust flow rates and temperatures, and gas burner temperature.
While the configuration of components of heater 22 may be varied to achieve a desired performance for a particular truck bed, it is expected that two 4″-5″ diameter distribution pipes and a corresponding number of ¾″-1″ diameter nozzles will adequately heat the floor of a typical roll-on trash container carried by a diesel fueled truck engine. In one example, heater manifold 38 is a 5″ diameter steel pipe. Two 4″ diameter steel distribution pipes 40 connected to manifold 38 extend along the full length of the trash container/bed 26 . The floor of trash container dump bed 26 is 20′-0″ long and 7′-0″ wide and made from 3/16″ thick steel plate. Each distribution pipe 40 is positioned 2′-7″ from the side of bed 26 , leaving 1′-10″ between pipes 40 . Twelve 1″ diameter nozzles 48 are spaced 1′-6″ apart along the length of each distribution pipe 40 . The tip of each nozzle 48 is approximately 3″ below the underside of bed 26 . The ratio between the cross-sectional area of each distribution pipe and the cross-sectional area of each opening or nozzle for such a trash container configuration is in the range of 16 (for a 4″ diameter pipe and 1″ nozzles) to 45 (for a 5″ diameter pipe and ¾ nozzles).
The present invention has been shown and described with reference to the foregoing exemplary embodiments. It is to be understood, however, that other forms, details, and embodiments may be made without departing from the spirit and scope of the invention which is defined in the following claims.
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In one embodiment, a heater for a vehicle having an engine that generates hot exhaust gases includes a distribution pipe extending along a cargo carrying part of the vehicle. The distribution pipe is operatively connected to an engine exhaust pipe such that engine exhaust can flow through the distribution pipe when the engine is running. The distribution pipe has a plurality of openings therein through which exhaust is discharged to heat the cargo carrying part of the vehicle when the engine is running. Each opening has a cross-sectional area substantially smaller than a cross-sectional area of the distribution pipe.
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This application is a continuation-in-part of my prior copending application, Ser. No. 07/114,210 filed Oct. 28, 1987, now abandoned.
BACKGROUND OF THE INVENTION
The present invention relates to the fabrication of boat hulls from various synthetic resin materials and, more specifically, to a novel method and apparatus for fabricating high strength boat transoms. Most contemporary boat hulls, measuring from a few feet up to 100 feet or more in length, are fabricated from some form of fiberglas reinforced polyester resin. It is still a widespread practice in the industry, however, to fabricate the transom out of marine or exterior grade plywood with layers of fiberglas and resin on each face. After comparatively few years of usage, small leaks develop in the plastic skin and fastener holes, causing water to be soaked up by the plywood core. This leads to delamination and ultimately rotting of the plywood, with consequent failure of the transom. The problem is particularly acute in boats where large high-powered outboard, or inboard-outboard, motors are mounted on or through the transom.
SUMMARY OF THE INVENTION
One object of the present invention is to provide a novel boat transom construction and method of making same which is far superior to a conventional marine plywood transom from the standpoint of strength and durability.
Another object of the invention is to provide a boat transom of the character set forth above and a method for making same, giving the transom excellent resistance to impact loads.
A further object of the invention is to provide a boat transom and method of constructing same, giving the transom excellent resistance to torsion loads generated by an outboard, or inboard-outboard, motor.
Still another object of the invention is to provide a boat transom of the character set forth above having greater strength and durability at substantially lower cost than transoms of the type known heretofore.
Other objects and advantages of the invention will become apparent as the following description proceeds, taken with the accompanying drawings.
The foregoing objects are accomplished by taking advantage of the outer skin of the hull and transom while still in the hull mold; providing a temporary bulkhead spaced forward of the outer skin of the transom by the desired thickness of the transom body; filling the transom body cavity between the outer skin and the bulkhead with synthetic resin containing a catalyst or hardener and microspheres of glass or other material to minimize weight, and laying down the transom body in a series of layers of the resin containing fiberglas reinforcing which extends in zig zag fashion from side edge to side edge of the transom cavity until the latter is completely filled. The above objects are also accomplished by casting a fiberglas reinforced synthetic resin transom body in a generally horizontal mold, or an upright mold, separate from the hull mold.
BRIEF DESCRIPTION OF THE DRAWINGS
FIG. 1 is a fragmentary perspective view of a boat hull and transom embodying the present invention under construction in a hull mold.
FIG. 2 is an enlarged, fragmentary, transverse sectional view of the transom forms in position for receiving the fiberglas reinforced resin material, taken in the plane of the line 2--2 in FIG. 3.
FIG. 3 is a vertical sectional view taken in the medial plane 3--3 of the transom upon completion of the casting operation.
FIG. 4 is an enlarged, fragmentary, transverse sectional view showing the transom of FIG. 2 after it has been completed.
FIGS. 4A and 4B illustrate a modified method of fabricating the transom in a hull mold utilizing a relatively heavy fibergl bulkhead spaced forwardly from the outer fiberglas skin and rigidly connected thereto by fiberglas filets.
FIG. 5 is an enlarged, fragmentary perspective view of the stern portion of a boat in the hull mold having a transom being formed with reinforcing gussets cast integrally therewith.
FIG. 6 is an enlarged, fragmentary, transverse sectional view through the completed transom with gussets as formed in FIG. 5.
FIG. 7 is an enlarged, fragmentary, vertical sectional view through an apparatus for fabricating a boat transom utilizing fiberglas tape in accordance with the novel method described herein.
FIG. 8 is a fragmentary plan view of the apparatus as shown in FIG. 7.
FIG. 9 is a view similar to FIG. 7 but showing the use of fiberglas roving in constructing the transom instead of fiberglas tape.
FIG. 10 is a plan view illustrating a variant of the method described earlier herein and utilizing a peripheral open faced mold supported on a table or other flat supporting surface.
FIG. 11 is an elevational view of the wider side of the mold shown in FIG. 10 resting upon an underlying supporting surface.
FIG. 12 is a vertical sectional view through the mold and cast transom in the plane of the line 12--12 in FIG. 10 showing the fiberglas roving used for reinforcement.
FIG. 13 is an elevational view showing the V-shaped side of the mold opposite to the wider side shown in FIG. 11.
FIG. 14 is a horizontal sectional view taken laterally through the mold and the cast transom in the plane of the line 14--14 in FIG. 10 showing the fiberglas roving reinforcement therein.
FIG. 15 is a fragmentary perspective view of the stern portion of a boat in a hull mold having a transom body being cast from a mixture of synthetic resin and fiberglas reinforced plastic scrap supplied by two units in series.
FIG. 16 is a view similar to FIG. 15 wherein the synthetic resin and fiberglas reinforced plastic scrap are supplied by a single unit.
FIG. 17 is a plan view of a horizontal open faced mold for casting a transom body from fiberglas reinforced plastic scrap and synthetic resin separately from the hull mold.
FIG. 18 is an elevational view of the mold shown in FIG. 17.
FIGS. 19 and 20 are vertical and horizontal sectional views, respectively, through the mold and transom body therein.
FIG. 21 is an enlarged fragmentary, horizontal sectional view through a completed transom made from fiberglas reinforced plastic scrap and synthetic resin.
DETAILED DESCRIPTION OF THE INVENTION
Referring more specifically to FIGS. 1-9, the invention is there exemplified in a novel boat transom 10 and method for fabricating same whereby the transom will have exceptionally high strength and great impact resistance. The initial step in constructing such a transom starts with the build-up of a fiberglas reinforced outer skin 11 in a hull mold 12 having a cavity 14 which defines the outer configuration of the hull, including the outer fiberglas skin 15 of the transom. A temporary bulkhead 16 is mounted in spaced relation to the outer skin 15 of the transom so as to define a space of the desired thickness for the transom body (FIGS. 1, 2, 5, 7-9). The temporary bulkhead 16 is fashioned with pairs of engagement lugs 18 rigidly connected in any suitable manner to the hull mold. The bulkhead 16 has a seal 19 between the fiberglas outer skin 11 and the bottom edge of the bulkhead. The seal may also be extended along the side edges of the bulkhead.
The next step in the method is to fill the space between the outer skin of the transom and the removable bulkhead with a body 20 of synthetic resin, which may be polyester or some other moldable resin. Filler such as microspheres may be added to reduce weight without sacrificing strength. As an incident to the filling operation, internal reinforcing strands of synthetic resin fibers having high tensile strength, such as fiberglas tape 21, or fiberglas roving 22, are deployed generally horizontally in layers running from side edge to side edge of the transom (FIG. 3). This process continues until the space between the outer skin of the transom and the removable bulkhead has been filled with the body 20 of reinforced synthetic resin. At that point, the temporary bulkhead is removed and the exposed front face 24 of the transom body is covered with fiberglas reinforced resin skin 25 which is also adhesively connected to the outer skin side and bottom walls of the boat while still in the hull mold. The top of the transom is then finished off with this same material.
In accordance with another aspect of the invention, a modified method of fabricating the transom is defined (FIGS. 4A, 4B). The fiberglas outer skin 11 of the boat is built up in the hull mold as previously described. A relatively heavy fiberglas bulkhead 26 is then erected, being spaced from the outer skin of the transom by the thickness of the plastic transom body to be constructed in the cavity between the fiberglas bulkhead and the fiberglas outer skin 11 of the transom. The bulkhead 26 itself is rigidly connected to the outer skin of the sides and bottom of the boat, as by means of suitable adhesive and fiberglas fillets, while still in the hull mold.
With the fiberglas bulkhead 26 in place, the transom body is then constructed by injecting the necessary synthetic resin material along with reinforcing such as fiberglas tape or roving. This material is laid down in reinforced layers running from side edge to side edge of the transom until the cavity between the bulkhead and outer skin of the transom has been filled. The next step includes finishing the top edge of the transom with a fiberglas resin skin.
To provide additional stiffness in the transom 10, the latter may be reinforced by appropriate gussets 42 (FIGS. 5 and 6). In this instance a relatively heavy temporary bulkhead 28 is utilized and set in position forwardly of the fiberglas outer skin 15 of the transom by an amount equal to the thickness of the transom body about to be cast. The bulkhead 28 includes a pair of hollow triangular gusset forms or knees 29 communicating with the transom body cavity. The hollow on the inside of each gusset form 29 is filled in when the transom body material is inserted into the gap between the outer skin of the transom and the bulkhead 28 spaced inwardly from the transom. The gusset material is integral with the transom body 20 and binds readily to the outer fiberglas skin 11 on the bottom of the boat.
The completed transom is a laminated structure comprising a core or body 20 of fiberglas reinforced synthetic resin. The body is securely bonded to a reinforcing laminate which on the outer face is the outer skin 15 of the transom and on the inner face is a fiberglas resin bulkhead bonded to the transom body 20 and to the side and bottom walls of the hull. This laminate sandwich construction imparts a high degree of stiffening to the transom body, resulting in a transom having exceptionally great strength and the ability to absorb a severe impact without damage. It is less expensive than a conventional marine plywood transom and may readily be incorporated into a fiberglas plastic hull. It may also be utilized to replace an existing plywood transom which has started to deteriorate.
In further accordance with the invention, apparatus 30 has been provided for reinforcing and injecting the material for the transom body 20 into the body cavity 23 (FIGS. 1, 5, 7-9). The apparatus 30 in this instance comprises a relatively large injection gun 31 having a barrel 32 of appropriate length and diameter to fit easily into the transom body cavity 23. The upper end of the barrel 32 is connected to a collecting chamber 34 for the filling material which ultimately becomes the transom body 20. While it is conceivable that the injection gun 31 could be held and operated manually, it would be preferable to utilize a power assisted suspension for manipulating the gun during construction of the transom.
The collecting chamber 34 is supplied with material from several sources in close proximity to the injection gun 31 (FIGS. 1, 5, 7-9). One such material, as previously indicated, is polyester or other synthetic resin including microsphere filler to reduce weight. This material is supplied from a source 35 via a relatively large diameter flexible conduit 36. The latter is connected to a control valve 38 on a manifold 37 fixed to the collecting chamber 34. A catalyst or hardener is injected into the manifold 37 via a smaller diameter conduit 39 and control valve 40. A mixing device 41 in the manifold 37 blends the catalyst with the synthetic resin and the blended resin is then passed into the collecting chamber.
Two types of fiberglas reinforcement can be supplied to the collecting chamber 34 for inclusion in the plastic resin which forms the transom body 20. The first type is fiberglas tape 21, illustrated in FIGS. 7 and 8. The tape 21 is drawn from a main supply spool 44 (FIGS. 1, 5), led over a small guide roller 45, and thence downward into the collecting chamber 34. A continuous length of the tape 21 is pulled down into the blended resin passing through the collecting chamber and the injection gun barrel 32. This is accomplished by means of air jets from one or more jet nozzles 46 in the collecting chamber. The nozzles 46 are fed by high pressure air line 48 operated by control valve 49. The air jets can be pulsating as required.
The second type of fiberglas reinforcement in the transom is in the form of separate strands 22 called fiberglas roving (FIG. 9). This material is handled in much the same way as the tape. The roving comes from a main supply spool like the spool 44, thence over the small diameter guide roller 45, and downward into the collecting chamber 34. The air jets from the nozzles 46 draw a continuous length of roving down into the blended resin passing through the collecting chamber and into the barrel 32 of the injection gun.
In usage, the gun 31 is preferably machine operated so as to traverse the transom cavity in a direction laterally of the hull and thereby lay down the necessary courses of reinforced synthetic resin which ultimately define the transom core or body 20 (FIGS. 3, 7, 9). The gun barrel 32 has an appropriate diameter to fit easily within the gap between the outer skin 15 and the temporary bulkhead 16, 26 or 28 of the transom. It lays down successive courses of synthetic resin and entrained reinforcing material to completely fill the gap between the outer skin and the bulkhead. When the transom body cavity has been filled, the temporary bulkhead removed, and fiberglas skin applied to the front face of the transom the skin may be extended to cover the top of the transom if desired.
In accordance with a further aspect of the invention, provision is made for casting a reinforced synthetic resin transom separately from the hull mold. Referring more specifically to FIGS. 10-14, a generally horizontal open faced mold 50 is provided. The mold is made in sections 51, 52, 53, 54 and 55, all of generally L-shaped cross section. The mold sections are detachably connected to each other and to an underlying table or other horizontal supporting surface 56. The detachable connections 58 may be of any conventional, quick acting type. The common upstanding inner surface 59 of the mold sections defines the perimeter of the transom to be cast.
To construct a transom body 60 in the mold 50, an injection gun 31 similar to the ones described earlier herein is used. The gun 31 is held upright over the mold and reciprocated back and forth to lay down a body of reinforced plastic material. The reinforcement may be fiberglas tape 21 or roving 22, described earlier herein, or other reinforcing strands of high tensile strength synthetic resin. Such reinforcement is injected into the mold along with the plastic body material. The mold is filled to its top face and then smoothed off. After the plastic has set, the mold sections may be released and the transom body removed from the mold. It may then be installed in a boat hull in the conventional manner.
The applicant has developed a new and unique method of manufacturing boat transoms which not only reduces costs significantly but also adds substantially to the strength of the finished product. It has been known to reinforce polyester resin transoms with fiberglas tape or roving as noted earlier herein. Applicant has, however, discovered a novel way to increase substantially the strength of the transom while greatly reducing its cost. A transom made by this process will not warp, delaminate or rot and has far superior impact and compression strength in comparison to plywood.
Applicant's novel method comprises using the basic polyester resin transom mix and adding ground fiberglas reinforced plastic material such as trimmings, cut-outs, overspray, and still residue after the solvent has been drawn off. This material, normally considered scrap, may be coarse ground, or may be broken up in a hammer mill, in such a way that the majority of the fiberglas fibers are left intact. This contributes greatly to the strength of the final product. The polyester resin also contains numerous microspheres which not only serve to reduce the weight of the mix but also hold the dispersed fibers and ground particles in suspension. It has been found effective to use as much as 50% scrap in the transom body mix. This mix permits the transom material to be pre-constructed and placed in a hull as is done with plywood, or it can be cast directly in place using an injection gun.
For casting the transom body using the mix just described, two types of supply unit may be utilized. The first type comprises a polyester resin supply unit 65 which injects synthetic resin via a flexible conduit 66 into a scrap mixing unit 68 (FIG. 15). The latter includes a coarse grinder 69 which breaks up the scrap S while preserving most of the entrained fibers. The coarse grinder 69 mixes the resin and microspheres with the coarse ground scrap and conducts the mix via flexible conduit 70 to the casting gun 71. The gun 71 which may be manually or power actuated, then casts the transom body 72 in an appropriate mold. This may be either the transom body cavity 74 at the stern of the boat 75, or the separate transom body mold 76 shown in FIGS. 17-20.
The second type of supply unit 78 is a single entity which accepts both the polyester resin and the broken scrap S. The unit 78 mixes together the three ingredients, resin, scrap and microspheres, and conducts the resulting mix via a flexible conduit 79 to the casting gun 71. The latter may also be power or manually actuated and is adapted to cast the transom body in the transom cavity of the boat, or in the separate transom body mold shown in FIGS. 17-20.
Turning now to FIG. 21, there is shown an enlarged, fragmentary, horizontal sectioned view taken through a finished transom body 80 and made in accordance with the novel method described in the six preceding paragraphs. This particular transom body happens to be approximately 17/8 inches thick. It has an exposed outer surface faced with a fiberglas layer 81 approximately 3/16 to 1/4 inch thick and an exposed inner surface faced with a fiberglas layer 82 approximately 1/8 inch thick. The core 84 of the transom, comprising in this instance approximately 43% reground scrap, is slightly over 11/2 inches thick. The substantially even distribution of the reinforcing fibers 85 is readily apparent upon inspection of the sample. A transom constructed in this manner is capable of withstanding impacts many times greater than one made of plywood and has far greater longevity.
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A boat transom and method of constructing same utilizing the outer skin of the hull and transom while still in the hull mold. A bulkhead is disposed in forwardly spaced relation to the outer skin of the transom and the space therebetween is filled with high tensile strength synthetic resin which may be of the polyester type blended with a suitable hardener. The resin includes entrained microspheres evenly dispersed throughout the transom body and ground fiberglass reinforced plastic scrap. The transom body is cast in a series of merging layers containing fiberglass reinforcing which extends in zig zag fashion from edge to edge of the transom body cavity and additional strands which extend in a skewed pattern. The bulkhead may be removed after the casting operation or may be allowed to remain in place. A further aspect of the invention involves the casting of a fiberglass reinforced synthetic resin transom body in a generally horizontal mold, or an upright mold, separate from the hull mold.
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BACKGROUND OF THE INVENTION
Field of the Invention
The present invention is related to a method for controlling the position of a cooking vessel which is placed inside a cooking appliance which rotates the cooking vessel as it cooks the food, and particularly to a method for automatically returning the cooking vessel to the same position at the completion of the cooking cycle as when the cooking vessel was initially placed in the cooking appliance.
Description of the Prior Art
In order to prevent food from being unevenly cooked due to a concentration of energy (for example, convection heat energy or microwave energy), a conventional cooking appliance with a concentrated(non-dispersed) energy emitting source heats the food while it rotates the cooking vessel. This cooking appliance may be in the form of a microwave oven which heats food by employing the principle of dielectric heating, an oven range which bakes food by the radiant heat emitted from a heater, or a complex type cooking appliance which employs both heating methods described above.
FIG. 1A is a diagram illustrating the position of a cooking vessel at the beginning of the cooking cycle, and FIG. 1B is a diagram illustrating the position of the same cooking vessel at the completion of the cooking cycle.
First, the user seizes handles 11 and 11' of cooking vessel 10 and places the cooking vessel 10 onto turntable 20 located in the lower portion of cooking chamber 30. Next, the user selects the desired cooking time or the desired function key and starts the cooking cycle.
In the specification, the term "handle" is used for designating any specific part of the cooking vessel 10, with which the user easily grasps and maneuvers the cooking vessel 10.
After the initial placement of the cooking vessel 10, the relative location of the handles 11 and 11' from the user's viewpoint is not convenient because the cooking vessel 10 is rotated on the turntable 20 during the cooking cycle. That is, after the cooking cycle, the location of the handles 11 and 11' may be in a straight line away from the user as shown in FIG. 1B. In this case, this causes a difficulty in removing the cooking vessel 10 which is heated by means of the cooking cycle from the cooking compartment 30.
To solve the problem described above, a system which is capable of automatically returning the cooking vessel to the position where the cooking vessel was initially placed, is disclosed in detail in Korean Patent Publication No. 92 - 6271. The system comprises a means for storing the time period required for each rotation of a synchronous motor (i.e., a full-rotation period), whose rotation speed (rotation period) varies in proportion to the frequency of the power supply source, and a means for determining the number of of full-rotation periods transpire from the beginning of the cooking cycle. Even after the cooking cycle is completed, the system continues to drive the synchronous motor for a partial-rotation time period calculated by subtracting from the full-revolution period, any rotation time exceeding the previous full-rotation period, thereby automatically returning the cooking vessel to the position where the cooking vessel was initially placed at the beginning of cooking cycle.
However, the system has a problem in that the rotation of the synchronous motor may be controlled by a time value which is different from the actual rotation time due to variations in the frequency of the power supply source or the weight of the cooking vessel and food.
SUMMARY OF THE INVENTION
It is an object of the present invention to provide a method for precisely returning a cooking vessel to the same position where it was initially placed at the beginning of the cooking cycle in a cooking appliance which cooks food while the cooking vessel rotates, thereby providing easy access to the cooking vessel handles.
The method according to the present invention is adaptable to a cooking appliance which comprises a cooking compartment, a turntable for rotating the cooking vessel put thereon, a motor for rotating the turntable, a plurality of rollers for supporting the turntable and which rotates at a speed proportional to that of the turntable, and a means for sensing the passage of the supporting rollers, thereby providing a uniform methods for cooking food while the cooking vessel rotates. The method comprises the steps of beginning the cooking cycle by rotating the turntable; counting the number of times the supporting roller passes the sensing switch; counting the time (tx) from the moment the turntable begins to rotate to the moment the first coming supporting roller passes the sensing switch, and storing the time (tx); counting the time (ty) between the first and second coming supporting rollers, and storing the time (ty); calculating the time (tz) by subtracting time (tx) from time (ty), and storing the time (tz); repeatedly counting after every supporting roller passes the sensing switch; and, when the cooking cycle is completed, rotating the turntable until each supporting roller has passed the sensing switch an equal number of times and the time (tz) lapses.
The method may be adapted for use in a cooking appliance having two supporting rollers, but preferably in a cooking appliance having three or more supporting rollers in order to prevent application of an excessive force to the axis of the motor caused by the off-center placement of the cooking vessel on the turntable.
In the method, the completion of the cooking cycle may comprises either the actual completion of the cooking cycle according to the control program or the forced interruption of the cooking cycle by user.
BRIEF DESCRIPTION OF THE DRAWINGS
These and other aspects of the present invention are clarified in the accompanying drawings in which:
FIG. 1A is a diagram illustrating the position of a cooking vessel at the beginning of the cooking cycle, and FIG. 1B is a diagram illustrating the position of the same cooking vessel at the completion of the cooking cycle when the present invention is not used; and,
FIG. 2 is a partial view of an oven showing a top view of the cooking compartment according to the present invention; and,
FIGS. 3A and 3B are flow charts describing steps for carrying out a method of the present invention.
DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS
Hereinafter, the preferred embodiments according to the present invention will be fully described, citing a microwave oven with a turntable as an example of a cooking appliance.
Referring to FIG. 2, supporting rollers 41 to 43 are is rotatably mounted at the outside end of respective radial supporting arms 40, each of which is designed to be the same length from the center and at the same angle to each other, to support a turntable (not shown) which rotates thereon. At least three supporting arms are preferable so that the turntable may be uniformly supported even when the positioning of the cooking vessel (not shown) is not centered on the turntable. The supporting rollers 41 to 43 should rotate about their respective axes at a speed proportional to that of the turntable, or, if possible at the same speed as the turntable. This may be achieved by forming a circular guiding groove (not shown ) in the bottom surface 31 of the cooking compartment in order that the supporting rollers 41 to 43 may pass only along the path described by the broken line. Alternatively, the supporting rollers may be attached to the bottom surface of the turntable. A sensing switch 50, which generates and transmits a signal to a control section (not shown) whenever the supporting rollers 41 to 43 pass thereover, is mounted in the path 32.
FIGS. 3A and 3B are flow charts describing a method of the present invention.
After the electric power is supplied to the micro-wave oven, the initiation of the process is executed in step S100, in which various counters tx and Rcount are cleared. If the user selects a cooking function, the program proceeds to Step S102 to start the cooking cycle. That is, a microwave energy generating mechanism (not shown) and a turntable rotating mechanism (not shown) are activated. At this time, the supporting rollers 41 to 43 are rotated about their axes by the friction force generated between the supporting rollers and the bottom surface 31 of the cooking compartment while supporting the turntable. In steps S104 to S108, the control section counts and stores the time (tx) from the beginning of the rotation of the turntable until the supporting roller 41, which is the first to come along in the direction of the rotation, passes by the sensing switch 50. At the same time, the value of a counter (Rcount) for the passing of the supporting roller 41 to 43 increases by 1. In step S110 and S112, the control section counts the time (ty) from the passage of the supporting roller 41 until the supporting roller 42, which comes second along the direction of the rotation, passes by the sensing switch 50. In step S114, the control section counts the time (ty) and the value of the counter (Rcount) increases by 1, again. At the same time, the control section stores the time (tz) obtained by subtracting time (tx) from time (ty). In step S116, the value of the counter (Rcount) increases by 1 when the supporting roller 43, which comes finally (in this embodiment) along the direction of the rotation, passes by the sensing switch 50. After all the supporting rollers 41 to 43 pass by the sensing switch 50 once via the foregoing steps S100 to S118, the value of the counter (Rcount) is repeatedly renewed to 1, 2 or 3 whenever the respective supporting roller 41 to 43 passes by the sensing switch 50 until the cooking cycle is completed in steps S120 and S122. Here, the completion of the cooking cycle may comprise either the actual completion of the cooking cycle of pre-set time duration according to the control program or the forced interruption of the pre-set cooking cycle by the user.
If the cooking cycle is completed in Step S122, the program proceeds to step S124, in which the control section determines whether or not the value of the counter (Rcount) is three. That is, the control section determines whether all of the supporting rollers 41 to 43 have passed by the sensing switch 50 the same number of times or not. If all supporting rollers 41 to 43 have not passed by the sensing switch 50, the program proceeds to step S126, in which the turntable continues to be rotated until all three rollers have passed by the sensing switch the same number of times. When all supporting rollers 41 to 43 have passed by the sensing switch 50 through the steps S124 and S126, the turntable continues to be rotated for the time (tz).
On the other hand, there is known a cooking appliance which automatically cooks food based on the weight of the food. Such cooking appliance comprises a weight sensor, for example, a piezoelectric transducer, mounted in the path of the supporting rollers. Accordingly, if the method of the present invention is incorporated into that cooking appliance, it is possible to sense the passage of the cooking vessel by a signal from the conventional weight sensor without requiring another sensing switch, thereby decreasing the manufacturing costs.
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A cooking vessel placed in a desired orientation on a turntable on an oven is automatically returned to that desired orientation at the end of a cooking operation. A sensor on the floor of the cooking chamber senses the movement of support rollers of the turntable to determine the angle by which the turntable must be rotated at the end of the cooking operation to bring the cooking vessel back to the desired orientation.
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TECHNICAL FIELD
[0001] The present invention relates to a structure for a front section of a vehicle body. In the structure, mounting members for supporting a subframe is arranged below front side frames.
BACKGROUND ART
[0002] Conventionally, in some cases, a mounting member formed with a vibration isolating rubber part is arranged above or below each front side frame, and a power unit and a subframe are supported by the mounting members, where the power unit includes an engine and a transmission and is mounted on the subframe. For example, in the case where the mounting members are arranged below the front side frames, the mounting members are fastened with bolts to nuts arranged on lower walls inside the front side frames, and the subframe is supported by the mounting members.
[0003] Meanwhile, Patent Literature 1 discloses an installation structure for a mounting apparatus wherein, when an engine mount is to be arranged above the front side frames, nut members for fixing the engine mount are arranged on upper walls of the front side frames each having a closed cross section, and the nut members are fixed to supporting plates, which extend to form a partition almost dividing the inner spaces of the front side frames. In the structure disclosed in Patent Literature 1, the inclination angles of the above supporting plates with respect to the length direction of the side frames are set such that the positions at which the front side frames are deformed by bending can be optimized.
CITATION LIST PATENT LITERATURES
[0000]
Patent Literature 1: Japanese Patent Laid-open No. 2006-219068 (FIGS. 4 and 5)
SUMMARY OF INVENTION
Technical Problem
[0005] In the conversional structure in which the mounting members are fastened on the lower sides of the front side frames, the support rigidity of the mounting members can be secured by only the rigidity of the lower walls of the front side frames on which the nuts are fixed, so that the entire rigidity of the front side frames is not actually utilized. Therefore, only the increase in the thickness of the lower walls of the front side frames can increase the support rigidity. That is, the capability of coping with a large load is limited.
[0006] In addition, Patent Literature 1 discloses only the case in which the mounting members are arranged above the front side frames, and does not mention the other portions. Therefore, although the structure disclosed in Patent Literature 1 locally enables a desirable deformation, the structure disclosed in Patent Literature 1 has a problem in load absorption over the entire length of the front side frames at the time of a crash.
[0007] The present invention has been made in view of the above problems, and provides a structure for a front section of a vehicle body enabling improvement in the support rigidity of mounting members arranged on the lower sides of front side frames.
Solution to Problem
[0008] The structure for a front section of a vehicle body according to the present invention is characterized in including: a pair of front side frames which are respectively arranged on right and left sides of the front section of the vehicle body, have a hollow structure, and extend in a front-rear direction; a subframe which is arranged between the pair of front side frames; a pair of first mounting members which are respectively arranged on the right and left sides below the pair of front side frames, and respectively support right and left ends of the subframe; first fixing members which fix the first mounting members to lower portions of the front side frames; first supporting members which are arranged inside the front side frames, and support the first fixing members; and reinforcing members which reinforce the vehicle body. In the above structure for the front section, the reinforcing members are joined to upper portions of the front side frames; and the first supporting members are fixed to inner surfaces of the front side frames below positions at which the reinforcing members are joined.
[0009] According to the above structure, the reinforcing members which reinforce the vehicle body are joined to the upper portions of the front side frames, and the first supporting members which support the first fixing members are fixed to the inner surfaces of the front side frames below the positions at which the reinforcing members are joined to the front side frames. Therefore, the support rigidity of the first networking members contributed by the front side frames is improved.
[0010] In addition, it is preferable that the reinforcing members extend in the vertical direction of the vehicle, and reinforce damper housings, in the structure.
[0011] According to the above structure, the support rigidity of the first mounting members can be improved by using the reinforce members which reinforce the damper housings.
[0012] Further, it is preferable that the first supporting members include a holding portion and a pair of partition portions, the holding portion hold the first fixing members, and the pair of partition portions be respectively arranged on front and rear sides of the holding portion, and be fixed to the inner surfaces of the front side frames.
[0013] According to the above structure, the first supporting members each include the holding portion (which holds the first fixing members) and the pair of partition portions (which are respectively arranged on the front and rear sides of the holding portion and fixed to the inner surfaces of the front side frames). Therefore, the support rigidity of the first supporting members is further improved compared with the case in which only a single partition portion is arranged. Thus, the front side frames can be deformed to intended directions. In addition, since the extent of overlap of the reinforcing members and the first mounting members in the vertical direction increases, the support rigidity of the first mounting members is further improved.
[0014] Furthermore, it is preferable that the structure for a front section of a vehicle body according to the present invention further include: second mounting members which are arranged above the front side frames, and support a power unit; second fixing members which fix the second mounting members to upper portions of the front side frames; and second supporting members which are arranged inside the front side frames, and support the second fixing members; where each of the first supporting members and the second supporting members includes a partition portion, which extends across an inner space in the front side frames in the vehicle width direction, and the partition portion is fixed to an inner surface of the front side frames with an individually predetermined inclination angle with respect to a direction in which the front side frames extend.
[0015] According to the above structure, the partition portions in the first supporting members and the second supporting members are fixed to the inner surfaces of the front side frames with individually predetermined inclination angles with respect to the direction in which the front side frames extend, such that the front side frames appropriately deform when a crash occurs. Thus, the load at the time of a crash can be absorbed by appropriately deforming the front side frames in their entire length when the crash occurs.
[0016] Moreover, it is preferable that the partition portions in the first supporting members and the partition portions in the second supporting members be fixed to the inner surfaces of the front side frames with inclination angles, which are set such that the partition portions in the first supporting members and the partition portions in the second supporting members are arranged nonparallel to each other in plan view.
[0017] According to the above structure, the inclination angles of the partition portions in the first supporting members and the partition portions in the second supporting members are set such that the partition portions in the first supporting members and the partition portions in the second supporting members are arranged nonparallel to each other in plan view. Therefore, when a crash occurs, the front side frames deform such that the front side frames project toward the narrower side of the nonparallel arrangement. Thus, the load can be absorbed by appropriately deforming the front side frames.
Advantageous Effect of Invention
[0018] According to the present invention, it is possible to provide a structure for a front section of a vehicle body enabling improvement in the support rigidity of mounting members arranged on the lower sides of front side frames.
BRIEF DESCRIPTION OF THE DRAWINGS
[0019] FIG. 1 is a perspective view of a structure of a front section of a vehicle body according to a first embodiment.
[0020] FIG. 2 is an enlarged perspective view of a portion connecting a front side frame and a subframe.
[0021] FIG. 3A is an upper front right perspective view of a first supporting member on the left side, and FIG. 3B is an upper rear left perspective view of the first supporting member on the left side.
[0022] FIG. 4 is a lower front left perspective view of a connection of the front side frame on the left side and a reinforcing member.
[0023] FIG. 5 is a plan view of the front side frame on the left side.
[0024] FIG. 6 is an upper front right perspective view of a first supporting member in a variation.
[0025] FIG. 7 is a lower right perspective view of the first supporting member in the variation.
DESCRIPTION OF EMBODIMENTS
[0026] The first embodiment of the present invention is explained with reference to FIGS. 1 to 5 in detail. In the explanations, identical elements respectively are referred to by identical numbers, and the same explanations are not repeated. In the following explanations, the front, rear, right, left, up, and down directions are based on the driver's position, and the vehicle width direction is the right-left (lateral) direction.
[0027] FIG. 1 is a perspective view of a structure of a front section of a vehicle body according to the first embodiment. FIG. 2 is an enlarged perspective view of a portion connecting a front side frame and a subframe. FIG. 3 A is an upper front right perspective view of a first supporting member on the left side, and FIG. 3B is an upper rear left perspective view of the first supporting member on the left side. FIG. 4 is a lower front left perspective view of a connection of the front side frame on the left side and a reinforcing member. FIG. 5 is a plan view of the front side frame on the left side. For convenience of illustration, FIGS. 2 and 4 are partially cutaway diagrams of the front side frame.
[0028] As illustrated in FIGS. 1 and 2 , the vehicle C having the front-section structure 1 of the vehicle body is an automobile having a power-source mounting room MR in the front section of the vehicle body, for example, an FF (front-engine, front-wheel drive), FR (front-engine, rear-wheel drive), or four-wheel drive car or the like. The model and type of the automobile is not specifically limited as long as a power unit P (illustrated in FIG. 5 ) such as an engine, a transmission, or an electric motor is installed as a power source for the driving wheels in the automobile.
[0029] The front-section structure 1 forms the front section of the vehicle C, and is constituted mainly by a pair of front side frames 2 , a subframe 3 , a pair of first mounting members 4 , first fixing members 5 (illustrated in FIG. 2 ), first supporting members 6 (illustrated in FIG. 2 ), a pair of damper housings 7 , and reinforcing members 8 . The pair of front side frames 2 are arranged on the right and left sides of the power-source mounting room MR to extend in the front-rear direction. The subframe 3 is arranged between the damper housings 7 arranged on the right and left sides. The first mounting members 4 are respectively arranged below the front side frames 2 . The first mounting members 4 are fixed to the front side frames 2 with the first fixing members 5 . The first supporting members 6 support the first fixing members 5 . The damper housings 7 enclose damper devices (not shown) for the front wheels. The reinforcing members 8 respectively reinforce the damper housings 7 .
[0030] In addition, the front-section structure 1 further includes a pair of upper members 11 , a pair of lower members 12 , a dashboard 13 , and a front bulk head 14 . The upper members 11 are arranged outside and above the front side frames 2 on the right and left sides to extend in the front-rear direction. The lower members 12 arranged on the right and left sides extend from the middle portions of the upper members 11 toward a forward down direction. The dashboard 13 separates the power-source mounting room MR and the vehicle interior R. The front bulk head 14 is arranged on the front side of the power-source mounting room MR. The front ends of the lower members 12 are connected to the front ends of the front side frames 2 via connection members 17 .
[0031] Further, since the front-section structure 1 according to the present embodiment is a bilaterally symmetric structure, only the left side of the vehicle C is explained below, and explanation on the structure on the right side is omitted. Furthermore, in the following explanations, the power-source mounting room MR side may be referred to as the inner side of the vehicle, and the side opposite to the power-source mounting room MR may be referred to as the outer side of the vehicle.
[0032] Each front side frame 2 is a frame member having a hollow shape, and has a function of absorbing shocks by being crushed in the front-rear direction in a bellows-like manner when the vehicle crashes. As illustrated in FIG. 2 , the front side frame 2 is formed to be a square tube-like member having a closed cross section, by joining an inner member 21 and an outer member 22 . The inner member 21 has a hat-like cross section and includes an upper wall 2 a , a lower wall 2 b , and an inner wall 2 c . The outer member 22 has a planar shape and constitutes an outer wall 2 d . In addition, the rear end of the front side frame 2 is bent downward and connected to a floor frame 16 below the dashboard 13 . The front end of the front side frame 2 is connected to the front bulk head 14 (as illustrated in FIG. 1 ). Further, the front side frame 2 contains therein the first supporting member 6 and two second supporting members 9 A and 9 B, where the first supporting member 6 is arranged for mounting the first mounting member 4 , and the second supporting members 9 A and 9 B are arranged for mounting second mounting members M 1 and M 2 (illustrated in FIG. 5 ). The first supporting member 6 and the second supporting members 9 A and 9 B are explained later.
[0033] Referring back to FIG. 1 , the subframe 3 is a member which supports the power unit P (illustrated in FIG. 5 ) from the lower side. The subframe 3 includes a body portion 31 and a plurality of arm portions 32 , 33 , and 34 , where the plurality of arm portions 32 , 33 , and 34 extend from the body portion 31 . (Although only the left side is illustrated, the subframe 3 according to the present embodiment has six arm portions in total.) Specifically, the arm portions 32 on the right and left sides extend rightward and leftward from the body portion 31 , and are connected to the front side frames 2 via the first mounting members 4 . The arm portions 33 on the right and left sides extend forward from the body portion 31 , and are connected to the front bulk head 14 . The arm portions 34 on the right and left sides extend rearward from the body portion 31 , and are connected to the floor frame 16 .
[0034] The damper housings 7 , as portions of the vehicle body, are portions which receive the damper devices (not shown) arranged for absorbing shocks from the front wheels. The side surfaces of the damper housings 7 are bent to have approximately an arched shape convex to the power-source mounting room MR side. The bottom end 7 a of each damper housing 7 is connected to one of the front side frames 2 , and the top 7 b end of the damper housing 7 is connected to one of the upper members 11 . In addition, a strut tower bar 15 is arranged to bridge the damper housings 7 on the right and left sides.
[0035] The reinforcing members 8 are concavely grooved members which are attached to the side surfaces of the damper housings 7 . As illustrated in FIGS. 2 and 4 , the reinforcing members 8 are arranged to extend in the vertical direction in such a manner that the opening of a concave groove 81 faces the damper housing 7 side. Each reinforcing member 8 includes a pair of first flange portions 82 and a second flange portion 83 . The first flange portions 82 are arranged along the concave groove 81 , and the second flange portion 83 is arranged at the bottom end. Specifically, the first flange portions 82 are fixed to one of the damper housings 7 by welding, and the second flange portion 83 is fixed to the upper wall 2 a and the inner wall 2 c of one of the front side frames 2 by welding. Therefore, a closed cross section is formed with the reinforcing member 8 and the damper housing 7 , so that the strength and rigidity of the vehicle body are improved. In the present embodiment, each reinforcing member 8 is connected to the position of one of the front side frames 2 at which the rear end side of the front side frame 2 begins to bend from the front end side.
[0036] As illustrated in FIG. 2 , the first mounting members 4 are members which support the arm portions 32 (extending rightward and leftward from the body portion 31 of the subframe 3 ), and arranged below the front side frames 2 . Each first mounting member 4 is fastened to the first supporting member 6 in one of the front side frames 2 with the first fixing member 5 such as a bolt which is inserted into the front side frame 2 through the first mounting member 4 from the lower side of the first mounting member 4 . In addition, the first mounting member 4 is fastened to the subframe 3 with two bolts inserted into the first mounting member 4 in the horizontal direction through one of the arm portions 32 of the subframe 3 (which extend rightward and leftward).
[0037] As illustrated in FIGS. 2 to 5 , the first supporting members 6 are members which support the aforementioned first fixing members 5 , and arranged inside the front side frames 2 . Each first supporting member 6 includes a holding portion 61 and a partition portion 62 . The holding portion 61 has a cylindrical shape, and the first fixing member 5 is inserted into the holding portion 61 . The partition portion 62 is arranged so as to extend across the inside of each front side frame 2 in the vehicle width direction.
[0038] As illustrated in FIGS. 3A and 3B , a female screw for holding the bolt as the first fixing member 5 is formed on an inner space 61 a of the holding portion 61 . In addition, a flange portion 61 b which extends outward in the radial direction is arranged at the bottom portion of the holding portion 61 . The flange portion 61 b is in contact with the lower wall 2 b of the front side frame 2 . Further, a through-hole 2 e for inserting the first fixing member 5 is formed in the lower wall 2 b in the front side frame 2 at the position corresponding to the hollow in the holding portion 61 (as illustrated in FIG. 4 ).
[0039] The partition portion 62 is a wall-like member which separates the inner space of the front side frame 2 into front and rear sides. The partition portion 62 includes a partition body 62 a , a concave portion 62 b , an upper flange 62 c , a lower flange 62 d , an inner flange 62 e , and an outer flange 62 f . The concave portion 62 b is arranged at approximately the center of the partition body 62 a to extend in the vertical direction. The upper flange 62 c , the lower flange 62 d , the inner flange 62 e , and the outer flange 62 f respectively extend from the upper end, the lower end, and the lateral (outer and inner) ends of the partition body 62 a . The holding portion 61 is fitted into the concave portion 62 b and fixed by welding. The upper flange 62 c and the outer flange 62 f extend forward from the partition body 62 a . The lower flange 62 d and the inner flange 62 e extend rearward from the partition body 62 a . The upper flange 62 c is fixed to the inner surface of the upper wall 2 a of the front side frame 2 by welding, and the lower flange 62 d is fixed to the inner surface of the lower wall 2 b of the front side frame 2 by welding. The inner flange 62 e is fixed to the inner surface of the inner wall 2 c of the front side frame 2 by welding, and the outer flange 62 f is fixed to the inner surface of the outer wall 2 d of the front side frame 2 by welding. The bottom end 62 g of the outer flange 62 f is arranged to extend to the level below the partition body 62 a and the lower flange 62 d , and held between the inner member 21 and the outer member 22 (constituting the front side frame 2 ), as illustrated in FIGS. 2 and 4 .
[0040] As illustrated in FIGS. 2 and 4 , the first supporting member 6 is fixed to the inner surface of the front side frame 2 below the position at which the reinforcing member 8 is joined to the front side frame 2 . In the present embodiment, a portion of the upper flange 62 c of the first supporting member 6 is arranged directly under the second flange portion 83 of the reinforcing member 8 , and the other portions are arranged below the second flange portion 83 . However, the arrangement of the first supporting member 6 is not limited to the arrangement explained above. Alternatively, it is possible to arrange the entire first supporting member 6 directly under the position at which the reinforcing member 8 is joined to the front side frame 2 .
[0041] Further, as illustrated in FIG. 5 , the partition portion 62 of the first supporting member 6 is arranged diagonal to the direction in which the front side frame 2 extends (and to the lateral direction), in such a manner that the outer flange 62 f is located on the front side of the inner flange 62 e.
[0042] As illustrated in FIGS. 2 and 5 , the second support members 9 A and 9 B are members for fixing the second mounting members M 1 and M 2 to the front side frame 2 , where the second mounting members M 1 and M 2 support an upper portion of the power unit P, which is mounted on the subframe 3 . One 9 A of the second support members is arranged inside the front side frame 2 on the front side of the first supporting member 6 . The other 9 B of the second support members is arranged inside the front side frame 2 on the front side of the second support member 9 A. In addition, the second mounting members M 1 and M 2 are fastened to the upper wall 2 a of the front side frame 2 with bolts as second fixing members 5 A (as illustrated in FIG. 2 , in which only the second support member 5 A on the second supporting member 9 B side is illustrated).
[0043] As illustrated in FIG. 2 , the second supporting members 9 A and 9 B each have a holding portion 91 and a partition portion 92 . The holding portion 91 has a cylindrical shape, and the second fixing member 5 A is inserted into the holding portion 91 . The partition portion 92 is arranged to extend across the inside of the front side frame 2 in the vehicle width direction. The holding portion 91 and the partition portion 92 are fixed by welding. A female screw is formed around an inner space 91 a of the holding portion 91 . An inner flange 92 a is formed at an end of the partition portion 92 on the inner side of the vehicle (on the right side in FIG. 2 ), and fixed to the inner surface of the inner wall 2 c of the front side frame 2 . An outer flange 92 b is formed at an end of the partition portion 92 on the outer side of the vehicle (on the left side in FIG. 2 ), and fixed to the inner surface of the outer wall 2 d of the front side frame 2 .
[0044] As illustrated in FIG. 5 , the partition portion 92 of the second supporting member 9 A is arranged diagonal to the direction in which the front side frame 2 extends (and to the lateral direction), in such a manner that the inner flange 92 a is located on the front side of the outer flange 92 b . Thus, the first supporting member 6 and the second support member 9 A are arranged nonparallel to each other in such a manner that the distance between the first supporting member 6 and the second support member 9 A is narrowed toward the outer side of the vehicle in plan view.
[0045] In addition, the partition portion 92 of the other second supporting member 9 B is arranged diagonal to the direction in which the front side frame 2 extends (and to the lateral direction), in such a manner that the outer flange 92 b is located on the front side of the inner flange 92 a . Thus, the second support member 9 A and the second support member 9 B are arranged nonparallel to each other in such a manner that the distance between the second support member 9 A and the second support member 9 B is narrowed toward the inner side of the vehicle in plan view.
[0046] The front-section structure 1 according to the present embodiment is constructed as explained above. Next, the operations and the advantageous effect of the front-section structure 1 are explained below.
[0047] In the front-section structure 1 according to the present embodiment, the reinforcing members 8 reinforcing the damper housings 7 constituting the vehicle body are joined to the upper walls 2 a of the front side frames 2 , and the first supporting members 6 supporting the first fixing members 5 are fixed to the inner surfaces of the front side frames 2 , respectively, below the positions at which the reinforcing members 8 are joined to the front side frames 2 . Therefore, the support rigidity of the first mounting members 4 contributed by the front side frames 2 is improved. That is, since the reinforcing members 8 are joined to the front side frames 2 in the vicinities of the positions at which the first supporting members 6 are joined to the front side frames 2 , the rigidity is improved in the vicinities of the joined positions. Therefore, deformation of the frame which can be caused by the force inputted from the tire side can be suppressed, and resultantly the support rigidity of the first mounting members 4 is improved.
[0048] In addition, according to the above structure, the support rigidity of the first mounting members 4 can be improved by use of the reinforcing members 8 which support the damper housings 7 . Therefore, the number of parts can be reduced, and the manufacturing is facilitated.
[0049] Further, the support rigidity of the first mounting members 4 can be changed by only changing the structures of the first supporting members 6 (e.g., the length of the holding portion 61 or the thickness of the partition portion 62 ) without changing the structure of the front side frames 2 . Therefore, various types of vehicles receiving different input loads can be coped with, and the front side frames 2 can be used in common.
[0050] Furthermore, since, in the front-section structure 1 according to the present invention, the partition portion 92 of the second support member 9 A and the partition portion 62 of the first supporting member 6 are fixed, nonparallel to each other, to the inner surfaces of each front side frame 2 in such a manner that the distance between the partition portion 92 and the partition portion 62 is narrowed toward one side in plan view, the load at the time of a crash can be absorbed by appropriately deforming the front side frames 2 to project toward the side on which the distance between the partition portion 92 and the partition portion 62 is narrower (i.e., the outer side in the present embodiment).
[0051] On the other hand, since the second support member 9 A and the second support member 9 B are arranged nonparallel to each other in such a manner that the distance between the second support member 9 A and the second support member 9 B is narrowed toward the opposite side to the arrangement of the partition portion 92 and the partition portion 62 , the bending load can be stably generated. Therefore, the load at the time of a crash can be absorbed by appropriately deforming and folding the front side frames 2 in their entire length from the front side to the rear side.
[0052] Next, a variation of the first supporting member 6 is explained with reference to FIGS. 6 and 7 . FIG. 6 is a perspective view, viewed from the inner side of the vehicle, of a first supporting member in the variation, and FIG. 7 is a lower perspective view, viewed from the inner side of the vehicle, of the first supporting member in the variation. In FIGS. 6 and 7 , a portion of the front side frame 2 and the reinforcing member 8 are illustrated by virtual lines (two-dot chain lines) for convenience of illustration.
[0053] The first supporting members 6 A each include a holding portion 61 and a pair of partition portions 62 A and 62 B. The partition portions 62 A and 62 B are respectively arranged on the rear and front sides of the holding portion 61 . The holding portion 61 is fixed to the pair of partition portions 62 A and 62 B via a bracket 63 , which is arranged to bridge the partition portions 62 A and 62 B.
[0054] The rear-side partition portion 62 A is a wall-like portion which separates the inner space of the front side frame 2 on the rear side of the holding portion 61 , into the front and rear sides of the rear-side partition body 62 A. The rear-side partition portion 62 A includes a rear partition body 62 Aa, an upper flange 62 Ac, a lower flange 62 Ad, an inner flange 62 Ae, and an outer flange 62 Af. The upper flange 62 Ac, the lower flange 62 Ad, the inner flange 62 Ae, and the outer flange 62 Af respectively extend from the upper end, the lower end, and the lateral (outer and inner) ends of the rear partition body 62 Aa. The upper flange 62 Ac, the lower flange 62 Ad, and the inner flange 62 Ae extend rearward from the rear partition body 62 Aa. The outer flange 62 Af extends forward from the rear partition body 62 Aa. The upper flange 62 Ac, the lower flange 62 Ad, the inner flange 62 Ae, and the outer flange 62 Af are respectively fixed to the inner surfaces of the upper wall 2 a , the lower wall 2 b , the inner wall 2 c , and the outer wall 2 d of the front side frame 2 .
[0055] The front-side partition portion 62 B is a wall-like portion which separates the inner space of the front side frame 2 on the front side of the holding portion 61 , into the front and rear sides of the front-side partition portion 62 B. The front-side partition portion 62 B includes a front partition portion 62 Ba, an upper flange 62 Bc, a lower flange 62 Bd, an inner flange 62 Be, and an outer flange 62 Bf. The upper flange 62 Bc, the lower flange 62 Bd, the inner flange 62 Be, and the outer flange 62 Bf respectively extend from the upper end, the lower end, and the lateral (outer and inner) ends of the front partition portion 62 Ba. The upper flange 62 Bc, the lower flange 62 Bd, and the inner flange 62 Be extend forward from the front partition portion 62 Ba. The outer flange 62 Bf extends rearward from the front partition portion 62 Ba. The upper flange 62 Bc, the lower flange 62 Bd, the inner flange 62 Be, and the outer flange 62 Bf are respectively fixed to the inner surfaces of the upper wall 2 a , the lower wall 2 b , the inner wall 2 c , and the outer wall 2 d of the front side frame 2 .
[0056] In addition, in the above variation, the outer flange 62 Af in the rear-side partition portion 62 and the outer flange 62 Bf in the front-side partition portion 62 B are continuously formed. In other words, the pair of partition portions 62 A and 62 B is formed with a groove-like member in which the outer flange 62 Af and the outer flange 62 Bf constitute a bottom wall, and the rear partition body 62 Aa and the rear partition body 62 Ba constitute an integrated side wall.
[0057] As illustrated in FIGS. 6 and 7 , the first supporting member 6 A according to the above variation is arranged below the position at which the reinforcing member 8 is joined to the front side frame 2 . Specifically, the entire first supporting member 6 A is arranged directly under the reinforcing member 8 .
[0058] In the above structure, each first supporting member 6 A according to the variation includes the holding portion 61 (which holds the first fixing member 5 ) and the pair of partition portions 62 A and 62 B (which are respectively arranged on the rear and front sides of the holding portion 61 and fixed to the inner surface of the front side frame 2 ). Therefore, the support rigidity of the first mounting member 4 is further improved compared with the case where only the single partition portion 62 is arranged. Thus, the front side frame 2 can be deformed in intended directions with high reliability when a crash occurs. In addition, since the extent of overlap of the first mounting member 4 and the reinforcing member 8 in the vertical direction increases, the support rigidity of the first mounting member 4 is further improved.
[0059] Although the front-section structures 1 according to an embodiment are explained above in detail with respect to the drawings, the present invention is not limited to the explained embodiment, and the embodiment can be modified as needed without departing from the gist of the present invention.
[0060] For example, although the bolts are indicated as examples of the first fixing members 5 , the present invention is not limited to the use of bolts as the first fixing members 5 , and other fixing members such as rivets may be used as long as the joining strength is sufficient.
[0061] In the explained embodiment, the narrower side of the nonparallel arrangement of the first supporting member 6 and the second support member 9 A is directed to the outer side of the vehicle, and the narrower side of the nonparallel arrangement of the second support member 9 A and the second support member 9 B is directed to the inner side of the vehicle. Alternatively, the narrower sides in the above arrangements may be directed to the respectively opposite directions.
[0062] In the explained embodiment, the pair of partition portions 62 A and 62 B in each first supporting member 6 A is realized by the single member, the present invention is not limited to such a structure, and the partition portions 62 A and 62 B may be realized by individually separate members.
LIST OF REFERENCE SIGNS
[0063] 1 : Front-section Structure 2 : Front Side Frame 3 : Subframe 4 : First Mounting Member 5 : First Fixing Member 6 : First Supporting Member 61 : Holding Portion 62 : Partition portion 7 : Damper Housing (Vehicle Body) 8 : Reinforcing Members 9 A, 9 B: Second Supporting Members
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A structure for the front section of a vehicle body is provided with: a pair of left and right front side frames; a sub-frame which is disposed between the front side frames; a pair of left and right first mount members which are disposed below the front side frames; first affixation members which affix the first mount members to the lower sections of the front side frames; first support members which are provided within the front side frames and which support the first affixation members; and reinforcement members which reinforce damper housings. The reinforcement members are joined to the upper sections of the front side frames. The first support members are affixed to the inner surfaces of the front side frames at positions below the portions to which the reinforcement members are joined.
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This application claims the benefit of the U.S. Provisional Patent Application No. 60/860,217, filed on Nov. 21, 2006.
FIELD OF THE INVENTION
The present invention relates to an apparatus useful to probe a solution gradient. In particular, the present invention relates to an apparatus comprising a probe adapted to generate a gradient profile of a density gradient independent of fractionation.
BACKGROUND OF THE INVENTION
Solution gradients or density gradients are utilized in biochemical research to separate macromolecules such as proteins, DNA and RNA, and larger aggregates such as viruses and cells. More recently, density gradient centrifugation has found application in the field of nanotechnology. Researchers at Northwestern University have used gradients to separate and purify different classes of carbon nanotubes.
Solution gradients usually utilize a solute of varying concentrations to aid in the separation of particles. Examples of appropriate solutes are: sucrose, glycerol, CsCl, Optiprep™, Percoll™, ficoll, metrizamide, Nycodenz™ and/or sodium acetate. Particles are separated during centrifugation either by their velocity of sedimentation, or by their density if there is an isopycnic point within the solution column in the tube. Faster, or denser particles, respectively, will appear lower in the tube.
After the sample has been subjected into the appropriate density gradient in the centrifuge, the particles are recovered from the gradient for analysis. Fractionation methods and apparatus used to recover the sample in the gradient involve the transfer of the entire gradient or certain layers or bands of the solution gradient to other vessels. It is often desired to extract only desired bands from the solution gradient for electron microscopy, liquid scintillation or gel electrophoresis.
One of the earliest and simplest methods of fractionation is to pierce the bottom of the centrifuge tube with a fine bevelled needle and collect the drops of the solution gradient as it flows through the needle into a second vessel. The flow of the solution into the opening of the needle becomes conical. In other words, the particles directly in front of the needle opening and within a zone best described as an inverted cone above the needle are drawn into the needle opening before particles outside the cone. The resulting fractionation of different layers of the solution gradient significantly degrades the resolution achieved in the gradient.
Bottom puncture with side hole needles have also been used for fractionation. Side hole needles have a hole on each side of the needle tip. Side hole needles are more effective than the bevelled needle, but side hole needles also draw the solution into the needle in a conical fashion preventing high resolution of the fractionation.
One of the most common methods for fractionating solution gradients introduces a dense solution at the bottom of the centrifuge tube, which floats the gradient up to an inverted collection funnel placed on the top of the gradient. Some loss of resolution results from the retardation of particles near the tube wall during this upward movement, and at any but the slowest flow rates, the shallow collection cone fails to prevent the shallow collection cone fails to prevent the same cone-shaped extraction of liquid directly below the cone's central orifice experienced by the bevelled needle described above. The result is mixing of different layers in the gradient and the resultant loss of resolution.
These problems were addressed in U.S. Pat. No. 4,003,834 to Coombs, issued Jan. 18, 1977, an apparatus is disclosed for the fractionation of a solution gradient by displacement with a piston, and in U.S. Pat. No. 5,645,715 to Coombs issued 1995 which discloses a piston collection tip with a unique trumpet shape collection face. The use of a piston to displace the gradient from the top down solves the problem of particles adhering to the wall during the upward movement of the entire gradient since the gradient remains stationary until it is displaced by the downward movement of the piston. The trumpet tip prevents the cone-shaped mixing by gradually compressing horizontal bands into thin vertical columns prior to collection. Tubing carrying both air and rinse is disposed within the piston to allow for cleaning of the collection tubing, further improving resolution by preventing cross contamination between fractions. Pumping air into the piston tip transfers any solution gradient left in the tubing to a second vessel.
U.S. Pat. No. 4,003,834 also provides a means for visualizing bands of particles large enough to scatter visible light. However, many particles of interest are too small to scatter visible light or are present at too low a concentration to be detected. Since the nucleic acids and proteins found in these particles absorb UV light in the 260-280 nm range, it is the current practice to detect bands of these particles by passing the gradient outflow through a UV flow cell as is frequently done in HPLC and FPLC. The UV gradient profile obtained by the flow cell can be used as a diagnostic tool in its own right; however, in this application, the profile is generated as the gradient is being removed from the centrifuge tube.
There are two potential problems with this type of UV-based fractionation. Firstly, it is difficult to accurately and reproducibly identify the beginning and end of UV absorbance peaks (bands) in the profile as it is being generated. Secondly, unless the user manually interrupts the flow at the start and end of each peak, the fraction collector typically used to separate the gradient outflow into discrete fractions is doing so at a constant time interval or rate of flow. Thus, there is no relationship between the peaks of absorbance and the fractions and this requires the user to scan a range of fractions to identify those containing the particles of interest. Some UV-based collection systems have “peak-picking” algorithms built into their software so that rapid changes in UV absorbance in the outflow trigger sample collection into a new vessel. While providing adequate separation of discrete peaks of particles, these devices have difficulty detecting and separating overlapping peaks or shoulders. Volume- or time-based fractionation of the UV-flow cell output is disrupted by peak-picking, so the overall sampling profile is then lost. Thus, one must choose between obtaining uniform size samples for analysis or isolating peaks, as they are mutually exclusive.
Certain inventions (i.e. U.S. Pat. Nos. 4,873,875; 6,479,239) have attempted to obtain a UV or fluorescent profile of the contents of a centrifuged gradient by vertically scanning the gradient with a beam of light from the outside of the tube. These have not seen widespread use because the only centrifuge tubes that can withstand the severe stress of ultracentrifugation (100,000-1,000,000×g) are made of a UV-absorbing plastic, effectively preventing the beam from penetrating the tube. Consequently, the only devices currently capable of producing a UV profile of a gradient are those which pass the gradient through a detached UV flow cell.
It would be desirable, thus, to develop a means of generating a gradient profile independent of fractionation that may be used as a guide to fractionation.
SUMMARY OF THE INVENTION
An apparatus has now been developed which is useful to obtain a profile of a density gradient. The apparatus comprises a probe adapted to obtain a gradient profile optically. The probe advantageously causes minimal disturbance of the gradient and thereby provides a gradient profile of high resolution.
Thus, in one embodiment, an apparatus is provided adapted to obtain a gradient profile. The apparatus includes a light source, a probe comprising a first probe needle actuatable to extend into a tube containing the gradient, said probe being in communication with the light source and comprising a first light-transmitting means to receive light from the light source and transmit light through the gradient as the probe needle extends into the gradient, and a second light-transmitting means to receive light transmitted by said first light-transmitting means and transmit the received light to a signal-producing means.
In another aspect of the present invention, there is provided a fractionation apparatus adapted to obtain a gradient profile of a density gradient independently of fractionation. The fractionation apparatus comprises:
a light source; a probe comprising a first probe needle actuatable to extend into a tube containing the gradient, said probe being in communication with the light source and comprising a first light-transmitting means to receive light from the light source and transmit light through the gradient as the probe needle extends into the gradient, and a second light-transmitting means to receive light transmitted by said first light-transmitted means and transmit the received light; a signal-producing means positioned to receive light from the second light-transmitting means, wherein said signal-producing means translates the received light into a recordable signal to produce a profile of the gradient; and a piston actuatable to extend into the gradient-containing tube and to fractionate the gradient according to the sample profile;
wherein the probe and piston are moveable between a resting position wherein the probe and piston are clear of the gradient tube, a probing position wherein the probe is in a gradient access position and a fractionating position wherein the piston is in a gradient access position, said probe and piston being independently actuatable.
In another aspect of the present invention, a method of fractionating a gradient is provided comprising:
i) determining the profile of a gradient; ii) selecting a fractionation plan according to the profile; and ii) executing fractionation of the gradient according to the plan.
These and other aspects of the present invention will become apparent by reference to the detailed description, and the drawings in which:
BRIEF DESCRIPTION OF THE DRAWINGS
FIG. 1 is a perspective view of an apparatus according to an aspect of the invention;
FIG. 2 is a side view of the fractionation portion of an apparatus of FIG. 1 and an exploded view (A) of the valves therein;
FIG. 3 is a perspective view of the probe portion of an apparatus of FIG. 1 and exploded views of the tip of the probe needle (A) and light source/photodetector (B);
FIG. 4 is a top view illustrating the arc of movement of a probe, piston and actuator of an apparatus of FIG. 1 ;
FIG. 5 illustrates the first probing position (A/B) and second fractionating position (C/D) of the apparatus of FIG. 1 ;
FIG. 6 illustrates an embodiment of the invention;
FIG. 7 illustrates an embodiment of the invention;
FIG. 8 illustrates an embodiment of the invention;
FIG. 9 illustrates an embodiment of the invention
FIG. 10 illustrates different geometries of the probe needle tip;
FIG. 11 illustrates the output signal including zone marking of an apparatus of FIG. 1 ; and
FIG. 12 illustrates the probe (B) and piston (C) of an embodiment of the invention extended within a sample tube.
DETAILED DESCRIPTION OF THE INVENTION
A fractionation apparatus 100 is provided as shown in FIG. 1 comprising a fractionation or collection portion 110 and a probe portion 120 useful to generate a profile of a density gradient that can be converted into a fractionation run. The fractionation portion 110 of the apparatus 100 generally corresponds with that described in U.S. Pat. No. 5,645,715, the relevant portion of which (found in columns 3-7) is incorporated herein by reference. As described, and as generally shown in FIG. 2 , the fractionation portion 110 comprises a piston 10 having an internal passageway or valve 12 , and inserted within the valve 12 are a collection tube 14 , an air tube 16 and a rinse tube 18 . Mounted below the valve 12 on the end of the piston 10 is a collection tip 19 , which may optionally be an interchangeable collection tip as described in U.S. Pat. No. 5,645,715.
As one of skill in the art will appreciate, the configuration described in U.S. Pat. No. 5,645,715 may be modified as shown in FIG. 2(A) to increase efficiency. For example, the valve 12 may incorporate two one-way valves to permit the rinsing and drying of the sample tubing without disturbing the gradient. The first one-way valve is a ball valve 3 which prevents backflow of air or rinse into the gradient, while the second one-way valve is a rubber duckbill 4 valve which prevents backflow of rinse and gradient into the air tubing. Backflow of air and gradient into the rinse line is prevented by a rubber duckbill one-way valve mounted in the tubing between the rinse pump and the piston.
Referring to FIGS. 1 and 3 , the fractionation apparatus 100 of an embodiment of the invention comprises a probe portion 120 situated adjacent to the piston 10 . The probe portion 120 comprises a probe 20 . The probe 20 consists of at least one hollow probe needle 22 which is open at both ends. The probe needle 22 has an upper end 24 , which is secured to a mounting block 27 , and a lower end 26 . The probe 20 and piston 10 are both mounted on a platform or swing arm 17 . The swing arm 17 is mounted onto an actuator 15 . As shown in FIG. 4 , the center of the piston 10 and the center of the probe needle(s) 22 are positioned on the same radial arc 21 . The arc is centered on the actuator 15 such that rotation of the actuator 15 positions either the probe 20 or the piston 10 over the gradient tube holder 50 ( FIG. 1 ) of the apparatus 100 . Thus, as shown in FIG. 5 , the swing arm 17 and actuator 15 are moveable between a fully retracted resting position in which both the piston 10 and probe 20 are clear of a tube holder 50 which holds the gradient, a first or probe position in which the probe 20 is in position centered above tube holder 50 ( FIG. 5A )) and a second or fractionating position in which the piston 10 is positioned centered above the tube holder 50 ( FIG. 5(C) ).
The actuator 15 also functions to lower each of the probe 20 and piston 10 , respectively, when in position above the tube holder 50 , into a sample gradient tube 13 as illustrated in FIG. 9 . The actuator 15 may be manual, as illustrated and described in U.S. Pat. No. 4,003,834, the relevant disclosure of which (e.g. columns 3-7) is incorporated herein by reference. Alternatively, the apparatus may be fully automated by incorporating a computer to drive a stepper motor to rotate an acme screw which raises and lowers the actuator 15 , providing means for precisely determining the position and velocity of both the piston 10 and the probe 20 . This ensures that the extension of the probe 20 into the sample is conducted at a constant velocity such that each data point in the UV profile is coupled with its precise position in the gradient.
The probe needle 22 contains fiber optic bundles 28 . In one embodiment, as illustrated in FIG. 6 , the fibre optic bundles 28 within the probe needle 22 include a mixed and randomized fibre optic transmitting bundle 29 and a fibre optic receiving bundle 30 ( FIG. 6B ), each of which extend the length of the probe needle 22 . The transmitting bundle 29 is connected to a suitable light source 32 , such as an LED emitting in a selected wavelength range. For detection of UV-absorbing particles, the transmitting bundle 29 connects to a suitable UV source such as an ultra-violet light emitting diode (UV LED). In alternative embodiments, the light source may be an LED emitting in the visible range. The light source 32 is mounted onto the mounting block 27 . A photodetector 42 is also mounted on the mounted block 27 approximately adjacent to the light source 32 ( FIG. 6A ).
As one of skill in the art will appreciate, each fibre optic bundle will incorporate fibres manufactured of material appropriate for the transmission of the wavelength of the light emitted from the light source 32 . For example, if the light source 32 emits in the UV range from 250 to 350 nm, quartz (fused silica) fibres may be used. The number and diameter of the fibres in the fibre optic bundle is optimized empirically to provide the highest signal to noise ratio and the highest resolution in a given application. For example, in certain embodiments, such as those illustrated in FIGS. 6-9 , 80 fibres with 0.1 m diameter are utilized. In these embodiments, the choice of 80 fibres was based on the fact that fewer fibres produce a weaker signal while more fibres require a larger diameter needle and result in greater disturbance during the probing of the gradient. In certain embodiments, such as those illustrated in FIGS. 6 , 8 and 9 , the fibres are split into two independent bundles, a transmitting bundle 29 and a receiving bundle 30 .
A reflection means 34 is permanently attached to the bottom end 26 of the probe needle 22 which functions to reflect a beam of light received from the light source 32 , conducted the length of the probe needle 22 by the transmitting bundle 29 , into the gradient. The reflecting means 34 reflects the light beam into the gradient towards a second reflection means 36 , for example, at a 90° angle to the probe needle 22 . The reflected beam exits the needle 22 , travels a gap 38 through the gradient and is then deflected by the second reflection means 36 back along the same plane towards the first reflection means 34 , e.g. at an angle of 180°. The gap 38 between the first and second reflection means 34 , 36 is sufficient to render a suitably accurate reading of the gradient. The first and second reflection means 34 , 36 may be any means capable of reflecting the light beam at the required angle. In this embodiment, for example, a prism is appropriate for use as the first reflection means 34 having a 45° reflecting angle. While many sizes of prism will be suitable, the prism exemplified in one embodiment has cross section dimensions of: 1.0 mm.×1.0 mm on both 90° faces and 1.4 mm along the hypotenuse reflector surface. The length of the prism matches the length of the end of the needle, e.g. 2.9 mm.
The second reflection means 36 is affixed to a support 45 sufficient to position it appropriately from the probe needle 22 . The support 45 may be a support needle (as shown in FIG. 3 ) generally aligned parallel to the probe needle 22 such that it is appropriately spaced from the needle 22 to provide gap 38 . Generally, the gap 38 between the first and second reflection means 34 , 36 is in the range of 1-10 mm. Since an increase in gap size will result in increased absorbance, and a decrease in gap size will result in a stronger signal, the gap 38 between the first and second reflection means 34 , 36 may be adjusted in order to maximize resolution in view of the variability among gradients. The support needle 45 containing the reflecting means 36 is shown mounted onto mounting block 27 such that it will co-extend into the gradient simultaneously with the probe needle 22 on actuation of actuator 15 .
The second reflecting means 36 comprises a 180° reflecting angle and may be, for example, a planar mirror. Its minimum dimensions are the dimensions of the beam it is to reflect, for example, 0.3×2.6 mm, but may, of course be larger to reduce the stringency of its positioning on the support needle 45 . As indicated above, the second reflection means 36 is positioned to reflect the incident beam from the probe needle 22 back and into the receiving fibres 30 within the end of the probe needle 22 .
As shown in FIG. 10 , the geometry of the probe needle end 26 has a significant impact on the resolving power of the probe needle 22 . In one example, the transmitting/receiving fibre bundle 29 , 30 may be circular 48 ( FIG. 10A ) at the bottom end 26 of the probe needle 22 , producing a cylindrical beam of light 49 that is reflected by the first reflecting means 34 across the gap 38 to the second reflecting means 36 . The band of particles in the gradient 51 will first be detected when the bottom edge of the cylindrical beam 49 first encounters the band 61 . The band will be detected until the top edge of the beam 52 leaves the band, giving a total distance of detection 53 . If the probe needle 22 is flattened at its lower end 26 to a rectangular shape 54 ( FIG. 10B ), the light beam 55 crossing the gap 38 is much thinner, resulting in a smaller total distance of detection 56 and increased resolution. The dimensions of the rectangle are constrained by the number, diameter and arrangement of the fibers in the bundle. For example, using a bundle of 80 fibers generates a beam having 0.3×2.9 mm rectangular shape. If a single row of fibers is used in a flattened needle 57 ( FIG. 10C ), the thinnest beam of light 58 is produced and (theoretically) the smallest total distance of detection 59 . However, the amount of light available for detection is also much reduced (30% of the two other versions shown since the number of fibres is decreased), so the signal to noise ratio suffers. If the number of fibres remains the same as in the circular and rectangular examples (FIG. 10 A/B) ( 48 and 54 ), the end of the needle shown in FIG. 10C would be 8 mm across, giving a greater wetted surface area and producing more disturbance of the gradient during insertion and withdrawal of the probe. Thus, the dimensions of the end of the probe needle impact on both resolution and gradient disturbance, and require selection in order to provide an appropriate balance. Dimensions of 0.3 mm×2.9 mm represent an example of a suitable compromise between resolution and disturbance. While bands of particles in a gradient are occasionally 1 mm thick, most bands lie in the 2-5 mm range of thickness, so the 0.3 mm thickness produces a tolerable loss of resolution.
The required electronic circuitry 60 to send and receive the light signal is attached directly to the mounting block 27 (as shown in FIG. 3A ) to minimize the sensitivity of the photoreceptor to spurious electronic interference and vibration.
The light beam received and conducted by the receiving fibres 30 is transmitted for detection by a photodetector 42 as shown in FIG. 3 . One suitable photodetector for UV light is a 1 mm 2 SiC chip contained in a small can with a quartz window (JEC 1S, Boston Electronics, Boston, Mass.). Since the end of the receiving bundle 30 cannot be physically coupled to this chip, and since the light beam diverges at an angle of, for e.g., 17° after it leaves the upper end of the receiving bundle 30 the light beam is transmitted onto a set of condensor lenses 40 which collect and refocus the beam onto the SiC chip inside the can. An example of a suitable set of lenses consists of two plano convex lenses (01LQF005, f=10.0 mm, dia=5 mm, Melles Griot, Ontario, Canada) arranged as shown in the exploded view FIG. 3B .
The photodetector 42 translates the light beam into a recordable output such as current or voltage which is then digitized by a microprocessor 61 such as a Burr Brown microprocessor (DDC-112) and displayed on a display unit 44 , such as a monitor, which is connected to the control panel 43 ( FIG. 1 ). The absorbance values collected at regular user-determined intervals, for example, 10 data points/mm, are stored as a spreadsheet associated with the depth in the gradient from which they are taken. The display unit 44 functions in real-time to display the gradient UV absorbance profile throughout the depth of the gradient.
Using the real-time profile, the fractionation is planned by dividing the profile into fractionation zones and by further dividing each zone into a desired number of fractions. This can be accomplished using, for example, a rotary encoder with push switch 63 to move a vertical line cursor across the displayed profile, pressing it down to set the position of the various zones. To synchronize the probing and fractionation functions, both stages of analysis begin with the actuator 15 in its full up resting position where it contacts a limit switch. For each different size tube, for example Beckman's SW28, SW28.1, SW40, SW41, SW55, SW60 and TLS55, the precise vertical offset between the tip of the probe and the point of gradient capture inside the piston tip is determined empirically and stored in memory. Thus, the position of the cursor on the display can be precisely translated into a corresponding piston position during fractionation. Likewise, the position of each zone and the sub-fractions within each zone can readily be calculated. Once the plan has been set on the display, the computer converts the fractionation plan into a series of downward movements of the piston interrupted by a user-selected rinse protocol at the end of each fraction. The speed of the piston's movements is set automatically, but is user-adjustable, with 0.3 mm/sec being a typical speed.
In practice, a gradient profile is obtained using an apparatus according to an aspect of the invention by placing a gradient-containing tube 13 into the tube holder 50 . As shown in FIG. 5 , the probe 20 is swung into position above the tube and actuated to probe the sample. The probe and support needles ( 22 , 45 ) are simultaneously lowered into the gradient at a constant speed within the range of 0.1-6.0 mm/sec. As the needles extend into the gradient, light transmitted from the light source 32 is captured by the transmitting fibre optic bundle 29 and is conducted the length of the probe needle 22 to the bottom end 26 thereof where it is reflected at a 90° angle off of the first reflecting means 34 . The reflected light travels the gap 38 through the gradient and is reflected at a 180° angle off of the second reflecting means 36 . The reflected light re-travels the gap 38 , is reflected 90° by the first reflecting means 34 , is captured by the receiving fibre optic bundle 30 and is conducted the length of the probe needle 22 to the top end 24 thereof. The returning beam leaves the end of the receiving bundle and is captured by a set of condensor lenses 40 which refocus it for detection by the photodetector 42 . The photodetector 42 translates the light received into recordable output that may be displayed graphically, numerically or otherwise on a display unit 44 . Upon reaching the bottom of the sample tube, the needles are withdrawn automatically.
The planning stage involves using a combined rotary encoder+push switch 63 connected to the display unit 44 , for example, as is a standard feature of any oscilloscope, to move a vertical line cursor along the X-axis of the displayed gradient profile to set the various zones for fractionation. As the user sets each new zone along the profile, the user is prompted to set the number of fractions within that zone as illustrated in FIG. 11 . For example, the gradient may be a single zone divided into a number of equal fractions. Alternatively, the gradient may be divided into several zones with a variable number of fractions per zone. This latter mode permits the isolation of individual bands of particles in the gradient for further analysis.
Once the fractionation zones and fractions are selected, the piston 10 is swung into position over the gradient tube and the gradient is then fractionated automatically. The fractionation plan developed by the user in the previous stage is converted by the computer into a series of downward movements of the actuator 15 and piston 10 , interrupted by the insertion of brief bursts of rinses and air to expel sample left in the tubing and remove any cross contamination between fractions.
This profiling function of the probe 20 of the present apparatus 100 advantageously provides a means to view the sample gradient and particles of interest therein, and thus, a means to plan the fractionation of the gradient prior to the actual fractionation.
To this point, an embodiment is described in which the apparatus 100 comprises a dual needle probe ( 22 , 45 ) with one needle ( 22 ) containing both the sending and receiving light bundles ( 29 , 30 ) and the other support needle ( 45 ) having mounted thereon a second reflecting means ( 36 ) to deflect the beam reflected by the first reflecting means ( 34 ) from the transmitting bundle ( 29 ) back to the receiving bundle ( 30 ), thus effectively doubling the path length of the probe.
In another embodiment of the present invention, as shown in FIG. 7 , the probe 20 includes dual probe needles, a first transmitting probe needle 22 containing a transmitting fibre optic bundle 29 and a second receiving probe needle 23 containing a receiving fibre optic bundle 30 . Both bundles will contain an appropriate number of fibers to permit a maximum beam strength and sensitivity, for example, 80 fibres each. As set out above, the first and second probe needles are spaced by an adjustable gap 38 as shown in FIG. 7B . In this case, the first reflecting means 34 is attached to the bottom of the first probe needle 22 such that the light beam passing through the first probe needle 22 is reflected at a 90° angle through the gradient across gap 38 . The reflected light beam is received by the second reflecting means 36 which is attached to the bottom of the receiving probe needle 23 such that it reflects the incoming light beam at an angle of 90° to be received by the receiving fibre optic bundle 30 in the receiving probe needle 23 . As described, the receiving fibre optic bundle 30 carries the light beam to the top end of the second probe needle 23 where it is transmitted onto a set of lenses 40 for refocusing and then translation by a photodetector 42 to an output signal that forms the profile of the gradient ( FIG. 7A ). The fractionation plan and fractionation are then executed as described.
FIG. 8 illustrates another embodiment of the present invention, in which the apparatus 100 incorporates a dual wavelength probe. In this embodiment, the first transmitting probe needle 22 contains two fiber bundles of 40 fibers each. A first wavelength fibre bundle 29 a is in communication with a first LED light source 32 a that generates light at a first wavelength and a second wavelength fibre bundle 29 b is in communication with a second LED light source 32 b that generates light at a second wavelength ( FIG. 8A ). For example, in the case of UV light, the first light source may generate UV light at a wavelength of 260 nm for detection of nucleic acids, while the second light source may generate UV light at a wavelength of 280 nm for detection of proteins. The second receiving probe needle 23 contains a single receiving fibre optic bundle 30 of 80 fibers. In this embodiment, the first and second light sources 32 a, 32 b transmit light in alternating pulses, which are absorbed by the appropriate transmitting bundle, reflected by the first reflecting means 34 to the second reflecting means 36 , reflected by the second reflecting means 36 , received and transmitted by the receiving fibre optic bundle 30 in the second receiving probe needle 23 . The light received by the photodetector 42 at the top of the receiving needle 23 is sorted by wavelength into two data streams by the microprocessor 61 (e.g. Burr-Brown processor DDC-112), one for each wavelength, generating a dual wavelength profile at the output stage. The fractionation plan and fractionation are then executed as described.
A further embodiment of the present invention is illustrated in FIG. 9 . This embodiment comprises a single needle, dual bundle probe; however, rather than measuring the amount of light absorbed by particles in the gradient, this probe is designed to detect particles within the gradient or sample by fluorescence. In this embodiment, the single probe needle 22 houses both transmitting and receiving fibre optic bundles 29 , 30 consisting of, for example, 40 fibers each ( FIG. 9A ). The light source 32 transmits an excitation beam which is carried by the transmitting fibre optic bundle 29 and reflected into the gradient by the first reflecting means 34 attached at the bottom of the probe needle 22 as previously described. Particles of interest 39 within the solution are detected when they absorb light from the emitting bundle at an absorption wavelength and emit it back to the receiving bundle 30 at an emission wavelength ( FIG. 9B ). The returning light beam strikes the reflecting means 34 , is received by the receiving fibre optic bundle 30 and transmitted to the photodetector 42 for translation as an output signal. A narrow bandpass filter 47 placed between the two condensor lenses 40 in front of the photodetector 42 will prevent the emitted beam from reaching the photodetector 42 , as is standard practice in any commercial fluorometer. This configuration can detect particles by their natural fluorescence, by the enhanced fluorescence of a wide variety of commercial dyes that bind specifically to biological molecules of interest or by fluorescent dye-tagged antibodies. For example, viruses can be detected using a DNA-binding dye called PicoGreen (Molecular Probes, Invitrogen, USA) (for example, see “Quantitation of Adenovirus DNA and Virus Particles with the PicoGreen Fluorescent Dye, Murakami P.; McCaman M. T. Analytical Biochemistry, Volume 274, Number 2, October 1999, pp. 283-288”). The excitation light source for PicoGreen delivered by the transmitting bundle 29 is at 485 nm and the emission wavelength received by the receiving bundle 30 in the same probe needle 22 is 538 or 518 nm. These dyes offer sensitivity that is reportedly 10,000 times more sensitive than UV absorbance. Using these dyes converts this absorbance device into a fluorometer probe.
As will be appreciated by one of skill in the art, the present apparatus 100 may be modified to solely incorporate a probe portion 120 without a fractionation portion 110 as partially shown in FIG. 12B . Such a probing apparatus comprises the features detailed in the foregoing for the probing function of the apparatus and lacks those features necessary to conduct fractionation. Thus, in instances where the desired end product of a gradient-based analyses is the absorbance profile, an apparatus incorporating only a probe portion as described herein may be used.
Although the disclosure describes and illustrates the preferred embodiments of the invention, it is understood that the invention is not limited to these particular embodiments. Many variations and modifications will occur to those skilled in the art. For definition of the invention, reference is made to the appended claims.
References referred to herein are incorporated by reference.
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An apparatus adapted to obtain a profile of a density gradient sample independently of fractionation is provided. The apparatus includes a light source, a probe comprising a first probe needle actuatable to extend into a tube containing a sample, a first light-transmitting means to receive light from the light source and transmit light through the sample as the probe needle extends into the sample, a second light-transmitting means to receive light transmitted by the first light-transmitting means and transmit the received light to a signal-producing means capable of translating the received light into a recordable signal to produce a profile of the sample. The apparatus may additionally be adapted to fractionate the sample following generation of the gradient profile.
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FIELD
[0001] The present invention relates to protective collars, also known as veterinary restraints, for small animals and commonly called “Elizabethan collars” or “e-collars”. The collar is useful for preventing the animal from licking or biting wounds, or disrupting surgical stitches. The collar further prevents disruption of medications applied topically at the site of an injury, or surgical wound.
BACKGROUND
[0002] When wounded or when a diseased site is present, many animals, for example cats and dogs will instinctively lick or bite at the site of the injury or disease. Repeated licking typically results in slower healing and increased risk of infection. Where animals have undergone a surgical procedure, licking further risks disruption of sutures placed to keep the surgical wound closed while the healing process proceeds. Disruption of a surgical wound is highly undesirable as it subjects the animal to the risk of serious or even fatal internal infections. In any case where a medication is applied, the animal tends to lick it.
[0003] As a result, a variety of approaches have been developed to prevent animals from licking or otherwise disturbing wounds or a diseased or injured area while they are healing. For example, one common approach is to use a protective collar known as an “Elizabethan collar” or “E-collar” as they are sometimes called. These collars usually are formed from flexible but relatively rigid materials such as sheets of plastic or cardboard, and are provided in a range of sizes in order to accommodate animals of different size. The E-collar is wrapped around the animal's neck and then secured in place as a means by which to prevent the animal from contacting or otherwise disturbing a wound or site of application of a topical medicament.
[0004] One example is provided by U.S. Pat. No. 4,200,057 (Agar), which discloses a method of using a cone-shaped collar made of a semi-rigid material that when secured forms a cone around the animal's neck and which prevents the animal from contacting a region on the animal to which a substance has been applied topically. However, while commonly used, traditional E-collars suffer from a number of limitations that detract from their usefulness.
[0005] For example, as discussed above, these collars are usually fashioned from relatively rigid materials. Consequently they are not adapted to folding and take up significant space when on a store shelf, or when stored by an animal owner after purchase and between uses. In addition, the rigid material tends to be uncomfortable for the animal to wear and it can break if bent too far. The rigid materials typically used in E-collars also make it difficult for the animal to eat or drink or get through tight spaces, and the pet is jarred if it bumps into something straight-on. The rigid E-collars can scratch furniture, knock things over and hurt a person. Also, the noise of striking something or even brushing against something can cause stress for the pet.
[0006] It is well known in the art that animals dislike the application of the E-collar and will attempt to remove it. This results in increased stress to the animal, and if removed, obviates the utility of the collar to prevent contact of an injured area by the animal, prolonging healing time and increasing the risk of serious infection.
[0007] A variety of protective collars have been described, some based on the traditional E-collar design, and others using other designs. For example, U.S. Pat. No. 5,012,764 (Fick & Fair) discloses a cone-shaped E-collar with a custom fittable closure. The device improves upon the traditional collar in that it provides a “one-size fits all” capability. However, the Fick device still suffers from design limitations in that it is a rigid collar that animals dislike.
[0008] U.S. Pat. No. 5,469,814 (Moy & Moy) discloses a protective collar that avoids the cone-shape of the traditional E-collar. In the Moy device, the collar comprises a sheet of flexible material sized to cover the entire neck from the back of the mandible to the scapula. Thus, the movement of the neck is restricted such that the animal is prevented from licking or biting at wounds. However, the device is not useful in protecting irritation of injuries to the head as the close fitting design does not prevent pawing of an injury of the head or face.
[0009] Similarly, U.S. Pat. No. 4,476,814 (Miller) discloses a donut shaped collar that is wide enough to prevent an animal from turning its head sufficiently in order to lick or chew at an affected area.
[0010] Likewise, U.S. Pat. No. 6,244,222 (Bowen) discloses a foam sleeve that like that disclosed in U.S. Pat. No. 5,469,814 covers a region of the animal's neck thereby preventing the animal from bending the neck in order to contact an affected area.
[0011] As discussed, the aforementioned E-collars are generally formed from rigid materials, such as plastic, that are uncomfortable and thus not well tolerated by animals. To overcome this problem, some collars have been disclosed that are formed from softer more compliant materials. For example, U.S. Pat. No. 5,133,295 (issued to Lippincott) discloses a collar that comprises two side-by-side rings of soft material, with non-resilient medical padding sewn together along their inner margins. The rings are gathered to form radial pleats that interfere with the ability of the animal to chew or lick affected body parts. However, as the collar could conceivably be bent backwards from the head, it would be possible for an animal to paw at injuries in the head area, again limiting the overall usefulness of this type of collar. Also, a soft e-collar can be easily chewed by the pet due to the inside material being loose.
SUMMARY
[0012] Accordingly it is an object of the present invention to provide a protective collar suitable for use as a veterinary restraint, and which overcomes problems inherent in prior art collars.
[0013] It is another object to provide a protective collar comprising resilient yet softer materials than is found in prior art E-collar type devices. To this end, the protective collar of the invention provides first and second sheets of flexible material between which is sandwiched a resilient padding layer. The padding layer provide sufficient structure to maintain the collar in the desired shape when fitted on an animal, but is soft enough such that the collar is more comfortable than prior art collars.
[0014] It is thus an object to provide a protective collar that takes advantage of the cone-shape of traditional E-collars, yet is made of more compliant materials such that an animal fitted with the collar will better tolerate it. The collar may be produced in various sizes to accommodate animals of different size, or may provide multiple closures to permit fitting of a single collar onto animals of differing size. Also, using the multiple closure features, the shape of the cone can be adjusted, for example, to be narrower at the outside, or wider at the outside. The user can conform the shape as desired to conform to the pet's head and neck shape and size.
[0015] The resilient padding layer provides sufficient rigidity that the collar will hold its shape when in use. In one embodiment the padding layer is comprised of foam material. To maintain the structure of the collar, the padding layer is secured to the first and second sheets of flexible material.
[0016] In one embodiment the padding layer is laminated onto at least of the first and second sheets of flexible material. Securing the padding to the flexible sheet provides the further advantage of preventing the animal from tearing or otherwise separating the padding layer from the flexible sheets.
[0017] The use of stitching may be further used to secure the first and second sheets and padding layer. In one embodiment, radially oriented stitching advantageously provides folding lines to aid in folding the collar for storage when it is not in use.
[0018] Fitting the collar on an animal is simple. Fitting involves placing the inner edge of the collar around the animal's neck and then securing the ends of the collar, thus forming a truncated cone, with the large opening facing forward, and the smaller opening fitted around the animal's neck.
[0019] The securing means may be any suitable means that will maintain the ends of the collar in contact. In one embodiment the means of securing the collar are hook and loop matable fastener strips such as Velcro® strips placed substantially at each end of the collar. Other embodiments could make use of hook and loop arrangements, snaps or other like securing means.
[0020] The invention further provides a method of protecting an area on an animal's body from undesired contact such as chewing or biting by fitting a collar as described herein. The area to be protected could be a site of a surgical injury, for example surgical stitches, a non-surgical injury, or an area to which a topical medicament has been applied.
BRIEF DESCRIPTION OF DRAWINGS
[0021] FIG. 1 is a top view of an embodiment of the protective collar in the unfolded configuration.
[0022] FIG. 2 is a section view of the protective collar of FIG. 1 through 2 - 2 of FIG. 1 , depicting the arrangement of first and second exterior sheets and a padding layer and the stitching along each of the arcuate edges.
[0023] FIG. 3 is a perspective view of the protective collar of FIG. 1 , as it would appear when fitted on an animal.
[0024] FIG. 4 is a top view of another embodiment of the protective collar in the unfolded configuration.
[0025] FIG. 5 is a section view of the protective collar of FIG. 2 through 4 - 4 of FIG. 3 , depicting the arrangement of first and second exterior sheets and a padding layer and the stitching along each of the arcuate edges.
[0026] FIG. 6 is a folded view of the protective collar of FIG. 1 .
[0027] FIG. is a folded view of the protective collar of FIG. 3 .
[0028] FIGS. 8A-8D show folding steps for folding a protective collar into the form as shown in FIG. 7 .
[0029] FIGS. 9A-9D show another set of folding steps for folding a protective collar into the form as shown in FIG. 6 .
[0030] FIG. 10 shows the protective collar such as in FIG. 1 with its ends attached by use of hook and loop fasteners being mated in a skewed orientation to provide a selected fit.
[0031] FIG. 11 shows the protective collar such as in FIG. 1 with its end attached in which the mating strips of hook and loop fasteners are aligned.
[0032] FIG. 12 shows the protective collar such as in FIG. 1 with its outer edge folded back exteriorly.
DETAILED DESCRIPTION
[0033] Referring first to FIGS. 1 , 2 and 3 , the present invention provides a protective collar 1 effective as a veterinary restraint when fitted on an animal. In this embodiment of the invention the protective collar 1 comprises a first exterior sheet 10 comprising a flexible material having inner and outer arcuate edges 12 and 14 respectively, the edges being generally concentric around a common center and extending between a first end 16 and a second end 18 . A second exterior sheet 20 (underneath sheet 10 in FIG. 1 ) also comprises a flexible material. The second exterior sheet 20 is substantially the same size and shape to enable creating the two sides of the collar with a space for a resilient padding layer 22 as shown in FIG. 2 .
[0034] The resilient padding layer 22 , also of a generally similar shape to the first and second exterior sheets 10 and 20 , and is sized to be located between the first and second exterior sheets 10 and 20 as shown in FIG. 2 . When assembled, the first and second exterior sheets 10 and 20 and the resilient padding layer 30 form a substantially at least semi-circular shape, as has been shown in FIG. 1 . Actually, in order to allow a lot of size adjustability, it is somewhat greater than semi-circular.
[0035] The first and second exterior sheets 10 and 20 can be fashioned from a variety of materials including cloth, rubberized cloth, soft plastic and the like. Apart from the physical quality to provide a soft, flexible surface of the finished assembly, the first and second exterior sheets and the resilient padding between then, when formed into the in-use cone shape needs only to be sufficiently rigid and resilient to be self-supporting. The present invention uses materials that are soft and flexible and specifically avoids the use of rigid plastic sheet materials as is commonly found in traditional E-collars. In one particular, it may be desirable to select a soft-surfaced comfortable material for the inside of the collar adjacent to the animals head and neck, and a more rugged material for the outside pf the collar. Also, the outside of the collar may be provided in a decorative motif, and may be made of material that is easily cleaned and/or that is resistant to staining.
[0036] The padding layer 22 may also be fashioned from a variety of materials. The material used in the padding layer 22 should be flexible enough to provide a collar that is softer and therefore more comfortable than traditional e-collar, yet is rigid enough to maintain the desired cone-like shape of the collar when worn by an animal and sufficiently resilient to return to its cone shape when bent. It is preferred that the first and second exterior sheets 10 and 20 be quite flexible with little resilience and resistance to bending, while the padding layer 22 be more resilient such that when they are formed into a unit and applied to an animal in a cone shape it will be sufficiently rigid to maintain its cone configuration yet will easily give when hit or pushed or bent and resilient enough to recover its cone shape. Foam plastic is a good material for use as the padding layer, and a wide range of resiliency, and thickness is available.
[0037] In the embodiment of FIGS. 1 , 2 and 3 the padding layer 22 comprises a layer of foam sandwiched between the first and second exterior sheets 10 and 20 , as shown in FIG. 2 . Other materials such as non-woven sheets or like materials may be used to provide a soft sufficiently resilient and rigid padding layer. The first exterior sheet 10 and the second exterior sheet 20 are joined along their peripheries 12 and 14 by sewing.
[0038] In the embodiment shown in FIGS. 1 , 2 and 3 , using separate exterior sheets 10 and 20 , they are sewn together along the inner arcuate edge 12 and the outer arcuate edge 14 using conventional hem sewing techniques, using outer hem strips 24 and 26 as shown in FIG. 2 , with the padding layer 30 inside. The padding layer 22 may be sewn-in along the inner arcuate edge or the outer arcuate edge, or just retained in the space, the latter being shown in FIG. 2 . The outer hem strip 24 (and also hem strip 26 ) can be made with a reflective surface or a glow-in-the-dark surface for safety and otherwise to easily spot the pet.
[0039] Stitching can be used to further strengthen the collar while still allowing it to easily bend on contact and also to provide folding points. Radially extending stitching 28 a , 28 b and 28 c comprising two parallel rows, provides some additional rigidity radially and also provides convenient folding points upon which the collar can be folded for storage or packaging, and further strengthen the integrity of the collar when in use. The preferred stitching is zigzag type or parallel rows of straight stitching that is of a selected width dimension such as about ⅛ inch to about ¼ inch and they extend substantially fully across the width from the arcuate edge 14 to the arcuate edge 12 . Examples of collars folded for storage or packaging are shown in FIGS. 6-9 d and are described below. It can be appreciated that the radial stitching lines are placed so that the collar will fold into at least approximately equal segments such that stitch 28 a is about at the center of the collar and stitches 28 b and 28 c are about half way to the beginning of the closure elements. That will allow it to be optimally folded for packaging or storage.
[0040] The invention further comprises a means of closure, effective to secure the ends of the protective collar, such that when the ends of the protective collar are secured, the collar forms a truncated cone with an inner opening 30 and an outer opening 32 as shown in FIG. 3 . Various means of closure are suitable for use in the invention. In one embodiment hook and loop fastener strips such as Velcro products conveniently secure the ends of the collar to form the desired cone shape as shown in FIG. 3 . In the embodiment shown in FIGS. 1 , 2 and 3 , a plurality of first hook and loop strips 34 are on the exterior sheet 10 (facing up in FIG. 1 ), in the example, three strips 34 and three sets of tabs 38 and mating plurality of three second hook and loop strips 36 are on the exterior sheet 20 (facing down in FIG. 1 ). Also, downward facing tabs 40 are sewn onto the end 16 being fastenable to any pair of the tabs 38 , or any of the strips 34 . As shown in FIG. 1 each end of the protective collar has three strips of fastener material 34 and 36 respectively. This allows the device to be sized appropriately to the animal by allowing a variety of engagement positions for greater or lesser opening neck fitting. Also, with the use of the tabs 40 , in addition to providing options for sizing, the edge 16 can be kept from protruding. As few as one strip on one side and two strips on the other side will allow for minimal size adjustability. Using the multiple closure position features, such as the plurality of hook and loop strips a fitted closure can be selected for mating alignment and matching of the outer and inner edges such as shown in FIG. 11 . This can be referred to as normal or edge aligned fitting. Also, the plurality of strips and tabs allow for non-edge matched closure, such that for example, the strips may be crossed with respect to each other to be not evenly aligned, so that the shape of the cone can be adjusted, for example, to be narrower at the outside, or wider at the outside or similarly at the inside, such as shown in FIG. 10 . This can be referred to as distortion fitting or personalized fitting. The user can conform the shape as desired to conform to the pet's head and neck shape and size. In yet another embodiment snaps are used to secure the ends of the collar.
[0041] To maintain the integrity of the collar, the invention provides for a means of securing the first and second exterior sheets to the resilient padding layer. In one embodiment the means of securing the first and second sheets and padding layers comprises laminating or otherwise adhering the padding layer onto at least one of the exterior sheets of flexible material. In another embodiment, the padding layer is laminated or adhered onto both the first and second exterior sheets. Securing the padding layer to the sheets further prevents the animal from separating the layers of the collar and either reducing the effectiveness of the collar or destroying it altogether. In a preferred embodiment the padding layer is laminated or adhered only to the exterior sheet that will be on the inside of the cone, when formed around the animal's head.
[0042] Another construction of the protective collar is shown in FIGS. 4 and 5 . It is similar generally to the form in FIGS. 1 , 2 , and 3 , but is suitable for smaller sizes, and softer material. In this form a first exterior sheet 40 and a second exterior sheet 42 are sewn together at the outer arcuate edge 44 with a blind hem stitch while the inner arcuate edge 46 has a regular hem stitch with a hem strip 48 . Radial stitching 50 does not extend to the outer arcuate edge 44 or to the inner arcuate edge 46 but rather stops short of them leaving a space 56 adjacent the outer arcuate edge 44 . There can also be a space 58 adjacent the inner arcuate edge 46 . Ends 60 and 62 have near them fasteners such as strips of mating hook and loop fasteners 64 and 68 . Also a tab 70 can fasten either to one of the strips 68 or to a patch 72 . This construction is preferred for smaller sized protective collars in which a very light weight combination of materials is used such as for cats or kittens For example, the exterior sheets may be sheets of thin or cloth reinforced plastic sheet and the spaces 56 and 58 allow for easy bending. An inner padding 52 can be foam or other material as described above; and it may be adhered to the first exterior sheet or the second exterior sheet or both; preferable at least to the exterior sheet that will form the inside of the cone proximate the animal that is wearing it. This construction is preferred for smaller pets such as kittens. It is more easily flexed so as to make eating easier for the pet.
[0043] Conveniently, a number of neck closure means may be provided in order to provide the ability to fashion a protective collar capable of fitting different size animals. As shown in FIGS. 1 , 3 and 4 , a series of loops 54 are sewn into the hem. These can be made of elastic material so as to stretch to accept the pet's normal collar. Alternatively, a string 62 or other elongated member can be applied through the loops and pulled comfortably around the animal's neck to keep the unit in place. In another embodiment, a drawstring sewn into the inner edge might also be useful to further secure the collar on the animal.
[0044] When placed on an animal, the inner opening 30 is adapted to fit securely around the neck of the animal, and the outer opening 32 is of sufficient size to prevent the animal fitted with the protective collar from contacting an area of the body to be protected. If desired, the inner arcuate edge of the collar may be lined with a softer material to increase the comfort of the collar.
[0045] Referring to FIG. 12 , with the construction as described above, providing a bendable and resilient construction, sufficient to be self supporting, the protective collar can be folded outwardly along its outer margin to provide a cuff 70 . This will allow more freedom of movement for the pet's head giving the protective collar more variety of configurations for a wide range of pet sizes.
[0046] Notably, these constructions for a protective collar do not have to slip over the head of the pet, but rather can close around the neck.
[0047] The exterior sheet or sheets such as sheets 10 and 20 in FIG. 1 can be made as spaces for advertising or personal messages by owners. Also the collar strip strung into the loops 54 can carry advertising or other types of messages. Such messages can relate to beneficial or charitable content or they can be commercial. The collar strip can be reserved with an area in which the owner can implement her own message
[0048] The invention further provides a method of using a pet protective collar as described above as a veterinary restraint. The method comprises placing a collar such as that described herein around the neck of an animal, and securing as described. Conveniently, the collar of the invention is suitable to protect an area from contact by the animal's mouth, and yet is comfortable enough to wear that the animal will tolerate the collar.
[0049] An additional feature of the invention lies in the ability to fold it into a small package for selling purposes or for the consumer to store it. One folding configuration is shown in FIGS. 7 , 8 A through 8 D. This configuration is most suitable for smaller sizes with very easily flexed soft material such as the version described as illustrated in FIGS. 4 and 5 . In this fold configuration the ends 60 and 62 meet and the fold points at 56 a and 56 b are together, the soft material being able to allow the fold points 56 a and 56 b to settle together. Another fold configuration is shown in FIGS. 6 and 9A through 9 B. This configuration is most suitable for larger sizes with less easily flexed material such as the version described and illustrated in FIGS. 1 and 2 . In this fold configuration ends 16 and 18 meet and are held together by the tabs 40 and 38 fastening to a mating strip 34 while the fold points 28 a and 28 b are separate and the fold point 28 b is captured between close to the ends 16 and 18 .
[0050] The collar is thus suitable for use in a method of protecting a wound from a surgical procedure, an injury that is non-surgical in nature, or to prevent mouth contact of an area to which a topical medicament has been applied.
[0051] When applied, it is known that some animals will use their teeth to try to dislodge the collar. This is where adhering the inside layer to the padding is particularly useful because it prevents the animal from finding or creating a fold by biting.
[0052] The foregoing detailed description of exemplary and preferred embodiments is presented for purposes of illustration and disclosure in accordance with the requirements of the law. It is not intended to be exhaustive nor to limit the invention to the precise form or forms described, but only to enable others skilled in the art to understand how the invention may be suited for a particular use or implementation. The possibility of modifications and variations will be apparent to practitioners skilled in the art. No limitation is intended by the description of exemplary embodiments which may have included tolerances, feature dimensions, specific operating conditions, engineering specifications, or the like, and which may vary between implementations or with changes to the state of the art, and no limitation should be implied therefrom. This disclosure has been made with respect to the current state of the art, but also contemplates advancements and that adaptations in the future may take into consideration of those advancements, namely in accordance with the then current state of the art. It is intended that the scope of the invention be defined by the Claims as written and equivalents as applicable. Reference to a claim element in the singular is not intended to mean “one and only one” unless explicitly so stated. Moreover, no element, component, nor method or process step in this disclosure is intended to be dedicated to the public regardless of whether the element, component, or step is explicitly recited in the Claims. No claim element herein is to be construed under the provisions of 35 U.S.C. Sec. 112, sixth paragraph, unless the element is expressly recited using the phrase “means for . . . ” and no method or process step herein is to be construed under those provisions unless the step, or steps, are expressly recited using the phrase “comprising step(s) for . . . ”
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A custom fittable collar for an animal, useful to prevent the animal from contacting injured areas on the body, thus promoting healing of wounds. The collar comprises opposing sheets of flexible material with a resilient material held between them. The resulting collar is rigid enough to resist deformation thus preventing licking or biting of a wound by the animal, but soft enough that the collar is both comfortable to wear, and less likely to catch on other objects, thus improving the safety and wearability of the collar. The collar further comprises a closure assembly adapted for easy placement or removal of the collar. The collar further comprises stitching that creates fold lines to allow the collar to be conveniently folded.
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[0001] This application is related to, and claims priority from, U.S. Provisional application No. 60/351,620 filed Jan. 24, 2002 and hereby incorporates that application by reference. This application is also related to, and claims priority from, U.S. Provisional application No. 60/361,448 filed Mar. 21, 2002 and hereby incorporates that application by reference. This application is also related to, and claims priority from, United States Provisional patent application No. 60/392,007 filed Jun. 26, 2002 and hereby incorporates that application by reference. This application is also related to and claims priority from United States provisional patent application 60,411,907 filed Sep. 18, 2002 and hereby incorporates that application by reference. This application also claims priority from German patent application DE 202 11 854 filed Aug. 1, 2002.
FIELD OF THE INVENTION
[0002] The present invention relates to the field of polymers and paints containing polymers and more particularly to polymers with bioresistant, fungal resistant and antimicrobial/antifungal properties.
DESCRIPTION OF THE PROBLEM SOLVED BY THE INVENTION
[0003] Due to environmental regulation, the use of tin, mercury, lead, and other heavy metals in coatings is illegal in most of the developed world. In particular marine coatings and paint suffer a failure mode when attacked by microbes. The problem is especially acute in that section of the hull of a vessel that is alternately submerged and exposed to air. Microbial attack can eventually destroy the coating completely. Previously, heavy metals were used in coatings to combat this attack.
[0004] Some methods have been devised that distribute an oil-soluble antimicrobial agent in the coating, relying on the water insolubility and limited mobility of the agent in the coating to hold the agent. However, it is well known that all liquids, and to a lesser extent all solids, are either somewhat soluble in water, or can be absorbed or leached into water to some extent. After repeated cycles of being submerged and exposed, the agent is sufficiently leached from the coating rendering the coating susceptible to microbial attack; hence the coating becomes ineffective. One solution to the leaching problem has been to create a coating that is sacrificial and is designed to wear away as it ages, exposing fresh antimicrobial agent to the surface. Here the life is proportional to coating thickness. Thick coatings are however a problem in marine coatings as they increase the weight and cost of the coating.
[0005] The painting of the hull of a marine vessel is a very expensive and cumbersome operation because the vessel must be drydocked. This is expensive in itself, and costs increase because of the length of time the vessel must be out of service. Thus, any means of extending the protective coating's life has great economic impact.
[0006] What is badly needed is a polymer type coating that has bioresistive, fungal resistive or antimicrobial/antifungal properties that can be used in paints and in other applications of polymers where it is desired to prevent microbial attack of the polymer and/or prevent the polymer from acting as a substrate and/or food source for bacteria, and/or fungi, or can kill microbes directly.
[0007] It is also believed that polymers of the type described in this invention will aid in the adhesion of the polymer to various substrates when used as part of a coating or adhesive.
SUMMARY OF THE INVENTION
[0008] The present invention comprises a polymer that contains an antimicrobial moiety that is linked into the backbone of the polymer. This moiety is, in general, a bromine atom and a nitro (NO2) group linked to one or more of the carbon atoms forming the backbone of the polymer. While the present invention is directed primarily to urethane type polymers, the moiety taught should also be effective when linked onto a carbon atom in the backbone of any polymer. The moiety can appear in the polymer chain in various levels of occurrence. A preferred occurrence of around 1000 parts per million to around 20,000 parts per million is effective. However the frequency of occurrence can be as low as 5 parts per million to as high as 100%. Polymer types within the scope of the invention include, but are not limited to polyurethane, polyurea, polyamide, polyester, polycarbonate, polyether, polysiloxane, epoxy, polyacrylic, polyacrylate and polyvinyl linkages.
[0009] It is well known in the art to combine an organic isocyanate with a polyol (poly alcohol) or polyol polymer in the presence of a suitable catalyst to form a polyurethane polymer. The present invention adds a bromo-nitro substituted diol or polyol to a standard polyol to be used in the polymer synthesis. The proportion of substituted compound used is chosen to yield the desired concentration of the moiety in the final polymer. A preferred diol for the application is bromonitropropanediol or 2-bromo-2-nitro-propane-1-3-diol or simply BNPD. This particular diol is a solid material with varying degrees of solubility in other polyols and has proven antimicrobial properties.
[0010] In addition, BNPD has been shown to have no tetragenecy (cancer causing effects) and is approved by the CFTA at levels of up to 0.1% for use in cosmetics. BNPD has also been used in baby wipes for its antimicrobial properties.
[0011] The fact that the active antimicrobial moiety is covalently linked directly into the backbone of the polymer prevents it from leaching out under even very severe conditions of repeated submersion and exposure. In addition, the moiety is not photo-active or decomposed by sunlight or exposure to mineral salts such as sodium chloride as found in sea water.
[0012] Because BNPD is a substituted diol, it is a natural reactant to form part of a polymeric chain with an isocyanate. Also, being a diol, it mixes directly with a wide range of solvents, polyols and other performance enhancing additives with no difficulty or adverse reactions. In fact, it can be mixed in any desired proportion (to the extent that it is soluble with or without the aid of a solvent or co-solvent) with any standard polyol used in synthesizing polyurethane or other polymers. There also appears to be little ability of the bromine or nitro group to form undesirable cross links in the resulting polymer. BNPD can also be added directly to an isocyanate or polyisocyanate and heated to the reaction temperature required for the specific isocyanate or polyisocyanate. If an excess of isocyanate is added in various proportions, such as 2 equivelents to one, a BNPD containing isocyanate or polyisocyanate results. This product is then an excellent component to cross-link other polyols or polyamines.
[0013] While bromonitropropanediol (BNPD) is the preferred antimicrobial agent because of its proven activity and its benign effects on the environment and on humans, it is clear to one skilled in the art that other diols or polyols with bromine and nitro groups linked at the same or different carbon atoms could also be incorporated into the backbone of polymers. Therefore other antimicrobial agents that can be linked onto a diol or polyol chain are within the scope of the present invention.
DESCRIPTION OF THE DRAWINGS
[0014] [0014]FIG. 1. Shows the generic steps of forming a polymer with a bromine/nitor moiety after removal of water and condensation polymerization. FIG. 2 and FIG. 2A show the standard method of making polymacon as well as two methods of making a modified polymacon containing the desired moiety.
[0015] [0015]FIG. 3 shows treatment of BNPD with ammonium hydroxide to form a bromonitro amine or diamine which can then be combined with an isocyanate compound such as TDI (toluene diisocyanate) to yield a polyurea.
[0016] [0016]FIG. 4 shows BNPD used to form a polyester.
[0017] [0017]FIG. 5 shows a polyamide structure.
[0018] [0018]FIG. 6 shows the standard structure of a polyamide.
[0019] [0019]FIG. 7 shows a modified polyether and a modified polysiloxane.
DETAILED DESCRIPTION OF THE INVENTION
[0020] It is well known in the art to combine polyols or polyol pre-polymers with organic isocyanates and other materials to form polymers and polymer resins. In particular paints, including marine paint, many times contains polyurethane or other polymer coating materials. A generic urethane has the following structure:
[0021] It is well known in the art that R and R′ can be the same or different. A typical polyurethane polymer is made up of chains of the form:
[0022] or of the form:
[0023] It is also known that the compound bromonitropropanediol or 2-bromo-2-nitro-propane-1-3-diol (BNPD) has antimicrobial properties. Tests on this compound have shown that it is effective against various strains of both gram positive and gram negative bacteria in concentrations of 1-50 ppm with the average minimum inhibitory concentration being around 25 ppm. In addition, work has indicated that BNPD is also antifungal.
[0024] BNPD has the following structure:
[0025] Because BNPD is a polyol, it can be combined with other polyol or polyol pre-polymers to make many polymers and coatings.
[0026] In particular, BNPD mixed polyols can be combined with organic isocyanates to form polyurethane type coatings and polymers. This causes the active moiety to become covalently linked into the backbone of the polymer. In particular, BNPD or similar compounds containing the desired moiety can be mixed with the polyol component of commercially available two-component systems known in the art. In the case of polyurethane, the linked moiety is similar to:
[0027] Or more generally:
[0028] While BNPD is a preferred polyol starting point to link the active moiety into a polymer, it is within the scope of the present invention to use many other materials that contain a bromine atom and nitro group linked near one another. The preferred class of compounds have the bromine and nitro linked to the same carbon atom; however, it is felt that a moiety where the bromine and nitro are not linked to the same carbon, but near each other will still be effective. Many other compounds are within the scope of the present invention. In particular, bromonitromethanediol, bromonitroethanediol, bromonitrobutanediol, etc. can also be substituted into polymer backbones with similar results. The prior art has shown that bromonitromethane is effective for the treatment of nematodes in the soil (See U.S. Pat. No. 5,013,762) and as a general biocide (See U.S. Pat. No. 5,866,511). It is felt that bromonitromethanediol and similar diols will be equally effective.
[0029] The present invention also includes using a BNPD or BNPD analog as the terminus, such as:
[0030] Where R′ can be, but is not limited, to CH2OH, OH, CH3, or H. The present invention also includes the presence of BNPD or a BNPD analog as described above as a sidechain as is the case in FIG. 2.
[0031] Methods of making polyurethane coatings for paints are well known in the art. For example U.S. Pat. No. 5,712,342 gives several examples of a process for producing a water-dispersion of polyurethane resin for a paint using a prepolymer of approximate molecular weight 800 made from phenylpropane and various isocyanates such as isophoron-diisocyanate to produce final polymers with average molecular weights of around 3200 for coatings used in paint. This patent (U.S. Pat. No. 5,712,342) is hereby incorporated by reference.
[0032] U.S. Pat. No. 3,936,409 teaches a method of manufacturing urea-urethanes using organic solvents. Formation in solution where the solvent is allowed to evaporate causing a cure, and immediate formation through the use of a spray gun are taught. This patent (U.S. Pat. No. 3,936,409) is hereby incorporated by reference.
[0033] The present invention dissolves BNPD or similar substituted hydrocarbon diols into the polyols, with or without the aid of a solvent or co-solvent, used to create the prepolymers so that the active moiety of bromine and nitro becomes linked into the backbone of the final polymer at an occurrence rate of between 5 ppm up to 100% with a preferred occurrence rate of around 1000 ppm. The molecular weights of final polymers can range from several thousand for coatings to hundreds of thousands or higher for various other polymers where antimicrobial or antifungal properties are desired.
[0034] U.S. Pat. No. 5,798,115 teaches linking of other antimicrobial agents into the backbone of polymers used in medical applications. In particular diisocynates are reacted with an antimicrobial agent ciprofloxacin to form polymeric materials. Here a biodegradable polymer is formed that releases antimicrobial substances as it is degraded by enzymes. This patent (U.S. Pat. No. 5,798,115) is hereby incorporated by reference.
[0035] Polymers for the medical industry and many other purposes containing the active moiety of bromine and nitro linked to an aliphatic chain which is covalently bonded into the polymer backbone for the purpose of killing microbes or inhibiting degradation caused by microbes or fungus are also within the scope of the present invention. In fact, the present invention finds application wherever a polymer is needed that has antimicrobial, antifungal, bioresistant or fungal resistant properties.
[0036] The present invention covalently links a bromine/nitro moiety into the backbone of a polymer to provide antibaterial or anti-fungal effect. The general principle taught by the present invention applies to polyurethane, polyurea, polyacrylates, polymethacrylates, polyacrylics, polyesters, polyamides, polyimides, polycarbonates, polyglycolic acid, polylactic acid, polyethers, polysiloxanes, epoxies and many other types of polymer structures.
[0037] Of particular interest are polymers made from polylactic acid. These polymers have been known in the art since 1932. Lactic acid can be made commercially by fermenting dextrose from corn. Lactic acid intermediates called lactides are made from L-lactic acid and R-lactic acid. Properties of the final polymers can be controlled by the percentage of L and R isomer ratios.
[0038] Polylactic acid polymers have the property that they are biodegradable. Because applications of the present invention include many applications that may require or desire inhibiting the natural rate of this biodegradation, the present invention applies to this class of polymer as well. An example of a polylactic acid polymer using the teachings of the present invention combines lactic acid with BNPD. A polymer is formed with the bromine/nitro moiety after removal of water and condensation polymerization. The generic steps are shown in FIG. 1. It should be remembered that the steps shown in FIG. 1 are only generic and that other ways of linking in the bromine/nitro moiety are within the scope of the present invention.
[0039] Similar to polylactic acid, polyglycolic acid is of particular interest. Polyglycolic acid is another biodegradeable polymer that can benefit from controlling the rate of biodegradation.
[0040] Another class of polymers using the teachings of the present invention are polymethacrylate polymers used in contact lenses such as polymacon.
[0041] [0041]FIG. 2 and FIG. 2A show the standard method of making polymacon as well as two methods of making a modified polymacon containing the desired moiety. Either methacrylic acid or methyl methacrylate can be combined with BNPD or a similar diol with a bromine and nitro group linked to the same carbon atom. Generally 2 moles of methacrylic acid are reacted with one mole of BNPD (however, equamolar quantities can also be used). The resulting product can then be combined with ethylene glycol dimethacrylate (2-Hydroxyethyl Methacrylate). Ethylene glycol monomethacrylate can also be added to reach the desired properties.
[0042] U.S. Pat. No. 4,109,074 teaches the basic process for making this type of hydrophilic polymer from the monomer. The basic polymer is prepared by heating a monomer such as ethylene glycol monomethacrylate to a certain temperature for a certain time. No initiator or catalyst is used in the original process. This has the desirable property of yielding a polymer that is immediately free of any toxic residue from an initiator or catalyst. This is particularly desirable in medical products such as contact lenses. This patent (U.S. Pat. No. 4,109,074) is hereby incorporated by reference.
[0043] A major problem with contact lenses is the danger of bacterial infection leading to eye irritation or even more serious infections that can result in blindness. It would be very desirable to be able to produce a suitable hydrophilic polymer that inhibits bacterial growth at its surface. The linking of the bromine/nitro moiety as herein taught can result in a suitable polymer with the desired bacterial resistant properties.
[0044] [0044]FIG. 3 shows treatment of BNPD with ammonium hydroxide to form a bromonitro amine or diamine which can then be combined with an isocyanate compound such as TDI (toluene diisocyanate) to yield a polyurea. FIG. 3 shows two possible structures that are within the scope of the present invention, one with two nitrogens linked to a carbonyl group and one with only one.
[0045] [0045]FIG. 4 shows BNPD used to form a polyester, while FIG. 5 shows a polyamide structure. FIG. 6 shows the standard structure of the polyamide known as Nylon Sixty-Six (NYLON is the registered trademark of DuPont Corp.). The modified polyamide structure containing the bromine/nitro moiety is clearly seen. It should be understood that the all polyamides are within the scope of the present invention.
[0046] [0046]FIG. 6 shows a modified epoxy resin while FIG. 7 shows a modified polyether and a modified polysiloxane. Both of these classes of structures are within the scope of the present invention. Again, all polyethers and polysiloxanes are within the scope of the present invention.
[0047] The invention relates to a bromo-nitro moiety covalently linked into the backbone of various polymers in order to provide bacterial and fungus resistance or antibacterial/antifungal polymers of many different categories and types. The invention has many useful industrial applications.
EXAMPLES
Example 1
Urethane
[0048] 6 g BNPD were desolved in 14 g γ-Butyrolacton (BLO) with strong mixing. In these 100 g urethane quality castor-oil was added also with strong mixing. Then into this mixture, 42 g aromatic isocyanate Bayer Mondur XP-744 was added drop by drop over twenty minutes, followed an additional 20 minutes of strong mixing. This prepolymer urethane of the castor-oil/BNPD can be called T-31BR.
[0049] To 39 g of Chemoddities HP70 acryl polyole, 0.12 g Eagle Sales FB 100 Defoamer, and 0.12 g Eagle Sales FX-6 slip Aid were added 15 g T-31BR. This mixture can be called componet I. To componet I was added 11 g Bayer Mondur XP-744 flavour TIC isocyanate prepolymer and 10 g BLO. The BLO was to improve flow. A sample was taken off as film, which was an excellent clear urethane layer.
[0050] The acrylic urethane layer contained 0.85% BNPD.
Example 2
Urethane
[0051] 150 g of BNPD was dissolved in 150 g BLO. To 150 g of this solution was added 270 g Bayer Mondur XP-744 and heated to 150 F and held for 30 minutes. The BNPD containing isocyanate functional cross-linker was allowed to cool to room temperature.
[0052] To 25 g of the BNPD containing isocyanate cross-linker was added 30 g Chem-oddities HP70 acrylic polyol with strong mixing. This was drawndown to yield a clear, tack free urethane film that contained 9.9% BNPD.
Example 3
Urethane
[0053] 10 g of BNPD was dissolved in 15 g BLO. To this solution was added 18 g Bayer Mondur XP-744 and mixed. To this solution was added 0.1 g Troymax 16% Zinc catylst. As soon as heat was seen to be evolved, the mixture was drawndown. The resulting, tack-free urethane film contained 35.7% BNPD.
Example 4
Urethane
[0054] 10 g of BNPD was added directly to 18 g Bayer Mondur XP-744 and heated to 230 F and held for 30 minutes. The resulting product was drawndown and yielded a clear tack-free urethane film that contained 35.7% BNPD.
Example 5
Acrylate Resin
[0055] 400 g (2 mol) BNPD with 344 g (4 mol) methyl methylmethacrylate and 150 g xylene (reflux solvent) was combined in a nitrogen covered reaction vessel with a water condenser/trap. The mixture was heated to 141 degrees C., at which time trapped water was released. The reaction vessel has held between 154-156 degrees C. until the rate of the water loss was nearly zero. (3 hours and 7 minutes). The theoretical loss of water was 72 g. 53 g was recovered, and approximately 19 g unreacted BNPD was left in the reaktion vessel. The unreacted BNPD was removed. This conversion product can be called MAA/BNPD-002.
[0056] Then 360 g xylene were added to a reaction vessel with agitation. The container had a nitrogen blanket and a water condenser/trap, and was heated to 141 degrees C. To this, drop by drop, over 3 hours, 20 g MAA/BNPD-002 was combined with 598 g Isobutylmethacrylate and 20 g Tert Butylperoxybenzoate were added. After adding was complete, the container was held at 142 degrees C. for 55 minutes. Then 2 g of Tert Butylperoxybenzoate in 18 g Xylene were added, and the mixture was held at 142 degrees C. for one hour. Then 2 g more of Tert Butylperoxybenzoate in 18 g Xylene were added, and again the mixture was held at 142 degrees C. for one hour. Finally 6 g Tert Butylperoxybenzoate were added, and the mixture was held at 142 degrees C. again for one hour. Then the container was removed from the heat and left to cool.
[0057] The resulting polymer had a color of bright straw, with enough transparency to be used as a clear coat. The material was drawn out to confirm this. This resin contains 924 ppm BNPD.
Example 6
Polyester Resin
[0058] In a reaction vessel with a nitrogen blanket and water condenser/trap 400 g (2 mole) BNPD were mixed with 616 g (4 mole) 1,2-Cyclohexandicarboxlic anhydride (HHPA) and 150 g Xylene as a reaction solvent and heated with agitation.
[0059] The container was heated to 162 degrees C., at which point the reaction became exothermic. The temperature was then reduced to 150 degrees of C and held for one hour 1162 g of a conversion product, a strong, dark transparent liquid, was recovered. This conversion product can be called MAA/BNPD-003.
[0060] In a reaction vessel with a nitrogen blanket and water condenser/trap 416 g Neopentylglycol (NPG) and 1,7 g HHPA/BNPD-003 was heated with agitation. The container was heated until the NPG began to melt. Stirring turned on and the temperature held at 149 degrees C. for one hour and 38 minutes. Then 438 g of Adipic acid were added to the container, and after two minutes water started to be released.
[0061] The container was then held between 156 degrees C. and 172 degrees C. for 3 hours, until the release of the water stopped and the temperature began to rise. A total quantity 108 g water was released. The resulting resin has a brownish color and was very clear and transparent. It contained 896 ppm BNPD.
Example 7
Diester n=1
[0062] [0062]
[0063] 1,128 g oleic acid and 400 g BNPD plus 2 g sulfuric were charged in a three neck round bottom flask with agitation, nitrogen, and condenser and heated to 350 F and held for 2.5 hrs until 80 ml of water were recovered. This product was then incorporated into Engineered Lubricants Encool SS at 6% and 10% of the concentrate.
[0064] These samples were then submitted for ASTM D-3946-92 testing. The samples at day 5 were compared and the sample with 6% incorporation had a bacterial count of 1.5×10 4 and the sample with 10% incorporation had a bacterial count of 3×10 3 versus 1×10 7 for the sample without the product incorporated.
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A polymer that contains an antimicrobial, bioresistant and fungal resistant moiety that is linked into the backbone of the polymer. The moiety is a bromine atom and a nitro group linked to one or more of the carbon atoms forming the backbone. The moiety can appear in the polymer chain in various levels of occurence from 5 ppm to has high as 100% with a normal occurance of between 1000 ppm to 20,000 ppm. Polymer types that can be created with this moiety to display these properties include, but are not limited to, polyurethane, polyurea, polyamide, polyester, polycarbonate, polyether, polysiloxane, epoxy, polyacrylic, polyacrylate, polyvinyl.
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PRIOR APPLICATION
This application claims priority from U.S. provisional patent application No. 60/277,646, filed Mar. 22, 2001, the specification of which is incorporated herein in its entirety.
FIELD OF INVENTION
This invention relates to a family of polypeptides having properties which ameliorate or retard effects of aging in mammals, particularly by reducing age related increase in fat, and/or reducing age related decrease in lean body mass.
BACKGROUND OF INVENTION
Obesity, defined as an excess of body fat relative to lean body mass, is thought to be associated with important psychological and medical morbidities, the latter including cardiovascular disease, hypertension, elevated blood lipids, and Type II or non-insulin-dependent diabetes melitis (NIDDM). Despite a vast amount of research, the molecular factors regulating food intake and body weight balance are incompletely understood. Myriad approaches to reducing obesity and associated effects have been attempted over the years. There remains a persistent need for addressing these problems, but a particularly useful approach would be one that involves a reduction in the general increase in the amount of body fat relative to lean body mass that occurs with aging.
SUMMARY OF INVENTION
In one broad aspect, the present invention is a method of ameliorating effects of aging in an animal. The method includes administering to the animal an effective amount of a chemical compound that includes a synthetic polypeptide comprising an amino acid sequence that has 10+q amino acids, wherein, under physiological conditions, residues numbered n, n+4, n+9 are positively charged amino acids, residues numbered n+3, n+7 are negatively charged amino acids, wherein the remaining amino acids are nonpolar amino acids or uncharged polar amino acids, wherein n is an integer from 1 to 1+q and q is a whole number greater than or equal to zero.
When it is stated herein that an amino acid is positively charged under physiological conditions, it is meant that the side chain group of the amino acid within the polypeptide, e.g. the amino group of a lysine, would be at least 10% protonated in an aqueous solution of pH about 6.5 and ionic strength 0.1. Likewise, when it is stated herein that an amino acid is negatively charged under physiological conditions, it is meant that the side chain group of the amino acid within the polypeptide, e.g. the carboxyl group of aspartate, would be at least 10% deprotonated under such conditions.
Preferably, the animal to which the polypeptide is administered is a mammal, most preferably a human.
In one aspect, ameliorating effects of aging includes reducing an age-related increase in fat.
In another, ameliorating effects of aging includes reducing an age-related decrease in lean body mass.
In yet another, ameliorating effects of aging includes reducing age-related reduction in bone mineral content-body weight ratio of the subject.
In yet another, ameliorating effects of aging include includes reducing age-related reduction in lean body mass-body weight ratio of the mammal.
There are preferred embodiments of the polypeptide, particularly one in which any one or more of the following is true: the amino acid at position n is arginine; n+1 is threonine or alanine; n+2 is asparagine or glutamine; n+3 is glutamic acid or aspartic acid; n+4 is histitdine, n+5 is threonine or alanine; n+6 is alanine or glycine; n+7 is glutamic acid or aspartic acid; n+8 is cysteine, alanine, tyrosine or serine; and n+9 is lysine. Preferably all of these conditions are met by the polypeptide part of the chemical compound.
In particular embodiments, at least one of the following is true: the amino acid at position n is arginine; n+3 is glutamic acid or aspartic acid; n+4 is histitdine, n+7 is glutamic acid or aspartic acid; and n+9 is lysine. Again, these conditions can be met in any combination with each other.
In other embodiments, at least one of the following are true: the amino acid at position n+1 is threonine or alanine; n+2 is asparagine or glutamine; n+5 is threonine or alanine; n+6 is alanine or glycine; and n+8 is cysteine, alanine, tyrosine or serine, yet again in any combination with each other.
In other embodiments, the polypeptide includes the amino acid sequence identified as SEQ ID NO:2 or SEQ ID NO:3 wherein up to 26 amino acids of the sequence have been deleted provided that amino acids 5 to 14 of the sequence are not deleted, or a substituted variant thereof in which (i) a non-polar, aliphatic neutral amino acid has been substituted for another non-polar, aliphatic neutral amino acid, (ii) a polar aliphatic neutral amino acid has been substituted for another polar aliphatic neutral amino acid, (iii) a charged acidic amino acid has been substituted for another charged acidic amino acid, (iv) a charged basic amino acid has been substituted for another charged basic amino acid, (v) cysteine has been substituted by alanine, or (vi) a combination of substitutions (i)-(v) has been made, in which said synthetic polypeptide ameliorates effects of aging in an animal.
In other embodiments, the polypeptide includes a sequence of amino acids which is encoded by a DNA that specifically hybridizes with DNA encoding the polypeptide consisting of any of SEQ ID NO:1, SEQ ID NO:2, SEQ ID NO:3, SEQ ID NO:4, SEQ ID NO:5, SEQ ID NO:6, SEQ ID NO:7, SEQ ID NO:8, SEQ ID NO:9, SEQ ID NO:10, SEQ ID NO:11, SEQ ID NO:12, SEQ ID NO:13, SEQ ID NO:14, SEQ ID NO:15, SEQ ID NO:16, SEQ ID NO:17, SEQ ID NO:18, SEQ ID NO:19, and SEQ ID NO:20, and which polypeptide ameliorates effects of aging in a mammal or retards effects of aging in a mammal.
SEQ ID NO:2 is encoded by the nucleotide sequence designated SEQ ID NO:45, as follows:
GGG ATC GGA AAA CGA ACA AAT GAA CAT ACG GCA GAT TGT AAA ATT AAA
Gly Ile Gly Lys Arg Thr Asn Glu His Thr Ala Asp Cys Lys Ile Lys
CCG AAC ACC TTG CAT AAA AAA GCT GCA GAG ACT TTA ATG GTC CTT GAC
Pro Asn Thr Leu His Lys Lys Ala Ala Glu Thr Leu Met Val Leu Asp
CAA AAT GAA CCA
Gln Asn Gln Pro
A person skilled in the art will understand that, due to the well known degeneracy of the genetic code, that there are other coding sequences that encode SEQ ID NO:2. Further, the polypeptide fragments of the present invention are similarly encoded by corresponding portions of SEQ ID NO:45.
A DNA sequence encoding a polypeptide having SEQ ID NO:1 (unprotected version identified as SEQ ID NO:35) is identified as SEQ ID NO:54. DNA sequences encoding polypeptides have SEQ ID NOs: 2 to 9, and 11 to 20 are identified as SEQ ID NOs:45 to 53 and 55 to 63, respectively. Unprotected versions of polypeptides identified as SEQ ID NOs:1, 10 to 20 and 33 are identified as SEQ ID NOs: 35, 9, 34, 36 to 44 and 2, respectively.
In other embodiments, the polypeptide includes a sequence of amino acids selected from the following group of sequences: SEQ ID NO:1, SEQ ID NO:2, SEQ ID NO:3, SEQ ID NO:4, SEQ ID NO:5, SEQ ID NO:6, SEQ ID NO:7, SEQ ID NO:8, SEQ ID NO:9, SEQ ID NO:10, SEQ ID NO:11, SEQ ID NO:12, SEQ ID NO:13, SEQ ID NO:14, SEQ ID NO:15, SEQ ID NO:16, SEQ ID NO:17, SEQ ID NO:18, SEQ ID NO:19, SEQ ID NO:20, and conservatively substituted variants of each of SEQ ID NO:1, SEQ ID NO:2, SEQ ID NO:3, SEQ ID NO:4, SEQ ID NO:5, SEQ ID NO:6, SEQ ID NO:7, SEQ ID NO:8, SEQ ID NO:9, SEQ ID NO:10, SEQ ID NO:11, SEQ ID NO:12, SEQ ID NO:13, SEQ ID NO:14, SEQ ID NO:15, SEQ ID NO:16, SEQ ID NO:17, SEQ ID NO:18, SEQ ID NO:19 and SEQ ID NO:20 which ameliorate effects of aging in a mammal.
In particularly preferred embodiments, the polypeptide is one which ameliorates effects of aging in a mammal and includes a sequence of amino acids selected from the following group of sequences: SEQ ID NO:1, SEQ ID NO:2, SEQ ID NO:3, SEQ ID NO:4, SEQ ID NO:5, SEQ ID NO:6, SEQ ID NO:7, SEQ ID NO:8, SEQ ID NO:9, SEQ ID NO:10, SEQ ID NO:11, SEQ ID NO:12, SEQ ID NO:13, SEQ ID NO:14, SEQ ID NO:15, SEQ ID NO:16, SEQ ID NO:17, SEQ ID NO:18, SEQ ID NO:19, and SEQ ID NO:20.
In a particularly preferred embodiment, the polypeptide is one which ameliorates effects of aging in a mammal and includes SEQ ID NO:1.
Another aspect of the invention is a method of manufacturing a medicament for use in ameliorating effects of aging in a mammal. The method includes the following steps:
(a) providing a composition in dosage form, the composition containing a chemical compound of the present invention (see above);
(b) packaging the composition; and
(c) providing the package with a label instructing a user to administer the composition as a medicament for use in ameliorating effects of aging in a mammal, including any or all of the age-related effects described above.
BRIEF DESCRIPTION OF DRAWINGS
FIG. 1 is a plot of bodyweight (g) as measured by Hologic DEXA (y-axis) vs bodyweight measured directly using an electronic balance. A total of 667 paired measurements are plotted. b(0)=0.789; b(1)=1.022 and r 2 =0.9998.
FIG. 2 is a plot of average total bodyweight (g; y-axis) vs time (months; x-axis) for intact rats (non-ovariectomized) over the 10-month period of the experiments: , tall cage, treated animals; ▪, tall cage, untreated animals; ▴, low cage, treated animals; and ▾, low cage, untreated animals. The error bars represent standard error, for this and all other figures. Treatment began after two months (downward arrow; 63 days) and, as the rats were about 5 months of age at t=0, the animals aged from about 5 to about 15 months over the 10-month period of the experiments. Each point represents the average of the results obtained with eight rats.
FIG. 3 is a plot of average total bodyweight (g; y-axis) vs time (months; x-axis) for ovariectomized rats (downward arrow) as follows: , tall cage, treated animals; ▪, tall cage, untreated animals; ▴, low cage, treated animals; and ▾, low cage, untreated animals. As the rats were about 7 months of when treatment started (upward arrow), the animals aged from about 7 to about 15 months over the 8-month treatment period. Each point represents the average of the results obtained with nine rats, except in the case of treated rats in low cages, where there were ten rats.
FIG. 4 is a plot of body fat (g) (y-axis) vs time (month; x-axis) for intact rats over the 10-month period of the experiments: , tall cage, treated animals; ▪, tall cage, untreated animals; ▴, low cage, treated animals; and ▾, low cage, untreated animals.
FIG. 5 is a plot of body fat (g) (y-axis) vs time (month; x-axis) for ovariectomized rats over the 10-month period of the experiments: , tall cage, treated animals; ▪, tall cage, untreated animals; ▴, low cage, treated animals; and ▾, low cage, untreated animals.
FIG. 6A is a plot of average lean body mass (g; y-axis) vs time (months; x-axis) for intact rats housed in tall cages over the 10-month experimental period: , treated; and ▪, untreated.
FIG. 6B is a plot of average lean body mass (g; y-axis) vs time (months; x-axis) for intact rats housed in low cages over the 10-month experimental period: ▾, treated; and ▴, untreated.
FIG. 7A is a plot of average lean body mass (g; y-axis) vs time (months; x-axis) for ovariectomized rats housed in tall cages over the 10-month experimental period: , treated; and ▪, untreated.
FIG. 7B is a plot of average lean body mass (g; y-axis) vs time (months; x-axis) for ovariectomized rats housed in low cages over the 10-month experimental period: ▾, treated; and ▴, untreated.
FIG. 8 is a plot of average bone mineral content (g; y-axis) vs time (months; x-axis) for intact rats over the 10-month experimental period: , tall cage, treated animals; ▪, tall cage, untreated animals; ▾, low cage, treated animals; and ▴, low cage, untreated animals.
FIG. 9 is a plot of average bone mineral content (g; y-axis) vs time (months; x-axis) for ovariectomized rats over the 10-month experimental period: , tall cage, treated animals; ▪, tall cage, untreated animals; ▾, low cage, treated animals; and ▴, low cage, untreated animals.
FIG. 10 is a plot of percent change in average BMC/BW (y-axis) vs time (months; x-axis) for intact rats housed in tall cages over the 10-month experimental period: , treated; and ▪, untreated.
FIG. 11 is a plot of percent change in average BMC/BW (y-axis) vs time (months; x-axis) for intact rats housed in low cages over the 10-month experimental period: , treated; and ▪, untreated.
FIG. 12 is a plot of percent change in average BMC/BW (y-axis) vs time (months; x-axis) for ovariectomized rats housed in tall cages over the 8-month treatment period: , treated; and ▪, untreated.
FIG. 13 is a plot of percent change in average BMC/BW (y-axis) vs time (months; x-axis) for ovariectomized rats housed in low cages over the 8-month treatment period: , treated; and ▪, untreated.
FIG. 14 is a plot of percent change in average LBM/BW (y-axis) vs time (months; x-axis) for intact rats housed in tall cages over the 10-month experimental period: , treated; and ▪, untreated.
FIG. 15 is a plot of percent change in average LBM/BW (y-axis) vs time (months; x-axis) for intact rats housed in low cages over the 10-month experimental period: , treated; and ▪, untreated.
FIG. 16 is a plot of percent change in average LBM/BW (y-axis) vs time (months; x-axis) for ovariectomized rats housed in tall cages over the 8-month treatment period: , treated; and ▪, untreated.
FIG. 17 is a plot of percent change in average LBM/BW (y-axis) vs time (months; x-axis) for ovariectomized rats housed in low cages over the 8-month treatment period: , treated; and ▪, untreated.
FIG. 18 shows amino acid sequences of polypepude molecules representing a family of polypeptides expected to have the properties demonstrated for the polypeptide identified as SEQ ID NO:1. The sequences below the line would be expected not to show activity. See international patent publication No. WO 0075185.
DESCRIPTION OF PREFERRED EMBODIMENTS
A polypeptide having the amino acid sequence, Xaa 1 -Thr-GIn-Glu-His-Thr-Ala-Glu-Cys-Xaa 10 , where Xaa 1 is N-acetyl arginine and Xaa 10 is lysinamide (SEQ ID NO:1) was subject of preliminary testing as described below.
Experimental Procedures and Conditions
Experiments were conducted using female Sprague-Dawley rats that were about 5 months old at the beginning of the experiments. The rats were obtained from Vivarium of the University of Toronto, Mississauga, Ontario, Canada.
The rats were housed in pairs in either a standard shoebox cage 15 cm in height (low cage) or a cage with 22 cm height (tall cage). Humidity was maintained at 50%; temperature 22° C.; dark/light cycle of 12 hours. The rats were fed Standard Purina Rat Chow (unlimited daily supply) and tap water ad libitum.
Ovariectomies were performed under general isofluorane anaesthesia. A 1.5 cm dorsal midline incision was made. The skin and subcutaneous tissue were separated by blunt dissection. A small incision was made on either side in the posterior abdominal muscle wall (approximately 0.5 cm) to expose the ovaries. The ovaries were removed together with the proximal ends of the Fallopian tubes after the ligation of the ovarian arteries. The wounds in the abdominal muscle wall were not stitched. The dorsal skin wound was closed by three surgical wound clips. Tamgesic (0.2 ml) was given subcutaneously for the relief of pain immediately after the operation.
Body weight measurements were made by direct weighing with an electronic balance (to 0.01 g) and by DEXA measurement, Instrument: Hologic 4500A with program for regional measurement for small animals. The animals were scanned supine under general isofluorane anaesthesia. The whole body was scanned including the whole tail. The weights for the mineral content, the fat content and the lean body mass were summed to obtain total body weight.
Non-treated (control) animals were injected subcutaneously daily with 400 μL of 20 mM sodium acetate (pH 4.5) 5 days per week. Treated animals were injected subcutaneously with 300 nmoles per kg of body weight of the test polypeptide (SEQ ID NO:1) in 400 μL of 20 mM sodium acetate (pH 4.5) daily five days per week. The treatment period was nine months. The material, chemically synthesized, was obtained from the Protein DNA Core facility of Queen's University, Kingston, Ontario, Canada. Purification, by HPLC, indicated the test compound to be at least 95% pure.
Usefulness of DEXA for the Determination of Body Composition
DEXA measurements were evaluated as an indication of body composition. Through the attenuation of X-ray energy DEXA measurements provide an indication of the mass of various body tissues. In the Hologic DEXA instrument, the program measures the mass of bone tissue, fat and lean body mass (largely muscle mass). The sum of these measured masses represents total body mass. If this proposition is correct, then the total body mass measured by DEXA and measured directly by balance will be the same. Over the course of these experiments, 677 paired measurements of the body weight were made using the two methods. The results obtained (FIG. 1) indicate that there is a close relationship between the DEXA measurements and the measurements. It was thus concluded that body composition could be assessed using DEXA measurements.
Experimental Protocol
Eight groups of rats were treated as follows:
Tall cages:
Intact, untreated
8 rats
Intact, treated
8 rats
OVX, untreated
9 rats
OVX, treated
9 rats
Low cages:
Intact, untreated
8 rats
Intact, treated
8 rats
OVX, untreated
9 mts
OVX, treated
10 rats
Ovariectomies were performed at the age of 5 months. The ovariectomized animals were allowed to lose bone for two months following ovariectomy before the treatment began. A baseline measurement was made immediately prior to operation. Another pretreatment baseline measurement was made at the beginning of treatment, i.e. two months after ovariectomization. Measurements were made approximately monthly thereafter. At the end of the experiments, all animals were sacrificed by carbon dioxide narcosis.
Procedures were carried out according to the following schedule:
Day
Procedure
1, 2
Ovariectomy, baseline DEXA and weighing
63
Pretreatment base line DEXA and weighing
95
DEXA and weighing
126
DEXA and weighing
160
DEXA and weighing
191
DEXA and weighing
223
DEXA and weighing
255
DEXA and weighing
286
DEXA and weighing
318
DEXA and weighing
349
Animal sacrifice
Results and Discussion
Results obtained were analyzed to determine the correlation between controlled parameter and observed measurements, as described below.
Effect of Cage Height, Ovariectomization and Polypeptide on Total Body Weight
All animal groups experienced a gain in overall body weight over the 10-month experimental period from 5 to 15 months of age, as shown in FIG. 2 . The gain was most pronounced from 5 to 7 months of age, i.e., the first two months of the experimental period. After that, the observed weight gain slowed and, more or less, leveled off by the age of 13 months.
Effect of Ovariectomy on Body Weight
Ovariectomized rats gained weight more rapidly than intact rats, particularly during the first two months following the operation. The gain during this time period was about 100 g or more, as shown in FIGS. 2 and 3.
Effect of Cage Height on Body Weight
For intact rats subject to otherwise similar conditions, those housed in the taller cages experienced lower overall weight gain than those housed in the shorter cages, as shown in FIG. 2 . In the case of ovariectomized rats, cage height had a relatively small effect, as shown in FIG. 3 .
Effect of Polypeptide Treatment on Total Body Weight Gain
Intact rats treated with the polypeptide (SEQ ID NO:1) experienced a lower age-related gain in total body weight, as shown in FIG. 2 . The relative decrease was not largely affected by a change in cage height, a condition which permits greater physical activity on the part of the rats. As described below, the observed reduction in overall weight gain was largely at the expense of a gain in weight due to fat.
Ovariectomized rats treated with the polypeptide experienced a relative decrease in overall weight gain, although the effect seemed to be smaller than that observed for intact rats, as shown in FIG. 3 .
Effect of Polypeptide Treatment on Body Fat Content
Body fat content, expressed grams was determined and plotted as function of time. See FIGS. 4 and 5.
In the case of intact rats not treated with the polypeptide, an increase in fat content was observed as the rats aged and the increase was relatively independent of the height of cages in which the rats were housed, although a small reduction in fat gain was observed for rats housed in tall cages. See FIGS. 4 and 5.
For intact rats treated with the polypeptide, the increase in fat content was reduced in comparison to the untreated (control) rats, and the reduction appeared to be greatest for rats housed in tall cages.
During the first two months following ovariectomization, there was relatively rapid gain in body fat, as can be seen in FIG. 5 . During the treatment period (from seven to fifteen months of age of the rats), the change in fat content observed in the untreated ovariectomized rats was similar to that observed in the intact rats. Ovariectomized rats treated with the polypeptide experienced a significantly smaller increase in body fat content when housed in taller cages, and less so when housed in low cages, as shown in FIG. 5 .
Effect of Polypeptide Treatment on Lean Body Mass
A relatively small change in lean body mass was observed for all groups of rats over the 10-month experimental period, as shown in FIGS. 6A to 7 B.
Effect of Polypeptide Treatment on Bone Mineral Content
An age-related gain in bone mineral content was observed for all groups of rats over the 10-month experimental period. The BMC gain was very pronounced for the first two months, leveling by about eighth to ninth months of the experiment (13 to 14 months of age). See FIGS. 8 and 9.
Cage height appeared to have a relatively small influence on bone mineral content.
Ovariectomized rats appeared to experience a greater increase bone mineral content with age than the intact rats. This appears to be in contrast with that observed in human beings, in which total body mineral content has been observed to decrease after menopause.
An attenuation of the increase in bone mineral content was observed for rats treated with the polypeptide, for both intact and ovariectomized rats, as shown in FIGS. 8 and 9.
Bone Mineral Content and Body Weight
The percent change in the ratio of BMC/BW as a function of time was plotted. See FIGS. 10 to 13 .
As can be seen in FIGS. 10 and 11, there was a decrease in the BMC/BW ratio with time for intact rats, and the decrease was similar for rats housed in both types of cages. The BMC/BW ratio changed much less for those rats that were treated with the polypeptide.
As can be seen in FIGS. 12 and 13, there was a similar decrease in the BMC/BW ratio with time for ovariectomized rats, compared to the intact rats, and again the decrease was similar for rats housed in both types of cages. In the case of ovariectomized rats, however, the attenuating effect of polypeptide treatment appeared to be less pronounced.
Polypeptide treatment thus appears to ameliorate the effect of aging on the BMC/BW ratio. Insofar as it would be expected that an increase in the BMC/BW ratio would provide a benefit, by increasing the relative load-bearing capacity of the bone than would be otherwise, this would appear to be a salutary effect of polypeptide treatment.
Lean Body Mass and Body Weight
The percent change in the ratio of LBM/BW as a function of time was plotted. See FIGS. 14 to 17 .
As can be seen in FIGS. 14 and 15, there was a decrease in the LBM/BW ratio with time for intact rats, and the decrease was similar for rats housed in both types of cages. The LBM/BW ratio changed much less for those rats that were treated with the polypeptide.
As can be seen in FIGS. 16 and 17, there was a greater decrease in the LBM/BW ratio with time for ovariectomized rats, compared to intact rats. Again, however, the decrease was similar for rats housed in both types of cages. The attenuating effect of polypeptide treatment on the change in LBM/BW ratio over time appeared to be greater for intact rats than it was for ovariectomized rats.
The major component of lean body mass is muscle. Polypeptide treatment appears to ameliorate the effect of aging on the LBM/BW ratio. Insofar as it would be expected that an increase in the LBM/BW ratio would provide a benefit, by increasing the body muscle content than would be otherwise the case, this would appear to be a salutary effect of polypeptide treatment.
List of Abbreviations
BMC
Bone mineral content
BW
Body weight
DEXA
Dual-energy X-ray absorptiometry
LBM
Lean body mass
OVX
Ovariectomized rat
As indicated above, the test polypeptide (SEQ ID NO:1) is a 10-mer, protected at both ends and having the following amino acid sequence:
Xaa Thr Gln Glu His Thr Ala Glu Cys Xaa
wherein Xaa in the first position is N-acetyl arginine and Xaa in the tenth position is lysinamide.
Also part of this invention is use of any of the family of polypeptides set out as follows in FIG. 18, and identified as SEQ ID NOs:2 to 20.
A “variant” of a specific polypeptide disclosed herein refers to an amino acid sequence that is altered with respect to the specifically disclosed sequence by one or more amino acids. The variant may have “conservative” changes, wherein a substituted amino acid has similar structural or chemical properties, e.g., replacement of leucine with isoleucine. Typical such substitutions are among Ala, Val, Leu and lie; among Ser and Thr, among the acidic residues Asp and Glu; among Asn and Gln; and among the basic residues Lys and Arg; or aromatic residues Phe and Tyr. A variant of a polypeptide may be a naturally occurring such as an allelic variant, or it may be a variant that is not known to occur naturally. Non-naturally occurring variants of polypeptides may be made by mutagenesis techniques, by direct synthesis; and by other recombinant methods known to skilled artisans. Similar minor variations may also include amino acid deletions or insertions, or both. Further guidance in determining which amino acid residues may be substituted, inserted, or deleted without abolishing biological or immunological activity may be found using computer programs well known in the art, for example, DNASTAR software.
Included as part of this invention are use of polypeptides that contain such conservatively substituted variants of any of SEQ ID NOs:1 to 20. Of course the cysteine residue occupying the position numbered thirteen in SEQ ID NO:2 can be replaced by any of alanine, tyrosine, and serine, as activity of the polypeptide is conserved when such a substitution is made.
Also shown in the lower portion of FIG. 18 is a series of polypeptides each of which were found in the past to lack bone stimulatory activity and so would be expected to lack the utility of this invention. Such information provides guidance to a skilled person when designing variant polypeptides of those explicitly shown as SEQ ID NOs:1 to 20. This is particularly useful for obtaining active fragments of the largest polypeptide sequences, SEQ ID NOs:2 and 3.
A more complete description of the activity of the sequences shown in FIG. 18 is given in: international patent application No. PCT/CA00/00673 published under WO 0075185 Dec. 14, 2000; international patent application No. PCT/CA97/00967 published under WO9826070 Jun. 18, 1998; international patent application No. PCT/CA00100673 published under WO 0075185 Dec. 14, 2000; international patent application No. PCT/CA96/00401 published under WO 009640909 Dec. 19, 1996; and international patent application No. PCT/CA94/00144 published under WO 9420615 on Sep. 15, 1994. The specification of each of these documents is incorporated herein by reference.
In addition to polypeptides consisting only of naturally-occurring amino acids, the present invention includes peptidomimetics. Peptide analogs are commonly used in the pharmaceutical industry as non-peptide drugs with properties analogous to those of the template peptide. These types of non-peptide compound are termed “peptide mimetics” or “peptidomimetics” (Fauchere, J. (1986) Adv. Drug Res. 15: 29; Veber and Freidinger (1985) TINS p.392; and Evans et al. (1987) J. Med. Chem 30: 1229, which are incorporated herein by reference) and are usually developed with the aid of computerized molecular modeling. Peptide mimetics that are structurally similar to therapeutically useful peptides may be used to produce an equivalent therapeutic or prophylactic effect. Generally, peptidomimetics are structurally similar to a paradigm polypeptide (i.e., a polypeptide that has a biological or pharmacological activity), but have one or more peptide linkages optionally replaced by a linkage selected from the group consisting of: —CH 2 NH—, —CH 2 S—, —CH 2 CH 2 —, —CH═CH— (cis and trans), —COCH 2 —, —CH(OH)CH 2 —, and —CH 2 SO—, by methods known in the art and further described in the following references: Spatola, A. F. in “Chemistry and Biochemistry of Amino Acids, Peptides, and Proteins,” B. Weinstein, eds., Marcel Dekker, New York, p. 267 (1983); Spatola, A. F., Vega Data (March 1983), Vol. 1, Issue 3, “Peptide Backbone Modifications” (general review); Morley, J. S., Trends Pharm Sci (1980) pp. 463-468 (general review); Hudson, D. et al., Int J Pept Prot Res (1979) 14:177-185 (—CH 2 NH—, —CH 2 CH 2 —); Spatola, A. F. et al., Life Sci (1986) 38:1243-1249 (—CH 2 S—); Hann, M. M., J Chem Soc Perkin Trans I (1982) 307-314 (—CH═CH—, cis and trans); Almquist, R. G. et al., J Med Chem (1980) 23:1392-1398 (—COCH 2 —); Jennings-White, C. et al., Tetrahedron Lett (1982) 23:2533 (—COCH 2 —); Szelke, M. et al., European Appln. EP 45665 (1982) CA: 97:39405 (1982) (—CH(OH)CH 2 —); Holladay, M. W. et al., Tetrahedron Lett (1983) 24:4401-4404 (—C(OH)CH 2 —); and Hruby, V. J., Life Sci (1982) 31:189-199 (—CH 2 S—); each of which is incorporated herein by reference. A particularly preferred non-peptide linkage is —CH 2 NH—. Such peptide mimetics may have significant advantages over polypeptide embodiments, including, for example: more economical production, greater chemical stability, enhanced pharmacological properties (half-life, absorption, potency, efficacy, etc.), altered specificity (e.g., a broad-spectrum of biological activities), reduced antigenicity, and others. Labelling of peptidomimetics usually involves covalent attachment of one or more labels, directly or through a spacer (e.g., an amide group), to non-interfering position(s) on the peptidomimetic that are predicted by quantitative structure-activity data and/or molecular modeling. Such non-interfering positions generally are positions that do not form direct contacts with the macromolecules(s) (e.g., receptor molecules) to which the peptidomimetic binds to produce the therapeutic effect. Derivitization (e.g., labelling) of peptidomimetics should not substantially interfere with the desired biological or pharmacological activity of the peptidomimetic.
As discussed above, a polypeptide (or analogue thereof) of the present invention finds utility in the treatment of obesity as it relates to age related increase in body fat, or in modulation of body weight as it relates to reducing age related decrease in lean body mass.
The present invention includes utilities that extend to methods for measuring the presence and extent of a polypeptide of the invention in biological extracts (or samples) taken from a subject being treated for obesity or other condition for which the polypeptide has effect. In this way the level of the polypeptide being administered can be monitored in an individual, be it by a doctor, clinician, or even the subject, provided with a suitable diagnostic kit. A kit can include an antibody to the particular polypeptide or analogue thereof being administered. Generation of an antibody to a polypeptide having the amino acid sequence identified as SEQ ID NO:2 has previously been described, for example, in international patent application No. PCT/CA 94/00144 published under WO 94/20615 on Sep. 15, 1994. The antibody can thus be linked to or conjugated with any of several well known reporter systems set up to indicate positively binding of the polypeptide to the antibody. Well known reporter systems include radioimmuno assays (RIAs) or immunoradiometric assays (IRMAs). Alternatively, an enzyme-linked immunosorbent assay (ELISA) would have in common with RIAs and IRMAs a relatively high degree of sensitivity, but would generally not rely upon the use of radioisotopes. A visually detectable substance may be produced or at least one detectable in a spectrophotometer. An assay relying upon fluroescence of a substance bound by the enzyme being assayed could be used. It will be appreciated that there are a number of reporter systems which may be used, according to the present invention, to detect the presence of a particular polypeptide. With standardized sample collection and treatment, polypeptide presence below or above a threshold amount in blood serum, urine, or other sample can be determined. This in turn can be used in determining dosage levels, administration frequency, and other aspects of the treatment regimen.
Also included in the invention are the use of the polypeptides of the invention in competitive assays to identify or quantify molecules having receptor binding characteristics corresponding to those of said polypeptides. The polypeptides may be labelled, optionally with a radioisotope. A competitive assay can identify both antagonists and agonists of the relevant receptor.
The polypeptides and analogues of the invention have significant potential in the treatment of age related increase in fat, and/or reducing age related decrease in lean body mass. Preferably, a therapeutically effective amount of such an agent is administered in a pharmaceutically acceptable carrier, diluent, or excipient. The dosages and dosage regimen in which an agent is administered will vary according to the dosage form, mode of administration, the condition being treated and particulars of the patient being treated. Accordingly, optimal therapeutic concentrations will be best determined at the time and place through routine testing.
The agent can be delivered by intravenous, intraarterial, intraperitoneal, intramuscular, or subcutaneous routes of administration. Alternatively, the polypeptide, properly formulated, can be administered by nasal or oral administration. A constant supply of the agent can be ensured by providing a therapeutically effective dose (i.e., a dose effective to induce metabolic changes in a subject) at the necessary intervals, e.g., daily, every 12 hours, etc. These parameters will depend on the severity of the condition being treated, other actions, such as diet modification, that are implemented, the weight, age, and sex of the subject, and other criteria, which can be readily determined according to standard good medical practice by those of skill in the art.
The pharmaceutical forms suitable for injectable use include sterile aqueous solutions or dispersions and sterile powders for the extemporaneous preparation of sterile injectable solutions or dispersions. In all cases the form must be sterile and must be fluid to the extent that easy syringability exists. It must be stable under the conditions of manufacture and storage and must be preserved against the contaminating action of microorganisms, such as bacteria and fungi. The carrier can be a solvent or dispersion medium containing, for example, water, ethanol, polyol (for example, glycerol, propylene glycol, and liquid polyethylene glycol, and the like), suitable mixtures thereof, and vegetable oils. The proper fluidity can be maintained, for example, by the use of a coating, such as lecithin, by the maintenance of the required particle size in the case of dispersion and by the use of surfactants. The prevention of the action of microorganisms can be brought about by various antibacterial ad antifungal agents, for example, parabens, chlorobutanol, phenol, sorbic acid, thimerosal, and the like. In many cases, it will be preferable to include isotonic agents, for example, sugars or sodium chloride. Prolonged absorption of the injectable compositions can be brought about by the use in the compositions of agents delaying absorption, for example, aluminum monostearate and gelatin.
Sterile injectable solutions are prepared by incorporating the active compounds in the required amount in the appropriate solvent with various of the other ingredients enumerated above, as required, followed by filtered sterilization. Generally, dispersions are prepared by incorporating the various sterilized active ingredients into a sterile vehicle which contains the basic dispersion medium and the required other ingredients from those enumerated above. In the case of sterile powders for the preparation of sterile injectable solutions, the preferred methods of preparation are vacuum-drying and freeze-drying techniques which yield a powder of the active ingredient plus any additional desired ingredient from a previously sterile-filtered solution thereof.
Such preparations should contain at least 0.1% of active compound. The percentage of the compositions and preparations may, of course, be varied and may conveniently be between about 2 to about 60% of the weight of the unit. The amount of active compounds in such therapeutically useful compositions is such that a suitable dosage will be obtained.
The phrase “pharmaceutically acceptable” refers to molecular entities and compositions that are physiologically tolerable and do not typically produce an allergic or similarly untoward reaction, such as gastric upset, dizziness and the like, when administered to a human. Preferably, as used herein, the term “pharmaceutically acceptable” means approved by a regulatory agency of the federal or a state government or listed in the U.S. Pharmacopeia or other generally recognized pharmacopeia for use in animals, and more particularly in humans. The term “carrier” refers to a diluent, adjuvant, excipient, or vehicle with which the agent is administered. Such pharmaceutical carriers can be sterile liquids, such as water and oils, including those of petroleum, animal, vegetable or synthetic origin, such as peanut oil, soybean oil, mineral oil, sesame oil and the like. Suitable pharmaceutical carriers are described in Martin, Remington's Pharmaceutical Sciences, 18th Ed., Mack Publishing Co., Easton, Pa. (1990).
The compounds according to the invention can also be administered orally in solid dosage forms, which are described generally in Martin, Chapter 89, 1990. Solid dosage forms include tablets, capsules, pills, troches or lozenges, cachets or pellets. Also, liposomal or proteinoid encapsulation may be used to formulate the present compositions (as, for example, proteinoid microspheres reported in U.S. Pat. No. 4,925,673). Liposomal encapsulation may be used and the liposomes may be derivatized with various polymers (e.g., U.S. Pat. No. 5,013,556). A description of possible solid dosage forms for therapeutics is given by Marshall, in Modern Pharmaceutics, Chapter 10, Banker and Rhodes ed., (1979). In general, the formulation will include the polypeptide or analogue thereof of choice, and inert ingredients which allow for protection against the stomach environment, and release of the biologically active material in the intestine.
Also contemplated are oral dosage forms of the derivatized agents of the invention. The agent may be chemically modified so that oral delivery of the derivative is efficacious. Generally, the chemical modification contemplated is the attachment of at least one moiety to the peptide molecule itself, where said moiety permits (a) inhibition of amidolysis; and (b) uptake into the blood stream from the stomach or intestine. Also desired is the increase in overall stability of the polypeptide increase in circulation time in the body. Examples of such moieties include: polyethylene glycol, copolymers of ethylene glycol and propylene glycol, carboxymethyl cellulose, dextran, polyvinyl alcohol, polyvinyl pyrrolidone and polyproline. Abuchowski et al., “Soluble Polymer-Enzyme Adducts”, in Enzymes as Drugs, pp. 367-383, Holcenberg and Roberts, eds., Wiley-Interscience, New York, N.Y., (1981); Newmark et al., J. Appl. Biochem., 4:185-189 (1982). Other polymers that could be used are poly-1,3-dioxolane and poly-1,3,6-tioxocane. Preferred for pharmaceutical usage, as indicated above, are polyethylene glycol moieties.
For the agent (or derivative) the location of release may be the stomach, the small intestine (the duodenum, the jejunem, or the ileum), or the large intestine. One skilled in the art has available formulations which will not dissolve in the stomach, yet will release the material in the duodenum or elsewhere in the intestine. Preferably, the release will avoid the deleterious effects of the stomach environment, either by protection of the polypeptide or by release of the biologically active material beyond the stomach environment, such as in the intestine.
To ensure full gastric resistance, a coating impermeable to at least pH 5.0 is essential. Examples of the more common inert ingredients that are used as enteric coatings are cellulose acetate trimellitate (CAT), hydroxypropylmethylcellulose phthalate (HPMCP), HPMCP 50, HPMCP 55, polyvinyl acetate phthalate (PVAP), Eudragit L30D, Aquateric, cellulose acetate phthalate (CAP), Eudragit L, Eudragit S, and Shellac. These coatings may be used as mixed films.
A coating or mixture of coatings can also be used on tablets, which are not intended for protection against the stomach. This can include sugar coatings, or coatings which make the tablet easier to swallow. Capsules may consist of a hard shell (such as gelatin) for delivery of dry therapeutic i.e. powder, for liquid forms, a soft gelatin shell may be used. The shell material of cachets could be thick starch or other edible paper. For pills, lozenges, molded tablets or tablet triturates, moist massing techniques can be used.
The therapeutic can be included in the formulation as fine multiparticulates in the form of granules or pellets of particle size about 1 mm. The formulation of the material for capsule administration could also be as a powder, lightly compressed plugs or even as tablets. The therapeutic could be prepared by compression.
Colourants and flavouring agents may all be included. For example, the polypeptide (or analogue) may be formulated (such as by liposome or microsphere encapsulation) and then further contained within an edible product, such as a refrigerated beverage containing colorants and flavoring agents.
One can dilute or increase the volume of the therapeutic with an inert material. These diluents could include carbohydrates, especially mannitol, .alpha.-lactose, anhydrous lactose, cellulose, sucrose, modified dextrans and starch. Certain inorganic salts may be also be used as fillers including calcium triphosphate, magnesium carbonate and sodium chloride. Some commercially available diluents are Fast-Flo, Emdex, STA-Rx 1500, Emcompress and Avicell.
Disintegrants may be included in the formulation of the therapeutic into a solid dosage form. Materials used as disintegrants include but are not limited to starch including the commercial disintegrant based on starch, Explotab. Sodium starch glycolate, Amberlite, sodium carboxymethylcellulose, ultramylopectin, sodium alginate, gelatin, orange peel, acid carboxymethyl cellulose, natural sponge and bentonite may all be used. Another form of the disintegrants are the insoluble cationic exchange resins. Powdered gums may be used as disintegrants and as binders and these can include powdered gums such as agar, Karaya or tragacanth. Alginic acid and its sodium salt are also useful as disintegrants.
Binders may be used to hold the therapeutic agent together to form a hard tablet and include materials from natural products such as acacia, tragacanth, starch and gelatin. Others include methyl cellulose (MC), ethyl cellulose (EC) and carboxymethyl cellulose (CMC). Polyvinyl pyrrolidone (PVP) and hydroxypropylmethyl cellulose (HPMC) could both be used in alcoholic solutions to granulate the therapeutic.
An antifrictional agent may be included in the formulation of the therapeutic to prevent sticking during the formulation process. Lubricants may be used as a layer between the therapeutic and the die wall, and these can include but are not limited to: stearic acid including its magnesium and calcium salts, polytetrafluoroethylene (PTFE), liquid paraffin, vegetable oils and waxes. Soluble lubricants may also be used such as sodium lauryl sulfate, magnesium lauryl sulfate, polyethylene glycol of various molecular weights, and Carbowax 4000 and 6000.
Glidants that might improve the flow properties of the drug during formulation and to aid rearrangement during compression might be added. The glidants may include starch, talc, pyrogenic silica and hydrated silicoaluminate.
To aid dissolution of the therapeutic into the aqueous environment, a surfactant might be added as a wetting agent Surfactants may include anionic detergents such as sodium lauryl sulfate, dioctyl sodium sulfosuccinate and dioctyl sodium sulfonate. Cationic detergents might be used and could include benzalkonium chloride or benzethomium chloride. The list of potential nonionic detergents that could be included in the formulation as surfactants are lauromacrogol 400, polyoxyl 40 stearate, polyoxyethylene hydrogenated castor oil 10, 50 and 60, glycerol monostearate, polysorbate 40, 60, 65 and 80, sucrose fatty acid ester, methyl cellulose and carboxymethyl cellulose. These surfactants could be present in the formulation of the protein or derivative either alone or as a mixture in different ratios.
Additives which potentially enhance uptake of the polypeptide (or analogue) are for instance the fatty acids oleic acid, linoleic acid and linolenic acid.
Controlled release formulation may be desirable. The agent could be incorporated into an inert matrix which permits release by either diffusion or leaching mechanisms i.e., gums. Slowly degenerating matrices may also be incorporated into the formulation. Another form of a controlled release of this therapeutic is by a method based on the Oros therapeutic system (Alza Corp.), i.e. the drug is enclosed in a semipermeable membrane which allows water to enter and push the drug out through a single small opening due to osmotic effects. Some enteric coatings also have a delayed release effect.
Other coatings may be used for the formulation. These include a variety of sugars which could be applied in a coating pan. The agent could also be given in a film-coated tablet; the materials used in this instance are divided into 2 groups. The first are the nonenteric materials and include methyl cellulose, ethyl cellulose, hydroxyethyl cellulose, methylhydroxy-ethyl cellulose, hydroxypropyl cellulose, hydroxypropyl-methyl cellulose, sodium carboxy-methyl cellulose, providone and the polyethylene glycols. The second group consists of the enteric materials that are commonly esters of phthalic acid.
A mix of materials might be used to provide the optimum film coating. Film coating may be carried out in a pan coater or in a fluidized bed or by compression coating.
Systemic administration can also be by transmucosal or transdermal means. For transmucosal or transdermal administration, penetrants appropriate to the barrier to be permeated are used in the formulation. Such penetrants are generally known in the art, and include, for example, for transmucosal administration, detergents, bile salts, and fusidic acid derivatives. Transmucosal administration can be accomplished through the use of nasal sprays or suppositories. For transdermal administration, the active compounds are formulated into ointments, salves, gels, or creams as generally known in the art.
Also contemplated herein is pulmonary delivery of the polypeptide (or analogue thereof). The active agent is delivered to the lungs of a mammal while inhaling and traverses across the lung epithelial lining to the blood-stream. Other reports of this include Adjei et al., Pharmaceutical Research, 7(6):565-569 (1990); Adjei et al., International Journal of Pharmaceutics, 63:135-144 (1990) (leuprolide acetate); Braquet et al., Journal of Cardiovascular Pharmacology, 13(suppl. 5):143-146 (1989) (endothelin-1); Hubbard et al., Annals of Internal Medicine, 3(3):206-212 (1989) (.alpha.1-antitrypsin); Smith et al., J. Clin. Invest., 84:1145-1146 (1989) (.alpha.1-proteinase); Oswein et al., “Aerosolization of Proteins”, Proceedings of Symposium on Respiratory Drug Delivery II, Keystone, Colo., (March 1990) (recombinant human growth hormone); Debs et al., J. Immunol., 140:3482-3488 (1988) (interferon-γ and TNF-γ) and Platz et al., U.S. Pat. No. 5,284,656 (granulocyte colony stimulating factor). Contemplated for use in the practice of this invention are a wide range of mechanical devices designed for pulmonary delivery of therapeutic products, including but not limited to nebulizers, metered-dose inhalers, and powder inhalers, all of which are familiar to those skilled in the art.
Some specific examples of commercially available devices suitable for the practice of this invention are the Ultravent nebulizer, manufactured by Mallinckrodt, Inc., St. Louis, Mo.; the Acorn II nebulizer, manufactured by Marquest Medical Products, Englewood, Colo.; the Ventolin metered-dose inhaler, manufactured by Glaxo Inc., Research Triangle Park, N.C.; and the Spinhaler powder inhaler, manufactured by Fisons Corp., Bedford, Mass.
All such devices require the use of formulations suitable for the dispensing of polypeptide (or analogue). Typically, each formulation is specific to the type of device employed and may involve the use of an appropriate propellant material, in addition to the usual diluents, adjuvants and/or carriers useful in therapy. Also, the use of liposomes, microcapsules or microspheres, inclusion complexes, or other types of carriers is contemplated. Chemically modified polypeptide may also be prepared in different formulations depending on the type of chemical modification or the type of device employed.
Formulations suitable for use with a nebulizer, either jet or ultrasonic, will typically comprise the active agent dissolved in water at a concentration of about 0.1 to 25 mg of biologically active polypeptide per ml of solution. The formulation may also include a buffer and a simple sugar (e.g., for peptide stabilization and regulation of osmotic pressure). The nebulizer formulation may also contain a surfactant, to reduce or prevent surface induced aggregation of the peptide caused by atomization of the solution in forming the aerosol.
Formulations for use with a metered-dose inhaler device will generally comprise a finely divided powder containing the protein (or derivative) suspended in a propellant with the aid of a surfactant. The propellant may be any conventional material employed for this purpose, such as a chlorofluorocarbon, a hydrochlorofluorocarbon, a hydrofluorocarbon, or a hydrocarbon, including trichlorofluoromethane, dichlorodifluoromethane, dichlorotetrafluoroethanol, and 1,1,1,2-tetrafluoroethane, or combinations thereof. Suitable surfactants include sorbitan trioleate and soya lecithin. Oleic acid may also be useful as a surfactant.
Formulations for dispensing from a powder inhaler device will comprise a finely divided dry powder containing protein (or derivative) and may also include a bulking agent, such as lactose, sorbitol, sucrose, or mannitol in amounts which facilitate dispersal of the powder from the device, e.g., 50 to 90% by weight of the formulation. The polypeptide (or analogue) should most advantageously be prepared in particulate form with an average particle size of less than 10 microns, most preferably 0.5 to 5 microns, for most effective delivery to the distal lung.
Nasal delivery of the polypeptide protein (or analogue) is also contemplated. Nasal delivery allows the passage of the active agent to the blood stream directly after administering the therapeutic product to the nose, without the necessity for deposition of the product in the lung. Formulations for nasal delivery include those with dextran or cyclodextran.
In yet another aspect of the present invention, methods of treatment and manufacture of a medicament are provided for treatment the of conditions of age related increase in fat, and/or reducing age related decrease in lean body mass. Of course, insofar as the invention is useful in treating such conditions, the invention can be said to be a prophylactic treatment. Also, since the administration is not necessarily as a medicament, but could be as part of a food, the invention extends to methods of manufacture of a food for use in reducing age related increase in fat, and/or reducing age related decrease in lean body mass.
For a polypeptide (or analogue) of the present invention, as further studies are conducted, information will emerge regarding appropriate dosage levels for treatment of various conditions in various patients, and the ordinary skilled worker, considering the therapeutic context, age and general health of the recipient, will be able to ascertain the proper dosage. Generally, for injection or infusion, dosage will be between 0.01 micrograms of biologically active protein/kg body weight, (calculating the mass of the protein alone, without chemical modification), and 10 mg/kg (based on the same). The dosing schedule may vary, depending on the circulation half-life of the agent used, whether the polypeptide is delivered by bolus dose or continuous infusion, and the formulation used.
The phrase “therapeutically effective amount” is used herein to mean an amount sufficient to obtain the desired effect, according to the condition being treated.
Where a particular polypeptide or nucleic acid molecule is said to have a specific percent identity or conservation to a reference polypeptide or nucleic acid molecule, the percent identity or conservation can be determined by the algorithm of Myers and Miller, CABIOS (1989), which is embodied in the ALIGN program (version 2.0), or its equivalent, using a gap length penalty of 12 and a gap penalty of 4 where such parameters are required. All other parameters are set to their default positions. Access to ALIGN is readily available. See, e.g., http://www2.igh.cnrs.fr/bin/align-guess.cgi on the internet.
Comparison of the sequence to the data bases can be performed using BLAST (Altschcul, S. F. et al., J. Mol. Biol. 215:403-410 (1990)).
Parameters for polypeptide sequence comparison include the following: (1) Algorithm: Needleman and Wunsch, J. Mol Biol. 48: 443-453 (1970); (2) Comparison matrix: BLOSSUM62 from Hentikoff and Hentikoff, Proc. Natl. Acad. Sci. USA. 89:10915-10919 (1992); (3) Gap Penalty: 12; and (4) Gap Length Penalty: 4. A program useful with these parameters is publicly available as the “gap” program from Genetics Computer Group, Madison Wis. The aforementioned parameters are the default parameters for peptide comparisons (along with no penalty for end gaps).
Parameters for polynucleotide comparison include the following: (1) Algorithm: Needleman and Wunsch, J. Mol Biol. 48:443-453 (1970); (2) Comparison matrix: matches=+10, mismatch=0; (3) Gap Penalty: 50; and (4) Gap Length Penalty: 3. Available as: The “gap” program from Genetics Computer Group, Madison Wis. These are the default parameters for nucleic acid comparisons.
All references referred to herein are incorporated herein in there entirety.
63
1
10
PRT
Artificial Sequence
MOD_RES
(1)...(1)
Xaa is N-acetyl arginine
1
Xaa Thr Gln Glu His Thr Ala Glu Cys Xaa
1 5 10
2
36
PRT
Homo sapiens
2
Gly Ile Gly Lys Arg Thr Asn Glu His Thr Ala Asp Cys Lys Ile Lys
1 5 10 15
Pro Asn Thr Leu His Lys Lys Ala Ala Glu Thr Leu Met Val Leu Asp
20 25 30
Gln Asn Gln Pro
35
3
36
PRT
Artificial Sequence
Description of Artificial Sequence Chemically
synthesized polypeptide
3
Gly Ile Gly Lys Arg Thr Asn Glu His Thr Ala Asp Ala Lys Ile Lys
1 5 10 15
Pro Asn Thr Leu His Lys Lys Ala Ala Glu Thr Leu Met Val Leu Asp
20 25 30
Gln Asn Gln Pro
35
4
30
PRT
Homo sapiens
4
Gly Ile Gly Lys Arg Thr Asn Glu His Thr Ala Asp Cys Lys Ile Lys
1 5 10 15
Pro Asn Thr Leu His Lys Lys Ala Ala Glu Thr Leu Met Val
20 25 30
5
25
PRT
Homo sapiens
5
Gly Ile Gly Lys Arg Thr Asn Glu His Thr Ala Asp Cys Lys Ile Lys
1 5 10 15
Pro Asn Thr Leu His Lys Lys Ala Ala
20 25
6
20
PRT
Homo sapiens
6
Gly Ile Gly Lys Arg Thr Asn Glu His Thr Ala Asp Cys Lys Ile Lys
1 5 10 15
Pro Asn Thr Leu
20
7
15
PRT
Homo sapiens
7
Gly Ile Gly Lys Arg Thr Asn Glu His Thr Ala Asp Cys Lys Ile
1 5 10 15
8
14
PRT
Homo sapiens
8
Gly Ile Gly Lys Arg Thr Asn Glu His Thr Ala Asp Cys Lys
1 5 10
9
10
PRT
Homo sapiens
9
Arg Thr Asn Glu His Thr Ala Asp Cys Lys
1 5 10
10
10
PRT
Homo sapiens
MOD_RES
(1)...(1)
Xaa is N-acetyl arginine
10
Xaa Thr Asn Glu His Thr Ala Asp Cys Xaa
1 5 10
11
10
PRT
Artificial Sequence
MOD_RES
(1)...(1)
Xaa is N-acetyl arginine
11
Xaa Thr Asn Glu His Thr Ala Glu Cys Xaa
1 5 10
12
10
PRT
Artificial Sequence
MOD_RES
(1)...(1)
Xaa is N-acetyl arginine
12
Xaa Thr Gln Glu His Thr Ala Asp Cys Xaa
1 5 10
13
10
PRT
Artificial Sequence
MOD_RES
(1)...(1)
Xaa is N-acetyl arginine
13
Xaa Ala Asn Glu His Thr Ala Asp Cys Xaa
1 5 10
14
10
PRT
Artificial Sequence
MOD_RES
(1)...(1)
Xaa is N-acetyl arginine
14
Xaa Thr Ala Glu His Thr Ala Asp Cys Xaa
1 5 10
15
10
PRT
Artificial Sequence
MOD_RES
(1)...(1)
Xaa is N-acetyl arginine
15
Xaa Thr Asn Glu His Ala Ala Asp Cys Xaa
1 5 10
16
10
PRT
Artificial Sequence
MOD_RES
(1)...(1)
Xaa is N-acetyl arginine
16
Xaa Thr Asn Glu His Thr Gly Asp Cys Xaa
1 5 10
17
10
PRT
Artificial Sequence
MOD_RES
(1)...(1)
Xaa is N-acetyl arginine
17
Xaa Thr Asn Glu His Thr Ala Asp Tyr Xaa
1 5 10
18
10
PRT
Artificial Sequence
MOD_RES
(1)...(1)
Xaa is N-acetyl arginine
18
Xaa Thr Gln Glu His Thr Ala Glu Ala Xaa
1 5 10
19
10
PRT
Artificial Sequence
MOD_RES
(1)...(1)
Xaa is N-acetyl arginine
19
Xaa Thr Gln Glu His Thr Ala Glu Tyr Xaa
1 5 10
20
10
PRT
Artificial Sequence
MOD_RES
(1)...(1)
Xaa is N-acetyl arginine
20
Xaa Thr Gln Glu His Thr Ala Glu Ser Xaa
1 5 10
21
16
PRT
Homo sapiens
21
Leu His Lys Lys Ala Ala Glu Thr Leu Met Val Leu Asp Gln Asn Gln
1 5 10 15
22
15
PRT
Homo sapiens
22
Leu His Lys Lys Ala Ala Glu Thr Leu Met Val Leu Asp Gln Asn
1 5 10 15
23
14
PRT
Homo sapiens
23
Leu His Lys Lys Ala Ala Glu Thr Leu Met Val Leu Asp Gln
1 5 10
24
13
PRT
Homo sapiens
24
Leu His Lys Lys Ala Ala Glu Thr Leu Met Val Leu Asp
1 5 10
25
23
PRT
Homo sapiens
25
Thr Ala Asp Cys Lys Ile Lys Pro Asn Thr Leu His Lys Lys Ala Ala
1 5 10 15
Glu Thr Leu Met Val Leu Asp
20
26
30
PRT
Homo sapiens
26
Arg Thr Asn Glu His Thr Ala Asp Cys Lys Ile Lys Pro Asn Thr Leu
1 5 10 15
His Lys Lys Ala Ala Glu Thr Leu Met Val Leu Asp Gln Asn
20 25 30
27
11
PRT
Homo sapiens
27
Arg Thr Asn Glu His Thr Ala Asp Cys Lys Ile
1 5 10
28
10
PRT
Artificial Sequence
MOD_RES
(1)...(1)
Xaa is N-acetyl alanine
28
Xaa Thr Asn Glu His Thr Ala Asp Cys Xaa
1 5 10
29
10
PRT
Artificial Sequence
MOD_RES
(1)...(1)
Xaa is N-acetyl arginine
29
Xaa Thr Asn Ala His Thr Ala Asp Cys Xaa
1 5 10
30
10
PRT
Artificial Sequence
MOD_RES
(1)...(1)
Xaa is N-acetyl arginine
30
Xaa Thr Asn Glu Ala Thr Ala Asp Cys Xaa
1 5 10
31
10
PRT
Artificial Sequence
MOD_RES
(1)...(1)
Xaa is N-acetyl arginine
31
Xaa Thr Asn Glu His Thr Ala Ala Cys Xaa
1 5 10
32
10
PRT
Artificial Sequence
MOD_RES
(1)...(1)
Xaa is N-acetyl arginine
32
Xaa Thr Asn Glu His Thr Ala Asp Cys Xaa
1 5 10
33
36
PRT
Homo sapiens
MOD_RES
(1)...(1)
Xaa is N-acetyl glycine
33
Xaa Ile Gly Lys Arg Thr Asn Glu His Thr Ala Asp Cys Lys Ile Lys
1 5 10 15
Pro Asn Thr Leu His Lys Lys Ala Ala Glu Thr Leu Met Val Leu Asp
20 25 30
Gln Asn Gln Pro
35
34
10
PRT
Artificial Sequence
Description of Artificial Sequence Chemically
synthesized polypeptide
34
Arg Thr Asn Glu His Thr Ala Glu Cys Lys
1 5 10
35
10
PRT
Artificial Sequence
Description of Artificial Sequence Chemically
synthesized polypeptide
35
Arg Thr Gln Glu His Thr Ala Glu Cys Lys
1 5 10
36
10
PRT
Artificial Sequence
Description of Artificial Sequence Chemically
synthesized polypeptide
36
Arg Thr Gln Glu His Thr Ala Asp Cys Lys
1 5 10
37
10
PRT
Artificial Sequence
Description of Artificial Sequence Chemically
synthesized polypeptide
37
Arg Ala Asn Glu His Thr Ala Asp Cys Lys
1 5 10
38
10
PRT
Artificial Sequence
Description of Artificial Sequence Chemically
synthesized polypeptide
38
Arg Thr Ala Glu His Thr Ala Asp Cys Lys
1 5 10
39
10
PRT
Artificial Sequence
Description of Artificial Sequence Chemically
synthesized polypeptide
39
Arg Thr Asn Glu His Ala Ala Asp Cys Lys
1 5 10
40
10
PRT
Artificial Sequence
Description of Artificial Sequence Chemically
synthesized polypeptide
40
Arg Thr Asn Glu His Thr Gly Asp Cys Lys
1 5 10
41
10
PRT
Artificial Sequence
Description of Artificial Sequence Chemically
synthesized polypeptide
41
Arg Thr Asn Glu His Thr Ala Asp Tyr Lys
1 5 10
42
10
PRT
Artificial Sequence
Description of Artificial Sequence Chemically
synthesized polypeptide
42
Arg Thr Gln Glu His Thr Ala Glu Ala Lys
1 5 10
43
10
PRT
Artificial Sequence
Description of Artificial Sequence Chemically
synthesized polypeptide
43
Arg Thr Gln Glu His Thr Ala Glu Tyr Lys
1 5 10
44
10
PRT
Artificial Sequence
Description of Artificial Sequence Chemically
synthesized polypeptide
44
Arg Thr Gln Glu His Thr Ala Glu Ser Lys
1 5 10
45
108
DNA
Homo sapiens
CDS
(1)...(108)
45
ggg atc gga aaa cga aca aat gaa cat acg gca gat tgt aaa att aaa 48
Gly Ile Gly Lys Arg Thr Asn Glu His Thr Ala Asp Cys Lys Ile Lys
1 5 10 15
ccg aac acc ttg cat aaa aaa gct gca gag act tta atg gtc ctt gac 96
Pro Asn Thr Leu His Lys Lys Ala Ala Glu Thr Leu Met Val Leu Asp
20 25 30
caa aat gaa cca 108
Gln Asn Gln Pro
35
46
108
DNA
Homo sapiens
CDS
(1)...(108)
46
ggg atc gga aaa cga aca aat gaa cat acg gca gat gca aaa att aaa 48
Gly Ile Gly Lys Arg Thr Asn Glu His Thr Ala Asp Ala Lys Ile Lys
1 5 10 15
ccg aac acc ttg cat aaa aaa gct gca gag act tta atg gtc ctt gac 96
Pro Asn Thr Leu His Lys Lys Ala Ala Glu Thr Leu Met Val Leu Asp
20 25 30
caa aat gaa cca 108
Gln Asn Gln Pro
35
47
90
DNA
Homo sapiens
CDS
(1)...(90)
47
ggg atc gga aaa cga aca aat gaa cat acg gca gat tgt aaa att aaa 48
Gly Ile Gly Lys Arg Thr Asn Glu His Thr Ala Asp Cys Lys Ile Lys
1 5 10 15
ccg aac acc ttg cat aaa aaa gct gca gag act tta atg gtc 90
Pro Asn Thr Leu His Lys Lys Ala Ala Glu Thr Leu Met Val
20 25 30
48
75
DNA
Homo sapiens
CDS
(1)...(75)
48
ggg atc gga aaa cga aca aat gaa cat acg gca gat tgt aaa att aaa 48
Gly Ile Gly Lys Arg Thr Asn Glu His Thr Ala Asp Cys Lys Ile Lys
1 5 10 15
ccg aac acc ttg cat aaa aaa gct gca 75
Pro Asn Thr Leu His Lys Lys Ala Ala
20 25
49
60
DNA
Homo sapiens
CDS
(1)...(60)
49
ggg atc gga aaa cga aca aat gaa cat acg gca gat tgt aaa att aaa 48
Gly Ile Gly Lys Arg Thr Asn Glu His Thr Ala Asp Cys Lys Ile Lys
1 5 10 15
ccg aac acc ttg 60
Pro Asn Thr Leu
20
50
45
DNA
Homo sapiens
CDS
(1)...(45)
50
ggg atc gga aaa cga aca aat gaa cat acg gca gat tgt aaa att 45
Gly Ile Gly Lys Arg Thr Asn Glu His Thr Ala Asp Cys Lys Ile
1 5 10 15
51
42
DNA
Homo sapiens
CDS
(1)...(42)
51
ggg atc gga aaa cga aca aat gaa cat acg gca gat tgt aaa 42
Gly Ile Gly Lys Arg Thr Asn Glu His Thr Ala Asp Cys Lys
1 5 10
52
30
DNA
Homo sapiens
CDS
(1)...(30)
52
cga aca aat gaa cat acg gca gat tgt aaa 30
Arg Thr Asn Glu His Thr Ala Asp Cys Lys
1 5 10
53
30
DNA
Artificial Sequence
CDS
(1)...(30)
Description of Artificial Sequence Chemically
synthesized nucleotide
53
cga aca aat gaa cat acg gca gaa tgt aaa 30
Arg Thr Asn Glu His Thr Ala Glu Cys Lys
1 5 10
54
30
DNA
Artificial Sequence
CDS
(1)...(30)
Description of Artificial Sequence Chemically
synthesized nucleotide
54
cga aca caa gaa cat acg gca gaa tgt aaa 30
Arg Thr Gln Glu His Thr Ala Glu Cys Lys
1 5 10
55
30
DNA
Artificial Sequence
CDS
(1)...(30 )
Description of Artificial Sequence Chemically
synthesized nucleotide
55
cga aca caa gaa cat acg gca gat tgt aaa 30
Arg Thr Gln Glu His Thr Ala Asp Cys Lys
1 5 10
56
30
DNA
Artificial Sequence
CDS
(1)...(30)
Description of Artificial Sequence Chemically
synthesized nucleotide
56
cga gca aat gaa cat acg gca gat tgt aaa 30
Arg Ala Asn Glu His Thr Ala Asp Cys Lys
1 5 10
57
30
DNA
Artificial Sequence
CDS
(1)...(30)
Description of Artificial Sequence Chemically
synthesized nucleotide
57
cga aca gca gaa cat acg gca gat tgt aaa 30
Arg Thr Ala Glu His Thr Ala Asp Cys Lys
1 5 10
58
30
DNA
Artificial Sequence
CDS
(1)...(30)
Description of Artificial Sequence Chemically
synthesized nucleotide
58
cga aca aat gaa cat gca gca gat tgt aaa 30
Arg Thr Asn Glu His Ala Ala Asp Cys Lys
1 5 10
59
30
DNA
Artificial Sequence
CDS
(1)...(30)
Description of Artificial Sequence Chemically
synthesized nucleotide
59
cga aca aat gaa cat aca ggg gat tgt aaa 30
Arg Thr Asn Glu His Thr Gly Asp Cys Lys
1 5 10
60
30
DNA
Artificial Sequence
CDS
(1)...(30)
Description of Artificial Sequence Chemically
synthesized nucleotide
60
cga aca aat gaa cat aca gca gat tat aaa 30
Arg Thr Asn Glu His Thr Ala Asp Tyr Lys
1 5 10
61
30
DNA
Artificial Sequence
CDS
(1)...(30)
Description of Artificial Sequence Chemically
synthesized nucleotide
61
cga aca caa gaa cat aca gca gaa gca aaa 30
Arg Thr Gln Glu His Thr Ala Glu Ala Lys
1 5 10
62
30
DNA
Artificial Sequence
CDS
(1)...(30)
Description of Artificial Sequence Chemically
synthesized nucleotide
62
cga aca caa gaa cat aca gca gaa tat aaa 30
Arg Thr Gln Glu His Thr Ala Glu Tyr Lys
1 5 10
63
30
DNA
Artificial Sequence
CDS
(1)...(30)
Description of Artificial Sequence Chemically
synthesized nucleotide
63
cga aca caa gaa cat aca gca gaa tct aaa 30
Arg Thr Gln Glu His Thr Ala Glu Ser Lys
1 5 10
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Method of ameliorating effects of aging in an animal, the method comprising administering to the animal an effective amount of a synthetic polypeptide comprising an amino acid sequence that has 10+q amino acids, wherein, under physiological conditions, residues numbered n, n+4, n+9 are positively charged amino acids, residues numbered n+3, n+7 are negatively charged amino acids, wherein the remaining amino acids are nonpolar amino acids or uncharged polar amino acids, wherein n is an integer from 1 to 1+q and q is a whole number greater than or equal to zero. Experiments demonstrating the effect were performed with a polypeptide having the sequence Arg-Thr-Gln-Glu-His-Thr-Ala-Glu-Cys-Lys.
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This application is the national phase under 35 U.S.C. § 371 of PCT International Application No. PCT/EP01/09069 which has an International filing date of Aug. 6, 2001, which designated the United States of America and which claims priority on European Patent Application number EP 00117708.8 filed Aug. 17, 2000, the entire contents of which are hereby incorporated herein by reference.
FIELD OF THE INVENTION
The invention generally relates to a diagnostic method for the detection of ageing phenomena in a steam turbine.
BACKGROUND OF THE INVENTION
Steam turbines in current generation, in combined-cycle operation and in the chemical industry are expected to have a high degree of availability. If changes to a steam turbine occur which reduce efficiency and, if appropriate, cause a shutdown, this leads to high outage and consequential costs. An early diagnosis of imminent changes to the machine parts of a steam turbine allows conditioned-oriented maintenance planning and thus reduces the operating costs.
An essential information source for assessing the availability and viability of a steam turbine is the knowledge of the condition of those components of the steam turbine around which or through which steam flows during operation. Thus, operators fear, for example, deposits in steam turbines, since these, in addition to reducing the power output and efficiency, may entail an overloading of individual components which is harmful to the plant.
Depending on the type of construction and the field of use, every steam turbine, as a system, exhibits a typical thermodynamic behavior. If the thermodynamic behavior of a steam turbine changes due to faults occurring on components around which steam flows, it is appropriate to detect these changes in relation to normal behavior, so that damage avoidance or at least damage limitation can be put into effect at an early stage. The thermodynamic behavior of a steam turbine is influenced in use, for example, by erosion and corrosion, contamination (for example, by salt deposits), seal wear for example, on sealing strips), thermal deformation (for example, due to the maximum temperature limit being exceeded) and foreign body damage (for example, by impacts of welding beads on the blading).
It must be assumed that the aging phenomena listed above are always accompanied by an impairment in turbine efficiency and steam throughput during the operation of a steam turbine. Impairments in efficiency therefore not only equate to a lower utilization of the energy supplied to the steam turbine, but are also often an early indication of possible damage to steam turbine components around which steam flows. The same also applies to the steam throughput through a steam turbine. A deteriorating steam throughput under identical operating conditions, that is to say with an identical fresh steam pressure, identical inlet valve position and identical turbine rotational speed, likewise points to aging phenomena in the steam turbines.
The customary way of monitoring a steam turbine is to observe the operational indicators for conspicuous readings. This monitoring system has been refined by means of additional measurements of state variables, such as, for example, pressure and temperature at various points in the steam turbine. A further method for the early detection of aging phenomena on a steam turbine is to compare the current operating behavior with the theoretical operating behavior derived from the design of the steam turbine. The basis for this is mathematical models which are adopted from the design of the steam turbine plant and reproduce the thermodynamic behavior of the steam turbine.
Urban, L.A.: “ Gas Path Analysis applied turbine engine condition monitoring ”, AIAA Paper 72-1082, New Orleans, 1972, Fiedler, K., Lunderstädt, R.: “ Diagnoseverfahren für RUSTON Gasturbine” [“Diagnostic Method for RUSTON Gas Turbines ”], first part report, Gesellschaft für Forschung und Entwicklung mbH, Hamburg, 1985, and Lunderstäidt, R., Fiedler, K.: “ Thernodynamische Zustandsdiagnose an Strömungsmaschinen” [“Thermodynamic Condition Diagnosis on Turbomachines”], yearbook 1992 of VDI Gesellschaft Energietechnik, VDI-Verlag, p. 160-178, Düsseldorf 1992, disclose a diagnostic method for aircraft turbine engines, in which state variables, such has the pressure and temperature of the gas turbine, are measured and diagnostic functions are calculated from these, it being possible to draw conclusions as to the aging of the gas turbine from the development in time of these diagnostic functions. The fluidic monitoring principle used there, which is known as gas path analysis, is based on a mathematical modeling of the flow processes in a gas turbine. The modeling principle forms the flowpath theory known in fluid mechanics.
This method has not been used for steam turbines, however, since the method was developed especially for gas turbines and gas turbines differ fundamentally in their form of construction from steam turbines.
SUMMARY OF THE INVENTION
An object of an embodiment of the present invention is, therefore, to specify a diagnostic method, improved in relation to the prior art, for the detection of aging phenomena on a steam turbine.
An object may be achieved by a diagnostic method for the detection of aging phenomena in a steam turbine, in which method, according to an embodiment of the invention, the efficiency and/or the steam throughput coefficient of the steam turbine are/is calculated from measurements of state variables of the steam turbine at a first and a later second time point at a plurality of operating points of the steam turbine. Further, an operating point is determined in each case by a value of the parameters circumferential Mach number, pressure number and inlet valve position. Finally, the extent of the aging of the steam turbine is concluded from the change in efficiency and/or in steam throughput coefficient from the first to the second time point as a function of the operating point.
In the first place, the steam pressures, steam temperatures and steam quantity flows are available from the monitoring of a steam turbine by measurement which, being numerical values, do not make it possible to have direct information on the condition of a turbine. However, the efficiency of the steam turbine and the steam throughflow through the steam turbine (referred to hereafter as the steam throughput coefficient) can be calculated from these directly measurable state variables. Since aging phenomena change the thermodynamic behavior of a turbine, the efficiency and the steam throughput coefficient are also impaired by aging phenomena, since they are in direct relation to the thermodynamic behavior of the steam turbine. An embodiment of the invention, then, is based on the notion that conclusions can be drawn from the efficiency and the steam throughput coefficient of a steam turbine as to the aging condition of the latter, and consequently as to deposits, erosion and corrosion, foreign body damage and wear.
Measurement technology on steam turbines makes available thermodynamic state variables, such as pressures, temperatures and quantity measurements. A knowledge of the wet fraction when wet steam occurs may also be obtained. If the steam turbine drives a generator, the active generator power output of the turbo set is also available as a further measurement value. The efficiency of the steam turbine and the steam throughput coefficient can be calculated from these and from the mechanical data of the steam turbine and, if appropriate, of the turbo set which are known from design.
It became clear, then, that the illustration of the efficiency and of the steam throughput coefficient of the steam turbine as a function of the three parameters circumferential Mach number, pressure number and position of the inlet valves is particularly beneficial for the diagnostic method. The circumferential Mach number, as a measure of the rotational speed of the rotor blades, the pressure number, as a measure of the pressure of the fresh steam supplied to the turbine, and the position of the inlet valves, which regulate the inflow of fresh steam into the steam turbine, thus form a three-dimensional parameter space, in which the efficiency and also the steam throughput coefficient of the steam turbine in each case represent a scalar field. Each point of the three-dimensional parameter space is therefore assigned, for example, an efficiency value.
In this case, the circumferential Mach number M u may be described by
M u = u kp 1 v 1
and the pressure number F by
F = 2 k u 2 k - 1 p 1 v 1 [ 1 - ( p 2 p 1 ) k - 1 k ]
In this case, u is the circumferential speed, k(p,T) the isotropic exponent, p 1 the pressure and v 1 (p,T) the specific volume at the inlet and p 2 the pressure at the outlet of the steam turbine considered or of the turbine subregion considered. The circumferential speed u is given in steam turbines by
u =2 πr m n,
with r m as the mean radius of the annular area through which steam flows and with n as the rotational speed of the turbine rotor.
A change in the position of the inlet valves for the fresh steam upstream of a regulating stage on a steam turbine causes a geometric change in the steam flow at components through which steam flows. A change in the inlet valve position thus behaves in a similar way to a fault on components around which steam flows. It is therefore indispensable to include the inlet valve position in the illustration of the efficiency of a steam turbine.
For example, the change in the inlet valve position of a steam turbine may lead to a throttling of the steam flow. If, for example, salt deposits occur on the inlet valves in a steam turbine due to insufficient steam quality, this leads to increased flow resistance and therefore likewise to throttling. Without a knowledge of the changed inlet valve position, of the size of the geometric change in the steam inlet and of its effect on the thermodynamic behavior of the steam flow around the inlet valves, the cause of the thermodynamic change cannot be fully comprehended. Cause and effect cannot be associated unequivocally. With the measurement of the inlet valve position, however, a criterion is available for determining the geometric change in the steam flows and its effects on the thermodynamic behavior of the steam turbine. This may be used to determine the cause of the throttling.
A steam inlet valve usually includes a plurality of individual valves. The individual valves often open sequentially with overlap. The position of the inlet valve combination is often indicated in mm of stroke, taking into account the actuating travel for the travelling hydraulics. In order to be independent of the mechanical designs of the actuating hydraulics, it is advantageous to indicate the position of the inlet valves as a percentage.
The efficiency of a steam turbine can be calculated from the measured state variables. The same applies to the steam throughput coefficient. Both variables can, in turn, be illustrated as a function of an operating point which is derived from the value of the circumferential Mach number, of the pressure number and of the inlet valve position at the time point of measurement of the state variables. To diagnose aging phenomena on the steam turbine, at a first time point at which the steam turbine advantageously still has no aging phenomena, for example at the first commissioning of the steam turbine, the state variables are measured at a plurality of operating points of the steam turbine and the efficiency of the steam turbine is calculated from these.
The efficiency values are assigned the respective operating point. After a particular time, for example one year, the measurements are repeated. It is advantageous to select the operating points for the measurements at the second time point in such a way that they are approximately identical to the operating points of the measurements of the first time point. The more exactly the first and second operating points are in congruence, the more accurate the evidence can be as to the aging condition of the steam turbine.
One operating point (or two approximately identical operating points), then, can be assigned two efficiency values: one from the measurement of the first time point and one from the measurement of the second point. If the efficiency has deteriorated at an operating point in the time between the first time point and the second time point, this is attributable to thermodynamic changes within the steam turbine. Since there is a plurality of efficiency changes at various operating points, detailed evidence on the thermodynamic changes of the steam turbine can be obtained from these. The extent and nature of aging phenomena, for example erosions or deposits within the steam turbine, can be concluded from this detailed evidence. The same applies to the steam throughput coefficient, from the change in time of which conclusions as to aging can likewise be drawn.
The calculations are expediently based on the behavior of ideal steam. Although a steam turbine is operated with real steam, the thermodynamic behavior of the latter differs from that of ideal steam. However, basing the behavior on ideal steam considerably simplifies the calculations. Since steam turbines are operated with superheated steam, this approximation is permissible. For more accurate calculations which must be based on the thermodynamic behavior of real steam, the calculations on which the ideal steam laws are based can be refined by means of numerical methods.
In an advantageous embodiment of the invention, the efficiency and/or the steam throughput coefficient of the steam turbine are calculated at a plurality of first operating points of the steam turbine at a first time point and a first scalar field is calculated from these first measurement values by interpolation. Then, the efficiency and/or the steam throughput coefficient are/is calculated at a plurality of second operating points of the steam turbine at a second time point and a second scalar field is calculated from these measurement values by interpolation. The extent of aging of the steam turbine is concluded from the change in time of the first scalar field in relation to the second scalar field.
If measurements of the state variables are carried out at a first time point at a plurality of first operating points and the calculation of the efficiency and/or of the steam throughput coefficient is carried out from these, it is no longer necessary, in this embodiment of the invention, to place the operating points for the measurements at a second and later time point into the vicinity of the first operating points. The operating points at which the measurements and calculations are carried out at a second time point can thus be selected completely independently of the operating points of the first time point. This makes it possible that the steam turbine can be operated at the second time point in an operating mode which is completely independent of the operating mode at the time point of the first measurement. This is because, now, no longer are two values of, for example, the steam throughput coefficient at mutually corresponding first and second operating points compared, but, instead, two continuous scalar fields are compared.
The interpolation details may be gathered per se from the values of efficiency or steam throughput coefficient at the various operating points. If there are sufficient values at various operating points, the profile of the scalar field can be estimated and the intermediate regions between various operating points can be filled with further values by appropriate interpolation. If the characteristic of the scalar field for a type of steam turbine is known, measurements and subsequent calculations are necessary at only a few operating points, so that the highly accurate profile of the scalar field can be estimated. There are thus fixed values for the steam throughput coefficient and/or the efficiency of the steam turbine at every point of the three-dimensional parameter space. The values of efficiency or steam throughput coefficient from a first time point at any desired operating point can therefore be compared with the values of efficiency or steam throughput coefficient from a second time point. The extent of aging of the steam turbine can be concluded from these direct comparisons. It is likewise possible to consider the two scalar fields as continuums and to conclude the extent of the aging of the steam turbine from their change as a whole.
Advantageously, the efficiency and/or the steam throughput coefficient is calculated for a subregion of the steam turbine and the extent of aging of the subregion is concluded from this. The measurements of the state variables, such as the pressure, temperature and steam quantities of the steam turbine, can be measured at spatially different points of the steam turbine. It is thus possible to calculate the efficiency and/or the steam throughput coefficient for only a subregion, for example the turbine inflow region or the drum part.
The advantage of this method is that the spatial location of aging phenomena within the steam turbine is possible. So that changes in the steam turbine can be easily located within the framework of the thermodynamic diagnosis, it is advantageous as far as possible to subdivide the turbine into individual turbine sections through which steam flows. However, the assessment of the thermodynamic behavior of a turbine section is tied up with the knowledge of the boundary conditions, such as, for example, the steam pressure and steam temperature at the inlet and outlet of the turbine section. If appropriate, the drum part may be broken down into a plurality of drum subparts for measurement purposes.
In counterpressure turbines which are operated solely in the superheated steam state, the outflow region is assigned to the drum part. As regards the outflow region of condensation turbines, the difficulty arises that, by the measurement of pressure and temperature alone, the energy content of the wet steam is not described. It can be calculated, however, by an evaluation of the discharged heat quantity in the following condenser. If unregulated steam quantities are extracted from a steam turbine in the drum part at tapping points, these drum parts must be considered as drum parts connected in series. The outlet values for steam, temperature and steam pressure of the preceding drum part are the inlet values for the following drum part, taking into account the reduced steam quantity. The precondition is that the final steam quantity and its state values are detected by measurement. The turbine inflow region contains, as a rule, a fresh steam connection piece, steam sieve, quick-action shut-off valve, inflow box, inlet valve combination and regulating stage.
BRIEF DESCRIPTION OF THE DRAWINGS
An exemplary embodiment of the invention is explained with reference to four figures of which:
FIG. 1 shows a diagrammatic illustration of a steam turbine plant,
FIG. 2 shows a diagrammatic illustration of the operation of calculating the efficiency and steam throughput coefficient,
FIG. 3 shows a scalar field assigned to a first time point, and
FIG. 4 shows a scalar field assigned to a second time point.
DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS
FIG. 1 shows a diagrammatic illustration of a steam turbo set 1 which includes a steam turbine 2 and a following generator 3 . The steam turbo set 1 considered is installed in a heating power station which, for example, supplies a town with heating heat. In the heating power station, a plurality of boiler plants, not illustrated in FIG. 1 , feed a plurality of steam turbo sets via a busbar system, not illustrated in any more detail. The steam turbine 2 is designed as an axial counterpressure turbine. The fresh steam is led via pipelines 4 through quick-action shut-off valves, not illustrated in any more detail, to the steam turbine 2 . The turbine inflow region of the steam turbine 2 includes the inlet valves, referred to hereafter as the regulating valve combination 5 , and the following regulating stage 7 .
The regulating valve combination 5 includes four regulating valves. In the regulating stage 7 , the steam is expanded from 110 bar to about 60 bar (wheel space pressure). In the further run through the steam turbine 2 , the steam is further expanded in the drum part 9 and is fed on the exhaust-steam side into a steam system, not illustrated in any more detail, with an operating pressure of, for example, 13 bar.
The blading of the steam turbine 2 includes a single-stage blading in the regulating stage 7 of the constant-pressure form of construction and of four successive drum parts with different stage radii of the reaction form of construction in the drum part 9 . For the thermodynamic diagnosis, the steam turbine 2 is subdivided into the turbine inflow region with regulating valve combination 5 and regulating stage 7 and the drum part 9 .
The steam turbine 2 is operated with superheated steam, so that no wet-steam states occur. This is afforded by the abovementioned steam parameters. The design data of the turbine inflow region and the throughflow characteristics of the regulating valve combination 5 are available as backup from the design of the steam turbo set 1 . The steam throughput coefficient and the circumferential Mach number relate in each case to the inlet side of the two subregions, namely the turbine inflow region and the drum part of the steam turbine 2 .
State variables of the steam turbine 2 were measured at one hundred different time points within two years. The term “time point” is not interpreted hereafter as a discrete time value, but as a time interval, within which the state variables have been measured in a measurement period. What have been me the pressure p and the temperature T and also the quantity m of the fresh steam flowing through the pipelines 4 , the position S of the regulating valve combination 5 , the pressure p and the temperature T of the steam leaving the regulating stage 7 and the pressure p and temperature T of the steam emerging from the drum part 9 . Moreover, the power output P of the generator has been measured. The state variables of the steam turbine have been measured in each case at a plurality of operating points of the steam turbine within a measurement period. The efficiency W and the steam throughput coefficient F for each operating point of a measurement period have been calculated from the measurements. The calculation has been based on the following formulae:
Δ F = Δ F A - D f ( D , M u , S ) ∂ f ( D , M u , S ) ∂ D Δ D - M u f ( D , M u , S ) ∂ f ( D , M u , S ) ∂ M u Δ M u - S f ( D , M u , S ) ∂ f ( D , M u , S ) ∂ S Δ S
Δ W = Δ W A - D g ( D , M u , S ) ∂ g ( D , M u , S ) ∂ D Δ D - M u g ( D , M u , S ) ∂ g ( D , M u , S ) ∂ M u Δ M u - S g ( D , M u , S ) ∂ g ( D , M u , S ) ∂ S Δ S
with
F: steam throughput coefficient F A : W: efficiency W A : D: pressure number M u : circumferential Mach number S: inlet valve position
In each case a scalar field for the efficiency and the steam throughput coefficient of a measurement period have been determined by interpolation from a plurality of values for the efficiency and the steam throughput coefficient. Thus, after the conclusion of the one hundred measurement periods, in each case one hundred scalar fields for the efficiency and the steam throughput coefficient have been obtained.
FIG. 2 illustrates diagrammatically the calculation of the efficiency W and of the steam throughput coefficient F. The two parameters circumferential Mach number M u and pressure number D are calculated from the state variables pressure, temperature and steam quantity, which are measured on the steam turbine at the points shown in FIG. 1 . In this case, over the turbine section considered, in this case the turbine inflow region, u is the circumferential velocity, k the isentropic exponent calculable from the pressure and temperature, p 1 the pressure, v 1 the specific volume, calculable from the temperature and pressure, at the inlet of the turbine section, and p 2 of the pressure at the outlet of the turbine section. The circumferential velocity u is calculated by use of u=2πr m n, r m being the mean radius of the annular area through which steam flows and n being the rotational speed of the turbine rotor. The position S of the inlet valves (indicated as a percentage) is introduced as the third parameter. From the state variables and the parameter position S, circumferential Mach number M u and pressure number D, the efficiency W and the steam throughput coefficient F of the steam turbine T can be calculated when design-related data of the steam turbine T are additionally available.
FIG. 3 and FIG. 4 illustrate diagrammatically two scalar fields 31 , 41 for the efficiency W at two different time points t 1 and t 2 . T 1 is a time point at which the steam turbine was without aging phenomena and t 2 is about one year later. FIG. 3 shows a scalar field 31 in the form of a curved surface which is plotted against the parameters pressure number D and inlet valve position S. The parameter circumferential Mach number is left constant in this illustration and is not plotted as a parameter, so that the scalar field 31 can be illustrated in the form of a two-dimensional curved surface. It is, of course, also possible to illustrate the scalar field 31 against two other parameters of the three parameters circumferential Mach number M u , pressure number D and inlet valve position S, or against all three parameters.
In FIG. 4 , the efficiency W of the turbo inflow region is plotted in a similar way to FIG. 3 against the parameters inlet valve position S and pressure number D, as a scalar field 41 . The scalar field 41 from FIG. 4 is changed in form in relation to the scalar field 31 from FIG. 3 . Moreover, it is lower than the scalar field 31 : the efficiency W of the turbine inflow region is therefore lower at the second later time point t 2 than at the first time point t 1 . From the change in form of the scalar field 41 , as compared with the scalar field 31 , and from the reduction in efficiency W at various operating points, conclusions can be drawn as to the extent of aging of the turbine inflow region.
Measurements were carried out, as described with regard to FIG. 1 , at one hundred time points, that is to say within one hundred measurement periods, and were plotted, as in FIGS. 3 and 4 . By use of the multiplicity of measurements in one hundred different measurement periods, the time profile of the impairment in the efficiency W could be determined with high accuracy. Since similar measurements to those for the turbine inflow region were also carried out for the drum part 9 of the steam turbine 2 , the aging phenomena within the steam turbine 2 could also be locally delimited it was found that aging had occurred pre-eminently in the turbine inflow region, since the efficiency had fallen to the greatest extent there. Moreover, by virtue of the multiplicity of measurement periods, the timespan in which the greatest change in the efficiency W took place could be located with very high accuracy.
On enquiries made to the operator of the steam turbine 2 , it was found that, at that time point when the rapid impairment in the efficiency W was found afterwards, the heating power station had, to satisfy a high demand for heat. According to the operator's evidence, therefore, at that time point steam boilers were put into operation which had previously been shut down for a while.
Within the one hundred measurement periods, not only the efficiency W of the turbo inflow region and of the drum was, calculated, but also the steam throughput coefficient F. In the same way as the efficiency W, the steam throughput coefficient F was also calculated and plotted as a scalar field against the parameters circumferential Mach number M u , pressure number D and inlet valve position S. From the interaction between the changed efficiency W and the changed steam throughput coefficient F in the turbine inflow region, it could be diagnosed that, at the time point of the greatest changes, contamination was deposited to an increased extent on parts of the turbine inflow region around which steam flows. The operator could therefore be advised that, by new boilers being commissioned, contaminated steam had entered the steam turbine, with the result that contaminations had been deposited within the steam turbine 2 to an increased extent. From the extent of the reduction in the efficiency W and in the steam throughput coefficient F, the extent of the dirt deposits could be concluded and a deadline for the next inspection of the steam turbine 2 could be designated to the operator.
The invention being thus described, it will be obvious that the same may be varied in many ways. Such variations are not to be regarded as a departure from the spirit and scope of the invention, and 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.
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A diagnosis method is for detecting ageing symptoms in a steam turbine. The efficiency and the steam flow rate of an aged steam turbine is compared to the efficiency and the steam flow rate of a relatively new steam turbine. The efficiency and the steam flow rate are calculated using readings at several operating points on the steam turbine. The time history of the efficiency and steam flow rates applied in contrast to parameters such as the peripheral. Mach number, pressure figure and adjustment of the inlet valve provide information on the extent of ageing of the steam turbine.
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TECHNICAL FIELD OF INVENTION
[0001] The present invention relates to a hydraulically actuated camshaft phaser for varying the phase relationship between a crankshaft and a camshaft in an internal combustion engine; more particularly to such a camshaft phaser that is a vane-type camshaft phaser, and more particularly to a vane-type camshaft phaser which includes a first oil control valve located coaxially within the camshaft phaser to control engagement and disengagement of a lock pin and a second oil control valve that is coaxial with the first oil control valve for varying the phase relationship between the crankshaft and the camshaft.
BACKGROUND OF INVENTION
[0002] A typical vane-type camshaft phaser generally comprises a plurality of outwardly-extending vanes on a rotor interspersed with a plurality of inwardly-extending lobes on a stator, forming alternating advance and retard chambers between the vanes and lobes. Engine oil is selectively supplied to one of the advance and retard chambers and vacated from the other of the advance and retard chambers in order to rotate the rotor within the stator and thereby change the phase relationship between an engine camshaft and an engine crankshaft. Camshaft phasers also commonly include an intermediate lock pin which selectively prevents relative rotation between the rotor and the stator at an angular position that is intermediate of a full advance and a full retard position. The intermediate lock pin is engaged and disengaged by vented oil from the intermediate lock pin and supplying pressurized oil to the intermediate lock pin respectively.
[0003] Some camshaft phasers utilize one or more oil control valves located in the internal combustion engine to control the flow of pressurized oil to and from the advance chambers, retard chambers, and lock pin. One example of such a camshaft phaser is shown in U.S. patent application Publication No. 2010/0288215. In this arrangement, three separate supply signals need to be included in the camshaft bearing for communication to the camshaft phaser. More specifically, a first passage for the advance chambers, a second passage for the retard chambers, and a third passage for the lock pin is included in the camshaft bearing. Including three separate passages in the camshaft bearing undesirably increases the length of the camshaft bearing. Additionally, space may be limited in the internal combustion engine to package oil control valves therein which are needed to control oil to and from each of the three passages.
[0004] In order to eliminate the packaging concerns and increased camshaft bearing length issues associated with packaging the oil control valve in the internal combustion engine, some manufacturers have included the oil control valve coaxially within the camshaft phaser. While this arrangement is common for oil control valves that need to supply oil to the advance and retard chambers, the arrangement is less common for oil control valves that need to supply oil not only to the advance and retard chambers, but the intermediate lock pin as well. One example of such a camshaft phaser is shown in U.S. patent application Publication No. 2004/0055550. However, including a single oil control valve coaxially within the camshaft phaser to control oil to the lock pin in addition to the advance and retard chambers requires an increased camshaft phaser thickness in order to accommodate the passage supplying oil to and from the lock pin. A single oil control valve also prevents independent control of the lock pin function and the phasing function which may make engaging the intermediate lock pin with its lock pin seat difficult.
[0005] What is needed is an axially compact camshaft phaser with valving located coaxially within the camshaft phaser for controlling the phase relationship and for controlling the lock pin. What is also needed is such a camshaft phaser which allows for control of the phase relationship independent of the lock pin.
SUMMARY OF THE INVENTION
[0006] Briefly described, a camshaft phaser is provided for controllably varying the phase relationship between a crankshaft and a camshaft in an internal combustion engine. The camshaft phaser includes a stator having a plurality of lobes and connectable to the crankshaft of the internal combustion engine to provide a fixed ratio of rotation between the stator and the crankshaft. The camshaft phaser also includes a rotor coaxially disposed within the stator and having a plurality of vanes interspersed with the stator lobes defining alternating advance chambers and retard chambers. The advance chambers receive pressurized oil in order to change the phase relationship between the crankshaft and the camshaft in the advance direction while the retard chambers receive pressurized oil in order to change the phase relationship between the camshaft and the crankshaft in the retard direction. The rotor is attachable to the camshaft of the internal combustion engine to prevent relative rotation between the rotor and the camshaft. A lock pin is disposed within one of the rotor and the stator for selective engagement with a lock pin seat in the other of the rotor and the stator for substantially preventing relative rotation between the rotor and the stator when the lock pin is engaged with the lock pin seat. Pressurized oil is selectively supplied to the lock pin in order to disengage the lock pin from the lock pin seat while oil is selectively vented from the lock pin in order to engage the lock pin with the lock pin seat. A phase relationship control valve which is coaxial with the rotor is provided for controlling the flow of oil into and out of the advance and retard chambers. A lock pin control valve which is coaxial with the phase relationship control valve is provided for controlling the flow of oil to and from the lock pin. The phase relationship control valve is operational independent of the lock pin control valve.
[0007] Further features and advantages of the invention will appear more clearly on a reading of the following detail description of the preferred embodiment of the invention, which is given by way of non-limiting example only and with reference to the accompanying drawings.
BRIEF DESCRIPTION OF DRAWINGS
[0008] This invention will be further described with reference to the accompanying drawings in which:
[0009] FIG. 1 is an exploded isometric view of a camshaft phaser in accordance with the present invention;
[0010] FIG. 2A is an axial cross-section of the camshaft phaser in accordance with the present invention;
[0011] FIG. 2B is the axial cross-section of FIG. 2A showing a phase relationship control valve in a first position for supplying pressurized oil to retard chambers of the camshaft phaser and for venting oil from the advance chambers the camshaft phaser;
[0012] FIG. 2 B′ is an enlarged view of the pertinent elements of FIG. 2B without reference numbers to clearly shown the oil flow through the camshaft phaser;
[0013] FIG. 2C is the axial cross section of FIG. 2A showing the phase relationship control valve in a second position for supplying pressurized oil to the advance chambers and for venting oil from the retard chambers;
[0014] FIG. 2 C′ is an enlarged view of the pertinent elements of FIG. 2C without reference numbers to clearly shown the oil flow through the camshaft phaser;
[0015] FIG. 3A is an axial cross section of the camshaft phaser showing a lock pin control valve in a first position for supplying pressurized oil to lock pins of the camshaft phaser for retracting the lock pins from their lock pin seats;
[0016] FIG. 3 A′ is an enlarged view of the pertinent elements of FIG. 3A without reference numbers to clearly shown the oil flow through the camshaft phaser;
[0017] FIG. 3B is an axial cross section of the camshaft phaser showing the lock pin control valve in a second position for vented oil from the lock pins for seating the lock pins in their lock pin seats;
[0018] FIG. 3 B′ is an enlarged view of the pertinent elements of FIG. 3B without reference numbers to clearly shown the oil flow through the camshaft phaser;
[0019] FIG. 4 is a radial cross-section of the camshaft phaser taken in the direction of arrows 4 in FIG. 2A ;
[0020] FIGS. 5A-5D are enlarged isometric views of a manifold of the camshaft phaser where each Fig. is shown rotated 90° from the previous view;
[0021] FIG. 6A is an enlarged isometric view of a bushing adaptor of the camshaft phaser;
[0022] FIG. 6B is an isometric cross-section of the bushing adaptor of FIG. 6A ;
[0023] FIG. 7A is an axial cross section of a second embodiment of a camshaft phaser showing a lock pin control valve in a first position for supplying pressurized oil to lock pins of the camshaft phaser for retracting the lock pins from their lock pin seats;
[0024] FIG. 7 A′ is an enlarged view of the pertinent elements of FIG. 7A without reference numbers to clearly show the oil flow through the camshaft phaser;
[0025] FIG. 7B is an axial cross section of the second embodiment camshaft phaser showing the lock pin control valve in a second position for venting oil from the lock pins for seating the lock pins in their lock pin seats;
[0026] FIG. 7 B′ is an enlarged view of the pertinent elements of FIG. 7B without reference numbers to clearly show the oil flow through the camshaft phaser;
[0027] FIG. 8A is an enlarged isometric view of a manifold of the camshaft phaser of the second embodiment; and
[0028] FIG. 8B is an isometric cross-section of the manifold of FIG. 8A .
DETAILED DESCRIPTION OF INVENTION
[0029] In accordance with a preferred embodiment of this invention and referring to FIGS. 1 , 2 A, and 4 , internal combustion engine 10 is shown which includes camshaft phaser 12 . Internal combustion engine 10 also includes camshaft 14 which is rotatable based on rotational input from a crankshaft and chain (not shown) driven by a plurality of reciprocating pistons (also not shown). As camshaft 14 is rotated, it imparts valve lifting and closing motion to intake and/or exhaust valves (not shown) as is well known in the internal combustion engine art. Camshaft phaser 12 allows the timing between the crankshaft and camshaft 14 to be varied. In this way, opening and closing of the intake and/or exhaust valves can be advanced or retarded in order to achieve desired engine performance.
[0030] Camshaft phaser 12 includes sprocket 16 which is driven by a chain or gear (not shown) driven by the crankshaft of internal combustion engine 10 . Alternatively, sprocket 16 may be a pulley driven by a belt. Sprocket 16 includes a central bore 18 for receiving camshaft 14 coaxially therethrough which is allowed to rotate relative to sprocket 16 . Sprocket 16 is sealingly secured to stator 20 with sprocket bolts 22 in a way that will be described in more detail later.
[0031] Stator 20 is generally cylindrical and includes a plurality of radial chambers 24 defined by a plurality of lobes 26 extending radially inward. In the embodiment shown, there are four lobes 26 defining four radial chambers 24 , however, it is to be understood that a different number of lobes may be provided to define radial chambers equal in quantity to the number of lobes.
[0032] Rotor 28 includes central hub 30 with a plurality of vanes 32 extending radially outward therefrom and central through bore 34 which is stepped and extends axially therethrough. The number of vanes 32 is equal to the number of radial chambers 24 provided in stator 20 . Rotor 28 is coaxially disposed within stator 20 such that each vane 32 divides each radial chamber 24 into advance chambers 36 and retard chambers 38 . The radial tips of lobes 26 are mateable with central hub 30 in order to separate radial chambers 24 from each other. Preferably, each of the radial tips of vanes 32 includes one of a plurality of wiper seals 40 to substantially seal adjacent advance and retard chambers 36 , 38 from each other. Although not shown, each of the radial tips of lobes 26 may include a wiper seal similar in configuration to wiper seal 40 .
[0033] Central hub 30 includes a plurality of oil passages 42 A, 42 R formed radially therethrough (best visible as hidden lines in FIG. 4 ). Each one of the plurality of oil passages 42 A is in fluid communication with one of the advance chambers 36 for supplying oil thereto and therefrom while each one of the plurality of oil passages 42 R is in fluid communication with one of the retard chambers 38 for supplying oil thereto and therefrom.
[0034] Bias spring 44 is disposed within annular pocket 46 formed in rotor 28 and within central bore 48 of camshaft phaser cover 50 . Bias spring 44 is grounded at one end thereof to camshaft phaser cover 50 and is attached at the other end thereof to rotor 28 . When internal combustion engine 10 is shut down, bias spring 44 urges rotor 28 to a predetermined angular position within stator 20 in a way that will be described in more detail in the subsequent paragraph.
[0035] Now referring to FIGS. 1 , 3 A, and 3 B; camshaft phaser 12 includes a staged dual lock pin system for selectively preventing relative rotation between rotor 28 and stator 20 at the predetermined angular position which is between the extreme advance and extreme retard positions. Primary lock pin 52 is slidably disposed within primary lock pin bore 54 formed in one of the plurality of vanes 32 of rotor 28 . Primary lock pin seat 56 is formed in camshaft phaser cover 50 for selectively receiving primary lock pin 52 therewithin. Primary lock pin seat 56 is larger than primary lock pin 52 to allow rotor 28 to rotate relative to stator 20 about 5° on each side of the predetermined angular position when primary lock pin 52 is seated within primary lock pin seat 56 . The enlarged nature of primary lock pin seat 56 allows primary lock pin 52 to be easily received therewithin. When primary lock pin 52 is not desired to be seated within primary lock pin seat 56 as shown in FIG. 3A , pressurized oil is supplied to primary lock pin 52 , thereby urging primary lock pin 52 out of primary lock pin seat 56 and compressing primary lock pin spring 58 . Conversely, when primary lock pin 52 is desired to be seated within primary lock pin seat 56 as shown in FIG. 3B , the pressurized oil is vented from primary lock pin 52 , thereby allowing primary lock pin spring 58 to urge primary lock pin 52 toward camshaft phaser cover 50 . In this way, primary lock pin 52 is seated within primary lock pin seat 56 by primary lock pin spring 58 when rotor 28 is positioned within stator 20 to allow alignment of primary lock pin 52 with primary lock pin seat 56 .
[0036] Secondary lock pin 60 is slidably disposed within secondary lock pin bore 62 formed in one of the plurality of vanes 32 of rotor 28 . Secondary lock pin seat 64 is formed in camshaft phaser cover 50 for selectively receiving secondary lock pin 60 therewithin. Secondary lock pin 60 fits within secondary lock pin seat 64 in a close sliding relationship, thereby substantially preventing relative rotation between rotor 28 and stator 20 when secondary lock pin 60 is received within secondary lock pin seat 64 . When secondary lock pin 60 is not desired to be seated within secondary lock pin seat 64 as shown in FIG. 3A , pressurized oil is supplied to secondary lock pin 60 , thereby urging secondary lock pin 60 out of secondary lock pin seat 64 and compressing secondary lock pin spring 66 . Conversely, when secondary lock pin 60 is desired to be seated within secondary lock pin seat 64 as shown in FIG. 3B , the pressurized oil is vented from the secondary lock pin 60 , thereby allowing secondary lock pin spring 66 to urge secondary lock pin 60 toward camshaft phaser cover 50 . In this way, secondary lock pin 60 is seated within secondary lock pin seat 64 by secondary lock pin spring 66 when rotor 28 is positioned within stator 20 to allow alignment of secondary lock pin 60 with secondary lock pin seat 64 .
[0037] When it is desired to prevent relative rotation between rotor 28 and stator 20 at the predetermined angular position, the pressurized oil is vented from both primary lock pin 52 and secondary lock pin 60 , thereby allowing primary lock pin spring 58 and secondary lock pin spring 66 to urge primary and secondary lock pins 52 , 60 toward camshaft phaser cover 50 respectively. In order to align primary and secondary lock pins 52 , 60 with primary and secondary lock pin seats 56 , 64 respectively, rotor 28 may be rotated with respect to stator 20 by one or more of supplying pressurized oil to advance chambers 36 , supplying pressurized oil to retard chambers 38 , urging from bias spring 44 , and torque from camshaft 14 . Since primary lock pin seat 56 is enlarged, primary lock pin 52 will be seated within primary lock pin seat 56 before secondary lock pin 60 is seated within secondary lock pin seat 64 . With primary lock pin 52 seated within primary lock pin seat 56 , rotor 28 is allowed to rotate with respect to stator 20 by about 10°. Rotor 28 may be further rotated with respect to stator 20 by one or more of supplying pressurized oil to advance chambers 36 , supplying pressurized oil to retard chambers 38 , urging from bias spring 44 , and torque from camshaft 14 in order to align secondary lock pin 60 with secondary lock pin seat 64 , thereby allowing secondary lock pin 60 to be seated within secondary lock pin seat 64 . Supply and venting of oil to and from advance chambers 36 , retard chambers 38 , and primary and secondary lock pins 52 , 60 will be described in more detail later.
[0038] Now referring to FIGS. 1 and 2A , camshaft phaser cover 50 is sealingly attached to stator 20 by sprocket bolts 22 that extend through sprocket 16 and stator 20 and threadably engage camshaft phaser cover 50 . In this way, stator 20 is securely clamped between sprocket 16 and camshaft phaser cover 50 in order to axially and radially secure sprocket 16 , stator 20 , and camshaft cover 50 to each other.
[0039] Now referring to FIGS. 1 , 2 A, 2 B, 2 C, 6 A, and 6 B; bushing adaptor 68 is coaxially disposed within pocket 70 of camshaft 14 in a close fitting relationship. Bushing adaptor 68 is also coaxially disposed within central through bore 34 of rotor 28 in a press fit relationship to prevent relative rotation therebetween and may be press fit within central through bore 34 until bushing adaptor 68 abuts stop surface 72 formed by the stepped nature of central through bore 34 . When camshaft phaser 12 is attached to camshaft 14 , bushing adaptor 68 coaxially aligns camshaft phaser 12 with camshaft 14 . This allows the rotor 28 to be made more axially compact because axial space is not needed within rotor 28 for receiving camshaft 14 therewithin in order to coaxially align camshaft phaser 12 with camshaft 14 . A network of oil passages is defined in part by bushing adaptor 68 in a way that will be described in detail later.
[0040] Camshaft phaser 12 is attached to camshaft 14 with camshaft phaser attachment bolt 74 which extends axially through bushing adaptor 68 in a close fitting relationship. Rotor 28 is positioned against axial face 76 of camshaft 14 which is provided with threaded hole 78 extending axially into camshaft 14 from pocket 70 .
[0041] Annular oil chamber 80 is formed radially between camshaft phaser attachment bolt 74 and pocket 70 for receiving oil from camshaft oil passages 82 formed radially through camshaft 14 . Oil is supplied to camshaft oil passages 82 from internal combustion engine 10 through an oil gallery (not shown) in camshaft bearing 84 . When camshaft phaser attachment bolt 74 is tightened to a predetermined torque, head 86 of camshaft phaser attachment bolt 74 acts axially on bolt surface 88 of rotor 28 . In this way, camshaft phaser 12 is axially secured to camshaft 14 and relative rotation between rotor 28 and camshaft 14 is thereby prevented.
[0042] Bushing adaptor 68 defines at least in part supply passage 90 for communicating pressurized oil from internal combustion engine 10 to phase relationship control valve 92 . Supply passage 90 may be defined in part by first annular groove 94 formed on the inside diameter of bushing adaptor 68 . First annular groove 94 may be positioned axially within rotor 28 .
[0043] Supply passage 90 may be further defined by axial grooves 96 which extend axially part way into central through bore 34 of rotor 28 . Axial grooves 96 may be in fluid communication with first annular groove 94 through first connecting passages 98 which extend radially through bushing adaptor 68 .
[0044] Supply passage 90 may be further defined by second annular groove 100 formed on the inside diameter of bushing adaptor 68 and which may be positioned axially within pocket 70 of camshaft 14 . Second annular groove 100 may be in fluid communication with axial grooves 96 through second connecting passages 102 which extend radially through bushing adaptor 68 .
[0045] Supply passage 90 may be further defined by third annular groove 104 formed on the outside diameter of bushing adaptor 68 and axially between first annular groove 94 and second annular groove 100 . Third annular groove 104 may be in fluid communication with second annular groove 100 through second connecting passages 102 and may also be in fluid communication with axial grooves 96 by axially positioning third annular groove 104 on the outside diameter of bushing adaptor 68 such that axial grooves 96 at least partly overlap axially with third annular groove 104 .
[0046] Supply passage 90 may be further defined by blind bore 106 formed axially within camshaft phaser attachment bolt 74 . Blind bore 106 begins at the end of camshaft phaser attachment bolt 74 defined by head 86 and may extend to a point within camshaft phaser attachment bolt 74 that is axially aligned with annular oil chamber 80 . First radial drillings 108 extend radially through camshaft phaser attachment bolt 74 and provide fluid communication from annular oil chamber 80 to blind bore 106 while second radial drillings 110 are spaced axially apart from first radial drillings 108 and extend radially through camshaft phaser attachment bolt 74 to provide fluid communication from blind bore 106 to second annular groove 100 .
[0047] Now referring to FIGS. 1 , 2 A, 2 B, 2 C, and 5 A- 5 D; supply passage 90 may be further defined by manifold axial grooves 112 of manifold 114 which is press fit into blind bore 106 . Manifold axial grooves 112 are formed in the outer surface of manifold 114 and begin at an end of manifold 114 proximal to first radial drillings 108 and extend to overlap with second radial drillings 110 . Each manifold axial groove 112 is aligned with and overlaps one second radial drilling 110 . Other features and functions of manifold 114 will be described later in more detail.
[0048] Filter 116 may be captured in blind bore 106 between manifold 114 and shoulder 118 formed in blind bore 106 . Filter 116 substantially prevents foreign matter that may be present in the pressurized oil from being communicated to manifold axial grooves 112 and subsequently to other critical interfaces of camshaft phaser 12 .
[0049] Camshaft phaser attachment bolt 74 includes supply drillings 120 extending radially therethrough for providing fluid communication between first annular groove 94 and blind bore 106 . Supply drillings 120 allow pressurized oil to be supplied to phase relationship control valve 92 .
[0050] Now referring to FIGS. 1 , 2 A, 2 B, 6 A, and 6 B; in addition to defining at least in part supply passage 90 , bushing adaptor 68 , also defines at least in part advance passage 122 for selectively communicating pressurized oil from phase relationship control valve 92 to advance chambers 36 and for venting oil therefrom. Advance passage 122 may be defined at least in part by fourth annular groove 124 formed on the inside diameter of bushing adaptor 68 and axially between first annular groove 94 and second annular groove 100 . Through advance oil connecting passages 126 , fourth annular groove 124 is in fluid communication with oil passages 42 A that are in fluid communication advance chambers 36 . Advance oil connecting passages 126 extend radially from fourth annular groove 124 through bushing adaptor 68 .
[0051] Camshaft phaser attachment bolt 74 includes advance drillings 128 extending radially therethrough for providing fluid communication between fourth annular groove 124 and blind bore 106 . Advance drillings 128 allow pressurized oil to be selectively supplied from phase relationship control valve 92 to advance chambers 36 .
[0052] In addition to defining at least in part supply passage 90 and advance passage 122 , bushing adaptor 68 also defines at least in part retard passage 130 for selectively communicating pressurized oil from phase relationship control valve 92 to retard chambers 38 . Retard passage 130 may be defined by axial space 132 formed axially between axial end 134 and head 86 . Axial end 134 may be defined by reduced diameter section 136 which provides radial clearance between central through bore 34 of rotor 28 and reduced diameter section 136 . Axial space 132 is further defined radially between rotor 28 and camshaft phaser attachment bolt 74 . Axial space 132 is in fluid communication with oil passages 42 R that are in fluid communication with retard chambers 38 .
[0053] Camshaft phaser attachment bolt 74 includes retard drillings 138 extending radially through camshaft phaser attachment bolt 74 for providing fluid communication between axial space 132 and blind bore 106 . Retard drillings 138 allow pressurized oil to be selectively supplied from phase relationship control valve 92 to retard chambers 38 .
[0054] Phase relationship control valve 92 is disposed within camshaft phaser attachment bolt 74 and retained therein by retaining ring 140 which fits within groove 142 of camshaft phaser attachment bolt 74 . Phase relationship control valve 92 includes phase relationship valve spool 144 with phase relationship body 146 that is generally cylindrical, hollow and dimensioned to provide annular clearance between phase relationship body 146 and blind bore 106 of camshaft phaser attachment bolt 74 .
[0055] Phase relationship valve spool 144 also includes advance land 148 extending radially outward from phase relationship body 146 for selectively blocking fluid communication between supply drillings 120 and advance drillings 128 . Advance land 148 fits within blind bore 106 of camshaft phaser attachment bolt 74 in a close fitting relationship to substantially prevent oil from passing between advance land 148 and blind bore 106 .
[0056] Phase relationship valve spool 144 also includes retard land 150 extending radially outward from phase relationship body 146 for selectively blocking fluid communication between supply drillings 120 and retard drillings 138 . Retard land 150 is positioned axially away from advance land 148 and fits within blind bore 106 of camshaft phaser attachment bolt 74 in a close fitting relationship to substantially prevent oil from passing between retard land 150 and blind bore 106 .
[0057] Now referring to FIGS. 1 , 2 A, 2 B, and 2 C; phase relationship valve spool 144 is axially moveable within blind bore 106 with input from phase relationship control valve actuator 152 and phase relationship spool spring 154 . Phase relationship control valve actuator 152 is preferably an electrically actuated solenoid, but may be any type of actuator for axially moving phase relationship valve spool 144 . Phase relationship spool spring 154 is grounded to camshaft phaser attachment bolt 74 by seat 156 which is formed on the end of manifold 114 distal from first radial drillings 108 . A first end of phase relationship spool spring 154 is seated on seat 156 while a second end of phase relationship spool spring 154 is seated within phase relationship spool spring pocket 158 formed in an end of phase relationship valve spool 144 . In this way as shown in FIG. 2B , phase relationship spool spring 154 biases phase relationship valve spool 144 away from seat 156 when phase relationship control valve actuator 152 is not energized, thereby positioning phase relationship valve spool 144 within blind bore 106 such that pressurized oil is supplied to retard drillings 138 from supply drillings 120 while oil is vented from advance drillings 128 through central passage 160 of phase relationship valve spool 144 and through the end of blind bore 106 that is adjacent to head 86 . In contrast as shown in FIG. 2C , when phase relationship control valve actuator 152 is energized, the biasing force of phase relationship spool spring 154 is overcome to position phase relationship valve spool 144 within blind bore 106 such that pressurized oil is supplied to advance drillings 128 while oil is vented from retard drillings 138 to the end of blind bore 106 that is adjacent to head 86 .
[0058] Now referring to FIGS. 1 , 2 A, 2 B, 3 A, 3 B, and 5 A- 5 D; the function and additional features of manifold 114 will now be described. Manifold 114 is cylindrical and hollow and is included to provide passages for selectively supplying pressurized oil to primary and secondary lock pins 52 , 60 for removing primary and secondary lock pins 52 , 60 from primary and secondary lock pin seats 56 , 64 respectively. Manifold 114 is also included to provide passages for selectively venting oil from primary and secondary lock pins 52 , 60 for seating primary and secondary lock pins 52 , 60 from primary and secondary lock pin seats 56 , 64 respectively.
[0059] Manifold supply connecting passages 162 extend radially through manifold 114 in order to provide fluid communication from manifold axial grooves 112 to manifold central bore 164 which contains lock pin control valve 166 in a close fit sliding relationship.
[0060] Manifold 114 also includes blind axial grooves 168 for selectively supplying pressurized oil to primary and secondary lock pins 52 , 60 and for selectively venting oil from primary and secondary lock pins 52 , 60 . Blind axial groves 168 extend axially on the outer circumference of manifold 114 and are not open to either the end of manifold 114 proximal to first radial drillings 108 or the end of manifold 114 distal from first radial drillings 108 . Lock pin connecting passages 170 (shown as hidden lines in FIGS. 5A-5D ) extend radially through manifold 114 to provide fluid communication between manifold central bore 164 and blind axial grooves 168 .
[0061] Manifold 114 also includes vent grooves 172 for communicating oil from manifold central bore 164 that has been vented from primary and secondary lock pins 52 , 60 . Vent grooves 172 are located in the outer circumference of manifold 114 and extend axially into manifold 114 from the end of manifold 114 that is distal from first radial drillings 108 . Vent connecting passages 174 extend radially through manifold 114 to provide fluid communication between manifold central bore 164 and vent grooves 172 . Vent connecting passages 174 are spaced axially away from lock pin connecting passages 170 in the direction toward the end of manifold 114 that is distal from first radial drillings 108 . One of the vent grooves 172 extends axially further than the other vent grooves 172 and includes auxiliary vent connecting passage 176 to provide fluid communication between manifold central bore and vent groove 172 as shown best in FIGS. 5C and 5D . Auxiliary vent connecting passage 176 is spaced axially away from lock pin connecting passages 170 and manifold supply connecting passages 162 in the direction toward the end of manifold 114 that is proximal to first radial drillings 108 . The function of auxiliary vent connecting passage 176 will be discussed in more detail later.
[0062] Now referring to FIGS. 1 , 2 A, 2 B, 3 A, 3 B, 6 A, and 6 B; bushing adaptor 68 includes fifth annular groove 178 formed on the inside diameter thereof. Fifth annular groove 178 is axially aligned with lock pin drillings 180 that extend radially through camshaft phaser attachment bolt 74 as best shown in FIGS. 3A and 3B . Each lock pin drilling 180 is aligned with and is in fluid communication with one blind axial groove 168 . In this way, each blind axial groove 168 is in fluid communication with fifth annular groove 178 .
[0063] Primary lock pin drilling 182 and secondary lock pin drilling 184 extend from fifth annular groove 178 radially through bushing adaptor 68 . Primary lock pin drilling 182 is in fluid communication with primary lock pin passage 186 that extends through camshaft 14 and rotor 28 for supplying pressurized oil to primary lock pin 52 and for venting oil from primary lock pin 52 . Similarly, secondary lock pin drilling 184 is in fluid communication with secondary lock pin passage 188 that extends through camshaft 14 and rotor 28 for supplying pressurized oil to primary lock pin 52 and for venting oil from primary lock pin 52 .
[0064] Lock pin control valve 166 includes lock pin valve spool 190 with lock pin valve spool body 192 that is generally cylindrical and dimensioned to provide annular clearance between lock pin valve spool body 192 and manifold central bore 164 .
[0065] Lock pin control valve 166 also includes vent land 194 extending radially outward from lock pin valve spool body 192 for selectively blocking fluid communication between manifold central bore 164 and vent grooves 172 through vent connecting passages 174 as shown in FIG. 3A . Vent land 194 fits within manifold central bore 164 in a close fitting relationship to substantially prevent oil from passing between vent land 194 and manifold central bore 164 .
[0066] Lock pin control valve 166 also includes supply land 196 extending radially outward from lock pin valve spool body 192 for selectively blocking fluid communication between manifold central bore 164 and blind axial grooves 168 through manifold supply connecting passages 162 . Supply land 196 fits within manifold central bore 164 in a close fitting relationship to substantially prevent oil from passing between supply land 196 and manifold central bore 164 .
[0067] Lock pin control valve 166 is axially moveable within manifold central bore 164 with input from lock pin control valve actuator 198 and lock pin valve spool spring 200 . Lock pin control valve actuator 198 is preferably an electrically actuated solenoid, but may be any type of actuator for axially moving lock pin control valve 166 . Lock pin valve spool spring 200 is grounded to closed end 202 of manifold 114 which gives manifold 114 a cup-shaped cross-sectional shape. A first end of lock pin valve spool spring 200 is seated against closed end 202 while a second end of lock pin valve spool spring 200 is seated within spring recess 204 formed in the end of lock pin valve spool 190 proximal to closed end 202 as best shown in FIG. 3B . In this way, lock pin valve spool spring 200 biases lock pin valve spool 190 away from closed end 202 when lock pin control valve actuator 198 is not energized, thereby positioning lock pin valve spool 190 within manifold central bore 164 such that supply land 196 blocks pressurized oil from entering manifold central bore through manifold supply connecting passages 162 while oil is allowed to vent to vent grooves 172 from primary and secondary lock pins 52 , 60 through vent connecting passages 174 which are in fluid communication with manifold central bore 164 , lock pin connecting passages 170 , blind axial grooves 168 , lock pin drillings 180 , fifth annular groove 178 , and primary and secondary lock pin passages 186 , 188 . When lock pin control valve actuator 198 is not energized as shown in FIG. 3B , auxiliary vent connecting passage 176 is in fluid communication with manifold central bore 164 . In this way, the volume defined between closed end 202 and spring recess 204 is vented to prevent a sealed chamber from being formed that would require added force from lock pin control valve actuator 198 to compress a volume of air when actuated. In contrast, when lock pin control valve actuator 198 is energized as shown in FIG. 3A , the biasing force of lock pin valve spool spring 200 is overcome to position lock pin valve spool 190 within manifold central bore 164 such that pressurized oil is allowed to be communicated to primary and secondary lock pins 52 , 60 through manifold supply connecting passages 162 (not visible in FIG. 3A ), manifold central bore 164 , lock pin connecting passages 170 , blind axial grooves 168 , lock pin drillings 180 , fifth annular groove 178 , and primary and secondary lock pin drillings 182 , 184 while vent land 194 blocks vent connecting passages 174 . When lock pin control valve actuator 198 is energized, auxiliary vent connecting passage 176 is blocked by supply land 196 to prevent fluid communication between manifold central bore 164 and vent groove 172 through auxiliary vent connecting passage 176 .
[0068] In operation and referring to FIGS. 2A , 2 B, 3 A, 3 A′, 3 B, and 3 B′; when a change in phase relationship between camshaft 14 and the crankshaft of internal combustion engine 10 is desired, pressurized oil from internal combustion engine 10 is supplied to primary and secondary lock pins 52 , 60 where the path taken by the pressurized oil is represented by arrows P. This is accomplished by energizing lock pin control valve actuator 198 to prevent fluid communication from blind axial grooves 168 to vent connecting passages 174 , to block auxiliary vent connecting passage 176 , and to allow fluid communication from manifold axial grooves 112 to manifold supply connecting passages 162 . In this way, pressurized oil from internal combustion engine 10 is supplied to annular oil chamber 80 through camshaft oil passages 82 . From annular oil chamber 80 , the pressurized oil is supplied to blind bore 106 through first radial drillings 108 . The pressurized oil is then passed through filter 116 before reaching manifold axial grooves 112 . Oil flow through this area is shown as hidden lines in FIGS. 3 A and 3 A′ because manifold axial grooves 112 are not visible in FIGS. 3A , 3 A′, 3 B, and 3 B′. The pressurized oil then passes through manifold supply connecting passages 162 (also not visible in FIGS. 3A , 3 A′, 3 B, and 3 B′) to reach manifold central bore 164 . After reaching manifold central bore 164 , the pressurized oil passes through lock pin connecting passages 170 to reach blind axial grooves 168 . The pressurized oil then passes through lock pin drillings 180 which supply the pressurized oil to fifth annular groove 178 . Fifth annular groove 178 subsequently supplies pressurized oil to primary and secondary lock pin drillings 182 and 184 which cause primary and secondary lock pins 52 , 60 to retract from primary and secondary lock pin seats 56 , 64 respectively. For clarity, FIG. 3 A′ is provided without reference numbers and without elements that do not define the oil passages to clearly show the path taken by the pressurized oil as represented by arrows P.
[0069] Now referring to FIGS. 2A , 2 B, 2 B′, 2 C, and 2 C′; with primary and secondary lock pins 52 , 60 now retracted from primary and secondary lock pin seats 56 , 64 respectively, the phase relationship between camshaft 14 and the crankshaft of internal combustion engine 10 can now be altered. This is accomplished by supplying pressurized oil to either the advance chambers 36 or to the retard chambers 38 while oil is vented from the chambers that are not receiving pressurized oil. A portion of the pressurized oil that is supplied to manifold axial grooves 112 passes through second radial drillings 110 to supply the pressurized oil to second annular groove 100 . The pressurized oil is then communicated to third annular groove 104 through second connecting passages 102 which then communicate the pressurized oil to axial grooves 96 . The pressurize is then supplied to first annular groove 94 through first connecting passages 98 before being supplied to phase relationship control valve 92 through supply drillings 120 .
[0070] If the pressurized oil is desired to be supplied to retard chambers 38 , phase relationship control valve actuator 152 is placed in an unenergized state of operation. In this state of operation and as shown in FIG. 2C , phase relationship valve spool 144 is positioned within blind bore 106 to allow the pressurized oil to be communicated to retard drillings 138 from first connecting passages 98 where the path taken by the pressurized oil is represented by arrows P. Retard drillings 138 then communicate the pressurized oil to axial space 132 where the pressurized oil is then communicated to retard chambers 38 through oil passages 42 R.
[0071] At the same time, the pressurized oil is prevented from being communicated from first connecting passages 98 to advance drillings 128 by advance land 148 . Also at the same time, advance land 148 allows the oil to be vented from advance chambers 36 by placing advance drillings 128 in fluid communication with central passage 160 where the path taken by the vented oil is represented by arrows V. In this way, oil is allowed to be vented from advance chambers 36 through oil passages 42 A. The vented oil then passes from oil passages 42 A to fourth annular groove 124 through advance oil connecting passages 126 . The oil is then communicated to central passage 160 through advance drillings where the oil is then vented through the end of camshaft phaser attachment bolt 74 . Oil communicated through the end of camshaft phaser attachment bolt 74 is shown as hidden lines because the passages therethrough are not visible in this view. For clarity, FIG. 2 B′ is provided without reference numbers and without elements that do not define the oil passages to clearly show the path taken by the pressurized oil represented by arrows P and the path taken by the vented oil represented by arrows V.
[0072] However, if the pressurized oil is desired to be supplied to advance chambers 36 , phase relationship control valve actuator 152 is placed in an energized state of operation. In this state of operation as shown in FIG. 2C , phase relationship valve spool 144 is positioned within blind bore 106 to allow the pressurized oil to be communicated to advance drillings 128 from first connecting passages 98 where the path taken by the pressurized oil is represented by arrows P. Advance drillings 128 then communicate the pressurized oil to fourth annular groove 124 where the pressurized oil is then communicated to advance chambers 36 through advance oil connecting passages 126 and oil passages 42 A.
[0073] At the same time, the pressurized oil is prevented from being communicated from first connecting passages 98 to retard drillings 138 by retard land 150 . Also at the same time, retard land 150 allows the oil to be vented from retard chambers 38 by placing retard drillings 138 in fluid communication with central passage 160 where the path taken by the vented oil is represented by arrows V. In this way, oil is allowed to be vented from retard chambers 38 through oil passages 42 R. The vented oil then passes from oil passages 42 R to axial space 132 and then through retard drillings 138 and out the end of camshaft phaser attachment bolt 74 . For clarity, FIG. 2 C′ is provided without reference numbers and without elements that do not define the oil passages to clearly show the path taken by the pressurized oil represented by arrows P and the path taken by the vented oil represented by arrows V.
[0074] In operation and referring to FIGS. 2A and 3B , when it is desired to lock rotor 28 at the predetermined angular position with respect to stator 20 , oil is vented from primary and secondary lock pins 52 , 60 in order to seat primary and secondary lock pins 52 , 60 within primary and secondary lock pin seats 56 , 64 respectively. This is accomplished by placing lock pin control valve actuator in an unenergized state of operation. In the unenergized state of operation, lock pin valve spool 190 is positioned within manifold central bore 164 to prevent fluid communication between manifold supply connecting passages 162 and lock pin connecting passages 170 with supply land 196 . In this way, pressurized oil is prevented from being supplied to primary and secondary lock pins 52 , 60 .
[0075] At the same time, vent land 194 no longer blocks vent connecting passages 174 and auxiliary vent connecting passage 176 , and as a result, lock pin connecting passage 170 is now in fluid communication with vent connecting passage 174 . In this way, the oil is vented from primary and secondary lock pins 52 , 60 through primary and secondary lock pin passages 186 , 188 where the path taken by the vented oil is represented by arrows V. The oil from primary and secondary lock pin passages 186 , 188 is then passed to fifth annular groove 178 through primary and secondary lock pin drillings 182 , 184 respectively before being communicated to blind axial grooves 168 through lock pin drillings 180 . The oil is then communicated from blind axial grooves 168 to manifold central bore 164 through lock pin connecting passages 170 before being communicated to vent grooves 172 through vent connecting passages 174 . The oil is then vented through the end of camshaft phaser attachment bolt 74 by passing through central passage 160 . Oil communicated through the end of camshaft phaser attachment bolt 74 is shown as hidden lines because the passages therethrough are not visible in this view. For clarity, FIG. 3 B′ is provided without reference numbers and without elements that do not define the oil passages to clearly show the path taken by the vented oil represented by arrows V.
[0076] With the oil vented from primary and secondary lock pins 52 , 60 , primary and secondary lock pin springs 58 , 66 urge primary and secondary lock pins 52 , 60 respectively toward camshaft phaser cover 50 . However, unless primary and secondary lock pins 52 , 60 are already aligned with primary and secondary lock pin seats 56 , 64 respectively, one or both of the primary and secondary lock pins 52 , 60 will not be seated within primary and secondary lock pin seats 56 , 64 respectively. In order to seat primary and secondary lock pins 52 , 60 within primary and secondary lock pin seats 56 , 64 respectively, the phase relationship between rotor 28 and stator 20 will need to be altered. This may be accomplished by supplying the pressurized oil to either advance chambers 36 or retard chambers 38 as needed to achieve the predetermined angular relationship of rotor 28 within stator 20 . This may also be accomplished by allowing bias spring 44 to urge rotor 28 to the predetermined angular position. Furthermore, this may be accomplished by allowing torque from camshaft 14 to urge rotor 28 to the predetermined angular position. As described earlier, primary lock pin 52 will be seated within primary lock pin seat 56 first thereby holding rotor 28 near the predetermined angular position. Secondary lock pin 60 will then be seated within secondary lock pin seat 64 when secondary lock pin 60 is aligned with secondary lock pin seat 64 .
[0077] Now referring to FIGS. 7A , 7 B, 8 A, and 8 B; a second embodiment camshaft phaser 12 ′ in accordance with the present invention is shown. Reference numbers of elements used in the description of camshaft phaser 12 will also be used in the description of element of camshaft phaser 12 ′ that are identical to the elements of camshaft phaser 12 . The differences of camshaft phaser 12 ′ relative to camshaft phaser 12 will now be described. Rather than using a spool-type valve to control oil being supplied to and from primary and secondary lock pins 52 , 60 as camshaft phaser 12 uses, camshaft phaser 12 ′ uses a poppet-type valve to control oil being supplied to and from primary and secondary lock pins 52 , 60 . In order to implement a poppet-type valve to control oil being supplied to and from primary and secondary lock pins 52 , 60 , manifold 114 ′ is provided which is press fit within blind bore 106 . Manifold 114 ′ includes manifold axial grooves 112 which are formed in the outer surface of manifold 114 ′ and begin an end of manifold 114 ′ proximal to first radial drillings 108 and extend to overlap with second radial drillings 110 (not visible in FIGS. 7A , 7 B, 8 A, and 8 B) of camshaft phaser attachment bolt 74 . Each manifold axial groove 112 is aligned with and overlaps one second radial drilling 110 to supply pressurized oil to phase relationship control valve 92 in the same way manifold axial grooves 112 of manifold 114 supply pressurized oil to phase relationship control valve 92 the embodiment of camshaft phaser 12 .
[0078] Manifold 114 ′ includes manifold central bore 164 ′ that extends axially through manifold 114 ′. Manifold central bore 164 ′ includes inner annular rib 206 which defines a portion of manifold central bore 164 ′ that is smaller in diameter than the remainder of manifold central bore 164 ′. Inner annular rib 206 is offset axially from each end of manifold central bore 164 ′ and defines supply seat 208 on the side of manifold 114 ′ proximal to first radial drillings 108 . Inner annular rib 206 also defines vent seat 210 on the side of manifold 114 ′ distal to first radial drillings 108 .
[0079] Lock pin connecting passages 170 ′ extend radially through inner annular rib 206 to provide fluid communication between manifold central bore 164 ′ and blind axial grooves 168 . Each blind axial groove 168 is aligned with and is in fluid communication with one lock pin drilling 180 in the same way as in camshaft phaser 12 .
[0080] Manifold 114 ′ together with ball 212 and plunger 214 define lock pin control valve 166 ′. Ball 212 is disposed within the side of manifold central bore 164 ′ that is adjacent to supply seat 208 . Ball 212 is selectively seated against supply seat 208 by pressurized oil and is selectively unseated from supply seat 208 by plunger 214 .
[0081] Plunger 214 includes plunger shaft 216 that extends through central passage 160 of phase relationship valve spool 144 and is sized to provide radial clearance therebetween. Plunger shaft 216 also extends coaxially through phase relationship control valve actuator 152 . Plunger 214 extends part way through inner annular rib 206 and is sized provide radial clearance therebetween.
[0082] Plunger 214 also includes outer annular rib 218 which extends radially outward therefrom. Outer annular rib 218 is sized to provide radial clearance between manifold central bore 164 ′ and to seat against vent seat 210 .
[0083] Plunger 214 also includes spring stop 220 which extends radially outward from plunger shaft 216 . A first end of lock pin valve spring 222 is seated against spring stop 220 while a second end of lock pin valve spring is grounded to plunger guide 224 which is disposed in blind bore 106 adjacent to manifold 114 ′. Lock pin valve spring 222 biases plunger 214 to unseat outer annular rib 218 from vent seat 210 when lock pin control valve actuator 198 is unenergized. Plunger guide 224 includes axial through holes 226 to provide fluid communication through plunger guide 224 as will be discussed later in more detail.
[0084] In operation as shown in FIG. 7A , when a change in phase relationship between camshaft 14 and the crankshaft of internal combustion engine 10 is desired, pressurized oil from internal combustion engine 10 is supplied to primary and secondary lock pins 52 , 60 . This is accomplished by energizing lock pin control valve actuator 198 to seat outer annular rib 218 against vent seat 210 and to unseat ball 212 from supply seat 208 . In this way, pressurized oil from internal combustion engine 10 is supplied to annular oil chamber 80 through camshaft oil passages 82 where the path taken by the pressurized oil is represented by arrows. From annular oil chamber 80 , the pressurized oil is supplied to blind bore 106 through first radial drillings 108 . The pressurized oil is then passed through filter 116 and supplied to manifold central bore 164 ′. Because outer annular rib 218 is seated against vent seat 210 , the pressurized oil is forced to exit manifold central bore 164 ′ through lock pin connecting passages 170 ′ to blind axial grooves 168 . The pressurized oil then passes through lock pin drillings 180 which supply the pressurized oil to fifth annular groove 178 . Fifth annular groove 178 subsequently supplies the pressurized oil to primary and secondary lock pin drillings 182 and 184 which cause primary and secondary lock pins 52 , 60 to retract from primary and secondary lock pin seats 56 , 64 respectively. For clarity, FIG. 7 A′ is provided without reference numbers and without elements that do not define the oil passages to clearly shown the path taken by the pressurized oil as represented by arrows P.
[0085] With primary and secondary lock pins 52 , 60 now retracted from primary and secondary lock pin seats 56 , 64 respectively, the phase relationship phase relationship between camshaft 14 and the crankshaft of internal combustion engine 10 can now be altered. This is accomplished in the same way as in camshaft phaser 12 and will not be further described.
[0086] In operation as shown in FIG. 7B , when it is desired to lock rotor 28 at the predetermined angular position with respect to stator 20 , oil is vented from primary and secondary lock pins 52 , 60 in order to seat primary and secondary lock pins 52 , 60 within primary and secondary lock pin seats 56 , 64 respectively. This is accomplished by placing lock pin control valve actuator 198 in an unenergized state of operation. In the unenergized state of operation, lock pin valve spring 222 urges plunger 214 away from ball 212 such that plunger 214 no longer prevents ball 212 from seating against supply seat 208 . As a result, pressurized oil from internal combustion engine 10 now seats ball 212 against supply seat 208 . In this way, pressurized oil is prevented from being supplied to primary and secondary lock pins 52 , 60 .
[0087] At the same time, outer annular rib 218 is unseated from vent seat 210 which places lock pin connecting passage 170 ′ in fluid communication with central passage 160 of phase relationship valve spool 144 . In this way, the oil is vented from primary and secondary lock pins 52 , 60 through primary and secondary lock pin passages 186 , 188 where the path taken by the vented oil is represented by arrows. The oil from primary and secondary lock pin passages 186 , 188 is then passed to fifth annular groove 178 through primary and secondary lock pin drillings 182 , 184 respectively before being communicated to blind axial grooves 168 through lock pin drillings 180 . The oil is then communicated from blind axial grooves 168 to manifold central bore 164 ′ through lock pin connecting passages 170 ′ before being communicated through axial through holes 226 of plunger guide 224 . The oil is then vented through the end of camshaft phaser attachment bolt 74 by passing through central passage 160 . Oil communicated through the end of camshaft phaser attachment bolt 74 is shown as hidden lines because the passages therethrough are not visible in this view. For clarity, FIG. 7 B′ is provided without reference numbers and without elements that do not define the oil passages to clearly show the path taken by the vented oil represented by arrows V.
[0088] While internal combustion engine 10 has been described as having camshaft phaser 12 applied camshaft 14 , it should now be understood internal combustion engine 10 may include multiple camshafts and that each camshaft may include its own camshaft phaser. It should also be understood that one camshaft may use a camshaft phaser in accordance with the present invention, while the second camshaft phaser may be another type of camshaft phaser, for example, an electrically actuated camshaft phaser. It should also be understood that the present invention applies to both internal combustion engines with a single bank of cylinders and to internal combustion engines with multiple banks of cylinders.
[0089] The operation of camshaft phaser 12 has been described as supplying pressurized oil to retard chambers 38 when phase relationship control valve actuator 152 is not energized, while at the same time venting oil from advance chambers 36 . It should now be understood that operation of camshaft phaser 12 could also be arranged to supply pressurized oil to advance chambers 36 when phase relationship control valve actuator 152 is not energized, while at the same time venting oil from retard chambers 38 . Similarly, the operation of camshaft phaser 12 has been described as supplying pressurized oil to advance chambers 36 when phase relationship control valve actuator 152 is energized, while at the same time venting oil from retard chambers 38 . It should now be understood that the operation of camshaft phaser 12 could also be arranged to supply pressurized oil to retard chambers 38 when phase relationship control valve actuator 152 is energized, while at the same time venting oil from advance chambers 36 .
[0090] While this invention has been described in terms of preferred embodiments thereof, it is not intended to be so limited, but rather only to the extent set forth in the claims that follow.
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A camshaft phaser is provided for varying the phase relationship between a crankshaft and a camshaft in an engine. The camshaft phaser includes a stator having lobes. A rotor is disposed within the stator includes vanes interspersed with the stator lobes to define alternating advance and retard chambers. A lock pin is provided for selective engagement with a lock pin seat for preventing relative rotation between the rotor and the stator. Pressurized oil disengages the lock pin from the seat while oil is vented for engaging the lock pin with the seat. A phase relationship control valve is coaxial with the rotor and controls the flow of oil into and out of the chambers. A lock pin control valve is coaxial with the phase relationship control valve and controls the flow of oil to and from the lock pin. The control valves are operational independent of each other.
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CROSS-REFERENCE TO RELATED APPLICATION
[0001] This application claims priority of U.S. provisional patent applications Ser. No. 60/679,525, filed May 10, 2005, and 60/756,259, filed Jan. 4, 2006.
FEDERALLY SPONSORED RESEARCH OR DEVELOPMENT
[0002] Not Applicable.
TECHNICAL FIELD
[0003] This invention generally relates to a voice activated distance measuring device, such as for providing distance and other information to a golfer.
BACKGROUND OF THE INVENTION
[0004] Range finding devices, such as the SkyCaddie range finder sold by Skyhawke Technologies, LLC (see www.skygolfgps.com), are known and provide information to golfers, such as the distance to a golf pin. However such devices require manual requests for information and provide only visual display of the requested information, which can be cumbersome to the golfers.
[0005] The present invention is provided to address this and other issues.
BRIEF DESCRIPTION OF THE DRAWINGS
[0006] FIG. 1 is a plan view of a printed circuit board in accordance with the invention;
[0007] FIG. 2 is a perspective view of the printed circuit board assembly of FIG. 1 , mounted in the brim of a hat; and
[0008] FIG. 3 is a view of the printed circuit board and brim of FIG. 2 , illustrating a recess in the brim to receive the printed circuit board assembly.
DETAILED DESCRIPTION OF THE INVENTION
[0009] While this invention is susceptible of embodiment in many different forms, there will be described herein in detail, specific embodiments thereof with the understanding that the present disclosure is to be considered as an exemplification of the principles of the invention and is not intended to limit the invention to the specific embodiments illustrated.
[0010] The present invention is a device that measure distances on a golf course and provides other relevant information. The device is useful for other applications, as well. The device uses voice recognition technology and GPS technology to provide a user, such as a golfer, with required data on the golf course and its parameters in a verbal electronically spoken form. The electronics and software for this device may be incorporated into an article of clothing, or other portable device, such as an article of headgear, including a golf hat or visor. The device may alternatively use distance measuring technology such as infra red, optics, Doppler acoustics and the like.
[0011] The device uses commercially available GPS data, such as supplied by Sports Mapping, Inc., or similar company, providing golf course mapping data to convert GPS mapped longitude and latitude coordinates to measure distance and other factors.
[0012] The device may use any GPS system available to measure the longitude and latitude coordinates to compute the distance and other golf course parameters.
[0013] The device incorporates voice recognition technology to accept voice commands from the user which are sensed by a voice sensor, such as a bone conductance vibration sensor or a microphone, which drives the voice recognition software. The device responds to voice commands such as “distance,” “pin-placement,” or any other such word or words.
[0014] Commands may also be in the form of an electrical signal from a switch or any electrical pulse generated by touch or remote control.
[0015] The device incorporates voice synthesis technology to provide an audible output by electronically produced spoken words, to provide distance and other information to the user via a loudspeaker or headphone, following a verbal command from the user. The output acoustics can be adjusted for volume level and frequency filtered for any particular user requirement or application. The device may also provide in a verbal form other information such as the green size, pin placement and other information on the golf course parameters.
[0016] The GPS and voice recognition electronics, for the GPS distance measurement and the voice recognition circuits and software, including the voice sensor, speaker and power source, may be incorporated into any design of headgear, such as a hat or visor, such as golf headgear, or any other article of clothing for golf or other sport.
[0017] As an additional feature the device may also accept verbal or any other data input and memorize and compute this, when prompted by voice command or an electrical pulse generated by touch or remote control, to predict golf course user golf strategy, club selection, rules and other golf player needs. For example the user may verbally enter information, either directly or by a verbal prompt, such as the club selected for the shot. The GPS technology determines the actual distance traveled by the ball and its accuracy. Information regarding weather conditions, such as wind speed and wind direction, may also be provided. Over time the device may build a library of information regarding the golfer's personal shot results, such as how far does a ball typically travel, and how accurately, when hit with each club. The device may collate and memorize this information and function as an expert system to progressively learn the golfer's successes and failures to generate a strategic recommendation which may also be based on an algorithm which is developed for this system. In summary this information can be used to provide the golfer with recommendations for future golf shots based on the golfer's past performance.
[0018] The bone conductance vibration sensor receives audio from the user directly from vibrations conducted through the skull of the user by direct mechanical contact of the sensor to the user's forehead. Such technology is superior to conventional microphones in that the user's voice is picked up clearly while substantially all external noise, such as but not limited to side chatter or wind noise, is rejected. There will be an increase in voice recognition accuracy achieved by the use of the bone conductance vibration sensor.
[0019] The unique design of this device, in one possible form as a hat or similar headgear, facilitates direct contact of the bone conductance vibration sensor with the user's forehead, providing the headgear design a unique advantage.
[0020] This device may also be used to provide pre recorded golf instructions to assist the golfer in making a specified golf shot, when prompted to do so by a voice recognition command.
[0021] The device may be used for such applications as hiking, surveyors and hunters and other applications. The device may also be used for scuba divers using an underwater design which may use any latitude and longitude measurement technology.
[0022] The device may be expanded to include its use in any portable application.
[0023] The device may be provided with a communications method, such as but not limited to a serial, USB or wireless connection to a separate personal computer or similar technology provided by the user of this device. The device may be able to upload and download data to the separate computer to facilitate various detailed functions, if such functions are beyond the scope of the device by itself such as, but not limited to, graphical display of the users score and plot of all ball trajectories viewed against an image of the subject golf course, display of clubs used, comparative display of any other player or players using the system, expert system advice based on data accrued during one or more recorded games, printing of results and scorecards. The connection may also facilitate uploading of new course databases to the device and management thereof, training of voice recognition commands and management of those commands.
[0024] A main printed circuit board (PCB) assembly 10 to reside in a brim 12 of a hat 14 is illustrated in FIGS. 1, 2 and 3 . The circuitry for the device is substantially mounted on the PCB assembly 10 . The PCB assembly 10 is seated in and supported by, a molded space 18 in a plastic brim stiffener 20 . The PCB assembly 10 is composed of three rigid printed circuit boards 10 a , 10 b , 10 c , connected by flexible flat cable 22 , so as to permit the PCB assembly 10 to follow the curvature of the brim 12 .
[0025] The center PCB 10 b of the PCB assembly 10 has a connector extension 24 , 1 cm long, designed to extend through hat fabric and be accessible from the inside hat.
[0026] Referring to FIG. 3 , a rectangular battery 26 is sewn into a compartment on a side of the hat 14 , positioned and padded for comfortable wear. Battery wiring 26 ′ runs through the hat and connects to the PCB assembly 10 using a channel detent 28 in the stiffener 20 (See FIG. 3 ). An internal headband area holds a transducer 30 , such as a bone conductance vibration sensor, supported by acoustic dampening material. The bone conductance vibration sensor will contact a wearer's forehead, with support elastic sewn in to assure the device maintains @20 g contact pressure, while maintaining comfort. Alternatively a conventional acoustical microphone could be utilized.
[0027] Referring to FIG. 3 , the plastic brim insert stiffener 20 has the molded space 18 for the PCB assembly 10 . Two channels are cut out at the rear to allow for PCB connector and wiring channel. The brim 12 further includes a circular opening 38 for a down facing speaker.
[0028] The top of the PCB assembly 10 is protected by layer of electrostatic protective padding material, and is finished in a fabric of similar weave and color to hat body.
[0029] Bluetooth, a known and published radio frequency short range data/audio transfer technology, may be used in the device for five primary purposes, data transfers, as an audio server, as an audio client, short range audio communications and as a remote GPS.
[0030] Externally sourced data transfers to the device's internal nonvolatile storage memory may be via a wired connection to the device's internal nonvolatile storage memory. Wireless installation of golf course data or program updates via Bluetooth or similar technology will allow such conveniences as allowing a golfer to upload golf course GPS coordinate data while in the pro shop or retail outlet without needing a wired connection or even removing the hat device from his/her head. This will facilitate and encourage users to purchase golf course files.
[0031] The device may include Bluetooth technology, a conventional communication/data/audio transfer technology, for five primary purposes, data transfers, as an audio server, as an audio client, short range audio communications and as a remote GPS.
[0032] As a Bluetooth audio server, it will be possible for the user to use a separate Bluetooth headset of the type used often in cell phones to access the voice recognition input and audio output of the device, without using the hat device's own built in speaker/voice sensor. This would enable the user to use the device even if the hat were not worn, or indeed if the device were not in a hat at all, and was implemented as any other form of wearable computer not requiring a built in speaker/voice sensor.
[0033] As a Bluetooth audio client, the hat device's speaker/voice sensor could be used for an auxiliary headset for another Bluetooth audio server such as a cell phone, in the same manner a Bluetooth ear clip headset is currently used.
[0034] As a short range audio communications client, it would be possible for two users of the device to maintain wireless audio communications providing they were in range typical of Bluetooth devices, usually 100 m maximum.
[0035] As a remote GPS, it would be possible for a user to use the GPS contained in the hat device with another program which required a GPS by transmitting the coordinate data over the Bluetooth using known Bluetooth protocols for GPS data transmission.
[0036] The device further permits a user to record geographic coordinates of a golf course, including its hazards and fairway boundaries, by use of a portable computing device equipped with a global positioning (GPS) device. Such recording can be done by, but not limited to, voice commands, keyboard, mouse or touch screen input. The device is running a program in the form of compiled computer code that continually receives updated latitude and longitude coordinates from the GPS, and on receiving input from the user, records those coordinates in permanent storage, such as but not limited to non-volatile memory or magnetic recording of a file on disk.
[0037] The user in the process of recording the course travels physically to course locations such as but not limited to tee off points, fairway boundaries, sand trap boundaries, water boundaries and green boundaries. Upon physically reaching the exact geographic point desired, the user indicates the hole number of the course and the type of course location using an input method previously described. The geographic coordinates (latitude, longitude, altitude) are then appended to non-volatile storage as previously described.
[0038] The golf course recording process will be designed in such a way as to allow the average person who is not necessarily an expert in computer or GPS technologies an easy method to record any golf course that s/he may wish to record, and allow for that course recording to be electronically transmitted to others for the purposes of sharing recorded courses and building up a shared collection of recorded courses. Upon completion of the recording of course features, the complete file containing multiple instance recordings of course name, hole number, hole feature and geographic location can be used to facilitate the calculation of geographic distances between the golfers current GPS position and those features, such as but not limited to the distance from the golfer to the center of the green. Other course feature recordings may be used also in the process of giving the golfer advice, by relating his/her current geographic position to those features. The recorded course data may also be used for other purposes, such as but not limited to information for greens keepers to assist in course maintenance or the production of maps or computer models.
[0039] From the foregoing, it will be observed that numerous variations and modifications may be effected without departing from the spirit and scope of the invention. It is to be understood that no limitation with respect to the specific apparatus illustrated herein is intended or should be inferred. It is, of course, intended to cover by the appended claims all such modifications as fall within the scope of the claims.
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A voice activated device for annunciating a message indicative of a distance of the device spaced from another location is disclosed. The device comprises a voice sensor for receiving a voice command requesting annunciation of a message indicative of the distance of the device spaced from the other location, converting circuitry coupled to the voice sensor for converting the received voice command to a corresponding electrical command, determining circuitry responsive to the electrical command for determining the distance of the device from the other location, and a speaker coupled to the determining circuitry for annunciating the message indicative of the determined distance of the device from the other location. The device may be used for informing a golfer of the golfer's distance from the pin.
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This application is a continuation of application Ser. No. 681,531 filed Dec. 14, 1984, now abandoned.
BACKGROUND OF THE INVENTION
The field of this invention is turbochargers of the type used to provide pressurized combustion air to an internal combustion engine. More particularly, this invention relates to a turbocharger including a housing journaling an elongate shaft for rotation with a turbine and a compressor. The turbine and compressor are spaced apart at opposite ends of the shaft, and the housing defines a closed void substantially surrounding the shaft. A quantity of material having selected heat transfer and heat absorptive qualities is disposed within the closed void for controlling the temperature of both the shaft and housing bearings following engine shutdown.
Turbochargers in general are well known in the pertinent art for supplying pressurized combustion air to an internal combustion Otto or Diesel cycle engine. Historically turbochargers have been used on large engines for stationary or heavy automotive farm or construction vehicle applications. These turbocharges generally include a housing including a turbine housing section for directing exhaust gases from an exhaust inlet to an exhaust outlet across a rotatable turbine. The turbine drives a shaft journaled in the housing. A compressor is driven by the shaft and spaced from the turbine housing section. A compressor housing section receives the compressor and defines an air inlet for inducting ambient air and an air outlet for delivering the air pressurized to an inlet manifold of the engine.
Because these past turbocharger applications involved relatively low specific engine power outputs with relatively low exhaust gas temperatures and infrequent engine shutdowns no special precautions were necessary to cool the shaft and the bearings journaling the shaft. Experience showed that the usual engine pressure oil flow lubrication which was necessary during turobcharger operation also by its cooling effect maintained the shaft and bearings at a temperature low enough to prevent oil coking in the turbocharger after engine shutdown. Because the operating temperature of the hot turbine end of the turbocharger was low enough and the mass of the turbocharger relatively large, the highest temperature experienced at the shaft and bearings after the oil flow was stopped was not high enough to degrade or coke the oil remaining in the turbocharger after engine shutdown.
However, passenger car automotive turbocharger applications have brought to light many problems. The specific engine outputs are usually higher leading to higher exhaust gas temperatures. The turbocharger itself is considerably smaller than its heavy equipment predecessor so that a smaller thermal mass is available to dissipate residual heat from the turbine housing section and turbine after engine shutdown. The result has been that heat soaking from the turbine housing section and turbine into the shaft and remainder of the housing raise the temperature high enough to degrade or coke the remaining oil in the housing after engine shutdown. Of course, this coked oil may plug the bearings so that subsequent oil flow lubrication and cooling is inhibited. This process soon leads to bearing failure in the turbocharger.
An interim and incomplete solution to the above problem was provided by the inclusion of a hydraulic accumulator with a check and metering valve in the oil supply conduit between the engine and turbocharger. During engine operation this accumulator filled with pressurized oil. Upon engine shutdown the oil was allowed to flow only to the turbocharger at a controlled rate to provide bearing and shaft cooling while the remainder of the turbocharger cooled down. However, the frequent shutdowns and restarts to which automotive passenger vehicles are sometimes subjected does not allow sufficient time for filing of the accumulator. Under these conditions failure of the turbocharger may be accelerated.
Another more recent and more successful solution to the above problem has been the provision of a liquid cooling jacket in a part of the turbine housing adjacent to the turbine housing section. Liquid engine coolant is circulated through the jacket during engine operation by the cooling system of the engine. Following engine shutdown the coolant remaining in the jacket provides a heat sink so that residual heat from the turbine housing section does not increase the shaft and bearing temperatures to undesirably high levels. U.S. Pat. Nos. 4,068,612 of E. R. Meiners, and Re. 30,333 of P. B. Gordon, Jr., et al, illustrate examples of this conventional solution to the problem.
However, this latter class of turbochargers all require that engine coolant be piped to and from the turbocharger. This is usually accomplished with flexible hoses which complicate and increase the cost of the original installation of the turbocharger. Also such plumbing requires additional maintenance and may be subject to coolant leakage which could disable the vehicle.
SUMMARY OF THE INVENTION
In view of the above, it is an object for the present invention to provide a method of limiting the temperature at the shaft and bearings of a turbocharger following engine shutdown without the use of liquid engine coolant and the attendant plumbing that such coolant use involves.
A further object is to provide a turbocharger which except for the necessary air, exhaust gas and lubricating oil connections with the engine is a unit unto itself and is not reliant upon the cooling system of the engine to prevent overtemperature conditions within the turbocharger.
The present invention provides the method of controlling the heat transfer within a turbocharger following engine shutdowns by providing a captive mass of heat conductive and heat absorptive material which during turbocharger operation exists in a relatively low energy molecular state and which upon engine shutdown and the attendant cessation of cooling oil flow both absorbs residual heat from the turobcharger turbine housing section with an attendant phase change, and provides a heat transfer path from the turbine housing section to other relatively cool portions of the turbocharger bypassing the heat transfer path including the shaft and bearings where oil coking may occur.
More particularly, the present invention provides a turbocharger including a housing journaling an elongate shaft therein, a turbine drivingly carried at one end of said shaft and a compressor drivingly carried at the opposite end of the shaft, a turbine housing section defining an exhaust gas inlet to and an exhaust gas outlet from the turbine, an inlet housing section similarly providing an air inlet to and an air outlet from the compressor, the housing defining a closed cavity substantially surrounding the shaft and extending between the turbine housing section and inlet housing section, and a determined quantity of material captively disposed in the cavity which during turbocharger operation at a normal temperature exists at a first lower molecular energy level and with increasing temperature during transfer thereto of residual heat from the turbine housing section absorbs the heat with an attendant change of phase to a second higher molecular energy level.
BRIEF DESCRIPTION OF THE DRAWINGS
FIG. 1 is a longitudinal somewhat schematic view partly in cross section of a turbocharge embodying the present invention;
FIG. 2 is a fragmentary cross sectional view taken along line 2--2 of FIG. 1;
FIG. 3 is a fragmentary cross sectional view taken along line 3--3 of FIG. 1; and
FIG. 4 is a fragmentary cross sectional view taken along line 4--4 of FIG. 1.
DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENT
With reference to FIG. 1, a turbocharger 10 includes a housing generally referenced with the numeral 12. Housing 12 includes a center section 14 receiving a pair of spaced apart journal bearings 16, 18, and rotatably receiving therein an elongate shaft 20. A turbine wheel 22 is attached to or integrally formed with one end of shaft 20. At the opposite end of shaft 20 a compressor wheel 24 is carried thereon and drivingly secured thereto by a nut 26 threadably engaging the shaft.
A turbine housing section 28 mates with the center section 14 and defines an exhaust gas inlet 30 leading to a radially outer portion of the turbine wheel 22. The turbine housing section also defines an exhaust gas outlet 32 leading from the turbine wheel 22. Similarly, a compressor housing section 34 mates with the housing center section 14 at the end thereof opposite the turbine housing section 28. The compressor housing section 34 defines an air inlet 36 leading to the compressor wheel 24, and an air outlet (not shown) opening from a diffuser chamber 38.
The turbocharger center section 14 also defines an oil inlet 40 leading to the bearings 16, 18 via passages 42, 44, and an oil drain gallery 46 leading from the bearings to an oil outlet 48. Also defined within the housing center section 14 is a closed cavity 50 which is best depicted viewing FIGS. 2-4. The cavity 50 extends axially between the compressor housing section and turbine housing section of the housing 14. Cavity 50 also extends circumferentially over the top and part way down each side of the shaft 20, viewing FIGS. 3 and 4. Thus, it can be envisioned that cavity 50 envelopes the shaft 20 and bearings 16, 18 somewhat in the shape of a saddle.
Disposed within the cavity 50 is a predetermined quantity of a material 52 selected with a view to, among other factors, it heat transfer coefficient, its chemical stability under thermal cycling, its cost, and its heat of fusion or other change of phase heat capacity. Also of particular importance with respect to the material 52 is the temperature at which such change of phase heat absorption and heat release takes place.
During manufacturing of the turbocharger 10, the material 52 is loaded into the cavity 50 preferably in a solid pellet or granular form via a port 54 opening thereto. After the cavity 50 is substantially filled with material 52, the port 54 is permanently closed by a plug 56 which threadably engages the housing center section 14. By way of example only, the plug 56 may be removably secured to housing section 14 by an anaerobic adhesive, or may be permanently secured thereto as by welding. In either case, the plug 56 is intended to permanently close the port 54 so that the cavity 50 is closed for the service life of the turbocharger 10. Consequently, the material 52 is permanently captured within the cavity 50. It will be noted that because the material 52 is loaded into cavity 50 in the form of pellets or granules, it has been so illustrated in the drawing figures. However, after the first time turbocharger 10 is operated on an engine and following hot shutdown thereof, the material 52 exists in cavity 50 as a fused mass.
Having observed the structure of turbocharger 10, attention may now be directed to its operation. During operation of an internal combustion engine (not shown) associated with turbocharger 10, high temperature and pressure exhaust gasses enter the housing 12 via exhaust gas inlet 30. These exhaust gasses flow from inlet 30 to outlet 32 while expanding to a lower pressure and driving turbine wheel 22. The turbine wheel 22 drives shaft 20 which also carries compressor wheel 24. Consequently, compressor 24 draws in ambient air via inlet 36 and discharges the same pressurized via an outlet (not shown) communicating with chamber 38. The exhaust gasses flowing within the turbine section of housing 12 also act as a substantially continuous source of heat which is transferred to housing 12 and turbine wheel 22 so long as the engine and turbocharger 10 are in operation. Consequently during operation of the turbocharger 10, heat is almost continuously conducted from the hot turbine housing section 28 and turbine wheel 22 to the cooler portions of the turbocharger. This heat transfer occurs by conduction along shaft 20 and turbine housing center section 14, leftwardly viewing FIG. 1.
At the same time, a flow of relatively cool lubricating oil is received via inlet 40 and passages 42, 44. This cooling oil flow by its traverse through passages 42, 44, its flow from bearings 16, 18, and its flow across the internal surfaces of oil drain gallery 46 absorbs heat from and cools the turbocharger 10. The turbocharger 10 also liberates heat to its environment by radiation and convection from external surfaces. Also, heat may be transferred to air traversing the compressor wheel 24 and flowing to the air outlet via chamber 38. The summation of these heat transfer effects results in the bearings 16, 18 operating at temperatures low enough to prevent oil coking therein. Further the material 52 is maintained in a relatively low energy molecular state.
Upon shutdown of the engine supplying exhaust gasses to inlet 30, both the source of heat energy and the source of cooling oil flow to the turbocharger cease to operate. However, both the turbine housing section 28 and turbine wheel 22 are hot and hold a considerable quantity of residual heat. This residual heat is conducted to the cooler parts of the turbocharger much as heat was conducted during operation thereof. However, no cooling oil flow is now present. Consequently, the temperature of shaft 20 and center housing 14 progressively increase over their normal operating temperatures. This temperature increase, if uncontrolled could result in temperatures at bearings 16, 18, and particularly at the latter, which would degrade or coke the residual oil therein.
In order to control the heat transfer within turobcharger 10, the material 52 serves both to conduct heat from the hot turbine housing section 28 toward the cooler compressor housing section 34 via a path which is apart from the shaft 20 and bearings 16, 18, but also to absorb heat energy by a molecular change of phase. The material 52 is selected with a view to the normal expected operating temperatures of center housing 14 so that at a certain higher temperature a change of phase to a higher energy state takes place. This change of phase is accompanied by the absorption of a considerable quantity of heat. As a result, the temperatures at bearings 16, 18 do not reach levels which would coke the oil therein. Of course, with the passage of time the entire turbocharger 10 cools as it liberates heat to its surroundings.
By way of example, the applicant has discovered that an alloy of tin and lead which is used as common low-temperature solder will, if employed as the material 52, give surprisingly good results. A test of the turbocharger of FIG. 1 with the cavity 50 empty resulted in heat soaking from the turbine housing and turbine wheel to bearings 16 and 18 so that maximum temperatures of 450° F. and 640° F., respectively, were reached at each bearing. There temperatures compare with normal operating temperatures of 225° F. and 310° F., respectively, and are high enough at bearing 18 to coke the residual oil therein. These temperatures are comparable to those which would be expected in a conventional turbocharger with no center housing cooling of any type.
On the other hand, when the solder alloy was employed in cavity 50, the maximum bearing temperatures were 480° F. and 525° F., respectively, during a heat soak test under otherwise the same conditions as above. Significantly, the maximum temperature reached at bearing 18 was 115° F. lower than that experienced without the material 52 is cavity 50. The 30° F. higher temperature reached at bearing 16 is an indication that even though the material 52 absorbs a significant quantity of heat during its phase change it also conduits heat to the cooler portions of the turbocharger. This latter effect of the material 52 in cavity 50 is of considerable benefit itself because the cool compressor housing section is capable of absorbing considerable residual heat. Also, this compressor housing section also provides additional radiation and convection cooling surface area which is an aid to rapid cooling of the turbocharger. All of these effects in concert cooperate to limit the maximum temperature reached at bearing 18 so as to prevent oil coking therein.
Upon restart of the engine associated with turbocharger 10, if significant residual heat yet remains, the initial air flow through compressor housing section 34 will dissipate the heat therein. Likewise, the initial oil flow through the center housing section 14 will quickly lower the temperature therein to normal levels. As a result of this cooling upon a return to normal operation of the turbocharger, the material in cavity 52 is also cooled and experience a heat-releasing phase change to its lower-energy molecular condition. The heat released by this cooling phase change is substantially absorbed by the cooling oil flow through the center housing. As a result, the turbocharger 10 well endures frequent shutdowns and restarts of its associated engine.
An advantage of the present invention in addition to the elimination of engine coolant plumbing to the turbocharger and attendant simplified installation and maintenance, is its particular utility with air-cooled engines. These engines have no liquid engine coolant which could be used in the conventional way to cool a turbocharger. Consequenlty, turbocharger applications to these engines have conventionally involved many problems. The present invention is believed to provide a substantially complete solution to this difficult turbocharger application problem.
While the present invention has been depicted and described with reference to one preferred embodiment of the invention, no limitation upon the invention is inferred by such reference, and none is to be implied. The invention is intended to be limited only by the spirit and scope of the appended claims, which also provide a disclosure and definition of the invention.
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A turbocharger includes spaced apart turbine housing and compressor housing sections which are connected by a center housing section. The center housing section journals an elongate shaft carrying at opposite ends thereof a compressor wheel and a turbine wheel rotatable in the respective housing sections. The center housing section also defines a closed cavity captively receiving a material conductive of heat and which transitions between lower and upper molecular energy levels during hot soak of the turbocharger following engine shutdown to control bearing temperature at the shaft.
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CROSS-REFERENCE TO RELATED APPLICATION
Not Applicable
STATEMENT REGARDING FEDERALLY SPONSORED RESEARCH AND DEVELOPMENT
Not Applicable
BACKGROUND OF THE INVENTION
1. Field of the Invention
The invention relates to waterway channel maintenance. More specifically, the invention relates to channel dredging, particularly channel side dredging.
2. Description of the Prior Art
Shoaling and the buildup of silt and mud are common problems around docks, ports and channels, and frequent dredging is required to maintain sufficient depth of water for use by ships, barge and other waterborne vehicles. Many types of dredge equipment have been developed, including cutter-head dredges, bucket or shovel dredges, and side trailing hopper dredges. These dredge systems use mechanical manipulation of the dredged material, either by pumping or scooping, to transfer the material away from the area being dredged, e.g. a dock or channel side. An example of a dredging system using pumping is disclosed in U.S. Pat. No. 4,352,251. This reference discloses a hand operated suction dredge head and a hydraulic submersible pump assembly. Water and sludge is driven through a conduit and pump and is discharged to a location remove from the dredge head. While these systems are somewhat effective in dredging level surfaces, the angularity of channel sidewalls can present challenges to the operation of certain types of these dredges.
Another problem present with prior dredge systems is that they are destructive to bottom dwelling creatures because of the mechanical action of the dredging. Also associated with mechanical dredging systems is the problem of finding a location for the dredged material after it has been removed. Very often the ship from which the dredging is taking place must act as a temporary storage area for the removed material. This necessitates a larger ship size than otherwise needed, thereby requiring more crew and a higher United States Coast Guard license rating to operate the vessel. An additional special problem with systems that transfer material by pumping is that the slurry dredged up and pumped through the pumps is very abrasive. This abrasiveness causes the pumps to wear at a higher rate than pumps just pumping water.
A more recent system, referred to as water injection dredging (WID), has shown advantages in dredging channel side buildup. Generally, WID involves injecting water into the material, liquefying it and causing it to flow under its own weight to deeper adjacent water. An example of WID is disclosed in U.S. Pat. No. 4,604,000. While this technique can be useful for higher level side dredging, it is largely ineffective for bottom dredging where there is no lower runoff level.
Another problem associated with both WID and mechanical dredging systems is that they produce a layer of "fluff" or low density mixture of bottom material and water just above the dredged bottom. When survey equipment tries to measure the depth of the bottom the depth recording equipment records the fluff layer rather than the true dredged bottom.
SUMMARY OF THE INVENTION
It is therefore an object of the invention to provide a dredging system that can return dredged material back into the water column where it can be carried away by currents and be allowed to settle out in areas far away from the dredged area.
It is another object of the invention to provide a dredging system that minimizes the creation of fluff that interferes with accurate measurement of the true depth of the dredged bottom.
It is a further object of the invention to provide a dredging system that does not require dredged material to be brought on board the dredging ship, thereby allowing use of smaller ship sizes.
It is still another object of the invention to provide a dredging system that does not excessively wear pumps used in the dredging operations by exposing the pumps to abrasive material.
It is still a further object of the invention to provide a dredging system that does not mechanically work the dredged material so as to be less destructive to bottom-dwelling creatures.
These and other objects of the invention are achieved by a dredging system for removing material from submerged ground surfaces, such as the bottom or sides of a water channel. The system includes a dredge head housing having a pair of preferably substantially parallel side walls, a tail piece and a top cover. The housing defines an agitation chamber into which material is received from an intake opening between the front ends of the side walls and top cover.
A feed line connects to the housing and supplies pressurized fluid, such as water, to a fluid manifold connected to the housing and within the agitation chamber. The fluid manifold contains cutting outlets for discharging the pressurized fluid onto the material to liquefy the material. The fluid manifold also includes lifting outlets for discharging the pressurized fluid so as to urge the liquefied material towards a riser chute. The riser chute extends from a discharge opening in a top cover of the housing and extends above the housing and upwardly discharges the liquefied material into the water column.
According to a further aspect of the invention, evenly-spaced cutting outlets are positioned above and adjacent the intake opening. These cutting outlets are oriented to spray the pressurized fluid downward onto the incoming material across the entire width of the intake opening to liquefy the material.
Additional, preferably evenly-spaced, cutting outlets can also be positioned adjacent both side wall leading edges and oriented to spray the pressurized fluid in front of the side wall leading edges. The cutting jets effectively create a channel for each side wall, reducing the drag created by towing the dredge head housing through the material and allowing the dredge head to track better through the material.
According to another aspect of the invention, the fluid manifold extends along both side walls and contains further cutting outlets and/or lifting outlets. The additional jets of fluid pressurize the chamber and contribute to the agitation and liquification of the incoming material to facilitate discharge through the chute into the vertical column above. The cutting outlets are oriented to spray the pressurized fluid laterally into the agitation chamber, and the lifting outlets are oriented to spray the pressurized fluid towards the discharge chute. A lift outlet may also be positioned adjacent the discharge opening and oriented to spray the pressurized fluid into the riser chute.
According to still another aspect of the invention, the tail piece is preferably hinged to a trailing edge of the top cover. The tail piece may also include a tail piece weight attached to the tail piece adjacent the tail piece bottom edge to urge the tail piece bottom edge to contact the bottom of the body of water. The housing may also include a front seal plate hingedly connect to a top cover leading edge.
According to a further aspect of the invention, the feed line and fluid manifold also receive a pressurized gas and liquid mixture and the fluid manifold provides outlets for injecting the gas and liquid mixture into the agitation chamber.
The system also preferably includes an articulated coupling that permits angling of the dredge head relative to the feed line. With such construction, the dredge head can be utilized to dredge not only horizontal surfaces such as channel bottoms but also angled surfaces typically encountered in channel sides.
Thus, the invention provides a dredging system that is capable of removing material from a variety of submerged surface environments while avoiding or reducing many of the drawbacks suffered with prior systems. Further details of the system are set forth in the following detailed description.
BRIEF DESCRIPTION OF THE DRAWINGS
A further understanding of the invention can be gained from a review of the following detailed description together with the accompanying drawings, wherein:
FIG. 1 is a view of a dredging system according to the invention being operated from a dredging vessel;
FIG. 2 is a perspective view of a dredge head according to the invention in operation;
FIG. 3 is a sectional side view of the dredge head;
FIG. 4 is a front elevation of the dredge head; and
FIG. 5 is an exemplary fluid manifold for use in the dredge head housing.
DETAILED DESCRIPTION OF PREFERRED EMBODIMENTS
FIG. 1 illustrates an exemplary dredging system according to the invention. The system 10 includes a dredge head housing 12, and attached to the housing 12 are lift lines, a feed and tow line 14, and a riser chute 16. The dredge head housing 12 removes material 18 from a submerged ground surface such as the bottom of a channel 20 and injects the material out of the riser chute 16 into the water column 22 above the dredge head housing 12. The system 10 is supported by a vessel 24, which can include a tug, and in any event can be a smaller class vehicle than used with prior dredging systems in view of the reduced pumping and material storage requirements of the inventive system. The support system can include a lift boom 26 supporting lift lines 28 to control the depth of the dredge head housing 12. The dredge head housing 12 can be propelled by the feed and tow line 14 extending from the housing 12 to the vessel 24. The feed and tow line 14 can be constructed using steel tubing or reinforced hose capable of operating under tensile forces in towing the dredge head housing 12. The dredge head housing 12 is supplied with pressurized fluid, that can include water, air or both through the line 14 from a suitable pumping system 30 on board the vessel 24. The dredge head housing 12 could alternatively be pulled by tow lines separate from a feed line 14. In embodiments supplying both air and water, the feed line 14 can provide either a single conduit through which both air and water are supplied or separate, bundled lines can be provided to transport the air and water separately to the dredge head housing 12.
The dredge system 10 is used to transport a variety of ground surface materials including silt and particularly compact mud. FIG. 2 illustrates a dredge head system 10 according to the invention, forming a dredge line 32 in the channel 20 next to a previously dredged line 34. As the housing 12 is dragged through the material 18, a section of the material, referred to as a "cake" 36 enters an agitation chamber 38 formed within the housing though an intake opening 40. The incoming material 36 is fluidized within the chamber 38 and exhausted under pressure through the chute 16 for displacement in the water column 22 above.
Referring to FIGS. 3 and 4 together, the intake opening 40 is bounded by two preferably parallel side walls 42, the ground surface of material 18, and the leading edge 44 of the top cover 46. The rear opening 48 between the side walls 42 is closed by a tail piece 50. The agitation chamber 38 is sealed on both sides by the side walls 42, sealed in the rear by the tail piece 50, and sealed in the front by a combination of the cake of material 36 and the leading edge 44 of the top cover 46. The top of the agitation chamber 38 is sealed by the top cover 46 except for a discharge opening 52 leading to a riser chute 16.
The bottom of the agitation chamber 38 may be sealed by a bottom plate (not shown) spanning between the side walls and the tail piece, or in a presently preferred embodiment, by the ground surface 18. The preferably open bottom as shown enables the dredge head housing 12 to more easily dig into a material cake 36, even when the cake has a height that is higher than the dredge head housing.
The tail piece 50 is preferably hinged with hinge 51 to the trailing edge of the top cover 46. Advantageously, this construction allows the tail piece 50 to maintain contact with the material 18 even when the top surface of the material 18 is undulating with respect to the top cover 46. To further that purpose, a tail piece weight 54 can be added to the tail piece 50 adjacent the bottom edge of the tail piece 50 to urge the bottom edge of the tail piece 50 to contact the top surface of the material 18.
Connected preferably to the interior of the housing 12 is a fluid manifold 56. The fluid manifold 56 contains a pressurized fluid, preferably water, received from the feed line 14 and injects the water through outlets 58, 60, 62 in jets into the agitation chamber 38. The pressurized fluid has two primary functions. The first function is to liquefy the cake of material 36, and the second function of the pressurized fluid is to pressurize the chamber 38 and urge the liquefied material into the riser chute 16. The cutting and pressurization functions of the manifold 56 can further be enhanced by the supply of air that is mixed with the water or supplied through a parallel manifold system (not shown).
The line 14 can be connected to the manifold 56 in a manner that permits angled movement of the dredge head housing 12 relative to the line 14. An articulated coupling can include a pivot 64 to permit forward and rearward pitch of the housing 12, thereby permitting variation due to irregularities in the ground surface 18. The coupling can further include a swivel 66 to permit side to side roll, which is effective in enabling the dredge head housing 12 to be used on side angled surfaces commonly found along channel sides.
To liquefy the cake of material 36, the cutter outlets 58, 60 are disposed on the fluid manifold 56 and oriented so as to direct the pressurized fluid onto the cake of material 36 entering into the agitation chamber 38. When pressurized fluid is directed onto the material 36, the material is loosened, fluidized, and then displaced. In the presently preferred embodiment of the invention, a row of evenly-spaced cutter outlets 58 are disposed on a portion of the fluid manifold 56 positioned adjacent the top edge 64 of the intake opening 40 and oriented downward onto the incoming cake of material 36. It should be understood, however, that any location and/or orientation of the cutter outlets 58 are acceptable so long as the cutter outlets 58 are directed onto the incoming cake of material 18. An additional embodiment of the invention includes legs 68 of the fluid manifold 56 positioned adjacent the leading edge of each side wall 42. Upon these legs 68 are disposed a row of evenly-spaced cutter outlets 60 oriented to laterally spray the pressurized fluid. This lateral spray of pressurized fluid further liquefies the incoming material 18.
The action of injecting pressurized fluid into the substantially sealed agitation chamber 38 creates a pressure differential between the fluid contained within the agitation chamber 38 and the water outside the housing 12. Also, because the agitation chamber 38 is connected to the outside water through the riser chute 16, the pressurized fluid in the agitation chamber 38 will flow from the agitation chamber 38, up the riser chute 16, and into the water column above the housing 12.
Lift outlets 62 disposed on the fluid manifold can also be used to urge the liquefied material from the agitation chamber 38 into the riser chute 16. One way the lift outlets 62 do so is by introducing additional pressurized fluid into the agitation chamber 38. This further increases the pressure differential. Also, the lift outlets 62 are directed toward discharge opening 52 which then creates a current of pressurized fluid that transports liquefied material into the riser chute 16. An alternative embodiment of the invention includes a discharge opening lift outlet 70 on the fluid manifold 56 centrally positioned and facing within the discharge opening 52. The discharge opening lift outlet 70 is oriented to inject pressurized fluid into the riser chute 16.
The discharge of the agitated, liquefied material out of the riser chute 16 takes advantage of the existing currents in the waterway to carry the material away from the dredged area. In the preferred arrangement of trailing the dredge head behind the stern of the support boat (see FIG. 1), the "quick water" of the boat propellers can further assist in agitating and distributing the discharged material. The discharge of the riser chute 16 can alternatively be routed through appropriate pumping to a material collection vessel, such as a barge trailing the support boat and dredge head housing (not shown).
The liquefied material is ejected from a top opening in the riser chute 16. Significantly, by ejecting the liquefied material into the water column a distance above the housing, the liquefied material can be carried farther by the natural action of the water (e.g. river flow, currents, tides, etc.). Thus, the liquefied material can be carried into deeper water located relatively far away from the area being dredged. In the distant water, material will later settle out. This broad range transfer process allows dredging in areas that are locally the deepest area and would otherwise be the natural settling point for liquefied material.
This transfer process also reduces the generation of "fluff." Fluff refers to suspension of ground material, such as mud and silt, directly above the compact ground surface in a less dense mixture with water. Fluff can interfere with depth measurements by signaling a false ground position to detecting equipment. This fluff is typically created by dredging operations that break up the ground substantially in the dredged area during the dredging process. By exhausting the dredged material substantially completely away from the dredged area, the present invention reduces or eliminates fluff.
The presently preferred riser chute includes just one chute. However, more than one chute or pipe may be used to eject the liquefied material into the water column above the housing. Because of drag on the riser chute, the housing is urged downward into the material. This allows for a better seal of the agitation chamber. The riser chute may or may not be slightly angled backwards from the discharge opening to the top chute opening. This angling has the effect of reducing drag as the housing is dragged forward.
As shown particularly in FIG. 4, a plurality of evenly-spaced front cutter outlets 60 are disposed on portions of the fluid manifold positioned adjacent the leading edges of both side walls 42. The front cutter outlets 60 are oriented to spray pressurized fluid directly in front of the leading edges of the side walls 42. In doing so, the material directly in front of the leading edges of the side walls 42 is fluidized and a channel is created in the material. This channel allows the housing 12 to be dragged through the material with less drag. Also, the channel allows the housing 12 to track better through the material.
Referring to FIG. 5, an embodiment of a manifold for use in connection with the dredge head system of the invention is shown, separate from the associated dredge head housing. The manifold 56 includes an intake conduit 72 for receipt of air and/or water from the feed line 14 (FIG. 1). The intake conduit 72 mergers with transfer conduits 74 for transport of water and/or air to the side legs 68, a top span 76 and bottom legs 78 for release through cutter outlets 58, 60 and 62. The discharge opening lifting outlet 70 is also connected centrally along the initial transfer conduit 74. The manifold 56 can be constructed using tubular steel or other material that is then mounted within the housing. Alternatively and preferably, the various conduits can be welded as half rounds, for example, to the adjacent surfaces of the dredge head housing, particularly along the legs providing cutting and lifting outlets.
Referring again to FIG. 1, the side walls of the housing 12 can be semi-permanently connected, with bolts through bolt holes 80 for example, to similar dredge head housings to provide wider material dredging in ganged fashion. This gang mounting of the housings allows for more material to be dredged in a single pass of the housings through the material.
The dredge head housing 12 can be constructed of a suitably strong and durable material such as steel and fabricated from welded components. The dredge head housing 12 can be dimensioned to a width and depth of about 10 feet with a height of 4 feet. The riser pipe or tube can have a length of 8 to 10 feet. Other dimensions to meet the particular circumstances can also be used.
Although preferences for the construction of embodiments of the invention have been described with a relatively high degree of detail. It should be understood that the scope of the invention is not to be limited by such examples, but rather by a proper interpretation of the following claims.
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A dredging system for removing material from a submerged ground surface includes a dredge head housing having an enclosed, pressurized agitation chamber into which the material to be removed is received from an intake opening. Connected to the housing is a feed line that supplies pressurized fluid, such as water, air or both, to a fluid manifold connected to the housing and within the agitation chamber. The fluid manifold contains cutting outlets for discharging the pressurized fluid onto the material to liquefy the material and lifting outlets for discharging the pressurized fluid so as to urge the liquefied material towards a riser chute. The riser chute is connected to a top cover of the housing and extends above the housing and upwardly discharges the liquefied material into the water column of the body of water.
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BACKGROUND OF INVENTION
This application is a continuation-in-part of my two earlier applications, Ser. Nos. 520,733 filed May 9, 1990 now U.S. Pat. No. 4,995,870 and 595,238 filed Oct. 10, 1990 now U.S. Pat. No. 5,035,703
RELATED APPLICATIONS
U.S. application, Ser. No. 520,733, filed May 9, 1990, entitled "DISPOSABLE SYRINGE WITH RETRACTABLE NEEDLE", now U.S. Pat. No. 4,995,870.
U.S. application, Ser. No. 595,238, filed Oct. 10, 1990, entitled "DISPOSABLE SYRINGE NEEDLE AND SCALPEL HOLDER", now U.S. Pat. No. 5,035,703.
This invention relates to safe handling of tools used by a dentist, and in particular to holders for scalpels and syringes and other tools and implements used by a dentist in his normal practice.
The referenced related applications Ser. Nos. 520,733 and 595,238, whose contents are hereby incorporated by reference, described devices for holding and handling syringes and scalpels in such manner that the disposable puncturing or cutting parts cannot be touched after use by the dental practitioner or his assistant.
These applications contemplated a special stand mounted on a cabinet or other convenient work surface in the treatment room.
SUMMARY OF INVENTION
It is an object of the invention to provide at a more convenient location means for supporting dental tool holders, preferably of the general type disclosed in my prior applications for safe handling of syringes and scalpel blades.
Another object of the invention is an improved holder for safe handling of a dental syringe.
According to one aspect of the invention, a mounting support device is provided that is constructed to mount on the dentist's instrument panel in his treatment room. The device is constructed to support a grooved member configured to receive one or more tool holders. Preferably the tool holders each have multi-sided mounting bases so that they can be supported on the grooved member in several different positions most convenient to the user.
In accordance with a further feature of this aspect of the invention, the grooved member is constructed to support a cup holder. The cup can be conveniently used to dispose of used dressings or implements.
In accordance with another aspect of the invention, a novel syringe holder is provided with an opening leading to a tapered threaded member mounted internally of the holder. The tapered threaded member is configured to receive a variety of sizes of standard syringe needle protective covers or sleeves which upon rotation can be temporarily locked to the tapered threaded member. This makes it very easy to detach the syringe from its sleeve, use the syringe, return it to and reattach it to its sleeve, and then by reverse rotation remove the syringe with its attached sleeve for safe disposal of the used needle.
The various features of novelty which characterize the invention are pointed out with particularity in the claims annexed to and forming a part of this disclosure. For a better understanding of the invention, its operating advantages and specific objects attained by its use, reference should be had to the accompanying drawings and descriptive matter in which there are illustrated and described the preferred embodiments of the invention.
SUMMARY OF DRAWINGS
In the drawings:
FIG. 1 is a perspective view of a conventional dental instrument panel having mounted on its side one form of mounting support device in accordance with the invention;
FIG. 2 is a perspective view of one form of crucible in accordance with the invention;
FIG. 3 is an exploded perspective view of the support bracket of the device of FIG. 1 including the grooved tool holder;
FIG. 4 is a perspective view of a modified tool holder in accordance with the invention for mounting on a work surface;
FIG. 5 is an elevational cross-section view of a syringe holder in accordance with the invention;
FIG. 6 is a partly cross-sectional view of the tapered threaded member used in the syringe holder of FIG. 5, shown supporting a syringe.
DETAILED DESCRIPTION OF PREFERRED EMBODIMENTS
FIG. 1 illustrates a typical instrument panel of the type commonly found in dentists' offices. The panel 10 is typically mounted on a floor stand adjacent to the patient's chair, is movable to various positions, and supports a variety of tools 11, 12, only two of which are briefly outlined. Typical tools include a high-speed handpiece, aspirator, air spray, water spray, mirror, etc. The details are unnecessary to the present invention.
In accordance with the invention, a mount 15 for a bracket 12 is secured to the side 14 of the instrument panel 10. The mount 15 comprises a plate 16 screwed 17 to the panel side. Extending from the mount are two posts 20 across which is mounted a support bar 21. The support bar 21 accomodates one or more tool holder supports 22, 23, 24 in accordance with the invention. Some instrument panels made by certain manufacturers come already equipped with a bracket 12 for other purposes. That bracket can be used with the holders of the invention. Otherwise, it is necessary to provide such a bar bracket 12 on the panel.
FIG. 3 illustrates the mounting means for one of the holder supports 22. The other holder supports would be similar. It comprises a member, preferably of metal, having at one end a generally C-shaped recess or opening 26 sized to fit closely around the bar 21, yet allow sliding movement along the bar. A set screw 27 at the bottom can be used to fix the position of the holder support 22 on the bar 21.
The holder support 22 comprises a dovetail groove 28 which extends across the upper surface of the holder support. A small depression 29 at the groove center is for receiving a ball detent on a tool holder. The tool holder that can be mounted in the groove 28 are of the same basic types discussed in my prior application, Ser. No. 595,238, but they must have a multi-sided or polygonal base configured to slide into the groove 28 in any of several positions so that the tool holder can occupy different orientations for the dentist's convenience.
FIG. 1 illustrates two dental tool holders 31, 32 mounted, respectively, in the aligned grooves 28 of two adjacent support members 22, 23. Alternatively, a single support member can be substituted which is wide enough to hold 2, 3 or more tool holders 31, 32. The tool holder 31 can be, for example, a syringe holder as illustrated in FIG. 8 of application, Ser. No. 595,238, but fitted with a hexagonal base as illustrated in FIG. 10 of that application. The second tool holder 32 can be a scalpel holder of the type illustrated in FIG. 12 of my prior application, again fitted with a hexagonal base. The top half can be separated and removed from the bottom half, so that the used blade can be removed and disposed of allowing the holder to be reused. Or, alternatively, the holder can be provided at the bottom of its hexagonal base with a removable plug to seal off the bottom cavity containing the used blade. Removing the holder and the plug allows disposal of the used blade and re-use of the holder.
FIG. 2 illustrates another device 35 that can be mounted in the groove 28 of the support 22, 23 or 24. This device 35 is a crucible, used for mixing and holding tooth filling material in a small cup or well 36 at the top. It has a hexagonal base 37 that extends beyond the crucible body, and has a width 38 across its parallel side and a thickness 39 so that the base 37 will slideably fit within the groove 28, with the base 37 lying under the inturned groove edges. Not shown in FIG. 2 is a spring biased ball detent which can be added at the bottom of the base 37 which engages the recess 29 to hold the device 35 in place, even if the instrument panel is moved. The tool holders 31, 32 could have similar means to hold it in position, or rely on friction in the dovetail groove. Since the device 35 is held tightly in place, the user need use only one hand to mix and use the filling material while in the device 35. Other devices such as dappen dishes or the like, capable of holding various items can also be conveniently mounted on the supports 22-24.
FIG. 5 illustrates another tool holder 42 with a widened hexagonal base 43 configured to fit the groove 28 of the support 22. A ball detent 44 is shown here at the base bottom. The base 43 is angled relative to the axis of the body 45 of the holder. A suitable angle is 20°-40°. Since the base 43 can slide into the groove 28 in 6 different positions, it means that the body 45 can occupy different orientations relative to the support 22. FIG. 1 shows two of the six possible tool holder orientations.
FIG. 5 also discloses a novel form of safe syringe holder. The typical commercial syringe 50 (FIG. 6) comprises a metal barrel 51 for receiving a cartridge (not shown) storing medication. A narrow end 52 receives the threaded hub of a needle (not shown) which projects forwardly. A plastic protective cover or sleeve 53 is friction-fitted or threaded onto the barrel end 52 over the needle. My earlier filed application shows the typical construction and it need not be repeated here. It need only be mentioned that by grasping the cover 53 and rotating it or the syringe 50 relative to one another, the sleeve 53 can be removed exposing the needle for use. For safety's sake, for the reasons given in my earlier cases, the used needle must be re-covered for safe disposal, preferably without hand-holding the cover 53.
In this aspect of the invention, a tapered, threaded member 55 is mounted about midway within an elongated opening 56 in the holder body 45. The threaded member 55 has a wide end 57 and a narrow end 58 which opens into a cavity 59 at the holder bottom. The member 55 can be a spiral metal spring of the type used in electrical wire nuts. The threads are used to bite into the plastic cover so it will be gripped when the syringe is first inserted in the holder 42 by the dentist. Yet, the syringe can be rotated out of the holder in the same way that wire nuts can be attached and detached from twisted wire ends.
The taper is important to handle the large variety of cover shapes and sizes. I have found that a wide opening 57 of about 0.36 inches, a narrow opening 58 of about 0.15 inches, with an overall length of about 15/16 inches, is sufficient to handle virtually all the conventional sized syringe needle covers. FIG. 6 shows how the spring 55 (the holder 45 is omitted for clarity) can grip the needle cover 53.
In operation, the dentist inserts the syringe with fresh needle and cover into the holder 45, and rotates slightly counter clockwise (ccw) for the threads to grip the cover. Then the dentist can continue to rotate the syringe 50 ccw which will allow it to be removed from the cover 53 which remains behind in the holder 42. The dentist can always place the syringe, with the same patient, back into its held cover 53, and again remove and use. In other words, the needle cover 53 is now functioning as a syringe holder. When the procedure is completed, the dentist reinserts the syringe for the last time into its cover 53, rotates cw to lock the cover 53 to the syringe hub 52, and by continuing cw rotation can now remove the syringe 50 with attached cover 53 from the holder 42. The dentist can now easily and safely remove the used needle protected by the cover 53 for safe disposal. With the holder 42 fixed in place, the entire operation can be performed by the dentist or his assistant using only one hand.
FIG. 4 illustrates a modified stand for a tool holder of the types disclosed at 31, 32, 35 or 42. It comprises a plate 65 which may be screwed 66 down on a counter top 67 in the dental office. A dovetail groove 68 extends across the top. In this case, the groove ends can be widened 69 for easy attachment and detachment of the holder polygonal base. Two depressions 70 are shown for ball detents so that two tool holders can be slid side-by-side into the groove 68. A stop 71 can be provided if desired for the tool holders.
While the invention has been described in connection with preferred embodiments, it will be understood that modifications thereof within the principles outlined above will be evident to those skilled in the art and thus the invention is not limited to the preferred embodiments but is intended to encompass such modifications.
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A tool holder for mounting on the instrument panel in a dentist's office contains a grooved surface for receiving one or more syringe or scalpel or other implement holders. These holders have hexagonal bases for mounting in one of several different positions. A novel syringe holder employs a tapered threaded member for gripping the protective cover on the needle so that the cover can serve as the syringe holder.
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FIELD OF THE INVENTION
The present invention relates to a valve timing control device and, in particular, to the valve timing control device for controlling an angular phase difference between a crank shaft of a combustion engine and a cam shaft of the combustion engine.
BACKGROUND OF THE INVENTION
In general, the valve timing of an internal combustion engine is determined by valve mechanisms driven by cam shafts according to either a characteristic or a specification of the internal combustion engine. Since a condition of the combustion is charged in response to the rotational speed of the combustion engine, however, it is difficult to obtain an optimum valve timing through the whole rotational range. Therefore, a valve timing control device which is able to charge a valve timing in response to the condition of the internal combustion engine as an auxiliary mechanism of the valve mechanism has been proposed in recent years.
A conventional device of this kind is disclosed, for example, in U.S. Pat. No. 4,858,572. This device includes a rotor which is fixed on the cam shaft, a drive member which is driven by the rotational torque from a crank shaft and rotatably mounted on the cam shaft so as to surround the rotor, a plurality of chambers which are defined between the drive member and the rotor, each of which has a pair of circumferentially opposed walls, a plurality of vanes which are mounted to the rotor and which extend outwardly therefrom in the radial direction into the chambers so as to divide each of chambers into a first pressure chamber and a second pressure chamber, and a pin which is accommodated in a hole of the drive member and able to insert into a hole of the rotor by a coil spring. In this device, a fluid under pressure is supplied to a selected one of the first pressure chamber and the second pressure chamber in response to the running condition of the internal combustion engine. An angular phase difference between the crank shaft and the cam shaft is controlled so as to advance or retard the valve timing relative to the crank shaft. The fluid under pressure is delivered from an oil pump. The valve timing control device is in the position of the maximum advanced condition, when each of the vanes contacts with one of the opposed walls of each of the chambers. On the other hand, the valve timing control device is in the position of the maximum retarded condition, when each of the vanes contacts with the other of the opposed walls of each of the chambers.
When the valve timing control device is in the position of the maximum retarded condition, the pin is inserted in the hole of the rotor by the coil spring. If the valve timing control device changes up the advanced condition from the portion of the maximum retarded condition, the pin is pulled out from the hole of the rotor by the fluid under pressure against the coil spring.
In the above mentioned prior art device, when the valve timing control device changes up the advanced condition from the portion of the maximum retarded condition, a part of the fluid under pressure supplied to the first and second pressure chambers which make the vanes rotate in order to advance the valve timing is also supplied to the chamber which makes the pin be pulled out from the hole against the coil spring. Accordingly, the fluid under pressure works at the chambers for rotating the vanes and at the same time the chamber for pulling out the pin. When the fluid pressure in the chambers for rotating the vanes is high enough to start rotating the vanes before the pin is pulled out from the hole completely, the rotor pushes the pin to the wall of the hole. The pin may stick in the hole and not come out from the hole. This causes the vanes not to be able to rotate.
SUMMARY OF THE INVENTION
Accordingly, it is an object of the present invention to provide an improved valve timing control device without the foregoing drawbacks.
In accordance with the present invention, a valve timing control device comprises, a rotor fixed on a cam shaft of an engine, a housing member rotatably mounted on the cam shaft so as to surround the rotor, a chamber defined between the housing member and the rotor and having a pair of circumferentially opposed walls, a vane mounted on the rotor and extended outwardly therefrom in the radial direction into the chamber so as to divide the chamber into a first pressure chamber and a second pressure chamber, a fluid supplying means for supplying fluid under pressure to at least a selected one of the first pressure chamber and the second pressure chamber, a locking means for connecting the housing member and the rotor, and a canceling means for canceling the locking means, before the fluid supplying means supplies fluid under pressure to the first pressure chamber or the second pressure chamber.
In accordance with the present invention, a canceling means cancels the locking member before the fluid supplying means supplies the fluid under pressure to rotate the vanes so that the pin is pulled out from the hole completely before the vanes rotate.
Other objects and advantages of invention will become apparent during the following discussion of the accompanying drawings.
BRIEF DESCRIPTION OF THE DRAWING FIGURES
The foregoing and additional features of the present invention will become more apparent from the following detailed description of preferred embodiments thereof when considered with reference to the attached drawings, in which:
FIG. 1 is a sectional view of the embodiment of a valve timing control device in accordance with the prevent invention;
FIG. 2 is a section taken along the line A--A in FIG. 1 in accordance with the present invention; and
FIG. 3 is a view similar to FIG. 2, showing various modifications.
DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS
A valve timing control device in accordance with preferred embodiment of the present invention will be described with reference to the attached drawings.
FIGS. 1 to 3 show an embodiment of the present invention. Referring to FIG. 1, a valve timing control device 10 of the embodiment includes an exhaust cam shaft 12, a rotor 22, a plurality of vanes 52 and a housing 18. The exhaust cam shaft 10 is rotatably mounted on a cylinder head 100 of an engine E. The exhaust cam shaft 12 has two circular groves 32, 34. Both the circular grooves 32, 34 are formed so as to maintain a predetermined distance between each other. The rotor 22 is fixed to the projecting end of the exhaust cam shaft 12 by a bolt 24. The rotor 22 has a plurality of grooves for inserting the vanes 52 as shown in FIGS. 2 and 3. One side end of the housing 18 is fixed to a timing pulley 14 and the other side end of the housing 18 is fixed to a side plate 20 by a bolt 16. Therefore, the housing 18, the timing pulley 14 and the side plate 20 act as a single body. Rotational torque is transmitted via a belt 102 (or a chain 102) from a crank shaft 104 which is rotated by the engine E. A pin 44 is able to connect between the rotor 22 and the housing 18 when the rotor 22 is in phase with the housing 18.
The exhaust cam shaft 12 has a plurality of cams (not shown). Each cam makes the exhaust valves open and close. There are two passages 28, 30 which are formed in the exhaust cam shaft 12 and extend in the axial direction. One end of the passage 28 communicates with the circular groove 32 through a passage 33. The circular groove 32 communicates with a passage 106 which is formed in the cylinder head 100 of an engine E. On the other hand, one end of the passage 30 communicates with the circular groove 34 through a passage 35. The circular groove 34 communicates with a passage 108 which is formed in the cylinder head 100 of an engine E. Both passages 106 and 108 communicate with a fluid supplying device. The fluid supplying device is comprised of a changeover valve 112, a fluid pump 114 and a controller 116. In this embodiment, the changeover valve 112 is a four port-three position type electromagnetic valve. The fluid pump 114 is driven by the engine E and discharges the fluid (e.g., oil) for lubricating the engine E. The pump 114 may be a pump for lubricating the engine E. The passage 108 is connected to a port A of the changeover valve 112 and the passage 106 is connected to a port B of the changeover valve 112. A port P of the changeover valve 112 communicates with a discharge portion of the fluid pump 114 via a passage 118 and a port R of the changeover valve 112 communicates with a reservoir 122 via a passage 120. The portion of the changeover valve 112 is controlled by the controller 116 so that a first condition as shown in FIG. 1 in which the discharged fluid from the pump 114 is supplied to the passage 108 and in which the passage 106 communicates with the reservoir 122, a second condition in which all the ports A, B, P, R are interrupted, a third condition in which the discharged fluid from the pump 114 is supplied to the passage 106 and in which the passage 108 communicates with the reservoir 122 are selectively obtained. The controller 116 controls the above conditions of the changeover valve 112 based on parameter signals such as engine speed, the opening level of a throttle valve (not shown) and so on.
In the rotor 22 and the housing 18, a valve timing control mechanism V is mounted therein. The rotor 22 has a cylindrical shape. As shown in FIGS. 2 and 3, the housing 18 has an inner bore 37 and is rotatably mounted on the outer circumferential surface of the rotor 22 so as to surround the rotor 22. The housing 18 has the same axial length as the rotor 22 and is provided with five grooves 38 which are outwardly extended from the inner bore 37 in the radial direction and which are separated in the circumferential direction at regular intervals. The housing 18 is also provided with a plurality of holes 36 for penetration by the bolt 16. The holes 36 penetrate in the axial direction and are separated in the circumferential direction at regular intervals.
There are five chambers which are made of the grooves 38. The chambers are separated in the circumferential direction at regular intervals, and each has a pair of circumferentially opposed walls 37a and 37b. Therefore, each chamber is defined along the rotor 22, the housing 18, the timing pulley 14 and the side plate 20. On the outer circumferential portion of the rotor 22, there are five grooves 23. The number of the grooves 23 is equal to the number of the chambers. Each of the grooves 23 extends inwardly therefrom in the radial direction and each is separated in the circumferential direction at regular intervals. Each of the vanes 52 that extend outwardly in a radial direction into each of the chambers is mounted in each of the grooves 23, respectively. Thereby, each of chambers is divided into a first pressure chamber 54, 56, 58, 60, 62 and a second pressure chamber 64, 66, 68, 70, 72, both of which are fluid tightly separated from each other.
The housing 18 has a hole 50 which extends inwardly thereof in the radial direction and which penetrates in the radial direction. The bottom end of the hole 50 has a small hole portion 42. The small hole portion 42 is able to accommodate a pin 44 which is pushed forward into the rotor 22 by a coil spring 40. The pin 44 has a large diameter portion 46 which is engaged in the hole 50. The coil spring 40 is supported in the hole 50 by a clip 48. On the other hand, the rotor 30 on the outer circumferential surface has a hole 98 which extends inwardly thereof in the radial direction so as to be insertable by the pin 44.
The rotor 22 is provided with five first passages 74, 76, 78, 80, 82, five second passages 84, 86, 88, 90, 92 and a passage 96. The first passages and the passage 96 are connected. One end of each of the first passages 74, 76, 78, 80, 82, communicates with the passage 28. The other end of the first passages 76, 78, 80 communicates with each of the first chambers 56, 58, 60. However, when the vanes 52 are in contact with the walls 37b as shown in FIG. 2, the other end of the first passage 74 and 82 is not able to communicate with the first chambers 54 and 62. The other end of the first passage 74 and 82 is able to communicate with the first chambers 54 and 62 if the vanes 52 are not in contact with the walls 37b. On the other hand, one end of each of the second passages 84, 86, 88, 90, 92 communicates with the passage 30 and the other end of the second passages 84, 86, 88, 90, 92 communicates with each of the second chambers 64, 66, 68, 70, 72.
The operation of the valve timing control device having the above structure will now be described.
The exhaust camshaft 12 is rotated clockwise by timing pulley 14. Thereby, exhaust valves (not shown) are opened and closed. The pressure of fluid delivered from the oil pump 114 is increased. Fluid under the resulting pressure is supplied to the changeover valve 112. At that time, the changeover valve 112 is in the first condition as shown in FIG. 1, and fluid is supplied to the second chambers 64, 66, 68, 70 and 72 via the passage 108, the passage 30 and second passages 84, 86, 88, 90 and 92. Thereby, the vanes 52 are rotated in the counterclockwise direction, together with the rotor 22 and the exhaust camshaft 12. Upon fitting of the pin 44 into the hole 98 of the rotor 22, such rotation is terminated. Thus, the exhaust cam shaft 20 is retarded through an angle relative to the crank shaft 104.
On the other hand, for returning the exhaust camshaft 12 from the retarded condition to the advanced condition, the vanes 52 are rotated in the clockwise direction. The changeover valve 112 is changed into the third portion and supplying fluid under pressure to the first passages 74, 76, 78, 80, 82 via the passage 106 and the passage 28. Since the first passages 74, 76, 78, 80, 82 communicate with the passage 96, fluid under pressure supplied into the hole 98 urges the pin 44 fully into the hole 50 of the housing 18. At the same time, fluid under pressure is supplied into the first chamber 56, 58 and 60 from the first passage 76, 78, 80. After the pin 44 is retracted into the hole 50 and the vanes 52 are little rotated in the clockwise direction, fluid under pressure is supplied into the first chamber 54 and 62 from the first passage 74 and 82. Therefore, releasing the connection between the rotor 22 and the housing 18 before pressure is increased in the first chambers 54, 56, 58, 60 and 62 so as to make the vanes 52 rotate in the clockwise direction as shown in FIG. 3. During the retarding rotary movement of the vanes 52, fluid in each second chambers 64, 66, 68, 70, 72 is drained to the reservoir 122 through the passage 30, the passage 108, second passages 84, 86, 88, 90, 92 and the changeover valve 112.
While the invention has been described in connection with one of its preferred embodiments, it should be understood that changes and modifications may be made without departing from the spirit and scope of the appended claims.
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A valve timing control device has a first pressure chamber and a second pressure chamber to rotate vanes mounted on a rotor and a fluid supplying means for supplying fluid under pressure to at least a selected one of the first pressure chamber and the second pressure chamber in order to control valve timing. The device further includes a locking means for connecting a housing member and the rotor and a canceling means for canceling the operation of the locking means. The canceling means cancels the locking means before the fluid supplying means supplies fluid under pressure to the first pressure chamber or the second pressure chamber, so that the locking means is canceled completely before the vanes rotate.
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BACKGROUND OF THE INVENTION
[0001] This invention relates generally to aircraft gas turbine engines, and more specifically to counter-rotating gas turbine engines.
[0002] At least one known gas turbine engine includes, in serial flow arrangement, a forward fan assembly, an aft fan assembly, a high-pressure compressor for compressing air flowing through the engine, a combustor for mixing fuel with the compressed air such that the mixture may be ignited, and a high-pressure turbine. The high-pressure compressor, combustor and high-pressure turbine are sometimes collectively referred to as the core engine. In operation, the core engine generates combustion gases which are discharged downstream to a counter-rotating low-pressure turbine that extracts energy therefrom for powering the forward and aft fan assemblies. Within at least some known gas turbine engines, at least one turbine rotates in an opposite direction than the other rotating components within the engine
[0003] At least one known counter-rotating low-pressure turbine has an inlet radius that is larger than a radius of the high-pressure turbine discharge. The increase inlet radius accommodates additional stages within the low-pressure turbine. Specifically, at least one known counter-rotating low-pressure turbine includes an outer rotor having a first quantity of low-pressure stages that are rotatably coupled to the forward fan assembly, and an inner rotor having an equal number of stages that is rotatably coupled to the aft fan assembly.
[0004] During engine assembly, such known gas turbine engines are assembled such that the outer rotor is cantilevered from the turbine rear-frame. More specifically, the first quantity of stages of the outer rotor are each coupled together and to the rotating casing, and the outer rotor is then coupled to the turbine rear-frame using only the last stage of the outer rotor, such that only the last stage of the outer rotor supports the combined weight of the outer rotor rotating casing. Accordingly, to provide the necessary structural strength to such engines, the last stage of the outer rotor is generally much larger and heavier than the other stages of the outer rotor. As such, during operation, the performance penalties associated with the increased weight and size may tend to negate the benefits of utilizing a counter-rotating low-pressure turbine.
BRIEF DESCRIPTION OF THE INVENTION
[0005] In one aspect, a method for assembling a gas turbine engine is provided. The method includes providing a low-pressure turbine inner rotor that includes a first plurality of turbine blade rows configured to rotate in a first direction, and rotatably coupling a low-pressure turbine outer rotor to the inner rotor, wherein the outer rotor includes a second plurality of turbine blade rows that are configured to rotate in a second direction that is opposite the first rotational direction of the inner rotor and such that at least one of the second plurality of turbine blade rows is coupled axially forward of the first plurality of turbine blade rows.
[0006] In another aspect, a counter-rotating rotor assembly is provided. The rotor assembly includes an inner rotor including a first plurality of rows of turbine blades configured to rotate in a first direction, and an outer rotor including a second plurality of rows of turbine blades configured to rotate in a second direction that is opposite the rotational direction of the inner rotor, the outer rotor coupled within the rotor assembly such that at least one of the second plurality of rows of turbine blades is coupled axially forward of the inner rotor first plurality of rows of turbine blades.
[0007] In a further aspect, a gas turbine engine is provided. The gas turbine engine includes an inner rotor including a first plurality of rows of turbine blades configured to rotate in a first direction, and an outer rotor including a second plurality of rows of turbine blades configured to rotate in a second direction that is opposite the rotational direction of the inner rotor, the outer rotor is coupled within the rotor assembly such that at least one of the second plurality of rows of turbine blades is coupled axially forward of the inner rotor first plurality of rows of turbine blades.
BRIEF DESCRIPTION OF THE DRAWINGS
[0008] FIG. 1 is a cross-sectional view of a portion of an exemplary gas turbine engine;
[0009] FIG. 2 is a schematic diagram of an exemplary counter-rotating low pressure turbine assembly that can be used with the gas turbine engine shown in FIG. 1 .
[0010] FIG. 3 is a schematic diagram of an exemplary counter-rotating low pressure turbine assembly that can be used with the gas turbine engine shown in FIG. 1 .
DETAILED DESCRIPTION OF THE INVENTION
[0011] FIG. 1 is a cross-sectional view of a portion of an exemplary gas turbine engine 10 that includes a forward fan assembly 12 and an aft fan assembly 14 disposed about a longitudinal centerline axis 16 . The terms “forward fan” and “aft fan” are used herein to indicate that one of the fans 12 is coupled axially upstream from the other fan 14 . In one embodiment, fan assemblies 12 and 14 are positioned at a forward end of gas turbine engine 10 as illustrated. In an alternative embodiment, fan assemblies 12 and 14 are positioned at an aft end of gas turbine engine 10 . Fan assemblies 12 and 14 each include a plurality of rows of fan blades 19 positioned within a nacelle 18 . Blades 19 are joined to respective rotor disks 21 that are rotatably coupled through a respective fan shaft 20 to forward fan assembly 12 and through a fan shaft 22 to aft fan assembly 14 .
[0012] Gas turbine engine 10 also includes a core engine 24 that is downstream from fan assemblies 12 and 14 . Core engine 24 includes a high-pressure compressor (HPC) 26 , a combustor 28 , and a high-pressure turbine (HPT) 30 that is coupled to HPC 26 via a core rotor or shaft 32 . In operation, core engine 24 generates combustion gases that are channeled downstream to a counter-rotating low-pressure turbine 34 which extracts energy from the gases for powering fan assemblies 12 and 14 through their respective fan shafts 20 and 22 .
[0013] FIG. 2 is a schematic diagram of a straddle-mounted counter-rotating low-pressure turbine assembly 100 that may be used with a gas turbine engine similar to gas turbine engine 10 (shown in FIG. 1 ). In the exemplary embodiment, low-pressure turbine 100 includes stationary outer casing 36 that is coupled to core engine 24 downstream from high-pressure turbine 30 (shown in FIG. 1 ). Low-pressure turbine 100 includes a radially outer rotor 110 that is positioned radially inwardly of outer casing 36 . Outer rotor 110 has a generally frusto-conical shape and includes a plurality of circumferentially-spaced rotor blades 112 that extend radially inwardly. Blades 112 are arranged in axially-spaced blade rows or stages 114 . Although, the exemplary embodiment illustrates four stages 114 , it should be realized that outer rotor 110 may have any quantity of stages 114 without affecting the scope of the method and apparatus described herein. More specifically, outer rotor 110 includes M stages 114 of blades 112 .
[0014] Low-pressure turbine 100 also includes a radially inner rotor 120 that is aligned substantially coaxially with respect to, and radially inward of, outer rotor 110 . Inner rotor 120 includes a plurality of circumferentially-spaced rotor blades 122 that extend radially outwardly and are arranged in axially-spaced rows or stages 124 . Although, the exemplary embodiment illustrates three stages, it should be realized that inner rotor 120 may have any quantity of stages without affecting the scope of the method and apparatus described herein. More specifically, inner rotor 120 includes N stages 124 of blades 122 . In the exemplary embodiment, M=N+1. Accordingly, and in the exemplary embodiment, outer rotor 110 includes an even number of stages 114 and inner rotor 120 includes an odd number of stages 124 such that outer rotor 110 surrounds and/or straddles inner rotor 120 .
[0015] In the exemplary embodiment, inner rotor blades 122 extending from stages 124 are axially-interdigitated with outer rotor blades 112 extending from stages 114 such that inner rotor stages 124 extend between respective outer rotor stages 114 . Rotor blades 112 and 122 are therefore configured for counter-rotation of the rotors 110 and 120 .
[0016] In the exemplary embodiment, low-pressure turbine 100 also includes a rotor support assembly 130 that includes a stationary annular turbine rear-frame 132 that is aft of low-pressure turbine outer and inner blades 112 and 122 . A rotatable aft frame 134 is positioned aft of outer and inner blades 112 and 122 and upstream from turbine rear-frame 132 . Aft frame 134 is coupled to an aft end of outer rotor 110 for rotation therewith and to facilitate providing additional rigidity for supporting blades 112 . An annular turbine mid-frame 140 is upstream from outer and inner blades 112 and 122 .
[0017] Low-pressure turbine 100 also includes a first shaft 150 that is coupled between a forward end 152 of outer rotor 110 and a first shaft bearing 154 that is rotatably coupled to turbine mid-frame 140 via a structural member 156 . Specifically, first shaft 150 extends between forward end 152 and first shaft bearing 154 such that the weight of outer rotor 110 is distributed approximately equally about the circumference of gas turbine engine 10 at forward end 152 , via structural member 156 .
[0018] A second shaft 160 extends between inner rotor 120 and fan 14 such that inner rotor 120 is rotatably coupled to fan 14 . In the exemplary embodiment, second shaft 160 is positioned radially inward of first shaft 150 . A second shaft bearing 162 is coupled to second shaft 160 such that the weight of inner rotor 120 is distributed approximately equally about the circumference of gas turbine engine 10 at forward end 152 , via a structural member 164 .
[0019] Low-pressure turbine 100 also includes a third shaft 170 that rotatably couples fan 12 , outer rotor 110 , and turbine rear-frame 132 together. More specifically, low-pressure turbine 100 includes a third shaft differential bearing 172 coupled between second shaft 160 and third shaft 170 , and a third bearing 174 coupled between third shaft 170 and turbine rear-frame 132 . Specifically, third shaft 170 extends between fan 12 and turbine rear-frame 132 such that the weight of outer rotor 110 at an aft end 176 is distributed approximately equally about the circumference of gas turbine engine 10 at aft end 176 , via bearing 174 and turbine rear-frame 132 . In one embodiment, at least one of first bearing 154 , second bearing 162 , third differential bearing 172 , and third bearing 174 is a foil bearing. In another embodiment, at least one of first bearing 154 , second bearing 162 , third differential bearing 172 , and third bearing 174 is at least one of a roller bearing or a ball bearing.
[0020] In the exemplary embodiment, during engine operation, a radial force generated during rotation of outer rotor 110 is transmitted to bearings 154 and 174 . Specifically, as low-pressure turbine 100 rotates, bearings 154 and 174 contact turbine mid-frame 140 and turbine rear-frame 132 respectively to facilitate reducing radial movement of outer rotor 110 . Since each respective bearing 154 and 174 is coupled to outer casing 36 through turbine mid-frame 140 and turbine rear-frame 132 , outer rotor 110 is maintained in a relatively constant radial position with respect to outer casing 36 . More specifically, utilizing straddle-mounted low-pressure turbine 100 that includes an odd number of turbine stages 114 and 124 collectively, that are supported at both ends by bearings 154 and 174 respectively, facilitates eliminating the at least one known differential bearing that is coupled between the concentric low-pressure shafts when an even number of total stages are used in at least one known counter-rotating low-pressure turbine. Moreover, utilizing straddle-mounted low-pressure turbine 100 facilitates reducing the weight of gas turbine engine 10 by eliminating a large over-turning moment generated by a known low-pressure turbine.
[0021] FIG. 3 is a schematic diagram of a straddle-mounted counter-rotating low-pressure turbine assembly 200 that may be used with a gas turbine engine similar to gas turbine engine 10 (shown in FIG. 1 ). In the exemplary embodiment, low-pressure turbine 200 includes stationary outer casing 36 that is coupled to core engine 24 downstream from high-pressure turbine 30 (shown in FIG. 1 ). Low-pressure turbine assembly 200 includes radially outer rotor 110 that is positioned radially inwardly of outer casing 36 . Outer rotor 110 has a generally frusto-conical shape and includes plurality of circumferentially-spaced rotor blades 112 that extend radially inwardly. Blades 112 are arranged in axially-spaced blade rows or stages 114 . Although, the exemplary embodiment illustrates four stages 114 , it should be realized that outer rotor 110 may have any quantity of stages 114 without affecting the scope of the method and apparatus described herein. More specifically, outer rotor 110 includes M stages 114 of blades 112 .
[0022] Low-pressure turbine 200 also includes radially inner rotor 120 that is aligned substantially coaxially with respect to, and radially inward of, outer rotor 110 . Inner rotor 120 includes plurality of circumferentially-spaced rotor blades 122 that extend radially outwardly and are arranged in axially-spaced rows or stages 124 . Although, the exemplary embodiment illustrates three stages, it should be realized that inner rotor 120 may have any quantity of stages without affecting the scope of the method and apparatus described herein. More specifically, inner rotor 120 includes N stages 124 of blades 122 . In the exemplary embodiment, M=N+1. Accordingly, and in the exemplary embodiment, outer rotor 110 includes an even number of stages 114 and inner rotor 120 includes an odd number of stages 124 such that outer rotor 110 surrounds and/or straddles inner rotor 120 .
[0023] In the exemplary embodiment, inner rotor blades 122 extending from stages 124 are axially-interdigitated with outer rotor blades 112 extending from stages 114 such that inner rotor stages 124 extend between respective outer rotor stages 114 . The blades 112 and 122 are therefore configured for counter-rotation of the rotors 110 and 120 .
[0024] In the exemplary embodiment, low-pressure turbine 200 also includes rotor support assembly 130 that includes stationary annular turbine rear-frame 132 that is aft of low-pressure turbine outer and inner blades 112 and 122 . Rotatable aft frame 134 is positioned aft of outer and inner blades 112 and 122 and upstream from turbine rear-frame 132 . Frame 134 is coupled to an aft end of outer rotor 110 for rotation therewith and to facilitate providing additional rigidity for supporting blades 112 . Annular turbine mid-frame 140 is upstream from outer and inner blades 112 and 122 .
[0025] Low-pressure turbine 200 also includes a first shaft 250 that is coupled between forward end 152 of outer rotor 110 and fan 14 . More specifically, first shaft 250 is rotatably coupled to turbine mid-frame 140 via a structural member 252 and a first shaft bearing 254 . First shaft 250 extends between outer rotor 110 and fan 14 such that fan 14 is rotationally coupled to outer rotor 110 and such that the weight of outer rotor 110 is distributed approximately equally about the circumference of gas turbine engine 10 at forward end 152 , via structural member 252 .
[0026] A second shaft 260 extends between inner rotor 120 and fan 12 such that inner rotor 120 is rotatably coupled to fan 12 . In the exemplary embodiment, second shaft 260 is positioned radially inward of first shaft 250 . A shaft bearing 262 is coupled to second shaft 260 such that the weight of inner rotor 120 is distributed approximately equally about the circumference of gas turbine engine 10 at forward end 152 , via a structural member 252 . A shaft bearing 264 is coupled to second shaft 260 such that the weight of inner rotor 120 is distributed approximately equally about the circumference of gas turbine engine 10 at aft end 176 , via a structural member 266 . More specifically, second shaft 260 is supported at forward end 152 by turbine mid-frame 140 and supported at aft end 176 by turbine rear-frame 132 .
[0027] Low-pressure turbine 200 also includes a third shaft 270 that rotatably couples outer rotor 110 to turbine rear-frame 132 . More specifically, third shaft 270 extends outer rotor aft end 176 to turbine rear-frame 132 such that the weight of outer rotor 110 at an aft end 176 is distributed approximately equally about the circumference of gas turbine engine 10 at aft end 176 , via bearing 264 and turbine rear-frame 132 . In one embodiment, at least one of bearings 254 , 262 , and/or 264 is a differential foil bearing. In another embodiment, at least one of bearings 254 , 262 , and/or 264 is at least one of a differential roller bearing or a differential ball bearing.
[0028] In the exemplary embodiment, during engine operation, a radial force generated during rotation of outer rotor 110 is transmitted to bearings 254 and 264 . Specifically, as low-pressure turbine 200 rotates, bearings 254 and 264 contact turbine mid-frame 140 and turbine rear-frame 132 respectively to facilitate reducing radial movement of outer rotor 110 . Since each respective bearing 254 and 264 is coupled to outer casing 36 through turbine mid-frame 140 and turbine rear-frame 132 , outer rotor 110 is maintained in a relatively constant radial position with respect to outer casing 36 . More specifically, utilizing straddle-mounted low-pressure turbine 200 that includes an odd number of turbine stages 114 and 124 collectively, that are supported at both ends by bearings 254 and 264 respectively, facilitates eliminating the at least one known differential bearing that is coupled between the concentric low-pressure shafts when an even number of total stages are used in at least one known counter-rotating low-pressure turbine. Moreover, utilizing straddle-mounted low-pressure turbine 200 facilitates reducing the weight of gas turbine engine 10 by eliminating a large over turning moment generated by a known low-pressure turbine that includes an outer rotor having an even number of stages.
[0029] The exemplary embodiments described above illustrate a counter-rotating low-pressure turbine having an outer rotor that includes an even number of stages and an inner rotor that includes an odd number of stages such that the outer rotor straddles the inner rotor. Since, the outer rotor straddles the inner rotor, the outer rotor is configurable to couple to either the forward or aft fan assembly. Utilizing a straddle-mounted counter-rotating low-pressure turbine facilitates reducing the weight of the gas turbine engine by eliminating the large over turning moment of a conventional low-pressure turbine that includes an outer rotor having an even number of stages. Moreover, the straddle-mounted turbines described herein facilitate handling a blade out event in which a large turbine unbalance may result in the outer rotating casing while also improving gas turbine engine performance by providing increased tip clearance control between the outer rotor and the casing. Moreover, the straddle-mounted turbines described herein facilitate reducing the weight of the turbine rear-frame by distributing the weight of the outer rotor between the turbine mid-frame and turbine rear-frame.
[0030] Exemplary embodiments of straddle-mounted counter-rotating low-pressure turbines are described above in detail. The components are not limited to the specific embodiments described herein, but rather, components of each system may be utilized independently and separately from other components described herein. Straddle-mounted turbines can also be used in combination with other known gas turbine engines.
[0031] While the invention has been described in terms of various specific embodiments, those skilled in the art will recognize that the invention can be practiced with modification within the spirit and scope of the claims.
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A method for assembling a gas turbine engine that includes providing a low-pressure turbine inner rotor that includes a first plurality of turbine blade rows configured to rotate in a first direction, and rotatably coupling a low-pressure turbine outer rotor to the inner rotor, wherein the outer rotor includes a second plurality of turbine blade rows that are configured to rotate in a second direction that is opposite the first rotational direction of the inner rotor and such that at least one of the second plurality of turbine blade rows is coupled axially forward of the first plurality of turbine blade rows.
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BACKGROUND OF THE INVENTION
1. Field of the Invention
The present invention relates to a method for picture data reduction for digital video signals comprising a preprocessing of the signals by means of block-by-block transformation whereby a transformed and quantatized signal which was generated at a time t-1 and deposited in an image storage is subtracted from a transformed signal which occurs at a time t and whereby the difference signal obtained in such manner is subjected to a quantization.
2. Description of the Prior Art
Prior art methods for picture data reduction can be subdivided into:
1. DPCM (Differential Pulse Code Modulation) methods-transformation methods; and
2. Hybrid methods.
In DPCM methods, the difference between an estimate determined from samples that have already been transmitted and the actual sample is respectively identified. In pure DPCM coders, this prediction occurs three-dimensionally, in other words, both within a frame or picture as well as from frame to frame.
In transformation methods, an imaging of the frame into the transformation region occurs. Due to the high cost, only two dimensional transformations have previously been realized in practice.
The present invention relates to a hybrid method. The principles of a hybrid method is illustrated in FIG. 1. In FIG. 1, a digitized signal x (k, e, t) is supplied to a transformation stage and produces a transformation coefficient signal y(u, v, t) which is supplied to a quantitizer Q which produces a signal Ya(u, v, t) which is supplied through an adder to a coder C which produces a signal Yc(u,v,t) which is supplied as the channel signal. The output of the quantitizer Q is also supplied to a predictor and memory P+M which supplies a signal y p (u, v,t-1) to an adder to add the signal to the output of the transformation stage before supplying it to the quantitizer Q.
Hybrid coding represents a mixture of transformation and DPCM. The transformation within a frame occurs two-dimensionally, block size 16×16 or 8×8 picture points, whereas DPCM operates from frame to frame. The signal decorrelated by transformation and/or DPCM is quantitized and transmitted.
Basically, all hybrid methods operate according to the diagram illustrated in FIG. 1. In developed methods, the functions Q, P and C are adaptively executed
European Patent Application No. 82.3070263 discloses a method which employs a coder having the following essential features:
Dynamic bit allocation--The bit rate is minimized and is selected from a plurality of Huffman code tables by means of a prediction algorithm for each coefficient to be coded.
Length of run coding--Zeros successively appearing along a defined scan direction are coded by lengths of run.
Constant Channel rate--Is achieved by coupling the quantitizer to the buffer filling. A PI controller with proportional integrating behavior is employed for this purpose.
The publication of F. May, "Codierung von Bildfolgen mit geringer Rate fur gestorte Uebertrangungskanale", NTG-Fachberichte, Vol. 74, pp. 379-388, describes a system for picture transmission using narrow-band radio channels with a transmission rate of 9.6K bit/s and a frame frequency of 0.5 frames. A plurality of bit allocation matrices are provided for this known method so that the optimum of the respective block is identified and transmitted in the form of a class affiliation. Optimum non-linear quantization characteristics are also employed with respect to the quadratic error. A constant channel rate is achieved by input buffer control, in other words, every frame is first analyzed, the number of coeficients to be transmitted is then modified until the channel rate is observed.
The publication of W. H. Chen, W. K. Pratt entitled "Scene Adaptive Coder", in the IEEE Trans. Comm., Vol. Com32, No. 3, of Mar. 1984, describes an adaptive band width compression technique which employs a discrete cosine transformation. This system is similar to that describes in European Patent Application No. 82.30 70 263 referenced above.
A publication of A. G. Tescher, entitled "Rate Adaptive Communication", appearing in the IEEE International Conference on Communication, of 1978, pages 1.1-19.1.6 describes a concept for a bit rate control in a source coding system.
The technical book publication of W. K. Pratt entitled Image Transformation Techniques, published by the Academic Press, New York, San Francisco, and London in 1979 provides overall discussion of the transformation techniques of the systems.
SUMMARY OF THE INVENTION
The object of the present invention is to provide a method of the species initially referenced which enables a picture quality which is improved significantly over known methods for the same or constant channel rate. In the invention, picture data reduction for digital video signals comprises preprocessing the signals using block-by-block transformation method whereby a transformed and quantitized signal that was generated at a time t-1 and placed in an image storer is subtracted from a transformed signal that occurs at a time t and whereby the difference acquired in this manner is subjected to a quantitization and the quantitized difference signal is subjected to an analysis and is subjected to a time delay VZ which corresponds to the time requirement for the analysis AS and on the one hand updating the content of the image storage and the signal which is delayed in this manner is added to the signal read out from the image storer M which is also correspondingly delayed and is added thereto dependent on the addition condition signal acquired from the analysis and on the other hand is subjected to an entropy coding HC depending on the analysis results. The addition condition signals containing information as to whether a block whose analysis has been concluded is a "moved" or a "unmoved" block and in case said block is a "moved" block containing information regarding a coefficient group to be transmitted, the coded signal is subjected to a buffering B which is intended to offer an output signal channel a uniform data flow for transmission and offering said uniform data flow from a nonuniform data flow of the entropy coding. Dependent on the degree of buffer filling, a quantization stage Q, an analysis stage AS is influenced so that a signal from a buffer control means BC is supplied to the quantization stage Q for selecting one of a plurality of predetermined quantization characteristics whereby a second signal is supplied from the buffer control means BC to the analysis stage AS for the purpose of selecting the maximum number of coefficient groups and where a third signal is supplied to the analysis stage AS from the buffer control means BC for deciding whether a block is to be transmitted or is not to be transmitted. The coefficients represent the digitized video signal transformed block-by-block which is subdivided into coefficient groups according to prescribed rules and a measurement scale for each of these coefficient groups is identified in a calculation stage E such that the scale first causes a supergroup to be formed in a decision means S from neighboring coefficient groups and to be transmitted and selected such that the coefficient groups which are not to be transmitted according to the identified scale can be embedded in a supergroup and by means of which a classification is executed by a following step-by-step summation of all the scales respectively belonging to a block in an integrator I where i=2 . . . 3is preferably applies and E(i) is the scale for the coefficient group i and whereby E I (1)=E (1) applies and the classification serves the purpose for deciding whether a block is to be transmitted and what way a block to be transmitted is to be coded.
Other objects, features and advantages of the invention will be readily apparent from the following description of certain preferred embodiments thereof taken in conjunction with the accompanying drawings although variations and modifications may be effected without departing from the spirit and scope of the novel concepts of the disclosure and in which:
BRIEF DESCRIPTION OF THE DRAWINGS
FIG. 1 is a schematic illustration illustrating the basic concept of prior art hybrid coding;
FIG. 2 is a block diagram of a complete transmission system according to a preferred exemplary embodiment according to the invention;
FIG. 3 is a block diagram of a transmitter of the exemplary embodiment of the transmission system shown in FIG. 2;
FIG. 4 is a block circuit diagram of a receiver according to the exemplary embodiment shown in FIG. 2;
FIG. 5a is a schematic illustration of a preferred exemplary embodiment of the manner in which a field comprising mxn coefficients is subdivided into coefficient groups in the form of imaginary diagonal strips;
FIG. 5b is a schematic illustration which shows how a buffer control in the method of the invention effects the coder output rate by limiting the number of coefficient groups to be transmitted;
FIGS. 5c and 5d show how neighboring coefficient groups are combined in a supergroup; and
FIGS. 6a, 6b and 6c illustrate the characteristics of a buffer control.
DESCRIPTION OF THE PREFERRED EMBODIMENTS
As shown in FIG. 2, a transmitter has a transformation stage T which transforms the signal with a discrete cosine transformation (DCT). The invention can be utilized with other transformations as well. The coding method occurs as shown in the block circuit diagrams of FIGS. 2 and 3 for the transmitter and FIGS. 2 and 4 for the receiver. As shown in FIG. 2, the transmitter has a transformation stage T which transforms the sign and supplies it to a subtractor which supplies an output to a quantizer Q. The quantizer supplies an input to an adder which supplies an output to a memory M which also supplies an input to the adder and the memory M also supplies an input to the subtractor. A coding device HC receives the output of the quantizer and also an output of an analysis stage AS which receives an input from the quantizer Q. The coding device supplies an output to the output buffer B which supplies an output to the channel encoding device. The output buffer also supplies an input to the buffer control means BC which supplies inputs to the quantizer Q and to the analysis stage AS.
The output of the channel encoding means of the transmitter is supplied to the receiver wherein a channel decoding means receives the incoming signal and supplies it to a receiver buffer B E which supplies an output to a decoder DC which supplies an output to a reconstruction means R. A receiver buffer control means BC E receives an output from the receiver buffer B E and supplies an input to the reconstructions means R. A receiver summing means + E receives the output of the reconstruction means and also an input from the decoder DC. The receiver summing means supplies an output to the innertransformation stage IT which produces the reconstructed signal. The receiver summing means + E also supplies an input to a receiver image storer M E which supplies an input to the receiver summing element.
FIG. 3 illustrates in greater detail portions of the transmitter where the output of the transformation stage T is supplied to the subtractor which supplies an output to the quantizer Q which supplies an output to the first time delay VZ which supplies an output to the entropy coding device HC. An adder also receives output from the first time delay VZ as well as an output of a decision means S and an output of a classification device K. The adder supplies an output to a memory M which supplies an output to the subtractor. A second time delay VZ receives the output of the memory and supplies an input to the adder. The analysis stage AS comprises a calculation stage E which receives the output of the quantizer Q and supplies an input to a first network L1 and a second network L2. A decision means S receives the output of the first network L1 as well as an input N DMAX from the buffer control BC. An integrator I receives the output of the second network L2 and supplies an input to the classification stage K which receives an input T from the buffer control BC as well as an input N DMAX from the buffer control BC. The buffer control also supplies an input ≠ to the quantizer Q as illustrated. The entropy coding device HC supplies an output to the output buffer B which produces the output channel signal which is to be transmitted and also supplies an input to the buffer control BC.
The receiver buffer BE receives the incoming channel signal and supplies it to a decoder DC which supplies an output to the reconstruction means R. A receiver buffer control means BC E receives an output from the receiver buffer B E and supplies an input to the reconstruction means R. The decoder DC supplies an input to a receiver summing means + E which also receives the output of reconstruction means R. The transformed signal appears at the output of the receiver summing means + E and the output of the receiver summing means + E is supplied to a receiver image storer M E which also supplies an input to the receiver summing means +E.
The incoming frames are two-dimensionally cosine transformed in blocks (block size 16×16 picture points). The block size 8×8 can be simply realized by modification of Huffman code tables 1B and of the bit allocation matrices, Table 2 attached. The difference between the spectral coefficients thus obtained and the corresponding coefficients in the DPCM memory M is then quantized in block Q according to the quantization interval Δ determined by the buffer control.
The energy calculation stage E is then defined for each coefficient group as illustrated in FIG. 5A from the quanzation prediction error signal Δy Q (u, v, t). ##EQU1##
It is assured by the limit function f A (x) that the result t of ΔY Q 2 is not represented with more bits than needed for further processing. The accumulator employed for the summation likewise has only twelve bits whereby a thirteenth bit is set to "1" and remains as soon as overflow has once occured.
The energies E(i) obtained in this manner are forwarded to the decision means S through a network L1. L1 limits the amplitude range to E*(i)·(0≦E*(i)≦16) so that E*(i) can be represented with 5 bits.
Whether a coefficient group is to be transmitted is determined in the stage S for every coefficient group on the basis of its energy by comparison to thresholds deposited in table form. The number of the first coefficient group to be transmitted supplies N O whereas the number of the last coefficient group to be transmitted supplies N D . When N O <4 then it is equated with "1". In case no coefficient group to be transmitted has been found, N O and N D are equated with "1". It is therefore assured that the block is classified as unmoved given the classification K as well. The buffer control can influence the rate by assigning the maximum plurality of coefficient groups.
In case that N D is greater than a value N DMAX prescribed by the buffer control, then ND=N DMAX is to be set.
The output of the decision means S is forwarded for classification K to the classification means K and to a coding means HC and to a conditioned adder (+).
The output of the calculation stage E supplies the energies E(i) to an integrator I through a network L2 which cuts off or truncates the least four significant bits. The integrator forms the signal EI(i) from E(i) according to the following equation.
E I (i)=E I (i-1)+E(i) i=2 2, . . . , 31 and E I (1)=E(1) (2 )
Only the bits having the significance of 0 . . . 7 are thereby taken into consideration in the addition, whereas bit 8, OR-operated with the overflow bit of the adder, yields the bit 8 of the accumulator, so that 9-bit code words are again present at the output of the integrator I.
The classification stage K executes the following operations:
E.sub.I (N.sub.D)>T (barrier T=0,1,2,3 prescribed by the buffer control) → block moved
E.sub.I (N.sub.D)≦T→block unmoved (3)
By cutting off or truncating the four least-significant bits in the energy calculation, the four values of the barrier or threshold T specified in the relationship of equation (3) result from FIG. 6a as shown by curve K1.
When the block is unmoved, it is assigned to the "unmoved" class 4. When the block is moved and thus, is to be transmitted, then the energy of the supergroup to be transmitted is defined as: ##EQU2## and with the assistance of E G , the block is assigned to one of three "moved" classes.
The two necessary class boundaries G(N O , N D , 1) and G(N O , N D , 2) are identified in the following fashion: ##EQU3## where E H is the mean energy variance presumed in the generation of the Huffman code tables B(i, j, k) is the allocation matrix f of the Huffman code tables for class K (table 2),
E Hg is the energy up to the diagonal N D averaged over class k and k+1. ##EQU4##
The case discrimination and the calculation of G(N O , N D ,k) and E G results that the like component in all classes is coded with the same Huffman code table for maximum variance. Its energy therefore remains unconsidered in the classification. The supergroup to be transmitted is then coded in the entropy coding means HC and written into the output buffer B. The code tables 1-7 of table 1 are employed therefore and these being selected for every coefficient via the allocation matrices in table 2. So-called "modified" Huffman codes are employed in the coding. Values /y/≦y esc are thereby Huffman-coded. Given /y/>y esc , an escape word is transmitted followed by the value of y in the natural code. The quantization interval can assume the values Δ o , Δ o /2,Δ o /4,Δ o /8. Amplitude levels of 255, 511, 1023 and 2047 correspond to these values. These natural code words therefore have different lengths (8, 9, 10, 11 bits).
The class affiliation and the supergroup (N O , N D ) must be additionally transmitted for every block. The following bit rates are required for this overhead:
First case: 2 bits when k=4 ("unmoved" class)
Second case: 2 bits + the average word length indicated in table 1B ("Huffman" code tables for supergroup and class when k=1 through 3.
Last, the DPCM memory is brought to the current reading. The supergroup and the class affiliation are therefore to be considered as: ##EQU5## Y'(u,v,t)=Y'(u,v,t-1)+Δy Q (u,v t) otherwise.
(Buffer Control)
As set forth above, a constant channel rate is achieved by modification of the barrier "moved"/"unmoved" T, of the quantization interval Δ and of the diagonal N DMAX to be maximally transmitted. The values T, Δ, N DMAX illustrated in FIG. 6b are identified by the non-linear characteristics K1 through K3 depending on the filling of the buffer.
In the region B n <B(k)≦1 (characteristic K3), the rate is controlled via N DMAX .
No control results for BΔ≦B(k)≦1. When 0≦B(k)<BΔ occurs, then the buffer control results via the quantization interval Δ shown in FIG. 6c. Δ can thereby only assume values that meet the following inequality.
0≦int (1dΔo/Δ))≦3 (8)
As previously set forth, the quantization interval must also be considered in the coding.
Assuming a very full buffer B(k)>B T illustrated by the characteristic K1 in FIG. 6a, the barrier T is also raised by a quadratic characteristic K1. The raising of the barrier "moved"/"unmoved" then occurs in two ways:
(a) increase of T by the characteristic K1
(b) reduction of N DMAX and, thus, of the total energy (E G ) by characteristic K3.
A very efficient noise suppression with full buffer is achieved by means of (b).
Significant innovations over known methods of the present invention are:
(1) Buffer Control
Way of limiting the bit rate by omitting coefficient groups when the buffer runs full. The number of coefficient groups is therefore controlled with a proportional controller.
Control of the rate by way of the quantization interval given a buffer running empty with a proportional controller. The quantization interval can therefore only assume the values of Δ o , Δ o /2,Δ o /4,Δ o /8.
Way of recognizing altered blocks by calculation of the energy of the quantitized signal. This is identical to a coupling of the "moved"/"unmoved" T to the quantization interval. A good value for T is T=N 2 /12. This T is constant over a wide range of the buffer filling.
Raising the barrier T given buffer running full by way of a quadratic characteristic.
The controller for the number of diagonals to be maximally transmitted and the controller for the quantization interval never work in common but only respectively one operates dependent on the fill of the buffer.
The fact that only the coefficient groups that are transmitted are taken into consideration for the modification recognition for blocks is an advantage.
2. Coding
Adaptive Huffman coding by fixed allocation of the Huffman code tables for three "moved" categories (previously there has been dynamic allocation of the Huffman code tables (HCT) /1/ and fixed allocation of non-linear optimum n-bit maxquantizers /2/).
Classification on the basis of the quantized signal.
Way of identifying the class boundaries from the allocation of the Huffman code tables and the variance for which the HCT are generated.
Way of recognizing and coding modified supergroups within a block (in /1/, by length of run coding and end of block code word).
The fact that only the coefficient groups that are transmitted are considered for the modified recognition of blocks.
The tables which are utilized in this invention follow.
TABLE 1______________________________________Huffman Code Table______________________________________(A) For CoefficientsGiven code word numbers unequal to zero and Huffman codeof the Operation sign is appended to the tables:(1) Less Than Zero VZ = 1(2) Greater Than Zero VZ = 0(The code word length in the corresponding code words istherefore greater than the length of the code in the table.)Code Table Number: 1Number of words: 511Scanner: 0.75Residual Probability 0.00100Actual Residual Probility 0.00021Mean Word Length: 1.8520Entropy: 1.6386______________________________________Code Word Number Huffman Code Word Length Probability______________________________________0 0 1 0.6097491 10 3 0.1654092 110 4 0.0251913 1110 5 0.0038374 11110 6 0.0005845 Escape Word 11111 14 0.0000896 ESC 14 0.0000147 ESC 14 0.0000028 ESC 14 0.0000009 ESC 14 0.00000010 ESC 14 0.000000and so forth until NW/2 = 255______________________________________Code Table Number 2Number of words 511Scanner 1.50Residual Probability 0.00100Actual Residual Probability 0.00086Mean Word Length 2.6491Entropy 2.5680______________________________________Code Word Number Huffman Code Word length Probability______________________________________0 00 2 0.3752991 1 2 0.1904552 010 4 0.0743253 0110 5 0.0290064 01110 6 0.0113195 011110 7 0.0044176 0111110 8 0.0017247 01111110 9 0.0006738 Escape Word 01111111 17 0.0002639 ESC 17 0.00010210 ESC 17 0.00004011 ESC 17 0.00001612 ESC 17 0.00000613 ESC 17 0.000002and so forth until NW/2 = 255______________________________________Code Table Number: 3Number of Words: 511Scanner: 3.00Residual Probability 0.00100Actual Residual Probability 0.00068Entropy 3.5416______________________________________Code Word Number Huffman Code Word Length Probability______________________________________0 00 2 0.2096201 10 3 0.1483142 110 4 0.0926523 010 4 0.0578804 1110 5 0.0361585 0110 5 0.0225886 11110 6 0.0141117 01110 6 0.0088158 111110 7 0.0055079 011110 7 0.00344010 1111110 8 0.00214911 0111110 8 0.00134212 11111110 9 0.00083913 01111110 9 0.00052414 111111110 10 0.00032715 111111111 10 0.00020416 Escape Word 01111111 17 0.00012817 ESC 17 0.00008018 ESC 17 0.00005019 ESC 17 0.00003120 ESC 17 0.00001921 ESC 17 0.000012and so forth until NW/2 = 255______________________________________Code Table Number: 4Number of Words: 511Scanner: 6.00Residual Probability 0.00800Actual Residual Probability 0.00636Mean Word Length 4.5988Entropy: 4,5335______________________________________0 000 3 0.1109671 01 3 0.0931792 100 4 0.0736473 110 4 0.0582094 1010 5 0.0460075 1110 5 0.0363636 0010 5 0.0287417 10110 6 0.0227168 11110 6 0.0179549 00110 6 0.01419110 101110 7 0.01121611 111110 7 0.00886512 001110 7 0.00700713 1011110 8 0.00553814 1111110 8 0.00437715 0011110 8 0.00346016 10111110 9 0.00273417 11111110 9 0.00216118 101111110 10 0.00170819 101111111 10 0.00135020 111111110 10 0.00106721 111111111 10 0.00084322 Escape Word 0011111 16 0.00066723 ESC 16 0.00052724 ESC 16 0.00041625 ESC 16 0.00032926 ESC 16 0.00026027 ESC 16 0.000206and so forth until NW/2 = 255______________________________________Code Table Number: 5Number of Words: 511Scanner: 12.00Residual Probability 0.00800Actual Residual Probability 0.00759Mean Word Length 5.5889Entropy 5.5313______________________________________0 0000 4 0.0571141 001 4 0.0523142 010 4 0.0465093 1000 5 0.0413484 1010 5 0.0367605 1100 5 0.0326816 1110 5 0.0290547 0110 5 0.0258308 10010 6 0.0229649 10110 6 0.02041610 11010 6 0.01815011 11110 6 0.01613612 00010 6 0.01434613 01110 6 0.01275414 100110 7 0.01133915 101110 7 0.01008016 110110 7 0.00896217 111110 7 0.00796718 000110 7 0.00708319 011110 7 0.00629720 1001110 8 0.00559821 1011110 8 0.00497722 1101110 8 0.00442523 1111110 8 0.00393424 0001110 8 0.00349725 0111110 8 0.00310926 10011110 9 0.00276427 10111110 9 0.00245728 11011110 9 0.00218529 00011110 9 0.00194230 00011111 9 0.00172731 01111110 9 0.00153532 100111110 10 0.00136533 101111110 10 0.00121334 101111111 10 0.00107935 110111110 10 0.00095936 011111110 10 0.00085337 011111111 10 0.00075838 1001111110 11 0.00067439 1001111111 11 0.00059940 1101111110 11 0.00053341 1101111111 11 0.00047442 Escape Word 1111111 16 0.00042143 ESC 16 0.00037444 ESC 16 0.00033345 ESC 16 0.00029646 ESC 16 0.00026347 ESC 16 0.000234and so forth until NW/2 = 255______________________________________Code Table Number: 6Number of Words: 511Scanner: 24.00Residual Probability 0.01000Actual Residual Probability 0.00989Mean Word Length: 6.5860Entropy: 6.5307______________________________________Code Word Number Huffman Code Word Length Probability______________________________________0 00000 5 0.0289761 0001 5 0.0277292 0010 5 0.0261453 0100 5 0.0246524 0110 5 0.0232445 10000 6 0.0219176 10010 6 0.0206657 10100 6 0.0194858 10110 6 0.0183729 11000 6 0.01732310 11010 6 0.01633311 11100 6 0.01540012 11110 6 0.01452113 00110 6 0.01369214 01010 6 0.01291015 01110 6 0.01217216 100010 7 0.01147717 100110 7 0.01082218 101010 7 0.01020319 101110 7 0.00962120 110010 7 0.00907121 110110 7 0.00855322 111010 7 0.00806523 111110 7 0.00760424 000010 7 0.00717025 001110 7 0.00676026 010110 7 0.00637427 011110 7 0.00601028 1000110 8 0.00566729 1001110 8 0.00534330 1010110 8 0.00503831 1011110 8 0.00475032 1100110 8 0.00447933 1101110 8 0.00422334 1110110 8 0.00398235 1111110 8 0.00375536 0000110 8 0.00354037 0011110 8 0.00333838 0101110 8 0.00314739 0111110 8 0.00296840 10001110 9 0.00279841 10001111 9 0.00263842 10011110 9 0.00248843 10111110 9 0.00234644 11001110 9 0.00221245 11011110 9 0.00208546 11101110 9 0.00196647 11111110 9 0.00185448 00001110 9 0.00174849 00111110 9 0.00164850 00111111 9 0.00155451 01011110 9 0.00146552 01111110 9 0.00138253 100111110 10 0.00130354 101111110 10 0.00122855 110011110 10 0.00115856 110111110 10 0.00109257 110111111 10 0.00103058 111011110 10 0.00097159 111111110 10 0.00091560 000011110 10 0.00086361 000011111 10 0.00081462 010111110 10 0.00076763 011111110 10 0.00072365 1001111111 11 0.00064366 1011111110 11 0.00060667 1100111110 11 0.00057268 1100111111 11 0.00053969 1110111110 11 0.00050870 1110111111 11 0.00047971 1111111110 11 0.00045272 1111111111 11 0.00042673 0101111110 11 0.00040274 0101111111 11 0.00037975 0111111110 11 0.00035776 0111111111 11 0.00033777 10111111110 12 0.00031878 10111111111 12 0.00029979 Escape Word 1010111 16 0.00028280 ESC 16 0.00026681 ESC 16 0.00025182 ESC 16 0.00023783 ESC 16 0.00022384 ESC 16 0.000210and so forth until NW/2 = 255______________________________________Code Table Number: 7Number of Words: 511Scanner: 48.00Residual Probability 0.03000Actual Residual Probability 0.02943Mean Word Length 7.6155Entropy: 7.5384______________________________________Code Word Number Huffman Code Word Length Probability______________________________________0 000000 6 0.0144531 00010 6 0.0141412 00100 6 0.0137353 00110 6 0.0133424 00111 6 0.0129595 01000 6 0.0125876 01010 6 0.0122267 01100 6 0.0118768 01110 6 0.0115359 100000 7 0.01120410 100010 7 0.01088311 100100 7 0.01057112 100110 7 0.01026813 101000 7 0.00997314 101010 7 0.00968715 101100 7 0.00940916 101110 7 0.00913917 110000 7 0.00887718 110010 7 0.00862319 110100 7 0.00837520 110110 7 0.00813521 111000 7 0.00790222 111010 7 0.00767523 111100 7 0.00745524 000001 7 0.00724125 000010 7 0.00703426 000110 7 0.00683227 001010 7 0.00663628 010010 7 0.00644629 010110 7 0.00626130 011010 7 0.00608131 011110 7 0.00590732 1000010 8 0.00573733 1000110 8 0.00557335 1001110 8 0.00525836 1010010 8 0.00510737 1010110 8 0.00496138 1011010 8 0.00481839 1011011 8 0.00468040 1011110 8 0.00454641 1100010 8 0.00441642 1100110 8 0.00428943 1101010 8 0.00416644 1101110 8 0.00404645 1110010 8 0.00393046 1110110 8 0.00381847 1111010 8 0.00370848 0000110 8 0.00360249 0001110 8 0.00349850 0010110 8 0.00339851 0100110 8 0.00330152 0100111 8 0.00320653 0101110 8 0.00311454 0110110 8 0.00302555 0111110 8 0.00293856 10000110 9 0.00285457 10001110 9 0.00277258 10010110 9 0.00269259 10011110 9 0.00261560 10011111 9 0.00254061 10100110 9 0.00246762 10101110 9 0.00239763 10111110 9 0.00232864 11000110 9 0.00226165 11001110 9 0.00219666 11010110 9 0.00213367 11011110 9 0.00207268 11011111 9 0.00201369 11100110 9 0.00195570 11101110 9 0.00189971 11110110 9 0.00184472 00001110 9 0.00179273 00011110 9 0.00174074 00101110 9 0.00169075 00101111 9 0.00164276 01011110 9 0.00159577 01101110 9 0.00154978 01111110 9 0.00150579 01111111 9 0.00146180 100001110 10 0.00141981 100011110 10 0.00137982 1001k01110 10 0.00133983 1001011111 10 0.00130184 101001110 10 0.00126385 101011110 10 0.00122786 101111110 10 0.00119287 101111111 10 0.00115888 110001110 10 0.00112589 110011110 10 0.00109290 110101110 10 0.00106191 110101111 10 0.00103192 111001110 10 0.00100193 111011110 10 0.00097294 111101110 10 0.00094495 111101111 10 0.00091796 000011110 10 0.00089197 000111110 10 0.00086698 000111111 10 0.00084199 010111110 10 0.000817100 010111111 10 0.000793101 011011110 10 0.000770102 011011111 10 0.000748103 1000011110 11 0.000727104 1000011111 11 0.000706105 1000011110 11 0.000686106 1000111111 11 0.000666107 1010011110 11 0.000647108 1010011111 11 0.000628109 1010111110 11 0.000610110 1010111111 11 0.000593111 1100011110 11 0.000576112 1100011111 11 0.000559113 1100111110 11 0.000543114 1100111111 11 0.000528115 1110011110 11 0.000513116 1110011111 11 0.000498117 1110111110 11 0.000484118 1110111111 11 0.000470119 0000111110 11 0.000456120 0000111111 11 0.000443121 Escape Word 11111 14 0.000431122 ESC 14 0.000418123 ESC 14 0.000406124 ESC 14 0.000395125 ESC 14 0.000383126 ESC 14 0.000372and so forth until NW/2 = 255______________________________________(B) Code tables for transmitted subregion and class affiliation:11 unmoved class00 Greatest Detail content01 Mean Detail content10 Smallest Detail contentIn the moved classes subregion is codes as follows:(1) N.sub.O = 1No. of diagonals equal code word number in"Huffman Code Table for subregion(2) Code Word number 32 escape word for:N.sub.D > 16 and simultaneous N.sub.O ≧ 4Escape word is transmitted first and N.sub.D is then transmittedwith 4 bits and N.sub.O transmitted with 5 bits total 16 bits.(3) Following Table valid for4 ≦ N.sub.O ≦ 16 and simultaneous 4 ≦ N.sub.D≦ 16The code word number in "Huffman code table for subregion"Possible combination for ND and NO then for subregions.______________________________________NO↓ND→ 4 5 6 7 8 9 10 11 12 13 14 15 16 4 33 34 35 36 37 38 39 40 41 42 43 44 45 5 46 47 48 49 50 51 52 53 54 55 56 57 6 58 59 60 61 62 63 64 65 66 67 68 7 69 70 71 72 73 74 75 76 77 78 8 79 80 81 82 83 84 85 86 87 9 88 89 90 91 92 93 94 9510 96 97 98 99 100 101 10211 103 104 105 106 107 10812 109 110 111 112 11313 114 115 116 11714 118 119 12015 121 12216 123______________________________________Huffman Code Table for subregionDivision Content: 6.94251Entropy: 5.29115Mid word length 5.34360______________________________________Code Word Number Huffman Code Word Length Probability______________________________________1 0000 4 0.0555312 0100 4 0.0555313 0101 4 0.0555314 0110 4 0.0555315 0111 4 0.0555316 1000 4 0.0555317 1001 4 0.0555318 1010 4 0.0555319 1011 4 0.05553110 1100 4 0.05553111 00010 5 0.02776612 11010 5 0.02776613 11011 5 0.02776614 11100 5 0.02776615 11101 5 0.02776616 11110 5 0.02776617 000110 6 0.01388318 111110 6 0.01388319 00011100 8 0.00347120 00011110 8 0.00347121 0001110100 10 0.00086822 0001110110 10 0.00086823 0001110111 10 0.00086824 0001111100 10 0.00086825 00011101010 11 0.00043426 00011111010 11 0.00043427 00011111011 11 0.00043428 00011111100 11 0.00043429 00011111101 11 0.00043430 00011111110 11 0.00043431 00011111111 11 0.00043432 1111110 7 0.00694133 001000 6 0.02776634 1111111 7 0.00694135 00100100 8 0.00694136 001001010 9 0.00347137 001001011 9 0.00347138 001001100 9 0.00347139 001001101 9 0.00347140 001001110 9 0.00347141 0010011110 10 0.00173542 0010011111 10 0.00173543 00101000000 11 0.00086844 00101000001 11 0.00086846 0010101 7 0.01388347 00101001 8 0.00694148 001010001 9 0.00347149 001011000 9 0.00347150 001011001 9 0.00347151 0010110100 10 0.00173552 00101000011 11 0.00086853 00101101010 11 0.00086854 00101101011 11 0.00086855 00101101100 11 0.00086856 001010000101 12 0.00043457 001011011010 12 0.00043458 0010111 7 0.01388359 001100000 9 0.00347160 001100001 9 0.00347161 001100010 9 0.00347162 0010110111 10 0.00173563 00110001100 11 0.00086864 00110001101 11 0.00086865 00110001110 11 0.00086866 00110001111 11 0.00086867 001011011011 12 0.00043468 001100100000 12 0.00043469 0011010 7 0.01388370 001100101 9 0.00347171 001100110 9 0.00347172 0011001001 10 0.00173573 00110010001 11 0.00086874 00110011100 11 0.00086875 00110011101 11 0.00086876 00110011110 11 0.00086877 001100100001 12 0.00043478 001100111110 12 0.00043479 00110110 8 0.00694180 001101110 9 0.00347181 0011011110 10 0.00173582 00110111110 11 0.00086883 00110111111 11 0.00086884 00111000000 11 0.00086885 00111000001 11 0.00086886 001100111111 12 0.00043487 001110000100 12 0.00043488 00111001 8 0.00694189 0011100010 10 0.00173590 00111000011 11 0.00086891 00111000110 11 0.00086892 00111000111 11 0.00086893 00111010000 11 0.00086894 001110000101 12 0.00043495 001110100010 12 0.00043496 00111011 8 0.00694197 00111010010 11 0.00086898 00111010011 11 0.00086899 00111010100 11 0.000868100 00111010101 11 0.000868101 001110100011 12 0.000434102 001110101100 12 0.000434103 00111000 9 0.003471104 00111010111 11 0.000868105 00111100100 11 0.000868106 00111100101 11 0.000868107 001110101101 12 0.000434108 001111001100 12 0.000434109 001111010 9 0.003471110 00111100111 11 0.000868111 00111101100 11 0.000868113 001111011010 12 0.000434114 001111100 9 0.003471115 00111101110 11 0.000868116 001111011011 12 0.000434117 001111011110 12 0.000434118 001111101 9 0.003471119 001111011111 12 0.000434120 000111010110 12 0.000434121 001111110 9 0.003471122 000111010111 12 0.000434123 001111111 9 0.003471______________________________________
TABLE 2______________________________________Allocation Matrices Fixed Allocation Huffman CodeTable for the Three Moved Classes______________________________________CLASS 17 6 5 4 4 3 3 3 2 2 2 2 1 1 1 16 5 4 4 3 3 3 2 2 2 2 1 1 1 1 15 4 4 3 3 3 2 2 2 2 1 1 1 1 1 14 4 3 3 3 2 2 2 2 1 1 1 1 1 1 14 3 3 3 2 2 2 2 1 1 1 1 1 1 1 13 3 3 2 2 2 2 1 1 1 1 1 1 1 1 13 3 2 2 2 2 1 1 1 1 1 1 1 1 1 13 2 2 2 2 1 1 1 1 1 1 1 1 1 1 12 2 2 2 1 1 1 1 1 1 1 1 1 1 1 12 2 2 1 1 1 1 1 1 1 1 1 1 1 1 12 2 1 1 1 1 1 1 1 1 1 1 1 1 1 12 1 1 1 1 1 1 1 1 1 1 1 1 1 1 11 1 1 1 1 1 1 1 1 1 1 1 1 1 1 11 1 1 1 1 1 1 1 1 1 1 1 1 1 1 11 1 1 1 1 1 1 1 1 1 1 1 1 1 1 11 1 1 1 1 1 1 1 1 1 1 1 1 1 1 1CLASS 27 5 4 3 3 2 2 2 1 1 1 1 1 1 1 15 4 3 3 2 2 2 1 1 1 1 1 1 1 1 14 3 3 2 2 2 1 1 1 1 1 1 1 1 1 13 3 2 2 2 1 1 1 1 1 1 1 1 1 1 13 2 2 2 1 1 1 1 1 1 1 1 1 1 1 12 2 2 1 1 1 1 1 1 1 1 1 1 1 1 12 2 1 1 1 1 1 1 1 1 1 1 1 1 1 12 1 1 1 1 1 1 1 1 1 1 1 1 1 1 11 1 1 1 1 1 1 1 1 1 1 1 1 1 1 11 1 1 1 1 1 1 1 1 1 1 1 1 1 1 11 1 1 1 1 1 1 1 1 1 1 1 1 1 1 11 1 1 1 1 1 1 1 1 1 1 1 1 1 1 11 1 1 1 1 1 1 1 1 1 1 1 1 1 1 11 1 1 1 1 1 1 1 1 1 1 1 1 1 1 11 1 1 1 1 1 1 1 1 1 1 1 1 1 1 11 1 1 1 1 1 1 1 1 1 1 1 1 1 1 1CLASS 37 4 3 2 2 1 1 1 1 1 1 1 1 1 1 14 3 2 2 1 1 1 1 1 1 1 1 1 1 1 13 2 2 1 1 1 1 1 1 1 1 1 1 1 1 12 2 1 1 1 1 1 1 1 1 1 1 1 1 1 12 1 1 1 1 1 1 1 1 1 1 1 1 1 1 11 1 1 1 1 1 1 1 1 1 1 1 1 1 1 11 1 1 1 1 1 1 1 1 1 1 1 1 1 1 11 1 1 1 1 1 1 1 1 1 1 1 1 1 1 11 1 1 1 1 1 1 1 1 1 1 1 1 1 1 11 1 1 1 1 1 1 1 1 1 1 1 1 1 1 11 1 1 1 1 1 1 1 1 1 1 1 1 1 1 11 1 1 1 1 1 1 1 1 1 1 1 1 1 1 11 1 1 1 1 1 1 1 1 1 1 1 1 1 1 11 1 1 1 1 1 1 1 1 1 1 1 1 1 1 11 1 1 1 1 1 1 1 1 1 1 1 1 1 1 11 1 1 1 1 1 1 1 1 1 1 1 1 1 1 1______________________________________
Although the invention has been described with respect to preferred embodiments, it is not to be so limited as changes and modifications can be made which are within the full intended scope of the invention as defined by the appended claims.
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Method and apparatus for the reduction of picture data for digital video signals comprising a processing of the signals by means of block by block transformation method so that a transformed and quantized signal which was generated at a time t-1 and placed in an image storage is subtracted from a transformed signal that occurs at a time t and whereby the difference signal obtained is subject to quantization and the quantized difference signal is subjected to an analysis and to a time delay which corresponds to the time requirement for the analysis for updating the content of the image storage. The signal delayed is added to the signal read out from the image storage which is also delayed and is added dependent on the addition condition signal obtained from the analysis and is subjected to an entropy coding dependent on the analysis results with the addition condition signals containing information as to whether a block which has been analyzed has been concluded is a moved or unmoved block and when the block is a moved block containing information regarding a coefficient group to be transmitted. The signal coded in such fashion is subjected to a buffering and depending on the degree of buffer filling a quantization stage and an analysis stage is influenced so that a signal from a buffer control is supplied to the quantization stage for the purpose of selecting one of a plurality of predetermined quantization characteristics and a second signal is supplied from the buffer control means to the analysis stage to select the maximum number of coefficient groups and a third signal is supplied to the analysis stage from the buffer control for the purpose of deciding whether a block is to be transmitted or not and the coefficients represent the digitized video signal transformed by block which is subdivided into coefficient groups.
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CROSS REFERENCE TO OTHER APPLICATIONS
[0001] This application claims priority to International (PCT) Application No. PCT/CN2015/085912 entitled METHOD AND DEVICE FOR ACHIEVING O2O INTERNET SERVICE, filed Aug. 3, 2015 which is incorporated herein by reference for all purposes, which claims priority to People's Republic of China Patent Application No. 201410403495.2 entitled METHOD AND DEVICE FOR REALIZING O2O INTERNET SERVICE, filed Aug. 15, 2014 which is incorporated herein by reference for all purposes.
FIELD OF THE INVENTION
[0002] The present application relates to a field of network communications technology. In particular, it relates to a method and a device for implementing Internet services.
BACKGROUND OF THE INVENTION
[0003] As network communications technology develops, it becomes not only possible to acquire various kinds of information online, but also to shop and do other things online. Many O2O Internet service providers not only have stores on the Internet (also called online stores), but also have physical stores offline (also called offline stores). These O2O Internet service providers can provide O2O (Online-to-Offline) Internet services. That is, they combine offline commercial opportunities with the Internet in such a way that the Internet becomes the front desk for offline transactions.
[0004] The method that is often used now to implement O2O Internet services is the following: acquire the current location information for a mobile terminal using the mobile terminal's location-based services (LBS); use the current location information for the mobile terminal to search for O2O Internet services in the vicinity of the mobile terminal; push found O2O Internet services to the mobile terminal; the user uses the pushed O2O Internet services as a basis for determining to use an O2O Internet service by having the mobile terminal log on to a corresponding O2O Internet service page.
[0005] However, the existing method for implementing O2O Internet services requires the use of mobile terminal LBS to acquire the current location information for a mobile terminal. Accurate location is impossible while indoors. When the user of a mobile terminal is indoors, it is not possible to acquire current location information for the mobile terminal or provide the user with accurate O2O Internet services.
SUMMARY OF THE INVENTION
[0006] The technical problem that the present application seeks to solve lies in a method and a device for implementing O2O Internet services. It uses the WiFi router identifier for WiFi signals in the vicinity of a mobile terminal as a basis for providing O2O Internet service to the mobile terminal user. Even when the mobile terminal user is indoors, it can provide the mobile terminal user accurate O2O Internet service associated with the user's current location.
[0007] To solve the problem described above, the present application discloses a method of implement O2O Internet services. Said method comprises: acquiring at least one WiFi signal scanned by a mobile terminal; analyzing said WiFi signals that meet set conditions in order to obtain first WiFi router identifiers corresponding to each of said analyzed WiFi signals; determining a second WiFi router identifier that is matched with an O2O Internet service from among the first WiFi router identifiers corresponding to each of said WiFi signals; using the Web operating environment built into said mobile terminal to acquire an O2O Internet service matched with said second WiFi router identifier.
[0008] Furthermore, determining a second WiFi router identifier that is matched with an O2O Internet service from among the first WiFi router identifiers corresponding to each of said WiFi signals comprises: comparing the first WiFi router identifier corresponding to each of said WiFi signals with WiFi router identifiers for O2O Internet services registered on an O2O Internet service platform; determining the first WiFi router identifier whose comparison result is the same to be the second WiFi router identifier, which is matched with an O2O Internet service.
[0009] Furthermore, after acquiring an O2O Internet service matched with said second WiFi router identifier, it further comprises: acquiring descriptive store information for an O2O Internet service provider of an O2O Internet service matched with said second WiFi router identifier; recording the descriptive store information for an O2O Internet service provider of an O2O Internet service matched with said second WiFi router identifier.
[0010] Furthermore, said WiFi signals that meet set conditions comprise: the strongest WiFi signal among said acquired WiFi signals; or of said acquired WiFi signals, those WiFi signals whose strength exceeds a set threshold value; or a preset quantity of said acquired WiFi signals ranked in strong-to-weak signal strength order.
[0011] Furthermore, prior to acquiring at least one WiFi signal scanned by a mobile terminal, it further comprises: acquiring an O2O Internet service registry, wherein said O2O Internet service registry comprises registration information on multiple O2O Internet service providers that provide O2O Internet services, wherein said registration information on the O2O Internet service providers comprises O2O Internet service addresses of said O2O Internet service providers and WiFi router identifiers for said O2O Internet service providers; storing said O2O Internet service registry.
[0012] Furthermore, said registration information on the O2O Internet service providers further comprises: descriptive store information about said O2O Internet service providers, wherein said descriptive store information is used by the user of said mobile terminal for identifying and shopping, or said descriptive store information is used by said mobile terminal for navigation to said store location.
[0013] Furthermore, acquiring the O2O Internet service matched with said second WiFi router identifier comprises: using said second WiFi router identifier as a basis for determining an O2O Internet service address included in the corresponding registration information; using said O2O Internet service address as a basis for acquiring an O2O Internet service matched with said second WiFi router identifier.
[0014] Furthermore, after using the Web operating environment built into said mobile terminal to acquire an O2O Internet service matched with said second WiFi router identifier, it further comprises: receiving the WiFi code that is sent by the WiFi router corresponding to said second WiFi router identifier; on the basis of said WiFi code using the WiFi signal provided by the WiFi router corresponding to said second WiFi router identifier to connect to the Internet.
[0015] Furthermore, after using the Web operating environment built into said mobile terminal to acquire an O2O Internet service matched with said second WiFi router identifier, it further comprises: using said mobile terminal to log onto an O2O Internet service matched with said second WiFi router identifier and submitting service subscription information; receiving service subscription result information corresponding to said service subscription information.
[0016] Furthermore, after using the Web operating environment built into said mobile terminal to acquire an O2O Internet service matched with said second WiFi router identifier, it comprises: using the Web operating environment built into said mobile terminal to receive an O2O Internet service pushed by an O2O Internet service provider matched with said second WiFi router identifier; or after receiving a service acquisition trigger instruction, using the Web operating environment built into said mobile terminal to acquire an O2O Internet service matched with said second WiFi router identifier.
[0017] Furthermore, said O2O Internet service comprises: pushed information provided by the O2O Internet service provider, or service information provided by the O2O Internet service provider, or descriptive information provided by the O2O Internet service provider.
[0018] To solve the problem described above, the present application further discloses a device for implementing O2O Internet services. Said device comprises: a first acquiring module, for acquiring at least one WiFi signal scanned by a mobile terminal; an analyzing module, for analyzing said WiFi signals that meet set conditions in order to obtain first WiFi router identifiers corresponding to each of said analyzed WiFi signals; a determining module, for determining a second WiFi router identifier that is matched with an O2O Internet service from among the first WiFi router identifiers corresponding to each of said WiFi signals; a second acquiring module, for using the Web operating environment built into said mobile terminal to acquire an O2O Internet service matched with said second WiFi router identifier.
[0019] Furthermore, said determining module comprises: a comparing unit, for comparing the first WiFi router identifier corresponding to each of said WiFi signals with WiFi router identifiers for O2O Internet services registered on an O2O Internet service platform; a determining unit, for determining the first WiFi router identifier whose comparison result is the same to be the second WiFi router identifier, which is matched with an O2O Internet service.
[0020] Furthermore, said device further comprises: a third acquiring module, for acquiring descriptive store information for an O2O Internet service provider of an O2O Internet service matched with said second WiFi router identifier; a first recording module, for recording the descriptive store information for an O2O Internet service provider of an O2O Internet service matched with said second WiFi router identifier.
[0021] Furthermore, said WiFi signals that meet set conditions comprise: the strongest WiFi signal among said acquired WiFi signals; or of said acquired WiFi signals, those WiFi signals whose strength exceeds a set threshold value; or a preset quantity of said acquired WiFi signals ranked in strong-to-weak signal strength order.
[0022] Furthermore, said device further comprises: a fourth acquiring module, for acquiring an O2O Internet service registry, wherein said O2O Internet service registry comprises registration information on multiple O2O Internet service providers that provide O2O Internet services, wherein said registration information on O2O Internet service providers comprises O2O Internet service addresses of said O2O Internet service providers and WiFi router identifiers for said O2O Internet service providers; a storage module, for storing said O2O Internet service registry.
[0023] Furthermore, said registration information on O2O Internet service providers further comprises: descriptive store information about said O2O Internet service providers, wherein said descriptive store information is used by the user of said mobile terminal for identifying and shopping, or said descriptive store information is used by said mobile terminal for navigation to said store location.
[0024] Furthermore, said second acquiring module comprises: a processing unit, for using said second WiFi router identifier as a basis for determining an O2O Internet service address included in the corresponding registration information; an acquiring unit, for using the O2O Internet service address as a basis for acquiring the O2O Internet service matched with said second WiFi router identifier.
[0025] Furthermore, said device further comprises: a first receiving module, for receiving the WiFi code that is sent by the WiFi router corresponding to said second WiFi router identifier; a processing module, for, on the basis of said WiFi code, using the WiFi signal provided by the WiFi router corresponding to said second WiFi router identifier to connect to the Internet.
[0026] Furthermore, said device further comprises: a submitting module, for using said mobile terminal to log onto an O2O Internet service matched with said second WiFi router identifier and submitting service subscription information; a second receiving module, for receiving service subscription result information corresponding to said service subscription information.
[0027] Furthermore, said second acquiring module comprises: a first receiving unit, for using the Web operating environment built into said mobile terminal to receive an O2O Internet service pushed by an O2O Internet service provider matched with said second WiFi router identifier; or a second receiving unit, for, after receiving a service acquisition trigger instruction, using the Web operating environment built into said mobile terminal to acquire an O2O Internet service matched with said second WiFi router identifier.
[0028] Furthermore, said O2O Internet service comprises: pushed information provided by the O2O Internet service provider, or service information provided by the O2O Internet service provider, or descriptive information provided by the O2O Internet service provider.
[0029] The present application can obtain at least the following technical results: 1) It provides O2O Internet services based on WiFi router identifiers of WiFi signals. Since all the WiFi signals scanned by a mobile terminal are WiFi signals in the vicinity of the mobile terminal, and O2O Internet service is provided to the mobile terminal user according to the WiFi router identifier for WiFi signals in the vicinity of the mobile terminal, it can provide the mobile terminal user accurate O2O Internet service associated with the user's current location even when the mobile terminal user is indoors.
[0030] 2) Acquiring at least one WiFi signal scanned by a remote terminal and providing O2O Internet service based on the WiFi signal's WiFi router identifier does not require the remote terminal user to perform any preceding step. The matching is automatic, and the interactions are simple.
[0031] 3) The O2O Internet service corresponding to the WiFi signal with the greatest signal strength is provided on the basis of the WiFi signal strength and the WiFi router identifier. The O2O Internet service provided for the mobile terminal user is nearer to the mobile terminal user and is more convenient to the user.
[0032] 4) Successfully matched O2O Internet services are automatically recorded. That is, visited O2O Internet service provider physical stores are automatically recorded for the convenience of repeat visits by users.
[0033] Of course, any product that implements the present application does not have to simultaneously achieve all of the technical results described above.
BRIEF DESCRIPTION OF THE DRAWINGS
[0034] The drawings described here are both intended to further the understanding of the present application and form a part of the present application. The exemplary embodiments of the present application and the descriptions thereof are intended to explain the present application and do not constitute inappropriate limitation of the present application. Among the drawings:
[0035] FIG. 1 is a flowchart of a first method of implementing O2O Internet services in an embodiment of the present application.
[0036] FIG. 2 is a flowchart of a second method of implementing O2O Internet services in an embodiment of the present application.
[0037] FIG. 3 is a flowchart of a third method of implementing O2O Internet services in an embodiment of the present application.
[0038] FIG. 4 is a flowchart of a fourth method of implementing O2O Internet services in an embodiment of the present application.
[0039] FIG. 5 is a diagram of a particular method of implementing O2O Internet services in an embodiment of the present application.
[0040] FIG. 6 is a diagram of another particular method of implementing O2O Internet services in an embodiment of the present application.
[0041] FIG. 7 is a structural diagram of a first device for implementing O2O Internet services in an embodiment of the present application.
[0042] FIG. 8 is a structural diagram of a second device for implementing O2O Internet services in an embodiment of the present application.
[0043] FIG. 9 is a structural diagram of a third device for implementing O2O Internet services in an embodiment of the present application.
[0044] FIG. 10 is a structural diagram of a fourth device for implementing O2O Internet services in an embodiment of the present application.
[0045] FIG. 11 is a structural diagram of a fifth device for implementing O2O Internet services in an embodiment of the present application.
DETAILED DESCRIPTION
[0046] Implementations of the present application are explained in detail below in light of the attached drawings and embodiments in order to provide an adequate understanding of how the present application applies technical means to solve technical problems and achieve technical effects and to provide a basis for implementation of the same.
[0047] In one typical configuration, computer equipment comprises one or more processors (CPUs), input/output interfaces, network interfaces and memory.
[0048] Memory may include such forms as volatile memory in computer-readable media, random access memory (RAM) and/or non-volatile memory, such as read-only memory (ROM) or flash memory (flash RAM). Memory is an example of a computer-readable medium.
[0049] Computer-readable media, including permanent and non-permanent and removable and non-removable media, may achieve information storage by any method or technique. Information can be computer-readable commands, data structures, program modules, or other data. Examples of computer storage media include but are not limited to phase-change memory (PRAM), static random access memory (SRAM), dynamic random access memory (DRAM), other types of random access memory (RAM), read-only memory (ROM), electrically erasable programmable read-only memory (EEPROM), flash memory or other memory technology, compact disk read-only memory (CD-ROM), digit multifunction disc (DVD) or other optical storage, magnetic cassettes, magnetic tape or magnetic disc storage, or other magnetic storage equipment or any other non-transmission media that can be used to store information that is accessible to computers. As defined in this document, computer-readable media does not include transitory computer-readable media, (transitory media), such as modulated data signals and carrier waves.
Description of Embodiments
[0050] The embodiments below serve to provide a further explanation of how the present application methods are implemented. As shown in FIG. 1 , which is a flowchart of a method of implementing O2O Internet services in an embodiment of the present application, the method comprises:
[0051] S 101 : Acquire at least one WiFi (Wireless Fidelity) signal scanned by a mobile terminal.
[0052] In particular, if the mobile terminal's WiFi is activated, the mobile terminal's OS (Operating System) (such as Android™) will automatically scan for WiFi signals in the vicinity and will find at least one WiFi signal sent by a broadcasting mechanism.
[0053] To make it possible to acquire in real time at least one WiFi signal sent through a broadcasting mechanism, it is possible to register and monitor broadcasts with WiFi signal scans and acquire in real time at least one most recently scanned WiFi signal sent by a broadcasting mechanism.
[0054] S 102 : Analyze WiFi signals that meet set conditions in order to obtain first WiFi router identifiers corresponding to each analyzed WiFi signal.
[0055] The WiFi router identifier specifically may be the BSSID (Basic Service Set ID) of the WiFi router. The BSSID is the WiFi router's physical address, which can uniquely identify this WiFi router.
[0056] WiFi signals that meet set conditions include:
[0057] the strongest WiFi signal among the acquired WiFi signals; or
[0058] those acquired WiFi signals whose strength exceeds a set threshold value; or
[0059] a preset quantity of acquired WiFi signals ranked in strong-to-weak signal strength order.
[0060] S 103 : Determine a second WiFi router identifier that is matched with an O2O Internet service from among the first WiFi router identifiers corresponding to each WiFi signal.
[0061] Specifically, in order to implement O2O Internet services through the method of the present embodiment, the O2O Internet service provider that can provide O2O Internet services is registered in advance on an O2O Internet service platform. When an O2O Internet service provider is registered on the O2O Internet service platform, the submitted registration information includes: descriptive store information (such as a store introduction and the store's geographic location) about the O2O Internet service provider, the O2O Internet service address (such a URL that browsers may directly access) of the O2O Internet service provider and a WiFi router identifier (such as the BSSID for a WiFi router) of the O2O Internet service provider. The descriptive store information is used by mobile terminal users for identifying service provider, or the descriptive store information is used by mobile terminals for navigation to the store location. Moreover, O2O Internet service providers can publish O2O Internet services in the form of Web apps.
[0062] Determining a second WiFi router identifier that is matched with an O2O Internet service from among the first WiFi router identifiers corresponding to each WiFi signal comprises:
[0063] comparing the first WiFi router identifier corresponding to each WiFi signal with WiFi router identifiers for O2O Internet services registered on an O2O Internet service platform;
[0064] determining the first WiFi router identifier whose comparison result is the same to be the second WiFi router identifier, which is matched with an O2O Internet service.
[0065] S 104 : Use the Web operating environment built into the mobile terminal to acquire the O2O Internet service matched with the second WiFi router identifier.
[0066] The Web operating environment built into the mobile terminal could be, for example, a 2G or 3G Web in the mobile terminal.
[0067] Using the Web operating environment built into a mobile terminal to acquire an O2O Internet service matched with a second WiFi router identifier comprises:
[0068] using the Web operating environment built into a mobile terminal to receive an O2O Internet service pushed by an O2O Internet service provider matched with a second WiFi router identifier; or
[0069] after receiving a service acquisition trigger instruction, using the Web operating environment built into a mobile terminal to acquire an O2O Internet service matched with a second WiFi router identifier.
[0070] Specifically, the service acquisition trigger instruction could be sent only when it is determined that there is a need to use an O2O Internet service. Only then is an O2O Internet service matched with a second WiFi router identifier acquired using the Web operating environment built into a mobile terminal. This can conserve traffic for the Web built into a mobile terminal.
[0071] Acquiring an O2O Internet service matched with a second WiFi router identifier comprises:
[0072] using the second WiFi router identifier as a basis for determining an O2O Internet service address included in the corresponding registration information;
[0073] using the O2O Internet service address as a basis for acquiring an O2O Internet service matched with the second WiFi router identifier.
[0074] Specifically, since all the WiFi signals scanned by a mobile terminal are WiFi signals in the vicinity of the mobile terminal, using the WiFi router identifier for WiFi signals in the vicinity of the mobile terminal as a basis for providing O2O Internet service to the mobile terminal user can happen when the mobile terminal user is indoors and can provide the mobile terminal user accurate O2O Internet service associated with the user's current location.
[0075] Specifically, O2O Internet services comprise: pushed information provided by O2O Internet service providers, service information provided by O2O Internet service providers or descriptive information provided by O2O Internet service providers.
[0076] Specifically, when the Web operating environment built into a mobile terminal serves to acquire an O2O Internet service matched with a second WiFi router identifier, it has already been determined that the mobile terminal user is located in a physical store or in the vicinity of a physical store. Therefore, after the Web operating environment built into a mobile terminal serves to acquire an O2O Internet service matched with a second WiFi router identifier, it further comprises:
[0077] receiving the WiFi code that is sent by the WiFi router corresponding to the second WiFi router identifier;
[0078] on the basis of the WiFi code using the WiFi signal provided by the WiFi router corresponding to the second WiFi router identifier to connect to the Internet.
[0079] Or, after the Web operating environment built into a mobile terminal serves to acquire an O2O Internet service matched with a second WiFi router identifier, it further comprises:
[0080] using the mobile terminal to log on to an O2O Internet service matched with the second WiFi router identifier and submitting service subscription information;
[0081] receiving service subscription result information corresponding to said service subscription information.
[0082] In accordance with the above descriptions, the application scenarios of the O2O Internet service of the present embodiment may comprise:
[0083] a: Automatic recommendation of a menu and online ordering
[0084] After the mobile terminal user uses the O2O Internet service, he or she can obtain special-price and special-dish menus recommended by the O2O Internet service and can directly place an order. This can solve the problem of insufficient information in traditional menus and can also help O2O Internet service provider save on service costs.
[0085] b: Waiting in line and having your number called
[0086] After a restaurant clears tables, and after a mobile terminal user uses the O2O Internet network service, it is possible join the online queue until one's number is called. The O2O Internet service provider may send a message to the user's mobile terminal notifying him or her of the availability of a table, thereby solving the problem of users needing to wait near the restaurant.
[0087] c: Automatic recommendations of hot products and online payment and orders
[0088] After a mobile terminal user who is browsing products in a store uses an O2O Internet service, he or she can see recommended hot products. This enables the user to save on product searching time.
[0089] d: Automatically sending coupons
[0090] When a mobile terminal user is passing by a store, a store coupon may be automatically sent based on a notification center for the purpose of drawing the user into the store to spend. It's also an even more convenient way for users to use coupons.
[0091] e: Automatically connecting to a WiFi signal
[0092] When a mobile terminal user is in a physical store or in the vicinity of a physical store, a WiFi code is automatically sent to the mobile terminal enabling the mobile terminal to automatically connect with the WiFi signal and to use the WiFi signal to connect to the Internet.
[0093] Refer to FIG. 2 , which is a flowchart of a method of implementing O2O Internet services in an embodiment of the present application. After S 104 , using the Web operating environment built into a mobile terminal to acquire the O2O Internet service matched with a second WiFi router identifier, it further comprises:
[0094] S 105 : Acquire descriptive store information for the O2O Internet service provider of the O2O Internet service matched with the second WiFi router identifier.
[0095] S 106 : Record the descriptive store information for the O2O Internet service provider of the O2O Internet service matched with the second WiFi router identifier.
[0096] Specifically, when the O2O Internet service matched with the second WiFi router identifier is acquired, i.e., after the WiFi router identifier has been successfully matched, record the descriptive store information for the O2O Internet service provider of the O2O Internet service matched with the second WiFi router identifier. This will enable the mobile terminal user to conveniently find a store's geographic location by using the store's descriptive information that is among previously browsed stores in the matched history and thus to revisit a previously visited store. Additionally, this will bring more old customers to the O2O Internet service provider.
[0097] Refer to FIG. 3 , which is a flowchart of a method of implementing O2O Internet services in an embodiment of the present application. Prior to S 101 , acquiring at least one WiFi signal scanned through a mobile terminal, it further comprises:
[0098] S 107 : Acquire an O2O Internet service registry.
[0099] The O2O Internet service registry includes registration information on multiple O2O Internet service providers that provide O2O Internet services, wherein the registration information on O2O Internet service providers comprises: descriptive store information about O2O Internet service providers, O2O Internet service addresses of O2O Internet service providers and WiFi router identifiers for O2O Internet service providers. The descriptive store information is used by mobile terminal users for identifying and shopping, or the descriptive store information is used by mobile terminals for navigation to the store location.
[0100] Specifically, in order to implement an O2O Internet service through the method of the present embodiment, the O2O Internet service provider that can provide the O2O Internet service registers in advance on an O2O Internet service platform. When the O2O Internet service provider registers on an O2O Internet service platform, it submits registration information.
[0101] S 108 : Store the O2O Internet service registry.
[0102] Please note that, where a remote terminal user uses a WiFi router identifier for at least one acquired WiFi signal scanned by the mobile terminal as a basis for searching for O2O Internet services, if the WiFi signals that meet a set condition are: those of the acquired WiFi signals whose strength exceeds a set threshold value or a preset quantity of the acquired WiFi signals ranked in strong-to-weak signal strength order, then multiple O2O Internet services may be found for the mobile terminal user in his or her vicinity. In an actual application, the mobile terminal user might be most concerned about the nearest O2O Internet service. Therefore, the WiFi signal that meets the set condition in the present embodiment is: the strongest WiFi signal among the WiFi signals that were acquired. To provide a further explanation, refer to FIG. 4 , which is a flowchart of a method of implementing O2O Internet services in an embodiment of the present application. The method comprises:
[0103] S 201 : Acquire at least one WiFi signal scanned by a mobile terminal.
[0104] Specifically, this is similar to step S 101 and will not be discussed further here.
[0105] S 202 : Analyze each WiFi signal to obtain the signal strength of each WiFi signal and the corresponding first WiFi router identifier.
[0106] S 203 : According to the signal strength of each WiFi signal, select from the at least one WiFi signal the WiFi signal with the greatest signal strength.
[0107] Specifically, according to the signal strength of each WiFi signal, the at least one WiFi signal is ranked in strong-to-weak signal strength order, and the WiFi signal with the greatest signal strength is selected from at least one WiFi signal.
[0108] S 204 : Determine whether the third WiFi router identifier corresponding to the WiFi signal with the greatest signal strength is matched with an O2O Internet service.
[0109] Determining whether a third WiFi router corresponding to the WiFi signal with the greatest signal strength is matched with an O2O Internet service comprises:
[0110] comparing the third WiFi router corresponding to the WiFi signal with the greatest signal strength to WiFi router identifiers for O2O Internet services registered on an O2O Internet service platform;
[0111] if there is a WiFi router identifier among the WiFi router identifiers for registered O2O Internet services on the O2O Internet service platform that is consistent with the third WiFi router identifier, then determine that the third WiFi router identifier is matched with an O2O Internet service;
[0112] if there is no WiFi router identifier among all the WiFi router identifiers for registered O2O Internet services on the O2O Internet service platform that is consistent with the third WiFi router identifier, then determine that the third WiFi router identifier is not matched with an O2O Internet service.
[0113] S 205 : If the third WiFi router identifier corresponding to the WiFi signal with the greatest signal strength is matched with an O2O Internet service, then use the Web operating environment built into the mobile terminal to acquire the O2O Internet service matched with the third WiFi router identifier.
[0114] Specifically, this is similar to step S 104 and will not be discussed further here.
[0115] After using the Web operating environment built into the mobile terminal to acquire the O2O Internet service matched with the third WiFi router identifier, it further comprises:
[0116] acquiring descriptive store information about the O2O Internet service provider of the O2O Internet service matched with the third WiFi router identifier;
[0117] recording descriptive store information about the O2O Internet service provider of the O2O Internet service matched with the third WiFi router identifier.
[0118] The method of implementing O2O Internet services described by the present embodiment provides O2O Internet services based on WiFi router identifiers of WiFi signals. Specifically, since all the WiFi signals scanned by a mobile terminal are WiFi signals in the vicinity of the mobile terminal, using the WiFi router identifier for WiFi signals in the vicinity of the mobile terminal as a basis for providing O2O Internet service to the mobile terminal user can happen when the mobile terminal user is indoors and can provide the mobile terminal user accurate O2O Internet service associated with the user's current location. Acquiring at least one WiFi signal scanned by a remote terminal and providing O2O Internet service based on the WiFi signal's WiFi router identifier does not require the remote terminal user to perform any preceding step. The matching is automatic, and the interactions are simple. The O2O Internet service corresponding to the WiFi signal with the greatest signal strength is provided on the basis of the WiFi signal strength and the WiFi router identifier. The O2O Internet service provided for the mobile terminal user is nearer to the mobile terminal user and is more convenient to the user.
[0119] Successfully matched O2O Internet services are recorded. That is, visited O2O Internet service provider physical stores are recorded for the convenience of repeat visits by users.
[0120] Refer to FIGS. 5 and 6 , which are diagrams of a particular method of implementing O2O Internet services in an embodiment of the present application. The method comprises:
[0121] S 301 : An O2O Internet service provider registers an O2O Internet service on an O2O Internet service platform.
[0122] The O2O Internet service provider carries out the registration on the O2O Internet service platform. When the O2O Internet service provider carries out the registration on the O2O Internet service platform, it submits registration information.
[0123] The registration information of the O2O Internet service provider comprises: descriptive store information about the O2O Internet service provider, the O2O Internet service address of the O2O Internet service providers and the WiFi router identifier for the O2O Internet service provider.
[0124] S 302 : The O2O Internet service platform sends the O2O Internet service registry to the user's mobile terminal.
[0125] The O2O Internet service registry includes registration information on multiple O2O Internet service providers that provide O2O Internet services.
[0126] The O2O Internet service platform sends the O2O Internet service registry to the user's mobile terminal. Specifically, the O2O Internet service registry can be sent to the user mobile terminal via the mobile terminal OS push channel. Moreover, whenever the registration information in the O2O Internet service registry is updated, it will be synchronized with the user remote terminal based on the mobile terminal OS push channel.
[0127] S 303 : The mobile terminal detects and accesses the O2O Internet service of the O2O Internet service provider.
[0128] If, when the user arrives within the vicinity of the physical store of the O2O Internet service provider, his or her mobile terminal's WiFi is on, the mobile terminal OS (e.g., Android) automatically scans for WiFi signals in the vicinity and detects at least one WiFi signal sent by a broadcasting mechanism.
[0129] To make it possible to acquire in real time at least one WiFi signal sent by a broadcasting mechanism, it is possible to register and monitor broadcasts for WiFi signal scans and acquire in real time at least one most recently scanned WiFi signal sent by a broadcasting mechanism.
[0130] Moreover, during an actual application, each WiFi signal of the at least one WiFi signal that was acquired by remote terminal scanning can be analyzed, and the WiFi router identifier of each WiFi signal serves as a basis for finding O2O Internet services for the mobile terminal user. It is possible that multiple O2O Internet services will be found for the mobile terminal user within his or her vicinity. Moreover, each WiFi signal of the at least one WiFi signal that was acquired by remote terminal scanning can be analyzed, and the WiFi router identifier of the WiFi signal with the greatest signal strength serves as a basis for finding an O2O Internet service for the mobile terminal user. The O2O Internet service nearest to the remote terminal user may be found.
[0131] S 304 : The O2O Internet service provider provides O2O Internet service.
[0132] If an O2O Internet service is found using a WiFi signal, then the mobile terminal user is definitely located inside the physical store or in the vicinity of the physical store. Therefore, the application scenarios of the O2O Internet services of the present embodiment may include:
[0133] a: Automatic recommendation of a menu and online ordering
[0134] After the mobile terminal user uses the O2O Internet service, he or she can obtain special-price and special-dish menus recommended by the O2O Internet service and can directly place an order. This can solve the problem of insufficient information in traditional menus and can also help the O2O Internet service provider save on service costs.
[0135] b: Waiting in line and having your number called
[0136] After a restaurant clears tables, and after a mobile terminal user uses the O2O Internet network service, it is possible to join the online queue until one's number is called. The O2O Internet service provider may send a message to the user's mobile terminal notifying him or her of the availability of a table, thereby solving the problem of users needing to wait near the restaurant.
[0137] c: Automatic recommendations of hot products and online payment and orders
[0138] After a mobile terminal user who is browsing products in a store uses an O2O Internet service, he or she can see recommended hot products. This enables the user to save on product searching time.
[0139] d: Automatically sending coupons
[0140] When a mobile terminal user is passing by a store, a store coupon may be automatically sent based on a notification center for the purpose of drawing the user into the store to spend. It's also an even more convenient way for users to use coupons.
[0141] e: Automatically connecting to a WiFi signal
[0142] When a mobile terminal user is in a physical store or in the vicinity of a physical store, a WiFi code is automatically sent to the mobile terminal enabling the mobile terminal to automatically connect with the WiFi signal and to use the WiFi signal to connect to the Internet.
[0143] As shown in FIG. 7 , which is a structural diagram of a device for implementing O2O Internet services in an embodiment of the present application, the device comprises:
[0144] a first acquiring module 401 , for acquiring at least one WiFi signal scanned by a mobile terminal;
[0145] an analyzing module 402 , for analyzing WiFi signals that meet set conditions in order to obtain first WiFi router identifiers corresponding to each analyzed WiFi signal;
[0146] a determining module 403 , for determining a second WiFi router identifier that is matched with an O2O Internet service from among the first WiFi router identifiers corresponding to each WiFi signal;
[0147] a second acquiring module 404 , for using the Web operating environment built into a mobile terminal to acquire an O2O Internet service matched with a second WiFi router identifier.
[0148] Furthermore, the determining module 403 comprises:
[0149] a comparing unit, for comparing the first WiFi router identifier corresponding to each WiFi signal with WiFi router identifiers for O2O Internet services registered on an O2O Internet service platform;
[0150] a determining unit, for determining the first WiFi router identifier whose comparison result is the same to be the second WiFi router identifier, which is matched with an O2O Internet service.
[0151] Furthermore, refer to FIG. 8 . The device further comprises:
[0152] a third acquiring module 405 , for acquiring descriptive store information for an O2O Internet service provider of an O2O Internet service matched with the second WiFi router identifier;
[0153] a first recording module 406 , for recording the descriptive store information for an O2O Internet service provider of an O2O Internet service matched with the second WiFi router identifier.
[0154] Furthermore, WiFi signals that meet set conditions comprise:
[0155] the strongest WiFi signal among the acquired WiFi signals; or
[0156] those acquired WiFi signals whose strength exceeds a set threshold value; or
[0157] a preset quantity of acquired WiFi signals ranked in strong-to-weak signal strength order.
[0158] Furthermore, refer to FIG. 9 . The device further comprises:
[0159] a fourth acquiring module 409 , for acquiring an O2O Internet service registry, wherein the O2O Internet service registry comprises registration information on multiple O2O Internet service providers that provide O2O Internet services, wherein the registration information on O2O Internet service providers comprises O2O Internet service addresses of O2O Internet service providers and WiFi router identifiers for O2O Internet service providers;
[0160] a storage module 410 , for storing the O2O Internet service registry.
[0161] Furthermore, the O2O Internet service provider registration information further comprises:
[0162] descriptive store information about O2O Internet service providers, wherein the descriptive store information is used by mobile terminal users for identifying and shopping, or the descriptive store information is used by mobile terminals for navigation to the store location.
[0163] Furthermore, the second acquiring module 404 comprises:
[0164] a processing unit, for using the second WiFi router identifier as a basis for determining an O2O Internet service address included in the corresponding registration information;
[0165] an acquiring unit, for using the O2O Internet service address as a basis for acquiring an O2O Internet service matched with the second WiFi router identifier.
[0166] Furthermore, refer to FIG. 10 . The device further comprises:
[0167] a first receiving module 411 , for receiving the WiFi code that is sent by the WiFi router corresponding to the second WiFi router identifier;
[0168] a processing module 412 , for on the basis of the WiFi code using the WiFi signal provided by the WiFi router corresponding to the second WiFi router identifier to connect to the Internet.
[0169] Furthermore, refer to FIG. 11 . The device further comprises:
[0170] a submitting module 413 , for using the mobile terminal to log on to an O2O Internet service matched with the second WiFi router identifier and submitting service subscription information;
[0171] a second receiving module 414 , for receiving service subscription result information corresponding to said service subscription information.
[0172] Furthermore, the second acquiring module 404 comprises:
[0173] a first receiving unit, for using the Web operating environment built into a mobile terminal to receive an O2O Internet service pushed by an O2O Internet service provider matched with a second WiFi router identifier; or
[0174] a second receiving unit, for, after receiving a service acquisition trigger instruction, using the Web operating environment built into a mobile terminal to acquire an O2O Internet service matched with a second WiFi router identifier.
[0175] Furthermore, the O2O Internet service comprises:
[0176] pushed information provided by the O2O Internet service provider, or
[0177] service information provided by the O2O Internet service provider, or
[0178] descriptive information provided by the O2O Internet service provider.
[0179] The device for implementing O2O Internet services described by the present embodiment provides O2O Internet services based on WiFi router identifiers of WiFi signals. Specifically, since all the WiFi signals scanned by a mobile terminal are WiFi signals in the vicinity of the mobile terminal, using the WiFi router identifier for WiFi signals in the vicinity of the mobile terminal as a basis for providing O2O Internet service to the mobile terminal user can happen when the mobile terminal user is indoors and can provide the mobile terminal user accurate O2O Internet service associated with the user's current location. Acquiring at least one WiFi signal scanned by a remote terminal and providing O2O Internet service based on the WiFi signal's WiFi router identifier does not require the remote terminal user to perform any preceding step. The matching is automatic, and the interactions are simple. The O2O Internet service corresponding to the WiFi signal with the greatest signal strength is provided on the basis of the WiFi signal strength and the WiFi router identifier. The O2O Internet service provided for the mobile terminal user is nearer to the mobile terminal user and is more convenient to the user.
[0180] Said device corresponds to the description of the aforesaid method steps. Where the information is insufficient, refer to the explanations of the aforesaid method steps. They will not be discussed in detail again.
[0181] The explanations above present and describe a number of preferred embodiments of the present application. However, as stated above, it should be understood that the present application is not limited to the forms disclosed in this document and should not be regarded as excluding other embodiments. Rather, they can be used in various other combinations, modifications and environments. Moreover, within the scope of the inventive concepts described herein, they can be altered using the instructions above or the techniques or knowledge of the associated fields. Alterations or changes made by persons skilled in the art that do not depart from the spirit and scope of the present application shall be within the protective scope of the claims attached to the present application.
[0182] Although the foregoing embodiments have been described in some detail for purposes of clarity of understanding, the invention is not limited to the details provided. There are many alternative ways of implementing the invention. The disclosed embodiments are illustrative and not restrictive.
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Providing internet service comprises: obtaining one or more wireless signals respectively associated with one or more corresponding network devices; obtaining one or more network device identifiers associated with at least one of the one or more wireless signals based at least in part on analysis of the one or more wireless signals; determining that at least one of the one or more network device identifiers corresponds to an Internet service, wherein the Internet service is dependent at least in part on a physical location of a terminal associated with the wireless signal; and accessing the Internet service associated with the at least one of the one or more network device identifiers corresponding to the Internet service.
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BACKGROUND OF THE INVENTION
1. Field
This invention relates generally to microbial growth media and specifically to an improved isolation medium for the rapid detection of pathogenic Neisseria, Neisseria gonorrhoeae and Neisseria meningitidis, the causative agents of gonnorrhea and cerebrospinal meningitis diseases.
2. Prior Art
Diagnosis of infection by pathogenic Neisseria requires the use of a suitable culture medium, one which will permit the in vitro growth of the pathogenic Neisseria and inhibit the growth of other bacteria. Typically, in the prior art, a specimen is inoculated onto the surface of a suitable medium and incubated under suitable conditions for a period of time up to 48 hours. Pathogenic Neisseria which are present in the specimen will grow and form colonies which can then be detected by visual inspection.
Various types of culture media have been utilized in the prior art. For example, Simpson et al, U.S. Pat. No. 4,039,387, relates to a growth medium for distinguishing between Neisseria gonorrhoeae and Neisseria meningitidis.
The particular medium most widely used in the art at the time of this application is known as the Thayer-Martin medium. This medium was disclosed in 1966 by Messrs. Thayer and Martin in Public Health Rep. 81: 559-562. It has been observed that the Thayer-Martin medium is less than 100 percent effective in isolating N. gonorrhoeae, isolation rates ranging from about 40 percent to about 90 percent. This means that only about 40 to 90 percent of the specimens known to contain the bacteria will show growth. In a clinical situation, this means that from 10 percent to 50 percent of all individuals infected with the disease will remain undetected after observation of the first culture.
In view of the increasing incidence of the disease to epidemic proportions and further in view of the very large numbers of cases, both reported and unreported, the difference in detection rates is very important. It is perhaps even more important with respect to the other pathogenic Neisseria, N. meningitidis, since this bacteria causes a potentially fatal disease the prompt and accurate detection of which is, in many cases, critical.
It is known in the prior art to use cations such as ferric ions or aluminum ions in a medium for the detection of pathogenic Neisseria in order to increase the growth of the bacteria. For example, in U.S. Pat. No. 3,936,355, Lawson discloses the use of ferric nitrate in a culture medium for supporting the growth of certain types of microorganisms, including Neisseria gonorrhoeae and Neisseria meningitidis. The standard practice in the prior art has been to add iron to the culture medium in the form of ferric nitrate.
Kellogg et al investigated Neisseria gonorrhoeae and in their paper, Neisseria Gonorrhoeae, J. Bacteriology, September 1968, 596, identified four distinct colonial forms of gonococcus, T1, T2, T3 and T4. The former two types were shown to be virulent to man and the latter two to be relatively avirulent. At page 600, Kellogg et al observed the importance of including ferric ions in the culture medium to promote growth of the bacteria. Kellogg et al point out that the types of anions accompanying the ferric ions had no effect on the results, and that while glucose alone was ineffective to promote increased growth, use of glucose with ferric ions produced "an additive effect". In FIG. 4, at Page 600 of their paper, Kellogg et al plotted the growth stimulation in colony diameter with the inclusion of ferric ions, with the inclusion of glucose, and with the inclusion of a mixture of glucose and ferric ions wherein the ratio of glucose to ferric ions was 1.0. These results indicate that the increase in colony diameter in the medium is only slightly greater when a glucose/ferric combination is utilized compared to the use of ferric ions alone. Further, Kellogg et al point out at Page 600 of their paper that "a ratio of glucose to ferric ions of less than one depressed the colony size to a level intermediate between that obtained with either additive alone."
In their paper entitled "Pathogenesis and Immunology of Experimental Gonococcal Infection: Role of Iron in Virulence," (1975, Infect. Immun. 12: 1313-1318), applicants disclosed the creation of an experimental animal model, chicken embryos, with findings that the colonial types previously identified as virulent (T1 and T2) killed the animals, and that the forms identified as relatively nonvirulent (T3 and T4) did not. Applicants further disclosed in that paper that the virulence of the T3 and T4 types to chicken embryos is enhanced by adding iron in various forms, including in the form of an iron-dextran complex (specifically, Imferon).
The present invention of applicants was first disclosed in their paper entitled "Imferon Agar: Improved Medium for Isolation of Pathogenic Neisseria," J. Clinical Microbiology, Volume 6, Number 3, September 1977, pp. 293-297.
It has been estimated that there are some three to four million cases of gonorrhea each year in the United States, most of which go unreported. Improvement in the rate of detection of gonorrhea from a first culture would represent a significant advancement in the art. Such improvement can be obtained by devising a method and composition for effectively increasing the colony size of the bacteria Neisseria gonorrhoeae so that the presence of the bacteria may be readily observed within a short period of time. Similar advantages would also result if an improved medium could be developed for the detection of the other pathogenic Neisseria, Neisseria meningitidis.
This invention seeks to develop such methods and such a medium to improve the speed and rate of isolation of Neisseria gonorrhoeae and Neisseria Meningitidis, so that their colonies are much larger in size and will appear after a much shorter incubation period.
SUMMARY OF THE INVENTION
This invention provides growth media for the rapid detection of pathogenic Neisseria, which incorporate an iron-dextran complex as the source of iron in standard gonococcal and meningicoccal-specific culture media.
Further, this invention provides methods for the rapid detection of pathogenic Neisseria, which include the step of incorporating into a gonococcal and meningicoccal-specific medium as the source of iron, an iron-dextran complex.
DETAILED DESCRIPTION OF PREFERRED EMBODIMENTS
Neisseria gonorrhoeae and Neisseria meningitidis are the two pathogenic members of the Neisseria family. In accordance with the preferred embodiments of this invention, improved media and methods for the isolation and rapid detection of these pathogenic Neisseria are provided.
According to the methods of this invention, a standard gonococcal and meningicoccal-specific medium is provided, which medium will stimulate the growth of the bacteria as measured by increased colony diameter. A suitable standard gonococcal and meningicoccal-specific medium is that commonly used in the art known as the GC medium base which may be obtained from Difco Laboratories, Detroit, Mich. GC base is a standard culture medium which is specifically designed for growing gonococcal and meinigicoccal bacteria.
To this standard medium is added an operable amount of an iron-dextran complex. An operable amount of iron-dextran complex is that sufficient to give a final concentration of at least about 5 micrograms per milliliter, and preferably approximately 20 micrograms of iron per milliliter of medium. Applicants have found that an operable amount is at least about 0.01 percent by volume of the iron-dextran complex.
An example of the iron-dextran composition which is useful in connection with the invention is the product marketed by Richardson-Merrill Inc. under the trademark Imferon, which product is available, for example, from Lakeside Laboratories, Inc., Milwaukee, Wis. Where the product Imferon is utilized, the amount of Imferon preferred for use by applicants is approximately 0.04 volume percent.
To the standard base containing the iron-dextran complex may be added a nutritional supplement such as the so-called Kellogg supplement which is also commonly available in the industry, in the amount of approximately 1 percent by volume. A selective antibiotic is also preferably added to the medium to prevent the growth of other bacteria while still permitting the growth of the pathogenic Neisseria. Such an antibiotic is vancomycin-colistin-nystatin (V-C-N).
The culture medium as described above is mixed in agar, which is a gelatinous colloidal extractive of a red alga commonly used in culture media.
To the iron-dextran containing medium thus provided, and further in accordance with the methods of this invention, a suitable amount of said medium, e.g. about 25 milliliters, is retained in a container such as a plastic Petri dish and inoculated with a culture containing a pathogenic Neisseria. This may be done in any suitable manner well-known in the art, for example by the streaked cotton swab method. The plates are then incubated, preferably at 37° C. in 10 percent carbon dioxide for a period of time of at least about 20 hours.
Following incubation, the growth of bacteria is observed to ascertain the presence of pathogenic Neisseria.
Applicants have found from both laboratory and clinical experimentation that the methods and media disclosed above yield superior results when compared with the methods and media of the prior art. Some of the experiments of applicants are reported in the examples which follow.
In Examples I through IV, applicants demonstrate the effect of increasing amounts of Imferon on colony growth of pathogenic Neisseria.
EXAMPLE I
A control medium was prepared as follows:
A GC medium base from Difco Laboratories of Detroit, Mich., was provided. To this GC medium base one percent of a Kellogg supplement [which is described at J. Am. Vener. Dis. Assoc. 1:14-19] was added omitting the ferric nitrate, and one percent of the selective antibiotic vancomycin, colistin and nystatin (V-C-N), obtained from Baltimore Biological Laboratory of Cockeysville, Md., was also included in the medium.
About 25 milliliters of the media thus prepared were placed in a plastic Petri dish.
To the medium thus prepared, three samples of pathogenic Neisseria were added, the first being Neisseria gonorrhoeae, type T1, the second being Neisseria gonorrhoeae, type T3, and the third being Neisseria meningitidis. The samples of Neisseria gonorrhoeae were strain F62 provided by D. S. Kellogg, Jr., Center for Disease Control, Atlanta, Ga. The Neisseria meningitidis was strain B-11 obtained from H. Schneider, Walter Reed Army Institute for Research, Washington, D.C.
Equal volume droplets of dilutions of suspensions of gonococci and meningicocci were plated by the streaked cotton swab technique on the culture media media being compared. Plates were incubated at 37° C. in 10 percent carbon dioxide. After 20 hours of incubation, the numbers of colonies and their average size were determined by using a dissecting microscope fitted with an optical reticle. The results of these tests are reported in the first column of Table 1.
EXAMPLE II
Example I was repeated, except that 4 micrograms of iron in the form of Imferon were added to the control medium.
The three bacteria mentioned above were added in the same manner, and incubated under the same conditions and for the same period of time.
The results of these tests are reported in the second column of Table 1, and indicate significant increases in colony size for all three bacteria tested.
EXAMPLE III
Example I was repeated, except that 8 micrograms per milliliter of iron in the form of Imferon were added.
The three bacteria of Example I were tested in the same manner as indicated in that example.
The results of these tests are reported in the third column of Table 1, and show that even greater increases in colony size were obtained in all instances.
EXAMPLE IV
Example I was repeated, except that 20 micrograms per milliliter of iron in the form of Imferon were added to the culture medium.
The three bacteria of Example I were added and incubated in the same manner as specified in that example.
The results of these tests are shown in Column 4 of Table 1, and indicate significant increases in colony size for all three bacteria. The total increase in colony size in Example IV, as compared to Example I, was more than fivefold in the case of Neisseria meningitidis B-11, was nearly fourfold in the case of Neisseria gonorrhoeae T3, and was some threefold in the case of Neisseria gonorrhoeae T1.
TABLE 1______________________________________Amount of iron in the form of Imferonin medium of Examples I-IV vs.average colony diameter in millimeters 0 4 μg 8 μg 20 μg______________________________________ N. meningitidis B-11 6 11 16 31N. gonorrhoeae T3 4 6 8 15N. gonorrhoeae T1 2 3 4 6 Ex. Ex. Ex. Ex. I II III IV______________________________________
Applicants also conducted tests to compare the change in colony size of Neisseria meningitidis B-11, and Neisseria gonorrhoeae F62 T1 and T3, between growth media containing various concentrations of Imferon with various other types of media utilized in the prior art. The various media used in these experiments are described below in Examples V through X, with the results of the tests on these media described thereafter.
EXAMPLE V
A culture medium was prepared consisting of a GC medium base plus 1 percent Kellogg supplement.
EXAMPLE VI
A medium comprising GC medium plus 1 percent IsoVitalX, which was obtained from Baltimore Biological Laboratory of Cockeysville, Md., was prepared.
EXAMPLE VII
A Thayer-Martin medium was prepared consisting of GC medium base, 1 percent hemoglobin, and 1 percent IsoVitalX.
EXAMPLE VIII
A medium identical to that used in Example II was prepared.
EXAMPLE IX
A medium identical to that used in Example III was prepared.
EXAMPLE X
A medium identical to that used in Example IV was prepared.
To each of the media prepared in Examples V through X, an identical amount of V-C-N was added.
Each of the media of Examples V through X was simultaneously inoculated with Neisseria meningitidis B-11 in the manner specified in Example I, and allowed to incubate under the conditions and for the time specified in that example.
The results of these tests are shown in FIG. 2 of our article entitled "Imferon Agar: Improved Medium for Isolation of Pathogenic Neisseria," published in the Journal of Clinical Microbiology, Volume 6, Number 3, at Page 295, September, 1977.
The results indicate that the colony size for Examples VIII, IX and X were significantly larger than those of Examples V, VI and VII, with the size of the colonies in Example X being significantly larger than those in Example IX, and the size of the colonies in Example IX being significantly larger than those in Example VIII.
Media prepared in accordance with Examples V through X were also inoculated with Neisseria gonorrhoeae F62 T1 and T3, and incubated under the same conditions and for the same time as indicated in Example I. The results of these tests are shown in FIG. 3, at Page 296 of the above-mentioned article in the Journal of Clinical Microbiology. These tests also demonstrated the improved results obtained with the addition of Imferon.
Applicants also compared their results obtained by the use of Imferon with the use of corresponding amounts of ferric nitrate. The results of these experiments are reported in Examples XI and XII below.
EXAMPLE XI
A medium identical to that of Example I was prepared and separated into four parts. To the second part, 5 micrograms of iron in the form of Imferon were added; to the third part, 10 micrograms of iron in the form of Imferon were added; to the fourth part, 20 micrograms of iron in the form of Imferon were added.
In the manner of Example I, a sample of Neisseria gonorrhoeae F62 T1 was added to each sample and incubated in the manner specified in Example I.
The results are reported in the second horizontal column of Table 2, and show that a consistent increase in average colony diameter was realized with the increasing concentration of Imferon.
EXAMPLE XII
A medium was prepared in the manner of Example I. The medium was separated into four equal parts, and to the second part, 5 micrograms of iron in the form of ferric nitrate were added; to the third part, 10 micrograms of iron in the form of ferric nitrate were added; to the fourth part, 20 micrograms of iron in the form of ferric nitrate were added.
In the manner of Example I, equal portions of Neisseria gonorrhoeae F62 T1 were inoculated into each of the four samples. After incubation for the period and in the manner suggested by Example I, the average colony size in each of the samples was measured. The results are reported in the second horizontal column of Table 2. The results indicate that, while colony size increased significantly with small concentrations of ferric nitrate, increasing the concentration of ferric nitrate beyond 5 micrograms of iron per milliliter did not result in further increase in colony size. In fact, maximum colony size was realized at 5 micrograms of iron in the form of ferric nitrate.
TABLE 2______________________________________Amount of added iron vs.average colony diameter in millimeters 0 5 μg 10 μg 20 μg______________________________________Imferon 2.2 2.9 4.2 6Ex. XIferric nitrate 2.2 4.1 3.9 3.9Ex. XII______________________________________
Further laboratory experiments were performed utilizing various combinations of ferric nitrate and dextrans T10, T70 and T500. The dextrans alone were found to be somewhat stimulatory for gonococci and meningicocci, and in combination with ferric nitrate, colony sizes approached those obtained with Imferon. However, the use of Imferon rather than a combination of iron and dextran was preferable since results were more consistent and predictable with Imferon.
Applicants also performed clinical tests, the results of which are reported in Example XIII below.
EXAMPLE XIII
In a clinical test performed from subjects attending the Dallas Public Health Department Venereal Disease Clinic, a total of 406 cultures were taken from 389 patients, comprising 151 females and 238 males. The 406 cultures were inoculated in a Imferon agar media prepared in accordance with Example IV, and in a Thayer-Martin medium prepared in accordance with Example VII.
Incubation was in the manner indicated in Example I, except that the plates were read after overnight incubation (16 to 24 hours) in the case of the Imferon medium, and after 40 to 48 hours in the case of the Thayer-Martin medium.
The results of these clinical tests indicated that 182 positive cultures were detected within 24 hours with Imferon agar, and no additional positive cultures resulted when the Imferon agar was incubated for an additional 24 hours.
On the other hand, only 164 positive tests were detected with Thayer-Martin medium despite an additional 24 hours of incubation. The results of this test are reported more fully at Pages 294-295 of the article in Journal of Clinical Microbiology mentioned above.
The results of these tests, both laboratory and clinical, confirm the ability of a growth medium which includes an iron-dextran complex to enhance the growth and to provide for more rapid identification of pathogenic Neisseria. Colonies appear readily visible after overnight incubation of Neisseria gonorrhoeae even when the inocula are small, and further incubation does not result in any increase in the number of positive cultures. In experiments by applicants, isolation rates were significantly higher, especially in clinical trials. Based on these observations, a culture medium including an iron-dextran complex, and specifically Imferon agar, represents a significant improvement over previously described and widely used methods and media for the isolation of pathogenic Neisseria.
While the invention has been described in terms of preferred embodiments constituting the best mode known to the applicants at the time of this application, various changes may be made in the invention without departing from the scope thereof, which is defined by the following claims:
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A microbial growth medium for the isolation and rapid detection of Neisseria gonorrhoeae and Neisseria meningitidis, having incorporated therein an iron-dextran complex in a quantity sufficient to stimulate maximum colony growth.
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CROSS REFERENCES TO RELATED APPLICATIONS
[0001] The present application is a continuation of U.S. application Ser. No. 13/560,708, filed on Jul. 27, 2012, which claims priority to Japanese Priority Patent Application JP 2011-169867 filed in the Japan Patent Office on Aug. 3, 2011, the entire content of each of which is hereby incorporated by reference.
BACKGROUND
[0002] The present disclosure relates to a storage element that includes a storage layer storing a magnetization state of a ferromagnetic layer as information and a magnetization fixing layer in which the direction of magnetization is fixed and the direction of the magnetization of the storage layer is changed by causing a current to flow, and a storage device including the storage element.
[0003] With rapid development of various information apparatuses such as mobile terminals and large-capacity servers, new high performance features such as high integration, high speed, and low power consumption have been studied on elements such as memories or logic circuits included in various information apparatuses. In particular, semiconductor non-volatile memories have been highly advanced and flash memories such as high-capacity file memories have been proliferated as hard disk drives. On the other hand, development of ferroelectric random access memories (FeRAMs), magnetic random access memories (MRAMs), phase-change random access memories (PCRAMs), and the like is in progress to develop these memories to code storages or working memories and to substitute the currently available NOR flash memories or DRAMs. Moreover, some of the memories have already been put to practical use.
[0004] Of the memories, MRAMs are capable of rewriting data rapidly and almost infinitely (more than 10 15 times) because data is stored according to a direction of magnetization of a magnetic body, and have already been used in fields of industry automation, airplanes, or the like. MRAMs are expected to be developed into code storages or working memories in the future in terms of a high speed operation and reliability. In reality, difficulties of low power consumption and large capacity have become a problem. This problem is an inherent problem with a recording principle of MRAMs, that is, a method of causing a current to flow in two kinds of address lines (a word line and a bit line) substantially perpendicular to one another and recording information by reversing the magnetization of a magnetic layer of a magnetic storage element at an intersection of the address lines using a current magnetic field generated from each address line, that is, reversing the magnetization using the current magnetic field generated from each address line.
[0005] As one of the solutions to this problem, recording types performed without dependency on the current magnetic field, that is, magnetization reversing types, have been examined. Of these types, studies on spin torque magnetization reversal have actively been made (for example, see Japanese Unexamined Patent Application Publication No. 2003-17782, U.S. Pat. No. 6,256,223, Japanese Unexamined Patent Application Publication No. 2008-227388, PHYs. Rev.B, 54.9353 (1996), and J. Magn. Mat., 159, L1 (1996)).
[0006] The spin torque magnetization reversal type storage elements are configured by a magnetic tunnel junction (MTJ), as in MRAMs, in many cases. In such a configuration, a free magnetic layer is reversed when a current with a value equal to or greater than a given threshold is caused to flow by applying a torque (which is called a spin transfer torque) to a magnetic layer when spin-polarized electrons passing through the magnetic layer fixed in a given direction enter another free magnetic layer (in which a direction is not fixed). Rewriting “0/1” is performed by changing the polarity of the current.
[0007] An absolute value of the current used to reverse the magnetic layer is 1 mA or less in an element with a scale of about 0.1 μm. Further, scaling can be performed to decrease the current value in proportion to an element volume. Furthermore, there is an advantage of simplifying a cell structure, since a recording current magnetic field generation word line, which is necessary in MRAMs, is not necessary.
[0008] Hereinafter, an MRAM using spin torque magnetization reversal is referred to as a spin torque-magnetic random access memory (ST-MRAM). The spin torque magnetization reversal is also referred to as spin injection magnetization reversal. An ST-RAM is highly expected to be realized as a non-volatile memory that has the advantages of low power consumption and large capacity in addition to the advantages of an MRAM in which data is rewritten rapidly and almost infinitely.
SUMMARY
[0009] In MRAMs, a writing line (a word line or a bit line) is provided separately from a storage element and information is written (recorded) using a current magnetic field generated by causing a current to flow in the writing line. Therefore, a sufficient amount of current necessary for writing the information can flow in the writing line.
[0010] On the other hand, in an ST-MRAM, it is necessary to reverse the direction of the magnetization of the storage layer by performing the spin torque magnetization reversal by the current flowing in the storage element. Since information is written (recorded) by causing a current to flow directly to the storage element, the storage device includes a storage element and a selection transistor connected to one another to select a storage device writing information. In this case, the current flowing in the storage element is restricted by the magnitude of the current (the saturated current of the selection transistor) that can flow in the selection transistor.
[0011] Further, since an ST-MRAM is a non-voltage memory, it is necessary to stably store information written using the current. That is, it is necessary to ensure stability (thermal stability) against thermal fluctuation of the magnetization of the storage layer.
[0012] When the thermal stability of the storage layer is not ensured, the reversed direction of the magnetization may be reversed again due to heat (temperature in an operation environment). Therefore, a writing error may be caused.
[0013] In the storage element of the ST-MRAM, the advantage of the scaling, that is, the advantage of reducing the volume of the storage layer, can be obtained compared to an MRAM according to the related art, as described above.
[0014] However, when the volume of the storage layer is reduced, the thermal stability has a tendency to deteriorate under the same conditions of the other characteristics.
[0015] In general, when the volume of the storage element increases, the thermal stability and the writing current are known to increase. Conversely, when the volume of the storage element decreases, the thermal stability and the writing current are known to decrease.
[0016] It is desirable to provide a storage element capable of ensuring thermal stability as much as possible without an increase in a wiring current and a storage device including the storage element.
[0017] According to an embodiment of the present disclosure, an information storage element comprises a first layer having a transverse length that is approximately 45 nm or less so as to be capable of storing information according to a magnetization state of a magnetic material, the magnetization state being configured to be changed by a current, an insulation layer coupled to the first layer, the insulation layer including a non-magnetic material, and a second layer coupled to the insulation layer opposite the first layer, the second layer including a fixed magnetization so as to be capable of serving as a reference of the first layer.
[0018] According to another embodiment of the present disclosure, an information storage element comprises a first layer having an area that is approximately 1,600 nm 2 or less so as to be capable of storing information according to a magnetization state of a magnetic material, the magnetization state being configured to be changed by a current, an insulation layer coupled to the first layer, the insulation layer including a non-magnetic material, and a second layer coupled to the insulation layer opposite the first layer, the second layer including a fixed magnetization so as to be capable of serving as a reference of the first layer.
[0019] According to yet another embodiment of the present disclosure, an information storage element comprises a first layer having a volume that is approximately 2,390 nm 3 or less so as to be capable of storing information according to a magnetization state of a magnetic material, the magnetization state being configured to be changed by a current, an insulation layer coupled to the first layer, the insulation layer including a non-magnetic material, and a second layer coupled to the insulation layer opposite the first layer, the second layer including a fixed magnetization so as to be capable of serving as a reference of the first layer.
[0020] In the configuration of the storage device according to the embodiment of the present disclosure, a storage device comprises a storage element that holds information according to a magnetization state of a magnetic material, and two kinds of lines that intersect one another, the storage element including a first layer having a transverse length that is approximately 45 nm or less, an insulation layer coupled to the first layer, the insulation layer including a non-magnetic material, and a second layer coupled to the insulation layer opposite the first layer, the second layer including a fixed magnetization so as to be capable of serving as a reference of the first layer. The storage element is interposed between the two kinds of lines.
[0021] In the configuration of the storage device according to another embodiment of the present disclosure, a storage device comprises a storage element that holds information according to a magnetization state of a magnetic body, and two kinds of lines that intersect one another, the storage element including a first layer having an area that is approximately 1,600 nm 2 or less, an insulation layer coupled to the first layer, the insulation layer including a non-magnetic material, and a second layer coupled to the insulation layer opposite the first layer, the second layer including a fixed magnetization so as to be capable of serving as a reference of the first layer. The storage element is interposed between the two kinds of lines.
[0022] Since the thermal stability of the storage layer can be sufficiently maintained, the information recorded in the storage element can be stably held. Further, it is possible to miniaturize the storage device, improve reliability, and realize the low power consumption.
[0023] According to the embodiments of the present disclosure, the thermal stability can be efficiently improved for a writing current in an ST-MRAM having vertical magnetic anisotropy. Therefore, it is possible to realize the storage element ensuring the thermal stability as an information holding capability and thus having excellent characteristic balance such as power consumption.
[0024] Thus, an operation error can be prevented and an operation margin of the storage element can be sufficiently obtained.
[0025] Accordingly, it is possible to realize the memory operating stably and having high reliability.
[0026] Further, the writing current can be reduced, and thus the power consumption can be reduced when information is written on the storage element. Accordingly, the entire power consumption of the storage device can be reduced.
[0027] Additional features and advantages are described herein, and will be apparent from the following Detailed Description and the figures.
BRIEF DESCRIPTION OF THE FIGURES
[0028] FIG. 1 is a schematic diagram (perspective view) illustrating a storage device (memory device) according to an embodiment;
[0029] FIG. 2 is a sectional view illustrating the storage device according to the embodiment;
[0030] FIG. 3 is a sectional view illustrating a storage element according to the embodiment;
[0031] FIG. 4 is a diagram illustrating a cross-sectional configuration of samples of the storage element used in an experiment;
[0032] FIGS. 5A and 5B are diagrams illustrating dependencies of the size of a storage layer with respect to Ic and Δ obtained from an experiment of Sample 1;
[0033] FIG. 6 is a diagram illustrating a size dependency (indicated by ▴ in the drawing) of the storage layer with respect to Δ obtained from the experiment of Sample 1 and a size dependency (indicated by ♦ in the drawing) of the storage layer with respect to Δ calculated based on saturated magnetization Ms and an anisotropy magnetic field Hk obtained through measurement of VSM;
[0034] FIGS. 7A and 7B are diagrams illustrating dependencies of the size of a storage layer with respect to Ic and Δ obtained from an experiment of Sample 2; and
[0035] FIG. 8 is a diagram illustrating a size dependency (indicated by ▴ in the drawing) of the storage layer with respect to Δ obtained from the experiment of Sample 2 and a size dependency (indicated by ♦ in the drawing) of the storage layer with respect to Δ calculated based on saturated magnetization Ms and an anisotropy magnetic field Hk obtained through measurement of VSM.
DETAILED DESCRIPTION
[0036] Hereinafter, preferred embodiments of the present disclosure will be described in detail with reference to the appended drawings. Note that, in this specification and the appended drawings, structural elements that have substantially the same function and structure are denoted with the same reference numerals, and repeated explanation of these structural elements is omitted.
[0037] Hereinafter, an embodiment of the present disclosure will be described in the following order.
[0038] 1. Storage Element according to Embodiment
[0039] 2. Configuration of Storage Device according to Embodiment
[0040] 3. Specific Configuration according to Embodiment
[0041] 4. Experiment according to Embodiment
1. Storage Element According to Embodiment
[0042] First, a storage element according to an embodiment of the present disclosure will be described.
[0043] In the embodiment of the present disclosure, information is recorded by reversing the direction of magnetization of a storage layer of the storage element through the above-described spin torque magnetization reversal.
[0044] The storage layer is configured by a magnetic body including a ferromagnetic layer and information is held according to a magnetization state (the direction of magnetization).
[0045] For example, a storage element 3 has a layer configuration shown in FIG. 3 . The storage element 3 includes at least a storage layer 17 and a magnetization fixing layer 15 as two ferromagnetic layers and includes an insulation layer 16 as an intermediate layer between the two ferromagnetic layers.
[0046] The storage element 3 further includes a cap layer 18 on the storage layer 17 and includes an underlying layer 14 below the magnetization fixing layer 15 .
[0047] The storage layer 17 has magnetization perpendicular to a film surface. The direction of the magnetization is changed so as to correspond to the information.
[0048] The magnetization fixing layer 15 has magnetization perpendicular to a film surface serving as a reference of the information stored in the storage layer 17 .
[0049] The insulation layer 16 is a non-magnetic body and is formed between the storage layer 17 and the magnetization fixing layer 15 .
[0050] When spin-polarized electrons are injected in a lamination direction of the layer configuration of the storage layer 17 , the insulation layer 16 , and the magnetization fixing layer 15 , the direction of the magnetization of the storage layer 17 is changed and information is thus recorded on the storage layer 17 .
[0051] Hereinafter, spin torque magnetization reversal will be described simply.
[0052] Electrons have two kinds of spin angular momenta. Here, the electrons are defined as upward electrons and downward electrons. In the non-magnetic body, the upward and downward electrons are the same in number. In the ferromagnetic body, the upward and downward electrons are different in number. In the magnetization fixing layer 15 and the storage layer 17 , which are two ferromagnetic layers of the storage element 3 , a case in which electrons are moved from the magnetization fixing layer 15 to the storage layer 17 when the directions of magnetic moments are opposite to one another will be considered.
[0053] The magnetization fixing layer 15 is a fixing magnetic layer in which the direction of a magnetic moment is fixed to ensure high coercivity.
[0054] In the electrons passing through the magnetization fixing layer 15 , spin polarization occurs, that is, there is a difference in number between the upward and downward electrons. When the non-magnetic insulation layer 16 has a sufficient thickness, the electrons reach the other magnetic body, that is, the storage layer 17 , before the spin polarization of the electrons passing through the magnetization fixing layer 15 is alleviated and the electrons enter a non-polarized state (in which the upward and downward electrons are the same in umber) in a normal non-magnetic body.
[0055] In the storage layer 17 , since the sign of the degree of spin polarization is opposite, some of the electrons are reversed, that is, the direction of the spin angular momentum is changed to lower the energy of a system. At this time, since the entire angular momenta of the system have to be conserved, the reaction equivalent to the sum of the change in the angular momenta caused by the electrons of which the direction is changed is applied to the magnetic moment of the storage layer 17 .
[0056] When a current, that is, the number of electrons passing in a unit time, is small, the total number of electrons of which the direction is changed is also small. Therefore, a change in the angular momentum occurring in the magnetic moment of the storage layer 17 is also small. However, when the current increases, the angular momentum can be considerably changed in a unit time.
[0057] A time change of an angular momentum is a torque. When a torque is greater than a given threshold, the magnetic moment of the storage layer 17 starts a precession movement. The magnetic moment is stabilized after the magnetic moment rotates by 180 degrees by uniaxial anisotropy. That is, the magnetic moment is reversed from an opposite direction to the same direction.
[0058] When a current reversely flows in a direction in which electrons are sent from the storage layer 17 to the magnetization fixing layer 15 in a state of the same direction of the magnetization, a torque is applied in a case in which the electrons are reflected from the magnetization fixing layer 15 and the spin-reversed electrons enter the storage layer 17 . Then, the magnetic moment can be reversed in the opposite direction. At this time, the amount of current necessary to cause the reversal is greater compared to a case in which the magnetic moment is reversed from the opposite direction to the same direction.
[0059] It is difficult to intuitively understand the reversal of the magnetic moment from the same direction to the opposite direction, but the storage layer 17 may be considered to be reversed to conserve the entire angular momenta of a system without the reversal of the magnetic moment since the magnetization fixing layer 15 is fixed. Thus, “0/1” is recorded by causing a current corresponding to each polarity and equal to or greater than a given threshold to flow in the direction from the magnetization fixing layer 15 to the storage layer 17 or in the opposite direction.
[0060] Information is read using a magnetic resistive effect, as in an MRAM according to the related art. That is, a current flows in a direction perpendicular to a film surface, as in the recording case described above. The change phenomenon of electric resistance of an element is used depending on whether the direction of the magnetic moment of the storage layer 17 is the same as or opposite to the direction of the magnetic moment of the magnetization fixing layer 15 .
[0061] A metal or insulation material may be used as the material of the insulation layer 16 formed between the magnetization fixing layer 15 and the storage layer 17 . When an insulation material is used as the material of the insulation layer 16 , a high reading signal (resistance change ratio) can be obtained and information can be recorded with a lower current. In this case, an element is referred to as a magnetic tunnel junction (MTJ) element.
[0062] When the direction of the magnetization of a magnetic layer is reversed through spin torque magnetization reversal, a threshold value Ic of a necessary current is different depending on whether a magnetization-easy axis of the magnetic layer is in an in-plane direction or a vertical direction.
[0063] The storage element according to the embodiment is a vertical magnetization type storage element. A reversal current used to reverse the direction of the magnetization of the magnetic layer is assumed to be Ic_para in an in-plane magnetization type storage element according to the related art.
[0064] When the magnetization is reversed from the same direction to the opposite direction (where the same direction and the opposite direction are the directions of the magnetization of the storage layer considered using the direction of the magnetization of the magnetization fixing layer as a reference), “Ic_para=(A·α·Ms·V/g(0)/P)(Hk+2πMs)” is satisfied.
[0065] When the magnetization is reversed from the opposite direction to the same direction), “Ic_para=−(A·α·Ms·V/g(π)/P)(Hk+2πMs)” is satisfied (which is referred to as Equation (1)).
[0066] On the other hand, a reversal current of the vertical magnetization type storage element is assumed to be Ic_perp. When the magnetization is reversed from the same direction to the opposite direction, “Ic_perp=(A·α·Ms·V/g(0)/P)(Hk−4πMs)” is satisfied.
[0067] When the magnetization is reversed from the opposite direction to the same direction, “Ic_perp=−(A·α·Ms·V/g(π)/P)(Hk−4πMs)” is satisfied (which is referred to as Equation (2)).
[0068] In the equations, A denotes a constant, α denotes a damping constant, Ms denotes saturated magnetization, V denotes an element volume, P denotes spin polarizability, g(0) and g(π) denote coefficients corresponding to efficiency of a spin torque applied to a magnetic layer in the same direction and the opposite direction, respectively, and Hk denotes magnetic anisotropy (see Nature Materials., 5, 210 (2006)).
[0069] When the vertical magnetization type storage element (Hk−4πMs) is compared to the in-plane magnetization type storage element (Hk+2πMs) in the above-mentioned equations, the vertical magnetization type storage element can be understood to be suitable by a low recording current.
[0070] In this embodiment, the storage element 3 is configured to include a magnetic layer (the storage layer 17 ) in which information can be held according to a magnetization state and the magnetization fixing layer 15 in which the direction of the magnetization is fixed.
[0071] To function as a storage device, written information has to be held. The value of an index Δ (=KV/k B T) of thermal stability is used as the index of the capability of holding information. Here, Δ is expressed by Equation (3) below.
[0000] Δ= K·V/k B ·T=Ms·V·Hk ·(½ k B ·T ) Equation (3)
[0072] In this equation, Hk is an effective anisotropy field, k B is the Boltzmann's constant, T is temperature, Ms is a saturated magnetization amount, V is the volume of the storage layer 17 , and K is anisotropic energy.
[0073] The effective anisotropy field Hk receives the influence of magnetic anisotropy such as shape magnetic anisotropy, induced magnetic anisotropy, or crystal magnetic anisotropy. When a single-section simultaneous rotation model is supposed, the effective anisotropy is equal to coercivity.
[0074] Further, when the threshold value Ic is expressed in relation to Δ above, Equation (4) below is established.
[0000]
[
Expression
1
]
I
C
=
(
4
ek
B
T
ℏ
)
(
αΔ
η
)
Equation
(
4
)
[0075] In this equation, e is an element charge, k B is the Boltzmann's constant, T is temperature, Ms is a saturated magnetization amount, a is a Gilbert damping constant, H bar is the Flank's constant, and η is spin injection efficiency.
[0076] When the values of Hk, Ms, α, and η are determined according to Equation (3) and Equation (4), Δ and Ic are proportional to the volume V of the recording layer. That is, when the volume V of the recording layer increases, Δ and Ic increase. Conversely, when the volume V of the storage layer decreases, Δ and Ic decrease. This principle can be understood from the above-mentioned theoretical equation.
[0077] However, in the actual storage layer, it has been found that an increasing rate of Δ and Ic with respect to the volume of the storage layer is changed when the volume of the storage layer is equal to or greater than a given size.
[0078] According to this relation, when the volume of the storage layer is equal to or greater than the given size, only Ic increases without an increase in Δ in spite of the fact that the volume of the storage layer increases over the given size. This means that a ratio between Δ and Ic decreases when the volume of the storage layer is greater than a given size of the storage layer. Therefore, it is difficult to establish an effective existence condition of the ST-MRAM as a non-volatile memory, that is, compatibility between low-current information recording and high thermal stability of recorded information.
[0079] Accordingly, it is important to balance the value of the index Δ of the thermal stability and the threshold value Ic.
[0080] In many cases, the value of the index Δ of the thermal stability and the threshold value Ic have a tradeoff relation. Therefore, the compatibility is a task of maintaining the memory characteristics.
[0081] With regard to the threshold value of the current used to change the magnetization state of the storage layer 17 , in fact, the thickness of the storage layer 17 is, for example, 2 nm. In a substantially elliptical TMR element with a planar pattern of 100 nm×150 nm, the threshold value +Ic of a positive side is equal to +0.5 mA and the threshold value −Ic of a negative side is equal to −0.3 mA. At this time, a current density is about 3.5×10 6 A/cm 2 . These values are identical to those in Equation (1).
[0082] However, in a normal MRAM in which magnetization is reversed through a current magnetic field, a writing current of a few mA or more is necessary.
[0083] Accordingly, in the ST-MRAM, the threshold value of the writing current is sufficiently small, as described above. Therefore, the threshold value can be understood to be effective for reducing the power consumption of an integrated circuit.
[0084] Further, since a wiring line necessary in the normal MRAM to generate a current magnetic field is not necessary, the advantage of the degree of integration can be obtained compared to the normal MRAM.
[0085] When the spin torque magnetization reversal is performed, information is written (recorded) by causing a current to flow directly to the storage element 3 . Therefore, the storage device includes the storage element 3 and a selection transistor connected to each other to select the storage element 3 that writes information.
[0086] In this case, the current flowing in the storage element 3 is restricted by the magnitude of the current (the saturated current of the selection transistor) that can flow in the selection transistor.
[0087] The vertical magnetization type storage element is preferably used to reduce the recording current, as described above. Further, since a vertical magnetization film can have magnetic anisotropy higher than an in-plane magnetization film, the large index Δ of the above-described thermal stability is preferably maintained.
[0088] Examples of a magnetic material with vertical anisotropy include alloys of rare-earths and transition metals (TbCoFe and the like), metal multilayer films (Cd/Pd multilayer films and the like), ordered alloys (FePt and the like), and materials using interfacial anisotropy (Co/MgO and the like) between an oxide and a magnetic metal. The alloys of rare-earths and transition metals are not desirable as the material of the ST-MRAM. This is because vertical magnetic anisotropy is lost when the alloys are diffused and crystallized by heating. The metal multilayer films are known to be diffused by heating and thus deteriorate in the vertical magnetic anisotropy and the vertical magnetic anisotropy is expressed when face-centered cubic (111) orientation is realized. Therefore, it is difficult to realize (001) orientation necessary in a high polarizability layer such as MgO or Fe, CoFe, CoFeB, or the like adjacent to MgO. Since L10 ordered alloys are stable at high temperatures and the vertical magnetic anisotropy is expressed at the (001) orientation time, the above-mentioned problems do not occur. However, since it is necessary to arrange atoms orderly by performing heating at the sufficiently high temperature of 500° C. or more during manufacturing or by performing heating at the sufficiently high temperature of 500° C. or more after the manufacturing, there is a probability that undesirable diffusion may occur in another portion of a laminated layer such as a tunnel barrier or interface roughness may increase.
[0089] However, the above-mentioned problems rarely occur for a material using interface magnetic anisotropy, that is, a material in which a Co-based material or a Fe-based material is laminated on MgO serving as a tunnel barrier. Therefore, the material is expected as the material of the storage layer of the ST-MRAM.
[0090] In this embodiment, a material having Co—Fe—B as a base is used as the material of the storage layer 17 . Several elements of Ti, V, Nb, Zr, Ta, Hf, Y, and the like may be added as non-magnetic metals to Co—Fe—B.
[0091] Further, in consideration of the saturated current value of the selection transistor, an MTJ element is configured using a tunnel insulation layer that includes an insulator as the non-magnetic insulation layer 16 between the storage layer 17 and the magnetization fixing layer 15 .
[0092] When the MTJ element is configured using the tunnel insulation layer, a magnetoresistance ratio (MR ratio) can be increased compared to a case in which a grant magnetoresistive effect (GMR) element is configured using a non-magnetic conductive layer. Therefore, the intensity of a reading signal can be increased.
[0093] In particular, the magnetoresistance ratio (MR ratio) can be increased using magnesium oxide (MgO) as the material of the insulation layer 16 serving as a tunnel insulation layer.
[0094] In general, a spin transfer efficiency depends on the MR ratio. The larger the MR ratio is, the more the spin transfer efficiency is improved. Therefore, a magnetization reversal current density can be reduced.
[0095] Accordingly, by using the magnesium oxide as the material of the tunnel insulation layer and the storage layer 17 , it is possible to reduce the threshold value of the writing current through the spin torque magnetization reversal. Therefore, information can be written (recorded) with a lower current. Further, the intensity of the reading signal can be increased.
[0096] Thus, since the MR ratio (TMR ratio) can be ensured and the threshold value of the writing current can be reduced through the spin torque magnetization reversal, information can be written (recorded) with a lower current. Further, the intensity of the reading signal can be increased.
[0097] When the tunnel insulation layer is formed of a magnesium oxide (MgO) film, the MgO film is crystallized. Therefore, crystal orientation is more preferably maintained in the 001 direction.
[0098] In this embodiment, the insulation layer 16 (the tunnel insulation layer) formed between the storage layer 17 and the magnetization fixing layer 15 is formed of not only magnesium oxide but also various insulators such as aluminum oxide, aluminum nitride, SiO 2 , Bi 2 O 3 , MgF 2 , CaF, SrTiO 2 , AlLaO 3 , and Al—N—O, a dielectric material, a semiconductor, or the like.
[0099] It is necessary to control the area resistive value of the insulation layer 16 serving as the tunnel insulation layer such that the area resistive value is equal to or less than about tens of Ωμm 2 in terms of obtainment of the current density necessary for reversing the direction of the magnetization of the storage layer 17 through the spin torque magnetization reversal.
[0100] In the tunnel insulation layer formed of a MgO film, the thickness of the MgO film should be set 1.5 nm or less, so that the area resistive value is in the above-described range.
[0101] In the ST-MRAM, 0 and 1 of information are determined by relative angles of magnetization M17 of the storage layer 17 and magnetization M15 of the magnetization fixing layer 15 .
[0102] The underlying layer 14 is formed below the magnetization fixing layer 15 and the cap layer 18 is formed on the storage layer 17 .
[0103] In this embodiment, the insulation layer 16 is formed as a magnesium oxide layer to increase the magnetoresistance ratio (MR ratio).
[0104] By increasing the MR ratio, it is possible to improve the spin injection effect and reduce the current density necessary for reversing the direction of the magnetization M17 of the storage layer 17 .
[0105] The storage device shown in FIG. 1 and including the storage element 3 shown in FIG. 2 has the advantage of applying a general semiconductor MOS forming process when a storage device is manufactured.
[0106] Accordingly, the storage device according to this embodiment is applicable to a general-purpose memory.
[0107] Since the size of the storage layer 17 can be less than a size in which the direction of the magnetization is simultaneously changed, the power consumption can be suppressed to be as small as possible. Thus, it is possible to realize the ST-MRAM using the thermal stability of the storage element 3 as much as possible. The specific size of the storage layer 17 of the storage element 3 is preferably equal to or less than a diameter of 45 nm.
[0108] Thus, it is possible to realize the storage element 3 that has excellent characteristic balance while ensuring the thermal stability as the information holding capability with low power consumption.
[0109] Since the operation margin of the storage element 3 can be sufficiently obtained by removing an operation error, the storage element 3 can stably operate. Accordingly, it is possible to realize a storage device operating stably and having high reliability.
[0110] Since the writing current is reduced, the power consumption can be reduced when information is written on the storage element 3 . Accordingly, the entire power consumption of the storage device can be reduced.
[0111] In this embodiment, a metal such as Ta is used in the cap layer 18 formed to be adjacent to the storage layer 17 .
[0112] An element other than Co and Fe may be added to the storage layer 17 according to the embodiment of the present disclosure.
[0113] When a different kind of element is added, it is possible to obtain an effect of an improvement in heat resistance by diffusion prevention, an increase in the magnetoresistive effect, an increase in a dielectric strength voltage obtained with flattening, or the like. Examples of the added element include B, C, N, O, F, Mg, Si, P, Ti, V, Cr, Mn, Ni, Cu, Ge, Nb, Mo, Ru, Rh, Pd, Ag, Ta, W, Ir, Pt, Au, Zr, Hf, Re, Os, or an alloy thereof.
[0114] In the configuration of the storage layer 17 according to the embodiment of the present disclosure, another ferromagnetic layer may be directly laminated. Further, a ferromagnetic layer and a soft magnetic layer may be laminated or a plurality of ferromagnetic layers may be laminated with a soft magnetic layer or a non-magnetic layer interposed therebetween. Even when these magnetic layers are laminated, the advantages of the embodiment of the present disclosure can be obtained.
[0115] In particular, when a plurality of ferromagnetic layers are laminated with a non-magnetic layer interposed therebetween, the strength of a mutual interaction between the ferromagnetic layers can be adjusted. Therefore, it is possible to obtain the advantage of preventing the magnetization reversal current from increasing in spite of the fact that the dimension of the storage element 3 is equal to or less than a submicron. In this case, Ru, Os, Re, Ir, Au, Ag, Cu, Al, Bi, Si, B, C, Cr, Ta, Pd, Pt, Zr, Hf, W, Mo, Nb, or an alloy thereof can be used as the material of the non-magnetic layer.
[0116] In the magnetization fixing layer 15 , the direction of the magnetization is fixed only from the ferromagnetic layer or using antiferromagnetic coupling of an antiferromagnetic layer and a ferromagnetic layer.
[0117] The magnetization fixing layer 15 may include a single-layered ferromagnetic layer or may have a lamination ferri-pin structure in which a plurality of ferromagnetic layers are laminated with a non-magnetic layer interposed therebetween.
[0118] As the material of the ferromagnetic layer of the magnetization fixing layer 15 having the lamination ferri-pin structure, Co, CoFe, CoFeB, or the like can be used. As the material of the non-magnetic layer, Ru, Re, Ir, Os, or the like can be used.
[0119] As the material of the antiferromagnetic layer, a FeMn alloy, a PtMn alloy, a PtCrMn alloy, a NiMn alloy, an IrMn alloy, or a magnetic body such as NiO, Fe 2 O 3 can be used.
[0120] Further, a non-magnetic element such as Ag, Cu, Au, Al, Si, Bi, Ta, B, C, O, N, Pd, Pt, Zr, Hf, Ir, W, Mo, Nb, or the like may be added to the magnetic body to adjust the magnetic characteristics or adjust various matter properties such as a crystal structure, a crystalline property, and substance stability.
[0121] The remaining configuration other than the configuration of the storage layer 17 and the magnetization fixing layer 15 of the storage element 3 is the same as the configuration of the storage element 3 that records information through spin torque magnetization reversal according to the related art.
[0122] In the configuration of the storage element 3 , the storage layer 17 may, of course, be disposed below the magnetization fixing layer 15 . In this case, the conductive oxide underlying layer undertakes the role of the conductive oxide cap layer.
[0123] As described above, the storage element 3 has the lamination configuration in which the cap layer 18 , the storage layer 17 , the insulation layer 16 , the magnetization fixing layer 15 , and the underlying layer 14 are laminated from the upper layer side. However, the storage element 3 of this embodiment may have a configuration in which the storage layer 17 is laminated below the magnetization fixing layer 15 .
[0124] Specifically, the storage element 3 may have a configuration in which the cap layer 18 , the magnetization fixing layer 15 , the insulation layer 16 , the storage layer 17 , and the underlying layer 14 are formed sequentially from the upper layer side.
2. Configuration of Storage Device According to Embodiment
[0125] Next, the configuration of the storage device according to the embodiment of the present disclosure will be described.
[0126] FIGS. 1 and 2 are schematic diagrams illustrating the storage device according to the embodiment. FIG. 1 is a perspective view and FIG. 2 is a sectional view.
[0127] As shown in FIG. 1 , the storage device according to the embodiment includes the storage element 3 configured by an ST-RAM capable of holding information by a magnetization state near an intersection of two kinds of addresses lines (for example, a word line and a bit line) perpendicular to one another.
[0128] That is, a drain region 8 , a source region 7 , and a gate electrode 1 that form a selection transistor configured to select each storage device are formed in a portion isolated by element isolation layers 2 of a semiconductor base substrate 10 such as a silicon substrate. In particular, the gate electrode 1 also serves as one address line (word line) extending in the front and rear directions in the drawing.
[0129] The drain region 8 is formed commonly in the selection transistors on the right and left of FIG. 1 . A wiring line 9 is connected to the drain region 8 .
[0130] The storage element 3 that is disposed above the source region 7 and includes the storage layer in which the direction of the magnetization is reversed through the spin torque magnetization reversal is disposed between the source region 7 and the bit line 6 extending in the right and left directions of FIG. 1 . The storage element 3 is configured by, for example, an MTJ element.
[0131] As shown in FIG. 2 , the storage element 3 includes two magnetic layers 15 and 17 . Of the two-layered magnetic layers 15 and 17 , the magnetization fixing layer 15 is configured as a layer in which the direction of magnetization M15 is fixed and the storage layer 17 is configured as a free magnetization layer in which the direction of magnetization M17 is changed.
[0132] The storage element 3 is connected to the bit line 6 and the source region 7 with upper and lower contact layers 4 interposed therebetween, respectively.
[0133] Thus, when a current flows in the storage element 3 in the vertical direction via two kinds of address lines 1 and 6 , the direction of the magnetization M17 of the storage layer 17 can be reversed through the spin torque magnetization reversal.
[0134] In such a storage device, it is necessary to write information using a current equal to or less than a saturated current of the selection transistor. Therefore, the saturated current of the selection transistor is known to decrease with miniaturization of the storage device. Accordingly, to miniaturize the storage device, it is necessary to improve the spin transfer efficiency and reduce the current flowing in the storage device 3 .
[0135] Further, to increase a reading signal, it is necessary to ensure a large magnetoresistance ratio. Therefore, it is effective to use the above-described MTJ structure, that is, the configuration of the storage element 3 in which the insulation layer is formed as the tunnel insulation layer (tunnel barrier layer) between the two layers of the magnetic layers 15 and 17 .
[0136] When the tunnel insulation layer is used as the insulation layer, the amount of current flowing in the storage element 3 is restricted to prevent the insulation destruction of the tunnel insulation layer. That is, a current necessary for the spin torque magnetization reversal should be suppressed to ensure the reliability of overwriting of the storage element 3 .
[0137] The current necessary for the spin torque magnetization reversal is also referred to as a reversal current or a recording current.
[0138] Since the storage device is a non-volatile memory, the storage device should stably store information written using a current. That is, it is necessary to ensure stability (thermal stability) against thermal fluctuation of the magnetization of the storage layer.
[0139] When the thermal stability of the storage layer is not ensured, the reversed direction of the magnetization may be reversed again due to heat (the temperature of an operation environment) in some cases, and therefore a writing error may be caused.
[0140] The storage element 3 of the storage device according to the embodiment of the present disclosure has the advantage of the scaling compared to an MRAM according to the related art, that is, the advantage of reducing the volume of the storage element. However, when the volume of the storage element is reduced, the thermal stability has a tendency to deteriorate under the same conditions of the other characteristics.
[0141] When the ST-MRAM has a large capacity, the volume of the storage element 3 is further reduced. Therefore, to ensure the thermal stability is an important task.
[0142] Accordingly, the thermal stability is a very important characteristic of the storage element 3 in the ST-MRAM. Even when the volume of the storage element is reduced, the storage element should be designed to ensure the thermal stability.
[0143] In the embodiment of the present disclosure, the size of the storage layer 17 of the storage element 3 is less than a size in which the direction of the magnetization is simultaneously changed. The specific size of the storage layer 17 of the storage element 3 is preferably equal to or less than a diameter of 45 nm. Thus, the power consumption is suppressed to be as small as possible. Thus, it is possible to realize the ST-MRAM using the thermal stability of the storage element 3 as much as possible.
[0144] The writing current for the storage element 3 is reduced. Since the power consumption is reduced, the entire power consumption of the storage device can be reduced.
[0145] The storage device shown in FIG. 1 and including the storage element 3 shown in FIG. 2 has the advantage of applying a general semiconductor MOS forming process when the storage device is manufactured.
[0146] Accordingly, the storage device according to this embodiment is applicable to a general-purpose memory.
3. Specific Configuration According to Embodiment
[0147] Next, a specific configuration of the embodiment of the present disclosure will be described.
[0148] In the configuration of the storage device, as described above with reference to FIG. 1 , the storage element 3 capable of holding information according to a magnetization state is disposed near an intersection of two kinds of address lines 1 and 6 (for example, a word line and a bit line) perpendicular to each other.
[0149] Further, when a current flows in the storage element 3 in the vertical direction via two kinds of address lines 1 and 6 , the direction of the magnetization of the storage layer 17 can be reversed through the spin torque magnetization reversal.
[0150] FIG. 3 shows a detailed configuration of the storage element 3 .
[0151] As shown in FIG. 3 , the storage element 3 includes the magnetization fixing layer 15 below the storage layer 17 in which the direction of the magnetization M17 is reversed through the spin torque magnetization reversal.
[0152] In the ST-MRAM, 0 and 1 of information are determined by relative angles of the magnetization M17 of the storage layer 17 and the magnetization M15 of the magnetization fixing layer 15 .
[0153] The insulation layer 16 configured as a tunnel barrier layer (tunnel insulation layer) is disposed between the storage layer 17 and the magnetization fixing layer 15 , so that the MTJ element is configured by the storage layer 17 and the magnetization fixing layer 15 .
[0154] The underlying layer 14 is formed below the magnetization fixing layer 15 .
[0155] The cap layer 18 is formed above the storage layer 17 (that is, the side adjacent to the storage layer 17 and opposite to the insulation layer 16 ).
[0156] In this embodiment, the storage layer 17 is a vertical magnetization layer formed of Co—Fe—B.
[0157] The cap layer 18 is formed of a conductive oxide.
[0158] The size of the storage layer 17 of the storage element 3 is less than a size in which the direction of the magnetization is simultaneously changed. The specific size of the storage layer 17 is preferably equal to or less than a diameter of 45 nm.
[0159] In this embodiment, when the insulation layer 16 is formed of a magnesium oxide layer, the magnetoresistance ratio (MR ratio) can be increased.
[0160] By increasing the MR ratio, it is possible to improve the spin injection effect and reduce the current density necessary to reverse the direction of the magnetization M17 of the storage layer 17 .
[0161] The storage element 3 according to this embodiment can be manufactured by continuously forming the underlying layer 14 to the cap layer 18 in a vacuum apparatus, and then forming the pattern of the storage element 3 by etching or the like.
[0162] According to the above-described embodiment, since the storage layer 17 of the storage element 3 is a vertical magnetization layer, it is possible to reduce the amount of writing current necessary to reverse the direction of the magnetization M17 of the storage layer 17 .
[0163] Thus, since the thermal stability can be sufficiently ensured as the information holding capability, the storage element 3 having the excellent characteristic balance can be configured.
[0164] Since an operation error can be presented and the operation margin of the storage element 3 can be sufficiently obtained, the storage element 3 can stably operate.
[0165] That is, the storage device operating stably and having high reliability can be realized.
[0166] Further, since the wiring current is reduced, it is possible to reduce the power consumption when information is written on the storage element 3 .
[0167] As a result, the storage device including the storage element 3 according to this embodiment can reduce the power consumption.
[0168] Thus, since a storage device having an excellent information holding characteristic and operating stably and reliably can be realized, the power consumption can be reduced in the storage device including the storage element 3 .
[0169] Further, the storage device shown in FIG. 1 and including the storage element 3 shown in FIG. 3 has the advantage of applying a general semiconductor MOS forming process when the storage element is manufactured.
[0170] Accordingly, the storage device according to this embodiment is applicable to a general-purpose memory.
4. Experiment According to Embodiment
[0171] Here, samples of the storage element 3 were manufactured while changing the size of the storage layer 17 in the configuration of the storage element 3 described above with reference to FIGS. 1 to 3 , and the characteristics of the storage element 3 were inspected.
[0172] In the actual storage device, as shown in FIG. 1 , not only the storage element 3 but also a switching semiconductor circuit and the like are present. However, an examination was made on a wafer on which only the storage element 3 was formed to examine the magnetization reversal characteristic of the storage layer 17 adjacent to the cap layer 18 .
[0173] A thermal oxide film with a thickness of 300 nm was formed on a silicon substrate with a thickness of 0.725 mm, and then the storage element 3 having the configuration shown in FIGS. 3 and 4 was formed on the thermal oxide film.
[0174] Specifically, the material and the thickness of each layer of the storage element 3 shown in FIG. 3 were as follows.
[0175] As shown in FIG. 4 , the underlying layer 14 was formed as a lamination layer of a Ta film with a thickness of 10 nm and a Ru film with a thickness of 25 nm, the magnetization fixing layer 15 was formed as a layer including a CoPt film with a thickness of 2.0 nm, a Ru film with a thickness of 0.8 nm, and a Co—Fe—B film with a thickness of 2.0 nm, the insulation layer 16 was formed as a magnesium oxide layer with a thickness of 0.9 nm, the storage layer 17 was formed as a CoFeB layer (A of FIG. 4 ) or a CoFeB/Ta/CoFeB layer (B of FIG. 4 ) with a thickness of 1.5 nm, and the cap layer 18 was formed as a layer including an oxide film with a thickness of 0.8 nm, a Ta film with a thickness of 3 nm, a Ru film with a thickness of 3 nm, and a Ta film with a thickness of 3 nm.
[0176] Here, the storage element 3 shown in A of FIG. 4 is indicated by Sample 1 and the storage element 3 shown in B of FIG. 4 is indicated by Sample 2.
[0177] In the film configuration, the composition of CoFeB of a ferromagnetic layer of the storage layer 17 was Co at 16%-Fe at 64%-B at 20%.
[0178] The insulation layer 16 configured by the magnesium oxide (MgO) film and the oxide film of the cap layer 18 were formed by an RF magnetron sputtering method and the other films were formed by a DC magnetron sputtering method.
[0179] Each sample was subjected to heat processing in a heat processing furnace in a magnetic field, after each layer was formed. Thereafter, the cylindrical storage layers 17 with diameters of 30 nm, 40 nm, 65 nm, 75 nm, 90 nm, and 120 nm were manufactured by general electron beam lithography and a general ion milling process.
[0180] The characteristics of each sample of the manufactured storage element 3 were evaluated as follows.
[0181] Before the measurement, a magnetic field was designed to be applied to the storage element 3 to control the values of the reversal current such that the values of the reversal current in positive and negative directions were symmetric.
[0182] The voltage to be applied to the storage element 3 was set up to 1 V within a range in which the insulation layer 16 was not destructed.
[0183] Measurement of Saturated Magnetization Amount and Magnetic Anisotropy
[0184] The saturated magnetization Ms was measured through VSM measurement using a vibrating sample magnetometer. Further, an anisotropy magnetic field Hk was measured by applying a magnetic field in a plane-vertical direction and an in-plane direction and sweeping the magnetic field (measurement of a reversal current value and thermal stability).
[0185] The reversal current value was measured to evaluate the writing characteristic of the storage element 3 according to this embodiment.
[0186] The resistive value of the storage element 3 was then measured by causing a current with a pulse width in the range of 10 μs to 100 ms to flow in the storage element 3 .
[0187] Further, the value of the current for which the direction of the magnetization M17 of the storage layer 17 of the storage element 3 was reversed was calculated by changing the amount of current flowing in the storage element 3 . A value obtained by extrapolating the pulse width dependency of the value of the current at a pulse width of 1 ns was set as the value of the reversal current.
[0188] The inclination of the pulse width dependency of the value of the reversal current corresponds to the index Δ of the above-described thermal stability of the storage element 3 . As the value of the reversal current is changed less by the pulse width (the inclination is small), the thermal stability means the strong degree against heat disturbance.
[0189] In consideration of a variation in the storage element 3 , twenty storage elements 3 with the same configuration were manufactured to carry out the above-described measurements, and the average values of the values of the reversal current and the indexes Δ of the thermal stability were calculated.
[0190] A reversal current density Jc0 was calculated from the average value of the values of the reversal current obtained through the measurement and the area of the plane pattern of the storage element 3 .
[0191] Here, FIGS. 5A and 5B show the size dependency of the storage layer 17 of the storage element 3 with respect to Ic ( FIG. 5A ) and Δ ( FIG. 5B ) obtained for Sample 1 from the experiment. In FIG. 5A , it can be confirmed that Ic increases as the size of the storage layer 17 increases, as anticipated from the equation of Ic_perp. Conversely, as shown in FIG. 5B , Δ does not coincide with the relation shown in Equation 3. Further, Δ does not monotonically increase, even when the size of the storage element increases.
[0192] To inspect the relation between Δ and the size of the storage layer 17 in more detail, the saturated magnetization Ms (=760 emu/cc) and the anisotropy magnetic field Hk (=2 kOe) were first inspected using VSM, and then Δ expected from the values of the matter properties was calculated using the saturated magnetization Ms, the anisotropy magnetic field Hk, and Equation 3. FIG. 6 shows a size dependency (indicated by ▴ in the drawing) of the storage layer 17 with respect to Δobtained from the experiment of Sample 1 and a size dependency (indicated by ▴ in the drawing) of the storage layer 17 with respect to Δ calculated based on the saturated magnetization Ms and the anisotropy magnetic field Hk obtained through the measurement of VSM. From FIG. 6 , it can be understood that the calculation result and the experiment result coincide with each other up to about 40 nm which is the diameter of the storage layer 17 , but the calculation result and the experiment result are increasingly different from each other in the element size equal to or greater than 40 nm. In general, when a magnetic body is small, uniform (simultaneous) magnetization rotation occurs. When a magnetic body is large, uneven magnetization rotation easily occurs.
[0193] The reason why the calculation result and the experiment result are different from one another is considered to be that the state of the matter property is changed when the magnetization of the storage layer 17 is reversed from the diameter of about 40 nm. That is, when the size of the storage layer is equal to or less than the diameter of about 40 nm, the magnetization of the storage layer 17 is considered to be simultaneously rotated.
[0194] When the size of the storage layer is greater than the diameter of about 40 nm, it is considered that the magnetization of partial portions in which rotation is easy in the storage layer 17 is initially reversed and the magnetization of the remaining portions is thus reversed due to the influence of the initial magnetization. In other words, the magnetization is considered to be unevenly rotated.
[0195] When Δ is regarded to be almost uniform in the storage layer 17 of which the size is equal to or greater than the diameter of 40 nm, the element size in which Δ obtained by the calculation coincides with Δ obtained by the experiment can be known to be 45 nm from the graph of an equation of “y=19697x+17.634.” This value can be considered as a value for making Ic as small as possible while Δ is ensured to be as large as possible. That is, the size of the storage layer 17 can be understood to be the diameter of 45 nm. The size of the storage layer can be converted to a volume of “1.5 nm×π×(45/2) 2 =2390 nm 3 .”
[0196] In the storage element 3 with a size equal to or less than the diameter of 45 nm, the good balance of Δ and Ic can be said to be maintained, as expected from the calculation result, since Δ and Ic are lessened.
[0197] Accordingly, when the storage element 3 indicated by Sample 1 is formed such that the size of the storage layer 17 is equal to or less than the critical size in which the direction of the magnetization is simultaneously changed, that is, the size of the storage layer 17 is equal to or less than the diameter of 45 nm, the power consumption can be suppressed to be as small as possible. Thus, it is possible to realize the ST-MRAM using the thermal stability of the storage element 3 as much as possible.
[0198] Likewise, FIGS. 7A and 7B show the size dependency of the storage layer 17 with respect to Ic ( FIG. 7A ) and Δ ( FIG. 7B ) obtained for Sample 2 from an experiment. FIG. 8 shows a size dependency (indicated by ▴ in the drawing) of the storage layer 17 with respect to Δ obtained from the experiment of Sample 2 and a size dependency (indicated by ♦ in the drawing) of the storage layer 17 with respect to Δ calculated based on the saturated magnetization Ms and the anisotropy magnetic field Hk obtained through the measurement of VSM. In Sample 2, the saturated magnetization Ms was 650 emu/cc and the anisotropy magnetic field Hk was 2.15 kOe. In Sample 2 shown in FIGS. 7A , 7 B, and 8 , when the size is equal to or less than the diameter of 45 nm as in Sample 1, the power consumption can be suppressed to be as small as possible. Thus, it is possible to realize the ST-MRAM using the thermal stability of the storage element 3 as much as possible.
[0199] When the storage layer 17 is formed of Co—Fe—B or a material in which a non-magnetic material is added to Co—Fe—B and the size of the storage layer 17 is equal to or less than the critical size in which the direction of the magnetization is simultaneously changed, that is, the diameter of 45 nm, as described above, the power consumption can be suppressed to be as small as possible. Thus, it is possible to realize the ST-MRAM using the thermal stability of the storage element 3 as much as possible.
[0200] The embodiment has been described, but the present disclosure is not limited to the layer configuration of the storage element 3 according to the above-described embodiment. Various layer configurations can be realized.
[0201] For example, in the above-described embodiment, the compositions of Co—Fe—B of the storage layer 17 and the magnetization fixing layer 15 are the same as each other. The present disclosure is not limited to the above-described embodiment, but may be modified in various ways within the scope not departing from the gist of the present disclosure.
[0202] The underlying layer 14 or the cap layer 18 may be formed of a single material or may have a lamination configuration of a plurality of materials.
[0203] The magnetization fixing layer 15 may be configured by a single layer or a lamination ferri-pin structure of two layers of a ferromagnetic layer and a non-magnetic layer. Further, an antiferromagnetic layer may be added to a layer with the lamination ferri-pin structure.
[0204] Additionally, the technology of the present disclosure may also adopt configurations as below.
[0000] (1) A storage element including:
[0205] a storage layer that holds information according to a magnetization state of a magnetic body;
[0206] a magnetization fixing layer that has magnetization serving as a reference of the information stored in the storage layer; and
[0207] an insulation layer that is formed of a non-magnetic body disposed between the storage layer and the magnetization fixing layer,
[0208] wherein the information is stored by reversing the magnetization of the storage layer using spin torque magnetization reversal occurring with a current flowing in a lamination direction of a layer configuration of the storage layer, the insulation layer, and the magnetization fixing layer, and
[0209] a size of the storage layer is less than a size in which a direction of the magnetization is simultaneously changed.
[0000] (2) The storage element according to (1), wherein a ferromagnetic material of the storage layer is Co—Fe—B.
(3) The storage element according to (1), wherein a non-magnetic material is added to Co—Fe—B of the ferromagnetic material of the storage layer.
(4) The storage element according to (1), (2), or (3), wherein the storage layer and the magnetization fixing layer have magnetization perpendicular to a film surface.
(5) The storage element according to (1), (2), or (3), wherein a diameter of the storage layer is less than 45 nm.
[0210] It should be understood that various changes and modifications to the presently preferred embodiments described herein will be apparent to those skilled in the art. Such changes and modifications can be made without departing from the spirit and scope of the present subject matter and without diminishing its intended advantages. It is therefore intended that such changes and modifications be covered by the appended claims.
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Provided is an information storage element comprising a first layer, an insulation layer coupled to the first layer, and a second layer coupled to the insulation layer opposite the first layer. The first layer has a transverse length that is approximately 45 nm or less, or an area that is approximately 1,600 nm 2 or less, so as to be capable of storing information according to a magnetization state of a magnetic material. The magnetization state is configured to be changed by a current. The insulation layer includes a non-magnetic material. The second layer includes a fixed magnetization so as to be capable of serving as a reference of the first layer.
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[0001] This application claims priority to our copending U.S. provisional patent applications with the Ser. Nos. 60/763,254 and 60/763,337, both filed Jan. 30, 2006, and which are incorporated by reference herein.
FIELD OF THE INVENTION
[0002] The field of the invention is peritoneal dialysis.
BACKGROUND
[0003] Patients with inadequate kidney function require either dialysis or kidney transplantation for survival. When successful, kidney transplantation is the most ideal form of treatment since it restores continuous kidney function and returns patients to normal or near-normal life. However, the major problems in transplantation are the increasing shortage of donor kidneys relative to the expanding number of patient's with end-stage kidney failure, and the deterioration of the function of the transplant from causes including rejection, chronic (transplant) allograft nephropathy and the recurrence of the original kidney disease. There is also the life-long requirement for multiple medications with toxic side effects.
[0004] Most patients are placed on dialysis, with about 90% being treated by hemodialysis (HD) in the United States. This requires the circulation of a large amount of blood outside the patient's body, through a sealed compartment constructed of artificial membranes (the dialyzer, also known as the artificial kidney) and back into the patient. Fresh dialysate generated by a machine is pumped through the other side of the compartment extracting water-soluble metabolic wastes and excess fluid from the blood across the artificial membrane. The used dialysate exiting the dialyzer is discarded as waste. Patients are treated for three to four hours, two or three times a week, mostly in special treatment centers, staffed with nurses and technicians supervised by physicians. The channeling of large amount of blood out of the body (extracorporeal circulation) requires rigorous anticoagulation and monitoring. (The production of dialysate for each treatment requires about 90 gallons (340 liters) of water to prepare 30 gallons (120 liters) of dialysate) and a machine with an average weight of about 200 lb. (91 kg.). Because metabolic wastes and water are accumulated for 2-3 days between dialysis and are then rapidly removed within 3-4 hours, most patients feel sick after each treatment and may require hours to days to recover. Unfortunately, by then the next treatment is due.
[0005] About 10% of dialysis patients are treated with peritoneal dialysis (PD). In PD, fresh dialysate (usually 2 liters) is introduced into the abdominal (peritoneal) cavity of the patient, which is lined by the patient's peritoneal membrane. Water-soluble metabolic wastes and excess water in the blood circulating on the other side of the peritoneal membrane move into the dialysate by diffusion and convection. After a period of time, the spent dialysate is drained and discarded. Fresh dialysate is delivered into the peritoneal cavity to begin a new treatment cycle. Patients on continuous ambulatory peritoneal dialysis (CAPD) make 3-4 such exchanges every day during waking hours, and one additional nightly treatment cycle, which lasts 8-12 hours while, asleep. An increasing number of patients now undergo nocturnal dialysis using an automatic peritoneal cycler to carry out dialysate exchanges. Typically, 10 to 20 liters of dialysate are used for 5-10 exchanges (2-liters per exchange) through hours of sleep at night. The high cost of the dialysate almost always results in suboptimal dialysis, especially in patients in whom the residual kidney function is completely lost. Another drawback of the current PD is that significant amount of blood proteins leak across the peritoneal membrane into the dialysate and are discarded with the spent peritoneal dialysate (SPD).
[0006] Indeed, many of the problems and limitations of the prior art of peritoneal dialysis systems stem from the fact that the ability to regenerate the SPD is either non-existent or, if present, are subject to limitations. Such problems and limitations include, for example:
1) The dialysate usage is limited to about 10 to 20 liters of fresh dialysate per day, primarily due to the high cost of fresh dialysate. This, in turn, limits the amount of toxins that can be removed from the patient; 2) The proteins in the SPD are discarded with the SPD, resulting in a state of continuous protein-loss in patients already protein-malnourished from end-stage kidney failure; 3) Two or more connections are made to the dialysis system, in addition to the catheter; 4) The sodium concentration is fixed by the sodium level in the fresh commercial dialysate, and cannot be easily adjusted once treatment is started; 5) Commercial peritoneal dialysate contains lactate and has a pH of about 5.5, both of which can cause irritation and possible damage to the peritoneal membrane; 6) Commercial peritoneal dialysate contains glucose degradation products formed during sterilization by autoclaving. Additional degradation products are formed during storage of the dialysate prior to its use. These degradation products can also cause damage to the peritoneal membrane. Further, there are only three different glucose concentrations in the currently available dialysates, and the need for a change in glucose concentration requires a change to a new batch of dialysate containing a glucose concentration approximating that needed; 7) With present peritoneal dialysis equipment, beneficial agents, such as nutrients, hormones, antibiotics, and other therapeutic and health-enhancing agents cannot be readily infused; 8) The prior art systems that employ sorbent SPD regeneration contain a urease layer in which the urease can be displaced by protein in the SPD; 9) The prior art systems do not regulate and maintain sodium concentrations and pH in the dialysate at steady levels prescribed by physicians in individual patients. 10) The prior art systems that employ sorbent SPD regeneration to remove urea by using urease and a cation exchanger (such as zirconium phosphate), generate considerable amounts of carbon dioxide, but provide no means to remove this gas or other gases in a fluid-leak proof manner, while at the same time maintaining sterility in systems designed to function under different conditions, e.g., in a wearable system; and 11) The prior art sorbent SPD regeneration systems generate ammonium ions, which appear in the effluent of the sorbent assembly when the zirconium layer is exhausted. Such systems typically have no provision for continuously monitoring the effluent for ammonium ions, and they therefore cannot set off an audible, visual, vibratory or other form of alarm and/or turn off the system in response to this condition.
[0018] Regeneration and re-use of dialysis fluids has been contemplated. For example, U.S. Pat. No. 4,338,190 to Kraus et al (July 1982) teaches a re-circulating peritoneal dialysis system, as does U.S. Pat. No. 5,944,684 to Roberts and Lee (June 1999), and a 1999 article, Roberts, M., A Proposed Peritoneal-Based Wearable Artificial Kidney, Home Hemodial Int , Vol. 3, 65-67, 1999. (WO 2005/123230 to Rosenbaum et al.) teaches a re-circulating hemodialysis system. These and all other referenced extrinsic materials are incorporated herein by reference in their entirety. Where a definition or use of a term in an incorporated reference is inconsistent or contrary to the definition of that term provided herein, the definition of that term provided herein applies and the definition of that term in the reference does not apply.
[0019] Despite contemplating regeneration, reconstitution and re-use of dialysis fluids, the prior art does not describe especially practical ways of accomplishing that goal. The '190 patent, for example, does not use a sorbent cartridge, and therefore is much less effective than modern, sorbent based systems. The Roberts article and patent do contemplate use of a sorbent, but contemplated overly complicated devices that required separate processing and then recombining of protein containing and protein free (ultrafiltrate) streams. In addition, none of the prior art teaches a unit that could practically be worn by a user, and that included the numerous improvements described herein. For example, in the '684 patent:
1) A single peritoneal catheter is used for infusing and removal of dialysate from the patient's peritoneal cavity. 2) The dialysate flow rate through the peritoneal cavity is limited to 2 to 3 liters per hour, and the dwell volume in the peritoneal cavity is limited to a volume of about 250 to 1,000 ml. 3) The regenerating system is housed in a single assembly having multiple contiguous compartments containing urease and sorbents, such as zirconium phosphate, zirconium oxide and activated carbon/charcoal. 4) The urease in the regenerating system is not immobilized and can be displaced by proteins in the spent peritoneal dialysate (SPD), thus requiring that the SPD be separated into an ultrafiltrate and a protein fraction for purposes of regeneration and to thereafter be re-united prior to their recycling back into the patient's peritoneal cavity. 5) In the urease/zirconium ion exchange sorbent regeneration system, the sodium concentration increases, and the hydrogen concentration decreases in the regenerated dialysate with time as regeneration progresses, thereby developing progressively higher sodium and pH. 6) No provision is made for the evacuation of carbon dioxide produced during the regeneration process, particularly as the goal of the wearable kidney is to allow the patient unrestricted activity that will call for different bodily positions. 7) No provision is made for the use of dry glucose and in situ sterilization of glucose for immediate use in the regulation of ultrafiltration. 8) No provision is made for in-line monitors with “feed-back loop” regulatory options of different components of the regenerated dialysate. 9) No provision is made for the regenerated peritoneal dialysate (RPD) to be enriched with nutrients, therapeutic agents, and other beneficial agents in dry or liquid form, sterilized in situ, and administered at programmed rates and timing patterns. 10) Removal of “noxious” or undesirable proteins, e.g., paraproteins, requires the separation of the protein fraction from the SPD. 11) No provision is made for removal of middle molecule uremic toxins.
[0031] Thus, there is still a need for improved systems that can function in multiple formats, including portable and wearable formats, in which peritoneal dialysate can be regenerated, reconstituted and re-used.
SUMMARY OF THE INVENTION
[0032] The present invention provides apparatus, systems and methods in which a peritoneal dialysate or other substantially non-blood containing fluid is withdrawn from the peritoneal cavity of a person or animal (generally referred to herein as a “person” or “patient” or “user”), the fluid is separated into a relatively protein-rich stream and a relatively protein-free stream. The relatively protein-rich stream is regenerated by processing to remove toxins, optionally reconstituted with additives, and then reintroduced into the peritoneal cavity. Use of a substantially immobilized urease allows a higher percentage of the fluid stream to be processed as the relatively protein-rich stream than in the prior art. For the first time it allows commercially practicable development of portable and even wearable dialysis units.
[0033] In one aspect of preferred embodiments the relatively protein-rich stream averages 95-98 vol % of the incoming stream from the peritoneal cavity of the user, which would mean that only about 2-5 vol % would comprise the relatively protein-free stream. In less preferred embodiments that percentage can be lower, preferably at least 90 vol %, at least 40 vol %, or even at least 15 vol %. All practical types of protein fluid separators are contemplated, including especially hollow fiber filters, but the type of separator need not dictate that percentage. For example, a pump can be used to alter or otherwise control the percentage of relatively protein-rich stream to the incoming stream.
[0034] A suitable sorbent system regenerates the protein-rich stream by removing at least one toxin. The sorbent system preferably includes a urease or other enzyme(s) that is/are immobilized on a substrate with greater than Van der Waals forces. This immobilization of the urease prevents its displacement by proteins in the incoming protein-rich fluid stream. Previous systems, including our own, utilized urease which was not adequately immobilized, which meant that only a very small fraction (e.g. 2-3%) of the fluid could be processed as protein-rich fluid, and that most of the fluid reintroduced into the user was derived from the protein free portion.
[0035] Sorbents are preferably included in user-replaceable assemblies consisting of at least 100 gm of sorbents (dry weight). It is contemplated that an assembly could include one or more of zirconium phosphate, hydrated zirconium oxide, and activated carbon/charcoal. A sorbent assembly could additionally or alternatively target removal of one or more specific proteins from at least a portion of the relatively protein-rich stream (dialysis phoresis) and one or more middle molecule uremic toxins using additional sorbents.
[0036] In preferred embodiments at least some other processing occurs to the protein-rich stream. For example, a processing line can include a cation and/or anion exchanger, which alters concentration in at least a portion of the relatively protein-free stream of at least one of H + , OH − , CO3 − and HCO3 − . Stabilization of the hydrogen ion concentration can also be enhanced by use of a zirconium phosphate layer as the final module in the sorbent cartridge.
[0037] The processing line can also advantageously include one or more of a sterilizer and a gas extractor. Gas extractors can be as simple as a vent (for portable systems), or more complicated, such as a hydrophilic/hydrophobic membrane filter (for wearable systems).
[0038] The relatively protein-free stream (ultrafiltrate) can be treated simply as waste, but in preferred embodiments has three other possible outcomes. Some of the protein-free stream can pass through an ion exchanger (anion, cation, or mixed bed), some of the stream can pass through an reverse osmosis filter, and/or some of the stream can be used to back flush the separator. In these latter three cases, the fluid is then added back to the relatively protein-rich stream.
[0039] Monitors and feedback loops are contemplated for maintaining a characteristic of the system, and for issuing a warning or shutting down the system when a measured characteristic falls outside of a desired range. Especially contemplated are monitoring and feedback for sodium concentration and pH. Monitoring and possible shutdown are especially contemplated for ammonia concentration.
[0040] Preferred embodiments also include at least one enrichment module that reconstitutes the protein-rich stream by adding at least one of glucose, potassium, calcium, and magnesium. In addition, it is contemplated that nutrients for long term alimentation and the administration of medications (e.g., antibiotics, chemotherapeutics), micronutrients, vitamins, hormones and any other therapeutic and health-maintaining and promoting agents and supplements could be added to the protein-rich stream as a way of introducing them into the patient (reverse dialysis). Delivery can be programmed on a continuous basis or on an on-demand basis, e.g., through a sensor-feedback-loop mechanism. An ultrasonic vibrator or other devices could be used to keep additives suspended, and/or facilitating their solvation. The fluid line that introduces the regenerated and reconstituted fluid back into the peritoneal cavity could use either the same or a different opening from that used to extract fluid, and could be operated concurrently or intermittently with the extraction fluid line.
[0041] For portable systems, the dry weight of the entire processing line (excluding a user-replaceable sorbent assembly) is preferably no more than 5 kg. The dry weight of user-replaceable sorbent assemblies is contemplated to be no more than 5 kg.
[0042] For wearable systems, the dry weight of the entire processing line (excluding a user-replaceable sorbent cartridge) is preferably no more than 1 kg. In such systems the dry weight of user-replaceable sorbent assemblies is contemplated to be no more than 1 kg. Wearable systems would generally also need a self-contained power supply. Such supplies should be sufficient to operate the processing line continuously for at least 8 hr, but could be designed for greater or lesser periods. To further enhance wearability, the internal and the external structure, functionality and material of the modules of the system can advantageously be designed to: 1) optimize aesthetic qualities and safety; 2) optimize dialysate regeneration and flow hydraulics; and 3) maximize the regenerative capacity and functional life of each module. To that end especially preferred modules are contemplated to be configured as non-rigid belts, packs or as apparel. The spent regenerative assembly or its individual components can be removed and replaced conveniently and safely (having in mind patients with impaired sensation and motor dexterity) using a sterility-maintaining undocking (“snap-out”) and docking (“snap-in”) mechanisms.
[0043] Preferred sorbent assemblies regenerate a relatively high percentage of fluid to the user over a relatively long period of time. Currently preferred embodiments, for example, will regenerate at least 80-90% of the substantially blood-free fluid as a protein-containing purified fluid over a period of 4 hours, and more preferably at least 80-90% over a period of 8 hours. Using another metric, currently preferred embodiments will re-circulate at least 20 liters of the substantially blood-free fluid as a purified fluid over a period of 10 hours, and more preferably at least 48 liters over a period of 24 hours. Using yet another metric, currently preferred embodiments will allow cumulative processing to occur at least 40 hours during a period of seven consecutive days, and more preferably 48, 56, 70, 126, or even almost 168 hours (full time except for replacement of power and chemical supplies).
[0044] In general, the inventive subject matter overcomes the various deficiencies in the prior art by providing a portable (and even wearable), automated peritoneal dialysis system based on the regeneration of a protein-containing dialysate. Because the system is peritoneal dialysis-based, it is “bloodless” and because the SPD is continuously regenerated, it is “waterless”. Furthermore, by utilizing sorbent regeneration in a portable artificial kidney, the peritoneal proteins in the SPD can be returned to the patient.
[0045] Various objects, features, aspects and advantages of the present invention will become more apparent from the following detailed description of preferred embodiments of the invention, along with the accompanying drawings in which like numerals represent like components.
BRIEF DESCRIPTION OF THE DRAWINGS
[0046] FIG. 1 is a schematic of a portable device coupled to a patient's peritoneal cavity, suitable for intermittent emptying and reintroduction of dialysate.
[0047] FIG. 2 is cross-sectional view showing the structure of the sorbent assembly of FIG. 1 ;
[0048] FIG. 3 is a schematic showing in-line monitoring and other controls for fluid flows within the device of FIG. 1 .
DETAILED DESCRIPTION
[0049] In FIG. 1 spent peritoneal fluid is withdrawn from a user/patient's peritoneal cavity 10 through catheter 110 A, and processed along a processing line that includes a separator 20 , an ultrafiltrate handling assembly 30 , a sorbent assembly 40 , and one or more ion exchangers 50 , optional storage module 60 , a specialty module 70 , a glucose module 80 , and an enrichment module 90 . The fluid is then pumped back into the peritoneal cavity through in-flowing catheter 110 B by pump 99 . All of the components of FIG. 1 , minus the catheters 110 A, 110 B and the peritoneal cavity 10 are sometimes referred to herein as artificial kidney 1 .
[0050] Catheters 110 A, 101 B should be interpreted interactively as either two physically separate catheters, or a single catheter with one or more lumens. All of the catheters, the various pumps 14 , 32 , 72 , 82 , 92 and 99 , and the various fluid conduits 112 , 114 , 116 A, 116 B, 116 C, 116 D, 118 , 120 , 122 , 124 A, 124 B, 126 A, 126 B, 126 C, 130 , 132 A, 132 B, 132 C, 132 D, 134 A, 134 B, 134 C, 136 A, 136 B, and 136 C can be entirely conventional. On the other hand, it is important that the components collectively support sufficient throughput of re-circulated fluid. For example, it is contemplated that the substantially blood-free fluid can be re-circulated as purified fluid at a rate sufficient to provide at least 18 liters of purified fluid over a 10 hour period, more preferably at least 20 liters, 30 liters, 40 liters and 48 liters over that same time period. In a 24 hour period it is contemplated that the substantially blood-free fluid can be re-circulated as purified fluid at a rate sufficient to provide at least 48 liters of purified fluid, more preferably at least 60 liters, still more preferably at least 72 liters, still more preferably at least 84 liters, and, still more preferably at least 96 liters.
[0051] To accomplish those ends it is contemplated that the various components will be sufficiently robust for processing to occur at least 40 hours during a period of seven consecutive days, which corresponds to 5 nights at 8 hours per night. More preferred embodiments provide for processing to occur at least 56 or 70 hours during a period of seven consecutive days. The 70-hour figure corresponding to 7 nights at 10 hours per night. Similarly, the various components of at least some embodiments should be sufficiently robust for processing to occur at least 126 hours during a period of seven consecutive days, which corresponds to 7 days at 22 hours per day.
[0052] Separator 20 comprises a hollow fiber or other material that can operate to split the incoming fluid into at least two streams, preferably a relatively protein-rich stream and a relatively protein-free stream. It is especially preferred that the relatively protein-rich stream (“protein-rich stream” for simplicity) has a significantly larger percentage of the fluid flow than was contemplated in the prior art. For example, instead of the protein-rich stream containing only 2-5 vol % of the input stream, and the protein-free stream (ultrafiltrate) containing 98-95 vol % (as in the prior art), separator 20 can advantageously maintain an average of at least 15 vol % of protein-rich stream relative to the input stream. In more preferred embodiments the filter 60 can maintain average protein-rich stream relative to input stream of at least 40 vol %, at least 60 vol %, at least 80 vol %, at least 90 vol %, at least 95 vol % and even at least 98 vol %, where the averages are taken over a meaningful processing period of an hour or more.
[0053] Over several hours, the split between the relatively protein-rich and relatively protein-free streams mentioned is a significant factor in determining how much of the substantially blood-free fluid is re-circulated as the purified fluid. Currently preferred embodiments re-circulate at least 80% over a period of 4 hours, more preferably at least 80% over a period of 4 hours, and still more preferably at least 80% over a period of 8 hours.
[0054] In contrast to the previous art, preferred embodiments can retain almost all of the autologous proteins in the protein-rich stream, thereby minimizing or eliminating protein-loss. Such proteins are, of course, non-sensitizing, and also have the benefit of providing oncotic pressure to retard trans-peritoneal (fluid) re-absorption, reducing or eliminating the need for the addition of glucose to the fluid being reintroduced into the peritoneal cavity 10 .
[0055] The distribution of fluid between the relatively protein-rich and relatively protein-free streams can be controlled in various manners, including pumps and valves. In the embodiment of FIG. 1 , pump 32 can be used to alter that distribution, at least to some extent. Valve 21 can also be used to that end.
[0056] The ultrafiltrate handling assembly 30 is contemplated to always include a provision for eliminating waste fluid from the system, but can additionally include apparatus for optional handling of the relatively protein-free fluid stream. FIG. 1 depicts an ultrafiltrate pump 32 that pumps fluid to valve 33 , providing four outcomes.
1) Some and most likely most of the protein-free stream, will be pumped to the waste container 34 . Most or all of the fluid in the waste container 34 will be disposed of, perhaps in a urinal or toilet; 2) Some of the protein-free stream can be pumped through a reverse osmosis unit 35 , to provide a diluent that can be added back into the protein-rich stream; 3) Some of the protein-free stream can be pumped through a user-replaceable ion exchanger module 36 (anion, cation, or mixed bed) to alter pH and perhaps other factors. Output of the ion exchanger module 36 can also be added back into the protein-rich stream; and/or 4) Some of the stream can be used to back flush the separator, by using pump 32 to pump the fluid in waste container 34 back through the separator 20 .
[0061] The sorbent assembly 40 is described in detail below with respect to FIG. 2 .
[0062] Downstream of sorbent assembly 40 are one or more monitors (sensors) 202 , 212 , 222 , 232 , 242 , and 252 , all of which are more fully described with respect to FIG. 3 .
[0063] Ion exchanger 50 is connected in parallel to fluid line 122 using shunt fluid lines 124 A and 124 B. Ion exchanger 50 can comprise an anion exchanger, a cation exchanger, or a mixed bed exchanger, and can advantageously alter a concentration of one, two, three or all four of H + , OH − , CO 3 − and HCO 3 − in the fluid passing through the exchanger, as well as other desired ions. One important use of ion exchanger 50 is to reduce sodium produced by conversion of urea within the sorbent assembly 40 . Since the production of sodium will change over time, a control valve 52 controls how much of the flow from the sorbent assembly 40 enters the exchanger 50 .
[0064] Storage module 60 is entirely optional. In either wearable or portable units, for example, fluid can be continuously withdrawn from the peritoneal cavity 10 , processed, and then re-introduced into the cavity 10 , all without any need for storage of the fluid being reintroduced. But where intermittent processing is desired, the storage module 60 advantageously retains the processed (or semi-processed) fluid until it is reintroduced. Contemplated storage capacities range from about 500 ml to about 3 liters. Unless the language context dictates otherwise, all ranges herein are to be interpreted as being inclusive of their endpoints.
[0065] Gas removal unit 65 is needed because the conversion of urea to ammonium carbonate the exchange of ammonium ions for hydrogen ions, and the reaction of the hydrogen ions with carbonate in the sorbent assembly 40 , produce substantial amounts of carbon dioxide. Since CO 2 (and any other gases within the processing line) can be problematic, they should be removed from the system. In portable systems removal can be accomplished merely by venting, and the gas removal unit 65 should be interpreted as merely a vent. In wearable systems, however, venting is not practical because the user/patient might well be positioned from time to time that a vent would be upside down. In such cases gas removal can be accomplished using a hydrophobic or combination hydrophobic/hydrophilic filter, and the gas removal unit 65 should be interpreted as comprising such filter(s). Valves 62 , 64 controls flow of fluid into and out of the storage module, respectively. An additional pump (not shown) can also be used.
[0066] Specialty module 70 is intended herein to provide additional processing not satisfied by the other modules. For example, specialty module 70 could provide the functionality of dialysis phoresis, removing one or more specific proteins from the fluid. Pump 72 can be used to control the amount of fluid passed through to specialty module 70 , and filter 74 filters the fluid returning to the main processing flow.
[0067] Glucose module 80 adds glucose to the fluid being processed by means of a glucose supply conduit 134 . Two-way pump 82 facilitates this process, and indeed allows for variable control of glucose concentration in contrast to the current art, in which only three concentrations of glucose are available. Filter 84 eliminates unwanted particles and provides sterilization.
[0068] Enrichment module 90 can add substantially any desired enriching material, including for example one or more of glucose, potassium, calcium, and magnesium. Such materials can be added to the fluid being processed by means of an enrichment material supply conduit 136 A using a two-way pump 92 . It is contemplated that medications (e.g., antibiotics, chemotherapeutics), micronutrients, vitamins, hormones, and any other therapeutic and health maintaining and promoting agents and supplements, can also be introduced into the user/patient through the returning fluid. Introduction of such additional substances is known as reverse dialysis.
[0069] One or more of the glucose and enrichment materials can be supplied as a dry powder, and then dissolved in the fluid being processed. This is considered advantageous because dry glucose and other materials would tend to avoid degradation products that tend to be present in heat-sterilized fluids. In the embodiment of FIG. 1 , dry glucose can be dissolved in the process fluid, and then filtered through a sterilizing filter 84 . Similarly, dry enrichment chemicals can be dissolved in the process fluid, and then filtered through a sterilizing filter 94 . Each of elements 70 , 80 and 90 can optionally include a device, such as an ultrasonic vibrator ( 75 , 85 , and 95 , respectively), that assists in dissolving and/or suspending the material being added.
[0070] In a typical example of intermittent processing, about two liters of suitable electrolyte solution would be introduced into a patient for a first treatment. After a set waiting period (e.g., 0-1 hour), the peritoneal outflow pump 14 is started to pump what is now the SPD along the first part of the processing line, and into the storage module 60 with a small fraction going into module 30 . When the storage module 60 fills to approximately two liters, the storage module 60 is closed at valve 62 . The storage module outflow valve is opened, the specialty module pump 72 , the glucose pump 82 , the enrichment pump 92 , and the peritoneal inflow pump 99 are all started, and the now-processed fluid flows back into the user/patient until the storage module is empty. The process is then repeated. When convenient, the waste fluid in waste container 34 is emptied.
[0071] In a typical example of continuous processing, a system containing about 2 liters of a suitable electrolyte solution would be introduced into a patient for a first treatment. Instead of introducing that entire amount in to the patient all at once, a smaller bolus of fluid is optionally introduced to get the process started, (e.g. 500-1500 ml), and subsequently the fluid is slowly pumped into the patient, preferably at a rate of 34-67 ml/min. At the same time fluid is slowly withdrawn from the peritoneal cavity at approximately the same rate for processing as described herein.
[0072] Compared to current technology of using 10-20 liters of fresh dialysate for an 8-10 hour treatment, treatment using the device of FIG. 1 can provide 20-40 (or more) liters of regenerated dialysate over the same time period. This will bring about a two-fold or more increase in dialytic efficiency. Further, regeneration of the peritoneal proteins in the SPD would virtually eliminate protein-loss and, for the first time, remove protein-bound toxins without protein-loss. The recycling of the regenerated proteins also provides oncotic pressure and reduces or eliminates the amount of glucose required for fluid removal. Once initiated, the present invention requires no additional fresh dialysate, since dialysate would be regenerated from SPD as long as needed (theoretically, in perpetuity). In addition, the regenerated dialysate would have a physiological pH (7.4) and would contain the normal body base (bicarbonate). Both are considered advantages in maintaining normal body physiology and in preserving the peritoneal membrane. The currently available dialysate is acidic and contains lactate, both of which have been shown to be detrimental to the peritoneal membrane.
[0073] It is especially contemplated that the entire processing line, which comprises all of the components between catheters 110 A and 110 B, would advantageously be engineered for compactness and even wearability. Thus, for example, the entire processing line, excluding a user-replaceable sorbent cartridge, could be made to weigh no more than 8 kg, more preferably no more than 4 kg, and most preferably no more than 2 kg.
[0074] In FIG. 2 the sorbent assembly 40 includes in sequential flow order: a fibrin filter 41 ; a purification layer 42 ; a bound urease layer 43 ; a zirconium phosphate layer 44 a hydrated zirconium oxide layer 45 ; an activated carbon layer 46 ; a buffer layer 47 to stabilize pH; a middle molecule sorbent layer 48 , and finally a particulate filter 49 . Those skilled in the art will appreciate that one or more of the layers can optionally be eliminated, and indeed the various materials shown as residing in layers of a single assembly could be housed in separate modules or cartridges, and/or included in different sequences from that expressly shown herein.
[0075] Preferred fibrin filters will be capable of filtering out other particulates (e.g. mucus, semisolids and solids)
[0076] Of particular interest is that the urease in the sorbent assembly is immobilized onto a matrix in a fashion that allows easy sterilization without significant loss of its activity and renders the enzyme resistant to displacement by proteins in the fluid being processed. Immobilization is defined here to mean that the urease is attached to a substrate with a force greater than Van der Waals forces, and can occur in any number of ways, including possibly covalent and/or ionic bonding of the urease to a substrate.
[0077] The middle molecule sorbent layer 48 can comprise any suitable material or combination of materials. The concept of middle molecules uremic toxins and materials for removing middle molecules are discussed in: Winchester, James F., et al., The Potential Application of Sorbents in Peritoneal Dialysis, Contributions to Nephrology , Vol. 150, 336-43, 2006; Vanholder, R., et al., Review On Uremic Toxins, Classification, Concentration, And Interindividual Variability, Kidney International , Vol. 63, 1934-1943, 2003; and Chiu A, et al., Molecular adsorbent recirculating system treatment for patients with liver failure: the Hong Kong experience, Liver International , Vol. 26, 695-702, 2006.
[0078] Sorbent assemblies 40 can be provided in many different sizes. In most instances it is contemplated that individual assemblies will contain at least 100 gm of sorbent, with larger sizes depending upon intended use, all weights herein being given in dry weight. For example, sorbent assemblies for portable units might weigh no more than 2.0 kg, and more preferably no more than 1.5 kg. This compares favorably with typical hemodialysis sorbent assemblies that weigh about 2.5 kg. For wearable units, the sorbent assemblies would likely weigh no more than 2 kg, more preferably no more than 1 kg, and most preferably no more than 0.5 kg.
[0079] Sorbent assemblies 40 can also be provided in many different shapes. For portable units the shape is not particularly important, but for wearable units it is contemplated that the assemblies would be relatively flat, and possibly even slightly concave on one side, to facilitate carrying of the assemblies in a belt.
[0080] In FIG. 3 , the artificial kidney 1 operation of the valves and the activation/deactivation of pumps, as well as the overall control of the system and methods of the present invention, are advantageously controlled by a microcomputer 200 , so that the various operations/treatments occur automatically. Among other things such control involves monitors and feedback loops that maintain concentrations of select components within desired ranges, and possibly shut down the unit when certain specific conditions are detected.
[0081] To that end microprocessor 200 can receive signals from a sodium monitors 202 and 212 , and through a feedback loops 204 and 214 , control ion exchanger valves 33 and 52 , respectively to maintain an average sodium concentration of at least a portion of the relatively protein-rich stream within a desired range over a period of at least 1 hour. Preferred concentrations of sodium in any fluid re-introduced into the user/patient is 135-145 meq/l, and most preferably 140 meq/l.
[0082] Similarly, microprocessor 200 can receive signals from a pH monitor 222 , and through a feedback loop 224 control pump 32 to maintain a pH within a desired range over a period of at least 1 hour. Currently preferred pH is between 6.5 and 8, and most preferably about 7.4.
[0083] Microprocessor 200 also preferably receives signals from ammonia detector 232 and feedback loop 234 that triggers an action when an ammonia concentration in at least a portion of the relatively protein-rich stream is greater than a desired upper limit, such as 2 mg %. The most likely action is shutting down of the system by directing pump 14 and 99 to stop operating, and/or sounding an alarm 300 because presence of ammonia means that the sorbent assembly is spent and must be replaced. Shutting down of the system could be accomplished in any suitable way.
[0084] Microprocessor 200 can also receive signals from a glucose detector 242 , and through a feedback loop 244 control pump 82 to maintain average glucose concentration within a desired range over a period of at least 1 hour. Currently preferred glucose concentrations are between 1.5 and 4.25 g/dl, and most preferably about 2 g/dl. It is also contemplated that the user/patient could control glucose concentrations manually to at least some extent.
[0085] Still further, microprocessor 200 can receive signals from potassium, calcium, or magnesium detectors, collectively 252 , and through a feedback loop 254 control pump 92 to maintain average concentrations of one or more of these elements within a desired range over a period of at least 1 hour. Currently preferred potassium concentrations are between 0 and 4 meq/L, and most preferably about 1 meq/L. Currently preferred calcium concentrations are between 2.5 and 4 meq/L, and most preferably about 3.5 meq/L. Currently preferred magnesium concentrations are between 1 and 3 meq/L, and most preferably about 2.5 meq/L.
[0086] Power source 400 is the power source that powers artificial kidney and related electronics. This is mostly likely line current for a portable unit, and a user replaceable rechargeable battery pack for a wearable unit. In any event, FIG. 3 the power source is shown as a battery because even portable units can advantageously include a battery pack that acts as an uninterruptible power supply. Power source 400 should preferably have sufficient power to operate the processing line continuously for at least 5 hours, more preferably at least 8 hours, and still more preferably at least 12 hours. In some cases it may be desirable to have battery life of at least 15, and in other cases at least 24 hours. The rationale for those time periods is that user/patients with wearable units will likely change their sorbent assemblies about ever four hours during the day, and up to 10 hours when they are sleeping at night. In other cases user/patients may be on a trip or have some other circumstance where longer battery life may be desirable.
[0087] Embodiments of the inventive subject matter have numerous benefits over the prior art, including for example:
1) Manufacture of the regenerative assembly from interconnected modules (whether housed in one single unit or several different units) allows designers to: (a) optimize portability, aesthetic qualities and safety; (b) optimize dialysate regeneration and flow hydraulics; and (c) maximize the regenerative capacity and functional life of each module. 2) Recycling of 2-4 liters of fluid per hour can provide much better removal of toxins than the 10-20 liters now used for each treatment in the current intermittent methods; 3) Recycling of dialysate is much less expensive than purchasing and consuming an equal volume of fresh dialysate; 4) Once treatment is initiated, there is no requirement for additional dialysate supply; it is therefore “waterless” as that term is used in some of the literature; 5) Proteins in the SPD are conserved instead of being discarded, thereby enhancing the removal of protein-bound toxins and providing oncotic pressure, all without triggering immune events; 6) The number of connections can be greatly reduced, such as by eliminating connections to a fresh dialysate supply source as required with currently available peritoneal dialysate cyclers; 7) Through incorporation of modules customized for specific protein removal, contemplated embodiments can provide plasmaphoresis of noxious and undesirable proteins; 8) Concentrations of sodium, glucose, nutrients, hormones, antibiotics, and other substances can all be controlled during treatment, using in-line monitors, all without degradation byproducts; 9) The regenerated peritoneal dialysate, in addition to its protein content, has the unique features of exhibiting a normal pH and contains bicarbonate rather than lactate or other metabolizable anions. The composition of bicarbonate, sodium, pH and other cations and anions can be altered, singly or in combination, according to specific prescriptions for the management of disorders including electrolytes, minerals and acid-base abnormalities. 10) The automated portable artificial kidney of the present invention makes possible a reduction in demand for specialized physical facilities, for medical personnel and for obligatory patient labor (thereby, avoiding patient treatment fatigue). No permanent treatment space is required, and medical and technical consultation can be scheduled on a regular basis, e.g., monthly. 11) Patient involvement consists mainly to setting up the portable artificial kidney nightly or with the wearable changing cartridges and the glucose and enrichment modules every 4 hours.
[0099] Thus, specific embodiments and applications of peritoneal dialysis apparatus, systems and methods have been disclosed. It should be apparent, however, to those skilled in the art that many more modifications besides those already described are possible without departing from the inventive concepts herein. The inventive subject matter, therefore, is not to be restricted except in the spirit of the appended claims. Moreover, in interpreting both the specification and the claims, all terms should be interpreted in the broadest possible manner consistent with the context. In particular, the terms “comprises” and “comprising” should be interpreted as referring to elements, components, or steps in a non-exclusive manner, indicating that the referenced elements, components, or steps may be present, or utilized, or combined with other elements, components, or steps that are not expressly referenced. Where the specification claims refers to at least one of something selected from the group consisting of A, B, C . . . and N, the text should be interpreted as requiring only one element from the group, not A plus N, or B plus N, etc.
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A peritoneal-based (“bloodless”) artificial kidney processes peritoneal fluid without need for additional fluids (“waterless”). Fluid is separated into a protein-rich stream and a protein-free stream. The protein-rich stream is regenerated using a sorbent assembly, and its protein composition can be modified by removal of selected protein(s) (“dialysate-pheresis”). It is then reconstituted with additives and returned into the peritoneal cavity, thereby reducing protein-loss and providing oncotic-pressure for ultrafiltration. The protein-free stream is used to produce free water, and an alkaline or acid fluid for optimization of the composition of the regenerated stream. The unused protein-free stream can be used to “reverse flush” the separator to maintain its patency and the excess discarded for fluid-balance regulation. Compared to prior art, immobilization of urease allows more protein rich fluid to be regenerated and re-circulated into the peritoneal cavity for toxin removal and allows practicable development of portable and wearable artificial kidneys.
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CROSS-REFERENCES TO RELATED APPLICATIONS
None.
FIELD OF THE INVENTION
The invention is in the field of radio frequency (RF) communication devices. More particularly, the present invention relates generally to radio frequency identification (RFID) devices and for creating RFID devices having a protective cap element that are suitable for use in non-planar environments in which RFID devices may be subjected to structural stress.
BACKGROUND OF THE INVENTION
Radio frequency identification (RFID) tags and labels (collectively referred to herein as “devices”) are widely used to associate an object with an identification code or other information. RFID devices generally have a combination of antennas and analog and/or digital electronics, which may include for example communications electronics, data memory, and control logic. For example, RFID tags are used in conjunction with security locks in cars, for access control to buildings, and for tracking inventory and parcels.
As noted above, RFID devices are generally categorized as labels or tags. RFID labels are RFID devices that are adhesively or otherwise have a surface attached directly to objects. RFID tags, in contrast, are secured to objects by other means, for example by use of a plastic fastener, string or other fastening means.
RFID devices include active tags and labels, which include a power source for broadcasting signals, and passive tags and labels, which do not. In the case of passive devices, in order to retrieve the information from the chip, a “base station” or “reader” sends an excitation signal to the RFID tag or label. The excitation signal energizes the tag or label, and the RFID circuitry transmits the stored information back to the reader. The RFID reader receives and decodes the information from the RFID tag. In general, RFID tags can retain and communicate enough information to uniquely identify individuals, packages, inventory and the like. RFID tags and labels also can be characterized as to those to which information is written only once (although the information may be read repeatedly), and those to which information may be written to repeatedly during use. For example, RFID tags may store environmental data (that may be detected by an associated sensor), logistical histories, state data, etc.
RFID devices further can be characterized as passive, semi-passive, and active RFID devices. Passive RFID devices have no internal power supply. Power for operation of passive RFID devices is provided by the energy in an incoming radio frequency signal received by the device. Most passive RFID devices signal by backscattering the carrier wave from an RF reader. Passive RFID devices have the advantage of simplicity and long life, although performance of them may be limited.
There are at least two approaches to assembling RFID devices having IC chips with antennas and/or other electronic components. The IC chips are manufactured on a wafer and are typically delivered as a sawn wafer. The antennas which may be printed, etched or die cut are provided on a flexible web. In the first approach, manufacturers use precision pick-and-place machines to bond and electrically connect the bare IC chips directly to the other device components (e.g., antenna) without any intermediate connecting leads. These electronic components are placed into the substrate circuitry in a single process.
The second route of RFID assembly uses an intermediate connection lead instead of bonding bare dies directly onto the substrates. This is because as the chips become smaller, the process of interconnecting IC chips with antennas becomes more difficult. Thus, to interconnect the relatively small IC chips to the antennas in RFID inlays, intermediate structures variously referred to as “strap leads,” “interposers,” and “carriers” are sometimes used to facilitate inlay manufacture. The intermediate structures include conductive leads or pads that are electrically coupled to the contact pads of the chips for coupling the chips to the antennas. These leads provide a larger effective electrical contact area between the chips and the antenna than do the contact pads of the chip alone. With the use of the intermediate structures, the alignment between an antenna and a chip does not have to be as precise during the direct placement of the chip on the antenna as without the use of such strap leads.
Regardless of how the chip is attached to the antenna, either directly or through a strap, one issue that is encountered during the use of the RFID tag is when the label (i.e., substrate) is attached to a package and the label does not lie or remain on a completely flat surface. As the labels are bent, the die/antenna juncture is subject to stress and is prone to fracturing and breaking. In addition, the antenna may also be subject to bending and having its functionality compromised thereby. For example, the antenna may become detached from the substrate as the label bends. The same issues occur when the RFID tag is attached to an article that is subject to bending, such as an article of clothing or fabric material. Other bendable materials include sheets of plastic or metal. Moreover, the IC can be simply knocked off during the application of the RFID tag to the article or during subsequent processing such as during the step of printing the label.
Accordingly, there is a long-felt, but as yet unsatisfied need in the RFID device manufacturing field to be able to produce RFID devices that address the deficiencies noted above.
BRIEF SUMMARY OF THE INVENTION
The embodiments of the present invention described below are not intended to be exhaustive or to limit the invention to the precise forms disclosed in the following detailed description. Rather, the embodiments are chosen and described so that others skilled in the art may appreciate and understand the principles and practices of the present invention.
The RFID device of the present invention overcomes potential drawbacks of existing RFID devices in that a more dynamic structure is used to enable use of RFID devices in non-planar applications where structural stresses may be applied to the RFID device as opposed to those situations where the RFID device is simply provided on a flat surface.
In one exemplary embodiment of the presently described invention, an RFID device is provided and includes a substrate that has first and second surfaces. An antenna is applied to the first surface of the substrate and a chip is connected to the antenna on the first substrate. A protective cap is applied substantially over the chip and at least a portion of the antenna with the protective cap extending generally upwardly from the first surface of the substrate.
In another exemplary embodiment of the presently described invention an RFID device is described and includes a housing which has an exterior portion and an interior portion, with the interior portion having a cavity that has a first dimension. An RFID inlay is disposed within the cavity and the inlay has a second dimension that is less than the first dimension. The RFID inlay includes a substrate that has first and second surfaces. An antenna is provided on the first surface and a chip is connected to the antenna on the first surface. A protective covering is provided substantially over the chip and at least a portion of the antenna.
In a still further exemplary embodiment of the presently described invention a method of making an RFID device is described and includes the steps of initially providing an RFID inlay with the RFID inlay including a substrate that has first and second surfaces with an antenna applied to the first surface and a chip connected to the antenna. Next, the chip and a portion of the antenna is covered with a protective cover. Then, a housing is prepared that has an exterior portion and an interior with the interior portion defining a cavity prior to the step of providing an RFID inlay. The RFID inlay is positioned within the cavity of the housing and the housing is sealed around the inlay.
These and other objects of the invention will become clear from an inspection of the detailed description of the invention and from the appended claims.
BRIEF DESCRIPTION OF THE DRAWINGS
These, as well as other objects and advantages of this invention, will be more completely understood and appreciated by referring to the following more detailed description of the presently preferred exemplary embodiments of the invention in conjunction with the accompanying drawings, of which:
FIG. 1 is a perspective view of an RFID inlay showing a protective covering over the chip.
FIG. 2 is a side elevation of an RFID inlay showing the protective cap extending generally upwardly.
FIG. 3 is a prospective view of a housing containing a cavity in which an RFID inlay has been positioned.
FIG. 4 shows a side elevation of a sealed housing with an RFID inlay provided therein.
FIG. 5 provides a block diagram setting forth an exemplary method for practicing the presently described invention.
DETAILED DESCRIPTION OF THE INVENTION
The present invention is now illustrated in greater detail by way of the following detailed description which represents the best presently known mode of carrying out the invention. However, it should be understood that this description is not to be used to limit the present invention, but rather, is provided for the purpose of illustrating the general features of the invention.
Reference is now directed to FIG. 1 which shows an RFID inlay, generally designated by reference numeral 10 . The inlay 10 is provided on a substrate 12 that has a first surface 14 and a second surface (not shown). On the first surface 14 is an antenna 16 . The antenna may be prepared by printing conductive ink, etching metal or die cutting a conductive material, such as foil, in the desired pattern for the antenna. A chip or an integrated circuit 18 is attached to the antenna 16 typically through the use of adhesive. Alternatively, conductive leads 20 and 22 can be provided to facilitate the placement of the chip 18 on the antenna 16 . A protective cap or covering 24 is provided over the chip and at least a portion of the antenna 16 .
The protective covering 24 may also cover a portion of the antenna 16 and conductive leads 20 and 22 if provided. The conductive leads along with the chip are also known as a strap assembly. The protective covering or cap 18 shown in FIG. 1 is illustrated as a relatively quadrate structure, but may take any other regular geometric shape such as a circle, oval, square, rectangle, etc. or any other irregular shape that may be created. The material suitable for use in the protective cap may be selected from suitably flexible materials such as polyethylene, polyurethane and other plastic and rubber like materials.
Turning now to FIG. 2 , a side elevation of an RFID inlay 10 is provided having a substrate 30 with first and second surfaces 32 and 34 , respectively. The substrate is preferably a polymeric material such as a polyethylene based film, but other materials may be suitable including paper. Disposed on the first surface 32 of the substrate 30 is the chip 36 which is covered by a protective cap or covering 38 . As can be seen from FIG. 2 , the protective cap extends generally upwardly from the first surface of the substrate.
FIG. 3 presents a housing generally depicted by reference to numeral 40 having an exterior portion 42 and an interior portion 44 that defines a cavity 46 . The cavity 46 has a first dimension and an inlay 48 has a second dimension that is preferably less than the first dimension. As shown in FIG. 3 , the inlay 48 is attached along an end edge 50 to the interior portion 44 of the housing 40 . The inlay 48 can be attached at any portion of the interior portion 44 of the housing 40 or may simply be free floating within the cavity 46 . In addition, the cavity 46 can be filled with an inert gas, such as neon or helium, gel or liquid or alternatively, the air space created in the cavity may not have any components or elements added.
FIG. 4 provides a cross section or cut away side view of the housing 40 with the inlay 48 shown floating in the cavity 46 . The inlay 48 is also shown with the protective cap 49 . In addition, in FIG. 4 , the housing 40 is sealed through use of a cover 52 to prevent damage occurring to the inlay.
The housing 40 depicted in FIGS. 3 and 4 may be made of any suitable material and may be rigid or flexible depending on the application that will use the housing.
Reference is now directed to FIG. 5 in which a block diagram showing an exemplary method for practicing the present invention is illustrated. The process is started such as by providing a housing with a cavity at step 100 . The housing itself will have an external portion making up the exterior of the housing and an interior portion that defines a cavity. The cavity will have a first dimension.
Next, at step 110 an RFID inlay is provided. RFID inlays are available under the trade names AD-222, AD-224 and Flexwing all available from Avery Dennison Corporation, Pasadena, Calif.
At step 120 the connective portions of the inlay assembly, the chip and that portion of the antenna, as well as any conductive leads used to connect the chip to the antenna are covered with a protective cap or material. The material used for the covering ideally should be flexible, so that as the inlay is flexed or bent, the material will not crack and will bend with and protect the connective elements. Suitable materials include rubber, plastics, foams and the like.
The RFID inlay is then positioned within the cavity at step 130 . The step of positioning does not require the inlay to be physically attached to the housing, but rather the inlay can be freely floating within the housing or air space to allow fewer stresses to be impacted upon the inlay. In an alternative step 135 , the inlay can be attached to the cavity wall such as through the use of adhesive. In addition the attachment can occur during the molding of the housing if the inlay is presented during the manufacture of the housing.
Finally, the housing can be sealed at step 140 to further protect the inlay and to mitigate the amount of stress that is imparted to the inlay during the use of the housing in a particular application.
It will thus be seen according to the present invention a highly advantageous RFID device and method of manufacturing has been provided. While the invention has been described in connection with what is presently considered to be the most practical and preferred embodiment, it will be apparent to those of ordinary skill in the art that the invention is not to be limited to the disclosed embodiment, and that many modifications and equivalent arrangements may be made thereof within the scope of the invention, which scope is to be accorded the broadest interpretation of the appended claims so as to encompass all equivalent structures and products.
The inventors hereby state their intent to rely on the Doctrine of Equivalents to determine and assess the reasonably fair scope of their invention as it pertains to any apparatus, system, method or article not materially departing from but outside the literal scope of the invention as set out in the following claims.
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The present invention relates to a dynamic RFID device assembly which is able to withstand the additional stresses of using RFID devices in a non-planar arrangement. The invention includes the provision of a protective cap to prevent the fracturing or breakage of chip and antenna connection. The RFID device of the present invention can be included in a housing which may also be flexible thereby adding additional stability to the device.
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FIELD OF INVENTION
[0001] The invention relates to a vessel for use in the offshore industry on which a multipurpose tower and a module handling system are mounted.
[0002] The module handling system includes a module moving system that can move heavy equipment and sub sea modules over the deck of the vessel. The system also has a moonpool hatch that can stabilize modules when those are lowered or hoisted through the moonpool. The moonpool hatch can serve as a working platform and as a support for the module moving system.
[0003] The multipurpose tower is fitted with a main and auxiliary trolley, hoists, and cable, as well as accommodations for an elevating working platform.
BACKGROUND OF THE INVENTION
[0004] The present invention is a conversion of and claims priority from co-pending provisional patent application 60/407,424, filed on Aug. 30, 2003.
[0005] Today a significant percentage of the production equipment is not installed on the surface of the sea, but on the sea bottom. As with all equipment, the equipment on the sea bottom needs regular maintenance. Specifically, during the lifetime of an oilfield, the bore holes and the oilfield itself need maintenance to keep the production as high as possible.
[0006] Maintenance of the oil field and the production equipment on the sea bottom is a difficult task that is both time intensive and very expensive.
[0007] To perform this maintenance, special vessels are typically needed. Some of the special vessels are known as semi-submersibles and drill ships. These ships have a number of disadvantages. The main disadvantages are their low transit speeds and high daily running cost.
[0008] New builds or converted non-dedicated ships, so-called “well intervention vessels”, are increasingly being used to install equipment on the sea bottom and to perform maintenance. The main advantages of small ships are low running cost and acceptable transit speeds. The disadvantage is that these small ships tend to have bad motion characteristics. The small ships move a lot more compared to the bigger units thereby limiting their use to only “good weather windows”.
[0009] Well intervention involves everything from lowering a ROV to do a visual check to lowering entire production or maintenance units to the sea bottom and retrieving the units. During the intervention operation, units have to be moved over the deck of the vessel from and to storage areas, the moonpool, and maintenance areas. Often these units are big and heavy and handling them are difficult and dangerous tasks. Sometimes these modules are required to be stacked on top of each other prior to lowering them to the seabed. Often crewmembers have to work on elevated levels to be able to reach all parts of the units. Current practice is the use of man-riding winches. Again, this is both dangerous and time consuming. Many accidents have occurred with the use of man riding winches.
[0010] Moving heavy objects also requires the use of cranes. Moving and lifting modules on a moving deck can be quite dangerous and numerous accidents have occurred during this kind of activities.
[0011] Apart from moving objects on the decks, lowering and lifting of the units through moonpools located in the vessel creates some specific problems. When lowering units through the moonpool, the objects tend to swing form side to side. Considerable risk of damage to the unit or the vessel arises when the modules are not constrained in some way.
[0012] Retrieving objects through the moonpool is equally dangerous. The relative motion of the vessel and the modules can be such that there is also the danger of the module hitting the vessel and thereby endangering the vessel and the lives for the crew.
[0013] According to prior art, standard drilling derricks are used in well intervention. The standard drilling derricks have an inverted U shape to lower to and lift objects of the seabed. This shape severely limits the size of the modules that can be handled since every module has to pass through the V-door of the drilling derrick. The two vertical support structures on most standard vessels severely limit the area that can be reached by other cranes and equipment of the vessel.
[0014] Due to the construction of the drilling derricks, the drilling derricks must be placed at specific locations in order not to hinder other equipment. This restriction limits the freedom in the design of the vessel considerably. Also, removing the drilling derrick from the vessel when it is not used is a difficult task due to the size and the weight of the drilling derrick.
[0015] A need, therefore exists for a module handling system for a well intervention vessel that can be removable mounted on a vessel; has a large freedom of placement on the vessel; does not claim a large working space; can safely move heavy and large objects around the deck; can lower and retrieve modules from the seabed through the moonpool; allows work on the modules on elevated levels safely; and allows modules to be placed on the seabed accurately.
[0016] The object of the current invention is to address the problems in the prior art and provide a tower for a monohull with a substantially hollow mast and at least one hoisting device.
SUMMARY OF THE INVENTION
[0017] The invention is a monohull vessel with moonpool capable of being used offshore. The monohull vessel has moonpool, equipment handling system removably mounted on the vessel and a movable hatch installed on top of the moonpool. The monohull vessel also includes a hoist system installed inside the vessel as well as a multipurpose tower mounted on the vessel.
[0018] The invention is a moveable hatch having a main structure and a set of movable fenders mounted in the main structure adapted to absorb shock. The movable hatch also has a set of hatches mounted on the top of the main structure and a hatch moving system mounted on the side of the main structure connected to the set of hatches.
[0019] The invention is a multipurpose tower with a mast comprising a mast top side, a mast bottom side, a mast forward side, and a mast back side. The tower has a plurality of cable blocks connected to the mast top side. The tower also has a main trolley with a first gripper and an auxiliary trolley with a second gripper moveably connected to the mast forward side. The tower next has at least one main hoist connected to the mast and at least one secondary hoist connected to the mast and the auxiliary trolley adapted to move the auxiliary trolley relative to the mast. Finally, the tower has a hoisting cable connected to the at least one main hoist adapted to be guided over the plurality of cable blocks and adapted to move the main trolley relative to the mast.
BRIEF DESCRIPTION OF THE DRAWINGS
[0020] The present invention will be explained in greater detail with reference to the appended Figures, in which:
[0021] [0021]FIG. 1 depicts a side view of a vessel with a module handling system installed;
[0022] [0022]FIG. 2 depicts a top view of a vessel with module handing system installed;
[0023] [0023]FIG. 3 depicts a top view of a vessel with multipurpose tower in another direction;
[0024] [0024]FIG. 4 depicts a top view of a working platform;
[0025] [0025]FIG. 5 depicts a perspective view of a working platform;
[0026] [0026]FIG. 6 depicts a side view of an auxiliary trolley;
[0027] [0027]FIG. 7 depicts a side view of a main trolley;
[0028] [0028]FIG. 8 depicts a side view of a multipurpose tower;
[0029] [0029]FIG. 9 depicts a detailed view of a mast head of a multipurpose tower;
[0030] [0030]FIG. 10 depicts a top view of a moveable hatch;
[0031] [0031]FIG. 11 depicts a detailed top view of a moveable hatch;
[0032] [0032]FIG. 12 depicts a side view of a moveable hatch;
[0033] [0033]FIG. 13 depicts a top view of two hatches with rails; and
[0034] [0034]FIG. 14 depicts a side view of the rail system.
[0035] The present invention is detailed below with reference to the listed Figures.
DETAILED DESCRIPTION OF PREFERRED EMBODIMENTS
[0036] Before explaining the present invention in detail, it is to be understood that the invention is not limited to the particular embodiments herein and it can be practiced or carried out in various ways.
[0037] The object of the invention is to provide a module handling package wherein the above-mentioned drawbacks are avoided at least to a considerable extent.
[0038] Now and with reference to the Figures, FIG. 1 shows a side view of a vessel ( 7 ) on which a multipurpose tower ( 1 ) is mounted on deck ( 10 ). As an example, a “Knuckleboom” Crane ( 3 ) is mounted on the vessel ( 7 ). The “Knuckleboom” crane ( 3 ) can be used to pick up equipment and tools from the quay and load them onto the vessel.
[0039] The multipurpose tower ( 1 ) is located next to moonpool ( 9 ). The first trolley guiding rail ( 13 ) and second trolley guiding rail ( 14 ) are connected to the front of multipurpose tower ( 1 ) and run into moonpool ( 9 ) to the bottom ( 8 ) of the vessel ( 7 ). In this embodiment, the main trolley ( 29 ) and auxiliary trolley ( 27 ) can move from the top side ( 113 ) of the multipurpose tower ( 1 ) to the bottom ( 8 ) of the vessel ( 7 ). The main trolley ( 29 ) and auxiliary trolley ( 27 ) can be connected to module ( 5 ) while module ( 5 ) is lowered into moonpool ( 9 ). This connection prevents any free movement of module ( 5 ) while the module ( 5 ) is being hoisted of lowered into of from moonpool ( 9 ).
[0040] When the module ( 5 ) reaches bottom ( 8 ) of vessel ( 7 ), both trolleys disconnect. Since the module is now under water level ( 123 ), the motions of module ( 5 ) are considerably reduced thereby reducing the risk of module ( 5 ) hitting first side wall ( 125 ) or second side wall ( 126 ) of the moonpool. The module ( 5 ) has to be lowered only a small distance in order for the module ( 5 ) to clear from vessel ( 7 ) completely.
[0041] Continuing with FIG. 1, the skid cart ( 111 ) is secured to the sub-sea module ( 5 ). The storage area ( 117 ) is fixably mounted on side ( 115 ) of multipurpose tower ( 1 ). The storage area ( 117 ) holds, in this particular embodiment, a riser ( 119 ), but the storage area is not limited to risers only. Other equipment such as hoses, drill pipe, and casing can be stored in the storage area ( 117 ).
[0042] [0042]FIG. 1 also shows that the centerline ( 129 ) of multipurpose tower ( 1 ) coincidences with centerline ( 131 ) of moonpool ( 9 ). Even though this is preferred embodiment, other arrangements of the multipurpose tower ( 1 ) in relation to the moonpool ( 9 ) are also possible.
[0043] [0043]FIG. 2 depicts a top view of deck ( 10 ) of vessel ( 7 ). The multipurpose tower ( 1 ) is located next to moonpool ( 9 ) in such a way that first and second trolley guiding rails ( 13 and 14 ), which are not visible in FIG. 2, run directly from topside ( 113 ) of the multipurpose Tower ( 1 ) to the bottom ( 8 ) of vessel ( 7 ).
[0044] The first hatch ( 23 ) and second hatch ( 21 ) are visible in FIG. 2. The first hatch ( 23 ) and second hatch ( 21 ) can move over deck ( 10 ) in directions indicated with A and B respectively. The movement of first hatch ( 23 ) and second hatch ( 21 ) respectively is always perpendicular to second multi purpose centerline ( 133 ) of multipurpose tower ( 1 ). This movement is needed because otherwise the hatches would collide with the multipurpose tower.
[0045] Also in FIG. 2, the module ( 5 ) can be moved over deck ( 10 ) of vessel ( 7 ) with the aid of transversal push-pull unit ( 17 ) and longitudinal push-pull unit ( 19 ). The transversal push-pull unit ( 17 ) moves over skid rail topside ( 91 ) while the longitudinal push pull unit ( 19 ) moves inside longitudinal skid rails ( 101 ). By using the longitudinal push pull unit ( 19 ) and transversal push pull unit ( 17 ), the module ( 5 ) can be moved over the whole area of deck ( 10 ) provided that a multitude of longitudinal skid rails ( 101 ) and transversal skid rails ( 103 ) are installed.
[0046] The skid cart ( 111 ), not visible in FIG. 2, can be secured to the module ( 5 ). The skid cart ( 111 ) skids over longitudinal skid rails ( 101 ) and transversal skid rails ( 103 ), which are removably mounted on deck ( 10 ).
[0047] [0047]FIG. 3 depicts a different placement of multipurpose tower ( 1 ) on vessel ( 7 ) in which first and second hatches ( 21 and 23 ) move perpendicular to the longitudinal axis ( 135 ) of vessel ( 7 ). The choice of placement of the moonpool ( 9 ) and multipurpose tower ( 1 ) is governed by operational and technical conditions.
[0048] Working on well intervention vessels is dangerous and demanding since the deck of the vessel is moving considerably in all directions. Bad weather and unfavourable wind and water conditions can increase the difficulty of the work. In addition, any motion of the well intervention vessel is amplified when working at elevated heights. On most vessels, crew members that have to work on elevated levels are being hoisted by so called “man riding winches”. The use of man-riding winches no matter how reliable they are has caused a large number of accidents often with deadly consequences.
[0049] [0049]FIG. 4 depicts an elevating working platform ( 31 ). The elevating work platform moves on the outside of multipurpose tower ( 1 ) over first rail ( 157 ), second rail ( 158 ), third rail ( 159 ), and fourth rail ( 160 ) and makes “man riding winches” superfluous.
[0050] The size of working platform ( 31 ) is such that it can pass the main trolley ( 29 ) and auxiliary trolley ( 27 ) without interference. The working platform ( 31 ) can pass the module ( 5 ), which is not shown in this FIG. 3, when it is being hoisted by main hoist ( 59 ). Movable plates ( 43 and 44 ) located on working platform ( 31 ) can move in the directions indicated with the letters F and G.
[0051] Often different modules have different sizes. In order to allow the crew to work on the modules in a safe and efficient matter, the movable plates ( 43 and 44 ) are adapted to move in order to minimize the gap between the modules and working platform ( 31 ). By minimizing this gap, crew members and tools are less likely to fall. An additional precaution to protect the crew working platform ( 31 ) can include fitting the elevating working platform ( 31 ) with a railing ( 151 ). In another embodiment, the elevating working platform ( 31 ) can be fitted with a wind wall or other protection devices.
[0052] [0052]FIG. 5 depicts a perspective view of elevating working platform ( 31 ). In order to move the crew and tools from deck ( 10 ) to elevating working platform ( 31 ), the elevating is hoisted to elevated levels. In this embodiment shown in FIG. 5, the auxiliary trolley ( 27 ) is being used for this purpose.
[0053] [0053]FIG. 6 depicts a side view of auxiliary trolley ( 27 ) in which first and second moving arms ( 47 and 48 ) are visible. Due to the parallelogram construction shown in FIG. 6 m any load that is picked up by the moving arms ( 47 and 48 ) does not rotate when the moving arms move outward. The moving arms can connect to a basket ( 153 ) to transport crew and equipment to working platform ( 31 ). The moving arms ( 47 and 48 ) can move inward in order to let auxiliary trolley pass main trolley ( 29 ) and module ( 5 ) without interference.
[0054] The auxiliary trolley ( 27 ) can also used to stabilize the module ( 5 ) when the module ( 5 ) is being hoisted or lowered. In this case, the moving arms move outward until a connection can be made with the module ( 5 ). The auxiliary trolley ( 27 ) moves on the inside of first and second trolley guiding rails ( 13 and 14 ) mounted on front side multipurpose tower ( 1 ). The auxiliary trolley ( 27 ) is guided ion the rails ( 13 and 14 ) by first and second wheel sets ( 50 and 51 ) which are fixably connected to auxiliary trolley main structure ( 49 ).
[0055] Continuing with FIG. 6, moving the moving arms ( 47 and 48 ) is accomplished by hydraulic cylinder ( 45 ). In this embodiment, the hydraulic cylinder ( 45 ) can be controlled in such a way that it can act as a damper. This dampening is advantageous when modules that are being hoisted in the moonpool have to be stabilized.
[0056] The stabilization is partly done by using the auxiliary hoist ( 27 ) by controlling the hydraulic cylinder ( 45 ) to act as a damper until movement of module ( 5 ) is decreased such that a fixed connection between moving arms ( 47 and 48 ) and the module ( 5 ) can be made. After the connection is complete, the moving arms ( 47 and 48 ) extend or retract to align the module ( 5 ) to multipurpose tower ( 1 ). Large forces can occur during the damping phase and the auxiliary trolley ( 27 ) has a relative heavy construction to cope with these forces.
[0057] [0057]FIG. 7 depicts a side view of main trolley ( 29 ). The main purpose of main trolley ( 29 ) is to center the main hoist wire ( 59 ) in order to prevent it from swinging and consequently to prevent the module ( 5 ) from swinging when hoisted. Centering the main hoist wire is accomplished by letting main hoist wire ( 59 ) to run through a fitting hole in main trolley ( 29 ). The main trolley ( 29 ) can move freely on rails ( 13 and 14 ) without interference with the auxiliary trolley ( 27 ) and working platform ( 31 ).
[0058] The ball weight ( 161 ) is used in hoisting the main trolley. The ball weight ( 161 ) is located at the end of the main hoist wire ( 59 ). The main hoist wire ( 59 ) connects to a catching cone ( 163 ) fixably mounted on main trolley ( 29 ). While the load is lowered into the moonpool, the main trolley ( 29 ) moves to bottom ( 8 ) of the vessel where it disconnects from the ball weight ( 161 ) while the load is lowered further. The shape of the ball weight ( 161 ) is such that the ball centers when it enters the catching cone ( 163 ) of the main hoist ( 29 ). This method ensures that no locking devices are necessary in this embodiment although operational demands could make additional locking of the ball weight ( 161 ) and catching cone ( 163 ) necessary.
[0059] [0059]FIG. 8 depicts a side view of multipurpose tower ( 1 ). The multipurpose tower ( 1 ) is mounted on the deck ( 10 ) of the vessel ( 7 ). The first and second trolley guiding rails ( 13 and 14 ) are mounted on front side ( 165 ) of multipurpose tower ( 1 ) and are also mounted on moonpool side wall ( 131 ). The rails ( 13 and 14 ) run to vessel bottom ( 8 ) making it possible for auxiliary trolley ( 27 ) and main trolley ( 29 ) to move from multipurpose tower top side ( 113 ) to the vessel bottom ( 8 ) through moonpool ( 9 ).
[0060] Multiple winches are located inside multipurpose tower ( 1 ). As seen in FIG. 8, these winches are the first winch ( 167 ), second winch ( 168 ), third winch ( 169 ), fourth winch ( 170 ), and fifth winch ( 171 ). The winches are installed at a low elevation level creating the advantage of a lower centre of gravity of the vessel.
[0061] The winches ( 167 , 168 , 169 , 170 and 171 ) are used to hoist auxiliary trolley ( 27 ), working platform ( 31 ), and a plurality of wires. Of the plurality of wires, FIG. 8 depicts three: first wire ( 175 ), second wire ( 177 ) and fourth wire ( 179 ). The wires can be connected to the module ( 5 ) and are lowered with the module ( 5 ) to the sea bottom.
[0062] The wires ( 175 , 177 and 179 ) run from the third winch ( 169 ), the fourth winch ( 170 ), and the fifth winch ( 171 ) to the first compensation system ( 181 ), the second compensation system ( 183 ), and the third compensation system ( 187 ), respectively. The wires are run over a multitude of sheaves located in masthead ( 191 ).
[0063] Between the winches ( 167 , 168 , 169 , 170 and 171 ) and the module ( 5 ), heave compensation systems can be installed. FIG. 8 shows two of those heave compensation systems ( 181 and 183 ). The heave compensation systems ( 181 and 183 ) are fixably mounted to multipurpose tower ( 1 ) near multipurpose tower top side ( 113 ).
[0064] As seen in FIG. 8, nearby the heave compensation systems ( 181 and 183 ), a first and a second pressure vessel ( 197 and 199 ) are fixably mounted to multipurpose tower ( 1 ) and connected to said heave compensation systems. The number of pressure vessels does not need to be the same as the number of heave compensation systems.
[0065] The main hoist wire ( 59 ) runs from the inside of the vessel ( 7 ) to the inside ( 193 ) of multipurpose tower ( 1 ), over the first sheave ( 195 ), and the over the second sheave ( 196 ). The first sheave ( 195 ) is fixably connected to masthead ( 191 ) while the second sheave ( 196 ) is rotably fixed to masthead ( 191 ).
[0066] A ladder ( 199 ) is connected to the masthead ( 191 ) to make it possible for the crew to move from the elevating working platform ( 31 ) onto the masthead ( 191 ) in a safe and orderly manner. This ladder is advantageous because large pieces of equipment can now be transported to the masthead without the restrictions of the limited space and the crew does not need to climb a large number of stairs or ladders to reach the masthead ( 191 ). Also seen in FIG. 8, the riser storage ( 117 ) is fixably connected to multipurpose tower ( 1 ) with a riser ( 119 ) located in the storage.
[0067] [0067]FIG. 9 depicts the masthead ( 191 ) with optional positions for the sheave ( 196 ). The sheave ( 196 ) is rotably connected to masthead ( 191 ). In the first position (denoted with the roman capital I), the main hoist wire ( 59 ) runs directly to module ( 5 ). In the second position (denoted with the roman capital II), the main hoist wire runs from the sheave ( 196 ) to the third sheave ( 201 ) that is connected to the ball weight ( 161 ) and then connected to the masthead ( 191 ). In sheave position II, a heavier load can be hoisted compared to sheave position I although at a lower speed. Changing from position I to position II is relatively easy and takes little time. The advantage is that with the same multipurpose tower now has a wide range of loads that can be hoisted safely.
[0068] [0068]FIG. 10 depicts a top view of the first hatch ( 23 ) located next to the moonpool ( 9 ). The first hatch ( 23 ) and the second hatch ( 21 ) are in a preferred embodiment identical in construction. The first hatch comprises a first structural beam ( 207 ) and a second structural beam ( 208 ) fixably connected to each other that can be moved in direction A by a first and a second hydraulic cylinder ( 203 and 204 ). The cylinders are connected on one side to the deck ( 10 ) of the vessel ( 7 ) and to the first hatch ( 23 ).
[0069] Also visible in FIG. 10 is the fender ( 222 ). The fender ( 222 ) cane can move in the direction denoted as “A”. The fender ( 222 ) is connected with hydraulic cylinders ( 232 and 234 ) to the structural frame ( 207 ). The fender ( 222 ) is located on the side that is oriented to the center of the moonpool ( 9 ). The fender ( 222 ) can be moved in three ways: by moving structural frame ( 207 ), by extending or retracting hydraulic cylinders ( 232 and 234 ) while structural frame ( 207 ) is not moving, and by moving both the structural frame ( 207 ) and hydraulic cylinders ( 232 and 234 ).
[0070] The hydraulic cylinders can be controlled to act as shock dampers. When the module ( 5 ) is hoisted into the moonpool ( 9 ) the movements of the module have to be minimized in order to prevent damage to the moonpool. This minimizing of movements is done by moving the second hatch ( 21 ) and the first hatch ( 23 ) simultaneously to the center of moonpool ( 9 ) with the fenders fully extended and damping out any excess movement of module ( 5 ).
[0071] The fender ( 222 ) includes a shock absorbing material to minimize impact damage. In a preferred embodiment this material is wood or rubber but other materials can be used as well. Once the module ( 5 ) is stationary the auxiliary trolley ( 27 ) can dampen out the remaining movements of the module ( 5 ).
[0072] Often the modules are lowered to the seabed. Lowering the modules to the seabed requires a power supply or other services from the vessel to function properly. Another module can be lowered on top of the first module already installed on the sea bottom. In order to guide any extra modules, wire guides are used to guide the modules to the correct place without the need for alignment from a ROV. These wire guides run from the module on the sea bottom through the moonpool to the top of the multipurpose tower in this specific embodiment. Up to seven wires and two umbilical wires can be run down at the same time.
[0073] When a new module is lowered to the seabed first, the module has to be connected to the guide wires. Sometime the module is of a size that the module cannot move without interference between the wires. In this case, the wires have to be moved apart to create the space needed for passage of the new module. Another problem that occurs is that the movement of the vessel causes the wires to move inside the moonpool of the vessel thus making it difficult to catch and secure the wires. All above mentioned actions and functions have to be incorporated in the moving hatches.
[0074] [0074]FIG. 11 depicts a detail of the first hatch ( 23 ) with first and second secondary hatches ( 303 and 305 ) movably mounted. The first and second wire catching systems ( 307 and 309 ) are located on the first and second secondary hatches. The purpose of the catching systems is twofold: gripping the wires and moving the wires. The purposes are accomplished by a gripping system ( 311 ) mounted on first secondary hatch ( 303 ) that can move in direction indicated by the capital “K” in the figure by a hydraulic cylinder ( 313 ). Likewise, a gripping system ( 315 ) is mounted on second secondary hatch ( 305 ).
[0075] [0075]FIG. 12 depicts a side view of the first hatch ( 23 ) on which first secondary hatch ( 303 ) is visible in the open position and the second secondary hatch ( 305 ) is visible in the closed position. In the open position of secondary hatches ( 303 and 305 ), the secondary hatches do not interfere with the stabilization procedure of the module ( 5 ) using the fenders. In the closed position, secondary hatches form a safe working platform over the moonpool. The first hatch moving system ( 203 ) and the second hatch moving system ( 204 ) are visible in FIG. 12. In a preferred embodiment, these systems are hydraulic cylinders, but other moving systems can be used as well. The first hatch ( 23 ) slides on rails indicated by numbers ( 331 and 333 ).
[0076] When the multipurpose tower ( 1 ) is oriented on the vessel ( 7 ) as indicated in FIG. 3, the rails in which longitudinal push-pull unit ( 19 ) moves can be an integral part of the movable hatches. Once the hatches are fully opened, the moonpool ( 9 ) is completely cleared. If the multipurpose tower ( 1 ) is orientated as indicated in FIG. 2, the rails are not an integral part of the movable hatches.
[0077] [0077]FIG. 13 depicts the first and second rails ( 345 and 347 ) that slide over first hatch ( 23 ) moved by first rail cylinder ( 349 ) and the second rail cylinder ( 351 ). The first rail ( 345 ) and the second rail ( 347 ) move in the same direction as the first hatch ( 23 ) indicated in the figure by letter “A”. The first rail ( 345 ) is shown in a fully retracted position while the second rail is shown in fully extended position.
[0078] The third rail ( 351 ) and the fourth rail ( 353 ) can slide over second hatch ( 21 ) moved by third rail cylinder ( 355 ) and fourth rail cylinder ( 357 ). The third rail ( 351 ) and fourth rail ( 353 ) move in the same direction as the second hatch ( 21 ) as indicated by in the figure by the letter “B”. The third rail ( 351 ) is shown in a fully retracted position while the fourth rail is shown in a fully extended position.
[0079] When the all of the rails are in a fully retracted position, the moonpool ( 9 ) is completely cleared. When first rail ( 345 ), second rail ( 347 ), third rail ( 351 ) and fourth rail ( 353 ) are fully closed, the longitudinal push-pull unit ( 19 ) can move over the moonpool ( 9 ) to transport the module ( 5 ) to the centerline of the moonpool ( 9 ) or to the other side of the moonpool ( 9 ).
[0080] In FIG. 12, the first rail ( 345 ), the first rail cylinder ( 349 ), the second rail cylinder ( 351 ), and the second rail ( 347 ) are also visible.
[0081] [0081]FIG. 13 depicts a side view of the transversal rail ( 103 ) and a cross view of longitudinal rail ( 101 ). In this specific embodiment, the transversal push-pull unit ( 17 ) is moving on the top side of rail ( 103 ) while the longitudinal push-pull unit ( 19 ) is moving inside longitudinal rail ( 101 ). The transversal push-pull unit can slide over the topside of longitudinal push-pull unit as indicated by the reference numeral 401 and is able to pass over the longitudinal rail ( 101 ).
[0082] The moving system to move the longitudinal push-pull unit ( 101 ) is well known from previous art. Both the longitudinal push-pull unit ( 101 ) and the transversal push-pull unit ( 103 ) are fitted with locking devices indicated by reference numerals 405 and 407 to prevent the module ( 5 ) from moving in unwanted directions. The power to drive the push-pull units in a preferred embodiment is delivered by a central power unit. Each push pull unit can be fitted with an independent power unit as well.
[0083] The invention is by no means limited to the exemplary embodiment described herein above, but comprises various modifications hereto, in so far as they fall within the scope of the following claims.
[0084] This invention contemplates methods using the module handling package described herein.
[0085] The invention contemplates a method for catching and stabilizing sub sea equipment in a moonpool. The method begins by hoisting equipment from the sea bottom into the moonpool and catching the lifting hook using the main trolley located at the bottom of the moonpool. The next steps include further hoisting the equipment into the moonpool together with the main trolley and stabilizing the equipment in one direction by using two movable hatches. The method ends by stabilizing the equipment in a direction perpendicular to the first direction by using an auxiliary trolley with movable arms and lifting the stabilized equipment into the multipurpose tower together with the main trolley and the auxiliary trolley.
[0086] The invention contemplates a method for lowering equipment through the moonpool to the sea bottom. The method begins by skidding the equipment on the movable moonpool hatches by using the transversal and longitudinal push pull units and then connecting the lifting wire and the guiding wires to the equipment. The next steps include connecting the auxiliary trolley to the equipment and hoisting the equipment by using the main hoist. Next, the method includes moving the longitudinal push-pull unit and the skid carts out of the way and clearing the moonpool by moving the movable hatches to the sides of the moonpool.
[0087] The method for lowering equipment through the moonpool to the sea bottom continues by lowering the equipment together with the auxiliary trolley and main trolley into the moonpool and disconnecting the main trolley and the auxiliary trolley when the equipment has reached the bottom of the moonpool. The method ends by lowering the equipment to the sea bottom, hoisting the auxiliary trolley out of the moonpool, and closing of the movable hatches.
[0088] The invention contemplates a method for handling suction piles. The method begins by skidding of the suction pile in horizontal position to the centerline of the moonpool, connecting the suction pile to the main hoist and any umbilical cables, and hoisting the suction pile to a vertical position by the main hoist. The method continues by connecting the auxiliary trolley to the suction pile, moving the longitudinal push-pull unit and the skid carts out of the way, and clearing the moonpool by moving the movable hatches to the sides of the moonpool.
[0089] The method for handling suction piles continues by lowering of the suction pile into the moonpool, disconnecting the auxiliary trolley and the main trolley when suction pile reaches the bottom of the moonpool, and lowering the suction pile to the sea bottom. The method ends by hoisting the auxiliary trolley out of the moonpool and closing the movable hatches.
[0090] The invention contemplates a method for handling ROV's. The method begins by skidding the ROV with catching basket to the centerline of the moonpool, connecting the ROV to the main hoist and the auxiliary hoist, and hoisting of the ROV. The method continues by moving the longitudinal push-pull unit and the skid carts out of the way, clearing the moonpool by moving the movable hatches to the sides of the moonpool, and lowering the ROV into the moonpool. The method ends by disconnecting the ROV from basket when the ROV reaches the bottom of the moonpool, hoisting the basket, and closing of the movable hatches.
[0091] The invention contemplates a method for catching and spreading wires running through the moonpool. The method begins by closing the movable hatches, stabilizing the wires with the movable fenders of the movable hatches in a first direction. The method continues by stabilizing the wires in a second direction perpendicular to a first direction by moving secondary hatches. The method ends by locking the wires in wire spreaders and spreading the wires.
[0092] The invention contemplates a method for handling equipment modules on the vessel. The method begins by locking the module to the transversal push-pull unit and moving the module over the transversal rail to the longitudinal rail by the push-pull unit. The method continues by skidding the longitudinal push pull unit, locking of longitudinal push-pull unit to the module, and unlocking of the transversal push-pull unit of the module. The last step of the method entails moving the module by the longitudinal push-pull unit in longitudinal direction of the vessel.
[0093] While this invention has been described with emphasis on the preferred embodiments, it should be understood that within the scope of the appended claims the invention might be practiced other than as specifically described herein.
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A vessel with moonpool capable of being used offshore comprising a monohull with moonpool; a multipurpose tower mounted on the vessel; an equipment handling system removably mounted on the vessel; a movable hatch installed on top of the moonpool; and a hoist system installed inside the vessel, as well as an improved multipurpose tower, a moveable hatch and modular features for the tower. The invention is also a moveable hatch and a multipurpose tower.
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This application claims benefit of U.S. provisional application No. 60/251,009, filed Dec. 5, 2000.
BACKGROUND OF THE INVENTION
THIS INVENTION relates to a game and game apparatus. It related in particular to a board game and apparatus therefor.
SUMMARY OF THE INVENTION
According to a first aspect of the invention there is provided a game which includes
means for establishing the nature of at least one pre-defined disaster to be prevented by players of the game; and
means obtainable by or accessible to said players, for preventing said disaster from occurring.
The disaster may be a disaster capable of threatening life on a selected planted, e.g. the Earth. Typically, the disaster is a disaster capable of threatening human civilisation as it is presently known on Earth. The disaster may be real or imagined. For example, the disaster may be selected from the group consisting of nuclear war, asteroid collision, volcano eruption, global warming, and alien invasion.
The means for preventing the disaster from occurring may include tokens, e.g. collectable cards, each card presenting at least one solution to said disaster. The number of solutions required to overcome the disaster may be determined in advance by a set of rules provided by the game, and may be determined with reference to the number of players of the game.
Preferably, although not necessarily, the game includes means for establishing a limited time within which players must prevent said disaster, before the disaster occurs. For example, the game may include a time-line or grid that is traversed by a counter in accordance with the outcome of consecutive throws of a dice, such that over the course of time the counter will reach the end of the time-line or grid to signify occurrence of the disaster. This feature of the game requires a player not only to play against other players but also against time.
Preferably, although not necessarily, the game is a board game and includes a playing board. The playing board may bear a schematic representation of a map of a planet, for example, the Earth. Preferably still, each continent of the map may be differently coloured. The board may bear representations of flight paths and airports, the flight paths being traversable by players' playing pieces or counters during play of the game thereby to reach the airports.
Thus, the board game may further include playing pieces or counters. In a preferred embodiment of the invention, each playing piece is differently coloured and the colour of each player's playing piece corresponds with the colour of a particular continent represented on the playing board.
The game may include means (e.g. cards) permitting players to obstruct the play of other players of the game; for example, it may include cards which empower a player to send opponents to other areas of the playing board (e.g. to the airports of different continents). It may further include means to permit players to take cards from opponents.
In a second aspect of the invention there is provided game apparatus for playing the game described above. The apparatus may include a playing board as described above. The apparatus may further include playing pieces as described above, disaster cards for presenting various disasters to be pre-defined and prevented during play of the game, solution cards for presenting solutions for preventing said disaster, problem cards for introducing problems encountered by players during play, destination cards for designating destinations for players to reach during play, landing cards required for landing at a particular destination airport during play, dice, and the like. Each solution card may present solutions for a limited number of the disasters only (e.g. for four out of five disasters) so that not every solution card will be effective as a solution to the prevailing impending disaster.
The game apparatus may include playing pieces or counters (referred to as “aircraft” herein), each of which comprises a base and a body portion shaped to resemble an aircraft. The apparatus may further include a playing piece or counter (referred to as a “disaster piece” herein) that comprises a base and a body portion shaped to resemble a question mark. The game apparatus may also include a customised dice bearing the following on its six faces: −1, +2, a green spot (two sides), a black spot, and an asterisk.
The invention will now be described by way of example with reference to the accompanying diagrammatic drawings, in which like reference numerals identify correspondingly throughout. The following specific description is of an embodiment of the invention which is in the form of a board game. However, it is to be understood that the game may similarly be presented in the form of a computer game, a game for a games console, or the like.
BRIEF DESCRIPTION OF THE DRAWINGS
In the drawings:
FIG. 1 shows, schematically, a plan of a playing board forming part of the game apparatus according to the invention.
FIGS. 2 & 3 show, respectively, the back and face of a disaster card forming part of the game apparatus according to the invention;
FIGS. 4 & 5 show, respectively, the back and face of a solution card forming part of the game apparatus according to the invention;
FIGS. 6 & 7 show, respectively, the back and face of a destination card forming part of the game apparatus according to the invention;
FIG. 8 shows the back of a landing card, while
FIGS. 9 to 11 show the faces of three different examples of landing cards forming part of the game apparatus according to the invention, including a ‘special card’(FIG. 11 );
FIG. 12 shows the back of a problem card, while
FIGS. 13 to 15 show the faces of three different examples of problem cards forming part of the game apparatus according to the invention;
FIG. 16 shows, schematically, a side elevation of a playing piece or counter having a body portion shaped to resemble an aircraft; and
FIG. 17 shows, schematically, a side elevation of a disaster piece, having a body portion shaped to resemble a question mark.
Referring to the drawings, reference numeral 20 indicates generally a playing board. The playing board 20 bears a schematic map of the world. The playing board is shown in monochrome. However, it is to be understood that different parts of the board are differently coloured in the preferred embodiment, as described below. In particular, each of the separate continents on the map of the world has a different colour. The playing board typically is of stiff card and may be adapted to be folded.
DESCRIPTION OF THE PREFERRED EMBODIMENTS
Reference numeral 22 indicates three adjacent spaces along just one of several flight paths making up a ‘flight path grid’. Reference numeral 24 is used herein to refer generally to the flight path grid. The flight path grid is represented on the board 20 by interconnected circular symbols which denote various flight paths to different airports (see below).
Reference numeral 26 indicates generally a ‘disaster piece grid’ represented by a chain of circular symbols commencing at a disaster piece starting space 28 and terminating at a symbol 30 (e.g. an explosion) representing the “End of the World”. The disaster piece grid serves as a means for establishing a limited time within which players must prevent said disaster, before the disaster occurs. The disaster piece grid 26 is a time-line or grid that is traversed by a counter (a “disaster piece”—see below) in accordance with the outcome of consecutive throws of a customised dice (not shown), such that over the course of time the counter will reach the end of the time-line or grid to signify occurrence of the disaster.
In FIG. 1 the disaster piece grid 26 may be distinguished from the flight path grid 24 by the darker shading of the former, although it is to be appreciated that on the actual playing board 20 the two grids are differently coloured.
Reference numeral 32 indicates an example of an airport. A holding area 34 can be seen surrounding the airport 32 . The holding area is divided into five segments and in addition to performing an aircraft holding function (discussed below) each segment may also be considered as a further connecting space along any two flight paths linked by the airport.
Reference numeral 36 indicates the airport of the United Nations headquarters, which is connected to the flight path grid by its own flight path 38 .
Players using playing pieces or counters traverse the flight path grid 24 . The playing pieces are typically in the form of “aircraft” 40 as illustrated schematically in FIG. 16 .
The disaster piece grid 26 is traversed by a playing piece dubbed a disaster piece 42 . The aircraft and the disaster piece are moved according to the outcomes of dice throws, and according to various rules and instructions contained on cards collected by players. These aspects of the game are discussed in more detail below.
In FIGS. 2 to 15 five types of cards used during play are shown. In these Figures, reference numeral 44 indicates means for establishing the nature of at least one pre-defined disaster to be prevented by players of the game. These means take the form of a disaster card. The card shown designates the disaster as “5. Global Warming”—other cards (not shown) designate other disasters. Only a single disaster card is played at the start of each game to establish the prevailing impending disaster for that game.
In this connection, particular attention should be drawn to one further aspect of the playing board 20 . Reference numeral 45 indicates one example of a space along a flight path having a symbol for a disaster and a corresponding number for that disaster. The function of these spaces 45 is explained in more detail below.
Reference numeral 46 indicates means obtainable by or accessible to players for preventing said disaster from occurring, in the form of solution cards. Possible solutions to four disasters are shown on each solution card. Use of the solution cards 46 is explained below.
Reference numeral 48 indicates a destination card; reference numerals 50 , 52 , 54 indicate problem cards; and reference numerals 56 , 58 , 60 indicate landing cards. The function and use of all these cards are explained in greater detail below.
The game apparatus also includes dice (not shown). One of the dice (Dice 1 ) is conventionally numbered 1 to 6 and is used for moving the aircraft 40 around the playing board 20 on the flight path grid 24 . The second of the dice (Dice 2 ) has one side bearing a black spot (requiring collection a problem card if thrown); two green sides (authorising collection of a landing card), a symbol (¤) to double the score on Dice 1 ; and two sides to move the disaster piece. One of these sides bears “+2” and moves the disaster piece two spaces on the grid 26 towards the End of the World symbol 30 . The other side bears “−1” and moves the disaster piece backwards to provide players with more time.
To begin the game each player selects a continent for which he will play. The aircraft 40 are placed on the chosen continents' airports 32 by matching the colour of each aircraft with the colour of each continent. The disaster piece 42 is placed on its starting space 28 . One player is elected as ‘Card Controller’.
Players are informed of the number of solution cards 46 required before they may proceed to the United Nations headquarters 36 in order to win the game: for 2 players—8 solution cards; for 3 players—6 solution cards; for 4 players—4 solution cards; for 5 players—3 solution cards.
The disaster cards 44 are shuffled and placed face down. One player then draws the top card to show all players what impending disaster is threatening the planet (e.g. alien invasion). The remaining disaster cards will not be required for the rest of the game.
Each player is then dealt one destination card 48 and one landing card to be kept hidden from other players. The remaining landing/destination/solution/problem cards are placed faced down by the Card Controller.
The first player to throw a six or the player with the highest throw then starts the game, i.e. starts travelling around the world, with play continuing clockwise from that player. Each player looks at their destination card and works out the shortest route to the corresponding airport.
The two dice are then thrown and the instructions on the coloured dice (Dice 2 ) are obeyed first. If a player's landing card has a special instruction on it (e.g. “Obtain one solution card from one player”, “U.N. immunity from any card”, etc.) the player can play the special instruction or choose to wait until a more suitable time.
A player takes off by moving their aircraft the correct number of places—as shown by a throw of the conventional dice (Dice 1 )—along a flight path towards their destination (as per the destination card issued at the start).
If another player's aircraft has landed at a player's destination airport first, blocking their landing, the blocked player is required to wait in the holding area surrounding that airport. No two aircraft can occupy the same space on the grids simultaneously; therefore, if a player lands on another player's space on the flight path grid he moves one space behind.
A player must be in possession of a landing card to be able to land at any airport except the United Nations. If a player does not have a landing card he must wait in the holding area of the airport concerned until he throws a green spot on Dice 2 .
Upon landing a player must show his destination card to the other players to confirm that it corresponds with the airport at which he is landing. It must then be returned face down to the pile of destination cards. The player must then redeem one landing card, which is either given to the player playing as the continent on which he has landed, or returned to the bottom of the pile of landing cards.
Having landed the player then picks up another destination card and one solution card. If the solution card bears a solution to the impending disaster then it is kept to form part of the required final number of solution cards. If not the player may hold it so that if he is required to give up a solution card this one may be given away instead of a correct solution card.
Then on his next throw the player takes the shortest route to his next destination. If he lands on a disaster symbol 45 along a flight path and this symbol corresponds with that of the disaster that is in play then he must hand in a solution card or miss a turn.
Once a player has collected the required number of solution cards he can make his way to the United Nations airport located in the North American continent. He must travel via its flight path 38 . Once he lands at the U.N. (exact throw not needed) he must show the other players the correct number of solution cards and declare that he has “Saved Planet”, thereby winning the game.
However, if he loses a solution card en route to the U.N. by picking up an adverse problem card, he must go to the airport of his current destination card and continue the game until he obtains a new solution card. Once he has replaced the lost card with a further card bearing a correct solution to the disaster he may proceed back towards the U.N.
Cards may be re-shuffled and re-used as necessary.
Meanwhile, the disaster piece travels towards its destination. If it reaches it before a player reaches the U.N. with the correct number of solutions the disaster will occur and the game will be over.
The following is an extract from a rule book for the embodiment of the game herein described, and is presented as a non-limiting clarification of the purpose and function of the various components of the embodiment and their functions:
Rule Book
Contents of the Game are:
1. MAP OF THE WORLD. Board with map of the World showing continents, flight paths (making up a “flight path grid”), airports, and a grid to the countdown to the End of the World (the “disaster piece grid”).
2. CARDS×82:
25 Solution cards
Yellow
25 Landing cards
Green
15 Destination cards
Blue
12 Problem cards
Purple
05 Disaster cards
Red
3. DICE×2
Dice 1:
Numbered 1-6 (to move your aircraft around the World)
Dice 2:
Three coloured sides: - one black side (to collect a problem
card) and two green sides (to collect a landing card); a
symbol (¤) to double the score on your dice; and two sides to
move the disaster piece: - “+2” to move the disaster piece two
spaces on the grid towards the End of the World and “−1” to
move the disaster piece back to give more time.
4. AIRCRAFT: Five diplomatic aircraft in colours corresponding to those of the continents.
5. DISASTER PIECE×1
Introduction
You are a diplomat with the highest honour that your continent can bestow upon its subjects. Your mission is to “SAVE YOUR PLANET” and civilisation from extinction. You have full diplomatic powers and can use whatever resources you have at your disposal to complete the United Nations'objective and continue our way of life.
The New Millennium is Here . . . But is Our Planet Safe?
Tactics
Use your skills as a diplomat to outwit others. Plan your strategy, bluff your opponent or play a ‘special card’to defend your position and change the game plan.
Can you SAVE YOUR PLANET from impending doom?
There are five disasters which can threaten the planet EARTH:
1. ALIEN INVASION
2. AN ASTEROID ON COLLISION COURSE WITH EARTH
3. NUCLEAR WAR
4. VOLCANOES
5. GLOBAL WARMING.
. . . but remember that you are racing against time!
Object of the Game
The object of the game is to be the first player to prevent one of the impending disasters from occurring and SAVE YOUR PLANET.
The Game in General
Each player has a continent chosen from one of the five different continents.
1.
Europe
Blue Aircraft
2.
North America
Red Aircraft
3.
Asia
Purple Aircraft
4.
Africa
Green Aircraft
5.
Australasia
Yellow Aircraft
The players must then fly around the World collecting Solution Cards (SCs) as they go (the number of players determines the number of SCs required). Having collected the required number of cards a player must fly to the U.N. to declare that they have SAVED THE PLANET and thereby declare themselves the winner. However, a player can only do this provided that the disaster piece has not already completed its journey.
Players must travel in one direction only, except when on the flight path to the U.N. If a player is unfortunate enough to lose a Solution Card on this route, leaving him short of the number required, and has no Immunity Card (described in Landing Cards below), then he will be forced back to an airport to obtain another SC before returning to the U.N.
Meanwhile, the disaster piece is moving towards the End of the World and other players are desperately trying to fly to the U.N. first.
Cards and Their Use in the Game
Destination Cards
Of the fifteen Destination Cards there are three for each airport. One Destination Card is dealt to each player at the start of the game. Upon landing at the airport, your Destination Card (DC) should be revealed (along with a Landing Card). The DC card is then placed at the bottom of the relevant DC pack and a new DC issued to the player. This card will show the player their new airport to fly to, which may be on the opposite side of the World. Note: (Destination Cards are not redeemed/issued when a player is by-passing an airport).
If the DC indicates that the next destination is the airport at which you are already then a BONUS is acquired. On your next turn, instead of moving towards another airport you can throw the dice, obey the instruction on Dice 2 , reveal your DC and collect a Solution Card, without using another Landing Card or indeed moving.
Landing Cards
Issued each time a green is thrown on Dice 2 . The Landing Card (LC) can have two purposes: 1) to enable a player to obtain a Solution Card on arriving at a destination airport; and/or 2) to impede an opponent and increase your own chances of SAVING OUR PLANET (unless a U.N. Immunity Card is played—see Landing Card descriptions).
Landing Cards and their uses are outlined below:
“Permission to land granted”:—a basic landing card—submit on arrival at destination airport to obtain Solution Card from pack.
“Permission to land granted plus obtain one solution card from one player”:—submit on arrival at destination and collect one Solution Card from main pack AND collect an additional Solution Card from any player.
“Fly direct and land at any airport or wait in holding area except U.N. (holder only). If necessary move opponent out of airport into holding area”:—this card can be played on your turn at any time during the game and enables the holder to land at any destination airport or holding area. Upon landing you collect a Solution Card from the pack.
“Special card—move one player to holding area of any airport except U.N.—Not holder of card”:—this can be played on your turn at any time during the game and enables the holder to move any player to any airport holding area (except the U.N.) to the player's disadvantage. This card cannot be used to land.
“Permission to land granted plus U.N. immunity from any card”:—a very important card which can be played at any time. Superior to all cards and used to reject any ‘special card’ instruction played against you.
A Landing Card must be submitted on arrival at each destination airport. If the pack of Landing Cards runs out and you have thrown a green on Dice 2 you may collect a LC off any opponent—unless a U.N. Immunity Card is played by them.
Solution Cards
Issued on arrival at each destination on the submission of a Landing Card or playing of a ‘special card’—(see Landing Card descriptions).
On each Solution Card there are correct solutions for four out of five of the possible disasters. If the card shows a corresponding number and symbol to that of the disaster you are trying to prevent then you will be presented with a solution for the impending disaster. For example, if the disaster is No.1 (Alien Invasion) then on your Solution Card you look for the solution appearing alongside the number “1” and the relevant symbol:
However, you may collect incorrect Solution Cards to bluff players as to the number of Solution Cards you are holding or collect them to give to another player if they request a Solution Card from you.
Problem Cards
You must pick up a problem card when you throw a black spot on Dice 2 .
If you have to collect a problem card you must obey its instructions before moving. If the instruction sends you to another player's airport then you do not have to give up a Landing Card. Only a U.N. Immunity Card can be used to stop a problem card. Once the card has been used place it at the bottom of the pack.
If you are moved with a problem card to an airport which is hosting another player, then you must move that player out into the holding area so that you can land.
The following are examples of problems presented by the problem cards:
“Move to closest airport”(if a player is at an airport this can be ignored);
“Move back 2”(if a player is at an airport and throws a one or a two then he stays in the airport);
“Lose one solution”(if a player has no solution card he misses a turn);
“Move to North Pole”;
“Move to South Pole”; etc.
Disaster Piece
The disaster piece travels on its own grid (the “disaster piece grid”) which crosses three flight paths. If, while crossing the players' grid (i.e. the flight path grid) it lands on top of a player's aircraft, then that player must move back one space (or to the next available space backwards) and hand in one Solution Card. If you have no Solution Card miss two turns. Remember that you can only fly in one direction. If your throw means that you have to move directly into the path of the disaster piece, then that is just bad luck. However you can fly over the disaster piece. Bear in mind that the disaster piece can move forwards or backwards so it may intercept you more than once. You cannot travel on the disaster piece grid.
If at the start of the game a player throws a “−1”(move back one space) for the disaster piece but the disaster piece is still on its starting point then it stays where it is.
If the disaster piece travels to its destination before a player reaches the UN with the required number of solutions the prevailing disaster occurs and the game is lost.
Additional Notes
You can hold any number of Solution or Landing Cards, but only one Destination Card at a time.
On the players' flight path grid there are various symbols of the disasters, which threaten the aircraft. If you land on one of these and it corresponds with the disaster that you are trying to prevent then you must hand in one Solution Card (miss a turn if you do not have a Solution Card). If you land on a symbol which does not relate to the disaster in play, then you take no action and the game continues.
While en route you must obey the instructions on the coloured dice (Dice 2 ) first, i.e. you may collect a problem card as described earlier.
AIRSPACE—If you land at another player's airport you must give that player the Landing Card as you have entered their airspace. If a problem card moves you to this airport then no Landing Card needs to be surrendered. You cannot use a U.N. Immunity Card against this rule. However if you land at your own airport you are required to surrender one LC to the pack.
Once you have collected the correct number of Solution Cards you may proceed to the U.N. However, it is necessary to collect a Destination Card for two reasons, viz. 1) to prevent other players from knowing that you are en route to the U.N., and 2) in case you lose a Solution Card on the way and have to fly to that airport to replace a correct SC.
To win you must land at the United Nations (exact throw not needed and no Destination/Landing Card required). Once arriving and claiming the win you must reveal your correct Solution Cards to all the players.
AIRPORTS AND HOLDING AREAS—There are five holding area spaces which surround each airport, except the U.N. airport. You can fly around any airport on the way to your destination without incurring any penalty.
The inventor believes that the game as described herein has various advantages. The inventor is of the view that many people are intrigued by potential catastrophes and by ideas on how to solve them. The inventor believes that interest and enjoyment of the game accordingly arises since the object of the game is the overcoming of a planet-threatening disaster. The inventor is also of the view that interest and enjoyment is fostered by the fact that players compete “against the clock” since only a limited time is available for preventing the disaster. Thus there may be no outright winner of a particular game.
The inventor believes that the game fosters enjoyment in that it presents various opportunities for strategic and tactical play. The game may be played in different ways and each game may be different depending upon the personality-types of the players. The inventor also considers that in certain circumstances the game may give rise to amusing psychological reactions from players. For example, the inventor has noted that alliances sometimes form between players to obstruct the activities of any player who appears to be winning the game, the alliance preferring to permit the disaster to happen rather than to allow the winning player to succeed.
Finally, the inventor also believes that there are educational aspects of the game. The layout of the board to represent a map of a planet, e.g. the Earth, can communicate aspects of geography. Furthermore, the game may educate players in the various disasters which may in fact or in fiction threaten humanity on this planet, as well as putative solutions to them.
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A game and a method of playing a game provide for a way to establish one among a plurality of disasters to be prevented by players as well as a variety of ways to prevent the predetermined disaster from occurring. In one embodiment, the disaster is represented by disaster cards and players move tokens around a game board from one airport to another collecting other types of cards in an attempt to be the first to prevent the predetermined disaster from occurring. There may also be provided a mechanism to enforce a time limit within which the disaster must be prevented for there to be a winner.
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BACKGROUND OF THE INVENTION
1. Field of Invention
The present invention relates to an installation in a stepper machine for microlithographic processing of semiconductors. More particularly, the present invention relates to a method and a controlling system for preventing the scratching of wafer backs by the fetch arm of a stepper machine.
2. Description of Related Art
FIG. 1 shows wafer holders and part of the structural components of the transporting system of a conventional stepper. The suction head of a fetch arm 110 picks up a wafer 130 on the side sliding arm 120, transports it to a cassette holder 100, and then unloads the wafer 130. All through the transportation, the wafer 130 is held by a vacuum in the suction head, until the wafer has dropped inside the cassette holder 100.
For the above transporting system, there is one major drawback. As the fetch arm 110 moves from position A1 to A2 toward the cassette holder 100, there is a possibility that the wafer 130 may hit the side of the cassette holder 100, causing the wafer 130 to be slightly displaced from the fetch arm 110. Therefore, the contacting area between the back of the wafer and the suction head may be scratched.
FIG. 2 is a block diagram of a controlling circuit for controlling the movement of the fetch arm of a conventional stepper. FIG. 3 is a time diagram for the sequence of actions associated with the movement of a fetch arm in a conventional stepper.
As shown in FIG. 3, the operation of a stepper is roughly divided into three operational stages, namely, picking up a wafer from a cassette holder, performing some microlithographic projections, and returning the wafer to the cassette holder. The fetch arm has three action states, namely, a forward state, a retracting state and a stationery state. The suction head of a fetch arm has two states, namely, a vacuum-release state (a non-vacuum state) and a vacuum-hold state (a vacuum state).
Microlithographic projections may also include other subsidiary steps. Since these steps are not a major concern of this invention, detailed description of their operations is omitted. The relevant issues of this invention are the operation of unloading wafers from the cassette holder to the stepper and returning the wafers from the stepper back to the cassette holder. In particular, the main concern is the operation of returning the wafers to the cassette holder because here is when the wafer back may be scratched. Therefore, controlling actions related to the returning of wafers to the cassette holder are described in detail below with reference to FIGS. 1-3.
The fetch arm controlling system of a conventional stepper includes a first sensor 200, a second sensor 210, an input interface 220, a microcontroller 230, an output interface 240 and a vacuum solenoid valve 250.
The first sensor 200 and the second sensor 210 are used for sensing the position of the fetch arm 110. The first sensor 200 senses whether the fetch arm 110 is in position A1, then generates a first sensor signal S start accordingly. If the fetch arm 110 is in position A1, a logic high output signal will be generated. On the other hand, if the fetch arm 110 is not in position A1, a logic low output signal will be generated. For example, at time t2, the fetch arm 110 starts to move away from position A1, a logic high signal appears in S start , and at time t6, the fetch arm 110 has returned to position A1, so a logic low signal reappears in S start .
The second sensor 210 senses whether the fetch arm 110 is in position A2, then generates a second sensor signal S stop accordingly. If the fetch arm 110 is in position A2, a logic low output signal will be generated. On the other hand, if the fetch arm 110 is not in position A2, a logic high output signal will be generated. For example, at time t3, the fetch arm 110 has moved to position A2, a logic low appears in Sstop; and at time t5, the fetch arm 110 starts moving away from position A2, so a logic high reappears in S stop .
As shown in FIG. 2, the microcontroller 230 is a device for receiving the first sensor signal S start , and the second sensor signal S stop , and then outputting a first control signal S c . The first control signal S c controls the opening or closing of the vacuum solenoid valve 250. The vacuum solenoid valve 250 in turn controls the action of releasing the vacuum or holding the vacuum in the suction head of the fetch arm 110.
FIG. 3 illustrates the steps involved in returning a wafer 130 to a cassette holder 100. First, at time t1, a vacuum is created in the suction head of the fetch arm 110 before the fetch arm starts moving away from position A1 at time t2. At time t3, the fetch arm arrives at position A2 and stops. At time t4, the vacuum in the suction head is released. Hence, during the period from time t1 to t4, the suction head of the fetch arm 110 is in a vacuum state. In other words, wafer 130 is held firmly by the suction head of the fetch arm all through its forward journey. A major drawback for this controlling system is that, should the wafer 130 hit the side of the cassette holder 100 during the forward journey of the fetch arm from position A1 to A2, the wafer 130 may be forced to displace slightly. If the wafer is free to move, there will be no problem. However, since the wafer is held firmly by the suction head through a vacuum, the contacting area between the back of wafer and the suction head may be scratched.
In light of the foregoing, there is a need in the art for preventing the scratching of wafer backs by the fetch arm of a stepper.
SUMMARY OF THE INVENTION
Accordingly, the present invention is directed to improving the operation of the fetch arm of a conventional stepper by avoiding the scratching of wafer backs during the transportation of wafers from the stepper to the cassette holders. In another aspect, this invention is directed to providing a controlling system for controlling the operation of the fetch arm that avoids the scratching of wafer backs during the transportation of the wafers from the stepper to the cassette holders.
To achieve these and other advantages and in accordance with the invention, as embodied and broadly described herein, the invention provides a method for preventing the scratching of wafer backs by the fetch arm of a stepper when the wafers are loaded into cassette holders. The main characteristic of this method is that, before the wafer enters the cassette holder, the vacuum in the suction head is released. The release of vacuum reduces frictional force between the wafer back and the suction head due to a wafer shock when there is an accidental impact of the wafer with the side of the cassette holder. Thus, scratching of wafer backs by the suction head of a fetch arm is avoided.
In another aspect, the invention provides a method for preventing the scratching of wafer backs by a fetch arm of a stepper when the wafers are loaded into a cassette holder. The method comprises the steps of, (a) holding the wafer with the vacuum from a suction head on the fetch arm before the fetch arm starts moving toward the cassette holder, (b) releasing the vacuum that holds the wafer after the fetch arm has moved forward a prescribed period but before the wafer enters the cassette holder, and (c) stopping the fetch arm once the wafer has entered the cassette holder.
In another aspect, the invention provides a controlling system for preventing the scratching of wafer backs being inserted into a cassette holder and held by a vacuum to a suction head of a fetch arm. The controlling system comprises multiple sensors for determining the position of the fetch arm and outputting corresponding signals to a microcontroller connected to a vacuum release controller which provides a signal to a vacuum solenoid valve so that the vacuum in the suction head is released just prior to insertion of the wafer into the cassette holder.
According to one preferred embodiment of this invention, the vacuum release controller comprises a first signal delaying circuit for delaying a rising edge of an input signal from a first sensor for a first prescribed period before outputting a first delayed signal, which first sensor detects a first position of the fetch arm. The vacuum release controller also comprises a second signal delaying circuit for delaying a falling edge of an input signal from a second sensor for a second prescribed period before outputting a second delayed signal, which second sensor detects a second position of the fetch arm. In addition, the vacuum release controller includes a timing control circuit coupled to the first and second signal delaying circuits for receiving the first and second delayed signals to generate a second control signal. The vacuum release controller further includes an opto-isolated electronic switching circuit coupled to the timing control circuit and the vacuum solenoid valve, for receiving the second control signal and a first control signal generated by the microcontroller to control the vacuum solenoid valve, thereby controlling the sequence of vacuum releasing and vacuum holding actions in the suction head of a fetch arm. The second control signal releases the vacuum from the end of the first prescribed period when the fetch arm starts moving away from the first position until the end of the second prescribed period when the fetch arm arrives in the second position.
It is to be understood that both the foregoing general description and the following detailed description are exemplary, and are intended to provide further explanation of the invention as claimed.
BRIEF DESCRIPTION OF THE DRAWINGS
The accompanying drawings are included to provide a further understanding of the invention and are incorporated in and constitute a part of this specification. The drawings illustrate embodiments of the invention and, together with the description, serve to explain the principles of the invention. In the drawings:
FIG. 1 is a perspective view of wafer holders and part of the structural components of the transporting system of a conventional stepper;
FIG. 2 is a block diagram of a controlling circuit for controlling the movement of the fetch arm of a conventional stepper;
FIG. 3 is time diagram for the sequence of actions associated with the movement of fetch arm of a conventional stepper;
FIG. 4 is a time diagram for the sequence of actions associated with the movement of fetch arm of a stepper according to one preferred embodiment of this invention;
FIG. 5 is a block diagram showing a controlling circuit for controlling the movement of fetch arm of a stepper according to one preferred embodiment of this invention;
FIG. 6 is a circuit diagram of a vacuum release controller;
FIG. 7 is a circuit diagram showing an opto-isolated electronic switching circuit, an output interface, a vacuum solenoid valve and their cable connections.
DESCRIPTION OF THE PREFERRED EMBODIMENTS
Reference will now be made in detail to the preferred embodiments of the invention, examples of which are illustrated in the accompanying drawings. Wherever possible, the same reference numbers are used in the drawings and the description to refer to the same or like parts.
The present invention is directed to providing an improved method for minimizing scratches to the back of wafers during the process of transporting wafers from the stepper to the cassette holders using the fetch arm. Furthermore, a separate vacuum release controller is added for executing the improved method of this invention. During the process of returning a wafer to the cassette holder, the vacuum release controller releases the vacuum in the suction head after the fetch arm has moved forward from its initial position for a prescribed period. Through the vacuum releasing action, should the wafer accidentally hit the cassette holder and be shifted, the wafer back will not be scratched because there is no suction in the contacting area between the wafer and the suction head.
FIG. 4 is a time diagram for the sequence of actions associated with the movement of fetch arm of a stepper according to one preferred embodiment of this invention. The sequence of actions for the fetch arm and the sequence of vacuum states of the suction head is the same as in a conventional design, shown in FIG. 3, for the unloading of the wafer from the cassette holder and the performance of microlithographic projections. In accordance with the invention, the timing of the vacuum-hold and vacuum-release states of the suction head is controlled when the wafers are brought back from the stepper to the cassette holder. The following description explains in detail the controlling mechanism of this invention necessary for transporting the wafers back to the cassette holder.
As shown in FIG. 4, the period starting from time t1 and finishing at time t8 is the period when the activities involved in bringing the wafer 130 back to the cassette holder 100 are carried out. The period when the vacuum holding and vacuum releasing actions are executed is particularly important in accordance with the invention. Refer to FIGS. 1 and 4 for the following description of this period.
(1) At time t1, the fetch arm 110 remains stationery in position A1. A vacuum is formed in the suction head.
(2) At time t2, the fetch arm 110 starts moving from position A1 toward A2. The vacuum in the suction head is maintained.
(3) At time t3, the fetch arm 110 is still on its journey toward position A2, but the wafer 130 is about to enter the cassette holder 100. The vacuum in the suction head is released.
(4) At time t4, the fetch arm 110 has reached position A2 and stopped. The suction head remains at the vacuum-released state.
(5) At time t5, while the fetch arm 110 remains stationery in position A2, a vacuum is formed in the suction head for checking whether the wafer 130 is already inside the cassette holder 100.
(6) At time t6, while the fetch arm 110 remains stationery in position A2, the vacuum in the suction head is released.
(7) At time t7, the fetch arm 110 starts to retract from position A2 toward position A1. The suction head remains at the vacuum-released state. The cassette holder 100 moves up a little to receive the wafer 130.
(8) At time t8, the fetch arm 110 has returned to position A1, thereby completing the operational cycle of putting the wafer 130 back to the cassette holder 100.
The vacuum holding and vacuum releasing actions of this invention described above provides a method for preventing the scratching of wafer backs by the fetch arm of a stepper. The main characteristic of this method is that, before the wafer enters the cassette holder, the vacuum in the suction head is released. The release of vacuum serves to reduce frictional force between the wafer back and the suction head due to a wafer shock when there is an accidental impact of the wafer to the side of the cassette holder. Thus, scratching of wafer backs by the suction head of a fetch arm is prevented.
FIG. 5 is a block diagram showing a controlling circuit for controlling the movement of fetch arm of a stepper according to one preferred embodiment of this invention. Many of the devices used in the circuit as shown in FIG. 5 are the same as in FIG. 2. For example, the first sensor 200, the second sensor 210, the input interface 220, the microcontroller 230, the output interface 240 and the vacuum solenoid valve 250 are functionally the same as in FIG. 2, and therefore requires no further explanations. The main difference lies in the addition of a vacuum release controller 500 as shown in FIG. 5. After receiving the first sensor signal S start and the second sensor signal S stop , the signals are processed in parallel along with the other conventional controlling devices. The vacuum release controller then generates a controlling signal for forcing the release of vacuum in the suction head. Subsequently, this controlling signal together with the conventional first control signal S c control the opening and the closing of the vacuum solenoid valve 250. Hence, the sequence of actions for releasing or holding a vacuum in the suction head is prescribed.
FIG. 6 is a circuit diagram of a vacuum release controller 500. The vacuum release controller 500 includes a first signal delaying circuit 510, a second signal delaying circuit 520, a timing control circuit 530 and an opto-isolated electronic switching circuit 540.
The first signal delaying circuit 510 delays the rising edge of the first sensor signal S start from the first sensor 200 for a first prescribed period which is the arithmetic difference between time t3 and t2 as shown in FIG. 4. Therefore, properly delayed signal can be output to match the varying speeds of different fetch arms, and thus ensuring the release of vacuum before the wafer enters the cassette holder.
The second signal delaying circuit 520 delays the falling edge of the second sensor signal S stop from the second sensor 210 for a second prescribed period which is the arithmatic difference between time t5 and t4 as shown in FIG. 4. Therefore, a vacuum release stage will not cease before the fetch arm has stopped at time t4.
The timing control circuit 530 is preferably a D-type flip-flop U2B. The D-type flip-flop uses the output signal S start .sbsb.-- delay , as shown in FIG. 4, generated by the first signal delaying circuit 510 as an input clock signal, and uses the output signal S stop .sbsb.-- delay from the second signal delaying circuit 520 as an input clear signal. As shown in FIG. 6, the complementary output terminal Q of the flip-flop is coupled to the input terminal D. Therefore, the timing control circuit 530 works by receiving the output signal S start .sbsb.-- delay from the first signal delaying circuit 510 and the output signal S stop .sbsb.-- delay from the second signal delaying circuit 520 and generating a second control signal S Q (shown in FIG. 4) for controlling the starting and the length of the vacuum-release stage.
The opto-isolated electronic switching circuit 540 is a contactless switch connected to the output interface 240 and the vacuum solenoid valve 250 of a conventional fetch arm controlling system. FIG. 7 is a circuit diagram showing an opto-isolated electronic switching circuit 540, an output interface 240, a vacuum solenoid valve 250 and their coupling relationship. As shown in FIG. 4, the opto-isolated electronic switching circuit 540 receives the first control signal S c and the second control signal S Q , then generates an output signal S P3 .sbsb.-- 2 for controlling the opening and closing of the vacuum solenoid valve 250, thereby controlling the vacuum-hold and vacuum-release states of the suction head.
It is clear from the above description of the circuit operation that the first control signal S c is combined with the second control signal S Q to determine the vacuum states of the suction head. Using FIG. 4 as a reference, timing control is described in detail below.
(1) Between time t1 to t3, the first control signal S c is at logic high and the second control signal S Q is also at logic high. Therefore, signal S P3 .sbsb.-- 2 is at logic low and the suction head is in a vacuum-hold state.
(2) Between time t3 to time t5, the first control signal S c is at logic high and the second control signal S Q is at logic low. Therefore, signal S P3 .sbsb.-- 2 is at logic high and the suction head is in a vacuum-release state.
(3) Between time t5 to time t6, the first control signal S c is at logic high and the second control signal S Q is at logic high again. Therefore, signal S p3 .sbsb.-- 2 is at logic low and the suction head returns to a vacuum-hold state.
(4) Between time t6 to time t8, the first control signal S c is at logic low and the second control signal S Q is at logic high. Therefore, signal S P3 .sbsb.-- 2 is at logic high and the suction head returns to a vacuum-release state.
Thus, the actions that are provided by the first control signal S c in the present invention are similar to the actions that are provided by the control signal of a conventional controlling system. The main difference is the addition of a second control signal S Q which carries out the order for releasing the vacuum in the suction head when S Q is at logic low. Therefore, the design of releasing the vacuum in the suction head before the wafer enters the cassette holder is achieved.
The above description of the preferred embodiments shows that, by adding a vacuum release controller, the design of releasing the vacuum in the suction head before the wafer enters the cassette holder can be achieved. Therefore, in the process of returning a wafer to the cassette holder, should the wafer accidentally hit the cassette holder and get a shock, frictional force in the contacting area between the wafer and the suction head will be minimized, and scratches will not be made. Hence, the present invention not only is favorable to subsequent wafer processing operations, but also can improve production.
It will be apparent to those skilled in the art that various modifications and variations can be made to the structure of the present invention without departing from the scope or spirit of the invention. In view of the foregoing, it is intended that the present invention cover modifications and variations of this invention provided they fall within the scope of the following claims and their equivalents.
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A method for avoiding scratching of wafer backs being held by a vacuum to a fetch arm of a stepper machine for insertion into a cassette holder includes releasing the vacuum in the suction head of the fetch are before the wafer enters the cassette holder. The release of vacuum reduces frictional force between the wafer back and the suction head when the wafer accidentally hits the side of the cassette holder. Therefore, the vacuum release method avoids scratching of wafer backs by the suction head of the fetch arm. The invention requires a separate vacuum release controller to release the vacuum in the suction head for a prescribed delaying period after the fetch arm starts moving toward the cassette holder.
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FIELD OF THE INVENTION
This invention relates town alignment device. In particular, the invention relates to an alignment device for starter bars for masonry block walls.
BACKGROUND TO THE INVENTION
The use of masonry block walls in construction is very popular. In order to construct a masonry block wall that has the necessary structural strength, the masonry block wall must be tied to an associated foundation or footing. When the foundation or footing for a masonry block wall is being prepared, reinforcing bars are placed in the footing. These reinforcement bars (known as starter bars) protrude from the concrete footing and are required to engage the masonry block wall. However, the starter bars are often not placed in the correct location in relation to the cavity in the masonry blocks of the masonry block wall.
Misaligned starter bars are a huge problem for a block layer. The block layer is often unable to bend or adjust the incorrectly placed starter bars coming out from the concrete footing. Accordingly, the starter bars are not in their correct position and do not line up with the vertical reinforcing bars that are placed in the masonry block wall. The starter bars being out of position and not aligning with the vertical reinforcing bars in the masonry block wall during wall construction will result in the wall not meeting the structural capacity as detailed in the engineering specification for the wall. In a worst case scenario, the entire wall, including the footing, will need to be demolished and rebuilt at substantial cost.
The majority of reinforced masonry block walls require starter bars (and vertical reinforcing bars) to be generally used at 400 mm intervals along the wall. The problem of misaligned starter bars is therefore a considerable inconvenience to the block layer because of the large number of starter bars in each wall construction.
OBJECT OF THE INVENTION
It is an object of the invention to overcome or at least alleviate one or more of the above disadvantages and/or provide the consumer with a useful or commercial choice.
SUMMARY OF THE INVENTION
In one form, although not necessarily the only or broadest form, the invention resides in an alignment device able to align substantially vertical starter bars for a masonry block wall, the alignment device comprising:
a plurality of spacer arms spaced a predetermined distance from each other; and
a plurality of attachment members attached to respective spacer arms, the attachment members able to be operatively attached to the vertical starter bars.
Preferably there are at least three or more spacer arms. The spacer arms are normally equally spaced from each other.
The spacer arms may be interconnected by at least one connector rail. Typically, there are two connector rails.
The spacer arms may be removably attached to the at least one connector rail. Alternatively, the spacer arms may be integrally formed with the connector rail.
Typically, the spacer arms are relatively linear. However, it should be appreciated that the spacer arms may be non-linear.
Similarly, the at least one connector rail is relatively linear. However, it should be appreciated that the at least one connector rail could be non-linear.
The attachment members are preferably in the form of a clip. However, other forms of attachment members may be suitable, such as clasp, buckle, catch, clamp, clench, clinch, fastening, grapple, hook, pin or a snap.
The attachment members may be removably attached or fixed to respective spacer arms.
One or more supports may form part of the alignment device to ensure that the spacer arms are held at a desired position. Typically, there are a plurality of supports. More preferable there are at least three supports. The supports may be connected or tied to a spacer arm and/or a connector rail.
Each support may include a holder and at least one leg. The holder may operatively support the spacer arms. The holder may engage and/or position and/or align a spacer arm and/or a connecting rail. The holder may include holder members to engage and/or align a spacer arm or a connecting rail.
The leg may be removably attached to the holder. The leg may be movable and/or adjustable with respect to the holder. However, it should be appreciated that the leg and holder may be fixed with respect to each other. Accordingly, the leg and holder may be integrally formed.
In another form, the invention resides in a method of aligning substantially vertical starter bars for a masonry block wall; the method including the steps of:
locating a plurality of starter bars at a desired position, each starter bar having at least one attachment member; and
attaching the vertical starter bars to at least some of the attachment members to align the vertical starter bars.
The method may further include one or more of the steps of:
connecting the starter bars to a at least one connection rail;
operatively supporting the starter bars with a support.
BRIEF DESCRIPTION OF THE DRAWINGS
An embodiment, by way of example only, will be described with reference to the accompanying drawings, wherein:
FIG. 1 is a perspective view of an alignment device being used to support a series of starter bars according to an embodiment of the invention;
FIG. 2 is a side sectional view of an alignment device according to an embodiment of the invention;
FIG. 3 is a perspective view of an alignment device as shown in FIG. 1 according to an embodiment of the invention; and
FIG. 4 is a perspective view of an alignment device incorporating a different spacer arm.
DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENT
FIGS. 1 and 2 show an alignment device 10 that is used to hold a series of starter bars 5 in a desired position in order to ensure the starter bars 5 are positioned correctly within a proposed masonry wall. The alignment device 10 includes a series of spacer arms 20 , an associated series of attachment members 30 , two connection rails 40 and a number of supports 50 .
The spacer arms 20 are used to space starter bars 5 at the correct distance from each other. The spacer arms 20 , shown in more detail in FIG. 3 , are made from injection moulded plastic. However, it should be appreciated that the spacer arms 20 may be made using other suitable materials. The spacer arms 20 are elongate and rectangular in transverse cross section. However, it should be appreciated that the spacer arms 20 may be of a variety of other transverse cross sections including round, elliptical, square or the like shape. A snap-in clasp 21 is located at each of the ends of each of the spacer arms 20 to connect the spacer arms 20 to respective connection rails 40 . The spacer arms 20 may be made of various lengths to suit masonry walls of different sizes.
The attachment members 30 are used to hold respective starter bars 5 . The attachment members 30 are removably attached to the spacer arms 20 . A person skilled in the art would appreciate that various known forms of removable attachment of the attachment members to the spacer arms may be used. For example, the attachment members may be threaded with a corresponding threaded hole provided in the spacer arm. Alternatively, the attachment members may be snap locked into corresponding holes provided in the spacer arm 20 . This enables attachment members 30 of different sizes to be attached to the spacer arms 20 as shown in FIG. 3 and FIG. 4 . However, it should be appreciated that the attachment members 30 may be integrally formed with the spacer arms 20 .
The position of the attachment members 30 may be varied according with structural requirements of a masonry wall. For example, the attachment members 30 shown in FIG. 3 are located centrally on the spacer arms 20 whilst the attachment members 30 , shown in FIG. 4 , is located toward one end of the spacer arm 20 . It should be appreciated that the number of attachment members 30 and the position of the attachment members 30 may be varied on the spacer arms 20 depending on requirements. For example, a spacer arm 20 may have two attachment members 30 , one attachment member 30 having a position as shown in FIG. 3 and one attachment member 30 as shown in FIG. 4 .
The attachment members 30 , shown in FIGS. 3 and 4 , are in the form of C-shaped clips. The clips are resilient so that a starter bar 5 can be held by the clip. The C-shaped clips may be of different sizes to cater for different sized starter bars 5 . It should be appreciated that other forms of attachment members 30 may be used instead of the C-shaped clips to hold the starter bars 5 .
The connection rails 40 are used to hold the spacer arms 20 . The connection rails 40 are in the form of a C-section 41 . Holes 42 are located through and spaced equally along the length of the C-section 41 . The holes 42 are used for location of respective snap-in clasps 21 of the spacer arms 20 . As an alternative, it should be appreciated that the spacer arms 20 and the connection rails 40 may be permanently fastened to each other. Both the connection rails 40 are of a continuous length. However, it should be appreciated that the connection rails 40 may be formed from sections which are fitted together to form the connection rail 40 . A person skilled in the art would readily appreciate how sections are connected together. Further, it should be appreciated that the connection rails may be shaped differently.
The supports 50 , shown in detail in FIG. 2 , are used to support the connection rails 40 and accordingly the spacer arms 20 . Each support 50 is formed from a holder 60 and a leg 70 . The holder 60 includes two holding members 61 which engage and support the connection rails 40 . The holder members 61 are adjustable to align the spacer arms 20 and connection rails 40 above a trench to represent the location of the wall to be built. It should be appreciated that the holder 60 may be modified to engage and support the spacer arms 20 .
The leg 70 is located at one end of the holder 60 and has a pointed end 71 for digging into the ground. The leg 70 is movable with respect to the holder 60 .
In order to correctly align a series of starter bars 5 , the first step is to locate each pointed end 71 of the leg 70 of the supports 50 within the ground and away from and adjacent to (but not within) a trench for forming a concrete footing. The holders 60 of the supports 50 are then moved with respect to the leg 70 to locate the holders 60 at a desired height and desired horizontal location representing the exact position of the block wall to be built. Next, the attachment members 30 are selected depending on the diameter of the starter bars 5 . The spacer arms 20 are also selected depending on requirements of the masonry wall such as positioning requirements of the starter bar 5 and the size of the blocks.
The attachment members 30 and the spacer arms 20 are joined together (if required). Subsequently, the spacer arms 20 are inserted into the holes of the connection rails 40 to form a “ladder” arrangement. The spacer arms 20 are held to the connection rails 40 using the snap-in clasps 21 .
Once the starter arms 20 and connection rails 40 are joined together, the connection rails 40 are placed within holders 60 of the supports 50 . The starter bars 5 are then attached to the attachment members 30 to hold the starter bars 5 in their desired location. When the starter bars 5 are set plumb, a base of the starter bar 5 can be tied off to a reinforcing cage in the footing. Accordingly, the footing can then be laid ensuring the starter bars 5 are in the correct location with respect to the masonry wall to be built.
There are considerable advantages in using the alignment device 10 to install the starter bars 5 in a precise location when forming the footing, when pouring the concrete for the footing and when building the masonry block wall on the top of the footing. The advantages include:
1. Reducing the time taken to set out and accurately tie the starter bars 5 to the reinforcing cage in the footing trench and maintaining the starter bars 5 in vertical alignment.
2. Allowing one person to easily tie the starter bars 5 in the correct location in the footing trench and thereby ensuring the starter bars 5 will be in the correct location in the masonry blocks when the blocks are laid.
3. Providing the correct location for the starter bars 5 for both centrally located and non-centrally located reinforcing steel applications, being typical specifications for reinforced masonry block walls.
4. Ensuring the starter bars 5 are rigidly and securely positioned by the combination of tying the starter bar 5 to the reinforcing cage in the trench and clipping the starter bar 5 to the alignment device 10 at about 500 mm above ground level. This two point connection provides the additional security that ensures the starter bar 5 does not move out of place even during the pouring of the concrete for the footing.
5. Providing a simple and effective means of setting and maintaining the starter bars 5 in a vertical position to ensure they line up adjacent to the vertically placed reinforcing steel in the masonry block wall.
6. Providing the longitudinal set out of the starter bars 5 at 400 mm centres for the length of the wall or at the centres specified in the engineering specification.
7. Assisting in the containment of the entire reinforcing steel grid of the foundation.
In this specification, the terms “comprise”, “comprises”, comprising” or similar terms are intended to mean a non-exclusive inclusion, such that a system, method or apparatus that comprises a list of elements does not include those elements solely, but may well include other elements not listed.
It should be appreciated that various other changes and modifications may be made to the invention described without departing from the spirit or scope of the invention. For example, the alignment device could be manufactured in one piece flat lengths of extruded plastic with the connection rails and spacers arms being integrally formed. The lengths have sufficient strength to adequately support the starter bars above ground level while being flexible enough to be rolled up for convenience between jobs. Accordingly, the starter bars in this instance will be tied to spacer arms using wire as the attachment members.
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The invention resides in an alignment device able to align substantially vertical starter bars for a masonry block wall, the alignment device comprising a plurality of spacer arms spaced a predetermined distance from each other and a plurality of attachment members attached to respective spacer arms, the attachment members able to be operatively attached to the vertical starter bars.
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BACKGROUND OF THE INVENTION
1. Field of the Invention
The present invention relates to a stand for supporting pizza pies at different verticaly spaced horizontal levels along a vertical rod and, more particularly, to a pizza stand where the supporting means are discs which can be removably attached at these vertically spaced levels along the rod.
2. Description of the Prior Art
The prior art discloses stands or devices for supporting objects at vertically spaced horizontal levels such as shown in Grennan Patent No. 1,703,340; however, the prior art does not disclose or suggest a spring type clip means whereby a plurality of discs may be removably mounted on a vertical rod at spaced horizontal levels for holding objects, such as pizzas, thereon.
SUMMARY OF THE INVENTION
The present invention involves a stand for supporting a plurality of objects, such as pizzas, at a plurality of vertically spaced levels. The stand includes a vertical rod which is rounded at its upper end and which connects with a cylindrical housing adjacent its lower end. A plurality of legs extend nearly horizontally outwardly but somewhat downwardly inclined from the cylindrical housing for supporting the rod in a vertical position. A plurality of discs are adapted to be supported along the rod at vertically spaced intervals. The lowermost disc is preferably disposed between the lower end of the rod and the cylindrical housing. The remaining discs are each provided with a central opening of the same size and shape as the cross-section of the rod. Each disc is also provided with a collar attached to the disc below the central hole thereof. Each collar is provided with a circular bore equal in size and disposed in alignment with the hole in each disc. The rod is further provided with a plurality of circumferential grooves of the same vertical width. Each collar is provided with a pair of opposite radial slots whose width is substantially equal to the width of the grooves on the rod. A plurality of clips are provided for connecting the collars to the rod. Each clip is made of a continuous piece of stainless steel spring wire which is bent intermediate its ends to form a loop which connects with a first pair of arms extending divergently away from the loop and which, when a given collar is disposed on the rod with its slots in alignment with a given circumferential groove, this first pair of arms is adapted to be received in the slots on the given collar and simultaneously in the given circumferential groove. The clip is further provided with a second pair of arms which connect with the first pair of arms at a location on the opposite side of the collar from the loop of the clip and which extends convergently away from the loop so as to form with the first pair of arms and with the loop a substantially horizontal plane. The second pair of arms of the clip connect with a third pair of arms which are disposed in parallel relation with each other and at right angles to the horizontal plane described above. The third pair of arms connect with a fourth pair of arms which are attached to the third pair of arms at right angles thereto and which extend in substantially parallel relation with the second pair of arms. Thus, the fourth pair of arms extend divergently away from each other towards the loop of the clip but spaced from the horizontal plane described above. This fourth pair of arms also contacts the outer periphery of the collar. Thus, when thumb pressure is applied to the third pair of arms in a direction towards the collar, the relative wedging action which occurs between the collar and the fourth pair of arms is such as to cause the clip to spread open whereby the first pair of arms are opened up and moved in a rearward direction (the direction of the force) so as to bring the first pair of arms out of the area of the circumferential groove, although the first pair of arms will still be received in the slots on the collar. At this time, the disc and its associated collar can be moved upwardly or downwardly with respect to the rod; alternatively, the given disc and associated collar can be removed completely from the rod by maintaining thumb pressure on the associated clip.
BRIEF DESCRIPTION OF THE DRAWINGS
FIG. 1 is a plan view of the pizza holder of the present invention showing a portion of one of the supporting legs broken away;
FIG. 2 is a vertical sectional view taken along section line 2--2 of FIG. 1;
FIG. 3 is a fragmentary front elevation showing only a portion of the vertical rod and a portion of the horizontal disc but showing the relationship between the clip, the collar and the rod;
FIG. 4 is a left-hand side view taken from FIG. 3; and
FIG. 5 is a sectional view taken along section line 5--5 of FIG. 3.
DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS
Referring to the drawings in detail, FIGS. 1 and 2 show a substantially vertical rod 10 having an upper rounded end 12 and a lower threaded end 14 of reduced size. The lower threaded end 14 is adapted to be received in a threaded hole in a short cylindrical housing 16. Three legs 18, 20 and 22 extend radially outwardly from the cylindrical housing 16. The inner end of each leg, for example, the end 24 of the leg 20 is threaded and is adapted to be received in a threaded hole 26 in the cylindrical housing 16. The legs 18, 20 and 22 are preferably slightly downwardly inclined as shown in FIG. 2 so that, when the outer ends of these legs rest on the top of a table, for example, the lower end of the cylindrical housing 16 will be slightly spaced above the surface of the table.
A flat horizontal plate 28 in a form of a disc is received between the lower end of the rod 10 and the cylindrical housing 16. This disc 28 has a central hole 30 through which the lower threaded end 14 of the rod 10 is adapted to pass. This disc 28 constitutes the lowermost level upon which objects, such as pizzas, may be supported.
A plurality of discs 32 are adapted to be removably secured to the rod 10. As shown in FIG. 2, there are three such discs 32; however, it could be understood that a greater or lesser number of discs 32 could be employed. Whereas, the lowermost disc 28 is shown in a non-slidable or non-removable relationship, it should be understood that the lowermost disc 28 could be eliminated and replaced with a disc 32 and its method of attachment (as will be explained hereinafter) so that all discs mounted on the rod could be removable.
Each disc 32 is provided with a central opening or hole 34 of substantially the same size and shape as the cross-section of the rod 10 so that each disc can be received on the rod 10 and can be slid upwardly or downwardly with respect to the rod. A cylindrical collar 36 is attached to each disc 32 below the opening 34. Each collar 36 has a central bore 38 therethrough which is of the same size and in alignment with the hole 34 in the disc 32.
The rod 10 is provided with a plurality of circumferential grooves 40 which extend all the way around the rod and which are of substantially equal vertical width. Each collar 36 is provided with a pair of opposite radially directed slots 42 and 44 which extend from the outside of each collar and into the bore 38 thereof. As best shown in FIG. 2, when the discs 32 are properly positioned along the rod 10 the radial slots 42 and 44 are in alignment with the circumferential groove 40.
A plurality of clips 46 are employed to secure each collar 36 in position on the rod 10 when the slots 42 and 44 are in alignment with a circumferential groove 40.
As best shown in FIGS. 3, 4 and 5, the clip 46, which is preferably made of a single piece of stainless steel spring wire, is bent intermediate its ends to form a substantially semi-circular loop 48. The ends of the loop 48 merge with a pair of arms 50 and 52 which extend divergently outwardly with respect to each other in a direction away from the loop, as best shown in FIG. 5. These arms 50 and 52 are adapted to be received in the slots 42 and 44 of the collar 36 and also simultaneously in the annular or circumferential groove 40 in the rod when the collar 36 is positioned such that its slots are in alignment with the circumferential groove. When the arms 50 and 52 are received in the slots and in the groove on the rod, the associated collar is locked in position so that it will neither slide upwardly nor downwardly along the rod 10. The arms 50 and 52 extend in their divergent direction to a location spaced beyond the periphery of the collar 36 as best shown in FIG. 5 at which location a second pair of arms 54 and 56 connect with the ends of the first pair of arms. The second pair of arms 54 and 56 extend convergently towards each other in a direction away from the loop 48. At this juncture it should be noted that the loop 48, the arms 50 and 52, and the second pair of arms 54 and 56 form a substantially horizontal plane. The outer ends of the arms 54 and 56, in turn, connect with the lower ends of a pair of vertical arms 58 and 60 (as best shown in FIG. 4) which extend at right angles to the horizontal plane defined by the loop and the first two pairs of arms. The upper ends of the third pair of arms 58 and 60 connect with a fourth pair of arms 62 and 64 which extend divergently away from each other in a direction towards the loop 48. As will appear from a consideration of FIG. 5, the fourth pair of arms 62 and 64 are parallel with the second pair of arms 54 and 56. The outer free ends 66 and 68 of the arms 62 and 64, respectively, constitute the ends of the piece of spring wire which is bent to form the clip itself. Incidentally, it should be understood that the thickness of the steel wire, which forms the clip 46, is substantially equal to the vertical width of the slots 42 and 44 as well as the vertical width of the circumferential groove 40 on the rod 10.
As best shown in FIGS. 3 and 5, the ends of the fourth pair of arms 62 and 64 engage the outer periphery of the collar 36. It will also appear that the third pair of arms 58 and 60 (see also FIG. 4) are relatively closely adjacent each other. Therefore, if one were to push on the arms 58 and 60 (for example, with simple thumb pressure) towards the collar 36, the relative wedging action, which exists between the collar 36 and the arms 62 and 64 will cause the clip to spread open whereby the first pair of arms 50 and 52 are spread apart relatively to a position where they are no longer received in the peripheral groove 40, even though these arms 50 and 52 will still be in the radial slots 42 and 44; at this time, it is possible to move the collar 36 upwardly or downwardly with respect to the groove 40 against which this collar was previously locked. In fact, by maintaining thumb pressure on the arms 58 and 60 the collar 36 and its associated disc can be moved entirely from the rod 10.
As indicated previously, the lowermost disc 32 is preferably relatively permanently associated with the rod 10 as shown in FIG. 2, although this relatively fixed disc 28 could be replaced by a movable disc 32 by adding a circumferential groove 40 (not shown) adjacent the bottom of the rod 10 and including and additional disc 32 and its associated collar 36, as described above. At any event, it will be assumed that there are no discs 32 on the rod 10 and that the lowermost disc 28 alone is disposed on the rod 10. At this point in time a pizza can be disposed over the rod 10 and lowered onto the lowermost disc 28. For this purpose, the circular pizza pans (not shown) would be provided with a central hole (not shown) of the same size as the shaft 10, and since the pizza itself will have been cut into pie-shaped sections, there will be no problem in lowering the pan and pizza onto the lowermost disc 26. Now, a disc 32 and its associated collar are disposed over the end of the rod 10 and, by manipulating a proper thumb pressure on the associated clip 46, this disc 32 is lowered into the position immediately above the lowermost disc 28 and, at this time, an additional pizza in its pan can be lowered into the position onto this disc 32. This process is repeated by adding one disc at a time, disposing a pizza and pizza pan over the disc and then adding the next disc until the rod 10 is provided with the maximum number of discs it is capable of holding.
Whereas, the present invention has been described in particular relationship to the drawings attached hereto, it should be understood that other and further modifications, apart from those shown or suggested herein, may be made within the spirit and scope of this invention.
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A stand for supporting a plurality of objects at a plurality of different vertical levels comprising a vertical rod having a plurality of spaced circumferential grooves, a plurality of cylindrical collars each having a central bore therethrough of substantially the same size as the cross-section of the rod, each collar having a pair of opposite radial slots extending from the outside of the collar, a horizontal plate connected to each collar and extending radially outwardly from the collar for supporting objects thereon, and a plurality of clips for connecting the collars to the rod, wherein each clip is made of a continuous piece of wire bent intermediate its ends to form a substantially semi-circular loop with arms to engage the collar and the grooves.
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BACKGROUND OF THE INVENTION
This invention relates to stringed musical instruments, and deals more particularly with a mute mechanism intended to be permanently attached to such an instrument and readily manually shiftable between active and inactive conditions.
The mechanism of this invention includes a mute having a face, preferably provided by a pad or body of resilient material, pressed against the strings of the instrument when the mute is in its active condition. Such a mute is particularly well adapted for use with electric string basses and it is therefore herein shown and described in such environment. There is, however, no intention to limit the mechanism of this invention to such use, and instead it may be applied to a wide variety of other types of stringed instruments if desired.
SUMMARY OF THE INVENTION
The invention resides in a mute mechanism having a mute with a face adapted to engage the strings of the instrument when in an active position. The mute is supported for rectilinear movement along an axis perpendicular to its string engagement face to move it into and out of contact with the strings. A manually operable actuating member, shiftable between two positions, and a mechanical linkage or other motion transmitting means between the actuating member and the mute move the mute between its string contacting active position and its string non-contacting inactive position in response to movement of said actuating member between its two positions.
The invention further resides in the mute being carried by a base attached, or adapted for attachment to, an instrument body, in the actuating member being a slide slidably carried by the base, in a pair of links each pivotally connected at one end to the slide and pivotally connected at its other end to the mute for moving the mute relative to the base in response to movement of the slide relative to the base, and in the base having a recess for receiving the mute which recess has a cross-sectional shape complementary to that of the mute so that the walls of the recess restrain the mute to rectilinear sliding movement relative to the base.
BRIEF DESCRIPTION OF THE DRAWING
FIG. 1 is a fragmentary plan view of an electric string bass equipped with a mute mechanism embodying this invention.
FIG. 2 is an end elevational view of the mute mechanism of FIG. 1 and taken on the line 2--2 of that figure, this figure showing the mute in its lowered or inactive position at which it is free of the strings.
FIG. 3 is a view similar to FIG. 2 but shows the mute in its raised or active position at which it contacts the strings.
FIG. 4 is a fragmentary sectional view taken on the line 4--4 of FIG. 3.
FIG. 5 is a sectional view taken on the line 5--5 of FIG. 4.
FIG. 6 is a view similar to FIG. 5 but shows the mute in its lowered or inactive position.
DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENT
Referring to the drawing, a mute mechanism 10 embodying the present invention is shown in FIG. 1 in combination with an electric string bass 12. This instrument has a solid wooden body 14 and a neck 16, with attached fret board 18, extending from one end thereof and terminating in a peg head 20. Each of four strings 24, 24 is anchored at one end to a tailpiece means indicated generally at 26 and at its other end to an associated one of four machine heads 28, 28 carried by the peg head 20. In passing from the tailpiece to the machine heads, the strings pass over and are stretched between a bridge near the tailpiece and a nut 30 adjacent the peg head 20. The bridge consists of four separate saddle members 32, 32 adjustably fixed to a base 34, preferably of die cast metal, in turn fixed to the instrument body 14. Each saddle member 32 supports an individual string 24.
In the illustrated case, the three components consisting of the tailpiece 26, the bridge and the mute mechanism 10 are combined with one another to form a single unit, and the base 34 is a part common to all three of these components. This, however, is not necessary to the invention and, if desired, the mute mechanism may be made separate from either or both of the tailpiece and bridge. In particular, in the description which follows, the base 34 provides the base of the mute mechanism but the mute mechanism may alternatively have a base separate from that of the bridge and tailpiece in other situations.
Turning now to FIGS. 2 to 6, the mute mechanism 10 includes a mute 36 comprised of a carrier 38 carrying a pad 40 of resilient material such as sponge rubber. A string engagement face 42 of the pad 40 faces and extends transversely across the four strings 24, 24. The mute 36 is received in a recess 44 of the base 34. This recess has a mouth facing the strings 24, 24 and the cross-sectional shapes of the recess and of the mute, in a plane generally parallel to the common surface defined by the strings, are complementary so that the mute is restrained by the walls of the recess to rectilinear movement toward and away from the strings, that is, to movement along an axis perpendicular to the string engagement face 42.
The mute 36 is movable relative to the base 34 between an inactive position, such as shown in FIG. 2, at which it is out of contact with the strings and an active position, such as shown in FIG. 3, at which it is held in engagement with the strings with the pad 40 being compressed between the strings and the carrier 38.
An actuating means for manually moving the mute between its active and inactive positions includes a manually shiftable actuating member in the form of a slide 46 having a handle portion 47 located on one side of the set of strings 24,24. A slide cavity 48 formed in the base 34, and communicating with the mute receiving recess 44, slidably receives the slide. The walls of the slide cavity 48 confine the slide 46 to rectilinear sliding movement relative to the base along the axis 50 shown in FIG. 6 between the two positions shown in FIGS. 5 and 6. Part of the slide cavity 48 is defined by a removable plate 52 held to the base 34, as by screws, as shown in FIG. 4. The base 34 and slide 46 have coengageable stop surfaces 54 and 56, FIG. 6, which are engageable as shown in FIG. 5 to limit leftward (as seen in the drawing) movement of the slide relative to the base.
The mute 36 is moved between its active and inactive positions in response to movement of the slide 46 between its two end positions by two links 58, 58 each pivotally connected to the slide 46 at one of its ends by a pivot pin 60 and pivotally connected at the other of its ends to the carrier part of the mute by a pivot pin 62.
It should further be noted from FIGS. 5 and 6 that the relative arrangement of the slide 46, mute 36, and links 58, 58 is such that as the slide is moved to the left to move the mute from its inactive (FIG. 6) position to its active (FIG. 5) position, the pivot pins 62, 62 move over center relative to the pivot pins 60, 60 just shortly prior to the FIG. 5 position being reached. Therefore, the pressure of the strings bearing down on the mute pad 40 will tend to hold the mute and slide in their FIG. 5 positions, that is with the stop surfaces 54 and 56 in engagement with one another, until the slide is manually shifted to the right to lower the mute.
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A mute mechanism for an electric string bass or other stringed musical instrument is permanently mounted on the body of the instrument and includes a rubber faced mute movable into and out of engagement with the instrument's strings by a manually shiftable slide readily accessible by a performer playing the instrument.
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CROSS REFERENCE TO RELATED APPLICATION
[0001] This application claims priority from German Patent Application Nos. 102 42 391.1 and 103 29 837.1, which are incorporated herein by reference.
BACKGROUND OF THE INVENTION
[0002] The invention relates to an apparatus at a draw frame or other textile machine having a drawing mechanism for the doubling and drafting of fibre slivers.
[0003] Certain known forms of draw frame have a drawing mechanism frame for accommodating the drawing mechanism, which has at least two pairs of rollers each comprising an upper roller and a lower roller, and means for adjusting the spacing of at least one of the lower rollers in relation to another lower roller, in each case having a mounting device for accommodating the lower roller, and lower rollers are arranged to be driven by at least one drive element endlessly revolving around pulley wheels.
[0004] In a known apparatus (DE-OS 20 44 996), the mountings of the intake and middle lower rollers are displaceable on the frame of the machine so that the extent of the drawing zone can be matched to the particular fibre staple. A tensioning pulley wheel, which is displaceable in a guideway in the frame of the machine, allows the length of the toothed belt to be modified in accordance with the changed spacing between the axes of the middle roller and a guide pulley wheel, brought about by displacement of the intake roller. The middle roller is driven by a further toothed belt. The latter toothed belt is tensioned by a tensioning pulley wheel which is fastened to the machine frame and which can pivot about one axis; as a result, it can also be matched to changed spacings between the axes of the intake roller and middle roller. It is disadvantageous that displacing devices for displacement of the intake roller and the middle roller and additional tensioning devices for re-tensioning of the toothed belts after the displacement operations are necessary, requiring a considerable outlay in terms of construction. In addition, it is disadvantageous that a number of work steps are required for the displacement operations and the subsequent re-tensioning operations. The belt tension is destroyed by the displacement process. Where the displacement is carried out manually, spacers are inserted between the mountings, the mountings being pushed against the spacers so that, in this case too, the amount of set-up work is considerable. Finally, the displacement and re-tensioning operations result in a doubling of potential error sources when setting the spacings and belt tensions.
[0005] It is an aim of the invention to provide an apparatus of the kind described at the beginning that avoids or mitigates the disadvantages mentioned and that especially is of simple construction and allows a considerable reduction in the work and time required for adjustment of the lower roller(s) and, accordingly, of the extent(s) of the drawing zone(s).
SUMMARY OF THE INVENTION
[0006] The invention provides a drawing mechanism having a drawing mechanism frame, at least two pairs of rollers each comprising an upper roller and a lower roller and having a mounting device for accommodating the lower roller, means for adjusting the spacing of at least one of the lower rollers in relation to another lower roller, and at least one drive device comprising a drive element endlessly revolving around pulley wheels, wherein the drive device can be used for adjusting the position of said at least one lower roller.
[0007] The measures according to the invention make it possible, by simple means, for the mountings and, as a result, the extents of the drawing zones (nip line spacings) to be adjusted in a short time. For the purpose of adjusting the extents of the drawing zones, elegant use is made of existing structural elements necessarily present in the draw frame, for example, a pulley wheel and the drive belt. Separate apparatuses for adjustment are not required. As a result of the fact that the drive belt can be in tension before, during and after adjustment, further apparatuses for re-tensioning the drive belt after the adjustment are not required, which allows the extents of the drawing zones of the drawing mechanism to be changed in a short time by means that are especially simple in terms of construction.
[0008] Advantageously, a said mounting device of a said lower roller is adjustable by means of a moving force applied to a pulley wheel of said drive device, which moving force is converted into an adjusting movement for the mounting device. As well or instead, a said mounting device of a said lower roller is advantageously adjustable by means of a moving force applied to a drive element of said drive device, which moving force is converted into an adjusting movement for the mounting device. Advantageously, the drive element is stationary and the pulley wheel is rotated. Advantageously, the pulley wheel is stationary and the drive element is moved. Advantageously, the rotation of the pulley wheel or the movement of the drive element is converted into the adjusting movement of the slider. Advantageously, at least one guide pulley wheel is attached to each slider (mounting); and the roller-driving pulley wheel or guide pulley wheel(s) act, in each case one after the other, on both sides of the tensioned drive element. Advantageously, the rotation of the pulley wheel or the movement of the drive element is accomplished manually. Advantageously, the slider is linearly displaceable.
[0009] Advantageously, the drive element is a toothed belt. Advantageously, an endless flexible toothed belt is present. Advantageously, the pulley wheels comprise toothed belt wheels. Advantageously, the pulley wheels comprise guide pulley wheels. Advantageously, at least one driving pulley wheel is provided. Advantageously, driven pulley wheels are present. Advantageously, the drive element loops around the pulley wheels. Advantageously, the drive element and the pulley wheel are in engagement with one another. Advantageously, the pulley wheel for adjustment of a slider is the drive pulley wheel of a lower roller (roller-driving pulley wheel). Advantageously, the slider is displaceable during adjustment. Advantageously, the slider is arranged to be stopped. Advantageously, the stopping arrangement is releasable. Advantageously, a display device for the position of the slider is present.
[0010] Advantageously, a drive motor is used for rotation of the pulley wheel. Advantageously, a drive motor is used for movement of the drive element. Advantageously, the drive motor is used for the lower rollers. Advantageously, a separate drive motor is used. Advantageously, belt shortening or belt lengthening is arranged to be automatically evened out during adjustment. Advantageously, the evening-out of belt length is carried out at a slider by two guide pulley wheels.
[0011] Advantageously, the lower rollers are arranged to be adjusted singly and independently of one another. Preferably, a roller-driving pulley wheel and a guide pulley wheel are attached to the slider of the intake roller and a roller-driving pulley wheel and a guide pulley wheel are attached to the slider of the middle roller. Advantageously, the drive element runs around the pulley wheels at the slider of the intake roller and around the pulley wheels at the slider of the middle roller in a mirror-reflected arrangement. Advantageously, the drive element is in tension before, during and after the displacement. Advantageously, the drive motor is in communication with an electronic control and regulation device. Advantageously, a measuring element is connected to the control and regulation device. Advantageously, the measuring element is capable of registering fibre-related and/or machinery-related measurement variables. Advantageously, adjustment of the slider is carried out when the drawing mechanism is in operation. Advantageously, adjustment of the slider is carried out when the drawing mechanism is not in operation. Advantageously, adjustment of the slider is carried out during can-changing. Advantageously, the draw frame is self-adjusting. Advantageously, adjustment of the slider is carried out by inputting adjustment variables. Advantageously, the adjustment variables can be input manually. Advantageously, a memory for adjustment variables is connected to the control and regulation device. Advantageously, the slider for the intake roller and the slider for the middle roller are arranged to be connected by a rigid connecting element. Advantageously, the connecting element is releasably connected. The spacing of the pairs of rollers in relation to one another may be adjustable without fibre material. The spacing of the pairs of rollers in relation to one another may be adjustable with fibre material. Advantageously, the extent of the preliminary draft zone can be adjusted. Advantageously, the extent of the main draft zone can be adjusted. Advantageously, the extent of the preliminary draft zone and the extent of the main draft zone can be adjusted. Advantageously, each lower roller has its own associated drive motor. Advantageously, the intake and middle lower rollers are arranged to be driven by one drive motor. Advantageously, a brake, stopping arrangement or the like is associated with the stationary pulley wheel. The brake, stopping arrangement or the like may be mechanical, electrical or electromagnetic. Advantageously, the drive motor is a self-braking motor. Advantageously, the drive motor drives a further drive train, which has a free-wheel arrangement or the like.
[0012] Advantageously, the mounting device consists of the mounting and the slider. The mounting and the slider may be fastened to one another, for example by bolts. The mounting and the slider may be of integral construction.
[0013] The invention further provides an apparatus at a draw frame having a drawing mechanism for the doubling and drafting of fibre slivers, having a drawing mechanism frame for accommodating the drawing mechanism, which has at least two pairs of rollers each comprising and upper and a lower roller, having means for adjusting the spacing of at least one of the lower rollers in relation to another lower roller, in each case having a mounting device for accommodating the lower roller, wherein lower rollers are arranged to be driven by at least one drive element endlessly revolving around pulley wheels, characterised in that at least one pulley wheel and the tensioned drive element are used for adjusting the mounting device, wherein a moving force applied to the pulley wheel or to the drive element can be converted into the adjusting movement for the mounting device.
[0014] The invention further provides a draw frame comprising a drawing mechanism according to the invention.
BRIEF DESCRIPTION OF THE DRAWINGS
[0015] [0015]FIG. 1 is a diagrammatic side view of an autoleveller draw frame for use with an apparatus according to the invention together with a general circuit diagram;
[0016] [0016]FIG. 2 is a perspective view of a side of the draw frame showing the displaceable mounting of the intake and middle lower rollers;
[0017] [0017]FIGS. 3 a and 3 b show the drive for the intake and middle lower rollers for the draw frame according to FIG. 1, in a side view (FIG. 3 a ) and plan view (FIG. 3 b );
[0018] [0018]FIG. 3 c is a partial side view of a drive belt;
[0019] [0019]FIGS. 4 a to 4 d show, in diagrammatic form, the sequential procedure for shortening of the preliminary and main draft zones;
[0020] [0020]FIGS. 5 a and 5 b show the intake and middle lower rollers before displacement (FIG. 5 a ) and after displacement (FIG. 5 b );
[0021] [0021]FIGS. 6 a and 6 b show, in diagrammatic form, an electromagnetic braking apparatus for a toothed belt wheel;
[0022] [0022]FIG. 7 shows a locking device for a slider;
[0023] [0023]FIG. 8 shows a connection element (bridge) for connecting two sliders;
[0024] [0024]FIG. 9 is a partial side view of an embodiment comprising a drawing mechanism having three roller combinations, each having its own drive motor;
[0025] [0025]FIG. 10 is a side view of a drawing mechanism with input devices for manual and/or memory-assisted input of adjustment values for changing the nip line spacings in the drawing mechanism; and
[0026] [0026]FIG. 11 is a front view of a roller pair with an upper roller lifted off from a lower roller.
DESCRIPTION OF THE PREFERRED EMBODIMENTS
[0027] In accordance with FIG. 1, a draw frame 1 , for example a draw frame known as an HSR draw frame (trade mark) made by Trützschler GmbH & Co. KG, has a drawing mechanism 2 , upstream of which is an intake 3 of the drawing mechanism and downstream of which is an exit 4 from the drawing mechanism. The fibre slivers 5 , coming from cans (not shown), enter the sliver guide 6 and, drawn by the draw-off rollers 7 , 8 , are transported past the measuring element 9 . The drawing mechanism 2 is designed as a 4-over-3 drawing mechanism, that is to say it consists of three lower rollers I, II, III (I delivery lower roller, II middle lower roller, III intake lower roller) and four upper rollers 11 , 12 , 13 , 14 . Drafting of the fibre sliver combination 5 ′ from a plurality of fibre slivers 5 is carried out in the drawing mechanism 2 . Drafting is composed of preliminary drafting and main drafting. The roller pairs 14 /III and 13 /II form the preliminary draft zone and the roller pairs 13 /II and 11 , 12 /I form the main draft zone.
[0028] The attenuated fibre slivers 5 reach a web guide 10 in the exit 4 from the drawing mechanism and, by means of the draw-off rollers 15 , 16 , are drawn through a sliver funnel 17 , in which they are combined to form one fibre sliver 18 , which is then deposited in cans. Reference letter A denotes the work direction.
[0029] The draw-off rollers 7 , 8 , the intake lower roller III and the middle lower roller II, which are connected to one another mechanically, for example by toothed belts, are driven by the control motor 19 , it being possible, in the process, for a desired value to be specified. (The associated upper rollers 14 and 13 , respectively, revolve by virtue of the motion of the lower rollers.) The delivery lower roller I and the draw-off rollers 15 , 16 are driven by the main motor 20 . The control motor 19 and the main motor 20 each have their own controller 21 and 22 , respectively. Control (speed-of-rotation control) is carried out in each case by means of a closed control loop, a tachogenerator 23 being associated with the control motor 19 and a tachogenerator 24 being associated with the main motor 20 . At the intake 3 of the drawing mechanism, a variable proportional to the weight of the fibre slivers 5 fed in, for example their cross-section, is measured by an intake measuring element 9 known, for example, from DE-A-44 04 326. At the exit 4 from the drawing mechanism, the cross-section of the delivered fibre sliver 18 is ascertained by an exit measuring element 25 associated with the sliver funnel 17 and known, for example, from DE-A-195 37 983. A central computer unit 26 (control and regulation device), for example a microcomputer with a microprocessor, sends a setting for the desired value for the control motor 19 to the controller 21 . The measurement values of the two measuring elements 9 and 25 are sent to the central computer unit 26 during the drawing process. The desired value for the control motor 19 is determined in the central computer unit 26 from the measurement values of the intake measuring element 9 and from the desired value for the cross-section of the delivered fibre sliver 18 . The measurement values of the exit measuring element 25 are used for monitoring of the delivered fibre sliver 18 (delivered sliver monitoring). By means of this control system, it is possible for variations in the cross-section of the fibre slivers 5 fed in to be compensated, and for the fibre sliver to be made more uniform, by appropriately regulating the drafting process. Reference numeral 27 denotes a display monitor, 28 an interface, 29 an input device, 30 a pressure rod and 31 a memory.
[0030] With reference to FIG. 2, each of lower rollers II, III has an associated mounting device comprising a respective mounting 33 a , 34 a . The trunnions Ia, IIa, IIIa (see FIG. 3 b ) of the lower rollers I, II and III are mounted so as to be capable of rotation in mountings 32 a , 33 a , 34 a ( 32 b , 33 b , 34 b are located on the other side of the drawing mechanism and are not shown). The mountings 33 a and 34 a are bolted onto sliders 35 a and 36 a , respectively, which are displaceable in the direction of the arrows C, D and E, F, respectively, along a bar 37 a . The two ends of the bar 37 a are fixedly mounted in mounting blocks 38 ′ ( 38 ″ not shown), which are attached to the frame 39 of the machine.
[0031] Displacement of the sliders 35 a , 35 b ; 36 a , 36 b at the same time causes the mountings 33 a , 33 b ; 34 a , 34 b and, as a result, the lower rollers II and III, respectively, to be displaced and moved in directions C, D and E, F, respectively. The associated upper rollers 13 and 14 are correspondingly moved (in a manner not shown) in directions C, D and E, F, respectively. By that means, the nip line spacings between the roller combinations are modified and set.
[0032] Locking of the sliders 35 a , 35 b ; 36 a , 36 b is accomplished by means of a catch device, stopping device or the like, one suitable form of stopping device being shown in FIG. 7.
[0033] Referring to FIG. 3 a , the lower rollers II and III are driven from the right-hand side of the draw frame, seen in the direction of material flow A, by means of a common loop mechanism in the form of toothed belt wheels 40 , 41 and a toothed belt 47 . The different speeds of rotation of the lower rollers II and III are achieved by means of change-gearwheels at the drive trunnions IIa, IIIa provided with different numbers of teeth. The toothed belt 47 runs in direction B (that is to say contrary to the work direction) onto the control drive, which is in the form of a servo motor 19 . The lower roller I is driven from the left-hand side of the machine by means of a loop mechanism in the form of toothed belt wheels and a toothed belt 47 ′. For that purpose, the toothed belt 47 ′ runs on the left-hand side from the toothed belt disc 40 ′ at the lower roller I in direction G onto the servo motor 20 .
[0034] In operation, that is to say when the fibre slivers are running in direction A, the toothed belt 47 moves in direction G. Starting from the toothed belt wheel 47 arranged on the drive motor 19 , the toothed belt 47 runs successively over a toothed belt wheel 45 , a smooth guide pulley wheel 46 , the toothed belt wheel 40 (roller-driving pulley wheel for the lower roller III), the toothed belt wheel 41 (roller-driving pulley wheel for the lower roller II), a smooth guide pulley wheel 42 and a toothed belt wheel 43 . As shown in FIG. 3 c , the belt 47 has a toothed side 47 a and a smooth side 47 b . By means of its teeth, the toothed belt 47 is in positive engagement with the toothed belt wheels 40 , 41 , 43 , 44 and 45 . The smooth side (reverse) of the toothed belt 47 , opposite the toothed side, is in contact and in engagement with the smooth guide pulley wheels 46 and 42 . The toothed belt 47 loops around all the pulley wheels 40 to 46 . In operation (when the fibre slivers are running in direction A during drafting), the toothed belt wheels 40 , 41 , 43 , 44 and 45 rotate clockwise and the guide pulley wheels 42 and 46 rotate anti-clockwise.
[0035] The toothed belt wheels 40 , 41 are associated with the mountings 34 a and 33 a , respectively, whereas the guide pulley wheels 42 , 46 are attached to the sliders 35 a and 36 a , respectively, in a manner allowing rotation. Because of the rigid attachment between the mounting 34 a and the slider 36 a and between the mounting 33 a and the slider 35 a (for example, by means of bolts), there are associated with the lower rollers II and III, in each case, one toothed belt wheel 40 and 41 , respectively, and one guide pulley wheel 46 and 42 , respectively. The toothed belt 47 runs around the pulley wheels 40 , 46 , on the one hand, and around the pulley wheels 41 , 42 , on the other hand, in a mirror-reflection arrangement (see FIG. 3 b ).
[0036] The zone between the pairs of rollers 13 /II and 14 /III is designated VV (preliminary drafting) and the zone between the pairs of rollers 12 /I and 13 /II is designated HV (main drafting) (see FIG. 4 a ). When, in accordance with FIG. 3 a , the nip line spacing between the roller pairs 14 /III and 13 /II is to be increased, at least one pair of rollers must be moved away from the respective other pair of rollers. For that purpose the slider 35 a may be displaced towards the right, which may be accomplished in two ways:
[0037] a) The slider 35 a is unlocked. A pulley wheel, for example the toothed belt wheel 44 , is stopped so that there is no possibility of rotation. Stopping may be accomplished, for example, by mechanical or electromagnetic means. As a result the toothed belt 47 is stationary and cannot be moved. The toothed belt wheel 41 is then rotated anti-clockwise, for example manually using a crank or the like, whereupon the guide pulley wheel 42 likewise rotates, clockwise, as a matter of necessity. In the process, the rotary movement of the toothed belt wheel 41 is converted into a longitudinal movement of the slider 35 a in direction C, the toothed belt wheel 41 and the guide pulley wheel 42 winding along opposite sides of the stationary toothed belt 47 , thereby “shortening”, as it were, the toothed belt 47 at one pulley wheel and “lengthening” it at the other pulley wheel. The length of belt required during that “winding along” at the toothed belt wheel 41 is made available at the guide pulley wheel 42 . The lower roller II is thereby displaced in direction C by means of the slider 35 a and the mounting 33 a.
[0038] b) The slider 35 a is unlocked. The toothed belt wheel 41 is stopped so that there is no possibility of rotation. As a result the guide pulley wheel 42 is also stopped of necessity. Then, clockwise rotation is brought about by means of the drive motor 19 . The toothed belt 47 moves in direction G, likewise “shortening” the belt 47 at one pulley wheel and “lengthening” it at the other pulley wheel. The length of belt actually required between the toothed belt wheels 40 and 41 is made available between the toothed belt wheels 43 and pulley wheel 42 . The rotary movement of the toothed belt wheel 44 and the movement of the toothed belt 47 is thereby converted into a longitudinal movement of the slider 35 a in direction C. The lower roller II, mounted in the mounting 33 a (which is rigidly connected to the slider 35 a ), is likewise moved in direction C as a result.
[0039] In practice, it is often the case that, in accordance with FIGS. 4 a to 4 d , first the preliminary draft zone VV is modified and then the main draft zone HV. In the case of shortening of the draft zones VV and HV, the slider 36 a is displaced in the direction of the arrow E from the position according to FIG. 4 a into the position according to FIG. 4 b . As a result, the nip line spacing in the preliminary draft zone VV is reduced from “a” to “a”. Then, in accordance with FIG. 4 c , the sliders 36 a and 35 a are rigidly connected to one another by means of a bridge 50 . Finally, the rigidly coupled sliders 36 a and 35 a are moved, in accordance with FIG. 4 d , in the direction of the arrows E and C, from the position shown in FIG. 4 c into the position shown in FIG. 4 d . As a result, the nip line spacing in the main draft zone HV is shortened from “b” to “b”. A corresponding procedure is used in the case of lengthening the preliminary and main draft zones, that is to say the coupled sliders 35 a and 36 a are displaced in the direction of the arrows F and D (see FIG. 2), as a result of which the main draft zone HV is lengthened. Then, the sliders 35 a and 36 a are uncoupled from the bridge 50 . Finally, the slider 36 a is moved in the direction of the arrow F (see FIG. 2), as a result of which the preliminary draft zone VV is lengthened.
[0040] With regard to the fibre slivers 5 in the drawing mechanism 2 , it should be noted that, in the case of shortening of the draft zones VV and HV, a small amount of stretching, in direction B, of the fibre slivers 5 IV upstream of the pair of rollers 14 /III can occur on displacement in accordance with FIGS. 4 a , 4 b , but because of the length (about 1.5 m) of the spacing between the transport rollers 7 , 8 and the pair of rollers 14 /III this is without significance. In the case of shortening, a sagging loop does not form in the preliminary draft zone VV because in the case of displacement referring to the pairs of rollers 14 /III and 13 /II either one or both pairs of rollers are rotatable because the drives to both pairs of rollers are coupled by way of the toothed belt 47 . In contrast, in the case of shortening of the main draft zone HV, a sagging loop is formed in fibre slivers 5 ″, which is drawn out or drawn straight by rotation of the pair of rollers 12 /I in the work direction A by means of the main motor 20 .—In the case of lengthening of the draft zones VV and HV, the pair of rollers 12 /I is, in a first step, rotated backwards in direction B, whereupon a sagging loop is intentionally formed in the fibre slivers 5 ″. When the main draft zone HV is subsequently lengthened by displacement of the coupled sliders 35 a and 36 a in direction D and F, the artificially formed loop is, in the process, once again drawn out or drawn straight. Finally, after uncoupling of the bridge 50 , the slider 36 a is displaced in direction F. As a result of the above-mentioned coupling of the drives to the intake and middle lower roller pairs by means of the toothed belt 47 , the length of the fibre slivers 5 ′ in the preliminary draft zone VV remains unaffected. Possible slight longitudinal compression of the fibre slivers 5 IV upstream of the pair of rollers 14 /III is, in respect of the drafting and the constitution of the fibre slivers 5 IV without significance.
[0041] [0041]FIGS. 5 a , 5 b show a suitable construction for bringing about the displacement of the sliders 36 a and 35 a . The nip line spacing in the preliminary draft zone VV is lengthened from “a” (FIG. 5 a ) to “a” (FIG. 5 b ). The sliders 36 a and 35 a are displaced one after the other according to the arrows E and C, respectively. Displacement is accomplished by stopping the toothed belt wheel 40 or fixing it with a holding brake or the like and then actuating the drive motor 19 , whereupon the toothed belt 47 moves. In continuation thereof, the sliders 36 a and 35 a are displaced in accordance with FIGS. 4 a , 4 b and, subsequently, FIGS. 4 c , 4 d.
[0042] In FIG. 6 a there is shown an electromagnetic holding brake for braking the toothed belt wheel 44 . The brake has a rod-shaped iron core 53 surrounded by a plunger coil 54 . Mounted on one end face of the iron core 53 is a brake shoe 55 , for example made of plastics material or the like. The iron core 53 is displaceable in the direction of the arrows M, N. When current flows through the plunger coil 54 , the iron core 53 is moved in direction M, in accordance with FIG. 6 b , so that the brake shoe 55 is pressed against the smooth cylindrical surface of the shaft 44 a of the toothed belt wheel 44 . As a result, the toothed belt wheel 44 is fixed (stopped) so that it cannot rotate, for as long as voltage is applied to the plunger coil 54 .
[0043] In FIG. 7 there is shown a stopping device for slider 36 a and corresponding lower roller III. A pneumatic cylinder 60 having a piston rod 61 is attached to the slider 36 a . When subjected to pressure from the pneumatic cylinder 60 , the piston rod 61 is moved out in the direction of the arrow P and comes to rest, with a high degree of contact pressure, against the machine frame 61 . The slider 36 a is fixed (stopped) so that it cannot be displaced with respect to the bar 37 a , for as long as compressed air is applied to the pneumatic cylinder 60 . Lower roller II may be provided with an analogous arrangement.
[0044] In accordance with FIG. 8, there is provided, as the bridge 50 between the sliders 35 a and 36 a , a flat piece of metal (plate), which is fastened in the region of one of its ends 50 a to the slider 36 a , for example using bolts. In its region 50 b facing the slider 35 a , the flat piece of metal has an elongate hole 50 c , through which a bolt 62 can engage in a threaded hole (not shown) in the slider 35 a . By means of this bridge 50 , the sliders 35 a and 36 a can be rigidly connected to one another, releasably, at different spacings with respect to one another.
[0045] In accordance with FIG. 9, in contrast to FIG. 1, each lower roller I, II and III is driven by its own drive motor 20 , 52 and 19 , respectively, as shown, for example, in DE-OS 38 01 880. The motor 20 drives the toothed belt wheel 55 of the lower roller I by way of the toothed belt 56 ; the motor 52 drives the toothed belt wheel 41 of the lower roller II by way of the toothed belt 57 ; and the motor 19 drives the toothed belt wheel 40 of the lower roller III by way of the toothed belt 47 . Attached to the slider 36 a , in addition to the smooth guide pulley wheel 46 , is a further smooth guide pulley wheel 51 . The endless toothed belt 47 loops around, in succession, the pulley wheels 44 , 46 , 40 , 51 and 43 . The toothed belt wheels 44 , 40 and 43 are in engagement with the teeth of the toothed belt 47 , whereas the smooth guide pulley wheels 46 and 51 are in engagement with the smooth reverse side of the toothed belt 47 . The sliders 35 a and 36 a are rigidly connected to one another, releasably, by means of the bridge 50 . When they are not connected by the bridge 50 , the sliders 35 a and 36 a are individually displaceable and when they are connected by the bridge 50 they are jointly displaceable.
[0046] In accordance with FIG. 10, the drive motor 19 for lower rollers II and III is in communication with the electronic control and regulation device 26 . Adjustment values for modification of the draft zones VV and HV (that is to say the extents of the drawing zones) either can be entered manually by way of the input device 29 or can be called up from a memory 31 for particular categories of fibre material.
[0047] Adjustment of the nip line spacing in the preliminary draft zone VV and/or the main draft zone HV can be carried out with the fibre slivers 5 inserted.
[0048] Displacement can be carried out with the upper rollers 11 to 14 in the loaded state. FIGS. 1 and 10 show inserted fibre slivers 5 and loaded upper rollers 11 to 14 . With the fibre slivers inserted and the upper rollers 11 to 14 loaded, the sliders 35 a , 36 a or mountings of at least one lower roller II, III are unlocked, the sliders or mountings are set to the desired nip line spacing a, a′; b, b′ by means of a displacement device, for example in accordance with FIGS. 3 a , 3 b ; 5 a , 5 b and then the sliders 35 a , 36 a or mountings are locked again (for example in accordance with FIG. 7).
[0049] Displacement can also be carried out with the upper rollers 11 to 14 lifted off. The upper rollers 11 to 14 may be lifted off completely from the lower rollers I to III in the manner shown in DE-OS 197 04 815, the upper roller 14 being swung out on a portal 58 about a pivot mounting 59 . However, it may also be sufficient for the upper rollers 11 to 14 to be unloaded and to be lifted off from the lower rollers I to III only to a slight degree such that the fibre slivers 5 are not caught by the pairs of rollers during displacement of the draft zones VV and HV but can slide through the roller nip without being adversely affected.
[0050] The invention has been illustrated using the example of the adjustment of the nip line spacings of a drawing mechanism of a draw frame. It likewise encompasses the adjustment of drawing mechanisms of other machines, for example carding machines, combing machines, fly frames and ring spinning frames.
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A drawing mechanism for the doubling and drafting of fibre slivers, has a drawing mechanism frame for accommodating the drawing mechanism, which has at least two pairs of rollers each comprising an upper roller, and a lower roller, and has means for adjusting the spacing of at least one of the lower rollers in relation to another lower roller, in each case having a mounting device for accommodating the lower roller, wherein lower rollers are arranged to be driven by a drive device comprising at least one drive element endlessly revolving around pulley wheels.
In order, by simple means in terms of construction, to make possible a considerable reduction in the work and time required for adjustment of the lower roller(s) and, accordingly, of the extent(s) of the drawing zone(s), the mounting device(s) are made adjustable by the drive device.
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CROSS-REFERENCE TO RELATED APPLICATIONS
[0001] This continuation application is a continuation of U.S. patent application Ser. No. 14/010,353 filed on Aug. 26, 2013 which is a continuation of U.S. patent application Ser. No. 13/444,023 filed on Apr. 11, 2012 now U.S. Pat. No. 8,519,819 which is a continuation of U.S. patent application Ser. No. 11/838,475 now U.S. Pat. No. 8,183,982 and claims the benefit of the priority date of the above application, the contents of which are herein incorporated in its full entirety by reference.
BACKGROUND
[0002] Typically, an electrical system includes a number of different components that communicate with one another to perform system functions. The different components may be situated on the same integrated circuit chip or on different integrated circuit chips. Usually, an electrical system, such as the electrical system in an automobile, includes one or more controllers, memory chips, sensor circuits, and actor circuits. The controller digitally communicates with the memory chips, sensors, and actors to control operations in the automobile.
[0003] In digital communications a common time base is used to transmit and receive data. The common time base needs to be provided to each of the components and can be provided to each of the components via an explicit clock signal or by combining the time base with the transmitted data. A transmitter transmits data via the common time base and a receiver receives and decodes the data via the common time base. The received data cannot be properly decoded without the common time base.
[0004] Another aspect of digital communications includes the start time of a data transmission. If the transmission start time is not coded on the common time base signal or in the data, another signal line is used to indicate the start of a data transmission. Many embedded systems include a common system clock and selection signals that select system components and indicate the start of data transmissions.
[0005] Often, in decentralized systems, a multi-wire communication system, such as a serial peripheral interface (SPI), is used. Typically, a master provides a clock signal and a slave select signal to each component via separate signal lines. The master toggles the clock signal coincident with transmitted data and the slave select signals select components and indicate the beginning and/or end of a data transmission. In operation of an SPI system, the master configures the clock signal to a frequency that is less than or equal to the maximum frequency of a slave and pulls the slave's select line low. The master selects one slave at a time. If a waiting period is required, the master waits for the waiting period before issuing clock cycles. During each clock cycle a full duplex data transmission occurs, where the master sends a bit on one line and the slave reads the bit from the one line and the slave sends a bit on another line and the master reads the bit from the other line. Transmissions include any number of clock cycles and when there are no more data to be transmitted, the master deselects the slave and stops toggling the clock signal.
[0006] Separate clock and select signal lines to each of the components can be used to provide bus ability. In addition, in these systems the masters can send data to the slaves. However, separate signal lines increase costs and manufacturers want to reduce costs.
[0007] To avoid using a separate clock line, the time base can be encoded into the data. For example, Manchester encoding is a bit-synchronous transmission method where data is transmitted bit by bit using a given bit rate. In Manchester encoding, each bit is represented by either a rising edge or a falling edge of an electrical signal, where the rising edge represents one of a logical one or a logical zero and the falling edge represents the other one of a logical one or a logical zero. Between bits the electrical signal may need to transition to transfer the next bit and it is necessary to distinguish between edges that represent bits and edges that are signal changes between bits. This is achieved by starting the transmission with a known bit sequence, referred to as a preamble. However, the preamble mechanism is for only a one-way transmission and the receiver is not able to control the start time of the transmission. Also, the transmission requires twice the frequency of the bit rate and high frequencies introduce electromagnetic interference (EMI) problems. In addition, dedicated circuits are needed, since it is difficult to encode and decode the data using typical peripheral elements found on embedded controllers.
[0008] For these and other reasons there is a need for the present invention.
SUMMARY
[0009] According to one aspect, a sensor comprises a transmitter to transmit signals over a communication path, the sensor further capable to receive signals from the communication path, wherein the sensor is configured to communicate sensor data having a nibble data signal format at the transmitter in response to a trigger signal received at the sensor.
[0010] According to a further aspect, a sensor comprises a transmitter to transmit signals over a communication path, the sensor further comprising circuitry to receive signals from the communication path, wherein the sensor is configured to communicate sensor data over a communication path by transmitting a pulse width modulated data signal in response to a trigger signal which is received at the sensor.
BRIEF DESCRIPTION OF THE DRAWINGS
[0011] The accompanying drawings are included to provide a further understanding of embodiments and are incorporated in and constitute a part of this specification. The drawings illustrate embodiments and together with the description serve to explain principles of embodiments. Other embodiments and many of the intended advantages of embodiments will be readily appreciated as they become better understood by reference to the following detailed description. The elements of the drawings arc not necessarily to scale relative to each other. Like reference numerals designate corresponding similar parts.
[0012] FIG. 1 is a diagram illustrating one embodiment of an electrical system according to the present invention.
[0013] FIG. 2 is a block diagram illustrating a request signal and a reply signal in one embodiment of an electrical system.
[0014] FIG. 3 is a diagram illustrating a reply signal that is transmitted via one embodiment of a transmitter.
[0015] FIG. 4 is a diagram illustrating one embodiment of an electrical system that includes a controller, a first sensor, and a second sensor.
[0016] FIG. 5 is a timing diagram illustrating the operation of one embodiment of the electrical system of FIG. 4 .
DETAILED DESCRIPTION
[0017] In the following Detailed Description, reference is made to the accompanying drawings, which form a part hereof, and in which is shown by way of illustration specific embodiments in which the invention may be practiced. In this regard, directional terminology, such as “top,” “bottom,” “front,” “back,” “leading,” “trailing,” etc., is used with reference to the orientation of the Figure(s) being described. Because components of embodiments can be positioned in a number of different orientations, the directional terminology is used for purposes of illustration and is in no way limiting. It is to be understood that other embodiments may be utilized and structural or logical changes may be made without departing from the scope of the present invention. The following detailed description, therefore, is not to be taken in a limiting sense, and the scope of the present invention is defined by the appended claims.
[0018] It is to be understood that the features of the various exemplary embodiments described herein may be combined with each other, unless specifically noted otherwise.
[0019] FIG. 1 is a diagram illustrating one embodiment of an electrical system 20 according to the present invention. In one embodiment, system 20 is part of an automobile's electrical system.
[0020] System 20 includes a receiver 22 and a transmitter 24 . Receiver 22 is communicatively coupled to transmitter 24 via one or more communication paths at 26 . In one embodiment, receiver 22 is part of one integrated circuit chip and transmitter 24 is part of another integrated circuit chip. In one embodiment, receiver 22 and transmitter 24 are part of the same integrated circuit chip. In one embodiment, receiver 22 is a controller. In one embodiment, transmitter 24 is a sensor, such as an automobile sensor. In one embodiment, transmitter 24 is an actor, such as a relay circuit. In one embodiment, transmitter 24 is a controller. In other embodiments, receiver 22 and transmitter 24 are any suitable components.
[0021] Receiver 22 transmits a request signal to transmitter 24 via one of the communication paths at 26 and transmitter 24 transmits a reply signal to receiver 22 via one of the communication paths at 26 . The reply signal includes a synchronization signal that indicates the time base of transmitter 24 and data. The request signal and the reply signal overlap in time, where at least a portion of the request signal occurs at the same time as at least a portion of the reply signal. In one embodiment, the request signal and the synchronization signal overlap in time, where at least a portion of the request signal occurs at the same time as at least a portion of the synchronization signal.
[0022] Transmitter 24 transmits data correlated to the time base of transmitter 24 , where the length of the synchronization signal indicates the time base of transmitter 24 and the length of each data signal represents data bits. In one embodiment, each data signal represents a nibble of data, i.e. four data bits.
[0023] Receiver 22 receives the synchronization signal and measures the length of the synchronization signal to obtain the time base of transmitter 24 . Based on the received time base, receiver 22 recovers data bit information from the data signals via measuring the length of the data signals and comparing the measured length to the received time base of transmitter 24 . In one embodiment, the request signal includes a trigger signal and transmitter 24 starts the reply signal in response to the trigger signal. In one embodiment, the request signal includes a trigger signal and transmitter 24 starts the synchronization signal in response to the trigger signal. In one embodiment, the request signal includes a trigger signal and the length of the synchronization signal is measured from the trigger signal to the end of the synchronization signal provided via transmitter 24 .
[0024] In one embodiment, receiver 22 transmits one or more commands and/or data to transmitter 24 in the request signal. In one embodiment, the request signal includes one or more transmitter identification values to select one or more of multiple transmitters, which provides bus ability in system 20 . In one embodiment, the request signal includes data request parameters, such as sensor measurement range information that directs the transmitter to switch to a different sensor measurement range or transmit data in the specified sensor measurement range. In one embodiment, the request signal includes configurable parameters, such as relay turn-on/off time that directs a relay to remain on/off for a specified time. In one embodiment, the request signal includes commands, such as a self-test signal that directs the transmitter to perform a self-test or a memory test. In one embodiment, the request signal includes a wake-up signal that powers up the transmitter from a sleep mode or power down mode. In one embodiment, the request signal includes a power down signal to power down the transmitter or put the transmitter in a power saving sleep mode. In one embodiment, the request signal includes a send data and remain powered-up signal. In one embodiment, the request signal includes a send data and power down signal.
[0025] In one embodiment, receiver 22 transmits a request and transmitter 24 transmits a pulse width modulated reply signal that includes a synchronization pulse followed by one or more data pulses. The synchronization pulse is the synchronization signal, where the length of the synchronization pulse represents the time base, i.e. clock speed, of transmitter 24 . Each of the data pulses represents one or more data bits of information, such as transmitter status, transmitter data, and checksum information. The request signal overlaps in time the pulse width modulated reply signal and the synchronization signal. Receiver 22 receives the pulse width modulated reply signal and measures the lengths of the synchronization pulse and the data pulses to recover data bit information.
[0026] Receiver 22 transmits the request via one of the communication paths 26 and transmitter 24 transmits the reply signal via one of the communication paths 26 . In one embodiment, receiver 22 and transmitter 24 are communicatively coupled via one or more conductive lines, where each of the conductive lines is a communications path. In one embodiment, receiver 22 and transmitter 24 are communicatively coupled via one or more radio frequency (RF) frequencies, where each of the RF frequencies is a communications path. In one embodiment, receiver 22 and transmitter 24 are communicatively coupled via one or more optical wavelengths, where each wavelength (color) is a communications path. In one embodiment, receiver 22 and transmitter 24 are communicatively coupled via magnetic signals. In one embodiment, receiver 22 and transmitter 24 are communicatively coupled via pressure signals.
[0027] In one embodiment, receiver 22 transmits the request via one communications path and transmitter 24 transmits the reply signal via the same communications path. In one embodiment, receiver 22 transmits the request via a first communications path and transmitter 24 transmits the reply signal via a second communications path.
[0028] Receiver 22 and transmitter 24 communicate to send a request signal from receiver 22 to transmitter 24 and a reply signal from transmitter 24 to receiver 22 . In other embodiments, receiver 22 is configured to send a request signal from receiver 22 to transmitter 24 and a reply signal from receiver 22 to transmitter 24 , and transmitter 24 is configured to send a request signal from transmitter 24 to receiver 22 and a reply signal from transmitter 24 to receiver 22 .
[0029] System 20 provides data communications between receiver 22 and transmitter 24 via a single communications path, such as one conductive line, or two communication paths, such as two conductive lines. These data communications have a high tolerance to time base differences between receiver 22 and transmitter 24 . Also, the request signal and the synchronization signal provide synchronization of the data communications and the request signal provides for the transmission of commands and/or data from receiver 22 to transmitter 24 . In addition, the request signal can include transmitter identifications that can be used in communications from a receiver to multiple transmitters, i.e. bus ability.
[0030] FIG. 2 is a block diagram illustrating a request signal 50 and a reply signal 52 in one embodiment of system 20 . Reply signal 52 includes a synchronization signal 54 and data signals 56 . Synchronization signal 54 is a time base signal that indicates the time base of transmitter 24 . Each of the data signals 56 is correlated to the time base indicated via synchronization signal 54 .
[0031] Receiver 22 transmits request signal 50 to transmitter 24 via one of the communication paths 26 and transmitter 24 transmits reply signal 52 to receiver 22 via one of the communication paths 26 . In response to a trigger signal at 58 in request signal 50 , transmitter 24 starts synchronization signal 54 . After reaching a pre-determined internal count value, transmitter 24 transmits a trailing edge at 60 in synchronization signal 54 . The length of synchronization signal 54 , from trigger signal 58 to trailing edge 60 , indicates the time base or clocking speed of transmitter 24 . In one embodiment, transmitter 24 uses the indicated time base to transmit data signals 56 , which correlates data signals 56 to the time base indicated by synchronization signal 54 .
[0032] Receiver 22 transmits the remainder of request signal 50 after trigger signal 58 . The remainder of request signal 50 includes any commands and/or data to be transmitted to transmitter 24 , such as transmitter identification values, data request parameters such as a sensor measurement range, configurable parameters such as a relay turn-on/off time, and commands such as a self-test signal, a wake-up signal, a power down signal, a send data and remain powered-up signal, or a send data and power down signal. Request signal 50 overlaps in time at least a portion of synchronization signal 54 and if receiver 22 and transmitter 24 transmit via the same communications path, a trailing edge at 62 in request signal 50 occurs before the trailing edge 60 of synchronization signal 54 is transmitted via transmitter 24 on the same communications path. If receiver 22 and transmitter 24 transmit via different communication paths, the trailing edge 62 of request signal 50 can occur before or after the trailing edge 60 of synchronization signal 54 is transmitted via transmitter 24 .
[0033] In one embodiment, receiver 22 is electrically coupled to transmitter 24 via one or more conductive lines and receiver 22 transmits request signal 50 on a first conductive line via voltage signals, such as voltage pulses or voltage bursts. Voltage signals on the first conductive line is a communications path. Request signal information is coded into the amplitude and/or length of the voltage pulses or coded into the amplitude, length, and/or frequency of the voltage bursts. Transmitter 24 transmits reply signal 52 via voltage signals, such as a pulse width modulated voltage signal, voltage pulses, or voltage bursts. Where leading and trailing edge information of synchronization signal 54 and data signals 56 are coded into the amplitude and/or length of the voltage pulses or the amplitude, length, and/or frequency of the voltage bursts. Receiver 22 and transmitter 24 generate the voltage signals via suitable circuitry, such as level-switching power stages, operational amplifiers, resistor networks, or open-drain/open-collector interfaces including pull-ups. Also, receiver 22 and transmitter 24 receive the voltage signals via suitable circuitry, such as window-detectors, schmitt-triggers, or open-drain/open-collector interfaces including pull-ups. If transmitter 24 transmits reply signal 52 via the first conductive line, request signal 50 and reply signal 52 share the same communications path and request signal 50 ends before the trailing edge 60 of synchronization signal 54 . If transmitter 24 transmits reply signal 52 via a second conductive line, request signal 50 and reply signal 52 do not share the same communications path and request signal 50 can end before or after the trailing edge 60 of synchronization signal 54 .
[0034] In one embodiment, receiver 22 is electrically coupled to transmitter 24 via a conductive line and receiver 22 transmits request signal 50 on the conductive line via voltage signals, such as voltage pulses or voltage bursts. The voltage signals on the conductive line are a first communications path. Request signal information is coded into the amplitude and/or length of the voltage pulses or coded into the amplitude, length, and/or frequency of the voltage bursts. Transmitter 24 transmits reply signal 52 via current signals, such as current pulses or current bursts, where leading and trailing edge information of synchronization signal 54 and data signals 56 are coded into the amplitude and/or length of the current pulses or the amplitude, length, and/or frequency of the current bursts. The current pulses on the conductive line are a second communications path, such that request signal 50 and reply signal 52 do not share the same communications path and request signal 50 can end before or after the trailing edge 60 of synchronization signal 54 .
[0035] In one embodiment, receiver 22 is communicatively coupled to transmitter 24 via antennae and one or more RF frequencies and receiver 22 transmits request signal 50 via a first RF frequency. The first RF frequency is a first communications path and request signal 50 is coded into the amplitude, length, and/or frequency of the RF signal or coded into the frequency/modulation factor, length, or amplitude of an RF modulated signal. Transmitter 24 transmits reply signal 52 via an RF frequency, where leading and trailing edges of synchronization signal 54 and data signals 56 are coded into the amplitude, length, and/or frequency of the RF signal or coded into the frequency/modulation factor, length, or amplitude of an RF modulated signal. If transmitter 24 transmits reply signal 52 via the first RF frequency, request signal 50 and reply signal 52 share the same communications path and request signal 50 ends before the trailing edge 60 of synchronization signal 54 . If transmitter 24 transmits reply signal 52 via a second RF frequency, request signal 50 and reply signal 52 do not share the same communications path and request signal 50 can end before or after the trailing edge 60 of synchronization signal 54 .
[0036] In one embodiment, receiver 22 is communicatively coupled to transmitter 24 via an optical coupling, such as LED's or glass fibre, and one or more wavelengths (color). Receiver 22 transmits request signal 50 via a first wavelength, which is one communications path. Request signal 50 is coded into the amplitude, length, intensity, and/or burst frequency of the optical signal. Transmitter 24 transmits reply signal 52 via an optical wavelength, where leading and trailing edges of synchronization signal 54 and data signals 56 are coded into the amplitude, length, intensity, and/or burst frequency of the optical signal. If transmitter 24 transmits reply signal 52 via the first wavelength, request signal 50 and reply signal 52 share the same communications path and request signal 50 ends before the trailing edge 60 of synchronization signal 54 . If transmitter 24 transmits reply signal 52 via a second wavelength, request signal 50 and reply signal 52 do not share the same communications path and request signal 50 can end before or after the trailing edge 60 of synchronization signal 54 .
[0037] In one embodiment, receiver 22 is communicatively coupled to transmitter 24 via a magnetic coupling, such as a coil, Receiver 22 transmits request signal 50 via the magnetic coupling, which is one communications path. Request signal 50 is coded into the amplitude, length, intensity, and/or frequency of the magnetic signal. Transmitter 24 transmits reply signal 52 via the magnetic coupling, where leading and trailing edges of synchronization signal 54 and data signals 56 are coded into the amplitude, length, intensity, and/or frequency of the magnetic signal. Request signal 50 and reply signal 52 share the same communications path and request signal 50 ends before the trailing edge 60 of synchronization signal 54 .
[0038] In one embodiment, receiver 22 is communicatively coupled to transmitter 24 via a pressure coupling, such as piezo actor/sensor combinations or loudspeaker/microphone combinations. Receiver 22 transmits request signal 50 via the pressure coupling, which is one communications path. Request signal 50 is coded into the amplitude, length, intensity, and/or frequency of the pressure pulse signal. Transmitter 24 transmits reply signal 52 via the pressure coupling, where leading and trailing edges of synchronization signal 54 and data signals 56 are coded into the amplitude, length, intensity, and/or frequency of the pressure pulse signal. Request signal 50 and reply signal 52 share the same communications path and request signal 50 ends before the trailing edge 60 of synchronization signal 54 .
[0039] In other embodiments, receiver 22 and transmitter 24 are suitably communicatively coupled. If they share the same communications channel or path, request signal 50 ends before the trailing edge 60 of synchronization signal 54 . If they do not share the same communications channel or path, request signal 50 ends before or after the trailing edge 60 of synchronization signal 54 .
[0040] In another embodiment of system 20 , the synchronization signal is transmitted between data signals. Transmitter 24 starts transmitting data signals in response to a trigger signal in the request signal. Next, transmitter 24 transmits a synchronization signal and the remainder of the data signals. Some of the data signals are received and stored in receiver 22 prior to receiving the synchronization signal. The stored data signals are decoded after the synchronization signal is received from transmitter 24 . Also, at least a portion of the request signal overlaps in time at least a portion of the reply signal and one or more data signals.
[0041] In another embodiment of system 20 , the synchronization signal is transmitted after the data signals. Transmitter 24 starts transmitting data signals in response to a trigger signal in the request signal. After transmitting the data signals, transmitter 24 transmits a synchronization signal. The data signals are received and stored in receiver 22 and decoded after the synchronization signal is received from transmitter 24 . Also, at least a portion of the request signal overlaps in time at least a portion of the reply signal and one or more data signals.
[0042] FIG. 3 is a diagram illustrating a reply signal 70 that is transmitted via one embodiment of transmitter 24 . Reply signal 70 includes synchronization signal 72 , data signal D 1 at 74 , data signal D 2 at 76 , and data signal D 3 at 78 . The data signals D 1 at 74 , D 2 at 76 , and D 3 at 78 include transmitter information, such as transmitter status, data, and checksum information. Each of the data signals D 1 at 74 , D 2 at 76 , and D 3 at 78 represents one or more data bits. Synchronization signal 72 provides a reference time tREF at 72 that indicates the time base of transmitter 24 . Each of the data signal times tD 1 at 74 , tD 2 at 76 , and tD 3 at 78 correlates to reference time tREF at 72 . In one embodiment, each of the data signals D 1 at 74 , D 2 at 76 , and D 3 at 78 represents a nibble of data, i.e. four data bits.
[0043] Receiver 22 transmits a request signal (not shown) to transmitter 24 via one of the communication paths 26 . In response to a trigger signal in the request signal, transmitter 24 provides a falling edge signal at 80 and a rising edge signal at 82 in synchronization signal 72 . After reaching a reference count, transmitter 24 transmits a trailing falling edge signal at 84 . The length of synchronization signal 72 , from the falling edge at 80 to the falling edge at 84 is reference time tREF at 72 . Synchronization signal 72 is made to be distinguishable from each of the data signals D 1 at 74 , D 2 at 76 , and D 3 at 78 . In one embodiment, reference time tREF at 72 is the longest pulse width that can be provided via transmitter 24 . In one embodiment, reference time tREF at 72 is the shortest pulse width that can be provided via transmitter 24 .
[0044] Receiver 22 transmits the remainder of the request signal after the falling edge at 80 . The remainder of the request signal includes any commands and/or data to be transmitted to transmitter 24 . The request signal overlaps in time at least a portion of synchronization signal 72 . If receiver 22 and transmitter 24 transmit via the same communications path, the trailing edge of the request signal occurs before the trailing falling edge at 84 . If receiver 22 and transmitter 24 transmit via different communication paths, the trailing edge of the request signal can occur before or after the trailing falling edge at 84 . In one embodiment, receiver 22 and transmitter 24 are electrically coupled via one conductive line and they communicate via open drain/collector transistors with pull-up resistors, where the remainder of the request signal is transmitted after the rising edge at 82 and before the falling edge at 84 .
[0045] Transmitter 24 transmits data signal D 1 at 74 , data signal D 2 at 76 , and data signal D 3 at 78 . The length of data signal D 1 at 74 , from the falling edge at 84 to a falling edge at 86 , is data signal time tD 1 at 74 . The length of data signal D 2 at 76 , from the falling edge at 86 to a falling edge at 88 , is data signal time tD 2 at 76 . The length of data signal D 3 at 78 , from the falling edge at 88 to a falling edge at 90 , is data signal time tD 3 at 78 . Each of the data signal times tD 1 at 74 , tD 2 at 76 , and tD 3 at 78 correlates to reference time tREF at 72 .
[0046] In other embodiments, synchronization signal 72 is transmitted between or after data signals, such as data signals D 1 at 74 , D 2 at 76 , and D 3 at 78 . The data signals received before synchronization signal 72 are stored and decoded after receiving synchronization signal 72 . Also, at least a portion of the request signal overlaps in time at least a portion of the reply signal and one or more of the data signals.
[0047] FIG. 4 is a diagram illustrating one embodiment of an electrical system 100 , which includes a controller 102 , a first sensor 104 , and a second sensor 106 . Controller 102 is electrically coupled to each of the sensors 104 and 106 via a 3-wire connection. Controller 102 is electrically coupled to first sensor 104 and second sensor 106 via VDD power supply line 108 , data line 110 , and a reference line, such as ground line 112 . In one embodiment, system 100 is part of an automobile's electrical system. In other embodiments, controller 102 is electrically coupled to any suitable number of sensors.
[0048] Controller 102 communicates with first sensor 104 and second sensor 106 via open-drain/open-collector interfaces including one or more pull-up resistors. For example, system 100 includes pull-up resistor 114 that has a first end electrically coupled to power supply line 108 and a second end electrically coupled to data line 110 , and controller 102 includes an open-drain transistor 116 that has one end of its drain-source path electrically coupled to data line 110 and the other end electrically coupled to ground line 112 . Controller 102 and each of the first and second sensors 104 and 106 share a single communications path that is communicating via voltage signals on data line 110 .
[0049] Controller 102 transmits a request signal that is received by the first and second sensors 104 and 106 via data line 110 . The request signal includes a trigger signal and a sensor identification signal that selects one of the first and second sensors 104 and 106 . In addition, the remainder of the request signal includes any other commands and/or data to be transmitted to the selected sensor, such as data request parameters such as a sensor measurement range, configurable parameters such as a relay turn-on/off time, and commands such as a self-test signal, a wake-up signal, a power down signal, a send data and remain powered-up signal, or a send data and power down signal. Controller 102 and each of the first and second sensors 104 and 106 share a single communications path such that the request signal ends before the trailing edge of the synchronization signal.
[0050] The first and second sensors 104 and 106 receive the request signal including the trigger signal and the sensor identification signal. One of the first and second sensors 104 and 106 is selected via the sensor identification signal and the selected sensor transmits a reply signal via data line 110 . In one embodiment, the reply signal is similar to reply signal 70 of FIG. 3 .
[0051] The reply signal includes a synchronization signal and data signals. The data signals include sensor information, such as sensor status, sensor data, and checksum information. The length of the synchronization signal provides a reference time that indicates the time base of the selected sensor. Each of the data signal lengths correlates to the reference time. In one embodiment, each of the data signals represents a nibble of data, i.e. four data bits.
[0052] The request signal and the synchronization signal overlap in time, where at least a portion of the request signal occurs at the same time as at least a portion of the synchronization signal. In response to the trigger signal, the selected sensor starts the synchronization signal and after reaching a reference count transmits the trailing falling edge of the synchronization signal to mark the end of the synchronization signal. The request signal ends before the trailing falling edge of the synchronization signal.
[0053] In one embodiment, the length of the synchronization signal is measured from the trigger signal to the trailing falling edge of the synchronization signal. In one embodiment, the selected sensor transmits a falling edge followed by a rising edge to start the synchronization signal. In one embodiment, the selected sensor transmits a high voltage value at the start of the synchronization signal and the length of the synchronization signal is measured from the trigger signal to the trailing falling edge of the synchronization signal. In one embodiment, the length of the synchronization signal is the longest pulse that can be provided via the selected sensor.
[0054] In another embodiment, a data signal is transmitted first in the reply signal, where at least a portion of the request signal occurs at the same time as at least a portion of the data signal. In response to the trigger signal, the selected sensor starts the data signal and after reaching an end count for the data signal transmits the trailing falling edge of the data signal. The request signal ends before the trailing falling edge of the data signal.
[0055] Controller 102 receives the synchronization signal and measures the length of the synchronization signal to obtain the time base of the selected sensor. Based on the received time base, controller 102 recovers data from the data signals via measuring the length of the data signals and comparing the measured length to the received time base.
[0056] In other embodiments, controller 102 transmits the request signal via VDD power supply line 108 and first and second sensors 104 and 106 transmit reply signals via data line 108 .
[0057] FIG. 5 is a timing diagram illustrating the operation of one embodiment of system 100 of FIG. 4 . Controller 102 communicates with first and second sensors 104 and 106 via data line 110 . In one communication sequence, controller 102 selects one of the first and second sensors 104 and 106 and the selected sensor provides sensor functions at 130 . Controller 102 and the selected sensor transmit data line signal 132 via data line 110 . Data line signal 132 is further described in the logical description at 134 .
[0058] At 136 , first and second sensors 104 and 106 are idle and controller 102 transmits a request signal that includes a trigger signal, a sensor identification signal, and a sensor range signal. The falling edge at 138 in data line signal 132 is the trigger signal. The length tID at 140 of the low voltage level following the falling edge at 138 and ending at a rising edge at 142 is the sensor identification signal. The length tR at 144 of the low voltage level from the falling edge at 146 to a rising edge at 148 is the sensor range signal.
[0059] In response to the trigger signal falling edge at 138 , first and second sensors 104 and 106 start transmitting synchronization signals at 150 . In one embodiment, each of the synchronization signals includes a falling edge followed by a rising edge to start the synchronization signal. In one embodiment, each of the synchronization signals includes a high voltage level at the start of the synchronization signal.
[0060] At 152 , each of the first and second sensors 104 and 106 checks the low voltage level time tID at 140 of the identification signal. The selected sensor continues on to check the low voltage level time tR at 144 of the sensor range signal, which indicates the sensor range to use in data transmissions. Next, the selected sensor transmits a falling edge at 154 that ends the synchronization signal of the selected sensor and the synchronization period 156 .
[0061] Controller 102 receives the falling edge at 154 of the synchronization signal and obtains the time base of the selected sensor. In one embodiment, the length of the synchronization signal is measured from the trigger signal falling edge at 138 to the trailing falling edge at 154 of the synchronization signal.
[0062] The selected sensor transmits data signals at 158 , where each of the data signals has a length that indicates the bit value of the data signal. The first data signal at 160 is a status signal that indicates the status of the selected sensor. The length of the status signal at 160 begins with the falling edge at 154 and ends with a falling edge at 162 . The length of the second data signal DATA 2 at 164 begins with the falling edge at 162 and ends with a falling edge at 166 , and so on, up to the final data signal DATAx at 168 and a checksum signal at 170 . The length of the checksum signal at 170 begins with a falling edge at 172 and ends with a falling edge at 174 . At 176 , a zero signal begins with the falling edge at 174 and ends at a high voltage level. The data signals end at 178 and the selected sensor is idle at 180 .
[0063] Controller 102 receives the data signals at 158 via data line signal 132 . Controller 102 measures the length of each of the data signals 158 from one falling edge to the next falling. Based on the received time base, controller 102 recovers the data bit values of each of the data signals 158 .
[0064] System 100 provides data communications between controller 102 and first and second sensors 104 and 106 via the single communications path of data line 110 . The data communications have a high tolerance to time base differences between controller 102 and the first and second sensors 104 and 106 . Also, the request signal and the synchronization signal provide synchronization of the data communications and the request signal provides for the transmission of commands and/or data from controller 102 to first and second sensors 104 and 106 . In addition, the request signal includes sensor identification signals that provide bus ability.
[0065] Although specific embodiments have been illustrated and described herein, it will be appreciated by those of ordinary skill in the art that a variety of alternate and/or equivalent implementations may be substituted for the specific embodiments shown and described without departing from the scope of the present invention. This application is intended to cover any adaptations or variations of the specific embodiments discussed herein. Therefore, it is intended that this invention be limited only by the claims and the equivalents thereof.
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A sensor comprises a transmitter to transmit signals over a communication path, the sensor further capable to receive signals from the communication path, wherein the sensor is configured to communicate sensor data having a nibble data signal format at the transmitter in response to a trigger signal received at the sensor.
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BACKGROUND OF THE INVENTION
This invention relates to game ball launching devices and in particular to a device wherein a football is launched into an airborne trajectory.
In the past many ball launching devices have been provided for projecting a series of balls at regular intervals for the purpose of permitting a novice or professional player to practice the game without the necessity of having available another player to throw the ball.
A number of machines also have been constructed in the past for launching a football into a predetermined trajectory. However, most of these machines were of the centering type for practice by a quarterback in receiving the ball from the center position, as disclosed by Maxcey in U.S. Pat. No. 2,767,985, or of the type that simulates a kick-off or a punt, as disclosed by Retrum in U.S. Pat. No. 3,662,728. Heretofore, no football launching device has been provided which would simulate the trajectory of a hand thrown football, as that in a pass play, for imparting a spiral spin to the football.
SUMMARY OF THE INVENTION
The launching device, according to the present invention, includes a support housing enclosing a spring-biased pivotally mounted catapult arm with a spin imparting means in the form of a basket secured to the end thereof which imparts a spiral spin to the football as it is launched. The catapult arm is manually retracted against the force of the spring and is maintained in a cocked retracted position by a locking mechanism. The locking mechanism is operatively associated with a governor which delays the launching of the ball for a predetermined time period to allow the user the position himelf for receiving the launched ball.
The launching device also includes elevation adjustments and spring tension adjustments to vary the trajectory of the launched football.
Thus, it is the object of this invention to provide a new and improved football launching device which can launch a football into an airborne trajectory and at the same time impart a spiral spin to the football as is associated with the normal pass play in the game of football.
Other objects, features and advantages of the invention will be apparent from the following detailed description taken in connection with the accompanying drawings.
BRIEF DESCRIPTION OF THE DRAWINGS
FIG. 1 is a perspective view of the football launching device of the present invention;
FIG. 2 is a vertical section, on an enlarged scale, taken generally along the line 2--2 of FIG. 1;
FIG. 3 is a vertical section taken generally along the line 3--3 of FIG. 2;
FIG. 4 is a vertical section taken generally along the line 4--4 of FIG. 2;
FIG. 5 is a horizontal section taken generally along the line 5--5 of FIG. 2; and
FIG. 6 is a vertical section, similar to FIG. 4, illustrating the launching device in its cocked position.
DESCRIPTION OF THE PREFERRED EMBODIMENT
The launching device of the present invention, generally designated 10, includes a base structure in the form of a substantially hollow, generally rectangular housing, generally designated 12, formed of sheet metal, plastic, or the like. The housing includes two side walls 14, a front wall 16 and a rear wall 18 which curves into a top wall 20. A rectangular opening 21 is provided at the top front wall 16 of the housing for loading a football 22 (FIG. 6) therethrough and also through which the football 22 is launched. A catapult means, generally designated 24, is pivotally mounted within the housing for launching the football 22. The catapult means 24 is associated with a delaying governor, generally designated 28, which delays the launching of the football 22, after the catapult means is cocked to permit a user to move away from the device 10 for receiving the football 22. An interlocking mechanism, generally designated 30 (FIGS. 2, 3, 4, 5 and 6) is associated with the governor 28 and prevents the launching of any object which is not the same size and shape as a football for which the device is designed.
The front wall 16 of the housing includes a partially overlapping adjustable slide section 31 for varying the attitude of the launching device 10. The adjustable slide section 31 includes a boss 32 provided with internal threads. An elevation knob 33 is provided with a threaded shaft 33a (FIG. 3) threaded into boss 32 to clamp the adjustable slide section 31 against the front wall and lock the section 31 in any desired position. This establishes the height of the front of the device relative to its supporting surface and thus the "elevation" control for the device.
Looking to FIGS. 2, 4 and 6, the catapult means 24 includes a catapult arm 34 which is pivotally mounted midway between the side walls 14 by a shaft 36 journalled in holes 38 on the side walls 14. The upper end of the catapult arm 34 includes a curved section 40 which supports a spin imparting means, generally designated 42. The spin imparting means 42 is formed in the shape of a basket and is secured to the catapult arm 34 by bolts or rivets 44. The basket 42 is generally in the shape of a section of an ellipsaid and includes two relatively large cutouts 46. Actually the basket is shaped with the contour of football, but less than half thereof in reference to a plane through the longitudinal axis of the football. The cutouts 46 serve to prevent the launching of small object such as rocks, baseballs or the like which will fall through the cutouts. A catapult spring 48 is coiled around the shaft 36 and is hooked around the catapult arm 34 at 48a at one end. The other end 48b of the spring 48 extends through the front wall 16 of the housing through an adjustment slot 50 which allows the end of the spring 48 to be set in a plurality of positions, defined by notches 50a (FIG 1) in slot 50, which will vary the amount of tension applied to the arm 34. A handle 52 is secured to the end of spring 48 to enable manual adjustment of the spring tension. Thus, generally, a ball 22 will be launched as the catapult arm rotates from a cocked position (shown in FIG.5 and described hereinafter) to a launched position, as shown in FIGS. 2, 3 and 4.
The basket 42 is secured to the catapult arm 34 at approximately a 45° angle relative to the plane of rotation of the catapult arm and, in addition, is canted so that its open side faces generally forwardly when in the launching position shown in FIG. 2. An upper rear edge 56 of the basket 42, extending at an angle to said plane, is the principal engaging portion of the basket on the football 22 as the arm rotates under the force of the spring 48. The football simultaneously is moving out of the basket 42 under centrifugal force as the edge 56 continuously pushes on the football. Thus, this trailing edge 56 is the only substantial engaging area between the ball 22 and the basket 42 as the catapult arm 34 rotates toward its launched position. The effect of the trailing edge 56 contacting the ball 22 as it rotates from its cocked to its launched position is to impart a spiral turn to the football 22 about its longitudinal axis as it leaves the basket 42 with the ball pointed generally in a forward direction. A band 58 secured to the housing 12 abruptly stops the rotation of the catapult arm at the launched position as the catapult arm 34 approaches a vertical orientation as the football is launched through the opening 21 into a trajectory with a spiral motion.
A cocking mechanism, generally designated 60 (FIG. 2), is provided in order to rotate the catapult arm 34 to its cocked position (FIG. 6). More particularly, referring to FIGS. 2, 4 and 6, the cocking mechanism 60 includes a crankshaft 64 which is pivotally mounted in the housing side walls 14. The crankshaft 64 includes an offset lever portion 66 approximately midway between the side walls 14 such that the lever portion 66 will contact the catapult arm 34 eccentric of the crankshaft 64. A crank 68 is secured to the right end of the crankshaft 64 as seen in FIG. 2. A spherical handle 70 is provided on the end of the crank for ease in hand rotation of the crank. The crank 68 is rotated in the direction of arrow A (FIG. 1) to cock the catapult arm 34 as the lever portion 66 of the crankshaft 64 contacts the catapult arm 34 and rotates the catapult arm 34 in the same direction against the force of the spring 48.
The interlocking mechanism 30 (FIGS. 3, 4 and 6) is used to hold the catapult arm 34 in its cocked position until the governor 28 releases it. More particularly, the interlocking mechanism 30 includes a notched ear 84 secured to the basket 42. The interlocking mechanism 30 also includes release lever, generally designated 86, which is pivotally supported on a shaft 88 mounted between the side walls 14. The release lever 86 comprises an upwardly directed portion 90 and a downwardly directed portion 92 (FIG. 5) both of which are secured to a bearing section 94 mounted on the shaft 88. A ball contact member 98 is pivotally secured to the upper end of member 90 by means of a pin 100. The ball contact element 98 includes a tab 102 (FIG. 5) which contacts the back of member 90 and a pin 104 which contacts a notched portion 105 of member 90. This contact of the pins 102 and 104 against the upper element 90, limit the arc of rotation of the ball contact element 98. A coil spring 106 (FIG. 5) is secured at one end 106a to the housing 12 and is secured at the other end106b to a pin 108 on the contact element 98 and biases the ball contact element 98 in a counterclockwise direction as seen in FIG. 6. As the crank arm 68 is rotated in the direction of arrow A to cock the launching mechanism, the football 22 contacts the ball contact element 98 and rotates that element in a clockwise direction as shown by arrow B (FIGS. 3 and 6). The stop tab 102 then will contact the back of the upper element 90, which prevents rotation of the contact element 98 relative to the member 90, and then causes the release lever 86 to rotate in a clockwise direction as shown by arrow C (FIGS. 3 and 6). With continued rotation of the catapult arm 34, the contact element 98 will engage in the ear 84 and hold the catapult arm 34 in its cocked position.
The governor 28 operates to delay the time period in which the catapult arm is released. The governor 28 actually provides time delay means which includes a vertical mounting plate 110 secured to the right wall 14 of the housing by means of screws 112. The vertical plate 110 is spaced from and inside of the right wall 14 by sleeves 114. The plate 110 includes clearance holes 116 and 118 for the crankshaft 64 and the catapult arm support shaft 36. The governor 28 generally includes three gears which are mounted on the plate 110. A release gear 120 (FIGS. 4 and 6) formed in the shape of approximately a 90° segment of a circular gear is secured to the crankshaft 64. When the launching device is in its cocked position, the release gear 120 is in meshing engagement with a pinion gear 122. The pinion gear 122 is secured to a larger gear 124 which is mounted on a shaft 126 between the vertical plate 110 and the right wall 14, as seen in FIG. 2. The larger gear 124 is in meshing engagement with another pinion gear 128 which is rotatably mounted between the vertical plate 110 and the wall 14. The pinion gear is secured to a spoked air friction governor means 130. Of course, other types of flywheel governors are contemplated. After the catapult arm is cocked, a spring 134 (FIG. 2) which is coiled around the crankshaft 64 and secured to the lever portion 66 causes the crankshaft to rotate in a counterclockwise direction (arrow D) as seen in FIGS. 6 and 4. This rotation causes conjoint rotation of the release gear 120. The flywheel 130 which is connected through gears 124 and 122 to the release gear 120, impedes and slows the rotation of the crankshaft 64. This impeding mechanism allows the user of the device to move away from the launching device into position to receive a launched ball 22. A connecting rod 140 connects the release gear 120 with the interlocking mechanism 30. The connecting rod 140 is pivotally connected to the release gear 120 and engages the release lever 86 by an arcuate slot 142. The arcuate slot 142 provides lost motion and allows the release gear 120 to rotate counterclockwise in the direction of arrow E (FIG. 6) from its position as shown in FIG. 6 to its position as shown in FIG. 4 without releasing the interlocking mechanism. At an instant before the release gear 120 reaches its position as shown in FIG. 4, the connecting rod 140 causes the release lever 86 to rotate in a clockwise direction (FIG. 6, arrow C) and causes the contact element 98 to slip off the ear 84 and release the catapult arm. The catapult arm 34 then rotates in the direction of arrow F (FIG. 6) under the force of spring 48 until it contacts the stop band 58. When the catapult arm 34 contacts the stop band 58, the ball 22 is launched through the opening 21. It should be noted that at the time the catapult arm 34 is released by the interlocking mechanism 30, the crankshaft 64 and the lever portion 66 are in a position as shown in FIG. 4 and thus the lever portion 66 does not contact the catapult arm 34. Thus, the governor 28 slowly rotates the crankshaft 64 out of an interference path with the catapult arm 34 and then finally releases the catapult arm for launching of the ball 22. The amount of time which the governor delays the release is predetermined by the characteristics of the spring 134 and the size of the flywheel 130.
The launching device 10 also is provided with a door 150 which closes the opening 21 when the device is in its cocked position as shown in FIG. 6. The door 150 is pivotally mounted within the opening 21 by means of a pin 152 mounted in the side walls 14. The door 150 includes a tab 154 which is provided with an arcuate slot 156 and an offset notch 157 at the back lowermost end of the slot 156. A connecting rod 158 engages at one end in the arcuate slot 156 normally at notch 157 and is pivotally secured to the catapult arm 34 on its other end. The door 150 normally is in an open position when the device 10 is in its launched position (FIG. 3) so that a football 22 may be loaded into the basket 42. As the crank arm 68 is rotated in the direction of arrow A (FIG. 1) the connecting rod 158 will engage the bottom of the slot 156 adjacent the notch 157 and cause the door 150 to close. Two stop tabs 160, one on either side of the opening 21, position the door 150 in a vertical closed position as shown in FIG. 6. As the catapult arm 34 rotates back in the direction of arrow D (FIG. 6) to launch the football 22, the door 150 will be moved open by engagement of the rod 158 in the notch 157 to allow the football 22 to be launched through the opening 21. The slot 156 is provided to permit closing of the door 150 during storage or shipment of the launching device 10 when the catapult arm is in its launched position (FIG. 4). To close the door 150, the connecting rod 158 must be moved out of engagement with the notch 157 to allow the end of the connecting rod 158 to move toward the front uppermost end of the slot 156. A tab or handle 162 is provided on the front of the door 150 to facilitate opening of the door for loading of a football 22 after the door 150 has been closed for storage, etc. When the door is opened, the rod snaps back into notch 157 for operational purposes.
At this time, it is appropriate that the features of the interlocking mechanism and the governor be pointed out. As previously described, an object which is smaller than a football, such as a baseball or large rock, will not be supported in the basket 42 because the openings 46 allow it to fall through the basket. In addition, any object which is not the size and shape of football, will not contact the ball contact element 98 and properly cause the interlocking mechanism to hold the catapult arm 34 in its cocked position. In this event, the catapult arm 34 will immediately start to rotate upwardly in the direction of arrow F (FIG. 6) but its speed of rotation will be slowed by the action of the crank lever portion 66 in contact with the catapult arm 34 and the force of the flywheel 130, such that any object of this nature will not be launched, because of the slow speed of rotation of the catapult arm 34. It should also be pointed out that any large heavy object which is the size and shape of a football, and causes the interlocking mechanism to hold the catapult arm 34 in its cocked position, will not be launched because of the inability of the spring 48 to rotate the catapult arm 34 upwardly.
The spring tension of the spring 48 on the catapult arm 34 is a critical feature of the invention 10. The amount of tension applied to the catapult arm 34 by the spring 48 must be proportional to the size and shape of the football 22 so that the football 22 will roll out of the basket 42 under centrifugal force and yet not roll completely off the trailing edge 56 before the catapult arm reaches its launched position. With proper design of the spring element 48 of the device 10, the invention can be made to launch any size football such as a small toy football or a regulation size football.
The foregoing detailed description has been given for clearness of understanding only and no unnecessary limitations should be understood therefrom, as some alterations will be obvious to those skilled in the art.
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A launching device for propelling a football into an airborne trajectory with the football pointed forwardly and rotating about its longitudinal axis similar to a forward pass in the game of football. The launching device includes a spring-biased, retractable catapult arm with a ball-holding basket on the end thereof. The device is provided with a governor which delays the launching of the ball for a predetermined time period to allow the user to move into position for receiving the ball. The launching device includes height adjustments and spring tension adjustments for regulating the trajectory of the football. A safety interlocking mechanism is provided to prevent the launching of foreign objects. The device cannot be operated unless a football is loaded in the basket. The basket has a size, shape, orientation and edge portion which accurately simulates the trajectory of a thrown football by imparting a spiral spin to the football.
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BACKGROUND
This invention relates to the art of ink jet cartridges and, more particularly, to preparing a used ink jet cartridge for renovation to promote the extended life and reuse thereof.
It is known that the life of an ink jet cartridge can be extended beyond the time it takes to deplete the cartridge of its initial supply of ink. For example, refill kits are provided for replenishing a cartridge's ink supply, and continuous refill systems have been developed for providing a continuous flow of ink to a cartridge from a remotely located ink supply bag or the like. In connection with extending the life of a cartridge, the latter needs to be periodically cleaned or renovated to avoid the buildup of dried ink inside the cartridge and in areas such as the nozzle plate where the buildup can preclude or seriously impair quality printing. The renovating or cleaning process includes soaking the cartridge in a cleaning solution and then flushing the cartridge to force the cleaning fluid through the nozzles or jets in the nozzle plate. Further, a vacuum is pulled across the nozzle jets in the nozzle plate and the internal pressure and/or the vacuum create a force on the nozzle plate tending to lift it from the snout portion of the cartridge to which it is initially bonded during the manufacture of the cartridge. Still further, a centrifuge process is used to remove the cleaning fluid inside the cartridge by expulsion thereof through the nozzle jets, and this centrifugal force will also lift the nozzle plate from its attachment to the cartridge. If the cartridge is then refilled with ink and placed back into service, the loose nozzle plate can result in poor print quality, such as fuzzy print, and can result in cross-contamination of colors in a color printing cartridge. Furthermore, if a cartridge being renovated already has a loose nozzle plate, the renovating or remanufacturing process tends to further loosen or remove the plate. In any event, loose nozzle plates cause a considerable loss in the yield of reusable cartridges in connection with a renovating or remanufacturing process.
SUMMARY OF THE INVENTION
In accordance with the present invention, the attachment of a nozzle plate to an ink jet cartridge is reinforced prior to the renovating or remanufacturing process so as to reduce the occurrence of the plate being loose following the renovation process. More particularly in this respect, the nozzle plate of a cartridge which is adhesively bonded to the snout portion of a cartridge at the time of manufacture is provided with a supplemental bead or beads of an adhesive material to reinforce the attachment of the nozzle plate to the cartridge against loosening of the plate during renovation. The supplemental beads of adhesive material are applied in areas of the nozzle plate other than those in which the initial beads of adhesive are located. While the supplemental beads of adhesive can be applied by hand, it is preferred, in accordance with another aspect of the invention, to apply the adhesive through the use of programmable apparatus in that the latter provides optimal control of bead location and height as well as consistency with respect to these parameters which, in turn, promotes improved process efficiency and minimal material waste. Moreover, the supplemental beads of adhesive promote a higher yield of reusable cartridges at a reduced production cost.
It is accordingly an outstanding object of the present invention to provide an ink jet cartridge in which the attachment of the nozzle plate to the cartridge is reinforced prior to renovation or remanufacturing of the cartridge for continued use.
Another object is the provision of a method of reinforcing the original attachment of a nozzle plate to an ink jet cartridge by supplemental beads of an adhesive material.
Yet another object is the provision of apparatus for applying supplemental beads of an adhesive material to the nozzle plate of a used ink jet cartridge to provide consistency with respect to glue bead location and height.
Still another object is the provision of a method and apparatus for preparing a used ink jet cartridge for remanufacturing which provides improved efficiency with respect to the preparation, minimal material waste, reduced production costs and increased yield of reusable cartridges.
BRIEF DESCRIPTION OF THE DRAWINGS
The foregoing objects, and others, will in part be obvious and in part pointed out more fully hereinafter in conjunction with the written description of preferred embodiments of the invention illustrated in the accompanying drawings in which:
FIG. 1 is a perspective view of an ink jet cartridge to be prepared for renovation in accordance with the present invention;
FIG. 2 is a plan view of the nozzle plate of the cartridge showing one embodiment of reinforcing adhesive beads in accordance with the invention;
FIG. 3 is a cross-sectional elevation view taken along line 3 - 3 in FIG. 2 ;
FIG. 4 is a plan view of the nozzle plate showing another embodiment of reinforcing adhesive bead placement in accordance with the invention;
FIG. 5 is a cross-sectional elevation view taken along line 5 - 5 in FIG. 4 ;
FIG. 6 is a plan view of the nozzle plate showing yet another embodiment of reinforcing adhesive bead application in accordance with the invention;
FIG. 7 is a cross-sectional elevation view taken along line 7 - 7 in FIG. 6 ;
FIG. 8 is a plan view of the nozzle plate showing still another embodiment of reinforcing bead placement in accordance with the invention;
FIG. 9 is a cross-sectional elevation view taken along line 9 - 9 in FIG. 8 ;
FIG. 10 is a perspective view of apparatus for applying beads of adhesive material to a cartridge in accordance with the invention;
FIG. 11 is an enlarged view of a portion of the adhesive dispensing needle for the apparatus;
FIG. 12 is a view of the outlet end of the needle taken along line 12 - 12 in FIG. 11 ;
FIG. 13 is a perspective view of the apparatus showing a cartridge mounted thereon for receiving beads of glue; and,
FIG. 14 is a perspective view of apparatus supporting a plurality of cartridges to receive the glue in accordance with the invention.
DESCRIPTION OF PREFERRED EMBODIMENTS
Referring now in greater detail to the drawings, wherein the showings are for the purpose of illustrating preferred embodiments of the invention only and not for the purpose of limiting the invention, FIG. 1 illustrates an ink jet cartridge 10 having a front wall 12 , a rear wall 14 , a top wall 16 , a bottom wall 18 , and opposite side walls 20 and 22 , all of which cooperatively define a snout region 24 at the lower front end of the cartridge. Snout 24 is provided in a well-known manner with a print head portion of the cartridge including a nozzle plate 26 .
As best seen in FIGS. 2 and 3 , nozzle plate 26 has opposed pairs of side edges 28 and 30 and is received in a recess 32 in snout portion 24 and, in connection with the initial manufacturing of the cartridge, is secured in the recess by beads 34 of adhesive material extending along and overlying edges 28 of the plate. In the embodiments illustrated herein, the nozzle plate is that of a Hewllet-Packard cartridge HP1823 which includes pairs of rows 36 , 38 and 40 of nozzles N extending in the direction between side edges 28 of the nozzle plate and spaced apart from one another in the direction between side edges 30 of the plate. The nozzle plate further includes two pairs of rows 42 of slot S one of which is between and parallel to rows 36 and 38 of the nozzles and the other of which is between and parallel to rows 38 and 40 of the nozzles. In each of the rows 42 , slots S are offset relative to one another in the direction between side edges 28 of the nozzle plate, and the rows of slots overlie a substrate 44 of the print head.
While the invention is illustrated in connection with the cartridge HP 1823 it is applicable to other cartridges including, by way of example only, Hewllet-Packard cartridges HP 6626, HP 6578 and HP 1649A.
In accordance with one aspect of the present invention, prior to the renovating process the nozzle plate is wiped with a suitable cleaning solution to remove any dried ink therefrom, and reinforcing beads 46 of adhesive material are applied along side edges 32 of the nozzle plate. Beads 46 have a width w and a thickness t, and the beads are applied to have an overlap o inwardly of the corresponding side edge 30 of the nozzle plate. In the embodiment illustrated in FIGS. 4 and 5 of the drawing, two reinforcing beads 46 of the adhesive material are applied along each of the side edges 30 . The adhesive material of beads 46 penetrates downwardly between side edges 30 of the nozzle plate and the corresponding edge of recess 32 .
In the embodiment illustrated in FIGS. 6 and 7 of the drawing, a bead 48 of adhesive material is applied over and along each of the rows 42 of slots S and which beads, as set forth more fully hereinafter, penetrate slots S so as to adhere to silicon chip substrate 44 beneath the nozzle plate. As with beads 46 described hereinabove, each of the beads 48 has a width w and a thickness t. In the embodiment illustrated in FIGS. 8 and 9 , two reinforcing beads 48 of adhesive material are applied over each of the rows of slots.
In the embodiments disclosed herein, a preferred adhesive material for the reinforcing beads is available from Henkel Technologies under the latter's product designation Loctite 3321. The latter adhesive is a UV cured acryoated urethane. With respect to beads 46 , the adhesive preferably has a viscosity of from 500 to 6,000 cP, and with respect to beads 48 , the adhesive preferably has a viscosity of from 1 to 150 cP. With respect to adhesive beads 46 , width w is 1.400 mm, thickness t is 0.250 mm, and overlap o is 0.250 mm. With regard to adhesive beads 48 , width w is 0.900 mm, and thickness t is 0.250 mm.
Preferably, with regard to the beads of adhesive applied along side edges 30 and over slots S of the nozzle plate, the glue is deposited at a pressure of between 12 and 15 psi. This pressure promotes dispensing of the glue into the area between the recess and plate edge and downwardly through the slots so as to adhere to the silicon chip therebelow.
While it is possible to manually apply the adhesive in the patterns described hereinabove, it is preferred to apply the glue through the use of robotic apparatus which is programmable to deposit the various patterns at the desired pressure and with the preferred dimensions. In particular in this respect, the use of such apparatus provides accuracy with respect to bead location and height and consistency of deposit from one cartridge to the next. Accordingly, process efficiency is realized with minimal material waste and product costs are advantageously reduced.
Robotic glue dispensing apparatus for the foregoing purpose is illustrated in FIGS. 10 , 13 and 14 of the drawing and is available from Henkel Technologies under the latter's product designation 98279. Loctite 203 . Bench Top Robot. Briefly, the apparatus includes a base 50 and a track post 52 extending upwardly therefrom and supporting a horizontally extending track member 54 . Track member 54 supports a carriage 56 for a glue dispensing nozzle assembly 58 which includes a glue dispensing nozzle or needle 60 . Carriage 56 is displaceable horizontally along track 54 and in opposite directions as indicated by arrow 62 , and nozzle assembly 58 is displaceable vertically relative to carriage 56 and in opposite directions as indicated by arrow 64 . Base 50 is provided with a workpiece support table 66 which is displaceable horizontally in opposite directions as indicated by arrow 68 and which direction is perpendicular to that represented by arrow 62 . Base 50 is provided with an on/off switch 70 by which programmed operation of the apparatus is initiated, and a kill switch 72 enables stopping the operation should it become necessary or desirable to do so.
In accordance with another aspect of the present invention, table 66 is provided with a cartridge clamping assembly 74 which, as shown in FIG. 13 , is operable to mount a cartridge 10 on the table for displacement therewith and with nozzle plate 26 facing upwardly. In this respect, clamping assembly 74 includes a plate 76 against which side 22 of the cartridges engage, and a plate 78 at right angles to plate 76 for engaging front wall 12 of the cartridge. Plates 76 and 78 provide a corner into which the cartridge is pressed by an angularly-oriented spring-loaded clamping member 80 having a V-shaped nose portion, not designated numerically, for engaging the corner between rear wall 14 and side wall 20 of the cartridge so as to bias the cartridge into the corner between plates 76 and 78 . Preferably, the clamping assembly further includes a spring-loaded, toggle-type clamping member 82 having a resilient nose portion 84 for engaging side wall 20 of the cartridge. This clamping member is perpendicular to plate 76 and biases the cartridge thereagainst. As will be appreciated from the foregoing description, a cartridge 10 is firmly clamped in place on table plate 66 and on/off switch 70 is actuated to initiate displacements of table 66 , carriage 56 and nozzle assembly 58 for the application of beads of adhesive to the nozzle plate of the cartridge in accordance with the programmed glue pattern. When the program is completed, the apparatus turns off and the cartridge is removed therefrom.
In accordance with yet another aspect of the invention, as shown in FIGS. 11 and 12 of the drawing, the glue dispensing nozzle or needle 60 includes a circular stem portion 86 having a vertical axis 88 when mounted in the glue dispensing assembly and a terminal end 90 at an angle x to horizontal. The terminal end is provided with an outlet opening 92 which is in a horizontal plane and, accordingly, has an oval contour. Preferably, angle x is 45°. During the depositing of glue, the needle moves relative to a nozzle plate in the direction of arrow 94 , and the oval or ellipsoidal contour of the needle allows the continuous flow of glue so as to maintain a straight line edge of a glue bead onto the nozzle plate. The oval contour also enables the bead of adhesive to be drawn along the surface to which it is applied rather than being plowed along the surface as would be the case if the outlet opening was at an angle to the nozzle plate as opposed to being parallel thereto. Still further, the needle tip contour promotes accuracy with respect to the glue bead overlap of the side edge of the nozzle plate as well as accuracy with respect to maintaining the desired width and thickness of the adhesive feed.
FIG. 14 illustrates a modification of the workpiece support plate 66 of the apparatus for the latter to accommodate a plurality of cartridge clamping assemblies 74 as described hereinabove in connection with FIGS. 10 and 13 . It will be appreciated of course that the apparatus in this instance is programmed to apply a preselected adhesive bead pattern to each of the plurality of cartridges during a cycle of operation of the apparatus.
While considerable emphasis has been placed herein on preferred embodiments of the invention, it will be appreciated that other embodiments can be made and that many changes can be made in the preferred embodiments without departing from the principles of the invention. Accordingly, it is to be distinctly understood that the foregoing descriptive matter is to be interpreted merely as illustrative of the invention and not as a limitation and that it is intended to include other embodiments and all modifications of the preferred embodiments insofar as they come within the scope of the appended claims or the equivalents thereof.
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An ink jet cartridge comprising a housing having a print head portion including a nozzle plate having opposed pairs of side edges, rows of nozzles and at least one row of slots between said rows of nozzles and which plate is initially attached to the head portion by beads of an adhesive material overlying the edges of one pair of the opposed pairs of side edges is prepared for renovation by applying a reinforcing bead of an adhesive material to overlie at least one of the other pair of the opposed pairs of side edges and the at least one row of slots. The beads may be a single bead or segmented and are applied by robotic glue applying apparatus.
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[0001] This application claims the priority of Japanese application nos. JP 2004-006198, filed Jan. 14, 2004, and JP 2004-215095 filed Jul. 23, 2004, the disclosures of which are expressly incorporated by reference herein. This is a divisional application from U.S. application Ser. No. 11/033,953, filed Jan. 13, 2005.
BACKGROUND OF THE INVENTION
[0002] 1. Field of the Invention
[0003] The present invention relates to a nuclear power plant and an operation method thereof, and particularly, to augmenting a power generation capacity.
[0004] 2. Description of the Related Art
[0005] In a conventional newly-constructed nuclear power plant, a power output is augmented by, for example, improving either a composition or a shape configuration of a fuel assembly, or the like, and by increasing a main steam flow rate at an outlet of a reactor.
[0006] A technology of such a conventional example is disclosed in Japanese Patent Laid-Open Publication Hei. 9-264983.
[0007] When applying the conventional technology described above to an existing nuclear power plant, the main steam flow rate increases substantially proportional to an increase of the power output. In order to suppress an increase of the main steam flow rate, a feedwater temperature may be lowered; however, if an extraction steam for heating the feedwater is simply decreased, thermal efficiency is extensively deteriorated and the power output hardly increases. This is not realistic option. Further, the increase of the main steam flow rate decreases a design margin of pressure vessel internals such as feedwater piping, a feedwater heater, a feedwater pump, and a steam dryer, and almost all power plant components, such as a main steam pipe, a high pressure turbine, a low pressure turbine, and a condenser. In a power plant using a normal boiling water reactor, the high pressure turbine is one of the components most likely to be the first to lose its design margin due to the increase of the main steam flow rate. Also in a nuclear power plant system other than a boiling water reactor, there is a similar problem with respect to a plant having a comparatively small design margin of the high pressure turbine, such that when applying a conventional technology to augment power output to an existing nuclear power plant, large scale improvement and change of the plant instruments is required.
[0008] Consequently, there is a need for a nuclear power plant and operation method thereof that enable a power uprate of the plant without extensively changing a configuration of the plant, including its instruments.
SUMMARY OF THE INVENTION
[0009] A first embodiment of the invention to solve the above problem is, after an operation cycle (i.e., a period from an activation of a nuclear power plant to an operation stop thereof for changing fuel), to augment a second reactor thermal power output in a second operation cycle to a level larger than a first reactor thermal power output in the previous operation cycle by decreasing a ratio of extraction steam which is led to a feedwater heater from a steam loop in the second operation cycle.
[0010] A second embodiment of the invention to solve the above problem is, after an operation cycle, to augment a second reactor thermal power output in a second operation cycle to a level larger than a first reactor thermal power output in a previous operation cycle by decreasing a ratio of extraction steam which is led to a feedwater heater specifically from a middle area and an outlet of a high pressure turbine (the outlet steam extraction actually may be taken anywhere between the outlet of the high pressure turbine to any one of the inlets of a moisture separator, a moisture separator and heater, and a moisture separator and reheater).
[0011] In addition, a third embodiment of the invention to solve the above problem is to augment a second reactor thermal power output in a second operation cycle of a reactor to a level larger than a first reactor thermal power output in a previous operation cycle by decreasing a mass flow rate of extraction steam led to a feedwater heater specifically from a middle area and outlet of a high pressure turbine out of extraction steam.
[0012] In addition, a fourth embodiment of the invention to solve the above problem is to augment a second reactor thermal power output in a second operation cycle of a reactor to a level larger than a first reactor thermal power output in a previous operation cycle by decreasing a temperature rise amount at a high pressure feedwater heater placed downstream of a main feedwater pump.
[0013] In addition, a fifth embodiment of the invention to solve the above problem is to augment a second reactor thermal power output in a second operation cycle of a reactor to a level larger than a first reactor thermal power output in a first operation cycle by stopping at least not less than one loop of an extraction steam pipe specifically from a middle area and outlet of a high pressure turbine.
BRIEF DESCRIPTION OF THE DRAWINGS
[0014] FIG. 1 is a schematic drawing of a heat balance of a boiling water reactor plant of an embodiment of the present invention.
[0015] FIG. 2 is a schematic drawing of a heat balance of the boiling water reactor plant of FIG. 1 before a power uprate.
[0016] FIG. 3 is a schematic drawing of a heat balance of the boiling water reactor plant of FIG. 1 with application of a conventional power uprate method.
[0017] FIG. 4 is a schematic drawing of a heat balance of the boiling water reactor plant showing bypassing of a feedwater heater of an embodiment of the present invention.
[0018] FIG. 5 is a schematic drawing of relationships between an operation cycle and a reactor thermal power output, a main steam flow rate, and an extraction steam flow rate.
[0019] FIG. 6 is a schematic drawing of relationships between an operation cycle and a reactor thermal power output, a main steam flow rate, and an extraction steam flow rate.
[0020] FIG. 7 is a schematic drawing of a heat balance of a pressurized water reactor plant of an embodiment of the present invention.
[0021] FIG. 8 is a schematic drawing of a heat balance of the pressurized water reactor plant of FIG. 7 before a power uprate.
[0022] FIG. 9 is a schematic drawing of a heat balance of the pressurized water reactor plant of FIG. 7 with application of a conventional power uprate method.
[0023] FIG. 10 is a schematic drawing of a heat balance of the pressurized water reactor plant showing bypassing of a feedwater heater of an embodiment of the present invention.
DESCRIPTION OF THE PREFERRED EMBODIMENTS
[0024] Here will be described an embodiment where the present invention is applied to the boiling water reactor of one of direct-cycle nuclear power plants.
[0025] FIG. 1 shows a heat balance example of a boiling water reactor (BWR) after a power uprate according to the present invention, and FIG. 2 shows a heat balance example of the boiling water reactor before a power uprate. FIG. 3 shows a heat balance example of the boiling water reactor after a conventional power uprate. FIG. 4 shows an example for realizing a heat balance of the present invention shown in FIG. 1 . Although in FIG. 1 an extraction steam amount is reduced by placing a valve at a middle area of an extraction pipe, the approach shown in FIG. 4 is applied when there is no space at the middle area of the extraction pipe and placement cost of the valve is high. In addition, each of FIGS. 5 and 6 show a conceptual drawing of an operation cycle of an embodiment of the present invention. In FIGS. 1 , 2 , and 3 reactor thermal power output is represented as Q, each mass flow rate of water and steam as G, and each enthalpy of water and steam as H. The reactor thermal power output Q and a mass flow rate G are expressed as ratios (%) based on their respective values at the reactor thermal power output of a reactor and a steam flow rate at an outlet of a reactor pressure vessel before a power uprate as shown in FIG. 2 , and enthalpy is expressed in units of kJ/kg. In addition, each embodiment of the present invention shows a normal operation condition; operation conditions of an activation, stop time, transient state, and furthermore accident are excluded.
[0026] This embodiment of the present invention is shown in FIG. 1 , and the conceptual drawing of the operation cycles for complementing the embodiment is shown in FIG. 5 . FIG. 1 is a drawing schematically showing the heat balance example in a case of performing the power uprate in a boiling water reactor that comprises a recirculation pump and a jet pump within a reactor pressure vessel 1 , and has a main steam pipe 2 , a high pressure turbine 3 and low pressure turbine 5 connected to the main steam pipe, a moisture separator 4 between the high pressure turbine and the low pressure turbine and a condenser 6 receiving steam from low pressure turbine 5 . FIG. 5 contrasts relationships between an operation cycle and a reactor thermal power output, a main steam flow rate (steam flow amount flowing in the main steam pipe from the reactor pressure vessel), and an extraction steam amount together with a conventional power uprate method. One operation cycle is defined as a period from an activation out of a stop condition of a reactor operation to a stop thereof for a fuel change.
[0027] In FIG. 5 , an Nth operation cycle is shown before a power uprate method of the present invention is applied, and at this time the reactor thermal power output is Q=100%. A heat balance example before the power uprate is shown in FIG. 2 . An (N+1)th operation cycle increases the reactor thermal power output by 5% and thereby makes Q=105%. An increase of the reactor thermal power output can be realized by any method, such as by: enlarging a pull-out amount of control rods in the (N+1)th cycle larger than in the Nth cycle; increasing a reactor core flow rate in the (N+1)th cycle larger than in the Nth cycle by increasing a rotation speed of the recirculation pump; and changing a kind of a fuel assembly. In addition, because applying the present invention results in lowering a temperature of feedwater supplied to the reactor pressure vessel, it can also be expected that the reactor thermal power output will naturally rise by coolant density feedback for core reactivity due to a lowering of the reactor-core-inlet coolant temperature.
[0028] In some plants an extraction steam flow rate and main steam flow rate in one cycle are changed as shown in FIG. 6 . In a case of a plant adopting the operation cycle as shown in FIG. 6 , it is assumed that the heat balance, extraction steam flow rate, main steam flow rate, feedwater heating amount, and the like are compared at an operation point where the main steam flow rate becomes maximum in the operation cycle excluding transients, such as activation, stop, accident/transient phenomenon occurrence time, and test operation.
[0029] When increasing the reactor thermal power output, it is necessary to increase a feedwater flow rate or to widen an enthalpy difference of a coolant between an inlet/outlet of the reactor pressure vessel in order to remove the additional increment of thermal energy from the reactor. The conventional power uprate method adopts the former method, increasing the feedwater flow rate in proportion to the reactor thermal power output. A heat balance example by the conventional power uprate method is shown in FIG. 3 . As a result, in the conventional power uprate method the main steam flow rate of the (N+1)th operation cycle shown in FIG. 5 becomes 105%. The present invention adopts the latter method and is characterized by widening the enthalpy difference of the coolant between the inlet/outlet of the reactor pressure vessel by intentionally lowering a feedwater enthalpy at the inlet of the reactor pressure vessel. In order to lower the feedwater enthalpy at the inlet of the reactor pressure vessel, it is possible to decrease an extraction steam from a steam loop and thereby decrease a steam amount sent to feedwater heaters 7 , 9 . However, if only an extraction steam amount is decreased, thermal efficiency decreases and the total power generation increase is limited. Accordingly, by selectively decreasing an extraction steam amount from any of a middle area and outlet of the high pressure turbine (actually at any location from the outlet of the high pressure turbine and an inlet of the moisture separator), a steam amount flowing in the low pressure turbine is increased and thus the power generation amount is increased. Because most extraction steam from the middle area and outlet of the high pressure turbine is used at a feedwater heater downstream of a main feedwater pump 8 , the power uprate method of the present invention may be viewed as a method of decreasing feedwater heating downstream of the main feedwater pump. In a case of a plant where an original extraction steam amount from the middle area and outlet of the high pressure turbine is little, in order to sufficiently decrease a feedwater temperature it may be necessary to also decrease an extraction steam amount extracted from the low pressure turbine in such a plant the extraction steam amount from the middle area and outlet of the high pressure turbine is decreased more, some extent of effect can be obtained. In the embodiment, in spite of increasing the reactor thermal power output by 5% compared to that of the Nth cycle, the main steam flow rate can be made same as that of the Nth cycle. The embodiment shows an ideal power uprate method in which the main steam flow rates of the Nth and (N+1)th operation cycles are assumed to be the same, however, they need not always be entirely the same and may be increased within a range of component design margin, for example, within the design margin of the high pressure turbine.
[0030] When there are a plurality of extraction points at the middle area and outlet of the high pressure turbine, decreasing an extraction steam amount is most effective if the extraction point is selected at the most upstream side of the high pressure turbine. In this case although it is possible to place an extraction pipe flow rate adjustment valve 10 for controlling the extraction steam amount at this location, it is possible to completely close at least one extraction pipe. As a closing method, it is possible to place a shut-off valve in the extraction pipe or to plug the pipe. When an extraction pipe is completely closed, control loop instruments for monitoring the extraction steam amount become unnecessary and operation control is also simplified. Whether controlling the extraction steam amount or completely closing the extraction pipes is preferred depends on the heat balance and the power uprate range, for example, it may be necessary to be able to adjust the steam extraction amount if an extraction steam amount per extraction pipe is high and when the extraction pipes are completely closed, a feedwater temperature lowers too much. In addition, instead of placing a shut-off valve in an extraction pipe, a feedwater flow rate flowing in a feedwater heater may be decreased. This embodiment is shown in FIG. 4 , in which a feedwater heater bypass loop 11 is placed in the feedwater piping, and a part of feedwater is made to flow in the bypass loop 11 . A low temperature coolant flowing in the bypass loop 11 bypasses at least one feedwater heater and then mixes with high temperature main feedwater. Thus a lowering of a feedwater temperature can be realized at an inlet of the reactor pressure vessel.
[0031] Because when augmenting the reactor thermal power output and increasing the power generation amount of a nuclear power plant, the embodiment can suppress an increase of a feedwater flow rate and a main steam flow rate, it can suppress an increase of a load on a feedwater pipe, main steam pipe, and pressure vessel internals. Compared to the case of simply decreasing the extraction steam amount, the present invention can suppress the lowering of the thermal efficiency and obtain a larger power output. In addition, although in an extensive power uprate by a conventional power uprate method it generally becomes necessary to change the high pressure turbine, with the present invention a power uprate range performable without a change of the high pressure turbine widens compared to the conventional method. Further, as the feedwater temperature lowers, a thermal margin (corresponding to an MCPR (Minimum Critical Power Ratio) in a case of the BWR) of a reactor core increases, there is also the benefit of an increase of a design margin compared to the conventional method. Although in a power uprate a pressure loss and stability of the reactor core deteriorates, in the power uprate method of the present invention a void fraction of the reactor core becomes lower and an absolute value of void coefficient of the reactor core becomes larger, and thus the pressure loss of the reactor core is reduced, and the deterioration of the stability of the reactor core is also suppressed. The decrease of the pressure loss of the reactor core means that an increase of a load on the jet pump and recirculation pump for recirculating a coolant by a power uprate can also be suppressed. Because an increase in the amount of generation steam in the reactor core also becomes small compared to the increase of the thermal power output, an increase of carry under that occurs due to a steam entrainment into recirculation water is also small, and even in an extensive power uprate, it becomes easy to ensure a flow window. A direct-cycle nuclear power plant other than the boiling water reactor may also have a power uprate by a similar method.
[0032] Table 1 shows a relationship among a reactor thermal power output, main steam flow rate, extraction steam flow rate, and feedwater enthalpy when applying the power uprate method of the embodiment to various output increase amounts. The reactor thermal power output and the main steam flow rate show ratios in the case of a reactor thermal power output of 100%, and the extraction steam flow rate shows a ratio for the main steam flow rate in the case of the reactor thermal power output of 100%. As seen from Table 1, even when making the reactor thermal power output 110%, the power uprate method of the present invention is widely applicable. A reason why the output is not shown only until 110% in Table 1 is that in a higher power uprate a change of the moisture separator and the like becomes necessary; if the moisture separator is changed or combined with a reactor pressure increase, the power uprate method of the present invention is more extensively applicable.
[0033] Generally in the boiling water reactor a reactor thermal power output may be increased to 102% solely by improving measurement accuracy of a feedwater flowmeter and the like. Therefore, the present invention has greater applicability to a power uprate in ranges above 102%. Furthermore, in the power uprate up to a reactor thermal power output of 105%, it is generally unnecessary to extensively change system plant components, such as a change of the high pressure turbine. Using the present invention, particularly a large effect can be obtained because the change of the high pressure turbine becomes unnecessary even in the power uprate exceeding the reactor thermal power output 105%.
[0000]
TABLE 1
Reactor thermal
Main Steam
Extraction Steam
Feedwater
power output (%)
Flow Rate (%)
Flow Rate (%)
Enthalpy (kJ/kg)
100
100
45
924
103
100
43
869
105
100
42
831
107
100
40
795
110
100
38
739
110
105
42
831
[0034] Next will be shown an embodiment of the present invention applied to a pressurized water reactor (PWR) of an indirect cycle nuclear power plant.
[0035] FIG. 7 shows a heat balance example of the pressurized water reactor of the present embodiment after a power uprate, and FIG. 8 shows a heat balance example of the pressurized water reactor before a power uprate. FIG. 9 shows a heat balance of the pressurized water reactor after applying a conventional power uprate method. Each of FIGS. 5 and 6 shows the conceptual drawing of the operation cycle of one embodiment of the present invention. In FIGS. 7 , 8 , and 9 reactor thermal power output is represented as Q, each mass flow rate of water and steam as G, and each enthalpy of water and steam as H. The reactor thermal power output Q and a mass flow rate G are expressed as ratios (%) based on their respective values at the reactor thermal power output and steam flow rate (steam amount flowing in a secondary main steam pipe from a steam generator) of a reactor before a power uprate as shown in FIG. 8 , and enthalpy is expressed in units of kJ/kg. A heat exchange amount at a steam generator is an amount where a heat leak in a primary loop is subtracted from a reactor thermal power output, and because a normal heat leak amount is sufficiently small compared to the reactor thermal power output, the heat exchange amount at the steam generator and the reactor thermal power output are assumed equal.
[0036] This embodiment of the present invention is shown in FIG. 7 , and the conceptual drawing of the operation cycle for the embodiment is shown in FIG. 5 . FIG. 7 schematically shows a heat balance example in the pressurized water reactor that comprises a reactor pressure vessel 1 , a steam generator 13 transferring heat generated at a reactor core within the reactor pressure vessel to a secondary loop, a main steam pipe 2 leading secondary loop steam going out of the steam generator, a high pressure turbine 3 and low pressure turbine 5 connected to the main steam pipe, a moisture separator and heater 12 between the high pressure turbine and the low pressure turbine, and a condenser 6 receiving steam from low pressure turbine 5 . FIG. 5 contrasts relationships between an operation cycle and a reactor thermal power output, a main steam flow rate, and an extraction steam amount in a case of using the embodiment together with a conventional power uprate method. One operation cycle is defined as a period from a reactor activation to a reactor operation stop for a fuel change.
[0037] In FIG. 5 an Nth operation cycle is shown before an power uprate method of the present invention is applied, and at this time the reactor thermal power output is Q=100%. A heat balance example before the power uprate is shown in FIG. 8 . An (N+1)th operation cycle increases the reactor thermal power output by 5% and thus makes Q=105%. An increase of the reactor thermal power output can be realized by any method, such as by: enlarging a pull-out amount of control rods in the (N+1)th cycle larger than in the Nth cycle; and changing a kind of a fuel assembly.
[0038] In some plants an extraction steam flow rate and main steam flow rate in one cycle are changed as shown in FIG. 6 . In a case of a plant adopting the operation cycle as shown in FIG. 6 , it is assumed that the heat balance, extraction steam flow rate, main steam flow rate, feedwater heating amount, and the like are compared at an operation point where the main steam flow rate becomes maximum in the operation cycle excluding transients, such as activation, stop, accident/transient phenomenon occurrence time, and test operation.
[0039] When increasing the reactor thermal power output, it is necessary to increase a primary coolant flow rate into the reactor pressure vessel and a secondary feedwater flow rate into the steam generator, or to enlarge an enthalpy difference of a primary coolant between an inlet/outlet of the reactor pressure vessel and that of a secondary coolant between an inlet/outlet of the steam generator in order to remove the additional increment of thermal energy from the reactor. The conventional power uprate method adopts the former method, increasing the primary coolant flow rate and the secondary feedwater flow rate in proportion to the reactor thermal power output. A heat balance example by the conventional power uprate method is shown in FIG. 9 . As a result, in the conventional power uprate method the main steam flow rate of the (N+1)th operation cycle shown in FIG. 5 becomes 105%. The present invention adopts the latter method and is characterized by enlarging the enthalpy difference of the secondary coolant between the inlet/outlet of the reactor pressure vessel with intentionally lowering a secondary feedwater enthalpy at the inlet of the steam generator. In order to lower the feedwater enthalpy at the inlet of the reactor pressure vessel, although it is possible to decrease an extraction steam from a steam loop and thereby to decrease a steam amount sent to the feedwater heaters 7 , 9 . However, if only an extraction steam amount is decreased, thermal efficiency decreases and the total power generation increase is limited. Accordingly, by selectively decreasing an extraction steam amount from any of a middle area and outlet of the high pressure turbine (actually at any location from the outlet of the high pressure turbine and an inlet of the moisture separator), a steam amount flowing in the low pressure turbine is increased and thus the power generation amount is increased. Because most extraction steam from the middle area and outlet of the high pressure turbine is used at a feedwater heater downstream of a main feedwater pump 8 , the power uprate method of the present invention may be viewed as a method of decreasing feedwater heating downstream of the main feedwater pump. In a case of a plant where an original extraction steam amount from the middle area and outlet of the high pressure turbine is little, in order to sufficiently decrease a feedwater temperature it may be necessary to also decrease an extraction steam amount extracted from the low pressure turbine. If in such a plant the extraction steam amount from the middle area and outlet of the high pressure turbine is decreased more, some extent of effect can be obtained. In the embodiment, in spite of increasing the reactor thermal power output by 5% compared to that of the Nth cycle, the main steam flow rate can be made same as that of the Nth cycle. The embodiment shows an ideal power uprate method in which the main steam flow rates of the Nth and (N +1)th operation cycles are assumed to be the same, however, they need not always be entirely the same and may be increased within a range of component design margin, for example, within the design margin of the high pressure turbine.
[0040] When there are a plurality of extraction points at the middle area and outlet of the high pressure turbine, decreasing an extraction steam amount is most effective if the extraction point is selected at the most upstream side of the high pressure turbine. In this case although it is possible to place an extraction pipe flow rate adjustment valve 10 for controlling the extraction steam amount at this location, it is possible to completely close at least one extraction pipe. As a closing method, it is possible to place a shut-off valve in the extraction pipe or to plug the pipe. When an extraction pipe is completely closed, control loop instruments for monitoring the extraction steam amount become unnecessary and operation control is also simplified. Whether controlling the extraction steam amount or completely closing the extraction pipes is preferred depends on the heat balance and the power uprate range, for example, it may be necessary to be able to adjust the steam extraction amount if an extraction steam amount per extraction pipe is high and when the extraction pipes are completely closed, a feedwater temperature lowers too much. In addition, instead of placing a shut-off valve in an extraction pipe, a feedwater flow rate flowing in a feedwater heater may be decreased. This embodiment is shown in FIG. 10 , and it shows an example for realizing a heat balance of the present invention shown in FIG. 7 . Although in FIG. 7 an extraction steam amount is reduced by placing a valve at a middle area of an extraction pipe, a method shown in FIG. 10 is applied when there is no space at the middle area of the extraction pipe and placement cost of the valve is high. In this embodiment a feedwater heater bypass loop 11 is placed in the feedwater piping, and a part of feedwater flow is made to flow in the bypass loop 11 . A low temperature coolant flowing in the bypass loop 11 bypasses at least one feedwater heater and then mixes with high temperature main feedwater. Thus a lowering of a feedwater temperature can be realized at an inlet of the reactor pressure vessel.
[0041] Because when augmenting the reactor thermal power output and increasing the power generation amount of a nuclear power plant, the embodiment can suppress an increase of a feedwater flow rate and a main steam flow rate, it can suppress an increase of a load on the feedwater pipe, main steam pipe, and steam generator. It is also possible to lower the reactor pressure vessel inlet temperature of a primary loop without increasing the primary coolant flow rate, and in this case it is more effective to suppress the increase of a load on the steam generator and a load on the primary coolant pump is also reduced. Furthermore, if the reactor pressure vessel inlet temperature of the primary loop lowers, a thermal margin (corresponding to a DNBR (Departure from Nucleate Boiling Ratio) in the case of the PWR) of a reactor core increases, there is also the benefit of an increase of a design margin compared to the conventional method. A indirect-cycle nuclear power plant other than the pressurized water reactor may also have a power uprate by a similar method.
[0042] Thus, although the embodiments of the present invention are described, the invention is not limited thereto, and various variations are available without departing from the spirit and scope of the invention.
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A nuclear power plant and method of operation for augmenting a second reactor thermal power output in a second operation cycle to a level larger than a first reactor thermal power output in the previous operation cycle. The plant is equipped, for example, with a reactor; a steam loop comprising high and low pressure turbines; a condenser for condensing steam discharged therefrom the low pressure turbine; a feedwater heater for heating feedwater supplied from the condenser; and a feedwater loop for leading feedwater discharged from the feedwater heater to the reactor. The operation method includes decreasing a ratio of extraction steam which is led to the feedwater heater from a steam loop in the second operation cycle.
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CROSS-REFERENCE TO RELATED APPLICATIONS
This application is a continuation of U.S. patent application Ser. No. 13/028,060, filed on Feb. 15, 2011, the entire contents of which are hereby incorporated by reference.
FIELD OF INVENTION
The present invention relates to the field of location based services, and more specifically to a system and method for dynamically monitoring status in location services.
BACKGROUND
Radiolocation of mobile devices developed in the last half of the 20 th century, notably with the deployment of the Global Positioning System (GPS). Mobile phone technology evolved in a similar time frame. By the turn of the century, US cellular carriers deployed location-determination technology in their networks in support of emergency (E9-1-1) services. Subsequently, with the widespread use of smart phones and other portable computing devices, numerous applications utilizing location have been made available for such uses as direction finding, tracking individuals, and matching persons with nearby businesses.
Traditionally, a company might monitor its resources, e.g., vehicles, through an expensive specialized tracking system. With location technology being integrated into employees' personal communication equipment (cell phones), the specialized tracking systems may no longer be needed. The employer can track the employees via their cell phones. However, it may be necessary or appropriate for the employer to only track the employee during work hours. A simple “9-to-5, Monday-through-Friday,” tracking limitation is not suitable for many workers who may have flexible hours, employees on vacation, etc.
The present invention solves this problem by enabling and disabling location tracking or reporting thereof, based on a dynamically monitored status, for example, when an employee is on the job and when the employee is on his or her own time.
SUMMARY
In some embodiments, the present invention is a method for reporting a location of an asset. The method includes: receiving a location tracking request for the asset; dynamically determining a status of the asset; and allowing acquisition of the location of the asset based on the determined status. The method further includes: obtaining the location of the asset responsive to the received request and said allowing; and reporting the obtained location of the asset.
In some embodiments, the present invention is a system for reporting a location of an asset. The system includes: a reporting module for receiving a location tracking request for the asset; a status module for dynamically determining a status of the asset; and a tracking module for obtaining the location of the asset responsive to the determined status. The reporting module reports the location of the asset responsive to the received location tracking request.
In some embodiments, the present invention is a method for reporting a location of an asset. The method includes: receiving a first indication of a current state of the person, the current state being one of a plurality of predefined states, wherein the first indication is triggered by a first action of the person; storing information about the current state; determining a first permission based on the information about the current state, the first permission indicating a first level of allowed location reporting; and reporting the location of the person based on the first permission. The method may further include receiving a second indication of an updated current state of the person, the updated current state being one of the plurality of predefined states, wherein the second indication is triggered by a second action of the person; storing information about the updated current state; determining a second permission based on the information about the updated current state, the second permission indicating a second level of allowed location reporting; and reporting the location of the person based on the second permission.
BRIEF DESCRIPTION OF THE DRAWINGS
FIG. 1 shows a system diagram for tracking an employee, according to the prior art.
FIG. 2 shows a form for entering tracking times, according to the prior art.
FIG. 3 shows an exemplary system diagram for tracking an asset, according to some embodiments of the present invention.
FIG. 4 shows an exemplary logical flow of a reporting module, according to some embodiments of the present invention.
DETAILED DESCRIPTION
In some embodiments, the present invention enables and/or disables location tracking of an asset or resource, or reporting thereof, based on a dynamically monitored status, for example, when an employee is on the job and/or when the employee is on his or her own time.
FIG. 1 illustrates an exemplary functional block diagram of a typical employee tracking system, according to the prior art. Data flows are indicated by arrowed lines. An employee 101 is monitored by a tracking module 102 . The dotted line indicates a location determination, e.g., using the cellular network. The tracking module provides employee locations to a reporting module 103 , which in turn make the locations available to an employer 104 . An example of this is a cell phone tracking feature provided by a cellular carrier. In this example, the employer pays for the employee cell phone usage, and in turn has permission to monitor employee location while the employee is working. The details are controlled by a configuration module 105 , which has information entered by the employer and possibly the employee. Configuration typically includes information such as employee name, mobile device identification, times for employee to be tracked, boundary areas for alerts, etc. The employee may or may not have access to aspects of the configuration.
FIG. 2 illustrates an example of a form used to enter some of the configuration information, according to the prior art. For a given account, the tracking can be made active (allowed) or inactive (disallowed) in the first line. In the second line, the hours of tracking are entered, here from 8 AM to 5 PM. In the third line, the days of tracking are entered, here weekdays only. Such a system does not easily account for such eventualities as the employee taking a sick day, or working a Saturday in place of a Friday, or employees with flexible schedules.
FIG. 3 shows an exemplary system diagram for tracking an asset, according to some embodiments of the present invention. The illustrated system may be applied to a more general set of tracked assets, beyond employees. An asset 301 is monitored by a tracking module 302 . The tracking module provides the asset locations to a reporting module 303 . The reporting module 303 reports the locations of the asset, based on conditions set by a user.
The reporting module 303 provides location of the asset or resource 301 to the monitor module 304 , under control of a configuration (module) 305 . The configuration includes information such as asset name, mobile device identification, boundary areas for alerts, etc. The times for asset to be tracked are supplemented or replaced by the combination of the status monitor module 306 and enablement module 307 . The status monitor module, described in more detail below, determines the state of the asset at any given time. Based on the status, the enablement module 307 determines whether tracking is permitted and indicates to the reporting module whether location information may be delivered. Obtaining the location of the asset may depend on the configuration. Reporting the location of the asset may also depend on the enablement module, as well as the configuration.
In some embodiments, the status monitor module keeps track of the asset's status, for example, as a binary state: either “at work”/“on the clock” (allowing the asset to be tracked) or “off work”/“off the clock” (preventing the asset from being tracked). This may be implemented any number of ways. In some embodiments, the invention uses a device based on a traditional time clock, where employees (physically) clock in and clock out when arriving at, and leaving work. For people or assets that do not report to a central location each day, other methods, such as sending a text message or email, making a phone call, or logging in to a web portal may be available.
In some embodiments, the status monitor module has more complex permission states. A third state could indicate a person's or an asset's eligibility for tracking only with a positive response to an explicit request for permission to be located. So, in this case while a user has given permission to be located during a particular period of time, their consent may be granted by the user on a case-by-case basis based on the requestor of the location or their current status during the authorized timeframe, but automatically denied if outside the authorized timeframe.
In some embodiments, other sets of states allow the person or the asset to be tracked with varying degrees of accuracy depending on the location of the asset or the time of the location request. For example the person or the asset may be tracked by exact location while on the clock, tracked by neighborhood on lunch hour, and not tracked at all on the weekend. Also, the varying degrees of tracking accuracy might be determined by privacy concerns or cost, where less exact locations may be less expensive. A long haul delivery vehicle might need only the less expense/less accurate tracking while on the open road, but require more precise tracking near the terminus points.
The following examples show how a variety of trigger events can be used to set tracking status. A tracking status may be assigned to a person or vehicle entering a sensitive area such as a military base; a person or vehicle leaving a known area, such as a school or worksite; an emergency vehicle with its lights/siren engaged; a vehicle traveling at an excessive speed; and/or a container loaded onto a ship, which would not need to be tracked individually until later when it is unloaded from the ship.
The enablement module 307 , which in some embodiments may not be distinct from the status monitor module, indicates the person or asset tracking permission to the reporting module. When not enabled, the reporting module 303 prevents location information from being delivered to the status monitor module, thus protecting the asset's privacy during non-work hours. However, depending on permissions, the reporting module could be configured to provide a person's location to other requestors, as in a family location scenario, regardless of the person's “at work” status.
FIG. 4 shows an exemplary logical flow of a reporting module, according to some embodiments of the present invention. As shown, the reporting module waits for a tracking request to be received 401 , for example, from a status monitor module. When a request is received, the configuration is optionally checked 402 , for example, to verify the status monitor module's credentials, verify the identity of the tracked person or asset, etc. If the configuration verification fails, no location is returned 407 . If the configuration verification is successful, a status enablement check is performed 403 . In this process, the enablement state determined by the status monitor module and enablement module is checked to see if tracking is currently allowed, and any associated constraints (e.g., low precision tracking only). If tracking is not allowed, no location is returned 407 .
If tracking is allowed, then an attempt is made to locate the asset 405 via the tracking module. If the location is not available 405 , no location is returned. If the location is available 405 , the location is returned 406 . The allowance of the tracking may be stored for a next tracking request of the person or the asset.
In some embodiments, a first indication of a current state of the person is received, the current state being one of a plurality of predefined states (e.g., “at work,” “off work”). The first indication is triggered by a first action of the person, such as clocking in to work as described earlier. The information about the current state (“at work” in this example) is then stored. Subsequently, a first permission is determined based on the information about the current state, the first permission indicating a first level of allowed location reporting (e.g., “full tracking allowed”). The location of the person is then reported based on the first permission. Later, a second indication of an updated current state of the person may be received, as when the person clock out of work. The updated current state (“off work”) is also one of the predefined states, and is also triggered by a second action of the person. The information about the updated current state is then stored, and a second permission is determined based on the information about the updated current state, the second permission indicating a second level of allowed location reporting (e.g., “no tracking allowed”). The location of the person is reported again, or in this example, denied, this time, based on the second permission.
It will be recognized by those skilled in the art that various modifications may be made to the illustrated and other embodiments of the invention described above, without departing from the broad inventive scope thereof. It will be understood therefore that the invention is not limited to the particular embodiments or arrangements disclosed, but is rather intended to cover any changes, adaptations or modifications which are within the scope of the invention, as defined by the appended claims.
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A method and system for reporting a location of an asset. The method includes: receiving a location tracking request for the asset; dynamically determining a status of the asset; and allowing acquisition of the location of the asset based on the determined status. The method further includes: obtaining the location of the asset responsive to the received request and said allowing; and reporting the obtained location of the asset. The system includes: a reporting module for receiving a location tracking request for the asset; a status module for dynamically determining a status of the asset; and a tracking module for obtaining the location of the asset responsive to the determined status. The reporting module reports the location of the asset responsive to the received location tracking request.
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RELATED APPLICATION
[0001] The present disclosure relates to subject matter contained in priority Korean Application No. 10-2006-0001085, filed on Jan. 4, 2006, which is herein incorporated by reference in its entirety.
BACKGROUND
[0002] 1. Technical Field
[0003] The present disclosure relates generally to a fin-tube heat exchanger, and, more particularly, to a fin-tube heat exchanger applied for a direct cooling type refrigerator capable of enhancing the efficiency of heat exchange with ambient air.
[0004] 2. Description of the Related Art
[0005] FIG. 1 illustrates a general shape of a cabinet 1 of a refrigerator having a refrigerating chamber 10 and a freezing chamber 20 . In general, in a direct cooling type refrigerator, an evaporator is tightly attached in the refrigerating chamber 10 or the freezing chamber 20 , or a mounting plate is formed as an evaporator to directly cool the refrigerating chamber 10 or the freezing chamber 20 . Recently, an indirect cooling type refrigerator in which cooling air is injected to the refrigerating chamber 10 and the freezing chamber 20 has been commonly used. Compared with the indirect cooling type refrigerator, the direct cooling type refrigerator is operated based on a principle that cooling air of the evaporator is directly supplied to the refrigerating chamber 10 or freezing chamber 20 according to natural convection phenomenon of cooled air around the evaporator, instead of separately generating a large quantity of cooling air.
[0006] FIG. 2 illustrates a side view of the structure of the direct cooling type refrigerator of FIG. 1 . FIG. 3 illustrates a schematic block diagram showing the construction of a refrigerating cycle of the direct cooling type refrigerator of FIG. 2 . As shown in FIGS. 2 and 3 , the direct cooling type refrigerator 9 has a refrigerating cycle in which two evaporators 50 and 60 are connected in series. Namely, the direct cooling type refrigerator 9 includes a cabinet 1 having a refrigerating chamber 10 and a freezing chamber 20 , a compressor 30 for compressing the refrigerant of the refrigerating cycle and generally formed at a lower portion of the cabinet 1 , a condenser 40 for receiving compressed refrigerant in a direction of reference numeral 88 along a refrigerant passage 99 and condensing the refrigerant while emanating heat, a first evaporator 50 tightly attached on a rear surface of the refrigerating chamber 10 and cooling the refrigerating chamber 10 by evaporating the refrigerant from the condenser 40 , a second evaporator 60 tightly attached on a rear surface of the freezing chamber 20 in order to evaporate the refrigerant either from the first evaporator 50 or from the condenser 40 to thus cool the freezing chamber 20 , and a valve 80 for selectively opening a first tube 81 that connects the condenser 40 and the first evaporator 50 and a second tube 82 that connects the condenser 40 and the second evaporator 60 .
[0007] The condenser 40 operates as a heat exchanger to exchange heat generated as the refrigerant is condensed with ambient air. The evaporators 50 and 60 also need to effectively absorb ambient heat as the refrigerant is evaporated.
[0008] FIG. 4 illustrates a perspective view of the structure of a conventional heat exchanger of a direct cooling type refrigerator. FIG. 5 illustrates a side view of the heat exchanger of FIG. 4 . In the heat exchanger as shown in FIGS. 4 and 5 , a plurality of fins 42 for helping heat exchange around the tube 41 through which the refrigerant flows are attached around the tube 41 . The plurality of fins 42 are braze-welded in a state that they point-contact with the tube 41 , as represented by reference numeral 42 a. Heat exchange between the tube 41 and the fins 42 occurs at this contact.
SUMMARY
[0009] In one general aspect, a heat exchanger capable of improving performance of exchanging heat with ambient air and a method of manufacturing such a heat exchanger are provided. Implementations of the heat exchanger may improve freezing and noise prevention performance of a direct cooling type refrigerator by applying the heat exchanger to a condenser or an evaporator of the direct cooling type refrigerator.
[0010] To this end, a heat exchanger may include a tube through which a refrigerant flows, and a fin attached to the tube. The fin may have a nonlinear shape at an interface between the fin and the tube. More particularly, the fin may be shaped to conform with a shape of the tube at the interface between the fin and the tube. The interface between the fin and the tube may define an arc and the fin may have an arcuate shape at the interface. Also, the fin or the tube may have a serpentine shape.
[0011] The tube of the heat exchanger may include multiple parallel portions and the fin may interface with at least two of the parallel portions of the tube and may be shaped to conform with a shape of the tube at the interfaces between the fin and the at least two parallel portions.
[0012] In another general aspect, a heat exchanger may include a tube through which a refrigerant flows, and a plurality of fins attached to the tube. Each of the fins may have a nonlinear shape at an interface between the fin and the tube. More particularly, each of the fins may be shaped to conform with a shape of the tube at the interface between the fin and the tube. Specifically, the interface between the fin and the tube may define an arc, and the fin may have an arcuate shape at the interface.
[0013] The tube of the heat exchanger may include multiple parallel portions and each of the fins may interface with at least two of the parallel portions of the tube and may be shaped to conform with a shape of the tube at the interfaces between each of the fins and the at least two parallel portions.
[0014] Also, a first group of the fins may be attached to an upper surface of the tube and a second group of the fins may be attached to a lower surface of the tube. The fins may be arranged in such a manner that each fin of the first group is placed between two adjacent fins of the second group.
[0015] In yet another general aspect, a refrigerator using heat exchangers as explained above is provided.
[0016] In another general aspect, a method of manufacturing a heat exchanger includes providing a tube through which a refrigerant flows, and attaching a plurality of fins to the tube. Each fin may have a nonlinear shape at an interface between the fin and the tube. More particularly, each fin may be shaped to conform with a shape of the tube at the interface between the fin and the tube. Attaching the fins to the tube may include attaching a first group of fins to an upper surface of the tube and attaching a second group of fins to a lower surface of the tube. Each fin of the first group may be placed between two adjacent fins of the second group.
[0017] In another general aspect, a heat exchanger may include fins formed in a wavy shape, and a tube attached with the wavy fins and bent in a zigzag shape.
[0018] Because the fins for assisting heat exchanging between ambient air and a fluid passing through the tube are formed in the wavy shape and the tube is attached with the wavy surface of the fins and line-contacts or surface-contacts, not point-contacts, the heat transfer area between the fins and tube is increased and the performance of heat exchanging between the tube and the ambient air is highly improved.
[0019] The wavy surfaces of the fins are respectively attached to the upper surface and the lower surface of the tube, so heat of a fluid in the tube can be heat-exchanged with the ambient air through the wavy fins. In this case, the fins attached to the upper surface of the tube and the fins attached to the lower surface of the tube are not positioned on the same planes (namely, they are positioned on different planes), whereby the ambient air of the heat exchanger can be heat-exchanged with fin having a larger sectional area.
[0020] For example, when the heat exchanger works as the condenser so a hot refrigerant flows in the tube and the ambient air has a low temperature compared with that of the heat exchanger, because the fins are arranged in the crisscross manner on different planes of the tube, each fin can contact with cold air which has not been heated by adjacent fins. Namely, when the heat exchanger is positioned horizontally and there is no flow in the ambient air, air heated after being heat exchanged with the fins is naturally move upward by convection without being heat exchanged with the adjacent fins. Accordingly, the fins arranged in the crisscross manner can contact with the ambient cold air and maximize the cooling efficiency.
[0021] The fins surface-attached to the upper surface of the tube and the fins surface-attached to the lower surface of the tube are arranged at uniform gap therebetween, so its mass-production can be improved in terms of fabrication.
[0022] An inner curvature of the wavy fins may be the same as an outer diameter of a section of the tube. Accordingly, because the fins are formed in a wrapping or covering manner, a larger contact area between the tube and the fins can be obtained.
[0023] In addition, both ends of the fins may be attached to the tube in the wrapping manner. Thus, the heat transfer efficiency between the both ends of the tube and fins can be improved and the bonding strength between the fins the tube can be improved.
[0024] Implementations may provide a direct cooling type refrigerator in which the heat exchanger is applied for the condenser and the evaporator.
[0025] Other features will be apparent from the following description, including the accompanying drawings, and the claims.
BRIEF DESCRIPTION OF THE DRAWINGS
[0026] FIG. 1 is a perspective view showing a general shape of a cabinet of a refrigerator;
[0027] FIG. 2 is a side view showing the structure of the direct cooling type refrigerator of FIG. 1 ;
[0028] FIG. 3 is a schematic block diagram showing a refrigerating cycle of the direct cooling type refrigerator of FIG. 2 ;
[0029] FIG. 4 is a perspective view showing the structure of a conventional heat exchanger of the direct cooling type refrigerator of FIG. 1 ;
[0030] FIG. 5 is a side view of the conventional heat exchanger of FIG. 4 ; and
[0031] FIGS. 6 to 8 are views showing the structure of a heat exchanger, in which FIG. 6 is a perspective view showing the structure of the heat exchanger, FIG. 7 is a sectional view taken along line VII-VII of FIG. 6 , and FIG. 8 is a front view of the heat exchanger of FIG. 6 .
DETAILED DESCRIPTION
[0032] FIGS. 6 to 8 illustrate the structure of a heat exchanger. As shown in FIGS. 6 to 8 , a heat exchanger 100 includes a tube 101 that allows a fluid to flow therein, and fins 102 and 103 having a nonlinear shape at an interface between the fins 102 and 103 and the tube 101 . For example, as shown in FIG. 6 , the fins 102 and 103 may be formed in a wavy shape and attached to the top and bottom portions 102 a and 103 a of the tube 101 .
[0033] In general, the fins may be shaped to conform with a shape of the tube at the interface between the fins and the tube. For example, a curvature of the inner surface of the wavy fins 102 and 103 may be substantially the same as the outer diameter of the cross-section of the tube 101 , so the contact areas 102 a and 103 a can be maximized.
[0034] As shown in FIG. 8 , the upper fins 102 attached to the upper portion of the tube 101 and the lower fins 103 attached to the lower portion of the tube 101 are arranged in an interdigital manner on different planes with a certain interval therebetween. Thus, each upper fin is placed between two adjacent lower fins. This arrangement also improves the heat exchange capability of the heat exchanger, particularly when the heat exchanger 100 is placed horizontally, since the interdigital arrangement of fins 102 and 103 of the heat exchanger 100 can increase the chances of heat exchanging with ambient cold air.
[0035] Also, because both ends 102 b and 103 b of the fins 102 and 103 are attached to the tube 101 in a wrapping manner, the heat transfer between the fins 102 and 103 and the tube 101 can be further increased and the bonding strength between the fins 102 and 103 and the tube 101 can be also increased.
[0036] The heat exchanger 100 constructed as described above can be utilized for various purposes. For example, it can be advantageously applied for the condenser of a direct cooling type refrigerator, for the following reasons. Because the cooling mechanism of a direct cooling type refrigerator is buried in an insulation panel of the cabinet of the refrigerator, a blow fan is not provided. So, if the heat exchange with the ambient air of the condenser is not sufficient, a refrigerant pipe with a sufficient length should be obtained to release the heat generated from the condenser 40 . If the tube of the condenser 40 is lengthened, the amount of refrigerant to be filled in the refrigerant pipe of the condenser 40 is unnecessarily increased, and, when the operation of the compressor is stopped, the amount of high temperature refrigerant flowing into the evaporator due to an internal pressure difference increases, which increase the noise at an outlet of the evaporator. In addition, when the compressor is driven, time to increase the pressure of the condenser 40 to a level required for condensing is lengthened, degrading the efficiency of the refrigerating cycle.
[0037] Thus, by applying the heat exchanger 100 to the condenser 30 of the direct cooling type refrigerator, the length of the pipe of the condenser can be reduced as the heat release efficiency is improved. As a result, the filling amount of the refrigerant required for the refrigerating cycle can be reduced, which reduces the noise generated from the high temperature refrigerant flowing to the evaporator while the compressor is not working, and also reduces the time to reach the condensing pressure required for the condensing operation of the condenser. Therefore, a quiet and quick operation can be implemented.
[0038] In addition, the heat exchanger also can be applied to the evaporator to improve the efficiency of heat transfer of the evaporator, thereby effectively refrigerating the refrigerating chamber or the freezing chamber.
[0039] Implementations of the fin-tube heat exchanger may offer a number of advantages.
[0040] For example, with the wavy fins and the tube attached to the wavy surface of the fins and bent in a zigzag shape, the contact area between the tube and the fins can be maximized in order to increase the heat transfer area between the fins and the tube. Thus, compared to the conventional structure, the efficiency of heat transfer may be improved.
[0041] Also, as noted, the wavy surface of the wavy fins may be attached to the upper and lower surfaces of the tube with the fins surface-attached to the upper surface of the tube and the fins surface-attached to the lower surface of the tube and arranged in an interdigital manner on different planes of the tube. Accordingly, the degradation of heat transfer performance by adjacent fins can be minimized.
[0042] Moreover, because both ends of the fins are attached to the tube in a wrapping manner, the performance of heat transfer between the tube and the fins can be enhanced and the bonding strength between the fins and the tube can be also improved.
[0043] Additionally, by applying the heat exchanger with the improved heat exchange efficiency to the condenser or the evaporator of a direct cooling type refrigerator, the length of the pipe of the condenser or the evaporator can be reduced as the heat release efficiency is improved. Thus, the filling amount of refrigerant required for the refrigerating cycle can be reduced, and an amount of noise generated from the high temperature refrigerant flowing into the evaporator while the compressor is stopped in operation can also be reduced. Also time to reach the condensing pressure required for the condensing operation can be reduced. Thus, quiet and quick operation of the refrigerator can be implemented.
[0044] Other implementations are within the scope of the following claims.
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A heat exchanger includes: fins formed in a wavy shape; and a tube attached with the wavy fins and bent in a zigzag shape. A contact area between the tube and the fins are maximized to thus considerably enhance heat transfer through the fins.
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BACKGROUND OF THE INVENTION
1. Field of the Invention
The present invention relates to calcitonin (CT). More particularly, the present invention relates to the expression of calcitonin in yeasts.
2. Description of the Related Arts
Calcitonin was identified as a hormone factor for reducing the concentration of calcium ion in serum in 1962. It was also noted that calcitonin is secreted by C-cells from the thyroid gland. Busolati G et al. (1967) proposed that calcitonin is composed of 32 amino acids, the first and the seventh cysteines have a disulfide bond, and proline at the C-terminal end is amidated. Sexton, P. M. et al. (1999) reported that the amidation of proline at the C-terminal end is critical for the bioactivity of calcitonin. In vitro study by Sexton, P. M. et al. (1983) and in vivo study by Chamber, T. J. et al. (1983) have demonstrated that the adenylyl cyclase and cAMP dependent protein kinase can be activated by the binding of calcitonin and calcitonin receptor on cell membrane to decrease osteoclast activity thereby alleviating osteoporosis. It is known that calcitonin anticipates calcium ion metabolism and inhibits osteoporosis resulting from osteoclast activity; therefore, calcitonin is considered an effective agent for the treatment of osteoporosis.
Gennari, C. et al. (1999) and Avioli, L. V. (1997) reported that calcitonin provides both a treatment and a preventive effect. Calcitonin can be used clinically to treat bone disorders, such as Paget's disease, osteoporosis, hypercalcemia malignancy. At present, the clinically used calcitonin is derived from human, salmon, porcine, and eel. Sexton, P. M. et al. (1999) reported that the bioactivity of calcitonin derived from salmon is especially high compared to other sources. The present clinically used calcitonin is manufactured through chemical synthesis, which is costly and limited by the length of amino acids. With the development of molecular technology in the last decade, a trend of protein drug production using living organisms (Ivanov, I. 1987; Ishikawa, H. 1996; 1999) has been arisen.
The present technology using recombinant proteins to produce calcitonin can be classified as Escherichia coli production, animal cell production, and yeast production. The advantages and disadvantages of the three productions are discussed in the following.
U.S. Pat. No. 6,210,925B2 to Unigene Laboratories, Inc. discloses a method for calcitonin production by E. coli having the advantage of high production; however, the formation of inclusion bodies in E. coli decreases the solubility of calcitonin.
Takahashi K. I. et al. (Peptides, 1997; 18(3):439–444) disclose a method for calcitonin production by nonendocrine animal cell lines, such as COS-7 and CHO. The last amino acid of the precursor of recombinant calcitonin is glycine which can be amidated easily and the product is identical to naturally occurring calcitonin without any chemical modification. The disadvantages of this method include low production rate and high cost.
Micronova R. et al. (FEMS Microbiology Letter, 1991; 67(1):23–28) disclose a method for human calcitonin production by Saccharomyces cerevisiae . The product can be secreted to the medium and any purification process is unnecessary. The production rate in yeast is between the rates of animal cells and E. coli , however, an additional C terminal amidation is necessary.
The above mentioned methods have several disadvantage, hence there is still a need for calcitonin production with high production rate and simple purification process.
SUMMARY OF THE INVENTION
It is therefore a primary object of the present invention to provide an optimized calcitonin DNA sequence back-translated from a modified calcitonin amino acid sequence in accordance with the codon usage of Saccharomyces cerevisiae to obtain optimized calcitonin expression in yeasts.
Accordingly, one aspect of the present invention features a separate nucleic acid encoding recombinant salmon calcitonin, comprising a nucleotide sequence of SEQ ID No. 2.
The second aspect of the present invention features an expression vector of recombinant calcitonin, comprising a nucleotide sequence of recombinant salmon calcitonin as shown in SEQ ID No. 2.
In another aspect of the present invention, a method for the production of recombinant calcitonin is provided. The method includes the steps of introducing the above expression vector of recombinant calcitonin into a cell, culturing the cell under a condition suitable for the expression of the recombinant calcitonin, and collecting and purifying the recombinant calcitonin.
BRIEF DESCRIPTION OF THE DRAWINGS
The present invention will be more fully understood and further advantages will become apparent when reference is made to the following description of the invention and the accompanying drawings in which:
FIG. 1 is a diagram illustrating a one-copied expression vector (pYEUαSOAK) and the inserted fragment (sCT) in the example of the invention.
FIG. 2 is a photograph showing the sCT:::SOAMY fusion protein in the example of the invention. The left two lines are the expression in EJ758, and the right two lines are the expression in W303; 1 represents negative control, 2 and 3 represent arbitrarily selected two pYEUαSOAK-sCT.
FIG. 3 is a diagram illustrating a multiple-copied expression vector (pYEUUαSOAK) and the inserted fragment (2u circle DNA) in the example of the invention.
FIGS. 4A and 4B are photographs showing the comparison of CT-amylase fusion protein. FIG. 4A represents the electrophoresis result of the expression in DY150-1 and DY150-2; FIG. 4B represents the electrophoresis result of the expression in CK16-1 and CK16-2, and the block underneath represents the activity of the fusion protein. M represents molecular weight marker, the left arrow indicates 66KD and 55KD, and the right arrow indicates 57KD which is the molecular weight of the fusion protein in the invention.
FIG. 5 is a photograph showing the standard quantitative results of the fusion protein and amylase in CK16 after 86 hours. The left four lines are the comparative basis of a standard amylase in 0.5, 1.0, 2.0, and 5.0 μg; the right four lines are the fusion protein of the invention in 0.5, 1.0, 2.0, and 5.0 μg. The calculated production of the invention is about 0.5 μg/5 μg=0.1 g/L.
FIG. 6 is a diagram showing the map of pYEUαsCT in the invention.
FIG. 7 is a photograph showing the comparison of sCT5 secretion in 6 yeast strains. M represents molecular weight marker, + represents positive control, 1 represents CK16, 2 represents DY150, 3 represents AH109, 4 represents TL154, 5 represents Y187, and 6 represents BJ168.
DETAILED DESCRIPTION OF THE INVENTION
Without intending to limit the invention in any way, the present invention will be further illustrated by the following description.
Calcitonin is a hormone protein with a short peptide composed of 32 amino acids. The molecular weight of calcitonin is too small to be analyzed by protein electrophoresis since it cannot be stained easily and may be mixed with small-molecular short-peptides in the bacterial broth. In addition, the bioactivity of calcitonin has to be demonstrated via complicated osteoblast cell culture or animal experiment. The invention provides a simple method for the preparation of calcitonin with a yeast expression vector ligated with an artificial calcitonin designed from naturally occurring salmon calcitonin.
The naturally occurring salmon calcitonin nucleotide sequence designated as S74353 in GENEBANK are shown as below:
(SEQ ID No. 1)
TGC TCC AAC CTC AGC ACC TGT GTG CTG GGC
Cys Ser Asn Leu Ser Thr Cys Val Leu Gly 10
AAA CTG TCC CAA GAG CTG CAC AAA TTG CAG
Lys Leu Ser Gln Glu Leu His Lys Leu Gln 20
ACG TAC CCC CGC ACC AAC ACG GGA AGT GGC
Thr Tyr Pro Arg Thr Asn Thr Gly Ser Gly 30
ACG CCT
Thr Pro 32
In view of the amino acid sequence of calcitonin, it is noted that the sequence of salmon calcitonin has 6 high usage codons and 26 low usage codons in accordance with the codon usage table of Saccharomyces cerevisiae as shown in table 1.
TABLE 1
The codon usage of Saccharomyces cerevisiae
Ala
GCT 0.37
GCA 0.30
Pro
CCA 0.41
CCT 0.31
GCC 0.22
GCG 0.11
CCC 0.16
CCG 0.12
Arg
AGA 0.47
AGG 0.21
Leu
TTG 0.28
TTA 0.28
CGT 0.14
CGA 0.07
CTA 0.14
CTT 0.13
CGC 0.06
CGG 0.04
CTG 0.11
CTC 0.06
Asn
AAT 0.60
AAC 0.40
Lys
AAA 0.58
AAG 0.42
Asp
GAT 0.65
GAC 0.35
Met
ATG 1.0
Cys
TGT 0.62
TGC 0.38
Phe
TTT 0.59
TTC 0.41
Gln
CAA 0.68
CAG 0.32
Trp
TGG 1.0
Glu
GAA 0.70
GAG 0.30
Tyr
TAT 0.57
TAC 0.43
Gly
GGT 0.45
Ser
TCT 0.26
TCA 0.21
GGA 0.23
GGC 0.20
TCC 0.16
AGT 0.16
GGG 0.12
TCG 0.10
AGC 0.11
His
CAT 0.64
CAC 0.36
Thr
ACT 0.34
ACA 0.31
ACC 0.21
ACG 0.14
Ile
ATT 0.46
Val
GTT 0.39
GTA 0.22
ATA 0.28
ATC 0.26
GTC 0.20
GTG 0.20
The salmon calcitonin nucleotide sequence was designed by modifying the codons with low usage rate to have a high usage rate, and the expression of calcitonin in yeasts was then optimized.
The resulting recombinant salmon calcitonin nucleotide sequence of the invention is shown as below:
(SEQ ID No. 2)
TGT TCT AAT TTG TCT ACT TGT GTT CTA GGT
Cys Ser Asn Leu Ser Thr Cys Val Leu Gly 10
AAA TTA TCA CAA GAA TTA CAT AAA TTG CAG
Lys Leu Ser Gln Glu Leu His Lys Leu Gln 20
ACT TAT CCA AGA ACC AAT ACA GGT TCA GGA
Thr Tyr Pro Arg Thr Asn Thr Gly Ser Gly 30
ACA CCT
Thr Pro 32
In addition, a recombinant expression vector for the extracellular secretion of calcitonin fusion protein was constructed. It is noted that calcitonin has an amino acid sequence “Asn-x-Thr/Ser” which may be modified by glycosylation. The glycosylation of this sequence may change the molecular weight and antigenicity of calcitonin and the secreted calcitonin will then be undetectable and cannot be used. To avoid the possible glycosylation of this amino acid sequence during the yeast secretion process, mutant strains with low glycosylation is applied. Moreover, the detection of calcitonin produced from yeasts includes calcitonin antibody detection or the detection of the fusion protein activity. When a suitable expression vector and suitable transformed strains are selected, the expression vector can be constructed again to express calcitonin alone.
Therefore, the invention features an expression vector of a recombinant salmon calcitonin comprising a recombinant salmon calcitonin gene of SEQ ID No. 2. In a preferred embodiment, the expression vector is pYEUαSOAK-sCT.
Another aspect of the invention features a method of producing a recombinant calcitonin, comprising the steps of: introducing the expression vector of the recombinant salmon calcitonin into a cell, culturing the cell in a condition suitable for the expression of the recombinant calcitonin, and collecting and purifying the recombinant calcitonin.
Practical examples are described herein.
EXAMPLE
Example 1
Synthesis of a Full-length Calcitonin by Gene Combination
First, the full-length calcitonin was designed in accordance with the codon usage table of Saccharomyces cerevisiae to be shown as the sequence of SEQ ID No.2. Two primers of about 60 bp were also designed for the sequence. The two primers sharing 20 bp complementary nucleotides are shown as below.
TGT GGT AAT TTG TCT ACT TGT ATG TTA GGT ACA TAT ACC CAA
(SEQ ID No. 3)
GAT TTT AAT AAA TTC CAT
AGG TGC GCC AAC TCC AAT AGC AGT TTG TGG AAA TGT ATG GAA
(SEQ ID No. 4)
TTT ATT AAA ATC TTG GGT
The full-length calcitonin was synthesized by PCR. The 50 μl of reaction solution includes 1 μl each of the two primers (0.1 μg/μl), 4 μl of 2.5 mM dNTPs, 5 μl of 10× Taq Plus buffer, 1 μl of 3 U/μl Taq-Pfu and 38 μl of ddH 2 O. The reaction was performed in a Gene Amp PCR system 2400 (Perkin Elmer) under a condition of: 1 cycle of 98° C. for 5 min, 30 cycles of 98° C. for 2 min, 60° C. for 2 min, 72° C. for 2 min, and a final cycle of 72° C. for 5 min. The PCR product is the full-length calcitonin gene.
The PCR product was used as the template for the second PCR to synthesize calcitonin with restriction sites. Two primers were designed to include XhoI and SnaBI sites, as shown below:
TGT TCT AAT TTG TCT ACT TGT GTT CTA GGT AAA TTA TCA CAA
(SEQ ID No. 5)
GAA TTA CAT
TTG CAG
AGG TGT TCC TGA ACC TGT ATT GGT TCT TGG ATA AGT CTG CAA
(SEQ ID No. 6)
ATG TAA TTC TTG TGA
The 50 μl of reaction solution includes 2.4 μl of the first PCR product, 1 μl each of the two primers (0.5 μg/μl), 2 μl of 2.5 mM dNTPs, 5 μl of 10× Taq Plus buffer, 1 μl of 3 U/μl Taq-Pfu enzyme and 27.6 μl of ddH 2 O. The reaction was performed in a Gene Amp PCR system 2400 (Perkin Elmer) under a condition of: 1 cycle of 98° C. for 5 min, 25 cycles of 98° C. for 1 min, 60° C. for 1 min, 72° C. for 1 min, and a final cycle of 72° C. for 5 min. The PCR product is the calcitonin gene with XhoI and SnaBI restriction sites.
Example 2
The Construction of a Expression Vector for sCT:::SOAMY Secretion
The vector named as pYEUαSOAK (Yeastern Biotech Co., Ltd., Taiwan) was constructed to include centromere (CEN4) and autonomous replicative sequence (ARS). The vector has a length of 9.4 kb and includes an amylase gene SOAMY with a secretion signal αFL. The map of the vector is shown in FIG. 1 . The vector is a circular molecule and can be simultaneously replicated with the yeast chromosome to maintain 1–3 vector molecules for each yeast cell. With this system, the physiology and metabolism of the host cell are not influenced by high intracellular molecules, and the exogenous protein produced in the host cell will not damage the entire host cell. The preferred host cell or vector can be then selected more objectively.
The detailed construction is shown in FIG. 1 . The salmon calcitonin (sCT) was inserted into pYEUαSAOK to form a fusion gene of α-FL:::sCT:::SOAMY. The procedure is recited below. The calcitonin gene fragment with XhoI and SnaBI restriction sites obtained from EXAMPLE 1 and pYEUαSAOK were digested separately. The XhoI digestion was performed first. 50 μl of pYEUαSOAK(1 μg) was added with 2 μl of XhoI(20 U), 0.6 μl of BSA(10 mg/ml), 6 μl of 10× buffer, and 1.4 μl of ddH 2 O to form a total volume of 60 μl. 35 μl of the calcitonin gene fragment obtained from EXAMPLE 1 was added with 2 μl of XhoI (20 U), 0.45 μl of BSA(10 mg/ml), 6 μl of 10× buffer, and 3.05 μl of ddH 2 O to form a total volume of 45 μl. The two reactions were incubated at 37° C. for 16 hours, and SnaBI digestion was then performed. 60 μl of the digested pYEUαSOAK was added with 4 μl of SnaBI (20 U), 0.1 μl of BSA (10 mg/ml), 1 μl of 10× buffer, and 4.9 μl of ddH 2 O to form a total volume of 70 μl. 45 μl of the digested calcitonin gene fragment was added with 4 μl of SnaBI (20 U), 0.25 μl of BSA (10 mg/ml), 2.5 μl of 10× buffer, and 19.25 μl of ddH 2 O to form a total volume of 70 μl. The two reactions were incubated at 37° C. for 4 hours. The digested products were purified by a PCR clean-up kit.
Ten μl of the ligation reactants included 1 μl of sCT, 1 μl of pYEUαSOAK, 1 μl 10× ligase buffer, 1 μl of ligase, and 6 μl of ddH 2 O, and the ligation reaction was performed at 16° C. for 12–16 hours. The next step was transformation. 5 μl of ligated product was added into 100 μl of TOP10 competent cell (stratagene). After a 30 min ice bath, 37° C. incubation for 3 min, and a 10 min ice bath, the bacteria were applied onto an LB/Amp medium and incubated at 37° C. for 16 hours. 10–20 colonies on the LB/Amp medium were separately applied to 200 μl of LB/Amp broth and incubated at 37° C. for 1–2 hours. The colony PCR was performed with a total reaction of 25 μl including 1 μl of the culture broth, 0.5 μl each of primer 1 and 2 (20 μM), 1 μl of dNTPs(2.5 mM), 2.5 μl of 10× Taq buffer, 1 μl of Taq(3 U/μl), and 19 μl of ddH 2 O. The colony PCR was performed in a Gene Amp PCR system 2400 (Perkin Elmer) under a condition of: 1 cycle of 98° C. for 5 min, 25 cycles of 98° C. for 1 min, 55° C. for 1 min, 72° C. for 1 min, and a final cycle of 72° C. for 5 min. The transformant can be confirmed quickly. After sequencing, pYEUαSOAK-sCT was obtained. The vector has GAL1/10 promoter for galactose induction; therefore, the detection of amylolysis acted by SOAMY represents sCT was successfully translated as a part of the fusion protein and secreted into the medium. In addition, the centromere and ARS of the vector provide simultaneously replication with the yeast chromosome and maintain the stability of the vector in the yeast. As shown in FIG. 2 , it is confirmed that sCT:::SOAMY was secreted from the transformants cultured in a solid medium with starch. A negative control (1) and two arbitrary pYEUαSOAK-sCT (2 and 3) were transformed into yeasts EJ758 and W303, respectively, and cultured in YNBD medium (leu+Ura+His+Ala+Met) at 28° C. for 2 days. The results show that the α-amylase reaction did not appear in the negative control, but did appear in both transformants of pYEUαSOAK-sCT. In addition, the bacterial growth in the transformants was normal as in the control group. These results confirmed that the sCT:::SOAMY fusion protein from a one-copied expression vector can be secreted in transformants. Next, a multi-copied vector was constructed for better secretion, and suitable strains for large scale secretion were then screened.
As shown in FIG. 3 , the expression vector with multiple copies was constructed by replacing CEN-ARS1 with 2μ-ori. The replacement was performed by the restriction sites of SpeI and SspBI. The digestion procedure is similar to the above mentioned steps. The obtained expression vector was designated as pYEUαSOAK2μ-sCT.
Example 3
Screening of Saccharomyces cerevisiae Strains for sCT:::SOAMY Fusion Protein and Quantification of the Fusion Protein
The pYEUαSOAK2μ-sCT obtained by EXAMPLE 2 was transformed into 8 strains of Saccharomyces cerevisiae (DY150-1 (Yeastern Biotech Co., Ltd., Taiwan), DY150-2 (Yeastern Biotech Co., Ltd., Taiwan), CK16-1 (Yeastern Biotech Co., Ltd., Taiwan), CK16-2 (Yeastern Biotech Co., Ltd., Taiwan), TL154 (ATCC 96030), AH109 (Clontech com), Y187 (ATCC 96399), and BJ168 (ATCC 4000168)), the strains were cultured in YNBD medium (leu+Ura+His+Ala+Met), and the yeasts were collected at 23, 38, 62, 86 hours. The results were confirmed with SDS-PAGE electrophoresis and coommassie blue staining. It was found that the secretion of the fusion protein in different strains is significantly different as shown in FIGS. 4A and 4B . FIG. 4A shows two mutant strains of a commercialized DY150 strain: DY150-1 and DY150-2, and FIG. 4B shows two mutant strains of CK16 strain which is commonly used for exogenous protein secretion: CK16-1 and CK16-2; the arrow indicates a molecular weight of 57 kD which is the size of the fusion protein in the invention. The results shows that the product secreted by CK16 strains has cumulative ability and the activity of the fusion protein is also cumulative, as shown in the bottom of FIG. 4B .
To determine the quantity of the calcitonin fusion protein, the expression vector of calcitonin fusion protein was transformed to CK16, and the transformed CK16 was cultured for 86 hours and collected. The product was confirmed by SDS-electrophoresis and Coommassie blue staining. The comparative results of the product and standard Aspergillus α-amylase (Sigma) are shown as FIG. 5 . Lines 1, 2, 3, and 4 represent the standard Aspergillus α-amylase diluted to 0.5 μg{grave over ( )}1.0 μg{grave over ( )}2.0 μg{grave over ( )}5.0 μg; lines 5, 6, 7, and 8 represent 86-hour cultured transformed CK16 in 5.0 μl, 2.0 μl, 1.0 μl, and 0.5 μl. The productivity of sCT:::SOAMY fusion protein after 86 hours culturing can be estimated as more than 0.5 μg/5 μl. In the other words, 1 L of transformed yeast may produce more than 100 mg of sCT:::SOAMY fusion protein.
It was found that the influence of different strains on the production of sCT:::SOAMY fusion protein is significant. The commercialized strains such as DY50 have low production rate because the product that experienced over-glycosylation has different molecular weight or is hydrolyzed by protease. This indicates that the genetic influence of strains is important for sCT:::SOAMY fusion protein expression.
Example 4
Construction of YEUαsCT Including sCT Alone and Production of sCT with a Molecular Weight of 4 kd
The results of EXAMPLE 3 proved that sCT:::SOAMY fusion protein can be produced. To produce sCT alone, a sCT expression vector without SOAMY was constructed and designated as pYEUαsCT. The map of pYEUαsCT is shown in FIG. 6 . The molecular weight of sCT produced from this expression vector is about 4kd.
The sCT of 4 kd in pYEUαsCT transformants was determined by silver staining, as shown in FIG. 7 . 6 pYEUαsCT transformants, including 1: CK16, 2: DY150, 3: AH109, 4: TL154, 5: Y187, and 6: BJ168, and one positive control (chemically synthesized sCT, “+”) are shown in FIG. 7 . The results indicate that 1 and 5 produced the predicted product at 4 kd consistent with the molecular weight of the positive control (+). Compared with the positive control, the production rate is about 5 mg/L. Note that the yeasts were not cultured in a fermentor
These examples show that the expression vector including the recombinant salmon calcitonin of the invention can be used in a specific saccharomyces cerevisiae such as CK16 to produce salmon calcitonin with a high production rate. In addition, the protein produced by Saccharomyces cerevisiae is safe. The present chemically synthetic protein has the disadvantages of high cost and is limited by the length of amino acids. The yeast production system of the invention reduces the cost and overcomes the length limitation of chemical synthesis.
While the invention has been particularly shown and described with the reference to the preferred embodiments thereof, it will be understood by those skilled in the art that various changes in form and details may be made without departing from the spirit and scope of the invention.
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Nucleic acid encoding recombinant salmon calcitonin, expression vector thereof, and method for producing recombinant salmon calcitonin therewith. The nucleic acid encoding recombinant salmon calcitonin comprises the sequence of SEQ ID No. 2.
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BACKGROUND
[0001] Light emitting diodes are energy efficient and emit little thermal energy, but because they are small, they are ill-suited to provide meaningful illumination to large, open spaces commonly found in offices. A mechanism for collecting, diffusing and projecting light from several light emitting diodes would be advantageous over the prior art, if such a mechanism could also be manufactured inexpensively. An energy efficient lighting panel that can gather light from numerous diodes or other energy-efficient light sources, diffuse the light so that it does not seem to originate from LEDs or other point sources, and transmit the light would be an improvement over the prior art.
BRIEF DESCRIPTION OF THE DRAWINGS
[0002] FIG. 1 is a perspective view of a light panel;
[0003] FIG. 2 is an exploded view of the light panel depicted in FIG. 1 ;
[0004] FIG. 3 is a perspective view of a first alternate embodiment of the light panel shown in FIG. 1 ;
[0005] FIG. 4 is an exploded view of another alternate embodiment of a light panel;
[0006] FIG. 5 is a perspective view of another embodiment of a light panel;
[0007] FIG. 6 is an exploded view of the structure shown in FIG. 5 ;
[0008] FIGS. 7-10 depict alternate embodiments of the web sections used to strengthen and provide hollows for an illumination panel; and
[0009] FIGS. 11-14 show other embodiments of a light panel.
DETAILED DESCRIPTION
[0010] FIG. 1 is a perspective view of a light panel 100 . The light panel 100 is comprised of an illumination panel 102 having an upper surface 103 , which is both light transmissive and light diffusive. Light sources located along the edges of the panel project light inwardly, i.e., into the panel from the edges. The light sources emit a uniform level of light energy such that light transmitted through the panel's surface appears to originate from either a uniformly distributed light source behind the panel, or numerous individual light sources behind the panel, rather than light sources located along its edges and which project light into empty space beneath the upper surface 103 .
[0011] As used herein, the term “transmissive” should be construed to mean that light is able to pass-through the panel. The term “diffusive” should be construed to mean tending to diffuse. Since “diffuse” means not concentrated or not localized, diffusive should be construed to mean tending to diffuse, de-localize or not concentrate. By way of example, an incoherent, i.e., non-laser, point light source located behind the upper surface 103 will thus appear to be larger and will tend to make the upper surface 103 appear as if it is entirely illuminated from its back side, which, not shown but within the body of the light panel 100 .
[0012] The light panel 100 is also comprised of a back side 104 , not visible in FIG. 1 because FIG. 1 is a perspective view of the light panel 100 . The upper surface 103 and the back surface 104 are separated from each other by a separation distance 105 . The separation between the upper surface 103 and the back surface 104 is maintained by one or more internal web sections, not visible in FIG. 1 .
[0013] A left end cap 106 and a right end cap 107 enclose one or more elongated hollows, which as described below, extend between the left end cap and the right end cap and through which light from a light source travels. Since the light waves from light sources used with the panel 102 are incoherent, at least part of the light traveling through the hollows passes through the light transmissive and light diffusive upper surface 103 .
[0014] FIG. 2 is an exploded view of the light panel 100 depicted in FIG. 1 . The upper light transmissive and light diffusive surface 103 is planar. It is formed by extruding a plastic material thin enough to allow light to pass through it and to diffuse the light. The hollows are identified by reference numeral 202 . Vertical side walls identified by reference numeral 204 , are considered herein to be the aforementioned web sections 204 . The entire panel, including the top, bottom and side walls are preferably formed by one extrusion, all at once.
[0015] The hollows 202 have first and second ends. The first end being proximate to the left end cap 106 , the second end being proximate to the right end cap 107 . As stated above, the hollows 202 are formed by a substantially vertical wall that forms the aforementioned web section 204 . Several web sections are shown in FIG. 2 , each of which extends between the upper light transmissive surface 103 and the back surface 104 . Since the upper light transmissive and light diffusive surface 103 of panel 102 , the web sections 204 and the back surface or backside 104 are formed by extruding a plastic, all of them preferably have the same light transmissive and light diffusive properties allowing any of the surfaces to be used as light emitting.
[0016] Two light strips 206 and 209 are comprised of integrated circuit boards, attached to which are light sources 208 such as light emitting diodes or incandescent bulbs. Electric energy is provided to the light sources 208 by connecting wires 205 and 207 to a power source. For brevity, light emitting diodes, incandescent bulbs or other light types are collectively referred to hereinafter as light sources, which are identified in FIG. 2 by reference numeral 208 .
[0017] The bodies of the light sources 208 project into the hollows 202 by a small distance. Since the light sources are mounted to a circuit board, the surface of which is held against the ends of the extruded panel 102 , and projects into the hollows, the light sources 208 are thus considered herein to be operatively coupled to the corresponding left end 210 and the right end 212 of the extrusion which forms the extruded light transmissive and light diffusive panel 102 . The light sources 208 direct light into the hollow and of course, along the back or reverse or interior side of the upper surface 103 .
[0018] Light emitted from the light sources 208 will of course travel down the hollows 202 . Since the light is incoherent, at least part of the light passing through the hollow will also pass through the upper surface 103 because the upper surface is transmissive as well as diffusive. Inasmuch as the web structures 204 and the back surface 104 are also formed from the same plastic, the light from the light source 208 will also pass at least partly through those surfaces as well, unless the surfaces of those structures are coated with an opaque or reflective material.
[0019] The back surface 104 of the extruded panel 102 , which is opposite the top surface 103 , has its own “upper surface” 203 , which is “inside” the hollow 202 or facing into the hollow 202 . In one embodiment, the top or interior surface 203 of the back surface 104 is coated with a polished aluminum or other reflective surface. Such a coating will tend to direct the incoherent light from the light sources 208 upwardly or out through the top or upper surface 103 of the light transmissive panel 102 . The back surface 104 could also be coated with a reflective material to provide a similar result.
[0020] FIG. 3 is a perspective view of a first alternate embodiment of the light panel 100 shown in FIG. 1 . In FIG. 3 , the light panel 300 is comprised of an extruded plastic that is transmissive but not diffusive. An upper surface 303 is coated or overlaid with a light transmissive and light diffusive film 304 . In one embodiment, the film 304 passes all light wavelengths, in which case the entire upper surface 302 of the panel 300 will appear to emit white light when a white light passes through the hollows 305 . In another embodiment, the diffusive film 304 allows narrow bands or ranges of wavelengths to pass through, i.e., the film 304 appears to be colored or tinted. In such an embodiment, the entire panel 300 will thus appear to emit a uniform or substantially-uniform colored light. Color added to the film 304 can also be patterned or areas of the film colored differently and randomly.
[0021] FIG. 4 is an exploded view of an alternate embodiment of the light panel 100 depicted in FIG. 1 . A plastic that is at least partially light transmissive and light diffusive 402 is extruded to form the same illumination panel structure that is shown in FIG. 1 but which is identified in FIG. 4 by reference numeral 402 .
[0022] A substantially planer upper surface 403 and a substantially planer lower surface 404 are separated from each other by substantially vertical web sections 405 that maintain the separation distance between the upper surface 403 and the lower surface 404 . The web sections in each embodiment also provide flexural rigidity to the panel 402 . Spacing between the web sections 405 is a design choice, however, those of ordinary skill will recognize that panel stiffness will be directly proportional to the number of web sections. The greater the number of web sections 405 , the stiffer the panel 402 will be, but at the expense of additional material and therefore cost to provide additional extruded web sections 405 .
[0023] Unlike the light strips 206 and 209 shown in FIG. 2 , the illumination panel 400 shown in FIG. 4 is provided with two, substantially cylindrical, conventional fluorescent tubes 408 and 409 , which are also considered herein to be light sources. The light sources 408 and 409 are shown located outside or beyond the left end 406 of the panel 402 and the right end 410 of the panel 402 . The light sources 408 and 409 are thus considered to be outside of the hollows 407 formed by the aforementioned web sections 405 . End caps 411 and 412 are sized, shaped and arranged to frictionally engage the upper surface 403 and the opposing rear surface 404 the front wall 413 and an opposing back wall 414 to hold the light sources 410 up against the web sections 405 yet remain outside the hollows 407 .
[0024] FIG. 5 is a perspective view of yet another embodiment of a light panel 100 . FIG. 6 is an exploded view of the same structure.
[0025] Referring now to FIG. 6 , an extruded, transmissive and diffusive illumination panel 502 has a planar upper light transmissive and light diffusive surface 503 spaced apart and separated from a rear surface 504 by several web sections 602 .
[0026] Two light strips 604 and 605 are each comprised of substantially U-shaped light pipes 606 . As used herein, “light pipe” should be construed to mean an optical fiber or a solid transparent plastic rod that transmits light lengthwise, i.e., along the length of the light pipe structure. In FIG. 6 , the light pipes 606 are substantially U-shaped. Light sources 607 on light strips 604 and 605 direct light into the light pipes 606 , which conduct the light in a U-shaped material, into the hollows 603 . Light emitted from the externally-located light sources 607 is projected into a first or upper end 608 of the U-shaped light pipe 606 . At the lower end 609 , light leaves the light pipe and projects into the hollows 603 where at least part of the light travels through the hollow and at least part of that light passes through the light transmissive and light diffusive top surface 503 . The light sources 607 in FIG. 6 are thus spatially separated from the hollows 603 yet transmit light through the light conduits embodied as the light pipes 606 . For purposes of claim construction, a light pipe 606 in combination with a light source 607 should also be considered to be a light source.
[0027] FIGS. 7-10 depict alternate embodiments of the web sections used to “rigidize” or strengthen an extruded plastic, illumination panel.
[0028] FIG. 7 depicts the web cross section shown in FIG. 2 . The web sections 702 are uniformly spaced, vertical or substantially vertical, relative to the top surface 700 of the panel and the bottom surface 704 to form a single-layered illumination panel.
[0029] In FIG. 8 , an intermediate layer 804 is separated from a top layer 800 and a bottom layer 806 by web sections 802 that extend between both the top layer 800 and bottom layer 806 .
[0030] FIG. 9 depicts a web section reminiscent of a honeycomb. Hexagonally-shaped hollows 900 are formed by extruding. The wall sections between the hexagonally-shaped hollows are sufficiently thin so that light sources in any one of the hexagonally-shaped hollows are able to transmit light through the most distant of the upper surface 902 and the lower surface 904 .
[0031] FIG. 10 shows a random cross-sectional shape web the hollows 1000 of which are also randomly shaped.
[0032] FIG. 11 shows yet another embodiment of a light panel 1100 . A substantially planar lower surface 1104 is separated by an upper curved surface 1102 by vertically-oriented web sections 1106 , the lengths of which change according to the desired curvature of the upper surface 1102 . The curved surface provided by the upper surface 1102 provides a more decorative and textured light source panel than do planar or substantially planar surfaces illustrated in FIGS. 1-10 when the curved surface faces into a living space where it can be seen.
[0033] FIG. 12 depicts yet another light transmissive panel 1200 . Two concentric light transmissive and light diffusive surfaces 1202 and 1204 have circular cross-sectional shapes. They are spaced apart from each other by several radially-oriented web sections 1206 , which define hollows 1208 . Each hollow 1208 thus forms a partial annulus and able to receive one or more of the light sources described above.
[0034] FIGS. 13A and 13B depict yet another embodiment of a light panel 1300 . In this figure, the light panel 1300 is substantially pie-shaped having an outer edge 1302 and an inner edge 1304 between which extend several vertically-oriented web sections 1306 which maintains the spacing between a light transmissive and light diffusive upper surface 1308 and an optionally light transmissive and light diffusive lower surface 1310 . The hollows 1312 are themselves pie-shaped sections defined by the radially-oriented web sections 1306 . Light sources can be placed into the pie-shaped hollows at either the outer edge 1302 or the inner edge 1304 .
[0035] Finally, FIG. 14A depicts a perspective view of another embodiment of an illumination panel 1400 . The panel is comprised of a light transmissive and light diffusive upper surface 1402 and a light transmissive and light diffusive lower surface 1404 . As shown in FIG. 14A , the surfaces 1402 and 1404 are separated from each other by a plurality of posts 1406 that extend between the two surfaces 1402 and 1404 . A hollow 1408 is embodied as the space between the panels and around the posts 1406 . As can be seen in FIG. 14B , light sources such as those describe above, can be inserted into the hollow or fixed adjacent to its open edges projecting light into the hollow which will be reflected out of at least one of the surfaces 1402 and 1404 .
[0036] It should be apparent to those of ordinary skill that the illumination panels can have opaque and transmissive sides that are either flat or curved. Light sources can be operatively coupled to hollows in illumination panels by being at least partially within a hollow, adjacent to or away from the hollow with emitted light conducted into the hollow by a light pipe.
[0037] As used herein, the term “web” refers to regular or irregular shapes that maintain a space between surfaces that comprise an illumination panel but which also define a “hollow” through which light will pass lengthwise but also be emitted through a transmissive side of the panel.
[0038] The illumination panel is preferably formed by extruding, however any method of manufacture can be used to construct the aforementioned light panel. A plastic for extruding should be selected that is both transmissive and diffusive, however, a clear or translucent plastic or acrylic can also be used with an overlaid diffusive layer.
[0039] The foregoing description is for purposes of illustration. The true scope of the invention is set forth in the appurtenant claims.
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A light-weight and energy-efficient lighting panel is constructed from a light-transmissive and light diffusive extrusion formed to have elongated hollows, which are hollow structures or volumes between two surfaces, at least one of which is transmissive and diffusive. Light projected into the hollow flows through the hollow and part of the light is emitted through the light transmissive and diffusive surfaces. Even though the light sources are located at the edges of a panel, the surface of the panel appears to be uniformly light by light sources distribute directly behind the panels rather than along the edges.
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CROSS REFERENCE TO RELATED APPLICATIONS
[0001] This application is for entry into the U.S. national phase under §371 for International Application No. PCT/EP2005/055320 having an international filing date of Oct. 17, 2005, and from which priority is claimed under all applicable sections of Title 35 of the United States Code including, but not limited to, Sections 120, 363 and 365(c), and which in turn claims priority under 35 USC §119 to German Patent Application No. 102004050806.2 filed Oct. 16, 2004.
BACKGROUND OF THE INVENTION
[0002] 1. Technical Field
[0003] The invention concerns a process and a reactor arrangement for the production of a gallium nitride crystal or an aluminium gallium nitride crystal.
[0004] 2. Discussion of Related Art
[0005] Single crystals of group III nitride compounds can be used as high-grade, low-dislocation substrates for group III nitride semiconductor epitaxy, in particular for blue or UV lasers. At the present time however such substrates are only limitedly available and are extremely costly: production is restricted to small areas or, in the case of pseudosubstrates which are produced by means of hydride gaseous phase epitaxy on foreign substrates, is limited to a few millimetres in thickness due to the procedure involved. The result of this is that low-dislocation substrates can be produced only at a high level of complication and expenditure and are correspondingly costly. Growth out of a melt, for example similarly to the liquid encapsulated Czochralski method in the case of GaAs has not been successful hitherto and is also not possible in the foreseeable future by virtue of the very high nitrogen vapour pressures which occur over a melt.
[0006] In contrast single crystals of AIN are primarily produced at the present time by means of sublimation procedures at very high pressures. For that purpose AIN powder is heated, sublimated and diffuses to the colder end of the growth chamber where an AIN crystal then grows. Disadvantages here are difficulties in scalability, the high level of contamination of the single crystal and the crystals which are always still very small and which can be only limitedly used for epitaxy. Direct growth from aluminium vapour and NH 3 is already described for example by Witzke, H-D: Über das Wachstum von AIN Einkristallen, Phys Stat sol 2, 1109 (1962) and Paster{hacek over (n)}ák J and Roskovcová L: Wachstum von AIN Einristallen, Phys Stat sol 7, 331 (1964). Here a large number of small single crystals were grown, which are suitable for fundamental research in material sciences, but are not suitable for epitaxy of structural elements. Group III nitride epitaxy of semiconductor lasers necessitates first and foremost GaN substrates in respect of which a similar process is simply not possible as that involves the troublesome formation of GaN on the gallium melt, as described for example by Balkas, C M et al: Growth and Characterization of GaN Single Crystals, Journal of Crystal Growth 208, 100 (2000), Elwell, D et al: Crystal Growth of GaN by the Reaction between Gallium and Ammonia, Journal of Crystal Growth 66, 45 (1984), or Ejder E: Growth and Morphology of GaN, Journal of Crystal Growth 22, 44 (1974). Elwell et al mentions in particular a surface reaction which was always observed between metallic gallium and ammonia, with the result that small crystals grow on the gallium melt and also at reactor parts covered by gallium.
[0007] At the present time so-called pseudosubstrates are produced for the growth of semiconductor lasers on GaN, by means of hydride gaseous phase epitaxy procedures, such as for example in the case of one of the largest manufacturers of such substrates, Sumitomo of Japan, see JP002004111865AA. Here the gallium metal reacts in a region separated from the nitrogen precursor ammonia to provide gallium chloride by passing chlorine thereover, which then in turn reacts over a substrate with ammonia to give GaN and ammonium chloride. The latter compound is extremely problematical in terms of crystal growth as it occurs in large amounts and as a solid can cover or clog the reaction chamber and the exhaust gas system and often interferes with the crystal growth due to severe particle formation.
[0008] Alternatively GaN wafers are produced at high pressures and temperatures from a gallium melt, see U.S. Pat. No. 6,273,948 B1 and Grzegory, I et al: Mechanisms of Crystallization of Bulk GaN from the Solution under high N 2 Pressure, Journal of Crystal Growth 246, 177 (2002). In this case however sizes adequate for commercial exploitation have hitherto not been achieved and the crystals in part present high levels of oxygen concentration, which admittedly makes them highly conductive but which makes them susceptible to lattice defects in comparison with high-purity epitaxial GaN. The production of GaN single crystals directly from or in metal melts (U.S. Pat. No. 6,592,663 B1), in part with the result of relatively large but thin single crystals, is also known, but hitherto could not prove successful probably because of the reported high levels of carbon inclusions (see Soukhoveev, V et al: Characterization of 2.5-Inch Diameter Bulk GaN Grown from Melt-Solution, phys stat sol (a) 188, 411 (2001)) and the slight layer thickness.
[0009] The slight progress made in the study of the production of GaN single crystals, extending over 40 years, is astonishing in that respect. In that connection, as already mentioned, most works are concerned with the production of crystals from melts or from the gaseous phase by the reaction of gallium chloride and ammonia. Few works are concerned with the reaction of molten gallium and a reactive nitrogen precursor such as for example ammonia and then always involving direct contact of the substances at the melt such as for example in the works by Shin, H et al: High temperature nucleation and growth of GaN crystals from the vapor phase, Journal of Crystal Growth, 241, 404 (2002); Balkas, C M et al: Growth and Characterization of GaN Single Crystals, Journal of Crystal Growth 208, 100 (2000); Elwell, D et al: Crystal Growth of GaN by the Reaction between Gallium and Ammonia, Journal of Crystal Growth 66, 45 (1984); or Ejder, E: Growth and Morphology of GaN, Journal of Crystal Growth 22, 44 (1974). Shin describes that a crust is formed on the gallium melt, which interferes with the crystal growth due to droplet formation, caused thereby, of the gallium on surrounding walls. In particular, with those methods a large number of small crystals are always produced in the reaction chamber and the crystal growth is for the major part uncontrolled and is therefore not suitable for large single crystals but is suitable for small, very high-grade crystals for research applications.
[0010] JP 11-209 199 A discloses a reactor arrangement for the production of GaN single crystals with what is referred to as a hot wall process. A disadvantage of the process described therein, for use on a large technical scale, is an excessively low level of attainable growth rate for the single crystal.
[0011] The underlying technical problem of the present invention is to provide a process and a reactor arrangement for the production of gallium nitride crystals or aluminium gallium nitride crystals, which permits crystal growth by the reaction of molten gallium with a reactive nitrogen precursor without crust formation on the gallium melt and the problems involved therewith in terms of crystal growth and with an improved growth rate.
DISCLOSURE OF INVENTION
[0012] A first aspect of the present invention concerns a process for the production of a gallium nitride crystal or an aluminium gallium nitride crystal. The process comprises the steps:
providing a metal melt of pure gallium or a mixture of aluminium and gallium in a melting crucible; vaporisation of gallium or gallium and aluminium out of the metal melt; decomposing a nitrogen precursor by thermal effect or by means of a plasma; and causing single-crystalline crystal growth of a GaN or AlGaN crystal on a seed crystal under a pressure of less than 10 bars.
[0017] The vaporisation of gallium or gallium and aluminium is effected at a temperature above the temperature of the growing crystal but at least at 1000° C.
[0018] The process according to the invention provides that a gas flow of nitrogen gas, hydrogen gas, inert gas or a combination of those gases is passed over the metal melt surface in such a way that the gas flow over the metal melt surface prevents contact of the nitrogen precursor with the metal melt.
[0019] The process according to the invention forms an alternative to the growth of gallium nitride or aluminium gallium nitride by liquid phase hydride epitaxy processes or by the simple reaction of gallium vapour and ammonia. The process according to the invention provides that pure metal is vaporised and transported in a gas flow into a reaction region where single-crystalline crystal growth of a GaN or AlGaN crystal is produced on a seed crystal. The problem of the low vapour pressure of gallium is overcome with the process according to the invention in that a temperature of at least 1000° C., which is suitable for appropriate growth rates of the crystal, is set for the vaporisation of gallium or gallium and aluminium.
[0020] Furthermore the process according to the invention resolves the problem of the direct reaction of gallium with the nitrogen precursor, that is frequently observed, insofar as a gas flow of nitrogen gas, hydrogen gas, inert gas or a combination of those gases is passed over the metal melt surface, more specifically in such a way that the gas flow over the metal melt surface prevents the nitrogen precursor from coming into contact with the metal melt. In this case different operative mechanisms can be used depending on the respective gas employed. An inert gas such as for example helium, argon or nitrogen (N 2 ) can prevent the contact between the melt and the nitrogen precursor when the gas flow is suitably guided and involves a suitable flow speed. Depending on the respective reactor pressure and the flow speeds involved on the other hand, when using nitrogen gas, a crystalline GaN or AlGaN layer which is being formed on the melt can be broken down by virtue of the high reactivity of the hydrogen which occurs at the high temperature of the melt, thereby ensuring further vaporisation of the metal.
[0021] Nitrogen gas is referred to here separately from the inert gases although it has properties of an inert gas, namely it does not involve any chemical reaction with the metal of the melt (or with the nitrogen precursor). That applies however only at lower temperatures at which nitrogen is present in molecular form (N 2 ). At temperatures of the metal melt of for example 1400° C., which are also embraced by the process according to the invention, nitrogen is present in atomic form and in principle can react with gallium and therefore does not form an inert gas. At such high temperatures however atomic nitrogen can nonetheless be passed over the metal melt without having to tolerate crusting because GaN is not stable in that temperature range.
[0022] A combination of the two specified operative mechanisms is also possible, insofar as a gas flow which contains both hydrogen gas and also an inert gas is passed over the metal melt surface, or insofar as a plurality of gas flows are passed over the metal melt surface, wherein one gas flow is formed by inert gas and another gas flow is formed by gas containing or consisting of hydrogen.
[0023] The process according to the invention provides that uniform growth of a single crystal is promoted on a large area, by the growth beginning on a seed crystal. In that fashion, the process according to the invention permits the production of gallium nitride or aluminium gallium nitride substrates.
[0024] Alternatively however the seed crystal can also be designed for a small surface area. A GaN rod then grows first. That is helpful for reducing dislocation concentrations which initially are inevitably high. A clever choice in respect of the gas composition, in particular the V/III ratio, and the pressure can then promote lateral growth on a desired diameter and ultimately can provide for the growth of a long GaN rod of a diameter which is also adequate for substrate production.
[0025] In comparison with the known hydride epitaxy process the process according to the invention has the advantage of not producing any troublesome deposits. In the case of hydride epitaxy for example the use of gallium chloride and ammonia causes the production of ammonium chloride deposits which impede the growth of large crystals.
[0026] As a result therefore the described method is ideally suited for the mass production of large single crystals from which substrates for the epitaxy of group III nitrides can later be produced by sawing and polishing. Furthermore the process according to the invention, by virtue of the crystal size which can be achieved, minimises reaction wear, as is the rule with hydride gas phase epitaxy in quartz glass reactors. For, in hydride gaseous phase epitaxy, the growing layer tears away the quartz glass used at the latest when cooling takes place. The pseudosubstrates produced with hydride gaseous phase epitaxy are therefore very expensive to produce. In contrast, the process described here means that a large number of substrates can be sawn from a crystal, even if an inner covered part of the reactor breaks off. The price per substrate can be markedly reduced in that way.
[0027] The process according to the invention is limited in terms of crystal size solely by the temperature homogeneity at the location of crystal growth and by the amount of molten gallium. As gallium is liquid from 27° C. however gallium can be refilled by a feed thereof during operation, that is to say in production of the crystal.
[0028] Embodiments of the process according to the invention are described hereinafter.
[0029] An embodiment of the process according to the invention provides that the metal melt is provided in a melting crucible vessel which, apart from at least one carrier gas feed and at least one carrier gas outlet opening, is closed on all sides. In this embodiment the gas flow is introduced into the melting crucible vessel through the carrier gas feed above the metal melt and transported with metal vapour of the metal melt out of the melting crucible vessel through the carrier gas outlet opening.
[0030] This embodiment affords an increased level of protection from crust formation on the surface of the metal melt, supplemental to the gas flow, insofar as the melting crucible vessel is closed on all sides except for the described gas feed and discharge means. In that way the structural configuration of the crucible ensures that reaction of the molten metal does not take place on the surface of the metal melt but only in the reaction region provided for that purpose near the seed crystal or the growing single crystal. Furthermore, the closed structural configuration of the melting crucible provides advantageous flow conditions for transport of the metal atoms vaporised out of the metal melt, towards the growing crystal.
[0031] In an alternative embodiment the provision of the metal melt includes arranging the melting crucible in a reactor chamber, wherein here at least one carrier gas feed into the reactor chamber is provided. In this embodiment the gas flow is introduced into the reactor chamber through the carrier gas feed slightly above the metal melt. The nitrogen precursor is introduced into the reactor chamber through the precursor inlet opening in a reaction region. In comparison with the preceding embodiment this embodiment substantially dispenses with the surface of the metal melt being covered over by the structural configuration of the melting crucible, and with the carrier gas feed into the melting crucible. The melting crucible can therefore be produced in a particularly simple and inexpensive fashion.
[0032] In both alternative process implementations, the gas flow is introduced into the melting crucible vessel or into the reactor chamber either in a direction in parallel relationship with the surface of the metal melt or in a direction in perpendicular relationship with the surface of the metal melt.
[0033] In a further preferred embodiment of the process the vaporisation of gallium or gallium and aluminium is effected at a temperature of at least 1100° C. The metal vapour pressure which is increased thereby can be used to accelerate crystal growth.
[0034] Various substances can be introduced into the reactor chamber for specifically targeted doping of the growing single crystals. In a first alternative that can be effected by the introduction of a gaseous precursor, silicon or germanium hydride compounds such as for example silane, germane, disilane or digermane can be used for n-type doping. Metallorganic compounds such as for example tertiary butyl silane are also suitable for doping. A corresponding consideration also applies to p-doping. Magnesium is predominantly suitable here, which can be passed into the reaction chamber with a carrier gas very easily, for example in the form of metallorganic cyclopentadienyl magnesium. For example iron in the form of cyclopentadienyl iron, also known as ferocene, or other transition metals which produce low impurity levels as far as possible in the middle of the band gap of the semiconductor crystal produced are suitable for the production of high-ohmic crystals.
[0035] A second alternative process implementation for doping provides that a dopant such as for example silicon, germanium, magnesium or iron is vaporised as pure melt, or the respective solid is sublimated. For that purpose, a further temperature zone or a separately heated crucible is required in the reactor. In most cases, similarly to the gallium-bearing melt, that crucible also has to be protected from nitriding, which can be effected in a quite similar fashion to the process implementation using the melting crucible of the group III metal by a gas flow.
[0036] In an embodiment in which the gas flow contains or consists of hydrogen the provision of the metal melt in a melting crucible preferably includes the use of a melting crucible of boron nitride BN, tantalum carbide TaC, silicon carbide SiC, quartz glass or carbon or a combination of two or more of those materials. Experience has shown that a crucible made solely from carbon disintegrates after a few hours of operation with a hydrogen feed. In that case therefore a carbon crucible should be coated with one of the other materials specified.
[0037] A second aspect of the invention is formed by a reactor arrangement for the production of a gallium nitride crystal or a gallium aluminium nitride crystal. The reactor arrangement according to the invention includes
a device for feeding a nitrogen precursor into a reaction region of a reactor chamber, a device for decomposition of the nitrogen precursor in the reaction region by thermal action or by means of a plasma, a melting crucible for receiving a metal melt of pure gallium or a mixture of aluminium and gallium, a first heating device which is adapted to set the temperature of the metal melt in the melting crucible to a value above the temperature of the growing crystal but at least at 1000° C., a carrier gas source which is adapted to deliver nitrogen gas, hydrogen gas, inert gas or a combination of said gases, and at least one carrier gas feed which is connected to the carrier gas source and which is arranged and adapted to pass a gas flow over the metal melt surface in such a way that the gas flow prevents contact of the nitrogen precursor with the metal melt.
[0044] The advantages of the reactor arrangement according to the invention arise directly out of the above-described advantages of the process according to the invention.
[0045] Preferred embodiments by way of example of the reactor arrangement are described hereinafter. A detailed representation will be waived insofar as embodiments directly represent an apparatus aspect of an embodiment, already described in detail hereinbefore, of the process in accordance with the first aspect.
[0046] In an embodiment of the reactor arrangement according to the invention the melting crucible is in the form of a melting crucible vessel which, apart from the carrier gas feed and at least one carrier gas outlet opening, is closed on all sides. The carrier gas feed is arranged above the surface of the metal melt.
[0047] In a variant of this embodiment the first heating device is adapted to heat the walls of the melting crucible vessel above the metal melt to a higher temperature than in the region of the metal melt. That prevents droplets being formed in the rising metal vapour, which droplets can also be deposited in the melting crucible or at the walls of the reactor chamber outside the melting crucible.
[0048] Instead of a heating device which produces different temperature ranges it is also possible to provide two heating devices. In this embodiment the carrier gas outlet opening can form the end of a tubular outlet. A second heating device is then adapted to heat the walls of the tubular outlet to a higher temperature than the first heating device heats the walls of the melting crucible vessel in the region of the metal melt.
[0049] In different embodiments, the carrier gas feed is adapted to introduce a gas flow into the melting crucible vessel or the reactor chamber in a direction in parallel relationship with the surface of the metal melt or in perpendicular relationship with the surface of the metal melt. It is also possible to provide a plurality of feeds, of which one provides for introduction in perpendicular relationship to the surface of the melt and another provides for introduction in parallel relationship with the surface of the melt.
[0050] Various alternative configurations of the carrier gas feed are described in greater detail hereinafter with reference to the Figures.
[0051] It is preferable, in particular for the use of hydrogen gas, for the melting crucible to be made from boron nitride BN, tantalum carbide TaC, silicon carbide SiC, quartz glass or carbon, or a combination of two or more of those materials.
[0052] For the growth of GaAl crystals, it is possible to provide a melting crucible for a corresponding metal mixture, as described. Alternatively, two separate melting crucibles can also be arranged in the reactor chamber, of which one contains a gallium melt and the other an aluminium melt. In this embodiment, the ratio of the two metals in the growing crystal can be adjusted by separate setting of the two melting crucible temperatures and by the respective carrier gas flow into the two crucibles.
BRIEF DESCRIPTION OF THE DRAWINGS
[0053] Further embodiments of the process according to the invention and the reactor arrangement according to the invention are described hereinafter with reference to the accompanying Figures in which:
[0054] FIG. 1 is a diagrammatic view of a first embodiment of a reactor arrangement,
[0055] FIGS. 2-8 show various alternative configurations of melting crucibles for use in a reactor arrangement according to the invention, and
[0056] FIG. 9 shows a second embodiment of a reactor arrangement for the production of a GaN or AlGaN crystal.
DETAILED DESCRIPTION
[0057] FIG. 1 shows a simplified diagrammatic view of a first embodiment of a reactor arrangement 100 . The reactor arrangement 100 is a vertical reactor. In a lower portion thereof, a reactor vessel 102 contains a melting crucible A which contains a gallium melt (not shown). A high frequency heating means 104 heats the gallium melt by means of a high-frequency electrical alternating field. A high frequency heating means of that kind is ideally suitable for achieving a high temperature to over 2000° C. because it operates with a low level of maintenance and in contact-free fashion. Disposed just above the melting crucible is a carrier gas feed 106 in the form of gas lines 106 . 1 and 106 . 2 which are arranged at the same height and in opposite relationship, that is to say with their openings facing towards each other. Outlet openings 108 . 1 and 108 . 2 are arranged at a small lateral spacing from the melting crucible A. As the melting crucible A is open upwardly that arrangement of the carrier gas feed 106 can produce a gas flow which is guided directly over the surface of the metal melt.
[0058] The nitrogen precursor is introduced through precursor feed lines 110 . 1 and 110 . 2 into a reaction region 112 which is disposed just below a gallium nitride crystal 112 growing on the basis of an originally present seed crystal. The gallium nitride crystal is fixed to a holder 114 which can be controlledly displaced in the vertical direction (indicated by a double-headed arrow 116 ) by means of a suitable adjusting device (not shown). That is effected on the one hand for introducing the seed crystal into the reactor chamber and on the other hand for holding the currently prevailing growth surface of the crystal being formed, at the same vertical position.
[0059] In the arrangement shown in FIG. 1 the gas flow caused by the carrier gas feed lines 106 . 1 and 106 . 2 provides for transport of gallium-rich vapour out of the region of the metal melt in the melting crucible A in the direction of the growing crystal 112 . That is necessary first and foremost in operation under high pressure as otherwise the gallium vapour is propagated only by diffusion. If the reactor walls were colder, gallium vapour would be deposited there so greatly that, depending on the respective spacing between the melting crucible A and the crystal 112 , the gallium vapour does not reach the crystal at all or reaches it only in a reduced amount.
[0060] Besides the gas inlets 106 . 1 and 106 . 2 shown in FIG. 1 the carrier gas feed 106 can include further gas inlets through which a further gas flow is produced in the lower part of the reaction chamber 102 , which further gas flow can alter the gas mixture. The introduction of gas through the feed line 106 . 1 and 106 . 2 crucially controls the composition of the gas atmosphere in the region of the melting crucible A. The gases H 2 and N 2 which are available in a high level of purity are most suitable. In the present example for example the ratio of H 2 and N 2 could be altered by means of further gas inlets, whereby the crystal growth can be specifically targetedly influenced and in addition deposits at the walls of the reactor chamber 102 can also be reduced.
[0061] In that respect, in the present embodiment of a vertical reactor, it is advantageous that the outlet openings are arranged in mutually opposite relationship. Transport of the gallium vapour upwardly is improved in that way.
[0062] As an alternative to the illustrated arrangement of the precursor feed lines 110 . 1 and 110 . 2 , they can also be arranged above the growth surface 118 of the crystal 112 being produced. In that case the nitrogen precursor then diffuses against the gas flow which leads to an outlet 120 at the upper end of the reactor chamber to the growth front 118 at the lower end of the crystal. The lateral and vertical crystal growth can be controlled to a slight degree by the vertical position of the nitrogen feeds 110 . 1 and 110 . 2 .
[0063] Various substances can be introduced into the reactor chamber for specifically targeted doping of the growing single crystals. That can be done by the introduction of a gaseous precursor. Silicon or germanium hydride compounds such as for example silane, germane, disilane or digermane can be used for n-type doping. Metallorganic compounds such as for example tertiary butyl silane are also suitable for doping and can be introduced into the reaction chamber for n-doping. A corresponding consideration applies to p-doping. Predominantly magnesium is appropriate here, which can be very easily introduced into the reaction chamber, for example in the form of metallorganic cyclopentadienyl magnesium, with a carrier gas. For high-ohmic layers for example iron in the form of cyclopentadienyl iron, also known as ferocene, is also appropriate, or other transition metals which produce deep impurity levels as far as possible in the middle of the band gap. Another possibility involves vaporising the dopants such as for example silicon, germanium, magnesium or iron as pure melts, or sublimating the respective solid. A further temperature zone or a separately heated crucible in the reactor is required for that purpose. In most cases, similarly to the gallium-bearing melt, that crucible also has to be protected from nitriding.
[0064] The growing crystal 112 or the reactor chamber in the upper part thereof are heated to a temperature T 2 which is at about 1000° C. and which is effected for example by heating of the reactor wall by means of an externally disposed resistance heater (not shown) or a lamp heating means (also not shown). In the lower region of the reactor chamber 102 it is recommended that the reactor wall is heated to a similar or somewhat higher temperature like the temperature of the melting crucible (T 1 ) in order to prevent excessively severe deposit of gallium on the reactor wall.
[0065] The growth speed in various crystal directions can be increased or inhibited as required by the gas composition, that is to say the ratio of for example H 2 , N 2 , as well as the nitrogen precursor, and by the growth temperature and the reactor pressure, so that it is possible to achieve specific crystal orientations and crystal shapes.
[0066] By way of example a thin GaN layer on a foreign substrate serves as the seed crystal. Dislocations are increasingly reduced in the course of the growth of a thicker crystal. The growing crystal can be rotated (indicated by the double-headed arrow 122 ) to increase the homogeneity of growth and should be pulled upwardly with increasing thickness in order to keep the growth conditions at the growth front 118 at the lower end of the crystal always the same.
[0067] If very long crystals are to be pulled, it is recommended that the crystal should not be greatly cooled at the upper end when the crystal is being pulled upwardly in order to avoid stresses which can lead to dislocations and cracks. That can be implemented by the reactor or the gas outlet 120 being of a suitably long configuration and by heating of the region in question.
[0068] An advantage of the hanging structure of the crystal holder 114 , as shown in FIG. 1 , is the avoidance of parasitic depositions on the crystal 112 . When other geometries are involved, falling deposits which occur on the reactor walls can give rise to parasitic depositions of that kind.
[0069] The material of the reactor chamber can be for example quartz glass. When quartz glass is used however the growing layer on the reactor wall also tears away the glass, which entails complete destruction of the reactor. The deposits however can be reduced by the introduction of the inert gases or hydrogen along the reactor wall. What is preferred in relation to quartz glass however is the use of boron nitride (BN) as that material makes it possible to remove deposits without destruction of the boron nitride.
[0070] Above all boron nitride is also ideally suited as the material for the melting crucible A because it can be produced at a high level of purity, it is stabilised by the nitrogen precursor and causes only little trouble as a trace impurity in the resulting GaN or AlGaN single crystals. Alternatively however it is also possible to use any other high temperature-resistant material which does not decompose at the temperatures and gas atmospheres used. Besides quartz glass that is also the materials tantalum carbide TaC, silicon carbide SiC and carbon C. When using graphite in a hydrogen atmosphere, a coating with silicon carbide SiC is recommended.
[0071] In the embodiment of FIG. 1 residual gases issue at the upper end of the reactor where a pump (not shown) can be mounted to produce a reduced pressure or a controllable throttle valve (also not shown) can be mounted to produce an increased pressure.
[0072] FIG. 2 shows a first variant of a melting crucible 200 for use in the reactor arrangement of FIG. 1 instead of the melting crucible A. Apart from the carrier gas feeds 206 . 1 and 206 . 2 and a carrier gas outlet opening 222 the melting crucible 200 is closed on all sides. Unlike the embodiment of FIG. 1 therefore in this case the carrier gas feeds 206 . 1 and 206 . 2 are passed directly into the melting crucible 200 . A volume for providing a vertical gas flow, indicated by arrows 226 and 228 , is afforded above the surface 224 of the metal melt, by virtue of the melting crucible 200 being of an elongate configuration. The very substantially closed configuration of the melting crucible 200 promotes the avoidance of pre-reactions of the nitrogen precursor (for example ammonia) with the melting melt. The resulting limitation of the gas flow to the diameter of the melting crucible 200 gives rise to a high flow speed for the carrier gas flow which counteracts diffusion of the nitrogen precursor into the melt still more efficiently than the example shown in FIG. 1 . At the same time the increased flow speed provides for efficient transport of the gallium vapour into the reactor chamber.
[0073] In principle it would also be possible to provide solely for an elongate configuration for the melting crucible and not to provide a separate cover in an upward direction. However that variant would not be as efficient as the reduction in the diameter of the outlet opening, as shown in FIG. 2 .
[0074] The embodiment of FIG. 2 shows the crucible 200 with the carrier gas feeds 206 . 1 and 206 . 2 as well as the lines of a high frequency heating means 204 . When such a crucible structure is adopted it is advantageous for the upper portions of the wall to be kept at the same temperature as or at a higher temperature than the temperature of the melt. That can be effected for example by using an induction heating means by virtue of a suitable configuration for the coils and thus the high frequency field or by an additional resistance heating means.
[0075] FIG. 3 shows a variant of a melting crucible 300 which shows an implementation of that concept. The melting crucible 300 is the same as the melting crucible 200 except for the differences referred to hereinafter. Instead of the opening 222 , there is a thin outlet tube 322 at the upper end of the melting crucible, through which the gallium vapour issues with the flushing gas. A heating means 326 surrounds the outlet tube 322 . To avoid deposits and to reduce the risk of gallium droplet formation in the gas flow, the wall of the outlet tube 322 should be heated to a temperature T 2 >T 1 .
[0076] FIG. 4 shows a further variant in the form of a melting crucible 400 in which a feed 406 for the carrier gas is implemented through an opening 422 provided at the top side of the melting crucible. The melting crucible is otherwise the same as the melting crucible 200 in FIG. 2 . The carrier gas feed shown in FIG. 4 also produces a gas flow which is passed directly over the surface 424 of the metal melt, is then guided upwardly together with the issuing gallium vapour and is passed out of the outlet opening 422 in the direction of the reaction region. There is accordingly no need for the carrier or flushing gas to be introduced in parallel relationship with the surface 424 of the metal melt in order to prevent contact of the surface thereof with the nitrogen precursor. Introduction in perpendicular relationship to the surface achieves the same effect.
[0077] FIG. 5 shows as a further variant a melting crucible 500 which combines together the characteristics of the melting crucibles 300 and 400 (see FIGS. 3 and 4 ). In this embodiment the carrier gas is introduced by way of a carrier gas feed 506 at the top side 528 of the melting crucible 500 . Accordingly the gas flow firstly faces downwardly as in the example of FIG. 4 , then impinges against the metal surface 524 in order from there to rise upwardly together with the issuing metal vapour and to be passed into the reactor chamber through an outlet tube 522 .
[0078] FIG. 6 shows a further variant of a melting crucible 600 in which the outlet tube 622 is increased in width in order to also accommodate the carrier gas feed 606 .
[0079] FIG. 7 shows a further variant of a melting crucible 700 in which a tubular heating means 730 is used instead of a high frequency heating means. Otherwise the structure of the melting crucible is the same as that shown in FIG. 2 .
[0080] FIG. 8 shows a further variant in the form of a melting crucible 800 in which, similarly to the case with the embodiment shown in FIG. 4 , the carrier gas feed 806 is passed through the outlet opening 822 at the top side of the melting crucible. A tubular heating means 830 is used similarly to the case with the embodiment of FIG. 7 .
[0081] In the case of the melting crucibles in FIGS. 4 , 5 , 6 and 8 in an alternative configuration the carrier gas feed can be passed into the metal melt so that the carrier gas rises in bubble form in the metal melt and issues from the metal melt. That embodiment can also be combined with those described hereinbefore so that both a carrier gas flow can be passed on to the surface of the metal melt and can also be passed thereinto.
[0082] FIG. 9 shows an alternative configuration of a reactor chamber 900 . The difference in relation to the reactor chamber 100 in FIG. 1 is that this is a horizontal arrangement. The melting crucible A and the carrier gas feed 906 are arranged in a corresponding fashion. In this case also only one carrier gas line is also sufficient as the horizontal gas flow, after having been passed over the surface of the metal melt in the melting crucible A, is further guided in the direction of the growing crystal 912 on to the growth surface 918 thereof. In this embodiment the feed of the precursor gas is in a vertical direction through precursor feed lines 910 . 1 and 910 . 2 . In other respects the mode of operation of the reactor arrangement 900 is similar to that described with reference to FIG. 1 .
[0083] It will be appreciated that the process according to the invention can also be used for the production of polycrystalline crystals.
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The invention concerns a process and an apparatus for the production of gallium nitride or gallium aluminium nitride single crystals. It is essential for the process implementation according to the invention that the vaporisation of gallium or gallium and aluminium is effected at a temperature above the temperature of the growing crystal but at least at 1000° C. and that a gas flow comprising nitrogen gas, hydrogen gas, inert gas or a combination of said gases is passed over the surface of the metal melt in such a way that the gas flow over the surface of the metal melt prevents contact of the nitrogen precursor with the metal melt.
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FIELD OF THE INVENTION
[0001] The present invention relates to a printhead maintenance cap for use with an electrostatic printhead.
BACKGROUND
[0002] The general method of operation of the type of printhead described in WO 93/11866 is well known, wherein an agglomeration or concentration of particles is achieved in the printhead, and, at the ejection location, the agglomeration of particles is then ejected on to a substrate. In the case of an array printer, plural ejection locations may be arranged in one or more rows.
[0003] Electrostatic printers of this type eject charged solid particles dispersed in a chemically inert, insulating carrier fluid by using an applied electric field to first concentrate and then eject the solid particles. Concentration occurs because the applied electric field causes electrophoresis and the charged particles move in the electric field towards the substrate until they encounter the surface of the ink. Ejection occurs when the applied electric field creates an electrophoretic force that is large enough to overcome the surface tension. The electric field is generated by creating a potential difference between the ejection location and the substrate; this is achieved by applying voltages to electrodes at and/or surrounding the ejection location.
[0004] The location from which ejection occurs is determined by the printhead geometry and the location and shape of the electrodes that create the electric field. Typically, a printhead consists of one or more protrusions from the body of the printhead and these protrusions (also known as ejection upstands) have electrodes on their surface. The polarity of the bias applied to the electrodes is the same as the polarity of the charged particle so that the direction of the electrophoretic force is away from the electrodes and towards the substrate. Further, the overall geometry of the printhead structure and the position of the electrodes are designed such that concentration and then ejection occurs at a highly localised region around the tip of the protrusions.
[0005] The ink is arranged to flow past the ejection location continuously in order to replenish the particles that have been ejected. To enable this flow the ink must be of a low viscosity, typically a few centipoises. The material that is ejected is more viscous because of the higher concentration of particles due to selective ejection of the charged particles; as a result, the technology can be used to print onto non-absorbing substrates because the material will not spread significantly upon impact.
[0006] Various printhead designs have been described in the prior art, such as those in WO 93/11866, WO 97/27058, WO 97/27056, WO 98/32609, WO 98/42515, WO 01/30576 and WO 03/101741.
[0007] In use, printheads will, at some stage, require cleaning for one or more of various reasons including removing agglomerations of ink particles from the ejection tips of the printhead or removing airborne particles from the ejection tips or intermediate electrode (IE). All previous printheads and cleaning methods were such that the cleaning was carried out by replacing all of the ink within the printhead with rinse fluid.
[0008] Such a design and process that involves replacing the ink within the printhead with rinse fluid leads to various problems. Firstly, cleaning the printhead by flushing through the ink path with rinse fluid creates a large amount of ink-rinse mixture which dilutes the ink and/or contaminates the rinse which must be filtered or discarded. It also requires the printhead to be re-primed with ink after cleaning, requiring significant time for the ink concentration to stabilise as the rinse is replaced with ink. This further causes dilution of the ink and/or mixing of a quantity of ink into the rinse, which has to be filtered out to clean the rinse.
[0009] Additionally, such a process is time consuming and, in particular when it is desired to carry out cleaning periodically to keep ejectors and intermediate electrode suitably clean to maintain good print performance for the printhead, it is desired to minimise the downtime of the printhead.
[0010] Thus the present invention is directed to reducing or avoiding entirely one or more of the problems identified above.
[0011] It has been recognised that cleaning of the ejection tips and if provided the intermediate electrode is usually sufficient to maintain print performance, and that other structures within the printhead do not require regular cleaning in operation.
[0012] According to the present invention, there is provided a method of cleaning an electrostatic printhead which has one or more ejection tips from which, in use, ink is ejected, the method comprising stopping a prior flow of ink to a region around the ejection tip(s) for, in use, printing, causing a pressure differential to occur at the tip region thereby causing the ink meniscus to retreat from the tip, and passing a rinse into the tip region to clean the tip.
[0013] Such method allows the tips to be free, or substantially free, of ink when the rinse is supplied. This ensures that the amount of ink wasted and/or rinse fluid that is required is minimised, as there are fewer regions through or across which the rinse is flowed and these regions are not filled with ink when the rinse is supplied.
[0014] One advantage of the invention is that the printhead is kept primed with ink during cleaning. Preferably, dedicated passages in the printhead direct rinse fluid and air to the tip-IE (intermediate electrode) cavity of the printhead, which is cleaned with very little mixing of rinse with ink. Ink flow around the tips is preferably stopped but the printhead remains full of ink. Air pressure in the tip region is preferably raised so that the ink meniscus retreats slightly from the tip region, exposing the tips for cleaning. Rinse may then be directed at the inside faces of the IEs from the dedicated passages within the printhead body, resulting in the cleaning of the inside face of the IEs and the tips. Rinse flow is preferably pulsed in short bursts, which helps to reduce the amount of rinse that enters the ink channels. The rinse preferably then drains into a maintenance cap sealed onto the face of the printhead during maintenance.
[0015] By using separate passages to introduce cleaning fluids to the printhead tips and IE, and by withdrawing the ink from the tips but not from the rest of the printhead, prime is maintained and cross-contamination of rinse and ink is minimised; by pulsing the flow of rinse into the printhead, alternating with air, the rinse does not flow up the ink channels significantly; by making repriming unnecessary the cleaning cycle is dramatically shortened and waste is reduced.
[0016] The ink preferably remains in the body of the printhead during the cleaning of the tips. This means that re-priming of the printhead after cleaning is therefore faster, as the ink only needs to be moved forward towards the tips rather than refilling the entire printhead. The “body of the printhead” essentially means the parts of the printhead of significant volume which would, in the normal course of operation contain ink. This includes the inlet and outlet manifolds, and typically it means that there is still ink at the base of the ink channels which connect to the respective ejection tips.
[0017] The method may further comprise the step of pulsing the flow of rinse. The pulsing may include alternating pulses of rinse and air. The pulsing may comprise pulses of air and rinse combined. The pulsing may comprise injecting rinse into an airflow. The pulsing may include air pulses, and pulses of air and rinse combined.
[0018] The air/rinse pulse is preferably 50% longer than the air pulse. The air/rinse pulse is typically 3 seconds. The air pulse is typically 2 seconds.
[0019] The printhead preferably comprises an intermediate electrode and the rinse is preferably directed at an inside face of the intermediate electrode.
[0020] The pressure differential required is preferably formed between the ink in the body of the printhead, and the atmosphere at the tip.
[0021] The pressure differential may be caused by applying a localised increase in atmospheric pressure at the tip.
[0022] The increase in atmospheric pressure at the tip may be caused by flowing air and/or rinse into the tip region.
[0023] The pressure differential may be caused by reducing the ink pressure in the body of the printhead.
[0024] The present invention also provides an electrostatic printhead comprising a main body including an inlet for ink, an array of one of more ejection tips from which in use ink can be ejected from the main body, respective channels through the main body for supplying ink to, and taking ink away from, the tips, and at least one dedicated passage extending through the main body to the ejection tips for the supply of a rinse fluid to clean the tips.
[0025] The printhead may include a datum plate having a cavity that surrounds the ejection tips, wherein the cavity is v-shaped.
[0026] The main body may also include an inflow and outflow block through which ink passes.
[0027] The angle of the “V” preferably matches a corresponding feature on the inflow and outflow block, thereby defining one or more parallel-sided fluid pathways.
[0028] A seal may be provided between the datum plate and the inflow and outflow block.
[0029] Also provided is a maintenance cap which can provide one of more of the following advantages: (i) catch and drain rinse fluid expelled from the printhead, (ii) assist in cleaning the front face of the printhead, (iii) allow the printhead to remain filled with ink during cleaning of the tips and IE, and (iv) cannot be inserted or withdrawn erroneously while clamped to the printhead.
[0030] According to the present invention, there is provided a printhead maintenance cap for attachment to a printhead, the cap comprising: a main body defining a chamber into which rinse fluid passes from the printhead during a cleaning cycle; a seal for engagement with the printhead prior to a cleaning cycle starting; and a venting system for equalising the pressure in the chamber and the surrounding atmosphere.
[0031] The printhead to which the maintenance cap is attached, in use, is may be an electrostatic printhead. The terms “maintenance cap” and “cleaning cap” are synonymous. Whilst cleaning is the preferred purpose for the cap, other tasks are also envisaged
[0032] The printhead maintenance cap may further comprise means for, in use, bringing the seal into engagement with the printhead. The engagement means includes a clamp and/or a pneumatically operated mechanism.
[0033] The venting system may include one or more baffles. The one or more baffles may be formed from a single piece component formed by stereolithography or a three-dimensional printing technique.
[0034] The printhead maintenance cap may further comprise one or more drains for draining fluid from the cap in use. This has particular benefit as it allows the cap to be used in a range of orientations, especially when more than one drain is provided.
[0035] One or more additional seals may be provided to permit the cap to be used with a multi-head printhead.
[0036] The printhead maintenance cap may further comprise a movable spray head for providing one or more jets of rinse fluid within the cap.
[0037] A drive mechanism for moving the cap into and out of engagement with the printhead may be provided. This may be part of the engagement means of the printhead maintenance cap or may be separate.
[0038] The printhead maintenance cap may further comprise an interlock for preventing movement of the cap when in a sealed engagement with the printhead.
[0039] The printhead maintenance cap may further comprise a vacuum wiper. The vacuum wiper may be pivotable relative to the cap main body. The vacuum wiper may be biased towards the intended location of the printhead.
[0040] The invention also provides an electrostatic printhead having a plurality of ejection tips and an intermediate electrode, the printhead further comprising a maintenance cap as described above.
[0041] In the printhead, the vacuum wiper preferably does not contact the intermediate electrode.
[0042] Previous maintenance caps:
were not vented so draining fluid out of the maintenance cap could draw fluid out of the printhead or de-prime the printhead, necessitating prior removal of ink from the printhead. did not seal to the intermediate electrode, but to the printhead casework which would therefore become wet internally during cleaning and necessitate a prolonged drying period. had no protection against erroneous insertion or withdrawal of the unit while in the clamped state.
DESCRIPTION OF THE DRAWINGS
[0046] Various embodiments of the invention will now be described with reference to the attached figures in which:
[0047] FIG. 1 is a perspective view of a printhead according to the present invention;
[0048] FIG. 2 is an exploded view of the printhead illustrated in FIG. 1 ;
[0049] FIG. 3 is a sectional view of a manifold block that directs cleaning fluids to different parts of the printhead;
[0050] FIG. 4 is a sectional view in of the printhead showing the passages that direct cleaning fluids to the tip region of the printhead;
[0051] FIG. 5 is a detailed cross-sectional view of the ejection region of the printhead illustrated in FIG. 1
[0052] FIG. 6 is a three-dimensional close-up illustration of the ejection region of the printhead illustrated in FIG. 1
[0053] FIG. 7 is the same view as FIG. 4 , but with fluid flow paths indicated;
[0054] FIG. 8 shows one example of a maintenance cap for use in the cleaning method;
[0055] FIG. 9 shows an end view of the maintenance cap of FIG. 8 , and the various fluid connections;
[0056] FIG. 10 shows a schematic view of some of the internal components of the maintenance cap;
[0057] FIGS. 11A and 11B show one arrangement of baffles in the venting system on the maintenance cap;
[0058] FIG. 12 shows an example of a printhead module outer casing with which the maintenance cap engages; and
[0059] FIG. 13 is a flow chart describing the stages of the cleaning process.
DESCRIPTION OF THE PREFERRED EMBODIMENT
[0060] The printhead 100 of the present invention comprises a two-part main body consisting of an inflow block 101 and an outflow block 102 , between which are located a prism 202 and a central tile 201 , the latter having the ejector array formed along its front edge. At the front of the printhead, an intermediate electrode plate 103 is mounted on to a datum plate 104 , which in turn is mounted onto the main body of the printhead. A gasket 208 is provided between the datum plate 104 and the inflow and outflow blocks.
[0061] Referring to FIGS. 2, 3, 4, 5 and 6 , the main body of the printhead comprises the inflow block 101 and the outflow block 102 , sandwiched between which are the prism 202 and the central tile 201 . The central tile 201 has an array of ejection locations or tips 403 along its front edge and an array of electrical connections 203 along its rear edge. Each ejection location 403 comprises an upstand 400 with which an ink meniscus interacts (in a manner well known in the art). On either side of the upstand 400 is an ink channel 404 that carries ink past both sides of the ejection upstand 400 . In use, a proportion of ink is ejected from the ejection locations 403 to form, for example, the pixels of a printed image. The ejection of ink from the ejection locations 403 by the application of electrostatic forces is well understood by those of skill in the art and will not be described further herein.
[0062] The prism 202 comprises a series of narrow channels 411 , corresponding to each of the individual ejection locations 403 in the central tile 201 . The ink channels of each ejection location 403 are in fluid communication with the respective channels of the prism 202 , which are, in turn, in fluid communication with a front portion 407 of the inlet manifold formed in the inflow block 101 (said inlet manifold being formed on the underside of the inflow block 101 as it is presented in FIG. 2 and thus not shown in that view). On the other side of the ejection locations 403 , the ink channels 404 merge into a single channel 412 per ejection location 403 and extend away from the ejection locations 403 on the underside (as drawn in FIG. 5 ) of the central tile 201 to a point where they become in fluid communication with a front portion 409 of the outlet manifold 209 formed in the outflow block 102 .
[0063] The ink is supplied to the ejection locations 403 by means of an ink supply tube 220 in the printhead 100 which feeds ink into the inlet manifold within the inflow block 101 . The ink passes through the inlet manifold and from there through the channels 411 of the prism 202 to the ejection locations 403 on the central tile 201 . Surplus ink that is not ejected from the ejection locations 403 in use then flows along the ink channels 412 of the central tile 201 into the outlet manifold 209 in the outflow block 102 . The ink leaves the outlet manifold 209 through an ink return tube 221 and passes back into the bulk ink supply.
[0064] The channels 411 of the prism 202 which are connected to the individual ejection locations 403 are supplied with ink from the inlet manifold at a precise pressure in order to maintain accurately controlled ejection characteristics at the individual ejection locations 403 . The pressure of the ink supplied to each individual channel 411 of the prism 202 by the ink inlet manifold is equal across the entire width of the array of ejection locations 403 of the printhead 100 . Similarly, the pressure of the ink returning from each individual channel 412 of the central tile 201 to the outlet manifold 209 is equal across the entire width of the array of ejection locations 403 and precisely controlled at the outlet, because the inlet and the outlet ink pressures together determine the quiescent pressure of ink at each ejection location 403 .
[0065] The printhead 100 is also provided with an upper 204 and a lower 205 cleaning fluid manifold. The upper and lower cleaning fluid manifolds have respective inlets 105 a, 105 b through which rinse/cleaning fluid can be supplied to the printhead 100 . The inflow 101 and outflow 102 blocks are both provided with cleaning fluid passages 401 . The passages in the inflow block 101 are in fluid communication with upper cleaning fluid manifold 204 and those passages in the outflow block 102 are in fluid communication with the lower cleaning fluid manifold 205 . Fluid connectors 206 link the cleaning fluid manifolds to the respective cleaning fluid passages.
[0066] The cleaning fluid passages 401 within the inflow and outflow blocks end at cleaning fluid outlets 207 . The pathway to the ejection locations 403 continues along enclosed spaces 405 defined by the V-shaped cavity 402 in the datum plate 104 and the outer surfaces of the inflow 101 and outflow 102 blocks, until the point at which the ejection locations 403 themselves lie within the cavity 402 . The two sides of the V-shaped cavity are, in this example, at 90 degrees to each other.
[0067] As can be seen in FIG. 7 , arrows A show the fluid pathways taken by the rinse/cleaning fluid and/or air during cleaning of the printhead. Regions B show the pathways taken by the ink through the inlet and outlet manifolds and along ink channels 411 and 412 . During normal operation a flow of ink exists around the tips 403 from the inlet side (inlet block 201 ) to the outlet side (outflow block 202 ). In normal use, there is no flow of cleaning fluid—indeed no cleaning fluid is present in the printhead. However, during a cleaning operation, ink flow is stopped and the ink is withdrawn slightly from the tips to the position indicated above and in FIG. 7 , as described below. This withdrawal of the ink means that, when cleaning fluid is supplied through passages 401 and into cavity 402 , the cleaning fluid does not mix substantially with the ink in the printhead, but can clean the tips 403 . When cleaning is complete, the printhead can be primed easily by moving the ink back to the ejection locations 403 so that it can resume a constant flow around the ejection locations 403 from the inflow to the outflow side of the printhead.
[0068] An example of a maintenance cap that can be used during cleaning of the ejection tips is shown in FIGS. 8 to 10 .
[0069] The maintenance cap 800 includes a printhead engaging section 801 and an engagement section 802 , which in this example is a clamping engagement. The printhead engaging section 801 includes a base section 803 and upstanding side walls 804 . The side walls include linear key way bearings 805 which engage with a corresponding profile 902 on a printhead module outer casing 901 ( FIG. 12 ). The side walls could be replaced with, or used together with, other means of mounting the cap 800 on the printhead. This is especially true, if multiple printheads are provided and the same cap is used to cover more than one of the printheads at the same time. The cap may also provided with a fitting handle 814 to help with the initial installation of the cap in the printer (although thereafter the cap is controlled automatically).
[0070] The base section 803 includes a tank 806 on which a printhead seal 807 is mounted. The tank has an opening 808 into which, in use, rinse fluid is drained from the printhead through the slot in the IE 103 , the opening defining a cavity within the tank 806 . The opening 808 is surrounded by the seal 807 . In the figures, the printhead to be cleaned is placed above the tank, in engagement with the seal 807 . Beneath the seal 807 , on the opposite side of the opening 808 , a movable spray head 809 is provided, mounted on a pair of spray head guides 810 (one is visible in FIG. 10 ). The function of the spray head 809 is to clean the outer face of the IE 103 by directing fine jets of rinse fluid thereon.
[0071] In operation, the maintenance cap is inserted across the front of the printhead and clamped or otherwise fastened against the outer face of the intermediate electrode forming a fluid-tight seal. The printhead ink pathways remain filled with ink during the cleaning process, except for the very tip region as the ink is caused to retreat from tips by a pressure differential at the tips. The cleaning action is therefore confined to the tip-IE region of the printhead. The cap collects and drains rinse fluid from the printhead during a cleaning operation, the fluid preferably being drained to a tank in the fluid management system remote from and lower than the printhead. Because of the seal, the draining action from the maintenance cap could create a partial vacuum in the maintenance cap that would draw the ink out of the printhead. A further preferred feature is a baffled venting system, see FIG. 11 , which can prevent this. The system includes one or more, in this case two, air vents 813 , and these vents allow equalisation of air pressure between the inside of the maintenance cap and the surrounding atmosphere, and prevents the escape of rinse fluid through the vent by incorporating a series of baffles 843 , 844 .
[0072] The maintenance cap, in a preferred embodiment, has a pneumatically actuated clamp to clamp to the face of the intermediate electrode. This is preferably achieved using a pair of bidirectional pin cylinder actuators 811 acting directly on a pair of cam strips 812 , which are moved, longitudinally in this example, to cause the upward clamping motion of the maintenance cap base section 803 to the printhead. The cylinders 811 are pneumatically driven in parallel from switched compressed air sources that connect to two pneumatic connectors respectively as shown in FIG. 9 : seal-unclamp 818 and seal-clamp 819 .
[0073] When sealed to the printhead, it is important that no attempt is made to withdraw the cap, causing it to rub across the printhead, potentially damaging the seal, the drive, or the printhead itself. Similarly the cap must not be inserted across the face of the printhead while in a clamped state. To guard against these eventualities, the coupling of the cap to a linear drive mechanism (not shown) that inserts and withdraws the cap is preferably interlocked to the clamp state of the cap, by use of a third pneumatic pin cylinder 815 that may be fed from the same switched compressed air source as the cylinders 811 that actuate the clamping mechanism. The cylinder 815 engages the drive with the cap when the cap is unclamped and disengages it when clamped, thereby interlocking the cap drive to the clamp state. In the example shown, the linear drive mechanism is continuously engaged with the drive engagement block 816 via four drive engagement pins 817 , which locate in the moving part of the linear drive mechanism. When actuated, the pin of the cylinder 815 locates into the socket of the drive engagement block 816 . In this state, the entire maintenance cap is coupled to the linear drive for insertion and withdrawal under the printhead. The switched compressed air source that actuates the cylinder 815 is the same source that actuates the unclamped state of the clamping cylinders 811 , these all being linked by pneumatic tubing to the seal-unclamp pneumatic connector 818 . Hence, when the unclamped state is actuated, the linear drive mechanism engages with the entire cap assembly.
[0074] When in the clamped state, the linear drive mechanism engages with the moveable spray head 809 only. The spray head 809 is moveable along the length of the opening 808 , its motion guided centrally by the guides 810 . Rinse fluid is supplied to the spray head via a rigid tube 830 that connects the spray head with the spray head connection 831 . The tube 830 also mechanically couples the spray head 809 to the drive engagement block 816 , the tube 830 passing through an O-ring seal in the tank wall that allows movement of the tube through the seal without losing fluid from the tank 806 . When in the clamped state, the spray head 809 may thereby be moved along the length of the printhead spraying rinse, air, or a mixture thereof, when required by the cleaning operation.
[0075] Vacuum Wiper
[0076] In a preferred embodiment a vacuum wiper 820 is located at one end of the base section 803 . The vacuum wiper 820 comprises a narrow slot 821 in the upper face of a wiper body 822 which is in fluid communication via a pair of tubes 810 (rigid tubes that also act as the spray head guides in this example) and connectors 823 to a pair of vacuum wiper connections 825 via short lengths of flexible tubing (not shown). The wiper body is pivoted at its point of attachment to the base section 803 and is sprung upwards towards the printhead. Two rollers 824 attached to the wiper body 822 roll against the face of the printhead several millimetres either side of the ejection region as the maintenance cap is inserted or withdrawn, the rollers serving to control the spacing between the wiper slot and the face of the IE to approximately 0.2 mm. When the connections 825 are connected to a source of vacuum, air is drawn into the slot 821 . Applying vacuum in this way as the maintenance cap is withdrawn from the printhead after a cleaning operation draws any drips or residual rinse fluid from the face of the IE into the wiper and may be used to dry the outer face of the IE. It has been found to be more effective at drying the IE than a conventional wiper because the vacuum will draw fluid out of the slot between the two blades of the IE more effectively. The vacuum wiper described above also has no rubbing contact with the IE, and therefore minimises the risk of wearing or otherwise damaging the precision IE component, or of pushing foreign material into the IE slot.
[0077] Baffle System
[0078] Fluid that enters the tank 806 is drained from one or both cap drain connectors 832 . The provision of two cap drains allows the cap to be employed on printheads mounted in a variety of orientations, in each case the lower of the two drains is used and the upper one is plugged. The cap drain connectors 832 are mounted in a baffled venting block 840 , which allows equalisation of air pressure between the inside of the maintenance cap and the surrounding atmosphere while preventing the escape of rinse fluid through the vents 813 by incorporating a series of internal baffles 843 , 844 . The venting block comprises a hollow body 842 with two downward projecting sections, one on each side. Each of these has at its base a channel 845 that carries rinse fluid that drains from the cap back to a tank in the remote fluid management system. The channels 845 are open to the hollow interior of the venting block within which a series of downward-sloping baffles 843 , 844 inhibit the passage of rinse up through the body 842 from splashing, etc, while allowing air to pass between the vents 813 and the channels 845 . The combination of rinse and air used in the printhead cleaning process is such that the flow of rinse from the tank 806 to the venting block 840 along short tubes (not shown) connecting the tank drains 834 to the venting block inlets 833 is discontinuous, allowing sufficient passage of air between the venting block 840 and the tank 806 to maintain pressure in the tank 806 close to that of the surrounding atmosphere. Furthermore, when the printhead and cap are operated in an orientation other than vertical, the higher of the two channels 845 will generally be free of rinse and will serve as a continuous air connection with the tank 806 to maintain atmospheric pressure therein.
[0079] The maintenance cap described above is capable of operating vertically as depicted in FIGS. 8 to 10 or at any angle θ as indicated in FIG. 9 of up to ±75 degrees from vertical, and so is suitable for use in printing machines in which the printheads are mounted in this range of orientations.
[0080] Description of the one example of the cleaning process is shown in FIG. 13 and is described as follows:
[0081] 1. START: When a printhead cleaning operation is called for, either through automatic scheduling or operator intervention, printing is stopped, the printhead moved away from the substrate (or the substrate moved depending on the type of printer), and a maintenance cap, such as that described in FIGS. 8 to 10 , presented to the face of the printhead.
[0082] 2. The maintenance cap is sealed to the face of the printhead.
[0083] 3. Ink flow around the printhead—a constant feature of the printhead in its normal operating state, controlled by difference in ink pressures between the inlet and outlet ports of the printhead—is stopped by setting equal pressures at the inlet and outlet ports, at the mid-point of the normal operating pressures.
[0084] 4. Air under slight positive pressure is supplied to the cleaning fluid inlets 105 a and 105 b via an external control valve. The air passes through the upper and lower cleaning fluid manifolds 204 , 205 , where it is distributed via fluid connectors 206 to eight passages 401 spaced evenly across the width of the printhead: four on the upper side and four on the lower side. It emerges from cleaning fluid outlets 207 into the cavity 402 near the front of the printhead in close proximity to the ejection tips 403 and the inner face of the intermediate electrode 103 . The air pressure near the tips is slightly higher than that of the atmosphere external to the printhead or in the maintenance cap because the narrow slot in the IE presents a restriction to the flow of air out of the printhead. The higher air pressure is not sufficient to force the ink backwards out of the printhead, but causes it to retreat from the tip region enough to expose the ejection tips 403 .
[0085] 5. A rinse-air mixture is periodically directed through the cleaning fluid passages 401 in short bursts, controlled via an external control valve. Typical timings are: air 2 s; rinse & air 3 s; air 2 s; rinse & air 3 s; air 2 s; rinse & air 3 s; air 2 s. The timings have been found to provide effective cleaning whilst minimising the amount of rinse that enters the ink channels. Rinse fluid flows from the cavity 402 through the open slot in the centre of the intermediate electrode 103 into the maintenance cap from where it is drained.
[0086] 6. Air is turned off and the maintenance cap released, allowing a wiper to be drawn across the outside face of the intermediate electrode 103 to remove any drips. The cap is re-sealed to the printhead.
[0087] 7. The air supply is turned on again to start drying the internal faces of the printhead. Air flows through the spaces 405 and the cavity 402 and into the maintenance cap from where it is vented.
[0088] 8. Ink flow around the printhead is re-established by raising the ink pressures to bring the ink forwards to the tips again and setting a pressure difference between the inlet and outlet ports of the printhead. Flow is established in the forward direction (inlet to outlet) for 30 s, then reversed by swapping the pressures at the inlet and outlet ports, which has the effect of expelling any air trapped in the ink channels from the cleaning process.
[0089] 9. In this state, the maintenance cap is released again and the outside face of the intermediate electrode wiped again to remove residual drips of rinse, and the maintenance cap withdrawn completely from the printhead.
[0090] 10. There follows a further drying phase of 150 s in total, after 120 s of which the ink flow is restored to the forward direction. The air is then turned off.
[0091] 11. The pressures are controlled such that the ink pressure at the tips is just below that of the atmosphere surrounding the tips so that the ink flow is confined in the channels 404 each side of the ejection tips and the ink meniscus pins to the tips and edges of the channels 404 .
[0092] 12. END The whole sequence is complete in under 5 minutes, around a quarter that of earlier methods.
[0093] It will be appreciated that many of the steps described above are not essential to the invention as described—indeed, the present invention is defined in the broadest terms by the claims filed herewith.
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A printhead maintenance cap for attachment to a printhead, the cap comprising: a main body defining a chamber into which rinse fluid passes from the printhead during a cleaning cycle; a seal for engagement with the printhead prior to a cleaning cycle starting; and a venting system for equalising the pressure in the chamber and the surrounding atmosphere.
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CROSS REFERENCE TO RELATED APPLICATIONS
[0001] This application is a continuation of, and claims priority under 35 U.S.C. §120 to, PCT Application No. PCT/DE2010/000316, filed on Mar. 23, 2010, which claimed priority to German Application No. 20 2009 004 014, filed on Mar. 25, 2009. The contents of both of these priority applications are hereby incorporated by reference in their entirety.
TECHNICAL FIELD
[0002] The present invention relates to punching tools and related machines and methods.
BACKGROUND
[0003] The main components of a punching tool typically include a punching stamp and an adjustment ring. The adjustment ring is typically used to retain the punching tool in a tool retention member of a machine tool (e.g., a punching machine). A punching tool can refer not only to a tool used for conventional punching processes, but also to tools that are suitable for other workpiece processing operations (e.g., shaping, embossing, molding, and other operations).
[0004] There are various types of punching stamps that are adapted for use in various different material processing operations. Accordingly, there are also various types of adjustment rings that are adapted to different stamp shaft configurations of punching stamps and are intended to adapt the punching tools to various machine retention members of machine tools. However, due to the various types and configurations of adjustment rings and punching stamps that are available, incompatible combinations of adjustment rings and punching stamps can be inadvertently assembled.
[0005] Generally, two types of stamps with different stamp shaft configurations are used. One type of stamp includes an axial stop that is constructed as a planar face. Another type of stamp includes an axial stop that is constructed in a stepped manner and has at least one step. For the stamp shaft configuration having a planar face axial stop, an adjustment ring with a corresponding planar lower side is typically suitable. For the stamp shaft configuration having a stepped axial stop, an adjustment ring with a corresponding stepped lower side is typically suitable. The total thicknesses of the adjustment rings used with each type of axial stop are generally the same. If an adjustment ring with a planar lower side is used with a stamp having a stepped axial stop to produce the punching tool, the adjustment ring typically sits too high on the stamp shaft. As a result, the punching tool typically does not properly fit into a stamp receiving member of a machine retention member on a machine tool, and, therefore, the machine tool is not operational.
[0006] Due to the incorrect assembly, when replacing a punching tool using a tool changing device on a machine tool, a collision may occur if the machine tool does not have a stamp height monitoring system. Although, in machine tools having a stamp height monitoring system, an error message typically occurs in the event of incorrect stamp height, the stamp height is first checked using the machine tool, which leads to, at the very least, a disruption of production and potentially a program abortion with a subsequent restart. In a worst case, the incorrect height can lead to the separation of the workpiece that has just been processed, which results in a reject. The punching tool is typically also removed from the machine tool so that the adjustment ring can be replaced and aligned.
[0007] DE 100 32 045 C2 discloses a punching tool including a punching stamp that can be secured in an adjustment ring, a wedge that is provided to prevent rotation in a tool retention member, and a rotation prevention member between the stamping punch and the adjustment ring. The rotation prevention member is secured to the wedge in a positive-locking manner at the side of the adjustment ring in the direction of rotation.
[0008] DE 10 2006 002 547 A1 discloses a punching tool (e.g., for punching machines) having tool changing devices in which the punching stamp and the adjustment ring are arranged in a defined angular position relative to each other. The punching stamp and the adjustment ring each have corresponding receiving members, in which an adjustment element is inserted or engages. The punching stamp and the adjustment ring can be connected or are connected by a locking seat.
SUMMARY
[0009] In some aspects of the invention, a punching tool includes a mark applied to a stamp shaft that is spaced at a distance from the axial stop which corresponds to at least an axial thickness of an adjustment ring to be used with the stamp shaft. The spacing of the mark from the axial stop ensures that the mark remains visible after a correct adjustment ring has been positioned against the axial stop.
[0010] The mark is applied to the stamp shaft in order to identify if an adjustment ring that is compatible with the punching stamp has been placed on the stamp shaft. The mark is typically located away from the axial stop by a distance that approximately corresponds to the axial thickness of an adjustment ring that is compatible with the punching stamp. When a non-compatible adjustment ring is placed on a punching stamp, the mark is typically covered by the adjustment ring. When the mark cannot be seen, the incorrect combination of an adjustment ring and a punching stamp can be identified. Although the mark is spaced away from the axial stop by a distance that corresponds to the axial thickness of the associated compatible adjustment ring, at least a portion of the mark should be spaced further apart from the axial stop so that it remains at least partially visible after the compatible adjustment ring has been fitted.
[0011] The mark can be applied during fabrication of the stamp by any of various types of machining processes (e.g., by laser inscription). If the mark is formed as part of the same laser machining process that forms the upper portion of the punching stamp, there can be little to no additional costs involved with forming the mark. Since the mark is typically formed as a notch having a very small depth, there is typically also little technical risk (e.g., risk of breaking) associated with forming the mark (e.g., as compared to stress concentrations that could be generated due to deeper notches). The mark may also be applied to the punching stamp using production methods other than laser inscription. Examples of other suitable production methods include knurling or engraving using a lathe. The methods described herein including using identifying marks applied to punching stamps to verify proper tooling combinations can be used with punching tools having adjustment rings and stamps other than the types described herein. Other types of adjustment rings and stamps can also be retrofitted to include such marks. Using punching stamps having such marks, it is also possible to omit measurement verification or estimation of the stamp height from the punching tools assembly process.
[0012] The spacing of the mark from the axial stop is typically no more than about 3 mm (e.g., no more than about 1 mm) greater than the thickness of the adjustment ring. By keeping the spacing within this range, it can be ensured that the stamp height is selected not to be too large, since the mark remains visible only if the thickness of the adjustment ring deviates only slightly from the nominal thickness of the adjustment ring. It can also be identified whether a compatible adjustment ring has been completely fitted on the punching stamp.
[0013] The correct combination of punching stamp and adjustment ring can consequently be ensured during assembly by simple visual inspection to determine if the mark is visible. In addition, it is ensured that the adjustment ring is in contact with the axial stop, which is also advantageous since a correctly selected but improperly installed adjustment ring can also lead to certain problems described above.
[0014] In some embodiments, the mark is formed by a continuous ring on the stamp shaft. Due to the continuous mark, it can be ensured that the mark remains visible from all sides. In addition, the mark is limited in an axial direction to the width of the adjustment ring and is typically 2 mm or less (e.g., about 1 mm) so that even slight deviations from the predetermined axial thickness of the adjustment ring can be identified.
[0015] In some embodiments, the axial stop includes a step formed circumferentially around the axial stop. When the axial stop includes a step, the correct combination of the punching stamp and adjustment ring is important because if an incorrect adjustment ring (e.g., an adjustment ring with a planar lower side) is fitted to the punching stamp, the punching stamp may not be able to be properly secured in the tool stamp receiving member or may collide with the tool stamp receiving member.
[0016] In another aspect of the invention, a mark is applied to the punching stamp and also to the associated adjustment ring. The marks typically have at least one common feature. Punching stamps and adjustment rings that are associated with each other can be identified using marks that correspond to each other. The corresponding feature of the marks is typically the shape of the mark and/or the color of the mark. Corresponding adjustment rings and punching stamps can consequently be identified by corresponding geometry or corresponding color of the mark. Using these types of marks, visual identification is typically carried out by an operator. Alternatively, automated identification using optical sensors is also possible. The marks can be constructed in such a manner that they indicate a radial position on the punching stamp and the adjustment ring so that they can be brought into a correct angular position in which the two components can subsequently be fixed (e.g., by an adjustment element), as discussed below. Such marks or portions of the marks, in certain embodiments, extend only over a small angular range. For example, the marks or portions can extend over a range that is less than 5° (e.g., less than 1°). In some cases, a tip can be formed on the marks for this purpose.
[0017] In some embodiments, the punching stamp and the adjustment ring have corresponding receiving members for an adjustment element in order to arrange the punching stamp and the adjustment ring in a defined angular position relative to each other. The adjustment element can be, for example, a centering pin which is inserted in two aligned axial holes in the punching stamp or the adjustment ring. If the mark on the stamp shaft is complemented by a pin connection between the stamp and adjustment ring, the punching stamp can typically be pre-assembled without additional alignment concerns. The mark on the stamp shaft helps to ensure the correct selection and the correct height of the adjustment ring and the pin connection helps to ensure the exact angular position of the punching stamp (e.g., with respect to an adjustment wedge).
[0018] In another aspect of the invention, a machine tool for the punching and/or shaping processing operation of a plate-like workpiece (e.g., a metal sheet) includes at least one punching tool, as described herein. The operationally reliable assembly of the correct adjustment ring positioned on a punching stamp allows effective control of the stamp height of the punching tool so that operational malfunctions due to an incorrect stamp height can be prevented.
[0019] In another aspect of the invention, a method of verifying the proper combination of an adjustment ring with a punching stamp includes placing the adjustment ring on the stamp shaft until the adjustment ring abuts an axial stop of the punching stamp (e.g., a stepped axial stop) and verifying whether a mark on the punching stamp or stamp shaft that is at a position spaced from the axial stop by a distance that corresponds at least to the axial thickness of an adjustment ring associated with the punching stamp remains visible after the adjustment ring abuts the axial stop.
[0020] The details of one or more embodiments of the invention are set forth in the accompanying drawings and the description below. Other aspects, features, and advantages of the invention will be apparent from the description and drawings, and from the claims.
DESCRIPTION OF DRAWINGS
[0021] FIG. 1 is a schematic illustration of a machine tool for processing plate-like workpieces.
[0022] FIGS. 2 a - c are schematic illustrations of a punching tool that includes an adjustment ring and a punching stamp having a mark on its stamp shaft.
[0023] FIGS. 3 a - c are schematic illustrations of a punching tool that includes a punching stamp having a mark on its stamp shaft and an adjustment ring having a mark thereon.
DETAILED DESCRIPTION
[0024] FIG. 1 illustrates a machine tool 1 for punching and/or shaping plate-like workpieces, such as metal sheets. The punching/shaping machine 1 has a C-shaped machine frame 2 that includes a workpiece support in the form of a workpiece table 3 that serves to support a workpiece (e.g., a metal sheet) 4 . At the upper side of the workpiece table 3 , a horizontal support plane 5 is formed that extends along an x-direction and a y-direction and supports the metal sheet 4 to be processed. Using a coordinate guide 6 , the metal sheet 4 , which is clamped to the coordinate guide 6 by collet chucks 7 , can be moved along the support plane 5 of the workpiece table 3 .
[0025] At the front end of the upper member of the C-shaped machine frame 2 , a tool stamp receiving member 8 is arranged in which a punching tool 9 having a punching stamp is supported. Additionally, a tool die receiving member 10 in which a tool die 11 is supported is provided at the front end of the lower member of the C-shaped machine frame 2 . The punching tool 9 and the tool die 11 together form a tool unit 12 for a separating and/or shaping processing operation of the metal sheet 4 .
[0026] A drive unit of the punching/shaping machine 1 is formed by a stamp drive 13 and a die drive 14 that are powered by linear drives. Using the stamp drive 13 , the tool stamp receiving member 8 together with the punching tool 9 that is supported thereon or secured thereto can be raised and lowered along a travel axis 15 with respect to the workpiece table 3 . In a comparable manner, the tool die receiving member 10 together with the tool die 11 which is supported or secured therein can be raised and lowered along the travel axis 15 with respect to the workpiece table 3 by the die drive 14 . The tool stamp receiving member 8 and the tool die receiving member 10 can further be rotationally adjusted about a tool rotation axis 16 , which is identical to the travel axis 15 , by a rotary drive.
[0027] A linear magazine 17 with additional tool units 12 is provided on the coordinate guide 6 . The tool units 12 located along the linear magazine 17 are each retained by a tool cartridge 18 and, depending on requirements, can be secured to the tool stamp receiving member 8 or the tool die receiving member 10 in order to process the metal sheet 4 .
[0028] When a tool is changed and when the workpiece is processed, the drives (e.g., the stamp drive 13 and the die drive 14 ) of the punching/shaping machine 1 are controlled by a numerical control unit 21 . The numerical control unit 21 includes a storage device 19 for storing tool data and an additional control device 20 in order to measure and control the lifting, lowering and rotational movements of both the tool stamp receiving member 8 and the tool die receiving member 10 based on the stored data relating to the workpiece 4 and the tool 12 , respectively.
[0029] FIGS. 2 a - c illustrate a construction of the punching tool 9 of FIG. 1 . As shown in FIG. 2 a , the punching tool 9 includes a punching stamp 9 a and an adjustment ring 9 b . The adjustment ring 9 b is placed on a stamp shaft 22 of the punching stamp 9 a against an axial stop or shoulder 23 that is formed on the stamp shaft 22 and includes a radially inner step 23 a . After being placed against the axial stop 23 , the adjustment ring 9 b can be secured to the stamp shaft 22 , for example, by being fixed or clamped using a fixing screw 24 a , as shown in FIG. 2 b , that extends through a gap 24 in the adjustment ring 9 b . A wedge on the adjustment ring 9 b serves to prevent rotation of the punching tool 9 in a tool retention member.
[0030] The adjustment ring 9 b has a thickness D so that when the step 23 a of the adjustment ring 9 b abuts the stepped stop 23 of the punching stamp 9 a , a stamp shaft height H is formed between the upper side of the adjustment ring 9 b and a radially continuous groove 25 of the stamp shaft 22 . The stamp shaft height H corresponds to a height H′ that is formed on the tool stamp receiving member 8 between a projection and a shoulder that the adjustment ring 9 b abuts when the punching tool 9 is secured to the tool stamp receiving member 8 . In some embodiments, the thickness D of the adjustment ring 9 b is 10 mm. When the punching stamp 9 a and adjustment ring 9 b are assembled to each other, it is ensured that the stamp shaft 22 of the punching stamp 9 a can be inserted in the tool stamp receiving member 8 since the head of the punching stamp 9 a typically does not collide with the projection on the tool stamp receiving member 8 . In the event of an incorrect combination of a punching stamp 9 a and adjustment ring 9 b , however, the stamp shaft height H between the adjustment ring 9 b and the groove 25 in the stamp shaft 22 may differ from the height H′ at the tool stamp receiving member 8 and lead to a collision.
[0031] In order to identify an incorrect assembly of a punching tool 9 having an incorrect adjustment ring 9 b placed on the punching stamp 9 a , a mark 26 in the form of a continuous ring is applied to a cylindrical portion of the stamp shaft 22 of the punching stamp 9 a . The mark 26 is spaced apart from the axial stop 23 by a spacing A that is slightly greater than the axial thickness D of the adjustment ring 9 b . In some embodiments, the spacing A is no more than 5% (e.g., 2%) greater than the axial thickness D of the adjustment ring 9 b . In some embodiments, the spacing A is no more than 1 mm greater than the axial thickness D of the adjustment ring 9 b . The size of spacing A is dependent on the height of the step 23 a at the axial stop 23 because the spacing A is typically selected to be so large that the mark 26 is covered by an incorrect adjustment ring, such as an adjustment ring whose lower side is not adapted to abut the stepped stop 23 (e.g., an adjustment ring with a planar lower side). As a result of this, the spacing A will typically not exceed the sum of the thickness D of the adjustment ring 9 b and the step height S of the step 23 a.
[0032] The mark 26 can be applied to the stamp shaft 22 by various fabrication techniques. In some embodiments, the mark 26 is applied by laser inscription. Although the mark 26 is shown as being constructed as a continuous straight line, alternatively, the mark 26 can be constructed to have other appearances (e.g., a broken line, a zigzag line, or other lines). However, the axial thickness of the mark typically does not exceed about 1 mm, in order to ensure proper recognition of the correct adjustment ring 9 b installed to the punching stamp 9 a with the stepped stop 23 .
[0033] The mark is constructed in such a manner that it remains at least partially visible after the adjustment ring 9 b has been positioned, and thus helps to ensure identification of the correct combination of a stamping punch 9 a and adjustment ring 9 b . It can also be identified whether a compatible adjustment ring 9 b is completely pushed onto the punching stamp 9 a.
[0034] The punching stamp 9 a and the adjustment ring 9 b include axial holes 27 , 28 that are positioned so that the punching stamp 9 a and adjustment ring 9 b can be properly aligned once assembled. Using a centering pin, which engages in the aligned holes 27 , 28 , the punching stamp 9 a and adjustment ring 9 b can be fixed in the correct angular position.
[0035] Using the techniques described above, the punching tool 9 can be preassembled without additional alignment devices or techniques since the mark 26 can ensure the correct selection and the correct height of the adjustment ring 9 b and the pin connection can ensure proper angular alignment of the punching stamp 9 a with respect to the adjustment ring 9 b.
[0036] The correct combination of a punching stamp and adjustment ring can also be established using another configuration of a punching tool 9 ′, as shown in FIGS. 3 a - c . As shown in FIGS. 3 a - c , both the punching stamp 9 a ′ and the adjustment ring 9 b ′, which has a thickness D, have marks 29 , 30 in the form of a triangle. Due to the corresponding shape of the marks 29 , 30 , the association or compatibility of the adjustment ring 9 b ′ with the punching stamp 9 a ′ can be identified. Additionally or alternatively, there can also be a correspondence between the marks 29 , 30 in terms of color or other features (e.g. shapes other than triangles) that allow associated pairs of punching stamps and adjustment rings, which can be assembled to form a punching tool, to be identified.
[0037] In the configuration of the punching stamp 9 a ′ shown in FIG. 3 a , which has a planar axial stop face 23 , the problem of deviation of the stamp shaft height H from the height H′ predetermined by the tool stamp receiving member 8 typically does not arise. Deviation of the stamp shaft height H from the height H′ typically does not arise because both the adjustment ring 9 b ′ (shown in FIG. 3 b ) that has a planar lower side, and the adjustment ring 9 b (shown in FIG. 2 a ) that has a recess along the lower side, could potentially be placed on the punching stamp 9 a ′ of FIG. 3 a , and the maximum stamp height would typically not be exceeded since the upper sides of the adjustment rings 9 b , 9 b ′ have the same spacing D from the stop face 23 in both cases.
[0038] Due to the marks 29 , 30 , it is also possible to align the punching stamp 9 a ′ and the adjustment ring 9 b ′ in a defined angular position. For example, when the marks 29 , 30 each have a tip, as shown in FIGS. 3 a - c , the tips of the marks 29 , 30 can be orientated in an aligned manner. It is also possible to use only the marks 29 , 30 for fixing the correct angular position of the adjustment ring 9 b ′ when the marks 29 , 30 are aligned with each other, and not additionally utilize features of the receiving members for this purpose.
[0039] The preliminary set-up operation of a punching tool can be simplified in the manners described above by utilizing a visual verification/examination of the assembled punching tool. The use of such visual verification/examination of the assembled punching tool can help to prevent assembly errors, such as an incorrect combination of a punching stamp and an adjustment ring or an incorrect clamping position of the adjustment ring with respect to the punching stamp. The visual verification typically does not require the operator to have any knowledge of punching technology. Due to the operationally reliable assembly, interruptions to production (e.g., resulting from machine down-times, tooling collisions, or other interruptions) can be prevented when the punching tools described herein are used in a machine tool.
[0040] A number of embodiments of the invention have been described. Nevertheless, it will be understood that various modifications may be made without departing from the spirit and scope of the invention. Accordingly, other embodiments are within the scope of the following claims.
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In some aspects of the invention, a punching tool includes a punching stamp including a stamp shaft and an axial stop; and an adjustment ring having a center opening configured to receive the stamp shaft and abut the axial stop, where a first mark is located along a cylindrical portion of the stamp shaft adjoining the axial stop, and at least a portion of the first mark remains visible when the adjustment ring is abutted against the axial stop.
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RELATED APPLICATIONS
The present invention is a U.S. National Stage under 35 USC 371 patent application, claiming priority to Serial No. PCT/EP2013/075928, filed on 9 Dec. 2013; which claims priority from European Patent Appln. No. 12197013.1, filed 13 Dec. 2012, the entirety of both of which are incorporated herein by reference.
FIELD OF THE INVENTION
The invention relates to a component, comprising fiber-reinforced composite materials with reinforcement areas, also to a corresponding body of rotation in case of a rotating component, and to a method for the production of these components.
BACKGROUND OF THE INVENTION
In the case of such components, additional loads occur at the connection sites to the drives or to the static load points, for example, in the shaft-hub-rim component chain, due to differences in the stiffness and/or density. These additional loads (static or dynamic) can lead to failure of the component or to a reduction in the capacity to withstand introductions of force, and thus to a diminished efficiency or performance of the component.
In order to reduce or eliminate these negative influences on the components, an attempt is made to absorb the load, usually by means of external reinforcements. Such external reinforcements, for example, in the form of a ring, are installed around the areas that are to be reinforced. Due to the relatively large distance between the external reinforcement and the site of the introduction of the load, the areas in-between are nevertheless subject to a greater load. This load can never be completely compensated for by the external reinforcement. Moreover, additional reinforcement material is necessary, which increases the material requirements for the entire component. The external reinforcement thickens the outside of the component, as a result of which a larger installation space is needed around the component at the time of its later use. Installations with such components cannot be built as compactly as would be possible without the external reinforcement. Moreover, in the case of components made of fiber-reinforced composite materials, such an external reinforcement gives rise to internal stresses in the underlying laminate, thereby promoting delamination. With an external reinforcement made of fiber-reinforced composite material, fiber ends on the surface of the reinforcement can come loose during use. As an alternative, materials other than materials with fibers could, of course, be used as the reinforcement. However, thanks to the material properties and production costs of fiber-reinforced composite materials, they are greatly preferred over other materials such as, for example, metal reinforcements.
SUMMARY OF THE INVENTION
It is the objective of the present invention to put forward a component that has space-saving reinforced areas in order to compensate for the loads exerted on the component during operation and that has a long service life.
This objective is achieved by a component with a composite area made of fiber-reinforced composite materials, comprising one or more normal areas with one or more first fibers having a first mechanical strength, and one or more reinforcement areas with one or more connection surfaces that are provided for purposes of connection to an appertaining force-transmission component in order to introduce a force into the component, and, for reinforcement purposes, the reinforcement areas comprise one or more second fibers that have a second mechanical strength that is greater than that of the first fibers.
Due to the inventive structure of the reinforcement in the reinforcement areas, the reinforcement is integrated into the component and can thus completely absorb and thus compensate for the additional load if the component is designed appropriately. The integrated reinforcement does not require any additional installation space and thus saves space. As a result, the integrated reinforcement is also arranged directly in the area where the load is introduced. Consequently, the load is absorbed directly at the place where it is generated. Therefore, the original structural volume of the component is retained, and application-related sheathing or coverings can be configured compactly. Moreover, only a minimal amount of reinforcement material is needed. In particular, no reinforcement material needs to be added to the component. This makes the integrated reinforcement more cost-effective.
The component according to the invention relates to any component that is provided in order to absorb a force that is introduced into the component by means of a force-transmission component. The loads (introductions of force) that are exerted on the component according to the invention can be, for example, static or dynamic loads. Static loads are, for example, loads resulting from a tensile load, a torsional load, or a torque load, all of which the component is supposed to counteract in a static manner. In the static case, the component or the force-transmission component is not moved by a drive. For example, a torsional load is exerted onto the component and the latter is supposed to absorb this load without intrinsic rotation or positional change. Dynamic loads are, for example, a tensile load, a torsional load, or a torque load that occur in a manner varying over the course of time and/or that physically move the component in an intended way. Therefore, the component is supposed to be coupled to such a drive via a force-transmission component. The drive can cause the component to execute, for example, a lateral or a rotating motion. Examples of such dynamic loads include, among other things, the linear movement of the component in a direction of movement in order to push or pull a load, or else they include the change or maintenance of a rotation frequency for a component rotating around an axis of rotation, whereby the component is suitable to be driven so as to rotate. Here, depending on the use of the component, the drive can be suitably selected by the person skilled in the art. For example, the drives are configured pneumatically, hydraulically, electrically or in some other suitable manner. In one embodiment, the component is provided for use as a component that rotates around an axis of rotation and that has a hollow-cylindrical shape, with the cylindrical axis as the axis of rotation, whereby the inside of the cylinder serves for purposes of connection to the force-transmission component(s). In case of a component in the form of a hollow cylinder, a force-transmission component suited for this can be a hub that is arranged inside the hollow cylinder and firmly connected to it. If the force-transmission component is connected to a shaft, the force (rotation) of the shaft is transmitted to the component via the correspondingly rotating force-transmission component via the inner connection to the component, thereby causing the component to rotate.
The fiber-reinforced composite area refers to an area or volume of the component that is made of fiber-reinforced composite materials. Such a fiber-reinforced composite material generally consists of two main components, here of fibers, embedded in a matrix material that creates the strong bond between the fibers. The fiber-reinforced composite area can be wound using one single fiber or several fibers, whereby the fiber(s) are wound next to each other in close contact with each other. This gives rise to a fiber layer on which the fibers are wound into additional fiber layers until the fiber-reinforced composite area has the desired thickness. Due to the bond, the fiber-reinforced composite attains higher-quality properties than each of the two individual components involved could provide on their own. The reinforcement effect of the fibers in the fiber direction occurs when the modulus of elasticity of the fibers in the lengthwise direction is greater than the modulus of elasticity of the matrix material, when the ultimate elongation of the matrix material is greater than the ultimate elongation of the fibers, and when the ultimate strength of the fibers is greater than the ultimate strength of the matrix material. All kinds of fibers such as, for example, glass fibers, carbon fibers, ceramic fibers, steel fibers, natural fibers or synthetic fibers can be used as the fibers. Thermosetting plastics, elastomers, thermoplastics or ceramic materials can be used as the matrix materials. The material properties of the fibers and matrix materials are known to the person skilled in the art, so that the person skilled in the art can select a suitable combination of first fibers and matrix materials in order to produce a fiber-reinforced composite area as the normal area in a component for the application in question. Here, the normal area in the fiber-reinforced composite area can be one single fiber or several identical or different first fibers having similar mechanical properties. In one embodiment, the component is made entirely of fiber-reinforced composite material. Such a component has very high strength values, along with a low weight.
The term “normal area” refers to the area of the component in which the fiber-reinforced composite is dimensioned for the normal load of the component when no load is being introduced. Therefore, in this normal area, first fibers having a first mechanical strength, which corresponds to the normal load, are used. In one embodiment, the normal area comprises exclusively such first fibers.
In the reinforcement area, a locally elevated load occurs due to the introduction of force by the force-transmission component. For purposes of reinforcement vis-à-vis the normal areas, a second fiber (either alone or in addition to the first fiber) having a greater mechanical strength than the first fibers is integrated into the reinforcement area. Therefore, higher quality fibers are used as second fibers than is the case for first fibers. Which of these will be used in a given application also depends, among other things, on the selection of the first fibers. The reinforcement area can comprise one single second fiber or several identical second fibers, or else different second fibers with similar mechanical properties. In one embodiment, the first and second fibers comprise one or more elements belonging to the group of natural fibers, synthetic fibers, ceramic fibers, glass fibers, carbon fibers, or high-strength carbon fibers. Depending on the embodiment, the individual fiber groups can have different mechanical strengths, so that the above-mentioned order does not necessarily have to match the order of mechanical strengths going from lower-strength to higher-strength fibers. Within the scope of the present invention, the person skilled in the art can select suitable pairs of first and second fibers from among the above-mentioned types of fibers. In one example, combinations of natural fibers/glass fibers or glass fibers/carbon fibers or carbon fibers/high-strength carbon fibers could be used as first and second fibers. Within the scope of the present invention, the person skilled in the art can also select other suitable combinations of first and second fibers.
Integrating the reinforcement as the reinforcement area with second fibers into the component prevents a fiber end from being exposed on the surface of the component due to the reinforcement (as can be the case in the state of the art with external reinforcements made of fiber-reinforced composite material). Thus, with the component that is reinforced according to the invention, no fiber ends can come loose in the reinforcement area during operation. Moreover, the integrated reinforcement reduces the tendency towards crack formation in the component. In one embodiment, the use of the second fibers is limited to the reinforcement area.
In one embodiment, the reinforcement area has an extension that goes beyond the extension of the connection surface within which the force-transmission component is connected to the component. As a result, the tendency towards crack formation is greatly diminished, particularly in the area of the connection surface between the force-transmission component and the component. In one embodiment, the normal area has a larger extension (or surface area) than the reinforcement area. In the case of several normal and/or reinforcement areas, the normal areas have a larger extension (or surface area) in total than the reinforcement areas in total.
In another embodiment, the fiber-reinforced composite area comprises several fiber layers consisting of fibers wound over each other, whereby, in the normal area, the fiber layers consist of first fibers, while in the reinforcement area, the fiber layers consist alternately of first and second fibers. In this manner, the bond between the normal areas and the reinforcement areas is further enhanced since every other fiber layer consists of first fibers and can be wound as a continuous fiber layer, thereby creating a strong bond in the reinforcement area with the second fibers situated between them. The reinforcement integrated in this manner reduces the internal stresses in the component that might lead to delaminations.
In another embodiment, the fiber layers consisting of second fibers have a first extension parallel to the connection surface of the component, whereby the first extensions diminish as the distance between the individual fiber layers and the connection surface increases. The fiber layer of the reinforcement area near the connection surface to the force-transmission component has to absorb the largest forces that are exerted on the component. Therefore, it is advantageous to select the extension of this fiber layer to be as large as possible. As the distance to the connection surface increases, the force introduced into the individual fiber layers decreases, so that the first extension of the fiber layers with second fibers can decrease as the distance increases and, at the same time, the loads that occur can still be compensated for by the reinforced component. In the embodiment with rotating components, the fiber layers of second fibers each have a first extension that is parallel to the axis of rotation of the component. In a preferred embodiment, the fiber layers of the second fibers—in the side sectional view of the reinforcement area—are arranged one above the other in a trapezoidal shape, whereby the lowermost fiber layer of the second fibers has the largest first extension. This special tapering shape also makes the component very robust against loads, whereby the material use of higher quality second fibers can be markedly reduced. The steepness of the trapezoidal shape on the tapering legs can be adapted to the application in question.
In another embodiment, the arrangement of the second fibers in the reinforcement area is configured in such a way that the geometric shape of the fiber-reinforced composite area in the reinforcement area does not diverge from the geometric shape of the adjacent normal area, whereby the reinforcement area preferably has the same thickness as the adjacent normal area(s). Due to the reinforcement that is integrated into the existing fiber layer by means of the second fibers, any enlargement of the diameter of the component in the reinforcement area can be avoided, as a result of which the components according to the invention can be produced with an ideal structural volume (that has not been enlarged by any reinforcing measures).
In another embodiment, first fibers can be arranged in the reinforcement area, at least on the surfaces of the component facing and/or facing away from the connection surface. As a result, the integrated reinforcement is not visible towards the outside, since the fiber layers located on the surfaces are not different in the normal area and the reinforcement area. Thus, the component has the same surface properties towards the outside over the entire fiber-reinforced composite area. This is especially advantageous for applications of the component as a transport roller for objects that have to be transported in this manner. Such transport rollers are used, for example, in printing machines.
In another embodiment, the first fibers are arranged at a first mean fiber angle relative to the direction of the introduction of force into the component, and the second fibers are arranged at a second mean fiber angle relative to the direction of the introduction of force into the component, whereby the second mean fiber angle is smaller than the first mean fiber angle. Due to the favorable design of the fiber angle in the reinforcement area, where the fiber is oriented more in the direction of the load introduction than it is in the normal range, the component can be even further reinforced, in addition to the reinforcement achieved through the added second fibers. Fibers have their greatest strength in the fiber direction. If the load introduction is brought about by a tensile force, then the second fiber angle in the reinforcement area preferably corresponds to angles within the range between 0° and the tensile direction. If the load introduction is brought about by a torsional force, then second fiber angles in the range between 45° and the longitudinal axis of the component are advantageous. In contrast, for example, in the case of rotating components, the reinforcement area is mechanically even more robust against load introductions if the fiber angle corresponds to a 90° angle relative to the axis of rotation of the component.
In one embodiment, in which the component is provided for use as a component that rotates around an axis of rotation and that has a hollow-cylindrical shape with the cylindrical axis as the axis of rotation—whereby the inside of the cylinder is provided for purposes of connection to the force-transmission component(s)—the first fibers are arranged with a first mean fiber angle relative to the axis of rotation of the component, and the second fibers are arranged with a second mean fiber angle relative to the axis of rotation of the component, whereby the second mean fiber angle is larger than the first mean fiber angle. Thus, the second fibers in the reinforcement area are arranged in the direction of the introduction of force into the rotating component, thereby reinforcing the component in the fiber direction.
The invention also relates to a body of rotation having a component according to the invention to be used as a component that rotates around an axis of rotation, and it also relates to one or more force-transmission components that are connected inside a connection surface to the component in order to introduce force, whereby the force-transmission components are each appropriately supported via a shaft or journal in a bearing, and at least one of the shafts or journals can be appropriately driven by means of a drive. The advantages described above apply likewise to the correspondingly designed bodies of rotation.
In one embodiment, the body of rotation is used as a shaft or rim in order to operate machines or components, preferably as a ship's shaft, a drive shaft, a motor shaft, a gear shaft, a shaft in a printing machine, or as a rotor to store energy. The rotating components described above can be used universally for a wide variety of application purposes. Within the scope of the present invention, the person skilled in the art can also use the bodies of rotation according to the invention for other application purposes.
The invention also relates to a method for the production of a component according to the invention, comprising the following steps:
(a) a fiber layer consisting of first fibers is wound onto a winding core at least in a normal area;
(b) in a reinforcement area, second fibers are wound onto the winding core in the same fiber layer next to the first fibers in the normal area;
(c) additional fiber layers consisting of first and second fibers are wound by repeating the method steps (a) and (b) until the desired shape of the component has been wound;
(d) the fiber layers are cured and/or cooled and the winding core is removed.
The above-mentioned order of the method steps does not correspond here to a time sequence. Method steps (a) and (b) can also be carried out in the reverse order. In one embodiment, after steps (b) and/or (c), an interim hardening step can be carried out for the already wound fiber layers.
In one embodiment, the method comprises the additional step that, between each fiber layer consisting of first and second fibers, a fiber layer consisting only of first fibers is wound in the entire fiber-reinforced composite area, preferably the first and last fiber layer that is wound consists only of first fibers in the entire fiber-reinforced composite area.
BRIEF DESCRIPTION OF THE FIGURES
These and other aspects of the invention are shown in detail in the figures as follows:
FIG. 1 two embodiments of the component according to the invention;
FIG. 2 bodies of rotation with a reinforced component according to the state of the art;
FIG. 3 an embodiment of a cylindrical body of rotation with a component according to the invention, in a side sectional view;
FIG. 4 an embodiment of the fiber layers in the normal area and in the reinforcement area of a component according to the invention, in a side sectional view;
FIG. 5 an embodiment of the fiber orientation of first and second fibers in the component according to the invention, in a top view of the top of the component;
FIG. 6 an embodiment of the fiber layers in the normal area and in the reinforcement area of a component according to the invention, in a side sectional view.
DETAILED DESCRIPTION OF THE EMBODIMENTS
FIG. 1 shows two components 41 according to the invention, in a perspective view with a fiber-reinforced composite area 42 made of fiber-reinforced composite materials, comprising a normal area 421 with one or more first fibers F 1 having a first mechanical strength, and a reinforcement area 422 with a connection surface 43 , that are provided for purposes of connection to a force-transmission component 3 in order to introduce a force K into the component 41 , whereby, for reinforcement purposes, the reinforcement area 422 has one or more second fibers F 2 having a second mechanical strength that is higher than that of the first fibers F 1 . Preferably, exclusively first fibers F 1 are arranged in the normal area 421 . The first and second fibers are not shown in detail here. In this embodiment, the components 41 shown are made completely of fiber-reinforced composite materials since the fiber-reinforced composite area 42 extends over the entire length of the components 41 . In other embodiments, the fiber-reinforced composite area 42 can also make up only a portion of the component. For the fiber layers and fiber orientations in the components 41 shown in FIG. 1 , reference is hereby made to FIGS. 3 to 6 . The fiber arrangements, the fiber layers and the fiber orientations shown there can be used or arranged accordingly in the components 41 shown by way of an example in FIG. 1 . FIG. 1( a ) shows a component 41 on whose end there is a reinforcement area 422 that has a circular connection surface 43 . Here, the force-transmission component 3 exerts a force K in the form of a tensile force or pushing force onto the component 41 . The tensile force or pushing force K can be exerted by the force-transmission component 3 , for example, mechanically or electromagnetically. The force is introduced via the connection surface 43 . The introduced force K is absorbed by the reinforcement area 422 in such a way that the component 41 can absorb the load by means of the second fibers F 2 in the reinforcement area 422 , and the portions of the component 41 that are exposed to a lesser load can be configured as normal areas 421 with first fibers F 1 . Here, the second fibers F 2 can be arranged at a small angle (fiber angle) relative to the lengthwise direction perpendicular to the connection surface 43 of the component 41 in order to even further enhance the reinforcement of the component 41 in the reinforcement area 422 , in addition to its favorable mechanical properties.
FIG. 1( b ) shows another embodiment of the component 41 according to the invention. At the end of the component 41 , which has, for instance, a cuboidal configuration, there is a reinforcement area 422 with a rectangular connection surface 43 . The force-transmission component 3 is statically connected to the component 41 at the connection surface 43 and here, it exerts a torsional force K (indicated by the curved arrow) onto the component 41 . The torsional force K on the connection surface 43 is generated here, for example, mechanically, by a weight 7 that is attached to the end of the force-transmission component 3 . The force is introduced via the connection surface 43 in the direction of the torque generated by the torsional force. The introduced force K is absorbed by the reinforcement area 422 in such a way that the component 41 can absorb the load by means of the second fibers F 2 in the reinforcement area 422 , and the portions of the component 41 that are exposed to a lesser load can be configured as normal areas 421 with first fibers F 1 . Here, in one embodiment, because of the exerted torsional force, the second fibers F 2 can be arranged at an angle of 45°±5° relative to the lengthwise direction perpendicular to the connection surface 43 of the component 41 so that, in addition to its favorable mechanical properties, the reinforcement of the component 41 can be even further enhanced in the reinforcement area 422 .
FIG. 2 shows a body of rotation 1 with a rotating component 11 according to the state of the art that has been reinforced from the outside by means of ring-like outer reinforcements 12 in order to compensate for loads during the acceleration and deceleration of the component 11 or rotation of the component 11 at a constant speed brought about by a force acting on the drive shaft 2 . The drive shaft 2 , as a force-transmission component, acts upon the component 11 via a hub 3 attached to the inside of the component. The hub 3 is only shown with a broken line since, in this perspective view, it is covered by the component 11 . The component has a diameter DB without external reinforcements. If the component is installed in a machine, then a larger volume has to be kept free around the component since the external reinforcements 12 increase the effective diameter of the body of rotation 1 to a diameter DV. Thus, the component 11 cannot be installed into its surroundings in a way that saves as much space as would be possible without external reinforcements. Nevertheless, it is not possible to do without the external reinforcements 12 since otherwise, the loads that are exerted on the component 11 via the hub 3 would cause damage to the component 11 , for example, crack formation in the area of the component 11 around the hub 3 . Moreover, if the external reinforcements 12 are made of fiber-reinforced composite material, there is a risk that the external reinforcements 12 will become frayed during operation, thereby diminishing the reinforcement and correspondingly reducing the mechanical strength of the component 11 , in addition to which the surroundings of the component 11 would also be soiled with loose fibers.
In contrast, FIG. 3 shows an embodiment of a cylindrical body of rotation 4 with the component according to the invention, in this embodiment as a rotating component in a side sectional view. The component 41 has a reinforcement that is integrated into the provided fiber-reinforced composite in appropriately configured reinforcement areas 422 . The body of rotation 4 comprises a component 41 and two force-transmission components 3 that are each firmly connected inside a connection surface 43 to the component 41 in order to vary the rotation energy of the body of rotation 4 , whereby the force-transmission components 3 are each suitably mounted via a shaft 2 in a bearing 5 , and at least one of the shafts 2 can be appropriately driven by means of a drive 6 . In this embodiment, the component 41 has a hollow-cylindrical shape with the cylinder axis as the axis of rotation R, whereby the inside of the cylinder OB 1 serves for purposes of connection to the force-transmission components 3 . The wall thickness 41 D of the component 41 is schematically indicated by the double arrow and can vary greatly, depending on the application in question. In other embodiments, the body of rotation 4 can also comprise a force-transmission component 3 that extends through the entire area of the cylindrical component 41 or that fills up the entire inner area that is surrounded by the component. In principle, the same statements apply for these embodiments, except that the connection areas 43 vary accordingly, and the forces that are coupled into the component 41 are distributed accordingly. The component comprises a fiber-reinforced composite area 42 that is made of fiber-reinforced composite materials and that has one or more normal areas 421 with one or more first fibers F 1 having a first mechanical strength, and one or more reinforcement areas 422 that are provided for purposes of connection to an appertaining force-transmission component 3 in order to introduce a load into the component 41 and, for purposes of reinforcement, they comprise one or more second fibers F 2 that have a second mechanical strength that is higher than that of the first fibers F 1 . In the embodiment shown here, the entire component 41 is made of fiber-reinforced composite material. Here, the reinforcement areas 422 have extensions that are parallel to the axis of rotation R and that go beyond the extension 43 A of the appertaining connection surfaces 43 within which the force-transmission component 3 is connected to the component 41 . As shown in FIG. 3 , in this embodiment, the normal area 421 has a much larger extension in total over all of the normal areas 421 than the reinforcement areas 422 in total. In this embodiment, the appertaining force-transmission components 3 are configured to be disc-shaped, so that the connection surface 43 runs around in the surface OB 1 of the component facing the axis of rotation. However, the force-transmission components can also be configured to be spoke-shaped, so that there are several separate connection surfaces 43 per force-transmission component 3 . The arrangement of the second fibers F 2 is configured in the reinforcement area 422 in such a way that preferably, the geometric shape of the fiber-reinforced composite area 42 in the reinforcement area 422 does not diverge from the geometric shape of the adjacent normal area 421 , whereby the reinforcement area 422 has the same thickness 41 D as the appertaining adjacent normal areas 421 . The surface of the component 41 that faces away from the axis of rotation is referred to as the surface OB 2 . The body of rotation 4 shown can be used, for example, as a shaft or rim in order to operate machines or components, preferably as a ship's shaft, a drive shaft, a motor shaft, a gear shaft, a shaft in a printing machine, or as a rotor to store energy.
FIG. 4 shows an embodiment of the fiber layers FL in the normal area 421 and in the reinforcement area 422 of a component 41 according to the invention, for example, for static or dynamic loads, in a side view. In this embodiment, in the normal areas 421 as well as in the reinforcement areas 422 , the fiber-reinforced composite area 42 comprises several fiber layers FL consisting of fibers F 1 , F 2 wound over each other, whereby the fiber layers FL consist exclusively of first fibers F 1 (shown here as solid lines) in the normal area 421 , and alternately of first fibers F 1 and second fibers F 2 (shown here as broken lines) in the reinforcement area 422 . The number of fiber layers FL shown here serve only to illustrate the fiber layer structure. In most components 41 , the number of fiber layers FL will be considerably larger than shown here. Due to the arrangement of the second fibers F 2 in the reinforcement area 422 , which are integrated into the existing fiber layer structure of the normal areas 421 , the geometric shape of the fiber-reinforced composite area 42 in the reinforcement area 422 ideally does not diverge from the geometric shape of the adjacent normal area 421 . In particular, the reinforcement area 422 has the same thickness 41 D as the adjacent normal areas 421 . Thus, the component 41 according to the invention, with its excellent robustness against mechanical loads, can be installed in the appropriate machine environment in a very space-saving manner. Moreover, in this embodiment, first fibers F 1 are arranged in the reinforcement area 422 on the surfaces of the component 41 facing OB 1 and/or facing away from OB 2 the connection surface. Consequently, the component 41 has the same surface properties over the entire surfaces OB 1 and OB 2 . Thus, the application properties of the component 41 are not influenced by the positioning of the reinforcement areas 422 . As a result, the bond between the normal areas 421 and the reinforcement areas 422 is greatly increased, since every other fiber layer FL consists of first fibers F 1 and is wound as a continuous fiber layer FL, thereby creating a strong bond in the reinforcement area 422 with the second fibers F 2 located in-between. The reinforcement integrated in this manner reduces the internal stresses in the component 41 that might lead to delaminations.
FIG. 5 shows an embodiment of the fiber orientation of first and second fibers F 1 , F 2 in the component 41 according to the invention, in a top view of the top OB 2 of the component 41 . The component 41 is a component 41 that rotates around the axis of rotation R. In the case of rotating components, the force transmitted by the force-transmission component is introduced tangentially to the surface. Thus, the direction of the introduction of force is at a 90° angle relative to the axis of rotation R. The first fibers F 1 are arranged with a first mean fiber angle MF 1 relative to the axis of rotation R of the component 41 that is used in this embodiment as a rotating component 41 , and the second fibers F 2 are arranged with a second mean fiber angle MF 2 relative to the axis of rotation R of the rotating component 41 , whereby the second mean fiber angle MF 2 is larger than the first mean fiber angle MF 1 . The mean fiber angles MF 1 , MF 2 are the angles between the fiber orientations projected onto the axis of rotation R as well as the axis of rotation R, since the fibers F 1 , F 2 never really intersect the axis of rotation R in view of the fact that the axis of rotation R runs centrally through the component 41 , whereas the fibers F 1 , F 2 constitute the sheathing that has a wall thickness 41 D and that surrounds the axis of rotation R. The fiber angle can vary considerably, depending on the application purpose. In embodiments where, for example, the mean fiber angles MF 1 , MF 2 of the first and second fibers F 1 , F 2 are the same, the reinforcement is determined by the fiber properties of the second fiber F 2 relative to the first fiber F 1 . In embodiments in which the mean fiber angles MF 1 , MF 2 are different, the fiber angle difference makes an additional contribution to the degree of reinforcement in the reinforcement areas 422 . Due to the favorable design of the fiber angle MF 2 in the reinforcement area 422 , the component 41 can be even further reinforced, in addition to the reinforcement achieved by the added second fibers F 2 . Fibers have the greatest strength in the fiber direction. Thus, the closer the fiber angel MF 2 is to a 90° angle relative to the axis of rotation R, the more mechanically robust the reinforcement area 422 is against loads. In another embodiment, for non-rotating components 41 , the first fibers F 1 are arranged with a first mean fiber angle MF 1 relative to the direction of introduction of force into the component 41 , and the second fibers F 2 are arranged with a second mean fiber angle MF 2 relative to the direction of introduction of force into the component 41 , whereby the second mean fiber angle MF 2 is smaller than the first mean fiber angle MF 1 . In this embodiment, the second fibers are only arranged in the reinforcement area, but not in the normal area.
As an alternative to FIG. 4 , FIG. 6 shows another embodiment of the fiber layers FL in the normal area 421 and in the reinforcement area 422 of a component 41 according to the invention, in a side view. Here, the fiber layers FL of second fibers F 2 each have a first extension A 1 parallel to the connection surface 43 or to the axis of rotation R of the component 41 , whereby the first extensions A 1 diminish as the distance AR from the individual fiber layers FL to the connection surface 43 or to the axis of rotation R increases. Here, the fiber layers FL of the second fibers F 2 —in a side sectional view of the reinforcement area 422 —are arranged one above the other in a trapezoidal shape, whereby the lowermost fiber layer FL-U of the second fibers F 2 has the largest first extension A 1 . The fiber layer of the reinforcement area 422 near the connection surface 43 to the force-transmission component 3 has to absorb the largest forces that are exerted on the component 41 . Therefore, it is advantageous to select the extension of this fiber layer FL-U to be as large as possible. As the distance AR to the connection surface 43 increases, the force coupled into the appertaining fiber layers FL decreases, so that the first extension A 1 of the fiber layers FL of second fibers F 2 can decrease as the distance AR increases, and at the same time, the loads that occur can still be compensated for by the reinforced component 41 . This special tapering trapezoidal shape shown in FIG. 5 also makes the component 41 very robust against loads, whereby the material use of higher quality second fibers F 2 can be markedly reduced. The steepness of the trapezoidal shape on the tapering legs can be adapted to the application in question. The diminishing first extensions A 1 even further strengthen the bond with the first fibers F 1 of the overlapping next fiber layer FL.
The embodiments shown here constitute merely examples of the present invention and therefore must not be construed in a limiting fashion. Alternative embodiments considered by the person skilled in the art are likewise encompassed by the scope of protection of the present invention.
List of reference numerals
1
body of rotation according to the state of the art
11
component according to the state of the art
12
external reinforcement of the component according
to the state of the art
2
(drive) shaft or journal
3
force-transmission component (for example, hub)
4
body of rotation according to the invention
41
component according to the invention
41D
wall thickness of the component
42
fiber-reinforced composite area
421
normal area in the fiber-reinforced composite area
422
reinforcement area in the fiber-reinforced composite area
43
connection surface between the force-transmission component
and the component
43A
extension of the connection surface parallel to the
axis of rotation
5
bearing of the shaft
6
drive used to drive the shaft
7
weight
A1
first extensions of the fiber layers with second fibers parallel to
the axis of rotation
AR
distance to the axis of rotation
DB
diameter of the component
DV
diameter of the component with external reinforcement
F1
first fiber
F2
second fiber
FL
fiber layer(s)
FL-U
lowermost fiber layer of the second fibers
K
force exerted on the component (introduction of force)
MF1
first mean fiber angle of the first fibers
MF2
second mean fiber angle of the second fibers
OB1
surface of the component facing the axis of rotation, inside of
the cylinder
OB2
surface of the component facing away from the surface
of the component
R
axis of rotation
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The invention relates to a component for use as a rotating component, to a corresponding rotational body and to a method for producing said component. The component comprises a fiber-composite region consisting of fiber-composite materials and embedded fibers, said region having one or more normal regions comprising one or more first fibers with a first mechanical load-bearing capacity and one or more reinforcement regions, said reinforcement regions being provided for connection to a respective force-transmission component, in order to vary the rotational energy of the component, and comprising as a reinforcement one or more second fibers with a higher load-bearing capacity in relation to the first fibers. The invention thus provides a component comprising space-saving reinforced regions, said component being capable of compensating the stresses on the component during operation and having a long service life.
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RELATED APPLICATION
This application is related to copending application entitled Rotary Drill Bit with Improved Cutter and Seal Protection, Ser. No. 08/221,841, filed Mar. 31, 1994 (Attorney Docket No. 60220-0123).
TECHNICAL FIELD OF THE INVENTION
This invention relates in general to rotary cone drill bits used in drilling a borehole in the earth and in particular to composite cone cutters with enhanced downhole performance.
BACKGROUND OF THE INVENTION
One type of drill used in forming a borehole in the earth is a roller cone bit. A typical roller cone bit comprises a body with an upper end adapted for connection to a drill string. Depending from the lower end portion of the body are a plurality of arms, typically three, each with a spindle protruding radially inward and downward with respect to a projected rotational axis of the body. A cone cutter is mounted on each spindle and supported rotatably on bearings acting between the spindle and the inside of a spindle-receiving cavity in the cutter. On the underside of the body and radially inward of the arms are one or more nozzles. These nozzles are positioned to direct drilling fluid passing downwardly from the drill string toward the bottom of the borehole being formed. The drilling fluid washes away the material removed from the bottom of the borehole and cleanses the cutters, carrying the cuttings radially outward and then upward within the annulus defined between the bit body and the wall of the borehole.
Protection of the bearings which allow rotation of the respective roller cone cutters can lengthen the useful service life of the bit. Once drilling debris is allowed to infiltrate between the bearing surfaces of the cone and spindle, failure of the bearing and the drill bit will follow shortly. Various mechanisms have been employed to help keep debris from entering between the bearing surfaces. A typical approach is to utilize an elastomeric seal across the gap between the bearing surfaces of the rotating cone cutter and its support on the bit. However, once the seal fails, it again is not long before drilling debris contaminates the bearing surfaces via the gap between the rotating cutter and the spindle. Thus, it is important that the seal be fully protected against wear caused by debris in the borehole.
At least two prior art approaches have been employed to protect the seal from debris in the well. One approach is to provide hardfacing and wear buttons on opposite sides of the gap between the spindle support arm and cutter, respectively, where the gap opens to the outside of the bit and is exposed to debris-carrying well fluid. These buttons slow the erosion of the metal adjacent the gap, and thus prolong the time before the seal is exposed to borehole debris. Another approach is to construct the inner-fitting parts of the cutter and the spindle support arm so as to produce in the gap a tortuous path to the seal that is difficult for debris to follow. An example of this latter arrangement is disclosed in U.S. Pat. No. 4,037,673.
An example of the first approach is used in a conventional tri-cone drill bit wherein the base of each cone cutter at the juncture of the respective spindle and support arm is defined at least in part by a substantially frustoconical surface, termed the cone backface. This cone backface is slanted in the opposite direction as the conical surface of the shell or tip of the cutter and includes a plurality of hard metal buttons or surface compacts. The latter are designed to reduce the wear of the frustoconical portion of the backface on the cone side of the gap. On the other side of the gap, the tip of the arm is protected by a hardfacing material. For definitional purposes, that portion of the arm which is on the outside of the bit and below the nozzle is referred to as a shirttail surface or simply shirttail. More specifically, in referring to prior art bits, radially outward of the juncture of the spindle with the arm, and toward the outer side of the bit, the lower pointed portion of the shirttail is referred to as the tip of the shirttail or shirttail tip.
During drilling with rotary bits of the foregoing character, debris often collects between the backface of the cone cutters and the wall of the borehole generally within the area where the respective gaps associated with each cone cutter open to the borehole annulus. As a result, the underside of the edge of the shirttail tips which lead in the direction of rotation of the bit during drilling, i.e., the leading edge, can become eroded. As this erosion progresses, the hardfacing covering the shirttail tips eventually chips off. This chipping exposes underlying softer metal to erosion and thereby shortens the path that debris may take through the gap to the seal. This path shortening ultimately exposes the seal to borehole debris and thereby causes seal failure.
SUMMARY OF THE INVENTION
The present invention contemplates an improved rotary cone drill bit by novel construction of the interfitting relationship between the associated cone cutters and their respective support arms to better protect against erosion at the clearance gap between each cone cutter and its respective arm and, thereby, better protect seals disposed in the gap associated with each cone cutter. The present invention also includes a composite cone cutter with improved wearing surfaces and enhanced service life.
In one aspect of the invention, a support arm and cone cutter assembly of a rotary rock bit having a body provides superior erosion protection. The assembly includes an arm integrally formed with the body and having an inner surface, a shirttail surface, and a bottom edge. The inner surface and the shirttail surface are contiguous at the bottom edge. A spindle is attached to the inner surface and is angled downwardly with respect to the arm. A portion of the spindle defines an inner sealing surface. The assembly also includes a cutter that defines a cavity with an opening for receiving the spindle. A portion of the cavity defines an outer sealing surface that is concentric with the inner sealing surface. The assembly further includes a seal for forming a fluid barrier between the inner and outer sealing surfaces. A gap associated with each support arm and cone cutter assembly includes a portion formed between the respective cavity and spindle, and has an opening contiguous with the bottom edge of the respective support arm.
In another aspect of the invention, a composite cone cutter is provided with the backface of the cone having a hard metal covering such as hardfacing. Alternatively, a portion of the composite cone including the backface may itself be made of hard metal so that the base of the composite cone adjacent the gap is highly resistant to both erosion and wear. In accomplishing this, an important and preferred aspect of the invention is the formation of a composite cone cutter for a rotary cone drill bit which is comprised of dissimilar materials normally incompatible with each other under the usual processing steps required for the manufacture of a rotary cone drill bit. Specifically, the cone backface may be formed of a hard metal material that is more resistant to erosion and wear than conventional hardfacing materials and also incompatible with the usual heat-treating processes to which the main portion or shell of the cone body is subjected.
The invention also resides in the novel construction of the body of the cone cutter with the separate formation of a base portion comprised of a nonheat-treatable material and a conical tip or shell comprised of a conventional heat-treated steel. Subsequently, the base and tip are joined securely together in a manner which is non-destructive to the heat-treated characteristics of the tip and the high hardness characteristics of the base. The present invention results in a composite cone cutter having metallurgical characteristics which optimize downhole performance while at the same time allowing for reliable, efficient manufacturing of the composite cone cutter.
An important technical advantage of the present invention includes the ability to fabricate or manufacture a backface ring separately from the shell or tip of the cone cutter body. Thus, various types of wear buttons, inserts, and/or compacts may be fabricated as an integral part of the backface ring during the associated molding or casting process. Also, fabrication of the backface ring as a separate component allows molding a layer of diamonds and/or diamond particles as an integral part of the backface ring. The present invention allows designing and fabrication of a backface ring which will optimize the downhole performance of the associated cone cutter without affecting the performance of the shell or tip of the cone cutter body.
The foregoing and other advantages of the present invention will become more apparent from the following description of the preferred embodiments for carrying out the invention when taken in conjunction with the accompanying drawings.
BRIEF DESCRIPTION OF THE DRAWINGS
For a more complete understanding of the present invention, and the advantages thereof, reference is now made to the following descriptions taken in conjunction with the accompanying drawings, in which:
FIG. 1 is an isometric view of a rotary cone drill bit embodying the novel features of the present invention;
FIG. 2 is an enlarged drawing partially in section and partially in elevation with portions broken away showing one of the rotary cone cutters mounted on a support arm of the drill bit illustrated in FIG. 1;
FIG. 2A is an enlarged drawing of the rotary cone cutter illustrated in FIG. 2;
FIG. 3 is a drawing partially in section and partially in elevation with portions broken away showing a rotary cone cutter incorporating an alternative embodiment of the present invention in drilling engagement with the bottom of a borehole;
FIG. 4A is an enlarged isometric drawing of a backface ring incorporating one embodiment of the present invention satisfactory for use with the rotary cone cutters of FIGS. 1 and 2;
FIG. 4B is an enlarged isometric drawing of a backface ring incorporating another embodiment of the present invention satisfactory for use with the rotary cone cutters of FIGS. 1 and 2;
FIG. 4C is an enlarged isometric drawing of a backface ring incorporating another embodiment of the present invention satisfactory for use with the rotary cone cutters of FIGS. 1 and 2; and
FIG. 4D is an enlarged isometric drawing of a backface ring incorporating an alternative embodiment of the present invention satisfactory for use with the rotary cone cutters of FIGS. 1 and 2.
DETAILED DESCRIPTION OF THE INVENTION
The preferred embodiments of the present invention and its advantages are best understood by referring to FIGS. 1-4D of the drawings, like numerals being used for like and corresponding parts of the various drawings.
As shown in the drawings for purposes of illustration, the present invention is embodied in a rotary cone drill bit 10 of the type utilized in drilling a borehole in the earth. Rotary cone drill bit 10 may sometimes be referred to as a "rotary rock bit." With rotary cone drill bit 10, cutting action occurs as cone-shaped cutters 11 are rolled around the bottom of the borehole by rotation of a drill string (not shown) attached to bit 10. Cutters 11 may sometimes be referred to as "rotary cone cutters" or "roller cone cutters."
As shown in FIG. 1, cutters 11 each include cutting edges formed by grooves 12 and protruding inserts 13 which scrape and gouge against the sides and bottom of the borehole under the weight applied through the drill string. The formation of material debris thus created is carried away from the bottom of the borehole by drilling fluid ejected from nozzles 14 on underside 15 of bit 10. The debris-carrying fluid generally flows radially outward between underside 15 or exterior of bit 10 and the borehole bottom, and then flows upwardly toward the well head (not shown) through an annulus 16 (FIG. 3) defined between bit 10 and side wall 17 of the borehole.
As shown in FIG. 1, rotary cone drill bit 10 comprises an enlarged body 19 with a tapered, externally-threaded upper section 20 adapted to be secured to the lower end of the drill string. Depending from the body are three support arms 21 (two visible in FIG. 1), each with a spindle 23 (FIGS. 2 and 3) connected to and extending from an inside surface 24 thereof and a shirttail outer surface 25. Spindles 23 are preferably angled downwardly and inwardly with respect to bit body 19 so that as bit 10 is rotated, the exterior of cutters 11 engage the bottom of the borehole. For some applications, spindles 23 may also be tilted at an angle of zero to three or four degrees in the direction of rotation of drill bit 10.
Within the scope of the present invention, each of three cutters 11 is constructed and mounted on its associated spindle 23 in a substantially identical manner (except for the pattern of the rows of inserts 13). Accordingly, only one of arm 21/cutter 11 assemblies is described in detail, it being appreciated that such description applies also to the other two arm-cutter assemblies.
FIGS. 2 and 3 show alternative embodiments of the present invention represented by roller cone cutters 11 and 11" which may be satisfactorily use with a rotary drill bit such as shown in FIG. 1. Drill bit 10 of FIGS. 1 and 2 is essentially equivalent in structure and operation to drill bit 10" of FIG. 3, except for modifications to shirttail surface 25" and cone cutter 11". The dimensions of base portion or backface ring 30" have also been modified to accommodate shorter shirttail surface 25" shown in FIG. 3. These modifications will be described later in more detail.
As shown in FIG. 2, inserts 13 are mounted within sockets 27 formed in a conically-shaped shell or tip 29 of cutter 11. Various types of inserts and compacts may be used with tip 29 depending upon the intended application for the resulting drill bit. For example, oval shaped compacts (not shown) may be used to provide longer service life with less wear. Also, tip 29 could be formed with one or more rows of teeth (not shown).
Base portion 30 of cutter 11 includes grooves 12 and is frustoconical in shape, but angled in a direction opposite the angle of tip 29 on the outer surface thereof. Base 30 also includes a frustoconically-shaped outer portion 33 with backface 31 formed on the outer surface thereof and an end portion 34 extending radially relative to central axis 35 of spindle 23. Base 30 and tip 29 cooperate to from composite cone cutter 11. Base portion 30 may also be referred to as a "backface ring".
Opening inwardly of end portion 34 is a generally cylindrical cavity 36 for receiving spindle 23. A suitable bearing 37 is mounted on spindle 23 and engages between a bearing wall 39 of cavity 36 and an annular bearing surface 38 on spindle 23. A conventional ball retaining system 40 secures cutter 11 to spindle 23.
FIG. 2 is an enlarged view in section and elevation of support arm 21 and its associated spindle 23 with composite cutter cone 11 mounted thereon. A gap 41 is formed between the interior of cylindrical cavity 36 and adjacent inside surface 24 of supporting arm 21 and/or the exterior portions of spindle 23. The tip of shirttail surface 25 cooperates with end portion 34 of base portion 30 to partially define first section 52 of gap 41. Second section 54 of gap 41 is defined by the interior of cavity 36 and the exterior of spindle 23. First section 52 of gap 41 lies in a plane that is generally perpendicular to spindle axis 35. Second section 54 of gap 41 extends approximately parallel with spindle axis 35. Thus, gap 41 includes first section 52 which is substantially perpendicular to second section 54.
An elastomeric seal 43 is disposed within gap 41 between spindle 23 and the interior of cavity 36 to block the infiltration of well fluids and debris through gap 41. Seal 43 is located adjacent the juncture of spindle 23 with support arm 21. Seal 43 both retains lubricants within bearing 37 and protects against the infiltration of debris through gap 41 to the space between the relatively-rotating bearing surfaces 38 and 39 of spindle 23 and cutter 11. Seal 43 protects the associated bearing 37 from loss of lubricants and such debris, and thus prolongs the life of drill bit 10.
Gap 41 includes an opening located adjacent outside surface or shirttail 25 and contiguous with the bottom edge of arm 21, and is thus open to fluid communication with borehole annulus 16. It is important that the width of gap 41 be kept relatively small and the length of gap 41 between its opening to annulus 16 and seal 43 be kept relatively long so as to reduce the infiltration of debris that may wear against seal 43 as bit 10 rotates.
The dual-section structure of gap 41 also inhibits debris from entering between bearing surfaces 38 and 39. The structure of gap 41 is shown in more detail in FIG. 2A. Typically, debris entering first section 52 will have insufficient momentum to flow into second section 54. Such debris will simply fall from section 52 back into annulus 16 instead of wearing on seal 43. Thus, both the positioning of the opening of gap 41 (adjacent to surface 25 and contiguous with the bottom edge of arm 21) and its dual-section structure provide seal 43 with debris-wear protection. Backface 31 preferably extends a sufficient distance X beyond the edge of shirttail surface 25 to deflect the drilling fluid away from the opening of gap 41 which further prevents fluid-borne debris from contacting seal 43 and entering between bearing surfaces 38 and 39 via gap 41.
In accordance with another aspect of the present invention as best shown in FIG. 3, cutter 11" and bit support arm 21 are uniquely constructed so that base portion 30" of cutter 11" interfits with spindle 23 which allows gap 41" to extend throughout its length in a direction substantially parallel to spindle axis 35. Specifically, gap 41" includes an outer cylindrical segment which intersects with shirttail surface 25" and opens upwardly and outwardly from between spindle 23 and cutter 11" into borehole annulus 16. As a result, hard metal surfaces may be positioned to better protect gap 41 against erosion, and the service life of seal 43 is lengthened, particularly over those prior art arrangements having a shirttail tip with an underside that over time, may be exposed by erosion to borehole debris.
As shown in both FIGS. 2 and 3, the bottom of shirttail 25 and 25" adjacent respectively to gaps 41 and 41" may be covered with a layer 46 of conventional hardfacing material to help protect against erosion widening gap 41 by eroding arm 21. A preferred hardfacing material comprises tungsten carbide particles dispersed within a cobalt, nickel, or iron-based alloy matrix, and may be applied using well known fusion welding processes.
As shown in FIG. 2 additional protection against erosion may be achieved by spacing outer portion 33 and backface 31 of cutter 11 radially outward a distance X from hardfacing layer 46. Distance X allows backface 31 to deflect the flow of drilling fluid enough to prevent the fluid from flowing directly into the opening of gap 41. Distance X is a function of the borehole diameter and the bit type (no seal, seal, or double seal), and may range from 1/16" to 3/16". For one embodiment of the present invention, X is approximately 1/8".
For enhanced wearability of backface 31 on the cone side of gap 41, backface 31 is either provided with a hard material covering or made from hard metal. As will be explained later in more detail, the present invention allows forming backface 31 from a wide variety of hard materials. Backface 31 is preferably harder than the hardfacing material comprising layer 46, and is attached to outer portion 33 of base 30 without use of a filler material. Specifically, backface 31 may comprise a composition of material including tungsten carbide particles surrounded by a matrix of a copper, nickel, iron, or cobalt based alloy that is applied directly over substantially the entire outer portion 33. Acceptable alternative hardfacing materials include carbides, nitrides, borides, carbonitrides, silicides of tungsten, niobium, vanadium, molybdenum, silicon, titanium, tantalum, hafnium, zirconium, chromium or boron, diamond, diamond composites, carbon nitride, and mixtures thereof. For some application, tungsten carbide particles with the size range given in Table 1 may be used to form backface 31.
In accordance with an important aspect of the present invention as illustrated in the embodiments of both FIGS. 2 and 3, cutters 11 and 11" each have a composite cone body with respective bases 30 and 30" formed separately from tip 29. Bases 30 and 30" may include a nonheat-treatable hard metal component having a higher degree of hardness than found in prior rotary cone cutters. In contrast, conical tip 29 may be made of a conventional heat-treated steel. With this construction, cone backface 31 is better able to withstand both erosion and abrasive wear, thus not only providing enhanced protection of seal 43, but also serving to better maintain the gage diameter of borehole wall 17, particularly when drilling a deviated or horizontal borehole.
An important feature of the present invention is that tip 29 may be manufactured from any hardenable steel or other high-strength engineering alloy which has the desired strength, toughness, and wear resistance to withstand the rigors of the specific downhole application. In an exemplary embodiment, tip 29 is manufactured from a 9315 steel having a core hardness in the heat-treated condition of approximately HRC 30 to 45, and having an ultimate tensile strength of 950 to 1480 MPa (138 to 215 ksi). Other portions of cutter 11, such as precision bearing surfaces 39, may also be formed from this 9315 steel. In producing tip 29, the alloy is heat-treated and quenched in a conventional and well known manner to give tip 29 the desired degree of hardness.
An equally important feature of the present invention is that base portions 30 and 30" may be designed and fabricated from materials which enhance the service life of respective roller cone cutter 11 and 11" without limiting the performance of associated tip 29. In the illustrated embodiments of FIGS. 2 and 3, base 30 and 30" comprise a low-alloy steel core 32 onto which is affixed continuous layer or coating 49 of hard metal. A low-alloy steel typically has between approximately 2 and 10 weight percent alloy content. Core 32 may also be referred to as a "matrix ring." Core 32 is preferably a ring-shaped piece of the same material composition as tip 29, but of less expensive steel alloy which is not quench hardenable such as low carbon steel. In affixing layer 49, the exterior of steel core 32 is machined to size to receive the desired coating, and placed into a prepared mold (not shown) whose cavity is shaped to provide the desired coating thickness for layer 49 and frustoconical shape for outer portion 33.
For some applications, matrix ring or core 32 is an infiltrant alloy comprising Mn 25 weight percent, Ni 15 weight percent, Zn 9 weight percent, and Cu 51 weight percent. This alloy has good melt and flow characteristics, and good wettability for both tungsten carbide and steel. A typical hardfacing layer 49 may comprise between 20% and 40% infiltrant alloy by volume.
Techniques for the application of hardfacing layer 49 are well known in the art. One technique is an atomic hydrogen or oxyfuel welding process using a tube material containing ceramic particles in a Ni, Co, Cu or Fe based matrix. A second technique is the Thermal Spray or Plasma Transfer Arc process using powders containing ceramic particles in a Ni, Co, Cu or Fe based matrix. This technique is discussed in U.S. Pat. No. 4,938,991. Both the first and second techniques may be performed either by hand or by robotic welder. A third technique is disclosed in U.S. Pat. No. 3,800,891 (see columns 7, 8 and 9).
Alternatively, hardfacing layer 49 may be applied by a slurry casting process in which hard particles, such as the alternative hardfacing materials described for the preferred embodiment, are mixed with a molten bath of ferrous alloy. Alternatively, the molten bath may be of a nickel, cobalt, or copper based alloy. This mixture is poured into a mold and solidifies to form base portion 30. Grooves 12 may be molded during the application of hard facing layer 49, or may be cut into layer 49 after it has been applied to matrix ring 32.
The prepared mold for one embodiment is milled or turned from graphite. Each internal surface that will contact steel core 32 is painted with brazing stop off, such as Wall Colmonoy's "GREEN STOP OFF"® paint. Also painted are the surfaces of steel core 32 that will not be coated with hardfacing layer 49. Preferably, the mold is designed so that the thermal expansion of steel core 32 will not stress the fragile graphite mold parts.
Steel core 32 is assembled within the painted mold. The hard particles which form hardfacing layer 49 are then distributed within the mold cavity. TABLE 1 shows the sizes and distribution of the hard particles for the preferred embodiment.
TABLE I______________________________________U. S. Mesh Weight %______________________________________+80 0-3 -80 +120 10-18-120 +170 15-22-170 +230 16-25-230 +325 10-18-325 28-36______________________________________
Next, a vibration is applied to the mold to compact the layer of loose particles within the mold cavity. The infiltrant alloy is then placed in the material distribution basin above the hard particle layer in the cavity. If the infiltration operation is performed in an air furnace, powdered flux is added to protect the alloy. If the operation is performed in a vacuum or protective atmosphere, flux is not required.
In utilizing the mold, tungsten carbide powder or another suitable material is dispersed within the cavity to fill it, and an infiltrant alloy is positioned relative to the mold. Then the infiltrant alloy and the mold are heated within a furnace to a temperature at which the alloy melts and completely infiltrates the mold cavity, causing the carbide particles to bond together and to steel core 32.
Alternatively, base 30 can be made as a casting of composite material comprised of hard particles, such as Boron Carbide (B 4 C), Silicon Nitride (Si 3 N 4 ), or Silicon Carbide (SiC), in a tough ferrous matrix such as a high strength, low alloy steel, or precipitation hardened stainless steel. In the form of fibers or powders, these particles can reinforce such a matrix. This matrix may be formed either by mixing the particles with the molten alloy and casting the resultant slurry, or by making a preform of the particles and allowing the molten alloy to infiltrate the preform. Base 30 may be attached to tip 29 by inertia welding or similar techniques to form composite rotary cone cutter 11.
Once both base 30 (made in a manner other than the above-described composite-material casting process) and tip 29 are made, these two separate parts are joined together in a manner which is substantially non-destructive of the desirable characteristics of each. Preferably, they are joined together along a weld line 50 (FIG. 2) utilizing the process of inertia welding wherein one part is held rotationally stationary while the other is rotated at a predetermined speed that generates sufficient localized frictional heat to melt and instantaneously weld the parts together without use of a filler. This process employs a conventional inertia welding machine that is configured to allow variation of the rotating mass within the limitations of the machine's mass-rotating capacity and to rotate the mass at a controllable and reproducible rate. Once the rotating part is at the predetermined rotational speed, the parts are brought into contact with a predetermined forging force sufficient to completely deform a premachined circumferential ridge which is 0.191 inches wide and 0.075 inches high. The rotational speed is empirically determined with test parts of the same size, alloy, and prejoining condition. The complete deformation allows two planar facing surfaces on the parts being joined to come into contact.
In one example, base 30 having a volume of 4.722 cubic inches and a weight of 1.336 lbs. was successfully joined to a tip 29 having a volume of 16.69 cubic inches and a weight of 4.723 lbs. using a 44,000 lb. axial load and a rotational speed of 2200 rpm.
As best shown in FIG. 2, rotary cone cutter 11 may be formed by inertially welding base 30 with tip 29. A circumferential flange or ridge 112 may be provided on the interior of base 30 to engage with recess 114 formed in the adjacent portion of tip 29. Circumferential flange 112 cooperates with recess 114 to establish the desired alignment of base 30 with tip 29 during the inertial welding process. During later steps in the assembly of rotary cone cutter 11, elastomeric seal 43 may be disposed within recess 114.
FIGS. 4A-D show base portion 30, 130, 230 and 330 respectively which may be coupled with tip 29 as previously described to provide a composite cone cutter incorporating various alternative embodiments of the present invention. An important benefit of the present invention includes the ability to use same tip 29 with various base portions or backface rings. FIG. 4A is an enlarged drawing showing base portion or backface ring 30 as previously described with respect to composite cone cutter 11. Backface ring 30 includes opening 44 which is sized to be compatible with cavity 36 and to allow installation of spindle 23 within cavity 36 of associated cone cutter 11. Layer 49 of the desired hard facing material is preferably disposed on the exterior of outer portion 33 to form backface 31.
Backface ring 130 incorporating an alternative embodiment of the present invention is shown in FIG. 4B. Outer portion 33 of backface ring 130 includes a plurality of generally cylindrical shaped inserts 132. For one application, inserts 132 have a thickness or height of approximately 0.080". The thickness of inserts 132 is limited in part by the thickness of the associated matrix ring or steel core 32. Inserts 132 may be formed from various types of material such as sintered carbide, thermally stable diamonds, diamond particles, or any of the other materials used to form layer 49.
Backface ring 230 incorporating another alternative embodiment of the present invention is shown in FIG. 4C. A plurality of inserts 232 are provided in outer portion 33 of backface ring 230. Inserts 232 have a generally triangular cross-section as compared to the circular cross-section of inserts 132. Otherwise, inserts 232 may be fabricated from the same materials as previously described with respect to insert 132.
Backface ring 330 incorporating still another alternative embodiment of the present invention is shown in FIG. 4D. A plurality of inserts 332 are provided in outer portion 33 of backface ring 330. Inserts 332 may be natural diamonds and/or artificial diamonds which have been cast as an integral part of backface ring 330. Inserts 342 represent smaller diamonds or diamond chips cast as an integral part of backface ring 330. The present invention allows varying the size, location, and number of diamonds or diamond chips used to form outer portion 33 depending upon the intended use for the resulting rotary drill bit.
Although the present invention and its advantages have been described in detail, it should be understood that various changes, substitutions and alterations can be made therein without departing from the spirit and scope of the invention as defined by the appended claims.
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A rotary cone drill bit for forming a borehole having a body with an underside and an upper end portion adapted for connection to a drill string. The drill bit rotates around a central axis of the body. A number of angularly-spaced arms are integrally formed with the body and depend therefrom. Each arm has an inside surface with a spindle connected thereto and an outer shirttail surface. Each spindle projects generally downwardly and inwardly with respect to its associated arm, has a generally cylindrical upper end portion connected to the associated inside surface, and has an inner sealing surface on the upper end portion. A number of rotary cone cutters equal to the number of arms are each mounted on respective spindles. Each of the cutters includes an internal generally cylindrical wall defining a cavity for receiving the respective spindle, a gap with a generally cylindrical portion defined between the spindle and cavity wall, an outer sealing surface in the cavity wall concentric with the inner sealing surface, and a seal element spanning the gap and sealing between the inner and outer sealing surfaces. The rotary cone cutters are preferably composites formed from different types of material and have a ring base separately formed.
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CROSS-REFERENCE TO RELATED APPLICATIONS
This application claims priority to U.S. Provisional Patent Application No. 61/148,540 filed on Jan. 30, 2009, which is incorporated herein by reference.
FIELD OF THE INVENTION
The present invention relates to magnetic resonance imaging (MRI). In particular, the present invention relates to a method for image reconstruction that results in improved temporal resolution over those methods known to the art.
BACKGROUND AND SUMMARY OF THE INVENTION
Phase-contrast magnetic resonance imaging (PCMRI) is a method of encoding the velocity of particles traveling along a gradient field into the phase of the magnetic spin.
The velocity is encoded by applying appropriately designed gradient lobes in the velocity encoding direction; bipolar gradient lobes are one example. The two lobes of the bipolar gradient are created so their areas are equal and opposite. This makes the zeroth moment, m 0 , of the gradient waveform equal to 0 after the bipolar lobes. Since m 0 =0, no phase is imparted to static spins. Spins moving along the bipolar gradient direction experience a phase shift due to the difference in their positions from the first and second lobes of the bipolar gradient. This phase shift is proportional by the gyromagnetic ratio to the first moment, m 1 , of the bipolar gradient.
φ v =v*γ*m 1 (eq. 2)
Higher order motion such as acceleration, jerk, snap, crackle, and pop can be encoded using the higher order gradient moments m 2 , m 3 , m 4 , m 5 , and m 6 respectively. In practice, the bipolar gradient waveform used for velocity encoding can be overlapped with other waveforms in the pulse sequence such as ramp ups, ramp downs, and refocusing waveforms. This reduces echo times, repetition times, and scan times. Velocity encoding will be used to describe the invention due to its common use in clinical applications, although the invention may be used to improve temporal resolution in any technique that uses multiple encodings to generate a time series of images.
PCMRI sequences used for velocity encoding are designed with the m 1 used to encode the velocity into phase. The limitation placed on the velocity encoded phase is that it cannot exceed 360° without experiencing wrapping or aliasing in the image. When aliasing occurs, the same phase angle encodes for two or more velocity values. An aliased pixel value creates ambiguity on the true velocity as shown in FIG. 1 .
PC sequences for velocity encoding typically require an aliasing velocity, V ENC , to be input by the user. This value is used to set the m 1 such that the phase will not wrap and velocities between −V ENC and +V ENC will not be aliased. The range of non-aliased velocities are zero centered, allowing equally for velocities in the positive and negative directions. The range can also be shifted to allow for only positive velocities or only negative velocities or an arbitrary range. For further discussion, the zero centered range with limits ±V ENC will be used.
v→φ v (−180° to +180° range) (eq. 3)
One of the practical issues that has to be dealt with in PC imaging is an unknown background phase in an image. This background phase comes from a variety of sources (e.g. B 0 inhomogeneity, susceptibility differences, etc.) and varies across the image affecting the accuracy of the velocity measurement.
background
phase
from
static
tissue
=
ϕ
static
=
ϕ
s
(
360
°
range
)
(
eq
.
4
)
Because of the background phase on the image, PC requires an additional data separation step that is not required in standard data acquisition. To compensate for φ s , two complete datasets are acquired with some combination of φ s and φ v at each pixel. From these data sets φ s and Ø v can be separated and an image of phase due to velocity can be reconstructed. Standard data acquisition is as shown in FIG. 2 . PC data acquisition requires the additional data separation step shown in FIG. 3 .
As shown in FIG. 3 , variables a v,1 and a v,2 represent the weighting of the velocity into the measured phase in the data sets. When playing out the pulse sequence, a v,1 , and a v,2 are set by the m 1 of the appropriately designed velocity encoding gradients. These values have to be known so that the data may be separated later. The process can be analogized to the process of encoding a message which is to be sent. An encryption key is used by the sender to take the original message and convert it to the encrypted form. The key is later used by the receiver for decryption to yield the original message.
When each measured data set is reconstructed using the appropriate spatial encoding methods, each pixel of the phase image has phase that comes from three sources; velocity: (φ v ); static background tissue (φ s ); and noise (φ v ).
φ noise =φ n (eq. 5)
Currently two velocity encoding/decoding methods are commonly used: 1-sided and 2-sided encoding. 1-sided encoding collects two data sets: a velocity encoded, V enc , and velocity compensated, V 0 . The V 0 is assumed to be the first data set and the V enc is assumed to be the second data set. The order of the data can be switched. For the V 0 data, all of the phase in the measured data comes from the static background tissue and noise. The bipolar gradients are played out so there is no phase due to velocity.
φ 0 =φ s +φ n,0 (eq. 6)
An important point to note is the assumption that static background phase is assumed to be constant for the acquisition of both of the data sets. Noise varies between the data sets so it is denoted with a subscript on the acquisition in which it comes from.
For 1-sided encoding, the second acquisition is V enc data. For this acquisition the bipolar gradient is played out to so that a +V ENC velocity multiplied by a v,2 yields +180° of phase shift and a −V ENC velocity multiplied by a v,2 yields −180° of phase shift. The magnitude of a v,2 is set to prevent aliasing due to wrapping of the phase.
ϕ
enc
=
ϕ
v
+
ϕ
s
+
ϕ
n
,
enc
a
v
,
2
=
180
°
VENC
(
eq
.
7
)
The mapping of phase to velocity for the encoded and compensated images are shown in FIG. 4 .
Data separation is then performed by subtracting the velocity compensated data set from the velocity encoded data set to yield the phase due velocity. This subtraction cancels out the common phase due to static tissue while maintaining the velocity phase which is present in only the V enc data set.
ϕ
enc
-
ϕ
0
=
(
ϕ
v
+
ϕ
s
+
ϕ
n
,
enc
)
-
(
ϕ
s
+
ϕ
n
,
0
)
=
ϕ
v
+
ϕ
n
,
enc
+
ϕ
n
,
0
(
eq
.
8
)
The data is then reconstructed into an image where pixel intensity is set by the phase which is proportional to velocity. For simplicity, the magnitude of the complex signal has been ignored and only the phase retained. Due to the complex nature of the signal, there are multiple ways to perform the subtraction used for data separation. The phase difference method and complex difference methods are further discussed in the Handbook of MRI Pulse Sequences by Matt A. Bernstein, Kevin F. King, and Xiaohong Joe Zhou Elsevier, Academic Press, 2004 which is hereby incorporated by reference.
The other method which has been used is 2-sided encoding. 2-sided encoding is commonly used on General Electric (GE) MRI systems while SIEMENS has typically utilized 1-sided encoding. In 2-sided encoding the two data sets acquired are V − (data set 1) and V + (data set 2). Again the order is arbitrarily set, does not represent a required acquisition sequence, and can be changed. For the V − acquisition the bipolar gradient is played out to so that a +V ENC velocity multiplied by a v,1 yields −90° of phase shift and a −V ENC velocity multiplied by a v,1 yields +90° of phase shift. The smaller phase sensitivity to velocity used in the V − (and V + ) encoding is to prevent aliasing in the data separation step and is shown later.
ϕ
-
=
-
ϕ
v
2
+
ϕ
s
+
ϕ
n
,
-
a
v
,
1
=
-
90
°
VENC
(
eq
.
9
)
The V + acquisition is played out so the bipolar gradient so that a +V ENC velocity multiplied by a v,2 would yield −90° of phase shift and a −V ENC velocity multiplied by a v,2 would yield +90° of phase shift.
ϕ
+
=
+
ϕ
v
2
+
ϕ
2
+
ϕ
n
,
+
a
v
,
1
=
+
90
°
VENC
(
eq
.
10
)
Data separation is then preformed by subtracting the V − data set from the V + data set in the same way as 1-sided encoding to yield the phase due velocity.
ϕ + - ϕ - = ( + ϕ v 2 + ϕ s + ϕ n , + ) - ( - ϕ v 2 + ϕ s + ϕ n , - ) = ϕ v + ϕ n , + + ϕ n , - ( eq . 11 )
The mapping of phase to velocity for the positive and negative images are shown in FIG. 5 .
The need for reducing the sensitivity by half from the V enc to the V + /V − data sets comes from the subtraction of φ + and φ − . Even though a higher sensitivity wouldn't cause wrapping of the velocity phase in each of the data set, it could cause wrapping in the difference between the images. Therefore the sensitivity for each of the acquisitions in 2-sided has to be half the sensitivity of 1-sided.
Thus, conventional PC-MRI utilizes either a pair of velocity-encoded and velocity-compensated datasets or a pair of equal and opposite polarity velocity-sensitized k-space datasets. In either case, phase-difference or complex-difference reconstruction is performed on each complex data pair to eliminate any residual non-zero phase variation due to effects other than velocity. Conventional PC-MR velocity mapping requires twice as much data as standard MRI scans. This requirement either degrades the temporal sampling rate by a factor of two, or doubles the acquisition time in order to maintain temporal resolution.
Cardiac echo-sharing has been utilized to improve the effective temporal resolution in segmented cine and phase-contrast imaging. In echo-sharing, portions of k-space are shared between adjacent images for both velocity-compensated and velocity-encoded lines. Therefore, partial k-space data is shared and reconstructed from two or more temporally adjacent k-space data pairs. Because image characteristics are dominated by the central portion of k-space, echo-sharing methods require the acquisition of an additional central line or segment of k-space for each pair of reconstructed frames. Otherwise, if the central lines of k-space were shared between frames, those frames would contain substantially the same information.
The present invention of Shared Velocity Encoding (SVE) reconstruction can be used to increase the effective temporal resolution of PC-MRI. In conventional PC-MRI reconstruction, the phase difference is calculated from consecutive pairs of (+ −) velocity encoded k-space lines. Thus, if the total number of acquired k-space lines is N, the resulting number of reconstructed phase-difference lines is N/2. In contrast, the SVE PC-MRI method of the present invention shares data between consecutive images. By doing so, N−1 phase-difference lines from alternate polarity pairs (+ −), (− +), (+ −), etc., can be constructed from the N acquired k-space lines. The result is that the effective temporal resolution is increased by a factor of 2.
SVE reconstruction provides for improved methods of MRI blood flow velocity mapping. Additionally, the very high temporal resolution data acquisition necessary for MRI pulse wave velocity (PWV) measurement—that is not exhibited by the traditional methods of PC-MR imaging—is enabled by SVE reconstruction. Conventional MRI flow quantification methods require the acquisition of additional reference data to account for errors in the signal phase. SVE reconstruction eliminates the temporal resolution penalty associated with the acquisition of this additional reference data. The SVE reconstruction method can be combined with a segmented EPI readout to achieve high temporal resolution real-time velocity mapping by minimizing sensitivities to respiratory and cardiac motions. More benefits and additional applications of SVE reconstruction will become apparent upon review of the figures and detailed description that follows.
BRIEF DESCRIPTION OF THE DRAWINGS
FIG. 1 shows a magnitude (anatomical) image (left) and a phase difference (velocity) image (right) of a bicuspid aortic valve (highlighted with yellow circle). The two black dots are wrapped velocities which have exceeded the V enc
FIG. 2 is a diagram showing how a MRI with traditional magnitude reconstructed image is produced.
FIG. 3 is a diagram showing how a MR phase contrast reconstructed image is produced.
FIG. 4 is a diagram showing the relationship between velocity and phase ranges for V enc and V 0 .
FIG. 5 is a diagram showing the relationship between velocity and phase ranges for V + , V − , and their difference.
FIG. 6 is a diagram showing 1-sided image reconstruction from k-space data.
FIG. 7 is a diagram showing 2-sided image reconstruction from k-space data.
FIG. 8 is a diagram showing shared velocity encoding (SVE) image reconstruction from k-space data.
FIG. 9 is a diagram showing 1-sided shared velocity encoding where reused k e images are redundant since they contain no new velocity information.
FIG. 10 is a diagram showing 1-sided encoding: image weighting over time.
FIG. 11 is a diagram showing 2-sided encoding without SVE: image weighting over time.
FIG. 12 is a diagram showing 2-sided encoding with SVE: image weighting over time.
FIG. 13 shows a table summary of window length in units of k-space.
FIG. 14 is a scheme showing spoiled gradient-echo phase contrast pulse sequence for one-directional velocity encoding along the slice-selection direction using a pair of velocity-compensated and velocity encoded gradients.
FIG. 15 shows a diagram of 1-Sided Encoding: EPI with 4 echo trains/k-space
FIG. 16 shows a diagram of 2-Sided Encoding with SVE:EPI with 4 echo trains/k-space
FIG. 17 shows a diagram of 1-Sided Encoding, Sharing ¼ of K-Space (nearest neighbor)
FIG. 18 shows a diagram of 2-Sided Encoding with SVE, Sharing ¼ of K-Space (nearest neighbor)
FIG. 19 shows a diagram of 1-Sided Encoding, Sharing ¼ of K-Space (linear interpolation)
FIG. 20 shows a diagram of 2-Sided Encoding with SVE, Sharing ¼ of K-Space (linear interpolation)
FIG. 21 shows a diagram of 3D velocity encoding with 1-sided.
FIG. 22 is a diagram showing equally spaced velocity encoding direction for 2-sided encoding.
FIG. 23 is a diagram showing 3D velocity encoding with SVE.
FIG. 24 is a scheme showing spoiled gradient-echo phase-contrast pulse sequence for one-directional velocity encoding along the slice-selection direction using a pair of equal and opposite polarity velocity-sensitized gradients.
FIG. 25 is a scheme showing conventional non-segmented PC-MRI reconstruction.
FIG. 26 is a scheme showing non-segmented PC-MRI with bipolar VENC and SVE reconstruction.
FIG. 27 is a diagram showing the cardiac view-sharing PC-MRI method.
FIG. 28 is a diagram showing the cardiac shared velocity encoding PC-MRI method.
DETAILED DESCRIPTION
Conventional phase-contrast MR images are commonly acquired using a spoiled gradient-echo sequence combined with a pair of velocity-sensitized gradients on one or more gradient axes. There are two basic approaches to achieving quantitative and qualitative velocity measurement by PC-MRI. As shown in FIG. 14 , one technique (1-sided) employs a pair of velocity-compensated and velocity-encoded gradients to eliminate background phase variations. As shown in FIG. 24 , the other technique (2-sided) employs equal and opposite polarity velocity-sensitized gradients to eliminate background phase variations. Subtraction of two datasets is performed to eliminate residual non-zero phase shifts that stem from undesired phase variation other than motion, such as field inhomogeneity, eddy currents, and magnetic susceptibility. However, the additional acquisition of a phase-reference, which typically interleaves with the velocity-encoding dataset, reduces the temporal resolution as compared to standard cine image scans.
To reduce the effects of background phase variations, and other unwanted contributions to the phase, two consecutive images are acquired. A pixel-by-pixel phase subtraction is performed to determine the difference in phase in these two images. In this manner, quantitative measurement of blood flow can be estimated from the phase difference between two velocity-sensitized datasets. Both conventional PC-MRI approaches require additional phase information that doubles the amount of data required relative to other MRI pulse sequences. As the result, PC-MRI requires either extended scan time or sacrifices in spatial and temporal resolution that make real-time flow quantification and three-dimensional acquisition impractical.
SVE is a novel PC-MRI reconstruction technique that improves temporal resolution by reusing adjacent k-space data to reconstruct twice as many frames as conventional PC-MRI reconstruction methods. As previously mentioned, one type of conventional PC-MRI method works by alternating the polarity of velocity encoding gradients from one k-space to the next between positive [+] and negative [−] velocity encoding (i.e., [+ −], [+ −]) as shown in FIG. 25 .
The velocity map is obtained by subtracting the negative velocity encoded image from the positive encoded k-space data. The temporal resolution of the velocity map is therefore half the image frame rate. In the conventional PC-MRI method, the phase-contrast images are calculated from consecutive pairs of [+ −] velocity encoded lines. This results in N/2 reconstructed temporal-phase images from N acquired full k-space datasets as shown in FIG. 25 . In SVE, data are acquired in the same way, but the velocity map is reconstructed by sliding the pair of images for subtraction one frame at a time (instead of two), resulting in a factor of 2 improvement in effective temporal resolution as is shown in FIG. 26 . Using SVE, velocity-sensitized data is reconstructed between consecutive images with alternate polarity velocity encoding. As a result, N−1 phase-difference lines from alternate polarity pairs (i.e. [+ −], [− +], [+ −]), etc., can be reconstructed from N acquired lines, resulting in nearly a factor of 2 increase in effective temporal resolution. As shown in FIG. 26 , the odd numbered reconstructed phases 100 are equivalent to conventional phase-different reconstruction while the additional intermediate even-numbered phases 110 are generated by SVE reconstruction.
Due to the need for two data sets to determine the phase due to velocity and background phase, the temporal resolution of PC-MRI sequences is half that of imaging methods that require just one data set. For 1-sided encoding, the typical data acquisition and image reconstruction is shown in FIG. 6 with k's representing complete k-spaces.
As shown in FIG. 6 , the first image is reconstructed from the 1 st k e and 1 st k 0 . The second image is reconstructed from the 2 nd k e and 2 nd k c and so on. Notice that the images are centered with the center of k e which are used in the reconstruction verses being centered between k e and k 0 . This is because the velocity information completely from the k e data set and the k 0 provides information about the background phase but not velocity which is represented in the reconstructed phase image.
2-sided acquisitions are typically reconstructed as shown in FIG. 7 . The first image is reconstructed from the 1 st k + and 1 st k − . The second image is reconstructed from the 2 nd k + and 2 nd k − and so on. Notice that the images are centered between k + and k − which are used in the reconstruction. This is because half the velocity information comes from k + and half from k − .
Shared velocity encoding (SVE) method reconstructs images which share positive and negative encodings that are measured from 2-sided encoding. Additional images are reconstructed between the 2 nd k + and 1 st k − , 3 rd k + and 2nd k − , and so on as shown in FIG. 8 . This novel method restores temporal resolution which is typically lost with standard PC. Two data sets are always needed for the data separation step: one which uniquely identifies the background phase and one which identifies the phase due to velocity. Previously known PC methods have ignored the two data sets after the data is separated. As SVE travels through time separating the data, it is able to recycle the later data set in its next separation. By recycling this data set, SVE is able to boost its temporal resolution to two times that of standard PC methods.
In SVE, data are acquired in the same way, but the velocity map is reconstructed by sliding the pair of images for subtraction one frame at a time (instead of two). Using SVE, velocity-sensitized data is reconstructed between consecutive images with alternate polarity velocity encoding. As a result, N−1 phase-difference lines from alternate polarity pairs (i.e. [+ −], [− +], [+ −]), etc., can be reconstructed from N acquired lines.
Under the assumption that the background phase is constant or slowly changing, recycling can be used with 2-sided encoding but not with 1-sided encoding. With 2-sided encoding, k + and k − data sets can be reused because both of the data sets contain velocity information encoded into their phases. As shown in FIG. 9 , recycling cannot be used in 1-side encoding because the k e data set contains all of the velocity information. If k e data sets were shared across two k 0 data sets, the two resulting images would be nearly identical because the velocity information would be identical. Only temporal changes in the background phase would be accounted for.
Although a two-fold improvement in temporal resolution seems advantageous, thorough investigation of SVE has been performed to ensure other performance characteristics are not being detrimentally affected. Three methods were examined: 1-sided encoding, 2-sided encoding without SVE, and 2-sided encoding with SVE. Evaluation focused on constant velocity assumption. One application of PC is to the measurement of blood velocity in vessels. Velocity of blood follows the pulsitile nature of a beating heart. This variation violates the constant velocity assumption in PC introducing an error. The error caused by the changing velocity with the three different methods was investigated.
To start, an understanding is gained of the origin of velocity data in time for images in 1-sided, non-SVE, and SVE. The image weighting over time for 1-sided encoding is shown in FIG. 10 .
An important characteristic which can be seen from this graphic is the image sampling window length. The window length is the amount of time over which the velocity information is acquired. Time is defined in the amount needed to collect one k-space data set. The analysis is kept general by making it independent of factors such as gradient performance, T* 2 decay (EPI limit on train length), and segmentation which affect the amount of time it takes to acquire k-space data sets. Time is normalized to the k-space acquisition time. For 1-side the window length is 1 k-space. The image weighting over time for 2-sided encoding without SVE is shown in FIG. 11 .
For the 2-sided encoding without SVE, the graphic reveals the window length is 2 k-space, twice as much as 1-sided. A longer window length is undesirable. The sampling window has an averaging effect over time. For a constant velocity this does not have any effect, but with a varying velocity the window smoothes the velocity curve by acting as a low pass filter. This smoothes rapidly changing features in the velocity curve such as peaks and valleys. To see if 2-sided encoding with SVE has this same characteristic, the image weighting over time is illustrated in FIG. 12 .
Like non-SVE, SVE has the longer 2 k-space window length. The improved temporal resolution can be seen also, but this improvement does not come without drawbacks. Further investigation has to be performed to evaluate the effects of sample window length and temporal resolution on accuracy of 1-sided encoding, 2-sided encoding without SVE, and 2-sided encoding with SVE as can be seen in FIG. 13 .
SVE does not alter true temporal resolution because it requires the same acquisition period to collect k-space data for each temporal cine-frame; two temporal cine-frames are used to calculate each velocity map. Both temporal cine-frames contribute equally to the velocity measurement at each time point. When velocity compensated data is used as the phase reference, only the velocity-encoded frames contribute to the measured velocity.
SVE is able to reuse the information from each of its k-space data sets because they both contain velocity information. 1-side encoding is not able to reuse its data since the velocity compensated data set contains no information about velocity. This reuse of data utilized by SVE is somewhat similar to view sharing yet there are critical differences between the two methods. The definition used for view sharing is a reconstruction method that reuses portions of the k-space data in order to reconstruct two or more different images, as set forth by Bernstein in his 2004 book “Handbook of MRI Pulse Sequences”.
K-space echo-sharing or view-sharing has been utilized as a means of improving the effective temporal resolution in segmented cine and phase-contrast imaging. Unlike echo-sharing, SVE collects a full k-space of data with a given velocity sensitivity followed by another k-space with an opposite velocity sensitivity while the echo-sharing method shares portions of k-space between adjacent images for both the velocity compensated and velocity encoded lines. Therefore, in the echo-sharing method, partial k-space data is shared and reconstructed from two or more temporally adjacent k-space data pairs, as shown in FIG. 27 . SVE, on the other hand, does not share parts of k-space with adjacent phases, but instead shares half of the data (V+ or V−) needed for PC-MRI reconstruction as shown in FIG. 28 . There are several important differences between SVE and echo-sharing that influence velocity measurements and the applicability of each technique due to difference in the ordering of k-space.
Image characteristics are dominated by the central portion of k-space, echo-sharing methods require the acquisition of an additional central line or segment of k-space for each pair of reconstructed frames. Otherwise, if the central line(s) of k-space were shared between frames, those frames would contain substantially the same information. SVE does not require the acquisition of additional central lines; each frame has a unique combination of central line encodings (V+ and V−), and thus unique velocity information. In segmented acquisitions the smaller the number of segments the less efficient echo-sharing methods are due to the requirement of acquiring additional center lines. In the extreme case of one line per segment, or non-segmented acquisition, echo-sharing fails to provide any gain in temporal resolution while SVE can be successfully applied. As the number of segments increases, the efficiency of echo-sharing increases also, to the extreme of real-time imaging where typically only a single central line of k-space must be acquired uniquely for each image. However, in the particular implementation of real-time PC-MRI using a segmented echo-planar readout, echo-sharing would require the acquisition of an additional echo-train per encoded image, i.e., one for the V+ encoding and one for the V− encoding. This would result in a significant loss in efficiency when compared with SVE which requires no additional data or echo trains to ensure that each reconstructed frame has unique central k-space information.
The data which is being collected has two pieces of information, the velocity and the background signal. The complete process involves data acquisition, separation (i.e. phase difference reconstruction), and image reconstruction (including Fourier Transform, view sharing, etc.).
In some embodiments, SVE is not a substitute for other techniques used in velocity encoding but rather can be used in conjunction with one or more of the known techniques. In these embodiments, SVE may be used with other performance enhancing techniques to further extend the performance of an SVE sequence. For example, the SVE method can be combined with echo-sharing for additional gains in temporal resolution. SVE may be used with one or a combination of the following:
Gradient echo
Spin echo
EPI: echo planar imaging
View Sharing (including but not limited to retrogating, prospective
gating, interpolation, nearest neighbor interpolation, linear
interpolation, image space interpolation,
k-space space interpolation, sliding window)
RF pulses (including but not limited to spatial selective
1/2/3D, spectral pulse, adiabatic)
Correction gradients
Physiological gating, triggering, and monitoring
Parallel Imaging
Multiple receive coil or transmit coils
Tagging
Data acquisition (including but not limited to spiral, radial, propeller)
Inversion recovery (single or multiple)
Phase difference reconstruction
Complex difference reconstruction
Any difference reconstruction algorithm
This table provides only some of the possible techniques compatible with SVE and does not represent a comprehensive list.
To show some of the compatible techniques, EPI and view sharing methods (nearest neighbor and linear interpolation) are shown with 1-side encoding and SVE in FIGS. 15 through 20 .
The shared-encoding strategy of SVE is also not limited to velocity encoding. The phase can also be used to encode other information. The novel technique could also be used to encode acceleration, jerk, or higher order motion. It can also be used to encode cyclical motion. Any piece of information which can be encoded into phase differentially between two data sets can utilize the reuse of one of the data set to increase temporal resolution without increasing the sample window length.
Sharing of data can also be done over more than two data sets. If information is encoded differently in more than two data, then information in each data set can be reused. For example, if three data sets contained information encoded in a different manner for each data set, then the first combination could be 1-2-3 followed by 2-3-1 (where data set 1 is acquire after dataset 3), and then 3-2-1. Data set could also be a single point, 1 dimensional, 2 dimensional, or generally any dimension or configuration.
An example of a more than two encodings is 3D velocity encoding. This is where velocity is encoded in the x, y, and z directions. As an example of 1-sided encoding, x direction velocity could be encoded in k X , y direction velocity in encoding k Y , z direction velocity in encoding k Z , and a velocity compensated in encoding k 0 . Three more images could be reconstructed each time an additional set of each encoding is collected ( FIG. 21 ). As an example of 2-sided encoding with 3D velocity encoding, four equally spaced encoding directions are established as shown by FIG. 22 .
Data is encoded into the four directions k 1 , k 2 , k 3 , and k 4 . Four more images could be reconstructed each time an additional set of each encoding is collected as shown by FIG. 23 .
One novel feature of the sharing technique of the present invention, is the ability to update a single encoding instead of having to update both of the encodings. PC-MRI requires data with two different velocity encodings. The phase due to velocity in each encoding is different which allows for separation of the phase due to velocity from the background phase. The novelty of SVE is the ability to share data by updating data from only one of the two encodings instead of having to update both encodings. This allows for better temporal resolution. 1-sided encoding cannot take advantage of this updating strategy because the velocity compensated image contains no velocity information. 2-side velocity encoding can take advantage of this strategy but it has not been realized until now.
This advantage to update encoding more rapidly can be expanded to more than two encodings such as 3D encoding. In 3D encoding, 1-sided velocity encoding can even take advantage of the sharing to a degree. For 1-sided 3D encoding, sharing can allow for the update of k X , k Y , and k Z only but it cannot allow the update of only k 0 because this encoding contains no information of velocity. In 3D encoding, 2-sided velocity encoding also takes advantage of the sharing to a degree. For 2-sided 3D encoding, sharing can allow for the update of k 1 , k 2 , k 3 , and k 4 only. Although these improvements do not allow for true temporal resolution to be improved by 3 times for 1-sided and 4 times for 2-sided, some improvement in performance exists.
This sharing technique is also not limited to velocity information or information encoded into the phase of the image; the technique generally applies to any method of dynamic or multi-frame imaging that utilizes two or more encodings. It can be used in any method utilizing multiple encodings of information and acquiring multiple time frames. Magnitude is also use to differentially encode data. Sharing encoding could improve temporal resolution. Sharing could improve BOLD imaging. BOLD imaging utilizes differences in the magnitude of the signal which depend on the blood oxygen concentration. Some of these methods which could be improved with the novel sharing technique are but not limited to:
Displacement encoding (DENSE)
Velocity encoding
Acceleration encoding
Higher order motion encoding
Cyclical motion encoding
Diffusion tensor
BOLD
T1 encoding
T2 encoding
T2* encoding
Arterial spin tagging
Phase sensitive inversion recovery
Phase contrast angiography
Dixon method
Resonance separation (general form of Dixon method)
While certain embodiments of the present invention are described in detail above, the scope of the invention is not to be considered limited by such disclosure, and modifications are possible without departing from the spirit of the invention as evidenced by the following claims:
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An exemplary embodiment of the present invention includes a method for increasing temporal resolution in Phase Contrast (PC) MR imaging. The increased temporal resolution may be obtained by reusing information encoded into phase of an MRI signal where said reuse occurs prior to the difference reconstruction.
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ORIGIN OF THE INVENTION
The invention described herein was made jointly in the performance of work under a NASA contract and is subject to the provisions of Section 305 of the National Aeronautics and Space Act of 1958, Public Law 85-568 (72 Stat. 435; 42 USC 2457).
CROSS REFERENCE
This application is a continuation in part of our application Ser. No. 07/410,572, filed Sept. 21, 1989, now abandoned.
BACKGROUND OF THE INVENTION
1. Field of the Invention
This invention relates to structural resins and in particular to the process of forming solid polyamic acid and polyimide fibers by wet spinning, whereby fibers with excellent chemical resistance, high thermal stability, and tensile properties in the range of standard textile fibers are produced.
2. Description of the Related Art
Linear aromatic polyimides are finding increased usage in industrial and aerospace applications due to their excellent chemical resistance and high temperature stability. They are mainly used in film form, as coatings and composite matrix resin. Various patents and articles have described the formation of aromatic polyamic acid and polyimide fibers, but little commercial development has resulted. Recently, Lenzig AG reported the production of a commercially available aromatic copolyimide fiber P84 using a special dry spinning and finishing process (Proc. 2nd Inter. Conf. Polyimides 1985, 253-271). The main advantages of P84 compared to other high performance fibers are reportedly its outstanding non-flammability, long term thermal stability, non-melting behavior, and excellent chemical resistance to acids and organic solvents. These properties are common to most aromatic polyimides. Suggested applications for this type of fiber are protective clothing, sealing materials, filtration in harsh chemical and/or high thermal environments, and various other textile uses where fire-resistant properties are required.
Production of aromatic polyamic acid fibers by the extrusion of a polyamic acid resin solution into a liquid coagulation medium was reported (U.S. Pat. No. 3,179,614) as early as 1965. The aromatic polyamic acid is generally formed in aprotic organic solvents such as N,N-dimethylformamide (DMF), N,N-dimethylacetamide (DMAc), dimethylsulfoxide (DMSO), and N-methylpyrrolidione (NMP) at concentrations of between 0.05 and 40% solids (w/w). Resin inherent viscosities were found to vary from 0.1 to 5.0 dl/g. Mono-, di-, or trihydric alcohols, or mixtures thereof, or aqueous solutions, or acetone solutions of said alcohols, aqueous solutions of aprotic organic solvents, and thiocyanate or sulfur salts in aqueous DMAc have been used as coagulation media. No disclosure has been found of the production of totally void free solid aromatic polyamic acid fibers that do not contain macropores or voids.
SUMMARY OF THE INVENTION
One object of the present invention is to provide a process for the production of solid aromatic polyamic acid fibers.
Another object of the present invention is to provide a process for the production of solid aromatic polyamic acid fibers from wet gel or coagulation bath wet gel.
Another object of the present invention is to provide a process for the production of solid aromatic polyamic acid fibers using DMAc solutions of the polyamic acid derived from 3,3',4,4'-benzophenonetetracarboxylic dianhydride (BTDA) and 4,4'-oxydianiline (4,4'-ODA).
Another object of the present invention is to provide a process for the production of solid polyamic acid fibers which utilizes the interrelationship between coagulation medium composition and concentration, resin inherent viscosity, resin % solids, filament diameter, and fiber void content.
Another object of the present invention is to provide a process for producing solid polyimide fibers.
Another object of the present invention is to produce polyamic acid and polyimide fibers that will be useful for both industrial and aerospace applications requiring fibers with excellent chemical resistance, high thermal stability, and tensile properties in the range of standard textile fiber, such as protective clothing, sealing materials, filtration in harsh chemical and/or high thermal environments, and various other textile uses where fire-resistant properties are important.
By the present invention, solid aromatic polyamic acid fibers have been produced using DMAc solutions of the polyamic acid derived from BTDA and 4,4'-ODA with either 70-75% aqueous ethylene glycol or 70-80% aqueous ethanol as the coagulation medium. Polyimide fibers, obtained by the thermal cyclization of the polyamic acid precursor, were found to exhibit enhanced tensile properties compared to fibers containing macropores from the same resin system. A chemical curing will also provide solid polyimide fibers. It is anticipated that these fibers will be useful for both industrial and aerospace applications requiring fibers with excellent chemical resistance, high thermal stability, and tensile properties in the range of standard textile fibers.
The success of the present invention is acquired by the use of the interrelationship between coagulation medium composition and concentration, resin inherent viscosity, resin % solids, filament diameter, and fiber void content to produce solid aromatic polyamic acid fibers. The general requirements for the production of solid coagulation bath fibers from a DMAc solution of the BTDA/4,4'-ODA polyamic acid are for the resin to have a minimum inherent viscosity of about 1.6 dl/g and at least approximately 15% solids. The coagulation bath should consist of either 70-75% aqueous ethylene glycol or 70-80% aqueous ethanol at temperatures near 20° C. Coagulation bath fiber diameters should be kept less than 50 microns.
Although other factors such as coagulation bath temperature, concentration and temperature of the wash bath, and wet gel drying conditions are known to effect the production of solid filaments in other fiber systems, these factors did not appear to significantly affect void formation in the fibers of the present invention.
BRIEF DESCRIPTION OF THE DRAWINGS
FIG. 1 is a schematic showing of commonly used Fiber Wet Spinning Equipment.
FIG. 2 shows examples of fibers with and without voids using SEM photos of fractured ends of coagulation bath fibers. FIG. 2A is a polyamic acid filament from a system where the aqueous coagulation medium was 60% ethanol and there was a resin inherent viscosity of 1.3 dl/g. FIG. 2B is a polyamic acid filament from a system where the aqueous coagulation medium was 70% ethanol and the resin inherent viscosity was 1.3 dl/g. FIG. 2C is a polyamic acid filament prepared according to the process of the present invention where the aqueous coagulation medium was 70% ethanol and the resin inherent viscosity was 1.6 dl/g.
DESCRIPTION OF THE PREFERRED EMBODIMENTS
Aromatic polyamic acid fibers were produced using the equipment shown in FIG. 1, purchased from an outside source. A polyamic acid resin was poured into stainless steel extrusion cylinder/piston assembly 2 and extruded through a spinnerette immersed in liquid coagulation bath 4. The solidifying filament was drawn through liquid coagulation bath 4 and onto cluster rolls 6. The filament then traveled through water wash bath 12, over second set of cluster rolls 8, and onto a pyrex or stainless steel spool on winder 10. Polyamic acid filaments collected at this point that have not been dried are termed "wet gel," versus those collected from the first set of cluster rolls termed "coagulation bath wet gel." Drying of the filaments was carried out either in a forced air or vacuum oven. After drying, the polyamic acid fibers were converted to polyimide fibers by further heating in a forced air oven.
Although this work concentrated on the spinning conditions required to produce solid filaments from the polyamic acid resin derived from BTDA and 4,4'-ODA, solid filaments may possibly be obtained from other polyamic acid resins by modifying certain of the spinning conditions to be discussed next. Coagulation medium composition and concentration, resin inherent viscosity, resin % solids, and filament diameter are all interrelated as to their effect on the production of solid coagulation bath wet gel. Washing and drying of the coagulation bath wet gel generally does not cause the formation of significant voids within the filament as long as care is taken to assure "good collapse" or consolidation of the wet gel structure during drying to fiber form. Therefore, this process concerns the production of solid coagulation bath fiber.
Fiber void content was determined by the visual inspection of at least eight fractured fiber ends using either an optical or scanning electron microscope (SEM) and reported as "% solid fibers." A value of "100" signifies that all the fibers examined were solid, whereas a value of "50" indicates only half of the fibers examined were solid.
Resin inherent viscosity, resin viscosity, and % solids were varied during the formation of the polyamic acid resin. The % solids are determined by the weight of the monomers and DMAc solvent used during the polymerization process. Resin inherent viscosity is determined by the polymerization reaction and can be influenced by the molar ratio of the monomers, purity of the monomers and solvent, percent solids, and reaction temperature, as well as time. It was measured at 0.5 percent solids (w/w) in DMAc at 35° C. It was generally found that the production of solid coagulation bath fibers required a minimum resin concentration of approximately 15% solids and a minimum inherent viscosity of about 1.6 dl/g (see Tables I and II). Spinning of resins with greater than 15% solids and inherent viscosities above 1.6 dl/g have not been attempted in this work because the resins are so viscous that extrusion would be difficult. However, if conditions could be modified to allow extrusion using concentrations above 15% solids and inherent viscosities above 1.6 dl/g, solid fibers could forseeably be produced. Resin viscosity was measured using a Brookfield viscometer at ambient temperature. Measurement of resin viscosities indicated that a high resin viscosity would not result in solid fibers unless the inherent viscosity and % solids were also at acceptable levels. However, if the resin viscosity was lower than 40 poise at 24° C. with 15% resin solids and the filament diameter was near 50 microns, the coagulation bath fibers always contained voids.
TABLE I______________________________________70% Aqueous Ethylene Glycol Coagulation BathResin Inherent FiberViscosity Resin Diameter % Solid(dl/g) % Solids (Microns) Fibers______________________________________1.1 20.0 41 01.3 20.0 84 801.2 15.0 54 01.3 14.5 50 111.6 14.5 64 951.6 14.5 45 1001.6 14.5 31 1001.9 15.0 63 1002.1-1.6 9.7 47 75______________________________________
TABLE II______________________________________Aqueous Ethanol Coagulation Bath Resin Inherent Fiber% Aqueous Viscosity Resin Diameter % SolidsEtOH (dl/g) % Solids (Microns) Fibers______________________________________80 1.3 14.5 34 10080 1.6 14.5 55 8380 1.6 14.5 35 10070 1.3 14.5 28 7370 1.6 14.5 54 10070 1.6 14.5 33 10070 1.1 20.0 37 6060 1.3 14.5 48 0______________________________________
Ethylene glycol (EtG), ethanol (EtOH), and aqueous solutions of either EtG or EtOH were investigated as coagulation media to produce solid core fiber. Solid coagulation bath fibers were obtained using either 70-75% aqueous EtG or 70-100% aqueous EtOH. A value of 70% aqueous EtOH signifies 70 grams of EtOH mixed with 30 grams of water. However, concentrations greater than 80% aqueous EtOH and 75% aqueous EtG tended to cause the filament in the coagulation bath to spiral as it exited the spinnerette and then sway back and forth in the bath until it contacted the first set of cluster rolls. This is a very fragile and unstable state at which to produce filaments; it is termed "poor spinnability," and conditions that caused this state were generally avoided.
Filament diameter is also important for the production of the solid coagulation bath fibers of the present invention. It is determined by the resin % solids, rate of resin extrusion, size and number of holes in the spinnerette, and the difference in velocity between the resin stream as it exits the spinnerette and the roll surface of the first set of cluster rolls, termed "jet stretch." The rate of resin extrusion depends on the volume of the extrusion cylinder/piston assembly and the velocity of the piston as it moves into the cylinder. Spinnerettes used in this work all had a single hole of either 50 or 100 microns in diameter. Filament diameters are reported as the average of at least six measurements from SEM photos of fractured fibers ends. The production of solid coagulation bath fibers from resins with inherent viscosities of less than 1.6 dl/g could be achieved if conditions were chosen such that diameters much less than 50 microns were obtained. Whereas, solid coagulation bath fibers having diameters in excess of 50 microns could be obtained from resins with inherent viscosities in excess of 1.6 dl/g (see Tables I and II).
Although other factors such as coagulation bath temperature, concentration and temperature of the wash bath, and wet gel drying conditions are known in other fiber systems to effect the production of solid filaments, these factors did not appear to significantly effect void formation in the fibers of the present invention. The coagulation bath temperature was varied from 0° to 30° C. while the pure water wash bath was held at 30°-31° C. Temperatures in excess of 31° C. were not investigated in order to minimize hydrolysis of the polyamic acid. Drying for between 15-18 hours was carried out at 80°-85° C. also to minimize the possibility of hydrolysis during collapse and removal of water/DMAc/EtG or EtOH from the liquid swollen wet gel. Both forced air or vacuum (at 30 inches of Hg) drying did not appear to cause void formation (see Table III).
TABLE III______________________________________Drying of Coagulation Bath Wet GelCoagulation 80° C., 80°, FiberBath Air Oven Vac Oven Diameter FiberComposition 15-18 hours 15-18 hours (Microns) % Solids______________________________________70% Aqueous yes 35 100ethylene glycol70% Aqueous yes 35 100ethylene glycol80% Aqueous yes 36 100ethanol80% Aqueous yes 35 100ethanol______________________________________
It must therefore be concluded that the success of the present invention is attained by the use of the interrelationship between coagulation medium composition and concentration, resin inherent viscosity, resin % solids, filament diameter, and fiber void content to produce solid aromatic polyamic acid fibers. The general requirements for the production of solid coagulation bath fibers from a DMAc solution of the BTDA/4,4'-ODA polyamic acid are for the resin to have a minimum inherent viscosity of 1.6 dl/g and at least 15% solids. The coagulation bath should consist of either 70-75% aqueous EtG or 70-80% aqueous EtOH at temperatures near 20° C. Coagulation bath fiber diameters should be kept less than 50 microns.
Although the polyamic acid fibers were thermally imidized, polyimide fibers could also be created by passing the polyamic acid fibers through a solution containing pyridine and acetic anhydride to chemically cyclize the imide ring.
EXAMPLES
Example 1
This Invention
To a two liter resin kettle was added 55.69 g of 4,4'-oxydianiline (4,4'-ODA) and most of 854.70 g of dry N,N-dimethylacetamide (DMAc). The kettle was then purged with dry nitrogen, and stirring was begun and continued until all the 4,4'-ODA dissolved in the DMAc. A total of 89.61 g of 3,3',4,4'-benzophenonetetracarboxylic dianhydride (BTDA) (vacuum dried for 20 hours at 150° C.) was added at once, with any residual BTDA being washed into the reaction solution using the remaining DMAc, the reaction vessel was again purged with dry nitrogen, and stirring was resumed. The reaction was allowed to continue under a constant flow of dry nitrogen for between four to six hours at ambient temperature. The inherent viscosity of the resulting polymer was determined to be 1.6 dl/g at 35° C., with a corresponding Brookfield or resin viscosity of 572 poise at 24.7° C. The resulting polyamic acid solution (14.5% solids) was refrigerated until used for fiber spinning.
The resin was poured into the extrusion cylinder/piston assembly and allowed to stand at 35° C. until all the entrapped air migrated out of the solution. The remaining parts of the extrusion assembly and spinnerette (one hole with 100 micron diameter) were attached and resin extruded at a rate of 0.098 ml/min for several minutes to remove any residual air in the system. The spinnerette was then immersed in a 70.7% aqueous ethylene glycol (EtG) coagulation bath which was at 20.5° C. The solidifying filament was grasped using tweezers, drawn through the bath, and onto the first set of cluster rolls, operating at a surface speed of 60-62 fpm. Coagulation bath wet gel was collected by wrapping the filament around the last roll of this cluster, which was partially immersed in a pure water wash bath at 30.4° C. The wet gel was carefully removed from this cluster roll and then dried at 80°-85° C. in a vacuum oven for 16-18 hours. Examination of the fractured fiber ends using either an optical or SEM microscope revealed that 100% of these fibers were solid with an average filament diameter of 42 microns.
Example 2
This Invention
Production of polyamic acid filaments was carried out in a manner similar to Example 1 with the following experimental conditions:
______________________________________Resin inherent viscosity 1.6 dl/g;Resin viscosity 572 poise at 24.7° C.;Resin % solids 14.5;Resin extrusion rate 0.098 ml/min;Resin temp. 35° C.;Coag. bath % aq. conc. 70% EtOH;Coag. bath temperature 20.1° C.;First cluster roll speed 68-70 fpm; andWash bath temp. 30.3° C.______________________________________
Coagulation bath fibers produced using the above conditions were found to be 100% solid and have a diameter of 33 microns (see FIG. 2C).
Example 3
This Invention
Production of polyamic acid filaments was carried out in a manner similar to Example 1 with the following experimental conditions:
______________________________________Resin inherent viscosity 1.6 dl/g;Resin viscosity 572 poise at 24.7° C.;Resin % solids 14.5;Resin extrusion rate 0.098 ml/min;Resin temp. 35° C.;Coag. bath % aq. conc. 80% EtOH;Coag. bath temperature 19.0° C.;First cluster roll speed 67-69 fpm; andWash bath temeperature 30.4° C.______________________________________
Coagulation bath fibers produced using the above conditions were found to be 100% solid and have a diameter of 35 microns.
Example 4
This Invention
Production of polyamic acid filaments was carried out in a manner similar to Example 3 with the additional experimental conditions:
______________________________________Second cluster roll speed 72-74 fpm; andWinder spool speed 75-76 fpm.______________________________________
Wet gel was now collected by wrapping the filament around a removable pyrex spool on the winder. The spool of filaments was vacuum dried at 80°-85° C. for 16-18 hours. Thermal imidization of these polyamic acid fibers was carried out by heating the spool of fibers in a forced air oven for one hour each at 100°, 200°, and 300° C. These polyimide fibers were found to be 100% solid and have a diameter of 25 microns. Their single filament tensile properties were measured as follows (see Table IV):
______________________________________Tenacity 2.8 × 10.sup.4 psi;Initial modulus 52.7 ×10.sup.4 psi;Yield point 1.8 × 10.sup.4 psi; and% Elongation 65.______________________________________
TABLE IV______________________________________Polyimide Fiber Tensile PropertiesExample Number 10 11 5 4 6Aqueous Coagulation 20% 60% 70% 80% 71%Bath Concentration DMAc EtOH EtOH EtOH EtG______________________________________% Solid Fibers 0 0 100 100 100Filament Diameter 36 26 25 25 25(microns)Tenacity 0.67 1.5 3.0 2.8 2.6(psi × 10.sup.4)Initial Modulus 20.5 46.1 51.0 52.7 51.3(psi ×10.sup.4)Yield Point none none 1.9 1.8 1.8(psi × 10.sup.4)% Elongation 12 15 66 65 68______________________________________
Example 5
This Invention
Production of polyamic acid filaments was carried out in a manner similar to Example 2 with the additional experimental conditions:
______________________________________Second cluster roll speed 71-73 fpm; andWinder spool speed 75-76 fpm.______________________________________
Filaments were collected, dried, and thermally imidized as in Example 4. These polyimide fibers were found to be 100% solid and have a diameter of 25 microns. The single filament tensile properties were measured as follows (see Table IV):
______________________________________Tenacity 3.0 × 10.sup.4 psi;Initial Modulus 51.0 × 10.sup.4 psi;Yield Point 1.9 × 10.sup.4 psi; and% Elongation 66.______________________________________
Example 6
This Invention
Production of polyamic acid filaments was carried out in a manner similar to Example 1 with the additional experimental conditions:
______________________________________Second cluster roll speed 66-68 fpm; andWinder spool speed 72-73 fpm.______________________________________
Filaments were collected, dried, and thermally imidized as in Example 4. These polyimide fibers were found to be 100% solid and have a diameter of 25 microns. Their single filament tensile properties were measured as follows (see Table IV):
______________________________________Tenacity 2.6 × 10.sup.4 psi;Initial Modulus 51.3 × 10.sup.4 psi;Yield Point 1.8 × 10.sup.4 psi; and% Elongation 68.______________________________________
The following examples are not of this invention, but are included for comparative purposes only:
Example 7
Production of polyamic acid filaments was carried out in a manner similar to Example 1 with the following experimental conditions:
______________________________________Resin inherent viscosity 1.6 dl/g;Resin viscosity 428 poise at 24.0° C.;Resin % solids 15.0;Resin extrusion rate 0.098 ml/min;Resin temp. 35° C.;Coag. bath % aq. conc. 72.3% EtG;Coag. bath temperature 20.1° C.;First cluster roll speed 24-26 fpm; andWash bath temperature 30.6° C.______________________________________
Coagulation bath fibers produced using the above conditions were found to be 33% solid and have a diameter of 76 microns.
Example 8
Production of polyamic acid filaments was carried out in a manner similar to Example 1 with the following experimental conditions:
______________________________________Resin inherent viscosity 1.3 dl/g;Resin viscosity 43 poise at 24.0° C.;Resin % solids 14.5;Resin extrusion rate 0.098 ml/min;Resin temp. 28° C.;Coag. bath % aq. conc. 70% EtOH;Coag. bath temperature 20.4° C.;First cluster roll speed 67-68 fpm; andWash bath temperature 30.6° C.______________________________________
Coagulation bath fibers produced using the above conditions were found to be 73% solid and have a diameter of 28 microns (see FIG. 2B).
Example 9
Production of polyamic acid filaments was carried out in a manner similar to Example 1 with the following experimental conditions:
______________________________________Resin inherent viscosity 1.6 dl/g;Resin inherent viscosity 572 poise at 24.7° C.;Resin % solids 14.5;Resin extrusion rate 0.098 ml/min;Resin temp. 35° C.;Coag. bath % aq. conc. 19.8% DMAc;Coag. bath temperature 19.9° C.;First cluster roll speed 60-63 fpm; andWash bath temperature 30.4° C.______________________________________
Coagulation bath fibers produced using the above conditions were found to be 0% solid and have a diameter of 57 microns.
Example 10
Production of polyamic acid filaments was carried out in a manner similar to Example 9 with the additional experimental conditions:
______________________________________Second cluster roll speed 70-73 fpm; andWinder spool speed 75-76 fpm.______________________________________
Filaments were collected, dried, and thermally imidized as in Example 4. These polyimide fibers were found to be 0% solid and have a diameter of 36 microns. Their single filament tensile properties were measured as follows (see Table IV):
______________________________________Tenacity 0.67 × 10.sup.4 psi;Initial Modulus 20.5 × 10.sup.4 psi;Yield Point none; andElongation 12.______________________________________
Example 11
Production of polyamic acid filaments was carried out in a manner similar to Example 1 with the following experimental conditions:
______________________________________Resin inherent viscosity 1.3 dl/g;Resin viscosity 43 poise at 24.0° C.;Resin % solids 14.5;Resin extrusion rate 0.098 ml/min;Resin temp. 23° C.;Coag. bath % aq. conc. 60% EtOH;Coag. bath temperature 20.4° C;First cluster roll speed 67-68 fpm;Wash bath temperature 30.4° C.;2nd cluster roll speed 74-75 fpm; andWinder spool speed 74-75 fpm.______________________________________
Samples of coagulation bath fiber were collected as in Example 1 and found to be 0% solid and have a diameter of 48 microns (see FIG. 2A). Wet gel filaments were collected, dried and thermally imidized as in Example 4. These polyimide fibers were found to be 0% solid and have a diameter of 26 microns. Their single filament tensile properties were measured as follows (see Table IV):
______________________________________Tenacity 1.5 × 10.sup.4 psi;Initial Modulus 46.1 × 10.sup.4 psi;Yield Point none; and% Elongation 15.______________________________________
The foregoing specific examples are merely to illustrate the present invention in exemplary fashion and are not intended, or to be interpreted, as exhaustive.
The specific polyamic acid resin, solvent, coagulation medium compositions and concentrations, and other process conditions in the figures and tables and specific examples herein are also exemplary only and are intended merely to illustrate the process for the production of solid polyamic acid fibers. It is to be understood that the use of these process conditions, including the various coagulation medium composition and concentrations, to achieve solid polyamic acid fibers from other aromatic polyamic acid polymers is considered within the scope of the present invention.
Thus, various modification and variations of the present invention will be apparent to those skilled in the art in light of the above techniques. It is therefore to be understood that, within the scope of the appended claims, the invention may be practiced otherwise than as specifically claimed.
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The invention is a process for the production of solid aromatic polyamic acid and polyimide fibers from a wet gel or coagulation bath wet get using N,N-dimethylacetamide (DMAc) solutions of the polyamic acid derived from aromatic dianhydrides such as 3,3',4,4'-benzophenonetetracarboxylic dianhydride (BTDA) and aromatic diamines such as 4,4'-oxydianiline (4,4'-ODA). By utilizing the interrelationship between coagulation medium and concentration, resin inherent viscosity, resin % solids, filament diameter, and fiber void content, it is possible to make improved polyamic acid fibers. Solid polyimide fibers, obtained by the thermal cyclization of the polyamic acid precursor, have increased tensile properties compared to fibers containing macropores from the same resin system.
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TECHNICAL FIELD
[0001] The present disclosure relates to collision avoidance systems for vehicles.
BACKGROUND
[0002] Vehicles may use dedicated short range communication to exchange information with other vehicles, roadway infrastructure, or other objects traveling on the roadway such as cyclists. The collision avoidance system for a vehicle may use this information to avoid obstacles, determine roadway conditions, or find alternate routes through traffic. Collision avoidance systems may also communicate information exchanged using dedicated short range communication to other vehicle control systems to aid in efficiently operating the vehicle.
SUMMARY
[0003] A system includes a controller. The controller is configured to, in response to receiving location and speed data from other vehicles indicating an expected collision absent a trajectory change, steer a vehicle to avoid the collision on a path. The path is based on map data identifying a marking type for a traveling lane such that the path crosses the lane when the marking type is broken and does not cross the lane when the marking type is solid.
[0004] A vehicle includes a steering wheel and a controller. The controller is configured to, in response to receiving location and speed data from other vehicles indicating an expected collision absent a trajectory change, automatically control the steering wheel to direct the vehicle along a collision avoidance path. The collision avoidance path is based on map data identifying a marking type for a traveling lane such that the path crosses the lane when the marking type is broken and does not cross the lane when the marking type is solid.
[0005] A control method for a vehicle includes, in response to receiving data from other vehicles indicating an expected collision absent a trajectory change, automatically steering the vehicle to avoid the collision on a path. The path is based on data identifying a marking type for a traveling lane such that the path crosses the lane when the marking type is broken and does not cross the lane when the marking type is solid.
BRIEF DESCRIPTION OF THE DRAWINGS
[0006] FIG. 1 is a diagrammatic view of a vehicle having a collision avoidance system;
[0007] FIG. 2 is a diagrammatic view of a vehicle detecting an object using a DSRC transceiver;
[0008] FIG. 3 is a diagrammatic view of a vehicle generating a trajectory to pass the object; and
[0009] FIG. 4 is a flowchart depicting the control logic of the collision avoidance system.
DETAILED DESCRIPTION
[0010] Embodiments of the present disclosure are described herein. It is to be understood, however, that the disclosed embodiments are merely examples and other embodiments may take various and alternative forms. The figures are not necessarily to scale; some features could be exaggerated or minimized to show details of particular components. Therefore, specific structural and functional details disclosed herein are not to be interpreted as limiting, but merely as a representative basis for teaching one skilled in the art to variously employ the present invention. As those of ordinary skill in the art will understand, various features illustrated and described with reference to any one of the figures may be combined with features illustrated in one or more other figures to produce embodiments that are not explicitly illustrated or described. The combinations of features illustrated provide representative embodiments for typical applications. Various combinations and modifications of the features consistent with the teachings of this disclosure, however, could be desired for particular applications or implementations.
[0011] FIG. 1 depicts a vehicle 10 having a collision avoidance system 12 . The collision avoidance system 12 may instruct a controller 14 in communication with a communication transceiver 16 . The communication transceiver 16 may be configured to send and receive information indicative of the location of the vehicle 10 , the speed of the vehicle 10 , and a potential trajectory of the vehicle 10 . In at least one embodiment, the transceiver 16 may be a dedicated short range communication transceiver. The communication transceiver 16 may also use information exchange networks such as, but not limited to, Bluetooth, Wi-Fi, or any other vehicle information exchange communication system. The dedicated short range communication transceiver 16 may allow for communication from vehicle-to-vehicle (V2V), or from vehicle-to-everything (V2X) including roadway infrastructure, cyclists, or any other object that utilizes a communication transceiver 16 .
[0012] As will be described with more detail below, objects such as cyclists may produce unique obstacles for occupants on a roadway. Having a collision avoidance system 12 able to communicate information received from a communication transceiver 16 with a vehicle controller 14 allows for improved communication between vehicles that share the roadway and objects on the roadway. Improved communication between vehicles and objects on the roadway further aids in preventing impact events. For example, as will be described with reference to the other figures, a cyclist (not shown) may occupy a vehicle lane (not shown). The collision avoidance system 12 may use a navigation system 18 as well as a vision system 17 to exchange information, via the communication transceiver 16 , with the cyclist. The vision system 17 may use onboard cameras, ultrasonic sensors, or any other sensor that may detect vehicle surroundings. The vision system 17 may use the cameras and the ultrasonic sensors either individually or simultaneously to accurately depict the surroundings of the vehicle. The navigation system 18 may use map data and global positioning system data to transfer information such as vehicle speed, vehicle trajectory, and the roadway environment.
[0013] The collision avoidance system 12 uses the information transfer from the communication transceiver 16 and the vision system 17 and navigation system 18 to improve performance of the vehicle 10 . The collision avoidance system 12 communicates the information to the controller 14 in order to alert an occupant of an oncoming object, such as a cyclist, adjust the vehicle trajectory to compensate for the cyclist, or alter vehicle components, such as a brake pedal position, to adjust a vehicle position relative to the cyclist. The collision avoidance system 12 may instruct the controller 14 to adjust other vehicle systems either individually, or simultaneously as the circumstances require. The controller 14 may be configured to adjust any vehicle system, such as a steering system 20 that may aid in improving performance of the vehicle 10 based on the information received from the communication transceiver 16 of the cyclist's position, speed, or trajectory.
[0014] Referring to FIGS. 2 and 3 , a schematic depiction of the vehicle 10 using the collision avoidance system 12 is shown. FIG. 2 depicts identification of a cyclist 22 within a first lane 24 of a road 26 and an adjacent vehicle 28 within a second lane 30 of the road 26 . FIG. 3 depicts the vehicle 10 executing the maneuver from the first lane 24 into the second lane 30 based on the information exchange between the adjacent vehicle 28 and the cyclist 22 . As will be discussed in more detail below, the collision avoidance system 12 communicates with the controller 14 and the communication transceiver 16 to obtain and analyze information to safely execute a vehicle maneuver avoiding the cyclist 22 .
[0015] FIG. 2 depicts identification of the cyclist 22 and arbitration between the collision avoidance system 12 , the controller 14 , and the transceiver 16 . As the vehicle 10 approaches the cyclist 22 , the transceiver 16 receives data broadcast from the cyclist 22 indicating the cyclist's 22 presence. In at least one embodiment, the transceiver 16 uses dedicated short range communication to receive the data from the cyclist 22 . This allows the transceiver 16 to begin receiving input data from the cyclist 22 within a range of approximately 300 m. Once a cyclist 22 has been identified by the transceiver 16 , the collision avoidance system 12 may use the vision system 17 , as described above, to confirm the presence of the cyclist 22 . The vision system 17 confirms the presence of the cyclist 22 as to vehicle 10 approaches and comes within range of the vision system 17 .
[0016] The transceiver 16 may communicate data received from the cyclist 22 such as the location and speed of the cyclist 22 to the collision avoidance system 12 . The vision system 17 also transmits the location of the cyclist 22 to the collision avoidance system 12 . Use of both the transceiver 16 and the vision system 17 gives the collision avoidance system 12 an accurate representation of at least the location of the cyclist 22 . The navigation system 18 may also provide map data to the collision avoidance system 12 . For example, the navigation system 18 may be configured to transmit map data from an external server 32 to instruct the collision avoidance system 12 . Map data from the navigation system 18 may include, but is not limited to, an indication of the first lane 24 and the second lane 30 . The navigation system 18 instructs the collision avoidance system 12 if the first lane 24 may also be considered a bike lane for the cyclist 22 . Likewise, the navigation system 18 may instruct the collision avoidance system 12 if the first lane 24 may be considered a traveling lane for the vehicle 10 . While the road 26 is depicted as having a first lane 24 and a second lane 30 , the navigation system 18 may also be configured to determine any number of lanes on the road 26 , such as a third lane 31 and a fourth lane 33 .
[0017] The collision avoidance system 12 compares the location data of the cyclist 22 from the transceiver 16 and the vision system 17 and the map data from the navigation system 18 to determine the location of the cyclist 22 within the first lane 24 . While depicted as a cyclist 22 , the transceiver 16 and vision system 17 with the navigation system 18 may be able to instruct the collision avoidance system 12 of any other object's existence that may impede the vehicle 10 . Once the collision avoidance system 12 identifies that the cyclist 22 is traveling in the first lane 24 and impeding the vehicle 10 , the collision avoidance system 12 analyzes the road 26 . For example, using the navigation system 18 and the vision system 17 , the collision avoidance system 12 determines a roadway characteristic 34 , such as lane markings.
[0018] As stated above, the navigation system may instruct the collision avoidance system 12 as to the number of lanes on the road 26 as well as the type of road 26 the vehicle 10 is traveling. The vision system 17 may be used to identify and confirm the type of lane markings 34 on the road 26 . For example, the navigation system 18 may instruct the collision avoidance system 12 that the vehicle 10 is traveling on a highway and the vision system 17 may identify the dashed yellow lines consistent with the lane markings of a highway. The vision system 17 may also be used to identify any other type of lane marking commonly used on the road 26 , such as but not limited to, double yellow lines, single white lines, or a single yellow line with an adjacent dashed yellow line.
[0019] The collision avoidance system 12 uses the roadway characteristics 34 from the navigation system 18 and the vision system 17 to analyze a roadway environment 36 . The collision avoidance system 12 may use input from the transceiver 16 to determine and analyze the current roadway environment 36 . The transceiver 16 , as stated above, may also be used to transmit data from an adjacent vehicle 28 , or from any other infrastructure that uses dedicated short range communication. For example, the roadway environment 36 may include data from traffic lights, stop signs, or any other infrastructure used to affect maneuvers of the vehicle 10 . The collision avoidance system 12 uses the roadway characteristics 34 and the roadway environments 36 determined from the transceiver 16 , the vision system 17 , and the navigation system 18 to analyze the environment around and external to the vehicle 10 .
[0020] FIG. 3 continues to depict arbitration between the collision avoidance system 12 , the controller 14 , and the transceiver 16 , as well as depicting maneuver execution of the vehicle 10 . After analyzing the environment external to the vehicle 10 , the collision avoidance system 12 determines a potential trajectory 38 for the vehicle 10 . The potential trajectory 38 may be based on the roadway environment 36 and the roadway characteristics 34 to determine a safe maneuver for the vehicle 10 avoiding the cyclist 22 . The potential trajectory 38 may be analyzed by the collision avoidance system 12 and include instances such as crossing into the second lane 30 or biasing the vehicle 10 within the first lane 24 . These determinations are again evaluated based on the roadway characteristics 34 and the roadway environments 36 , as discussed above. For example, the collision avoidance system 12 verifies that the potential trajectory 38 will not intersect with the adjacent vehicle 28 or the cyclist 22 . Likewise, the collision avoidance system 12 verifies that the potential trajectory 38 is a legal and safe maneuver for the vehicle 10 . For example, the collision avoidance system 12 verifies that the potential trajectory 38 does not cross double yellow center lane markings or does not pass while crossing an intersection at a stoplight.
[0021] Collision avoidance system 12 may also generate the potential trajectory 38 based on a conditional state 40 of the road 26 . For example, the collision avoidance system 12 may receive data from the transceiver 16 indicative of a roadway intrusion 42 , such as a pothole or present construction. Likewise, the collision avoidance system 12 may receive data from the navigation system 18 indicative of a roadway condition 44 , such as a recent rain or ice formation. The controller 14 may also receive input from external vehicle sensors 46 to allow the collision avoidance system to verify the roadway condition 44 . For example, a rain or temperature sensor and an ultrasonic sensor may allow the controller 14 to instruct the collision avoidance system 12 as to potential road intrusions 42 or roadway conditions 44 . The collision avoidance system 12 uses the data indicative of the roadway environment 36 , the roadway characteristics 34 , the roadway intrusions 42 , and the roadway conditions 44 to indicate a probability that the potential trajectory 38 will result in a safe and executable maneuver for the vehicle 10 . If the probability of the potential trajectory 38 is above a preset threshold, the collision avoidance system 12 may begin instructing the controller 14 to execute a maneuver for the vehicle 10 . Likewise, if the probability of the potential trajectory 38 is below the preset threshold, the collision avoidance system 12 aborts the maneuver. This will be discussed in more detail with reference to FIG. 4 .
[0022] If maneuvering the vehicle 10 is probable, the collision avoidance system 12 indicates to an occupant of the pending maneuver. The collision avoidance system 12 may instruct the controller 14 to actuate an indicator 48 within a cabin 50 of the vehicle 10 . The indicator 48 may be any human machine interface component within the vehicle, such as but not limited to, an auditory warning, a visual warning, or haptic feedback provided to an occupant of the vehicle 10 . For example, the indicator 48 may include illuminating lights, producing a tone, or vibrating a vehicle component, such as a steering wheel (not shown), a pedal (not shown), or a seat (not shown). The indicator 48 may be active during all instances of execution and may use a single indication, or multiple indications throughout the maneuver execution. For example, the controller 14 may actuate the indicator 48 to illuminate a light indicating the presence of the cyclist 22 .
[0023] The controller 14 may then actuate the indicator 48 to produce a tone alerting the occupant that the potential trajectory 38 may either be executed or not executed to avoid the cyclist 22 . The controller 14 may also actuate the indicator 48 to provide haptic feedback on the steering wheel to alert the occupant that the vehicle 10 is crossing into the second lane 30 . The indicator 48 may also be indicative of execution of the maneuver. As by examples, the light may illuminate in the shape of a bicycle, the tone may give auditory instructions to the occupant, and the haptic feedback may be present on a side of the steering wheel adjacent to where the potential trajectory 38 may be maneuvering. By actuating the indicator 48 through all stages of execution, the collision avoidance system 12 also allows an occupant to abort the potential trajectory 38 .
[0024] If the probability of the potential trajectory 38 is above the threshold and an occupant has not aborted the potential trajectory 38 based on the indicator 48 , the collision avoidance system 12 maneuvers the vehicle 10 . The collision avoidance system 12 maneuvers the vehicle 10 using the controller 14 . The controller 14 may actuate vehicle systems, such as but not limited to, the steering system and the brake and accelerator pedal position systems. The controller 14 may instruct the steering system and the brake accelerator pedal position systems based upon input received from sensors within the systems. For example, the controller 14 may adjust a steering angle of the steering wheel based on input from a steering angle sensor as compared to the potential trajectory 38 provided by the collision avoidance system 12 . Likewise, the controller 14 may adjust a brake pedal position or an accelerator pedal position based on input from a wheel speed sensor or accelerometer as compared to the potential trajectory 38 provided by the collision avoidance system 12 . The controller 14 , through use of the steering system and the brake and pedal position systems, may be a lateral positioning controller 14 . The lateral positioning controller 14 uses inputs from various vehicle systems, as described above, to safely and accurately maneuver the vehicle 10 around the cyclist 22 according to the potential trajectory 38 as provided by the collision avoidance system 12 .
[0025] The collision avoidance system 12 may constantly monitor the controller 14 , the transceiver 16 , the vision system 17 , and the navigation system 18 . The collision avoidance system 12 constantly receives data from the transceiver 16 , the vision system 17 , and the navigation system 18 to allow for compensation during execution of the potential trajectory 38 . For example, the adjacent vehicle 28 and/or the cyclist 22 may suddenly and unexpectedly change speed or alter positions. The change in speed or altering of positions of the adjacent vehicle 28 and/or the cyclist 22 may make the potential trajectory 38 unsatisfactory. By constantly monitoring, the collision avoidance system 12 may use the transceiver 16 , the vision system 17 , and the navigation system 18 to change or abort the potential trajectory 38 based upon updated input data from the transceiver 16 , the vision system 17 , and the navigation system 18 . Constant monitoring also allows the collision avoidance system 12 to be adaptable based on the roadway environment 36 , the roadway characteristics 34 , the roadway intrusions 42 , and the roadway conditions 44 . The collision avoidance system 12 uses these inputs to abort the potential trajectory 38 if the controller 14 has not yet begun maneuvering, or to generate a second trajectory 52 , if necessary.
[0026] The second trajectory 52 may return the vehicle 10 to the first lane 24 , or may continue to pass the cyclist 22 if the collision avoidance system 12 determines, based on the inputs described above, that passing cyclist 22 is feasible. For example, the second trajectory 52 may include returning the vehicle 10 to a center 54 of the first lane 24 and instructing the controller 14 to adjust the speed of the vehicle 10 by changing a brake pedal position. The second trajectory 52 may also include a biasing position of the vehicle 10 away from a center 54 of the first lane 24 and crossing into the second lane 30 after the adjacent vehicle 28 has passed. The collision avoidance system 12 works in conjunction with the controller 14 , the transceiver 16 , the vision system 17 , and the navigation system 18 to account for and adapt to unexpected events that may occur during normal vehicle operation.
[0027] Further, while passing the cyclist 22 , the collision of avoidance system 12 may instruct the controller 14 to adjust vehicle features to ensure safe passage of the cyclist 22 . For example, the collision avoidance system 12 may instruct the controller 14 to lower a windshield wiper speed to avoid wiping excess water from the windshield onto the cyclist 22 . By instructing the controller 14 to adjust various vehicle features, the collision avoidance system ensures that the cyclist 22 is not surprised by the passing vehicle 10 and is able to maintain control as the vehicle 10 passes the cyclist 22 . The collision avoidance system 12 ensures that the vehicle 10 safely maneuvers around the cyclist 22 .
[0028] FIG. 4 depicts a flow chart of the control logic used by the collision avoidance system 12 . The collision avoidance system 12 uses control logic to operate as described above. However, the collision avoidance system 12 may also segment the control logic. For example, the collision avoidance system 12 may also be configured to only generate the warnings as described above, or utilize lane positioning as described above. Likewise, the control logic for the collision avoidance system 12 is described as sequential, however may be operated simultaneously. Operation of the collision avoidance system 12 may be accomplished using the steps described below in any manner or fashion that allows the collision avoidance system 12 to operate as discussed.
[0029] As described above, the collision avoidance system 12 constantly monitors inputs from the transceiver, the controller, the navigation system, and the vision system at 60 . The collision avoidance system 12 processes these inputs at 62 consistent with the above description. Data processing at 62 allows the collision avoidance system 12 to decide if the vehicle is approaching the cyclist at 64 . If at 64 the collision avoidance system 12 determines that the vehicle is not approaching the cyclist, the collision avoidance system returns to continually process the input data at 62 . Continual processing of the input data at 62 allows the collision avoidance system 12 to work continuously to monitor the environment of the vehicle. If at 64 the collision avoidance system 12 determines that the vehicle is approaching the cyclist, the collision avoidance system 12 alerts an occupant of the pending approach at 66 . As stated above, the alert at 66 may be an audible tone at a given frequency or auditory message spoken in a language of the occupant. In at least one other embodiment, the alert may be a visual indicator, such as illuminating a light, or a physical indicator such as haptic feedback on a seat, steering wheel, or pedal. Alerting the occupant at 66 allows the collision avoidance system 12 to inform the occupant of a possible pending maneuver.
[0030] The collision avoidance system 12 uses the inputs described above to determine if crossing into an adjacent lane is necessary at 68 . If the collision avoidance system 12 determines that crossing into an adjacent lane at 68 is not necessary, the collision avoidance system 12 determines if the current traveling lane of the vehicle is clear of other obstacles at 70 . If at 70 the current traveling lane is not clear of other obstacles, then the collision avoidance system 12 alerts the occupant that executing the maneuver may not be safe at 72 . As stated above, the alert at 72 may be an audible tone at a given frequency or auditory message spoken in a language of the occupant. In at least one other embodiment, the alert may be a visual indicator, such as illuminating a light, or a physical indicator such as haptic feedback on a seat, steering wheel, or pedal. After the collision avoidance system 12 aborts a potential maneuver at 72 , the control logic returns to again process the input data at 62 . If however the collision avoidance system 12 determines at 70 that the traveling lane is clear of other obstacles, the collision avoidance system 12 may dynamically adjust the position of the vehicle within the current traveling lane at 74 . Dynamically adjusting the position of the vehicle at 74 may include biasing the vehicle to either side of the center of the lane and/or adjusting the speed of the vehicle to account for the cyclist. At 76 , the collision avoidance system 12 instructs the controller to adjust the vehicle systems necessary to account for the cyclist and the control logic continues to process the input data at 62 .
[0031] Referring back to 68 , if the collision avoidance system 12 determines that crossing into the adjacent lane is necessary, the collision avoidance system 12 uses the inputs and environment as described above to determine if crossing into the adjacent lane is a legal maneuver at 78 . If at 78 the collision avoidance system 12 determines that crossing into the adjacent lane is not legal, the collision avoidance system 12 alerts the occupant that a maneuver will not be attempted for legal reasons at 80 and the control logic continues to process the input data at 62 . Alerting the occupant at 80 that the maneuver will not be attempted due to legal reasons, allows the occupant an opportunity to verify the accuracy of the determination made by the collision avoidance system 12 at 78 . As stated above, the alert at 80 may be an audible tone at a given frequency or auditory message spoken in a language of the occupant. In at least one other embodiment, the alert may be a visual indicator, such as illuminating a light, or a physical indicator such as haptic feedback on a seat, steering wheel, or pedal.
[0032] If at 78 the collision avoidance system 12 determines that crossing into the adjacent lane is a legal maneuver, the collision avoidance system then determines if crossing into the adjacent lane constitutes a safe maneuver at 82 . Again, the collision avoidance system 12 makes a determination that execution of a possible maneuver is safe at 82 based on inputs received from the vehicle systems indicative of the surrounding vehicle environment, the roadway characteristics, possible roadway of obtrusion, and the roadway condition. If the collision avoidance system 12 determines that crossing into the adjacent lane is not safe at 82 , the collision avoidance system 12 instructs the controller to alert the occupant that a maneuver will not be attempted due to safety considerations at 84 and the control logic continues to process the input data at 62 . Alerting the occupant that a maneuver may not be executed due to safety considerations at 84 allows the occupant to verify the accuracy of the determination made by the collision avoidance system 12 at 82 . This allows the occupant to override the determination at 82 and eliminates potential error of the collision avoidance system 12 . As stated above, the alert at 84 may be an audible tone at a given frequency or auditory message spoken in a language of the occupant. In at least one other embodiment, the alert may be a visual indicator, such as illuminating a light, or a physical indicator such as haptic feedback on a seat, steering wheel, or pedal.
[0033] If at 82 the collision avoidance system 12 determines that a maneuver may be attempted, the collision avoidance system alerts the occupant that the vehicle will execute the maneuver based on the calculated trajectory at 86 . As stated above, the alert at 86 may be an audible tone at a given frequency or auditory message spoken in a language of the occupant. In at least one other embodiment, the alert may be a visual indicator, such as illuminating a light, or a physical indicator such as haptic feedback on a seat, steering wheel, or pedal. Alerting the occupant that a vehicle maneuver will be attempted at 86 allows the occupant an opportunity to abort the maneuver. The collision avoidance system 12 will monitor preset vehicle system inputs indicative of an occupant-initiated abortion of the maneuver and determine at 88 if the occupant has signaled to abort the maneuver. The preset vehicle system inputs indicative of an occupant-initiated abortion may include, but are not limited to, depressing the brake pedal, a voice recognition feature for the occupant, or using a human machine interface to select a button on a display.
[0034] If at 88 the collision avoidance system 12 receives input of an occupant-initiated abortion, the maneuver will not be executed and the control logic continues to process the input data at 62 . However, if at 88 the collision avoidance system 12 does not receive input of an occupant-initiated abortion, then at 90 the collision avoidance system 12 will instruct the controller to use lateral position control and partially move into the adjacent lane, or move completely into the adjacent lane avoiding the cyclist. The collision avoidance system 12 will automatically steer the vehicle to avoid the collision on a path that is based on map data from the navigation system identifying a marking type for the traveling lane.
[0035] While exemplary embodiments are described above, it is not intended that these embodiments describe all possible forms encompassed by the claims. The words used in the specification are words of description rather than limitation, and it is understood that various changes may be made without departing from the spirit and scope of the disclosure. As previously described, the features of various embodiments may be combined to form further embodiments of the invention that may not be explicitly described or illustrated. While various embodiments could have been described as providing advantages or being preferred over other embodiments or prior art implementations with respect to one or more desired characteristics, those of ordinary skill in the art recognize that one or more features or characteristics may be compromised to achieve desired overall system attributes, which depend on the specific application and implementation. These attributes may include, but are not limited to cost, strength, durability, life cycle cost, marketability, appearance, packaging, size, serviceability, weight, manufacturability, ease of assembly, etc. As such, embodiments described as less desirable than other embodiments or prior art implementations with respect to one or more characteristics are not outside the scope of the disclosure and may be desirable for particular applications.
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A vehicle includes a steering wheel and a controller. The controller is configured to, in response to receiving location and speed data from other vehicles indicating an expected collision absent a trajectory change, automatically control the steering wheel to direct the vehicle along a collision avoidance path. The collision avoidance path is based on map data identifying a marking type for a traveling lane such that the path crosses the lane when the marking type is broken and does not cross the lane when the marking type is solid.
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CROSS-REFERENCE TO RELATED APPLICATIONS
This application claims the priority of Korean Patent Application No. 10-2010-0065447 filed on Jul. 7, 2010, in the Korean Intellectual Property Office, 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 manufacturing a lithium ion capacitor and a lithium ion capacitor manufactured using the same and, more particularly, to a method for manufacturing a lithium ion capacitor capable of obtaining a high output density and excellent capacity and reducing a manufacturing process time, and a lithium ion capacitor manufactured using the same.
2. Description of the Related Art
In various electronic products such as an information communication device, and the like, a stable energy supply is an important factor. In general, such a function is performed by a capacitor. Namely, the capacitor serves to collect electricity in circuits of the information communication device and various electronic products and output it, thus stabilizing the flow of electricity within the circuits. A general capacitor has a very short charging and discharging time and a high output density, but because it has a low energy density, it has limitations in being used as an energy storage device.
Thus, in order to overcome such limitations of a general capacitor, recently, a novel capacitor such as an electrical double layer capacitor (EDLC) has been developed, which has come into prominence as a next-generation energy device along with a rechargeable battery or a secondary battery.
Also, recently, diverse electrochemical elements, whose operating principles are based on similar principles to those of an ELDC, have been developed, and an energy storage device called a hybrid capacitor, formed by combining power storage principles of a lithium ion secondary battery and the ELDC, has come into prominence. As a hybrid capacitor, a lithium ion capacitor, in which a hole is formed to penetrate both surfaces (i.e., front and rear surfaces) of a cathode current collector and those of an anode current collector, a material which can reversibly carry lithium ions is used as an anode electrode material, a lithium metal is disposed to oppose an anode (negative electrode) or a cathode (positive electrode), and lithium ions are carried to the anode according to electrochemical contact between the lithium metal and the anode or the cathode, has been proposed.
In order to dope the anode of the lithium ion capacitor with lithium ions, various methods have been attempted. For example, cathodes and anodes are formed on the collector including the hole penetrating the both surfaces thereof, and the lithium metal is disposed on a laminated body formed as the plurality of cathodes and the plurality of anodes are laminated. The anodes are doped with lithium ions emitted from the lithium metal. In this case, because lithium ions can be moved without being interrupted within the electrode current collector, the lithium ions can be electrochemically carried to the plurality of laminated anodes even in a power storage device including a large number of laminated cells.
SUMMARY OF THE INVENTION
An aspect of the present invention provides a method for manufacturing a lithium ion capacitor capable of reducing a manufacturing process time and obtaining a high output density and excellent capacity, and a lithium ion capacitor manufacturing using the same.
According to an aspect of the present invention, there is provided a method for manufacturing a lithium ion capacitor, including: disposing a lithium metal on a capacitor cell including a cathode, a separation film, and an anode; impregnating the capacitor cell with electrolyte including a lithium salt; changing the cathode and the anode to allow lithium ions within the electrolyte to be occluded into the anode; performing a primary reaction in which the cathode and the lithium metal are short-circuited to emit anions from the cathode and lithium ions from the lithium metal and a secondary reaction that the lithium ions emitted from the lithium metal are occluded into the anode; and recharging the cathode and the anode to allow the lithium ions, which have been occluded into the cathode and the lithium ions within the electrolyte, to be occluded into the anode.
The method may further include: discharging the cathode and the lithium metal to emit the anions, which have been occluded into the cathode, after the cathode and the anode are recharged.
The capacitor cell may have a form of a laminated body formed by laminating a plurality of cathodes, separation films and anodes.
The capacitor cell may have a form in which the cathode, the separation film, and the anode are wound.
The cathode and the anode may be formed by forming an electrode material, into which lithium ions can be irreversibly occluded, on a conductive sheet, and the conductive sheet may have a form of a foil or a mesh.
The short-circuiting of the cathode and the lithium metal may be performed stepwise with a voltage difference.
According to another aspect of the present invention, there is provided a lithium ion capacitor manufactured by performing the method including: disposing a lithium metal on a capacitor cell including a cathode, a separation film, and an anode; impregnating the capacitor cell with electrolyte including a lithium salt; changing the cathode and the anode to allow lithium ions within the electrolyte to be occluded into the anode; performing a primary reaction in which the cathode and the lithium metal are short-circuited to emit anions from the cathode and lithium ions from the lithium metal and a secondary reaction that the lithium ions emitted from the lithium metal are occluded into the anode; and recharging the cathode and the anode to allow the lithium ions, which have been occluded into the cathode and the lithium ions within the electrolyte, to be occluded into the anode.
BRIEF DESCRIPTION OF THE DRAWINGS
The above and other aspects, features and other advantages of the present invention will be more clearly understood from the following detailed description taken in conjunction with the accompanying drawings, in which:
FIG. 1 is a schematic sectional view showing a capacitor cell according to an exemplary embodiment of the present invention;
FIG. 2 is a schematic perspective view showing a cathode according to an exemplary embodiment of the present invention;
FIGS. 3 a to 3 c are schematic view showing the process of a method of occluding lithium ions into an anode according to an exemplary embodiment of the present invention; and
FIG. 4 schematically shows the process of occluding lithium ions into an anode according to an exemplary embodiment of the present invention.
DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENT
Exemplary embodiments of the present invention will now be described in detail with reference to the accompanying drawings. The invention may, however, be embodied in many different forms and should not be construed as being limited to the embodiments set forth herein. Rather, these embodiments are provided so that this disclosure will be thorough and complete, and will fully convey the scope of the invention to those skilled in the art. In the drawings, the shapes and dimensions may be exaggerated for clarity, and the same reference numerals will be used throughout to designate the same or like components.
FIG. 1 is a schematic sectional view showing a capacitor cell according to an exemplary embodiment of the present invention. FIG. 2 is a schematic perspective view showing a cathode according to an exemplary embodiment of the present invention. FIGS. 3 a to 3 c are schematic view showing the process of a method of occluding lithium ions into an anode according to an exemplary embodiment of the present invention. FIG. 4 schematically shows the process of occluding lithium ions into an anode according to an exemplary embodiment of the present invention.
First, as shown in FIG. 1 , a cathode (or a positive electrode) 10 , a separation film 30 , an anode (or a negative electrode) 20 are sequentially laminated to form a capacitor cell 50 . In the present exemplary embodiment, the capacitor cell 50 may be a laminated body. A plurality of cathodes 10 and a plurality of anodes 20 may be laminated to obtain a desired electric capacity.
Although not shown, the capacitor cell may have a form in which sequentially disposed cathodes, separation films, and anodes are wound.
With reference to FIG. 2 , the cathode 10 may be formed by forming an electrode material 12 on a conductive sheet 11 . Also, although not shown, the cathode 10 may be a double-sided electrode with the electrode material 12 formed on both sides of the conductive sheet 11 .
As the electrode material 12 , a material into which lithium can be irreversibly occluded may be used. For example, a carbon material such as graphite, hard carbon, or coke, a polyacene-based material, or the like, may be used as the electrode material 12 , but the present invention is not limited thereto.
The cathode 10 may be made of a mixture of the electrode material 12 and a conductive material. As the conductive material, for example, acetylene black, graphite, metal powder, and the like, may be used; however, the present invention is not limited thereto.
The thickness of the electrode material 12 may range, for example, from 15 μm to 100 μm, but is not particularly limited.
The conductive sheet 11 delivers an electrical signal to the electrode material 12 and serves as a current collector for collecting accumulated electrical charges. The conductive sheet 11 may be formed as a metallic foil, a conductive polymer, or the like. The metallic foil may be made of stainless steel, copper, nickel, or the like.
The conductive sheet 11 may have a foil form or a mesh form having through holes. According to the present exemplary embodiment, lithium ions from the lithium metal are emitted to electrolyte and then absorbed into the cathode 10 . After being occluded into the cathode 10 , the lithium ions are delivered to the anode 20 . Through this process, the conductive sheet in the foil form or the mesh form may be used according to the present exemplary embodiment.
The conductive sheet 11 may include a lead part 11 a in order to apply electricity to the capacitor cell 50 .
Although not shown, an electrode material may be manufactured in the form of a solid sheet so as to be used as a cathode, without using the conductive sheet.
Like the cathode 10 , the anode 20 may be formed by forming an electrode material on the conductive sheet in the present exemplary embodiment.
In the present exemplary embodiment, the separation film 30 may be disposed between the cathode 10 and the anode 20 in order to electrically insulate the cathode 10 and the anode 20 . The separation film 30 may be a made of a porous material allowing ions to be transmitted therethrough. The porous material may be polypropylene, polyethylene, or glass fiber, but may not be limited thereto.
A lithium metal 40 is disposed on the capacitor cell 50 . In the present exemplary embodiment, lithium metals 40 are disposed on the outermost portions of the capacitor cell 50 .
In the present exemplary embodiment, the lithium metal 40 serves to provide lithium ions to be occluded into the anode, and can be disposed at an appropriate position. For example, the lithium metal 40 may be disposed on the side of the capacitor cell 50 .
FIG. 3 a is a schematic perspective view showing the capacitor cell with lithium metals disposed thereon. With reference to FIG. 3 a , lead parts 11 a , 21 a , and 40 a are drawn out in order to apply electricity to the cathodes, the anodes, and the lithium metals.
Next, as shown in FIG. 3 b , in order to impregnate the capacitor cell with electrolyte, the capacitor cell is sealed with a pouch (p), into which electrolyte may be injected. The electrolyte may not be particularly limited so long as it contains lithium salt, and an electrolyte known in the art may be used.
Then, voltage is applied to the cathode lead part 11 a and the anode lead part 21 a to charge the cathode and the anode.
Thereafter, as shown in FIG. 3 c , the cathode and the lithium metal are short-circuited by using the cathode lead part 11 a and the lithium metal lead part 40 a.
Subsequently, the cathode and the anode may be recharged by using the cathode lead part 11 a and the anode lead part 21 a (not shown). Thereafter, the cathode and the lithium metal may be discharged by using the cathode lead part 11 a and the lithium metal lead part 40 a (not shown).
FIG. 4 schematically shows the process of occluding lithium ions into an anode according to an exemplary embodiment of the present invention.
When the cathode and the anode are charged, the lithium ions in the electrolyte are occluded into the anode (step 1 ).
Next, the cathode and the lithium metal are short-circuited to perform a primary reaction in which anions are emitted from the cathode and lithium ions are emitted from the lithium metal (step 2 - 1 ). The primary reaction may be performed with the voltage ranging from 2V to 4V.
When the voltage is continuously lowered after the primary reaction, a secondary reaction that lithium ions are occluded into the cathode is performed (step 2 - 2 ). The lithium ions occluded into the cathode may include lithium ions present in the electrolyte, but may be understood as lithium ions which have been emitted from the lithium metal. The secondary reaction may be performed at a lower voltage than that of the primary reaction. Namely, the secondary reaction may be performed while the voltage is being lowered to 0V.
The short-circuiting of the cathode and the lithium metal may be slowly performed stepwise with a potential difference in order to perform the primary reaction and the secondary reaction.
Thereafter, when the cathode and the anode are recharged, lithium ions are occluded into the anode. In detail, lithium ions which have been occluded into the cathode are emitted into the electrolyte so as to be occluded into the anode (step 3 - 1 ) and the lithium ions present in the electrolyte are occluded into the anode (step 3 - 2 ).
In this case, lithium ions are occluded into the anode by the amount balancing with the cathode. Namely, the lithium ions, which have been occluded into the cathode, are emitted to be occluded into the anode, and lithium ions by the amount of anions occluded into the cathode are additionally occluded into the anode.
Namely, in the present exemplary embodiment, lithium ions are occluded into the cathode according to the short-circuiting of the cathode and the lithium metal, and accordingly, the amount of lithium ions occluded into the anode later increases.
Thereafter, the cathode and the lithium metal may be discharged to emit anions present in the cathode.
After lithium ions are occluded into the anode in the foregoing manner, one side of the pouch may be cut to emit a generated gas, and the installed lithium metal may be removed to thus complete the lithium ion capacitor.
According to the present exemplary embodiment, because the cathode is utilized as a storage medium of lithium ions, the amount of lithium ions occluded into the anode can be increased. Accordingly, time can be shortened compared with the related art lithium ion occlusion process.
In addition, another exemplary embodiment of the present invention may provide a lithium ion capacitor. The lithium ion capacitor according to the present exemplary embodiment can have an increased amount of lithium ions occluded into the cathode, so it can have high capacity and high output density.
As set forth above, according to exemplary embodiments of the invention, a cathode can be utilized as a storage medium of lithium ions, so the amount of lithium ions finally occluded into an anode can be increased. Thus, time can be shortened compared with the related art process of occluding lithium ions.
In addition, because the amount of lithium ions occluded into the anode of the lithium ion capacitor is increased, the lithium ion capacitor can have an increased capacity and a high output density.
While the present invention has been shown and described in connection with the exemplary embodiments, it will be apparent to those skilled in the art that modifications and variations can be made without departing from the spirit and scope of the invention as defined by the appended claims.
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A method for manufacturing a lithium ion capacitor, and a lithium ion capacitor manufactured using the method are provided. The method for manufacturing a lithium ion capacitor includes: disposing a lithium metal on a capacitor cell including a cathode, a separation film, and an anode; impregnating the capacitor cell with electrolyte including a lithium salt; changing the cathode and the anode to allow lithium ions within the electrolyte to be occluded into the anode; performing a primary reaction in which the cathode and the lithium metal are short-circuited to emit anions from the cathode and lithium ions from the lithium metal and a secondary reaction that the lithium ions emitted from the lithium metal are occluded into the cathode; and recharging the cathode and the anode to allow the lithium ions, which have been occluded into the cathode and the lithium ions within the electrolyte, to be occluded into the anode.
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This application is a division of application Ser. No. 08/171,150, filed Dec. 21, 1993 now U.S. Pat. No. 5,574,047.
BACKGROUND OF THE INVENTION
It has long been known that over the course of an individual's life, one's tissues and organs are subjected to numerous assaults which can compromise their normal function. One of the most important attributes of tissues and organs is their ability to repair damage inflicted on it in order to maintain normal homeostasis. In many circumstances, this repair function is complete and normal function is restored without resulting sequelae. This is often the case when the insult is acute and somewhat mild in nature. However, in other cases, the attempt of a specific tissue to repair the damage inflicted results in either decreased function of the affected tissue and/or an induction of a detrimental effect on another tissue. In acute injury, the imperfect repair leading to a small decrease in tissue function may go unnoticed or be of little consequence, due to the reserve capacity of that tissue to maintain its proper function. In the case of repeated, acute injury, often seen when the injury is caused by external, environmental factors, the small incremental loss of tissue function may be additive. Thus, repeated, acute injury may result in a chronic condition and lead to ultimate failure of the affected tissue or organ. Such repeated, acute injury of various organs are seen with alcohol damage to the liver, infections of the pulmonary tract, exposure to toxins from the environment on the liver, kidney, and pulmonary tract, and the toxic effect of certain drugs, e.g., oncolytic agents, antibiotics, anti-arthritis agents, etc.
In addition to acute and repeated-acute injury, there are many conditions which can be called truly chronic. These conditions may be defined where the injury inflicted on a particular tissue or organ is continuous over a long period of time. Often, the source of chronic injury originates from a condition within the body affecting particular organs and tissues, which may or may not have been directly involved in the originating pathology. This induction of one tissue's pathology into an other tissue's function gives rise to the formation of entire syndromes of various pathologies which are often seen in chronic diseases. Imperfect or inappropriate repair attempts by affected tissues or organs in chronic pathologies may be similar to that seen with acute repair attempts or may be different; however, the results tend to be similar in that there is incremental loss of function which leads to eventual complete or partial failure.
Two examples of chronic conditions which could lead to multi-organ pathologies in which imperfect or inappropriate tissue repair is contributory to eventual organ failure are diabetes mellitus and auto immune diseases, e.g., systemic lupus erythematosus (SLE), rheumatoid arthritis, etc. Chronic pathologies may often be more insidious and less controllable in nature than some of the pathologies associated with acute injury, in that they often are undetected prior to organ failure and often result from originating insults which are poorly understood or which may result at least in part due to a genetic predisposition.
As mentioned before, many pathologies resulting from either acute or chronic insult and subsequent imperfect, ineffective, or inappropriate repair by tissues or organs, are associated with syndromes, i.e., pathologies of many different organs with multiple sequelae. Thus a single causative event can trigger a cascade of events in various body systems. For example, patients suffering from SLE may exhibit pathologies in the kidney, vasculature, lungs, and liver, largely due to one underlying cause (immune complex deposition).
The nature of the imperfect repair is diverse in different tissues and organs and not always well understood. A definition of imperfect, ineffective, or inappropriate repair of damaged tissues or organs is that repair which leads to a loss of normal function of that tissue or organ. Sometimes, this imperfect repair leads to small (focal) lesions which can be compensated by surrounding healthy tissue, thus the tissue may overall function normally in an overall sense. However, if the injuries are repeated or chronic, these incremental decreases in function inexorably lead to total failure and catastrophic results.
Some of the most common examples of imperfect repair seen in many diverse tissues and organs are an increase in fibroid deposition and a proliferation of auxiliary cells at the site of injury. Initially the injury may cause a break in a continuous, fluid carrying system such as blood vessels, arteries, nephron tubules, or air passages. The cause of this break may be mechanical or the loss of normal, interfacing cells or destruction of matrix which forms the system. Whatever the cause, the attempt by the body to repair this break often takes the form of quickly covering the break physically with a wall of cells or matrix components. This physical covering of the break, while temporarily repairing the leakage, does not restore the normal function of the system in that affected area. The repair at the site of the injury usually lacks the biological properties of the original tissue, e.g., the loss of discriminatory filtration properties in the kidney, the loss of structural integrity in arteries and vessels, a loss of permeability in the airways of the lung, etc. Microscopic examinations of these imperfect repair sites often reveal the deposition of fibrin, collagen, and other molecules which lack the biological and/or physical properties of the original matrix which it has replaced. Similarly, there is often a proliferation of auxiliary cells (sometimes referred to as connective tissue cells) which produce more non-functioning, fibroid matrix cells. Lastly, there is often a proliferation of the normal and functional cells of the particular tissue; however, the proliferation, while beneficial in number, may be ineffective in total function due to the disruption of critical architecture. Thus, the overall loss of either chemically or biologically important matrix, loss of functional cells by replacement of repair cells, or a loss of critical architecture of functioning cells leads to the failure of the tissue or organ to perform its homeostatic function.
Additionally, there are often inappropriate responses to injury and repair. Prime examples are an immune-inflammatory or inflammatory responses at the site of injury. Although these responses are beneficial and critical to protect the body from many insults such as bacteria, viruses, or external pathogens, or are beneficial in removing dead or malfunctioning cells or matrix in normal circumstances, these responses can be inappropriately triggered or become out of control at repair sites. In some cases, an inappropriate response of certain cells may be causal to further damage as well as being detrimental to the repair. For example, in auto-immune diseases, immune complex deposition in various tissues and organs may cause local inflammation and damage, triggering a repair response and simultaneously causing the repair to be imperfect or ineffective.
A method of inhibiting imperfect tissue repair and physiological or pathological conditions caused at least in part thereby would be beneficical.
SUMMARY OF THE INVENTION
This invention provides methods for inhibiting imperfect tissue repair comprising administering to a human in need thereof an effective amount of a compound of formula I ##STR3## wherein R 1 and R 3 are independently hydrogen, --CH 3 , ##STR4## wherein Ar is optionally substituted phenyl; R 2 is selected from the group consisting of pyrrolidino, hexamethyleneimino, and piperidino; and pharmaceutically acceptable salts and solyates thereof.
Raloxifene, (the hydrochloride salt of a compound of formula 1, wherein R 1 and R 3 are hydrogen, and R 2 is 1-piperidinyl), and selected analogs are useful in the treatment of the syndromes associated with the imperfect, ineffective, or inappropriate repair of body tissues or organs resulting from acute, repeated acute, or chronic injury and are the subject of this invention.
DETAILED DESCRIPTION OF THE INVENTION
The current invention concerns the discovery that a select group of 2-phenyl-3-aroylbenzothiophenes (benzothiophenes), those of formula I, are useful for inhibiting imperfect tissue repair. The methods of treatment provided by this invention are practiced by administering to a human in need thereof a dose of a compound of formula I or a pharmaceutically acceptable salt or solrate thereof, that is effective to inhibit imperfect tissue repair.
The term "inhibit" is defined to include its generally accepted meaning which includes preventing, prohibiting, restraining, and slowing, stopping or reversing progression, or severity, and holding in check and/or treating existing characteristics. As such, the present method includes both medical therapeutic and/or prophylactic administrations, as appropriate.
The term "imperfect tissue repair" includes ineffective, inappropriate or inadequate tissue repair due to, at least in part, an insult to the tissue. The insult may be acute, repeated-acute or chronic, and includes inappropriate immune-inflammatory response, and results in loss of normal function of the tissue or organ.
Physiological conditions caused by or associated with imperfect tissue repair include those conditions which are due, at least in part, to the imperfect repair and therefor can be said to be a symptom of the imperfect tissue repair.
Generally, the compound is formulated with common excipients, diluents or carriers, and compressed into tablets, or formulated as elixirs or solutions for convenient oral administration, or administered by the intramuscular or intravenous routes. The compounds can be administered transdermally, and may be formulated as sustained release dosage forms and the like.
The compounds used in the methods of the current invention can be made according to established procedures, such as those detailed in U.S. Pat. Nos. 4,133,814, 4,418,068, and 4,380,635 all of which are incorporated by reference herein. In general, the process starts with a benzo b!thiophene having a 6-hydroxyl group and a 2-(4-hydroxyphenyl) group. The starting compound is protected, alkylated or acylated, and deprotected to form the formula I compounds. Examples of the preparation of such compounds are provided in the U.S. patents discussed above. Optionally substituted phenyl includes phenyl and phenyl substituted once or twice with C 1 -C 6 alkyl, C 1 -C 4 alkoxy, hydroxy, nitro, chloro, fluoro, or tri(chloro or fluoro)methyl.
The compounds used in the methods of this invention form pharmaceutically acceptable acid and base addition salts with a wide variety of organic and inorganic acids and bases and include the physiologically acceptable salts which are often used in pharmaceutical chemistry. Such salts are also part of this invention. Typical inorganic acids used to form such salts include hydrochloric, hydrobromic, hydroiodic, nitric, sulfuric, phosphoric, hypophosphoric and the like. Salts derived from organic acids, such as aliphatic mono and dicarboxylic acids, phenyl substituted alkanoic acids, hydroxyalkanoic and hydroxyalkandioic acids, aromatic acids, aliphatic and aromatic sulfonic acids, may also be used. Such pharmaceutically acceptable salts thus include acetate, phenylacetate, trifluoroacetate, acrylate, ascorbate, benzoate, chlorobenzoate, dinitrobenzoate, hydroxybenzoate, methoxybenzoate, methylbenzoate, o-acetoxybenzoate, naphthalene-2-benzoate, bromide, isobutyrate, phenylbutyrate, β-hydroxybutyrate, butyne-1,4-dioate, hexyne-1,4-dioate, caprate, caprylate, chloride, cinnamate, citrate, formate, fumarate, glycollate, heptanoate, hippurate, lactate, malate, maleate, hydroxymaleate, malonate, mandelate, mesylate, nicotinate, isonicotinate, nitrate, oxalate, phthalate, teraphthalate, phosphate, monohydrogenphosphate, dihydrogenphosphate, metaphosphate, pyrophosphate, propiolate, propionate, phenylpropionate, salicylate, sebacate, succinate, suberate, sulfate, bisulfate, pyrosulfate, sulfite, bisulfite, sulfonate, benzene-sulfonate, p-bromophenylsulfonate, chlorobenzenesulfonate, ethanesulfonate, 2-hydroxyethanesulfonate, methanesulfonate, naphthalene-1-sulfonate, naphthalene-2-sulfonate, p-toluenesulfonate, xylenesulfonate, tartarate, and the like. A preferred salt is the hydrochloride salt.
The pharmaceutically acceptable acid addition salts are typically formed by reacting a compound of formula I with an equimolar or excess amount of acid. The reactants are generally combined in a mutual solvent such as diethyl ether or benzene. The salt normally precipitates out of solution within about one hour to 10 days and can be isolatedby filtration or the solvent can be stripped off by conventional means.
Bases commonly used for formation of salts include ammonium hydroxide and alkali and alkaline earth metal hydroxides, carbonates, as well as aliphatic and primary, secondary and tertiary amines, aliphatic diamines. Bases especially useful in the preparation of addition salts include ammonium hydroxide, potassium carbonate, methylamine, diethylamine, ethylene diamine and cyclohexylamine.
The pharmaceutically acceptable salts generally have enhanced solubility characteristics compared to the compound from which they are derived, and thus are often more amenable to formulation as liquids or emulsions.
Pharmaceutical formulations can be prepared by procedures known in the art. For example, the compounds can be formulated with common excipients, diluents, or carriers, and formed into tablets, capsules, suspensions, powders, and the like. Examples of excipients, diluents, and carriers that are suitable for such formulations include the following: fillers and extenders such as starch, sugars, mannitot, and silicic derivatives; binding agents such as carboxymethyl cellulose and other cellulose derivatives, alginates, gelatin, and polyvinyl pyrrolidone; moisturizing agents such as glycerol; disintegrating agents such as calcium carbonate and sodium bicarbonate; agents for retarding dissolution such as paraffin; resorption accelerators such as quaternary ammonium compounds; surface active agents such as cetyl alcohol, glycerol monostearate; adsorptive carriers such as kaolin and bentonite; and lubricants such as talc, calcium and magnesium stearate, and solid polyethyl glycols.
The compounds can also be formulated as elixirs or solutions for convenient oral administration or as solutions appropriate for parenteral administration, for instance by intramuscular, subcutaneous or intravenous routes. Additionally, the compounds are well suited to formulation as sustained release dosage forms and the like. The formulations can be so constituted that they release the active ingredient only or preferably in a particular part of the intestinal tract, possibly over a period of time. The coatings, envelopes, and protective matrices may be made, for example, from polymeric substances or waxes.
The particular dosage of a compound of formula I required to inhibit imperfect tissue repair or physiological conditions due at least in part thereby, according to this invention, will depend upon the severity of the condition, the route of administration, and related factors that will be decided by the attending physician. Generally, accepted and effective daily doses will be from about 0.1 to about 1000 mg/day, and more typically from about 50 to about 600 mg/day. Such dosages will be administered to a subject in need of treatment from once to about three times each day, or more often as needed.
It is usually preferred to administer a compound of formula I in the form of an acid addition salt, as is customary in the administration of pharmaceuticals bearing a basic group, such as the piperidino ring. It is also advantageous to administer such a compound by the oral route. For such purposes the following oral dosage forms are available.
FORMULATIONS
In the formulations which follow, "active ingredient" means a compound of formula I.
______________________________________Formulation 1: Gelatin CapsulesHard gelatin capsules are prepared using the following:Ingredient Quantity (mg/capsule)______________________________________Active ingredient 0.1-1000Starch, NF 0-650Starch flowable powder 0-650Silicone fluid 350 centistokes 0-15______________________________________
The ingredients are blended, passed through a No. 45 mesh U.S. sieve, and filled into hard gelatin capsules.
Examples of specific capsule formulations of raloxifene that have been made include those shown below:
______________________________________Formulation 2: Raloxifene capsuleIngredient Quantity (mg/capsule)______________________________________Raloxifene 1Starch, NF 112Starch flowable powder 225.3Silicone fluid 350 centistokes 1.7______________________________________
______________________________________Formulation 3: Raloxifene capsuleIngredient Quantity (mg/capsule)______________________________________Raloxifene 5Starch, NF 108Starch flowable powder 225.3Silicone fluid 350 centistokes 1.7______________________________________
______________________________________Formulation 4: Raloxifene capsuleIngredient Quantity (mg/capsule)______________________________________Raloxifene 10Starch, NF 103Starch flowable powder 225.3Silicone fluid 350 centistokes 1.7______________________________________
______________________________________Formulation 5: Raloxifene capstileIngredient Quantity (mg/capsule)______________________________________Raloxifene 50Starch, NF 150Starch flowable powder 397Silicone fluid 350 centistokes 3.0______________________________________
The specific formulations above may be changed in compliance with the reasonable variations provided.
A tablet formulation is prepared using the ingredients below:
______________________________________Formulation 6: TabletsIngredient Quantity (mg/tablet)______________________________________Active ingredient 0.1-1000Cellulose, microcrystalline 0-650Silicon dioxide, fumed 0-650Stearate acid 0-15______________________________________
The components are blended and compressed to form tablets.
Alternatively, tablets each containing 0.1-1000 mg of active ingredient are made up as follows:
______________________________________Formulation 7: TabletsIngredient Quantity (mg/tablet)______________________________________Active ingredient 0.1-1000Starch 45Cellulose, microcrystalline 35Polyvinylpyrrolidone 4(as 10% solution in water)Sodium carboxymethyl cellulose 4.5Magnesium stearate 0.5Talc 1______________________________________
The active ingredient, starch, and cellulose are passed through a No. 45 mesh U.S. sieve and mixed thoroughly. The solution of polyvinylpyrrolidone is mixed with the resultant powders which are then passed through a No. 14 mesh U.S. sieve. The granules so produced are dried at 50°-60° C. and passed through a No. 18 mesh U.S. sieve. The sodium carboxymethyl starch, magnesium stearate, and talc, previously passed through a No. 60 U.S. sieve, are then added to the granules which, after mixing, are compressed on a tablet machine to yield tablets.
Suspensions each containing 0.1-1000 mg of medicament per 5 mL dose are made as follows:
______________________________________Formulation 8: SuspensionsIngredient Quantity (mg/5 ml)______________________________________Active ingredient 0.1-1000 mgSodium carboxymethyl cellulose 50 mgSyrup 1.25 mgBenzoic acid solution 0.10 mLFlavor q.v.Color q.v.Purified water to 5 mL______________________________________
The medicament is passed through a No. 45 mesh U.S. sieve and mixed with the sodium carboxymethyl cellulose and syrup to form a smooth paste. The benzoic acid solution, flavor, and color are diluted with some of the water and added, with stirring. Sufficient water is then added to produce the required volume.
For topical administration, the compounds may be formulated as is known in the art for direct application to an area. Conventional forms for this purpose include ointments, lotions, pastes, jellies, sprays, and aerosols. The percent by weight of a compound of the invention present in a topical formulation will depend on various factors, but generally will be from 0.5% to 95% of the total weight of the formulation, and typically 1-25% by weight.
The compositions can take the form of an aqueous or anhydrous solution or dispersion, or alternatively the form of an emulsion or suspension.
These compositions can contain pharmaceutically acceptable vehicles and adjuvants which are well known in the prior art. It is possible, for example, to prepare solutions using one or more organic solvent(s) that is/are acceptable from the physiological standpoint, chosen, in addition to water, from solvents such as acetone, ethanol, isopropyl alcohol, glycol ethers such as the products sold under the name "Dowanol", polyglycols and polyethylene glycols, C 1 -C 4 alkyl esters of short-chain acids, preferably ethyl or isopropyl lactate, fatty acid triglycerides such as the products marketed under the name "Miglyol", isopropyl myristate, animal, mineral and vegetable oils and polysiloxanes.
The compositions according to the invention can also contain thickening agents such as cellulose and/or cellulose derivatives. They can also contain gums such as xanthan, guar or carob gum or gum arabic, or alternatively polyethylene glycols, bentones and montmorillonites, and the like.
It is possible to add, if necessary, an adjuvant chosen from antioxidants, surfactants, other preservatives, film-forming, keratolytic or comedolytic agents, perfumes and colourings. Also, other active ingredients may be added, whether for the conditions described or some other condition.
For example, among antioxidants, t-butylhydroquinone, butylated hydroxyanisole, butylated hydroxytoluene and α-tocophrol and its derivatives may be mentioned. The galenical forms chiefly conditioned for topical application take the form of creams, milks, gels, dispersions or microemulsions, lotions thickened to a greater or lesser extent, impregnated pads, ointments or sticks, or alternatively the form of aerosol formulations in spray or foam form or alternatively in the form of a cake of soap.
The following topical compositions are prepared:
______________________________________Formulation 9Ingredient Quantity (mg/5 ml)______________________________________Hydroxypropylcellulose 1.5 gActive Ingredient 1.5-30 gIsopropanol qs 100 g______________________________________
______________________________________Formulation 10Ingredient Quantity (mg/5 ml)______________________________________Hydroxypropylcellulose 1.5 gEthyl lactate 15.0 gActive Ingredient 1.5-30 gIsopropanol qs 100 g______________________________________
______________________________________Formulation 11Ingredient Quantity (mg/5 ml)______________________________________Hydroxypropylcellulose 1.0 gButylated hydroxytoluene 0.02 gActive Ingredient 1.5-25 gEthanol qs 100 g______________________________________
______________________________________Formulation 12Ingredient Quantity (mg/5 ml)______________________________________Hydroxypropylcellulose 1.5 gButylated hydroxytoluene 0.01 gC.sub.8 -C.sub.12 fatty acid triglycerides 10.0 gActive Ingredient 1.5-30 gIsopropanol qs 100 g______________________________________
Formulations 9-12 take the form of gels.
______________________________________Formulation 13Ingredient Quantity (mg/5 ml)______________________________________Isopropanol 46.0 gActive Ingredient 1.0-15 gC.sub.8 -C.sub.12 fatty acid triglycerides 49.0 g______________________________________
______________________________________Formulation 14Ingredient Quantity (mg/5 ml)______________________________________Ethanol 69.0 gEthyl lactate 10.0 gActive Ingredient 1.5-20 gC.sub.8 -C.sub.12 fatty acid triglycerides 30.0 g______________________________________
______________________________________Formulation 15Ingredient Quantity (mg/5 ml)______________________________________Isopropanol 47.0 gAcetone 10.0 gEthyl lactate 10.0 gActive Ingredient 1-15 gC.sub.8 -C.sub.12 fatty acid triglycerides 30.0 g______________________________________
______________________________________Formulation 16Ingredient Quantity (mg/5 ml)______________________________________Ethanol 95.08 gButylated hydroxytoluene 0.02 gActive Ingredient 1.5-25 g______________________________________
Formulations 13, 14, 15, and 16 take the form of lotions.
______________________________________Formulation 17Ingredient Quantity (mg/5 ml)______________________________________White vaseline 50.0 gLiquid paraffin 15.0 gRefined paraffin wax 32.0 gActive Ingredient 1-20 g______________________________________
______________________________________Formulation 18Ingredient Quantity (mg/5 ml)______________________________________White vaseline 50.0 gLiquid paraffin 13.0 gRefined paraffin wax 32.0 gActive Ingredient 1-20 g______________________________________
Formulations 17 and 18 take the form of sticks.
Illustrations of the use of this invention will focus on conditions and pathologies effecting kidney, liver, vascular, and pulmonary function; however, this invention is in no way limited to these indications. In many cases due to the observation of an increase in fibrous matrix, many conditions are referred to in the art as fibrosis or fibrotic states, and this invention is not limited solely to pathologies or physiological conditions so named.
I. PATHOLOGIES OF THE KIDNEY
A. NEPHROTIC SYNDROME (NS)
The most general, clinical characteristics seen with patients suffering from NS are: albuminuria, hypoalbuminemia, hyperlipidemia, and edema. These abnormal clinical findings are the direct or indirect result of abnormal leakage of serum proteins into the urine and subsequent loss by excretion (proteinuria). Simplisticly this leakage and loss of serum proteins can be called a loss of the glomerular appartratus to selectively filter elements of the serum for excretion in urine; however, the actual mechanisms of this loss in filtration selectivity are diverse and complicated. These pathologies by which filtration failure occur are listed below and are connected with imperfect repair of damage inflicted, primarily on the epithelium of the glomerular apparatus.
The sequelae resulting from the loss of various serum proteins are numerous and serious. They are examples of the induction of pathology into other organs and tissues by an apparently unrelated failure in the kidney.
One of the major proteins lost in NS is albumin. The loss of albumin in the serum leads to a decrease in plasma oncotic pressure and has a negative impact on the Starling forces acting across the peripheral capillaries. The decrease in oncotic pressure and the imbalance of the Starling forces causes water to flow from the circulation into the interstitial tissues, especially in areas of low tissue pressure. This buildup of water in these tissues leads to an edematous state, causing decreased efficiency and/or failure of that tissue to function. Additionally, due to the lower effective volume of the plasma, the rennin-angiotensin-aldosterone system is activated leading to retention of salt and water, thus perpetuating the edematous state. Common sites affected by edema are the lungs and extremities. Edema is often associated with certain types of cardiovascular and pulmonary insufficiency and collapse. Current therapy for the treatment of edema of this origin are inadequate, and they include furosemide, ethacrynic acid and other loop diuretics and administration of salt-poor albumin. These treatments run the risk of causing acute renal failure or severe hypotension.
Another major sequelae of albumin loss is the inappropriate response of the liver to boast levels of LDL and cholesterol to compensate. This elevation of LDL and cholesterol can lead to an increase in atherosclerosis and other vascular diseases. Treatment with conventional lipid lowering agents for this aspect of NS is often not satisfactory due the compromise of renal function and subsequent toxicity of the therapy.
The loss of other serum proteins has other associated pathologies. For example, the loss of major quantities of transferrin can lead to certain types of anemia; the loss metal binding proteins leads to metabolic abnormalities; the loss of IgG leads to an increase in susceptibility to infectious agents; the loss of T4 leads to metabolic abnormalities; loss of cholecaciferol-binding protein leads to vitamin D deficiency, secondary hyperthyroidism, bone disease, and be contributory to hypocalcemia and hypocalciuria.
Another serious pathology associated with protein loss is thrombosis. The greater loss of antithrombin III relative to the pro-coagulating proteins may lead to a hypercoagulable state. Thrombosis and blockage of the vasculature to critical organs, especially the heart, lungs and kidney, are most serious.
Currently, there are numerous treatments for many of these conditions with various degrees of effectiveness; however, the situation can be further complicated by the fact that many useful drugs are carried by albumin in the circulation, thus reduction of albumin in NS changes the pharmacokinetics of these drugs making it difficult to manage the pathologies. Clearly, when dealing with such a cascade of events seen in NS, it would be useful to treat NS at the source of the problem, i.e., normalize the filtration selectivity in the kidney.
The primary cause of NS is primary glomerular disease (Idiopathic Nephrotic Syndrome). Primary glomerular disease is further classified into four main types: Minimal Change Disease (lipoid nephorosis, nil lesion, foot process disease); Focal and Segmental Glomerulosclerosis (focal sclerosis); Membranous Glomerulopathy; and Proliferative Glomerulonephritis (Membranoproliferative Glomerulonephritis, Cresentic Glomerulonephritis, "Pure" Mesangial Proliferative Glomerulonephritis, Focal and Segmental Proliferative Glomerulonephritis).
There are many conditions and diseases which cause NS in a secondary manner. These conditions and diseases inflict damage to the kidney which can be acute, repeated-acute, or chronic in nature: infectious agents (Streptococcal, infectious endocarditis, secondary syphilis, sepsis, leprosy, hepatitis B, mononucleosis, malaria, schistosomiasis, pneumoccal, mycoplasma, staphylococcal, and filariasis); Drug Toxicity (heroin abuse, probenicid, tridione, contrast media, anti-venoms and toxins, arthritis drugs-gold and penicillamine); Neoplastic Diseases (Hodgkin's, lymphomas, leukemias, carcinomas, melanoma, Wilm's tumor); Environmental toxins (natural or unnatural, such as mercury); or Multisystem Diseases (SLE, Schonlein-Henoch purpura, vasculitis, Goodpasture's Syndrome, dermatomyositis, amyloidosis, sarcoidosis, rheumatoid arthritis, Sjogren's Syndrome); Heredofamilial Diseases (diabetes mellitus, Alport's Syndrome, sickle-cell, Farbry's Disease); Other Diseases (Berger's Syndrome, thyroidiris, myxedema, malignant obesity, renovascular hypertension, chronic allograft rejection, bee stings).
The pathogenesis of each of the four major causes of NS are listed below. A central or contributing pathological event seen with most of these causes is an imperfect attempt to repair an injury which has lead to some type of non-functional properties of that repair or a loss of critical architecture.
1) Minimal Change Disease (MCD)
The pathogenesis and etiology of this disease is not known and cause of injury to the glomerular apparatus is not known. However, there is a profound loss of architecture in foot processes of the epithelial cells (podocytes). It is not clear whether this particular cause of NS is due to a repair fault or a failure in the function of the podocyte. Treatment of this disease often includes glucocorticoids, cylcophosphamide and chlorambucil, anti-proliferative and anti-inflammatory drugs, which are dangerous when used for prolonged periods of time.
2) Focal and Segmental Glomerulosclerosis (Focal Sclerosis)
In this disease, one cause of injury is thought to be igM complex deposition and C3 (complement factor III, a possible inflammatory substance) involvement. The tissue response is, again as in MCD, a loss of architecture of the podocytes and hyalinization of the glomeruli, a malfunction in matrix production. There is no effective treatment for this disease.
3) Membranous Glomerulopathy
In this disease, causes are known to be: IgG deposition, some infectious agents, tumors, heavy metals, or certain drugs. The resulting injury leads to discontinuous proteinaceous deposits on the subepithial aspect of the glomerular capillary wall, increased amounts and thickening of the basement membrane, all matrix defects. Treatment of this disease is limited to the use of glucocorticoids and this treatment is controversial as to its effectiveness.
4) Membranoproliferative Glomerulonephritis
This group of diseases has a common pathology of proliferation of mesangial cells and an increased synthesis of matrix. This response leads to the destruction of critical architecture and membrane selectivity and function. The cause of injury is due at least in part to Ig deposition. Treatment for this disease with glucocortocoid steroids may delay the progression of the disease, but is not satisfactory. Kidney transplants are also used to treat the disease; however, the prognosis is poor.
B. ACUTE GLOMERULONEPHRITIS (AGN)
AGN is characterized by rapid onset of proteinuria, hematuria, azotemia (insufficency of glomerular filteration rate), and salt and water retention. The major pathological sequelae induced by AGN are edema, circulatory congestion, and arterial diastolic hypertension. These pathologies can lead to failure of the lungs and cadio-vascular system. As the name implies, this condition is acute in nature and often quickly is resolved without extensive intervention; however, it can be most serious and lead to NS or chronic nephritis. The causes of AGN can be: infectious diseases- poststreptococcal glomerulonephritis, endocarditis, sepsis, pneumococcal pneumonia, typhoid fever, secondary syphilis, meningococcemia, hepatitis B, mononucleosis, mumps, measles, vaccinia, echovirus, and coxsackievirus; multisystem disease- SLE, vasculitis, Schonlein-Henoch purpura, Goodpasture's syndrome; primary glomerular disease; and other sources such as serum sickness.
The pathogenesis of AGN is somewhat different from NS and poorly understood; however, it often has lesions and similarities which suggest an imperfect response to an injury has occurred as seen in NS. Currently, the treatment of AGN with glucocorticoids is of questionable benefit. It would seem reasonable that a therapy for NS would be of use in some aspects of AGN.
C. RAPIDLY PROGRESSIVE GLOMERULONEPHRITIS (RPGN)
RPGN is similar to AGN with the exception that it rapidly leads to renal failure in a matter of weeks or months. The resulting sequelae are similar to those in AGN. The pathogenesis clearly shows extensive extra capillary cellular proliferation and destruction of architecture with "crescent" formation. Additionally, there is fibrin polymerization and focal discontinuities in the glomerular basement membranes. Treatment is supportive and insufficient. Agents which normalize epithelial proliferation and matrix production would be useful in this condition.
D. CHRONIC GLOMERULONEPHRITIS (CGN)
As the name suggests, this condition is characterized by persistent abnormalities and slow progressive loss of renal function. The most troublesome sequelae of CGN is hypertension and cardiovascular collapse. Cause of the disease is usually the protracted presence of NS. its pathogenesis is marked by cellular proliferation, sclerosing, and membrane and matrix abnormalities. Treatment is supportive and effectiveness is unsatisfactory. An agent which would normalize cellular proliferation and membrane-matrix function would be useful to treat CGN.
II. PATHOLOGIES OF THE LIVER
Cirrhosis of the liver is a serious pathology which involves the attempt of liver tissue to repair damage inflicted on it. Cirrhosis is often the end stage of many diseases which effect the liver and leads to hepatic insufficiency and failure. Cirrhosis, like nephrotic syndrome, shows the hallmarks of imperfect repair processes involving matrix, proliferative cellular, and architectual faults. Also, in many cases, an inappropriate inflammatory response is seen at the repair site, which can lead to further damage.
Cirrhosis, a general term, includes all forms of chronic diffuse liver diseases characterized by loss of hepatocytes, disorganization and fibrosis of the retculin network, disorganization of the vascular bed, and disorganization of the regenerating hepatocytes into nodules in the fibrous matrix. The precipitating event (damage) in cirrhosis is usually diffuse cell death from a number of causes listed below. The morphological changes induced by the attempt to repair this damage are wide spread and have serious consequences. For example, loss of functional hepatocytes leads to the sydrome of hepatic insufficiency- jaundice, central nervous system dysfunction (hepatic encephalopathy, coma), edema and ascites, and cachexia. Disorganization and distortion of the vascular and lymphatic beds can lead to portal hepatic hypertension and splenomegaly.
There are four major conditions recognized to precipitate the damage leading to cirrhosis of the liver:
1) Alcoholic Liver Disease and Cirrhosis
Alcoholic liver disease refers to a spectrum of liver injury and can be associated with acute, repeated acute, chronic alcoholism. There are three major components of this disease: fatty liver, alcoholic hepatitis, and alcoholic cirrhosis. All three may found in the same patient and may be independent of each other. Alcoholic cirrhosis is characterized by scarring, loss of hepatocytes, and nodular regeneration. At sites of damage there can be found fibroblasts (connective tissue cells) and collagen matrix. Alcoholic cirrhosis has also been called Laennec's, micronodular, portal, or fatty cirrhosis.
Treatment of alcoholic cirrhosis is supportive to the induced sequelae. Treatment of the dysfunctional liver is insufficient, but includes abstainance from alcohol and glucocorticoids.
2) Postnecrotic Cirrhosis
Postnecrotic cirrhosis is the most common type of cirrhosis and is marked by: extensive loss of hepatocytes, collapse of the stromal matrix and fibrosis producing large bands of connective tissue, and irregular nodules of regenerating cells, i.e., a condition of precipitating damage by cell death followedby a repair process which destroys the functional matrix and disorganizes architecture. Adding to the imperfect repair of the hepatic damage, there is often seen an inappropriate infilteration of imflammatory mononuclear cells which may cause further damage. Postnecrotic cirrhosis is also known in the art as toxic cirrhosis, coarsely nodular cirrhosis, posthepatic cirrhosis, cryptogenic cirrhosis, and multilobular cirrhosis.
The etiology of postnecrotic cirrhosis is not well understood; however, there is serologic evidence that viral hepatitis may be a common antecedent, especially Hepatitis B and non A-non B Hepatitis. Other pathologies leading to postnecrotic cirrhosis are: chemical toxins, e.g., phosphorous; toxins, e.g., Amantia phalloides; infections, e.g., brucellosis; parasitic infections, e.g., clonorchiasis; and advanced alcoholic liver disease. Additionally, patients with chronic active hepatitis (stemming from viral infection) may progress to postnecrotic cirrhosis.
Major sequelae of postnecrotic cirrhosis are similar to other types of cirrhosis, especially jaundice, ascites, abdomimal pain, hepatic encephalopathy, and portal hypertension. Treatment is supportive and treatment for underlying damage-repair pathology is not available.
3. Biliary Cirrhosis
The pathogensis and morphology is similar to postnecrotic cirrhosis, only the major lesions effect the bile ducts to a greater degree. The etiology of this condition is not known; however, since it is a disease of middle-aged women, there is a strong possiblity that it has an endocrine component.
Due to the blockage of the bile ducts and subsequent accumulation of bile products, the major sequelae are markedly different from other forms of cirrhosis. Often seen are: dark urine, itching of the skin, xanthelasmas of the joints and skin, hyperpigmentation, hyperlipidemia and malabsorption of lipid soluble vitamins. The malabsorption of vitamins A, K and D lead to osteomalacia, diarrhea, and purpura. Death is often caused by variceal hemorage, hepatic insufficiency, infection, and surgical attempts to open the bile ducts.
Treatment is either supportive or surgical proceedure, and there is no treatment for the underlying liver pathology.
4) Cardiac Cirrhosis
Cardiac cirrhosis is caused by chronic, severe right-sided congestive heart failure. This circulation failure precipitates hepatocyte necrosis and triggers the cirrhotic cascade. The only available treatment for cardiac cirrhosis is to correct the cardiac failure, if possible.
III. PATHOLOGIES OF THE CARDIO-VASCULAR SYSTEM
Arteriosclerosis is a general term for the thickening and hardening of the arterial wall. Atherosclerosis is a patchy nodular type of arteriosclerosis. The thickening of the arterial wall through the development of atherosclerotic plaque leads initially to restricted blood flow. A fissure or crack in this plaque initiates the development of a thrombus or clot which leads to tissue ischemia. If unresolved, the thrombus could lead to tissue and organ failure and possibly death. Examples of arterial thrombotic events include stroke, myocardial infarction and peripheral vascular diseases. Atherosclerosis is the underlying basis for cardiovascular disease being the leading cause of death and morbidity in the United States.
There are three types of lesions found in the arteries which are associated with atherosclerosis: fatty streaks, fibrous plaques, and complicated plaques. Fatty streaks occur early in life and consist of an accumulation of lipid filled macrophages (foam cells) and accumulated fibrous tissue on the intima. In general, these fatty streaks appear not to be particularly dangerous in themselves; however, they may be contributary to the formation of fibrous plaques. Fibrous plaques are raised lesions on the intima. These plaques consist of a central core of extracellular lipid and necrotic cell debris and covered with an overlayment of smooth muscle cells and collagen rich extracellular matrix. This makes the fibrous plaque foci, a place of constricted blood flow in the artery. The fibrous plaque is characteristic of advancing atherosclerotic disease. The complicated plaque is a calcified fibrous plaque and is an area of thrombosis, necrosis, and ulceration. This plaque can be the site of exclusive thrombosis which constricts the blood flow and cause stenosis and organ insufficiency. The site of a complicated plaque can also be an area of weakened arterial wall which can fail causing an anerurysm or hemorrhage.
One theory on the development of atherosclerosis is termed the "response to injury" hypothesis. According to this hypothesis, the vascular endothelial cells lining the artery are exposed to acute, repeated acute or chronic injury leading to endothelial cell dysfunction and in some cases cellular death, exposing the underlying medial and connective tissue beds. This break in the continuous system of endothelium can elicit platelet adhesion and aggregation with the formation of microthrombi. These events can cause the release of factors which can stimulate cellular proliferation, cellular migration and the production of extracellular matrix compounds all of which can contribute to an abnormal repair process. Although this repair corrects the immediate break in the system, repeated insults over a long period of time can lead to the development of atherosclerotic plaque at the site providing an example of imperfect, ineffective or inappropriate repair of a tissue in response to an initiating injury.
There are many risk factors which contribute to this atherogenic response, which include: hyperlipidemia (hypercholesterolemea and triglyceridemia), hypertension, cigarette smoking, hyperglycemia and diabetes mellitus, obesity, a sedentary lifestyle, stress, and family history of cardiovascular diseases. The current treatment of atherosclerotic disease is limited to cholesterol and triglyceride lowering drugs to modulate hyperlipidemia as well as many therapies designed to address thrombosis associated with atherosclerosis (i.e. aspirin). Lifestyle changes to eliminate contributing risk factors for vascular injury are also prescribed. There are no current therapies which address the defective repair process.
IV. PATHOLOGIES OF THE LUNG
The general term "infiltrative" means the diffusion into and accumulation in a tissue of those substances which are either foreign to it or endogenous substances which inhibit normal function. For example, infections (bacterial pneumonias) elicit immune or inflammatory cells into the interalveolar space or the invasive spread of neoplastic cells into the lung, these are foreign cells to the normal lung structure. In other cases endogenous substances such as hyaline membrane, fibrous matrix, and proliferation of normal alveolar and bronchial epithelial cells accumulate in the intraalweolar space leading to a dysfunctional foci in the lung.
In most cases, the lung is able to repair itself without lasting detrimental sequelae; however, if the injury is repeated acute or chronic in nature, the progressive number of non-functioning lesions (imperfect, ineffective, or inappropriate repair) begins to affect an insufficiency in pulmonary function. The pathogensis in this disease is very similar to the pathogenesis described for the liver, kidneys and vascular wall. As in the case of liver and kidney, the primary tissue which responds to the damage is the epithelium. The response of the epithelium is to quickly repair the damage to the alveolar-capillary interface with the production of fibrous matrix (collagen and hyaline membrane) and hyperplastic expansion of cells. This new structure, while restoring the barrier between the air (alveolar) and circulatory (capillary) spaces, is not able to selectively mediate the exchange of gases with the same effectivenes as the normal tissue.
The major sequelae of the accumulated loss and insufficiency of the lung is hypoxia of critical organs and their failure.
The initiating or antecedent pathologies of diffuse infiltrative lung disease are numerous and are listed in abrieviated form: Infections such as viral (influenza, CMV, etc.) bacterial (mycoplasma, streptococcal, staphylococcal, etc.) parasitic (schistosomiasis, Pneumocstis carinii, filariasis, etc.) fungal (histoplasmosis, candidis, etc.); Occupational causes such as mineral dusts and chemical fumes; Neoplasms; Congenital and familial pathologies such as cystic fibrosis; Metabolic diseases such as uremic pneumonitis and hypercalcemia; Physical trauma; Circulatory diseases such as thromboembolic and pulmonary edema; Immunological diseases such as hypersensitivity pneumonia; and Collagen diseases such as scleroderma, rheumatoid arthritis, SLE, etc.
Treatment of diffuse infiltrative lung disease is supportive treatment of the induced hypoxic complications and treatment of the initiating diseases. The treatment of the faulty repair process itself is mostly confined to the administration of corticosteroids, which in many cases are only partially effective and care must be taken not to induced the undersirable effects of the steroids.
V. PATHOLOGIES CAUSED BY THE REPAIR RESPONSE TO INFLAMMATORY DAMAGE
Inflammation is an important and beneficial response by the body to destroy invading pathogens (via the immune system) and scavenge dead or non-functional tissues or debris from the body. However, in some circumstances, this system becomes uncontrolled and the inflammatory process damages normal tissue. This damage can lead to an imperfect repair response. Often, this faulty repair response further initiates the inflammation and a vicious cycle is established leading to greater and greater dysfunction. Several examples of this chronic destructive cycle have been illustrated above. Further examples of instances where inflammatory initiated disease elicits imperfect repair response are: muscular dystrophies, scleroderma, and Crohn's Disease of the colon.
Raloxifene and selected analogs are useful in treating the imperfect repair of tissue and organs damaged by inflammation and is also a subject of this invention.
ASSAYS
Assay I
Between three and twenty patients suffering from diseases which are causing increasing symptoms of nephrotic syndrome are selected for clinical evaluation. The selection criterion for these patients are 1) preferably post-menopausal women, 2) patients suffering from diseases which often include the induction of nephrotic syndrome as part of the disease pathology, e.g., diabetes mellitus, hepatitis B, Sjogren's patients taking gold for rheumatoid arthritis, etc., 3) patients exhibiting a progressive increase in proteinuria, hypoalbuminemia, hyperlipidemia and edema. These patients are put on a protocol of 50-600 mg of a compound of formula I given by oral administration as a daily single or split dose. These patients continue this protocol for up to twelve months and at appropriate intervals, are evaluated as to the status of the progression of their proteinuria, hypoalbuminemia, hyperlipidemia or edema. A positive impact in this assay would be the slowing or reversing of the progression of these parameters.
Assay II
Between three and fifty patients suffering from diseases known to induce nephrotic syndrome or taking medications known to produce nephrotic syndrome are selected. The selection criterion for these patients is 1) preferably post-menopausal women, and 2) patients, which at the time of entry into the clinical trial, do not as yet demonstrate signs of nephrotic syndrome. Such patients might be women, 45-55 years of age, suffering from diabetes mellitus, but as yet show no signs of diabetic complications involving kidney function. Half of these patients are given a placebo. The other half are enrolled in a regiment of 50-600 mg of a compound of formula 1 given by oral administration per day as a single or split dose. This protocol continues for 1-5 years. A positive impact in this assay would be that, at the end of the trial period, the drug treated group will have fewer cases of pathologies associated with nephrotic syndrome, e.g., hyperlipidemia, proteinuria, hypoalbuminemia, or edema.
Assay III
Puromycin aminonucleoside (PA) nephrosis in the rat is a well-defined model of renal injury/repair ("Toxicology of the Kidney", ed. by J.B. Hook and R. S. Goldstein, Raven Press Ltd., New York, 1993). PA induces a nephrotic syndrome with selective proteinuria, hypoalbuminemia, and high plasma cholesterol. During the early stages of disease, glomerular filtration rate is also depressed. The model shares many clinical and morphological findings with human minimal change glomerulopathy and focal segmental glomerulosclerosis. Extracellular matrix (ECM) synthesis, deposition and organization are prominent in this injury/repair model and studies are initiated to probe this models possible utility for identifying agents which can positively effect tissue repair.
PA (6-dimethylaminopurine, 3-amino-d-ribose) is a purine antagonist with antibiotic activity. The drug inhibits protein synthesis by acting on the RNA synthesis at the level of the ribosome. In this model, proteinuria starts at 5 to 7 days after a single intravenous injection of 50 to 100 mg PA/kg body weight. The proteinuria reaches peak values averaging 300-900 mg/24 hr after 8 to 12 days, and dissipates within 3 weeks. Histological examination can detect moderate swelling of the glomerular visceral epithelial cells. When proteinuria ensues, these changes are accompanied by focal loss of covering epithelium outside the glomerular basement membrane.
Several investigators (Diamond et al., Kidney Intl., 33:917 (1988)) have speculated that certain histological features of focal and segmental glomerulonephrosis (FSGS) also resemble the lesion of atherosclerosis and may indicate a similar pathogenesis. In atherogenesis, the arterial intimal tissue thickens and is composed of vascular smooth muscle cells (VSMC), elastic and collagen fibers, and glycosaminoglycans lying beneath the endothelium. These thickened intimal regions contain isolated macrophage foam cells, and eventually, lipid-filled VSMC, and finally foci of necrosis appear. The similarities of FSCG includes; mesangial expansion with mesangial cell (MC) proliferation, mesangial foam cell accumulation, deposits of amorphous debris, necrosis of tissue, and eventual sclerosis. Glomerular MC and VSMC are closely related in terms of origin, microscopic anatomy, histochemistry, and contractility.
Acute 14 Day Renal Injury Model: Ovariectomized female Sprague Dawley rats are used, 200 to 250 gms. The animals are housed in metabolic cages for the duration of the experiment with collection of the urine every 24 hours for the measurement of total urinary protein concentration and renal excretion volume.
The rats are initialy anesthetized with ketamine/Rompun Xylazine! (0.2ml of a 1:2 mixture, i.m.) and are given an iv. injection of puromycin aminonucleoside (PA), 75 mg/kg, Sigma lot#90H4034! administered in 2.9 ml of saline over a 5 minute period in the tail vein using a HARVARD compact infusion pump equipped with a 5 ml syringe at a pump setting of 9 (approx. 2.9 ml/5 min.). The animals are dosed P.O. beginning DAY 0 to DAY 13 with a compound of formula 1 or 17 a-Ethynylestradiol (Sigma, E-4876, lot#112H0765) in 20% cyclodextrin.
Urine Protein Assay: Urine volumes from each rat are recorded daily and a 1 ml. sample is collected and frozen. The Pierce BCA protein assay is selected to determine the protein concentration of the urine. This method is highly sensitive for the spectrophotemetric determination of protein concentration. A standard curve is prepared by diluting a BSA standard solution (1 mg/ml, Pierce) with Dulbecco's Phosphate Buffered Saline (D-PBS) (Gibco). Using a multichannel pipet, the standard is diluted 1:2 down a Falcon 3911 Micro Test III flexible 96 well assay plate in duplicate wells, ending in a final concentration of 7.81 ug/ml.
Urine samples are thawed and a starting dilution of 1:5 is made in the Falcon plates using D-PBS. Samples are set-up in duplicate wells and resuspended 1:2 down the plate. Seven dilutions are made ending in a final dilution of 1:320. 10 ul of each diluted sample is removed from the Falcon microtiter plate using a multi-channel pipetter and added to a Immulon 2 flat bottom plate for developing and reading purposes.
A protein working reagent is prepared by combining 50 parts of BCA reagent A with 1 part of BCA reagent B (provided in the Pierce Assay Kit). 200 ul of working reagent is added to each well of the Immulon plate. The plates are covered and wrapped in aluminum foil and incubated at 60° C. for 30 minutes.
The plates are read on a Bio-Tek microplate autoreader interfaced with a Macintosh SE/30 personal computer at an absorbance of 570 nm. Data is obtained and calculated using the Delta Soft Elisa Analysis version 2.9B software provided by Bio-Tek Instruments.
Histology--GN Scores: On day 14, the animals are bled from the orbital sinus, sacrificed by CO 2 administration and the kidneys are removed, and processed for histological analysis. After 24 hour fixation, the kidneys are processed and embedded in paraffin. Cross-sections of each kidney (aprox. 3 u) are cut, stained with hematoxylin and eosin and 30 glomeruli/rat are scored according to the following criteria: (1+) <25% of the glomerulus affected; minimal damage; little or no matrix expansion. (2+) 25-50% affected; moderate damage; substantial increase or decrease in cellularity; capsule/tuft adhesions may be present; some capillary lumina collapse; thickened basement membranes; protein droplets may be found in the capsule. (3+) 51-75% affected; substantial damage; further increase in mesangial matrix; sclerosis; extensive collapse of capillary lumina with trapping of amorphous material. (4+) 76-100% affected; severe destruction; in most cases the glomerulus appears non-functional or necrotic; extensive sclerosis or lysis.
Crescent formation (defined as four or more contiguous epithelial cells of bowman's capsule) increases the score by 1+. A total score per kidney is determined by multiplying the degree of damage (1+ to 4+) by the percentage of the glomeruli with the same degree of injury, and then adding these scores together. The final GN score is obtained by the addition of the two kidney scores.
PCNA immunohistochemisty and proliferating cell index (PCI)
Identification of proliferating cell nuclear antigen (PCNA) positive proliferating cells is performed using a monoclonal mouse anti-PCNA antibody (Chemicon, #MAB424) and a biotin-streptavidin-horseradish peroxidase labeling system (KPL#710018) with diaminobenzidine as a chromogen. The PCI is determined by counting the number of positive cells/glomerulus in each of 30 glomeruli per kidney and then calculating the mean PCI/rat. No distinction is made between mesangial, endothelial or epithelial proliferating cell types.
Activity of compounds of formula 1 is illustrated by the amelioration of kidney damage or an indication of such, as determined above.
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A method of inhibiting imperfect tissue repair or a physiological condition due at least in part thereto comprising administering to a human in need thereof an effective amount of a compound having the formula ##STR1## wherein R 1 and R 3 are independently hydrogen, --CH 3 , ##STR2## wherein Ar is optionally substituted phenyl; R 2 is selected from the group consisting of pyrrolidine, hexamethyleneamino, and piperidino; or a pharmaceutically acceptable salt of solvate thereof.
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FIELD OF THE INVENTION
[0001] This invention relates in general to equipment for connecting a joint of casing to a string of casing suspended by spider at the rig floor, and in particular to a guide for guiding a casing gripper into the upper end of a joint of casing.
BACKGROUND OF THE INVENTION
[0002] Casing comprises pipe that is used to line a wellbore and is cemented in place. The casing may extend all the way to the wellhead at the top of the well, or it may extend up only to the lower end of a next upper string of casing. In the latter instance, the casing is typically referred to as a liner. The casing may be installed in a portion of the wellbore that has been previously drilled by drill pipe. Alternately, the casing may itself be used as the drill string to drill portions of the well.
[0003] In either event, the individual joints or sections of casing are secured to each other to make up a casing string being lowered into the well. When adding a new joint of casing to a string of casing, the string of casing will be supported by a spider at the rig floor. The spider has a set of slips that support the weight of the casing string. In one technique, the drilling rig has a top drive, which is a rotary power source that travels up and down the drilling rig. A casing gripper is secured to the quill or drive stem of the top drive. The casing gripper has radially moveable gripping elements that will grip either the inner diameter or outer diameter of the joint of casing. A set of links, also called bails, are mounted to the casing gripper to support a casing elevator below the lower end of the casing gripper. The elevator comprises a clamp that fits around the casing joint below the collar on the upper end of the casing joint. Hydraulic cylinders will pivot the bails outward to engage the next joint of casing, which may be spaced laterally from the spider and inclined on a ramp or V-door.
[0004] After clamping the elevator around the joint of casing, the driller raises the top drive and allows the links to swing back into vertical alignment with the top of the string of casing. The operator then lowers the top drive and the joint of casing until it lands on and is supported by the string of casing. The operator continues to lower the top drive and the casing gripper while the joint of casing remains supported on top of the string of casing. The gripping elements of the casing gripper will slide into or over the upper end of the joint of casing. Once in place, the operator actuates the casing gripper to grip the joint of casing, then rotates the gripping element to rotate the joint of casing and make it up with the string of casing.
[0005] In some instances, the elevator links are quite long because they must be able to pivot laterally outward to engage the next joint of casing as it is supported on the V-door. In large rigs, this lateral distance can be substantial. The operator may be able to adjust the length of the links or use longer links. However, longer links place the elevator several feet below the lower end of the casing gripper. This arrangement makes it difficult for the driller to stab the casing gripper into or over the upper end of the casing, particularly with small diameter casing. The upper end of the casing may be 35 to 40 feet above the driller when the stabbing has to occur, making it difficult to see. Having elevator a considerable distance below the casing gripper results in extra time required for making up a new joint of casing with the casing string.
SUMMARY OF THE INVENTION
[0006] In this invention, a guide is mounted to the links between the elevator and the casing gripping assembly. The guide has a central opening sized for receiving an upper end of the joint of casing to be connected to the string of casing. Preferably, this central opening is flared at its lower end so as to guide the upper end of the joint of casing as the casing gripper is lowered into or over it. The upper end of the opening may also be flared.
[0007] Optionally, a resilient centering device, such as bow springs or spring loaded roller balls, may be located in the guide opening to guide the upper end of the joint of casing. Optionally, a sensor may be mounted to or adjacent the guide for sensing when the gripper and the upper end of the joint of casing engage each other.
BRIEF DESCRIPTION OF THE DRAWINGS
[0008] FIGS. 1A and 1B comprise a side elevational view, partially sectioned, of a casing gripper having a guide in accordance with the invention and shown suspending a joint of casing above a string of casing.
[0009] FIGS. 2A and 2B comprise a side elevational view, partially sectioned, of the casing gripper of FIG. 1 , and showing the joint of casing being supported on but not yet secured to the string of casing.
[0010] FIGS. 3A and 3B comprise a side elevational view of the casing gripper of FIG. 1 , showing the joint of casing being gripped by the casing gripper and being made up to the string of casing.
DETAILED DESCRIPTION OF THE INVENTION
[0011] Referring to FIG. 1 , a casing gripper 11 includes an actuator portion and a spear 13 extending below and having a longitudinal axis 14 . Several gripping elements 15 are spaced circumferentially around spear 13 . In this example, gripping elements 15 are on cam or ramp surfaces of spear 13 . When the actuator portion of casing gripper 11 strokes gripping elements 15 , they will move radially outward. Alternately, they could be mounted within a housing surrounding spear 13 for radial inward movement when stroked. A seal 17 is located on spear 13 below gripping elements 15 in this embodiment. Spear 13 has a passage through it with an opening in a nose 19 for discharging drilling fluid.
[0012] A pair of bails or links 21 is mounted to casing gripper 11 . Links 21 have upper ends 23 that have cylindrical co-axial apertures for receiving axles (not shown) extending outward from opposite sides of casing gripper 11 . Hydraulic cylinders (not shown) will pivot links 21 about their upper ends 23 . Upper ends 23 and casing gripper 11 are preferably constructed as in U.S. Pat. No. 7 , 140 , 443 , so that each link 21 rotates in a single plane. Referring still to FIG. 1A , links 21 may have a fixed length. Alternately, the lengths of links 21 can be adjusted, then secured to a selected new length. In this embodiment, links 21 are adjusted by sliding portions relative to each other, then securing the portions by fasteners or pins 22 .
[0013] An elevator 25 is mounted to the lower ends of links 21 . Elevator 25 is a clamp that is radially opened and closed, either manually or hydraulically. Elevator 25 has an opening sized to loosely receive a joint of casing 27 . Joint 27 has a collar 29 on its upper end that has a larger diameter than the opening in elevator 25 , so that elevator 25 will lift casing joint 27 , but is also able to slide downward on casing joint 27 if the casing joint is stationarily supported. Casing joint 27 has a lower end that normally will have external threads 31 as shown in FIG. 1B .
[0014] Referring still to FIG. 1B , threaded end 31 is adapted to stab and be rotated into threaded engagement with a collar 33 located at the upper end of the uppermost casing joint of a casing string 35 . Casing string 35 is made up of joints of casing secured in the same manner as will be subsequently described. Casing string 35 is supported by a spider 37 located either flush with or on a rig floor 39 of a drilling rig. Spider 37 has slips that will grip the side wall of casing string 35 to support its weight.
[0015] A threaded stem 41 is located on the upper end of casing gripper 11 for rotating spear 13 relative to links 21 . Threaded stem 41 extends through the housing of casing gripper 11 and is supported by bearings so that it will rotate relative to the housing of casing gripper 11 . An anti-rotation device (not shown) prevents rotation of the housing of casing gripper 11 and links 21 . Threaded stem 41 secures to a drive stem or quill 43 of a top drive 45 ( FIG. 2A ). Top drive 45 is moveable up and down the derrick along one or more rails (not shown). Top drive 45 comprises a motor that is either hydraulically or electrically driven for rotating quill 43 .
[0016] A guide 47 is mounted to links 21 above elevator 25 and a short distance below nose 19 of gripper 11 when links 21 are vertical. Guide 47 extends between links 21 and preferably comprises at least two halves of a body that are clamped together by bolts 49 . Optionally, guide 47 may have a lower clamp 51 that is located below the body and separately clamped to links 21 . An opening 53 extends through the body of guide 47 . When links 21 are in the vertical position, the axis of the opening of elevator 25 is coaxial with axis 14 of spear 13 .
[0017] Opening 53 may have a flared upper portion 55 . In this embodiment, upper portion 55 is conical and has an increasing diameter in an upward direction. Similarly, opening 53 may have a flared lower portion 57 that increases in diameter in a downward direction. In this embodiment, lower flared portion 57 has a greater axial length than upper flared portion 55 and a greater diameter at its lower end than the upper end of upper flared portion 55 . In this example, lower flared portion 57 is defined by a plurality of blades or segments 52 spaced in a circular array around axis 14 with gaps between each segment 52 . The inner edges of segments 52 circumscribe or define flared lower portion 57 of opening 53 . The lower ends of segments 52 may be attached, such as by welding, to lower guide clamps 51 . The upper ends of segments 52 are also secured, such as by welding, to the body of guide 47 . Rather than blades or segments 52 , the lower flared portion 57 could be a conical bore formed by two mating halves of a body in the same manner as upper flared portion 55 .
[0018] Optionally, a resilient centering device or devices 59 may be mounted within the central portion of opening 53 . Centering devices 59 may comprise devices such as bow springs or roller balls that are biased by springs radially inward toward the axis of spear 13 .
[0019] In addition, a sensor 61 may be mounted to or adjacent guide 47 . Sensor 61 will detect the presence of collar 29 and provide a signal to the driller. Sensor 61 could be an optical device, such as one employing a laser beam that is interrupted by the presence of one of the collars 29 . Sensor 61 may include a transmitter for making a wireless transmission to a receiver located near or on the driller's control panel.
[0020] In operation, the operator picks up casing joint 27 in a conventional manner. Initially, casing joint 27 may be located laterally from spider 37 ( FIG. 1B ) and supported at an inclination by a V-door of the rig. The operator will tilt links 21 about upper ends 23 and relative to axis 14 and secure elevator 25 around casing joint 27 . The operator then lifts top drive 45 while allowing links 21 to pivot back to a vertical orientation, placing casing joint 27 in the position shown in FIG. 1A . The lower threaded end 31 of casing joint 27 will be spaced above collar 33 of the uppermost casing joint of casing string 35 . The distance from nose 19 to collar 29 on casing joint 27 may be several feet.
[0021] The operator then lowers top drive 45 until casing joint threaded end 31 lands in casing collar 33 , as shown in FIG. 2B . The portion of casing string 35 above spider 37 will support the weight of casing joint 27 at this point, but threads 31 are not yet made up to the internal threads in casing collar 33 . The operator continues lowering top drive 45 , which causes guide 47 to approach and receive casing joint collar 29 , as shown in FIG. 2A . Flared lower portion 57 will center casing collar 29 on axis 14 as guide 47 slides downward over casing collar 29 . At the point shown in FIG. 2A , nose 19 has begun to enter casing collar 29 . Guide 47 is positioned such that it will move over at least a part of the casing joint collar 29 before casing gripper nose 19 begins to enter casing joint 27 .
[0022] If sensor 61 is employed, it detects the presence of collar 29 as guide 47 moves below collar 29 . Sensor then informs the driller that nose 19 is now entering the bore of casing joint 27 . The driller continues lowering casing gripper 11 a short distance, at which time gripping elements 15 will be fully enclosed within casing joint 27 as shown in FIG. 3A . Optionally, the upper end of collar 29 will abut a stop when gripping elements 15 ( FIG. 2A ) are fully located within casing joint 27 .
[0023] The operator then supplies power to the actuator of casing gripper 11 , which causes gripping elements 15 ( FIG. 2A ) to move radially outward into gripping engagement with the inner diameter of casing joint 27 . The operator then supplies power to top drive 45 to rotate quill 43 , which in turn causes casing joint 27 to rotate. This results in threads 31 ( FIG. 2B ) making up to a desired torque with the threads in casing collar 33 , as shown in FIG. 3B .
[0024] At this point, collar 29 of casing joint 27 will be spaced several feet above guide 47 , and elevator 25 will be spaced several feet below casing joint collar 29 . The operator then lifts top drive 45 a short distance and releases spider 37 . Once released, the operator lowers top drive 45 , which lowers casing joint 27 and casing string 35 . When the upper end of casing joint 27 is near spider 37 , the operator actuates spider 37 to engage casing joint 27 , which is now the uppermost joint or section of casing string 35 . The operator releases elevator 25 , releases gripping elements 15 ( FIG. 2A ) and lifts top drive 45 while casing joint 27 is supported by spider 37 . Guide 47 will slide up past collar 29 , with flared upper portion 55 centering guide 47 relative to collar 29 to prevent damage to the lower edge of collar 29 . Once guide 47 is above collar 29 , the operator may then pivot links 21 outward to engage the next joint of casing.
[0025] The guide is particularly useful when the links are quite long, in that it centers the upper end of the casing joint with the casing gripper. The guide may be employed when running casing into a previously drilled wellbore and also when drilling with casing. Although shown in connection with an internal gripping mechanism, the same is applicable to an external casing gripper.
[0026] While the invention has been shown in only one of its forms, it should be apparent to those skilled in the art that it is not so limited but is susceptible to various changes without departing from the scope of the invention.
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A system for running a string of casing into a well utilizes a casing gripping assembly. The casing gripping assembly connects to a top drive and has radially movable gripping elements. A pair of links have upper ends pivotally connected to the casing gripping assembly. A casing elevator is mounted below the casing gripping assembly to lower ends of the links. A guide is mounted to the links between the elevator and the casing gripping assembly. The guide has a vertically extending central opening that has a lower portion that defines a flared entrance to the opening.
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BACKGROUND OF THE INVENTION
The invention relates to the treatment of neoplastic disorders such as cancer.
Cancer is a disease marked by the uncontrolled growth of abnormal cells. The abnormal cells may no longer do the work of normal cells, and they crowd out and destroy healthy tissue.
Lung cancer is the most common cancer-related cause of death among men and women. It is the second most commonly occurring cancer among men and women; it has been estimated that there will be more than 164,000 new cases of lung cancer in the U.S. in the year 2000 alone. While the rate of lung cancer cases is declining among men in the U.S., it continues to increase among women. Lung cancer can be lethal; according to the American Lung Association, an estimated 156,900 Americans are expected to die due to lung cancer in 2000.
Cancers that begin in the lungs are divided into two major types, non-small cell lung cancer and small cell lung cancer, depending on how the cells appear under a microscope. Non-small cell lung cancer (squamous cell carcinoma, adenocarcinoma, and large cell carcinoma) generally spreads to other organs more slowly than does small cell lung cancer. Small cell lung cancer is the less common type, accounting for about 20% of all lung cancer.
Other cancers include brain cancer, breast cancer, cervical cancer, colon cancer, gastric cancer, kidney cancer, leukemia, liver cancer, lymphoma, ovarian cancer, pancreatic cancer, prostate cancer, rectal cancer, sarcoma, skin cancer, testicular cancer, and uterine cancer. These cancers, like lung cancer, are sometimes treated with chemotherapy.
Chemotherapeutic drugs currently in use or in clinical trials include paclitaxel, docetaxel, tamoxifen, vinorelbine, gemcitabine, cisplatin, etoposide, topotecan, irinotecan, anastrozole, rituximab, trastuzumab, fludarabine, cyclophosphamide, gentuzumab, carboplatin, interferon, and doxorubicin. The most commonly used anticancer agent is paclitaxel, which is used alone or in combination with other chemotherapy drugs such as: 5-FU, doxorubicin, vinorelbine, cytoxan, and cisplatin.
SUMMARY OF THE INVENTION
We have discovered that the combination of one of the antihelmintic drugs albendazole, mebendazole, or oxibendazole and the antiprotozoal drug pentamidine exhibits substantial antiproliferative activity against cancer cells. Structural and functional analogs of each of these compounds are known, and any of these analogs can be used in the antiproliferative combinations of the invention. Metabolites of albendazole and pentamidine are also known. Many of these metabolites share one or more biological activities with the parent compound and, accordingly, can also be used in the antiproliferative combinations of the invention. Accordingly, the invention features a method for treating a patient having a cancer or other neoplasm, by administering to the patient (i) albendazole, mebendazole, or oxibendazole; and (ii) pentamidine simultaneously or within 14 days of each other in amounts sufficient to inhibit the growth of the neoplasm.
Preferably, the two compounds are administered within ten days of each other, more preferably within five days of each other, and most preferably within twenty-four hours of each other or even simultaneously. The cancer treated according to any of the methods of the invention, described below, can be lung cancer (squamous cell carcinoma, adenocarcinoma, or large cell carcinoma), brain cancer, breast cancer, cervical cancer, colon cancer, gastric cancer, kidney cancer, leukemia, liver cancer, lymphoma, ovarian cancer, pancreatic cancer, prostate cancer, rectal cancer, sarcoma, skin cancer, testicular cancer, or uterine cancer.
In a related aspect, the invention also features a method for treating a patient having a neoplasm such as cancer. In this method, the patient is administered (a) a first compound selected from albendazole, albendazole sulfonate, albendazole sulfone, albendazole sulfoxide, astemizole, benomyl, 2-benzimidazolylurea, benzthiazuron, cambendazole, cyclobendazole, domperidone, droperidol, fenbendazole, flubendazole, frentizole, 5-hydroxymebendazole, lobendazole, luxabendazole, mebendazole, methabenzthiazuron, mercazole, midefradil, nocodozole, omeprazole, oxfendazole, oxibendazole, parbendazole, pimozide, and tioxidazole (or a salt of any of the above), NSC181928 (ethyl 5-amino-1,2-dihydro-3-[(N-methylanilino)methyl]-pyrido[3,4-b]pyrazin-7-ylcarbamate), and TN-16 (3-(1-anilinoethylidene)-5-benzyl-pyrrodiline-2,4-dione); and (b) a second compound selected from pentamidine, propamidine, butamidine, heptamidine, nonamidine, stilbamidine, hydroxystilbamidine, diminazene, benzamidine, phenamidine, dibrompropamidine, 1,3-bis(4-amidino-2-methoxyphenoxy)propane, phenamidine, and amicarbalide (or a salt of any of the above). Alternatively, the second compound can be a functional analog of pentamidine, such as netropsin, distamycin, bleomycin, actinomycin, or daunorubicin. The first and second compounds are preferably administered simultaneously or within 14 days of each other and in amounts sufficient to inhibit the growth of the neoplasm.
In another related aspect, the invention also features a method for treating a patient having a neoplasm such as cancer by administering the following:
a) a first compound having the formula (I):
wherein:
R 1 is selected from the group consisting of:
R 2 is selected from the group consisting of:
each of R 3 and R 4 is independently selected from the group consisting of:
and
b) a second compound having the formula (II):
wherein each of Y and Z is, independently, O or N; each of R 5 and R 6 is, independently, —H, —OH, -halogen, —O—C 1-10 alkyl, —OCF 3 , —NO 2 , or NH 2 ; n is an integer between 2 and 6, inclusive; and each of R 7 and R 8 is, independently, at the meta or para position and is selected from the group consisting of:
wherein the first and second compounds are administered simultaneously or within 14 days of each other in amounts sufficient to inhibit the growth of the neoplasm.
In another related aspect, the invention also features a method for treating a patient having a neoplasm such as cancer by administering the following:
a) a first compound having the formula (III):
wherein:
A is selected from the group consisting of O, S, and NR 12 ;
R 9 is selected from the group consisting of:
each of R 10 and R 11 is independently selected from the group consisting of —H, -halo, —NO 2 , —OH, —SH, —O—C 1-10 alkyl, —O—(C 1-10 ) 0-1 -aryl, —O—(C 1-10 alkyl) 0-1 -heteroaryl, —O—(C 1-10 alkyl) 0-1 -heterocyclyl, —C 1-10 alkoxycarbonyl, —S(O) 0-2 —C 1-10 alkyl, —S(O) 0-2 —(C 1-10 alkyl) 0-1 -aryl, —S(O) 0-2 —(C 1-10 alkyl) 0-1 -heteroaryl, —S(O) 0-2 —C 1-10 alkyl) 0-1 -heterocyclyl, and —C 1-10 alkyl or —C 2-10 alkenyl that is unsubstituted or substituted by one or more substituents selected from the group consisting of -aryl, -heteroaryl, -heterocyclyl, —O—C 1-10 alkyl, —O—(C 1-10 alkyl) 0-1 -aryl, —O—(C 1-10 alkyl) 0-1 -heteroaryl, —O—(C 1-10 alkyl) 0-1 -heterocyclyl, —C 1-10 alkoxycarbonyl, —S(O) 0-2 —C 1-10 alkyl, —S(O) 0-2 —(C 1-10 alkyl) 0-1 -aryl, —S(O) 0-2 —(C 1-10 alkyl) 0-1 -heteroaryl, —S(O) 0-2 —(C 1-10 alkyl) 0-1 -heterocyclyl, —N(R 13 ) 2 , —OR 13 , -oxo, -cyano, -halogen, —NO 2 , —OH, and —SH;
R 12 is selected from the group consisting of —H and —C 1-10 alkyl or —C 2-10 alkenyl that is unsubstituted or substituted by one or more substituents selected from the group consisting of -aryl, -heteroaryl, -heterocyclyl, —O—C 1-10 alkyl, —O—(C 1-10 ) 0-1 -aryl, —O—(C 1-10 alkyl) 0-1 -heteroaryl, —O—(C 1-10 alkyl) 0-1 -heterocyclyl, —C 1-10 alkoxycarbonyl, —S(O) 0-2 —C 1-10 alkyl, —S(O) 0-2 -(C 1-10 alkyl) 0-1 -aryl, —S(O) 0-2 —(C 1-10 alkyl) 0-1 -heteroaryl, —S(O) 0-2 —(C 1-10 alkyl) 0-1 -heterocyclyl, —N(R 13 ) 2 , —OR 13 , -oxo, -cyano, -halo, —NO 2 , —OH, and —SH; and
each R 13 is independently selected from the group consisting of H and C 1-10 alkyl or C 2-10 alkenyl that is unsubstituted or substituted by one or more substituents selected from the group consisting of -aryl, -heteroaryl, -heterocyclyl, —O—C 1-10 alkyl, —O—(C 1-10 ) 0-1 -aryl, —O—(C 1-10 alkyl) 0-1 -heteroaryl, —O—(C 1-10 alkyl) 0-1 -heterocyclyl, —C 1-10 alkoxycarbonyl, -oxo, -cyano, -halo, —NO 2 , —OH, and —SH; and
b) a second compound having the formula (II):
wherein each of Y and Z is, independently, O or N; each of R 5 and R 6 is, independently, —H, —OH, -halogen, —O—C 1-10 alkyl, —OCF 3 , —NO 2 , or NH 2 ; n is an integer between 2 and 6, inclusive; and each of R 7 and R 8 is, independently, at the meta or para position and is selected from the group consisting of:
wherein the first and second compounds are administered simultaneously or within 14 days of each other in amounts sufficient to inhibit the growth of the neoplasm.
In any of the foregoing treatment methods, both compounds are preferably together in a pharmaceutical composition that also includes a pharmaceutically acceptable carrier. A benzimidazole is preferably administered at a dosage of 1 to 2500 milligrams and pentamidine is preferably administered at a dosage of 1 to 1000 milligrams. Suitable modes of administration include intravenous, intramuscular, inhalation, and oral administration.
The antiproliferative combinations of the invention can also be provided as components of a pharmaceutical pack. The two drugs can be formulated together or separately and in individual dosage amounts.
It will be understood by those in the art that the compounds are also useful when formulated as salts. For example, as is described herein, the isethionate salt of pentamidine exhibits synergistic antiproliferative activity when combined with a benzimidazole. Other salts of pentamidine include the platinum salt, the dihydrochloride salt, and the dimethanesulfonate salt (see, for example, Mongiardo et al., Lancet 2:108, 1989). Similarly, benzimidazole salts include, for example, halide, sulfate, nitrate, phosphate, phosphinate salts.
The invention also features a method for identifying compounds useful for treating a patient having a neoplasm. The method includes the steps of: contacting cancer cells in vitro with (i) pentamidine or a benzimidazole (or an analog of pentamidine or a benzimidazole) and (ii) a candidate compound, and determining whether the cancer cells grow more slowly than (a) cancer cells contacted with the benzimidazole or pentamidine but not contacted with the candidate compound, and (b) cancer cells contacted with the candidate compound but not with the benzimidazole or pentamidine. A candidate compound that, when combined with the benzimidazole or pentamidine, reduces cell proliferation but, in the absence of the benzimidazole or pentamidine, does not is a compound that is useful for treating a patient having a neoplasm.
Combination therapy according to the invention may be provided wherever chemotherapy is performed: at home, the doctor's office, a clinic, a hospital's outpatient department, or a hospital. Treatment generally begins at a hospital so that the doctor can observe the therapy's effects closely and make any adjustments that are needed. The duration of the combination therapy depends on the kind of cancer being treated, the age and condition of the patient, the stage and type of the patient's disease, and how the patient's body responds to the treatment. Drug administration may be performed at any of various intervals (e.g., daily, weekly, or monthly) and the dosage, frequency, and mode of administration of each agent can be determined individually. Combination therapy may be given in on-and-off cycles that include rest periods so that the patient's body has a chance to build healthy new cells and regain strength.
Depending on the type of cancer and its stage of development, the combination therapy can be used to treat cancer, to slow the spreading of the cancer, to slow the cancer's growth, to kill or arrest cancer cells that may have spread to other parts of the body from the original tumor, to relieve symptoms caused by the cancer, or to prevent cancer in the first place. Combination therapy can also help people live more comfortably by eliminating cancer cells that cause pain or discomfort.
As used herein, the terms “alkyl,” “alkenyl,” and the prefix “alk-” are inclusive of both straight chain and branched chain groups and of cyclic groups, i.e., cycloalkyl and cycloalkenyl groups. Cyclic groups can be monocyclic or polycyclic and preferably have from 3 to 10 ring carbon atoms, inclusive. Exemplary cyclic groups include cyclopropyl, cyclopentyl, cyclohexyl, and adamantyl groups.
The term “aryl” includes carbocyclic aromatic rings or ring systems. Examples of aryl groups include phenyl, naphthyl, biphenyl, fluorenyl, and indenyl groups. The term “heteroaryl” includes aromatic rings or ring systems that contain at least one ring hetero atom (e.g., O, S, N). Heteroaryl groups include furyl, thienyl, pyridyl, quinolinyl, tetrazolyl, and imidazo groups.
“Hetercyclyl” includes non-aromatic rings or ring systems that contain at least one ring hetero atom (e.g., O, S, N). Heterocyclic groups include, for example, pyrrolidinyl, tetrahydrofuranyl, morpholinyl, thiazolidinyl, and imidazolidinyl groups.
The aryl, heteroaryl, and heterocyclyl groups may be unsubstituted or substituted by one or more substituents selected from the group consisting of C 1-10 alkyl, hydroxy, halo, nitro, C 1-10 alkoxy, C 1-10 alkylthio, trihalomethyl, C 1-10 acyl, arylcarbonyl, heteroarylcarbonyl, nitrile, C 1-10 alkoxycarbonyl, oxo, arylalkyl (wherein the alkyl group has from 1 to 10 carbon atoms) and heteroarylalkyl (wherein the alkyl group has from 1 to 10 carbon atoms).
Compounds useful in the invention include those described herein in any of their pharmaceutically acceptable forms, including isomers such as diastereomers and enantiomers, salts, solvates, and polymorphs, thereof, as well as racemic mixtures of the compounds described herein.
Other features and advantages of the invention will be apparent from the following detailed description, and from the claims.
DETAILED DESCRIPTION OF THE INVENTION
We have discovered that the antihelmentic drugs albendazole, mebendazole, or oxibendazole in combination with the antiprotozoal drug pentamidine exhibit substantial antiproliferative activity against cancer cells. Concentrations that exhibited maximal antiproliferative activity against cancer cells were not toxic to normal cells. Thus, this drug combination is useful for the treatment of cancer and other neoplasms. We have also discovered that the combination of pentamidine isethionate with either exhibits similar antiproliferative activity.
Based on known properties that are shared among albendazole, mebendazole, and oxibendazole, their metabolites, and other benzimidazoles, as well as those shared among pentamidine and its analogs and metabolites, it is likely that structurally related compounds can be substituted for albendazole, mebendazole, and oxibendazole and for pentamidine in the antiproliferative combinations of the invention. Information regarding each of the drugs and its analogs and metabolites is provided below.
Benzimidazoles
Benzimidazoles that are useful in the antiproliferative combination of the invention are compounds having the general formula (I):
wherein:
R 1 is selected from the group consisting of H and C 1-10 alkyl or C 2-10 alkenyl that is unsubstituted or substituted by one or more substituents selected from the group consisting of -aryl, -heteroaryl, -heterocyclyl, —O-C 1-10 alkyl, —O—(C 1-10 ) 0-1 -aryl, —O—(C 1-10 alkyl) 0-1 -heteroaryl, —O—(C 1-10 alkyl) 0-1 -heterocyclyl, —C 1-10 alkoxycarbonyl, —S(O) 0-2 —C 1-10 alkyl, —S(O) 0-2 —(C 1-10 alkyl)0-1-aryl, —S(O) 0-2 —(C 1-10 alkyl) 0-1 -heteroaryl, —S(O) 0-2 —(C 1-10 alkyl) 0-1 -heterocyclyl, —N(R 13 ) 2 , —OR 13 , -oxo, -cyano, -halo, —NO 2 , —OH, and —SH;
R 2 is selected from the group consisting of:
each of R 3 and R 4 is independently selected from the group consisting of —H, -halo, —NO 2 , —OH, —SH, —O—C 1-10 alkyl, —O—(C 1-10 ) 0-1 -aryl, —O—(C 1-10 alkyl) 0-1 —heteroaryl, —O—(C 1-10 alkyl) 0-1 -heterocyclyl, —C 1-10 alkoxycarbonyl, —S(O) 0-2 —C 1-10 alkyl, —S(O) 0-2 —(C 1-10 alkyl) 0-1 -aryl, —S(O) 0-2 —(C 1-10 alkyl) 0-1 -heteroaryl, —S(O) 0-2 —(C 1-10 alkyl) 0-1 -heterocyclyl, and —C 1-10 alkyl or —C 2-10 alkenyl that is unsubstituted or substituted by one or more substituents selected from the group consisting of -aryl, -heteroaryl, -heterocyclyl, —O—C 1-10 alkyl, —O—(C 1-10 alkyl) 0-1 -aryl, —O—(C 1-10 alkyl) 0-1 -heteroaryl, —O—(C 1-10 alkyl) 0-1 -heterocyclyl, —C 1-10 alkoxycarbonyl, —S(O) 0-2 —C 1-10 alkyl, —S(O) 0-2 —(C 1-10 alkyl) 0-1 -aryl, —S(O) 0-2 —(C 1-10 alkyl) 0-1 -heteroaryl, —S(O) 0-2 —(C 1-10 alkyl) 0-1 -heterocyclyl, —N(R 13 ) 2 , —OR 13 , -oxo, -cyano, -halogen, —NO 2 , —OH, and —SH; and
each R 13 is selected from the group consisting of H and C 1-10 alkyl or C 2-10 alkenyl that is unsubstituted or substituted by one or more substituents selected from the group consisting of-aryl, -heteroaryl, -heterocyclyl, —O—C 1-10 alkyl, —O—(C 1-10 ) 0-1 -aryl, —O—(C 1-10 alkyl) 0-1 -heteroaryl, —O—(C 1-10 alkyl) 0-1 -heterocyclyl, —C 1-10 alkoxycarbonyl, -oxo, -cyano, -halo, —NO 2 , —OH, and —SH.
Examples of substituents R 1 , R 3 , and R 4 are provided below.
R 1
R 3 and R 4
One of the most commonly prescribed members of the benzimidazole family is albendazole, which has the structure:
Albendazole is currently available as an oral suspension and in tablets.
Albendazole Metabolites
Albendazole undergoes metabolic transformation into a number of metabolites that may be therapeutically active; these metabolites may be substituted for albendazole in the antiproliferative combination of the invention. The metabolism of albendazole can yield, for example, albendazole sulfonate, albendazole sulfone, and albendazole sulfoxide.
Benzimidazole Analogs
Analogs of benzimidazoles include benzothioles and benzoxazoles having the structure of formula IV:
wherein:
B is O or S;
R 9 is selected from the group consisting of:
and each of R 10 and R 11 is independently selected from the group consisting of —H, -halo, —NO 2 , —OH, —SH, —O—C 1-10 alkyl, —O—(C 1-10 ) 0-1 -aryl, —O—(C 1-10 alkyl) 0-1 -heteroaryl, —O—(C 1-10 alkyl) 0-1 -heterocyclyl, —C 1-10 alkoxycarbonyl, —S(O) 0-2 —C 1-10 alkyl, —S(O) 0-2 -(C 1-10 alkyl) 0-1 -aryl, —S(O) 0-2 -(C 1-10 alkyl) 0-1 -heteroaryl, —S(O) 0-2 —(C 1-10 alkyl) 0-1 -heterocyclyl, and —C 1-10 alkyl or —C 2-10 alkenyl that is unsubstituted or substituted by one or more substituents selected from the group consisting of -aryl, -heteroaryl, -heterocyclyl, —O-C 1-10 alkyl, —O—(C 1-10 alkyl) 0-1 -aryl, —O—(C 1-10 alkyl) 0-1 -heteroaryl, —O—(C 1-10 alkyl) 0-1 -heterocyclyl, -C 1-10 alkoxycarbonyl, —S(O) 0-2 —C 1-10 alkyl, —S(O) 0-2 —(C 1-10 alkyl) 0-1 -aryl, —S(O) 0-2 —(C 1-10 alkyl) 0-1 -heteroaryl, —S(O) 0-2 —(C 1-10 alkyl) 0-1 -heterocyclyl, —N(R 13 ) 2 , —OR 13 , -oxo, -cyano, -halogen, —NO 2 , —OH, and —SH; and
each R 13 is independently selected from the group consisting of H and C 1-10 alkyl or C 2-10 alkenyl that is unsubstituted or substituted by one or more substituents selected from the group consisting of -aryl, -heteroaryl, -heterocyclyl, —O—C 1-10 alkyl, —O—(C 1-10 ) 0-1 -aryl, —O—(C 1-10 alkyl) 0-1 -heteroaryl, —O—(C 1-10 alkyl) 0-1 -heterocyclyl, —C 1-10 alkoxycarbonyl, -oxo, -cyano, -halo, —NO 2 , —OH, and —SH.
Suitable benzimidazoles and benzimidazole analogs for use in the methods of the invention include astemizole, benomyl, 2-benzimidazolylurea, benzthiazuron, cambendazole, cyclobendazole, domperidone, droperidol, fenbendazole, flubendazole, frentizole, 5-hydroxymebendazole, lobendazole, luxabendazole, mebendazole, methabenzthiazuron, mercazole, midefradil, nocodozole, omeprazole, oxfendazole, oxibendazole, parbendazole, pimozide, and tioxidazole.
Some benzimidazoles and benzimidazole analogs fit the following formula (III).
wherein:
A is selected from the group consisting of O, S, and NR 12 ;
R 9 R 10 , R 11 , and R 13 are as described above for formula (IV);
R 12 is selected from the group consisting of —H and —C 1-10 alkyl or —C 2-10 alkenyl that is unsubstituted or substituted by one or more substituents selected from the group consisting of -aryl, -heteroaryl, -heterocyclyl, —O—C 1-10 alkyl, —O—(C 1-10 ) 0-1 -aryl, —O—(C 1-10 alkyl) 0-1 -heteroaryl, —O—(C 1-10 alkyl) 0-1 -heterocyclyl, —C 1-10 alkoxycarbonyl, —S(O) 0-2 —C 1-10 alkyl, —S(O) 0-2 —(C 1-10 alkyl) 0-1 -aryl, —S(O) 0-2 —(C 1-10 alkyl) 0-1 -heteroaryl, —S(O) 0-2 —(C 1-10 alkyl) 0-1 -heterocyclyl, —N(R 13 ) 2 , —OR 13 , -oxo, -cyano, -halo, —NO 2 , —OH, and —SH; and
Pentamidine
Pentamidine is currently used for the treatment of Pneumocystis carinii, Leishmania donovani, Trypanosoma brucei, T. gambiense, and T. rhodesiense infections. The structure of pentamidine is:
It is available formulated for injection or inhalation. For injection, pentamidine is packaged as a nonpyrogenic, lyophilized product. After reconstitution, it is administered by intramuscular or intravenous injection.
Pentamidine isethionate is a white, crystalline powder soluble in water and glycerin and insoluble in ether, acetone, and chloroform. It is chemically designated 4,4′-diamidino-diphenoxypentane di(β-hydroxyethanesulfonate). The molecular formula is C 23 H 36 N 4 O 10 S 2 and the molecular weight is 592.68.
The antiprotozoal mode of action of pentamidine is not fully understood. In vitro studies with mammalian tissues and the protozoan Crithidia oncopelti indicate that the drug interferes with nuclear metabolism, causing inhibition of the synthesis of DNA, RNA, phospholipids, and proteins.
Little is also known about the drug's pharmacokinetics. In one published study, seven patients treated with daily i.m. doses of pentamidine at 4 mg/kg for 10 to 12 days were found to have plasma concentrations between 0.3 and 0.5 μg/mL. The patients continued to excrete decreasing amounts of pentamidine in urine up to six to eight weeks after cessation of treatment.
Tissue distribution of pentamidine has been studied in mice given a single intraperitoneal injection of pentamidine at 10 mg/kg. The concentration in the kidneys was the highest, followed by that in the liver. In mice, pentamidine was excreted unchanged, primarily via the kidneys with some elimination in the feces. The ratio of amounts excreted in the urine and feces (4:1) was constant over the period of study.
Pentamidine Analogs
Aromatic diamidino compounds can replace pentamidine in the antiproliferative combination of the invention. These compounds are referred to as pentamidine analogs. Examples are propamidine, butamidine, heptamidine, and nonamidine, all of which, like pentamidine, exhibit antipathogenic or DNA binding properties. Other analogs (e.g., stilbamidine and indole analogs of stilbamidine, hydroxystilbamidine, diminazene, benzamidine, dibrompropamidine, 1,3-bis(4-amidino-2-methoxyphenoxy) propane (DAMP), netropsin, distamycin, phenamidine, amicarbalide, bleomycin, actinomycin, and daunorubicin) also exhibit properties in common with pentamidine. It is likely that these compounds will have antiproliferative activity when administered in combination with a benzimidazole (or an analog or metabolite of a benzimidazole).
Suitable analogs are those falling within formula (II).
wherein each of Y and Z is, independently, —O— or —N—; each of R 5 and R 6 is, independently, —H, —OH, —Cl, —Br, —F, —OCH 3 , —OCF 3 , —NO 2 , or —NH 2 ; n is an integer between 2 and 6, inclusive; and each of R 7 and R 8 is, independently, at the meta or para position and is selected from the group consisting of:
Other suitable pentamidine analogs include stilbamidine (G-1) and hydroxystilbamidine (G-2), and their indole analogs (e.g., G-3):
Each amidine moiety may independently be replaced with one of the moieties depicted as D-2, D-3, D-4, or D-5, above. As is the case for the benzimidazoles and pentamidine, salts of stilbamidine, hydroxystilbamidine, and their indole derivatives are also useful in the method of the invention. Preferred salts include, for example, dihydrochloride and methanesulfonate salts.
Pentamidine Metabolites
Pentamidine metabolites are also useful in the antiproliferative combination of the invention. Pentamidine is rapidly metabolized in the body to at least seven primary metabolites. Some of these metabolites share one or more activities with pentamidine. It is likely that some pentamidine metabolites will exhibit antiproliferative activity when combined with a benzimidazole or an analog thereof.
Seven pentamidine metabolites are shown below.
Therapy
The combinations of compounds of the invention are useful for the treatment of neoplasms. Combination therapy may be performed alone or in conjunction with another therapy (e.g., surgery, radiation, chemotherapy, biologic therapy). Additionally, a person having a greater risk of developing a neoplasm (e.g., one who is genetically predisposed or one who previously had a neoplasm) may receive prophylactic treatment to inhibit or delay neoplastic formation.
The dosage and frequency of administration of each component of the combination can be controlled independently. For example, one compound may be administered orally three times per day, while the second compound may be administered intramuscularly once per day. The compounds may also be formulated together such that one administration delivers both compounds. Formulations and dosages are described further below.
Formulation of Pharmaceutical Compositions
The administration of each compound of the combination may be by any suitable means that results in a concentration of the compound that, combined with the other component, is anti-neoplastic upon reaching the target region. The compound may be contained in any appropriate amount in any suitable carrier substance, and is generally present in an amount of 1-95% by weight of the total weight of the composition. The composition may be provided in a dosage form that is suitable for the oral, parenteral (e.g., intravenously, intramuscularly), rectal, cutaneous, nasal, vaginal, inhalent, skin (patch), or ocular administration route. Thus, the composition may be in form of, e.g., tablets, capsules, pills, powders, granulates, suspensions, emulsions, solutions, gels including hydrogels, pastes, ointments, creams, plasters, drenches, delivery devices, suppositories, enemas, injectables, implants, sprays, or aerosols. The pharmaceutical compositions may be formulated according to conventional pharmaceutical practice (see, e.g., Remington: The Science and Practice of Pharmacy, (19th ed.) ed. A. R. Gennaro, 1995, Mack Publishing Company, Easton, Pa. and Encyclopedia of Pharmaceutical Technology, eds. J. Swarbrick and J. C. Boylan, 1988-1999, Marcel Dekker, New York.
Pharmaceutical compositions according to the invention may be formulated to release the active compound substantially immediately upon administration or at any predetermined time or time period after administration. The latter types of compositions are generally known as controlled release formulations, which include (i) formulations that create a substantially constant concentration of the drug within the body over an extended period of time; (ii) formulations that after a predetermined lag time create a substantially constant concentration of the drug within the body over an extended period of time; (iii) formulations that sustain drug action during a predetermined time period by maintaining a relatively, constant, effective drug level in the body with concomitant minimization of undesirable side effects associated with fluctuations in the plasma level of the active drug substance (sawtooth kinetic pattern); (iv) formulations that localize drug action by, e.g., spatial placement of a controlled release composition adjacent to or in the diseased tissue or organ; and (v) formulations that target drug action by using carriers or chemical derivatives to deliver the drug to a particular target cell type.
Administration of compounds in the form of a controlled release formulation is especially preferred in cases in which the compound, either alone or in combination, has (i) a narrow therapeutic index (i.e., the difference between the plasma concentration leading to harmful side effects or toxic reactions and the plasma concentration leading to a therapeutic effect is small; in general, the therapeutive index, TI, is defined as the ratio of median lethal dose (LD 50 ) to median effective dose (ED 50 )); (ii) a narrow absorption window in the gastro-intestinal tract; or (iii) a very short biological half-life so that frequent dosing during a day is required in order to sustain the plasma level at a therapeutic level.
Any of a number of strategies can be pursued in order to obtain controlled release in which the rate of release outweighs the rate of metabolism of the compound in question. In one example, controlled release is obtained by appropriate selection of various formulation parameters and ingredients, including, e.g., various types of controlled release compositions and coatings. Thus, the drug is formulated with appropriate excipients into a pharmaceutical composition that, upon administration, releases the drug in a controlled manner. Examples include single or multiple unit tablet or capsule compositions, oil solutions, suspensions, emulsions, microcapsules, microspheres, nanoparticles, patches, and liposomes.
Solid Dosage Forms for Oral Use
Formulations for oral use include tablets containing the active ingredient(s) in a mixture with non-toxic pharmaceutically acceptable excipients. These excipients may be, for example, inert diluents or fillers (e.g., sucrose, sorbitol, sugar, mannitol, microcrystalline cellulose, starches including potato starch, calcium carbonate, sodium chloride, lactose, calcium phosphate, calcium sulfate, or sodium phosphate); granulating and disintegrating agents (e.g., cellulose derivatives including microcrystalline cellulose, starches including potato starch, croscarmellose sodium, alginates, or alginic acid); binding agents (e.g., sucrose, glucose, sorbitol, acacia, alginic acid, sodium alginate, gelatin, starch, pregelatinized starch, microcrystalline cellulose, magnesium aluminum silicate, carboxymethylcellulose sodium, methylcellulose, hydroxypropyl methylcellulose, ethylcellulose, polyvinylpyrrolidone, or polyethylene glycol); and lubricating agents, glidants, and antiadhesives (e.g., magnesium stearate, zinc stearate, stearic acid, silicas, hydrogenated vegetable oils, or talc). Other pharmaceutically acceptable excipients can be colorants, flavoring agents, plasticizers, humectants, buffering agents, and the like.
The tablets may be uncoated or they may be coated by known techniques, optionally to delay disintegration and absorption in the gastrointestinal tract and thereby providing a sustained action over a longer period. The coating may be adapted to release the active drug substance in a predetermined pattern (e.g., in order to achieve a controlled release formulation) or it may be adapted not to release the active drug substance until after passage of the stomach (enteric coating). The coating may be a sugar coating, a film coating (e.g., based on hydroxypropyl methylcellulose, methylcellulose, methyl hydroxyethylcellulose, hydroxypropylcellulose, carboxymethylcellulose, acrylate copolymers, polyethylene glycols and/or polyvinylpyrrolidone), or an enteric coating (e.g., based on methacrylic acid copolymer, cellulose acetate phthalate, hydroxypropyl methylcellulose phthalate, hydroxypropyl methylcellulose acetate succinate, polyvinyl acetate phthalate, shellac, and/or ethylcellulose). Furthermore, a time delay material such as, e.g., glyceryl monostearate or glyceryl distearate may be employed.
The solid tablet compositions may include a coating adapted to protect the composition from unwanted chemical changes, (e.g., chemical degradation prior to the release of the active drug substance). The coating may be applied on the solid dosage form in a similar manner as that described in Encyclopedia of Pharmaceutical Technology, supra.
The two drugs may be mixed together in the tablet, or may be partitioned. In one example, the first drug is contained on the inside of the tablet, and the second drug is on the outside, such that a substantial portion of the second drug is released prior to the release of the first drug.
Formulations for oral use may also be presented as chewable tablets, or as hard gelatin capsules wherein the active ingredient is mixed with an inert solid diluent (e.g., potato starch, lactose, microcrystalline cellulose, calcium carbonate, calcium phosphate or kaolin), or as soft gelatin capsules wherein the active ingredient is mixed with water or an oil medium, for example, peanut oil, liquid paraffin, or olive oil. Powders and granulates may be prepared using the ingredients mentioned above under tablets and capsules in a conventional manner using, e.g., a mixer, a fluid bed apparatus or a spray drying equipment.
Controlled Release Oral Dosage Forms
Controlled release compositions for oral use may, e.g., be constructed to release the active drug by controlling the dissolution and/or the diffusion of the active drug substance.
Dissolution or diffusion controlled release can be achieved by appropriate coating of a tablet, capsule, pellet, or granulate formulation of compounds, or by incorporating the compound into an appropriate matrix. A controlled release coating may include one or more of the coating substances mentioned above and/or, e.g., shellac, beeswax, glycowax, castor wax, carnauba wax, stearyl alcohol, glyceryl monostearate, glyceryl distearate, glycerol palmitostearate, ethylcellulose, acrylic resins, dl-polylactic acid, cellulose acetate butyrate, polyvinyl chloride, polyvinyl acetate, vinyl pyrrolidone, polyethylene, polymethacrylate, methylmethacrylate, 2-hydroxymethacrylate, methacrylate hydrogels, 1,3 butylene glycol, ethylene glycol methacrylate, and/or polyethylene glycols. In a controlled release matrix formulation, the matrix material may also include, e.g., hydrated metylcellulose, carnauba wax and stearyl alcohol, carbopol 934, silicone, glyceryl tristearate, methyl acrylate-methyl methacrylate, polyvinyl chloride, polyethylene, and/or halogenated fluorocarbon.
A controlled release composition containing one or more of the compounds of the claimed combinations may also be in the form of a buoyant tablet or capsule (i.e., a tablet or capsule that, upon oral administration, floats on top of the gastric content for a certain period of time). A buoyant tablet formulation of the compound(s) can be prepared by granulating a mixture of the drug(s) with excipients and 20-75% w/w of hydrocolloids, such as hydroxyethylcellulose, hydroxypropylcellulose, or hydroxypropylmethylcellulose. The obtained granules can then be compressed into tablets. On contact with the gastric juice, the tablet forms a substantially water-impermeable gel barrier around its surface. This gel barrier takes part in maintaining a density of less than one, thereby allowing the tablet to remain buoyant in the gastric juice.
Liquids for Oral Administration
Powders, dispersible powders, or granules suitable for preparation of an aqueous suspension by addition of water are convenient dosage forms for oral administration. Formulation as a suspension provides the active ingredient in a mixture with a dispersing or wetting agent, suspending agent, and one or more preservatives. Suitable dispersing or wetting agents are, for example, naturally-occurring phosphatides (e.g., lecithin or condensation products of ethylene oxide with a fatty acid, a long chain aliphatic alcohol, or a partial ester derived from fatty acids) and a hexitol or a hexitol anhydride (e.g., polyoxyethylene stearate, polyoxyethylene sorbitol monooleate, polyoxyethylene sorbitan monooleate, and the like). Suitable suspending agents are, for example, sodium carboxymethylcellulose, methylcellulose, sodium alginate, and the like.
Parenteral Compositions
The pharmaceutical composition may also be administered parenterally by injection, infusion or implantation (intravenous, intramuscular, subcutaneous, or the like) in dosage forms, formulations, or via suitable delivery devices or implants containing conventional, non-toxic pharmaceutically acceptable carriers and adjuvants. The formulation and preparation of such compositions is well-known to those skilled in the art of pharmaceutical formulation. Formulations can be found in Remington: The Science and Practice of Pharmacy, supra.
Compositions for parenteral use may be provided in unit dosage forms (e.g., in single-dose ampoules), or in vials containing several doses and in which a suitable preservative may be added (see below). The composition may be in form of a solution, a suspension, an emulsion, an infusion device, or a delivery device for implantation, or it may be presented as a dry powder to be reconstituted with water or another suitable vehicle before use. Apart from the active drug(s), the composition may include suitable parenterally acceptable carriers and/or excipients. The active drug(s) may be incorporated into microspheres, microcapsules, nanoparticles, liposomes, or the like for controlled release. Furthermore, the composition may include suspending, solubilizing, stabilizing, pH-adjusting agents, and/or dispersing agents.
As indicated above, the pharmaceutical compositions according to the invention may be in the form suitable for sterile injection. To prepare such a composition, the suitable active drug(s) are dissolved or suspended in a parenterally acceptable liquid vehicle. Among acceptable vehicles and solvents that may be employed are water, water adjusted to a suitable pH by addition of an appropriate amount of hydrochloric acid, sodium hydroxide or a suitable buffer, 1,3-butanediol, Ringer's solution, and isotonic sodium chloride solution. The aqueous formulation may also contain one or more preservatives (e.g., methyl, ethyl or n-propyl p-hydroxybenzoate). In cases where one of the compounds is only sparingly or slightly soluble in water, a dissolution enhancing or solubilizing agent can be added, or the solvent may include 10-60% w/w of propylene glycol or the like.
Controlled Release Parenteral Compositions
Controlled release parenteral compositions may be in form of aqueous suspensions, microspheres, microcapsules, magnetic microspheres, oil solutions, oil suspensions, or emulsions. Alternatively, the active drug(s) may be incorporated in biocompatible carriers, liposomes, nanoparticles, implants, or infusion devices.
Materials for use in the preparation of microspheres and/or microcapsules are, e.g., biodegradable/bioerodible polymers such as polyglactin, poly-(isobutyl cyanoacrylate), poly(2-hydroxyethyl-L-glutamnine) and, poly(lactic acid). Biocompatible carriers that may be used when formulating a controlled release parenteral formulation are carbohydrates (e.g., dextrans), proteins (e.g., albumin), lipoproteins, or antibodies.
Materials for use in implants can be non-biodegradable (e.g., polydimethyl siloxane) or biodegradable (e.g., poly(caprolactone), poly(lactic acid), poly(glycolic acid) or poly(ortho esters)).
Rectal Compositions
For rectal application, suitable dosage forms for a composition include suppositories (emulsion or suspension type), and rectal gelatin capsules (solutions or suspensions). In a typical suppository formulation, the active drug(s) are combined with an appropriate pharmaceutically acceptable suppository base such as cocoa butter, esterified fatty acids, glycerinated gelatin, and various water-soluble or dispersible bases like polyethylene glycols and polyoxyethylene sorbitan fatty acid esters. Various additives, enhancers, or surfactants may be incorporated.
Compositions for Inhalation
For administration by inhalation, typical dosage forms include nasal sprays and aerosols. In a typically nasal formulation, the active ingredient(s) are dissolved or dispersed in a suitable vehicle. The pharmaceutically acceptable vehicles and excipients (as well as other pharmaceutically acceptable materials present in the composition such as diluents, enhancers, flavoring agents, and preservatives) are selected in accordance with conventional pharmaceutical practice in a manner understood by the persons skilled in the art of formulating pharmaceuticals.
Percutaneous and Topical Compositions
The pharmaceutical compositions may also be administered topically on the skin for percutaneous absorption in dosage forms or formulations containing conventionally non-toxic pharmaceutical acceptable carriers and excipients including microspheres and liposomes. The formulations include creams, ointments, lotions, liniments, gels, hydrogels, solutions, suspensions, sticks, sprays, pastes, plasters, and other kinds of transdermal drug delivery systems. The pharmaceutically acceptable carriers or excipients may include emulsifying agents, antioxidants, buffering agents, preservatives, humectants, penetration enhancers, chelating agents, gelforming agents, ointment bases, perfumes, and skin protective agents.
Examples of emulsifying agents are naturally occurring gums (e.g., gum acacia or gum tragacanth) and naturally occurring phosphatides (e.g., soybean lecithin and sorbitan monooleate derivatives). Examples of antioxidants are butylated hydroxy anisole (BHA), ascorbic acid and derivatives thereof, tocopherol and derivatives thereof, butylated hydroxy anisole, and cysteine. Examples of preservatives are parabens, such as methyl or propyl p-hydroxybenzoate, and benzalkonium chloride. Examples of humectants are glycerin, propylene glycol, sorbitol, and urea. Examples of penetration enhancers are propylene glycol, DMSO, triethanolamine, N,N-dimethylacetamide, N,N-dimethylformamide, 2-pyrrolidone and derivatives thereof tetrahydrofurfuryl alcohol, and AZONE™. Examples of chelating agents are sodium EDTA, citric acid, and phosphoric acid. Examples of gel forming agents are CARBOPOL™, cellulose derivatives, bentonite, alginates, gelatin and polyvinylpyrrolidone. Examples of ointment bases are beeswax, paraffin, cetyl palmitate, vegetable oils, sorbitan esters of fatty acids (Span), polyethylene glycols, and condensation products between sorbitan esters of fatty acids and ethylene oxide (e.g., polyoxyethylene sorbitan monooleate (TWEEN™)).
The pharmaceutical compositions described above for topical administration on the skin may also be used in connection with topical administration onto or close to the part of the body that is to be treated. The compositions may be adapted for direct application or for introduction into relevant orifice(s) of the body (e.g., rectal, urethral, vaginal or oral orifices). The composition may be applied by means of special drug delivery devices such as dressings or alternatively plasters, pads, sponges, strips, or other forms of suitable flexible material.
Controlled Release Percutaneous and Topical Compositions
There are several approaches for providing rate control over the release and transdermal permeation of a drug, including: membrane-moderated systems, adhesive diffusion-controlled systems, matrix dispersion-type systems, and microreservoir systems. A controlled release percutaneous and/or topical composition may be obtained by using a suitable mixture of the above-mentioned approaches.
In a membrane-moderated system, the active drug is present in a reservoir which is totally encapsulated in a shallow compartment molded from a drug-impermeable laminate, such as a metallic plastic laminate, and a rate-controlling polymeric membrane such as a microporous or a non-porous polymeric membrane (e.g., ethylene-vinyl acetate copolymer). The active compound is only released through the rate-controlling polymeric membrane. In the drug reservoir, the active drug substance may either be dispersed in a solid polymer matrix or suspended in a viscous liquid medium such as silicone fluid. On the external surface of the polymeric membrane, a thin layer of an adhesive polymer is applied to achieve an intimate contact of the transdermal system with the skin surface. The adhesive polymer is preferably a hypoallergenic polymer that is compatible with the active drug.
In an adhesive diffusion-controlled system, a reservoir of the active drug is formed by directly dispersing the active drug in an adhesive polymer and then spreading the adhesive containing the active drug onto a flat sheet of substantially drug-impermeable metallic plastic backing to form a thin drug reservoir layer. A matrix dispersion-type system is characterized in that a reservoir of the active drug substance is formed by substantially homogeneously dispersing the active drug substance in a hydrophilic or lipophilic polymer matrix and then molding the drug-containing polymer into a disc with a substantially well-defined surface area and thickness. The adhesive polymer is spread along the circumference to form a strip of adhesive around the disc.
In a microreservoir system, the reservoir of the active substance is formed by first suspending the drug solids in an aqueous solution of water-soluble polymer, and then dispersing the drug suspension in a lipophilic polymer to form a plurality of microscopic spheres of drug reservoirs.
Dosages
The dosage of each compound of the claimed combinations depends on several factors, including: the administration method, the disease to be treated, the severity of the disease, whether the disease is to be treated or prevented, and the age, weight, and health of the person to be treated.
The compounds are preferably administered in an amount of about 0.1-30 mg/kg body weight per day, and more preferably in an amount of about 0.5-15 mg/kg body weight per day. As described above, the compound in question may be administered orally in the form of tablets, capsules, elixirs or syrups, or rectally in the form of suppositories. Parenteral administration of a compound is suitably performed, for example, in the form of saline solutions or with the compound incorporated into liposomes. In cases where the compound in itself is not sufficiently soluble to be dissolved, a solubilizer such as ethanol can be applied. Below, for illustrative purposes, the dosages for benzimidazoles and pentamidine are described. One in the art will recognize that if a second compound is substituted for either a benzimidazole or pentamidine, the correct dosage can be determined by examining the efficacy of the compound in cell proliferation assays, as well as its toxicity in humans.
Oral Administration
For a benzimidazole adapted for oral administration for systemic use, the dosage is normally about 1 mg to 1000 mg per dose administered (preferably about 5 mg to 500 mg, and more preferably about 10 mg to 300 mg) one to ten times daily (preferably one to five times daily) for one day to one year, and may even be for the life of the patient; because the combinations of the invention function primarily as cytostatic rather than cytotoxic agents, and exhibit low toxicity, chronic, long-term administration will be indicated in many cases. Dosages up to 8 g per day may be necessary.
For pentamidine, the dosage is normally about 0.1 mg to 300 mg per dose administered (preferably about 1 mg to 100 mg) one to four times daily for one day to one year, and, like a benzimidazole, may be administered for the life of the patient. Administration may also be given in cycles, such that there are periods during which time pentamidine is not administered. This period could be, for example, about a day, a week, a month, or a year or more.
Rectal Administration
For compositions adapted for rectal use for preventing disease, a somewhat higher amount of a compound is usually preferred. Thus a dosage of a benzimidazole is normally about 5 mg to 2000 mg per dose (preferably about 10 mg to 1000 mg, more preferably about 25 mg to 500 mg) administered one to four times daily. Treatment durations are as described for oral admininstration. The dosage of pentamidine is as described for orally admininstered pentamidine.
Parenteral Administration
For intravenous or intramuscular administration of a benzimidazole, a dose of about 0.1 mg/kg to about 100 mg/kg body weight per day is recommended, a dose of about 1 mg/kg to about 25 mg/kg is preferred, and a dose of 1 mg/kg to 10 mg/kg is most preferred. Pentamidine is administered at a dose of about 0.1 mg/kg to about 20 mg/kg, preferably at a dose of about 0.5 mg/kg to about 10 mg/kg, and more preferably at a dose of about 1 mg/kg to about 4 mg/kg.
Each compound is usually administered daily for up to about 6 to 12 months or more. It may be desirable to administer a compound over a one to three hour period; this period may be extended to last 24 hours or more. As is described for oral administration, there may be periods of about one day to one year or longer during which at least one of the drugs is not administered.
Inhalation
For inhalation, a benzimidazole is administered at a dose of about 1 mg to 1000 mg daily, and preferably at a dose of about 10 mg to 500 mg daily. For pentamidine, a dose of about 10 mg to 1000 mg, and preferably at a dose of 30 mg to 600 mg, is administered daily.
Percutaneous Administration
For topical administration of either compound, a dose of about 1 mg to about 5 g administered one to ten times daily for one week to 12 months is usually preferable.
The following examples are to illustrate the invention. They are not meant to limit the invention in any way.
EXAMPLE 1
Preparation of the Albendazole/Pentamidine Isethionate Dilution Matrix
Stock solutions of albendazole and pentamidine isethionate (Sigma catalog number A4673 and P0547, respectively) were made in dimethylsulfoxide (DMSO) at concentrations of 15.07 mM and 6.74 mM respectively. An 8× stock solution (128 μM) of each individual compound was made in Dulbecco's Modified Eagle Medium (DMEM) (Gibco 11995-040) containing 10% fetal bovine serum (FBS), 200 mM L-glutamine, and 1% antibiotic/antimycotic solution. From this a 2-fold dilution series was made in DMEM. This series provided nine concentrations ranging from 64 μM to 240 nM, and one concentration of 0 M. The compound mixture matrix was prepared by filling columns of a 384-well plate with the dilution series of pentamidine isethionate (first column: 32 μM; second column: 16 μM; third column: 8 μM; fourth column: 4 μM; fifth column: 2 μM; sixth column: 1 μM; seventh column: 500 nM; eighth column: 250 nM; ninth column: 125 nM; and tenth column: no compound) and filling the rows with the dilution series of albendazole (first row: 32 μM; second row: 16 μM; third row: 8 μM; fourth row: 4 μM; fifth row: 2 μM; sixth row: 1 μM; seventh row: 500 nM; eighth row: 250 nM; ninth row: 125 nM; and tenth row: no compound) using a 16-channel pipettor (Finnpipette). This compound mixture plate provided 4× concentrations of each compound that are transferred to assay plates. The dilution matrix thus contained 100 different points—81 wells where varying amounts of a benzimidazole and pentamidine were present, as well as a ten-point dilution series (2-fold) for each individual compound.
EXAMPLE 2
Assay for Antiproliferative Activity of Albendazole and Pentamidine Isethionate
The compound dilution matrix was assayed using the A549 bromodeoxyuri dine (BrdU) cytoblot method. Forty-five microliters of a suspension containing A549 lung adenocarcinoma cells (ATCC# CCL-1 85) was seeded in a white opaque polystyrene cell culture treated sterile 384-well plate (NalgeNunc #164610) using a multidrop (Labsystems) to give a density of 3000 cells per well. Fifteen microliters of the 4× compound mixture matrix was added to each well of the plate containing the cells. The compound mixture matrix was transferred using a 16-channel pipettor (Finnpipette). In addition, control wells with paclitaxel (final concentration 4.6 μM), podophyllotoxin (9.6 μM), and quinacrine (8.5 μM) were added to each plate. Each experiment was conducted in triplicate plates.
After incubation for 48 hours at 37° C., BrdU was added to each well at a concentration of 10 μM. After 16 hours, the media was aspirated and the cells were fixed by the addition of 70% ethanol and phosphate-buffered saline (PBS) at room temperature for 1 hour. The fixative was aspirated and 2N HCl with Tween 20 (polyoxyethylene sorbitan monolaurate) was added to each well and the plates were incubated for 20 minutes at room temperature. The HCl was neutralized with a solution of 2N NaOH and the cells were washed twice with Hank's Balanced Salt Solution (HBSS) and once with PBS containing 0.5% bovine serum albumin (BSA) and 0.1% Tween 20. The wash solution was removed and mouse anti-BrdU primary antibody (PharMingen #555627) was diluted 1:1000 in PBS containing BSA, Tween 20, and secondary antibody at a dilution of 1:2000 (Amersham #NA931). The secondary antibody recognizes the mouse antibody and is conjugated to the enzyme horseradish peroxidase (HRP). After one hour of incubation, the antibody solution was removed and the cells washed once with PBS. After the PBS wash, the HRP substrate (which contains luminol, hydrogen peroxide, and an enhancer such as para-iodophenol) was added to each well. The plates were read using an LJL Analyst. All aspirations as well as the washes with PBS and HBSS were performed using a TECAN™ Power Washer 384. The amount of light output from each well indicates the amount of DNA synthesis that occurred in that well. Decreased light indicates antiproliferative action of the compounds.
Luminescence for each position in the albendazole/pentamidine isethionate dilution matrix was divided into the luminescence values for A549 cells treated with only DMSO vehicle, providing antiproliferative ratios for each position in the albendazole/pentamidine isethionate dilution matrix. Antiproliferative ratios were also calculated for paclitaxel, podophyllotoxin, and quinacrine and used for comparison.
TABLE 1
Albendazole
Concentrations
Pentamidine Isethionate Concentrations (μM)
(μM)
8
4
2
1
0.5
0.25
0.13
0.06
0.03
0
8
7.4
8.0
5.7
5.2
6.2
6.5
4.5
4.1
4.3
3.1
4
9.9
9.5
9.4
8.9
6.8
4.9
3.7
3.0
2.4
2.4
2
8.7
5.8
7.0
5.1
4.3
4.0
3.2
2.8
3.1
2.5
1
6.6
5.7
5.5
4.6
3.4
3.1
2.9
2.1
1.9
1.4
0.5
6.9
5.9
4.8
3.9
2.3
1.7
1.9
1.5
1.3
1.2
0.25
5.5
5.5
4.9
3.1
1.9
1.5
1.4
1.4
1.2
1.3
0.13
4.5
4.2
3.0
1.8
1.4
1.2
1.2
1.2
1.1
1.2
0.06
3.3
3.2
2.2
1.5
1.1
1.0
1.1
1.0
1.1
0.9
0.03
4.0
3.2
2.0
1.4
1.3
1.4
1.2
1.2
1.0
1.3
0
2.5
2.2
1.9
1.3
1.1
1.2
0.9
1.0
1.0
0.9
At 2.0 μM, pentamidine isethionate alone yields an antiproliferative ratio of 1.9 (i.e., inhibition of 47% of growth) and this increases to a ratio of 2.2 (inhibition of 55% of growth) when the concentration is doubled to 4.0 μM. Two micromolar albendazole yields a ratio of 2.5 (inhibition of 60% of growth), and this is increased no further by doubling the concentration to 4.0 μM. When 2.0 μM pentamidine isethionate is tested in combination with 2.0 μM albendazole (4.0 μM total compound species), an antiproliferative ratio of 7.0 is achieved (inhibition of 85.7% of growth). Thus, a combination of albendazole and pentamidine isethionate yields an antiproliferative ratio higher than that seen for paclitaxel (4.0), an effect that was not achieved by either drug alone.
In another analysis, the potency of the single compounds is shifted by the presence of the other compound. The maximal antiproliferative ratio achieved by albendazole alone was 3.1 (at 8.0 μM). A similar antiproliferative ratio was observed when 1 μM pentamidine isethionate was combined with albendazole at concentrations as low as 250 nM, significantly reducing the total drug species needed to achieve this effect.
EXAMPLE 3
Assay for Antiproliferative Activity of Pentamidine Isethionate in Combination with Albendazole Sulfoxide, Mebendazole, Oxibendazole, or Thiabendazole
Because albendazole shares antihelmentic activity with other benzimidazoles, we tested the combination of pentamidine isethionate with benzimidazoles mebendazole, oxibendazole, albendazole sulfoxide, and thiabendazole (Tables 2-5). The assays were performed as described in Example 2, above. In the case of mebendazole and oxibendazole, the combination of the benzimidazole with pentamidine resulted in greater antiproliferative activity than that that achieved by either drug alone (Tables 2 and 3).
The combination of thiabendazole and pentamidine isethionate did not result in greater antiproliferative activity than either drug alone (Table 4). These results are consistent with the findings by Gupta ( Mol. Pharmacol. 30:142-148, 1986) of a lack of cross-resistance of the nocodozole-resistant NocR and Podrii6 cell lines to thiabendazole (but not to other benzimidazoles tested), indicating that the mechanism of action of this compound is different from that of other benzimidazoles.
TABLE 2
Mebendazole
Pentamidine Isethionate Concentrations (μM)
Concentrations (μM)
4
2
1
0.5
0.25
0.13
0.06
0.03
0.015
0
4
12.2
9.8
6.2
4.5
5.1
4.6
4.9
5.0
4.5
4.4
2
14.3
12.2
6.7
5.5
4.7
5.4
5.0
6.0
5.1
5.0
1
8.9
10.9
7.8
4.1
3.7
3.6
3.7
3.9
3.9
3.4
0.5
10.2
11.5
6.5
4.7
3.3
3.4
3.0
3.1
3.0
2.8
0.25
6.6
5.9
3.8
1.7
1.5
1.5
1.4
1.5
1.6
1.5
0.13
5.7
4.6
2.4
1.5
1.3
1.3
1.2
1.4
1.4
1.5
0.06
4.5
3.4
1.9
1.1
1.0
1.0
1.1
0.9
1.2
1.0
0.03
5.4
5.1
2.3
1.5
1.4
1.3
1.3
1.4
1.3
1.4
0.015
5.1
3.2
1.9
1.1
1.1
1.0
1.0
0.9
1.2
1.0
0
5.7
4.1
2.4
1.5
1.2
1.4
1.2
1.4
1.6
1.7
TABLE 3
Oxibendazole
Pentamidine Isethionate Concentrations (μM)
Concentrations (μM)
4
2
1
0.5
0.25
0.13
0.06
0.03
0.015
0
4
6.7
6.6
4.6
3.7
3.9
3.6
3.7
3.8
3.7
3.6
2
6.3
6.6
4.9
3.5
3.0
2.8
2.5
3.5
2.9
3.2
1
5.2
6.4
4.8
3.2
3.1
2.7
3.0
3.1
3.3
2.9
0.5
5.0
5.8
3.9
2.7
2.6
2.8
1.5
1.7
1.7
1.6
0.25
5.0
4.1
3.5
1.5
1.2
1.2
1.1
1.0
1.2
1.0
0.13
4.0
3.8
2.1
1.2
1.1
1.1
1.1
1.1
1.0
1.1
0.06
3.6
3.0
1.8
1.0
1.0
1.1
1.1
1.0
1.3
1.0
0.03
3.5
3.0
1.7
1.2
1.0
1.1
1.0
1.2
0.9
1.1
0.015
3.9
2.8
1.9
1.1
1.0
1.0
1.0
0.9
1.0
1.0
0
4.1
2.9
1.6
1.3
0.9
1.1
1.1
1.0
1.1
1.2
TABLE 4
Thiabendazole
Pentamidine Isethionate Concentrations (μM)
Concentrations (μM)
4
2
1
0.5
0.25
0
4
4.1
2.4
1.5
1.2
1.2
1.2
2
4.5
3.0
1.4
1.1
1.1
1.2
1
4.1
2.9
1.8
1.0
1.2
1.2
0.5
3.3
3.1
1.6
1.0
1.3
1.2
0.25
3.5
3.4
1.4
1.1
1.1
1.2
0
3.7
3.0
1.7
1.1
1.1
1.2
TABLE 5
Albendazole
Sulfoxide
Pentamidine Isethionate Concentrations (μM)
Concentrations (μM)
4
2
1
0.5
0.25
0
8
3.7
3.2
2.5
1.2
1.1
1.4
4
2.7
2.7
1.6
1.3
1.2
1.4
2
2.5
1.9
1.7
1.1
1.1
1.2
1
1.8
2.4
1.4
1.0
1.0
1.1
0.5
1.8
1.8
1.6
1.1
0.9
1.2
0
1.9
2.1
1.6
0.9
1.1
1.0
The anti-proliferative effect demonstrated with A459 cells can be similarly demonstrated using other cancer cell lines, such as MCF7 mammary adenocarcinoma, PA-1 ovarian teratocarcinoma, HT29 colorectal adenocarcinoma, H1299 large cell carcinoma, U-2 OS osteogenic sarcoma, U-373 MG glioblastoma, Hep-3B hepatocellular carcinoma, BT-549 mammary carcinoma, T-24 bladder cancer, C-33A cervical carcinoma, HT-3 metastatic cervical carcinoma, SiHa squamous cervical carcinoma, CaSki epidermoid cervical carcinoma, NCI-H292 mucoepidermoid lung carcinoma, NC 1-2030, non small cell lung carcinoma, HeLa, epithelial cervical adenocarcinoma, KB epithelial mouth carcinoma, HT1080 epithelial fibrosarcoma, Saos-2 epithelial osteogenic sarcoma, PC3 epithelial prostate adenocarcinoma, SW480 colorectal carcinoma, CCL-228, and MS-751 epidermoid cervical carcinoma cell lines. Specificity can be tested by using cells such as NHLF lung fibroblasts, NHDF dermal fibroblasts, HMEC mammary epithelial cells, PrEC prostate epithelial cells, HRE renal epithelial cells, NHBE bronchial epithelial cells, CoSmC Colon smooth muscle cells, CoEC colon endothelial cells, NHEK epidermal keratinocytes, and bone marrow cells as control cells.
Other Embodiments
All publications and patents mentioned in the above specification are herein incorporated by reference. Various modifications and variations of the described method and system of the invention will be apparent to those skilled in the art without departing from the scope and spirit of the invention. Although the invention has been described in connection with specific preferred embodiments, it should be understood that the invention as claimed should not be unduly limited to such specific embodiments. Indeed, various modifications of the described modes for carrying out the invention that are obvious to those skilled in molecular biology or related fields are intended to be within the scope of the invention.
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The invention features a method for treating a patient having a cancer or other neoplasm, by administering to the patient (i) a benzimidazole or a metabolite or analog thereof; and (ii) pentamidine or a metabolite or analog thereof simultaneously or within 14 days of each other in amounts sufficient to inhibit the growth of the neoplasm.
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FIELD OF THE INVENTION
This invention generally relates to an energy efficient dry cleaning system that employs supercritical carbon dioxide and that provides improved cleaning with decreased redeposition of contaminants, and reduces damage to polymer substrates.
BACKGROUND OF THE INVENTION
Cleaning contaminants from metal, machinery, precision parts, and textiles (dry cleaning) using hydrocarbon and halogenated solvents has been practiced for many years. Traditional dry cleaning machines operate typically as follows: a soiled garment is placed into a cylindrical "basket" inside a cleaning chamber which is then sealed. A non-polar hydrocarbon solvent is pumped into the chamber. The garment and solvent are mixed together by rotating the basket for the purpose of dissolving the soils and stains from the garment into the solvent, while the solvent is continuously filtered and recirculated in the chamber. After the cleaning cycle, most of the solvent is removed, filtered, and reused.
Recently the environmental, health, and cost risks associated with this practice has become obvious Carbon dioxide holds potential advantages among other non-polar solvents for this type of cleaning. It avoids many of the environmental, health, hazard, and cost problems associated with more common solvents.
Liquid/supercritical fluid carbon dioxide has been suggested as an alternative to halocarbon solvents in removing organic and inorganic contaminants from the surfaces of metal parts and in cleaning fabrics. For example, NASA Technical Brief MFA-29611 entitled "Cleaning With Supercritical CO 1 " (Mar. 1979) discusses removal of oil and carbon tetrachloride residues from metal. In addition, Maffei, U.S. Pat. No. 4,012,194, issued Mar. 15, 1977, describes a dry cleaning system in which chilled liquid carbon dioxide is used to extract soils adhered to garments.
Such methods suggested for cleaning fabrics with a dense gas such as carbon dioxide have tended to be restricted in usefulness because they have been based on standard extraction processes where "clean" dense gas is pumped into a chamber containing the substrate and "dirty" dense gas is drained. This dilution process severely restricts the cleaning efficiency, which is needed for quick processing.
Another problem with attempts to use carbon dioxide in cleaning is the fact that the solvent power of dense carbon dioxide is not high compared to ordinary liquid solvents. Thus, there have been attempts to overcome this solvent limitation.
German Patent Application 3904514, published Aug. 23, 1990, describes a process in which supercritical fluid or fluid mixture, which includes polar cleaning promoters and surfactants, may be practiced for the cleaning or washing of clothing and textiles.
PCT/US89/04674, published Jun. 14, 1990, describes a process for removing two or more contaminants by contacting the contaminated substrate with a dense phase gas where the phase is then shifted between the liquid state and the supercritical state by varying the temperature. The phase shifting is said to provide removal of a variety of contaminants without the necessity of utilizing different solvents.
However, the problems of relatively slow processing, limited solvent power, and redeposition have seriously hindered the usefulness of carbon dioxide cleaning methods.
Another particularly serious obstacle to commercial acceptability of dense gas cleaning is the fact that when certain solid materials, such as polyester buttons on fabrics or polymer parts, are removed from a dense gas treatment they are liable to shatter or to be severely misshapened. This problem of surface blistering and cracking for buttons or other solids has prevented the commercial utilization of carbon dioxide cleaning for consumer clothing and electronic parts.
SUMMARY OF THE INVENTION
Accordingly, it is an object of the present invention to provide a cleaning system in which an environmentally safe non-polar solvent such as densified carbon dioxide can be used for rapid and efficient cleaning, with decreased damage to solid components such as buttons and increased performance.
It is another object of the present invention to provide a cleaning system with reduced redeposition of contaminants, that is adaptable to the incorporation of active cleaning materials that are not necessarily soluble in the non-polar solvent.
Yet another object is to provide a cleaning system that employs a rotatable inner drum designed to hold the substrate during cleaning and a system in which the cleaning fluid is recycled.
In one aspect of the present invention, a system is provided for cleaning contaminated substrates. The system includes a sealable cleaning vessel containing a rotatable drum adapted for holding the substrate, a cleaning fluid storage vessel, and a gas vaporizer vessel for recycling used cleaning fluid. The drum is magnetically coupled to an electric motor so that it can be rotated during the cleaning process.
The inventive system is particularly suited for automation so that the system can be regulated by a microprocessor. Moreover, automation permits increased energy efficiency as the heating and cooling effect associated with CO 2 gas condensation and expansion can be exploited to heat and cool various parts of the system.
BRIEF DESCRIPTION OF THE DRAWINGS
FIG. 1 is a diagrammatic flow sheet showing the system of the invention.
FIG. 2 is a cross-sectional view of the cleaning vessel.
FIG. 3 graphically illustrates temperature and pressure conditions within a hatched area in which cleaning is preferably carried out for reduced button damage.
DESCRIPTION OF THE PREFERRED EMBODIMENT
A cleaning system that can use a substantially non-polar fluid such as densified carbon dioxide (CO 2 ) as the cleaning fluid is shown schematically in FIG. 1. The system generally comprises three vessels, the cleaning vessel 10, preferably a rotatable drum, the gas vaporizer vessel 11, and the storage vessel 12, all of which are interconnected. The cleaning vessel, where soiled substrates (e.g. clothing) are received and placed into contact with the cleaning fluid is also referred to as an autoclave As will be described further below, much of the CO 2 cleaning fluid is recycled in this system.
CO 2 is often stored and/or transported in refrigerated tanks at approximately 300 psi and -18° C. In charging the inventive system with CO 2 , pump 21 is adapted to draw low pressure liquid CO 2 through line 92 that is connected to a refrigerated tank (not shown) through make-up heater 42 which raises the temperature of the CO 2 . The heater preferably has finned coils through which ambient air flows and employs resistive electric heating. Pump 21 is a direct drive, single-piston pump. Liquid CO 2 is then stored in the storage vessel 12 at approximately 915 psi and 25° C. The storage vessel is preferably made of stainless steel. As shown in FIG. 1, conventional temperature gauges (each depicted as an encircled "T"), pressure gauges (each depicted as an encircled "P"), liquid CO 2 level meters (each depicted as an encircled "L"), and a flowmeter (depicted as an encircled "F") are employed in the system. In addition, conventional valves are used.
In operation, after placing soiled substrate into the cleaning vessel, the cleaning vessel is then charged with gaseous CO 2 (from the storage vessel) to an intermediate pressure of approximately 200-300 psi to prevent extreme thermal shock to the chamber. The gaseous CO 2 is transferred into the cleaning vessel through lines 82 and 84. Thereafter, liquid CO 2 is pumped into the cleaning vessel from the storage vessel through lines 80, 91, 81, and 82 by pump 20 which preferably has dual pistons with either direct or hydraulic/electric drive. The pump raises the pressure of the liquid CO 2 to approximately 900 to 1500 psi. Subcooler 30 lowers the temperature of the CO 2 by 2° to 3° below the boiling point to prevent pump cavitation. The temperature of the CO 2 can be adjusted by heating/cooling coils 95 located inside the cleaning vessel. Before or during the cleaning cycle, cleaning additives may be added into the cleaning vessel by pump 23 through lines 82 and 83. Moreover, pump 23 through lines 82 and 83 can also be used to deliver a compressed gas into the cleaning vessel as described below.
Practice of the invention requires contact of a substrate having a contaminant with the first, substantially non-polar fluid that is in a liquid or in a supercritical state. With reference to FIG. 3, when using CO 2 as the first fluid, its temperature can range broadly from slightly below about 20° C. to slightly above about 100° C. as indicated on the horizontal axis and the pressure can range from about 1000 psi to about 5000 psi as shown on the vertical axis. However, within this broad range of temperature and pressure, it has been discovered that there is a zone (represented by the hatched area of the left, or on the convex side, of the curve) where surface blistering to components such as buttons can be reduced, whereas practice outside of the zone tends to lead to button damage that can be quite severe. As is seen by the hatched region of FIG. 3, preferred conditions are between about 900 psi to 2000 psi at temperatures between about 20° C. to about 45° C., with more preferred conditions being pressure from about 900 psi to about 1500 psi at temperatures between about 20° C. and 100° C. or from about 3500 psi to about 5000 psi at temperatures between about 20° C. and 37° C. Where fabrics are being cleaned, one preferably works within a temperature range between about 20° C. to about 100° C. In addition, it has been found within this range that processes which raise the temperature prior to decompression reduce the damage to polymeric parts.
Suitable compounds as the first fluid are either liquid or are in a supercritical state within the temperature and pressure hatched area illustrated by FIG. 3. The particularly preferred first fluid in practicing this invention is carbon dioxide due to its ready availability and environmental safety. The critical temperature of carbon dioxide is 31° C. and the dense (or compressed) gas phase above the critical temperature and near (or above) the critical pressure is often referred to as a "supercritical fluid." Other densified gases known for their supercritical properties, as well as carbon dioxide, may also be employed as the first fluid by themselves or in mixture. These gases include methane, ethane, propane, ammonium-butane, n-pentane, n-hexane, cyclohexane, n-heptane, ethylene, propylene, methanol, ethanol, isopropanol, benzene, toluene, p-xylene, chlorotrifluoromethane, trichlorofluoromethane, perfluoropropane, chlorodifluoromethane, sulfur hexafluoride, and nitrous oxide.
Although the first fluid itself is substantially non-polar, it may include other components, such as a source of hydrogen peroxide and an organic bleach activator therefor, as is described in copending application Ser. No. 754,809, filed Sep. 4, 1991, inventors Mitchell et al., of common assignment herewith. For example, the source of hydrogen peroxide can be selected from hydrogen peroxide or an inorganic peroxide and the organic bleach activator can be a carbonyl ester such as alkanoyloxybenzene. Further, the first fluid may include a cleaning adjunct such as another liquid (e.g., alkanes, alcohols, aldehydes, and the like, particularly mineral oil or petrolatum), as described in Ser. No 715,299, filed Jun. 14, 1991, inventor Mitchell, of common assignment herewith.
In a preferred mode of practicing the present invention, fabrics are initially pretreated before being contacted with the first fluid. Pretreatment may be performed at about ambient pressure and temperature, or at elevated temperature. For example, pretreatment can include contacting a fabric to be cleaned with one or more of water, a surfactant, an organic solvent, and other active cleaning materials such as enzymes. Surprisingly, if these pretreating components are added to the bulk solution of densified carbon dioxide (rather than as a pretreatment), the stain removal process can actually be impeded.
Since water is not very soluble in carbon dioxide, it can adhere to the substrate being cleaned in a dense carbon dioxide atmosphere, and impede the cleaning process. Thus, when a pretreating step includes water, then a step after the first fluid cleaning is preferable where the cleaning fluid is contacted with a hygroscopic fluid, such as glycerol, to eliminate water otherwise absorbed onto fabric.
Prior art cleaning with carbon dioxide has typically involved an extraction type of process where clean, dense gas is pumped into a chamber containing the substrate while "dirty" dense gas is drained This type of continuous extraction restricts the ability to quickly process, and further when pressure in the cleaning chamber is released, then residual soil tends to be redeposited on the substrate and the chamber walls. This problem is avoided by practice of the inventive method (although the present invention can also be adapted for use as continuous extraction process, if desired).
The time during which articles being cleaned are exposed to the first fluid will vary, depending upon the nature of the substrate being cleaned, the degree of soiling, and so forth. However, when working with fabrics, a typical exposure time to the first fluid is between about 1 to 120 minutes, more preferably about 10 to 60 minutes. In addition, the articles being cleaned may be agitated or tumbled in order to increase cleaning efficiency. Of course, for delicate items, such as electronic components, agitation may not be recommended.
In accordance with the invention, the first fluid is replaced with a second fluid that is a compressed gas, such as compressed air or compressed nitrogen. By "compressed" is meant that the second fluid (gas) is in a condition at a lower density than the first fluid but at a pressure above atmospheric. The non-polar first fluid, such as carbon dioxide, is typically and preferably replaced with a non-polar second fluid, such as nitrogen or air. Thus, the first fluid is removed from contact with the substrate and replaced with a second fluid, which is a compressed gas. This removal and replacement preferably is by using the second fluid to displace the first fluid, so that the second fluid is interposed between the substrate and the separate contaminant, which assists in retarding redeposition of the contaminant on the substrate. The second fluid thus can be viewed as a purge gas, and the preferred compressed nitrogen or compressed air is believed to diffuse more slowly than the densified first fluid, such as densified carbon dioxide. The slower diffusion rate is believed useful in avoiding or reducing damage to permeable polymeric materials (such as buttons) that otherwise tends to occur. However, the first fluid could be removed from contact with the substrate, such as by venting, and then the second fluid simply introduced. This alternative is a less preferred manner of practicing the invention.
Most preferably, the second fluid is compressed to a value about equal to P 1 at a temperature T 1 as it displaces the first fluid. This pressure value of about P 1 /T 1 is about equivalent to the pressure and temperature in the chamber as the contaminant separates from the substrate. That is, the value P 1 is preferably the final pressure of the first fluid as it is removed from contact with the substrate. Although the pressure is thus preferably held fairly constant, the molar volume can change significantly when the chamber that has been filled with first fluid is purged with the compressed second fluid.
The time the substrate being cleaned will vary according to various factors when contacting with the first fluid, and so also will the time for contacting with the second fluid vary. In general, when cleaning fabrics, a preferred contacting time will range from 1 to 120 minutes, more preferably from 10 to 60 minutes. Again, the articles being cleaned may be agitated or tumbled while they are in contact with the second fluid to increase efficiency. Preferred values of P 1 /T 1 are about 800 to 5000 psi at 0° C. to 100° C., more preferably about 1000 to 2500 psi at 20° C. to 60° C.
Stained and soiled garments can be pretreated with a formula designed to work in conjunction with CO 2 . This pretreatment may include a bleach and activator and/or the synergistic cleaning adjunct The garments are then placed into the cleaning chamber. As an alternate method, the pretreatment may be sprayed onto the garments after they are placed in the chamber, but prior to the addition of CO 2 .
The chamber is filled with CO 2 and programmed through the appropriate pressure and temperature cleaning pathway. Other cleaning adjuncts can be added during this procedure to improve cleaning. The CO 2 in the cleaning chamber is then placed into contact with a hygroscopic fluid to aid in the removal of water from the fabric. The second fluid (compressed gas) is then pumped into the chamber at the same pressure and temperature as the first fluid. The second fluid displaces the first fluid in this step. Once the first fluid has been flushed, the chamber can then be decompressed and the clean garments can be removed.
In order to recycle most of the CO 2 from the cleaning vessel as it is being replaced by the compressed gas, the CO 2 is drained from the cleaning vessel into the vaporizer vessel 11 which is equipped with an internal heat exchanger 40. The cleaning vessel is drained through lines 87, 89, 91, and 88 by pump 20 thereby recovering gaseous CO 2 at a pressure of approximately 200 psi. During the recovery process, the cleaning vessel is simultaneously heated; unrecovered CO 2 is vented to atmosphere From the vaporizer vessel, CO 2 is continuously repurified by stripping the gaseous CO 2 with activated charcoal in filters 50 and thereafter condensing the clean gaseous CO 2 by condenser 31 so that the recovered CO 2 reenters the storage vessel for later use. Soil, water, additives, and other residues are periodically removed from the vaporizer vessel through valve 66.
Referring to FIG. 2 is a cross-sectional diagrammatic view of a cleaning vessel that is particularly suited for cleaning fabric substrates (e.g., clothing) with supercritical CO 2 . The cleaning vessel comprises an outer chamber 100 having gaseous CO 2 inlet and outlet ports 101 and 102, compressed gas (e.g. air) inlet and outlet ports 103 and 104, and liquid CO 2 inlet and outlet ports 105 and 106. Although the gaseous CO 2 , compressed gas, and liquid CO 2 , each have separate inlet and outlet ports, the cleaning vessel may instead have one port for both inlet and outlet functions for each fluid. Inside the chamber is basket or drum 110 that is supported by two sets of rollers 111 and 111a. The basket has perforations 130 so that gaseous and liquid CO 2 can readily enter and exit the basket. Vanes 112 creates a tumbling action when the drum is spun. Substrates to be cleaned are placed into the basket through an opening in the chamber which is sealed by hinged door 113 when the cleaning vessel is in use. Situated along the perimeter of outer chamber are coils 114 through which coolant or heating fluid can be circulated. The drum in basket 110 is advantageous at exposing greater surface area of fabric substrates to the dense fluid and may also contribute to some mechanical partitioning of soil from fabric. Also, in case there is an interface or density gradient established in the chamber, rotation of the drum can "cycle" the fabrics causing partitioning of soils from fabrics. Additionally, the dense gas can advantageously be separated or driven off from the fabric by the rotational action of the drum.
The basket is magnetically coupled to an motor 120, which is preferably electric, so that the basket can be rotated. Other motive means for driving the basket are possible Specifically, the inner basket is attached to a platform member 121 resting rotatably on ball bearings 122, and drive disk 123. The platform and drive disk are rotationally coupled by magnets 124 which are arranged, in suitable number, symmetrically around the circumference of each. The drive disk is coupled to the motor by belt 125 and pulley 126 or other appropriate means. When the basket is magnetically coupled to a motor, the basket can advantageously be sealed from the external environment with no loss of sealing integrity since drive shafts and other drive means which penetrate the basket are obviated. Thus, by using a magnetic coupling, drive shafts and associated sealing gaskets and the like can be avoided. Further, if the basket is magnetically coupled, the basket can advantageously be easily removed from and replaced in the chamber. In this manner, the basket can be a component unit and, if desired, different loads of fabrics with different laundering requirements can be batched into different baskets and thus loaded individually into the chamber one after another for ease of cleaning. The cleaning vessel is generally made from materials which are chemically compatible with the dense fluids used and sufficiently strong to withstand the pressures necessary to carry out the process, such as stainless steel or aluminum. The cleaning vessel as shown in FIG. 2 can be used as the autoclave 10 in the system as shown in FIG. 1.
It is to be understood that while the invention has been described above in conjunction with preferred specific embodiments, the description and examples are intended to illustrate and not limit the scope of the invention, which is defined by the scope of the appended claims
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A dry cleaning system particularly suited for employing supercritical CO 2 as the cleaning fluid consisting of a sealable cleaning vessel containing a rotatable drum adapted for holding soiled substrate, a cleaning fluid storage vessel, and a gas vaporizer vessel for recycling used cleaning fluid is provided. The drum is magnetically coupled to a motor so that it an be rotated during the cleaning process. The system is adapted for automation which permits increased energy efficiency as the heating and cooling effect associated with CO 2 gas condensation and expansion can be channeled to heat and cool various parts of the system.
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CROSS REFERENCE TO RELATED APPLICATIONS
This is a continuation of a prior U.S. patent application Ser. No. 09/521,420, filed on Mar. 8, 2000, now U.S. Pat. No. 6,230,234, issued on May 8, 2001 and entitled “DIRECT LOGICAL BLOCK ADDRESSING FLASH MEMORY MASS STORAGE ARCHITECTURE”, which is a continuation of U.S. Ser. No. 09/311,045 filed May 13, 1999 now U.S. Pat. No. 6,115,785, issued on Sep. 5, 2000 and entitled “DIRECT LOGICAL BLOCK ADDRESSING FLASH MEMORY MASS STORAGE ARCHITECTURE”, which is a continuation of U.S. Ser. No. 09/087,720 filed May 29, 1998 now prior U.S. Pat. No. 5,924,113 issued on Jul. 13, 1999, entitled “DIRECT LOGICAL BLOCK ADDRESSING FLASH EMORY MASS STORAGE ARCHITECTURE”, which is a continuation of U.S. Ser. No. 08/509,706 filed Jul. 31, 1995 now U.S. Pat. No. 5,845,313, issued on Dec. 1, 1998, entitled “DIRECT LOGICAL BLOCK ADDRESSING FLASH MEMORY MASS STORAGE ARCHITECTURE”.
FIELD OF THE INVENTION
This invention relates to the field of mass storage for computers. More particularly, this invention relates to an architecture for replacing a hard disk with a semiconductor nonvolatile memory and in particular flash memory.
BACKGROUND OF THE INVENTION
Computers conventionally use rotating magnetic media for mass storage of documents, data, programs and information. Though widely used and commonly accepted, such hard disk drives suffer from a variety of deficiencies. Because of the rotation of the disk, there is an inherent latency in extracting information from a hard disk drive.
Other problems are especially dramatic in portable computers. Tin particular, hard disks are unable to withstand many of the kinds of physical shock that a portable computer will likely sustain. Further, the motor for rotating the disk consumes significant amounts of power decreasing the battery life for portable computers.
Solid state memory is an ideal choice for replacing a hard disk drive for mass storage because it can resolve the problems cited above. Potential solutions have been proposed for replacing a hard disk drive with a semiconductor memory. For such a system to be truly useful, the memory must be nonvolatile and alterable. The inventors have determined that FLASH memory is preferred for such a replacement.
FLASH memory is a transistor memory cell which is programmable through hot electron, source injection, or tunneling, and erasable through Fowler-Nordheim tunneling. The programming and erasing of such a memory cell requires current to pass through the dielectric surrounding floating gate electrode. Because of this, such types of memory have a finite number of erase-write cycles. Eventually, the dielectric deteriorates. Manufacturers of FLASH cell devices specify the limit for the number of erase-write cycles between 100.000 and 1.000.000.
One requirement for a semiconductor mass storage device to be successful is that its use in lieu of a rotating media hard disk mass storage device be transparent to the designer and the user of a system using such a device. In other words, the designer or user of a computer incorporating such a semiconductor mass storage device could simply remove the hard disk and replace it with a semiconductor mass storage device. All presently available commercial software should operate on a system employing such a semiconductor mass storage device without the necessity of any modification.
SunDisk proposed an architecture for a semiconductor mass storage using FLASH memory at the Silicon Valley PC Design Conference on Jul. 9, 1991. That mass storage system included read-write block sizes of 512 Bytes to conform with commercial hard disk sector sizes.
Earlier designs incorporated erase-before-write architectures. In this process, in order to update a file on the media, if the physical location on the media was previously programmed, it has to be erased before the new data can be reprogrammed.
This process would have a major deterioration on overall system throughput. When a host writes a new data file to the storage media, it provides a logical block address to the peripheral storage device associated with this data file. The storage device then translates this given logical block address to an actual physical block address on the media and performs the write operation. In magnetic hard disk drives, the new data can be written over the previous old data with no modification to the media. Therefore, once the physical block address is calculated from the given logical block address by the controller, it will simply write the data file into that location. In solid state storage, if the location associated with the calculated physical block address was previously programmed, before this block can be reprogrammed with the new data, it has to be erased. In one previous art, in erase-before-write architecture where the correlation between logical block address given by the host is one to one mapping with physical block address on the media. This method has many deficiencies. First, it introduces a delay in performance due to the erase operation before reprogramming the altered information. In solid state flash, erase is a very slow process.
Secondly, hard disk users typically store two types of information, one is rarely modified and another which is frequently changed. For example, a commercial spread sheet or word processing software program stored on a user's system are rarely, if ever, changed. However, the spread sheet data files or word processing documents are frequently changed. Thus, different sectors of a hard disk typically have dramatically different usage in terms of the number of times the information stored thereon is changed. While this disparity has no impact on a hard disk because of its insensitivity to data changes, in a FLASH memory device, this variance can cause sections of the mass storage to wear out and be unusable significantly sooner than other sections of the mass storage.
In another architecture, the inventors previously proposed a solution to store a table correlating the logical block address to the physical block address. The inventions relating to that solution are disclosed in U.S. Pat. No. 5,388,083, issued on Feb. 7, 1995. U.S. Pat. No. 5,479,638 issued on Dec. 26, 1995.
Those applications are incorporated herein by reference.
The inventors' previous solution discloses two primary algorithms and an associated hardware architecture for a semiconductor mass storage device. It will be understood that “data file” in this patent document refers to any computer file including commercial software, a user program, word processing software document, spread sheet file and the like. The first algorithm in the previous solution provides means for avoiding an erase operation when writing a modified data file back onto the mass storage device. Instead, no erase is performed and the modified data file is written onto an empty portion of the mass storage.
The semiconductor mass storage architecture has blocks sized to conform with commercial hard disk sector sizes. The blocks arc individually erasable. In one embodiment, the semiconductor mass storage can be substituted for a rotating hard disk with no impact to the user, so that such a substitution will be transparent. Means are provided for avoiding the erase-before-write cycle each time information stored in the mass storage is changed.
According to the first algorithm, erase cycles are avoided by programming an altered data file into an empty block. This would ordinarily not be possible when using conventional mass storage because the central processor and commercial software available in conventional computer systems are not configured to track continually changing physical locations of data files. The previous solution includes a programmable map to maintain a correlation between the logical address and the physical address of the updated information files.
All the flags, and the table correlating the logical block address to the physical block address are maintained within an array of CAM cells. The use of the CAM cells provides very rapid determination of the physical address desired within the mass storage, generally within one or two clock cycles. Unfortunately, as is well known, CAM cells require multiple transistors, typically six. Accordingly, an integrated circuit built for a particular size memory using CAM storage for the tables and flags will need to be significantly larger than a circuit using other means for just storing the memory.
The inventors proposed another solution to this problem which is disclosed in U.S. Pat. No. 5,485,595, issued on Jan. 16, 1996. That application is incorporated herein by reference.
This additional previous solution invented by these same inventors is also for a nonvolatile memory' storage device. The device is also configured to avoid having to perform an erase-before-write each time a data file is changed by keeping a correlation between logical block address and physical block address in a volatile space management RAM. Further, this invention avoids the overhead associated with CAM cell approaches which require additional circuitry.
Like the solutions disclosed above by these same inventors, the device includes circuitry for performing the two primary algorithms and an associated hardware architecture for a semiconductor mass storage device. In addition, the CAM cell is avoided in this previous solution by using RAM cells.
Reading is performed in this previous solutions by providing the logical block address to the memory storage. The system sequentially compares the stored logical block addresses until it finds a match. That data file is then coupled to the digital system. Accordingly, the performance offered by this solution suffers because potentially all of the memory locations must be searched and compared to the desired logical block address before the physical location of the desired information can be determined.
What is needed is a semiconductor hard disk architecture which provides rapid access to stored data without the excessive overhead of CAM cell storage.
SUMMARY OF THE INVENTION
The present invention is for a nonvolatile memory storage device. The device is configured to avoid having to perform an erase-before-write each time a data file is changed. Further, to avoid the overhead associated with CAM cells, this approach utilizes a RAM array. The host system maintains organization of the mass storage data by using a logical block address. The RAM array is arranged to be addressable by the same address as the logical block addresses of the host. Each such addressable location in the RAM includes a field which holds the physical address of the data in the nonvolatile mass storage expected by he host. This physical block address information must be shadowed in the nonvolatile memory to ensure that the device will still function after resuming operation after a power down because Rams are volatile memory devices. In addition, status flags are also stored for each physical location. The status flags can be stored in either the nonvolatile media or in both the RAM and in the nonvolatile media.
The device includes circuitry for performing two primary algorithms and an associated hardware architecture for a semiconductor mass storage device. The first algorithm provides a means for mapping of host logical block address to physical block address with much improved performance and minimal hardware assists. In addition, the second algorithm provides means for avoiding an erase-before-write cycle when writing a modified data file back onto the mass storage device. Instead, no era-se is performed and the modified data file is written onto an empty portion of the mass storage.
Reading is performed in the present invention by providing the logical block address to the memory storage. The RAM array is arranged so that the logical block address selects one RAM location. That location contains the physical block address of the data requested by the host or other external system. That data file is then read out to the host.
According to the second algorithm, erase cycles are avoided by programming an altered data file into an empty mass storage block rather than itself after an erase cycle of the block as done on previous arts.
BRIEF DESCRIPTION OF THE DRAWINGS
FIG. 1 shows a schematic block diagram of an architecture for a semiconductor mass storage according to the present invention.
FIG. 2 shows an alternative embodiment to the physical block address 102 of the RAM storage of FIG. 1 .
FIG. 3 shows a block diagram of a system incorporating the mass storage device of the present invention.
FIGS. 4 through 8 show the status of several of the flags and information for achieving the advantages of the present invention.
FIG. 9 shows a flow chart block diagram of the first algorithm according to the present invention.
DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENT
FIG. 1 shows an architecture for implementation of a solid state storage media according to the present invention. The storage media is for use with a host or other external digital system. The mass storage is partitioned into two portions, a volatile RAM array 100 and a nonvolatile array 104 . According to the preferred embodiment, all of the nonvolatile memory storage is FLASH. The FLASH may be replaced by EEPROM. The RAM can be of any convenient type.
The memory storage 104 is arranged into N blocks of data from zero through N-1. Each of the blocks of data is M Bytes long. In the preferred embodiment, each data block is 512 Bytes long to correspond with a sector length in a commercially available hard disk drive plus the extra numbers of bytes to store the flags and logical block address information and the associated ECC. The memory 104 can contain as much memory storage as a user desires. An example of a mass storage device might include 100 M Byte of addressable storage. There are a plurality of RAM locations 102 . Each RAM location 102 is uniquely addressable by controller using an appropriate one of the logical block addresses provided by the host system or the actual physical address of the nonvolatile media. The RAM location 102 contains the physical block address of the data associated with the logical block address and the flags associated with a physical block address on the nonvolatile media.
It is possible that the physical block address can be split into two fields as shown in FIG. 2 . These fields can be used for cluster addresses of a group of data blocks. The first such field 290 is used to select a cluster address and the second such field 292 can be used to select the start address of the logical block address associated with this cluster.
A collection of information flags is also stored for each nonvolatile memory location 106 . These flags include an old/new flag 110 , a used/free flag 112 , a defect flag, 114 , and a single/sector flag 116 . Additionally, there is also a data store 122 .
When writing data to the mass storage device of the present invention, a controller determines the first available physical block for storing the data. The RAM location 102 corresponding to the logical block address selected by the host is written with the physical block address where the data is actually stored within the nonvolatile memory array in 104 (FIG. 1 ).
Assume for example that a user is preparing a word processing document and instructs the computer to save the document. The document will be stored in the mass storage system. The host system will assign it a logical block address. The mass storage system of the present invention will select a physical address of an unused block or blocks in the mass storage for storing the document. The address of the physical block address will be stored into the RAM location 102 corresponding to the logical block address. As the data is programmed, the system of the present invention also Sets the used/free flag 112 in 104 and 293 to indicate that this block location is used. One used/free flag 112 is provided for each entry of the nonvolatile array 104 .
Later, assume the user retrieves the document, makes a change and again instructs the computer to store the document. To avoid an erase-before-write cycle, the system of the present invention provides means for locating a block having its used/free flag 112 in 100 unset (not programmed) which indicates that the associated block is erased. The system then sets the used/free flag for the new block 112 of 106 and 293 of 100 and then stores the modified document in that new physical block location 106 in the nonvolatile array 104 . The address of the new physical block location is also stored into the RAM location 102 corresponding the logical block address, thereby writing over the previous physical block location in 102 . Next, the system sets the old/new flag 110 of the previous version of the document indicating that this is an old unneeded version of the document in 110 of 104 and 293 of 100 In this way, the system of the present invention avoids the overhead of an erase cycle which is required in the erase-before-write of conventional systems to store a modified version of a previous document.
Because of RAM array 100 will lose its memory upon a power down condition, the logical block address with the active physical block address in the media is also stored as a shadow memory 108 in the nonvolatile array 104 . It will be understood the shadow information will be stored into the appropriate RAM locations 102 by the controller. During power up sequence, the RAM locations in 100 are appropriately updated from every physical locations in 104 , by reading the information 106 of 104 . The logical address 108 of 106 is used to address the RAM location of 100 to update the actual physical block address associated with the given logical block address. Also since 106 is the actual physical block address associated with the new data 122 , the flags 110 , 112 , 114 , and 116 are updated in 293 of 102 with the physical block address of 106 in 100 . It will be apparent to one of ordinary skill in the art that the flags can be stored in either the appropriate nonvolatile memory location 106 or in both the nonvolatile memory location and also in the RAM location 102 associated with the physical block address.
During power up, in order to assign the most recent physical block address assigned to a logical block address in the volatile memory 100 , the controller will first reads the Flags 110 , 112 , 114 , and 116 portion of the nonvolatile memory 104 and updates the flags portion 293 in the volatile memory 100 . Then it reads the logical block address 108 of every physical block address of the nonvolatile media 104 and by tracking the flags of the given physical block address in the volatile memory 100 , and the read logical block address of the physical block address in the nonvolatile memory 104 , it can update the most recent physical block address assigned to the read logical block address in the volatile memory 100 .
FIG. 3 shows a block diagram of a system incorporating the mass storage device of the present invention. An external digital system 300 such as a host computer, personal computer and the like is coupled to the mass storage device 302 of the present invention. A logical block address is coupled via an address bus 306 to the volatile RAM array 100 and to a controller circuit 30 t Control signals are also coupled to the controller 304 via a control bus 308 . The volatile RAM array 100 is coupled via data paths 140 for providing the physical block address to the nonvolatile RAM array 104 . The controller 304 is coupled to control both the volatile RAM 100 , the nonvolatile array 104 , and for the generation of all flags.
A simplified example, showing the operation of the write operation according to the present invention is shown in FIGS. 4 through 8 . Not all the information flags are shown to avoid obscuring these features of the invention in excessive detail. The data entries are shown using decimal numbers to further simplify the understanding of the invention. It will be apparent to one of ordinary skill in the art that in a preferred embodiment binary counting will be used.
FIG. 4 shows an eleven entry mass storage device according to the present invention. There is no valid nor usable data stored in the mass storage device of FIG. 4 . Accordingly, all the physical block addresses are empty. The data stored in the nonvolatile mass storage location ‘6’ is filled and old. Additionally, location ‘9’ is defective and cannot be used.
The host directs the mass storage device of the example to write data pursuant to the logical block address ‘3’ and then to ‘4’ The mass storage device will first write the data associated with the logical block address ‘3’. The device determines which is the first unused location in the nonvolatile memory. In this example, the first empty location is location ‘0’. Accordingly, FIG. 5 shows that for the logical block address ‘3’, the corresponding physical block address ‘0’ is stored and the used flag is set in physical block address ‘0’. The next empty location is location ‘1’. FIG. 6 shows that for the logical block address ‘4’, the corresponding physical block address ‘1’ is stored and the used flag is set in physical block address ‘1’.
The host instructs that something is to be written to logical block address ‘3’ again. The next empty location is determined to be location ‘2’. FIG. 7 shows that the old flag in location ‘0’ is set to indicate that this data is no longer usable, the used flag is set in location ‘2’ and the physical block address in location ‘3’ is changed to ‘2’.
Next, the host instructs that something is to be written to logical block address ‘4’ again. The next empty location is determined to be location ‘3’. FIG. 8 shows that the old flag in location ‘1’ is set to indicate that this data is no longer usable, the used flag is set in location ‘3’ and the physical block address in location ‘4’ is changed to ‘3’. (Recall that there is generally no relation between the physical block address and the data stored in the same location.)
FIG. 9 shows algorithm 1 according to the present invention. When the system of the present invention receives an instruction to program data into the mass storage (step 200 ), then the system attempts to locate a free block (step 202 ), i.e., a block having an unset (not programmed) used/free flag. If successful, the system sets the used/free flag for that block and programs the data into that block (step 206 ).
If on the other hand, the system is unable to locate a block having an unset used/free flag, the system erases the flags (used/free and old/new) and data for all blocks having a set old/new flag and unset defect flag (step 204 ) and then searches for a block having an unset used/free flag (step 202 ). Such a block has just been formed by step 204 . The system then sets the used/flag for that block and programs the data file into that block(step 206 ).
If the data is a modified version of a previously existing file, the system must prevent the superseded version from being accessed. The system determines whether the data file supersedes a previous data file (step 208 ). If so, the system sets the old/new flag associated with the superseded block (step 210 ). If on the other hand, the data file to be stored is a newly created data file, the step of setting the old/new flag (step 210 ) is skipped because there is no superseded block. Lastly, the map for correlating the logical address 108 to the physical address 130 is updated (step 2 t 2 i
By Following the procedure outlined above, the overhead associated with an erase cycle is avoided for each write to the memory 104 except for periodically This vastly improves the performance of the overall computer system employing the architecture of the present invention.
In the preferred embodiment of the present invention, the programming of the flash memory follows the procedure commonly understood by those of ordinary skill in the art. In other words, the program impulses are appropriately applied to the bits to be programmed and then compared to the data being programmed to ensure that proper programming has occurred. In the event that a bit fails to be erased or programmed properly, a defect flag 114 (in FIG. 1 ) is set which prevent that block from being used again.
The present invention is described relative to a preferred embodiment. Modifications or improvements which apparent to one of ordinary skill in the art after reading this disclosure are deemed within the spirit and scope of this invention.
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A nonvolatile semiconductor mass storage system and architecture can be substituted for a rotating hard disk. The system and architecture avoid an erase cycle each time information stored in the mass storage is changed. Erase cycles are avoided by programming an altered data file into an empty mass storage block rather than over itself as a hard disk would. Periodically, the mass storage will need to be cleaned up. These advantages are achieved through the use of several flags, and a map to correlate a logical block address of a block to a physical address of that block. In particular, flags are provided for defective blocks, used blocks, and old versions of a block. An array of volatile memory is addressable according to the logical address and stores the physical address.
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BACKGROUND OF THE INVENTION
1. Field of the Invention
The present invention generally relates to liquid crystal display devices and, more particularly, to a liquid crystal display device equipped with a backlight device that illuminates a liquid display part.
2. Description of the Related Art
First, a description will be given, with reference to FIG. 1 , of a conventional liquid crystal display device. FIG. 1 is an exploded perspective view of a conventional liquid crystal display device.
A liquid crystal panel 1 of the liquid crystal display device, which displays information thereon, is accommodated in a housing 2 that also serves as a decorative board. A backlight device is provided under the liquid crystal panel 1 so as to make the liquid crystal display legible by illuminating from backside.
The backlight device has light sources 3 , a light-guiding plate 4 and optical sheets 5 a and 5 b . The light sources 3 , the light-guiding plate 4 and the optical sheets 5 a and 5 b are accommodated in a backlight housing comprising upper and lower housings 6 a and 6 b.
A light emitted from each of the light sources 3 propagates inside the light-guiding plate 4 , and exits from a front surface of the light-guiding plate 4 toward the liquid crystal panel 1 . A reflective panel 7 is provided on a side of the light-guiding plate 4 opposite to the light-guiding plate 4 , and the light projected from each of the light sources 3 and incident on the light-guiding plate 4 exits only in a direction toward the liquid crystal panel 1 .
The light that exits from the light-guiding plate 4 is irradiated onto the liquid crystal panel 1 after being subjected to a predetermined optical process such as diffusion or convergence by the optical sheets 5 a and 5 b . Thereby, the background of the liquid crystal panel 1 becomes bright moderately, which makes the display on the liquid crystal panel 1 legible.
Although the two optical sheets 5 a and 5 b are used in the device shown in FIG. 1 , a single optical sheet may be used if a desired backlight effect can be obtained, or there may be a case where more than three optical sheets are used. Additionally, although the two light sources 3 are provided on opposite sides of the light-guiding plate 4 in FIG. 1 , only one light source may be provided on one side.
In the structure of the backlight device shown in FIG. 1 , each of the optical sheets 5 a and 5 b has the front surface and the back surface, and does not function correctly if it is mistakenly incorporated in a wrong direction. Therefore, it is necessary to check, after assembling the backlight device, whether the optical sheets 5 a and 5 b have been incorporated and whether their front and back surfaces face correctly.
However, after assembling the backlight device, the optical sheets 5 a and 5 b are covered by the liquid crystal panel 1 and the backlight housing 6 a . Therefore, there is a problem in that it is difficult to check visually from outside, after the assembly of the backlight device, whether the optical sheets 5 a and 5 b are appropriately incorporated.
Here, if an ambient temperature of the liquid crystal display device is raised in an environmental test etc., the optical sheets 5 a and 5 b will expand thermally. Under such circumstances, there is a case in which a periphery of each of the optical sheets 5 a and 5 b shifts toward the center thereof without extending outwardly. In such a case, each of the optical sheets 5 a and 5 b deforms into a fine-wavy form as shown in FIG. 2 B.
That is, if the gap between the backlight housing 6 b and the light-guiding plate 4 is large, each of the optical sheets 5 a and 5 b makes a smooth deformation in which a center section protrudes as shown in FIG. 2 A. However, if the gap is small as shown in FIG. 2B , each of the optical sheets 5 a and 5 b will deform into the wavy form having many fine waves. If the optical sheets 5 a and 5 b deform as shown in FIG. 2B , there is a problem in that a light passing through the optical sheets 5 a and 5 b is influenced and unevenness occurs in the backlight illumination.
Moreover, although a light-guiding plate 4 also expands in connection with the temperature rise, the light-guiding plate 4 deforms so that the center portion thereof is bent since the periphery thereof is fixed and the thickness thereof is larger than the thickness of the optical sheet and the light-guiding plate 4 has rigidity. Here, when the center portion of the light-guiding plate 4 bends in a direction to separate from the liquid crystal panel 1 , the gap between the liquid crystal panel 1 (the upper backlight housing 6 b ) and the light-guiding plate 4 expands only in the center portion. Therefore, the space within which the optical sheets 5 a and 5 b can deform is expanded, and there is a problem in that a magnitude of deformation further increases.
Each of the light sources 3 shown in FIG. 1 consists of a fluorescence tube, which generally uses an ultraviolet radiation of mercury. FIG. 3 is a perspective view of the light source 3 that consists of a fluorescence tube. In the light source 3 , opposite ends of a fluorescence tube 3 a is attached to fluorescence tube support members 3 b , and a reflector 3 c is provided around the fluorescence tube 3 a . The reflector 3 c has a function to reflect a light emitted from the fluorescence tube 3 a and converge the reflected light onto an incident light end surface of the light-guiding plate 4 . The fluorescence tube 3 a also emits heat when emitting a light. Such a heat is released through the reflector 3 c and the fluorescence tube support members 3 b.
As mentioned above, since an ultraviolet radiation of mercury is used for the fluorescence tubing 3 c , mercury vapor is enclosed within a glass tube, which constitutes the luminescence portion. Here, if a wall-surface temperature of the glass tube changes, a mercury vapor pressure inside the glass tube changes, which results in a change in the luminous efficiency. Such a change in the luminous efficiency takes a peak value (maximum) at a certain temperature if the glass wall surface. Therefore, in order to maintain a high luminous efficiency, it is necessary to maintain the wall surface of glass tube at a constant temperature.
Moreover, a cold cathode tube can also be used for the fluorescence tube. In such a case, when a cold cathode tube emits electrons, much electric power (=cathode drop voltage×tube current) near the cathode. Such an electric power is reflected to as a reactive power, and most parts of the reactive power are converted into heat. If the liquid crystal display device is enlarged and the intensity of luminescence of the backlight is raised, a cathode drop electrical potential difference and a tube current, which are the main components of a tubing electrical potential difference, will go up inevitably. Consequently, generation of heat of the fluorescence tube end section, which is the cathode section, will become larger relative to other part.
As mentioned above, generation of heat of the fluorescence tube-end portion, which is the cathode section, increases, the temperature near the fluorescence tube-end portion rises and creep may occur in a solder connecting a terminal and a lead wire. If creep occurs in a solder, it causes a poor connection, and there is a problem in that a reliability of dependability of a connection falls remarkably. Generally, a creep phenomenon starts to occur at 0.5 times the melting point of the material. Usually, since the melting point of a solder is 183° C., a half of the melting point is 91.5° C. It is appreciated from the experiments that if the temperature of the solder exceeds 100° C., the creep appears remarkably.
Moreover, when the temperature near the fluorescence tube-end portion rises, there is a problem in that heat deformation and thermal degradation occur in a resin member such as the light-guiding plate 4 or a plastic frame, which are members arranged around the fluorescence tube. In order to solve the problem caused by the generation of heat in such a fluorescence tube and to maintain the luminous efficiency at a high value, it is necessary to properly control a heat radiation from the fluorescence tube.
However, in the structure of the conventional light source 3 , a heat is radiated from only the by reflector 3 c which merely encloses the fluorescence tube 3 a and the fluorescence tube support member, and the temperature control of the fluorescence tube and a peripheral portion thereof according to the heat radiation is not taken into consideration. Therefore, there is a problem in that the luminous efficiency of the fluorescence tube cannot be maintained in a good state.
SUMMARY OF THE INVENTION
It is a general object of the present invention to provide an improved and useful liquid crystal display device in which the above-mentioned problems are eliminated.
A more specific object of the present invention is to provide a liquid crystal display device having a backlight device including an optical sheet of which existence can be visually recognized from outside.
Another object of the present invention is to provide a liquid crystal display device having a backlight device including an optical sheet that is prevented from deformation due to thermal expansion.
A further object of the present invention is to provide a liquid crystal display device having a backlight device that can eliminate a problem caused by a heat of a light source.
In order to achieve the above-mentioned objects, there is provided according to one aspect of the present invention a liquid crystal display device irradiating a light of a light source from a backside of a liquid crystal panel, the liquid crystal display device comprising: the liquid crystal panel; a light-guiding plate provided under the liquid crystal panel for guiding the light of the light source to the liquid crystal panel by transmitting the light therethrough; at least one optical sheet arranged between the liquid crystal panel and the light-guiding plate; and a backlight housing accommodating the light-guiding plate and the optical sheet, wherein the optical sheet has a protruding part extending outwardly from a periphery thereof, and the backlight housing has an opening at a position corresponding to the protruding part.
According to the above-mentioned invention, present, the opening provided in the backlight housing serves as a housing window through which the protruding part of the optical sheet can be visually recognized after the liquid crystal display device is assembled. Thus, a defect in the liquid crystal display device, such as a fact that the optical sheet are forgotten to insert during an assembling operation, can be easily checked.
In the liquid crystal display device according to the present invention, a plurality of the optical sheets may be provided, and the protruding parts of the optical sheets may be located at different positions from each other. Accordingly, the protruding parts do not overlap with each other, and presence of all optical sheets can be checked visually. The protruding part may be provided at a position other than positions along a center line of the optical sheet. Accordingly, if the optical sheet is placed upside down, the protruding part cannot be aligned with the window of the housing. Thus, the fact that the optical sheet is assembled upside down can be checked visually.
Additionally, there is provided according to another aspect of the present invention a liquid crystal display device irradiating a light of a light source from a backside of a liquid crystal panel, the liquid crystal display device comprising: the liquid crystal panel; a light-guiding plate provided under the liquid crystal panel for guiding the light of the light source to the liquid crystal panel by transmitting the light therethrough; at least one optical sheet arranged between the liquid crystal panel and the light-guiding plate; and a backlight housing accommodating the light-guiding plate and the optical sheet, wherein the optical sheet is located within a gap formed between the backlight housing and the light-guiding plate, and a width of the gap at the center of the optical sheet is smaller than a width of the gap at an end of the optical sheet.
According to the above-mentioned invention, when the optical sheet expands thermally, the deformation of the optical sheet does not concentrate into the center portion since there is no space in which the deformation occurs. Thus, the optical sheet deforms along a relatively gentle curve, which prevents uneven illumination by the light passing through the optical sheet.
In the liquid crystal display device according to the above-mentioned invention, the backlight housing may have a protruding part formed in the middle of a surface facing the light-guiding plate, and a width of the gap at the center of the optical sheet may be equal to a distance between the protruding part and the light-guiding plate. Accordingly, dimensions of the space in which the optical sheet is placed can be easily set by forming the protruding part on the backlight housing. The protruding part may have a length equal to one fourth of a length of the optical sheet. Accordingly, the optical sheet tends to deform along the protruding part, which prevents generation of small waveform deformation in the optical sheet.
Additionally, there is provided according another aspect of the present invention a liquid crystal display device using a light of a light source as a backlight, the liquid crystal display device comprising: a liquid crystal panel; and a light-guiding plate provided under the liquid crystal panel for guiding the light of the light source to the liquid crystal panel by transmitting the light therethrough, wherein the light source includes a fluorescent tube and a reflector surrounding the fluorescent tube, and a configuration of a portion of the reflector surrounding a luminescence section of the fluorescent tube is different from a configuration of has a portion of the reflector surrounding an electrode section of the fluorescent tube.
According to the above-mentioned invention, different heat release characteristics can be provided to the portion of the reflector surrounding the luminescence section of the fluorescent tube and the portion of the reflector surrounding the electrode section of the fluorescent tube. Accordingly, the temperature of the fluorescent tube can be accurately adjusted, and the luminescence characteristic of the luminescent tube can be maintained at a high level.
In the liquid crystal display device according to the above-mentioned invention, a step part may be formed between the portion of the reflector surrounding the luminescence section of the fluorescent tube and the portion of the reflector surrounding the electrode section of the fluorescent tube, and a distance between the electrode section of the fluorescent tube and the reflector may be smaller than a distance between the luminescence section of the fluorescent tube and the reflector. Accordingly, an amount of heat released form the electrode section of the fluorescent tube can be larger than an amount of heat released from the luminescence section, which results in decrease in the temperature of the electrode section. Thus, the solder connecting part provided in the electrode section can be prevented from being affected by a high temperature.
In the liquid crystal display device according to the above-mentioned invention, the electrode section of the fluorescent tube may preferably be connected to a fluorescent tube support part having a heat conductivity equal to or greater than 0.5 [W/(m·K)]. The reflector may be made of a metal or a material having a heat conductivity substantially equal to a heat conductivity of a metal. Accordingly, an amount of heat released from the reflector is increased, which results in decrease in the temperature of the fluorescent tube.
Other objects, features and advantages of the present invention will become more apparent from the following detailed description when read in conjunction with the accompanying drawings.
BRIEF DESCRIPTION OF DRAWINGS
FIG. 1 is an exploded view of a conventional liquid crystal display device;
FIGS. 2A and 2B are illustrations of an optical sheet for explaining a mode of deformation;
FIG. 3 is a perspective view of a light source comprising fluorescence tubes;
FIG. 4A is an exploded perspective view of a liquid crystal display device according to a first embodiment of the present invention;
FIG. 4B is an exploded view of a part of a backlight housing shown in FIG. 4A ;
FIG. 5 is a cross-sectional view of a liquid crystal display device according to a second embodiment of the present invention;
FIG. 6 is an enlarged view of a part indicated by a dotted circle A of FIG. 5 ;
FIG. 7 is an enlarged view of a part indicated by a doted circle B of FIG. 5 ;
FIG. 8 is an illustration showing a protruding part;
FIG. 9 is a cross-sectional view of a liquid crystal display device according to a variation of the liquid crystal display device shown in FIG. 5 ;
FIG. 10 is a cross-sectional view of a liquid crystal display device according to another variation of the liquid crystal display device shown in FIG. 5 ;
FIG. 11 is a perspective view of a light source provided in a liquid crystal display device according to a third embodiment of the present invention;
FIG. 12 is a perspective view of the light source shown in FIG. 11 ;
FIG. 13 is a cross-sectional view of a part corresponding to a periphery of a glass tube heat-emitting section of a reflector;
FIG. 14 is a cross-sectional view of a part corresponding to a periphery of a fluorescent tube support member of the reflector; and
FIG. 15 is a cross-sectional view of the reflector.
DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS
A description will now be given, with reference to FIGS. 4A and 4B , of a first embodiment of the present invention. FIG. 4A is an exploded perspective view of a liquid crystal display device according to the first embodiment of the present invention. FIG. 4B is a plan view of a part of a backlight housing shown in FIG. 4 A. In FIGS. 4A and 4B , parts that are the same as the parts shown in FIG. 1 are given the same reference numerals, and descriptions thereof will be omitted.
Although the liquid crystal display device according to the first embodiment of the present invention has the same basic structure as the liquid crystal display device shown in FIG. 1 , a configuration of optical sheets and a lower backlight housing are different. That is, in the backlight device of the liquid crystal display device according to the present embodiment, as shown in FIG. 4A , optical sheets 10 a and 10 b is provided with protruding parts 10 a - 1 and 10 b - 1 , respectively, and the lower backlight housing 12 is provided with a housing aperture 12 a.
A housing 2 as a decorative panel is formed in the shape of a box by a metal plate, such as a stainless steel plate, an iron plate or an aluminum plate, and has a function to reinforce a liquid crystal panel 1 accommodated in the housing 2 . The optical sheets 10 a and 10 b are provided under the liquid crystal panel 1 , and a light-guiding plate 4 is provided under the optical sheets 10 a and 10 b . The light-guiding plate 4 is formed of a highly transparent resin such as acrylic resin, and has a function to lead a light from a light source 3 to the liquid crystal panel 1 . The optical sheets 10 a and 10 b are thin sheets which apply optical processing such as divergence or convergence to the light led to the liquid crystal panel 1 .
The light source 3 , which consists of a fluorescence tube, is arranged on each side of the light-guiding plate 4 so as to project a light toward a light incidence end surface of the light-guiding plate 4 . The light emitted from the light source 3 in a direction opposite to the liquid crystal panel 1 is reflected by a reflecting plate 7 . Thereby, the great portion of the light incident on the light-guiding plate 4 exits toward the liquid crystal panel 1 .
The optical sheets 10 a and 10 b , the light-guiding plate 4 , the reflecting plate 7 and the light source 3 are accommodated between an upper backlight housing 6 a and a lower backlight housing 12 , thereby constituting a backlight device. The upper backlight housing 6 a and the lower backlight housing 12 are formed as a resin mold component such as polycarbonate, or formed of a metal plate such as a stainless steel plate, an iron plate or an aluminum plate. The backlight device is attached to a housing 2 so as to be located under the liquid crystal panel 1 .
The optical sheets 10 a and 10 b provided with the protruding parts 10 a - 1 and 10 b - 1 are arranged, when assembled as a backlight device, in a position corresponding to a housing aperture 12 a of the backlight housing 12 . That is, the housing aperture 12 a is an opening provided in the backlight housing 12 , and is configured so that the protruding parts 10 a - 1 and 10 b - 1 can be visually recognized from outside through the housing aperture 12 a . Therefore, it can be inspected whether the optical sheets 10 a and 10 b are incorporated by checking whether the protruding parts 10 a - 1 and 10 b - 1 exist in the housing aperture 12 a after the assembly of the liquid crystal display device.
In the above-mentioned structure, although the two optical sheets 10 a and 10 b are provided, if the protruding parts 10 a - 1 and 10 b - 1 are located in a completely overlapping position, the protruding part 10 a - 1 is covered by the protruding part 10 b - 1 , which causes difficulty in the visual check of the optical sheets. In such a case, existence of the two optical sheets 10 a and 10 b can be easily checked by providing the protruding parts 10 a - 1 and 10 b - 1 in different positions so as to not overlap with each other. Thereby, when the liquid crystal display device is assembled without incorporating both or one of the optical sheets 10 a and 10 b , it can be easily recognized by a visual inspection, and the quality of the liquid crystal display device is prevented from falling due to both or one of the optical sheets not having been incorporated.
Moreover, it can also be checked easily whether or not the optical sheets 10 a and 10 b are incorporated with the front and back surfaces in a proper state by providing the protruding parts 10 a - 1 and 10 b - 1 in an asymmetrical position with respect to a center line of the optical sheets 10 a and 10 b . That is, by providing the protruding parts 10 a - 1 and 10 b - 1 in the asymmetrical position which is offset from the center line of the optical sheets 10 a and 10 b , when the optical sheets 10 a - 1 and 10 b - 1 are incorporated upside down, the position of the protruding parts 10 a - 1 and 10 b - 1 is on the opposite side with respect to the center line, which causes the protruding parts 10 a - 1 and 10 b - 1 disappear from the housing aperture 12 a . Therefore, it can be easily checked by a visual inspection whether or not the optical sheets 10 a and 10 b are assembled with the front and back surfaces being correctly positioned, and the quality of the liquid crystal display device is prevented from falling due to the optical sheets 10 a and 10 b having been incorporated with upside down.
A description will now be given, with reference to FIG. 5 , of a second embodiment of the present invention. FIG. 5 is a cross-sectional view of the liquid crystal display device by the second embodiment of the present invention. In FIG. 5 , parts that are the same as the parts shown in FIG. 4 are given the same reference numerals, and descriptions thereof will be omitted.
As shown in FIG. 5 , the liquid crystal display device according to the present embodiment has the same structure as the liquid crystal display device shown in FIG. 4 except for the difference regarding the configuration of an upper backlight housing 20 . That is, the upper backlight housing 20 shown in FIG. 5 is constituted by a resin frame, and a protruding part 20 a is formed on a surface of the housing 20 which faces the optical sheet 10 a . The protruding part 20 a is formed in a center portion of the backlight housing 20 in FIG. 5 , and is formed so as to protrude toward the optical sheet 10 a . For example, if a total thickness of the two optical sheets 10 a and 10 b is 0.58 mm, a distance between the center portion of the protruding part 20 a and the light-guiding plates 4 is set to be 0.6 mm, while a distance between the backlight housing 20 and the light-guiding plate 4 is set to be 0.7 mm in portions other than the protruding part 20 a . Here, the distance between the center portion of the protruding part 20 a and the light-guiding plates 4 and the distance between the backlight housing 20 and the light-guiding plate 4 correspond to gaps in which the optical sheets 10 a and 10 b are arranged.
FIG. 6 is an enlarged view of a part indicated by a dotted circle A of FIG. 5 , and FIG. 7 is an enlarged view of a part indicated by a doted circle B of FIG. 5 . As shown in FIG. 6 , the protruding part 20 a of the center portion of the upper backlight housing 20 formed by a resin frame is arranged in a state where there is almost no gap between the protruding part 20 a and the optical sheets 10 a and 10 b arranged on the light-guiding plate 4 . On the other hand, as shown in FIG. 7 , in the end part of the optical sheet, a predetermined gap is formed between the back surface of the backlight housing 20 and the optical sheet 10 a.
FIG. 8 is an illustration showing the configuration of the protruding part 20 a . As shown in FIG. 8 , the protruding part 20 a is formed in a round shape such as, for example, an arc of a large radius. It is preferable that the length of a part in which the protruding part 20 a is formed is about ¼ of the length of the optical sheet.
In the above structure, when the optical sheet expands thermally, there is no space in which a bent portion is formed since the center portion is provided with the protruding part 20 a . For this reason, generation of bending will be concentrated and toward the end of the optical sheet.
Here, since the protruding part 20 a is formed with a smooth roundness, the optical sheet will bend in accordance with the configuration of the protruding part 20 a , and bending of fine waves as shown in FIG. 2B hardly occurs. Therefore, generation of unevenness in the brightness due to fine waves of the optical sheet can be prevented.
FIG. 9 is a cross-sectional view of a liquid crystal display device, which is a variation of the liquid crystal display device shown in FIG. 5 . In the liquid crystal display device shown in FIG. 9 , the light source 3 is provided on only one side of the light-guiding plate 4 . The backlight housing 20 is provided with the protruding part 20 a similar to the liquid crystal display device shown in FIG. 5 .
FIG. 10 is a cross-sectional view of a liquid crystal display device, which is another variation of the liquid crystal display device shown in FIG. 5 . The liquid crystal display device shown in FIG. 10 has a smoothly bent surface on which the optical sheet of the light-guiding plate 4 is arranged in the liquid crystal display device shown in FIG. 9 instead of providing the protruding part 20 a . Also according to such a structure, an effect similar to the case in which the protruding part 20 a is provided can be obtained.
A description will now be given of a third embodiment of the present invention.
First, a description will be given of a mode of heat radiation from a fluorescent tube is explained.
Generally, heat moves from a body to other bodies according to three kinds of forms, heat conduction, heat transfer and heat radiation. In the backlight device of a side light system as shown in FIG. 1 , the luminescence section of the fluorescent tube is arranged in the closed narrow space between the reflector and the light-guiding plate. For this reason, there are few amounts of movements of the heat according to convection of air around the luminescence section.
Moreover, since the emissivity of the inner surface of the reflector is close to 1, the reflector hardly absorbs radiation heat. Therefore, a large part of the heat emitted from the fluorescent tube reaches the reflector according to heat conduction in the air layer surrounding the fluorescent tube. Further, the electrode section of the fluorescent tube is surrounded by the fluorescent tube support section, and the heat generated in the electrode section of the fluorescent tube reaches the reflector according to heat conduction through the fluorescent tube support section.
As mentioned above, a large part of heat from the fluorescent tube is transmitted to the reflector according to heat conduction, and is emitted further to outside from the reflector. Here, an amount Q [W] of heat, which moves according to heat conduction, can be expressed by the following equation.
Q =λ/δ( Ti−To ) A [W]
In the above equation, λ represents a thermal conductivity [W/(m·K)] of a medium through which heat moves, δ represents a thickness [m] of the medium, Ti and To express a wall-surface temperature [K] of the medium, and A represents a cross-sectional area [m 2 ] of the medium.
When surrounded by an air layer like the luminescence section of the fluorescent tube, an amount of heat release, that is, an amount Q of transfer of heat can be adjusted by adjusting the thickness δ of the air layer since the thermal conductivity of air is almost constant, 0.026 [W/(m·K)]. Namely, what is necessary is to adjust a distance between the luminescence section of the fluorescent tube and the reflector. Moreover, an amount of heat released from the electrode section can be adjusted by adjusting a thickness of the fluorescent tube support member.
Therefore, in order to adjust the amount of heat release by both the luminescence section and the electrode section of the fluorescent tube, it is necessary to adjust independently both the distance between the inner surface of the reflector and the luminescence section of the fluorescent tube and the distance between the inner surface of the reflector and the electrode section of the fluorescent tube. Such an adjustment can be achieved by providing a step to the reflector.
FIG. 11 is a perspective view of the light source provided in the liquid crystal display device according to the third embodiment of the present invention. The light source 40 shown in FIG. 11 is provided instead of the light source 3 shown in FIG. 3 .
In the light source 3 shown in FIG. 3 , the reflector 3 c has a uniform cross-sectional configuration, and is provided around the fluorescence tube 3 a and the fluorescent tube support members 3 b . On the other hand, in the light source 40 shown in FIG. 11 , the cross-sectional configuration of a reflector 46 differs between a portion surrounding fluorescent tubes 42 and a portion surrounding fluorescent tube support members 44 .
FIG. 12 is an exploded perspective view of the light source 40 . A step part 46 a is formed in the vicinity of each end of the reflector 46 so that the fluorescent tube support member 44 is provided to a portion between the step part 46 a and the end of the reflector 46 . Therefore, the fluorescent tubes 42 are provided in a portion between the opposite step parts 46 a of the reflector 46 .
In the light source 40 having the reflector 46 of the above structure, heat emitted from a glass tube heat-emitting section (luminescence section) 42 a of the fluorescent tube 42 reaches the reflector 46 through the air layer around the fluorescent tube 42 , and is further released outside from the reflector 46 . On the other hand, heat emitted from the electrode section 42 b of the fluorescent tube 42 reaches the reflector 46 through the fluorescent tube support member 44 , and is further released outside from the reflector 46 .
As mentioned above, the step part 46 a is provided between the portion of the reflector 46 surrounding the glass tube heat-emitting section 42 a and the portion of the reflector 46 surrounding the fluorescent tube support member 44 . Thereby, the distance between the inner surface of the reflector 46 and the fluorescent tube 42 are varied.
FIG. 13 is a cross-sectional view of the portion of the reflector which portion surrounds the glass tube heat-emitting part 42 a . FIG. 14 is a cross-sectional view of the reflector 46 which portion surrounds the fluorescent tube support member 44 . The distance between the inner surface of the reflector 46 and the fluorescent tube 42 is indicated by D 1 in FIG. 13 and D 2 in FIG. 14 . Adjustment of the distances D 1 and D 2 is made by changing a length L of an opening and a radius R of curvature of a bent portion of the reflector 46 as shown in FIG. 15 .
In the fluorescent tube, since an amount of heat generated in the electrode section is larger than an amount of heat generated in the luminescence section, the distance D 2 shown in FIG. 14 is set smaller than the distance D 1 shown in FIG. 13 . That is, it is constituted so that an amount of heat released from the electrode section 42 b of the fluorescent tube 42 is larger than an amount of heat released from the luminescence section 42 a.
Moreover, the fluorescent tube support member 44 is preferably made of an insulating material having a high thermal conductivity equal to or more than 0.5 [W/(m·K)] so as to increase the heat release efficiency. As for such an insulating material, a commercially available silicone sealant having a high heat conductivity, for example, 1.59 [W/(m·K)] may be used.
Moreover, in order to increase a heat release efficiency of the reflector 46 , the reflector is preferably made of metal or a material having a heat conductivity equivalent to metal.
As mentioned above, the temperature of the fluorescent tube can be adjusted with high accuracy by adjusting an amount of heat release based on the amount of heat release which varies between portions of the fluorescent tube. Thus, the temperature of the luminescence section of the luminescent tube can be adjusted to maintain a temperature at which the maximum luminescence efficiency is obtained.
Moreover, since the temperature of the electrode section can be lowered by increasing an amount of heat released from the electrode section of fluorescent tube, the temperature of a solder connecting part provided to the fluorescent tube support member can also be lowered, thereby improving the reliability of the solder connecting part. Furthermore, the light-guiding plate and the plastic frame arranged around the fluorescent tube are prevented from thermal deformation and thermal degradation.
The present invention is not limited to the specifically disclosed embodiments, and variations and modifications may be made without departing from the scope of the present invention.
The present application is based on Japanese priority application No. 2001-236400 filed on Aug. 3, 2001, the entire contents of which are hereby incorporated by reference.
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A liquid crystal display device irradiates a light of a light source from a backside of a liquid crystal panel. A light-guiding plate provided under the liquid crystal panel guides the light of the light source to the liquid crystal panel by transmitting the light therethrough. An optical sheet is arranged between the liquid crystal panel and the light-guiding plate. A backlight housing accommodates the light-guiding plate and the optical sheet. The optical sheet has a protruding part extending outwardly from a periphery thereof. The backlight housing has an opening at a position corresponding to the protruding part.
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BACKGROUND OF THE INVENTION
1. Field of the Invention
This invention is concerned with a hot-cathode material in wire and sheet form and with a process for its production.
2. Description of the Prior Art
Hot-cathode materials for thermionic tubes are known in the art in numerous embodiments and with numerous combinations of materials. They range from the conventional oxide cathodes having a low operating temperature and a low emission current density but a long life, to complicated multi-material systems such as the so-called "reactive cathodes". The most widely used materials of the latter category are cathode materials of the type W/W 2 C/ThO 2 ("thoriated tungsten cathodes"), which operate on the basis of a chemical reaction and supply of the activator from the interior and which have a relatively high operating temperature. They are distinguished by a long life coupled with moderate emission current density. It can be demonstrated that the work function of the electrons can be lowered and that the electrode emission properties can be improved by adding a platinum metal to the above-mentioned system (see, for example, German Offenlegungsschrift No. 1,614,541). Materials are also known which have a medium life and a higher emission current density, examples of such materials being the systems Mo/Mo 2 C/La 2 O 3 (see German Auslegeschrift No. 2,344,936) and Mo/Mo 2 C/La 2 O 3 /Pt metal and the like (see German Auslegeschrift No. 2,454,569). Hot-cathode materials are also known which are based on porous sintered bodies produced from powder mixtures of a high melting metal with a platinum metal, the pores of the sintered bodies being filled with a material containing the activator (see, for example, German Offenlegungsschrift No. 2,727,187). Such cathodes are particularly distinguished by high emission current density coupled with relatively low operating tempertures.
The above-mentioned cathode materials are almost exclusively sintered materials which are used in the form of small sheets, tablets and similar compact components for the manufacture of hot-cathodes. These materials are distinguished by a certain brittleness so that, in general, they cannot be shaped or can only be shaped with extreme difficulty or by accepting substantial deterioration in their physical properties. Their lack of ductility does not enable them to be produced in any desired dimensions or, for example, to be converted economically to wires, sheets and strips, which would enable their high emission current density to be used in practice. On the other hand, the available materials with a high emission current density which can be produced in these physical forms have a service life that is still too short for practical use, particularly in the case of small sizes. There is, therefore, a requirement for materials which combine, in an optimum manner, the good properties of the above-mentioned materials and which allow the design engineer maximum possible freedom in design.
SUMMARY OF THE INVENTION
A hot-cathode material has now been developed which combines good mechanical shaping characteristics with high heat resistance, toughness and insensitivity to shock, and which can be used to provide hot-cathodes which combine a high emission current density and a long life with a low heating power requirement.
According to one aspect of the present invention, a hot-cathode material in wire or sheet form is provided which is composed of a high-melting carrier metal, an oxide of a Group IIIb metal as activator, and a carbide of the carrier metal as reducing agent, and, optionally, a diffusion-promoting additive. The hot-cathode material is provided with a core zone and at least one surface layer having different compositions or different concentrations of constituents therein which are such that, in operation, the rate of diffusion of the activator from the core zone is equal to or greater than the loss of activator from the surface layer.
According to another aspect of the invention, a process is provided for the production of a hot-cathode material which comprises mixing powdered carrier metal having a particle size of 8.5μ to 10μ with a powdered activator having a particle size of 1.0μ to 10μ, isostatically cold pressing the mixture under a pressure of 1,000 to 8,000 bar, heating the blank thus produced in a reducing hydrogen atmosphere at a temperature of 900° C. to 1,100° C. for 0.5 to 6 hours, sintering the blank at a temperature of 1,500° C. to 2,200° C. for 0.5 to 3 hours, and mechanically working the blank in order to shape it. At least one body so produced and intended to form the surface layer of the material is then assembled with at least one other body so produced and intended to form the core zone or an intermediate layer, or with a core comprising a diffusion-promoting additive or an intermediate layer comprising the additive, to form a composite. The workpiece thus produced is subjected alternately to a forgoing treatment at a temperature of 1,000° C. to 1,500° C. and an intermediate annealing treatment at a temperature of 1,000° C. to 1,150° C. for 15 to 60 minutes, and then alternately to a drawing or rolling treatment and the same intermediate annealing treatment. Finally, the workpiece is carburized in the form of a semi-finished article in a mixture of 0.5 to 5% by volume of CH 4 and 99.5 to 95% by volume of H 2 .
The guiding concept on which the invention is based is the recognition that the limitation of the life of a reactive cathode of the dispenser-diffusion type described here depends on various parameters which determine the reaction kinetics and the material equilibrium. In order to maintain the cathode surface during the entire life of cathode, a mono-atomic layer of the element which is derived from the activator, is formed by reduction and it lowers the electron work function (this mono-atomic layer being necessary to obtain the required high emission current density). An equilibrium must exist between the degree of vaporization of the activator (amount vaporized per unit time) and the amount of activator dispensed into the surface layer. This means that the amount of activator, originating from the interior of the cathode, dispensed into the surface zone must at any time be equal to the amount vaporized at the surface. It has been found that it is not the loss of activator throughout the cross-section of the cathode, but only the loss of activator in the surface zone near the surface which determines the equilibrium. The depletion of the life-determining surface zone can now be prevented by providing a core zone, which acts as a reservoir and which provides a higher rate of migration of the activator. This leads to a layer-type construction of the cathode material to ensure that by virtue of the greater diffusion in the core zone, sufficient activator is at all times transported into the surface zone near the surface in order to compensate for the depleting of this surface zone.
BRIEF DESCRIPTION OF THE DRAWINGS
A more complete appreciation of the invention and many of the attendant advantages thereof will be readily obtained as the same becomes better understood by reference to the following detailed description when considered in connection with the accompanying drawings, wherein:
FIGS. 1 to 5 are diagrammatic cross-sections through different embodiments of a wire cathode; and
FIG. 6 is a graph showing the life of a cathode as a function of the concentration of the activator.
DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS
FIG. 1 is a diagrammatic cross-section of a round wire of hot-cathode material which basically comprises a surface layer of 1 which is such that it permits only a relatively low radial rate of migration of the activator and a core zone 2 which is such that it permits a higher rate of migration of the activator. In general, transport of the activator depends essentially on the diffusion conditions of the particular material, from which it follows that the diffusion coefficient in zone 2 must be higher than in layer 1.
The hot-cathode material may be of any cross-section in accordance with this scheme. In other words, the material does not have to have a round cross-section, and may, for example, be polygonal or some other cross-sectional profile or in the form of a flat rod, strip or sheet.
FIG. 2 is a diagrammatic cross-section of a round wire which is formed of three layers, an outer layer 3 consisting of or containing a diffusion-promoting additive, a surface layer 4 and a core zone 5. Individual platinum metals or a mixture of such metals may be used as the diffusion-promoting additive. The surface layer 4 and the core zone 5 may comprise the same constituents, but with different concentrations of the activator; the surface layer 4 containing a lower concentration of the latter than the core zone 5. When molybdenum is used as the carrier metal, lanthanum oxide (La 2 O 3 ) is advantageously used as the activator, with the surface layer 4 having a concentration of 0.5 to 6%, preferably 0.5 to 1.5%, of the activator, and the core zone 5, a concentration of 2 to 8%, preferably 2 to 4%, of the activator. The cross-sectional area of the surface layer 4 may, for example, constitute 5 to 20% of the total cross-sectional area of the electrode.
FIG. 3 is a diagrammatic cross-section of a round wire having a different sequence of the layer-type construction. Both the core zone 5 and the surface layer 6 have a relatively high concentration of 2 to 8%, preferably 2 to 4%, of activator (for example La 2 O 3 ). The two zones are separated by an intermediate layer 7 of a platinum metal, preferably platinum, the cross-sectional area of which may account for 0.1 to 5% of the total cross-sectional area.
FIG. 4 is a diagrammatic cross-section of a further embodiment of a wire. The body of the hot-cathode material in this case mainly consists of a shell 8 of the material, containing 0.5 to 20%, preferably 2 to 6%, of activator. Within the shell 8 is a core 9 of a platinum metal, preferably Pt, which constitutes 0.1 to 2% of the total volume of the body.
FIG. 5 is a diagrammatic cross-section of a round wire which comprises a surface layer 4 having a relatively low concentration of activator, which in the case of lanthanum oxide is preferably from 0.5 to 1.5%. The core zone 10 is provided with a higher concentration of activator, for example, 2 to 4% of La 2 O 3 , and in addition contains the diffusion-promoting additive in the form of a finely divided platinum metal. In the case of platinum, a concentration of 0.3 to 0.7% is preferably used for this purpose.
FIG. 6 is a graph showing the life of hot-cathode wires as a function of the concentration of activator at the start of operation. The wires investigated had a layer sequence as shown in FIG. 2 and FIG. 4, and had an external diameter of 0.6 mm. The carrier metal was molybdenum and the activator was of lanthanum oxide. Various curves have been plotted in the diagram. Curve 11 serves for comparative purposes and represents a cathode material of conventional, not layer-type, construction, based on a molybdenum carrier modified uniformly over the entire cross-section with lanthanum oxide and provided at its surface with a thin layer of platinum, the operating temperature being 1850° K. Curve 12 shows the dependence of the operating life (mean value) on the concentration of the activator La 2 O 3 for cathodes with a layer-type construction, at an operating temperature of 1850° K. The outer broken lines indicate the range of scatter resulting from the particular construction according to the types shown in FIGS. 2 to 5. Curve 13 shows the mean value of the operating life for an operating temperature of 1820° K., the range of scatter again being marked by outer broken lines. In the experiments, the emission current density was 3.5 to 4.2 A/cm 2 .
Having generally described this invention, a further understanding can be obtained by reference to certain specific examples which are provided herein for purposes of illustration only and are not intended to be limiting unless otherwise specified.
EXAMPLE 1
Refer to FIG. 2.
To produce a surface layer or a shell, 4,400 g of molybdenum powder of a particle size of 5μ were mixed for 60 minutes with 4 g of lanthanum oxide powder (La 2 O 3 ) of particle size 1μ in a tumbler mixer. A cylinder of 18 mm diameter and 200 mm length was produced from this powder mixture and consisted of 99% by weight of Mo and 1% by weight of La 2 O 3 . The cylinder was formed by cold isostatic pressing under a pressure of 3,000 bars. The cylinder was pre-annealed under reducing conditions for 5 hours in a stream of hydrogen at a temperature of 1,000° C. This treatment substantially removed any dissolved or chemically bonded oxygen which may be present in the molybdenum. The blank was then sintered at a temperature of 1,700° C. for 1 hour to give a dense body (99.8% of the theoretical density). A hollow cylinder of 15 mm external diameter, 9 mm internal diameter and 170 mm length was then cut from the sintered body by machining.
To produce the core 5, 107.7 g of the above molybdenum powder were mixed with 3.3 g of the above lanthanum oxide powder in a tumbler mixer as described above, the content of La 2 O 3 being 3% by weight. The core was formed and further treated as described above and turned down to 9 mm external diameter and 170 mm length.
The core and shell were then assembled together. With the temperature progressively decreasing from 1,400° C. to 1,200° C., the diameter of the resulting rod was reduced from 15 mm to 3 mm by swaging. An intermediate annealing operation for 30 minutes at a temperature of 1,100° C. in a hydrogen atmosphere was performed between any two shaping steps. Finally, the round wire thus obtained was brought to a final diameter of 0.6 mm by drawing at a temperature of 1,100° C., an intermediate annealing at 1,100° C. being carried out between any two drawing operations. The wire was carburized for 60 minutes at a temperature of 1,600° C., in a mixture of 3% by volume of methane and 97% by volume of hydrogen. The material thus produced can be used directly as a cathode wire. To improve its properties, particularly to increase the emission current density, the wire was finally provided with an electrolytically applied coating of a diffusion-promoting metal. In the present example, the wire was coated with a 5μ thick layer of platinum.
It should be understood that the specific conditions of the individual process steps as described above are by way of example and can, and should, be varied in accordance with the starting material used, the dimensions to be achieved and the end use. In particular, the carrier metal powder (for example molybdenum) may have a particle size of 0.5 to 10μ, while the particle size of the activator (for example lanthanum oxide) may be from 0.1 to 10μ. The cold isostatic pressing may be carried out under pressures of 1,000 to 8,000 bars. The preliminary annealing may be carried out for 0.5 to 6 hours in a temperature range of 900° to 1,100° C. and the sintering may be carried out for 0.5 to 3 hours in a temperature range of 1,500° to 2,200° C. The swaging process may be carried out in a temperature range of 1,500° to 1,000° C. and the intermediate annealing at 1,000° to 1,150° C., the duration of the latter preferably being 15 to 60 minutes. Advantageously, carburation is conducted with a mixture of 0.5 to 5% by volume of CH 4 , the remainder H 2 , at temperatures of 1,500° to 1,700° C. The platinum layer applied may have a thickness of 1 to 10μ.
EXAMPLE 2
Refer to FIG. 3.
A hollow cylinder serving as the shell and a core serving as the central body of an electrode were produced as described in Example 1. The core and the shell have the same content of activator, that is 3% by weight La 2 O 3 . Before assembling, the core was provided with an electrolytically deposited layer of platinum, 200μ thick. The core and the shell were then assembled and further processing was carried out exactly as described in Example 1.
The thickness of the diffusion-promoting additive deposited as an intermediate layer may be 1 to 250μ, depending on the dimensions and the end use.
EXAMPLE 3
Refer to FIG. 4.
A hollow cylinder serving as the shell was produced as described in Example 1; it contained 4% by weight of La 2 O 3 and had a bore of 1 mm diameter. A platinum wire of 1 mm diameter serving as the diffusion-promoting additive was inserted into the bore. Further shaping was then performed as described in Example 1.
The thickness of the central body which forms the core and contains the diffusion-promoting additive (for example, platinum), or consists exclusively of the latter, may be 0.1 to 10 mm.
EXAMPLE 4
Refer to FIG. 5.
A hollow cylinder containing 1% by weight of La 2 O 3 as the activator was produced as the shell by the process described in Example 1. A core, which in addition to 3% by weight of lanthanum oxide, contained 0.5% by weight of platinum was also produced. The platinum was added in the form of platinum black of a particle size of 0.5μ when the powdered starting materials were mixed. The further processing of the core and of the assembled body consisting of core and shell was carried out as described in Example 1.
The content of diffusion-promoting additive (for example, platinum) in the core may be from 0.1 to 1% weight and its particle size may be from 0.1 to 10μ.
The hot-cathode material according to the invention and the process for its manufacture are not limited to the Examples described above and shown in the Figures. In particular, carrier metals other than molybdenum, for example, tungsten, niobium or tantalum, or alloys of two or more of these metals can also be used. The same is true of the activators, where, in addition to lanthanum oxide, for example, yttrium oxide (Y 2 O 3 ) or thorium oxide (ThO 2 ) can be used. The diffusion-promoting additive can be a platinum metal other than platinum itself, for example, palladium, rhodium, ruthenium and osmium, and alloys of two or more of these elements.
The process described above and the layer sequence of the hot-cathode material shown in the Figures furthermore is not limited to round wire cross-sections. Other profiles, as well as strips and sheets can also be produced with a similar large structure, in which case the swaging and hot-drawing steps may be replaced partially or entirely by hammering, pressing or hot-rolling operations. Extrusion of profiles is another possible type of shaping. It is only necessary to ensure that the layer-type structure of the starting body is preserved in the final semi-finished article obtained.
The hot-cathode material according to the invention is a material which, while retaining excellent mechanical properties such as heat resistance and high toughness, permits, by virtue of its ductility, optimum conversion to wire and sheet form, thus allowing the designer of high output thermionic tubes maximum possible freedom in shape and arrangement. By virtue of the layer-type construction of this material, the components produced therewith combine a relatively high emission current density with a long life.
Having now fully described this invention, it will be apparent to one or ordinary skill in the art that many changes and modifications can be made thereto without departing from the spirit or scope of the invention set forth herein.
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A hot-cathode material in wire or sheet form, comprising a high-melting carrier metal, an oxide activator and a carbide reducing agent, and, optionally, a diffusion-promoting additive, the material comprising a core zone and at least one surface layer having different compositions or different concentrations of constituents therein which are such that, in operation, the rate of diffusion of the activator from the core zone is equal to or greater than the loss of activator from the surface layer. The material is made by a powder metallurgy/thermo-mechanical process.
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TECHNICAL FIELD
[0001] The present invention relates to an information processing system and method providing a remote access.
BACKGROUND
[0002] People today use multiple digital devices which are interconnected by various kinds of LAN (Local Area Network) and PAN (Personal Area Network) technologies. UPnP™ (Universal Plug and Play) and DLNA® (Digital Living Network Alliance) are standards focusing on the media consumption within home LANs, and allow users to play for example media stored in their network accessed storage (NAS) on a TV set in their living room. Furthermore, people have multiple portable devices and gadgets that are getting connected by LAN and PAN technologies while walking on the streets. At the same time, a lot of services are available in the Internet, offered by service providers or even by the user's own home networks, accessible through WAN (Wide Area Network) technologies. Numerous video sharing sites are available on the Internet. Also, many Internet radio stations are available, and Podcast sites offer audio and video together with well-formed meta-data.
[0003] As described in US20050210155, a service provider may expose the service in a residential network, a LAN for example, in the form of a virtual device. FIG. 1 illustrates an information processing system 100 to provide a virtual device. A LAN 110 is a residential network of a user 160 , including an IG (INS Gateway) 111 and a local device 113 . The local device 113 connects an IMS (IP Multimedia Subsystem) environment 120 via the IG 111 . The IMS environment 120 includes a PNAS 121 to create a virtual device as a composition of multiple services provisioned by a service provider (SP) 130 . The virtual device implements one or more virtual services 112 provided by the IG 111 . The IG 111 announces the virtual service 112 for the LAN 110 using a protocol supported there such as UPnP. The local device 113 can obtain a description of the service profile provided by the IG 111 and access to the service profile. The access to the virtual service 112 is translated to an access to the PNAS 121 , and the result returned by the service provider 130 is again translated to the protocol supported by the LAN 110 and returned to the local device 113 .
[0004] The PNAS 121 collects the context information from the LAN 110 and exposes the context information to service providers and end users. The context information contains the capability of the local device 113 , sensors and actuators in the LAN 110 and services provided by them. It is updated when there is some event occurred in the local device 113 or a status in the local device 113 has changed. The IG 111 works as an intermediary entity to publish the context information towards the PNAS 121 in the secure and effective manner.
[0005] The IMS environment 120 may provide the user 160 with a remote access to the LAN 110 . The user 160 accesses to services in the LAN 110 remotely using a user equipment 150 . A service provider 140 provides the user equipment 150 with this remote access. The service provider 140 retrieves the service description of the virtual service 112 from the PNAS 121 and presents this service description to the user equipment 150 . When the service provider 140 receives a request for the virtual service 112 from the user equipment 150 , the service provider 140 transfers this request to the IG 111 after appropriate protocol conversions. The IG 111 executes the virtual service 112 and returns the result to the user equipment 150 .
[0006] To execute the virtual service 112 , the IG 111 requires the native service provisioned by the service provider 130 . That is, the request from the user equipment 150 traversed the path of the service provider 140 , the IG 111 , and the service provider 130 , and the response traverses the return path. This causes a trombone routing and the user 160 may experience a long latency.
SUMMARY
[0007] According to an aspect of the invention, an information processing system for offering a remote access from a device to a virtual service provided in a local network is provided. The virtual service invokes one or more native services provisioned by a service provider or invoking both the one or more native services and one or more local services provisioned by a local device resided in the local network. The system comprising: a management unit configured to manage service information specifying a shortcut component of the virtual service, the shortcut component executable by invoking one or more native services without invoking a local service; an obtaining unit configured to obtain a request for the virtual service from the device; a receiving unit configured to receive the service information from the management unit; a specification unit configured to specify a shortcut component for the requested virtual service based on the received service information; an invoking unit configured to execute the specified shortcut component by invoking one or more native services to the service provider, and to transfer the other component of the requested virtual service to the local network; a combination unit configured to combine results of executing the one or more invoked native services and a result responded from the local network; and a response unit configured to respond the combined result to the device.
[0008] Further features of the present invention will become apparent from the following description of exemplary embodiments with reference to the attached drawings.
BRIEF DESCRIPTION OF DRAWINGS
[0009] FIG. 1 illustrates an environment providing a virtual service.
[0010] FIG. 2 illustrates an exemplary environment including an information processing system 200 according to the first embodiment.
[0011] FIG. 3 illustrates an exemplary block diagram of the PNAS 221 according to the first embodiment.
[0012] FIG. 4 illustrates an exemplary block diagram of the IG 211 according to the first embodiment.
[0013] FIG. 5 illustrates exemplary operations of an information processing system 200 according to the first embodiment.
[0014] FIG. 6 illustrates exemplary operations of an information processing system 200 according to the first embodiment.
[0015] FIG. 7 illustrates exemplary operations of an information processing system 200 according to the first embodiment.
[0016] FIG. 8 illustrates an exemplary environment including an information processing system 800 according to the second embodiment.
[0017] FIG. 9 illustrates an exemplary environment including an information processing system 900 according to the third embodiment.
[0018] FIG. 10 illustrates exemplary operations of an information processing system 900 according to the third embodiment.
DETAILED DESCRIPTION
[0019] Embodiments of the present invention will now be described with reference to the attached drawings. Each embodiment described below will be helpful in understanding a variety of concepts from the generic to the more specific. It should be noted that the technical scope of the present invention is defined by claims, and is not limited by each embodiment described below. In addition, not all combinations of the features described in the embodiments are always indispensable for the present invention.
First Embodiment
[0020] FIG. 2 illustrates an exemplary environment including an information processing system 200 according to first embodiment of the present invention. The environment includes a LAN 210 , an IMS environment 220 , a service provider 230 , another service provider 240 , and a user equipment 250 .
[0021] The LAN 210 is a network which a user 260 uses personally, for example a home network and an in-car network. The LAN 210 includes a local device 213 , which may be for example a TV, a game console, or a Home NAS. The LAN 210 may include more than one local device. The local device 213 provides the user 260 with one or more local services. The LAN 210 also may include even multiple user LANs and PANs. The LAN 210 may be a DLNA® network or may support the communication according to one or more of the following standards DLNA®/UPnP™, Bonjour® Zeroconf, Bluetooth®, ZigBee®, and IEEE 802.15.4 variants. Bonjour® may be used for media consumption in a LAN environment. Bluetooth® may be used for discovery and communication between devices, including audio playback in a PAN. ZigBee® and IEEE 802.15.4 variants may be used for sensor and actuator devices for, for example, home automation scenario.
[0022] The LAN 210 also includes an IG (IMS Gateway) 211 . The IG 211 is an application layer gateway device between the IMS environment 220 and the LAN 210 . The transportation and authentication of messages between the local device 213 and the IMS environment 220 are intermediated by the IG 211 and secured by security mechanisms provided by the IMS environment 220 .
[0023] The service provider 230 is included in the Internet for example and provides one or more services. Hereinafter, services provided by the service provider 230 are called “native services.”
[0024] The user 260 accesses to the LAN 210 from the outside using the user equipment 250 . The user equipment 250 may be a mobile phone, a personal computer, a digital player, and the like. Another service provider 240 retrieves the information of the virtual devices from the PNAS 221 to provide a service to the user equipment 250 . The service provider 240 allows the user 260 to access to the LAN 210 remotely.
[0025] The IMS environment 220 is managed by a network operator and includes a PNAS (Personal Network Application Server) 221 . The PNAS 221 is an IMS enabler that allows exposing information about the LAN 210 . According to this embodiment, the PNAS 221 includes a Context Manager 222 , a VDF (Virtual Device Factory) 223 , and a VDP (Virtual Device Proxy) 224 .
[0026] The Context Manager 222 manages context information about the LAN 210 . The context information is information relating local devices in the LAN 210 , such as an internal state, capability, access history, and on-going sessions to the Context Manager 222 . The context information may include information about available services in the LAN 210 and user policies for disclosure of this information. The IG 211 discovers the local device 213 in LAN 210 and publishes the device's information to the PNAS 221 , and the Content Manager 222 aggregates the device's information of the LAN 210 as the context information. For example, the IG 211 sends UPnP M-search message to the LAN 210 . The user devices in the LAN 210 respond to the M-search from the IG 211 . The IG 211 fetches the context information from the local devices responded to the M-search. The IG 211 detects the capability of found local devices by issuing appropriate UPnP™ messages and uploads their context information to the Context Manager 222 . The virtual service provided by another IMS environment may be discovered by the IG 211 .
[0027] The VDF 223 receives a service description about a native service from the service provider 230 and provides the LAN 210 with a virtual service 212 . A virtual service may be a composition of multiple services provisioned by multiple service providers. For example, the service provider 230 provisions the web service description which contains sufficient information for the VDF 223 to create the virtual service 212 toward the LAN 210 . The VDF 223 also creates and manages service information per each virtual service 212 . The service information is information relating the virtual service 212 and includes what kind of native services and local services are invoked, how to invoke the services with what parameters and so on. The service information also includes a shortcut component of the virtual service 212 . The shortcut component is a component executable by invoking one or more native services without invoking a local service. That is, the VDP 224 does not need to transfer the shortcut component to the IG 211 . The service information may also include indications indicating when the shortcut component executes and parameters used for invoking the virtual service 212 . The VDF 223 creates the service information based on the service description provisioned by the service provider 230 and the context information retrieved from the Context Manager 222 . The VDF 223 may intercept a service request from the virtual service 212 to the native services to make the protocol translation and to update the service information. The VDF 223 may provision one or more native services and the virtual service 212 may include a native service provisioned by the VDF 223 . In this case, the VDF 223 works as a service provider.
[0028] The VDP 224 accepts a service request from the user equipment 250 , executes the requested service based on the service information, and returns the result. FIG. 2 shows only one VDP 224 . However, multiple VDPs may be prepared for one virtual service 212 .
[0029] FIG. 3 illustrates an exemplary block diagram of the PNAS 221 according to this embodiment. The PNAS 221 includes a CPU 301 , a memory 302 , the Context Manager 222 , the VDF 223 , and the VDP 224 . The CPU 301 controls overall operations of the PNAS 221 . The memory 302 stores computer programs and data used for operations of the PNAS 221 .
[0030] The VDF 223 includes a creation unit 311 and a management unit 312 . The creation unit 311 creates the virtual service 212 based on the native services provisioned by the service provider 230 . The virtual service 212 may invoke one or more native services, and may invoke both one or more native services and one or more local services provisioned by the local device 213 . The management unit 312 manages the service information.
[0031] The VDP 224 includes an obtaining unit 321 , a receiving unit 322 , a specification unit 323 , an invoking unit 324 , a combination unit 325 , a response unit 326 , and an update unit 327 . The obtaining unit 321 obtains a request for the virtual service 212 from the user equipment 250 . The obtaining unit 321 may obtain the request using a protocol supported by the LAN 210 . Further, the obtaining unit 321 may obtain a request for a local service provisioned by the local device 213 in the same way as the request for the virtual service 212 .
[0032] The receiving unit 322 receives the service information from the management unit 312 . The specification unit 323 specifies the shortcut component for the requested virtual service 212 based on the retrieved service information. The invoking unit 324 executes the specified shortcut component by invoking one or more native services to the service provider 130 , and transfers the other component of the requested virtual service 212 , if any, to the LAN 210 . The invoking unit may convert the protocol used for the obtained request to a protocol supported by the service provider 130 in order to invoke the native services. The combination unit 325 combines results of executing the invoked native services and a result responded from the LAN 210 , if any. The response unit 326 responds the combined result to the user equipment 250 . The update unit 327 requires the management unit 312 to update the service information.
[0033] FIG. 4 illustrates an exemplary block diagram of the IG 211 according to this embodiment. The IG 211 includes a CPU 401 , a memory 402 , an execution unit 403 , a determination unit 404 . The CPU 401 controls overall operations of the IG 211 . The memory 402 stores computer programs and data used for operations of the IG 211 . The execution unit 403 executes the local service and, if necessary, native services. The determination unit 404 determines whether the requested virtual service has invoked a local service. The update unit 327 obtains this determination from the determination unit 404 .
[0034] FIGS. 5 to 7 illustrate an example of overall operations of the information processing system 200 according to this embodiment. The CPU included in each device executes computer programs stored in memory of each device to process these operations.
[0035] FIG. 5 illustrates exemplary operations in which the VDF 223 provides the VDP 224 with the service information.
[0036] In Step S 501 , the creation unit 311 receives the service description of the native service from the service provider 230 . In Step S 502 , the creation unit 311 creates the virtual service 212 according to the service description and provides the IG 211 with the virtual service 212 . The creation unit 311 may composite multiple native services to create a single virtual service.
[0037] In Step S 503 , the management unit 304 retrieves the context information from the Context Manager 222 . The context information contains the information of the local device 213 in the LAN 210 . In Step S 504 , the management unit 304 creates the service information and provides the VDP 224 with the service information. In one scenario, the management unit 304 provides the service information in response to the provision of the native service in step S 501 . However, Step S 504 may be carried out anytime after the execution of Step S 501 .
[0038] FIG. 6 illustrates exemplary operations when the VDP 224 receives a service request from the user equipment 250 . These operations may be performed after the VDP 224 obtains the service information. Alternatively, the VDP 224 may obtain the service information in response to a request from the user equipment 250 toward the virtual service 212 .
[0039] In Step S 601 , the obtaining unit 321 obtains a request for a service from the user equipment 250 via the service provider 240 . The requested service may be a virtual service, or a local service provisioned by the local device 213 . An example of the local service is file access in the LAN 210 . In an example, the communication between the service provider 240 and the VDP 224 is done using SIP, and the service provider 240 can send an UPnP command over the SIP in order to control the target UPnP device, no matter if it's a real UPnP device or a virtual one. Other protocols than SIP may also be utilized. In one scenario, the user 260 opens a web browser and accesses a web site provided by the service provider 240 using the user equipment 250 . The service provider 240 sends an UPnP action over SIP to control the virtual device to the VDP 224 .
[0040] In Step S 602 , the specification unit 323 determines whether the requested service is a virtual service or a local service. The obtaining unit 321 may obtain a request to the virtual service 212 and handle it in the same manner as a request to the local service. When the requested service is a local service, the process proceeds to Step S 603 and the invoking unit 324 forwards the request to the LAN 210 after appropriate protocol conversions. In Step S 607 , the response unit 326 responds a result responded from the LAN 210 to the user equipment 250 .
[0041] When the requested service is a virtual service, the process proceeds to Step S 604 . In Step S 604 , the receiving unit 322 receives the service information for the requested virtual service. The management unit 312 may push the service information to the receiving unit 322 prior to a request and the service information may have already been stored in the memory 302 . If the service information has not obtained yet, the receiving unit 322 retrieves the service information from the management unit 312 .
[0042] Steps S 605 to S 607 are described in detail in FIG. 7 . In Step S 701 , the specification unit 323 specifies a shortcut component for the requested virtual service based on the service information.
[0043] In Step S 702 , the invoking unit 324 executes the specified shortcut component by invoking one or more native services to the service provider 230 . The invoking unit 324 translates the UPnP action into a SOAP request according to web service description of the service provider 230 , and sends the SOAP request to the service provider 230 .
[0044] In Step S 703 , the invoking unit 324 transfers the other component of the requested virtual service 212 to the LAN 210 . In Step S 704 , the service provider 230 returns the result of the execution of the native service. The SOAP response from the service provider 230 is then translated into an UPnP response. In Step S 705 , the execution unit 403 returns the result of the execution of the local service.
[0045] The shortcut component may include multiple shortcut subcomponents. The other component of the requested virtual service 212 may also include multiple local subcomponents. The shortcut subcomponents and the local subcomponents may depend on each other. For example, a local subcomponent may require a result of execution of a shortcut subcomponent as a parameter.
[0046] In Step S 706 , the combination unit 325 combines the results from both the service provider 230 and the execution unit 403 . In Step S 707 , the response unit 326 responds the combined results to the user equipment 250 .
[0047] If there is no other component in Step S 701 , that is, the requested virtual service 212 is executed without invoking a local service, Steps S 703 , S 705 , and S 706 may be omitted. On the other hand, if there is not a shortcut component, Steps S 702 , S 704 , and S 706 may be omitted.
[0048] The request may require local services depending on the parameters for the request. In this case, since the service information may not specify a shortcut component, the invoking unit 324 may simply forward the request to the virtual device at Step S 703 . In Step S 708 , the determination unit 404 may determine whether the processing of the request has involved any local services. If it hasn't, in Step S 709 , the determination unit 404 may send this determination and the update unit 327 may obtain this determination. This determination process in Step S 709 may be performed between Steps S 703 and S 705 , and in this case, the determination result may be sent with the execution result of the local service in Step S 705 . In Step S 710 , the update unit 327 may require the management unit 312 to update the service information of the required virtual service based on the determination. The management unit 312 manages the parameters as a shortcut component of the virtual service 212 . The management unit 312 may inform this update to the VDP 224 and other VDPs if any. Alternatively, the invoking unit 324 may manage the parameters locally and may determine whether the invoking unit 324 should transfer the other component hereafter based on the parameters.
[0049] Instead of Steps S 708 and S 709 , the invoking unit 324 may send the request to both the virtual service 212 and the service provider 230 . If they return the same response for the given parameter set, then the invoking unit 324 can forward the request only to the service provider 230 from the next time. Therefore, in this case, the update unit 327 also performs Step S 710 . Note that this method is applicable only when the request does not change any state in the virtual service 212 and the service provider 230 and it does not have any side-effects.
[0050] According to this embodiment, access latency is improved when the user equipment 250 requests the virtual service 212 . Further, a service accessing a virtual device is kept de-coupled from the service provider providing the virtual device.
Second Embodiment
[0051] FIG. 8 illustrates an exemplary environment including an information processing system 800 according to second embodiment of the present invention. Like components according to the first embodiment are given like reference numerals. The environment includes a LAN 210 , an IMS environment 220 , a service provider 230 , another LAN 810 .
[0052] The LAN 810 includes another IG 811 and a user equipment 813 . According to this embodiment, the VDP 812 is included in the IG 811 . A user 814 establishes a remote access session from the user equipment to the LAN 210 via the IMS embodiment 220 . After the remote access session is established, the remote access server (RAS) 801 in the IG 211 exposes the information of the devices to the IG 811 . At this point, the IG 211 notices that one of the devices is a virtual device and doesn't expose it.
[0053] The IG 211 requests the VDF 223 to provide the virtual service 212 to the IG 811 . The remote access client (RAC) 815 advertises the virtual service 212 in the LAN 810 as well as the other local devices, and discovered by the UPnP CP. The user 814 manipulates the UPnP CP in the user equipment 813 and an UPnP action is sent to the RAC 815 in the IG 811 . The RAC 815 forwards the request to the VDP 812 . The VDP 812 performs operations as shown in FIGS. 5 to 7 . According to this embodiment, the receiving unit 322 may retrieve the service information when the remote access session is established.
[0054] According to this embodiment, the native service provisioned by the service provider 230 is directly invoked from the IG 811 , and thus access latency is improved.
Third Embodiment
[0055] FIG. 9 illustrates an exemplary environment including an information processing system 900 according to third embodiment of the present invention. Like components according to the first embodiment are given like reference numerals. The environment includes a LAN 210 , an IMS environment 220 , another IMS environment 910 , a service provider 230 , another service provider 920 , and user equipment 930 .
[0056] The IMS environments 220 and 910 have their own PNASs, a PNAS 221 and a PNAS 911 . The PNAS 221 includes a Context Manager 222 and a VDF 223 . The PNAS 911 includes a Context Manager 912 and a VDP 913 . No data synchronization among the Context Managers is taken place. The LAN 210 includes two IGs, the IG 211 for the IMS environment 220 and the IG 901 for the IMS environment 910 .
[0057] The user 940 accesses to the virtual service 212 in the LAN 210 using the user equipment 930 . The service request for the virtual service 212 is intercepted by the VDP 913 and the VDP 913 performs operations as shown in FIGS. 5 to 7 . According to this embodiment, the native service provisioned by the service provider 230 is directly invoked from the IMS environment 910 , and thus access latency is improved.
[0058] FIG. 10 illustrates exemplary operations in which the VDF 223 provides the VDP 913 with the service information. The CPU included in each device executes computer programs stored in memory of each device to process these operations.
[0059] In Step S 1001 , the creation unit 311 receives the service description of the native service from the service provider 230 . In Step S 1002 , the creation unit 311 creates the virtual service 212 according to the service description and provides the IG 211 with the virtual service 212 . The creation unit 311 also provides the IG 211 with a contact information of the management unit 312 . The contact information may include a URL, an IP address and a port number, or the like. In Step S 1003 , the management unit 312 retrieves the context information from the Context Manager 222 . The context information contains the information of the local device 213 in the LAN 210 . In Step S 1004 , the IG 901 is connected to the LAN 210 . In Step S 1005 , the IG 901 discovers the virtual service 212 . In Step S 1006 , the IG 901 publishes the information of the virtual service 212 to the Context Manager 912 in the IMS environment 910 . In Step S 1007 , the Context Manager 912 provides the context information of the virtual service 212 to the management unit 312 in the VDF 223 based on the contact information. The management unit 312 creates or updates the service information based on the discovered virtual service 212 . In Step S 1008 , the management unit 312 pushes the updated service information to the receiving unit 322 . In this scenario, the VDF 223 provides the VDP 913 with the service information when the virtual service 212 is discovered by the IG 901 .
[0060] The virtual service may be provisioned by a third party. When the IG 211 is connected to the LAN 210 , the IG 211 may discover a virtual service which has already provisioned by a third party. As another example, when the third party provisions a virtual service, the IG 211 which has already been connected to the LAN 210 may discover the virtual service. In these cases, the IG 211 , the Context Manager 222 , and the VDF 223 may perform the above steps S 1005 to S 1008 .
Other Embodiments
[0061] In the above Embodiments, the VDF 223 may be deployed in another entity than the PNAS 221 . The VDF 223 may access to the Context Manager 222 in the PNAS 221 through a pre-defined API, or the VDF 223 may completely rely on the service description of the Native Services. The VDF 223 may also simply be provided by the Service provider 230 itself. The virtual service 212 may be provided other local device than the IG 111 . The VDF 223 may be included in an unmanaged network, for example the Internet. The VDP 224 may also be included in the same or another unmanaged network.
[0062] In the above Embodiments, a user equipment requests for a virtual service. However, other devices may request for a virtual service. For example, in FIG. 2 , the service provider 240 may request for the virtual service 212 in preparation for a user request.
[0063] While the present invention has been described with reference to exemplary embodiments, it is to be understood that the invention is not limited to the disclosed exemplary embodiments. The scope of the following claims is to be accorded the broadest interpretation so as to encompass all such modifications and equivalent structures and functions.
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An information processing system for offering a remote access from a device to a virtual service provided in a local network is provided. The virtual service invokes native services provisioned by a service provider. The system comprising: a management unit managing service information specifying a shortcut component of the service: an obtaining unit obtaining a request for the virtual service from the device; a receiving unit receiving the service information from the management unit; a specification unit specifying a shortcut component for the requested virtual service based on the received service information; an invoking unit executing the specified shortcut component by invoking native services to the service provider, and transferring the other component of the requested virtual service to the local network; a combination unit combining results; and a response unit responding the combined result to the device.
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FIELD OF THE INVENTION
The present invention relates to new elastomers obtained from blends of fluorinated rubber and hydrocarbon rubber wherein as fluorinated rubber is meant a rubber based on vinylidene fluoride (VDF) and as hydrocarbon rubber is meant a hydrocarbon elastomer having at least one acrylic monomer as base monomer.
BACKGROUND OF THE INVENTION
The fluorinated elastomers (FKM) perfomance, intended as the set of mechanical properties, compression set, thermal and chemical resistance, are notably higher than those of hydrocarbon rubbers. Such high performances of fluorinated elastomers involve however rather high costs making their use very restricted. This is due to the higher cost of the monomers and to the process technology used in their preparation.
As a consequence the users of elastomers are obliged to choose between two elastomeric families which are completely different in terms of performances and costs: fluorinated elastomers and hydrocarbon elastomers.
There was the need to have available elastomers showing superior properties in terms of thermal and chemical resistance compared with hydrocarbon elastomers used at present.
The U.S. Pat. No. 4,251,399 describes a blend formed by an iodine-containing fluoroelastomer and a hydrogenatd elastomer, said blend is crosslinked by peroxidic way. Besides, it is pointed out that the fluoroelastomers to be used must contain a peroxidic cure-site, for example iodine.
It is also known in the art, see for example U.S. Pat. No. 5,412,034, a co-curable blend formed by a fluoroelastomer and a hydrocarbon elastomer showing good properties after curing. In said patent the blend is crosslinked by peroxidic way in the case the fluoroelastomer contains a cure-site, particularly bromine. If the fluoroelastomer does not contain a cure-site, such as bromine or iodine, then an ionic crosslinking system is used, for example amines or bisphenol in combination with quaternary phosphonium salts.
According to U.S. Pat. No. 4,251,399 and U.S. Pat. No. 5,412,034, the crosslinking through peroxidic way of the blends of hydrocarbon and fluorinated elastomers is characterized by the presence of iodine and/or bromine cure-sites in the fluoroelastomer.
Said fluoroelastomers, well known in the art, can be prepared in the presence of cure-site monomers containing iodine and/or bromine, as described in U.S. Pat. No. 4,035,565, U.S. Pat. No. 4,745,165 and EP 199,138 Patents, and/or in the presence of chain transfer agents containing iodine and/or bromine, where said transfer agents give rise to iodinated and/or brominated endgroups, as described in U.S. Pat. No. 4,243,770 and U.S. Pat. No. 5,173,553.
Said iodine and/or bromine containing fluoroelastomers during the vulcanization, in the presence of an organic peroxide, have the disadvantage to develop toxic substances such as methyl and ethyl iodide and bromide. Methyl iodide and bromide are particularly harmful.
In order to solve such drawbacks, in EP 373,973 substances capable to prevent, or at least to substantially reduce methyl and ethyl iodide and bromide emissions are described.
To this purpose in U.S. Pat. No. 5,153,272 specific peroxides, such as bis-(1,1-dimethylpropyl) peroxide, are described as capable of reducing the above emissions.
SUMMARY OF THE INVENTION
The Applicants have now surprisingly and unexpectedly found that it is possible to obtain new elastomers, curable by peroxidic way, formed by a blend of fluoroelastomers and hydrocarbon elastomers said blend non containing iodine and/or bromine. These new elastomers, after vulcanization, show improved chemical and thermal resistance with respect to hydrocarbon elastomers.
It is, thus, an object of the present invention a compound comprising a peroxide and a curable blend consisting essentially of hydrocarbon elastomers containing at least an acrylic monomer and of fluorinated elastomers based on VDF, said fluorinated elastomers having in the polymer chain at least 5 by moles of hydrogenated groups C 1 of the type ##STR2## --CH 2 -- and/or --CH 3 , the amount of fluorinated elastomer in the elastomeric blend being comprised from 5 to 75% by weight, preferably from 15 to 50% by weight, said elastomers of the blend not containing iodine and/or bromine.
DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS
The mixing of the hydrocarbon rubber and of the fluorinated rubber can be carried on in a closed mixer (Banbury) or in an open mixer. In alternative it is possible to co-coagulate said rubbers starting from their respective latexes obtained through the conventional polymerization techniques in emulsion and/or microemulsion.
The cured rubber obtainable from the curable blend of the present invention shows a set of characteristics which are superior than those of the hydrocarbon rubbers, particularly as regards the thermal and chemical resistance.
The compound comprising the blend of the hydrocarbon and fluorinated rubbers and the peroxides for the crosslinking, can optionally contain other components referred to 100 phr of the elastomer blend such as: coagents for the peroxidic crosslinking; metal oxides, (e.g., PbO, ZnO, MgO), generally in amounts from 0 to 10 phr; fillers, e.g. carbon black, silica, clay or talc, generally in amounts from 5 to 80 phr; suitable processing aids such as, for example, fatty acids or their alkyl esters or their salts or their amides or their mixtures, as stearic acid, alkaline metals stearates such as sodium and potassium, alkyl stearates; as stabilizers, for example antioxidants such as substituted diphenylamines (for example Naugard® 445).
As suitable commercial processing aids it can be used any of those known for the processing of hydrogenated and/or fluorinated rubbers. It can be mentioned as example Gleak® G 8205, Carnauba Wax® and Armid-O® which is the preferred. The cited formulation is carried on in a closed or open mixer.
The fluoroelastomers of the invention are based on vinylidene fluoride (VDF), as for example the copolymers of hexafluoro-propene (HFP), and optionally of tetrafluoroethylene (TFE).
Other monomers, fluorinated and not, can be present. For example chlorotrifluoroethylene (CTFE), ethylene (E) and perfluoroalkylvinylethers with the alkyl from 1 to 4 carbon atoms, for example perfluoromethylvinylether (MVE) and perfluoropropylvinylether (PVE).
Among the fluoroelastomers having the cited monomers can be mentioned, for example: TFE/VDF/MVE; VDF/HFP/E; E/TFE/MVE. Said fluoroelastomers are well known in the art, see, for example EP 525,685, EP 525,687 and EP 518,073, herein incorporated by reference.
As already said, the fluorinated elastomers of the present invention are characterized by having at least 5% by moles of hydrogenated groups C 1 (having 1 carbon atom), preferably at least 15% by moles. More preferred are the fluorinated elastomers such as VDF/HFP and VDF/HFP/TFE containing hydrogenated groups C 1 in amounts of at least 30% by moles. Said hydrocarbon groups can be determined for example by NMR analysis.
The hydrocarbon elastomers of the present invention are (co)polymers containing at least one acrylic monomer.
The acrylic monomer content in the hydrocarbon elastomer is generally comprised from 20 to 100% by moles, preferably from 40 to 100% and more preferably from 90 to 100%. The difference to 100 can be done, for example by: hydrocarbon monomers such as, for example, hydrogenated alpha olefins such as ethylene and propylene; hydrocarbon dienic monomers such as butadiene; vinyl esters of the carboxylic acid C 2 -C 8 such as vinyl acetate, vinyl propionate, vinyl 2-ethylhexanoate; olefins with other functional groups (for example allylglycidylether).
Among the most known acrylic monomers can be cited: alkyl acrylates which include C 1 -C 8 alkyl esters of acrylic and methacrylic acids, among which preferred are methyl acrylate, ethyl acrylate (EA) and butyl acrylate (BA), ethylhexylacrylate; alkoxy-substituted alkyl acrylates wherein the alkoxy-substituted alkyl group has from 2 to 20 carbon atoms, such as for example 2-methoxyethylacrylate, 2-ethoxyethylacrylate, 2-(n-propoxy)propylacrylate and 2-(n-butoxy)ethylacrylate; acrylates and methacrylates containing double bonds, chlorine (for example chloro-ethyl-acrylate) or other functional groups (for example glycidyl-methacrylate).
As representative examples of said hydrocarbon elastomers, the following polymers can be cited: polyethylacrylate, polybutylacrylate, polyethyl-butylacrylate, polyethylbutyl acrylate glycidylmethacrylate, poly-ethylene-methylacrylate, poly-ethylene-methyl-methacrylate, poly-ethylene-butylacrylate, etc.
Peroxides used in the crosslinking of the present invention can be aliphatic or cyclo-aliphatic, such as for example: 2,5-dimethyl-2,5-di(terbutylperoxy)hexane (LUPERCO® 101 XL), dicumyl peroxide, terbutylperbenzoate, 1,1-di(terbutylperoxy)butyrate.
The amount of peroxide used is comprised between 0.1 to 10 phr (per hundred rubber), preferably from 0.5 to 5 phr. The peroxide, if desired, can also be supported on inert material whose weight is not included in the range of values indicated for the peroxide.
The coagents are used in crosslinking systems with peroxide to improve the curing of the blend. The most preferred are polyunsaturated coagents such as: triallyl cyanurate, triallyl isocyanurate, trimethallyl isocyanurate and N,N'-m-phenylene-dimaleimide. The amount used of said coagents is comprised between 0.1 and 10 phr, preferably between 0.5 and 5 phr. If desired the-coagent can be also supported on inert material.
The inert material is well known in the art and the fillers indicated above can be cited as examples of supports. The compounds of the present invention can be used for the manufacture of O-rings, gaskets, pipes, sleeves and sheets.
The compounds of the present invention are especially useful in the manufacture of items in the automotive field, such as for instance the production of shaft-seals.
The present invention will now be better illustrated by the following working examples, which have a merely illustrative purpose, and are not limitative of the scope of the present invention.
Some characteristics of the elastomers used in the examples of the present invention are reported in Table 1.
The tensile properties have been determined according to the ASTM D 412C method.
The compression set values have been determined on O-rings according to the ASTM D 1414 method.
The Shore A hardness has been determined according to the ASTM D 2240 method. The volume variation has been determined according to the ASTM D471 method.
EXAMPLES 1-11
The hydrogenated rubber (D or E) and the fluoroelastomer (A), (B), or (C) are introduced according to the percentages indicated in Tables 2 and 3 on the rollers of an open mixer (θ=100 mm, L=200 mm) and mixed at the temperature of 25°-40° C. The so obtained elastomeric blend is added with the ingredients indicated in Tables 2 and 3 and processed in the same mixer according to the ASTM D3182 standard. The compound is characterized by analysis on oscillating disk rheometer ODR (ASTM D2084/81). The properties of the cured product are determined on compression molded plaques (130 mm×130 mm×2 mm) at 170° C. for 20 minutes and on O-rings (internal diameter equal to 25.4 mm for 3.55 mm of thickness) compression molded at 170° C. for 15 minutes. The post-treatment is carried out in an air-circulating oven.
EXAMPLE 12
The elastomeric blend formed by 70 g of hydrocarbon rubber (D) and 30 g of fluoroelastomer (A) was obtained by mixing the latexes and subsequent coagulation with aluminium sulphate and drying at 80° C. for about 16 hours. The rubbers blend was then formulated as indicated in Table 3, according to the modalities described in Examples 1-11. The obtained values of the mechanical properties and of compression set are very similar to those obtained with the mechanical mixture of the rubbers (Example 7).
EXAMPLE 13
Comparative
100 g of fluoroelastomer (A) are formulated as indicated in Table 3, according to the modalities described in Examples 1-11. It was not possible to obtain compression molded manufactured articles (O-ring and plaques) due to the poor crosslinking degree.
EXAMPLE 14
Comparative
400 g of hydrogenated rubber (D) are introduced on the rollers of an open mixer (θ=150 mm, L=300 mm), formulated as indicated in Table 4 and processed in the mixer according to the ASTM D 3182 standard. The blend characterization was carried out as indicated in Examples 1-11. The thermal and chemical resistances are reported in Table 5.
EXAMPLE 15
280 g of hydrogenated rubber (D) and 120 g of fluoroelastomer (A) are introduced on the rollers of an open mixer (θ=150 mm; L=300 mm) and mixed at the temperature of 25°-40° C. It was then proceeded as described in Examples 1-11. The thermal and chemical resistances are reported in Table 5.
The combination of properties of chemical resistance, thermal resistance at high temperature, mechanical properties and compression set is clearly superior to those obtained with the comparative Example 14.
EXAMPLE 16
The hydrogenated rubber (F) and the fluoroelastomer (A) are mixed as in example 15.
The rubber (F) has the following characteristics:
ethylacrylate (EA) 65% by mole:butylacrylate (BA) 35% by moles ML.sub.(1+10) 121° C.=43
The so obtained elastomeric blend is added with the ingredients indicated in Table 6.
The thermal and chemical resistance data are reported in Table 7.
This compound was paticularly easy to prepare in the open mixer due to the little sticking to the rolls.
TABLE 1__________________________________________________________________________ Hydrogenated C.sub.1 groupsRUBBER COMPOSITION (% by moles) ML.sub.(1+10) 121° C. (% by moles)__________________________________________________________________________A VDF/HFP 80/20 52 36B VDF/HFP/TFE 65/19/16 22 30C VDF/HFP/E 74/20/6 45 39Hydrogenated rubbers:D EA/BA 55/45 43 /E EA/BA 75/25 45 /__________________________________________________________________________
TABLE 2__________________________________________________________________________Examples 1 2 3 4 5__________________________________________________________________________FormulationHydrogenated rubber D weight % 70 70 70 70 --Hydrogenated rubber E weight % -- -- -- -- 70Fluoroelastomer A weight % 30 30 30 -- 30Fluoroelastomer C weight % -- -- -- 30 --Luperco ® 101 XL (1) phr TAIC ® 3 4,5 4 3 3drymix (2) phr TAIC ® 4 2,75 5 4 4ZnO phr TAIC ® 4 4 4 4 4Naugard ® 445 phr TAIC ® 0,8 0,8 0,8 0,8 0,8Carbon black SRF (N772) phr TAIC ® 50 50 50 50 50Gleak ® G 8205 phr TAIC ® -- 1 -- -- --ODR at 177° C., arc 3°, 24 min.ML lbf*in 3,3 3,5 3,8 4 3,5MH lbf*in 39,8 38,2 47,2 29,7 28,9ts2 s 174 144 144 192 186t'50 s 342 276 288 366 360t'90 s 702 546 570 750 732Vmax lbf*in/s 0,08 0,13 0,15 0,07 0,07Mechanical properties after press cure 170° C. × 20'Modulus 100% MPa 3,3 4,2 5,3 2,7 2,8Tensile strength MPa 6,9 8,2 8,6 6,5 6,5Elongation at break % 262 215 190 280 310Hardness Shore A points 55 59 64 53 59Mechanical properties after post cure 180° C. × 24 hModulus 100% MPa 3,3 3,7 5,4 2,9 2,8Tensile strength MPa 6,9 7,8 8,3 6,6 6,4Elongation at break % 264 257 188 278 309Hardness Shore A points 57 60 66 56 62Compression setO-ring 175°/70 h % 45 42 38 44 41__________________________________________________________________________ (1) 2,5dimethyl-2,5-di(terbutylperoxy)hexane 45% by weight on inert support (marketed by Atochem, Inc.) (2) Triallylisocianurate 75% by weight in inert support (marketed by Arwick)
TABLE 3__________________________________________________________________________Examples 6 7 8 9 10 11 12 13*__________________________________________________________________________FormulationHydrogenated rubber D weight % 70 70 70 50 70 70 70 /Fluoroelastomer A weight % 30 30 30 50 / / 30 100Fluoroelastomer B weight % / / / / 30 30 / /Luperco ® 101 XL (1) phr 4 6 5 4 4 6 6 6TAIC ® drymix (2) phr 3 4 3,5 3 3 4 44 4ZnO phr 4 4 4 4 6 4 4 4Naugard ® 445 phr 0,8 0,8 0,8 0,8 0,8 0,8 0,8 /Carbon black SRF (N772) phr 40 50 / 40 40 50 50 40Carbon black HAF (N326) phr / / 30 / / / / /ODR at 177° C., arc 30, 24 min.ML lbf*in 4,9 4,4 4,3 4,8 2,9 3,8 5,1 10,9MH lbf*in 25,3 46,9 32,9 43,3 23,9 39,6 45,3 20ts2 s 186 132 174 132 16B 138 132 108t'50 s 324 258 312 252 300 258 252 132t'90 s 642 480 612 480 582 492 492 222Vmax lbf*in/s 0,07 0,18 0,10 0,16 0,07 0,15 0,17 0,11__________________________________________________________________________Mechanical properties after press cure 170 ° C. × 20'Modulus 100% MPa 1,8 5,6 2,5 4,5 1,9 5,0 5,6 /Tensile strength MPa 7,0 8,6 7,8 6,0 6,1 7,2 8,9 /Elongation at break % 347 157 264 225 224 137 170 /Hardness Shore A points 47 63 55 63 42 57 63 /Compression setO-ring 1750/70h % / 44 46 52 / 43 / /Mechanical properties after post cure 180° C. × 24 hModulus 100% MPa 2,0 4,9 2,3 / / 4,4 5,4 /Tensile strength MPa 6,4 8,0 7,1 / / 6,0 8,5 /Elongation at break % 330 180 304 / / 132 197 /Hardness Shore A points 48 63 55 / / 57 64 /Cornpression setO-ring 175°/70 h % 40 43 44 / / 36 44 /Thermal ageing 175° C. × 70 hModulus 100% MPa 1,9 / / / / / / /Tensile strength MPa 6,0 / / / / / / /Elongation at break % 363 / / / / / / /Hardness Shore A points 50 / / / / / / /__________________________________________________________________________ *Comparative Example; (1) and (2) see Table 2 *Comparative Example
TABLE 4______________________________________Examples 14* 15______________________________________FormulationHydrogenated rubber D weight % 100 70Fluoroelastomer A " / 30Luperco ® 101 XL phr 6 6TAIC ® drymix " 4 4ZnO " 4 4Naugard ® 445 " 0,8 0,8Carbon black SRF (N 772) " 50 50ODR at 177° C., arc 3°, 24 min.ML lbf*in 4,8 5,6MH lbf*in 31,2 48,2ts2 s 168 150t'50 s 300 276t'90 s 588 516Vmax lbf*in/s 0,09 0,17Mechanical properties after press cure 170° C. × 20'Modulus 100% MPa 2,5 5,3Tensile strength MPa 6,4 8,8Elongation at break % 170 175Hardness Shore A points 41 61Compression set % 42 49O-ring 175°/70 hMechanical properties after post cure 180° C. × 24 hModulus 100% MPa 2,3 5,2Tensile strength MPa 5,9 8,6Elongation at break % 183 216Hardness Shore A points 38 62Compression set % 30 42O-ring 175°/70 h______________________________________ *Comparative example
TABLE 5______________________________________Thermal and chemical resistance data for the examples 14*and 15 post-cured at 180° C. × 24 h.Examples 14* 15______________________________________Thermal ageing 210° C. × 38 hModulus 100% change % / /Tensile strength change % -53 -2Elongation at break change % -49 -48Hardness Shore A change points +6 +9Weight change % -2,6 -2,2ASTM #3 150° C./70 hModulus 100% change % +16 -4Tensile strength change % -40 -22Elongation at break change % -36 -38Hardness Shore A change points -4 -6Volume change % +32 +22Fuel C 23° C./70 hModulus 100% change % / /Tensile strength change % -87 -83Elongation at break change % -88 -87Hardness Shore A change points -24 -15Volume change % +181 +125______________________________________ *Comparative example
TABLE 6______________________________________Example 16______________________________________FormulationHydrogenated rubber F weight % 70Fluoroelastomer A " 30Luperco ® 101 XL (1) phr 5TAIC ® drymix (2) " 5ZnO " 4Naugard ® 445 " 0.8Carbon black SRF (N772) " 50Armid-O ® " 1ODR at 177° C., arc 3°, 24 min.ML lbf*in 3.1MH " 47ts2 s 138t'50 " 276t'90 " 558Vmax lbf*in/s 0.17Mechanical properties after post cure180° C. × 8 hModulus 100% MPa 5.3Tensile strength " 8.8Elongation at break % 229Hardness Shore A points 68Compression set % 46O-ring 175°/70 h______________________________________ (1) and (2) see Table 2
TABLE 7______________________________________Thermal and chemical resistance data for the example 16post-cured at 180° C. × 8 h.Examples 16______________________________________Thermal ageing 200° C. × 70 hModulus 100% change % /Tensile strength change % +10Elongation at break change % -61Hardness Shore A change points +11Weight change % -2.4ASTM #3 150° C./70 hModulus 100% change % /Tensile strength change % -15Elongation at break change % -34Hardness Shore A change points +8Volume change % +19______________________________________
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Compounds comprising a peroxide and a peroxide curable blend essentially consisting of hydrocarbon elastomers containing at least an acrylic monomer and of fluorinated VDF-based elastomers having in the polymer chain at least 5% by moles of hydrogenated groups C 1 of the type ##STR1## --CH 2 -- and/or --CH 3 , the amount of fluorinated rubber in the elastomeric blend being comprised from 5 to 75% by weight, said elastomers of the blend not containing iodine and/or bromine.
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BACKGROUND OF THE INVENTION
[0001] 1. Technical Field
[0002] The present invention relates generally to augering systems which remove coal from seams within a hill by boring long horizontally extending holes into the coal seam using an auger comprising a rotary cutting head and a string of auger flights to convey the cut coal from the coal seam, and more particularly to auger flight supports for reducing boring friction to extend the distance the auger system can bore into the hill.
[0003] 2. Background Information
[0004] Augering machines powered by internal combustion engines have been used for mining coal from hills containing a coal seam for many years. These augering machines utilize an auger having a cutting head which is advanced horizontally into the coal seam. The auger is usually made up of a series of sections or auger flights having a helically wound flighting, which removably couple together end-to-end to convey the cut coal from the cutting head to a point of discharge outside the hill. The auger flights are rotationally and axially coupled by having a socket at one end and a mating shank on the opposite end. The shank of one auger flight fits into the socket of the next auger flight. A slidable latch pin extends transversely through a hole in the auger flight and into a hole in the shank of the auger flight to be coupled thereto. A release lever permits uncoupling of the auger flights such as when the cutting head is being withdrawn from the bored hole at the completion of the boring. As the string of auger flights is withdrawn, the auger flights are sequentially removed from the auger string by uncoupling and lifting the rearmost auger flight from the auger machine. Pairs of side-by-side cutting heads and augers have been used recently to form a pair of parallel holes in the coal seam to remove a larger volume of coal at once. Each auger is powered by an auger machine which applies axial as well as rotational forces to the augers to force the augers and the cutting heads into the coal seam and to rotate the cutting heads breaking away the material which the augers then convey out of the hole.
[0005] There is considerable friction developed between the flighting of the auger flights and the bored holes which requires considerable power from the augering machine, and which reduces the power available to the cutting heads and to convey the cut coal. Attempts have been made to reduce such frictional power losses in auger systems. For example, in U.S. Pat. No. 3,036,821 issued to H. D. Letts is disclosed a spider device where bearings are attached between each of the linearly extending augers, and a plurality of legs are attached to the bearings to form a “spider”. The spider somewhat supports the flighting on the bottom of the bored hole so that the flighting does not rub the ground as hard when rotating, thus reducing the power requirements of the auger machine. In U.S. Pat. No. 5,685,382 issued to Deeter is disclosed a similar auger support having a plurality of radially extending support legs affixed a bearing housing surrounding a bearing. The drive shank of an auger flight is rotatably supported by the bearing at one end of an auger flight, independently of the support provided by the auger flighting, to reduce wear and tear of the flighting and to reduce frictional drag of the auger flights. Finally, in U.S. Pat. No. Re 24,503 to C. E. Compton, which was originally U.S. Pat. No. 2,751,203 is disclosed a spider-type support system for an auger mining system. All of these devices, however, fail to solve a number of problems associated therewith.
[0006] There is thus, a continuing need for a support device which overcomes a number of problems associated with the prior art.
SUMMARY OF INVENTION
[0007] One of the advantages of the present invention is that it provides reduced frictional losses between the flighting and the bottom of the bored holes resulting in less power required to bore a given length hole.
[0008] A further advantage of the present invention is that it permits longer holes to be bored using the same augering machine due to the reduced friction.
[0009] A still further advantage of the present invention is that it is used for dual auger boring.
[0010] These and other advantages of the present invention may be realized by reference to the remaining portions of the specification, claims, and abstract.
BRIEF SUMMARY OF THE INVENTION
[0011] The present invention relates to an auger flight support for unitizing and supporting pairs of auger flights by connecting together respective first ends of each pair of parallel tubular auger flights. The auger flights each include a respective helical flighting affixed exteriorly therearound having a respective outer diameter, and include respective second ends having a drive socket. The unitized auger flights are adapted for use with an augering apparatus of the type used for rotating and advancing a pair of side-by-side cutting heads of a drilling section. The drilling section is driven horizontally into the side of a hill with the cutting heads driven rotationally through the drive sockets by the augering apparatus. The unitized auger flights are inserted between the drilling section and the augering apparatus in a rotationally coupled end-to-end manner as drilling progresses. The auger flight support includes a pair of support posts, each having a tubular bearing housing and a radially dependent support leg. A pair of drive shafts each includes a first end adapted to closely fit within and be affixable to the first end portion of a respective flight auger, a second end portion of mating configuration to the drive sockets, and a middle bearing portion which fits within said bearing housing. At least one bearing is disposed within each of the bearing housings between the respective bearing housing and the bearing portion of the respective drive shaft which bearing rotationally supports and longitudinally retains the respective drive shaft to the respective support post. A tie bar is adapted to rigidly interconnect the support posts at such a spacing that the respective of the outer boring diameters of the flightings which are closely adjacent one another. The support legs extend generally downwardly and coplanar so as to provide support for the auger flights.
[0012] The above description sets forth, rather broadly, the more important features of the present invention so that the detailed description of the preferred embodiment that follows may be better understood and contributions of the present invention to the art may be better appreciated. There are, of course, additional features of the invention that will be described below and will form the subject matter of claims. In this respect, before explaining at least one preferred embodiment of the invention in detail, it is to be understood that the invention is not limited in its application to the details of the construction and to the arrangement of the components set forth in the following description or as illustrated in the drawings. The invention is capable of other embodiments and of being practiced and carried out in various ways. Also, it is to be understood that the phraseology and terminology employed herein are for the purpose of description and should not be regarded as limiting.
BRIEF DESCRIPTION OF THE SEVERAL VIEWS OF THE DRAWINGS
[0013] Preferred embodiments of the present invention are shown in the accompanying drawings wherein:
[0014] [0014]FIG. 1 is a vertical cross-sectional view of a hill showing an augering machine positioned adjacent the side of the hill outside the hillside during drilling horizontally into a coal seam using an illustrative embodiment of auger flights and support assemblies according to the present invention;
[0015] [0015]FIG. 2, a fragmentary exploded side elevational view of an auger flight and a support assembly;
[0016] [0016]FIG. 2A, a fragmentary side elevational view corresponding to FIG. 2, but with the auger flight and the support assembly assembled together;
[0017] [0017]FIG. 3, a lateral vertical sectional view taken on the line 3 - 3 of FIG. 2A showing a pair of auger flights connected together side-by-side using the bar;
[0018] [0018]FIG. 4, a fragmentary top plan view of the ends of the auger flights connected together using the tie bar;
[0019] [0019]FIG. 5, a fragmentary side elevational view of a pair of auger flights connected together and supported by a support assembly;
[0020] [0020]FIG. 6, a fragmentary longitudinal vertical sectional view to an enlarged scale of the auger flight and the support assembly;
[0021] [0021]FIG. 6A, a fragmentary longitudinal vertical sectional view corresponding to FIG. 6 to a further enlarged scale showing the details of the bearing assembly, and
[0022] [0022]FIG. 7, a fragmentary vertical cross-sectional view corresponding to FIG. 1 but with an additional auger flight added to increase the depth of boring.
DETAILED DESCRIPTION OF THE INVENTION
[0023] Referring to FIG. 1, there is shown a plurality of auger flight supports 20 illustrative of the invention, as used with a conventional dual auger drilling system 23 which includes an augering machine 26 that drives a plurality of unitized flight sections 29 and a unitized drilling section 32 . The drilling system 23 is used for drilling into a hill 35 that contains a generally horizontally disposed coal seam 38 , and to remove the resulting cut coal chunks 41 .
[0024] The augering machine 26 is of conventional design for providing rotational power through the flight sections 29 to the drilling section 32 . One such machine is the MC-DK Coal Recovery Auger, manufactured by the Salem Tool Company of London, Ky. The augering machine 26 includes a main frame 44 supported on a plurality of downwardly dependent legs 45 . A wheeled carriage 47 which is hydraulically driven to force the flight sections 29 and the drilling section 32 into and from the hill 35 travels longitudinally on the main frame 44 on a pair of parallel rails (not shown) of the main frame. An internal combustion engine (not shown) is mounted on the carriage 47 which drives the flight sections 29 and the drilling section 32 through a pair of power trains (not shown) each of which includes a clutch, a flexible coupling, and a shiftable transmission. The power is output through a pair of power outputs 50 and 51 . Similarly, a triple could be provided having a rotating auger above the above-described pair of augers.
[0025] Each of the unitized flight sections 29 comprises a pair of auger flights 53 each having an elongate tubular body 56 to which is affixed a respective external helical flighting 59 . Within a forward portion 62 of the tubular body 56 is affixed a socket insert (not shown) having a drive socket of square cross-sectional configuration adapted to slidably and non-rotatably fit a mating drive shank (not shown) on an axially adjacent auger flight 53 as is known in the industry. Therefore, adjacent pairs of axially aligned auger flights 53 may be rotationally interconnected and axially coupled to one another end-to-end by inserting the mating shank of one auger flight 53 into the mating socket of the axially aligned auger flight 53 to secure transmission of rotational torque and axial drilling force from one to the other. Respective rearward portions 65 of the tubular bodies 56 are held together in a spaced relationship by an auger flight support 20 as will be explained subsequently.
[0026] The drilling section 29 comprises a pair of the auger flights 53 which are journaled to an elongate T-shaped center frame 68 at a front bearing support bracket 71 thereof. A pair of boring or drilling heads 72 each includes a square shank (not shown) which fits through a pair of thrust bearings 73 in support bracket 71 . The square shanks fit into the drive socket of the tubular body 56 so as to be rotationally affixed to the respective auger flights 53 of the drilling section 29 to bore into the coal seam 38 . Therefore, the adjacent axially aligned auger flights 53 of the unitized flight section 29 may be rotationally interconnected and axially coupled to one another end-to-end by inserting a mating shank of one auger flight 53 into the mating socket of the axially adjacent auger flight 53 to secure transmission of rotational torque and axial drilling force from one to the other. The respective rear portions 65 of the tubular bodies 56 are held together in a spaced relationship by an auger flight support 20 adjacent a plow plate 74 of the center frame 68 (FIG. 1).
[0027] Referring to FIGS. 2 - 3 , auger flight supports 20 comprise a pair of drive shafts 75 , which are each supported on a support post 77 containing a bearing assembly 80 , and connected together by a tie bar 83 (FIG. 3). The drive shafts 75 include a first end portion 86 adapted to closely fit within and be affixable to the rear portion 65 of a respective tubular body 56 . A second end portion 89 of the drive shafts 75 include a square drive shank 92 of mating configuration to the drive sockets. A middle bearing portion 95 is located between the respective first and second end portions 86 and 89 . The first end portion 86 is affixed to the rear portion 65 of the tubular body 56 of a respective auger flight 53 at an annular weld 98 . The first end portion 86 includes an annular recess 101 for reducing the weight of the drive shaft 75 . Referring to FIGS. 6 - 6 A, lock pin hole 104 extends through the drive shank 92 for axially coupling the respective auger flights 53 as will be explained subsequently. The middle bearing portion 95 includes an annular bearing support surface 107 of reduced outer diameter, which abuts the first end portion 86 of the drive shaft 75 at a shoulder 110 . The bearing support surface 107 also abuts the second end portion 89 of the drive shaft 75 at a shoulder 113 of further reduced diameter. A threaded lubrication hole 116 is closable using a removable threaded plug 119 which threads thereinto.
[0028] The support posts 77 each include a tubular bearing housing 122 and a downwardly dependent support leg 125 . The bearing housing 122 includes a tube 128 having a pair of inner shoulders 131 and 134 , and a pair of outer shoulders 137 and 140 . A downwardly dependent leg mounting block 143 and a pair of laterally inwardly dependent tabs 146 extend from the tube 128 . The support leg 125 includes a pair of upright side plates 149 which extend vertically from an upwardly bent foot plate 152 . The side plates 149 are interconnected by a front plate 155 . The respective support legs 125 bolt to the respective leg mounting blocks 143 using respective bolts 158 and locknuts 161 .
[0029] The bearing assemblies 80 each include a pair of annular roller thrust bearings 164 , a pair of seals 167 , a pair of thin spacer sleeves 170 , an annular forward flange ring 173 , and an annular rear flange ring 176 . The flange ring 173 closely fits about the bearing support surface 107 of the drive shaft 75 and includes an O-ring 179 disposed in an O-ring groove 182 which seals against the shoulder 110 . The respective thrust bearings 164 closely fit about the bearing support surface 107 of the drive shaft 75 , disposed against the respective inner shoulders 131 and 134 of the tube 128 . The spacer sleeves 170 closely fit about the bearing support surface 107 of the drive shaft 75 abutting the respective thrust bearings 164 to maintain the proper spacing for the seals 167 . The seals 167 include respective mating halves 185 and 188 which are respectively pressfit within the forward flange ring 173 and the rear flange ring 176 , and against the respective outer shoulders 137 and 140 of the tube 128 . The mating halves 185 and 188 abut to seal out dirt and fluids from reaching the respective thrust bearings 164 . The flange ring 176 closely fits about the second end portion 89 at a shoulder 113 of the drive shaft 75 and includes an O-ring 192 disposed in an O-ring groove 195 which seals against the shoulder 113 .
[0030] The respective drive shafts 75 , the support posts 77 , and the bearing assemblies 80 are held together by a plurality of bolts 196 which extend through the flange ring 176 and which longitudinally thread into the shoulder 113 of the drive shaft 75 . Alternatively, the drive shaft 75 can be externally threaded at the shoulder 113 and the rear flange ring 176 internally threaded so as to threadably engage to retain the respective drive shafts 75 , the support posts 77 , and the bearing assemblies 80 . The support posts are connected together using the tie bar 83 which bolts to the respective pairs of laterally dependent tabs 146 of the bearing housings 122 . The respective auger flights are axially coupled together using a locking pin assembly 198 as is known in the industry, which includes an inwardly biased, spring loaded pin 201 which engages the lock pin hole 104 through the drive shank 92 , and a release lever 204 which is pivotally connected to the forward portion 62 of the auger flights 53 . Depressing the release lever 204 pulls the pin 201 radially outwardly against the spring biasing to permit coupling and uncoupling of axially adjacent auger flights 53 . A longitudinal frame member (not shown) which is disposed between the auger flights 53 can be bolted between the axially adjacent tie bars 33 for additional support.
[0031] Operationally, it can be seen that support post 77 , when positioned along the axially aligned coupled auger flights, will support the weight of the auger flights and the material being transmitted rearwardly along the flights toward the drilling machine. Additionally, support post 77 , by way of bearing assembly 80 , will allow for the smooth rotation of the auger flights, substantially reducing drag and friction, allowing more energy to be transmitted to drilling head 72 . In this manner, the coal may be removed from coal seam 38 within hill 35 quicker and with less energy. Additionally, a significantly longer hole may be drilled into hill 35 along coal seam 38 allowing for more coal to be removed than was otherwise possible before the use of the present invention.
[0032] Additionally, this device could be used on an auger drilling system 23 which drives three unitized flight sections without departing from the spirit of the present invention.
[0033] It can now be seen that the present invention solves many of the problems associated with the prior art. The present invention provides reduced frictional losses between the flighting and the bottom of the bored holes resulting in less power required to bore a given length hole. The present invention also allows longer holes to be bored using the same augering machine due to the reduced friction. The present invention provides for dual auger boring.
[0034] Although the description above contains many specifications, these should not be construed as limiting the scope of the invention but as merely providing illustrations of some of presently preferred embodiments of this invention. The specification, for instance, makes reference to dual auger boring. However, the present invention is not intended to be limited to use only with dual augers. Rather it is intended that the present invention can be easily adapted for use with three or more side-by-side augers by adding more pairs of tabs and additional tie bars, or even by adding augers which are vertically disposed. Thus, the scope of the invention should be determined by the appended claims and their legal equivalents rather than by the examples given.
[0035] In the foregoing description, certain terms have been used for brevity, clearness, and understanding. No unnecessary limitations are to be implied therefrom beyond the requirement of the prior art because such terms are used for descriptive purposes and are intended to be broadly construed.
[0036] Moreover, the description and illustration of the invention is an example and the invention is not limited to the exact details shown or described.
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An auger flight support for use with an augering systems for mining which bores a pair of side-by-side holes through the coal seam using respective augers. Each auger includes a drilling section which is followed by a series of auger flights for conveying the bored coal back out of the respective hole. The auger flight support includes a pair of thrust bearing and housing assemblies which are tied together and each supported by a respective leg which lowers the friction between the auger flight and the bottom of the bore. This significantly reduces the power required to rotate the augers.
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This application is a continuation, of U.S. application Ser. No. 07/725,108 filed. Jul. 3, 1991, now abandoned.
BACKGROUND OF THE INVENTION
This invention is directed to pick-up heads of the type disclosed in commonly assigned U.S. Pat. Nos. 3,512,206 and 3,545,181 in the name of Bernard W. Young issued respectively on May 19, 1970 and Dec. 8, 1970 and respectively titled AIR FLOW SURFACE CLEANING APPARATUS and AIR CLEANING APPARATUS.
The latter patents disclose a vehicle which carries a pick-up head, a centrifugal separator, a hopper, and assignee's REGENERATIVE® air circulating system. Air generated by a turbine is directed through a blast orifice of the pick-up head, admixes with and propels the debris to a suction orifice of the pick-up head after which the debris is centrifugally separated and discharged in the hopper, and the air returns to the blast orifice. In this manner debris on roads, roadways, tarmacs, parking lots or the like can be rapidly and efficiently removed. However, while the apparatus of the latter patents represented the state-of-the-art at the time of patenting and continues to do so to date, continued experimentation, research and development has resulted in yet greater efficiency and higher speeds of both debris removal and vehicle travel. Furthermore, the art of road sweepers has advanced considerably since the early 1970's and has become considerably more sophisticated and specialized. Most recently U.S. Pat. No. 4,773,121 was granted on Sep. 27, 1988 to the common assignee, and discloses an improved pick-up head of aerodynamic shape having minimum pick-up head to ground clearance so as to maximize blast air velocity. The latter assures that debris, particular small high mass debris, such as grains of sand, pebbles, pea-gravel or the like can be cleaned from surfaces, specifically and particularly airport runways, tarmacs and the like.
SUMMARY OF THE INVENTION
The present invention is directed to a pick-up head which is of an extremely simple and straightforward construction and utilizes a rotating brush to impel debris into an air stream of an air suction chamber. The broom is mounted in a broom chamber rearward of an associated air pressure chamber and its associated air pressure orifice, and the broom is rotated in a direction to impel debris from an associated surface in the same direction as air emitted from the air pressure orifice or blast orifice toward the associated air suction chamber. Because of the latter arrangement, debris which is "tacky," which may be otherwise "stuck" to the surface, or which is slightly too heavy to be moved into the suction air stream by the air emitted from the blast orifice is impelled or propelled at a relatively high entrainment velocity toward and into the air suction stream which continues the movement of this debris at a predetermined conveying velocity somewhat less than the entrainment velocity. Thus, in those cases where debris cannot be broken loose from a surface simply through the pressurized air blast issuing from the blast orifice, the broom and its direction of rotation agitate or otherwise break loose stuck or heavier debris, impel the same at a high entrainment velocity toward the air exiting the blast orifice, and the latter combined velocities assure conveyance of the debris through the suction chamber and eventual discharge into an associated hopper.
The novel pick-up head of the present invention is also constructed to allow the broom to react to anomalies of the surface along which the pick-up head is adapted to travel. The latter is accomplished by mounting each opposite end of the broom to an associated shaft which is independently pivotally mounted to a housing of the pick-up head. In this manner should the surface which is being swept have abnormally high peaks or low valleys, the broom end portion associated therewith will respectively rise and fall while the opposite end of the broom will essentially maintain its position dependent upon the surface against which it is reacting and independent of the anomalies of the surface at the broom end portion axially opposite thereto. The latter feature is augmented by utilizing an independent fluid piston/cylinder with each axially opposite end portion of the broom, and pressurizing the fluid piston/cylinder thereof in parallel from a common pressure source, such as a conventional hydraulic pump or the like. Because of this arrangement, should the surface have a high anomaly, the end portion of the broom travelling thereover tends to rise which in turn tends to increase the pressure in its associated cylinder and this in turn increases the pressure in the opposite cylinder so that both axial end portions of the broom are basically urged against the surface under the same force. The bristles of the broom end portion reacting against the higher anomalies will tend to deflect and this end portion will tend to rise, whereas the axial opposite end portion of the broom will maintain its status quo. This feature is particularly desirable when the pick-up head is moving along a road and encounters, for example, a solidified concrete truck spill which might be, for example, a foot in width, an inch or so in height, and perhaps a length of twenty feet or more. Due to the construction of the pick-up head just described, the road and those portions of the road immediately adjacent the concrete spill, as well as the top of the concrete spill itself, are cleaned in an efficient and effortless manner.
In further accordance with the present invention, the pick-up head is provided with biasing means associated with the broom to counteract the force of the fluid piston/cylinder mechanisms which normally urge the broom toward the surface being swept. The biasing means include two springs, one each independently associated with each one of the broom end portions. The biasing force of each spring is opposite in direction to that of the associated fluid piston/cylinder mechanism, and thus the fluid piston/cylinder mechanisms work against the force of the springs and the forces created by ground reaction. By adjusting the force of the springs a desired "burn pattern" of the broom upon the surface being swept can be generated and maintained at an efficient level. The adjustment of the springs also compensates for the wear of the brushes of the broom which also have an effect on the desired burn pattern.
In further accordance with the present invention, the broom is mounted for pivotal movement in its associated broom chamber between a pair of pivotally mounted arms, one of which is formed of a pair of members bolted to each other. A shaft of the broom is axially slidably connected to one of the arms and to a first member of the other arm which permits rapid assembly and disassembly of the broom relative to the arms by simply uncoupling and recoupling the pair of members. A worn broom assembly can be removed and replaced by a new broom assembly in 10 to 15 minutes, as opposed to the hour or more now required in conventional pick-up heads. Obviously, reduction in down time for broom replacement reflects an increase in travel time and attendant efficiency.
The broom is also connected at its end portion through polygonal drive connections to the opposite arms. These polygonal drive connections are essentially nonrotatable telescopic couplings which have sufficient clearance to effect parallel misalignment therebetween, i.e. the axes of the couplings are parallel to each other though not coaxially, which also compensates for anomalies of the surface along which the pick-up head is adapted to travel.
In further accordance with this invention the air pressure orifice or blast orifice is defined in part by a relatively elongated plate which is yieldably mounted relative to the housing and can deflect about its neutral axis. A plurality of screws spaced from each other along the elongated plate apply the force to create such deflection which in turn allows the blast orifice to vary in size and shape from a generally rectangular configuration to a tapered configuration normally converging from the suction side toward the pressure side of the pick-up head. This allows the air emitted from the blast orifice to vary along the length thereof to accommodate specific and varied debris conditions.
The pick-up head of the present invention is also associated with a fluid circuit system including a fluid motor for rotating the brush and two fluid piston/cylinder mechanisms, each independently associated with one of the broom end portions. The fluid circuit includes a line for directing pressurized hydraulic fluid to an inlet of the motor and from an outlet of the motor to inlets of the cylinders in a direction urging the broom toward the surface which is to be cleaned and also to a pressure relief valve which can be set at a predetermined pressure. Outlets from the cylinders are in turn connected to each other and to a return to a reservoir. In this manner pressurized fluid, preferably hydraulic fluid, is introduced first into the motor and then through a T-fitting to the pressure relief valve and into the parallel connected cylinders of the fluid piston/cylinder mechanisms which assures that the broom is rotated before it contacts the ground thereby decreasing undesired back pressure. Since the outlet of the fluid motor is connected directly to the inlet of the cylinders for effecting down pressure of the broom against the surface which is being swept, the anomalies of the surface heretofore noted which tend to raise the broom can create undesirably high back pressure forces which can be relieved by the pressure relief valve. Thus, increased broom pressure caused by ground reaction forces is immediately relieved when the relief valve pressure is reached thereby preventing the broom from digging into the surface, thus preventing broom/bristle damage, preventing motor burnout, etc.
With the above and other objects in view that will hereinafter appear, the nature of the invention will be more clearly understood by reference to the following detailed description, the appended claims and the several views illustrated in the accompanying drawings.
BRIEF DESCRIPTION OF THE DRAWINGS
FIG. 1 is a perspective view of a pick-up head of this invention, and illustrates front, top and side walls thereof and a pressurized air inlet and a suction air outlet associated with the top wall.
FIG. 2 is a fragmentary side elevational view of a sweeper carrying the pick-up head, and illustrates a suction chamber, a broom chamber and a broom in the broom chamber of the pick-up head.
FIG. 3 is a cross-sectional view taken generally along line 3--3 of FIG. 1, and illustrates an arm pivotally mounting one end of the broom adjacent the pressure inlet, an air pressure chamber, a blast orifice associated with the air pressure chamber, and a yieldably mounted elongated plate which can be deflected along its neutral axis to vary the shape and/or size of the blast orifice.
FIG. 4 is a cross-sectional view taken generally along 4--4 of FIG. 1, and illustrates structure similar to that shown in FIG. 3 adjacent the suction outlet of the pick-up head.
FIG. 5 is a cross-sectional view taken generally along line 5--5 of FIG. 1, and illustrates the broom in generally spanning relationship between side arms of the pick-up head, end portions of the broom connected to pivotally mounted arms, and a fluid motor carried by one of the arms for rotating the broom.
FIG. 6 is a fragmentary side elevational view looking from right-to-left in FIG. 5, and illustrates the arm pivotally mounting an end portion of the broom at the suction side of the pick-up head.
FIG. 7 is an exploded view of a portion of the pick-up head of FIG. 1, and illustrates details of the pivotal mounting of the broom relative to the pick-up head and the yieldable mounting of the deflectable plate for changing the size/shape of the blast orifice.
FIG. 8 is an enlarged perspective view of the associated encircled portion of FIG. 7, and illustrates the details of the mounting of the fluid motor to an arm of the pivotal mounting mechanism and through a drive connection to one end portion of the broom.
FIG. 9 is an enlarged exploded view of the associated encircled portion of FIG. 7, and illustrates the details of the manner in which an opposite end of the broom is axially connected to a pivoted arm adjacent the suction end of the pick-up head.
FIG. 10 is an enlarged exploded fragmentary assembly view of the arms, motor and shaft of the broom, and illustrates the manner in which the motor is connected to the arm, is drivably connected to one end of the shaft, and an opposite end of the shaft is connected to the adjacent arm.
FIG. 11 is an enlarged fragmentary view of the associated encircled portion of FIG. 7, and illustrates details of a plurality of yieldable connections for the deflectable plate which varies the size/shape of the blast orifice.
FIG. 12 is a schematic hydraulic circuit and illustrates a fluidic control system for operating a motor and fluid piston/cylinder mechanisms associated with the broom.
DESCRIPTION OF THE PREFERRED EMBODIMENT
A novel high speed pick-up head of this invention is generally designated by the reference numeral 10 (FIGS. 1 through 6), and is illustrated in FIG. 2 connected to a sweeper or truck sweeper 15 which includes a hopper 16 carried by a frame 17 which is moved along a surface S in a conventional manner upon the rotation of wheels 18 (only one of which is illustrated). The direction of movement of the sweeper 15 in FIG. 2 is right-to-left. Forwardly of the pick-head 10 is a gutter brush 20 located one each behind the front wheels (not shown) which are constructed and arranged for operation in the manner described in the earlier identified patents in the name of Bernard W. Young. A deflector plate 21 (FIGS. 1 and 2) is conventionally supported between the gutter brushes (20 and unillustrated).
The pick-up head 10 is conventionally supported for vertical up and down movement between the gutter brushes (20 and unillustrated) and the wheels (18 and unillustrated) by pivot rods 22, 23 (FIGS. 1 and 2), each having one end pivotally connected to the frame 17 and an opposite end connected to a bracket 32, 24, respectively (FIG. 1) welded to a top wall 25 of the pick-up head 10. A pair of cylinders 26, 26 (FIGS. 1 and 12) is each pivotally connected by a pivot 27 to a bracket 28 (FIG. 2) which is bolted to the frame 17. A piston rod 30 of each cylinder 26 is connected to a chain 31 which is in turn connected to one of the associated brackets 32, 24 (FIGS. 1 and 2) welded to the top wall 25 of the pick-up head 10. Movement of the rods 30 appropriately raises and lowers the pick-up head 10 relative to the surface S and the debris (not shown) thereupon which is removed in a manner to be described more fully hereinafter.
An air pressure inlet 34 (FIGS. 1 and 3) and an air suction outlet 35 (FIGS. 1 and 4) are in fluid communication through the top wall 25 with a respective air pressure chamber 40 and an air suction chamber 45 separated from each other generally by a plate 41 which is welded at one end (unnumbered) to the top wall 25 (FIG. 3) and is welded to a square tube 42 at its opposite end. The square tube 42 and side edges (unnumbered) of the plate 41 are welded to side walls 43, 44, each having a generally identical downwardly opening rectangular cut-out or slot 46 (FIGS. 3 through 7). The square tube 42 defines an air pressure orifice or blast orifice 60 with a blast orifice curtain or skirt 61 (FIGS. 3, 4 and 7) which is connected by a plurality of nuts and bolts 62 and an apertured plate 63 (FIG. 7) to a plate 64 (FIGS. 3 and depending downwardly from the top wall 25. The skirt 61 spans the distance between the side walls 43, 44 and is constructed from relatively flexible material.
As is described in the first two-mentioned patents, pressurized air entering the pressure inlet 34 through an associated flexible tube 66 (FIG. 2) in a downward direction, as indicated by the unnumbered headed arrows associated therewith in FIG. 2, flows lengthwise along the air pressure chamber 40 between the side walls 43, 44 and exits the blast orifice 60 along the length thereof in the manner indicated by the unnumbered headed arrows in FIG. 3. The pressurized air exiting the blast orifice 60 is directed generally forwardly or in the direction of vehicle travel which in FIGS. 3 and 4 is from right-to-left. Thus, any debris on the surface S is agitated, loosened and entrained at a predetermined entrainment velocity and propelled thereby into the air stream flowing in the suction chamber 45 from left-to-right, as viewed in FIG. 1, as air is drawn outwardly from the pick-up head 10 through the air suction outlet 35 and conducted by an associated flexible tube 67 (FIG. 4) to the hopper (not shown) of the sweeper 15. Under normal conditions, the high entrainment velocity of the pressurized air exiting the blast orifice 60 is sufficient to clean the surface S of debris, but in some cases debris is stuck to the surface S and will not break loose under air pressure and must be agitated or brushed therefrom.
Accordingly, in further accordance with this invention, the pick-up head 10 is provided with a broom chamber 70 defined between the top wall 25, the side walls 43, 44 (FIG. 5), the skirt 61 (FIGS. 3 and 4) and a rear wall 69. Broom means 71 in the form of a broom is housed within the broom chamber 70, and is defined by a plurality of bristles 72 projecting radially outwardly from and continuously along the length of a hollow tubular shaft 73 having opposite first and second end portions 74, 75, respectively (FIG. 5). The shaft end portions (74, 75) each internally receive a respective fitting 76, 77 (FIG. 10) which is welded to the shaft 73. The fittings 76, 77 include respective polygonal, substantially square, openings 78, 79. The openings 78, 79 are connected to and in part defined journals for effecting rotation of the broom 71 clockwise, as viewed in FIGS. 3 and 4, in a manner to be described more fully hereinafter.
The shaft 73 is not only mounted for rotation at each of its opposite end portions 74, 75, but is also mounted for axial assembly and disassembly relative to respective arms 84, 85 which are in turn part of respective independent broom pivotal mounting mechanisms 94, 95, respectively (FIG. 7).
The arm 85 (FIGS. 5, 7 and 10) include an end portion 86 welded to a shaft 87 and an opposite end portion 88 carrying an internally threaded nut 91. The internally threaded nut 91 is received in an opening (unnumbered) of the end portion 88 of the arm 85 and is appropriately welded thereto. The nut 91 includes a cylindrical shoulder 92 which is received in a counterbore 93 of a cylindrical spindle 96 having a medial bore 97 and another counter bore 98. A threaded bolt 100 is passed through a washer 101 and the spindle 96 and is threaded into the threaded nut 91 with the shoulder 92 thereof received in the counterbore 93. Cylindrical brass bearings 102,103 having interior Teflon surfaces are slipped over the spindle 96. A hub 104 of a generally tubular configuration includes an internal cylindrical surface 105 corresponding in size to the exterior of the bearings or bushings 102, 103. An exterior surface 106 of the hub 104 is of a polygonal, preferably square, configuration generally matching the polygonal/square configuration of the opening or aperture 79 of the fitting 77. Thus, the rectangular opening 79 of the shaft end portion 75 can be axially slipped upon and axially removed from the like square matching configuration of the outer surface 106 of the hub 104. The fit between the square surfaces 79, 106 is relatively loose allowing radial play which allows parallel misalignment during operation when the broom 71 encounters anomalies along the surface S during operation, as will be described more fully hereinafter.
The end portion 74 of the shaft 73 is connected to a drive shaft 107 of a fluid (hydraulic) motor M (FIG. 10) which is removably secured to a first member 108 of the arm 84. The first member 108 is in turn secured to a second member 110 of the arm 84. The securement of the members 108, 110 to each other is through threaded bolts 111 and washers 112 (FIG. 8). The bolts 111 pass through openings 119 in the member 108 and are threaded into aligned threaded openings 115 in the member 110.
The motor M has a mounting flange 116 provided with four threaded bores 117 (FIG. 10) which are aligned with four openings 118 in the member 108. A bolt 120 associated with a washer 121 is passed through each of the openings 118 and is threaded into an associated one of the threaded bores 117 to rigidly secure the motor M to the member 108 of the arm 84 with the shaft 107 projecting through an enlarged opening 122 (FIG. 8) of the member 108.
A washer 123 is slipped over the shaft 107 and against the right-hand face (unnumbered), as viewed in FIGS. 8 and 10, of the member 108. A key 124 is slipped into a slot 125 of the drive shaft 107 and a drive hub 126 is slipped on the shaft 107. The hub 126 has an axial keyway 127 which registers with the key 124 to lock the hub 126 nonrotatably fixed to the drive shaft 107. A lock nut 128 is threaded upon a threaded end portion 130 of the shaft 107 and is locked in position by a cotter pin 131. An exterior surface 132 of the hub 126 is polygonal, preferably square, and in loose matching configuration to the square configuration of the opening 78 of the fitting 76 (FIG. 10) of the shaft end portion 74. Thus, the hub 126 can be axially slid into and out of the square opening 78 just as the hub 104 can be axially slid into and out of the square opening 79 of the fitting 77 of the shaft end portion 75. The latter connections effect parallel misalignment between the axes of the hubs 104,126 and the axes of the openings 78, 79, respectively. The aforementioned radial play between the hubs 104, 126 and the openings 78, 79, respectively, can, for example, permit the broom shaft 73 to shift such that its axis and that of the openings 78, 79 are parallel to but radially offset from (misaligned) the axis between the hubs 104, 126. Similarly, the aforementioned radial play between the hubs 104, 126 and the openings 78, 79, respectively, can, for example, permit angular misalignment between each axis (unnumbered) of the spindles 96, 107 and the associated axes of the openings 79, 78, respectively.
The member 110 of the arm 84 (FIG. 8) is welded to a shaft 107 of the pivoting mounting mechanism 94.
As is best illustrated in FIGS. 1 through 6 of the drawings, each of the side walls 43, 44 is exteriorly covered by a skid plate 113, 114, respectively. The skid plates 113,114 carry respective skids 115, 116 which are constructed from hardened metal and might include carbide inserts to decrease wear and increase the life thereof as the same move along the surface S. The skid plates 113, 114 are conventionally bolted by bolts 116 to the side plates 43, 44 after passing through adjusting slots 117 (FIG. 6). As is best illustrated in FIGS. 5 and 6, the skid plates 113,114 cover the cut-outs or slots 46 of the respective side walls 43, 44. However, the bolts 116 need but be removed to gain access to the axially opposite end portions 74, 75 of the shaft 73 through the slots 44 should it be desired to at any time assemble, disassemble and/or replace the broom 71. For example, assuming that the skid plates 113, 114 have been removed by first removing the bolts 116, the broom 71 is readily removed by simply removing the bolts 111 (FIG. 8) from the nuts 113 through the access slot 46 (See FIG. 7). The motor M remains fastened to the arm 108, but the arm 108 can now be pulled to the left, and as viewed in FIGS. 5 and 7, toward, into and through the cut-out or slot 46. During this leftward movement, the hub 126 is pulled out of the openings 78 which releases or frees the left end portion 74 of the broom 71 (See FIG. 10). The entire broom 71 can then be pulled to the left causing the end portion 75 and specifically the fitting 77 thereof to be slid to the left and removed from the hub at 104. Thus, the broom 71 is removed by simply removing three bolts 111, shifting the motor M while it remains assembled to the arm 108 to the left, and shifting the broom shaft 73/broom 71 to the left, activity which can all be accomplished by one person operating from the left-hand side from the pick-up head 10, as viewed in FIG. 5, with the pick-up head 10 simply being in its elevated position. Once the broom 71 has been removed, it can, for example, be switched end-for-end if worn improperly. For example, the broom bristles 72 might be so worn as to impart a tapered configuration to the broom 71 which if shifted end-for-end would still allow the broom 71 to be used for a considerable length of time in an efficient manner. Alternatively, the broom 71 can be removed and a new broom reassembled by the reversal of the operation just described. However, in keeping with this invention, it is also preferable to remove the hub 104 and the two bushings 102, 103 from the spindle 96 which, as viewed in FIGS. 9 and 10, is achieved by simply pulling the hub 104 and the bushings 102, 103 to the left to remove the same from the spindle. The hub 104 and the bushings 102, 103 would be replaced by new bushings and hubs slipped upon the spindle 96 (or into the broom shaft 73) by left-to-right movement, as viewed in FIG. 10. A new broom would then be assembled by axially sliding the fitting 77 of the end portion 75 upon the new hub 104 and slipping the or a new hub 126 into the opening 78 after which the member 108 is rebolted to the member 110 of the arm 84 by the bolts 111. If desired, the hub 126 can also be removed at any time after the member 108 has been disassembled from the member 110 and replaced by a new hub 126, should such be desired. However, it is important to note that the assembly and disassembly just described can be accomplished by only one person in ten to fifteen minutes time by simply removing and replacing the three bolts 111 and the associated washers 112.
Obviously, once reassembly has taken place as described, the skid plates 113, 114 can be rapidly bolted in adjusted position relative to the respective side walls 43, 44 by the nuts 117 (FIG. 6).
Reference is particularly made to FIGS. 1, 3, 6, 7 and 8 which collectively illustrate the manner in which the pivotal mounting mechanisms 94, 95 (FIG. 7) independently urge the respective opposite end portions 74, 75 of the broom shaft 73, and thus the entire broom 71 itself in a generally downward direction toward the surface S whereupon the opposite ends of the broom can independently react to anomalies of the surface S during a sweeping operation.
The pivotal mounting mechanisms 94, 95 each include the respective shafts 107, 87, heretofore described, which are rigidly secured by welding to the member 110 of the arm 84 and the arm 85, respectively (FIG. 7). The shafts 107, 87 carry respective additional arms or members 132, 133 and 134, 135. The arms 132, 133 are welded to the shaft 107 while the arms 134, 135 are welded to the shaft 87. Two pairs of split bearing blocks 136, 137 and 138, 139 rotatably embrace the respective shafts 107, 87 and are secured to the top wall 25 of the pick-up head 10 by pairs of threaded bolts 140 (FIGS. 3 and 7). The split bearing blocks 136 through 139 thereby pivotally mount the shafts 107, 87, respectively, with their axes in alignment and generally parallel to the axis (unnumbered) of the broom shaft 73. Since the shafts 87, 107 are not united in any fashion, it is to be particularly noted that the pivotal mounting mechanism or means 94 is associated with the end portion 74 of the shaft 73 totally independently of the pivotal mounting mechanism or means 95 which is likewise associated with the end portion 75 of the shaft 73 totally independently of the pivotal mounting mechanism or means 94.
Independent fluid piston/cylinder mechanisms or means 144,145 (FIG. 1) are associated with the respective pivotal mounting mechanisms or means 94, 95. The mechanisms 144, 145 include respective cylinders 146, 147 and piston rods 148,149 which are in turn pivotally connected through respective bifurcated brackets 150, 151 to the respective arms 133, 135 which project upwardly beyond the top wall 25. The cylinders 146, 147 are also pivotally connected to identical bifurcated brackets 159 which are welded to the top wall 25. The cylinders 146, 147 are part of a hydraulic circuit system 150 (FIG. 12) which also includes the motor M for rotating the brush 71. The cylinders 146, 147 include inlet lines or ports 151, 152, and outlet lines or drain ports 153, 154, respectively. When fluid, such as oil under pressure, is introduced into the lines 151, 152, the piston rods 148, 149 are extended outwardly of the cylinders 146,147, respectively, causing the arms 133, 135 to rock or pivot to the right, as viewed in FIGS. 1, 3 and 7, which causes clockwise rotation of the shafts 107, 87, as viewed in these figures. The latter clockwise rotation causes the arms 84, 85 to likewise pivot clockwise moving the brush 71 downwardly and forcefully against the surface S. Obviously, during the latter defined movement of the rods 148, 149, the fluid exhausts the cylinders 146,147 over the respective lines 153,154, as will be described more fully hereinafter. Just as obvious is the fact that fluid introduced through the lines 153, 154 and vented through the lines 151, 152 will result in the retraction of the rods 148, 149, respectively, and the counterclockwise rotation of the shafts 107, 87, the arms 133, 135, the arms 84, 85 and the broom 71 carried by the latter.
Means 164, 165 (FIG. 7) are independently associated with each of the pivotal mounting means or mechanisms 94, 95 and continuously apply spring-biasing forces tending to urge or pivot the shafts 107, 87 and the arms 84, 85 thereof in a counterclockwise direction, again as viewed in FIGS. 3 and 7, thus likewise continuously tending to urge the broom 71 away from the surface S. The means 164, 165 are in each case a tension spring having one end connected to the respective arms 132, 134 and an opposite end connected to a respective threaded bolt 166 which in turn passes through an aperture (unnumbered) of a bracket 169 (FIG. 1) welded to the top wall 25 of the pick-up head 10. A washer 167 and an associated nut 168 is threaded to each of the bolts 166 to draw the bolts 166 to the left, as viewed in FIG. 1 and 7, for increasing the tension of the springs 164, 165 or vice versa. Accordingly, the fluidic force of the piston/cylinder mechanisms 144, 145 when operated in a direction to urge the broom 71 toward the surface S is counteracted by the opposite forces of the springs 164, 165 to effect counterbalancing of broom movement and augment the parallel misalignment function as the broom 71 travels over anomalies of the surface S.
The blast orifice 60 (FIGS. 3 and 4) is also preferably selectively adjustable in size and shape by means 170 (FIGS. 3, 4, 7 and 11). The blast orifice size and shape altering means 170 is defined by a relatively elongated metallic deflectable plate or member 171 which essentially spans the distance between the side walls 43, 44. The elongated member or plate 171 has a neutral axis generally designated by the reference numeral 172 (FIG. 11) and located thereat are five elongated slots 173. Only one slot 173 is illustrated in FIG. 11, but the five slots 173 are located generally equally spaced from each other. The plate 171 includes an upper end portion 174 having a terminal edge 175 bent rearwardly for reinforcing purposes. A lower end portion 176 of the plate 171 is bent forwardly and thereafter a terminal end 176 is bent downwardly and forwardly. The lower terminal end 177 along its entire length between the side walls 43, 44 bears against the curtain 61 (FIGS. 3 and 4) and holds the curtain 61 in a desired orientation and in selected spaced relationship from the tube 42 to establish the size and configuration of the blast orifice 60. A broom wipe curtain 180 constructed of flexible material is connected to the lower generally horizontal end portion 176 by a plate 181 and a plurality of fastening means 182 passing through associated openings in the plate 181 and the broom wiper curtain 180. A free terminal edge (unnumbered) of the broom wiper curtain 180 is positioned to lightly contact the bristles 72 of the brush 71 during rotation of the latter, in the manner best illustrated in FIGS. 3 and 4 to continuously clean and remove debris therefrom.
Means generally designated by the reference numeral 185 (FIG. 11) are associated with each of the slots 173 for resiliently mounting the elongated plate 171 within the pick-up head 10 and specifically within the broom chamber 70 (FIGS. 3 and 4). Each of the resilient mounting means 185 includes a blast orifice hanger bracket 186 of a generally L-shaped configuration having a pair of legs (unnumbered). One leg of each hanger bracket 186 is secured by a pair of nuts and bolts 187 to a projecting portion (unnumbered) of the plate 63 (FIGS. 3 and 4). Another leg (unnumbered) of the bracket 186 has an opening 188 through which passes a threaded bolt 190. A nut 191 is threaded upon the threaded bolt 190 and rigidly secures the threaded bolt 190 to the hanger bracket 186. A relatively thick cylindrical resilient rubber grommet 192 is slipped on each bolt 190 after which each bolt 190 is passed through one of slots 173. Thereafter another resilient thick rubber grommet 193 is slipped on each bolt 190 followed by a washer 194 and a nut 195. In this fashion the resilient mounting means 185 resiliently mount the elongated plate 171 at five points along its length and, of course, along its neutral axis 172.
Means 200 (FIGS. 3 and 4) are associated with each of the resilient mounting means 185, and each of the means 200 includes a bolt 201 threaded in a jamming nut 202 and a second nut 203 which is welded to an upstanding plate portion 204 of the top wall 25 (FIGS. 3 and 4). A terminal end (unnumbered) of each bolt 201 bears against the upper end portion 174 of the elongated plate 171. When the jamming nuts 202 are backed-off (unthreaded to the left in FIGS. 3 and 4) their respective threaded bolts 201 can be threaded to the right or to the left, as viewed in FIGS. 3 and 4. If the three bolts 201 are threaded an equal distance to the right, the top end portion 174 of the elongated plate 171 will be moved to the right and the blast orifice curtain 61 will be moved to the left, as viewed in FIGS. 3 and 4, causing the entire elongated plate 171 to pivot about its neutral axis 172 which in turn causes the lower terminal end 177 of the elongated plate 171 to move an approximate equal distance toward the square tube 42 thereby reducing the size of the blast orifice 60. If each of the bolts 201 is unthreaded an approximate equal amount by movement to the left, again as viewed in FIGS. 3 and 4, the converse occurs and the size of the blast orifice 60 is increased. It should be noted that if the bolts 201 are approximately equally moved to the right or to the left, again as viewed in FIG. 4, the entire bottom terminal edge 177 of the plate 171 and the blast orifice curtain 61 will likewise move approximately equally toward or away from the tube 42. Thus, if the blast orifice 60 were of a rectangular configuration, as viewed from above or below, the adjustment just defined would maintain this rectangular or polygonal configuration and would merely change the size (width) thereof. However, at times it is desirable to alter the square or polygonal configuration of the blast orifice 60 such that, for example, the blast orifice 60 converges in size from the suction outlet 35 toward the pressure inlet 34. In order to accomplish the latter, the three bolts 201 are threaded or unthreaded different relative distances. For example, the centrally located bolt 201 can be threaded a predetermined distance further into the broom chamber 70, the bolt 201 nearest the pressure inlet 34 (FIG. 3) is threaded the greatest distance into the brush chamber 70 and the bolt 201 nearest the suction outlet 35 (FIG. 4) is threaded the least distance into the brush chamber 70. Thus, the three bolts are threaded different distances into the brush chamber resulting in the elongated plate deflecting or bending relative to its neutral axis 172 as opposed to purely pivoting thereabout, as would occur if the bolts 201 were moved equal distances into or out of the broom chamber 70. In addition to the elongated plate 171 deflecting about its neutral axis, the grommets 192, 193 will yield or compress to augment the latter-described deflection. In this fashion, the blast orifice 60 will be at its maximum width adjacent the suction outlet 35 and at its minimum width adjacent the pressure inlet 34. In this case the blast orifice curtain 61 is not parallel to the square tube 42 but instead tapers uniformly relative thereto to impart the overall tapering configuration to the blast orifice 60.
Reference is again made to the hydraulic circuit system 150 of FIG. 12 which additionally includes a switch 201 having an "ON" terminal 202 connected by a line 203 to a "C" terminal 204 of a pressure switch 205 having a switch arm 206 movable between an "NC" terminal 207 and a "NO" terminal 208. The terminal 207 is connected by a line 210 to an indicator light or lamp 211 to ground and by another line 212 to a solenoid (unnumbered) of a valve 215. The switch arm 206 of the pressure switch 205 is connected by a fluid line 216 to a line 217 divided into branch lines 218, 220 connected to the rod ends (unnumbered) of the cylinders 26 (FIGS. 1 and 12) of the pick-up head 10.
When the switch 201 is moved to the "ON" position, terminal 202 delivers voltage over the line 203 to the terminal 204. If the pick-up head 10 is in its raised position with the rods 30 retracted and the rod ends pressurized, the switch arm 206 of the pressure switch 205 is switched by the high pressure in the rod end of the cylinders 26 over the lines 217, 218 and 220 to the "NO" terminal 208 and power will not flow over the lines 210 or 212 which will neither light the indicator lamp 211 or energize the solenoid valve 215. However, if the pick-up head is in its lower position with the piston rods 30 extended and the rod ends depressurized, the switch arm 206 of the pressure switch 205 remains in contact with the "NC" terminal 207 allowing current flow over the lines 210, 212 to light the indicator lamp 211 and energize the solenoid of the valve 215 and over a conductor or line 219 also energizes a solenoid (unnumbered) of an electrical lock valve 220 which shifts the same from the position shown in FIG. 12 to allow hydraulic fluid (oil) to flow from the rod ends of the cylinders 146, 147 over the respective lines 154, 153, another line 221, the valve 220 in the line 221, through the shifted solenoid valve 215 which directs the fluid over a line 222 through a filter 223 into a reservoir 224. The same shifting of the valve 215 allows a pump 225 to deliver oil from the reservoir 224 through a filter 226 and lines 227, 228 and 230 through the solenoid valve 215 and over a flexible conduit or line 231 to the fluid motor M. The motor M rotates the shaft 107 (FIG. 10), the shaft 73 and, of course, the broom 71.
Oil leaves the motor M through a flexible conduit or line 232 which is in turn connected to the lines 151, 152 which direct the pressurized fluid/oil into the respective cylinders 146, 147 causing the extension of the respective rods 148, 149, the pivoting of the arms 84, 85 and, of course, the contact of the broom 71 with the surface S in the manner heretofore described. The line 232 is also connected through a T-fitting to a line 233 which includes therein a relief valve 235 which is set at 160-180 psi. The latter pressure allows the fluid to not only flow into the line 232 but also through the line 233 and the valve 235 and join the fluid exiting the rod ends of the cylinders 146, 147 over the line 221 through the valve 220 returning through the valve 215 over the line 222 and the filter 223 to the reservoir 224.
The pressure builds-up in the cylinders 146, 147 as the broom 71 is progressively forced against the surface S, and the pressure build-up is determined by the setting of the relief valve 235 (160-180 psi). When the head pressure reaches 160-180 psi, the relief valve 235 opens allowing flow through the line 233 while maintaining the set pressure in the line 232 and in the broom cylinders 146, 147 over the lines 151, 152 and exhausting the cylinders 146, 147 over the line 221.
The downward pivoting movement of the broom 71 is, of course, resisted by the tension of the springs 164, 165 and the amount of tension applied to the springs 164,165, as described heretofore by appropriately adjusting the nuts 168, determines the down pressure of the broom 71 against the surface S being swept to establish the desired "burn pattern" heretofore described which essentially is the desired and effective width of broom-to-surface contact. The pressure of the relief valve 235 can be manually set, and the setting of the pressure of the relief valve 235 determines the "rigidity" or "stiffness" of the overall hydraulic system, namely, the fluid resistance offered by the pressure in the cylinders 146, 147 against upward pivotal movement of the broom 71 away from the surface S as a result of debris or objects in the broom path. This same pressure established by the relief valve 235 sets the "digging" ability of the broom 71, namely, the extent to which the bristles 72 thereof will dig into the surface S or deform before the arms 84, 85 will begin to pivot away from the surface S. Thus, increased resistance to this rotation of the broom 71 away from the surface S which increases pressure on the motor M does not increase the down pressure within the cylinders 146, 147 because the cylinders 146, 147 are in the circuit system 150 after or downstream of the motor M and, therefore, do not "see" the increased pressure generated at that point.
In order to turn the system "OFF," the switch 201 is switched from its "ON" position to break the circuit earlier described relative to and beginning with the terminal 202. The system basically stops operating, including the rotation of the broom 71, but the broom 71 is still in contact with the surface S. In order to raise the broom, the switch 201 is switched to its "RAISE" terminal 241 which energizes a solenoid (unnumbered) of the valve 215 over a line 242 and shifts the valve 215 opposite to that heretofore described which allows the pump 225 to pump oil through the line 230, the valve 215, the line 221 and the unshifted valve 220 thereof into the rod end of the cylinders 146, 147 through the lines 153,154 causing retraction and upward pivoting of the broom 71 away from the surface S in the manner heretofore described. Fluid/oil exhausts the cylinders 146, 147 over the lines 151, 152, respectively, the line 232 and through the motor M, the line 231, the solenoid valve 215, the line 222 and the filter 223 back to the reservoir 224. The entire system is now stopped with the broom 71 in its raised position so that the switch 201 can be released and returned to its "OFF" (detented) position.
The pick-up head 10 can also be raised while the broom 71 is rotating in the manner heretofore described. Assuming that the broom 71 is rotating and is in contact with the ground, as earlier described, the pick-up head 10 is raised by pressurizing the line 217 which causes the rods 30 (FIGS. 1 and 2) to retract into the cylinders 26 with the oil being discharged over line 243. The lines 217, 243 are connected through an appropriate solenoid valve (not shown) to a pump 229. This increased pressure is sensed by the pressure sensing valve 205 over the line 216 which switches the contact switch arm 206 from the "NC" terminal 207 to the "NO" terminal 208 which simply opens the circuit over the lines 210, 212. Since there is no current flow in the line 212, the solenoid valve 215 shifts back to its neutral position and the flow of oil returns to the reservoir 224 over the line 222 and filter 223. When the pick-up head 10 is, however, lowered, which relieves the pressure on the rod end of the pick-up head cylinders 26, the switch arm 206 returns from the "NO" terminal 208 position to the "NC" terminal 207 position to resume normal operations.
A pressure relief valve 249, set at 2500 psi, is in a line 250 bridging the lines 222, 230 to by-pass excessively high pressure fluid from the line 230 through the valve 249 and the line 222 directly back to the reservoir 224 through the filter 223 to prevent damaging the pumps 225, 229, the valves and fittings, etc.
Although a preferred embodiment of the invention has been specifically illustrated and described herein, it is to be understood that minor variations may be made in the apparatus without departing from the spirit and scope of the invention, as defined the appended claims. For example, the separately formed bearings 102, 103 can be formed as a single bearing. Moreover, instead of the bearings 102, 103 being manufactured separately from the hub 104, these can be made as a single integral structure. In other words, the hub 104 can have an internal machined cylindrical bearing surface (need not be Teflon-coated).
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A pick-up head is formed by a housing which defines a broom chamber rearward of an associated air pressure chamber and its associated blast orifice. The broom is rotated in a direction to impel debris from a surface in the same direction as air emitted from the blast orifice toward an associated air suction chamber. Due to the latter arrangement, debris which is "tacky" which is "stuck" onto the surface, or which is too heavy to be moved into the suction air stream by the blast air alone is impelled at a relatively high entrainment velocity toward and into the air suction stream which continues the movement of this debris for eventual discharge into an associated hopper.
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This application claims the benefit of U.S. Provisional Application No. 60/287,649 filed on Apr. 30, 2001.
BACKGROUND OF THE INVENTION
1. Field of the Invention
This invention relates generally to a method for the control of oil and gas production wells. More particularly, it relates to a communication protocol for a multi-well, multi-zone control system for providing communications signals between components of the system to ensure that each component reliably receives communications intended for it.
2. Description of the Related Art
The control of oil and gas production wells constitutes an on-going concern of the petroleum industry due, in part, to the enormous monetary expense involved as well as the risks associated with environmental and safety issues.
Production well control has become particularly important and more complex in view of the industry wide recognition that wells having multiple branches (i.e., multilateral wells) will be increasingly important and commonplace. Such multilateral wells include discrete production zones which produce fluid in either common or discrete production tubing. In either case, there is a need for controlling zone production, isolating specific zones and otherwise monitoring each zone in a particular well. Before describing the current state-of-the-art relative to such production well control systems and methods, a brief description will be made of the production systems, per se, in need of control. One type of production system utilizes electrical submersible pumps (ESP) for pumping fluids from downhole. In addition, there are two other general types of productions systems for oil and gas wells, namely plunger lift and gas lift. Plunger lift production systems include the use of a small cylindrical plunger which travels through tubing extending from a location adjacent the producing formation down in the borehole to surface equipment located at the open end of the borehole. In general, fluids which collect in the borehole and inhibit the flow of fluids out of the formation and into the wellbore, are collected in the tubing. Periodically, the end of the tubing is opened at the surface and the accumulated reservoir pressure is sufficient to force the plunger up the tubing. The plunger carries with it to the surface a load of accumulated fluids which are ejected out the top of the well thereby allowing gas to flow more freely from the formation into the wellbore and be delivered to a distribution system at the surface. After the flow of gas has again become restricted due to the further accumulation of fluids downhole, a valve in the tubing at the surface of the well is closed so that the plunger then falls back down the tubing and is ready to lift another load of fluids to the surface upon the reopening of the valve.
A gas lift production system includes a valve system for controlling the injection of pressurized gas from a source external to the well, such as another gas well or a compressor, into the borehole. The increased pressure from the injected gas forces accumulated formation fluids up a central tubing extending along the borehole to remove the fluids and restore the free flow of gas and/or oil from the formation into the well. In wells where liquid fall back is a problem during gas lift, plunger lift may be combined with gas lift to improve efficiency.
In both plunger lift and gas lift production systems, there is a requirement for the periodic operation of a motor valve at the surface of the wellhead to control either the flow of fluids from the well or the flow of injection gas into the well to assist in the production of gas and liquids from the well. These motor valves are conventionally controlled by timing mechanisms and are programmed in accordance with principles of reservoir engineering which determine the length of time that a well should be either “shut in” and restricted from the flowing of gas or liquids to the surface and the time the well should be “opened” to freely produce. Generally, the criteria used for operation of the motor valve is strictly one of the elapse of a preselected time period. In most cases, measured well parameters, such as pressure, temperature, etc. are used only to override the timing cycle in special conditions.
It will be appreciated that relatively simple, timed intermittent operation of motor valves and the like is often not adequate to control either outflow from the well or gas injection to the well so as to optimize well production. As a consequence, sophisticated computerized controllers have been positioned at the surface of production wells for control of downhole devices such as the motor valves.
In addition, such computerized controllers have been used to control other downhole devices such as hydro-mechanical safety valves. These typically microprocessor based controllers are also used for zone control within a well and, for example, can be used to actuate sliding sleeves or packers by the transmission of a surface command to downhole microprocessor controllers and/or electromechanical control devices.
The surface controllers are often hardwired to downhole sensors which transmit information to the surface such as pressure, temperature and flow. This data is then processed at the surface by the computerized control system. Electrically submersible pumps use pressure and temperature readings received at the surface from downhole sensors to change the speed of the pump in the borehole. As an alternative to downhole sensors, wire line production logging tools are also used to provide downhole data on pressure, temperature, flow, gamma ray and pulse neutron using a wire line surface unit. This data is then used for control of the production well.
A problem associated with known control systems is the reliability of surface to downhole signal integrity. It will be appreciated that should the surface control signal be in any way compromised on its way downhole, then important control operations will not take place as needed. As distances between the surface system and downhole controllers increases, the signal is attenuated and may fall below a level required for reliable communication.
SUMMARY OF THE INVENTION
The methods and apparatus of the present invention overcome the foregoing disadvantages of the prior art by providing a reliable method of communication for a multi-well, multizone completion system.
In one aspect, a method for controlling production from a formation having at least one producing well disposed therein, the at least one producing well having a plurality of producing zones, comprises; installing a flow control device with a controller proximate each of the producing zones where each controller has a predetermined communication address, and each controller is adapted to act as a repeater on command from a surface controller; connecting each controller to a transmission bus, where the transmission bus is connected to the surface controller; transmitting a command message from the surface controller to a predetermined controller, where the command message determines a predetermined path along the transmission bus according to a predetermined protocol; receiving the command message by the predetermined controller; and executing the command message to control the flow control device.
In another aspect of the present invention, a method involves transmission of a command message from a master node, through at least one repeater node, to a destination node, each node having a separate unique address to ensure that the message is repeated, received, and executed only by the intended nodes. The method comprises transmitting a command message on a communication bus from a master node, having the message relayed by at least one repeater node to a destination node. The command message comprises a command synchronization string, a command origin address, at least one repeater address, and a destination address. The path of the message is determined by routing information in the address of each node in the header. The destination node interprets and executes the message and sends a response message by modifying the routing bits to retrace the path of the command message. The response message is received and interpreted by the master node and used by the surface system to control the well production.
In another preferred embodiment, the method involves transmission of a command message from a master node to a destination node, each node having a separate unique address to ensure that the message is received, and executed only by the intended node. The method comprises transmitting a command message on a communication bus from a master node to a destination node. The command message comprises a command synchronization string, a command origin address and a destination address. The path of the message is determined by routing information in the address of each node in the header. The destination node interprets and executes the message and sends a response message by modifying the routing bits to retrace the path of the command message. The response message is received and interpreted by the master node and used by the surface system to control the well production.
Examples of the more important features of the invention thus have been summarized rather broadly in order that the detailed description thereof that follows may be better understood, and in order that the contributions to the art may be appreciated. There are, of course, additional features of the invention that will be described hereinafter and which will form the subject of the claims appended hereto.
BRIEF DESCRIPTION OF THE DRAWINGS
For detailed understanding of the present invention, references should be made to the following detailed description of the preferred embodiment, taken in conjunction with the accompanying drawings, in which like elements have been given like numerals, wherein:
FIG. 1 is a diagrammatic view depicting a multiwell/multizone control system for controlling a plurality of offshore wells according to one embodiment of the present invention.
FIG. 2 is a diagrammatic view of a portion of FIG. 1 depicting a selected well and selected zones in the selected well and a downhole control system according to one embodiment of the present invention.
FIG. 3 is a schematic flow diagram of a command message transmitted from a master node to a slave node according to one embodiment of the present invention.
FIG. 4 is a schematic flow diagram of a command message transmitted from a slave/repeater node to a destination node according to one embodiment of the present invention.
FIG. 5 is a schematic flow diagram of a response message from a destination node to a slave/repeater node according to one embodiment of the present invention.
FIG. 6 is a schematic flow diagram of a response message from a slave/repeater node to a master node according to one embodiment of the present invention.
FIG. 7 is a schematic flow diagram of a command message from a master node to a destination node according to one embodiment of the present invention.
FIG. 8 is a schematic flow diagram of a response message from a destination node to a master node according to one embodiment of the present invention.
DESCRIPTION OF PREFERRED EMBODIMENTS
The downhole Intelligent Completion System(ICS) is composed of downhole sensors, downhole control electronics and downhole electromechanical modules that can be placed in different locations (e.g., zones) in a well, with each downhole control system having a unique electronic address. A number of wells can be outfitted with these downhole control devices. The surface control and monitoring system interfaces with all of the wells where the downhole control devices are located to poll each device for data related to the status of the downhole sensors attached to the module being polled. In general, the surface system allows the operator to control the position, status, and/or fluid flow in each zone of the well by sending a command to the device being controlled in the wellbore.
Referring to FIG. 1, the multiwell/multizone monitoring and control system of the ICS may include a remote central control center 10 which communicates either wirelessly or via telephone wires to a plurality of well platforms 12 . Any number of well platforms may be encompassed by the control system with three platforms namely, platform 1 A, platform 1 B, and platform 1 N being shown in FIG. 1 . Each well platform has associated therewith a plurality of wells 14 which extend from each platform 12 through water 16 to the surface of the ocean floor 18 and then downwardly into formations under the ocean floor. It will be appreciated that while offshore platforms 12 have been shown in FIG. 1, the group of wells 14 associated with each platform are analogous to groups of wells positioned together in an area of land; and the present invention therefore is also well suited for use with land based wells.
As mentioned, each platform 12 is associated with a plurality of wells 14 . For purposes of illustration, three wells are depicted as being associated with platform number 1 A with each well being identified as well number 2 A, well number 2 B and well number 2 N. As is known, a given well may be divided into a plurality of separate zones which are required to isolate specific areas of a well for purposes of producing selected fluids, preventing blowouts and preventing water intake. Such zones may be positioned in a single vertical well such as well 19 associated with platform 1 B shown in FIG. 1 or such zones can result when multiple wells are linked or otherwise joined together. A particularly significant contemporary feature of well production is the drilling and completion of lateral or branch wells which extend from a particular primary wellbore. These lateral or branch wells can be completed such that each lateral well constitutes a separable zone and can be isolated for selected production.
With reference to FIGS. 1 and 2, each of the wells 2 A, 2 B and 2 N associated with platform 1 A include a plurality of zones which need to be monitored and/or controlled for efficient production and management of the well fluids. For example, with reference to FIG. 2, well number 2 B includes three zones, namely zone number 3 A, zone number 3 B and zone number 3 N. Each of zones 3 A, 3 B and 3 N have been completed in a known manner. Zone number 3 A has been completed using a known slotted liner completion, zone number 3 B has been completed using an open hole selective completion and zone number 3 N has been completed using a cased hole selective completion with sliding sleeves. Associated with each of zones 3 A, 3 B and 3 N is a downhole control system 22 . Similarly, associated with each well platform 1 A, 1 B and 1 N is a surface control system 24 .
As discussed, the multiwell/multizone control system of the present invention is comprised of multiple downhole electronically controlled electromechanical devices and multiple computer based surface systems operated from multiple locations. An important function of these systems is to predict the future flow profile of multiple wells and monitor and control the fluid or gas flow from the formation into the wellbore and from the wellbore to the surface. The system is also capable of receiving and transmitting data from multiple locations such as inside the borehole, and to or from other platforms 1 A, 1 B or 1 N or from a location away from any well site such as central control center 10 .
The downhole control modules 22 interface to the surface controller 24 using an electrical wire (i.e., hardwired) connection. Alternatively, data and command signals may be transmitted over optical fibers (not shown) using techniques known in the art. The modules 22 contain circuitry and processors which act according to programmed instructions to control the actuation of the downhole devices and sensors used in production wells. The downhole modules 22 in the wellbore can transmit and receive data and/or commands to or from the surface and/or to or from other devices in the borehole.
Surface controller 24 can control the activities of the downhole control modules 22 by requesting data on a periodic basis and commanding the downhole modules to open, or close electromechanical devices and to change monitoring parameters due to changes in long term borehole conditions.
Turning again to FIG. 2, an example of the downhole system is shown in an enlarged view of well number 2 B from platform 1 A depicting zones 3 A, 3 B and 3 N. In zone 3 A, a slotted liner completion is shown at 69 associated with a packer 71 . In zone 3 B, an open hole completion is shown with a series of packers 71 and intermittent sliding sleeves 75 . In zone 3 N, a cased hole completion is shown again with the series of packers 77 , sliding sleeve 79 and perforating tools 81 . The control system 22 in zone 3 A includes electromechanical drivers and electromechanical devices which control the packers 69 and valving associated with the slotted liner so as to control fluid flow. Similarly, control system 22 in zone 3 B include electromechanical drivers and electromechanical devices which control the packers, sliding sleeves and valves associated with that open hole completion system. The controller 22 in zone 3 N also includes electromechanical drivers and electromechanical control devices for controlling the packers, sliding sleeves and perforating equipment depicted therein. Any suitable electromechanical driver or electromechanical control device may be used in connection with this invention to control a downhole tool or valve.
Information sent from the surface to a controller 22 may consist of actual control information, or may consist of data which is used to reprogram the memory in a downhole processor 50 (not shown) for initiating a control action based on sensor information. In addition to reprogramming information, the information sent from the surface may also be used to recalibrate a particular downhole sensor (not shown). Processor 50 may not only send raw data and status information to the surface, but may also process data downhole using appropriate algorithms and other methods so that the information sent to the surface constitutes derived data in a form well suited for analysis.
As is known in the communication art, long communication channels may suffer signal to noise degradation as the communication channel length becomes relatively long. This signal to noise degradation may result in reduced data rate. There is, therefore, a maximum transmission distance (MTD) for a desired data rate. When the distance from the surface controller to the intended destination controller exceeds the MTD, the present invention utilizes repeaters in the communication line to receive and retransmit the control message to the intended destination controller. The downhole controllers 22 in each production zone can act as repeaters for receiving and re-transmitting control signals. In the case where the distance from the surface controller to the uppermost production zone exceeds the MTD, repeaters 55 may be inserted in the production tubing string to receive and retransmit the signal.
It is of the utmost importance from both a production and a safety standpoint that the control message is acted on only by the intended destination controller. The present invention uses a transmission bus with a novel transmission protocol to ensure that the message is received and acted on only by the intended destination controller. The bus comprises a master node and multiple slave nodes communicating over one or more electrical and/or optical conductors. Such electrical and electro-optical cables are known in the art and are not described further. Each of the repeaters 55 and the controllers 22 are slave nodes on the bus. Each node has a unique identifying electronic address.
Referring to FIGS. 1 and 2, in a preferred embodiment, the surface controller 24 is designated as a master node and the repeaters 55 and controllers 22 are designated as slave nodes. The master sends command messages to a controller 22 to obtain data or to perform a particular function. When the distance between the master and the destination controller exceeds the MTD, the message is routed through another node physically located between the master and the destination node/controller 22 . Note that controllers 22 can act as repeater nodes or they may be the destination node for the message. Repeater 55 can only act to repeat the message. The decision to use a particular slave node as a repeater can be made in the field. More than one repeater may be included in the transmission path. The routing information is contained in the header of the message. If a particular node is to repeat the message, then the header of the message will contain the address of that particular node, with the instruction to repeat the message to another node. Other nodes, whose addresses are not included in the header, ignore the message. As the message travels through each addressed repeater the routing information is changed, according to the predetermined protocol, but the destination address and the command message are not changed. The destination node receives, recognizes, and acts on the command message. The destination node then sends a response message to the master controller, using the same nodes as the command message, in reverse order.
FIGS. 3-7 show examples of the transmission protocol with the header 100 having a three address capacity, for use with a single repeater. In another preferred embodiment, the header 100 can accommodate more than three addresses and use more than one repeater. FIGS. 3-7 show an example of a three node system, where the master, node A 101 sends a command to node C 103 , via a repeating node B 102 . The command message header 100 contains a command synchronization string 105 , an origin address 110 , a repeater node address 115 , and a destination address 120 . The command synchronization string 105 is a unique string of bits which is prohibited from occurring as a command word or data word, and which is an exclusive bit string used to identify the following bits as a command message. Note that the order of the addresses in the header follows the order in which the message travels, in a from-to manner.
A routing string is present at the beginning of each address. The routing string contains at least one primary routing bit for designating the associated address as a destination node, and at least one secondary routing bit for designating the next node to receive and repeat/execute the command. In this preferred embodiment, the routing string comprises the first two bits of each address field. Here the primary bit is the first bit, and is used to indicate whether or not the associated address is a destination node. Here the term destination node means the node which will execute the command signal. If the primary bit is a one, the associated address is a destination node. Here the secondary bit is the second bit and designates the next node to receive and repeat/execute the command. The actual routing bit order may be reversed as long as the designation of the primary and secondary bits remains consistent. In other preferred embodiments, the routing information may be contained in any other predetermined length routing string with at least one primary bit and at least one secondary bit. Such strings may include, but are not limited to a nibble (4 bits) or a byte (8 bits).
In operation, a command message, with header, is transmitted on the communication bus and is recognized by the nodes with the appropriate addresses. Node B 102 receives the message and interprets the routing string to determine that it is to retransmit the command message to node C 103 . Node B 102 reconfigures the routing string according to the protocol (see FIG. 4 ), and transmits the signal to node C 103 which executes the command as directed. Node C 103 responds with a confirmation that the command has been executed.
This response message could be a status flag, a sensor reading, downhole processed data, or any other suitable evidence of command execution. Node C reconfigures the header by retracing the node order of the command message 100 , changes the routing string, and replaces the command synchronization string 105 with a unique data synchronization string 155 , as shown in FIG. 5 . The data synchronization string 155 , like the command synchronization string 105 , is also prohibited from occurring as a command or data word. The response message is sent from node C 103 to node B 102 . Node B 102 interprets the routing string to determine that the message is to be retransmitted. Node B 102 changes the routing string, according to the routing protocol, see FIG. 6, and retransmits the message to node A 101 , thereby completing the transmission sequence.
FIGS. 7 and 8 illustrate the case where no repeater is required to transmit the signal from the surface controller 24 to a particular downhole controller 22 . The command message header 100 contains a command synchronization string 105 , an origin address 105 , a destination address 120 , and a null address 130 . As discussed before, the routing string in this embodiment is contained in the first two bits of each address. The response message header 150 contains a data synchronization string 155 , an origin address 160 , a destination address 170 , and a null string 130 . Here the null string is used to maintain the header length for a single repeater header format and can be the same string for both the command and the response messages. In another preferred embodiment, n repeaters may be incorporated in the header format. In that case, for a direct communication as illustrated in FIGS. 7 and 8, n null strings 130 would be attached to the header after the destination address 120 .
The foregoing description is directed to particular embodiments of the present invention for the purpose of illustration and explanation. It will be apparent, however, to one skilled in the art that many modifications and changes to the embodiment set forth above are possible without departing from the scope and the spirit of the invention. It is intended that the following claims be interpreted to embrace all such modifications and changes.
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A method for two-way communication for controlling production from a formation having at least one producing well and a plurality of producing zones. In one embodiment, the method comprises installing a flow control device with a controller proximate each of the producing zones, where each controller has a predetermined communication address, and each controller is adapted to act as a repeater on command from a surface controller; connecting each controller to a transmission bus where the transmission bus is connected to the surface controller; transmitting a command message from the surface controller to a predetermined downhole controller, where the command message determines a predetermined path along the transmission bus according to a predetermined protocol; receiving the command message by the predetermined controller; and executing the command message to control the flow control device. Transmitting a response message back along the predetermined path.
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CROSS-REFERENCE TO RELATED APPLICATION
[0001] This application claims the benefit of U.S. Provisional Patent Application No. 60/670,989 filed Apr. 14, 2005.
BACKGROUND OF THE INVENTION
[0002] 1. Field of the Invention
[0003] The present invention relates to the field of support stands, and more particularly to novel stands for supporting a motorcycle in a static or leaning position and which may be stored in the open-ended bore of the rear axle when not in use.
[0004] 2. Prior Art
[0005] In the past, it has been the conventional practice to provide a stand for a two-wheeled vehicle, such as a motorcycle, bike or the like, by employing a deployable stand having one end pivotally mounted to the vehicle frame and the other end extendable for ground engagement. The pivot end is a fixed structure that usually represents a substantial mass, and attachment of the pivot end of the stand generally requires a weldment for permanent securement. Such an installation is permanent and is not intended to be detachably connected to the frame. Generally, the stand is located at a midpoint on the frame between the front and rear wheels of the motorcycle.
[0006] Problems and difficulties have been encountered with using conventional motorcycle stands which stem largely from the fact that a permanent attachment to the frame is necessary, and the location of the stand, being midway between the wheels, often times becomes an obstacle for mounting and dismounting the motorcycle by the rider.
[0007] Therefore, a long-standing need has existed to provide support stands for two-wheeled vehicles, such as a motorcycle, which will not interfere with the rider's use of the vehicle and which is not permanently attached to the frame of the motorcycle. The stand should be detachably connected to a portion of the motorcycle which will support the weight of the motorcycle in a leaning orientation and which employs articulated support members so that the stand may be deployed from a stored position on the motorcycle to an operative support position holding the bike in the leaning orientation.
BRIEF DESCRIPTION OF THE DRAWINGS
[0008] FIG. 1 is a perspective view of the back end of a conventional motorcycle incorporating an embodiment of the inventive motorcycle stand in its stored position on the rear axle of the vehicle.
[0009] FIG. 2 is a perspective view, similar to the view of FIG. 1 , illustrating the stand deployed into its operative position for supporting the motorcycle.
[0010] FIG. 3 is a perspective view of the motorcycle stand illustrating adjustability for length.
[0011] FIG. 4 is a reduced front elevational view of a conventional motorcycle illustrated in a leaning position supported by the inventive motorcycle stand in its operative position.
[0012] FIG. 5 is a longitudinal sectional view of the motorcycle stand in its operative position.
[0013] FIG. 6 is a sectional view of the motorcycle stand preparatory for deployment into its storage position.
[0014] FIG. 7 is a sectional view, similar to the view of FIG. 6 , illustrating a further step in preparing the motorcycle stand for storage within the open bore of a wheel axle.
[0015] FIG. 8 is a sectional view illustrating positioning of the motorcycle stand into the bore of an axle to complete storage thereof.
[0016] FIG. 9 is a perspective view of the back end of a conventional motorcycle illustrating, in a partially exploded view, another embodiment of the inventive motorcycle stand and it's mounting within the rear axle of the vehicle.
[0017] FIG. 10 is an exploded perspective view of the stand of FIG. 9
[0018] FIG. 11 is a perspective view of the stand of FIG. 9 illustrating the stand about to be deployed into its operative state.
[0019] FIG. 12 is a cross section taken through a motorcycle axle and the stand of FIG. 9 as stored therein between uses.
DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS
[0020] Accordingly, the above problems and difficulties are avoided by the present invention that provides an adjustable length support member having a foot attached at its distal end for engaging the ground in order to support the motorcycle in a leaning position. In one embodiment, the opposite end of the support member includes a joint member which is pivotally attached to the end of the support member. The joint member is insertably received into the open-ended bore of the rear axle conventionally carried on the motorcycle and includes a biasing means for engaging and disengaging the support member to and from the joint member so as to permit pivoting of the support member to an angular disposition with respect to the joint member. A locking shoulder means via the biasing means releasably secures the end of the support member to the end of the joint member when the angle of the support member has been achieved. For extending the length of the support member, an extension rod or tube is slidably mounted within the support member and latch means are cooperatively provided between the rod or tube and the support member so that a pre-arranged adjustment can be made for length of the overall support member. A spring detent is provided on the joint member for releasably retaining the joint member in the bore of the axle.
[0021] In another embodiment, the end of the support member opposite the foot includes a member that is attachable to the end of the support member in either of two orientations, a first being concentric with the support member for storage in the rear axle of a motorcycle and the second being at angle with respect to the support member for functioning as a stand. Other aspects of this embodiment are similar to the first embodiment.
[0022] Therefore, it is among the objects of the present invention to provide novel support stands for motorcycles which are adjustable in length and which are detachably mounted to the rear axle of the motorcycle and wherein the stands may be deployable between a stored position on the axle and an operative position to support a motorcycle in a leaning position.
[0023] Another object of the present invention is to provide novel stands for motorcycles which are not permanently attached to the frame or any other portion of the motorcycle and which may be conveniently and manually deployed from a stored position on the axle of a motorcycle to an operative position supporting the motorcycle.
[0024] Yet another object resides in providing a support for a two wheeled vehicle which includes a member releasably retained on the rear axle of the vehicle and which further includes a support member having a stored position on the axle and an operative position outwardly extendable for supporting the vehicle in a leaning position.
[0025] Referring to FIG. 1 , one embodiment of the novel motorcycle stand incorporating the present invention is illustrated in the general direction of arrow 10 by numeral 11 and is illustrated as being in a storage position so that the motorcycle can be ridden in a normal fashion without interference from the stand 10 . It is to be noted that the stand 10 is detachably carried on an axle 19 as part of a rear wheel 12 including tire 13 . The stand 10 includes a foot 14 that is the only component of the stand that is exposed when the stand is in the storage position. The foot 14 bears against or is adjacent a housing cover 15 . Therefore, it can be seen that the motorcycle stand 10 is mounted on the rear axle 11 and is deployable between a storage position, as shown in FIG. 1 , and an extended or operational position, as shown in FIGS. 2 and 4 , respectively.
[0026] Referring now in detail to FIG. 2 , it can be seen that the motorcycle stand 10 includes a tubular support member 16 having one end pivotally joined to an anchor or a joint member 17 . If it is desired to lengthen the support member 16 , a rod or tubular extension 18 may be extended from the member 16 and held in position by a latch 22 . In FIGS. 2 and 4 , the support stand is deployed into its operative position to support the motorcycle in a leaning orientation. The rod 18 has been extended from the end of support member 16 so that the foot 14 rests on ground level. The joint member 17 resides within the axle of the rear wheel as an anchor or mounting member.
[0027] Referring now to FIG. 3 , it can be seen that the joint member 17 is pivotally carried on the upper end of support member 16 by means of a pivot 20 . The joint member 17 further includes a retaining detent 21 which is spring biased to bear against the inner surface of the open-ended bore within the axle 19 in order to releasably retain the support stand in either its storage or operative position. As illustrated in broken lines, the joint member 17 has been pivoted for either insertion into the bore of the axle or to illustrate deployment of the support member 16 . The manual latch 22 comprises a spring biased button which protrudes through an opening 24 in the support member 16 in order to hold the rod 18 therein. When it is desired to extend the length of the support member 16 , the latch 22 is depressed permitting the rod 18 to be withdrawn from the support member to the position shown in broken lines and the rod is held in this position by the push-button latch 22 engaging with a hole 23 at the lower end of the support member 16 .
[0028] Referring now in detail to FIG. 5 , it can be seen that the support member or arm 16 has been outwardly deployed to its operative position by withdrawing the support member out of the axle 19 and pivoting about pivot 20 to the latched position shown. The longitudinal axis of the support member is angular with respect to a vertical axis. It can be seen that foot 14 rests on the ground and that rod 18 has been extended from its position inside the bore of support member 16 .
[0029] The rod 18 is retained in the extended position by means of latch 22 engaging with hole 23 . Upon retraction of the extension rod 18 into support member 16 , latch 22 will be retained in opening 24 . It is to be noted that the latch 22 is spring biased outwardly so that the normal bias of the latch is to occupy either opening 24 or opening 23 . The joint member 16 includes the detent 21 that is outwardly urged by an expansion spring to bear against the bore of axle 19 to releasably retain the entire support assembly in place. Once the support member is in place as shown in FIG. 5 , note that the member 16 is locked to the joint member by means of engaging shoulders 26 on the end of joint member 17 and shoulder 27 near the end of support member 16 . The pair of shoulders are pulled together by means of an expansion spring 28 which bears against one end of the joint member within chamber 30 and bears against an element 31 at its opposite end. The element 31 is carried at the end of a slide mount 32 that has the pivot 20 at its end opposite to element 31 . Therefore, as the mount 32 slidably moves in and out of the end of joint member 17 in response to compression or expansion of spring 28 , the shoulders 26 and 27 are engaged or disengaged.
[0030] Referring now to FIG. 6 , it can be seen that the shoulders 26 and 27 are disengaged as the joint member 17 is moved in the direction of the arrow. The solid line showing of support member 16 is representative of a disengagement of the shoulders while in broken lines, engagement is illustrated as in FIG. 5 . The compression of spring 28 is manual by pulling the end of support 16 outwardly in the direction of the arrow.
[0031] To store the support member within the bore of axle 19 from the position shown in FIG. 5 , the support member is pulled in the direction of the arrow shown in FIG. 6 , followed by pivoting of the support member in the direction, as shown in FIG. 7 . The shoulders are disengaged and the support member is free to rotate about pivot 20 . As shown in FIG. 7 , the longitudinal axis of the support member 16 and the joint member 11 are coaxially disposed with respect to one another and the members 16 and 17 can then be pushed in the direction of the arrow shown in FIG. 8 for storage within the bore of the axle 19 . Abutment of the foot 14 with the end of the axle serves as a stop and the showing in FIG. 8 is also the showing in FIG. 1 of the support member in its storage position.
[0032] To deploy the support member into its operative position, the reverse of the procedures described and shown in FIGS. 5-8 are followed. From the storage position shown in FIG. 8 , the support member 16 and joint member 17 are slid through the bore of axle 19 while still being retained therein by the retaining detent 21 . When the end of joint member 17 is beyond the terminating end of the axle, as shown in FIG. 7 , the support member 16 can be pulled in the direction of the arrow shown in FIG. 6 to compress the spring 28 and the member can be pivoted into the operative position, as shown in FIG. 5 , wherein the engagement of shoulders 26 and 27 can be permitted due to the expansion of spring 28 so that a releasable locking means is provided. To extend the length of the support member, the tube or rod 18 may be deployed, as previously described by releasing the latch 22 and engaging the latch into the lower opening 23 .
[0033] Now referring to FIGS. 9 through 12 , an alternate embodiment of the present invention may be seen. This embodiment is functionally equivalent to the first embodiment, though differs in certain structural aspects. In particular, as may be best seen in the exploded view of FIG. 10 , a telescoping assembly comprising a tubular support member 33 , similar to the tubular support member 16 of the prior embodiment, is used together with a tubular extension 34 , similar to tubular extension 18 in the prior embodiment. The tubular extension 34 has a foot 35 , also similar to the foot 14 of the prior embodiment. A push button spring detent 36 , similar to push button detent 22 of the prior embodiment, is provided to lock the telescoping assembly comprising tubular support member 33 and tubular extension 34 in an unextended position by engagement of the push button with hole 37 in tubular support member 33 , or in one of two extended positions by engagement with hole 38 or 39 in the tubular support member 33 .
[0034] FIG. 12 presents a cross-section of the embodiment illustrated in FIGS. 9 through 11 . The tubular support member 33 , the tubular extension 34 and the foot 35 , as well as the spring loaded push button 36 , may be seen therein. Also shown therein is a member 40 having a pin 41 which may extend longitudinally into a hole in the end of tubular support member 33 , as shown in FIG. 12 . The pin 41 also has a square end 42 thereon with a spring loaded ball 43 for providing a detent type engagement with retaining member 44 , held and angularly oriented within hollow axle 45 by a screw 46 fastening the retaining member 44 to the internal end of the hollow axle. A spring member 47 in a slot in member 40 retains pin 41 with respect to member 40 , as well as provides a spring detent to releasably retain member 40 with respect to tubular support member 33 when in the orientation illustrated in FIGS. 9, 10 and 12 .
[0035] Also visible, particularly in FIGS. 10 and 12 , is a hole 48 passing through the end of tubular support member 33 at an angle with respect to the axis thereof. With the assembly in the angular orientation illustrated in FIGS. 9, 10 and 12 , the end of hole 48 cooperates with the end of spring 47 to provide a detent to retain member 40 in the position shown with respect to the tubular support member 33 . However, member 40 , with pin 41 thereon, may be withdrawn from the coaxial engagement with the end of tubular support member 33 as illustrated in FIGS. 9, 10 and 12 , and instead, coupled to the tubular support member 33 by passing pin 41 through hole 48 to be retained in that position by spring 47 lying within slot 49 and passing into hole 50 in the end of tubular support member 33 . When so positioned, the stand of this embodiment may function as previously illustrated with respect to FIGS. 2 and 4 . Thus in the embodiment of FIGS. 1 through 8 , one end of the overall assembly may be rotated through an angle between a first angular orientation with respect to the telescoping assembly wherein the end configured to extend into the hollow axle is co-linear with the telescoping assembly, and a second angular position facilitating use of the assembly as a motorcycle stand, whereas in the embodiment of FIGS. 9 through 12 , the end of the assembly is similarly capable of being oriented at either of these two angular positions, though by removing the end of the assembly and repositioning the same with respect to the telescoping assembly. Obviously also, there are other differences in design detail, though the function and use of these, as well as other embodiments, is the same.
[0036] Thus while particular embodiments of the present invention have been shown and described, it will be obvious to those skilled in the art that changes and modifications may be made without departing from this invention in its broader aspects and, therefore, the aim in the appended claims is to cover all such changes and modifications as fall within the true spirit and scope of this invention.
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A stand for a two wheeled vehicle having a hollow axle comprising, the stand having a telescoping support assembly having a foot at a first end thereof, the telescoping support assembly being extendable between an unextended position and an extended position and being releasably lockable in the extended position, a latch for releasably maintaining the telescoping support assembly in the extended position, a first member being disposable at first and second angular positions relative to a second end of the telescoping support assembly, the first angular position being coaxial with the telescoping support assembly and the second angular position being a predetermined angle with respect to the telescoping support assembly, the first member being releasably lockable in the second angular position. The stand is configured to fit and be retained within a hollow axle for storage, and to be deployed to provide a side stand using the hollow axle for reference to the two wheeled vehicle. Various embodiments are disclosed.
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CROSS REFERENCE TO RELATED APPLICATIONS
This application is a continuation of U.S. application Ser. No. 12/563,204 filed on Sep. 21, 2009, which is a division of U.S. application Ser. No. 11/782,295 filed on Jul. 24, 2007, which is a division of U.S. application Ser. No. 11/213,833 filed on Aug. 30, 2005, which issued as U.S. Pat. No. 7,348,615, on Mar. 25, 2008. The entire disclosures of these prior applications are incorporated herein by reference.
BACKGROUND OF THE INVENTION
1. Field of the Invention
The present invention relates to an image pickup device and a camera, and more particularly to an image pickup device and a camera in which charges are converted into a voltage in a pixel region to be read as a voltage signal like an active pixel sensor (APS).
2. Description of Related Art
In recent years, a demand for a digital single lens reflex camera has been developing, and a sensor used in the digital single lens reflex camera is sized to be large one from APS-C size to a 35 mm film size.
Moreover, the used sensor itself widely varies from a CCD to an APS and the like.
Japanese Patent Application Laid-Open No. 2001-230400 (corresponding U.S. application was published as U.S. Publication 2001012133A) discloses an amplifying type image pickup device having a plurality of two-dimensionally arranged pixels, each including a photoelectric conversion element and an amplifying transistor, wherein: a first conductivity type semiconductor region constituting each photoelectric conversion element is formed in a common well composed of a second conductivity type semiconductor formed in a first conductivity type semiconductor substrate; a first conductivity type semiconductor region constituting a source and a drain of each of the amplifying transistors is formed in the common well; and a plurality of electric contacts for supplying a reference voltage to the common well is provided in the inside of the pixel array area in the common well.
In the APS sensor which has the large image pickup surface mentioned above, it is necessary to perform a voltage conversion of charges based on certain reference potential. When the reference potential is distributed on the image pickup surface, also the optical signal having received the voltage conversion has shading according to the distribution. Thus, there is a problem in which image performance is seriously damaged.
For coping with the problem, the prior art disclosed in the publication mentioned above provides an electrode for fixing the potential of the well in which a source follower is arranged to the reference potential when the source is used as an amplifying portion in a pixel, for example.
FIG. 10 is a sectional view showing the cross-sectional structure of prior art. In FIG. 10 , an electrode region for taking well potential is denoted by a reference numeral 2 .
A reference numeral 1 denotes n-type semiconductor region forming a photoelectric conversion region. A reference numeral 2 denotes p-type semiconductor region. A reference numeral 3 denotes a well contact wiring. A reference numeral 4 denotes P-well. A reference numeral 12 denotes an element isolation region. Reference numerals 13 - 17 denote source and drain regions of MOS transistor. A reference numeral 101 denotes a photoelectric conversion unit. A reference numeral 102 denotes a transfer MOS transistor. A reference numeral 103 denotes a reset MOS transistor. A reference numeral 104 denotes a selection MOS transistor. And, a reference numeral 105 denotes an amplifying MOS transistor.
FIG. 11 is a plan view showing the planar structure of the prior art. The well region 2 of FIG. 10 corresponds to a well electrode 1101 in FIG. 11 .
A reference numeral 1104 denotes a photodiode. A reference numeral 1102 denotes a poly wiring (poly gate). A reference numeral 1103 denotes a MOS transistor unit (N + ). L min denotes element isolation width. And, S min denotes an area of the well electrode 1101 .
Generally, between a well region and a light receiving unit, an insulating isolation region represented by the localized oxidation of silicon (LOCOS), the shallow trench isolation (STI) and the like is arranged. In FIG. 10 , LOCOS 12 is arranged as such an element isolation region.
In arranging the element isolation region, the following restrictions are especially given from a viewpoint of an exposure process on production. Those are (1) the securement of the minimum separation width Lmin and (2) the securement of the minimum electrode area Smin.
In performing the miniaturization of a pixel, by the restrictions mentioned above, the light receiving area of a photodiode used as the light receiving unit becomes small, and the sensor performance has been worsened in terms of the optical property thereof, the saturated charge amount thereof, and the like.
Accordingly, it is an object of the present invention to provide a solid state image pickup device and a camera which do not worsen the sensor performance in terms of the optical property thereof, the saturated charge amount thereof, and the like.
SUMMARY OF THE INVENTION
As means for solving the problem mentioned above, the present invention is a solid state image pickup device including a pixel region having a plurality of pixels, the solid state image pickup device provided with at least a light receiving unit and an amplifying portion amplifying photocharges outputted from the light receiving unit in the pixel region, and further provided with a first semiconductor region for regulating potential of a well region, in which the amplifying portion is arranged, wherein no element isolation regions made of insulators are arranged between a first impurity region and the light receiving unit.
Moreover, the present invention is a solid state image pickup device including a pixel region having a plurality of pixels on a semiconductor substrate, the solid state image pickup device provided with at least a light receiving unit and an amplifying portion amplifying photocharges from the light receiving unit in the pixel region, and further provided with a first semiconductor region for regulating potential of a well region, in which the amplifying portion is arranged, and a silicon nitride film arranged between the semiconductor substrate and a wiring layer so as to cover at least a part of the light receiving unit, wherein the silicon nitride film is not arranged on the first semiconductor region.
Moreover, the present invention is characterized by an optical system, a diaphragm limiting an amount of light passing the optical system, and the above-mentioned solid state image pickup device receiving the light passing the diaphragm.
Other features and advantages of the present invention will be apparent from the following description taken in conjunction with the accompanying drawings, in which like reference characters designate the same or similar parts throughout the figures thereof.
BRIEF DESCRIPTION OF THE DRAWINGS
FIG. 1 is a plan view of a first embodiment of the present invention;
FIG. 2 is a sectional view of the first embodiment of the present invention;
FIG. 3 is a sectional view of a second embodiment of the present invention;
FIG. 4 is a sectional view of a third embodiment of the present invention;
FIG. 5 is a plan view of the third embodiment of the present invention;
FIG. 6 is a sectional view of a fourth embodiment of the present invention;
FIG. 7 is a sectional view of a fifth embodiment of the present invention;
FIG. 8 is a plan view of the fifth embodiment of the present invention;
FIG. 9 is a view showing an example of the circuit block in case of applying a solid state image pickup device according to the present invention to a camera;
FIG. 10 is a sectional view showing the cross-sectional structure of prior art; and
FIG. 11 is a plan view showing the planar structure of the prior art.
The accompanying drawings, which are incorporated in and constitute a part of the specification, illustrate embodiments of the invention and, together with the description, serve to explain the principles of the invention.
DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS
In the following, the best embodiments for implementing the present invention are described with reference to the attached drawings.
First Embodiment
FIG. 1 is a plan view of a first embodiment of the present invention, and FIG. 2 is a sectional view of the first embodiment of the present invention.
The present embodiment is an image pickup device including photodiodes each composed of an N type semiconductor region 202 formed in a P type semiconductor region (well).
In FIGS. 1 and 2 , a reference numeral 101 denotes a well region connecting semiconductor region (P type semiconductor region). A reference numeral 102 denotes a photodiode to become a photoelectric conversion element. A reference numeral 103 denotes a transfer switch transferring charges from the photodiode 102 . A reference numeral 104 denotes a charge conversion unit for converting a signal charge into a voltage. A reference numeral 105 denotes a metal oxide semiconductor (MOS) transistor unit provided according to uses such as the resetting of the charge conversion unit and the amplification of a signal charge. The reference numeral 202 denotes the N type semiconductor region constituting the photodiode. In fact, an electrode is connected to the well electrode 101 through a contact hole. The well electrode 101 is formed for regulating the potential of a well in which an amplifying element for amplifying the signal charge is formed.
As shown in FIG. 2 , no element isolation regions such as the LOCOS are arranged between the well electrode 101 and the photodiode 102 . That is, the well electrode 101 is arranged in the same active region as the photodiode 102 .
On the other hand, an element isolation region 106 by the LOCOS is arranged between the MOS transistor units 105 .
In order to avoid a dark current originated in a defect of a LOCOS end, the N type semiconductor region 202 is arranged to be away from the LOCOS end.
According to the present embodiment, because no element isolation regions by the LOCOS is arranged between the well electrode 101 and the light receiving unit of the photodiode 102 , it becomes unnecessary to form any offset region for suppressing the dark current. Instead of the element isolation region, an offset region is formed between the N type semiconductor region 202 and the well electrode 101 .
The reason is that, when the N type semiconductor region 202 and the well electrode 101 are touched with each other directly, the touch becomes a cause of the dark current.
As a result, the space of the amount of the distance of the element isolation region 106 can be saved. The amount of the distance of the element isolation region 106 is 0.7 μm in the present embodiment.
Moreover, in the prior art, 2 μm 2 of the area has been required as the well region.
However, according to the present embodiment, because the active region for the well region is connected to the active region of the photodiode, the active region for the well region may satisfy to be 2 μm 2 or more in total, and it becomes possible that the area of the impurity region for the well region is even 0.64 μm 2 .
As a result, the space of 1 μm 2 or more can be decreased owing to the effect of the configuration.
Second Embodiment
FIG. 3 is a sectional view of a second embodiment of the present invention. The same reference characters as those in the first embodiment are given to the portions having the same functions as those of the first embodiment, and their descriptions are omitted.
The present embodiment differs from the first embodiment in that the present embodiment provides an image pickup device in which the buried photodiode 102 is formed in a P type semiconductor region.
The buried photodiode structure is constructed by arranging a P type semiconductor region 507 on the surface of the photodiode. As is apparent from the drawing, the well region is arranged up to a deeper position in the semiconductor substrate in comparison with the P type semiconductor region on the surface on the basis of a principal surface of the semiconductor substrate on which the photodiode is arranged, as a reference.
Also in the present embodiment, because the element isolation region 106 by the LOCOS is not arranged between the well electrode 101 and the photodiode 102 , it becomes unnecessary to form the offset region for suppressing the dark current, and an offset region is formed between the N type semiconductor region 202 and the well electrode 101 instead.
As an effect of the space saving according to the present embodiment, 1.7 μm can be obtained.
Third Embodiment
FIG. 4 is a sectional view of a third embodiment of the present invention.
The present embodiment differs from the second embodiment in that the present embodiment forms the P type semiconductor region to extend over the well region. That is, a surface P region 606 is arranged as shown in FIG. 5 . As is apparent from the drawings, the well region is arranged up to a deeper position in the semiconductor substrate in comparison with the P type semiconductor region on the surface on the basis of a principal surface of the semiconductor substrate on which the photodiode is arranged, as a reference.
By adopting such a configuration, it becomes possible to suppress the unevenness of dark currents.
The dark current of the photodiode 102 contains a generation current component generated from a defect existing in a depletion layer, and a diffusion current component generated from the density difference between electrons and holes in a PN junction surface. As one of the sources of the diffusion current component, there is the well electrode 101 .
That is, the position of the well electrode 101 and the impurity density from the well electrode 101 to the N type semiconductor region 202 is one of the primary factors determining the diffusion current component.
As the second embodiment, when a surface P region 307 is stopped at an X position in the drawing, i.e. when the surface P region 307 is formed as shown in FIG. 3 , the position of the surface P region may overlap or may not overlap with the well electrode 101 in a surface according to the registration accuracy (shifts in the X direction, the Y direction and the Θ direction) and the dispersion of dimensions. That is sometimes seen as unevenness of dark currents.
That is, the density of the area between the well electrode 101 and the N type semiconductor region 202 may differ to every pixel, and it may be seen as unevenness. The unevenness becomes several percents of order of magnitude. Although there is no problem when a dark current value fluctuates to this extent on the whole, the unevenness may become conspicuous when a dark current difference arises at some positions in the same image pickup device.
In the present embodiment, because the surface P type semiconductor region 307 is extended to the well electrode 101 , the dispersion of the density in the area between the well electrode 101 and the N type semiconductor region 202 in every pixel becomes nonexistent.
As a result, about 1.7 μm of pixel reduction can be obtained, and the dark current unevenness can be also suppressed.
Fourth Embodiment
FIG. 6 is a sectional view of a fourth embodiment of the present invention.
The present embodiment differs from the third embodiment in that no P + regions formed by a P + ion (for example, boron) implantation process for forming the sauce and the drain regions of a general MOS as the well electrode 101 are not used. Instead, after forming a contact hole for connecting a metal region with a semiconductor region, the well electrode 101 is formed by performing P + ion implantation using the contract hole as a mask. As is apparent from the drawing, the well region is arranged to a deeper position of the semiconductor substrate compared with the surface P type semiconductor region on the basis of a principal surface of the semiconductor substrate on which the photodiode is arranged, as a reference.
Thereby, the space of the electric contact and the margin of an active region of about 0.2 μm can be saved. As a result, 1.9 μm of the pixel reduction can be achieved.
Fifth Embodiment
FIG. 7 is a sectional view of a fifth embodiment of the present invention.
The feature of the present embodiment is to form a photodiode protection film 407 for protecting a photodiode from the damage of an etch back process of a lightly doped drain (LDD). As is apparent from the drawing, the well region is arranged to a deeper position of the semiconductor substrate compared with the surface P type semiconductor region on the basis of a principal surface of the semiconductor substrate on which the photodiode is arranged, as a reference.
In the present embodiment, the etch back process of the LDD is performed in a state in which a resist film is deposited at the position of a photodiode protection film 407 at the time of the LDD etch back.
FIG. 8 is a plan view of the present embodiment. A structure in which an oxide film for a LDD remains on a photodiode is obtained.
The photodiode protection layer is arranged in the region surrounded by an alternate long and short dash line 707 in the drawing.
In the present embodiment, the well electrode 101 is formed in an area bordered by the protection layer.
That is, a resist aperture portion for performing P + ion implantation for forming the well electrode 101 is made to extend also to a part of the photodiode protection layer.
Hereby, all of the active regions receiving etch back damages are made to be well regions.
According to the configuration of the present embodiment, space saving can be achieved, and the dark current unevenness described with regard to the third embodiment is also improved. The reason is as follows.
An active region having received damages owing to the registration accuracy (shifts in the X direction, the Y direction and the Θ direction) of the P + semiconductor region for a well region and the dispersion of dimensions in the well region surface may exist or may not exist in an area between the well electrode 101 and the N type semiconductor region 102 . Then, those damaged active regions can be seen as the unevenness of the dark current.
That is, because the damaged state of the semiconductor region between the well electrode 101 and the N type semiconductor region 202 differ from each other in every pixel, the damaged regions may be seen as the unevenness.
Because the resist aperture portion for the P + ion implantation for forming the well electrode 101 is made to extend also on a part of the photodiode protection layer from the reason mentioned above, the unevenness of the dark current can be more suppressed.
Sixth Embodiment
The photodiode protection layer is formed as follows in the fifth embodiment.
An 8 nm of a silicon oxide film, a 50 nm of silicon nitride film, and a 500 nm of a silicon oxide film are formed from the surface of the semiconductor in the order.
As a result, in addition to the effect of the fifth embodiment, the laminated structure of the silicon oxide film and the silicon nitride film performs an anti-reflection function, and the improvement in sensitivity can been also improved by about 20%.
Seventh Embodiment
FIG. 9 shows an example of a circuit block in the case of applying an image pickup device according to the present invention to a camera.
A shutter 1001 is provided before a photographing lens 1002 , and the shutter 1001 controls exposure. A light amount is controlled by a diaphragm 1003 as the need arises, and the light is made to perform image formation on an image pickup device 1004 .
A signal outputted from the image pickup device 1004 is processed by a signal processing circuit 1005 , and is converted into a digital signal from an analog signal by an A/D converter 1006 .
The operation processing of the digital signal outputted from the A/D converter 1004 is further performed by a signal processing unit 1007 .
The processed digital signal is stored in a memory 1010 , or is transmitted to an external apparatus through an external I/F unit 1013 .
The image pickup device 1004 , the image signal processing circuit 1005 , the A/D converter 1006 , and the signal processing unit 1007 are controlled by a timing generator 1008 , and also the whole system is controlled by a unit controlling whole and arithmetic operation unit 1009 .
In order to record an image on a recording medium 1012 , an output digital signal is recorded through an I/F unit controlling recording medium 1011 controlled by the unit controlling whole and arithmetic operation unit 1012 .
This application claims priority from Japanese Patent Application No. 2004-254362 filed on Sep. 1, 2004, which is hereby incorporated by reference herein.
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An object is to provide a solid state image pickup device and a camera which do not worsen a sensor performance in terms of an optical property, a saturated charge amount and the like. A solid state image sensor including a pixel region having a plurality of pixels includes at least a photodiode and an amplifying portion amplifying photocharges outputted from the photodiode in the pixel region, and further includes a well electrode for taking well potential of a well region in which the amplifying portion is arranged. Between the well electrode and the photodiode, no element isolation regions by an insulation film are arranged. Moreover, on the surface of a first semiconductor region in which the photodiode stores the charges, a second semiconductor layer of a conductivity type reverse to that of the first semiconductor region is arranged.
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BACKGROUND OF THE INVENTION
The present invention relates to a process for stabilization of the viscosity of wood pulps, that have been treated with ozone or ozone/oxygen during a bleaching sequence, at a level of materials corresponding to those that are obtained by the conventional chlorine bleach processes.
Bleaching of wood pulps at the present time takes place predominantly with the use of chlorine or chlorine-containing bleaching agents. However, oxygen-containing bleaching agents such as oxygen, ozone or hydrogen peroxide are being used increasingly. This is due to the undesirable pollution of waste water caused by release of chlorinated compounds.
It has been shown that the chlorine requirement for a conventional final bleach can be considerably reduced by the use of oxygen for predelignifications. However, the use of chlorine cannot be avoided completely.
Delignification with just oxygen or hydrogen peroxide produces only limited lignin degradation rates. If very drastic delignification conditions are used in the oxygen step, there is irreversible damage to the wood pulp.
The combined use of oxygen and ozone is necessary for intensification of the delignification. However, ozone is a very reactive and simultaneously nonselective bleaching agent. Thus, side reactions, such as the oxidation of wood pulp, cannot be prevented even with low ozone charge amounts. In this case, the resulting carbonyl groups elevate the sensitivity of wood pulp toward alkaline degradation. The alkaline extraction following the ozone treatment, which takes place in acidic medium, leads to a cleavage of cellulose chains and thus to a reduction of the viscosity and strength of the wood pulp in comparison to materials bleached with the use of chlorine. O. Kordsachia and R. Patt in the journal, Holzforschung 42, 203-209 (1988), report that the reduction of the average polymerization values caused by ozone treatment can be at least partially suppressed by the addition of sodium borohydride. However, this is possible only at low ozone dosages (0.5%) which yield modest brightnesses (86 (ISO)).
SUMMARY OF THE INVENTION
It is an object of the present invention to find a procedure by which, in comparison to materials bleached with the use of chlorine, almost no reduction of the viscosities at low ozone dosages occur. In addition, even at higher concentrations of ozone, only a slight drop in viscosity occurs. Wood pulps are obtained with a brightness of approximately 90 (ISO).
A further object of the present invention is a process for stabilization of the viscosity of wood pulp in association with an ozone or ozone/oxygen treatment. This process is characterized by the fact that the wood pulp is treated with 0.05 to 1 wt.-% formamidinesulfinic acid based on absolutely dry wood pulp. The process occurs at a pH-value of 8 to 12 and at a temperature of 40° to 90° C., preferably 50° to 80° C.
DETAILED DESCRIPTION OF THE INVENTION
Both alkaline- and acidic-produced sulfite wood pulps, as well as craft wood pulps, are suitable as a wood pulp for this process These pulps can be on a pine or hardwood basis.
The ozone or ozone/oxygen treatment is accomplished, according to the state of the art, in an acidic medium. Generally, the ozone concentration is 0.1 to 4% based on absolutely dry wood pulp The formamidinesulfinic acid is used in the alkaline extraction step. Additional equipment expense is not required
The stock density of the pulp lies between 5 and 10%, preferably between 8 and 12%.
The normal residence time in this step generally is sufficient to obtain stabilization of the viscosity
Additional bleaching steps can then be incorporated.
By means of the process according to the present invention, it is possible to use a chlorine-free bleach to obtain wood pulps that are almost indistinguishable in brightness, viscosity and strength from those obtained by the conventional process (i.e., the process operating with the use of chlorine). Even with high ozone dosages (˜3%), the differences are extremely small.
EXAMPLES
The percentage statements are based on absolutely dry wood pulp
1. Spruce sulfite paper pulp (kappa 18.0)
______________________________________(a) Conventional bleach according to C-E-D-HCharged Chemicals: stock density time temp.C 4% Cl.sub.2 3% 1 h 25° C.E 2% NaOH 10% 1.5 h 70° C.D 1% ClO.sub.2 (active chlorine) 10% 3 h 70° C.H 1% NaOCl 10% 3 h 40° C.Results: brightness 90.7 (ISO) viscosity 12.2 mPa s(b) Chlorine-free bleach according to EOP-Z-E-PCharged Chemicals: stock density time temp.EOP 1.8% NaOH 0.75% H.sub.2 O.sub.2 0.3 MPa O.sub.2 1.0% O.sub.2 10% 1 h 70° C.Z 1.0% O.sub.3 25% 0.25 h 30° C.E 1.0% NaOH 10% 1 h 50° C.P 1.0% H.sub.2 O.sub.2 0.7% NaOH 10% 3 h 75° C.Results: brightness 90.3 (ISO) viscosity 8.2 mPa s(c) Chlorine-free bleach according to EOP-Z-E (FAS)-PCharged Chemicals:EOPZ as in (b) stock density time temp.E (FAS) 1% NaOH 10% 1 h 50° C. 0.5% FASP as in (b)Results: brightness 90.5 (ISO), viscosity: 12.3 mPa s______________________________________
2. Pine craft pulp (kappa 33.2)
______________________________________(a) Conventional: CD-E-D-E-D stock density time temp.CD 7% Cl.sub.2 /0.7% ClO.sub.2 3% 1 h 25° C.E 2.8% NaOH 10% 1.5 h 60° C.D 3% O.sub.3 10% 3 h 65° C.E 1% NaOH 10% 1 h 65° C.D 1% ClO.sub.2 10% 3 h 70° C.Results: brightness 90.7 (ISO) viscosity 20.2 mPa sStrength at 20 SR: tear length 8.8 kmtearing resistance: 9.3 mN m.sup.2 /g(b) Chlorine-free bleach according to 0-Z-E-P stock density time temp. 0.5 Mpa O.sub.2O 5% NaOH, 0.3% MgSO.sub.4 10% 1.5 h 110° C.Z 3% O.sub.3 33% 25 min 30° C.E 1% NaOH 10% 1.5 h 60° C.P 2% H.sub.2 O.sub.2, 0.8% NaOH 0.2% MgSO.sub.4, 20% 2 h 75° C. 1% water glassResults: brightness 89.8 (ISO) viscosity 12.1 mPa sStrength at 20 SR: tear length 6.8 kmTearing resistance: 7.6 mN m.sup.2 /g(c) chlorine-free bleach with FAS in the E-stepE-step with 0.4% formamidinesulfinic acidResults: brightness 90.1 (ISO) viscosity 18.7 mPa sStrength at 20 SR: tear length 8.8 kmTearing resistance: 9.2 mN m.sup.2 /g______________________________________
3. Beech sulfite wood pulp (kappa 14.2)
______________________________________(a) Conventional bleach according to C-E-H-D stock density time temp.C 4.1% Cl.sub.2 3% 1 h 20° C.E 1.8% NaOH 10% 1.5 h 65° C.H 1.5% Na 10% 2 h 40° C.D 0.7% ClO.sub.2 10% 3 h 65° C.Results: brightness 89.1 (ISO)Strength at 25 SR: tear length 5.4 kmTear propagation resistance: 132 mNm/mViscosity: 12.1 mPa s; kappa: 0.8(b) Chlorine-free bleaching according to Z-E-P stock density time temp.Z 1.5% O.sub.3 35% 20 min 20° C.E 1.8% NaOH 10% 1.5 h 60° C.P 1.5% H.sub.2 O.sub.2, 1.1% NaOH 10% 2 h 65° C.Results: brightness 88.2 (ISO)Strength at 25 SR: tear length 4.7 kmTear propagation resistance: 98 mNm/mViscosity: 7.8 mPa s; kappa: 1.1(c) With FAS in the extraction stepZ as in (b)E as in (b)0.5% formamidinesulfinic acid in additionP as in (b)Results: brightness 88.7 (ISO)Strength at 25 SR: tear length 5.3 kmTear propagation resistance: 130 mNm/mViscosity: 11.2 mPa sKappa value: 1.1______________________________________
The letter symbols used herein; (e.g EOP, etc ) have well known meaning in the art.
Further variations and modifications of the foregoing invention will be apparent to those skilled in the art and are intended to be encompassed by the claims appended hereto.
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A process is described in which, by the addition of formamidinesulfinic acid in association with an ozone or ozone/oxygen treatment, the viscosity and strength of wood pulps are stabilized at the level that is obtained with use of conventional, chlorine-containing bleaching processes.
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FIELD OF THE INVENTION
[0001] The present invention relates generally to testing apparatuses, and more particularly to a performance testing apparatus for heat pipes.
DESCRIPTION OF RELATED ART
[0002] It is well known that a heat pipe is generally a vacuum-sealed pipe. A porous wick structure is provided on an inner face of the pipe, and phase changeable working media employed to carry heat is included in the pipe. Generally, according to where the heat is input or output, a heat pipe has three sections, an evaporating section, a condensing section and an adiabatic section between the evaporating section and the condensing section.
[0003] In use, the heat pipe transfers heat from one place to another place mainly by exchanging heat through phase change of the working media. Generally, the working media is a liquid such as alcohol or water and so on. When the working media in the evaporating section of the heat pipe is heated up, it evaporates, and a pressure difference is thus produced between the evaporating section and the condensing section in the heat pipe. The resultant vapor with high enthalpy rushes to the condensing section and condenses there. Then the condensed liquid reflows to the evaporating section along the wick structure. This evaporating/condensing cycle continually transfers heat from the evaporating section to the condensing section. Due to the continual phase change of the working media, the evaporating section is kept at or near the same temperature as the condensing section of the heat pipe. Heat pipes are used widely owing to their great heat-transfer capability.
[0004] In order to ensure the effective working of the heat pipe, the heat pipe generally requires testing before being used. The maximum heat transfer capacity (Qmax) and the temperature difference (AT) between the evaporating section and the condensing section are two important parameters in evaluating performance of the heat pipe. When a predetermined quantity of heat is input into the heat pipe through the evaporating section thereof, thermal resistance (Rth) of the heat pipe can be obtained from AT, and the performance of the heat pipe can be evaluated. The relationship between these parameters Qmax, Rth and ΔT is Rth=ΔT/Qmax. When the input quantity of heat exceeds the maximum heat transfer capacity (Qmax), the heat cannot be timely transferred from the evaporating section to the condensing section, and the temperature of the evaporating section increases rapidly.
[0005] A typical method for testing the performance of a heat pipe is to first insert the evaporating section of the heat pipe into a liquid at constant temperature; after a period of time the temperature of the heat pipe will become stable, then a temperature sensor such as a thermocouple, a resistance thermometer detector (RTD) or the like can be used to measure ΔT between the liquid and the condensing section of the heat pipe to evaluate the performance of the heat pipe. However, Rth and Qmax can not be obtained by this test, and the performance of the heat pipe can not be reflected exactly by this test.
[0006] Referring to FIG. 6 , a related performance testing apparatus for heat pipes is shown. The apparatus has a resistance wire 1 coiling round an evaporating section 2 a of a heat pipe 2 , and a water cooling sleeve 3 functioning as a heat sink and enclosing a condensing section 2 b of the heat pipe 2 . In use, electrical power controlled by a voltmeter and an ammeter flows through the resistance wire 1 , whereby the resistance wire 1 heats the evaporating section 2 a of the heat pipe 2 . At the same time, by controlling flow rate and temperature of cooling liquid entering the cooling sleeve 3 , the heat input at the evaporating section 2 a can be removed from the heat pipe 2 by the cooling liquid at the condensing section 2 b, whereby a stable operating temperature of adiabatic section 2 c of the heat pipe 2 is obtained. Therefore, Qmax of the heat pipe 2 and AT between the evaporating section 2 a and the condensing section 2 b can be obtained by temperature sensors 4 at different positions on the heat pipe 2 .
[0007] However, in the test, the related testing apparatus has the following drawbacks: a) it is difficult to accurately determine lengths of the evaporating section 2 a and the condensing section 2 b which are important factors in determining the performance of the heat pipe 2 ; b) heat transference and temperature measurement may easily be affected by environmental conditions; and, c) it is difficult to achieve sufficiently intimate contact between the heat pipe and the heat source and between the heat pipe and the heat sink, which results in uneven performance test results of the heat pipe. Furthermore, due to awkward and laborious assembly and disassembly in the test, the testing apparatus can be only used in the laboratory, and can not be used in the mass production of heat pipes.
[0008] In mass production of heat pipes, a large number of performance tests are needed, and the apparatus is used frequently over a long period of time; therefore, the apparatus not only requires good testing accuracy, but also requires easy and accurate assembly to the heat pipes to be tested. The testing apparatus affects the yield and cost of the heat pipes directly; therefore, testing accuracy, facility, speed, consistency, reproducibility and reliability need to be considered when choosing the testing apparatus. Therefore, the testing apparatus needs to be improved in order to meet the demand for mass production of heat pipes.
[0009] What is needed, therefore, is a high performance testing apparatus for heat pipes suitable for use in mass production of heat pipes.
SUMMARY OF THE INVENTION
[0010] A performance testing apparatus for a heat pipe in accordance with a preferred embodiment of the present invention comprises an immovable portion having a heating member located therein for heating an evaporating section of the heat pipe, and a movable portion capable of moving relative to the immovable portion. A receiving structure is defined between the immovable portion and the movable portion for receiving the evaporating section of the heat pipe therein. A concavo-convex cooperating structure is defined in the immovable portion and the movable portion for avoiding the movable portion from deviating from the immovable portion during the movement of the movable portion relative to the immovable portion to ensure the receiving structure being capable of receiving the heat pipe precisely. At least one temperature sensor is attached to at least one of the immovable portion and the movable portion for thermally contacting the heat pipe in the receiving structure for detecting temperature of the heat pipe.
[0011] Other advantages and novel features will become more apparent from the following detailed description of preferred embodiments when taken in conjunction with the accompanying drawings, in which:
BRIEF DESCRIPTION OF THE DRAWINGS
[0012] Many aspects of the present apparatus can be better understood with reference to the following drawings. The components in the drawings are not necessarily drawn to scale, the emphasis instead being placed upon clearly illustrating the principles of the present apparatus. Moreover, in the drawings, like reference numerals designate corresponding parts throughout the several views.
[0013] FIG. 1 is an assembled view of a performance testing apparatus for heat pipes in accordance with a first embodiment of the present invention;
[0014] FIG. 2 is an exploded, isometric view of the testing apparatus of FIG. 1 ;
[0015] FIG. 3A shows a movable portion of a performance testing apparatus in accordance with a second embodiment of the present invention;
[0016] FIG. 3B shows an immovable portion of the testing apparatus in accordance with the second embodiment of the present invention;
[0017] FIG. 4A shows a movable portion of a performance testing apparatus for heat pipes in accordance with a third embodiment of the present invention;
[0018] FIG. 4B shows an immovable portion of the testing apparatus in accordance with the third embodiment of the present invention;
[0019] FIG. 5A shows a movable portion of a performance testing apparatus for heat pipes in accordance with a forth embodiment of the present invention;
[0020] FIG. 5B shows an immovable portion of the testing apparatus in accordance with the forth embodiment of the present invention; and
[0021] FIG. 6 is a performance testing apparatus for heat pipes in accordance with related art.
DETAILED DESCRIPTION OF THE INVENTION
[0022] Referring to FIGS. 1 and 2 , a performance testing apparatus for heat pipes in accordance with a first embodiment of the present invention comprises an immovable portion 20 and a movable portion 30 movably mounted on the immovable portion 20 .
[0023] The immovable portion 20 has good heat conductivity and is held on a platform of a supporting member such as a testing table or so on. A heating member (not labeled) such as an immersion heater, resistance coil, quartz tube and Positive temperature coefficient (PTC) material or the like is embedded in the immovable portion 20 . The immovable portion 20 defines a hole (not shown) through a center of a bottom thereof. In the case, the heating member is an elongated cylinder. The heating member is accommodated in the hole of the immovable portion 20 from bottom of the immovable portion 20 . Two spaced wires 220 of the heating member extend from an end of the heating member to connect with a power supply (not shown). The immovable portion 20 has a heating groove 24 defined in a top face thereof, for receiving an evaporating section of the heat pipe to be tested therein. Two temperature sensors 26 are inserted into the immovable portion 20 at two opposite sides of the heating member from the bottom of the immovable portion 20 so as to position detecting portions (not labeled) of the sensors 26 in the heating groove 24 . The detection portions of the sensors 26 are capable of automatically contacting the heat pipe in order to detect a temperature of the evaporating section of the heat pipe. In order to prevent heat in the immovable portion 20 from spreading to the supporting member, an insulating plate 28 is disposed on the supporting member for thermally insulating the testing apparatus from the supporting member.
[0024] The movable portion 30 , corresponding to the heating groove 24 of the immovable portion 20 , has a positioning groove 32 defined therein, whereby a testing channel 50 is cooperatively defined by the heating groove 24 and the positioning groove 32 when the movable portion 30 moves to reach the immovable portion 20 . Thus, an intimate contact between the heat pipe and the movable and immovable portions 30 , 20 defining the channel 50 can be realized, thereby reducing heat resistance between the heat pipe and the movable and immovable portions 30 , 20 . Two temperature sensors 36 are inserted into the movable portion 30 from a top thereof to reach a position wherein detecting portions (not labeled) of the sensors 36 are located in the positioning groove 32 . The detecting portions are capable of automatically contacting the heat pipe to detect the temperature of the evaporating section of the heat pipe.
[0025] The movable portion 30 extend two elongated bars 35 downwardly and integrally from a bottom face thereof towards the immovable portion 20 . The elongated bars 35 are located at two sides of the groove 32 of the movable portion 30 . Corresponding to the bars 35 of the movable portion 30 , the immovable portion 20 defines two slots 25 in a top face thereof. The bars 35 are slidably received in the corresponding slots 25 . The bars 35 are always received in the slots 25 when the movable portion 30 moves toward the immovable portion 20 to reach a position wherein the bottom face of the movable portion 30 contacts the top face of the immovable portion 20 . The bars 35 and the slots 25 concavo-convexly cooperate to avoid the movable portion 30 from deviating from the immovable portion 20 during test of the heat pipes, thereby ensuring the grooves 24 , 32 of the immovable, movable portions 20 , 30 to precisely align with each other. Accordingly, the channel 50 can be accurately formed for precisely receiving the heat pipe therein for test.
[0026] The channel 50 as shown in the preferred embodiment has a circular cross section enabling it to receive the evaporating section of the heat pipe having a correspondingly circular cross section. Alternatively, the channel 50 can have a rectangular cross section where the evaporating section of the heat pipe also has a flat rectangular configuration.
[0027] In order to ensure that the heat pipe is in close contact with the movable and immovable portions 30 , 20 , a supporting frame 10 is used to support and assemble the immovable and movable portions 20 , 30 . The immovable portion 20 is fixed on the supporting frame 10 . A driving device 40 is installed on the supporting frame 10 to drive the movable portion 30 to make accurate linear movement relative to the immovable portion 20 along a vertical direction, thereby realizing the intimate contact between the heat pipe and the movable and immovable portions 30 , 20 . In this manner, heat resistance between the evaporating section of the heat pipe and the movable and immovable portions 30 , 20 can be minimized.
[0028] The supporting frame 10 comprises a seat 12 . The seat 12 comprises a first plate 14 at a top thereof and two feet 120 depending from the first plate 14 . A space 122 is defined between the two feet 120 of the seat 12 for extension of wires of the temperature sensors 26 and the wires 220 of the heating member. The supporting frame 10 has a second plate 16 hovers over the first plate 14 . Pluralities of supporting rods 15 interconnect the first and second plates 14 , 16 for supporting the second plate 16 above the first plate 14 . The seat 12 , the second plate 16 and the rods 15 constitute the supporting frame 10 for assembling and positioning the immovable and movable portions 20 , 30 therein. In order to prevent heat in the immovable portion 20 from spreading to the first plate 14 , the immovable portion 20 is positioned in a pond 285 defined in a top face of the insulating plate 28 . The first plate 14 and the insulating plate 28 define corresponding through holes 140 , 280 for the wire 220 of the heat member of the immovable portion 20 to extend therethrough to connect with the power supply, and spaced apertures 142 , 282 to allow wires of the temperature sensors 26 to extend therethrough to connect with a monitoring computer (not shown).
[0029] The driving device 40 in this preferred embodiment is a step motor, although it can be easily apprehended by those skilled in the art that the driving device 40 can also be a pneumatic cylinder or a hydraulic cylinder. The driving device 40 is installed on the second plate 16 of the supporting frame 10 . The driving device 40 is fixed to the second plate 16 above the movable portion 30 . A shaft (not labeled) of the driving device 40 extends through the second plate 16 of the supporting frame 10 . The shaft has a threaded end (not shown) threadedly engaging with a bolt 42 secured to a board 34 of the movable portion 30 . The board 34 is fastened to the movable portion 30 . When the shaft rotates, the bolt 42 with the board 34 and the movable portion 30 moves upwardly or downwardly. Two through apertures 342 are defined in the board 34 of the movable portion 30 to allow wires (not labeled) of the temperature sensors 36 to extend therethrough to connect with the monitoring computer. In use, the driving device 40 accurately drives the movable portion 30 to move linearly relative to the immovable portion 20 . For example, the movable portion 30 can be driven to depart a certain distance such as 5 millimeters from the immovable portion 20 to facilitate the insertion of the evaporating section of the heat pipe being tested into the channel 50 or withdrawn from the channel 50 after the heat pipe has been tested. In other hand, the movable portion 30 can be driven to move toward the immovable portion 20 to thereby realize an intimate contact between the evaporating section of the heat pipe and the immovable and movable portions 20 , 30 during the test. Accordingly, the requirements for testing, i.e. accuracy, ease of use and speed, can be realized by a testing apparatus in accordance with the present invention.
[0030] It can be understood, positions of the immovable portion 20 and the movable portion 30 can be exchanged, i.e., the movable portion 30 is located on the first plate 14 of the supporting frame 10 , and the immovable portion 20 is fixed to the second plate 16 of the supporting frame 10 , and the driving device 40 is positioned to be adjacent to the movable portion 20 . Alternatively, the driving device 40 can be installed to the immovable portion 20 . Otherwise, each of the immovable and movable portions 20 , 30 may have one driving device 40 installed thereon to move them toward/away from each other.
[0031] In use, the evaporating section of the heat pipe is received in the channel 50 when the movable portion 30 moves away from the immovable portion 20 , with the bars 35 of the movable portion 30 sliding in the slots 25 of the immovable portion 20 . The evaporating section of the heat pipe is put in the heating groove 24 of the immovable portion 20 . Then the movable portion 30 moves toward the immovable portion 20 with the bars 35 sliding in the slots 25 until the evaporating section of the heat pipe is tightly fitted into the channel 50 . The sensors 26 , 36 are in thermal contact with the evaporating section of the heat pipe; therefore, the sensors 26 , 36 work to accurately send detected temperatures from the evaporating section of the heat pipe to the monitoring computer. Based on the temperatures obtained by the plurality of sensors 26 , 36 , an average temperature can be obtained by the monitoring computer very quickly; therefore, performance of the heat pipe can be quickly decided.
[0032] Referring to FIGS. 3A and 3B , a movable portion 30 and an immovable portion 20 of a performance testing apparatus in accordance with a second embodiment of the present invention are shown. Different from the first embodiment, the movable portion 30 defines two slots 35 a at two opposite sides of the groove 32 thereof. The immovable portion 20 extends two bars 25 a slidably received in corresponding slots 35 a of the movable portion 30 .
[0033] Referring to FIGS. 4A and 4B , a movable portion 30 and an immovable portion 20 of a performance testing apparatus in accordance with a third embodiment of the present invention are shown. Different from the first embodiment, the movable portion 30 has a plurality of cylindrical posts 35 b extending downwardly and integrally from a bottom face thereof towards the immovable portion 20 . The cylindrical posts 35 b are evenly located at two sides of the groove 32 of the movable portion 30 . Corresponding to the posts 35 b of the movable portion 30 , the immovable portion 20 has a plurality of positioning holes 25 b defined in a top face thereof. The posts 35 b are slidably inserted into the corresponding holes 25 b. The posts 35 b are always received in the holes 25 b when the movable portion 30 moves relative to the immovable portion 20 .
[0034] Referring to FIGS. 5A and 5B , a movable portion 30 and a immovable portion 20 of a performance testing apparatus in accordance with a forth embodiment of the present invention are shown. Different from the third embodiment, the movable portion 30 defines a plurality of holes 35 c at two opposite sides of the groove 32 thereof while the immovable portion 20 extends a plurality of posts 25 c slidably received in corresponding holes 35 c of the movable portion 30 .
[0035] Additionally, in the present invention, in order to lower cost of the testing apparatus, the movable portion 30 , the insulating plate 28 , and the board 34 can be made from low-cost material such as PE (Polyethylene), ABS (Acrylonitrile Butadiene Styrene), PF(Phenol-Formaldehyde), PTFE (Polytetrafluoroethylene) and so on. The immovable portion 20 can be made from copper (Cu) or aluminum (Al). The immovable portion 20 can have silver (Ag) or nickel (Ni) plated on a top face thereof defining the groove 24 to prevent oxidization of the top face.
[0036] It is believed that the present embodiments and their advantages will be understood from the foregoing description, and it will be apparent that various changes may be made thereto without departing from the spirit and scope of the invention or sacrificing all of its material advantages, the examples hereinbefore described merely being preferred or exemplary embodiments of the invention.
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A performance testing apparatus for a heat pipe includes an immovable portion having a heating member located therein for heating an evaporating section of the heat pipe, and a movable portion capable of moving relative to the immovable portion. A receiving structure is defined between the immovable portion and the movable portion for receiving the evaporating section of the heat pipe therein. A concavo-convex cooperating structure is defined in the immovable portion and the movable portion for avoiding the movable portion from deviating from the immovable portion to ensure the receiving structure being capable of receiving the heat pipe precisely. At least one temperature sensor is attached to at least one of the immovable portion and the movable portion for detecting temperature of the heat pipe.
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BACKGROUND OF THE INVENTION
This invention relates to a sewing machine, particularly to a sewing machine in which at least one pattern is selected from a storage apparatus storing multiple patterns, the arrangement of at least two selected patterns is stored, the stored arrangement is sequentially read, a sewing mechanism is driven, and the selected pattern is stitched.
A related-art sewing machine can stitch a pattern such as a name of a student or the student's school name on fabric when an operator repeatedly operates numeral keys to select characters by combining the characters to form the names.
In the related-art sewing machine, stitch data for each pattern is stored beforehand in a ROM of a microcomputer provided in the sewing machine so that the sewing mechanism of the sewing machine is driven to stitch the pattern on fabric. When the operator repeatedly enters input numbers with the numeral keys, a pattern number representing the pattern designated by the input number is arranged and stored in a RAM. By reading the pattern numbers sequentially from the RAM, the stitch data corresponding to the pattern numbers is sequentially read from the ROM. Consequently, the sewing mechanism of the sewing machine is driven and the pattern is formed on fabric.
However, in this related-art sewing machine, when a new arrangement of the patterns is designated, the new pattern number is stored in the RAM. Therefore, every time a new pattern is selected, the operator must again operate the numeral keys to enter the arrangement of the patterns into the RAM. The operation of entering the pattern is thus troublesome. For example, when power source is cut, the pattern number stored in the RAM disappears, and the operator must again operate the numeral keys to enter the pattern. Similarly, when the same pattern is formed on fabric many times, the pattern must be entered every time the pattern is formed. The operation of entering the pattern is thus time-consuming.
When the pattern number of the pattern is stored in a nonvolatile memory unit for reuse instead of in volatile RAM in the related-art device, the troublesome input operation is saved should power be cut. However, patterns for only one use are stored in the nonvolatile memory unit.
SUMMARY OF THE INVENTION
One object of this invention is to provide a sewing machine in which, when a patterns for repeated use are entered, whether the arrangement of the patterns is stored in a nonvolatile memory unit can be confirmed on a display. When the patterns are thus entered and stored in a nonvolatile memory unit, the patterns can repeatedly be formed on fabric regardless of the turning on or off of a power source.
This object is attained by a sewing machine having a structure as shown in FIG. 1. The sewing machine comprises a pattern-data storing means M1 for storing multiple patterns, a pattern-selecting means M2 for selecting at least two patterns from the pattern-data storing means M1, a pattern-storing means M3 for storing the arrangement of the patterns selected by the pattern-selecting means M2, a display means M4 for displaying the arrangement of the patterns stored in the pattern-storing means M3, a sewing means M5, and a control means M6 for sequentially reading the arrangement of the patterns from the pattern-storing means M3, driving the sewing means M5, and forming the pattern. The sewing machine further comprises a nonvolatile-storing means M7 for storing the arrangement of the patterns in nonvolatile condition, and a pattern-reading means M8 for developing the arrangement of the patterns stored in the nonvolatile-storing means M7 into the pattern-storing means M3. The display means M4 comprises a selected-mode display means M9 for displaying that the pattern-selecting means M2 is in a writing mode, when the pattern-selecting means M2 selects the patterns, and when the patterns are written in the nonvolatile-storing means M7.
In the above-constructed sewing machine, the pattern-selecting means M2 selects at least two patterns from the pattern-data storing means M1. The arrangement of the selected patterns is stored in the pattern-storing means M3. The stored arrangement of the patterns in the pattern-storing means M3 can be stored in the nonvolatile-storing means M7. When the pattern-selecting means M2 selects the patterns to be written into the nonvolatile-storing means M7, the selected-mode display means M9 provided in the display means M4 shows that the pattern-selecting means M2 is in the writing mode. The operator confirms with the display of the writing mode whether the selected patterns are for only one use or whether the selected patterns are to be stored in the nonvolatile-storing means M7.
Through specified processes, the pattern-reading means M8 develops the arrangement of the patterns stored in the nonvolatile-storing means M7 into the pattern-storing means M3. The control means M6 sequentially reads the arrangement of the patterns developed in the pattern-storing means M3 and drives the sewing means M5 to form the arrangement of the pattern on fabric.
BRIEF DESCRIPTION OF THE DRAWINGS
FIG. 1 is a block diagram showing an illustration of the fundamental structure of this invention.
FIG. 2 is an external view of a sewing machine for an embodiment of this invention.
FIG. 3 is a block diagram of an electronic controller for the embodiment of this invention.
FIGS. 4A, 4B and 4C are diagrams showing data stored in the storage region of a ROM, a RAM and an EEPROM, respectively.
FIGS. 5A, 5B, 5C, 5D and 5E are flowcharts showing an illustration of processes the electronic controller executes.
FIGS. 6A, 6B, 6C, 6D, 6E, 6F, 6G, 6H and 6I are explanatory diagrams showing the display shown at each process.
DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENT
A sewing machine shown in FIG. 2 automatically forms a pattern such as names and other characters in response to instructions entered by means of operation keys 1 and a start switch 7 arranged on the front surface of a casing. The operation keys 1 are used for selecting the pattern. The start switch 7 is provided near a needle 3 and a feed dog 5 and is used for starting the formation of a selected pattern. A display 9 for showing the selected pattern and a reference panel 11 for indicating the selection of patterns to assist the selecting of the pattern.
The operation keys 1 comprise ten numeral keys 13, a start/end key 15, a plus key 17, and a cancel key 19. The pattern is selected by pressing the numeral keys 13 and entering a two-digit number. By pressing the start/end key 15, the selected pattern is stored. When a combined pattern is selected, the plus key 17 is pressed. The cancel key 19 is pressed for canceling the selected pattern. As shown in FIG. 3, the display 9 comprises an LCD 46. Dot-matrix characters are displayed on the LCD 46 corresponding to the number or the pattern designated with the numeral keys 13 in designating order.
The reference panel 11 show characters, symbols, or other shapes corresponding to the two-digit number entered with the numeral keys 13. In this embodiment, two-digit numbers 01 through 94 correspond to ordinary patterns such as the letters of the alphabet. An operator can combine characters, symbols, and other shapes and store the combined pattern into a nonvolatile memory unit. Two digit numbers 95 through 99 are used when the operator writes and reads the combined pattern. This combined pattern is hereinafter referred to as a message pattern. Reference panel 11 indicates that the two-digit numbers 95 through 99 are for creating message patterns.
In response to the instructions entered as described above, an electronic controller 20 controls the sewing mechanism of the sewing machine.
As shown in FIG. 3, the electronic controller 20 comprises a known CPU 21, ROM 23, RAM 25, input interface 27, output interface 29, and EEPROM 31. The EEPROM is an acronym for Electrically Erasable and Programmable ROM, and another term for EAROM (Electrically Alterable ROM). The EEPROM 31 is used as the nonvolatile storage apparatus and is connected via a bus 33 with the other components of the electronic controller 20. The numeral keys 13, the start/end key 15, the plus key 17, the cancel key 19, and the start switch 7 are connected to the input interface 27. A motor drive unit 39, an actuator drive unit 45, and an LCD drive circuit 47 are connected to the output interface 29. The motor drive unit 39 drives a sewing machine motor 37. The actuator drive unit 45 drives a needle actuator 41 for oscillating the needle 3 and a feed-dog actuator 43 for driving the feed dog 5. The LCD drive circuit 47 drives the LCD 46.
The electronic controller 20 performs a series of operations according to the program stored in the ROM 23. The pattern is selected corresponding to the number entered with the numeral keys 13, and the selected pattern is automatically formed on fabric. The ROM 23, the RAM 25 and the EEPROM 31, respectively, store specified data as follows.
Stitch data for each pattern is stored beforehand in the ROM 23 so that the motor drive unit 39 and the actuator drive unit 45 are driven to form stitches. As shown in FIG. 4A, the stitch data required for forming a character or a symbol is assembled into a set. The set of the stitch data is specified as a pattern having a pattern number Nptn.
The RAM 25 comprises a pattern number storage region for storing the pattern numbers Nptn. As shown in FIG. 4B the pattern numbers Nptn are arranged and stored. The value of a combination pointer P specifies each pattern number Nptn.
The EEPROM 31 comprises a nonvolatile storage region for storing the arrangement of the pattern numbers Nptn. As shown in FIG. 4C the pattern numbers Nptn are arranged and stored group by group. The groups of the pattern numbers Nptn, respectively, have a specified group number Ngrp. The arrangement of the groups of the pattern numbers Nptn stored in the EEPROM 31 corresponds to the arrangement of the pattern numbers Nptn stored in the RAM 25. In this embodiment, since the group numbers Ngrp are provided from 0 through 4, five groups of the pattern numbers Nptn may be arranged and stored. In the electronic controller 20 the group numbers Ngrp from 0 through 4 correspond, respectively, to the numbers 95 through 99 entered with the numeral keys 13.
The series of operations performed by the electronic controller 20 in response to key operations will now be explained.
After a power switch is turned on and initialization is carried out, the electronic controller 20 starts the pattern-selecting routine shown in the flowchart of FIG. 5A. In the pattern-selecting routine, the input of an operation key is first read, and the operation key is identified. By repeating subroutines corresponding to respective functions of the operation keys, the electronic controller 20 controls the sewing machine in response to the instructions given with the operation keys.
At step S100 the input of an operation key is first read, and step S110 determines whether the operation key corresponds to the numeral key 13. When the numeral key 13 is operated, step S120 executes a subroutine for writing and reading the pattern number. In this subroutine the pattern number corresponding to the number entered with the numeral keys 13 is stored in the RAM 25. Alternatively, the pattern number of the pattern related with the message pattern is written into or read from the EEPROM 31.
On the other hand, if at step S110 the numeral key 13 is not operated, step S130 determines whether the start/end key 15 is operated or not. When the start/end key 15 is operated, step S140 executes a subroutine for starting and finishing writing the pattern number into the EEPROM 31. If at step S130 the start/end key 15 is not operated, step S150 determines whether the plus key 17 is operated or not. When the plus key 17 is operated, step S160 sets a plus flag Fpls. The setting of the plus flag Fpls indicates that character inputs and symbol inputs are combined into a pattern. Specifically, the pattern number Nptn written into the RAM 25 or the EEPROM 31 at step S120 is added onto the last stored pattern number Nptn.
When step S150 determines that the plus key 17 is not operated, step S170 determines whether the cancel key 19 is operated or not. When the cancel key 19 is operated, step S180 executes a subroutine for canceling the pattern number written into the RAM 25 or the EEPROM 31 at step S120.
As aforementioned, the electronic controller 20 determines the type of the operation key, repeatedly executes the subroutine corresponding to the function of the operation key, and controls the sewing mechanism of the sewing machine according to the instructions given by the operator.
Types of the operation executed by the electronic controller 20 will now be explained.
OPERATION A
When a certain pattern needs to be formed once, the electronic controller 20 executes a process as follows. For the following process, the numeral keys 13 are operated in combination with the plus key 17.
When the operator presses the numeral keys 13, step S110 determines that the numeral keys 13 operate, and the process goes to step S120, which executes the subroutine for writing and reading the pattern number.
As shown in the flowchart of FIG. 5B, in this subroutine step S200 specifies a two-digit input number mn entered with the numeral keys 13.
Subsequently, step S210 determines whether the plus flag Fpls is set to one or not. Since the pattern is the first pattern entered with the numeral keys 13, the plus flag Fpls has not yet been set. Therefore, the answer at step S210 is negative, and the process goes to step S220 at which the combination pointer P is reset to a value FF. The combination pointer P designates the combining sequence of the pattern number Nptn of the pattern corresponding to the input number mn.
Subsequently, step S230 determines whether the input number mn corresponds to a number from 95 through 99. Specifically, step 230 determines whether the process is related to message pattern. Since the arrangement of the patterns required once is entered in this type of operation, the input number mn entered with the numeral keys 13 is other than from 95 through 99. Therefore, the answer at step S230 is negative.
Subsequently, step S240 increments the combination pointer P, and step S250 calculates the number Nptn(mn) of the pattern corresponding to the input number mn. Such specifying of the pattern number Nptn determines the set of stitch data stored in the ROM 23 that is required for forming the pattern corresponding to the input number mn.
After the calculated pattern number Nptn(mn) is obtained at step S250, at step S260 the calculated pattern number Nptn(mn) is stored into a memory unit M(P) at the address specified by the value of the combination pointer P in the pattern number storage region of the RAM 25.
Subsequently, step S270 determines whether a message flag Fmsg is set to one. The message flag Fmsg is usually set or reset with the start/end key 15 at step S140. Since the arrangement of the patterns required once is entered for this type of the operation, the message flag Fmsg is reset. The answer at step S270 is, therefore, negative. The subroutine for writing and reading the pattern number at step S120 thus ends.
As aforementioned, the pattern number Nptn of the pattern entered with the numeral keys 13 is stored in the RAM 25. On the other hand, the electronic controller 20 performs separate processes to display the pattern number Nptn stored in the RAM 25 on the display 9 so that the operator can confirm the pattern number Nptn on the display 9. As illustrated in FIG. 6A, the display 9 first shows the input number mn entered with the numeral keys 13 for several seconds. Subsequently, as illustrated in FIG. 6B, the outline of the pattern corresponding to the input number mn is shown on the display 9.
When the plus key 17 is pressed, the electronic controller 20 sets the plus flag Fpls to one at step S160. The electronic controller 20 executes separate processes to show the symbol of plus subsequent to the outline of the pattern as illustrated in FIG. 6C.
Subsequently, when the numeral keys 13 are operated, the electronic controller 20 again executes the subroutine for writing and reading the pattern number in FIG. 5B. Step S210 determines that the plus flag Fpls is set to one, thereby skipping step S220 for resetting the combination pointer P. Since the input number mn is other than from 95 through 99, the answer at step S230 is negative. Step S240 increments the combination pointer P and step S250 calculates the pattern number Nptn(mn) from the input number mn.
Subsequently, at step S260 the calculated pattern number Nptn(mn) is stored into the memory unit M(P) at the address specified by the increased value of combination pointer P in the pattern number storage region of the RAM 25. The calculated pattern number Nptn(mn) is thus stored subsequently to the last stored pattern number. Since the message flag Fmsg is reset to zero, the answer at step S270 is negative. The subroutine thus ends.
When the operator enters the number with the numeral keys 13 and repeatedly presses the plus key 17, the electronic controller 20 repeats the aforementioned subroutine and stores the pattern number Nptn into the RAM 25 in input order as shown in FIG. 4B.
The electronic controller 20 executes separate processes to show the outline of the second entered pattern instead of the symbol of plus on the display 9 as illustrated in FIG. 6D.
Subsequently, when the operator presses the start switch 7, the electronic controller 20 finishes the aforementioned pattern-selecting routine and starts a pattern-forming routine. In the pattern-forming routine, the pattern numbers Nptn, which are arranged and stored in each memory unit M of the pattern number storage region in the RAM 25, are read in order from the smallest value of the combination pointer P. The set of the stitch data corresponding to the read pattern numbers Nptn is read from the ROM 23. The sewing mechanism of the sewing machine is driven, thereby forming the input pattern in input order.
OPERATION B
The operation of the electronic controller 20 for storing the message pattern will now be explained. To store the message pattern, the operator operates the start/end key 15 in addition to the numeral keys 13 and the plus key 17.
First, a number indicating that the message pattern to be stored is selected from 95 through 99 and entered with the numeral keys 13.
When the selected number is entered, the electronic controller 20 shifts its processes to those for the subroutine for writing and reading pattern number shown in FIG. 5B. Step S230 determines whether the input number mn corresponds to a number from 95 through 99.
Subsequently, at step S280 the input number mn is determined as a message number Nmsg. At step S290 value mn-95 is calculated as the group number Ngrp to be stored in the EEPROM 31 by subtracting 95 from the input number mn.
After the group number Ngrp is obtained, at step S300 the group of the pattern numbers Nptn specified and stored by the group number Ngrp in the storage region of the EEPROM 31 is read.
Subsequently, at step S310 the read group of pattern numbers Nptn is copied into each memory unit M of the pattern number storage region in the RAM 25. At step S320 the number of the pattern numbers Nptn composing the read group is registered as the value of the combination pointer P, and the process once ends.
When the processes at steps S280 through S320 result in nothing stored in the EEPROM 31, no pattern numbers Nptn are copied into the RAM 25, and the value of the combination pointer P resets to the value FF at step S220.
When a number from 95 through 99 is entered with the numeral keys 13, the process for determining the message number Nmsg and other processes are executed as aforementioned. On the other hand, the electronic controller 20 shows the message number Nmsg on the display 9 as illustrated in FIG. 6E, which indicates that the operation processes are in the mode related with the message pattern.
Subsequently, when the start/end key 15 is pressed, the electronic control unit 20 shifts its processes to those for the subroutine for starting and finishing writing the pattern number at step S140.
In this subroutine, as shown in FIG. 5C, step S330 determines whether the message flag Fmsg is set to one or not. When a number from 95 through 99 is entered with the numeral keys 13, the message flag Fmsg is not set to one. Therefore, the answer at step S330 is negative, and the message pattern can be stored. At step S340 the message flag Fmsg is set to one.
While the electronic controller 20 carries out the above-mentioned subroutine, the electronic controller 20 repeatedly executes a reversal display routine shown in the flowchart of FIG. 5E. First, step S500 determines whether the message flag Fmsg is set to one or not. After the start/end key 15 is pressed, the message flag Fmsg is set to one. Step S510 sets a flag Frev to one for reversing the display of the message number Nmsg on the display 9, and the process ends. When the flag Frev is thus set to one, the electronic controller 20 executes a not-shown process, thereby reversing the display of the message number Nmsg on the display 9 as illustrated in FIG. 6F.
As aforementioned, when any number from 95 through 99 is entered by pressing the number keys 13 and the start/end key 15, the display of the message number Nmsg is reversed. The reversed display of the message number Nmsg indicates that the present-selected mode is for writing the pattern number Nptn of the selected pattern into the EEPROM 31. In the same way as explained in OPERATION A, the numeral keys 13 and the plus key 17 are alternately operated, and the pattern number Nptn corresponding to the input number mn is stored into the RAM 25 and the EEPROM 31 in input order.
Specifically, the electronic controller 20 executes the subroutine for writing and reading the pattern number as shown in the flowchart of FIG. 5B. At step S260 the calculated pattern number Nptn(mn) corresponding to the input number mn entered with the numeral keys 13 is stored in the memory unit M(P) at the address specified by the combination pointer P in the pattern number storage region in the RAM 25. Step S270 then determines whether the message flag Fmsg is set to one. Subsequently, at step S350 the same pattern number Nptn(mn) as the one stored into the RAM 25 at step S260 is written into a nonvolatile memory unit MEP(Ngrp,P) at an address specified by the group number Ngrp and the combination pointer P in the EEPROM 31.
The electronic controller 20 executes a separate process and shows on the display 9, as illustrated in FIG. 6G, the outline of the pattern corresponding to the input number mn subsequently to the reversed display of the message number Nmsg.
The routine for writing and reading the pattern number thus ends. When the plus key 17 is further pressed and the numeral keys 13 are pressed to enter the input number mn, the calculated pattern number Nptn(mn) corresponding to the input number mn is stored into the memory unit M(P) at the address specified by the increased value of the combination pointer P in the RAM 25. At step S350 the same pattern number Nptn(mn) is written into the nonvolatile memory unit MEP(Ngrp,P) at the address specified by the group number Ngrp and the increased value of the combination pointer P in the EEPROM 31.
Through the aforementioned processes, the pattern number Nptn is stored into the RAM 25 and the EEPROM 31 in input order.
On the other hand, the electronic controller 20 executes separate processes to show the outline of the second entered pattern on the display 9. As illustrated in FIG. 6H the second entered pattern is subsequent to the reversed display of the message number Nmsg and the first entered pattern on the display 9.
When the start/end key 15 is pressed again, the subroutine for starting and finishing writing the pattern number in FIG. 5C starts. Since the message pattern has been stored, step S330 determines that the message flag Fmsg is set to one. Subsequently, at step S360 the message flag Fmsg is reset to zero, thereby finishing writing the pattern number.
After the message pattern has been stored, the electronic controller 20 executes the reversal display routine as shown in the flowchart of FIG. 5E. First, it is determined at step S500 that the message flag Fmsg is not set to one. At step S520 the reversal display flag Frev resets to zero. The electronic controller 20 executes the display routine not shown, and switches the reversal display to the ordinal display of the message number Nmsg, as illustrated in FIG. 6I.
As aforementioned, the operator enters either number from 95 through 99 with the numeral keys 13, and presses the start/end key 15. On the other hand, the operator can confirm that the reversal display of the message number Nmsg is shown on the display 9 and that the selected mode is for writing the selected pattern number Nptn in the EEPROM 31. The operation of the numeral keys 13 and the plus key 17 is thus repeated. Every time the number is entered with the numeral keys 13, as shown in FIG. 4C, the pattern number Nptn is written into the EEPROM 31, the region of the group number Ngrp first selected by entering either number from 95 through 99 with the numeral keys 13. When the start/end key 15 is pressed at last, the processes for writing the message pattern end.
OPERATION C
To stitch the message pattern registered through the processes of OPERATION B on fabric, the electronic controller 20 carries out the following processes.
When either number from 95 through 99 is entered with the numeral keys 13 for the group number Ngrp at which the desired message pattern is registered, the electronic controller 20 starts the subroutine for writing and reading the pattern number Ngrp in FIG. 5B.
It is determined at step S230 that the input number mn corresponds to either number from 95 through 99.
Subsequently, at step S280 the input number mn is set as the message number Nmsg, and at step S290 the value mn-95 is calculated as the group number Ngrp in the EEPROM 31 by subtracting 95 from the input number mn.
After the group number Ngrp is obtained, at step S300 the group of the pattern numbers Nptn is read from the address specified by the group number Ngrp in the EEPROM 31.
At step S310, the group of the pattern numbers Nptn read at step S300 is copied into each memory unit M of the pattern number storage region in the RAM 25. The respective pattern numbers Nptn in reading order are stored into the memory unit M(P) specified by the combination pointer P in the RAM 25 in order from the smallest value of the combination pointer P.
At step S320 the number of the pattern numbers Nptn in the group read at step S300 is registered as the value of the combination pointer P, and the process ends.
In the same way as the processes for storing the message pattern, the electronic controller 20 executes the processes for displaying the message pattern. As illustrated in FIG. 6I, the display 9 shows in sequence any message number Nmsg from 95 through 99 and the outlines of the patterns corresponding to the arrangement of the pattern numbers Nptn stored in the group number Ngrp specified by the message number Nmsg in the EEPROM 31. Since the pattern number Nmsg of the message pattern has been written, the display of the message number Nmsg is not reversed. Consequently, it is confirmed on the display 9 that the selected mode is related to the message pattern, but the mode is not for writing the pattern number Nmsg.
When the start switch 7 is pressed, the electronic controller 20 starts separate processes for stitching the selected pattern. The pattern number Nptn developed in the pattern number storage region of the RAM 25 is read in order from the smallest value of the combination pointer P. The set of the stitch data corresponding to the read pattern number Nptn is read from the ROM 23. By driving the sewing mechanism of the sewing machine, the message pattern selected with the numeral keys 13 is formed.
OPERATION D
The operation for correcting the input with the numeral keys 13 will now be explained. When the operator presses the cancel key 19, the electronic controller 20 executes the process of this operation.
When the operator presses the cancel key 19, the electronic controller 20 executes the subroutine for canceling the pattern number as shown in the flowchart of FIG. 5D. First, it is determined at step S370 whether the message number Nmsg corresponds to the value FF.
When it is determined at step S370 that the message number Nmsg corresponds to the value FF, the electronic controller 20 is in the condition as explained in OPERATION A. Specifically, the selected mode is not for writing or reading the message pattern. Therefore, at step S380 the memory unit M(P) at the address specified by the combination pointer P in the pattern number storage region of the RAM 25 is cleared away. Subsequently, step S390 executes the process for the decrement of the combination point P, and the process ends. Through these processes only the last stored pattern number Nptn is deleted from the RAM 25, and the process returns to the condition before the pattern number Nptn is stored.
On the other hand, if step S370 determines that the message number Nmsg does not correspond to the value FF, step S400 determines whether the message flag Fmsg is set to one or not.
When step S400 determines that the message flag Fmsg is set to one, the electronic controller 20 is in the condition, as explained in OPERATION B, for writing the message pattern.
Subsequently, at step S410 the memory unit M(P) at the address specified by the value of the combination pointer P in the pattern number storage region of the RAM 25 resets to the value FF. At step S420 the memory unit MEP(Ngrp,P) at the address specified by the group number Ngrp and the combination pointer P in the EEPROM 31 resets to the value FF. After step S430 decrements the combination pointer P, the process ends. Through this process, the last written pattern number Nptn is deleted from the RAM 25 and the EEPROM 31. The process thus returns to the condition before the pattern number Nptn is written into the RAM 25 and the EEPROM 31.
On the other hand, when step S400 determines that the message flag Fmsg is not set to one, for example, the process is in the condition that the message pattern is read with the numeral keys 13 as explained in OPERATION C. After the content of the read message pattern is confirmed, the pattern numbers developed in the RAM 25 are deleted so as to alter all the read message patterns.
Specifically, at step S440 the message number Nmsg is reset to the value FF and at step S450 the group number Ngrp is reset to the value FF. At step S460 each memory unit M in the pattern number storage region of the RAM 25 is reset to the value FF, and at step S470 the combination pointer P is reset to the value FF. Through this process, all the pattern numbers Nptn developed in the pattern number storage region in the RAM 25 are deleted. Even when the pattern numbers Nptn are deleted from the RAM 25, no arrangement of the pattern numbers Nptn is deleted from the EEPROM 31.
As aforementioned, when the sewing machine of this embodiment is operated, the reversal display of the message number Nmsg on the display 9 can be confirmed. When the pattern is selected with the numeral keys 13, the pattern number Nptn is stored in the EEPROM 31. The pattern number Nptn stored in the EEPROM 31 is copied into the RAM 25 to form the arrangement of the patterns. For example, a name can be stored for reuse as a message pattern in the EEPROM 31. By reading the name with the numeral keys 13, the stored name can be repeatedly stitched on the fabric. The selected pattern can thus easily be entered.
When the message number Nmsg is shown on the display 9, it is determined that the message pattern is entered. On the other hand, when the message for only one use is entered. On the other hand, when the message for only one use is entered, no message number Nmsg is shown on the display 9. When the display of the message number Nmsg is reversed, the mode is for writing the pattern number of the message pattern into the EEPROM 31. When the mode is for reading the pattern number of the message pattern from the EEPROM 31, the ordinary display of the message number Nmsg is shown in the display 9. Consequently, the confirmation of the mode with the display can avoid operational mistakes and facilitate the operation of the sewing machine.
From the above description of a preferred embodiment of the invention, those skilled in the art will perceive improvements, changes, and modifications. Such improvements, changes and modifications within the skill of the art are intended to be covered by the appended claims. For example, the nonvolatile storage apparatus comprises a RAM supported by a battery. In this embodiment every time the pattern is selected, the pattern number is stored. The arrangement of all the selected patterns stored in the RAM 25 can be stored in the nonvolatile storage apparatus. When power source is cut during the operation by mistake, the pattern numbers of all the selected patterns fail to be stored in the nonvolatile memory apparatus. However, since it is shown on the display that the selected mode is for writing the pattern number in this embodiment, such mistake can substantially be avoided and the entered pattern can be prevented from becoming invalid.
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In the sewing machine of this invention, the operator can confirm on the selected-mode display M9 provided in the display M4 that the selected mode is for writing the pattern and whether the selected pattern is for only one use or the selected pattern is to be stored in the nonvolatile storage M7. The pattern selector M2 selects at least two patterns from the pattern-data storage M1. The arrangement of the selected patterns is stored in the pattern storage M3. The stored arrangement of the patterns is stored in the nonvolatile storage M7. Through specified processes, the patterns reader M8 develops the arrangement of the pattern stored in the nonvolatile storage M7 into the pattern storage M3. The controller M6 sequentially reads the arrangement of the patterns developed in the pattern storage M3 and drives the sewing mechanism M5 to form the arrangement of the patterns on fabric. When the pattern to be used repeatedly is thus once entered, the pattern can repeatedly be stitched on fabric.
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BACKGROUND OF THE INVENTION
1. Field of the Invention
The present invention relates to an automatic analyzer for performing qualitative and quantitative analyses of living samples, such as blood and urine, and more particularly to an automatic analyzer having a larger number of reagents placed per unit area.
2. Description of the Related Art
In an automatic analyzer for performing qualitative and quantitative analyses of living samples, such as blood and urine, the analysis is generally performed through the steps of adding, to each of the living samples, a reagent that reacts with a particular component in the sample to change a sample color, and measuring a change of the sample color (i.e., a change of absorbance) by using a photometer or the like.
In such an automatic analyzer, reagents required for the measurement are placed in the analyzer before the sample analysis is started. Recently, with improvements of reagents, the number of analysis items measurable by the automatic analyzer has increased, and the number of kinds of reagents has increased correspondingly.
For that reason, there is a demand for increasing the number of reagents capable of being placed in the automatic analyzer. On the other hand, space saving of the automatic analyzer is also demanded. In the past, a reagent bottle having a volume in match with the quantity of the reagent, which is estimated to be consumed in a day, so that once the reagent is replaced with a new one in the morning of everyday, it is possible to avoid the reagent from being used up in the day and to eliminate the necessity of replacing the reagent bottle. However, when the volume of each reagent bottle is reduced to increase the number of reagents capable of being placed in the automatic analyzer, this increases a possibility that the reagent runs out in some reagent bottle during the analysis. Accordingly, there is a demand for the function capable of smoothly replacing the reagent bottle even during the analysis.
Patent Reference 1; JP,A 10-142230 discloses such a technique that sample dispensing or subsequent reagent sampling can be temporarily stopped by an operator depressing a “reagent registration interrupt” key on an analyzer control screen when the amount of the remaining reagent has become small during the analysis. Because the reagent can be replenished or replaced during the analysis, the reagent is just required to be placed in a necessary minimum amount. It is therefore possible to provide an analyzer in which the reagent can be replenished or replaced even when the reagent has run out, and to realize space saving of the analyzer.
SUMMARY OF THE INVENTION
Although the technique disclosed in Patent Reference 1 is able to stop the dispensing of the sample, the dispensing of the reagent cannot be stopped until the end of the analysis for a reaction cell in which the sample has already been dispensed. In the case of an analysis item based on a 2-liquid reaction using R 1 (first reagent: i.e., a reagent added immediately after the sample has been dispensed into the reaction cell) and R 2 (second reagent: i.e., a reagent dispensed after about 5 to 10 minutes from the dispensing of the first reagent), the operation of dispensing the reagent is actually stopped after R 2 has been completely dispensed to all reaction cells in which the samples have already been dispensed. Thus, a wasteful waiting time occurs. Further, samples cannot be dispensed during not only such a waiting time, but also a time required for replacing the reagent. This leads to a problem of taking a longer time until the sample analysis is resumed after replacing the reagent.
It is an object of the present invention to provide an automatic analyzer with the function of minimizing a reduction in an analysis speed even when the necessity of replacing a reagent occurs.
To achieve the above object, the present invention is constructed as follows.
The automatic analyzer of the present invention comprises a reaction cell for mixing a sample and at least one reagent therein; a sample dispensing unit for dispensing the sample into the reaction cell; a reaction cell carrying unit for holding the reaction cell in plural number and successively carrying the reaction cells at constant timing; a reagent dispensing unit for drawing a reagent from a reagent bottle and injecting the drawn reagent into the reaction cell on the reaction cell carrying unit at predetermined timing; and a control unit for, when the reagent bottle for supplying the reagent to the reagent dispensing unit is replaced, controlling the sample dispensing unit such that sample dispensing operation of the sample dispensing unit is stopped for a preset time required for the reagent replacement at a point in time prior to the reagent replacement by a period taken from the dispensing of the sample to timing of adding the reagent to the dispensed sample.
The reaction cell carrying unit is constituted, for example, as a mechanism of rotating a turntable on which a plurality of reaction cells are arranged along a circumference thereof, or as a mechanism of conveying a belt on which a plurality of reaction cells are arranged. Also, a path along which the reaction cells are transported is not limited to the form of a loop, but it may have the linear form. The expression “constant timing” means that the reaction cells are repeatedly moved and stopped at a predetermined cycle. While the reaction cells are in the stopped state, samples and reagents are dispensed into the reaction cells.
With the procedure of stopping the sample dispensing operation of the sample dispensing unit for the preset time required for the reagent replacement and then restarting the sample dispensing operation, an analysis suspension time can be minimized (i.e., restricted to only a time required for the reagent replacement), and hence a reduction in analysis processing efficiency can be suppressed in comparison with the technique disclosed in Patent Reference 1. At the time of the reagent replacement, the dispensing of the reagent by the reagent dispensing unit should be stopped to avoid interference with the operation of replacing the reagent bottle. Typical examples of the reagent dispensing unit are of the so-called dispenser type that a tube is connected to the reagent bottle and the reagent is sucked in a required amount, and of the so-called pipetter type that a dispensing (pipetting) probe is descended into the reaction cell to suck the reagent in a required amount. If such a reagent dispensing unit is actuated for the reagent replacement during the analysis operation, there may arise a possibility, for example, that the reagent is dispensed in an improper amount, or the dispensing probe hits and hurt the operator in the operation of replacing the reagent.
The expression “injecting the drawn reagent into the reaction cell on the reaction cell carrying unit at predetermined timing” means injection of a first reagent (Reagent 1 ; R 1 ) that is added immediately after dispensing the sample, and injection of a second reagent (R 2 ), a third reagent (R 3 ), a fourth reagent (R 4 ), etc. which are added thereafter. The timings of injecting the second and subsequent reagents (R 2 , etc.) are decided beforehand depending on the reagents to be, for example, 3 minutes, 5 minutes, etc. after the dispensing of R 1 . Further, only R 1 and R 3 are added in some of analysis items, while R 1 , R 2 and R 3 are all added in other analysis items.
The expression “at a point in time prior to the reagent replacement by a period taken from the dispensing of the sample to timing of adding the reagent to the dispensed sample” means that, in spite of the operator instructing the analyzer to stop for the reagent replacement at a current point in time, the reagent replacement cannot started at once and a message indicating a reagent replaceable state is displayed after the lapse of a time required from the dispensing of the sample at the current time to the timing of adding the relevant reagent, thereby informing the operator of the reagent replaceable state. Accordingly, even if the necessity of the reagent replacement is confirmed at the current point in time, the analyzer of the present invention is adaptable for that necessity only after the ongoing analysis operation is suspended.
In view of that point, it is preferable to estimate the timing of the reagent replacement for more prompt and precise adaptation. One preferable example of the method for estimating the timing of the reagent replacement is to provide a remaining-reagent amount monitoring unit and to previously decide, for example, a rule of “replacing the reagent in any case after 10 minutes from a point in time at which the amount of the remaining reagent has reached a certain level”. Another preferable example is to estimate, through predictive calculations based on information regarding the amount of the remaining reagent and the analysis items registered in the automatic analyzer to be analyzed from then, at what point in time the timing of the reagent replacement is reached from the current time.
According to the present invention, as described above, the analysis stop (suspension) time required for the reagent replacement can be minimized by temporarily stopping the dispensing of the sample and the dispensing of the reagent only for the preset time. It is therefore possible to provide an automatic analyzer in which a time loss with the reagent replacement is small even when the reagent is going to run out during the analysis, and a multi-item analysis can be performed while realizing space saving.
BRIEF DESCRIPTION OF THE DRAWINGS
FIG. 1 is a plan view of an automatic analyzer according to a first embodiment of the present invention;
FIG. 2 is a flowchart for replenishing reagents in a 2-reagent analysis according to the first embodiment;
FIG. 3 shows a procedure for dispensing a sample and reagents in the 2-reagent analysis according to the first embodiment;
FIG. 4 shows a control screen 1 used in the first embodiment;
FIG. 5 shows a control screen 2 used in the first embodiment;
FIG. 6 is a flowchart for replenishing reagents in a 3-reagent analysis according to the first embodiment;
FIG. 7 shows a procedure for dispensing a sample and reagents in the 3-reagent analysis according to the first embodiment; and
FIG. 8 is a plan view of an automatic analyzer according to a second embodiment of the present invention.
DESCRIPTION OF THE PREFERRED EMBODIMENTS
Embodiments of the present invention will be described below with reference to the drawings. FIG. 1 is a plan view of an automatic analyzer according to a first embodiment of the present invention. A plurality of reaction cells 35 are arranged along a circumference of a reaction disk 36 mounted on a casing 63 . A reagent disk 42 is disposed inside the reaction disk 36 , and a reagent disk 41 is disposed outside the reaction disk 36 . A plurality of reagent bottles 40 can be placed along a circumference of each of the reagent disks 41 , 42 . One reagent bottle 40 is able to contain two kinds of reagents. A transport mechanism 12 for moving a rack 11 , which holds a plurality of sample cups 10 thereon, is installed near the reaction disk 36 . Rails 25 , 26 are disposed to extend over the reagent disks 41 , 42 . Reagent probes 20 , 21 capable of moving in the direction parallel to the rail 25 and in the vertical direction are mounted to the rail 25 , and reagent probes 22 , 23 capable of moving in the 3-axis directions with respect to the rail 26 are mounted to the rail 26 . The reagent probes 20 , 21 , 22 and 23 are each connected to a reagent pump (not shown). Sample probes 15 , 16 capable of rotating and moving in the vertical direction are disposed between the reaction cells 35 and the transport mechanism 12 . The sample probes 15 , 16 are each connected to a sample pump (sample syringe, not shown). Stirrers 30 , 31 , a light source 50 , an optical detector 51 , and a cell cleaning mechanism 45 are arranged around the reaction disk 36 . The cell cleaning mechanism 45 is connected to a cleaning pump (cleaning syringe, not shown). Cleaning ports 54 are disposed in respective areas where the sample probes 15 , 16 , the reagent probes 20 , 21 , 22 and 23 , and the stirrers 30 , 31 are operable.
A reagent registering procedure using the automatic analyzer thus constructed will be described below.
A barcode is attached to each of the reagent bottles 40 . An operator places the reagent bottle 40 on the reagent disk 41 or 42 after opening a cover (not shown) of the reagent disk 41 or 42 . After the placement of reagents used for an analysis, when the analyzer recognizes that the operator has closed the cover (not shown) of the reagent disk 41 or 42 , the analyzer automatically executes the reagent registering procedure by recognizing the barcode attached to the reagent bottle 40 with a barcode reader 61 or 62 which is disposed respectively aside the reagent disk 41 or 42 . An analysis procedure using the analyzer of this embodiment will be described below.
The following description is made in accordance with a 2-reagent analysis method (i.e., an analysis method of dispensing two kinds of reagents into a sample with a time difference between them to develop a reaction).
A sample to be inspected, e.g., blood, is put in the sample cup 10 and is transported by the transport mechanism 12 while being set on the rack 11 . A certain amount of the sample sucked by the sample probe 15 is dispensed into one of the reaction cells 35 arranged on the reaction disk 36 , and a certain amount of a first reagent is dispensed into the reaction cell 35 from one of the reagent bottles 40 placed on the reaction disk 41 or 42 by using the reagent probe 21 or 22 . The mixture in the reaction cell 35 is then stirred by the stirrer 30 or 31 . After the lapse of a predetermined time, a certain amount of a second reagent is dispensed into the reaction cell 35 from another reagent bottle 40 placed on the reaction disk 41 or 42 by using the reagent probe 21 or 22 , followed by stirring again by the stirrer 30 or 31 . After the reaction for a predetermined time, the sample absorbance is measured by the optical detector 51 , and the measured result is outputted to a control computer 60 . If there remains one or more other measurement items requested, the above-described sampling process is repeated. For all the samples set on the rack 11 , the sampling process is similarly repeated until all the set measurement items are completed.
One example of a procedure for replenishing reagents during the analysis in the automatic analyzer of this embodiment will be described below with reference to FIGS. 2 to 5 .
In this example, an interrupt time for replenishing reagents is set before the start of the analysis (operation) (( 2 - 1 ) in FIG. 2 ). Note that the setting of the interrupt time is not always required to be registered before the start of the analysis, but the setting may be performed at any desired point in time before the timing of an interrupt for replenishing reagents.
Then, the analysis (operation) is started (( 2 - 2 ) in FIG. 2 ). When it is desired to replenish one or more reagents during the analysis, the operator depresses a “reagent registration interrupt” button on an analyzer control screen, thereby issuing an “interrupt” command (( 2 - 3 ) in FIG. 2 and FIG. 4 ). The button for issuing the “interrupt” command is not always required to locate on the control screen, but it may be disposed on the analyzer. In response to the button depression, the analyzer temporarily stops the dispensing of the sample for the preset “setting time” (sampling stop state) as indicated by ( 3 - 2 ) in FIG. 3 . Simultaneously, the analyzer displays a “time up to reagent replenishment enable state” ( FIG. 4 ), i.e., a time up to the timing at which the replenishment of the reagents will be enabled, as shown in FIG. 4 .
After the lapse of the “setting time”, the analyzer restarts the dispensing of the sample (( 2 - 6 ) in FIG. 2 and ( 3 - 3 ) in FIG. 3 ). Subsequently, at the timing in the dispensing of the second reagent corresponding to the timing at which the dispensing of the sample was temporarily stopped, the analyzer stops the dispensing of the sample again for a period corresponding to the “setting time” (( 2 - 7 ) in FIG. 2 and ( 3 - 4 ) in FIG. 3 ). Although only the dispensing of the sample is temporarily stopped at the timing of ( 3 - 2 ) in FIG. 3 , the dispensing of the reagent is also temporarily stopped at the timing of ( 3 - 4 ) in FIG. 3 . This state allows the replenishment of the reagent to the reagent disks 41 and/or 42 . In other words, during the subsequent “setting time”, the operator can replenish the supplemental reagents to the relevant reagent bottles on the reagent disks 41 and/or 42 in accordance with the above-described procedure (( 3 - 4 ) in FIG. 3 ).
Upon reaching the timing at which the replenishment of the reagents is enabled, the analyzer displays a time up to operation restart on the control screen, thus indicating a reagent replenishment allowable time to the operator (( 2 - 8 ) in FIG. 2 and FIG. 5 ). Then, after the lapse of the “setting time”, the analyzer restarts the analysis (operation) (( 2 - 9 ) in FIG. 2 and ( 3 - 5 ) in FIG. 3 ).
An analysis procedure in accordance with a 3-reagent analysis method (i.e., an analysis method of dispensing three kinds of reagents into a sample at a time difference to develop a reaction) will be described below.
A sample to be inspected, e.g., blood, is put in the sample cup 10 and is transported by the transport mechanism 12 while being set on the rack 11 . A certain amount of the sample sucked by the sample probe 15 is dispensed into one of the reaction cells 35 arranged on the reaction disk 36 , and a certain amount of a first reagent is dispensed into the reaction cell 35 from one of the reagent bottles 40 placed on the reaction disk 41 or 42 by using the reagent probe 21 or 22 . The mixture in the reaction cell 35 is then stirred by the stirrer 30 or 31 . After the lapse of a predetermined time, a certain amount of a second reagent is dispensed into the reaction cell 35 from another reagent bottle 40 placed on the reaction disk 41 or 42 by using the reagent probe 21 or 22 , followed by stirring again by the stirrer 30 or 31 . After the lapse of a predetermined time, a certain amount of a third reagent is dispensed into the reaction cell 35 from still another reagent bottle 40 placed on the reaction disk 41 or 42 by using the reagent probe 21 or 22 , followed by stirring again by the stirrer 30 or 31 .
After the reaction for a predetermined time, the sample absorbance is measured by the optical detector 51 , and the measured result is outputted to the control computer 60 . If there remains one or more other measurement items requested, the above-described sampling process is repeated. For all the samples set on the rack 11 , the sampling process is similarly repeated until all the set measurement items are completed.
One example of a procedure for replenishing reagents during the analysis in the automatic analyzer of this embodiment will be described below with reference to FIGS. 4 to 7 .
In this example, an interrupt time for replenishing reagents is set before the start of the analysis (operation) (( 4 - 1 ) in FIG. 6 ). Note that the setting of the interrupt time is not always required to be registered before the start of the analysis, but the setting may be performed at any desired point in time before the timing of an interrupt for replenishing reagents.
Then, the analysis (operation) is started (( 4 - 2 ) in FIG. 6 ). When it is desired to replenish one or more reagents during the analysis, the operator depresses the “reagent registration interrupt” button on the analyzer control screen, thereby issuing the “interrupt” command (( 4 - 3 ) in FIG. 6 and FIG. 4 ). The button for issuing the “interrupt” command is not always required to locate on the control screen, but it may be disposed on the analyzer. In response to the button depression, the analyzer temporarily stops the dispensing of the sample for the preset “setting time” (sampling stop state) as indicated by ( 4 - 5 ) in FIG. 6 . Simultaneously, the analyzer displays a time up to the timing at which the replenishment of the reagents will be enabled ( FIG. 4 ).
After the lapse of the “setting time”, the analyzer restarts the dispensing of the sample (( 4 - 6 ) in FIG. 6 and ( 5 - 3 ) in FIG. 7 ). Subsequently, at the timing in the dispensing of the second reagent corresponding to the timing at which the dispensing of the sample was temporarily stopped, the analyzer stops the dispensing of the sample again for a period corresponding to the “setting time” (( 4 - 7 ) in FIG. 6 and ( 5 - 4 ) in FIG. 7 ). Although only the dispensing of the sample is temporarily stopped at the timing of ( 5 - 2 ) in FIG. 7 , the dispensing of the second reagent is also temporarily stopped at the timing of ( 5 - 4 ) in FIG. 7 .
After the lapse of the “setting time”, the analyzer restarts the dispensing of the sample (( 4 - 8 ) in FIG. 6 and ( 5 - 5 ) in FIG. 7 ). Subsequently, at the timing in the dispensing of the third reagent corresponding to the timing at which the dispensing of the sample was temporarily stopped, the analyzer stops the dispensing of the sample again for a period corresponding to the “setting time” (( 4 - 9 ) in FIG. 6 and ( 5 - 6 ) in FIG. 7 ). Although only the dispensing of the sample and the dispensing of the second reagent are temporarily stopped at the timing of ( 5 - 4 ) in FIG. 7 , not only the dispensing of the sample, but also the dispensing of the first and third reagents are temporarily stopped at the timing of ( 5 - 6 ) in FIG. 7 . This state allows the replenishment of the reagent to the reagent disks 41 and/or 42 . In other words, during the subsequent “setting time”, the operator can replenish the supplemental reagents to the relevant reagent bottles on the reagent disks 41 and/or 42 in accordance with the above-described procedure (( 5 - 6 ) in FIG. 7 ).
Upon reaching the timing at which the replenishment of the reagents is enabled, the analyzer displays a time up to operation restart on the control screen, thus indicating a reagent replenishment allowable time to the operator (( 4 - 10 ) in FIG. 6 and FIG. 5 ). Then, after the lapse of the “setting time”, the analyzer restarts the analysis (operation) (( 4 - 11 ) in FIG. 6 and ( 5 - 7 ) in FIG. 7 ).
FIG. 8 is a-plan view of an automatic analyzer according to a second embodiment of the present invention.
The second embodiment differs from the first embodiment in including a reagent storage 171 for replenishment so that reagents can be automatically replenished during the analysis. The reagent storage 171 for replenishment is installed above a reagent disk 141 . A plurality of reagent bottles 140 can be placed on the reagent storage 171 for replenishment. A rail 172 is disposed to extend over the reagent storage 171 for replenishment, and a reagent holding mechanism 173 and a reagent uncapping mechanism 174 both capable of moving in the 3-axis directions with respect to the rail 172 are mounted to the rail 172 . A reagent bottle setting port 175 is provided at a front end of the reagent storage 171 for replenishment. A barcode reader 176 for reading a reagent barcode is disposed near the reagent bottle setting port 175 . A disposal port 177 allowing reagent bottle caps and the used reagent bottles 140 to be discarded therethrough is disposed near the reagent storage 171 for replenishment. A sample pump, a reagent pump, a cleaning pump (all of these pumps being not shown), an optical detector 151 , reaction cells 135 , a reagent disk 141 , reagent probes 120 , 121 , 122 and 123 , sample probes 115 , 116 , the reagent holding mechanism 173 , the reagent uncapping mechanism 174 , and the barcode reader 176 are connected to a control computer 160 .
A procedure for registering reagents in the second embodiment will be described below.
Respective reagents in the reagent bottles 140 placed on the reagent disks 141 , 142 are checked. Information of each reagent bottle 140 contains the position where the reagent bottle is placed in the reagent disk 141 or 142 , the lot, the expiry date, the amount of the remaining reagent, etc., and is stored in the control computer 160 . Based on the information stored in the control computer 160 , the operator checks the states of the reagent bottles 140 placed on the reagent disks 141 , 142 . The reagent bottle in which the reagent remains in small amount and will possibly run out during the analysis in that day is set in the reagent bottle setting port 175 . The barcode reader 176 reads the reagent information of the set reagent bottle, following which the set reagent bottle is transported to the reagent storage 171 for replenishment by the reagent holding mechanism 173 . The read reagent information and the position of the transported reagent bottle where it is placed in the reagent storage 171 for replenishment are outputted to the control computer(not shown). The reagent bottles for which the reagents are estimated to run out are all checked and transported in accordance with the above-described procedure. Further, a reagent bottle containing a reagent that is required for a special item and used at a very low frequency is also placed in the reagent storage 171 for replenishment in accordance with the above-described procedure.
One example of a procedure for replenishing reagents during the analysis in the automatic analyzer of this embodiment will be described below. The following example is described in connection with a 2-reagent analysis, but it is similarly applicable to a 3-reagent analysis as well.
The analyzer monitors the reagent amount in each reagent bottle during the analysis. When the analyzer detects that the reagent amount has reduced to an insufficient level, it temporarily stops the dispensing of the sample for the preset “setting time” (( 3 - 2 ) in FIG. 3 ), followed by restarting the analysis after the predetermined time. Namely, after the lapse of the “setting time”, the analyzer restarts the dispensing of the sample (( 3 - 3 ) in FIG. 3 ). Subsequently, at the timing in the dispensing of the second reagent corresponding to the timing at which the dispensing of the sample was temporarily stopped, the analyzer stops the dispensing of the sample again for a period corresponding to the “setting time” (( 3 - 4 ) in FIG. 3 ). Although only the dispensing of the sample is temporarily stopped at the timing of ( 3 - 2 ) in FIG. 3 , the dispensing of the reagent is also temporarily stopped at the timing of ( 3 - 4 ) in FIG. 3 . This state allows the replenishment of the reagent to the reagent disks 141 and/or 142 . In other words, during the subsequent “setting time”, the analyzer automatically transports one or more reagent bottles 140 to the reagent disks 141 and/or 142 from the reagent storage 171 for replenishment, whereby the analysis can be avoided from stopping.
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An automatic analyzer capable of replenishing a reagent even during an analysis and minimizing a suspension of the analysis. The automatic analyzer includes a plurality of reaction cells and a unit for holding reagents used in analyses. A plurality of reagents are dispensed to a sample in each reaction cell with a time difference to develop a reaction, and a liquid after the reaction is measured. After temporarily stopping the operation of dispensing the sample for a preset time during the analysis, the sample dispensing operation is restarted. Then, the sample dispensing operation is temporarily stopped again for the preset time at the timing in the dispensing of the reagent corresponding to the timing at which the sample dispensing operation was temporarily stopped. In the automatic analyzer, therefore, an analysis suspension due to registration and replacement of reagents during the analysis can be minimized, a larger number of reagents can be loaded, and a throughput per unit time can be increased.
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BACKGROUND OF THE INVENTION
1. Field of the Invention
This invention relates to power conditioners for electrical distribution systems, particularly to active power conditioners, and especially to active power conditioners for mitigating zero-sequence currents in electrical distribution systems.
2. Description of the Prior Art
In a balanced three-phase, four-conductor electric power system, the algebraic sum of the source phase voltages, or source line-to-neutral voltages, is zero volts. Hence, in a WYE-connected system with balanced phase voltages and a balanced linear load, the neutral current, I n , is zero amperes, and the currents in the three phases are all equal in magnitude but differ by 120° in Itime phase. A multi-phase load in which the impedance in one or more phases differs from those of other phases is said to be unbalanced. Many types of loads on current electric power.systems can be non-linear and unbalanced. Such loads can generate certain harmonics of currents and voltages in the phases of a three-phase system. Unbalanced loading can result in a fundamental (60 Hz) neutral current. Also, one consequence of non-linear loading of electric power systems is an increase of harmonic current in the neutral path.
In general, a current which appears in the neutral path at fundamental and harmonic frequencies as a result of non-linear loading or unbalanced loading may be termed a zero-sequence current. Zero-sequence currents in each of the phases can cause zero-sequence currents to appear in the neutral path. In power systems that supply a substantial non-linear load, neutral currents may exceed the rated ampacity of the neutral path, resulting in elevated temperatures and increased thermal losses in the neutral conductors and terminations. In extreme cases, excessive heating losses may damage the insulation of the neutral conductor and other conductors in the same conduit, causing the neutral conductor to fail as an open circuit, or damage materials in contact with the neutral.
A number of approaches have been applied to prevent or eliminate instances of neutral thermal overload. These include: (1) installing components with increased ampacity in the neutral path; (2) applying transformer arrangements to shunt zero-sequence currents out of the neutral path; and (3) using passive and active filters to shunt harmonic currents out of the neutral path.
Installing components with increased ampacity in the neutral path typically requires retrofitting existing electrical systems with either an upgraded neutral ampacity or a parallel neutral path. In either case, the necessary modifications could be prohibitively expensive.
Zero-sequence current shunt transformers typically act as current dividers, with the reduction of zero-sequence current being dependent on the ratio of the transformer zero-sequence impedance to the power system zero-sequence impedance. Such arrangements may filter out only about one-half of the zero-sequence neutral current, or less, which reduction may be insignificant relative to the system burden, and cost and complexity of the shunt transformer hardware.
Finally, passive and active filters can be difficult to implement and reliably operate, with difficult-to-predict behavior in practice. Such unpredictability can arise from transient ringing or resonant behavior at particular frequencies. With such filters, there are trade-offs between the filter's transient response and filter effectiveness. In addition, filters of this type typically have resistive components which consume real power.
There is a need, therefore, for a stable, active neutral current compensator which can nullify zero-sequence currents in the existing neutral line of a multi-phase power distribution system without consuming substantial amounts of real power to shunt fundamental and harmonic zero-sequence currents to ground.
SUMMARY OF THE INVENTION
The invention provides for an active neutral current compensator (ANCC) for controlling a zero-sequence current in a conductor of a multi-phase power distribution system. The ANCC consists of magnetic coupling means, which may be a multi-phase neutral-forming magnetic structure, for coupling the multi-phase power distribution system to the active neutral current compensator, a current sensing means, connected with the aforementioned conductor, for producing a control signal representative of the zero-sequence current in the conductor, and compensating means such as, for example, a feedback control system, which generates a nullificatory current flow, thereby forcing the zero-sequence current to be generally zero, in response to the current sensing means control signal.
In a first present preferred embodiment, the multi-phase, neutral-forming magnetic structure of the ANCC can be a three-phase neutral-forming autotransformer which is connected with the compensating means. The compensating means may consist of current sensing means for detecting a zero-sequence current and it is also preferred that the feedback control or compensating means include a cancelling means, which may be a controllable voltage source, preferably a single-phase linear or switching amplifier. In combination, the three-phase neutral-forming autotransformer connected with the single-phase inverter can compensate zero-sequence phase and neutral currents in multi-phase power distribution systems.
In other embodiments, it is preferred that the ANCC employs a multi-phase transformer as the multi-phase neutral-forming magnetic structure and utilizes a multi-phase transformer and compensator arrangement to compensate zero-sequence phase and neutral currents in multi-phase systems. It is preferred that the compensator have cancelling means, preferably a controllable voltage source and particularly a single-phase linear or switching amplifier, and that the compensator be regulated by a zero-sequence current controller which can continuously vary its output according to a sensed zero-sequence current on the source neutral line. The ANCC is connected with the zero-sequence current path of the electrical distribution system so that zero-sequence currents may be shunted to ground while the passage of positive- and negative-sequence currents to ground are blocked.
In a second present preferred embodiment, a grounded-wye/unloaded-delta transformer configuration is provided as the multi-phase, neutral-forming magnetic structure. In a third present preferred embodiment, a zig-zag auto-transformer can be provided as the multi-phase, neutral-forming magnetic structure. In each of these embodiments, it is also preferred to provide as the compensation means controllable voltage source, in particular, a single-phase linear or switchable amplifier, and more particularly, a single-phase inverter, and a zero-sequence current controller for regulation of transformer reactance. The inverter voltage is maintained so that the transformer reactance is approximately cancelled, thus allowing the net ANCC zero-sequence equivalent impedance to ground to be minimized, preferably to zero.
In one presently preferred method, zero-sequence phase and neutral currents, which may arise from the connection of non-linear loads to the power source, are sensed on a conductor of a multi-phase electrical distribution system by a zero-sequence current controller. The controller produces a control signal proportional to the sensed zero-sequence current. The controller can continuously adjust a voltage on an inverter which is connected with the zero-sequence current path of the distribution system so that a transformer reactance can be approximately cancelled, thus permitting zero-sequence currents to be shunted by a low impedance path to ground. Sensing of zero-sequence current may use the neutral line or at least one of the phase lines.
Other details, objects and advantages of the invention will become apparent as the following description of certain present preferred embodiments and certain present preferred methods proceeds.
BRIEF DESCRIPTION OF THE DRAWINGS
FIG. 1 is a diagram of an equivalent circuit of a three-phase, four-wire distribution system, using an ANCC according to the present invention, with line-to-neutral-connected non-linear loads.
FIG. 2 is a diagram of an ANCC derived from a three-phase neutral-forming autotransformer.
FIG. 3 is a diagram of an ANCC derived from a grounded-wye/unloaded-DELTA three-phase transformer.
FIG. 4 is a diagram of an equivalent circuit of a three-phase, four-wire distribution system, using a grounded-wye/unloaded-delta transformer-basedANCC according to the present invention, with line-to-neutral-connected non-linear loads.
FIG. 5 is a diagram of an ANCC derived from a zig-zag auto-transformer.
FIG. 6 is a diagram of an equivalent circuit of a three-phase, four-wire distribution system, using a zig-zag auto-transformer-based ANCC according to the present invention, with line-to-neutral-connected non-linear loads.
FIG. 7 is a diagram of a positive-sequence equivalent network employing an ANCC according to present invention in response to 60 Hz sinusoids.
FIG. 8 is a diagram of a positive-sequence equivalent network employing an ANCC according to the present invention in response to harmonic sinusoids.
FIG. 9 is a diagram of a negative-sequence equivalent network employing an ANCC according to the present invention in response to 60 Hz sinusoids.
FIG. 10 is a diagram of a zero-sequence equivalent network employing an ANCC according to the present invention.
FIG. 11a is an illustration of three-phase nonlinear load current, and resultant neutral line current.
FIG. 11b is an illustration of phase and neutral current components which are supplied by the ANCC.
FIG. 11c is an illustration of three-phase source currents, and resultant neutral current which arises from ANCC operation.
DESCRIPTION OF THE PREFERRED EMBODIMENTS
The embodiments of the ANCC described herein are active power conditioners suited for mitigating undesired zero-sequence phase and neutral currents. In general, the ANCC consists of a magnetic coupling means, which may be a multi-phase neutral-forming magnetic structure, for coupling the multi-phase power distribution system to the active neutral current compensator, a current sensing means, connected with the aforementioned conductor, for producing a control signal representative of the zero-sequence current in a conductor of a multi-phase power distribution system, and a compensating means such as, for example, a feedback control system, which forces the zero-sequence current to be generally zero, in response to the current sensing means control signal.
In one embodiment, it is preferred that the multi-phase neutral-forming structure of the ANCC be a three-phase neutral-forming autotransformer which is connected with the compensating means. The compensating means receives an input signal from a current sensing means, which signal is representative of the zero-sequence currents. In such embodiments, it is also preferred that the feedback control or compensating means include a controllable voltage source, such as, for example, a single-phase inverter. In combination, the three-phase neutral-forming autotransformer connected with the single-phase controllable voltage source can compensate zero-sequence phase and neutral currents in multi-phase systems.
In other embodiments, it is preferred that the ANCC employs a multi-phase transformer as the multi-phase neutral-forming structure and utilizes a multi-phase transformer and feedback controller arrangement to compensate at least one of zero-sequence phase and zero-sequence neutral currents in multi-phase systems. It is preferred that the feedback controller have a controllable voltage source, particularly a single-phase linear or switching amplifier, more particularly a single-phase inverter, and be regulated by a zero-sequence current controller which can vary inverter output according to a sensed current on the conductor. The inverter output to the transformer can vary an apparent transformer reactance such that the net ANCC equivalent impedance is approximately zero. The ANCC employs a transformer configuration which acts as high impedance to positive- and negative- sequence excitation, but provides a low impedance shunt path to zero-sequence excitation. Although it is preferred to sense zero-sequence current on the neutral line, zero-sequence phase current, as sensed on at least one of the power distribution phase lines may be used as an input to the zero-sequence current controller.
The ANCC is an active power conditioner which utilizes a controllable voltage-source to implement a three-phase zero-sequence current filter. This compensator is capable of (1) eliminating neutral currents caused by load imbalance or non-linearity; (2) improving power factor by reducing phase current distortion; and (3) restoring partial balance to unbalanced loads. In the ideal case, the ANCC performs these functions without consuming real power. The ANCC can effect full or partial elimination of any or all zero sequence currents drawn from the source as desired by the user. This may include (1) eliminating unbalance currents at fundamental frequency while passing all zero sequence harmonics; (2) eliminating triplen harmonics (i.e., harmonics arising at multiples of the frequency such as 3, 9, 15, etc.) while permitting fundamental unbalance; or (3) eliminating substantially all zero-sequence source currents. The ANCC can also facilitate the arbitrary injection of zero-sequence currents at any frequency, as desired. Further, the ANCC can limit zero-sequence current, for example, by holding current RMS values below a preselected value.
In FIG. 1, an equivalent multi-phase circuit is illustrated for three-phase, four-wire power distribution system 1. Power supply network 2, as represented by Thevenin-equivalent phase power sources 3a, 3b, 3c, feeds non-linear loads 4a, 4b, 4c. With each source 3a, 3b, 3c, may be associated source impedance 5a, 5b, and 5c. The phase-to-neutral voltage for sources 3a, 3b, and 3c may be symbolically represented by voltages Ean,s, Ebn,s, and Ecn,s, respectively. For balanced loads, impedances 5a, 5b, 5c, tend to be equal, and thus, phase source currents 6a (I a ,s), 6b (I b ,s), and 6c (I c ,s) can differ in phase by 120°, but have equal magnitudes.
However, with unbalanced loading, the instantaneous sum of phase currents 6a, 6b, 6c in system 1 is non-zero, and zero-sequence neutral current (I n ,s) 7 flows in neutral conductor 8. This can be seen by the relationship: ##EQU1## Therefore, as non-linear loads are joined to system 1, zero-sequence neutral current 7 can begin to flow between loads 4a, 4b 4c, and power supply 2. Each of the phase currents 6a, 6b, 6c contribute a zero-sequence phase current to zero-sequence neutral current 7 according to the relationship: ##EQU2## To reduce the effect of zero-sequence current 7 in the neutral conductor, ANCC 9 can be connected between distribution conductors 10a, 10b, and 10c, and neutral conductor 8 by ANCC phase conductors 11a, 11b, 11c, and ANCC neutral conductor 12, respectively. Thus, ANCC 9 can eliminate both phase and neutral zero-sequence currents.
In a first presently preferred embodiment according to the present invention, as shown in FIG. 2, it is preferred to employ a three-phase neutral-forming auto-transformer 35 as the multi-phase neutral-forming magnetic structure. In this embodiment, it is preferred to connect ANCC 39 to three-phase distribution conductors 36a, 36b, 36c, by ANCC phase conductors 37a, 37b, 37c. It also is preferred to connect a controllable voltage source such as, for example, single-phase inverter 32 in series with the zero sequence current flow path of three-phase neutral-forming autotransformer 35 so that inverter 32 receives the summed zero-sequence phase currents from conductors 36a, 36b, 36c. The voltage of inverter 32 is then varied to cancel the zero-sequence current in neutral conductor 34. In response to the sensed zero-sequence current as detected by current sensing means 30, sensing means 38 drives a signal in controller 33 which provides control over inverter 32.
Fundamental and harmonic zero-sequence currents drawn by loads on distribution conductors 36a, 36b, 36c, which are electrically "downstream" from ANCC 39, may be shunted through the artificially-induced short-circuit and thus may be prevented from propagating further "upstream" toward the power supplies. Because ANCC 39 acts as a high impedance to positive- and negative-sequence excitation, it may not substantially affect positive- and negative-sequence fundamental and harmonic load currents.
In a second presently preferred embodiment according to the present invention, as shown in FIG. 3, it is preferred to employ a grounded-wye/unloaded-delta transformer 135 as the multi-phase, neutral-forming magnetic structure. In this embodiment, ANCC 139 is connected to three-phase distribution conductors 136a, 136b, 136c, by ANCC phase conductors 137a, 137b, 137c. It is preferred to control the operation of transformer 135 with a control means, which control means may consist of a controllable voltage source such as, for example, inverter 132 and zero-sequence current controller 133. It also is preferred to connect single-phase inverter 132 in series with the zero-sequence current flow path on the unloaded-delta side of transformer 135. The voltage of inverter 132 is then varied to cancel the equivalent impedance of transformer windings 140a, 140b, 140c, ideally creating a zero impedance shunt path for zero-sequence currents. The value of the equivalent impedance of transformer windings 140a, 140b, 140c, needed to create the zero impedance shunt path, can be determined by controller 133 which determines the magnitude of the current flowing through neutral conductor 134, using neutral current sensing means 138.
Although it is preferred that at least one current sensing means 138 be connected to neutral conductor 134, other preferred embodiments can provide for at least one current sensing means 138 on selected ones of distribution conductors 137a, 137b, and 137c to sense the zero-sequence phase current. Also, it is presently preferred to sense the zero-sequence current flowing between ANCC 139 and the power supply. However, current sensing means 138, which can include an open-loop control system, may also be used to sense zero-sequence current between ANCC 139 and the load.
Fundamental and harmonic zero-sequence currents drawn by loads on distribution conductors 136a, 136b, 136c, which are electrically "downstream" from ANCC 139, are shunted through the artificially-induced short-circuit and thus prevented from propagating further "upstream" toward the power supplies. Because ANCC 139 acts as a high impedance to positive- and negative-sequence excitation, it may not substantially affect positive- and negative-sequence fundamental and harmonic load currents.
The grounded wye/unloaded delta-based ANCC 139 of FIG. 3 is implemented in the three-phase, four-wire equivalent distribution system 201 shown in FIG. 4. Similar to distribution system 1 shown in FIG. 1, power supply network 202, as represented by Thevenin-equivalent phase power sources 203a, 203b, 203c, feeds non-linear loads 204a, 204b, 204c. With each source 203a, 203b, 203c, may be associated source impedance 205a, 205b, and 205c.
Also as in FIG. 1, phase-to-neutral voltages for sources 203a, 203b, and 203c may be symbolically represented in FIG. 4 by voltages Ean,s, Ebn,s, and Ecn,s, respectively. To reduce the effect of zero-sequence current 207 in the neutral conductor, grounded wye/unloaded delta ANCC 209 can be connected between line distribution conductors 210a, 210b, and 210c, and neutral conductor 208, by ANCC phase conductors 211a, 211b, 211c, and ANCC neutral conductors 212a, 212b, 212c, respectively. Equivalent compensation source 214 provides the voltage necessary to compensate transformer equivalent impedance 213 so that zerosequence currents may be shunted and diverted from neutral conductor 208.
In a second presently preferred embodiment according to the present invention, as shown in FIG. 5, it is preferred to employ a zig-zag auto-transformer 235. In this embodiment, ANCC 239 is connected to three-phase distribution conductors 236a, 236b, 236c, by ANCC phase conductors 237a, 237b, 237c. Similar to FIG. 3, it is preferred to control the operation of transformer 235 with a control means, which control means may consist of inverter 232 and zero-sequence current controller 233. It also is preferred to connect controllable voltage source, such as, for example, single-phase inverter 232 in series with the zero-sequence current flow path on neutral-to-neutral connection 241 between neutral conductor 234 and auto-transformer 235. The voltage of inverter 232 then may be varied to cancel the equivalent impedance of transformer windings 240a, 240b, 240c, ideally creating a zero impedance shunt path for zero-sequence circuits. The value of the equivalent impedance of secondary transformer windings 240a, 240b, 240c needed to create the zero impedance shunt path can be determined by control means 233, which determines the magnitude of the current flowing through neutral conductor 234 using neutral current sensing means 238. Fundamental and harmonic zero-sequence currents drawn by loads on distribution conductors 236a, 236b, 236c, which are electrically "downstream" from ANCC 239, are shunted through the artificially-induced short circuit and thus prevented from propagating further "upstream" toward the power supplies. Because ANCC 239 acts as a high impedance to positive- and negative-sequence excitation, it may not substantially affect positive- and negative-sequence fundamental and harmonic load currents.
The zig-zag auto-transformer-based ANCC 239 of FIG. 5 is implemented in the three-phase, four-wire equivalent distribution system 301 shown in FIG. 6. Similar to distribution system 1 shown in FIG. 1 and to system 202 in FIG. 4, power supply network 302, as represented by Thevenin-equivalent phase power sources 303a, 303b, 303c, feeds non-linear loads 304a, 304b, 304c. With each source 303a, 303b, 303c, may be associated source impedance 305a, 305b, and 305c. Also as in FIGS. 1 and 4, phase-to-neutral voltages for sources 303a, 303b, and 303c may be symbolically represented by voltages Ean,s, Ebn,s, and Ecn,s, respectively. To reduce the effect of zero-sequence current 307 in neutral conductor 308, zig-zag auto-transformer-based ANCC 309 can be connected between line distribution conductors 310a, 310b, and 310c, and neutral conductor 308, by ANCC phase conductors 311a, 311b, 311c, and ANCC neutral conductor 312, respectively. Equivalent compensation source 314 provides the voltage necessary to compensate transformer equivalent impedance 313 so that zero-sequence currents may be shunted and diverted from neutral conductor 308.
FIG. 7 is a positive-sequence equivalent network modeled after equivalent networks such as those shown in FIGS. 1, 4 and 6. For simplicity, the power supply network voltage 401 is chosen to be positive-sequence, 60 Hz sinusoids; also, the non-linear loads are modeled as current sink 404. Because of the sequence properties of ANCC 409, its equivalent positive-sequence impedance is
Z ANCC ,+ →∞
The shunt path of ANCC 409 acts as an open circuit to positive-sequence excitation. Therefore, it has no substantial effect on fundamental or harmonic positive-sequence currents drawn by the non-linear loads.
FIG. 8 also is a positive-sequence equivalent network based on the symmetrical component equivalent network shown in FIG. 7 but, unlike FIG. 7, illustrates the response of ANCC 409 to harmonic (f≠60 Hz) positive-sequence currents drawn by the linear loads. Because ANCC 409 behaves in a linear fashion, the ANCC negative-sequence impedance, as modeled in FIG. 9, is equal to its positive-sequence impedance:
Z ANCC ,- →∞
The shunt path of ANCC 409 acts as an open circuit to negative-sequence excitation. Consequently, it has no significant influence negative-sequence fundamental or harmonic currents drawn by the non-linear loads.
FIG. 10 illustrates a zero-sequence equivalent network for ANCC 409 by a variable voltage source 414 in series with the equivalent leakage reactance 413 of the transformer connection. By solving Kirchoff's voltage equation for the left-hand loop of the circuit in FIG. 9, the following relation for the zero-sequence source current can be determined: ##EQU3##
The inverter voltage can be continuously controlled so that the following relationship is always maintained:
EQUATION 4
E comp ,0 =-j X t ,0 I l ,0
If equation 3 is substituted into equation 4, and solved for the zero-sequence source and compensator currents, the following results are obtained:
EQUATION 5
I s ,0 =0
EQUATION 6
I comp ,0 =I l ,0
Using equations 4 and 6, the equivalent zero-sequence impedance of the ANCC may be calculated: ##EQU4##
When the inverter voltage is maintained as given in equation 4, the apparent transformer reactance is cancelled so that the net ANCC zero-sequence equivalent impedance is zero. The real power consumed by an ideal ANCC may also be calculated from equations 4 and 6: ##EQU5##
In the ideal case, therefore, the ANCC consumes no real power. Therefore, the compensating action of the ANCC may be purely reactive in nature. In a distribution system that is supplying three-phase power to a four-wire, nonlinear load connected in parallel with an ANCC, the ANCC provides an artificially-induced low-impedance path which shunts zero-sequence currents demanded by loads "downstream" from the ANCC. The zero-sequence currents circulate between the load and the ANCC, and thus are prevented from propagating further "upstream".
FIG. 11a illustrates two cycles of phase and neutral currents drawn by a four-wire load consisting of a three-phase set of line-to-neutral-connected non-linear impedances. Note that the phase currents add constructively in the neutral conductor. FIG. 11b depicts the zero-sequence components of the phase and neutral load currents, which are shunted through the ANCC. FIG. 11c represents the current drawn from the source by the parallel combination of the ANCC and the non-linear load. Two results of ANCC compensation are apparent from FIGS. 11a, 11b and 11c. First, the load neutral current is complemented, and thus cancelled, by the ANCC so that no neutral current is returned to the source. Second, the ANCC improves the aggregate distortion power factor of the load by reducing the total harmonic distortion of the phase currents. Table 1 provides a quantitative summary of ANCC performance. In addition to the foregoing, the ANCC tends to partially balance unbalanced loads by eliminating zero-sequence phase currents.
In one presently preferred method, zero-sequence phase and zero-sequence neutral currents, which may arise from the connection of non-linear loads to the power source, are sensed on at least one conductor of a multi-phase electrical distribution system. The apparent impedance in a zero-sequence current path of such multiple phase electrical distribution system is controlled responsive to the zero-sequence current sensed in the conductor so that at least one of zero-sequence phase and zero-sequence neutral currents are shunted to groun.d. The method may further include controlling an controllable voltage source, such as, for example, to produce a voltage proportional to and representative of a preselected equivalent zero-sequence impedance, and adjusting the voltage so that a transformer reactance proportional to at least one of zero-sequence phase and zero-sequence neutral currents is approximately cancelled, thus permitting zero-sequence currents to be shunted by a low impedance path to ground. Although sensing zero-sequence neutral current on the neutral line or conductor is presently preferred, sensing a zero-sequence phase current in at least one phase line of such multiple phase electrical distribution system may also be used to practice the method herein.
While specific embodiments of the invention have been illustrated, and methods of practicing the invention have been described, it will be appreciated by those skilled in the art that various modifications and alternatives to those details could be developed in light of the overall teachings of the disclosure. Accordingly, it is understood that the invention is not limited thereto but may be otherwise variously embodied and practiced within the scope of the following claims.
TABLE 1______________________________________Quantitative Summary of ANCC Performance______________________________________Load without com- Power Factor = 0.77 I.sub.neutral = 1.73 I.sub.phasepensationFIG. 11 (a)Load compensated Power Factor = 0.95 I.sub.neutral = 0by ANCCFIG. 11 (c)______________________________________
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An active power conditioner for mitigating zero-sequence currents in electrical distribution by items wherein a multi-phase, neutral-forming structure employs a controllable voltage source, which source is controlled by a current-responsive voltage controller, to cancel an equivalent impedance of the multi-phase, neutral-forming structure so that zero-sequence currents are shunted to ground, thereby effectively nullifying the zero-sequence current respective to the source. The multi-phase neutral-forming structure may include multi-phase, neutral-forming autotransformers, zig-zag autotransformers, grounded-wye/unloaded-delta transformers and the like. While zero-sequence fundamental harmonic currents may be selectively shunted to ground, positive- and negative-sequence currents may remain essentially unaffected. The compensating action employed herein may be purely reactive in nature and thus consume little real power.
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FIELD OF THE INVENTION
The invention relates to hydrocracking, and more particularly to multistage hydrocracking.
BACKGROUND ON THE INVENTION
In the refining of crude oil, vacuum gas oil hydrotreaters and hydrocrackers are employed to remove impurities such as sulfur, nitrogen and metals from the feed. Typically, the middle distillate boiling material (boiling in the range from 250° F.-735° F.) from VGO hydrotreating or moderate severity hydrocrackers does not meet the smoke point, the cetane number or the aromatic specification required.
Removal of these impurities in subsequent hydroprocessing stages (often known as upgrading), creates more valuable middle distillate products. Hydroprocessing technology (which encompasses hydrotreating, hydrocracking and hydrodewaxing processes) aims to increase the value of the crude oil by fundamentally rearranging molecules. The end products are also made more environmentally friendly.
In most cases, this middle distillate is separately upgraded by a middle distillate hydrotreater or, alternatively, the middle distillate is blended into the general fuel oil pool or used as home heating oil. Recently hydroprocessing schemes have been developed which permit the middle distillate to be hydrotreated in the same high pressure loop as the vacuum gas oil hydrotreating reactor or the moderate severity hydrocracking reactor. The investment cost saving and/or utilities saving are significant since a separate middle distillate hydrotreater is not required.
There are U.S. patents which are directed to multistage hydroprocessing within a single high pressure hydrogen loop. In U.S. Pat. No. 6,797,154, high conversion of heavy gas oils and the production of high quality middle distillate products are possible in a single high-pressure loop with reaction stages operating at different pressure and conversion levels. The flexibility offered is great and allows the refiner to avoid decrease in product quality while at the same time minimizing capital cost. Feeds with varying boiling ranges are introduced at different sections of the process, thereby minimizing the consumption of hydrogen and reducing capital investment.
U.S. Pat. No. 6,787,025 also discloses multi-stage hydroprocessing for the production of middle distillates. A major benefit of this invention is the potential for simultaneously upgrading difficult cracked stocks such as Light Cycle Oil, Light Coker Gas Oil and Visbroken Gas Oil or Straight-Run Atmospheric Gas Oils utilizing the high-pressure environment required for mild hydrocracking.
U.S. Pat. No. 5,980,729 discloses multistage hydrocracking, with a hot hydrogen stripper located between the hydrotreating and hydrocracking zones.
U.S. Pat. No. 6,241,876 teaches the use of countercurrent flow in hydrocrackers to maximize diesel production.
SUMMARY OF THE INVENTION
This invention, as are those discussed above, is directed to processes for upgrading the fraction boiling in the middle distillate range which is obtained from VGO hydrotreaters and moderate severity hydrocrackers. It is also directed to cracking VGO (vacuum gas oil) to near extinction. This invention preferably involves a multiple stage process employing a single hydrogen loop. It could, however, be used in any fixed bed hydroprocessing scheme such as mild hydrocracking, conventional single stage or multi-stage hydrocracking and hydrotreating applications.
The instant invention provides numerous economic advantages. In the preferred embodiment of this invention, co-current downflow and counter-current flow are occurring simultaneously in the second or subsequent hydroprocessing stage. Material may be removed from the second stage without passing through all of the beds, in order to prevent overcracking.
Furthermore, the reaction zones are optimized for specific feeds, resulting in lower hydrogen consumption and lower catalyst volume employed. This invention provides much higher conversion than that obtained in normal once-through hydrocrackers.
As depicted in the FIGURE, a recycle pump is employed in this invention to move the bottoms material to the second stage.
The invention is summarized as follows (further details are found in the Description of the Preferred Embodiment):
An integrated hydroprocessing method having at least two stages, each stage having at least one reaction zone and the second stage having an intermediate effluent and a bottoms effluent, said method comprising the following steps:
(a) combining an oil feed with a hydrogen-rich gas stream to form a feedstock; (b) passing the feedstock to a reaction zone of the first stage, which is maintained at conditions sufficient to effect a boiling range conversion and contacting it with hydroprocessing catalyst; (c) passing the effluent of step (b) to a hot high pressure separator, where it is combined with the bottoms effluent of the second stage and separated into an overhead fraction and bottoms fraction; (d) mixing the overhead fraction of step (c) with the intermediate effluent from the second stage to form a combined stream which is passed to a cold high pressure separator; (e) separating the combined stream of step (d) into a gaseous component, a hydrocarbon liquid stream and a sour water stream; (f) passing the gaseous component of step (e), which comprises hydrogen, to a recycle gas compressor; (g) combining the hydrocarbon liquid stream of step (e) with an overhead stream from a hot low pressure separator; (h) passing the stream of step (g) to a cold low pressure separator, where it is separated into an overhead stream which is subsequently fractionated into hydrogen and other product streams, and a bottoms stream, which is combined with a bottoms effluent of the hot low pressure separator from step (g); (i) passing the bottoms fraction of step (c) to the hot low pressure separator of step (g), where it is separated into the overhead stream of step (g) and into the bottoms effluent of step (h); (j) passing the combined stream of step (h) to a product stripper, in which the stream is contacted counter-currently with steam to produce an overhead stream and a bottoms stream; (k) passing the bottoms stream of steps) to fractionation, thereby producing product streams and a bottoms stream; (l) recycling the bottoms of step (k) to a reaction zone of the second stage, which is maintained at conditions sufficient to effect a boiling range conversion, and contacting it with hydroprocessing catalyst.
BRIEF DESCRIPTION OF THE FIGURE
The FIGURE illustrates an integrated multistage hydroprocessing scheme. The second stage illustrates both co-current and counter-current zones of hydrogen flow, with a flash zone in between for the removal of an intermediate effluent.
DETAILED DESCRIPTION OF THE INVENTION
Please refer to the FIGURE. Feed in stream 1 is mixed with preheated recycle gas (exchanger BB) in stream 2 . Stream 2 is a mixture of recycle gas from the recycle gas compressor (stream 16 ) and compressed high-purity make up gas from the make-up hydrogen compressor B (stream 21 ). Stream 3 is preheated in heat exchangers AA and first stage reactor feed furnace C and sent to the first reaction stage D. The first bed of first reaction stage D may contain hydrotreating catalyst suitable for treating VGO. The bed may alternately contain a mix of hydrotreating, demetallation and hydrocracking catalysts. There may be a succession of fixed beds E, with interstage quench streams, 4 , 5 , 6 , 7 delivering cold hydrogen in between the beds.
The effluent 8 of the first reaction stage D, which has been hydrotreated and partially hydrocracked, contains hydrogen sulfide, ammonia, light gases, naphtha, middle distillate and hydrotreated heavy gas oil. The effluent enters the hot high-pressure separator F (which operates as a flash drum), after being cooled in exchanger Z. Vapor stream from F, stream 9 , containing the light gases, naphtha and middle distillates, along with the hydrogen sulfide and ammonia, is cooled by stream 20 (intermediate stream from the second reaction stage P), which is added to stream 9 , as well as by process heat exchange in exchangers T and U. Water (stream 10 ) is injected into stream 9 to remove most of the ammonia and an equimolar quantity of hydrogen sulfide as ammonium bisulfide solution. Stream 9 (now containing stream 20 as well) is then cooled and sent to the cold high-pressure separator (G). The overhead stream from (G) contains hydrogen, light hydrocarbonaceous gases and hydrogen sulfide (stream 11 ). If the sulfur content of the oil feed in stream 1 is high, stream 11 may be sent through an amine absorber (H) to remove hydrogen sulfide from the hydrogen-rich stream. The hydrogen-rich gas (stream 14 ) is then sent to the recycle gas compressor A for recompression and recycle back to the reactor sections in stream 16 . Hydrocarbon liquid stream (stream 12 ) from (G) is let down in pressure to recover additional hydrogen in the cold low-pressure separator (L). The sour water stream ( 13 ) which exits G contains all of the ammonium bisulfide.
Stream 15 from F, contains the bulk of the effluents from the reaction stages D and P. Stream 15 is reduced in pressure and sent to the Hot Low Pressure Separator (M). Hydrogen-rich vapor and light hydrocarbonaceous material is removed overhead through stream 23 (and cooled in exchanger X) and sent to Cold Low Pressure Separator L (combining with stream 12 ) for recovery of hydrogen. The FIGURE indicates that the overhead material in stream 37 is passed to hydrogen recovery. Bottoms from L (cooled in exchanger CC) and M (streams 27 and 25 respectively) are sent to the Product Stripper (N) for the recovery of products. The Product Stripper (N) contains packing material, useful for mass transfer in fractionation. Butane, lighter gases and part of the naphtha are removed overhead in stream 29 . Bottoms material is removed through stream 35 and heated (using heat exchanger W and furnace K) before entering fractionator ( 0 ). Bottoms from the fractionator (stream 18 ) is preheated in exchanger Y and furnace V and combined with recycle hydrogen gas (stream 17 ), then pumped back to the second stage reaction section (P). The mixture of unconverted oil from the first reaction stage and gas (stream 19 ) is first passed over a hydrocracking catalyst in zone Q of the second stage. This section is co-current in the sense that gas and liquid flow unidirectionally (downwards). After partial conversion of reactants to products, the mixture is flashed in zone R. Light gases, naphtha, kerosene and part of the diesel range material is removed via stream 20 . Heavy unconverted oil and some diesel then passes down through a distributor tray to the counter-current zone S of the second reaction stage where the downflowing liquid comes in intimate contact with pure make up hydrogen coming up the reaction zones via stream 21 . This counter-current contacting creates a very favorable environment for aromatics saturation (lower temperature and higher hydrogen partial pressure). In the counter-current reactor the forward reaction is favored for both aromatic saturation and hydrocracking. The net result is much smaller catalyst volume required to achieve complete conversion for a given product quality. In addition, the counter current reaction bed minimizes the polycyclic aromatics in the recycle stream 22 . The net result is less fouling and coking in the second stage P.
Reactor effluent from the second reaction stage (stream 22 ) is routed to the hot high-pressure separator (F) for recovery of hydrogen and liquid products. Enroute, it is cooled in exchanger Z 1 .
There are at least two, preferably three to four, beds of hydrocracking catalyst in reactor P. The catalyst system can comprise either on base or noble metals. The final reaction zone, S, is particularly attractive for noble metal application.
Feeds
A wide variety of hydrocarbon feeds may be used in the instant invention. Typical feedstocks include any heavy or synthetic oil fraction or process stream having a boiling point above 392° F. (200° C.). Such feedstocks include vacuum gas oils (VGO), heavy coker gas oil (HCGO), heavy atmospheric gas oil (AGO), light coker gas oil (LCGO), visbreaker gas oil (VBGO), demetallized oils (DMO), vacuum residua, atmospheric residua, deasphalted oil (DAO), Fischer-Tropsch streams, Light Cycle Oil, and Light Cycle Gas Oil and other FCC product streams.
Products
The process can be used over a broad range of applications as shown in the following table.
Oil Feed
Catalyst System
Operating Conditions
Products
VGO
Stage I - Hydrotreating + Hydrocracking
Stage I:
Maximum Diesel
HCGO
Stage 2 - Hydrocracking
P: 1000 psia–3000 psig
Maximum Jet + Diesel
DAO
LHSV = 0.3–4.0
Maximum Naphtha
VBGO
T: 600–850 F.
Stage 2:
DMO
P: 1000–3000 psig
LHSV = 0.5–5.0
T: 500–800 F.
AGO,
Stage I -
Stage I:
Maximum Diesel
LCO,
Hydrotreating + Hydrocracking
P: 1000 psig–3000 psig
Maximum Jet + Diesel
LCGO
Stage 2 - Hydrocracking
LHSV = 0.5–4.0
Maximum Naphtha
Or
T: 600–850 F.
Stage 2 - Zone Q Base Metal
Stage 2:
hydrocracking
P: 1000–3000 psia
Stage 2 - Zone S - Aromatic Saturation
LHSV = 0.5–5.0
(Noble-metal)
T: 500–750 F.
The process of this invention is especially useful in the production of middle distillate fractions boiling in the range of about 250-700 F (121-371 C). A middle distillate fraction is defined as having an approximate boiling range from about 250 to 700 F. At least 75 vol %, preferably 85 vol % of the components of the middle distillate have a normal boiling point of greater than 250 F. At least about 75 vol %, preferably 85 vol % of the components of the middle distillate have a normal boiling point of less than 700 F. The term “middle distillate” includes the diesel, jet fuel and kerosene boiling range fractions. The kerosene or jet fuel boiling point range refers to the range between 280 and 525 F (138-274 C). The term “diesel boiling range” refers to hydrocarbons boiling in the range from 250 to 700 F (121-371 C).
Gasoline or naphtha may also be produced in the process of this invention. Gasoline or naphtha normally boils in the range below 400° F. (204 C), or C 5 to 400° F. Boiling ranges of various product fractions recovered in any particular refinery will vary with such factors as the characteristics of the crude oil source, local refinery markets and product prices.
Conditions
Hydroprocessing conditions is a general term which refers primarily in this application to hydrocracking or hydrotreating.
Hydrotreating conditions include a reaction temperature between 400° F.-900° F. (204° C.-482° C.), preferably 600° F.-850° F. (315° C-464° C.); a pressure between 500 to 5000 psig (pounds per square inch gauge) (3.5-34.6 MPa), preferably 1000 to 3000 psig (7.0-20.8 MPa): a feed rate (LHSV) of 0.3 hr−1 to 20 hr−1 (v/v) preferably from 0.5 to 4.0; and overall hydrogen consumption 300 to 2000 SCF per barrel of liquid hydrocarbon feed (63.4-356 m 3 /m 3 feed).
Typical hydrocracking conditions (which may be found in stage 1 or stage 2) include a reaction temperature of from 400° F.-950° F. (204° C.-510° C.), preferably 600° F.-850° F. (315° C.-454° C.). Reaction pressure ranges from 500 to 5000 psig (3.5-4.5 MPa), preferably 1000-3000 psig (7.0-20.8 MPa). LHSV ranges from 0.1 to 15 hr−1 (v/v), preferably 0.5 to 5.0 hr−1. Hydrogen consumption ranges from 500 to 2500 SCF per barrel of liquid hydrocarbon feed (89.1-445 m 3 H 2 /m 3 feed).
Catalyst
A hydroprocessing zone may contain only one catalyst, or several catalysts in combination.
The hydrocracking catalyst generally comprises a cracking component, a hydrogenation component and a binder. Such catalysts are well known in the art. The cracking component may include an amorphous silica/alumina phase and/or a zeolite, such as a Y-type or USY zeolite. Catalysts having high cracking activity often employ REX, REY and USY zeolites. The binder is generally silica or alumina. The hydrogenation component will be a Group VI, Group VII, or Group VIII metal or oxides or sulfides thereof, preferably one or more of molybdenum, tungsten, cobalt, or nickel, or the sulfides or oxides thereof. If present in the catalyst, these hydrogenation components generally make up from about 5% to about 40% by weight of the catalyst. Alternatively, platinum group metals, especially platinum and/or palladium, may be present as the hydrogenation component, either alone or in combination with the base metal hydrogenation components molybdenum, tungsten, cobalt, or nickel. If present, the platinum group metals will generally make up from about 0.1% to about 2% by weight of the catalyst.
Hydrotreating catalyst, if used, will typically be a composite of a Group VI metal or compound thereof, and a Group VIII metal or compound thereof supported on a porous refractory base such as alumina. Examples of hydrotreating catalysts are alumina supported cobalt-molybdenum, nickel sulfide, nickel-tungsten, cobalt-tungsten and nickel-molybdenum. Typically, such hydrotreating catalysts are presulfided.
EXAMPLE
These are the conditions and results obtained using a Middle Eastern VGO:
Stage 1
Stage 2
Catalyst
Ni—Mo or
Ni—Mo or
Ni—W or
Ni—W
Ni—Mo—W +
Ni—Mo—W +
Zeolites
Zeolites
LHSV, hr’ (Active Catalyst)
0.7–2.0
1.0–2.0
Operating Temperatures:
SOR-EOR)° F.
500–650
650–825
(noble metal)
600–750
(base metal)
Reactor Inlet Pressure, psig
1200–2800
1000–2800
Gas/Oil Ratio (SCF/bbl)
800–9000
800–9000
Conversion, %
30–70
30–80
(per pass)
Total middle distillates from process
90–98
(250–700 F. cut)
This example illustrates a maximum distillate yield of high quality products, which may be obtained employing a second stage reactor of reduced catalyst volume. Second stage LHSV is generally higher than first stage LHSV due to a relatively contaminant-free environment (heteroatoms removed in first stage). It is also notable that when noble metal catalyst is used in the second stage, it generally operates at a lower temperature range than base metal catalyst.
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In the refining of crude oil, hydroprocessing units such as hydrotreaters and hydrocrackers are used to remove impurities such as sulfur, nitrogen, and metals from the crude oil. They are also used to convert the feed into valuable products such as naphtha, jet fuel, kerosene and diesel. The current invention provides very high to total conversion of heavy oils to products in a single high-pressure loop, using multiple reaction stages. The second stage or subsequent stages may be a combination of co-current and counter-current operation. The benefits of this invention include conversion of feed to useful products at reduced operating pressures using lower catalyst volumes. Lower hydrogen consumption also results. A minimal amount of equipment is employed. Utility consumption is also minimized.
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PRIORITY
This application claims the benefit under 35 U.S.C. §119(a) of a Korean patent application filed in the Korean Intellectual Property Office on Oct. 5, 2007 and assigned Serial No. 2007-100604, the entire disclosure of which is hereby incorporated by reference.
BACKGROUND OF THE INVENTION
1. Field of the Invention
The present invention relates to a mobile broadcasting system supporting a Broadcast Service (BCAST). More particularly, the present invention relates to a method and apparatus for providing another Service Guide (SG) through a basic SG in a mobile broadcasting system.
2. Description of the Related Art
The mobile communication market faces ever-increasing demands for new services through the recombination or convergence of existing technologies. The development of communications and broadcasting technologies has reached the point that a broadcasting service can be provided through a portable terminal (hereinafter, a mobile terminal) such as a portable phone, a Personal Digital Assistant (PDA), etc. With all of these potential and actual market demands, including the rapidly increasing user demands for multimedia service, the strategies of service providers that intend to provide new services including a broadcasting service beyond the conventional voice service, and the interests of Internet Technology (IT) companies that reinforce mobile communication businesses by meeting customer demands, the convergence between mobile communications and Internet Protocol (IP) has been a significant trend in the technological development of future-generation mobile communication systems. The resulting grand convergence, that is, the introduction of various wireless or broadcasting services to the wired communication market as well as the mobile communication market has formed the same consumer environment for various services irrespective of wired or wireless broadcasting.
The Open Mobile Alliance (OMA) is an organization that works on standardization of inter-operability between individual mobile solutions. The OMA mainly serves to establish a variety of application standards for mobile communication gaming, Internet service, etc. The OMA BCAST working group is studying a technological standard for providing a broadcasting service through a mobile terminal. That is, the OMA BCAST working group is underway to standardize techniques for providing IP-based broadcasting services in a mobile terminal environment, including providing of a Service Guide (SG), download and streaming transmission, service and content protection, service subscription roaming, etc.
Along with the market trend toward provisioning of integrated services based on wired-wireless convergence, mobile broadcasting technologies including OMA BCAST will also advance to provide services in a wired-wireless integrated environment beyond the mobile environment.
FIG. 1 is a block diagram of a conventional structure for transmitting an SG to a mobile terminal in a mobile broadcasting system.
Referring to FIG. 1 , interfaces between components (logical entities) illustrated in FIG. 1 will first be described in Table 1 and Table 2.
TABLE 1
Interface
Description
SG1
Server-to-server communications for delivering content attributes such as
description information, location information, target terminal
capabilities, target user profile, etc. either in the form of BCAST SG
fragments or in a proprietary format.
SG2
Server-to-server communications for delivering BCAST service
attributes such as service/content description information, scheduling
information, location information, target terminal capabilities, target
user profile, etc. in the form of BCAST SG fragments.
SG-B1
Server-to-server communications for either delivering Broadcast
Distribution System (BDS) specific from BDS to BCAST SG
Adaptation function, to assist SG adaptation to specific BDS, or to deliver
BCAST SG attributes to BDS for BDS specific adaptation and distribution.
SG4
Server-to-server communications for delivering provisioning
information, purchase information, subscription information,
promotional information, etc., in the form of BCAST SG fragments.
SG5
Delivery of BCAST SG through Broadcast Channel, over IP.
SG6
Delivery of BCAST SG through Interaction Channel, interactive
access to retrieve SG or additional information related to SG, for
example, by HTTP, SMS or MMS.
TABLE 2
Interface
Description
x-1 124
Reference Point between BDS Service Distribution and
BDS 122
x-2 125
Reference Point between BDS Service Distribution and
Interaction Network 123
x-3 126
Reference Point between BDS 122 and Terminal 119
x-4 127
Reference Point between BDS Service Distribution 121 and
Terminal 119 over Broadcast Channel
x-5 128
Reference Point between BDS Service Distribution and
Terminal over Interaction Channel (Air Interface 130)
x-6 129
Reference Point between Interaction Network 123 and
Terminal 119
Referring to FIG. 1 , a content creator 101 creates a broadcast service (hereinafter, a BCAST service). The BCAST service can be a conventional audio/video broadcasting service or a conventional music/data file download service. In the content creator 101 , an SG Content Creation Source (SGCCS) 102 transmits content description information, terminal capabilities information, user profiles, and content timing information required for configuring an SG for the BCAST service to an SG Application Source (SGAS) 105 of a BCAST service application 104 via an SG 1 interface 103 described in Table 1.
The BCAST service application 104 generates BCAST service data by receiving data for the BCAST service from the content creator 101 and processing the data in a form suitable for a BCAST network. The BCAST service application 104 also generates standardized meta data needed for mobile broadcasting guidance. The SGAS 105 transmits information received from the SGCCS 102 and sources required for configuring the SG, including service/content description information, scheduling information and location information, to an SG Generator (SG-G) 109 of a BCAST service distributor/adapter 108 via an SG 2 interface 106 also described in Table 1.
The BCAST service distributor/adapter 108 establishes a bearer for delivering the BCAST service data received from the BCAST service application 104 , schedules transmission of the BCAST service, and generates mobile broadcasting guide information. The BCAST service distributor/adapter 108 is connected to a Broadcast Distribution System (BDS) 122 , that transmits the BCAST service data, and to an interaction network 123 that supports bi-directional communications.
The SG generated in the SG-G 109 is provided to a mobile terminal 119 through an SG Distributor (SG-D) 110 and an SG-5 interface 117 . If the SG needs to be provided through the BDS 122 or the interaction network 123 , or the SG needs to be adapted to suit a specific system or network, it is provided to the SG-D 110 after adaptation in an SG Adapter (SG-A) 111 , or to a later-described BDS service distributor 121 via an SG-B 1 interface 116 .
A BCAST subscription manager 113 manages subscription information required for BCAST service reception, service provision information, and device information about mobile terminals to receive the BCAST service. An SG Subscription Source (SGSS) 114 of the BCAST subscription manager 113 transmits provisioning information, purchase information, subscription information, and promotional information in relation to SG generation to the SG-G 109 via an SG 4 interface 112 .
The BDS service distributor 121 distributes all received BCAST services on broadcast channels or on interaction channels. The BDS service distributor 121 is an optional entity that can be used or not depending on the type of the BDS 122 . The BDS 122 is a network over which the BCAST service is delivered. For example, the BDS 122 can be a broadcasting network such as Digital Video Broadcasting-Handheld (DVB-H), Multimedia Broadcast/Multicast Service (MBMS), or 3 rd Generation Partnership Project 2 (3GPP2) Broadcast Multicast Service (BCMCS). The interaction network 123 transmits the BCAST service in a one-to-one manner or exchanges control information and additional information associated with BCAST service reception bi-directionally. For example, the interaction network 123 can be a legacy cellular network.
In FIG. 1 , the mobile terminal 119 is a BCAST reception-enabled terminal. Depending on its performance, the mobile terminal 119 can be connected to a cellular network. The mobile terminal 119 , which includes an SG Client (SG-C) 120 , receives the SG via an SG 5 interface 117 or a notification message via an SG 6 interface 118 and appropriately operates to receive the BCAST service.
Table 3, Table 4 and Table 5 summarize the functions of major components (logical entities) illustrated in FIG. 1 , defined in the OMA BCAST standards.
TABLE 3
Logical entity
Description
Content creator
In the content creator, SGCCS may provide content attributes such
101
as content description information, target terminal capabilities,
target user profile, content timing information, etc. and may send
them over SG1 in the form of standardized BCAST SG fragments or in
a proprietary format.
BCAST service
In the BCAST service application, SGAS 105 provides
application 104
service/content description information, scheduling information,
location information, target terminal capabilities, target user
profile, etc., and sends them over SG2 106 in the form of
standardized BCAST SG fragments.
BCAST
In BCAST subscription manager, SGSS 114 provides provisioning
subscription
information, purchase information, subscription information,
manager 113
promotional information, etc., and sends them over SG4 112 in the
form of SG fragments.
TABLE 4
Logical entity
Description
SG-G 109
The SG-G in the network is responsible for receiving SG
fragments from various sources such as SGCCS 102, SGAS 105,
SGSS 114 over SG-2 and SG-4 interfaces. SG-G 109 assembles
the fragments such as services and content access information
according to a standardized schema and generates SG which is
sent to SG-D for transmission. Before transmission, it is optionally
adapted in the SG-A 111 to suit a specific BDS.
SG-C 120
The SG-C in the terminal 119 is responsible for receiving the SG
information from the underlying BDS and making the SG
available to the mobile terminal. The SG-C obtains specific SG
information. It may filter it to match the terminal specified criteria (for
example, location, user profile, terminal capabilities), or it
may simply obtain all available SG information. Commonly, the
user may view the SG information in a menu, list or tabular
format. SG-C may send a request to the network through SG-6 118
to obtain specific SG information, or the entire SG.
TABLE 5
Logical entity
Description
SG-D 110
SG-D generates an IP flow to transmit SG over the SG5 interface
118 and the broadcast channel to the SG-C 120. Before
transmission, the SG-G may send SG to SG-A 111 to adapt the SG
to suit specific BDS according to the BDS attributes sent by BDS
service distributor over SG-B1 116. The adaptation might result in
modification of SG. Note that, for adaptation purpose, the SG-A
may also send the BCAST SG attributes or BCAST SG fragments
over SG-B1 to BDS service distributor for adaptation, this
adaptation within BDS service distributor is out of the scope of
BCAST, SG-D may also receive a request for SG information, and
send the requested SG information to the terminal directly through
the interaction channel. SG-D also may filter SG information from
SG-G 109 based on End Users pre-specified profile. SG-D may
also send the SG to the BDS, which modifies the SG (e.g., by
adding BSD specific information), and further distributes the SG to the
SG-C in a BDS specific manner.
FIG. 2 illustrates a conventional OMA BCAST SG data model for generating an SG. In FIG. 2 , a solid line connecting fragments indicates cross-reference between the fragments.
Referring to FIG. 2 , the SG data model includes an Administrative Group 200 for providing upper configuration information about the entire SG, a Provisioning Group 210 for providing subscription information and purchase information, a Core Group 220 for providing core information about the SG, such as services/contents and schedules, and an Access Group 230 for providing access information by which to access the services/contents.
The Administrative Group 200 includes an SG Delivery Descriptor (SGDD) 201 and the Provisioning Group 210 includes a Purchase Item 211 , a Purchase Data 212 , and a Purchase Channel 213 .
The Core Group 220 includes a Service 221 , a Schedule 222 , and a Content 223 . The Access Group 230 is configured to include an Access 231 and a Session Description 232 .
In addition to the four groups 200 , 210 , 220 and 230 , the SG information may further include a Preview Data 241 and an Interactivity Data 251 . The above-described components of the SG are called fragments, with minimum units constituting the SG.
As to the fragments, the SGDD fragment 201 provides information on a delivery session carrying an SG Delivery Unit (SGDU) with fragments, provides grouping information about the SGDU, and an entry point for receiving a notification message.
The Service fragment 221 is an upper aggregate of content included in a broadcast service, as a core of the entire SG, and provides service content, genres, service location information, etc.
The Schedule fragment 222 provides time information of the content included in the service, such as streaming, downloading, etc.
The Content fragment 223 provides a description, a target user group, a service area, and genres for the broadcast content.
The Access fragment 231 provides access information to allow the user to access the service, and also provides information about the delivery scheme of an access session and session information about the access session.
The Session Description fragment 232 can be included in the Access fragment 231 . Alternatively, information about the location of the Session Description fragment 232 is given in the form of a Uniform Resource Identifier (URI), so that the terminal can detect the Session Description fragment 232 . In addition, the Session Description fragment 232 provides address information and codec information about multimedia content included in a session.
The Purchase Item fragment 211 groups one or more multiple services or scheduled items together, so that the user can purchase a service or a service bundle or subscribe to it.
The Purchase Data fragment 212 includes purchase and subscription information about services or service bundles, such as price information and promotion information.
The Purchase Channel fragment 213 provides access information for subscription to or purchase of a service or a service bundle.
The SGDD fragment 201 indicates an entry point for receiving the serice guide and provides grouping information about an SGDU being a container of fragments.
The Preview Data fragment 241 provides preview information about services, schedules and contents, and the Interactivity Data fragment 251 provides an interactive service during broadcasting according to services, schedules, and contents. Detailed information on the SG can be defined by various elements and attributes for providing contents and values based on the upper data model of FIG. 2 .
For convenience, although the elements and attributes for each of the fragments of the SG are not included herein, the elements and attributes do not limit the present invention, and the present invention is applicable to all necessary elements and attributes defined to provide an SG for a mobile broadcasting service.
In the course of generating a service guide in the SG-G 109 based on the SG data model and providing the fragments of the SG through the SG-D 110 and the SG-C 120 being a user terminal, the more services and contents that service providers provide, the more information is transmitted. The resulting exponential increase of the fragments of the SG in size and number may cause a significant increase in the overhead of receiving the fragments, in the time for assembling the SG and in the time and resources for displaying it in the terminal.
SUMMARY OF THE INVENTION
An aspect of the present invention is to address at least the above-mentioned problems and/or disadvantages and to provide at least the advantages described below. Accordingly, an aspect of the present invention is to provide a method and apparatus for distributing a basic SG, first of all, to provide a service efficiently and enabling reception of complementary information about the basic SG or another stand-alone SG using the basic SG in a mobile broadcasting system.
In accordance with an aspect of the present invention, a method for receiving an SG in a terminal in a mobile broadcasting system is provided. The method includes receiving a first SG, if a service fragment list extracted from the first SG includes information about at least one second SG different from the first SG, reception information about the second SG is acquired from the first SG, and the second SG is received based on the acquired reception information.
In accordance with another aspect of the present invention, a method for providing an SG in a mobile broadcasting system is provided. The method includes forming a first SG and at least one second SG, adding reception information about the second SG to the first SG, transmitting the first SG having the reception information about the second SG to a terminal and, when the terminal accesses the reception information about the second SG, the second SG is provided to the terminal.
In accordance with a further aspect of the present invention, an apparatus for receiving an SG in a terminal in a mobile broadcasting system is provided. The apparatus includes a broadcast data receiver for receiving broadcasting data, an SG receiver for acquiring a first SG and at least one second SG from the broadcast data, an SG interpreter for acquiring reception information about the second SG by interpreting the first SG, and an SG display for displaying at least one of the acquired first SG and the second SG.
In accordance with still another aspect of the present invention, an apparatus for providing an SG in a mobile broadcasting system is provided. The apparatus includes an SG generator for forming a first SG and at least one second SG and for adding reception information about the second SG to the first SG, and an SG transmitter for transmitting the first SG having the reception information about the second SG to a terminal and for providing the second SG to the terminal, when the terminal accesses the reception information about the second SG.
Other aspects, advantages, and salient features of the invention will become apparent to those skilled in the art from the following description, which, taken in conjunction with the annexed drawings, discloses exemplary embodiments of the invention.
BRIEF DESCRIPTION OF THE DRAWINGS
The above and other aspects, features and advantages of certain exemplary embodiments of the present invention will be more apparent from the following description taken in conjunction with the accompanying drawings, in which:
FIG. 1 is a diagram illustrating the logical structure of conventional OMA BCAST SG functions;
FIG. 2 is a data model of a conventional OMA BCAST SG;
FIG. 3 illustrates a method for receiving an SG using a basic SG according to an exemplary embodiment of the present invention;
FIG. 4 is a flowchart illustrating an operation for receiving an SG using a basic SG in a terminal according to an exemplary embodiment of the present invention;
FIG. 5 is an exemplary view of information in a Service fragment in an OMA BCAST SG data model;
FIG. 6 is an exemplary view of information in an Access fragment in an OMA BCAST SG data model; and
FIG. 7 is a block diagram of a system and a terminal according to an exemplary embodiment of the present invention.
Throughout the drawings, the same drawing reference numerals will be understood to refer to the same elements, features and structures.
DETAILED DESCRIPTION OF EXEMPLARY EMBODIMENTS
The following description with reference to the accompanying drawings is provided to assist in a comprehensive understanding of exemplary embodiments of the invention as defined by the claims and their equivalents. It includes various specific details to assist in that understanding but these are to be regarded as merely exemplary. Accordingly, those of ordinary skill in the art will recognize that various changes and modifications of the embodiments described herein can be made without departing from the scope and spirit of the invention. Also, descriptions of well-known functions and constructions are omitted for clarity and conciseness.
While a description of exemplary embodiments of the present invention will be made herein using the names of the entities defined in the 3GPP, which is the asynchronous mobile communication standard, or defined in the OMA BCAST, a standard group for the application of mobile terminals, the stated standards and entity names thereof are not intended to limit the scope of the present invention, and the present invention can be applied to any system having a similar technical background.
For a better understanding of exemplary embodiments of the present invention, a message scheme table used in the present invention will be described with reference to Table 6.
TABLE 6
Name
Type
Category
Cardinality
Description
Data Type
In Table 6, the term “Name” indicates the name of an entity being an element or an attribute in a message. The term “Type” indicates whether the entity is an element or an attribute. If the entity is an element, it has a value of E 1 , E 2 , E 3 or E 4 , wherein E 1 indicates an upper element in the entire message, E 2 indicates a sub-element of E 1 , E 3 indicates a sub-element of E 2 , and E 4 indicates a sub-element of E 3 . If the entity is an attribute, its Type is A. For example, A under E 1 indicates an attribute of E 1 . The term “Category” indicates whether the element or attribute is mandatory or optional. If the element or attribute is mandatory, Category is M and if it is optional, Category is O. The term “Cardinality” indicates the relationship between elements, and has a value of 0, 0 . . . 1, 1, 0 . . . n, or 1 . . . n. Herein, 0 means an optional relationship, 1 means a mandatory relationship, and n means that a plurality of values can be used. For example, 0 . . . n means that the element may have no value, or n values. The term “Description” describes the element or attribute in plain text and the term “Data Type” defines the data structure of the element or attribute.
FIG. 3 illustrates a method for receiving an SG and a method for providing another SG using a basic SG according to an exemplary embodiment of the present invention.
Referring to FIG. 3 , the SG-C of a terminal (not shown) in a mobile broadcasting system accesses an Announcement Session 301 and receives an SGDD 310 in the Announcement Session 301 . As stated before, the SGDD 310 includes an SGDU list and information about delivery sessions carrying SGDUs. In the exemplary implementation of FIG. 3 , the SGDD 310 has an SGDU list containing fragments of a basic SG and information about a delivery session 302 (Delivery Session X) carrying intended SGDUs. The terminal interprets the SGDD 310 , accesses Delivery Session X, and receives SGDUs 311 for the basic SG from Delivery Session X. The terminal then extracts fragments for the basic SG from the SGDUs 311 and displays a final basic SG 320 to the user.
The basic SG 320 may include complementary information about a service or provide information about how to access an SG provided by another service provider. In FIG. 3 , the terminal can detect reception information about a first SG 321 (SG 1 ) and a second SG 322 (SG 2 ) in the basic SG 320 . The reception information about SG 1 includes information about a delivery session 303 (Delivery Session Y) carrying SGDUs 312 for SG 1 and the reception information about SG 2 includes information about a delivery session 304 (Delivery Session Z) carrying SGDUs 313 for SG 2 . The terminal accesses Delivery Session Y or Delivery Session Z, receives the SGDUs 312 for SG 1 or the SGDUs 313 for SG 2 , and displays SG 1 or SG 2 to the user.
FIG. 4 is a flowchart illustrating an SG reception method in a terminal according to an exemplary embodiment of the present invention.
Referring to FIG. 4 , the terminal accesses an Announcement Session and receives an SGDD in the Announcement Session in step 401 . In step 402 , the terminal interprets the SGDD and detects information about a delivery session and SGDUs that carry fragments for an SG. The terminal receives all of the SGDUs indicated by the SGDD from the delivery session in step 403 . The terminal extracts fragments from the SGDUs and configures an SG by interpreting the fragments in step 404 and checks a list of Service fragments in the SG in step 405 . FIG. 5 is a diagram illustrating exemplary upper element values and attribute values of a Service fragment.
In step 406 , the terminal determines whether a ServiceType 501 ( FIG. 5 ) set to Service Guide exists by interpreting the Service fragments of the Service fragment list. In the absence of the ServiceType 501 set to Service Guide, it can be considered that the SG contains only information that the terminal has received from a service provider, without information about provisioning of another SG. In this case, the terminal displays the SG to the user in step 407 .
In the alternative, if the ServiceType 501 set to Service Guide does exist, which implies the inclusion of information about reception of and access to another SG in the SG, the terminal detects all Access fragments associated with the Service fragment with the ServiceType 501 set to Service Guide in step 408 . FIG. 6 is a diagram illustrating exemplary upper element values and attribute values of an Access fragment.
In step 409 , the terminal determines the value of a ServiceClass 601 in each of the detected Access fragments. If the ServiceClass 601 is ‘urn:oma:oma_bsc:sg:1.0’, this means that a delivery session corresponding to access information included in the Access fragment carries a stand-alone SG. If the ServiceClass 601 is ‘urn:oma:oma_bsc:csg:1.0’, this means that the delivery session corresponding to the access information included in the Access fragment carries a complementary SG that provides complementary information about the SG. Thus, the terminal acquires preliminary information about the stand-alone SG or the complementary SG by checking a sub-element of the ServiceClass, ReferredSGInfo in step 410 , which is given as follows.
TABLE 7
Data
Name
Type
Category
Cardinality
Description
Type
Access
E
‘Access’ fragment
Contains the following
attributes:
id
version
validFrom
validTo
Contains the following
elements:
AccessType
KeyManagementSystem
EncryptionType
ServiceReference
ScheduleReference
TerminalCapabilityRequirement
BandwidthRequirement
ServiceClass
PreviewDataReference
NotificationReception
PrivateExt
id
A
NM/
1
ID of the ‘Access’ fragment.
anyURI
TM
The value of this attribute
SHALL be globally unique.
version
A
NM/
1
Version of this fragment. The
unsignedInt
TM
newer version overrides the
older one starting from the
time specified by the
validFrom attribute, or as soon
as it has been received if no
validFrom attribute is given.
validFrom
A
NM/
0 . . . 1
The first moment when this
unsignedInt
TM
fragment is valid. If not given,
the validity is assumed to have
started at some time in the past.
This field contains the 32bits
integer part of an NTP time
stamp.
validTo
A
NM/
0 . . . 1
The last moment when this
unsignedInt
TM
fragment is valid. If not given,
the validity is assumed to end
in undefined time in the future.
This field contains the 32bits
integer part of an NTP time
stamp.
AccessType
E1
NM/
1
Defines the type of access.
TM
Note: Either one of
‘BroadcastServiceDelivery’ or
‘UnicastServiceDelivery’ but
not both SHALL be
instantiated. Implementation in
XML Schema should use
<choice>.
Contains the following
elements:
BroadcastServiceDelivery
UnicastServiceDelivery
BroadcastServiceDelivery
E2
NM/
0 . . . 1
This element is used for the
TM
indication of IP transmission.
Contains the following
elements:
BDSType
SessionDescription
FileDescription
BDSType
E3
NM/
0 . . . 1
Identifier of the type of
TM
underlying distribution system
that this ‘Access’ fragment
relates to.
Contains the following
element:
Type
Version
Type
E4
NM/
0 . . . 1
Type of underlying BDS,
unsignedByte
TM
possible values:
0. IPDC over DVB-H
1. 3GPP MBMS
2. 3GPP2 BCMCS
3-127. reserved for future use
128-255. reserved for
proprietary use
Version
E4
NM/
0 . . . N
Version of underlying BDS.
string
TM
For instance, possible values
are Rel-6 or Rel-7 for MBMS
and 1x or HRPD or Enhanced
HRPD for BCMCS.
SessionDescription
E3
NM/
0 . . . 1
Reference to or inline copy of
TM
a Session Description
information associated with
this ‘Access’ fragment that the
media application in the
terminal uses to access the
service.
Note: a referenced
‘SessionDescription’ fragment
may be delivered in two ways:
via broadcast or via fetch over
interaction channel.
In the case of fetch over
interaction channel, the
‘SessionDescription’ fragment
can be acquired by accessing
the URI (given as attribute of
the different Session
Description reference
elements).
Contains the following
elements:
SDP
SDPRef
USBDRef
ADPRef
The presence of elements
‘SDP’ and ‘SDPRef’ are
mutually exclusive.
If ‘SessionDescription’
element is provided, and the
‘type’ attribute has one of the
values “4” or “5”, the terminal
MAY use it instead of fetching
Session Description
information via RTSP.
SDP
E4
NM/
0 . . . 1
An inlined Session Description
string
TM
in SDP format [RFC 4566] that
SHALL either be embedded in
a CDATA section or base64-
encoded.
Contains the following
attribute:
encoding
encoding
A
NM/TM
0 . . . 1
This attribute signals the way
string
the Session Description has
been embedded:
It SHALL NOT be
present when the Session
Description is embedded into a
CDATA section.
It SHALL be present
and set to “base64” in case the
Session Description is base64-
encoded.
SDPRef
E4
NM/TM
0 . . . 1
Reference to a Session
Description in SDP format
[RFC 4566]
Contains the following
attributes:
uri
idRef
If both ‘uri’ and ‘idRef’ are
present, the referenced Session
Description information
SHALL be identical.
uri
A
NM/
0 . . . 1
The URI referencing an
anyURI
TM
external resource containing
SDP information. This URI is
used for interactive retrieval.
idRef
A
NM/
0 . . . 1
The id of the referenced
anyURI
TM
‘SessionDescription’ fragment
if the fragment is delivered
over the broadcast channel in
SGDU, globally unique
USBDRef
E4
NM/TM
0 . . . 1
Reference to an instance of
MBMS User Service Bundle
Description as specified in
[26.346] section 5.2.2, with the
restrictions defined in section
5.1.2.5 of this spec.
Contains the following
attributes:
uri
idRef
If both ‘uri’ and ‘idRef’ are
present, the referenced Session
Description information
SHALL be identical.
uri
A
NM/
0 . . . 1
The URI referencing an
anyURI
TM
external resource containing
MBMS-USBD information.
This URI is used for interactive
retrieval.
idRef
A
NM/
0 . . . 1
The id of the referenced
anyURI
TM
‘SessionDescription’ fragment
if the fragment is delivered
over the broadcast channel in
SGDU, globally unique
ADPRef
E4
NM/TM
0 . . . 1
Reference to an
AssociatedDeliveryProcedure
for File and Stream
Distribution as specified in
[BCAST10-Distribution]
section 5.3.4.
Contains the following
attributes:
uri
idRef
If both ‘uri’ and ‘idRef’ are
present, the referenced Session
Description information
SHALL be identical.
uri
A
NM/
0 . . . 1
The URI referencing an
anyURI
TM
external resource containing
AssociatedDeliveryProcedure
for File and Stream
Distribution. This URI is used
for interactive retrieval.
idRef
A
NM/
0 . . . 1
The id of the
anyURI
TM
referenced ‘SessionDescription’
fragment if the fragment is
delivered over the broadcast
channel in SGDU, globally
unique
FileDescription
E3
NO/
0 . . . 1
File metadata for file delivery
TM
sessions.
This element SHALL be
provided when ALC is used.
This element SHALL NOT be
used in conjunction with
FLUTE.
The network SHALL support
‘FileDescription’ element and
all its sub-elements and
attributes if ALC is used for
File Distribution function.
Contains the following
attributes:
Content-Type
Content-Encoding
FEC-OTI-FEC-Encoding-ID
FEC-OTI-FEC-Instance-ID
FEC-OTI-Maximum-Source-
Block-Length
FEC-OTI-Encoding-Symbol-
Length
FEC-OTI-Max-Number-of-
Encoding-Symbols
FEC-OTI-Scheme-Specific-
Info
Contains the following
elements:
File
Content-
A
NO/
0 . . . 1
See RFC 3926, section 3.4.2
string
Type
TM
Content-
A
NO/
0 . . . 1
See RFC 3926, section 3.4.2
string
Encoding
TM
FEC-OTI-
A
NO/TM
0 . . . 1
See RFC 3926, section 3.4.2
unsignedByte
FEC-
Encoding-
ID
FEC-OTI-
A
NO/
0 . . . 1
See RFC 3926, section 3.4.2
unsignedLong
FEC-
TM
Instance-ID
FEC-OTI-
A
NO/
0 . . . 1
See RFC 3926, section 3.4.2
unsignedLong
Maximum-
TM
Source-
Block-
Length
FEC-OTI-
A
NO/
0 . . . 1
See RFC 3926, section 3.4.2
unsignedLong
Encoding-
TM
Symbol-
Length
FEC-OTI-
A
NO/
0 . . . 1
See RFC 3926, section 3.4.2
unsignedLong
Max-
TM
Number-of-
Encoding-
Symbols
FEC-OTI-
A
NO/TM
0 . . . 1
This attribute MAY be used to
base64
Scheme-
communicate FEC information
Binary
Specific-
which is not adequately
Info
represented by the other
attributes related to FEC.
File
E4
NO/
1 . . . N
Parameters of a file.
TM
Contains the following
attributes:
Content-Location
TOI
Content-Length
Transfer-Length
Content-Type
Content-Encoding
Content-MD5
FEC-OTI-FEC-Encoding-ID
FEC-OTI-FEC-Instance-ID
FEC-OTI-Maximum-Source-
Block-Length
FEC-OTI-Encoding-Symbol-
Length
FEC-OTI-Max-Number-of-
Encoding-Symbols
FEC-OTI-Scheme-Specific-
Info
Content-
A
NO/
1
See RFC 3926, section 3.4.2
anyURI
Location
TM
TOI
A
NO/
1
See RFC 3926, section 3.4.2
positiveInteger
TM
Content-
A
NO/
0 . . . 1
See RFC 3926, section 3.4.2
unsignedLong
Length
TM
Transfer-
A
NO/
0 . . . 1
See RFC 3926, section 3.4.2
unsignedLong
Length
TM
Content-
A
NO/
0 . . . 1
See RFC 3926, section 3.4.2
string
Type
TM
Content-
A
NO/
0 . . . 1
See RFC 3926, section 3.4.2
string
Encoding
TM
Content-
A
NO/
0 . . . 1
See RFC 3926, section 3.4.2
base64
MD5
TM
Binary
FEC-OTI-
A
NO/TM
0 . . . 1
See RFC 3926, section 3.4.2
unsignedByte
FEC-
Encoding-
ID
FEC-OTI-
A
NO/
0 . . . 1
See RFC 3926, section 3.4.2
unsignedLong
FEC-
TM
Instance-ID
FEC-OTI-
A
NO/
0 . . . 1
See RFC 3926, section 3.4.2
unsignedLong
Maximum-
TM
Source-
Block-
Length
FEC-OTI-
A
NO/
0 . . . 1
See RFC 3926, section 3.4.2
unsignedLong
Encoding-
TM
Symbol-
Length
FEC-OTI-
A
NO/
0 . . . 1
See RFC 3926, section 3.4.2
unsignedLong
Max-
TM
Number-of-
Encoding-
Symbols
FEC-OTI-
A
NO/TM
0 . . . 1
This attribute MAY be used to
base64
Scheme-
communicate FEC information
Binary
Specific-
which is not adequately
Info
represented by the other
attributes related to FEC.
UnicastServiceDelivery
E2
NM/
0 . . . N
This element indicates which
TM
server and/or protocol is used
for delivery of service over
Interaction Channel.
Contains the following
attribute:
type
Contains the following
elements:
AccessServerURL
SessionDescription
ServiceAccessNotificationURL
type
A
NM/
1
Specifies transport mechanism
unsignedByte
TM
that is used for this access.
0 - HTTP
1 - WAP 1.0
2 - WAP 2.x
3 - Generic RTSP to initialize
RTP delivery
4 - RTSP to initialize RTP
delivery as per 3GPP-PSS
(3GPP packet-switched
streaming service)
5 - RTSP to initialize RTP
delivery as per 3GPP2-MSS
(3GPP2 multimedia streaming
services)
6 - FLUTE over Unicast
7-127 Reserved for future use
128-255 Reserved for
proprietary use
Note: Specification or
negotiation of ports used for
unicast service delivery is
handled by the used unicast
distribution mechanisms. For
example, RTSP and PSS based
systems (values 3 and 4) do
port negotiation within the
RTSP signalling exchange.
AccessServerURL
E3
NM/
0 . . . N
Server URL from which the
anyURI
TM
terminal can receive the
service via the Interaction
Network as specified in section
5.5 and 6.5 of [BCAST10-
Distribution].
For example,
AccessServerURL can be an
HTTP URL pointing to
downloadable content, or an
RTSP URL pointing to a
streaming server for starting a
streaming session.
If ‘type’ attribute has one of
the values “3”, “4” or “5”
either E3 element
‘SessionDescription’ or E3
element ‘AccessServerURL’ or
both SHALL be instantiated.
SessionDescription
E3
NM/
0 . . . 1
Reference to or inline copy of
TM
a Session Description
information associated with
this ‘Access’ fragment that the
media application in the
terminal uses to access the
service.
Note: a referenced
‘SessionDescription’ fragment
may be delivered in two ways:
via broadcast or via fetch over
interaction channel.
In the case of fetch over
interaction channel, the
‘SessionDescription’ fragment
can be acquired by accessing
the URI (given as attribute of
the different Session
Description reference
elements).
Contains the following
elements:
SDP
SDPRef
USBDRef
ADPRef
The presence of elements
‘SDP’ and ‘SDPRef’ are
mutually exclusive.
If ‘SessionDescription’ E3
element is instantiated, and the
‘type’ attribute has one of the
values “3”, “4” or “5”, the
terminal MAY use it to acquire
Session Description
information (including RTSP
URL) via broadcast channel or
interaction channel using
‘SDPRef’ or use inlined SDP
(E4 element ‘SDP’), instead of
fetching Session Description
information via RTSP. Further,
in this case,
‘AccessServerURL’ E3
element MAY NOT be present.
If ‘type’ attribute has one of
the values “3”, “4” or “5”
either E3 element
‘SessionDescription’ or E3
element ‘AccessServerURL’ or
both SHALL be instantiated.
SDP
E4
NM/
0 . . . 1
An inlined Session Description
string
TM
in SDP format [RFC 4566] that
SHALL either be embedded in
a CDATA section or base64-
encoded.
Contains the following
attribute:
encoding
encoding
A
NM/TM
0 . . . 1
This attribute signals the way
string
the Session Description has
been embedded:
It SHALL NOT be
present when the Session
Description is embedded into a
CDATA section.
It SHALL be present
and set to “base64” in case the
Session Description is base64-
encoded.
SDPRef
E4
NM/
0 . . . 1
Reference to a Session
TM
Description in SDP format
[RFC 4566]
Contains the following
attributes:
uri
idRef
If both ‘uri’ and ‘idRef’ are
present, the referenced Session
Description information
SHALL be identical.
uri
A
NM/
0 . . . 1
The URI referencing an
anyURI
TM
external resource containing
SDP information. This URI is
used for interactive retrieval.
The terminal SHALL support
HTTP URI for this purpose.
idRef
A
NM/
0 . . . 1
The id of the referenced
anyURI
TM
‘SessionDescription’ fragment
if the fragment is delivered
over the broadcast channel in
SGDU, globally unique
USBDRef
E4
NM/TM
0 . . . 1
Reference to an instance of
MBMS User Service Bundle
Description as specified in
[26.346] section 5.2.2, with the
restrictions defined in section
5.1.2.5 of this spec.
Contains the following
attributes:
uri
idRef
If both ‘uri’ and ‘idRef’ are
present, the referenced Session
Description information
SHALL be identical.
uri
A
NM/
0 . . . 1
The URI referencing an
anyURI
TM
external resource containing
MBMS-USBD information.
This URI is used for interactive
retrieval.
idRef
A
NM/
0 . . . 1
The id of the referenced
anyURI
TM
‘SessionDescription’ fragment
if the fragment is delivered
over the broadcast channel in
SGDU, globally unique
ADPRef
E4
NM/TM
0 . . . 1
Reference to an
AssociatedDeliveryProcedure
for File and Stream
Distribution as specified in
[BCAST10-Distribution]
section 5.3.4.
Contains the following
attributes:
uri
idRef
If both ‘uri’ and ‘idRef’ are
present, the referenced Session
Description information
SHALL be identical.
uri
A
NM/
0 . . . 1
The URI referencing an
anyURI
TM
external resource containing
AssociatedDeliveryProcedure
for File and Stream
Distribution. This URI is used
for interactive retrieval.
idRef
A
NM/
0 . . . 1
The id of the
anyURI
TM
referenced ‘SessionDescription’
fragment if the fragment is
delivered over the broadcast
channel in SGDU, globally
unique
ServiceAccessNotificationURL
E3
NM/
0 . . . N
URL that the terminal
anyURI
TM
SHOULD use to notify the
BSD/A when it accesses
(switches to) this service over
this unicast access. The
‘ServiceAccessNotificationURL’
MAY be used in
conjunction with
‘UnicastServiceDelivery’ types
3, 4, 5 or 6. If used, the device
SHOULD NOT use RTSP
TEARDOWN and RTSP
SETUP to terminate an
existing RTSP stream and set
up a new one.
The terminal SHALL NOT use
this URL for notification
without user consent.
Note: This URL can for
example be used for initiating
server-managed channel
switching in unicast
transmission.
KeyManagementSystem
E1
NM/
0 . . . N
Information of Key
TM
Management System(s)(KMS)
that can be used to contact the
BCAST Permissions Issuer
and, in case of the SmartCard
Profile whereby GBA is used
for SMK derivation, whether
GBA_U is mandatory or
whether either GBA_ME or
GBA_U can be used.
Note that the BCAST
Permissions Issuer can support
more than one KMS.
If KeyManagementSystem is
not specified, it means no
service or content protection is
applied.
Multiple occurrences of
‘KeyManagementSystem’
elements are allowed within
this fragment only if all of the
‘KeyManagementSystem’
elements have different
‘kmsType’ attribute.
Contains the following
elements:
ProtectionKeyID
PermissionsIssuerURI
TerminalBindingKeyID
Contains the following
attributes:
kmsType
protectionType
kmsType
A
NM/
1
Identifies the type of Key
unsignedByte
TM
Management System(s)(KMS).
Possible values:
0. oma-bcast-drm-pki
Indicates OMA BCAST DRM
profile (Public Key
Infrastructure)
1. oma-bcast-gba_u-mbms
Indicates BCAST Smartcard
profile using GBA_U
(Symmetric Key
Infrastructure)
2. oma-bcast-gba_me-mbms
Indicates BCAST Smartcard
profile using GBA_ME
3. oma-bcast-prov-bcmcs
Indicates provisioned 3GPP2
BCMCS SKI
4-127 Reserved for future use
128-255 Reserved for
proprietary use
protectionType
A
NM/
1
Specifies the protection type
unsignedByte
TM
offered by the KMS.
Values:
0. Content protection only, as
defined by the LTKM
(protection_after_reception in
STKM = 0x00 or 0x01
[BCAST10-ServContProt])
1. Service protection only
(protection_after_reception in
STKM = 0x03 [BCAST10-
ServContProt])
2. Content protection as
defined by LTKM, plus
playback of protected
recording permission
(protection_after_reception in
STKM = 0x02 [BCAST10-
ServContProt])
3-127 Reserved for future use
128-255 Reserved for
proprietary use
This attribute may also be used
for presentation purpose to
users, to indicate whether the
content item(s), associated
with the referenced Schedule
by this ‘Access’ fragment, is
protected or not.
Permissions
E2
NM/TM
1
The address of the BCAST
anyURI
IssuerURI
Permissions Issuer to which
requests for key material,
tokens and/or consumption
rules should be sent by the
BCAST Terminal.
Contains the following
attribute:
type
type
A
NM/TM
1
The type of the
boolean
PermissionsIssuerURI,
identified by the following
values:
false-DRM Profile
true - Smartcard Profile
Note: In the case of the DRM
Profile, the
PermissionsIssuerURI
corresponds to the
RightsIssuerURL as defined by
[DRMDRM-v2.0]. In the case
of the Smartcard Profile, the
PermissionsIssuerURI
corresponds to the network
entity (i.e. the BSM) to which
all BCAST Service
Provisioning messages are sent
by the terminal.
ProtectionKeyID
E2
NO/
0 . . . N
Key identifier needed to access
base64
TO
protected content. This
Binary
information allows the terminal
to determine whether or not it
has the correct key material to
access services within a
PurchaseItem. In a scenario
where this fragment is shared
among multiple service
providers, different key
identifiers from the different
service providers to access this
specific protected
service/content may be mixed
in this element and the terminal
SHOULD be able to sort out
the key identifiers associated
with the terminal's affiliated
service provider based on the
Key Domain ID. How this is
used is out of scope and is left
to implementation.
The network and terminal
SHALL support this element in
case the Smartcard Profile is
supported [BCAST10-
ServContProt].
The protection key identifiers
to access a specific service or
content item SHALL only be
signalled in one of the
following fragment types:
‘Service’, ‘Content’,
‘PurchaseItem’ or ‘Access’
fragments, but not mixed.
Contains the following
attribute:
type
type
A
NM/TM
1
Type of ProtectionKeyID:
unsignedByte
0: ProtectionKeyID = Key
Domain ID concatenated with
SEK/PEK ID, where both
values are as used in the
Smartcard Profile [BCAST10-
ServContProt].
1-127 Reserved for future use
128-255 Reserved for
proprietary use
TerminalBindingKeyID
E2
NO/
0 . . . 1
Number identifying the
unsignedInt
TO
Terminal Binding Key ID
(TBK ID) that is needed to
access the service.
If the element is absent, no
TerminalBindingKey is used.
Both the network and the
terminal with the Smartcard
Profile SHALL support this
element. It is TM for terminals
with the smartcard profile.
This element does not apply to
the DRM profile.
Contains the following
attribute:
tbkPermissionsIssuerURI
tbkPermissionsIssuerURI
A
NO/
0 . . . 1
Specifies the Permissions
anyURI
TM
Issuer URI for the
TerminalBindingKey if it is
different from the
‘PermissionsIssuerURI’ sub-
element of the
‘KeyManagementSystem’
element.
If the attribute is not present
the same
‘PermissionsIssuerURI’
indicated for
KeyManagementSystem is
used to acquire both SEK/
PEK and TerminalBindingKey.
Encryption
E1
NM/
0 . . . N
Specifies which encryption
unsignedByte
Type
TM
methods the terminal is to be
able to support in order to
utilize this Access. Contains
the same value as
traffic_protection_protocol
signalled in STKM.
0 - IPsec
1 - STRP
2 - ISMACryp
3 - DCF
4-255 - Reserved for future
use.
If this element is not present,
this Access is not encrypted.
ServiceReference
E1
NM/
0 . . . N
Reference to the ‘Service’
TM
fragment(s) to which the
‘Access’ fragment belongs.
Either one of
‘ServiceReference’ or
‘ScheduleReference’, or
neither, but not both SHALL
be instantiated.
Each ‘Service’ fragment
SHALL be associated to at
least one ‘Access’ fragment to
enable the terminal to access
the Service.
A single ‘Access’ fragment
MAY reference to multiple
‘Service’ fragments. This is
used when there are several
independent descriptions of a
single Service.
idRef
A
NM/
1
Identification of the ‘Service’
anyURI
TM
fragment which this ‘Access’
fragment is associated with.
ScheduleReference
E1
NM/
0 . . . N
Reference to the ‘Schedule’
TM
fragment(s) to which the
‘Access’ fragment belongs.
This provides a reference to a
‘Schedule’ fragment to
temporarily override the
default ‘Access’ fragment of
the Service addressed by the
Schedule.
Either one of
‘ServiceReference’ or
‘ScheduleReference’, or
neither, but not both SHALL
be instantiated. Note:
Implementation in XML
Schema using <choice>.
Contains the following
attribute:
idRef
Contains the following
element:
DistributionWindowID
idRef
A
NM/
1
Identification of the ‘Schedule’
anyURI
TM
fragment which the ‘Access’
fragment relates to.
DistributionWindowID
E2
NO/
0 . . . N
Relation reference to the
unsignedInt
TM
DistributionWindowID to
which the ‘Access’ fragment
belongs.
The ‘DistributionWindowID’
element declared in this
element SHALL be the
complete collection or a subset
of the DistributionWindow ids
declared in the ‘Schedule’
fragment, to which ‘idRef’
reference belongs.
TerminalCapabilityRequirement
E1
NO/
0 . . . 1
Terminal capabilities needed to
TM
consume the service or content.
This element provides a hint to
the terminal of what is needed
to apply to consumption
method represented by this
‘Access’ fragment. It is out of
scope of this specification how
the terminal applies this
information.
For video and audio, the media
type and the related ‘type’
attribute in the SDP (see
section 5.1.2.5) signal the
audio/video decoder. This way,
these parameters complement
the
TerminalCapabilityRequirement.
Additionally, the
complexities of the audio/video
streams are described here if
they differ from the
complexities which can be
derived from the media type
attributes in the SDP (e.g.
level). In this case, the
parameters defined in the
‘Access’ fragment take
priority.
Contains the following
elements:
Video
Audio
DownloadFile
Video
E2
NO/
0 . . . 1
Video codec capability related
TM
requirements
Contains the following
elements:
Complexity
Complexity
E3
NO/
1
The complexity the video
TM
decoder has to deal with. It is
RECOMMENDED that this
element is included if the
complexity indicated by the
MIME type parameters in the
SDP differs from the actual
complexity.
Contains the following
elements:
Bitrate
Resolution
MinimumBufferSize
Bitrate
E4
NO/
0 . . . 1
The total bit-rate of the video
TM
stream.
Contains the following
attributes:
average
maximum
average
A
NO/
0 . . . 1
The average bit-rate in kbit/s
unsignedShort
TM
maximum
A
NO/
0 . . . 1
The maximum bit-rate in kbit/s
unsignedShort
TM
Resolution
E4
NO/
0 . . . 1
The resolution of the video.
TM
Contains the following
attributes:
horizontal
vertical
temporal
horizontal
A
NO/
1
The horizontal resolution of
unsignedShort
TM
the video in pixels.
vertical
A
NO/
1
The vertical resolution of the
unsignedShort
TM
video in pixels.
temporal
A
NO/
1
The maximum temporal
decimal
TM
resolution in frames per
second.
MinimumBufferSize
E4
NO/
0 . . . 1
The minimum decoder buffer
unsignedInt
TM
size needed to process the
video content in kbytes.
Audio
E2
NO/
0 . . . 1
The audio codec capability.
TM
Contains the following
element:
Complexity
Complexity
E3
NO/
1
The complexity the audio
TM
decoder has to deal with. It is
RECOMMENDED that this
element is included if the
complexity indicated by the
MIME type parameters in the
SDP differs from the actual
complexity.
Contains the following
elements:
Bitrate
MinimumBufferSize
Bitrate
E4
NO/
0 . . . 1
The total bit-rate of the audio
TM
stream.
Contains the following
attributes:
average
maximum
average
A
NO/
0 . . . 1
The average bit-rate in kbit/s
unsignedShort
TM
maximum
A
NO/
0 . . . 1
The maximum bit-rate in kbit/s
unsignedShort
TM
MinimumBufferSize
E4
NO/
0 . . . 1
The minimum decoder buffer
unsignedInt
TM
size needed to process the
audio content in kbytes.
DownloadFile
E2
NO/
0 . . . 1
The required capability for the
TM
download files.
Contains the following
elements:
MIMEType
MIMEType
E3
NO/
1 . . . N
Assuming a download service
string
TM
consists of a set of files with
different MIME types which
together make up the service,
the terminal must support all of
these MIME types in order to
be able to present the service to
the user.
The format of this string
SHALL follow the
‘Content-Type’ syntax defined
in [RFC 2045].
Additionally the
‘Content-Type’ MAY be
augmented as defined in [RFC
4281].
In the latter case the ‘Content-
Type’ SHALL begin by
“audio/3gpp”,
“audio/3gpp2”,
“video/3gpp”,
“video/3gpp2”
Contains the following
attribute:
codec
codec
A
NO/
0 . . . 1
The codec parameters for the
string
TM
associated MIME Media type.
If the file's MIME type
definition specifies mandatory
parameters, these MUST be
included in this string.
Optional parameters containing
information that can be used to
determine as to whether the
terminal can make use of the
file SHOULD be included in
the string. One example of the
parameters defined for
audio/3GPP, audio/3GPP2,
video/3GPP, video/3GPP2 is
specified in [RFC4281].
BandwidthRequirement
E1
NO/
0 . . . 1
Specification of needed
unsignedInt
TM
network bandwidth in kbit/s to
the access channel described in
this fragment.
A broadcast service can
include multiple accessible
streams (same content) with
different bandwidth, so that the
terminal can make a choice
depending on its current
reception condition.
ServiceClass
E1
NM/
1
The ServiceClass identifies the
TM
class of service. This
identification is more detailed
than the ‘ServiceType’ element
in the ‘Service’ fragment and
allows the association of
service/access combination to
specific applications.
Contains the following
attributes:
urn
Contains the following
elements:
ReferredSGInfo
urn
A
NM/TM
1
Specifies the ServiceClass as
string
defined in OMNA registry (see
Appendix E). The Terminal
SHALL be able to interpret the
information.
ReferredSG
E2
NM/
0 . . . 1
Specifies the additional
Info
TM
information for referred
Service Guide. This element
SHALL be present only when
‘ServiceClass’ is
“urn:oma:bcast:oma_bsc;csg:1.0”
or
“urn:oma:bcasst:oma_bsc:sg:1.0”.
Contains the following
elements:
BSMSelector
ServiceIDRef
ServiceGuideDeliveryUnit
BSMSelector
E3
NM/
0 . . . N
Specifies the BSM associated
TM
with the referred Service
Guide.
Contains the following
attribute:
idRef
idRef
A
NM/TM
1
Reference to the identifier of
anyURI
the BSMSelector declared
within the ‘BSMList’ in the
ServiceGuideDeliverDescriptor
which is used for receiving
this fragment.
SPName
E4
NO/TM
0 . . . 1
Provides a user readable name
string
for the BSMSelector, possibly
multiple language. Values
should be the same as provided
in
ServiceGuideDeliveryDescriptor
referenced by idRef above.
This element can be used to
provide information to the user
for selecting relevant referred
Service Guide.
ServiceIDRef
E3
NM/TM
0 . . . 1
The value of this field is the
anyURI
fragment ID of the ‘Service’
fragment related to the referred
Service Guide.
ServiceGuideDeliveryUnit
E3
NM/
1 . . . N
A group of fragments.
TM
Contains the following
attributes:
transportObjectID,
versionIDLength,
contentLocation,
validFrom,
validTo
Contains the following
element:
Fragment
transportObjectID
A
NM/
0 . . . 1
The transport object ID of the
positiveInteger
TM
Service Guide Delivery Unit
carrying the declared
fragments within this group.
If ‘FileDescription’ is present
in this fragment, then the value
of ‘transportObjectID’ SHALL
match the value of the TOI
paired in the FDT instance
with the ‘Content-Location’
having as its value the value of
the ‘contentLocation’ attribute
below.
If and only if element E2
‘Transport’ is instantiated,
SHALL this attribute be
instantiated.
versionIDLength
A
NO/
0 . . . 1
Indicates the number of least
unsignedLong
TO
significant bits representing the
version ID in the
transportObjectID, when Split
TOI is used. If this element is
omitted, the terminal assumes
Split-TOI is not used.
contentLocation
A
NM/TM
1
This is the location of the
anyURI
Service Guide Delivery Unit. It
corresponds to the ‘Content-
Location’ attribute in the FDT.
If and only if element E2
‘Transport’ is instantiated,
SHALL this attribute be
instantiated.
validFrom
A
NM/
0 . . . 1
The first moment of time this
unsignedInt
TM
group of Service Guide
fragments is valid. This field
contains the 32bits integer part
of an NTP time stamp.
Note: If this attribute is not
present, ‘validFrom’ attribute
MUST be present in the
‘Fragment’ sub-element.
validTo
A
NM/
0 . . . 1
The last moment of time this
unsignedInt
TM
group of Service Guide
fragments is valid. This field
contains the 32bits integer part
of an NTP time stamp.
Note: If this attribute is not
present, ‘validTo’ attribute
MUST be present in the
‘Fragment’ sub-element.
Fragment
E4
NM/
1 . . . N
Declaration of Service Guide
TM
fragment. If the fragment is
available over the broadcast
channel it MUST be present
here. If the fragment is
available over the interaction
channel it MAY be present
here.
Contains the following
attributes:
transportID,
id
version
validFrom
validTo
fragmentEncoding
fragmentType
Contains the following
element:
GroupingCriteria
transportID
A
NM/
0 . . . 1
The identifier of the announced
unsignedInt
TM
Service Guide fragment to be
used in the Service Guide
Delivery Unit header.
Note: if the SG is delivered
over the broadcast channel
only, this element MUST be
present
id
A
NM/
1
The identifier of the announced
anyURI
TM
Service Guide fragment.
version
A
NM/
1
The version of the announced
unsignedInt
TM
Service Guide fragment.
Note: The scope of the version
is limited to the given transport
session. The value of version
turn over from 2=− 1 to 0.
validFrom
A
NM/
0 . . . 1
The first moment when this
unsignedInt
TM
fragment is valid. If not given,
the validity is assumed to have
started at some time in the past.
This field contains the 32bits
integer part of an NTP time
stamp.
Note: If this attribute is present
and ‘validFrom’ attribute of
‘ServiceGuideDeliveryUnit’ is
also present, the value of this
attribute overrides the value of
‘ServiceGuideDeliveryUnit’
attribute ‘validFrom’.
validTo
A
NM/
0 . . . 1
The last moment when this
unsignedInt
TM
fragment is valid. If not given,
the validity is assumed to end
in undefined time in the future.
This field contains the 32bits
integer part of an NTP time
stamp.
Note: If this attribute is present
and ‘validTo’ attribute of
‘ServiceGuideDeliveryUnit’ is
also present, the value of this
attribute overrides the value of
‘ServiceGuideDeliveryUnit’
attribute ‘validTo’.
fragmentEncoding
A
NM/TM
1
Signals the encoding of a
unsignedByte
Service Guide fragment, with
the following values:
0 - XML encoded OMA
BCAST Service Guide
fragment
1 - SDP fragment
2 - MBMS User Service
Description as specified in
[26.346] (see 5.1.2.4,
SessionDescriptionReference)
3 - XML encoded Associated
Delivery Procedure as
specified in [BCAST10-
Distribution] section 5.3.4.
4-127 - reserved for future
BCAST extensions
128-255 - available for
proprietary extensions
fragmentType
A
NM/TM
0 . . . 1
This field signals the type of an
unsignedByte
XML encoded BCAST Service
Guide fragment, with the
following values:
0 - unspecified
1 - ‘Service’ Fragment
2 - ‘Content’ fragment
3 - ‘Schedule’ Fragment
4 - ‘Access’ Fragment
5 - ‘PurchaseItem’ Fragment
6 - ‘PurchaseData’ Fragment
7 - ‘PurchaseChannel’
Fragment
8 - ‘PreviewData’ Fragment
9 - ‘InteractivityData’
Fragment
10-127 - reserved for BCAST
extensions
128-255 - available for
proprietary extensions
This attribute SHALL be
present in case
‘fragmentEncoding’ = 0.
Default: 0
PreviewDataReference
E1
NM/
0 . . . N
Reference to the ‘PreviewData’
TM
fragment which specifies the
preview data (e.g. picture,
video clip, or low-bit rate
stream) associated with this
access.
It is possible that there are
more than one
PreviewDataReference
instances associated with the
same fragment, in which case,
the values of “usage” attributes
of these PreviewDataReference
instances SHALL be different.
Contains the following
attributes:
idRef
usage
idRef
A
NM/
1
Identification of the
anyURI
TM
‘PreviewData’ fragment which
this fragment associated with.
usage
A
NM/
1
Specifies the usage of the
unsignedByte
TM
associated preview data.
Possible values:
0. unspecified
1. Service-by-Service
Switching
2. Service Guide Browsing
3. Service Preview
4. Barker
5. Alternative to blackout
6-127. reserved for future use
128-255. reserved for
proprietary use
The explanation and limitation
on the above preview data
usages is specified in section
5.7.
Notification
E1
NM/
0 . . . 1
Reception information for
Reception
TM
service-specific Notification
Messages.
In case of delivery over
Broadcast
channel, ‘IPBroadcastDelivery’
specifies the address
information for receiving
Notification message.
In case of delivery over
Interaction channel,
‘RequestURL’ specifies
address information for
subscribing notification,
‘PollURL’ specifies address
information for polling
notification.
If this element is present, at
least one of the elements
“IPBroadcastDelivery”,
“RequestURL”, or “PollURL”
SHALL be present.
Contains the following
elements:
IPBroadcastDelivery
RequestURL
PollURL
IPBroadcast
E2
NM/TM
0 . . . 1
Provides IP multicast address
Delivery
and port number for reception
of Notification Messages over
the broadcast channel.
The ‘port’ is MANDATORY
in both Network and Terminal
because a designated UDP Port
has to be used to deliver the
Notification Message through
an on-going session or the
designated session while the
‘address’ is OPTIONAL to be
used for the delivery of
Notification Messages through
the designated multicast or
broadcast session.
In case the ‘address’ attribute
is not provided the destination
address provided by this access
fragment SHALL be assumed.
Contains the following
attributes:
port
address
port
A
NM/
1
Service-specific Notification
unsignedInt
TM
Message delivery UDP
destination port number,
delivery over broadcast
channel.
address
A
NM/
0 . . . 1
Service-specific Notification
string
TM
Message delivery IP multicast
address, delivery over
broadcast channel.
RequestURL
E2
NM/
0 . . . 1
URL through which the
anyURI
TM
terminal can subscribe to
service-specific Notification
Messages.
PollURL
E2
NM/
0 . . . 1
URL through which the
anyURI
TM
terminal can poll service-
specific Notification Messages.
PrivateExt
E1
NO/
0 . . . 1
An element serving as a
TO
container for proprietary or
application-specific extensions.
<proprietary
E2
NO/TO
0 . . . N
Proprietary or application-
elements>
specific elements that are not
defined in this specification.
These elements may further
contain sub-elements or
attributes.
In step 411, the terminal receives the stand-alone SG or the complementary SG, forms the SG, and displays it to the user.
In relation to the present invention, ‘BSMSelector’, ‘ServiceIDRef’, and ‘ServiceGuideDeliveryUnit’ are defined as sub-elements of ReferredSGInfo in Table 7. Other preliminary information about the stand-alone SG or the complementary SG can be additionally provided by use of the sub-elements of ReferredSGInfo.
The uses of the sub-elements of ReferredSGInfo will be described below.
The sub-element BSMSelector specifies the service provider that provides the stand-alone SG or the complementary SG. The service provider can be identified by an IDentifier (ID) of a BSMSelector by idREF or another name that the user can identify. In the former case, the terminal checks a BSMList defined in the SGDD used for receiving the basic SG, searches for BSMSelector information matching to the idRef in the BSMList, and acquires information such as a BSM code corresponding to the service provider or a service provider name that the user can identify. After receiving the stand-alone SG or the complementary SG, the terminal can classify and manage the SG on a code or a service provider name basis using the information. Or the basic SG may provide the information to the user so that the user can selectively receive an SG. This information can be provided in the form of a user-identifiable name directly to the user by ‘SPName’ as well as in the form of an ID by idRef.
The sub-element ServiceIDRef indicates a service associated with the stand-alone SG or the complementary SG within the basic SG. ServiceIDRef includes an ID identifying a Service fragment corresponding to the service. Therefore, when ServiceIDRef includes an ID, the terminal detects a Service fragment that matches the ID in the basic SG and is aware that the stand-alone SG or the complementary SG to be received is associated with the detected Service fragment.
The sub-element ServiceGuideDeliveryUnit indicates SGDUs associated with the stand-alone SG or the complementary SG in a delivery session that the Access fragment indicates. The service provider provides the basic SG and the stand-alone SG or the complementary SG in the same delivery session by providing an SGDU list, so that SGs can be received, classified and managed according to the SGDU list.
FIG. 7 is a block diagram of a BCAST network system for providing a BCAST service and a BCAST terminal according to an exemplary embodiment of the present invention.
Referring to FIG. 7 , a BCAST network system 710 can include the entities of the content creator 101 , the BCAST service application 104 , the BCAST service distributor/adapter 108 , and the BSCAST subscription manager 113 illustrated in FIG. 1 . In relation to an SG, the BCAST network system 710 includes an SG source generator 711 , an SG generator 712 and an SG transmitter 713 .
The SG source generator 711 can include the entities of the SGCCS 102 , the SGAS 105 , and the SGSS 114 illustrated in FIG. 1 and provides basic information about services and programs with which to generate an SG.
The SG generator 712 receives the SG generation information from the SG source generator 711 and generates an SG using the SG generation information. The SG generator 712 may include the entities of the SG-G 109 and the SG-A 111 illustrated in FIG. 1 . The SG generator 712 also generates SG fragments and defines cross-references between the fragments. Especially, the SG generator 712 defines cross-references between fragments for a basic SG, a stand-alone SG, and a complementary SG according to an exemplary embodiment of the present invention.
The SG transmitter 713 may include the entity of the SG-D 110 . The SG transmitter 713 is responsible for transmitting the SG generated from the SG generator 712 . In particular, the SG transmitter 713 forms delivery sessions to carry the basic SG and the stand-alone to complementary SG for the fragments generated by the SG generator 712 and transmits the fragments in the delivery sessions in the exemplary embodiment of the present invention.
A BDS 720 is a system that provides broadcast channels, including a broadcast transmission system 721 that can be DVB-H, 3GPP MBMS, 3GPP2 BCMCS and the like.
A BCAST terminal 730 corresponds to the terminal 119 of FIG. 1 . In accordance with an exemplary embodiment of the present invention, the BCAST terminal 730 receives, interprets and displays an SG. The BCAST terminal 730 may include a broadcast data receiver 731 for receiving broadcast data, an SG receiver 732 for receiving an SG, an SG interpreter 733 for interpreting the SG, and an SG display 734 for displaying the SG on a display 735 .
The SG receiver 732 , the SG interpreter 733 , and the SG display 734 perform the functions of the SG-C 120 illustrated in FIG. 1 . More specifically, the SG receiver 732 receives the basic SG, the SG interpreter 733 interprets fragments of the basic SG and the SG display 734 displays the interpretation result on the display 735 for the user in the exemplary embodiment of the present invention. When the user selects an intended service, the BCAST terminal 730 acquires information about the selected service by checking an associated Access fragment in the basic SG, receiving the Access fragment through the broadcast data receiver 731 and the SG receiver 732 , and interpreting it through the SG interpreter 733 . Then the BCAST terminal 730 displays the acquired information on the display 735 .
As is apparent from the above description, the present invention provides another SG through a basic SG. As a large SG can be distributed separately as a basic SG and a complementary SG to the basic SG or a stand-alone SG, SG transmission is more efficient. Earlier transmission of the basic SG than others saves SG reception time and provides information to users more rapidly.
While the invention has been shown and described with reference to certain exemplary embodiments thereof, it will be understood by those skilled in the art that various changes in form and details may be made therein without departing from the spirit and scope of the present invention as defined by the appended claims and their equivalents.
|
A method and apparatus for providing an SG in a mobile broadcasting system are provided. The apparatus and method include a terminal for receiving a first SG, for acquiring reception information about a second SG from the first SG, if a service fragment list extracted from the first SG includes information about at least one second SG different from the first SG, and for receiving the second SG based on the acquired reception information.
| 7
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BACKGROUND OF THE INVENTION
[0001] 1. Field of the Invention
[0002] The present invention relates generally to educational devices and methods. More specifically, the present invention relates to a motor and cognitive skills development program that includes a series of exercise mats having various instructional patterns thereon in increasing degrees or levels of physical and mental difficulty from very basic to more advanced moves and instructions.
[0003] 2. Description of the Related Art
[0004] The teaching of very basic physical and cognitive skills and knowledge to very young children and toddlers can be a difficult undertaking. The same is true of many other groups, e.g., persons suffering from autism or in need of special education or rehabilitation, etc. Explaining various jump activities, i.e., forward, backward, lateral, either or both feet, etc., may not be particularly difficult when communicating with a person having a reasonably good understanding of spoken instructions, or a person who is able to read and understand basic instructions. However, very young children or toddlers do not enjoy such a command of the language, and/or numbers and other symbols, for that matter. The same is true of children who speak and understand a different language from that of the instructor.
[0005] As a result, a number of different techniques have been employed to teach large muscle motor development skills, i.e., physical coordination, etc. These techniques generally rely upon individual markers, e.g., beanbags, variously shaped and colored cutouts or panels, hoops or rings, etc., with the teacher instructing the students to jump to, on, or into a given article. However, even if the student recognizes the command and can carry it out to some degree, the physical act of jumping or moving to the desired article tends to displace the article from its original location. Thus, not every student has the same task to perform at each turn. Moreover, instructions to perform more advanced maneuvers, e.g., jump to the side, jump using one foot, etc., may be more difficult for the instructor to convey verbally, and very young students or persons not familiar with the instructor's language will have some difficulty in understanding the wishes of the instructor.
[0006] Thus, a motor and cognitive skills development system solving the aforementioned problems is desired.
SUMMARY OF THE INVENTION
[0007] The motor and cognitive skills development system includes a series of exercise mats having instructions for performing a series of exercises thereon, with the instructions having increasing degrees of physical and/or mental difficulty. Each of the mats comprises a soft, cushioned sheet of material having non-slip lower and upper surfaces. The upper surfaces are each provided with instructions designating certain physical exercises, e.g., various jumps, etc., with those instructions being presented in various ways. For example, a very basic mat may have a series of positions thereon, each indicated by a representation of one or more feet. The foot representations may all be aligned longitudinally along the mat, indicating that the student is to jump straight ahead along the length of the mat, proceeding progressively from one position to the next. Different colors may be provided to combine the learning of basic mental skills or knowledge with the large muscle motor development produced by the physical jumping exercise. More advanced mats may include representations of various articles, e.g., automobile, boat, train, airplane, etc., and/or alphanumeric indicators, thus developing higher levels of mental learning, with other mats having more intricate exercise indicators, e.g., a single foot, jumping to and from various positions, turning while jumping, etc.
[0008] The physical and cognitive degrees of difficulty provided by the various mats of the series may be combined in different ways, depending upon the needs of the student and the curriculum used. For example, relatively simple visual instructions, such as foot position representations, may be combined with relatively intricate footwork requirements to complete a given exercise. More advanced indications, e.g., alphanumeric symbols, may be used with relatively simple and straightforward physical exercises, depending upon the needs of the student. In any case, the physical and/or mental challenges increase with successive mats in order to continue to challenge the student. Additional physical challenge may be provided in the form of raised barriers between different jump positions, or raised positions, on one or more of the mats. Optionally, the raised barriers or positions may be temporarily installable and removable.
[0009] These and other features of the present invention will become readily apparent upon further review of the following specification and drawings.
BRIEF DESCRIPTION OF THE DRAWINGS
[0010] FIG. 1 is an environmental, perspective view of an exemplary mat of the motor and cognitive skills development system according to the present invention, showing its use.
[0011] FIG. 2 is a top plan view of an exemplary basic mat of the system, incorporating pictorial and numerical designations for the jump positions.
[0012] FIG. 3 is a top plan view of another exemplary mat in the system, requiring lateral jumps and incorporating pictorial and alphabetic designations for the jump positions.
[0013] FIG. 4 is a top plan view of another exemplary mat in the system, requiring turning jumps and using pictorial designations.
[0014] FIG. 5 is a top plan view of another exemplary mat in the system, requiring turning jumps and using pictorial representations on the jump positions.
[0015] FIG. 6 is a top plan view of an exemplary more advanced mat in the system, requiring turning and alternating straddle jumps, and using pictorial representations.
[0016] FIG. 7 is a top plan view of another exemplary mat in the system requiring jumps to different positions, with the positions indicated by a sequential numerical series.
[0017] FIG. 8 is a top plan view of another exemplary mat in the system, requiring a frog jump, with the jump postures indicated by a frog caricature in each position.
[0018] FIG. 9 is a top plan view of another exemplary mat in the system, requiring a straddle jump, with the jump postures indicated by an animal caricature in each position.
[0019] FIG. 10 is a top plan view of another exemplary mat in the system, requiring a tuck jump, with the jump postures indicated by an animal caricature in each position.
[0020] FIG. 11 is a top plan view of another exemplary mat in the system, requiring a pike jump, with the jump postures indicated by an animal caricature in each position.
[0021] FIG. 12 is an exploded perspective view of an exemplary relatively basic mat in the system having detachable barriers between positions.
[0022] FIG. 13 is a perspective view of another exemplary mat in the system, requiring alternating straddle jumps and having a removable raised central area.
[0023] FIG. 14 is a perspective view of another exemplary mat in the system, requiring squat and straddle jumps and having a removable raised forward area.
[0024] Similar reference characters denote corresponding features consistently throughout the attached drawings.
DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS
[0025] The present invention relates to a motor and cognitive skills development system and method that includes a series of exercise mats having instructions thereon indicating different levels of exercise and cognitive difficulty for the student. The mats form the motor and cognitive skills development system, particularly when used by an instructor with an appropriate syllabus for the program. The mats are preferably used in increasing or ascending order of motor and/or cognitive skill difficulty.
[0026] FIG. 1 of the drawings is an environmental perspective view showing the use of an exemplary exercise mat 100 . The exercise mat 100 , and others in the series forming the system, has an upper surface 102 , an opposite lower surface 104 defining a thickness 106 therebetween, and a periphery 108 . Both the upper and lower surfaces 102 and 104 are preferably formed of a non-skid material, i.e., a material having a reasonably high coefficient of friction in order to reduce slippage of the mat upon the underlying surface during use and slippage of a person using the mat. The various exercise mats, e.g., the mat 100 of FIG. 1 , are preferably formed of a reasonably resilient closed cell foam material in order to cushion the landing impact of the user, but any other practicable materials may be used to construct the mats as desired.
[0027] The upper surface 102 of the exercise mat 100 is divided into a series of exercise positions ranging from an initial exercise position 110 a through a final exercise position 110 c. Each of the positions 110 a through 110 c includes indicia, respectively 112 a through 112 c , forming an exercise instruction disposed upon the upper surface of the mat. In the exemplary mat 100 of FIG. 1 , the indicia 112 a through 112 c comprise a series of representations of foot positions indicating or depicting the desired corresponding foot positions for a student progressing along the exercise positions 110 a through 110 c of the mat 100 . The mat 100 depicts a series of relatively simple jumps, beginning with a single generic foot position or representation (i.e., not specifically representing either the left or right foot) centered in the first exercise position 110 a for the initial exercise instruction 112 a , continuing to a pair of foot representations comprising a left foot and a right foot for the next exercise instruction 112 b , and ending with a single generic foot representation for the final exercise instruction 112 c , centered in the final exercise position 110 c.
[0028] It will be noted that the exercise instructions 112 a through 112 c of the mat 100 of FIG. 1 do not require the student to be able to recognize alphanumeric characters, printed instructions, or even colors, as all of the foot representations, positions or exercise instructions 112 a through 112 c are the same color in the exemplary mat 100 of FIG. 1 . All the student need do is to recognize the shapes and orientations of the foot symbol exercise instructions 112 a through 112 c and understand that those symbols indicate the desired exercise activity, i.e., standing on the first instruction symbol 112 a with either foot as instructed or as desired, jumping to the intermediate foot representations 112 b with one foot landing on each foot symbol, and finally jumping to the last foot position or exercise instruction 112 c to land thereon with either foot, as instructed or as desired. It should be noted that in many cases a student will begin with an exercise mat depicting even simpler or more basic jumps that do not require the student to balance upon one foot at any time. The exercise mat 100 of FIG. 1 is exemplary, and may not necessarily be used to introduce a student to the concepts of the system.
[0029] FIG. 2 is a top plan view of a basic exercise mat 200 that might be used to introduce students to the concepts of the present invention. The exercise mat 200 might be used as an introduction to the skills development system of the present invention, as it requires a series of only very simple, basic jumps. The mat 200 is constructed or formed similarly to the mat 100 of FIG. 1 , i.e., having non-skid or slip resistant upper and lower surfaces with a resilient core material therebetween and a series of exercise positions 210 a through 210 d displayed on the upper surface 202 . The exercise positions 210 a through 210 d are shown by circles on the mat 200 , as well as by rectangular areas defined by a series of lateral lines, as in the mat 100 of FIG. 1 . Each of the exercise positions 210 a through 210 d includes an exercise instruction comprising a representation of a foot position thereon, or more accurately, respective foot pair position indicia 212 a through 212 d . It will be noted that these foot configuration exercise instructions 212 a through 212 d are all oriented in the same direction and, thus, require the student or user to make a short jump straight ahead to each successive exercise position and foot pattern instruction or position. The exercise mat 200 requires only very simple, basic muscular coordination on the part of the student or user, with relatively low demand in the manner of balance and no requirement for turning or changing the foot pattern or spacing in mid-jump.
[0030] However, it will be noted that each of the foot patterns, or exercise instructions 212 a through 212 d include indicia depicting a numeral thereon, respectively 214 a through 214 d , with each of the foot pattern exercise instructions being colored differently from one another. In the exemplary basic mat 200 of FIG. 2 , the first foot position exercise instruction 212 a is colored green and includes the number one thereon, the second foot position exercise instruction 212 b is colored yellow and includes the number two thereon, the third foot position exercise instruction 212 c is colored red and includes the number three thereon, and the fourth foot position exercise instruction 212 d is colored blue and includes the number four thereon. (These colors are exemplary, and any colors as desired may be applied to the foot position exercise instructions 212 a through 212 d .) In this manner, a student who is incapable of recognizing the basic cardinal numerals may be instructed by referring to the instruction positions 212 a through 212 d by their colors, as depicted upon each of those positions. Students having more advanced cognitive skills, i.e., who are capable of recognizing the basic cardinal numbers, may be directed by referring to those numbers 214 a through 214 d upon each of the respective exercise instruction positions 212 a through 212 d.
[0031] FIG. 3 is a top plan view of an exemplary exercise mat 300 depicting a jump exercise of slightly greater difficulty than that depicted by the exercise mat 200 of FIG. 2 . The mat 300 is configured at least generally like the mat 200 of FIG. 2 , i.e., having non-skid opposed upper and lower surfaces 302 and 304 defining a thickness for the resilient core material and a series of exercise positions, in this case five such positions 310 a through 310 e , thereon. The positions 310 a through 310 e are defined by circles on the mat 300 , as in the case of the circular positions 210 a through 210 d of the mat 200 of FIG. 2 . Each of the exercise positions includes an exercise instruction therein, i.e., a instruction of the position to be taken by the student or user of the mat 300 on each of the instructions. As in the case of the mats 100 and 200 of FIGS. 1 and 2 , the exercise instructions 312 a through 312 e are marked by a series of foot symbols. Those foot symbol exercise instructions 312 a through 312 e are colored differently from one another in order to permit a student having no knowledge of the alphabet to negotiate the mat 300 successfully. In the exemplary mat 300 of FIG. 3 , the foot symbol exercise instructions 312 a through 312 e are respectively colored blue, red, yellow, green, and purple, although other colors or patterns, e.g., stripes, polka-dots, etc. may be used.
[0032] However, the mat 300 differs from the basic mat 200 in that it requires somewhat greater motor or muscular skills than does the mat 200 . It will be noted that each of the exercise instructions 312 a through 312 e is designated by a pair of foot symbols, with those foot symbols oriented laterally relative to the length of the mat. This indicates that the user of the mat 300 must jump laterally from the first exercise instruction 312 a to the next 312 b , and so forth until reaching the last exercise instruction 312 e . This results in a somewhat greater challenge for the student or user, in that jumping laterally is somewhat more difficult than a relatively simple forward jump.
[0033] It will be noted that rather than using numerical designators for the various exercise positions, the mat 300 utilizes a series of alphabetic symbols 316 a through 316 e . This requires perhaps a slightly greater level of cognitive skill or ability on the part of the user or student, as the student must have some knowledge of at least the initial order of the alphabet in order to successfully complete the lateral jumping exercises of the mat 300 when instructed by reference to the alphabetic characters 316 a through 316 e thereon. Thus, the mat 300 represents a requirement of at least a slightly higher level of motor and cognitive skill than does the basic mat 200 . Normally, an instructor would initiate the present system by using the basic mat 200 , and advance to the next level of mat 300 when students or users were judged to be sufficiently capable.
[0034] The exercise mat 400 of FIG. 4 is configured at least generally like the mats 200 of FIG. 2 and 300 of FIG. 3 , i.e., having non-skid opposed upper and lower surfaces 402 and 404 defining a thickness for the resilient core material and a series of exercise positions, in this case five such positions 410 a through 410 e , thereon. The positions 410 a through 410 e are defined by circles on the mat 400 , as in the case of the circular positions 210 a through 210 d of the mat 200 of FIG. 2 and 310 a through 310 e of the mat 300 of FIG. 3 . Each of the exercise positions includes an exercise instruction therein, i.e., a representation of the position to be taken by the student or user of the mat 400 on each of the instructions. As in the case of the mats 100 through 300 of FIGS. 1 through 3 , the exercise instructions 412 a through 412 e are marked by a series of foot symbols. Those foot symbol exercise instructions 412 a through 412 e are colored differently from one another in order to permit a student having no knowledge of the alphabet to negotiate the mat 400 successfully. In the exemplary mat 400 of FIG. 4 , the foot symbol exercise instructions 412 a through 412 e are respectively colored yellow, green, red, blue, and purple, although other colors or patterns, e.g., stripes, polka-dots, etc. may be used as desired.
[0035] However, the mat 400 differs from the basic mat 200 and higher level mat 300 in that it requires somewhat greater motor or muscular skills than do the mats 200 and 300 . It will be noted that each of the exercise instructions 412 a through 412 e is designated by a pair of foot symbols, with those foot symbols turned 90 degrees clockwise with each succeeding position. This indicates that the user of the mat 400 must turn clockwise 90 degrees during the midpoint of each jump from one position to the next. This results in a somewhat greater challenge for the student or user than provided by the mat 300 of FIG. 3 , in that turning in mid-air while jumping is somewhat more difficult than jumping laterally without turning.
[0036] It will be noted that the mat 400 of FIG. 4 does not include any numerical or alphabetic indicators or symbols, as do the mats 200 and 300 . The mat 400 might be used in teaching or training slightly older or more advanced students who are capable of the more advanced motor skills required, but for some reason have not yet developed the cognitive skills required for recognition of numerical or alphabetic characters. Alternatively, the mat 400 could be provided with such characters or symbols, or others (e.g., Roman numerals, etc.), if so desired in order to require more advanced cognitive skills for the mat 400 .
[0037] FIG. 5 is a top plan view of an exemplary exercise mat 500 depicting a jump exercise of slightly greater difficulty than that depicted by the exercise mat 400 of FIG. 4 . The mat 500 is configured at least generally like the mats 200 through 400 of FIGS. 2 through 4 , i.e., having non-skid opposed upper and lower surfaces 502 and 504 defining a thickness for the resilient core material and a series of exercise positions, in this case five such positions 510 a through 510 e , thereon. The positions 510 a through 510 e are defined by circles on the mat 500 , as in the case of the circular positions 210 a through 210 d of the mat 200 of FIG. 2 and others. Alternative non-circular shapes may be used for the exercise positions of the mat 500 and other mats, if so desired. Each of the exercise positions includes an exercise instruction therein, i.e., a representation of the position to be taken by the student or user of the mat 500 on each of the instructions. As in the case of the mats 100 through 400 of FIGS. 1 through 4 , the exercise instructions 512 a through 512 e are marked by a series of foot symbol exercise instructions 512 a through 512 e . All of the foot symbol exercise instructions 512 a through 512 e of the mat 500 are colored identically to one another in this example, e.g., blue, for reasons explained further below.
[0038] As in the case of the mats 200 through 400 of FIGS. 2 through 4 , the mat 500 requires a somewhat higher level of motor or muscular skills, as it represents the next step in the exercise mat series of the skills development system of the present invention. It will be noted that each of the exercise instructions 512 a through 512 e is designated by a pair of foot symbols, with those foot symbols turned 180 degrees or reversed relative to one another with each succeeding position. This indicates that the user of the mat 500 must turn 180 degrees during the midpoint of each jump from one position to the next. This results in a somewhat greater challenge for the student or user than provided by the mat 400 of FIG. 3 , in that reversing direction in mid-air while turning is somewhat more difficult than turning only 90 degrees while jumping.
[0039] It will be noted that rather than using numerical or alphabetic designators for the various exercise positions, the mat 500 utilizes a series of pictorial symbols or representations of objects 518 a through 518 e. This requires perhaps a slightly greater level of cognitive skill or ability on the part of the user or student, as the student must be able to recognize the objects, and perhaps the class of objects, in order to successfully complete the lateral jumping exercises of the mat 500 when instructed by reference to the symbols or representations 516 a through 516 e thereon. Thus, the mat 500 represents another step up the level of motor and cognitive skill required than does the previous mat 400 . In the example of the mat 500 of FIG. 5 , the symbols 518 a through 518 e respectively represent an apple, a pear (or perhaps an avocado), an orange, a bunch of grapes, and a banana, and are correspondingly colored red, green, orange, purple, and yellow. As the symbols or representations 518 a through 518 e are colored differently from one another, there is no need to provide different colors for each of the foot symbol exercise representations or instructions 512 a through 512 e on the mat 500 , and they may all be the same color, e.g., blue, or at least a different color from that used for any of the symbols 518 a through 518 e . Alternatively, other symbols may be used, e.g., different geometric or polygonal shapes, different animal species, etc., as desired.
[0040] The exercise mat 600 of FIG. 6 represents yet another step or advance in the degree of difficulty of the exercises represented, over the mat 500 of FIG. 5 . The exercise mat 600 of FIG. 6 is configured at least generally like the mats 200 through 500 respectively of FIGS. 2 through 5 , i.e., having non-skid opposed upper and lower surfaces 602 and 604 defining a thickness for the resilient core material and a series of exercise positions, in this case nine such positions 610 a through 610 i , thereon. Each of the exercise positions includes a corresponding exercise instruction therein, i.e., an instruction of the position to be taken by the student or user of the mat 600 on each of the instructions. These exercise instructions are designated as foot position symbols or instructions 612 a through 612 i on the mat 600 of FIG. 6 .
[0041] The jumping exercises required by the mat 600 are somewhat more advanced than those required by the mats 200 through 500 . It will be noted that two laterally offset longitudinal lines 620 a and 620 b are placed on the upper surface 602 of the mat 600 , with positions 610 a , 610 c , 610 e , 610 g , and 610 i disposed to the outside of these lines and alternating positions 610 b , 610 d , 610 f , and 610 h positioned between the lines. This requires the student or user to initiate the exercise with his or her feet widely spread and positioned upon the two foot symbols 612 a of the initial position 610 a . The student then jumps to the second position 610 b while drawing his or her feet close together and turning 180° in mid-jump, as the two foot symbol instructions 612 b are close to one another within the two lines 620 a and 620 b and reversed in their orientation relative to the initial foot position symbol instructions 612 a.
[0042] It will be noted that the next position, i.e., foot position instructions 612 c , are again widely spread, and are also reversed by 180° relative to the initial position instructions 612 a . This requires the student or user of the mat 600 to jump backwards from the position 610 b and spread his or her feet to land upon the foot symbol instructions 612 c . It will be seen that this is a somewhat more difficult exercise than that represented on the exercise mat 500 of FIG. 5 , which only required the student or user to turn 180° with each lateral jump, rather than alternately spreading the feet and drawing them closer together. The student continues to make the jumps as indicated by the exercise mat 600 of FIG. 6 , by alternately spreading the feet to straddle the two lines 620 a and 620 b and drawing the feet together for the next jump, and turning 180° with each jump to one of the center positions 610 b , 610 d , 610 f , or 610 h.
[0043] While the jumping exercises required of the mat 600 are somewhat more advanced than those of the previous mat 500 , it will be noted that the only differentiation between the different exercise instruction symbols 612 a through 612 i is by color. In the case of the exercise mat 600 , the first foot instruction positions 612 a are green with each two subsequent instruction positions sharing the same color, e.g., instruction positions 612 b and 612 c are red, instruction positions 612 d and 612 e are blue, etc. As in the case of the color differentiated instruction positions of the mat 400 , the mat 600 might be used in teaching or training slightly older or more advanced students who are capable of the more advanced motor skills required, but for some reason have not yet developed the cognitive skills required for recognition of numerical or alphabetic characters. Alternatively, the mat 600 could be provided with such characters or symbols, or others (e.g., Roman numerals, etc.), if so desired in order to require more advanced cognitive skills for the mat 600 .
[0044] FIG. 7 provides a top plan view of yet another alternative mat configuration, designated as exercise mat 700 . The mat 700 includes an upper surface 702 and opposite lower surface 704 defining a thickness therebetween, as in the cases of the other mats 100 through 600 described further above. However, rather than having an elongate configuration and requiring the jumps to be made in a generally linear path, the mat 700 is square and contains a series of exercise positions 710 a through 710 h arranged in an evenly spaced array thereon. Four of the eight positions are contained within an inner border 722 , e.g., a circle disposed upon the upper surface 702 , with the remaining four positions being placed outside the circle.
[0045] It will be noted that the exercise mat 700 does not include any foot symbol instructions thereon, but rather uses somewhat more abstract position markers for the positions 710 a through 710 h . Some of the position markers are in the form of simple circles, while others are in the form of stars. The specific shape or configuration is not critical. It will also be noted that the various markers or positions 710 a through 710 h are variously colored, similarly to the different colors used to designate the various positions of the mats of FIGS. 2 through 6 . However, additional challenge is provided by the numerals 714 a through 714 h placed upon the corresponding positions 710 a through 710 h . It will be noted that while the numbers 714 a through 714 h are in consecutive order, only odd numbers 714 a , 714 c , 714 e , and 714 g are located within the circular border 722 , with only even numbers 714 b , 714 d , 714 f , and 714 h being located outside the border 722 .
[0046] The provision of different shapes for the positions, the inclusion of some of the positions within a separate zone or border, and the use of a series of consecutive numbers to designate the various positions, provides a series of different alternatives for the instructor and student. For example, the instructor may instruct a student who cannot read the numbers to “jump from the red circle to the yellow star,” i.e., positions 710 a and 710 b designated by the cardinal numerals one and two. Students who know the cardinal numerals may be instructed by reference to those numerals, and may be required to perform a somewhat more advanced exercise by turning to orient themselves with the orientation of the number of the position to which they are jumping. It should be noted that the numbers may be replaced by various other symbols, e.g., mathematical symbols, tools or implements, letters of the alphabet, etc., as desired. It should also be noted that as there is no indication of a specific pattern or orientation for either or both feet, the instructor may ask more advanced students to jump using a single foot with the exercise mat 700 . Thus, the mat 700 of FIG. 7 represents somewhat more challenge for both motor and cognitive skills, than do the other mats previously discussed to this point.
[0047] FIGS. 8 and 9 provide illustrations of mats 800 and 900 , each having a caricature thereon to indicate the desired jumping exercise. The exercise mats 800 and 900 are constructed similarly to the mats previously discussed, i.e., having upper and lower surfaces 802 , 804 and 902 , 904 defining thicknesses therebetween, with the upper surfaces 802 and 902 having representations of jumping exercises thereon. The exercise mat 802 includes three exercise positions 810 a through 810 c thereon, with each of the positions having an animal instructional caricature thereon, e.g., a frog, in the case of the mat 800 . While an instructional caricature of an animal known for its jumping ability may be preferred in order to associate with the jumping exercise, it is not an essential of the present system.
[0048] It will be noted that the caricature instructions 812 a through 812 c represent three different jump postures to be performed during the course of the jump exercise directed by the mat 800 . The first exercise representation or instruction 812 a shows the instructional caricature 812 a in a squatting position, as would be appropriate for a frog. The second instructional caricature 812 b shows the caricature in mid-jump, and fully extended. Finally, the third instructional caricature 812 c shows the caricature having completed the jump, and having returned to the squatting posture or position. While it may be possible for the exercising student to travel forward from the first position 810 a to the final position 810 c during the jump, this is not an absolute requirement when undertaking such a “squat-jump” from an initially squatting position or posture.
[0049] The exercise mat 900 of FIG. 9 is similar to the mat 800 of FIG. 8 , but illustrates the initial, mid-jump, and final positions for a “straddle jump,” as might be made using the exercise mat of FIG. 6 . As in the case of the caricature mat 800 of FIG. 8 , the mat 900 of FIG. 9 includes a series of three positions 910 a , 910 b , and 910 c , with a rabbit instructional caricature representing the corresponding three exercise postures 912 a , 912 b , and 912 c . From the initial exercise posture or instruction 912 a , the student jumps to spread the legs and feet apart during mid-jump as indicated by the intermediate instructional caricature 912 b . The final caricature instruction 912 c shows the instructional caricature with feet slightly spread and knees bent, while having turned nearly 90 degrees. This final posture may be varied by requiring the student to land with feet together and straight ahead, or in various final jump postures as desired.
[0050] FIGS. 10 and 11 provide illustrations of mats 1000 and 1100 , similar to the caricature exercise mats 800 and 900 respectively of FIGS. 8 and 9 but illustrating different jump styles. The exercise mats 1000 and 1100 are constructed similarly to the mats previously discussed, i.e., having upper and lower surfaces 1002 , 1004 and 1102 , 1104 defining thicknesses therebetween, with the upper surfaces 1002 and 1102 having representations of jumping exercises thereon. The exercise mat 1002 includes three exercise positions 1010 a through 1010 c thereon, with each of the positions having an animal instructional caricature thereon, e.g., a rabbit, in the case of the mat 1000 . Again, a caricature of an animal known for its jumping ability may be preferred in order to associate with the jumping exercise, but it is not an essential of the present system.
[0051] As in the cases of the mats 800 and 900 of FIGS. 8 and 9 , the caricature instructions 1012 a through 1012 c represent three different jump postures to be performed during the course of the jump exercise directed by the mat 1000 . The first exercise instruction or position 1012 a shows the instructional caricature 1012 a in an upright position with arms raised. The second instructional caricature 1012 b shows the caricature in mid-jump, with the legs pulled upwardly in a “tuck” position or posture. Finally, the third instructional caricature 1012 c shows the caricature having completed the jump, with the legs bent at the knees and hips in a semi-tuck position and arms extended horizontally. As in the cases of the exercise mats 800 and 900 of FIGS. 8 and 9 , it may be possible for the exercising student to travel forward from the first position 1010 a to the final position 1010 c during the jump. However, this is not an absolute requirement when undertaking such a “tuck-jump” from an initial standing position or posture.
[0052] The exercise mat 1100 of FIG. 11 is similar to the mats 800 through 1000 of FIGS. 8 through 10 , but illustrates the initial, mid-jump, and final positions for a “pike jump.” As in the case of the mats 800 through 1000 of FIGS. 8 through 10 , the mat 1100 of FIG. 11 includes a series of three positions 1110 a , 1110 b , and 1110 c , with a rabbit instructional caricature representing the corresponding three exercise postures 1112 a , 1112 b , and 1112 c . The initial exercise posture or instruction 1112 a is similar to that shown by the initial instruction 1012 a of the mat 1000 of FIG. 10 , i.e., upright with arms extended. However, the mid-jump posture shown by the instructional caricature 1112 b is somewhat different from the “tuck-jump” posture illustrated by the instructional caricature 1012 b of the mat 1000 of FIG. 10 . Rather than tucking the legs upwardly, the legs are extended at an angle from the hips, as illustrated by the instructional caricature 1112 b in FIG. 11 . Finally, the landing position 1112 c is accomplished with the legs bent at knees and hips and the arms extended horizontally, similarly to the final instruction 1012 c shown on the mat 1000 of FIG. 10 . Again, variations on these jumps and postures may be assigned according to the abilities of the students, but it will be seen that generally, the jumps illustrated in FIGS. 8 through 11 require some additional level of physical skill over those jumps shown on the mats 200 through 700 of FIGS. 2 through 7 . Additional challenge may be provided by requiring such mid-jump maneuvers as shown particularly in FIGS. 9 through 11 , with the various jump indications and instructions provided on the various other mats 100 through 700 .
[0053] FIGS. 12 through 14 illustrate alternative mat configurations wherein one or more raised partitions, portions, or levels may be installed thereon. The mat 1200 of FIG. 12 will be seen to be somewhat similar to the mat 100 of FIG. 1 , i.e., having an upper surface 1202 , an opposite lower surface 1204 defining a thickness 1206 therebetween, and a periphery 1208 . The mat 1200 is divided into a series of four exercise positions 1210 a through 1210 d . The mat 1200 depicts a series of relatively simple jumps, beginning with a single generic foot position or representation for the initial exercise instruction 1212 a , continuing to a pair of foot representations for the next exercise instruction 1212 b and then to another single generic foot position 1212 c , and ending with another pair of foot representations for the final exercise instruction 1212 d . The mat 1200 may include caricatures at various areas thereon, similar to the mat 500 of FIG. 5 . In the case of the mat 1200 , spider caricatures or representations 1218 b and 1218 d are positioned beneath the respective two-footed representations 1212 b and 1212 d as mnemonic devices to urge the student to jump with both feet on the foot positions 1212 b and 1212 d in order to “squash the spider.” Other caricatures, symbols, etc. may be used in lieu of the spider representations 1218 b and 1218 d , as desired.
[0054] The mat 1200 differs further from the mat 100 by having peripheral attach points 1224 for the attachment of the raised partitions or portions thereto. The raised mat portion attachments 1224 are preferably located at the dividing lines between the various exercise positions 1210 a through 1210 c , and provide for the attachment of corresponding relatively narrow transverse obstacles 1226 thereto. The obstacles 1226 are preferably formed of a relatively soft and resilient material such as that used to construct the mats 100 through 1200 , e.g., a closed cell foam material or other suitable material as desired. Each of the obstacles 1226 includes opposed peripheral end portions 1228 congruent with the corresponding portions of the periphery 1208 of the mat 1200 , with corresponding exercise mat attachments 1230 depending therefrom. The various obstacles 1226 are preferably removably attached across the underlying mat 1200 , with the raised mat portion attachments 1224 of the underlying mat and the corresponding exercise mat attachments 1230 of the obstacles comprising mating first and second hook and loop fabric fastener material, e.g., Velcro®. Other fastening means may be used as desired, e.g., snaps, buttons, etc., as desired, or the obstacles 1226 may be permanently attached to the underlying mat 1200 by stitching, etc. if so desired.
[0055] The mat 1200 equipped with the transverse obstacles 1226 adds a further challenge to the student using the device. The ability to install or remove the obstacles 1226 from the mat 1200 , or other mat equipped with appropriate attachment means such as the raised mat portion attachments 1224 , enables the instructor to increase the challenge by adding such obstacles thereacross as appropriate to the level of skill of the student without requiring a separate mat. The installation of the attachments along the periphery of the mat 1200 avoids the installation of such attachments to the upper surface 1202 of the mat, thereby providing an unbroken exercise surface for the student.
[0056] FIG. 13 illustrates a mat 1300 having a longitudinally disposed raised mat portion 1326 removably attached thereto. The mat 1300 is configured much like the mat 600 of FIG. 6 , i.e., having top and bottom surfaces 1302 , 1304 defining a thickness 1306 therebetween, a periphery 1308 , and a series of exercise positions 1310 a through 1310 d and laterally spread foot or other instructional representations 1312 a through 1312 d thereon. However, the exercise positions or instructions 1312 a through 1312 d of the mat 1300 are all oriented in the same direction, rather than being reversed at every other position as in the case of the mat 600 .
[0057] This would provide somewhat easier negotiation of the exercise assignment as represented by the mat 1300 , except for the longitudinally disposed raised mat portion 1326 extending down the longitudinal center of the mat 1300 between the spread positions 1310 a through 1310 d and exercise positions or instructions 1312 a through 1312 d . The addition of the raised central area or portion 1326 adds to the challenge of the jumping exercise task indicated by the mat 1300 . The raised portion 1326 includes a series of jump positions 1332 a through 1332 c thereon, with those positions including corresponding foot or other representations or instructional positions 1334 a through 1334 c thereon. Thus, the student or user of the mat 1300 would begin with his or her feet spread to rest upon the two exercise instructional positions 1312 a at the beginning of the mat, and jump to the first exercise instructional position 1334 a of the raised central portion 1326 . From the instructional position 1334 a , the student then straddle jumps to the second straddle instructional positions 1312 b of the primary mat 1300 , and so on until completing the exercise upon the final straddle instructional positions 1312 d at the end of the primary mat 1300 .
[0058] The raised central portion 1324 may be removably secured to the underlying mat 1300 in much the same manner as used for securing the transverse obstacles 1224 to the underlying mat 1200 of FIG. 12 , i.e., using a first fastening means attached to the periphery 1308 of the primary mat 1300 , with a second mating fastening means 1330 depending from the congruent end 1328 of the overlying raised portion 1326 . The first fastening means attached to the end periphery of the base mat 1300 is not shown in FIG. 13 due to the completed installation of the overlying raised mat portion 1326 , but will be understood to be essentially the same as that shown in FIG. 12 for the mat 1200 and its lateral obstacles 1226 , discussed further above. The concealed central longitudinal area of the mat 1300 may also include a series of exercise and foot positions thereon in a similar manner to the mat 600 of FIG. 6 if so desired, enabling the mat 1300 to be used for alternating straddle and feet-together jumps with or without the overlying raised central portion 1324 .
[0059] FIG. 14 illustrates a mat 1400 having yet another detachable raised mat portion therewith. The mat 1400 is configured much like the other mats of the present invention, i.e., having top and bottom surfaces 1402 , 1404 defining a thickness 1406 therebetween, a periphery 1408 , and at least an initial exercise position 1410 including a foot pair instructional representation 1412 therein. However, the mat 1400 is relatively short and is adapted for the removable attachment of a laterally disposed, raised lateral mat portion 1426 thereacross. The raised lateral portion 1426 attaches to the base mat 1400 in the same manner as used for the removable attachment of the raised portions of the mat embodiments 1200 and 1300 of FIGS. 12 and 13 , i.e., a flap of exercise mat attachment material 1430 depends from each of the congruent ends 1428 of the overlying raise portion 1426 , to attach removably to a corresponding overlay mat attach material (not shown in FIG. 14 , but similar to the components 1224 of the mat 1200 of FIG. 12 ) provided on the lateral periphery of the underlying base mat 1400 . In this manner, no break exists in the upper exercise surface 1402 of the underlying mat 1400 due to the attachment of some form of fastener means thereto, as in the case of the other mats 1200 and 1300 having detachable portions.
[0060] The detachable upper mat portion 1426 includes two sets or pairs of foot instructional positions 1434 a and 1434 b thereon, and a set or pair of hand instructional positions 1436 . This mat 1400 and 1426 combination thus requires the student to bend and squat to place the hands upon the two hand positions 1436 of the upper mat 1426 , while simultaneously placing the feet upon the initial instructional position 1412 on the base mat 1400 . The student then hops with the feet to jump to the first or center foot instructional position 1434 a , while keeping the hands on the two hand positions 1436 . (The feet markings of the upper center foot position 1434 a are relatively short, as normally the heels would be raised and only the forward portions of the feet would rest on the upper mat 1426 when the student has his or her hands placed upon the closely spaced hand instructional positions 1436 on the same level.) The exercise may comprise kicking back and forth between the central lower and raised foot instructional positions 1412 and 1434 a , i.e., “squat-on” or “straddle-on,” or perhaps a more advanced exercise in which the feet are spread during the jump to place the feet upon the outer instructional positions 1434 b.
[0061] As in the case of various other examples of the invention discussed further above, the various foot instructional positions 1412 , 1434 a , and/or 1434 b may be colored or otherwise marked to distinguish them from one another, if so desired. In the example of FIG. 14 , it will be noted that the central upper and lower foot instructional positions are colored blue, while the wider upper foot instructional positions are colored red. Thus, the instructor may instruct the student to “jump from the lower blue to the upper blue,” i.e., jump from the initial starting instructional position 1412 to the upper central instructional position 1434 a , or to “jump from the lower blue to the red,” i.e., to jump from the lower central initial starting position 1412 in a straddle jump to the more widely spread foot instructional positions 1434 b , a somewhat more difficult and advanced maneuver.
[0062] The various mats are used in keeping with the discussion of the various embodiments above, with the instructor or teacher selecting one or more mats in keeping with the physical and/or cognitive abilities or skill levels of the students and the syllabus, lesson plan, or other arrangement as desired. The selected mats are preferably arranged (physically or otherwise) in increasing order of physical and/or cognitive level of skill required to complete the various exercises designated on the mats. Thus, the instructor may select the mat 200 of FIG. 2 , the mat 400 of FIG. 4 , and the mat 600 of FIG. 6 , for example. These mats need not be placed in a linear array according to their level of difficulty, but may be placed in different areas as desired. The instructor can then assign the student or students to proceed to the selected mat and perform the jumping exercise(s) as designated by that mat.
[0063] In many cases, it will be found that a student is quite capable of completing the simplest jump exercises designated by the simpler mats of the series or system. In such cases, the instructor may have the student continue to a more advanced mat, if so desired. Alternatively, the instructor may improvise a greater level of difficulty for the student who has mastered the jumping exercise pattern of a given mat, e.g., performing the exercise backwards, jumping with only one leg and foot, etc. In any event, the instructor will normally begin with the simpler mat exercise patterns that are easier to master, and have the student(s) progress to more difficult jumping exercise patterns, e.g., straddle jumps, etc.
[0064] Alternatively, the instructor may assign the student or students to use the mats in accordance with a sequence of increasing levels of cognitive skill. This might be done by having the student(s) perform an initial jumping exercise using the mat 100 of FIG. 1 , where the student need only recognize the directional orientation of the foot instructional patterns and jump to place his or her feet accordingly. The next level of cognitive performance may be required by e.g., the mat 400 of FIG. 4 , wherein the foot instructional patterns are differentiated by different colors. From there, the student might progress to the mat 200 of FIG. 2 (numbered instructional positions) or the mat 300 of FIG. 3 (lettered instructional positions), etc. Normally, the mats will be formed with their increasing levels of physical difficulty or skill requirements corresponding directly with increasing levels of cognitive difficulty or skill requirements. However, this is not necessarily a requirement, and a review of FIGS. 1 through 14 will show that certain mat embodiments requiring relatively advanced physical or motor skills also require relatively basic cognitive skills, and mats having relatively higher cognitive skill level requirements may have relatively basic motor skill requirements to complete the exercise.
[0065] When a student has mastered most or all of the physical jumping exercises of the mats 100 through 1100 of FIGS. 1 through 11 , the instructor may add further challenge by attaching the various obstacles or raised mat portions of the mats 1200 through 1400 of FIGS. 12 through 14 . It will be understood that any of the previous mats 100 through 1100 may be modified to provide for the peripheral attachment of one or more mat overlays, if so desired. The various overlays or mat attachments may be “mixed and matched” as desired, assuming that appropriate attachments are provided along the peripheries of the base mats and the corresponding edges of the overlay obstacles or raised portions or areas.
[0066] The result is an extremely versatile means of providing simultaneous physical and academic training for students who require such. The present system may be applied to very young toddlers to older students who may be able to master the physical or motor aspects but need assistance in cognitive recognition of symbols (e.g., students learning English as a second language, etc.). The advantages provided by the consistent exercise and instructional patterns provide a great improvement over various exercise mat systems and the like developed in the past.
[0067] It is to be understood that the present invention is not limited to the embodiments described above, but encompasses any and all embodiments within the scope of the following claims.
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The motor and cognitive skills development system includes a series of exercise mats having various instructional patterns thereon in increasing degrees or levels of physical and mental difficulty from very basic to more advanced moves and instructions. Each mat includes a complete series of exercise instructions thereon, with the exercises ranging from a relatively simple series of progressive jumps along the mat, to more complex jumps requiring only one foot, lateral or backward jumps, jump turns, etc. The instructions may range from simple representations of foot patterns through representations of various objects, colors, alphanumeric indicators, caricatures, etc. The development system thus challenges students both physically and mentally, with the instructor determining the exercise(s) to be performed and the corresponding mats according to the needs of the student(s) and/or curriculum. The system is adaptable to very young children, autistic students, adults and younger people with special training or rehabilitation needs, etc.
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FIELD OF THE INVENTION
The present invention relates to a method for operating an open-end spinning machine with a plurality of open-end spinning devices and a service unit, which automatically services the spinning devices, wherein the open-end spinning devices each have a spinning rotor, whose rotor shaft is seated in the bearing wedge of an axial thrust-free support disk bearing and is positioned by means of a magnetic bearing. The invention further relates to a device for executing the method.
BACKGROUND OF THE INVENTION
In open-end spinning machines, it has been long known to seat the rotor shaft of the spinning rotor in the bearing wedge of a support disk bearing having two pairs of support rollers, since such bearings make possible very high rpm and have a long service life.
With support disk bearings of this type, the axes of the pairs of support rollers are customarily arranged slightly crossed, so that during operation an axial force component acts on the rotor shaft. This axial force component maintains the rotor shaft securely in contact with a mechanical axial bearing arranged at the end of the rotor shaft.
Although such rotor bearing as above described, and for example more fully disclosed in German Patent Publication DE 25 14 734 C2, has proven itself in actual use and large numbers thereof are in use, this type of rotor seating also has some disadvantages.
Not only is the spinning rotor limited to a structurally predetermined direction of rotation because of the crossed arrangement of the pairs of support disks, but the crossed arrangement of the pairs of support disks also results in increased friction in the area of the support disks/rotor shaft with the result, that the bearing faces of the support disks become heated. The coatings of the support disks are greatly stressed by this frictional heat, but additional energy is also required for overcoming this friction.
Furthermore, with this type of seating of the rotor shaft, the mechanical axial bearing arranged at the end of the rotor shaft is highly stressed, which has a negative effect on the service life of this bearing.
Although it has been possible to quite clearly improve the wear resistance of such axial bearings by the installation of a wear- resistant ceramic pin (as disclosed in German Patent Publication DE 41 17 174 A1), it continues to be necessary to sufficiently lubricate these bearings regularly. However, in spinning mills such bearings lubricated with oil are not without problems because of the almost unavoidable oil leaks.
A rotor bearing is known from the subsequently published German Patent Publication DE 197 29 191.0, which avoids the above described disadvantages. Although with this type of bearing, the rotor shaft of the spinning rotor is also seated in the bearing wedge of a support disk bearing, the axes of the two pairs of support disks are not crossed, but are arranged parallel with the rotor shaft and with one another. Thus, little or no axial forces act on the rotor shaft of the spinning rotor during operation. Instead, the axial positioning of the spinning rotor in the bearing wedge of the support disk bearing is provided by means of a magnetic bearing arranged at the end of the rotor shaft and having radially arranged magnetic bearing components. The special structural design of this magnetic bearing assures that the spinning rotor remains securely positioned even at rpm which are clearly greater than 100,000 revolutions per minute.
Because of its reduced energy requirements and increased service life, the support disk bearing in accordance with German Patent Publication DE 197 29 191.0 has indisputable advantages over support disk bearings with crossed pairs of support disks and mechanical axial bearings. Nevertheless, problems can arise when these support disk bearings are used, particularly in spinning mills in which open-end spinning devices with mechanical axial bearings as well as open-end spinning devices with magnetic rotor positioning are used. That is, the accidental installation of a rotor designed for a mechanical bearing in an axial thrust-free open-end spinning device with magnetic positioning of the spinning rotor can cause considerable damage to the respective spinning device because of the lack of an axial fixation of the spinning rotor which would then occur. In addition, such a spinning rotor installed in the wrong spinning device, which therefore is not fixed in its axial direction, represents a not inconsiderable risk of an accident, especially because of its high operating rpm.
A sufficient and dependable fixation of the rotor shaft in the bearing wedge of the support disk bearing, particularly when operating at high rpm, is only assured when the bearing components involved, i.e. the bearing component which has the permanent magnets and is arranged stationarily on the spinning device and the bearing component rotating with the bearing shaft, are exactly matched to each other. Thus, even small deviations of the bearing components can result in considerable damage.
SUMMARY OF THE INVENTION
Based on the above discussed prior art, it is an object of the present invention to develop a method and a device which assures a dependable operation of open-end spinning machines with axial thrust-free support disk bearings.
In accordance with the present invention, this object is attained by a method for operating an open-end spinning machine having a plurality of open-end spinning devices and a service unit for automatically servicing the spinning devices. The service unit has a device for piecing yams being spun at the spinning devices and a control device for controlling actuation of the piecing device. Each of the open-end spinning devices has a spinning rotor, a rotor shaft affixed to the rotor, an axial thrust-free support disk bearing forming a bearing wedge in which the rotor shaft is supported, and a magnetic bearing for positioning the rotor shaft. According to the present invention, an identification marker (preferably in the form of a security marking) is provided on each spinning rotor, and the service unit is equipped with a sensor device connected with the control device of the service unit for detecting the identification markers of the spinning rotors. Thus, the identification marker on a spinning rotor is detected by the sensor device prior to a yarn piecing operation at the associated spinning device and a yarn piecing operation is actuated by the service unit only upon detection that the identification marker identifies the spinning rotor to be compatible with the associated spinning device, thereby to prevent the yam piecing operation so as to prevent risk of damage or injury from use of improper spinning rotors.
The method in accordance with the invention assures that only appropriately embodied spinning rotors can be operated in an open-end spinning device having an axial thrust-free support disk bearing designed for the magnetic positioning of the spinning rotor. That is, with such a spinning device, the accidental use of a spinning rotor designed for an open-end spinning device with crossed pairs of support disks and a mechanical axial bearing is dependably prevented by means of the method in accordance with the invention by which the installation of a spinning rotor whose rotating bearing component does not meet the requirements is dependably detected.
In this connection, it is possible on the basis of the installed sizes of the spinning rotors to install such a wrong spinning rotor in a spinning device but, because of the lack of an identification marker, such a spinning rotor is immediately recognized by the sensor device connected to the control device of the service unit and determined to be questionable because of technological safety considerations. In such a case, the control device of the service unit immediately stops the piecing process.
In a preferred embodiment, an information carrier is used as the identification marker, which can contain a multitude of data, for example the type, the size, the model year, etc. of the spinning rotor. The data, which can be picked up by the sensor device of the service unit, are compared and evaluated in the control device of the service unit with preset data stored in an associated memory unit. Not only are spinning rotors, which are questionable because of technological safety considerations, identified by means of the comparison of the data, but it is also possible by means of such a comparison to assure, for example in connection with a batch change, that the spinning rotors which are correct for the respective yam batch according to considerations of spinning technology are always used. Thus, because of missing or incorrect data on the information carrier it is possible to detect that a spinning rotor is a spinning means which is questionable for technological safety considerations or is incorrect for reasons of spinning technology which, as already mentioned above, leads to the immediate stopping of the respective spinning station.
The identification marker on the spinning rotor is preferably in the area of its spinning cup, and unequivocally identifies it as a magnetically positionable spinning rotor which is structurally exactly matched to the stationary bearing component. This identification marker is detected by a sensor device at the service unit which, for example, may be advantageously arranged at the cleaning head of the service unit, and is decoded in the associated control device. Thus, a comparison between the spinning rotor data stored in a memory unit and the data of the identification marker is performed in the control device of the service unit. Piecing is attempted only if these data match. Data which cannot be identified, are missing, or are in error automatically lead to an immediate stop of the respective spinning station.
An electronic information carrier is preferably used as the identification marker. In such case, the electronic information carrier can contain a multitude of data, for example regarding the type of the spinning rotor, its size, its coating, its model year, etc. In a preferred embodiment, the electronic information carrier is designed as a so-called transponder. Such a transponder is a commercially available, passive electronic chip which, when needed, can be actuated via a transmitting and receiving device arranged on the service unit, and can then be read.
An alternative embodiment of an information carrier is a bar code. In such case, the sensor device on the service unit is designed as a scanner.
In a further aspect of the invention, it is also possible to arrange an identification marker on the spinning rotor which can be inductively detected by the sensor device.
Regardless of the type of information carrier arranged on the spinning rotor, it is assured in every case that a wrong spinning rotor, i.e. a spinning rotor which could lead to an endangerment of the spinning machine or the operators, is immediately recognized by the sensor device with the result, that the respective spinning device is stopped.
Further details, features and advantages of the invention will be described and understood from the description below of an exemplary embodiment represented by means of the accompanying drawings.
BRIEF DESCRIPTION OF THE DRAWINGS
FIG. 1 is a schematic side view, partially in cross-section, of a multi-station open-end rotor spinning machine having a service unit which automatically services the work stations, showing the service unit positioned at one work station,
FIG. 2 is a more detailed partially sectioned side view of the open-end spinning device of one work station of the spinning machine of FIG. 1, which spinning device has been opened by the service unit in the course of checking the spinning rotor by means of a sensor device arranged at the cleaning head of the service unit,
FIGS. 3 and 4 are side views of a spinning rotor and shaft showing different embodiments of an identification marker arranged on the spinning cup of the spinning rotor, and
FIG. 5 is an elevational view of the electronic information carrier indicated in FIG. 4 in an enlarged scale.
DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENT
Referring now to the accompanying drawings and initially to FIG. 1, a work station 2 of an open-end rotor spinning machine, identified as a whole by the reference numeral 1, is represented in a side view.
The spinning machine has a plurality of such work stations 2 aligned with one another along the length of the machine, each of the work stations 2 having an open-end spinning device 3 and a winding device 4. A sliver 6, delivered from spinning cans 5, is spun into a yarn 7 in the spinning device 3 in a known manner and is subsequently wound into a cheese 8 in the winding device 4. The cheese 8 is seated in a creel 9 in the winding device 4 and is driven via a friction roller 11 during the winding travel.
The removal of the finished cheeses 8 takes place by means of a cheese transport device 12 extending over the length of the machine.
The work stations 2 of the open-end spinning rotor machine 1 are serviced by an automatically operating service unit 10, which is supported on rails 14, 14' by its undercarriage 17. The rails 14, 14' preferably extend in the superstructure of the open-end spinning machine 1. It is known from numerous references and therefore not shown in greater detail that the service unit 10 has a plurality of manipulating devices for piecing or changing the cheese.
Among other things, such a service unit 10 has an unlocking lever 13, by means of which the open-end spinning device 3 can be opened and closed as needed, and a cleaning head 16 for cleaning the spinning rotors 15. Cleaning of the spinning rotors is periodically performed preventively as well as after a yarn break.
The cleaning head 16 can be extended by means of a drive 19 in the direction of the spinning housing 20 of the open-end spinning device 3. Both the unlocking lever 13 and the cleaning head 16 are standard components, known per se, of such service units 10.
In addition, the service unit 10 is equipped with its own control device 18, which is connected, for example via a machine bus, to a central control unit, not represented, of the open-end rotor spinning machine 1.
FIG. 2 represents a situation wherein the service unit 10 is locked to a work station 2 of the open-end spinning machine, and the spinning device 3 has been opened by means of its unlocking lever 13. Thus, the cover housing 21 of the open-end spinning device 3 has been tilted toward the front around a pivot shaft 22.
The structural design of such a cover housing 21, with a sliver opening device 23, a sliver guide conduit (not represented), a sliver conduit plate 24 and a yarn draw-off tube 25, is known and therefore should not require further explanation.
The spinning rotor 15, which revolves at high rpm during the spinning process, is seated by its rotor shaft 26 in the bearing wedge formed between the two pairs of support disks or wheels of an axial thrust-free support disk bearing 27. In particular, the axes 30 of the pairs of support disks extend parallel with the axis 29 of the rotor shaft 26. For sake of illustration of the spinning device components, only the one pair of support disks 28 which, viewed from the direction of the service unit, is on the right, has been represented in FIG. 2.
The axial positioning of the rotor shaft 26 of the spinning rotor 15 in the bearing wedge of the support disk bearing 27 is achieved via a magnetic bearing 31, which acts on the end of the rotor shaft. Such a magnetic bearing 31 has been extensively described, for example in German Patent Publication DE 197 29 191.0.
The magnetic bearing 31 has a stationary bearing component 45, which is fixed in place on the spinning housing and comprises two permanent magnet rings bordered by pole disks, and a rotating bearing component 32, which as represented in FIGS. 3 and 4, is formed by a bearing area 33 at the end of the rotor shaft 26.
The bearing area 33 at the end of the rotor shaft of the spinning rotor 15 is exactly matched in its structural layout to the bearing component 45 of the magnetic bearing 3 1. Therefore, correct and secure positioning of the spinning rotor 15 in the bearing wedge of an axial thrust-free support disk bearing is only assured, especially at high operating rpm, if the spinning rotor 15 has a bearing area 33 which is exactly matched to the stationary bearing component 45 of the magnetic bearing 31. In order to assure that in open-end spinning devices 3 with axial thrust-free support disk bearings and magnetic positioning of the spinning rotor only spinning rotors can be operated which are suited to this magnetic positioning because of their structural design, these spinning rotors 15 are marked in accordance with the present invention with an appropriate identification marker 34.
This identification marker 34 can either consist, as represented in FIG. 3, of a bar code 36 arranged in the area of the rotor cup 35 or, as represented in FIG. 4, of an electronic information carrier 37, for example a so-called transponder, or such other equivalent, substitute or otherwise appropriate means of identification.
Such an electronic information carrier 37, shown in an enlarged scale in FIG. 5, can be designed in the manner of a small chip card, for example. The electronic information carrier 37 has a transmission and receiving coil 38, as well as an integrated circuit 39. In this case, the transmission and receiving coil 38 and the integrated circuit are preferably embedded in an insulating layer 40, for example glass or the like. This insulating layer 40 constitutes a protective sheath for the relatively sensitive electronic device.
The electronic information carriers 37 are passive per se, i.e. they do not have their own energy source. The electronic information carriers 37 are only activated when they come into the range of an electromagnetic force field radiated by a sensor device 41. In this case an inductive energy and signal transmission takes place via a transmitting device and a receiving coil of the sensor device 41 and the transmission and receiving coil 38 of the electronic information carrier 37.
In comparison with optical identification markers, such as for example bar codes or the like, the previously described electronic information carriers have the great advantage that they are to a large degree insensitive to exterior influences, such as dust, fiber fluff, and the like, and are therefore very well suited for use in textile mills in particular.
The functioning of the device may thus be understood. In open-end rotor spinning machines 1, it has been long customary because of the high rpm of the spinning means to piece the yarn ends at the open-end spinning devices 3 by machines, i.e. by means of a service unit, not only for a new start-up of the spinning machine, for example following a batch change, but also after a yarn break.
For piecing for a new start-up of the machine, the service unit 10 is locked to the respective work station 2 and initially opens the open-end spinning device 3 by means of its unlocking lever 13. Thereafter a cleaning head 16 is placed on the spinning housing 20 and the spinning cup 35 of the spinning rotor 15 is cleaned. It is known that for this purpose the cleaning head 16 has a scraper 42, which can be extended into the interior of the rotor, and a rotor drive device 43.
In addition, a sensor device 41 is arranged in or on the cleaning head 16 and is connected via a signal line 44 to the control device 18 of the service unit 10.
Depending on the type of design of the identification markers 34 arranged on the spinning rotors 15, the sensor device 41 can be embodied as an optical sensor device, for example as a scanner, as an electronic transmitting and receiving device, as an inductive coil, etc. In the course of cleaning the spinning rotor 15, the sensor device 41 checks the identification marker 34 arranged on the rotor cup 35. In the case of an electronic information marker 34, for example, the data detected by the sensor device 41 are processed in the control device 18 of the service unit 10, i.e. such detected data are compared with data which have been filed in a memory unit 45 connected to the control device 18.
The further progress of the piecing process depends on the result of this comparison. If, for example, the sensor device 41 cannot detect any identification marker 34 on the rotor cup 35, or if the data on the identification marker 34 do not correspond with the data filed in the memory unit 45, the piecing attempt is immediately stopped by the control device 18 of the service unit 10, and a warning signal, e.g., a red warning light, is activated at the respective spinning station.
It will therefore be readily understood by those persons skilled in the art that the present invention is susceptible of broad utility and application. Many embodiments and adaptations of the present invention other than those herein described, as well as many variations, modifications and equivalent arrangements, will be apparent from or reasonably suggested by the present invention and the foregoing description thereof, without departing from the substance or scope of the present invention. Accordingly, while the present invention has been described herein in detail in relation to its preferred embodiment, it is to be understood that this disclosure is only illustrative and exemplary of the present invention and is made merely for purposes of providing a full and enabling disclosure of the invention. The foregoing disclosure is not intended or to be construed to limit the present invention or otherwise to exclude any such other embodiments, adaptations, variations, modifications and equivalent arrangements, the present invention being limited only by the claims appended hereto and the equivalents thereof.
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In an open-end spinning machine (1) with a plurality of open-end spinning devices (3), each having a spinning rotor (15) whose rotor shaft (26) is seated in the bearing wedge of an axial thrust-free support disk bearing (27) and is positioned by a magnetic bearing (29), and a service unit (10), which automatically services the spinning devices, a sensor device (41) is provided on the service unit (10), which is connected to the control device (18) of the service unit (10) and checks an identification marker (34) applied to each spinning rotor (15). The control device (18) actuates a yarn piecing operation by the service unit only upon detection of an identification marker (34) identifying the spinning rotor (15) to be compatible with the associated spinning device.
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BACKGROUND OF THE INVENTION
[0001] 1. Field of the Invention
[0002] The present invention relates to a hydro absorbent compound used as a soil additive. This formula contains a compound comprising cross-linked potassium based highly absorbent copolymers together with slow and fast soluble nutrients obtained from mineral and organic substances including in some cases extracts from sea kelp, as growth stimulants.
[0003] Hydro absorbent polymers are used to solve water shortage problems especially in places where only rainwater is available for shorts periods every year. These copolymers have the ability to absorb and adsorb water and water soluble substances dissolved in the water.
[0004] 2. Description of Related Art
[0005] Hydro absorbent polymers used as soil additives to enhance water availability in plants have been researched for many years, but only since 1990, has their use has been considered feasible, mainly due to their high cost and toxicity. These factors have been corrected or eliminated in some type of copolymers presently available.
[0006] In patent application WO98/12154 it is mentioned that Fikhof studied the influence of a hydrophil polymer in water requirements for pots and containers. This same patent application mentions that Ghering and Lewis reported the effect of hydrogels in wilted and drought stressed nursery plants. Later, W. G. Pill studied the use of acrylamide based polymer gels as growing media for tomato seedlings because the hydrogels showed sensibility in the presence of salts. This resulted in the focusing of attention towards the acrylamide polymers instead of the ionic acrylates, even though the super absorbent acrylamides showed less water absorption qualities in the presence of soluble salts.
[0007] In patent application WO9812154 it is also mentioned that sodium polyacrylate polymers tend to condensate during drought periods, forming cross-links which inhibit re-initiation process when they are re-humidified, even when they are used in limited humidity and drought cycles. It is also mentioned that sodium polyacrylate inhibits plant growth and in some cases is even toxic to plants.
[0008] This inhibition of growth or toxicity is believed to be caused by the presence of sodium ions in the sodium polyacrylate chain which are exchangeable. These ions are absorbed by clay particles or otherwise tend to suffer cation exchange with the plant roots surface. As a consequence, it yields a condition analogous to an alkaline soil which generally tends to affect or inhibit plant growth.
[0009] Potassium based acrylamide copolymers, like the ones described in U.S. Pat. No. 5,649,495, have been proven to have greater gel stability under soil pressure, less cost and no toxicity. The formula that contains the potassium ion as organizing axis of the copolymeric chains is not toxic and it does not damage the plants, according to Williams, who is mentioned in patent application WO98/12154. U.S. Pat. No. 5,209,768 describes an acrylamide copolymer in liquid gel form for the improvement of sod growth and promotion of root growth.
[0010] The potassium/ammonium based acrylamide copolymers of the present invention are known in the prior art and have been used as soil additives.
[0011] Patent application EP0386345 refers to an invention containing nutrients for soil, without mentioning in what proportions and describes a rate of application of the product described as 5 kgs.(11 lbs.) per cubic meter of soil. The present invention achieves its results much more economically and with greater water retention rates as explained herein.
BRIEF SUMMARY OF THE INVENTION
[0012] In order to improve and achieve adequate soil humidity, raise nutrition standards and create favorable conditions for a microbiological development of the soil, the present invention relates to a new formula comprising a blend used as a soil additive for the improvement of the soil containing the aforementioned known polyamide/polyacrylate copolymer together with organic and mineral nutrients presented as slow release and fast solubility fertilizers. A second embodiment of the invention includes the addition of sea kelp, which formula has broader nutritional properties through the inclusion of additional vitamins and proteins. These compositions offer a synergy over use of the individual ingredients alone.
DETAILED DESCRIPTION OF THE INVENTION
[0013] The absorbent qualities of the new formula consist of the aforementioned copolymer which has previously been used alone as a soil additive and contains by weight, 4-6% acrylic acid, 30-40% acrylamide, 40-50% potassium polyacrylate, 4-6% ammonium polyacrylate and 7.5-9% water. The copolymer is included in the composition of the present invention in a ratio of 60-90% of the total weight of the composition.
[0014] The primary characteristic of the copolymer is water retention through mechanisms of absorption and adsorption. This means that water enters and also adheres to the copolymer particles. The hydric retention is present in chemical links known as a “hydrogen bridge”. They present a definite affinity with water molecules.
[0015] The mineral and organic components, which are present in this invention in a proportion ranging between 0.86-1.57%, are dispersed in the soil because of the presence of an inert carrier material which may be found in a proportion from 2% to 7.5% of the composition of the invention. Each component contributes an unexpected synergy to the recuperation of the soil microbiology.
[0016] The substances that are released through the slow release fertilizers and organic soluble fertilizers and the sea kelp, are stored in the copolymer or together with the copolymer and in the soil solution in the vicinity of feeding roots without being lost or transferred to deeper layers by lixiviation. The sea kelp have the following substances: essential amino acids (histine, isoleucine, leucine, lysine, methionine, phenialanine, treonine, tryptophane, and valine), non essential amino acids (alanine, aspartic acid, cistine, glycine, glutamic acid, proline, serine and tyrosine), and vitamins (C-ascorbic acid, vitamin E: tocopherol, Vitamin A: fucoxantine, carothene, menadione K 3, riboflavine B2, Tiamine B1, pantothenic acid B5, Piridoxine B6, Folic acid B9, biothine H, cobalamine B12 and colecaldiferol D3).
[0017] The slow release fertilizers are encapsulated such that they only start to mobilize to the exterior when the soil temperature is above 15 degrees C. The degree of fluidity of the nutrients diminishes in cold weather, therefore, the fertilizers are available during a period ranging from 10-18 months. This reduces fertilizing cost. The soluble fertilizers are dissolved rapidly in the water, which in turn is absorbed by the copolymer. The quick soluble fertilizers accomplish immediate rehabilitation of plants that may be weak due to lack of nutrients. The slow release organic fertilizers biologically nurture the soil. This yields a benefit to the microbiological system which stimulates it to multiply, achieving a better response to organic other fertilizations that may occur later in the soil.
[0018] Sea kelp provides complementary nutritional aspects that normally are not considered in mineral fertilization. The synergy of these elements promotes the microbial activity on the soil encouraging humus formation, which is the main nutritional support of plants.
[0019] The invention has neutral pH and is capable of regulating pH no matter the tendency of soil (acid or alkaline).
[0020] The potassium and ammonium based copolymers of this invention are non-toxic for plants, soil microorganisms and under ground/surface water because they include an almost imperceptible quantity of free monomers (less than 25 mg/kg for acrylamide and less than 600 mg/kg for acrilic acid).
[0021] In an embodiment of the present invention the composition used as an additive to condition the soil includes a composition comprising:
[0022] The below described potassium and ammonium based acrylamide copolymer in a proportion of 60% to 95% of the total weight of the total composition;
[0023] Pyroclastic rock as a carrier in a proportion of 3% to 28% of the total weight of the composition; and
[0024] A mineral based nutrient in a proportion of 2% to 12% of the total weight of the composition.
[0025] The potassium-ammonium acrylamide copolymer comprising:
[0026] Acrylamide in a proportion of 30% to 40% of the total weight of the copolymer;
[0027] Acrylic acid in a proportion of 4% to 6% of the total weight of the copolymer;
[0028] Ammonium polyacrylate in a proportion of 4% to 6% of the total weight of the copolymer;
[0029] Potassium polyacrylate in a proportion of 40% to 50% of the total weight of the copolymer; and
[0030] Water in a proportion of 7.5% and 9.5% of the total weight of the copolymer
[0031] In another embodiment the composition is used as an additive to condition the soil and comprises:
[0032] The above-described copolymer in a proportion of 70% to 88% of the total weight of the composition;
[0033] Pyroclastic rock as a carrier material in a proportion of 9% to 24% of the total weight of the composition; and
[0034] Mineral based nutrient in a proportion of 3% to 6% of the total weight of the compound.
[0035] In another embodiment of the invention the composition is used as an additive to condition the soil and comprises:
[0036] The above-described copolymer in a proportion of 60% to 92% of the total weight of the composition;
[0037] A polyclastic rock in a proportion of 2% to 21% of the total weight of the composition; and
[0038] A mineral based nutrient in a proportion of 3% to 8.5% of the total weight of the composition; and
[0039] A sea kelp based organic nutrient in a proportion of 5% to 10.5% of the total weight of the composition.
[0040] In another embodiment the composition is used as an additive to condition the soil and includes:
[0041] The above-described copolymer in a proportion of 65% to 86% of the total weight of the composition;
[0042] Pyroclastic rock as a carrier material in a proportion of 7% to 18% of the total weight of the composition;
[0043] Mineral based nutrient in a proportion of 2% a 6.5% of the total weight of the composition; and
[0044] Sea kelp based organic nutrient in a proportion of 3% to 10.5% of the total weight of the compound.
[0045] In the present invention, the term “hydro absorbent” should be understood as absorbent and/or adsorbent. The nutritious substances are based on Nitrogen, Potassium, Phosphorus, Calcium, Sulphur, Magnesium, Iron, Molybdenum, Copper, Zinc, Manganese and Boron. These nutrients are combined to form complex fast and slow solubility fertilizers. They act in synergy with the copolymer, without regard for their own level of concentration.
[0046] The invention is comprised of the afore-described copolymer in a proportion of 60% to 95% by weight of the total composition, and preferably between 70% and 88% by weight of the total composition. The variation exists because different soils and plants have different water and nutrient requirements. The copolymer is biodegradable, non-toxic and does not pollute soils or ground water.
[0047] Water inside the copolymer is fixed inside the chemical structure and does not leak because of the known hydrogen bridge structure which the water molecule forms with the copolymer. This type of link has an affinity for water molecules and is responsible for the water being stored inside the molecule with a retention force or negative pressure of 0.33 to 15 bars, the same superficial tension range that plants need to survive. Water enters the copolymer and expands the soil, forming cavities in the ground, so that water, air and new roots can enter the voids. The dynamics of the expansion and contraction cycle of the copolymer granules depends on the water requirements of the crops and availability of watering/irrigation. Each cycle enhances soil porosity and improves aeration. This is important in the process of cellular breathing and ammonium oxidation, which is easier for the plants to assimilate as NO3 rather than as NH4+, which develops toxins in oxygen deprived soil.
[0048] The hydro absorbent copolymer is pH neutral, with a 7 pH value. It can regulate pH regardless of the soil type (alkaline or acid). The Potassium ions partially yield space to other ions, such as Sodium, and as a result alkaline elements are forced out of the soil solution. After a treatment with calcium carbonates, the sulphates or carbonates formed fall without harmful effects. Tests have shown pH values lowered from 9 to 7 and even to 6.5. When the soil solution has a low pH value (many free hydrogen ions), the radical amide ion (NH2−) which is also part of the copolymer retains and blocks those ions because it has affinity for the hydrogen ion. The captured ion forms water molecules, hydroxides and organic acids.
[0049] The mineral and organic elements present in this invention work in synergy to recuperate soil microbiology, and provide nourishment that beneficial fungus and bacteria needed for the optimal exchange of cations, oxygen, hormones, vitamins and CO2 with the plant roots. Slow release, soluble organic fertilizers and sea kelp extracts deliver substances that remain stored inside the copolymers and the soil solution avoiding waste and movement away from the feeding roots. The copolymers store these substances until the roots demand them through suction.
[0050] The slow release fertilizers are encapsulated so that the elements they contain are activated when temperatures reach 15 degrees C. As temperature increases, so does the fluidity of the nutrient. This characteristic of the invention is critical for the conservation of nutrients during cold season watering periods. Plant metabolism and nutrient consumption is reduced during the colder winter months. Therefore, if fertilizers are not controlled by outside temperature, they will dissolve in water and gravitate toward deeper layers rather than remaining in close proximity to feed the plant. Unlike other products in the market, this characteristic of the invention reduces fertilizing costs and promotes vigorous and steady growth because applied fertilizers remain available to the plant 10 to 18 months.
[0051] The nutrient retention is designed so that a plant may access them at the time and the amount they are needed. Thus, fertilizers are not wasted with simple watering, yielding a much more economical product.
[0052] The fast soluble fertilizers dissolve rapidly in water which is then absorbed by the copolymer. These soluble fertilizers are available for immediate rehabilitation of weak and underdeveloped plants.
[0053] The organic fertilizers, which are also slowly delivered into the soil, provide biological nourishment. This means that the microbiological system in the soil is favored and motivated to multiply. This facilitates a better response to further organic fertilizations in the soil.
[0054] When the product contains at least 5% sea kelp, the vitamin and protein compound enhances the nutritional value of treated plants and soils. The addition of sea kelp improves rehabilitation of microbial presence in the soil. This means that poor soils can become active and capable of responding well to organic and inorganic fertilizer application because the organisms responsible for organic matter combustion and soil oxygenation are increased in number. Sea kelp contains microelements, 14 vitamins-including vitamin B12−(not found in terrestrial plants) and vitamin E, with a complex variety of isomers, only found in seed oil and wheat germ oil. It also has 16 amino acids, phytohormones such as cytoquinine, axing and gibereline. These components complement the nutrients aspects not normally considered in mineral fertilization. The synergy of these elements promotes microbial activity in the soil, and triggers a sequence of biochemical reactions, which develop into humus in the soil, which comprises the main source of nutritional support for the plants. All these components act in synergy promoting an interaction between the biotic and abiotic elements of the soil.
[0055] The greater availability of water in the soil increases available nutrients and fosters root growth, which promotes more vigorous plants. The root system tends to grow to greater size because when plants require more water, the root system expands to access the water source available in the copolymer gel granules suspended in surrounding soil. Tests show that application may not result in immediate obvious growth because underground development begins first. However, after a short period, many new sprouts will appear.
[0056] Water release is accomplished through osmosis. The hydrated granules in the copolymer release water only if surrounding materials have a lower concentration of water than that inside the granules. This reduces water loss due to percolation or evaporation. Therefore, humidity concentration levels do not change drastically, avoiding drought stress in the plant and considerable loss of the elements applied to the plant and soil, all of which combine to improve production yield. Osmotic strength depends on water and soil quality, because the strength exerted against the gel is controlled by the water and salt concentration in the soil or growing media. Therefore, water is released when salt concentration outside the gel is greater than within and enters. For this reason, hydro absorbent copolymers do not reach their maximum size when salt water is used.
[0057] The copolymer remains active in the soil for over 5 years. Its degradability is not complete during that time due to the chemical reaction that causes the humification of organic matter. This is evidence that the copolymer is non-toxic and completely degradable. By the end of its active life, it remains in the soil as a potassium residue, which is a nutrient.
[0058] Gravitational water in the soil is the main carrier and means of detection of radicular exudates and sexual hormones of phytoparasite nematodes. The copolymers retain the water, hence reducing the opportunity for nourishment of nematodes and the chances of their reproduction. This reduces their population and related plant damage. Therefore, the copolymer allows the avoidance or reduced application of pesticides.
[0059] These copolymers elaborated with potassium ion and ammonium salt, posses an almost imperceptible quantity of free monomers (less than 25 mg/kg of product). Laboratory testing with the OECD method has qualified the copolymer as non toxic to plants, soil microorganisms, underground water and surface water.
EXAMPLES
[0060] The following examples show different formulations of the hydro absorbent compound in various applications. Such examples are merely for illustrative purposes and as will be understood by those of ordinary skill in the art, these examples do not limit, in any way, the potential applications and formulations of the invention.
Example 1
[0061] In the first formulation, the hydro absorbent composition comprising:
The acrylamide copolymer as described above 62% Carrier Material 27% Nutrients 11%
[0062] On flowerbed tests, such as Hydrangea SP, the flower diameter of the bloom was increased over 30%. The blooming period was increased by 50%.
Example 2
[0063] In the second formulation, the hydro absorbent composition comprising:
The acrylamide copolymer as described above 87% Carrier Material 9% Nutrients 4%
[0064] Forestry species such as Eucalyptus ( Eucalyptus Rostrata ) and Pine ( Pinus Radiata ), demonstrated a survival rate of 95% under conditions of 70 days without watering in very poor soil. Under similar circumstances, a control group without the application of the composition of the invention showed a survival rate of 0%, that is no plants survived.
Example 3
[0065] In the third formulation, the hydro absorbent composition comprising:
The acrylamide copolymer described above 90% Carrier Material 4% Nutrients 1.7% Sea kelp 4.3%
[0066] When this formulation was used in farming trials, production yield increased over 30% (100% in cold weather potato, 85% in oats, 55% in corn, 53% in sugarcane, 40% in asparagus and 35% in orange.)
Example 4
[0067] In the fourth formulation, the hydro absorbent composition comprising:
The acrylamide copolymer as described above 67% Carrying Material 18% Nutrients 6.5% Sea kelp 8.5%
[0068] On slope trials, this formulation controlled erosion when combined with hydro seeding systems. In slopes exceeding 45 degrees, more than 95% was successfully revegetated. Humidity retention and adequate application of the nutrients contained in this formula, which acted as a substrate, contributed to revegetate very poor degraded soils.
[0069] Typical formulations for the compositions of the present invention are shown in the following Tables:
TABLE NO 1 Acrylamide Copolimers 95% 60% Carrier material (pyroclastic 3% 28% rock) N 0.8% 7% P2O5 0.5% 3% K2O 0.6% 1.8% B 4 ppm 10 ppm Cu 10 ppm 25 ppm MgO 360 ppm 900 ppm Fe 30 ppm 75 ppm Mn 16 ppm 40 ppm Mo 4 ppm 10 ppm Zn 4 ppm 10 ppm Growth enhances 472 ppm 1180 ppm
[0070] [0070] TABLE NO 2 Acrylamide copolymers 88% 70% Carrier material-pyroclastic rock 9% 24% N 1.2% 3% P2O5 0.7% 1.1% K2O 1% 1.7% B 4 ppm 10 ppm Cu 10 ppm 25 ppm MgO 360 ppm 900 ppm Fe 30 ppm 75 ppm Mn 16 ppm 40 ppm Mo 4 ppm 10 ppm Zn 4 ppm 10 ppm Growth regulators 472 ppm 1180 ppm
[0071] [0071] TABLE NO 3 Acrylamide Copolimers 92% 60% Carrier material (pyroclastic 2% 21% rock) N 0.8% 4% P2O5 0.2% 2% K2O 0.4% 2% Ca 1000 ppm 2500 ppm B 10 ppm 24 ppm Cu 8 ppm 19 ppm MgO 770 ppm 1925 ppm Fe 22 ppm 56 ppm Mn 13 ppm 30 ppm Mo 3 ppm 8 ppm Zn 4 ppm 9 ppm Carbon hydrates 3% 7.5% Proteins 0.75% 1.25% Fibers 0.5% 1% Vitamin 500 ppm 1450 ppm Fat 0.35% 0.56% Growth regulators 375 ppm 375 ppm
[0072] [0072] TABLE NO 4 Acrylamide Copolimers 86% 65% Carrier material (pyroclastic 7% 18% rock) N 1% 3% P2O5 0.5% 1% K2O 0.9% 2% Ca 1000 ppm 2500 ppm B 10 ppm 24 ppm Cu 8 ppm 19 ppm MgO 770 ppm 1925 ppm Fe 22 ppm 56 ppm Mn 13 ppm 30 ppm Mo 3 ppm 8 ppm Zn 4 ppm 9 ppm Carbon hidrates 7.5% Proteins 0.75% 1.25% Fibers 0.5% 1% Vitamin 500 ppm 1450 ppm Fat 0.35% 0.56% Growth regulators 375 ppm 940 ppm
[0073] This invention as opposed to similar ones relying on sodium-based copolymers, has a lower amount of free monomers which makes it fit for direct consumption horticulture. It also has the capacity to retain water in a mode that renders it available as soil and plant conditions require it. This means that the water is retained in the gel particles as time goes by, which does not occur with sodium based copolymer compounds.
[0074] This shows that the gel is stable in time regardless of how dry it might be after a drought period. Because the product will re-hydrate when irrigation resumes, the compound will behave as a newly applied product.
[0075] This invention surpasses those with 100% pure copolymers, because it contains nutrients that have shown to help plants react positively in periods as short as a few hours thereby decreasing damages due to stress and soil mishandling. The present invention is used in ratios ranging from 1 to 2 Kg per cubic meter of soil and water and nutrient retention capacities are 75% to 125% higher than the use of nutrient additives alone.
[0076] The nutritional quality of food is lower every day. This invention, allows nutrition levels of the population to be increased at no additional cost to the public; because plants will increase production of photosynthates due to the constant availability of water plus nutrients.
[0077] Also, application of this invention will promote an increase in the quality of previously degraded soils. The quality of life can be enhanced by the promotion of forests and green spaces, thus contributing to improve the environment.
[0078] Field tests have demonstrated that the independent application of each of the components of the invention (nutritional and hydro absorbent components) do not achieve the benefits of the composition of invention.
[0079] A large number of field tests have been conducted in diverse soils and climate conditions and have demonstrated that the effect of the potassium-based copolymer composition of this inventions to reduce plant mortality in drought conditions. It further reduces the incidence of nematodes by at least 95%. Significant increases in production against pilot/control groups of similar plants were documented during drought seasons, due to increased production through a better assimilation of nutrients, nutrient retention or the creation of better chemical soil conditions such as enhancing soil pH.
[0080] The results have been obtained on diverse agriculture and forestry crops. For example, on forage barley 85% more yield was obtained even under sporadic rain conditions. On potato, under the same conditions, a 150% increase in yield was achieved. On corn, a 100% higher yield was achieved and on high altitude cereals, such as quinoa and kiwicha, a 70% higher yield was achieved. Sugarcane yielded a 53% increase, and asparagus yielded a 25% increase on a desert with a soil temperature of over 50 C. (over 122 F.) carob trees achieved 95% survival rates against 87% mortality rate of control plants. On sandy beach areas subject to unfavorable conditions such as sea breeze, lack of soil and salt conditions, it is extremely hard to establish grass, however, using the invention, it was successfully performed.
[0081] Hydro-seeding tests were conducted to determine the invention's potential to control erosion on steep sloped sea side areas with almost no soil, obtaining 100% establishment. The species used was rye grass ( lolium perenne ) and the terrain included slopes exceeding 45 degrees of inclination and containing almost no soil or an extremely high surface stone content. The successful results are attributed to the combination of the hydro absorbent and the nutritional and organic components. Plant survival was possible with low water consumption even in extremely rocky areas. This test also demonstrated that unstable terrain on coastal cliffs could be controlled when the invention is applied to act as a substrate holding the plants, and providing the water and nutrients necessary for plant development.
[0082] In mining developments, with extreme weather, rugged lands and degraded soils it has been proven that the invention behaves as a substrate which helps rejuvenate areas affected by mining through regeneration.
[0083] The invention has helped obtain a less expensive product, that is more absorbent and with new nutritional elements such as the one from algae extract. This helped increase by at least 30% the benefits to the public through raw material savings and increased production.
[0084] The new organic substances in the invention help regain soil organic activity because it forms the nutritional platform of the soil making it stable. It also forms the colloid, the union of the organic and mineral parts.
[0085] After many years of thorough research on lands with diverse climates, soils and crop handling, we have discovered optimal dosage ranges to be used according to different crop types. Field tests have also shown reduced costs, increase in yields and profitability with better results.
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The invention pertains to a compound used as a soil additive to enhance farming, forestry, ornamental and landscaping production in conditions of droughts and insufficient fertile soils. This composition contains potassium based absorbent acrylamide crossed linked copolymers, together with nutritional elements of fast and slow solubility, derived from mineral and organic substances, including in some cases, extracts from sea kelp as growth stimulants. This soil additive is used in varied dosages according to the type of crop, soil and climate. In field tests it has demonstrated great efficiency in enhancing crop production and/or higher quality crops and/or larger bloom and/or saving of irrigation water.
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