description stringlengths 2.98k 3.35M | abstract stringlengths 94 10.6k | cpc int64 0 8 |
|---|---|---|
TECHNICAL FIELD
This invention relates to managing storage stability.
BACKGROUND
In a complex system such as a computer processor based system, if an error is detected frequently, system reliability may be poor even if the error is due to an intermittent fault. The component having an intermittent fault which is detected frequently may eventually cause a fatal fault even if the component does not have a fatal fault. Also, the component lowers system reliability and requires time for recovering the fault (e.g., correcting the error), thereby deteriorating the system performance.
As is known in the art, large host computers and servers (collectively referred to herein as “host computer/servers”) require large capacity data storage systems. These large computer/servers generally include data processors, which perform many operations on data introduced to the host computer/server through peripherals including the data storage system. The results of these operations are output to peripherals, including the storage system.
One type of data storage system is a magnetic disk storage system. Here an array or bank of disk drives and the host computer/server are coupled together through a system interface. The interface includes “front end” or host computer/server controllers and “back-end” or disk controllers. The interface operates the controllers in such a way that they are transparent to the host computer/server. That is, data is stored in, and retrieved from, the bank of disk drives in such a way that the host computer/server merely thinks it is operating with its own local disk drive. One such system is described in U.S. Pat. No. 5,206,939, entitled “System and Method for Disk Mapping and Data Retrieval”, inventors Moshe Yanai, Natan Vishlitzky, Bruno Alterescu and Daniel Castel, issued Apr. 27, 1993, and assigned to the same assignee as the present invention.
Given the large number of disk drives in a typical implementation, there is a reasonable likelihood that one or more disk drives will experience an operational problem that either degrades drive read-write performance or causes a drive failure. This is because disk drives are complex electromechanical systems. Sophisticated firmware and software are required for the drive to operate with other components in the storage system. The drives further incorporate moving parts and magnetic heads which are sensitive to particulate contamination, and electrostatic discharge (ESD). There can be defects in the media, rotational vibration effects, failures relating to the motors and bearings, and other hardware components or connections. Some problems arise with respect to drive firmware or drive circuitry. Environmental factors such as temperature and altitude can also affect the performance of the disk drive. Thus, drives can fail and the failure can be significant if there is a nonperformance of the drive.
Many disk drives used in data storage systems include firmware/processor which monitors the performance and operation of the disk drive. If such firmware/processor detects a fault in such operation, it sets a bit in a register in the disk drive and takes such disk drive in a bypass state (i.e., off-line) (also known as bypass condition) for a short period of time, typically in the order of, for example, 200 milliseconds, thereby disabling its access by the host computer. More particularly, the system interface includes a diagnostic section (which may be included within the controllers) which regularly polls (i.e., inspects) at a rate of typically 500 milliseconds, for example, the state of the bit register in each of the disk drives. In one system, whenever the diagnostic section detects that the bit register in a disk drive has been set, i.e., the disk drive is in a bypass condition, such bypass condition is reported to the system interface control section (i.e., the controllers) thereby advising the controllers to no longer access (i.e., write to or read data from), the bypassed disk drive. It is noted that the diagnostics, when it detects a bypass condition, i.e., a set bit, does not know whether the bypass is only temporary or permanent. That is, the diagnostics does not know whether the disk drive will have its bypass condition removed and thereby again be operational. The polling continues and if the disk drive bypass condition is removed, the system interface commences a rebuilding of data operation using error correction and detection codes (i.e., a data reconstruction operation). If during the rebuilding process, a new poll indicates that the disk drive is again in a bypass condition, the system interface must again re-start the data rebuilding process. Further, once the disk drive is placed in a non-accessible condition, the system interface commences the rebuilding of data operation using error correction and detection codes and using a spare disk drive in the array or bank of disk drives, sometimes referred to as a “hot spare” disk drive, to immediately and automatically replace the bypassed disk drive. Thus, once a hot space switches into the system, the data reconstruction must be made using the hot spare before the data can be re-written from the hot spare back into the bypassed, and now perhaps physically replaced disk drive. This process can take from between 30 minutes to perhaps several days. Thus, the possibility of repeated response to bypass condition bits by the disk drive reduced the efficiency of the data storage system and leaves the data vulnerable to data loss should a second fault occur.
SUMMARY
Storage stability is managed. It is detected that a disk drive is requesting to be taken offline. The disk drive is begun to be treated as being in a probation state. If within an acceptable period of time the disk drive requests to be put back online, treatment of the disk drive as being in a probation state is stopped, and only any portions of the disk drive data that were the subject of write requests involving the disk drive while the disk drive was being treated as being in a probation state are rebuilt.
The details of one or more embodiments of the invention are set forth in the accompanying drawings and the description below. Other features, objects, and advantages of the invention will be apparent from the description and drawings, and from the claims.
DESCRIPTION OF DRAWINGS
FIG. 1 is a block diagram of a system adapted to operate in accordance with the present invention; and
FIG. 2 is a flow diagram of the process in accordance with the invention.
Like reference symbols in the various drawings indicate like elements.
DETAILED DESCRIPTION
As described below, when a drive requests to be taken offline (i.e., indicates a bypass condition), it is marked as probational, and only its sectors to which I/O writes are directed are later rebuilt.
Referring now to FIG. 1 a data storage system 10 is shown having a host computer/server 12 coupled to a bank or array of disk 14 drives through a system interface 16 . The system interface includes a plurality of front-end controllers coupled to the host computer/server and back end directors coupled to the bank of disk drives in a controller section 18 . A diagnostic section 20 is shown, it being noted that the diagnostic section 20 may be separate from the controller section 18 or may be distributed within the plurality of controllers. It is noted that one of the disk drives 14 in the bank 17 of disk drives 14 may be a hot spare disk drive 14 S.
It is noted that each one of the disk drives 14 includes firmware/processor, not shown, for controlling the disk drive 14 in any conventional manner, it being noted that each disk drive includes a bit register 22 for storing a bit when such disk drive has been placed by the disk drive firmware/processor in a bypass or down condition. In the absence of this bit, the disk drive 14 considers itself operational and available to the system interface 16 .
The diagnostic section 20 includes a register 24 for each one of the disk drives 14 . Each one of the registers 24 is available to store a disk access inhibitor flag when the system interface 16 determines that the disk drive 14 corresponding to such register 24 is not available to the controllers in the system interface 16 for either storing data from the host computer/server 12 or for reading data from the disk drive 14 requested by the host computer/server 12 . Thus, while the disk drives 14 themselves have their own firmware/processor for determining whether such disk drive 14 should be placed in a bypass condition and hence in a “down” or inoperative condition, the system interface 16 may, in accordance with a process to be described in more detail in connection with FIG. 2 , determine that a disk drive 14 should be inaccessible for use by the system 10 . In such case, i.e., that the disk drive 14 should be placed in an inaccessible condition, the system interface 16 sets the disk access inhibitor flag in the diagnostic section 20 register 24 associated with such inaccessible disk drive 14 .
In some circumstances the system interface 16 may determine that the disk drive 14 corresponding to such register 24 should be placed in a probation state (in at least some implementations each one of the registers 24 is also available to store a disk probation flag to so indicate.) When the disk drive 14 is in the probation state, the disk drive 14 is not available to the controllers in the system interface 16 for either storing data from the host computer/server 12 or for reading data from the disk drive 14 requested by the host computer/server 12 , but the system interface acts to allow I/Os involving the drive to be completed. In particular, the system interface allows I/O reads and writes to be completed without any interaction with the disk drive 14 . In the case of I/O reads, existing Redundant Array of Independent Disks (RAID) functionality or other data protection functionality is relied on in correctly serving up the data by requested by the host computer/server 12 , without the benefit of disk drive 14 . In the case of I/O writes, the system interface writes nothing to the disk drive 14 but keeps track of which sectors of disk drive 14 are the subject of I/O writes while the disk drive 14 is in the probation state. (After the probation state is no longer in effect, these sectors are rebuilt using existing RAID or other data protection functionality.)
Briefly in accordance with a disk drive handling technique, the system 10 puts the disk drive in a probation state whenever a disk drive 14 has placed itself in a bypass condition. The disk drive 14 operates to set a bit therein when the disk drive 14 has placed itself in a bypass condition. During each polling event, the system 10 determines: (1) whether the bit has been set; and (2) how the disk drive should be treated. Depending on various conditions as specified below, the disk drive 14 is optionally (1) made or left accessible to the system 10 , (2) made or left inaccessible to the system 10 , or (3) put or left in the probation state (options (1) and (2) also mean the probation state is no longer in effect).
In accordance with the technique, in the event the disk drive places itself in a bypass condition and this falls within the number of such events allowed within a tracking period (e.g., 1 event within 24 hours), the disk drive is put in a probation state for up to a probation period (e.g., 30 minutes). If the disk drive requests to be brought back online (i.e., takes itself out of the bypass condition) before expiration of the probation period, the disk drive is made accessible to the system 10 and its sectors are rebuilt as necessary according to sector tracking when the probation state was in force. If the disk drive requests to be brought back online after expiration of the probation period, the disk drive is made accessible to the system 10 but is treated as a new, unfamiliar disk drive and therefore is subject to normal processes such as rebuilding the entire drive's data.
In the event the disk drive places itself in a bypass condition and this exceeds the number of such events allowed within the tracking period, the disk drive is made inaccessible to the system 10 . In at least some implementations, this may be done by use of the inhibitor flag described above.
This technique reduces the chance that the system 10 will unnecessarily perform a full rebuild of the disk drive, putting a burden on the storage system, and potentially causing a data unavailable/data loss situation in the event of another drive failure during the rebuild. This technique allows the storage system to accommodate temporary unavailability (self-bypassing) of a disk drive, e.g., as a result of the disk drive resetting itself after an error, or during a disk drive firmware upgrade, or when a power down or power off command is issued.
In particular, the technique allows I/Os to continue to be directed to the disk drive while it is temporarily offline (e.g., for up to 30 minutes), without generating I/O timeouts that could ultimately cause the disk drive to be deemed non-functional, and to be removed as such by direction of a device handler or other functionality that receives the timeouts.
Referring now to FIG. 2 , a flow diagram of an example process of the technique is shown. As noted above, the diagnostic section 20 continuously polls each one of the disk drives 14 ; here the disk drives 14 are polled in parallel. Considering therefore one of the disk drives 14 and recognizing that the operation described below occurs concurrently for all disk drives 14 , the diagnostic section 20 during each polling event, here once every 500 milliseconds, for example, determines whether such polled disk drive 14 has placed itself in a bypass condition by reading the bit register 22 therein.
Thus, considering one of the polling events, the process determines whether the polled disk drive 14 has placed itself in a bypass condition (i.e., requested to be taken offline), Step 202 , by determining whether the bit register 22 in such disk drive 14 has been set. If the bit is set, the process logs a message indicating that the drive has requested to be bypassed, Step 204 , and saves the current timestamp and increments a count indicating the number of times the drive has placed itself in a bypass condition, Step 206 . The process determines whether the drive should be kept removed, Step 208 , by determining whether within a 24 hour period it already placed itself in a bypass condition. If so, the drive is kept removed as a declared unstable drive, Step 210 . If not, the drive is put into the probation state and a timer is started, Step 210 .
If the drive has not placed itself in a bypass condition, it is determined whether the drive is requesting to be brought online, Step 212 . If not, the event is complete with respect the drive, Step 214 . If so, the process logs a message indicating that the drive has requested to be brought back online, Step 216 . The process determines whether the drive can be brought back online, Step 218 , by determining whether the drive has been declared unstable (because more than once within a 24 hour period it requested to be bypassed). If not, the drive is kept removed as a declared unstable drive, Step 220 . If so, it is determined whether the drive's request to be brought back online is prior to expiration of a probation period, Step 222 . If so, the probation period timer is cancelled, the drive is brought online, and its sectors are rebuilt as necessary according to sector tracking during probation, Step 224 . Otherwise, the drive is brought online through normal processes (including full drive rebuilding if necessary), Step 226 .
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. | Storage stability is managed. It is detected that a disk drive is requesting to be taken offline. The disk drive is begun to be treated as being in a probation state. If within an acceptable period of time the disk drive requests to be put back online, treatment of the disk drive as being in a probation state is stopped, and only any portions of the disk drive data that were the subject of write requests involving the disk drive while the disk drive was being treated as being in a probation state are rebuilt. | 6 |
BACKGROUND OF THE INVENTION
1. Field of the Invention
The present invention relates to an approximately 90K-class (critical temperature Tc=approx. 90 degrees Kelvin) oxide superconducting material and a method of producing the same.
2. Description of the Related Art
The conventional method of raising the critical current density (Jc) of oxide superconducting materials is to establish pinning sites in REBa 2 Cu 3 O 7−x (superconducting phase; abbreviated: 123 phase) by dispersion of about 1-micron particles of RE 2 BaCuO 5 (211) or RE 4 Ba 2 Cu 2 O 10 (422). (RE in the foregoing notations designates one or a combination of two or more rare earth elements including Y.) It is known that 211 can be refined to around 1 micron by addition of Pt or Rh and that 422 can be refined to about the same level by addition of Ce. It is also known that a portion of the added Ce forms fine CeBaO 3 of a particle size of 1 micron or less that disperses into the superconducting phase.
JP-A-(unexamined published Japanese patent application)4-16511 teaches a structure having BaMO 3 (M representing Zr, Sn, Ce or Ti) finely dispersed together with 211 in stacked plate-like 123 phase. Materials having this structure are produced in a temperature gradient. JPA-5-279033, JP-A-5-286719, JP-A-6-1609 teach methods of producing superconductors in which 211 is finely dispersed by adding cerium oxide. They also teach structures having cerium oxide finely dispersed in 123 phase together with 211 and a noble metal such as silver. JP-A-5-58626 describes a superconductor having 211 finely dispersed in 123 phase containing Ce and method of producing the superconductor and teaches that addition of Ce enables fine dispersion of 211 by suppressing its agglomeration and enlargement.
From the viewpoint of achieving high Jc, it is preferable to introduce a large amount of fine non-superconducting particles and other pinning centers in the 123 phase. While 211 and 422 are currently the main non-superconducting phases used to produce pinning sites, the CeBaO 3 , SnBaO etc. taught in the foregoing literature also contribute to the pinning site formation, although at a lower rate than 211. The development of still other new substances capable of forming pinning sites is a challenge that demands attention.
SUMMARY OF THE INVENTION
That CeBaO 3 , a Ce—Ba—O system compound, is capable of forming pinning sites was thus known in the prior art. Now, the present inventors have discovered that particles composed of Ce, Ba, Cu and O (hereinafter called Ce—Ba—Cu—O system particles) constitute a new class of pinning site forming materials. They also discovered that when the particles are given a composition of Ce x Ba y Cu z O w , their effect is enhanced in the composition range of 2.4≦x≦3.6, 2.4≦y≦3.6, 0.8≦z≦1.2, 8≦w≦12. They further discovered that when the particle composition includes Ce 3 Ba 3 CuO 10 , the particles particularly enhance Jc by dispersing into the superconducting phase as submicron-diameter particles to become still more effective pinning sites. They additionally found that the Ce—Ba—Cu—O system particles coexist with 211 and 422 in the 123 phase.
When the Ce x Ba y Cu z O w content is too large, critical temperature and Jc decrease rather than increase because a portion of the Ce disperses in the 123 phase. The content is therefore preferably 15 mass % or less, more preferably 1-10 mass %.
The inventors also discovered that the Ce—Ba—Cu—O system particles can coexist with 211, 422 and 123 phases containing Pt, Rh or Ag. When the Pt content is less than 0.05 mass %, 211 is not refined, and when it is greater than 2.0 mass %, the addition efficacy decreases because the excess Pt forms many extraneous phases. The Pt content is therefore preferably 0.05-2.0 mass %, more preferably 0.3-0.6 mass %. When the Rh content is less than 0.01 mass %, 211 is not refined, and when it is greater than 1.0 mass %, the addition efficacy decreases because the excess Rh forms many extraneous phases. The Rh content is therefore preferably 0.01-1.0 mass %, more preferably 0.1-0.3 mass %. When Ag is added, about 0.1 mm-diameter Ag particles precipitate into the 123 phase to enhance the mechanical strength. When the amount of Ag added is less than 5 mass %, Ag particles do not precipitate, and when it is greater than 20 mass %, a tendency to inhibit crystal growth of the 123 phase arises. The amount of Ag addition is therefore limited to 5-20 mass %, more preferably 10-15 mass %.
The inventors discovered a method of producing a material containing effectively dispersed Ce x Ba y Cu z O w by mixing Ce x Ba y Cu z O w with a starting material powder containing RE (RE designating one or a combination of two or more rare earth elements including Y), Ba, Cu and O. When a powder compact formed by compacting the mixed powder is placed in an oxidizing atmosphere in the temperature range of 850-1,250° C., it assumes a semi-molten state in which 211 or 442 coexists with a liquid phase. When the compact is heat-treated in the atmosphere, it assumes a semi-molten state at 850-1,250° C. The 123 phase grows while incorporating Ce x Ba y Cu z O w to provide a 123 phase containing pinning sites of Ce x Ba y Cu z O w and 211 or 422 by carrying out slow cooling from the above described semi-molten state to a temperature range at which a 123 phase grows as a crystal, or slow cooling or maintaining an isothermal temperature in a temperature range for growing a 123 phase to crystallize.
Preferably, slow cooling or maintaining an isothermal temperature is carried out from a starting temperature for growing a 123 phase crystallization (Tp: peritectic temperature) to Tp-30° C. This method can provide a material containing effectively dispersed Ce x Ba y Cu O w because the Ce x Ba y Cu z O w remains in the material without decomposing during processing.
A material containing dispersed Ce 3 Ba 3 CuO 10 can be obtained by adding Ce 3 Ba 3 CuO 10 to a starting material powder containing RE, BA, Cu and O.
BRIEF DESCRIPTION OF THE DRAWING
FIG. 1 is a diagram schematically illustrating the structure of an oxide superconducting material wherein both Ce 3 Ba 3 CuO 10 particles and 211 are dispersed.
DESCRIPTION OF THE PREFERRED EMBODIMENTS
The present invention will now be explained in further detail with reference specific examples.
EXAMPLE 1
Y 2 O 3 , BaO 2 and CuO starting material powders were mixed at a mole ratio of the metallic elements (Y:Ba:Cu) of (13:17:24). The mixed powders were added with 2.0 mass % of Ce 3 Ba 3 CuO 10 powder and 0.3 mass % of Pt and the result was mixed to prepare a mixed starting material powder. The starting material powder was calcined in a stream of oxygen at 900° C. The calcined powder was formed into a disk-shaped compact measuring 30mm in diameter and 20mm in thickness by compression at 196 MPa using a rubber press.
The compact was heated to 1,150° C. in the atmosphere over 8 hours and thereafter held at this temperature for 1 hour. Then, at a temperature of 1,040° C., a Nd-system seed crystal was placed with its c-axis substantially aligned with a line normal to the disk surface. Next, crystal growth was effected by first lowering the temperature to 1,005° C. over 30 minutes and then conducting gradual cooling to 980° C. over 120 hours. This was followed by cooling to room temperature over 24 hours. An approximately 15 mm-thick bulk was obtained from the resulting cylindrical bulk material by slicing off the opposite end faces and removing the surface layer. The result was subjected to oxygen enrichment by heating the bulk to 500° C. in a stream of oxygen over 24 hours, gradually cooling it from 500° C. to 350° C. over 100 hours and then cooling it from 350° C. to normal room temperature over 10 hours.
A single crystal having the same crystal orientation as the seed crystal was obtained. The c-axis of the single crystal substantially coincided with a line normal to the disk surface. The critical current density was measured using a sample vibrating type flux meter and found to be 3.5×10 4 (A/cm 2 ) at 77K, 1 T (c-axis and magnetic field parallel). By observation with a transmission electron microscope, the structure was found to consist of 0.2-1.0 micron-diameter particles dispersed together with 211 in a 123 phase. The structure is shown schematically in FIG. 1. The particles were ascertained to be Ce 3 Ba 3 CuO 10 by energy dispersive spectroscopy (EDS).
As a comparative example, a cylindrical bulk material was prepared in the same manner as described above except that no Ce 3 Ba 3 CuO 10 was added. The crystal obtained had a critical current density of 2.8×10 4 (A/cm 2 ) at 77K, 1T (c-axis and magnetic field parallel).
The material according to the invention was thus clearly superior to that of the comparative example.
EXAMPLE 2
Dy 2 O 3 , BaO 2 and CuO starting material powders were mixed at a mole ratio of the metallic elements (Dy:Ba:Cu) of (13:17:24) to prepare a mixed starting material powder. CeO 2 , BaO 2 and CuO powders were mixed at a mole ratio of the metallic elements (Ce:Ba:Cu) of (3:2:1) and the mixed powders were calcined in oxygen at 900° C. for 8 hours to prepare a Ce—Ba—Cu—O system additive. The mixed starting material powder was added with 2.0 mass % of the Ce—Ba—Cu—O system additive and 0.3 mass % of Pt and the result was mixed to prepare a starting material powder. The starting material powder was calcined in a stream of oxygen at 900° C. The calcined powder was formed into a disk-shaped compact measuring 30 mm in diameter and 20 mm in thickness by compression at 196 MPa using a rubber press.
The compact was heated to 1,150° C. in the atmosphere over 8 hours and thereafter held at this temperature for 1 hour. Then, at a temperature of 1,040° C., a Nd-system seed crystal was placed with its c-axis substantially aligned with a line normal to the disk surface. Next, crystal growth was effected by first lowering the temperature to 1,010° C. over 30 minutes and then conducting gradual cooling to 985° C. over 100 hours. This was followed by cooling to room temperature over 24 hours. An approximately 15 mm-thick bulk was obtained from the resulting cylindrical bulk material by slicing off the opposite end faces and removing the surface layer. The result was subjected to oxygen enrichment by heating the bulk to 500° C. in a stream of oxygen over 24 hours, gradually cooling it from 500° C. to 350° C. over 100 hours and then cooling it from 350° C. to normal room temperature over 10 hours.
A single crystal having the same crystal orientation as the seed crystal was obtained. The c-axis of the single crystal substantially coincided with a line normal to the disk surface. The critical current density was measured using a sample vibrating type flux meter and found to be 3.1×10 4 (A/cm 2 ) at 77K, 1 T (c-axis and magnetic field parallel). By observation with a transmission electron microscope, the structure was found to consist of 0.2-1.0micron-diameter Ce—Ba—Cu—O system particles dispersed together with 211.
As a comparative example, a cylindrical bulk material was prepared in the same manner as described above except that no Ce—Ba—Cu—O system additive was added. The crystal obtained had a critical current density of 2.7×10 4 (A/cm 2 ) at 77K, 1T (c-axis and magnetic field parallel).
The material according to the invention having a structure including dispersed Ce—Ba—Cu—O system particles was thus clearly superior to that of the comparative example.
EXAMPLE 3
Er 2 O 3 , BaO 2 and CuO starting material powders were mixed at a mole ratio of the metallic elements (Er:Ba:Cu) of (13:17:24) to prepare a mixed starting material powder. CeO 2 , BaO 2 and CuO powders were mixed at a mole ratio of the metallic elements (Ce:Ba:Cu) of (1:1:1) and the mixed powders were calcined in oxygen at 920° C. for 8 hours to prepare a Ce—Ba—Cu—O system additive. The mixed starting material powder was added with 2.0 mass % of the Ce—Ba—Cu—O system additive and 0.3 mass % of Pt and the result was mixed to prepare a starting material powder. The starting material powder was calcined in a stream of oxygen at 900° C. The calcined powder was formed into a disk-shaped compact measuring 30 mm in diameter and 20 mm in thickness by compression at 196 MPa using a rubber press.
The compact was heated to 1,150° C. in the atmosphere over 8 hours and thereafter held at this temperature for 1 hour. Then, at a temperature of 1,040° C., a Nd-system seed crystal was placed with its c-axis substantially aligned with a line normal to the disk surface. Next, crystal growth was effected by first lowering the temperature to 995° C. over 30 minutes and then conducting gradual cooling to 975° C. over 130 hours. This was followed by cooling to room temperature over 24 hours. An approximately 15 mm thick bulk was obtained from the resulting cylindrical bulk material by slicing off the opposite end faces and removing the surface layer. The result was subjected to oxygen enrichment by heating the bulk to 500° C. in a stream of oxygen over 24 hours, gradually cooling it from 500° C. to 350° C. over 100 hours and then cooling it from 350° C. to normal room temperature over 10 hours.
A single crystal having the same crystal orientation as the seed crystal was obtained. The c-axis of the single crystal substantially coincided with a line normal to the disk surface. The critical current density was measured using a sample vibrating type flux meter and found to be 3.1×10 4 (A/cm 2 ) at 77K, 1 T (c-axis and magnetic field parallel). By observation with a transmission electron microscope, the structure was found to consist of 0.2-1.0 micron-diameter Ce—Ba—Cu—O system particles dispersed together with 211.
As a comparative example, a cylindrical bulk material was prepared in the same manner as described above except that no Ce—Ba—Cu—O system additive was added. The crystal obtained had a critical current density of 2.7×10 4 (A/cm 2 ) at 77K, 1 T (c-axis and magnetic field parallel).
The material according to the invention having a structure including dispersed Ce—Ba—Cu—O system particles was thus clearly superior to that of the comparative example.
EXAMPLE 4
Nd 2 O 3 , BaO 2 and CuO starting material powders were mixed at a mole ratio of the metallic elements (Nd:Ba:Cu) of (12:16:23). The mixed powders were added with 4.0 mass % of Ce 3 Ba 3 CuO 10 powder and 10 mass % of Ag and the result was mixed to prepare a mixed starting material powder. The starting material powder was calcined in a stream of oxygen at 900° C. The calcined powder was formed into a disk-shaped compact measuring 30 mm in diameter and 20 mm in thickness by compression at 196 MPa using a rubber press.
The compact was heated to 1,150° C. in argon containing 0.01 mol % of oxygen over 8 hours and thereafter held at this temperature for 0.5 hour. Then, at a temperature of 1,040° C., a Nd-system seed crystal was placed with its c-axis substantially aligned with a line normal to the disk surface. Next, crystal growth was effected by first lowering the temperature to 1,010° C. over 30 minutes and then conducting gradual cooling to 970° C. over 100 hours. This was followed by cooling to room temperature over 24 hours. An approximately 15 mm-thick bulk was obtained from the resulting cylindrical bulk material by slicing off the opposite end faces and removing the surface layer. The result was subjected to oxygen enrichment by heating the bulk to 400° C. in a stream of oxygen over 24 hours, gradually cooling it from 400° C. to 250° C. over 100 hours and then cooling it from 250° C. to normal room temperature over 10 hours.
A single crystal having the same crystal orientation as the seed crystal was obtained. The c-axis of the single crystal substantially coincided with a line normal to the disk surface. The critical current density was measured and found to be 3.5×10 4 (A/cm 2 ) at 77K, 1 T (c-axis and magnetic field parallel). By observation with a transmission electron microscope, the structure was found to consist of 0.2-1.0 micron-diameter Ce—Ba—Cu—O system particles finely dispersed together with 422. The particles were ascertained to be Ce 3 Ba 3 CuO 10 by EDS.
The superiority of the material according to the invention was thus ascertained.
The oxide superconducting material according to the present invention excels in Jc property and can be expected to make a considerable contribution to industry through application to magnetic levitation systems and magnets. | An oxide superconducting material includes a REBa 2 Cu 3 O 7−x phase (RE designating one or a combination of two or more rare earth elements including Y), particles composed of Ce, Ba, Cu and O dispersed therein, and RE 2 BaCuO 5 or RE 4 Ba 2 Cu 2 O 10 dispersed therein. A method is provided for producing the superconducting material from a mixed powder obtained by adding a Ce—Ba—Cu—O system additive to a starting material powder containing RE, Ba, Cu and O. | 2 |
BACKGROUND OF THE INVENTION
[0001] 1. Field of the Invention
[0002] The present invention relates to a chip package technology. More particularly, the present invention relates to a chip package structure and a method for fabricating thin-type reversible substrate.
[0003] 2. Description of the Prior Art
[0004] Along with the rapid progress of the computer and internet communication, the semiconductor products need to be multi-functional, portable, light, thin and small-sized to satisfy the customers' demand. Therefore, the industry of chip package has to develop towards the high accurate processes to comply with the requirements of high-power, high-density, lightness, thinness, compactness and mini-size. In order to fabricate thinner and lighter substrate, the package fabricating process must be complicated to meet the product of requirement but the complicated process may lead to higher damage rate.
SUMMARY OF THE INVENTION
[0005] According to the issue mentioned previously, the present invention provides a chip package structure and its fabrication method to improve the mentioned issue.
[0006] One object of the present invention is to provide a chip package structure and its fabrication method with a protective layer directly set on a metal layer and covered the chips and the conductive connecting structures, so as to not only promote the reliability but also reduce the production cost.
[0007] Another object of the present invention is to provide a chip package structure and its fabrication method which utilize a carrier for support to make the package fabrication method easier than the conventional method. Otherwise, the users may fabricate the structure of the present invention based on the present flow so that the fabrication yield may be increased.
[0008] Another object of the present invention is to provide a chip package structure and its fabrication method which utilize the carrier for support so that the thinner and lighter substrate may be fabricated to meet the present requirement of the semiconductor technology.
[0009] Another object of the present invention is to provide a chip package structure and its fabrication method which utilize a carrier for support. As the carrier is removed, the remainder substrate structure may be fabricated as a reversible substrate so as to electrically connect to other electrical devices conveniently.
[0010] Further another object of the present invention is to provide a chip package structure and its fabrication method that may be implemented by existing fabrication process of the package manufacturing. Hence, the additional equipments or fabrication processes are unneeded so as to lower the package cost.
[0011] To achieve the objects mentioned above, one embodiment of the present invention is to provide a method for fabricating a chip package structure, which includes following steps: providing a carrier having an insulating layer set thereon and a conductive layer set on a surface of the insulating layer; removing a portion of the conductive layer and a portion of the insulating layer to expose a portion of the carrier; forming a first metal layer on the conductive layer, the insulating layer and an exposed portion of the carrier; removing a portion of the first metal layer and a portion of the conductive layer to expose a portion of the insulating layer; forming a second metal layer on a portion of the first metal layer; arranging at least a chip on at least a portion of the first metal layer; electrically connecting the chip to at least any one of the first metal layer and the second metal layer; forming a protective layer to cover the chip; and removing the carrier.
[0012] According to another embodiment of the present invention is to provide a chip package structure, which includes: an insulating layer; a conductive layer arranged on a portion of the insulating layer; a first metal layer arranged on a portion of the conductive layer and part of an exposed portion of the insulating layer; a second metal layer arranged on a portion of the first metal layer; at least a chip arranged on at least any one of the first metal layer and the second metal layer; a conductive connecting structure electrically connected the chip to at least any one of the first metal layer and the second metal layer; and a protective layer directly covered an exposed portion of the first metal layer, the second metal layer, the chip, the conductive connecting structure, an exposed portion of the conductive layer and the exposed portion of the insulating layer.
[0013] Other advantages of the present invention will become apparent from the following description taken in conjunction with the accompanying drawings wherein are set forth, by way of illustration and example, certain embodiments of the present invention.
BRIEF DESCRIPTION OF THE DRAWINGS
[0014] The foregoing aspects and many of the accompanying advantages of this invention will become more readily appreciated as the same becomes better understood by reference to the following detailed description, when taken in conjunction with the accompanying drawings, wherein:
[0015] From FIG. 1 to FIG. 12 are cross-section view schematic diagrams of the method for fabricating the chip package structure in accordance with one embodiment of the present invention.
DETAILED DESCRIPTION OF THE INVENTION
[0016] The detailed explanation of the present invention is described as following. The described preferred embodiments are presented for purposes of illustrations and description, and they are not intended to limit the scope of the present invention.
[0017] Referring to FIG. 1 , First, a carrier 10 has an insulating layer 20 set thereon and a conductive layer 30 arranged on the insulating layer 20 . In one embodiment, the insulating layer 20 and the conductive layer 30 may be one-piece formed commodity, such as the resin coated copper foil (RCC). In another embodiment, the carrier 10 provided with the insulating layer 20 and the conductive layer 30 may be formed in three steps. Foremost, the insulating layer 20 , such as a glass fiber prepreg, is set on the carrier 10 , such as a metal, a glass, a ceramics, and a polymeric carrier, by using conventional suitable method of pasting, printing, spray coating, spin coating or laminating. Next, the conductive layer 30 , for instance a gold foil, is formed on the insulating layer 20 by using the pasting, printing, sputtering, laminating, electroless plating or electroplating. In one embodiment, the surface of the conductive layer 30 may also be processed with conventional rough methods of brown-oxide procedure, black-oxide procedure, microetch procedure, scrubbing procedure, or sand blasting procedure.
[0018] Next, refer to FIG. 2A , a portion of the conductive layer 30 is removed to form plural first patterned fillisters 40 as a mask for removing insulating layer 20 . In one embodiment, the step of removing the conductive layer 30 may be undertaken with the conventional lithography procedure, photo-etching procedure or laser cutting eneraving procedure. After, a portion of the insulating layer 20 may be removed at part of those first patterned fillisters 40 to form plural second patterned fillisters 42 to expose a portion of the carrier 10 , wherein the insulating layer 20 may be removed by utilizing hole drilling procedure, depth control procedure, laser procedure or plasma method, as shown in FIG. 2B .
[0019] Next, a first metal layer 50 is formed on the conductive layer 30 , the insulating layer 20 and an exposed portion of the carrier 10 , as shown in FIG. 3 . In one embodiment, the first metal layer 50 is made of copper material by sputtering, evaporating, electroless plating or electroplating for conducting each layer. Besides, before the first metal layer 50 is formed, electroless copper (plate through hole, PTH) and/or black-hole etc. procedures may be utilized to increase the absorbability between the first metal layer 50 and the insulating layer 20 . Furthermore, the surface of the first metal layer 50 may be processed with the conventional rough methods of brown-oxide, black-oxide, microetch, scrubbing, and sand blasting. In another embodiment, those second pattern fillisters 42 further may be filled with the first metal layer 50 .
[0020] Continually, refer to FIG. 4 , a portion of the first metal layer 50 and part of the conductive layer 30 may be removed to expose a portion of the insulating layer 20 to form a plurality of third patterned fillisters 44 . In one embodiment, the methods of removing the first metal layer 50 and the conductive layer 30 may be lithography procedure, photo-etching procedure or laser cutting eneraving procedure. Those patterned fillisters are used for external layout, but it is understood that those patterned fillisters in the present invention may not be limited for external layout. After, such as shown in FIG. 5 , a second metal layer 52 is formed on a portion of the first metal layer 50 as electrically connecting contact. In one embodiment, the second metal layer 52 is fabricated with printing procedure, sputtering procedure, evaporating procedure, electroless plating procedure or electroplating procedure. Next, the second metal layer 52 is made of gold, silver, tin, aluminum, electroless nickel and immersion gold, immersion silver, immersion tin, electroless nickel and immersion gold, electroless silver plating and electroless tin plating. Moreover, the surface of the second metal layer 52 may be fabricated with the conventional rough methods of brown-oxide procedure, black-oxide procedure, microetch procedure, scrubbing procedure, and sand blasting procedure.
[0021] Further, please refer to FIG. 6 , a suitable and conventional way, such as a die bonding process, is utilized to arrange one or plural chips on at least any one of the first metal layer 50 and the second metal layer 52 , wherein those chips may have different functions, such as chip 60 and chip 62 , and the active surface of those chips 60 , 62 faces upward. In one embodiment, those chip 60 and chip 62 further comprise a conductive connecting structure set thereon, for instance, the conductive connecting structure may be bonding pad (not shown in figure). Continually, refer to FIG. 7 , in one embodiment, the conductive connecting structure, such as bonding wire 70 and bonding wire 72 , are electrically connecting these chip 60 , 62 with at least any one of the first metal layer 50 and the second metal layer 52 . Ac cording to the above mentioned description, those chips 60 , 62 with identical function may electrically connect to different first metal layer 50 and the second metal layer 52 . Moreover, different chip 60 and chip 62 may electrically connect to different first metal layer 50 and second metal layer 52 to meet the needs of different package designs. There after, as shown in FIG. 8 , a molding procedure is sequentially undertaken. A protective layer 80 is fabricated to cover the chip 60 , 62 , bonding wire 70 , 72 , the first metal layer 50 , the second metal layer 52 , an exposed portion of the conductive layer 30 and the insulating layer 20 . Accordingly, one feature of the present invention is no photosensitive protective layer, such as a solder mask, set on the first metal layer 50 , the second metal layer 52 and the conductive layer 30 . The protective layer 80 directly touches the chip 60 , 62 , bonding wire 70 , 72 , the first metal layer 50 , the second metal layer 52 , the conductive layer 30 , and the insulating layer 20 . Such structure may be fabricated to overcome the efficiency issue caused by the photosensitive protective layer to not only improve the reliability but also simplify the procedure so as to lower the production cost.
[0022] Next, as shown in FIG. 9 and FIG. 10 , a suitable method is utilized to remove the carrier 10 and expose part of the first metal layer 50 . Subsequently, a conductive connecting structure 54 , such as a bump, is set on an exposed portion of the first metal layer 50 by using the surface mount technology (SMT) or electroplating technology so as to electrically connect with other electrical devices. Further, a plurality of the chip package structures is formed by dicing in accordance with a unit of each chip, such as shown in FIG. 11 and FIG. 12 . In one embodiment, the chip package structure fabricated according to the above-mentioned method of present invention may include a conductive layer arranged on an insulating layer, and the first metal layer arranged on part of the conductive layer and part of an exposed portion of the insulating layer. Moreover, a second metal layer is set on part of the first metal layer and at least a chip is set on at least any one of the first metal layer and the second metal layer. Continually, a conductive connecting structure, such as the bonding wire, etc., is arranged on at least any one of the first metal layer and the second metal layer. Finally, a protective layer is formed to cover the first metal layer, the second metal layer and an exposed portion of the conductive layer and the insulating layer.
[0023] To sum up the foregoing descriptions, the present invention provides a chip package structure and its fabrication method. A carrier is utilized for support so as to fabricate ultra thin substrate, and further the revisable substrate may be fabricated. Moreover, owing to the support of the carrier the process may be simplified. Further, the fabrication method of the invention may be processed by present PCB manufacturing process and additional equipments or fabricating processes are unneeded so as to lower the production cost of the substrate. Otherwise, the present structure differs from the conventional structure which is coated with the solder mask layer. The protective layer is formed to directly contact and cover the metal layer, the conductive layer, the insulating layer, those chips and the conductive connecting structure so as to not only improve the reliability but also lower the cost of the solder mask. The package manufacturers which fabricate the substrate of the invention don't need to purchase additional equipments or add other fabrication process. Hence, the thickness of the package structure may be reduced and the requirement of thin light-weight electrical device may be met to lower the overall package cost.
[0024] The foregoing descriptions of specific embodiments of the present invention have been presented for purposes of illustrations and description. They are not intended to be exclusive or to limit the invention to the precise forms disclosed, and obviously many modifications and variations are possible in light of the above teaching. The embodiments were chosen and described in order to best explain the principles of the invention and its practical application, to thereby enable others skilled in the art to best utilize the invention and various embodiments with various modifications as are suited to particular use contemplated. It is intended that the scope of the invention be defined by the claims appended hereto and their equivalents. | A chip package structure and its fabrication method are disclosed. Method of electrically connecting a chip with plural different metal layers is utilized to replace the conventional method of connecting identical metal layer merely. Besides, the method of a protective layer directly set on the metal layer to cover the chip and the conductive connecting structure is different from the general method of coating the solder mask on the metal layer. Moreover, a carrier utilized for support makes lighter and thinner substrate be fabricated. The fabrication method is utilized to manufacture by using the fabrication process of present package manufacturing. No additional equipments and fabrication processes are needed so that the PCB production flow may be simplified to reduce the package cost. | 7 |
RELATED APPLICATIONS
This application is a continuation-in-part application of U.S. application Ser. No. 09/678,452, filed Oct. 3, 2000, now abandoned.
FIELD OF THE INVENTION
The present invention relates to a pyrotechnic active material for producing infrared (IR) radiation.
BACKGROUND OF THE INVENTION
Hot bodies such as, for example, pyrotechnic flames emit visible light as well as infrared radiation. The radiation emission from hot bodies, such as pyrotechnic combustion products, is described by Planck's radiation law, which is shown in equation 1 hereinbelow. In accordance therewith, the total energy irradiated from a hot body per unit of surface area is proportional to the absolute temperature of the hot body. In addition, the emission maximum is also a function of temperature. The functional relationship is described by Wien's displacement law, which is shown in equation 2. E ( v ) = 8 π v 3 c 3 e ( h - v / λ kT ) - 1 ( 1 ) λ max T= 0.289779 cm.K −1 (2)
The military sector for combating aerial targets such as, for example, jet aircraft, helicopters and transport machines, involves the use of missiles which target on and track the IR-radiation emitted by the propulsion unit of the aerial target, primarily in the range of between 0.8 and 5 μm, by means of an infrared radiation-sensitive seeker head.
To provide a defense against missiles from such aerial targets, decoy bodies are used, which are pyrotechnic IR-radiating devices that imitate the IR-signature of the target.
In order to produce radiation in the wavelength range which imitates the IR-signature of the target, the requirement is for a flame having a temperature of at least greater than 1700 K so that a sufficient level of IR-radiation density can be generated (I 0.8-5 μm >0.2 kW.sr −1 .s −1 .cm 2 ). It will be appreciated, however, that pyrotechnic flames at that temperature generally provide very little IR-radiation. The deviation from Planck's law is to be attributed to the emissivity ε of the combustion products. Emissivity is a factor that describes the deviation of real radiating bodies from the ideal of the Planck's or black body. By definition, ε=1 applies to a black body. All real radiating bodies always have emissivity values of less than 1 and, in many cases, less than 0.5. With the exception of hot compressed gases which have ε-values greater than 0.9, typical reaction products of pyrotechnic reactions (MgO, KCI, Al 2 O 3 , etc.) have ε-values of between 0.05-0.2. For that reason, in the development of IR-active materials, attention has been already paid, at a very early stage, to providing products which have a high level of emissivity. Those substances with a high ε-value include, for example, carbon black (ε=0.85). Thus, conventional active materials for producing black body radiation in the IR-range comprise Magnesium/TEFLON®/VITON®-mixtures (MTV). TEFLONS is a material that comprises polytetrafluoroethylene; while VITON® is a fluoroelastomeric material. Those prior art compositions upon combustion in accordance with equation 3 predominantly yield magnesium fluoride and carbon black.
2 n Mg+(C 2 F 4 ) n →2 n MgF 2 +2 n C+ h.v (3)
The effectiveness of the MTV-containing decoy (i.e., flare) against IR-seeker heads is based on the high level of heat of formation of magnesium fluoride as well as on the high level of emissivity of carbon black produced (ε≈0.85) which, due to thermal excitation, has an almost black body-like emission
On a number of occasions, attempts have been made to increase the pointance of such MTV-flares. For that purpose, conventional MTV-compositions are provided with additives, such as titanium, zirconium and/or boron for increasing the mass consumption rate. The use of such additives in conventional MTV-flares is described, for example, in T. Kuwahara, T. Ochiai, Burning Rate of Mg&/TF Pyrolants, 18 th International Pyrotechnics Seminar, 1992, 539; and T. Kuwahara, S. Matsuo, N. Shinozaki, Combustion and Sensitivity Characteristics of Mg/TF Pyrolans, Propellants, Explosives Pyrotechnics, 22 (1997); 198-202.
The increase in the mass consumption rate m 1 means that it is possible to increase the radiance I λ (see equation 4).
I λ =E λ ·m i (4)
in which:
E λ =specific intensity [kJ.g −1 .sr −1 ]
m i =mass consumption rate [g.s −1 .cm −2 ]
I λ =pointance [kW.sr −1 .cm −2 ]
It will be appreciated, however, that these substances weaken the spectral intensity distribution to the detriment of the black body level insofar as selectively emitting oxidation products are formed.
SUMMARY OF THE INVENTION
An object of the present invention is to provide a pyrotechnic composition which, while retaining the known spectral characteristic of MTV decoys, has a substantially higher level of specific power.
Accordingly, pursuant to the present invention there is provided a pyrotechnic composition for producing IR-radiation which comprises, by weight, 10-72.5% of a poly-(carbon monofluoride) oxidation agent; 15-90% of a halophilic metallic fuel comprising a metal selected from the group consisting of magnesium, aluminum, titanium, zirconium, hafnium, calcium, beryllium boron and mixtures or alloys of said metals; 2.5 and 7.5% of an organic fluorine-bearing agent; and 0.1-5% of graphite. Note that the various components present in the pyrotechnic composition of the present invention add up to 100%.
The increase in power of the pyrotechnic composition of the present invention serves to simplify the manufacture of the munition. Now, the same level of power can be achieved with smaller amounts of pyrotechnics, whereby the risk of fire and explosion in manufacture is reduced. In spite of a reduction in the ingredients of the mixture by about 50%, the same amount of decoys of the same power can still be produced.
In addition by virtue of the reduction in the mass of the pyrotechnic payload, the munition becomes lighter, thereby also affording logistical advantages.
The present invention further prevents the formation of polyaromatic hydrocarbons (PAH) which are objectionable from the points of view of environment and human toxicology, as are produced in the combustion of MTV-flares.
The present invention is based on the consideration of deliberately and specifically producing upon combustion graphite, the substance with the highest level of emissivity (ε λ<5 μm =0.95), which can be excited by the heat of the pyrotechnic reaction to afford thermal radiation. Furthermore, in accordance with the present invention, the reaction heat is markedly increased in comparison with the prior art systems. This can be affected by the use of substances with a lower level of molar enthalpy of formation, in comparison with TEFLON®.
DETAILED DESCRIPTION OF THE INVENTION
Various prior art approaches for the pyrotechnic production of graphite make use either of incomplete combustion of aromatic compounds (anthracene, naphthalene or their derivatives or homologues thereof) or the thermal decomposition of intercalation compounds of graphite (these are intercalation compounds in which the spaces between the individual graphite lattices can be occupied by foreign atoms or molecules, for example, anions or cations). Incomplete combustion of aromatic hydrocarbons has already found its way into the production of pyrotechnic black body radiator, see, for example, U.S. Pat. No. 5,834,680. It will be appreciated, however, that in the case of U.S. Pat. No. 5,834,680, only graphite-like pyrolysis products are formed, which suffer from surface contamination by low-molecular PAHs, for which reason their emissivity is markedly below that of graphite; in addition the PAH adhesions represent a toxicological potential which is not to be underestimated. The thermal decomposition of intercalation compounds of graphite has only been proposed for producing dipole aerosols for attenuating electromagnetic radiation, see, for example, DE 43 37 9071 C1.
In both U.S. Pat. No. 5,834,680 and DE 43 37 9071 C1, the graphite precursor, that is to say the aromatic (anthracene or decacyclene, respectively) or the intercalation compound of graphite does not contribute to the reaction heat, but rather acts as an endergonic additive which lowers the flame temperature (see U.S. Pat. No. 5,834,680, column 3, lines 23-25 and column 5, lines 18-21).
It has now been found by the present applicant that graphite can be produced by the reduction of poly-(carbon monofluoride) (PMF) by means of high-energy halophilic fuels. In accordance with the present invention, the term “PMF” denotes a polymeric graphite fluoride material that contains covalent bonds between the carbon and fluoride atoms, which has a quasi-infinite two-dimensional stratified structure. The term “PMF” may be interchangeably used with the term “graphite fluorinated polymer”. Unlike the intercalation compounds of graphite, which are described and claimed in DE 43 37 9071 C1, there are true covalent bonds between the carbon and the fluorine atoms in the PMF material employed in the present invention. Therefore the formation of graphite by reductive elimination of the fluorine atoms in a PMF material is already favored just in relation to entropy, in comparison with the formation from condensed aromatics. In addition, the conversion of a formerly saturated system into an aromatic system (“graphen”) should represent a thermodynamic advantage.
In accordance with the present invention, compositions are produced from poly-(carbon monofluoride) which contains a repeating unit of the formula ((—CF x —)n) with a molar proportion of fluorine represented by x of between 0.6 to 1.2, preferably x is between 1 and 1.2 or x is less than 1.1; and n is the number of repeating CF x moieties present in the polymeric material. The value of n is dependent upon the dimensions of the CF particles and the desired molecular weight of the polymeric material. The poly-(carbon monofluoride) employed in the present invention may include PMF materials having CAS Registration Nos. [51311-17-2] (PMF material where x is between 1 and 1.2) and [11113-63-6] (which is a PMF material where x less than 1.1). The particle sizes of the PMF material may vary, but typically, the particles sizes are less than 50 μm. The PMF material is present in the pyrotechnic composition of the present invention in an amount, based by weight, of from 10-72.5%, with an amount of from 20-70% being more highly preferred.
In addition to the PMF material which is used as an oxidation agent, the pyrotechnic composition of the present invention also includes as a halophilic metallic fuel which contains a metal selected from the group consisting of magnesium, aluminum, titanium, zirconium, haffium, calcium, beryllium, boron and mixtures thereof including alloys of the aforementioned metals. The halophilic fuel preferably contains magnesium metal. The halophilic fuel is present in the pyrotechnic composition of the present invention in an amount, based by weight, of 15-90%, with an amount of from 40-70% being more highly preferred.
In accordance with the present invention, the pyrotechnic composition of the present invention further includes an organic fluorine-bearing binding agent. Specifically, the binding agent used is a combustion-supporting fluorine-bearing elastomer based on hexafluoropropylene-vinylidene difluoride copolymer, for example Fluorel FC 2175™, in proportions by mass of between 2.5 and 7.5%. Other organic fluorine-bearing binding agents that can be employed in the present invention are a series of fluoroelastomers based on the copolymer of vinylidene fluoride and hexafluoropropylene with the repeating structure —CF 2 —CH 2 —CF 2 —CF(CF 3 )— which are sold under the tradename known as VITON®.
To reduce the electrostatics sensitivity of the pyrotechnic composition of the present invention, graphite powder is used, with a specific resistance of less than 7×10 −5 Ω.m −1 , in proportions by mass of from 0.1 to 5%.
In a preferred embodiment of the present invention, the pyrotechnic composition includes magnesium (Mg)/PMF/VITON® hereinafter referred to as the “MPV” system.
The advantages of the MPV system as well as the other pyrotechnic compositions of the present invention will become apparent upon comparison with the prior art magnesium/polytetrafluoroethylene/VITON® (hereinafter referred to as “MTV”) system; in the prior art MTV system the polytetrafluoroethylene is TEFLON®:
In the reaction of PMF with magnesium, magnesium fluoride and graphite are formed in accordance with equation 5:
n Mg+2(—CF—) n →n MgF 2 +2 n C graphite +h.v (5)
By virtue of the fluorine content of PMF, which is lower in comparison with PTFE, the ideal stoichiometry (see equation 3) occurs with a proportion of magnesium ξ(Mg) of 0.29, in comparison with TEFLON® in which the ideal stoichiometry (see equation 1) is reached with a proportion ξ(Mg) of 0.32. Because the heat of formation of PMF (−175 kJ.mol −1 ) is just one fifth as great as that of TEFLON® (−854 kJ.mol −1 ), the heat of the reaction of magnesium with PMF is consequently also considerably higher than the heat of reaction for the prior art magnesium/TEFLON® system.
The specific power (E 2-3 μm and E 3-5 μm ) of the MPV pyrotechnic composition of the present invention is correspondingly high. Admittedly the specific power, in the region ξ(Mg)>45, approaches the values for the mass consumption rate compared with prior art Mg/PTFE/VITON® compositions. The radiance I λ is therefore always higher by a factor of 10 in the case of Mg/PMF/VITON® compositions of the present invention, than in the case of the prior art Mg/PTFE/VITON® compositions of comparable composition.
Therefore, in relation to the proportion of magnesium, compositions produced in accordance with the present invention afford a level of radiance which is higher by a factor of 10 than the previously known prior art Mg/PTFE/VITON® compositions.
The example set out hereinafter is intended to illustrate the present invention without limiting it.
EXAMPLE 1
55 g of PMF was stirred into a suspension comprising 40 g of magnesium, 5 g VITON® and 1 g of graphite powder and 200 ml of acetone. The suspension was stirred in a flow of air until a crumbly material was produced. The solvent-moist granular material was passed through a sieve (2.5 mm mesh size) and dried at 40° C. in a flow of air for 5 hours. The granular material was processed with a 6 sec. holding time with 12 tonnes pressing pressure to give cylindrical pellets a mass of 40 g of a 25 mm caliber.
The results of radiometric measurement are set out in Table 1 with the measurement values for the Mg/PTFE/VITON® system which is of a similar composition; In the table, Sample 1 is representative of the present invention, whereas Sample 2 is a prior art pyrotechnic composition:
TABLE 1
1
2
Quotient 1/2
Magnesium
40%
40%
Poly-(carbon
55%
—
monofluoride)
Polytetrafluoroethylene
—
55%
VITON
5%
5%
Burning time [sec]
2.66
11.5
0.2
E 2-3 μm [kJ . g −1. sr −1 ]
0.170
0.100
1.7
E 3-5 μm [kJ . g −1. sr −1 ]
0.157
0.080
2.0
Mass Consumption
3.003
0.700
4.3
rate g . s −1. cm −2 ]
I 2-3 μm [kW . sr −1. cm −2 ]
0.511
0.070
7.3
I 3-5 μm [kW . sr −1. cm −2 ]
0.472
0.056
8.4
While the present invention has been particularly shown and described with respect to preferred embodiments thereof, it will be understood by those skilled in the art that the foregoing and other changes in forms and details may be made without departing from the spirit and scope of the present invention. It is therefore intended that the present invention not be limited to the exact forms and details described and illustrated, but fall within the scope of the appended claims. | A pyrotechnic active material for producing IR-radiation is proposed. An active material according to the invention contains fuel (preferably magnesium) which combines with fluorine in a strongly exergonic reaction (for example Li, Be, Mg, Ca, Sr, Ba, Ti, Zr, Hf, B, Al and alloys thereof) and poly-(carbon monofluoride) ((—CF x —)n) (x=0.6-1.2) as an oxidation agent. Compositions according to the invention further contain VITON® as a polymeric binding agent and graphite for reduction of the electrostatic sensitivity. A process for producing those compositions is also provided. | 8 |
this application claims the benefit of Provisional No. 60/103,465 filed Oct. 8, 1998.
REFERENCE
1986,792
9/30/32
M. B. Calvo
4,674,130
6/23/87
C. A. Coudron
2,782,418
2/26/57
A. Garson
2,504,534
4/18/50
H. E. Kephart Et Al
4,258,440
3/31/81
M. McGowan
3,116,491
1/7/64
R. E. Previdi Et Al
BACKGROUND OF THE INVENTION
1. Field of the Invention
This invention relates in general to women's wear apparel and more particularly concerns the construction and use of lingerie. This invention provides lingerie that also functions as lounge wear and has multiple uses and styles. It can function alone, and as an under or outer garment. This invention separates entirely, the front from the back and the adjustable shoulder straps detach from the front. This separation gives invention ability to interchange with multiple styles and colors of like invention to give wearer versatility.
2. Description of the Prior Art
The primary object of this invention is to provide a lingerie having detachable front & back panels and detachable straps. To provide the wearer with means for replacing front and back panels with others of different styles as requirement of lingerie for lounge wear arises.
Various types of detachable garments for people are known. Calvo, U.S. Pat. No. 1,986,792 discloses a bathing suit that detaches at the inside leg seams and side seams. Coudron, U.S. Pat. No. 4,674,130 discloses a children's sleeping bag that has a neck opening and a body insertion opening. Along the sides of the body insertion opening, hook and loom type adhesive strips are mounted along part of the length of the opening, so that arms & feet may extend through limb openings. Garson, U.S. Pat. No. 2,782,418 discloses a brassiere having detachable shoulder straps. Kephart Et Al, U.S. Pat. No. 2,504,534 discloses a bed jacket that detaches under arms and at sides. McGowan, U.S. Pat. No. 4,258,440 discloses shorts and top for the handicapped, which the shorts detach at the sides and the top detaches under the arms and at the sides. Previdi Et Al, U.S. Pat. No. 3,116,491 discloses a maternity blouse with interchange front panels, that detaches at the top of shoulders, down the front and at the sides. Top interchanges to accommodate women's size increase as baby grows.
Calvo, Coudron, Garson, Kephart, McGowan and Previdi provided garments for specific uses only.
SUMMARY OF THE INVENTION
This invention is primary for its construction, though it can be crafted in multiple styles from one structure, it attaches and detaches in one unique fashion.
Another object of this invention is to provide lingerie that will close with fasteners along the seams, as follows: one straight seam along each of the side lines of the garment from top to bottom, and a third seam at the crotch. The shoulder straps are permanently affixed to the back portion, female fasteners at the opposition end of straps that fastens to the male fastener affixed to the inside at top of front portion, which portions have arms and neck holes therein. Lingerie so made, the front and back portions are completely separable from each other.
Another object is to provide lingerie having plural parts that can be individually removed and laundered.
Still another object is to provide lingerie as described in which individual panels can be removed for changing color and style schemes of the lingerie at will. According to the fabric, design and finish, this invention can be either an undergarment or outer garment; it may be teddy, chemise or a nightgown. Along with being worn as lingerie, this invention can be wore as undergarment, suit top, lounge wear or bathing suit cover.
Another object is to provide a method of producing garments made with a minimum of material and labor and at the same time are constructed for a comfortable, smooth, accurate fit for women of various sizes, shapes and some disabilities.
A final object is to provide lingerie that is stylish and playfully fun. Though any fastener can be used, the use of hooks and looms and plastic snaps are chosen to give the full advantage of invention; thus providing the playful quick rip-away effect of the garment from the body. This invention is stylish and playful. This lingerie can be ripped apart from the front-to-back, from the top-to-the-bottom or from side-to-side, it's sexy, it's fun it's the Rippurr, the rip-away lingerie.
With these and related objects in view this invention consists in the constructing arrangement and combination of parts as will be more fully understood from the following description, which, however, is capable of expression other than as particularly described and illustrated without departing from the inventive concept.
BRIEF DESCRIPTION OF THE DRAWINGS
In the accompanying drawings, wherein an illustrative embodiment of the invention is disclosed,
FIG. 1 is a perspective view of the garment viewed from the rear right, showing the front portion coming together with the back portion at the hook and loom seam, and showing straps, one attached and one viewing how straps comes together with front portion.
FIG. 2 is a view of the panty portion of the garment in Figure with the back closure flap attached to the front flap.
FIG. 3 is a perspective front view of the garment embodying the invention.
FIG. 4 shows the shape of the panels and parts for one side of the front and back sections of garments, broken lines view panels for multiple styles.
FIG. 5 is a perspective view of garment showing multiple styles with broken lines.
FIG. 6 is a back elevational view, with the midriff cut away, of garment shown in FIG. 1, FIG. 3 and Panels f & g of FIG. 4 .
DESCRIPTION OF THE PREFERRED EMBODIMENT
In the drawing like reference numerals indicate like parts.
In the drawing reference numeral 1 indicates a teddy having a front 10 and back 11 and shoulder strap 12 , in its detached form viewing 13 (the female fastener) & 14 (the male fastener) and shoulder strap 15 , in its attached form viewing 16 (the female fastener) and 17 (the male fastener) together, at the top thereof and being cut away as indicted at 18 to accommodate the neck and head; and being cut away as indicated at 19 and 20 to form armholes for the arms and shoulders. The upper portion of this garment, though it can be formed in more than one piece as indicated in FIG. 4, 5 & 6 , is formed here in one piece, and at the bottom the crotch 21 & 22 and sides come together and form the leg areas 23 & 24 . The front and back portions of this lingerie are entirely independent and separable from each other. The front and back portion of the lingerie are fastened together by hook and loom fasteners 25 & 26 (shown), 27 & 28 (partially shown), 29 & 30 , 31 & 32 , 33 & 34 , 35 & 36 (partially shown in FIG. 4) along right and left sides, and at the crotch 21 & 22 (shown in FIG. 2 ), as will now be described.
Garment is conformed to fit body closely giving the wearer the option to wear this garment alone or under other garments such as a suit jacket, blouse or dress.
Drawing reference numeral 2 indicates the crotch 21 & 22 and legs 23 & 24 areas. The front crotch portion 21 viewing looms 21 a & 21 b (shown in FIGS. 4 & 6) and the back crotch portion 22 viewing hooks 22 a & 22 b (shown in FIGS. 4 & 6) are attached together to form the crotch area viewed in drawing reference numeral 1 and 3 .
Drawing reference numeral 3 is a perspective view of invention from front view.
Drawing reference numeral 4 indicates panels front 10 (inside of garment) with male fastener and with adhesive looms at side and crotch; and back 11 (right side of garment) with strap 12 in affixed form, with female fastener and adhesive hooks at side and crotch. Panels can be cut on fold for one front and one back portion or straight of grain for two front and two back portions. Front portion 10 , looms 25 , 27 , 29 (shown), 31 , 33 , 35 (not shown) and 21 a (shown) & 21 b (not shown); and shoulder straps male fasteners 14 (shown) & 17 (not shown) are all attached together with back portion 11 , hooks 26 , 28 , 30 (shown), 32 , 34 , 36 (not shown) and 22 a (shown) & 22 b (not shown); and shoulder straps 12 (shown) and 15 (not shown) and female fasteners 13 (shown) & 16 (not shown) form perspective view in drawings 1 , 3 , and 5 .
Be it understood that although FIGS. 1 & 3 front 10 and back 11 portions are viewing each as a single piece of fabric, portions may in fact be made up of sections which are stitched or otherwise attached together to obtain the exact shape and tailoring designed. Be it also understood that although the preferred use is hooks and looms for invention sides and crotch areas, any fastener that can be pulled apart may in fact be used to attach garment together.
Drawing reference 4 also indicates by broken line (for cut lines) that though invention body style is expendable to multiple interchangeable styles, the garment construction does not change. Adding panel 4 c to the bottom of panels front 10 and back 11 gives the style of a teddy with a skirt as indicated by broken lines in drawing 5 c . 4 d & 5 e cut short or long, changes garment to a chemise or gown as indicated by broken lines. 4 a cut away garment at midriff for 4 e & f and add elastic to waist of 4 f to form a camisole top and french-cut shorts as indicated in drawing 6 ; cutting bottoms with portion 4 c forms garment to boxer shorts as indicated in 5 d by broken lines in drawing 5 . Garment edges are completed with a rolled edge, giving a lettuce cut along bottom edges.
It is herein indicated that the present invention is particularly applicable to lingerie. However, it will be apparent that the same may be used in connection with lounge wear (long & short tops and bottoms), slips and other garments; therefore it is to be understood that its application to lingerie is illustrative only and is to be taken to comprehend any other garments on which the construction can be satisfactorily employed. The choice of hooks and looms and plastic snaps are used in this invention, providing garment with easy and quick detaching by simply pulling front or back or sides of garment away from body with a quick thrush, giving the sound of garment ripping thus giving invention the name of the Rippurr, the rip-away lingerie. | Conforming women under and/or outer garments made with loom fabrics and processed materials. Assembled with seams of hook and loom type adhesive at left and right sides of garment and crotch, and the top end is divided by two straps affixed to garment in the back and attaches to the front with fasteners providing shoulder straps, a head opening and two arm openings. | 0 |
BACKGROUND OF THE INVENTION
[0001] 1. Technical Field
[0002] The present invention is generally related to the field of integrated circuits and, more particularly, to a method and apparatus for cooling integrated circuits.
[0003] 2. Description of Related Art
[0004] The use of radio frequencies (RF) and microwave frequencies have been utilized for most of the 20 th century to provide communications. Early uses of RF and microwave technologies involved radio communications, both broadcast and two-way communication, and radar for detecting incoming aircraft. Much of this early technology was developed the 1940's to help in fighting World War II.
[0005] After the war, RF and microwave technologies were extended into other communication areas. Telephone companies used microwave technologies to carry voice communications across areas in which it was impractical to build transmission lines, such as, for example, in vary mountainous terrain. RF frequencies were also used by the emerging television industry to carry television broadcasts to peoples' homes where their television sets received the broadcast signal.
[0006] More recently, RF transmissions have been used to carry satellite signals, both for military and commercial use as well as, more recently, for delivering television content to subscriber's homes as well as access to the Internet. RF and microwave frequencies are also used to provide wireless (cellular) telephone services, these services include analog, digital and personal communication services (PCS).
[0007] The transmission capacity of an electronic communications through RF transmissions is determined by the range of the frequency signals (bandwidth), and the number of channels in the bandwidth. It is expressed in bits per second, bytes per second or in Hertz (cycles per second). As more and more information is being transmitted through RF circuits, a need for greater bandwidth has developed to handle this increase in information transmittal. However, the bandwidths and channel capacity of RF, cellular, and microwave systems are limited by the signal-to-noise (S/N) ratios of the amplification and filtering process within the system. One important method to increase the S/N ratios is to reduce the thermal noise by lowering the operating temperature of the circuits. Therefore, it would be desirable to have an apparatus, system, and method for cooling RF circuits such that the bandwidths and channel capacity of the RF circuits could be increased.
SUMMARY OF THE INVENTION
[0008] The present invention provides an apparatus for cooling an integrated circuit component, such as a field effect transistor circuit used in a radio frequency transistor or receiver. In one embodiment, the cooling apparatus includes a cold plate thermally coupled to the integrated circuit component, a thermoelectric cooler thermally coupled to the cold plate; and a hot plate thermally coupled to the thermoelectric cooler. Heat is removed from the integrated circuit component through the cold plate and transmitted to the hot plate through the thermoelectric cooler. The hot plate is located at a surface of an integrated circuit such that heat transmitted to it from the integrated circuit component is dissipated into the atmosphere surrounding the integrated circuit chip.
BRIEF DESCRIPTION OF THE DRAWINGS
[0009] The novel features believed characteristic of the invention are set forth in the appended claims. The invention itself, however, as well as a preferred mode of use, further objectives and advantages thereof, will best be understood by reference to the following detailed description of an illustrative embodiment when read in conjunction with the accompanying drawings, wherein:
[0010] FIGS. 1 A- 1 E depict circuit diagrams of examples of typical radio frequency (RF) circuits that benefit from cool operation;
[0011] [0011]FIG. 2 depicts a graph of a typical temperature dependency of the quality factor of on-chip spiral inductors;
[0012] [0012]FIG. 3 depicts a high-level block diagram of a Thermoelectric Cooling (TEC) device in accordance with the present invention;
[0013] [0013]FIG. 4 depicts a top planar view of direct coupled coolers for cooling IC RF circuits in accordance with the present invention;
[0014] [0014]FIG. 5 depicts a current-controlled thermoelectric cooler (TEC) circuit in accordance with the present invention;
[0015] FIGS. 6 A- 6 B depict top cut-away planar and cross-sectional views of a patterned cold plate for cooling RF IC circuits in accordance with the present invention;
[0016] FIGS. 7 A- 7 B depicts top cut-away planar and cross-sectional views illustrating direct thermal coupling of a cooler with the LNA/PA and body/substrate levels of an integrated circuit (IC) in accordance with the present invention;
[0017] [0017]FIG. 8 depicts a cross sectional view of an exemplary thermoelectric spot cooler fabricated over an RF CMOS IC in accordance with the present invention; and
[0018] [0018]FIG. 9 depicts a cross sectional view of an exemplary RF spiral inductor circuit wherein the thermoelectric cooler is incorporated in the passive inductor and the heat is rejected into the bulk substrate in accordance with the present invention.
DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENT
[0019] With reference now to the figures and, in particular, with reference to FIGS. 1 A- 1 E, circuit diagrams of examples of typical radio frequency (RF) circuits that benefit from cool operation are depicted. FIG. 1A depicts an example of a passive antenna system. FIG. 1B depicts an example of input low noise amplifiers (LNAs). FIG. 1C depicts an example of the mixer stages in an RF circuit. FIG. 1D depicts an example of a quadrature oscillator. FIG. 1E depicts an example of a power amplifier (PA) at the output. The channel selectivity of these circuits and the filters employed in the signal path are determined by the quality factor of the passive inductors and capacitors, and the thermal noise voltages in the transistors. Both the quality factor and thermal noise voltages are strongly dependent on the operating temperature.
[0020] With reference now to FIG. 2, a graph of a typical temperature dependency of the quality factor of on-chip spiral inductors is depicted. The graph depicted in FIG. 2 relates the quality factor of a 150×150 μm 2 3.1 nanoHenry (nH) spiral inductor coil implemented in the clock generator of a CMOS test chip versus the frequency of operation in gigahertz (GHz) for three temperatures. As shown in FIG. 2, the quality factor for the spiral inductor coil rises continuously as the temperature of the inductor is decreased for all frequencies of operation. For an inductor temperature of 100 degrees Celsius, the quality factor of the inductor coils is approximately in the range of 2-3 over the frequency range of 1.0 to 10.0 GHz. As the temperature of the inductor coils is decreased to 25 degrees Celsius, the quality factor increases to approximately 5.0 for the same frequency range. As the temperature of the inductor coils is further decreased to −123 degrees Celsius, the quality factor increases even further to approximately 15.0 to 18.0 over the same range of frequencies. Thus, a significant benefit is achieved by reducing the operating temperature of the inductive coils. Similar benefits in temperature reduction or achieved with other RF circuits.
[0021] The phase noise, L, of the oscillators are also directly affected by the operating temperature of the circuit. The temperature dependence of the phase noise of the oscillators are given by the following equation:
L { Δω } = kT · R · F · ( ω 0 Δω ) 2 P signal
[0022] where
[0023] R=effective resistance of the (LC) tank (temperature dependent)
[0024] ω 0 =center frequency of oscillation
[0025] Δω=frequency offset
[0026] F=term related to noise from active devices
[0027] P signal =power level of oscillation
[0028] T=the absolute operating temperature in kelvins
[0029] From this equation, it is evident that phase noise increases as the temperature of the oscillators increase. Therefore, it is beneficial to have an oscillator operating at lower temperatures to decrease the amount of phase noise.
[0030] With reference to FIG. 3, a high-level block diagram of a Thermoelectric Cooling (TEC) device 300 is depicted in accordance with the present invention. TEC device 300 is preferably connected to the integrated circuit device near the temperature sensitive element. Thermoelectric cooling, a well known principle, is based on the Peltier Effect, by which DC current from power source 302 is applied across two dissimilar materials causing heat to be absorbed at the junction of the two dissimilar materials. A typical thermoelectric cooling device utilizes p-type semiconductor 304 and n-type semiconductor 306 sandwiched between poor electrical conductors 308 that have good heat conducting properties.
[0031] As electrons move from p-type semiconductor 304 to n-type semiconductor 306 via electrical conductor 310 , the energy state of the electrons is raised due to heat energy absorbed from heat source 312 . This process has the effect of transferring heat energy from heat source 312 via electron flow through p-type semiconductor 304 and electrical conductor 310 to heat sink 316 . The electrons drop to a lower energy state in the electrical conductor 310 and release the heat energy.
[0032] With reference now to FIG. 4, a top planar view of direct coupled coolers for cooling IC RF circuits is depicted in accordance with the present invention. Integrated circuit 400 includes two coolers 404 and 406 thermally coupled to passive spiral coil 402 . Coolers 404 and 406 may be implemented as, for example, TEC device 300 in FIG. 3. In this embodiment, the cold plate of cooler 406 is coupled directly to one end of the passive spiral coils 402 using via structures 408 and 410 . Via structures 408 and 410 and lower level interconnect 414 are preferably thermally and electrically conductive copper composition. The cold plate of cooler 404 is directly thermally coupled to the other end 420 of spiral coil 402 , preferably also of a copper composition.
[0033] Portions of coolers 404 and 406 as well as the spiral coil 402 are constructed within the same layer of the integrated circuit 400 . The interconnect 414 is constructed in a lower layer of the integrated circuit 400 from that of the spiral coil 402 . Although depicted using two coolers 404 - 406 to cool spiral coil 402 , a single cooler could be utilized as well. However, the two coolers working in tandem provide greater cooling of the spiral coil 402 than would a single cooler and help reduce any thermal gradient between different sections of the spiral coil 402 .
[0034] Electrical isolation between cooler 406 and passive spiral coil 402 may be achieved by using current-mode circuits or by using ultra-thin dielectric passivation layers such as chemical vapor deposition (CVD) silicon dioxide or anodized aluminum. Anodization of aluminum is preferable to CVD silicon dioxide because 1-10 nanometer (nm) dielectric layers can be easily formed, and the thermal conductivity of alumina (aluminum oxide) is better than that of silicon dioxide.
[0035] With reference now to FIG. 5, a current-controlled thermoelectric cooler (TEC) circuit is depicted in accordance with the present invention. Current-controlled TEC circuit 500 is an example of a current-mode circuit which may be used in conjunction with direct-coupled coolers 400 in order to maintain electrical isolation of the coolers 404 - 406 from passive spiral coil 402 . Current-controlled TEC circuit 500 includes p-channel field effect transistors 502 - 506 , n-channel transistors 508 , inverter 510 , and 512 - 514 , and TEC 516 . TEC 516 has a hot end 518 for dissipating heat and a cold end 520 which is thermally coupled to the device to be cooled.
[0036] The gate of transistor 508 is coupled to a bias control voltage V bc as well as to the input of inverter 510 . The output of inverter 510 is coupled to the gate of transistor 506 . The drain of transistor 506 and the drain of transistor 508 are coupled to the source of transistor 512 and to the gates of transistors 512 - 514 , so that transistors 512 and 514 are in a current mirror configuration. The drains of transistors 512 - 514 are coupled to ground G nd . The source of transistor 514 is coupled to a second end of TEC 516 . Thus, current-controlled TEC circuit 500 maintains a constant current flow I 0 through TEC 516 based upon bias voltage V bc . Even if the cold end 520 of the TEC 516 is electrically connected to the device, by Kirchoff's law, there is no current flowing between the TEC 516 and the device. Thus the current-mode bias circuit 500 ensures electrical isolation for the TEC 516 .
[0037] With reference now to FIGS. 6A and 6B, FIG. 6A depicts a top planar view of a patterned cold plate in an integrated circuit chip for cooling RF IC circuits and FIG. 6B depicts a cross-sectional view of the section of the integrated circuit chip in accordance with the present invention. In this embodiment, as an alternative to using direct-coupled coolers as depicted in FIG. 4, a cold plate 602 is placed underneath the RF circuit 650 , such as, for example, one of the RF circuits depicted in FIGS. 1 - 5 . By placing cold plate 602 under the RF circuits 650 , large areas of inductors and capacitors within the RF circuit 650 are cooled. However, cold plate 602 is not physically in contact with any of the circuits within RF circuits 650 but is separated by an dielectric material 604 . Cold plate 602 is thermally coupled to the thermoelectric cooler 606 by via thermal conductor 608 .
[0038] If cold plate 602 is constructed from metal and is used under the inductors within the RF circuit 650 , then cold plate 602 is patterned to avoid the inducement of circulating eddy currents in the metal layer resulting from magnetic coupling with the inductors.
[0039] The integrated chip 600 may contain other areas other than the RF circuits 650 that do not generate an excessive amount of heat and do not need to be cooled. Thus, an efficiency in power savings is achieved by the present invention by spot cooling only the portions (i.e. RF circuits 650 ) of the integrated circuit 600 that generate significant heat and need to be cooled.
[0040] With reference now to FIGS. 7A and 7B, FIG. 7A depicts a top cut-away planar view illustrating direct thermal coupling of a TEC cooler through the body/substrate levels of an integrated circuit (IC) and FIG. 7B depicts a cross-sectional view along cut 750 of the direct thermal coupling of the TEC cooler through the body/substrate levels of an integrated circuit (IC) in accordance with the present invention. Vias 702 - 712 thermally couple a cold plate 762 of the IC 700 to the body/substrate level 752 of IC 700 . Body/substrate level 752 may contain low-noise amplifier circuits. The cold plate 762 of TEC cooler 714 is separated from the body/substrate level 752 of IC 700 by intervening metalization and/or oxide layers 754 .
[0041] An electrical conductor 760 couples the p-type impurity thermoelement 758 to the n-type impurity thermoelement 756 thus allowing current to flow from electrical conductor 768 through thermoelements 756 and 758 and out through electrical conductor 766 . An electrically isolating, thermally conducting hot plate 764 is in physical contact with electrical conductors 766 - 768 allowing heat to flow from thermoelements 756 - 758 into hot plate 764 , where the heat may then be dissipated.
[0042] With reference now to FIG. 8, a cross sectional view of an exemplary thermoelectric spot cooler fabricated over an RF CMOS IC is depicted in accordance with the present invention. In this exemplary embodiment, integrated circuit (IC) chip 800 includes a low noise amplifier (LNA) transistor 808 which is formed as a silicon-on-insulator (SOI) transistor in buried oxide 894 that lies above a silicon substrate 890 . A thermoelectric cooler (TEC) 832 is placed above LNA transistor 808 for cooling LNA transistor 808 . A second transistor 806 to provide a current source for TEC 832 is also formed as an SOI transistor in buried oxide 894 . A conductive via structure 810 through oxide layers 816 couples the drain 826 of transistor 806 to TEC 832 to provide current to the p-type 838 and n-type 840 semiconductor material of TEC 832 . P-type 838 and n-type 840 semiconductor areas provide a similar function as p-type semiconductor 304 and n-type semiconductor 306 in FIG. 3.
[0043] The heat spreader 830 , which acts as a heat sink, such as, for example, heat sink 316 in FIG. 3, for dissipating heat is thermally but not electrically coupled to the hot side element of TEC 832 through layer 834 . Layer 834 may be constructed, for example, from ultra-thin oxide or alumina. Heat spreader 830 could be coupled to layer 834 by solder.
[0044] N-type semiconductor 840 is thermally coupled to cold plate 828 through thin layer 836 . Layer 836 may also be constructed, for example, from ultra-thin oxide or alumina.
[0045] Cold plate 828 is thermally coupled to both the drain 824 and source 822 of transistor 808 through oxide layers 816 by using vias 814 and 812 respectively. Vias 812 and 814 , as well as via 810 are typically constructed from metal, such as, for example, copper (Cu) or tungsten (W), and are both good electrical and thermal conductors. Via 814 is thermally coupled to drain 824 through diffused region 818 , of an impurity type opposite drain diffusion 824 , which provides a thermal connection while maintaining electrical isolation of via 814 and cold plate 828 from drain 824 . Via 812 is thermally coupled to source 822 through a similarly diffused region 820 which provides a thermal connection while maintaining electrical isolation of via 812 and cold plate 828 from source 822 .
[0046] Thus, as heat is built up in transistor 808 by RF operation, the heat is carried away through vias 812 and 814 to cold plate 828 of TEC 832 . The heat is then transferred from cold plate 828 to heat spreader 830 where it may be dissipated away from the IC chip 800 .
[0047] Optionally, a reactive ion etch (RIE) etch of section 844 can be performed. The RIE etch forms a trench in section 844 which aids in ensuring further thermal isolation of cold plate 828 from via 810 , which is connected to hot plate 838 .
[0048] The structure depicted in FIG. 8 is given as an example of a thermoelectric spot cooler directly coupled to an RF IC device and is not intended to limit the present invention. For example, more or fewer metallization layers M 1 -M 5 , and LM may be utilized between the RF device, such as, for example, transistor 808 and cold plate 828 . Furthermore, transistor 808 may be any single or composite temperature sensitive device without departing from the scope and spirit of the present invention. Also, it should be noted that the present invention is not limited to RF transistors constructed as SOI transistors, but may be applied to bulk transistors and event to RF devices other than transistors. Furthermore, the elements of IC chip 802 may be constructed from other substances and compounds than those depicted.
[0049] With reference now to FIG. 9, a cross sectional view of an exemplary RF spiral inductor circuit wherein the thermoelectric cooler is incorporated in the passive inductor and the heat is rejected into the bulk substrate is depicted in accordance with the present invention. IC chip 900 includes spiral inductors having components 908 and 910 visible in the depicted view. Spiral inductor components 908 and 910 are formed from an electrically conductive material such as, for example, copper (Cu). Spiral inductor is formed in the cold end 904 and the inductor leads 908 and 910 of the inductor components are thermally coupled to cold end 904 which in turn is supported in part above the surface 930 of IC chip 900 by photoresist (PR) support 912 .
[0050] Thermoelectric cooler 902 includes a thin electrically but not thermally conducting layer 906 to couple cold end 904 to the cold ends of p-type element 914 and n-type element 916 of the TEC. Current to drive the TEC is provided through conductor 932 , which in the depicted example, lies in the second metallization layer M 2 . Thermoelectric cooler 902 also includes a second thin thermally but not electrically conductive layer 918 to provide a thermal coupling to via 920 . Via 920 then provides a thermal connection through oxide layers 922 to hot end 924 at substrate 926 . As heat is generated in the spiral inductor, it is transported by TEC 902 from cold end 904 to hot end 924 and into the bulk silicon substrate 926 , thus cooling the spiral inductor.
[0051] Although the present invention has been described primarily with reference to dissipating the heat either into the bulk substrate or into the atmosphere surrounding the integrated circuit via a hot plate located the surface of the integrated circuit, the heat may also be dissipated by other means. For example, the heat may be rejected via heat pipes rather than directly in air. Furthermore, the thermoelectric coolers are not limited to a single type of thermoelectric cooler, but may be implemented as any one of several different types of thermoelectric coolers, such as, for example, quantum point coolers.
[0052] It should also be noted that the present invention allows metal structures with photoresist or dielectric supports to be easily incorporated in the cooling process. Furthermore, it should also be noted that the present invention is not limited by the exemplary structure depicted and that there are a large number of alternative structures which may be utilized without departing from the scope and spirit of the present invention.
[0053] The description of the present invention has been presented for purposes of illustration and description, and is not intended to be exhaustive or limited to the invention in the form disclosed. Many modifications and variations will be apparent to those of ordinary skill in the art. The embodiment was chosen and described in order to best explain the principles of the invention, the practical application, and to enable others of ordinary skill in the art to understand the invention for various embodiments with various modifications as are suited to the particular use contemplated. | An apparatus for cooling selected elements within an integrated circuit, such as active transistors or passive circuit elements used in a radio frequency integrated circuit is provided. In one embodiment, the cooling apparatus includes a cold plate thermally coupled to the region proximate the integrated circuit element, a thermoelectric cooler thermally coupled to the cold plate; and a hot plate thermally coupled to the thermoelectric cooler. Heat is removed from the integrated circuit element through the cold plate and transmitted to the hot plate through the thermoelectric cooler. In one form, the hot plate is located or coupled to an exterior surface of an integrated circuit, such that heat transmitted to the ambient from the integrated circuit element is dissipated into the atmosphere surrounding the integrated circuit. In another form, the hot plate is embedded in the integrated circuit substrate to locally cool elements of the integrated circuit while dumping the heat into the substrate. | 7 |
CROSS-REFERENCE TO RELATED APPLICATION
This application is a continuation-in-part of U.S. patent application Ser. No. 07/673,263, filed Mar. 20, 1991, now abandoned, which is a continuation of U.S. patent application Ser. No. 07/351,436, filed May 12, 1989, now abandoned. U.S. patent application Ser. No. 07/673,263 is in turn a continuation-in-part of U.S. patent application Ser. No. 07/673,264, filed Mar. 20, 1991, which is a continuation of U.S. patent application Ser. No. 07/335,691, filed Apr. 10, 1989, now abandoned.
BACKGROUND OF THE INVENTION
Aspartokinase (ATP:4-L-Aspartate-4-phosphotransferase [EC 2.7.2.4]) catalyses the conversion of aspartate and ATP to 4-phosphoaspartate and ADP. As shown in FIG. 1 for E. coli, aspartokinase is the first enzyme utilized in the biosynthetic pathway leading to lysine, threonine, and methionine. The biosynthesis of these nutritionally important amino acids is highly regulated. One mechanism for the regulation of this pathway is via the production of several isozymes of aspartokinase having different repressors and allosteric inhibitors. In both Escherichia coli and recently in Bacillus subtilis, three isozymes of aspartokinase differing in their sensitivity to repression and inhibition by lysine, threonine, methionine, and diaminopimelate have been identified. The three B. subtilis isozymes are feedback-inhibited by diaminopimelate, lysine, or threonine plus lysine, respectively (L. M. Graves, J. Bacteriol., 172, 218 (1990)). The lysine-sensitive aspartokinase II from B. subtilis has been purified to homogeneity by D. Moir et al., J. Biol. Chem., 252, 4648 (1977). The gene encoding this enzyme has also been cloned and sequenced, as reported by R. P. Bondaryk et al., J. Biol. Chem., 260, 592 (1985) and N. Y. Chen et al., J. Biol. Chem., 262, 8787 (1987).
Recently, F. J. Schendel et al. in J. Appl. Environ. Microbiol., 56, 963 (1990), identified homoserine auxotrophs and S-(2-aminoethyl)-cysteine (AEC) resistant mutants of a thermophilic methylotrophic Bacillus sp. which overproduce significant quantities of L-lysine at 50° C. Such thermophilic methylotrophs may have advantages over other organisms for industrial use, as discussed by Al-Awadhi et al., Biotechnol. Bioeng., 36, 816, 821 (1990). In particular, the methylotrophic Bacillus MGA3 identified by F. J. Schendel et al., cited supra, may have significant advantages over other bacilli for the overproduction of lysine since it does not sporulate at high temperatures even under conditions of nutrient limitation, in contrast to lysine-producing mutants of B. licheniformis that sporulated when grown at temperatures greater than 40° C. (H. Hagino et al., Biotechnol. Lett., 3, 425 (1981)).
Since both spore components, diaminopimelate and dipicolinic acid, are derived from the lysine biosynthetic pathway, as shown in FIG. 1, differences in the regulation of this pathway may occur between this thermophilic Bacillus sp. and other mesophilic bacilli. Therefore, a need exists to isolate and characterize the informational macromolecules (DNA and RNA) which function in the biosynthetic pathway to lysine, methionine and threonine in the thermotolerant Bacillus sp. MGA3. A further need exists to isolate and characterize the products, such as the enzymes, that function in these biosynthetic pathways. A further need exists to produce mutant varieties of said informational macromolecules, in order to improve the properties of the enzymes and other polypeptides encoded thereby, or to produce improved strains of thermotolerant, methylotrophic bacteria.
SUMMARY OF THE INVENTION
The present invention provides a DNA sequence in substantially pure form, which corresponds to the structural gene coding for the αB dimer subunit of lysinesensitive aspartokinase II (AKII) of the methylotrophic thermotolerant Bacillus sp. MGA3. The native form of this enzyme is an α 2 B 2 tetramer. The DNA sequence was identified by cloning the structural gene from a genomic library via complementation of an Escherichia coli auxotrophic mutant lacking all three aspartokinase isozymes. The nucleotide sequence of the entire 2.2 Kb PstI fragment has been determined to be as depicted in FIG. 2 and a single open reading frame coding for the aspartokinase II enzyme was identified at positions 664-1885 of this fragment.
The present invention also provides a substantially pure enzyme corresponding to this form of aspartokinase II (AKII) and a substantially pure polypeptide corresponding to the αB dimer subunit of AKII. AKII is an α 2 β 2 tetramer (M r 122,000) with the β subunit (M r 18,000) being encoded within the α subunit (M r 45,000) in the same reading frame. The N-terminal sequence of both the α and β subunit were found to be identical with those predicted from the gene sequence. The predicted AKII sequence of 411 amino acids is only 76% identical with the sequence of the B. subtilis aspartokinase II. The transcription initiation site of the AKII gene is located approximately 350 base pairs upstream of the translation start site, and putative promoter regions at -10 (TATGCT) and -35 (ATGACA) were also identified. Therefore, this gene represents a significant point of divergence of the MGA3 lysine biosynthetic pathway from the pathway operative in other mesophilic bacilli.
Availability of the MGA3 AKII gene, coupled with knowledge of its sequence, permits the production of mutant forms of the present AKII, via mutagenesis of the gene. Mutant forms of the MGA3 AKII gene may be useful to produce microorganisms such as new strains of bacteria, which overproduce lysine at higher levels, or under even more stringent environmental conditions. Methodologies for the mutagenesis of the MGA3 AKII gene are discussed in detail hereinbelow.
As used herein, with respect to an enzyme or a subunit thereof, the term "corresponding to aspartokinase II (AKII)" is intended to mean that the enzyme or the subunit referred to exhibits substantial sequence homology to AKII derived from MGA3 (e.g., ≧85-90%) and that the enzyme also exhibits a substantially equivalent profile of bioactivity, e.g., exhibits ≧85-90% of the lysine sensitivity exhibited by AKII from MGA3.
As used herein, with respect to a DNA sequence which encodes AKII or a subunit thereof, the term "substantially pure" means that the DNA sequence is free of other DNA sequences that occur naturally in MGA3, e.g., that it has been isolated from MGA3, via the methodologies of recombinant DNA technology, as described herein, or has bee prepared by known techniques of organic synthesis. Likewise, as used with respect to an AKII enzyme or a subunit thereof, the term "substantially pure" means that the enzyme is free of the other components of naturally occurring Bacillus, in that it has been isolated from a biological medium or has been prepared by known techniques organic synthesis or of recombinant DNA technology.
All the patents, patent documents and publications cited herein are incorporated by reference herein.
BRIEF DESCRIPTION OF THE DRAWINGS
FIG. 1 is a schematic depiction of the lysine biosynthetic pathway in E. coli wherein the following letters indicate the following enzymes: a--aspartokinase; b--aspartylsemialdehyde dehydrogenase; c--dihydrodipicolinic acid synthase; d--dihydrodipicolinic acid reductase; e--succinyloxoaminopimelate synthase; f--succinyldiaminopimelate amino transferase; g--succinyldiaminopimelate desuccinylase; h--diaminopimelate racemase; and i--mesodiaminopimelate decarboxylase.
FIGS. 2A-2D depict the nucleotide sequence of the 2.2 Kb PstI fragment of the genomic clone pAA8671 (Sequence I.D. No. 1) and the derived amino acid sequence for Bacillus MGA3 aspartokinase II αB dimer subunit (Sequence I.D. No. 2). Regions of dyad symmetry are overlined with arrows, potential ribosome binding sites are underlined, the -10 and -35 regions of the putative promoter are boxed, and the transcription initiation site is marked with an asterisk.
FIGS. 3A and 3B are a comparison of the predicted and determined N-terminal amino acid sequences for (a) the α subunit, and (b) the β subunit of AK-II from B. MGA3.
DETAILED DESCRIPTION OF THE INVENTION
The invention will be described by reference to the following detailed examples, wherein the bacterial strains, vectors and recombinant plasmids used are summarized in Table 1, below.
TABLE 1__________________________________________________________________________Bacterial Strains and PlasmidsStrain Relevant Markers Reference or Source__________________________________________________________________________Escherichia coliDH5αF' F'φ80dlacZΔM15 Δ(lacZYA-argF)U169 recA1 end Bethesda Research Lab hsdR17(r.sub.K -, m.sub.K +) supE44λ.sup.- thi-1 gyrA relA1Gif106M1 F.sup.- thrA1101 supE44 λ.sup.- rpsL9 malT1(λ.sup.R) xyl-7 Barbra Bachman mtl-2 ilvA296 metL1000 arg-1000 thi-1 lysC1001BacillusMGA3 -- ATCC 53907MGA3 S-12 Hse.sup.- R. S. HansonPlasmidspUC19cm Cm.sup.r J. FuchspBR322 Tc.sup.r, Ap.sup.r F. Bolivar et al..sup.bpAA8363 Tc.sup.r, AK.sup.+a This studypAA8671 Cm.sup.r, AK.sup.+ This studypAA8802 Cm.sup.r, AK.sup.- This study__________________________________________________________________________ .sup.a AK, Aspartokinase activity. .sup.b F. Bolivar et al., Gene, 2, 95 (1977).
A. Media and Growth Conditions
Strains of E. coli were grown at 37° C. in baffled Erlenmeyer flasks (Bellco) rotated at 280-320 rpm (Labline) on SOC medium (D. Hanahan, "Techniques for transformation of E. coli," in DNA Cloning: A Practical Approach, D. M. Glover, ed., IRL Press, Washington, D.C. (1985) at pages 109-135), or M9 medium (T. Maniatis et al., Molecular Cloning: A Laboratory Manual, Cold Spring Harbor Laboratory, Cold Spring Harbor, N.Y. (1982)). Auxotrophic stains were implemented with 50 μg/ml of the appropriate amino acid. Bacillus MGA3 (ATCC 53907, American Type Culture Collection, Rockville, Md., USA) was grown at 53° C. in baffled flasks rotated at 350 rpm on MY medium (F. J. Schendel et al., cited supra) containing 1% methanol. Solid media contained 15 g of agar (Sigma, St. Louis, Mo.) per liter of medium. Selective media contained antibiotics at the following concentrations: 15 μg tetracycline per ml, 35 μg chloramphenicol per ml, 100 μg ampicillin per ml, and 50 μg streptomycin sulfate per ml.
B. Recombinant Genetic Methods
DNA manipulations were carried out according to T. Maniatis et al. (cited supra) unless otherwise stated. Transformations of E. coli strains DH5αF' and GM2163 were carried out according to D. Hanahan (cited supra). Electrotransformation of E. coli strain Gif106M1 was carried out using a Gene Pulser apparatus (Bio-Rad Lab; Richmond, Calif.) at 12.5 KV per cm and 25 μFD capacitance. Cells were allowed to recover for one hour in SOC medium before plating. Electrocompetent E. coli Gif106M1 cells were prepared by growth in SOC to mid-log phase. One liter of cells were harvested by centrifugation at 7,000×g, washed twice with an equal volume of cold sterile water, and resuspended in 40 ml cold 10% glycerol. The cells were harvested by centrifugation, resuspended in 2 ml cold 10% glycerol, and 150 μl samples frozen in a dry-ice ethanol bath. The cells were then stored at -80° C. until needed. Restriction endonucleases, T4 DNA ligase, AMV reverse transcriptase, and bacterial alkaline phosphatase were purchased from Bethesda Research Labs (Gaithersburg, Md.) and used according to the instructions of the supplier. Bacillus MGA3 chromosomal DNA was isolated from cells grown in MY medium using the method of R. E. Yasbin et al., J. Bacteriol., 121, 269 (1975).
C. DNA Sequencing and Analysis
Nested deletions were constructed by unidirectional exonuclease III-S1 nuclease digestion (Erase-a-base, Promega Corp., Madison, Wis.). The DNA sequence was determined by the dideoxy-chain termination method of F. Sanger et al., PNAS USA, 74, 5463 (1977) for both strands using Sequenase (United States Biochemicals, Cleveland, Ohio). Analysis of the DNA sequence data was carried out using Intellagenetics software (University of Minnesota Molecular Biology Computing Center).
D. Primer Extension
Total RNA was isolated and primer extension was performed as described by F. M. Ausubel et al., in Current Protocols in Molecular Biology, John Wiley & Sons, N.Y. (1987). For the isolation of RNA, E. coli was grown in SOC and B. MGA3 was grown in minimal methanol media (F. S. Schendel et al., cited supra). Total RNA was isolated from E. coli as described by F. M. Ausubel et al., cited supra, and from B. MGA3 as described by H. Shimotsu et al., J. Bacteriol., 166, 461 (1986). A 24-mer oligonucleotide complementary to the coding strand base pairs 383-406 was endlabeled with 32 P and used as the primer. The products were analyzed on a 6% polyacrylamide-urea gel.
E. Cloning of Aspartokinase II Gene
A chromosomal library of Bacillus MGA3 DNA was constructed by partial digestion of the Bacillus MGA3 chromosomal DNA with PstI followed by ligation with the PstI digested, alkaline phosphatase treated vector, pBR322. The ligation reaction was electrotransformed into E. coli Gif106M1 cells and tetracycline-resistant transformants selected on SOC medium. The tetracycline-resistant colonies were scraped off the SOC plates, washed twice with SSC, then plated onto M9 medium. Aspartokinase II positive clones were identified by their ability to grow on M9 medium lacking lysine, threonine, and methionine.
F. Enzymatic Assays and N-terminal Sequencing of Aspartokinase II
Aspartokinase II was assayed by measuring the amount of aspartyl-β-hydroxamate formed as described by M. J. M. Hitchcock et al., Biochem. Biophys. Acta, 445, 350 (1976). Determination of the apparent K i for lysine inhibition was carried out with partially purified aspartokinase II from E. coli/pAA8671. Cells were broken in a French press pressure cell at 16,000 psi, cell debris removed by centrifugation at 40,000×g for 1 hour, and the supernatant fractionated between 35-50% saturation with ammonium sulfate. The sample was desalted on Sephadex G-25, and apparent K i for lysine determined by varying the amount of lysine added to the assay in the presence of saturating amounts of aspartate and ATP. Determination of the N-terminal sequence of aspartokinase was carried out by automated Edman degradation at the University of Minnesota Microchemical Facility. Approximately 1 nmol of aspartokinase was run on a 14% SDS gel (U. K. Laemmuli, Nature, 227, 680 (1970)) to separate the α and β subunits, then electroblotted onto Applied Biosystems (Forest City, Calif.) ProBlot PVDF membrane, following the manufacturer's instructions. The membrane was stained for 15 seconds with Coomassie Blue R-250 (ICN, Cleveland, Ohio), destained with 50% methanol, and the bands corresponding to the α and β subunits excised and submitted for sequencing.
G. Results
1. Aspartokinase Isozymes From Bacillus sp. MGA3
Recent work in B. subtilis has demonstrated the existence of three aspartokinase isozymes that differ in their feedback inhibition and repression (L. M. Graves et al., cited supra). In order to determine the number of aspartokinase isozymes present in the thermophilic methylotroph B. MGA3, assays of cell extracts were carried out in the presence of lysine, threonine, or diaminopimelate alone or in combination, in accord with the methodology of J.-J. Zhang et al., J. Bacteriol., 172, 701 (1990). The results of these assays are shown in Table 2, and are consistent with the presence of three isozymes; one inhibited by diaminopimelate, one inhibited by lysine alone, and one inhibited by lysine plus threonine.
TABLE 2______________________________________Inhibition of Aspartokinase FromBacillus MGA3 by Amino AcidsAmino Acid Inhibition(5 mM) (%)______________________________________None 100.sup.aLysine 42Lysine + Threonine 85Diaminopimelate 12Diaminopimelate + Lysine 55Diaminopimelate + Lysine + Threonine 98______________________________________ .sup.a Corresponds to a specific activity of 0.011 U/mg protein.
2. Cloning the Structural Gene Coding for Aspartokinase II from Bacillus sp. MGA3
Previous studies by M. Y. Chen et al., J. Biol. Chem., 262, 8787 (1987) showed that the gene coding for aspartokinase II from Bacillus subtilis complemented E. coli Gif106M1, which lacks all three aspartokinase isozymes, (J. Theze et al., J. Bacteriol., 117, 133 (1974)), by restoring its ability to grow on minimal medium lacking lysine, threonine and methionine. To obtain the gene coding for aspartokinase from the thermophilic methylotroph Bacillus sp. MGA3, a chromosomal library was constructed by partial PstI digestion of the MGA3 chromosome. The fragments generated were cloned into pBR322, and used to transform E. coli Gif106M1 to impart tetracycline resistance. After plating onto minimal medium, 40 clones were identified that restored the ability of E. coli Gif106M1 to grow on minimal medium lacking lysine, threonine and methionine. Analysis of 16 of these clones showed that they all shared a common 2.2 Kb PstI fragment. One of these clones, pAA8363, was used for further characterization.
In order to determine if the restored ability to grow in the absence of lysine, threonine, and methionine was due to aspartokinase, enzymatic analysis of cell extracts was carried out, with the results shown in Table 3.
TABLE 3______________________________________Expression of Aspartokinase Activity in E. coli Aspartokinase ActivityStrain Plasmid (U/mg of protein)______________________________________DH5αF' none 0.0021.sup.aGif106M1 none 0.0002.sup.bGif106M1 pBR322 0.0002.sup.bGif106M1 pUC19cm 0.0001.sup.bGif106M1 pAA8363 0.022.sup.aGif106M1 pAA8363 0.021.sup.bGif106M1 PAA8802 0.0001.sup.b______________________________________ .sup.a Cells were grown in minimal M9 medium lacking lysine, threonine, and methionine. .sup.b Cells were grown in minimal M9 medium containing lysine, threonine and methionine.
As shown in Table 3, significant levels of aspartokinase activity were only found in the wild type E. coli DH5αF' and in Gif106M1 cells carrying the plasmid pAA8363. No repression of aspartokinase activity was observed when the cells were grown in the presence of 50 μg/ml of lysine, threonine, and methionine (Table 3). Assays were performed in the presence of threonine, methionine, lysine, and diaminopimelate alone, and in combination, but only lysine was shown to inhibit enzyme activity, with an apparent K i of 100 μM.
Inactivation of the aspartokinase activity was carried out by subcloning the 2.2 Kb PstI fragment into the PstI site of pUC19cm, followed by removal of a 0.6 Kb AvaI fragment from pAA8671. The resulting clone, pAA8802, was examined for aspartokinase activity (Table 3) as well as ability to support growth of Gif106M1 on minimal medium lacking lysine, threonine, and methionine. No significant aspartokinase activity was detected, and pAA8802 would not support growth of E. coli Gif106M1 on minimal medium lacking lysine, threonine, and methionine.
The approximate location of the aspartokinase gene and control regions on the 2.2 Kb PstI fragment was determined by creating a series of unidirectional deletions, and testing each of these for their ability to support growth of Gif106M1 on a minimal medium lacking lysine, threonine, and methionine. Aspartokinase activity was lost when deletions were made 420 base pairs from the 3' end of the fragment, and 350 base pairs from the 5' end.
3. Nucleotide and Derived Amino Acid Sequences of Aspartokinase
The entire 2.2 Kb PstI fragment was sequenced (FIG. 2). The nucleotide sequence (SEQ. I.D. No. 1) revealed one major open reading frame starting at base pair 790, however, there is no potential ribosome binding site preceding this possible start site. A preferred translation start site is apparent at position 664, where a GTG is preceded by a potential ribosome binding site (AAGGGA) underlined in FIG. 2). This translational start site was in complete agreement with the N-terminal amino acid sequence of the α subunit as shown in FIG. 3(A). A second start site preceded by a potential ribosome binding site, AGGAGG, was found in the same reading frame beginning at base pair 1399. This smaller open reading frame may correspond to the smaller β subunit of aspartokinase. As shown in FIG. 3(B), this second translational start site was in complete agreement with the N-terminal sequence of the β subunit. A stop codon was found at base pair 1897 resulting in predicted molecular weights for the α and β subunits of 44,313 and 17,899, respectively, and these were in good agreement with the values obtained by SDS gel electrophoresis of 45,000 and 18,000, respectively. The native molecular weight of aspartokinase was found to be 122,000 by gel filtration on Sephacryl-300, which is in good agreement with the predicted molecular weight of 124,424 for an α 2 β 2 tetramer.
The transcription initiation site was found by primer extension to correspond to the `A` residue at position 297 in both the B. MGA3 and from the cloned gene in E. coli DH5αF'/pAA8671. The sequences TATGCT and ATGACA near the -10 and -35 regions correspond to a putative aspartokinase promoter (boxed in FIG. 2). Two regions of dyad symmetry with ΔG's of -18.6 and -11.1 kcal are found in the intervening sequence between transcription initiation and the translation start site (FIG. 2), and the second region contains a series of T residues following the hairpin loop typical of a rho-independent terminator. Another region of dyad symmetry with a ΔG-23.2 kcal occurs distal to the coding region, but lacks a run of T residues following the hairpin loop common to rho-independent terminators.
4. Amino Acid Sequence Comparisons of Aspartokinase
Sequence data are now available for six microbial aspartokinase isozymes, three E. coli (M. Cassan et al., J. Biol. Chem., 261 1052 (1986) (K12); M. Katinka et al., PNAS USA, 73, 5730 (1980); M. M. Zakin et al., J. Biol. Chem., 258, 3028 (1983)), the Bacillus subtilis aspartokinase II (N. Y. Chen et al., cited supra), and Saccharomyces cerevisiae (J. A. Rafalsk et al., J. Biol. Chem., 263, 2146 (1988). The deduced amino acid sequence for B. MGA3 aspartokinase II (SEQ. I.D. No. 2) was compared with the proposed alignment for the B. subtilis aspartokinase II, and the three E. coli aspartokinase isozymes, the S. cerevisiae isozyme and the E. coli isozymes, the S. cerevisiae isozyme, and the E. coli isozyme. Some similarity exists between the deduced amino acid sequence of B. MGA3 aspartokinase and the B. subtilis aspartokinase II, with 76% of amino acid residues being identical. When the amino acid sequence of B. MGA3 aspartokinase is compared with the three E. coli aspartokinases and the S. cerevisiae enzyme, less similarity is found. Only 29, 23, 20, and 17% of its amino acid residues are identical to those of E. coli aspartokinase III, I, II and the S. cerevisiae aspartokinase, respectively. These findings support the assignment of MGA3 to the genus Bacillus, as discussed by F. J. Schendel et al., cited supra.
H. Discussion
Complementation of the E. coli strain Gif106M1, a mutant in all three aspartokinase isozymes, resulted in the selection of only the gene coding for aspartokinase II from B. MGA3, and neither of the genes coding for aspartokinase I or III. This is probably due to the inability of E. coli to recognize either the Bacillus promoters or Shine-Dalgarno sequences for these two isozymes (L. Band et al., DNA, 3, 17 (1984); G. Lee et al., Mol. Gen. Genet., 180, 57 (1980)). The proposed -10, TATGCT, and -35 regions, ATGACA, are similar to the compiled -10, TATAAT, and -35, TTGACA, regions from several B. subtilis genes (as reported by C. P. Moran et al., Mol. Gen. Genet., 186, 339 (1982)), and to the -10, TAAAAT, and -35, TTGTCC, regions of the B. subtilis aspartokinase II gene (N. Y. Chen et al., J. Biol. Chem., 262, 8787 (1987)). The expression of the gene coding for aspartokinase II in E. coli results from transcription initiation at the same site as in B. MGA3, and is probably due to the similarity of the -10 and -35 regions to the consensus sequences of E. coli -10, TATAAT, and -35, TTGACA, regions. In addition, the proposed Shine-Dalgarno sequences for the aspartokinase II α and β subunits, AAGGGA and AGGAGG, respectively, are both very similar to the consensus sequence, AAGGAG, of B. subtilis (C. P. Moran et al., Mol. Gen. Genet., 186, 339 (1982)). These proposed ribosome binding sites are also very similar to the E. coli consensus sequence, AGGAGG (J.-C. Patte et al., Biochem. Biophys. Acta., 136, 245 (1967)).
The large, >300 nucleotides, intervening sequence that exists between the transcription initiation and translation start sites (FIG. 2), may function in the control of aspartokinase II expression in the presence of lysine. Unlike the control sequence for the B. subtilis aspartokinase II, that contains characteristics similar to attenuators from several E. coli amino acid biosynthetic operons, as shown by R. Kolter et al., Ann. Rev. Genet., 16, 113 (1982), no open reading frame preceded by a ribosome binding site that contained a lysine rich peptide was found. This also explains why attenuation of aspartokinase II was not observed when E. coli Gif106M1/pAA8363 was grown in the presence of lysine (Table 3). In contrast, growth inhibition due to 22 μM lysine wa observed with E. coli Gif106M1 carrying a single copy plasmid containing the gene encoding the B. subtilis aspartokinase II (N. Y. Chen et al., J. Biol. Chem., 263, 9526 (1988)). While part of this inhibition may have been due to feedback inhibition, since the aspartokinase II from B. subtilis had a K i 100 μM (30), it is likely that some of the growth inhibition resulted from attenuation of the aspartokinase gene.
EXAMPLE I
Mutagenesis of Aspartokinase II Gene
Site-directed mutants were constructed by in vitro second strand synthesis (Altered Sites, Promega Corp., Madison, Wis.) or by the method of T. A. Kunkel et al., PNAS USA, 82, 488 (1985) (Muta-Gene, Bio-Rad, Richmond, Calif.) using a mismatched oligonucleotide primer of 18-24 base pairs. A 19 base pair primer corresponding to the sequence 5'-TTTTGTTCTAATGTTACTT was used to change the `T` and `G` at positions 1400 and 1401 to `A` and `T` respectively. This results in an amino acid change from methionine to leucine at position 246 in the protein sequence. In addition, this amino acid substitution eliminates the initiation codon for the synthesis of the β subunit resulting the synthesis of only the α subunit. Analysis of cell extracts containing this altered (α 2 ) enzyme revealed that the aspartokinase activity and inhibition by lysine was essentially identical to the wild type (α 2 β 2 ) protein. This result was similar to the result obtained by Chen and Paulus, cited above.
In vitro plasmid mutagenesis was carried out using hydroxylamine as described by C. Wolf et al., J. Bacteriol., 170, 4509 (1988). One μg of pAA8671 DNA was treated with 100 uL of 0.4 M hydroxylamine in 0.5 M potassium phosphate (pH 6.0) for 36 hours at 37° C. The sample was then dialyzed for 12 hours against 4 L of 1 mM EDTA (pH 7.0). Electrocompetent E. coli Gif106M1 cells were then transformed by electroporation with 1 ul of the dialyzed sample. The cells were allowed to recover for 1 hour in SOC, then plated onto minimal media containing 10 g/l lysine, and grown for 24 hours at 37° C. Ten colonies were selected, grown at 37° C. for 16 hours in TB containing 35 ug/ml chloramphenicol. The cells were collected by centrifugation, suspended in 50 mM potassium phosphate, and sonicated for 30 seconds to disrupt the cells. Aspartokinase II enzyme assays were preformed in the presence and absence of 100 mM lysine. Two clones, 9234 and 9236, showed decreased sensitivity to lysine with apparent K I 's of 10 and 100 mM, respectively, compared to a K I of 100 uM for wild type enzyme.
The DNA coding for these altered enzymes was sequenced and only a single base pair change was found in each case. In pAA9234, a `T` replaces the `C` at position 1790 resulting in a single amino acid change from a serine to leucine at position 376 of the protein sequence. In pAA9236, a `T` replaces the `C` at position 1730 resulting in a single amino acid change from an alanine to a valine at position 356 of the protein sequence.
From the results of these mutagenesis experiments, specific mutations in the α subunit alone should result in altered lysine feedback inhibition in a wide variety of transformants.
The invention has been described with reference to various specific and preferred embodiments and techniques. However, it should be understood that many variations and modifications may be made while remaining within the spirit and scope of the invention.
__________________________________________________________________________SEQUENCE LISTING(1) GENERAL INFORMATION:(iii) NUMBER OF SEQUENCES: 2(2) INFORMATION FOR SEQ ID NO: 1:(i) SEQUENCE CHARACTERISTICS:(A) LENGTH: 2223 base pairs(B) TYPE: Nucleic Acid(C) STRANDEDNESS: Single(D) TOPOLOGY: Linear(ii) MOLECULE TYPE: Genomic DNA(vi) ORIGINAL SOURCE: 2.2 Kb Pst frag. of PAA8671(ix) FEATURE:(A) NAME/KEY: Aspartokinase II Gene(B) LOCATION: 1 to 2223(xi) SEQUENCE DESCRIPTION: SEQ ID NO: 1:TTACGCCAAGCTTGCATGCCTGCAGCGAATCCAAGATGAAGTGCACAGATTTGCGATTAC60TTTCCACCGTCAATTGCGGGGGAAAAATGCTTTTCAATCGTTATTGGA CGATATACCAGG120AATTGGTGAAAAACGGAAAAAACTGCTTCTTAAACAATTTGGTTCCGTAAAAAAAATGAA180GGAAGCAACAATGGCGGAAATTACATCTGTCGGCATTCCGGCAAATGTTGCAAAAGAATT240GATGAAAAAGTTGCATGAATGACAT TGTCATAAATCAGGTCGTATGCTATACTGAAAAAA300ATTTTATAGTGTAATCACTTTAGAGCATTAAAGTGAAGATAGAGGTGCGAACTTCATCAG360TAAAAGCTTGGAGAAGAATGAGCTTCAATGAAAAGCTTTGAAAGGGAACGTTCGCCGAAG420TG AAGAAAAACTCATTTTTTTCTTTGCTGGTCCTGCATTTAAGAGATGCCGGATTGTCAA480GGCGGTGCCGCCTTGGAGAGCTATCTCACTGTGTCTGCGTATTTTACTACGTTATCCACA540GCAATGAGGTAGCTTTCTCATTGCTGTTTTTTATTAAATTAAAAACAG CTTCATTGAGAA600AGCTAGTTATACATAAAATGGCGGCACTTCTTTGATTAATTTCATAGAAAGAAGGGAAAA660AAAGTGGGATTAATTGTCCAAAAGTTTGGCGGAACATCTGTTGGCTCC708ValGlyLeuIleValGln LysPheGlyGlyThrSerValGlySer151015GTTGAGCGCATCTTAAACGTTGCCAATCGGGTAATTGAAGAAAAAAAG756ValGluArgIleLeuAsn ValAlaAsnArgValIleGluGluLysLys202530ACCGGAAATGACGTTGTTGTGGTTGTTTCTGCAATGGGGAAGACAACA804AsnGlyAsnAspValVa lValValValSerAlaMetGlyLysThrThr354045GATGAGCTTGTCGATTTAGCAAAACAAATTTCAGCACATCCACCAAAG852AspGluLeuValAspLeuA laLysGlnIleSerAlaHisProProLys505560CGCGAAATGGATATGCTTCTTACAACCGGAGAGCAAGTGACGATTTCG900ArgGluMetAspMetLeuLeuThr ThrGlyGluGlnValThrIleSer657075CTTTTGGCTATGGCATTGAATGAAAAAGGCTATGAGGCCATTTCCTAT948LeuLeuAlaMetAlaLeuAsnGluLysGlyTyr GluAlaIleSerTyr80859095ACTGGATGGCAGGCAGGAATTACAACTGAACCTGTTTTTGGGAACGCG996ThrGlyTrpGlnAlaGlyIleThrThrGl uProValPheGlyAsnAla100105110AGAATATTAAATATCGAAACCGAAAAAATTCAAAAACAGCTAAACGAA1044ArgIleLeuAsnIleGluThrGluLysI leGlnLysGlnLeuAsnGlu115120125GGAAAAATTGTCGTAGTTGCCGGCTTCCAAGGTATTGATGAGCACGGA1092GlyLysIleValValValAlaGlyPheGln GlyIleAspGluHisGly130135140GAAATTACGACTCTTGGGAGAGGCGGATCCGATACTACGGCTGTAGCA1140GluIleThrThrLeuGlyArgGlyGlySerAspThr ThrAlaValAla145150155CTTGCTGCGGCTTTGAAAGCCGAAAAATGTGATATTTACACCGATGTT1188LeuAlaAlaAlaLeuLysAlaGluLysCysAspIleTyrThrAs pVal160165170175ACTGGAGTTTTTACTACAGATCCGCGCTATGTAAAGTCGGCTAGGAAG1236ThrGlyValPheThrThrAspProArgTyrValLysSerA laArgLys180185190CCTGCTTCTATTTCATATGATGAAATGCTTGAACTTGCGAATCTTGGT1284LeuAlaSerIleSerTyrAspGluMetLeuGluLeuAla AsnLeuGly195200205GCGGGCGTCCTTCATCCAAGAGCAGTAGAATTTGCGAAAAATTACGGA1332AlaGlyValLeuHisProArgAlaValGluPheAlaLysAsn TyrGly210215220ATTACTTTGGAGGTGCGCTCCAGTATGGAACGAGAAGAAGGGACGATC1380IleThrLeuGluValArgSerSerMetGluArgGluGluGlyThrIl e225230235ATTGAGGAGGAAGTAACAATGGAACAAAATCTTGTTGTCCGGGGAGTA1428IleGluGluGluValThrMetGluGlnAsnLeuValValArgGlyVal240 245250255GCTTTTGAAGATGAAATCACTCGAGTAACAGTTTTTGGATTGCCAAAC1476AlaPheGluAspGluIleThrArgValThrValPheGlyLeuProAsn 260265270TCATTAACGAGTTTATCTACTATTTTTACGACACTTGCTCAAAATCGC1524SerLeuThrSerLeuSerThrIlePheThrThrLeuAlaGlnAsnArg 275280285ATTAATGTTGATATCATCATCCAAAGTGCAACTGATGCTGAAACAACA1572IleAsnValAspIleIleIleGlnSerAlaThrAspAlaGluThrThr 290295300AATTTATCTTTTTCCATAAAGAGCGACGATTTAGAAGAAACAATGGCC1620AsnLeuSerPheSerIleLysSerAspAspLeuGluGluThrMetAla305 310315GTCCTCGAAAACAATAAAAATTTGCTTAACTACCAAGGGATTGAATCG1668ValLeuGluAsnAsnLysAsnLeuLeuAsnTyrGlnGlyIleGluSer320325 330335GAAACGGGATTAGCAAAAGTATCGATTGTCGGTTCAGGAATGATCTCT1716GluThrGlyLeuAlaLysValSerIleValGlySerGlyMetIleSer34 0345350AACCCTGGAGTCGCAGCTAAAATGTTTGAAGTGCTTGCTTTAAATGGA1764AsnProGlyValAlaAlaLysMetPheGluValLeuAlaLeuAsnGly355 360365ATCCAAGTGAAAATGGTCAGCACTTCAGAAATAAAAGTATCGACGGTT1812IleGlnValLysMetValSerThrSerGluIleLysValSerThrVal370 375380GTTGAAGAAAGCCAGATGATCAAGGCAGTAGAAGCGCTTCATCAAGCA1860ValGluGluSerGlnMetIleLysAlaValGluAlaLeuHisGlnAla385390 395TTTGAACTGTCGGGATCCGCTGTTAAATCGGAACGCTAACGCCTAT1906PheGluLeuSerGlySerAlaValLysSerGluArg400405410ATTATAAA GAAAAACTTGAGGCTGACCCATAAGGTCCTGGCTCGCGTTTGCAGTTACTAA1966ATATTGTAGAAACAGTAATCATGTTTTTTAATATTTAGTAACTGAGAGTGCCTGGCTCTT2026AGTCTTGGGTCAGCCTTTATCCATAAATCATGGCTTTACGACGTCTTTTTTGT CCCACTT2086AACCGTTATTAGCACCTTTGATCCCTTTTTACGAGGGTGTTCAAACGCTTCAGCAATTAC2146TTTTTTTTGCTGTTCAATTTGCTGGGCAATAAATCCCGCTTCCAACTGAAAAGAGATATC2206TTTTTTTGACTGCAGGT 2223(2) INFORMATION FOR SEQ ID NO: 2:(i) SEQUENCE CHARACTERISTICS:(A) LENGTH: 411 amino acids(B) TYPE: Amino Acid(D) TOPOLOGY: Linear(ii) MOLECULE TYPE: Polypeptide(ix) FEATURE:(A) NAME/KEY: Aspartokinase II dimer subunit( B) LOCATION: 1 to 411(xi) SEQUENCE DESCRIPTION: SEQ ID NO: 2:ValGlyLeuIleValGlnLysPheGlyGlyThrSerValGlySerVal151015GluArgIleLeuAsnValAlaAsnArgVa lIleGluGluLysLysAsn202530GlyAsnAspValValValValValSerAlaMetGlyLysThrThrAsp3540 45GluLeuValAspLeuAlaLysGlnIleSerAlaHisProProLysArg505560GluMetAspMetLeuLeuThrThrGlyGluGlnValThrIleSerLeu6 5707580LeuAlaMetAlaLeuAsnGluLysGlyTyrGluAlaIleSerTyrThr859095Gly TrpGlnAlaGlyIleThrThrGluProValPheGlyAsnAlaArg100105110IleLeuAsnIleGluThrGluLysIleGlnLysGlnLeuAsnGluGly1 15120125LysIleValValValAlaGlyPheGlnGlyIleAspGluHisGlyGlu130135140IleThrThrLeuGlyArgGlyGlySe rAspThrThrAlaValAlaLeu145150155160AlaAlaAlaLeuLysAlaGluLysCysAspIleTyrThrAspValThr165 170175GlyValPheThrThrAspProArgTyrValLysSerAlaArgLysLeu180185190AlaSerIleSerTyrAspGluMetLeuGluL euAlaAsnLeuGlyAla195200205GlyValLeuHisProArgAlaValGluPheAlaLysAsnTyrGlyIle210215220 ThrLeuGluValArgSerSerMetGluArgGluGluGlyThrIleIle225230235240GluGluGluValThrMetGluGlnAsnLeuValValArgGlyValAla 245250255PheGluAspGluIleThrArgValThrValPheGlyLeuProAsnSer260265270LeuTh rSerLeuSerThrIlePheThrThrLeuAlaGlnAsnArgIle275280285AsnValAspIleIleIleGlnSerAlaThrAspAlaGluThrThrAsn290 295300LeuSerPheSerIleLysSerAspAspLeuGluGluThrMetAlaVal305310315320LeuGluAsnAsnLysAsnLeuL euAsnTyrGlnGlyIleGluSerGlu325330335ThrGlyLeuAlaLysValSerIleValGlySerGlyMetIleSerAsn340 345350ProGlyValAlaAlaLysMetPheGluValLeuAlaLeuAsnGlyIle355360365GlnValLysMetValSerThrSerGluIleLysVal SerThrValVal370375380GluGluSerGlnMetIleLysAlaValGluAlaLeuHisGlnAlaPhe38539039540 0GluLeuSerGlySerAlaValLysSerGluArg405410 | The present invention provides the isolated DNA sequence encoding the αB dimer subunit of the lysine-sensitive aspartokinase II isozyme from the thermophilic methylotrophic Bacillus sp. MGA3. | 2 |
CROSS-REFERENCE TO RELATED APPLICATION
This is a divisional application of U.S. patent application Ser. No. 09/275,346, filed Mar. 24, 1999 and entitled “Method and Apparatus for Drilling an Offshore Underwater Well,” now U.S. Pat. No. 6,497,286 which claims the benefit of 35 U.S.C. 119(a) of EP Serial No. 98302386.2 filed Mar. 27, 1998, and entitled “Method And Apparatus For Drilling An Offshore Underwater Well”, both hereby incorporated herein by reference.
STATEMENT REGARDING FEDERALLY SPONSORED RESEARCH OR DEVELOPMENT
None.
BACKGROUND OF THE INVENTION
The present invention relates to a method and apparatus for drilling an offshore underwater well.
Two conventional methods exist for drilling an offshore underwater well. The first of these is to drill and set a conductor pipe between a surface platform and the sea bed followed by drilling a surface well using a platform wellhead. The BOP is located on the surface wellhead. Subsequent casing strings are landed in the surface wellhead. The well is completed by suspending completion tubing from the wellhead and installing a platform tree. A second method is to drill and set a conductor pipe into the seabed using a floating drilling vessel with the wellhead located on the seabed. A subsea drilling BOP has to run on a drilling riser down to the seabed and is connected to the subsea wellhead. A subsea well is drilled with subsequent casing hangers landed in the subsea wellhead. The well is completed by placing a conventional tree on the seabed wellhead. An alternative subsea option is to use a horizontal tree and then run the tubing.
As the industry moves further offshore and beyond the continental shelf, the water depths being considered are drastically increasing as reservoirs down the flank of the continental shelf and on the ocean floors are discovered. These water depths rule out the use of conventional platforms and their low cost drilling techniques. Floating or tension production platform systems can be used but their drilling footprint into the reservoir is limited, requiring peripheral seabed subsea production support wells. Subsea fields involve considerable complex subsea architecture and require extensive high cost rig intervention.
One way in which an attempt has been made to increase the footprint of a production platform is the provision of a slanted conductor. In such an arrangement, the conductor is supported at an angle by the platform so that it can be run in at an angle thereby increasing the lateral distance between the base of the platform and the location where the conductor meets the seabed. However, such an arrangement is awkward and costly as it requires a specially made structure to support the conductor at an angle. Further, the system will not work in deep water without some support for the conductor at various locations between the surface and the seabed, which is not available from a floating platform.
SUMMARY OF THE INVENTION
According to the present invention, a method of drilling an offshore underwater well comprises the steps of installing a riser conduit so that it is substantially vertically supported at a production deck situated substantially at the sea surface and deviates progressively further from the vertical with increasing sea depth, fixing the riser conduit at the seabed in a non-vertical orientation, and drilling the well into the seabed at an angle to the vertical.
As the riser conduit is substantially vertically supported at the production deck, it is possible to use conventional platform drilling and production techniques which help keep the costs to a minimum. Further, because the riser conduit is supported at the surface and at the seabed, and deviates progressively further from the vertical in between, intermediate support is not required but can be provided if necessary by buoyancy modules.
In some fields, the reservoir could be relatively close to the seabed. In such a case, there is insufficient depth for a conventional subsea well which starts vertically at the seabed to be deviated to a sufficient angle to access reservoir formations not already being drained by nearby vertical or deviated wells. Therefore only a limited reservoir acreage can be accessed. With the present invention, some of this deviation from the vertical is already provided before reaching the seabed, so that less deviation is required underground which allows higher angle or horizontal wells to be drilled far along the reservoir. This allows better access to reservoirs which are close to the seabed. However, the most important benefit of the present invention arises when the water is sufficiently deep that the riser conduit can be deviated to be horizontal at the seabed. Once the riser conduit becomes horizontal, it is possible to extend it some considerable distance along the seabed before drilling into the seabed so that the drilling footprint of a platform can be greatly increased without drilling.
There are a number of different ways in which the riser conduit can be installed. According to a first method, the riser conduit is run from an installation vessel with a skid attached, installed vertically and pivotally connected at the seabed, the installation vessel is moved horizontally to the production installation while the riser conduit is fed out from the installation vessel, and the riser conduit is transferred to the production installation. According to a second method, the production deck is offset from the location where the riser conduit is connected to a skid and is to be fixed at the seabed, the riser conduit is connected to a skid and is fed down from the production deck and is maneuvered out to the end target location at the seabed. According to a third method the riser conduit is pre-made and towed to the appropriate location before being fixed at the production deck and fixed at the seabed. In this third case, the pipe may be towed out just off the seabed, and one end raised to the production deck. Alternatively, the pipe may be towed out and hung off at the platform before being lowered to the seabed and fixed.
According to a second aspect of the present invention, an offshore wellhead assembly comprises a production deck at which a riser conduit is vertically suspended, the riser conduit deviating progressively further from the vertical with increasing sea depth, the riser conduit being fixed at an angle to the vertical at the seabed by a fixture, and a cased well extending into the seabed from the fixture.
This arrangement provides the same advantages of being able to access reservoirs areas close to the seabed, and increase the drilling footprint of the production installation as referred to above.
The riser conduit may be rigidly locked to the fixture. However, in order to provide ease of installation and a fixture which can accommodate the riser at any angle it is preferable for the riser conduit to be pivotally attached to the fixture.
The fixture is preferably in the form of a skid having a gravity base or piles to secure it to the seabed. The skid is readily able to be transported to the correct location and can be simply secured to the seabed by the base or the piles.
BRIEF DESCRIPTION OF THE DRAWINGS
Examples of methods and assemblies in accordance with the present invention will now be described with reference to the accompanying drawings, in which:
FIG. 1 is a schematic view of an assembly according to a first example;
FIG. 2 shows the assembly of FIG. 1 in greater detail;
FIGS. 3A-3D show details of elements of FIG. 2;
FIG. 4 is a schematic view of a second example;
FIG. 5 is an schematic illustration of a first embodiment of the installation of a wellhead assembly;
FIG. 6 is a schematic illustration of a second embodiment of the installation of a wellhead assembly; and
FIG. 7 is a schematic illustration of a third embodiment of the installation of a wellhead assembly.
DESCRIPTION OF THE PREFERRED EMBODIMENT
FIG. 1 shows an example of a tension leg production installation 1 which is shown at the sea surface and is anchored to an optional gravity storage base 3 by mooring legs 4 . From the production installation a number of riser conduits 5 A, 5 B are suspended initially vertically, but deviating progressively from the vertical with increasing sea depth. The conduit 5 A has sufficient curvature that by the time it reaches the seabed 6 it is horizontal and can extend a significant horizontal distance along the seabed. At the desired location, the conduit 5 A terminates at a skid 7 from which a cased well 8 extends towards the production reservoir 9 where a liner or screen 10 can be positioned. The conduit 5 B is of similar construction, with the one exception that it is not horizontal at the seabed. Instead, it is fastened at an oblique angle to the skid 7 and the cased well 8 extends at the same angle into the seabed.
The details of the horizontally extending arrangement of conduit 5 A are shown in more detail in FIG. 2 and FIGS. 3A-3D and installation of the wellhead assembly will be described with reference to these drawings.
The first stage of the installation is to install the riser conduit 5 , which is, in this particular example, a well riser conduit, from the production installation 1 to the skid 7 , which is secured to the seabed 6 . This can be done in a number of ways. Firstly, as shown in FIG. 5, the skid 7 can be fixed to the end section of the riser conduit 5 at the production platform 1 . The riser conduit 5 is then run vertically from the production platform 1 and is maneuvered out towards the seabed target zone. When correctly positioned, the skid 7 is fixed to the seabed 6 . As a second method, as shown in FIG. 6, instead of running the riser conduit 5 vertically from the production installation 1 , the riser conduit 5 can be pre-made and can be horizontally towed to the desired location, where it is attached at one end to the production deck 1 . The riser conduit 5 is then positioned on the seabed 6 and the skid 7 is fixed to the seabed 6 . A third alternative, as shown in FIG. 7, can use an installation vessel 30 instead of a tension leg production installation deck 1 to position the skid 7 and run the drilling riser conduit 5 vertically to attach it to the skid 7 as shown in FIG. 3D, where skid 7 can be pre-installed on the seabed as previously described. The installation vessel 30 can then be moved across to the production platform 1 . The end of the riser conduit 5 is transferred from the installation vessel 30 and secured to the production platform 1 .
In order to attach the riser conduit to the skid 7 , the riser conduit 5 is connected to a wellhead 12 , which is held vertically and is pivotally attached to the skid 7 , as shown in FIG. 2 and FIG. 3B, about an axis 13 so as to be movable through an angle of 90°, as demonstrated by the arrow 14 . The wellhead has a swivel telescopic section 12 A, which is locked during the installation process at mid-stroke and is unlocked once the system is installed to allow for riser conduit twist and thermal expansion. This allows not only for the third installation method described. above where the wellhead 12 will initially have to be vertical, but also allows for the oblique riser conduit SE, as illustrated in FIG. 1 . The riser conduit 5 is landed within the wellhead 7 and is sealed by pressure seals 15 .
The next stage is to drill from the wellhead 12 into the seabed 6 and to install a conductor. Depending on the surface formation a hole can be drilled and a conductor can be installed, or the conductor 16 can be run with an internal shoe bit rotated by a drill string turbine. This latter arrangement can be used in order to drill through unconsolidated formations close to the surface of the seabed so that the conductor 16 supports the formation where a drilled hole would collapse during drilling. In the case of the riser conduit 5 B, the conductor 16 will follow the angle of the riser conduit into the seabed, while for the horizontal arrangement, as shown in FIGS. 2 and 3B, the conductor will initially be horizontal but will drop angle under gravity so that it continues obliquely downwardly through the seabed to the desired depth. The conductor 16 is provided with a stop which lands in the wellhead 12 at which point the internal shoe bit is removed and conventional drilling techniques can be used to install a intermediate string 17 , a production casing string 18 , both of which are landed and sealed within the wellhead 12 , and a liner or screens 10 .
The drilling elements can be provided with a system of rollers which may be driven in order to facilitate their rotation and passage down the riser conduit. It may even be useful to provide hydraulic force to the drilling or to the casing running systems to provide movement along the riser conduit S, particularly where the riser conduit has a long horizontal portion.
The appropriate tie back casings 19 , 20 are hung off at the production deck and landed within the wellhead 12 in a similar manner as for conventional vertical tieback wellheads.
The well completion tubing 21 is now run from the production installation all the way to the production formation. Alternatively, the completion tubing can be hung off in the wellhead 12 . The completion tubing can be provided with two surface control safety valves 22 , 23 .
By using the tie back strings and landing the production tubing in the wellhead 12 , it is possible to perform a disconnect operation above the wellhead 12 after the well is made safe. To facilitate reconnection, the skid can have a horizontal pipeline pull in system. Alternatively if it is envisaged that the conductor will never need to be disconnected the intermediate casing string and the production casing string can be run directly up to the production platform without landing in the skid wellhead 12 .
At the production deck, a BOP (not shown) is removed and a tree 24 of known construction is installed for production. In this case, a horizontal tree is shown which has the tubing run through it and landed in it.
A second example of an assembly is shown in FIG. 4 . The only difference between this assembly and that shown in FIG. 1 relates to the nature of the production installation. Instead of a tension leg production installation at the surface as shown in FIG. 1, the example of FIG. 4 has a tension leg subsurface platform 25 which is positioned at a relatively short distance below the surface 2 and connected to a mobile drilling vessel 26 by a short drilling riser 27 . The mobile drilling vessel can be moved between wellheads 28 together with a drilling BOP 29 and can thus be used to drill a number of wells. In this case, the drilling riser is vertical at the subsurface platform 25 . | A method of drilling an offshore underwater well comprising the steps of installing a riser conduit so that it is substantially vertically supported at a production deck. The riser conduit deviates progressively further from the vertical with increasing sea depth, so that its end can be anchored at the seabed by a skid either at an oblique angle so that drilling into the seabed can be carried out at the oblique angle, or horizontally, so that the riser conduit can extend some considerable distance across the seabed before drilling is carried out. | 4 |
REFERENCE TO RELATED APPLICATION
[0001] This application claims the benefit U.S. Provisional Application No. 60/691,961, filed Jun. 17, 2005, and entitled “Apparatuses and methods for determining and locating wiring intermittence shorts, wiring intermittence opens, the ability of wires to carry a load and determining the distance to shorted or broken wires within a multi strands wire harness, by providing the individual discrete wires within the harness the characteristics and qualities of a coaxial cable.”
BACKGROUND OF THE INVENTION
[0002] 1. Field of the Invention
[0003] The present invention relates to testing equipment for electrical wiring. More specifically, the invention relates to an apparatus and method for testing a wiring harness for intermittent shorts and breaks (opens), and the ability of the wires therein to carry a desired amount of current.
[0004] 2. Background of the Invention
[0005] There are few effective systems for troubleshooting wiring harnesses. Most such systems currently in use are both extremely expensive and complex, designed to be utilized by at least two technicians positioned at either end of the wiring harness under investigation.
[0006] Intermittence problems account for close to 90% of wiring problems within aircraft, and are caused by aging wiring, wear and tear, and vibrations. Finding intermittent problems are very difficult because it may be present during the flight but not on the ground. Extensive discussions with aircraft manufacturers and aircraft maintenance companies confirm the aviation industries challenge with intermittence problems.
[0007] The current procedure involves technicians attempting to solve intermittence problems by using an ohmmeter, checking two wires at a time. By touching the wire bundles, the problem may temporarily disappear and not detected. These problems are difficult to find and may take a very long time to be detected. In a wiring harness that contains 50 wires, to find a broken wire, it may take up to 50 tests, one wire at a time. In the same harness, to find a short between 2 wires, it may take up to 1225 tests, since each wire has to be tested against the rest. In a case of intermittent problem, the tests need to be repeated constantly until the failure occurs.
[0008] The current invention, not only perform this process automatically and fast, but also assist the technician in finding the actual location of the fault.
SUMMARY OF THE INVENTION
[0009] It is an object of the present invention to provide a novel piece of equipment and method for determining and pointing to the location of wiring intermittence shorts.
[0010] It is another object of the present invention to determine and locate wiring intermittence open.
[0011] It is another object of the present invention to determine corrosion of contacts and pointing to the location of the corroded contacts by checking the ability of the wire to carry a load.
[0012] It is another object of the present invention to determining the distance to shorted or broken wires within a multi wire harness, by providing the individual discrete wires within the harness the characteristics and qualities of a coaxial cable and using Time-domain Reflectometer principles.
[0013] It is another object of the present invention to provide a novel piece of equipment and method to provide an expansion unit to be used with a standard TDR that normally connects and test two wires only. A TDR (Time-Domain Reflectometer), typically measures distance to a short or a break in coaxial cable. The present invention will allow the standard TDR to be used not only for coaxial cables, but also for testing wire harnesses made of large number of discrete wires. In addition to finding the distance to shorts and opens in these discrete wires, the present invention will also communicate with a PC or a laptop to store the test results and display the expected length values of the wires under test.
[0014] The present invention provides an easy-to-use test system capable of troubleshooting several different types of faults within a wiring harness, such as intermittence and corrosion. In addition it can find the distance to the fault and pinpoint to the exact location of the problem.
[0015] The TDR Expansion Unit allows the test of multiple-wire harness using the TDR (Time-Domain Reflectometer) principles. The innovating method provides the characteristics and qualities of a coaxial cable to a multi-wire harness that is made of single wires. This method can be applied to a TDR Expansion system or be used as part of the TDR itself, allowing it to test wiring harnesses made of regular discrete wires. In addition to a stand-alone test system as described above, by providing the qualities of a coax cable to a multi-wire harness made of individual single wires, this method can be used to improve upon the use of an existing TDR system. A typical TDR test system connects and tests only one pair of wires at a time. The present invention allows the connection and test of multi-wire harness that is made of individual single wires.
[0016] The method described will provide coaxial characteristics to a wiring harness made of discrete wires. It can then be used as an expansion unit for a standard TDR, or it can be incorporated within the standard TDR to allow it to test a wiring harness made of discrete wires.
[0017] The corrosion unit allows for troubleshooting and determining the quality of the electrical connections made by contacts of connectors and splices within the wiring harness. Bad connections, bad crimps of connector pins, and splices, may be caused by the use of wrong tools, wear and tear, and corrosion, and account for a majority of all wiring problems. Bad contacts may cause intermittence problems, when due to vibrations; a contact may be present for a period of time and disappear a moment later. In addition, a bad contact may limit the amount of current the wire can carry, which will result in excessive voltage drop on the faulty contact. In this case, the component connected to the other side of the harness will not receive the voltage level it requires, and the system may not operate correctly.
[0018] The apparatus consists of two portable units: (i) Unit A connects to one side of the harness, via connecting pins; (ii) Unit B connects to the other side of the harness, via connecting pins; and optional wireless headphones, receiving test results transmitted by the unit A voice module.
[0019] Each apparatus safely tests the cable or wiring harness in question. When testing a wire harness inside an aircraft, two sides of the harness under test are disconnected from their respective LRU (Line Replacement Unit—an aircraft system) and are connected to test Unit A and test Unit B. The apparatus test units use isolated power sources and isolated return connections.
[0020] During new wiring installation or wiring modifications on aircraft, wires are checked for continuity between the wires and their connectors. Typically an ohmmeter is used to “ring out” the wires. This type of test shows that the wires are connected, but it does not provide any indication for the quality of the connections. Many times the wires do not reveal a problem when tested with the ohmmeter, but they fail when the actual system is connected and powered up. Currently, technicians attempt to detect failures caused by low quality connections and crimping, by connecting a light bulb to the suspected wire and observing the intensity of the light.
[0021] The load apparatus consists of two portable, battery-operated units. One unit connects to one end of the harness; the other unit connects to the other end of the harness. The units control and monitor up to 128 wires for the ability of each wire to carry a load, adjustable by the user, up to 5 Amperes. It can be upgraded to provide even more current. The tester monitors the amount of current flowing in the wire, as well as the amount of voltage loss on the wire, thereby reflecting the quality of the wire and the connections, such as connectors and splices, and alerts the user by producing a fault condition. The user can test the wires by manually advancing to the next wire and observing the results of pass or fail, or setting the tester to the “Auto Mode” and “Stop On Fail,” which will automatically test the wires, and stop when a failure is found. This information may also be displayed on a hand-held unit, via wireless communication. This will allow the user to inspect the harness at its full length, wiggle it at any suspected location, and view the results on either the receiving unit or the portable hand held unit.
[0022] Another use of the current invention is during new wiring installations or wiring modifications. Typically wires are checked for continuity by two technicians using an Ohmmeter to “ring out” the wires. This type of test shows that the wires are connected, but it does not provide any indication for the quality of the connections. Many time the wires do not reveal a problem when tested with an Ohmmeter, but they fail when the actual system is connected and powered up.
[0023] Because the present invention provides high current to the wires under test, the version used in the system described in FIG. 1 is limited to one wire only to eliminate the possibility of providing high currents to a harness installed inside the aircraft, and may be still connected to the LRU, even though, the system is using isolated return. This fact may also reduce the liability insurance the user may need to carry. For other applications, when a harness is being built outside of the aircraft, a full 128-wire embodiment may be used.
BRIEF DESCRIPTION OF THE DRAWINGS
[0024] The present invention, as well as further objects and features thereof, are more clearly and fully set forth in the following description of the preferred embodiment, which should be read with reference to the accompanying drawings, wherein:
[0025] FIG. 1 is a top view of the preferred embodiment;
[0026] FIG. 2 is a flowchart of the process of determining and locating wiring intermittence shorts of the preferred embodiment;
[0027] FIG. 3 is a flowchart of the process of determining and locating wiring intermittence opens of the preferred embodiment;
[0028] FIG. 4 is a flowchart of the process of determining and locating wiring corrosion of the preferred embodiment;
[0029] FIG. 5 is a flowchart of the process of applying coaxial characteristics to wiring harnesses made of individual wires used in the preferred embodiment;
[0030] FIG. 6 through FIG. 9 are the electronic schematic of intermittence section of the preferred embodiment;
[0031] FIG. 10 through FIG. 11 are the electronic schematic of corrosion section of the preferred embodiment;
[0032] FIG. 12 through FIG. 15 are the electronic schematic of TDR Expansion section of the preferred embodiment;
[0033] FIG. 16 is a schematic block diagram showing the arrangement and function of the various hardware components of the Intermittence part of the current invention;
[0034] FIG. 17 is a schematic block diagram showing the arrangement and function of the various hardware components of the TDR Expansion part of the current invention; and
[0035] FIG. 18 is a schematic block diagram showing the arrangement and function of the various hardware components of the Corrosion part of the current invention.
DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENT
[0036] FIG. 1 illustrates the preferred embodiment of the present invention. The testing unit ( 13 ) is divided into four subsystems (A, B, C, D). Subsystem (A) is the “INTERMITTENCE.” It contains the circuitry, the controls and the display. It uses a combination of hardware and software to test and find the location of intermittence in a wire within a wiring harness. The wiring harness connects to Subsystem (A) connectors ( 6 ). The power switch ( 7 ) provides the external power ( 27 ), or the internal battery power. The operator uses four control buttons: LIST, LOOP, INTERMITTENCE, EXIT ( 8 ). The LIST control button displays all shorts or opens between the wires. The LOOP control button automatically repeats the test and displays the shorts or opens as they are detected. The INTERMITTENCE control button registers and displays an intermittent short or open. The EXIT button exits the mode of operation. When a control button is pressed for less than two seconds, this Subsystem tests for shorts, when a control button is pressed for more than 2 seconds, this Subsystem is testing for opens. The test results are displayed on the LCD display ( 3 ) and on yellow LED ( 2 ) and red LED ( 4 ). When the user is in INTERMITTENCE mode shorts, the tester is testing all wires for any temporary shorts between the wires. Once a short between two wires is found, the Subsystem displays the 2 wires on the LCD display ( 3 ), and the red LED ( 4 ) turns on. The user then can move and wiggle the harness. As soon as the temporary short disappears, the red LED ( 4 ) turns off and the yellow LED ( 2 ) turns on. The location that cause the LED's to switch colors is the location of the intermittence. The results can be printed using the built in printer ( 31 ) by pressing the print button ( 1 ).
[0037] Subsystem (B) is the TDR EXPANSION unit, which contains the circuitry, the controls and the display. It uses a combination of hardware and software to expand the capabilities of a conventional TDR by increasing the number of wires it can test. Typically, the Conventional TDR can test only 2 wires, usually a coaxial cable or a twisted-pair. The harness under test connects to connector ( 10 ). The output of the Subsystem is a BNC connector ( 9 ), which connects to the BNC input connector of external TDR, using a short coaxial cable. The wiring harness connects to Subsystem (B) connectors ( 10 ). The power switch ( 12 ) provides the external power ( 27 ), or the internal battery power. The operator uses 4 control buttons: AUTO, NEXT, BACK, EXIT ( 14 ). The AUTO control button checks for any shorts between the wires and displays the shorted wires on the LCD display ( 15 ). The external TDR will show the distance to the short. If there are no shorts, it automatically selects one wire at a time, and displays the length of each wire or the distance to the ‘open.’ The wires ID numbers are displayed on the LCD screen ( 15 ), the length results are displayed on the external TDR. The NEXT control button selects the next wire to be tested. The BACK control button selects the previous wire to be tested. The EXIT button exits the mode of operation. The results displayed on the LCD display ( 15 ) can be printed using the built in printer ( 31 ) and by pressing the print button ( 16 ).
[0038] Subsystem (C) is the “CORROSION.” It contains the circuitry, the controls and the display. It uses a combination of hardware and software to test a wire for corrosion and corroded contacts by its ability to carry current. The Subsystem detects a loss due to corroded contact. In addition to the display of current on the LCD ( 26 ), a bright white LED ( 21 ) provides a visual indication of the quality of the contacts. The power switch ( 18 ) provides the external power ( 27 ), or the internal battery power. The wire under test connects between the OUT jack and FLOATING COM jacks ( 25 ). The OUT jack connects to one side of the wire; the other side of the wire connects to the FLOATING COM jack, via a dedicated ‘return’ wire, provides a ‘floating’ return which creates an isolated close circuit, adding to the safety of the test. The SET CURRENT knob ( 22 ) allows the user to adjust the amount of current that will flow in the wire, the TEST button ( 23 ) needs to be pressed during the test, and the white LED ( 21 ) provides a visual indication of the quality of the contacts. Subsystem (C) also includes a VOLTAGE TEST section, which allows testing the voltage on each of the 32 wires connected into the Sub-D connector ( 20 ). The operator uses two control buttons ( 19 ) to select the wire to be tested. The NEXT control button selects the next wire to be tested; the BACK control button selects the previous wire to be tested. A standard DMM can connect to the COM and OUT jacks ( 19 ). As the user selects the wire, the wire number is displayed on the LCD DISPLAY ( 26 ).
[0039] Subsystem (D) includes the external power source and battery charger jack ( 27 ), the low power indication in a form of red LED ( 28 ), a fuse ( 29 ), and a voice switch ( 30 ). By switching the voice switch to the ON position the Subsystem will announce the test results in a human voice. To the right of the voice switch ( 30 ), a jack allows the connection to a wireless transmitter capable of transmitting the test result messages to wireless headphones. The user can walk along the harness, wiggle and flex the harness in different locations, listen to the test results and the point that cause the test results to change (for example from short to open or from corrosion pass to corrosion fail) is the exact location of the fault. In addition to the above controls, section (D) also includes a printer which allows the printouts of all desired test results.
[0040] FIG. 2 is a flowchart of the process of determining and locating wiring intermittence shorts of the preferred embodiment. The system control unit, via the interface card, ( FIG. 16 ) sends a command to the driver/sensor card ( FIG. 16 ) to select two wires. The interface card gets a voltage level from the Driver card which corresponds to the status of the two wires (shorts or open). The system compares the voltage level to a set reference value, and determines whether there is a short between the two wires or not. The process continues, each time with different wires, until a short is found. The display then shows the two wires, and the red LED turns ON. The system keeps monitoring these two wires only, and when the short disappears, the red LED turns OFF, and the yellow LED turns ON. This allows the user to inspect the harness at its full length, wiggle it and flax it until the red LED and the yellow LED's are turning ON and OFF. The user then knows the exact location of the intermittence.
[0041] The process of finding opens intermittence is shown in FIG. 3 . It is similar process to finding shorts, as described in FIG. 2 , only in this case the other end of the harness is terminated with 1 k resistors to GND, and the system searches for opens instead of shorts.
[0042] The hardware of the system of the present invention consists of two primary components: the System Control unit and the Driver card ( FIG. 16 ), which comprise means for selecting a pair of wires of the harness and means for determining whether a short is present between the selected pair. The System Control unit includes the microprocessor, its built-in memory, the circuitry for the display, the control buttons, and the Interface card which controls the Driver card, which comprise means for providing a known voltage to one wire of the pair of wires, means for measuring a voltage to the other wire of the pair of wires, and means for comparing the measured voltage to the provided voltage.
[0043] The system control unit, via the interface card, ( FIG. 16 ) sends a command to the driver card ( FIG. 16 ) to select two wires. The interface card gets a voltage level from the Driver card which corresponds to the status of the two wires (shorted or open). The system compares the voltage level to a set reference value, and determines whether there is a short between the two wires. The system then displays the results, which comprises means for indicating visually the wires between which a short has been detected, and turn ON the appropriate LED, which comprises means for locating the short along the wire harness, and further comprises a first means for causing a first result when the selected pair of wires are determined to be shorted and a second means for causing a second result that is different from the first result when the selected pair of wires is determined to be not shorted.
[0044] Reference is made to FIG. 6 through FIG. 9 for a description of electronic components of the present invention and, more specifically, components comprising means for selecting a pair of wires from the harness and means for determining whether a short is present. As shown by FIG. 6 , U 1 is the microprocessor which controls the display, the control buttons, and senses the output level of the comparator, U 2 . U 2 compares the level of the signal from the driver card to a reference voltage, and makes decision if the wires under test are shorted or opened. U 3 is a voltage regulator. It provides a reference voltage to the comparator U 2 . U 4 controls the power to the circuitry; it protects the internal battery life by turning the power off when the battery voltage is too low. As shown in FIG. 7 , U 39 buffers the signals going into U 17 . U 17 contains logic circuitry which interfaces with the Driver card and selects the wires to be tested. As shown by FIGS. 8 and 9 , U 1 -U 8 , U 21 -U 28 are multiplexers IC's, which are connected to the wire harness under test. These IC's are arranged in two groups as shown in FIGS. 8 and 9 : Rail A and Rail B. One driver card is needed to select 128 wires.
[0045] FIG. 5 illustrates a method of testing a multi-wire harness using TDR principles. The wire harness, made of individual single wires, connects to one of the connectors of the test system. The test system tests one wire at a time by sending a signal to the wire under test. The test system selects the wires that are not under test and are not shorted to the wire under test, and uses them as a return for the signal that was sent to the wire under test. These wires that are selected as return, are shorted together by the system, and become one large shield that surrounds the wire under test and provide qualities similar to a shield in a coax cable.
[0046] By providing a shield effect to a wire harness that is made of single wires, the impedance between the wire under test and the surrounding wires is more even, and the velocity factor is more uniform, spreads more evenly along the length of the harness, therefore each wire can be tested more accurately, and show a more distinctive waveform on the test system LCD display. The test system evaluates the waveform and provides a digital value, representing the length of the wire under test. The test system can also perform shorts tests. It provides the results as shorts list and also displays the distance to the short. In the event of a short, the test system uses only the shorted wires as a signal return.
[0047] The hardware of the system of the present invention consists of two primary components: the System Control Unit and the Relays card ( FIG. 17 ). The System Control unit includes the microprocessor, its built-in memory, the circuitry for the display, the control buttons, and the Interface card which controls the Relays card. The system control unit, via the interface card, ( FIG. 17 ) sends a command to the driver card ( FIG. 17 ) to select two wires, one from the group of Rail A, and the second from the group of Rail B The interface card gets a voltage level from the Driver card which corresponds to the status of the two wires (shorts or open). The system compares the voltage level to a set reference value, and determines whether there is a short between the two wires. As described in the flowchart of FIG. 5 , when the first short is found, the two wires names are displayed; the first wire, from the group of Rail A, is directed to the center of the BNC plug of the external TDR, the second wire, from the group of Rail B is directed to the body (shield) of the BNC plug of the external TDR. When no shorts are found, the system, as described in the flowchart of FIG. 5 , connects the wire from the group of Rail A to the center BNC plug of the external TDR, and it shorts all Rail B wires together and connects them to the body (shield) of the BNC plug of the external TDR.
[0048] Reference is made to FIG. 12 through FIG. 15 for a description of the electronic components of the present invention. As shown by FIG. 12 , U 6 is the microprocessor which controls the display, the control buttons, and senses the output level of the comparator, U 9 , and which comprises means for selecting a wire from the harness for testing, means for testing the remaining wires of the harness for a shorted wire until either a shorted wire is found or until all remaining wires have been tested, means for calculating the distance to the short or open in the selected wire, and means for providing an electrical pulse to the selected wire using either a shorted wire or all remaining wires as a return. U 9 compares the level of the signal from the Relay card to a reference voltage, and determines if the wires under test are shorted or opened. U 4 is a 1 ns programmable delay line which in conjunction with U 1 driver chip, U 5 digital-to-analog converter chip, U 2 fast comparator chip and U 3 which contains logic circuitry, are providing the ability to check the time in nanoseconds between the main pulse sent via U 1 and the reflected pulse arriving at pin 2 of the U 2 comparator, thus comprising means for measuring the delay value between the electrical pulse and any reflected signal. Because the software controls the amount of delay (in Ins steps), when there is a match between the reflected pulse and the delayed pulse, the systems knows the exact delay that was selected for that match. The value of the delay is the time between the main pulse and the reflected pulse. U 20 is a voltage regulator, providing reference voltage to U 5 . U 5 is a programmable analog/digital IC, the output of which is fed into the reference input of U 2 , the fast comparator, providing a method to measure the voltage of the signal arriving at pin 1 of U 2 at 1 ns intervals. The voltage and time information are used to plot the waveform of the signal going through wire and of course, the reflection. U 7 , MAX232 allows serial communication between the Microprocessor U 6 and a PC serial port, U 10 expands the number of I/O U 6 can handle, U 11 is additional memory for U 6 , the Microprocessor. U 8 and U 12 controls the power to the circuitry; U 8 is 5 V voltage regulator, U 12 protects the internal battery life by turning the power off when the battery voltage is too low.
[0049] As shown by FIG. 13 , U 6 contains logic circuitry comprising a first means for electrically connecting the selected wire to the center pin of an RF connector and a second means for electrically connecting the shorted wire or all remaining wires to the shield of the RF connector, which allows the selection of Rail A wires and rail B wires at the Relay cards. U 7 through U 10 are buffers, their outputs connect to the relays at the Relay cards. As shown by FIG. 14 , K 1 through K 37 are the relays for Rail A. Each relay connects to a wire. Each wire connects to a relay of Rail A board and a relay at Rail B board, so for example, wire 1 of the harness will connect to Relay K 1 of Rail A board, and relay K 1 of rail B board.
[0050] As shown by FIG. 15 , K 1 through K 37 are the relays for Rail B. Each relay connects to a wire. Each wire connects to a relay of Rail A board and a relay at Rail B board, so for example, wire 1 of the harness will connect to Relay K 1 of Rail A board, and relay K 1 of rail B board.
[0051] Reference is made to FIG. 4 for a description of the method for testing multiple wires for corrosion. The system control unit, via the interface card, ( FIG. 18 ) sends a command to the Power FET's card ( FIG. 18 ) to select two wires. The interface card provides a selected amount current as selected by the user and applies it to the selected wire. The system senses the output of a comparator which indicates the amount of current flowing through the wire. A comparator output HIGH indicates that the amount of current flowing through the wire exceeds the minimum set reference. In this case, the next wire will be selected. When the output of the comparator is low, it indicates a current loss, and the failed wire is displayed. The user can then wiggle and flex the wire, and view the display for a pass/fail changes. The physical location of the harness that cause the changes of Pass and Fail on the display, is the physical location of the corrosion problem. When flexing the harness while the red LED and the yellow LEDs are turning ON and OFF, the user knows the exact location of the intermittence.
[0052] FIG. 18 shows the hardware of the system of the present invention, which comprises two primary components: the system control unit and the POWER FET card. The system control unit includes the microprocessor, its built-in memory, the circuitry for the display, the control buttons, and the Interface card which controls the POWER FET card. The system control unit, via the interface card, sends a command to the POWER FET card to select one wire. Upon the selection of the wire the current source connect to one side of the wire; the other side of the wire connects to the isolated return wire. Once there is a current flow through the wire, the amount is displayed on a current meter, as well as the voltage drop on the wire if desired by the user. Reference is made to FIG. 10 through FIG. 11 for a description of the electronic components of the present invention. The present invention can test for corrosion 128 wires or more, the circuitry used for FIG. 1 C is limited to one wire only. As shown in FIG. 10 , U 7 is the microprocessor which controls the display, the control buttons, and senses the output level of the comparator, U 3 . U 3 compares the level of a voltage that is related to the amount of current flowing through the wire (a voltage drop on 1 ohm resistor) a reference voltage, set by the user as a minimum accepted current flow. U 9 is the LCD display, U 1 A is an operational amplifier, U 1 B as a voltage follower capable of measuring the voltage drop loss on the wire under test. U 2 A is a low voltage indicator, pin 2 connects to a reference voltage. U 5 is an 8-channel Analog to Digital IC, allows the replacement of an actual Meter for displaying the results. The Microprocessor U 7 can read the measured value and display it on the LCD screen. U 11 is an optional temperature sensor to compensate for current readings affected by temperature. U 8 is a reset IC, connected to the Reset input of the microprocessor U 7 , it adds to the stability of U 7 .
[0000] U 6 is a MAX232 IC, allows the serial communication with a PC or a laptop.
[0053] As shown in FIG. 11 , U 1 contains the logic for selecting the wire to be tested. U 2 , U 3 , U 6 , U 7 are 74HCT244 buffers that connect to the gates of the FET's Q 1 through Q 32 . U 4 , U 5 , U 8 , U 9 are 74HCT244 buffers that connect to the LED's for PASS/FAIL indication. FET Q 1 through FET Q 32 are turned on one at a time by program control, each FET is connected to one of the wires under test through its Source. When a wire is selected to be tested, its FET turns on, the Source and Drain are getting shorted, and the selected wire is connected to the current source.
[0054] The present invention is described above in terms of preferred illustrative embodiments in which a system for testing wiring characteristics is described. Those skilled in the art will recognize that alternative constructions can be used in carrying out the present invention. Other aspects, features, and advantages of the present invention may be obtained from a study of this disclosure and the drawings, along with the appended claims. | The invention comprises, inter alia, a portable and easy to use tester for troubleshooting and determining the location of wiring intermittence shorts and wiring intermittence opens. The tester can also check the wire ability to carry a load and detect corrosion and bad contacts. Finally, the invention provides a method to apply the characteristics and qualities of a coaxial cable, to a regular, discrete, multi-wire harness. This method will improve the functionality of a conventional Time-Domain Reflectometer (TDR) system that typically can test only two wires at a time, connected to its input. By providing regular wires the characteristics and qualities of a coaxial cable this method will allow the creation of an expansion box that can interface to a conventional TDR system, and increase the number of wires it can test. | 6 |
This application is a Continuation-in-Part of application Ser. No. 12/462,696 filed Aug. 6, 2009 now abandoned.
FIELD OF THE INVENTION
The present invention relates to improvements in syringes and in particular, relates to an improved syringe wherein two or more substances are mixed and also to a method for the mixing of two or more substances in a syringe.
BACKGROUND OF THE INVENTION
In pharmaceutical delivery systems, it is often required that a drug in powder form be mixed with a diluent in order to be able to deliver the drug to a patient. To date, this is frequently done by injecting the diluent into a vial containing the powder drug, mixing the drug with the diluent and then aspirating the drug in fluid form into a syringe for subsequent injection into the patient. A manual mixing such as this can be cumbersome and inconvenient and can also lead to wastage of some of the drug which may remain in the vial.
Other more automated systems for mixing the drug and diluent have been developed and are shown in U.S. Pat. Nos. 5,817,055 and 5,716,338. In these patents, the mixing of the drug and diluent is achieved in what is known as a by-pass syringe having two compartments; one containing the drug and the other the diluent.
These devices have been used for many years to aseptically package lyophilized or “freeze-dried” medications together with their diluents. In recent years specially coated drug micro-units have been produced in the form of microspheres which release slowly into the bloodstream when administered are also now being packaged in these devices. The packaging of lyophilized drugs requires that the liquid drug admixture be filled into the top chamber so that once frozen, all water will sublimate under vacuum leaving a dried cake of residual drug product. For this reason an aqueous diluent needs to be filled in the lower chamber of the syringe after the freeze drying cycle. The production of powdered products such as microspheres requires that the diluent be filled in the lower chamber first followed by powder filling in the upper chamber. This will ensure that the diluent is well sealed before entering the well isolated powder-filling environment where unwanted powder contamination is a concern.
The preparation for administration in these double chamber by-pass syringes however is much the same and requires that the device always be held vertically with the exit nozzle pointing upwards. The mixing action occurs when the rear plunger is pushed forward very slowly. This movement can be dampened by using a threaded plunger rod so that the user must screw the rod thereby providing a slow controlled upward movement of the rear plunger. This movement moves the entire diluent including the upper plunger upwards into the by-pass area (any fast uncontrolled movement would move the plunger beyond the by-pass area and block flow of the diluent). Continued slow upward movement will cause all of the diluent to flow through the by-pass around the upper plunger and into the upper chamber mixing with drug component and expelling some of the air above it.
At this point the user must stop pressure on the plunger rod and begin swirling or shaking the syringe to ensure dissolution or suspension of the drug. If either component of the admixture contains a surface active agent to promote wetting then excessive foaming can be a problem as well as the problem of entrained air bubbles. After some time and when the admixture is suitably mixed, and foam or bubbles have been allowed to dissipate, then the user can slowly push the plunger rod to expel the air above the drug surface, attach a needle and inject the medication.
Quite apart from the above, there may also be a requirement to remix a mixture which has separated out and needs to be transferred to a syringe type structure.
SUMMARY OF THE INVENTION
It is an object of the present invention to provide a by-pass type syringe which has a venting structure to permit the expelling of air therefrom.
It is a further object of the present invention to provide a syringe wherein mixing is accomplished by passing the components back and forth through a relatively small opening to subject the mixture to a shearing action.
It is a further object of the present invention to provide a method for mixing two substances in a syringe structure.
According to one aspect of the present invention, there is provided a transfer and mixing device comprising an outer housing, a by-pass cartridge having a by-pass formed therein, the by-pass cartridge being mounted within the outer housing, a septum located at a front end of the by-pass cartridge, a first plunger located at a rear end of the by-pass cartridge, a second plunger located intermediate the septum and the first plunger, the second plunger being located rearwardly of the by-pass, a syringe socket at a front end of the outer housing, the syringe socket including a piercing member extending inwardly towards the septum, a syringe securable to the syringe socket, a syringe plunger mounted in the syringe, the syringe plunger having a fluid passageway therein, a hydrophobic membrane covering the passageway, the passageway thereby permitting the passage of gas therethrough, and a plunger rod.
According to a further aspect of the invention, there is provided a method of mixing a pharmaceutical mixture contained within a container, the container having a plunger located proximate a rear end thereof and a fluid outlet located at a front end thereof, the method comprising the steps of providing a syringe, the syringe having a syringe plunger, a fluid passageway extending through the plunger, and a hydrophobic membrane extending across the fluid passageway, pushing the plunger of the container to cause the mixture therein to pass through a bore communicating with the syringe plunger such that air is expelled through the hydrophobic membrane, and the mixture passes into the syringe, and subsequently pushing the syringe plunger such that the mixture passes back through the bore extending between the fluid passageway and the container, the bore being sized to provide a mixing action to the pharmaceutical mixture passing therethrough.
According to a still further aspect of the invention, there is provided a method of transferring and mixing a pharmaceutical mixture, the method comprising the steps of supplying a first device comprising an outer housing, a by-pass cartridge having a by-pass formed therein, the by-pass cartridge being mounted within the outer housing, a septum located at a front end of the by-pass cartridge, a first plunger located at a rear end of the by-pass cartridge, a second plunger located intermediate the septum and the first plunger, the second plunger being located rearwardly of the by-pass, a syringe socket at a front end of the outer housing, the syringe socket including a piercing member extending inwardly towards the septum, a first compartment having a pharmaceutical substance therein being defined between the septum and the second plunger, a second compartment having a diluent therein being defined between the first and second plungers, securing a syringe to the syringe socket, the syringe having a syringe plunger mounted therein, the syringe plunger having a fluid passageway therein, a hydrophobic membrane covering the passage, the hydrophobic membrane permitting the passage of gas therethrough, securing a plunger rod to the first plunger at the rear end of the by-pass cartridge, advancing the first plunger to thereby cause the second plunger to move to the by-pass and permit the diluent in the second compartment to mix with the substance in the first compartment to thereby form a mixture, exerting a continued pressure on the plunger rod to cause air to advance from the first compartment to the syringe and through the hydrophobic membrane, exerting a continuing pressure on the plunger rod such that the mixture from the first compartment passes through the piercing member into the syringe, and using a plunger to move the syringe plunger to retransfer the mixture into the first compartment of the by-pass cartridge.
As used herein, the term “container” includes any type of vessel having a cavity therein designed to receive one or more substances. Generally, the container will have an inlet/outlet at opposed ends thereof. The word container will thus include, in the preferred embodiments, various types of syringes and/or cartridges.
Also, as used herein, the term “mixture” will refer to the combination of two or more ingredients, the combination being in the form of a mixture, suspension, admixture, solution, emulsification, etc. In the preferred embodiments, the mixture of the present invention will be a suspension of microspheres and a diluent.
The by-pass cartridge referred to above may be any suitable type of by-pass cartridge which is well-known in the art. Thus, various types of by-pass cartridges have been employed including those having multiple by-passes.
A device for transferring a diluent to a dry pharmaceutical component by means of a by-pass cartridge is well known. Generally, the device will include plungers which form two different storage compartments. A centrally located plunger usually divides the dry pharmaceutical component in the front of the by-pass cartridge and a diluent or liquid component in the rear compartment. A pressure is exerted on a plunger (typically by attachment of a plunger rod thereto) and the rearward plunger is advanced forwardly which will cause pressure to be exerted on the centrally located plunger which will then advance to the location where the diluent can transfer to the front compartment for mixing with the dry pharmaceutical component.
One problem which can arise is that the rear plunger is advanced too rapidly such that it will “overshoot” the by-pass formed in the cartridge and thus render it impossible for the diluent to reach the front compartment. It has been proposed in the art to use a screwthreaded motion to slow down the advancement to overcome this problem.
In one aspect of the present invention, there is provided a rack and pinion arrangement which will also achieve a greater control over advancement of the plungers. This arrangement, as will be discussed in greater detail hereinbelow, permits the operator to exert a slow even force on the plungers such that the centrally located plunger will advance to the by-pass area in a controlled fashion.
In one aspect of the present invention, there is provided an activation cap which permits the by-pass cartridge to be advanced such that it will be pierced by a piercing member located at the front end of the outer housing. This piercing member will include a bore extending therethrough such that a fluid passageway extends from interiorly of the by-pass cartridge through the syringe.
The syringe which is securable to the syringe socket may do so by means of a luer fitting which is well-known in the art. The syringe includes a plunger therein with the plunger preferably located at the front end of the syringe. The plunger is characterized by having a fluid passageway therethrough, with the fluid passageway having a hydrophobic membrane therein. The hydrophobic membrane may be formed of any suitable material such as a polytetrafluoroethylene (PTFE) or Tyvec or similar materials such as PFA, PFEP, PVDA, polysulfone, nylon, etc. Such hydrophobic membranes permit the passage of air therethrough while it has been found that even with moderate pressure on the hydrophobic material, liquid will not pass therethrough while the air within the compartment is expelled.
Thus, there is provided a mixing wherein frothing or the entrainment of air bubbles within the liquid is prevented.
Naturally, it will be understood that other venting structures may be employed if so desired. Thus, one could provide a venting structure on one of the walls defining the mixing compartment.
Preferably, the syringe plunger will not have means for accepting attachment to a plunger rod, though the plunger rod will be utilized. This will prevent any reverse pressure or aspiration which would permit the entry of air into the mixing compartments.
According to the method of one embodiment of the present invention, the first plunger located at the rear end of the by-pass cartridge has a plunger rod attached thereto. Subsequently, the diluent from the rear compartment is advanced through the by-pass to the front compartment where the two components are mixed together. Air will still occupy the upper portion of the first compartment.
Subsequently, the mixture is transferred through the piercing member into the syringe. Continued advancement of the plungers in the by-pass cartridge will cause the mixture to advance into the syringe. Air above the mixture will be expelled through the hydrophobic membrane. As a result, an airless mixture is achieved.
Subsequently, the mixture now free of air can be transferred back into the front compartment of the by-pass cartridge and the mixture will undergo a “shearing” action when passing through the passageway within the piercing member. This continued transfer from the by-pass cartridge to the syringe can be continued until the desired homogeneity of the mixture or suspension is achieved.
The shearing action is only accomplished due to the narrow opening in the piercing member. Preferably, the opening or internal diameter of the piercing member is less than fifty thou (mil). Even more preferably, the internal diameter is preferably less than 42 thou and even more preferably, is equal to or less than 21 thou.
BRIEF DESCRIPTION OF THE DRAWINGS
Having thus generally described the invention, reference will be made to the accompanying drawings, in which:
FIG. 1 is a cross-sectional view of the transfer and mixing assembly according to one embodiment of the present invention;
FIG. 2 is an exploded view thereof;
FIGS. 3A to 3C show different configurations, in cross-sections, of plungers having a hydrophobic membrane;
FIG. 4 is a cross-sectional view of a further embodiment of the present invention;
FIG. 5 is a cross-sectional view illustrating a still further embodiment of the assembly of the present invention;
FIG. 6 is a cross-sectional view illustrating a still further embodiment of the transfer and mixing assembly; and
FIG. 7 is a sectional view of a front cap having a breathable portion thereon.
DETAILED DESCRIPTION OF THE INVENTION
Referring to the drawings in greater detail and by reference characters thereto, there is illustrated a mixing and transfer assembly generally designated by reference numeral 10 .
Transfer and mixing assembly 10 includes a by-pass cartridge generally designated by reference numeral 12 , an outer housing about by-pass cartridge 12 and generally designated by reference numeral 14 , an activation cap 16 , a plunger rod 18 , a syringe 20 and a syringe plunger rod 22 .
By-pass cartridge 12 has an outer wall 26 with a by-pass 28 formed therein as is known in the art. A septum 30 covers the outlet of by-pass cartridge 12 and a cap 32 extends thereover.
Mounted within by-pass cartridge 12 is a rear plunger 34 which has a female luer fitting 36 . An intermediate or middle plunger 38 is situated rearwardly of by-pass 28 . There is thus formed a rear compartment 40 which is defined as the space between wall 26 , rear plunger 34 and intermediate plunger 38 . A front compartment 42 is defined by wall 26 , intermediate plunger 38 and septum 30 . For most uses, rear compartment 40 will contain the diluent while a front compartment 42 will contain the dry and active pharmaceutical Component.
Plunger rod 18 includes a head 46 for ease in pushing on shaft 48 . Shaft 48 is provided with a male luer fitting 50 designed to engage with luer fitting 36 on rear plunger 34 .
Outer housing 54 surrounds and supports by-pass cartridge 12 and includes a side wall 54 and a top wall 56 . A piercing member 58 has a bore 60 extending therethrough while an upper luer female fitting 62 is provided.
Syringe 20 includes a conventional syringe body 66 having a flange 68 at the end thereof. Syringe body 66 is provided with a luer fitting 70 designed to engage luer fitting 62 in outer housing 14 . Mounted interiorly of syringe body 66 is a plunger 72 which has a passageway 74 extending therethrough. A hydrophobic membrane 76 covers passageway 74 .
Syringe plunger rod 22 includes a shaft 80 having a head 82 at one end thereof and a base 84 . In operation, activation cap 16 is used to push by-pass cartridge 12 forwardly such that septum 30 is pierced thereby and a fluid passageway between syringe 20 and front compartment 42 is established.
Subsequently, plunger rod 18 is attached to rear plunger 34 and pressure exerted thereon. The liquid in rear compartment 40 is substantially incompressible and accordingly, pressure is exerted on intermediate plunger 38 to move it forwardly to the area of by-pass 28 . At this point, the diluent can enter into front compartment 42 to mix with the pharmaceutical component therein. A continued advancement by pressure on plunger rod 18 will cause both plungers 34 , 38 to advance and air contained within front compartment 42 will pass through bore 60 of piercing member 58 . The air will enter syringe body 66 and be expelled through passageway 74 . In the meantime, hydrophobic membrane 76 will prevent passage of any liquid therethrough.
The continued advancement of plungers 34 , 38 will force the mixture into syringe body 66 with plunger 72 being forced rearwardly. Once all the mixture has been moved to syringe body 66 , plunger rod 22 may then be activated to cause the mixture to move into front compartment 42 . This back and forth movement may be continued as long as needed to ensure the proper mixing of the components. The passing through bore 60 which is relatively small will ensure the mixing of the two components while preventing any foaming or air bubbles.
Preferably, plunger rod 22 is not secured to plunger 72 . This will prevent any aspiration movement which would permit air to enter the mixture.
As shown in FIGS. 3A , 3 B and 3 C, plunger 72 may take several different forms. Thus, plunger 72 may have an insert 90 about which resilient material 92 extends. Hydrophobic membrane 94 extends across the top thereof.
In the embodiment of FIG. 2B , hydrophobic membrane 94 merely extends across resilient material 92 . In the embodiment of FIG. 2C , hydrophobic membrane 94 is sandwiched between two portions of resilient material 92 .
Turning to the embodiment of FIG. 4 , there is illustrated a mixing and transferring device similar to that illustrated in FIG. 1 and similar reference numerals in the 100's are employed for similar components.
In this embodiment, plunger rod 118 has a shaft 148 with threads 115 formed on a portion thereof. Threads 115 engage with flange 127 formed on activation cap 116 .
This arrangement permits a relatively slow movement of the plungers as the initial movement is dependent on the turning of plunger rod 118 . After threads 115 have finished, a final pushing motion may be employed as in the previously described embodiment.
In the embodiment of FIG. 5 , reference numerals in the 200's are utilized for similar components.
Transfer and mixing device 210 includes a plunger rod 248 which has a plurality of teeth 229 formed on one side thereof.
A housing 231 is secured to activation cap 216 . Housing 231 includes a rotatable pinion 233 by means of a thumb wheel 235 . Thus, movement of thumb wheel 235 will drive plunger rod 218 in a manner previously described.
A cap 237 is mounted about plunger rod 218 and may be removed for a final pushing action thereon.
Also, as will be noted in this drawing, syringe 220 has a coil spring 239 mounted therein. A cap 241 is used for covering the end of syringe body 266 .
With the arrangement of FIG. 5 , transfer of the mixture into syringe 220 will continue as long as pressure is exerted on plunger rod 218 . Once pressure has been removed, spring 239 will bias plunger 272 and the mixture will automatically be returned to front compartment 242 .
In FIG. 6 , reference numerals in the 300's are employed with similar reference numerals designating similar components. The plunger rod 318 , in this embodiment, includes a plurality of teeth 343 on the end of shaft 348 proximate head 346 . In this arrangement, cap 337 must be removed and plunger rod 318 rotated such that teeth 343 will then engage pinion 333 .
In FIG. 7 , there is illustrated a front cap which could be employed with the outer housing of the previous embodiments. Cap 351 includes a hydrophobic membrane 353 extending over an internal passageway with a male luer connection 355 .
It will be understood that the above described embodiments are for purposes of illustration only and that changes and modifications may be made thereto without departing from the spirit and scope of the invention. | A method for transferring and mixing a pharmaceutical mixture utilizing a by-pass cartridge and a syringe. After mixing the dry component and the diluent in the by-pass cartridge, the mixture can be passed to a syringe which includes a syringe plunger having a fluid passageway therein with a hydrophobic membrane covering the passageway. The mixture can be transferred back and forth between the by-pass cartridge and the syringe through a small bore to achieve mixing, particularly in the case of microspheres held in suspension. | 0 |
[0001] This application claims priority under 35 U.S.C. §119(e) of provisional application Ser. No. 60/961,752, filed on Jul. 24, 2007.
BACKGROUND OF THE INVENTION
[0002] 1. Field of the Invention
[0003] The present invention relates to a manufacturing method to control the size velocity and relative position of a reclosable mechanism or multiple reclosable mechanisms, such as a zipper or zippers on a flexible plastic film, bag or pouch.
[0004] 2. Description of the Prior Art
[0005] In the prior art of the manufacture of zippers and similar devices for reclosable plastic film, bags or pouches, the velocity of the delivery of the resin to the profiles or to the locking elements could not be accurately controlled by such elements as a choke device. This inability to accurately control the resin velocity made it difficult to extrude complex locking mechanisms at a reasonable cost and production rate.
[0006] Further prior art includes methods where the zipper tape is extruded, wound and then, in a secondary process, unwound, heated and attached to the film. Still further prior art may be found in published patent application US2005/0269733 A1 entitled “Method of and Apparatus for Forming Multiple Closure Elements”.
OBJECTS AND SUMMARY OF THE INVENTION
[0007] It is therefore an object of the present invention to provide a method and apparatus for the manufacture of complex locking mechanisms for reclosable interlocking elements, such as a zipper profile on a flexible film plastic package, bag or pouch, at a reasonable cost and production rate.
[0008] It is therefore a further object of the present invention to provide accurate control of the velocity of the resin flow delivered to the profile at its point of juncture with the film or tubing of the reclosable plastic package, bag or pouch.
[0009] It is therefore a still further object of the present invention to improve adhesion of closure elements to the body of the package, bag or pouch by preventing exposure of the contact surfaces.
[0010] These and other objects are attained by cooling the integral profile tubing and drawing it in a negative ratio whereby the circumference of the cooled and drawn finished tubing is less than the circumference of the die plate. The resin for the profile interlocking elements is delivered from a co-extruder through a separate channel, or several separate channels, to the die body and thence to the die plate, where the resin is joined to the film (tubing) at a controlled rate, with the control being the speed of the co-extruder drive.
DESCRIPTION OF THE DRAWINGS
[0011] Further objects and advantages of the invention will become apparent from the following description and claims, and from the accompanying drawings, wherein:
[0012] FIG. 1 is a schematic of the apparatus of the present invention.
[0013] FIGS. 2 a - 2 i are examples of zipper profiles which can be produced by the apparatus of the present invention.
DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENT
[0014] Referring now to the drawings in detail, wherein like numerals indicate like elements throughout the several views, one sees that FIG. 1 is a schematic of the apparatus 10 of the present invention. Extrusion die body 12 receives the material for the formation of the tubing (e.g. a tube or a film), such as, but not limited to, low density polyethylene, from primary extruder 14 and extruder material hopper 16 via supply channel 18 . Supply channel 18 joins extrusion die body primary supply channel 20 which is formed within extrusion die body 12 . Extrusion die body primary supply channel 20 , in turns, feeds the material for the tubing to the extrusion die cavity 22 where the tube or film 100 is formed. Tube or film 100 , typically in a cylindrical shape, exits from the mouth 24 of extrusion die plate 13 , and therefore may be referred to as tubing (or as a low density polyethylene bubble). The tubing is typically drawn into a negative ratio and cooled. That is, due to the speed of the film and related factors, the circumference of the cooled and drawn finished tubing 100 is typically less than the circumference of the extrusion die plate 13 , but in some applications may be the same size or even greater than the circumference of the extrusion die plate 13 .
[0015] Secondary extruders 30 , 34 include respective secondary extruder material hoppers 32 , 36 supplying material, such as resin (which may be colored or uncolored), for the formation of the reclosable profiles. The use of colored resin allows the user to see and handle the profiles more easily. The resin, or similar material, may be the same in secondary extruders 30 , 34 or may be different (including such characteristics as color). It is envisioned, however, that the primary extruder 14 would supply a flexible, soft and pliable material while the secondary extruders 30 , 34 would supply a more rigid, robust material for forming reclosable profiles 102 , 104 . The resin, or similar material, is provided via respective secondary supply channels 38 , 40 (typically implemented as heated hoses) and respective secondary die body supply channels 42 , 44 to the die plate, where it is joined to the tubing 100 at a controlled rate (as well as a controlled temperature), with the control being the speed of the drive of the secondary extruders 30 , 34 , thereby forming reclosable profiles 102 , 104 on tubing 100 . The resin (or other material) from the secondary extruders 30 , 34 for forming the reclosable profiles 102 , 104 does not come into contact with the material (tube or film 100 ) from the primary extruder 14 until it reaches the extrusion die plate 13 typically approximately one half inch (although other distances are envisioned) before both exit the extrusion die body 12 . The control of the speed of the drive of the secondary extruders 30 , 34 and or control of the temperature of the resin or similar material provided to the secondary supply channels 38 , 40 (is, in turn, typically controlled by CPU 200 or a similar processing device) thereby provides the ability to extrude more complex shapes of the interlocking elements than was previously possible. Additionally, it is envisioned that as many as nine, or even more, secondary extruders may be used, with respective material supplies and secondary supply channels to form the various complex shapes. FIGS. 2 a - 2 i are representative of a sample of the many profile shapes that are possible with various embodiments of the present invention which, applicant believes, have been difficult, if not impossible, to obtain with the prior art, particularly with respect to multiple interlocking elements formed on a single profile.
[0016] The resulting configuration typically has many or all of the following advantages:
[0017] 1. the velocity and speed of the resin for the locking mechanism is controlled separately from that of the tubing;
[0018] 2. the velocity of the resin for the interlocking elements is controlled accurately and separately from that of the tubing;
[0019] 3. the distance between sets of profiles is controlled;
[0020] 4. more complex locking mechanisms may be manufactured;
[0021] 5. the cooling rate of the interlocking elements is accurately controlled;
[0022] 6. more complex multiple interlocking elements are possible;
[0023] 7. interlocking elements with separators between the interlocking elements can be provided;
[0024] 8. the shapes, construction and structural characteristics of the interlocking elements are controlled, including profiles with multiple interlocking elements;
[0025] 9. the tubing may have two or more sets of profiles, each set provided with separate sources of profile control;
[0026] 10. the separate resin source can be a co-extruder (or secondary extruder);
[0027] 11. the profiles are provided with multiple interlocking elements;
[0028] 12. a co-extruder (or secondary extruder) can provide resin flows to several sets of profiles or a separate co-extruder (or secondary extruder) can be used for each resin flow;
[0029] 13. the flow of resin to the profiles can be controlled, so that the profiles cool at a controlled rate; and
[0030] 14. the speed of the profile extrusion can be controlled so that the speed of the profile extrusion and the speed of the film extrusion are equal when the profile and the film come into contact with each other.
[0031] Thus the several aforementioned objects and advantages are most effectively attained. Although preferred embodiments of the invention have been disclosed and described in detail herein, it should be understood that this invention is in no sense limited thereby and its scope is to be determined by that of the appended claims. | The apparatus includes an extrusion die and further includes a main or primary extruder for the supply of material, such as low density polyethylene, to form the tubing for the manufacture of reclosable packages, bags or pouches. The apparatus further includes at least one secondary extruder, or co-extruder, for the extruding of each reclosable profile onto the tubing. The speed of the co-extruders is controlled so as to control the extrusion of the reclosable profiles. | 1 |
BACKGROUND OF THE INVENTION
The present invention relates to a system for automatically defining the minimum (i.e. closed) setting of a valve controlled by an accelerator for regulating air supply to an internal combustion engine, in particular, a throttle valve located at the inlet of an induction manifold on an electronic injection system.
Electronic injection systems on internal combustion engines are known to present an electronic control system which, depending on signals received from various sensors (mainly engine speed/stroke and air intake pressure/temperature sensors) determines, for example, the air density in the manifold and engine speed, and calculates, via interpolation on respective memorized maps, the stroke and timing for injecting fuel into the injectors, as well as the spark lead. Provision may be made for one of the said injectors on each cylinder, i.e. located downstream from the throttle valve, or for a single injector located upor downstream from the said throttle valve. For determining specific operation of the electronic control system, particularly during transient states, the said control system is supplied with signals from additional sensors, such as a throttle angle sensor, which also indicates the minimum (substantially closed) setting of the valve. The throttle angle transducer usually empolyed is a potentiometer connected mechanically to the valve spindle, the electric output signals from the potentiometer being supplied to an analogue-digital converter which supplies the throttle setting signal to the control system. Such known solutions, however, involve a number of drawbacks in terms of precise indication of the said minimum setting, particularly long-term precision, which may be affected by incorrect positioning of the potentiometer on the valve spindle, or by other sources of error due to thermal drift, mechanical wear, etc.
SUMMARY OF THE INVENTION
The aim of the present invention is to provide a system for automatically defining the minimum setting of an accelerator-controlled valve for supplying an internal combustion engine, designed to overcome the aforementioned drawbacks, i.e. a system enabling said minimum setting to be regulated automatically, eliminating the effect of potential initial setting errors, or subsequent thermal drift or mechanical wear.
Further aims and advantages of the present invention will be disclosed in the following description.
With this aim in view, according to the present invention, there is provided a system for automatically defining the minimum setting of a valve controlled by an accelerator for supplying an internal combustion engine, characterised by the fact that it comprises means for repeatedly detecting the setting of said valve in relation to a given minimum setting value, said means defining a new said given minimum setting, should said setting of said valve remain steadily, in excess of given time limits, within setting limits respectively over and below said given minimum setting value.
BRIEF DESCRIPTION OF THE DRAWINGS
One embodiment of the present invention will be described by way of a non-limiting example, with reference to the accompanying drawings, in which:
FIG. 1 shows a schematic view of an electronic injection system for an internal combustion engine with the system for automatically defining the minimum setting of a throttle valve according to the present invention;
FIG. 2 shows an operating block diagram of the system for automatically defining the minimum setting of a throttle valve according to the present invention; and
FIG. 3 shows, schematically, the behaviour of a number of signals on the system according to the present invention.
DETAILED DESCRIPTION OF THE INVENTION
FIG. 1 shows, schematically, an electronic injection system for an internal combustion engine 101, conveniently a four-cylinder engine, shown partially and in cross section.
The said system comprises an electronic control system 102 comprising, in substantially known manner, a microprocessor 121, and registers in which are memorized maps relative to various operating conditions of engine 101. The control system 102 also comprises memory registers 109 and an up-down counter 122 ranging from 0 to 255, and receives signals from :
a sensor 103, for detecting the speed of engine 101, located opposite a pulley 104 fitted onto drive shaft 125 and having four teeth 131 equally spaced at 90° intervals;
a sensor 105, for detecting the stroke of engine 101 and located in a distributor 126;
a sensor 106, for detecting the absolute pressure inside an induction manifold 107 on engine 101;
a sensor 108, for detecting the air temperature inside manifold 107;
a sensor 110, for detecting the water temperature inside the cooling jacket on engine 101;
a sensor 111 consisting of a potentiometer mechanically connected to a spindle 129 related to the angle of a throttle valve 112 located inside induction manifold 107 and controlled by the pedal of accelerator 113. Parallel to the said throttle valve 112, there is provided an additional air supply valve 114.
The electronic control system 102 is connected to an electricity supply battery 115 and grounded, and, depending on the signals from said sensors, engine speed and air density are employed for determining fuel supply according to the required mixture strength. The control system 102 therefore controls the opening time of electroinjectors 116 located inside manifold 107 next to the intake valve of each respective cylinder, for controlling fuel supply to the cylinders on engine 101, and also controls injection timing for commencing fuel supply according to the stroke (induction, compression, expansion, exhaust) of engine 101. Each electroinjector 116 is supplied with fuel via a pressure regulator 117 sensitive to the pressure inside induction manifold 107 and having a fuel inlet duct 118 from a pump (not shown) and a return duct 119 to a tank (not shown). Electronic control system 102 is also connected to a unit 120 for controlling the ignition pulses supplied to distributor 126.
The system for automatically defining the minimum setting of throttle valve 112 according to the present invention will now be described with reference to FIG. 2, with a brief preview of FIG. 3 in which POSFARF indicates the digital signal supplied by potentiometer 111 and indicating the angle of throttle valve 112. In the system according to the present invention, the said POSFARF value may only represent a preselected minimum setting value within the O and SSF value range, as described later on. FARMIN indicates the digital value assumed as a preselected minimum setting value of throttle valve 112. ISTMIN indicates an angle range in excess of the FARMIN value and within which may be located a newly-defined minimum setting of throttle valve 112, higher than the preselected minimum setting value, as described in more detail later on. The system for automatically defining the minimum setting of throttle valve 112, according to the present invention, briefly operates as follows. If, via microprocessor 121, the setting of the said throttle valve 112 (as indicated by the POSFARF signal) is found to be steady, either below the FARMIN value, as far as zero, or over the FARMIN value, within the ISTMIN range, for longer than given preset time limits, the said steady setting is taken as corresponding to a new minimum setting, which is thus redefined by progressively shifting the previously memorized setting, within the said limit values O and SSF.
FIG. 2 shows the routine performed repeatedly by microprocessor 121 at each general performance of the processing routine for the electronic injection system, and which, with engine 101 idling, is repeated approximately every 30 milliseconds. Block 11 determines whether the program performance in question is the first for starting up the engine. In the event of a positive response, block 11 goes on the block 12, which enters, as an initial preselected minimum setting value for throttle valve 112, the maximum value permitted: FARMIN=SSF, after which, block 12 goes on to block 13. In the event of a negative response in block 11, i.e. in subsequent repeat performances of the program, block 11 goes directly on to block 13, which determines whether the setting of throttle valve 112 (POSFARF) is less than or equal to the preselected minimum setting value (FARMIN). In the event of a negative response, assuming, for example, a valve setting as shown by letter A in FIG. 3, block 13 goes on to block 14, which determines whether the said valve setting is less than or equal to the said preselected minimum setting value (FARMIN) plus the ISTMIN range. Assuming the valve setting is as shown by A in FIG. 3, the response from block 14 will be negative, in which case, block 14 goes directly on to an output block 15, which controls subsequent program stages by microprocessor 121 for calculating injection and ignition timing with no change in the said preselected minimum setting value (FARMIN) in that the detected setting value (A) is greater than the preselected minimum setting value.
If, on the other hand, the setting of throttle valve 112 is as shown by letter B in FIG. 3, i.e. within the ISTMIN range, block 14 issues a postive response and goes on to block 16, which determines whether the content of counter 122 is below hexadecimal 8OH, i.e. below 128, which is the count initiation value of counter 122, as described in more detail later on. A positive response indicates the existence of previous stages in which the setting of throttle valve 112 was below the preselected minimum setting value (FARMIN), in which case, block 16 goes on to block 17, which resets counter 122 to the initial 8OH value and then goes on to block 15. In the event of a negative response, however, in block 16 (steady setting within the ISTMIN range), block 16 goes on to block 18, which steps up the content of counter 122 by a quantity VICNMIN. Block 18 then goes on to block 19, which determines whether the content of counter 122 exceeds the maximum value FFH, i.e. 255. In the event of a negative response, block 19 goes on to block 15, for repeating the processing cycle in a subsequent program cycle. In the event of a positive response (maximum count on counter 122, thus indicating that setting B has been maintained over a given preset time limit), block 19 goes on to block 17' which, like block 17, resets counter 122 to 8OH and then goes on to block 21, which determines whether the memorized preselected minimum setting value (FARMIN) is equal to the maximum permitted value (SSF). In the event of a positive response, the said value is left unchanged and block 21 goes on to output block 15. In the event of a negative response, block 21 goes on to block 22 which defines a new preselected minimum setting value, by adding one count unit to the previous value: FARMIN=FARMIN +1, and then goes on to output block 15.
If, on the other hand, the setting of throttle valve 112 is as shown by the letter C in FIG. 3, block 13 goes on to block 24, which determines whether the content of counter 122 is over 8OH, thus indicating that, in previous processing stages, the setting of throttle valve 112 was maintained steadily within the ISTMIN range. In the event of a postive response, block 24 goes on to block 17" which, like block 17, resets counter 122 to the initial 8OH value and then goes on to block 15. In the event of a negative response in block 24 (indicating that, in previous processing stages, the setting of throttle valve 112 was maintained steadily below the FARMIN value), block 24 goes on to block 25, which subtracts, from the content of counter 122, a quantity VDECMIN conveniently greater than the VINCMIN quantity added in block 18. Block 25 then goes on to block 26, which determines whether the content of counter 122 is below zero, i.e. whether the setting of throttle valve 112 has been below the preselected minimum setting value (FARMIN) for longer than a given preset time limit depending on the VDECMIN value. In the event of a negative response, block 26 goes on to output block 15, for performing a further processing stage via control system 102. In the event of a postive response, block 26 goes on to block 17"' which, like block 17, resets counter 122 to the initial 8OH value and then goes on to block 27, which determines whether the preselected minimum setting value (FARMIN) equals zero. In the event of a positive response, the said preselected minimum setting value is left unchanged and block 27 goes on to block 15. In the event of a negative response (as in the case of setting C in FIG. 3), block 27 goes on to block 28, which defines a new preselected minimum setting value by subtracting one count unit from the previous value: FARMIN=FARMIN-1, and then goes on to output block 15.
The advantages of the system for automatically defining the minimum setting of an accelerator-controlled valve for supplying an internal combustion engine, according to the present invention, will be clear from the foregoing description. In particular, it enables changes to be made over time to the reference value for the signal suppled by potentiometer 111 and defining the minimum setting of throttle valve 112, thus enabling greater positioning tolerance of potentiometer 111 on spindle 129 of throttle valve 112, by virtue of the said minimum setting no longer being determined by a fixed output value on potentiometer 111. Furthermore, it provides for recovering system drift caused by changes in temperature, mechanical wear, etc., and, finally, for employing additional cold air devices acting directly on the setting of throttle valve 112.
To those skilled in the art it will be clear that changes may be made to the embodiment of the sytem described and illustrated herein without, however, departing from the scope of the present invention. | A system for automatically defining the minimum setting of a valve controlled by an accelerator for supplying air to an internal combustion engine, which system comprises means for repeatedly detecting the setting of the valve in relation to a given minimum setting value; which means define a new given minimum setting value, should the setting of the valve remain steadily, in excess of given time limits, within setting limits respectively over and below the aforementioned given minimum setting value. | 5 |
CROSS REFERENCE TO RELATED APPLICATIONS
[0001] This application asserts priority from provisional application 61/369,258, filed on Jul. 30, 2010 which is incorporated herein by reference.
FIELD OF THE INVENTION
[0002] This invention provides a drying rack for athletic equipment which allows air circulation around the equipment.
BACKGROUND OF THE INVENTION
[0003] During play, sporting equipment can become very damp especially heavy equipment such as that used in hockey or football. Frequently such equipment is stored on the floor, in a closet, or even in a bag, where it dries very poorly. The long period of dampness allows for bacterial growth and the development of a rather unpleasant odor. U.S. Pat. No. 6,073,783 relates to a light weight foldable drying rack having a number of adjustable members which may be moved to various positions. The drying rack may be folded into a small package for convenient storage. The preferred construction material is a moisture resistant plastic. A potential problem with a light weight drying rack is that care must be used in placing heavy sports equipment on the rack to avoid having the unit tip. A potential problem with a plastic rack is that plastic is hydrophobic and does not wick water away from damp clothing. Drying racks made of steel are available, however, steel has a tendency to rust, and the rust can stain the items being dried.
SUMMARY OF THE INVENTION
[0004] The present invention provides a natural wood, odor neutralizing, drying rack for sporting equipment. The wood which makes up the portion of the rack in contact with the sporting equipment or other items to be dried is not finished with oil finishes, paints, varnishes and the like, but rather is smoothed, and left in its natural condition. The rack has a base, a vertical member, a plurality of horizontal members attached to the vertical member, a plurality of pegs attached to the vertical member, a plurality of pegs are attached to the horizontal members, and a plurality of upward angled members attached to the vertical member. The base may be made from a wide variety of materials and may be finished. The wood has the advantage that it is sturdier than plastic, and that won't rust like steel.
BRIEF DESCRIPTION OF THE DRAWINGS
[0005] FIG. 1 shows a perspective view of the drying rack.
[0006] FIG. 2 shows a side view of the drying rack.
DETAILED DESCRIPTION OF THE INVENTION
[0007] FIG. 1 shows a perspective view of the drying rack. At the bottom of the rack is a base 1 which supports the rack. A vertical member 2 is attached to the base 1 and extends upward. Horizontal members 3 are attached to the vertical member 2 . Pegs 4 are attached both to the horizontal members and to the vertical member. Upward angled members 5 are attached to the vertical member.
[0008] FIG. 2 shows a side view of the drying rack. At the bottom of the rack is a base 1 which supports the rack. A vertical member 2 is attached to the base 1 and extends upward. Pegs 4 are attached to the vertical member. Upward angled members 5 are attached to the vertical member.
[0009] The function of the base 1 is simply to provide a place to attach the vertical member 2 , and to support the drying rack when sports equipment or other items to be dried are placed upon it. Accordingly, it must be sufficiently wide and sufficiently heavy to resist tipping of the rack. The base 1 may constructed from a variety of materials. For example, it could be made from the same wood material used to construct the remainder of the rack. The base 1 , could be made from a different wood than that used to construct the rest of the rack or from wood products such as plywood, chipboard and fiberboard. If the base 1 is made from wood or a wood product it may optionally be finished with a finish such a lacquer, varnish, or paint. Optionally, the base 1 could be made from metal. A metal base 1 may be lacquered, painted, or plated with a damage resistant metal such as chromium or nickel. For aesthetic reasons it is preferred that the base 1 be made from the same natural wood as the rest of the rack.
[0010] The portion of the rack which supports the items to be dried is made from natural unfinished wood. The wood is shaped and smoothed, but is not finished with any oil finishes, paints, varnishes and the like. A wide variety of woods can be used such as pine, fir, cedar, bamboo, walnut, oak, mahogany, cherry, pecan, maple, birch, and ash. Less common woods such as beech, Brazilian cherry, ebony, hickory, teak, rubber wood, and rosewood may also be used. The choice of wood is dictated by availability, and the appearance which is desired. Cost is also a consideration since rare expensive woods do not add to the functionality of the drying rack. The use of natural unfinished wood is important because wood has the ability to wick water away from wet clothing items. In addition, wood does not support bacterial growth. A wooden rack helps the items to be dried to dry more quickly, while developing less of the odors which could be caused by bacteria. While all woods have odor neutralizing properties, cedar wood has especially good odor neutralizing properties, and has a pleasant aroma. It is a preferred wood for construction of the rack. Where cost is a consideration, pine or fir function well, and can provide a pleasing utilitarian appearance. Finishing the wood with a varnish or other such finish destroys the desirable water wicking and antibacterial properties of the wood. Accordingly, the base 1 of the rack, which does not come in contact with the items being dried, may be finished in some manner, while the remainder of the rack should be unfinished natural wood. If desired, different portions of the rack may be constructed from different woods. For example, the various members of the rack could be constructed from oak, while the pegs 4 might be maple. Alternatively the base 1 and vertical member 2 could be pine, while the horizontal members 3 could be cedar.
[0011] The vertical member 2 supports the rest of the members and pegs used for drying. It should be of sufficient strength to support the weight of the items to be dried on the rack. It is preferred that the vertical member have a square or rectangular cross section. A preferred size is 2×4 inches (prefinished size). It is possible to use a vertical member 2 having a circular cross section. However, the use of a vertical member 2 having a circular cross section increases construction difficulties. The vertical member 2 may be any convenient length. A length of between 5 and 6 feet is generally convenient.
[0012] The horizontal members 3 are made of somewhat smaller wood pieces than the vertical member 2 . This is because each horizontal member 3 has less weight to support than the vertical member 2 . Examples of the sort of equipment which may be hung on the horizontal members are skates, protective gloves, shoes, cleats, and protective pads. It is preferred that the horizontal member have a square or rectangular cross section. A preferred size is 1×2 inches (prefinished size). It is possible to use a horizontal member 3 having a circular cross section. However, the use of a horizontal member 3 having a circular cross section increases construction difficulties. The horizontal member 3 may be of any convenient length. A length of approximately two to three feet is preferred. There may be a plurality of horizontal members 3 . The number is preferred to be in the range of one to four horizontal members 3 . Two to three horizontal members 3 has been found to be convenient. The horizontal members 3 may be of different lengths, or cross sections. For example, a lower horizontal member 3 might be constructed from thicker wood than an upper horizontal member 3 on the basis that the lower horizontal member 3 will be used to support heavier items.
[0013] The pegs 4 may be attached to the vertical member 2 and to the horizontal members 3 . It is preferred that the pegs be attached to the horizontal members in a symmetrical manner. Thus, if a horizontal member 3 has a peg 4 at one end, it is preferred that a similar peg 4 be placed at the other end of the horizontal member. The main reason for this placement is to preserve balance. The pegs 4 may be close to the end of a horizontal member, or they may be placed closer to the center. Wherever they are placed, on the cross member, symmetrical placement is preferred. Pegs 4 may also be attached to the vertical member 2 . The pegs 4 attached to the horizontal members 3 or vertical member 2 may be either horizontal or extend at an upward angle. If the pegs have an upward angle, it can vary over a wide range. A range from 20° above horizontal to 20° away from vertical has been found to be useable. An angle of 45° is preferred. Pegs attached near the top of the vertical member may be used to hang longer items. The advantage of this is that these items can have more contact with the wood of the vertical member. If desired, the pegs on the horizontal members may be used to hold long items such as hockey sticks. Although hockey sticks don't require drying, it is convenient to have them associated with the other equipment. It is preferred that pegs 4 preferably have a circular cross section although pegs 4 having a rectangular cross section could be used. The pegs should be of sufficient diameter to support a heavy item such as an athletic shoe. Peg diameters of ¼ to ½ inches have been found to be appropriate. The may be a plurality of pegs 4 . The number is preferred to be in the range of two to eight pegs 4 . Three to eight pegs 4 have been found to be convenient. For many applications three to four pegs 4 are preferred.
[0014] The upward angled members 5 can be constructed from the same material as the horizontal members 3 . A square or rectangular cross section is preferred. A preferred size is 1×2 inches (prefinished size). It is possible to use a upward angled member 5 having a circular cross section. However, the use of an upward angled member 5 having a circular cross section increases construction difficulties. The upward angled member 5 may be of any convenient length. A length of approximately 1 to 1.5 feet is preferred. The may be a plurality of upward angled members 5 . The number is preferred to be in the range of two to 8 upward angled members 5 . Four to eight upward angled members 5 have been found to be convenient. The upward angled members 5 may be of different lengths, or have different cross sections. For example, a lower upward angled member 5 might be constructed from thicker wood than an upper upward angled member 5 on the basis that the lower upward angled member 5 will be used to support heavier items. The upward angle can vary over a wide range. A range from 20° above horizontal to 20° away from vertical has been found to be useable. An angle of 45° is preferred. Examples of the sort of equipment which may be hung on the upward angled members are skates, protective gloves, shoes, and cleats.
[0015] Optionally the vertical member 2 may have holes allowing better air circulation. The holes cannot be so numerous or so large that they weaken vertical member 2 . In a vertical member constructed of 2×4 inches (prefinished size) wood, one ¼ inch hole per foot would provide air circulation without seriously damaging the vertical member 2 . Alternatively, a larger number of smaller holes could be used. One additional use for an optional hole in the vertical member 2 would be to hold a small container of a deodorant material, such as a citrus gel air freshener.
EXAMPLE I
[0016] A dying rack was constructed from pine and cedar woods. The base was made from 2×4 lumber and was approximately 20 inches wide. The vertical member was made from 2×4 lumber and was 26.5 inches tall. There were no holes in the vertical member. The two horizontal members were made from 1×2 lumber and were 26.5 inches wide. There were three ¼ inch pegs. One was placed near the top of the vertical member, and two were placed on the lower horizontal member. The six upward angled members were made from 1×2 lumber and were 15.5 inches wide. The drying rack weighed 9 pounds. Damp hockey equipment including face guards, pads, a shirt, skates, and gloves were placed on the rack and dried in three hours. | The present invention provides a natural wood, odor neutralizing, drying rack for sporting equipment, and other items to be dried. The wood which makes up the portion of the rack in contact with sporting equipment or other objects to be dried is not finished in any way, but is rather is left in its natural condition. | 3 |
BACKGROUND OF THE INVENTION
1. Field of the Invention
The present invention relates to a drilling control apparatus capable of automatically controlling a rock drill mounted on a drilling apparatus such as a crawler drill or the like.
2. Description of the Related Art
In a drilling apparatus such as a crawler drill or the like which is used in a drilling work at a spot of a mine, a quarry, a construction working or the like, the drilling is performed by transmitting an impacting force and a rotational force to a bit attached to a rod end from a rock drill mounted on a guide shell, and by advancing the rock drill.
In a general procedure of drilling, first, a start collaring operation is performed to position the bit end, and subsequently, a collaring operation is performed to position the drilling and to prevent the curving of the hole, and then a regular drilling operation is performed. In the case of performing a long hole drilling, when the drilling of a length of one rod is finished, another rod is added to the rod, and the addition of the rod is repeated until a predetermined hole length is reached.
In such a drilling work, the operator grasps the operating condition of each operating mechanism of the rock drill by visual and aural observation and judges, during the collaring the property of the rock which is the object of the drilling, and starts the regular drilling by adjusting an operating condition of each operating mechanism according to the property of the rock. Since the property of the rock which is the object of the drilling is not constant but varies, the operator, also thereafter always grasps the operating condition of each operating mechanism and judges a variation of the property of the rock, and each time the drilling condition varies, manipulates and adjusts manipulation equipment such as hydraulic valves and electrical switches so as to enable to quickly drill with a minimum load incurred on the rock drill, the rod, and the bit.
However, since such a drilling work requires to always monitor the operating condition of the rock drill and to adjust the operation, the fatigue of the operator increases. Furthermore, the work to grasp the operating condition of each operating mechanism of the dock drill by visual and aural observation during drilling and to judge the property of the rock involves a large individual difference depending on the skill level of the operator, and the non-uniformity is apt to be caused in the drilling efficiency, the linearity of drilling, the finish of hole wall, etc., in particular in the drilling precision. When the drilling precision is decreased, a difference between the planed drilling pattern and the actual drilling pattern is increased, and the crushing cannot be performed uniformly.
SUMMARY OF THE INVENTION
The present invention solves the problems in the prior art drilling control of the rock drill, and it is an object of the invention to provide a drilling control apparatus of a rock drill which enables to reduce the fatigue of the operator by automating the drilling control, and to achieve the stable drilling precision and drilling efficiency without being affected by the skill level of the operator.
The drilling control apparatus of a rock drill according to the present invention comprises detection means for detecting an operating condition of an impacting mechanism, a rotating mechanism, a feed mechanism, and a flushing mechanism of the rock drill mounted movably forward and backward on a guide shell, and a control unit for controlling a drilling operation of the rock drill by judging a drilling condition on the basis of detection data from the detecting means.
At the time of drilling work, when the operator commands a start of drilling by designating a drilling length, the rock driller starts advancement on the basis of program data of a drilling procedure stored in the control unit. When an end of the bit reaches the rock which is the object of crushing, this arrival position on the rock is detected by the detecting means, and inputted as a zero point of the drilling length into the control unit, and thereafter the drilling length is obtained by using this zero point as a reference.
After detecting the arrival at the rock, a start collaring operation to perform positioning of the end of the bit is started, and when a predetermined length of start collaring has been performed, the finish of the start collaring is detected, and a collaring is started. When a predetermined length of collaring has been performed, the finish of the collaring is detected. Then, a real drilling is started.
In the case of performing the drilling of a long hole, when the drilling of one-rod length is finished, another rod is added to the rod now in use, and the drilling and the addition of rod are repeated until a designated drilling length is reached.
During the drilling, the situation including whether the rock is hard or soft, a crack is present or not, etc., is judged by the control unit on the basis of the detection data, and if there is any change, the setting of the drilling conditions is changed.
The conditions for the drilling operation at the time of start of the real drilling are set by the control unit by judging the property of the rock on the basis of the detection data obtained in the collaring, and thus it is possible to instantly perform an appropriate regular drilling.
The control unit judges the presence or absence of an abnormality in the drilling operation such as an increase in rotational resistance and a blocking of a bit hole, etc., on the basis of the detection data including a rise in rotational pressure and a rise in a flushing pressure or the like during drilling, and in the case of abnormality, the operation for abnormality avoidance such as retraction of the rock drill or the like is performed thereby to prevent expansion of the drilling failure and to return the rock drill to a normal drilling condition at an early stage.
The control unit is arranged, during temporary stopping of the drilling operation, to store a drilling condition before the stopping, and at the time of restart of the drilling operation, to set the conditions for the drilling operation in a similar manner as before the stopping. Accordingly, even when the drilling operation is stopped temporary due to the adding work of the rod, or the like, it is possible to restart the drilling operation in an appropriate condition.
BRIEF DESCRIPTION OF THE DRAWINGS
FIG. 1 is a perspective view of a hydraulic crawler drill having a drilling control apparatus of a rock drill which is one embodiment of the present invention.
FIG. 2 is a longitudinal sectional view of the rock drill.
FIG. 3 is a block diagram showing an arrangement of the drilling control apparatus of the rock drill.
FIG. 4 is a front view of an input section of the drilling control apparatus.
FIG. 5 is a flowchart showing an example of a start collaring process.
FIG. 6 is a flowchart showing an example of a collaring process.
FIG. 7 is a flowchart showing an example of a regular drilling process.
DESCRIPTION OF THE PREFERRED EMBODIMENTS
With reference to FIGS. 1 to 4, a hydraulic crawler drill 1 includes a boom 8 mounted on a running truck 5 provided with a truck frame 2, and the boom 8 is allowed to turn and to move upward and downward. A guide shell 11 mounting thereon a rock drill 10 is supported on an end portion of the boom 8 tiltably and swingably. A shank rod 3 is mounted on the rock drill 10, and a rod 4 of a predetermined length is connected to the shank rod 3 through a sleeve 7, and a bit 6 is attached to an end of the rod 4.
The rock drill 10 includes an impacting mechanism 13, a rotating mechanism 9 and a flushing mechanism 14, and the rock drill 10 is movable forward and backward by a feed mechanism 12 provided in the guide shell 11. The drilling of rock is performed by transmitting a striking force and a rotating force to the bit 6 through the shank rod 3 and rod 4 from the striking mechanism 13 and the rotating mechanism 9. Furthermore, the flushing mechanism 14 supplies compressed air to the end of the rod 4 to discharge dust produced by the drilling. A dust pot 36 is attached to the front end of the guide shell 11 to cover a drilling hole end, and the dust pot 36 is connected to a dust collector (not shown) to collect the discharged dust.
When the length of a hole to be drilled is longer than the length of the rod 4, since it is necessary to add a rod to the rod 4 and to recover the rod, the guide shell 11 is provided with a rod exchange device 17 for adding and recovering the rod.
On the running truck 5, as shown in FIG. 1, there are mounted with a hydraulic driving section 15 for driving the impacting mechanism 13, the rotating mechanism 9, the feed mechanism 12 and the rod exchange device 17, and an air driving section 16 for supplying the compressed air to the flushing mechanism 14. Furthermore, as detecting means 18 for detecting the striking force, rotating pressure, feed length (speed), and flushing pressure, there are provided in the hydraulic droving section 15 with an impacting force detector 19, a rotational pressure detector 20, a feed length detector 21, a feed pressure detector 22, and moreover, a flushing pressure detector 23 is provided in the air driving section 16.
Furthermore, a control unit 25 is provided in an operator cabin 24 on the running truck 5. The control unit 25 uses a computer having functions of storage, computation and control, and here, drilling data required for the control of the drilling such as drilling procedure, judgement of drilling condition, selection of drilling pattern, and the like is stored in advance.
Furthermore, in the vicinity of a driver's seat within the operator cabin 24, as shown in FIG. 4, there is provided adjacent to a manipulation lever 26 for manual drilling manipulation, with an input section 31 including a drilling length designation switch 27, a drilling length input button 28, an automatic start button 29, an emergency stop button 30. The input section 31 further includes a feed speed switch 32, a number of rods display device 33, a regular drilling length display device 34, and a reset button 35. The emergency stop button 30 is used to stop the operation at the time of emergency, and the feed speed switch 32 is used to manually set the feed speed. The number of rods display device 33 can always display the number of rods, and the regular drilling length display device 34 can display the drilling length during operation.
In the case of performing a drilling work by using the drilling control apparatus, the operator designates a drilling length by the drilling length designation switch 27, and sets the drilling length to the control unit 25 by depressing the drilling length input button 28. The setting of this drilling length employs an overwrite structure, and the data is semipermanently held so long as resetting is not performed by a reset button 35.
Then, if the start of drilling is commanded by depressing the automatic start button 29, the rock drill 10 starts advancement on the basis of program data of a drilling procedure stored in the control unit 25. In one example, the feed pressure is 40 Kg/cm 2 , and the feed speed is 900 mm/min.
When the end of the bit 6 reaches the rock which is the object of crushing, the rock arrival position is detected by the feed length detector 21, and it is inputted as a zero point into the control unit 25, and thereafter, a drilling length can be obtained by using this zero point as a reference point from detection data of the feed length detector 21. The decision of the arrival at the rock is made, for example, by observing that the feed speed is zero at the feed pressure >30 kg/cm 2 .
After the detection of the arrival at the rock, a start collaring process for positioning the end of the bit 6 is started, and when the start collaring has been performed for a predetermined length, the finish of the start collaring is detected, and a collaring process is started. After the collaring process of a predetermined length has been performed, the finish of the collaring is detected, and a real drilling process is started.
In the case of performing the drilling of a long hole, after finishing the drilling of a one-rod length, another rod is added to the rod 4 now in use, and after performing a collaring after the addition of the rod, the regular drilling is performed again. Thereafter, the drilling and the addition to the rod 4 are repeated. When the drilled length reaches the designated length, the drilling is finished.
The start collaring is performed by a procedure as shown in FIG. 5. For the drilling conditions at this time, an appropriate pattern is selected from various patterns stored in the control unit 25 depending on the angle of arrival at the rock and the kind of the rock. In one example, the start collaring is performed after detecting the zero point, at an impacting pressure of 120 kg/cm 2 , a feed pressure of 20 kg/cm 2 , a feed speed of 900 mm/min, the dust collector is turned ON, and by applying the striking force in an advancing direction for 3 seconds, and subsequently, screw fastening is performed at a rod rotational speed of 100 rpm for 0.8 seconds, and this is repeated for 2 times.
Next, the hole cleaning is performed for 3 seconds at a rod rotational speed of 100 rpm with weak flushing and the dust collector being turned ON, and the blockade of the hole is confirmed. It the flushing pressure is 7 kg/cm 2 or larger, it is judged that the hole is blocked, and the inching of 1 second is repeated at an impacting pressure of 120 kg/cm 2 , a feed pressure of 20 kg/cm 2 , a feed speed of 900 mm/min, strong flushing and the dust collector being turned ON. If the flushing pressure reduces to 6 kg/cm 2 or lower, it is judged that the hole blockade is resolved, and after retracting the rock drill 10 to the zero point, it is advanced at a feed pressure of 30 kg/cm 2 , a feed speed of 900 mm/min, a rod rotational speed of 100 rpm, and the dust collector being turned ON, and after confirming the drilled length, and if a predetermined start drilling length, for example, 200 mm is reached, the start collaring is finished.
When the finish of the start collaring is detected, a collaring process is started. The collaring process is performed in a procedure as shown in FIG. 6. Also for drilling conditions at this time, an optimum pattern is selected from various patterns stored in the control unit 25.
In one example, the collaring operation is performed at an impacting pressure of 120 kg/cm 2 , a feed pressure of 30 kg/cm 2 , a feed speed of 900 mm/min, a rod rotational speed of 100 rpm, weak flushing and the dust collector being turned ON, and a drilling length is confirmed, and if the drilling length reaches an intermediate position of collaring for example, a drilling length of 400 mm, the rock drill 10 is once retracted with fast feed to the start position of the collaring at a rod rotational speed of 100 rpm, weak flushing and the dust collector being turned ON. Thereafter, the collaring operation is performedagain at an impacting pressure of 120 kg/cm 2 , a feed pressure of 30 kg/cm 2 , a feed speed of 900 mm/min, a rod rotational speed of 100 rpm, weak flushing and the dust collector being turned ON, and a drilling length is confirmed, and if the drilling length reaches a predetermined collaring length of, for example, 700 mm, the collaring is finished.
During the collaring process, if it is judged that abnormality is caused in the drilling operation such as an increase in rotational resistance and a bit hole blockade as detected from the detection data showing an increase of the rotational pressure and an increase of the flushing pressure from the detection means 18, the control unit 25 makes the process shift to an abnormality avoiding process.
In the abnormality avoiding process, for example, the rock drill 10 is made to retract in fast feed at a rod rotational speed of 100 rpm with the dust collector being turned ON, and if the abnormality is resolved, the rock drill 10 returns to the original drilling condition.
When the finish of the collaring is detected, the real drilling process is started. During the collaring the drilling data including the impacting pressure, the rotational pressure, the feed length (speed), the feed pressure, and the flushing pressure is detected by each detector 19, 20, 21, 22, and 23, and stored in the control unit 25. Data of the drilling patterns of hard rock drilling, medium-hard rock drilling, soft rock drilling, clay layer drilling, crushing region drilling, and the like is stored in the control unit 25 so that an optimum drilling work can be performed depending on the property of the rock. The control unit 25 judges the property of the rock on the basis of the detection data at the time of the collaring and the conditions for the drilling operation at the time of starting the regular drilling are set.
The regular drilling process is performed in a procedure as shown in FIG. 7. In one example of hard rock drilling, the regular drilling operation is started at an impacting pressure of 120 kg/cm 2 , a feed pressure of 90 kg/cm 2 , a feed speed of 900 mm/min, a rod rotational speed of 100 rpm, strong flushing and the dust collector being turned ON.
During the regular drilling, the drilling data including the impacting pressure, the rotational pressure, the feed length (speed), the feed pressure, and the flushing pressure is detected by each detector 19, 20, 21, 22, and 23 of detecting means 18, and stored in the control unit 25. The control unit 25 always judges the condition such as hard or soft of the rock, the presence or absence of a crack, and the like on the basis of the detection data, and if there is a change in the condition, the setting of the drilling conditions is changed. For example, a change in the property of the rock is judged by the detection data of the rotational pressure, the flange pressure, the drilling speed, etc., and if the rotational pressure, the flange pressure, the drilling speed, etc., are increased, the process is shifted to another appropriate drilling pattern such as a medium-hard rock drilling pattern, a soft rock drilling pattern, a clay layer drilling pattern, a crush region drilling pattern, and the like.
When the rotational pressure, the flushing pressure, the drilling speed, and the like are decreased, the feed pressure and the impacting pressure are made to increase.
In the real drilling process, when the control unit 25 judges on the basis of the detection data including an increase in rotational pressure and an increase in flushing pressure, and the like, that abnormality in the drilling operation such as an increase in rotational resistance and a bit hole blockade has occurred, the control unit 25 makes the process shift to an abnormality avoiding process.
In the abnormality avoiding process, the rock drill 10 is retracted with fast feed, for example, at a rod rotational speed 100 rpm, strong flushing and the dust collector being turned ON, and when the abnormality is resolved, the process returns to the original drilling condition.
When the designated drilling length is longer than one rod length, after finishing the drilling of one rod length, another rod is added to the rod 4 in the rod exchanging device 17.
After finishing the addition to the rod 4, the collaring is performed. In the collaring after the addition of the rod, for example, the rock drill 10 is retracted with fast feed to the rear end of the guide shell 11 at a rod rotational speed 100 rpm, strong flushing and the dust collector being turned ON, and then, the rock drill 10 is advanced to a position 200 mm before the hole bottom at a striking pressure of 120 kg/cm 2 , a feed pressure of 30 kg/cm 2 , a feed speed of 900 mm/min, a rod rotational speed 100 rpm, strong flushing and the dust collector being turned ON, and hole cleaning is performed. After confirming that there is no abnormality such as jamming or the like, the rock drill 10 is again advanced to the hole bottom position at an impacting pressure of 120 kg/cm 2 , a feed pressure of 30 kg/cm 2 , a feed speed of 900 mm/min, a rod rotational speed 100 rpm, strong flushing and the dust collector being turned ON.
Thereafter, the rock drill 10 is advanced to perform the collaring operation at an impacting pressure of 120 kg/cm 2 , a feed pressure of 20 kg/cm 2 , a feed speed of 900 mm/min, a rod rotational speed 100 rpm, strong flushing and the dust collector being turned ON. By confirming the drilling length, if a predetermined collaring length, for example, advancement of 50 mm from the bottom position, has been drilled, the collaring finished.
When the collaring after the addition of the rod is finished, the real drilling is started. The control unit 25 stores during temporary stopping of the drilling operation for the addition of the rod, the drilling condition before the stopping, and at the time of restarting the real drilling, it is possible to set the conditions for the drilling operation similarly to that before the stopping and to restart the real drilling operation.
Thereafter, the drilling and the addition of the rod are repeated, and when the designated drilling length is reached, the drilling is finished.
As described above, the control unit 25 can automatically control the drilling operation from its start until the finishing without requiring cumbersome manipulation by the manipulation levers 26 and switches at the driver's seat by the operator. As a result, the fatigue of the operator can be reduced to a great extent. Furthermore, the drilling work is not affected by the individual difference depending on the skill level, and the drilling efficiency and the drilling precision including the linearity and the finished condition of the hole wall are improved.
Since the conditions for the drilling operation at the start of the real drilling are set by the control unit 25 by judging the property of the rock on the basis of the detection data at the time of collaring, it is possible to immediately perform the appropriate real drilling.
The control unit 25 judges during the drilling the presence or absence of the abnormality such as the increase of rotational resistance, the bit hole blockade, and the like on the basis of detection data including the increase in rotational pressure, the increase in flushing pressure, and the like, and at the time of abnormality, makes the rock drill 10 operate the operation to avoid the abnormality such as the retraction and the like. Accordingly, it is possible to prevent the expansion of the failure in the drilling and to return the rock drill 10 to the normal drilling condition at an early stage.
The control unit 25 stores during temporary stopping of the drilling operation, the drilling condition before the stopping, and sets the conditions for the drilling operation at the time of restarting the drilling operation similarly to that before the stopping. As a result, even when the drilling operation is temporary stopped due to the adding work of the rod, it is possible to restart the drilling work in an appropriate condition.
As described in the foregoing, in the control apparatus of a rock drill in the present invention, since the drilling control is automated, it is possible to reduce the fatigue of the operator, and to achieve the stable drilling precision and the drilling efficiency without being affected by the skill level of the operator. | A drilling control apparatus for automatically controlling the drilling operation of a rock drill includes a control unit for storing known criteria drilling patterns for various rock properties. A specific drilling pattern is selected based upon a collaring procedure for operation of the rock drill. A detector continually monitors variables such as rotational pressure, feed pressure and flushing pressure during the drilling process to determine a change in condition of the rock for determination of automatic selection of another more appropriate drilling pattern. | 4 |
BACKGROUND
1. Field of Invention
The present invention relates to integrated circuit packaging, and more particularly to multiple die packaging.
2. Related Art
Semiconductor die or chip packages are used to protect the semiconductor device (e.g., an integrated circuit chip) and allow the chip to be electrically connected to external circuitry. The chip typically has a surface containing active circuit elements that can be accessed via conductors on the chip, such as bonding pads. The chip can be packaged using numerous packaging techniques, as is known in the art. The package can then be placed into a printed circuit board (PCB) to access the circuitry on the IC chip.
As the complexity of applications increases, a greater number of chips are needed on the PCB to implement the necessary functions. Conventional methods to increase the number of chips without increasing the package size is to stack multiple chips on the package, such as disclosed in U.S. Pat. No. 5,012,323 to Farnworth, U.S. Pat. No. 5,291,061 to Ball, U.S. Pat. No. 5,347,429 to Kohno et al., U.S. Pat. No. 5,780,925 to Cipolla et al., U.S. Pat. No. 5,793,108 to Nakanishi et al., and U.S. Pat. No. 5,898,220 to Ball. Although these disclose two or more stacked die each electrically connected to leads on the package or lead frame, none disclose the ability to connect the die together without connection to the external package leads, which limits the interconnection capability of signals between die, such as the wire bond fan-out of the package.
In order to increase signal routing capability, previous solutions included using higher cost laminate-based packages. Thus, it is desirable to have a stacked multiple-die package with high signal routing capability between die without the costs associated with laminate-based packages.
SUMMARY
In the present invention, a method and structure are provided that allow multiple stacked die to be connected through internal conductive traces in the lead frame or package for high signal routing capability between die.
According to the present invention, electrically isolated signal traces within the paddle area are created for die-to-die signal interconnection and held together using lead lock tape. These signal traces are completely internal to the package and not connected to the external leads. Die are then stacked, either over each other or on both sides of the paddle area, and interconnected via the internal traces. A bond wire is connected from a bond pad of a first die to an internal trace. Another bond wire is connected from a bond pad of a second die to the internal trace to provide a desired interconnection between the two die.
This invention takes advantage of the metal in the lead frame paddle area to create internal “inner” lead traces (ILTs) for signal routing for die-to-die interconnection in stacked die lead frame packages. The “inner” leads complement the existing “outer” leads normally associated with lead frame design, which are used to provide electrical connection between the die and peripheral circuitry.
In one set of embodiments, a first die is mounted over the ILTs, such as with die attach paste or adhesive film, and a second die is mounted over the first die, such as with die attach paste or film adhesive. The first die and ILT area are designed such that there must be sufficient separation between the ILT area and the first die to allow wire connection to the ILTs. There must also be sufficient separation between the first and second die to allow wire connection to the bond pads from the first die.
In another set of embodiments, a first die is mounted over one side of the ILTs, and a second die is mounted on the other side of the ILTs, either with the active side (having the bond pads) or the inactive “back” side facing the ILT paddle area. If the second die is mounted with the active side facing the ILT paddle area, there must be sufficient separation between the top of the die the bottom of the ILT paddle area to allow proper wire connection to bond pads on the second die. If the first die is at least the same size as the ILT paddle area, the separation between the first die and the ILTs must be adequate to allow bond wire connection to the ILTs. This set of embodiments also allows a second die with center bond pads to be connected to the first die. The bond pads of the second die, mounted with the active side facing the ILTs, are connected to center portions of the ILTs, while the bond pads of the first die are connected to outer portions of the ILTs to facilitate the desired signal routing.
In other embodiments, the present invention provides additional benefits, such as allowing a larger lower die to be connected to external fingers of a lead frame while allowing the smaller upper die to be connected to ILTs without bond wires crossing each other. The ILT paddle area leads can be designed such that the ILT fingers extend beyond the tips of the external fingers in a interleaved fashion, i.e., the ends of the external fingers are closer to the die than the ends of the ILTs. With this configuration, a larger bottom die mounted on the ILT paddle area can be wire bonded to the external fingers, while a smaller top die mounted over the larger die can be wire bonded to the ILTs without crossing the bond wires of the top and bottom die.
Using conventional wire bonding techniques, the equivalent of a “via” can also be formed. Wire bonds are used to provide the out-of-plane electrical connections between crossing ILT segments of a specific die-to-die signal path. This allows routing of crossed die-to-die signal paths, similar to the way “vias” are used in multi-layer laminate substrates. These wire bond “vias” also overcome the inherent limitation of one-dimensional, or single metal layer, routing limitations of a lead frame.
The present invention will be more fully understood when taken in light of the following detailed description taken together with the accompanying drawings.
BRIEF DESCRIPTION OF THE DRAWINGS
FIG. 1 is a top view of a lead frame package for use in one embodiment of the present invention;
FIG. 2 shows a lead frame package formed from the package of FIG. 1 according to one embodiment of the present invention;
FIGS. 3A and 3B are respective top and side views of a lead frame package with stacked die according to one embodiment;
FIGS. 4 and 5 are side views of additional embodiments of the package shown in FIGS. 3A and 3B, in which the first and second die are on the same side of the internal traces;
FIGS. 6, 7 , and 8 are side views of different embodiments of the present invention, in which the first and second die are mounted on opposite sides of the internal traces;
FIGS. 9A, 9 B, and 9 C show another embodiment of the present invention, in which wire bond vias are used to route crossed signal path ILT segments; and
FIGS. 10A, 10 B, and 10 C show an embodiment of the present invention for wire bonding die to internal and external traces traces using interleaved bond fingers.
Use of the same or similar reference numbers in different figures indicates same or like elements.
DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS
The present invention provides a method and structure to allow inexpensive signal routing between stacked die in a lead frame by forming inexpensive interconnections between die using inner lead traces (ILTs) formed etching or stamping signal trace defining slots, then trimming the edge of the ILT paddle area to create electrically isolated traces.
FIG. 1 is a top view of an ILT lead frame package 10 , according to one embodiment, having a plurality of external lead fingers or outer lead traces (OLTs) 12 and an internal paddle area 14 containing slots 16 and traces 17 , where traces 17 are electrically connected. Lead frame package 10 is shown having slots 16 ending at three sides of the package. However, the lead frame package can be any suitable type, such as dual-sided or quad packages.
According to the present invention, the outer portions of paddle area 14 are removed or trimmed to create inner lead traces (ILTs) for die interconnection. In FIG. 1, dotted line 18 shows, for example, portions of paddle area 14 to be removed, such by trimming or cutting. Prior to removing the outer portions, a tape, such as a standard lead locking tape, is placed over an interior portion on either side of paddle area 14 , such as shown by dotted line 19 . The tape may also serve as a permanent plating mask for plating the tips of the ILTs.
FIG. 2 shows lead frame package 10 after removal of the outer portions of paddle area 14 . Traces 17 are no longer electrically connected to other traces. Instead, each resulting inner lead trace 20 is electrically isolated from other ILTs 20 . As shown in FIG. 2, ILTs 20 can carry signals to and from adjacent sides or to and from opposite sides of paddle area 14 . It should be noted that the package shown in FIG. 2 can be modified so that ILTs 20 can carry signals to and from the perimeter and the interior of paddle area 14 for die with center bond pads. To achieve this, an interior portion of paddle area 14 is removed, such that ILTs 20 have ends at the perimeter and interior of paddle area 14 . This is in contrast to package 10 of FIG. 2, in which ILTs 20 have ends only at the perimeter of the paddle area. Die can then be attached and stacked onto package 10 . Subsequent wire bonding electrically couples the die to OLTs 12 for connection to other circuitry, such as through a PCB. Wire bonding also electrically couples the stacked die to provide the desired signal routing or interconnections between the die.
FIGS. 3A and 3B are respective top and side views of lead frame package 10 with a first die 30 and a second die 31 . Note that these and other figures show only two die. However, as those skilled in the art will appreciate, more than two die can be used with the present invention. First die 30 is secured to an inner lead trace (ILT) tape 32 , such as a standard lead locking tape discussed above, by a non-conductive film or a less expensive die attach paste 33 . Note that tape 32 may also be placed on the bottom of ILT 20 with first die 30 secured directly to ILT 20 using non-conductive film or paste 33 . In this embodiment, first die 30 is smaller than the ILT area so that the ends of ILTs 20 are exposed for wire bonding. Second die 31 is mounted to first die 30 , such as with die attach paste 33 . In this embodiment, second die 31 is smaller than first die 30 to allow wire bonding to bond pads 34 on first die 30 . Thin conductive bond wires 35 , such as gold, can be connected between bond pads 36 of second die 31 and selected ones of ILTs 20 . Bond wires 35 can also be connected between bond pads 34 of first die 30 and the same selected ones of ILTs 20 to provide the desired die-to-die interconnection. In addition, bond wires 35 can be connected between bond pads 36 of second die 31 and OLTs 12 , ILTs 20 , or bond pads 34 of first die 30 , between bond pads 34 of first die 30 and OLTs 12 or ILTs 20 , and between OLTs 12 and ILTs 20 . Using various combinations of these connections paths allows desired die-to-OLT connections and die-to-die interconnections to be formed, after which, the package can be encased, such as in a mold compound 37 .
FIGS. 4 and 5 show some alternative embodiments to the package shown in FIGS. 3A and 3B, in which both die are stacked on one side of the ILTs. In FIG. 4, second die 31 is approximately the same size as first die 30 , although second die 31 can also be larger. In this embodiment, after first die 30 is mounted over ILTs 20 , such as by ILT tape 32 and die attach paste 33 , bond wires are attached to bond pads 34 of first die 30 . Second die 31 is then attached to first die 30 with a spacer 40 , such as a thick non-conductive adhesive or die attach tape or a solid spacer attached to the two die by adhesive. If a solid spacer is used, the solid spacer can be made of a conductive material, such as a metal, or a non-conductive material, such as a polymer or ceramic. Further, the adhesive between the solid spacer and the top or active side of the die is non-conductive, while the adhesive between the solid spacer and the bottom or inactive side of the die can be conductive or non-conductive, depending on the electrical function, such as described in commonly-owned U.S. patent application Ser. No. 09/828,396, entitled “Making Semiconductor Devices Having Stacked Dies With Biased Back Surfaces”, now U.S. Pat. No. 6,437,449, issued Aug. 20, 2002, which is incorporated by reference in its entirety. Spacer 40 should provide enough separation between first die 30 and second die 31 to allow clearance of bond wires 35 from bond pads 34 .
In FIG. 5, an exposed thermal pad 50 is attached underneath ILTs 20 by ILT tape 32 or adhesive. In this embodiment, ILT tape 32 may or may not also be attached to the other side of ILTs 20 (FIG. 5 shows no ILT tape 32 ). Thermal pad 50 is exposed to the exterior of the package to provide a solderable thermal path. In other embodiments, a heat slug or other similar element can be used instead of thermal pad 50 .
In other embodiments, shown in FIGS. 6, 7 , and 8 , first die 30 and second die 31 are on opposite sides of ILTs 20 , instead of on the same side, as discussed above. In FIG. 6, the side of second die 31 containing active circuitry and bond pads is attached to the side of ILTs 20 opposite first die 30 . Non-conductive die attach paste 33 or adhesive film secures second die 31 to ILTs 20 . Also note that ILT tape 32 may be placed on top, bottom, or both sides of ILTs 20 . As shown in FIG. 6, second die 31 is larger than the ILT area, which allows wire bonding to bond pads 36 of second die 31 . First die 30 can also be the same size as or larger than the ILT area. In this case, there must be sufficient separation between the ILT area and first die 30 to allow wire bonding to the ILTs. After bond wires 35 are connected to bond pads 36 of second die 31 , a spacer such as thick non-conductive paste or a solid spacer with adhesive, as discussed above, provides the desired separation and attachment between first die 30 and ILTs 20 . Other variations of the package shown in FIG. 6 include features discussed above, such as first die 30 being larger than the ILT area and having an exposed thermal pad or heat slug attached to second die 31 .
In FIG. 7, the inactive side of second die 31 is attached to ILTs 20 . Adhesive 33 attaching second die 31 to ILTs 20 can be conductive or non-conductive. When electrical backside contact to first die 30 or second die 31 is desired, ILT tape 32 between the corresponding die and ILT 20 has openings to the appropriate electrical conductors so that electrical contact to the die backside may be made through the conductive adhesive. This may be done with one or both die. The bond fingers of ILTs 20 are plated on both sides to allow wire bonding from both die. Again, other variations are possible, such as first die 30 being the same size as or larger than the ILT area and/or the package having an exposed thermal pad or heat slug.
In FIG. 8, second die 31 has center bond pads 80 in addition to outer bond pads 36 . The paddle area is formed, as discussed above, with ILTs 20 having terminals at both the perimeter and interior of the paddle area. Second die 31 is attached to ILTs 20 , such as described above. Bond wires 35 are attached to outer bond pads 36 and center bond pads 80 as required. First die 30 is then attached to ILTs 20 , again as discussed above, and wire bonded.
FIGS. 9A, 9 B, and 9 C show another embodiment of the present invention, which can be applied to any of the previous embodiments. This shows how crossed signal paths within the ILT can be used to route signals between die using wire bonds or allow signals to be routed within the same die, both of which are functionally similar to vias. FIG. 9A shows a package where these vias can be formed both at the interior of the paddle area at region 90 and at the exterior of the paddle area at region 91 . FIG. 9B shows a top view of ILTs 20 at interior region 90 . Dotted line 92 shows an opening in the ILT tape 32 to expose portions of ILTs 20 for connection. As seen, selected segments of ILTs 20 can be electrically connected by wires 93 , providing electrically isolated but crossed signal paths between die, or a die may be wire bonded to one or more of the ILTs 20 to provide the desired connection between different portions of the die. FIG. 9C shows a top view of ILTs 20 at exterior region 91 . The right of dotted line 94 are exposed portions of ILTs 20 not covered with the ILT tape 32 . Similar to FIG. 9B, selected segments of ILTs 20 are wire bonded together, thereby providing a desired interconnection between die or within a die.
FIGS. 10A, 10 B, and 10 C show an embodiment of the present invention that allows a smaller upper die to be wire bonded to internal lead traces and a larger lower die to be wire bonded to outer or external leads without crossing upper and lower bond wires. FIG. 10A shows a portion of a lead frame package having external leads 100 and internal leads 102 . Internal leads 102 are exposed above dotted line 104 , underneath which indicates the ILT tape 32 . As seen from FIG. 10A, external leads 100 and internal leads 102 are electrically connected at portions 106 prior to trimming to allow a conventional lead frame manufacturing process. FIG. 10B shows the portion of the lead frame of FIG. 10A after trimming away portions 106 , resulting in electrical isolation of interleaved external leads 100 and internal leads 102 . The ends of internal leads 102 extend beyond the ends of external leads 100 , which are now closer to the die. This allows a smaller upper die 110 to be wire bonded to the internal leads and a larger lower die 120 to be wire bonded to the external leads without crossing bond wires 125 , as shown in FIG. 10 C.
The above-described embodiments of the present invention are merely meant to be illustrative and not limiting. It will thus be obvious to those skilled in the art that various changes and modifications may be made without departing from this invention in its broader aspects. For example, the above specification describes multiple die counted on a lead frame with lead fingers for connection to PCBs. However, other types of lead frames are also suitable for use with the present invention, such as micro lead frames, which have leads in the form of lands on the bottom surface of the package. Further, stacked-die packages are shown, although other types of arrangements are also suitable, such as multi-die single layer configurations or a combination of both. Therefore, the appended claims encompass all such changes and modifications as fall within the true spirit and scope of this invention. | A multiple die package is formed, which allows multiple die to be interconnected using internal leads or traces from a lead frame. A plurality of slots in the paddle area of the lead frame are created which define the internal signal traces. Then the outer portions of the die paddle area of the lead frame are removed or trimmed to isolate the internal traces from each other and form a plurality of individual internal leads. Multiple die, either stacked, in a planar array, or a combination of the two, are connected to selected internal leads, such as by wire bonding, to form the desired die-to-die interconnections for routing signals between die without interfering with normal wire bond fan-out. A tape can be adhered to the interior portion of the die paddle area prior to trimming to hold the internal traces in place and leave the ends of the traces exposed for wire bonding to the die. The internal traces also allow connections to be made within a single die by wire bonding selected bond pads from the die via one or more of the internal traces. | 7 |
BACKGROUND OF THE INVENTION
Field of the Invention
[0001] Dishwashers with adjustable racks are known in the art. Typically, such adjustable racks must be empty and moved out of the washing chamber to permit the height of the rack to be adjusted. Also, the lift mechanism for adjusting the height of the rack normally occupies space within the rack, thereby decreasing the area of the rack which can be used for placing dishes, glasses, and other objects to be washed. Also, such adjustable racks normally raise or lower one side of the rack and then the other side of the rack in sequential steps.
[0002] Accordingly, a primary objective of the present invention is the provision of a dishwasher having an improved adjustable rack.
[0003] Another objective of the present invention is the provision of an adjustable rack for a dishwasher which can be raised and lowered when positioned in or out of the washing chamber.
[0004] Another objective of the present invention is the provision of an adjustable rack for a dishwasher which can be raised and lowered when unloaded or loaded with objects to be washed.
[0005] A further objective of the present invention is the provision of a dishwasher having an adjustable rack wherein the lift mechanism is housed within the sidewalls of the dishwasher.
[0006] Still another objective of the present invention is the provision of a dishwasher having an adjustable rack wherein the lift mechanism does not occupy space within the rack.
[0007] A further objective of the present invention is the provision of an adjustable rack for a dishwasher wherein both sides of the rack are raised or lowered simultaneously.
[0008] Another objective of the present invention is the provision of a dishwasher having a rack wherein the height of the rack within the washing chamber can be manually adjusted.
[0009] Still another objective of the present invention is the provision of a dishwasher having a rack wherein the height of the rack within the washing chamber can be adjusted via a switch or button on the control panel of the dishwasher.
[0010] A further objective of the present invention is the provision of a dishwasher having an adjustable rack which is economical to manufacture and durable and efficient in use.
[0011] These and other objectives will become apparent from the following description of the invention.
SUMMARY OF THE INVENTION
[0012] The dishwasher of the present invention includes a washing chamber defined by opposite sidewalls, a top wall, a bottom wall, and a back wall. One or more racks are provided within the chamber for holding objects to be washed. The racks can be moved horizontally into and out of the washing chamber for loading and unloading the objects to be washed.
[0013] One or more of the racks is vertically adjustable to accommodate different sized objects to be washed. A lift mechanism is provided in the opposite sidewalls of the dishwasher and is operatively connected to the adjustable rack for raising and lowering the rack. The lift mechanism includes guide tracks extending vertically in the opposite sidewalls, and guide blocks movably mounted within the guide tracks. The guide blocks are interconnected by cables such that the opposite sides of the rack are raised or lowered simultaneously. The cables are connected to a drum gear which is rotated by a worm gear. In one embodiment, the worm gear is mounted on a shaft with a handle for manually turning the worm gear to raise and lower the rack. In another embodiment, an electric motor is connected to the worm gear and to a switch on the control panel for raising and lowering the rack.
BRIEF DESCRIPTION OF THE DRAWINGS
[0014] [0014]FIG. 1 is a front view of the dishwasher with the door open and the middle adjustable rack in a lower position.
[0015] [0015]FIG. 2 is a schematic perspective view of the lift mechanism for the adjustable rack of the present invention.
[0016] [0016]FIG. 3 is a front schematic view of the lift mechanism.
[0017] [0017]FIG. 4 is a side elevation view of the left-hand portion of the lift mechanism.
[0018] [0018]FIG. 5 is a side elevation view of the right hand portion of the lift mechanism.
[0019] [0019]FIG. 6 is a sectional view taken along lines 6 - 6 of FIG. 5.
[0020] [0020]FIG. 7 is a perspective view of the drum gear.
DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENT
[0021] In the drawings, the reference numeral 10 generally designates a dishwasher. The dishwasher 10 includes a washing chamber 12 defined by opposite sidewalls 14 , 16 , a top wall 18 , a bottom wall 20 , and a rear wall 22 . A door 24 is pivotally mounted to the dishwasher 10 for movement between open and closed positions. The dishwasher 10 includes upper and lower spray arms 26 , 28 .
[0022] As seen in FIG. 1, the dishwasher 10 includes an upper rack 30 , a lower rack 32 , and a middle rack 34 . It is understood that one of the racks can be eliminated such that the dishwasher only has two racks. Each of the racks 30 , 32 and 34 are moveable in a horizontal plane between a position within the washing chamber 12 and a position substantially outside the washing chamber 12 for loading and unloading objects to be washed. The lower rack 32 includes wheels 36 which ride along a ledge or lip 38 adjacent the opposite sidewalls 14 , 16 of the dishwasher 10 . The upper rack 30 includes rollers 40 which roll along guide rails 42 , which in turn can be horizontally moved between upper and lower guide rollers 44 mounted on each of the sidewalls 14 , 16 .
[0023] The above structure of the dishwasher 10 is conventional and does not constitute a part of the present invention.
[0024] The present invention is directed towards the vertical adjustability of one of the racks. In the drawings and in the following description, the middle rack 34 is designated as the adjustable rack, though it is understood that the lift mechanism for adjusting the height of one of the racks can be utilized on any of the racks within the dishwasher 10 .
[0025] The lift mechanism for raising and lowering the middle rack 34 is best seen in FIGS. 2 - 5 of the drawings. Generally, the lift mechanism is a cable system with an actuator for raising and lowering the middle rack 34 within the washing chamber 12 . The lift mechanism is housed within the sidewalls 14 , 16 of the dishwasher 10 , and thus does not take up space within the rack 34 .
[0026] More particularly, each sidewall 14 , 16 has a C-shaped guide track 46 , 47 mounted therein, respectively. Slidably mounted within each guide track 46 , 47 is a guide block 48 , 49 , respectively, which are movable upwardly and downwardly within the guide tracks 46 , 47 . An arm 50 is fixed to and cantilevered from each guide block 48 , 49 . The arms reside within the washing chamber 12 adjacent the opposite sidewalls 14 , 16 . Each arm 50 includes four rollers 52 which receive guide rails 54 . The rack 34 includes rollers 56 rollably mounted within the guide rails 54 . Accordingly, the rollers 56 can roll horizontally through the guide rails 54 , which in turn can roll along the rollers 52 such that the middle rack 34 can be moved into and out of the washing chamber 12 .
[0027] The lift mechanism includes a set of cables 58 , 60 , 62 . The first cable 58 has a first end 64 secured to a drum gear 66 rotatably mounted within the left sidewall 14 . The cable 58 wraps around the drum gear 56 in a first circumferential groove 68 , and has a second end 70 secured to the top of the guide block 48 . The second cable 60 has a first end 72 secured to the bottom of the guide block 48 . The cable 60 extends downwardly around a pulley 74 mounted at the lower end of the guide track 46 in the sidewall 14 , and then upwardly over the top wall 18 . The second end 76 of the cable 60 is secured to the top of the guide block 49 . The third cable 62 has a first end 78 attached to the guide block 49 . The cable 62 extends downwardly around a pulley 80 rotatably mounted in the guide track 47 in the sidewall 16 , and then upwardly over the top wall 18 . The opposite end 82 of the cable 62 extends around the drum gear 66 in a second groove 84 thereof and is secured to the drum gear 66 . The cables 58 , 62 extend around the gear drum 66 in opposite directions, such that upon rotation of the drum gear 66 , one cable is wound onto the drum gear 66 and the other cable is unwound from the drum gear 66 .
[0028] The ends of the cables 58 , 60 , 62 can be attached in any convenient manner to the drum gear 66 and guide blocks 48 , 49 . For example, as best seen in FIG. 4, a nodule 86 is provided on the end 64 of the cable 58 and the end 82 of the cable 62 are adapted to be matingly received within cavities or recesses 88 in the drum gear 66 . Similar cavities or recesses are provided in the guide blocks 48 , 49 to receive the nodule 86 on the cable ends connected to the guide blocks 48 , 49 .
[0029] The drum gear 66 includes perimeter teeth 90 which mesh with a worm gear 92 . The worm gear is mounted on a shaft 94 for rotation therewith. An actuation handle 96 is mounted on the forward end of the shaft 94 and is positioned adjacent the front opening of the washing chamber 12 for access when the door 24 is opened. Upon manual turning of the handle 96 in the clockwise position, the worm gear 92 rotates in a counterclockwise direction, as seen in FIG. 4, so as to further wrap the cable 58 around the drum gear 66 and to unwrap the cable 62 from the drum gear 66 , thereby raising the guide blocks 48 , 49 within the guide tracks 46 , 47 so as to raise the middle rack 34 within the washing chamber 12 . Turn the handle 96 in a counterclockwise direction rotates the drum gear 66 in a clockwise direction, thereby unwrapping the cable 58 from the drum gear 66 and wrapping the cable 62 further around the drum gear 66 so as to pull the guide blocks 48 , 49 downwardly within the guide tracks 46 , 47 thereby lowering the middle rack 34 within the washing chamber 12 .
[0030] Preferably, the shaft 94 is square or hex-shaped and slidably extends through the worm gear 92 . Thus, the handle 96 can be moved from a position next to the front opening of the washing chamber 12 such that the door 24 can be closed, and pulled outwardly a short distance away from the front opening of the washing chamber 12 when the door 24 is opened so as to provide easy turning of the handle 96 by a user. The sidewall 14 includes a recess 98 to house the handle 96 when in the retracted or inoperative position, as best seen in FIG. 1.
[0031] The cables 60 , 62 extend through flexible conduits 100 extending over the top wall 18 of the dishwasher 10 . The conduits 100 terminate at each end in a bushing 102 which is slidably mounted within a channel insert 104 adjacent the top of the guide tracks 46 , 47 . A spring 106 is provided within the channel insert 104 . As the cables 60 , 62 are pulled downwardly through the channel insert 104 , the spring 106 compresses to provide feedback to the user as the guide blocks 48 , 49 reach the end of their travel within the guide tracks 46 , 47 of, if the dishes start to compress or contact the underside of upper rack 30 . Thus, the user knows when to stop turning the handle 96 .
[0032] In an alternative embodiment, the cable 62 can be eliminated, with the lowering of the rack 32 occurring by gravity when the handle 96 is turned in a counterclockwise direction.
[0033] As a further alternative, a small electric motor (not shown) can be operatively connected to the drum gear 66 , with a control switch provided on the control panel of the dishwasher 10 . Thus, the lift mechanism can be quickly and easily actuated via the switch.
[0034] The invention has been shown and described above with the preferred embodiments, and it is understood that many modifications, substitutions, and additions may be made which are within the intended spirit and scope of the invention. From the foregoing, it can be seen that the present invention accomplishes at least all of its stated objectives. | A dishwasher is provided with an adjustable rack that can be moved upwardly and downwardly within the washing chamber to accommodate different sized objects to be washed. The lift mechanism for the rack is housed within the sidewalls of the dishwasher. The lift mechanism employs a cable system to raise both sides of the rack simultaneously, with the rack positioned within or outside the washing chamber and with the rack either loaded or unloaded. In one embodiment, the lift mechanism is manually actuated by turning a handle. In another embodiment, the lift mechanism includes an electric motor with a switch on the control panel for raising and lowering the rack. | 8 |
FIELD OF THE INVENTION
This disclosure relates to authentication and verification in the computer and data security fields, and more particularly to authentication or qualification of a device.
BACKGROUND
Authentication is well known in the computer/cryptographic fields; typical applications are to ensure that another party (or entity) in a communications context is properly identified. An example of such authentication is that distributors of music and video content using the Internet or other computer networks do so using a Digital Rights Management system (DRM) to protect the content from illicit copying and use. DRM is used to protect digital content transferred over a network and transferred from a computer to an associated playback device. The DRM system is implemented by software resident in the host and audio/video player or associated computer. It is often desirable to make sure that the playback device is an authenticated device as part of the DRM system.
So it is known to first authenticate such a device intended to receive such content (or other valuable information) before transmitting to the device any valuable or important information. More broadly, authentication is a way to verify the identity of another device or entity for purposes of sending information to or receiving information from that other entity.
SUMMARY
This disclosure is directed to a “lightweight” (meaning relatively fast to compute with limited computing resources) authentication or qualification method and associated system and apparatus for authenticating third-party devices of diverse sources by a host, using prior delivery of shared secret information to the device manufacturer or supplier. (“Host” as used generally refers to a computing apparatus with which the device desires to communicate.) This method employs a zero-knowledge based authentication process. In cryptography, a zero-knowledge protocol is an interactive method for a party to prove to another that some statement is true, without revealing to the party information other than the truth of the statement. The present method is another way to authenticate and so is not zero-knowledge.
In this method, the host implementor generates a set of N (N being an integer) batches of randomly generated data, each batch designated D Bi where i=0 to N−1, along with a set of M (M being an integer) randomly generated fixed-size cryptographic keys each designated D aki where i=0 to M−1. (The data and keys are the shared secret information so this is not a true zero-knowledge authentication protocol.) The size of each data batch is not limiting but is for instance in the range of a few thousand bytes.
A randomly selected data batch designated D B having an assigned unique identifier id (identification number) designated D Bid (where 0<=id<N) and a randomly selected key designated D ak having an assigned unique identifier id (identification number) designated D akid (where 0<=id<M) is provided to the manufacturer of the third-party device i, where i is an index designating e.g. one device. The association between the device identifier (ID) pair which is designated D Bid ,D akid and the device is stored at the host, e.g., in computer readable memory. In some embodiments, a single identifier rather than a pair is used for each device.
At arbitrary times during the life cycle of the host, the host requests that the third-party device authenticate itself by computing a keyed hash of a selected portion of its data batch and return its computed hash value (digest), along with its identifier pair (D Bid ,D akid ).
The host can immediately decide to sever communication with the device should it determine that the received identifier pair (D Bid ,D akid ) has been revoked. Should that identifier pair still be valid, the host, having prior knowledge of the associated device data batch and authentication key, is able to verify the validity of the requested data and hence the device. As long as the verification does not fail, the host has no reason to distrust the third-party device and continues to communicate with it. Should verification (authentication) fail, the host may decide to sever communication with the third-party device.
Message authentication codes using hash functions or keyed ciphers are well known in the data security field. The principle is to take data (a digital message, digital signature, etc.) and use it as an entry to e.g. a hash function or keyed cipher, resulting in an output called a “digest” of predetermined length which is intended to uniquely identify (“fingerprint”) the message. A secure (cryptographic) hash or cipher is such that any alteration in the message results in a different digest, even though the digest is much shorter than the message. Such functions are “collision-resistant” and “one-way.” Some “keyed” hash functions (as described here) conventionally are keyed in the way a particular cipher is keyed.
BRIEF DESCRIPTION OF THE FIGURES
FIG. 1 shows a system in accordance with the invention.
FIG. 2 shows graphically a method in accordance with the invention.
FIG. 3A shows a device in accordance with the invention.
FIG. 3B shows a host in accordance with the invention.
FIG. 4 shows detail of a generic computing device suitable for use as the FIG. 3A device or FIG. 3B host.
DETAILED DESCRIPTION
The present invention in some embodiments is used in the exemplary system 10 depicted in FIG. 1 in which each element is largely conventional. In a first embodiment, host 14 is, e.g., a computer server platform such as a server in a DRM (digital rights management) system for distribution and protection of copyrighted digital content. In a second embodiment, host 14 is e.g. a desktop or laptop computer, Smart Phone, audio/video player or other end user computing apparatus. Host 14 is coupled to a communications link 16 such as the Internet in the first embodiment, but which could be another type of communication network, wired or wireless including Ethernet, cellular telephone, etc. In the second embodiment, the communications link is a more local type wired or wireless link such as a USB (universal serial bus), Fire Wire, or internal computer bus. In both embodiments, also coupled to link 16 are one or more (client) devices 20 , 22 , . . . , 26 which are e.g. in the first embodiment consumer electronic devices, other types of computing devices, Smart phones, etc., here respectively designated device 1 , device 2 , . . . , device i. In the second embodiment, devices 20 , 22 , . . . , 26 are e.g. computer or consumer electronic device accessories or components or peripherals such as a computer display screen, a computer optical or hard disc drive, a USB key, or other electronic device which is internal or external to the host and communicates therewith. In this second embodiment, in addition to the security aspect, the present method has the commercial and reliability advantages of allowing only authenticated (qualified) devices to be coupled to or installed in the host, preventing interoperability problems.
At the time of manufacturing (or initialization) of these third-party devices, the organization or person operating or manufacturing the host 14 conventionally establishes a master array or set of N batches D Bi of random data, and M random fixed-size cryptographic keys D aki . This master array is stored in memory located in or associated with the host and remains there for the lifetime of the host.
As new third-party devices such as 20 , 22 , 26 come to life (e.g., are manufactured or initialized), identifier id (identification number) pairs (D Bid ,D akid ) are assigned uniquely to each of these device models and the corresponding data D B and key D ak are distributed to the device manufacturer by the system implementer (who typically also maintains or manufactures the host) for inclusion (e.g., storage in memory) into each device. A given device model (instance or unit), therefore, stores only one of the many data batches and one of the many keys known by the host.
As the host is updated by the implementer, should the authentication of particular devices be revoked for the purposes of this authentication, the revoked identifier pairs are conventionally recorded at the host as being revoked.
The following authentication process then takes place at arbitrary times during the life of each third-party device, at the prerogative of the host. For this process, it is assumed that each device has stored in it a data batch D B , of size (length) designated D Bsz and the associated data batch identifier designated D Bid and a fixed-size authentication key D ak and the associated key identifier designated D akid as earlier assigned by the host implementer to the manufacturer of the device and as installed into memory in the device as explained above. The key length is, e.g., conventionally about 20 bytes but this (like the other numerical parameters described here) is not limiting.
Furthermore, the process assumes that each such device i can perform a MAC computation such as a keyed hash computation (e.g., the well known HMAC-SHA1 function as defined in RFC 2104 or other keyed hash functions, of which many are known) using the data batches and keys or alternatively a keyed cipher-based MAC computation. HMAC stands for Hash Message Authentication Code (a keyed hash function). The present MAC computation is typically done by an appropriately programmed processor or dedicated logic circuitry resident in the device as explained in further detail below. The notation HMAC(K, D) below indicates the HMAC computation of generic data D using generic key K. More generally, the authentication may use any message authentication code process, including a cipher based MAC.
The authentication process, as depicted with time running along the vertical axis in FIG. 2 for the host and device, includes:
1. The host (which is a computing apparatus as explained above) generates a fixed-size random number as an authentication nonce H an . (A nonce in cryptography is a random number used once to avoid a replay attack by making each exchange unique.) The nonce is, e.g., of about the same length as the intended hash digest such as about 20 bytes.
2. The host also generates a random offset value designated H do and a random length value designated H dl such that H do +H dl is less than or equal to the total size (e.g., in bits or bytes) D Bsz of the data batch D B held by the device. These “random” number generations may be performed conventionally, for instance by conventional pseudo random number generator software executed by a processor in the host.
3. The host sends (via communications link 16 to which it is conventionally coupled in FIG. 1 the nonce H an , the data offset H do and the data length H dl (which collectively are the data batch selection parameters) generated in steps 1 and 2 to the device. These particular selection parameters are only exemplary.
4. The host sends (via the communications link 16 ) a request to the device to return the computed authentication hash digest value D ah . (Steps 3 and 4 may be combined into one transmission or reversed in order.)
5. The device (also a computing device, see above) computes, e.g., the MAC digest value D ah =HMAC(D ak , ∥D B [H do . . . H do +H dl −1]), that is, the predetermined HMAC or keyed cipher MAC function as keyed by the device key D ak , of the data, where the data is the concatenation of the host nonce H an and the subset of the data batch D B specified as being offset H do and of length H dl in data batch D B .
6. The device sends to the host via the communications link the computed authentication digest value D ah computed in step 5, with its batch identifier which is D Bid and its key identifier which is D akid (which together are the ID pair).
7. The host verifies whether the received ID pair (B Did , D akid ) has been revoked. If so, the host elects to sever communication with the device immediately and the process stops. An error message may be sent to the device by the host at this point.
8. If there is no revocation, then using the received batch identifier D Bid and key identifier D akid , the host using that received ID pair looks up the associated data batch B D and key D ak in its storage and using them and the earlier generated selection parameters H an , H do , H al independently computes the equivalent MAC digest D ah . Note that the data batches do not need each to be stored as a separate entry in the host. Instead the data batches may overlap in the host memory to economize on host memory, and looked up using an addressing scheme with offsets or other conventional addressing techniques. The host then conventionally compares this computed MAC digest D ah to the authentication value D ah received from the device.
If the verification of step 8 fails (no match of the two digests), the host determines that the device is not an authenticated device and severs its communication with the device (e.g., sends an error message or just stops communications). But as long as this authentication exchange is completed successfully (the two digests do match), the host has no reason to distrust that the particular device is authenticated and may continue to communicate with it, in other words the authentication is successful.
FIG. 3A shows in a block diagram relevant portions of exemplary device 20 . Non-relevant portions of the device (those not involved in the authentication process) are conventional and not shown, for ease of illustration. Device 20 includes a conventional access port which is adapted to couple to the external communications link 16 . Incoming data or requests are sent to storage (memory such as RAM) 32 or conventional processor 40 as shown. (The processor may be the main processor for the device which also performs other functions, or may be a processor or circuit dedicated to the authentication task.) Also provided is storage 34 (e.g., ROM) which holds the factory installed data, key and ID pair as shown. Also provided is storage 38 (e.g., ROM) storing code (computer software) such as the MAC computation software 40 (“MAC function”) to be executed by processor 40 . The output of the MAC function 44 is stored in storage (e.g., RAM) 48 also coupled to port 30 .
An example of host 14 is depicted in similar block diagram form in FIG. 3B , with many similar elements. Port 31 supports two way communications to link 16 . Incoming data (the digest and ID pair from the device) is stored in memory (e.g., RAM) 33 . Processor (or equivalent) 41 executes code provided from code memory 39 to do the PRNG calculation in PRNG 43 and the MAC computation in calculator 45 . Memory 35 (RAM or ROM) stores the ID pairs and associated data batches and keys. Comparator 47 in processor 41 verifies both the key pairs and the incoming device digests as explained above. Verifier 49 then severs communications or not. Note that the comparator and verifier also me in the form of software executed by the processor. Both are conventional functions.
FIG. 4 shows further conventional detail of the FIG. 3A device (or the FIG. 3B host) in one embodiment. FIG. 4 illustrates a typical and conventional computing system 60 that may be employed to implement processing functionality in embodiments of the invention. Computing systems of this type may also be used in a computer host (server) or user (client) computer or other computing device or peripheral or accessory or component as described above, for example. Those skilled in the relevant art will also recognize how to implement embodiments of the invention using other computer systems or architectures. Computing system 60 may represent, for example, a desktop, laptop or notebook computer, hand-held computing device (personal digital assistant (PDA), cell phone, consumer electronic device, palmtop, etc.), mainframe, server, client, or any other type of special or general purpose computing device such as a peripheral or accessory or component as explained above as may be desirable or appropriate for a given application or environment. Computing system 60 can include one or more processors, such as a processor 64 (equivalent to processor 40 in FIG. 3A ). Processor 64 can be implemented using a general or special purpose processing engine such as, for example, a microprocessor, microcontroller or other control logic. In this example, processor 64 is connected to a bus 62 or other communications medium. Note that in some embodiments the present process is carried out in whole or in part by “hardware” (dedicated circuitry) which is equivalent to the above described software embodiments.
Computing system 60 can also include a main memory 68 (equivalent to memories 32 , 48 in FIG. 3A ), such as random access memory (RAM or read only memory (ROM)) or other dynamic memory, for storing information and instructions to be executed by processor 64 . Main memory 68 also may be used for storing temporary variables or other intermediate information during execution of instructions to be executed by processor 64 . Computing system 60 may likewise include a read only memory (ROM) or other static storage (equivalent to memories 34 , 38 in FIG. 3A ) device coupled to bus 62 for storing static information and instructions for processor 64 .
Computing system 60 may also include information storage system 70 , which may include, for example, a media drive 72 and a removable storage interface 80 . The media drive 72 may include a drive or other mechanism to support fixed or removable storage media, such as flash memory, a hard disk drive, a floppy disk drive, a magnetic tape drive, an optical disk drive, a compact disk (CD) or digital versatile disk (DVD) drive (R or RW), or other removable or fixed media drive. Storage media 78 may include, for example, a hard disk, floppy disk, magnetic tape, optical disk, CD or DVD, or other fixed or removable medium that is read by and written to by media drive 72 . As these examples illustrate, the storage media 78 may include a computer-readable storage medium having stored therein particular computer software or data.
In alternative embodiments, information storage system 70 may include other similar components for allowing computer programs or other instructions or data to be loaded into computing system 60 . Such components may include, for example, a removable storage unit 82 and an interface 80 , such as a program cartridge and cartridge interface, a removable memory (for example, a flash memory or other removable memory module) and memory slot, and other removable storage units 82 and interfaces 80 that allow software and data to be transferred from the removable storage unit 78 to computing system 60 .
Computing system 60 can also include a communications interface 84 (equivalent to port 30 in FIG. 3A ). Communications interface 84 can be used to allow software and data to be transferred between computing system 60 and external devices. Examples of communications interface 84 can include a modem, a network interface (such as an Ethernet or other network interface card (NIC)), a communications port (such as for example, a USB port), a PCMCIA slot and card, etc. Software and data transferred via communications interface 84 are in the form of signals which can be electronic, electromagnetic, optical or other signals capable of being received by communications interface 84 . These signals are provided to communications interface 84 via a channel 88 . This channel 88 may carry signals and may be implemented using a wireless medium, wire or cable, fiber optics, or other communications medium. Some examples of a channel include a phone line, a cellular phone link, an RF link, a network interface, a local or wide area network, and other communications channels.
In this disclosure, the terms “computer program product,” “computer-readable medium” and the like may be used generally to refer to media such as, for example, memory 68 , storage device 78 , or storage unit 82 . These and other forms of computer-readable media may store one or more instructions for use by processor 64 , to cause the processor to perform specified operations. Such instructions, generally referred to as “computer program code” (which may be grouped in the form of computer programs or other groupings), when executed, enable the computing system 60 to perform functions of embodiments of the invention. Note that the code may directly cause the processor to perform specified operations, be compiled to do so, and/or be combined with other software, hardware, and/or firmware elements (e.g., libraries for performing standard functions) to do so.
In an embodiment where the elements are implemented using software, the software may be stored in a computer-readable medium and loaded into computing system 60 using, for example, removable storage drive 74 , drive 72 or communications interface 84 . The control logic (in this example, software instructions or computer program code), when executed by the processor 64 , causes the processor 64 to perform the functions of embodiments of the invention as described herein.
This disclosure is illustrative and not limiting. Further modifications will be apparent to these skilled in the art in light of this disclosure and are intended to fall within the scope of the appended claims. | In the fields of data security and system reliability and qualification, this disclosure is of a method, system and apparatus for verifying or authenticating a device to a host using a zero-knowledge based authentication technique which includes a keyed message authentication code such as an HMAC or keyed cipher function and which operates on secret information shared between the host and the device. This is useful both for security purposes and also to make sure that a device such as a computer peripheral or accessory or component is qualified to be interoperable with the host. | 7 |
This invention was made with Government support under Contract F30602-91-C-0107 awarded by Rome Laboratory, Department of the Air Force, and Contract N60921-93-C-0097, awarded by the Naval Surface Warfare Center for the Ballistic Missile Defense Organization. The Government has certain rights in this invention.
RELATED APPLICATIONS
This is a continuation-in-part of U.S. application Ser. No. 08/207,628, filed Mar. 9, 1994, which is a continuation of U.S. application Ser. No. 07/921,008, abandoned Mar. 6, 1985, filed Jul. 28, 1992, now U.S. Pat. No. 5,321,270, which is a continuation of U.S. application Ser. No. 07/721,345, filed Jul. 1, 1991, now U.S. Pat. No. 5,134,686, which is a continuation-in-part of U.S. application Ser. No. 07/419,479, filed Oct. 10, 1989, now U.S. Pat. No. 5,029,253. The disclosures of all of these related applications are herein incorporated by reference.
BACKGROUND OF THE INVENTION
1. Field of the Invention
The present invention relates to a three-dimensional memory and, more specifically, to an electron trapping based three-dimensional memory without interpage crosstalk.
2. Description of the Related Art
In order to achieve higher performance, computers are increasingly relying on parallel processing and demanding memory systems with high storage capacity and fast parallel access capability. Present memory technologies such as semiconductor memories, optical disks, magnetic disks and tapes store information across a planar surface. Due to their two-dimensional nature, these storage devices are not able to provide parallel access. As the manufacturing technology matured in recent years, the storage density of these devices (e.g., optical disks) have reached the theoretical limitation, which is proportional to 1/λ 2 .
To overcome the restrictions imposed by present two-dimensional memory devices, three-dimensional optical memories have been proposed. Since the information is stored in volume, three-dimensional optical storage devices have higher theoretical storage capacity (proportional to 1/λ 3 ) than the planar memories. In addition, three-dimensional optical memory devices have the potential for parallel access. The data is arranged in two-dimensional pages, or bit planes. An entire two-dimensional page can be written or read in a single memory access operation.
The performance of a two-photon based three-dimensional memory is limited by the fatigue of the materials. In order to suppress the fatigue, the two-photon materials need to be kept at low temperature (e.g., in dry ice).
Electron trapping materials do not suffer from the above-described fatigue problem associated with two-photon material. Indeed, optical memories employing electron trapping material have been demonstrated to be capable of more than one million writing, reading and erasing cycles. This longevity makes electron trapping materials an excellent media for implementing stacked layer three-dimensional optical memories. Accordingly, three-dimensional optical memories employing electron trapping materials have been proposed. See, e.g., U.S. Pat. No. 5,163,039, assigned to the same assignee as the present invention, the disclosure of which is herein incorporated by reference.
However, as described in greater detail below, the excitation by light of one layer in a multi-layered electron trapping memory in the writing process can cause inadvertent and undesired excitation of adjacent electron trapping layers. Of course, for proper operation of a multi-layer memory, it is critically important to be able to address individual memory layers and avoid interlayer "crosstalk" when writing data into the memory device. Previously, to overcome this "crosstalk" a checkerboard encoding and a differential detection scheme has been employed. See, e.g., X. Yang, C. Wrigley and J. Lindmayer, "Three-Dimensional Optical Memory Based on Transparent Electron Trapping Thin Films, Proc. SPIE, Vol. 1773, Photonics for Computers, Neural Networks and Memories, p. 413-422 (1992).
Although the checkerboard encoding scheme has been proven to be effective in reducing crosstalk, it is desirable to provide a system which provides a three-dimensional memory without crosstalk and which does not require special encoding and decoding schemes for proper operation.
SUMMARY OF THE INVENTION
The present invention advantageously provides a three-dimensional optical memory employing electron trapping thin film layers which is designed to avoid undesirable interlayer crosstalk, and which does not require encoding/decoding of data.
The present invention achieves this objective by providing a three-dimensional optical memory, comprising at least two thin film layers of different electron trapping material for storing and releasing information in the form of light energy, in which each of the thin film layers of electron trapping material is sandwiched between a pair of insulating layers and a pair of transparent electrodes.
The electron trapping material preferably comprises a mixture of a base material selected from the group of alkaline earth metal sulfides and mixtures thereof; a samarium dopant for establishing an electron trapping level; and a europium and/or cerium dopant for establishing an optical absorption center for writing and for providing readout luminescence. The thin film layers of different electron trapping material are deposited in a thickness on the order of microns on a substrate.
The thin film layers of electron trapping material store the information, such as digital data, in the form of an increased energy level of electrons, and release the stored information in the form of light energy of wavelengths having peaks centered about different predetermined wavelengths.
An insulating, transparent separation layer is preferably provided between adjacent transparent electrodes of neighboring thin film electron trapping layer sandwiches.
The three-dimensional optical memory of the present invention also can be provided on a transparent substrate from which information can be read and written using a system which: (i) selectively supplies voltage to the transparent electrodes to suppress the storage of information in the thin film layers of electron trapping material sandwiched therebetween; (ii) illuminates an addressed thin film layer of electron trapping material with an image comprising light energy of a first wavelength to store information in the addressed layer, while simultaneously supplying a voltage to the transparent electrodes sandwiching the addressed thin film layer to enhance the storage of information in the addressed thin film layer; (iii) illuminates the addressed thin film layer of electron trapping material with light energy of a second wavelength to release the information stored in the addressed layer, while simultaneously supplying a voltage to the transparent electrodes sandwiching the addressed thin film layer to enhance readout of information from the addressed thin film layer, the released information being emitted from the electron trapping material in the form of light energy of a third wavelength; and (iv) detects the released light energy of a third wavelength emitted by the addressed electron trapping material.
The image stored in the thin film layer of electron trapping material is preferably generated by a visible light source, a page composer and a dynamic focussing lens. An IR light source, a beam deflector and a cylindrical lens are preferably used to illuminate the thin film layer of electron trapping material with light energy of a second wavelength to release the stored image. A dynamic focussing lens and an array detector are preferably used to collect and detect the released image.
Other features and advantages of the present invention will become apparent from the following description of the invention which refers to the accompanying drawings.
BRIEF DESCRIPTION OF THE DRAWINGS
The above and other features and advantages of the present invention will become apparent when the following detailed description is read in conjunction with the accompanying drawings.
FIG. 1 shows the mechanism for light emission of electron trapping materials.
FIG. 2 shows the energy band model of electron trapping materials under an external electric field.
FIG. 3 is a graph showing the effect of an external electric field on the absorption fluorescence of a singly doped material with a fluorescence center similar to that of the electron trapping material.
FIG. 4 shows the three-dimensional optical storage system of the present invention.
FIG. 5 shows the multilayer electron trapping device of the present invention.
DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENT
In view of the importance of electron trapping materials to the present invention, a brief review of their relevant characteristics, which are more fully described in the cited papers, is appropriate.
A. Electron Trapping Materials
Electron trapping materials characteristically can emit different output photons which correlate spatially in intensity with input photons. The preferred electron trapping material of the present invention is formed of an alkaline earth metal sulfide base doped with rare earth impurities. A number of different electron trapping materials have been developed by the assignee of the present application. For example, U.S. Pat. No. 4,839,092 discloses a material formed of a strontium sulfide base doped with samarium and europium (SrS:Sm,Eu). This material outputs orange light centered at 620 nm. Similarly, U.S. Pat. No. 4,842,960 discloses a material formed of a mixed strontium sulfide/calcium sulfide base doped with samarium and europium/cerium (SrS/CaS:Sm, Eu/Ce). This material also emits orange light, but has a very high efficiency and a brighter output than the material without calcium sulfide. The writing/storing wavelength of this preferred SrS/CaS:Sm,Eu/Ce material is about 450 nm, its stimulation wavelength is near-infrared. U.S. Pat. No. 4,879,186 discloses a material formed of a calcium sulfide base doped with samarium and europium (CaS:Sm, Eu), which outputs red light centered at 650 nm.
Each of the above electron trapping materials have electron traps with depths of about 1.0 to 1.2 electron volts. Further details of the materials and the processes for making the materials are set forth in the disclosure of each of the above-referred U.S. patents, which are herein incorporated by reference.
Briefly, the mechanism for light emission of electron trapping materials can be explained as follows, using the SrS:Sm,Eu material as an example, with reference to FIG. 1. Both ground and excited states of each impurity exist within the band gap of the wide-band-gap (approximately 4.4 eV) host material. Short wavelength visible light (e.g., blue light of 488 nm) excites electrons from the ground state (valence band G) to an excited state of Eu (communication band E), from whence the electrons transfer over to Sm. The electrons remain in the ground state of Sm (trapping level T) for very long times. However, subsequent exposure to IR light (e.g. 1064 nm) excites the trapped electrons to the excited states of Sm, the electrons transfer to the excited states of Eu and return to the ground state of Eu with the emission of orange/red light. By way of the above mode of operation, the electron trapping materials can be used to store optical information in the form of trapped electrons. This has been described by J. Lindmayer, P. Goldsmith and C. Wrigley in "Electronic Optical-Storage Technology Approaches Development Phase", Laser Focus World, p. 119, November 1989.
Advantageously, electron trapping materials exhibit a large linear dynamic range of four orders of magnitude. The response time of the emission to the IR light is on the order of tens of nanoseconds.
Disadvantageously, however, as described above, the excitation by light during the writing process of one layer in a multi-layered electron trapping memory can cause inadvertent and undesired excitation of adjacent electron trapping layers. For proper operation of a multi-layer memory, it is critically important to be able to address individual memory layers and avoid interlayer "crosstalk" when writing data into the memory device.
The present inventors have designed a novel multi-layer electron trapping memory in which crosstalk is eliminated by sandwiching the electron trapping layers between transparent electrodes. When an electric field is applied across a designated electron trapping layer or layers, the electron trapping process is modified in that layer or layers by a phenomenon known as electric field induced ionization. Specifically, as shown in FIG. 2, under a sufficient external electric field, the energy band model of the electron trapping material is altered such that, instead of only tunneling to the nearby samarium atom and being trapped, the electrons excited at the Eu can tunnel to the conduction band of the host material. As shown in FIG. 3, this effect decreases the absorption fluorescence in singly doped CaS:Eu to on the order of 1% of that without the electric field.
For the doubly doped electron trapping material used in the present invention, it was initially expected that the electric field induced ionization of the (for example) Eu would result in a much reduced supply of excited electrons for the Sm to receive from the Eu and thereby reduce the resulting electron trapping. However, as shown in FIG. 2, with an applied electric field, the electrons which are caused to enter the conduction band of the host material have an easier access to the excited states of Sm atoms energetically downhill (i.e. in the opposite direction of the electric field) of each excited Eu atom than by the lateral constant-energy tunneling in the zero-field case. Consequently, the writing or electron trapping process is enhanced when an electric field is applied, due to freed (conduction band) excited electrons falling into the Sm storage sites from the host material's conduction band.
Similarly, readout of trapped electrons in the electron trapping material has been found to be enhanced by the application of an electric field across the material. In this case, stored electrons excited at Sm atoms by infrared in the plane selected for readout can enter the conduction band of the host material, cascade into downhill Eu atoms and produce readout luminescence.
The present invention takes advantage of the above-described effect of electric field ionization to eliminate crosstalk in a multi-layer electron trapping memory. Specifically, in accordance with the present invention, the concentrations of Eu and Sm disclosed in the above-referenced patents can be lowered, for example by a factor of ten, such that tunneling from Eu to Sm is made much less probable, thereby suppressing writing and readout in those layers without an applied electric field. Thus, by applying an electric field across selected layers of the multi-layer structure during the writing operation, interlayer crosstalk is advantageously eliminated in the present invention. The specific structure of the three-dimensional electron trapping memory of the present invention will now be described.
B. Three-Dimensional Optical Storage System
The electron trapping material based three-dimensional optical storage system 2 of the present invention is schematically illustrated in FIG. 4. Analog or digital data are stored in a multilayer electron trapping device 4. As shown in FIG. 5, each electron trapping thin film 6 is sandwiched between transparent insulating layers 8 (formed, for example, of SiO 2 , Al 2 O 3 , Ta 2 O 5 , diamond-like carbon films, or combinations thereof) and transparent electrode layers 10 (preferably formed of indium tin oxide (ITO)). Insulating layers 8 and electrode layers 10 are less than 1 μm in thickness, the thickness of the layer being controlled to achieve a maximum transmittance in accordance with the formula
2·n·h=(m+1/2)λ.sub.visible
where n=refractive index
h=layer thickness
n=0, 1, 2, . . .
such that each pair of electrode and insulating layers forms an antireflection film for blue and orange light (i.e. the charging light and the light output from the electron trapping material). An insulating, transparent separation layer 11 is provided between electrodes of neighboring electron trapping thin film sandwiches in device 4.
To write data into the memory, a page composer 12 is illuminated by a visible light beam, preferably blue light, and is imaged to the addressed electron trapping layer by a dynamic focusing lens (DFL) 14. The page addressing is achieved by applying suitable voltage to the electron trapping layer to be addressed.
To retrieve the stored data, a slice of IR light is guided into the addressed layer from the edge with a beam deflector 16 and a cylindrical lens 18, preferably again with the application of a suitable voltage to the electron trapping layer to be read. Since the refractive index of electron trapping materials (about 2.25) is higher than that of the insulating layer (e.g., 1.5 for SiO 2 ; 1.7 for Al 2 O 3 ), the IR light is restricted within the addressed electron trapping film and cannot leak to the other layers. The resultant emission from the addressed electron trapping film (orange light) corresponding to the stored data is collected by a second DFL, identified in FIG. 4 as DFL 15, and detected by an array detector 20.
DFLs 14 and 15 are selected to be capable of randomly accessing any one of the page planes at very high speed to ensure a high data transfer rate. Each bit in the page composer is imaged onto electron trapping thin film and then imaged exactly onto the corresponding pixel of the detector array. The data pages are preferably binary patterns or analog images with very high resolution and large space-bandwidth product to assure large capacity and high storage density.
In summary, the present invention provides a three-dimensional optical storage system based on transparent electron trapping thin films. It extends storage into the third dimension, enabling higher capacity and faster access time than existing two-dimensional memories. Since the two-dimensional data pages are stored and retrieved in parallel, the achievable data transfer rate is substantially increased over prior art memories. Thus, the three-dimensional optical storage system of the present invention can be utilized as high speed, high density, massive memory for supercomputers. In addition, its parallel access nature makes it compatible with the next generation of ultrafast parallel opto-electronic computers which combine optical interconnects with electronic processing. The crosstalk in electron trapping material based three-dimensional optical memory is advantageously overcome by the effect of electric field induced ionization.
Although the present invention has been described in relation to particular embodiments thereof, many other variations and modifications and other uses will become apparent to those skilled in the art. It is preferred, therefore, that the present invention be limited not by the specific disclosure herein, but only by the appended claims. | A three-dimensional optical memory based on stacked thin film electron trapping layers. Each thin film electron trapping layer is sandwiched between pairs of insulating layers and transparent electrodes. When an electric field is applied across the electron trapping layer via the electrodes, the electron trapping process is enhanced. In this way, electrical page addressing can be achieved for writing data to the memory. The data are read out by an IR light directed into the electron trapping film from the edge, again preferably with the application of an electric field across the addressed layer to enhance readout. The application of an electric field across an addressed layer during the writing and reading steps effectively eliminates inter-page crosstalk. | 8 |
CROSS REFERENCE TO RELATED APPLICATIONS
[0001] This patent application claims the priority of U.S. Provisional Patent Application No. 60/486,884, inventor Bruce L. Riley, filed on Jul. 10, 2003 and entitled Component Modular Foam Based System For Construction Of Concrete Structures.
FIELD OF THE INVENTION
[0002] A portion of the disclosure of this patent document contains material which is subject to copyright protection. The copyright owner has no objection to the facsimile reproduction by anyone of the patent document or the patent disclosure, as it appears in the U.S. Patent and Trademark Office patent file or records, but otherwise reserves all copyright rights whatsoever.
[0003] This invention relates to concrete structures and more particularly to a method and apparatus for constructing a concrete structure having a solid foam core, forming a water-resistant structure that is particularly amenable to applications where water is used, such as for a decorative fountain.
BACKGROUND OF THE INVENTION
[0004] Concrete structures such as buildings, outdoor barbeques, shower stalls and swimming pools are typically constructed by first assembling forms to hold the concrete in place. Armature, usually in the form of a matrix of steel rebar is then placed in the form to give the concrete added tensile strength, different sections of armature may need to be spliced together with steel wire. Concrete is then poured over the armature, immersing the armature. Alternatively, after the armature is completed, a mesh of steel, burlap or nylon netting may be placed over the armature and tied to it. This mesh provides a surface to hold the concrete in place over the surface of the structure. A first structural layer of concrete may be poured over the mesh and allowed to harden.
[0005] For situations requiring waterproofing, an elastomeric waterproof coating may then be applied to the structural concrete coat. A final, textured concrete coat might be applied to the structural coat and textured and colored to give a desired appearance.
[0006] A solid concrete wall may be constructed in a similar fashion but sheet forms such as plywood must typically be used to hold the concrete in place while it dries and hardens. An alternative to solid concrete construction, where the strength of solid rebar armature-reinforced concrete is not required, is using a wood and mortar or stucco construction. A stucco wall, for example, is usually built by constructing a wood frame, covering the wood frame with a waterproof membrane such as tar paper, covering the tar paper with a mesh and troweling or spraying on one or more layers of mortar or concrete over the mesh. The wall is structurally supported by the wood frame and the concrete layer is added to provide the strength and imperviousness of masonry.
[0007] The construction of naturalistic artificial rock structures, such as fountains surrounding a swimming pool requires a more specialized construction. There has been a trend in swimming pool design to incorporate naturalistic elements into the surrounding deck, such as waterfalls and rocks, such that the pool looks like a natural mountain pond or tropical grotto.
[0008] A common swimming pool waterfall construction technique employs concrete footings reinforced with steel rebar. The footings are first anchored to the ground and then an armature or steel skeleton in the desired general shape of the naturalistic artificial rock structure is anchored to the footings. This process is laborious and expensive, the armature is laboriously formed by bending the steel rebar into the basic shape of the desired finished structures. When the armature is shaped to form a resulting enclosed structure, framework such as wood bracing and steel-reinforced concrete support columns must frequently be used in the internal area to reinforce the artificial rock structure and ensure structural integrity.
[0009] There are other methods for building naturalistic waterfalls and other artificial rock structures but they too have drawbacks. Natural rock itself can simply be cemented together to make the structures, but natural rock is heavy and difficult to move; it is expensive to buy and to transport, it is difficult to work with. Natural rock it also requires a high degree of skill to ensure that a structurally sound artificial rock structure is built, and, natural rock tends to be difficult to seal against water. Natural rock also tends to leak water when used alone to build a waterfall or basin.
[0010] An alternative to constructing these artificial rock structures is to use preformed plastic or urethane waterfalls and rocks and simply affix around the pool. These structures tend to be unconvincing though and fake in appearance. Moreover, these preformed plastic and urethane structures are also flimsy and structurally weak and tend to fade and crack under the stress of sun or from people climbing on them. These fake rocks are just for decoration they usually do not incorporate steel-reinforced concrete.
[0011] The foregoing methods of constructing concrete and concrete-covered structures require a high degree of skill to shape the finished product, to place the forms correctly and particularly to ensure the integrity of the waterproofing of the concrete. These methods are also wasteful because the forms must be discarded or stored after use, and a given shape must be repeatedly reconstructed from the same forms when a similar construction is subsequently undertaken. The present methods are also labor-intensive, time-consuming because they require that forms to be set, the armature and mesh to be placed and, after the concrete is poured, the removal of the forms. Finally, the above methods are difficult to design by engineers and difficult to inspect by building inspectors, because they are frequently custom jobs.
[0012] An improved method for producing easily constructed water-resistant structures for such applications is taught in U.S. Pat. No. 6,581,349, Riley, titled Method And Manufacture For Constructing Watertight Concrete Structures. In that patent a method is taught of using rigid plastic shells faced with armature such as rebar. The shells are wired to each other and covered with a layer of cementatious material. Castings are usually added to the cement-covered shell structure and bonded with additional concrete. Castings are pre-cast impressions made from the image of natural rock or a mold made to look like pre-cast rock. These castings may be hollow formed sheets and are usually made from concrete or fiber-embedded concrete.
[0013] The Riley '349 patent presents a much easier method for constructing such naturalistic fountains but requires some degree of skill and further labor to construct and complete the structure, such as a fountain.
[0014] What is needed then is a less labor-intensive method that optimally will be lighter to reduce transportation costs for building naturalistic structures or waterproofed structures.
SUMMARY OF THE INVENTION
[0015] A more economical construction method requiring less skill and time to construct a concrete structure has been developed. A concrete structure such as a fountain or more complicated structure may be constructed by providing one or more pieces of rigid foam to make a structural block. The structural foam block is anchored to a foundation pad, typically a concrete foundation pad. The block may be attached to the foundation pad with cement. The block may further have one or more anchoring holes extending through the foam block that can be filled with concrete, cement or the like to further anchor the block to the pad.
[0016] The structural foam block is provided is sized in the general shape of the desired structure. After it is affixed to the foundation pad it is partially or fully covered with one or more castings, made from fiber-reinforced/fiber-embedded concrete for example, which are affixed to the structural foam block with a closed-cell liquid foam that expands and hardens as it cures. The castings may further be more securely attached to the structural foam block by affixing wiring to the castings and also placing the wires in the anchoring holes to be covered by the concrete.
[0017] In this way the castings will partially or fully cover the structural foam block. The castings may be further affixed to the concrete structure by filling any remaining voids between the castings and the structural foam block with a cementations material.
[0018] In one embodiment the castings are formed to appear like natural rock. The invention is particularly useful with respect to making outdoor structures, where it may be desirous to have the structure appear as natural rock. The castings may be prepared by being pre-cast from an impression made from a natural rock, or even from a mold artistically made to look like natural rock. Using a waterproof liquid foam is advisable in this environment.
[0019] There are a wide variety of liquid foams that are suitable to affixing the components of the invention together. There are urethane foams, latex foams, phenolic foams and other organic foams, to name a few. Gernerally, the foam is a liquid or foamy slurry that is sprayed on and expands and hardens as it cures, bonding the casting to the structural foam block. A liquid foam that cures to produce a waterproof barrier will provide additional waterproofing.
[0020] If the intended concrete structure is be significantly weight-bearing, rebar armature can be added to secure support the castings and/or secure the structure to the foundation.
[0021] The invention may be particularly suitable for building an outdoor structure, such as outdoor water fountain for a swimming pool for example. A water pump can be incorporated near or within the concrete structure, the water pump moves water through a riser pipe to a higher point on structure, an upper casting, so that the water will then fall into a basin such as a pond or swimming pool, to be then be recirculated by the pump.
[0022] In this respect, before more fully explaining at least one embodiment of the invention in detail it is to be understood that the invention is not limited in its application to the details of construction and to the arrangements of the components set forth in the following description or illustrated in the drawings. The invention is capable of other embodiments and of being practiced and carried out in various ways. 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. As such, those skilled in the art will appreciate that the conception, upon which this disclosure is based, may readily be utilized as a basis for the designing of other structures, methods and systems for carrying out the several purposes of the present invention. It is important, therefore, that the claims be regarded as including such equivalent constructions insofar as they do not depart from the spirit and scope of the present invention.
[0023] Accordingly, although exemplary embodiments of the invention have been shown and described, it is to be understood that all the terms used herein are descriptive rather than limiting, and that many changes, modifications, and substitutions may be made by one having ordinary skill in the art without departing from the spirit and scope of the invention. Further objects and advantages of the invention will become apparent to one skilled in the art by reading and understanding the following detailed description and the drawings to which it refers.
BRIEF DESCRIPTION OF THE DRAWINGS
[0024] FIGS. 1A and 1B are top and side views of the rigid foam used as a core for the present structure.
[0025] FIG. 2 is a perspective view of a casting of the present invention.
[0026] FIG. 3 is a side cutaway view of an embodiment of the present invention.
[0027] FIG. 4 is a photograph of a side view of the present invention under construction.
[0028] FIGS. 5A and 5B are photographs of up an upper view of FIG. 4 .
[0029] FIG. 6 is a photograph of up a rear upper view of FIG. 4 .
[0030] FIG. 7 is a photograph of up an alternative embodiment of the present invention under construction.
[0031] FIG. 8 is a cutaway schematic view of the side of a fountain built as an embodiment of the present invention.
DESCRIPTION OF THE INVENTION
[0032] The following description, and the figures to which it refers, are provided for the purpose of describing examples and specific embodiments of the invention only and are not intended to exhaustively describe all possible examples and embodiments of the invention.
[0033] Referring now to FIGS. 1A and 1B a concrete structure such as a fountain is formed by providing a rigid foam block 21 anchored to a concrete foundation pad 23 . An example of such a foam block is one made of an extruded polystyrene such as Styrofoam®, made by the Dow chemical company of Midland, Mich. Another closed cell extruded or molded/expanded polystyrene or polyethylene or other structural foam product with generally equivalent properties may be used as well. Styrofoam® and its equivalents, hereafter referred to as styrofoam, provides excellent water resistance, high insulation value and superior compressive strength.
[0034] In this embodiment the single rigid block of foam 21 is used and the anchoring is achieved by using a styrofoam block forming a void, an anchoring hole 25 , passing through the styrofoam block 21 . The styrofoam block 21 is carved or otherwise shaped to the desired general shape of the completed structure. The styrofoam block 21 is then placed on the concrete foundation pad 23 . An initial layer of concrete may be used to cement the styrofoam block 21 to the foundation pad 23 .
[0035] Referring now to FIG. 2 , foam-filled castings 27 of a variety of shapes are provided. As noted above castings are pre-cast impressions made from the a impression mold of natural rock or a mold artistically made to look like rock. Castings are typically made using a latex mold which was in turn made from an impression of natural rock. The castings are optimally made from fiber-reinforced/fiber-embedded concrete (FRC) and filled with closed-cell foam 29 . The castings are preferably colored and treated for water resistance.
[0036] The foam in the castings is usually applied as a liquid foam and allowed to harden. Liquid foam insulation can be applied from small spray containers as a liquid or in larger quantities as a pressure sprayed (foamed-in-place) product. There are also liquid foam materials that are poured from a container. These types of foam expand and harden as the chemical mixture cures and conform to the shape of the cavity to fill and seal it thoroughly. These are generally urethane foams but latex, phenolic, and organic based foams are available too.
[0037] FIG. 3 is a schematic of the invention with parts in their relative configuration. FIGS. 4-7 are photographs of the component parts of an actual construction of the invention. FIG. 4 is a side view of the construction of a water fountain structure. The upper casting 31 is lined with the foam 29 . FIG. 5 details the anchor hole 25 centrally located in the styrofoam block 21 .
[0038] According to an embodiment of the present invention the styrofoam block 21 is placed on the concrete foundation pad 23 . Foam filled castings 27 are affixed to the top 31 and sides of the structure. Wiring 33 may be used to affix the foam castings 27 to the styrofoam block 21 , as shown in FIG. 6 . In one embodiment one or more castings are wired into through the anchor hole 25 as well to anchor the castings 27 to the structure and give them durability. Concrete is then poured through the anchor hole and over the top of the styrofoam block 21 , thereby anchoring the styrofoam block 21 to the concrete pad 23 . The upper casting 31 is then placed over the styrofoam block 21 and the seams between the castings 27 are cemented together with cement 28 .
[0039] FIG. 7 shows the same construction but incorporating rebar armature 35 . Although this may be structurally desirable in some situations, one of the advantages of this method of construction is that the complications of rebar can be avoided. Typically the use of rebar in construction requires that the structure be engineered, then inspected and approved by a building inspector in several steps that require a pause in construction.
[0040] In contrast, in the present invention a structurally strong and fully waterproof concrete structure can be assembled with a relatively low level of skill in a matter of hours, and without the need for rebar. FIG. 8 is a cutaway schematic view of the side of a fountain built as an embodiment of the present invention. The fountain includes a water pump 39 and a riser pipe 41 that through which water 42 is pumped over the upper casting 31 into a basin 43 , such as a swimming pool.
[0041] It will be appreciated that the invention has been described hereabove with reference to certain examples or embodiments as shown in the drawings. Various additions, deletions, changes and alterations may be made to the above-described embodiments and examples without departing from the intended spirit and scope of this invention. Accordingly, it is intended that all such additions, deletions, changes and alterations be included within the scope of the following claims. Further, the purpose of the foregoing abstract is to enable the U.S. Patent and Trademark Office and the public generally, and especially the scientists, engineers and practitioners in the art who are not familiar with patent or legal terms or phraseology, to determine quickly from a cursory inspection the nature and essence of the technical disclosure of the application. The abstract is neither intended to define the invention of the application, which is measured by the claims, nor is it intended to be limiting as to the scope of the invention in any way. | A method and structure for constructing a waterproof concrete structure using a central core of rigid foam attached to exterior castings, cemented together and anchored to a foundation. | 4 |
This is a division, of application Ser. No. 07/617,008, filed Nov. 21, 1990 now U.S. Pat. No. 5,183,245.
BACKGROUND OF THE INVENTION
1. Field of the Invention
The present invention relates to semi-conductor wafer handling equipment and, more particularly, to an improved clip and method for securing a semi-conductor wafer to the surface of a support pedestal.
2. History of the Prior Art
In the manufacture of semi-conductor devices, such as integrated circuits, a plurality of devices are generally formed on a single circular wafer of silicon material. The wafer is typically circular in shape and on the order of 6 inches in diameter. The wafers are put through a number of sequential processing steps, including coating them with photo-resists, exposing them to the optical patterns formed on photo masks, and exposing them to both liquid and gaseous treating environments.
The processing of a silicon wafer containing a plurality of semi-conductor devices requires a high degree of cleanliness and sterility in the environment in order to produce acceptable devices. The ability of a semi-conductor device to perform satisfactorily from both an electrical and mechanical standpoint depends upon the nature and quality of the materials forming the various layers of the device. The chemical composition of these materials must be extremely pure. The introduction of any foreign matter into the environment where the wafers are being processed results in a decrease in the "yield" of the wafer. The yield is the number of devices that can pass the required electrical tests of the device after the processing has been completed. This is usually expressed as a fraction of the total number of devices processed on the wafer that did pass the required tests. Thus, the higher the purity of the processing environment and processing techniques used in manufacturing the semi-conductor devices, the greater the yield and hence the greater the financial return to the manufacturer.
Semi-conductor wafers are conventionally exposed to liquid and gaseous treating environments by positioning them within a sealed chamber conventionally referred to as an "etcher." All outside contaminants are excluded from the environment within the etcher which is used to simultaneously expose a plurality of wafers being processed to various gases and/or liquids during the wafer processing operation. One type of semi-conductor wafer processing etcher includes, within the sealed chamber, a hexagonal column referred to as a "hexode". The hexode has a plurality of vertically extending planar sidewalls, and attached to each sidewall are a plurality of support "pedestals." A semi-conductor wafer being processed is attached to such a pedestal and held there by means of wafer retaining clips mounted therearound.
The interior of a typical hexode contains cooling coils for removing heat from the back side of the highly conductive support pedestals and, hence, from the semi-conductor wafers which they support. The back side of each wafer is held flush against the flat upper surface of a pedestal to provide a good heat transfer engagement therebetween in order to cool the wafer and keep the temperature gradients across its surface uniform during processing. It is important that the many different semi-conductor devices being simultaneously formed on the front surface of the wafer each be exposed to the same temperatures and chemicals for identical periods of time in order to ensure uniformity of electrical operating characteristics in each device.
At the end of a processing cycle, the sealed chamber of the etcher is opened and a robotic manipulator is used to depress the latches on the wafer retaining clips and grip the silicon wafers by their edges to remove them from the mounting surface of the pedestals and transfer them to their next processing operation.
To guard against the introduction of impurities into the silicon wafer processing environment, the equipment operators preferably wear caps, gowns, and surgically sterile rubber gloves when they are handling any of the equipment associated with the wafers. In addition, the operators also frequently change gloves, sometimes three to four times per day, to reduce the amount of contaminants which might accumulate thereon and affect the wafer processing environment. Despite all of these precautions, it has been found that the interior of the etchers must be cleaned periodically to remove as many potential future contaminants of the wafers as possible. In addition, the equipment within the interior of the etchers is periodically replaced completely because of an accumulation of potential contaminants which invariably come in contact with the wafers and reduce their yield. Because of the expense connected with both cleaning an etcher as well as periodically replacing the interior parts of an etcher, it is highly desirable to attempt to maximize the length of time in which an etcher can operate without either a cleaning or a replacement of its interior parts. For this reason, it is desirable to provide equipment with which the wafers come in contact of the type minimizing the tendency toward wafer contaminant pollution.
It has been found that one of the means by which contaminants are transferred to the wafers is the wafer retaining clips which are disposed around the periphery of the wafer pedestals mounted on the hexode. Even though these clips are relatively clean and simple in design, it has been found that prior art clip designs tend to accumulate contaminating materials. Such contaminants are accumulated during the processing cycle of one particular batch of wafers and then passed on to a second batch of wafers when they are introduced into the etcher. It has also been found that the specific geometric configuration of the pedestal clips has a relationship to the number of contaminants it collects and in the way in which those contaminants may be passed on to other batches of semi-conductor wafers.
It would, thus, be desirable to provide an improved pedestal retention clip for securing semi-conductor wafers to pedestal surfaces which minimizes the contamination of wafers. The clips should also be quickly and easily detachable from the edge of the semi-conductor wafer and should be easily actuatable by a robotic tool.
SUMMARY OF THE INVENTION
The present invention pertains to a pedestal clip for securing a semi-conductor wafer to a processing pedestal. In one aspect, the invention includes a pedestal clip constructed to minimize the contact between the clip and the edge of the wafer and to minimize the tendency of the clip to contaminate the wafer with foreign particles. The clip includes a base member adapted for securement to the pedestal and an upstanding body portion extending from the base member toward the treatment surface of the pedestal to which the wafer is to be secured. A clip head is mounted to the body portion for resilient movement with respect thereto. The clip head includes a pair of spaced apart, forwardly extending tines adapted to engage outer edges of a semi-conductor wafer supported upon the treatment surface of the processing pedestal. A clip tail is oppositely disposed from the tines, the tail affording resilient movement of the tines toward and away from the edges of the pedestal treatment surface to enable the installation and removal of the wafer therefrom.
In another aspect of the invention, the tines of the clip described above are separated from one another by a space equal to at least twice the width of one of the tines. The lower surfaces of each of the edges also forms an angle with respect to the treatment surface of the pedestal on the order of 45 degrees. The resilient means for securing the head portion to the body portion also comprises a flexible metal strip.
In yet another aspect, the invention includes an improved method for securing a semi-conductor wafer to the surface of a wafer processing pedestal of the type wherein a clip head is flexibly mounted relative to the pedestal for facilitating the installation and removal of the wafer therefrom. The improvement comprising the steps of forming the clip head with first and second tines spaced one from the other and adapted to engage outer edges of the wafer. An angulated surface is formed beneath each tine and the clip head is positioned to present the angulated surface toward the pedestal. A rear portion of the clip head is then depressed to flex the resilient securing means and allow movement of the head with respect to the pedestal for the securement and removal of the wafer relative thereto.
BRIEF DESCRIPTION OF THE DRAWINGS
For an understanding of the present invention and for further objects and advantages thereof, reference may now be had to the following description taken in conjunction with accompanying drawings, in which:
FIG. 1 is a partially cut-away perspective view of a semi-conductor wafer etcher with the cover having been removed therefrom;
FIG. 2A is a plan view of one planar sidewall of the hexode located within the etcher of FIG. 1 showing the pedestals mounted thereon;
FIG. 2B is a cross-section view of the hexode wall and pedestals mounted thereon taken about the lines 2B--2B of FIG. 2A;
FIG. 3 is a top-plan view of a single pedestal having four pedestal clips constructed in accordance with the teachings of the present invention disposed around the periphery thereof;
FIG. 4 is a perspective view of a pedestal clip constructed in accordance with the teachings of the present invention;
FIG. 5 is a vertical cross-section view of the pedestal clip shown in FIG. 4;
FIG. 6 is a perspective view of a prior art pedestal clip;
FIG. 7 is a contamination graph representing wafer contamination utilizing prior art pedestal clips; and
FIG. 8 is a contamination graph representing wafer contamination utilizing the pedestal clips of the present invention.
DESCRIPTION OF THE PREFERRED EMBODIMENT
Referring to FIG. 1, there is shown a partially cut-away perspective view of a silicon wafer etcher 10 which includes a circular bottom 11 through which is formed a plurality of openings 12 and 13 for the ingress and egress of fluids along with distribution piping 14 extending up into the etcher for similar purposes. The etcher includes generally cylindrical sidewalls 15 within which is formed a transparent inspection port 16 so that an operator can view the interior. The sidewalls 15 include an upper sealing edge 17 to which is sealingly fitted a cover (not shown) for enclosing the interior of the etcher.
Mounted to the bottom 11 of the etcher 10 and extending in an axial direction therein is a hexode 18 having 6 vertically extending planar sides 21-26. Upon each of the sides 21-26 is mounted a plurality of semi-conductor wafer supporting pedestals 31, 32, and 33. Pedestals are only illustrated on sides 21, 25 and 26 in FIG. 1 for purposes of clarity, but it should be understood that each of the other sides 22, 23 and 24 also include three pedestals 31-33 mounted thereon. A semi-conductor wafer can be removably mounted onto each of the pedestals 31-33 for processing within the sealed environment of the etcher 10. For this purpose, each pedestal includes a plurality of clips 34-37 for removably securing a wafer to the flat, circular mounting surface of the pedestal.
Referring next to FIG. 2A, there is shown a plan view of a sidewall 21 of the hexode 18 and the pedestals 31-33 mounted thereon. Each pedestal is generally circular in shape and includes wafer retaining clips 34-37 mounted thereto for removably securing a semi-conductor wafer to the flat mounting surface 40 of the pedestal. The pedestal 31 is itself made from a highly thermally conductive metal such as an aluminum alloy. The mounting surface 40 of the pedestal 31 is covered with a smooth thermally conductive elastomeric material 41 for receiving the rear surface of the semi-conductor wafer thereagainst. A plurality of holes 42-44 are formed through both the elastomeric material 41 as well as through the solid body 45 of the pedestal 31 for purposes of mounting.
Referring next to FIG. 2B there is shown a cross-section view through side 21 of the hexode 18 and the pedestals 31-33 taken about the line 2B--2B of FIG. 2A. As can be seen in the cross-section view of FIG. 2B, the solid body 45 of each pedestal 31-33 comprises a relatively solid single piece of highly conductive metal which conducts heat from the front, or mounting surface 40, side of the pedestal to the interior of the hexode 18 with which the rear side 46 of the pedestal 31 is in contact. The solid body 45 increases the rate of thermal conductivity through the pedestals 31-33 and provides a uniform distribution of temperature over the entire mounting surface 40 of the pedestals. Only one silicon wafer 50 is shown on the metal pedestal 31 for illustration. The other pedestals 32 and 33 are shown unoccupied for purposes of clarity.
Referring next to FIG. 3, there is shown a top plan view of a pedestal 31 including a plurality of pedestal clips 34-37 mounted thereon. As shown, each pedestal is circular and includes a solid body 45 of highly conductive material with a flat mounting surface 40. The mounting surface 40 is covered with a layer of elastomeric material 41, which is also highly conductive, facilitating the close, thermally mounting of the wafer thereon. A semi-conductor wafer 50 is shown positioned flush against the elastomeric covering 41 of the mounting surface 40 of the pedestal 31. As can be seen, each of the clips 34-37 of this figure includes a pair of tines 73 and 74 which overlay and secure the outer edges of the semi-conductor wafer 50 to the surface of the pedestal.
Referring next to FIG. 4, there is shown a perspective view of a pedestal clip 61 constructed in accordance with the teachings of the present invention. Each clip 61 is formed of Lexan and adapted for securement to a pedestal and includes a base 59 constructed with a pair of outwardly extending mounting flanges 62 and 63 on opposite sides thereof. The flanges 62 and 63 each include a mounting hole 64 and 65, respectively, for securing the pedestal clip to the underside of the pedestal. Extending upwardly from the base 59 is a front mounting column 66 which includes a bifurcated upper end formed by upstanding posts 68 and 69 separated by recess 67. A securement head 71 has a bifurcated front securement dog 72 including first and second securement tines 73 and 74 separated by an open area 75 therebetween. Tines 73 and 74 are constructed with a relatively narrow frontwardly extending linear edges 73A and 74A, respectively. The rear portion of the securement head 71 includes a depression tab 76 which is adapted for downward engagement by a tool. Depression of tab 76 releases the clip 61 from securement of a wafer positioned on a pedestal. The securement head 71 is mounted to the pedestal column 66 by means of a flexible metal spring 78 to which the securement head 71 is attached by means of a pair of screws 79 and 80. The lower rear surface of the metal spring 78 is engaged by a mounting member 81 which grips the lower edge of said spring between the member 81 and the front surface of the mounting column 66. The head 71 is thus flexibly secured to the mounting column 66 in a position for engaging a wafer, and for moving both toward and away from said wafer. The mounting member 81 is secured to the mounting column 66 of the clip 61 by means of a screw 82 shown in the cross-section view of FIG. 5.
It should be clear from observation of the prior art pedestal clip 90 of FIG. 6 that it is similar to the pedestal clip 61 of the present invention. There are, however, certain significant differences between these clips. For example, the securement head 91 of the prior art clip 90 includes a continuous, linear surface across its entire frontal wafer engaging position. The surface comprises a singular, frontwardly extending linear edge 92. The clip 61 of the present invention, in contrast, includes two separate edges 83 and 84 separated by an open area 75 which is approximately as wide as twice the width of each of the edges 83 and 84. In addition, the underlying wafer engagement surface 93 extending beneath the edge 92 of the prior art clip of FIG. 6 is deeper, thereby presenting more surface area toward the wafer edge for engagement therewith. In the present embodiment the angle to the horizontal surface of the wafer to be secured (not shown in FIG. 6) is on the order of 45 degrees, and because of the length of the wafer engagement surface 93, the upper beveled edge 92 of the prior art clip is wider than the edges 73 and 74 of the clip 61 of the present invention.
From product testing, it has been shown that the pedestal retaining clip of the present invention has produced a substantial reduction in the level of contaminants found on wafers processed on pedestals fitted with that clip. While there is still no exact understanding of all of the reasons why this has occurred, some of the reasons include the fact that only two relatively short lengths of edge surfaces 83 and 84 of the pedestal clip 61 actually engage the upper edges of the silicon wafer secured thereunder. The open area 75 between the surfaces 83 and 84 presents a substantially smaller surface area upon which contaminants may collect and subsequently be passed to other wafers. In addition, the edges 83 and 84 of the pedestal clip 61 present a longer, inclined surface area to the upper surface of the silicon wafer 50 (as shown in FIG. 5) which facilitates engagement of said wafer.
Referring now to FIGS. 7 and 8, there is shown a series of contamination graphs which represent the number of particles and impurities found in wafers manufactured by particular etchers over a select period of time. In FIG. 7 it is shown that over a period of usage of approximately two months, the particle trends (contamination) on silicon wafers processed in a particular etcher with the prior art clip of FIG. 6 varied significantly. On certain occasions, the contamination was in excess of 300 particles.
FIG. 8 is a contamination graph for the same etcher as shown in FIG. 7 over a comparable period of time after the clips 61 of the present invention had been substituted for the prior art clips 90. The graph illustrates the substantially decreased rate of contaminants over a substantially longer period of time of 510 runs compared to 350 runs with the prior art clip. It should also be noted that even after substantial usage, none of the particle counts of contaminants was in excess of 300 with the clip 61 of the present invention.
Referring now to FIGS. 3 and 5 in combination, the pedestal clip 61 of the present invention functions to secure a semi-conductor wafer 50 to the upper surface of a pedestal 31 by the spring biased, resilient engagement of its bifurcated, transversely extending edges 83 and 84 against the outer peripheral edges 50A of a semi-conductor wafer 50. In order to install the wafer onto the surface of the pedestal, a robotic actuator (not shown) is used to engage and simultaneously depress the tab portion 76 of each of the four pedestal clips 34, 35, 36 and 37 shown in FIG. 3. Depressing tabs 76 provides clearance and allows the robotic manipulator to place the semi-conductor wafer 50 directly against the mounting surface 40 of the pedestal. Once the wafer 50 is in position on the pedestal 31, the robotic manipulator releases the engaged tab portions 76 of the clips 34-37 to permit their forwardly extending edges 83 and 84 to engage the outer peripheral edge 50A of the wafer 50. Thereafter the clips hold the wafer 50 in position upon the pedestal 31 while the wafers 50 are being processed within the etcher. Upon completion of the processing cycles, the robotic manipulator again depresses the tab portions 76 of the clips 34-37 and allows the manipulator to remove the wafer from the surface of the pedestal for transportation to a subsequent processing operation.
As shown in FIGS. 3 and 5, the forwardly extending edges 83 and 84 of the pedestal clip of the present invention engage the outer peripheral edge of the wafer 50 in a restricted area of contact so as to limit the exposure of the surface of the wafer to contamination by particles collected upon the clip. Moreover, the open area 75 between the edges 83 and 84 provides a reduced surface area of contact between the clip and the wafer and thus reduces the amount of exposure of the wafer clip to surface areas which may carry contaminants. The improved pedestal clip of the present invention thus provides a functional and useful clip for efficiently and reliably securing semi-conductor wafers to the upper surface of a pedestal for processing. It has been shown that the use of the pedestal clip of the present invention on pedestals substantially increases the yield of the semi-conductor wafers secured to the pedestal and thus provides a number of distinct advantages over prior art pedestal clips.
It is thus believed that the operation and construction of the present invention will be apparent by the foregoing description. While the method and apparatus shown or described has been characterized as being preferred, it will be obvious that various changes and modifications may be made therein without departing from the spirit and scope of the invention as defined in the following claims. | A clip for removably securing a semi-conductor wafer to the treatment surface of a semi-conductor wafer processing pedestal. The clip is constructed with a pair of spaced apart, forwardly extending tines adapted to engage outer edges of a semi-conductor wafer supported upon the treatment surface. A clip tail is oppositely disposed from the tines and affords resilient movement of the tines toward and away from the edges of the pedestal treatment surface to enable the installation and removal of the wafer therefrom. | 7 |
CROSS-REFERENCE TO RELATED APPLICATIONS
This application claims foreign priority benefits under 35 U.S.C. §119(a)-(d) to DE 10 2011 002 636.3, filed Jan. 13, 2011, which is hereby incorporated by reference in its entirety.
TECHNICAL FIELD
The invention relates to a front end structure of a motor vehicle having radiator support frame that is movably mounted to the vehicle frame for pivoting movement during a crash or impact.
BACKGROUND
It is known to design the front end structure of motor vehicles (sometimes referred to as a front module) so that, in the event of a collision, energy is absorbed in a targeted or controlled manner. Ideally, this will result in the protection of both the vehicle occupants and of pedestrians who come into contact with the vehicle, in particular at relatively low vehicle speeds.
In particular, it is known to mount the radiator of the vehicle to supporting structure in a manner that, under certain crash conditions, allows the radiator to move relative to (or “break away” from) surrounding structure with the aim of absorbing crash energy.
SUMMARY
In a first disclosed embodiment, a front-end structure for a motor vehicle comprises left and a right deformation members (such as crush cans, for example) mounted forward of a front frame structure, and supporting a generally transverse bumper beam. A radiator frame is disposed forward of the frame structure and behind the bumper beam and is mounted to the frame structure by a left pair of swing arms and a right pair of swing arms. The arms making up each pair are disposed in an over-under arrangement relative to one another, and each swing arm is connected to the radiator frame at a forward pivot axis and is connected to the frame structure at a rear pivot axis. The four pivot axes are substantially parallel to one another and substantially transverse to the vehicle, such that in a frontal impact that deforms the deformation members sufficiently to urge the bumper beam rearward against the radiator frame, the radiator frame pivots about the swing arms. The radiator and radiator frame are thus able to move upwardly and to the rear.
In another embodiment, a motor vehicle comprises a forward frame structure, a bumper beam disposed forward of and connected to the frame structure, and a radiator frame disposed forward of the frame structure and behind the bumper beam. First and second swing arms are connected to the radiator frame at respective first and second forward pivot axes and are connected to the frame structure at respective first and second rear pivot axes. The four pivot axes are substantially parallel to one another and substantially transverse to the vehicle, such that a frontal impact urging the bumper beam rearward against the radiator frame causes the radiator frame to pivot about the swing arms.
BRIEF DESCRIPTION OF THE DRAWINGS
The invention is shown by way of example in the drawings and described hereinafter in detail with reference to the drawings, in which:
FIG. 1 shows in a schematic view the side view of an exemplary embodiment of the front module in the non-deformed state,
FIG. 2 shows the same side view as FIG. 1 after an impact, the deformation element being deformed and the radiator frame being displaced with the radiator,
FIG. 3 shows a schematic view of an exemplary embodiment of the four-bar linkage formed by the swing arms,
FIG. 4 shows a further exemplary embodiment for forming the four-bar linkage,
FIG. 5 shows a further exemplary embodiment of the four-bar linkage,
FIG. 6 shows a section through a practical embodiment of the front module in the non-deformed state,
FIG. 7 shows the same section of the front module as in FIG. 6 but in the deformed state,
FIG. 8A shows an embodiment wherein rear pivot axes to the swing arms are provided by plastically deformable joints, and
FIG. 8B shows a view similar to that of FIG. 8A , but in the deformed state.
DETAILED DESCRIPTION
As seen in FIG. 1 , the front-end structure of a vehicle consists of a front bumper beam 1 mounted forward of and connected to a vehicle frame structure 3 . In the embodiment depicted, the forward-most portion of frame structure 3 , adjacent to bumper beam 1 , takes the form of a deformation element 2 , which is a component designed to yield under crash loads applied to bumper beam 1 in order to absorb energy and thereby reduce the crash pulse transmitted to occupants of the vehicle. In the automotive structures field, deformation element 2 may also commonly be referred to as a “crush can.”
It is to be understood that while the side views presented here only depict one deformation element 2 , in a typical vehicle there are at least two deformation elements located adjacent the outboard sides of the vehicle frame structure to support bumper beam 1 adjacent its left and right ends. In such installations, it is common for the deformation elements 2 to be located immediately forward of longitudinally extending vehicle frame rails.
The terms “frame” and “frame structure” as used herein is meant to refer to any one or more of the major load-bearing elements of a vehicle, regardless of whether the vehicle is an example of body-on-frame, uni-body, or any other form of vehicle construction.
The front-end structure or module further includes a radiator frame 4 substantially centrally located relative to the vehicle, between left and right deformation elements 2 . Radiator frame 4 supports a radiator 5 .
The radiator frame 4 may be configured to be curved in the direction of the front face of the vehicle, and as the convex bulged portion is able to be pushed in, provides an additional element for absorbing the impact energy.
A lower frame part 6 is shown configured as a cross-member and may be arranged in the lower region of the front-end module.
The radiator frame 4 is supported by upper and lower swing arms 7 , 8 which are articulated on both sides of the front module. Rear ends of swing arms 7 , 8 may be connected to a retaining element 9 that is, in turn, connected fixedly to the frame structure 3 . Forward ends of swing arms 7 , 8 are connected to radiator frame 4 .
The rear and forward pivot axes 10 , 11 of the upper swing arm 7 and the rear and forward pivot axes 12 , 13 of the lower swing arm 8 are preferably arranged parallel to one another and substantially horizontally, and thus form a four-bar linkage.
As is revealed from FIG. 1 , the four-bar linkage is designed so that the swing arms 7 and 8 are arranged to be inclined upward and forwardly, in the direction of travel of the vehicle. That is, forward pivot axes 11 , 13 are positioned higher than their respective rear pivot axes 10 , 12 . This has the effect that, as illustrated in FIG. 2 , when bumper beam 1 is urged rearward into contact with radiator frame 4 and/or radiator 5 , radiator frame 4 along with radiator 5 may be pivoted upward and to the rear.
In the case of an impact, the bumper beam 1 initially comes to bear against the radiator frame 4 after initial energy-absorbing deformation of the deformation element 2 . With continued energy-absorbing deformation of the deformation element 2 and/or multiple deformation elements, radiator frame 4 is moved to the rear and upward by pivoting of the swing arms 7 and 8 .
The sequence of movement of the radiator frame 4 is oriented substantially according to the configuration of the four-bar linkage, which may be varied in any manner by altering the length of the swing arms 7 and 8 and the arrangement of the pivot axes 10 , 11 , 12 , 13 .
In FIGS. 3 to 5 , three possible alternative embodiments are shown in schematic form.
In all three embodiments, the rear axes 10 , 12 of the swing arms 7 , 8 connected to the retaining element 9 are disposed in an over-under arrangement a distance above/below one another in a substantially vertical plane.
Proceeding from this structure, in the exemplary embodiment of FIG. 3 , the swing arms 7 and 8 are configured to be of equal length and arranged parallel to one another. In such a construction, in the event of an impact, the radiator frame with the radiator is pivoted to the rear and upward and maintains an upright (not tilted) position.
As the bumper beam 1 moves rearward (as permitted by deformation of the deformation element or elements 2 ) and urges the radiator frame 4 rearward, the forward axes 11 , 13 of the swing arms 7 , 8 move along circular paths 14 , 15 of the same size, in each case about the respective rear axes 10 , 12 , from the position 11 a , 13 a into the position 11 b , 13 b . In the movement sequence produced thereby, the radiator frame 4 is raised, maintaining a generally vertical orientation, and at the same time moved to the rear in the direction of a passenger compartment (not shown) of the vehicle.
In the embodiment shown in FIG. 4 , the upper swing arm 7 is configured to be longer than the lower swing arm 8 so that the forward axis 11 of the upper swing arm 7 moves on a circular path 14 of larger radius than the path 15 tracked by the forward axis 13 of the lower swing arm 8 .
The configuration of the four-bar linkage shown in FIG. 4 not only causes the radiator frame 4 to be raised and moved to the rear but at the same time to perform a tilting movement in which the upper end of the radiator frame 4 is tipper farther to the rear than the lower end.
Such a construction may be advantageous if the radiator frame 4 with the radiator 5 , taking into account the fittings of the engine compartment, is intended to be tilted over an obstruction, for example the engine block (not shown).
In the embodiment shown in FIG. 5 , the design of the four-bar linkage is selected so that the upper swing arm 7 is configured to be shorter than the lower swing arm 8 . Moreover, the design of the four-bar linkage provides that the vertical distance or spacing between the rear axes 10 , 12 is greater than the vertical distance or spacing between the forward axes 11 , 13 . In the event of an impact, in which the bumper beam 1 presses against the radiator frame 4 , the forward axis 11 of the upper swing arm 7 moves on a smaller circular path 14 from the position 11 a to the position 11 b , whilst the forward axis 13 of the lower swing arm 8 moves around the axis 12 on a larger circular path 15 from a position 13 a into a position 13 b.
The effect of this movement sequence is that the radiator frame 4 is not only raised and pivoted to the rear but at the same time is also tilted, the tilting angle being oriented in the opposite direction than in the exemplary embodiment shown in FIG. 4 . The lower end of the radiator frame 4 is then moved closer to the passenger compartment during the pivoting movement than the upper end.
As may be seen, the distances between the axes of the swing arms provided on the retaining element and the axes of the swing arms provided on the radiator frame may be different, so that the swing arms are arranged at an angle to one another. If in such an exemplary embodiment the upper swing arm is configured to be longer than the lower swing arm, a movement of the radiator frame is achieved in which it is not only lifted up and pivoted to the rear but it also adopts a tilted position in which the upper region of the radiator frame pivots further to the rear than the lower region. Such a movement mechanism may be advantageous, for example, if in the upper engine compartment, for example above the engine block, there is sufficient space into which the radiator can be moved.
If, however, the upper swing arm is configured to be shorter than the lower swing arm, the radiator frames with the radiator pivots not only to the rear and upward but also into an inclined position in which the lower region of the radiator frame pivots further to the rear than the upper region. Accordingly, it behaves in the opposite manner if the upper swing arm is longer than the lower swing arm.
The tilting movement of the radiator frame with the radiator to the rear may be further reinforced by the distance between the axes arranged on the retaining element being selected to be shorter than the distance between the axes arranged on the radiator frame, the upper swing arm being longer than the lower swing arm.
The forwardly oriented tilting movement may be reinforced by the distance between the axes arranged on the retaining element being greater than the distance between the axes arranged on the radiator frame, the upper swing arm being configured to be shorter than the lower swing arm.
The three embodiments shown in FIGS. 3 to 5 may be selected according to various applicable packaging constraints, such the space available in the engine compartment. Any other variants of the four-bar linkage which achieve a different movement sequence of the radiator frame 4 are possible, as will be apparent to a person of skill in the art.
The technical design of the front-end structure which is shown more schematically in FIGS. 1 to 5 is illustrated in more detail in FIGS. 6 and 7 .
For example, the swing arms 7 , 8 , in particular in the form of the swing arm 7 , are shown in terms of construction. The swing arms 7 and 8 are provided at both ends with claws 16 and 17 , with which they engage over eyes 18 , 19 , which are provided on the radiator frame 4 and/or the retaining element 9 . By means of a pin-shaped element 20 , they are pivotably fastened to the respective eye 18 , 19 . Eyes 18 , 19 and the related pin elements 20 provide rear pivot points supporting the rear pivot axes of swing arms 7 , 8 .
In the example construction shown in FIGS. 6 and 7 , on both sides of the radiator frame 4 level with the bumper beam 1 one respective contact block 21 is arranged, on which the bumper beam 1 comes to bear after a specific amount of deformation of the deformation element 2 . The last-mentioned position after deformation of the deformation element 2 is illustrated in FIG. 7 , in which the bumper beam 1 has been forced out of the position 1 a into the position 1 b and then comes to bear against the contact block 21 , which preferably consists of resilient material, whereby the radiator frame 4 is displaced in the direction of the passenger compartment and at the same time lifted up.
The construction shown in FIGS. 6 and 7 may, for example, be designed according to any of the three basic models shown in FIGS. 3 to 5 , the construction of the four-bar linkage and the movement sequence of the radiator frame 4 associated therewith not being subjected to any restrictions.
Referring now to FIGS. 8A , 8 B, upper and lower swing arms 107 , 108 are attached to a retaining element 109 . In this embodiment, the rear pivot axes are provided by zones 110 , 112 of reduced cross-sectional area as compared with immediately adjacent areas. The zones 110 , 112 are therefore weakened and provide plastically deformable joints which yield when sufficient bending moment is applied by upward/rearward movement of the radiator frame. At least one axis of at least one swing arm may be configured as a plastically deformable joint. Where the swing arm is articulated to the frame structure and/or to the radiator frame, the swing arm and/or a corresponding fastening element has a construction which permits bending of the swing arm about a bending axis by the corresponding action of force. This bending axis thus corresponds to the pivot axis. Such a bending axis is formed by, for example, the swing arm being formed in the region of the bending axis partially as a flat metal plate, the metal plate only having a low bending stiffness in the direction of thickness. Then, with the action of force on the swing arm, said swing arm is plastically bent about this region automatically. In this manner, the construction of the articulation may be substantially simplified.
The disclosed construction has the advantage that in the region of the front module an extremely large deformation region is provided which optimally absorbs the impact energy and protects both occupants and pedestrians, whilst at the same time the radiator remains relatively undamaged at least in the event of an impact at low vehicle speeds. Moreover, by the arm design of the four-bar linkage, a predetermined movement path of the radiator frame may be predetermined which moves the radiator frame with the radiator into a predetermined position in which, depending on the construction of the engine compartment, sufficient space is present for the radiator frame carrying the radiator.
As required, detailed embodiments of the present invention are disclosed herein; however, it is to be understood that the disclosed embodiments are merely exemplary of the invention that may be embodied in various and alternative forms. The Figures are not necessarily to scale; some features may be exaggerated or minimized to show details of particular components. Therefore, specific structural and functional details disclosed herein are not to be interpreted as limiting, but merely as a representative basis for teaching one skilled in the art to variously employ the present invention.
While exemplary embodiments are described above, it is not intended that these embodiments describe all possible forms of the invention. Rather, 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 invention. Additionally, the features of various implementing embodiments may be combined to form further embodiments of the invention. | Forward structure of a motor vehicle includes a frame structure, a bumper beam disposed forward of and connected to the frame structure, and a radiator frame disposed forward of the frame structure and behind the bumper beam. First and second swing arms are connected to the radiator frame at respective first and second forward pivot axes and are connected to the frame structure at respective first and second rear pivot axes. The four pivot axes are substantially parallel to one another and substantially transverse to the vehicle, such that a frontal impact urging the bumper beam rearward against the radiator frame causes the radiator frame to pivot about the swing arms. Forward-most portions of the frame structure, immediately adjacent to the bumper beam, may take the form of deformation elements or crush cans that are designed to yield in a manner to absorb crash energy. | 1 |
FIELD
[0001] The subject matter disclosed herein relates to storage devices and methods for improving the stability of such devices.
[0002] Upright storage devices, such as dressers or cabinets or shelving units, typically have a rectangular cross-section, making them inherently unstable and susceptible to tipping at taller heights.
BRIEF DESCRIPTION
[0003] A storage device with a trapezoidal cross-section is more stable and less susceptible to tipping than a storage device with a rectangular cross-section, making such a device safer for people to interact with.
BRIEF DESCRIPTION OF THE DRAWINGS
[0004] FIG. 1 shows the rectangular cross-section of a typical storage device with each of the two base angles measuring approximately 90 degrees.
[0005] FIG. 2 shows the trapezoidal cross-section of a proposed storage device with one base angle measuring less than 90 degrees and the second base angle measuring approximately 90 degrees.
[0006] FIG. 3 shows the trapezoidal cross-section of a proposed storage device with each of the two base angles measuring less than 90 degrees.
[0007] FIG. 4 shows a tipping force comparison between a storage device with a rectangular cross-section and both base angles measuring approximately 90 degrees, a storage device with a trapezoidal cross section and one base angle measuring less than 90 degrees and the second base angle measuring approximately 90 degrees, and a storage device with a trapezoidal cross section and both base angles measuring less than 90 degrees.
[0008] FIG. 5 shows a tipping moment comparison between a storage device with a rectangular cross-section and both base angles measuring approximately 90 degrees, a storage device with a trapezoidal cross section and one base angle measuring less than 90 degrees and the second base angle measuring approximately 90 degrees, and a storage device with a trapezoidal cross section and both base angles measuring less than 90 degrees.
[0009] It is noted that the drawings are not necessarily to scale. The drawings are intended to depict only typical aspects of the subject matter disclosed herein, and therefore should not be considered as limiting the scope of the disclosure.
DETAILED DESCRIPTION
[0010] Certain exemplary embodiments will now be described to provide an overall understanding of the principles of the structure, function, manufacture, and use of the devices disclosed herein. One or more examples of these embodiments are illustrated in the accompanying drawings. Those skilled in the art will understand that the devices specifically described herein and illustrated in the accompanying drawings are non-limiting exemplary embodiments and that the scope of the present invention is defined solely by the claims. In the present disclosure, like-named components of the embodiments generally have similar features, and thus within a particular embodiment each feature of each like-named component is not necessarily fully elaborated upon. Additionally, to the extent that linear, circular, or angular dimensions are used in the description of the disclosed devices, such dimensions are not intended to limit the types of shapes that can be used in conjunction with such devices. The features illustrated or described in connection with one exemplary embodiment may be combined with the features of other embodiments. Such modifications and variations are intended to be included within the scope of the present invention.
[0011] In some embodiments, a storage device can include a trapezoidal cross-section with one or both of its base angles to be less than 90 degrees, the acuteness of which can vary from slightly to significantly.
[0012] The storage devices described herein can be used to contain anything item of any size, or the devices may contain nothing and exist solely for decorative purposes.
[0013] The storage devices described herein may be constructed of any material.
[0014] The storage devices described herein may contain shelves, drawers, or open space and cabinet doors of sliding, hinged, rolled or other style as an access point to the shelves, drawers, or open space.
[0015] FIG. 1 shows the rectangular cross-section of a typical storage device 100 with each of the two base angles 101 and 102 measuring approXimately 90 degrees.
[0016] FIG. 2 shows the trapezoidal cross-section of a proposed storage device 103 with one base angle 104 measuring less than 90 degrees and the second base angle 105 measuring approximately 90 degrees.
[0017] FIG. 3 shows the trapezoidal cross-section of a proposed storage device 106 with each of the two base angles 107 and 108 measuring less than 90 degrees.
[0018] FIG. 4 shows a tipping force comparison between a storage device with a rectangular cross-section 100 and both base angles 101 and 102 measuring approximately 90 degrees, a storage device with a trapezoidal cross section 103 and one base angle 104 measuring less than 90 degrees and the second base angle 105 measuring approximately 90 degrees, and a storage device with a trapezoidal cross section 106 and both base angles 107 and 108 measuring less than 90 degrees. If enough horizontal force is applied to the top of a storage device, the storage device can be tipped or raised from the surface on which it is resting. The horizontal force 109 required to tip a storage device with a rectangular cross section is significantly less than the horizontal force 110 required to tip storage devices with trapezoidal cross sections 103 and 106 , given that the heights 111 and bases 112 of all storage devices are equal. Thus, a storage device with a trapezoidal cross-section is more stable and less susceptible to tipping than a storage device with a rectangular cross-section, making such a device safer for people to interact with.
[0019] FIG. 5 shows a tipping moment comparison between a storage device with a rectangular cross-section 100 and both base angles 101 and 102 measuring approximately 90 degrees, a storage device with a trapezoidal cross section 103 and one base angle 104 measuring less than 90 degrees and the second base angle 105 measuring approximately 90 degrees, and a storage device with a trapezoidal cross section 106 and both base angles 107 and 108 measuring less than 90 degrees. If enough vertical force is applied to the top of a storage device (for example, if the top drawer of a dresser is pulled open), the storage device can be tipped or raised from the surface on which it is resting by the resultant moment. The vertical force 113 required to tip a storage device with a rectangular cross section is significantly less than the vertical force 114 required to tip storage devices with trapezoidal cross sections 103 and 106 , given that the heights 111 and bases 112 of all storage devices are equal. Thus, a storage device with a trapezoidal cross-section is more stable and less susceptible to tipping than a storage device with a rectangular cross-section, making such a device safer for people to interact with. | An exemplary design for upright storage devices, such as dressers or cabinets or shelving units, to dramatically improve stability, and thus safety, is provided. In general, such storage devices can be constructed with one or both base angles measuring less than 90 degrees, giving them a trapezoidal cross section. | 0 |
TECHNICAL FIELD
The present invention relates generally to a shoe and more specifically, relates to a shoe having a fabric material disposed on at least a portion of the outsole and to a manufacturing process thereof.
BACKGROUND OF THE INVENTION
A shoe is generally formed of an upper, a lower attached to the upper, and an outsole attached to the lower. The outsole of the shoe is the exposed portion of the sole that contacts the ground or other supporting surface. The outsole provides many characteristics of the shoe such as the shoe's traction and stability with respect to the intended supporting surface. For example, the outsole of the shoe may be provided with some type of traction elements arranged in a pattern to provide a gripping action between the outsole and the ground or supporting surface. The outsole should also be manufactured so that it offers extended wear to permit the shoe to be worn for a lengthy period of time.
Often, the outsole of the shoe is formed of a rubber material or leather in designer shoes and the like. In men's and women's shoes, the outsole is very often substantially smooth and this can cause traction problems. For example, such outsoles are often very slippery because of their smooth texture and this increases the chances that the user may accidently slip or slide during normal use. The risk of slipping and sliding is increased significantly when the surface or supporting surface is wet or otherwise in a slippery state.
The outsole is an important component of the shoe for an additionally entirely unrelated reason which has gone unrecognized in the art of shoe sole construction. As the economies of most countries become more and more internationalized, international commercial transactions invoke national customs tariffs that generally must be paid when goods are shipped. Under the Harmonized Tariff Schedules of each country, goods are classified under various categories. For example, most footwear is classified under Chapter 64 of the United States Harmonized Tariff Schedules which covers the importation of goods into the United States. Within this chapter, the following major headings are recited for footwear:
6401 Waterproof Rubber or Plastic Footwear; 6402 Other Footwear with Uppers and Outersoles of Rubber or Plastic; 6403 Footwear with Uppers of Leather and Outersoles Of Rubber, Plastic, Leather, or Composition Leather; 6404 Footwear with Uppers of Textiles and Outersoles of Rubber, Plastic, Leather, or Composition Leather; and 6405 Other Footwear.
Accordingly, footwear is generally classified in a given heading based upon the material of the upper and the material of the outersole. Consequently, the outsole plays an important role in determining the rate of duty which is to be applied to the specific footwear article. Depending upon the material which is used to manufacture the upper and the sole, the rate of the duty may vary significantly. For example, the rate of duty may range from 37.5% ad valorem for many common types of footwear to 3% ad valorem for certain types of sandals and similar footwear. In determining the applicability of a particular section of one chapter of the United States Harmonized Tariff Schedules, knowledge of specific details of the material is necessary. For example, a classification may be based on the type of material that is present on 50% or more of the bottom surface of the shoe (outersole) that contacts the ground.
Over many years, manufacturers have focused their attention on improving the traction properties of shoe outsole construction, but have not recognized that a price advantage can be had by combining materials in the outer shoe sole construction.
What is needed in the art and has heretofore not been available is an outsole and method of manufacture thereof which offers slip resistance and other desirable properties in addition to providing a competitive advantage to the manufacturer based on its construction.
SUMMARY OF THE INVENTION
According to the present invention, a shoe including an upper, a lower attached to the upper, and an outsole attached to the lower is presented. In one embodiment, the outsole has a ground contacting surface which includes a first section and a second section, with the first section being formed of a first material and the second section having an outer later formed of a fabric material. The first section is free of any fabric material and is instead formed of other suitable materials, such as rubber, leather, etc.
In another embodiment, the ground contacting surface substantially consists of a shaped fabric member having the fabric material disposed on an outer surface thereof. The shaped fabric member extends below other surrounding sections of the outsole which do not contain a fabric material, so as to form a ground contacting surface of the outsole.
According to the present invention, the outsole is preferably formed using a molding process and, more specifically, is formed using a two stage molding process. The fabric material is not just layered over an existing outsole construction but rather forms an integral part of the outsole construction itself. In one embodiment, a shaped fabric member having the fabric material disposed on an outer surface thereof is formed during a first molding process and then the shaped fabric member is disposed in a second mold. A second molding process is conducted and the remaining portion of the outsole is formed around the shaped fabric member which becomes an integral part of the outsole. The result is that an integral outsole is produced in which a substantial amount of the ground contacting surface of the outsole is defined by the fabric material. Preferably, greater than 50% of the ground contacting surface of the outsole includes the fabric material.
In accordance with the present invention, the outsole provides increased slip resistance, is durable, and provides a competitive manufacturing advantage.
Other features and advantages of the present invention will be apparent from the following detailed description when read in conjunction with the accompanying drawings.
BRIEF DESCRIPTION OF THE DRAWINGS
The foregoing and other features of the present invention will be more readily apparent from the following detailed description and drawings of illustrative embodiments of the invention in which:
FIG. 1 is a bottom perspective view of one exemplary type of shoe having an outsole in accordance with one embodiment of the present invention;
FIG. 2 is a bottom plan view of the shoe of FIG. 1 ;
FIG. 3 is a cross-sectional view taken along the line 3 — 3 of FIG. 1 ;
FIG. 4 is a bottom plan view of the shoe of FIG. 1 showing a fabric portion of the outsole peeled back to expose a backing portion of the outsole;
FIG. 5 is a bottom perspective view of another exemplary type of shoe having an outsole in accordance with the present invention;
FIG. 6 is a bottom plan view of shoe of FIG. 1 ;
FIG. 7 is a cross-sectional view taken along the line 7 — 7 of FIG. 6 ;
FIG. 8 is a bottom perspective view of another exemplary type of shoe having an outsole in accordance with the present invention;
FIG. 9 is a bottom plan view of the shoe of FIG. 8 ;
FIG. 10 is an exploded perspective view of a first mold including first and second dies;
FIG. 11 is perspective view of a shaped fabric member formed during a process using the first mold of FIG. 10 and for use in an outsole in accordance with the present invention; and
FIG. 12 is a perspective view of a second mold in an open position, the second mold including first and second dies, with the shaped fabric member of FIG. 11 being placed in one of the first and second dies.
DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS
The present invention will be first described with reference to FIGS. 1 through 4 . FIG. 1 illustrates one exemplary type of shoe 10 having an upper 20 , a lower 30 attached to the upper 20 , and an outsole 40 attached to the lower 30 . The shoe 10 is of a style which is commonly worn by women in both workplace settings and social settings. The style and nature of shoe 10 is merely exemplary and it will be understood that the present invention applies to a wide range of types of shoes, including but not limited to men's, women's, and children's shoes.
FIG. 3 is a cross-sectional view of the shoe 10 showing its construction in greater detail. The upper 20 includes a soft cushioned material, such as a fabric-backed foam 22 at an interior portion of the shoe 10 for resiliently engaging a wearer's foot. The fabric-backed foam 22 thus serves to cushion the wearer's foot during use and reduce impact between the foot and the surrounding environment. The upper 20 also includes an exterior cover 24 , such as a high pile fabric, coupled to the fabric-backed foam 22 . For example, the exterior cover 24 may be stitched to the fabric-backed foam 22 . It will be appreciated that the upper 20 may be formed of a number of different materials and foam and high pile fabric are merely exemplary materials. For example, the exterior cover 24 may be formed of leather or the like or velvet or the like, especially for women's shoes.
The lower 30 includes a base material 32 at the interior of the shoe 10 for engaging the wearer's foot. Typically, the base material 32 is formed of a foam or a fabric and may be formed of multiple layers. For example, the base material 32 of the exemplary shoe 10 actually includes a thin top layer 34 which may be formed of any number of materials, including a fabric and a suitable plastic material. Underneath the top layer 34 is a cushion element 35 which preferably has an identical shape as the top layer 34 . The cushion element 35 is preferably formed of a soft cushioned material, such as a foam. It will be appreciated that the top layer 34 and cushion element 35 may be formed as a single integral piece.
Underneath the cushion element 35 , a support layer 36 is provided.
The support layer 36 is also preferably similarly or identically shaped as the top layer 34 and the cushion element 35 and is designed to act as a backbone of the lower 30 . The support layer 36 is formed of a rigid material so that it maintains its shape under application of force, such as the weight of the wearer. The support layer 36 may be formed of any number of rigid materials, such as a rigid plastic, a rigid reinforced cardboard member, etc. The cushion element 35 is coupled to the support layer 36 using any number of techniques, including applying an adhesive to a backside of the cushion element 35 and then applying the cushion element 35 to a topside of the support layer 36 .
The upper and lower 20 , 30 of the shoe are attached to one another using any number of techniques. For example and as shown in the cross-sectional view of FIG. 3 , a portion of the upper 20 , and more specifically a portion 26 of the exterior cover 24 , is tucked underneath an edge of the lower 30 to secure the upper 20 . The exterior cover 24 may be secured to the lower 30 by applying an adhesive or the like to the area where the exterior cover 24 and the lower 30 meet.
In accordance with the present invention, the outsole 40 is made of a rigid material so as to provide support to the outsole 40 and includes an outer surface 42 . The outsole 40 may have any number of shapes depending upon the type of shoe 10 . For example, shoe 10 is a typical women's shoe and therefore includes a prominent heel 50 . When shoe 10 has a heel, such as heel 50 , the heel 50 may be formed as a separate member from the outsole 40 or the heel 50 may be integrally formed as part of the outsole 40 . In the exemplary shoe 10 , the heel 50 is a separate member which is coupled to the outsole 40 using known techniques. Preferably, an upper portion of the heel 50 , in the form of a lip 51 , extends around a heel portion of the exterior cover 24 . This lip portion 51 is coupled to the adjacent heel portion of the exterior cover 24 using an adhesive or the like. A bottommost portion 53 of the heel 50 engages the ground or support surface and therefore may be formed of a suitable material for such wear. For example, the bottommost portion 53 may be formed of the same material as the other portions of the heel 50 or may be formed of a different material. The major portion of the heel 50 is preferably formed of a rigid material, such as a rigid plastic or wood. The bottommost portion 53 may be formed of this type of material or may be in the form of a shaped rubber pad which is coupled to the other portions of the heel 50 , as shown in FIGS. 1-2 .
As is known in the art, different portions of the outsole 40 of shoe 10 are referred to differently. The outsole 40 of shoe 10 includes the heel 50 formed at one end and includes a ball portion 49 formed generally at an opposite end of the shoe 10 . The ball portion 49 is the portion of the outsole 40 which primarily contacts the ground during normal use of the shoe 10 . Between the ball portion 49 and the heel 50 , the outsole 40 includes a shank 55 which does not contact the ground during wear of the shoe 10 . The shank 55 is thus angled upwardly away from the ground surface when the ball portion 49 and the heel 50 are seated against the ground. The height of the heel 50 determines the angle between the shank 55 and the ground surface.
In accordance with the present invention, the outsole 40 also includes a shaped fabric member 60 which forms a part of the outsole 40 and has a predetermined shape. As best shown in FIG. 3 , the shaped fabric member 60 includes a thin, flexible, fabric sheet material 62 and a backing layer 64 . Preferably, the fabric sheet material 62 is formed of a non-woven fabric, such as polyester fibers mixed with cotton. Thus, the fabric sheet material 62 is not produced using a weaving process but rather is produced using other suitable techniques for forming a non-woven fabric. For example, the polyester fibers may used to form a needle felt which is then impregnated with a material before being dried and pressed. It will be appreciated that the shaped fabric member 60 may have any number of shapes and sizes depending upon the shoe design and other parameters such as the amount of contact between the outsole 40 and the ground or support surface.
In accordance with the present invention, the shaped fabric member 60 is disposed on a significant and preferably substantial portion of the outsole 40 which engages the ground or support surface during normal use. More specifically, the shaped fabric member 60 preferably occupies an area which is at least greater than 50% of the area of the outsole 40 which contacts the ground. In the exemplary shoe 10 shown in FIGS. 1-3 , the ground contacting portion of the outsole 40 includes the bottommost portion 53 of the heel 50 and the ball portion 49 . It will be appreciated that the percent of the ground contacting surface of the shoe 10 that includes the shaped fabric member 60 will depend upon a number of factors, including but not limited to the type of shoe 10 (i.e., high heel or not) and the area of ground contacting surface as a percentage of the total area of the outsole 10 . For example, the shaped fabric member 60 preferably occupies greater than 50% to about 90% of the entire ground contacting surface of the outsole 40 .
In the shoe 10 , the shaped fabric member 60 is disposed within the outsole 40 and more preferably is disposed within the ball portion 49 of the outsole 40 . Preferably, the shaped fabric member 60 is integrally formed as part of the outsole 40 as will be described hereinafter. The bottommost portion 53 of the heel 50 is formed of a rubber or other suitable material. A gap 63 is formed between the fabric sheet material 62 and a surrounding edge 71 of the outer surface 42 of the outsole 40 . As shown in the figures, the outer surface 42 of the outsole 40 surrounds the shaped fabric member 60 . When the shaped fabric member 60 is disposed within the outsole 40 , an outer face of the fabric sheet material 62 is preferably substantially planar to the surrounding outer surface 42 of the outsole 40 so that during use, the outsole 40 engages the ground in a relatively uniform manner.
The backing layer 64 is preferably formed of a shape-retaining material, for example, a rubber or plastic material. The backing layer 64 and the fabric sheet material 62 are integrally connected to one another by any number of techniques, including using a molding process as will be described in greater detail hereinafter. In addition, the surrounding outsole 40 and the backing layer 64 may be formed of the same material or may be formed of different materials. In one exemplary embodiment, both are formed of a thermoplastic. In another embodiment, both are formed of a material that is referred to herein as a thermoplastic rubber.
The shaped fabric member 60 along with the surrounding outsole 40 provide the shoe 10 with a slip-resistance, shape-retaining partially fabric outsole 40 . It is also contemplated that the outer surface 42 and/or the backing layer 64 may have a tread pattern formed thereon for a decorative purpose, a functional purpose, or both. For example, the surface 42 and the layer 64 can have a tread pattern, and in the case of the backing layer 64 , the fabric sheet material 62 can closely conform to the pattern, e.g., follow the contour thereof.
The use of the shaped fabric member 60 also has another associated advantage: the provision of the fabric sheet material 62 on greater than 50% of the ground contacting surface area of the outsole 40 enables the shoe 10 to be classified under a different section of the United States Harmonized Tariff Schedules and therefore permits the manufacturer of the shoe 10 to pay a different, lower rate of tariff duty. In other words, the classification of the shoe 10 for tariff purposes depends, in part, on the constituent material of the upper 20 and the constituent material of the outsole 40 (based upon the greatest surface area in contact with the ground). In the exemplary shoe 10 , the upper 20 is formed of a textile material and the constituent material of the outsole 40 is also a textile material because the material which occupies the greatest surface area in contact with the ground is the fabric sheet material 62 (a material classified as a textile).
By having both the upper 20 and the outsole 40 formed of a textile material, the shoe 10 can be classified under “Other Footwear, with uppers of textile materials, Other” which has a lower rate of duty than footwear having a textile upper and an outersole formed of rubber, plastic, leather, or composition leather. Under the current United States Harmonized Tariff Schedules, the shoe 10 of the present invention is classifiable under subheading 6405.20.90, which carries a 12.5% rate of duty so long as greater than 50% of the ground contacting surface area of the outsole 40 is occupied by the fabric sheet material 62 . This is significantly lower than a 37.5% rate of duty applied to many types of footwear with outersoles of rubber, plastics, leather or composition leather and uppers of textile materials. Thus, associated costs for the overall manufacturing and delivering process can be significantly reduced by decreasing the rate of duty which is applied to the footwear (shoe 10 ). This results in a competitive advantage.
The manufacture of shoe 10 and more specifically, the outsole 40 will now be described in greater detail with reference to FIGS. 1-3 and 10 - 12 . A two step molding process is preferably used to manufacture the outsole 40 . In a first molding process, the shaped fabric member 60 is formed. Initially, a piece of the fabric sheet material 62 is cut to a predetermined shape and size.
Preferably, the fabric sheet material 62 is a non-woven fabric, such as polyester fibers with cotton. This cut piece of the fabric sheet material 62 is then inserted into a first mold 100 . The first mold 100 is a conventional mold having a first shaped die 102 and a second shaped die 104 . The first and second dies 102 , 104 have one or more cavities formed therein which define the shape of the shaped fabric member 60 and are generally shaped so as to be accommodated in the ball portion 49 of the outsole 40 . The cut piece of fabric sheet material 62 is held in place again the first shaped die 102 .
The first and second dies 102 , 104 are heated to a predetermined temperature which permits the molding process to proceed without damaging or destroying the fabric sheet material 62 . The predetermined temperature which is required for the molding process will depend upon a number of factors, including the type of thermoplastic resin used in the molding process. In one exemplary embodiment, the first and second dies 102 , 104 are heated to a temperature of about 120° C. when a thermoplastic rubber is used to form the backing layer 64 . The first and second dies 102 , 104 are pressed together with the fabric sheet material 62 being held in place against the first die 102 and then the thermoplastic rubber is injected into the first mold 100 after the thermoplastic rubber has been melted to a softened state by being exposed to a sufficient temperature (120° C.).
Because the thermoplastic rubber is in a softened state, it is able to flow throughout a cavity formed by the first and second dies 102 , 104 . The thermoplastic rubber forms the shape of the backing layer 64 once the thermoplastic rubber cools after a predetermined time period in which the temperature of the first mold 100 is reduced. The result is that the shaped fabric member 60 is formed and the thermoplastic rubber and the fabric sheet material 62 are bonded to one another by the heating process of the molding operation. Once the shaped fabric member 60 has sufficiently cooled down, the first and second dies 102 , 104 are opened and the shaped fabric member 60 is removed therefrom. Excess fabric sheet material 62 is cut off from the shaped fabric member 60 to provide for the shaped fabric member 60 shown in FIG. 11 . As previously discussed, the shaped fabric member 60 includes the fabric sheet material 62 bonded to the backing layer 64 .
In a second molding operation, the shaped fabric member 60 is placed into a second mold 200 , shown in FIG. 12 . The second mold 200 includes a first die 202 and a second die 204 . The first and second dies 202 , 204 define a cavity which is generally in the shape of the outsole 40 . It will be appreciated that the cavity may not necessarily define the entire heel structure 50 of the outsole 40 but will likely define the remaining portions, e.g., the shank 53 and the ball portion 49 . The shaped fabric member 60 ( FIG. 11 ) is inserted into the first mold 202 with the fabric sheet material 62 facing a bottom section 203 of the first die 202 . Consequently, the backing layer 64 faces the second die 204 when the second die 204 is closed.
The first and second dies 202 , 204 are heated to a predetermined temperature and are closed with respect to one another. Once again, the predetermined temperature is a temperature at which the first and second dies 202 , 204 will not damage the fabric sheet material 62 but will permit (1) the thermoplastic rubber forming the backing layer 64 to resoften and (2) permit a second thermoplastic rubber material to soften sufficiently so that it may be injected into the second mold 200 . Preferably, the predetermined temperature of the second mold 200 is greater than the predetermined temperature of the first mold 100 . In one exemplary embodiment, the predetermined temperature of the second mold 200 is from about 160° C. to about 170° C. It will be appreciated that suitable molding temperatures will vary depending upon a number of parameters, such as the operating conditions and the type of thermoplastic rubber being used.
The second thermoplastic rubber material is injected into the second mold 200 so that if flows within the cavity formed by the first and second dies 202 , 204 . Because the backing layer 64 is softened, the heated, injected second thermoplastic rubber material may bond with the backing layer 64 . In one embodiment, the thermoplastic rubber material used in both the first and second molds 100 , 200 is the same material. It will be appreciated that the thermoplastic rubber material used in the first and second molds 100 , 200 may be different materials. After heating the materials in the second mold 200 for a sufficient time period, the molds 202 , 204 are cooled causing the resultant outsole 40 to cool. After a sufficient cooling period, e.g., several minutes (i.e. 6 or more minutes), the first and second molds 202 , 204 are opened and the outsole 40 is removed.
The outsole 40 preferably has the shaped fabric member 60 integrally formed as a part thereof due to the bonding between the backing layer 64 and the surrounding outsole 40 . Preferably, the second mold 200 is configured so that the fabric sheet material 62 is not in contact with the second thermoplastic rubber that is injected into the second mold 200 . In the shoe 10 , the gap 63 separates the fabric sheet material 62 from the surrounding outer surface 42 of the outsole 40 . In other words, the outsole 40 is formed around the shaped fabric member 60 so that the ground contacting surface of the outsole 40 is formed of the fabric sheet material 62 and a portion of the outer surface 42 with both components being preferably generally planar with one another and exposed to contact the ground.
After having formed the outsole 40 using the above-described method, the outsole 40 is then incorporated into the shoe 10 by attaching the outsole 40 to the lower 30 to form the shoe 10 .
As shown in FIG. 4 , the outsole 40 and the corresponding manufacturing process may be modified so that a pattern 230 is formed as part of the shaped fabric member 60 . This pattern 230 may be decorative in nature and also provides some functionality as it may be designed to increase the gripping action of the outsole 40 . In one embodiment, a bottom of the first die 102 is modified by forming the pattern 230 thereon. For example, small diamond shaped objects may be formed on the first die 102 ( FIG. 10 ) and the fabric sheet material 62 is laid over the first die 102 . During the first molding process, the pattern 230 is transferred onto the shaped fabric member 60 as a result of the injection and pressing action of the thermoplastic rubber. The resultant shaped fabric member 60 thus includes a textured surface defined by the pattern 230 .
FIGS. 5-7 show another embodiment of the present invention. In this embodiment, a shoe 300 is presented and is generally in the form of a women's shoe having an open aired toe. The shoe 300 includes an upper 310 , a lower 320 attached to the upper 310 , and an outsole 330 attached to the lower 320 .
Because of the open toe nature of shoe 300 , the upper 310 is formed of a toe strap 312 and an ankle strap 314 . The toe and ankle straps 312 , 314 may be formed of any number of suitable materials and in one embodiment, the straps 312 , 314 are formed of a backing layer 316 and an exterior cover 318 . The backing layer 316 may comprise a fabric backed foam or the like with the exterior cover 318 being attached to the backing layer 316 using known techniques, such as stitching, etc. The exterior cover 318 may be formed of any number of materials, including a high pile fabric. In this embodiment, the ankle strap 314 also includes a buckle assembly 319 for securing the ankle strap 314 around a wearer's ankle. The toe strap 312 is designed to extend across the upper portion of the foot near the wearer's toes to secure the front portion of the foot within the shoe 300 . The toe strap 312 should be flexible so as to accommodate foots of different sizes.
The lower 320 includes a fabric-backed foam 322 and a support member 324 . The fabric-backed foam 322 provides a cushioned surface for the wearer to place his/her foot. The support member 324 serves to provide a support platform for the wearer's foot and therefore is formed of a rigid material. For example, the support member 324 may be formed of a rigid reinforced cardboard member, a plastic member, a wooden member, etc. so long as the support member 324 retains its shape and provides adequate support to the wearer's foot.
The upper 310 is attached to the lower 320 using conventional techniques, including stitching or securing ends of the straps 312 , 314 to the lower 320 and more specifically, by tucking these ends between the support member 324 and the outsole 330 . An adhesive or other material may be used to secure the straps 312 , 314 to at least one of the support member 324 and the outsole 330 .
The outsole 330 in this embodiment includes a shaped fabric member 340 formed as part of the outsole 330 and a heel 360 . The outsole 330 also includes an outer surface 332 . As best shown in FIGS. 5 and 7 , the shaped fabric member 340 is disposed in a ball portion 331 of the outsole 330 and protrudes below the surrounding portions (outer surface 332 ) of the outsole 330 such that the shaped fabric member 340 is the ground contacting portion of the outsole 330 . During normal wear, the wearer contacts the ground surface with the shaped fabric member 340 because it extends below the surrounding sections of the outsole 330 .
The heel 360 is attached to the outer surface 332 using conventional techniques, e.g., use of an adhesive, and a bottommost portion 362 of the heel 360 preferably includes a rubber or plastic piece which reduces wear of the heel 360 and provides a gripping surface. A shank portion 363 of the outsole 330 is formed between the heel 360 and the ball portion 331 . The shank portion 363 is defined by the outsole 330 and does not include the shaped fabric member 340 . The shaped fabric member 340 is thus only provided on sections of the outsole 330 which contact the ground surface during normal wear.
As best shown in FIG. 7 , the shaped fabric member 340 is formed of a fabric sheet material 343 and a fabric backing layer 345 . As will be described hereinafter, the backing layer 345 is preferably integrally bonded to the material forming the outsole 330 and preferably, the layer 345 and the outsole 330 are formed of the same material so that it will appear to the wearer that the fabric sheet material 343 is simply attached to a particular section of the outsole 330 . The backing layer 345 is the material lying immediately underneath the fabric sheet material 343 and serves to define a platform extending downwardly from the surrounding sections of the outsole 330 . In this manner, the fabric sheet material 343 is only in contact with the backing layer 345 and not the surrounding sections of the outsole 330 .
In this embodiment and in accordance with the present invention, greater than 50% (as measured in terms of area) of the ground contacting sections of the shoe 300 includes the shaped fabric member 340 . In the exemplary shoe 300 shown in FIGS. 5-7 , the ground contacting surface of the outsole 330 includes the bottommost portion 362 of the heel 360 and the ball portion 331 . More specifically, besides the heel portion 362 , the only other portion of the outsole 330 which contacts the ground surface is the shaped fabric member 340 . Thus in this particular embodiment, the shaped fabric member 340 comprises a substantial portion of the ground contacting surface of the outsole 330 as the outer surface 332 does not contact the ground surface.
The manufacture of the shoe 300 is preferably done in a similar or the same manner as the manufacture of the shoe 10 described in reference to FIGS. 10-12 . More specifically, the manufacture is preferably a two stage molding process using the first and second molds 100 , 200 . In this embodiment, the bonding between the backing layer 345 and the outsole 330 is clearly shown in the cross-sectional view of FIG. 7 . After forming the shaped fabric member 340 using the first mold 100 , the member 340 is then placed in the second mold 200 to form the outsole 330 illustrated in FIGS. 5-7 . During the second molding process, the fabric sheet material 342 is not in contact with the second thermoplastic rubber that is added to the second mold 200 to form the remaining sections of the outsole 330 but rather the second thermoplastic rubber is disposed over and around the heated fabric backing layer 344 (preferably a thermoplastic rubber also).
Now referring to FIGS. 8-9 which illustrate yet another embodiment of the present invention. In this embodiment, a shoe 400 is presented and generally includes an upper 410 , a lower 420 , and an outsole 430 . The shoe 400 is in the form of a walking or leisure type shoe instead of the more formal shoes shown in FIGS. 1-7 . The upper 410 and lower 420 have conventional constructions and are attached to one another using conventional techniques. The outsole 430 is also attached to the lower 420 using conventional techniques.
According to the present invention, the outsole 430 includes a shaped fabric member 440 and a surrounding outsole surface 450 . The shaped fabric member 440 has a fabric sheet material 442 disposed on an outer surface thereof so that the fabric sheet material 442 contacts the ground surface or the like during normal wear of the shoe 400 . Bottom portions (surface 450 ) of the outsole 430 surrounding the shaped fabric member 440 are formed of any number of suitable materials including but not limited to plastic and rubber materials. The bottom portions of the outsole 430 are preferably generally planar with respect to the shaped fabric member 440 to define a substantially planar ground contacting surface of the outsole 430 . In this embodiment, the shoe 400 includes two shaped fabric members 440 , one disposed proximate a heel portion 402 of the shoe 400 and the other disposed proximate to a toe portion 404 of the shoe 400 . A gap 444 is formed between the fabric sheet material 442 and the outer surface 432 of the outsole 430 in one exemplary embodiment.
According to the present invention, the shaped fabric members 440 occupy an area which is at least greater than 50% of the area of the outsole 430 which contacts the ground surface. Preferably, the shaped fabric members 440 occupy greater than 50% to about 90% of the entire ground contacting surface of the outsole 430 . The shaped fabric members 440 may have any number of shapes and sizes so long as the shaped fabric members 440 occupy greater than 50% of the surface of the outsole 430 which contacts the ground surface during normal wear.
The shoe 400 is preferably formed using the manufacturing process described herein with reference to FIGS. 10-12 . In other words, the shaped fabric members 440 are formed using a first molding process and then are inserted into the second mold 200 ( FIG. 12 ) where a second molding process is conducted. During the second molding process, the outsole 330 is formed having the shaped fabric members 440 as integral parts thereof. The result is that the outsole 430 of the shoe 400 is partially covered with fabric sheet material 442 , while surrounding portions of the outsole 430 do not contain the fabric sheet material 442 and are formed of suitable materials. It will be appreciated that while thermoplastic rubbers are preferred for use in the molding process, other types of materials may be used so long as they produce the shaped fabric member having the characteristics described herein with reference to the various embodiments of the present invention.
The present invention thus provides an outsole and a manufacturing process thereof which present an outsole having a ground contacting surface, wherein the ground contacting surface has a portion thereof which is defined by a fabric sheet material. Advantageously, the outsole of the present invention is slip-resistant, durable, and offers a competitive advantage to the manufacturer.
While the invention has been particularly shown and described with reference to preferred 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 invention. | Improvements in shoe constructions are provided that provide ground contacting surfaces of multiple materials that resist separation from one another and which provide traction and tariff benefits. | 0 |
TECHNICAL FIELD
[0001] The present invention relates to improved absorbents for absorbing CO 2 from a gaseous mixture, and a method for absorbing CO 2 using said absorbents. More specifically, the present invention relates to specific amine compositions that spontaneously form two separated phases after absorbing CO 2 , and a method for capturing CO 2 from gas mixtures, such as e.g. exhaust gas from combustion of carbonaceous fuels, industrial off-gases and blast furnace gases in the iron and steel production, using said amine compositions.
BACKGROUND ART
[0002] Capture of CO 2 from a mixture of gases on an industrial scale has been known for decades, e.g. for separation of natural gas and CO 2 from sub terrain gas wells to give natural gas for export and CO 2 for return to the sub terrain structure.
[0003] The growing concern on global warming and the greenhouse effect of CO 2 from combustion of fossil fuels has caused a growing interest in CO 2 capture from major points of emission of CO 2 such as thermal power plants.
[0004] U.S. Pat. No. 5,618,506 A (THE KANSAI ELECTRIC POWER CO., AND MITSUBISHI JUKGYO KABUSHIKI KAISHA) Apr. 8, 1997, and EP 0558019 B (KANSAI ELECTRIC POWER CO, AND MITSUBISHI HEAVY IND LTD) Dec. 27, 1996, and the citations indicated therein, give a general background of processes and absorbents for capturing of CO 2 .
[0005] Industrial CO 2 capturing plants include an absorber, in which a liquid absorbent is brought into counter current contact with the gas to be treated. A “purified” or low CO 2 content gas is withdrawn at the top of the absorber and is released into the atmosphere, whereas a CO 2 rich absorbent is withdrawn from the bottom of the absorber. The rich absorbent is regenerated in a regeneration column where the rich absorbent is stripped by counter current flow with steam that is generated by heating of regenerated absorbent at the bottom of the regeneration column. The regenerated absorbent is withdrawn from the bottom of the regeneration column and is recycled into the absorber. A CO 2 rich gas, mainly comprising steam and CO 2 is withdrawn from the top of the regeneration column. The CO 2 rich gas is treated further to remove water, and compressed before the CO 2 is sent for storage or other use.
[0006] Capture of CO 2 is, however, an energy demanding process, as the binding of CO 2 to the absorbent is an exothermal reaction and the regeneration is an endothermal reaction. Accordingly, heat is to be added to the regeneration column to regenerate the absorbent and release the CO 2 . This heat demand is a major operating cost for a plant for CO 2 capture. A reduction of the heat requirement for regeneration of the absorbent is therefore sought to reduce the energy cost for the CO 2 capture.
[0007] Amines having a less exothermic reaction when absorbing CO 2 do, however, normally have slower reaction kinetics. Slower reaction kinetics will require a longer contact time between the CO 2 containing gas and the absorbent. A longer contact time will require a larger absorber for handling the same gas volume.
[0008] Many different amines and combinations have been suggested as absorbents for CO 2 , the different amines having different CO 2 absorption capabilities, see e.g. the above mentioned patents. Additional examples on amine absorbents for capture of CO 2 and/or other acid gases from a gas mixture may be found i.a. in WO 2009/027491 A (SHELL INTERNATIONAL RESEARCH MAATSCHAPPIJ) Mar. 5, 2009, US 2008078292 A (MIMURA TOMITO) Apr. 3, 2008, and BRUDER/P, SVENDSEN, H. F. Solvent comparison for postcombustion CO2 capture. Post combustion capture conference 2011, Abu Dhabi May 2011.
[0009] The energy required to regenerate the absorbent is a major fraction of the total energy consumption for CO 2 capture. This energy is related to the heat of absorption, as the exothermic reaction taking place in the absorber will have to be reversed by addition of heat in the reboiler, and also to the shift in CO 2 equilibrium with temperature.
[0010] The energy cost is assumed to be the predominant running cost for a plant for CO 2 capture. The heat consumption is a combination of three factors (heat of absorption, heat for stripping and sensible heat loss in amine/amine exchanger).
[0011] Different approaches have been tried to improve the energy efficiency of carbon capture, such as heat integration to keep heat energy in the process and testing to find the best absorbent/mixture of absorbents.
[0012] Additionally, approaches for reducing the total mass of absorbent to be heated for regeneration, were only the CO 2 loaded part of the absorbent is sent to the regenerator, have been suggested and tested in laboratories.
[0013] US 2007237695 A (LIANG HU) Oct. 11, 2007 relates to a method and system for gas separation using a liquid absorbent absorbing one of the gases to be separated, where the absorbent spontaneously separates into a phase rich in the absorbed gas, and a phase lean in the absorbed gas. The active agent in the not identified but preferred agents is indicated to be selected from the group consisting of alkaline salts, ammonium, alkanolamines, amines, amides and combinations thereof. US 20090263302 A (LIANG HU) Oct. 22, 2009 is a continuation in part (CIP) of a CIP of US2007237695, and is further developed to indicate possible groups of active agents for the absorbent.
[0014] WO 2010/126694 A (LIANG HU) Nov. 4, 2010, relates to a method for de-acidizing an acid gas mixture using an absorbent comprising an amine dissolved in a mixture at a first concentration. After absorption of the acid gas, the absorbent forms a concentrated-amine phase, which is separated from the remainder of the absorbent and is introduced into a regeneration unit, whereas the remaining of the absorbent is recycled back into the absorption unit. A series of organic solvents are mentioned as the solvent, together with water and aqueous solutions. Organic solvents are mentioned as preferred solvents. The only exemplified absorbents are MEA in iso-octanol, which spontaneously forms a concentrated amine phase containing MEA and the reaction product of MEA and CO 2 , and an aqueous carbonate solution which forms insoluble bicarbonate on absorption of CO 2 .
[0015] WO 2010/044836 A (LIANG HU) Apr. 22, 2010, relates to a method for de-acidizing an acid gas mixture using an absorbent comprising a carrier phase and an organic phase that is immiscible with the carrier phase. Introduction of an organic solvent as described herein is unwanted, mixed solvent systems add complexity to the systems.
[0016] U.S. Pat. No. 7,541,011 B (LIANG HU) Jun. 2, 2009, relates to a method for separating a gas from a gas mixture, using an absorbent comprising at least one activated agent and at least one solvent. The only exemplified activated absorbent is an aqueous mixture of DEA and potassium carbonate, where the solvent causing the intended phase separation and constituting about 80% of the volume of the absorbent, is unspecified.
[0017] An objective of the present invention is to provide an improved absorbent and an improved method for capturing of CO 2 from a CO 2 containing gas using the absorbent, where the improved absorbents have improved characteristics with regard to the criteria mentioned above, compared with the prior used absorbents, such as exemplified with the MEA reference absorbent. Specifically, it is an object to provide an absorbent having a low energy requirement and good chemical stability. It is also an object to provide a method for use of the new absorbent which makes use of these characteristic and results in low energy consumption with minimal environmental impact. Other objects of the invention will be clear by reading the description.
DISCLOSURE OF INVENTION
[0018] According to a first aspect, the present invention relates to a liquid, aqueous CO2 absorbent comprising two or more amine compounds, where the aqueous solution of amines having absorbed CO2 is not, or only partly miscible with an aqueous solution of amines not having absorbed CO2, where at least one of the amines is a tertiary amine, and where at least one of the amines is a primary and/or a secondary amine, wherein the tertiary amine is DEEA and the primary and/or secondary amine(s) is (are) selected from DAB, DAP, DiAP, DMPDA, HEP, or the tertiary amine is DIPAE, or N-TBDA and primary and/or secondary amine(s) is (are) selected from DAB, DAP, DiAP, DMPDA, HEP, MAPA, and MEA. These combinations of a tertiary and primary and/or secondary amine(s) that are miscible and form a single phase mixture before absorption of CO 2 , have been found spontaneously to separate into a CO 2 rich phase and a CO 2 lean phase after absorption of CO 2 . This phase separation makes it possible to separate the CO 2 rich phase from a CO 2 lean phase for regeneration of the CO 2 rich phase only, and recycle the CO 2 lean to the absorber.
[0019] Regeneration of the amine absorbent comprises heating of the rich absorbent for reversing the exothermal CO 2 absorption to release the CO 2 . Reduction of the volume to be heated during the regeneration reduces the heat demand for heating the absorbent. Even though heat exchanging is extensively used to recover heat and reduce heat loss, the heat loss in the regeneration step is substantial. Reduction of the volume to the heated reduces the heat demand for heating of water and lean amine, and accordingly reduces the heat loss from the total process.
[0020] According to a second aspect, the present invention relates to a method for capturing CO2 from a CO2 rich gaseous, the method comprising the steps of:
introducing the CO2 rich gas into an absorber in which the gas is brought into counter current contact with a liquid, aqueous CO2 absorbent comprising a combination of a tertiary amine and a primary or amine amine, where the tertiary amine is DEEA and the primary and/or secondary amine(s) is (are) selected from DAB, DAP, DiAP, DMPDA, HEP, or the tertiary amine is DIPAE, or N-TBDA and primary and/or secondary amine(s) is (are) selected from DAB, DAP, DiAP, DMPDA, HEP, MAPA, and MEA, to absorb the CO2 in the gas stream to produce a depleted gas stream, releasing the gas stream depleted from CO2 into the surroundings, collecting the absorbent at the bottom of the absorber, allowing the absorbent separate into a CO2 rich absorbent phase, and a CO2 lean absorbent phase: withdrawing the CO2 lean absorbent phase and recycling the lean absorbent phase into the absorber, withdrawing the CO2 rich absorbent phase and introducing the rich absorbent into a stripper column for regeneration of the CO2 rich to release CO2, that is withdrawn and further treated for storage, to give a CO2 lean absorbent that is recycled to the absorber.
[0027] Preferred embodiments of the two aspects of the invention is identified in the dependent claims.
BRIEF DESCRIPTION OF DRAWINGS
[0028] FIG. 1 is a principle drawing of a CO 2 capture plant according to the invention,
[0029] FIG. 2 is an absorption curve for exemplary absorbents according to the present invention, compared with MEA
[0030] FIG. 3 is an absorption curve for other exemplary absorbents according to the invention, compared with MEA,
[0031] FIG. 4 is a plot of CO 2 pressure as a function of temperature,
[0032] FIG. 5 is a plot of heat of reaction for one absorbent system,
[0033] FIG. 6 is a plot of vapour pressure as a function of for some amines in pure form, and
[0034] FIG. 7 shows three plots of activity coefficient (γ i ) as a function of concentration for DIPAE in water at different temperatures.
DETAILED DESCRIPTION OF THE INVENTION
[0035] FIG. 1 is a principle drawing of a plant for CO 2 capture using the absorbent according to the present invention. CO 2 containing gas, such as exhaust gas from a power plant fired by carbonaceous fuel, or any other CO 2 containing gas, is introduced into an optional direct contact cooler 1 through an exhaust line 2 arranged to the lower part of the direct contact cooler. The exhaust gas is cooled and humidified by water introduced through a water distributor 3 , such as nozzles, trays, packing or the like, so that exhaust gas streaming upwards in the cooler is brought in contact with the water. A packing 4 is preferably arranged in the direct contact cooler 1 to improve the contact between the water and the exhaust gas during the counter current flow of water against exhaust gas.
[0036] Cooling water for the direct contact cooler is withdrawn from the bottom of the direct contact cooler and re-circulated in a washing water re-circulation line 5 by means of a pump 6 . A cooler 7 for cooling the washing water against cooling water is preferably arranged in the re-circulation line 5 . The skilled person will understand that non-shown lines for adding make-up water and/or adjusting the pH of the circulating water, preferably are arranged to the re-circulation line.
[0037] Cooled and humidified exhaust gas is withdrawn from the direct contact cooler through a line 8 and a blower 9 and introduced into the lower part of an absorber 10 . The exhaust gas is flowing upwards in the absorber and is caused to flow in counter current contact with a liquid absorbent in a packing 11 . The skilled person will understand that the packing 11 may be any convenient packing allowing or maximizing intimate contact between the exhaust gas and the liquid absorbent. Additionally, the packing may be divided in two or more serially connected parts.
[0038] Absorbent is introduced into the absorber 10 from a lean absorbent line 12 and is distributed to the top of the packing 11 from absorbent distributor 13 , and is allowed to trickle through the packing below to absorb CO 2 from the exhaust gas streaming upwards.
[0039] The absorbent is introduced into the absorber either as a substantially homogenous liquid that may comprise some discontinuous phase that is not or partly miscible with the main liquid phase, or as a bi-phasic aqueous solution containing two CO 2 lean not or partly miscible phases.
[0040] For absorbents that are present in one phase when CO 2 lean, two immiscible phases form in absorbing CO 2 from the exhaust gas, and the rich absorbent phase having absorbed CO 2 becomes immiscible with the CO 2 lean absorbent.
[0041] For absorbents being biphasic when lean in CO 2 , both phases absorb CO 2 . As the total CO 2 content increases, certain components from the CO 2 lean phase transfer to the CO 2 rich phase, thereby producing steadily more CO 2 rich phase while maintaining a high absorption rate throughout the process.
[0042] The exhaust gas leaving the packing 11 is CO 2 depleted as more than 80%, more preferably more than 85%, such as more than 90%, of the CO 2 originally present in the exhaust gas, is absorbed by the absorbent. The CO 2 depleted exhaust gas is then washed in one or more washing section(s) each of which comprising a washing packing 30 in which the CO 2 depleted exhaust gas is washed in counter current flow to water, or an aqueous acid solution to remove any amines and degradation products of amines from the gas.
[0043] Washing water is introduced to the top of the washing section through liquid distributor 31 . Washing water is collected by liquid collector 32 below the washing section and withdrawn through a washing water recycle line 33 . A pump 34 and a cooler 35 are arranged to the recycle line 33 . Not shown make-up water line, and/or pH adjustment line may also be arranged to the recycle line 33 . A demister 36 is preferably arranged above the washing section to remove droplets of water following the cleaned exhaust gas, before the cleaned exhaust gas is released to the surroundings through a cleaned exhaust line 37 .
[0044] The absorbent is collected at the bottom of the absorber and transferred through an absorbent withdrawal line 14 into a separation unit 15 . A pump 16 may be provided in the absorbent withdrawal line 14 .
[0045] The CO 2 rich phase of the absorbent is separated from the CO 2 lean absorbent by means of gravity or other separation in the separation unit 15 , as the CO 2 rich phase is heavier than the CO 2 lean phase. The lightest, or CO 2 lean, phase is withdrawn from the separation unit 15 through a recycle line 17 and re-cycled to the lean absorbent line as a part of the lean absorbent introduced into the absorber. A lean absorbent pump 18 for pumping the lean absorbent, and a cooler 19 for cooling the lean absorbent are preferably arranged on the lean absorbent recycle line 12 .
[0046] The heavy, CO 2 rich phase from the separation unit 15 is withdrawn through a rich absorbent line 20 . The rich absorbent in line 20 is heated in a heat exchanger 21 against lean absorbent in line 12 as described in further details below, and is introduced into a regeneration column 40 via rich absorbent distributor 41 , is caused to flow counter current to steam in a packing 42 arranged in the regeneration column below the distributor 41 , and is collected at the bottom of the regeneration column 40 .
[0047] The CO 2 rich absorbent introduced into the regeneration column is stripped by the counter current flow of steam to release CO 2 that streams upwards together with the steam. The stream of CO 2 and steam flowing upwards in the regeneration column is washed by counter current flow to water in a packing 43 . Washing water is introduced from a water return line 44 into a washing water distribution device 45 . CO 2 and steam that have been washed in the packing 43 are withdrawn from top of the regeneration column and cooled, dried and compressed before the captured CO 2 is withdrawn from the plant through a CO 2 line 46 .
[0048] Cooling, drying and compression are illustrated by means of a cooler 47 , a flash tank 48 and a compressor 49 . The skilled person will, however understand that the final treatment of CO 2 comprises several cooling, flashing and compression steps. Water removed during the drying of the gas phase withdrawn from the regeneration column is, preferably, collected, and returned as washing water in line 44 . A pump 49 is normally provided to recycle the water and pump the water into the washing water distributor 45 .
[0049] Regenerated, or lean absorbent, is withdrawn from the regeneration column through an absorbent drain line 60 and is led into a reboiler 61 heated by a heating coil 62 , normally heated by steam at about 130° C. Steam comprising a mixture of water steam and gaseous amine is withdrawn through a steam line 63 and introduced into the regeneration column as stripping gas to heat and strip the rich amine. Liquid absorbent is withdrawn through lean absorbent line 12 and cooled by heat exchanging against rich absorbent as mentioned above.
[0050] A part stream is preferably withdrawn from the absorbent drain line 60 through a reclaimer line 60 ′ and introduced into a reclaimer 65 where the absorbent is heated by means of a heat coil, preferably by use of steam, and boiled, optionally in presence of additional chemicals such as acids, to liberate insoluble amine salts, to reclaim amines that are withdrawn as gas together with steam through a reclaimed absorbent line 67 . The gas in the reclaimed absorbent line 67 is introduced into the regeneration column as stripper gas, whereas remaining liquid phase is withdrawn from the reclaimer 65 together with insoluble salts and degradation products through a waste absorbent line 68 and sent for deposition or degradation to more environmentally acceptable products.
[0051] The skilled person will understand that the liquid distributor 3 , 13 , 31 , 41 , 45 may be any convenient liquid distributor such as nozzle tubes, trays etc.
[0052] The separation unit 15 may in its simplest embodiment be a settling tank but can also be a centrifugal separator such as a cyclone or a centrifuge, to accelerate the separation.
[0053] The present absorbent is an aqueous solution of two or more absorbing amine compounds, as defined in the claims. Before absorption of CO 2 , i.e. in the lean, or CO 2 poor state, the absorbent may be a substantial homogeneous aqueous solution, or may comprise two immiscible or partly miscible aqueous phases. After having absorbed CO 2 , the absorbent spontaneously separates into two immiscible phases, one phase mainly comprising lean absorbent, i.e. absorbent not having absorbed CO 2 , and one phase mainly comprising rich absorbent, i.e. absorbent having absorbed CO 2 . Both phases are still aqueous solutions.
[0054] When the aqueous absorbent is brought in contact with CO 2 , CO 2 is absorbed physically, chemically or by a combination thereof in an exothermal reaction to alter the composition of the absorbent. The absorbent according to the present invention spontaneously forms two partly miscible or immiscible phases on absorption of CO 2 , one CO 2 lean phase and one CO 2 rich phase.
[0055] For a substantially homogeneous solvent entering the absorber, the separation into two phases starts during the absorption phase, i.e. when the absorbent is in contact with gaseous CO 2 in the absorber. The CO 2 lean phase works here as a reaction reservoir and enhancer for the CO 2 absorption, whereas the CO 2 rich phase accumulates CO 2 up to a very high loading by steadily receiving absorbing components from the CO 2 lean phase. The volume ratio of CO 2 lean to CO 2 rich phase will thus decrease as the CO 2 content increases. If the liquid feed to the absorber already contains two immiscible or partly miscible phases, the working mechanism is exactly the same.
[0056] The phases differ in density, where the CO 2 rich phase is heavier than the CO 2 lean phase, allowing the phases to be separated by density, such as e.g. in a settling tank. The spontaneous separation in the separator is relatively quick and efficient. If necessary, the separation may be accelerated by means of centrifugal separators, or other gravity enhancing means.
[0057] By separating the phases and returning the CO 2 lean absorbent directly to the absorber, and regenerating only the rich absorbent, i.e. the absorbent having absorbed most CO 2 , less absorbent has to be heated. Accordingly, the above mentioned sensible heat demand for the regeneration is substantially reduced. As the sensible heat loss for heating up the circulation phase to the desorber outlet temperature is lowered in proportion to the reduction in flow, the present invention let us to reduce energy consumption for the CO2-stripping step. At the same time, circulation of CO 2 -lean phase directly to the absorption unit provides good wetting of the gas-liquid contact surface inside the absorption unit, thus providing high absorption rate and effective gas-liquid mass-transfer.
[0058] CO2-rich phase is the only phase sent to the regeneration unit. In the desorption unit CO2-rich phase is heated up to the stripping conditions, when absorbed CO2 is regenerated from the CO2-rich solution. Sending only CO2-rich phase to the CO2-stripping step allows the highly concentrated solution to be regenerated alone. Heating this solution up to normal stripping temperatures of 115-125° C. provides CO 2 partial pressures greatly exceeding those encountered under normal operation with e.g. MEA. This reduces the heat needed for stripping steam generation to a small fraction of that normally needed for e.g. MEA. The heat needed for stripping steam is normally a substantial part of the total heat demand, e.g. 40%, and this may be lowered to close zero.
[0059] The absorbent systems developed are all systems containing two or more absorbent components. One of the absorbent components will be an active component proving the high absorption rate needed for obtaining a close approach to equilibrium at the absorber outlet (bottom). Another component will provide the CO 2 loading capacity while transferring from the CO 2 lean phase to the CO 2 rich phase during absorption. This absorbent component may have a low heat of reaction, and will thus provide a reduction in heat needed for reversion of the CO 2 absorption reaction in the regenerator, while the active component still maintains the absorption rates in the absorber. This property allows also a reduction in the heat of reaction reversion compared to what is found e.g. for MEA.
[0060] Another way of exploiting the properties of the developed absorbent systems is to perform the regeneration at reduced temperature. The developed absorbent systems provide a high partial pressure of CO 2 even at temperatures down to 80-90° C. These allow regeneration at these and possibly even lower temperatures. Regeneration at 80-90° C. opens up a possibility for use of waste heat or externally generated heat, e.g. solar heat, for regeneration and may thus lead to processes without a need for heat extraction from the power production process
[0061] The behaviour of the absorbents depends on the choice of CO 2 absorbing species, the ratio between the species and the total concentration thereof.
[0062] Even though it is expected that a plurality of absorbent mixtures may separate spontaneously into a CO 2 lean phase and a CO 2 rich phase, the studies leading to the present invention have identified a limited number of preferred absorbents.
[0063] Table 1, below, identifies the amines used in the present studies, the common abbreviation, molecular weight and CAS No., for each of them:
[0000]
TABLE 1
Chemical name
Abbreviation
MW
CAS No.
1,4-diaminobutane
DAB
88.15
110-60-1
1,3-diamino-2-propanol
DAP
90.12
616-29-5
2-diethylamino-ethanol
DEEA
117.19
100-37-8
1,3-propanediamine
DiAP
74.12
109-76-2
2-diisopropylamino-ethanol
DIPAE
145.24
96-80-0
2,2-dimethyl-1,3-propanediamine
DMPDA
102.18
7328-91-8
1-piperazineethanol
HEP
130.19
103-76-4
N1-methyl-1,3-Propanediamine
MAPA
88.15
6291-84-5
2-amino-ethanol
MEA
61.08
141-43-5
N-tert-butyldiethanolamine
N-TBDEA
161.24
2160-93-2
[0064] The present absorbents are aqueous solutions of two or more CO 2 of the amines mentioned above. Table 2, below, shows the tested absorbents:
[0000]
TABLE 2
Absorbent
No.
Constituents
Ratio
Comment
System 3
DIPAE/MAPA
4:2
Single phase before CO2
absorption, two liquid
phases after absorption
System 4
DEEA/MEA
4:2
Two liquid phases before
and after absorption
System 6
DIPAE/DiAP
3:1
Two liquid phases before
and after absorption
System 7
DIPAE/MEA
4:2
Two liquid phases before
and after absorption
System 8
DIPAE/DiAP
4:2
Two liquid phases before
and after absorption
System 9
DIPAE/DAB
4:2
Single phase before CO2
absorption, two liquid
phases after absorption
System 10
DIPAE/MAPA
1:1
Two liquid phases before
and after absorption
System 10b
DIPAE/MAPA
2:1
Two liquid phases before
and after absorption
System 11
T-TBDEA/MAPA
4:2
Two liquid phases before
and after absorption
System 12
N-TBDEA/DiAP
4:2
Single phase before CO2
absorption, two liquid
phases after absorption
System 21
DIPAE/HEP
4:1
Two liquid phases before
and after absorption
System 22
DEEA/DMPDA
5:2
Single phase before CO2
absorption, two liquid
phases after absorption
[0065] 30% MEA was used as a reference absorbent in the examples.
EXAMPLES
Example 1
Systems Showing One Liquid Phase Before Absorption and Two Liquid Phases after Absorption
[0066] CO 2 loading and CO 2 absorption rate at 40° C. were measured according to standard procedures for different absorbent mixtures according to the present invention and for 30% MEA, and absorption curves were plotted. The standard measuring procedure for CO 2 is by precipitation of barium carbonate (BaCO 3 ) using addition of 0.5 M barium chloride (BaCl 2 ) and 0.1 M sodium hydroxide (NaOH).
[0067] FIG. 2 illustrates absorption curves for MEA and the absorbents mainly comprising one phase in CO 2 lean condition. We see that the rate of absorption in the low loading range is better that for MEA and that this is retained to high CO 2 loadings. It should be noted that the CO 2 loading is given based on kg mixed solution and that the CO 2 rich phase will be 2-4 times more concentrated.
Example 2
Systems Showing Two Liquid Phases Before Absorption and Two Liquid Phases after Absorption
[0068] CO 2 loading and CO 2 absorption rate at 40° C. were measured according to standard procedures (see below]) for different absorbent mixtures according to the present invention and for 30% MEA, and absorption curves were plotted
[0069] FIG. 3 illustrates absorption curves for absorbents that comprises two phases both when being CO 2 lean and after CO 2 absorption. Also in this case the CO 2 loading is per kg of solvent and several of the systems have higher or equally high absorption rate compared to 30% MEA.
[0070] What happens during absorption is the same whether one starts with one or two liquid phases. As soon as two liquid phases are formed most of the CO 2 will accumulate in the ionic bottom phase. The upper phase will act as a reservoir for tertiary amine, and this will transfer to the lower phase as it loads up.
Example 3
Stripping Pressure for DIPAE:MAPA, 4:2
[0071] The CO 2 partial pressure over CO 2 rich absorbent bottom phase as a function of temperature was measured. CO 2 partial pressure over the rich phase of “system 3 ” absorbent as a function of temperature is plotted in FIG. 4 .
[0072] FIG. 4 clearly shows that the tested absorbent allows stripping at elevated pressures, thus reducing energy consumption for the further CO 2 compression and pipeline transportation steps.
Example 4
Heat of Desorption for DIPAE:MAPA, 4:2
[0073] Heat of desorption at the stripping of the CO2-rich phase lies in the low heat of reaction region, thus reducing amount of energy required for the CO 2 -stripping step. It allows working in the region of optimal loading, remaining in the region of low heat of reaction, obtaining higher energy efficiency of whole process. As shown in FIG. 5 “Heat of reaction for System 3 ”, this region lies in the loading range from 0.4 to 1 mol CO 2 /mol of amine.
Example 5
Cyclic Capacity for DIPAE:MAPA, 4:2
[0074] CO 2 -rich phase after the CO 2 -stripping step becomes regenerated CO 2 -rich phase. Regenerated CO 2 -rich phase is sent back to the absorption unit. And so, the process is cycled.
[0075] The desorbed CO 2 gas is either collected or sent to the customer pipeline.
[0076] The purified gas-mixture is collected or disposed of depending on the purpose of the user.
[0077] Absorbent system 3 was tested for CO 2 loading per mol of amine in the absorbent. It was found that the CO 2 lean, or lower phase, has a loading of 0.014 mol CO 2 /mol amine, whereas the CO 2 rich or lower phase has a loading of 1.49 mol CO 2 per mol amine. An absorption capacity of close to 1.5 mol CO 2 per mol of amine is a high cyclic capacity of absorbent.
Experiment 6
Vapour Pressure Over Amines at Varying Temperature
[0078] Vapour pressure of the secondary amine DIAP, and the tertiary amine N-TBDEA were measured as a function of temperature and potted in FIG. 6 . The data points are measured values, whereas the lines are calculated values. Values for MDEA which is not a part of the present invention, is also included for comparison.
[0079] FIG. 6 clearly shows that the vapour pressure of DIAP increases substantially from the typical value found in an absorber of a CO 2 capture plant, to the temperature typically found in the regeneration column. As a result of this substantial difference, the vapour pressure of DIAP in the absorption column will be relatively low, resulting in a relatively low amine partial pressure, whereas the amine (DIAP) partial pressure will be substantially higher in the regeneration column, a fact that will result in that the DIAP will constitute a substantial part of the stripping gas in the regeneration column. As the heat of evaporation of DIAP is substantially lower than for water, this will reduce the regeneration heat needed for the regeneration.
[0080] As the partial pressure in the absorber is low, the problems with amine slip, i.e. loss of amine together with the cleaned exhaust gas, will be low under normal circumstances.
Example 7
Activity Coefficient for DIPAE at Different Temperatures
[0081] The reactivity coefficient of DIAP, as a typical example of a primary or secondary amine according to the present invention, in aqueous solution. The concentration of amine is in FIG. 7 plotted against the activity coefficient, at temperatures of 70, 80 and 100° C. Circles indicate measured points, whereas the lines indicate calculated values.
[0082] The results indicates that DIAP, as a representative for the amines used in the claimed process have the property of very low activity coefficient at low concentrations, as shown in FIG. 7 . This is a large advantage as one may operate with amine with higher pure amine vapour pressure and still have a low actual vapour pressure in the absorber, thus making the avoidance of amine vapour out of the absorber easier to handle. The claimed amine systems also have the property of increasing activity coefficient with temperature. This implies that the effect of replacing water as “stripping steam” in the regenerator while still maintaining low actual vapour pressure in the absorber can be achieved with these systems.
Discussion
[0083] Separation of rich and lean absorbent allows for sending the rich absorbent only to regeneration, which again results in lower circulation rate for the CO 2 -rich phase, thus obtaining reduced energy consumption for the pumping operation.
[0084] It was found that two-phase forming absorbents are showing high absorption rate, lower heat of absorption, higher CO 2 pressure at the desorption stage and thus lower energy demand for whole process.
[0085] Screening results for exemplary absorbents, or absorption systems, are provided, indicating promising properties and potential for obtaining advantageous results for a carbon capture plant.
[0086] The test results also give indications of equilibrium and absorption rates, compared to 30% weight MEA.
[0087] The provided analysis of CO 2 -content for the two phases obtained after CO 2 capture clearly shows a high CO 2 concentration in the rich phase compared to concentration reached in ordinary single phase absorption. This property allows for high CO 2 capture capacity at the same time as the amount of rich absorbent circulated through the regeneration column is reduced. Reduction of the volume of absorbent circulated through the regeneration column reduces the heat demand for heating the rich absorbent in the regeneration column.
[0088] The plot of total pressure over the rich solution as function of temperature shows a CO 2 pressure of about 7 bars can be obtained at 105° C. or nearly 4 bars at 80° C. By obtaining CO 2 at an elevated pressure from the regeneration column, the energy input needed for compressing the captured CO 2 before being exported from the capture plant is substantially reduced.
[0089] Using a lower regenerator temperature of 80° C. could allow the use of waste or externally generated heat, alleviating the need for steam extraction from a power station.
[0090] The plot of the values for heat of reaction for absorbent system 3 found in FIG. 5 , shows advantageous heat of reaction properties. A sudden drop in the heat of reaction drops to values typical of tertiary amines is observed after starting at high values typical for primary and secondary amines at low loadings. The present absorbent systems, as illustrated by system 3 , have therefore a surprisingly low heat of reaction in the region for industrial operation of a carbon capture plant.
[0091] The screening results show that the system maintains its rate of absorption to quite high loading implying that, even if at higher loading it is the tertiary amine that reacts, the rate of absorption is more like a secondary or primary amine. Thus it may seem that we can have the speed of a secondary or primary amine, combined with the heat of absorption of a tertiary amine. | A liquid, aqueous CO 2 absorbent comprising two or more amine compounds, where the aqueous solution of amines having absorbed CO 2 is not, or only partly miscible with an aqueous solution of amines not having absorbed CO 2 , where at least one of the amines is a tertiary amine, and where at least one of the amines is a primary and/or a secondary amine, wherein the tertiary amine is DEEA and the primary and/or secondary amine(s) is (are) selected from DAB, DAP, DiAP, DMPDA, HEP, or the tertiary amine is DIPAE, or N-TBDEA and primary and/or secondary amine(s) is (are) selected from DAB, DAP, DiAP, DMPDA, HEP, MAPA, and MEA, and a method for CO 2 capture using the CO 2 absorbent, are described. | 8 |
This is a continuation application of U.S. patent application Ser. No. 09/939,653, filed on Aug. 28, 2001, now U.S. Pat. No. 6,687,184, issued on Feb. 03, 2004, the disclosure of which is incorporated by reference herein.
FIELD OF THE INVENTION
The present invention relates generally to memory devices, and more particularly, to a memory device having a selectable clock input.
BACKGROUND OF THE INVENTION
Memory devices such as Dynamic Random Access Memories (DRAM) and Synchronous Dynamic Random Access Memories (SDRAM) are regularly used in computing systems for applications ranging from video games to personal computers.
An SDRAM usually includes components such as memory arrays, row and column decoders, and control logic. Additionally, an SDRAM typically includes a mode register for setting an operation mode so that the SDRAM can perform various functions that are optimally selected for the system containing the SDRAM. The mode register may allow external setting of operation modes; that is, it may have its set values changed in response to an externally supplied signal. An external clock signal is also used for memory devices to synchronize the operation of the memory device with other components of the computing system.
The computing systems within which SDRAMs function usually operate with a predetermined clock input which can be a single clock input or a differential clock input. While a differential clock input system may be preferable for characteristics such as low noise, some point to point systems exist where a single clock input is preferred.
To accommodate a single clock input system and a differential clock input system, SDRAMs have to be selected according to, among other features, whether or not the SDRAM's components can accommodate the clock in the system with which the SDRAM is to be used. This need for multiple types of SDRAMs imposes not only additional manufacturing costs to produce different types of SDRAMs for various systems, but also storage, distribution, and other logistical costs.
What is needed is a memory device capable of accommodating more than one clock input system, for example, a single clock input system and a differential clock input system.
SUMMARY OF THE INVENTION
The shortcomings discussed above are largely overcome by the present invention which in one aspect provides a synchronous memory device with a mode register having a user selectable bit, the state of which internally configures the memory device to operate with either a single clock input or a differential clock input.
In another aspect, the present invention provides a memory device which has a mode register in its control logic which has a user selectable bit position which can be set to enable the control logic to appropriately control the operation of the memory device with different types of applied clock input signals.
In another aspect, the present invention provides a method for operating a memory system by providing a memory controller and a memory device having a mode register, initializing the memory system to operate with a first clock input signal by sending a signal from the memory controller to the mode register setting the memory device to operate at the first clock input signal, and changing the memory system to operate at a second clock input signal by sending a signal from the memory controller to the mode register to operate the memory device at the second clock input signal, wherein the second clock input signal is different from the first clock input signal.
These and other features and advantages of the present invention will be more clearly apparent from the detailed description which is provided in connection with accompanying drawings which illustrate exemplary embodiments of the invention.
BRIEF DESCRIPTION OF THE DRAWINGS
FIG. 1 is a diagram of a portion of an SDRAM in accordance with an embodiment of the present invention;
FIG. 2 is a diagram of a computer and memory system using the SDRAM illustrated in FIG. 1 ;
FIG. 3 is a diagram of a control bus which may be used with the SDRAM illustrated in FIG. 1 ;
FIG. 4 is a diagram of a clock input;
FIG. 5 is a diagram of a mode register employed in the SDRAM shown in FIG. 1 ; and
FIG. 6 is diagram of another computer system in accordance with an embodiment of the present invention.
DETAILED DESCRIPTION OF THE INVENTION
Referring now to the drawings, where like parts are designated by like reference numbers throughout, there is shown in FIG. 1 a simplified block diagram of an SDRAM 10 in accordance with an embodiment of the present invention. Although the term SDRAM is used throughout this specification, the present invention is applicable to any DRAM technology which uses a clock, and for use in any computing system such as a game, a video card, and a computer system.
The SDRAM 10 has a control logic 20 that contains a mode register 22 and a command decoder 24 . The SDRAM 10 also has a memory array 30 , a row decoder 32 and a column decoder 34 , and an address register 36 . Multiple memory arrays 30 may be provided in the SDRAM 10 , along with multiple row decoders 32 and column decoders 34 . A row address multiplexer 38 , a column address counter/latch 37 , and read/write data path components are also provided within the SDRAM 10 . The SDRAM 10 interfaces with external components through a control bus 50 , an address bus 52 , and a data bus 54 .
The SDRAM 10 may be used as part of a memory system 51 which in turn is used in a computing system, such as computer system 61 shown in FIG. 2 . The computer system 61 , which may employ multiple SDRAMs 10 , has a CPU 60 and a memory controller 64 which is part of memory system 51 . Alternatively, the CPU 60 may provide the memory controller functions. The CPU 60 and the memory controller 64 communicate via a local bus 62 . The memory controller 64 , in turn, communicates with the SDRAM(s) 10 via the control bus 50 , address bus 52 , and data bus 54 . As illustrated in FIG. 3 , the control bus 50 may include multiple signal lines, including a row address strobe line RAS#, a clock enable line CKE, a chip select line CS#, a write enable line WE#, and a column address strobe line CAS#.
The control bus 50 also includes a clock signal line CK, and may include a complimentary clock signal line CK#. In a single clock input system only the CK signal would be present, while in a differential clock input system both the CK and CK# signals would be present. Clock signals CK 72 and CK# 70 are graphically represented in FIG. 4 . The SDRAM 10 synchronizes the output of read data with the rising edges 74 and falling edges 76 of a single clock input system, and with the crossing points 78 of a differential clock input system. Differential clock input systems are also known as double data rate systems. The clock signals are typically generated by a device such as an oscillator, which can be located in a processor, in a memory controller, or anywhere else in a computer system.
In a typical operation of the SDRAM 10 , row address and column address signals are asserted by the memory controller 64 on the address bus 52 , and latched into the address register 36 . The row address signals are then supplied to the row address multiplexer 38 which transmits the row address signal to the row decoder 32 , which appropriately accesses a row of the memory array 30 . The column address signals are supplied from the address register 36 to the column address counter/latch 37 which transmits the column address to the column decoder 34 , which appropriately accesses a column of the memory array 30 . As stated above, if the SDRAM contains multiple memory arrays 30 , multiple row decoders 32 and column decoders 34 would likewise be provided.
The memory array 30 is coupled to the data bus 54 via read/write data path circuitry 35 . The read data path portion of the read/write data path circuitry 35 comprises circuits which store output addressed data and ensures that the proper signal levels are delivered to the data bus 54 . The write data path portion of the read/write data path circuitry 35 comprises circuits which accept write data from the data bus 54 , hold data to be written, and drive the write data to the addressed areas of memory array 30 .
Read and write accesses to the SDRAM 10 are burst oriented, where the burst length determines the maximum number of column locations that can be accessed for a given read or write command. In order to write data, the memory controller 64 asserts a write command on the control bus 50 and subsequently supplies write data to the SDRAM 10 via the data bus 54 . In order to read data, the memory controller 64 asserts a read command on the control bus 50 while simultaneously asserting column and row addresses on the address bus 52 . The preceding is a cursory description of the SDRAM's 10 operation; the operation may involve numerous additional well known steps involving known components, the descriptions of which are not provided herein for the sake of brevity.
The overall operation of the SDRAM 10 is controlled by the control logic 20 which includes the command decoder 24 and the mode register 22 . The command decoder 24 interprets various signal combinations present on the control bus 50 as high level commands asserted by the memory controller 64 , thereby allowing the control logic 20 to carry out internal operations of the SDRAM 10 by implementing the asserted commands. The operation of the control logic 20 is further defined by the settings of the mode register 22 , which is loaded with values which control various SDRAM operational parameters.
The mode register 22 has bit positions which are used to define specific modes of operation of the SDRAM 10 . Binary values are set in the mode register 22 by the memory controller 64 . Typical operational states which can be set by binary values set in the mode register 22 include, for example, the selection of a burst length, a burst type, and a CAS latency. The mode register 22 is typically programmed by a command from the memory controller 64 at initialization of the computer system 61 , and will retain the stored information until it is programmed again or the SDRAM 10 loses power. Reprogramming the mode register 22 usually does not change the stored contents of the memory array(s) 30 .
The mode register 22 of an SDRAM constructed in accordance with an embodiment of the present invention is illustrated in FIG. 5 . The mode register 22 has selectable bits A 0 –A 10 , BA 0 , and BA 1 used to define the various modes of operation discussed above. Bit A 0 defines the enable or disable state of a delay lock loop used to synchronize initial memory operations, bit A 1 defines the drive strength for all outputs as normal or reduced, and bits A 2 –A 10 define various operating modes such as load mode register, read, or write. Alternatively, bits A 0 –A 2 may be used to define the burst length, bit A 3 may be used to define the burst type, bits A 4 –A 6 may be used to define the CAS latency, and bits A 7 –A 10 may be used to define the operating mode such as normal or reset operation. Although the mode register 22 illustrated in FIG. 5 contains multiple bits and sections, including an extended mode register section, the mode register 22 in accordance with the present invention need not incorporate all those sections. These combinations and operations of mode register bits are illustrative only and are not meant to be restrictive in order to practice the present invention.
A unique feature of mode register 22 in an SDRAM of the present invention is that a selectable bit may be used to define whether or not the control logic, and therefore the SDRAM 10 , will operate in a single clock input mode or a differential clock input mode. For the exemplary mode register 22 illustrated in FIG. 5 , mode register bit A 10 can be set to 0 to enable the control logic 20 to operate the SDRAM 10 with a single clock input, or set to 1 to enable the control logic 20 to operate the SDRAM 10 within a differential clock input. As discussed above, the SDRAM 10 synchronizes the output of read data with the rising edges 74 and falling edges 76 of a single clock input system, and with the crossing point 78 of a differential clock input system. Either a differential clock input or a single clock input can be the default setting for the mode register 22 . Although bit A 10 controls the clock input signal setting in the illustrated mode register 22 , any bit may be used for this function.
The mode register 22 bit controlling the clock signal input setting for the operation of the SDRAM 10 is usually set at initialization of the computer system 61 to operate in agreement with other components of the system. Alternatively, the mode register 22 can be switched to operate between different types of clock inputs after initialization of the computer system 61 . For example, the computer system 61 may switch from operating at differential clock input to operating at a single clock input when switching from a regular mode to a power savings mode, or from a regular mode to a test mode. During a power savings mode, it may be advantageous to shut down several components of computer system 61 , but to retain the memory stored in the SDRAM 10 . For this purpose, a signal may be sent to the memory controller 64 to set the mode register 22 , and thereby the control logic 20 , to operate at a single clock input, thereby decreasing the amount of power consumed by the computer system 61 and SDRAM memory device. When the computer system 61 is to return to a normal operating mode, a signal would be sent to the memory controller 64 to reset the mode register 22 and control logic 20 to operate with a differential clock input system.
FIG. 6 illustrates an example of a computer system 80 that may incorporate an SDRAM 10 containing a mode register 22 in accordance with the present invention. The system 80 has a memory circuit 82 including an SDRAM 10 constructed in accordance with the present invention. The computer system 80 includes a central processing unit (CPU) 84 for performing computer functions, such as executing software to perform desired tasks and calculations. One or more input/output devices 86 , 88 , such as a keypad or a mouse, are coupled to the CPU 84 and allow an operator to manually input data thereto or to display or otherwise output data generated by the CPU 84 . One or more peripheral devices such as a floppy disk drive 90 or a CD ROM drive 92 may also be coupled to the CPU 84 . The computer system 80 also includes a bus 94 that couples the input/output devices 86 , 88 and the memory circuit 82 to the CPU 84 .
Thus, the present invention provides a mode register 22 that can enable one SDRAM 10 to operate with both single clock and differential clock input systems. This reduces the need to stock multiple types of SDRAMs, thereby reducing costs associated with manufacturing and stocking multiple types of components. Additionally, the mode register 22 in accordance with the present invention allows for the SDRAM 10 to operate in a computing system designed to switch between differential clock and single clock input signals.
While the foregoing has described in detail preferred embodiments known at the time, it should be readily understood that the invention is not limited to the disclosed embodiments. For example, although the invention has been described with respect to switching SDRAM operation between a single clock input or a differential clock input, it should be apparent that the invention can also be implemented with a suitable mode register input to select among any two or more different types of clock inputs. In addition, the invention can be modified to incorporate any number of variations, alterations, substitutions or equivalent arrangements not heretofore described, but which are commensurate with the spirit and scope of the invention. Accordingly, the invention is not limited to the embodiment specifically described but is only limited by the scope of the appended claims. | A memory device having a mode register with a selectable bit which sets the memory device to operate with a selected one of a plurality of possible clock input signals, for example, a single clock input or differential clock input. | 6 |
SPECIFIC REFERENCE
[0001] The present application claims benefit of priority date so established by provisional application serial No. 60/335,630, filed Oct. 31, 2001.
BACKGROUND
[0002] 1. Field of the invention
[0003] The present invention relates generally to methods for detecting mutations in the galactose-1-phosphate uridyl transferase (GALT) gene. In particular, a set of methods are disclosed for genotyping specimens to determine their status (wild type or mutant) at five loci, each having a particular melting peak as they are subjected to melting curve analysis.
[0004] 2. Description of the Related Art
[0005] Galactosemia is a standard component of most newborn metabolic screening programs. The classical form of galactosemia is caused by mutations in the galactose-1-phosphate uridyl-transferase (GALT) gene. Screening for galactosemia is achieved through analysis of total galactose (galactose and galactose-1-phosphate) and determining the activity of the GALT enzyme. This approach is effective, but environmental factors, specimen processing procedures, and the high frequency of the Duarte variant (N314D) necessitates further analysis to reduce false positive results.
[0006] Prospective screening of newborns for galactosemia is a routine procedure in the United States and many foreign countries. Screening utilizes the universally collected Guthrie dried blood card specimen (DBS) to assay for total galactose (galactose plus glactose-1-phosphate), and the activity of the galactose-1-phosphate uridyl transferase (GALT) enzyme. Total galactose is typically assayed for using NAD reduction analysis while GALT activity is determined using the Beutler assay.
[0007] Classical galactosemia results from mutations to the GALT gene, which cause severe perturbation in the activity of the corresponding enzyme. The GALT gene has been characterized and numerous mutations have been identified. Biochemical analysis for galactose and GALT activity are sound principle methods to prospectively assay newborns for galactosemia, however complicating factors can interfere with these results, necessitating further analysis.
[0008] It is commonly observed in newborn screening laboratories that environmental factors and sample collection/handling procedures, practiced at the site of specimen collection, may have severe adverse effects upon GALT activity, thereby causing abnormally low results in the Beutler assay. The most notable environmental influences upon GALT activity are heat and humidity. Specimens collected during hot, humid summer months, or in climates where such conditions are persistent, often present with reduced GALT activity in the Beutler assay. The practice of batching, where dried blood spot (DBS) specimens are permitted to accumulate before being mailed to the screening lab, also adversely affects GALT activity. Enzyme activity deteriorates over time, which minimizes the optimum time period between specimen collection and analysis. In addition steps must be taken to avoid the specimen's exposure to heat and humidity, which are the best practices to ensure optimal performance in the Beutler assay.
[0009] Additionally, reasons inherent to the screening process itself and the nature of mutations in the GALT gene necessitate analysis beyond the biochemical regimen. A false negative result may cause, at the minimum, serious medical consequences and, in a worse case scenario, death. Comparatively, a false positive result may lead to parental anxiety, mistrust of the screening process, and unnecessary medical procedures. To balance these concerns, screening labs require that critical result values fall within a range where false negative results are eliminated and false positive results are minimized.
[0010] The Duarte variant (N314D), carried by upwards of 5% of the general population, causes a partial loss (˜25%) of GALT activity. The high frequency of the Duarte variant is yet another complicating factor-in galactosemia screening.
[0011] Supplementing biochemical data using mutational analysis is a powerful method to reduce false positive results and may be used to provide unambiguous confirmation of true positive results. For example, a 2-tiered approach, biochemical analysis followed by gene-level analysis, is the standard employed by most newborn screening laboratories in their cystic fibrosis screening programs. Primary screening for cystic fibrosis is performed by analysis of circulating trypsinogen and those specimens having elevated trypsinogen are subsequently assayed for the CFTR Δ508 mutation. Delta F508 accounts for approximatelv 70% of CFTR mutations worldwide. The addition of Δ508 analysis has dramatically reduced the false positive rate in cystic fibrosis screening. A similar approach, as described herein, increases specificity in galactosemia screening.
[0012] Barriers to gene-level analysis in the screening lab include complexity and turnover time. Traditional methods for genetic analysis such as DNA sequencing, allele specific cleavage, and allele specific oligonucleotide hybridization are time consuming and labor intensive, thus limiting their usefulness in a high throughput laboratory. A recently developed platform dubbed the Lightcycler® eliminates essentially all issues of complexity, turnover time, and labor intensity encountered with classical methods of mutation analysis. The Lightcycler® utilizes rapid air driven thermal cycling and in-line fluorescence analysis of hybridization probes to generate melting curves, which are subsequently used to generate melting peaks for genotype assignment.
[0013] DNA melts at a defined temperature (T m ), wherein T m is defined as the temperature at which half of the double helical structure is lost. This is generally the principle as known in the art supporting the Lightcycler®, since the melting temperature of a DNA molecule is dependent upon its nucleotide composition. DNA molecules rich in GC base pairs have a higher Tm than those having an abundance of AT base pairs. The Lightcycler® provides an innovative solution for identifying the base composition of a PCR amplified product, and in the present embodiment, allows for a qualitative method to assay for galactosemia-causing mutations.
SUMMARY
[0014] Light Cycler technology and fluorescent-labeled hybridization probes are employed and a 5-mutation panel is described which includes the 4 most frequently encountered classical galactosemia alleles (Q188R, S135L, K285N, L195P) and the Duarte N314D variant. Five assays are performed simultaneously under a common set of conditions for both thermal cycling and melting curve analysis. Including DNA preparation, set-up, amplification, and analysis, the entire process requires less than 2 hours. These assays are useful to reduce false positive results, confirm classical galactosemia, and differentiate classical galactosemia from Duarte/Galactosemia (D/G) compound heterozygotes. These assays, owing to their speed and efficacy, are ideal for utilization in a high-throughput newborn screening laboratory.
[0015] Using the presented methodologies for melting curve analysis of galactosemia-causing mutations, genotype data is generated in minutes, as opposed to hours or even days required when using traditional methods. A second advantage to this platform is that it is a “closed tube” assay where both amplification and analysis are performed in a common reaction vessel. Unified amplification and analysis allows for simplified sample tracking and greatly reduces the likelihood of amplicon contamination in the laboratory.
[0016] Accordingly, what is provided is a method for detecting specific galactosemia-causing mutations in the GALT gene, comprising amplifying a portion of the GALT gene from isolated DNA, wherein said portion potentially contains the galactosemia-causing mutation, and thereby forming an amplification product; allowing a pair of labeled probes to hybridize to one strand of the amplification product, wherein one of the probes spans the allele of interest and can match to either the mutant or wild type allele and another of the labeled probes hybridizes to an adjacent sequence, thereby forming hybrids. The hybridized probes bring the donor fluorophore and acceptor fluorophore into close proximity allowing a fluorescent signal to be generated when the appropriate wavelength of light is provided. This fluorescent signal is used to generate melting curves. Genotype is assigned based on the T m of the disassociated hybrid that forms the peak. The galactosemia-causing mutations include the four most frequently encountered classical galactosemia alleles (Q188R, S135L, K285N, L195P) and the Duarte N314D variant. Thus, the method further comprises the step of comparing the resulting melting curves to reference sample curves of samples characterized to contain the above mutations, wherein the reference sample curves indicate a temperature change, ΔT m , between mutant and wild type peaks.
BRIEF DESCRIPTION OF THE DRAWINGS
[0017] [0017]FIG. 1 shows the portion of the sequence for each allele with the SNP, and the sequences of the detection, anchor probes used for hybridization, and the location of fluorescent moieties.
[0018] [0018]FIG. 2 shows the results of the melting peaks for each allele after simultaneous analysis. Melting peaks are well-separated, thereby facilitating unambiguous genotype assignment for each loci.
[0019] FIGS. 3 A-E display the resulting melting peaks and acquired fluorescence for the N314D, Q188R, S135L, K285N, and L195P assays respectively.
DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENT
[0020] The mutations represented in the panel described herein represent the 4 most frequently encountered classical galactosemia mutations observed in the general United States population. Q188R is the most frequently encountered mutation representing approximately 70% of classical galactosemia alleles. The S135L mutation is most frequently observed among African Americans and is the second most frequently encountered allele. K285N is common in those of eastern European descent while L195P represents approximately 2% of classical galactosemia alleles. The Duarte variant, N314D, is present in approximately 5% of the US population and is probably the individually most complicating factor in screening for galactosemia. The so-called D/G compound heterozygotes (where a 314D allele is paired with a classical galactosemia mutation) may display both elevated total galactose and reduced GALT activity effectively mimicking classical galactosemia.
[0021] As used herein, “GALT” refers to the enzyme galactose-1-phosphate uridyltransferase, and “galactosemia” is the deficiency in the activity of the GALT enzyme. Screening for galactosemia is thus achieved through analysis of total galactose (galactose and galactose-1-phosphate) and determining the activity of the GALT enzyme.
[0022] For patient and/or reference specimen preparation, DNA samples are collected from any traditional methods, such as from any tissue or organ from which DNA can be amplified, or by purification from a dried blood spot on filter paper. “Reference specimens” as used herein, are previously characterized DNA specimens containing the mutations of interest. “Patient specimens” are the routinely collected DNA specimens that are to be screened and compared to results obtained from the reference specimens to determine a normal, mutant, or heterozygote sample.
[0023] The sequence of the human GALT gene (Genbank accession number M96264) is the basis for primer and probe design. A portion containing intron 4-exon 10 of the human GALT gene having the potential mutations or complementary positions is set forth in SEQ ID NO: 1 and is nucleotide region (1337-3193) of the above human GALT gene sequence.
[0024] A “primer” as used herein is a short piece of artificially made DNA complementary to a given DNA sequence and which acts as the initiation point from which replication proceeds via polymerase chain reaction (PCR). A “probe” is a fluorescent-labeled synthetic strand of DNA that anneals or “hybridizes” to a complementary DNA sequence generated by PCR. A “detection probe” hybridizes with a sequence that includes the site of the mutation and an “anchor probe” is another half of the probe set that hybridizes to an adjacent sequence. When both are hybridized it brings their respective fluorescent moieties into close proximity. A signal is generated by providing a specific wavelength of light, and fluorescence is monitored during incremental temperature increase to produce a melting curve. Melting curves are utilized to produce melting peaks. As will be further described, these resulting melting peaks are analyzed to determine wild type and mutant indications, wherein a temperature change, ΔT m , separates the different peaks. “A” as used in the claims may mean one or more depending on the context of the claim. It is not necessary to use only two probes as in the present assay. There are a few other types of probes that can produce these melting peaks without using two probes. For example, there are single probe systems with a single labeled probe that will produce melting peaks.
[0025] Primers, probes, the concentration at which each is used, and the associated SEQ ID NO are listed in table 1.
TABLE 1 Forward Reverse Primer Anchor Detection Allele Primer [ ] Sequence [ ] Probe [ ] Probe [ ] Sequence μM μM Sequence μM Sequence μM N314D 5′ 0.5 5′ 0.3 5′ 0.3 5′-LC Red 640 0.14 ACTGTAAAAG GCAAGCATTTCGT CGCAGGAGCGGAG CTGCCAATGGT GGCTCTCTCT AGCCAA 3′ GGTAGTAATGAGC CCCAGTTGG-PO4 3′ CC 3′ GTGCA-FITC 3′ SEQ ID 2 3 4 5 NO Q188R 5′ 0.5 5′ 0.5 5′ 0.2 5′-LC Red 640 0.13 CTTTTGGCTA TTCCCATGTCCACA GCCAAGAAACCCA ACACCCTTACC ACAGAGCTCC GTGCTGG 3′ CTGGAGCCCCT-FITC 3′ CGGCAGTG-PO4 3′ G 3′ SEQ ID 6 7 8 9 NO S135L 5′ 0.25 5′ 0.125 5′-LC Red 640 0.1 5′ 0.2 CACAGCCAAG ACCTCACAAACCT GAAGCACATGACC CGTTACATCCA CCCTACCTCT GCACCCAA 3′ TTACTGGGTGGTG ACCAGGGGT-FITC 3′ C3′ ACGG-PO4 3′ SEQ ID 10 11 12 13 NO K285N 5′ 0.125 5′ 0.25 5′-LC Red 640 0.2 5′ 0.1 GCTGAGAGTC CCAGAAATGGTGT CTTTGAGACGTCCT GCTCTTGACCA AGGCTCTGAT TGGGGCT 3′ TTCCCTACTCCATG-PO4 3′ ATTATGACAAC-FITC 3′ SEQ ID 14 15 16 17 NO L195P 5′ 0.5 5′ 0.5 5′-LC Red 640 0.2 5′ 0.1 GAGGCTTGGA TCCATTAGCAGGG TGCCCAGCGTGAG CAGCAGTTTCC GGTAAAGGAC GCTCTCC 3′ GAGCGATCTCAGC CGCCAGATA-FITC 3′ 3′ AG-PO4 3′ SEQ ID 18 19 21 22 NO
[0026] The number of nucleotides in the primers and probes may vary slightly. For a melting analysis assay, adequate thermal stability is needed such that the melting peak (T m ) is in a useful range, which may be defined generally as 50-70° C. As such, the T m of the mismatched and matched probes should be within this range. The anchor probes serve to hold the second fluorophore in proximity to the first throughout the melting transition of the detection probe. As such, the anchor probe must have a higher Tm than the detection probe to which it is paired. Generally, at least 15% is required. In this preferred embodiment, 20-25% is allowed. So the length of the probes may vary depending upon the G/C content of the DNA to which it is hybridizing. If it is A/T rich, the probe is longer, and if it is G/C rich the probe may be shorter. Generally, this method starts with 30 nucleotides and nucleotides are either added or subtracted therefrom until a probe having desirable qualities is obtained. Such qualities include an adequately high melting temperature, no serious self hybridization or cross hybridization interactions, no serious self-interactions (folding) and no “false hybridization” within the amplified DNA fragment.
[0027] All primer pairs are designed to function under a common set of thermal cycling conditions. In this embodiment for example, all primer pairs are designed with Tm values between 59-64° C.
[0028] The organization of the anchor and detection probes for each allele is shown in FIG. 1. In this embodiment, one probe is labeled 3′ with FITC while the other probe is labeled 5′ with LC-red 640 and 3′ phosphorylated. Obviously, these labels can change if analysis takes place at a different wavelength. For example LC-red 705 could be used, which would change the interpretive guidelines as would be known in the art. Fluorescent-labeled probes are analyzed by spectrophotometry for oligonucleotide and fluorophore concentration. Probes with fluorophore/oligonucleotide ratios of 0.8-1.2 are generally suitable.
[0029] The amplicons, or PCR products, are preferably held to fewer than 200 base pairs. Though not necessary, this facilitates the optimum binding of hybridization probes. Table 2 shows the number of base pairs in the amplicons for the current assay.
TABLE 2 Allele PCR Product Length N314D 171 bp Q188R 160 bp S135L 190 bp K285N 155 bp L195P 149 bp
[0030] Following amplification, the cycling protocol proceeds seamlessly to melting analysis. Fluorescence is acquired continuously during melting curve analysis and melting curves are constructed from data acquired during the upward temperature ramp.
[0031] The following example presents the recorded preparatory procedure and results obtained for specimen preparation, hybridization, and probe analysis.
EXAMPLE
[0032] Specimens and DNA Preparation. Reference specimens, previously characterized to contain the mutations of interest, were utilized for assay development. Additional specimens were collected during routine newborn screening for galactosemia. Specimens whose reducing capacity were below 60 μM reduced NAD or whose total galactose was above 20 mg/dl were selected for mutation analysis. DNA was isolated from DBS specimens as previously described and 80-130 ηg is utilized as template in each reaction.
[0033] Amplification and Hybridization Probe Analysis. The sequence of the human GALT gene (Genbank accession number M96264) was used as a basis for primer and probe design. Primers and probes were designed in silico using Primer Premier 5.0 software. All primers and probes were HPLC purified and obtained from Operon technology (Alameda, Calif.). PCR reaction buffers, 20 mM MgCl 2 for the K285N and S135L assays, 30 mM MgCl 2 for the N314D, Q188R, and L195P assays, are obtained from Idaho Technology (Salt Lake City, Utah). All reactions use 0.6 U Klen taq DNA polymerase (AB Peptides, St. Louis, Mo.) complexed with TaqStart antibody (Clontech, Palo Alto, Calif.) according to manufacturers instructions. Primers, probes, and the concentration at which each is used are listed in table 1. The number of base pairs in the amplicons is listed in Table 2. All primer pairs were designed with Tm values between 59-64° C. and as such function under a common set of thermal cycling conditions. Amplification was performed in a Roche Light Cycler (Manheim, Germany). Cycling conditions were 40 cycles of 94° C., for 0 seconds (20°/second ramp speed)>60° C. for 20 seconds (20°/second ramp speed), >72° C., 0 seconds (2°/second ramp speed). Fluorescence was acquired at the end of the 20-second primer-annealing segment of the amplification. In the cases of N314D, S135L, and K285N assays, amplification was performed in an asymmetric fashion favoring the strand to which the hybridization probes bind (sense strand for S135L and N314D, antisense strand for K285N) while the Q188R and L195P assays were amplified in a symmetric manner. Amplicons were held to fewer than 200 base pairs (See Table 2), which facilitated optimum binding of hybridization probes. Following amplification, the cycling protocol proceeds seamlessly to melting analysis. Melting curve analysis used the following conditions: 97° C., 0 seconds, ramping at 2°/second down to 40° C., and ramping back up to 76° C. at 0.1° C/second. Fluorescence was acquired continuously during melting curve analysis and melting curves were constructed from data acquired during the upward ramp from 40° C. to 76° C.
[0034] The assays utilized “probe:probe” format for Light Cycler genotyping assays. The probe:probe format utilizes 2 oligonucleotide probes that hybridize to a selected strand of the amplicon. A detection probe was employed which matches a sequence that includes the site of the mutation and an anchor probe, which hybridizes to an adjacent sequence. In these assays there is a 1-nucleotide gap between the anchor and detection probes. One probe was labeled 3′ with FITC while the other probe was labeled 5′ with LC-red 640 and 3′ phosphorylated. Probes were designed to maximize destabilization of the mismatch hybrid and it was determined in all 5 instances that matching the mutant allele with subsequent mismatch to the wild type allele provided the most effective probe design.
[0035] Results
[0036] [0036]FIG. 2 display all 5 assays analyzed simultaneously as would be initially observed following routine analysis. The N314D, Q188R, and S135L assays display analysis of specimens that are homozygous wild type, homozygous mutant, heterozygous, and a no-amplification control. Assays for K285N and L195P show the analysis of specimens that are homozygous wild type, heterozygous, and no amplification control. Combined analysis as shown in FIG. 2 is complex, so individual assays are subsequently viewed by selecting individual specimens or groups of specimens (e.g. control and test specimens) as seen in FIGS. 3 A-E.
[0037] FIGS. 3 A-E display melting peaks for the N314D, Q188R, S135L, K285N, and L195P assays respectively. In all cases the peak representing the mutant allele is high temperature melting peak (perfect match with the detection probe) while the wild type allele is the low-temperature melting peak (mismatch hybrid with the detection probe). Melting peaks are well separated facilitating unambiguous genotype assignment for each loci. The melting temperature of each peak and the ΔT m separating the wild type and mutant peaks for individual assays are displayed in Table 3.
TABLE 3 Allele Wild Type Tm Mutant Tm ΔTm N314D 57.83 66.16 8.33 Q188R 56.80 65.47 8.67 S135L 55.08 62.09 7.01 K285N 54.89 61.41 6.52 L195P 49.94 60.57 10.63
[0038] Peak separation ranges from 6.52°-10.630° C., enabling easy and unambiguous genotype assignment.
1
21
1
1857
DNA
Homo sapiens
1
gtaactatgg atttcccctc ttacaacttt caaaccagag ttggagactc agcattgggg 60
ttcgccctgc ccgtagcaca gccaagccct acctctcggt tatcttttct cccgtcacca 120
cccagtaagg tcatgtgctt ccacccctgg tcggatgtaa cgctgccact catgtcggtc 180
cctgagatcc gggctgttgt tgatgcatgg gcctcagtca cagaggagct gggtgcccag 240
tacccttggg tgcaggtttg tgaggtcgcc ccttcccctg gatgggcagg gagggggtga 300
tgaagctttg gttctgggga gtaacatttc tgtttccaca gggtgtggtc aggagggagt 360
tgacttggtg tcttttggct aacagagctc cgtatcccta tctgatagat ctttgaaaac 420
aaaggtgcca tgatgggctg ttctaacccc cacccccact gccaggtaag ggtgtcaggg 480
gctccagtgg gtttcttggc tgagtctgag ccagcactgt ggacatggga acaggattaa 540
tggatgggac agaggaaata tgccaatgat gtggaggctt ggaggtaaag gacctgcctg 600
ttcttctctg cttttgcccc ttgacaggta tgggccagca gtttcctgcc agatattgcc 660
cagcgtgagg agcgatctca gcaggcctat aagagtcagc atggagagcc cctgctaatg 720
gagtacagcc gccaggagct actcaggaag gtgggagaga gccaagccct gtgtccccaa 780
ggagtcccta actttcttat cccatgagag aggtgtgtaa aggagaaagc tagaggtgaa 840
ctagtagaga gagacttgct aggaggcctt agcaataatc cagtaatcta aaggaaagat 900
gatggtgact tagactcggg tggttagtgg tagaggtggt gagaagacat cagatcctgg 960
gcacattctt ttcttctgct tcccttgcct atttgctgac cacactccgg ctcctatgtc 1020
accttgatga cttcctatcc attctgtctt cctaggaacg tctggtccta accagtgagc 1080
actggttagt actggtcccc ttctgggcaa catggcccta ccagacactg ctgctgcccc 1140
gtcggcatgt gcggcggcta cctgagctga cccctgctga gcgtgatggt cagtctccca 1200
agtaggatcc tggggctagg cactggatgg aggttgctcc cagtagggtc agcatctgga 1260
ccccaggctg agagtcaggc tctgattcca gatctagcct ccatcatgaa gaagctcttg 1320
accaagtatg acaacctctt tgagacgtcc tttccctact ccatgggctg gcatggtgag 1380
gcttttcaag tacctatatt tagccccaac accatttctg ggctcctggg ctcagcctag 1440
tgaactgcaa cctcaaagga gcaagccttg aaacagttgc tgggggaagt ggccagagta 1500
gagatgctgg gactgagggt ggagcagcaa acttggtgaa actacatctc caatgtgctt 1560
tctaatctcc tgccagctct tctcaagcag gggatcctgg gagatgtagt tttcagatac 1620
ctggttgggt ttgggagtag gtgctaacct ggataactgt aaaagggctc tctctcccca 1680
ctgtctctct tctttctgtc aggggctccc acaggatcag aggctggggc caactggaac 1740
cattggcagc tgcacgctca ttactaccct ccgctcctgc gctctgccac tgtccggaaa 1800
ttcatggttg gctacgaaat gcttgctcag gctcagaggg acctcacccc tgagcag 1857
2
22
DNA
Homo sapiens
2
actgtaaaag ggctctctct cc 22
3
19
DNA
Homo sapiens
3
gcaagcattt cgtagccaa 19
4
31
DNA
Homo sapiens
4
cgcaggagcg gagggtagta atgagcgtgc a 31
5
20
DNA
Homo sapiens
5
ctgccaatgg tcccagttgg 20
6
21
DNA
Homo sapiens
6
cttttggcta acagagctcc g 21
7
21
DNA
Homo sapiens
7
ttcccatgtc cacagtgctg g 21
8
24
DNA
Homo sapiens
8
gccaagaaac ccactggagc ccct 24
9
19
DNA
Homo sapiens
9
acacccttac ccggcagtg 19
10
21
DNA
Homo sapiens
10
cacagccaag ccctacctct c 21
11
21
DNA
Homo sapiens
11
acctcacaaa cctgcaccca a 21
12
30
DNA
Homo sapiens
12
gaagcacatg accttactgg gtggtgacgg 30
13
20
DNA
Homo sapiens
13
cgttacatcc aaccaggggt 20
14
23
DNA
Homo sapiens
14
gctgagagtc aggctctgat tcc 23
15
20
DNA
Homo sapiens
15
ccagaaatgg tgttggggct 20
16
28
DNA
Homo sapiens
16
ctttgagacg tcctttccct actccatg 28
17
22
DNA
Homo sapiens
17
gctcttgacc aattatgaca ac 22
18
20
DNA
Homo sapiens
18
gaggcttgga ggtaaaggac 20
19
20
DNA
Homo sapiens
19
tccattagca ggggctctcc 20
20
28
DNA
Homo sapiens
20
tgcccagcgt gaggagcgat ctcagcag 28
21
20
DNA
Homo sapiens
21
cagcagtttc ccgccagata 20 | A method is disclosed for detecting galactosemia-causing mutations in the GALT gene, comprising amplifying a portion of the GALT gene from isolated DNA and allowing a pair of labeled probes to hybridize to the portion. One of the labeled probes is adapted to match to a sequence that includes the galactosemia-causing mutation, and another of the labeled probes hybridizes to an adjacent sequence, thereby forming a hybrid. Melting curves of each hybrid are then analyzed, wherein peaks of the curves are produced at an acquired fluorescence and melting temperature, T m ; and a genotype is assigned based on the T m of the hybrid. Resulting melting peaks are compared to reference sample peaks derived from samples characterized to contain the mutations, wherein the reference sample curves indicate a temperature change, ΔT m , between mutant and wild type peaks. | 2 |
FIELD OF THE INVENTION
The present invention relates to a hoisting device, provided with a mast, on the top side provided with cable blocks; a trolley, which is movably fixed on the mast, on the top side is provided with cable blocks; and on the bottom side is provided with means for gripping a load; hoisting means, at least equipped with a hoisting cable and a winch, said hoisting cable being guided over the cable blocks of both the mast and the trolley, and it being possible to move the trolley relative the mast with the aid of the hoisting means; and a compensator, in the form of a pneumatic or hydraulic cylinder, for damping movements of the vessel as a result of heave and beating of the waves.
BACKGROUND OF THE INVENTION
Various hoisting devices are known from the prior art. These hoisting devices are used in the offshore industry as drilling masts on, for example, drilling vessels. When, in use, a drill string is attached to the bottom side of a trolley, also known as a traveling block, the compensator has to compensate for the movements of the vessel relative to the seabed. The drill string itself will rest at least partially in the earth's surface during the drilling and will make a minimal movement relative to the earth's surface. The vessel, on the other hand, does move under the influence of the waves and the flow of the water.
According to the prior art, the compensator is generally placed between two blocks or trolleys, both of which can move relative to the mast. In this case the top trolley will be provided with cable pulleys, which can be moved relative to the mast with the aid of a hoisting cable. The bottom trolley will be attached to the top trolley by means of the compensator. When in this construction forces are exerted by the drill string upon the bottom trolley, these forces will be transmitted only partially to the top trolley.
The compensator generally used operates hydro-pneumatically. The hydro-pneumatic compensator will therefore be connected to a compressed air device by means of hoses, pipes and the like. A relatively large stroke volume is necessary for good functioning of such a compensator. Since both blocks or trolleys move relative to the mast, the compensator will also be able to move relative to the mast, which is a disadvantage. The connections of the compressed air device to the compensator must in fact also be able to move relative to the mast. This requires the use of, for example, flexible hoses and pipes, and all that makes the connection relatively complex, and therefore expensive.
SUMMARY OF THE INVENTION
It is a first object of the present invention to provide for a hoisting device according to the type mentioned in the preamble, in which the connections of a compressed air device to the compensator can be fitted at a stationary point.
That object is achieved in the present invention by the fact that the hoisting cable is guided over cable pulleys which are connected to the end of the compensator, all the above in such a way that force can be exerted upon the hoisting cable with the aid of the compensator.
That means that the compensator is no longer placed between the trolleys which are attached to the mast, but that the compensator acts directly upon the hoisting cable. The compensator can be connected by a first end to a stationary section of the mast. At the other end, the compensator is connected to the hoisting cable by way of cable pulleys. Tension can thus also be applied to the hoisting cable by means of the compensator.
The advantage of these measures is in the first place that the compensator can be fastened in a fixed position in the vicinity of the mast. The connection of the compressed air device to the compensator can therefore be made a t one point. That makes a relatively simple and cheap construction possible.
The hoisting device according to the invention can be improved further by the device comprising at least two compensators, each of which is connected to cable pulleys at its end.
The effect of this measure is that the device acquires greater redundancy. If the compensator in a device according to the prior art breaks down, the drilling operations must be stopped immediately With a hoisting device according to the invention, containing more than one compensator, it is possible to continue working should one of the compensators break down. The cylinder of the compensator which fails is locked in that case. Locking the compensator will mean that the stroke of the bottom trolley is reduced, but because one or more compensators that are still active remain, the device does not have to be shut down.
It is advantageous according to the invention for the mast to be designed in the form of a tube or sleeve, and for the compensator(s) to be place in the mast.
BRIEF DESCRIPTION OF THE DRAWINGS
The present invention will be described further with reference to the appended drawings, in which:
FIG. 1 shows the hoisting device according to the present invention;
FIG. 2 shows a diagrammatic view of the fastening of the rods as described on page 10 , lines 26 - 34 ;
FIG. 3 shows a diagrammatic view of the operation of the riser connect winch via the compensator to the riser;
FIG. 4 shows the case where four loose pulleys are attached to the trolley;
FIG. 5 shows the case where two loose pulleys are attached to the trolley and two loose pulleys are attached to the mast head;
FIG. 6 shows the case where four loose pulleys are attached to the mast head;
FIG. 7A-7B shows a front view of a possible embodiment of the loose pulleys;
FIG. 8 shows a side view of one of the loose pulleys according to FIG. 7A;
FIG. 9 shows a second embodiment of loose pulley;
FIG. 10 shows diagrammatically the run of the hoisting cable over the various pulleys, in the case where four loose pulleys are attached to the trolley;
FIG. 11 shows diagrammatically a second possibility for reeving the hoisting cable;
FIGS. 12 a , 12 b and 12 c show the relationship between the number of parts of hoisting cable between the mast head and the trolley, on the one hand, and the number of parts of connecting cable between the mast head and solid ground, on the other hand;
FIGS. 13 a - 13 e show stepwise the transition form a situation in which on compensation occurs to a situation in which full compensation occurs with the aid of the connecting cable;
FIGS. 14 a - 14 d show stepwise the transition from a situation with full compensation using the connecting cable to a situation without compensation;
FIGS. 15-16 show diagrammatically the possibility of placing objects on the ground beneath the vessel using the hoisting device with passive compensation according to the present invention, fixed on a vessel.
DETAILED DESCRIPTION
There is generally sufficient space in the mast on a drilling vessel or a comparable vessel for placing the compensator. That means that the compensator itself will not require any additional space. In addition to the advantage of the space gain achieved, it is important that the mast remains readily accessible from all sides through the placing of the compensator in the mast. The compensator thus does not constitute any obstacle to, for example, the supply of equipment to the mast.
In the devices according to the prior art it is customary for a hoisting cable to be attached to a fixed point at one end. The other end of the hoisting cable is then wound around a winch. If this winch breaks down, it is no longer possible to work with the device.
It is therefore advantageous for the hoisting means to be provided with two winches, each end of the hoisting cable being wound onto a separate winch. By now winding the two ends onto a separate winch, it is possible to achieve the same cable speed at a relatively low speed of revolution of the winches. That means an enormous reduction in the wear on the cable, with the result that the cable does not have to be replaced as often.
Moreover, by adding the second winch, redundancy is provided in the system. Should one of the winches fail, then the hoisting device is not unusable, but it is possible to continue working with a single winch. It is advantageous for the winches to be driven by a plurality of relatively small motors.
For example, it is possible to equip the winches on both sides with electric motors which engage with a pinion in a toothed wheel of the winch. First, this has the advantage that such electric motors are commercially available. For the use of the hoisting device it is therefore not necessary to develop a special, and therefore expensive, hoisting winch. Secondly, the relatively small motors have a low internal inertia, which means, for example, that when the direction of rotation of the winch is reversed less energy and time are lost during the reversal.
In the case of a hoisting device according to the prior art of the type mentioned in the preamble, finding the optimum compromise between speed and power is a known problem. The hoisting cable is guided in such a way over the cable blocks in the mast and on the trolley that several cable parts extend between the mast and the trolley. In this case the more wire parts are present between the mast and the trolley, the greater will be the load that can be lifted with the hoisting device if the hoisting winch remains unchanged. However, in this case the more wire parts are present between the mast and the trolley, the lower will be the speed at which the trolley can be moved relative to the mast.
In order to find a good compromise between speed and lifting power, it is generally decided to provide the hoisting device with relatively heavy winches. The heavy winches ensure that the requirement of being able to move the trolley up and down rapidly can be met in every case. However, that also means that a substantial part of the lifting power is not being utilized for a substantial part o f the time. In other words, the device is actually provided with too heavy—and therefore too expensive—winches to be able to reach sufficient speed occasionally.
It is therefore a further object of the present invention to provide a hoisting device of the type mentioned in the preamble. By means of which, on the one had, a relatively heavy load can be lifted and on the other hand, which can be operated at a relatively high speed, while the hoisting means can be of a relatively light and cheap design.
The object is achieved in the present invention by the fact that the hoisting cable is also guided over loose pulleys, which can be moved between a first position, in which the loose pulleys are connected to the mast, and a second position, in which the loose pulleys are connected to the trolley.
The effect of this measure is that the number of wire parts between the mast and the trolley can be set as desired. When the loose pulleys are attached to the mast, few wire parts will extend between the mast and the trolley, and a relatively low weight can be lifted. When the loose blocks are attached to the trolley, a relatively large number of wire parts will extend between the mast and the trolley, and the trolley can be moved a t a relatively low speed relative to the mast. Since the hoisting cable is guided over the pulleys and the pulleys can be attached as desired to the mast or to the trolley, the hoisting cable does not have to be reeved again. That means that the desired number of wire parts can be set in a relatively short time.
It is possible according to the invention for the loose pulleys to be attached symmetrically relative to the center of the mast.
This ensures that the forces exerted upon the cables are also transmitted symmetrically to a mast, which means that no additional bending loads are exerted upon the mast.
It is possible according to the invention for the loose pulleys to be accommodated in a housing, which at least on the bottom side is provided with locking elements for fixing the pulleys on the trolley. The loose pulleys are pulled automatically into their first position, in contact with the mast, by tension in the hoisting cable. It is therefore sufficient to provide the bottom side of the pulleys with locking elements.
It is advantageous for the locking elements to be equipped with a hydraulic actuation device. The use of a hydraulic actuation device means that the locking pins can be remotely controlled.
The hoisting device according to the invention is further improved by the fact that the hoisting device is provided with a connecting cable, for connecting the vessel to a stationary section, such as the top side of the riser, which connecting cable is guided over the cable pulleys connected to the end of the compensator, in order to be able to exert a force upon the compensator with the connecting cable.
The term ‘stationary section’ according to this description is intended to convey a section which forms part of or is connected to the seabed.
The connecting cable will be fitted in such a way that when the vessel moves upwards relative to the seabed, additional force is applied to the compensator, so that its length increases. The pulleys connected to the compensator consequently move to the topside of the mast, so that a load connected to the hoisting cable will move downwards. When the vessel moves downwards, the opposite occurs. Since the connecting cable is connected to a stationary section, the load itself will not move relative to the seabed. The heave can be compensated for entirely with the aid of the connecting cable. It is obvious to connect the connecting cable to the topside of the riser. In that case the connecting cable could also e called a “riser connect winch.
It is further possible for each end of the connecting cable to be wound onto a separate winch”.
It is further advantageous to provide one of the winches with a slip brake, for paying out the connecting cable when a maximum pulling force in the connecting cable is exceeded. The slip brake ensures that a maximum pulling force can be applied to the connecting cable if that is desired in use. If the force on the cable becomes higher, the winch will pay out the cable so that the pulling force does not exceed the previously set value.
It is further advantageous for the connecting cable also to be guided over loose pulleys, which are movable between a first position, in which the loose pulleys are connected to the mast, and a second position, in which the loose pulleys are connected to the stationary section, such as the top side of the riser.
For good functioning of the heave neutralization by means of the connecting cable, the working length of the connecting cable must be adapted to the working length of the hoisting cable. That means that the moment the number of parts of the hoisting cable between the mast and the trolley is changed, it must also be possible to change the number of parts of the connecting cable between solid ground (riser) and the mast.
According to the invention, it is further possible for the mast to be provided at the topside, on both sides of the hoisting cable, with a fastening for attaching a pull rod or pull cable. These fastenings can each be used for coupling a pull rod, for example a drill pipe, which pull rods are connected by means of a clamp at the bottom side. Said clamp can be used for clamping, for example, the drill string. This produces in a simple and advantageous manner a system that ensures that a load can be attached to the mast, while the hoisting block above the load is free for carrying out hoisting operations.
The present invention in a second aspect relates to a method, by means of a passive compensator, for placing an object on the ground.
The method according to the present invention is characterized in that: the compensator is placed under a tension that is equal to the underwater weight of the object that has to be taken downwards by the hoisting device,
the object is moved downwards by paying out the hoisting cable with the aid of the winch,
the hoisting cable continues to be paid out until the object makes contact with the bottom. At that moment a switch-over is made to the low gas pressure system,
the object now remains standing on the seabed at a previously set gas pressure.
In the manner described above it is possible for a heavy object to be place in a very controlled manner on the ground beneath a vessel. The danger of an object hitting the ground with great force and consequently being damaged is minimized in this way.
FIG. 1 shows the hoisting device 1 according to the present invention. The hoisting device 1 comprises a mast 2 . In the description below the term mast will always be used, but it must be understood that any other suitable device, such as, for example, a tower, could also be used.
The topside of the mast 2 is formed by a masthead 3 . A large number of cable pulleys are fixed in the masthead 3 . First, two cable pulleys 4 are fitted on an axis 41 . Below that, on the rear side of the mast, four cable p pulleys 5 are mounted on an axis 51 . On the front side of the mast, four cable pulleys 6 are mounted on an axis 61 . Furthermore, a middle pulley 7 is fixed on the front side of the mast, the axis of said pulley 7 being substantially perpendicular to the axis of the pulleys 4 , 5 , and 6 .
The hoisting device further comprises a trolley 10 . Said trolley 10 can move along a guide 11 relative to the mast 2 . On the bottom side, the trolley 10 is provided with a bracket or hook 12 , or some other suitable means, to which a load to be hoisted can be attached. FIG. 1 shows the case in which a top drive 13 with a drill string 14 fixed below it is attached to the hook 12 . On the top side, the trolley 10 is provided with two cable pulleys 15 . The trolley 10 is connected to the mast head 3 by the cable 16 , which runs by way of several reevings between the cable pulleys 15 on the trolley and the various cable pulleys in the mast head 3 .
In addition to the above mentioned cable pulleys 4 , 5 , 6 , 7 and 15 , four “loose pulleys” 17 are also present in the hoisting device 1 . These loose pulleys 17 may be attached as desired to the mast head 3 or to the trolley 10 . The coupling of the loose pulleys 17 to the mast head 3 or to the trolley 10 is shown in detail in FIGS. 4-9.
The advantage of the presence of the loose pulleys 17 is that the number of wire parts of the cable 16 that extend between the mast head 3 and the trolley 10 can be varied. If the loose pulleys 17 are attached to the mast head 3 , a limited number of wire parts will extend in the direction of the trolley 10 . That means that, on the one hand, a relatively limited weight can be lifted with he aid of the hoisting device, but, on the other hand, the trolley 10 can be moved relatively quickly in the direction of the mast head 3 . If the loose pulleys 17 are attached to the trolley 10 , a relatively large number of wire parts will extend from the mast head 3 in the direction of the trolley 10 . That means that a relatively great weight can be lifted with the aid of the trolley 10 , but that said trolley 10 will be moved at a relatively slow speed relative to the mast head 3 . By distributing the number of loose pulleys 17 as desired over the mast head 3 and the trolley 10 , it is ensured that both the weight to be lifted with the hoisting device and the speed at which the trolley 10 can be moved relative to the mast head 3 are adjustable.
In the prior art a known problem is that a hoisting device often has to be equipped with a relatively large drive, in order to be able to achieve a workable compromise between the maximum lifting power and the minimum speed to be achieved. This problem is solved by the “loose pulleys” according to the present invention.
In the hoisting device 1 according to FIG. 1 the cable 16 extends from a first hoisting winch 18 in the direction of the mast head 3 . The hoisting winch is also known as a draw work. The hoisting cable 16 is subsequently guided back to a second hoisting winch 19 . In the prior art it is customary for an end section of the hoisting cable 16 to be fixed at a fixed point, the other end being rolled up on a hoisting winch. Several advantages can be obtained by making use of two hoisting winches 18 , 19 , as in the hoisting device 1 . In order to achieve a certain speed of the trolley relative to the mast head 3 , the speed of rotation of the hoisting winches 18 and 19 can be kept twice as low as it could if only one hoisting winch were used. The effete that can be obtained by keeping the speed of the hoisting winches 18 , 19 relatively low is that little wear will occur in the cable 16 . Should one of the two hoisting winches fail during use, work can continue using another hoisting winch. In the prior art the failure of a hoisting winch immediately means that the hoisting device can no longer be used. The hoisting winches 18 , 19 are preferably driven by electric motors. In the case of each hoisting winch, for example, each side of the hoisting winch 18 , 19 can be provided with such a motor. That means that each hoisting winch is driven by 2 electric motors. First, this has the advantage that the electric motors to be used can be kept relatively small, which means that these motors do not have to be designed specifically for the hoisting purposes, but will be in stock on the market. Secondly, the use of the relatively small motors has the effect that the internal inertia in the motors is kept low. That means that when the direction of rotation of the winches 18 , 19 is reversed the internal inertia of the drive elements themselves will not give rise to problems.
In FIG. 1, in addition to the cable pulleys mentioned, there is further a first set of two and a second set of two cable pulleys 20 , connected to the top side of two compensators 21 , The compensators 21 are connected at the bottom side in the connection point 22 to the mast 2 . The hoisting device 1 according to the present invention can advantageously be used for numerous hoisting operations. The hoisting device 1 is particularly advantageous when used in the case of drilling operations, from a vessel. The reason for this is that, particularly in the case of such drilling operations, in some parts of the drilling processes has to be possible for a very great hoisting force to be applied, and that in other parts of the drilling process the speed at which the trolley can move relative to the mast in the most important factor. In the case of hoisting devices which are used on such drilling vessels, it is common to place a compensator in the device. Said compensator is generally fitted on the bottom side of the trolley 10 . A device is then place on the bottom side of the compensator, to which device, for example, the top drive of a drill string can be connected. By means of such a fastening of the compensator, the compensator will move relative to the mast. For good functioning, the compensator must be connected to supply means for compressed air. When the compensator moves relative to a mast, this compressed air installation must be connected in a complex—and therefore relatively expensive—manner to the compensator, for example by means of flexible hoses and the like.
According to the invention, it has now been decided to fit the compensators 21 in the mast 2 , in which case the bottom side 22 of the compensators will be attached to a stationary point of the mast 2 . The position of the bottom side of the compensators relative to the mast is therefore the same at all times. That means that the installation for supplying air pressure can always be connected to the compensators 21 at the same point. This ensures that the coupling between the air pressure installation and t h e compensators can be made many times simpler that is the case in the prior art.
Two compensators 21 are deliberately illustrated in the mast. The device 1 can function extremely well with only one compensator 21 , but the addition of at least a second compensator is advantageous. Should one of the two compensators fail to function or break down, it is still possible to go on working with the aid of the device. In the prior art the breakdown of the compensator meant immediate stoppage of the hoisting device. That is prevented with the invention.
The hoisting device according to FIG. 1 is further provided with a connecting cable, which provides for a connection between solid ground and the pulleys 20 which are connected to the compensators 21 . The connecting cable is omitted in FIG. 1 in order to keep the drawing clear to view. The functioning of the connecting cable is explained with reference to FIG. 3 .
The mast according to FIG. 1 is illustrated diagrammatically in FIG. 2 . The mast 2 is provided with fastenings 101 on the top side. These fastenings 101 can each be used for connecting a pull rod, for example a length of drill pipe 102 , which pull rods are connected at the bottom side by means of a clamp 103 . Said clamp 103 can be used for clamping, for example, the drill string 14 , at a moment when the drill string does not need to move up and down with the aid of the trolley 10 . This is a simple and advantageous way of producing a system which ensures that a load can be attached to the mast 2 , while the hoisting block 10 above the load is free for carrying out hoisting operations.
FIG. 3 shows a diagrammatic side view of the drill mast according to FIGS. 1 and 2. In addition to the hoisting cable 16 , the connecting cable 105 can also be seen. This connecting cable 105 is guided over the cable pulleys 20 , which are connected to the end of the compensator 21 . The object of this is to be able to exert a force on the compensator 21 with the connecting cable 105 . The presence of the connecting cable 105 means that there is a connection between the pulleys 20 and the seabed, or a section that is connected to the seabed.
The connecting cable 105 will be fitted in such a way that when the vessel moves upwards relative to the seabed, additional force is exerted upon the compensator 21 . This makes the compensator 21 longer. The pulleys 20 connected to the compensator 21 move in the direction of the mast head 3 . This releases a section of the hoisting cable that was clamped in the mast 2 between the top side of the mast and the pulleys 20 , so that a load connected to the hoisting cable 16 moves downwards. When the vessel moves in the direction of the seabed, the opposite occurs. Since the connecting cable 105 is connected to a stationary section, the load itself will not move relative to the seabed. The heave can be compensated for completely with the aid of the connecting cable.
It is also possible foe each end of the connecting cable 105 to be wound onto a separate winch 106 , 107 . In use, it is advantageous if the connecting cable can either be hauled in/paid out very quickly or the hauling in of the cable can be carried out with great force. The placing of the connecting cable 105 in position and the operation of the winches 106 and 107 are explained with reference to FIGS. 13 a - 13 e.
The possibility of varying the number of hoisting parts between the mast head 3 and the trolley 10 is built into the system of the hoisting cable 16 . This possibility is discussed in detail with reference to FIGS. 4-9. For good functioning of the heave neutralization by means of the connecting cable 105 , the working length of the connecting cable 105 must be adapted to the working length of the hoisting cable 16 . In other words, the moment the number of parts of the hoisting cable 16 between the mast 2 and the trolley 10 is changed, it must also be possible to change the number of parts of the connecting cable 105 between solid ground (riser) 78 and the mast 2 .
FIG. 4 illustrates the case where four loose pulleys 17 are attached to the trolley 10 . It can be seen in FIG. 4 that four pulleys 17 are attached to the trolley 10 . This means that twelve wire parts extend between the trolley 10 and the mast head 3 .
FIG. 5 shows the case where two loose pulleys 17 are attached to the mast head 3 and two loose pulleys 17 are attached to the trolley 10 . In this case eight wire parts will extend between the mast head 3 and the trolley 10 .
FIG. 6 shows the case where four loose pulleys 17 are attached to the mast head 3 . That means that only 4 wire parts will extend between the mast head 3 and the trolley 10 . As will be understood, the highest weight can be lifted in the configuration according to FIG. 4, since in that case twelve wire parts extend between the mast head 3 and the trolley 10 . In the configuration according to FIG. 6 relatively little weight can be lifted since only four wire parts extend between the mast head 3 and the trolley 10 . However, the trolley 10 can be moved at a relatively high speed relative to the mast head 3 .
It can be seen in FIGS. 4, 5 and 6 that on the left-hand side of the mast 2 exactly the same number of loose pulleys 17 are attached to the mast head 3 as on the right-hand side. That means that the forces of the cable 16 on the mast will be distributed symmetrically.
FIG. 7A shows a front view of a part of the trolley 10 , with a fixed pulley 15 and loose pulleys 17 thereon. The block will be designed symmetrically, with loose pulleys 17 being placed on both sides of the fixed pulley (only two pulleys 17 are illustrated in the figure). On the bottom side, the loose pulleys 17 are provide with a lock or hook 104 which interacts with a lug or pin 121 on the trolley 10 . The pulleys 17 can be fixed on the trolley as desired. Since there will always be a certain tension on the hoisting cable 16 , the loose pulleys 17 are pulled automatically in the direction of the mast head 3 . For that reason, fastening means can be dispensed with on the top side of the pulleys 17 . However, if the tension is lost completely, a pulley 17 will fall downwards by the force of gravity. In order to be on the safe side, the hoisting device is therefore provided with a safety facility, which can be as designed in, for example, FIG. 7 B. According to FIG. 7B, a pulley 17 is provided on its top side with two balls which are connected to the housing of the pulley 17 in such a way that they are movable relative to each other. The balls are accommodated in recesses 123 in the mast head 3 . If no force at all is exerted upon the pulley 17 , the force with which the balls lock the pulley in the mast head is sufficient to hold the pulley 17 in place. However, if a slight force is exerted upon the pulley, the balls are released from the recesses, and the pulley 17 can the move downwards.
FIG. 8 shows a side view of one of the loose pulleys 17 according to FIG. 7 A. The lock 104 is shown in two positions. The position of the lock is determined with the aid of a cylinder 124 . When the cylinder is not actuated, the lock falls behind the pin 121 during to-blocks pulling (see above). The pulley 17 is thus connected to the trolley 10 . When the trolley 10 during use is move relative to the mast head 3 , the trolley 10 takes that loose pulley 17 along with it downwards. If, on the other hand, the cylinder is actuated, the hook cannot grip behind the pin 1221 , and that means that the trolley 10 cannot take the pulley along with it, so that the pulley 17 remains behind in the mast head 3 .
The cylinder 124 by means of which the lock 104 is operated has been deliberately placed in the mast head 3 . The fact is that the trolley 10 goes into the so-called Hazardous Area on a drilling platform or vessel. During the drilling, gas or oil can escape in this area. Non-explosive equipment must be worked with in the Hazardous Area. For that reason, it has advantages to place the cylinder 124 on /in the mat head 3 .
FIG. 9 shows a further embodiment of the loose pulley 17 , the loose pulley 17 comprises an outer housing consisting of two plates 53 . Both on the top side and on the bottom side, these plates 53 are provided with eyes 54 , in which locking pins are received. Said locking pins move through eyes 55 , which are cut out in, for example, a U-shaped fastening element 51 . This fastening element 51 can be attached either to the trolley or to a mast head. In use, the trolley 10 will be hoisted to a position as close as possible to the mast head 3 . This position is also known as to-blocks. After that, either the locking pins 52 belonging to the trolley 10 or the locking pins 52 belonging to the mast head 3 will be moved into the eyes 54 of the plates 53 . In this way a choice can be made concerning which loose pulleys 17 are connected to the mast head 3 and which pulleys 17 are connected to the trolley 10 .
FIG. 10 shows the run of the cable 16 from the hoisting winch 18 over the successive cable pulleys in the direction of the hoisting winch 19 . FIG. 10 shows the case where the four loose pulleys 17 lie substantially in line with the two pulleys 15 which are immovably fixed to the trolley. That means that in the case shown in FIG. 10 twelve wire parts will extend between the mast head 3 and the trolley 10 .
FIG. 11 shows a further reeving plan for the hoisting cable 16 which can be used for the device according to the invention.
In FIGS. 12 a - 12 c the setting of the correct number of hoisting parts in the hoisting cable 16 and the connecting cable 105 respectively is illustrated further. It can be seen in the figures that the connecting cable is guided over at least one loose pulley 125 . Said loose pulley 125 is movable between a position in contact with the mast head 3 (see FIG. 12 b ) and a position in which the loose pulley 125 is situated in the vicinity two further pulleys 127 , which guide a further part of the connecting cable (FIGS. 12 a and 12 b ).
According to FIG. 12 a , there are twelve hoisting parts in use between the mast head 3 and the trolley 10 . This large number of hoisting parts in the hoisting cable 16 is generally used only during the placing of the riser and the BOP (see FIGS. 15 - 18 ). In that case the riser connect winch is not needed. It can therefore be seen in FIG. 12 a that the connecting cable 105 is not being used in this case.
According to FIG. 12 b , there are eight hoisting parts in use between the mast 2 and the trolley 10 . In this case the loose pulley 125 over which the connecting cable 105 is being guided is in contact with the mast head 3 . Between said mast head 3 and the fastening of the connecting cable 105 to solid ground (riser 78 ) there are four parts in use.
According to FIG. 12 c there are only four hoisting parts present between the mast head 3 and the trolley 10 . In this case the loose pulley 125 is connected to the remaining pulleys 127 .
FIGS. 13 a - 13 e show stepwise the transition from a situation in which no compensation occurs (no connecting cable active) to a situation in which full compensation occurs with aid of the connecting cable. In particular, FIGS. 13 a - 13 e shows the compensator ( 21 ), the connecting cable ( 105 ), winches ( 106 and 107 ), and the hoisting cable ( 16 ).
Putting the riser connect winch into position is carried out as follows:
The compensator 21 is positioned in the lowest position the moment the vessel finds itself in the trough of a wave or moves downwards (FIG. 13 a ). A certain pulling force is then exerted upon the connecting cable 105 . At least one of the winches 106 , 107 (shown in FIG. 10) is operated in such a way that the connecting cable 105 can follow the movement of the vessel relative to the seabed (FIG. 13 b ). The winches 106 and 107 are controlled in such a way that they take the slack out of he connecting cable. When the cable is taut, the passive compensator is taken slowly to the middle position. The riser connect winches are then stopped and there is active compensation in the system by means of the connection of the riser.
The connecting cable can also be used during drilling. The moment a drill head on a drill string makes contact with the earth's surface the tension on the hoisting cable 16 will decrease slightly. This decrease in the load upon the hoisting cable is taken over by the connecting cable. Depending on the rigidity of the drill string and the hardness of the ground, this load will vary between a value equal to zero and the value of the full weight of the drill string. On account of the possibly high loading on the connecting cable 105 , care must be taken to prevent overloading of said cable 105 ( 13 e ).
FIGS. 14 a - 14 d show stepwise the transition from a situation with full compensation (using the connecting cable) to a situation without compensation. In particular, FIGS. 14 a - 14 d shows the compensator ( 21 ), the connecting cable ( 105 ), winches ( 106 and 107 ), and the hoisting cable ( 16 ).
When the function of the connecting cable has to be ended, first of all a maximum tension is placed upon the connecting cable 105 by means of the fast winch ( 14 a ).
The cable on the winch is hen paid out, and the compensator slides in/out.
If desired, the compensator can be locked if it is slid in fully. In addition, the cable on the winch is paid out further, so that the connecting cable ultimately hangs loose.
A known problem in the case of drilling vessels according to the prior art is the placing of heavy objects on the bottom of, for example, the sea. With reference to FIG. 12 a , it is pointed out above that the connecting cable 105 is not used during the placing of objects, such as the riser and the BOP, on the seabed. Owing to the presence of the passive compensators in the reeving of the hoisting cable 16 , the placing of such objects on the seabed according to the invention can, however, be carried out in an advantageous manner. This is described below with reference to FIGS. 15 and 16.
According to FIGS. 15 and 16, a load, such as, for example, a blow-out preventer (BOP) 71 is moved in the direction of the seabed 900 beneath a drilling vessel 70 (shown diagrammatically). The BOP is, for example, placed on a template 72 present on the seabed 900 . Since the drilling vessel 70 will never be entirely stationary relative to the seabed 900 , owing to the waves and the heave, during the placing of the BOP 71 on the template there is the risk that, owing to the heave of the vessel 70 , the BOP will be placed on the template 72 at an uncontrolled speed. The BOP 71 could be damaged as a result. According to FIG. 16, the load has reached the seabed 900 .
The system according to FIGS. 15 and 16 works as follows:
The installation on the vessel 70 consists of one or two hydraulic cylinders or compensators 12 . Said compensators 21 are connected to pressure vessels 130 filled with gas, so that a certain pre-pressure is built up in the pressure vessels. The compensators 12 are connected to the pressure vessels 130 by way of a medium separator 131 , also known as a hydraulic accumulator. The pre-pressure or P(load) of one of the pressure vessels corresponds to the hydraulic pressure in the compensator that is needed to keep the load 71 in balance under water. Another pressure vessel 130 is provided with a low pre-pressure P(low) which corresponds to the tension on the hoisting cable 16 at the moment when the load 71 makes contact with the seabed (see FIG. 16 ). Various valves 132 are incorporated in the system, in the connection between the hydraulic compensator 21 , the hydraulic accumulator 131 and the pressure vessels 130 .
When the load is under water, the loading in the hydraulic compensators 21 corresponds to the loading upon the hoisting device. The hydraulic compensators are connected to only one of the pressure vessels 130 , by way of the hydraulic accumulator 131 . During the sinking of the load, the valves A and C (see FIGS. 15 and 16) are open, while the valves B and D are closed The system reacts as a heave compensator with a rigid characteristic. The operator of the system can determine the position of the load by means of the hoisting device. When the load 71 reaches the seabed, the valves A and C are closed and the valves B and D are opened simultaneously. At that moment the system reacts as a system of constant tension, in the case of which the loading upon the hoisting device is kept constant at a predetermined (low) value. Since a relatively large gas volume is present in the hydraulic accumulators, the system now has the characteristic of a slack spring. In this configuration the system compensates for movements of the vessel 70 relative to the seabed. | The invention is a hoisting device for a vessel with a mast in the form of a tube or sleeve with fixed cable blocks on the top side, a trolley with moveable pulleys, a feature on the bottom side for gripping a load, a hoisting system with at least a hoisting cable and a winch, wherein the hoisting cable is guided over the cable blocks and pulleys of both the mast and the trolley in order to move the trolley relative to the mast with the aid of the hoisting system, and a compensator located in the mast in the form of a pneumatic or hydraulic cylinder for damping movements of the vessel as a result of heave and beating of the waves characterized in that the hoisting cable is guided over cable pulleys that are connected to the ends of the compensator. | 4 |
BACKGROUND OF THE INVENTION
1. Field of the Invention
The biotechnological production of useful materials and mixtures thereof by cultivation of selected microorganism populations is now of considerable industrial significance. The production of washing- and/or cleaning-active enzymes, more particularly from the classes of proteases, cellulases, lipases and amylases, and the production of pharmacologically active useful materials are mentioned purely by way of example in this regard. Aqueous preparations of intracellular and/or extracellular useful materials contaminated by a number of impurities, for example parts of the nutrient medium, accumulate as primary process products. Extensive prior art literature is available on the working up of such culture broths, cf. for example the article by W. Rahse et al. entitled "Mikrofiltration von Fermenterbruhen (Microfiltration of Fermenter Broths)" in Chem.-Ing.-Techn. 57 (1985), No. 9,747 to 753 and the primary literature cited therein. Examples of relevant patents include, for example, EP-B1 0 200 032, WO 93/16173 and earlier German patent applications DE 43 10 506 and DE 43 22 229.
2. Discussion of Related Art
The multistage working-up of these biotechnologically obtained aqueous culture solutions seeks in particular to remove unwanted constituents by optionally multistage filtration and/or by washing, generally followed by solidification of the aqueous preparation using solid carriers. In the bacteriological production of washing- and cleaning-active enzymes, which is of particular commercial relevance, a particular problem lies in the following situation: through the metabolism in the fermentation process, the biomass-containing fermenter broths contain small quantities of low molecular weight compounds, more particularly corresponding nitrogen compounds, which are distinguished by a highly obtrusive unpleasant odor and which can promote the degradation of the biotechnological useful materials to form other foul-smelling compounds. A typical example of these phenomena can be found in the biotechnological production of proteases or protease solutions which are intended for use in detergents, more particularly as a mixture component in laundry detergents. In addition to the prior art literature already mentioned, reference is also made in this regard to International patent application WO 91/2792. A biomass-containing fermenter broth containing around 70,000 protease units per gram (PU/g) is obtained using selected microorganisms (Bacillus licheniformis--ATCC 53926) by a process similar to the process described in German patent DE 29 25 427. In addition to dissolved proteases, salts, proteins and metabolism products, the fermenter broth also contains undissolved constituents, such as bacillus cells, residues of nutrient medium and mucilaginous substances. During the working-up of the fermenter broths (WO 92/11347), the proteases are stabilized and relatively coarse particles and undissolved constituents are removed by decantation or microfiltration. The protease solution is concentrated by ultrafiltration and subsequent evaporation in vacuo. The protease solution obtained is mixed with solid carrier materials and granulation aids and made up into enzyme granules for use in detergents.
Despite the elaborate purification and working-up processes, the concentrated protease solution still contains small quantities of low molecular weight nitrogen compounds with an unpleasant odor which can additionally accelerate degradation of the protease in storage to form other foul-smelling sulfur compounds, for example mercaptans or thioethers.
The problem addressed by the teaching according to the present invention was to remove these low molecular weight odorous compounds in an additional but simple step to such an extent that products of substantially neutral odor would be obtained, in particular after the usual encapsulation of the useful materials or mixtures thereof, self-initiated decomposition processes being ruled out or at least largely suppressed at the same time. The teaching according to the invention is disclosed in the following with reference to the production of correspondingly treated washing- and cleaning-active proteases from corresponding biotechnologically obtained fermenter broths. However, the teaching according to the invention is by no means confined to this particular example. The principles discussed in the description of the invention may be broadly applied to the field in question of useful materials and solutions thereof from biotechnological production and to related fields.
DESCRIPTION OF THE INVENTION
In a first embodiment, the present invention relates to a process for removing odorous compounds from liquid preparations of useful materials, more particularly in the recovery of useful materials from biologically obtained culture broths, characterized in that the liquid preparation is treated as a sprayed material with steam present as superheated steam under the working conditions of the spray zone.
The process according to the invention is particularly suitable for deodorizing and stabilizing aqueous preparations from the working-up of biotechnological culture broths, more particularly corresponding fermenter broths, the treatment of the sprayed liquid phase with the superheated steam in the sprayed zone preferably being carried out under reduced pressure. The choice of this process parameter of reduced pressure in the spray zone enables the maximum temperature of the material sprayed as droplets in the spray zone in contact with the superheated steam to be safely controlled in the manner described in detail in the following.
In another embodiment, the present invention relates to the use of the process for deodorizing liquid preparations of useful materials by treatment thereof with superheated steam in the spray zone for long-term stabilization of the activity of the useful materials and for removing the odorous substances from starting materials, more particularly water-containing starting materials, which contain dissolved and/or dispersed biotechnologically obtained useful materials.
PARTICULARS OF THE TEACHING ACCORDING TO THE INVENTION
Earlier hitherto unpublished International patent application PCT/EP 94/00563 describes an improved process for the distillation-based separation of multicomponent mixtures by steaming. In a first embodiment, the teaching of this earlier application relates to a process for intensifying and/or accelerating the distillation-based separation of multicomponent mixtures of at least partly organic origin by steaming with steam superheated at the working pressure to facilitate the removal of steam-volatile components of the starting material, the process being characterized in that a starting material which is liquid under the working conditions is steamed after spraying in the form of fine droplets, the starting material is sprayed by means of a propellent gas and superheated steam is used as the propellent gas.
A modified embodiment of this process according to the earlier patent application cited above is characterized in that an at least substantially water-free starting material which is liquid under the working conditions is sprayed into a stream of the superheated steam without using the propellent gas. Although this patent application mentions numerous fields of application and special examples of the application of this technology of deodorizing by steaming, it does not mention the field with which the invention is concerned, namely preparations of useful materials, more particularly water-containing preparations, from the field of biotechnological processes. The disclosure of the earlier application in question and the references therein to further prior art publications are hereby included as part of the disclosure of the present invention.
The principle of spraying the liquid preparation to be purified or deodorized using a propellent gas, namely superheated steam, as envisaged in this earlier application, may also be applied in the embodiment of the present invention presently under discussion. In a preferred embodiment of the invention, however, the liquid starting material is sprayed into a stream of the superheated steam without using a propellent gas. The teaching according to the invention is distinguished from the variant of the earlier application discussed in the foregoing by the fact that the material to be deodorized and/or stabilized is generally present in the form of an aqueous preparation of useful materials. Fermenter broths and other biotechnologically obtained primary products generally accumulate in the form of water-containing preparations with considerable water contents. Thus, the water content of the starting materials to be purified in accordance with the invention is generally at least 15% by weight and preferably at least 35 to 40% by weight. In the field of detergent enzymes, an aqueous phase containing useful materials which has a water content of at least about 50% by weight and, for example, of 60 to 80% by weight is generally obtained as the product of primary and secondary purification stages. Aqueous solutions containing extracellular detergent proteases, which have been purified by optionally multiple-stage filtration and concentrated by additional evaporation in vacuo, generally contain around 55 to 75% by weight of aqueous phase before subsequent mixing with carrier materials, more particularly solid carrier materials. These water-containing preparations of useful materials are the preferred starting material according to the invention for deodorization and stabilization by treatment with superheated steam in the spray zone. In the preferred embodiment, no propellent gas is used. The aqueous protease solution is treated, preferably in countercurrent, with superheated steam flowing through the spray zone under the process conditions described in detail in the following. This treatment may be carried out in one or more stages. A multistage treatment in the spray zone is generally preferred. This multistage treatment may be carried out by partial recycling of the aqueous phase into the spray zone, although it is also possible to arrange several spray zones one behind the other. These spray zones arranged in the form of a cascade may be operated under the same or different conditions. For the adequate deodorization and stabilization of aqueous protease solutions, a two- to five-stage treatment of the aqueous starting solution in the spray zone can lead to satisfactory purification.
Useful materials containing viable organisms or constituents thereof, such as enzymes or other products of biotechnological cultures, and mixtures of such useful materials are often highly sensitive to temperature. This applies in particular to detergent enzymes, for example proteases of the described type. The working-up of the biological material has to take this temperature sensitivity into consideration. This does of course also apply in particular to the treatment stage with superheated steam according to the present invention. The teaching according to the invention controls and satisfies this requirement very simply by predetermining and monitoring the maximum temperature of the material in the spray zone by establishing and regulating the pressure conditions therein. According to the invention, the spray zone is generally operated in vacuo. The vacuum specifically established in the spray zone determines the boiling temperature of the water. The water introduced in comparatively large quantities with the liquid starting material also performs the protective function of regulating temperature in the spray zone. The superheated steam, which is optionally introduced at temperatures of the spray zone considerably above that boiling point, cannot lead to unwanted heating of the droplets of material in the spray zone as long as an adequate concentration of liquid aqueous phase in the droplets is guaranteed. The thermal energy introduced with the superheated steam is collected by corresponding evaporation of part of the water without any significant increase in temperature in the droplets. The working conditions to be applied in accordance with the invention make use of this natural law. Preferred working conditions in the spray zone are those under which there is very little, if any, simultaneous concentration of the aqueous starting phase. This rule applies at least to highly temperature-sensitive useful materials such as detergent proteases.
If desired, however, the process as a whole may also be modified to the extent that comparatively highly diluted starting solutions of the biotechnological useful materials are delivered to the spray zone where they are not only deodorized, but also partly concentrated (cf. earlier application PCT/EP 94/00563).
For the purification and stabilization of detergent proteases in accordance with the invention, it can be useful to maintain material temperatures in the spray zone of at most about 45° to 50° C. and preferably in the range from at most about 35° to 40° C. In particularly preferred embodiments, material temperatures of at most about 30° C. are established in the spray zone, the working conditions and, in particular, the vacuum to be established in the spray zone often being adapted to maximum boiling temperatures of the water of about 20° to 25° C. The particular choice of the working pressure in the spray zone is determined by the natural dependence of the boiling point of the water upon the working pressure established. In practice, working pressures in the spray zone of about 10 to 250 mbar and preferably in the range from about 15 to 50 mbar can be useful.
The steam introduced into the spray zone for the purifying treatment may be used at temperatures considerably above the boiling temperature of water under the working conditions. Thus, the temperature of the steam introduced may be at least 50° C. and preferably at least 100° C. above the boiling temperature of water under the working pressure of the purifying stage. Temperatures at least 150° to 200° C. above the boiling temperature of water under the working pressure of the purifying stage can be suitable. Based on normal pressure, preferred temperatures for the steam according to the invention are up to 250° C. and preferably up to 200° C. temperatures of around 130° to 200° C. being particularly preferred.
In preferred embodiments, the water-containing starting material to be purified can be delivered to the spray zone at a temperature which corresponds at least substantially to the boiling temperature of water under the working conditions. However, the limiting factors arising out of the temperature sensitivity of the biological useful material will of course have to be taken into account in this regard. In practice, therefore, the temperature range for the liquid starting material to be delivered to the spray zone, for example in the purification of aqueous protease solutions, will generally be in the range from about 20° to 35° or 40° C.
Another feature of the aqueous enzyme solutions to be treated in accordance with the invention can also be of importance. Aqueous culture solutions of biotechnological useful materials are often distinguished by a certain thixotropic behavior. The flowability of the aqueous mixture of useful materials can be ensured by suitable auxiliary measures, more particularly by the introduction of shear forces into the material to be purified. More particularly, the design and construction of the spray zone should also ensure that the sprayed material can be reliably discharged. In overall terms, the establishment of the working conditions for spray purification in accordance with the invention can be co-determined by this effect, as known per se to the expert. Characteristic working parameters of relevance in this regard are given in the following process Example.
EXAMPLE
A biomass-containing fermenter broth with a content of around 70,000 protease units per gram (PU/g), prepared by fermentation of Bacillus licheniformis (ATCC 53926) by the process described in German patent DE 29 25 427, is distinguished by an undesirably strong odor. Besides dissolved proteases, salts, proteins and metabolism products, this fermenter broth also contains undissolved constituents, such as bacillus cells, residues of the nutrient medium and mucilaginous substances. The fermenter broth initially accumulating is first worked up in accordance with International patent application WO 92/1134, relatively coarse particles and undissolved constituents being removed by decantation or microfiltration. The protease solution thus prepurified is concentrated by ultrafiltration and subsequent evaporation in vacuo. The protease solution thus concentrated can be mixed with solid carrier materials and granulation aids and made up into enzyme granules for use in detergents.
The protease solution thus worked up and hence the enzyme granules are also distinguished by an unwanted odor. In addition, the low molecular weight nitrogen compounds responsible, which are present in small quantities, accelerate the protease degradation process which in turn leads to the formation of other foul-smelling sulfur compounds (for example mercaptans, thioethers).
To remove the odorous compounds, the aqueous protease solution is deodorized in the spray zone in an additional process step carried out in accordance with the invention after evaporation in vacuo. The following parameters are applied in this additional process step:
The aqueous enzyme solution has a dry matter content (enzymes+fermentation residues) of 35% and the following data at 25° C.: Density: 1,100 kg/m 3
TABLE 1______________________________________Viscosity of the Aqueous Enzyme Solution as a Functionof the Shear RateShear Rate (S.sup.-1) Viscosity (mPas)______________________________________32.5 16054.3 116106.0 81.8150.9 69.8252.3 57.0420.3 50.0701.3 43.51169.0 41.0______________________________________
During the deodorizing treatment, the enzyme solution was sprayed into a tank from above. The enzyme solution collected at the bottom of the tank and was recycled to the spray nozzle. The superheated steam entered the deodorizing tank in uniform distribution in countercurrent to the liquid.
The steam and the odorous substances entrained were discharged through a vacuum system with condensation of the steam. The pressure in the tank was 20 mbar absolute. Table 2 shows the dimensions of the deodorizing tank and the nozzle and the operating parameters adjusted.
TABLE 2______________________________________Dimensions of the Deodorizing Tank and Operating Parametersfor the Tests with Protease Solution Dimensions1. Deodorizing tank: Diameter 300 mm Height 1,200 mm2. Hollow cone nozzle Diameter 0.6 mm Mean volumetric droplet diameter around 60 μm Operating parameters Protease solution Throughflow 10 kg/h Pressure at nozzle 10 bar Temperature 25° C. Steam Throughflow 1.7 kg/h Pressure 1 bar abs. Temperature 170° C.______________________________________
The protease solution was recycled through the deodorizing stage three times and then made up into enzyme granules as described above. The odor notes of the enzyme granules improved from 4.5-5 to 3 (evaluation under the school marking system of 1 to 5). | A process is provided for deodorizing an aqueous culture broth composition by: (a) providing an aqueous culture broth composition containing odorous compounds in spray form; (b) providing a stream of superheated steam; (c) providing a spray zone in vacuo; (d) simultaneously introducing both the aqueous composition of (a) and the superheated steam into the spray zone causing the odorous compounds to be entrained in the superheated steam, thus forming a deodorized aqueous culture broth composition; (e) removing the superheated steam containing the entrained odorous compounds from the spray zone; and (f) discharging the deodorized aqueous culture broth composition from the spray zone. Preferably, the culture broth composition is maintained at a temperature of less than 50° C. in the spray zone to prevent inactivation of temperature-sensitive materials such as enzymes. Pressure in the spray zone may be about 10 to 250 mbar and temperature of the superheated steam can be up to 250° C. The superheated steam may be introduced into the spray zone countercurrent to the culture broth composition. The deodorized culture broth composition can be recycled to the spray zone for further deodorization. | 2 |
CROSS REFERENCE TO RELATED APPLICATIONS
Applicants claim priority under 35 U.S.C. 119 of German Application No. DE 10 2007 002 986.3 filed Jan. 19, 2007 and German Application No. DE 10 2007 039 726.9 filed Aug. 22, 2007.
BACKGROUND OF THE INVENTION
1. Field of the Invention
The invention relates to a feed converter system for small wind energy systems.
2. The Prior Art
Inverter devices are known from the photovoltaic sector, with which the direct voltage obtained from photo cells can be converted into alternating voltage of a suitable number of volts for the operation of household appliances, for example, or for feed into the power network. Such devices from the photovoltaic sector are usually also used in connection with small wind energy systems, since devices specifically developed for small wind energy systems are often not economically efficient. However, since the wind energy systems are generally equipped with alternating current generators, a rectifier has to be additionally disposed between generator and inverter, in contrast to photovoltaic systems, in order to convert the alternating current having variable frequency, generated by the generator, into an alternating current having a constant frequency of 50 Hz or 60 Hz, which is suitable for being fed into the power network. However, such a combination of devices is complicated during installation, and is not easily manageable, because of the need for different devices. In addition, there is the fact that the small wind energy systems require additional load resistors for start-up or as over-voltage protection, so that at least one additional device is added, further increasing the aforementioned disadvantages.
SUMMARY OF THE INVENTION
It is therefore an object of the invention to provide a feed converter system for small wind energy systems that can be produced and installed in economically efficient manner, and allows the most economically efficient operation of the wind energy system.
This object is accomplished by a feed converter system comprising a rectifier device and an inverter device disposed in a housing, and a common control device for regulating the system components under different load cases, particularly when the wind energy system starts up, or when it is being operated at an optimal operating point. Because of the accommodation of rectifier and inverter in a single housing, a single device is obtained, which can be installed in particularly simple manner, and makes available the required functions for feed of the current obtained in the wind energy system into the power network. The common control device ensures that the feed converter system adapts to all the significant operating states of the wind energy system, and guarantees optimized start-up of the wind energy system, in particular, and setting of an optimal operating point during normal operation.
In an embodiment of the invention, the control device is configured to regulate the system components as a function of the measurement variables of voltage and/or current, as well as their frequency, and/or the speed of rotation of a synchronous generator of the wind energy system. Taking the aforementioned parameters into consideration allows the best possible adaptation to all the operating states.
If a load resistor that serves for start-up of the wind energy system and/or for over-voltage protection is integrated into the housing of the feed converter system, the compactness and simple manageability of the system is further improved. Optionally, the load resistor can be broken up into an internal load resistor having a low power, for over-voltage protection, and an external load resistor having a greater power. Optimally, the external load resistor can be air-cooled or water-cooled.
In an embodiment of the invention, a fan is integrated into the housing of the feed converter system, which only circulates the air within the housing, whereby the device cooling takes place by means of external natural air convection. This measure allows a sealed housing without ventilation openings, thereby resulting in a better type of protection of the feed converter system according to IP65.
In an embodiment of the invention, the control device is connected with consumers by way of an interface, and comprises consumption management that regulates the flow of energy from the wind energy system to the consumers and/or into the power network, or from the power network to the consumers, as a function of the operating state of the wind energy system. The consumption management is preferably integrated into the control device in the form of a computer program. In the case of low or no wind, it allows purchase of power from the power network to feed the consumers. As soon as the wind energy system supplies sufficient power, the consumers are then switched over for operation on the house power network. If less power is available than the consumers need, the power additionally required is purchased from the public power network. If more power from wind energy is available than the consumers need, the excess energy is fed into the power network.
In a further development of the measure last described, it is provided that the interface between control device and consumers comprises radio transmission of the control and regulation signals. In this embodiment, it is possible to do without laying signal lines. The electronics for radio transmission are, of course, also integrated into the same housing as the other components of the feed converter system. Preferably, the radio standard Zigbee 805.3 is used.
In an embodiment of the invention, a measurement point is provided in the transition region between a house network and the power network of a utility company, which point is connected with the control device by way of a data channel and transmits data concerning the power flow at the transfer point over this channel. Using the data of this measurement point, the electricity consumers in the house, which can be added and regulated, can be regulated in such a manner that the maximal electric power is used up in the house itself, and not fed into the power network.
In a particularly cost-advantageous and advantageous embodiment, the load resistor can be added as an additional consumer, to prevent the feed of excess energy into the power network, and the heat that occurs at the load resistor can be used for heating hot water or for heating. In this manner, the load resistor that otherwise serves for start-up of the wind energy system or as over-voltage protection, which is present in any case, is additionally utilized, without the need for the installation of a separate consumer. Of course, this utilization is only practical if the excess energy can be used in the house in a useful manner, instead of being fed into the power network. Here, heating hot water or heating the house by means of the heat that occurs at the load resistor is a useful effect.
In a further development of the invention, a heat pump can be added as an additional consumer, to avoid the feed of excess energy into the power network, and the heat pump can be used for heating or cooling. In contrast to the use of the load resistor as an additional consumer, the heat pump is more complicated in terms of design, but yields a greater benefit than the load resistor, because more heat is available for heating, and cooling is also possible.
The aforementioned embodiment can be further improved if the heat pump is disposed directly on the direct current intermediate circuit of the feed converter, by way of an inverter, and can be regulated by means of the control device. In this way, the losses that otherwise occur during the further conversion of the electrical energy can be saved.
As a further improvement of the invention, it is proposed that the control device is programmed in such a manner that it allows a deviation from the optimal operating point for a short time, during rapid increases of the speed of rotation or of the output of the synchronous generator, and then slowly returns to the optimal operating point. If the speed of rotation or the output of the synchronous generator increases relatively rapidly, this is generally attributable to wind gusts. However, since wind gusts generally last only a short time, it might not be advisable to add additional consumers in order to absorb the additional energy flow. If the control device now permits a higher speed of rotation, for a short time, than at the optimal operating point, the additional energy contained in the wind gusts is temporarily stored as rotation energy of the rotor of the wind energy system. Afterwards, this additional energy is slowly used up, in that the control device slowly regulates the speed of rotation down, until the optimal operating point has been reached again. This inventive measure allows continuous, uniform utilization of the electric energy for consumers that are classified as having a higher value, for some reason, but whose power consumption is limited in an upward direction. The measure according to the invention therefore allows preferring the “higher-value consumers” over the other consumers.
BRIEF DESCRIPTION OF THE DRAWINGS
Other objects and features of the present invention will become apparent from the following detailed description considered in connection with the accompanying drawing. It is to be understood, however, that the drawing is designed as an illustration only and not as a definition of the limits of the invention.
FIG. 1 shows a block schematic with a feed converter system according to the invention.
DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENT
Referring now in detail to the drawing, housing 1 of a feed converter system according to the invention is shown by means of a dotted line. A rectifier 2 and an inverter 3 are integrated into the housing 1 , and are connected with one another by way of a direct current intermediate circuit 26 . Furthermore, a load resistor 4 is disposed in the housing 1 , and electrically connected with the other system components. A control device 5 , which is also disposed in the housing, serves for control. Finally, housing 1 also comprises a fan 6 , with which the air in the interior of housing 1 is circulated. This guarantees that the heat is removed from electric system components 2 , 3 , 4 , 5 and transported to the inside wall of housing 1 . The ambient air flows around housing 1 on the outside, and thereby cools it.
Inverter 3 of the feed converter system is connected with electricity consumers 9 of a residence, on the one hand, and with power network 10 , on the other hand, by way of electricity lines 7 , 8 . An electricity meter 11 is disposed in the immediate vicinity of the connection to power network 10 . Furthermore, additional consumers 12 , 13 can optionally be added at electricity lines 7 , 8 . For this purpose, each consumer 12 , 13 has a switch 14 , 15 assigned to it. Switches 14 , 15 are connected with a consumption management of control device 5 by way of a radio interface indicated with broken line 16 .
During normal operation of the wind energy system, the alternating current generated by a synchronous generator of the wind energy system, which has a variable frequency, depending on the speed of rotation of the rotor of the wind energy system, flows to the rectifier 2 by way of the feed line 17 . There, the alternating current having a variable frequency is rectified. Load resistor 4 serves as protection against over-voltage, and is also needed when the wind energy system starts up from a standstill. The direct current obtained in this manner is converted to an alternating current having a constant frequency of 50 H, in inverter 3 , and regulated to a voltage of 230 V. Electric power 18 (P wind ) that comes from the wind energy system and is converted in feed converter system gets to electricity consumers 9 of the residence by way of electricity lines 7 , 8 .
If a minimal electric power 18 from wind energy to be parameterized is available, the optional consumers 20 are released for operation. Depending on the programming of the consumption management in control device 5 , the latter adds any desired number of additional consumers 12 , 13 by means of switches 14 , 15 . If the wind energy is not completely used up by optional consumers 12 , 13 and non-switchable household consumers 9 , the excess energy is fed into power network 10 .
If the wind energy system cannot make as much electric power 18 available as needed, the consumption management turns the optional consumers off. In this connection, control device 5 takes into consideration operating variables such as speed of rotation, frequency, voltage, and current of the generator of the wind system.
Furthermore, a measurement point 23 is disposed in the region of a transfer point 25 between the local house network and power network 10 of the utility company. Measurement point 23 is connected with control device 5 by way of a data channel 24 . Data channel 24 can be configured as a cable, but also without a cable, particularly as a radio connection. By means of measurement point 23 , control device 5 constantly receives current data about the power P purchase purchased from power network 10 and the power P feed fed into power network 10 , so that the power flows can be regulated by means of program-controlled reactions of control device 5 .
Accordingly, while only a few embodiments of the present invention have been shown and described, it is obvious that many changes and modifications may be made thereunto without departing from the spirit and scope of the invention.
REFERENCE SYMBOL LIST
1 housing
2 rectifier
3 inverter
4 load resistor
5 control device
6 fan
7 electricity line
8 electricity line
9 electricity consumer
10 power network
11 electricity meter
12 consumer
13 consumer
14 switch
15 switch
16 broken line/radio interface
17 feed line from the generator of the wind energy system
18 electric power from wind energy system Pwind
19 electric power for residence Phouse
20 electric power for optional consumer(s) Poptional
21 electric power from the power network Ppurchase
22 electric power into the power network Pfeed
23 measurement point
24 data channel
25 transfer point
26 direct current intermediate circuit | A feed converter system for small wind energy systems has a rectifier device and an inverter device disposed in a housing, and a common control device is provided for regulating the system components under different load cases, particularly when the wind energy system starts up, or when it is being operated at an optimal operating point. | 5 |
The present invention relates to the preparation of pharmaceutical active ingredients, and in particular to the preparation of medicaments active in the treatment of Parkinson's disease.
PRIOR ART
Alkaloids having an ergoline structure exhibit a wide spectrum of biological effects which include both peripheral effects (vasoconstrictor and contractile effect on the smooth muscle of the uterus) and effects on the central nervous system (various sites of action are located in vasomotor centres and cardiac inhibitor centres found in the medulla oblongata and in sympathetic structures found in the diencephalon).
Some of those alkaloids, such as ergotamnine, ergometrinc, ergosine, crgocrystine and ergocryptine, are entirely of natural origin because they can be isolated from the fungus Claviceps purpurea . That fungus is a member of the class of Ascomycetes which is capable of infesting many cereals, such as rye, barley and wheat; its sclerotium contains a high percentage (0.5-0.8% by weight) of alkaloids having an ergoline structure which are responsible for its known toxic properties. Other compounds are of a semi-synthetic nature and are prepared by chemical modification of naturally occurring alkaloids having an ergoline structure. Noteworthy among the above-mentioned semi-synthetic derivatives are bromocryptine, [CAS 25614-03-3], lysuride [CAS 18016-80-3) and pergolide (FIG. 1 ), namely (8)-8-[(methylthio)methyl]-6-propylergoline [CAS 66104-22-1]; this last-mentioned compound in particular is a semi-synthetic ergoline used in therapy for the treatment of Parkinson's disease
The processes for the synthesis and purification of that molecule are described in U.S. Pat. No. 4,166,182 and U.S. Pat. No. 5,463,060; those patents, however, describe synthetic approaches which, according to the authors themselves, are not entirely satisfactory from several points of view. The impurities which arise during the synthesis processes described in U.S. Pat. No. 4,166,182 and U.S. Pat. No. 5,463,060 are difficult to remove without significant losses in yield (J. Kennedy et al., Org. Process Res. Dev. (1997), 1(1), 68-71); furthermore, the process described in U.S. Pat. No. 4,166,182, has low yields and requires long operating times (J. W. Misner et al., Book of Abstracts, 210th ACS National Meeting, Chicago, Ill., Aug. 20-24 (995). Publisher: American Chemical Society, Washington, D.C.).
To be more precise, U.S. Pat. No. 4,166,182 describes the synthesis of pergolide mesylate with 22% yields starting from D-8-methoxycarbonylergoline. The synthesis and chromatographic purification steps make the process particularly complicated; the basic pergolide, obtained with a 38% yield starting from D-8-methoxycarbonylergoline, also requires a further purification step by salification using methanesulphonic acid.
U.S. Pat. No. 5,463,060, on the other hand, describes the synthesis of the basic pergolide starting from 8,9-dihydroelymoclavine with 90.8% yields and with a titre of 94.1%. 8,9-dihydroelymoclavine (CAS 18051-16-6) is, however, a semi-synthetic alkaloid derivative which is not readily available because it is obtained from lysergic acid by means of numerous synthesis steps (see, for example: HU 89-3223 890627; R. Voigt et al. Phanirazie (1973), 2; S. Miroslav et al. Collect.Czech.Chem.Commun. (1968), 33(2), 577-82); the synthetic steps necessary to carry out the above-mentioned conversion arc also especially onerous because they require, inter alia, stereoselective hydrogenation of the double bond in the 9,10 position and the reduction of the 8 carboxylic function to an alcoholic function (upon conversion into methyl ester).
The object of the present invention is therefore to provide an alternative process for the production of pergolide which permits yields and purities higher than those of U.S. Pat. No. 4,166,182 and which uses a starting compound which is more readily available than 8,9-dihydroelymoclavine.
SUBJECT-MATTER OF THE INVENTION
Medicaments active in the treatment of Parkinson's disease which can be prepared in accordance with the process of the present invention comprise products which have the following general formula VI:
wherein R 4 may be, independently, a linear, branched or cyclic, saturated or unsaturated C 1-8 alkyl radical, such as, for example, the radicals methyl, ethyl, propyl, butyl, isobutyl, tert-butyl, pentyl, cyclopentyl, hexyl, cyclohexyl and octyl; the preferred compound includes, but is not limited only to, the pergolide (R 4 =CH 3 ).
The process for the synthesis of those compounds, which forms the main subject of the present invention, uses as starting material the compound of formula I given below, wherein R 1 represents a linear, branched or cyclic, saturated or unsaturated C 1-8 akyl residue, preferably methyl, ethyl, propyl, butyl, isobutyl, tert-butyl, pentyl, cyclopentyl, hexyl, cyclohexyl and octyl, and even more preferably methyl, or the well known and readily available D-8-methoxycarbonylergoline [CAS 30341-92-5].
In that process, the compounds of formula I are reacted with 3-halo- and/or 2-halo-propionyl chloride in an aprotic organic solvent in the presence of a suitable proton acceptor. Solvents that may be used in that step are preferably selected from acetone, methyl ethyl ketone, tetrahydrofuran and dimethylformamide; the proton acceptor is preferably selected from triethylaniine, pyridine and lutidine. Both the proton acceptor and the 3-halo- and/or 2-halo-propionyl chloride are preferably used in equimolar amounts relative to the compound of formula I.
The compound or mixture of compounds IIa and IIb so obtained is then reacted with calcium borohydride in an amount of preferably from 5 to 9 moles/mole of substrate in tetrahydrofuran. The tetrahydrofuran is preferably present in an amount of from 2 to 8 ml per gram of substrate; optionally, it may be used in admixture with protic organic solvents, such as methanol, ethanol or isopropanol, or with an aqueous-alcoholic solution thereof. The reaction is carried out at a temperature of from 10 to 65° C., preferably at 60° C.
Compound III so obtained is then reacted in an aprotic organic solvent with an alkylsulphonyl chloride in the presence of a proton acceptor at a temperature of preferably from 10 to 30° C.; the proton acceptors are preferably selected from pyridine, triethylaniine, lutidine; the alkylsulphonyl chlorides are preferably selected from methanesulphonyl chloride, ethanesulphonyl chloride and p-toluenesulphonyl chloride. The proton acceptor and the alkylsulphonyl chloride are preferably used in amounts of from 20 to 30 and from 1.2 to 3 moles/mole of substrate, respectively.
Compound IV so obtained is then reacted in an aprotic organic solvent with a compound of the general formula R 4 SX, wherein R 4 is a linear, branched or cyclic, saturated or unsaturated C 1-8 alkyl residue, preferably methyl, and X is an alkali metal, preferably sodium. The compound R 4 SX is preferably used in an amount equal to 4-8 equivalents relative to the substrate; the apolar organic solvent is preferably dimethylformamide; the reaction is preferably carried out at a temperature of from 90 to 100° C.
Finally, compound V so obtained is converted into the desired end product by treatment with a reducing agent in an aprotic organic solvent at a temperature of preferably from 20 to 45° C. Reducing agents that may be used in that step are preferably selected from lithium aluminium hydride and sodium dihydro-bis(2-methoxyethoxy)aluminate; aprotic solvents that may be used in that step are preferably selected from tetrahydrofuran, dioxane and toluene.
For greater clarity, the novel process according to the present invention is shown in the following reaction schemes 1, 2 and 3.
wherein R 1 represents a linear, branched or cyclic, saturated or unsaturated C 1-8 alkyl residue, such as, for example, the radicals methyl, ethyl, propyl, butyl, isobutyl, tert-butyl, pentyl, cyclopentyl, hexyl, cyclohexyl and octyl, preferably a methyl group; R 2 is a halogen (Cl, I, Br), preferably chlorine (Cl), X is an iodine molecule or a compound of the general formula R 5 SO 3 wherein R 5 is methyl, ethyl or p-tolyl, preferably methyl; R 4 is, independently, a linear, branched or cyclic, saturated or unsaturated C 1-8 alkyl residue, such as, for example, the radicals methyl, ethyl, propyl, butyl, isobutyl, tert-butyl, pentyl, cyclopentyl, hexyl, cyclohexyl, preferably a methyl group.
wherein R 1 , R 2 , R 4 and X have been defined above.
wherein R 1 , R 4 and X have been defined above.
The novel intermediates of formula II, III, IV and V, which are given individually below for greater clarity, constitute a further subject of the invention.
wherein R 1 and R 3 may be a halogen (Cl, I, Br) and hydrogen (H), respectively; alternatively, R 2 and R 3 may be bonded to one another directly giving rise to a double bond; and R 1 represents a linear, branched or cyclic, saturated or unsaturated C 1-8 alkyl residue, such as, for example, the radicals methyl, ethyl, propyl, butyl, isobutyl, tert-butyl, pentyl, cyclopentyl, hexyl, cyclohexyl and octyl; the preferred molecules are represented by the compounds IIa (R 3 =H; R 2 =Cl; R 1 =CH 3 ) and IIb (R 3 and R 2 joined together to give rise to a double bond; R 1 =CH 3 ).
wherein X is a halogen (X=I, compound IVb) or a compound of the general formula R 5 SO 3 — wherein R 1 is methyl, ethyl or p-tolyl; the preferred molecule is represented by the compound IVa(X=CH 3 SO 3 —).
wherein R 4 is, independently, a linear, branched or cyclic, saturated or unsaturated C 1-8 alkyl residue, such as, for example, the radicals methyl, ethyl, propyl, butyl, isobutyl, tert-butyl, pentyl, cyclopentyl, hexyl, cyclohexyl; the preferred molecule is represented by the compound Va (R 2 =CH 3 ).
DETAILED DESCRIPTION OF THE INVENTION
In order to obtain quantitative conversion of the 8-methoxycarbonylergoline into the intermediate III, a series of acylating agents, such as 3-halo- and 2-halo-propionyl chlorides, were evaluated. The halogen derivatives tested were chlorine, iodine and bromine derivatives.
As is well known to experts in the field, the presence of an electron-attracting group (such as a chlorine, bromine or iodine atom) in the alpha or beta position to an acid chloride increases the latter's reactivity in acylation reactions.
During the research work which led to the present invention, it was hoped to find, by screening reducing agents, a reagent which exhibited a high degree of chemoselectivity towards the intermediate chlorine derivative of formula II (R 2 =alogen, R 2 =H or R 2 =H, R 2 =halogen). The reducing agent was intended to replace the halogen in the alpha (or beta) position to the acylamide function with a hydrogen atom and reduce the methoxycarbonyl function in the 8 position to an alcoholic function without reducing the amide group in position 6.
We ascertained experimentally that by using an equimolar amount of 3-chloropropionyl chloride in the presence of a proton acceptor in acetone solution under stirring at room temperature, D-8-methoxycarbonylergoline gave, in addition to the desired product (D-6-(3′-chloropropionyl)-8-methoxycarbonylergoline; compound IIa), a side product which was subsequently identified as D-6-(acryloyl)-8-methoxycarbonylergoline (compound IIb). The presence of this side product IIb was initially regarded as a critical factor for the industrial development of the process because, even if the presence of compound IIb could be contained by suitably varying the experimental conditions (slow addition of the acylating agent, low reaction temperatures, low concentrations of the reagents) nothing was known of the possible influence of that secondary product on the subsequent synthetic steps.
Surprisingly, the screening carried out on a number of reducing agents under various experimental conditions on a mixture constituted to the extent of 50% by compound IIb and compound IIa demonstrated not only that calcium borobydride in tetrahydrofuran was capable of showing the desired chemoselectivity (removal of the chlorine in position 3′ and reduction of the 8-methoxycarbonyl group without reducing the amide in position 6) but also that compound IIb was converted into the desired compound of formula III.
The surprising reactivity of the double bond of compound rib with calcium borohydride in tetrahydrofuran gave us the possibility, which was not foreseeable from the literature, of using the reaction mixture obtained directly from the acylation reaction of D-8-methoxycarbonylergoline without purification in the subsequent reaction step.
Thus, by reacting a mixture of D-8-methoxycarbonylergoline in an aprotic solvent, in concentrations ranging from 8 to 18% weight/volume, under stirring at room temperature, with an equimolar amount of a suitable proton acceptor and one equivalent of 3-halo- or 2-halo-propionyl chloride for a period ranging from 30 minutes to 2 hours, we obtained, after dilution with water and filtration, a mixture of which approximately 50% was constituted by compound IIa and compound IIb.
Aprotic solvents that may be used in that step are represented by acetone, methyl ethyl ketone, tetrahydrofuran, dimethylformamide, preferably acetone; proton acceptors that may be used are triethylamine, pyridine and lutidine, preferably triethylamine.
The mixture of compound IIa and compound IIb is dispersed in tetrahydrofuran with sodium borohydride (from 5 to 9 moles per mole of substrate) and the suspension so obtained is added, at a temperature ranging from 0 to +15° C. and under vigorous stirring, to a tetrahydrofaran solution or to an alcoholic solution (methanol, ethanol or isopropanol) or an aqueous-alcoholic solution containing calcium chloride (from 1.5 to 2 moles per mole of sodium borohydride). When the addition is complete, the temperature is increased to 60° C. and the reaction mixture is maintained under stirring for a period ranging from 20 minutes to 60 minutes. The compound III so obtained is precipitated from the reaction mixture (after acidification of the reaction mixture, evaporation of the organic phase and treatment with aqueous carbonate) and recovered by filtration.
Alternatively, the calcium borohydride, instead of being produced “in situ”, can be used already preformed in the commercially available forms (for example, as a bis-THF complex).
On the basis of the data obtained, compound III can be prepared in accordance with Scheme 1 with total yields of 81% starting from D-8-methoxycarbonylergoline.
It was clear from the results obtained that, in order to synthesise the compound of formula III, it would have been equally advantageous to acylate compound I directly with acryloyl chloride (Scheme 3) or to use the intermediate IIa with a high degree of chemical purity (obtainable by the acylation of compound I with chloropropionyl chloride carried out at low temperatures (0-5° C.) and high dilutions (0.05-0.2 molar); Scheme 2) and to reduce the intermediate IIb or IIa so obtained with calcium borohydride in the next step. An experimental check carried out on those two variants confirmed total yields of compound III from compound I superimposable on those obtained by synthesis Scheme 1, confirming the validity thereof as alternatives for obtaining compound III.
Compound III was subsequently reacted, in solution with a proton acceptor, with an alkylsulphonyl chloride under stirring at room temperature for a period ranging from 1 to 2 hours to give compound IV (X=R 5 SO 3 ; wherein R 5 is methyl, ethyl or p-tolyl) with yields ranging from 88 to 95%.
Suitable proton acceptors are represented by pyridine, triethylamine, lutidine, preferably pyridine. Alkylsulphonyl chlorides that may be used are represented by, but not limited to, methanesulphonyl chloride, ethanesulphonyl chloride or p-toluenesulphonyl chloride, preferably methanesulphonyl chloride.
Compound IVa is then treated with from 4 to 8 equivalents of sodium alkyl mercaptide (compound of the general formula R 4 SNa; wherein R 4 is. independently, a linear, branched or cyclic, saturated or unsaturated C 1-8 alkyl residue) in dimethylformamide with agitation at from 90 to 100° C. for a period ranging from 2 to 5 hours to give compound V with yields ranging from 90 to 95% and an HPLC titre of 97%.
If the R 4 group of the allyl mercaptide is an alkyl radical larger than methyl or ethyl, compound IVa (X=R 5 SO 3 ; wherein R 5 is methyl, ethyl or p-tolyl) can be converted beforehand into a halogenated derivative IVb (preferably X=I) in order to facilitate nucleophilic substitution. That last step is carried out in acetone solution with agitation at reflux temperature in the presence of lithium iodide to give compound IVb in quantitative yields.
Compound V is converted into the final compound VI by treating a heterogeneous mixture of compound V in an aprotic solvent with a reducing agent at a temperature ranging from 20 to 45° C. for from 2 to 6 hours. Reducing agents that may be used in that step are lithium aluminium hydride or sodium dihydrido-bis(2-methoxyethoxy)aluminate; the preferred reducing agent is sodium 7dihydridro-bis(2-methoxyethoxy)aluminate. Aprotic solvents that may be used in that step are tetrahydrofuran, dioxane and toluene; the preferred solvent is toluene. The yields of that step are from 80 to 99%.
The physico-chemical characteristics of the product VI obtained (R 4 =CH 3 ) are in good agreement with the data reported in literature for this product; the HPLC purity is 96%.
The high degree of purity of the pergolide base obtained (HPLC titre of 96% on the crude reaction material), the high global yields of the process (66%) starting from D-8-methoxycarbonylergoline and the ready availability of the primary starting material make this process competitive compared with those known from the prior art.
Several salts of compound VI (Pergolide) may be prepared, including acid addiction salts of inorganic acids as well as salts derived from non toxic organic salts. The preparation of the above salts, and particularly the methanesulfonate (mesylate), may be easily realised following known literature procedures, as for example U.S. Pat. No. 4,166,182 and EP-0003667, herein incorporated as references.
EXAMPLES
Example 1
Preparation of D-6-n-propionyl-8-hydroxymethylergoline (Compound III) According to Reaction Scheme 1
A mixture of D-8-methoxycarbonylergoline (compound 1) (10.8 g; 0.04 mol) is heated with vigorous agitation in acetone (100 ml) at 40° C. for 30 minutes, and then at 55° C. for a further 30 minutes. After cooling to ambient temperature, triethylamine (0.04 mol) is added. After a few minutes, a solution of 3-chloropropionyl chloride (5.08 g; 3.84 ml; 0.04 mol) in acetone (5 ml) is added dropwise while maintaining the reaction temperature at from 20 to 25° C. When the addition is complete, the reaction mixture is maintained under stirring at room temperature for 30 minutes, then it is poured into water (150 ml) and the suspension so obtained is maintained under stirring for 30 minutes. After that time, the precipitated solid is recovered by filtration, washed with water (100 ml) and dried overnight under vacuum at a temperature of 60° C. to give 12.8 g of a 6/4 mixture of compound IIa and compound IIb.
For analysis purposes, the two compounds IIa and IIb can be isolated by chromatography on silica gel while eluting with dichloromethane/methanol=9/1.
D-6-(3′-chloropropionyl)-8-methoxycarbonylergoline (Compound IIa):
TLC=R f ; 0.72 (eluant dichloromethane/methanol=9/1); 1 H-NMR (60 MHz, DMSO-d 6 ) gives the diagnostic signals (ppm): 0.50-1.50 (m); 2.10-2.90 (m); 3.30 (s); 2.90-4.00 (m); 6.30-6.75 (m, 4H, aromatic); Elemental analysis: calculated for C 19 H 21 N 2 O 3 Cl; theoretical—C: 63.24%; H:5.87%; N:7.76%; O:13.30%; CI:9.83%; found—C:63.29%; H:5.84%; N:7.67%; Cl:9.88%.
D-6-(acryloyl)-8-methoxycarbonylergoline (Compound IIb)
TLC=R f :0.61 (eluant dichloromethane/methanol=9/1) MS(EI)-M + : m/e=324; 1 H-NMR (60 MHz, DMSO-d 6 ) gives the diagnostic signals (ppm): 2.15-2.40 (m, 3H); 2.40-3.20 (m, 3H); 3.25 (s, 3H, CO 2 CH 3 ); 3.60-3.70 (m, 3H); 5.35-5.70 (m, 2H, CH 2 ═CH); 6.15 (m, 1H, CH 2 ═CH); 6.30-7.15 (m, 4H, aromatic); 9.25-9.50 (sb, 1H, N—H); Elemental analysis calculated for C 19 H 20 N 2 O 3 ; theoretical—C:70.35%; H:6.21%; N:8.64%; O:14.80%; found—C:70.31%; H:6.26%; N:8.73%.
The mixture of compounds IIa and IIb (1 g), which are obtained directly from the previous reaction, is dispersed in tetrahydrofuran (4 ml) with sodium borohydride (870 mg). The suspension so obtained is added, under vigorous stirring at a temperature of 10° C., to a solution constituted by calcium chloride (14.5 mmol) in ethanol (16 ml). When the addition is complete, the temperature of the reaction mixture is slowly increased to 60° C. and the mixture is maintained under stirring at that temperature for 30 minutes. After that time, the reaction mixture is concentrated under vacuum and the residue so obtained is acidified with 2N HCl; the suspension so obtained is maintained under stirring for 1.5 hours at ambient temperature and then the precipitate is recovered by filtration. The solid so obtained is resuspended in methanol (8 ml); the heterogeneous mixture is heated to reflux temperature and is maintained at that temperature for 10 minutes. When the suspension has been cooled to 15° C., a 10% (15 ml) potassium carbonate solution is added with vigorous stirring. The crystalline solid so obtained is recovered by filtration, washed with a large amount of water and dried under vacuum at a temperature of 60° C. to give 965 mg of compound III (81% total yield from compound I).
TLC=R f : 0.55 (eluant dichloromethane/methanol=9/1) Melting point: 214-216° C.; MS(EI)-M + : m/e=298; 1 H-NMR (60 MHz, DMSO-d 6 ) gives the diagnostic signals (ppm): 0.85-1.25 (t, 3H, CH 3 CH 2 C═O); 2.15-2.80 (m); 2.85-4.00(m); 4.55-4.85 (sb, 1H, O—H); 6.35-7.05 (m, 4H, aromatic); 10.25-10.50 (sb, 1H, N—H).
Example 2
Preparation of D-6-(propionyl)-8-mesyloxymethylergoline (Compound IVa)
Methanesulphonyl chloride (0.962 g) is added slowly to a solution of compound III (0.984 g) and pyridine (5.900 g) under vigorous stirring and while maintaining the reaction temperature comprise between 15 and 20° C. When the addition is complete, the reaction mixture is maintained under stirring at room temperature for 1 hour, then it is worked up by adding a 10% aqueous solution of potassium carbonate (15 ml) and continuing agitation until a crystalline solid is obtained which is recovered by filtration, washed with a large amount of water and dried under vacuum at 60° C. to give 1.091 g of compound IV (88% yields). HPLC (Column: LICHROCART 125×4 mm packed with LICHROSPHER RP-18, 5 m; mobile phase: 60% buffer 20 mM of K 2 HPO 4 adjusted to pH 6.5 using H 3 PO 4 (85%) and 10 mM triethylamine; 40% acetonitrile; flow 1.2 ml/minute): rt 4′266″. Elemental analysis calculated for C 19 H 24 N 2 O 4 S theoretical—C:60.62%; H:6.43%; N:7.44%; O:17.00%; S:8.52%; found—C:60.66%; H:6.49%; N:7.45%; S:8.48%.
Example 3
Preparation of D-6-(propionyl)-8-methylthiomethylergoline (Compound V)
Compound IV (1.091 g) is suspended in anhydrous dimethylformanide (6.825 g) and the reaction mixture so obtained is heated (60-80° C.) under stirring until a homogeneous solution is obtained. After cooling to ambient temperature, a 20% solution of sodium methyl mercaptide (5.250 g) in methanol is added rapidly under vigorous stirring. After 1 hour, the reaction mixture is slowly heated until a temperature of 90-95° C. is reached, distilling off all of the methanol. The reaction mixture then continues to be heated under vigorous stirring for 4 hours. The reaction mixture is cooled to 10° C. and 7.5 ml of water are added under stirring. The precipitated product is recovered by filtration, washed with water and dried under vacuum at a temperature of 60° C. to give 0.905 g of compound V (95% yield).
TLC=R f :0.81 (eluant dichloromethane/methanol=9/1); HPLC (same experimental conditions as in Example 2)=rt:11′070″; Melting point:268° C. (decomposition); Elemental analysis calculated for C 19 H 24 N 2 OS; theoretical—C:69.48%; H:7.36%; N:8.53%; O:4.87%; S:9.76%; found—C:69.51%; H:7.31%; N:8.48%; S:9.78%.
Example 4
Preparation of D-6-n-propyl-8-methylthiomethylergoline (Compound VI)
4.0 g of a 70% solution of sodium dihydridro-bis(2-methoxyethoxy)aluminate in toluene are added slowly to a suspension of compound V (0.905 g) in toluene (13.8 ml) under stirring at room temperature. When the addition is complete, the reaction is maintained under stirring for 1 hour then heating to a final temperature of 45° C.; this temperature is maintained for 4 hours. At the end of that time, the reaction mixture is cooled to ambient temperature and acidified with 5% HCl (25 ml). The two-phase mixture is distilled under vacuum until the organic phase has been eliminated; the aqueous suspension which remains is filtered under vacuum and the solid so recovered is washed with water. The crude material so obtained is resuspended in methanol (6 ml) and the suspension so obtained is heated under reflux for 30 minutes, then cooled to room temperature and treated with a 10% aqueous solution of potassium carbonate (12 ml) under vigorous stirring. After 2 hours under stirring at room temperature, the suspension is filtered and the solid so recovered is washed with water and dried under vacuum at a temperature of 60° C. to give 0.826 g of compound VI (95% yield).
The physico-chemical characteristics of the product obtained are in good agreement with the literature data (as reported in U.S. Pat. No. 4,166,182). The HPLC titre (same experimental conditions as those given in Example 2) of compound VI so obtained (rt 11′070″) is 96%.
Example 5
Preparation of D-6-(propionyl)-8-hydroxymethylergoline (Compound III) According to Reaction Scheme 3
5 g (18.49 mmol) of D-8-methoxycarbonylergoline (Compound I) are dispersed in acetone (50 ml) and the reaction mixture is heated at 40° C. for 30 minutes and then at 55° C. for a further 30 minutes. After cooling to ambient temperature, triethylamine (2.24 g; 3.1 ml; 22.18 mmol) and a solution of acryloyl chloride (2 g; 1.8 ml; 22.18 mmol) in acetone (5 ml) are added in succession while maintaining the reaction temperature comprise between 20 and 25° C. When the addition is complete, the reaction mixture is maintained under stirring at room temperature for 1 hour. The reaction mixture is worked up by being poured into water (100 ml) and maintaining the resulting suspension under stirring for 30 minutes. After that time, the precipitated solid is recovered by filtration, washed with water (80 ml) and dried under vacuum at a temperature of 60° C. to give (5.4 g; 16.64 mmol; 90% yield) of compound IIb.
The physico-chemical characteristics of the resulting product IIb are the same as those of the product obtained by chromatographic purification in Example 1. Compound IIb is then reduced using calcium borohydride produced “in situ”, as already described in Example 1, to give compound III with total yields of 78% starting from compound I.
Example 6
Preparation of D-6-(propionyl)-8-hydroxymethylergoline (Compound III) According to Reaction Scheme 2
A mixture of D-8-methoxycarbonylergoline (Compound I) (3.48 g; 12.9 mmol) is heated, under vigorous stirring in acetone (65 ml) at 40° C. for 30 minutes and then at 55° C. for a further 30 minutes. When the reaction mixture has been cooled to 5° C., triethylamine (13 mmol) is added and, while maintaining that temperature, a solution of 3-chloropropionyl chloride (1.64 g; 1.24 ml; 12.9 mol) in acetone (6.5 ml) is added within a period of 30 minutes under vigorous stirring. When the addition is complete, the reaction mixture is maintained under stirring at room temperature for 30 minutes and then it is poured into water (100 ml), the resulting suspension being maintained under stirring for 30 minutes. After that time, the precipitated solid is recovered by filtration, washed with water (35 ml) and dried overnight under vacuum at a temperature of 60° C. to give 3.6 g of compound IIa (contaminated to the extent of 5% with compound IIb). The crude product can be reduced using calcium borohydride produced “its situ” as described in Example 1 to give compound III with total yields, starting from intermediate I, of 80%.
Example 7
Preparation of D-6(propionyl)-8-iodomethylergoline (IVb) Starting From Compound IVa
A mixture constituted by compound IVa (1 mmol; 376 mg) and lithium iodide (4 mmol; 455 mg) in acetone (20 ml) is stirred at reflux for 8 hours. After that time, the reaction mixture is worked up by diluting it with water (20 ml) and recovering the resulting solid by filtration, washing it with a large amount of water on the filter and drying it overnight under vacuum at 60° C. 392 mg (0.96 mmol) of compound IVb are recovered.
MS(EI)-M + : m/e=408; Elemental analysis calculated for C 18 H 21 N 2 OI; theoretical—C:52.95%; H:5.18%; N:6.86%; O:3.92%; I:31.08%; found—C:52.90%; H:5.12%; N:6.81%; I:31.12%. | Process for the preparation of compounds active in the treatment of Parkinson's disease, and such compounds, having general formula (VI) wherein R 4 may be, independently, a linear, branched or cyclic, saturated or unsaturated C 1-8 alkyl radical, such as, for example, the radicals methyl, ethyl, propyl, butyl, isobutyl, tert-butyl, pentyl, cyclopentyl, hexyl, cyclohexyl and octyl. The process utilizes as starting materials the compound of formula (I) wherein R 1 represents a linear, branched or cyclic, saturated or unsaturated C 1-8 alkyl residue. | 2 |
CROSS-REFERENCE TO RELATED APPLICATIONS
Not Applicable
STATEMENT REGARDING FEDERALLY SPONSORED RESEARCH OR DEVELOPMENT
Not Applicable
MICROFICHE APPENDIX
Not Applicable
BACKGROUND OF THE INVENTION
This invention relates to trigger actuated controls for portable electric tools wherein the rotational speed of the motor is controlled as a function of displacement of a trigger actuator. The trigger operator is connected to a movable actuator element of a variable resistor which is connected in circuit with a thyristor, the electric motor of the tool, and a source of electric power. A significant amount of heat is generated by electronic components of such speed control circuits, particularly by the thyristor which switches the electric power. Heat sinks are commonly provided in the control for dissipating the heat. As the electrical ratings of the tools increase, the power increases as does the quantity of heat to be dissipated. It is known to extend an internal heat sink externally of the control housing or to connect the thyristor to an external heat sink or to the case of the tool by a bolted connection or the like. Such practices require modification of the control and/or additional assembly steps to complete the mechanical connection, often performed by the tool manufacturer at the time of assembly of the control to the tool. Either solution generally represents increased cost to the tool manufacturer.
BRIEF SUMMARY OF THE INVENTION
This invention provides a trigger actuated control for controlling the rotational speed of an electric motor of a portable electric tool wherein an external supplemental heat sink may be readily attached to the control. The supplemental heat sink has oppositely directed laterally projecting ribs which are slidably received in complemental grooves on opposite sides of an opening through a wall of the control housing. A projection of the heat sink extends into the control housing to abuttingly engage a primary heat sink contained within the housing. The primary heat sink is contained on a base assembly which is insertable from an open side of the housing in the same direction as is the supplemental heat sink. The supplemental heat sink is positioned in engagement with the primary heat sink while the base assembly is separated from the housing, and the two elements are inserted simultaneously to the control housing. Cooperating structural formations on the supplemental heat sink, the base assembly and the control housing create an interlocking structure which retains the supplemental heat sink attached to the control. Complemental abutting faces of the two heat sinks are formed at an angle to provide a wedging effect for enhanced thermal transfer engagement.
BRIEF DESCRIPTION OF THE DRAWINGS
FIG. 1 is a side elevation view of a trigger actuated control and supplemental heat sink constructed in accordance with this invention.
FIG. 2 is an exploded view similar to FIG. 1 showing a base assembly (with a forward base half removed) and the supplemental heat sink disassembled from the control housing.
FIG. 3 is an elevational view of a switch assembly of the control which is assembled on the back side of the base assembly shown in FIG. 2.
FIG. 4 is an elevational view of a forward base half of the base assembly which is removed from the base assembly shown in FIG. 2.
FIG. 5 is a view similar to FIG. 2 showing the supplemental heat sink assembled to the base assembly and partially inserted into the control housing.
FIG. 6 is a partial cross-sectional view taken along the lines 6--6 of FIG. 1 showing the supplemental heat sink attached to the control housing and in thermal contact with the primary heat sink.
DETAILED DESCRIPTION OF THE INVENTION
A trigger actuated control for controlling the rotational speed of an electric motor is shown in side elevation in FIG. 1. Control 2 is an overhanging trigger styled control comprising a molded insulating frame 4 having a generally rectangular housing 4a open to the bottom surface as oriented in FIG. 1 and a trigger supporting extension 4b at the left-hand end. A trigger operator 6 is pivotally supported at the distal end of the extension 4b by a rivet 8 which passes through the trigger 6 and the extension 4b. Trigger 6 is generally U-shaped in cross section and straddles the extension 4b. Trigger 6 is biased counter-clockwise about the rivet 8 by a helical compression spring 10 disposed between extension 4b and a bight portion of trigger 6. Trigger support extension 4b is provided with a pair of holes 4c for mounting the control in a portable electric tool and a smaller third hole 4d for retaking a supplemental heat sink of this invention assembled to the frame 4 as will be described more fully hereinafter.
Housing portion 4a of frame 4 is open to the bottom for receiving a base assembly of the control. The base assembly comprises two base halves 12 and 14 (FIGS. 2-4) which are positioned together side-by-side creating a sandwich style receptacle therebetween for a printed circuit board 16, heat sink 18 and resistor strip 20 of the speed control circuit. The outside surfaces of the respective base halves 12 and 14 are provided with electric switch components such as stationary contacts 22, 24, movable electrical contacts 26, jumper contact 28 and wiring terminal connectors 30. The base halves with circuit and switch components assembled thereto are positioned together and inserted into the open bottom end of housing portion 4a of frame 4 and are retained therein by bosses 12a and 14a on the outer surfaces of the respective base half moldings which snap into holes 4e at the lower edges of opposite side walls of housing portion 4a. A more complete description of the details of this construction can be found in H. W. Brown U.S. Pat. No. 3,775,576 issued Nov. 27, 1973 and assigned to the assignee of this invention.
The frame 4 and trigger 6 assembly further comprise an actuator 32, shown in dotted lines in FIG. 2, within the housing 4a which has an elongated rod 32a extending through a slot 4f in left-hand end wall of housing 4a to trigger operator 6 where it is pivotally connected to the trigger 6 by a rivet 34. Slider 32 has cam surfaces 32b molded thereon on opposite sides to engage upstanding tabs 26a of movable contacts 26 to depress the appropriate end(s) of the movable contact according to the position of the slider 32. Slider 32 also carries a movable wiper 32c, made from conductive spring material, which engages resistor strip 20 in final assembly of the control. Clockwise depression of the trigger 6 about rivet 8 against the bias of return spring 10 causes rivet 34 to move leftwardly, pulling the carrier 32 leftwardly within the housing 4a by virtue of the connecting rod 32a. In the "at-rest" position of slider 32 against the right-hand end wall of housing 4a, cams 32b engage the tabs 26a to hold movable contact 26 depressed, out of contact with stationary contacts 22, 24. Leftward movement of slider 32 moves the cam surfaces 32b from engagement with the movable contact tabs 26a causing the movable contact to move to the position shown in FIG. 3 wherein the left and right hand ends abut the stationary contacts 22 and 24 respectively, thereby closing the circuit between those stationary contacts. A serpentine spring 36 is disposed within the base half 12 to bear against the underside of movable contact 26, biasing it to the closed position with movable contacts 22 and 24. Although not shown, electric wire leads are insertable into the base halves through appropriate openings 12b and 14b in the respective molded base half to be wedged in electrical engagement against the surface of stationary contacts 22, 24, or 28, thereby permitting the control to be electrically connected to the power supply and to the electric tool motor.
Each base half of the trigger actuated control of this invention may comprise a movable contact switch such as shown in FIG. 3 whereupon a double break switch construction is provided. However, one switch pole may be eliminated in certain applications in favor of a common connector strap such as 28 as shown in FIG. 4. Thus the movable contact 26 and biasing spring 36 are not present in the base half 14.
The integrated circuit 16 comprises a thyristor 38 such as an SCR or a Triac or the like. The substrate of the integrated circuit 16 is thermally bonded to the heat sink 18 which is substantially coextensive with the integrated circuit substrate except for a tab 18a which extends forwardly around the left-hand end of substrate 16 and an upstanding portion 18b which lies adjacent the resistor strip 20. With the control 2 suitably electrically wired to the electric tool motor and power source, the control is electrically connected in circuit with the motor and power source upon initial movement of trigger 6 to cause movable contact 26 to close on stationary contacts 22 and 24. The rotational speed of the tool is controlled by the amount of depression of the trigger operator 6 which causes the slider 32c to move along the resistor strip 20, thereby changing the resistance and the firing angle of the thyristor 38 in a well known manner. Conduction of thyristor 38 generates heat which must be dissipated by heat sink 18. Demands for greater power in electric tools result in higher rated thyristors and generation of more heat. Heat sink 18 may not be adequate to completely dissipate the heat generated by the control.
This invention provides a supplemental heat sink 40 which may be readily attached to the frame 4 and connected to the heat sink 18 during assembly of the base halves 12 and 14 to the frame 4. As seen particularly in FIGS. 2 and 6, the heat sink 40 comprises a rectangular plate of good thermally conductive material such as aluminum which has a pair of oppositely directed vertically extending ribs 40a at the right hand end. A projection 40b extends beyond the ribs 40a and has a widened end portion 40c. The outermost surface 40d of widened end portion 40c is disposed at a shallow angle to be complementary to flange 18a of the heat sink 18. As earlier described, housing portion 4a of frame 4 has a vertically extending slot 4f through the left-hand end wall adjacent extension 4b for assembling the slider 32 and elongated rod 32a into the frame. Vertically extending grooves 4g (FIG. 6) are provided on opposite faces of the slot 4f in the housing for customarily receiving a sealing or closing member for the housing after assembly of the slider 32. Such member is eliminated herein. The supplemental heat sink 40 is assembled to control 2 by inserting projection 40c between the assembled base halves 12 and 14 such that the angled surface 40d abuts the surface of flange 18a of heat sink 18. The base halves and supplemental heat sink are thereafter inserted into the frame from the open end wherein the ribs 40a are slideably disposed within the grooves 4g. Extension 40c is appropriately dimensional to provide a tight interference fit with the flange 18a of heat sink 18 to maintain good thermal engagement therewith. The supplemental heat sink 40 is also provided with a pair of holes 40e which are in corresponding alignment with the holes 4c of the projection 4b for mounting the control 2 to the tool. A boss 40f is disposed between the holes 40e and is received in the hole 4d when the assembly is fully inserted into the frame to provide a further retention for heat sink 40 with the frame 4.
The foregoing describes a structure for readily and effectively increasing heat dissipation capabilities of a rotational speed control for a portable electric tool or the like. Although the invention has been described in conjunction with an overhanging trigger control, it is to be understood that it is readily applicable to other controls, including for example in-line trigger speed controls, and further is susceptible to various modifications without departing from the scope of the appended claims.
Although the invention has hereinabove been described with respect to the illustrated embodiments, it will be understood that the invention is capable of modification and variation and is limited only by the following claims. | A heat sink is slideably attached to a housing of an electronic control, retained by complemental snap-in elements and has a projection extending through a wall of the housing into abutting thermal engagement with an internal heat sink which is in intimate contact with the electronics of the control. | 7 |
This non-provisional application claims priority under 35 U.S.C., §119(a), on Patent Application No. 0309045.3 filed in Great Britain on Apr. 22, 2003, the entire contents of which are hereby incorporated by reference.
BACKGROUND OF THE INVENTION
1. Field of the Invention
The present invention relates to a distributed peripheral device control system and method.
2. Description of the Related Art
A device having the capability to print a document typically requires access to the following information and software: (a) the document data; (b) application software capable of loading and processing the document, together with other data, such as fonts, required to render the document; (c) operating system graphical and printing software, used by the application software to produce output in a displayable form; and (d) device drivers, which are the software modules used by a printing system to produce output suitable to a given type (make and model) of printer; each type of printer may require a different device driver.
These programs and data generally consume large amounts of computer memory and disk space, and preparing the document for printing can require a considerable amount of processing.
A typical mobile information device, such as a Personal Digital Assistant (PDA) or mobile phone, is much more limited in resources and processing speed than a desktop machine, and therefore not capable of locally supporting fully functional printing of most document types. Furthermore, with increased availability of wireless connection technologies, such as IrDA, Bluetooth and wireless LANs, the user of a mobile device potentially has access to a wider range of printers, on an ad-hoc basis.
Hand-held PDAs typically have cut-down document processing and printing capabilities, with limited document-viewer applications and system software using generic, “lowest common denominator” printer drivers. Smaller devices, such as mobile phones, normally have no printing or document processing ability at all.
FIG. 1 of the accompanying drawings shows a typical arrangement for printing from a personal computer (PC) 2 to a locally-connected printer 12 . The following description of a typical printing process using the apparatus shown in FIG. 1 is based on the Microsoft® Windows® operating system.
The application program 4 issues graphical commands known as Graphical Device Interface (GDI) commands to the operating system. When sufficient GDI commands have been received by the operating system 6 to render a complete page, the data is converted into Device Driver Interface (DDI) commands that are sent to the device driver 8 . The device driver 8 converts these DDI commands into raw device commands (printer commands). The raw device commands (printer commands) are returned to the operating system 6 , which sends the data through the printer port 10 to the printer 12 for printing.
With this arrangement, all the software required for printing is located on the PC 2 . Before printing can take place, the system must be set up by installing the device driver 8 for the particular printer 12 attached to the PC 2 and configuring the printer port 10 to which the printer 12 is connected.
FIG. 2 of the accompanying drawings shows an arrangement for printing from a PC 2 on a network to a printer 12 connected to a server 14 on the network. The arrangement enables the PC 2 to print to any one of a number of printers connected to servers on the network. U.S. Pat. No. 5,699,495, entitled “Point-and-print in a distributed environment”, describes a system using this arrangement.
The arrangement of FIG. 2 differs in two key respects from that described with reference to FIG. 1 . Firstly, the device driver 8 is initially stored on the server 14 and is transferred over the network by the operating system 16 of the server 14 only when required by the client (i.e. the PC 2 ). Secondly, the raw device commands (printer commands) output by the device driver 8 are transferred over the network to the server 14 , which sends the commands through the printer port 10 to which the printer 12 is connected.
U.S. Pat. No. 6,201,611, entitled “Providing local printing on a thin client”, describes a system for printing to a locally-connected printer, but using resources located on a server to provide much of the processing. Application software running on the client issues graphical commands to the client operating system. Rather than calling a local device driver to produce raw print data, the commands are converted to a device-independent print file. The device-independent data are then sent over the network to the server, which converts the device-independent data to device-dependent data, using device drivers located on the server. The device-dependent data are then transferred from the server to the printer via the client. Local spooling of print data on the client is avoided by controlling the flow of device-dependent data from server to client. The printer may be connected to a client other than that to which the application is running. No method of ad-hoc printer configuration is described in U.S. Pat. No. 6,201,611. It is assumed that the server (or another server on the network) has been configured with the driver for the given printer.
US-A-2002/0018234, entitled “Printer driver system for remote printing”, describes a system in which print jobs are processed on a server, using a “universal” printer driver installed on the server, to produce a universal print file, which is a generic type of file that can be sent directly to the printer.
EP-A-1291786, GB-A-2365599, WO 01/042894, WO 02/041107 and JP-2003-114773 can each be considered to disclose a distributed peripheral device control method for controlling the interaction between an information device and a peripheral device in communication with the information device, comprising requesting the peripheral device to perform a specified task, sending device identification information identifying the peripheral device to a server in communication with the information device, the server having access to at least one peripheral device driver, selecting a device driver corresponding to the peripheral device in dependence upon on the device identification information, employing the server to perform, on behalf of the information device and using the selected device driver, peripheral device-dependent processing operations relating to the performance of the task to produce device-dependent data.
US 2002/0196478 discloses a system comprising a mobile computing device, a scanner or multi-function printer and a server. The scanner scans a paper document into an electronic document which is sent to the server. No device-dependent processing is required by the server, which acts as a temporary store before the electronic document is retrieved by the mobile computing device. The mobile computing device does not act as a gateway between the scanner and the server.
SUMMARY OF THE INVENTION
According to a first aspect of the present invention, there is provided a distributed peripheral device control method for controlling the interaction between an information device and a peripheral device in communication with the information device, comprising requesting the peripheral device to perform a specified task, sending device identification information identifying the peripheral device to a server in communication with the information device, the server having access to at least one peripheral device driver, selecting a device driver corresponding to the peripheral device in dependence upon the device identification information, establishing a virtual port at the server to form part of a communications link between the server and the information device and associating the virtual port with the selected device driver, employing the server to perform, on behalf of the information device and using the selected device driver, peripheral device-dependent processing operations relating to the performance of the task to produce device-dependent data, and sending the device-dependent data to the virtual port for onward transmission to the peripheral device via the information device to enable the peripheral device to perform the specified task.
The virtual port may be established and associated with the selected device driver so as to appear to an operating system of the server to be an interface to a physical port to which the peripheral device is attached but wherein any data sent to the virtual port are forwarded to the information device over the communications link rather than directly to the peripheral device.
The server may have access to a plurality of applications, and the method may further comprise the step of selecting an application in dependence upon the specified task to be performed, and the device-dependent processing operations may be performed in interaction with the selected device driver under the control of the selected application. The application need not perform any device-independent processing operations.
The server may have access to a plurality of applications for performing device-independent processing operations and the method may comprise the steps of selecting an application and employing the server to perform device-independent processing operations on behalf of the information device using the selected application. The application may be selected in dependence upon the specified task to be performed.
The method may further comprise the step of buffering the device-dependent data at the server to control the rate at which the data are sent to the information device. The buffering of the device-dependent data at the server may be controlled in dependence upon a control signal received from the peripheral device indicating the state of the peripheral device. The buffering of the device-dependent data at the server may be controlled in dependence upon the fullness of a memory used to buffer the device-dependent data at the information device.
The method may further comprise the step of buffering the device-dependent data at the information device to control the rate at which the data are sent to the peripheral device. The information device preferably begins to send device-dependent data to the peripheral device before all the device-dependent data necessary to perform the specified task are received from the server.
The method may further comprise the steps of compressing the device-dependent data at the server and decompressing the device-dependent data at the information device.
The method may further comprise the step of processing of the device-dependent data at the information device before sending it to the peripheral device. Therefore the device-dependent data sent to the peripheral device may not be identical to the device-dependent data received at the information device.
The peripheral device may comprise an output device.
The peripheral device may be a printer, in which case the specified task may be to perform a printing operation to print a selected document and the device-dependent data may be printer commands. The method may further comprise the step of sending the selected document from the information device to the server, or may further comprise the step of retrieving the selected document from a document server. The document server may be located in a separate device that is accessible by the server. The application may be selected by examining the document type, for example by examining the filename extension of the document.
The peripheral device may comprise an input device. In this case, the method may further comprise the steps of performing a specified task at the peripheral device to produce device-dependent data and sending the device-dependent data to the information device for onward transmission to the server. The device-dependent operations performed at the server may be for processing the device-dependent data to produce device-independent data for use by the selected application. The application may be selected in dependence upon on the specified task performed at the peripheral device. The rate at which device-dependent data are sent to the information device may be controlled in dependence upon a control signal received from the information device indicating the state of the information device. The rate at which device-dependent data are sent to the information device may be controlled in dependence upon the fullness of a memory used to buffer the device-dependent data at the information device. The method may further comprise the step of buffering the device-dependent data at the information device to control the rate at which the data are sent to the server. The method may further comprise the steps of compressing the device-dependent data at the information device and decompressing the device-dependent data at the server. The method may further comprise the step of processing of the device-dependent data at the information device before sending it to the server.
The input device may be a scanner, the specified task may be to perform a scanning operation to scan a document, and the device-dependent data may be scanner commands for controlling the scanner to perform the specified task.
According to a second aspect of the present invention, there is provided a distributed peripheral device control method for controlling the interaction between an information device and a peripheral device in communication with the information device, comprising requesting the peripheral device to perform a specified task to produce device-dependent data, sending device identification information identifying the peripheral device to a server in communication with the information device, the server having access to at least one peripheral device driver, selecting a device driver corresponding to the peripheral device in dependence upon the device identification information, establishing a virtual port at the server to form part of a communications link between the server and the information device and associating the virtual port with the selected device driver, sending the device-dependent data from the peripheral device to the server via the information device for receipt at the virtual port, employing the server to perform, on behalf of the information device and using the selected device driver, peripheral device-dependent processing operations on the device-dependent data received at the virtual port.
The virtual port may be established and associated with the selected device driver so as to appear to an operating system of the server to be an interface to a physical port to which the peripheral device is attached such that any data received at the virtual port appears to originate from the peripheral device.
The server may have access to a plurality of applications, the method may further comprise the step of selecting an application in dependence upon on the specified task performed at the peripheral device, and the device-dependent processing operations may be performed in interaction with the selected device driver under control of the selected application. The application need not perform device-independent processing operations.
The server may have access to a plurality of applications for performing device-independent processing operations, and may comprise the steps of selecting an application and employing the server to perform device-independent processing operations on behalf of the information device using the selected application.
The device-dependent operations performed at the server may be for processing the device-dependent data to produce device-independent data for use by the selected application.
The peripheral device may comprise an input device for producing the device-dependent data.
The input device may be a scanner and the specified task may be to perform a scanning operation to scan a document.
In the first or second aspects, the communication link may be a first communication link and the information device may be in communication with the peripheral device via a second communication link and the method may further comprise the step of creating a virtual port at the information device for forming part of the second communication link.
The communication link may be a first communication link and the information device may be in communication with the peripheral device via a second communication link and the method may further comprise the step of creating a virtual port at the information device for forming part of the first communication link.
The method may further comprise the step of obtaining the device identification information from the peripheral device by Plug and Play specifications. At least one of the plurality of peripheral device drivers may be located in the server. At least one of the plurality of peripheral device drivers may be located in a separate device driver server that is accessible by the server. The steps of the method may be controlled by the information device. The or each virtual port may be established under the control of the information device. The method may further comprise the step of performing peripheral device-independent processing operations at the information device.
The server may have access to a plurality of peripheral device drivers.
The first and second communication links may be wireless links, for example Bluetooth, IrDA or WiFi links. It may conform to the IEEE 802.11 standard.
On the other hand, the first and second communication links may be physical links, for example USB or serial cable links.
The first and second communication links may be telecommunication links, for example mobile telecommunications and/or Internet links.
The information device may be a resource-limited information device and may also be a portable information device, for example a Personal Digital Assistant or a mobile phone.
According to a third aspect of the present invention, there is provided a distributed peripheral device control system for controlling the interaction between an information device of the system and a peripheral device of the system in communication with the information device, comprising a portion which requests the peripheral device to perform a specified task, a portion which sends device identification information identifying the peripheral device to a server in communication with the information device, the server having access to at least one peripheral device driver, a portion which selects a device driver corresponding to the peripheral device in dependence upon the device identification information, a portion which establishes a virtual port at the server to form part of a communications link between the server and the information device and associates the selected device driver with the virtual port, a portion which employs the server to perform, on behalf of the information device and using the selected device driver, peripheral device-dependent processing operations relating to the performance of the task to produce device-dependent data, and a portion which sends the device-dependent data to the virtual port for onward transmission to the peripheral device via the information device to enable the peripheral device to perform the specified task.
According to a fourth aspect of the present invention, there is provided a distributed peripheral device control system for controlling the interaction between an information device of the system and a peripheral device of the system in communication with the information device, comprising a portion which requests the peripheral device to perform a specified task to produce device-dependent data, a portion which sends device identification information identifying the peripheral device to a server in communication with the information device, the server having access to at least one peripheral device driver, a portion which selects a device driver corresponding to the peripheral device in dependence upon the device identification information, a portion which establishes a virtual port at the server to form part of a communications link between the server and the information device and associates the selected device driver with the virtual port, a portion which sends the device-dependent data from the peripheral device to the server via the information device for receipt at the virtual port, and a portion which employs the server to perform, on behalf of the information device and using the selected device driver, peripheral device-dependent processing operations on the device-dependent data received at the virtual port.
According to a fifth aspect of the present invention, there is provided an operating program for controlling an information processing device or a distributed peripheral device control system to perform a method according to the first or second aspect of the present invention. The operating program may be carried on a carrier medium, for example a transmission medium or storage medium.
According to a sixth aspect of the present invention, there is provided an information processing device adapted for use in a method according to the first or second aspect of the present invention.
According to a seventh aspect of the present invention, there is provided a server adapted for use in a method according to the first or second aspect of the present invention.
BRIEF DESCRIPTION OF THE DRAWINGS
FIG. 1 , discussed hereinbefore, shows a typical arrangement for printing from a personal computer to a locally-connected printer;
FIG. 2 , also discussed hereinbefore, shows an arrangement for printing from a personal computer on a network to a printer connected to a server on the network;
FIG. 3 is a block diagram showing a distributed printing system according to a first embodiment of the present invention;
FIG. 4 is a flow diagram for use in explaining operation of the distributed printing system shown in FIG. 3 ; and
FIG. 5 is a block diagram showing a distributed scanning system according to a second embodiment of the present invention.
DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS
FIG. 3 is a block diagram showing a distributed printing system according to an embodiment of the present invention. The distributed printing system comprises a PDA 20 , a printer 28 and a server 30 . The PDA 20 is in communication with the printer 28 and the server 30 . The PDA 20 comprises a print service client 22 , a printer controller 24 and a port emulator 26 . The print service client 22 is in communication with the port emulator 26 and the printer controller 24 , the latter two of which are also in direct communication with each other. The server 30 comprises a document printing service 36 in communication with a document server 32 , a driver database 34 , a virtual printer port 38 , a printer driver 40 and an application program 42 . The latter three of these are in communication with an operating system 44 of the server 30 .
Operation of the distributed printing system shown in FIG. 3 will now be described with reference to the flow diagram in FIG. 4 .
The client software 22 on the PDA 20 establishes a connection to the printer 28 via a communication port (step S 1 ). In this embodiment the communication port is supplied by the port emulator 26 , which transmits and receives data over a wireless link, such as Bluetooth or IrDA. The client PDA 20 then establishes a connection to the document printing service 36 of the server 30 over the network (step S 2 ).
The client software 22 obtains information about the type (e.g. make and model) of the printer 28 (step S 3 ). For example, the Plug and Play External COM Device Specification presents a mechanism to provide automatic configuration of peripheral devices connected by serial communication ports, and there are similar specifications for parallel ports and other types of connection. The majority of printers designed for use with personal computers comply with Plug and Play specifications, which allow automatic identification of the type of a peripheral device.
The PDA 20 then sends information about the printer type of the printer 28 to the server 30 (step S 4 ). The server 30 uses the printer type information to look up the required printer driver in the driver database 34 (step S 5 ). The driver database 34 is assumed to supply a matching device driver for the printer 28 . The PDA 20 sends a print request to the server 30 for the requested document (step S 6 ).
The server 30 then creates the virtual printer port 38 . A virtual communication port is a software component that appears to the operating system 44 as the interface to a physical communication port. Any data written to or read from the port is sent to or received from some other process, rather than a device attached to a physical port. In this case, data written to the virtual printer port 38 is sent over the network to the PDA 20 , from where it is sent via the port emulator 26 to the printer 28 .
In the context of an operating system, a “printer” can generally be viewed as an association between a device driver, such as the printer driver 40 of FIG. 3 , and a communication port, such as the virtual printer port 38 of FIG. 3 . The exact process of configuring the printing system depends upon the server's operating system. In the case of the Windows® operating system, the printer is configured by specifying the port and device driver together with a print processor and port monitor. In this way, the system can be configured so that printing can take place using the previously-selected device driver and the virtual printer port.
To complete the set-up, the client PDA 20 creates the printer controller 24 , which controls the flow of data between the virtual printer port 38 and the port emulator 26 .
The server 30 retrieves the requested document from the document server 32 and the application associated with the document (step S 7 ). It is assumed that the system is able to associate the document with the correct application. For example, in the Windows® operating system the association is determined by the use of filename extensions. Alternatively, the user, using the client interface, may specify the application explicitly.
The application 42 is executed and instructed to print the document to the printer previously created by the document printing service 36 . The ways in which this can be done depend on the operating system and the application. Typically, the application 42 is executed and the document is printed by specifying the application, the document's file path and the printer name as parameters in a command-line. Under the Windows® operating system, a shell print command is often associated with a document type. In that case, it is sufficient to set the printer as the default printer for the system, and then execute the shell print command for the document.
When printing the document, the application issues Graphical Device Interface (GDI) commands to the operating system's graphics API (application programming interface). The operating system 44 converts calls to the graphics API into Device Driver Interface (DDI) calls, which the printing system sends to the device (printer) driver 40 to produce device-specific raw print commands (step S 8 ).
The printing system writes the device-specific printer commands to the virtual printer port 38 , which in turn sends the data across the network to the printer controller 24 on the PDA 20 (step S 9 ). The printer controller 20 transfers the print data received from the server 30 to the printer 28 via the port emulator 26 (step S 10 ).
In summary, the operation of a distributed printing system according to the present embodiment involves the following processes: (a) automatically identifying and loading the appropriate device-driver for the given printer; (b) transferring output from the server's printing system to the printer via the mobile device; (c) the use of software applications on the server to process documents for printing; (d) the automatic configuration of the server printing system, using the device driver obtained by (a), so that output from an application is further processed to produce printer-specific data, and that the data is transferred by process (b) to the printer; and (e) the control of the above processes from the mobile device.
The speed at which the virtual printer port 38 receives data is likely to outstrip that at which data can be sent to the printer 28 . To minimise the amount of memory required for buffering on the client PDA 20 , the printer controller 24 can remotely control the virtual printer port 38 so that the print data is buffered on the server-side 30 .
Although the driver database 34 is shown in the present embodiment as being located in the server 30 , it is also possible that the driver database 34 could be located in a centralised web service providing a large, regularly-updated database of printer drivers. Such a driver database 34 in the centralised web service could be accessed and downloaded by the document printing service 36 , enabling the system to support a wide variety of printers. Once downloaded, frequently-used drivers could be cached locally by the server 30 .
A distributed printing system embodying the present invention allows the use of printers on an ad-hoc basis, without the user having to configure the client or server for each printer. The system can work for any printer for which a driver is available for the server operating system. An infrared port, Bluetooth connection or wireless LAN connection would enable wireless connection from the PDA.
The applications, fonts, printer drivers and operating system components (graphics and printing subsystem) required to support them are located on the server, rather than the PDA. As well as minimising the burden on the PDA, this avoids such compromises as converting documents to generic formats.
The distributed printing system identifies the printer and loads the appropriate device driver, using a driver database. This avoids the compromise of using a “universal” printer driver. As mentioned above, to avoid burdening the server with every possible printer driver, the driver database could be in a separate system, possibly a web service, shared among multiple servers and possibly distributed.
Data sent from the server 30 to the PDA 20 is already rendered into printer commands. This has the following technical advantages. No processing of print data takes place on the PDA 20 and only the data that is sent to the printer passes through the PDA 20 . This reduces the processing that is required to be performed by the PDA 20 . Data may be streamed from the server 30 to the PDA 20 , thereby conserving storage on the PDA 20 and saving time by starting printing before all the data is received. On the other hand, pre-rendered print data may be less compact than the source document. However, the print data could be compressed on the server 30 and decompressed at the client PDA 20 .
The system can support two-way communication with the printer 28 . If, for example, the printer 28 runs out of paper, the printer controller 24 can receive such notification. In response to the problem, the client can notify the user and instruct the server 30 to suspend the transfer of print data from the virtual printer port 38 until the printer 28 is ready.
No modifications to the server's operating system are necessary. A distributed printing system embodying the present invention can make use of standard operating system features and components. Nor does the printer 28 have to be connected to a network or the Internet.
A distributed printing system embodying the present invention allows the user of a resource-limited mobile information device to print a document on a nearby printer, without having the document data, application software, a full graphical printing system, fonts and printer drivers installed on the mobile device. In this way the burden on the resource-limited information device is reduced.
The system uses software and data located on a remote server to provide most of the storage and processing required for printing documents. Application and system software running on the server are used to provide the system with document-rendering capabilities equivalent to a desktop PC. The role of the mobile device is limited to providing a user-interface, transfer of data between server and peripheral device, and controlling the process.
The system requires that the mobile information device (a PDA in the above-described embodiment, but which can be any sufficiently functional mobile information device) can communicate with a nearby printer. The communication between the PDA and printer can be via an emulated serial port connection over a wireless link, such as IrDA or Bluetooth as described above in relation to the above-described embodiment. Alternatively, the connection could be a real parallel or serial printer cable, USB, or LAN, or any other suitable link.
The PDA also requires a connection to the remote server over a network. This connection could be over a LAN, WAN, Internet or telephone network, or any other suitable communications link, for example a mobile telecommunications link.
The server requires access to the document that has been selected for printing. An embodiment of the present invention is not concerned with the method for browsing and selecting documents for printing, but assumes that a document has already been selected for printing and is accessible in some way to the server. In the above-described embodiment the document data was sent from the PDA 20 to the server 30 and stored on the server 30 . Alternatively, the document may be obtained from a document server on another machine, or accessed using a URL (or any other type of document reference used to locate the document), and downloaded to the server. Thus the document server may be a web server (where the document may be a web page or a file linked to from a web page), or it may be a peer-to-peer file sharing server, or any other type of server able to provide a document on request.
In the above-described embodiment, the system is implemented by a software service (called the printing service) running on the server, together with client software running on the PDA.
In the context of the above-described embodiment, the term “resource-limited” means having insufficient processing speed and/or resources, for example memory/storage resources, for conventional print processing tasks, with the likelihood that the performance of print processing tasks may often take too long or require more memory than is available on the device. An embodiment of the present invention is especially useful for such resource-limited devices since the burden on the device is reduced. However, it is to be understood that a system embodying the present invention may be useful even when the information device is not resource-limited as such, if there is some other reason why it is necessary or preferable for processing to take place off the device. For example, an embodiment of the invention may be used where the information device cannot control the peripheral device directly because a suitable driver isn't available at the device, or where downloading and installing a driver would be undesirable (perhaps for security reasons).
Although the description above is for an embodiment in which the peripheral device is a printer, the methods described are equally applicable to the use of other hardware. The requirement for hardware is that: (a) the device is connectable via a standard I/O port connection, including serial, parallel, USB, VGA and wireless connections such as Bluetooth or IrDA; and (b) a device driver is available for the server operating system together with applications capable of input and/or output with such a device. This includes embodiments in which the peripheral device is a graphical or textual output device other than a printer.
Further embodiments include those in which the peripheral device is a scanner, camera or other graphical input device. In the case of an input device, the output from the device is transferred from the peripheral device to drivers and applications on the server for processing and/or storage.
FIG. 5 is a block diagram showing a distributed scanning system according to a second embodiment of the present invention. The distributed scanning system comprises a PDA 20 ′, a scanner 28 ′ and a server 30 ′. The PDA 20 ′ is in communication with the scanner 28 ′ and the server 30 ′. The PDA 20 ′ comprises a scan service client 22 ′, a scanner controller 24 ′ and a port emulator 26 ′. The scan service client 22 ′ is in communication with the port emulator 26 ′ and the scanner controller 24 ′, the latter two of which are also in direct communication with each other. The server 30 ′ comprises a document scanning service 36 ′ in communication with a document storage portion 32 ′, a driver database 34 ′, a virtual scanner port 38 ′, a scanner driver 40 ′ and an application program 42 ′. The latter three of these are in communication with an operating system 44 ′ of the server 30 ′. Operation of the distributed scanning system shown in FIG. 5 is very similar to operation of the distributed printing system described above with reference to FIGS. 3 and 4 , and it will be readily apparent to the person skilled in the art how to modify the teaching of the distributed printing system (where the peripheral device is an output device) to enable a distributed scanning system (where the peripheral device is an input device). Similar or corresponding parts are labelled with the same reference numeral in FIGS. 3 and 5 but are distinguished by a prime symbol; for example the printer of FIG. 3 has a reference numeral 28 and the scanner of FIG. 5 has a reference numeral 28 ′.
Although in the above-described embodiment all data processing takes place on the server, it can also be applied so that further processing is done on the mobile device. This includes embodiments in which the application is a distributed application, consisting of a user interface running on the PDA and server programs that perform most of the data processing. Further examples of possible client-side processing include but are not limited to the following: creating a smaller set of data from the original document (such as selecting a single page from a word processor document for printing); putting data from a database or XML document into a displayable format, such as HTML; an application program that outputs data in a graphical format, such as a drawing program; and any case in which a document is generated by a program running on the client device.
Although it is described above as the server 30 / 30 ′ has access to a driver database 34 / 34 ′ having a plurality of device drivers, it will be appreciated that the server 30 / 30 ′ could have access only to a single, generic, device driver suitable for use with a number of peripheral devices 28 / 28 ′.
The operations performed by the mobile device and other parts of the distributed peripheral device control system to control the interaction between the mobile device and the peripheral device can be implemented in hardware or as an operating program running on the mobile device and on other parts of the distributed peripheral device control system. The operating program may be stored on a computer-readable medium or it could, for example, be embodied in a signal such as a downloadable data signal provided from an Internet website. The appended claims are to be interpreted as covering an operating program by itself, or as a record on a carrier, or as a signal, or in any other form. | A distributed peripheral device control method for controlling the interaction between an information device and a peripheral device in communication with the information device, comprising requesting the peripheral device to perform a specified task, sending device identification information identifying the peripheral device to a server, selecting a device driver corresponding to the peripheral device in dependence upon the device identification information, establishing a virtual port at the server to form part of a communications link between the server and the information device and associating the virtual port with the selected device driver, employing the server to perform, using the selected device driver, peripheral device-dependent processing operations relating to the performance of the task to produce device-dependent data, and sending the device-dependent data to the virtual port for onward transmission to the peripheral device via the information device to enable the peripheral device to perform the specified task. | 6 |
FEDERAL RESEARCH STATEMENT
The invention described herein was made by employees of the United States Government and may be manufactured and used by or for the Government of the United States of America for governmental purposes without the payment of any royalties thereon or therefor.
CROSS-REFERENCES TO RELATED APPLICATIONS
None.
FIELD OF INVENTION
The present invention relates to methods and apparatuses for stopping the flow of fluid and more particularly to an intelligent flow control valve.
TERMINOLOGY
As used herein, the term “anchor assembly” refers to one or more components used to hold and secure an intelligent flow control valve in position in a pipe.
As used herein, the term “expansion panel” refers to the pieces which make up the umbrella of an intelligent flow control valve.
As used herein, the term “scissor component” refers to a plurality of hinged brace components arranged symmetrically around a threaded component which enables the hinged brace components to be repositioned. For example, hinged brace components may be pushed away from the threaded component when the threaded component is turned one direction and pulled toward the threaded component when the threaded component is turned in the opposite direction.
As used herein, the term “throttle” means to increase or decrease the area of an umbrella to decrease or increase the pipe flow area, which controls flow.
As used herein, the term “umbrella” refers to an elongated component of a variable area control, component having a variable surface area which may be changed to increase or decrease the flow.
As used herein, the term “umbrella control lead screw” refers to a threaded component that is rotated to change the area of an umbrella to alter flow.
As used herein, the term “variable area control component” refers to the component of an intelligent flow control valve which is metered to increase or decrease the pipe flow area, changing the delta pressure across the device for different flow rates.
BACKGROUND OF THE INVENTION
A pipe plug is any type of physical barrier that effectively stops the flow of oil from an oil well or fluid from a pipe. Effective pipe-plugging methods and apparatuses are required in a variety of situations.
Many states regulate the plugging of abandoned well structures to confine oil, gas, and water in the strata in which they are found and prevent them from escaping into other strata and destroying wildlife and water and creating other environmental hazards. It is important in these situations to completely and permanently stop the flow.
When pipelines are damaged, it is necessary to quickly stop the uncontrolled flow, often without regard to the continuing viability of the pipeline. The Deepwater Horizon oil spill (commonly known as the “BP oil spill”) was the largest oil spill in the history of the petroleum industry. An estimated 53,000 barrels per day (8,400 m 3 /d) escaped from the well just before it was capped, amid an international outcry. Millions of television and Internet viewers watched black plumes of oils spilling into the ocean as the company attempted to inject “dead weight” in the form of heavy liquid and cement and other barriers into the top and bottom of the well.
Inserting a device into the escaping flow was difficult or impossible to control and the dead weight did not prevent blow out causing oil escape at other locations. In addition, due to extremely harsh environments (e.g., ocean floor), repairing these pipes is often very difficult.
Even more controversial than the escaping oil was the inability to monitor the flow of oil while repairs were being made.
Although the Deepwater Horizon oil spill was a well-publicized historic event, damage to pipelines occurs with some regularity and even predictability. Containing the BP spill was the predominant concern without regard to the future viability of the well. Many pipelines, however, must be repaired and placed back into use.
Dead weight plugging methods known in the art generally do not seal the pipes completely. In addition, these plugs cannot be removed once they are in place.
It is necessary to stop or meter the amount the flow during, and possibly after, the repair process. In addition, the plugging device must be capable of being opened or removed from the pipe once the repairs have been completed.
Various plugging methods and apparatuses are disclosed in the art (e.g., U.S. Pat. Nos. 2,646,845, 2,672,200, 2,710,065, 2,969,839, 3,070,163, 3,079,997, and 3,489,216). Invariably, these methods require placement of some type of material (e.g., heavy liquids, gravel, cementitious material, epoxy resin mixture, sealant, drilling mud) to form a solid barrier. These plugging methods and apparatuses are difficult or impossible to remove once the repair has been completed.
Typically, the pipe can be placed back into use only if a section of the pipe is cut out and the device removed. In addition, inserting a device that requires back-filling is complicated as constant pressure has to be applied while the back-filling material is drying.
The prior art also discloses attempts to create plugs which are mechanically adjustable to allow reuse of pipes after a repair. U.S. Pat. No. 6,241,424 (Bath '424) teaches a plug apparatus which includes a body shaft having an external surface and an internal cavity. A cup seal is mounted to the body shaft and engages an interior wall of the pipeline. The cup seal is roughly the size of the internal pipe. A cam is attached to the external surface of the body shaft and a slip assembly slides on the cam to engage a slip with the interior wall. A control mechanism controls the engagement and release of the slip from the interior wall. The plug taught by Bath '424 is not desirable because the fixed diameter of the cup seal does not allow for metered flow.
It is desirable to have a pipe plug which does not require back-filling.
It is desirable to have a pipe plug which may be easily removed from the pipe or which allows for flow through after repairs are made.
It is further desirable to have a pipe plug which allows for controlled and metered flow.
SUMMARY OF THE INVENTION
The present invention is an intelligent flow control valve comprised of an anchoring mechanism and a variable area control component. The variable area control component is comprised of a fixed frame; an internal longeron frame comprised of a plurality of tracks attached to the bottom of the fixed frame; a plurality of expansion panels; a plurality of alternating inner hinges and outer hinges which connect the expansion panels to form an umbrella; and a plurality of slide points along the inner hinges where the expansion panels slide along the tracks of*the internal longeron frame. To change the area of the expansion panels, an umbrella control lead screw is rotated in one direction to deploy the expansion panels and in the opposite direction to close the expansion panels.
BRIEF DESCRIPTION OF THE DRAWINGS
FIG. 1 illustrates a perspective view of an exemplary embodiment of an intelligent flow control valve with variable area control component closed.
FIG. 2 illustrates a perspective view of an exemplary embodiment of an intelligent flow control valve with variable area control component fully deployed.
FIG. 3 illustrates a perspective view of an exemplary embodiment of an intelligent flow control valve with optional pyrotechnic anchoring mechanisms.
FIG. 4 illustrates a bottom view of an exemplary embodiment of a variable area control component closed.
FIG. 5 illustrates a bottom view of an exemplary embodiment of a variable area control component fully deployed.
FIG. 6 illustrates a perspective view of an exemplary embodiment of a variable area control component closed.
FIG. 7 illustrates a perspective view of an exemplary embodiment of a variable area control component fully deployed.
FIG. 8 illustrates an exemplary embodiment of an intelligent flow control valve inside a pipe with variable area control component closed.
FIG. 9 illustrates an exemplary embodiment of an intelligent flow control valve inside a pipe with the frame secured against the pipe walls and variable area control component fully deployed.
FIG. 10 illustrates an exemplary embodiment of a variable area control component used as a variable area flow meter.
FIG. 11 illustrates an exemplary embodiment of an intelligent flow control valve for integrating with electronic flow calculation instrumentation.
DETAILED DESCRIPTION
For the purpose of promoting an understanding of the present invention, references are made in the text to exemplary embodiments of an intelligent flow control valve and variable area flow meter, only some of which are described herein. It should be understood that no limitations on the scope of the invention are intended by describing these exemplary embodiments. One of ordinary skill in the art will readily appreciate that alternate but functionally equivalent materials, components, and designs may be used. The inclusion of additional elements may be deemed readily apparent and obvious to one of ordinary skill in the art. Specific elements disclosed herein are not to be interpreted as limiting, but rather as a basis for the claims and as a representative basis for teaching one of ordinary skill in the art to employ the present invention.
It should be understood that the drawings are not necessarily to scale; instead, emphasis has been placed upon illustrating the principles of the invention. In addition, in the embodiments depicted herein, like reference numerals in the various drawings refer to identical or near identical structural elements.
Moreover, the terms “substantially” or “approximately” as used herein may be applied to modify any quantitative representation that could permissibly vary without resulting in a change in the basic function to which it is related.
FIG. 1 illustrates a perspective view of an exemplary embodiment of intelligent flow control valve 100 . In the embodiment shown, intelligent flow control valve 100 is comprised of lead screw 10 , umbrella control lead screw 15 , frame 20 , and variable area control component 80 .
In the embodiment shown, frame 20 is comprised of a plurality of vertical arms 40 and anchor assemblies 30 , 60 . Vertical arms 40 provide a rigid framework for anchor assemblies 30 , 60 and prevent rotation of anchor assemblies 30 , 60 while intelligent flow control valve 100 is secured inside a pipe.
In the embodiment shown, anchor assemblies 30 , 60 are scissor components comprised of moving collars 32 , 62 , rigid collars 34 , 64 , first set of braces 36 , 66 , and second set of braces 38 , 68 . Braces 36 , 66 are hinged at one end to moving collar 32 , 62 , respectively, and at the other end to vertical arms 40 . Braces 38 , 68 are hinged at one end to rigid collar 34 , 64 , respectively, and at the other end to vertical arms 40 . Braces 36 and braces 38 are secured to one end of said vertical arms 40 at a common pivot point and braces 66 and braces 68 are secured to the opposite end of vertical arms 40 at a common pivot point. The angle between braces 36 and braces 38 at the pivot point and between braces 66 and braces 68 at the pivot point increases or decreases as the distance between moving collar 32 and rigid collar 34 and moving collar 62 and rigid collar 64 changes.
Moving collars 32 , 62 and rigid collars 34 , 64 encircle lead screw 10 , which is threaded. Rigid collars 34 , 64 are fixed in position on lead screw 10 while moving collars 32 , 62 move when lead screw 10 is turned. In an exemplary embodiment, lead screw 10 has both left-handed and right-handed threads, allowing moving collars 32 , 62 to move toward rigid collars 34 , 64 when lead screw 10 is rotated in one direction and away from rigid collars 34 , 64 when lead screw 10 is rotated in the opposite direction. For example, moving collars 32 , 62 and the portions of lead screw 10 around moving collars 32 , 62 may have left-handed threads while rigid collars 34 , 64 and the portions of lead screw 10 surrounding rigid collars 34 , 64 may have right-handed threads.
When lead screw 10 is rotated so that moving collars 32 , 62 move toward rigid collars 34 , 64 , the angle between braces 36 and braces 38 and the angle between braces 66 and braces 68 decreases and vertical members 40 are pushed away from lead screw 10 toward to the pipe wall to anchor frame 20 and intelligent flow control valve 100 inside the pipe.
To pull vertical members 40 and frame 20 off of the pipe wall, that is, to remove intelligent flow control valve 100 from inside the pipe, lead screw 10 is rotated in the opposite direction, causing moving collars 32 , 62 to move away from rigid collars 34 , 64 . When moving collars 32 , 62 are moved away from rigid collars 34 , 64 , the angle between braces 36 and braces 38 and the angle between braces 66 and braces 68 increases and vertical members 40 move closer to lead screw 10 and away from the pipe wall.
In the embodiment shown, frame 20 includes four vertical arms 40 and each set of braces 36 , 38 , 66 , 68 has four braces. The vertical arms and braces are arranged around lead screw 10 so that intelligent flow control valve 100 is symmetrical, ensuring that the device self-centers when inserted into a pipe.
In the embodiment shown, variable area control component 80 is comprised of a fixed frame 70 , ring 75 , internal longeron frame 82 , and a plurality of expansion panels 84 . Fixed frame 70 and ring 75 add strength to variable area control component 80 , allowing variable area control component 80 to withstand high-pressure flow and eliminating the need for back-filling. Internal longeron frame 82 flairs out expansion panels 84 , creating a curved chamber to fit against the pipe wall and further strengthening variable area control component 80 .
In the embodiment shown, fixed frame 70 , ring 75 , and internal longeron frame 82 are comprised of heavy steel and internal longeron frame 82 is coated with polytetrafluoroethylene; however, in various other embodiments, may be comprised of another materials and/or coatings. In various other embodiments, ring 75 may be omitted.
In the embodiment shown, variable area control component 80 is cone-shaped and includes eight expansion panels 84 and internal longeron frame 82 has four tracks. Expansion panels 84 are hinged together, creating a plurality of inner hinges 92 and outer hinges 94 when variable area control component 80 is closed or partially deployed.
Material is removed from the outer edge of expansion panels 84 where outer hinges 94 are positioned, creating clearance cut-outs 96 . Without clearance cut-outs 96 , the edges of expansion panels 84 on outer hinges 92 would protrude past ring 75 , preventing ring 75 of variable area control component 80 from fitting against the pipe wall and/or preventing expansion panels 84 from opening and closing.
In various other embodiments, the number of expansion panels 84 and tracks of internal longeron frame 82 may vary. For example, variable area control component 80 may be comprised of sixteen expansion panels with an eight track internal longeron frame (i.e., factor of two). In various embodiments, the depth of variable area control component 80 , the placement of inner hinges 92 and outer hinges 94 may also vary to change the folded area and shape of variable area control component 80 .
To change the area of expansion panels 84 , umbrella control lead screw 15 , is rotated in one direction to deploy expansion panels 80 and in the opposite direction to close expansion panels 80 . When umbrella control lead screw 15 is rotated to deploy expansion panels 84 , fixed frame 70 , ring 75 , and internal longeron frame 82 slides downward along slide points 86 (see FIGS. 6 and 7 ), pushing out expansion panels 84 . When variable area control component 80 is fully deployed, expansion panels 84 rest against the tracks of internal longeron frame 82 .
To decrease the area of expansion panels 84 , that is, to partially or completely close variable area control component 80 , umbrella control lead screw 15 is rotated in the opposite direction, causing fixed frame 70 , ring 75 , and internal longeron frame 82 to slide away from expansion panels 84 along slide points 96 , retracting expansion panels 84 to increase flow. Increasing flow reduces the pressure across the variable area control component and decreasing flow increases the pressure across the variable area control component.
In the embodiment shown, the tracks of internal longeron frame 82 are positioned at a 45 degree angle to the spokes of fixed frame 70 to maximize the strength of internal longeron frame 82 , allowing variable area control component to withstand high pressure.
The dimensions of the components of variable area control component 80 and intelligent flow control valve 100 vary with the area of the pipe into which intelligent flow control valve 100 is to be inserted and whether it is used as a pipe plug, a flow meter, a flow controller, or combinations thereof. For example, for a pipe having a three inch diameter, intelligent flow control valve 100 has a length ranging from 12 to 18 inches with variable area control component 80 having a length of approximately 6 inches.
The design of variable area control component 80 allows the pipe open area to be changed, resulting in a variable area control and the ability to throttle, meter, and control gas or fluid flow. The pointed shape of variable area control component 80 allows for easy insertion into a flowing pipe with minimal resistance. The configuration of frame 20 and the cone shape of variable area control component 80 results in a strong device capable of with-standing high pressures and forces.
In addition, intelligent flow control valve 100 may further include instrumentation, allowing intelligent flow control valve 100 to be used as a differential head flow meter by adjusting the area of variable area control component 80 in response to different flowing conditions to enhance flow metering accuracy, control pressures losses, or control flows in a closed loop using feedback from the differential pressure across the device. In addition, using measured values from different flow areas enables estimation of fluid properties such as density and viscosity.
In various embodiments, intelligent flow control valve 100 may further include an optional robotic crawling mechanism for carrying intelligent flow control valve 100 deep into a pipe. In an exemplary embodiment, optional robotic crawling mechanism would include a motor for turning the lead screws.
In the embodiment shown, all components are designed for low drag in fluid.
FIG. 2 illustrates a perspective view of an exemplary embodiment of intelligent flow control valve 100 with variable area control component 80 in the deployed position. In the embodiment shown, the tops of expansion panels 84 are positioned just below ring 75 .
Also visible in FIG. 2 is pressure sensor port 95 for measuring the pressure of the flow across variable area control component 80 .
FIG. 3 illustrates a perspective view of an exemplary embodiment of intelligent flow control valve 100 with optional pyrotechnic anchoring mechanisms 50 attached to vertical arms 40 .
Intelligent flow control valve 100 is inserted into the pipe so that anchoring components 50 are pointed in the direction of pipe flow. In the embodiment shown, pyrotechnic anchoring components 50 are spear devices with pyrotechnic charged spikes 55 which are fired to securely anchor intelligent flow control valve 100 inside a pipe.
In an exemplary embodiment, pyrotechnic anchoring components 50 include an ignition wire, a pyrotechnic charge, and a spring-loaded latch. Firing pyrotechnic anchoring components 50 drives spikes 55 into the pipe wall, permanently securing intelligent flow control valve 100 inside the pipe. In various other embodiments, spikes 55 may be replaced with another component, such as a barb.
In the embodiment shown, spikes 55 contain tungsten carbide or depleted uranium, which may aid in metal fusion when spikes 55 are driven into the pipe wall. When intelligent flow control valve 100 is anchored inside the pipe, variable area control component 80 can be opened in the pipe to throttle the oil flow.
In the embodiment shown, intelligent flow control valve 100 includes eight pyrotechnic anchoring components 50 , two on each vertical arm 40 ; however, in various other embodiments, intelligent flow control valve 100 may include any number of pyrotechnic anchoring components. In various embodiments, one or more components scissor components, pyrotechnic charged spikes which are fired into the pipe wall, spring-loaded arms, external dead weight, permanent spikes pushed into the pipe wall via a lever or scissor motion, any other holding device, and combinations thereof may be used to brace and/or anchor intelligent flow control valve 100 in a pipe.
FIG. 4 illustrates a bottom view of an exemplary embodiment of variable area control component 80 closed. When variable area control component 80 is closed, ring 75 , internal longeron frame 82 , expansion panels 84 , inner hinges 92 , outer hinges 94 , and slide points 86 are visible from the bottom of variable area control component 80 .
FIG. 5 illustrates a bottom view of an exemplary embodiment of variable area control component 80 fully deployed. When variable area control component 80 is fully deployed, expansion panels 84 are pushed out at both inner hinges 92 and outer hinges 94 , forming a cone shape (see FIG. 7 ).
FIG. 6 illustrates a perspective view of an exemplary embodiment of variable area control component 80 closed showing inner hinges 92 , outer hinges 94 , and slide points 86 where expansion panels 84 are attached to internal longeron frame 82 .
FIG. 7 illustrates a perspective view of an exemplary embodiment of variable area control component 80 fully deployed. When umbrella control lead screw 15 (not shown) is rotated to deploy expansion panels 84 , fixed frame 70 , ring 75 , and internal longeron frame 82 slide downward along slide points 86 , pushing out expansion panels 84 .
FIG. 8 illustrates an exemplary embodiment of intelligent flow control valve 100 inside a pipe with variable area control component 80 in the closed position.
Intelligent flow control valve 100 is inserted into the open end of a flowing pipe with the variable area control component 80 inserted first. The shape of intelligent flow control valve 100 allows it be easily guided into the pipe. Frame 20 is expanded by rotating lead screw 10 , causing scissor action which pushes vertical arms 40 outward against the pipe walls, securing intelligent flow control valve inside the pipe.
Optional pyrotechnic anchoring components 50 (not shown) would then be fired to permanently anchor frame 20 and intelligent flow control valve 100 , if desired, to the pipe wall.
Once frame 20 is anchored, umbrella control lead screw 15 is rotated to activate variable area control component 80 . Rotating umbrella control lead screw 15 forces expansion of variable area control component 80 by sliding fixed frame 70 , ring 75 , and internal longeron frame 82 downward, pushing out inner folds 92 of expansion panels 84 . When variable area control component 80 is in its final position, expansion panels 84 rest against internal longeron frame 82 . In an exemplary embodiment, when variable area control component 80 is fully deployed, it blocks approximately 95% to 98% of the flow.
In various embodiments, additional components, such as rubber gaskets may be added around umbrella control lead screw 15 , ring 75 , and/or any other components where leaking may occur.
Intelligent flow control valve 100 substantially reduces the volume of fluid leaked while relief wells are implemented or the pipe is repaired. In addition, intelligent flow control valve 100 may be removed or umbrella control lead screw 15 may be turned in the reverse direction to increase flow at any time, allowing intelligent flow control valve 100 to remain in the pipe.
In various embodiments, intelligent flow control valve 100 may further include a pivot point between variable area control component 80 and frame 20 which allows intelligent flow control valve 100 to be inserted through curves in the pipe. In still other embodiments, variable area control component 80 may be decoupled from frame 20 before intelligent flow control valve 100 is inserted into the pipe. Variable area control component 80 is then attached to frame 20 when frame 20 has been secured in the desired location in the pipe.
FIG. 9 illustrates an exemplary embodiment of intelligent flow control valve 100 inside a pipe with frame 20 secured against the pipe walls and variable area control component 80 in the deployed position.
FIG. 10 illustrates an exemplary embodiment of variable area control component 80 used as a variable area flow meter. In the embodiment, variable area control component 80 a is closed, covering approximately 20% of the pipe area; variable area control component 80 b is partially deploying, covering approximately 50% of the pipe area; and variable area control component 80 c is fully deployed, covering approximately 95% of the pipe area.
In the embodiment shown, pressure sensors 105 and differential pressure sensors 108 are placed before and after the variable area control components 80 a , 80 b , 80 c.
FIG. 11 illustrates an exemplary embodiment of intelligent flow control valve 100 for integrating with electronic flow calculation instrumentation which allows intelligent flow control valve 100 to be used as a differential head flow meter by adjusting the area of variable area control component 80 in response to different flowing conditions to enhance flow metering accuracy, control pressures losses, or control flows in a closed loop using feedback from the differential pressure across the device. In addition, using measured values from different flow areas enables estimation of fluid properties such as density and viscosity.
Visible in the embodiment shown are variable area control component 80 and lead screw 10 . In various other embodiments, variable area control component 80 may be actuated using other system, including, but not limited to hydraulic, pneumatic, flex muscle, etc. | The present invention is an intelligent flow control valve which may be inserted into the flow coming out of a pipe and activated to provide a method to stop, measure, and meter flow coming from the open or possibly broken pipe. The intelligent flow control valve may be used to stop the flow while repairs are made. Once repairs have been made, the valve may be removed or used as a control valve to meter the amount of flow from inside the pipe. With the addition of instrumentation, the valve may also be used as a variable area flow meter and flow controller programmed based upon flowing conditions. With robotic additions, the valve may be configured to crawl into a desired pipe location, anchor itself, and activate flow control or metering remotely. | 4 |
FIELD OF THE INVENTION
[0001] The present invention relates to an antimicrobial cleansing composition and a method of cleaning or disinfecting a surface. The invention more particularly relates to an antimicrobial cleansing composition that provides antimicrobial efficacy in cleaning applications having relatively short contact times.
BACKGROUND OF THE INVENTION
[0002] Soap based cleansing composition provides antibacterial benefits largely associated with the removal of organisms from a surface through the cleansing/detergency action of such products. Such compositions commonly have biocidal action against many gram negative bacteria. The biocidal action of soap compositions against gram positive bacteria is considerably more limited within the contact times typical of product use, generally under 1 minute, and more commonly of the order of 30 seconds or less. Achieving biocidal action against gram positive bacteria is especially problematic in the case of high pH cleansing compositions, by which is meant that a 1 wt % solution thereof in water has a pH in a range of from 9 to 12 at 25° C.
[0003] Various routes to improving the biocidal activity of soap based cleansing compositions have been suggested.
[0004] US2008014247A (Lu et al., 2008) discloses a composition having metal containing material, stearic acid and a pharmaceutically acceptable carrier to treat conditions caused by gram-positive, gram-negative, fungal pathogens and/or antibiotic-resistant bacteria. It further provides a method for inhibiting biofilm proliferation. The metal containing material can be silver.
[0005] US3050467 B1 (Horowitz et al. 1962) discloses an antimicrobial cleansing composition consisting essentially of a mixture of a water-soluble soap and a silver salt of partially depolymerized alginic acid. The composition provides synergestic antimicrobial activity.
[0006] US2011224120 AA (Henkel) discloses liquid washing compositions having surfactant, silver and/or a silver compound and a non-neutralized fatty acid.
[0007] Our copending application EP14152965 (Unilever, 2014) discloses an alkaline cleansing composition of pH at least 9 having anionic surfactant including soap, silver and 0.01 to 10 wt % fatty acids providing a robust cleaning composition.
[0008] When silver compound is used in soap based cleaning compositions, silver at levels providing antimicrobial benefits as suggested in prior art is relatively unstable, undergoes discoloration and is aesthetically unpleasant.
[0009] Prior disclosures have not addressed the issue of providing an antimicrobial cleansing composition that affords an effective, fast, and broad spectrum control of bacteria and exhibits acceptable aesthetic properties.
[0010] Thus an object of the present invention is to provide an antimicrobial cleansing composition that provides biocidal activity in relatively short contact times of 1 minute to 10 seconds.
[0011] Another object of the present invention is to provide an antimicrobial cleansing composition which provides antimicrobial activity at very low concentration of silver compound.
[0012] A further object of the present invention is to provide an antimicrobial cleansing composition which has consumer-acceptable aesthetic properties.
[0013] A still further object of the present invention is to provide an antimicrobial composition that is highly efficacious against a broad spectrum of gram positive and gram negative bacteria.
[0014] We have determined that antibacterial activity in relatively short contact times against gram positive and gram negative microorganisms in a soap based cleansing composition having silver compound enhances considerably in presence of a further salt of carboxylic acid. It has been additionally found that the antibacterial activity is enhanced even at very low concentrations of silver compound.
[0015] Given the relatively high cost of silver, such low levels of silver compound provides for significant cost benefits, compared to the higher levels of silver compounds required to provide significant biocidal effect within the contact times of interest. Additionally, the low levels of silver compound are desirable from both a sensory and process vantage.
SUMMARY OF THE INVENTION
[0016] According to a first aspect of the present invention disclosed is an antimicrobial cleansing composition comprising:
[0017] (i) 1 to 85 wt % of a fatty acid soap;
[0018] (ii) 0.1 to 100 ppm of a silver(I) compound; and further comprises,
[0019] (iii) 0.1 to 10 wt % of a salt of carboxylic acid.
[0020] According to a second aspect of the present invention disclosed is a method of cleaning or disinfecting a surface comprising the steps of applying a composition of the first aspect on to said surface and at least partially removing the composition from the surface.
[0021] The invention will now be explained in detail.
DETAILED DESCRIPTION OF THE INVENTION
[0022] Except in the operating and comparative examples, or where otherwise explicitly indicated, all numbers in this description indicating amounts, parts, percentages, ratios, and proportions of material, physical properties of material, and conditions of reaction are to be understood as modified by the word “about”. All parts, percentages, ratios, and proportions of material referred to in this description are by weight unless otherwise indicated.
[0023] The term “comprising” is meant not to be limiting to any subsequently stated elements but rather to encompass non-specified elements of major or minor functional importance. In other words, the listed steps, elements or options need not be exhaustive. Whenever the words “including” or “having” are used, these terms are meant to be equivalent to “comprising” as defined above. Where the compositions of the subject invention are described as “including” or “comprising” specific components or materials, narrower embodiments where the compositions can “consist essentially of” or “consist of” the recited components or materials are also contemplated.
[0024] It should also be noted that in specifying any range of concentration or amount, any particular upper concentration or amount can be associated with any particular lower concentration or amount.
[0025] The compositions of the present invention are preferred for medical or non-medical use, and more particularly preferred for cosmetic use in removing plaque on the surfaces of the oral cavity.
[0026] Antimicrobial Cleansing Composition
[0027] Disclosed antimicrobial cleansing composition includes a fatty acid soap, a silver (I) compound and further includes a salt of carboxylic acid.
[0028] Fatty Acid Soap:
[0029] Disclosed antimicrobial cleansing composition includes a fatty acid soap. The term “fatty acid soap” or, more simply, “soap” is used here in its popular sense, i.e., salts of aliphatic alkane- or alkene monocarboxylic fatty acids preferably having 6 to 22 carbon atoms, and more preferably 8 to 18 carbon atoms.
[0030] Usually a blend of fatty acids is used to get a blend of fatty acid soaps. The term “soap” refers to sodium, potassium, magnesium, mono-, di- and tri-ethanol ammonium cation or combinations thereof. In general, sodium soaps are preferred in the compositions of this invention, but up to 15% or even more of the soap content may be some other soap forms such as potassium, magnesium or triethanolamine soaps.
[0031] Preferably the fatty acid blend is made from fatty acids that may be different fatty acids, typically fatty acids containing fatty acid moieties with chain lengths of from C 8 to C 22 . The fatty acid blend may also contain relatively pure amounts of one or more fatty acids. Suitable fatty acids include, but are not limited to, butyric, caproic, caprylic, capric, lauric, myristic, myristelaidic, pentadecanoic, palmitic, palmitoleic, margaric, heptadecenoic, stearic, oleic, linoleic, linolenic, arachidic, gadoleic, behenic and lignoceric acids and their isomers.
[0032] The fatty acid blend preferably includes relatively high amounts (e.g., at least 3%, preferably at least 10%) of capric and lauric acids. Further preferably the fatty acid blend includes low levels of myristic acid, (e.g. preferably less than 4% by wt.) which generally provides good lathering property.
[0033] In preferred embodiments, the fatty acid blend has proportion of capric acid to lauric acid ranging from 0.5 to 1 to 1.5 to 1.
[0034] Soaps having the fatty acid distribution of coconut oil and palm kernel oil may provide the lower end of the broad molecular weight range. Those soaps having the fatty acid distribution of peanut or rapeseed oil, or their hydrogenated derivatives, may provide the upper end of the broad molecular weight range.
[0035] It is preferred to use soaps having the fatty acid distribution of coconut oil or tallow, or mixtures thereof, since these are among the more readily available triglyceride fats. The proportion of fatty acids having at least 12 carbon atoms in coconut oil soap is about 85%. This proportion will be greater when mixtures of coconut oil and fats such as tallow, palm oil, or non-tropical nut oils or fats are used, wherein the principle chain lengths are C16 and higher. Preferred soap for use in the compositions of this invention has at least about 85 percent fatty acids having about 12 to 18 carbon atoms. The preferred soaps for use in the present invention should include at least about 30 percent saturated soaps, i.e., soaps derived from saturated fatty acids, preferably at least about 40 percent, more preferably about 50 percent, saturated soaps by weight of the fatty acid soap. Soaps can be classified into three broad categories which differ in the chain length of the hydrocarbon chain, i.e., the chain length of the fatty acid, and whether the fatty acid is saturated or unsaturated. For purposes of the present invention these classifications are: “Laurics” soaps which encompass soaps which are derived predominantly from C12 to C14 saturated fatty acid, i.e. lauric and myristic acid, but can contain minor amounts of soaps derived from shorter chain fatty acids, e.g., C10. Laurics soaps are generally derived in practice from the hydrolysis of nut oils such as coconut oil and palm kernel oil.
[0036] “Stearics” soaps which encompass soaps which are derived predominantly from C16 to C18 saturated fatty acid, i.e. palmitic and stearic acid but can contain minor level of saturated soaps derived from longer chain fatty acids, e.g., C20. Stearic soaps are generally derived in practice from triglyceride oils such as tallow, palm oil and palm stearin.
[0037] Oleic soaps which encompass soaps derived from unsaturated fatty acids including predominantly oleic acid, linoleic acid, myristoleic acid and palmitoleic acid as well as minor amounts of longer and shorter chain unsaturated and polyunsaturated fatty acids. Oleics soaps are generally derived in practice from the hydrolysis of various triglyceride oils and fats such as tallow, palm oil, sunflower seed oil and soybean oil. Coconut oil employed for the soap may be substituted in whole or in part by other “high-laurics” or “laurics rich” oils, that is, oils or fats wherein at least 45 percent of the total fatty acids are composed of lauric acid, myristic acid and mixtures thereof. These oils are generally exemplified by the tropical nut oils of the coconut oil class. For instance, they include: palm kernel oil, babassu oil, ouricuri oil, tucum oil, cohune nut oil, murumuru oil, jaboty kernel oil, khakan kernel oil, dika nut oil, and ucuhuba butter.
[0038] Disclosed composition includes 1 to 85wt % of a fatty acid soap. Preferably the fatty acid soap is present in an amount not more than 80wt %, more preferably not more than 75wt %, still more preferably not more than 65wt %, further preferably not more than 55wt % and still further preferably not more than 45wt % and most preferably not more than 35wt % but preferably not less than 5wt %, more preferably not less than 10wt %, still more preferably not less than 15wt % and further preferably not less than 20wt % and most preferably not less than 25wt %.
[0039] Silver(I) Compound:
[0040] Disclosed antimicrobial cleansing composition includes 0.1 to 100 ppm silver (I) compound. Preferably the silver compounds are water-soluble having a silver ion solubility at least 1.0×10 −4 mol/L (in water at 25° C.). Silver ion solubility, as referred to herein, is a value derived from a solubility product (Ksp) in water at 25° C., a well known parameter that is reported in numerous sources. More particularly, silver ion solubility [Ag+], a value given in mol/L may be calculated using the formula:
[0000] [Ag+]=( Ksp x ) (1/(x+1))
[0000] wherein Ksp is the solubility product of the compound of interest in water at 25° C., and x represents the number of moles of silver ion per mole of compound. It has been found that Silver(I) compounds having a silver ion solubility of at least 1×10 −4 mol/L in are suitable for use herein. Silver ion solubility values for a variety of silver compounds are given in Table 1:
[0000]
TABLE 1
Silver Ion
Ksp
Solubility
(mol/L in water
[Ag+] (mol/L in
Silver Compound
X
at 25° C.)
water at 25° C.).
silver nitrate
1
51.6
7.2
Silver acetate
1
2.0 × 10 −3
4.5 × 10 −2
Silver sulfate
2
1.4 × 10 −5
3.0 × 10 −2
Silver benzoate
1
2.5 × 10 −5
5.0 × 10 −3
Silver salicylate
1
1.5 × 10 −5
3.9 × 10 −3
Silver carbonate
2
8.5 × 10 −12
2.6 × 10 −4
Silver citrate
3
2.5 × 10 −16
1.7 × 10 −4
Silver oxide
1
2.1 × 10 −8
1.4 × 10 −4
Silver phosphate
3
8.9 × 10 −17
1.3 × 10 −4
Silver chloride
1
1.8 × 10 −10
1.3 × 10 −5
Silver bromide
1
5.3 × 10 −13
7.3 × 10 −7
Silver iodide
1
8.3 × 10 −17
9.1 × 10 −9
Silver sulfide
2
8.0 × 10 −51
2.5 × 10 −17
[0041] A preferred silver(I) compound is selected from silver oxide, silver nitrate, silver acetate, silver sulfate, silver benzoate, silver salicylate, silver carbonate, silver citrate and silver phosphate, more preferably the silver compound is silver oxide, silver sulfate or silver citrate and still further preferred silver(I) compound is silver oxide or silver sulphate.
[0042] Preferably in the disclosed antimicrobial cleansing composition silver (I) compound is present at levels not less than 0.4 ppm, still preferably not less than 0.5 ppm and further preferably not less than 1 ppm and it is preferred that the silver (I) compound in the composition is present at levels not more than 80 ppm, more preferably not more than 50 ppm, further preferably not more than 20 ppm and still further preferably not more than 10 ppm and most preferably not more than 5 ppm. It is highly preferred that the silver (I) compound in the antimicrobial cleansing composition is present at 0.5 to 5 ppm.
[0043] Salt of Carboxylic Acid:
[0044] Disclosed antimicrobial cleansing composition further includes 0.1 to 10% by weight of a salt of carboxylic acid.
[0045] The composition preferably has not less than 0.5% by weight, more preferably not less than 0.75% by weight and still more preferably not less than 1% by weight of the salt of carboxylic acid. The composition preferably has not more than 5% by weight, more preferably not more than 3% by weight and still more preferably not more than 1.25% by weight of the salt of carboxylic acid.
[0046] Disclosed salt of carboxylic acid is preferably a salt of mono, di or tri carboxylic acid. When the salt of carboxylic acid is a salt of mono-carboxylic acid, the mono-carboxylic acid preferably has 1 to 6 carbon atoms more preferably the mono-carboxylic acid is selected from lactate or benzoate. More preferably the salt of carboxylic acid is a salt of di or tri carboxylic acid. When the salt of carboxylic acid is a salt of a di-carboxylic acid it preferably has 1 to 12 carbon atoms and when the salt of carboxylic acid is a salt of tri-carboxylic acid it preferably has 1 to 18 carbon atoms. It is further preferred that the salt of di or tri carboxylic acid is chosen from an oxalic, fumaric, phthalic, maleic, malic, malonicor citric acid. The di or tricarboxylic acid is most preferably a malic, malonic, or citric acid. It is possible that the part of the di or tri-carboxylic acid that is added to prepare the composition of the invention is present as salt of the di or tricarboxylic acid depending on the pH at which the composition is formulated. In such cases, the salt is preferably alkali metal or alkaline earth metal salts, more preferably alkali metal salts of which sodium salt is most preferred. Structure of salts of some of the carboxylic acids is given below:
[0000]
[0047] Salt of carboxylic acid in the disclosed composition is preferably selected from oxalate, lactate, fumarate, phthalate, benzoate, maleate, malate, malonate or citrate more preferably the salt of carboxylic acid is selected from a lactate, malate, malonate, or citrate.
[0048] It is observed that inclusion of a salt of di or tri carboxylic acid in the composition of the invention provides for the desired antimicrobial efficacy while the efficacy of mono carboxylic acids is comparatively less.
[0049] The non-metal salts of carboxylic acid are also preferably be used in the present invention. The most preferred non-metal salt of carboxylic acid is ammonium benzoate.
[0050] Preferably, the salt of carboxylic acid used in the invention may be a mixture of two or more salts of carboxylic acid. The mixture may also preferably between metal and non-metal salt of carboxylic acid.
[0051] Optional Ingredients:
[0052] Surfactant
[0053] If desired, the formulations may optionally include a detersive surfactant in addition to the fatty acid soap. Such detersive surfactants include, for example, anionic, zwitterionic and/or nonionic surfactants.
[0054] Examples of anionic surfactants suitable for use herein include, but are not limited to, ammonium lauryl sulfate, ammonium laureth sulfate, triethylamine lauryl sulfate, triethylamine laureth sulfate, triethanolamine lauryl sulfate, triethanolamine laureth sulfate, monoethanolamine lauryl sulfate, monoethanolamine laureth sulfate, diethanolamine lauryl sulfate, diethanolamine laureth sulfate, lauric monoglyceride sodium sulfate, sodium lauryl sulfate, sodium laureth sulfate, potassium laureth sulfate, sodium lauryl sarcosinate, sodium lauroyl sarcosinate, potassium lauryl sulfate, sodium trideceth sulfate, sodium methyl lauroyl taurate, sodium lauroyl isethionate, sodium laureth sulfosuccinate, sodium lauroyl sulfosuccinate, sodium tridecyl benzene sulfonate, sodium dodecyl benzene sulfonate, sodium lauryl amphoacetate and mixtures thereof.
[0055] The anionic surfactant may be, for example, an aliphatic sulfonate, such as a primary C 8 -C 22 alkane sulfonate, primary C 8 -C 22 alkane disulfonate, C 8 -C 22 alkene sulfonate, C 8 -C 22 hydroxyalkane sulfonate or alkyl glyceryl ether sulfonate.
[0056] Zwitterionic surfactants suitable for use herein include, but are not limited to derivatives of aliphatic quaternary ammonium, phosphonium, and sulfonium compounds, in which the aliphatic radicals can be straight or branched chain, and wherein one of the aliphatic substituents contains from about 8 to about 18 carbon atoms and one substituent contains an anionic group, e.g., carboxy, sulfonate, sulfate, phosphate, or phosphonate. Illustrative zwitterionic surfactants are coco dimethyl carboxymethyl betaine, cocoamidopropyl betaine, cocobetaine, oleyl betaine, cetyl dimethyl carboxymethyl betaine, lauryl bis-(2-hydroxyethyl) carboxymethyl betaine, stearyl bis-(2-hydroxypropyl) carboxymethyl betaine, oleyl dimethyl gamma-carboxypropyl betaine, lauryl bis-(2-hydroxypropyl)alpha-carboxyethyl betaine, and mixtures thereof. The sulfobetaines may include stearyl dimethyl sulfopropyl betaine, lauryl dimethyl sulfoethyl betaine, lauryl bis-(2-hydroxyethyl) sulfopropyl betaine and mixtures thereof.
[0057] Nonionic surfactants which may be used include the reaction products of compounds having a hydrophobic group and a reactive hydrogen atom. Exemplative are alcohols, acids, amides or alkyl phenols reacted with alkylene oxides, especially ethylene oxide either alone or with propylene oxide. Specific nonionics are C 6 -C 22 alkyl phenols-ethylene oxide condensates, the condensation products of C 8 -C 18 aliphatic primary or secondary linear or branched alcohols with ethylene oxide, and products made by condensation of ethylene oxide with the reaction products of propylene oxide and ethylenediamine. Other nonionics include long chain tertiary amine oxides, long chain tertiary phosphine oxides and dialkyl sulphoxides. Also useful are the alkyl polysaccharides.
[0058] Preferred surfactant is an anionic surfactant or amphoteric surfactant. Anionic surfactant is preferably an alkyl ether sulphate.
[0059] Form of the Composition
[0060] The composition preferably may be in the form of a solid, soft solid, gel, emulsion, or liquid.
[0061] Preferably a 1 wt % solution of the composition in water has a pH in a range of from 9 to 12 at 25° C.
[0062] When the disclosed composition is in the solid form, the composition is preferably a bar. The soap bar may be prepared by the milled and plodded route or may be prepared using the melt cast route. Of the two routes the milled and plodded route is more preferred for preparing a soap bar of the present invention.
[0063] Personal wash compositions are available in various forms such as soap bars, transparent soap bars including cast-bars, liquid soaps including liquid hand wash compositions, creams and gel based products. Commercial soap compositions have one or more “soaps”, which has the meaning as normally understood in the art; salts of mono carboxylic fatty acids. The counterions of the salts are generally sodium, potassium, ammonium or alkanolammonium ions, but other suitable ions known in the art may also be used. Compositions based on soaps, i.e. soap bars generally contain anywhere from 15 to 80% by weight alkali metal salt of fatty acids, depending on whether the soap is in solid or liquid form, which accounts for the total fatty matter (TFM), the remainder being water (about 10-20%) and other ingredients such as metal ion chelators, color, perfume, preservatives etc. Structurants and fillers are also frequently added to such compositions in small amount to replace some of the soap, while retaining the desired properties of the product. Soaps having TFM content of about 70 are called “toilet soaps”, whereas those having TFM of about 40 are called “bathing bars”. In a soap bar, the composition preferably comprises 0.1 to 5% hydrotrope.
[0064] Method of Cleaning and Disinfecting a Surface
[0065] According to a second aspect of the present invention there is provided a method of cleaning or disinfecting a surface comprising the steps of applying a composition of the first aspect onto said surface and at least partially removing the composition from the surface.
[0066] Preferably the method of at least partially removing the composition is carried out less than 5 minutes after the step of applying the composition on the substrate.
[0067] The composition is preferably diluted with water in a weight ratio of 1: 10 to 1: 40, preferably in a ratio of 1:20 to 1:30, before or during the step of applying the composition on the surface.
[0068] The method preferably comprises a step of rinsing the surface with a suitable solvent preferably water or the surface may be wiped with a suitable wipe.
[0069] The inventors have determined that the composition of the invention provides an antimicrobial action where the contact time of the antimicrobial actives with the surface is low, i.e. of the order of less than 5 minutes, preferably less than 2 minutes, further more preferably less than a minute and in many cases less than 15 seconds.
[0070] The invention will now be demonstrated by way of the following non-limiting examples.
EXAMPLES
[0071] The following protocol was used to evaluate biocidal activity.
[0072] In-vitro Time-kill Protocol
[0073] Fatty acid soap composition: A composition as shown on Table 2 was prepared.
[0074] Stock of a salt of carboxylic acid: A 20% stock of a salt of carboxylic acid was separately prepared. 20% stock solutions of each of sodium citrate, sodium malonate, sodium lactate and sodium benzoate were prepared.
[0075] Stock of silver compound: A 0.01 mg/mL stock of silver compound was prepared. The stock was thoroughly vortexed before adding it into the fatty acid soap composition.
[0000]
TABLE 2
Fatty acid soap composition
Wt %
Potassium salt of fatty acid (lauric acid,
14.6
myristic acid, palmitic acid)
Butylated Hydroxytoluene (BHT)
0.05
Ethylenediaminetetraacetic acid
0.13
(EDTA)
Cellulose Ether
0.5
(Methocel ™ 40-100
from Dow Chemical)
Glycerin
0.5
Potassium Hydroxide
3.5
Ethyl glycol distearate (EGDS)
1
Potassium Chloride
3
Demineraised water and other minors
to make it to 100
[0076] Preparation of Comparative and Preferred Composition
[0077] Comparative composition 1 (Comp 1): 5 grams of soap composition provided on Table 2 was diluted in 4 mL of sterile distilled water at room temperature.
[0078] Comparative composition 2 (Comp 2): To 5 grams of soap composition provided on Table 2, 0.5 mL of 20% stock solution of sodium citrate was added and mixed thoroughly. The resultant mixture was diluted with 3.5 mL of sterile distilled water at room temperature.
[0079] Comparative composition 3 (Comp 3): To 5 grams of soap composition provided on Table 2, 1 mL of 0.01 mg/mL of stock solution of Ag 2 O was added and mixed thoroughly. The resultant mixture was diluted with 3 mL of sterile distilled water at room temperature.
[0080] Comparative composition 4 (Comp 4): To 5 grams of soap composition provided on Table 2, 1 mL of 0.01 mg/mL of stock solution of Ag 2 SO 4 was added and mixed thoroughly. The resultant mixture was diluted with 3 mL of sterile distilled water at room temperature.
Preferred Example 1 (Ex 1)
[0081] To 5 grams of soap composition provided on Table 2, 1 mL of 0.01 mg/mL of stock solution of Ag 2 O and 0.5 mL of 20% stock solution of sodium citrate were added and mixed thoroughly and then diluted with 2.5 mL of sterile distilled water at room temperature.
Preferred Example 2 (Ex 2)
[0082] To 5 grams of soap composition provided on Table 2, 1 mL of 0.01 mg/mL of stock solution of Ag 2 SO 4 and 0.5 mL of 20% stock solution of sodium citrate were added and mixed thoroughly and then diluted with 3 mL of sterile distilled water at room temperature.
Preferred Example 3 (Ex 3)
[0083] To 5 grams of soap composition provided on Table 2, 1 mL of 0.01 mg/mL of stock solution of Ag 2 O and 0.5 mL of 20% stock solution of sodium malonate were added and mixed thoroughly and then diluted with 3 mL of sterile distilled water at room temperature.
Preferred Example 4 (Ex 4)
[0084] To 5 grams of soap composition provided on Table 2, 1 mL of 0.01 mg/mL of stock solution of Ag 2 O and 0.5 mL of 20% stock solution of sodium lactate were added and mixed thoroughly and then diluted with 3 mL of sterile distilled water at room temperature.
Preferred Example 5 (Ex 5)
[0085] To 5 grams of soap composition provided on Table 2, 1 mL of 0.01 mg/mL of stock solution of Ag 2 SO 4 and 0.5 mL of 20% stock solution of sodium benzoate were added and mixed thoroughly and then diluted with 3 mL of sterile distilled water at room temperature. The comparative composition and the preferred composition are shown in Table 3.
[0086] Preparation of the Bacterial Culture
[0087] Escherichia.coli ATCC 10536 was used in the study to represent gram negative bacteria and Staphylococcus aureus ATCC 6538 was used to represent gram positive bacteria. The bacteria were grown overnight on Trypticase soya agar (TSA) plate. The bacterial cell density was then adjusted at 620 nm to a pre-calibrated optical density to get the final count of 10 8 cfu/ml in saline (0.8% NaCl) by using a spectrophotometer.
[0088] Assay Protocol
[0089] 9 mL of the comparative composition 1 (Comp 1) was taken in a sample container to which 1 mL of bacterial culture was added just before performing the assay and mixed well to obtain a mixture. The mixture was kept for a specific contact time of either 10 seconds, 30 seconds, 1 minute or 5 minutes.
[0090] At the end of the contact time the antibacterial activity of the comparative composition 1 (Comp1) was neutralized immediately, by addition of 1 mL of the above mixture to 9 mL of D/E broth (39 gpl-Difco). The neutralized samples were then serially diluted upto 5 dilution in D/E broth and plated on TSA (40 gpl-Difco) in duplicates.
[0091] The above mentioned assay protocol was similarly followed for all other comparative and preferred compositions.
[0092] For the assay, the control used was a mixture prepared by addition of 1 mL of bacterial culture to 9 mL of saline; the mixture was then serially diluted and plated on TSA. After solidification of the TSA plates, the plates were incubated at 37° C. for 48 hours. The colonies on the plates were counted. The log reduction was calculated by comparing with the control.
[0000]
TABLE 3
Biocidal activity
Log 10 Reduction against S. aureus ATCC 6538
Contact time
10
30
Example
Composition
seconds
seconds
Comp 1
Fatty acid soap
0.4
0.6
Comp 2
Fatty acid soap + 1 wt % sodium citrate
0.6
0.8
Comp 3
Fatty acid soap + 1 ppm Ag 2 O
1.1
2.8
Ex 1
Fatty acid soap + 1 ppm Ag 2 O +
2.3
>5
1 wt % sodium citrate
Comp 4
Fatty acid soap + 1 ppm Ag 2 SO 4
1.0
3.0
Ex 2
Fatty acid soap + 1 ppm Ag 2 SO 4 +
1.7
>5
1 wt % sodium citrate
[0093] The data in Table 3 demonstrates that, at the indicated contact times, the preferred compositions Ex1 and Ex 2 had greater bactericidal efficacy against S. aureus ATCC 6538 than the comparative composition (Comp1, Comp 2, Comp 3 and Comp 4).
[0000]
TABLE 4
Biocidal activity
Log 10 Reduction against E. coli ATCC 10536
Contact time
Example
Composition
10 seconds
Comp 1
Fatty acid soap
2.6
Comp 2
Fatty acid soap + 1 wt % sodium citrate
3.5
Comp 3
Fatty acid soap + 1 ppm Ag 2 O
3.3
Ex 1
Fatty acid soap + 1 ppm Ag 2 O + 1 wt %
>5
sodium citrate
Ex 3
Fatty acid soap + 1 ppm Ag 2 O + 1 wt %
>5
sodium malonate
Ex 4
Fatty acid soap + 1 ppm Ag 2 O + 1 wt %
>5
sodium lactate
Ex 5
Fatty acid soap + 1 ppm Ag 2 SO 4 + 1 wt %
>5
sodium benzoate
[0094] The data in Table 4 demonstrates that, at the indicated contact times, that the preferred compositions Ex 1, 3, 4 and 5 had greater bactericidal efficacy against E. coli ATCC 10536 than the comparative composition (Comp1, Comp 2, Comp 3). The data on Table 4 also indicates that improved bacterial efficacy against E. coli ATCC 10536 is shown by various salts of carboxylic acid for example malonate, lactate, benzoate and citrate in cleansing compositions having fatty acid soap and silver (I) compound.
[0095] In another set of experiments non-metal salts of carboxylic acid and a mixture of a metal and a non-metal salt of carboxylic acid has been used:
[0096] The fatty acid soap composition for these sets of experiments has been given below in Table 5.
[0000]
TABLE 5
Fatty acid soap composition
Wt %
Lauric Acid
5.8
Myristic Acid
6.7
Palmitic Acid
2.1
Butylated Hydroxytoluene (BHT)
0.05
Ethylenediaminetetraacetic acid (EDTA)
0.13
Methocel 40-100 (The Dow Chemical
0.5
Company)
Glycerin
0.5
Potassium Hydroxide
3.5
SLES, 1EO (70%)
3
Cocamidopropyl betaine (CAPB)
2.5
Ethyl glycol distearate (EGDS)
1
Potassium Chloride
3
Demineraised water
To 100
[0097] Preparation of Comparative and Preferred Composition
[0098] Comparative composition 5 (Comp 5): 5 grams of soap composition of Table 5 with 1 ppm of Ag 2 O (as silver DTPA complex) was diluted with 5 mL of sterile distilled water at room temperature.
Preferred Example 6 (Ex 6)
[0099] 5 grams of soap composition of Table 5 with 1 ppm of Ag 2 O (as silver DTPA complex) and 4% of ammonium benzoate was diluted with 5 mL of sterile distilled water at room temperature.
Preferred Example 7 (Ex 7)
[0100] 5 grams of soap composition of Table 5 with 1 ppm of Ag 2 O (as silver DTPA complex), 2% of ammonium benzoate and 2% ammonium citrate was diluted with 5 mL of sterile distilled water at room temperature.
Preferred Example 8 (Ex 8)
[0101] 5 grams of soap composition of Table 5 with 1 ppm of Ag 2 O (as silver DTPA complex), 2% of ammonium benzoate and 2% sodium citrate was diluted with 5 mL of sterile distilled water at room temperature.
[0102] The silver DTPA complex as mentioned above was prepared by using 1.500 g of Silver oxide powder with 22.5 g of 40% Na5DTPA (Sodium salt of diethylene triamine pentaacetic acid). The above mixture was stirred and heated at ˜45° C. in a water bath for 10 minutes. Any particulates observed are broken with glass rod. After that 975 g of water was added water stirring ambient temp (˜25° C.). The stirring was continued for 10 minutes. After that 0.8 g of powdered lauric acid was added and stirred for 30 minutes. The resulting mixture was centrifuged to separate out the supernatant from the residue for 5 minutes. The supernatant is silver DTPA complex used in the experiments.
[0103] The assay protocol is same as described in the previous section.
[0000]
TABLE 6
Biocidal activity
Log 10 Reduction against S. aureus ATCC 6538
Contact time
Example
Composition
(10 seconds)
Comp 5
Fatty acid Soap + 1 ppm Ag 2 O (as Silver
1.7
DTPA complex)
Ex 6
Fatty acid Soap + 1 ppm Ag 2 O (as Silver
2.4
DTPA complex) + 4% Ammonium Benzoate
Ex 7
Fatty acid Soap + 1 ppm Ag 2 O (as Silver
3.2
DTPA complex) + 2% Ammonium Benzoate +
2% Ammonium citrate
EX 8
Fatty acid Soap + 1 ppm Ag 2 O (as Silver
3.4
DTPA complex) + 2% Ammonium Benzoate +
2% sodium citrate
[0104] The data in Table 6 demonstrates that, at the indicated contact time of 10 seconds, the preferred compositions Ex 6, Ex 7 and Ex 8 had greater bactericidal efficacy against S. aureus ATCC 6538 than the comparative composition (Comp 5). | The present invention relates to an antimicrobial cleansing composition and a method of cleaning or disinfecting a surface. The invention more particularly relates to an antimicrobial cleansing composition that provides antimicrobial efficacy in cleaning applications having relatively short contact times. An object of the present invention is to provide an antimicrobial cleansing composition that exhibits biocidal activity in relatively short contact times of 1 minute to 10 seconds. Another object of the present invention is to provide an antimicrobial cleansing composition which exhibits antimicrobial activity at very low concentration of silver compound. A further object of the present invention is to provide an antimicrobial cleansing composition which has consumer-acceptable aesthetic properties. A still further object of the present invention is to provide an antimicrobial composition that is highly efficacious against a broad spectrum of gram positive and gram negative bacteria. We have determined that antibacterial activity in relatively short contact times against gram positive and gram negative microorganisms in a soap based cleansing composition having silver compound enhances considerably in presence of a further salt of carboxylic acid. It has been additionally found that the antibacterial activity is enhanced even at very low concentrations of silver compound. | 2 |
BACKGROUND OF THE INVENTION
The invention is related to a circuit arrangement to detect knocking in an internal combustion engine, and particularly, to a circuit arrangement having a knock sensor which is connected with an evaluating circuit via a filter effecting a separation of the knock frequency.
In automotive engineering, knocking in an internal combustion engine is a dangerous operating state which can lead to damage in the long run. Therefore, circuit arrangements to detect knocking in an internal combustion engine are known which determine the frequency spectrum of the internal combustion engine by means of a knock sensor and, after filtering out the relevant knock frequency, feed it to a circuit arrangement which, when knocking is detected, changes the operating parameters of the internal combustion engine in such a way that knock-proof operation is brought about. Increasingly greater demands are made with respect to the detecting and evaluating devices of the known circuit arrangements. For example, increasingly higher knock frequencies must be determined and evaluated as a result of modern internal combustion engine construction. This conflicts with the relatively low limit frequencies of the evaluating circuits presently in use. In addition, there is a demand for arrangements for evaluating the knock sensor signals which are constructed in a particularly simple manner.
SUMMARY OF THE INVENTION
In contrast to the known circuit arrangements, the circuit arrangement according to the invention has the advantage that a simple and accordingly inexpensive construction of the entire circuit arrangement is possible in spite of the relatively high frequency of the knock sensor signal, since a frequency reduction is effected so that a relatively simple technique can be used. According to the invention, the reduction in frequency is effected with a means for superposing which works according to the principle of superposition (beat principle, superheterodyne principle) and accordingly lowers the frequencies of the knock sensor signal components. This reduced frequency mixed signal is then fed to the evaluating circuit via filter means.
According to a further development of the invention, the means for superposing receives another signal at an oscillator frequency of the same magnitude as the predominant knock frequency for mixing or superposition with the knock sensor signal. The advantage of this consists in that a mixed signal is available at the output of the superposing means which corresponds to the envelope curve of the knock signal.
It is also possible to operate the superposing means with an oscillator frequency which diverges from the knock sensor signal frequencies in such a way that the mixed signal frequencies of the output signal of the mixer stage is less than the sensor signal frequencies. This frequencies reduction then enables a further processing of the signal using simple means. The oscillator frequency can be below or above the frequency of the anticipated knock signal by an amount corresponding to the desired filter frequency of a subsequently arranged filter means (band-pass filter). As has already been mentioned, the advantage of this signal processing consists in that knock signals of very high frequencies can be processed, wherein no special demands are to be made on the further signal processing with respect to the frequency processing characteristics.
The means for superposing comprises a mixer stage multiplier. The knock sensor signal, which is composed of ground noise and possible knock signals, and the oscillator frequency--as additional input quantity--are fed to this mixer stage multiplier. The output of the multiplier is connected to the evaluating circuit.
In particular, a level stabilizing circuit can be connected between the superposition means and the knock sensor. This ensures that the knock sensor signal, whose amplitude depends on the operating state of the internal combustion engine, is brought to a constant level and then subjected to further processing. Fluctuations in amplitude of the knock sensor signal are, e.g. speed-related and are also dependent on the operating hours of the internal combustion engine (aging). These fluctuations are caused by the spread and tolerances of the component elements.
According to a preferred embodiment of the invention, the level stabilizing circuit comprises a stabilizer circuit multiplier which receives the knock sensor signal and a regulating signal of the evaluating circuit as input quantities. The regulating signal is supplied by a regulator circuit which makes up part of the evaluating circuit. Accordingly, a constant level is always ensured at the output of the level stabilizing circuit as a result of the regulator circuit.
In particular, it can be provided that the evaluating circuit is constructed as a microcomputer. This can be e.g. part of a control device of the internal combustion engine.
The regulator circuit of the microcomputer is preferably connected to the level stabilizing circuit via an averaging means. This averaging element is required for obtaining a direct voltage component from the logical signal originating from the microcomputer, which signal is particularly a pulse-width modulated signal, preferably a pulse-width modulated square wave signal. This is effected by finding the mean value of the pulse-width modulated signal. The averaging means is preferably formed by an RC network.
The filter means mentioned in the beginning, which filters the relevant knock frequency out of the knock sensor signal is constructed, according to the invention as a low-pass filter.
This advantage of the construction according to the invention is that the band-pass filter (knock filter) known from the prior art can be dispensed with. Moreover, a very simple low-pass filter, preferably of the first order, is sufficient for the signal filtering. This is the case particularly when--as was previously the case--a knock filter of only very low quality (e.g. Q=3) is used. Accordingly, the arrangement of the invention also provides a particularly simple applicability: instead of adjusting the knock filter mean frequency (band-pass filter) and the knock filter quality, as was previously the case, the parameters for the oscillator signal and the low-pass cut-off frequency can be determined, according to the invention, in a simple manner. The latter can be adjusted in a simple manner and without feedback, for example, by means of a trimmer. The low-pass filter, according to the invention, eliminates high-frequency unwanted mixing products.
According to a preferred embodiment of the invention, the low-pass filter is formed by an RC network.
OTA components (operational transconductance amplifiers) are preferably used as mixer stage and stabilizing circuit multipliers.
In the previously described construction variants, it is possible that there will be no synchronism between the oscillator signal and the knock signal. As a result of this absence of synchronism, a generation not only of the envelope curve of the knock signal alone, but also of a beat frequency, is effected. Consequently, there is no distortion-free demodulation, although this is not essential, since the level is utilized for detecting a knocking state. However, the beat frequency can also result in a "zero" value and consequently, in the impossibility of detecting knocking. However, this beat frequency can also be avoided when the knock signal is fed to two mixer stages which are operated at the same oscillator frequencies having different relative phases. Accordingly, it is always ensured that any knocking taking place is detected and the corresponding countermeasures can be taken. In particular, the phase angle difference is 90°.
Two clock signals which are out of phase by 90° can be assigned to the two oscillator frequencies; that is, these clock signals can be the other signals which are mixed with the knock sensor signal and which have the aforementioned oscillator frequencies. In particular, it is advantageous if the clock signals are supplied by the aforementioned microcomputer. This is then a matter of logic signals. The microcomputer accordingly supplies the two clock signals which are out of phase by 90° relative to one another.
However, as an alternative to this, it is also possible to form the clock signals from a time base signal of double the frequency by two frequency divider means. One frequency divider means is triggered by the positive flank and the other is triggered by the negative flank of the time base signal. The two clock signals which are out of phase by 90° relative to one another are accordingly obtained from the base clock signal by means of this different triggering of the frequency divider means.
Further, it is possible to connect the outputs of the two multipliers to a low-pass filter in each instance and to combine the low-pass filter outputs by means of a combinatorial circuit. The combinatorial circuit is preferably constructed as a summing or connection point. Consequently, two multipliers and two low-pass filters are required. A common signal is first formed again from the output signals of the two low-pass filters by the combinatorial circuit, which common signal is then subjected to further processing. Alternatively, the outputs of the two multipliers, each of which receives the signal formed by the level stabilizing circuit, are combined by means of the combinatorial circuit and the output of the combinatorial circuit leads to a low-pass filter. To this extent, only one low-pass filter is necessary in this case, instead of the aforementioned two low-pass filters.
The computing cost of the evaluating circuit can be reduced when a threshold switch is connected between the low-pass filter and the evaluating circuit. The threshold switch registers whether or not the level is exceeded by a set value. This task need no longer be carried out by an analog-to-digital converter with a stored comparison value, so that the computing load is smaller. For an accurate knocking effect, it is then only necessary for the computer to determine the sum of times the level is exceeded per unit of time and accordingly, to enable an accurate detection of a knocking state. The computer then need no longer carry out a comparison with a set value, etc.
Alternatively, it is also possible to connect a rectifier and a subsequent integrator between the low-pass filter and the evaluating circuit instead of the threshold switch. Accordingly, the computing expenditure for the microcomputer is still further reduced; a kind of evaluation utilizing hardware is effected for the most part. The rectifier is required for ensuring that the integrator does not "integrate down" further when there are negative signals. The microcomputer, which is connected to the output of the integrator, need only decide whether or not the integration value exceeds a set value. If the set value is exceeded, a knocking state exists. The operation of the microcomputer can therefore be compared with that of a comparator.
The present invention both as to its construction so to its mode of operation, together with additional objects and advantages thereof, will be best understood from the following description of preferred embodiments when read with reference to the accompanying drawings.
BRIEF DESCRIPTION OF THE DRAWINGS
FIG. 1 shows a schematic first embodiment of a circuit arrangement according to the invention for detecting knocking in an internal combustion engine;
FIG. 2 shows the circuit arrangement of FIG. 1 in more detail;
FIG. 3 shows another embodiment of the circuit arrangement;
FIG. 4 shows still another embodiment of the circuit arrangement;
FIG. 5 shows still another embodiment of the circuit arrangement;
FIG. 6 shows still another embodiment of the circuit arrangement;
FIG. 7 shows still another embodiment of the circuit arrangement;
FIG. 8 shows still another embodiment of the circuit arrangement;
FIG. 9 shows still another embodiment of the circuit arrangement; and
FIG. 10 shows still another embodiment of the circuit arrangement.
DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS
FIG. 1 shows a basic circuit diagram of one embodiment of the circuit arrangement according to the invention. This circuit arrangement serves to detect knocking in an internal combustion engine. It comprises a knock sensor (not shown) having a knock sensor signal KS fed to a level stabilizing circuit 1. The level stabilizing circuit 1 is constructed as a multiplier 2. The latter receives a regulating signal K as additional input quantity. The regulating signal K is supplied by an evaluating circuit 3. This will be discussed in more detail in the following.
The output 4 of the multiplier 2 is connected with an input 5 of a mixer stage 6. The mixer stage 6 is likewise constructed as a multiplier 7. To this extent, the multiplier 7 is a mixer stage multiplier and the multiplier 2 is a stabilizer stage multiplier.
The mixer stage multiplier 7 receives an oscillator frequency f clock of a clock signal T as additional input quantity. The following relationship applies to the clock signal T:
Usinω.sub.K t
where
ω.sub.K =2 πf.sub.knock.
Like the regulating signal K, the clock signal T originates from the evaluating circuit 3. The mixer stage 6 is a means for superimposing or mixing a leveled knock signal KS having a knock signal frequency with another signal having the oscillator frequency f clock .
The output 8 of the mixer stage 6 is connected with a filter 9 which is constructed as a low-pass filter TP. It is preferably a low-pass filter of the first order, which can be realized in a simple manner by an RC network. The output 10 of the filter 9 leads to the evaluating circuit 3.
The arrangement is constructed in such a way that a substantially constant level is generated at the stabilizer stage multiplier 2 by means of the regulating signal K at the output 4. This means that the knock sensor signal KS, whose amplitude fluctuates as a result of the different operating states of the internal combustion engine, etc., is regulated at a constant level. The output signal of the stabilizer stage multiplier 2 then reaches the mixer stage multiplier 7 which forms the mixer stage 6 and therefore carries out a superposition with the clock signal T according to the superposition principle (superheterodyne principle). The frequency (oscillator frequency f clock ) of the clock signal T is selected so as to be just as great as the anticipated knock frequency f knock of the internal combustion engine. The mixed signal thus obtained contains, among other things, the information characterizing the knocking state and in this instance has a mixed signal frequency in an audio-frequency range. A signal is obtained which corresponds to the envelope curve of the knock signal. This can be further processed using simple means. The mixed output signal of the mixer stage 6 is directed via the low-pass filter TP9 in order to eliminate high-frequency unwanted mix products. The signal originating from the filter 9 is then evaluated in the subsequent evaluating circuit 3 with respect to a possible knocking state of the internal combustion engine.
FIG. 2 shows the circuit arrangement of FIG. 1 in a more detailed manner. It can be seen that the knock sensor signal KS is fed through a preliminary filter means comprising an RC network 11 to obtain a signal which is comparatively insensitive to interfering noise signals and oscillator harmonics from the mixer stage (secondary reception points). FIG. 2 shows further that the low-pass filter TP can be realized by means of an RC network 12. The evaluating circuit 3 is constructed as a microcomputer μC. For the purpose of generating the regulating signal K, the microcomputer has a regulator circuit 13 which receives an actual set value u actual as input quantity from the signal originating from the filter 9, which signal is fed to an analog/digital converter (A/D converter) of the microcomputer μC. A control voltage U control which is fed to an averaging element 14 constructed as an RC network 15 is available at the output of the regulator circuit 13. The mean value of the control voltage U control is the regulating signal.
The averaging element 14 is required, since the control voltage U control can only assume logical states. This is a matter of a square wave signal whose pulse width is modulated for the control function. The greater the pulse width, the higher the mean value at the averaging element 14 which is a direct voltage which is multiplied by the knock sensor signal KS at the stabilizer stage multiplier 2 in order to form an approximately constant level.
The oscillator frequency f clock is a square pulse train. This is likewise indicated in FIG. 2. This square pulse train leads to the aforementioned high-frequency mixing products which are, however, eliminated by the low-pass filter TP.
In the circuit arrangement of FIG. 2, a relatively large computing expenditure is required in the microcomputer μC, since all of the signal processing is effected in the latter. The A/D conversion time of the aforementioned analog/digital converter is to be selected so as to be small enough to fulfill the sampling theorem to a sufficient extent. This is carried out by commercially available A/D converters. The processing of the knock signal is effected by means of the software of the microcomputer μC (summing, integration through summation, evaluation, etc.).
The use of the aforementioned square wave signals can cause the aforementioned reception of higher harmonics from the mixer stage 6. This would not occur if a sine voltage were utilized as clock signal T. Of course, the low-pass filter TP prevents a negative effect of the aforementioned higher harmonics.
Commercially available operational transconductance amplifiers (OTA's), which can process knock signals of very high frequency, are preferably used as multipliers 2, 7. PG,12
FIG. 3 shows another embodiment example of the circuit arrangement, according to the invention, in which the microcomputer μC has less computing work to accomplish, since an evaluation of the knock sensor signal KS is effected partially with the use of hardware.
FIG. 3 differs from FIG. 1 substantially in that a threshold value switch S is connected between the low-pass filter TP and the microcomputer μC. This threshold value switch S detects when a normal level (set value) is exceeded and then triggers an interrupt. The threshold value switch S can have a hysteresis, as indicated in FIG. 3. The response level can be constant or--as shown in FIG. 3--can be influenced by the magnitude of the control voltage U control . This circuit variant eliminates the need for the analog/digital converter of the microcomputer μC, since the decision about whether or not the level is exceeded, which implies a knocking, is made by the threshold value switch S. However, the exact knocking evaluation is carried out by the computer which determines the sum of the number of times the level is exceeded per unit of time and decides from this whether or not the internal combustion engine is knocking.
FIG. 4 shows another variant which requires less computing capacity. Instead of the threshold value switch S, a rectifier GL and integrator I are connected between the low-pass filter TP and the microcomputer μC. In particular, the rectifier GL is an envelope curve detector, whose input 16 is connected to the low-pass filter TP. The output 17 of the rectifier GL is connected to the negative input 18 of an operational amplifier OP via a resistor R. An integrating capacitor C Int leads from the negative input 18 to the output 19 of the operational amplifier OP. A switch SCH which is switched by a measuring window MF of the microcomputer μC lies parallel to the integrating capacitor C int . Accordingly, it is ensured that the integration always only takes place immediately after ignition of the internal combustion engine.
Accordingly, the signal processing is effected to a great extent in the circuit arrangement according to FIG. 3 with the use of hardware. The microcomputer μC need only decide whether or not the integration value at the output 19 exceeds a set value, so that a conclusion can be reached as to whether or not there is knocking in the internal combustion engine. Consequently, the operation of the microcomputer μC is comparable to that of a comparator in this respect.
The knock vibrations to be detected occur as a result of cavity resonances in the residual volume of the corresponding cylinder of the internal combustion engine. In this instance, residual volume is understood to mean the volume present in the top dead center position. For such cavity vibrations, the solution to the respective wave equation is a group of solutions, that is, waves whose half and odd-number multiples of the half wavelength "fit into" the aforementioned cavity, for example, can also resonate. It would be conceivable to convert these harmonic oscillations into the audio range by means of a suitable clock signal containing harmonic waves so as to further improve the signal-to-noise ratio.
The advantages of the invention are based on the use of commercially available OTA's as multipliers 2 and 7. A simple low-pass filter TP of the first order, instead of the band-pass filter (knock filter) previously utilized in the prior art, is sufficient due to the convoluting or mixing with the other signal from the mixer stage of the knock signal in the frequency range. The circuit can be applied in a simple manner. The filter parameters of the low-pass filter TP and oscillator frequency f clock can be adjusted independently and without feedback. Due to the low processing frequency, the signal processing can be carried out in the microcomputer μC to a great extent without requiring a particularly great computing expenditure. As has already been mentioned, there is also the possibility of determining the harmonic waves of the knock signal as an additional source of information.
It is also possible, in principle, to replace the mixer stage multiplier 7 and the stabilizer stage multiplier 2 with a single multiplier. The circuit expenditure is accordingly further reduced.
The embodiment of FIG. 5 differs from the previous embodiments in that an oscillator frequency f clock is selected for the clock signal T which does not conform to the frequency of the anticipated knock signal. Rather, a reduction of the relatively high frequency of the knock sensor signal KS to a lower frequency which can then be further processed using simple means is effected according to the superheterodyne principle. For the rest, the construction of the arrangement of FIG. 5 corresponds to the embodiment example of FIG. 4, wherein instead of the low-pass filter TP--as was conventional in the prior art--a knock filter KF, i.e. a band-pass filter, is used. The frequency of the clock signal T fed to the mixer stage can be below or above the frequency of the anticipated knock signal by an amount corresponding to the desired knock filter frequency (knock filter KF). The advantage of this signal processing consists--as was already mentioned--in that knock signals of very high frequency can be processed, wherein the additional signal processing makes no special demands with respect to speed (slew rate of the component elements).
Another embodiment example which is shown in FIG. 6 has two mixer stages 6 and 6' instead of one mixer stage. The inputs 5 and 5' of these mixer stages 6 and 6', which are likewise constructed as multipliers 7 and 7', are both connected to the output 4 of the level stabilizing circuit 1. The clock signal T is fed to the multiplier 7 and a clock signal T' is fed to the multiplier 7', wherein the phase relation of these two clock signals T, T' differs by 90°. The following relationship applies to the clock signal T:
Usine (2πf.sub.K t).
The following relationship applies to clock signal T': ##EQU1## wherein f K is the knock frequency. The outputs 8 and 8' of the multipliers 7 and 7' lead to a low-pass filter TP and TP', respectively, whose outputs 10 and 10' are connected to a combinatorial circuit 20. The combinatorial circuit 20 is preferably constructed as a summing or connection point 21. The output 22 is then fed to the evaluating circuit 3 in the conventional manner.
The arrangement in FIG. 6 ensures that the absence of synchronism between the clock signal and the knock signal does not render it impossible to evaluate knocking. As a result of this absence of synchronism in the evaluation of knocking it can come about that additional beat frequencies occur rather than the envelope curve being present alone. Accordingly, no distortion-free demodulation occurs; but this is unimportant, since the information concerning a knocking combustion consists in the exceeding of a determined amplitude value assigned to the normal ground noises. Such increases in amplitude can also be detected in the presence of beat frequencies. However, the beating can also lead to an output value of "zero" at least periodically. In this case, no knock sensing can be carried out. The circuit arrangement of FIG. 6 prevents such a situation, i.e. the aforementioned special case where the product is "zero" does not occur when two signals are multiplied. The two multipliers 7 and 7', which are operated with two oscillator frequencies f clock , f' clock which are out of phase by 90° are used for this purpose. This involves so-called quadrature modulation.
FIG. 7 shows an entire circuit similar to FIG. 2 whose structure is outlined in is taken into account. In an unshown alternative the two low-pass filters TP and TP' can be replaced by a low-pass filter TP" which is connected to the output 22 of the combinatorial circuit 20 and is connected with the microcomputer μC by its output 10".
As has already been mentioned, it is necessary to use two clock signals T, T' which are out of phase by 90° relative to one another in order to avoid beating which can lead to an output signal with the value "zero". FIG. 8 shows a preferred embodiment example for this case. It is possible in principle for the microcomputer μC to generate oscillator frequencies f clock and f' clock which are out of phase by 90° relative to one another. Alternatively, in the preferred embodiment example of FIG. 8, the microcomputer μC generates a time base clock signal GT which has twice the frequency of the clock signal T and T', respectively. Two frequency dividers 23 and 24 are provided, the base clock signal GT being fed to the latter as input signal. One frequency divider is triggered by the positive flank of the base clock signal GT, the other frequency divider is triggered by the negative flank of the base clock signal GT. As a result, clock signals T and T', which are out of phase by 90° relative to one another, are available at the outputs 25 and 26 of the frequency dividers 23 and 24. These clock signals T and T' are then fed to the multipliers 7 and 7' in a manner which has already been described. FIG. 8 shows two low-pass filters TP and TP'; however, as an alternative, it is also possible--as has already been mentioned--to provide only one low-pass filter TP" at the output of the combinatorial circuit 20 instead of the two low-pass filters TP, TP'.
The aforementioned 90° separation can be a component part of the microcomputer μC in the integrated knock evaluation circuit; there is then no extra expenditure on peripherals.
FIG. 9 shows an embodiment example in which a threshold value switch S is used--corresponding to the embodiment form of FIG. 3. The preceding statements can be referred to with respect to its further construction.
Finally, FIG. 10 concerns an embodiment form corresponding to that of FIG. 4; that is, a rectifier GL and an integrator I are provided.
While the invention has been illustrated and described as embodied in a circuit arrangement to detect and evaluate knocking in an internal combustion engine, it is not intended to be limited to the details shown, since various modifications and structural changes may be made without departing in any way from the spirit of the present invention.
Without further analysis, the foregoing will so fully reveal the gist of the present invention that others can, by applying current knowledge, readily adapt it for various applications without omitting features that, from the standpoint of prior art, fairly constitute essential characteristics of the generic or specific aspects of this invention. What is claimed as new and desired to be protected by Letters Patent is set forth in the appended claims. | The circuit arrangement for detecting and evaluating knocking in an internal combustion engine includes a knock sensor located in the internal combustion engine to generate a knock sensor signal having knock signal frequency components of differing knock signal frequencies; an oscillator producing a constant frequency oscillator signal; a mixer stage producing a mixed signal including mixed signal frequency components of various mixed signal frequencies which are less than the corresponding knock signal frequencies of the knock sensor signal, the mixer stage being connected to receive the constant frequency oscillator signal and the knock sensor signal; a level stabilizing circuit for adjusting an amplitude of the knock sensor signal to a constant amplitude level despite changes in an operating state of the internal combustion engine, the level stabilizing circuit connecting the knock sensor and the mixer stage; a filter circuit connected to the mixer stage to filter the mixed signal and form a filtered mixed signal including filtered mixed signal components at the mixed signal frequencies; and an evaluating circuit connected to the filter circuit for analysis of the filtered mixed signal. | 6 |
CROSS-REFERENCE TO RELATED APPLICATION
Application Ser. No. 956,428 by Rudolf Schaefer, filed Oct. 31, 1978 pertains to related subject matter.
BACKGROUND OF THE INVENTION
The invention relates to a refrigerating or warming cabinet which is detachably assembled from single flat wall elements, having groove-tongue connections formed in the connecting areas.
SUMMARY OF THE INVENTION
A container of this type known from the Austrian Pat. No. 119 563 serves as a refrigerator and is built up from single parts in a unit-composed way. The wall elements herein are fastened together by way of hooks.
The wall elements are covered in the area of the grooves and tongues with sealing material in order to provide insulation in these edge areas. The solidity of this known refrigerator is most unsatisfactory, this being maintained by hooks alone. Neither is the insulation in the bordering edge area sufficient, at least over a longer period of time, since from experience elastic sealing material loses its elasticity after some time so that the insulating effect diminishes accordingly. The assembly is also tedious since the grooves and tongues, which are rectangular in cross-section, are difficult to join in place.
The object of the invention is to construct a container of the above mentioned type in such a way that it is more easily assembled and taken apart again and has a complete and lasting impermeability when assembled.
Energy-saving, easily assembled, insulating climatic storage cells, which are by water and/or steam operated, are created up to high capacity which are connected into the supply pipe network and use the energy therein before and/or after use.
Preferably, it is proposed that the wall elements are held together by means of two clamping bands which encircle the cabinet body and can be closed by a releasable lock. In such a construction the actual cabinet body has a very high degree of solidity, when assembled, even when in addition to the groove and tongue connections only clamping bands are used. As these can be handled considerably more easily than hooks or screw connections, the assembly and also the dismantling of the container is correspondingly simple. A good insulating effect is also provided in the connecting area of the edges in wall elements manufactured from suitable insulating plastic without, additional insulating strips having to be inserted. Since it is possible to produce the grooves and tongues on the wall elements by machine without great expense, the container can be manufactured at a low price.
It is of further advantage that two clamping bands are provided which each run around the cabinet body in a plane in which the two wall elements provided with grooves and tongues on their narrow sides lie. The tension force from the clamping bands is therefore only effective in the plane of those wall elements where the grooves and tongues run in the narrow sides as well as on the two remaining wall elements in directions running vertically to this plane. However, no force components occur which could cause one of the wall elements to be pressed out of the right-angled relationship.
The cabinet body favorably produced in the above way is converted into a refrigerator without its own cooling aggregate by conducting the drinking water removed from the rising mains in the basement through it. The proposed assembly of the refrigerator or several refrigerators forming a battery in the basement of the house guarantees a high cooling capacity.
In the same way the entire waste hot water flowing off (e.g. from washing machine or dishwasher etc.) can be directed through a relay before it reaches the drain, through corresponding heat and/or cooling regenerators (without refitting the equipment) and be used, for example, for the following sectors:
(a) in the catering trade: storage of foodstuffs and delicacies, particularly of wines, or for keeping the crockery warm;
(b) in canteens, works kitchens etc.: for keeping meals warm;
(c) in laboratories in research centres and clinics for breeding cultures etc.;
(d) in private households: for thawing out frozen food and drying washing--a problem in large families in cold and humid rooms.
Large-capacity dry cells are made by assembling a drying chamber in which corresponding heat regenerators are present. These heat regenerators are connected to a separate hot water outlet pipe. This can be installed without great extra cost in new buildings. Such energy-saving equipment can also be installed in old buildings.
Further advantageous developments of the invention are given in the sub-claims.
An embodiment of the invention is shown in the drawings and is described in more detail below.
BRIEF DESCRIPTION OF THE DRAWINGS
FIG. 1 shows a schematic representation of a front view of a connected refrigerating or warming cabinet;
FIG. 2 shows a side view of the representation of FIG. 1;
FIGS. 3 to 5 show views of parts of individual wall elements in the area of the groove-tongue connections;
FIG. 6 shows the assembly of two refrigerating or warming cabinets in schematic representation.
DESCRIPTION OF THE PREFERRED EMBODIMENTS
A first wall element 10 serves as rear side and forms the actual cabinet body with a further four wall elements 11,12,13 and 14, while a further wall element 15 is constructed in the form of a door. All wall elements 10 to 15 are manufactured from a good heat-insulating plastic, e.g. a rigid expanded plastic. They may also be at least partly coated with a plastic film which is not represented here.
The first wall element 10 forming the back side is provided on its inner side, as can be seen especially from FIG. 3, with continuously encircling grooves 16 and tongues 17 which merge into one another at the corners at an angle of 90°. Two tongues 17 in each case run parallel to each other, whereby a groove 16 is formed between them.
The two wall elements 11 and 12 constructed as side wall each have on their narrow sides set on the first wall element 10 two grooves 18, between which a tongue 19 runs. Wall elements 11 and 12 each have two tongues 20 on their inner sides to be connected with wall elements 13 and 14, said tongues 20 forming a groove or auxiliary groove 21 between them. The latter merges into the tongues 19 on the narrow side facing the first wall element 10, while the tongues 20 merge with the grooves 18 on an equal incline towards the same side.
Conversely, such a changeover is not present in the case of wall elements 13 and 14, as these each have continuously encircling grooves 24 on all four narrow sides which form a tongue or auxiliary tongue 25 between them.
In the respective outer edge areas of the groove-tongue connections the grooves 21 or tongues 25 each have only half the cross-section in comparison with the middle area.
As can be seen from all the figures, the groove-tongue connections have a frusto-conical cross-section. They are moreover constructed in such a way that the assembled wall elements 10 to 15 each always interlock in two directions.
The wall elements 10 to 15 assembled to form a cabinet body are held together by means of two flat clamping bands 26 and 27 of steel which can be closed at their ends by means of a respective clamping lever lock 28 which can be operated easily by hand. On the outer sides of the wall elements 10,11 and 12 correspondingly dimensioned shallow grooves 29 are provided, into which the clamping bands 26 and 27 can be inserted so that they do not project outside and can not slip. The upper clamping band 26, therefore, encloses at the same time the wall element 13 serving as the upper cover plate while the lower clamping band 27 at the same time encloses the wall element 14 serving as base plate or lies in the same plane with this. Thus, the forces from the clamping bands 26 and 27 are transferred in the area of the tongues 20 and grooves 21 of the lateral wall elements 11 and 12 and the grooves 24 and tongues 25 formed on the narrow sides of the upper and lower wall element 13 or 14 in such a manner that the respective wall elements bordering on one another are held together everywhere, thereby closing the form completely, without it being possible for them to be pushed against each other. This leads to a particularly high degree of stability in the assembled cabinet body.
A bracket 30 which projects forwards and is provided with a bore 31 is attached in each case to the upper and lower narrow sides of the lateral wall elements 11 and 12. The wall element 15 serving as door corresponds in size to the rear wall element 10 and thus fits exactly between the brackets 30. The wall element 15 has a handle 32 and a lock 33 adjacent one longitudinal side; on the opposite impact side bores are arranged on the top and bottom which are possibly reinforced by sleeves or similar and are not shown here in detail. This permits a pin 34 to be directed through each of the bores 31 positioned in two respective brackets 30 lying one above the other, said pin 34 meshing into the bores of the wall element 15 and serving as door hinge. In the case of the embodiment shown in FIG. 1 the wall element 15 is fastened on the left-hand side. It can, if necessary, be turned so that the handle 32 is on the left-hand side and the right-hand brackets 30 serve as door hinge.
The wall element 13 serving as upper cover plate is provided with two passage connecting sleeves 35 and 36, to the inner side of which the two ends of a pipe system 38 serving as cooling aggregate are connected by way of union nuts. The pipe system 38 runs with one part 38a along the wall element 10 serving as back side while its other part 38b is arranged below the upper wall element 13. An outlet tap 39, by means of which water can be drained into an indentation 40, is provided at the deepest point of a coil of part 38a. The indentation 40 is formed in the wall element 14 serving as base plate. If the inside of the refrigerating cabinet is to have a greater air humidity content, then water is introduced accordingly in the bath-shaped indentation 40.
On the ends of the connecting sleeves 35 and 36 projecting upwards two connecting pipes 41 and 42 are connected, also by using union nuts 37, which are connected with a water main 45 by hand valves 43 and 44. In the latter a by-pass valve 46 is connected between the two connection points so that the flow of cold water through the pipe system 38 can be predetermined in the desired way by correspondingly adjusting the three valves 43,44 and 46. This connection area can be easily separated off from the water main 45 by way of detachable coupling sleeves 47. If the refrigerator is to be connected at a different point, then a bridging pipe should be connected. A particularly effective cooling is provided if the refrigerator is connected to the water main 45 before any rising main is branched, so that the entire cold water requirement of an appartment or house can be applied for cooling.
The wall element 15 serving as door covers, as already mentioned, at top and bottom the part of the clamping bands 26 and 27 running there. On each of the two front narrow sides of the lateral wall elements 11 and 12 a steel rail 49 is disposed so that independent of whether the door wall element 15 is attached on the left- or right-hand side, the corresponding parts of the clamping bands 26 and 27 connected with one of the steel rails 49 at any rate form a continuous steel support which can work together with magnets set into the door wall element 15 at a corresponding point as a magnetic lock.
Support rails, 50, which run vertically and parallel to one another and which are provided with distributed openings 51 of the same modular dimension, are attached to the insides of the lateral wall elements 11 and 12. Small support brackets 52 can be suspended in these openings 51 and then carry for their part intermediate bases 53. The latter can thus be arranged at the respective level required and spaced from one another as respectively desired.
In the present case the refrigerator is fitted to store wine bottles. The intermediate bases 53 each have two eyelets 54 on their front edge, on each of which a number board 55 can be hung. The latter can, for example, be printed with numbers which, horizontally, mark the individual storage positions for the bottles. These markings can be made to tally with a correspondingly kept card index, so that the contents of the refrigerator can be surveyed at all times.
FIG. 6 shows how two adjacent refrigerators can be easily connected to one another mechanically and electrically. In the inner area the lateral wall elements 11 and 12 each have a bore 56 which can be closed with a dummy plug 57 composed of insulating plastic material, should a connection with a second refrigerator not come into question on the respective side. However, if this is the case, the dummy plugs 57 of two wall elements 11 or 12 bordering on one another are removed so that a connecting bolt 58 can be directed through and tightened.
As the two pipe systems 38 are connected one behind the other for expedience, a rigid, U-shaped connecting pipe 59 is connected to the output side connection sleeve 36 of the left-hand refrigerator and on the input side connection sleeve 35 of the right-hand refrigerator, said connecting pipe 59 at the same time holds the two refrigerators together in the upper area. Hoses 60 can also be used as connection pipes to the water main 45 (not shown here), which renders the location of the two refrigerators more independent of the position of the respective water main.
As can be seen from this description, assembly and dismantling of the refrigerator can be carried out by anyone without using any tools. With the exception of the wall elements themselves only commonly available materials are needed. But the machine manufacture only demands a small technical expense. They are considerably more favorable in initial cost than the refrigerators previously used. In addition, operation costs, e.g. due to electricity consumption, do not occur for the refrigerator according to the invention. | A refrigeration or warming cabinet having detachably assembled flat wall elements. On each flat wall element is located a plurality of groove-tongue connections formed in the connecting areas. At least one wall element has, in addition to the groove and/or tongue positions on the front side, grooves and/or tongues on one side surface. The grooves and tongues have an approximate trapezoidal cross section and run continuously along the edges of the wall elements in such a manner that in the corner areas the grooves and/or tongues of the side surfaces of one of the wall elements merges into the tongues and grooves of the front side of another of the wall elements. | 4 |
BACKGROUND OF THE INVENTION
The present invention relates to a forming box to be used by dry forming of a fibrous tissue and encompassing an inlet for introduction of a fibre material which has been splitted up and chosen from amongst synthetic fibres and natural fibres and which is mixed into an airstream, and which forming box contains several revolving rollers, which are provided with radially placed spikes.
Various instruments of this type are known, for instance from the description of European Patent Application 0 159 618. The forming box in such a known plant will frequently be a part of the instrument, which makes an essential limitation for the capacity of the whole instrument.
In respect to the placing of the fibres on the underlying forming wire the forming box is provided with a bottom in form of a net or a sieve in the form of a bottom with a number of openings. In order to promote the passage of the fibres to the bottom of the forming box in the intention of achieving an increase of capacity the application of various mechanical elements has been proposed in form of wings and rollers or other scraping or brushing devices, which in an active way lead the fibres to the bottom of the forming box. Although such mechanical devices do give an increase of the capacity attempts have been made through many years to increase the capacity further.
The elaboration of meshes or openings in the bottom of the forming box has been decided from the fibres, which are used for the preparation of the fibrous tissue. There has primarily been some talk of using cellulose fibres in the manufacturing of paper products or nappy products. Thus, there has been a limitation of the length of the applied fibres. In practice it has thus not been possible to use fibres of lengths of more than 18 mm. This has simultaneously implied that there has been a limitation in the type of products that can be manufactured with such an instrument.
SUMMARY OF THE INVENTION
It is the aim of the present invention to show an instrument of the type mentioned in the beginning, which remedies the drawbacks by the known technique, because there is achieved a substantially bigger capacity and the possibility of application of long fibres for the forming of the fibrous tissue.
According to the present invention this is achieved by a forming box, which is unique by having an open bottom for the releasing of fibre material on the forming wire, because the spikes are arranged to partly holding back the fibres against the effect from the suction of the vacuum box.
It has surprisingly been shown that it is possible to manufacture the forming box with an open bottom. The cloud of fibres, which has been formed inside the forming box of single fibres, which are split up and mixed in the air stream, are transferred down onto the underlying wire by application of the rotating spike rollers. In practice it has been revealed that with an instrument according to the invention capacities can be achieved which are 5-6 times bigger than the capacity with corresponding known instruments.
By running the instrument the raw fibres are split up. This can take place in hammer mills or its like. Hereafter the divided fibres which still can contain a few agglomerates are transferred by means of an air stream down onto the system. The air stream is created by means of transport blowers, which are linked with pipes that lead to the forming box. In the forming box the fibres are primarily led in from each side of the forming box and possibly be means of more inlet pipes on each side of the forming box. It is hereby possible to vary the capacity by opening and closing the supply pipes and the supply blowers.
Inside the forming box a cloud of fibres is formed, where the fibres can circulate because of the transport air. The fibres will hereafter be transferred out from the bottom of the forming box and take place on the forming wire, which is moving beneath the forming box. The layer of fibres, which is formed on the forming wire is fixed by means of a vacuum, which is established in the vacuum box, which is under the forming wire in a position opposite to the forming box.
The present invention brings about a forming box with an open bottom, where a partly retention and distribution of fibres is taking place against that suction which is carried out of the vacuum box. This retention and distribution is established by the rotating spike rollers, because the spikes are influencing the fibres. It has hereby surprisingly been shown that a tissue is formed with a very homogeneous thickness on the underlying forming wire. Hence it can be said that the rotating spikes form a movable bottom or active bottom which is to be differentiated from the traditional passive bottoms consisting of a piece of a net or sieve.
The spike rollers will principally have an extension as seen horizontally so that they for practical purposes cover the sectional area of the forming box. However, it has been demonstrated possible to manufacture forming boxes which function satisfactorily, although the spike rollers do not cover the whole sectional area of the forming box.
It is possible to place rollers or axles, on which the spikes are formed with an almost horizontal orientation or with an almost vertical orientation. It is supposed that an orientation with an angle between horizontal and vertical also is possible and can give satisfactory results.
By orienting the rollers or axles horizontally or vertically the spikes will rotate in a vertical plane and a horizontal plane, respectively. This is preferred because of the symmetrically laying down of fibres, so that a tissue with homogeneous thickness is formed over the width of the forming box.
In the present application the term spikes will cover an embodiment with largely thread-formed spikes. However, the issue will also cover plate-formed elements, which also can be designated as wings. Such plate-formed wings will primarily be formed with the expanse placed in a plane orthogonally on the rotation axis of the axle. Alternatively the plates can be formed with a slope or be formed like propellers to bring about an upwards or downwards directed action on the fibre cloud. To facilitate the passage of air to the forming head when wing-formed spikes are applied, the wings can be provided with holes. Such holes can facilitate the passage of air. By appropriate choice of revolving speed and form of holes in the rollers the passage of fibres to such holes can be hindered or limited.
The rotating spike rollers can be placed so that the outer ends of the spikes describe circles that overlap each other or just touch each other. Furthermore, it is possible to vary the intensity of the placing of the spikes in the enveloping direction as well as in the longitudinal direction. By means of these parameters and the number of revolutions for the spike rollers and the air stream it is possible to adjust the capacity of the instrument.
According to the invention the forming box is able to handle very long fibres. The fibre length will not be limited by sizes of meshes, sizes of openings or its similar in the bottom of the forming box. In practice it has therefore been demonstrated possible to handle fibres with lengths of up to 60 mm, and correspondingly it has been demonstrated possible to handle different types of fibres. It is supposed that by further optimisation of the forming box according to the invention it is possible to handle fibres which are even longer. It is thus possible to use the instrument for manufacturing of products which until now not have been possible with a similar type of instrument.
Because of the capacity of the instrument and the possibility of the handling of very long fibres it will be possible advantageously to use the instrument for manufacturing of fibrous layers with a substantial thickness, which for instance can be of the size of order of up to 200-300 mm. It will thus be advantageous to use the instrument for manufacturing of fibrous tissue in form of isolation mats as a new area for air-laid, non-woven products. By the manufacture of these mats very long fibres can be used, which can be synthetic fibres or natural fibre or mixtures hereof. As these fibres can have a substantial length, it will be possible to create a form stable tissue, although it is manufactured with a big thickness. The long fibres can form fibrous bindings over a relatively big layer of material. The bindings can be crispy hydrogen bindings or elastic bindings, which are established by means of binding material or a combination hereof.
It has surprisingly been shown possible to manufacture the products with an improved quality relatively to known products. In products, which are manufactured in an instrument according to the invention, it has thus been shown possible to avoid so-called shadows and agglomerates, which consist of gathered fibre lumps in the product. It is thus surprising that it by means of the instrument has been possible to hold the fibres separated from each other. It is anticipated that this disintegration of agglomerates of a fibrous material is due to influences from strokes that the fibres are exposed to when they by means of the spikes of the rollers are struck upwards in the forming box or downwards against the underlying forming wire.
It has thus been shown possible to form a fibrous product, where problems are avoided with the variation of the thickness over the width of the product, which is formed on the forming wire. It is anticipated that this surprising homogeneity of the thickness of the created product over the width of the product is due to fact that the rotation of the spike rollers leads the fibres directly down against the forming wire in the direction orthogonally on the surface of the forming wire. This homogeneity is achieved, although forming wires with widths of 200 mm to several meters are applied.
As mentioned earlier, the instrument is advantageous because the capacity of the forming box can be adjusted. Hereby the capacity of the instrument can be adjusted dependent of the product which is to be formed, and dependent of the transferring rate, which it is possible to apply for the forming wire without a risk that the formed tissue is blowing away.
The adjustment can in a forming box with horizontally oriented rollers primarily be effected by mounting the rollers mutually displaceable in a substantially horizontal plane and can be placed with a mutual distance, which approximately corresponds to the diameter of the circle, which defines the outer ends of the spikes or is less. It is thus possible to establish clefts, which allow a bigger amount of fibre material to pass within a given unit of time.
When the horizontally oriented rollers are shifted horizontally, so that the outer ends of the spikes are transferred in-between each other, it becomes possible to manufacture a fibrous tissue of very short fibres, for instance with lengths of down to 3 mm. Hereby it becomes possible to achieve a very homogeneous product with a very homogeneous profile in the sectional direction as well as in the longitudinal direction. It is also possible to handle the short fibres, although only a single layer of rollers in the forming box is applied. As mentioned beneath it will also be possible to use more layers of rollers placed above each other in the forming box.
If the forming box is to handle long fibres, for instance with a length of 60 mm or more, it will be advantageous to shift the rollers, so that the circles which define the outer ends of the spikes substantially just touch each other or are a little shifted from each other.
When the spikes of the rollers are arranged to describe overlapping curves the instrument is unique by having the spikes in the longitudinal direction of the rollers with a mutual distance which allows passage in-between for corresponding spikes on an adjacent roller. In respect to a little change of capacity for an instrument it is also preferred that the spikes are placed in shiftable rails which are mounted in axial trails in the roller.
The spikes on each roller will primarily be placed orthogonally on the longitudinal axis of the roller, and over the length of the roller is placed a number of set of spikes. Each of these sets will substantially contain 2-12 spikes and especially 4-8 spikes, which are evenly distributed along the circumference of the roller.
It is possible to use very varying dimensions and revolving rates. It is, however, preferred that the axial distance between the spikes is between 5 and 20 mm, and that the thickness of the spikes is between 0,5 and 10 mm. The length of the spikes will be between 5 and 200 mm, preferably about 100 mm. The rollers are arranged with a variable number of revolutions, which can be regulated, so that it will be within an interval of between 200 and 5000 r.p.m., preferably about 2300-2500 r.p.m.
It will also be possible to use numbers of revolution, lengths of spike and thicknesses of spike, which lie outside these intervals. By varying the length and the thickness of the roller and spikes it is likewise possible to handle long fibres without the risk that they spin into each other. That is, it will be possible to handle the long fibres and get these down on the forming wire as individual fibres, without being spun into each other.
In order to arrange the forming box with horizontally oriented rollers for handling of fibres with various abilities it is possible to provide more layer of rollers. The rollers in each layer can be placed on a row with their longitudinal axis oriented parallelly or orthogonally on the movement direction of the forming wire. The longitudinal axis of the rollers can, however, also be oriented in the direction parallel with the movement direction of the forming wire. By having more layers of rollers on top of each other it is thus possible to achieve an opening of fibres, which otherwise would be difficult to open.
It is also possible to place the rollers in the various layers with different orientation in relation to the rollers in one of the other layers. By applying more layers of rollers it is possible to handle relatively short fibres and at the same time maintaining a big capacity.
When the rollers are placed horizontally they can be arranged so that a substantially hollow cylinder is formed within the forming head. This cylinder is formed because the rollers are brought about within a cylinder expanse, so that a hollow cylinder is formed where the inlet for the fibres is provided on an ending expanse. The fibres are thus transferred into the hollow cylinder, which is formed by the rollers with the placed spikes upon it.
Mainly at least one further roller will be provided, which similarly is provided with spikes and which is arranged within and adjacent to the formed cylinder wall. This allows the fibres to, which are blown into the hollow cylinder, and which can form a border or sausage by the influence of the rotating spikes upon the fibres, in a sure way be distributed along the length of the cylinder. Because the cylinder mainly will be arranged with an extension orthogonally on the direction of transference for the forming wire it will thus be possible to form a fibrous tissue with a very homogeneous thickness across the width of the forming wire.
The spikes upon the rollers in the cylinder expanse or the further roller within the cylinder can be established with such a length that the circumscribed circle which is defined by the outer end of the spikes, substantially touch each other or are slightly overlapping.
Preferably, there will be more cylinders provided. The cylinders will in especially advantageous embodiments be established in pairs, so that the inlets to a cylinder pair are established in opposite sides to the side wall of the forming box. Moreover the ends of the cylinder can be linked with linking channels, which go through the side wall of the forming box, and which allow the fibres to pass from the inner of a cylinder to the inner of an adjacent cylinder. Hereby can be achieved a rotation of fibres in a substantially circle-formed curve through two adjacent cylinders and the linked linking channels. This gives a good mixture and an even distribution of fibres.
In a forming box more paired cylinders or single cylinders can preferably be established, which are linked with separate supply sources of fibres. Hereby it becomes possible to form a tissue with varying fibre abilities with respect to the thickness. In a forming box three pair of cylinders will preferably be placed where the first and the terminal cylinder pair are provided with fibres, which are to be outerlayer in the formed fibrous tissue, and where the central cylinder pair is intended to form a in-between layer within the formed tissue. Such a construction is suitable for manufacturing of tissue, which is used by the manufacturing of nappies, towels and its like, where a core of hydrophilic material is formed surrounded by an outerlayer of hydrophobic material.
By placing of more paired or single cylinders within a forming box it is also possible to increase the thickness of the formed tissue, because identical fibres can be used in all cylinder pairs or single cylinders.
If the rollers are oriented substantially vertically the spikes will preferably be established with a form of substantially expanse-formed wings, which are in one plane, being approximately perpendicular on the longitudinal axis of the rollers. The wings/the spikes will preferably be established within one single layer, but two or more layers on top of each other can also be established. The wings/the spikes will preferably be established in various levels, so that an overlapping is established, where the spikes/the wings from one roller will be established in another level than the spikes/the wings from one or more adjacent rollers. Hereby is a risk for collision avoided, if the rollers are not driven synchronously. By synchronic operation of the rollers it will be possible to establish the spikes/the wings in identical planes. This can take place independently of the rollers being horizontally or vertically oriented.
In a forming box with vertically oriented rollers the wings/the spikes can be placed under an angle in relation to a plane perpendicular on the longitudinal axis of the roller. In this situation an overlapping of the described curves can also be established by the rollers alternately being provided with upwards directed spikes and downwards directed spikes, which form approximately the same inclined angle.
It is possible to place more forming boxes after each other in order to increase the thickness of the formed tissue and/or to create a tissue with different types of fibres in various layers.
It has been shown possible that the rollers can rotate around their longitudinal axis with identical or different rates. It has also been shown possible that the rollers can rotate in the same or in the opposite direction.
BRIEF DESCRIPTION OF THE DRAWINGS
The invention will in the following be explained more closely with reference to the attached drawing, where
FIG. 1 shows a schematic picture, with certain parts cut away, of a forming box according to the invention,
FIG. 2 shows schematic side picture, partly sectionally, of a forming box, as shown in FIG. 1,
FIG. 3 shows a partial side picture of details of the forming box shown in FIG. 1,
FIG. 4 shows a plane picture with certain parts cut away of the forming box shown in FIG. 1, seen from the top,
FIG. 5 shows a partial side picture for illustration of a further embodiment of a forming box according to the invention,
FIG. 6 shows a picture, partly sectionally, seen according to the line VI—VI in FIG. 7 for illustration of a further embodiment of a forming head according to the invention,
FIG. 7 shows a plane picture, seen from the top, of the forming box shown in FIG. 6,
FIG. 8 shows a side picture of the forming box shown in FIG. 6 and 7,
FIGS. 9-10 show a picture corresponding to FIGS. 7 and 8 for illustration of a further embodiment of a forming box according to the invention,
FIG. 11 shows a picture corresponding to FIG. 6 for illustration of a further embodiment of a forming box according to the invention,
FIG. 12 shows a side picture for illustration of a further embodiment of a forming box according to the invention with vertically oriented rollers,
FIG. 13 shows a picture corresponding to FIG. 12 for illustration of a further embodiment for a forming box with vertical rollers,
FIG. 14 shows a picture corresponding to FIGS. 12 and 13 for illustration of a further embodiment of a forming box with vertical rollers,
FIG. 15 shows a plane picture with certain parts removed for illustration of a forming box with vertical axles and spikes in form of expanse-formed wings, and
FIG. 16 shows a picture for illustration of plate-formed wings to be used in a forming box, as illustrated in FIGS. 12-15 and illustrated with various embodiments for holes established in the wings.
DETAILED DESCRIPTION
In the various figures identical or corresponding elements will be designed with the same reference designation and will therefore not be explained in detail in connection with each figure.
In FIG. 1 a forming box can be seen according to the invention, which generally is designated with the reference designation 1 . The forming box 1 is placed over a forming wire 2 . Upon the surface 3 of the forming wire is thus formed a fibrous tissue 4 . Beneath the forming wire 3 a vacuum box 5 is placed in a position opposite to the forming box 1 . The vacuum box 5 is linked to a vacuum source (not shown).
The forming box 1 is linked to an inlet pipe 6 . In the inlet pipes 6 an air stream is blown which contain fibres in the forming box 1 in a position on top of the spike rollers 7 . The inlet pipes 6 are linked to garnett devices in form of hammer mills or other equipment, which garnetts a fibre material, so that individual fibres are formed or individual fibres containing very few agglomerates. In the shown embodiment an inlet pipe 6 is shown in each side wall 8 of the forming box 1 . As indicated in side walls 8 , two inlet openings 9 are, however, placed in each side wall. It will optionally be possible to apply two or more inlet pipes 6 in each of the side walls, dependent of the capacity wanted in the dry forming instrument, in which the forming box 1 is part of.
The fibres which are transferred to the inlet pipes 6 can be any kind of up-splitted airborne fibres that can be chosen from among synthetic fibres or natural fibres or be a mixture of such fibres.
The forming box 1 is not provided with any bottom plate. The forming box 1 has in the shown embodiment no top plate. The forming box has end walls 10 , which are arranged shiftable with respect to heights in a direction away from and downwards against the forming wire 3 . At least the end wall 10 , which is directed against right, is shiftable with respect to heights, in that the fibrous tissue 4 is formed upon the forming wire, when this is transferred in its normal transference direction according to the arrow 11 .
The spike rollers 7 , which are placed within the forming box, can be said to make up the bottom of the forming box. In the shown embodiment there are altogether placed five spike rollers 7 in the upper layer, in that three spike rollers are placed by one side wall and two spike rollers at the opposite side. Alternatively it will be possible to mount all spike rollers from the same side. However, an alternate mounting of the spike rollers as shown allow for a bigger space between the engines 12 , which run the spike rollers. The engines 12 are arranged with the possibility for a variable revolution rate. It is thus possible to adjust the revolution rate of the engines dependent of choice of spike rollers and the product, which is to be formed. In FIG. 1 a lower layer of spike rollers is also shown, which also is placed in a substantially horizontal plane parallel to the forming wire 3 .
Each of the spike rollers 7 has an axle 13 , upon which spikes 14 in form of thread-formed elements are mounted. The spikes are in FIG. 1 shown mounted on rows axially to the axle 13 and a number of four in the circumference to the spike roller 7 . The spikes 14 are established with a size and an mutual distance, which makes it possible to allow for a passage in-between for corresponding spikes 14 on an adjacent spike roller. When the spike rollers are shifted in their planes, it is thus possible for the spikes to penetrate in-between each other, so that the spike rollers 7 can be placed with a mutual distance, where the diameter for the circle, which defines the outer end 15 of the spikes 14 , is overlapping the diameter for an adjacent spike roller 7 . The mutual shifting of the spike rollers takes place by shifting of the axle house 16 in the mounting rails 17 in each side of the forming box 1 .
In FIG. 2 engines 12 in the left side of the picture are schematically illustrated. In the right side of the picture a partial section is shown for schematically illustrating the spike rollers 7 . As it is seen the spike rollers in this embodiment is placed, so that they are in the position shifted in relation to each other in the two layers. Moreover the spike rollers are placed so that the outer ends 15 of the spikes 14 will not overlap the circle, which is described by the outer ends 15 for the spikes on an adjacent spike roller 7 .
FIG. 3 is a partial side picture of the forming box 1 shown in FIGS. 1 and 2. It is seen here that the two inlet pipes 6 have been applied on each side of the forming box. It is likewise seen that the inlet openings 9 within the forming box need not be in the same vertical plane. As illustrated in the left side the inlet openings 9 of the inlet pipes can be placed in different positions within the forming box to achieve a better distribution of the fibres, which form a fibre cloud on top of the spike rollers 7 . It is moreover to be seen that the inlet openings 9 are created in form of inclined cuttings of the pipes, which give a partly downwards directed air stream of fibres.
In FIG. 3 it is furthermore seen that the engines are placed alternately in relation to each other, and that the length of the spike rollers 7 in the two layers need not have the same length. It is also possible to vary the running direction for the spike rollers. The spike rollers can thus be driven with the same revolution direction or with different revolution directions in the same layer as well as in the different layers.
FIG. 4 shows a plane picture of the forming box seen from the top. Only some of the engines 12 are shown. It is seen here that the spike rollers 7 in the different layers are shifted in relation to each other, so that the axles 13 , as seen from the top, are distributed with substantially the same big distance over the length of the forming box 1 .
In the shown embodiments the spike rollers 7 are shown with an orientation perpendicular to the transference direction 11 of the forming wire 3 . However, it will also be possible to place the spike rollers 7 with an orientation parallel to the transference direction 11 or with an angle in relation to the transference direction 11 . However, it is preferred that the spike rollers 7 are placed as shown in the figures. In practice it has been shown that this orientation of the spike rollers gives a more even distribution of the thickness of layer over the width of the forming wire 3 .
FIG. 5 illustrates a side picture of a forming box 1 with horizontally oriented spike rollers 7 . In this forming box there is illustrated an inlet pipe 6 in the end wall 10 of the forming box in that side which is directed against the transference or movement direction 11 of the forming wire. The inlet pipe 6 can be established in the opposite end wall 10 . Opposite to the inlet opening 9 of the inlet pipe a rebound plate 18 is established. The rebound plate is mounted on adjustable seats 19 , 20 . Hereby the angle of the rebound plate can be adjusted so that an approaching cloud of fibres 21 can be directed substantially upwards according to the arrow 22 or substantially downwards according to the arrow 23 . The rebound plate can be adjusted by means of thread connections 24 , 25 . The rebound plate 18 can thus be given an angle position and can simultaneously be established in a shorter or longer distance from the inlet opening 9 .
As an alternative to the inlet pipe 6 the fibres can be introduced from the top of an upward open fibre box from the top, as indicated by the arrow 26 . In the shown embodiments the inlet openings 9 is indicated as circular openings. However, the transference opening can be an elongated cleft, and the terminal part of the transference pipe 6 can in such a situation have form of a fish tail. Hereby is achieved an introduction of a small fibre cloud 21 with a width which substantially corresponds to the width of the forming box 1 .
FIGS. 6-8 illustrate an alternative embodiment of a forming box 1 . In this embodiment substantially horizontally oriented spike rollers 7 are established along two cylinder expanses 27 , so that the spike rollers by each cylinder expanse 27 altogether form a cylinder 28 with a movable wall. In the hollow inner part 29 of the cylinder a further spike roller 30 is established. It is established relatively close to the wall of the cylinders 28 . Hereby the fibres are influenced so that they are distributed evenly over the length of the cylinders 28 . The fibres are blown inwards via inlet pipes 6 through the inlet openings 9 , which end in the inner part 29 of the cylinder . In the shown embodiment the inlet pipes 6 are established at the opposite side walls of the forming box 1 . Alternatively, both inlet pipes can be established along the same side wall.
Each of the spike rollers 7 can be rotated with the same direction of rotation within a cylinder. Alternatively, the spike rollers can be rotated in different directions of rotation. By different rotation or uniform rotation of the spike rollers it is possible to achieve an orientation of the fibres and thereby a possibility to achieve specific direction determined properties in the formed tissue.
In the shown embodiment two cylinders 28 are established. Alternatively it is, however, possible to have one single cylinder in the forming box 1 only. It is similarly illustrated that the cylinder 28 substantially covers the whole section of the forming box, as it is seen in a horizontal plane. It has appeared, however, that the cylinders 28 only need to cover a part of the sectional area of the forming box in order to achieve a uniform layer thickness in the formed tissue.
In FIGS. 9 and 10 an alternative embodiment is illustrated corresponding to FIGS. 7 and 8. In this embodiment openings are established by the ends of the cylinders 28 in the side walls 8 of the forming box, and hereby is the hollow inner part 29 between the two adjacent cylinders connected to each other by means of linking channels 31 . The linking channels 31 allow that when air blown a fibre cloud is led in a circulated movement according to the arrows 32 from the inner part of the cylinder 28 to the inner part of an adjacent cylinder 28 . This gives possibility of achieving a rather uniform distribution of fibres over the length of the cylinders 28 and thereby a uniform distribution of fibres upon the underlying forming wire.
It is to be noted that the spike rollers 7 and the cylinders 28 are established with an orientation substantially perpendicular to the transference direction 11 of the forming wire.
In FIG. 11 a picture is illustrated which substantially corresponds to FIG. 6 . In this embodiment six cylinders 28 are established. The cylinders are pairwise oriented, as explained with reference to FIGS. 6-10. The cylinders can be established with or without the linking channels 31 . The cylinders are pairwise connected with separate supply sources for fibres with different abilities. The first pair of cylinder 33 is connected to a source for supply of hydrophobic fibres, the next cylinder pair 34 is connected to a source for supply of hydrophilic fibres, and the third cylinder pair 35 is connected to a supply source for hydrophobic fibres. An integral tissue is hereby formed, which is suited for manufacturing of nappies, towels, and its like, in which a liquid absorbing core is to be established between the outer layer of hydrophobic material.
In FIGS. 12-15 is illustrated a further embodiment of a forming box 1 , in which the rollers 7 are oriented substantially vertically. Hereby the spikes 14 are rotated in planes which are substantially horizontal and principally parallel to the plane of the overside of the forming wire 3 . In FIG. 15 alternative orientations are illustrated for the inlet pipes 6 . It is, however, to be understood that the forming box 13 can be provided with this one type of inlet pipes or both types of inlet pipes, which can be used alternatively depending on the fibres which are to be introduced into the forming box 1 .
In the shown embodiment each of the vertical spike rollers 7 has between three and twelve layers of spikes. These spikes will possibly have a form and size as explained above in connection with the spikes on the horizontal spike rollers 7 .
As an alternative, the spike rollers 7 can be established with spikes of a less number of layers and possibly only one single layer. In one embodiment with fewer layers of spikes established along the length of an axle 13 the spikes will preferably be formed as plate-formed wings of the type illustrated in FIGS. 15 and 16.
In FIG. 12 the spikes are formed with a length, so that they exert a substantial overlap between the rollers 7 adjacent to the spikes. In order to assure a problemfree rotation the spikes from adjacent rollers 7 are shifted in relation to each other, so that they rotate in different planes.
In FIG. 13 a situation is illustrated where the spikes have lenghts so that the circumscribed circles approximately touch the circumscribed circles which are formed of spikes 14 from an adjacent roller 7 .
In FIG. 14 an embodiment is illustrated in which the spike rollers 7 are provided with spikes which are placed with an inclined angle in relation to a plane perpendicular to the longitudinal direction of the rollers 7 . The spikes on the adjacent rollers 7 are alternately oriented with an inclined angle upwards and downwards. Hereby it is possible for the spikes to rotate without colliding with each other. The angle of the orientation of the spikes can be between 0 and 80°, but will preferably be between 30 and 60°.
In FIGS. 15 and 16 an embodiment is illustrated where the spikes are established in form of expanse-formed wings 36 , which are mounted on an axle 13 . It is preferred that the wings 36 are placed symmetrically around the axle 13 . There can be established between two and ten wings in each layer on an axle. In the shown embodiment eight expanse-formed wings 36 are illustrated in each layer. Along an axle there can be established from one to thirteen of such wings. As it appears from FIG. 15 the wings 36 are established with such a radial length that they overlap between wings from adjacent rollers 7 . Each layer of wings will therefore be established shifted in relation to each other, for example as illustrated in FIG. 12 or 14 .
In FIG. 16 different types of holes 37 are illustrated in the wings 36 . Likewise a single wing is illustrated which is not provided with holes. The objection of the holes 37 is to facilitate the passage of air through the forming head. The holes 37 can at the same time be formed so they can be used for steering of the passage of the fibres through the forming head. This can take place by the forming of the size of the holes in combination with the rotation direction. Thus, small holes 37 and a big rotation rate for the wings 36 will make it impossible for the passage of the fibres through the holes 37 . Hereby the fibres will be able to pass only down through the forming head by influence from the suction box by passing in-between the wings 36 .
In FIGS. 15 and 16 the wings 36 are illustrated as substantially plane wings established in the plane perpendicular to the longitudinal direction of the roller 7 . However, they can be inclined to contribute to the stream of air in the forming box. They can thus be inclined to give an upwards or a downwards streaming of air. Alternatively, the wings can be established with different slope to establish turbulent upwards and downwards air streams in the section of the forming head, where the wings 36 are established. | An apparatus for uniformly distributing a disintegrated material on a fiber layer forming surface comprising a cylindrical housing having a perforated plane-surfaced bottom wall; an inlet opening for a stream of air containing suspended fibers and a stirrer having impellers rotating a short distance above the perforated bottom wall. | 3 |
CROSS REFERENCE TO RELATED APPLICATIONS
Not Applicable
STATEMENT REGARDING FEDERALLY SPONSORED RESEARCH OR DEVELOPMENT
Not Applicable
INCORPORATION-BY-REFERENCE OF MATERIAL SUBMITTED ON A COMPACT DISC
Not Applicable
BACKGROUND OF THE INVENTION
1. Field of the Invention
The present invention relates to a process and an arrangement for control of an automated gearbox. The invention is particularly applicable to mechanical servo-assisted gearboxes for heavy vehicles.
2. Description of the Related Art
Today's gearboxes of this kind are controlled by a control unit which controls gear selection so as to achieve engine operation which is appropriate in the light of experience. This has hitherto involved determining engine reference speeds at which changing up/down is in principle initiated. However, the control unit may also be designed to incorporate in the calculations the vehicle's acceleration and the accelerator pedal position in order to modify the control so that gear changing takes place at an engine speed which may be somewhat lower or somewhat higher than said reference speed. It is also possible for gear changing to be initiated in, for example, two stages instead of one. However, the known system is to be regarded as approximate and no optimisation of operation is possible on vehicles where that system is applied.
BRIEF SUMMARY OF THE INVENTION
An object of the present invention is to indicate a process and an arrangement for control of an automated gearbox, whereby control is further refined so that the operation of the vehicle can be optimised.
This object is achieved according to the invention by means of the features in the characterising part of patent claims 1 and 5 respectively.
The result is the possibility of selecting in each situation a gear combination which optimises or in practice minimises the vehicle's specific fuel consumption. By means of the invention, various possible and permissible gear alternatives can thus be compared with respect to specific fuel consumption at the operating point concerned so that the latter can be caused to lead to as economic driving as possible.
The process according to the invention involves:
the necessary drive power F being determined on the basis of the calculated running resistance at the prevailing running speed and in the prevailing operating conditions,
possible gear combinations for driving being determined,
possible gear combinations being monitored with respect to torque delivered and permissible engine speed,
the operating points for the possible and permissible gear combinations being determined,
the specific fuel consumption at said operating points being determined,
the gear combination with the lowest specific fuel consumption being selected, and
a command signal for changing to the selective gear being emitted.
The initiation of gear changes which involve one or more gears being skipped is thus not excluded.
A preferred aspect of the invention involves the process being initiated as an economy position after the control unit has, for example, detected that the running speed has for a certain period of time been approximately constant or that the accelerator pedal position has for a certain period of time been below a certain threshold value. This means that the control unit can independently initiate the process sequence, including the economy position, and achieve optimum specific fuel consumption.
Suppressing changes to a new gear combination so that the latter may only be initiated after a certain period of time eliminates excessive gear changing and the driver irritation involved in frequent gear changes.
The invention also relates to a control system suitable for implementing the process. This results in corresponding advantages. Further advantages are achieved as indicated by the following detailed description.
BRIEF DESCRIPTION OF THE SEVERAL VIEWS OF THE DRAWING(S)
The invention will now be described in more detail on the basis of an embodiment and with reference to the attached drawings, in which:
FIG. 1 shows a flow diagram of a process according to the invention, and
FIG. 2 illustrates an arrangement according to the invention in connection with the driveline for a heavy vehicle.
DETAILED DESCRIPTION OF THE INVENTION
In FIG. 1, ref. 1 represents the beginning of the sequence and ref. 2 the monitoring of running data with respect to whether the economy position can be initiated. This entails monitoring, for example, whether the running speed has for a certain period of time been approximately constant, whether the degree to which the accelerator pedal is depressed corresponds to the set-point for the prevailing operating conditions, etc. Ref. 3 represents determination of the necessary drive power on the basis of the calculated running resistance at the prevailing running speed and in the prevailing operating conditions. The running resistance value is preferably updated continuously by evaluation of incoming data concerning the engine, driveline, vehicle, roadway etc. Ref. 4 represents the determination of possible and permissible gear combinations for the prevailing driving situation and ref. 5 represents determination of the operating points for driving with these various gear combinations. Ref. 6 represents determination of the specific fuel consumption at these various operating points, which involves using information which may be derived from a so-called “mussel” diagram which shows the relationship between engine torque and engine speed with respect to the specific fuel consumption of the engine concerned. Ref. 7 represents comparison of the various operating points with respect to specific fuel consumption, resulting in selection of the gear combination corresponding to the lowest consumption. If the selected gear combination is not the gear combination engaged at the time, the length of the time which has passed since the previous gear change is monitored and if it exceeds a prescribed period of time, signals are transmitted to the relevant components to engage the selected gear combination. Ref. 8 represents the completion of the sequence.
FIG. 2 illustrates schematically an arrangement for control according to the invention, in which ref. 9 represents a control unit which advantageously incorporates devices for control according to the invention which are integrated into or connected to the normal engine control system. Ref. 16 represents a memory for registering running parameters, vehicle weight, running resistance etc. which have to be taken into account in connection with the present invention.
In the driveline, the engine is denoted by 10 , the clutch by 11 and the here triple gearbox by 12 , 13 and 14 , which may represent a division into split, main and range gearboxes. An output speed sensor is denoted by 15 and the final gear by 17 .
The control unit 9 is designed to:
determine the necessary drive power F on the basis of the calculated running resistance at the prevailing running speed and in the prevailing operating conditions,
determine possible gear combinations for driving,
monitor possible gear combinations with respect to torque delivered and permissible engine speed,
determine the operating points for the possible and permissible gear combinations,
determine the specific fuel consumption for said operating points,
select the gear combination with the lowest specific fuel consumption, and
emit a command signal for changing to the gear selected.
The invention may be varied within the scope of the patent claims set out below. Thus the input data for the calculations may to some extent be varied but should preferably cover running speed, accelerator pedal position, vehicle weight, road gradient, fuel consumption information, gearchange conditions in the gearbox and, where applicable, in the various constituent gearboxes forming part of the gearbox, engine speed and torque curve. Gearchange times may also be incorporated in the calculations, in which case short changing times to certain gear combinations may result in their being preferred.
The process according to the invention, including an economy position, is thus relevant when the vehicle speed is relatively constant, the accelerator pedal is preferably not more than 50% depressed and the engine torque set-value is below a certain specified threshold level. Studies of the driving of heavy vehicles have shown that the economy mode is applicable during as much as 70-80% of running time, which indicates that there is substantial potential for saving which can be utilised by means of the invention, even if the reduction in consumption achieved by means of the invention is not more than a few percent.
EXAMPLE
In one example studied, a vehicle with a total weight of 60 tonnes was driven at a speed of 50 km/h. The gearbox used was a triple gearbox incorporating range, main and split gearboxes, designated SCANIA GRS900. The engine was a SCANIA DSC11413 and the vehicle was driven on a smooth horizontal stretch of road, with the results shown in the following table:
Engine torque required
Engine speed
Specific fuel
Gear
(Nm)
(rpm)
consumption (g/kWh)
8
290
2070
260
9
380
1620
240
10
460
1320
230
11
580
1040
210
In the driving situation described above, gear 11 is selected for optimum fuel economy. If the vehicle had for example been driven in gear 10 , the specific fuel consumption would have been about 9% higher. With previously known control systems, the vehicle might very well have been driven in that gear, resulting, in this specific case, in substantially higher fuel consumption for the run. | A process and an arrangement for the control of an automated gearbox. Control is conducted by determining possible gear combinations for driving, determining the operating points for the gear combinations, determining the specific fuel consumption at the operating points, selecting the gear combination with the lowest specific fuel consumption and emitting a command signal for changing to the selected gear combination. | 5 |
BACKGROUND OF THE INVENTION
This invention pertains generally to locking devices and more particularly to locking devices having a flexible, elongated member with a locking device to interconnect the ends thereof and form a closed loop. Devices of this type are commonly used to immobilize portable items or equipment such as typewriters, televisions, bicycles or the like, or to interconnect moveable members such as gates, doors or other components where it is desired to selectively immobilize or fix motion therebetween. The annular locking device of this invention is also applicable to uses where throughlock connections must be made such, for example, where it is desired to selectively lock electrical or fluid conductors at interconnecting points to one another or to a panal or other device.
A problem with the prior art devices to which this invention pertains, is that the elongated member can be readily severed with easily available tools. Armored cable and hardened chain make such breaking more difficult, however, bolt cutters or hacksaws will defeat such protection. Electrical circuits have been devised to provide an alarm in conjunction with these types of locks, however, this solution requires bulky and relatively complex attachments and the need for electrical power.
SUMMARY OF THE INVENTION
This invention provides an anti theft locking device having a passive, thief repelling and/or identifying fluid ejector which is actuated upon attempt to break the locking device.
The invention also provides a tubular lock which is suitable for interconnecting and selectively immobilizing elongated members such as fluid, electric or heat conducting cables to one another or to other devices.
In a preferred embodiment, the invention provides an anti theft locking system including a flexible tubular container charged with a pressurized propellant carrying a dye and/or irritant and interconnected at the ends thereof by a tubular locking device through which the container extends.
The objects and other advantages of the invention will become better understood to those skilled in the art by reference to the following detailed description when viewed in light of the accompanying drawings wherein like numerals throughout the figures thereof are indicative of like components and wherein:
BRIEF DESCRIPTION OF THE DRAWINGS
FIG. 1 is a view, partly in section, of an embodiment in accordance with the invention;
FIG. 2 is a sectional view of FIG. 1 taken along the line 2--2 thereof;
FIG. 3 is a fragmentary view, in section, of a portion of the structure of FIG. 1;
FIGS. 4a and 4b are ends views of the structure as shown in FIG. 3 taken from the lines 4a--4a and 4b--4b thereof;
FIGS. 5a 5b and 5c are detailed sectional views of elements of the structure shown in FIG. 3; and
FIG. 6 is a fragmentary view, in section, of a variation in accordance with the invention.
DESCRIPTION OF PREFERRED EMBODIMENT
In FIG. 1, the locking system 10 comprises an elongated flexible tubular member, shown generally at 12, and a locking device, generally indicated by 14, providing locking interconnection of the ends of the member 12 to form a closed loop as shown. The locking device is composed of a male lock component 16a associated with one end of the member 12 and a female lock component 16b associated with the other end of the member. As can be best seen in the sectional portion of FIG. 1 and by reference to FIG. 2, the member 12 includes an outer tubular sheath 18, formed of suitable flexible, nonstreatch, wear and damage resistant material such, for example, as helically wound "armord cable" type steel, braided wire, cord plastic or the like. The main function of the sheath is to protect its contents against mechanical damage, wear and/or elongation as will be described in greater detail below.
As can be best seen in FIG. 3, the sheath 18 terminates at each end in components 16a and 16b of the locking device 14. Termination may be accomplished by any suitable means so long as the interior diameter of the tubular passage formed by the sheath 18 is not reduced thereby. As shown, connection is effected in the embodiment illustrated by flaring the ends of the sheath 18 and fixing them to the components within conical portions 20a and 20b with wedge bushings 22a and 22b in a manner well known in the art.
Best seen in FIGS. 3, 4b and 5a through 5c the component 16a of the locking device 14 comprises a series of concentrically disposed tubular tumblers 24a, 24b, and 24c arrainged around a tubular projection 26 extending from the conical portion 20a. Each tumbler comprises, respectively, a barrel portion 28a, 28b, and 28c from which a key 30a, 30b and 30c are of decreasing diameter and of increasing length in that order so that they may be nested in one another with their respective keys 30a, 30b and 30c longitudinally spaced as shown in the figures. The radial heights of the keys 30a, 30b and 30c increase in that order so that the relative height of the keys, when assembled, is substantially equal. A turning ring 32a, 32b and 32c is fixed to the barrels 28a, 28b and 28c at the ends thereof opposite the keys. A snap ring 34a, 34b and 34c, having numbers on the periphery thereof, is disposed over the respective turning rings 32a, 32b and 32c. As best seen in FIG. 1, the rings are numbered from 0 to 9 to provide an external indication of the rotational position of the respective keys 30a, 30b and 30c. As is best seen in FIG. 4b, the interior surface of the snap ring 34a is provided with a series of radial projections 36 while the exterior surface of the turning ring 32a is furnished with a corresponding series of serrations 38 which receive the projections 36. By this means the snap rings can removably engage the turning rings to provide mechanical interconnection and, yet, removable for reindexing to change the lock combination by changing the relative position of the snap ring number and the key.
The female lock component 16b comprises a cylindrical housing 40 extending from the conical portion 20b having an internal bore 42 of diameter sufficient to just accept the largest diameter barrel portion 28a of the male lock component 16a. The bore 42 is provided with a longitudinally extending keyway 44 which is sized to accept the keys 30a, 30b and 30c when they are aligned as shown in FIG. 3. A series of annular grooves 46a, 46b and 46c are formed in the bore 42 to intersect the keyway 44 at points of identical spacing to the assembled spacing between the keys 30a, 30b and 30c such that, upon connection of the lock components 16a and 16b as in FIG. 1 and rotation of one or more of the keys 30a, 30b or 30c from the aligned condition shown in FIG. 3, the keys will enter into their respective annular grooves 46a, 46b or 46c thereby locking the ends of the member 12 together.
The structure thus far described not only provides a relatively continuous structure for locking objects but it also provides a tubular locking device having a continuous, uninterrupted bore through the lock for important purposes to be described below.
Referring again to FIGS. 1 and 2, a tubular, flexible cartidge 48 having closed ends 50a and 50b is disposed in the sheath 18. The cartridge provides a pressure tight container and is charged with a pressurized propellant such as a halogenated hydrocarbon marketed under the Dupont trademark "FREON" or the like to provide a pressure discharge upon rupture of the cartridge 48. A dye and/or irritant is mixed with the propellant to be discharged therewith upon rupture of the cartridge. Suitable irritants would be noxious but relativey harmless substances such, for example, as pepper or the like. The dyes wuld be indelible or insoluable in water and of the brighter hues to mark and identify individuals attempting to break the locking device. The cartridge 48 is preferably made of a synthetic material such as butyl rubber or the like, however, any flexible material compatible with the described environment can be used for this purpose.
The cartridge 48 is formed in a length suitable to place the ends 50a and 50b in abutment when the device is connected as seen in FIG. 1. In this way, an attempt to sever the member 12 at any point other than the location of the abutting ends of the cartridge 48 will result in rupture of the cartridge with discharge of its contents. An important feature of this invention is that the above described structure provides the following capabilities. Firstly, the location of the abutting point within the sheath 18 can be varied from device to device so that this point is never predictable to anyone other than the lock user. This is accomplished by varying the relative positions of the cartridge and the sheath so that the amount of cartridge projecitng from either the male lock component 16a or the female component 16b varies from lock to lock. This variation is preferably accomplished during fabrication of the device and, once established, is maintained fixed by attaching the cartridge 48 to the sheath 18 by means of adhesive or the like. Some latitude for relative movement or replacement of the cartidge could be provided if so desired. The completely open, uninterrupted bore through the sheath 18 and the locking device 14 provides to ability to move the abutting point between the ends of the cartridge 48 without restriction. This feature also permits and intimate relationship between the ends of the cartridge which enables the variation illustrated in FIG. 6. In that figure, components corresponding to like components of the preceeding figures are indicated by like numerals of the next higher order. In the variation shown, the ends of the cartridge 148 are formed with complementary shapes (i.e., 105b beng concave and 150a convex) so that they are "nested" in one another as shown. In this manner, a straight line cut through the member 112, even though carefully placed at the point of abutment, must rupture the cartridge 148. Obviously other complimentary forms of the ends of the cartridge will accomplish the above objectives.
What has been described above is intended to be exemplary of a teaching in accordance with the invention to aid those skilled in the art in the practice thereof. | An anti theft locking system including a tubular container charged with an irritant and dye with a locking device to interconnect the ends of the container in a closed loop. | 4 |
FIELD OF THE INVENTION
The present invention relates generally to fuel control systems and, more particularly, to a system for rationalizing the alcohol content of the fuel of a flexible fueled vehicle.
BACKGROUND OF THE INVENTION
Alternative fuel vehicles are becoming commonplace in response to environmental and energy conservation concerns. Alcohol in the form of ethanol or methanol is combined in various percentages with gasoline to produce one type of alternative fuel. The vehicles capable of operating on more than one blend of gasoline and alcohol are referred to as flexible fuel vehicles. These vehicles may have some capability to adjust various engine operating parameters to compensate for the effects of one alcohol fuel blend over another including the possible use of gasoline unblended with alcohol.
This includes adjustment to the air to fuel mixture in order to maximize engine performance and to fully burn the fuel in use. The ideal air to fuel ratio in an internal combustion engine is typically considered to be the ratio of mass flow rate of air to mass flow rate of fuel inducted by an internal combustion engine to achieve conversion of the fuel into completely oxidized products. The chemically correct ratio corresponding to complete oxidation of the products is called stoichiometric. If the air/fuel ratio is less than stoichiometric, an engine is said to be operating rich, i.e., too much fuel is being burned in proportion to the amount of air to achieve perfect combustion. Likewise, if the air/fuel ratio is greater than stoichiometric, an engine is said to be operating lean, i.e., too much air is being burned in proportion to the amount of fuel to achieve perfect combustion. Since alcohol fuels require a lower air/fuel ratio than pure gasoline at stoichiometric, the engine must be compensated for in the rich direction. The amount of compensation increases as the percentage of alcohol in the fuel increases. For example, an engine operating on E85 (a blend of 85% ethanol and 15% gasoline) requires approximately 1.4 times the amount of fuel relative to gasoline at stoichiometry due to a lower energy content of the ethanol.
Various prior art methods and systems are already disclosed for determining the amount or percentage of alcohol in the fuel of a flexible fuel vehicle. Some of these systems utilize a composition sensor to measure the composition of the fuel used. A problem with these composition sensor based systems is the advent of sensor failure or miscalculation. This could result in the engine control system receiving faulty data upon which the engine is operated.
Other systems “learn” the alcohol content of the fuel through an oxygen sensor in the exhaust system that measures the oxidation of combustion byproducts in the exhaust. A potential problem with these “learn” based systems is the effect of a malfunction of a component of the system that effects the combustion byproducts or even a malfunction of the oxygen sensor. For example, a clogged fuel filter or injector drift could effect the learned determination of the alcohol content by causing a faulty fuel system and resulting in lean combustion. A system could under these and other circumstances learn into the alcohol realm and effect the engine control system.
Therefore, there is a need for a system that will rationalize the alcohol content without reliance on a fuel composition sensor. Further, a system is needed that will rationalize the alcohol content as a backup to any sensor or learned result.
SUMMARY OF THE INVENTION
It is therefore an object of the invention, a rationality system, to rationalize (i.e. check for accuracy) the alcohol content of the fuel in a flexible fueled vehicle. It is a further object to provide a backup to a learned (i.e. oxygen sensor) or fuel composition sensor based system in determining the possible alcohol content of the fuel. A further object of the invention is to allow activation of warning systems and/or other action if the system detects fault in the determination of the alcohol concentration in the fuel.
In operation the invention is activated by a triggering event such as an addition of fuel to the fuel tank. The rationality system then calculates the possible concentrations of alcohol in the fuel based on the possible fuels added. Next, the rationality system compares the alcohol content as determined by a learned based system or a sensor based system to the possible concentrations of alcohol. If the determined alcohol content is too far from the possible concentrations of alcohol then a fail counter is incremented to show a failure to properly determine the fuel alcohol content. If the fail counter reaches a predetermined level then action is taken to warn the vehicle operator of the fault. Diagnostic systems may also be enabled or disabled depending on whether the alcohol content of the fuel is within the alcohol realm.
Further areas of applicability of the present invention will become apparent from the detailed description provided hereinafter. It should be understood that the detailed description and specific examples, while indicating the preferred embodiment of the invention, are intended for purposes of illustration only and are not intended to limit the scope of the invention.
BRIEF DESCRIPTION OF THE DRAWINGS
The present invention will become more fully understood from the detailed description and the accompanying drawings, wherein:
FIG. 1 is a flowchart of a preferred embodiment of the rationalization system;
FIG. 1 a is a continuing flowchart of the rationalization system; and,
FIG. 1 b is a continuing flowchart of the rationalization system.
DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS
The following description of the preferred embodiment(s) is merely exemplary in nature and is in no way intended to limit the invention, its application, or uses. The diagrams and discussion refer generally to ethanol and specifically to an ethanol in the form of E85 (i.e. 85% ethanol and 15% gasoline) as a type of alcohol mixed with gasoline to produce an alternative fuel. This is not intended as a limitation however, as it should be apparent to one skilled in the art that the rationalization system would equally apply to other alternative fuels including other alcohol based fuel blends such as methanol based fuel blends.
The rationalization system process is initiated in step 10 . In step 12 the rationalization system checks for the addition of fuel. This may include comparing a detected change in fuel volume to a minimum fixed amount or a percentage or both in order to limit the system to activation based on a certain minimal change in fuel volume. As an alternative the system can be activated based on a simple change in fuel volume.
If the system determines that insufficient fuel has been added at step 12 , the method advances to step 14 and ends pending a subsequent execution thereof. For example, the method could be run at each start-to-run transition event. Still referring to step 12 , if the system determines that fuel has been added, the method continues to step 16 .
In step 16 the system compares an ethanol realm counter with a calibrated value. The ethanol realm counter counts the number of times that the system determines that the fuel in the vehicle contains a specified minimum percentage of ethanol that qualifies as operating in the ethanol realm. For example, the ethanol realm can be set at a minimum value of 30% meaning the fuel in the vehicle must be at least 30% ethanol to be considered in the ethanol realm. The calibrated value is also a specified number corresponding to a minimum number of times that the system must determine the fuel to contain 30% ethanol in order to disable certain functions until an ethanol “learn” is completed. If the ethanol realm counter is greater than the calibrated value at step 16 then it is considered that the fuel system is known to use ethanol. In this event the method advances to step 18 where the system disables onboard diagnostics (OBD) until the fuel system “learns” the amount of alcohol in the system. An example of some of the OBD diagnostics that may be disabled include the fuel system monitor, oxygen sensor monitor, and misfire monitor.
An ethanol “learn” may be based on an oxygen sensor in the exhaust system of the vehicle. The ethanol learn based on an oxygen sensor may generally be characterized as measuring the level of oxygen in the combustion byproducts and calculating a percentage concentration of ethanol based on this measure.
If the ethanol realm counter is less than the calibrated value at step 16 then the method moves to step 24 where the final learned ethanol percent is retrieved from memory. The final learned percent is the learned ethanol percent from the last time that it was determined. Next, in step 26 , the possible concentrations of ethanol are calculated. These calculations are as follows:
A first percent possibility, assuming that a first percent of ethanol is a lower percent of ethanol, such as less than 50 percent, or even 0 percent was added, equals the change in fuel volume multiplied by lower percent of ethanol (as an example 15%) plus the pre-fill fuel volume multiplied by the final learned ethanol percent then divided by the post-fill fuel volume. If the lower percent of ethanol is 0 percent then the first percent possibility equals the pre-fill fuel volume multiplied by the final learned ethanol percent divided by the post-fill fuel volume.
A second percent possibility, assuming that a second percent of ethanol is a higher percent of ethanol, such as greater than 50 percent, or even 85 percent, was added equals the change in fuel volume multiplied by 85% (as an example of E85) plus the pre-fill fuel volume multiplied by the final learned ethanol percent then divided by the post-fill fuel volume.
In these calculations an E0-possiblity, as a first percent possiblity, represents the possibility of zero percent ethanol fuel was added to the tank. The E0-possibility is calculated by taking the pre-fill fuel volume which is the volume of fuel prior to the most recent addition of fuel and multiplying it with the ethanol percent that is the final learned ethanol percent. This calculation is then divided by the total fuel volume.
In the above calculations an E85-possiblity represents the possibility of 85 percent ethanol fuel was added to the tank. For the E85-possibility calculation, the delta fuel volume is the change in volume between the pre-fill fuel volume and the volume following the addition of fuel. The delta fuel volume is multiplied by 85 percent representing the percentage of alcohol in E85 fuel. This calculation is then added to the calculation of pre-fill fuel volume multiplied by the ethanol percent. The pre-fill fuel volume is the volume of fuel prior to the most recent addition of fuel. The ethanol percent is again, the final learned ethanol percent. This entire calculation is then divided by the current fuel volume in order to determine the E85-possibility.
Next, in step 28 the ethanol content rationality thresholds are calculated. The thresholds are calculated as follows:
A first ethanol rationality pass threshold, for instance when less than 50% ethanol was added to the tank, such as 0 percent ethanol, equals the final learned ethanol percent minus the result of the final learned ethanol percent minus the first ethanol percent possibility multiplied by the ethanol content rationality pass threshold fraction.
A second ethanol rationality pass threshold, for instance when more than 50% ethanol was added to the tank, such as 85 percent ethanol, equals the final learned ethanol percent plus the result of the second percent possibility minus the final learned ethanol percent multiplied by the ethanol content rationality pass threshold fraction.
For calculation of an E0-rationality-pass-threshold, as a first ethanol rationality pass threshold, the starting ethanol percent is again the final learned ethanol percent. The E0-possibility is the percent possibility calculation as determined in step 26 . The ethanol content rationality pass threshold fraction is a fixed value that is used in the calculation to factor in a degree of freedom from the base calculation.
For calculation of an E85-rationality-pass-threshold, as a second ethanol rationality pass threshold, the starting ethanol percent is the final learned ethanol percent. The E85-possibility is the percent possibility calculation as determined in step 26 . The ethanol content rationality pass threshold fraction is preferably the same fixed value as in the preceding equation.
Moving to step 30 a new learned ethanol percent is determined. This may be performed by an oxygen sensor in the exhaust system of the vehicle. The oxygen sensor allows for calculating a percent of ethanol by sensing a rich or lean level of combustion. After this step the logic flows through connector 32 to FIG. 1 a.
Referring now to FIG. 1 a , in decision block 34 the new learned ethanol percent is compared to the ethanol realm threshold. The ethanol realm threshold is again the fixed percentage of ethanol (e.g. 30%) determined to represent the minimal percentage of ethanol necessary to consider that the fuel system is within an ethanol realm. If the learned ethanol percent in step 34 exceeds the ethanol realm threshold, then in step 36 an ethanol realm counter is incremented. The ethanol realm counter keeps track of each time that the fuel system is found in the ethanol realm. Next, in step 38 the new learned ethanol percent is stored as the final learned ethanol percent for future calculations.
In decision block 40 , the system checks for a fuel level fault or if the change in fuel volume is less than the minimum volume required to perform the ethanol content rationality determination. In the event of a fuel level fault or a change in fuel volume less than the minimum volume required, then in step 42 the system is stopped. Otherwise, the system logic proceeds in decision block 44 where the learned ethanol percent is compared to the ethanol rationality pass thresholds calculated in step 28 . The check of decision block 40 differs from that of decision block 12 by setting a higher minimum volume requirement or other more restrictive requirements than in decision block 12 . For example, the minimum change in fuel volume may be 40% in step 40 while the minimum change in fuel volume may be 15% in step 12 .
In step 44 a check is performed to determine if the new learned ethanol percent is within one of the first or second ethanol rationality pass thresholds or if the new learned ethanol percent is less than the ethanol realm threshold. The ethanol rationality pass thresholds were calculated in step 28 . The first part of step 44 involves comparing the new learned ethanol percent to the first and second ethanol rationality pass thresholds from step 28 . If the new learned ethanol percent is less than the first ethanol rationality pass threshold or greater than the second ethanol rationality pass threshold then the new learned ethanol percent is within one of the ethanol rationality thresholds. Otherwise, the new learned ethanol percent is outside of the ethanol rationality pass thresholds and the new learned ethanol percent has failed the ethanol rationality.
Still referring to step 44 the ethanol realm threshold is the same as identified in step 34 . If the new learned ethanol percent is within the ethanol rationality pass thresholds or the new learned ethanol percent is less than the ethanol realm threshold (e.g. 30%) then the ethanol content fail counter in step 48 is decremented. Alternatively, the ethanol content fail counter is incremented in step 46 . Next, in connector block 50 the logic of the system continues to FIG. 1 b.
Referring now to FIG. 1 b , in decision block 52 the ethanol content fail counter is compared to zero. If the ethanol content fail counter is greater than zero, and if the ethanol content fail counter plus the ethanol realm clearing threshold are greater than the ethanol realm counter then the system logic moves to decision block 56 where the ethanol realm counter is set to zero. In step 52 the ethanol realm clearing threshold is a fixed value for example 3 representing a threshold number of times the ethanol realm counter is above the ethanol content fail counter before the ethanol realm counter is cleared to zero. Step 52 is intended to protect the gasoline only user by not disabling OBD monitoring when the logic of the system reaches step 16 during the next cycle of the rationalization system.
Next, in decision block 58 the ethanol content fail counter is compared to the fail limit. The fail limit is a fixed value representing the number of times of failure before determining that action should be taken. If the ethanol content fail counter is greater than or equal to the fail limit, then in step 60 the malfunction indicator lamp is set. If the ethanol content fail counter is less than the fail limit at decision block 58 , or after setting the process of block 60 , the method continues to terminator 62 . The process for the system stops in step 62 .
The description of the invention is merely exemplary in nature and, thus, variations that do not depart from the gist of the invention are intended to be within the scope of the invention. Such variations are not to be regarded as a departure from the spirit and scope of the invention. | A method for checking the accuracy of an oxygen sensor based determination of the alcohol content of the fuel of a flexible fueled vehicle. Following the addition of fuel to the flexible fueled vehicle two alcohol concentration possibilities are calculated. The two alcohol concentration possibilities are then used to calculate thresholds for the determining if the oxygen sensor based determination falls within the thresholds. If the oxygen sensor based determination does not fall within the thresholds then action is taken to counteract an inaccurate determination of alcohol concentration. | 8 |
INCORPORATION BY REFERENCE
[0001] The present application claims priority from Japanese application JP2004-372619 filed on Dec. 24, 2004, the content of which is hereby incorporated by reference into this application.
BACKGROUND OF THE INVENTION
[0002] The present invention relates to a luminescence detection apparatus that detects luminescence released by biological and chemical reactions between a reagent solution and a reaction solution.
[0003] Heretofore, a broad spectrum of fluorescent DNA sequencers, for example, by gel electrophoresis and capillary array electrophoresis have widely been used as DNA sequencers automatically determining DNA base sequences. DNA sequencing using these DNA sequencers is a method based on the dideoxy chain termination (Sanger method) by which prepared DNA fragments are subjected to electrophoresis (see e.g., T. A. Brown, Genomes Medical Science International published on May 26, 2000, p. 70-78).
[0004] Especially capillary array electrophoresis can determine a long base sequence at a time and as such, played a greatly active role in the human genome project whose completion was announced by the human genome sequencing consortium in April 2003.
[0005] Before and after the completion of the human genome project, DNA sequencers in demand were getting divided into large-scale sequencing-specific apparatuses for the analysis of DNA in large quantities with high throughput and into apparatuses compact in size and conveniently available at low cost.
[0006] For example, gene diagnosis and polymorphism analysis, which conduct comparison with known genomic information, do not have to newly determine the whole DNA sequence, and the determination of a DNA sequence in a short region of interest suffices for most situations. In this case, preferred DNA sequencers are apparatuses compact in size and conveniently available at low cost. However, DNA sequencers by gel electrophoresis and capillary array electrophoresis in the prior arts are not necessarily proper because they need to comprise, for example, a high voltage power source.
[0007] Therefore, DNA base sequencing called Pyrosequencing that uses stepwise chemical reactions combining polymerase-catalyzed extension of a complementary DNA strand with bioluminescence detection (see e.g., Analytical Biochemistry 244, 367-373 (1997)) receives attention as a method that satisfies the above-described requirements.
[0008] Hereinafter, the basic principle of Pyrosequencing will be illustrated.
[0009] Pyrosequencing determines a base sequence by luminescence detection conducted simultaneously with polymerase-catalyzed DNA complementary strand extension reaction after four different dNTPs are added successively but one at a time to template DNA.
[0010] In Pyrosequencing, the dNTP is incorporated into the template DNA to generate pyrophosphate, if DNA complementary strand extension reaction occurs. The generated pyrophosphate is converted to ATP by an enzyme such as ATP sulfurylase. The generated ATP causes a luciferase/luciferin reaction system to light up. This bioluminescence is optically detected. On this occasion, by monitoring a luminescence for determining which type of DNTP is added to cause a luminescence, the presence or absence of DNA complementary strand extension reaction can be detected to determine bases one by one in the template DNA base sequence. In the case of consecutive bases, the number of the same consecutive base species can be determined by monitoring luminescent intensity, because the amount of pyrophosphate generated during DNA complementary strand extension reaction is proportional to the number of bases incorporated, that is, proportional to the amount of luminescences. In this case, the added dNTPs that remain present in the reaction solution hinder the determination of the sequence. In recent years, a method for enzymatically degrading an excess of dNTP by allowing a dNTP-degrading enzyme (apyrase) to coexist with the reaction solution (see WO 98/28440) has been developed, and automated apparatuses for the method have been achieved.
[0011] Thus, Pyrosequencing does not require large components such as a high voltage power source, a laser light source, and a space for DNA separation used in conventional gel electrophoresis and capillary array electrophoresis.
[0012] As described above, Pyrosequencing that exploits bioluminescences receives attention as a method capable of conveniently determining DNA base sequences at low cost with an apparatus compact in size, as compared to gel electrophoresis and capillary array electrophoresis.
[0013] However, pyrosequencers do not have a long history. Pyrosequencers currently commercially available are large apparatuses that employ a 96-well titer plate as a reaction cell and use a CCD camera in an optical system (see National Publication of International Patent Application No. 2002-518671), and are therefore susceptible to improvement.
[0014] The pyrosequencers still have room for improvement in point of convenience and cost efficiency.
[0015] At least four different reagent solutions (containing DATP, dCTP, dGTP, or dTTP) are injected into reaction cells. In general, the reagent solutions are successively injected using a set of four reagent tubes and four nozzles respectively communicating with the reagent tubes. For example, when 96 reaction cells (i.e., titer plate) were used, 96 sets each composed of four reagent tubes and four nozzles respectively communicating with the reagent tubes, that is, 384 reagent tubes and 384 nozzles respectively communicating with the reagent tubes, required preparing. In this case, reagent tubes and nozzles were so many that problems came up, such as a rise in manufacturing costs and complicated maintenance for preventing clogging or the like.
[0016] The amount of the reagent solution added for determining a DNA base sequence, that is, a DNTP solution, is preferably not more than one hundredth the amount of a reaction solution. This is because the addition of the DNTP solution in large amounts changes the amount of the reaction solution and thereby causes reduction in enzyme concentration and in reaction rate. Therefore, the addition of the DNTP solution involves stirring the reaction solution. This becomes particularly important in miniaturizing the apparatus or in injecting the reagent solution in trace amounts. For example, when 20 μL of the reaction solution is used, the amount of the DNTP solution is 0.2 μL or less, and means for efficiently stirring a trace amount of the reagent solution as well as convenient means compact in size for accurately injecting a trace amount of the reaction solution is required.
[0017] The present invention solves the above-described problems, and an object of the present invention is to provide a luminescence detection apparatus compact in size which is capable of conveniently determining DNA base sequences at low cost.
SUMMARY OF THE INVENTION
[0018] For attaining the above-described object, the present invention provides a luminescence detection apparatus comprising: a plurality of reaction cells each having a substantially transparent bottom portion; a solution-dispensing portion equipped with capillaries positioned above the above-described reaction cells and put into a one-to-one correspondence with the above-described reaction cells; and a light-detecting portion having a plurality of light-sensing elements put into a one-to-one correspondence with the above-described reaction cells and arranged in proximity to the bottom surfaces of the above-described reaction cells, which uses the a plurality of light-sensing elements of the above-described light-detecting portion to individually detect luminescences generated in the above-described reaction cells by injecting reagent solutions from the above-described solution-dispensing portion to the above-described reaction cells.
[0019] Such construction allows the luminescence detection apparatus to discharge reagent solutions from all of the capillaries provided in the solution-dispensing portion and thereby to achieve collective and simultaneous injection in simple apparatus construction without the use of a complicated driving portion. In addition, the luminescence detection apparatus can be constructed to have reagent tubes and capillaries smaller in number than those of prior arts. Since reagents solutions are discharged from all of the capillaries at predetermined periods, the apparatus does not have to be designed in consideration of the drying of discharge nozzles of the capillaries, and so on.
[0020] Furthermore, the light-detecting portion secures a large solid angle that receives light and can therefore detect luminescences with high light-gathering efficiency without the use of a complicated optical system. Therefore, the luminescence detection apparatus can achieve a high-sensitivity light-detecting portion.
[0021] According to the present invention, a luminescence detection apparatus compact in size which is capable of conveniently determining DNA base sequences at low cost can be provided.
[0022] Other objects, features and advantages of the invention will become apparent from the following description of the embodiments of the invention taken in conjunction with the accompanying drawings.
BRIEF DESCRIPTION OF DRAWINGS
[0023] FIG. 1 is a perspective view showing the appearance of a luminescence detection apparatus in an embodiment of the present invention;
[0024] FIG. 2 is a perspective view showing the substantial part of the luminescence detection apparatus shown in FIG. 1 when a body cover is removed from the luminescence detection apparatus;
[0025] FIG. 3 is a view illustrating corresponding arrangements between the components of a solution-dispensing portion and reaction cells in an embodiment of the present invention;
[0026] FIG. 4 is a vertical sectional view showing the substantial part of a luminescence detection apparatus in an embodiment of the present invention;
[0027] FIG. 5 is an enlarged sectional view of the substantial part for illustrating the attachment mode of a transparent conductive layer, where FIG. 5 ( a ) illustrates the attachment mode of a transparent conductive layer 26 a of the present embodiment and FIG. 5 ( b ) illustrates the application of the attachment mode of a typical transparent conductive layer;
[0028] FIG. 6 is a schematic view illustrating the state of stirring with a vibration motor in the attachment mode of the transparent conductive layer shown in FIG. 5 , where FIG. 6 ( a ) illustrates construction during stirring when the attachment mode of a transparent conductive layer of the present embodiment is applied and FIG. 6 ( b ) illustrates construction during stirring when the attachment mode of a typical transparent conductive layer is applied;
[0029] FIGS. 7 ( a ), 7 ( b ), 7 ( c ), and 7 ( d ) are results of detecting noises either during non-stirring or during stirring in the attachment modes of a transparent conductive layer of the present embodiment and a typical transparent conductive layer;
[0030] FIG. 8 is measurement data showing correlation between the frequency of a vibration motor and reaction efficiency;
[0031] FIG. 9 is a view illustrating corresponding arrangements between the components of a solution-dispensing portion and reaction cells in Modification Example 1 to the number of reaction cells;
[0032] FIG. 10 is a view illustrating corresponding arrangements between the components of a solution-dispensing portion and reaction cells in Modification Example 2 to the number of reaction cells;
[0033] FIG. 11 is a view illustrating corresponding arrangements between the components of a solution-dispensing portion and reaction cells in Modification Example 3 to the number of reaction cells;
[0034] FIG. 12 is a view illustrating the order of dNTP solutions to be injected into each reaction cell 6 in the present Example; and
[0035] FIGS. 13 ( a )- 13 ( d ) show detection data of a luminescence in each of the reaction cells in the present Example.
DESCRIPTION OF REFERENCE NUMERALS
[0000]
1 : luminescence detection apparatus
2 : reagent tube holder (disk)
3 : rotating shaft
4 : pressure pipe (passage)
5 : rotating seal (passage)
6 : reaction cell
7 : reaction cell holder (holding plate)
8 : tray (holding plate)
9 : body cover
10 : eject button
11 : door
12 : light-shielding plate
13 : base
14 : shield
15 : shield case
16 : stand
17 : reagent tube (reagent container)
18 : capillary
19 : solution-dispensing portion
20 : gas passage (passage)
20 a : gas inlet
20 b : upper end
21 : convex portion
22 : rotating motor
23 : through-hole
24 : photosensor (light-sensing element)
25 : amplifier
26 : quartz glass
26 a : transparent conductive layer
27 : guide
28 : rotating-shaft bearing
29 : light-detecting portion
DETAILED DESCRIPTION OF THE INVENTION
[0068] Hereinafter, a best mode for carrying out a luminescence detection apparatus of the present invention (hereinafter, referred to as an “embodiment”) will be described in detail, appropriately referring to the drawings. In the descriptions below, the same reference numerals will be used to designate the same components, so that the redundant description will be omitted.
[0069] Now referring to FIG. 1 and FIG. 2 , the luminescence detection apparatus according to the present embodiment will be outlined.
[0070] FIG. 1 is a perspective view showing the appearance of a luminescence detection apparatus 1 , and FIG. 2 is a perspective view showing the substantial part of the luminescence detection apparatus 1 shown in FIG. 1 , from which a body cover 9 is removed.
[0071] As shown in FIG. 1 , a reagent tube holder 2 and a rotating shaft 3 removably mounting the reagent tube holder 2 thereon are provided in the upper middle portion of the luminescence detection apparatus 1 . Reagent tubes 17 containing reagent solutions are inserted in the under surface of the reagent tube holder 2 that has been removed from the rotating shaft 3 (see FIG. 3 ). A pressure pipe 4 is connected via a rotating seal 5 to the upper portion of the reagent tube holder 2 .
[0072] Reaction cells 6 are the fields of reaction between reagent solutions discharged from capillaries 18 (see FIG. 3 ) communicating with the reagent tubes 17 and reaction solutions dispensed in advance in the reaction cells 6 . In the present embodiment, the reaction cells 6 are, for example, the fields of DNA complementary strand extension reaction while being the fields of luciferin/luciferase luminescent reaction.
[0073] A “sample” in the present embodiment is a substance to be analyzed and is not limited to a biological sample. If the sample is a biological sample, the biological sample is not limited to a nucleic acid. A “reaction solution” is meant to contain at least the sample and to further contain a buffer solution, a compound, an enzyme, and so on, as appropriate, necessary for reaction with an injected reagent solution and luminescent reaction.
[0074] The reaction cells 6 are provided via a reaction cell holder 7 in the middle of a tray 8 freely coming in and out. On operation of the apparatus, as the tray 8 is housed into the apparatus, the reaction cells 6 are carried in the apparatus and positioned in the respective lower perpendicular directions of the capillaries 18 communicating with the reaction tubes 17 . When the reaction cells 6 are removed or replaced, the reaction cells 6 are taken out of the apparatus by pulling out the tray 8 . The tray 8 is held by a guide 27 (see FIG. 4 ) and can come in and out at the push of an eject button 10 installed on the body cover 9 .
[0075] Hereinafter, the present embodiment will be described under the assumption that the tray 8 is housed within the luminescence detection apparatus 1 and four reaction cells 6 are positioned in the respective lower perpendicular directions of the capillaries 18 communicating with the reaction tubes 17 . In addition, the reagent tubes 17 are inserted in the under surface of the reagent tube holder 2 , and the reagent tube holder 2 is mounted on the rotating shaft 3 .
[0076] The body cover 9 , a door 11 , and a light-shielding plate 12 function as light-shielding members for shielding the internal portion of the luminescence detection apparatus 1 from light. The door 11 is appropriately opened for the replacement of reagent solutions and maintenance of the rotating shaft 3 and a solution-dispensing portion 19 (see FIG. 4 ) described below.
[0077] As shown in FIG. 2 , the rotating shaft 3 is rotatably held via a rotating-shaft bearing 28 (see FIG. 4 ) in the upper portion of a base 13 in the horizontal direction of the base 13 . A shield 14 surrounding the rotating shaft 3 in a U shape is further provided in the upper portion of the base 13 to prevent stray lights and electrical noises.
[0078] On the other hand, a shield case 15 accommodating the tray 8 holding the reaction cells 6 and photosensors 24 (see FIG. 4 ) for detecting light generated in the reaction cells 6 is provided below the base 13 .
[0079] The base 13 is held by a stand 16 .
[0080] Next, referring to FIG. 3 and FIG. 4 , the luminescence detection apparatus 1 according to the present embodiment will be described in detail.
[0081] FIG. 3 is a view illustrating corresponding arrangements between the capillaries 18 communicating with the reagent tubes 17 and the reaction cells 6 .
[0082] When the reagent tubes 17 , the capillaries 18 , and the reaction cells 6 are represented by individual components for describing each corresponding arrangement, reference numerals with alphabetical suffixes such as 17 a , 17 b , 17 c , and 17 d (in the case of the reagent tubes) are used. When the components are indicated collectively, they are described, for example, as represented by reagent tube(s) 17 .
[0083] Each of four reagent tubes 17 a to 17 d contains each one (but different from those in the other reagent tubes) of four different deoxynucleotide solutions (containing dATP, dCTP, dGTP, or dTTP) or derivatives thereof as a reagent solution. The reagent solutions are respectively discharged from four capillaries 18 a to 18 d respectively communicating with the reagent tubes 17 a to 17 d by air pressure that is supplied from the pressure pipe 4 . Four reaction cells 6 a to 6 d respectively put into a one-to-one correspondence with the capillaries 18 a to 18 d are arranged in the respective lower perpendicular directions of the capillaries 18 a to 18 d . The reagent solutions discharged from the capillaries 18 a to 18 d are injected into the reaction cells 6 a to 6 d positioned in the respective lower perpendicular directions of the capillaries 18 a to 18 d.
[0084] FIG. 4 is a vertical sectional view taken along the alternate long and short dash line A-A′ in FIG. 2 in a perpendicular direction, which shows the substantial part of the luminescence detection apparatus 1 shown in FIG. 2 from the direction of the arrows.
[0085] The solution-dispensing portion 19 is composed of the reagent tubes 17 , the capillaries 18 communicating with the reagent tubes 17 , a gas passage 20 formed within the reagent tube holder 2 , the rotating seal 5 , the pressure pipe 4 , and a pressure source (not shown).
[0086] Four convex portions 21 for hermetically sealing the openings of the reagent tubes are formed in the under surface of the reagent tube holder 2 . After the openings are hermetically sealed, a gas inlet 20 a that is the lower end of the gas passage 20 is formed on the protrusion side of each of the convex portions 21 that comes in no contact with the internal wall of each reagent tube. The gas passage 20 branches off in the reagent tube holder 2 according to the number of the gas inlet 20 a , that is, the number of the reagent tube 17 installed in the reagent tube holder 2 . It is preferred that the gas inlet 20 should be provided at an angle that does not permit the direct discharge of gas to the surface of the reaction solution in order to prevent the reaction solution from scattering.
[0087] An upper end 20 b of the gas passage 20 is connected via the rotating seal 5 to the pressure pipe 4 . The gas passage 20 allows the reagent tube 17 to communicate with the pressure pipe 4 . The pressure pipe 4 is connected via a pressure-switching device such as an electromagnetic valve (not shown) to a pressure source (not shown) such as a high-pressure cylinder or a compressor having 3 atm. (0.3 MPaG) or more. The rotating seal 5 is provided in the middle of the rotating shaft 3 , and the pressure pipe 4 is not distorted even when the rotating shaft 3 revolves.
[0088] The reaction solutions in the reagent tubes 17 are preferably delivered to the reaction cells 6 by constant-pressure liquid delivery.
[0089] The constant-pressure-pressurized liquid delivery method employs compressed air (approximately 1 to 2 atmosphere(s) (0.1 to 0.2 MPaG)) from the pressure source to perform liquid delivery by the application of air pressure for approximately a few seconds with a pressure-switching device such as an electromagnetic valve.
[0090] Because the pressure sent from the pressure source via the pressure pipe 4 is uniformly fed into all of a plurality of reagent tubes 17 , the reagent solutions can simultaneously be discharged from all of the reagent tubes 17 by one-time work for feeding gas. Such construction can simplify the luminescence detection apparatus 1 .
[0091] The discharge rate of the reagent tube 17 by the constant-pressure-pressurized liquid delivery method used in the present embodiment is determined according to the following Hagen-Poiseuille equation (1):
Q=ΔP·π·r 4 ·t /(8 μL) (1).
[0092] In the equation (1), ΔP represents applied pressure; r represents the internal diameter of a narrow tube of small diameter; t represents the duration of pressurization; μ represents the viscosity of a solution; and L represents the length of the narrow tube of small diameter.
[0093] As shown in the equation (1), capillaries (narrow tubes of small diameter) 18 are members for controlling flow rates in the constant-pressure-pressurized liquid delivery method. Therefore, the selection of capillaries 18 with varying internal diameters and lengths allows the adjustment of flow rates.
[0094] For example, the use of the capillary 18 with an internal diameter of 25 μm and a length of 20 mm is preferred for satisfying the conditions: the use of low pressure in the order of atmospheric pressure (2 atm. (0.2 MPaG) or less), the duration of pressurization of 2 seconds or less, and a discharge rate of 0.2 μL or less.
[0095] The rotating shaft 3 revolves with a rotating motor 22 as driving force. Since the reagent tube holder 2 is mounted on the upper portion of the rotating shaft 3 as described above, the reagent tube holder 2 and the reagent tubes 17 installed in the reagent tube holder 2 also revolve with the revolution of the rotating shaft 3 .
[0096] Four through-holes 23 are formed in the internal portion of the rotating shaft 3 along the shaft direction in order to house four reagent tubes 17 installed in the reagent tube holder 2 .
[0097] The rotating motor 22 can be controlled by motor-controlling means (not shown). For example, the motor-controlling means may be a controller (CPU) implementing a program that defines an angle of rotation, a time interval between rotation events, and so on. In the present embodiment comprising four capillaries 18 and for reaction cells 6 , preferred is programmed control that allows the rotation of the capillaries 18 and the reaction cells 6 at a 90° angle at predetermined periods. Alternatively, instead of the use of the time interval, control may be conducted by a program that defines the capillaries 18 and the reaction cells 6 so that they are turned at a predetermined angle, every time detected luminescent intensity decays at or under a given value.
[0098] The reaction cells 6 each have a bottom portion made of a transparent member. The reaction cells 6 are inserted from above and engaged in through holes circumferentially formed within the reaction cell holder 7 . As a result, the reaction cells 6 are constructed to allow the detection of lights generated in the reaction cells 6 at a position below the bottom portions of the reaction cells 6 . The bottom portions of the reaction cells 6 may be substantially transparent and are not necessarily required to pass lights of all wavelengths therethrough. The bottom portions of the reaction cells 6 may allow the transmission of at least a light of a wavelength desired to be detected. Moreover, the transmission of a light with 100% efficiency is not necessarily required. If the accurate transmittance of light is known, a measurement value may be corrected on the basis of this transmittance after measurement.
[0099] The light-detecting portion 29 comprises at least the photosensors 24 and an amplifier 25 electrically connected for amplifying a signal detected by the photosensors 24 and is housed in the shield case 15 mounted on the base 13 .
[0100] The photosensors 24 are arranged in a one-to-one correspondence with the reaction cells 6 in the lower perpendicular directions of the reaction cells 6 . By arranging the photosensors 24 in a one-to-one correspondence with the reaction cells 6 , lights can be detected with high sensitivity regardless of the intervals, arrangement, and size of reaction cells 6 . Although the amplifier 25 assumes the construction where four photosensors 24 are connected to one amplifier 25 in consideration of an output error occurring in each amplifier 25 , the amplifier 25 is not necessarily limited to this construction.
[0101] In the present embodiment, the photosensors 24 are used as contact photosensors for enhancing light-gathering efficiency in a simple manner without the use of a complicated optical system that employs lens and so on, in such a way that the photosensors 24 are kept as close to the reaction cells 6 as possible to increase a light-receiving angle. Therefore, the luminescence detection apparatus is constructed to be capable of attaining reduction in the number of components and high light-gathering efficiency in a simple structure that does not require the adjustment of an optical axis. However, depending on the construction of the apparatus, a lens, a light-gathering device, or the like, is appropriately placed between the reaction cells 6 and photosensors 24 without limitations.
[0102] In the present embodiment, the photosensors 24 are arranged in proximity to the reaction cells 6 as described above, and the amplifier 25 of high amplification is used. Therefore, the detection of a noise (very small false current) by electrostatic induction becomes a problem. This noise tends to be detected during the injection of reagent solutions or during the vibration of the reaction cell holder 7 or the tray 8 involved in stirring described below.
[0103] For eliminating this noise, the luminescence detection apparatus in the present embodiment is allowed to comprise a transparent conductive layer 26 a between the reaction cells 6 and photosensors 24 that corresponds to these reaction cells 6 .
[0104] FIG. 5 ( a ) is an enlarged fragmentary sectional view illustrating the attachment mode of the transparent conductive layer 26 a of the present embodiment.
[0105] As shown in FIG. 5 ( a ), the luminescence detection apparatus is constructed so that a quartz glass plate 26 having excellent light transmittance and chemical stability is provided in the top surface of the shield case 15 containing the upper perpendicular direction of the photosensor 24 and the under surface of the quartz glass plate 26 is coated with the transparent conductive layer 26 a consisting of ITO (indium oxide) or SnO 2 . As described above, the transparent conductive layer 26 a is not fixed in the reaction cells 6 but provided separately from the reaction cells 6 . This can reduce costs required for the reaction cells 6 and can provide the reaction cells 6 that are disposable. The transparent conductive layer 26 a is grounded face-to-face with the shield case 15 and attached to the shield case 15 with a conductive adhesive or the like.
[0106] In the present embodiment, the transparent conductive layer 26 a is constructed separately from the reaction cell 6 and however, is not limited to this construction. For example, the transparent conductive layer 26 a may be formed integrally with the reaction cell 6 .
[0107] Here, FIG. 5 ( b ) is an enlarged fragmentary sectional view illustrating the application of the attachment mode of a typical transparent conductive layer 26 a . In the present embodiment as well, for example, the luminescence detection apparatus can be constructed so that the quartz glass plate 26 is applied to a member for the bottom portion of the reaction cell 6 as shown in FIG. 5 ( b ) and the under surface of the quartz glass plate 26 is coated with the transparent conductive layer 26 a consisting of ITO or SnO 2 , when the transparent conductive layer 26 a does not assume the construction as shown in FIG. 5 ( a ) where the transparent conductive layer 26 a is provided separately from the reaction cell 6 .
[0108] In the present embodiment, the amount of the reagent solution injected at a time into the reaction cell 6 is approximately one hundredth the amount of the reaction solution dispensed in advance in the reaction cell 6 and is relatively small. Thus, for properly detecting luminescent intensity caused by reaction, it is preferred to stir the reaction cell 6 immediately after the injection of the reagent solution without waiting for the spontaneous diffusion of the reagent solution.
[0109] One example of stirring means can include a vibration motor.
[0110] The vibration motor (not shown) is installed in the reaction cell holder 7 that holds the reaction cells 6 or the tray 8 that holds the reaction cell holder 7 . All of the reaction cells 6 can collectively be stirred by contacting and vibrating the reaction cell holder 7 or the tray 8 with the vibration motor. A small vibration motor used in, for example, a cellular phone can be utilized as the vibration motor.
[0111] Another example of the stirring means can include magnetic particles.
[0112] Specifically, magnetic particles are added into the reaction cells 6 and moved by the application of a magnetic field to the insides of the reaction cells 6 by magnetic field generation means (not shown) provided outside the reaction cells 6 , thereby stirring the reaction solutions. In this case, stirring for a few seconds after injection may be performed.
[0113] However, when the reaction cells 6 are stirred with the reaction motor, it is necessary to give consideration to the case in which, due to the vibration, the transparent conductive layer 26 a is estranged from the shield case 15 and thereby prevented from being grounded in the shield case 15 . Thus, the influence of stirring with the vibration motor on each attachment mode of the above-described transparent conductive layer 26 a will be described with reference to Experimental Examples.
[0114] It is noted that stirring with the magnetic particles does not cause the vibration of the reaction cells 6 , so that the above-described problem may not be considered.
EXPERIMENTAL EXAMPLE 1
[0115] In Experimental Example 1, experiments have been conducted for showing the influence of stirring with the vibration motor when the attachment modes of the transparent conductive layer 26 a of the present embodiment shown in FIG. 5 ( a ) and a typical transparent conductive layer 26 a shown in FIG. 5 ( b ) are applied.
[0000] [Detection Conditions]
[0116] The performance of the quartz glass plate 26 coated with the transparent conductive layer 26 a , which was used in Experimental Example 1 has 90% or more transmittance at a wavelength of 450 to 600 nm and a sheet resistivity of 1000 to 1500 Ω. Photodiode S1133-01 manufactured by Hamamatsu Photonics was used as the photosensor 24 whose output was amplified to 1×10 10 using a current-to-voltage conversion amplifier (OPA129UB, manufactured by BURR BROWN) and a resistivity of 10 GΩ and subsequently amplified to a total gain of 1.8×10 11 using an operational amplifier in the second stage (OP07, manufactured by ANALOG DEVICES).
[0117] Experimental Example 1 is measurement for detecting a noise and as such, does not use reagent solutions and reaction solutions.
[0000] [Experimental Result]
[0118] FIG. 7 ( a ) shows a result of measuring a noise in the attachment mode of the transparent conductive layer 26 a of the present embodiment (see FIG. 5 ( a )), while FIG. 7 ( b ) shows a result of measuring a noise when the attachment mode of the typical transparent conductive layer 26 a is applied (see FIG. 5 ( b )). In both FIG. 7 ( a ) and FIG. 7 ( b ), no noise is detected. Namely, because stirring by vibration is not performed in both cases, the transparent conductive layers 26 a are grounded in the shield cases 15 and their function of blocking noises effectively works.
[0119] FIG. 6 ( a ) is a schematic view illustrating the state of stirring with the vibration motor in the attachment mode of the transparent conductive layer 26 a of the present embodiment (see FIG. 5 ( a )). A result of measuring a noise during stirring is shown in FIG. 7 ( c ). In FIG. 7 ( c ), no noise is detected. Even if the reaction cell 6 moves up and down when vibrated and stirred with the vibration motor, the transparent conductive layer 26 a is attached to the shield case 15 and therefore, its function of blocking noises effectively works.
[0120] FIG. 6 ( b ) is a schematic view illustrating the state of stirring with the vibration motor when the attachment mode of the typical transparent conductive layer 26 a is applied (see FIG. 5 ( b )). A result of measuring a noise during stirring is shown in FIG. 7 ( d ). In FIG. 7 ( d ), a noise was detected (which shows that signal intensity in the order of −0.04 V was detected on 15 seconds). This is because the reaction cell moves up and down by vibration stirring, so that the transparent conductive layer formed in the bottom part of the reaction cell is estranged from the shield case 15 and thereby prevented from being grounded in the shield case 15 .
[0121] Thus, the results of Experimental Example 1 have demonstrated that the attachment mode of the transparent conductive layer 26 a of the present embodiment (see FIG. 5 ( a )) is preferred when the vibration motor is used as stirring means.
EXPERIMENTAL EXAMPLE 2
[0122] In Experimental Example 2, experiments have been conducted for investigating the optimum conditions of stirring with the vibration motor.
[0000] [Detection Conditions]
[0123] The amount of the reaction solution used in the reaction was 20 μL, and 0.2 μL of the reagent solution (deoxynucleotide solution) was injected. The amount of sample DNA (template DNA) remaining after the same reagent solution (deoxynucleotide solution) was injected again for further reaction was regarded as the amount of unreacted sample DNA (template DNA). See “Table 1” in Example described below, for the compositions of the reagent solution and the reaction solution.
[0124] The settings of the apparatus and so on were conducted in accordance with the detection conditions of Experimental Example 1.
[0000] [Experimental Result]
[0125] FIG. 8 shows correlation between the frequency of the vibration motor and the percentage of the DNA strand unreacted.
[0126] When the stirring frequency of the vibration motor was 20 Hz or more, the percentage of the DNA strand unreacted fell off at or below a few percent. As can be seen, especially in a stirring frequency of 25 Hz or more, the percentage of the DNA strand unreacted is almost 0%, and the reaction completely proceeds. The use of larger stirring frequencies, though graphical illustration is omitted, causes the reaction cell 6 not to vibrate and, on the contrary, reduces reaction efficiency. In a stirring frequency of 100 Hz or more, 10% or more DNA strand is unreacted.
[0127] It will be recognized that various changes can be made to the present invention described above within the technical concept of the present invention. For example, although the present embodiment is expressed in the construction where the reaction cells 6 do not move and the capillaries 18 rotate, the luminescence detection apparatus may assume construction where the capillaries 18 do not move and the reaction cells 6 rotate.
[0128] Although the number of the reaction cell is set to four in response to types of bases in the present embodiment illustrated above, the reaction cells in multiple of 4 such as 8, 12, or 16 may be provided. Furthermore, the number of the reaction tube may appropriately be increased with increase in the number of the reaction cell. Hereinafter, Modification Examples made to the number of the reaction cell will be described, appropriately referring to the drawings.
[0129] FIG. 9 is an illustration of Modification Example 1 to the number of the reaction cell.
[0130] Modification Example 1 assumes construction where, in addition to four reaction cells 106 a to 106 d , four reaction cells 106 e to 106 h are further provided in the respective outer circumferential directions of the reaction cells 106 a to 106 d . Moreover, capillaries 118 a to 118 h communicating with reagent tubes 117 a to 117 h are arranged in the respective upper perpendicular directions of the reaction cells 106 a to 106 h . In Modification Example 1, each of reagent tubes 117 a to 117 d and each of reagent tubes 117 e to 117 h contain each one (but different from those in the other tubes) of four different deoxynucleotide solutions (containing DATP, dCTP, dGTP, or dTTP) or derivatives thereof.
[0131] Such construction allows increase in the number of the reaction cell 6 without increasing the number of the rotating shaft 3 and therefore allows increase in the number of a sample that can be analyzed at a time.
[0132] FIG. 10 is an illustration of Modification Example 2 to the number of the reaction cell.
[0133] When the capillaries adjacent to each other along the radial direction of the reaction cell holder (e.g., 218 a and 218 e ) discharge identical reagent solutions as shown in FIG. 10 , the apparatus may be constructed so that a plurality of capillaries 218 are allowed to communicate with one reagent tube 217 . Such construction allows reduction in the number of the reagent tube 217 and therefore allows the simple replacement of the reagent solution.
[0134] FIG. 11 is an illustration of Modification Example 3 to the number of the reaction cell.
[0135] In Modification Example 3, the reaction cells 306 a to 306 h in multiple of 4 are arranged at equal intervals on the same circumference. Moreover, capillaries 318 a to 318 h communicating with reagent tubes 317 a to 317 h are arranged in the respective upper perpendicular directions of the reaction cells 306 a to 306 h . In this case, the capillaries may be arranged so that the capillaries in order of, for example, 318 a , 318 b , 318 c , 318 d , 318 e , 318 f , 318 g , and 318 h discharge reagent solutions containing DATP, dGTP, dCTP, dTTP, DATP, dGTP, dCTP, and dTTP, respectively, with them turned at a 45° angle. Such construction allows increase in the numbers of the reaction cell 6 and the reagent tube 17 without increasing the numbers of the rotating shaft 3 and the solution-dispensing portion 19 . As compared to the angle of rotation of 90° in the above-described embodiment, the work of the rotating motor 22 that drives the rotating shaft 3 can be reduced.
[0136] The application of a 96-well microplate with 8 wells per column versus 12 wells per row to the reaction cell will be described as Modification Example 4, though not illustrated, to the number of the reaction cell. Modification Example 4 can assume construction where one solution-dispensing portion 19 , that is, four capillaries 18 shown in FIG. 3 are successively arranged in the respective upper perpendicular directions of a total of 4 wells of 2 vertically-adjacent wells and 2 horizontally-adjacent wells in the 96-well microplate. Such construction allows the use of up to 24 solution-dispensing portions 19 , that is, 96 reagent tubes 17 and 96 capillaries 18 respectively communicating with the reagent tubes 17 , to analyze 96 samples at a time.
[0137] When a commercially-available microtiter plate is applied to the reaction cell 6 , it is preferred that partitions for crosstalk prevention should be provided in the reaction cell holder 7 in order to prevent the crosstalk of luminescences between adjacent wells (reaction cells).
[0138] Alternatively, when the number of the reaction cell 6 is more than the number of the capillary 18 , the solution-dispensing portion 19 may be provided with an actuator and constructed to move to four reaction cells 6 that follow, every time the analysis of four reaction cells 6 is completed.
DESCRIPTION OF PREFERRED EMBODIMENT
[0139] Next, Example where the effect of the luminescence detection apparatus 1 of the present invention has been confirmed will be described more fully, taking DNA base sequencing as an example.
[0140] In the present Example, a base sequence was determined with the luminescence detection apparatus 1 comprising four reaction cells 6 and four reagent tubes 17 in response to four different dNTPs in the construction of the present embodiment as shown in FIG. 3 . Thus, the reaction cells 6 , the reagent tubes 17 , and the capillaries 18 in the present Example may be arranged as in FIG. 3 and will be thus described with reference to the figure.
[0141] The performance of the quartz glass plate 26 coated with the transparent conductive layer 26 a , which was used in the present Example has 90% or more transmittance at a wavelength of 450 to 600 nm and a sheet resistivity of 1000 to 1500 Ω. Photodiode S1133-01 manufactured by Hamamatsu Photonics was used as the photosensor 24 whose output was amplified to 1×10 10 using a current-to-voltage conversion amplifier (OPA129UB, manufactured by BURR BROWN) and a resistivity of 10 GΩ and subsequently amplified to a total gain of 1.8×10 11 using an operational amplifier in the second stage (OP07, manufactured by ANALOG DEVICES).
[0142] The principle of DNA base sequencing conducted in the present apparatus is the detection of pyrophosphate (PPi) generated during the extension reaction of a primer complementarily bound with DNA by a bioluminescent reaction method of a luciferin/luciferase system. Hereinafter, the reaction scheme will be described.
[0143] A primer for extension reaction is hybridized with sample DNA to be measured. DNA polymerase is used to perform DNA complementary strand extension reaction, with the sample DNA and the primer for extension reaction hybridized. On this occasion, when deoxyribonucleotide triphosphate (or analog nucleic acid) solutions used as reagent solutions are added successively but one at a time, PPi is generated, only if DNA complementary strand extension reaction occurs. The PPi generated from the DNA complementary strand extension reaction is converted to ATP by ATP sulfurylase in the presence of APS (adenosine 5′-phosphosulphate) while SO 4 2− (sulfate ion) is generated. The ATP to which the PPi has been converted by ATP sulfurylase is utilized in the oxidation reaction of luciferin by luciferase in the presence of a magnesium ion and O 2 (oxygen), which emits light. During the reaction, CO 2 (carbon dioxide) is generated while ATP is converted to PPi and AMP and luciferin is converted to oxyluciferin. The PPi generated following the bioluminescence of the luciferin/luciferase system is converted again to ATP by ATP sulfurylase in the presence of APS. Therefore, luminescent reaction repeatedly occurs to maintain luminescences. The present DNA base sequencing is a method by which DNTP solutions are added by turns and repeatedly to determine bases one by one in the base sequence, with the presence or absence of luminescence detected (see Ahmadian, A. et al., Analytical Biochemistry 280 (2000) 103-110; and Zhou, G. et al., Electrophoresis 22 (2001) 3497-3504), and can readily be conducted using the luminescence detection apparatus 1 of the present invention.
[0144] Hereinafter, a specific measurement method in the present Example will be described.
[0145] In the present Example, a gene (thiopurine S-methyltransferase gene) shown below was used as sample DNA, and a sequencing primer that had a sequence complementary to the sequence of the 3′ end of the gene was also used.
[0146] The compositions of the reagent solutions and reaction solution used in the present Example are shown in “Table 1”.
[0147] It will be recognized that the compositions and concentrations of the reagent solutions and reaction solution used herein are described as an example of measurement methods and can appropriately be changed according to the construction of apparatuses, sample DNA, and so on.
TABLE 1 Composition of reagents in each solution Reagent dNTP (300 μM dATP α S, 200 μM CTP, solution 200 μM dGTP, or 200 μM dTTP) 5.0 μM APS 10 mM Tris-acetate buffer, pH 7.75 Reaction Sample DNA solution 0.1 M Tris-acetate buffer, pH 7.75 0.5 mM EDTA 5.0 mM magnesium acetate 0.1% (v/v) bovine serum albumin 1.0 mM dithiothreitol 0.1 U/μl DNA polymerase 1, Exo-klenow Fragment 1.0 U/ml ATP sulfurylase 2.0 mg/ml luciferase 20 mM D-luciferin
[0148] A total of 31 μL (of which 1 μL was sample DNA provided with primer annealing treatment and was added just before measurement) of the reaction solution was dispensed in each of the reaction cells 6 , to which 0.3 μL of each of the reagent solutions (deoxynucleotide solutions) was then injected successively to measure luminescent reaction.
[0149] Here, the sample DNA provided with primer annealing treatment is sample DNA (400 fmol) that has been hybridized (95° C., 20 sec.→60° C., 120 sec.→room temperature) with the sequencing primer in an amount 1.5 times the amount of the sample DNA in an annealing buffer (10 mM Tris-acetate buffer (pH 7.75), 2 mM magnesium acetate). However, a method for hybridization between the sample DNA and the sequencing primer is not limited to the foregoing. For example, predetermined temperature operation required for hybridization may be performed after the sample DNA and the sequencing primer are added to the reaction cell 6 .
[0150] In the present Example, the identical reaction solution containing the identical sample DNA is dispensed into four reaction cells 6 .
[0151] The reagent tubes 17 a , 17 b , 17 c , and 17 d retain a dATPαS solution, a dGTP solution, a dTTP solution, and a dCTP solution, respectively, as the reagent solutions. Moreover, each of the reagent solutions contains APS (see “Table 1”).
[0152] In the present Example, an analog dATPαS is used instead of DATP. The dATPαS serves as a substrate as with DATP that is added to the 3′ end of DNA during DNA complementary strand extension reaction to release pyrophosphate, whereas the dATPαS has substrate specificity (i.e., function as substrate) for luciferase equal to or smaller than 2 figures compared with that of DATP and as such, considerably reduces the magnitude of background noises as compared to the use of DATP. Thus, the use of dATPαS as a reagent solution instead of DATP is more preferred because of improved stability.
[0153] The reagent tubes 17 a , 17 b , 17 c , and 17 d are arranged in the upper portions of the reaction cells 6 a , 6 b , 6 c , and 6 d , respectively, immediately after the initiation of measurement.
[0154] A DNA base sequence is determined by the following procedures: DNTP solutions are simultaneously injected to the reaction solutions in four reaction cells 6 ; in a given time, the reagent tubes 17 are turned counterclockwise at a 90° angle; and next DNTP solutions are simultaneously injected thereto.
[0155] Turning now to FIG. 12 , the order of the dNTP solutions injected to each reaction cell 6 in the present Example will be illustrated. Although dATPαS is used instead of DATP in the present Example as described above, the dATPαS is represented by DATP in the drawing for briefly illustrating the relationship among four different dNTPs.
[0156] The time interval between the injections of the reagent solutions is 30 to 90 seconds. In general, one reaction is conducted for 1 minute to ensure the progression of reaction, and the determination of one base in a base sequence requires 4 minutes. However, periods of time required for reaction and determination are appropriately changed according to the compositions of reagent solutions and reaction solutions as well as the base sequence of sample DNA.
[0157] FIG. 13 is detection data of a luminescence in each reaction cell 6 in the present Example. DNA base sequence data in FIGS. 13 ( a ), 13 ( b ), 13 ( c ), and 13 ( d ) respectively correspond to the reaction cells 6 a , 6 b , 6 c , and 6 d shown in FIG. 12 . Overlapping DNA base sequence data were obtained on all of the reaction cells 6 . In the present Example, the base sequence of identical sample DNA is analyzed in four reaction cells 6 as described above.
[0158] The results of the present Example have demonstrated that the use of the luminescence detection apparatus 1 according to the present invention allows the simultaneous and proper determination of a DNA base sequence in all of the reaction cells 6 .
[0159] The apparatus disclosed herein finds great application in industrial fields as a convenient DNA sequencer and even as a DNA inspection apparatus for single-base extension reaction or the like. In addition, the apparatus can also be exploited in bacteriological examinations by ATP measurement or as a small luminometer.
[0160] It should be further understood by those skilled in the art that although the foregoing description has been made on embodiments of the invention, the invention is not limited thereto and various changes and modifications may be made without departing from the spirit of the invention and the scope of the appended claims. | An object of the present invention is to provide a luminescence detection apparatus compact in size which is capable of conveniently determining DNA base sequences at a low cost. According to the present invention, a luminescence detection apparatus 1 is provided comprising: a plurality of reaction cells 6 each having a transparent bottom portion; a solution-dispensing portion 19 equipped with capillaries 18 positioned above the reaction cells 6 and put into a one-to-one correspondence with the reaction cells 6 ; and a light-detecting portion 29 having a plurality of light-sensing elements 24 put into a one-to-one correspondence with the reaction cells 6 and arranged in proximity to the bottom surfaces of the reaction cells 6 , wherein the a plurality of light-sensing elements 24 of the light-detecting portion 29 detect respective luminescences in the reaction cells 6 generated by injecting reagent solutions from the solution-dispensing portion 19 to the reaction cells 6. | 6 |
FIELD OF THE INVENTION
This invention is directed to a method and apparatus wherein the fatigue failure of a structure of different materials due to thermal cycling can be predicted by the fatigue failure of test strips of a second material attached to a base of first material.
BACKGROUND OF THE INVENTION
Even when stressed below its ultimate strength, repeated stress on a mechanical part can cause failure due to fatigue. Fatigue life has been studied in many materials, and particularly those materials which are employed in the building of structures which are intended to have long life, but which are designed close to the ultimate strength limit. Such structures are subject to fatigue failure when repetitive stresses below the ultimate strength are encountered. Fatigue strength is principally a function of the materials, the manner in which the material has been treated, temperature, the amount of stress, and the number of cycles.
In the various fields of electronics, there is a wide variety of materials used in physical conjunction with each other. Semiconductor materials are connected by metal connectors and are mounted on non-conductive bases, such as ceramic or filled organic bases. Each of these structures has different thermal expansion properties and, as a result of thermal cycling, fatigue stresses are created and fatigue failure can take place. It is important in many electronic structures to be able to predict fatigue failure so that a part can be replaced before failure. When electronic assemblies are in operation, the remaining useful life is unknown, but many fail due to separation of different parts due to repeated thermal stress. A thermal fatigue testing method and apparatus therein will allow monitoring of leftover life.
SUMMARY OF THE INVENTION
In order to aid in the understanding of this invention, it can be stated in essentially summary form that it is directed to a fatigue testing method and apparatus wherein each of a plurality of fatigue life test strips is anchored in a base so that the test strips are subject to the same fatigue cycling as the parent structure, which may be on the same base. Electrical monitoring of the continuity of each test strip signals its failure by fatigue due to stress cycling to predict the remaining life in the associated structure.
It is thus a purpose and advantage of this invention to provide a thermal fatigue testing method and apparatus which is suitable for application to the structure which is subject to repeated stress which causes fatigue failure and to signal when fatigue failure is incipient.
It is another purpose and advantage of this invention to provide a fatigue testing method and apparatus wherein test strips are incorporated into an electronic device and are electrically tested for continuity so as to signal fatigue failure of the test strips.
It is another purpose and advantage of this invention to mount a fatigue test apparatus directly on an electronic device so as to signal incipient fatigue failure between dissimilar parts of the electronic device.
Other purposes and advantages of this invention will become apparent from a study of the following portion of this specification, the claims and the attached drawings wherein:
BRIEF DESCRIPTION OF THE DRAWINGS
FIG. 1 is an isometric view of a first preferred embodiment of a thermal fatigue testing apparatus of this invention and employing the method of this invention.
FIG. 2 is an enlarged isometric view of one of the fatigue life test strips shown in FIG. 1.
FIG. 3 is an electronic schematic diagram of one way of testing the continuity of the fatigue life test strip shown in FIGS. 1 and 2.
FIG. 4 is an isometric view of a second preferred embodiment of a thermal fatigue testing apparatus in accordance with this invention and employing the method of this invention.
DESCRIPTION OF THE PREFERRED EMBODIMENT
The first preferred embodiment of the thermal fatigue testing apparatus of this invention is generally indicated at 10 in FIG. 1. The apparatus comprises a base 12 which is usually mounted on a substrate 14. The base 12 has a plurality of pockets therein, and closely fitting into each of the pockets is a test strip. Test strips 16, 18, 20 and 22 are illustrated in FIG. 1, and test strip 16 is shown in more detail in FIG. 2. The test strips are made of a different material than the base 12. The anchor ends of the test strips are locked into corresponding pockets in the base and, thus, upon temperature cycling, differential expansion and contraction of the different materials in the test strip and base cause stresses in the test strip. In a particular example, the substrate 14 is a printed wiring board, with conductive paths thereon. When the substrate is organic, such as fiberglass-filled epoxy or other thermosetting resin material, the printed wiring is usually in the form of a copper layer which has been etched into the desired electrical configuration. When the substrate 14 is ceramic, usually the printed wiring thereon is gold deposited thereon. The base 12 may be a semiconductor having an integrated circuit or other electronic devices formed therein. The semiconductor devices may be formed around the pockets which contain the test strips or on the opposite side of the semiconductor base. Sometimes the semiconductor would be incorporated into a package which is then secured to the substrate 14.
In the preferred embodiment, the base 12 is a semiconductor with integrated circuitry formed thereon. Also formed in the base 12, as seen in FIG. 1, is a plurality of pockets, each containing one of the test strips. Pocket 24 is shown in dashed lines for receiving the test strip 16. By defining the test strip, the pocket is also defined. The pocket for the insertion of the test strip is formed by etching.
Referring to FIG. 2, test strip 16 has anchors 26 and 28 formed integrally therewith. The anchors have inner and outer bearing surfaces. Inner bearing surface 30 and outer bearing surface 32 are shown for anchor 26, while inner bearing surface 34 and outer bearing surface 36 are shown for anchor 28. These bearing surfaces are generally flat, with the planes of each bearing surface lying parallel to each other. It is these bearing surfaces which transfer the stresses from the base 12 to the test strip 16. Bridge 38 is of substantially uniform thickness from its top surface 40 to its bottom surface 42 throughout its length. The width of the bridge between left and right sides 44 and 46 varies, being widest close to the anchor and narrowest at the center neck 48. The neck is narrow to provide the stress raiser. The neck is also provided with a stress-raising hole 50. The center neck and stress-raising hole assure that the point of highest stress on the bridge will be at the center so as to define the location which is going to break. In order to concentrate the stresses on the bridge itself at the neck thereof, the base 12 is etched away around the neck. In FIG. 1, the etched-out opening around the neck 48 is indicated at 49. As is seen in FIG. 1, the necks of the bridges 16, 18, 20 and 22 are progressively narrower. Each may have a stress-raising hole at the center of the neck. Each of the other test strips has the same anchors and has the same thickness of bridge, with only the width of the center neck of the bridge varying.
The base 12 is made of a material of lower electrical conductivity, such as a semiconductor or a dielectric. The test strips are each made of the same metal. The base and the test strip materials are chosen to represent the materials associated with the base, substrate, pads on the substrate or connections which are to be tested for thermally caused fatigue. The pockets are made, and the test strips are placed by electroplating them or ion-beam depositing them therein. When the fatigue testing is for connection, adhesion or attachment in the semiconductor environment, the pockets may be quite small, for example, 50 microns long between surfaces 32 and 36. It can be appreciated that the test strips are very small and their pockets are etched into the base. Thus, the regularity of the shapes of the anchors, as shown in FIG. 2, is ideal. Such regularity will not be achieved in practice in such small sizes.
As the structure goes through thermal cycling, the differential coefficient of thermal expansion between the materials of the base and the test strips causes tension and compression of the test strip. Since the center necks of the test strip differ, the stresses thereon are greater with those test strips with the narrower neck. Thus, the test strip with the narrowest neck is expected to separate first.
The thermal coefficient of expansion of the materials of interest; for example, aluminum on silicon or gallium arsenide semiconductor bases, is quite different. The coefficient for aluminum is much higher than for the base material. For example, the thermal coefficient of expansion of aluminum is 11×10 -6 in.×in. -1 ×°F. -1 while the semiconductor materials are in the range of 2×10 -6 . What this means is that, if the bridge is deposited at room temperature and thermal cycling raises the temperature, then the bridge goes into compression as the temperature is raised and comes back to 0 tension at room temperature. Even if this type of cycling created the desirable fatigue stresses, since the system returns to 0 tension at room temperature, a break in the bridge might not be electrically detectable since the parts would be lying together. Both from a fatigue viewpoint and from a detection viewpoint, it is desirable to have tension in the test strip at room temperature or normal operating temperature. To accomplish this, the test strip is deposited at an elevated temperature, preferably at about the upper limit of normal operating temperature of the semiconductor device. A temperature of 80° C. is a desirable. In this case, at 80° C., the bridge has 0 tension therein and, as the device cools down to room temperature, the bridge has tension therein. Deposition should not be at too high a temperature in order to avoid stresses in the bridge which approach yield strength.
A sensor circuit 62 is connected to each of the test strips to electrically determine if disconnection occurs. An attachment pad is provided at each end of each test strip. For example, attachment pad 63 is provided at the left end of test strip 16, as seen in FIGS. 1 and 2. Each of the test strips has an attachment pad at each end, as seen in FIG. 1. The test circuit 62 has voltage source 64 and current meter 66 connected in series to line 68, which is connected to one end of all of the test strips. The other end of each of the test strips is connected through its own MOS diode and back to the current meter 66. Test strip 16 is connected through MOS diode 70, and test strip 18 is connected through MOS diode 72. In addition, test strip 20 is connected through MOS diode 74, and test strip 22 is connected through MOS diode 76, all being connected together to the current meter 66. In this circuitry, when there is a failure in a test strip, the corresponding MOS diode permanently opens the circuit. This is for situations in which the test strip may separate under tension, but reclose after the stress is removed. In order to avoid false signals of this nature, the test circuit 62 is provided. In addition, despite the differing resistances in the differing test strips, the MOS diodes will represent substantially equal stepwise increases in resistance as the test strips fail due to the electronic characteristics of the diodes.
The test strips 16-22 are mounted on a base 12 which is preferably a semiconductor base, and the test strips are plated into the pockets on the semiconductor. The semiconductor base 12 is mounted near critical electronic components. On the other hand, the base 12 is the semiconductor chip on which the critical electronic components are formed. While the test strips are shown as lying parallel to each other, such is not a necessary limitation in the layout of test strips on the base 12. They may be laid out in any desirable organization for convenience of space saving, connections, photolithography methods, and deposition procedures. Any convenient physical arrangement on the base is acceptable as long as the several strips are subjected to the proper stresses to achieve the desired fatigue life testing. Because of the small size and proximity of the test strips to the critical electronic components, they will experience the same thermal profile as the host critical electronic components. Since the test strips and base are made of the same materials as the critical electronic components, it will replicate the actual hardware. In thermal cycling causes the same stresses in the test strips as in the critical electronic components. As a result, the test strips measure aging in the host electronic components.
The embodiment of FIG. 4 is an apparatus which represents a second preferred embodiment of the thermal fatigue testing apparatus of this invention. The apparatus of FIG. 4 includes a base 78 on which test strips are mounted. In the present instance, test strips 80, 82, 84 and 86 are illustrated. While four are shown, a larger or lesser number may be employed, depending upon test requirements. The apparatus of FIG. 4 is the same as the apparatus of FIG. 1 except that the test strips are plated onto the top surface of base 78, rather than plated into pockets therein. For the ends of the test strips to be anchored to the base in order to permit the test strips to be stressed and tensioned, the ends of the test strips are large. For example, test strip 80 has a larger triangle 88 on one end and a large triangle 90 on the other separated by neck 92. The triangles on each of the test strips are substantially the same, but they converge to the neck. Each neck is of different width, with the neck 92 wider than the neck on test strip 86. The necks are progressively narrower. The test strips are plated onto the top surface of base 78 in conventional way, such as by plating through a mask opening. In this way, the test strips can be very small, in the order of 50 microns long. The necks can be narrow with the narrowest neck down to the lower limit of manufacturing capability, about 3 microns, and increasing up to about 20 microns.
If the test strips are attached to the base over their entire length, then there would not be localized stress at the neck to provide fatigue life information. In order to free the center part of the test strip under the neck, groove 94 is etched under the neck. As shown in FIG. 4, the groove 94 extends under the necks of each of the test strips. The width of the groove is critical because it is over the width of the groove that the difference in the thermal coefficient of expansion of the two materials is effective.
Each of the test strips is connected to test circuitry, such as that shown in FIG. 3. Two electrical connection pads are provided on each test strip so that the individual continuity of each test strip can be tested and signaled, such as by the circuit of FIG. 3. A connection pad 96 is shown at the left end of test strip 80 in FIG. 4, and a corresponding connection pad is shown at each end of each of the test strips. As with the apparatus 10, the apparatus shown in FIG. 4 has a base of semiconductor material which may be part of or is attached to an integrated circuit chip. The material of the test strips corresponds to another material in the electronic system. It may be a printed wiring conductor material such as copper, nickel, silver or gold, or it may be an attachment material such as solder. Pads are provided on each of the test strips in FIG. 4 so that they may be connected as indicated in FIG. 3. As described above, the plating on of the test strip onto base 78 is preferably accomplished at a raised temperature so that the test strip remains in tension through its operating cycle, which has as its upper limit the normal operating temperature of the semiconductor with which it is associated down to room temperature, which is presumed to be the non-operative temperature of the semiconductor device. In cases where the semiconductor operates over a different temperature range, the temperature of application of the test strip is chosen so that the test strip remains in tension over a substantial portion of its operative range.
The base 12 is preferably part of the semiconductor device itself with the pockets etched into a portion of a semiconductor wafer adjacent electronic components thereon. Alternatively, the base may be the base 78 in the structure of FIG. 4. The base is preferably part of the semiconductor device itself. While such is preferred, the base can be a separate chip attached in another location which experiences the same thermal profile as the host electronic counterpart. The base and test strips are made of the same materials as the hardware in question to replicate the actual hardware experience. In this way, in operation it will measure aging of the host electronic components. The thermal cycling fatigue life is directly monitored by the test circuitry and can provide an always available output signal so that continual fatigue analysis can be achieved. This can be accomplished because the apparatus operates completely passively, except for the resistance measurements made as often as data is desired.
The test strips are stated as being able to be made as small as 50 microns long. The width of the neck of the test strip can be as small as 0.3 micron. The thickness of all of the test strips is preferably equal to aid in the etching process. The size of the anchors is such as to accurately transfer load between the base and the test strips.
This invention having been described in its most preferred embodiment, it is clear that it is susceptible to numerous modifications, modes and embodiments within the ability of those skilled in the art and without the exercise of the inventive faculty. Accordingly, the scope of this invention is defined by the scope of the following claims. | A plurality of fatigue life test strips (16, 18, 20, 22) has each of the strips anchored to a base (12) which is subject to thermal cycling and consequent dimensional change which causes fatigue. The base is, at best, semiconductive, and the strips are conductive. The conductivity of each of the strips is measured by test circuit (52) so that, when one fails due to fatiguing, the failure is signaled. | 6 |
This application is a national filing pursuant to 35 U.S.C Section 371 based on PCT/JP02/13630, filed Dec. 26, 2002.
BACKGROUND OF THE INVENTION
1. Field of the Invention
This invention relates to a base isolation device for a structure, and more particularly to a base isolation device for a structure that is applied to a structure having structural members such as slabs in elevated freeways, elevated railway tracks, or bridge constructions, and suppresses vibration in the out-of-plane direction of the structural members.
Moreover, the invention can also be applied to a base isolation device that suppresses vibration in the out-of-plane direction of structural members of an inclined roof, or structural-support members of a vertically placed glass curtain wall.
2. Description of the Related Art
In recent years, various measures have been employed for suppressing damage such as collapse or failure of structures comprising structural elements such as the slabs in elevated freeways, elevated railway tracks, or bridge constructions due to vertical vibration of the structural members that occurs during traffic vibration or an earthquake, and one of the measures that has been proposed is the base isolation device shown in FIG. 5 .
The base isolation device that is indicated by reference number 1 in this FIG. 5 , is applied to a floor slab 3 that is arranged horizontally as a structural member that is supported by a plurality of bridge supports 2 , for example, and underneath the floor slab 3 , in about the center between the bridge supports 2 , an elastic member 4 comprising a spring or the like, and a damping member 5 comprising an oil damper or the like are suspended such that they are parallel with each other, and a weight member 6 is attached to the bottom section of the elastic member 4 and damping member 5 .
In this prior base isolation device 1 constructed in this way, when vibration in the out-of-plane direction (in the vertical direction in the example shown in the FIG. 5 ) occurs in the floor slab 3 , the vertical vibration of the floor slab 3 is suppressed by damping the relative motion between the floor slab 3 and the weight member 6 by the elastic member 4 and damping member 5 .
In this kind of prior art, there still remain the following problems that must be improved.
In other words, in the prior art described above, in order to efficiently suppress the vertical vibration in the floor slab 3 , it is necessary to properly set the elastic coefficient of the elastic member 4 and the damping coefficient of the damping member 5 in accordance to the characteristic natural frequency of the floor slab 3 , however, in order to do this, there is a problem in that the range capable of obtaining an effective base isolation function is narrow, and the setting of which is difficult.
Moreover, the weight member 6 is more effective the heavier it is, however, in an actual structure, it was difficult to attach a weight that was 10% the weight of the entire structure.
Furthermore, since the weight member 6 acts only in the direction of gravitational acceleration, installing this prior base isolation device in the structural members of an inclined roof, or the structural-support members of a vertically placed glass curtain wall was impossible.
SUMMARY OF THE INVENTION
Taking these prior problems into consideration, the object of this invention is to provide a base isolation device for a structure that is capable of effectively suppressing vibration in the out-of-plane direction of the structural members of a structure.
In order to accomplish the object described above, the base isolation device for a structure according to the first embodiment of the invention is a base isolation device for a structure that suppresses vibration in the out-of-plane direction of a structural member of the structure and comprises: In the base isolation device for a structure according to the seventh embodiment of the invention, the damping member of any one of the described embodiments is an active damper, and together with locating a sensor for detecting shaking on said structural member, a controller is installed that adjusts the operation of said active damper based on the detection signal from the sensor.
In the base isolation device for a structure according to the eighth embodiment of the invention, the sensor of the seventh embodiment is an acceleration sensor.
In the base isolation device for a structure according to the ninth embodiment of the invention, the sensor of the seventh embodiment is a displacement sensor.
In the base isolation device for a structure according to the tenth embodiment of the invention, the sensor of the seventh embodiment is a velocity sensor.
In the base isolation device for a structure according to the eleventh embodiment of the invention, the damping member of any one of the described embodiments is a viscoelastic member or elasto-plastic member.
BRIEF DESCRIPTION OF THE DRAWINGS
FIG. 1 is a front view showing the main parts of a first embodiment of the present invention.
FIG. 2 is a plane view showing the main parts of a first embodiment of the present invention.
FIG. 3 is an enlarged view of the main parts for explaining the operation of a first embodiment of the present invention.
FIG. 4 is a front view showing another embodiment of the present invention.
FIG. 5 is a front view of the main parts of a prior example.
FIG. 6 is a front view showing another embodiment of the present invention.
FIG. 7 is a front view showing another embodiment of the present invention.
FIG. 8A and FIG. 8B are front views showing examples of modifications to the present invention.
FIG. 9 is a plane view showing an example of a modification to the present invention.
FIG. 10 is a front view showing an example of a modification to the present invention.
FIG. 11 is a front view showing an example of a modification to the present invention.
FIG. 12 is a front view showing an example of a modification to the present invention.
FIG. 13A , FIG. 13B and FIG. 13C are front views showing examples of modifications to the present invention.
FIG. 14 is a front view showing an example of a modification to the present invention.
FIG. 15 is a front view showing an example of a modification to the present invention.
FIG. 16 is a front view showing an example of a modification to the present invention.
DESCRIPTION OF THE PREFERRED EMBODIMENTS
A first embodiment of the present invention will be explained below with reference to FIG. 1 to FIG. 3 .
The base isolation device 10 for a structure of this embodiment, which is indicated by the reference number 10 in FIG. 1 , is applied to a floor slab 12 , which is a structural member that is supported by a plurality of bridge supports 11 , and is basically constructed by comprising: support points 13 that are located underneath the floor slab 12 and separated by a specified space (in this embodiment, they are located on adjacent bridge supports 11 ), and where a tension member 14 is placed in between these support points 13 having an overall length that is longer than the space, and where first link pieces 15 are connected to points along the tension member 14 such that they can rotate freely, and second link pieces 16 that are connected between the first link pieces 15 and the floor slab 12 such that they can rotate freely; an energizing member 17 that applies tension to the tension member 14 by energizing the first link pieces 15 and second link pieces 16 between the connections of the first link pieces 15 and second link pieces 16 and the structural member of the structure (floor slab 12 in this embodiment); and a damping member 18 that is operated by the rotation of the first link pieces 15 and second link pieces 16 .
Also, there is an added mass 25 located in the connections 21 between the first link pieces 15 and second link pieces 16 .
To explain these in more detail, in this embodiment, rope is used as the tension member 14 and both ends are fastened to the support points 13 that are located on the bridge supports 11 .
In this embodiment, the first link pieces 15 and second link pieces 16 are located underneath the floor slab 12 , and are located at two places separated by a space midway in the space between adjacent bridge supports 11 in the length direction of the tension member 14 , and one end of each of the first link pieces 15 is connected to the tension member 14 by way of a pin 19 such that it can rotate freely, and one end of each of the second link pieces 16 is connected to the bottom of the floor slab 12 by way of a pin 20 such that it can rotate freely.
Moreover, the other end of each of the first link pieces 15 and second link pieces 16 are connected together by way of a pin 21 such that they can rotate freely, as well as an added mass 25 is added, and furthermore, the first link pieces 15 are formed such that they are shorter than the second link pieces 16 , and the pins 21 of the connections between the first link pieces 15 and second link pieces 16 are located on the inside between both pins 19 of the connections between the first link pieces 15 and the tension members 14 .
Furthermore, in this embodiment, as shown in FIG. 2 , base isolation devices 10 are mounted between a pair of bridge supports 11 that are located such that they are parallel in the plane direction of the floor slab 12 , and the two pins 21 that connect the first link pieces 15 and second link pieces 16 of each base isolation device 10 are shared, and they (pins 21 ) are made sufficiently heavy in order that they can take on the role of the added mass 25 , and a pair of energizing members 17 are located in parallel between these pins 21 , and furthermore a damping member 18 is located between these energizing members 17 and is connected to both pins 21 .
Also, both energizing members 17 are constructed using tension springs, and by energizing both pins 21 in a direction such that they approach each other, and by energizing the pins 19 , which are the connections of each of the first link pieces 15 with the tension members 14 , in a direction such that they become separated from the floor slab 12 , tension is applied to the tension members 14 and keeps the tension members 14 in a state of tension.
Next, the operation of the base isolation device 10 of this embodiment constructed in this way will be explained.
When an earthquake or the like occurs, the floor slab 12 vibrates in the vertical direction, which is the out-of-plane direction of the floor slab 12 , such that the bridge supports 11 are fixed ends, and the middle section bends.
Moreover, as shown in FIG. 3 , when the floor slab 12 bends downward from the normal state as shown by the single-dot dashed line to the state shown by the double-dot dashed line, for example, each of the pins 20 moves downward together with the floor slab 12 , and each of the second link pieces 16 that are connected to the pins 20 receive a force that also similarly moves them downward.
However, by keeping the tension members 14 in a state of tension, the positions of the pins 19 , which are one of the connections with the first link pieces 15 , are restricted, so as the second link pieces 16 move downward as described above, the second link pieces 16 are rotated around the center of the pins 19 .
The direction of rotation of the first link pieces 15 is in a direction such that the pins 21 , which are the connections with the second link pieces 16 , move away from each other, and inertial force acts together with the gravitational force on the added mass 25 connected directly to the pins 21 .
As a result, both of the energizing members 17 located between both pins 21 expand and together with keeping the tension members 14 in a state of tension, the damping member 18 is expanded, and the damping function occurs.
From this, the vertical vibration of the floor slab 12 described above, is converted to motion of the added mass 25 , and due to the occurrence of the damping function, the vertical vibration of the floor slab 12 is suppressed.
On the other hand, as shown in FIG. 3 , when the amount of bending of the floor slab 12 is taken to be X, and the amount of displacement in the horizontal direction of the pin 21 is taken to be βX, by constructing an amplification mechanism with the first link pieces 15 and second link pieces 16 , ‘β>>1’, and as a result, the amount of operation of the damping member 18 increases, and by taking the mass of the added mass 25 to be m′, then that movement is βm′··X, from lever theory, the inertial force acting on the floor slab 12 is β2m′··X, and the added mass 25 has actual motion m′β2, so the mass effect increases.
Also, when the floor slab 12 vibrates upward, movement is in the direction that will do away with the state of tension of the tension members 14 , however, by always having both pins 21 be energized by the energizing members 17 in the direction toward each other, the state of tension in the tension members 14 described above is maintained.
Therefore, the movement of the first link pieces 15 or the damping member 18 is in the opposite direction from the direction described above, and by the same amplification mechanism, the damping effect is increased.
As a result, an effective damping function for vertical vibration, which is the out-of-plane direction of the floor slab 12 , is obtained, and thus it is possible to obtain an elevated isolation function.
The shape and dimensions of the components shown for the embodiment described above are examples, and various modifications are possible based on the design requirements.
For example, in the embodiment described above, an example was given of constructing the tension member 14 with rope, however, instead of this, it is also possible to construct it using a plurality of steel rods 14 a , 14 b , 14 c as shown in FIG. 4 .
Also, an oil damper was shown as an example of the damping member 18 , however, instead of this, it is also possible to use a viscoelastic member or elasto-plastic member.
Also, as shown in FIG. 6 , it is also possible to install connection legs 22 to the tension member 14 , and to connect the ends of the first link pieces 15 to these connection legs 22 by way of pins 19 such that they can rotate freely, and it is also possible to install, for example, weights 23 to the pins 21 to increase the inertial mass of the moving parts of the base isolation device 10 .
Moreover, it is possible to used an active damper for the damping element 18 , and as shown in FIG. 7 , to install a sensor 24 to the floor slab 12 that detects shaking of the floor slab 12 , and further, it is possible to install a controller 25 that adjusts the opening of a variable orifice based on a detection signal from the sensor 24 , and adjust the damping force of the damping member 18 to a proper value by adjusting the opening of the variable orifice with this controller 25 according to the amount of shaking detected by the sensor 24 .
Also, a displacement sensor that detects the amplitude of vibration of the floor slab 12 during vibration, or an acceleration sensor that detects the acceleration of shaking of the floor slab 12 can be used as the sensor 24 .
Besides the example of structural members described above, man-made ground such as that of a footbridge, bridge over railway tracks, multi-level parking structure, or elevated walkway is also feasible.
An example was given in which support points 13 were located on the bridge supports 11 , however, they could also be located on the floor slab 12 , which is the structural member.
This embodiment could also be used as a base isolation device that suppresses the vibration in the out-of-plane direction of the structural members of an inclined roof, or the structural-support members of a vertically standing glass curtain wall.
On the other hand, the connected state of the first link pieces 15 and second link pieces 16 , and tension member 14 , as well as the position of the energizing member 17 and damping member 18 can be changed as appropriate.
For example, as shown in FIG. 8A , construction is also possible in which a rectangular-shaped frame member 26 as shown in FIG. 9 , is placed underneath the floor slab 12 , and this frame member 26 is supported by running tension members 14 between each corner of this frame member 26 and the bridge supports 11 or floor slab 12 , and the end sections of a pair of parallel sides of this frame member 26 and the floor slab 12 are connected by the first link pieces 15 and second link pieces 16 , which are connected such that they can rotate freely, and furthermore, the energizing members 17 and damping members 18 are located between the pins 21 , which make up the connections between the first link pieces 15 and the second link pieces 16 , and the pins 27 , which are located on the parallel sides of the frame member 26 and between the pins 21 . It is also possible to reverse the top and bottom as shown in FIG. 8B .
Here, the pins 21 that connect the first link pieces 15 and second link pieces 16 are located further on the inside of the frame member 26 than the straight lines that connect the pins 19 and pins 20 .
Moreover, the energizing members 17 comprise compression springs, and by energizing both pins 21 with these energizing members 17 in a direction such that they move apart from each other, the frame member 26 is energized downward, and a constant tensile force acts on the tension members 14 .
Furthermore, as shown in FIG. 10 , construction is also possible in which pins 20 are located underneath the floor slab 12 and separated by a set space, the second link pieces 16 are connected to these pins 20 such that they can rotate freely, and the first link pieces 15 are connected to the other end of the second link pieces 16 by way of pins 21 such that they can rotate freely, and furthermore the other ends of the first link pieces 15 are connected to the ends of a connection link piece 28 , which is placed such that it is parallel with the line that connects both pins 20 , by way of pins 19 , the energizing member 17 and damping member 18 are located between the pins 21 , and the tension members 14 running between both ends of the connecting link 28 and the floor slab 12 or bridge supports 11 .
Here, the pins 21 are located further on the outside than the lines that connect the pins 19 and pins 20 , and the energizing member 17 comprises a tension spring, such that by having the energizing member 17 energize the pins 21 in a direction approaching each other, the connection link piece 28 is energized downward and constant tensile force is applied to the tension members 14 .
Also, as shown in FIG. 11 , construction is also possible in which the pins 21 are located further on the inside than the lines that connect the pins 19 and pins 20 , and the energizing member 17 is a compression spring that energizes both pins 21 such that they move apart from each other.
Also, as shown in FIG. 12 , construction is also possible in which the pair of second link pieces 16 shown in the modification of FIG. 10 are connected by one pin 20 , and furthermore, the other ends of the pair of first link pieces 15 , which are connected to the other ends of these second link pieces 16 such that can rotate freely, are connected to the tension member 14 by way of one pin 19 .
Also, a damping member 18 and energizing member 17 are placed between the pins 21 that connect the first link pieces 15 and the second link pieces 16 , and in this example, this energizing member 17 is constructed using a tension spring.
Furthermore, as shown in FIG. 13A , construction is also possible in which the other ends of the pair of first link pieces 15 shown in FIG. 12 are connected on the inside of the pair of second link pieces 16 by pin 19 , which is above both pins 21 , and a downward facing connection rod 29 is connected to this pin 19 , and this connecting rod 29 is connected to the tension member 14 .
Also, as shown in FIG. 13B , the energizing member 17 can be placed between the pin 20 and the pin 19 , or the position of this energizing member 17 and the damping member 18 could be switched.
Also, the tension member 14 can be connected to the first link pieces 15 , 15 as shown in FIG. 13C .
Moreover, as shown in FIG. 14 , construction is possible in which the other ends of the pair of first link pieces 15 shown in FIG. 13 are located further on the outside than the second link pieces 16 , and the other ends of these first link pieces 15 and the tension member 14 are connected by a connection plate 30 shown by the dot dashed line in FIG. 14 such that they can rotate freely.
Furthermore, as shown in FIG. 15 , this embodiment can be applied to a wall structure such as a curtain wall to suppress vibration of the curtain wall or the like. Also, damping members 17 can be installed as shown in FIG. 16 .
In any of these modifications, the same functional effect as the embodiment described above can be obtained.
Furthermore, the case of the floor slab 12 being in a horizontal state was explained, however, the present invention can all be used as a base isolation device for suppressing vibration in the out-of-plane direction of structural members of an inclined roof, or the structural-support members of a vertically standing glass curtain wall.
INDUSTRIAL APPLICABILITY
As explained above, with the base isolation device for a structure of this present invention, by transmitting vibration in the out-of-plane direction of a structure such as a floor slab directly to a damping member, the operation of this damping member is performed, and by magnifying the vibration in the out-of-plane direction of a structural member and transmitting it to the damping member, the amount of operation of this damping member is greatly increased, and it absorbs the energy that accompanies the vibration of the structural member, and thus it is possible to maintain the function of base isolation of the structural member. | A base isolation device for a structure capable of efficiently and effectively suppressing the vibration of a structural body in surface outside direction, wherein a tension member having on overall length longer than an interval between support points provided on the structural body at a specified interval is disposed between the support points, one end parts of first link pieces are rotatably connected midway to the tension member directly or through rigid members, one end parts of second link pieces are rotatably connected to the structural body, the other end parts of the first link pieces are rotatably connected to the other end parts of the second link pieces, and an energizing member providing a tension to the tension member by energizing the first link piece and the second link piece and a damping member operated by the rotation of the first link piece and the second link piece are installed between the structural body forming the structure and connection parts between the first link pieces and the second link pieces. | 4 |
BACKGROUND OF THE INVENTION
[0001] 1. Technical Field
[0002] The present invention relates in general to an improved architecture for conditioning flow inside data storage devices and, in particular, to an improved system, method, and apparatus for applying boundary layer manipulation techniques to the air flow inside rotary disk storage devices.
[0003] 2. Description of the Related Art
[0004] Data access and storage systems generally comprise one or more storage devices that store data on magnetic or optical storage media. For example, a magnetic storage device is known as a direct access storage device (DASD) or a hard disk drive (HDD) and includes one or more disks and a disk controller to manage local operations concerning the disks. The hard disks themselves are usually made of aluminum alloy or a mixture of glass and ceramic, and are covered with a magnetic coating. Typically, one to five disks are stacked vertically on a common spindle that is turned by a disk drive motor at several thousand revolutions per minute (rpm). Hard disk drives have several different typical standard sizes or formats, including server, desktop, mobile (2.5 and 1.8 inches) and micro drive.
[0005] A typical HDD also uses an actuator assembly to move magnetic read/write heads to the desired location on the rotating disk so as to write information to or read data from that location. Within most HDDs, the magnetic read/write head is mounted on a slider. A slider generally serves to mechanically support the head and any electrical connections between the head and the rest of the disk drive system. The slider is aerodynamically shaped to glide over moving air in order to maintain a uniform distance from the surface of the rotating disk, thereby preventing the head from undesirably contacting the disk.
[0006] The head and arm assembly is linearly or pivotally moved utilizing a magnet/coil structure that is often called a voice coil motor (VCM). The stator of a VCM is mounted to a base plate or casting on which the spindle is also mounted. The base casting with its spindle, actuator VCM, and internal filtration system is then enclosed with a cover and seal assembly to ensure that no contaminants can enter and adversely affect the reliability of the slider flying over the disk. When current is fed to the motor, the VCM develops force or torque that is substantially proportional to the applied current. The arm acceleration is therefore substantially proportional to the magnitude of the current. As the read/write head approaches a desired track, a reverse polarity signal is applied to the actuator, causing the signal to act as a brake, and ideally causing the read/write head to stop and settle directly over the desired track.
[0007] One of the major hurdles in hard disk drive (HDD) development is track misregistration (TMR). TMR is the term used for measuring data errors while a HDD writes data to and reads data from the disks. One of the major contributors to TMR is flow-induced vibration. Flow-induced vibration is caused by turbulent flow within the HDD. The nature of the flow inside a HDD is characterized by the Reynolds number, which is defined as the product of a characteristic speed in the drive (such as the speed at the outer diameter of the disk), and a characteristic dimension (such as the disk diameter or, for some purposes, disk spacing). In general, the higher the Reynolds number, the greater the propensity of the flow to be turbulent.
[0008] Due to the high rotational speed of the disks and the complex geometries of the HDD components, the flow pattern inside a HDD is inherently unstable and non-uniform in space and time. The combination of flow fluctuations and component vibrations are commonly referred to as “flutter” in the HDD literature. The more precise terms “disk flutter” and “arm flutter” refer to buffeting of the disk and arm, respectively, by the air flow. Unlike true flutter, the effect of the vibrations in HDDs on the flow field is usually negligible. Even small arm and disk vibrations (at sufficiently large frequencies, e.g., 10 kHz and higher), challenge the ability of the HDD servo system to precisely follow a track on the disk.
[0009] Since the forcing function of vibrations is directly related to flow fluctuations, it is highly desirable to reduce any fluctuating variation in the flow structures of air between both co-rotating disks and single rotating disks. Thus, a system, method, and apparatus for improving the architecture for conditioning air flow inside data storage devices is needed.
SUMMARY OF THE INVENTION
[0010] One embodiment of a system, method, and apparatus of the present invention attempts to apply several techniques to solve track misregistration (TMR) problems in hard disk drives (HDD). Boundary layer manipulation techniques are applied to the airflow in the HDD, such as boundary layer suction with slots or holes, and wall damping techniques, such as an open honeycomb seal and Helmholtz resonators.
[0011] The flow-conditioning solutions presented in the present application reduce the turbulence intensity throughout the HDD to reduce TMR. These solutions achieve these goals while minimizing increases in the running torque needed to overcome their inherent rotational drag. One solution affects the stability of the HDD flow and enables the flow to follow complex geometries and regions with adverse pressure gradients (i.e., increasing pressure in the direction of flow) without flow separation. Separated regions are a major source of flow fluctuations when the Reynolds number is sufficiently large. The latter is true for typical prior art HDD configurations. Suction inhibits turbulent mixing between the Ekman layers spun off the disk and their return flow. Reduced mixing leads to a reduction in the aerodynamic torque needed to spin the disk pack.
[0012] For example, the head disk assembly (HDA) wall may be fitted with arrays of suction holes or slots or a combination of the two. Air from the wall boundary layer is sucked through the holes and slots into a suction plenum. The suction air is reintroduced into the file at a suitable location such as at the hub perforations. Hub ventilation reduces flow-induced TMR, even without wall suction. The suction air also may be passed through an HDA air filter before being reintroduced into the disk pack.
[0013] Yet another solution damps turbulent fluctuations via the dissipation generated inside special linings, such as a multitude of micro cavities. For example, a damped wall can take the form of a honeycomb lining. Alternatively, the wall can form a close-packed array of Helmholtz resonators, which are essentially walled cavities with a small orifice. Because these resonators can be tuned, they are particularly effective in suppressing narrow-band fluctuations.
[0014] The application of these special linings along the interior walls of the HDD provide aerodynamic and acoustic damping. Suitable linings promote viscous dissipation of the fluctuations, and may take forms such as closed and open cell acoustic foam, and arrays of tuned cavities, as described above. In particular, the Helmholtz resonators may be tuned to act as acoustic notch filters or certain prominent frequencies in the file. For example, one such frequency is the vortex shedding frequency associated with the actuator arm.
[0015] The foregoing and other objects and advantages of the present invention will be apparent to those skilled in the art, in view of the following detailed description of the present invention, taken in conjunction with the appended claims and the accompanying drawings.
BRIEF DESCRIPTION OF THE DRAWINGS
[0016] So that the manner in which the features and advantages of the invention, as well as others which will become apparent are attained and can be understood in more detail, more particular description of the invention briefly summarized above may be had by reference to the embodiment thereof which is illustrated in the appended drawings, which drawings form a part of this specification. It is to be noted, however, that the drawings illustrate only an embodiment of the invention and therefore are not to be considered limiting of its scope as the invention may admit to other equally effective embodiments.
[0017] FIG. 1 is a top plan view of one embodiment of a disk drive constructed in accordance with the present invention.
[0018] FIG. 2 is a top plan view of another embodiment of a disk drive constructed in accordance with the present invention.
[0019] FIG. 3 is a sectional side view of one embodiment of an interleaf structure taken along the line 3 - 3 of FIG. 2 .
[0020] FIG. 4 is a sectional side view of an alternate embodiment of the interleaf structure of FIG. 3 .
[0021] FIG. 5 is a sectional side view of another alternate embodiment of the interleaf structure of FIG. 3 .
[0022] FIG. 6 is a sectional side view of yet another alternate embodiment of the interleaf structure of FIG. 3 .
[0023] FIG. 7 is a sectional side view of still another alternate embodiment of the interleaf structure of FIG. 3 .
[0024] FIG. 8 is a partial isometric view of one embodiment of a boundary layer device for a disk drive enclosure.
[0025] FIG. 9 is a partial isometric view of an alternate embodiment of the boundary layer device of FIG. 8 .
DETAILED DESCRIPTION OF THE INVENTION
[0026] Referring to FIG. 1 , one embodiment of a system, method, and apparatus for reducing track misregistration in disk drives is shown. This embodiment employs an information storage system comprising a magnetic hard disk file or drive 111 for a computer system. Drive 111 has an outer housing or base 113 (e.g., an enclosure) containing at least one magnetic disk 115 . Disk 115 is rotated by a spindle motor assembly having a central drive hub 117 . An actuator 121 comprises a plurality of parallel actuator arms 125 (one shown) in the form of a comb that is pivotally mounted to base 113 about a pivot assembly 123 . A controller 119 is also mounted to base 113 for selectively moving the comb of arms 125 relative to disk 115 .
[0027] In the embodiment shown, each arm 125 has extending from it at least one cantilevered load beam and suspension 127 . A magnetic read/write transducer or head is mounted on a slider 129 and secured to a flexure that is flexibly mounted to each suspension 127 . The read/write heads magnetically read data from and/or magnetically write data to disk 115 . The level of integration called the head gimbal assembly is head and the slider 129 , which are mounted on suspension 127 . The slider 129 is usually bonded to the end of suspension 127 .
[0028] Suspensions 127 have a spring-like quality, which biases or urges the air bearing surface of the slider 129 against the disk 115 to enable the creation of the air bearing film between the slider 129 and disk surface. A voice coil 133 housed within a conventional voice coil motor magnet assembly is also mounted to arms 125 opposite the head gimbal assemblies. Movement of the actuator 121 (indicated by arrow 135 ) by controller 119 moves the head gimbal assemblies radially across tracks on the disk 115 until the heads settle on their respective target tracks. The head gimbal assemblies operate in a conventional manner and always move in unison with one another, unless drive 111 uses multiple independent actuators (not shown) wherein the arms can move independently of one another.
[0029] Referring now to FIGS. 1 and 2 , drive 111 further comprises a flow-conditioning device 141 that is mounted to the enclosure 113 adjacent to the disk 115 . The flow-conditioning device 141 comprises one or more “flow straighteners” that may be either symmetrically arrayed or asymmetrically about the disk 115 , depending upon the application. FIG. 2 illustrates the symmetrical arrangement. Each flow-conditioning device 141 comprises a foundation or support post 145 that is mounted to the enclosure 113 . As shown in FIG. 3 , one embodiment of support post 145 is mounted to and extends between both portions of the enclosure 113 : base plate 113 a and top cover 113 b.
[0030] The flow-conditioning device 141 includes at least one projection or finger 143 (e.g., five shown for four disks 115 in FIG. 3 ) having passages 147 . The fingers 143 extend radially with respect to the disks 115 and their axis 116 , and parallel to the surface 118 of the disks 115 . When two or more fingers 143 are used, the adjacent fingers 143 define a slot 144 that closely receives the two parallel surfaces of the disk 115 . The fingers 143 originate at the support post 145 and preferably extend to or near the disk hub 117 . However, there is no contact between any portion of the flow-conditioning device 141 and the disks 115 .
[0031] Each finger 143 comprises a small, generally rectangular frame having a plurality of the passages 147 that permit air flow to move all the way through the finger 143 . The passages 147 are formed in the finger 143 in directions that are axially and radially transverse (e.g., perpendicular) with respect to the disks 115 . Each of the fingers 143 has the passages 147 to reduce air flow turbulence intensity and track misregistration.
[0032] The fingers 143 are positioned in the air flow stream generated by the disks 115 so that, as the disks 115 rotate, the passages 147 are aligned with the air flow stream and reduce an air flow turbulence intensity and track misregistration between the heads on the sliders 129 and the read/write tracks on the disks 115 . The turbulent energy generated by the flow-conditioning device(s) 141 is confined to a range of smaller eddies that are more easily dissipated within the disk drive 111 than prior art large eddies. Each finger 143 has an angular or arcuate width in a range of approximately 5 degrees or less. Each finger 143 also can be configured to have a constant width along the radial direction of the disk 115 .
[0033] As shown in FIGS. 3-7 , the passages 147 may comprise many different configurations or combinations thereof. For example, in FIG. 3 , the passages 147 are configured in a honeycomb structure 151 having a tight array of one or more hexagonal feature(s) that extend across the entire face of the fingers 143 . In one embodiment, the passages 147 (honeycomb cell size) are on the order of five times smaller than the axial disk spacing. In addition, the fingers 143 may have an arcuate width that is approximately equal to said axial distance minus a mechanical clearance on the order of 0.5 mm.
[0034] In another embodiment ( FIG. 4 ), the passages are formed from wire screen walls 153 , which may be woven, mounted on a framing structure. The wire screen dimensions are dictated by the size of the disk diameter and spacing. Typically, the wire screen walls 153 comprise at least two or three passages across the vertical direction. In one version, the wire screen walls 153 have a thickness on the order of 0.1 mm.
[0035] In FIG. 5 , the passages comprise sets of guide vanes 155 that extend axially with respect to the disk 115 . In the embodiment shown, the guide vanes 155 are grouped in small sets of three that radially offset from each other. The individual vanes in guide vanes 155 are parallel to each other. Other guide vane configurations are possible, including those of the slanted type. The guide vanes have a thickness that is sufficient to ensure mechanical stability and ruggedness, which may be on the order of 0.3 mm.
[0036] Alternatively, the passages may be formed by cylindrical tubes 157 , as shown in FIG. 6 . The cylindrical tubes 157 may comprise many different configurations, such as side-by-side in a flat array having a single row of the axially parallel cylindrical tubes 157 . In another embodiment ( FIG. 7 ), the cylindrical tubes 159 form a plurality (two shown) of parallel rows that are configured in an alternating pattern of upper and lower positions.
[0037] Referring now to FIG. 8 , an inner wall of the enclosure 113 may be configured with a boundary layer device 161 . The boundary layer device 161 is designed to manipulate the air flow inside the disk drive 111 to provide aerodynamic and acoustic damping that promote viscous dissipation of turbulent fluctuations.
[0038] The boundary layer device may comprise many different forms. For example, in FIG. 8 , a suction plenum 163 having an array of suction apertures 165 is shown. The apertures 165 may comprise slots, holes, and/or combinations thereof, and are used to evacuate air flow from the interior of the disk drive 111 into the suction plenum 163 . The air flow (see arrows 167 ) is then reintroduced into the interior of the disk drive 111 at a suitable location, such as at perforations 169 in hub 117 (for clarity, disks 115 are not shown). Moreover, the suction air also may be passed through an air filter 171 before being reintroduced into the pack of disks 115 .
[0039] An alternative embodiment of the boundary layer device is shown in FIG. 9 as a lining of cavities 173 on the inner wall of enclosure 113 . In one version, the cavities 173 comprise a honeycomb of hexagonal walls 175 , each of which is perforated by a small orifice 177 . Collectively, these cavities 173 form a close-packed array of Helmholtz resonators. Because these resonators can be tuned, they are particularly effective in suppressing narrow-band turbulence fluctuations. In particular, the Helmholtz resonators may be tuned to act as acoustic notch filters or certain prominent frequencies in the file. For example, one such frequency is the vortex shedding frequency associated with the actuator arm. In addition, the cavities may comprise closed and open cell acoustic foam.
[0040] The present invention also comprises a method of reducing track misregistration in a disk drive. In one embodiment ( FIG. 1 ), the method comprises providing a disk drive 111 having an enclosure 113 , a disk 115 having a surface 118 with tracks, and an actuator 121 having a head for reading from and writing to the tracks. The method further comprises positioning a flow-conditioning device 141 ( FIG. 3 ) adjacent to the surface 118 of the disk 115 , rotating the disk 115 to generate an air flow, flowing the air flow through passages 147 in the flow-conditioning device 141 , and thereby reducing air flow turbulence intensity and track misregistration between the head and the tracks on the disk 115 .
[0041] The method also may comprise positioning the disk 115 in an elongated slot 144 in the flow-conditioning device 141 . The method may further comprise orienting the passages 147 at axially and radially transverse positions with respect to the disk 115 , and forming the passages in a configuration selected from the group consisting of: a honeycomb structure ( FIG. 3 ), wire screen walls ( FIG. 4 ), guide vanes ( FIG. 5 ), and cylindrical tubes ( FIGS. 6 and 7 ). In another embodiment, the method may further comprise forming a symmetrical array ( FIG. 2 ) of the flow-conditioning devices 141 about the disk 115 .
[0042] Alternatively, or in combination with any of the foregoing steps of the method, the method may further comprise forming a boundary layer device 161 ( FIGS. 8 and 9 ) on an inner surface of the enclosure 113 , and manipulating the air flow inside the disk drive 111 with the boundary layer device 161 to provide aerodynamic and acoustic damping that promote viscous dissipation of turbulent fluctuations. The method may comprise evacuating air flow from an interior of the disk drive 111 into a suction plenum 163 ( FIG. 8 ), and reintroducing the air flow into the disk drive 111 . In addition, the method may comprise configuring the boundary layer device as a lining of walled cavities 173 ( FIG. 9 ), each having a small orifice 177 in communication with the interior of the disk drive 111 .
[0043] The present invention has several advantages, including the ability to reduce TMR problems in hard disk drives HDDs. These solutions break up large-scale eddies, straighten air flows, and manipulate the boundary layers. As a result, the turbulence intensity is reduced throughout the HDD to reduce TMR while minimizing increases in the running torque needed to overcome rotational drag. The turbulent energy generated by the devices is confined to a range of smaller eddies that are more easily dissipated. The LEBU devices can be used individually or as multiple units in series.
[0044] The present invention also enables the flow to follow complex geometries without flow separation. Suction inhibits turbulent mixing between the Ekman layers spun off the disk and their return flow. Reduced mixing leads to a reduction in the aerodynamic torque needed to spin the disk pack. In addition, turbulent fluctuations are dampened via the dissipation generated by the special linings, some of which can be tuned to suppress narrow-band fluctuations. The application of these special linings along the interior walls of the HDD provide aerodynamic and acoustic damping. In particular, the Helmholtz resonators may be tuned to act as acoustic notch filters or certain prominent frequencies in the file.
[0045] While the invention has been shown or described in only some 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. | A system, method, and apparatus for solving flow-induced track misregistration (TMR) problems in hard disk drives (HDD). Boundary layer manipulation techniques are applied to the airflow in the HDD, such as boundary layer suction with slots or holes, and wall damping techniques, such as an open honeycomb seal and Helmholtz resonators. These flow-conditioning solutions reduce the turbulence intensity throughout the HDD to reduce TMR. These solutions achieve these goals while minimizing increases in the running torque needed to overcome their inherent rotational drag. | 6 |
BACKGROUND
1. Technical Field
The present invention relates generally to device interfacing; and, more particularly, it relates to interfacing a single ended device to a device employing differential inputs.
2. Related Art
There is a movement in the art towards devices that use or require differential inputs. There have been some conventional approaches that have sought to perform the interfacing of a single ended signal to a device necessitating differential inputs. One conventional approach seeks to isolate signals. This is done by separating traces on a printed circuit board (PCB) and by providing extra ground paths through connectors or in and out of integrated circuit (IC) packages. One deficiency in this approach is that isolating these signals does not eliminate shared paths altogether. Cross-talk between the signals is reduced, but it may not be completely eliminated.
Another conventional approach uses a differential driver that provides source and return connections for every signal. This second conventional approach allows cross-talk problems to be somewhat minimized, since each signal has its own dedicated return path. However, using these differential drivers necessitates special devices and more pins within a system, thereby increasing real estate consumption, cost, and complexity within a system. In certain applications where these constraints are rigid, the incremental addition of cost and complexity may make it impracticable to use such a conventional solution. The use of these differential drivers requires the use of other special devices more pins to perform the proper interfacing. This conventional approach is exemplary of a brute force method that puts little emphasis on cost savings in any number of terms including: money, real estate, and complexity.
Further limitations and disadvantages of conventional and traditional systems will become apparent to one of skill in the art through comparison of such systems with the present invention as set forth in the remainder of the present application with reference to the drawings.
SUMMARY OF THE INVENTION
Various aspects of the present invention can be found in a single to differential interface. The single to differential interface includes a first isolated power and ground plane and a second isolated power and ground plane. The first isolated power and ground plane generates a single ended source output having a first current magnitude. The second isolated power and ground plane is communicatively coupled to the first isolated power and ground plane via a substantially transmission-like connection. The second isolated power and ground plane receives a pair of differential signals. The first isolated power and ground plane receives a return signal via a single return path, the return signal having a second current magnitude.
In certain embodiments of the invention, the substantially transmission-like connection includes a number of transmission lines. One of the transmission lines has a first characteristic impedance and at least one other of the transmission lines has a second characteristic impedance. The first current magnitude and the second current magnitude are substantially of a common magnitude. The substantially transmission-like connection includes a number of connection types including a trace on a printed circuit board. The substantially transmission-like connection is operable across a predetermined frequency range at which the single ended source output is operable to be modulated. The predetermined frequency range spans from DC to a maximum switching frequency. One of the differential signals of the pair of differential signals is referenced through a resistance to a voltage logic level.
Other aspects of the present invention can be found in a single to differential interface. The single to differential interface includes a single ended source, a single to differential interface circuitry, and a differential receiver. The single ended source emits a single ended source output. The single to differential interface circuitry is operable to convert the single ended source output to a pair of differential outputs. The differential receiver receives the pair of differential outputs. The single to differential interface circuitry employs a substantially transmission-like connection between the single ended source and the differential receiver.
In certain embodiments of the invention, the substantially transmission-like connection includes a number of connection types including a trace on a printed circuit board. The differential receiver includes a printed circuit board trace having a first characteristic impedance, and the substantially transmission-like connection includes an interface trace having a second characteristic impedance. The second characteristic impedance is larger than the first characteristic impedance. One of the differential outputs of the pair of differential outputs is referenced through a resistance to a voltage logic level. The single to differential interface also includes a floating power supply that biases the single ended source. In other embodiments, a current being transmitted from the single ended source includes a magnitude that is substantially equal to a magnitude of a current that is received by the single ended source.
Other aspects of the present invention can be found in a single to differential interface method. The method includes referencing a single ended source output signal to a floating single ended source ground, implementing a differential interface that is referenced to a system ground, and referencing a number of differential signals to a number of receiver power supply voltages.
In certain embodiments of the invention, one of the differential signals is referenced to one of a voltage logic level low or a voltage logic level high. The method also includes using uniform impedance control, and the uniform impedance control is operable to ensure a single return current path. The method also includes connecting a first isolated power and ground plane to a second isolated power and ground plane via a substantially transmission-like connection. The substantially transmission-like connection includes a number of connection types including an interface trace on a printed circuit board.
Other aspects, advantages and novel features of the present invention will become apparent from the following detailed description of the invention when considered in conjunction with the accompanying drawings.
BRIEF DESCRIPTION OF THE DRAWINGS
A better understanding of the present invention can be obtained when the following detailed description of various exemplary embodiments are considered in conjunction with the following drawings.
FIG. 1 is a system diagram illustrating an embodiment of a single to differential interface built in accordance with the present invention.
FIG. 2 is a system diagram illustrating an embodiment of a single to differential clock interface built in accordance with the present invention.
FIG. 3 is a system diagram illustrating an embodiment of a single to differential interface via transmission lines built in accordance with the present invention.
FIG. 4 is a system diagram illustrating another embodiment of a single to differential interface via transmission lines built in accordance with the present invention.
FIG. 5 is a system diagram illustrating an embodiment of a single to differential interface on a printed circuit board built in accordance with the present invention.
FIG. 6 is a system diagram illustrating another embodiment of a single to differential interface on a printed circuit board built in accordance with the present invention.
FIG. 7 is a functional block diagram illustrating an embodiment of a single to differential interface method performed in accordance with the present invention.
FIG. 8 is a functional block diagram illustrating another embodiment of a single to differential interface method performed in accordance with the present invention.
FIG. 9 is a functional block diagram illustrating another embodiment of a single to differential interface method performed in accordance with the present invention.
DETAILED DESCRIPTION OF THE INVENTION
The present invention is operable to convert a driving source from a single ended signal to differential signals. By running signals in a differential mode, shared path effects are eliminated. Some of the benefits of this differential mode are reduced system noise, and improved transmission and detection of signals. Differential signals may be produced from conventional, non-differential devices. The ability to perform this transformation without isolating signals and without the use of a differential driver results in cost savings and accessibility among other benefits. The use of differential signals generated by the present invention offers many other benefits as well. The parasitic effects from connectors and integrated circuit (IC) packages often induce signal distortion that creates timing “push out and cross talk problems. The use of differential signals, as generated by the present invention, will reduce these effects and improve overall system performance.
FIG. 1 is a system diagram illustrating an embodiment of a single to differential interface 100 built in accordance with the present invention. A single ended source circuitry 110 provides a single ended source output 121 to a single to differential interface circuitry 130 . The single to differential interface circuitry 130 generates two differential signals from the single ended source output 121 , namely, a differential output # 1 141 and a differential output # 2 142 . A differential receiver circuitry 150 receives both of the differential output # 1 141 and the differential output # 2 142 . A single output, a differential receiver circuitry output 161 , is transmitted from the differential receiver circuitry 150 to any other device. The single to differential interface 100 of the FIG. 1 may be used to perform the transformation of a single ended signal to differential signals to be provided to any number of devices requiring differential inputs.
FIG. 2 is a system diagram illustrating an embodiment of a single to differential clock interface 200 built in accordance with the present invention. A single ended clock circuitry 210 provides a single ended clock output 221 to a single to differential clock interface circuitry 230 . The single to differential clock interface circuitry 230 generates two differential signals from the single ended source output 221 , namely, a differential clock output # 1 241 and a differential clock output # 2 242 . A differential clock receiver circuitry 250 receives both of the differential clock output # 1 241 and the differential clock output # 2 242 . A single output, a differential clock receiver circuitry output 261 , is transmitted from the differential clock receiver circuitry 250 to any other device. The single to differential clock interface 200 of the FIG. 2 may be used to perform the transformation of a single ended clock signal to differential clock signals to be provided to any number of devices requiring differential inputs.
FIG. 3 is a system diagram illustrating an embodiment of a single to differential interface via transmission lines 300 built in accordance with the present invention. A gain 320 , biased using a floating DC source, is provided a signal from a source 310 . The output from the gain 320 is fed to the transmit path of a transmission line 331 having a characteristic impedance Z TL1 . In certain embodiments of the invention, the transmission line 331 is exemplary of any type of connection having a substantially transmission-like connection. As will be seen below in other embodiments of the invention, a substantially transmission-like connection is implemented in other forms included traces on a printed circuit board (PCB). The return path of the near end of the transmission line 331 is passed back to the floating low end voltage level of the DC source that biases the gain 320 .
The transmit path of the far end of the transmission line 331 feeds a near end of a transmission line 332 having a characteristic impedance Z TL2 . The return paths of both the near end and the far end of the transmission line 332 are grounded to the system ground of the single to differential interface via transmission lines 300 . The signal transmitted from the far end of the transmission line 332 is passed to one of the inputs of a gain 350 . For example, the transmit signal through the transmission line 332 passed to the negative input of the gain 350 . This signal is referenced through a resistance R LL 342 to a voltage level logic low V LL . The gain 350 is biased using a voltage level V DD and is referenced to the system ground of the single to differential interface via transmission lines 300 .
The other of the inputs of the gain 350 is connected to the far end of a transmission line 333 having a characteristic impedance Z TL3 . For example, the signal fed back through the transmission line 333 is from the positive input of the gain 350 . This signal is referenced through a resistance R LH 343 to a voltage level logic high V LH . The transmit path from the near end of the transmission line 333 is passed to the return path of the far end of the transmission line 331 . The return paths of both the near end and the far end of the transmission line 333 are grounded to the system ground of the single to differential interface via transmission lines 300 .
There are certain areas within the single to differential interface via transmission lines 300 where the currents are all equal to a value “I.” For example, the current transmitted from the gain 320 to the transmit path of the near end of the transmission line 33 , and the current received from the receive path of the near end of the transmission line 331 are both equal to the value “I.” In addition, the values of the current transmitted through the resistance R LL 342 to the voltage level logic low V LL and the current transmitted from the voltage level logic high V LH the resistance R LH 343 are also equal to the value “I.” These currents are of a common magnitude, or of a substantially similar magnitude. The design of the present invention, as shown in the embodiment of the FIG. 3, also ensures that there are no current return paths except through the various transmission lines. The particular values of the characteristic impedances of the transmission lines and the various resistors within the FIG. 3 are variable as required within various applications. One example of particular values that will provide the advantages contained within the present invention is shown below in FIG. 4 .
FIG. 4 is a system diagram illustrating another embodiment of a single to differential interface via transmission lines built in accordance with the present invention. A gain 420 , biased using a floating DC source, is provided a signal from a source 410 . The output from the gain 420 is fed to the transmit path of a transmission line 431 having a characteristic impedance Z TL1 that is equal to 100Ω. In certain embodiments of the invention, the transmission line 431 is exemplary of any type of connection having a substantially transmission-like connection. As will be seen below in other embodiments of the invention, a substantially transmission-like connection is implemented in other forms included traces on a printed circuit board (PCB). The return path of the near end of the transmission line 431 is passed back to the floating low end voltage level of the DC source that biases the gain 420 .
The transmit path of the far end of the transmission line 431 feeds a near end of a transmission line 432 having a characteristic impedance Z TL2 that is equal to 50Ω. The return paths of both the near end and the far end of the transmission line 432 are grounded to the system ground of the single to differential interface via transmission lines 400 . The signal transmitted from the far end of the transmission line 432 is passed to one of the inputs of a gain 450 . For example, the transmit signal through the transmission line 432 passed to the negative input of the gain 450 . This signal is referenced through a resistance R LL 442 that is equal to 50Ω to a voltage level logic low V LL . The gain 450 is biased using a voltage level V DD and is referenced to the system ground of the single to differential interface via transmission lines 400 .
The other of the inputs of the gain 450 is connected to the far end of a transmission line 433 having a characteristic impedance Z TL3 that is equal to 50Ω. For example, the signal fed back through the transmission line 433 is from the positive input of the gain 450 . This signal is referenced through a resistance R LH 443 that is equal to 50Ω to a voltage level logic high V LH . The transmit path from the near end of the transmission line 433 is passed to the return path of the far end of the transmission line 431 . The return paths of both the near end and the far end of the transmission line 433 are grounded to the system ground of the single to differential interface via transmission lines 400 .
As within the system shown in the FIG. 3, there are certain areas within the single to differential interface via transmission lines 400 where the currents are all equal to a value “I.” For example, the current transmitted from the gain 420 to the transmit path of the near end of the transmission line 43 , and the current received from the receive path of the near end of the transmission line 431 are both equal to the value “I.” In addition, the values of the current transmitted through the resistance R LL 442 to the voltage level logic low V LL and the current transmitted from the voltage level logic high V LH the resistance R LH 443 are also equal to the value “I.” These currents are of a common magnitude, or of a substantially similar magnitude. The value of “I” in the FIG. 3 is not necessarily the same as the value of “I” as shown in the FIG. 4 . The design of the present invention, as shown in the embodiment of the FIG. 4, also ensures that there are no current return paths except through the various transmission lines.
FIG. 5 is a system diagram illustrating an embodiment of a single to differential interface on a printed circuit board 500 built in accordance with the present invention. The differential interface on a printed circuit board 500 employs at least two independent isolated power and ground planes. An isolated power and ground plane # 1 511 and an isolated power and ground plane # 2 522 are both contained within a system that is placed on a printed circuit board. The isolated power and ground plane # 1 511 includes a gain 530 that is biased using a floating DC source that is referenced to a common ground on the isolated power and ground plane # 1 511 . An input, also referenced to the common ground of the isolated power and ground plane # 1 511 , is provided to the gain 530 . The output of the gain 530 is passed to a printed circuit board (PCB) trace that is placed above the ground plane of the entire PCB. This trace may be viewed as being an interface trace from certain perspectives. In certain embodiments of the invention, this interface trace is exemplary of any type of connection having a substantially transmission-like connection.
This interface trace is passed to a trace that is on the isolated power and ground plane # 2 522 . This trace on board the isolated power and ground plane # 2 522 feeds to the negative input of a gain 550 , that is referenced through a resistance R LL 541 to a voltage level logic low V LL . The gain 550 is biased using a voltage level V DD and is referenced to the system ground of the single to differential interface on a printed circuit board 500 . The negative input to the gain 550 is referenced through a resistance R LH 542 to a voltage level logic high V LH . In addition, the negative input to the gain 550 is fed to a trace on board the isolated power and ground plane # 2 522 that is itself connected to another interface trace on the PCB that connects to the isolated power and ground plane # 1 511 . The receiving end of this interface trace, on the isolated power and ground plane # 1 511 , is connected to the common ground of the isolated power and ground plane # 1 511 as well. The interface traces that connect the two isolated power and ground planes 511 and 522 each have a characteristic impedance (Z I/F ) that is greater than the characteristic impedance of the printed circuit board (Z PCB ) itself. From certain perspectives, these interface traces that connect the two isolated power and ground planes 511 and 522 are differentiated from the generic traces placed on the PCB.
The design of the present invention, as shown in the embodiment of the FIG. 5, also ensures that there are no current return paths except through the various traces that interconnect the two isolated power and ground planes 511 and 522 . The particular values of the characteristic impedances of the various traces and the resistors within the FIG. 5 are variable as required within different applications. One example of particular values that will provide the advantages contained within the present invention is shown below in FIG. 6 .
FIG. 6 is a system diagram illustrating another embodiment of a single to differential interface on a printed circuit board 600 built in accordance with the present invention. The differential interface on a printed circuit board 600 employs at least two independent isolated power and ground planes. An isolated power and ground plane # 1 611 and an isolated power and ground plane # 2 622 are both contained within a system that is placed on a printed circuit board. The isolated power and ground plane # 1 611 includes a gain 630 that is biased using a floating DC source that is referenced to a common ground on the isolated power and ground plane # 1 611 . An input, also referenced to the common ground of the isolated power and ground plane # 1 611 , is provided to the gain 630 . The output of the gain 630 is passed to the isolated power and ground plane # 2 622 via an interface trace between the two isolated power and ground planes 611 and 622 that has a characteristic impedance equal to 100Ω. This trace may be viewed as being an interface trace from certain perspectives. In certain embodiments of the invention, this interface trace is exemplary of any type of connection having a substantially transmission-like connection.
This 100Ω interface trace is connected to a trace on the isolated power and ground plane # 2 622 that has a characteristic impedance equal to 50Ω. This trace 50Ω on board the isolated power and ground plane # 2 622 feeds to the negative input of a gain 650 , that is referenced through a resistance R LL 641 , having a value of 50Ω, to a voltage level logic low V LL . The gain 650 is biased using a voltage level V DD and is referenced to the system ground of the single to differential interface on a printed circuit board 600 . The negative input to the gain 650 is referenced through a resistance R LH 642 , having a value of 50Ω, to a voltage level logic high V LH . In addition, the negative input to the gain 650 is fed to a trace on board the isolated power and ground plane # 2 622 that has a characteristic impedance equal to 50Ω. The 50Ω trace in the isolated power and ground plane # 2 622 is connected to another interface trace having a characteristic impedance of 100Ω interface trace that interconnects the two isolated power and ground planes 611 and 622 .
The receiving end of the 100Ω interface trace, on the isolated power and ground plane # 1 611 , is connected to the common ground of the isolated power and ground plane # 1 611 as well. The interface traces that connect the two isolated power and ground planes 611 and 622 each have a characteristic impedance (Z I/F ) of 100Ω that is greater than the characteristic impedance of the printed circuit board (Z PCB ) itself that is 50Ω. From certain perspectives, these interface traces that connect the two isolated power and ground planes 611 and 622 are differentiated from the generic traces placed on the PCB, at least in that their characteristic impedances are differentiated from the generic values of characteristic impedances on the PCB.
Again, the design of the present invention, as shown in the embodiment of the FIG. 6, also ensures that there are no current return paths except through the various interface traces that interconnect the two isolated power and ground planes 611 and 622 .
FIG. 7 is a functional block diagram illustrating an embodiment of a single to differential interface method 700 performed in accordance with the present invention. In a block 710 , a single ended source output is received. Then, in a block 720 , the single ended source output is transformed to differential input signals. Finally, in a block 730 , the differential signals are passed to a differential receiver.
The single to differential interface method 700 is operable generically to perform the transformation of the single ended source output to differential signals that are operable to be used as inputs to a differential receiver. The present invention allows for this transformation without necessitating the use of a differential driver or any additional devices or pins to perform the transformation. The present invention offers a very compressed and efficient solution to perform this transformation.
FIG. 8 is a functional block diagram illustrating another embodiment of a single to differential interface method 800 performed in accordance with the present invention. In a block 810 , a power supply is floated at a singled ended source. Then in a block 820 , a differential interface referenced to a system ground is implemented. If desired in alternative embodiments, the differential signals are referenced to receiver power supply voltages as shown in an alternative block 822 . Finally, in a block 830 , the differential signals are used to drive a differential receiver.
The single to differential interface method 800 shows how a floating power supply may be implemented to assist in the transformation of a single ended source output to differential signals. In addition, if desired in alternative embodiments, the differential signals themselves are not referenced to either a common ground of the single ended source or to a system ground of a system employing the single to differential interface method 800 . The differential signals may be referenced to voltages of a power supply that is used to bias the differential receiver.
FIG. 9 is a functional block diagram illustrating another embodiment of a single to differential interface method 900 performed in accordance with the present invention. In a block 905 , a power supply at a single ended source is floated. Then, in a block 915 , the terminals of the single ended source are referenced through high impedances (Z HIGH ) to a system ground. In a block 925 , a single ended source output is referenced to the floating single ended source ground.
In a block 935 , it is ensured that there are no current return paths except through a single transmission line coupled to the single ended source. Moreover, in a block 945 , it is ensured that the single return path is operable across a broad range of operational switching frequencies of the single ended source. This range of frequencies includes frequencies from DC to a maximum switching frequency of the single ended source. In embodiments where the single ended source is a clock source, then the range of frequencies includes frequencies from DC to the maximum clock switching frequency of the clock source. In a block 955 , uniform controlled impedance is used via transmission lines to control all the return current paths of a system employing the single to differential interface method 900 .
In a block 965 , the various transmission lines are terminated with their respective characteristic impedances as shown by Z cl , Z c2 , and . . . Z cn . In a block 975 , one of the differential signals is referenced to a voltage logic level high as shown by V LH . In a block 985 , the other of the differential signals is referenced to a voltage logic level low as shown by V LL . Ultimately, in a block 995 , the receiver power supply is referenced to a system ground that employs the single to differential interface method 900 .
The particular order of the various functional blocks as shown within the FIGS. 7, 8 , and 9 may be transposed and interchanged in certain embodiments of the invention. The exemplary embodiments are used to show the operation of the present invention. Clearly, in designing and performing a method that is within the scope and spirit of the invention, certain orders of the functional blocks may be moved around and interchanged.
In view of the above detailed description of the present invention and associated drawings, other modifications and variations will now become apparent to those skilled in the art. It should also be apparent that such other modifications and variations may be effected without departing from the spirit and scope of the present invention. | Single to differential interfacing. The present invention provides for an efficient solution to transform an output from a single ended source to a pair of differential signals that are provided to a differential receiver. The differential receiver is any number of devices including a differential clock receiver. The differential signals may be referenced to voltages used to receiver power supply voltages. The present invention obviates the need for an additional differential driver and its required additional devices that are need to perform transformation of a single ended signal to a pair of differential signals. There can be significant cost savings in using the single to differential interfacing that is performed in accordance with the present invention. In one embodiment, two independent power and ground planes are communicatively coupled via a transmission line, or a transmission line-like traces on a printed circuit board, are used to provide uniform impedance control for all return paths within a system. These transmission lines or transmission line-like traces on the printed circuit board have characteristic impedances higher than the characteristic impedances of other transmission paths in the system or the other traces on the printed circuit board. Moreover, a power supply that is used to bias the single ended source is floated with respect to the system ground. The present invention allows for interfacing single ended devices to devices that use differential inputs signals via a cost effective solution in terms of component costs, real estate costs, and in terms of complexity. | 7 |
BACKGROUND OF THE INVENTION
[0001] The present invention relates to the field of hunting and recreation, including still hunting, ice fishing and other forms of sportsman's activities. Currently, many different tools and apparatus need to be utilized if a sportsman desires to still hunt from a blind, still hunt from a stand, ice fish and tow equipment related to such activities. Many, if not all, of these devices as individual components are bulky and cumbersome. Because of this, to buy, store and maintain such a multitude of devices is a cumbersome, not to mention expensive, prospect.
[0002] Present devices offer some of the functionality of the present invention, but none offer all of the versatility or the combination of features that the sports and recreational trailer presented herein does. Some elevating stands offer storage for ATV's, but do not provide the ability to hunt from a ground blind position. Ice fishing huts in the present art do not offer the mobility that the current invention does. Available incarnations of ground blinds generally are not self-elevating. Nothing in the present field offers the ability to combine all of these features, or offers the additional novel aspects of the present invention, such as a dropping hitch and axle assembly.
[0003] The current invention fills the existing gap in technology by providing a single device to competently handle all of the tasks associated with the separate devices listed above. This invention also adds new functionality not before seen in any incarnation of the above devices, such as the ability to lower the entire chassis, or to load the trailer by utilizing a bed-tilting feature.
OBJECTS OF THE INVENTION
[0004] One object of the invention is to provide a device capable of providing shelter for blind hunting.
[0005] Another object of this invention is to provide a device capable of providing an elevated stand for still hunting and other activities which require a heightened position.
[0006] Still another object of the invention is to supply a device which provides shelter for ice fishing and other activities where shelter from weather elements is required.
[0007] Still another object of the invention is to provide a device that facilitates entry and exit by lowering the load floor to be parallel and flush with the ground below it.
[0008] Still another object of the invention is to provide a device that enables the user to carry cargo in the device when being transported to and from the destination.
[0009] Other objects and advantages of this invention shall become apparent from the ensuing descriptions of the invention.
SUMMARY OF THE INVENTION
[0010] According to the present invention, the sports and recreational trailer is a multi-purpose device that may be used for myriad uses, including but not limited to hunting, fishing, observation, hauling and elevated work. It comprises mainly a chassis portion and a platform portion. The platform portion can be positioned at various elevations, ranging from flush with the ground to a substantial height, depending upon the desired use of the trailer. Various other features permit the trailer to be entirely or partially enclosed so that the user can be shielded from weather, to prevent game from scenting the hunter/user within, as well as other uses which shall become apparent. Other components of the invention permit the entire trailer to be put in substantial contact with the ground below.
BRIEF DESCRIPTION OF THE DRAWINGS
[0011] The accompanying drawings illustrate an embodiment of this invention. However, it is to be understood that this embodiment is intended to be neither exhaustive, nor limiting of the invention. They are but examples of some of the forms in which the invention may be practiced.
[0012] [0012]FIG. 1 shows a perspective view of the sports and recreational trailer.
[0013] [0013]FIG. 2A shows a perspective view of the drop hitch assembly in the “up” position.
[0014] [0014]FIG. 2B shows a perspective view of the drop hitch assembly in the “down” position.
[0015] [0015]FIG. 3A shows a perspective view of the drop axle assembly in the “up” position.
[0016] [0016]FIG. 3B shows a perspective view of the drop axle assembly in the “down” position.
[0017] [0017]FIG. 4 shows a perspective view of the elevating assembly.
[0018] [0018]FIG. 5 shows an elevational view of the sports and recreational trailer in the elevated position.
[0019] [0019]FIG. 6 shows a top view of the lifting mechanism.
DETAILED DESCRIPTION OF EXEMPLARY EMBODIMENTS
[0020] Without any intent to limit the scope of this invention, reference is made to the figures in describing the various embodiments of the invention. Referring to FIGS. 1 through 4, a sports and recreational trailer 100 , chassis 101 can support platform 102 , in a number of ways. One such way is directly, i.e. is permanently affixed to chassis 101 . Another method is an elevational connection, that is, a platform that is able to be lifted up relative to chassis 101 , which will be discussed in greater detail below. Other modes of connectivity would be possible as well, and evident to those skilled in the art.
[0021] Chassis 101 would likely be mobile in most applications, to provide added convenience and utility. Mobility can be achieved by attaching various mobility-enabling devices such as wheels 103 for general utility, skids 116 if in a more arctic climate or even buoyant devices, such as pontoon floats 117 if in an aquatic environment. Part of trailer's 100 mobility is being able to be affixed to a towing vehicle 115 , such as a car, truck, snowmobile or all-terrain vehicle (ATV) via hitch 104 . The trailer 100 could also conceivably be self-propelled if desired.
[0022] If trailer 100 is in a configuration by which platform 102 is able to be elevated, additional parts will be configured as part of trailer 100 . One such part would be lift 105 , which can be attached to platform 102 and to chassis 101 . Using lift 105 , platform 102 may be elevated as illustrated in FIG. 5. Such lift 105 would be comprised mainly of linkage 133 attached to chassis 101 . Linkage 133 would comprise a series of crossed bars 134 , each forming a section 135 , with the overall number of sections 135 dependent upon the desired maximum height of the device, as well as other factors which may warrant additional sections 135 . Examples of such varying needs include increased weight capacity or space constraints, such as the need for a shorter trailer. First leg 137 of first section 136 of linkage 133 would be pivotally attached to a fixed point of chassis 101 . Second leg 138 would be slidably attached to chassis 101 by way of channel 139 , which would permit lateral movement of second leg 138 . Such lateral movement is necessary to facilitate the elevation of platform 102 . Horizontal braces 107 may also be utilized to provide additional stability and weight capacity. Other types of lifting mechanisms could also be used, but this particular iteration permits platform 102 to remain flat when in the down position, substantially parallel to chassis 101 . This enables efficient use of space and minimal intrusion of lift 105 and platform 102 when in the stowed, or down position, as well as permitting platform 102 to be used for storage when in the down position, rather than occupying space on the trailer, as other devices in the art do.
[0023] To counteract any torquing forces that may result from the higher center of gravity when elevated, chassis 101 may be outfitted with stabilizers 110 . These may be mounted in several ways, and in several configurations, one of which is pictured in FIG. 5. In this particular embodiment, stabilizers 110 are attached to the rear and/or front of chassis 101 and rotate down to engage the ground below when needed. Stabilizers 110 can take various forms, such as that listed here, as well as telescoping bars that extend out of the box steel forming chassis 101 , as in FIG. 1, or any other out rigging device that could prevent rotational motion of trailer 100 .
[0024] Platform 102 may also be equipped with various other accoutrements to facilitate activities on trailer 100 . One such example would be collapsible shelter 111 , which may be used during hunting or fishing, among other things, for protection from weather. Collapsible shelter 111 would comprise structural ribs 112 that support material 113 such as canvas, nylon, plastic or the like, forming collapsible shelter 111 . Alternately, railing 118 can be employed about the perimeter of platform 102 . Railing 118 can be used to retain objects within trailer 100 or to support concealing mesh 119 or other material, and need not be permanently attached to platform 102 . Concealing mesh 119 can be used to prevent game from spotting the user of trailer 100 and/or as shelter from the weather when affixed to railing 118 or collapsible shelter 111 .
[0025] In addition, platform 102 may have opening(s) 114 in strategically placed positions on the floor to permit access to the ground below. This enables users of trailer 100 to access the surface below for activities like ice fishing, where access to the ground is required. Openings 114 can be used with doors 120 so that openings might not always be exposed and objects pass therethrough.
[0026] Platform 102 may also be configured to permit its rotation about wheels 103 by being releasably attached to hitch 104 . In this manner, platform 102 can be permitted to tilt until it contacts the ground. This precludes the need for a ramp for loading snowmobiles, ATV's or similar items. Ramp 121 can be utilized, if desired, which doubles as a retaining device to keep loaded items within trailer 100 when ramp 121 is closed.
[0027] Dropping hitch assembly 152 may be configured to permit trailer 100 to raise and lower independently of the hitch 104 . This is accomplished by having tongue 123 from trailer 100 connected to another piece which attaches to the towing vehicle. The two can be connected in multiple ways, one of which is in a hinged fashion as illustrated in FIG. 6. This configuration has pivot 151 whereby hitch 104 remains stationary and tongue 123 moves downward, permitting trailer 100 to rest flat on the ground when axles 122 are also disengaged.
[0028] Axle 122 may be constructed in various ways to permit trailer 100 to be lowered and put in substantial contact with the ground beneath it. One method is to have stub axle 124 connected to suspension component 129 , such as leaf spring 125 or similar device, which would be hinged at rear point 126 , and front point 127 would be detachable. It should be noted that this could be configured in the reverse, namely that front point 127 could be hinged, while rear point 126 could be detachable, however in the pictured embodiment, the former method was chosen. In either case, while in the up position, as pictured in FIG. 3A, axle pin 128 can be employed to hold suspension component 129 in place. Also part of this assembly would be suspension winch 130 with cable 131 that would be used to raise and lower the detachable point of suspension component 129 . This procedure is outlined in greater detail below.
[0029] In operation, hitch 104 and trailer 100 can remain in the standard position, or lowered in order to be flush with the ground. If the latter is desired, hitch 104 and trailer 100 must be lowered, though not necessarily in that order. Dropping hitch assembly 152 can be lowered by removing axle hitch pin 150 . This permits the front end of the trailer to move toward the surface below it, while hitch 104 remains attached to towing vehicle 115 . The second step of lowering trailer 101 is to disengage the axles 122 . This is achieved by removing axle pin(s) 128 and actuating suspension winch 130 such that the cable 131 would be released, which allows detachable front point 127 of the suspension component 129 to move upwards, and, in turn, trailer 100 moves downward toward the surface below it under trailer's 100 own weight. Once this procedure is complete, trailer 100 is once again level and ready for use.
[0030] As previously mentioned, trailer 100 can be used in various activities. In operation as a ground blind, trailer 100 would first be positioned in the desired spot. If desired, trailer may be lowered by disengaging hitch 104 and axle 122 . Railing 118 can then be installed, if not fixed, and concealing mesh 119 may be arranged to provide optimal coverage. User may then engage in the desired activity, such as predator calling, observation, hunting or the like.
[0031] In operation as an elevated stand, again, trailer 100 will be positioned where desired, and can then be lowered using axle 122 and hitch 104 . Alternately, stabilizers 110 can be used if the user does not wish to lower trailer 100 . Lift 105 may then be employed to raise platform 102 . In order to do this, an upward force must be applied to platform 102 . On such method of accomplishing this would be to utilize winch 140 , which can be either manual or motorized, to draw in cable 141 or other strand-like material which is attached to second leg 138 by way of pulley 142 . Pulley 142 can also be attached to lifting bar 143 , which consists of a bar 144 and roller 145 . Winch 140 is actuated, which causes lifting bar 143 to rotate, and as this occurs, whereby roller 145 moves along first leg 137 of linkage 133 . As lifting bar 143 rotates the vertical position of roller 145 moves upward, taking with it first leg 137 . Once lifting bar 143 is in a substantially vertical position lifting bar 143 is mechanically prohibited from further torquing, thus the pulling force from cable 141 on pulley 142 transfers to second leg 138 of lift 105 . This force slides second leg 138 along channel 139 toward the end of trailer 100 , in turn causing lift 105 to further elevate platform 102 . To aid in the elevating action, compressible mounts 146 may be employed to assist in providing the requisite upward force by attaching them to the lift 105 and to chassis 101 . Once elevated to the desired height, user may then perform the desired activity, such as hunt, practice shoot, paint or the like.
[0032] In operation as an ice fishing hut, trailer 100 will likely be located on a frozen body of water where fishing is desired. Axle 122 and hitch 104 may then be lowered, thus putting chassis 101 in direct contact with the ground below. Doors 120 to openings 114 may then be opened to access the ice below in order to fish.
[0033] In operation as a utility trailer, ramp 121 may be used to load wheeled or other mobile devices onto trailer 100 , or items can be stored behind railing 118 . Trailer 100 could then be towed normally, used to lift or lower loaded items, or various other activities as previously described.
[0034] Although only a few exemplary embodiments of this invention have been described in detail above, those skilled in the art will readily appreciate that many modifications are possible in the exemplary 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 in the following claims. | The sports and recreational trailer fills the existing gap in technology by providing a single device to competently handle all of the tasks associated with elevated stands, blinds, trailers, fishing huts, and the like. This invention also adds new functionality not before seen in any incarnation of the above devices, such as the ability to lower the entire chassis, or to load the trailer by utilizing a bed-tilting feature. | 4 |
BACKGROUND OF THE INVENTION
This application is a continuation-in-part application of U.S. patent application, Ser. No., 08/187,991 filed Jan. 28, 1994, now U.S. Pat. No. 5,481,431, Entitled "CRIB DEVICE FOR COMPUTER HARD DRIVE OR THE LIKE", Inventors, Hassan Siahpolo, et al.
The present invention relates to an improved computer system, including an arrangement that allows the safe, quick and effortless installation, engagement, disengagement and removal of a hard drive or the like of the system and a method of manufacturing the arrangement and the assembly of the system and IC the devices thereof.
In most, if not all, computer systems, where space is always a high priority, the handling of the relatively heavy hard drive is a serious problem requiring great care to avoid damaging the drive, both in the initial installation thereof and in the later performance of maintenance. This is particularly true in the critical handling and positioning of the drive for electrical connection to the computer system. Because hard drives can not be subject to any great amount of stress or shock, it is highly desirable to find a way to safely handle the drives when installing them and in their removal from the computer systems. In the past, the heavy very expensive hard drives have been handled by hand and fastened to the computer chassis by hand tool tightened screws.
Another important consideration in installing and removing the drive is to find away that allows the use of a slotted or plug-in electrical connection system, wherein the drive can be connected to the system without the need of the use of hands or tools, or the extra step or steps represented thereby. Also, in past designs, the connection of the drive in a slotted or plug-in design required a considerable force to effect the electrical connection and disconnection, which in many cases because of the location of the drive in the computer system made it very difficult and time consuming to apply the necessary force required to effect the connection and disconnection.
Some of the same and different problems exist in present day designs for floppy disk drives, CD-ROM, tape drives and other computer components. In one prior design such disk drives were provided with wheel-like mounted grommets that were inserted in pedestals mounted on the floors of chassis and had portions that extended outwardly of the pedestals. The drives were held in place by legs provided in the inside of the covers of the cases that fit into the pedestals and which had portions that wedged against an associated grommet. This prior design while providing an effective mounting and securement arrangement for certain chassis designs, was not found acceptable for other chassis designs. Also the prior design involved the use of extra parts, fasteners and fixtures and related assembly time, which also were lnvolved in the prior mounting design for CD-ROM drives.
Any device or system that answers these objectives should be low in cost and high in reliability, in addition to reducing the number of required parts and reducing the installation and removal time and cost.
BRIEF DESCRIPTION OF THE INVENTION
The present invention meets each of the aforesaid requirements as relating to a hard drive by providing an improved computer system, including a user friendly crib arrangement for installing a hard drive element or the like of a computer system. The crib arrangement allows the safe, quick and effortless installing and, if desired, removal of an element to and from the system and one that allows the use of an electrical plug-in connector, where no tool force and very little hand force is required to effect the electrical connection and where the required force is applied in a very convenient manner.
More particularly, the invention provides an improved computer system, including a crib device and a method of manufacture and assemblage designed to be received in a chassis of the computer, the chassis having elongated openings that receive holding and guiding elements provided on the crib device. The openings also provide a mechanical mechanism, such as for example, cam engaging surfaces adapted to be contacted by cams of the crib device, through which action the crib device and a hard drive that has been secured thereto can be moved in reverse directions by an actuator that may take the form of a handle to which the cams are made a part, the leverage effect of the handle and cams providing the required force to engage and disengage the drive to and from a slotted connector with very little effort. The employment of a handle in this manner allows for the safe, quick and inexpensive handling of the hard drive to and from the chassis and the ability to connect and disconnect the electrical connection with a minimum of hand force and without any need to use tools.
The present invention also provides a mounting and securing arrangement for floppy disk drives, CD-ROM drives and other internal hardware elements of a computer. Included in this arrangement is the employment of grommets or the like mounted on the drives and adapted to fit into openings formed in walls of the chassis in a self containing manner, and which requires no additional parts or time in installing or removing. In this arrangement the drive can be installed and removed without the use of fasteners, fixtures or tools or the removal of other parts. Nor does the arrangement rely on the cooperation of other parts, such as the cover of the case, to maintain the drive in a secured position in the case.
BRIER DESCRIPTION OF THE DRAWINGS
FIG. 1 is a schematic plan view, with the top part removed, of an improved computer system incorporating a crib device according to the present invention,
FIG. 2 is a plan view of a crib device illustrating the base portion thereof without its handle,
FIG. 3 is an elevational view of the base portion shown in FIG. 2,
FIG. 4 is a section view taken on line 4--4 of FIG. 2,
FIG. 5 is a plan view of a handle used but shown apart from the base portion of the crib device shown in FIGS. 2 and 3.
FIG. 6 is an elevational view of the handle shown in FIG. 5,
FIG. 7 is an elevational view, simplified in certain respects, of a chassis of a computer system illustrating a crib device and hard drive supportable by the handle above the chassis in position to be lowered into the chassis,
FIGS. 8, A, B, C and D, are four schematic elevational views illustrating four related, but different, positions assumed by the crib device relative to the chassis of a computer system, in installing the crib device with a hard drive in the chassis and moving the drive into a slotted electrically connecting position,
FIG. 9 is a second embodiment of the invention and illustrates in an isometric view a portion of the chassis of the computer designed to receive several drives in a two part bay area formed in the chassis,
FIG. 10 is an enlarged partial elevational view of one of the holding openings formed in the left end bay shown in FIG. 9,
FIG. 11 is an isometric expanded view of the left end bay shown in FIG. 9, along with a showing of a floppy disk drive and a CD-ROM drive, spaced from the bay but with broken line indications of their operative positions in the bay, and
FIG. 12 is an elevational view of one of the grommets mounted on the drives shown in FIG. 11.
DETAILED DESCRIPTION OF THE INVENTION
With reference to FIG. 1, there is illustrated in outline form an improved computer system according to the present invention, including along with other customary components and circuits, a computer box 1, a motherboard 2, a power supply unit 3, a CPU unit 4, two memory units 5, hard drive 6 having a printed circuit board 6A, a floppy disk drive 7 and input and output facilities 8 and 9, all these units being well known in the art.
The system includes a crib device 10 illustrated best in FIGS. 2, 3 and 4. The crib device 10 consist of a generally rectangularly shaped box 12 having, as one views FIGS. 2 and 3, an open top 14 and two opposed open ends 16 and 18. On the two longitudinal sides of the box 12 there are provided identical upright members or walls 20 that extend the full length of the box. The substantial opening 22 formed in the bottom 24 of the box is provided to reduce its weight and allow air flow cooling access for the bottom of the hard drive, the air flow being indicated by the legend A in FIG. 2. As noted above, the bottom of the hard drive has a customary printed circuit board 6A with its usual electrical components.
On the outside of each upright member 20 there are formed two spaced apart support and retention members 26 shaped, as best shown in FIG. 3, as segments of cylinders with the segments being arranged at the top and bottom and separated by spaces at the 3 and 9 o'clock positions. The members 26 are located near the ends 16 and 18 of the box 12. The members 26 at the end 16 of the box 12 is provided with brackets 28 that are mounted on the outer ends of the associated two members 26 to form spaces 29 between the adjacent portions of the upright members 20. As noted in FIGS. 2 and 3, the brackets extend parallel to the upright members 20 on either side of the support members 26.
Midway between the ends 16 and 18 on the outside of the walls 20 there are formed two in line spaced apart trunnion members 30 having cylindrical portions that project outwardly from the associated walls. The outer ends of the trunnion members 30 are provided with two diametrically oppositely arranged narrow projections 32. At the end 18 of the box 12 formed in the bottom 24 is a latch opening 34. The two walls 20 of the box 12 are provided with deflectable fingers 36, best shown in FIGS. 3 and 4. To form these fingers the walls 20 are provided with upright rectangular openings 38 with portions of the walls unremoved extending from the lower ends of the openings and terminating short of the upper ends of the openings thus forming the upwardly extending fingers 36. As best shown in FIG. 4, portions of the outer surfaces of the fingers 36 project beyond the adjacent surfaces of the walls 20 of the box 12, allowing the fingers 36 to be deflected inwardly when contacted by outside surfaces.
In referring to FIG. 3, on the outside surface of the bottom 24 below the walls 20 and at the very end on the left, as one views this figure, and inward from the opposite end, there are provided four feet 39, two being shown in FIG. 3. These feet provide frictional reducing sliding surfaces, as will be noted below, and aid in air flow for cooling the hard drive by providing a space between the floor 65 of the chassis or a crib device arranged below. It will be obvious to a skilled person in the art that the box 12 may take other forms, for example, a simpler form than described above, such as consisting of a single base member.
With reference now to the handle that is attached to the box 12, reference is made to FIGS. 5 and 6. The handle 40 consist of two identical arms 42 which are connected at their one ends by a cross member 44, which cross member at its upper surface is provided with a latch 46 in the form of an inverted U shaped member having an outer free collapsible end 48. Also at the latch end of the arms 42, the arms have circular recesses 49 facing the bottom of the arms designed to pass over adjacent support members 26 of the box 12. At the extreme inner end of each arm, the arms are provided with bosses 50 having openings that slide over the trunnion members 30 of the box 12, the bosses each having diametrically opposite slots 52 that slide over the projections 32 of the box 12. By this construction, the handle 40 is pivotally connected to the box and allowed to rotate from an upright carrying position, to a horizontal latching position and to two positions on either side of the carrying position, which are designated the forward and rearward crib device moving positions.
The distance of the separation of the arms 42 and the axial dimension of the bosses 50 are such that the inside of the arms are separated from the walls 20 of the box 12 sufficient to allow cam elements 54 to be arranged inside the arms 42 and the vertical outside surfaces of the walls 20. In this construction, while the handle 40 is free to rotate there will exist no play or transverse movement of the handle relative to the box 12 due to the restraining action of the fingers 36. The two cam elements 54 are identically formed in the general shape of a triangle, in which when the handle 40 is in its vertical most position, i.e. its carrying position, the cam elements 54 present two upper rounded cam surfaces 56 separated by one of the sides of the triangle, these surfaces being better shown in FIGS. 7 and 8. The cam surfaces 56 form first parts of two cam mechanisms.
It will be appreciated that while two cam elements are employed in the preferred embodiment, if desired, a single cam element 54 may be employed. It will also be apparent to those skilled in the art that other forms of an actuator can be used instead of the handle design illustrated, for example, a single lever arranged in several different ways can be used. As will be more apparent later, the leverage effect of the throw of the cam elements 54 and the length of the arms 42 are designed to allow the effortless movement of the crib device 10 when engaging and disengaging the hard drive, two such drives being shown only in FIGS. 7 and 8 at 6 and 6A.
The box 12 is dimensioned to permit the placement of a standard hard drive into the box 12 where it may be secured to the box by either screwless fastening facilities or by screws. In the design being illustrated, a hard drive lying flat against the bottom 24 of the box 12 is secured to the crib device 10 by four screws 58 passed through openings provided in the support and retention members 26 and into cooperative threaded holes, not shown, in the hard drive, two of the screws being shown only in FIG. 7. With other hard drives the screw connection may be made from the bottom of the drive or the drive may be secured to the crib device in some other manner. The crib device being illustrated is designed for a hard drive measuring approximately 5 3/4"×3 3/4"×1" which as noted above may be considered one of several standard sizes of drives in use today in desk top computer systems. While the invention for illustration purposes is used with a hard drive, it will be appreciated that the crib device may be employed to handle other elements of the computer system, such as a floppy disk drive.
The crib device 10 described above is designed to be made out of a polymer material, although it can be made of metal, such as an aluminum alloy. The choice of the material will depend on cost, environment, ergonomic and performance considerations.
In referring now to the chassis 60 designed to cooperate with the crib device 10, reference is made to FIGS. 7 and 8A-8D. Particularly in FIG. 7, there is illustrated the left end of a chassis 60, which while only one side and a portion of its back wall are shown, it will be understood that the chassis takes the form of a box like structure that makes up a small part of the composite computer box or chassis. The chassis 60 has an open top 62, a bottom 64, which is joined and supports two upright walls 66A, one of which is only shown but the other indicated as 66B in the figures. The bottom 64 includes a flat sheet metal floor 65, which is provided with an opening, indicated by surfaces 67 shown in FIG. 7, located below the opening 22 of the crib device 10 and sized to allow air flow cooling of the hard drive, the air flow being indicated by the legend A in FIG. 7. One end of the chassis has a back wall 68 on which a slotted or plug-in electrical connector 69 is mounted and over and into which the matching connector 71 of the hard drive 6 is forced into. These connectors are of the type well known in the computer industry. In FIG. 7, two electrical connectors 69 are shown. The opposite end 72 of the chassis is open.
As best shown in FIG. 8A, each side of the walls A and B which are identically constructed, have three vertically arranged openings, 74, 76, and 78, reading left to right, the openings 74 and 78 each have a set of two vertically spaced recesses 80, the lower and upper recesses of one set being in horizontal alignment and sized to loosely receive the support and retention members 26. This alignment assures that the electrical connector of the hard drive will be on the proper plane for registry with the electrical connector of the computer system. The openings 78 in both walls 66A and B are actually formed by the open end of the chassis 60. The openings 76 in the walls 66A and B have straight vertical cam contacting cooperating sides or surfaces 82 and 84 that form second parts of the two cam mechanisms. While in the preferred form, the cams are formed on the cam elements 54, they may be formed on the chassis 60, in which case they would engage straight surfaces formed on the handle 40.
The openings 74 and 78 have bottom supporting edges 86, (see FIGS. 7 and 8A) and are contacted in a supporting relationship with the retention members 26, while the bottoms of the openings 76 are held out of contact with the bottoms of the trunnions 30 of the box 12 due to their smaller outside diameters relative to the trunnions 30. As is customary of the chassis is formed out of relatively heavy gauge steel sheet metal.
As shown in FIG. 3, the front wall 20 of the box 12 of the crib device 10 is provided with three holes 81 arranged on a common arc. The back wall 20 is provided with only two similar holes corresponding to the two upper most holes 81. As shown in FIG. 6, on the inside vertical surface of both of the cam elements 54 there are provided projecting buttons 83 arranged to pass through the aforesaid arc. The lower most single hole 81 when entered into by the button 83 is used to register the projections 32 of the trunnions 30 with the openings 52 of the arms 42, to aid in the assembly of the handle 40 on the trunnions 30 of the box 12. The holes 81 at the 11 o'clock position, as one views FIG. 3, are provided to hold the handle 40 in its carrying and inserting and removing positions, when they receive the buttons 83 to assist in the quick and easy installing and removing of the crib device and hard drive. The remaining holes 81 are provided to relieve any stress on the handle 40 that may occur when the handle is latched due to the stress placed on the handle by the latching action.
In briefly describing the operation of the improved computer system, including the crib device 10 and chassis 60 and their assemblage, with the top, not shown, of the computer system removed allowing immediate access to the hard drive chassis 60, a crib device 10 is inserted into the openings 76 of the chassis. Before this is done, a hard drive 6 will have been secured to the crib device 10 by screws 58. The thickness of the bottom 24 of the crib device and the height of the opening 67 of the chassis are such that the outer surfaces of the lowest most components of the printed circuit board of the hard drive are prevented from contacting the floor 65 of the chassis. During this phase, the handle 40 is used to carry the drive with the handle in its vertical position, as shown in FIGS. 7 and 8A. In this position, the two cam elements 54 assume the laid back positions so that they can pass unrestrictedly into the openings 76 of the walls 66A and B of the chassis 60. When lowering the crib device, the support and retention members 26 will be received by the openings 74 and 78 and come to rest on the surfaces 86 of the chassis directly in front of and in proper registry with the two sets of lower recesses 80 thereof associated with the openings 74 and 78.
The crib device 10 will be guided and held in the proper position during its downward movement by the fact that the brackets 28 arranged at the front of the crib device will slide over the overlapped portions of the walls 66A and B, of the chassis 60, in which the walls 20 of the crib device will be held between the brackets 28 and the walls 66A and B. As noted above, the brackets 28 not only control the downward movement of the crib device but also its longitudinal movement. In this regard, it will be observed that in all three positions represented by FIGS. 8B, C and D the brackets 28 are always in an overlapping condition relative to the walls 66A and B of the chassis 60.
During the downward movement of the crib device 10, the four fingers 36 will engage and be deflected inwardly as they contact the inside surfaces of the chassis walls 66A and B, thus preventing transverse movement of the crib device and the secured hard drive. After this very simple and quick operation, the handle 40 can be rotated from its carrying vertical position clockwise, as one views FIGS. 7 and 8B and 8C, to the position it is shown to assume in FIGS. 8C and D. This action will cause the forward most cam surfaces 56 of the cam elements 54 to contact the wall surfaces 84 of the walls 66A and B forcing the crib device and hard drive to the left on one views FIGS. 7 and 8. This movement will require very little force which may be applied by a single finger.
The controlled restraining of the crib device by virtue of the edges 86, the recesses 80, the brackets 28 and fingers 36 will assure unhesitated entrance of the connector 71 of the hard drive with the connector 69 of the computer system. In the connected position, the latch 48 of the handle 40 will pass into the latch opening 34 of the box 12, latching the crib device and the hard drive in the chassis 60, and firmly holding these interconnected units against any movement relative to the chassis, due to the locking of the cam elements 54 against the surfaces 84 of the chassis and the restraining action of the fingers 36. Also in this position, the circular recesses 49 of the arms 42 will pass over the adjacent support members 26.
In removing the hard drive and crib device, the above procedure is reversed. In this case, the frontward most cam surfaces 56 will engage the vertical surfaces 82 of the openings 76 as the handle is rotated counterclockwise, by the same small force required to engage the connectors, as shown in FIG. 8C, for example. This will create the necessary force to disengage the connectors 69 and 71 and retract the crib device 10 and hard drive 70 to the position shown in FIG. 8B, where the handle can be used to quickly and easily lift the drive out of the chassis 60. While the above description contemplates employment of the crib device 10 to both install and remove a drive, the crib device may in certain applications be employed only to effect the installation of the drive.
In the applications where it is desirable to employ two or more hard drives in the computer system, the design illustrated in FIGS. 7 and 8 will accommodate this interest. In these figures the heights of the walls 66A and B of the chassis 60, and openings 74, 76 and 78, as well as providing second sets of recesses 80 and extended cam surfaces 82 and 84 allow a second hard drive 6A to be stacked and supported above a first drive 6. In this construction, the four feet 39 of the second crib device 10A will come to rest on the upper edges of the walls 20 of the lower crib device 10 and act as sliding surfaces for the upper crib device 10A and its drive 6A, and also provide the air flow cooling advantage, noted above, by virtue of the separation between the two crib devices. The upper surfaces or edges of the walls 20 of the lower crib device 10 provide straight continuous supporting and guiding surfaces for the feet 39 of the upper crib device 10A. The walls 20 and hence the feet 39 being located inside the walls 66A and B of the chassis 60 allow the feet of the upper crib device 10A to ride over the walls 20 of the lower crib device 10.
Turning now to the second embodiment of the invention, FIG. 9 illustrates the left and right hand ends of the chassis 60 designed to receive the drives of the computer box 1. As noted in FIG. 1, adjacent one side of the chassis the hard drive 6 is located at the one end and the floppy disk drive 7 at the opposite end of the chassis. Also shown schematically at 86 is a representation of a CD-ROM drive. FIG. 9 indicates that the drive receiving area of the chassis 60 is divided into two bays 88 and 90. The former receives the hard drive 6 at the right and the latter the floppy disk drive 7 and CD-ROM drive 86 at the left. The bottom 64, its floor 65 and the upright walls 66A and 66B are separated by a transition portion 92, the floor portion 65 of which supports part of the electrical system and connectors for the drives 7 and 86, and while in this area the wall 66B differs slightly from wall 66A the remaining portions of the walls 66A and 66B of the bay 90 are identical, except for being opposite hand.
Each parallel wall 66A and 66B in the bay 90 has three flat integral sections 94, 96 and 98, each section being made up of two identical transversely spaced parts. The sections 94 are connected to the floor 65 and have pairs of spaced openings 100. The openings 100 have lower horizontal portions joined by vertical portions, which at their upper ends are formed into second horizontal portions, the latter portions being formed in the sections 96 of the walls. The lower horizontal portions of the openings 100 point in the direction to the left and the openings are arranged to form two spaced apart directly opposed pairs of cooperative openings.
In the wall sections 98 two additional spaced apart directly opposed pairs of openings 102 are provided. These openings are located above the openings 100 a vertical distance to accommodate the height dimension of the CD-ROM drive and have horizontal portions that extend in the opposite direction when compared with the horizontal openings 100. The horizontal surfaces and the closed ends of the openings 100 and 102 are identically constructed. The walls 66A and 66B being made up of relatively heavy gauge steel sheet metal provide support surfaces 104. The openings 105 in the wall sections 96 and floor 65 are provided for air circulation for the drives.
FIG. 10 illustrates more of the details of one of the openings and its lower horizontal surface 104 and closed end 106. At the entrance of the closed end 106 and directly below the front end of the opening, where it is at its narrowest, there is provided a slightly raised portion 108, shown exaggerated, which has the effect of closing the mouth of the opening a desired amount. The lower surface 108 has a cooperating similar surface 110, the two surfaces creating an interference fit for a grommet, not shown, mounted on the drives.
In FIG. 11 the chassis bay 90 is again illustrated along with the floppy disk drive 7 and CD-ROM drive 86. The floppy disk drive is received in the lower portion of the bay 90 formed by the wall sections 94 and 96 and in the two pairs of openings 100 formed therein. The floppy disk drive 7 is a well known design, and on its two opposite long sides 110 and 112 two pairs of grommets mounting, holding and yieldable members or 114 are mounted, the grommets being spaced to fit into a different one of the openings 100. The grommets are secured to the vertical sides of the disk drive by screws 115 attached to the sides. As seen from FIG. 10, in mounting the drive into the openings 100, the grommets are adapted to slide into the vertical sections until they reach the bottom of the openings, after which the drive is moved to the right towards the front of the chassis 60 to lock the drive to the chassis.
The CD-ROM drive 86 is mounted directly above the floppy disk drive, which is also of a well known design and on its opposite long sides 116 and 118 pairs of grommets 120, similar to the grommets 114 are mounted, the grommets being spaced to fit into a different one of the openings 102. The grommets are secured to the sides 116 and 118 by screws 122 that attach to the sides. In mounting the drive 86 in the chassis 60 the operation is as described above with the floppy disk drive, except in the case of the CD-ROM drive it is moved to the left or towards the back of the chassis. FIG. 11 indicates at 122 and 124 some of the electrical elements and connectors for the two stacked drives.
One of the grommets 114 and 120 is shown in FIG. 12 and comprises a one piece unit having an enlarged front cylinderical mounting portion 126 contactable with an associated outside surface of one of the walls 66A or 66B and a rear cylinderical portion 128, both portions having a common hole 130, the hole being countersunk at 132 to receive one of the screws 115 or 120. The grommets can be one of several types of copolyester elastomer, for example, of the type sold by the General Electric Company under the registered trademark "LOMOD".
In the illustrated example of the grommets, the diameter of the portion 128 is approximately 13 mm and the interference fit 108-110 is approximately 12.45 mm. The rear portions 128 of the grommets are sized to slide easily into the vertical portions of the openings 100 and 102 until they reach the bottoms of the openings. At this point, the portions 128 of the grommets are urged through the interference fits until they contact the backs of the openings. This use of the grommets as mounting and holding devices and the use of the compressing surfaces formed by the interference fits prevent the drives from becoming dislodged, in an arrangement that does not requires any other parts, fasteners or figures or cooperation with other elements to accomplish the result. More particularly, the interference fit is employed to compress the material of the portion 128 of the grommet a desired amount, which material has been selected so that its elastic characteristic will after released from the fit expand against the compressing surface of the closed end 106 of the opening 100-102 to create a self sustaining holding force sufficient to firmly secure the drive to the chassis. The compression and release is achieved by only a hand urging in moving the drives into and out of the openings 100 and 102.
In briefly explaining the mounting of the floppy and CD-ROM drives 7 and 86, respectively with the top of the box 1 removed exposing the bays 88 and 90, the floppy drive is placed in the openings 100 as explained above, and connected by hand to its electrical components 121. After this, the CD-ROM drive can be arranged above the floppy drive by placing it in the openings 102 as noted above, and connected by hand to its electrical components 124. This will place the receiving slot of the floppy drive in a desired position to be exposed to the front side of the box 1 and in a position to receive a floppy disk.
In like manner, the CD-ROM drive will have its slide end exposed to the usual opening provided in the front side of the box 1 allowing the slide to move outwardly to receive a media. In both cases of the drives, the openings are located and dimensioned to place the front ends of the drives in the desired positions relative to the front side of the box 1.
In accordance with the provisions of the patent statutes, we have explained our invention in terms of its preferred embodiment, however, it will be readily understood by those skilled in the art to which the invention pertains that it may be practiced otherwise than illustrated and described. | The disclosed invention relates to a computer system, including a crib device and chassis for installing and removing a hard drive to and from the chassis of the system. The drive is securable to the crib device, which has a handle that allows the drive to be carried to and away from the chassis. The crib device and chassis have cams and cam engaging surfaces that cause the crib device and drive to move to effect engagement and disengagement of the electrical connectors of the computer system and drive. Also disclosed is a mounting arrangement for a floppy disk drive and CD-ROM drive. | 6 |
FIELD OF THE INVENTION
The invention relates to pipe couplings, and in particular to couplings used to connect pipes to fittings such as valves and adapters.
BACKGROUND OF THE INVENTION
Particularly in the plumbing and waterworks industries, situations frequently arise during installation or repair of piping where it is necessary to connect pipes to various fittings such as corporation valves, curb valves and various adapters. These situations can arise for example during water service line installation or repair. Such piping can include service tubes and may be made of polyethylene pipe/tubing for example.
Typically, such fittings are provided with a stub, usually externally threaded, for receiving a sealed fluid-communicating connection with the pipe. The threading on such stubs is typically of an industry standard such as corporation fitting thread, to allow standard threaded couplings to be mounted thereon.
Such pipe-fitting couplings typically come in two main forms. In a first form the coupling is integral with the pipe. The present invention is directed to the second form where the coupling is a separate device that clamps on to, or is otherwise sealingly affixed to the end of the pipe. In either case the end of the coupling intended to engage the fitting stub is provided with internal threading and the coupling is connected to the fitting stub by turning one relative to the other thereby engaging the internal threading of the coupling with the external threading of the stub.
A typical manner in which such a separate coupling is used to connect a pipe to a fitting stub is as follows. First a coupling body, having internal threads at a forward end for engaging the external threads of the stub, and a constricted rearward end, is slid on to the pipe, rearward end first. A combination of various internal elements including seals and camming or gripping means are then slid on to and/or in to the pipe. Finally, the coupling body is screwed onto the stub trapping and compressing the seals and the camming or gripping means. In particular, the constricted rearward end of the coupling body presses the seals and camming or gripping means against the end of the stub or against the exterior or interior surface of the pipe. The compressed seals create a hydrostatic seal between the stub and the pipe, while the camming or gripping means are urged to a locking and restraining position preventing the pipe from being pulled out of the coupling inadvertently. Using such a coupling, a secure pressure-sealed connection is made.
Where the pipe has a high level of structural integrity, the camming or gripping means may be applied against the outside surface of the pipe without the need for any additional support on the interior of the pipe. However, where excessive exterior pressure on the pipe would result in the pipe collapsing such that the pipe is damaged and/or the seals or camming or gripping means fails, internal support is typically provided in the form of a tubular insert either in plastic or stainless steel. Where the fitting stub already has a pipe-supporting extension for insertion within the pipe, the coupling need not provide a tubular insert.
One difficulty with such couplings is the need for the user to handle a number of small elements (typically the seals, and camming and gripping elements) during installation. This can result in frustration on the part of the user while he fumbles with the various parts to ensure that they are installed in the correct order and orientation. If the user fails to install these parts in the correct order and orientation, the connection can fail resulting in leakage. This disadvantage is particularly acute where installation takes place in difficult conditions, for example where the fitting is located in an awkward location, or where the installation is taking place on waterworks, often with the user standing in a wet and muddy hole where fingers are slippery and where a dropped part is irretrievably lost.
Further, the camming or gripping means typically used on the exterior of the pipe can often result in an excessive localization of forces that may result in damage and/or collapse of the pipe that can result in failure.
Additionally, most present couplings are not reusable since the camming or gripping means used are permanently deformed during use.
Finally, with most present couplings the coupling can easily be under-tightened or over-tightened onto the pipe and/or the fitting, which may result in damage to the pipe, to the fitting or to the coupling and may also result in failure of the coupling.
SUMMARY OF THE INVENTION
This invention provides an improved coupling for connecting pipes to fittings, which improved coupling addresses one or more of the problems noted above.
In a broad aspect, the present invention provides a coupling for creating a fluid-conducting connection between a pipe and a stub, said stub being free of a pipe-supporting extension over which the pipe is to be slid, said coupling comprising: a coupling body having a forward end for being secured to the stub, a rearward end for receiving the pipe, and an internal bore therethrough; stub securing means for securing the forward end of the coupling body to the stub; a gripper located within the internal bore of said coupling body for gripping said pipe; gripper retaining means for retaining said gripper within said coupling body during handling of the coupling body; pipe-supporting means for providing internal support for an end section of the pipe being engaged by the coupling; gripper engaging means for causing the gripper to grip the pipe; and sealing means for creating a seal between the stub and the pipe.
Other aspects of the invention include the above coupling wherein:
the gripper is a gripper ring having three or fewer spaced annular interior gripping surfaces for gripping said pipe; the gripper ring has two spaced annular interior gripping surfaces for gripping said pipe; the gripper ring is a split ring such that the gripper ring can constrict radially; the annular gripping surfaces have annular teeth thereon; the gripper is sized to fit between an interior surface of the coupling body and an outer surface of the pipe once the pipe is received within the rearward end of the coupling body; the pipe-supporting means is an insert having a rigid support tube at its rearward end, said support tube being adapted to be slid within the end section of the pipe; a rear end of said support tube is located rearwardly of said gripper; the sealing means for creating a seal between the stub and the pipe includes a rearward seal mounted on an exterior surface of said support tube to create a seal between the support tube and the pipe when the support tube is slid within the pipe; the rearward seal is an O-ring; the support tube has forward-facing barbs on its exterior surface to resist inadvertent pullout of the pipe from the coupling; the barbs on the support tube are annular; an interior surface of a rearward end of said support tube is beveled; the support tube is sized such that its exterior surface closely fits within the pipe; the insert has at its forward end, an inner web adapted to be inserted within the stub; the inner web is sized to fit closely within the stub; the sealing means for creating a seal between the stub and the pipe includes a forward seal mounted on an exterior surface of said inner web to create a seal between the inner web and the stub when the inner web is slid within the stub; the forward seal is an O-ring; the insert has a radially outwardly projecting annular rib extending from a forward end of the support tube; the annular rib has a forward face adapted to abut against a rearward end of said stub, and a rearward surface adapted to abut against a forward end of said pipe; the insert has an outer web extending rearwardly from an outer end of said annular rib; the outer web is sized to fit closely between the pipe and the coupling body; the gripper engaging means comprises gripper constricting means for radially constricting the gripper such that the gripper engages an exterior surface of said pipe; when constricted, at least a portion of said gripper intersects a plane which includes the rearward seal and which is perpendicular to a longitudinal axis of said coupling body; the gripper has a sloped rearward surface, the gripper retaining means is a gripper retaining recess formed on an inner surface of the coupling body for receiving said gripper, said gripper retaining recess having a sloped rearward surface, said sloped rearward surface of said gripper retaining recess adapted to abut the sloped rearward surface of the gripper, and said gripper constricting means comprising moving the coupling body forward relative to the gripper such that cooperation between the sloped rearward surface of the gripper and the sloped rearward surface of the gripper retaining recess causes the gripper to radially constrict; the coupling body is moved forward relative to the gripper by moving the coupling body forward and resisting substantial forward movement of the gripper by abutting of the forward end of the gripper against a rearward end of said outer web of said insert, forward movement of said insert being restrained by abutting of said forward face of said annular rib against the rearward end of said stub; the gripper has a sloped forward surface, the rearward end of the outer web has a beveled inner surface, said beveled inner surface of said rearward end of said outer web adapted to abut the sloped forward surface of the gripper, said gripper constricting means further comprising moving the gripper forward relative to the outer web such that cooperation between the sloped forward surface of the gripper and the beveled inner surface of said outer web further causes the gripper to radially constrict; the gripper is moved forward relative to the outer web by the forward movement of the coupling body causing the gripper to move forward slightly; the stub is externally threaded and the stub securing means is an internal threading of a forward portion of said coupling body, an interior of said forward portion of the coupling body being sized to fit closely over the stub, and said internal threading of said coupling body matching the external threading of said stub; the coupling body is moved forward by screw-tightening the forward portion of the coupling body onto the stub; the gripper retaining recess is a circumferential groove; an exterior surface of the forward portion of said coupling body is hexagonal to facilitate tightening of the coupling body onto the stub; the stub further comprises a shoulder positioned forwardly of said external threading, said shoulder having a rearward face, and said coupling being fully tightened when a forward face of said coupling body abuts against the rearward face of the shoulder of the stub; the pipe is polyethylene; coupling is coupled to the stub; and/or the coupling is coupled to the pipe.
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
The present invention will be more fully understood by reference to the following detailed description of a preferred embodiment of the present invention when read in conjunction with the accompanying drawing, in which like reference characters refer to like parts throughout the views and in which:
FIG. 1A is a partially broken, side cross-sectional view of a coupling in accordance with a preferred embodiment of the present invention, installed on a fitting stub and pipe;
FIG. 1B is a view similar to FIG. 1 , but showing the counling in a loosened state with respect to the fitting stub and pipe;
FIG. 2 is an exploded side view of the coupling;
FIG. 3 is a side partial cross-sectional view of the coupling;
FIG. 4 is a side cross-sectional view of a coupling body of the coupling;
FIG. 5A is a side non-cross-sectional view of a gripper ring of the coupling;
FIG. 5B is a side cross-sectional view of the gripper ring of FIG. 5A ; and
FIG. 6 is a side cross-sectional view of an insert of the coupling.
DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS
A preferred embodiment of the coupling of the present invention is shown in the attached drawings. In the exemplary application illustrated, the coupling is used to connect a polyethylene pipe to a cast brass alloy fitting stub in a waterworks application. The coupling is located between the pipe and the stub.
In this description and in the claims, the terms “axial” and “axially” are used to describe a direction parallel to a centerline of the pipe once the coupling is installed, while “radial” and “radially” are used to describe a direction perpendicular to and extending from the centerline of the pipe once the coupling is installed. Further, “forward” is used to describe features which are located nearer the fitting stub and away from the pipe once the coupling is installed, while “rearward” is used to describe features which are located nearer the extended pipe and away from the fitting stub once the coupling is installed.
FIG. 1A is a cross-sectional view of the coupling 10 installed on a fitting stub 22 and pipe 24 . The coupling 10 consists mainly of a coupling body 12 , a gripper ring 14 , and an insert 18 having a froward seal 20 and a rearward seal 16 . The coupling 10 is shown affixed to the stub 22 of a fitting (not shown), and with the pipe 24 installed therein. In this exemplary application, the fitting can be any plumbing or waterworks fitting having an externally-threaded stub 22 having the features described herein, onto which it is desirable to connect the pipe 24 . FIG. 1B depicts the coupling 10 loosely engaging the stub 22 while FIG. 1A shows the coupling 10 tightened on to the stub 22 . FIG. 2 shows an exploded side view of the coupling 10 while FIG. 3 shows a side partial cross-sectional view of the coupling.
Coupling Body
The coupling body 12 in the preferred embodiment (illustrated in detail in FIG. 4 ) is made of cast brass alloy and is generally a hollow cylinder. The coupling body 12 has a nut section 26 at a forward end, a constricted section 28 at a rearward end, and an intermediate section 30 in between.
The nut section 26 of the coupling body 12 is provided with a hexagonal exterior to accommodate hand-tightening or tool-tightening of the coupling body 12 on to the fitting stub 22 . The interior of the nut section 26 is sized so as to engage an outer surface of the stub 22 and is provided with internal threading 31 which matches external threading 33 of the stub 22 . In the preferred embodiment, the threading 33 , 31 on the stub 22 and the interior of the nut section 26 is corporation fitting thread, though it is to be understood that other threads can be used. A forward end of the nut section 26 is provided with a flat face 35 which abuts a rearward face 37 of a shoulder 39 on the stub 22 when the coupling body 12 is fully tightened onto the stub 22 as shown in the top half of FIG. 1 .
The coupling body 12 is provided at its rearward end with a constricted section 28 having an interior constriction 32 . The interior constriction 32 is sized so as to fit closely over the pipe 24 and serves to retain the gripper ring 14 , and insert 18 within the coupling body 12 when the coupling body 12 is screwed onto the stub 22 .
Located at an interface between the constricted section 28 and the intermediate section 30 is a gripper-constricting slope 34 which is an angled surface in the interior of the coupling body 12 formed as the interior diameter of the coupling body 12 expands from the interior constriction 32 to a gripper retainer groove 36 (discussed further below). This gripper-constricting slope 34 causes the gripper ring 14 to constrict around the pipe 24 once the coupling body 12 is tightened onto the stub 22 , as further discussed below. In the preferred embodiment, the angle of the gripper-constricting slope 34 is approximately 45 degrees though it is to be understood that other suitable angles may be utilized.
Adjacent the gripper-constricting slope 34 is the gripper retainer groove 36 which is an interior circumferential groove formed in the coupling body 12 and which has a sloped forward face 38 . The gripping retaining groove 36 retains the gripper ring 14 in place within the coupling body 12 .
Gripper Ring
As shown in FIGS. 5A and 5B , the gripper ring 14 is made of brass alloy and is an annular split ring.
In side cross-section, the radially exterior surface of the gripper ring 14 has a substantially horizontal central surface 40 with radially inwardly sloped surfaces 42 , 43 extending forwardly and rearwardly therefrom. In the preferred embodiment, the angle of the exterior sloped surfaces 42 , 43 is 25 degrees to the horizontal central surface 40 .
The exterior surface of the gripper ring 14 is shaped such that the gripper ring 14 will be retained within the gripper-retaining groove 36 of the coupling body 12 once it is inserted within, and such that movement of the gripper ring 14 rearwardly relative to the gripper-retaining groove 36 will cause the gripper ring 14 to constrict radially. Once inserted within the gripper-retaining groove 36 of the coupling body 12 , rearward movement of the gripper ring 14 is resisted by the rearward exterior sloped surface 43 of the gripper ring 14 abutting against the gripper-constricting slope 34 of the coupling body 12 . If the gripper ring is urged in a rearward direction within the gripper-retaining groove 36 , the rearward exterior sloped surface 43 of the gripper ring 14 slides along the gripper-constricting slope 34 causing the gripper ring 14 to constrict. Forward movement of the gripper ring 14 is resisted by the forward exterior sloped surface 42 of the gripper ring abutting against the sloped forward surface 38 of the gripper-retaining groove 36 of the coupling body 12 .
Still in side cross-section, the radially interior surface of the gripper ring 14 is shaped such that the interior of the gripper ring 14 has two annular gripping surfaces 44 separated by a central annular groove 46 . In other embodiments the gripper ring 14 may have three or more spaced gripping surfaces 44 . Additionally, to improve gripping strength, these annular gripping surfaces 44 may be provided with annular ridges or teeth.
The gripper ring 14 is also provided with a split 48 to allow radial constriction of the gripper ring 14 during insertion into the coupling body 12 and when gripping the pipe 24 .
Insert
As shown in FIG. 6 , the insert 18 is made of copper alloy and consists, moving from its forward end to its rearward end, of an inner web 62 , an annular rib 64 , an outer web 66 and a support tube 67 .
The inner web 62 is of a diameter smaller than the outer web 66 and its exterior surface is sized to fit closely within an inner surface of the stub 22 . The inner web also has on its outer surface a circumferential forward seal groove 68 shaped and sized to accommodate the forward seal 20 .
The annular rib 64 connects the inner web 62 , the outer web 66 and the support tube 67 , has a forward face 70 shaped to engage a rearward end face of the stub 22 , and a rearward face 72 shaped to engage a forward end face of the pipe 24 .
The outer web 66 is sized such that its outer surface closely fits within the coupling body 12 and its inner surface fits over the pipe 24 . A rearward face 73 of the outer web 66 is angled 45 degrees so as to engage the forward exterior sloped surface 42 of the gripper ring 14 .
The support tube 67 extends rearwardly from the inner web 62 and its exterior surface is sized to fit closely within an inner surface of the pipe 24 . The support tube 67 has on its exterior surface forwardly-oriented barbs 74 which serve to resist pull-out of the pipe 24 once the pipe 24 is inserted into the coupling 10 and the coupling 10 is tightened onto the stub 22 . The exterior surface of the support tube 67 also has a circumferential rearward seal groove 76 shaped and sized to accommodate the rearward seal 16 . An interior surface 77 of a rearward end of the support tube 67 is sloped outwardly so as to direct fluid flowing forwardly through the pipe 24 into the interior of the insert 18 .
Use
A description of an exemplary manner in which the preferred embodiment of the coupling of the present invention may be used is set out below.
First, the coupling body 12 , and the gripper ring 14 are assembled into a coupling body assembly. To do so, the gripper ring 14 is slid into the forward end of the coupling body 12 . This step can be performed either manually, or using an insertion device and is facilitated by the split 48 in the gripper ring 14 . The gripper ring 14 is pushed into the coupling body 12 until it is positioned within the gripper retaining groove 36 on the interior surface of the coupling body 12 art which point the resiliency of the gripper ring 14 causes it to expand to seat within the gripper retaining groove 36 . Once in this position, extraction of the gripper ring 14 from the coupling body 12 is resisted by abutment of the forward exterior sloped surface 42 of the gripper ring 14 against the sloped forward surface 38 of the gripper-retaining groove 36 of the coupling body 12 . Thus, once the gripper ring 14 is positioned within the coupling body 12 as described, the gripper ring 14 is held in place and will not fall out under normal handling.
The assembly of the coupling body 12 and gripper ring 14 may be performed at the factory such that the user receives a preassembled unit, or the user may assemble these elements just prior to use. Once the coupling body 12 and the gripper ring 14 are assembled into an assembled coupling body, the only remaining loose part of the coupling 10 is the insert 18 which comes preassembled with the forward seal 20 and the rearward seal 16 mounted thereon.
At a work site, the forward end of the pipe 24 is cut so that the end is square. The inside of the pipe 24 is then optionally bevelled with a reaming tool so that the pipe 24 can slide over the support tube 67 of the insert 18 easily.
Next, the insert 18 is inserted into the fitting stub 22 such that the inner web 62 of the insert 18 resides within the end of the stub 22 . The insert 18 is slid into the stub 22 until the rearward end face of the stub 22 engages the forward face 70 of the annular rib 64 of the insert 18 . In this position, the forward seal 20 creates a seal against the stub 22 thereby preventing leakage of fluid out the forward end of the coupling 10 .
The coupling body assembly is then placed over the insert 18 such that the forward end of the coupling body 12 slides over the outer web 66 of the insert 18 until the internal threading 31 of the nut section 26 of the coupling body 12 first engages the exterior threading 33 of the stub 22 . The coupling body 12 is then hand-tightened onto the stub 22 , thereby further engaging the interior threading 31 of the coupling body 12 and the exterior threading 33 of the stub 22 , and moving the coupling body 12 further over the insert 18 and the stub 22 . Typically, the coupling body 12 is hand-tightened onto the stub 22 until the rearward face 73 of the outer web 66 of the insert 18 abuts against the forward exterior sloped surface 42 of the gripper ring 14 thereby creating some resistance to further tightening.
The pipe 24 is then “stab-fitted” over the support tube 67 of the insert 18 and into the rearward opening of the coupling body 12 . The pipe 24 is pushed forward until the forward end face of the pipe 24 abuts against the rearward face 72 of the annular rib 64 of the insert 18 .
The coupling body 12 is then further tightened onto the stub 22 either by hand or by using a tool. Because the stub 22 , the insert 18 , the gripper ring 14 and the interior constriction 32 of the coupling body 12 all abut against one another, this further tightening causes the gripper ring 14 to move rearwardly to accommodate the decreasing distance between the rearward face 73 of the outer web 66 of the insert 18 and the gripper-constricting slope 34 . As it does so, cooperation between the rearward exterior sloped surface 43 of the gripper ring 14 and the gripper constricting slope 34 of the coupling body 12 causes the gripper ring 14 to be urged inwardly and to constrict, thereby resulting in an engagement of the outer surface of the pipe 24 by the gripping surfaces 44 of the gripper ring 14 . Further tightening of the coupling body 12 onto the stub 22 causes the gripping surfaces 44 of the gripper ring 14 to engage the outer surface of the pipe 24 more securely.
The configuration of the gripper ring 14 enhances gripping strength of the coupling 10 while reducing the potential for damage to, and/or collapse of the pipe 24 . First, the axial separation of the two gripping surfaces 44 provides stability to the gripper ring 14 as it is pressed against the pipe 24 . Second, by having two spaced gripping surfaces 44 , the pressure exerted by the coupling 10 on the gripper ring 14 is spread over a wider area on the pipe thereby reducing the likelihood of the gripper ring 14 causing damage to and/or collapse of the pipe 24 . Third, by having the central annular groove 46 between the two gripping surfaces 44 , a space is created for the pipe material to extrude slightly into this central annular groove 46 as the gripping surfaces 44 press into the pipe 24 thereby improving the gripping capacity of the coupling 10 . Although the number of gripping surfaces 44 can be three or greater, the preferred number is two so as to concentrate the inward force on the pipe 24 onto two annular regions, and preferably directly over the rearward seal 16 .
Additionally, as the coupling body 12 is tightened onto the stub 22 , an inward force is imparted to the pipe 24 thereby causing the pipe 24 to press against both the barbs 74 and the rearward seal 16 . Movement of the barbs 74 and rearward seal 16 inwardly is resisted by the rigidity of the support tube 67 of the insert 18 . In this manner the rearward seal 16 creates a seal between the support tube 67 and the pipe 24 preventing leakage out the rearward end of the coupling 10 . Additionally, the barbs 74 bite into the pipe 24 assisting in preventing inadvertent pull-out of the pipe 24 .
Once the forward flat face 35 of the nut section 26 of the coupling body 12 abuts the rearward face 37 of the shoulder 39 of the stub 22 , the coupling 10 is fully engaged and a sealed, secured connection between the pipe 24 and the stub 22 has been established. As designed, an ideal seal and securement is established by the coupling 10 when the coupling body 12 is fully tightened onto the nut with the forward flat face 35 of the nut section 26 of the coupling body abutting the rearward face 37 of the shoulder 39 of the stub 22 . Thus, it is easy for a user to tell if the coupling 10 is under-tightened, and it is not possible for the coupling 10 to be over-tightened.
To release the connection, the coupling body 12 is unscrewed from the stub 22 thereby disengaging the gripper ring 14 from the pipe 24 . The coupling body assembly can then be removed from the stub 22 and the pipe 24 can be slid out of the coupling body assembly.
Because none of the elements of the preferred embodiment coupling has been permanently deformed during use, the coupling 10 can then be reused.
Although an exemplary manner of using the preferred embodiment coupling of the present invention has been described above in detail, it is to be understood that the preferred embodiment coupling can be used in ways other than as explicitly set out above, as readily understood by those skilled in the art. For example, instead of mounting the insert 18 within the stub 22 first and placing the assembled coupling body over the insert 18 , the insert 18 can be placed within the coupling body assembly first and then the coupling body assembly with insert 18 within may be placed onto the stub 22 . As a further example, the pipe 24 may be inserted into the coupling body assembly first before the insert 18 is installed in the coupling body 12 , or before the coupling body assembly is placed over the insert 18 and stub 22 .
Although the preferred embodiment coupling has been described above as being used to attach a polyethylene pipe 24 to a fitting, it is to be understood that pipes made of other materials may be used. Indeed any pipe having sufficient rigidity to avoid excessive deformation during tightening and which has a surface soft enough to permit the gripper ring 14 to bite into it, may be used.
Specific materials used for the various elements of the coupling 10 and for the fitting stub 22 have been provided. However, it is to be understood that other suitable materials may be used for these elements as will be understood by those skilled in the art.
Very specific geometries of the various elements have also been provided. However, it is to be understood that persons skilled in the art may use other suitable geometries without necessarily departing from the scope of the invention.
The preferred embodiment coupling has also been described in the context of a waterworks application. However, it is to be understood that the coupling can be used in other applications, plumbing applications for example.
Numerous modifications and variations of the present invention are possible in light of the above teachings. It is therefore to be understood that within the scope of the appended claims, the invention may be practised otherwise than as specifically described herein. | A coupling for creating a fluid-conducting connection between a pipe and a stub, where the stub has no pipe-supporting extension over which the pipe is to be connected. The coupling includes a coupling body having a forward end for being secured to the stub, a rearward end for receiving the pipe, and an internal bore therethrough; stub connection for securing the forward end of the coupling body to the stub; a pipe support for providing internal support for an end section of the pipe being engaged by the coupling; gripper engaging means for causing the gripper to grip the pipe; a seal between the stub and the pipe; and a gripper located within the internal bore of the coupling body, the gripper and the coupling body configured to engage the pipe with the gripper when the stub is secured in the stub connection. | 5 |
BACKGROUND OF THE INVENTION
[0001] 1. Field of Invention
[0002] The present invention relates generally to a stabilizer for motorcycles during transport and, more specifically, to a device for assisting a motocross competitor in the storage and transport of the motorcycle in an enclosed trailer. In particular, the device comprises a stabilizer of steel tubing that is bolted or welded together to form an adjustable support frame attached to the ceiling of an enclosed trailer and having a telescopic arm which is suspended from the support frame and which engages and supports the motorcycle in an upright, transport position while leaving the floor and areas of the trailer adjacent the motorcycle free from obstructing objects.
[0003] 2. Background
[0004] The sport of motocross has become a well-recognized activity for many adventure seekers. Problems arise, however, in reaching racetracks or courses at far distances because motorcycles used in motocross are not typically licensed for highway use. Thus, a device for transporting the motorcycles becomes necessary. When using trailers for transporting motorcycles the owners traditionally utilize grounded devices such as wheel chocks, bike shoes, tie downs, and the like in order to stabilize the motorcycle in the trailer during travel.
[0005] One drawback to the traditional means of securing motorcycles with grounding devices is that the devices used consume the floor space in the trailer. For people entering and exiting the trailer the traditional means are not easy to maneuver around nor do they provide flexibility in storing other articles. Accordingly, a need exists for a device that allows the motorcycle owner to store the motorcycle with ease while giving better flexibility for storage and better maneuverability in the trailer.
SUMMARY OF THE INVENTION
[0006] An object of the invention comprises providing a device for stabilizing a motorcycle, where the ceiling mounted device with telescopic arm provides for better storage and maneuverability inside the enclosed trailer.
[0007] These and other objects of the present invention will become apparent to those skilled in the art upon reference to the following specifications, drawings, and claims.
[0008] The present invention intends to overcome the difficulties encountered heretofore. To that end, the stabilizer for a motorcycle comprises a mounted support frame that attaches to the ceiling of a trailer. A telescopic arm is pivotally connected to and extends downwardly from a forward portion of the support frame. A cross arm is then secured at a central location to the free end of the telescopic arm, the two arms thereby forming a general “T” shape. A pair of hooked extensions are attached to the cross arm, one at each end portion thereof. A strap associated with each hooked extension is used to releasably secure each hooked extension to a corresponding end of the handlebars of the motorcycle. Finally, a brace interconnects the telescopic arm with the rearward end of the support frame at an acute angle to provide additional support.
BRIEF DESCRIPTION OF THE DRAWINGS
[0009] [0009]FIG. 1 is a perspective view of a stabilizer mounted to a ceiling of a trailer while supporting a motorcycle.
[0010] [0010]FIGS. 2A and 2B are an upper perspective view of the support frame of the present invention and an enlarged view of an alternative attachment structure, respectively.
[0011] [0011]FIG. 3 is a side view of the support frame showing the brace arm, and part of the suspended telescopic arm.
[0012] [0012]FIG. 4 is a front view of the telescopic arm and base, including the hooked extensions that attach to the motorcycle.
[0013] [0013]FIG. 5A is a front view of an adapter for trailers with curved ceilings and FIG. 5B is a side view exploded to show the connection between adaptor and the support frame.
[0014] [0014]FIG. 6 is a side view of an extension of the telescopic arm for taller or shorter motorcycles.
[0015] [0015]FIG. 7 is a close-up view of a bolt block that is attached to the ends of the support frame and secure the support frame to the ceiling trusses.
DETAILED DESCRIPTION OF THE INVENTION
[0016] In the drawings, FIG. 1 shows a motorcycle stabilizer 50 of the present invention, comprising a support frame 10 that is mounted to ceiling trusses 52 of an enclosed trailer (not shown) and used to support a motorcycle 53 . In particular, FIG. 2A illustrates the support frame 10 as an adjustable rectangular support frame 10 comprised of steel tubing and divided into two U-shaped sub-frames 96 and 98 . The U-shaped sub-frames 96 and 98 are each comprised of two side legs 12 and 14 or 18 and 20 that are connected to a third end leg 16 or 22 (respectively) to form a first U-shaped sub-frame 98 and a second U-shaped sub-frame 96 , the two sub-frames joining to form the rectangular support frame 10 . The legs 18 and 20 of the first sub-frame 98 are made of small diameter steel tubing and are intended to telescope into the larger diameter legs 12 and 14 of the second sub-frame 96 , and are inserted into the corresponding legs 12 and 14 to create a rectangle support frame 10 of adjustable length. A locking bolt 24 is located on the outside of each side leg 12 and 14 and is used to secure the connection between the corresponding side legs 12 and 18 , and 14 and 20 . The locking bolt 24 is comprised of a nut 94 welded to a hole (not shown) drilled in the steel tubing and a bolt 74 capable of turning into the nut 94 so that the bolt 74 may be tightened in order to prevent the support frame 10 from opening or closing once in position.
[0017] [0017]FIG. 2A illustrates one means for mounting the support frame 10 to the ceiling trusses 52 (FIG. 1) of the trailer. This embodiment utilizes pin blocks 32 a - 32 d welded onto the end of each side leg 12 , 14 , 18 , and 20 of the support frame 10 . The pin blocks 32 a - 32 d are formed by securing a mounting pin 90 to a block 92 , and the pin block 32 is fit into the open end of the steel tubing of the side legs 12 , 14 , 18 , and 20 of the support frame 10 . The pin blocks 32 are used to mount the support frame 10 onto the ceiling trusses 52 of the trailer wherein the pins 90 are inserted into corresponding holes (not shown) drilled through the ceiling trusses 52 and are secured with cotter pins 34 that attach to protruding ends of the pin blocks 32 . A second embodiment, illustrated in FIG. 2B, uses L-shaped brackets 28 for mounting the support frame 10 to the ceiling trusses 52 . The L-shaped brackets 28 are attached to each corner of the support frame 10 , in particular they are attached to the side of the steel tubes at the ends of the side legs 12 , 14 , 18 , and 20 . Holes (not shown) are drilled through the ceiling trusses 52 of the trailer and the support frame 10 is mounted to the ceiling trusses 52 by connecting the support frame 10 with a bolt and nut combination 30 to the corresponding holes in the ceiling trusses 52 .
[0018] A telescoping arm 36 is suspended from the second U-shaped sub-frame 96 at the front of the support frame 10 , as shown in FIG. 3. The telescoping arm 36 is assembled from two telescoping pieces of steel tubing, the pieces of tubing comprising a first tubing section 38 and a second tubing section 46 , each section having a first end and a second end. The first end of the first tubing section 38 is pivotally attached to the support frame 10 by a U-shaped bracket 76 , best illustrated in FIG. 2A, that is secured to the end leg 16 of the support frame 10 . In this instance the U-shaped bracket 76 points downward and has holes 84 that are drilled to receive a nut and bolt combination 78 in order to secure the first tubing section 38 of the telescoping arm 36 by insertion through the holes 84 of the U-shaped bracket 76 when the first tubing section 38 , having corresponding holes in the first end, is positioned in the middle of the U-shaped bracket 76 . The second end of the first tubing section 38 is releasably secured to the second end of the second tubing section 46 . The second tubing section 46 is inserted into the first tubing section 38 and the two are telescoped and secured with the use of a second locking bolt 25 . A cross arm 44 is perpendicularly attached at a central location to the free end of the telescoping arm 36 , the connection forming an inverted T-shaped end.
[0019] Shown in FIG. 4, the cross arm 44 of the telescoping arm 36 has a pair of hook extensions 54 and 56 , one hook extension 54 and 56 located at each end of the cross arm 44 . The hook extensions 54 and 56 secure the motorcycle to the motorcycle stabilizer 50 and are composed of long steel tubing 58 having steel angles bent to form the hook ends 60 which are welded to each piece of long steel tubing 58 . The hook extensions 54 and 56 , with the welded hook ends 60 , slide into the ends of the cross arm 44 , and provide adjustability for different sized motorcycles by sliding the hook extensions 54 and 56 to the desired width position. A locking bolt 26 is installed on the top of each end of the cross arm 44 and is used to tighten and lock the adjustment. A strap 64 , preferably made out of hook and loop fastening material, is installed on each of the extension hooks 54 and 56 by sewing a loop into the strap 64 . These straps 64 are wrapped and self-locked around the handlebars of the motorcycle, and further wrapped around the front brake on the last rotation to lock the motorcycle into position.
[0020] A brace 70 attaches the telescoping arm 36 to the support frame 10 (FIG. 3). The brace 70 is adjustable in length and extends between the end leg 22 of the support frame 10 and an intermediate location on the telescoping arm 36 for positioning the telescoping arm 36 as necessary for the varying motorcycle models and sizes. The brace 70 is formed of two pieces of steel tubing having different diameters, a large tube 66 and a small tube 68 . The small tube 68 is inserted into the large tube 66 and is secured by a wing nut 72 located on the large tube 66 , which acts like a locking bolt with an easy to use grip placed over the bolt for quickly releasing the tension in and re-positioning the brace 70 .
[0021] The first end of the large tube 66 is pivotally attached to a U-shaped bracket 77 on the end leg 22 of the support frame 10 . The first end of the large tube 66 is positioned in the middle of the U-shaped bracket 76 and pivotally secured by inserting a bolt 75 through the corresponding holes 85 of the U-shaped bracket 76 and the first end of the large tube 66 , thus forming a pivot point. The second end of the large tube 66 accepts the first end of the small tube 68 , the connection allowing for telescoping of the brace 70 . The free end of the small tube 68 is pivotally attached to the telescoping arm 36 by inserting a bolt 78 through aligned holes in an attachment bracket 80 having spaced-apart ears between which the second end of the small tube 68 is received. The bracket 80 is piece welded at an intermediate position to each side of the first large tubing section 38 of the telescoping arm 36 . The two pivotal attachments of the brace 70 and the telescoping movement of the large tube 66 and the small tube 68 form an angle of support that is adjusted by telescoping the large and small tubes 66 and 68 of the brace 70 as necessary for the motorcycle to be properly stabilized.
[0022] Changes may be made to the preferred embodiment described above, making it available to a wider variety of potential users owning different types of trailers or motorcycles of different heights. FIGS. 5A and 5B illustrate an alternative embodiment of an adapter for a curved ceiling. In the standard mounting support frame 10 , each end of the main support frame 10 is attached to the flat trailer ceiling by bolt blocks 32 acting like pins inserted into holes drilled on the inner sides of the ceiling trusses 52 . In an alternative embodiment for use with trailers having curved ceilings, two backing plate assemblies 102 are attached to the ceiling trusses 52 for mounting opposite ends of the support frame 10 . The tubing assemblies 102 each include a plate 106 having a curved upper side portion and a flat lower side portion. A pair of stub legs 112 are secured by weldments or the like at the outer corners of the plate 106 adjacent the flat lower side portion and extend laterally away from the plate 106 . The stub legs 112 are formed of square tubing that is sized to be received in the open end portions of the side legs 12 , 14 , 18 , and 20 . The motorcycle stabilizer 50 is mounted to the ceiling trusses 52 by a nut and bolt combination 108 . Alternatively, a strap 110 may be used to strengthen the attachment of the stabilizer to the ceiling trusses 52 wherein three nut and bolt combinations are used to secure the strap 110 to the trusses 52 . If desired, the upper curved portion of the plate 106 could be cut to match the ceiling curvature of an enclosed trailer.
[0023] [0023]FIG. 6 illustrates another alternative embodiment of the device. An extension 128 is provided to the telescoping arm 36 to accommodate motorcycles or trailers of different heights. The extension 128 comprises a first unit 130 having a larger diameter and a second unit 132 having a smaller diameter and inserted into the first unit 130 , the two units 130 and 132 welded together. A locking bolt 134 is located at the end of the first unit 130 for telescoping with the second tubing section 46 . To use the extension 128 , the second tubing section 46 is removed from the first tubing section 38 and the second unit 132 of the extension 128 is telescoped into the first tubing section 38 of the telescoping arm 36 . The second tubing section 46 is inserted into the first unit 130 of the extension 128 , allowing the telescoping arm 36 to have a greater length to use with different sized motorcycles or with trailers of different heights.
[0024] An alternative to the pin blocks 32 (FIG. 2A) is illustrated generally at 132 in FIG. 7. Instead of a pin 90 , a bolt 190 is used and a nut (not shown) is threaded on the bolt 190 to secure the frame 10 to the ceiling trusses 52 .
[0025] Typically, ceiling trusses 52 of a trailer run transversely of the trailer (FIG. 1) and permit positioning of the stabilizer 50 at any desired position transversely of the trailer between any pair of trusses. A further alternative embodiment of the present invention comprises the use of a pair of parallel tracks mounted on the ceiling of the trailer perpendicular to the ceiling trusses 52 . The tracks are spaced apart by the width of the frame 10 . Clamps or other suitable means are used to attach the frame to the tracks at any desired position along the tracks. The tracks, accordingly, provide unlimited longitudinal adjustability of the position of the stabilizer 50 in the trailer within the length of the tracks.
[0026] Further, while the motorcycle stabilizer 50 has been described as including a frame that is rectangular, having a pair of parallel sides, an alternative embodiment comprises only a single mounting element, secured at either end to the ceiling trusses 52 and which supports the telescoping arm 36 in the same manner described above.
[0027] In the preferred embodiment illustrated in FIG. 2A, side legs 12 and 14 of support frame 10 consist of steel tubing of 1″ width and cut to a length of 16″. These arms are welded to the end leg 16 , which is composed of 1″ width steel tubing of 6″ length, forming the fist half of the U-shaped sub-frame 96 . The support frame 10 also includes the second U-shaped sub-frame 98 , with side legs 18 and 20 consisting of steel tubing of ¾″ width and 12″ length, and the end leg 22 of 1″ width steel tubing, 6″ in length. The support frame 10 creates a rectangle of adjustable length measuring 8″×18″ closed, with an overlap of 13″. The support frame 10 can be opened to the maximum position of 8″×28″ to hold a motorcycle of approximately 225 to 300 lbs without bending the ceiling trusses 52 or collapsing the support frame 10 . The ceiling trusses 52 of the trailer, however, limit the weight support capability.
[0028] With the main support frame 10 complete, the bolt blocks 32 a - 32 d attached to the ends of the side legs 12 , 14 , 18 , and 20 slip into a ⅜″ hole on the inner sides of the trusses 52 . On the end leg 16 the steel arms of the U-shaped bracket 76 are each 1½″×1″ and welded 1″ apart on center. The other second U-shaped bracket 76 on the end leg 22 also has steel arms sized at 1½″×1″ and welded 1″ apart on center.
[0029] In FIG. 3, the telescoping arm 36 is composed of the second tubing section 40 , the tubing measuring ¾″×12″ and the first tubing section 38 tubing measuring 1″×12.″ The nut 94 at the end of the 1″ diameter tubing is either ¼″ or ⅜″ in size The cross arm 44 is composed of a 16″ length piece of 1″ diameter steel tubing. The holes drilled on the ends of the cross arm 44 tubing are drilled halfway and ¼″ nuts 94 are welded to these holes.
[0030] Holes are drilled completely through ½″ on center on top of the 1″×12″ end of the large tube 66 of the brace 70 . The pivotal attachment is created by inserting a ⅜″ bolt 78 through the U-shaped bracket 76 . The two pieces of bent stock 80 are welded approximately 2½″ down from the angle of support hinge 82 on the telescoping arm 36 . The bend in the two pieces of bent stock 80 goes from a 1″ tube to a ¾″ tube in the hinge area. The small tube 68 of the brace 70 is composed of ¾″×16″ steel tubing and the large tube 66 is composed of 1″×16″ steel tubing.
[0031] In FIG. 4, the extension arms 54 and 56 are comprised of extension tubes 58 each being ¾″×8″ lengths of steel tubing and hooks 60 which are made from ½″ steel angles. The set bolts 62 installed into the welded nuts 94 on each end of the extension arms 54 and 56 are the size ¼″ or ⅜″.
[0032] In FIG. 5, for the alternative embodiment of the adapter, the two backing plates 102 and 104 are measured at ⅛″×12″×1″ and the legs 112 and 114 are composed of ¾″ width and 4″ length steel tubing. Similarly, legs 118 and 120 are composed of ½″ width and 4″ length steel tubing. A ⅜″ bolt 74 with nut and washer combination is utilized to mount 106 and 108 to the backing plates 102 and 104 .
[0033] In FIG. 6, for the alternative embodiment of the extension 128 the first unit 130 is composed of 1″ diameter steel tubing at a length of 12″, and the second unit 132 is composed of ¾″ diameter steel tubing at a length of 12″. Thus, the extension 128 gives an actual increase in length of 20″ to the motorcycle stabilizer 50 . The extension 128 can actually be produced to give an actual increase in length of 10″ by replacing the first unit 130 and the second unit 132 with 6″ lengths of steel tubing, using the same method of assembly.
[0034] The foregoing description and drawing comprises an illustrative embodiment of the present invention. The foregoing embodiments and the methods described herein may vary based on the ability, experience, and preference of those of ordinary skill in the art. Merely listing the steps of the method in a certain order does not constitute any limitation on the order of the steps of the method. The foregoing description and drawings merely explain and illustrate the invention and the invention is not limited thereto except insofar as the claims are so limited. It is anticipated that those of ordinary skill in the art with this disclosure before them will be able to make modifications in variations therein without departing from the scope of the invention. | A stabilizing device for supporting a motorcycle in a storage and transport position inside an enclosed trailer. A support frame is attached to the ceiling trusses of the trailer. A telescopic arm extends downward from the support frame to connect to a cross arm including hooks and straps that attach to the motorcycle to secure the motorcycle in place. A strengthening brace is interconnected between the opposite side of the support frame and an intermediate position on the telescopic arm. | 1 |
BACKGROUND OF THE INVENTION
(a) Field of the Invention
The invention relates to an enzyme linked immunosorbent assay (ELISA) kit for the rapid determination of N-acetyltransferase (NAT2) phenotype which can be used on a routine basis in a clinical laboratory, and which allows a physician to: a) individualize therapy of drugs such as amrinone, procainamide, amonafide, dapsone, isoniazid, trimethoprim-sulphamethoxazole (TMP-SMX) and b) to predict susceptibility to carcinogen induced diseases such as bladder and colonrectal cancers.
(b) Description of Prior Art
The fate of drugs (or xenobiotics) administered to humans is generally their metabolism in the liver into a form less toxic and lipophilic with their subsequent excretion in the urine. Their metabolism involves two systems which act generally consecutively: the cytochrome P450 system which includes at least 20 enzymes catalyzing oxidation reactions and localized in the microsomal fraction, and the conjugation system which involves a set of at least five enzymes. An enzyme of one system can act on several drugs and drug metabolites. The rate of metabolism of a drug may differ between individuals and between ethnic groups, owing to the existence of enzymatic polymorphism within each system. Two phenotypes can be distinguished: poor metabolizers (PM) and extensive metabolizers (EM). Knowledge of the phenotype is useful clinically because: a) the phenotype is associated with toxicities in chemical plants, diseases and cancers; b) it allows to prescribe a drug regimen on the individual basis; c) it provide a rationale in the design of therapeutic drugs. Currently, the phenotype is determined by measurements of the ratio of two metabolites of the drug or a probe drug in urine samples by high pressure liquid chromatography (HPLC) or capillary electrophoresis (CE), hence using methods which are not readily available in a clinical laboratory.
N-Acetylation Polymorphism
Individuals are genetically polymorphic in their rate of N-acetylation of drugs via the N-acetyltransferase (NAT2) pathway (Meyer, U. A. (1994) Proc. Natl. Acad. Sci. USA, 91:1983-1984). Two major metabolic phenotypes can be distinguished: fast and slow N-acetylators. Drugs that are subject to N-acetylation polymorphism include sulfonamides (sulfamethazine), antidepressants (phenelzine), antiarrhymics (procainamide), and antihypertensives (hydrazine). Some adverse therapeutic consequences of the acetylator phenotype are peripheral neurophathy and hepatitis. In an opposite manner, the N-acetylation of procainamide produces a therapeutically active metabolite with reduced toxicity. N-acetylation polymorphism has also been linked to detoxification pathway of some environmental carcinogenic arylamines and there is a higher frequency of bladder cancers among chemical dye workers who are slow N-acetylators.
Inter ethnic Differences
The frequency of PM and EM (autosomal recessive trait) show considerable inter ethnic differences for the N-acetylation polymorphism. In Caucasians, the frequencies are approximately 60 and 40%, while in Orientals, they are 20 and 80% (Meyer, U. A. (1994) Proc. Natl. Acad. Sci. USA, 91:1983-1984). It is reasonable that, in drug metabolism studies, each ethnic group be studied separately for evidence of polymorphism and its antimode should not be extrapolated from one ethnic population to another
Amonafide
A recent sample of the importance of phenotyping in drug management for chemotherapy is amonafide (Ratain, M. J. et al. (1993) Cancer Research, 53:2804-2808). Amonafide is a new site-specific intercalating, antineoplastic agent which is converted to an active metabolite by way the N-acetyltransferase (NAT2) pathway. Studies have shown a direct correlation between toxicity and the acetylator phenotype, with rapid acetylators at greater risk to problems of severe toxicity. However, some cytotoxicity is necessary for therapeutic benefit. Therefore, knowing the patient's acetylator phenotype can aid the physician in designing a drug regimen which balances efficacy and toxicity.
HIV-infected patients
Slow acetylators have an increased risk of cutaneous hypersensitivity to multiple drugs that are metabolized by acetylation, including sulfonamides and dapsone (Carr, A. et al. (1994) AIDS, 8:333-337). Hypersensitivity to trimethoprim-sulphamethoxazole (TMP-SMX) is more common in patients with HIV infection. It has been demonstrated that patients with HIV disease have an increased prevalence of the slow acetylator phenotype (90%). Thus, knowledge of their acetylator phenotype in the use of this particular drug.
Individualized Therapy
As is well known that it is possible to individualize therapy for a large number of drugs (theophylline, digoxin, aminoglycosidases, etc.). However, individualization of therapy has been extremely slow to develop because the methods used for drug phenotyping involves high pressure liquid chromatography (HPLC) and capillary electrophoresis (CE), which are costly, time consuming, and require expertise not readily applicable in a clinical laboratory.
It would be highly desirable to be provided with a method for determining an individual's N-acetylation phenotyping using non-toxic drug so as to predict his/her response and side effect profile to a wide range of potentially toxic drugs.
It would be highly desirable to be provided with an enzyme linked immunosorbent assay (ELISA) kit for N-acetyltransferase (NAT2) phenotyping which could be accomplished on routine basis by any technicians with a minimum of training and does not involve complex equipments.
It would be highly desirable to be provided with an ELISA kit which would enable a physician to individualize therapy of drugs such as amrinone, procainamide, amonafide, dapsone, isoniazid, trimethoprim-sulphamethoxazole (TMP-SMX).
SUMMARY OF THE INVENTION
One aim of the present invention is to provide a method for determining an individual's N-acetylation phenotyping using a non-toxic drug so as to predict his/her response and side effect profile to a wide range of potentially toxic drugs.
Another aim of the present invention is to provide an enzyme linked immunosorbent assay (ELISA) kit for the rapid determination of N-acetyltransferase (NAT2) phenotype which can be used on a routine basis in a clinical laboratory.
Another aim of the present invention is to provide an ELISA kit which allows a physician to: a) individualize therapy of drugs such as amrinone, procainamide, amonafide, dapsone, isoniazid, trimethoprim-sulphamethoxazole (TMP-SMX) and b) to predict susceptibility to carcinogen induced diseases such as bladder and colonrectal cancers.
BRIEF DESCRIPTION OF THE DRAWINGS
FIG. 1 illustrates the synthetic routes for the production of AAMU and 1X derivatives used in accordance with one embodiment of the present invention;
FIGS. 2, 3, 4, and 5 show other AAMU and 1X derivatives which can be used for raising antibodies in accordance with another embodiment of the present invention;
FIG. 6 illustrates the absorbance competitive antigen ELISA curves of AAMU-Ab and 1X-Ab in accordance with one embodiment of the present invention; and
FIG. 7 is an histogram of molar ratio of AAMU/1X.
DETAILED DESCRIPTION OF THE INVENTION
Different probe drugs can be used to determine the NAT2 phenotype (Kilbane, A. J. et al. (1990) Clin. Pharmacol. Ther., 47:470-477; Tang, B-K. et al. (1991) Clin. Pharmacol. Ther., 49:648-657). In accordance with the present invention caffeine is the preferred probe because it is widely consumed and relatively safe (Kalow, W. et al. (1993) Clin. Pharmacol. Ther., 53:503-514). In studies involving this probe, the phenotype has been generally determined from ratios of the caffeine metabolites 5-acetamino-6-amino-1-methyluracil (AAMU) or 5-acetamino-6-formylamino-1-methyluracil (AFMU) and 1-methyxanthine (1X). In these studies, the subjects are given an oral dose of a caffeine-containing substance, and the urinary concentrations of the target metabolites determined by HPLC (Kilbane, A. J. et al. (1990) Clin. Pharmacol. Ther., 47:470-477; Tang, B-K. et al. (1991) Clin. Pharmacol. Ther., 49:648-657) or CE (Lloyd, D. et al. (1992) J. Chrom., 578:283-291).
The number of clinical protocols requiring the determination of NAT2 phenotypes is rapidly increasing and in accordance with the present invention, an enzyme linked immunosorbent assay (ELISA) was developed for use in these studies (Wong, P., Leyland-Jones, B., and Wainer, I. W. (1995) J. Pharm. Biomed. Anal., 13:1079-1086). ELISAs have been successfully applied in the determination of low amounts of drugs and other antigenic components in plasma and urine samples, involve no extraction steps and are simple to carry out.
In accordance with the present invention, antibodies were raised in animals against two caffeine metabolites 5-acetamino-6-amino-1-methyluracil (AAMU) or 5-acetamino-6-formylamino-1-methyluracil (AFMU) and 1-methyl xanthine (1X)! present in urine samples of an individual collected after drinking coffee. Their ratio provides a determination of an individual's N-acetylation (NAT2) phenotype. Subsequently, there was developed a competitive antigen enzyme linked immunosorbent assay (ELISA) for measuring this ratio using these antibodies.
The antibodies of the present invention can be either polyclonal antibodies or monoclonal antibodies raised against two different metabolites of caffeine, which allow the measurement of the molar ratio of these metabolites.
In accordance with the present invention, the molar ratio of caffeine metabolites is used to determine the acetylation phenotype of the individual as follows. Individuals with a ratio less than 1.80 are slow acetylators.
Materials and Methods
Materials
Cyanomethylester,isobutyl chloroformate, dimethylsulfate, sodium methoxide, 95% pure, and tributylamine were purchased from Aldrich (Milwaukee, Wis., USA); horse radish peroxidase was purchased from Boehringer Mannheim (Montreal, Que., Canada); corning easy wash polystyrene microtiter plates were bought from Canlab (Montreal, Que., Canada); o-methylisourea hydrochloride was obtained from Lancaster Laboratories (Windham, N.H., USA); alkaline phosphatase conjugated to goat anti-rabbit IgGs was from Pierce Chemical Co. (Rockford, Ill., USA); bovine serum albumin fraction V initial fractionation by cold alcohol precipitation (BSA), complete and incomplete Freund's adjuvants, diethanolamine, 1-methyxanthine, p-nitrophenol phosphate disodium salt, o-phenylenediamine hydrochloride; porcine skin gelatin, rabbit serum albumin (RSA); Sephadex™ G25 fine, Tween™ 20 and ligands used for testing antibodies cross reactivities were obtained from Sigma Chemical Co. (St. Louis, Mo., USA). Whatman™ DE52 diethylaminoethyl-cellulose was obtained from Chromatographic Specialties Inc. (Brockville, Ont., Canada). Dioxane was obtained from A&C American Chemicals Ltd. (Montreal, Que., Canada) and was refluxed over calcium hydride for 4 hours and distilled before use. Other reagents used were of analytical grade.
Synthetic procedures
The synthetic route for the production of AAMU-hemisuccinic acid (VIII) and 1-methyxanthine-8-propionic acid (IX) is presented in FIG. 1.
Synthesis of 2-methoxy-4-imino-6-oxo-dihydropyridine (III)
Compound III is synthesized according to the procedure of Pfeiderer (Pfeilderer, W. (1957) Chem. Ber., 90:2272-2276) as follows. 12.2 g of o-methylisourea hydrochloride (110.6 mmol), 11.81 mL methylcyanoacetate (134 mmol), 12.45 g of sodium methoxide (230.5 mmol) and 80 mL of methanol are placed in a 250 mL round bottom flask. The suspension is stirred and refluxed for 5 hours at 68°-70° C. After cooling at room temperatute, the suspension is filtered through a sintered glass funnel (Pyrex, 40-60 ASTM, 60 mL), and the NaCl on the filter is washed with methanol. The filtrate is filtered by gravity through a Whatman™ no. 1 paper in a 500 mL round bottom flask, and the solvent is evaporated under reduced pressure with a rotary evaporator at 50° C. The residue is solubilized with warm distilled water, and the product is precipitatedd by acidification to pH 3-4 with glacial acetic acid. After 2 hours (or overnight) at room temperature, the suspension is filtered under vacuum through a sintered glass funnel (Pyrex, 40-60 ASTM, 60 mL). The product is washed with water, acetone, and dried. The product is recrystallized with water as the solvent and using charcoal for decolorizing (activated carbon, Norit r A<100 mesh, decolorizing). The yield is 76%.
Synthesis of 1-methyl-2-methoxy-4-imino-6-oxo-dyhydropyrimidine (IV)
Compound IV is synthesized according to the procedure of Pfeiderer (Pfeilderer, W. (1957) Chem. Ber., 90:2272-2276) as follows. 11 g of compound III (77.0 mmol) and 117 mL of 1N NaOH (freshly prepared) are placed in a 250-mL round bottomed flask. The solution is stirred and cooled at 15° C., using a water bath and crushed ice. 11.7 mL dimethylsulfate (123.6 mmol) are added dropwise with a pasteur pipette over a period of 60 min. Precipitation eventaully occurs upon the addition. The suspension is stirred at 15° C. for 3 hours and is left at 4° C. overnight. The product is recovered by filtration under vacuum through a sintered glass funnel (Pyrex, 40-60 ASTM, 60 mL). The yield is 38%.
Synthesis of 1-methyl-4-iminouracil (V)
Compound V was synthesized according to the procedure of Pfeiderer (Pfeilderer, W. (1957) Chem. Ber., 90:2272-2276) as follows. 11.26 g of compound IV (72.6 mmol) and 138 mL 12N HCl are placed in a 250-mL round bottom flask, and the suspension is stirred at room temperature for 16-20 hours. The suspension is cooled on crushed ice, the product is recovered by filtration under vacuum through a sintered glass funnel (Pyrex, 40-60 ASTM, 60 mL). The product is washed with water at 4° C., using a pasteur pipette, until the pH of filtrate is around 4 (about 150 mL). The product is washed with acetone and dried. The yield is 73%.
Synthesis of 1-methyl-4-imino-5-nitrouracil (VI)
Compound VI is synthesized according to the procedure of Lespagnol et al (Lespagnol, A. et al.(1970) Chim. Ther., 5:321-326) as follows. 6.5 g of compound V (46 mmol) and 70 mL of water are placed in a 250 mL round bottom flask. The suspension is stirred and refluxed at 100° C. 6.5 g sodium nitrite (93.6 mmol) is dissolved in 10 mL water and is added gradually to the reaction mixture with a pasteur pipette. 48 mL of glacial acetic acid is added with a pasteur pipette. Upon addition, precipitation occurs and the suspension becomes purple. The suspension is stirred and heated for an additional 5 min., and cooled at room temperature and then on crushed ice. The product is recovered by filtration under vacuum through a sintered glass funnel (Pyrex, 10-15 ASTM, 60 mL). It is washed with water at 4° C. to remove acetic acid and then with acetone. Last traces of acetic acid and acetone are removed under a high vacuum. The yield is 59%.
Synthesis of 1-methyl-4,5-diaminouracil (VII)
Compound VII is synthesized by the procedure of Lespagnol et al. (Lespagnol, A. et al.(1970) Chim. Ther., 5:321-326) as follows. Place 2 g of compound VI (11.7 mmol) and 25 mL water in a 100 mL round bottom flask. Stir the suspension and heat in an oil bath at 60° C. Add gradually 88% sodium hydrosulfite (40.4 mmol), using a spatula, until the purple color disappears (approximately 5 g or 24.3 mmol). Heat for an additional 15 min. Cool the flask on crushed ice and leave at 4° C. overnight. Recover the product by filtration under vacuum through a sintered glass funnel (Pyrex, 30-40 ASTM, 15 mL). Wash the product with water and acetone, and dried. Last traces of acetone are removed under a high vacuum. The yield is 59%.
Synthesis of AAMU-hemisuccinic acid (VIII)
0.30 g of compound VII (1.92 mmol) and 5 mL water are placed in a 20-mL beaker. The suspension is stirred and the pH is adjusted between 8 to 9 with a 3N NaOH solution. 0.33 g succinic anhydride (3.3 mmol) is added to the resulting solution, and the mixture is stirred until the succinic anhydride is dissolved. During this process, the pH of the solution is maintained between 8 and 9. The reaction is completed when all the succinic anhydride is dissolved and the pH remains above 8. The hemisuccinate is precipitated by acidification to pH 0.5 with 12N HCl. The product is recovered by filtration on a Whatman™ No. 1 paper, washed with water to remove HCl. It is then washed with acetone and dried.
Other AAMU or AFMU derivatives
The derivatives shown in FIGS. 2 and 3 can also be used for raising antibodies against AAMU or AFMU that can be used for measuring the concentrations of these caffeine metabolites in urine samples.
Synthesis of 1-methyxanthine-8-propionic acid (IX)
This product is synthesized according to a modified procedure of Lespagnol et al. (Lespagnol, A. et al.(1970) Chim. Ther., 5:321-326) as follows. 0.2 g of compound VIII (0.78 mmol) is dissolved in 2-3 mL of a 15% NaOH solution. The resulting solution is stirred at 100° C. until all of the solvent is evaporated, and is then maintained at this temperature for an additional 5 min. The resulting solid is cooled at room temperature, and dissolved in 10 mL water. The product is precipitated by acidification to pH 2.8 with 12N HCl. After cooling at 4° C. for 2.5 hours, the product is recovered by filtration on a Whatman™ No. 1 paper, washed with water and acetone, and dried. It is recrystallized from water-methanol (20:80, v/v), using charcoal to decolorize the solution.
Other derivatives of 1X
The other derivatives of 1X, shown in FIGS. 4 and 5, can also be used for raising antibodies against 1X and thereby to allow the development of an ELISA for measuring 1X concentration in urine samples.
Synthesis of AAMU
AAMU is synthesized from compound VII according to the procedure of Fink et al (Fink, K. et al. (1964) J. Biol. Chem., 249:4250-4256) as follows. 1.08 g of compound VII (6.9 mmol) and 20 mL acetic acid anhydride were placed in a 100-mL round bottom flask. The suspension is stirred and refluxed at 160°-165° C. for 6 min. After cooling at room temperature, the suspension is filtered under vacuum through a sintered glass funnel (Pyrex, 10-15 ASTM, 15 mL). The product is washed with water and acetone, and dried. The product is recrystallized in water.
NMR spectroscopy
1 H and 13 C NMR spectra of compounds VIII and IX are obtained using a 500 MHz spectrophotometer (Variant™ XL 500 MHz, Varian Analytical Instruments, San Fernando, Calif., USA) using deuterated dimethyl sulfoxide as solvent.
Conjugation of haptens to bovine serum albumin and rabbit serum albumin
The AAMU-hemisuccinic acid (VIII) and the 1-methyxanthine propionic acid (IX) are conjugated to BSA and RSA according to the following mixed anhydride method. Place 31.7 mg of compound VIII (0.12 mmol) or 14.9 mg of compound IX (0.06 mmol) in a 5-mL round bottom flask. Pipet 52.2 μL of tri-n-butylamine (0.24 mmol) and 900 μL of dioxane dried over calcium hydride and freshly distilled. Cool at 10° C. in a water bath using crushed ice. Pipet 12.6 μL isobutyl chloroformate at 4° C. (0.12 mmol, recently purchased or opened) and stir for 30-40 min at 10°-12° C. While stirring, dissolve 70 mg BSA or RSA (0.001 mmmol) with 1.83 mL water in a glass tube, add 1.23 mL dioxane freshly dried and distilled, and cool the BSA or RSA solution on ice. After 30-40 min of the above stirring, 70 μL of 1N NaOH solution cooled on ice is added to the BSA or RSA solution and the resulting solution is poured in one portion to the flask. Stir the solution at 10°-12° C. for 3 hours and dialyze against 1 liter water for 2 days at room temperature, with water changed twice a day. Determine the protein concentration of the conjugates and the amounts moles of AAMU or 1X incorporated moles of BSA or RSA by methods described below and store them as 1 mL aliquots at -20° C.
Protein determination by the method of Lowry et al (Lowry, O. H. et al. (1951) J. Biol. Chem., 193:265-275)
A) Solutions
Solution A: 2 g Na 2 CO 3 is dissolved in 50 mL water, 10 mL of 10% SDS and 10 mL 1 NaOH, water to 100 mL. Freshly prepared.
Solution B: 1% NaK Tartrate
Solution C: 1% CuSO 4 .5H 2 O
Solution D: 1N phenol (freshly prepared): 3 mL Folin & Ciocalteu's phenol reagent (2.0N) and 3 mL water.
Solution F: 98 mL Solution A, 1 mL Solution B, 1 mL Solution C. Freshly prepared.
BSA: 1 mg/mL. 0.10 g bovine serum albumin (fraction V)/100 mL.
B) Assay
______________________________________Standard curve Tubes # (13 × 100 mm)______________________________________Solution 1 2 3 4 5 6 7BSA (μL) 0 10 15 20 30 40 50Water (μL) 200 190 185 180 170 160 150Solution F (mL) 2.0 2.0 2.0 2.0 2.0 2.0 2.0Vortex and leave10 min atroom temperature.Solution D (μL) 200 200 200 200 200 200 200Vortex and leave atroom temperaturefor 1 hour.Read absorbance at750 mm using wateras the blank.______________________________________Unknown Tube # (13 × 100 mm)Solution D.F..sup.a 1 2 3______________________________________Unknown (μL) ? x x xWater (μL) y y y x + y = 200 μLSolution F (mL) 2.0 2.0 2.0Vortex and leave 10 minat room temperatureSolution D (μL) 200 200 200______________________________________
Vortex and leave 1 hour at room temperature Read absorbances at 750 nm using water as the blank. Calculate the protein concentration using the standard curve and taking account of the dilution factor (D.F.). a, D.F. (dilution factor). It has to be such so that the absorbance of the unknown at 750 nm is within the range of absorbance of the standards.
Method to determine the amounts of moles of AAMU or 1X incorporated per mole of BSA or RSA.
This method gives an approximate estimate. It is a useful one because is allow to determine whether the coupling as proceeded as expected.
A) Solutions
10% sodium dodecyl sulfate (SDS)
1% SDS solution
0.5 or 1 mg/mL of AAMU-BSA (or AAMU-RSA) in a 1% SDS solution (1 mL).
0.5 or 1 mg/mL of AAMU-BSA (or AAMU-RSA) in a 1% SDS solution (1 mL)
0.5 or 1 mg/mL of BSA or RSA in a 1% SDS solution (1 mL).
B) Procedure
Measure the absorbance of the AAMU conjugate solution at 265 nm, with 1% SDS solution as the blank.
Measure the absorbance of the BSA (or RSA) solution at 265 nm, with 1% SDS solution as the blank.
Calculate the amount of mole of AAMU incorporated per mole of BSA (or RSA) with this formula. ##EQU1## Where: y is the amount of mole of AAMU/mole of BSA (or RSA)
ε 265 (AAMU) is the extinction coefficient of AAMU=10 4 M -1 cm -1 .
BSA!=BSA (mg/mL)/68,000/mmole.
To calculate the amount of mole of 1x incorporated per mole of BSA or RSA, use the same procedure but with this formula. ##EQU2## Where: y is the amount of mole of 1X/mole of BSA (or RSA) ε 252 (AAMU) is the extinction coefficient of 1X=10 4 M -1 cm -1 .
BSA!=BSA (mg/mL)/68,000/mmole.
Coupling of haptens to horse radish peroxidase
The AAMU derivative (VIII) and 1X derivative (IX) are conjugated to horse radish peroxidase (HRP) by the following procedure. Place 31.2 mg of compund VIII (or 28.3 mg of compound IX) in a 5 mL round bottom flask. Pipet 500 μL of dioxane freshly dried over calcium chloride. Stir the suspension and cool at 10° C. using a water bath and crushed ice. Pipet 114 μL tributylamine and 31 μL of isobutyl chloroformate (recently opened or purchased). Stir for 30 min. at 10° C. While stirring, dissolve 13 mg of horse radish peroxidase (HRP) in 2 mL of water and cool the solution at 4° C. on crushed ice. After the 30 min. stirring, pipet 100 μL of a 1N NaOH solution at 4° C. to the HRP solution and pour the alkaline HRP solution at once in the 5 mL flask. Stir the suspension 4 hours at 10°-12° C. Separate the free derivative from the HRP conjugate by filtration on Sephadex G-25™ column (1.6×30 cm) equilibrated and eluted with a 0.05M sodium phosphate buffer, pH 7.5. Collect fractions of 1.0-1.2 mL with a fraction collector. During the elution two bands are observed: the HRP conjugate band and a light yellow band behind the HRP conjugate band. The HRP conjugate elutes between fractions 11-16. Pool fractions containing the HRP conjugate in a 15-mL tisssue culture tube with a screw cap. Determine the HRP conjugate concentration at 403 nm after diluting an aliquot (usually 50 μL+650 μL of buffer).
HRP-conjugate!(mg/mL)=A.sub.403 ×0.4×D.F.
Record the ultraviolet (UV) absorption spectrum between 320 and 220 nm. The presences of peaks at 264 and 270 nm for AAMU-HRP and 1X-HRP conjugates, respectively, are indicative that the couplings proceeded as expected.
After the above measurements, 5 μL of a 4% thiomersal solution is added per mL of the AAMU-HRP or 1X-HRP comjugate solution. The conjugates are stored at 4° C.
Antibody production
Four mature females New Zealand white rabbits (Charles River Canada, St-Constant, Que., Canada) were used for antibody production. The protocol employed in this study was approved by the McGill University Animal Care Committee in accordance with the guidelines from the Canadian Council on Animal Care.
An isotonic saline solution (0.6 mL) containing 240 mg of BSA conjugated antigen was emulsified with 0.6 mL of a complete Freund's adjuvant. 0.5 mL of the emulsion (100 mg of antigen) was injected per rabbit intramuscularly or subcutaneously. Rabbits were subsequently boosted at intervals of three weeks with 50 mg of antigen emulsified in incomplete Freund's adjuvant. Blood was collected by venipuncture of the ear 10-14 days after boosting. Antisera were stores at 4° C. in the presence of 0.01% sodium azide.
Double immunodiffusion in agar plate
An 0.8% agar gel in PBS was prepared in a 60×15 mm petri dish. Rabbit serum albumin (100 μL of 1 mg mL -1 ) conjugated to AAMU (or 1X) was pipetted in the center well, and 100 μL of rabbit anitiserum was pipetted in peripheral wells. The immunodiffusion was carried out in a humidified chamber at 37° C. overnight and the gel was inspected visually.
Antiserum titers
The wells of a microtiter plate were coated with 10 μg mL -1 of rabbit serum albumin-AAMU (or 1X) conjugate in sodium carbonate buffer, pH 9.6) for 1 hour at 37° C. (100 μL/per well). They were then washed three times with 100 μL TPBS (phosphate buffer saline containing 0.05% Tween™ 20) and unoccupied sites were blocked by an incubation with 100 mL of TPBS containing 0.05% gelatin for 1 hour at 37° C. The wells were washed three times with 100 μL TPBS and 100 μL of antiserum diluted in TPBS was added. After 1 hour at 37° C., the wells were washed three times with TPBS, and 100 μL of goat anti-rabbit IgGs-alkaline phosphatase conjugate diluted in PBS containing 1% BSA was added. After 1 hour at 37° C., the wells were washed three times with TPBS and three times with water. To the wells were added 100 μL of a solution containing MgCl 2 (0.5 mM) and p-nitrophenol phosphate (3.85 mM) in diethanolamine buffer (10 mM, pH 9.8). After 30 min. at room temperature, the absorbency was read at 405 nm with a micro-plate reader. The antibody titer is defined as the dilution required to change the absorbance by one unit (1 au).
Isolation of rabbit IgGs
The DE52-cellulose resin was washed three times with sodium phosphate buffer (500 mM, pH 7.50), the fines were removed and the resin was equilibrated with a sodium phosphate buffer (10 mM, pH 7.50). The resin was packed in a 50×1.6 cm column and eluted with 200-300 mL equilibrating buffer before use. To antiserum obtained from 50 mL of blood (30-32 mL) was added drop-wise 25-27 mL 100% saturated ammonium sulfate solution with a Pasteur pipette. The suspension was left at room temperature for 3 h and centrifuged for 30 min. at 2560 g at 20° C. The pellet was dissolved with 15 mL sodium phosphate buffer (10 mM, pH 7.50) and dialyzed at room temperature with the buffer changed twice per day. The dialyzed solution was centrifuged at 2560 g for 10 min. at 20° C. to remove precipitate formed during dialysis. The supernatant was applied to the ion-exchange column. Fractions of 7 mL were collected. After application, the column is eluted with the equilibrating buffer until the absorbance at 280 nm become less than 0.05 au. It is then eluted with the equilibrating buffer containing 50 mM NaCl. Fractions having absorbencies greater than 0.2 at 280 nm are saved and stored at 4° C. Protein concentrations of the fractions are determined as described above.
Competitive antigen ELISA
Buffers and water without additives were filtered through millipore filters and kept for 1 week. BSA, antibodies, Tween™ 20 and horse radish peroxidase conjugates were added to these buffers and water just prior to use. Urine samples were usually collected 4 hours after drinking a cup of coffee (instant or brewed with approximately 100 mg of caffeine per cup) and stored at -80° C. They were diluted 10 times with sodium phosphate buffer (620 mosm, pH 7.50) and were subsequently diluted with water to give concentrations of AAMU and 1X no higher than 3×10 -6 M in the ELISA. All the pipettings were done with an eight-channel pipette, except those of the antibody and sample solutions. Starting with the last well, 100 μL of a carbonate buffer (100 mM, pH 9.6) containing 2.5 μg mL -1 antibodies was pipetted. After 90 min. at room temperature, the wells were washed three times with 100 mL of TPB: isotonic sodium phosphate buffer (310 mosm, pH 7.50) containing 0.05% Tween™ 20.
After the initial wash, unoccupied sites were blocked by incubation for 90 min. at room temperature with 100 μL TPB containing 3% BSA. The wells were washed four times with 100 μL TPB. This was followed by additions of 50 mL of 12 mg mL -1 AAMU-HRP or 1X-HRP conjugate in 2×TPB containing 2% BSA, and 50 μL of either water, standard (13 standards; AAMU or 1X, 2×10 -4 to 2×10 -8 M) or sample in duplicate. The microplate was gently shaken with an orbital shaker at room temperature for 3-4 hours. The wells were washed three times with 100 μL with TPB containing 1% BSA and three times with water containing 0.05% Tween 20. To the washed plate was added 150 μL of a substrate buffer composed of citric acid (25 mM) and sodium phosphate dibasic buffer (50 mM, pH 5.0) containing 0.06% hydrogen peroxide and 0.04% o-phenylenediamine hydrochloride. After 20 min. at room temperature with shaking, the reaction was stopped with 50 μL of 2.5M HCl. After shaking the plate 3 min., the absorbances were read with a microtiter plate reader at 490 nm.
Results
Polyclonal antibodies against AAMU and 1X could be successfully raised in rabbits after their conjugation to bovine serum albumin. Each rabbit produced antibody titers of 30,000-100,000 as determined by ELISA. This was also indicated by strong precipitin lines after double immunodiffusion in agar plates of antisera and derivatives conjugated to rabbit serum albumin. On this basis, a) IgGs antibodies were isolated on a DE-52 cellulose colunmn and b) a competitive antigen ELISA for NAT2 phenotyping using caffeine as probe drug was developed according to the methods described in the above section entitled Materials and Methods.
Contrary to current methods used for phenotyping, the assay involves no extraction, is sensitive and rapid, and can be readily carried out on a routine basis by a technician with a minimum of training in a clinical laboratory.
The present invention will be more readily understood by referring to the following examples which are given to illustrate the invention rather than to limit its scope.
EXAMPLE I
A Competitive Antigen ELISA for NAT2 Phenotyping using Caffeine as a Probe Drug
Buffers and water without additives were filtered through millipore filters and kept for 1 week. BSA, antibodies, Tween™ 20 and horse radish peroxidase conjugates were added to these buffers and water just prior to use. Urine samples were usually collected 4 hours after drinking a cup of coffee (instant or brewed with approximately 100 mg of caffeine per cup) and stored at -80° C. They were diluted 10 times with sodium phosphate buffer (620 mosm, pH 7.50) and were subsequently diluted with water to give concentrations of AAMU and 1X no higher than 3×10 -6 M in the ELISA. All the pipettings were done with an eight-channel pipette, except those of the antibody and sample solutions. Starting with the last well, 100 μL of a carbonate buffer (100 mM, pH 9.6) containing 2.5 μg mL -1 antibodies was pipetted. After 90 min. at room temperature, the wells were washed three times with 100 mL of TPB: isotonic sodium phosphate buffer (310 mosm, pH 7.50) containing 0.05% Tween™ 20.
After the initial wash, unoccupied sites were blocked by incubation for 90 min. at room temperature with 100 μL TPB containing 3% BSA. The wells were washed four times with 100 μL TPB. This was followed by additions of 50 mL of 12 mg mL -1 AAMU-HRP or 1X-HRP conjugate in 2×TPB containing 2% BSA, and 50 μL of either water, standard (13 standards; AAMU or 1X, 2×10 -4 to 2×10 -8 M) or sample in duplicate. The microplate was gently shaken with an orbital shaker at room temperature for 3-4 hours. The wells were washed three times with 100 μL with TPB containing 1% BSA and three times with water containing 0.05% Tween 20. To the washed plate was added 150 μL of a substrate buffer composed of citric acid (25 mM) and sodium phosphate dibasic buffer (50 mM, pH 5.0) containing 0.06% hydrogen peroxide and 0.04% o-phenylenediamine hydrochloride. After 20 min. at room temperature with shaking, the reaction was stopped with 50 μL of 2.5M HCl. After shaking the plate 3 min., the absorbances were read with a microtiter plate reader at 490 nm.
The competitive antigen ELISA curves of AAMU-Ab and 1X-Ab determinations obtained in duplicate are presented in FIG. 6. Each curve represents triplicate determinations in a single run. The error bars represent standard deviations. For data point with no error bars, the error bars are less the size of the symbol. Under the experimental conditions of the ELISA: background was less than 0.10 au; the practical limits of detection of AAMU and 1X were 2×10 -7 M and 2×10 -6 M, respectively, concentrations 500 and 50 times lower than those in urine samples from previous phenotyping studies (Kilbane, A. J. et al. (1990) Clin. Pharmacol. Ther., 47:470-477); the intra-assay and interassay coefficients of variations of AAMU and 1X were 15-20% over the concentration range of 0.01-0.05 mM.
A variety of conditions for the ELISA were tested and a number of noteworthy observations were made: gelatin, which was used in the competitive antigen ELISA determination of caffeine in plasma (Fickling, S. A. et al. (1990) J. Immunol. Meth., 129:159-164), could not be used in our ELISA owing to excessive background absorbency which varied between 0.5 and 1.0 au; in the absence of Tween™ 20, absorbency changes per 15 min. decreased by a factor of at least 3, and calibration curves were generally erratic; absorbency coefficients of variation of samples increased by a factor of 3 to 4 when the conjugates and haptens were added to the wells as a mixture instead individually.
The cross reactivities of AAMU-Ab and 1X-Ab were tested using a wide variety of caffeine metabolites and structural analogs (Table 1 below). AAMU-Ab appeared highly specific for binding AAMU, while 1X-Ab appeared relatively specific for binding 1X. However, a 11% cross reactivity was observed with 1-methyluric acid (1U), a major caffeine metabolite.
TABLE 1______________________________________Cross-reactivity of AAMU-Ab and 1X-Ab towards differentcaffeine metabolites and structural analogs % Cross-ReactionCompound AAMU-Ab 1X-Ab______________________________________Xanthine .sup. 0.sup.a 0Hypoxanthine 0 01-Methyl Xanthine (1X) 0 1003-Methyl Xanthine 0 07-Methyl Xanthine 0 08-Methyl Xanthine 0 01,3-Dimethyl Xanthine (Theophylline) 0 0.21,7-Dimethyl Xanthine (Paraxanthine) 0 0.53,7-Dimethyl Xanthine (Theobromine) 0 01,3,7-Trimethyl Xanthine (Caffeine) 0 0Uric acid 0 01-Methyluric acid 0 111,7-Dimethyluric acid 0 0Guanine 0 0Uracil 0 05-Acetamino-6-amino-uracil 0.6 05-Acetamino-6-amino-1-methyluracil (AAMU) 100 05-Acetamino-6-amino-1,3-dimethyluracil 0 0______________________________________ .sup.a The number 0 indicates either an absence of inhibition or an inhibition no higher than 40% at the highest compound concentration teste in the ELISA (5 × 10.sup.-3 M); concentrations of 5acetamino-6-amino-1-methyluracil (AAMU) and 1Methyl Xanthine (1X) required for 50% inhibition in the competitive antigen ELISA were 1.5 × 10.sup.-6 M and 10.sup.-5 M, respectively.
The relative high level of cross reactivity of 1U is, however, unlikely to interfere significantly in the determination of 1X and the assignment of NAT2 phenotypes, since the ratio of 1U:1X is no greater than 2.5:1 in 97% of the population (Tang, B-K. et al. (1991) Clin. Pharmacol. Ther., 49:648-657). This is confirmed by measurements of apparent concentrations of 1X when the ratio varied between 0-8.0 at the fixed 1X concentration of 3×10 -6 M (Table 2 below). At 1U:1X ratios of 2.5 and 3.0, the apparent increases were 22% and 32%, respectively.
TABLE 2______________________________________The effect of the ratio 1U:1X on the determination of1X concentration by ELISA at fixed 1X concentrationof 3 × 10.sup.-6 M1U:1X ratio 1X! × 10.sup.6 (M)______________________________________0.0 3.000.50 2.751.00 3.251.50 3.252.00 3.602.50 3.653.00 3.954.00 4.205.00 4.306.00 4.508.00 4.30______________________________________
The following observations attested to the validity of the competitive antigen ELISA for NAT2 phenotyping.
1) The ELISA assigned the correct phenotype in 29 of 30 individuals that have been phenotyped by capillary electrophoresis (CE) (Lloyd, D. et al. (1992) J. Chrom., 578:283-291).
2) In the CE method, the phenotype was determined using AFMU/1X peak height ratios rather than the AAMU/1X molar ratios used in the ELISA. When the molar ratios determined by ELISA and the peak height ratios determined by CE were correlated by regression analysis, the calculated regression equation was y=0.48+0.87 x, with a correlation coefficient (r) of 0.84. Taking account that these two ratios are not exactly equal and that Kalow and Tang (Kalow, W. et al. (1993) Clin. Pharmacol. Ther., 53:503-514) have pointed out that using AFMU rather than AAMU can lead to misclassification of NAT2 phenotypes, there is a remarkable agreement between the two methods.
3) The ELISA was used in determining the NAT2 phenotype distribution within a group of 48 individuals (FIG. 7). This histogram was obtained with a group of 48 individuals (FIG. 7). Assuming an antimode of 1.80, the test population contained 60.4% slow acetylators and 39.6% fast acetylators. This is consistent with previously reported distributions (Kalow, W. et al. (1993) Clin. Pharmacol. Ther., 53:503-514; Kilbane, A. J. et al. (1990) Clin. Pharmacol. Ther., 47:470-477).
EXAMPLE II
Determination of 5-acetamino-6-amino-1-methyluracyl (AAMU) and 1-methyl xanhtine in Urine Samples with the ELISA Kit
TABLE 3______________________________________Content of the ELISA kit and conditions of storage StorageItem Unit State Amt conditions______________________________________Tween 20 1 vial Liquid 250 μL/vial 4° C.H.sub.2 O.sub.2 1 vial Liquid 250 μL/vial 4° C.AAMU-HRP 1 vial Liquid 250 μL/vial 4° C.1X-HRP 1 vial Liquid 250 μL/vial 4° C.Buffer A 4 vials Solid 0.8894 g/vial 4° C.Buffer B 6 vials Solid 1.234 g/vial 4° C.Buffer C 6 vials Solid 1.1170 g/vial 4° C.Buffer D 6 vials Solid 0.8082 g/vial 4° C.Plate(AAMU-Ab) 2 Solid -- 4° C.Plate(1X-Ab) 2 Solid -- 4° C.Buffer E 6 vials Solid 0.9567 g/vial -20° C.Standards 14 vials Liquid 200 μL -20° C.(AAMU)Standards(1X) 14 vials Liquid 200 μL -20° C.1N NaOH 1 bottle Liquid 15 mL 20° C.1N HCl 1 bottle Liquid 15 mL 20° C.______________________________________
Conversion of AFMU to AAMU
In order to determine the AAMU concentrations in urine samples by competitive antigen ELISA, a transformation of AFMU to AAMU is required.
Thaw and warm up to room temperature the urine sample.
Suspend the sample thoroughtly with the vortex before pipeting.
Pipet 100 μL of a urine sample in a 1.5 mL-microtube.
Pipet 100 μL of a 1N NaOH solution.
Leave at room temperature for 10 min.
Neutralize with 100 μL 1N HCl solution.
Pipet 700 μL of Buffer A (dissolve the powder of one vial A/50 mL).
Dilutions of Urine Samples for the Determinations of AAMU! and 1X! by ELISA
The dilutions of urine samples required for determinations of AAMU and 1X are a function of the sensitivity of the competitive antigen ELISA and AAMU and 1X concentrations in urine samples. It is suggested to dilute the urine samples by a factor so that AAMU and 1X concentrations are about 3×10 -6 M in the well of the microtiter plate. Generally, dilution factors of 100-400 and 50-100 have been used for AAMU and 1X, respectively.
TABLE 4______________________________________ Microtube #______________________________________Dilution Factor 20× 40× 50× 80× 100× 150× 200× 400×Solution 1 2 3 4 5 6 7 8Urine sample 500 250 200 125 100 66.7 50 25(mL).sup.a10 × dilutedBuffer B (mL) 500 750 800 875 900 933.3 950 975______________________________________ .sup.a Vortex the microtubes containing the urine sample before pipeting. Store the diluted urine samples at -20° C. in a styrofoam box for microtubes.
Buffer B: dissolve the content of one vial B/100 mL.
Determination of AAMU! and 1X! in Diluted Urine Samples by ELISA
Precautions
The substrate is carcinogenic. Wear surgical gloves when handling Buffer E (Substrate buffer). Each sample is determined in duplicate. An excellent pipeting technique is required. When this technique is mastered the absorbance values of duplicate should be within less than 5%. Buffers C, D and E are freshly prepared. Buffer E-H 2 O 2 is prepared just prior pipeting in the microtiter plate wells.
Preparation of samples:
Prepare Table 5 with a computer and print it. This table shows the content of each well of a 96-well microtiter plate. Enter the name of the urine sample (or number) at the corresponding well positions in Table 5. Select the dilution factor (D.F.) of each urine sample and enter at the corresponding position in Table 5. Enter the dilution of each urine sample with buffer B at the corresponding position in Table 5: for example, for a D.F. of 100 (100 μL of 10× diluted urine sample+900 μL buffer B), enter 100/900. See "Dilutions of urine samples . . ." procedure described above for the preparation of the different dilutions. Prepare the different dilutions of the urine samples in 1.5-mL microtubes using a styrofoam support for 100 microtubes. Prepare Table 6 with a computer and print it. Using a styrofoam support (100 microtubes), prepare the following 48 microtubes in the order indicated in Table 4.
TABLE 5______________________________________Positions of blanks, control and urine samples in amicrotiter plateSample Well # D.F Dil. Sample Well # D.F Dil.______________________________________Blank 1-2 - Control 49-50 -Control 3-4 - 7 51-52S1 5-6 - 9 53-54S2 7-8 - 10 55-56S3 9-10 - 11 57-58S4 11-12 - 12 59-60S5 13-14 - 13 61-62S6 15-16 - 14 63-64S7 17-18 - 15 65-66S8 19-20 - 16 67-68S9 21-22 - 17 69-70 S10 23-24 - Control 71-72 - S11 25-26 - 18 73-74 S12 27-28 - 19 75-76 S13 29-30 - 20 77-78 S14 31-32 - 21 79-80 S15 33-34 - 22 81-821 35-36 23 83-842 37-38 24 85-863 39-40 25 87-884 41-42 26 89-905 43-44 27 91-926 45-46 28 93-947 47-48 Blank 95-96 -______________________________________
TABLE 6______________________________________Content of the different microtubesTube # Sample Content Tube # Sample Content______________________________________1 Blank Buffer B 25 7 Dil. Urine2 Control Buffer B 26 8 Dil. Urine3 S1 AAMU or 1X 27 9 Dil. Urine4 S2 AAMU or 1X 28 10 Dil. Urine5 S3 AAMU or 1X 29 11 Dil. Urine6 S4 AAMU or 1X 30 12 Dil. Urine7 S5 AAMU or 1X 31 13 Dil. Urine8 S6 AAMU or 1X 32 14 Dil. Urine9 S7 AAMU or 1X 33 15 Dil. Urine10 S8 AAMU or 1X 34 16 Dil. Urine11 S9 AAMU or 1X 35 17 Dil. Urine12 S10 AAMU or 1X 36 Control Buffer B13 S11 AAMU or 1X 37 18 Dil. Urine14 S12 AAMU or 1X 38 19 Dil. Urine15 S13 AAMU or 1X 39 20 Dil. Urine16 S14 AAMU or 1X 40 21 Dil. Urine17 S15 AAMU or 1X 41 22 Dil. Urine18 1 Dil. Urine 42 23 Dil. Urine19 2 Dil. Urine 43 24 Dil. Urine20 3 Dil. Urine 44 25 Dil. Urine21 4 Dil. Urine 45 26 Dil. Urine22 5 Dil. Urine 46 27 Dil. Urine23 6 Dil. Urine 47 28 Dil. Urine24 Control Buffer B 48 Blank Buffer B______________________________________
Solutions:
Buffer C: dissolve the content of one vial C/50 mL. Pipet 25 mL of Tween 20.
Buffer D: dissolve the content of one vial D/25 mL. Pipet 25 mL of Tween 20.
0.05% Tween 20: Pipet 25 μL of Tween 20 in a 100-mL erlnemeyer flask containing 50 mL of water.
2.5N HCl: 41.75 mL of 12N HCl/200 mL. Store in a 250-mL glass bottle.
AAMU-HRP conjugate: Pipet 9 mL of Buffer C in a 15-mL glass test tube. Pipet 90 μL of AAMU-HRP stock solution.
1X-HRP conjugate: Pipet 9 mL of the 2% BSA solution in a 15-mL glass test tube. Pipet 90 μL 1X-HRP stock solution.
Buffer E-H 2 O 2 : Dissolve the content of one vial E-subtrate/50 ml water. Pipet 25 μL of a 30% H 2 O 2 solution (prepared just prior pipeting in the microtiter plate wells).
TABLE 7______________________________________Standard solutions of AAMU and 1X(diluted with buffer B)AAMU 1XStandard AAMU! Standard 1X!______________________________________1 1.12 × 10.sup.-4 M 1 2.00 × 10.sup.-4 M2 6.00 × 10.sup.-5 M 2 1.12 × 10.sup.-4 M3 3.56 × 10.sup.-5 M 3 6.00 × 10.sup.-5 M4 2.00 × 10.sup.-5 M 4 3.56 × 10.sup.-5 M5 6.00 × 10.sup.-6 M 5 2.00 × 10.sup.-5 M6 3.56 × 10.sup.-6 M 6 1.12 × 10.sup.-5 M7 2.00 × 10.sup.-6 M 7 6.00 × 10.sup.-6 M8 1.12 × 10.sup.-6 M 8 3.56 × 10.sup.-6 M9 6.00 × 10.sup.-7 M 9 2.00 × 10.sup.-6 M10 3.56 × 10.sup.-7 M 10 1.12 × 10.sup.-6 M11 2.00 × 10.sup.-7 M 11 6.00 × 10.sup.-7 M12 1.12 × 10.sup.-7 M 12 3.56 × 10.sup.-7 M13 6.00 × 10.sup.-8 M 13 2.00 × 10.sup.-7 M14 3.56 × 10.sup.-8 M 14 1.12 × 10.sup.-7 M15 2.00 × 10.sup.-8 M 15 6.00 × 10.sup.-8 M______________________________________
Conditions of the ELISA
Pipet 50 μL/well of AAMU-HRP (or 1X-HRP) conjugate solution, starting from the last row. Pipet 50 μL/well of diluted urine samples in duplicate, standards, blank with a micropipet (0-200 μL), starting from well #96 (see Table 5). Cover the plate and mix gently by vortexing for several seconds. Leave the plate at room temperature for 3 h. Wash 3 times with 100 μL/well with buffer C, using a microtiter plate washer. Wash 3 times with 100 μL/well with the 0.05% tween 20 solution. Pipet 150 μL/well of Buffer E-H 2 O 2 (prepared just prior pipeting in the microtiter plate wells). Shake 20-30 min at room temperature with an orbital shaker. Pipet 50 μL/well of a 2.5N HCl solution. Shake 3 min with the orbital shaker at room temperature. Read the absorbance of the wells with microtiter plate reader at 490 nm. Print the sheet of data and identify properly the data sheet.
Calculation of the AAMU! and 1X! in Urine Samples from the Data
Draw a Table 5 with a computer. Using the data sheet of the microtiter plate reader, enter the average absorbance values of blanks, controls (no free hapten present), standards and samples in Table 6. Draw the calibration curve on a semi-logarithmic plot (absorbance at 490 nm as a function of the standard concentrations) using sigma plot (or other plot software). Find the AAMU! (or 1X!) in the microtiter well of the unknown from the calibration curve and enter the data in Table 6. Multiply the AAMU! (or 1X!) of the unknown by the dilution factor and enter the result in the corresponding case of Table 6.
TABLE 8______________________________________Composition of the different bufferBuf- Concen. P!fer pH Composition (mM) (mM)______________________________________A 7.50 0.15629 g/100 mL NaH.sub.2 PO.sub.4 11.325 71.424 1.622 g/100 mL Na.sub.2 HPO.sub.4.7H.sub.2 O 60.099 1.778 g/100 mL (total weight)B 7.50 0.1210191 g/100 mL NaH.sub.2 PO.sub.4 8.769 49.999 1.11309 g/100 mL of Na.sub.2 HPO.sub.4. 41.23 7H.sub.2 O 1.2341 g/100 mL (total weight)C 7.50 1 g/100 mL of BSA -- 0.1210191 g/100 mL of NaH.sub.2 PO.sub.4 8.769 49.999 1.11309 g/100 mL of Na.sub.2 HPO.sub.4. 41.23 7H.sub.2 O 2.2341 g/100 mL (total weight)D 7.50 2 g/100 mL of BSA 0.1210191 g/100 mL of NaH.sub.2 PO.sub.4 8.769 49.999 1.11309 g/100 mL of Na.sub.2 HPO.sub.4. 41.23 7H.sub.2 O 3.2341 g/100 mL (total weight)E 5.00 0.52508 g/100 mL of citric acid 25 -- 1.34848 g/100 mL of Na.sub.2 HPO.sub.4. 50 7H.sub.2 O 40 mg/100 mL of o-phenylene- diamine hydrochloride 1.913567 g/100 mL (total weight)______________________________________
While the invention has been described in connection with specific embodiments thereof, it will be understood that it is capable of further modifications and this application is intended to cover any variations, uses, or adaptations of the invention following, in general, the principles of the invention and including such departures from the present disclosure as come within known or customary practice within the art to which the invention pertains and as may be applied to the essential features hereinbefore set forth, and as follows in the scope of the appended claims. | The invention relates to an enzyme linked immunosorbent assay (ELISA) kit for the rapid determination of N-acetyltransferase (NAT2) phenotype which can be used on a routine basis in a clinical laboratory. The ELISA kit allows physicians to: a) individualize therapy of drugs such as amrinone, procainamide, amonafide, dapsone, isoniazid, trimethoprim-sulphamethoxazole (TMP-SMX) and b) to predict susceptibility to carcinogen induced diseases such as bladder and colon rectal cancers. | 8 |
BACKGROUND OF THE INVENTION
1. Field of the Invention
The invention relates to methods and apparatus for processing multimedia messages. More particularly, the invention relates to methods and apparatus for (1) converting messages from one medium to another; (2) performing message content analysis; (3) utlizizing linguistically based analysis tools to identify message relationships regardless of media type; (4) interrelating messages according to content; and (5) providing a simple message reference capability to simplify message access.
2. Brief Description of the Prior Art
Business people receive many different kinds of messages, e.g. electronic mail, voice mail, fax, video messages, attachments to electronic mail. It is possible and desirable to have all messages sent to a single mail box from which they may all be retrieved regardless of the message type. However, the only retrieval device which is capable of reading all of these different types of messages is a personal computer having a graphical display and audio video capability. Unfortunately, it is not always possible or convenient to retrieve messages with a personal computer.
A unified mailbox where all kinds of media (voice, fax, e-mail, and video) are made accessible and/or visible from virtually anywhere to a subscriber or user in one basket is a convenient means of communication when compared to handling multiple mailboxes with distinct media. Current solutions for a unified mailbox are inefficient, however, for someone with an intense communication style and a frequent need to handle his/her messages remotely. The mismatch of media type of the information and the capabilities of the various (often limited) devices used for remote access places a heavy burden on the user and the interface of the system. This is especially true for the interfaces utilizing a telephone with no display, or handheld devices with limited display capabilities.
Some of the problems arise in the context of compound and/or lengthy messages in connection with one or the other access means. For example, it is not possible to deliver voice and fax messages to a text-only e-mail capable device. It is also difficult to deal with lengthy e-mails delivered to a voice-only interface or to a text-interface with limited capabilities. Even when the device has a fully functional GUI interface, there is room for increased efficiency with large amounts of data. It is a challenge to efficiently present the information in various office document formats (e.g., Word Processor, Spreadsheet, and Presentations) associated with a message. It is often difficult to locate and visually present related messages and attachments. When the mailbox has many messages in it, it is difficult to reference the messages.
Other problems arise due to the increased amount of information the unified mailbox can provide. Current mechanisms for organizing and presenting relationships among messages (listing by arrival time, subject, sender, etc.) are insufficient for a large number of messages of varying media and, especially, mixed media within a given message.
It would be desirable to provide a flexible, media independent way of finding and navigating related messages. With current systems, for example, the user is unable to recognize that there is a relationship between a voice message and a fax without listening to the voice message and displaying/printing the fax.
Because the presentation of unified mailbox information is more complex, especially if relationships as described hereinabove are incorporated into the presentation, identifying an individual item (message or message attachment) for further action can become problematic. How does the client/user identify to the server which message is to be acted upon? Are the entire message and its attachments to be involved? Is it a single attachment or only the original message body? And if the messages are presented in a “graph” format, how does the user select an individual item?
Current unified mailbox systems offer media sensitivity for message retrieval only when accessed with a graphical user interface (GUI) from a PC client. If a particular media or office document is attached to an e-mail, the user needs to click-on it in order to launch a specific application, for example, an audio player for voice, tiff-viewer for fax, video player to view a video message, etc.
For users with intense communication requirements (e.g. executives or customer service agents who receive hundreds of compound messages daily) there are no means to quickly process inbox messages except by the sender information, the subject line, and maybe few lines of the message body. In order to read messages, the user has to click on or mark a certain item in a graphical interface in order to get to the message body.
No content summarization of lengthy text messages or respective attachments is available yet that would remarkably improve the efficiency of handling the daily information avalanche in the office.
Current mailbox searching does not provide visual display of content and temporal relationships. No search capability exists yet for non-text messages.
If a unified mailbox is accessed from a telephone interface, voice and e-mail messages are retrievable and the user can listen to both. Existing text-to-speech technology provides a means to convert the e-mail to voice. A fax message can be forwarded to a fax machine or printer.
However, if an e-mail contains an attachment, the systems are able to indicate that, but are unable to access its content. Similarly, the contents of a fax or other documents attached to an e-mail are indicated but not accessible to the user accessing the mailbox with a telephone interface.
If an e-mail is lengthy, the user may be able to navigate through it by accelerating the text-to-speech reading speed. However, there is no means of text content summarization applied to shorten the process without eventually losing/skipping critical content.
If messages are forwarded to a handheld device via a wireless service but the device has limited text-display capabilities only certain parts of the email (From, Subject and a limited number of characters of the message body) can be displayed. If the critical information in the message is not in the beginning of the message body that is displayed, it is “lost” to the recipient. He/she has to use other access methods or make a call into the messaging system/server to retrieve the full text message (by listening to it or by initiating a printing to a device nearby).
As mentioned above, voice and other media attachments are indicated but not transmitted and/or displayed on a text-only display. The user needs to use other access methods to retrieve the messages. Additionally, no text content summarization methods are utilized to deal with access device technology limitations.
Full message sensitivity is only provided when accessing a mailbox with a multimedia PC. However even multimedia PCs lack any means to summarize message content in order to make it more efficient for the recipient to read his/her lengthy messages. Also, there are yet no means to summarize content of attached documents.
When accessing a mailbox with a telephone, the media and device sensitivity is limited to voice and e-mail. Again, no techniques of text content summarization are applied yet in order to make the retrieval of the message information over the phone more convenient.
In the case of handheld or mobile devices with limited text-display capabilities, the problem is that lengthy messages are usually not transmitted in their entirety by the wireless/paging service providers. Additionally, any other media attachments are “lost”. No content summarization of lengthy text messages or respective attachments is available yet that would remarkably improve the efficiency of handling the daily information avalanche in the office.
SUMMARY OF THE INVENTION
It is therefore an object of the invention to provide methods and apparatus for accessing multimedia messages from a unified mailbox.
It is also an object of the invention to provide methods and apparatus for converting media types in a unified multimedia mailbox.
It is another object of the invention to provide methods and apparatus for summarizing the content of messages in a unified multimedia mailbox.
It is yet another object of the invention to provide methods and apparatus for cross referencing related messages based on content.
It is another object of the invention to provide methods and apparatus for improved handling of email attachments.
It is still another object of the invention to provide methods and apparatus for customizing mail handling based on a system profile adapted to the device used to access the mailbox.
In accord with these objects which will be discussed in detail below the apparatus and associated methods of the invention include a mail server that provides multimedia message inbox for one or several users on a network; a subsystem that detects media attachments to messages in a mailbox; a subsystem that converts media attachments into another media type using text-to-speech, fax-to-text, video voice track into text and speech-to-text; a subsystem that analyzes and summarizes the text content of original or converted media in respect of the linguistic meaning; a subsystem that delivers appropriate media according to an access device and message purpose, as defined in a profile; a subsystem that identifies cross-media interrelationships between messages and controls the media conversions necessary for this analysis; and a subsystem that controls a reference number scheme.
The methods and apparatus of the invention solve the problems discussed above by utilizing advanced media conversion methods, analysis and summarization of message content, and intelligent forwarding concepts. It provides access device and media sensitive intelligence for a mailbox when retrieving or forwarding a particular message.
The concept of media conversion is extended beyond text-to-speech to other attachments; a speaker-independent, large vocabulary, telephony-quality speech recognition engine is utilized to convert a voice message to text or to convert the voice track of a video attachment into readable text. Similarly, fax information is converted into text.
According to the invention, the content of messages is automatically summarized. The summarization of a message content is an improvement toward efficiency, particularly in the case of a forwarded lengthy message to a handheld device with limited display capabilities. The same is true for reading a lengthy message over the phone. Summarization is also applied to attached media (e.g. fax, Word document) extends even the media content accessible.
Both, the media conversion and the content summarization applied together provide compatibility with the access device. Depending on the user, the types of potential access devices are usually predefined; therefore messages along with their attachments that form the message content can be tailored to those devices while accessed or forwarded according to a profile. This ensures the availability of more information to the recipient at the device of choice and that is probably most convenient. Still, if the user requires more information, he/she can utilize another access method.
The invention also provides cross-media searching and visual displaying. Often messages related to a specific topic of interest to the user are in different media and spread throughout the message store (e.g. in different folders). The cross-media search finds these messages and presents them to the user in a way that makes the content and time relationships clear allowing efficient use of the otherwise overwhelming amount of information. The search engine utilizes sophisticated linguistically based analysis tools to discover the message relationships.
Additionally, a reference number scheme for all messages is provided. All messages in a particular group reference number to be used in further actions. Thus a PDA user can, for example, get a summary of messages with reference numbers and an indication of the message type. This reference number may then be used to access that message, and through it, a particular attachment to that message for further. Voice commands may be used to invoke actions on items more efficiently using the reference numbers of messages.
BRIEF DESCRIPTION OF THE DRAWINGS
FIG. 1 is a high level block diagram of a multimedia mail system according to the invention.
DETAILED DESCRIPTION
Turning now to FIG. 1 , an integrated multimedia messaging system according to the invention includes a mail server 10 that provides multimedia message inbox for one or several users on a network; a mail processor 11 ; a subsystem 12 that detects media attachments to messages in a mailbox; one or more subsystems that converts media attachments into another media type using text-to-speech 14 , fax-to-text 16 , video voice track into text 18 and speech-to-text 20 a subsystem 22 that analyzes and summarizes the text content of original or converted media in respect of the linguistic meaning; a subsystem 24 that delivers appropriate media according to an access device and message purpose, as defined in a profile; a subsystem 26 that identifies cross-media interrelationships between messages and controls the media conversions necessary for this analysis; and a subsystem 28 that controls a reference number scheme.
The invention can better be understood through an illustrative example such as the notification of a single-media voice message to a data pager. The following describes an example of this process involving a user that has a multimedia mailbox and a data pager who receives a voice message.
The problem is to provide the “best” information to the pager so the user can proceed most efficiently. What is the “best” information will vary according to the user's actual preferences, but will most likely include sender identification and meaningful portions of the message itself. In addition, there are probably messages the user would prefer to delay any handling of until an appropriate device is available. Thus the steps for sending voice messages to a pager would include: a) filtering messages to be processed, b) speech-to-text conversion, c) summarization and post filtering, and d) selection and delivery of text information to the device.
Since the resources involved in processing a message may be large, messages are pre-filtered. Speech-to-Text is “expensive” in its use of resources. Interrupting the user with any but the most important messages can be an unnecessary expense of the user's time and attention as well as a waste of system resources. Thus a mechanism to prevent the presentation of a message to a given device is important. This filtering is based on a variety of data including sender, message priority, etc. and the criteria for filtering is stored in the system profile for the user.
Voice messages which pass through the pre-filter are converted to text. This is most efficiently accomplished on the server side, perhaps with a dedicated “helper” server explicitly for the server so as not to disturb other processing on the server. The resulting text message is then be associated with the original message (as the text message body or as a separate attachment).
Before sending the text message to the pager, it is subjected to post-conversion filtering and summarization. Post-conversion filtering is optional, preventing processing of messages that appear not to be on a topic deemed important to the user. If it does not appear important, it would then remain in the mailbox to be processed. If the message survives the post-conversion filtering step, the text is then summarized.
Most simply, summarization includes reduction to a list of keywords and phrases found within the text. The summarization is created by removing from the message words/phrases not found within the user-defined list of keywords/phrases. More complex summarization includes allowing the user to specify the keyword/phrase list based on the sender of the message.
Since the message is a speech-to-text conversion, the keywords and their homonyms should be checked. An option on the summarization, for example a check box that says “allow homonyms”, could be utilized to enable this feature.
Even more complex summarization methods contemplated by the invention involve performing sophisticated grammatical parsing and analysis.
Data is transmitted to the pager based on a user defined data selection criteria which is stored as a template in the system profile for the user. The data available for selection includes sender same, time, summary, message priority, un-summarized text, and other fields as available.
The user describes a template that indicates the information desired and the number of characters of each field desired. For example:
“From %SENDER% at %TIME%: %100SUMMARY%”
indicates that the user wants a string that includes the entire sender name, the received time and the first 100 characters of the summary to appear on his pager.
When the user receives the page, the summary information gives him/her enough information to determine how critical the message is. If it appears critical, he/she may choose to access the entire message using a different device, e.g. a telephone.
Another example is the retrieval of text messages (such as email) via a telephone. Text messages are pre-filtered as described above. The text is then summarized. The summary is then converted to speech which is played on the telephone to the user calling in for messages.
Still another example is sending a fax message to a PDA. Fax messages are pre-filtered based on sender and priority. The fax messages which pass through the filter are converted to text with OCR (optical character recognition) software. The text is summarized. Data is selected using a user defined template. The text message is sent tot he PDA and the user is “notified”.
In general, a user can define a “morphing process” for messages in the context of any particular target device such as a pager or a cell phone with a limited display.
The morphing process is a combination of message filtering, message restructuring, data conversion, data summarization, data selection and notification steps that are configured to handle particular media types for particular target devices. Each user may define a set of rules and parameters for each device type defining how messages are morphed.
For example, a user may have a Voice Message-to-Pager morph definition that would do the following:
(a) filter messages based on sender and priority, removing from further processing (i.e. leaving on the server) messages that are not deemed urgent enough to disturb the user while out of the office; (b) perform speech-to-text conversion; (c) summarize the text based on criteria defined by the user; (d) perform further filtering based on the summarized/converted text; (e) organize the text in a template; and (f) send the message to the pager.
In general, a morphing process will include these steps in some order determined by the user. In addition, message restructuring steps allow the user to handle multiple attachments of varying media attached to the message. For example, the user may select that a summary of the attachments be created (attachment name and media type) or may request that the attachments be expanded, converted and summarized as described above for the single media message.
There have been described and illustrated herein methods and apparatus for processing multimedia messages. While particular embodiments of the invention have been described, it is not intended that the invention be limited thereto, as it is intended that the invention be as broad in scope as the art will allow and that the specification be read likewise. It will therefore be appreciated by those skilled in the art that yet other modifications could be made to the provided invention without deviating from its spirit and scope as so claimed. | The invention provides the user of a unified messaging mailbox with efficient, intelligent, media and device sensitive methods and apparatus to access and process (e.g., read, listen, forward, and search) messages. The invention introduces media conversion capabilities to selectively treat multimedia messages and message attachments so that they can be efficiently handled by mobile devices like PDAs (Personal Digital Assistants), pagers, or phone devices (with or without a text display feature). Furthermore, the invention introduces message content analysis capabilities that will recognize linguistic relationships between messages regardless of the media type. The invention also describes the ability to present these linguistic relationships along with the standard messaging relationships (Message arrival time, subject, sender, etc.). Still further, the invention introduces a message referencing option that allows simpler message selection from certain devices. | 7 |
BACKGROUND OF THE INVENTION
This invention relates to ink jet printers, and, more particularly, to a printer wherein the colorant reservoir on the print head may be refilled during normal operation.
Printers are devices that print characters onto a printing medium such as a sheet of paper or a polyester film. Printers of many types are available, and are commonly controlled by a computer that supplies the images, in the form of text or figures, that are to be printed.
Some printers use a colorant-containing liquid, which may be an ink or a dye, but is often termed an "ink" or "liquid toner" in the printer industry, to form the images on the printing medium. (By contrast, other printers use a dry toner to form the image.) Such printers deliver the colorant to the medium using a print head that creates the proper patterning of colorant to permanently record the image.
One type of printer is the ink jet printer, which forms small droplets of colorant that are ejected toward the printing medium in a pattern of dots that form the images. When viewed at a distance, the collection of dots form the image in much the same manner that photographic images are formed in newspapers. Ink jet printers are fast, produce high quality printing, and are quiet, because there is no mechanical impact during formation of the image, other than the droplets of colorant striking the printing medium.
Typically, an ink jet printer has a large number of individual colorant-ejection nozzles in the print head, supported in a carriage and oriented in a facing, but spaced-apart, relationship to the printing medium. The carriage and supported print head traverse over the surface of the medium, with the nozzles ejecting droplets of colorant at appropriate times under command of the computer or other controller, to produce a swath of droplets. In the thermal ink jet printer, the ejection of droplets is accomplished by heating a volume of the colorant adjacent the nozzle with a resistor, thereby vaporizing a bubble of the colorant to drive the droplet toward the printing medium. The droplets strike the medium and then dry to form "dots" that, when viewed together, form one swath or row of the permanently printed image. The carriage is moved an increment in the direction lateral to the traverse (or, alternatively, the printing medium is advanced), and the carriage again traverses the page with the print head operating to deposit another swath. In this manner, the entire pattern of dots that form the image is progressively deposited by the print head during a number of traverses of the page. To achieve the maximum output rate, the printing is preferably bidirectional, with the print head ejecting colorant during traverses from left-to-right and right-to-left.
The colorant is stored in a reservoir that, for some types of printers, is mounted on the carriage adjacent the nozzles. Colorant is then delivered by capillary action to the nozzles for ejection. It is common for some printers that the print head is a single consumable and disposable unit, that may be readily inserted and removed from the printer when the colorant in the reservoir is exhausted or one or more of the nozzles malfunction.
In the early stages of the development of thermal ink jet printers, the useful life of the print head was usually established by the time until a nozzle failure occured. In some cases the colorant ejector system would become inoperable prior to depletion of the colorant in the reservoir. More recently, the design and manufacturing of the nozzles and associated apparatus of the print head have advanced, so that the life of the nozzles prior to failure is lengthened significantly. Thus, the reservoir's supply of colorant may be exhausted before nozzle failures are experienced. There now exists a need for a larger supply of colorant available for ejection.
The design of the reservoir container of the print head is sophisticated, because it is initially filled with colorant and transported to the customer, and thereafter must deliver a flow of filtered colorant without leakage under a variety of conditions such as different orientations of the print head and use of the printer at different altitudes and temperatures. In one present approach, the interior of the reservoir container contains a compliant open cell foam. Colorant is filled into the foam during manufacture. The colorant is retained within the pores of the foam, and slowly flows to the ejector over the life of the print head. Filling of the reservoir container requires great care to avoid pockets of colorant that can leak, air pockets, and defects in the foam that cause irregular colorant flow.
Simply increasing the size of the reservoir container is not an acceptable solution to the problem of providing a larger colorant supply, because the container is supported upon the printer carriage and moves with the nozzle mechanism. Increasing the size of the reservoir container would necessarily increase the size, strength, and cost of the structure that supports and moves the carriage. The performance of the printer would suffer, because of the greater mass of the carriage and container.
There is a need for an approach for increasing the amount of colorant available for droplet ejection in such a print head. The approach should permit the desirable features of the present approach to providing colorant to be retained, provide more colorant, and not unduly increase the cost or complexity of the printer. The present invention fulfills this need, and further provides related advantages.
SUMMARY OF THE INVENTION
The present invention provides a printer, print head, and approach for their operation that substantially increase the colorant supply available for ejection by the print head. The well established design of the currently used colorant reservoir is largely retained in a modified form. Complex instrumentation for monitoring the colorant level in the reservoir container is not required. It is not possible to overfill the container using the approach of the invention, even though such instrumentation is not present.
With the present approach, after the reservoir container is partially depleted of colorant, it is refilled at a service station location of the printer. To accomplish the refilling, a partial vacuum is drawn within the container. The vacuum port is sealed, and the interior of the container is connected to a larger colorant supply exterior to the container, and typically mounted on the frame of the printer. Colorant is drawn into the container through a refill means by the partial vacuum, until the pressure within the container and at the colorant supply are equalized or nearly equalized. It is impossible to overfill the reservoir container with this refilling approach, because the only force drawing colorant into the container is the partial vacuum, which decreases and approaches zero as the colorant flows into the container. It is therefore not necessary to provide complex metering and measurement instrumentation that would otherwise be required to avoid overfilling. This approach also results in the proper pressurization conditions inside the container for a smooth and immediate flow of colorant into the ejector portion of the print head.
The invention therefore extends to a printer, a print head, and a method of accomplishing the filling operation. In accordance with the first aspect of the invention, an ink jet printer comprises print head means for ejecting droplets of a colorant, including a reservoir container that holds a volume of the colorant, a colorant ejector in communication with the reservoir container that receives a flow of colorant from the reservoir container and ejects droplets of colorant therefrom under command, a vacuum port in the wall of the reservoir container, and refill tube means for refilling the reservoir, the refill tube means communicating from the exterior of the reservoir container into the interior of the reservoir container; and a service station for adding colorant to the reservoir container, including a colorant supply, a vacuum manifold, valve means for controllably placing the colorant supply in communication with the refill tube means and sealing the colorant supply from the refill tube means, and for controllably placing the vacuum manifold in communication with the vacuum port and sealing the vacuum manifold from communication with the vacuum port, and support means for holding the reservoir container in contact with the valve means, for preventing ejection of colorant, and for preventing introduction of air into the print head.
The printer mechanism, apart from the print head, is also unique. In accordance with this aspect of the invention, an ink jet printer is operable with print head means for ejecting droplets of a colorant, the print head means including a reservoir container that holds a volume of the colorant, an ink ejector that receives colorant from the reservoir container and ejects droplets of colorant therefrom, and a refill tube or needle that extends from the exterior of the reservoir container into the interior of the reservoir container. The printer comprises a service station whereat colorant is added to the reservoir container, including a colorant supply, a vacuum manifold, valve means for controllably placing the colorant supply in communication with the refill tube and sealing the colorant supply from the refill tube, and for controllably placing the vacuum manifold in communication with the interior of the reservoir container and sealing the vacuum manifold from the reservoir container, and support means for holding the reservoir container in contact with the valve means, for preventing ejection of colorant, and for preventing introduction of air into the print head. The support seals the nozzles to prevent air from being drawn therein while the interior of the reservoir container has a vacuum drawn thereon.
Further in accordance with the invention, a thermal ink jet print head comprises a reservoir container having a foam mass therein and adapted for holding a supply of the colorant; an ink ejector that receives colorant from the reservoir container and ejects colorant therefrom; a vacuum port in the wall of the reservoir container; and a refill tube (alternately termed a refill needle) inserted from the exterior of the reservoir container into the foam mass within the reservoir container.
The invention also extends to the process for adding colorant to the print head of a thermal ink jet printer, comprising the steps of furnishing a colorant reservoir container; creating a partial vacuum in the interior of the reservoir container using a vacuum manifold; and sealing the interior of the reservoir container from the vacuum manifold and permitting colorant to be drawn into the interior of the reservoir container by the partial vacuum created in the step of creating.
In the preferred approach, the reservoir container contains an open-pore foam that retains the colorant and prevents leakage. The refill tube in the form of a refill needle penetrates the top of the reservoir container into the interior of the foam. The needle is vented to the air during normal operation of the printer and print head. When colorant is to be added into the reservoir container during printer operation, the print head is moved to a service station position at one end of the traverse. A support holds the container in the proper position against a valve, and seals the nozzles to permit a vacuum to be drawn on the interior of the container. The valve closes the exterior end of the needle and simultaneously connects the vacuum port at the top of the reservoir container to a vacuum manifold that draws air out of the container to create a partial vacuum. After the vacuum is drawn, the valve is again operated to close the vacuum port and connect the exterior end of the needle to the exterior colorant supply, which typically might be a vented bottle of colorant fastened to the frame of the printer and connected to the valve by a piece of tubing. The partial vacuum draws colorant from the exterior colorant supply, through the needle, and into the foam within the reservoir container. As colorant flows into the reservoir container, it refills the reservoir container and reduces the gas space, thereby increasing the pressure and reducing the degree of vacuum. Ultimately, the gas pressure within the reservoir container approaches one atmosphere, and there is no further driving force to draw colorant into the reservoir container. The flow of colorant stops before the reservoir container can be overfilled. The valve operates to open both the needle and the vacuum port, the support is withdrawn, and the print head is again ready for printing.
This approach is fast and clean, with little likelihood of spillage of colorant or overfilling of the container. The amount of colorant refilled depends upon how much colorant has been removed from the reservoir container during prior printing. If there has been little demand and little colorant removed, there will be only a small amount of air drawn out by the vacuum manifold and only a small amount of colorant refilled from the colorant supply. Conversely, if there has been a high demand for colorant, then a large amount of colorant will be refilled into the container from the colorant supply. This self-regulating feature, where no measurements of liquid level or special instrumentation are required, is particularly desirable for printers that have multiple print heads, each producing droplets of different colors.
After refilling, the state within the reservoir container returns to essentially that when the reservoir container was first used, fresh from the factory, by the customer. It will be known from the size of the reservoir and the printing characteristics of its nozzles that the reservoir container holds sufficient colorant to print at least some fixed number of lines of print, a number that ordinarily will be at least several thousand lines. The refilling operation can be programmed to be undertaken within that number of lines, and preferably when page changes of the printing medium occur. Because the refilling operation is accomplished quickly, there is little if any interruption to the primary printing function of the printer.
Other features and advantages of the invention will be apparent from the following more detailed description of the preferred embodiment, taken in conjunction with the accompanying drawings, which illustrate, by way of example, the principles of the invention.
BRIEF DESCRIPTION OF THE DRAWINGS
FIG. 1 is a perspective view of a thermal ink jet print head assembly, with a portion of the interior illustrated in phantom lines;
FIG. 2 is a side sectional view of the print head assembly of FIG. 1, taken generally along line 2--2;
FIG. 3 is a perspective view of a thermal ink jet printer;
FIG. 4 is a schematic plan view of a portion of the ink jet printer of FIG. 3, with the cover removed to illustrate internal features;
FIG. 5 is a side elevational view of the service station of FIG. 4, with the print head assembly illustrated in section;
FIG. 6 A, B and C is a three part diagrammatic view of the refilling operation using the present approach and a three-position slide valve, showing (A) the relative relationship of the print head and the service station prior to the refilling operation, (B) the relationship of the print head, the service station, and the valve when a vacuum is applied to the container, and (C) the relationship of the print head, service station, and the valve as colorant flows from the colorant supply to the reservoir container;
FIG. 7 is a perspective view of a two-position rotary valve that may be used in the refilling operation; and
FIG. 8 is a graph illustrating the colorant level during refilling of the reservoir container.
DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENT
The process of the present invention is preferably used in conjunction with a thermal ink jet printer, although it is not so restricted. A thermal ink jet printer utilizes a print head that creates and ejects microdroplets of colorant by vaporization of small bubbles of colorant. A thermal ink jet print assembly 10, used to eject droplets of colorant, such as an ink or a dye, toward a print medium in a precisely controlled manner, is illustrated in FIGS. 1 and 2. The general features of such a print assembly are discussed in more detail in U.S. Pat. No. 4,635,073, whose disclosure is incorporated by reference.
The print assembly 10 includes an ejector 12. The ejector includes a plurality of individual nozzles that eject colorant toward a printing medium. The construction and operation of the ejector 12 do not form a part of the present invention.
The ejector 12 is supported upon, and projects outwardly from, a reservoir container 14. The reservoir container 14 is a hollow rectangular structure having at the lower end and outlet 16 with a filter 18, through which colorant flows from the interior of the container 14 to the ejector 12.
The interior of the container 14 is partially filled with a generally conforming piece 20 of an open cell, reticulated foam. The foam piece 20 is preferably made of polyether polyurethane having 75 pores per inch and felted to three times original density. The foam piece 20 is made in the same general shape as the interior of the container 14, but slightly oversize. The foam piece 20 is therefore in a slight compression after it is inserted into the container 14. The compression, along with a high degree of care taken in inserting the foam piece 20 and filling it with colorant, avoids gas pockets within the container 14, after it is filled with colorant. At the factory, colorant is introduced under vacuum into the foam with a needle stuck into the interior of the foam piece 20, to fill the container 14 with colorant. Details of the factory filling operation can be found in the publication "Ink Retention in a Color thermal Inkjet Pen" by Erol Erturk, Brian D. Gragg, Mary E. Haviland, W. Wistar Rhoads, Jim L. Ruder, and Joseph E. Scheffelin, published in the Hewlett Packard Journal, Aug. 1988.
After colorant is introduced into the foam piece 20, a plug 22 is fitted to the body of the container 14, and ultrasonically welded in place. The plug has a vent therethrough, which functions as a vacuum port 24. The plug 22 also has a refill needle 26 therethrough, whose tip extends downwardly into the body of the foam piece 20. The needle 26 is preferably positioned so that its lower tip is near the bottom of the container 14, but not adjacent the filter 18 and ejector 12. The refill needle functions as a refill tube or refill tube means during refilling of the reservoir container 14, in a manner to be described.
FIG. 3 illustrates in general view one type of ink jet printer 30 with which the print head assembly 10 may be used. Further detail of the printer 30 is provided in the plan view of FIG. 4. The printer 30 includes a cylindrical roller or platen 32 upon which a sheet of a printing medium 34 is supported. The platen 32 is rotatably driven by a stepping motor or DC servo motor 36 (see FIG. 4) that causes it to controllably rotate in either direction. Rotation of the platen 32 advances the printing medium in the selected direction.
A carriage 40, depicted in more detail in FIG. 4, is supported above the printing medium 34 on bearings 42 from a rail 44. The carriage 40 slides along the rail 44 under the control of a traversing motor 46 acting through a belt or cable 48 that extends from the motor 46 to the carriage 40.
The print head assembly 10 is supported in the carriage 40, in a generally facing but spaced apart relationship to the printing medium 34, so that colorant droplets ejected from the ejector 12 strike the printing medium 34. (Multiple print heads, or at least multiple ejectors 12, are needed where a variety of colors are to be printed, and such an approach is within the scope of the present invention.)
At one extreme of carriage movement is a service station 50, whose structure and function can be understood more clearly by reference to FIG. 5. The service station 50 is positioned off the end of the printing medium 34, so that the carriage 40 and ejector 12 are not over the printing medium when they are within the service station 50. The service station 50 includes a valve 52. A colorant supply line 54 extends from the valve 52 to a colorant supply bottle 56 mounted to the frame of the printer 30. The bottle 56 contains a large volume of colorant, usually many times that of the colorant contained within the reservoir container 14. Under appropriate conditions, colorant is transferred from the bottle 56 through the line 54 and through the valve 52, into the interior of the reservoir container 14.
A vacuum line 58 extends from another portion of the valve 52 to a vacuum manifold 60, also mounted to the frame of the printer 30. The vacuum manifold 60 applies a partial vacuum through the line 58. It is not contemplated that the vacuum must be a high vacuum or even that attained with a mechanical forepump. Instead, it is preferred that the vacuum manifold be pumped to a pressure of about 1-8 psia (pounds per square inch, absolute) by an appropriate pump, such as a syringe or peristaltic pump, which are inexpensive. Most preferably, the pressure is about 1-3 psia. In the illustrated preferred embodiment, a plunger 62 is retracted within the body of a syringe 64 by a linearly acting motor 66, drawing a vacuum within the body of the syringe 64 and thence in the vacuum line 58. Alternatively, another type of structure that produces the required motion, such as a gear arrangement operating from the linear movement of the carriage 40, would be operable.
The print head assembly 10 is moved into position just below and adjacent the valve 52 of the service station 50, when refilling of the container 14 is required. A support 70 having an compliant seal 72, such as a nonabsorbing piece of urethane, is raised up against the underside of the print head assembly 10, and specifically the ejector 12, by a pair of cams 74 on cam shafts 76. The seal 72 prevents leakage of colorant from the ejector 12, and permits a vacuum to be drawn on the interior of the reservoir container 14, during refilling. Rotation of the cam shafts 76 occurs under control of a motor such as the carriage traverse motor or the paper advance motor, or a trip arrangement when the print head assembly 10 enters the service station 50.
The slight upward movement of the print head assembly 10 induced by the support 70 causes the upper surface of the print head assembly 10 to contact the valve 52. More specifically, in the position of contact, the vacuum port 24 of the container portion of the print head assembly 10 is within the periphery of an annular rubber seal 78 affixed to the underside of the valve 52, that seals against vacuum leakage. This permits a vacuum to be drawn on the interior of the reservoir container 14 through the port 24. The seal need not be extraordinarily tight as might be required for high vacuum systems, but must be sufficient to permit a vacuum to be drawn during the refilling operation.
The upper end of the refill needle 26 is flared outwardly to form a colorant flow port 80, which communicatingly contacts the underside of the valve 52, so that colorant may flow from the colorant supply bottle 56 through the line 54 and the valve 52, and thence into the interior of the reservoir container 14. After completion of the filling operation, the camshafts 76 are rotated to lower the print head assembly 10 out of contact with the valve 52, and the print head assembly 10 can be moved back to the printing position over the printing medium.
The mode of operation of the service station 50 is illustrated in FIG. 6. The valve 52 can be of any acceptable form, such as a rotary valve, a slide valve, or otherwise. In the embodiment illustrated in FIG. 6, the valve is a three-position slide valve having elements that can be operated as required to accomplish the refilling operation. An acceptable valve of this type can be molded from plastic or purchased from a commercial supply house such as Cole-Parmer. (A two position rotary valve is illustrated in FIG. 7, and will be discussed subsequently.)
Referring to FIG. 6A, the relationship of the print head assembly 10 and the valve 52 is shown before and after the refilling operation. The print head assembly 10 does not contact any part of the valve 52. From left to right in the view of FIG. 6A, the valve mechanism includes a downward flow path 90, a closed element 92 where nothing flows, a second closed element 94 where nothing flows, an upward flow path 96, and a third closed element 98. In the view of FIG. 6A, the internal connections within the valve 52 to the colorant supply line 54 and the vacuum supply line 58 are such that these lines are closed by the second closed element 94 and the third closed element 98, respectively.
After the cam system is operated to force the seal 72 upwardly so that the print head assembly 10 contacts the valve 52 in the manner previously discussed, the valve 52 is operated as illustrated in FIG. 6B so that the colorant supply line 54 is closed by the first closed element 92, but the vacuum line 58 is connected to the interior of the reservoir container 14 through the upward flow path 96. That is, a vacuum is drawn on the interior of the reservoir container 14 along the communicating passage from the vacuum manifold 60 through the line 58, the upward flow path 96, and the vacuum port 24 (sealed against gas loss by the seal 78). No colorant flows into the container because the line 54 is sealed.
Once a partial vacuum is drawn on the interior of the reservoir container 14, the valve 52 is again operated, to the position indicated in FIG. 6C. The vacuum line 58 and the port 24 are sealed by the second closed element 94. The colorant supply line 54 is connected to the refill needle 26 through the downward flow path 90. Colorant is drawn into the interior of the container 14 by the differential pressure of the vacuum previously created in the interior of the container 14. The colorant flows from the colorant supply 56, which is vented to atmospheric pressure, through the colorant supply line 54, the downward flow path 90, the needle 26, and into the body of the foam 20 within the reservoir container 14, gradually saturating the foam with colorant.
An alternative two-position rotary valve 100 is shown in FIG. 7. This valve 100 is preferably used where a vacuum is not constantly maintained, but is created only when required. The vacuum manifold 60 therefore need not be sealed between refilling cycles, as was described for the slide valve approach in FIG. 6(C). The valve 100 includes a hollow cylindrical valve body 102 with an upper sealing surface 104 and a lower sealing surface 106. Bores 108 and 110 are formed through the valve body 102 in the proper locations to connect the colorant supply line 54 to the colorant flow port 80, and the vacuum line 58 to the vacuum port 24, respectively. A rotatable valve core 112 extends through the valve body 102. The core 112 has two flow path passages diametrically therethrough, a first passage 114 adjacent the bore 110, and a second passage 116 adjacent the bore 108. The passages are circumferentially displaced from each other. In a first rotational position, the passage 114 connects the vacuum line 58 to the vacuum port 24, through the bore 110. In a second rotational position, the passage 116 is aligned to connect the colorant supply line 54 to the colorant flow port 80 through the bore 108. These two rotational positions are sufficient to provide the colorant and vacuum connections, when required. The valve may be operated to a third rotational position of the core 112, where there is no communicating connection between the colorant supply line 54 and the colorant flow port 80, or between the vacuum line 58 and the vacuum port 24. Both the colorant flow and vacuum are therefore closed off. The valve 100 can therefore be operated to achieve the same results as a three position valve, except by rotational rather than sliding movement.
When the reservoir container 14 is filled at the factory with colorant, prior to shipment to the customer, the precise amount of colorant to supply is known, and can be provided exactly. If, however, the reservoir container is to be refilled in the field, after operation, it is not known exactly how much colorant has been ejected, and care must be taken to ensure that too much colorant is not added so that the reservoir container would overfill and leak. The present approach is self-regulating, because it is not possible to overfill the reservoir container 14. As the colorant is permitted to flow into the reservoir container in the portion of the refilling process discussed in conjunction with FIG. 6C, the vacuum level falls (or alternatively, the pressure, which is below atmospheric, rises toward atmospheric pressure). Since the colorant supply bottle is vented to atmospheric pressure, the driving force for colorant flow is the pressure difference between one atmosphere and the current pressure within the container. When that pressure reaches approximately one atmosphere, which it must prior to complete refilling of the reservoir container 14, the flow of colorant ceases because the driving force disappears. In practice, the colorant flow ceases prior to the point where the pressures balance, because of fluid friction in the line, differences in elevation, or intentional closing of the valve before the flow has stopped. In any event, overfilling is impossible.
The reservoir container 14 will not fill completely with this refilling approach, but the refilling operation may be repeated sufficiently often that there is no chance that the reservoir container 14 will run dry. The present approach is self-regulating also in the sense that, where multiple print heads are used, as in the case of color printers, each print head can be individually refilled automatically from its own individual colorant supply, but using the same vacuum level, so that the level of colorant in the multiple print heads tends to remain roughly equal over time even where the print heads consistently eject different amounts of colorant.
FIG. 8 graphically illustrates the refilling of the reservoir container 14. FIG. 8 presents the results of a computer simulation of reservoir container refilling for particular reservoir container size and vacuum conditions, but with differing initial colorant levels in the reservoir container at the beginning of refilling. In this simulation, the volume of the pen was 22 cc (cubic centimeters), and the vacuum drawn on the interior of the container was 2.0 psia. For curve A, the container had only about 5.5 cc of colorant before refilling commenced (time equals 0), but reached a volume of 19 cc after 12 seconds. For curve F, the container had about 17.5 cc of colorant before refilling commenced, but reached a volume of 21 cc after 2 seconds. Intermediate curves B-E illustrate intermediate initial volumes of colorant prior to refilling. Although the vacuum-driven refilling varied as to the time required to reach the maximum refill level in each case, in all cases the final volume of colorant after refilling was 20 +/- 1 cc. It is not possible for the container to be overfilled. In normal practice, the level of colorant in the container would not be permitted to fall to the 5 cc level. Instead, the printer would be programmed to initiate refilling after normal usage reduced the colorant level to about 10 cc. The rate of refilling and the volume after refilling is dependent upon the vacuum level attained during the refilling operation. In color ink jet systems where there are multiple pens and reservoir containers, the levelling effect illustrated in FIG. 8, wherein the final colorant volume is approximately the same regardless of the volume of colorant in a reservoir prior to refilling, tends to equalize the amount of colorant in each of the reservoir containers, even where there has been unequal usage of colorant prior to refilling.
The present invention provides an inexpensive but reliable approach to refilling ink jet print heads during service. The refilling is accomplished automatically, without the need for operator attention and also without the need for a complex control system. Although a particular embodiment of the invention has been described in detail for purposes of illustration, various modifications may be made without departing from the spirit and scope of the invention. Accordingly, the invention is not to be limited except as by the appended claims. | An ink jet printer (30) includes a print head reservoir container (14) having a colorant refill needle (26) extending from the exterior to the interior thereof and a vacuum port (24) therein, and a service station (50) having a valve (52) that controllably connects the refill needle (26) to a colorant supply (56) and controllably connects the vacuum port (24) to a vacuum manifold (60). Colorant is added to the reservoir container (14) by first drawing a vacuum on the interior of the reservoir container (14) with the vacuum manifold (60) connected to the vacuum port (24) and with the refill needle (26) sealed, and then sealing the vacuum port (24), placing the refill needle (26) in communication with the exterior colorant supply (56), and permitting the partial vacuum in the interior of the reservoir container (14) to draw colorant from the colorant supply (56) into the interior of the reservoir container (14). | 1 |
BACKGROUND OF THE INVENTION
1. Field of the Invention
This invention relates to a mechanism for attaching a brake disc to a wheel.
2. Discussion of the Problem
In a disc brake mechanism, a cylindrical metallic disc, which has a pair of smooth, flat, parallel surfaces, is rigidly attached to a wheel. A caliper assembly, which has a pair of disc brake pads, is rigidly mounted on a vehicle frame surrounding a section of the disc such that each pad is adjacent one of the surfaces on the disc. To stop the vehicle, the caliper assembly is actuated, for example by high pressure hydraulic fluid, to clamp the brake pads against the disc surfaces and thereby brake the wheel.
When the brake pads are clamped against the disc a great deal of heat is generated. This heat causes radial thermal expansion of the disc, which moves relative to the wheel, which experiences little temperature change. Since the disc expands and contracts during each braking cycle, the disc mounting mechanism must accommodate this relative movement between the disc and wheel without loosening and without causing undue stress and wear of the elements. Consequently, a direct axial attachment of the disc to the wheel by bolts is not adequate, since disc thermal expansion will exert cyclical bending forces on the bolts and ultimately cause failure through fatigue.
In one of applicants' early designs, elongated holes were provided in the disc to accommodate the cyclical thermal radial expansion and contraction. Each bolt contained a stack of belleville washers adjacent the bolt head and a hardened washer engaging the disc. The belleville washers were provided to maintain adequate bolt torque on the disc despite wear caused by movement of the disc relative to the hardened washer. Upon testing, it was found that the disc did not slide on the hardened washers, but rather the frictional forces between the washer and disc, due to the forces of bolt torque, as maintained by the belleville washers, caused the head of the bolt to move with the disc. Thus, the bolt was bending. It was learned that the cyclical bending was fatiguing the bolts and reducing bolt life to a point significantly below the design life of the disc. The tests also showed that after a number of braking cycles the bolt moved very slightly in and out of the threaded bore in the wheel. This indicated that the threads were wearing. Consequently, this design was unacceptable.
3. Description of the Prior Art
One known method of attaching a disc to a wheel is to provide flexible arms which attach at one end to the disc and at the other end to the wheel. The problem with this design is that it is complex, costly and bulky.
Another known design for attaching a disc to a wheel uses a two-part disc. The disc provides an outer braking ring and an inner fastening ring which is rigidly attached to the wheel. The outer braking ring and the fastening ring are connected by spring loaded, radial pins. In this way, the outer braking ring is isolated from the fastening ring. A problem with such design is that it is quite expensive.
Applicants have devised a mechanism to secure a brake disc to a wheel which accommodates cyclical disc thermal expansion without fatiguing the mounting bolts which is simple and inexpensive.
SUMMARY OF THE INVENTION
Applicants' mechanism for mounting a disc on a wheel utilizes a plurality of equally spaced bolts. The bolts pass through elongated holes near the hub of the disc and engage threaded bores in the wheel. Each bolt has an assembly which contains a stack of belleville washers, a hardened washer and a spring clip retainer to maintain a predetermined bolt torque to clamp the disc to the wheel.
Additionally, the mechanism includes a thin, flat, metal mounting ring which is interposed between the bolt washers and outer surface of the disc and is piloted on the wheel's axle. Each bolt assembly engages the mounting ring which is radially fixed and thus isolates the bolt assemblies from movement of the disc. Since the disc can move relative to the wheel without causing corresponding movement of the hardened and belleville washers, the washers do not apply a bending stress to the bolts.
DESCRIPTION OF THE DRAWINGS
FIG. 1 is a front view of a disc mounted on a wheel according to the instant invention;
FIG. 2 is a sectional view taken along line 2--2 of FIG. 1;
FIG. 3 is an enlarged detail of the encircled portion of FIG. 2;
FIG. 4 is a front view of the mounting ring of the instant invention;
FIG. 5 is a side view, partially in section, of the mounting ring of FIG. 4; and
FIG. 6 is an exploded view of a disc mounting assembly.
DESCRIPTION OF THE PREFERRED EMBODIMENT
Referring to FIGS. 1 and 2, a metal wheel 10, such as is used on a rail transit vehicle, is shown pressfitted onto the outer surface 11 of an axle 12. The axle 12 projects beyond the flat outermost surface 13 of the hub of the wheel 10 and terminates with an end surface 14. A cast metallic brake disc 15 having a pair of machined, parallel, flat surfaces 16, 17, which are joined by a plurality of ribs 18, is attached to the wheel 10. The disc 15 is part of a disc brake system which includes a caliper assembly, not shown. The caliper assembly carries a pair of disc brake pads 19, 20 adjacent the disc surfaces 16, 17, respectively. When the caliper assembly is actuated, the disc brake pads 19, 20 are moved to engage the disc surfaces 16, 17 to clamp the disc 15 therebetween and thereby brake the wheel 10.
When the brake pads 19, 20 are clamped against the disc surfaces 16, 17 for braking, the resulting friction generates heat which greatly increases the temperature of the disc 15. The disc 15 may reach a temperature of 800° F. As the temperature of the disc 15 increases, the disc expands radially. After braking, the disc cools and contracts. Consequently, the disc 15 must be attached to the wheel 10 in a manner which will accommodate the thermal expansion and contraction of the disc 15.
A plurality of bolt assemblies 21, each of which includes a bolt 22 with a stack of belleville washers 23 and a hardened flat washer 24 all of which are retained by a spring clip 25, which is recessed in the hardened washer 24, are part of the mechanism which fastens the disc 15 to the wheel 10. Each bolt 22 passes through one of a plurality of equally spaced holes 26 in the hub 27 of the disc 15 into mating threaded bores 28 in the hub 29 of the wheel 10 to clamp the flat surface 17 of the disc 15 against the flat surface 13 on the wheel 10. In order to accommodate the expansion and contraction of the disc 15, the holes 26 in the hub 27 are radially elongated so that the disc 15 may move radially relative to the wheel 10 and bolt assemblies 21. If the holes 26 were not elongated and the bolts 22 fit tightly therein, the disc 15 would exert an unacceptably high stress on the bolts 22 when it underwent thermal expansion during braking, which could shear the bolts. Likewise, the fixed bolts 22 could overstress the disc 15 in the area of the bolt holes 26 and crack it. Since the holes 26 are elongated only in the radial direction, the disc 15 cannot rotate relative to the wheel 10 and the bolt assemblies 21.
An important part of the disc fastening mechanism, shown in FIGS. 2-6, is a mounting ring 30 which is interposed between a disc surface 32 and hardened washer 24. Ring 30 has a plurality of holes 31, which are aligned with respective holes 26 and bores 28, in the brake disc 15 and the wheel 10 respectively, and is clamped against the outer surface 32 of the disc 15 by the bolt assemblies 21.
The mounting ring 30 has a cylindrical inner flange 34 which engages the outer surface 11 of the axle 12 and pilots the ring 30 thereon. The piloting of ring 30 on the axle 12 prevents radial movement of the mounting ring 30. Consequently, when the disc 15 moves radially, the disc surface 32 slides on the inner face 35 of the ring 30, which remains stationary. Therefore, the disc 15 can move radially without transmitting this movement to the bolt assemblies 21 and does not cause bending of the bolts 22. If the bolt assemblies 21 were used to secure the disc 15 against the wheel 10 without the mounting ring 30, or if the ring 30 could move with the disc 15, movement of the disc hub 27 would cause corresponding movement of the bolt assemblies 21 and consequent bending of the bolts 22. This bending would cause premature failure of the bolts 22 due to fatigue.
Radial movement of the disc 15 causes wear between the surface 17 of the disc hub 27 and the surface 13 on the wheel 10 and between the outer surface 32 on the disc hub 27 and the inner face 35 on the mounting ring 30. The belleville washers 23 maintain tension on the bolts 22 to prevent loosening of the bolts 22 caused by this wear.
Although a preferred embodiment of the invention has been illustrated and described, it will be obvious to those skilled in the art that various changes may be made in the details and arrangements of the parts without departing from the spirit and scope of the invention as it is defined in the claims hereto appended. | A mechanism for mounting a brake disc on a rotatable member using a plurality of mounting bolts, which mechanism includes a mounting ring secured against radial movement and interposed between the bolts and the disc which permits radial expansion of the disc without transmitting the disc movement to the mounting bolts. | 5 |
BACKGROUND OF THE INVENTION
1. Field of the Invention
The present invention relates to an SNMP (Simple Network Management Protocol), and more particularly, to a method for controlling trap generation of an SNMP.
2. Description of the Background Art
One of network management protocols for a communication network management, the SNMP defines a control structure for a management-object resource (an object) on the basis of an RFC 1157 standard.
FIG. 1 shows a construction of a manager and an agent adopting an SNMP in accordance with a conventional art.
As shown in FIG. 1 , the SNMP is adopted in the communication network consisting of a central SNMP management system (manager) 10 and at least one SNMP management-object system (agent) 12 .
The manager 10 serves to control a management-object resource (object) of the agent 12 through the SNMP. That is, the manager 10 outputs an object access message (GET/SET/GETNEXT) to the agent 12 and performs searching, changing, generating or deleting on the object defined in an MIB (Managed Information Base) of the agent 12 .
The GET message is a message to read a data from the MIB 14 , and the SET message is a message to write a data in the MIB 14 . The GETNEXT message is a message to read an object next to the object read by the GET message. A GETResponse is a message to transmit the data read from the MIB 14 to the manager 10 according to the GET/GETNEXT message.
Accordingly, when the manager 10 searches information, it transmits an OID (Object ID) together with the object access message (GET/GETNEXT) to the agent 12 , and the agent 12 transmits the GETResponse message including a value of the corresponding data together with the OID back to the manager 10 . In this respect, the OID is the ID of the object, and every data is discriminated by the OID.
The SNMP supports a ‘Trap’ operation so that the agent 12 voluntarily transmits information on the object to the manager 10 , without depending on the request of the manager 10 .
Describing a management object behavior, access authorization and grammar structure allowable for the object existing in the MIB 14 , the SNMP defines a trap in the MIB 14 by relating an object to be subjected to trap generation to a condition of the trap generation. The trap is defined as follows:
ObjectName TRAP-TYPE ENTERPRISE {enterprise name} VARIABLES {variable name} DESCRIPTION “comment” ::=Sub OID
Accordingly, when the state (i.e., system up/down and system disturbance) of the object is changed, the agent 12 voluntarily outputs a TRAP PDU (Protocol Data Unit) to inform the manager 10 of the state change of the object. In this respect, the TRAP PDU includes an OID and a corresponding data value.
The network management protocol through the SNMP will now be described in detail.
The manager 10 outputs an ID of the object (OID) together with the GET message to the agent 12 in order to search the state of the object of the agent 12 . At this time, the OID is an ID of each object, by which every management-objected data is discriminated.
Upon receipt of the GET request, the agent 12 reads a data value from the MIB 14 and transmits the GETResponse message to the manager 10 . The GETResponse message includes a pair of an OID and a read data (OID and a read data) form.
The manager 10 outputs the next OID together with the GETNEXT message in order to search the next object, and in response, the manager 12 transmits the GETResponse message in the same form to the MANAGER 10 . This operation is repeatedly performed so as for the manager 10 to search the state of the every object.
When the manager 10 writes a data in the MIB 14 , it outputs an OID of the object and a SET message, and the agent searches a target data by using the OID and changes a corresponding data value.
Meanwhile, unlike the GET/GETNEXT/SET message, the trap management behavior is used for the agent 12 voluntarily report the state of the object periodically. That is, after the agent 12 relates a specific data and a trap generation condition, when it comes to a predetermined cycle, the agent 12 outputs a trap PDU Protocol Data Unit) to inform the manger 10 of the change in the state of the object. Also, the TRAP PDU consists of a pair of an OID and a data, the same as that of the GETResponse message.
However, in the SNMP standard-based MIB technique of the conventional art, the object to be subjected to the trap generation is statically defined. Accordingly, conventionally, since the trap operation is adoptable only to the object defined in the MIB, the manager is not able to add or delete a specific object as an object as necessary during the network management operation.
In addition, once a trap condition is defined in the MIB, a trap operation is applied to every defined object, resulting in that the agent generates a TRAP PDU even for a object with little state change.
Thus, the agent generates a trap more than necessary and thus the manager should process numerous TRAP PDU transmitted from the plurality of agents, so that the traffic is increased. This works as a factor to degrade the management efficiency in the management network using the SNMP
SUMMARY OF THE INVENTION
Therefore, an object of the present invention is to provide a method for controlling trap generation which is capable of effectively controlling trap generation by defining a trap behavior individually for an object of an SNMP MIB.
To achieve these and other advantages and in accordance with the purpose of the present invention, as embodied and broadly described herein, there is provided a method for controlling trap generation of an SNMIP operated between a manager and at least one agent, wherein a TrapFlag field and a TrapPeer field are defined for each management-object resource (each object) in describing a MIB of an SNMP and two or more objects are correlated to define a trap generation condition.
To achieve the above object, there is provided a method for controlling trap generation of an SNMP which is operated between a manager and at least one agent, including the steps of: defining a TrapFlag field and a TrapPeer field in an MIB of an agent; setting a TrapFlag field value according to the message outputted from the manager; setting a TrapPeer field value for each object by the agent according to the Trap generation condition defined in the MIB; and generating a trap for an object according to the values of the TrapFlag field and the TrapPeer field.
To achieve the above object, there is provided a method for controlling trap generation of an SNMP including the steps of: defining a TrapFlag field and a TrapPeer field in an MIB of an agent; and generating a trap for an object according to the values of the TrapFlag field and the TrapPeer field as defined.
In the method for controlling trap generation of an SNMP, the step of generating a trap includes the sub-steps of: searching the TrapFlag field of each object when it comes to a trap generation period; checking a state of the TrapPeer field in case that the TrapFlag is in an ‘ON’ state; and generating a trap for a corresponding object in case that the TrapPeer is in an ‘ON’ state.
The foregoing and other objects, features, aspects and advantages of the present invention will become more apparent from the following detailed description of the present invention when taken in conjunction with the accompanying drawings.
BRIEF DESCRIPTION OF THE DRAWINGS
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. 1 shows a construction of a manager and an agent adopting an SNMP in accordance with a conventional art;
FIG. 2 shows a construction of a manager and an agent adopting an SNMP in accordance with the present invention; and
FIG. 3 is a flow chart of a method for controlling trap generation of the SNMP performed in the agent of FIG. 2 in accordance with the present invention.
FIG. 4 is a detail flow chart of a method for generating a trap in the trap generating step S 4 of FIG. 3 in accordance with the present invention.
DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS
Reference will now be made in detail to the preferred embodiments of the present invention, examples of which are illustrated in the accompanying drawings.
In the present invention, when a trap object is described in an MIB of the SNMP, trap-related information is additionally defined for each object. The trap-related information is defined by adding the following fields in an MIB technique document.
1. TrapFlag Field
A TrapFlag field is a field representing whether a trap is to be generated or not for an object described in the MIB. The TrapFlag field is set to be turned on or off by the manager.
In case that the TrapFlag field is in an ON state, the agent generates a TRAP PDU for the corresponding object, while, in case that the TrapFlag field is in an OFF state, the agent does not generate a TRAP PDU for the corresponding object.
Accordingly, when an object of which state is little changed during a network management operation is generated, the TrapFlag field of the corresponding object is set to be “OFF” so that, even though a specific object is not deleted from the management target, the same effect can be obtained.
2. TrapPeer Field
A TrapPeer field is a field defining a trap generation condition for an object, which is set by ‘ON’ state (logic ‘1’) or ‘OFF’ state (logic ‘0’) by the agent. That is, in case that the state of an object satisfies a trap generation condition, the agent sets a TrapPeer field as the ‘ON’ state.
In this respect, the trap generation condition can be defined by correlating two or more objects. For example, when an object ‘B’ is greater than ‘n’ and an object ‘C’ is greater than ‘m’, a TrapPeer field is defined to be set as the ‘ON’ state. Consequently, without adding an object, the same effect can be obtained.
Accordingly, when the TrapFlag field and the TrapPeer field are all in the ‘ON’ state, the agent generates a TRAP PDU for the corresponding object.
As shown in FIG. 3 , the manager 20 defines a trap as shown below by correlating objects, trap generation conditions, a TrapFlag field, and a TrapPeer field (S 1 ).
ObjectName TRAP-TYPE ENTERPRISE {enterprise name} VARIABLES {variable name} DESCRIPTION “comment” TRAPFLAG {flag value} TRAPPEER {flag value} ::=Sub OID
For example, objects ‘A’ and ‘B’ are set and a trap generation condition can be defined as follows.
1) A value of the object ‘A’ is in the range of 1˜5 2) If the value of the object ‘A’ is greater than ‘3’, a TRAP PDU is basically generated. 3) If the value of the object ‘B’ is greater than 4, a value of the TrapPeer field of the object ‘A’ is set to be ‘ON’.
And, the manager 20 outputs a TrapFlag setting signal to the agent 22 during network management to set a TrapFlag field value (S 2 ). That is, the manager 20 sets a TrapFlag field of an object which shows little state change ordinarily as ‘OFF’ so as to count it out from an object list.
At this time, the process of the transmission of the object access message (GET/SET/GETNEXT) from the manager 20 to the agent 12 and the transmission of the GETresponse from the agent to the manager 20 is the same as in the conventional art, descriptions of which are thus omitted.
The agent 22 sets a value of the TrapPeer field of each object according to a trap generation condition as defined during network operation (S 3 ).
Thereafter, when the report period comes, first, the agent 22 generates a trap for each object according to the values of the TrapFlag field and the TrapPeer field (S 4 ). That is, as shown in FIG. 4 , first, the agent 22 searches the TrapFlag field of the object ‘A’ to check whether a corresponding TrapFlag is in an ‘ON’ state (ST 11 ).
If the TrapFlag of the corresponding object ‘A’ is in an ‘OFF’ state, even though the trap generation condition 2) is satisfied, the agent does not generate a trap. Meanwhile, in case that the TrapFlag is in an ‘ON’ state, it is checked whether the TrapPeer is in an ‘ON’ state (ST 12 ). Upon checking, in case that the TrapPeer is in an ‘ON’ state, the agent 22 generates a trap for the object ‘A’ and performs a normal operation (ST 13 and (ST 14 ).
In this manner, a trap is generated by conditions for two or more objects by using two fields. And, though a single agent is taken as an example for an explanation's sake in the present invention, a plurality of agents can be connected to the manager.
As so far described, according to the a method for controlling trap generation of an SNMP of the present invention, a TrapFlag field and a TrapPeer field are separately defined for each object in the MIB, and two or more objects are correlated to define trap generation conditions.
Accordingly, there is an effect that an object can be added or deleted as necessary, and especially, trap generation can be arbitrarily controlled.
In addition, the periodical management behavior does not performed for the object of which state is not changed, so that a traffic of the management behavior can be reduced.
Moreover, the agent is controlled and the state change is monitored by using the SNMP having the trap ON/OFF fields by objects, so that management efficiency in the management network can be increased.
As the present invention may be embodied in several forms without departing from the spirit or essential characteristics thereof, it should also be understood that the above-described embodiments are not limited by any of the details of the foregoing description, unless otherwise specified, but rather should be construed broadly within its spirit and scope as defined in the appended claims, and therefore all changes and modifications that fall within the meets and bounds of the claims, or equivalence of such meets and bounds are therefore intended to be embraced by the appended claims. | A method for controlling trap generation of an SNMP which is operated between a manager and at least one agent, wherein a TrapFlag field and a Trap Peer field are defined for each management-object resource (each object) in describing an MIB of an SNMP and two or more objects are correlated to define a trap generation condition, so that trap generation can be effectively controlled by defining a trap behavior individually for an object of an SNMP MIB. | 7 |
FIELD OF THE INVENTION
The present invention relates to an apparatus and method for biological purification of wastes. More particularly, the invention relates to an apparatus and method for the treatment of wastes, such as grease and other contaminants contained in waste water streams, ground water, soil, etc. by introducing preconditioned living organisms to the environment to be treated in order to biodegrade the waste.
BACKGROUND OF THE INVENTION
Wastes, under normal conditions, are gradually broken down or biodegraded by indigenous microorganisms, in the environment. However, biodegradation reactions are often hindered by environmental fluctuations such as changes in temperature, pH, salinity, water and air supply, etc. For example, wastes such as fat and grease are biodegraded by microorganisms to fatty acids and glycerol. In the presence of oxygen the fatty acids are further metabolized with the end product being carbon dioxide and inert byproducts. Glycerol is also metabolized as an efficient energy source.
Waste water systems, for example those in the food service industry, typically incorporate a grease trap to capture grease and other contaminants from the passing flow of waste water and to store such contaminants for eventual removal from the trap. Typically, the grease trap is accessed periodically and the contaminants removed for eventual disposal. Grease and other contaminants often build up very quickly in such traps. If they are not removed in a timely fashion, the ability of the trap to operate efficiently, or at all, is seriously affected. When a trap is no longer functional, the contaminants will bypass the trap and flow into areas which are intended to be free from these contaminants. Specifically, the contaminants will either clog up the waste water system or will flow into the municipal sewer system in violation of local ordinances or state laws. Most grease traps require relatively large compartments, particularly if the associated food service facility operates on a large volume.
A variety of approaches have been developed to increase the required period between subsequent cleanings of a grease trap by increasing the bio-degradation by microorganisms of grease in the trap. One approach to enhancing bio-degradation of grease in a grease trap is to introduce chemicals or nutrients to the trap to aid naturally occurring bacteria or microorganisms in the trap. For example, U.S. Pat. No. 5,340,376 granted to Cunningham discloses a controlled-release nutrient source that adds nutrients at low levels to a biodegradation environment to enhance microorganisms growth and activity and promote the effectiveness of the biodegradation in removing environmental contaminants. The nutrients are in the form of coated solid particles, each having a core of water soluble microorganisms nutrients encapsulated in a release rate-controlling coating. The effectiveness of biodegradation of wastes by enhancing the growth of naturally occurring bacteria or microorganisms with the introduction of a controlled-release nutrient source is still hindered due to environmental fluctuations such as changes in temperature, pH, salinity, water and air supply, etc.
Another approach to enhancing bio-degradation of grease in a grease trap is to introduce a structure upon which indigenous microorganisms can bind and grow, and thus effectively remain in the grease trap. For example, U.S. Pat. Nos. 4,925,564 and 4,670,149 both granted to Francis disclose a bacterial incubator device having an enclosure with a foraminous wall structure packed with high surface area elements such as spherical packing of a shape or size to multiply the solid bacterial growth surface area in a grease trap. The incubator is positioned at the interface of floating grease and water. Similarly, the effectiveness of biodegradation of wastes by enhancing the growth of naturally occurring bacteria or microorganisms with the introduction of a support structure is often hindered due to environmental fluctuations such as changes in temperature, pH, salinity, water and air supply, etc.
Still another approach to enhancing biodegradation of grease in a grease trap is to introduce additional microorganisms into the grease trap. For example, U.S. Pat. No. 5,271,829 granted to Heppenstall discloses a treatment system for waste water which includes a dispenser for introducing treatment material, a solution of bacteria, into a grease trap for the purpose of digesting the grease which is separated from waste water as it flows through the grease trap. The dispenser includes a housing having a compartment for holding a quantity of grease digesting material and a dispensing opening at the lower end of the compartment. A restricter is located at the dispensing opening permitting the digesting material to pass at a constant restrictive rate from the dispensing opening to the grease to be treated in a chamber of the grease trap. The grease digesting material in the dispenser will naturally go through a four phase growth cycle (i.e., lag, exponential, stationary, and death, further described in detail in a Bacterial Growth Section below) which limits its effectiveness of enhancing the biodegradation of grease on an extended or continuous basis.
Another example of introducing additional microorganisms in to a grease trap is U.S. Pat. No. 5,225,083 granted to Pappas, et al. Pappas, et al. discloses a simple method that includes adding endemic bacterial microorganisms to one or more of the drain lines for ultimate introduction into the grease trap and biodegrading grease. Depending on the bacterial microorganisms' growth cycle phases, the effectiveness of the biodegradation of grease by the microorganisms will vary.
Another approach to enhancing biodegradation of grease in a grease trap is to introduce enzymes into the grease trap to solubilize the grease. For example U.S. Pat. No. 4,940,539 granted to Weber discloses a grease trap comprising a housing having an inlet to receive waste water containing grease and an outlet. The waste water within the housing is heated by an electric heating element which is immersed in the waste water and the heating element is controlled by a thermostat to maintain a desired temperature of the water within a given range. An aqueous composition containing a mixture of enzymes and bacterial spores is introduced into the housing into contact with the waste water. The enzymes solubilize the grease while the bacteria spores biodegrade the grease. However, the ability of the bacteria to biodegrade waste will be delayed in that the bacterial spores first enter a lag phase requiring a period of time before entering an exponential growth phase in which to begin bio-degradation of the waste.
Another example, U.S. Pat. No. 4,882,059 granted to Wong, et al. discloses a method for solubilizing particulate materials in waste water which comprises the steps of cultivating aerobic bacteria in the presence of oxygen in an activator solution containing a food source until the level of the food source drops below a predetermined level causing the bacteria to begin producing increased amounts of enzymes and thereafter contacting the activated bacteria and enzymes with the particulate materials under conditions which solubilize the waste. Another example, shown in U.S. Pat. No. 5,171,687 granted to Moller, et al., discloses an apparatus for culturing and delivering microbes for waste treatment in a flow system. The apparatus includes a container having a first and second chambers. The first chamber is maintained in a nutrient rich environment for the source microbial matter supported therein while the second chamber is nutrient deficient. Water is introduced into the first chamber at a predetermined rate and flows through an outlet into the second chamber. The outlet of the second chamber is directed to a flow system benefiting from the activity of the microbial matter. In both Wong and Moller, et al., it is believed that starving the bacteria of nutrients activates enzyme production therein to aid in solubilizing particulate materials in waste water. Although the enzymes aid in solubilizing the grease, the bacteria will be ineffective in biodegrading the solubilized grease in that the bacteria being nutrient deficient will enter a stationary phase (if not death phase) necessitating that the bacteria enters a lag phase, requiring a period of time before the bacteria enters an exponential growth phase in which to begin to biodegrade the grease. In addition, enzyme hydrolysis by itself is believed to merely cause intact fatty acids to be produced which are likely to redeposit further down the sewer lines causing even greater commercial environmental damage.
Another example, U.S. Pat. No. 5,840,182 granted to Lucido et al. discloses an apparatus for incubating microorganisms and delivering microorganisms to an environment containing waste for bio-augmenting the biodegradation of waste. This apparatus comprises three separate containers each containing a specific content. The three containers are arranged in a specific orientation and this arrangement mandates a directed flow of fluid.
The first container has a bioreactor chamber containing a bacterial culture. The second container has a chamber containing an aqueous solution of inorganic nutrients and a third container has a chamber containing an aqueous solution of organic nutrients. The third container being operably linked in a one-way fluid communication between the first container and the second container. The apparatus also contains a controller having a means for introducing a supply of the inorganic solution from the second container to the organic solution of the third container and a means for removing a portion of the bacterial culture from the first container and delivering it to the environment to be treated.
As stated above, the specific three container arrangement requires that the flow of aqueous inorganic solution in the second container be supplied to the organic nutrient containing third container. Once the inorganic solution of the second container mixes with the organic nutrients in the third container, a portion of the solution is supplied to the first container. The amount of inorganic nutrients provided to the third container from the second container is controlled by a pump in the controller. However, the amount of organic nutrients that dissolves in the aqueous inorganic solution supplied to the third container from the second container and then supplied to the first container, is not metered. Since the amount of organic nutrients that dissolves in the inorganic solution is affected by physical properties such as temperature, pressure concentration etc., the amount of organic nutrients provided to the bioreactor will fluctuate as these physical properties fluctuate. This makes stabilizing fluid conditions in the bioreactor, so as to maintain the microorganisms in exponential growth, almost impossible. As a result, the microorganisms dosed to the environment to be treated by the controller are not always in the exponential phase of growth. Thus, the ability of the microorganism to biodegrade waste will diminish, causing system failures which may result in clogging and increased maintenance of the apparatus.
If the environment of the bioreactor changes and causes the microorganisms to exit the exponential phase of growth, in order to return the microorganisms back to the exponential growth phase (so as to be most productive in bio-degrading waste) restabilization of the bioreactor environment is required. In other words, stabilization of the aqueous environment in the bioreactor, including the amount of organic and inorganic nutrients, is required.
Assuming conditions can be stabilized, the microorganisms will still have to pass through a lag phase in order to return back to the exponential growth phase. If the amount of fluid, nutrients and/or the physical properties such as temperature, pH, salinity, etc., fluctuate during this period it will disrupt the re-stabilization process of the bioreactor and even further delay the return of the microorganisms to exponential growth. Any microorganisms dosed to the waste environment during this period will not be in the exponential growth phase and therefore will not actively bio-degrade waste.
Moreover, assuming that the microorganisms in the bioreactor return to the exponential growth phase, once the concentration of inorganic and organic nutrients fluctuate in the bioreactor, the microorganisms will again exit the exponential growth phase and the cycle will begin all over again. As a result, the waste in the environment being treated will not be bio-degraded and backups and clogs are likely to occur. As a result, waste may spill over into areas not intended for waste, and/or even cause waste to spill into the public sewage system in violation of local, state and/or federal laws.
There is a need for a waste bio-augmentation system for treatment of contaminants and waste products that is able to maintain the environment of the bioreactor, including the amount of fluid, organic nutrients, inorganic nutrients and other physical properties, so as to keep the microorganisms of the bioreactor in an exponential phase of growth. The microorganisms can then be delivered on a continuous or periodic basis to an environment containing contaminants and/or waste products for effectively bio-augmenting the bio-degradation of these contaminants and/or waste products. Such a system would require less maintenance and therefore be less expensive to operate. The present invention overcomes the shortcomings of existing systems.
SUMMARY OF THE INVENTION
The present invention provides a waste bio-augmentation system that adjusts the environment to be treated to a condition that is more conducive for bio-degradation of waste by introducing activated microorganisms designed for that purpose. Activated microorganisms are microorganisms that are in the exponential phase of growth. These microorganisms are more efficient in the bio-degradation of waste than microorganisms that are not in the exponential phase of growth.
The bio-augmentation system comprises an apparatus for delivering activated, preconditioned, microorganisms to an environment to be treated comprising:
a first container comprising a bioreactor chamber comprising organic nutrients, inorganic nutrients and microorganisms;
a second container comprising a mixture of inorganic and organic nutrients;
a controller comprising:
a first independent pumping means for pumping inorganic and organic nutrients to the bioreactor from the second container, the first pumping means being in contact with the second container and the bioreactor; and
a second independent pumping means for delivering a portion of the fluid from the bioreactor to the environment to be treated, the second pumping means being in fluid communication with the bioreactor and an environment to be treated.
The present invention also provides a method for the biological treatment of wastes comprising:
a) inoculating a bioreactor with a mixture comprising an aqueous solution of organic nutrients, inorganic nutrients, microorganisms that degrade waste;
b) incubating the microorganisms;
c) dosing a portion of the aqueous solution in the bioreactor to the environment to be treated;
d) replenishing the aqueous solution removed from the bioreactor with organic and inorganic nutrients; and
e) repeating steps c) and d) according to a pre-determined schedule.
The present invention also provides a composition containing oleate used to feed microorganisms in the bioreactor comprising:
metal-oleate, MgSO 4 , CaCl 2 , Na 2 HPO 4 , K 2 HPO 4 , ferric NH citrate, KHCO 3 , NaCl, Dextrose, Citrate, Yeast Extract, Whey Extract, NH 4 NO 3 , NH 4 Cl, CoCl 2 .6H 2 O, CuSO 4 , Na 2 EDTA, Molybolic Acid, MnCl 2 .4H 2 O, ZnSO 4 .7H 2 O, Vitamin A, Vitamin D, Vitamin E, Vitamin K, Thiamin, Riboflavin, Niacin, Vitamin B 6 , Folic Acid, Vitamin B 12 , Biotin, Pantothenic Acid, Calcium, Iron, Phosphorous, Iodine, Magnesium, Zinc, Selenium, Copper, Mn, Chromium, Molybdenum, Chloride, Potassium, Boron, Nickle, Silicon, Tin, Vanadium and trace elements. In addition, the above composition can also include one or all of the following anti-oxidants: Ascorbyl Palmitate, BHT, and alpha-Tocophenol in about 0.05% by weight.
DETAILED DESCRIPTION OF THE INVENTION
The present invention is further described in conjunction with the figures. As shown in FIG. 1, the bio-augmentation system 10 embodies the present invention. The bio-augmentation system 10 includes (i) a bioreactor 11 having a bottom 12 , a top 13 , and a concentric side wall 14 connecting the top to the bottom making a closed container (ii) a food supply 30 and (iii) a controller 40 . The apparatus may be of any shape or size, providing that the bioreactor container is essentially closed to the environment, i.e. having only controlled contact with the environment.
The controller 40 comprises several components that control and maintain conditions in bioreactor 11 that are necessary to keep the microorganisms of the bioreactor in the exponential phase of growth. A first pump 46 is connected to nutrient supply 30 and bioreactor 11 . This pump draws inorganic and organic nutrients from the nutrient supply 30 , via nutrient influent tube 31 . The pump 46 delivers the nutrients to the bioreactor 11 via nutrient effluent tube 32 .
The nutrient supply 30 contains organic and inorganic nutrients is provided as a complete food cup, or is in the form of liquid, powder or gel. The mode of delivery of these nutrients to the bioreactor 11 will depend on the physical state of the nutrients being transferred. For example, if the nutrient supply is in powder form it can be delivered via an automatic “hopper”. A hopper is a container storing dry granular/powder material positioned above the bioreactor 11 so that the dry nutrients can be supplied to the bioreactor 11 according to a predetermined schedule or on demand via a release port. When the release port (not shown) is opened, the dry organic and inorganic nutrients are transferred to the bioreactor 11 by gravity. When the release port is closed, the nutrients are no longer delivered to the bioreactor 11 . In one embodiment, the hopper contains a “shifter” that periodically agitates the dry nutrients stored in the hopper so that they do not pack together and block the release port.
If the organic and inorganic nutrients are in liquid form, they are delivered to the bioreactor 11 via effluent tube 32 by first pump 46 . The first pump 46 can be a peristaltic pump, pneumatic pump or vacuum pump. It is clear to those skilled in the art that other liquid delivery systems may also be used to deliver the liquid organic and inorganic nutrients to the bioreactor 11 . In addition, when a gel-based nutrient mixture is used, the nutrients are delivered by a displacement means. The displacement means, for example be a mechanical extractor that squeezes the gel from a container to the bioreactor. Other means for delivering the nutrients to the bioreactor are also possible and are intended to be within the scope of the present invention.
In another embodiment, the controller 40 is equipped with a timer 50 that activates the first pump 46 to dispense the organic and inorganic nutrients to the bioreactor 11 according to a pre-determined schedule. If the dry nutrient hopper described above is used, the timer 50 is used to open the release port of the hopper according to a pre-determined schedule. The timer 50 can be programmed to activate feeding on an hourly or daily basis. The feeding schedule depends on the particular mixture of microorganisms used in the apparatus, the desired cell concentration and the number of times a day that the microorganisms are fed. The timer 50 may be equipped with a programmable computer chip (not shown), which can be used to store scheduling information for dosing the inorganic and organic nutrients to the bioreactor 11 .
The controller 40 also contains a second pump 47 that operates independently from the first pump 46 and is connected to the bioreactor 11 via influent tube 48 . Influent tube 48 transports fluid containing microorganisms, inorganic and organic nutrients, as well as water from the bioreactor 11 to the second pump 47 . The second pump 47 then delivers this fluid to the environment to be treated 60 via effluent tube 49 . As with the delivery of inorganic and organic nutrients to the bioreactor 11 , this process can be regulated by the controller according to a pre-determined schedule programmed into the timer 50 of the controller 40 .
Maintaining a constant fluid level in the bioreactor 11 is necessary to assure that the microorganisms in the bioreactor remain in the exponential phase of growth. To maintain this constant fluid level, the amount water supplied to the bioreactor must be essentially equal to the amount of fluid removed from the bioreactor and dosed to the environment to be treated. When these two amounts are equal, a constant fluid level is maintained in the bioreactor. If more fluid is removed from the bioreactor than added, water must be supplied to the bioreactor in order to reestablish the fluid level. To accomplish this, water is supplied to a solenoid 41 by influent water supply tube 42 . Supply tube 42 is attached to a continuous water supply, i.e. a faucet, at one end and to the solenoid 41 of the controller 40 at the other. When the solenoid 41 is opened, incoming water is supplied to the bioreactor 11 via effluent water tube 43 . When the solenoid 41 is closed, incoming water can no longer enter the bioreactor 11 .
To regulate the opening and closing of the solenoid, a fluid level sensor 17 , i.e. float switch, is placed in the bioreactor 11 and is in communication with solenoid 41 via wire 52 . Once the sensor 17 senses that the level of fluid in the bioreactor 11 has fallen below a predetermined level, this information is communicated to solenoid 41 via wire 52 . As a result, the solenoid 41 switches to the open position and water flows into the bioreactor 11 via effluent water tube 43 . When the fluid level in the bioreactor reaches a particular level, the level sensor 17 communicates this to the solenoid 41 via wire 52 . As a result, the solenoid 41 switches to the closed position and water stops flowing into bioreactor 11 from the incoming water supply. In another embodiment, effluent water tube 43 is equipped with a backflow valve 44 that prevents the fluid in the bioreactor, which contains microorganisms, from backing up into the effluent water tube 43 . This reduces the chance of contaminating the external water supply with microorganisms.
In another embodiment, the controller 40 is equipped with an air supply 45 that provides air, preferably oxygenated air, to the bioreactor via air supply tube 18 . The air supply 45 can be a pump that delivers air to the bioreactor 11 . In the alternative, the air supply 45 can be a pressurized air canister that provides oxygenated air to the bioreactor 11 . The air supply tube 18 is connected to the air supply 45 at one end, enters the bioreactor 11 and terminates in the bioreactor solution containing nutrients and microorganisms at the other end. The air supply tube 18 may be open-ended or connected to an air provider 52 , which supplies air through a plurality of openings instead of one opening. The air supply 45 may be constantly operating or attached to an oxygen sensor that provides oxygen concentration information to the controller.
When the level of oxygen in the solution of the bioreactor 11 falls below a pre-determined value, the sensor relays this information to the controller 40 . The controller 40 then activates air supply 45 , which provides oxygenated air to the bioreactor solution until the oxygen concentration in the bioreactor 11 is re-established. Alternatively, an air supply 45 is activated directly without going to the controller 40 or is continuously supplying oxygen to the bioreactor
The apparatus may also be fitted with an exhaust vent 21 on its surface. The exhaust vent 21 extends through the surface of the apparatus so that the internal environment of the bioreactor is in communication with the external environment. In one embodiment, the exhaust vent 21 is fitted with a biofilter 15 that allows excess gas to be released from the bioreactor 11 , while preventing microorganisms from being released into the atmosphere. The biofilter 15 may be the type currently available on the market from Millipore Corp., i.e., Avervent 50.
The bioreactor 11 may also be equipped with an overflow tube 16 that has a first end positioned either above or below the fluid level in the bioreactor and a second end open to the external environment. Preferably, the overflow tube 16 is connected to a tube that directs overflow to the environment to be treated, i.e., drain line or grease trap. In one embodiment, the first end of the overflow tube 16 is positioned below the fluid level in the bioreactor and the second end that is exposed to the external environment curves downward so as to prevent air from entering the bioreactor. Since the first end of the overflow tube 16 is below the fluid level of the bioreactor 11 and the second end curves down, air is unable to enter the tube. In the alternative, a ball valve can be placed in the overflow tube to prevent air from escaping the bioreactor.
Pressure caused by the build up of excess fluid in the bioreactor forces fluid up the overflow tube 16 and out of the bioreactor 11 . As the level of fluid in the bioreactor 11 returns back to normal, fluid in the overflow tube 16 recedes from the tube and no additional fluid is released.
The bioreactor 11 may also be equipped with a series of sensors designed to monitor various conditions of the bioreactor 11 , including pH, temperature, and cell concentration. In one embodiment, a temperature sensor i.e. thermometer, is positioned in the solution of the bioreactor 11 and may be directly attached to a heater 19 . The heater 19 can be either periodically activated when information is reversed by the controller from the temperature sensor that the temperature of the solution in the bioreactor has fallen below a pre-determined temperature. More preferably, the temperature sensor/heater is an all-in-one unit. In other words, the heater is activated independent of the controller. In any event, either the controller 40 or the all-in-one unit activates the heater 19 as needed in order to maintain a temperature in the bioreactor 11 of about 40° F. to about 120° F. Preferably the temperature of the bioreactor 11 is maintained at about 70° F. to about 100° F. More preferably, the temperature is maintained at 90° F. In addition, the temperature of the bioreactor 11 can be adjusted to the optimum temperature of the particular microorganisms used in the bioreactor 11 .
In another embodiment, the bioreactor 11 is also equipped with an optical density sensor 22 which detects the turbidity of the solution in the bioreactor 11 . The higher the turbidity reading in the bioreactor 11 , the higher the viable cell concentration. When the turbidity of the solution in the bioreactor 11 drops below a critical level, an alarm (not shown) is activated. The alarm maybe in the form of a flashing light or may be audible. In one embodiment, the alarm is hooked up to a computer via telephone lines which relays the sounding of the alarm to a central station. At this station the problem can be assessed and a repair unit dispatched if needed.
In still yet another embodiment, the apparatus 10 is equipped with a conductivity sensor 23 which is used to measure the ion concentration in the bioreactor 11 . As with the turbidity sensor, the conductivity sensor 23 may be attached to an alarm which is activated when the ion concentration fluctuates above or below a pre-determined level. This pre-determined level is between about 80 microsiemans and about 800 microsiemans. More preferably the ion concentration is 150 microsiemans. The alarm may also be hooked up to a computer via telephone lines which relays the change in ion concentration in the bioreactor to a central station. As with the optical sensor, the central station can assess the problem and dispatch a repair unit if needed.
In another embodiment, a pH meter is used to measure the pH of the bioreactor. One skilled in the art would realize that other measuring tools can be used to meter and regulate the physical conditions in the bioreactor.
The present invention also includes a method for the bio-augmentation of a contaminated environment using pre-acclimated microorganisms. FIG. 2 represents a flow chart that illustrates a series of steps which are included in the method. The method includes the following steps:
STEP 1) inoculating or restarting the bioreactor with about 10% to about 50% of the total volume of the bioreactor, preferably about 20% to about 40% and most preferably about 25% to about 35% of the total volume of the bioreactor with a starter culture;
STEP 2) incubating the microorganisms of the starter culture in the bioreactor for a period of about 12 to about 96 hours, preferably about 24 to about 48 hours and most preferably about 12 to about 24 hours, or until the microorganisms are in the exponential phase of growth without removing any of the solution (i.e. no dosing);
STEP 3) dosing a pre-determined amount of fluid containing microorganisms from the bioreactor when the starter culture is fully in the exponential growth phase and delivering it to the environment to be treated;
STEP 4) replenishing the amount of solution removed form the bioreactor with water, and organic and inorganic nutrients; and
STEP 5) repeating Steps (3) and (4) according to a pre-determined schedule.
In another embodiment, step 2 above is completed outside the bioreactor and poured into the bioreactor at after the microorganisms are in the exponential phase of growth.
The microorganisms in the starter material used in Step 1 may vary upon the type of contaminant to be treated. In one embodiment, where the microorganisms are used to degrade hydrocarbons, i.e. grease, the starter material contains at least one microorganism selected from the group consisting essentially of Baccilus licheniformis, Bacillus subtilis, Pseudomonas fluorescens E, Pseudomonas putida, Enterobacter cloacae, and Bacillus thuringienis. The starter material will have a concentration of cells of at least 1×10 4 ×per fluid ml as well as the essential inorganic and organic nutrients to maintain the cell culture in the exponential phase of growth. The content and concentration of the inorganic and organic nutrients in the food will vary with the type of microorganism used in the apparatus.
In one embodiment, a composition containing organic and inorganic nutrients that is used as part of a starter material, comprises the following nutrients:
a metal-oleate, preferably K-oleate, and one or more of the following components;
magnesium sulfate, calcium chloride, potassium phosphate, sodium phosphate, sodium EDTA, sodium hydroxide, ferric NH citrate, potassium bicarbonate, sodium chloride, dextrose, citrate, yeast extract, whey extract, ketrol, ammonium nitrate, ammonium chloride, glycerin, Tween 20, Tween 80, corn oil, Simethlycone, and trace elements that include but are not limited to copper sulfate, cobalt(II) chloride, Sodium EDTA, Molybolic acid, MnCl 2 -7H 2 O, and zinc sulfate.
Preferably the composition described above comprises about 50 to about 60 weight % of water, about 20 to about 30 weight % K-oleate, about 2 to about 3 weight % glycerin, about 3 to about 10 weight % of vegetable oil and less than about 1 weight % of compounds selected from the group consisting essentially of MgSO 4 , CaCl 2 , Na 2 HPO 4 —7H 2 O, K 2 HPO 4 , NaCl, Dextrose, Citrate, Yeast Extract, Whey Extract, Trace elements, Sodium EDTA, Keltrol, Ferric NHcitrate, NaOH, NH 4 NO 3 , NH 4 Cl, Tween 20, Tween 80, and Simethlycone. Most preferably the vegetable oil is a mixture of about 4 to about 5 weight % of corn oil and about 5 to about weight 6% canola oil/ peanut oil.
The composition described above can be prepared by mixing metal-oleate, glycerin, Tween 20, Tween 80, water, and Keltrol in a mixing kettle. MgSO 4 , CaCl 2 , Sodium EDTA is added to 1 gallon of water and the pH is brought to about 8 to about 10, preferably about 9 using about 10N NaOH. This mixture is then added to the mixing kettle and is mixed for about 2 minutes. To about 5 gallons of water the Na 2 HPO 4 —H 2 O and K 2 HPO 4 is added. The pH is brought to about 8 to about 10, preferably about 9 using about 10N NaOH. This mixture is added to the mixing kettle after 2 minutes of mixing. In about 8 gallons of water the NaCl, Dextrose, Citrate, Yeast Extract, Whey Extract, NH 4 NO 3 , NH 4 Cl, CoCl 2 .6H 2 O, CuSO 4 , Na 2 EDTA, Molybolic Acid, MnCl 2 .4H 2 O, ZnSO 4 .7H 2 O, Vitamin A, Vitamin D, Vitamin E, Vitamin K, Thiamin, Riboflavin, Niacin, Vitamin B 6 , Folic Acid, Vitamin B 12 , Biotin, Pantothenic Acid, Calcium, Iron, Phosphorous, Iodine, Magnesium, Zinc, Selenium, Copper, Mn, Chromium, Molybdenum, Chloride, Potassium, Boron, Nickle, Silicon, Tin and Vanadium are mixed.
In a separate container dissolve Sodium EDTA and ferric NHcitrate in about 200 ml of hot water and add to the mixture above. The 8 gallon mixture bring the pH to about 9 to about 10, preferably about 9 and add to the mixing kettle. Finally add the corn oil and canola oil to the mixing kettle and sprinkle NH 4 NO 3 and NH 4 Cl into the mixing kettle. Mix thoroughly and fill dispensing container immediately. An anti-foaming agent may be added to the kettle prior to dispensing. The pH of the final mixture should be about 9 to about 10, preferably about 9.3 to about 9.6. As stated above, when the above composition is used as a starter material, at least one microorganisms selected from the group consisting essentially of Baccilus licheniformis, Bacillus subtilis, Pseudomonas fluorescens E, Pseudomonas putida, Enterobacter cloacae, and Bacillus thuringienis may be added prior to inoculation of the bioreactor. It is within the scope of the invention to substitute microorganism not listed that are capable of digesting waste.
While the invention has been illustrated and described with respect to specific illustrative embodiments and modes of practice, it will be apparent to those skilled in the art that various modifications and improvements may be made without departing from the scope and spirit of the invention. Accordingly, the invention is not to be limited by the illustrative embodiment and modes of practice. | The invention is directed to an apparatus for delivering activated microorganisms to an environment to be treated. The apparatus has a bioreactor containing microorganisms, a supply of organic and inorganic nutrients and a controller. The controller maintains the conditions of the bioreactor so as to maintain the microorganisms in the exponential phase of growth. The controller also doses a portion of the fluid in the bioreactor to the environment to be treated. The invention also provides a method for the biological treatment of wastes and an organic and inorganic composition used to feed the microorganisms in the bioreactor. | 2 |
PRIORITY
This application claims the benefit of priority based on U.S. Provisional Application Ser. No. 61/494,587 filed on Jun. 8, 2011, which is hereby incorporated by reference in its entirety.
FIELD
The present invention relates in general to green computing, the minimization of computing power consumption. In particular, the present invention relates to a super operating system for a heterogeneous computer with a low-power master processor controlling standard x86 architecture to make a heterogeneous system for performance computing at minimized computing power consumption.
BACKGROUND
Computers of various sorts have become an indispensable equipment of modern civilization. Intel x86 (original architecture designed by Intel Corp. of Santa Clara, Calif. and evolved into the latest 64-bit CISC architecture by Advanced Micro Devices, Inc. of Sunnyvale, Calif.) has long dominated mainstream computing. Meanwhile, the world of non-x86 computing of commercial significance is currently dominated by the ARM processor (of the RISC ARM architecture developed by the ARM Holdings plc of Cambridge, United Kingdom) in mobile computing devices that include smart phones and touch-screen devices. From the perspective of green computing, problems of both x86 and non-x86 computing are as follows.
There is the need for green computing to cut x86 desktop idling power consumption. x86 computing is good for applications requiring computing power. With a global installation base of hundreds of millions of home and office desktop and portable computers, professional high-performance workstation computers, and server computers for various net-based commerce, computing energy consumption has become an environmental issue. One of the main issues is with computing idling—times when a computer is not used but not shut down.
There are power reduction efforts such as the Energy Star, an international standard originated in the United States and adopted by many other countries that achieve some level of computing power saving. The x86-based mainstream computer industry also has standard power management. For example, the Advanced Configuration and Power Interface (ACPI), an open industry standard, allows an operating system to implement direct control of the power-saving features of the computer hardware.
However, it is frequently difficult for x86-based mainstream desktops and laptops to achieve real green operation for most users due to inconvenience and limited power management built in. For many computer users, the sleep/stand-by/hibernation power management modes of the ACPI may be complicated to comprehend less finding a way to adjust for a best parameter setting for a computer to be both convenient to use and power-saving. Meanwhile, for more sophisticated computing such as that involving multiple sessions of virtual computing, instead of a smooth power management, ACPI is more prone to either crashing the computer or having difficulty in dealing with the VM sessions.
Thus, there is plenty of room for significant energy conservation by desktops due to their huge number.
There is the need for green computing to make x86-based smart mobile device practical. Also because of the imperfection of the available power management technology in the standard x86 world, x86-based smart personal devices (for example, x86-based cell phones) have so short battery life to be practical. In fact, no rigorous commercial x86-based smart phone is in existence. Most x86-based laptop computers have problem sustaining one whole hard-working day on battery out on the road. The result is the inconvenience of x86 application software access when out of office or home.
There is the need for non-x86 device to access x86 software base. The ARM processor has been developed for power-conserving applications necessary for mobile, especially smart phone applications. But, it is just not for serious computational applications. And essentially it has no practical direct access to the x86 software base. As Windows software remains to be the dominant in many aspects of daily life and business, non-x86's difficulty in access to x86 applications spells an inconvenience. Users either out on the road or in office need to have both hardware at hand to be able to have access to both the ARM-dominant mobile and x86-dominant Windows applications.
There is the need for a cross-OS computer system for simultaneous, integrated and seamless access to mixed applications. As the access to both x86 Windows and ARM smart phone applications become more a daily necessity for many, the need for a computer device that provides simultaneous access to both becomes real. Current x86-based architecture (and some other non-x86) allows for the execution of Windows and non-Windows software applications simultaneously on the same computer hardware through virtual computing technology. For example, an x86 computer can have either a Linux, a Windows or other host operating system that supports a number of guest virtual computers each running one of a different number of the supported operating systems. However, the emulation by the host processor of the instruction sets of other non-x86 guest OS consumes processing power. While this is acceptable for desktops, it is not for smart mobile devices for the obvious reason of battery life.
In an attempt to combine the functionalities of cell phone and a personal computer among other devices, Cupps et al. disclose an electronic device in a series of U.S. Patents and Applications that combines the hardware of an x86-based architecture and an ARM processor-based embedded system. For example, in US2002/0173344 “Novel personal electronic device,” Cupps et al. describe a device that uses a low-powered system processor such as an ARM to serve as the system controller of the entire device that is essentially an x86-based computer.
The Cupps et al. electronic device is one that essentially has a cell phone-capable embedded ARM processor inserted into an x86 computer having its own PC processor. The ARM is connected to the North and South Bridges of the x86 architecture in the same way the original PC processor does. Cupps et al. describe that the low-power ARM system processor is thus able to act as the master processor—on top of the performance PC processor of the basic x86 architecture—of the electronic device.
However, by placing the ARM processor on the high-speed buses (PCI-e) of the North Bridge the same way as the display controller and the memory subsystems of the x86 architecture, the Cupps et al. device has limited “master control” over the entire device. In fact, rather than the supreme master processor of the entire electronic device, the bus connection of the ARM processor in the device categorizes itself as a bus master device under the standard x86 architecture. With this system architecture, because the main x86 architecture under the PC processor must maintain a complete and sound power management status under, for example, ACPI, any slightest disruption to breach the integrity of this status results in the lost of data and the need for a complete reboot. Most frequently, the ARM processor in the Cupps et al. device will be rebooting the PC processor-based main x86 system for whichever heavier tasks that call for the processing power of the PC processor.
There is therefore the need for a super operating system that runs a heterogeneous computer system to implement best minimization of the computing power consumption without sacrificing the computing capability to make a green x86 computer.
There is also the need for a super operating system that runs a heterogeneous computer system to implement best minimization of the computing power consumption to make a practical x86-based smart mobile device by sustaining at least one workday on battery per battery charging.
There is also the need for a super operating system that runs a heterogeneous computer system to make a non-x86 smart mobile device capable of access to the x86 software base.
This is also the need for a super operating system that runs a cross-OS heterogeneous computer system to provide simultaneous, integrated and seamless access to software applications of different OS's.
SUMMARY
The present invention achieves the above and other objects by providing a heterogeneous computer system comprising an x86 core having an x86 processor and an x86 computing architecture; a hypervisor processor having a performance capability lower than the x86 processor; and a bridge logic connecting the hypervisor processor to the x86 core via the local bus of the x86 processor; wherein the hypervisor processor executing software tasks it has sufficient performance to handle and putting the x86 processor to idle (sleep, hibernation, shutdown); and the hypervisor processor bringing up the x86 processor to execute software tasks its has insufficient performance to handle.
The present invention further achieves the above and other objects in certain embodiments by providing a super operating system for a heterogeneous computer system for executing software. The heterogeneous computer system has one or more first processors; a processor supporting logic supporting the at least one first processor for executing tasks of the software; and a second processor consuming less power than the one or more first processors. The super operating system has a performance operating system for the at least one performance processor; a hypervisor operating system for the hypervisor processor; and a heterogeneous hypervisor software layer on top of both the hardware subsystems for the performance and the hypervisor processors and below both the performance and hypervisor operating systems. Under the super operating system, the second processor, supported by the processor supporting logic, executes tasks of the software that the second processor has sufficient processing power to handle and puts the one or more first processors to a power-conserving state.
The present invention further achieves the above and other objects in certain embodiments by providing a super operating system for a heterogeneous computer system for executing software. The heterogeneous computer system has at least one performance processor; a processor supporting logic supporting the at least one performance processor for executing tasks of the software; and a hypervisor processor consuming less power than the at least one performance processor. The super operating system has a performance operating system for the at least one performance processor; a hypervisor operating system for the hypervisor processor; and a heterogeneous hypervisor software layer on top of both the hardware subsystems for the performance and the hypervisor processors and below both the performance and hypervisor operating systems. Under the super operating system, the hypervisor processor executes tasks of the software that the hypervisor processor has sufficient processing power to handle and puts the at least one performance processor to a power-conserving state. The hypervisor processor brings the at least one performance processor out of power-conserving state to execute tasks of the software that the hypervisor processor has insufficient processing power to handle. The at least one performance and hypervisor processors simultaneously execute tasks of the software that require combined processing power of all processors.
The present invention further achieves the above and other objects in certain embodiments by providing a super operating system for a heterogeneous computer system for executing software. The heterogeneous computer system has at least one performance processor with a local processor bus; a processor supporting logic supporting the at least one performance processor for executing tasks of the software; a bridge logic connecting the hypervisor processor to the processor supporting logic via the local processor bus; and a hypervisor processor consuming less power than the at least one performance processor. The super operating system has a performance operating system for the at least one performance processor; a hypervisor operating system for the hypervisor processor; and a heterogeneous hypervisor software layer on top of both the hardware subsystems for the performance and the hypervisor processors and below both the performance and hypervisor operating systems. Under the super operating system, the hypervisor processor, supported by the processor supporting logic, executes tasks of the software that the hypervisor processor has sufficient processing power to handle and puts the at least one performance processor to a power-conserving state. The hypervisor processor brings the at least one performance processor out of the power-conserving state to execute tasks of the software that the hypervisor processor has insufficient processing power to handle. The at least one performance and hypervisor processors simultaneously execute tasks of the software that require combined processing power of all processors.
The detailed technology and preferred embodiments implemented for the subject invention are described in the following paragraphs accompanying the appended drawings for people skilled in this field to well appreciate the features of the claimed invention. It is understood that the features mentioned hereinbefore and those to be commented on hereinafter may be used not only in the specified combinations, but also in other combinations or in isolation, without departing from the scope of the present invention.
BRIEF DESCRIPTION OF THE DRAWINGS
FIG. 1 schematically outlines the block diagram of an implementation of the heterogeneous computer system of the present invention that has a hypervisor processor added to standard x86 architecture via a bridge circuit chip.
FIG. 2 schematically outlines the block diagram of another implementation of the heterogeneous computer system of the present invention that has a hypervisor processor core and its necessary bridge logic built on the same semiconductor chip for addition to standard x86 architecture.
FIG. 3 schematically outlines the block diagram of another implementation of the heterogeneous computer system of the present invention that has a hypervisor processor core and its necessary bridge logic built on the same semiconductor of a multi-core x86 processor for direct drop-in in the CPU socket of a standard x86 computer board.
FIG. 4 schematically outlines the block diagram of another implementation of the heterogeneous computer system of the present invention that has a reduced-power x86 core serving as the hypervisor processor on the same semiconductor of a multi-core x86 processor for direct drop-in in the CPU socket of a standard x86 computer board.
FIGS. 5 and 6 schematically outline the block diagram of another embodiment of the computer system of the present invention as an x86-based smart mobile device.
FIG. 7 schematically illustrates the concept of the bridge logic used for the construction of the heterogeneous computer system of the present invention.
FIG. 8 schematically illustrates the connection by the bridge logic of the hypervisor processor and the main processor of the x86 architecture onto the front-side bus of the x86 chipset in the inventive heterogeneous computer system.
FIG. 9 schematically outlines the basic functional elements in the bridge logic in accordance with a preferred embodiment of the present invention.
FIG. 10 schematically illustrates the logic circuit elements of the bridge logic of FIG. 9 in more detail.
FIG. 11 schematically illustrates the circuit block diagram of the inventive heterogeneous computer system in accordance with a preferred embodiment of the present invention.
FIG. 12 schematically illustrates the logic circuit elements in the bridge logic in accordance with a preferred embodiment of the present invention.
FIGS. 13-15 respectively illustrate the operating modes of the inventive heterogeneous computer system described in FIGS. 8-12 .
FIGS. 16-19 respectively illustrate the control algorithms for bringing up the heterogeneous computer system.
FIG. 20 schematically illustrates the super OS that operates the heterogeneous computer system for seamless cross-OS software application.
FIGS. 21-24 respective illustrate the operating modes of the inventive heterogeneous computer system described in FIGS. 8-12 to support seamless cross-OS software application.
DETAILED DESCRIPTION
The following example embodiments are provided to illustrate but not to limit the present invention.
The inventive computer system of the present invention is based on a hetero-processor system that delivers green computing—deep green computing. A low-power mastering “hypervisor” processor is added to the mainstream standard x86 architecture via a bridging logic circuitry to make a heterogeneous computer system that's both powerful and energy conserving for green performance computing.
The inventive heterogeneous computer system achieves to reduce as much possible power consumption in x86 computing so that (1) The entire x86-dominated mainstream computing can contribute carbon reduction of significance; and (2) The vast x86 software base can become truly practically accessible to mobile users for our mobile needs. The inventive heterogeneous computer system also achieves cross-OS computing to allow for simultaneous, integrated and seamless access to software applications from different OS's.
In other words, the heterogeneous computer system of the present invention seeks to address these issues and achieve at least two main goals. First, the inventive computer system provides a solution to a portable smart device, a new breed of smart phone to be specific, that has access to the vast existing x86 application software base while is also sufficiently power-conserving so as to sustain at least one full workday on battery. Such one mobile device will replace the cumbersome smart phone and laptop pair for many business travelers.
Secondly, and more importantly, the inventive computer system can realize deep green computing in mainstream computers including desktop, workstation and server computers. The idea is that any power conservation contributed by each computer out there adds up to a huge global reduction in computer power consumption.
Meanwhile, while fulfilling these objectives, the heterogeneous computer system of the present invention also achieves to allow the simultaneous, integrated and seamless access to software applications of different OS's using the same hardware.
Note that the term “x86 applications” in this invention refers to the broader sense of all x86 software applications that can be executed under various OS available to the x86 hardware architecture. Thus the term means all software applications written for OS's such as Windows, Linux, Mac OS, Solaris etc., all those currently supported by the x86 architecture.
Also, “hypervisor” in computing normally means virtual machine monitor—VMM, more of a software technique than hardware. However, the terms is also used herein to refer to the master processor, the low-power ARM, in the asymmetric hetero-processor system of this invention that supervises the x86 processor, the performance but power-consuming element of the system that is essentially the slave processor under the master ARM. This terminology is selected also because the master processor does in fact monitor and control the virtual machines necessarily embedded in the software system of the present invention.
It is so named because the ARM master processor is conceptually one level higher than the x86 processor that supervises the x86 hardware, the main hardware of a heterogeneous computer system of the present invention—meaning that the master ARM “hypervises” its slave x86, which supervises the main x86 hardware.
Also, the term performance processor is used to mean the main x86 processor in the standard x86 architecture. It is thus named to reflect the fact that the x86 processor in the inventive heterogeneous computer system is responsible for the serious number crunching jobs.
To find a solution for computers to minimize power consumption without sacrificing computing power is of course a known technical issue with known practices. In mobile computing (laptop, touch-screen computers and smart phones, etc.), power management must be addressed brilliantly to sustain operation for as long as possible—with a life of at least one work day out on the road. In mainstream desktop computing, power management is important because of the huge global installation base—a global environmental issue comparable to MPG performance in passenger cars.
But the conventional power management would not be able to reach the goal of having an x86 architecture work sufficiently power-conserving for practical road applications. This is the limitation of the present-day x86, it is simply not designed so.
The solution lies in the hetero-processor concept. For such a heterogeneous computer system to be commercially successful, the computer system must be compatible to the existing industry standards to a degree as high as possible. It is simply impractical to think of changing the Wintel with so huge a momentum. The heterogeneous computer system solution must fit the existing, not the other way around. And this means the adjustment must be as slight as possible both in hardware and software.
A: Heterogeneous Computer System with a Bridge Logic
From the perspective of system hardware architecture, a heterogeneous computer system of the present invention has a “hypervising” processor that resides on the local (front side) bus of the standard x86 architecture. See FIGS. 1-4 . This is fundamentally different from the Cupps et al. electronic device described above which connects its system processor to the North bridge of the x86 architecture via the system bus.
FIG. 1 schematically outlines the block diagram of an implementation of the heterogeneous computer system of the present invention that has a hypervisor processor added to standard x86 architecture via a bridge circuit chip. In a preferred embodiment of the present invention the heterogeneous computer system 100 has a standard x86 architecture 160 , which, by itself, constitutes a complete x86 computer with its x86 CPU 120 and the supporting x86 chipset 162 .
The hypervisor processor 110 is added to the standard x86 architecture 160 via a bridge chip 140 that contains the digital electronic circuitry for the hypervisor processor 110 , an ARM, or a low-power x86 processor (such as 386 or even 286 ), to be inserted into the x86 architecture 160 via the front-side bus (FSB) 134 of the x86 CPU.
FIG. 7 schematically illustrates this concept of the bridge used for the construction of the heterogeneous computer system of the present invention. “Bridge Logic” means it is a bridging device (logic) that allows, for example in the system of FIG. 1 , the connection (attachment) of the hypervising ARM processor 110 to an existing x86-based computer system 160 . Within the context of the present invention, such a bridge device 407 as outlined in FIG. 7 functions as a three-way data switch 408 . In other words, data switch 408 here refers to a multiple-way switch, a 3-way T or Y switching device that allows data passage from either of the three to any one of the remaining two. Details of how this bridge logic works to insert the hypervisor processor into an x86 architecture will be described below.
FIG. 2 schematically outlines the block diagram of another implementation of the heterogeneous computer system of the present invention that has a hypervisor processor core and its necessary bridge logic built on the same semiconductor chip for addition to standard x86 architecture. In this embodiment of the present invention the heterogeneous computer system 200 has a standard x86 architecture 260 , which, by itself, constitutes a complete x86 computer with its x86 CPU 220 and the supporting x86 chipset 262 .
The hypervisor processor 210 in the form of an ARM or an x86 core is added to the standard x86 architecture 260 via a bridge logic 240 that contains the digital electronic circuitry for the hypervisor processor 210 to be inserted into the x86 architecture 260 via the front-side bus (FSB) 234 of the x86 CPU. In this example, the hypervisor processor 210 and the necessary bridge logic 240 are made on the same integrated chip, the hypervisor chip 242 .
FIG. 3 schematically outlines the block diagram of yet another implementation of the heterogeneous computer system of the present invention. It has a hypervisor processor core and its necessary bridge logic built on the same semiconductor of a multi-core x86 processor for direct drop-in in the CPU socket of a standard x86 computer board.
In this embodiment the heterogeneous computer system 300 is itself a standard x86 architecture, which, by itself, constitutes a complete x86 computer with its x86 CPU 344 and the supporting x86 chipset 362 . The x86 CPU 344 is a variant to its conventional counterpart. It consists essentially on the same semiconductor die of an x86 performance processor, for example the latest multi-core x86 320 , a hypervising ARM or low-end x86 core 310 , and the bridge logic 340 to bridge the hypervisor to the performance core via the front-side bus 334 .
FIG. 4 schematically outlines the block diagram of another implementation of the heterogeneous computer system of the present invention that has a reduced-power x86 core serving as the hypervisor processor on the same semiconductor of a multi-core x86 processor for direct drop-in in the CPU socket of a standard x86 computer board.
In this embodiment the heterogeneous computer system 400 is itself a standard x86 architecture that constitutes a complete x86 computer with its x86 CPU 446 and the supporting x86 chipset 462 . The x86 CPU 446 is another variant to the conventional counterpart. It consists essentially on the same semiconductor die of x86 performance processor cores 421 and 422 , and a hypervising reduced-power x86 core 410 . No bridge logic is necessary as the hypervisor core 410 implements a reduced instruction set of the performance cores 421 and 422 and shares the same internal bus. The hypervisor-equipped performance processor 446 is connected to the x86 chipset 462 in the same manner as standard x86 computer boards via the normal FSB 434 .
Literally, as shown in FIGS. 1-4 , the concept of constructing a heterogeneous computer system of the present invention is to add a power-sipping master, most likely an ARM at present, to an x86 computer. The idea is to have the low-power hypervisor processor awake all the time to hypervise the power-hungry workhorse x86. Under this concept, the x86 is a pure slave under the ARM hypervisor processor and can be put to deep rest to conserve energy and only called into action when the relatively low-performance can not, or is insufficient to, handle the task assigned to the system.
Depending on the main purpose of use of an inventive heterogeneous computer system, its x86 system can be the latest Intel 2 nd generation Core™ technology processor-based performance system for, CAD/CAM workstations, for example. Or, the selected x86 can be an Atom™-based low-power system for a mobile device that is intended to replace the smart phone-laptop pair for frequent business travelers.
Using existing x86 architectures, such heterogeneous computer system hardware can be constructed with ease. For commercial applications, the following solutions in FIGS. 1-4 are suitable for different computer hardware manufacturers along the computer industry supply chain.
The computer system architectures of FIGS. 1 and 2 constitute business to current computer motherboard and system makers. They can procure the ARM processor and the bridge chip to manufacture their products. The architecture of FIG. 3 , however, is dependent on whether or not any of the current x86 and compatible processor makers adopts this technology and make adjustments to their processor semiconductor to produce their versions of the heterogeneous computer system concept CPUs.
This is possible from the business perspective. For any of the current CPU makers, this concept involves relatively little semiconductor changes to their existing multi-core products but with so large potential impacts on the performance of computers made out of these new concept CPUs—green computing. FIG. 4 illustrates a vision of such an architecture that is most suitable for mainstream desktop/workstation computing.
FIGS. 5 and 6 schematically outline the block diagram of another embodiment of the computer system of the present invention as an x86-based smart mobile device. Such an x86 smart device has the functionalities of both a cell phone and an x86-based computer and can be used to replace the indispensable pair of mobile phone and laptop computer for business travelers.
In this example, similar as in the example of FIG. 1 , the smart phone-plus-laptop version of the heterogeneous computer system 500 has an x86 architecture 560 , which, by itself, constitutes a complete x86 computer with its x86 CPU 520 and the supporting x86 chipset 562 . To provide the cell phone functionality, a cellular communications unit 570 can be implemented as part of the x86 architecture.
The hypervisor processor 510 is connected to the x86 architecture 560 via a bridge chip 540 that contains the digital electronic circuitry for the hypervisor processor 510 , an ARM, to be inserted into the x86 architecture 560 via the front-side bus (FSB) 534 of the x86 CPU.
As is outlined by the enclosing phantom-line in FIG. 5 , when the x86 smart mobile device 500 works its cell phone functionality, the entire x86 core 560 including the x86 CPU 520 and the main x86 chipset 562 can be put to rest, with the exception of the cellular communications unit 570 , which is operated under the hypervising ARM processor 510 .
On the other hand, when the device 500 operates its portable computer to run, for example, Windows applications as illustrated in FIG. 6 , all components of the device 500 except the cellular communications unit 570 is activated. For example, a net banking application can be executed by the x86 system under the supervision of ARM. The low-power ARM provides hypervision all the time to determine when the x86 section of the device can be put to rest for the conservation of the battery energy.
In order to implement green computing so that the desktop implementation of the inventive heterogeneous computer system described in FIGS. 1-4 can conserve energy, so that the x86 smart mobile device such as described in FIGS. 5 and 6 can sip its battery energy in order to sustain an entire workday out on the road, and so that both can have simultaneous, integrated and seamless mix-OS software applications, the hardware described needs to have a corresponding system software to implement all that described. Such a software system will be described in detail below.
B: Bridge Logic for the Heterogeneous Computer System
FIG. 8 schematically illustrates the connection—by the bridge logic 6400 —of the hypervisor processor 610 and the main x86 processor 620 onto the front-side bus of the x86 chipset 662 in the inventive heterogeneous computer system. Underlying concept of the heterogeneous computer system of the present invention is the introduction of a supervising microprocessor—the hypervisor processor—to a powerful computer that already has its own capable microprocessor—the x86 processor. The concept is to have the hypervisor processor consume as little power as possible to stay active all the time when the heterogeneous computer system is powered up and manages the computational works of the performance x86 subsystem of the inventive apparatus. In such a heterogeneous computer system, the performance x86 subsystem is only brought out of rest to work whenever the hypervisor processor determines that an assigned computing task is beyond the capacity of the low-power hypervisor processor.
To do so, as described in the embodiments of FIGS. 1-4 and as is illustrated in more detail in FIG. 8 , the bridge logic circuit 6400 sits between the x86 performance processor 620 and the x86 chipset 662 of the standard x86 computer on the front-side bus. Literally the direct connection of an x86 processor to the North Bridge of the x86 chipset via the front-side bus in a normal x86 computer is interrupted by the introduction of the bridge logic 6400 . The original FSB connection between the x86 processor 620 and the North Bridge 6624 is still in place but broken down into two sections—FSB 6452 at the x86 processor side and FSB 634 at the chipset side—under control of the bridge logic 6400 . Meanwhile, the bridge logic 6400 sits similarly between the added hypervisor processor 610 and the FSB 634 connected to the North Bridge 6624 of the x86 chipset 662 .
The bridge logic 6400 includes a hypervisor operation logic 6410 , a processor instruction set/computer command translator logic or, grossly, the processor language translator logic, 6430 , and a high-speed bus switch 6407 . The bus switch 6407 has a switching rate compatible to the x86 processor FSB. As described in FIG. 7 , this bus switch 6407 is, preferably, a three-way switch, of which one port (A in the illustration) is directly connected to the FSB 6452 of the x86 processor 620 . A second port (B) of the switch 6407 is connected to the processor bus 6454 of the hypervisor processor 610 via the processor language translator logic 6430 . The third port (C) of switch 6407 is connected directly to the FSB 634 of the North Bridge of the chipset 662 .
Such a connection by the high-speed bus switch 6407 allows both the x86 performance processor 620 and the low-power hypervisor processor 610 to have access to the North Bridge 6624 of the x86 architecture via FSB 634 . Whenever the switch 6407 is set to connect its ports A and C, the performance x86 processor 620 can have direct connection to the North Bridge much like in a normal x86 computer.
On the other hand, when the switch 6407 is set to connect its ports B and C, the low-power hypervisor processor 610 can have access to the x86 chipset 662 . In case that the hypervisor processor 610 is another low-power x86 processor that operates the same—or a subset of—x86 processor instruction set as the performance x86, the processor language translator logic 6430 needs only provide a simple conversion between different levels of x86 instruction sets.
However, if the low-power hypervisor processor 610 is one that operates an entirely different instruction set—such as in the case of an ARM or a MIPS, the hypervisor processor 610 needs to mimic, or emulate, the performance x86 processor using the processor language translator logic 6430 . In this case, the translator logic 6430 translates, or converts, the hypervisor processor 610 native commands into the equivalent command of the performance x86 processor 620 using the native instructions of the performance processor 620 .
Essentially, the language translator logic 6430 translates between x86 and hypervisor (ARM for example) processor languages (instructions) so that the hypervisor 610 understands and fully monitors x86 activities in the computer system and that x86 processor 620 may take orders from hypervisor 610 . The translator logic 6430 also synchronizes exchanges of data between the high-speed x86 FSB 634 and the typically lower bus speed of the low-power hypervisor processor 610 , for example, the AMBA (Advanced Microcontroller Bus Architecture) bus normally adopted by ARM devices.
In other words, to facilitate the normally lower-performance hypervisor processor's access to the high-performance x86 architecture, the bridge logic 6400 must be equipped to do the translation of (1) the processor “language” and (2) bus communication electrical signal. Bus wrapper 6414 such as found in the examples of FIGS. 9 and 10 is responsible for this bus protocol conversion and implements conversion between data bus width, address bus lengths, and bus signal electrical levels, timing etc.
In a preferred embodiment as described in FIG. 8 , all such conversion can be implemented together with the hypervisor operation logic 6410 , which monitors the entire x86 activities under x86 processor to maintain an off-x86 copy of system status so that the x86 processor can pick-up operation seamlessly after being awaken. Hypervisor operation logic 6410 may also be able to translate ARM commands into x86 when the x86 processor 620 is put to rest and ARM runs x86 code through technologies such as virtual machine and on-the-fly command/instruction translation.
Note that the bridge logic 6400 can either be a passive digital logic run by the low-power hypervisor processor (ARM) or it may itself be a microprocessor-based active logic. Also, the performance x86 processor can be an Intel, an AMD, or a Cyrix processor and the low-power hypervisor processor can be an ARM, a MIPS or a reduced x86 core.
In all, bridge logic components switch 6407 , logic 6410 and logic 6430 work together to provide a bridging function so that the x86 processor 620 has direct access to the x86 architecture 662 under control of the hypervisor processor 610 for the implementation of performance tasks assigned to the heterogeneous computer system. And, on the other hand, the hypervisor processor 610 may have indirect access to the x86 architecture 662 when the x86 processor 620 is not needed.
Also note that the term “instruction set” as in the “microprocessor instruction set” of either the hypervisor or the performance processor of the inventive heterogeneous computer system described herein means the part of the computer architecture that is related to programming and includes the native data types, instructions, registers, addressing modes, memory architecture, interrupt and exception handling, and external I/O. Further, the term “commands” as in “computer commands” of either the hypervisor or the performance processor of the inventive heterogeneous computer system described herein means the artificial language that expresses computations that can be performed by a computer system.
FIG. 9 schematically outlines the basic functional elements in the bridge logic in accordance with a preferred embodiment of the present invention. Functionality of the processor instruction set translator logic 6430 in the bridge logic 6400 is provided by the peripheral status maintainer 6436 , the peripheral status table 6432 , and the peripheral IRQ controller 6434 . This keeps a constant record of the status of the peripherals attached to the heterogeneous computer system.
Meanwhile, functionality of the hypervisor operation logic 6410 of the bridge logic 6400 is provided by the FSB command handler 6412 and the bus wrapper 6414 . Essentially the FSB command handler 6412 monitors the computer commands performed by the performance processor 620 so that the set of peripheral status can be maintained as described above to keep track of the peripherals in the heterogeneous computer system (normally attached to the South Bridge of the x86 chipset 662 ) so that when the performance x86 is put to rest, it can pick up the right status after awaken.
On the other hand, when the performance x86 processor 620 is at rest, and the hypervisor processor 610 relies on the FSB command handler 6412 and the bus wrapper 6414 to translate its commands into x86 so that the x86 chipset can be accessed. Essentially the bus wrapper 6414 plays the role of a translating speaker for the non-x86 hypervisor processor 610 to “speak” the native x86 command language. This allows for the hypervisor processor 610 to have direct access to the x86 architecture resources regardless of either the performance processor 620 is at rest.
FIG. 11 schematically illustrates the circuit block diagram of the inventive heterogeneous computer system in accordance with a preferred embodiment of the present invention. In this example the bridge logic 7400 has a slightly different logic circuit arrangement. The bus switch 7407 is a four-way switch that still provides both the hypervisor 710 and the performance x86 processor's direct access to the x86 architecture. However, the command handler 7412 for the command translator logic and the peripheral status mapper 7438 for the hypervisor operation logic are on the fourth port of the bus switch 7407 . In this example, the command handler 7412 is responsible for the following tasks:
1, command queuing and command parsing.
2, translation of x86 commands into corresponding ARM commands.
3, translation of ARM commands into correspond x86 commands.
4, x86 status maintenance.
5, Direct or indirect access to peripherals.
The peripheral status mapper 7438 is responsible for the following tasks:
1, Peripheral mapping for the ARM processor.
2, Maintenance of peripheral status.
The bus switch 7407 has the following tasks:
1, bridges between the high-speed FSB (of Intel, AMD, Via-Cyrix performance processors) and the lower-speed AMBA bus (of ARM).
2, bridging for x86 direct or indirect access to the x86 architecture.
Also, the performance x86 processor may have its own working RAM 724 , and the hypervisor processor 710 is an embedded processor 712 , which may also have its own working RAM 714 and an on-board boot loader 716 .
FIG. 12 schematically illustrates the logic circuit elements in the bridge logic in accordance with a preferred embodiment of the present invention. The bridge logic 7400 is illustrated to be in cooperation with the x86 chipset and the two processors of the system. Bridge logic 7400 includes the same command handler 7412 as in FIG. 11 , which serves to translate the x86 codes into that of the low-power ARM hypervisor's and vice versa. The command handler 7412 can either be a dumb logic under ARM control or it can also be a processor-based command handler.
The peripheral status maintainer 7436 of the implementation of FIG. 12 is slightly different from the peripheral status mapper 7438 of FIG. 11 . With its own memory and/or registers, the PSM 7436 is a synchronizer that allows for the ARM hypervisor to have full grasp of exact status of the x86 main system. The status maintenance is so that (1) ARM can pick up x86's task (via, for example, the virtual computing technology) anytime with the correct system status, and (2) the x86 processor can pick up ARM's task (when, for example, ARM is under-powered for certain tasks) when brought back from rest (standby/sleep/hibernation) with the right status. Again, the PSM 7436 can either be a dumb logic operating under ARM control or it can also be a processor-based maintainer.
FIG. 10 schematically illustrates another example of the logic circuit elements of the bridge logic of FIG. 9 in more detail.
All embodiments of the inventive heterogeneous computer system described above in FIGS. 8-12 operate in one of three modes illustrated in FIGS. 13-15 . This first mode illustrated in FIG. 13 is much like what a conventional desktop computer is doing. The performance x86 processor 620 may be assigned a complex processing power-demanding CAD, or high-fidelity gaming job, in which the x86 processor 620 is working full load. Meanwhile, the hypervisor processor 610 is also active, monitoring and maintaining the computer system status so as to be ready for the performance x86 to be put to rest any time.
In the drawing, the double-head arrow pointing toward the processor 620 and the x86 chipset 662 along the FSB indicates that the processor 620 has its normal access to the x86 system. Meanwhile, the phantom-lined double-head arrow pointing toward the hypervisor processor 610 and the x86 chipset 662 along the FSB indicates that the hypervisor 610 is maintaining its monitoring of the entire system.
Heterogeneous computer system operation mode 2 illustrated in FIG. 14 signifies a scenario of, for example, an x86-based smart mobile device capable of cellular application made possible by the on-board hypervisor ARM processor. When such a smart device makes a cell call using its ARM, the performance x86 processor can be put to rest, as signified by the phantom processor 620 .
Heterogeneous computer system operation mode 3 illustrated in FIG. 15 signifies a scenario of, for example again, an x86-based smart mobile device that is simultaneously making a cell call using its ARM and making an Active-X-required remote banking Windows application out on the road. In this case the hypervisor processor 610 is active and performing its light communications task while simultaneously monitoring and maintaining system status. On the other hand, the performance x86 processor 620 is also active to perform its assigned remote banking task. Both ARM and x86 applications respectively under Android (for example) and Windows OS are performed at the same time, on the same heterogeneous computer system display screen, and can even exchange data to each other—a mixed-OS software application scenario performed seamlessly and simultaneously integrated on the same hardware as will be described below.
C: Boot Up Algorithm for the Heterogeneous Computer System
FIGS. 16-19 respectively illustrate the control algorithms for bringing up the heterogeneous computer system. Four routes are possible to bring up the inventive computer system from the status of power down:
Mode A: Only the low-power hypervisor processor system is booted up active.
Mode B: Performance x86 processor boots up after hypervisor processor system is active.
Mode C: Only the performance x86 processor system is booted up active.
Mode D: Hypervisor processor system boots up after the performance x86 system is active.
Mode A:
The sequence to boot up only the hypervisor processor is described in FIG. 16 .
Step 1:
1a: First, the Peripheral Status Maintainer (PSM) accesses BIOS.
1b: Next, the peripheral list and mapping table are updated based on system BIOS information.
1c: Then, the low-power hypervisor boots, initiates peripherals on internal bus, and starts peripheral interrupt service.
Step 2:
2a: First, PSM sends IRQ to low-power hypervisor processor.
2b: Next, low-power hypervisor processor starts peripheral maintenance services.
Step 3:
3a: Low-power hypervisor processor initiates all peripherals connected to the system.
Mode B:
The sequence that performance x86 processor boots up after hypervisor processor system is active is described in FIG. 17 .
Step 1:
1a: Low-power hypervisor sends power up signal to FSB Command Handler.
1b: FSB Command Handler sends reset instruction to performance x86.
Step 2:
2a: FSB Command Handler requests necessary system information from PSM (PSM presents itself as BIOS the x86 processor)
2b: FSB Command Handler provides necessary information to performance x86 processor during bootstrap of performance x86.
Step 3-1: Indirect Access
3-1a: Performance x86 sends FSB commands for indirect access.
3-1b: Low power hypervisor processor plays the role of a proxy, and executes high-speed x86 indirect access commands.
Step 3-2: Direct Access
3-2a: Performance x86 sends FSB commands for direct access.
3-2b: PSM monitors the direct access.
Mode C:
The sequence to boot up only the performance x86 processor is described in FIG. 18 . This can be a default mode of power up if the hetero computer system powers up the performance x86 only, can be implemented in pure hardware, without any firmware control.
Step 1:
1a: High-speed data switch resets mode to act as a bypass hybrid bridge sub system. (This is the default mode if the hetero powers up the performance x86, first, and only, can be implemented in pure hardware, without any firmware control.)
Step 2:
2a: Performance x86 boots up normally.
Mode D:
The sequence that hypervisor processor system boots up after the performance x86 system is active is described in FIG. 19 .
Step 1:
1a: PSM synchronizes information with BIOS.
1b: PSM updates peripheral list and mapping table.
Step 2:
2a: Low-power hypervisor boots up, initiates peripherals connected to internal bus, and initiates interrupt services.
Step 3:
3a: PSM sends IRQ to low-power hypervisor.
3b: Low-power hypervisor starts peripheral maintenance services.
Step 4:
4a: Low-power hypervisor notifies and requests the Bridge Logic to take over system services.
D: Super Operating System for the Heterogeneous Computer System
From the software perspective, an implementation of the heterogeneous computer system of the present invention runs the original version of both x86 (such as Windows or Linux) and ARM (such as Android) OS's over a heterogeneous hypervisor layer in its software system. Function of this heterogeneous hypervisor layer is to make coexistence of two active OS's on the hardware of the inventive computer system possible and further to allow for seamless communication between the two OS's for simultaneous applications of both worlds.
To achieve this, experimental versions of the hetero hypervisor layer software for the popular OS's to work on the x86-ARM hetero have been created and tested successfully. Presently versions of the layer covering Windows for x86 and Android for ARM have been tested. A revised version of these test heterogeneous hypervisor layer software, literally a super OS, can be running the ARM and x86 processors on the entire heterogeneous computer system hardware in parallel and cross-supports software applications of the two different OS's.
Thus, on a heterogeneous computer system of the present invention two different OS's can boot up and run simultaneously, each supporting its own applications. Applications of one OS can even be run within the other OS, and two applications of different OS can talk to each other directly and seamlessly.
FIG. 20 schematically illustrates this super OS for the heterogeneous computer system of the present invention. Such an inventive Super OS places conventional OS, such as Windows, Linux, Solaris, Android for smart mobile devices etc. under itself as “sub-OS's.” These conventional OS's need not be altered when operating under the Super OS. To these OS's, the heterogeneous computer system hardware that they each run on appears to be no different than the conventional x86 hardware they normally run. Once the Super OS boots up on the heterogeneous computer system, two different OS's can be alive on the same hardware simultaneously, supporting seamless multiple software applications of both OS at the same time and allows interchange of data in between.
For the construction of the Super OS, a heterogeneous hypervisor layer is created that is inserted between the OS and the hardware layers and spans across the two. With this software architecture of the inventive heterogeneous computer system technology, seamless cross-OS software application is possible. For example, a Windows Word can run directly within its Windows OS on the x86 hardware, or, the ARM processor can run Word via virtual computing across the heterogeneous hypervisor layer. To achieve this, full advantage of existing software technologies such as the open source virtual computing technology are taken.
FIGS. 21-24 respective illustrate the operating modes of the inventive heterogeneous computer system described in FIGS. 8-12 to support seamless cross-OS software application. Four modes the super OS of FIG. 20 boots and deploys itself include:
Mode A: Only the low-power hypervisor processor system is booted up active.
Mode B: Performance x86 processor boots up after hypervisor processor system is active.
Mode C: Only the performance x86 processor system is booted up active.
Mode D: Hypervisor processor system boots up after the performance x86 system is active.
The sequence to boot up only the hypervisor processor OS is described in FIG. 21 . This mode operates the software applications for the hypervisor processor only. The boot up procedure readies the inventive heterogeneous computer system so that software applications, for example, Android or Linux can be executed. The booting sequence involves:
1. Hypervisor processor (ARM) powers on.
2. Bridge initializes all peripherals connected directly to itself such as working RAM (to be distinguished from computer peripherals normally attached to the South Bridge of the x86 chipset.
3. Hypervisor processor (ARM) loads boot loader.
4. Boot loader loads Heterogeneous Hypervisor Layer Part-A.
5. Heterogeneous Hypervisor Layer Part-A loads OS 1 .
The sequence to boot up the performance x86 processor OS after the hypervisor processor OS is up is described in FIG. 22 . This mode operates the software applications for the hypervisor and performance x86 processor OS's. The boot up procedure readies the inventive heterogeneous computer system so that simultaneous and seamless cross-OS software applications are possible. The booting sequence involves:
1. Hypervisor processor powers on.
2. Bridge initiates all peripherals connected directly to itself.
3. Hypervisor processor loads boot loader.
4. Boot loader loads Heterogeneous Hypervisor Layer Part-A.
5. Heterogeneous Hypervisor Layer Part-A loads OS 1 .
6. Heterogeneous Hypervisor Layer Part-A powers on High-speed x86.
7. High-speed x86 loads Heterogeneous Hypervisor Layer Part-B.
8. Heterogeneous Hypervisor Layer Part-B loads OS 2 .
The sequence to boot up only the performance x86 processor OS is described in FIG. 23 . The booting sequence involves:
1. Performance x86 powers on.
2. Bridge acts as a bypass hybrid bridge sub-system.
3. Performance x86 loads BIOS, EFI or UEFI.
4. Performance x86 loads Heterogeneous Hypervisor Layer Part-B.
5. Heterogeneous Hypervisor Layer Part-B loads OS 2 .
The sequence to boot up the hypervisor processor OS after the performance x86 processor OS is up is described in FIG. 24 . This mode operates the software applications for the hypervisor and performance x86 processor OS's. The boot up procedure readies the inventive heterogeneous computer system so that simultaneous and seamless cross-OS software applications are possible. The booting sequence involves:
1. Performance x86 powers on.
2. Bridge acts as a bypass hybrid bridge sub-system.
3. Performance x86 loads BIOS or EFI or UEFI.
4. Performance x86 loads Heterogeneous Hypervisor Layer Part-B.
5. Heterogeneous Hypervisor Layer Part-B loads OS 2 .
6. Bridge (PSM) synchronizes with BIOS and initiates all peripherals connected to itself except x86 chipset.
7. Heterogeneous Hypervisor Layer Part-B powers on hypervisor processor.
8. Hypervisor processor loads boot loader.
9. Boot loader loads Heterogeneous Hypervisor Layer Part-A.
10. Hypervisor Layer part-A notifies Hypervisor Layer part-B to take over Hypervisor services.
11. Heterogeneous Hypervisor Layer part-A loads OS 1 .
12. OS 1 takes over system services.
While the above is a full description of the specific embodiments, various modifications, alternative constructions and equivalents may be used. For example, the invention has been described using examples with the hypervisor and the performance processor(s) on the same physical hardware of the inventive heterogeneous computer system. However, it is easily comprehensible that the processors can be physically separated at two or more locations such as when implemented in a cloud computing application. In such a scenario, parts and A and B respectively for the performance and hypervisor processors of the heterogeneous hypervisor software layer for the super OS can be linked via communications means—Internet in cloud computing. Therefore, the above description and illustrations should not be taken as limiting the scope of the present invention. | A super operating system for a heterogeneous computer system for executing tasks of software that has at least one performance processor, a processor supporting logic, and a hypervisor processor. The super operating system has a performance operating system for the performance processor; a hypervisor operating system for the hypervisor processor and a heterogeneous hypervisor software layer on top of the performance and hypervisor processors and below the performance and hypervisor operating systems. Under the super operating system, the hypervisor processor executes tasks that the hypervisor processor has sufficient processing power to handle and puts the performance processor to a power-conserving state. The hypervisor processor brings the performance processor out of power-conserving state to execute tasks that the hypervisor processor has insufficient processing power to handle. The performance and hypervisor processors simultaneously execute tasks that require combined processing power of all processors. | 8 |
This is a division, of application Ser. No. 630,489, filed Nov. 10, 1975 now U.S. Pat. No. 4,032,120.
BACKGROUND OF THE INVENTION
With the rapidly increasing growth of direct reduction of iron throughout the world, there is an increasing shortage of iron oxide feed material in pelletized form, commonly called oxide pellets. Increasingly, there is an economic need to utilize crushed and sized natural lump ore as the oxide feed material for direct reduction. Most of the suitable natural lump ores have a much higher sulfur content than oxide pellets. Generally, oxide pellets have a very low sulfur content inasmuch as most of the sulfur present in the natural ore or concentrate from which the pellets are made is burned out during the firing of the pellets under oxidizing conditions.
When ores containing sulfur are used as the oxide feed material for direct reduction, much of the contained sulfur is liberated from the ore during the reduction process. Such liberated sulfur is present in the spent reducing gas as hydrogen sulfide gas (H 2 S).
A highly efficient and commercially accepted direct reduction process is described in Beggs and Scarlett U.S. Pat. No. 3,748,120. In this process, spent reducing gas from a shaft type reduction furnace is mixed with hydrocarbon vapor and recycled through a catalytic reformer to produce fresh hot reducing gas. In the field of catalytic reforming of hydrocarbon vapor such as methane or natural gas, it is well known that the presence of H 2 S in the reformer has an adverse effect on reforming. The reforming catalyst is deactivated or poisoned by H 2 S, rendering the catalyst relatively ineffective. When an oxide feed material containing sulfur is used in the direct reduction process of U.S. Pat. No. 3,748,120, the H 2 S present in the spent reducing gas is recycled to the catalytic reformer with resultant loss in reforming efficiency.
In the direct reduction of iron oxide to metallic iron, it is well known that the oxide is progressively reduced from hematite (Fe 2 O 3 ) to magnetite (Fe 3 O 4 ) to wustite (FeO) to metallic iron (Fe). In conventional gaseous reduction wherein reducing gas contains H 2 and CO as reductants, and at conventional reduction temperatures in the range of about 1400° F to 1770° F (about 760° to 930° C), the reduction of hematite to magnetite to wustite occurs in about 30 to 45 minutes where oxide pellets or lump ore have a common particle size from about 1/4 inch to 1 inch. Metallic iron starts to form in the surface layer of the particle after this 30 to 45 minute period, and the complete reduction of the entire particle to metallic iron requires an additional 3 to 4 hours.
Extensive laboratory tests have been conducted in the direct reduction of sulfur-bearing iron oxide material using reducing gas having H 2 and CO as reductants, and under conditions which simulate commercial scale reduction conditions. It has been determined that sulfur is liberated from the feed material during the first 30 to 45 minutes of the reduction cycle, after which time no more sulfur is liberated. The liberated sulfur is in the form of H 2 S in the spent reducing gas and is readily measurable. When it was first observed that sulfur liberation ceases after the first 30 to 45 minutes of the reduction cycle, it was reasoned that metallic iron formed on the surface of the particles reacts with H 2 S to form an iron-sulfur compound, and the presence of the metallic iron prevents further liberation of sulfur from the particles. To substantiate this theory, a special reduction test was conducted using a weak reducing gas which was thermodynamically incapable of reducing wustite to metallic iron. In other words, in this special reduction test, the final stage of reduction was wustite with no formation of metallic iron. In this special reduction test, it was determined that sulfur was liberated as H 2 S continuously for a period of about 8 hours. In view of this observation, it is believed that the initial formation of metallic iron on the surface of the particles during normal direct reduction does, in fact, serve to prevent further sulfur liberation.
OBJECTS OF THE INVENTION
It is the principal object of my invention to provide an improved method for directly reducing particulate metal oxide material to a metallized product in a shaft furnace in which spent top gas is withdrawn in two streams, one stream being free of sulfur, the second stream being sulfur rich.
It is also an object of my invention to provide a highly efficient process for the direct reduction of sulfur-bearing iron oxide or iron ore in which a portion of the spent reducing gas is sulfur free and suitable for catalytic reformer feed gas.
It is another object of my invention to provide a method of avoiding sulfur poisoning of the catalyst in a catalytic reformer when spent reducing gas from a direct reduction furnace is recycled through the catalytic reformer to provide fresh reducing gas.
BRIEF SUMMARY OF THE INVENTION
The aforesaid objects of this invention and other objects which will become apparent as the description proceeds are achieved by providing means for establishing an upper pre-reducing, or sulfur removal, zone in a direct reduction shaft furnace, removing a first portion of reacted or spent reducing gas from the reduction zone of the furnace prior to its reaching the sulfur removal zone, this first portion being substantially sulfur free, and subsequently removing the remaining, sulfur rich portion of spent top gas in a separate removal system for handling this sulfur-containing gas.
Suitable apparatus comprises a multiplicity of reacted gas takeoff pipes extending into the reducing zone of the furnace beneath the sulfur removal zone.
BRIEF DESCRIPTION OF THE DRAWINGS
For a better understanding of this invention, reference should be made to the accompanying drawings wherein:
FIG. 1 is a schematic drawing of a vertical shaft furnace with its associated equipment showing one method of practicing the invention.
FIG. 2 is a schematic drawing of a vertical shaft furnace showing alternative means for practicing the invention.
FIG. 3 is a sectional plan view taken along line III--III of FIG. 1.
FIG. 4 is a sectional plan view taken along the line IV--IV of FIG. 2.
DETAILED DESCRIPTION
Referring now to FIG. 1, vertical shaft furnace 10 has a feed hopper 12 mounted at the top thereof into which iron oxide pellets 14 or other particulate feed materials such as lump ore are charged. The pellets descend by gravity through one or more feed pipes 16 to form a bed 18 of particulate iron oxide containing material or burden in the shaft furnace. The upper portion of shaft furnace 10 comprises a pre-reducing sulfur removal zone A1, the central portion of the shaft furnace comprises a reducing zone B1, while the lower portion of the furnace comprises a cooling zone C1. A pellet discharge pipe 20 is located at the bottom of shaft furnace 10. Reduced iron material 22 is removed from the furnace by discharge conveyor 24 located beneath discharge pipe 20. Removal of the metallized pellets via discharge pipe 20 establishes a gravitational flow of the particulate iron oxide burden through shaft furnace 10.
At the central portion of the shaft furnace 10 is a bustle and tuyere system, indicated generally at 26, having gas ports 28 through which hot reducing gas is introduced to flow upwardly in counterflow relationship to the movement of the burden 18. The spent top gas exits the furnace through two separate spent gas offtake systems. Downwardly protruding takeoff pipes 30 communicate with upper plenum 32. The spent top gas from plenum 32 exits the furnace through gas outlet 34. The lower end of each pellet feed pipe 16 extends sufficiently far into the furnace to create a reacted gas disengaging plenum 36, which permits the remaining spent reducing gas to exit generally symmetrically from the pellet stock line 38 and flow freely to reacted gas outlet 40.
A loop recirculating system is provided at the cooling zone of the furnace to cool the pellets prior to their discharge. This system includes a cooler scrubber 42, a recirculating gas blower 44, gas inlet 46, gas distributing member 48 located within furnace 10, gas collecting member 50 positioned above gas distributing member 48 within the furnace, gas outlet 52, and gas circulation pipes 54.
A reformer furnace 60 having a fuel fired burner 62, a flue pipe 64 and a plurality of indirect heat exchanger catalyst tubes 66, which are externally heated by burner 62, only one tube being shown, generates hot reducing gas. The reducing gas flows from the catalyst tubes 66 to the bustle and tuyere system 26 through gas pipe 68.
The substantially sulfur free spent top gas leaving shaft furnace 10 through the gas outlet 34 flows through pipe 70 to a scrubber-cooler 72 wherein the gas is cooled and the dust particles are removed. Pipe 74 leads from scrubber-cooler 72 to a gas blower 76 which is required to circulate the top gas from the scrubber-cooler through pipes 74 and 78. Pipe 78 transmits the spent top gas to the catalyst tubes 66 of the reformer furnace to reform the spent gas into an effective reducing gas by stoichiometric reforming. A source 80 of a gaseous hydrocarbon such as natural gas, is available to enrich the spent top gas in pipe 78 if desired.
Sulfur rich spent top gas leaving the shaft furnace through gas outlet 40 flows to a scrubber-cooler 82 wherein the gas is cooled and the dust particles are removed. Pipe 84 transmits the cleaned and cooled top gas to a burner 62 of the reformer furnace as fuel to be used as a source of heat. A source 86 of a gaseous hydrocarbon such as natural gas delivers make-up gas to burner 62 through pipe 84 when required. Combustion air for the burner 62 in the reforming furnace is supplied from source 88. Valve 90 in pipe 84 opens or closes in response to back pressure controller 92 thus maintaining a constant flow of gas to burner 62 relating to the expansion of gas reformed in the reformer. If the amount of gas resulting from expansion in the reformer tubes is not sufficient to provide the required heat for the reformer, a valve 90 opens to admit natural gas from source 86 to burner 62 as fuel.
An alternative embodiment shown in FIG. 2 includes provision for utilizing a portion of the spent top gas as cooling gas, and for allowing a porion of the cooling gas to flow upwardly from the cooling zone into the reducing zone, become heated by the hot burden and act as reductant in the reducing zone. The furnace of FIG. 2 has four distinct zones. Zone A2 in the uppermost portion of the furnace is a sulfur removal and pre-reduction zone. Zone B2 is the reducing zone. Zone C2 is an upflow gas preheat zone, while zone D2 is the cooling zone.
In the alternative embodiment of FIG. 2, a number of downwardly extending spent gas takeoff tubes 100 extend through the top of shaft furnace 10 and into the burden 18. Spent top gas from the single interior plenum 102 in the top of the sulfur removal zone exits the furnace through spent top gas outlet 104 and is cleaned and cooled in scrubber-cooler 82. A portion of the sulfur-containing top gas flows to the burner through pipe 106. A second portion of the sulfur-containing top gas is admitted to the cooling gas recirculating circuit through pipe 108. A hydrocarbon-containing gas such as natural gas or methane can be added to this spent top gas from source 110 to enrich the cooling gas. The recirculating cooling gas circuit is similar to that of FIG. 1 except for the addition of spent gas inlet 112. When gas is added to the cooling gas circuit, a like volume of upflow gas 114 which is forced out of the circuit into the furnace flows upwardly through the upflow gas preheat zone C2 wherein it is heated by the descending hot burden and a portion of the CO 2 and H 2 O contained therein is reformed to CO and H 2 rendering the upflow gas once more an effective reductant.
In the emodiment of FIG. 2, the reductant rich top gas from pipes 100 can be gathered in a plenum not shown before being introduced to cooler-scrubber 82, or each pipe 100 can communicate directly with the cooler-scrubber.
In the operation of the embodiment of FIG. 1, a shaft type reduction furnace has a pre-reduction zone A1, a reduction zone B1 and a cooling zone C1. Fresh hot reducing gas containing H 2 and CO as reductants is generated in a catalytic reformer 60 and introduced to the reduction furnace through ports 28 at the lower region of reduction zone B1. The reducing gas flows upwardly through the furnace burden 18. In the upper region of the reduction zone B1, a portion of the gas is removed from the furnace through pipes 30 as a "reduction-rich" partially spent top gas. The remaining portion of the gas flows upwardly through the pre-reduction zone A1 and exits the burden stockline 38 as a relatively "reductant-lean" fully spent top gas.
In the pre-reduction zone A1, which preferably is sized for a burden retention time of 1 to 11/2 hours, the incoming particulate oxide feed material is pre-reduced partially to metallic iron. Sulfur, which is liberated from the iron oxide feed material, is confined to the pre-reduction zone, and the H 2 S, which is liberated, is confined to the reductant-lean top gas.
The reductant-rich top gas which is removed from the burden through the immersed pipes 30 is free of sulfur. The reductant-rich top gas, containing CO 2 and H 2 O vapor formed in the reduction zone, is cooled, scrubbed of dust and admitted to a catalytic reformer 60. Natural gas or other hydrocarbon vapor is added to the cooled reductant-rich top gas and is reformed by CO 2 and residual H 2 O vapor present in this cooled top gas to form fresh hot reducing gas.
The reductant-lean, sulfur-containing top gas is cooled and scrubbed of dust, then utilized as fuel to fire the reformer furnace. The reductant-lean top gas will ordinarily contain about 100 to 400 parts per million by volume of H 2 S with a typical high sulfur lump ore as the oxide feed material. Although this H 2 S level is not acceptable for catalytic reforming, it is a very acceptable level in a fuel gas to be burned.
In the embodiment of FIG. 2, the reductant-rich, sulfur-free top gas is removed from the burden in a region near the wall of the reduction furnace (See FIG. 4), cooled and scrubbed of dust and admitted to a catalytic reformer as heretofore described. The sulfur-laden, reductant-lean top gas is removed at the burden stockline, is cooled and scrubbed of dust. A portion of this gas is used as fuel to fire the reformer furnace. A second portion is admitted to the cooling zone recirculating circuit, and then flows upward from the cooling zone D2 through an upflow gas preheat zone C2 from which the gas converges and flows upward through the center of the reduction zone B2 and pre-reduction zones A2. Natural gas or other hydrocarbon vapor from source 110 is mixed with the reductant-lean top gas which is admitted to the cooling zone circuit, in order to enable some reforming to be achieved in the upflow gas preheat zone C2 to enhance the reducing potential of the upflow gas.
The reductant-rich top gas is removed from the burden 18 through the immersed pipes 100, which are near the wall of the furnace. The location of pipes 100 insures that none of the reductant-lean top gas flowing upwardly from cooling zone D2 and converging to the center of the furnace is commingled with the reductant-rich top gas.
The H 2 S in the reductant-lean top gas admitted to the cooling zone D2 is removed from the gas in zone D2 by reaction with the cooled sponge iron. The upflow gas is essentially free of sulfur so that the hot sponge iron burden in the upflow gas preheat zone is an effective reforming catalyst.
It will be understood that the reductant-lean top gas may be used for purposes other than specifically described, such as fuel gas for use external of the direct reduction equipment shown in the drawings.
It can readily be seen from the foregoing that many other alternative embodiments of the invention are possible. Thus, while in accordance with the patent statutes, preferred an alternative embodiments of the invention have been illustrated and described in detail, it is to be particularly understood that the invention is not limited thereto or thereby. | A method for direct reduction of iron ore containing sulfur in a shaft type reduction furnace wherein two separate streams of spent reducing gas are withdrawn from the reduction furnace. One stream, being substantially free of sulfur, is recycled through a catalytic reformer to produce fresh reducing gas, the other stream, containing sulfur, is utilized in the process where sulfur is not of consequence. | 2 |
CROSS-REFERENCES TO RELATED APPLICATIONS
[0001] This application claims the benefit of U.S. Provisional Application No. 62/160,422, filed May 12, 2015, which is incorporated herein by reference in its entirety.
FIELD OF THE INVENTION
[0002] The present invention is generally directed toward an improved latching device that secures the enclosure door on pad-mounted transformers or other similar equipment.
BACKGROUND OF THE INVENTION
[0003] Latching devices for the enclosure door on pad-mounted transformers and other similar equipment (collectively referred to herein as “transformers”) having a handle and locking and latching mechanisms are well known in the art. Typically, the handle as well as the locking and latching mechanisms of the latching device are located near the bottom of the transformer, close to the ground. There are often long periods in which the enclosure door is not opened, and dirt, snow, road salts, sand, insects, grass, rocks and other debris or vegetation may pile up, grow or accumulate around the handle and locking and latching mechanisms. Additionally, the closer to the ground these components are located, the more exposed they are to moisture and other corrosive agents. When access is eventually required, sometimes under emergency situations, accessibility and/or the functionality of the device may be compromised. Debris or vegetation may have to be removed or dug away to gain access and the device may not operate or disengage properly due to corrosion. In addition, the lower the handle, the more bending is required for the operator to get into a position to disengage the locking mechanisms and use the handle to open the enclosure door. More specifically, operators are required to bend their backs while keeping their knees straight when opening the latching device, thus putting increased stress on the intervertebral discs in their lumbar region and increasing their risk of sciatica.
[0004] The Institute of Electrical and Electronics Engineers (“IEEE”) standards require the enclosure door on a transformer to be secured with a pad lock and a security bolt which engages a threaded receptacle, whereby the enclosure door can only be unlatched and opened after the pad lock has been removed and the security bolt unscrewed and disengaged. On the traditionally designed latching device, the security bolt is attached to the enclosure door, while the threaded receptacle is mounted on the bottom sill of the transformer. The nature of this interface between the enclosure door and sill makes it susceptible to the development of alignment issues which can sometimes prevent the security bolt from properly engaging the threaded receptacle. For example, as disclosed in U.S. Pat. No. 6,066,802, the bolt provided for locking the outer hood of the transformer is carried by a latch plate fixed to the outer hood and is adapted to be inserted in a nut carried by the bottom sill of the transformer. The aforementioned patent (U.S. Pat. No. 6,066,802) is hereby incorporated by reference.
[0005] With the traditional design of the latching device, it is possible for a unit to appear as though it is completely closed, secured and locked yet not be, thus creating security and safety issues. For example, if the security bolt is depressed and the pad lock is looped through the recess cup and locked and then the door is moved or rotated to a closed or nearly closed position, the unit could mistakenly appear to be completely closed, secured and locked, but actually be accessible by simply raising the door. In addition, because of their proximity to the ground, the locking mechanisms on the traditional designs may not be easily viewable to a utility crew during drive-by safety inspections, especially if vegetation is overgrown or if debris has piled up or accumulated near the base of the transformer.
[0006] Some inventors have attempted to address, at least in part, one or more of the above-described problems with the traditionally designed latching device. For instance, U.S. Pat. No. 5,739,464 discloses a latching device design wherein a detachable enclosure cover is secured to the transformer via a curved latch arm mounted to the front tank panel and extending through the air or cable compartment to an opening in the front top center of the detachable cover. It is claimed that the locking structure at the juncture of the arm and the cover, in conjunction with tongue and groove structure on the tank panel and the enclosure, tightly secures the cover so that tamper resistance is improved. However, because the enclosure is a detachable cover which must be lifted and removed completely, as opposed to a rotating hinged door which remains attached to the transformer, this invention is only feasible if the cover is constructed of lightweight material, such as fiber or plastic, but steel is the traditional, and in fact preferred, material for almost all electrical utility applications. As such, this invention is not a practical solution for most of the industry because the weight of a detachable cover made of steel would make it unmanageable and unsafe. Also, the latch arm extending through the air or cable compartment can get in the way of cables. The aforementioned patent (U.S. Pat. No. 5,739,464) is hereby incorporated by reference.
SUMMARY OF THE INVENTION
[0007] We disclose herein an improved latching device, including the handle and locking and latching mechanisms thereof, for securing the enclosure door, including rotating hinged-type enclosure doors, on pad-mounted transformers or other similar equipment, comprised mainly of a raised handle and locking mechanisms, a latch linkage and a handle release lever. The device improves accessibility, functionality, stability, security and safety related issues as compared to traditional designs.
BRIEF DESCRIPTION OF THE DRAWINGS
[0008] Further advantages of the invention will become apparent by reference to the detailed description of preferred embodiments when considered in conjunction with the drawings:
[0009] FIG. 1 is a perspective view of a pad-mounted transformer with the enclosure door in the closed position and the improved latching device in an unlatched position.
[0010] FIG. 2 is a perspective view of the enclosure door in the closed position and the improved latching device in an unlatched position.
[0011] FIG. 3 is a perspective view of the enclosure door in the closed position and the improved latching device in an unlatched position.
[0012] FIG. 4 is a perspective view of the enclosure door in the closed position and the improved latching device in an unlatched position.
[0013] FIG. 5 is a side elevational view of the enclosure door in the closed position, the improved latching device in an unlatched position, and the handle release lever in the released position.
[0014] FIG. 6 is a rear elevational view of the enclosure door in the closed position and the improved latching device in an unlatched position.
[0015] FIG. 7 is a perspective view of the enclosure door in the closed position and the improved latching device in an unlatched position.
[0016] FIG. 8 is a side elevational view of the enclosure door in the open position, the improved latching device in an unlatched position, and the release lever in the restraining position.
[0017] FIG. 9 is a perspective view of the enclosure door in the open position, the improved latching device in an unlatched position, and the release lever in the restraining position.
[0018] FIG. 10 is a perspective view of the enclosure door in the closed position, the improved latching device in a latched position, and the release lever in the released position.
[0019] FIG. 11 is a side elevational view of the enclosure door in the closed position, the improved latching device in a latched position, and the release lever in the released position.
[0020] FIG. 12 is a perspective view of the enclosure door in the closed position, the improved latching device in a latched position, and the release lever in the released position.
[0021] FIG. 13 is a perspective view of the locking and latching mechanisms of the improved latching device in a latched and locked position.
DETAILED DESCRIPTION
[0022] The following detailed description is presented to enable any person skilled in the art to make and use the device. For purposes of explanation, specific details are set forth to provide a thorough understanding of the present invention. However, it will be apparent to one skilled in the art that these specific details are not required to practice the invention. Descriptions of specific applications are provided only as representative examples. Various modifications to the preferred embodiments will be readily apparent to one skilled in the art, and the general principles defined herein may be applied to other embodiments and applications without departing from the scope of the device. The present device is not intended to be limited to the embodiments shown or described, but is to be accorded the widest possible scope consistent with the principles and features disclosed herein.
[0023] Our device pictured in the drawings and described below improves the latching device by raising the handle and locking mechanisms up, away from the ground and interface between the enclosure door and the sill. This reduces the likelihood of accessibility and functionality problems associated with debris, vegetation and corrosion, and makes the device easier to view by utility crews during drive-by safety inspections. Additionally, our device improves the ergonomics of the opening process by reducing the amount of bending necessary to obtain a position needed to unlock and remove the pad lock 18 , disengage the security bolt 17 and start the lifting process.
[0024] The drawings illustrate a preferred embodiment of the improved latching device with raised handle 3 and locking mechanisms on a pad-mounted transformer 20 , as shown in FIG. 1 , with a rotating hinged enclosure door 2 . The rotating hinged enclosure door 2 is connected to the tank 1 of the pad-mounted transformer 20 via hinges 11 so that the rotating enclosure door 2 opens up and away from the tank 1 when lifted up by an operator.
[0025] FIGS. 2-7 depict the preferred embodiment of the pad-mounted transformer 20 with the rotating hinged enclosure door 2 closed and the improved latching device in an unlatched position (raised handle 3 pulled out).
[0026] The locking mechanism of the improved latching device is comprised primarily of a raised handle 3 , raised locking mechanisms comprised of a recess cup 4 for the security bolt 17 and pad lock 18 , and a threaded receptacle 12 which receives the security bolt 17 , and a lock hasp 15 . When the rotating hinged enclosure door 2 is closed and latched, the pad lock 18 is looped through the lock hasp 15 and recess cup 4 , and covers the head of the security bolt 17 .
[0027] To open the rotating hinged enclosure door 2 , the operator would remove the pad lock 18 , use a socket wrench or other tool to unscrew the security bolt 17 and disengage it from the threated receptacle 12 allowing the raised handle 3 to be lifted up (pulled out) so that the recess cup 4 will no longer be aligned with the lock hasp 15 as will be appreciated from FIG. 4 depicting the device in the unlatched position. Pulling the raised handle 3 out causes the latch loop 8 to move down, allowing the rotating hinged enclosure door 2 to be opened.
[0028] The preferred embodiment of our device includes a toggle action to the mechanics of the latching device. This toggle action allows significant forgiveness and tolerances with respect to potential alignment issues when the enclosure door is latched and secured, resulting in improved security, functionality and tamper resistance. The toggle action also adds an element of leverage which makes it easier to unlatch (and latch) the rotating hinged enclosure door 2 in the event of obstruction or corrosion. Our design largely eliminates problems with alignment of the locking components by positioning the security bolt 17 , the threaded receptacle 12 , the lock hasp 15 , and the pad lock 18 features all on the rotating hinged enclosure door 2 and in close proximity to each other as compared to traditional designs where the security bolt is attached to the enclosure door, while the threaded receptacle is mounted on the bottom sill of the transformer. In addition, our design improves safety by making it less likely an enclosure door could mistakenly appear to be completely closed, secured and locked when it is not.
[0029] The raised handle 3 and the recess cup 4 on the handle are located on the external surface of the front panel of the rotating hinged enclosure door 2 and, together, hold the security bolt 17 captive. As shown in FIG. 5 , the threaded receptacle 12 is mounted directly adjacent thereto on the internal surface of the front panel of the rotating hinged enclosure door 2 .
[0030] The latching mechanisms, including the handle release lever 6 , a latch loop 8 and a latch pin 9 , are located further below, at the interface between the enclosure door 2 and sill 7 attached to the frame 19 . The frame 19 is located on the inside of the rotating hinged enclosure door 2 and includes cross bracing. Because the handle and locking mechanisms are located at a distance further above the sill 7 , as compared to traditionally designed latching devices, they are more easily accessible by the operator and the likelihood of accessibility and functionality issues from obstruction and/or corrosion is lessened. Because the recess cup 4 , security bolt 17 , threaded receptacle 12 , and lock hasp 15 are all mounted on the enclosure door 2 , alignment issues with respect to these locking mechanisms are minimized.
[0031] A potential embodiment of the invention includes placement of the latch loop 8 on the inside of the frame 19 . This design reduces the number of parts necessary for the device to function, while making the structure of the device stronger.
[0032] In the preferred embodiment of the invention, the raised handle 3 cannot be moved into a latched position (pushed in) unless the rotating hinged enclosure door 2 is fully closed.
[0033] As shown in FIGS. 2-7 , when the enclosure door 2 is unlatched by pulling the raised handle 3 out into the unlatched (open) position, the latch loop 8 moves down and disengages the latch pin 9 by centering the latch pin 9 in the opening of the latch loop 8 , without contact. From this position, the rotating hinged enclosure door 2 is free to be opened, in this case by rotating it up on the hinges 11 .
[0034] In a potential embodiment of the invention, the latch loop 8 is capable of moving away from the latch pin 9 , thus providing an additional degree of motion.
[0035] As seen in FIGS. 8 and 9 , when the enclosure door is pulled away from the sill 7 in the preferred embodiment of the invention, the raised handle 3 will remain in the unlatched (pulled out) position and cannot be pushed back into the latched position because the release lever pin 13 mounted on the spring-powered handle release lever 6 is engaged with and restraining the latch loop 8 . The raised handle 3 can only be released from this position (pushed back in) when, upon the enclosure door 2 being completely closed, the handle release lever 6 is pushed back against the release lever spring 14 by the latch pin 9 and the release lever pin 13 is disengaged from the latch loop 8 as can be appreciated from FIGS. 10-12 depicting the device in the latched position. As such, even if a pad lock 18 was affixed to the recess cup 4 and the rotating hinged enclosure door 2 was then lowered to a closed or nearly closed position, the raised handle 3 on our design, as compared to traditional designs, could still not be pushed completely into a flush or latched position and thus the rotating hinged enclosure door 2 could not as easily be mistaken as closed, secured and locked, when it was not. Additionally, even if the release lever 6 was intentionally defeated to release the raised handle 3 while the rotating hinged enclosure door 2 was in the open position, with the security bolt 17 fully threaded into the receptacle 12 and a pad lock 18 affixed to the recess cup 4 through the lock hasp 15 , the rotating hinged enclosure door 2 cannot be fully closed into a flush position because latch loop 8 would contact the front of latch pin 9 and, thus, the rotating hinged enclosure door 2 could not as easily be mistaken as closed, secured and locked, when it was not.
[0036] As shown in FIGS. 5 , when the enclosure door 2 is fully closed, the handle release lever 6 is depressed which disengages the release lever pin 13 from the latch loop 8 . This position allows the raised handle 3 to be pushed in, which operates the latch linkage 5 on the inside of the front panel of the enclosure door 2 , which is connected to a connection link 10 , which in turn raises the latch loop 8 to engage the latch pin 9 , as shown in FIG. 11 . Engaging said latch pin 9 pulls the enclosure door 2 down hard on the sill 7 allowing the lock hasp 15 to pass through the hasp slot 16 so that the security bolt 17 can be engaged and the pad lock can be attached to the pad mounted transformer 20 .
[0037] The toggle action of the latch loop 8 allows forgiveness and tolerances at the interface between the enclosure door 2 and sill 7 which ensures that when the enclosure door 2 is closed and the raised handle 3 is pushed in, the various components are in a position to properly latch and tightly secure the enclosure door 2 to the sill 7 . This improves the functionality and tamper resistance of the unit. The toggle action also provides leverage when unlatching (or latching) the device in the event of obstruction or corrosion.
[0038] The preferred embodiment of the device is composed of steel manufactured using steel metal stamping where laser, plasma or water jet generated blanks are folded on stamping press dies. This preferred method of manufacture can be utilized to create fewer parts of different shapes and sizes necessary to accomplish the improved function of the latching device, all of which are contemplated by this device.
[0039] Alternate methods of manufacture of the device including casting, molding, formed wire parts or machining of parts and include alternate materials, such as plastic.
[0040] The latching mechanisms can be assembled by the use of rivets, caps, screws and nuts, fasteners, pins, other fastening mechanisms or welding.
[0041] The advantages of the device have been shown in ergonomic evaluations. The results of the evaluation showed that the improved latching device provides a clear ergonomic and postural change deviation that allows the operator to effectively choose the method of lifting and diminishes the risk of substantial harm to the lumbar spine. Further, the operators presented with the ability to decrease the amount of time required to perform the essential task when utilizing the improved latching device. Additionally, due to device being located at a distance above the sill 7 , debris around the pad-mounted transformer 20 would not substantially restrict the ability to ambulate the handle during lifting.
[0042] It should be appreciated that different arrangements of the basic parts are possible to achieve the same function. Additionally, material gages of parts could be changed. Some parts could be further combined into a single part to provide multiple functions.
[0043] The terms “comprising,” “including,” and “having,” as used in the claims and specification herein, shall be considered as indicating an open group that may include other elements not specified. The terms “a,” “an,” and the singular forms of words shall be taken to include the plural form of the same words, such that the terms mean that one or more of something is provided. The term “one” or “single” may be used to indicate that one and only one of something is intended. Similarly, other specific integer values, such as “two,” may be used when a specific number of things is intended. The terms “preferably,” “preferred,” “prefer,” “optionally,” “may,” and similar terms are used to indicate that an item, condition or step being referred to is an optional (not required) feature of the invention.
[0044] The invention has been described with reference to various specific and preferred embodiments and techniques. However, it should be understood that many variations and modifications may be made while remaining within the spirit and scope of the invention. It will be apparent to one of ordinary skill in the art that methods, devices, device elements, materials, procedures and techniques other than those specifically described herein can be applied to the practice of the invention as broadly disclosed herein without resort to undue experimentation. All art-known functional equivalents of methods, devices, device elements, materials, procedures and techniques described herein are intended to be encompassed by this invention. Whenever a range is disclosed, all subranges and individual values are intended to be encompassed. This invention is not to be limited by the embodiments disclosed, including any shown in the drawings or exemplified in the specification, which are given by way of example and not of limitation.
[0045] While the invention has been described with respect to a limited number of embodiments, those skilled in the art, having benefit of this disclosure, will appreciate that other embodiments can be devised which do not depart from the scope of the invention as disclosed herein. Accordingly, the scope of the invention should be limited only by the attached claims.
[0046] All references throughout this application, for example patent documents including issued or granted patents or equivalents, patent application publications, and non-patent literature documents or other source material, are hereby incorporated by reference herein in their entireties, as though individually incorporated by reference, to the extent each reference is at least partially not inconsistent with the disclosure in the present application (for example, a reference that is partially inconsistent is incorporated by reference except for the partially inconsistent portion of the reference). | An improved latching device that secures a lift-style hood is described with inherent properties for providing increased accessibility, functionality, stability, security and safety as compared to traditional designs. | 4 |
BACKGROUND
[0001] Blowout preventers (BOPs) are used in hydrocarbon drilling and production operations as a safety device that closes, isolates, and seals the wellbore. Blowout preventers are essentially large valves connected to the wellhead and comprise closure members that seal and close the well to prevent the release of high-pressure gas or liquids from the well. One type of blowout preventer used extensively in both low and high-pressure applications is a ram-type blowout preventer. A ram-type blowout preventer uses two opposed closure members, or rams, disposed within a specially designed housing, or body. The blowout preventer body has a bore aligned with the wellbore. Opposed cavities intersect the bore and support the rams as they move into and out of the bore. A bonnet is connected to the body on the outer end of each cavity and supports an operator system that provides the force required to move the rams into and out of the bore.
[0002] Ram-type blowout preventers are often operated using pressurized hydraulic fluid to control the position of the closure members relative to the bore. The flow of hydraulic fluid to the rams is controlled via one or more control pods of the blowout preventer control system. The control pod provides an electrical interface for operation of the blowout preventer from a drilling platform or other surface location. The control pod may be modularized to facilitate pod testing and service by allowing individual replacement and/or testing of each module. The control pod generally includes an electronics package (MUX module) and a hydraulics module (MOD module). The MUX module provides electrical communication with surface systems and electrically activated solenoid valves. The solenoid valves control flow of hydraulic fluid to hydraulic valves of the MOD module.
SUMMARY
[0003] An apparatus and method for monitoring valve operation are disclosed herein. In one embodiment, an apparatus for monitoring valve operation includes a first acoustic sensor and a monitoring system. The first acoustic sensor is to couple to a valve to detect vibration of the valve. The monitoring system is communicatively coupled to the first acoustic sensor. The monitoring system is configured to receive a signal generated by the first acoustic sensor. The signal is representative of vibration of the valve and the components therein. The monitoring system is also configured to identify leakage in the valve based on the signal.
[0004] In another embodiment, a well control system includes a blowout preventer, a hydraulics module, and a monitoring system. The hydraulics module includes a first valve and a first acoustic sensor. The first valve is configured to provide hydraulic pressure to the blow out preventer. The first acoustic sensor is coupled to the first valve to detect vibration of the first valve. The monitoring system is communicatively coupled to the first acoustic sensor. The monitoring system is configured to receive a first signal generated by the first acoustic sensor. The first signal is representative of vibration of the first valve. The monitoring system is also configured to identify a condition of the first valve based on the signal.
[0005] In a further embodiment, a fluid control assembly includes a first valve, a second valve, a first acoustic sensor, a second acoustic sensor, a third acoustic sensor, and a monitoring system. The first valve and the second valve are to control flow of fluid. The first acoustic sensor is coupled to the first valve to detect vibration of the first valve. The second acoustic sensor is coupled to the second valve to detect vibration of the second valve. The third acoustic sensor is to detect ambient vibration. The monitoring system is communicatively coupled to the first, second, and third acoustic sensors. The monitoring system is configured to receive signals generated by the first and second acoustic sensors that are representative of vibration of the first and second valves, and to receive signals generated by the third acoustic sensor that are representative of ambient vibration. The monitoring system is also configured to identify a condition of each of the first and second valves based on the signals.
BRIEF DESCRIPTION OF THE DRAWINGS
[0006] For a detailed description of exemplary embodiments of the invention, reference will now be made to the accompanying drawings in which:
[0007] FIG. 1 shows a drilling system including a blowout preventer in accordance with various embodiments;
[0008] FIG. 2 shows a block diagram of a valve monitoring system in accordance with various embodiments;
[0009] FIG. 3 shows a cross-section of a valve with associated acoustic sensor in accordance with various embodiments;
[0010] FIG. 4 shows an example of an acoustic energy plot generated by a leaking valve in accordance with various embodiments;
[0011] FIG. 5 shows a block diagram of a valve monitoring system in accordance with various embodiments; and
[0012] FIG. 6 shows a block diagram of a valve monitoring system in accordance with various embodiments;
[0013] FIG. 7 shows a block diagram of an acoustic sensor assembly that includes a plurality of acoustic sensing channels in accordance with various embodiments;
[0014] FIG. 8 shows a diagram of an acoustic sensor assembly that includes a plurality of acoustic sensing channels in accordance with various embodiments;
[0015] FIG. 9 shows a block diagram of a valve monitoring system in accordance with various embodiments; and
[0016] FIG. 10 shows a block diagram of a valve monitor in accordance with various embodiments.
NOTATION AND NOMENCLATURE
[0017] Certain terms are used throughout the following description and claims to refer to particular system components. As one skilled in the art will appreciate, companies may refer to a component by different names. This document does not intend to distinguish between components that differ in name but not function. In the following discussion and in the claims, the terms “including” and “comprising” are used in an open-ended fashion, and thus should be interpreted to mean “including, but not limited to . . . .” Also, the term “couple” or “couples” is intended to mean either an indirect or direct connection. Thus, if a first device couples to a second device, that connection may be through a direct connection, or through an indirect connection via other devices and connections. The recitation “based on” is intended to mean “based at least in part on.” Therefore, if X is based on Y, X may be based on Y and any number of other factors.
DETAILED DESCRIPTION
[0018] The following discussion is directed to various embodiments of the invention. Although one or more of these embodiments may be preferred, the embodiments disclosed should not be interpreted, or otherwise used, as limiting the scope of the disclosure, including the claims. In addition, one skilled in the art will understand that the following description has broad application, and the discussion of any embodiment is meant only to be exemplary of that embodiment, and not intended to intimate that the scope of the disclosure, including the claims, is limited to that embodiment.
[0019] Like all mechanical components, the hydraulic valves used to actuate a blowout preventer (BOP) are subject to wear. Unfortunately, using conventional methods the condition of a valve may be difficult to determine until the valve exhibits symptoms clearly indicative of malfunction. Valve malfunction may result in the BOP, or a substantial portion thereof, being removed from service to facilitate valve replacement. Removing a BOP from service can be costly and time consuming.
[0020] Embodiments of the present disclosure include a monitoring system that characterizes valve operation. The monitoring system includes acoustic sensors coupled to the valves. The acoustic sensors acquire signals that are indicative of the state and condition of the valve. The monitoring system processes the signals to characterize the valve. Processing and analysis of the acoustic signals emitted by the valve allow the monitoring system to identify leaks in the valve that may undetectable using conventional methods and to identify degradation of valve components. As a result, embodiments can reduce the expense of BOP maintenance by allowing for replacement or repair of valves via routine maintenance operations rather than unscheduled removal of the BOP stack from service.
[0021] FIG. 1 shows a drilling system 150 in accordance with various embodiments. The drilling system 150 includes a drilling platform and drilling rig 152 , a riser 154 , and a BOP 156 . The BOP 156 is coupled to a wellhead 158 . The riser 154 connects the BOP 156 to the drilling platform 152 . One or more control pods 100 are coupled to the BOP 156 for actuating BOP hydraulics in response to control signals provided from the surface. The control pods 100 include valves that control the flow of hydraulic fluid to the BOP 156 . Failure of one of the valves can cause the BOP 156 to be removed from service for unscheduled replacement of the valve.
[0022] The drilling system 150 includes a valve monitoring system that characterizes the hydraulic valves of the BOP control pod 100 based on vibration generated by the valves. While FIG. 1 illustrates a marine drilling system 150 , and embodiments of the present disclosure may be described with respect to the marine drilling system 150 , embodiments are also applicable to monitoring valves in a land or surface drilling environment, and to various other applications in which monitoring of valve condition may be beneficial.
[0023] FIG. 2 shows a block diagram of a valve monitoring system 200 suitable for use in the drilling system 150 . The valve monitoring system 200 includes a valve 202 , an acoustic sensor 204 , and a valve monitor 206 . The valve 202 is a valve of the BOP control pod 100 . The valve 202 may be any type of valve suitable for controlling the flow of hydraulic fluid to the BOP 156 . For example, the hydraulic valve 202 may be a ball valve, a needle valve, a gate valve, a butterfly valve, a shuttle valve, or any other type of valve suitable for controlling fluid flow.
[0024] The acoustic sensor 204 is coupled to the valve 202 . In some embodiments, the acoustic sensor 204 may be attached to an exterior surface of the valve 202 . For example, the acoustic sensor 204 may be mechanically affixed to an exterior surface of a housing of the valve 202 by a bolt, an adhesive, a magnet, or other suitable attachment method. In some embodiments, the acoustic sensor 204 may be disposed within the valve 202 . For example, the acoustic sensor 204 may be built into the housing of the valve 202 .
[0025] Embodiments of the valve 202 may be constructed of various materials. For example, the sealing components and surfaces of the valve 202 may be metal, plastic, and/or elastomeric. FIG. 3 shows a cross-section of an example of a valve 202 with associated acoustic sensor 204 in accordance with various embodiments. The valve 202 includes a piston 302 , an inlet/outlet seal plate 306 , a number of elastomeric seals 304 , a blind seal plate 310 , seal rings 314 , a valve body 308 , end caps 312 , springs, and various other components. As explained above, the acoustic sensor 204 may be attached to an outer surface of the valve body 308 or internally incorporated in the valve body 308 or other component of the valve 202 . Both configurations are shown in FIG. 3 . The valve monitoring system 200 can identify leaks in metal-to-metal seals (e.g., between inlet/outlet seal plate 306 and seal ring 314 ), elastomeric seals, and other seals of the valve 202 .
[0026] The acoustic sensor 202 may be any of a variety of types of transducers that convert vibration into electrical signals. The acoustic sensor 202 may include an accelerometer (e.g., a micro-electro-mechanical system (MEMS) accelerometer), a piezoelectric element, optical fibers, or other transduction element suitable for detecting vibration of the valve 202 .
[0027] Returning now to FIG. 2 , signals generated by the acoustic sensor 204 (e.g., electrical signals representative of the vibration of the valve 202 detected by the acoustic sensor 204 ) are provided to the valve monitor 206 . The valve monitor 206 processes the signals received from the acoustic sensor 204 to characterize operation of the acoustic sensor 204 . The valve monitor 206 can identify a variety of operational conditions of the valve 202 based on the signals received from the acoustic sensor 204 . In some embodiments, the valve monitor 206 can identify when the valve 202 is opening or closing based on the acoustic signals generated by the valve 202 while opening or closing. As a result, the valve monitor 206 can measure the time required to open the valve 202 and the time required to close the valve 202 . An increase in the time needed to open or close the valve 202 may indicate degradation in operation of the valve 202 . Significant change in the operation time of the valve 202 may, for example, trigger maintenance operations to replace the valve 202 prior to failure. Similarly, based on the acoustic signals generated by the valve 202 and detected by the acoustic sensor 204 , the valve monitor 206 may be able to detect whether the valve 202 is open or closed. Accordingly, the valve monitor 206 can indicate that valve 202 is in an incorrect state which may trigger action to correct the state of the valve 202 .
[0028] Using the acoustic signals generated by the valve 202 while opening or closing, the valve monitor 206 can identify static friction (stiction) in valve 202 . Generally, stiction is friction between stationary components of the valve 202 that inhibits relative motion between the components when the valve 202 is actuated. For example, stiction between sealing surfaces may inhibit opening or closing of the valve 202 . The valve monitor 206 may identify stiction in the valve 202 as delay from a point in time that valve actuation is initiated until the internal components of the valve 202 move. The valve monitor 206 can measure such actuation delay by monitoring operation of a solenoid valve of the pod 100 , or other control signal (via a valve control system) indicating that the valve 202 is being actuated, and monitoring the acoustic signature of the valve 202 . If the time delay between initiation of valve actuation and initial movement of the valve (as identified via the acoustic signals generated by movement within the valve 202 ) changes over time (most likely to increase) the change in time delay may be indicative of stiction in the valve 202 . The valve monitor 206 may report detected stiction to an authority responsible for operation of the valve 202 to allow scheduling of maintenance.
[0029] The valve monitor 206 may also detect leaks in the valve 202 based on the acoustic signals generated by the valve 202 and detected by the acoustic sensor 204 . In some embodiments of the valve 202 , a leak in the valve 202 may be indicated by acoustic signals generated at a particular frequency. FIG. 4 shows a plot of acoustic signal energy generated by the valve 202 . To produce the plot of FIG. 4 , the valve monitor 206 applies a frequency transform (e.g., a fast Fourier transform) to the signals received from the acoustic sensor 204 to generate a frequency domain representation of the signals. The increase in energy at point 402 indicates that the valve 202 is leaking. Accordingly, the valve monitor 206 may identify a particular frequency band that is indicative of a leak in the valve, and identify the valve as leaking if acoustic energy in the particular frequency band rises above a predetermined level or increased by a predetermined amount (e.g., while the valve 202 is closed).
[0030] Some embodiments of the valve monitor 206 may acquire a baseline model of steady-state acoustic data generated by the valve 202 and compare the baseline model to acoustic data generated by the valve 202 . Changes in the steady-state acoustic energy generated by the valve 202 may indicate that a leak or other undesirable condition has arisen in the valve 202 . If the valve monitor 206 determines, based on the signals received from the acoustic sensor 204 , that the valve 202 has degraded, developed a leak, or otherwise undergone a change in operational performance, then the valve monitor 206 may provide an alert indicative of the change in condition of the valve 202 . In response to the alert, maintenance or replacement of the valve 202 may be scheduled.
[0031] FIG. 5 shows a block diagram of a valve monitoring system 500 suitable for use in the drilling system 150 . The valve monitoring system 500 is similar to the system 200 described above, but includes an additional acoustic sensor 508 . As in the system 200 , the acoustic sensor 204 is coupled to the valve 202 for detection of acoustic signals generated by the valve 202 . Unlike, the acoustic sensor 204 , the acoustic sensor 508 is not coupled to the valve 202 for detection of acoustic signals generated by the valve 202 . Rather, the acoustic sensor 508 is positioned to detect acoustic signals present in the environment in which the valve 202 operates. In the BOP 156 and the riser 154 a variety of noise sources generate acoustic signals. For example, motion of a drill string passing through the BOP 156 and the riser 154 generates acoustic noise. Similarly, actuation of solenoids, valves and other devices in the BOP 156 generate acoustic noise. The acoustic sensor 508 detects the ambient acoustical noise proximate the hydraulic valve 202 , generates electrical signals representative of the ambient acoustical noise, and provides the signals to the valve monitor 506 . The valve monitor 506 applies the ambient noise signal received from the acoustic sensor 508 to filter ambient noise from the valve acoustic signals received from the acoustic sensor 204 . For example, the valve monitor 506 may subtract the ambient noise signal, or a portion thereof, from the valve acoustic signals.
[0032] Some embodiments of the valve monitor 506 may filter ambient noise from the acoustic signals received from the acoustic sensor 204 by applying a low cut filter to the valve acoustic signals, in lieu of, or in addition to use of ambient noise signals as described above. For example, if ambient noise is generally at frequencies below 100 Hz, then the valve monitor 506 may apply a low-cut filter having a 100 Hz corner frequency (or other suitable corner frequency) to acoustic signals received from the acoustic sensor 204 to remove the ambient acoustic noise.
[0033] In some embodiments, the valve monitor 506 may reduce the level of ambient noise in the valve acoustic signals using the acoustic signals provided by a plurality of the acoustic sensors 204 . For example, the valve monitor 506 may sum the acoustic signals provided by a plurality of the acoustic sensors 204 over a given time interval to generate a composite acoustic signal in which ambient noise is reinforced and valve specific acoustic signal is attenuated. Subtraction of the composite acoustic signal from the acoustic signal provided by each of the plurality of the acoustic sensors 204 may attenuate the ambient noise present in each of the resultant valve acoustic signals.
[0034] In some embodiments, at least a portion of the signal processing or preconditioning applied to the acoustic sensor output signals, and associated with the valve monitor 506 in some embodiments, may be performed proximate the acoustic sensor 204 . FIG. 6 shows a block diagram of a valve monitoring system 600 that provides preprocessing proximate the acoustic sensor 204 in accordance with various embodiments. In the valve monitoring system 600 , the acoustic sensor 204 is disposed proximate the valve 202 as explained with regard to the system 200 , and the valve monitor 608 is disposed at the surface (e.g., on the rig 152 ). The signal preprocessing circuitry 602 and telemetry transceiver 604 are disposed proximate the acoustic sensor 204 , and the telemetry transceiver 606 is disposed proximate the valve monitor 608 . The telemetry transceivers 604 and 606 may employ any of a variety of data communication protocols. For example, the telemetry transceivers 604 and 606 may employ Ethernet or Controller Area Network protocols to communicate via cabling that connects the transceivers 604 and 606 .
[0035] The signal preprocessing circuitry 602 receives the signals generated by the acoustic sensor 204 and can apply various preprocessing operations. For example, the signal preprocessing circuitry 602 may include an analog-to-digital converter to digitize the signals, an anti-alias filter, a low-cut filter to reduce ambient noise content, etc. The various operations performed by the signal preprocessing circuitry 602 may be implemented using analog or digital techniques and components in different embodiments.
[0036] The preprocessed signal generated by the signal preprocessing circuitry 602 is provided to the telemetry transceiver 604 . The telemetry transceiver 604 transmits the preprocessed signal to the telemetry transceiver 606 . The telemetry transceiver 606 receives the signal transmitted by the telemetry transceiver 604 and provides the received signal to the valve monitor 608 for further processing and use in characterization of the valve 202 as described herein.
[0037] The preprocessing circuitry 602 may also be configurable via information received from the valve monitor 608 via the telemetry transceiver 604 . In some embodiments, the signal preprocessing circuitry 602 may include field programmable components, such as a field programmable gate array or a digital signal processor, which can be configured by the valve monitor 608 to change the functionality provided by the signal preprocessing circuitry 602 . For example, the valve monitor 608 may change the corner frequency of a filter applied by the signal processing circuitry 602 , or other operational parameters, using a command transmitted via the telemetry transceiver 604 .
[0038] In some embodiments of the control pod 100 , a number of valves 202 may be located in close proximity to one another. To facilitate monitoring of a number of proximate valves 202 , some embodiments of the valve monitoring system disclosed herein may group a number of acoustic sensors 204 and associated signal preprocessing circuits 602 in an assembly that communicates with the valve monitor 608 via a single transceiver 604 that is coupled to all of the signal preprocessing circuits 602 . FIG. 7 shows a block diagram for a system 700 that includes an acoustic sensor assembly 702 . The acoustic sensor assembly 702 includes a plurality of acoustic sensing channels 704 and a telemetry transceiver 604 . Each acoustic sensing channel 704 includes an acoustic sensor 204 and associated signal preprocessing circuit 602 . The telemetry transceiver 604 manages communication with the valve monitor 608 for all of the acoustic sensing channels included in the assembly 702 . Accordingly, acoustic signal outputs of each of the signal preprocessing circuits 602 are provided to the telemetry transceiver 604 for transmission to the valve monitor 608 . Each of the acoustic sensing channels 704 may be addressable to allow the valve monitor 608 to individually communicate with and control each of the channels 704 .
[0039] In some embodiments of the acoustic sensor assembly 702 , the preprocessing circuitry 602 for multiple acoustic sensing channels 704 may be aggregated in a single device, or a single instance of the preprocessing circuitry 602 may perform preprocessing functions for a plurality of acoustic sensors 204 . Though the acoustic sensor assembly 702 is illustrated as including four acoustic sensing channels 704 as a matter of convenience, in practice the acoustic sensor assembly 702 may include any number of acoustic sensing channels 704
[0040] FIG. 8 shows another diagram of the acoustic sensor assembly 702 . In FIG. 8 , the acoustic sensors 204 , signal preprocessing circuitry 602 , and telemetry transceiver 804 are attached to a common substrate 802 . The substrate 802 may be a metal plate or housing, or may be a platform of another suitable material. The acoustic sensors 204 are arranged on the substrate 802 such that each of the sensors 204 corresponds to, and is brought into contact with, one of the valves 202 of the control pod 100 when the acoustic sensor assembly is attached to the control pod 100 . Accordingly, by attaching the substrate 802 to the control pod 100 , a plurality of valves 202 may be monitored. In some embodiments, a material that provides acoustic insulation may be disposed between the substrate 802 and each acoustic sensor 204 to reduce cross talk between the sensors 204 .
[0041] FIG. 9 shows a block diagram of a valve monitoring system 900 . The valve monitoring system 900 includes a plurality of acoustic sensor assemblies 702 . The acoustic sensor assemblies 702 are arranged, in conjunction with the telemetry transceiver 906 coupled to the valve monitor 608 , to form a ring topology. The ring topology advantageously provides redundant communication paths to each of the sensor assemblies 702 , thereby enhancing the reliability of communication with sensor assemblies 702 in the relatively harsh environments to which the sensors assemblies are subject when used to monitor the valves 202 .
[0042] FIG. 10 shows a block diagram of a valve monitor 1000 in accordance with various embodiments. The valve monitors 206 , 506 , and 608 disclosed herein may be implemented as the valve monitor 1000 . The valve monitor 1000 includes a processor 1002 and storage 1004 . The valve monitor 1000 may also include various other components that have been omitted from FIG. 10 in the interest of clarity. For example, embodiments of the valve monitor 1000 may include a display device, such as a computer monitor, user input devices, network adapters, etc. Some embodiments of the valve monitor 1000 may be implemented as a computer, such as a desktop computer, a laptop computer, a server computer, a mainframe computer, or other suitable computing device.
[0043] The processor 1002 may include, for example, a general-purpose microprocessor, a digital signal processor, a microcontroller or other device capable of executing instructions retrieved from a computer-readable storage medium. Processor architectures generally include execution units (e.g., fixed point, floating point, integer, etc.), storage (e.g., registers, memory, etc.), instruction decoding, peripherals (e.g., interrupt controllers, timers, direct memory access controllers, etc.), input/output systems (e.g., serial ports, parallel ports, etc.) and various other components and sub-systems.
[0044] The storage 1004 is a non-transitory computer-readable storage medium suitable for storing instructions executed by the processor 1002 and data processed by the processor 1002 . The storage 1004 may include volatile storage such as random access memory, non-volatile storage (e.g., a hard drive, an optical storage device (e.g., CD or DVD), FLASH storage, read-only-memory), or combinations thereof.
[0045] The storage 1004 includes valve characterization module 1006 , valve acoustic signal processing module 1008 , valve acoustic signals 1010 , and valve baseline acoustic signals 1012 . The valve baseline acoustic signals 1012 include initialization signals and/or parameters of initialization signals acquired from each valve 202 at a point in time when the valve 202 is operating at an optimal level. For example, the valve baseline acoustic signals 1012 may include valve acoustic signals acquired when the valve 202 is initially put into service, or standardized signals representative of operation of a fully functional valve 202 . The valve acoustic signals 1010 include signals detected by the acoustic sensors 204 coupled to each valve 202 . The valve acoustic signals 1010 may be processed via execution of the valve acoustic signal processing 1008 , and the results analyzed via execution of the valve characterization 1006 to determine the condition of each valve 202 .
[0046] The valve acoustic signal processing 1008 includes instructions executed by the processor 1002 to prepare the valve acoustic signals for analysis. For example, the valve acoustic signal processing 1008 may include instructions to reduce the amplitude of ambient noise present in the valve acoustic signals, to transform the time-domain valve acoustic signals into frequency-domain representations, to filter unwanted frequency content from the valve acoustic signals, and to provide other signal processing functionality disclosed herein.
[0047] The valve characterization 1006 includes instructions executed by the processor 1002 to characterize and evaluate the condition of each valve 202 . For example, the valve characterization 1006 may include instructions to compare valve acoustic signals processed via the valve acoustic signal processing 1008 to the valve baseline acoustic signals 1012 , or to determine whether the valve acoustic signals processed via the valve acoustic signal processing 1008 exhibit a trend of change indicative of valve performance degradation. In some embodiments, the valve characterization 1006 may include instructions that identify a leak in a valve 202 by identifying an increase in amplitude within a particular frequency band determined to indicate a leak. The valve characterization 1006 may also include instructions that measure the time duration of acoustic signal generated by opening or closing the valve 202 and determine whether the duration is increasing over time as an indication of performance degradation. The valve characterization 1006 may further include instructions that determine whether the valve is open or closed based on the valve acoustic signals processed via the valve acoustic signal processing 1008 . Instructions of valve characterization 1006 may cause the processor 1002 to issue an alert indicating that the valve 202 may require attention if a leak or other performance anomaly is detected. The alert may be presented on a display device or otherwise provided to an authority responsible for maintaining the integrity of the valves 202 .
[0048] The above discussion is meant to be illustrative of the principles and various embodiments of the present invention. Numerous variations and modifications will become apparent to those skilled in the art once the above disclosure is fully appreciated. It is intended that the following claims be interpreted to embrace all such variations and modifications. | An apparatus and method for monitoring valve operation. In one embodiment, an apparatus for monitoring valve operation includes a first acoustic sensor and a monitoring system. The first acoustic sensor is to couple to a valve to detect vibration of the valve. The monitoring system is communicatively coupled to the first acoustic sensor. The monitoring system is configured to receive a signal generated by the first acoustic sensor. The signal is representative of vibration of the valve. The monitoring system is also configured to identify leakage in the valve based on the signal. | 5 |
FIELD OF THE INVENTION
This invention relates to the field of cooling systems. More particularly, this invention relates to a compound refrigeration system configured to operate efficiently over a broad range of temperatures at any ambient temperature.
BACKGROUND OF THE INVENTION
Single compressor refrigeration systems are well known for cooling, freezing, storing, and transporting frozen and cooled products such as food, chemicals and other sensitive things like blood, human organs, etc. Generally, single compressor systems are inadequate for cooling a load to about -20° F. (for example ice cream) at a high ambient temperature. Commercially available refrigeration systems having a single compressor or multiple compressors in parallel can cool a load to about 0° F. Unfortunately, purchasers of refrigeration systems desire a system which can maintain a load at very low temperatures (e.g. -20° F. and lower) at high ambient temperatures (e.g. 120° F. and higher).
By way of example, consider a single compressor system for cooling a load to -20° F. in an ambient environment of 120° F. In this case, the necessary evaporator temperature is typically at least 10° F. colder than the load temperature or -30° F. Under these conditions using refrigerant R12, the evaporator pressure is expected to be approximately 12 psia and using R22, the expected pressure is approximately 20 psia. Similarly, the condenser temperature necessary to discharge heat to the ambient is about 10°-40° F. warmer than the ambient under the best case conditions (e.g. 130° F.). Therefore, the pressure in the condenser should be approximately 196 psia for R12 and 312 psia for R22. This dictates a compression ratio of 196/12≈16.5 for R12 and 312/20≈15.6 for R22. Refrigeration compressors, however, are designed and built to operate with a compression ratio no greater than 10 to 15. If the pressure ratio exceeds the manufacturer's design criteria, the compressor will break. Accordingly, neither example above could be achieved with a conventional single compressor system. Indeed, a commercially available compressor can not operate under the above conditions and accordingly, such a system would be prohibitively expensive and inefficient. Thus, commercially available single compressor systems are incapable of operating where the difference between the desired product temperature and the actual ambient temperature is very large.
Compound compressor systems are well known. These systems typically comprise low and high stage compressors coupled together in series so that refrigerant flows through both of these compressors. It is well understood that in compound compressor systems the compression ratio is split between the low and high stage compressors, thereby allowing the system to achieve low evaporator pressure (i.e. low temperature) at high ambient temperatures. The compression ratio for the compound system is the product of the compression ratio for both the low and the high stage compressors. A compound system for the R22 example described above would also have a compression ratio of at least 16 and both the low and high stage compressors would operate at equal pressure ratios, i.e., approximately 4 for each compressor. This compression ratio is well within an acceptable range of the specifications of commercially available compressors and at these conditions the compressor efficiencies are quite high.
Cooling systems also require a minimum compression ratio to operate efficiently. As the difference between the product temperature and the ambient temperature is reduced, the compression ratio for the cooling system is also reduced. If the compression ratio becomes too low, the compressor capacity becomes too large and the compressor will short cycle and eventually break. In addition, the compressors in a compound system run less efficiently than a single stage compressor system when the difference between the load and ambient temperature decreases.
What is needed, therefore, is a system and method for cooling a load of product to a desired temperature which can efficiently operate over a broad range of ambient (-60° F. to +120° F.) and load temperatures (-25° F. to +75° F.).
SUMMARY OF THE INVENTION
The present invention is directed to a universal refrigeration system configured to operate over a broad range of desired load and ambient temperatures. To accomplish this, the system includes first and second compressors, a condenser, an expansion valve and an evaporator coupled together in series. The system further includes a controller with a closing element that is movable between a first position, where refrigerant flows from the first compressor to the second compressor, a second position, where the refrigerant bypasses the second compressor and flows directly to the condenser, a third position, where the refrigerant flows from the evaporator directly to the second compressor and then to the condenser, and a fourth position, where the refrigerant is compressed and discharged by both compressors in parallel into the condenser. With this configuration, the system can be adapted to operate independently as a single stage compressor cooling system with any one or two compressors in parallel, or together in series as a compound system, depending upon the desired temperature requirements of the load and the given ambient.
Preferably, the first and second compressors each have different capacities, allowing a wider flexibility to control the temperature. Considering that compressor capacities can be controlled by changing the speed, such flexibility allows the system to operate efficiently in a wide range of desired load and ambient temperatures. In addition, this flexibility allows the system to use an environmentally friendly refrigerant, such as Freon-22, to achieve low temperatures. In the event of a failure of one or the other compressor, the system is configured to continue operation with the other compressor as a single stage compress or system until a repair can be made.
In a preferred configuration, the controller comprises a microprocessor having a temperature sensor for sensing the room temperature, which is typically the temperature of the compartment housing the product or load. The microprocessor is adapted to determine the ratio between the discharge and suction pressures of both compressors (i.e. compression ratio), which is sensed by pressure transducers. The microprocessor can also determine the ambient temperature and the temperature difference between the room and the desired load temperature input by the user. If the temperature inputted by the user has not been achieved and the compression ratio reaches a predetermined threshold value (preferably about 8 to 10), the microprocessor will move the closing element into the first position so that the system operates in the compound mode. If the temperature reaches the desired temperature before the compression ratio reaches the threshold value, the microprocessor will maintain the closing element in the second position so that the system operates in the single stage mode. Preferably, the compression ratio threshold value is inputted by the user and can be adjusted within the manufacturers, specifications.
In one embodiment, the closing element includes a first solenoid valve positioned between the first compressor outlet (discharge) and the second compressor inlet (suction) and a second solenoid valve positioned between the first compressor discharge and the condenser inlet. When the system commences operation, the microprocessor will start the first compressor, close the first solenoid valve and open the second solenoid valve as long as the compression ratio is less than the threshold value so that the refrigerant is compressed only by the first compressor (single compressor mode). If the first compressor fails, the pressure transducers will register a compression ratio of one and the microprocessor will start the second compressor deenergize first compressor and close both solenoid valves (i.e. the single compressor mode with a different compressor).
The microprocessor is configured to automatically open the first solenoid valve, start the second compressor and close the second solenoid valve when the compression ratio exceeds the threshold value so that the refrigerant is compressed by both compressors in series, i.e. compound mode. In the compound mode, the microprocessor energizes the electronic expansion valve which controls the suction temperature of the second compressor at about 65° F. by injecting liquid refrigerant into the second compressor inlet.
With the above configuration, the universal refrigeration system of the present invention can be operated in at least four different configurations, compound mode, single compressor mode with either compressor (each one having a different capacity) and single compressor mode with the compressors in parallel. This flexibility allows the system to operate over a broad range of desired load temperatures from -25° F. to 75° F. and ambient temperatures of about -60° F. to +120° F.
The above is a brief description of some deficiencies in the prior art and advantages of the present invention. Other features, advantages and embodiments of the invention will be apparent to those skilled in the art from the following description, accompanying drawings and appended claims.
BRIEF DESCRIPTION OF THE DRAWINGS
FIG. 1 shows a perspective view of a schematic diagram of the cooling system of the present invention;
FIG. 2 is a block diagram of a microprocessor based refrigeration control system;
FIG. 3 is a flow chart illustrating the operation of the microprocessor based control system of FIG. 2 for a second compressor in a single compressor mode;
FIG. 4 is a flow chart illustrating the operation of the microprocessor based control system of FIG. 2 for a first compressor in the single compressor mode; and
FIG. 5 is a flow chart illustrating the operation of the microprocessor based control system of FIG. 2 for both the first and second compressors in the compound mode.
DESCRIPTION OF THE PREFERRED EMBODIMENT
The cooling system of the preferred embodiment of the present invention can be adapted to operate in four different configurations. The system can operate as two single stage compressor systems (with either the first or second compressor operating), or both in parallel this provides the opportunity to either cool the product or just maintain the temperature of the pre-cooled product, or two compressors in series as a compound cooling system to achieve low room temperature. If the difference between the desired temperature of the product and the ambient temperature is sufficiently small, the apparatus according to the present invention can automatically configure the system to operate in the single stage mode with either one of the two compressors. The temperature difference is deemed sufficiently small if the compression ratio would be too small to operate efficiently if the system were configured in the compound mode. The compressors preferably have different capacities to provide an even broader range of cooling capability. If the difference between the set temperature of the product and the ambient temperature is sufficiently large, the apparatus can automatically configure the system to operate in the compound mode after the temperature of the load is pulled down by the single compressor until the compression ratio reaches the threshold value. The difference is deemed large if the compression ratio would exceed the acceptable specifications when operating in single compressor mode.
Referring to the drawings in detail, wherein like elements are indicated by like numerals, a closed loop refrigeration system 100 is illustrated according to the principles of the present invention. Refrigeration system 100 generally includes first and second compressors 1, 2, a condenser 3, an expansion valve 8 and an evaporator 5 coupled together in series.
Referring to FIG. 1, the operation of refrigeration system 100 in any of the above modes will be described. The hot refrigerant gas discharged by either first or second compressors 1, 2 gives up heat to the air or water in condenser 3 and condenses to a liquid. The output of condenser 3 is coupled to a check valve 23 and a receiver 4 via liquid pipes 32a and 32. The liquid passes through a liquid pipe 33 into a heat exchanger coil 19 of a suction accumulator 6. The output of heat exchanger coil 19 is coupled with a filter\dryer 7 via a liquid pipe 34. The output of filter\dryer 7 is coupled with a thermostatic expansion valve 8 and electronic expansion valve 16 via a "Y" pipe 35. For the purposes of this specification, a "Y" pipe is defined as a pipe that is plumbed to more than two elements on the cooling circuit to one another. A thermostatic bulb 18 of thermal expansion valve 8 is mounted on a cold gas pipe 37. A thermostatic bulb 17 of electronic expansion valve 16 is mounted on a cold gas pipe 39.
Expansion valve 8 is closed and the liquid refrigerant flowing through thermostatic expansion valve 8 enters an evaporator(s) 5 via a liquid pipe 36. One evaporator coil 5 is utilized in the preferred embodiment. It will be apparent to one of ordinary skill in the art, however, that first and second compressors 1, 2 can be replaced with a plurality of compressors and evaporator coil 5 can be replaced with a plurality of evaporators as is typical in conventional refrigeration systems. In addition, the invention is not limited to a thermostatic expansion valve 8 and this valve can comprise a variety of conventional valves such as an electronic expansion valve.
Expansion valve 8 throttles the liquid refrigerant, thereby lowering the pressure and temperature of the liquid refrigerant. The cold liquid refrigerant boils in evaporators 5 absorbing the heat of a room where the load is stored and evaporating into a cold gas. Additional heater(s) 20 are provided to assist in defrosting of the evaporator(s) 5. Under certain cold ambient temperatures, heater 20 can be used to maintain the product temperature higher than the ambient. The cold gas returns via a cold gas pipe 37 which is coupled to the shell of suction accumulator 6. The cold vapor in the shell of suction accumulator 6 removes some heat from the liquid refrigerant in heat exchanger coil 19 and exits suction accumulator 6. The output of suction accumulator 6 is coupled to a cold gas "Y" pipe 38 which, in turn, is coupled to first compressor 1 and to a check valve 10. The output of check valve 10 is coupled to a cold gas "Y" pipe 39 which is coupled to a first solenoid valve 11 and second compressor 2.
In the event that the system is operating in a single stage compressor mode using only second compressor 2, the cold gas from suction accumulator 6 via pipe 39 enters second compressor 2 which compresses the gas into a hot gas line 30 which is coupled to a check valve 9. Check valve 9 is coupled to a check valve 14 and to condenser 3 via hot gas "Y" pipe 31.
In the event that the system is operating in a single stage compressor mode using only first compressor 1, the cold gas from suction accumulator 6 enters first compressor 1 via pipe 38. First compressor 1 compresses the gas into hot gas line 40 which is coupled to check valve 12. which, in turn, is coupled to solenoid valve 11 (which is closed) and solenoid valve 13 (which is open). The output of solenoid valve 13 is coupled to the input of check valve 14 via hot gas pipe 41. The output of check valve 14 is coupled to the output of check valve 9 and input of condenser 3 via hot gas "Y" pipe 31.
In the event that the system is operating in a single stage compressor mode using both compressors 1, 2 in parallel, solenoid valve 13 is open and solenoid valve 11 is closed. The refrigerant will then flow along cold gas pipes 38 and 39 into compressors 1, 2 as described above.
In order to perform the compound cooling operation, two compressors are provided. The discharge of first compressor 1 is coupled to hot gas line 40, which is coupled to check valve 12. In this case, solenoid valve 13 is closed and solenoid valve 11 is open. Thus, the refrigerant flows through check valve 11 via "Y" pipe 39 into the input of second compressor 1. The hot gas discharged by first compressor 1 is cooled with liquid refrigerant injected by electronic expansion valve 16 which senses the temperature of the gas with a thermostatic bulb or temperature sensor 17 and keeps it at about 65 degrees before it enters the suction of second compressor 2. Note that the desired suction temperature of second compressor 2 can be inputted by the user.
Operating in the compound mode, refrigeration system 100 is capable of producing temperatures as cold as -25° F. even when the ambient temperature is as high as 150° F. In the compound mode, neither compressor need operate at pressure ratios in excess of the manufacturer's specification in order to achieve the necessary cooling. Compressor 1 can also cool additional rooms with products which require higher desired load temperatures then additional expansion valves and evaporators in these rooms will be installed and the suction pipe will have solenoid valves and will be connected to suction pipe 39.
In certain cold climate conditions, the ambient temperature surrounding the refrigeration system can be low enough that an insufficient pressure differential exists for thermal expansion valve 8 to open and feed the liquid refrigerant into evaporators 5 so that the cooling system will not operate. For such conditions of operation, a heater 15 is provided in the base of receiver 4. Heater 15 heats the liquid, which boils, thereby increasing the pressure in receiver 4 to a level providing sufficient pressure differential to allow the system to start normally. The increased pressure will close check valve 23 so that the pressure in condenser 3 does not change. After the system has commenced operation, heater 15 is automatically turned off. With this configuration, refrigeration system 100 can be used from the hottest to the coldest climates.
FIG. 2 illustrates a microprocessor-based control system for controlling refrigeration system 100. However, it should be understood that an analog or digital control system may achieve similar results. The control system of FIG. 2 includes a microprocessor 60, a keyboard 62 for inputting system parameters such as the desired load temperature or the compression ratio, and a display 64 for displaying the data received from microprocessor 60. A load temperature sensor 66 (or a plurality of sensors) is connected to microprocessor 60 for determining the temperature of the load to be cooled by refrigeration system 100. Solenoid valves 11, 13 are connected to microprocessor 60 in a conventional manner. Microprocessor 60 will open and close solenoid valves 11, 13 depending on whether refrigeration system 100 should be in the compound or single compressor mode, as discussed below.
First and second compressors 1, 2, each have suction transducers 70, 72, located on the inlet or suction sides of the compressors and discharge transducers 74, 76 located on the outlet or discharge side of the compressors The transducers generate an electric signal representative of the measured pressures at the inlet and outlet ports of compressors 1, 2 so that microprocessor 60 can compute the compression ratio for each compressor 1, 2. The desired compression ratio for each compressor may be input via keyboard 62. Refrigeration system 100 further includes (or may not) AC drives 78, 80 for driving compressors 1, 2, respectively. Drives 78, 80 are connected to microprocessor 60, which is adapted to vary the frequency of each drive 78, 80 thereby varying the speed of each compressor 1, 2.
When the system is operating in the compound mode, the hot compressed refrigerant exiting first compressor 1 is too hot for the inlet or suction side of second compressor 2. To decrease the temperature of the refrigerant entering second compressor 2, temperature sensor 17 is positioned at the second compressor inlet and coupled to microprocessor 60 via a signal line. When the temperature is above a predetermined level (preferably 65° F.), electronic expansion valve 16 opens so that a portion of the cool liquid refrigerant exiting heat exchanger 19 is bled through pipe 35 into the inlet of second compressor 2. The refrigerant flow rate along pipe 35 can be varied to maintain the suction temperature within a suitable range, preferably about 55°-75°.
Temperature sensors 17 and 66 and pressure transducers 70, 72, 74 and 76 control whether one or the other compressor operates, or both compressors 1, 2 operate as a single stage compressor system or compound system depending upon the desired temperature of the load in relation to the ambient temperature. In operation, the user enters the desired temperature into controller 60 via a keyboard 66. Controller 60 then calculates the compression ratio at each compressor 1, 2 with the transducers and checks the temperature difference between the desired load and room temperatures. When the compression ratio reaches the preset threshold value (preferably about 8-10) and the desired temperature is not yet achieved, controller 60 automatically configures the system to operate in compound mode. Otherwise, it configures the system to operate in single stage compressor mode using either the first or second compressor 1 or 2. If the system determines that one of the compressors is non-functional, it can automatically switch to operation as a single stage compressor system using the other compressor.
FIGS. 3-5 illustrate flow diagrams for the control system shown in FIG. 2 when refrigeration system 100 is operating in the compound and single compressor modes. FIG. 3 illustrates the standard operating cycle flowchart for first compressor 1 (note that operation of second compressor 2 is similar to that of first compressor 1 so only FIG. 3 will be described in detail). As discussed above, the user first inputs a desired temperature through keyboard 62. First compressor 1 is then started at a low speed and solenoid valve 13 is opened. Microprocessor 60 calculates the temperature decrease rate and the compression ratio across first compressor 1 with the sensors and transducers. If the temperature inputted by the user has not been achieved and the compression ratio reaches a predetermined threshold value (preferably about 8 to 10), the microprocessor will close solenoid valve 13 and open solenoid valve 11 so that the system operates in the compound mode. If the compression ratio ever drops as low as 1, first compressor 1 has suffered a breakdown and second compressor 2 will be started.
If the temperature reaches the desired temperature before the compression ratio reaches the threshold value, the microprocessor will preferably slow down first compressor 1 in increments to about 66% of the speed starting about 3° F. above the desired temperature. If at the slowest compressor speed the temperature reaches the desired room temperature, the microprocessor will stop the compressor at the set point temperature. When the room temperature goes up one degree above the set point, the compressor would come on maintaining the room temperature within 1° F. of the user inputted temperature.
FIG. 5 illustrates operation of refrigeration system 100 in the compound mode. First, microprocessor 60 determines if both compressors 1, 2 are working, then starts them at a low speed. Solenoid valve 13 is closed and solenoid valve 11 is opened so that refrigerant flows from the discharge of first compressor 1 to the inlet of second compressor 2. Electronic expansion valve 16 is actuated to control the temperature at the inlet of second compressor 2. As long as the compression ratio from condenser 2 to evaporator 5 remains above 8, refrigeration system will remain in the compound mode. When the compression ratio drops below 8, microprocessor 60 will configure the solenoids and stop one of the compressors so that the refrigerant only flows through one compressor. If the compressions ratio across either compressor 1, 2 drops to 1, that compressor will be deenergized, the other compressor will be started and the solenoids configured so that refrigerant only flows through the working compressor.
The above is a detailed description of a particular embodiment of the invention. It is recognized that departures from the disclosed embodiment may be made within the scope of the invention and that obvious modifications will occur to a person skilled in the art. The full scope of the invention is set out in the claims that follow and their equivalents. Accordingly, the claims and specification should not be construed to unduly narrow the full scope of protection to which the invention is entitled. | A broad range cooling system is provided which can operate to cool and store a product load to a predetermined temperature in the range of -25° F. to +75° F. over an ambient temperature range of -60° F. to 150° F. The system includes two compressor systems which are configurable to operate independently as single stage compressor cooling systems each having a unique cooling range, or together as a single stage compressor system or a compound system, depending upon the desired temperature requirements of the load and the existing ambient. In the event of a failure of one or the other compressor, the system is configured to continue operation with the other compressor as a single stage compressor system until a repair can be affected. | 5 |
BACKGROUND OF THE INVENTION
The present invention relates to apparatus for testing sonobuoys and more particularly to apparatus for simulating sea current and wave motion while a sonobuoy is operating in a relatively calm body of water.
In the past, one method of imparting motion to a sonobuoy being operated in a relatively calm body of water was by the use of mechanical cams and linkage to cause the sonobuoy to move in a vertical direction. The motion, however, was generally sinusoidal and did not closely simulate motion of the sea which is a combination of sea current and waves. Also, the cams and linkage produced considerable noise which was picked-up by the hydrophone being tested.
SUMMARY OF THE INVENTION
The present invention relates to a sea state and sea current simulator for testing a sonobuoy operating in a relatively calm body of water, such as a lake. Sea current is simulated by pulling a floating platform through the water by using a winch which is stationed on shore. A sonobuoy being tested is attached to the floating platform by a cable. A drum, rotatably mounted on the floating platform and driven by a reversible motor, winds and unwinds the cable going to the sonobuoy and imparts vertical motion to the hydrophone of the sonobuoy similar to motion caused by ocean waves.
Various sea states can be simulated by storing in separate programmable read-only memories (PROMs) digital representations of amplitudes. An output from a selected PROM is converted to an analog voltage, and a control unit cycles the reversible motor in a manner to simulate the desired sea state.
It is therefore a general object of the present invention to provide a simulator for imparting both horizontal and vertical motions to a sonobuoy being tested in a relatively calm body of water.
Another object of the present invention is to provide a simulator which will simultaneously duplicate sea current and wave motion.
Other objects and advantages of the present invention will become readily apparent from the following detailed description of the invention when considered in conjunction with the accompanying drawing.
BRIEF DESCRIPTION OF THE DRAWING
FIG. 1 is a perspective view showing major components of a sonobuoy;
FIG. 2 is a block diagram of a preferred embodiment of the present invention; and
FIG. 3 is a block diagram showing a manner of programming a reversible motor to impart motion to a cable attached to a sonobuoy.
DESCRIPTION OF THE PREFERRED EMBODIMENT
FIG. 1 of the drawing shows the major components of a sonobuoy 11, which would normally be deployed from an aircraft by means of either a rotochute or a parachute. After sonobuoy 11 is in the water, a long cable 12 is played-out to deploy a hydrophone 13 at a predetermined depth. A stabilizer 14 is also provided at the end of cable 12 adjacent hydrophone 13. A float 15, which contains transmitting equipment and an antenna 16, supports hydrophone 13, and float 15 is subjected to the wave and current motion of the sea. Float 15, in turn, imparts its motion to hydrophone 13, and it is this motion which is to be simulated when testing a sonobuoy in a relatively calm body of water, such as a lake.
Referring now to FIG. 2 of the drawing, a system is shown for testing a sonobuoy 11 wherein both wave action and sea current are simultaneously simulated. A floating platform 17 is pulled at a predetermined speed by a winch 18, which is placed on shore, to simulate sea current. A control panel 20 is provided to control the speed of winch 18. A very long cable 19 is played-out, and is rewound onto winch 18 to simulate sea current. Sonobuoy 11, which is being tested, is attached by cable 21 to a drum 22 which is rotatably mounted on platform 17 and sonobuoy 11 is towed through the water to simulate sea current. Drum 22 is oscillated so that cable 21 is raised and lowered thereby simulating wave action.
Referring now to FIG. 3 of the drawing, there is shown an arrangement for controllng the oscillation of drum 22 so that a desired sea state is simulated. The arrangement is capable of simulating three sea states, that is, sea-states 3, 4, and 5, however, if desired, additional sea-states might be simulated. Sea-state numbers have been assigned for various conditions and a sea-state 3 condition has waves which are 4 feet high, sea-state 4 condition has waves which are 8 feet high and sea-state condition 5 has waves which are 12 feet high. Three programmable read-only memories (PROMs) 23, 24, and 25 are programmed to digitally represent three sea-state conditions 3, 4, and 5, respectively and a selector switch 26 is provided for selecting a desired sea state. Each PROM can contain many thousands of digital words, each representing an amplitude which has been determined in advance. Also, each PROM contains a number of test sequences of desired length in time, such as a time of 1000 seconds. A 10-bit binary counter 27 and clock 28 are provided for addressing the three PROMs 23, 24, and 25, so that the desired test sequence is executed.
The output of the selected PROM is connected to a digital to analog converter 29 which converts the stored digital representation of amplitude in a PROM to analog representations of amplitude of wave motion. The output from converter 29 is applied as one of four inputs to an operational amplifier 31. A motion sensor 32, which is located in the water, also provides an input to operational amplifier 31 to cancel out small motions which might be in the body of water being used for making tests. Another input to amplifier 31 is provided from positioning potentiometer 33 which can be adjusted to position drum 22 to a position so that ample cable 21 is available from drum 22 to permit the desired excursion of sonobuoy 11. The fourth input to amplifier 31 is from feedback potentiometer 34 which is connected to drum 22 through a gear box 35, which permits the use of a single turn potentiometer having no end stops thus permitting greater freedom of drum rotation.
Operational amplifier 31 sums the four inputs to drive a direct current reversible motor 36 through a power amplifier 37. The polarities of the input signals to amplifier 31 are chosen so that the output from converter 29 and the output from potentiometer 34 form a position servomechanism system. Resistor 38 and capacitor 39 form a compensation network which provides the servomechanism system with the desired static and dynamic characteristics. A battery 41 furnishes power necessary to drive motor 36 and its controls, which are shown as box 42 in FIG. 2 of the drawing.
In operation, winch 18 and control panel 20 would normally be placed on shore and the speed of winch 18 would be regulated to wind cable 19 so that platform 17 would be towed at a desired speed to simulate a sea current. A desired sea state is then selected, by setting switch 26, and drum 22 is oscillated by motor 36. As drum 22 is oscillated, cable 21 is alternately wound and unwound from drum 22 and as cable 21 is attached to sonobuoy cable 12, hydrophone 13 is raised and lowered in a manner similar to its movement by actual sea waves. The simulation is very realistic since any waveform can be programmed into the PROMs. As a particular sea state can be characterized by its energy content of its component frequencies, a sea state can be created by a number of non-harmonic frequencies with certain amplitudes and phases. These can be synthesized and summed by a computer and the resultant amplitudes placed in the PROMs.
The use of a powerful torque motor 36 which is directly coupled to drum 22 minimizes both mechanical and electrical noise which would be picked up by the sonobuoy sensor. Also, the placement of winch 18 on shore, isolates noise from the sonobuoy sensor.
It can thus be seen that a simulation system for testing a sonobuoy is provided which imparts both horizontal and vertical motion to an operating sonobuoy thereby simulating ocean current and drift and wave action.
Obviously many modifications and variations of the present invention are possible in the light of the above teachings. It is therefore to be understood that the invention may be practiced otherwise than as specifically described. | Apparatus is provided for simulating an ocean environment for sonobuoys wh are being tested in a relatively calm body of water. A floating platform is towed through water to simulate a sea current, and a sonobuoy being tested is attached by a cable to the floating platform. A drum, driven by a reversible motor, winds and unwinds the cable to simulate wave action while the floating platform is being towed. | 6 |
OBJECT OF THE INVENTION
The present invention relates to a structure meant to be coupled to machinery for treating surfaces, such as an asphalt millers, levellers, pavers or asphalt heaters, as means for support and positional regulation of the automated levelling systems fitted in these machines to detect the unevenness of the ground so that the asphalt is properly distributed and the irregularities are smoothed out.
The object of the invention is to provide, in addition to an optimal attachment of the height sensors, a great ease of operation when changing the length of action of said sensors, adapting said position to the specific requirements of each case.
BACKGROUND OF THE INVENTION
As it is known, machinery such as asphalt millers, levellers, pavers or asphalt heaters, and in general machines for treating surfaces, are fitted with a number of sensors, generally three, to distribute the asphalt smoothly in view of the unevenness of the ground, with these sensors being separated from each other by between 4 and 16 metres. The sensors convey the information obtained on the ground to a control unit that, in view of the irregularities, will control the asphalt flow supplied by the machine at each time.
In order to support said sensors, and particularly in order to adjust their spacing, rigid bolted members 2 to 3 metres in length are currently used, which preclude an instantaneous adjustment of the system and force to stop the machine to perform said operation, with a considerable assembly time.
Also known is the use of jointed strips of similar dimensions to the aforementioned ones that fold and unfold depending on the distance to be controlled.
This system is cumbersome and unpractical, particularly for use in narrow streets or areas where it is difficult to obtain the space required to perform the folding and unfolding manoeuvre.
DESCRIPTION OF THE INVENTION
The support structure disclosed by the invention solves the aforementioned problems in a fully satisfactory manner, by means of a telescoping design of the two arms that support the sensors, emerging from a centre core or web with respect to which said arms can slide by means of bearings that ensure a smooth motion of the arms and by the existence of fast attachment means for the various sectors of the telescoping arms and for attaching the vertical bars bearing the sensors and said sensors to the aforementioned arms.
More specifically, the centre web is embodied as a cage, preferably made of steel or some other strong material, which given the absence of play determined by the aforementioned bearings allows a transverse motion of the telescoping arms, and which has a main support for its attachment to the asphalt beater that separates and lifts the web itself, as well as being provided with a support for the system control unit and optionally with a mast allowing to brace the telescoping arms when their extension or effective length requires so.
The telescoping arms, embodied as tubes of aluminium or another lightweight and strong material, are connected to each other by caps made of Teflon (polytetrafluoroethylene) or another low-friction material, as well as having bearings that ensure ideal sliding conditions without clearance, as well as having fast-action locking means in each segment that act on the next adjacent segment in order to lock the arm at any effective length that is required of it.
The end segment of each arm is provided at its free end with a fast-closure clip for attaching the vertical tube that supports the corresponding sensor, with another similar clip provided in the centre web for the sensor occupying said position. However, it is obvious that clips can also be provided at the free end of each segment of the telescoping arms when a greater number of sensors is used.
It turn, each sensor will have an element for attachment to the corresponding tube, and the height of the sensor can be adjusted as a function of the position of the vertical tube with respect to the upper clip to which it is attached.
In this manner, a support structure is obtained in which the various sensors can adopt any relative position deemed suitable, which position can be changed in an extremely quick and simple operation, with full operational reliability and with full stability of said sensors.
DESCRIPTION OF THE DRAWINGS
As a complement of the description being made and in order to aid a better understanding of the characteristics of the invention, according to an example of a preferred embodiment, a set of drawings is provided as an integral part of the present description where for purposes of illustration only and in a non-limiting sense the following is shown:
FIG. 1 shows a perspective view of a structure for support and positional regulation of automated levelling systems according to the object of the present invention, suitably coupled to an asphalt heater in accordance with a preferred embodiment where each arm of the structure has three telescoping segments and in which three sensors are used.
FIG. 2 shows a similar perspective view to FIG. 1, wherein the structure is uncoupled from the machine and its arms are fully retracted.
FIG. 3 shows a perspective enlargement of one of the attachments of the structure.
FIGS. 4 and 5 show corresponding perspective views of another two types of attachments that are used in said structure.
PREFERRED EMBODIMENT OF THE INVENTION
In view of the above-described figures, it can be appreciated that the structure of the invention consists of a centre web ( 1 ) that forms a sort of rectangular prismatic cage, specifically by means of sections that correspond to the edges of said imaginary prism, with the face of the prism fitted on the machine ( 2 ) being attached to a strong tube ( 3 ) disposed with a downwards and outwards inclination, to define the bridge that joins the centre web ( 1 ) to said machine ( 2 ), as well as having a support ( 4 ) for the control unit ( 5 ) and optionally a mast, not shown in the drawings, to brace the arms ( 6 - 6 ′) when required.
The arms ( 6 - 6 ′) are set longitudinally inside the centre web ( 1 ), superposed as seen particularly in FIG. 2, and aided by bearings ( 7 ) mounted on transverse shafts ( 8 ) that are meant to ensure a perfect fit of the arms ( 6 - 6 ′) in the web ( 1 ) as well as optimal sliding conditions of said arms.
In this way, the initial segment of each arm ( 6 ) can adopt any position within the web ( 1 ), from a position of maximum retraction to one of maximum extensions, as is the case with each segment of each arm ( 6 - 6 ′) with respect to the other segments.
The various segments of each arm ( 6 - 6 ′) are embodied as aluminium tubes, as mentioned above, preferably with a rectangular section, that are perfectly fitted to each other with the aid of Teflon or similar caps and that are also aided by bearings to facilitate their sliding.
The various segments of each arm ( 6 - 6 ′) can be locked in any of their operational positions by means of anchorings ( 9 ), as shown in FIG. 3, comprised of a baseplate ( 10 ) attachable to the same segment of the arm ( 6 - 6 ′) from which rises vertically a bracket ( 11 ) to which it is jointed by means of a pair of connecting rods ( 12 ), an actuation lever ( 13 ) ending on one of its ends in a shaft ( 14 ) that in turn ends in a rubber plunger or the like ( 15 ), meant to rest on the adjacent segment of the arm ( 6 - 6 ′) when the grip ( 16 ) of said lever ( 13 ) is suitably operated, with the locked position maintained in a stable manner with the aid of a swivelling cap ( 17 ).
On the free end of the terminal segment of each arm ( 6 - 6 ′), and optionally on the intermediate segments and in all cases on the centre web ( 1 ), with the aid of a small auxiliary support ( 18 ), are attached the corresponding clips ( 19 ), as shown in detail in FIG. 4, consisting of an open tube that is referenced ( 19 ) whose opening is framed by two parallel brackets ( 20 ), on having an orifice ( 21 ) and the other a notch ( 22 ) on which acts a fast-action clamp ( 23 ) such that said clips act as clasps for the corresponding vertical tubes ( 24 ) that can thereby adjust their height with respect to the ground, and which incorporate on their lower end attachment means ( 25 ) for the corresponding sensors, that are duly connected to the control unit ( 5 ).
As can be inferred from the above description, the effective length of the arms ( 6 - 6 ′) can be minimal, almost equivalent to that of one of its comprising segments, such as in an inoperative position of the automated levelling system, from which position it is possible to separate the sensors by any distance required by simply releasing the anchorings ( 9 ) and telescopically extending the segments of the arms ( 6 - 6 ′) to the desired position of the tubes ( 24 ) which support said sensors, at which time the position of the sensors is locked by an operation in the opposite sense of the anchorings ( 9 ), which is also performed quickly and easily. Similarly, the height of the sensors can be adjusted by loosening the clips ( 23 ) and performing a vertical and telescoping displacement of the corresponding tubes ( 24 ).
FIG. 5 shows an alternative embodiment ( 25 ′) of the attachment means ( 25 ) of the sensors, although it should be obvious that the embodiment of the anchorings and attachments is simply shown by way of example and can be replaced by any other one deemed suitable without affecting the essence of the invention. | A structure to be coupled to a machine for treating surfaces, comprising a centre web ( 1 ) joined to a machine ( 2 ) in which are movably and tightly fined with the aid of bearings a pair of telescoping superposed arms ( 6-6 ′) whose segments can be locked at any relative position, the segments ending in clips ( 19 ) for attaching the vertical tubes ( 24 ) that in turn incorporate on their lower corresponding sensors, with another clip ( 25 ) provided in the centre web ( 1 ) for attaching another sensor at this intermediate position. The sensors are thus capable of adopting any relative separation with adjustment operations that are extremely quick and simple, by simply releasing and again locking, while the height of said sensors can also be adjusted by loosening and tightening the clips ( 19 ). | 4 |
BACKGROUND OF THE INVENTION
1. Field of the Invention
This invention relates to the art of rewind apparatus.
2. Brief Description of the Prior Art
The following prior art U.S patent is made of record: U.S. Pat. No. 2,696,784.
SUMMARY OF THE INVENTION
The primary purposes of the invention is to provide a simple apparatus for gradually applying driving force to a rewind shaft and for gradually removing the driving force so that rewinding can be accomplished smoothly. In prior art rewind apparatus which abruptly apply and remove torque from the rewind shaft various problems can exist such as the application of a jerk to the web upstream from the apparatus. In the disclosed environment of the invention, namely, in a printing press, such a jerk can have an adverse effect on printing registration. Additional disadvantages are possible, e.g., breakage of the web, and the application of abrupt changes in forces on the drive mechanism. According to the invention, a sleeve is received about the rewind shaft. The sleeve is continuously driven and in its one position applies a negligible amount of torque to the rewind shaft. Another sleeve on the shaft has a cam surface which cooperates with a cam surface on the one sleeve so as to effect selectively skewing of the one sleeve on the shaft. By causing the one sleeve to bind on the shaft, as by skewing the one sleeve on the shaft, clutching is effected between the one sleeve and the shaft. A cam plate cooperates with a stationary cam surface on the rewind frame. A roll, under which the web passes, is raised by the web when the web becomes taut and is lowered by the web when the web becomes slack. The roll controls the position of the cam plate selectively to effect movement of the one sleeve into and out of clutching relation relative to the shaft. Wear on the clutching surface of the one sleeve is not detrimental but rather is advantageous in that while skewed there is greater contact between the one sleeve and the shaft. A lost-motion connection in the linkage between the roll and the cam plate prevents the removal of torque from the rewind shaft until after sufficient tension develops in the web. The frame is comprised of a plate which cantilever mounts a pair of guides, the roll and the rewind shaft. This cantilever arrangement allows for easy threading of the web and removal of the rewound web.
BRIEF DESCRIPTION OF THE DRAWINGS
FIG. 1 is a top plan view of rewind apparatus together with printing apparatus:
FIG. 2 is a side elevational view of apparatus shown in FIG. 1;
FIG. 3 is a side elevational view taken along line 3--3 of FIG. 1;
FIG. 4 is an enlarged, fragmentary, side elevational view of the apparatus;
FIG. 5 is a view taken generally along line 5--5 of FIG. 1;
FIG. 6 is a fragmentary partly sectional view of the clutch arrangement of the rewind apparatus, in the clutched position;
FIG. 7 is a view similar to FIG. 6, but showing the clutch arrangement in the unclutched position; and
FIG. 8 is an exploded perspective view of the drive input, the clutch and part of the clutch control structure.
DESCRIPTION OF THE PREFERRED EMBODIMENTS
Referring to FIGS. 1, 2 and 3, there is shown printing apparatus generally indicated at 10 and rewind apparatus generally indicated at 11. The printing apparatus 10 is known per se in the prior art and includes a pair of feed rolls 12 and 13, a printing roll 14 and a platen roll 15 mounted in a suitable frame 16. The feed roll 12 and the printing roll 14 are driven in synchronism through gears 17, 18 and 19. The gears 17, 18 and 19 are secured to respective shafts 20, 21 and 22 journaled in the frame 16. Because of the discontinuous nature of the outer surface of the roll 12 indicated at 17 the web W is advanced intermittently by the rolls 12 and 13.
The rewind apparatus 11 comprises a frame 23 bolted to the printing press frame 16. A curved guide 24 and a round shaft or guide 25 are secured to one side of the rewind frame 23. A pair of side guides 26 are adjustably secured to the guide 25 so as to accommodate a web W of any width. A frame member or bearing block 27 of the frame 23 mounts a bearing 28. A rewind shaft 29 is rotatably mounted in the bearing 28. A hub generally indicated at 30 comprised of a pair of hub members 31 and 32 is adjustably secured to the shaft 29 to be able to rewind a web W of any desired width. In the illustrated embodiment, the hub members 31 and 32 are shown to mount a suitable core 33 onto which web W is rewound.
A suitable pulley belt 34 passes over a pulley 35 secured to the shaft 20 and over a pulley 36 secured to a sleeve 37. In that the shaft 20 rotates continuously, pulleys 36 and 38 and the sleeve 37 also rotate continuously. The pulley 36 is considered to be an input member. As best shown in FIGS. 2 and 3, the pulley belt 34 makes a figure eight so that the pulleys 35 and 36 rotate in the opposite directions. The sleeve 37 and the shaft 29 cooperate to provide a clutch generally indicated at 38.
As shown in FIGS. 2 through 5, the web W passes around the guide 24, downwardly and under and around a roll 39. From the roll 39 the web W extends up and over the guide 25 to the web roll R. The roll 39 is rotatably mounted on a shaft 40 which is secured to a link 41. The arm 41 and an arm 42 are secured to a shaft 43 which is journaled in the rewind frame 23. The link 42 has an elongated slot 44 best shown in FIG. 4 which provides a lost motion connection between the link 42 and a rigid rod 45. The one end of the rod 45 is bent at a right angle and is received in the slot 44 and its other bent end is received in a hole 46 in a cam plate 47. The cam plate 47 has a hole 48 (FIG. 8) which receives the shaft 29. Accordingly, shifting movement of the rod 45 will cause the cam plate 47 to rotate on the shaft 29.
The cam plate 47 is comprised of a generally flat metal plate having diametrically opposed outturned portions 49 with cam surfaces 50. The frame member 27 has cam surfaces 51 with which the cam surfaces 50 can cooperate. Movement of the cam plate 47 from the position shown in FIG. 7 to the position shown in FIG. 6 causes the cam plate 47 to rotate and shift in a direction axial to the shaft 29 so as to move a sleeve 52, which receives the shaft 29, toward the sleeve 37. The sleeve 37 has cam surfaces 53 and the sleeve 52 has cooperable cam surfaces 54. The cam surfaces 53 and 54 are shown to be in camming cooperation in FIG. 6, to be touching but out of camming cooperation in FIG. 7. In the position shown in FIG. 6, sleeve 37 and the pulley 36 which it mounts are shown to be slightly skewed with respect to the shaft 29. In the skewed position of the sleeve 37, the sleeve 37 exerts a binding force on the shaft 29 to effect clutching engagement between the rotating sleeve 3 and the shaft 29. This clutching engagement causes the shaft 29 to rotate. Rotation of the shaft 29 causes the hub 30 to rotate and the web W to be wound onto the core 33. The sleeves 37 and 52 are comprised of porous lubricant-containing bearing material such as sintered bronze in which pores in the material act as reservoirs for lubricant. Such materials are commercially sold under the name "Oilite".
With reference to FIGS. 3 and 4, the roll 39 is shown in its lowered position in which there is little tension in the web W. In this position, the link 42 and arm 41 are in their clockwise positions and consequently the cam plate 47 is also in its clockwise position. In the clockwise position of the cam plate 47 (FIGS. 3, 4 and 5), the cam plate 47, and the sleeves 37 and 52 are in their cooperating position shown in FIG. 6. Because of the relative sizes of the pulleys 35 and 36, the shaft 29 will rotate at a greater angular speed than the shaft 20. Also, the peripheral speed of the web roll R is greater than the speed of the intermittently fed web W. Accordingly, tension in the web W will increase until the roll 39 is in the position shown by phantom lines in FIG. 3. In this position one end of the rod 45 has moved to the other end of the elongated slot 44 and the cam plate 47 has been rotated counterclockwise as best shown in FIG. 5, thereby moving the cam plate 47 to the position shown in FIG. 5. When the cam plate 47 is in the position shown in FIG. 5, the same position in which the cam plate 47 is shown in FIG. 7, the sleeve 52 has moved to the position shown in FIG. 7, and the sleeve 37 is no longer skewed on the shaft 29. Because of the clearance, illustrated exaggeratedly in FIG. 7, the sleeve 37 rotates freely relative to the shaft 29 which is now stationary.
Should slack again develop in the web W due to the fact that the feed rolls 12 and 13 are feeding the web and the rewind shaft 29 is not rotating, the roll 29 will again descend to the position shown in FIGS. 3 and 4 and the associated parts including the cam plate 47 and the sleeve 52 will move to the position shown in FIG. 6, thereby effecting clutching of the sleeve 37 and the shaft 29.
The lost-motion connection provided by the slot 44 and the turned-in end of the rod 45 will enable the roll 39 to be raised a limited amount before the cam plate 47 is shifted from the position shown in FIG. 7 to the position shown in FIG. 6. The relatively small weight of the roll 39 is such that the slight increase in tension which causes the roll 39 to rise prevents the apparatus 11 from becoming too highly sensitive to changes in web tension.
A spring 55 passes at one end through a hole 56 in the cam plate 47 and is connected at its other end to an adjusting screw 57 threadably received in a block 58 mounted to the frame 23. The spring 55 acts to normally urge the cam plate 47 to its clockwise position as viewed in FIG. 4, for example, and to urge the rod 45 into the position shown in FIG. 4. As the roll 39 is raised and the end of the rod 45 bottoms in the other end of the slot 44 of the link 42, the spring 55 adds resistance to raising of the roll 39. The more the resistance the more delay is before the clutch 38 is engaged and the sooner the clutch 38 will be disengaged. The screw 57 can be adjusted to increase the force on the cam plate 47 and the associated structure. Thus, the amount of tension in the web W is related to the force exerted by the spring 55.
As best seen in FIG. 1 the guides 24 and 25, the roll 39 and the shaft 29 are shown to be mounted by the rewind frame 23 in a cantilevered arrangement. This cantilevered arrangement facilitates easy access to the web W as when threading the web W through the apparatus and when removing a web roll R of the rewound web. This cantilevered arrangement is also conducive to low-cost manufacture in that there are no bearings to align and no concomitant misalignment problems.
Other embodiments and modifications of this invention will suggest themselves to those skilled in the art, and all such of these as come within the spirit of this invention are included within its scope as best defined by the appended claims. | There is disclosed apparatus for rewinding a web. The apparatus comprises a simple inexpensive clutch arrangement which gradually applies and removes driving force from a rewind shaft. A pair of bearing sleeves are received about the shaft. The sleeves have cooperable cam surfaces. The first sleeve is continuously driven. A roll in contact with the web senses the tautness or slack in the web and selectively operates a cam to move the sleeves into and out of camming cooperation. When in camming cooperation, the first sleeve binds on the shaft to effect clutching and consequent rotation of the shaft. | 1 |
CROSS-REFERENCE TO RELATED APPLICATIONS
[0001] This application claims the priority benefit of Korean Patent Application No. 2011-0076436, filed on Aug. 1, 2011 in the Korean Intellectual Property Office, the disclosure of which is incorporated herein by reference.
BACKGROUND
[0002] 1. Field
[0003] Embodiments relate to a washing machine.
[0004] 2. Description of the Related Art
[0005] A washing machine is an apparatus configured to wash laundry by use of electric power. In general, the washing machine includes a tub configured to store a washing water, a rotating tub rotatably installed inside the tub, a pulsator rotatably installed on the bottom of the rotating tub, and a motor and a clutch that are configured to rotate the rotating tub and the pulsator.
[0006] In a state that a laundry and a washing water containing detergent are input in the rotating tub, and if the rotating tub and the pulsator rotate, the pulsator stirs the washing water together with the laundry to remove dirt on the laundry.
[0007] In order to increase the washing capacity of a washing machine, the rotating tub needs to be larger, that is, the rotating tub needs to be increased in diameter or in height. If a rotating tub has a larger size, a tub accommodating the rotating tub and a cabinet accommodating the tub also need to be enlarged along with the increase of the rotating tub.
[0008] The enlarging of a cabinet, which corresponds to an external appearance of the washing machine, is limited by the space of an installation area. In addition, for a vertical-shaft washing machine, the increased height of a washing machine causes a difficulty in loading and unloading laundry. Accordingly, there is a need for a washing machine be capable of eliminating such an inconvenience and yet increasing the washing capacity.
SUMMARY
[0009] In an aspect of one or more embodiments, there is provided a washing machine capable of increasing the washing capacity without enlarging the external appearance.
[0010] In an aspect of one or more embodiments, there is provided a washing machine capable of discharging a washing water during a washing operation or a spin-dry operation while completely isolated from electronic parts and thus reducing the risk of a power failure and fire.
[0011] In accordance with an aspect of one or more embodiments, there is provided a washing machine includes a body, a rotating tub, a pulsator, a driving part and a base plate. The rotating tub is rotatably disposed inside the body. The pulsator is rotatably disposed inside the rotating tub. The driving part is provided on a lower portion of the rotating tub to selectively rotate the rotating tub and the pulsator. The base plate has the driving part fixed thereto. A waterproofing member is provided between the base plate and a bottom of the body to seal the driving part and to prevent water from being infiltrated into (reaching) the driving part.
[0012] The waterproofing member includes a diaphragm configured to absorb vibration of the driving part.
[0013] The waterproofing member includes a plurality of wrinkled parts, a first fixing part extending upward from the wrinkled part, and a second fixing part extending downward from the wrinkled part.
[0014] The base plate includes a first coupling part which is provided at a lower surface of the base plate such that the first coupling part is coupled with the first fixing part.
[0015] The washing machine further includes a mounting part configured to support the body, wherein the mounting part includes a bottom plate forming the bottom of the body and a second coupling part which is provided at a lower surface of the bottom plate to be coupled with the second fixing part.
[0016] The waterproofing member further includes a wire which is provided in a form of a ring and configured to press and fix each of outer sides of the first fixing part and the second fixing part.
[0017] The mounting part further includes a moisture infiltration preventing guide configured to prevent water from being infiltrated to (reaching) a cable that is withdrawn from the driving part.
[0018] The moisture infiltration preventing guide is vertically provided inside the body.
[0019] The rotating body includes a side wall that extends from a bottom of the rotating body while being slanted with increase of a diameter, and at least one drain hole is formed in an upper end portion of the side wall.
[0020] The bottom plate is provided with a first drain port configured to discharge a washing water that is discharged through the drain hole and fallen.
[0021] The driving part includes a motor, a clutch configured to selectively transfer a power of the motor to the rotating tub and the pulsator, and a flange connecting a driving shaft of the clutch to a bottom of the rotating tub, and
[0022] The flange includes a first through-hole, which is provided in a center of the flange to allow the driving shaft to be coupled thereto, and a second through-hole, which is formed around the first through-hole in a circumferential direction of the first through-hole to pass water during a washing operation and a rinsing operation.
[0023] The based plate is provided with a second drain port configured to discharge a washing water that is discharged through the second through-hole and fallen during a washing operation or a rinsing operation.
[0024] The washing machine further includes a suspension member connecting the base plate to a upper portion of the body, wherein the suspension member has a first end connected to at least one connecting bracket, which is provided on the base plate, and a second end connected to an upper edge of the body.
[0025] In accordance with an aspect of one or more embodiments, there is provided a washing machine includes a body, a rotating but, a base plate and a diaphragm. The body forms an external appearance. The rotating tub is rotatably installed inside the body and is provided at a lower portion thereof with a driving part. The base plate is connected to an upper portion of the body by at least one suspension member such that the driving part is fixed to the base plate. The diaphragm is disposed between the base plate and a bottom of the body to seal the driving part and to absorb vibration.
[0026] The diaphragm includes a plurality of wrinkled parts and a fixing part extending upward and downward from the wrinkled part.
[0027] The base plate includes a coupling groove that is formed by protruding a lower surface of the base plate such that a first side of the fixing part is fixed to the base plate.
[0028] The bottom of the body is provided at a center thereof with an installation hole that allows the driving part to pass therethrough, and wherein a rim of the installation hole is bent downward such that a second side of the fixing part is fixed to the rim.
[0029] The washing machine further includes a wire which is provided in a form of a ring and configured to press and fix an outer circumference of the fixing part.
[0030] The washing machine further includes a moisture water infiltration preventing guide which is provided on the bottom of the body to prevent water from being infiltrated to (reaching) a cable that is withdrawn from the driving part.
[0031] In an aspect of one or more embodiments, there is provided a washing machine which can increase the washing capacity without enlarging the external appearance and thus can wash a larger amount of laundry at one time, thereby enhancing the washing efficiency.
[0032] According to an aspect of one or more embodiments, the same washing capacity is ensured with a smaller external appearance, so that the installation is less affected by a limited installation space. In addition, the laundry can be easily loaded and unloaded, thereby improving the convenience of a user.
[0033] In addition, a washing water discharged during a washing operation or a spin-dry operation is completely isolated from electronic and installed parts, and the risk of a power failure and fire is reduced. In addition, one or more embodiments may prevent a rotating body from colliding with a wall surface in an abnormal vibration state, thereby ensuring the stability of the washing machine.
BRIEF DESCRIPTION OF THE DRAWINGS
[0034] These and/or other aspects of embodiments will become apparent and more readily appreciated from the following description, taken in conjunction with the accompanying drawings of which:
[0035] FIG. 1 is a cross-sectional view schematically illustrating a washing machine according to an embodiment;
[0036] FIG. 2 is an exploded perspective view schematically illustrating the washing machine according to embodiment;
[0037] FIG. 3 is a cross-sectional view schematically illustrating a rotating tub of the washing machine according to embodiment;
[0038] FIG. 4 is a cross-sectional view schematically illustrating a driving part and a waterproofing member of the washing machine according to embodiment;
[0039] FIG. 5 is an enlarged view of a portion “A” of FIG. 4 ; and
[0040] FIG. 6 is a view showing the flow of water during a washing operation and a spin-dry operation of the washing machine according to an embodiment.
DETAILED DESCRIPTION
[0041] Reference will now be made in detail to embodiments, examples of which are illustrated in the accompanying drawings, wherein like reference numerals refer to like elements throughout.
[0042] FIG. 1 is a cross-sectional view schematically illustrating a washing machine according to an embodiment.
[0043] Referring to FIG. 1 , a washing machine includes a body 1 forming an external appearance of the washing machine, a rotating tub 20 rotatably disposed inside the body 1 , and a driving part 100 disposed at a lower portion of the rotating tub 20 to rotate the rotating tub 20 .
[0044] The body 1 is provided at a upper portion thereof with a laundry input port 1 a , which allows laundry to be input into the rotating tub 20 therethrough, and with a door (not shown) configured to open and close the laundry input port 1 a.
[0045] The body 1 is provided at a lower portion thereof with a mounting part 2 having a leg 5 that enables the washing machine to be mounted on a floor.
[0046] The rotating tub 20 is rotatably disposed inside the body 1 . A plurality of drain holes 22 are formed at an upper portion of the rotating tub 20 along a circumference of the rotating tub 20 .
[0047] A pulsator 6 is rotatably installed at a bottom of the rotating tub 20 . The pulsator 6 serves to stir a washing water introduced into the rotating tub 20 together with a laundry.
[0048] A water supply apparatus 160 is installed at an upper side of the rotating tub 20 to supply a washing water to the rotating tub 20 . The water supply apparatus 160 includes a water supply valve 161 configured to regulate a supply of water and a water supply pipe 162 connecting the water supply valve 161 to a detergent supply apparatus 163 .
[0049] The water delivered through the water supply pipe 162 is supplied to the rotating tub 20 together with detergent by passing through the detergent supply apparatus 163 .
[0050] A first drain hose 231 and a second drain hose 230 are provided at the lower portion of the rotating tub 20 to guide a washing water, which has been used for a washing operation or a spin-dry operation, to the outside the body 1 .
[0051] The driving part 100 includes a clutch 120 , which rotates the rotating tub 20 and the pulsator 6 , and a driving motor 110 , which drives the clutch 120 .
[0052] The clutch 120 is connected to the driving motor 110 through a pulley 141 and a belt 142 such that a driving force of the driving motor 110 is selectively transferred to the rotating tub 20 or the pulsator 6 .
[0053] FIG. 2 is an exploded perspective view schematically illustrating the washing machine according to an embodiment. FIG. 3 is a cross-sectional view schematically illustrating a rotating tub of the washing machine according to an embodiment. FIG. 4 is a cross-sectional view schematically illustrating a driving part and a waterproofing member of the washing machine according to an embodiment.
[0054] Referring to FIGS. 2 to 4 , the rotating tub 20 is disposed inside the body 1 while being spaced apart from the inside the body 1 by a predetermined interval.
[0055] A suspension member 240 is installed on an outer side of the rotating tub 20 such that the rotating tub 20 is hung on the body 1 while being supported by the suspension 240 .
[0056] In order to support the rotating tub 20 , one side of the suspension member 240 is coupled to the upper portion of the body 1 and the other side of the suspension member 240 is coupled to a connecting bracket 241 of a base plate 200 that are to be described later.
[0057] The body 1 is provided at the lower portion thereof with the mounting part 2 that is configured to support the body 1 .
[0058] The mounting part 2 includes a bottom plate 3 forming the bottom of the body 1 and an installation hole 2 a formed through the center of the mounting part 2 in a predetermined diameter. The installation hole 2 a allows the driving part 100 to pass therethrough and then is installed on the mounting part 2 .
[0059] The bottom plate 3 has a first drain port 3 a that is connected to the first drain hose 231 to deliver the water discharged to the outside the rotating tub 20 during a spin-dry operation.
[0060] The first drain hose 231 is connected to the second drain hose 230 to discharge water passing through a second drain port 201 to the outside the body 1 during a washing operation and a rinsing operation.
[0061] The rotating tub 20 is rotatably provided on an upper side of the mounting plate 2 in a vertical direction.
[0062] The rotating tub 20 includes a bottom part 24 and a side wall 21 that connects to the bottom part 24 to form a space accommodating a washing water.
[0063] A through-hole 150 is provided in the center of the bottom part 24 to allow a driving shaft 124 to be coupled thereto. A liquid balancer 25 is provided at the upper portion of the rotating tub 20 to ensure the smooth rotation of the rotating tub 20 .
[0064] The side wall 21 is provided while being slanted with the increase of a diameter of the rotating tub 20 . If the rotating tub 20 rotates at a speed of 280 rpm or above in a spin-dry operation, water separated from the laundry reaches to the side wall 21 due to the centrifugal force and runs to the upper side of the rotating tub 20 along the inner side of the side wall 21 slanted.
[0065] In this case, the side wall 21 forms a slope angle θ of 2 degrees to 10 degrees with respect to a line (L) that is perpendicular to the bottom part 24 .
[0066] If the slope angle θ is smaller than 2 degrees, the water does not effectively move along the inner circumferential surface of the side wall 21 , and thus the spinning performance is degraded. If the slope angle θ is larger than 10 degrees, the upper portion of the rotating tub 20 is widened, and thus the overall width is increased.
[0067] As described above, a plurality of drain holes 22 are formed at the upper portion of the rotating tub 20 to discharge the water separated from the laundry to the outside the rotating tub 20 . The water discharged to the rotating tub 20 through the drain hole 22 flows to the bottom plate 3 of the mounting part 2 along an inner circumferential surface of the body 1 , and then is discharged to the outside through the first drain port 3 a and the first drain hose 231 .
[0068] The drain hole 22 is formed along the circumferential direction of the side wall 21 . The drain hole 22 is provided at a position corresponding to two-third of the height of the rotating tub 20 .
[0069] The driving part 100 is installed at the lower portion of the rotating tub 20 to drive the rotating tub 20 or the pulsator 6 disposed inside the rotating tub 20 .
[0070] The driving part 100 includes the clutch 120 , the driving motor 110 , a flange member 130 and the base plate 200 . The clutch 120 selectively rotates the rotating tub 20 and the pulsator 6 . The driving motor 110 drives the clutch 120 . The flange member 130 connects the driving shaft 124 of the clutch 120 to the bottom part 24 of the rotating tub 20 to transmit a torque of the driving shaft 124 to the rotating tub 20 . The base plate 200 is provided to fix the clutch 120 and the driving motor 110 (see FIGS. 1 , 4 , and 6 ).
[0071] Since the driving part 100 is fixed to a lower surface of the base plate 200 below the rotating tub 20 , the driving part 100 , after the spin-dry operation, may have a risk of being exposed to the water that runs down along the inner surface of the body 1 and then is discharged through the first drain port 3 a of the bottom plate 3 .
[0072] Accordingly, a waterproofing member 10 is provided between the base plate 200 and the bottom of the body 1 to seal the driving part 100 .
[0073] In addition, the mounting part 2 includes a moisture infiltration preventing guide 30 configured to prevent water from being introduced to (reaching) a plurality of cables (C) connected to electronic parts of the driving part 100 .
[0074] The moisture infiltration preventing guide 30 includes a cable accommodating part 30 a that allows the cable (C) to pass therealong. The moisture infiltration preventing guide 30 is provided in a direction perpendicular to edges of the bottom plate 3 of the mounting part 2 .
[0075] The waterproofing member 10 may include a diaphragm formed using elastically deformable material, such as rubber, to absorb the vibration of the driving part 100 .
[0076] Referring to FIGS. 4 and 5 , the waterproofing member 10 includes a plurality of wrinkled parts 11 and a fixing part 12 extending upward and downward.
[0077] The fixing part 12 includes a first fixing part 12 a extending upward from the wrinkled part 11 and a second fixing part 12 b extending downward from the wrinkled part 11 .
[0078] The waterproofing material 10 is provided in the form of a cylinder surrounding the outer side of the driving part 100 . The waterproofing material 10 is disposed between the base plate 200 and the bottom of the body 1 , that is, between the base plate 200 and the bottom plate 3 of the mounting part 2 .
[0079] The base plate 200 includes a first coupling part 202 having a coupling groove 202 a . The first coupling part 202 protrudes from the lower surface of the base plate 200 along the circumference of the base plate 200 while extending outward such that the coupling groove 202 a is coupled to the first fixing part 12 a of the waterproofing member 10 .
[0080] The first fixing part 12 a has an upper end which is bent outward to correspond to the coupling groove 202 a of the first coupling part 202 .
[0081] A wire 15 having a shape of a ring is configured to fasten the outer circumference of the first coupling part 202 of the base plate 200 and the first fixing part 12 a of the waterproofing member 10 , thereby allowing the first coupling part 202 to be closely fixed to the first fixing part 12 a.
[0082] The second fixing part 12 b of the waterproofing member 10 is coupled to a second coupling part 4 that is formed on the mounting part 2 .
[0083] The installation hole 2 a is provided in the center of the bottom plate 3 of the mounting part 2 . The second coupling part 4 is provided on the rim of the installation hole 2 a.
[0084] The second coupling part 4 extends downward from the bottom plate 3 . The second coupling part 4 is provided at an end thereof with a slanting part 4 a that extends while being slanted in a radial outward direction.
[0085] The second fixing part 12 b of the waterproofing member 10 has a shape corresponding to the shape of the second coupling part 4 such that the second fixing part 12 b is inserted into the second coupling part 4 . A wire 15 having a shape of a ring fastens the outer circumference of the second fixing part 12 b that is inserted to the second coupling part 4 , thereby allowing the second fixing part 12 b to be closely fixed to the second coupling part 4 .
[0086] The first coupling part 4 and the second coupling part 4 may be implemented in variety of shapes so that the fixing member 12 of the waterproofing member 10 can be firmly fixed to the first coupling part 202 and second coupling part 4 .
[0087] According to the above configuration, the waterproofing member 10 is provided between the base plate 200 and the bottom of the body 1 while surrounding the outer side of the driving part 100 to seal the driving part 100 and water is prevented from being infiltrated into (reaching) the driving part 100 , and the vibration of the driving part 100 is absorbed.
[0088] In addition, a vertical vibration is absorbed without impeding the rotation of the rotating tub 20 during the washing operation or the spin-off operation, thereby enhancing the washing efficiency.
[0089] When a draining process is viewed during the washing operation and the spin-off operation, a water (shown as a solid arrow line in FIG. 6 ) separated during the spin-off operation is discharged to the outer side of the rotating tub 20 through the drain hole 22 of the rotating tub 20 , flows downward along the inner surface of the body 1 , and then is discharged by sequentially passing through the first drain port 3 a formed through the bottom plate 3 , the first drain hose 231 and the second drain hose 230 connected to the first drain port 3 a.
[0090] The through-hole 150 of the rotating tub 20 is provided to allow the rotating tub 20 , the driving shaft 124 of the driving part 100 , and the flange member 130 to be coupled thereto. The through-hole 150 includes a first through-hole 151 , which is provided in the center of the through-hole 150 , and a second through-hole 152 disposed around the first through-hole 151 in the circumferential direction of the first through-hole 151 .
[0091] The first through-hole 151 is formed such that the driving shaft 124 is connected to the rotating tub 20 and the pulsator 6 by passing through the flange member 130 . The second through-hole 152 is formed to discharge water, which remains in the rotating tub 20 after the washing operation is finished, to the outside the rotating tub 20 through the second drain port 201 .
[0092] In addition, the driving shaft 124 includes a first driving shaft 124 a , which is coupled to the first through-hole 151 , and a second driving shaft 124 b , which extends from the first driving shaft 124 a and is coupled to the pulsator 6 .
[0093] The first driving shaft 124 a and the second driving shaft 124 b simultaneously or individually rotate depending on whether a washing operation is performed or a spin-off operation is performed.
[0094] In a washing operation, the second driving shaft 124 b operates to rotate the pulsator 6 that is coupled to the second driving shaft 124 b . During a spin-off operation, the first driving shaft 124 a and the second driving shaft 124 b operate such that the rotating tub 20 and the pulsator 6 simultaneously rotate.
[0095] One end of the driving shaft 124 is connected to the pulley 141 such that a driving force of the driving motor 110 is transferred to the clutch 120 .
[0096] In addition, the base plate 200 has a base plate cover 210 to guide water discharged through the second through-hole 152 .
[0097] The base plate cover 210 is disposed between the flange member 130 and the base plate 200 to house the second drain port 201 that is formed on the base plate 200 .
[0098] A drain case 220 is coupled to a lower portion of the base plate 200 to form a predetermined space. The space is configured to accommodate a washing water that is introduced by passing through a space formed between the base plate cover 210 and the base plate 200 .
[0099] One end of the drain case 220 is connected to the second drain hose 230 to guide a washing water introduced to the drain case 220 to the outside the body 1 .
[0100] A valve 221 is provided on the second drain hose 230 to selectively drain water.
[0101] In this manner, the water having been used for the washing operation or the rinsing operation (shown as a dotted line arrow in FIG. 6 ) is introduced into the space between the base plate cover 210 and the base plate 200 by passing through the second through hole 152 and then is discharged to the outside the body 1 by sequentially passing through the drain case 220 and the second drain hose 230 .
[0102] In each of the washing operation, the rinsing operation and the spin-off operation, the driving part 100 provided at the lower portion of the rotating tub 20 is completely sealed by the waterproofing member 10 provided between the base plate 200 and the bottom plate 3 of the body 1 , thereby preventing water from being infiltrated into (reaching) the driving part 100 .
[0103] In addition, the cable (C) connected to the driving part 100 is also prevented from being exposed to water by the cable accommodation part 30 a formed on the bottom plate 3 .
[0104] In addition, the waterproofing member 10 surrounds the outer side of the driving part 100 , thereby preventing vibration and noise from the driving part 100 .
[0105] As described above, a structure to accommodate water between the body 1 and the rotating tub 20 is removed, so that the spatial utilization in the body 1 is maximized. In addition, the waterproofing member 10 provided at the lower portion of the rotating tub 20 serves to absorb the up-and-down vibration of the rotating tub 20 and the vibration of the driving part 100 and also prevents the water from being introduced to the electronic parts of the driving part 100 .
[0106] Although a few embodiments have been shown and described, it would be appreciated by those skilled in the art that changes may be made in these embodiments without departing from the principles and spirit of the disclosure, the scope of which is defined in the claims and their equivalents. | A washing machine capable of increasing the washing capacity without enlarging the external appearance and also discharging a washing water during a washing operation or a spin-dry operation while completely isolated from electronic parts and thus reducing the risk of a power failure and fire, the washing machine including a body, a rotating tub rotatably disposed inside the body, a pulsator rotatably disposed inside the rotating tub, a driving part provided on a lower portion of the rotating tub to selectively rotate the rotating tub and the pulsator, a base plate to which the driving part is fixed, wherein a waterproofing member is provided between the base plate and a bottom of the body to seal the driving part and to prevent water from reaching the driving part. | 3 |
CROSS-REFERENCE TO RELATED APPLICATION
The present application is a continuation-in-part application of U.S. patent application Ser. No. 11/331,966, filed Jan.13, 2006 now U.S. Pat. No. 8,002,695 and the present application claims priority to U.S. provisional application No. 60/771,671, filed Feb.9, 2006, the contents of which are incorporated herein by reference.
BACKGROUND OF THE INVENTION
1. Field of the Invention
The present invention relates to a medical retainer and, in particular, to a medical retainer capable of independently controlling the supply of air and water to hollow organs such as a stomach and a lumen of a small intestine. Also, the present invention relates to a medical operation using the medical retainer.
2. Description of the Related Art
Laparoscopic instruments are routinely used to perform surgery on organs accessible via the abdominal cavity. In order to perform such surgery, it is necessary to expand the space within the lumen of abdominal cavity to allow for the observation of abdominal organs and the manipulation of laparoscopic surgical instruments. A common method of expanding the lumen of the abdominal cavity is to insufflate this space with pressurized gas. Air, carbon dioxide and nitrous oxide have all been used. The insufflation of gas into the space of the abdominal cavity separates the patient's abdominal wall from the organs beneath it, thus creating a working space between the abdominal wall and the organs within the abdominal cavity.
Transgastric endoscopic procedures are being developed as an alternative endoscopic means of operating within the lumen of the abdominal cavity. With this surgical approach, a flexible endoscope is passed through the patient's mouth and esophagus into the patient's stomach. An incision or opening is then made in the wall of the stomach, through which the endoscope may be passed out of the stomach into the abdominal cavity. Instruments passed through this transgastrically placed endoscope are then able to perform surgery on abdominal organs in a manner similar to laparoscopic instrumentation.
A current problem of transgastric endoscopic procedures is the inability to independently control insufflation of the stomach, the small intestine, and the lumen of the abdominal cavity.
When the endoscopic procedure is first started, it is desirable to insufflate the stomach in order to expand it, to flatten out the folds of the stomach and to create a working space within the stomach. A clear view of the stomach wall and a substantial working space within the stomach is necessary to facilitate the next step, which is to endoscopically incise the wall of the stomach. The purpose of creating an incision in the wall of the stomach is to create an opening that will allow the distal end of the endoscope to pass from the stomach into the abdominal cavity.
Once the endoscope enters the abdominal cavity, it is desirable to contract the stomach and insufflate the abdominal cavity. Insufflating the abdominal cavity creates a large working space for the flexible endoscope to observe and perform surgery on the abdominal organs. After entering the lumen of the abdominal cavity, it is advantageous to remove the excess gas previously added to the stomach in order to reduce the size of the stomach, and thereby reduce its protrusion into the lumen of the abdominal cavity. In addition, since the stomach communicates with the small intestine via the pylorus, pressurized gas within the stomach will flow into the small intestine, pressurizing the intestines as well. The gas flowing into the small intestine will expand the intestines, causing them to project into the abdominal cavity, further reducing the available working space within the abdominal cavity.
SUMMARY OF THE INVENTION
It is an object of the present invention to use a balloon device placed within the lumen of the proximal small intestine to prevent gas from flowing into and inflating the small intestine during transgastric endoscopic procedures. It is a further object of the present invention to provide a means of removing gas from the distal end of the balloon-obstructed small intestine to further lower its inflated state. It is a further objective of the present invention to provide detachable catheters to this balloon device so that once the balloon is inflated and the small intestine decompressed, the device can be anchored to the wall of the GI tract and the tubes connected to the device can be removed from the patient.
Another object of the present invention is to provide a method that enables easier confirmation of a specific site on a hollow organ, by using an observation device that has been guided into the hollow organ. The present invention further provides a device for this method.
A first aspect of the present invention provides a medical retainer for sealing a fluid so that the retainer is subject to be retained in a gastrointestinal tract of a patient. The medical retainer comprises: a sealing section for sealing the fluid, the sealing section making contact with a wall of the gastrointestinal tract; a main body having passageways; and directional valves disposed in the passageways for allowing one of upward flow and downward flow of the fluid relative to the position of the retainer.
A second aspect of the present invention provides a medical operation via a natural orifice. The method includes: adjusting the patient's body position so that a target site on the anterior wall of the hollow organ faces in the direction opposite to the direction of gravitational force; introducing a liquid inflow conduit in the vicinity of the target site, flowing liquid into the hollow organ via the liquid inflow conduit, to form a liquid holding area and a gas retaining area inside the hollow organ; introducing an observation device into the hollow organ, and confirming the position of the target site from the position of the gas retaining area; and incising while observation the target area.
A third aspect of the present invention provides a medical operation via a natural orifice. The procedure includes: adjusting the patient's body position so that the target site on the anterior wall of the hollow organ faces in the direction opposite to the direction of gravitational force; introducing a liquid inflow conduit in the vicinity of the target site via a natural orifice; flowing a liquid into the hollow organ via the liquid inflow conduit, to form a liquid holding area and a gas retaining area inside the hollow organ; confirming the position of the gas retaining area by using an observation device introduced into the hollow organ via the natural orifice, and confirming the target site based on the position of the gas retaining area; and performing a procedure at the target site while observation the target site.
BRIEF DESCRIPTION OF THE DRAWINGS
FIG. 1 illustrates an endoscope passing through the mouth and esophagus into the stomach in a side-sectional schematic view of the human torso.
FIG. 2 is a side-sectional schematic view of the human torso illustrating an endoscope employing a needle electrode at its distal tip to make an incision in the wall of the stomach.
FIG. 3 is an anterior sectional schematic view of the human lower esophagus, stomach and small intestine in the vicinity thereof. An endoscope passed into the stomach with a needle-tipped electrode is being used to create an incision in the wall of the stomach.
FIG. 4 is a side-sectional schematic view of the human torso with an endoscope passing through an incision in the wall of the stomach and entering the abdominal cavity.
FIG. 5 is a side-sectional schematic view of the human torso with an endoscope passing through an incision in the wall of the stomach and entering the abdominal cavity. As compared with FIG. 4 , this figure illustrates that expansion of the stomach and small intestines reduces the size of the lumen of the abdominal cavity.
FIG. 6A is an isometric view of a first embodiment of the present invention. The balloon is disposed beyond the pylorus in the proximal small intestine. The proximal end of the catheter and the balloon inflation tube are disposed in the exterior of the patient.
FIG. 6B illustrates a sectional view of the catheter and balloon inflation tube as taken along line A-A in FIG. 6 .
FIG. 7A is an isometric view of a second embodiment of the present invention. The balloon is disposed beyond the pylorus in the proximal small intestine. The proximal end of the catheter and the balloon inflation tube are disposed in the exterior of the patient.
FIG. 7B is a view of the second embodiment of the device after detaching and removing the proximal portions of the catheter and balloon inflation tube.
FIG. 8 is an isometric view of a third embodiment of the present invention. The catheter has been disconnected from the balloon hub. A one-way valve is incorporated into the balloon hub.
FIG. 9 is a schematic view of the third embodiment of the device illustrating that the balloon is disposed in the patient's small intestine and the balloon inflation tube extends up the esophagus and out of the patient. The catheter has been disconnected from the balloon hub.
FIG. 10 is an isometric view of the same embodiment as illustrated in FIG. 8 . In this illustration a portion of the balloon hub has been cut away for a more complete view of the one-way valve incorporated into the hub.
FIG. 11 is a side-sectional view of the balloon and balloon hub of the third embodiment of the device. In this illustration the catheter is attached to the hub.
FIG. 12 is a side-sectional view of the balloon and balloon hub of the third embodiment. In this illustration the catheter has been detached from the hub.
FIG. 13 is a side-sectional view of the balloon and balloon hub of the third embodiment. This illustration shows a means for reattaching the catheter to the hub.
FIG. 14 is an isometric schematic view of a fourth embodiment of the present invention. In this anterior view of the stomach and proximal small intestine, a portion of the tissue has been cut away to illustrate the position of the device within the proximal small intestine. The catheter has been detached. The balloon inflation tube has been endoscopically cut near the one-way valve.
FIG. 15 is an isometric schematic view of a fifth embodiment of the present invention. This embodiment has a fixation loop by which the balloon hub can be anchored in place by means of an endoscopically placed tissue clip.
FIG. 16 is an isometric schematic view of a sixth embodiment of the present invention. In this embodiment the lumen of the proximal small intestine is obstructed by a self-expanding closed-cell foam plug. The plug is contained in a wire basket, the handle of which extends outside the patient.
FIG. 17 illustrates the device shown in FIG. 16 , but with the basket tightened and compressing the foam plug to reduce its size. In this configuration the device can be easily inserted into or withdrawn from the patient.
FIG. 18 is a view showing an endoscope employed in the seventh embodiment, as one example of a device used in a medical operation.
FIG. 19 is a flow diagram showing a medical operation according to the second embodiment.
FIG. 20 is a view for explaining the arrangement for inserting the endoscope into the stomach, in a procedure according to the seventh embodiment.
FIG. 21 is a view for explaining the arrangement for sending water by inserting an endoscope into the stomach, in a procedure according to the seventh embodiment.
FIG. 22 is a view for explaining the arrangement in which the insertion part of the endoscope has been directed to the gas retaining area, in a procedure according to the seventh embodiment.
FIG. 23 is a view for explaining the arrangement for marking the target site, in a procedure according to the seventh embodiment.
FIG. 24 is a view for explaining the arrangement for an insufflation, in a procedure according to the seventh embodiment.
FIG. 25 is a view for explaining the state in which an opening has been incised in the stomach, in a procedure according to the seventh embodiment.
FIG. 26 is a flow diagram showing a medical operation according to the seventh embodiment.
FIG. 27 is a view for explaining the arrangement in which water is supplied into the stomach to inflate it, in a procedure according to an eighth embodiment.
FIG. 28 is a view for explaining the arrangement for confirming the direction of movement of bubbles using the insertion part of the endoscope, in a procedure according to the eighth embodiment.
DETAILED DESCRIPTION OF THE INVENTION
Embodiments will be hereafter explained in detail. In the following description, the same reference symbols are used for the same components, and duplicate description is omitted.
FIG. 1 illustrates a flexible endoscope 1 passed through the patient's oropharynx 18 and esophagus 2 and into the stomach 3 . Once in the stomach, the endoscope is used to create an incision in the wall of the stomach in order to gain entrance into the lumen 6 of the abdominal cavity. FIG. 2 illustrates that one method of incising the stomach is to use a needle electrode 20 passed through the endoscope 1 to cut an opening in the stomach wall using RF (radio frequency) electrosurgical current. This opening will allow the endoscope to enter the abdominal cavity 6 .
FIG. 3 illustrates the same procedure from another point of view, namely looking at the esophagus, stomach and proximal small intestine from an anterior view of the patient. A needle electrode 20 exiting from the tip of the endoscope 1 is being used to create an incision in the wall of the stomach 3 . During this procedure it is typical for the endoscopist to inject gas or air through the endoscope into the stomach to expand the stomach for ease of observation and manipulation of the endoscope and endoscopic therapy device. It should be noted however, that the air within the stomach 3 is able to flow through the pylorus 4 and into the proximal small intestine 5 , thereby expanding the intestines as well as the stomach.
As FIG. 4 illustrates, once an incision 19 is made in the stomach wall, the endoscope 1 is passed into the lumen 6 of the abdominal cavity. By injecting gas through the endoscope, gas can be added to the abdominal cavity raising the abdominal wall 17 from the underlying organs, thereby creating a large working space for the endoscope.
However, as FIG. 5 illustrates, the size of the lumen 6 of the abdominal cavity will be greatly reduced if the stomach 3 and intestines 5 are also filled with gas. When these organs are filled with gas they expand, impinging on the available space within the lumen of the abdominal cavity, thereby reducing the available working space for manipulating the endoscope and for performing surgery on the abdominal organs.
It is an objective of the present invention to describe a balloon device that can be placed in the pylorus or proximal small intestine to obstruct the passage of gas from the stomach into the small intestine, and thereby allow the small intestine to remain decompressed as the stomach is filled with gas. It is another object of the present invention to provide a means of suctioning the gas that is trapped within the intestines after the balloon is inflated in order to remove this gas, reduce the size of the intestines, and thereby reduce their protrusion into the lumen of the abdominal cavity. It is a further objective of the present invention to allow detachment of the catheter of the balloon to prevent the balloon's catheter from occupying space within the patient's esophagus. It is another object of the present invention to temporarily attach the balloon to the wall of the stomach or pylorus to prevent it from migrating or moving out of position after its placement. Reference numeral 19 shown in FIGS. 4 and 5 indicates an opening formed in the wall of the stomach.
FIG. 6A illustrates an embodiment of the gas-control balloon of the present invention. The balloon 7 is mounted on the tip of a catheter 8 that is long enough to be inserted into the patient through the mouth, esophagus 2 and stomach 3 and into or beyond the pylorus 4 . The balloon and catheter are inserted into position with the balloon deflated using traditional means for inserting medical balloon-tipped catheters. Upon placement of the balloon 7 near or past the pylorus 4 , the balloon is inflated by injecting gas into the balloon inflation connector 11 . When the balloon is expanded so that the surface of the balloon is in full contact with the wall of the pylorus and/or intestine, it will obstruct the further flow of gas from the stomach 3 into the small intestine 5 , and vice versa.
When the balloon is thus positioned and inflated, it is possible to apply suction to the catheter by connecting a syringe or pump to the proximal catheter connector 10 . This will withdraw gas from the small intestine 5 through the catheter opening 12 distal to the balloon. Removing gas from the small intestine will reduce its size and increase the available space within the abdominal cavity.
FIG. 6B is a cross-section of the catheter illustrated in FIG. 6A through line A-A. It illustrates that the catheter has a first lumen 13 for suctioning gas from the catheter opening ( 12 in FIG. 6 ) and a second lumen 14 for inflating/deflating the balloon 7 on the distal end of the catheter.
FIG. 7A illustrates a second embodiment of the present invention. In the present embodiment, the catheter 8 is detachable from the balloon tip 7 . The catheter is initially placed and the balloon is inflated near or beyond the pylorus in a manner similar to the first embodiment illustrated in FIG. 6A . After the catheter is placed, gas is withdrawn from the small intestine 5 by applying suction to the catheter connector 10 . This will decompress the small intestine, thereby reducing its size.
Once the small intestine has been decompressed it is beneficial to have the capability of removing the catheter from the balloon. The advantage of removing the catheter is that this will leave the stomach and esophagus free for the passage of endoscopes and other devices.
A one-way valve and detachable connector 41 are disposed in the catheter between its distal end 43 and proximal portion 42 . The one-way valve allows gas to flow through the catheter only in the direction from a central lumen (not shown) in the catheter hub 47 to the catheter connector 10 . This allows decompression of the small intestine 5 . The detachable connector 41 allows the proximal part 42 the catheter to be separated from the distal part 43 of the catheter. Likewise, a valve and detachable connector 44 are incorporated in the balloon inflation tube 9 between the distal part of the tube 46 and a more proximal part of the tube 45 . This detachable connector 44 allows the proximal part of the inflation tube 45 to be separated from the distal part 46 of the tube connected to the balloon 7 . When these two tubes are disconnected, the valve in the detachable connector 44 prevents gas from escaping from the distal inflation tube 46 , thereby preventing deflation of the balloon 7 .
After positioning the balloon at or beyond the pylorus, the balloon 7 is inflated. Then suction is applied to the catheter connector 10 to decompress the small intestine. At this point, the two tubes connected to the balloon device can be disconnected and removed from the patient. The resulting configuration is illustrated in FIG. 7A .
In this condition, gas in the stomach is prevented by the balloon obstructing the pylorus, and by the one-way valve 41 obstructing flow through the central lumen in the balloon hub 47 from entering the small intestine. The stomach can thus be reinflated without reinflating the small intestine.
FIG. 8 illustrates an embodiment of the invention in which the detachable connection and one-way valve have been incorporated into the balloon hub itself. The embodiment shown in FIG. 8 has a balloon 22 that is inflated by means of an inflation tube 27 . A suction catheter 26 connects to the balloon hub 23 via a detachable connector 25 . A one-way valve 24 incorporated into the balloon hub 23 allows the flow of gas through a central lumen (not shown) within the hub into the suction catheter 26 , but not in the reverse direction. After the balloon catheter has been placed in the pylorus and inflated, gas can be withdrawn from the small intestine by applying suction to the suction catheter. After the small intestine is decompressed, a tug on the suction catheter will detach it from the balloon hub, allowing the catheter to be withdrawn from the patient while leaving the balloon in place in the pylorus. The one-way valve 24 in the hub prevents gas in the stomach from flowing through the lumen in the hub and reinflating the small intestine. As FIG. 9 illustrates, after removing the suction catheter ( 26 in FIG. 8 ) the thin balloon inflation tube 27 remains in the patient's esophagus allowing subsequent deflation of the balloon and removal of the device from the patient.
FIG. 10 shows a cut-away view of the hub 23 providing a clearer view of the one-way valve 24 in the device.
FIG. 11 is a cross-sectional view of the embodiment illustrated in FIG. 8 prior to detaching the suction catheter from the hub. The expandable balloon 22 is attached to the hub 23 via adhesive 28 , thread wrapping, or other means of attachment. Inflation and deflation of the balloon is achieved by injecting or removing gas, respectively, via the balloon inflation tube 27 . Removal of gas distal to the device is achieving by suctioning gas through the central lumen 37 in the hub and then up the lumen of the suction catheter 26 . A one-way valve 24 incorporated into the hub is held in an open position by a tubular protruding part 31 on the detachable connector 25 which connects the suction catheter 26 to the balloon hub 23 . When in this condition there is a free flow of gas through the device. A tapered friction fit between the mating surfaces 30 of the detachable connector 25 and the hub 23 keeps these two pieces together. However, as FIG. 12 illustrates, a slight tug on the suction catheter 26 will detach the detachable connector 25 from the hub 23 . When this happens, the one-way valve 24 incorporated into the hub automatically closes. This valve will allow gas to flow only in the direction of the arrow—that is, from the small intestine into the stomach, not vice versa.
FIG. 13 illustrates how the parts of the device are assembled prior to placing them into the patient. A valve opening tube 29 is first inserted through the central lumen of the hub 23 . This tube opens the one-way valve 24 allowing the tubular protruding part 31 of the detachable connector 25 to pass through the one-way valve 24 . The pieces are brought together until the mating surfaces of the hub and the detachable connector engage with a friction fit to hold the two pieces together. Once assembled, the valve opening tube 29 is removed and the device is assembled and is in the condition illustrated in FIG. 11 .
FIG. 14 illustrates an alternative embodiment of the present invention. In this embodiment a one-way valve 32 has also been incorporated into the balloon inflation tube 27 . After placing the balloon device at or beyond the pylorus 4 , the balloon 22 is inflated and the suction catheter is detached. The one-way valve 24 in the balloon hub allows gas in the small intestine 5 to flow through the device into the stomach 3 , but prevents gas from flowing from the stomach into the small intestine. Once the balloon has been inflated to the proper size, endoscopic scissors or other endoscopically employed cutting devices are used to cut the thin balloon inflation tube 27 at a point proximal 33 to the one-way valve 32 in the inflation tube. Since the one-way valve 32 allows air to be supplied to the balloon and prevents the air from flowing out of the balloon, the gas will never flow from the stomach to the small intestine. After the procedure is completed, an endoscopic needle can be used to puncture the balloon and the balloon device is endoscopically removed from the patient.
FIG. 15 illustrates a further modification to the embodiment illustrated in FIG. 14 . In this embodiment a fixation loop 35 is firmly attached to the balloon hub 23 . Once the balloon is correctly positioned, the fixation loop is temporarily attached to the mucosal surface of the stomach or pylorus by means of an endoscopically applied clip 36 or suture. This temporarily anchors the balloon device and prevents it from migrating further into the small intestine 5 . When the procedure is completed, the clip or suture is removed, allowing removal of the balloon device from the patient.
FIG. 16 illustrates a further alternative embodiment of the present invention. In this embodiment a plug of closed-cell foam 34 is constructed of a size and shape that will obstruct gas flow between the stomach 3 and the small intestine 5 . The foam plug is loosely held in a thin wire basket 38 attached to the end of a control catheter 39 . A handle 40 at the proximal end of the control catheter allows the operator to open and close the basket at will. When the basket is opened (expanded) as shown in FIG. 16 , the self-expanding foam plug automatically expands to touch the walls of the intestine and obstruct gas flow between the stomach and the intestines. The closed-cell construction of the foam prevents gas from flowing through the foam plug. The thin catheter 39 attached to the basket remains in the patient during the procedure, preventing migration of the plug and enabling its removal.
FIG. 17 illustrates how the device shown in FIG. 16 is inserted and removed. Operating the handle 40 at the proximal end of the control catheter 39 closes the wire basket 38 holding the foam plug 34 thereby compressing the plug and greatly reducing its size. When the plug compressed it can be easily inserted or withdrawn from the patient.
Embodiments according to the present invention will now be explained in detail below. Structural elements that are equivalent in the following discussion will be assigned the same numeric symbol and redundant explanation thereof will be omitted.
[Seventh Embodiment]
A flexible endoscope (referred to as “endoscope” hereinafter) 101 is shown in FIG. 18 as an example of a device employed in the present embodiment. The endoscope 101 is provided with an elongated insertion part 103 that extends out from an operation part 102 , which is manipulated by the operator. An insertion part 103 has flexibility, and is inserted into the patient's body. The end 105 of the insertion part 103 can be bent by operating an angle knob 106 that is disposed to the operation part 102 . An observation device (alternatively referred to as “observation device”) 107 , composed of an optical system for observation such as an objective lens or the like, and a CCD, used as an image pick-up element; an illuminating device 109 composed of an optical fiber for guiding light from a light source device 108 disposed outside the body, and an illuminating optical member for forming the light rays radiated from the end surface of the optical fiber into a desired form; and the end openings for channels 110 and 111 ; are disposed to the end of the insertion part 103 . The channel 110 is a conduit that is connected to a gas/water supplying device 113 that is disposed outside the body, via a universal cable 112 , and that is employed for supplying and evacuating liquid to and from the body. The channel 111 is a conduit that is attached to a suction device 115 or that is employed for inserting and removing instruments. The observed image that is input to the observation device 107 is displayed on a monitor 117 via a controller 116 .
The effects of the present embodiment in which this endoscope 101 is employed will be explained following the flow diagram shown in FIG. 19 . Note that the following discussion explains a procedure in which the endoscope 101 , which is an example of a procedure device for performing a specific procedure, is inserted via the mouth M of a patient PT into the stomach (hollow organ) ST, an opening is formed in the stomach wall, the insertion part 103 of the endoscope 101 is inserted into the abdominal cavity AC, and a procedure is performed. Note that in this case, the natural orifice into which the endoscope 101 is inserted is not limited to the mouth M; rather, this explanation is applicable to the nostrils, anus, or any other natural orifice. With regard to the medical operation carried out in the abdominal cavity AC, a variety of procedures, such as suturing, observation, incising, resection, cellular sampling, removal of a body organ or the like, may be carried out alone or in combination.
First, in body position adjusting step (S 10 ), the body position of the patient PT is adjusted so that a target site T on the anterior wall of the stomach ST faces in the direction opposite the direction of gravitational force. In this embodiment, an arrangement is employed in which the patient PT is placed on his/her back, so that the anterior wall of the stomach ST, where the target site T is located, is directed upward.
Next, guiding step (S 20 ), in which the endoscope 101 is inserted into the stomach ST, is carried out. Namely, a mouth piece 118 is attached at the mouth of the patient PT, and the endoscope 101 is inserted into the esophagus ES. It is preferable here to incorporate an overtube 120 during insertion of the endoscope into the body, as shown in FIG. 20 . The overtube 120 is employed as a guide tube for inserting the endoscope 101 or another such device having an insertion part. However, it is also acceptable to directly insert the endoscope 1 without employing the overtube 120 .
In the case where inserting the endoscope using the overtube 120 , an attaching balloon (sealing member) 121 is attached at the distal end of the overtube 120 . As shown in FIG. 20 , the overtube 120 and the end of the insertion part 103 of the endoscope 101 are inserted into the stomach ST.
Next, the process proceeds to the area forming step (S 30 ). A sealing step (S 31 ) is first carried out in which the outlet side of the stomach ST (i.e., the forward direction of insertion of the endoscope) near the target site T (anterior wall of the stomach in this embodiment) is sealed. Specifically, an instrument is inserted into channel 111 of the endoscope 101 , and a retaining balloon (sealing member) 122 is disposed in the duodenum Du in the forward direction of insertion of the endoscope 101 . This retaining balloon 122 is then inflated in this position. The instrument is then removed, so that the retaining balloon 122 remains and seals the pylorus PS of the stomach ST. Sealing of the inlet side (i.e., the cardia CS side) of the stomach ST is then performed. Specifically, the attaching balloon 121 provided to the overtube 120 is inflated, sealing the space between the overtube 120 and the cardia CS. The space formed between the inner surface of the overtube 120 and the surface of a device such as the endoscope 101 that is inserted therein is sealed with a sealing member such as a valve, not shown in the figures, that is provided to the overtube 120 . Note that, in this embodiment, both sides of the stomach ST (i.e., the one side and the other side of the hollow organ that have the area of the target site disposed therebetween) are sealed using sealing members such as attaching balloon 121 and the retaining balloon 122 . However, it is also acceptable to omit sealing of the inlet side (i.e., the side into which the endoscope 101 or the overtube 120 is inserted) of the stomach ST. This is because in the case of the inlet side of the stomach ST, seal-tightness of the hollow organ can be assured to a certain degree by means of the inserted device such as the endoscope 101 or the overtube 120 , as compared to the outlet side (i.e., the cardia CS side or the forward direction of insertion of the endoscope 101 ) of the stomach ST.
Next, the process proceeds to the liquid inflow step (S 32 ). In this step, water is supplied into the stomach ST from channel 111 of the endoscope 101 which has been introduced into the stomach ST. Since both the cardia CS and the pylorus PS of the stomach ST are sealed at this time, water is held in the stomach ST as shown in FIG. 22 . Since water W is heavier than air A, the water W supplied into the stomach ST is held in the bottom portion of the stomach ST, while air A rises to the top of the stomach ST. The target site T is positioned at the top of the stomach ST, where it is not dipped in water. In this way, a lower liquid holding area LA, and an upper gas retaining area GA, where gas remains and where the target site T is located, are formed.
The process then proceeds on to detecting step (S 40 ). In this step, the angle knob 106 is operated to bend and manipulate the end of the insertion part 103 inside the stomach ST. The position of gas retaining area GA is confirmed during this operation, and the end of the insertion part 103 is moved from liquid holding area LA to gas retaining area GA. In this way, target incision site T is confirmed using the observation device 107 , as shown in FIG. 23 .
Next, in marking step (S 50 ), a the marking instrument 123 such as a high frequency knife, used for marking the stomach wall, is inserted into the channel 111 of the insertion part 103 , and marking near the target site T is carried out as shown in FIG. 24 . In order to prevent a short circuit, note that it is first confirmed that the area around the marking site is completely within gas retaining area GA. It is also acceptable to carry out this marking using a retained member, such as a clip or the like.
Once marking is completed, removing step (S 60 ) is carried out. Namely, the marking instrument 123 is withdrawn from the channel 111 , and the channel 111 and the suction device 113 are connected. The suction device 113 is then activated to remove the water W remaining in the stomach ST, expelling it to the outside of the body via the channel 111 of the endoscope 101 .
The process then proceeds to incising step (S 70 ). The end of an insufflation needle (a conduit for supplying gas) 125 is passed from outside the body through an abdominal wall AW, and into the abdominal cavity AC, as shown in FIG. 25 , for example. The abdominal cavity AC is then inflated with gas via the insufflation needle 125 , to create a space between the stomach wall and the abdominal wall AW. In this embodiment, space between the stomach wall and the abdominal wall AW is secured by insufflating the abdominal cavity AC; however, it is not absolutely essential to carry out an insufflation step. Namely, it is also acceptable to employ conventionally known methods such as the suspension method to provide this space. In addition, it is also acceptable to perform the insufflating step in advance of the incising step. In addition, insufflation of the hollow organ is not absolutely required.
Next, the marking instrument 123 disposed inside the channel 111 is removed, and a high frequency knife for cutting is passed in its place through the channel 111 to extend out from the end opening. The marked target site T is then incised while observation the target site T on the monitor 117 , to form an opening SO in the stomach wall (at a position corresponding to the target site T), the opening SO creating a communication between the inside of the stomach ST and the abdominal cavity AC. Note that a combined use instrument may be employed for the marking instrument and the instrument for forming the opening SO.
After incising, as shown in FIG. 26 , the end of the insertion part 103 is projected out into the abdominal cavity AC through the opening SO in the stomach wall, and procedure step (S 80 ) is carried out in which various procedures such as suturing, observation, incising, resection, cell collection, organ removal or the like, are performed.
Next, the process proceeds to suturing step (S 90 ), in which the opening SO in the stomach wall is sutured closed (the communicating path between the inside of the hollow organ and the abdominal cavity is closed) with a suturing instrument while using the observation device 107 of the endoscope 1 for confirmation.
After suturing, the endoscope 101 is withdrawn from the patient. In the case where the medical operation was performed by blowing carbon dioxide gas or the like into the abdominal cavity AC in order to secure space within the abdominal cavity, it is desirable to withdraw the insufflation needle 125 after first relieving the pressure within the abdominal cavity AC, and then conclude the medical operation.
In this embodiment, water was supplied into the stomach ST after positioning the patient PT so that the target site T is on top. As a result, by searching for the gas retaining area (GA) inside the stomach ST, it is possible to confirm the up/down direction from inside the stomach ST, and the target site T can be gripped. The stomach ST is sealed using attaching balloon 121 and the retaining balloon 122 during this operation. As a result, it is possible to grip the target site T by sending and expelling water to and from the stomach ST using the devices of a conventional endoscope 101 , without requiring use of special equipment.
Since an incision is made in the anterior wall of the stomach ST, it is easy to avoid the greater omentum or other organs when introducing the endoscope into the abdominal cavity AC. As a result, the endoscope 101 can be readily inserted into the abdominal cavity AC, further facilitating the procedure.
In the past, it has been difficult to specify the direction or the location for a procedure (i.e. the location suitable for forming an opening) by means of the endoscope image alone, and practice was required for this procedure. However, in this embodiment, confirmation of the site is facilitated, reducing the burden on the operator.
In the seventh embodiment described above, the channel 110 is employed as a conduit for supplying water, and the channel 111 has a combined use as a conduit for inserting and passing instruments and as a conduit for expelling water. As another example, however, it is also acceptable to provide a combined use water supplying conduit and instrument inserting and passing conduit. In addition, a design is also acceptable in which the three functions of supplying water, expelling water, and instrument inserting/passing are accomplished by means of a single conduit. In addition, the hollow organ anterior and posterior to the target site were sealed using a sealing member, however, when it is possible to determine the direction of gravitational force and the direction opposite that using just a small amount of water, then it is not absolutely essential to carry out the sealing step.
[Eighth Embodiment]
An eighth embodiment will now be explained with reference to the figures.
The difference between the seventh and eighth embodiments is that, in this embodiment, the stomach ST is inflated with water, after which air is introduced into the stomach ST, and the target site T is searched for using the direction of movement of the air bubbles.
The effects of this embodiment will be explained following the flow shown in FIG. 26
First, the body position adjusting step (S 10 ) and introducing step (S 20 ) are carried out in the same manner as in the seventh embodiment. Namely, the position of the patient PT is adjusted so that the target site T is directed upward, and the overtube 120 and the endoscope 101 are inserted into the stomach ST.
Next, the process proceeds to area forming step (S 100 ). First, sealing step (S 31 ) is carried out, in which the retaining balloon 122 is retained in duodenum Du. In this way, the pylorus PS of the stomach ST and the cardia CS of the stomach ST are sealed.
Next, the process proceeds to liquid inflow step (S 102 ). As shown in FIG. 27 , water is supplied into the stomach ST via the channel 111 of the endoscope 101 which has been inserted into the stomach ST, inflating the stomach ST with water W. Once the stomach ST is inflated, the process proceeds to gas inflow step (S 103 ). Namely, air A is introduced into the stomach ST from an air/water supplying device 113 via the channel 110 of the endoscope 101 . Since air A is lighter than water W, the air A introduced into the stomach ST forms bubbles B and moves through water W to the top of the stomach ST, as shown in FIG. 28 . In this way, a liquid holding area LA is formed at the bottom and a gas retaining area GA, where the air remains, is formed at the top within the stomach ST.
Direction recognition step (S 104 ) is executed almost simultaneously. Namely, the movement behavior of bubbles B from air A expelled from the end of the insertion part 103 of the endoscope 101 in gas inflow step (S 103 ) is observed, thereby allowing determination of the up/down direction within the stomach ST (alternatively, the up/down direction in the stomach ST may be determined by determining the direction where gas retaining area GA is formed).
The process then proceeds on to detecting step (S 110 ). The end of the insertion part 103 is moved from liquid holding area LA to gas retaining area GA while being bent and manipulated by operating the angle knob 106 .
Subsequently, the marking step (S 50 ), removing step (S 60 ), incising step (S 70 ), procedure step (S 80 ), and suturing step (S 90 ) are each executed in the same manner as in the seventh embodiment. After suturing is completed, the endoscope 101 is removed from the patient, the insufflation needle 125 is removed after relieving the pressure inside the abdominal cavity AC, and the procedure is terminated.
In this embodiment, the up/down direction in the stomach ST was determined by observing bubbles B moving through water W. As a result, gas retaining area GA can be recognized more easily than in the first embodiment, and searching for the target site T is facilitated. Note that in the second embodiment, the channel 111 is used as a water supplying conduit and the channel 110 is used as a gas supplying conduit. However, as a separate example, a design is also acceptable in which the water supplying conduit and the gas supplying conduit are accomplished as single conduits. Alternatively, it is also acceptable to provide combined use of water supplying conduit and gas supplying conduit. In addition, a design may also be employed in which all the functions are carried out through a single conduit.
The technical scope of the present invention is not limited to the embodiments described above. Rather, various modifications may be added provided that they do not depart from the spirit of the invention.
For example, the stomach was employed as an example of a hollow organ in the above embodiments. However, the present invention is not limited thereto; rather, the present invention may be used with other hollow organs into which an endoscope can be inserted via a natural orifice. In addition, while water was supplied into the stomach ST in the above embodiments, it is also acceptable to supply a liquid medication. When an antibacterial agent is used as the medication, then it is possible to carry out the procedure in combination with disinfecting the stomach ST to remove such bacteria as Helicobacter pylori . It is also acceptable to use an antibiotic as the liquid medication. Further, the sequence for the various steps of the medical operation is not limited to that disclosed in the preceding embodiments; any sequence is permissible, provided that it allows liquid to be supplied into the hollow organ. The same procedure may also be carried out while observation the inside of the body using an observation device of the type that wirelessly sends images taken up by a conventionally known capsule endoscope or other such equipment that is retained inside the body, or a wireless type observation device that uses a device (i.e., device for performing a procedure) having an insertion part that does not have a observation function.
The above embodiments showed a medical operation using an overtube; however, it is also acceptable to insert the endoscope into the body without using the overtube. In this case, it is possible to provide an attaching balloon identical to that of the embodiments, to the insertion part of the endoscope, to seal the space between the insertion part and the hollow organ. | A medical retainer is provided capable of independently controlling supplying air and water to a hollow organ like a stomach and a lumen of a small intestine. The medical retainer for sealing a fluid, the retainer being subject to be retained in a gastrointestinal tract of a patient, the medical retainer includes: a sealing section for sealing the fluid, the sealing section making contact with a wall of the gastrointestinal tract; a main body having passageways; and directional valves disposed in the passageways for allowing one of upward flow and downward flow of the fluid relative to the position of the retainer. | 0 |
BACKGROUND OF THE INVENTION
1. Field of the Invention
The present invention generally relates to control systems for moving a movable member under sequentially applied driving pressures and particularly to such control systems wherein the movement between end points is initially accelerated, then decelerated, and then again accelerated.
2. Description of the Prior Art
Prior art systems used to move movable members, such as machine safety curtains and press bolsters, between predetermined travel points involved driving the member under a constantly applied force during the length of its travel. This involved a constant acceleration of the movable member and produced shocks when the member was stopped at the end points of the travel length. To eliminate these shocks shock absorbers were added at the end points which were springs or hydraulic mechanisms. In either event the shock absorbers had to be carefully sized for the particular mass and speed of the movable member. Further, the shock absorbers tended to wear out and fail under the constant pounding from the movable member and required costly maintenance and replacement.
Some fluid power systems are known which mechanically or time-delay actuate flow control valves or restrictions in the system to throttle the driving device and decelerate the motion of the driven member. However, such devices are operated with incompressible fluids such as liquids and are not readily applied to compressible fluids such as air. Attempts to adapt such devices to compressible fluids causes non-uniform deceleration so that surging and even rebound at the end of driven member travel may result.
Examples of the forementioned devices may be found in U.S. Pat. Nos. 3,803,943; 3,264,942; 2,916,879 and the reader is referred thereto for further detail of structure and operation.
SUMMARY OF THE INVENTION
The present invention solves the mentioned problems associated with prior art devices and others by providing a control system which drives a movable member between end points under the sequential applicaton of a driving pressure for a first part of the travel, a driving and decelerating pressure for a second part of the travel, and only the driving pressure for the remaining part of the travel. This allows the movable member to be speedily moved between the end points while being sufficiently decelerated to obviate the need for any shock absorbers to be placed at the travel end points.
In a particular application of the present invention to massive vertically movable members, such as machine safety curtains, the decelerating pressure used during the second part of the travel is greater than the driving pressure to effectively compensate for the momentum of the accelerated safety curtain. The sequential application of the driving and decelerating pressures is controlled by a reed switch which is actuated by a magnetic member to establish a control signal. The magnet and reed switch assembly is mounted to have the reed switch and magnet be relatively movable with the movement of the safety curtain to thereby sense when the safety curtain has traversed the first and second parts of its travel.
From the foregoing it will be seen that one aspect of the present invention is to provide a control system for quickly moving a movable member between end points without requiring shock absorbers at the end points.
Another aspect of the present invention is to provide a control system which will quickly move and decelerate a massive vertically movable member such as a machine safety curtain.
Yet another aspect of the present invention is to provide a control system for moving a movable member under the sequential application of driving and decelerating pressures.
These and other aspects of the present invention will be more fully understood after a review of the following description of the preferred embodiments and the associated drawings.
BRIEF DESCRIPTION OF THE DRAWINGS
FIG. 1 is an isometric view of a press bolster utilizing the present invention.
FIG. 2 is a schematic of the control system for the press bolster of FIG. 1.
FIG. 3 is an isometric view of a machine safety curtain applied to utilizing the present invention.
FIG. 4 is a schematic of the control system for the safety curtain of FIG. 3.
DESCRIPTION OF THE PREFERRED EMBODIMENT
Referring now to the drawings, FIG. 1 discloses a press assembly 10 having a frame member 12 along which a bolster 14 is moved from a first position, as shown in FIG. 1, out of the press assembly 10 to a second position aligned with a ram (not shown) of the press assembly 10. In the out position a work-piece (not shown) is safely loaded on a die 16 mounted to the bolster 14. The workpiece carrying bolster 14 is then moved into the press 10 where the workpiece is formed by the die 16 and the bolster is again moved out with the finished workpiece.
The movement of the bolster 14 is affected by a pneumatic piston assembly 18 mounted to a stationary mounting frame 20 attached to the frame member 12. The piston assembly has a sealably movable piston (not shown) with a connecting rod 22 extending therefrom connected to the bolster 14. Actuation of the piston assembly either extends or withdraws the connecting rod 22 thereby moving the bolster 14 in and out of the press 10 along guides 24 mounted to the frame member 12.
To expedite production efficiency it is desirable to move the bolster in and out of the press 10 as quickly as possible. This would indicate that a continuous acceleration of the bolster 14 is needed. However, the bolster 14 must be safely stopped at the travel end points and shock absorbers were commonly used for such purposes. Because of the problems associated with such shock absorbers the present bolster 14 is pneumatically buffered at predetermined travel points to allow the bolster 14 to quickly move in and out of the press 10 without requiring shock absorbers at the travel end points.
Predetermined bolster 14 travel positions are detected by a pair of stationary reed switches 26, 28 mounted on a bracket 30 affixed to the piston assembly 18 by screws 32. The reed switches 26, 28 are actuated by magnets mounted on a magnet assembly 34 which is movable with the bolster 14. The magnets actuate the reed switches 26, 28 at different bolster 14 travel positions.
The magnet assembly 34 includes an elongated frame having one end 38 attached to the bolster 14 and another end 40 tied to the first end 38 by tension rods 42. An elongated mounting member 44 connects the two ends 38 and 40 along which the magnets are mounted to pass under the reed switches 26 and 28 as the magnet assembly 34 moves with the bolster.
Turning now to FIG. 2 it will be seen that the air buffering is synchronized to bolster 14 position by a control assembly 46 which sequentially drives and buffers the piston assembly 18 in response to the position of the magnets on the member 44 with respect to the reed switches 26 and 28. The member 44 has an elongated magnetic strip 48 and a short magnetic strip 50 mounted along one side of the member 44 to be movable under the reed switch 26 and an elongated magnetic strip 52 and a short magnetic strip 54 mounted along the opposite side of the member 44 to be movable under the reed switch 28.
The control assembly 46 includes a NOT gate 56 connected to the reed switch 26 and a NOT gate 58 connected to the reed switch 28. The NOT gates 56 and 58 invert the respective signals from the reed switches 26 and 28 and form one input to respective OR gates 60 and 62. The other inputs of the OR gates 60 and 62 are provided by respective command signals indicating that the bolster 14 is to be driven OUT of the press 10 and IN to the press 10. The OR gates 60 and 62 are respectively connected to valves 64 and 66 which are switchable between a position supplying supply S pressure to the piston assembly 18 and venting the piston assembly 18 in response to a control signal from the OR gates 60 and 62.
The piston assembly 18 is shown with piston 68 in a retracted position with the bolster 14 in the press 10 and the end 38 of the mounting member 44 against the reed switches 26 and 28. The magnets 50 and 52 are actuating the reed switches 26 and 28 to provide 1 signals to the NOT gates 56 and 58. The NOT gates 56 and 58 are however inverting the 1 signals to provide 0 signals to the OR gates 60 and 62. Since the respective IN and OUT command signals are maintained until they are reset by the opposite signal, the 1 IN command actuates the OR gate 62 to provide a 1 control signal to the valve 66 causing it to provide supply S pressure along line 70 to one side of the piston 68. The lack of an OUT command to the OR gate 60 provides a second 0 signal to the OR gate 60 thereby maintaining a 0 control signal from the OR gate 60 to the valve 64. Without a 1 control signal to the valve 64 the opposite side of the piston 68 is vented along line 72 through an exhaust 74 of the valve 64. The piston 68 and bolster 14 are thereby maintained in the press 10.
When the 1 OUT command is given to the OR gate 60 the 1 IN command is reset to 0 with the 1 OUT command being continuous. The OUT command then establishes a 1 control signal to the valve 64 from OR gate 60 at the same time as the 1 control signal from the OR gate 62 changes to 0. The valve 64 now supplies supply S pressure through line 72 to the piston 68 while the valve 66 now exhausts the other side of the piston 68 along line 70 through an exhaust 76. The pressure difference across the piston 68 causes the piston to move the bolster 14 and the mounting member 44 out of the press 10. The valve 66 stays in the dotted line exhaust position until the member 44 moves sufficiently, approximately 30% of travel, to prevent the magnetic strip 52 from actuating the reed switch 28. The reed switch then yields a 0 signal to the NOT gate 58 which inverts the 0 signal to a 1 signal to the input of the OR gate 62. The OR gate 62 now switches the valve 66 to the supply S pressure to line 70 to oppose the pressure supply provided to the piston 68 by the valve 64. This causes the bolster 14 to be decelerated while still moving out of the press for approximately the next 60% of travel. When the member 44 moves sufficiently to have the magnetic strip 54 actuate the reed switch 28 the valve 66 again switches to the dotted position to exhaust pressure from line 70 through the exhaust 76. Thus the bolster is positively driven the last 10% of travel by the pressure from valve 64. Since the OUT command is continuously maintained to the OR gate 60 throughout the 100% of travel the signal fluctuations from magnetic strips 48 and 50 actuating the reed switch 26 do not enter into maintaining the one side of the piston 68 pressurized through valve 64.
To move the bolster back out of the press 10 the previous procedure is reversed. The IN command resets the OUT command to 0 while maintaining the opposite side of the piston 68 pressurized through valve 66 throughout 100% of the travel of the bolster 14 and member 44 into the press 10. The magnetic strip 48 now maintains the valve 64 in the exhaust position for the first 30% of travel by actuating the reed switch 26. The next 60% of travel the valve 64 is switched to the dotted supply position by the unactuated reed switch 26 to decelerate the piston 68 movement. The last 10% of travel the reed switch 26 is again actuated to switch the valve 64 back to the exhaust position and positively move the bolster 14 back in to the press 10.
Clearly different driving and decelerating valve positions could be easily provided by varying the lengths and positions of the magnetic strips 48, 50, 52, and 54. It will also be appreciated that the above system is a pneumatic system and could be fitted with resistances to delay the venting and pressurizing of the piston assembly as desired to more effectively air buffer the piston 68.
Turning now to FIG. 3 it will be seen that air buffering may also be applied to vertically dropping safety screens or curtains used to prevent access to machinery such as a press during the working cycle of the machine. To accomplish this a curtain 78 is made to be vertically movable within guide slots 80 mounted to a frame 82. The movement of the curtain 78 is affected by a piston assembly 84 having a connecting member 86 connected to the curtain 78. The piston assembly is air buffered at predetermined curtain 78 positions which are sensed by a pair of reed switches 88 and 90 stationarily mounted to the frame 82. The position of the curtain 78 is signaled by a series of magnetic strips 92, 94 and 96 affixed to the curtain 78 to be movable therewith. Since such curtains 78 usually have a signficant mass buffering their closure is especially important to prevent them from closing too hard and destroying themselves.
As may be best seen with reference to FIG. 4 the piston assembly 84 has a piston 98 which sealably forms two chambers 100 and 102 on opposite sides of the piston 98 which are respectively supplied by lines 104 and 106 extending from a four way valve assembly 108. As shown by the solid line positions of valve assembly 108 when there is no control signal to the valve 108 the chamber 102 is exhausted along a line 110 while the chamber 100 is supplied by a high pressure source S H . This maintains the piston 98 in its upmost position keeping the curtain 78 open. Whenever the valve assembly 108 receives a 1 control signal along line 112 the valve 108 switches to the dotted line positions exhausting chamber 100 to line 110 and supplying chamber 102 with pressure from a low pressure supply S L .
The exhaust line 110 is connected to both a variable restrictor V and to a quick exhaust valve 114 which varies from a normally closed position to a quick exhaust position whenever a 1 control signal is applied to the valve 114 along line 116. This dual connection of line 110 provides either a slow controlled exhaust through the restrictor V when the valve 114 is closed or a substantially immediate exhaust through the valve 114 whenever it is actuated.
Control signals to valves 108 and 114 are supplied by respective AND gates 118 and 120 whenever all their inputs are 1. Since both AND gates 118 and 120 have a common DOWN command input by way of line 122 neither AND gate 118 or 120 will yield a 1 control signal until the DOWN 1 command is initiated even though both reed switches 88 and 90 are actuated by the magnetic strips 94 and 96 to provide 1 signals to the AND gates 118 and 120 along input lines 124 and 126.
When the 1 DOWN command is initiated along line 128 all the inputs of AND gates 118 and 120 become 1 and 1 control signals are established along lines 112 and 116 to valves 108 and 114. The chamber 100 is thus quickly exhausted by the valve 114 through lines 104 and 110 while the chamber 102 is supplied with pressure from S L by valve 108 along line 106. This causes the curtain 78 to start moving down to the closed position. This movement continues until the magnetic strip 96 passes under reed switch 90 and no longer actuates it. The open reed switch 90 causes the output of AND gate 120 to go to 0 and the valve 114 to close preventing further speedy exhausting of chamber 100 therethrough. The chamber 100 must now be exhausted through the restriction V. As the curtain 78 continues down the magnetic strip 94 passes under the reed switch 88 and it also opens causing the output of the AND gate 118 to go to 0. This causes the valve 108 to apply high pressure S H to chamber 100 while exhausting chamber 102 through the restriction V. The higher pressure S H is used to effectively brake the momentum of the curtain 76 and slow it down prior to closure. As the curtain continues down the magnetic strip 92 again actuates the reed switch 88 to close and the AND gate 118 to switch the valve 108 to its initial position venting chamber 100 and pressurizing chamber 102 to S L . This positively closes the curtain 78.
Clearly the same foregoing procedure could be reversed to drive the curtain up. However it was found that because of the mass of the curtain 78 the curtain could be easily and safely driven up at a constantly applied pressure with the mass of the curtain 78 acting to mechanically buffer the upward motion.
Certain improvements and modifications will occur to those skilled in the art upon reading the foregoing. It will be understood that such improvements and modifications were deleted for the sake of conciseness and readability but that they are properly included in the scope of the following claims. | A pneumatically buffered drive system is provided which quickly moves a movable member, such as a press safety curtain or press bolster, a predetermined length in three sequential speed stages to prevent maximum acceleration from occurring at the end of the predetermined length. The movable member is coupled to a differential pressure piston which is initially pressurized on only one side of the piston to initiate movement. After traversing approximately half the predetermined length both sides of the piston are pressurized to decelerate the piston during the member movement for approximately the next third of the predetermined length. The remaining length is traversed with the decelerating pressure being vented to positively finish the motion along the predetermined path. In vertical moving members having significant mass such as press safety curtains, a higher pressure is used to decelerate the piston than the pressure used to drive the piston. The higher decelerating pressure is required to effectively compensate for the momentum of the accelerated vertical member. | 8 |
BACKGROUND OF THE INVENTION
The present invention relates to a wire bonding method for making connection between a die electrode pad and an external lead and more particularly to a method for forming low wire loop during wire bonding.
In wire bonding, when, in order to bond a wire at a second bonding point, a capillary is moved to slightly above the second bonding point, excess wire hangs down from the lower end of the capillary, and a wire shape develops in which a hanging down part is formed. This hanging down part causes a repulsion to occur, when the wire is bonded at the second bonding point, so as to swell upward, resulting in that the straightness of the wire loop deteriorates. Japanese Patent Application Laid-Open Disclosure Nos. (1992) 4-370941 (Japanese Patent No. 3049515) and 2000-82717 disclose wire bonding methods for preventing wire loop from swelling at the time that bonding is made to the second bonding point.
In the method of Japanese Patent Application Laid-Open Disclosure (1992) No. 4-370941 (Japanese Patent No. 3049515), after connecting a wire to a first bonding point, the capillary is positioned slightly above the second bonding point and slightly on the first bonding point side, and then the capillary is descended diagonally in the direction of the second bonding point, thus bonding the wire at the second bonding point. In other words, in the method of Japanese Patent Application Laid-Open Disclosure (1992) No. 4-370941, by way of causing the capillary to descend diagonally, the hanging down part that hangs down from the lower end of the capillary is absorbed.
In the method disclosed in Japanese Patent Application Laid-Open Disclosure (2000) No. 2000-82717, after the wire is connected to a first bonding point, the capillary is lowered slightly from a second bonding point to the first bonding point side so that the capillary presses the hanging down part hanging down from the lower end of the capillary against a horizontal surface, then the capillary is moved to above the second bonding point and then is caused to descend, thus bonding the wire at the second bonding point. In other words, in the method of Japanese Patent Application Laid-Open Disclosure (2000) No. 2000-82717, the wire hanging down from the lower end of the capillary is pressed against a horizontal surface prior to bonding at the second bonding point; as a result, swelling of the wire loop at the time of bonding to the second bonding point is prevented.
Though not directly related to the problems the present invention would resolve, Japanese Patent Application Laid-Open Disclosure (1997) No. 9-51011 hereinafter “JP'51011,” the disclosure of which is herein incorporated by reference, discloses a wire bonding method in which the height of the wire loop from the first bonding point is formed low, of this specification. In this method, in other words, a ball is formed at the tip end of the wire, and this ball is pressure-bonded to a die electrode pad to form a pressure-bonded ball, and then, after performing loop control for moving the capillary to ascend or moving it horizontally, or the like, the wire is pressure-bonded on the pressure-bonded ball to form a wire bonding part. According to JP'51011, by way of performing bonding to the first bonding point, the wire loop height from the first bonding point can be low. For more information on low height loop at the first bonding point, see JP'51011 which is incorporated herein by reference
Even if the capillary is caused to descend diagonally prior to bonding to a second bonding point as disclosed in Japanese Patent Application Laid-Open Disclosure (1992) No. 4-370941 (Japanese Patent No. 3049515), the hanging down part of the wire at the lower end of the capillary, though it is less than that in the conventional method of bonding to a second bonding point, still remains nevertheless. Accordingly, the repulsion caused by plastic deformation of the hanging down part in the wire at the time of bonding at the second bonding point is not avoidable, and swelling occurs in the slanted part of the wire loop.
When the hanging down part is pressed against a horizontal surface, as in the method disclosed in Japanese Patent Application Laid-Open Disclosure (2000) No. 2000-82717, such a banging down part disperses in the interior of the capillary and in the slanted part of the wire loop, causing those respective portions to get loosened. When the capillary ascends to a certain height in the next step, the wire that was loose inside the capillary will be pushed back downward and come out at the lower end of the capillary. Since the wire that came out at the lower end of the capillary at the next bonding to the second bonding point is pressed against the second bonding point, similar to Japanese Patent Application Laid-Open Disclosure (1992) No. 4-370941 repulsion caused by plastic deformation in the wire occurs, and swelling does occur in the slanted part of the wire loop though the amount thereof is smaller than with the conventional method of bonding to the second bonding point.
SUMMARY OF THE INVENTION
Accordingly, the object of the present invention is to provide a wire bonding method in which wire loop is prevented from swelling, thus improving the wire loop straightness.
The above object is accomplished by a set of unique steps of the present invention for a wire bonding method for connecting a wire, which passes through a capillary, between an electrode pad that is a first bonding point and an external lead that is a second bonding point with a use of the capillary; and in the present invention,
after finishing bonding to the electrode pad (first bonding point), the capillary is, together with a clamper, moved to above the external lead (second bonding point); then the capillary (and the clamper) is, with the clamper opened, caused to descend from above the external lead, so that the wire is pressed to such extent as that the wire is not completely connected to the external lead, thus forming a thin part in the wire; next the clamper is closed, and the capillary (and the closed clamper) is caused to ascend, together with the thin part, to substantially the same height as the first bonding point; the capillary (and the clamper) is next moved in a direction away from (or opposite from) the first bonding point, thus pulling the wire bonded to the first bonding point, so that the pulled wire is made into a linear wire portion, and in conjunction therewith, is cut (separated) at the thin part; then the capillary (and the clamper) is moved back in the direction toward the first bonding point and then caused to descend so that the end of the linear wire portion, or the thin part at the end of the linear wire portion, is pressed by the capillary and bonded to the external lead (second bonding point) and, in conjunction therewith, the wire tip end at the lower end of the capillary is bonded also to the external lead; and further, the clamper is opened, and the capillary (and the clamper) is caused to ascend; and during this ascending motion of the capillary, the clamper is closed so that the wire tip end at the lower end of the capillary peeled away (separated) from the external lead, thus forming a tail portion on the wire extending out of the lower end of the capillary, such a tail portion to be used for the next first bonding.
The above object is accomplished by another set of unique steps of the present invention for a wire bonding method for connecting a wire, which passes through a capillary, between an electrode pad that is a first bonding point and an external lead that is a second bonding point with a use of the capillary; and in the present invention,
after finishing bonding to the electrode pad (first bonding point), the capillary is, together with a clamper, moved to above the external lead (second bonding point); then the capillary (and the clamper) is, with the clamper opened, caused to descend from above the external lead, so that the wire is pressed to such extent as that the wire is not completely connected to the external lead, thus forming a thin part in the wire; next the clamper is closed, and the capillary (and the closed clamper) is caused to ascend, together with the thin part, to substantially the same height as the first bonding point; the capillary (and the clamper) is next moved in a direction away from (or opposite from) the first bonding point, thus pulling the wire bonded to the first bonding point, so that the pulled wire is made into a linear wire portion, and in conjunction therewith, is cut (separated) at the thin part; next, the capillary (and the clamper) is caused to descend, and the wire tip end at the lower end of the capillary is bonded to the external lead; then, the clamper is opened, and the capillary (and the clamper) is caused to ascend; and during this ascending motion of the capillary, the clamper is closed so that the wire tip end at the lower end of the capillary peeled away (separated) from the external lead, thus forming a tail portion on the wire extending out of the lower end of the capillary; after forming a ball in this tail portion, the clamper is opened, and the capillary (and the clamper) is moved back in the direction toward the first bonding point and then caused to descend so that the ball is pressed against the end of the above-described linear wire portion, and the ball, together with the end of the linear wire portion, is bonded to the external lead, thus forming a pressure-bonded ball; and then the capillary (and the clamper) is caused to ascend, and during this ascending motion of the capillary, the clamper is closed, so that the wire is cut from the pressure-bonded ball, thus forming a tail portion extending out of the lower end of the capillary, such a tail portion to be used for the next first bonding.
As seen from the above, in the present invention, the capillary is, after the bonding at the first bonding point, moved in a direction away from the first bonding point, thus pulling the wire connected to the first bonding point and making it a linear wire portion, and then this linear wire portion is cut (separated) from the wire at the thin part. Thus, with this step, a spring-up part is formed in the wire bonded to the first bonding point and is then pulled and cut at the thin part to make a one-side supported linear wire portion, and the end of this one-side supported linear wire portion is pressed by the capillary and bonded to the external lead, wherefore wire loop straightness is enhanced.
BRIEF DESCRIPTION OF THE SEVERAL VIEWS OF THE DRAWINGS
FIGS. 1( a ) through 1 ( c ) show the steps of the wire bonding method according to the first embodiment of the present invention;
FIGS. 2( a ) through 2 ( c ) show the steps continuing from FIG. 1( c );
FIGS. 3( a ) and 3 ( b ) show the steps continuing from FIG. 2( c );
FIGS. 4( a ) through 4 ( c ) show the steps of the wire bonding method according to the second embodiment of the present invention;
FIGS. 5( a ) through 5 ( c ) show the steps continuing from FIG. 4( c ); and
FIGS. 6( a ) and 6 ( b ) show the steps continuing from FIG. 5( c ).
DETAILED DESCRIPTION OF THE INVENTION
A first embodiment of the wire bonding method of the present invention will be described with reference to FIGS. 1( a ) through 3 ( b ).
On a lead frame 2 on which an external lead 1 is formed, a die 4 having thereon an electrode pad 3 is formed is mounted. As seen from FIG. 3( b ), a wire 10 passes through a capillary 5 . The reference numeral 6 indicates a clamper which makes the same horizontal and vertical motions as the capillary 5 whenever the capillary 5 is moved horizontally and vertically.
First of all, bonding is performed at the first bonding point A (first bonding) shown in FIG. 1( a ), thus forming a pressure-bonded ball 11 and, on the pressure-bonded ball 11 , a wire bonding part 12 . The forming of this pressure-bonded ball 11 and wire bonding part 12 is effected by the method of, for instance, Japanese Patent Application Laid-Open Disclosure (1997) No. 9-51011. For more information on low height loop at the first bonding point, see JF'51011 which is incorporated herein by reference.
In other words, as seen from FIG. 3( b ), with the clamper 6 closed, a ball 14 is formed in the tail piece 13 of the wire extending out of the lower end of the capillary 5 , by a spark discharge made by an electric torch (not shown in the drawings).
Next, the clamper 6 attains its open condition, the capillary 5 (and the clamper 6 ) descends after moving above the first bonding point A, and the ball 14 is bonded to the first bonding point A, and then, as seen from FIG. 1( a ), the pressure-bonded ball 11 is formed.
Then, after performing loop control for moving the capillary 5 (and the clamper 6 ) so as to ascend or moving it horizontally, or the like, the wire 10 is pressure-bonded on the pressure-bonded ball 11 to form the wire bonding part 12 .
After that, the capillary 5 (and the clamper 6 ) is moved so that the capillary 5 is positioned slightly above the second bonding point B of the external lead 1 . In this case, a hanging down part 15 of the wire resulting from the excess wire 10 hanging down from the lower end of the capillary 5 is formed.
Next, as shown in FIG. 1( b ), the capillary 5 (and the clamper 6 ) is caused to descend, the wire 10 is pressed against the external lead 1 of the lead frame 2 , and as a result a thin part 16 is formed in the wire. When the wire 10 is pressed against the external lead 1 , the hanging down part 15 of the wire springs up, forming a spring-up part 17 ; and in this case, the thin part 16 of the wire is not completely connected to the external lead 1 ; in other words, a part of the wire is pressed (crushed) by the capillary to make the thin part 16 so that the thin part 16 is raised together with the capillary when the clamper 6 closes and the capillary 5 ascends (with the clamper 6 ) in the next step shown in FIG. 1( c ).
Next, the clamper 6 closes and, as shown in FIG. 1( c ), the capillary 5 is caused to ascend to substantially the same height as the first bonding point A.
Then, as shown in FIG. 2( a ), the capillary 5 (and the clamper 6 ) is moved horizontally in a direction away from (or opposite from) the first bonding point A with the clamper closed. With this horizontal motion of the capillary 5 (and the clamper 6 ), the spring-up part 17 is pulled, and a substantially linear wire portion 18 is formed in the wire that is bonded to the first bonding point, and, in conjunction therewith, the linear wire portion 18 is cut at the thin part 16 .
Next, as shown in FIG. 2( b ), the capillary 5 (and the clamper 6 ) is moved back in a direction toward the first bonding point A so that the lower end of the capillary 5 is positioned above the end 19 of the linear wire portion 18 that has the thin part.
In the next step (second bonding) shown in FIG. 2( c ), the capillary 5 (and the clamper 6 ) is caused to descend, and the end 19 of the linear wire portion 18 is bonded to the external lead 1 or at the second bonding point B. At this time, the wire tip end part 20 extending slightly from the lower end of the capillary 5 is connected also to the external lead 1 .
Then, the clamper 6 opens as shown in FIG. 2( c ); and, as shown in FIGS. 3( a ) and 3 ( b ), the capillary 5 (and the clamper 6 ) is ascended. During this ascending motion of the capillary 5 (and the clamper 6 ), that is, when the capillary 5 (and the clamper 6 ) is ascending in FIG. 3( a ), the clamper 6 closes as shown by arrows in FIG. 3( a ). As a result, as shown in FIG. 3( b ), the wire is pulled upward by the clamper, and the wire tip end part 20 is peeled away (separated) from the external lead 1 , and as a result, a tail piece 13 is formed in the wire at the lower end of the capillary 5 . After a ball 14 is formed in this tail piece 13 by an electric torch (not shown), the bonding process shifts to the step shown in FIG. 1( a ).
As seen from the above, in the steps shown in FIG. 1( c ) to FIG. 2( a ), the spring-up part 17 is pulled and is cut at the thin part 16 , thus forming a one-side supported linear wire portion 18 . The end 19 of this one-side supported linear wire portion 18 is, as seen from FIGS. 2( b ) and 2 ( c ), pressed by the capillary 5 and bonded to the second bonding point B; accordingly, wire loop straightness is enhanced.
A second embodiment of the wire bonding method of the present invention will be described with reference to FIGS. 4( a ) to 6 ( b ). The second embodiment takes the same steps as in the above-described first embodiment shown in FIG. 1( a ) to FIG. 2( a ). FIG. 4( a ) corresponds to the step shown in FIG. 2( a ).
In the above-described first embodiment, after the step shown in FIG. 2( a ), the end 19 of the linear wire portion 18 is bonded directly to the second bonding point B by the capillary 5 . In this second embodiment, after the step of FIG. 4( a ) ( FIG. 2( a )), the end 19 of the linear wire portion 18 is not bonded directly to the second bonding point B by the capillary 5 .
After the step shown in FIG. 4( a ) (or the steps in FIGS. 1( a ) through 2 ( a )), the capillary 5 (and the clamper 6 ) is, as shown in FIG. 4( b ), caused to descend, and the wire tip end part 20 is lightly connected (prebonded) to the external lead 1 .
Then, the clamper 6 next opens as shown in FIG. 4( b ); and, as seen from FIGS. 4( c ) and 5 ( a ), the capillary 5 (and the clamper 6 ) is caused to ascend. During this ascending motion of the capillary 5 (and the clamper 6 ), that is, when the capillary 5 (and the clamper 6 ) is ascending in FIG. 4( c ), the clamper 6 closes. As a result, as shown in FIG. 5( a ), the wire tip end part 20 is peeled away (separated) from the external lead 1 , and a tail portion 25 is formed in the wire in the lower end of the capillary 5 . In this tail portion 25 , a ball 26 is next formed by a spark discharge made by an electric torch (not shown).
Next, with the clamper 6 attaining its open condition, and the capillary 5 (and the clamper 6 ) is moved back in the direction toward the first bonding point A and to above the end 19 of the linear wire portion 18 .
Then, as shown in the step (second bonding) of FIG. 5( c ), the capillary 5 (and the clamper 6 ) is descended, thus pressing the end 19 of the linear wire portion 18 against the external lead 1 , and, in conjunction therewith, bonding the ball 26 on the end 19 of the linear wire portion 18 to the external lead 1 , thus forming a pressure-bonded ball 27 .
Next, as shown in FIGS. 6( a ) and 6 ( b ), the capillary 5 (and the clamper 6 ) is caused to ascend. During the ascending motion of the capillary 5 (and the clamper 6 ), that is, when the capillary 5 (and the clamper 6 ) is ascending in FIG. 6( a ), the clamper 6 closes; as a result, as seen from FIG. 6( b ), the wire 10 is cut from the upper end of the pressure-bonded ball 27 , and the tail piece 13 is formed in the wire at the lower end of the capillary 5 . After forming a ball 14 in the tail piece 13 by a spark discharge made by an electric torch (not shown), the bonding process shifts to the step shown in FIG. 1( a ).
In this second embodiment of the present invention as well, since the end 19 of the one-side supported linear wire portion 18 is bonded to the second bonding point B, wire loop straightness is enhanced as in the above-described first embodiment. In this second embodiment, moreover, since the pressure-bonded ball 27 is formed in the end 19 bonded to the second bonding point B, the thickness of the bonding to the second bonding point B is thick (or thicker than in the first embodiment), and the strength at the second bonding point B is enhanced.
In the embodiments described above, the bonding to the first bonding point A is performed in accordance with the method disclosed in JP'51011 which is incorporated herein by reference; however, the present invention is not limited to use this method, and any ordinary bonding method can be used in the present invention. However, with the bonding method of JP'51011 which is incorporated herein by reference, it is possible to keep the rise from the first bonding point A low, which is preferable. | A wire bonding method including the steps of: descending a capillary 5 from above an external lead 1 to press a wire 10 to such an extent that the wire is not completely connected to the external lead 1 , thus forming a thin part 16 in the wire; next ascending the capillary 5 and the thin part 16 to substantially the same height as a first bonding point A, then moving the capillary 5 in a direction away from the first bonding point A, thus making a linear wire portion 18 and then cutting the wire at the thin part 16 ; then connecting the end 19 (thin part) of the linear wire portion 18 and the wire tip end 20 at the lower end of the capillary 5 are connected to the external lead 1 ; and then separating the wire tip end 20 from the external lead 1. | 8 |
BACKGROUND OF THE INVENTION
This invention pertains to inhalation therapy enclosures for small animals.
In the practice of veterinary medicine, the treatment of diseased or injured animals encompasses administration of medications by injection or by mouth, as well as by inhalation of nebulized medications. Current methods for respiratory therapy through administration of nebulized medications consist of use of a mask held over the nose and mouth of the animal, or by forcing the animal into a closed chamber into which nebulized medication is introduced. Typically, the chamber is an open topped box with a lid held in place to trap the animal inside. Because an animal in compromised health is already under stress, the reaction of an animal to being placed in an open-topped box is to resist this mode of therapy, to become fractious and increasingly stressed and less responsive to therapy. Similarly, the forced placement of a mask over the nose and mouth of a fearful animal is stressful for both animal and veterinarian staff, and results in less successful administration of medication.
In the administration of general anesthesia to small animals, inhalation of anesthetic gases either must be administered by mask or through placement of the animal into an anesthetic induction chamber into which anesthetic gas is introduced. Again the typical anesthetic induction chamber is an open topped plastic box with a lid. In the case of cats and other small animals, the forced placement of the animal into an open topped box frequently results in fractious behavior by the animal accompanied by elevation of stress in the animal and the veterinary staff.
An example of an anesthetic induction chamber for animals is shown in U.S. Pat. No. 6,353,076 to French which shows an elongate box with a top lid and an end door.
BRIEF SUMMARY OF THE INVENTION
The present invention pertains to equipment to assist in the administration of inhalants in the practice of veterinary medicine. Particularly, the invention pertains to administration of nebulized medicaments to small animals such as cats, ferrets, small dogs, rats, birds, small reptiles and like sized pets.
Uncooperative or medically compromised animal patients are easily treated with inhalation therapy provided the inhalation therapy can be successfully administered. The present invention presents an enclosure for small animals which includes a base with a rear wall and opposing end walls upstanding from edges of the base. The combination of the base, rear wall, and opposing end walls provides a structure with an open top and an open side. A cover assembly is attached to the top of the rear wall by hinges such that the cover can be rotated about the hinges to either close the enclosure or to open the enclosure. Rest brackets extend from the rear wall to provide structures for the open cover to rest against. The cover includes a first panel which serves as the top of the resulting enclosure, and a second panel fixed perpendicularly to the first panel, the second panel providing a front wall for the resulting enclosure. A large portion of each panel is an unbreakable transparent window made of tempered or shatterproof glass or clear acrylic or clear polycarbonate. Latching devices are provided on the base and second panel to retain the cover in place when desired. A port is provided through each of the opposing end walls at a height above the mid-point of the end wall. Each port includes a ribbed tube to which a hose may be attached. The diameter of both ports is substantially equal. When desired to be used for administration of nebulized medications, a hose interconnects the first port with a nebulizer. A second hose may be attached to the port on the opposing sidewall to duct away exhaust exiting the second port.
The enclosure may also be used as an anesthetic inhalation chamber. In the case of administration of inhalable anesthetic compounds, the port in the first end wall may be connected to tubing coupled to a source of anesthetic gas and the port in the second end wall may be coupled to a hose transmitting the uninhaled gases to a scavenging or recapture system.
The enclosure may also be used as an oxygen inhalation chamber. In the case of administration of inhalable oxygen, the intake port in the first sidewall may be connected to tubing coupled to a source of oxygen and the exhaust port in the second sidewall may be left open.
The enclosure may also be configured as a portable pet carrier by substitution of the transparent windows in the cover panels by open cage wall structures such that ventilation is adequate.
It is a primary object of the invention to provide an enclosure to receive a small animal requiring inhalation therapy which avoids stress in that animal when the animal is placed in the enclosure. It is a further object to provide an enclosure for small animals which the animal will willingly enter. It is also an object of the invention to provide an inhalation therapy enclosure in which nebulized medication may be effectively administered to an ill animal. Another object of the invention is to provide an inhalation therapy enclosure in which the animal is comfortable and unrestrained. It is yet another object of the invention to provide an enclosure for a small animal which allows observation of the animal while enclosed and from which the animal may observe the environment exterior to the enclosure. A further object of the invention is to provide an transportable enclosure into which a pet owner can place his or her pet preparatory to surgery and which can be used to transport the animal to surgery and in which anesthetic can be conveniently administered without further handling of the pet, while allowing the pet to be observed as anesthetic is administered.
The foregoing and other desirable objects of the invention will be understood from an examination of the detailed description of the invention which follows.
BRIEF DESCRIPTION OF THE SEVERAL VIEWS OF THE DRAWING(S)
FIG. 1 is a front perspective of a veterinary treatment system for administration of nebulized medication, according to the present invention.
FIG. 2 is a side plan view of the enclosure of the invention with the cover fully open.
FIG. 3 is a front elevation of the enclosure invention with the cover fully open.
FIG. 4 is a cross section view along line 4 - 4 of FIG. 3 .
FIG. 5 is a front elevation of an alternative embodiment of the invention wherein intake port 12 and exhaust port 54 are located in rear wall 20 of enclosure 4 .
DETAILED DESCRIPTION OF THE INVENTION
This invention is an inhalation therapy enclosure for small animals. The invention may be used as an enclosure for administration of nebulized medication, as an anesthetic induction chamber or as an oxygen inhalation chamber. In an alternative embodiment, the invention may be used as a portable pet carrier.
FIG. 1 discloses a system 2 for administration of nebulized medicaments for treatment of veterinary patients. The medicament may be any drug with the property of being delivered via nebulization or atomization including but not limited to antibiotics, bronchodilators, steroids, insulin, oxygen, or any other medicament that can be absorbed in the oral or nasal mucosa or lungs of an animal, or a drug which may be absorbed transdermally.
A closable enclosure 4 is coupled to a nebulizer cup 6 containing a liquid medicament to be nebulized. A nebulizer pump 8 is coupled by air duct 10 to the nebulizer cup 6 such that air may be bubbled through the liquid medicament within nebulizer cup 6 to be atomized to a mist or vapor to be passed through intake port 12 in first sidewall 14 into the interior 16 of enclosure 4 . Together the nebulizer pump 8 , nebulizer cup 6 and air duct 10 are a nebulizing apparatus which is well known.
Enclosure 4 further comprises a base 18 which serves as a bottom of the enclosure 4 , a rear wall 20 and a second sidewall 22 which opposes first sidewall 14 . In the substantially rectangular embodiment of enclosure 4 of FIG. 1 , each of sidewalls 14 , 22 and rear wall 20 is upstanding upon edges of base 18 . A cover 24 is hinged to top edge 26 of rear wall 20 such that cover 24 may pivot about top edge 26 of rear wall 20 from an open position as seen in FIG. 1 to a closed position with the free edge 28 of cover 24 abutted to base 18 at the front 30 thereof.
Cover 24 comprises a first panel 32 joined at a substantial perpendicular to second panel 34 . First panel 32 is hinged to top edge 26 of rear wall 20 . Second panel 34 could be joined to first panel 32 by a hinge if desired, but in the preferred embodiment of FIGS. 1-3 , second panel 34 is joined to first panel 32 at a fixed angle. Depending on the geometry of sidewalls 14 , 22 , first panel 32 could be joined to second panel 34 over a range of angles from approximately forty-five degrees to approximately one hundred thirty-five degrees.
When cover 24 is moved to the closed position, in addition to the abutment of free edge 28 to front 30 , first side edge 36 of first panel 32 abuts top edge 38 of first sidewall 14 and second side edge 40 of first panel 24 abuts top edge 42 of second sidewall 22 . In addition, first side edge 44 of second panel 34 abuts front edge 46 of first sidewall 14 and second side edge 48 of second panel 34 abuts front edge 50 of second sidewall 22 . Rabbets 52 along edges 50 , 42 , 40 , 48 and along edges 46 , 38 , 36 , 44 permit a substantially air tight fit of cover 24 to sidewalls 14 and 22 and to base 18 thereby creating a sealed enclosed space within interior 16 of enclosure 4 .
Exhaust port 54 passes through second sidewall 22 to provide a passageway for exhaled or uninhaled gases to escape. Exhaust port 54 may be located in second sidewall 22 at approximately the same vertical position as that of intake port 12 in first sidewall 14 , generally above the vertical midpoint thereof.
In the preferred embodiment, the enclosure is rectilinear though other shapes may be employed provided the cover 24 serves as top and a side of the resulting enclosure. The preferred embodiment enclosure 4 encloses a volume of approximately one cubic foot.
Referring now additionally to FIG. 2 , it can be seen that enclosure 4 comprises rest brackets 56 against which cover 24 may rest when fully open. Brackets 56 serve as stops to limit the travel of cover 24 about hinge 58 . Brackets 56 comprise upwardly extending outwardly angled arms 78 .
A handle 60 is mounted to cover 24 near its free edge 28 and a pair of latches 62 are fixed to cover 24 upon outer face 64 of second panel 34 such that the bails 66 of latches 62 may capture catches 68 when cover 24 is lowered to its closed position.
Each of panels 32 , 34 of cover 24 further comprises frames 70 , 72 which are formed with peripheral recesses 74 to permit the resting of panel edges within rabbets 52 of sidewalls 14 , 22 and rear wall 18 .
Referring now to FIG. 3 , it is seen that each of panels 32 , 34 of cover 24 of enclosure 4 includes a transparent window 80 , 82 of clear acrylic or clear polycarbonate or of glass, preferably tempered or shatterproof glass. The inclusion of windows 80 , 82 provides the ability for veterinary staff to observe a cat or other small animal housed in closed enclosure 4 as anesthesia is administered or as treatment with nebulized medicament is carried out.
It can also be understood from examination of FIG. 3 that intake port 12 and exhaust port 54 comprise tubes 84 which extend from respective sidewalls 14 , 22 such that flexible hoses may be attached to the tubes 84 of ports 12 and 54 . Tubes 84 may be tapered to ease placement of plastic tubing over them, or they may be provided with annular ribs (not shown) in the conventional manner to assist in frictional retention of tubing to tubes 84 .
In the case of the use of enclosure 4 as an anesthesia induction chamber, a source of anesthetic gas (not illustrated) may be coupled to one of ports 12 , 54 through conventional hose or tubing so that the anesthetic gas can be passed into the enclosure while uninhaled or exhaled gas may be vented from the port not used for insertion of the anesthetic gas.
The enclosure 4 may also be used as an oxygen inhalation chamber. In the case of administration of inhalable oxygen, the intake port 12 in the first side end wall 14 may be connected to tubing coupled to a source of oxygen and the exhaust port 54 in the second sidewall 22 may be left open.
Referring now to FIG. 4 , a cross section view of the enclosure 4 is illustrated. Bracket 56 extends from outer face 86 of rear wall 20 , with the arm 78 of bracket 56 extending upward and away from the plane of outer face 86 . Arm 78 is angled appropriately to parallel the outer face 88 of first panel 32 of cover 24 thereby to provide a stop or rest for cover 24 when it is fully open. It can be seen that first panel 32 joins second panel 34 at a substantial perpendicular and that window 82 is retained in slots 90 of frame 72 of second panel 34 . Window 82 comprises a substantial area of second panel 34 . Similarly, window 80 of first panel 32 makes up a large proportion of the area of first panel 32 and is retained in slots 92 of frame 70 .
Base 18 is provided with a shelf 94 to receive the tongue 96 of second panel 34 when cover 24 is lowered to the fully closed position. Rabbets 52 allow for a snug and substantially airtight closure of cover 24 in abutment with second sidewall 22
The foregoing description of the invention has been presented for purposes of illustration and description and is not intended to be exhaustive or to limit the invention to the precise form disclosed. Modifications and variations of the embodiments are possible in light of the above disclosure or such may be acquired through practice of the invention. The embodiments illustrated were chosen in order to explain the principles of the invention and its practical application to enable one skilled in the art to utilize the invention in various embodiments and with various modifications as are suited to the particular use contemplated. It is intended that the scope of the invention be defined by the claims appended hereto, and by their equivalents. | An inhalation therapy enclosure includes a base with end walls joined by a rear wall. A cover having two panels joined perpendicularly is hinged to the top of the rear wall. When lowered, the cover forms an enclosure with the end wall, rear wall and base. Latches secure the cover to the base. A port in one end wall allows introduction of nebulized medication or anesthesia while a port of equal size in the opposing end wall allows exhaust from the enclosure. | 0 |
RELATED APPLICATIONS
This application claims the benefit of U.S. Provisional Application No. 60/069,591, filed Dec. 12, 1997.
FIELD OF THE INVENTION
This invention is directed to the use of 2000 series alloy plate to be used for wing and structural intermediaries for aerospace applications.
BACKGROUND OF THE INVENTION
The demands put on aluminum alloys have become more and more rigorous with each new series of airplane manufactured by the aerospace industry. The push is to provide aluminum alloys that are stronger and tougher than the generation of alloys before so that the aircraft industry may reduce the mass of the airplanes it builds to extend the flight range, and to realize savings in fuel, engine requirements, and other economies that can be achieved by a lighter airplane. The quest, no doubt, is to provide the aircraft industry with a high toughness and high strength aluminum alloy that is lighter than air.
U.S. Pat. No. 5,213,639 is directed to an invention which provides a 2000 series alloy which provides an aluminum product with improved levels of toughness and fatigue crack growth resistance at good strength levels. As is fully explained in that patent, which is herein incorporated by reference, there are often trade-offs in the treatment of an aluminum alloy in which it is difficult not to compromise one property in order to increase another by some alteration to the process for the manufacture of the alloy. For example, by changing the heat treatment or aging of the alloy to increase the strength, the toughness levels may decrease. The ultimate desire to those skilled in the aluminum alloy art is to be able to change one property without decreasing some other property and, thereby, making the alloy less desirable for its intended purpose.
Fracture sensitive properties in structural aerospace products, such as fracture toughness, fatigue initiation resistance, and resistance to the growth of fatigue cracks, are adversely affected by the presence of second phase constituents. This is related to the stresses which result from the load during service that are concentrated at these second phase constituents or particles. While certain aerospace alloys have incorporated the use of higher purity base metals to enhance the fracture sensitive properties, their property characteristics still fall short of the desired values, particularly fracture toughness, such as in the 2324-T39 lower wing skin plate alloy, which is considered a standard in the aerospace industry. This goes to demonstrate that the use of high purity base metal by itself is insufficient to provide the maximum fracture and fatigue resistance in the alloy.
The invention hereof provides an increase in properties selected from the group consisting of plane strain and plane stress fracture toughness, an increase in fatigue life, and an increase in fatigue crack growth resistance and combinations thereof. These are all desirable properties in an aerospace alloy. In the practice of this invention the alloy incorporates a balanced composition control strategy by the use of the maximum heat treating temperature while avoiding the incipient melting of the alloy. The use of high purity base metal and a systematic calculation from empirically derived equations is implemented to determine the optimum level of major alloying elements. Accordingly, the overall volume fraction of constituents derived from iron and silicon as well as from the major alloying elements copper and magnesium are kept below a certain threshold composition.
Increasing the above properties across the board allows the aerospace industry to design their planes differently since these properties will be consistently obtained under the practice of this invention. The present inventive alloys will be found useful for the: manufacture of passenger and freight airplanes and will be particularly useful as structural components in aerospace products that bear tensile loads in service such as in the lower wing.
SUMMARY OF THE INVENTION
The present invention is directed to the 2000 series composition aluminum alloys as defined by the Aluminum Association wherein the composition comprises in weight percent about 3.60 to 4.25 copper, about 1.00 to 1.60 magnesium, about 0.30 to 0.80 manganese, no greater than 0.05 silicon, no greater than 0.07 iron, no greater than 0.06 titanium, no greater than 0.002 beryllium, the remainder aluminum and incidental elements and impurities. Preferably, the composition comprises in weight percent 3.85 to 4.05 copper, 1.25 to 1.45 magnesium, 0.55 to 0.65 manganese, no greater than 0.04 silicon, no greater than 0.05 iron, no greater than 0.04 titanium, no greater than 0.002 beryllium, the remainder aluminum and incidental elements and impurities. When citing a range of the alloy composition, the range includes all intermediate weight percents such as for magnesium, 1.00 would include 1.01 or 1.001 on up through and including 1.601 up to 1.649. This incremental disclosure includes each component of the present alloy.
In the practice of the invention, the heat treating temperature, T max , should be controlled at as high a temperature as possible while still being safely below the lowest incipient melting temperature of the alloy, which is about 935° F. (502° C.). The observed improvements are selected from the group consisting of plane strain and plane stress fracture toughness, fatigue resistance, and fatigue crack growth resistance, and combinations thereof while essentially maintaining the strength, is accomplished by ensuring that the second phase particles derived from Fe and Si and those derived from Cu and/or Mg are substantially eliminated by composition control and during the heat treatment. The Fe bearing second phase particles are minimized by using high purity base metal with low Fe content. While it is desirable to have no Fe or Si at all, but for the commercial cost thereof, a low Fe and Si content according to the preferred composition range described hereinabove is acceptable for the purposes of the present invention.
In the practice of the invention, the heat treating temperature, T max , should be controlled at as high a temperature as possible while still being safely below the lowest incipient melting temperature of the alloy, which is about 935° F. (502° C.). The observed improvements is selected from the group consisting of plain strain and plane stress fracture toughness, fatigue resistance, and fatigue crack growth resistance, and combinations thereof while essentially maintaining the strength, is accomplished by ensuring that the second phase particles derived from Fe and Si and those derived from Cu and/or Mg are substantially eliminated by composition control and during the heat treatment. The Fe bearing second phase particles are minimized by using high purity base metal with low Fe content. While it is desirable to have no Fe and Si at all, but for the commercial cost thereof, a low Fe and Si content according to the preferred composition range described hereinabove is acceptable for the purposes of the present invention.
The fracture toughness of an alloy is a measure of its resistance to rapid fracture with a preexisting crack or crack-like flaw present. The plane strain fracture toughness, KIc, is a measure of the fracture toughness of thick plate sections having a stress state which is predominantly plane strain. The apparent fracture toughness, K app , is a measure of fracture toughness of thinner sections having a stress state which is predominately plane stress or a mixture of plane stress and plane strain. The inventive alloy can sustain a larger crack than the comparative alloy 2324-T39 in both thick and thin sections without failing by rapid fracture. Alternatively, the inventive alloy can tolerate the same crack size at a higher operating stress than 2324-T39 without failure.
Typically, cold or other working may be employed which produces a working effect similar to (or substantially, i.e. approximately, equivalent to) that which would be imparted by stretching at room temperature in the range of about ½% or 1% or 1½% to 2% or up to 4 or 6% or 8% of the products original length. Stretching or other cold working such as cold rolling about 2 or 3 or 9 or 10%, preferably about 4 or 5% to about 7 or 8%, can improve strength while retaining good toughness. Yield strength can be increased around 10 ksi, for instance to levels as high as around 59 or 60 ksi or more without excessively degrading toughness, even actually increasing toughness by 5 or 6 ksiin (K c in L-T orientation), in one test by stretching 6 or 7%.
When referring to a minimum (for instance for strength or toughness) or to a maximum (for instance for fatigue crack growth rate), such refers to a level at which specifications for materials can be written or a level at which a material can be guaranteed or a level that an airframe builder (subject to safety factor) can rely on in design. In some cases, it can have a statistical basis wherein 99% of the product conforms or is expected to conform with 95% confidence using standard statistical methods.
Fracture toughness is an important property to airframe designers, particularly if good toughness can be combined with good strength. By way of comparison, the tensile strength, or ability to sustain load without fracturing, of a structural component under a tensile load can be defined as the load divided by the area of the smallest section of the component perpendicular to the tensile load (net section stress). For a simple, straigh T-sided structure, the strength of the section is readily related to the breaking or tensile strength of a smooth tensile coupon. This is how tension testing is done. However, for a structure containing a crack or crack-like defect, the strength of a structural component depends on the length of the crack, the geometry of the structural component, and a property of the material known as the fracture toughness. Fracture toughness can be thought of as the resistance of a material to the harmful or even catastrophic propagation of a crack under a tensile load.
Fracture toughness can be measured in several ways. One way is to load in tension a test coupon containing a crack. The load required to fracture the test coupon divided by its net section area (the cross-sectional area less the area containing the crack) is known as the residual strength with units of thousands of pounds force per unit area (ksi), When the strength of the material as well as the specimen are constant, the residual strength is a measure of the fracture toughness of the material. Because it is so dependent on strength and geometry, residual strength is usually used as a measure of fracture toughness when other methods are not as useful because of some constraint like size or shape of the available material.
When the geometry of a structural component is such that it doesn't deform plastically through the thickness when a tension load is applied (plane-strain deformation), fracture toughness is often measured as plane-strain fracture toughness, K Ic . This normally applies to relatively thick products or sections, for instance 0.6 or 0.75 or 1 inch or more. The ASTM has established a standard test using a fatigue pre-cracked compact tension specimen to measure K Ic which has the units ksiin. This test is usually used to measure fracture toughness when the material is thick because it is believed to be independent of specimen geometry as long as appropriate standards for width, crack length and thickness are met. The symbol K, as used in K Ic is referred to as the stress intensity factor. A narrower test specimen width is sometimes used for thick sections and a wider test specimen width for thinner products.
Structural components which deform by plane-strain are relatively thick as indicated above. Thinner structural components (less than 0.6 to 0.75 inch thick) usually deform under plane stress or more usually under a mixed mode condition. Measuring fracture toughness under this condition can introduce variables because the number which results from the test depends to some extent on the geometry of the test coupon. One test method is to apply a continuously increasing load to a rectangular test coupon containing a crack. A plot of stress intensity versus crack extension known as an R-curve (crack resistance curve) can be obtained this way. The load at a particular amount of crack extension based on a 25% secant offset in the load vs. crack extension curve and the crack length at that load are used to calculate a measure of fracture toughness known as K R25 . It also has the units of ksiin. ASTM E561 (incorporated by reference) concerns R-curve determination.
When the geometry of the alloy product or structural component is such that it permits deformation plastically through its thickness when a tension load is applied, fracture toughness is often measured as plane-stress fracture toughness. The fracture toughness measure uses the maximum load generated on a relatively thin, wide pre-cracked specimen. When the crack length at the maximum load is used to calculate the stress-intensity factor at that load, the stress-intensity factor is referred to as plane-stress fracture toughness K c . When the stress-intensity factor is calculated using the crack length before the load is applied, however, the result of the calculation is known as the apparent fracture toughness, K app , of the material. Because the crack length in the calculation of K c is usually longer, values for K c are usually higher than K app for a given material. Both of these measures of fracture toughness are expressed in the units ksiin. For tough materials, the numerical values generated by such tests generally increase as the width of the specimen increases or its thickness decreases.
It is to be appreciated that the width of the test panel used in a toughness test can have a substantial influence on the stress intensity measured in the test. A given material may exhibit a K app toughness of 60 ksiin using a 6-inch wide test specimen, whereas for wider specimens the measured K app will increase with wider and wider specimens. For instance, the same material that had a 60 ksiin K app toughness with a 6-inch panel could exhibit a higher K app , for instance around 90 ksiin, in a 16-inch panel and still higher K app , for instance around 150 ksiin, in a 48-inch wide panel test and still higher K app , for instance around 180 ksiin, with a 60-inch wide panel test specimen. Accordingly, in referring to K values for toughness herein, unless indicated otherwise, such refers to testing with a 16-inch wide panel. However, those skilled in the art recognize that test results can vary depending on the test panel width and it is intended to encompass all such tests in referring to toughness. Hence, toughness substantially equivalent to or substantially corresponding to a minimum value for K c or K app in characterizing the invention products, while largely referring to a test with a 16-inch panel, is intended to embrace variations in K c or K app encountered in using different width panels as those skilled in the art will appreciate. The testing typically is in accordance with ASTM E561 and ASTM B646 (both incorporated herein by reference).
Resistance to cracking by fatigue is a very desirable property. The fatigue cracking referred to occurs as a result of repeated loading and unloading cycles, or cycling between a high and a low load such as when a wing moves up and down or a fuselage swells with pressurization and contracts with depressurization. The loads during fatigue are below the static ultimate or tensile strength of the material measured in a tensile test and they are typically below the yield strength of the material. If a crack or crack-like defect exists in a structure, repeated cyclic or fatigue loading can cause the crack to grow. This is referred to as fatigue crack propagation. Propagation of a crack by fatigue may lead to a crack large enough to propagate catastrophically when the combination of crack size and loads are sufficient to exceed the material's fracture toughness. Thus, an increase in the resistance of a material to crack propagation by fatigue offers substantial benefits to aerostructure longevity. The slower a crack propagates, the better. A rapidly propagating crack in an airplane structural member can lead to catastrophic failure without adequate time for detection, whereas a slowly propagating crack allows time for detection and corrective action or repair.
The rate at which a crack in a material propagates during cyclic loading is influenced by the length of the crack. Another important factor is the difference between the maximum and the minimum loads between which the structure is cycled. One measurement including the effects of crack length and the difference between maximum and minimum loads is called the cyclic stress intensity factor range or ΔK, having units of ksiin, similar to the stress intensity factor used to measure fracture toughness. The stress intensity factor range (ΔK) is the difference between the stress intensity factors at the maximum and minimum loads. Another measure affecting fatigue crack propagation is the ratio between the minimum and maximum loads during cycling, and this is called the stress ratio and is denoted by R, a ratio of 0.1 meaning that the maximum load is 10 times the minimum load.
The crack growth rate can be calculated for a given increment of crack extension by dividing the change in crack length (called Δa) by the number of loading cycles (ΔN) which resulted in that amount of crack growth. The crack propagation rate is represented by Δa/ΔN or ‘da/dN ’ and has units of inches/cycle. The fatigue crack propagation rates of a material can be determined from a center cracked tension panel.
Still another technique in testing is use of a constant ΔK gradient. In this technique, the otherwise constant amplitude load is reduced toward the latter stages of the test to slow down the rate of ΔK increase. This adds a degree of precision by slowing down the time during which the crack grows to provide more measurement precision near the end of the test when the crack tends to grow faster. This technique allows the ΔK to increase at a more constant rate than achieved in ordinary constant load amplitude testing.
One way in which the improvements observed in the inventive alloy can be utilized by aircraft manufacturers is to reduce operating costs and aircraft downtime by increasing inspection intervals. The number of flight cycles to the initial or threshold inspection for a component depends primarily on the fatigue initiation resistance of an alloy and the fatigue crack propagation resistance at low ΔK, stress intensity factor range. The inventive alloy exhibits improvements relative to 2324-T39 in both properties which may allow the threshold inspection interval to be increased. The number of flight cycles at which the inspection must be repeated, or the repeat inspection interval, primarily depends on fatigue crack propagation resistance of an alloy at medium to high ΔK and the critical crack length which is determined by its fracture toughness. Once again, the inventive alloy exhibits improvements relative to 2324-T39 in both properties allowing for repeat inspection intervals to be increased.
An additional way in which the aircraft manufacturers can utilize the improvements in the inventive alloy is to increase operating stress and reduce aircraft weight while maintaining the same inspection interval. The reduced weight may result in greater fuel efficiency, greater cargo and passenger capacity and/or greater aircraft range.
BRIEF DESCRIPTION OF THE DRAWINGS
FIG. 1 shows a comparison of 2324-T39 plate with the properties of the inventive alloy.
FIG. 2 shows the S/N fatigue resistance improvement of the inventive alloy as compared with the 2324-T39 alloy as maximum stress is plotted versus cycles to failure.
FIG. 3 shows the increase in fatigue crack growth resistance of the inventive alloy as illustrated by the plot of da/dN versus ΔK.
FIG. 4 shows a plot of yield strength versus K app fracture toughness.
FIG. 5 is a phase diagram showing isothermal section plots of the Al—Cu—Mg system for the temperatures 910°, 920°, and 930° F.
DETAILED DESCRIPTION
FIG. 5 shows calculated isothermal section plots of the Al—Cu—Mg system for the temperatures 910° F. (488° C.), 920° F. (493° C.), and 930° F. (498° C.). Of these, only the 930° F. plot displays all the phase boundaries. The other phase boundaries have been omitted from the other isothermal lines for clarity and to better understand how the compositions of the 2000 series aluminum alloys were derived. The isothermal section shows the different phase fields that coexist at different temperatures and compositions of interest in this alloy system.
For example, for the 930° F. isothermal section, the composition regions of Mg and Cu are divided into four phase fields. These are the single phase aluminum matrix field (Al) bounded by the lines a and b to the left; the two-phase field consisting of Al and S (Al 2 CuMg) bounded by the lines a and c; the two-phase field consisting of Al and θ (Al 2 Cu) bounded by the lines b and d; and the three-phase field consisting of Al, S and θ bounded by the lines c and d.
These diagrams help to define a composition box or limitations of Cu and Mg and the ideal solution heat treatment (SHT) temperatures for an alloy composition that is positioned inside the single phase field of the Al matrix. FIG. 5 also shows that the Al single phase field shrinks progressively with respect to the Cu and Mg compositions as the temperature is lowered, as compared to 920° and 910° F. phase boundaries. This indicates that the solubility of the elements may be increased by treating the alloy at higher temperatures.
As recited above, it is important to confine the inventive compositions within the defined limitations of the isothermal plots so as to be inside the aluminum matrix single phase field. The compositions as shown in these plots are defined as effective compositions. The target compositions that make up the actual alloy can differ from the effective compositions since, at higher temperatures, a portion of the elemental composition of Cu is available to react with Fe and Mn and a portion of the elemental composition of Mg is available to react with Si, which are then not available for the intended alloying purposes. These amounts are to be made up by requisite extra additions to the effective composition levels required by the equilibrium diagram considerations as in the isothermal plots of FIG. 5 . For example, in reference to FIG. 5, the highest Cu for 1.45 Mg weight percent that remains within the single phase field at T max of 925° F. is a weight percent of 3.42 for Cu. This is defined as the effective Cu, or Cu eff , which will be the Cu available to alloy with Mg for strengthening. To account for the part of Cu that will be lost through reaction with Fe and Mn, the total Cu or Cu target , required is calculated from the following expression:
Cu target =Cu eff +0.74(Mn−0.2)+2.28(Fe−0.005)
Cu target =3.42+0.40=3.82
Note: This is for an Fe level of 0.05 and Mn=0.60
It is observed that a Cu target =3.85 weight percent is obtained at a T max =925° F. Accordingly, the overall composition target for this example at a 925° F. heat treatment is in weight percent: 0.02 Si, 0.05 Fe, 3.85 Cu, 1.45 Mg, 0.60 Mn, the remainder Al and incidental elements and impurities. This defines the “W” corner of the composition box in FIG. 5 .
As a second example, choosing a different Mg target of 1.35 weight percent and a T max equal to 920° F., the corresponding composition target is, in weight percent: 0.02 Si, 0.05 Fe, 3.92 Cu, 1.35 Mg, 0.60 Mn, the remainder Al and incidental elements and impurities. This defines the composition near the center of the composition box as a preferred target composition.
Just as a Mg target weight percent can be chosen to find the appropriate Cu target , it is possible to work such a determination in reverse, by choosing a Cu target to determine the amount of maximum Mg provided to the alloy composition. In this manner, a composition box for the preferred Cu and Mg combinations can be prepared for the cases with the maximum constant weight percents of 0.05 of Fe, 0.02 of Si and 0.6 of Mn. This has been superimposed on the Figure as the square box, defined by points W, X, Y, and Z. This composition box has a range of SHT temperatures between about 910° to 930° F.
Alloys within the W, X, Y, and Z box for a given SHT temperature can be selected so that little or no second phase particles should be present in the final alloy product.
To a certain extent, the above recited box can breathe. What is meant by this is that a small amount of boundary expansion can be effected by a decrease in the amount of silicon present, such as at less than 0.02, 0.03, or 0.04 weight percent. It is believed, although the inventors hereof do not want to be held to this belief, that by decreasing silicon to such minute levels, magnesium silicide as a reaction product is made in a de minimus amount or simply this reaction product is substantially inhibited. When this occurs, the incipient melting temperature increases above the lowest normal incipient melting temperature. That temperature increase allows a corresponding increase in solute concentration that will positively increase the important properties herein discussed. As a result of this decrease in the magnesium suicide reaction product, an increase in the maximum temperature attainable can be realized. The maximum temperature may be increased by about 1, 2, 3, 4, or 5° F. When this occurs, the box W, X, Y, Z expands beyond its boundaries by the above 1° to 5° F. temperature range.
By defining the composition limits by this iterative method, it was possible, upon appropriate processing, to achieve the desired strength goals. What is surprising, however, is that significant improvements in both fracture toughness and fatigue properties were also obtained without any strength compromise which have not been heretofore observed for this alloy group. Generally, when adjusting the composition of aluminum alloys as those skilled in this art appreciate, when one property gains, the usual circumstance is that another property suffers. Such is not the case under the present invention.
FIG. 1 provides a summary comparison of the properties of 2324-T39 to that of the present invention. It is noteworthy that K Ic , a measure of the plane strain fracture toughness, improved by 21.6 percent, K app , a measure of the plane stress fracture toughness, improved by 9.2 percent, S/N fatigue resistance improved by 7.7 percent and the fatigue crack growth rate decreased by 12.3 percent, a decrease in this last property defined as an improvement, all over the analogous properties of 2324-T39 alloy. None of the other properties were decreased in the inventive alloy yet significant increases are noted in four primary properties. In any event, in the invention hereof, the minimum improvement observed in each of the properties is over 5% or over 5.5% preferably over 6% or 6.5% and most preferably over 7% or even 7.5%, of 2324-T39 as a standard prior art alloy, while maintaining an essentially constant high level yield strength at the same temper.
FIG. 4 is a plot of K app fracture toughness versus yield strength. This is a measure of the fracture toughness for thin sections of alloy. The inventive alloy shows a marked increase fracture toughness over the comparison alloy without a negative effect on the yield strength. It is noticed that the sample batch of the inventive alloy appears to have established a higher band of properties for K app fracture toughness for this family of alloys.
The S/N fatigue curves of the inventive alloy and 2324-T39 are shown in FIG. 2 . The S/N fatigue curve of an alloy is a measure of its resistance to the initiation or the formation of a fatigue crack versus the applied stress level. The S/N fatigue curves for the inventive alloy and the 2324-T39 indicate that at a given stress level, more applied load cycles are required to initiate a crack in the inventive alloy than in 2324-T39. Alternatively, the inventive alloy can be subjected to a higher operating stress while providing the same fatigue initiation resistance as 2324-T39.
The fatigue crack growth curves of the inventive alloy and 2324-T39 are shown in FIG. 3 . The fatigue crack growth curve of an alloy is a measure of its resistance to propagation of an existing fatigue crack in terms of crack growth rate or da/dN versus the applied load expressed in terms of the linear elastic stress intensity factor range or ΔK. A lower crack growth rate at a given applied ΔK indicates greater resistance to fatigue crack propagation. The inventive alloy exhibits lower fatigue crack growth rates than 2324-T39 at a given applied ΔK in the lower and middle portions of the fatigue crack growth curve. This means that the number of applied load cycles needed to propagate a crack from a small initial crack or crack-like flaw to a critical crack length is greater in the inventive alloy than in 2324-T39. Alternatively, the inventive alloy can be subjected to a higher operating stress while providing the same resistance to fatigue crack propagation as 2324-T39.
One way in which the improvements observed in the inventive alloy can be utilized by aircraft manufacturers is to reduce operating costs and aircraft downtime by increasing inspection intervals. The number of flight cycles to the initial or threshold inspection for a component depends primarily on the fatigue initiation resistance of an alloy and the fatigue crack propagation resistance at low ΔK. The inventive alloy exhibits improvements relative to 2324-T39 in both properties which may allow the threshold inspection interval to be increased. For example, at low stress intensity factor range of ΔK=5 ksiin, da/dN for 2324 is 1.76×10 −7 in./cycle, while that for the inventive alloy is 1.26×10 −7 in./cycle, representing a decrease in the crack growth rate of 28%. The number of flight cycles at which the inspection must be repeated, or the repeat inspection interval, primarily depends on fatigue crack propagation resistance of an alloy at medium to high ΔK and the critical crack length which is determined by its fracture toughness. Once again, the inventive alloy exhibits improvements relative to 2324-T39 in both properties possibly allowing for repeat inspection intervals to be increased. For example, at medium stress intensity factor range of ΔK=14.3 ksiin, the crack growth rate da/dN for 2324 is 1.39×10 −5 in./cycle, and that for the inventive alloy is 9.37×10 −6 in./cycle representing a decrease in the crack growth rate of 33%. | The present invention is directed to highly controlled alloy composition relationship of a high purity Al—Mg—Cu alloy within the 2000 series aluminum alloys as defined by the Aluminum Association, wherein significant improvements are revealed in fracture toughness through plane strain, fracture toughness through plane stress, fatigue life, and fatigue crack growth resistance. | 2 |
This application is a continuation-in-part application of U.S. application Ser. No. 131,623 filed Dec. 10, 1987, and entitled "AIR CONDITIONER CHARGING STATION WITH SAME REFRIGERANT RETURN AND METHOD".
BACKGROUND OF THE INVENTION
The present invention relates to an automatic air conditioner charging station for charging refrigerant and oil into air conditioner systems, such as automobile air conditioner systems.
A number of apparatus have been provided for automatically charging such air conditioners. Among those are Proctor et al. U.S. Pat. No. 4,513,578 and Proctor U.S. Pat. No. 4,624,112. The former patent discloses an air conditioner charging station having a weighing scale on which are mounted reservoirs for oil and refrigerant, and an electronic sequencing unit, or microprocessor, which senses the weight loss of the reservoirs as first oil is charged into the air conditioner and then refrigerant is charged into the air conditioner, the amount of each which is charged into the air conditioner being determined by an operator entering into the computer the required amounts of oil and refrigerant for a particular air conditioner. Proctor U.S. Pat. No. 4,624,112 discloses a system of that general type, in which there is provided a conduit connecting the high and low pressure side conduits, called a cross-over conduit, and having a solenoid operated valve in it, together with a solenoid operated dump valve for dumping refrigerant and oil.
Sparano U.S. Pat. No. 3,232,070 conducts withdrawn refrigerant through a compressor and condenser, and then to a drier strainer, from which it is placed into a storage tank.
Taylor U.S. Pat. No. 3,699,781 provides a refrigerant recovery system in which the refrigerant gas is cooled in order to remove liquid by causing condensation in a coil, prior to introduction of the refrigerant into a drier.
Koser U.S. Pat. No. 4,285,206 discloses a system which is capable of simultaneously connecting a refrigerant recovery and purification apparatus to the air conditioner systems of two vehicles and includes a reclaim refrigerant tank mounted on a scale, and a tank for new refrigerant, one air conditioner system being recharged with reconditioned refrigerant while the other air conditioner system is having the refrigerant therein withdrawn for reclaiming.
Lower et al. U.S. Pat. No. 4,364,236 and Lower et al. U.S. Pat. No. 4,441,330 provide a system in which refrigerant is withdrawn from an air conditioner and passes through a particulate filter, an evaporator, an oil separator, a compressor, a condenser, and to a reservoir, and thence to a purifier, purified refrigerant from the reservoir being charged into an air conditioner being serviced; a microprocessor is used to effect the sequencing of the operations.
Goddard U.S. Pat. No. 4,476,688 discloses a refrigerant recovery and purification system in which refrigerant is withdrawn from an air conditioner and passed through an oil separator and a filter-drier by a compressor and into a receiving tank for the reclaimed refrigerant. The refrigerant is delivered from the reclaim tank, for charging into the air conditioner. A purge valve and a high pressure switch for a condenser are provided to bleed off air when air pressure in the condenser evaporator becomes excessive. Such excess pressure causes the compressor to be shut down.
Margulefsky et al. U.S. Pat. No. 4,480,446 provides a system for rehabilitating refrigerant including a filtering tank with a disc-shaped filter.
Taylor U.S. Pat. No. 4,646,527 provides a refrigerant recovery and purification system which includes a compressor and an oil separator, and accumulators having heat exchange coils in them, the recovered refrigerant being placed in a storage tank; in this system, distillation is utilized to separator oil and other impurities from the refrigerant.
Cain U.S. Pat. Nos. 4,261,178 and 4,363,222 disclose a refrigerant recovery system in which refrigerant is withdrawn and directed to a cylinder on a scale: there is also disclosed a separate system in which a pump produces a vacuum in a tank, which is then connected with an air conditioner in order to remove part of the refrigerant from it.
Staggs et al U.S. Pat. No. 4,539,817 provides a refrigerant recovery apparatus which includes a compressor and filters, and a storage tank.
Saunders U.S. Pat. No. 4,106,306 provides a charging apparatus for charging a refrigeration system of the type having a capillary tube, and discloses an electrical circuit for controlling the charging, which circuit receives data relating to indoor and outdoor temperature, to suction line temperature and to suction line pressure. There have been provided disclosures of a number of systems for diagnosing the operation or servicing of such air conditioners.
Motl U.S. Pat. No. 3,686,954 provides system for testing or diagnosing an air conditioner using solenoid valves actuated by manually operated switchers; the temperatures and pressures of the system are measured and readouts are provided by gauges.
Suzuki et al. U.S. Pat. No. 4,663,940 disclose a self-diagnostic apparatus for an automobile air conditioner which utilizes a microprocessor, input signals to which include sensing the position of dampers in air flow ducts. Also, of general interest are Hara U.S. Pat. No. 4,488,409 and Iida U.S. Pat. No. 4,688,389.
SUMMARY OF THE INVENTION
An air conditioner charging station or apparatus is provided in which refrigerant is withdrawn from an air conditioner, such as in an automobile, is reconditioned or reclaimed as by removing at least one of such extraneous or contaminant elements as oil, particles of metal, and there is returned to the air conditioner being serviced substantially only reclaimed refrigerant which is in the liquid state from that air conditioner. The apparatus includes conduits which are connected to the high pressure and low pressure sides of an air conditioner, there being in the apparatus, in series, a separator, a compressor, a condenser, and a reclaimed refrigerant cylinder or reservoir. There are also provided a reservoir containing new refrigerant, and a tank or reservoir of oil, all three tanks or reservoirs having means to measure the amount of material dispensed, such as a scale upon which they rest. To achieve the return of substantially only the same refrigerant, after it has been reclaimed, to the air conditioner from which it was withdrawn, the amount of reclaimed refrigerant delivered to or from the reclaimed refrigerant cylinder or reservoir has the quantity thereof measured, as by determining weight added, or lost by dispensing; refrigerant from the new make-up refrigerant cylinder is added to the charge to the air conditioner to the extent necessary, to make up a full charge. Pressure operated switches or transducers are provided at the high and low pressure sides of the compressor of the air conditioner, another at the outlet o the separator and another at the outlet of the compressor.
A solenoid valve is in the conduit connected to the high pressure side of the air conditioner, and is controlled by a circuit which includes the pressure operated switch at the high side of the compressor and by a control switch which forms a part of a microprocessor, so that where there is a suitably normal low pressure in the high pressure conduit, the solenoid valve is under the control of the microprocessor, but when a high pressure occurs in the high pressure side, the solenoid valve is removed from the control of the microprocessor and is caused to be closed.
A dump valve is provided for discharging to the atmosphere material such as non-condensable gases, which may have collected in the reclaim cylinder and/or in the condenser, the dump valve being connected to the inlet to the condenser. The reclaim cylinder or reservoir is located at a lower level than the condense,, so that such gases may rise from the reclaim cylinder to the top of the condenser, for eventual evacuation.
The reclaim cylinder reservoir is provided with a liquid refrigerant level sensor which sends a signal to close a valve controlling the outlet from the reclaim refrigerant reservoir to close it when the level of the liquid refrigerant in the reclaim reservoir has reached a predetermined low level.
The pressure switch at the inlet of the separator controls, through a microprocessor, the start-up of the compressor. A by-pass circuit is provided for by-passing high pressure refrigerant from the discharge side of the compressor to the inlet side of the compressor, for substantially equalizing the system compressor inlet and outlet pressures.
Among the objects of the present invention is the provision of an air conditioner charging station and method which removes and reconditions refrigerant, and returns to the air conditioner being serviced substantially only reclaimed refrigerant removed from that air conditioner. Another object is to provide an air conditioner charging station apparatus and method in which there is provided a recharging of an air conditioner with substantially only refrigerant in liquid state which has been removed from that air conditioner and reclaimed, and new refrigerant to the extent necessary to make up a full recharge.
Yet another object of the present invention is the provision of an air conditioner charging station or apparatus in which evacuation of non-condensable gases is readily achieved from both a receiver for reclaimed refrigerant and a condenser.
A still further object of the present invention is to avoid the discharge of refrigerant form the high pressure side of the air conditioner being serviced when an excess pressure exists in the high pressure side of the air conditioner, while enabling communication to and from the high pressure side of the air conditioner to be controlled by a microprocessor when the high pressure side of the air conditioner is at normal pressure.
Other objects and many of the attendant advantages of the present invention will be more readily understood from consideration of the following specification, claims and drawings.
BRIEF DESCRIPTION OF THE DRAWING
The single FIGURE of the drawing is a partly schematic and representational showing of a conventional air conditioner, and a charging station or system in accordance with the present invention.
DESCRIPTION OF THE PREFERRED EMBODIMENT
Referring now to the drawing, there is shown a conventional air conditioner generally designated 10, such as is typically used in automobiles. The air conditioner 10 includes a compressor 12 having a high pressure side from which fluid refrigerant is conducted by a high pressure conduit 14, which is connected to condenser 16. The discharge conduit 18 of condenser 16 may pass through a receiver-drier 20, and is connected to the inlet conduit 22 of evaporator 24 through expansion valve 26. Expansion valve 26 is controlled in known manner by a temperature sensing element 28 attached to the suction conduit 30 extending from evaporator 24 to the low pressure conduit 34 of compressor 12. The high pressure conduit 14 is connected to the high side of compressor 12 through high pressure conduit 36, and to the high pressure conduit 36 there is connected, through a detachable fitting (not shown) a conduit 42, forming a part of an air conditioner charging station; similarly, to the low pressure conduit 34 there is detachably connected a low pressure conduit 44 forming a part of the air conditioner charging station. The high pressure conduit 42 and the low pressure conduit 44 are of conventional construction having fittings at their ends which are attachable to corresponding fittings at the high pressure conduit 36 and the low pressure conduit 34, respectively, of the air conditioner 10. The high pressure conduits 42 and 44 also have, adjacent their ends, cut-off valves (not shown) which are provided to prevent the escape of freon refrigerant into the atmosphere upon detachment of the conduits 42 and 44 from the air conditioner 10.
A temperature transducer 32a for sensing the temperature of air entering the evaporator 24 is provided, as well as a temperature transducer 32b for sensing the temperature of air after it has passed through the evaporator 24. There is provided, also, a probe 12a for sensing the cycling of the clutch of the compressor 12.
A crossover conduit 46 is connected to the high pressure conduit 42 and the low pressure conduit 44, there being a solenoid operated crossover valve 48 therein controlled by a thermal transducer switch 50. A pressure operated switch or transducer 52 senses high side pressure, and is connected to a transformer 53, as is the solenoid valve 48. The pressure operated switch or transducer 52 is connected also to an electronic sequencing unit or microprocessor 100, a part of which is shown schematically near transducer or switch 52, and to the armature of a relay 55, the movable contact of which is connected to the solenoid operated crossover valve 48. Under normal conditions, when a suitable low pressure is sensed by the pressure operated switch or transducer 52, the solenoid operated crossover valve 48 will be connected to the microprocessor 100, and to the secondary transformer 53. When an excess pressure occurs in the high pressure conduit 42 and crossover conduit 46, the pressure operated switch or transducer 52 will be opened, thereby causing the relay 55 to shift so as to disconnect the solenoid operated crossover valve 48 from the micropocessor 100, the solenoid operated valve 48 thereby being energized and the valve portion of it being closed so as to close the crossover conduit 46 and prevent the fluid connected between the high pressure conduit 42 and low pressure conduit 44 through the crossover conduit 46. There is also provided a gauge 56 to show the high side pressure. A gauge 58 will sense and indicate the low side pressure. These gauges are electronically operated digital displays.
Thermal switch or transducer 50 senses ambient temperature and pressure switch or transducer 52 senses the pressure at the high side of the compressor 12, and is opened at a selected high pressure as above indicated; pressure in excess of the selected pressure, will cause the solenoid valve 48 to close, to stop the passage of refrigerant from the high side of the compressor until such time as the pressure falls below the selected amount. The solenoid valve 48 is also connected to the microprocessor 100 and receives command signals from it, as will be explained below. However, such command signals may be overridden by a signal from the thermal switch or transducer 50 if ambient temperature is below a predetermined level, such as 60° F.
The air conditioner charging station 40 further comprises a change of amount sensor, specifically a scale 60, which generates signals proportional to changes in weight of refrigerant and/or oil thereon an which is connected to the microprocessor 100. On the scale 60 are a reclaim reservoir 62 for reconditioned refrigerant, having an inlet 61 at the top end, an outlet 63 near the bottom connected to outlet conduit 64 which is connected through a solenoid valve 66 to an extension 44a of the low pressure conduit 44. A float 65 in the reclaim reservoir 62 will actuate a sensor and signal generator 67 in the bottom, which will cause solenoid valve 66 to close, to prevent gas from entering outlet or delivery conduit 64. A cylinder 68 for storing new make-up refrigerant is also on the scale 60 and may be provided with a heater 70. A conduit 72 connects the make-up refrigerant storing cylinder 68 to the low pressure conduit extension 44a through a solenoid valve 74 and a check valve 76 which prevents flow of fluid from conduit 44a into the cylinder 68.
Preferably, there is also on scale 60 oil storing cylinder 78, connected by conduit 80 to the low pressure conduit extension 44a through solenoid operated valve 82 and check valve 84. The low pressure conduit 44, 44a is connected through a check valve 86 and a solenoid valve 88 to a separator 90, for separating from gaseous refrigerant other components which may be in refrigerant withdrawn from the air conditioner 10, including oil, liquid refrigerant, and particles such as metal particles which may have come from bearings in the compressor 12. The separator 00, which is schematically shown, includes a cap 92 which may be a casting of a suitable strong metal, there being attached to it a bowl 94 which depends from it, and which is preferably transparent. Bowl 94 is held to the cap 92 by any suitable releasable holding means such as screw threads. The cap 92 is provided with a suitable hose connecting fitting for attachment to the conduit 44a, and has within it an inlet conduit 96 of angular shape, having an arm 96a which extends downwardly into bowl 94 and having its discharge outlet at a relatively low level. A post 98 depends downwardly rom the cap 92, and has thereon a float 102 which may be caused to rise on post 98 when oil and/or liquid refrigerant has risen to a sufficient height. The post 98 is hollow, and supports a sensor 104 which is engaged by float 102 when liquid in the bowl 94 has reached a certain height, engagement with sensor 104 causing a signal to be sent to microprocessor 100 through conductor 106. A plate 108 is mounted on the post 98, and serves to support dessicant, as may be provided in a small bag D, in the space within separator 90 which will always be above the level of liquid therein. As many bags D as necessary may be provided, and upon disassembly of the bowl 94 from the cap 92, the dessicant may be replaced.
A conduit 110 extends from the separator 90, and gaseous refrigerant leaving the separator 90 will pass through the desiccant and be dried. Because of the low temperature of the gaseous refrigerant above the liquid level in the separator 90, the dessicant will be at a relatively low temperature, and will operate therefore effectively.
Oil from the refrigerant removed from the air conditioner 10 will be caught in the bowl 94 of separator 90, rather than being discharged. There will also remain in the bowl 94 particles and liquid refrigerant. The oil may contain refrigerant which is dissolved in it. Since the separator 90 is subject to ambient temperature, that refrigerant may boil off, and be recovered. The utilization of a transparent bowl 94 will enable the operator to readily ascertain abnormal conditions relating to the oil in the refrigerant withdrawn from the air conditioner 10, such as whether there is no oil or too little oil, or an undue amount of oil. Thus, the operator would be able to ascertain that the air conditioner 10 has either an inadequate supply of oil or an over supply of oil, as the case may be. With this knowledge, he can check for the reason why the proper oil-to-refrigerant ratio in the air conditioner 10 is not within an acceptable range. The bowl 94 is preferably provided with a gauge, so that a determination can quickly be made whether the amount of oil removed from the refrigerant is within the normal range, and if so, can, upon recharging of the air conditioner 10, command the microprocessor 100 to restore the proper amount of oil to air conditioner 109 from the oil storage tank 78. Further, it will be seen that the discharge end of the conduit 96a is below the float 102, so that entering refrigerant will not impact on the float 102 and alter its normal operation. The float 102 will be lifted only by liquid within the bowl 94, and any foam which may be present in bowl 94 will not have a lifting effect on the float 102, so that thereby a true sensing of the liquid level in bowl 94 may be obtained by the sensor or switch 104.
The conduit 110 which extends from the separator 90 has a pressure switch 112 connected to it, for sensing the pressure within the separator 90. A check valve 114 is included in the conduit 110 to prevent backflow of liquid or pressure into the separator 90. The placement of the check valve 114 in the conduit 110 is preferred, although check valve 114 may be either eliminated, or replaced by a solenoid valve.
Gaseous refrigerant from the separator 90 is delivered by the conduit 110 to a compressor 116 which is driven by a motor 118, the power to which is supplied through a solenoid switch 120. The compressor 116 is of a known type, capable of drawing refrigerant from the air conditioner 10 through the separator 90, and compressing the received refrigerant, which is gaseous. A conduit 122 serves to conduct compressed refrigerant from the compressor 116, and has connected to it a by-pass conduit 124 which extends from the conduit 122 to the conduit 110, having a solenoid operated valve 126 therein. As shown by the symbol adjacent to solenoid valve 126, it will be opened by an overpressure from the conduit 110, but an overpressure from conduit 122 will not open it, so that only when solenoid valve 126 is opened through energization of the solenoid will it be opened and refrigerant be permitted to flow through the by-pass conduit 124.
A solenoid operated dump valve 128 is connected to the conduit 122, and there is provided in the conduit 122 a solenoid operated control valve 130. Also in conduit 122 is a pressure switch 132.
Conduit 122 delivers reclaimed, purified and compressed refrigerant to the condenser 136 which is diagrammatically illustrated as comprising a coil; a fan 138 driven by a motor 140 may be caused to blow air across the condenser 134. The condensed refrigerant is delivered through conduit 142 having a solenoid valve 144 therein to the reclaim reservoir 62, the conduit 142 extending downwardly because the reclaim reservoir 62 is located at a lower level than the condenser 134, the conduit 142 entering the upper part of the reclaim reservoir 62.
In operation, the conduits 42 and 44 are connected to the air conditioner 10, and it is assumed that the solenoid valve 48 is closed when the air conditioner charging station 40 is turned on and current lows through the solenoid of solenoid valve 48; it is opened by microprocessor 100 only when charging refrigerant from either the reclaim reservoir 62 or make-up cylinder 68, or when dumping the charge of air conditioner 10, unless it is closed when the sensing of abnormal temperature by the thermal switch or transducer 50 or upon the sensing of abnormal pressure by the pressure switch or transducer 52. The solenoid valve 88 will be closed, and if the pressure switch 112 which senses the pressure in conduit 110 connecting the separator 90 with the compressor 116 is in the range of 15 to 20 pounds per square inch, pressure switch 112 will cause motor 118 and compressor 116 to be activated. When the pressure falls to approximately 0 psig, solenoid switch 120 will be opened, and the compressor 116 will stop. However, the signal from switch 112 passes through a microprocessor 100 to the solenoid switch 120 (or its equivalent) and under certain circumstances, the signal from pressure switch 112 may be overridden or by-passed so that, for example, when it is necessary to have the compressor pull a vacuum on the air conditioner 10, this may be effected by the overriding or bypassing by the signal from pressure transducer 112.
The purpose of the by-pass conduit 124 is to equalize the high and low pressure sides of the compressor 116 since known air conditioner compressors cannot start if there is differential between the low pressure side and the high pressure side which is too great. A compressor without such limitation would not need the by-pass conduit 124. The pressure on the high pressure side of the compressor 116 is sensed by the pressure switch 132 and the pressure on the low pressure side of the compressor 116 is sensed by the pressure switch 112, the signals from these switches being delivered to the microprocessor 100 for processing, and the controlling of the valve 126, to open it, to thereby permit the equalization of the pressures on the high and low pressure sides of compressor 116; when the microprocessor 100 causes the solenoid valve 166 to be opened, to unload the compressor 116, the dump solenoid valve 128 and the solenoid valve 130 in the conduit 122 are both closed. The result is that only a small volume of refrigerant flows from the high pressure side of compressor 116 to the low pressure side, and there is not introduced into the conduit 122 refrigerant from the condenser 136. When the compressor 116 is not being unloaded, the by-pass solenoid valve 126 is closed and the solenoid valve 130 in the conduit 122 to condenser 136 will be opened. When compressor 116 is restarted, control solenoid valve 130 is opened shortly after bypass valve 126 closes.
In overall operation, the compressor 116 withdraws refrigerant from the air conditioner compressor 12, the refrigerant flowing through the separator where oil, particles such as metal particles, and liquid refrigerant are removed, with reconditioned gaseous refrigerant then flowing to compressor 116 where it is compressed and delivered to the condenser 136, where it is condensed, and caused to flow into the reclaim reservoir 62 for the withdrawn and reconditioned refrigerant. That withdrawn, reconditioned refrigerant will pass to the compressor 12 of the air conditioner 10 upon the opening of solenoid valve 66 and the closing of the solenoid valve 144 in the conduit 142 leading to the intake of the reclaim reservoir 62. Thus, there will be returned to the compressor 12 from the reclaim reservoir 62 substantially only refrigerant which was withdrawn from compressor 12. In this way, any contamination which may be present in the refrigerant from one air conditioner system 10 in one automobile will not be mixed with refrigerant from another automobile, so that there is thereby avoided the transfer of contaminants from one air conditioner system to another. Thus, substantially only the same reconditioned refrigerant is returned to the air conditioner from which it is withdrawn, and, with the following exception, no refrigerant from another air conditioner is placed into the air conditioner being serviced. That exception is that a very small amount of refrigerant from a servicing operation on one vehicle air conditioner may remain in the condenser 136, and that a very small amount will be delivered to the reclaim reservoir 62 upon the initiation of servicing of a second air conditioner of a second automobile. However, that amount of refrigerant is so small that any contamination will be negligible, due to the extremely small amount of contaminant that may be delivered into the air conditioner of the second vehicle.
When reclaimed refrigerant is being delivered from the reclaim reservoir 62, should the liquid level fall to a predetermined level, the float 65 will activate the sensor 67, which will then send a signal to the solenoid valve 66 to prevent further discharge of refrigerant from the reclaim reservoir 62. This occurs when the level of reclaimed liquid refrigerant in the reclaim reservoir 62 is above the outlet 63, so that there is thereby prevented the entry of gaseous reclaimed refrigerant into the outlet conduit 64 and into the air conditioner 10.
If during operation the float 102 rises and strikes the sensor 104, a signal by way of conductor 106 to the microprocessor 100 causes the circuit to motor 118 to be broken, and compressor 116 will stop. There is provided a transparent switch button 115 with a light behind it which flashes at this time, there being provided adjacent to it a legend that the lighted button is to be depressed. Depression of this lighted button-switch will cause the microprocessor to close the solenoid valve 88 and to cause the compressor 116 to operate, to reduce the pressure within the separator 90, the solenoid valve 88 preventing the addition of more freon to separator 90; when the pressure in separator 90 is satisfactorily reduced to approximately 0 psig, this will be sensed by the switch 112, which will provide a signal to microprocessor 100, which will then shut down compressor 116. After that, the bowl 94 may be removed from the cap 92, the bowl emptied and cleaned, and the dessicant bag D replaced.
In some instances a part of the normal refrigerant charge of a particular air conditioner may have leaked out, so that the amount of withdrawn, reconditioned refrigerant delivered to the reclaim reservoir 62 is not sufficient to provide a complete charge for the air conditioner being serviced. To provide a complete charge, the amount of the deficiency is determined, as explained hereinbelow, and the necessary amount of refrigerant to provide a full charge is withdrawn from the make-up refrigerant cylinder 68. Thus, the air conditioner 10 will receive a full charge made up of one or a first component, which is the same refrigerant that was withdrawn from the air conditioner 10, and which was reconditioned by the separator 90, and to the extent necessary, a second component of new refrigerant from the make-up cylinder 68. As is known, a small amount of oil is usually introduced into the air conditioner during recharging, and this is provided from the oil storage tank 78, through conduit 80 when the solenoid valve 82 is opened.
Returning to the single FIGURE, the dump solenoid valve 128 is provided to permit dumping of material to atmosphere. That material may be non-condensible gas, which in most cases is air, which may have been contained in the withdrawn refrigerant. That air would be located in the upper or higher part of the condenser 136, at and near the inlet thereof. This non-condensible gas, or air, would have risen from the liquid refrigerant in the coils of the condenser 136 to the highest part of the condenser coil, liquid being of higher density being in the lower part of the coil of condenser 136. With the compressor 116 stopped, the solenoid by-pass valve 126 will be closed, the condenser valve 130 will be opened, and the dump valve 128 will be opened. Since the condenser 136 is at a higher elevation than the reclaim reservoir 62, any gas which will have accumulated in the reclaim reservoir 62 will, with solenoid valve 144 opened, pass upwardly to and through the condenser coil 136, since the reclaim reservoir 62 is below the condenser 136; that non-condensible gas, or air, will thus also be exhausted from the apparatus through the dump solenoid valve 128. This will avoid the incorporation of non-condensible gas, such as air, in the refrigerant which is returned to the air conditioner 10 which is being serviced.
Purging occurs when an excessive pressure, which may be approximately 325 psig, is sensed by the pressure switch 132. When this level of pressure is sensed, the compressor 116 is stopped, by interrupting the flow of current to the motor 118, and after a time delay, the microprocessor 100 causes the condenser solenoid valve 130 and the dump solenoid valve 128 to open to permit the above described dumping function. The pressure build-up in the condenser 136 will be caused, for example, when the reclaim reservoir 62 is substantially full, when it may contain some air, together with the withdrawn and reconditioned refrigerant in the liquid state. When the reclaim reservoir 62 is full, no more refrigerant can be pumped into it, so that continued operation of the compressor 116 will cause the noted rise in pressure. Also, if the reclaim reservoir 62 is substantially full, and the temperature rises, the refrigerant in the reclaim reservoir 62 will expand, and since the solenoid valve 66 in the outlet conduit 64 is closed, refrigerant must flow out of reclaim reservoir 62 to the condenser 136. This is permitted by the solenoid valve 144 which permits an override as indicated by the symbol adjacent to it, the higher pressure in the reclaim reservoir 62 forcing the valve off of its seat and refrigerant and/or air passing upwardly to the coil of condenser 136. Valve 44 is normally open, except when the apparatus 40 is dispensing oil or refrigerant. The condenser 136 will have part of its coil or coils filled with liquid, but also part thereof will be filled with high pressure gas. For this reason, there is space in the condenser 136 to accept overflow liquid refrigerant from the reclaim reservoir 62. Any gas, as above-explained, will rise upwardly to the top portion of the coil or coils of accumulator 136, and be adjacent the inlet, and will be discharged, as above indicated, during the dumping phase.
When the air conditioner 10 has been charged, as above indicated, the high pressure conduit 42 and the low pressure conduit 44 are disconnected from the air conditioner 10. Valves in the ends of these conduits near the connection fittings are closed, to prevent escape of refrigerant into the atmosphere. In some instances, this will occur at the end of a day's work, when temperatures might be somewhat lower. Should the ambient temperature rise, the refrigerant in the conduits 42 and 44 would expand. Rupturing of the conduits, particularly conduit 42, is avoided by the provision of the crossover solenoid operated valve 48, which is open when there is no current flowing in the solenoid thereof, and this occurs automatically when the power of the charging station 40 is turned off. Consequently, when the charging station 40 is turned off, as at the end of the day, the solenoid operated crossover valve 48 will not be energized, the valve of solenoid operated crossover valve 48 will be open, and refrigerant will be able to flow from the high pressure conduit 42 through the crossover conduit 46 and into the conduits 44, 44a, thereby avoiding an undesirably high increase of the pressure in the conduits of the charging station 40, and thus avoiding any chance of rupture of hoses from excess pressure within any of the conduits of charging station 40, and particularly of the high pressure conduit 42.
The claims and the specification describe the invention presented, and the terms that are employed in the claims draw their meaning from the use of such terms in the specification. Some terms employed in the prior art may be broader in meaning than specifically employed herein. Whenever there is a question between the broader definition of such term as used in the prior art and the more specific use of the term herein, the more specific meaning is meant. | An air conditioner charging station withdraws refrigerant from an air conditioner, reclaims it by removing certain materials, and returns the reclaimed refrigerant to the same air conditioner from which it was withdrawn, and also provides preselected commands upon receipt of signals indicating conditions of temperature, pressure, etc. The reclaimed refrigerant is deposited into a reservoir, which contains a float that cooperates with a level sensor and signal generator to send a signal when the liquid level has reached a predetermined position. This signal causes a valve in the discharge line from the reservoir to close, to prevent discharge of gas from the reservoir. The charging station includes a high pressure conduit and a low pressure conduit which are attached to the air conditioner to be serviced, there being a crossover conduit between them with a solenoid valve in it; the solenoid valve is controlled by a pressure switch sensing pressure on the high pressure side, and the microprocessor, the parts being connected through a relay such that when an excess of pressure occurs, the relay is shifted so as to by-pass the microprocessor to maintain the solenoid valve energized, with the valve thereby being closed. | 5 |
FIELD OF THE INVENTION
[0001] This invention relates to hybrid electric motor vehicles and in particular to a strategy for managing the state of charge (SOC) of a high-voltage battery pack in such a vehicle.
BACKGROUND OF THE INVENTION
[0002] A hybrid electric vehicle can operate with significantly greater fuel economy in comparison to a corresponding vehicle that is propelled only by an internal combustion engine. Fuel economy improvements of 30% or greater are not uncommon. The cost of hydrocarbon fuels like diesel fuel have prompted some commercial truck users to explore the potential benefit that a hybrid electric vehicle might offer for their particular businesses.
[0003] For example, a business, such as an electric utility, that needs to operate electric devices like power tools at remote job sites might consider purchasing a hybrid electric vehicle that can deliver exportable AC power. A different business, such as a frozen or refrigerated food delivery company, may consider purchasing a hybrid electric vehicle having a body with a refrigeration system, with the refrigeration system operated by a compressor using on-board AC power while the vehicle is being driven. Such a vehicle can operate over an extended delivery area in comparison to a refrigerated truck that employs a cold plate technology where the refrigeration system resides in the truck body but operates only when the vehicle is parked and the refrigeration system is plugged into an electric outlet, typically at night. Delivery route time for the latter truck is limited by the length of time for which the cold plate is able to maintain the frozen or refrigerated goods at the proper temperature.
[0004] A plug-in hybrid electric vehicle (PHEV) provides a capability that allows the owner/operator to plug the vehicle's electrical system into the electric utility grid to charge the high-voltage hybrid battery pack. This is normally done during nighttime, when there is typically an excess of AC electricity available on the grid and the price per kilowatt-hour is typically at its lowest. In order to make a PHEV most effective, it should have greater battery energy storage capacity than its non-plug-in hybrid counterpart.
SUMMARY OF THE INVENTION
[0005] Insofar as the inventor is aware, current hybrid electric vehicles are built to have only one battery management strategy. Such a single strategy doesn't allow the operator (driver) to select a different strategy that would be more suited to the intended use of the vehicle on a particular day.
[0006] The inventor believes that the owner/operator of a PHEV that is driven in different ways at different times over different drive cycles should be able to choose how and when to consume the electric energy that re-charged the PHEV battery pack while the vehicle was parked. If the vehicle is being operated with a “Maintain Charge To Job Site” strategy, that is a feature of the invention to be described, the high-voltage control module will allow some limited use of the motor/generator for propulsion and regeneration while driving, while striving to maintain battery SOC somewhere between 75-95%, depending on the specific battery capacity and battery chemistry. Maintaining this relatively high level SOC allows for the recapture of kinetic energy when the vehicle is braking, while saving most of the battery energy for job site or on-board equipment operation. If, on the other hand the vehicle is being operated with a “Maximize Fuel Economy” battery pack management strategy, that is also a feature of the invention to be described, the high-voltage control module will allow the motor/generator to provide a greater proportion of vehicle propulsion energy and battery pack SOC will be maintained at a lower level—probably 25-65%, again depending upon specific battery capacity and battery chemistry.
[0007] The present invention utilizes a software algorithm for determining the particular strategy by which the controller will manage battery pack SOC but always gives the driver the opportunity to make his/her own selection instead. The algorithm causes one of two strategies, either the “Maximize Fuel Economy” or the “Maintain Charge To Job Site”, to be automatically selected each time that the vehicle's ignition switch is operated from “off” position to “on” position.
[0008] However, the manner in which the algorithm executes depends on the value of a calibratable parameter electronically programmed in the control module of the particular vehicle when the vehicle is being built at the factory. The calibratable parameter determines a specific branch of the algorithm that will be executed each time the ignition switch is turned from “off” to “on”.
[0009] When the ignition switch is operated from “off” to “on” in preparation for a drive cycle, the driver is given the opportunity to make a selection of “Maximize Fuel Economy” or “Maintain Charge To Job Site” (other similar terms may be used instead) on the display portion of an instrument panel module that has a momentary contact switch along side the display. The driver then has the ability to change the automatic selection (i.e., the default selection) by pressing the momentary contact switch along side the display, if he/she chooses to do so. Hence, when the vehicle's ignition switch is operated from “off” to “on”, the present invention gives the owner/operator of a PHEV the ability to select how the stored battery pack energy will be used, if he/she wishes to do so, regardless of what strategy the controller has been programmed to select.
[0010] Giving the driver an opportunity to effectively override what amounts to a default battery management strategy selection by an algorithm affords a choice of either using a significant portion of the stored energy for vehicle propulsion purposes or conserving a significant portion of the stored energy for job site or on-board equipment (such as a refrigeration compressor) operation. For instance when the “Maintain Charge To Job Site” strategy is the default mode of operation after the ignition switch has been operated from “off” to “on”, the operator can select “Maximize Fuel Economy” before returning to home base so that the vehicle operates with better fuel economy. Providing flexibility in selecting a battery pack SOC management strategy enables the vehicle owner/operator to use stored battery energy in a way that he/she deems best.
[0011] One value for the calibratable parameter will cause the algorithm to execute in a manner that sets the battery management strategy to the strategy that was in effect when the vehicle was last shut down. The driver can however still make his/her own selection.
[0012] Another value for the calibratable parameter will cause the algorithm to execute in a manner that sets the battery management strategy to “Maintain Charge To Job Site” after the battery pack has received a maximum plug-in charge (SOCPlug-in>KWHMin, a predetermined value in the algorithm), or if the “Maintain Charge To Job Site” strategy had been in effect prior to last turning the ignition switch from “on” to “off”. Again the driver can still make his/her own selection.
[0013] For instance, if the vehicle frequently travels to job sites where power tools are used and the normal mode of operation is to re-charge the battery pack overnight, the operator might not normally override the strategy set by the algorithm in order to maintain high SOC upon arrival at the job site. On the other hand, if the operator is not going to a job site where exportable electric power will be required on a given day, fuel efficiency may be optimized by manually selecting “Maximize Fuel Economy”.
[0014] Specifics for the battery charging algorithm depend on the specific battery chemistry (NiMH, Li-ion, etc) and battery capacity (KW-Hr) in any given vehicle.
[0015] One generic aspect of the present invention relates to a hybrid electric vehicle comprising a chassis comprising wheels on which the vehicle travels and a powertrain coupled to driven ones of the wheels. The powertrain comprises an internal combustion engine having a rotary output coupled to a rotary input of an electric motor/generator that has a rotary output coupled to the driven wheels. The vehicle also has an ignition switch that when operated to an “on” position enables the powertrain to propel the vehicle and when operated to an “off” position shuts down the powertrain.
[0016] A battery pack is coupled to the motor/generator through a controller for selectively operating the motor/generator as a motor that draws electricity from the battery pack to add torque to the powertrain and as a generator that delivers electricity to the battery pack to subtract torque from the powertrain when a management strategy for the battery pack allows such operation.
[0017] The controller is selectively operable to any of multiple strategies for managing the battery pack via an algorithm that, when the ignition switch is operated from “off” to “on”, operates to select a particular battery pack management strategy according to a calibratable parameter that, for the vehicle, has been set to a particular one of multiple values.
[0018] A first of the calibratable parameter values is effective to cause the algorithm to set the battery pack management strategy to the same battery pack management strategy that was in effect when the ignition switch was last operated from “on” to “off”. A second of the calibratable parameter values is effective to cause the algorithm to set the battery pack management strategy to a strategy that is determined by the number of times that the ignition switch has been operated from “off” to “on” since the last re-charging of the battery pack from a source external to the vehicle.
[0019] A further generic aspect of the invention relates to a method of operating a vehicle as described above. When the ignition switch is operated from “off” position to “on” position, an algorithm selects a strategy for managing the battery pack according to a calibratable parameter that, for the vehicle, has been set to a particular one of multiple values, a first of the calibratable parameter values being effective to cause the algorithm to set the battery pack management strategy to the same battery pack management strategy that was in effect when the ignition switch was last operated from “on” position to “off” position, and a second of the calibratable parameter values being effective to cause the algorithm to set the battery pack management strategy to a strategy that is determined by the number of times that the ignition switch has been operated from “off” position to “on” position since the last re-charging of the battery pack from a source external to the vehicle.
[0020] Still another generic aspect relates to a hybrid electric vehicle comprising a chassis comprising wheels on which the vehicle travels, a powertrain coupled to driven ones of the wheels, and an ignition switch that when operated to an “on” position enables the powertrain to propel the vehicle and when operated to an “off” position shuts down the powertrain. The powertrain comprises an internal combustion engine having a rotary output coupled to a rotary input of an electric motor/generator that has a rotary output coupled to the driven wheels.
[0021] A battery pack is coupled to the motor/generator through a controller for selectively operating the motor/generator as a motor that draws electricity from the battery pack to add torque to the powertrain and as a generator that delivers electricity to the battery pack to subtract torque from the powertrain when a management strategy for the battery pack allows such operation.
[0022] The controller is selectively operable to any of multiple battery pack management strategies via an algorithm that, when the ignition switch is operated from “off” position to “on” position, operates to cause the battery pack management strategy to default to one of the battery pack management strategies.
[0023] A selection input to the controller allows a person, instead of the algorithm, to select a battery pack management strategy for use by the controller different from the default strategy determined by the algorithm when the ignition switch was operated from “off” position to “on” position.
[0024] The foregoing, along with further features and advantages of the invention, will be seen in the following disclosure of a presently preferred embodiment of the invention depicting the best mode contemplated at this time for carrying out the invention. This specification includes drawings, now briefly described as follows.
BRIEF DESCRIPTION OF THE DRAWINGS
[0025] FIG. 1 is a general schematic diagram of portions of a hybrid electric vehicle relevant to an understanding of principles of the present invention.
[0026] FIG. 2 shows more detail, including a module containing a display, related to a portion of FIG. 1 .
[0027] FIG. 3 shows an algorithm for setting battery pack management strategy.
[0028] FIG. 4 shows the module of FIG. 2 , but with the display presenting different information than in FIG. 2 .
[0029] FIG. 5 shows the module of FIG. 2 , but with the display presenting different information than in either FIG. 2 or FIG. 4 .
DESCRIPTION OF THE PREFERRED EMBODIMENT
[0030] FIG. 1 shows a portion of a hybrid electric vehicle 10 relevant to an understanding of principles of the present invention. The specific vehicle is a PHEV.
[0031] PHEV 10 is shown, by way of example, as a rear wheel drive type vehicle that comprises a powertrain 12 in which a crankshaft of an internal combustion engine 14 is coupled via a rotor of a rotary DC electrical machine (i.e. motor/generator) 16 to an input of a transmission 18 . An output of transmission 18 is coupled via a driveshaft 20 to a differential 22 of a rear axle 24 having wheels 26 attached to outer ends of respective shafts. Principles of the invention can be applied to various vehicle drivetrain configurations other than a rear wheel drive configuration.
[0032] An engine control module 28 is associated with engine 14 for controlling various aspects of engine operation based on various inputs to module 28 . The inputs are not specifically shown.
[0033] PHEV 10 also comprises a low-voltage electrical system based on 12 and/or 24 VDC power. PHEV 10 further comprises a high-voltage electrical system based on DC voltage in a range from 300 VDC to 600 VDC.
[0034] The low-voltage system comprises a DC battery pack 30 that comprises one or more D.C. storage batteries. The high-voltage system comprises a DC battery pack 32 that comprises one or more batteries.
[0035] Collectively, the high- and low-voltage systems supply the electric power needs of various electrical accessories and devices in the vehicle.
[0036] The high-voltage system further comprises a high-voltage control module 34 whose primary purpose is to interface battery pack 32 and motor/generator 16 so as to provide for the battery pack to operate motor/generator 16 at times when it is appropriate for stored electrical energy to be used either in whole or in part to propel PHEV 10 via powertrain 12 . Module 34 also has respective channels of communication 36 , 38 with engine control module 28 and battery pack 30 respectively.
[0037] On an instrument panel inside an occupant compartment of PHEV 10 is a module 40 , shown in more detail by itself in FIGS. 4 and 5 , that comprises a push-button operated switch 42 and an electronic display 44 .
[0038] FIG. 1 shows a plug 46 that can be plugged into a receptacle (not shown) on an electric power grid that provides AC voltage, such as from a commercial electric utility company. When plug 46 is connected to the grid, alternating current drawn from the grid can be converted by conventional AC to DC conversion in module 34 into direct current for re-charging battery pack 32 .
[0039] PHEV 10 also has a high-voltage power inverter 48 that can convert electric energy stored in battery pack 32 into one or more AC voltages, such as the representative ones shown in FIG. 1 . Such voltages can be used to operate various electric power tools and devices at a job site. Inverter 48 interfaces with battery pack 32 through module 34 which provides the proper control and functionality for enabling inverter 48 to be operated by current from the battery pack when such tools and devices are used. Not shown in FIG. 1 is a DC to DC converter, that can be additional to or in place of inverter 48 , for converting the high-voltage DC of battery pack 32 into a lower DC voltage or voltages for use by other electric tools and devices that operate on DC rather than AC electric power. Such a converter would also interface with the battery pack through module 34 .
[0040] When the ignition switch is turned from “off” to “on”, the high-voltage battery pack management strategy is automatically placed in one of the two strategies, namely the “Maximize Fuel Economy” strategy or the “Maintain Charge To Job Site” strategy. The vehicle is considered to be operating in the “Maintain Charge To Job Site” mode when the algorithm or driver has selected the “Maintain Charge To Job Site” strategy, and in the “Maximize Fuel Economy” mode when the algorithm or driver has selected the “Maximize Fuel Economy” strategy. The particular strategy that is being used appears on display 44 . In FIG. 2 the strategy that is in place is shown on display 44 as “Maximize Fuel Economy”.
[0041] Switch 42 provides for the operator of PHEV 10 to change the strategy by pressing its push-button actuator. FIG. 4 shows the strategy having been changed to the “Maintain Charge To Job Site” strategy.
[0042] When the ignition switch is turned from “off” to “on”, the particular strategy in which battery pack management is placed is a function of a calibratable parameter that was programmed into module 34 at the time of PHEV build. The calibratable parameter can assume any one of several different values, given here by way of example as “1” and “2”.
[0043] If the calibratable parameter has been set to “1”, then the management strategy assumes the strategy that was in place when the ignition switch was last turned off regardless of whether the battery pack has or has not received a plug-in re-charge.
[0044] If the calibratable parameter has been set to “2”, then the algorithm automatically selects, i.e. defaults to, the “Maintain Charge To Job Site” strategy if this is the first time that the ignition switch has been operated from “off” to “on” after the battery pack received a plug-in re-charge. If this is not the first time that the ignition switch has been operated from “off” to “on” after a plug-in re-charge, then the algorithm selects as the default strategy the strategy that was in effect when the ignition switch was last turned off.
[0045] The “Maximize Fuel Economy” strategy preferably includes an “Adaptive Learning Feature” that serves to tailor the “Maximize Fuel Economy” in accordance with how PHEV 10 is being actually being driven. An adaptive learning algorithm in a processor of module 34 monitors various parameters, such as SOC of battery pack 32 , elapsed vehicle operating time, amount of battery pack re-charging by regenerative braking battery re-charging, and distance traveled, to dynamically update the battery pack re-charging strategy.
[0046] For example if PHEV 10 is being operated in a manner mostly at lower speeds with frequent starting and stopping (accel and decel), the adaptive learning algorithm allows relatively greater battery discharge (measured by SOC) so that more regenerated electrical energy from the battery pack is used for acceleration so as to thereby maximize fuel efficiency. On the other hand, if the PHEV is operating mostly at highway cruising speed with only occasional decelerations, the algorithm causes the battery pack SOC to be maintained at an established relatively higher SOC that allows the battery pack to recover energy during occasional decelerations but to supply electrical energy for propulsion when battery SOC reaches the established relatively higher limit.
[0047] FIG. 3 shows an algorithm 50 that uses the calibratable parameter feature. The algorithm executes when the ignition switch is operated from “off” to “on”.
[0048] If the calibratable parameter was set to “1”, the battery pack management strategy defaults to whatever the previous strategy was when the ignition switch was turned off, as shown by a step 52 . The default strategy is made known to the vehicle operator on display 44 . The operator has the opportunity to change the strategy at any time by operating switch 42 to select the other strategy. A step 54 monitors for such a change.
[0049] If no change is selected, a step 56 maintains the current strategy. If a change is selected, a step 58 causes the newly selected strategy to manage the battery pack.
[0050] After the occurrence of either step 56 or 58 , a step 60 checks the status of the ignition switch. As long as the ignition switch remains on, the algorithm continues to loop back to step 54 . Switching back and forth from one strategy to the other is possible as long as the ignition switch remains on.
[0051] When step 60 detects that the ignition switch has been turned off, the strategy that is being used at that time becomes the default when the ignition switch is next turned on. Execution of the algorithm is discontinued while the ignition switch is off.
[0052] If the calibratable parameter was set to “2”, the algorithm performs a step 62 upon the ignition switch being turned on. The purpose of step 62 is to determine if this is the first time that the ignition switch has been turned on after battery pack 32 has been re-charged from the utility grid (i.e., after plug-in re-charge). If it is the first time, then the battery pack management strategy defaults to the “Maintain Charge To Job Site” strategy that is shown at step 64 and alternately named in the Figure as “Maintain Battery SOC for Job Site or On Board Equipment”.
[0053] The driver is allowed to change the strategy in the same way as when the calibratable parameter was set to “1”, by a series of steps 68 , 70 , 72 , 74 , corresponding to steps 54 , 56 , 58 , 60 .
[0054] However, if step 62 determines that this is not the first time that the ignition switch has been turned on since the last plug-in re-charge, then a step 65 is performed to determine if the strategy that was in effect when the ignition switch was last turned off was the “Maintain Charge To Job Site” strategy.
[0055] If it was, then that same strategy continues, while steps 68 , 70 , 72 , and 74 allow the driver to change it at any time.
[0056] If it wasn't, then a step 66 causes the battery management strategy to default to the “Maximize Fuel Economy” strategy, with steps 68 , 70 , 72 , and 74 still allowing the driver to change to the “Maintain Charge To Job Site” strategy at any time. In this way, the strategy defaults to the one that was in effect when the ignition switch was last turned off, unless there was an intervening plug-in re-charge in which case the strategy defaults to the “Maintain Charge To Job Site” strategy.
[0057] Once the strategy has been set by either step 64 or step 66 , it always remains possible for the operator to change it in the same way as when the calibratable parameter was set to “1”.
[0058] If the particular strategy on display 44 isn't changed by the driver within a certain amount of time, the display defaults to a screen that presents battery pack SOC information, such as in the graphical manner shown in FIG. 5 where the level is indicated by a highlighted amount between Minimum and Maximum. If the driver press the actuator of switch 42 , the display returns to the screen that shows the current strategy. Pressing the switch actuator while this screen is being displayed will change the strategy while the strategy will remain unchanged if the actuator isn't pressed. Failure to press the actutor within a certain amount of time will result in the screen returning to the one shown in FIG. 5 .
[0059] While a presently preferred embodiment of the invention has been illustrated and described, it should be appreciated that principles of the invention apply to all embodiments falling within the scope of the following claims. | A software algorithm (FIG. 3 ) determines the strategy by which a controller ( 34 ) will manage state of charge (SOC) of a battery pack ( 32 ) in a hybrid electric vehicle but always gives the driver the opportunity to make his/her own selection instead. The algorithm causes one of two strategies to be selected each time that the ignition switch is operated from “off” position to “on” position. The manner in which the algorithm executes depends on the value of a calibratable parameter electronically programmed into the controller of the particular vehicle when the vehicle is being built at the factory. | 1 |
SUMMARY OF THE INVENTION
[0001] The disclosed invention relates to apparatus for mounting on a mobile vehicle for pruning branches of vines and bushes in a ground growing crop including a pruning blade and means carried on the mobile vehicle for mounting the pruning blade for rotational movement in a predetermined position relative to the vines and bushes. The pruning blade includes a base plate that has a periphery and a center of rotation adapted to engage the means for mounting. Also included is a plurality of cutting members having peripheral cutting surfaces together with means for releasably fixing the plurality of cutting members around the periphery of the base plate in spaced position so that portions of the peripheral cutting surfaces extend beyond the base plate periphery.
[0002] In another aspect of the invention, a pruning blade is adapted to be mounted on a rotating drive shaft for use in mechanically pruning vines and bushes of a row-grown field crop, wherein the blade includes a flat base plate having a periphery and a centrally located opening for engagement by the rotating drive shaft. Also included is a plurality of cutting members having peripheral cutting surfaces, and means for releasable fastening the cutting members in spaced relation around the periphery of the base plate so that the peripheral cutting surfaces extend beyond the periphery of the base plate.
[0003] In a further aspect of the invention, apparatus is provided for pruning branches of vines and bushes of a ground growing crop wherein a vehicle for traversing the ground has a power source with a driver connected to the power source. A drive shaft is coupled to the driver at one end and has an opposing free end for positioning adjacent the crop. The improvement includes a base plate having a periphery and a centrally located attachment point for accepting and affixing the base plate to the drive shaft free end. A plurality of cutting members has peripheral cutting surfaces. Also included is means for releasably fastening the cutting members in spaced relation around the periphery of the base plate so that the peripheral cutting surfaces extend beyond the periphery of the base plate.
BRIEF DESCRIPTION OF THE DRAWINGS
[0004] [0004]FIG. 1 is a perspective of a preferred embodiment of the present invention.
[0005] [0005]FIG. 2 is an elevation of a mobile vehicle illustrating one manner of using the present invention.
[0006] [0006]FIG. 3 is a diagrammatic depiction of another manner of using the present invention.
DESCRIPTION OF THE PREFERRED EMBODIMENTS
[0007] Continuing efforts are made to reduce the costs of producing crops such as wine grapes. The cost of pruning an acre of wine grapes runs from $200-$250 when the pruning is done with hand labor. There are currently in existence several styles of mechanized pruning machines. Some machines use sickle-style cutters, much like the sickle cutters used to harvest hay. Other mechanized pruning machines have used large radial-style saw blades and yet other pruning machines have used a straight steel blade much like that seen on a lawnmower.
[0008] The foregoing mechanical pruning machines have several weak points. One of the things that growers of wine grapes want is a clean, smooth cut. It is undesirable to have a cut that shatters the end of the wood. As blades wear and become dull, the quality of the cut decreases. Large radial style saw blades in pruners have to be removed and resharpened. This requires a grower to have extra sets of large radial style saw blades which are very expensive. Without the extra sets the grower must idle his pruning crew while the saw blade is being sharpened. Further, as a vineyard is being pruned, the blades or cutters may come into contact with steel stakes as well as very hard, high tensile strength wire. The blades are immediately dulled when they contact such items.
[0009] The present invention uses the most common radial saw blade made. Seven and one quarter-inch Skil-Saw blades are preferred. They are inexpensive and readily available. Moreover, multiple 7-{fraction (1/4)} inch saw blades are much cheaper than one large diameter saw blade. Additionally, it proves to be very expensive to re-sharpen large diameter saw blades. Referring now to FIG. 1 of the drawings, the pruning blade assembly of the present invention is shown at 10 having a base plate 11 . A plurality of holes 12 , some of which are visible in FIG. 1, are arranged about the periphery of the base plate 11 . There is also an inner circle of holes 13 in the base plate as well as a center opening 14 .
[0010] A number of small diameter radial saw blades 16 are seen positioned in spaced relationship around the periphery of the base plate 11 . The small diameter saw blades are held in position by means of fasteners 17 that extend through centrally located holes (not shown) located on an axis of rotation of each of the small diameter saw blades and through one of the holes 12 in the base plate. The fasteners 17 are engaged at a free end by a threaded nut (not shown) if they extend to the opposite side of the base plate, or by threads formed in the holes 12 . Any other holding device will serve. While each individual small radial saw blade 16 is held in position on the periphery of the base plate 11 by a fastener 17 , each blade 16 is prevented from rotating about its axis by another fastener 18 that extends through one of the holes 13 in the base plate. The fastener 18 is engaged at the opposite side of the base plate by a holding device such as a nut or the like (not shown). FIG. 1 illustrates a washer-like member 19 that is placed under the head and around the shank of the fastener 18 . The edge of the washer 19 extends radially from the fastener 18 to overlap the periphery of an adjacent saw blade 16 and thereby fix the saw blade rotationally.
[0011] It may be seen from FIG. 1 that a greater or fewer number of saw blades 16 may be affixed on the periphery of the base plate 11 depending on the cutting requirement for the pruning job to be undertaken. Adding a greater number of smaller diameter saw blades to the periphery of the base plate 11 will provide a cutting edge that is more continuous for certain pruning purposes and placing a smaller number of saw blades 16 on the periphery of the base plate will provide fewer teeth for the pruning operation in accordance with different desired pruning results. Moreover, the tooth design on the saw blades 16 may be changed to provide either a coarse cut or a fine cut or a combination of several types of blade teeth may be provided, again depending on the pruning job requirements. In any event, when the exposed teeth extending from the periphery of the base plate 11 become dulled through use or as a result of contact with objects other than the vines or branches to be pruned, the fastener 17 may be loosened as necessary and then the fastener 18 may be loosened to relieve pressure on the washer 19 . The saw blade 16 may then be rotated through an arc to present new and sharp teeth along the portion of the saw blade that extends outwardly from the periphery of the base plate 11 . Since only a portion of the blade is in use at any one time, the saw blades may be rotated as described herein several times to provide a new group of sharp saw teeth for performing the pruning operation before the saw blade needs replacement. Common 7-{fraction (1/4)} inch Skil-saw blades cost less than $3.00 each. A 30-40 inch diameter pruning saw blade costs anywhere from $300 to $500. The saw blades 16 may simply be discarded once the teeth are dulled after several positions of the saw blade are assumed, while the more expensive large diameter pruning saw blades are so expensive that they are usually sent to be re-sharpened.
[0012] [0012]FIG. 2 is a rudimentary drawing of a crop harvester, similar to a harvester used to harvest vine-grown crops such as grapes. The harvester includes an inverted “U” shaped frame 20 that has wheels 21 for contacting the ground 22 , thereby allowing the harvester to traverse over the ground. A power source 23 is mounted on the harvester frame providing power which is transferred to a driver 24 , such as a hydraulic motor having an output shaft 26 extending therefrom. The output shaft 26 in the embodiment shown extends along an axis 27 (FIG. 1) that passes through the center of rotation of the pruning assembly 10 .
[0013] In the depiction of FIG. 2 a vine row, represented by the single vine trunk 28 and attached branches, is approached from both sides and the top by pruning assemblies 10 that are driven to rotate about their axes 27 when connected to the ends of the shafts 26 . The pruning assemblies 10 are positioned toward and away from the vines to be pruned by a known positioning assembly 29 , one for each pruning assembly. The positioning assemblies are represented in FIG. 2 as hydraulic cylinders that position each pruning assembly 10 closer to or farther from the row of vines to be pruned. FIG. 2 is representative of one configuration of pruning assemblies 10 , it being understood that one or two pruning assemblies may be all that is required for any particular pruning operation. The entire operation is controlled from an operator's station 31 located on top of the inverted “U” shaped frame 20 .
[0014] [0014]FIG. 3 shows an articulated arm that includes a first arm section 32 and a second arm section 33 . The second arm section 33 is depicted as part of the hydraulic positioning assembly 29 shown in FIG. 2. One end of the arm 32 is mounted at a pivot 34 attached to a frame 36 on a mobile vehicle used in harvesting operations. The free end of the arm 32 has a pivot 37 thereon to which is attached the second arm section 33 . Power is provided from a power source, similar to that described in FIG. 2, to a driver such as a hydraulic motor 38 (similar to motor 24 ) that is mounted near the free end of the articulated arm. An output shaft 39 extends from the motor 38 and provides rotational drive for the pruning assembly 10 . The pruning assembly is thereby rotated about the axis 27 at a predetermined speed depending upon the requirements of a particular pruning operation. It should be noted that the positioning devices shown as items 29 in FIG. 2 and as item 33 in FIG. 3 are controlled by positioning sensors (not shown), sometimes termed “row finders” in harvesting machinery parlance. These devices are included in this disclosure solely for the purpose of showing the environment in which the invention is useful as disclosed and claimed herein.
[0015] Although the best mode contemplated for carrying out the present invention has been shown and described herein, it will be understood that modification and variation may be made without departing from what is regarded to be the subject matter of the invention. | An inexpensive and readily available pruning blade for pruning crop growth, such as grape vines following harvest, has a disc-like base plate. The base plate has ordinary small diameter radial Skil-saw blades mounted around the periphery. The saw blades are fixed rotationally on the base plate by a clamp and have a portion of the saw teeth extending beyond the base plate periphery so that rotation of the base plate induces cutting action by the saw teeth at the periphery of the base plate. When the extending saw teeth become dull, the clamp is loosened, the saw blade is rotated through an arc sufficient to expose sharp teeth at the base plate periphery, and the clamp is tightened. | 8 |
BACKGROUND OF THE INVENTION
1. Field of the Invention
The present invention relates to an angle-adjusting device for a treadmill frame, and more particularly to an angle-adjusting device that makes the treadmill stable and vibrate less during operation.
2. Description of Related Art
With reference to FIG. 6, a conventional angle-adjusting device ( 50 ) for a treadmill frame in accordance with the prior art is adapted to be secured under the rear end of a treadmill. The treadmill ( 40 ) includes a front supporting lever ( 41 ), an erect handgrip frame ( 42 ), a belt frame ( 43 ), a traveling belt ( 45 ) and the angle adjusting device ( 50 ). The angle-adjusting device ( 50 ) is composed of a pair of polygonal feet ( 51 ) respectively mounted on opposite sides of the bottom of the rear portion of the belt frame ( 43 ). The polygonal feet ( 51 ) are triangular. The polygonal feet ( 51 ) are respectively rotatably mounted on opposite ends of a connecting rod ( 46 ).
Each polygonal foot ( 51 ) has multiple ground contact edges (not numbered), and each edge is a different length from the other edges so when any ground contact edge of the polygonal plate ( 51 ) contacts the ground, the sloping angle of the belt frame ( 43 ) is changed. Furthermore, changing the sloping angle of the belt frame ( 43 ) only requires raising the belt frame ( 43 ) to allow the ground contact edge of each polygonal plate ( 51 ) to be lifted clear of the ground. Thereafter, the two polygonal feet ( 51 ) are rotated on the connecting rod ( 46 ) to permit another ground contact edge to be parallel to the ground. Since the ground contact edge of the polygonal plate is changed, the sloping angle of the belt frame ( 43 ) can be easily changed to meet different requirements.
However, the conventional angle-adjusting device ( 50 ) is not directly secured on the belt frame ( 43 ), and a “linkage,” as show in FIG. 7, is formed between the angle-adjusting device ( 50 ) and the belt frame ( 43 ) in mechanics. The treadmill having a conventional angle-adjusting device ( 50 ) constitutes three links of a quaternary link, wherein the four links of the quaternary link are the angle adjusting device ( 50 ), the belt frame ( 43 ), the front supporting lever ( 41 ), and the ground. Stability of this linkage can be estimated by the Kutzbach formula:
F= 3( N− 1)−2 P
Wherein F is the degree of freedom of the kinematic chain;
N is the number of links; and
P is the number of pairs of elements.
Where N=4 and P=4 for the conventional quaternary link, F is 1. When F is positive, the kinetic chain being analyzed is under-constrained (i.e. moveable) according to the Kutzbach formula. Since F is positive for this quaternary link, the treadmill is unstable and will vibrate when someone steps or runs on the structure.
The present invention has arisen to mitigate and/or obviate the disadvantages of the conventional angle-adjusting device.
SUMMARY OF THE INVENTION
A main objective of the angle-adjusting device in accordance with the present invention is to make the treadmill stable during operation.
Further benefits and advantages of the present invention will become apparent after a careful reading of the detailed description with appropriate reference to the accompanying drawings.
BRIEF DESCRIPTION OF THE DRAWINGS
FIG. 1 is an exploded perspective view of an angle-adjusting device for a treadmill in accordance with the present invention;
FIG. 2 is an operational cross-sectional side plan view of the angle-adjusting device in FIG. 1;
FIG. 3 is another operational cross-sectional side plan view of the angle-adjusting device in FIG. 1;
FIG. 4 is a still another operational cross-sectional side plan view of the angle-adjusting device in FIG. 1;
FIG. 5 is a schematic diagram of a mechanic linkage wherein the angle-adjusting device in FIG. 1 is used as an element of the mechanic linkage;
FIG. 6 is a perspective view of a treadmill having a conventional angle-adjusting device; and
FIG. 7 is a schematic diagram of the mechanic linkage of the treadmill in FIG. 6, wherein the conventional angle-adjusting device is used as an element in the mechanical linkage.
DETAILED DESCRIPTION OF THE INVENTION
With reference to FIG. 1, an angle-adjusting device for a treadmill in accordance with the present invention comprises a pair of attachment blocks ( 11 ), a pair of pins ( 30 ) and a pair of polygonal feet ( 20 ). One polygonal foot ( 20 ) is attached to each attachment block ( 11 ) with one of the pins ( 30 ). In all other respects, the treadmill ( 40 ) as shown in FIG. 6 and further including a front supporting lever ( 41 ), an erect handgrip frame ( 42 ), a belt frame ( 43 ) and a traveling belt ( 45 ) is conventional. The belt frame ( 43 , 10 ) has a front end, a rear end, a top, a bottom and two sides. To avoid unnecessary repetition of known knowledge and techniques, no further description of the treadmill is provided. The polygonal feet ( 20 ) are respectively mounted on opposite sides of the bottom near the rear end of the belt frame ( 10 ).
The attachment block ( 11 ) is adapted to be secured near the rear end under the belt frame ( 10 ) of a treadmill and has a transverse through hole ( 12 ) defined in the attachment block ( 11 ). The polygonal foot ( 20 ) consists of two symmetrical polygonal plates ( 21 ) and a bridge ( 23 ) mounted between and connecting the two polygonal plates ( 21 ). Each polygonal plate ( 21 ) is made of resilient plastic and has multiple edges (not numbered), and each edge is a different length from the other edges. Further, a pin hole ( 22 ) is defined in each polygonal plate ( 21 ) to align with the transverse through hole ( 12 ) in the attachment block ( 11 ). The pin hole ( 22 ) is figure-eight shaped and has a first and a second round portion (not numbered) partially overlapping each other. A recess ( 24 ) corresponding to the shape of a distal end of the attachment block ( 11 ) is defined in the bridge ( 23 ) to receive the attachment block ( 11 ) inside the recess ( 24 ). The pin ( 30 ) penetrates the pin holes ( 22 ) in the polygonal plates and the transverse through hole ( 12 ) in the attachment block ( 11 ) to attach the polygonal foot ( 20 ) to the belt frame ( 10 ). The first round portion of the pin hole ( 22 ) is defined in an outer portion of the polygonal plate ( 21 ) and provides a releasing space for the pin ( 30 ) to remove the attachment block ( 11 ). Additionally, a connecting rod (not shown) pivotally extends between the two polygonal feet ( 20 ) to make them rotated synchronously.
With reference to FIG. 2, when the angle-adjusting device is used, the polygonal foot ( 20 ) is moved toward the attachment block ( 11 ) until the first round portion of the pin hole ( 22 ) is aligned with the transverse through hole ( 12 ) of the attachment block ( 11 ). Then, the pin ( 30 ) penetrates through the holes ( 22 , 12 ) to attach the polygonal foot ( 20 ) to the belt frame ( 10 ). The pin ( 30 ) engaging the attachment block ( 11 ) is wedged to transplace from the first round position to the second round position when the foot ( 20 ) is moved toward the attachment block ( 11 ), such that the pin ( 30 ) is held inside the second round position. At the same time, the distal end of the attachment block ( 11 ) is wedged and completely received inside the recess ( 24 ) to construct a rock-steady junction between the polygonal foot ( 20 ) and the belt frame ( 10 ).
With reference to FIGS. 3 and 4, when the polygonal foot ( 20 ) is pulled away from the attachment block ( 11 ), the pin ( 30 ) will be forced to move from the second round portion back to the first round portion of the pin hole ( 22 ). Then, the distal end of the attachment block ( 11 ) is withdraw from the recess ( 24 ), and the attachment block ( 11 ) is separated from the bridge ( 23 ). Consequently, the polygonal foot ( 20 ) is rotated to make a different parts of the edges contact the ground to change the height of the angle-adjusting device and the inclination of the belt frame ( 10 ). The attachment block ( 11 ) is held between the pair of polygonal plates ( 21 ) and presses against the side edges of the bridge ( 23 ). Hereafter, the pin ( 30 ) is moved to the second round portion of the pin hole ( 22 ) to tightly hold the attachment block ( 11 ) against the bridge ( 23 ).
Based on the foregoing description, it is easily understood that because the belt frame ( 10 ) is firmly combined with the polygonal foot ( 20 ), the “linkage” between the belt frame ( 10 ) and the polygonal foot ( 20 ) is not rotatable or movable. Thus, the kinematic chain of the treadmill when this invention is used is a ternary link that is a locked chain having no movement.
With reference to FIG. 5, when the Kutzbach formula is used again, N=3 and P=3 for the ternary link of the treadmill when the angle-adjusting device in accordance with the present invention is used, and F is 0. When F=0 in the Kutzbach formula, the system being analyzed is exactly constrained. Therefore, the system with the ternary link is more stable than the quaternary link of the conventional angle-adjusting device.
Although the invention has been explained relative to its preferred embodiment, it is to be understood that many other possible modifications and variations can be made without departing from the spirit and scope of the invention as hereinafter claimed. | An angle-adjusting device for a treadmill is composed of two attachment blocks ( 11 ) respectively secured at a certain position at two sides of the belt frame of the treadmill and two polygonal feet ( 20 ) corresponding to the attachment blocks ( 11 ). Each polygonal foot ( 20 ) is rotatably attached to the attachment block ( 11 ) and directly engages the attachment block ( 11 ). Therefore, the belt frame ( 10 ) is immovably combined with the polygonal feet ( 20 ) to ensure the treadmill has less vibration during operation. | 0 |
This is a continuation of application Ser. No. 07/922,126 filed on Jul. 29, 1992, now abandoned.
TECHNICAL FIELD
The invention relates to eggs and, particularly, to the discovery of an improved technique for processing eggs, especially low-cholesterol egg products based principally on egg whites, at high temperatures to provide liquid, pasteurized egg products which exhibit improved microbiological stability during refrigerated storage.
Pasteurization employs the controlled application of heat to reduce the population of microorganisms which affect the safety and preservation of food products, such as eggs. Eggs are particularly susceptible to degradation during heating due to the nature of their protein content. They can easily start to congeal and lose other aspects of functionality. The attainment of a product which is functional and can yet be stored in liquid form has been long sought, especially for low-cholesterol egg products which don't contain significant levels of natural yolk.
To achieve pasteurization sufficient to provide room-temperature-stable or refrigerator-stable eggs on a commercial scale, it is necessary to significantly reduce the counts of Salmonella, Listeria and spoilage-promoting organisms. Unfortunately, it is difficult to control processing to achieve sufficient bacterial destruction without coagulating the egg protein. Current technology has focused on procedures which maintain the greatest possible amount of desired protein functionality. This, however, adds expense and stresses control systems. When the balance is struck too near those conditions which maximize functionality while providing marginal stability, the probability is increased that one or more containers of product will fail to provide long-term stability.
There is a present need for a process which would enable an increased thermal destruction of microorganisms while maintaining the simplest and safest control procedures.
BACKGROUND ART
Egg white is a perishable product, even when stored under refrigeration, due to the growth of spoilage organisms. Most commercial pasteurization processes are intended to decrease the risks posed by pathogenic organisms such as Salmonella bacteria.
The temperatures necessary to achieve eradication of spoilage organisms are not easily, reliably reached without causing protein denaturation. Severe denaturation results in coagulation of the entire product, and this is considered undesirable because consumers prefer liquid, pourable products for convenience in a wide variety of recipes. Accordingly, the most typical commercial products are marketed in the frozen state and permit only one to two weeks stability at refrigerator temperature (4° C). Until recently, refrigerator or room-temperature stable liquid egg products were not available. The present invention has special applicability to products based principally on egg white and provides an improvement over current, state-of-the-art technology.
Egg white, also referred to in the art as egg albumen, is actually a complex mixture of several different types of soluble protein. Significant among these are conalbumin, which is the second most abundant, and ovalbumin, the most abundant. All of the proteins will coagulate and lose their water solubility after heating for well-defined time-temperature combinations. However, not all proteins respond the same, and their responses can be altered by the presence of certain natural and added materials. For example, it is disclosed in European Patent Application 344,123 by Maley et al that whole eggs can withstand temperatures about 20° F. higher than egg white. The onset of coagulation of egg white becomes a problem around 140° F., due principally to the denaturation of the conalbumin.
In one early advance in egg pasteurization, Lineweaver and Cunningham disclosed in U.S. Pat. No. 3,251,697, that the addition of certain polyvalent metal salts enabled increasing the pasteurization temperature several degrees while not adversely affecting the physical properties of the egg. Similarly, in Food Products Formulary, Vol. 2, p.375, by Tressler and Sultan, it is indicated that salts of aluminum and iron can suppress coagulation by forming heat-stable complexes with conalbumin. However, this technique alone does not enable high enough heat treatments to achieve the stability necessary for reasonable periods of refrigerator storage.
With the addition of metal salts to formulations based essentially on egg white in U.S. Pat. Nos. 3,840,683 and 3,911,144, Strong and Redfern pasteurized at about 136° F. for five minutes. These patents disclosed substantially cholesterol and egg yolk-free frozen egg products which had good freeze-thaw stability. This technology permitted the marketing and wide availability of a health-oriented product highly desired by many egg lovers. When frozen, the products last for extended times. It would be desirable, however, to improve the stability of such products against spoilage when maintained in a refrigerated condition.
Other early disclosures, primarily for frozen and dry egg products, employ hydrogen peroxide to aid in pasteurization. In both U.S. Pat. No. 2,776,214 to Lloyd et al and U.S. Pat. No. 3,364,037 to Mink et al hydrogen peroxide is added to egg prior to heating. The first of these discloses destroying natural catalase by heating egg white prior to adding the peroxide. The second adds an alkali. A later patent to Kohl et al (U.S. Pat. No. 3,615,705) combines these two teachings.
More recently, efforts have been made to produce products which remain stable for extended periods of refrigerated or room-temperature storage. For example, in U.S. Pat. No. 3,928,632, Glaser and Ingerson disclosed an aseptically-packaged, low-cholesterol egg product having an additive emulsion which is separately sterilized and homogenized prior to mixing with an egg component. No details of egg pasteurization are provided, but a lactylate salt is an essential ingredient.
In U.S. Pat. No. 4,971,827, Huang discloses that temperatures high enough to obtain a refrigerator-temperature-stable liquid egg product, can be employed when turbulent flow is achieved during pasteurization. To prepare the liquid egg product for heating, it is first heated to about 120° F. and then homogenized. This is followed by a 2-stage heat process employing turbulent flow and resulting in a product temperature of 162° F. The product is cooled and directly packaged without further homogenization. The example states that minimum denaturation was indicated by the percentage of water-soluble protein in the product.
In U.S. Pat. No. 4,853,238, Huang discloses a process which does not require turbulent flow even though even higher temperatures are employed. According to this latter process, microwave energy is used to heat a liquid egg composition in small diameter polytetraflouroethylene tubes at 185° F. for 0.02 seconds to achieve pasteurization without undue coagulation or fouling of heat exchange surfaces. The heated liquid egg composition is rapidly chilled directly following heating. Again, a minimum functional loss in the finished product is reported and no homogenization following the pasteurization is disclosed. Because there is such a small hold time at the temperature identified as necessary and because microwave heating is often difficult to apply uniformly, rigorous quality control checks will be required to assure proper processing.
Swartzel et al, in U.S. Pat. Nos. 4,808,425, 4,957,759, and 4,994,291, disclose the preparation of shelf-stable whole egg products by high-temperature, short-time ultrapasteurization of liquid whole egg. Consistent with published procedures, they suggest heating under turbulent flow conditions. To improve pasteurization, they disclose the desirability of reducing the protein and fat unit size prior to heating. This is said to reduce any tendency of the product to coagulate. Denaturation is preferably kept as low as possible, but it is suggested that a homogenization step after heating be included for this whole egg product.
DISCLOSURE OF THE INVENTION
It is an object of the invention to provide a process for pasteurizing liquid egg products under conditions which maximize the reduction of viable organisms.
It is another object of the invention to provide a refrigerator-stable packaged egg product having a smooth pourable texture.
It is another object of the invention to improve the processing of liquid egg products which are essentially free of fat and cholesterol.
It is yet another object of the invention to improve current egg processing to provide an improved packaged egg product.
These and other objects are accomplished according to the invention which provides an improved process for pasteurizing liquid egg formulations and improved packaged, pasteurized liquid egg formulations.
According to the process aspect of the invention, an improvement is provided in the preparation of a packaged, pasteurized liquid egg product by heating a liquid egg composition to a pasteurization temperature and holding the composition at that temperature for a time period effective to reduce the population of viable microorganisms, cooling the pasteurized egg composition, and packaging the egg composition in a sealed container, the improvement comprising: heating the liquid egg composition at a temperature and time sufficient to provide pasteurization while resulting in some coagulation of conalbumin, but not significant coagulation of ovalbumin. The liquid egg containing coagulated conalbumin is then homogenized to particulate and disperse the coagulated egg composition. Conalbumin coagulation is typically greater than 5% and can be up to 100%.
Hydrogen peroxide and/or a coagulation-suppressing composition can be added to the liquid egg prior to heating. The coagulation-suppressing composition can be selected from the group consisting of polyvalent metal compounds, organosulfur compounds, and mixtures of these.
The product aspect of the invention provides a packaged liquid egg composition prepared according to the above process. Viewed from another perspective, the invention provides a packaged liquid egg composition comprising a dispersion of finely-divided particles of coagulated conalbumin in a liquid egg matrix. The preferred products remain stable at refrigerator temperature for at least 30 days.
BRIEF DESCRIPTION OF THE DRAWINGS
The invention will be better understood and its advantages will become more apparent when the following detailed description is read in conjunction with the accompanying drawing wherein:
The Figure is a flow diagram of a preferred embodiment of the process.
DETAILED DESCRIPTION OF THE INVENTION
The invention will be described in terms of the pasteurization of a liquid, low-cholesterol egg formulation comprised principally of egg white and preferably contains little or no egg yolk. Representative compositions of this type are exemplified in U.S. Pat. Nos. 3,840,683 and 3,911,144 to Strong and Redfern, U.S. Pat. No. 3,928,632 to Glaser and Ingerson, U.S. Pat. No. 4,971,027 to Huang, and European Patent Application 344,123 to Maley et al. The invention is not limited to compositions of this type and can be used with whole egg product formulations as disclosed by Swartzel et al in the U.S. Patents identified above. Each of the above patent disclosures is incorporated by reference in its entirety.
Pasteurization entails heating the liquid egg to a temperature and for a time effective to eliminate pathogenic organisms such as Salmonella and to extend the refrigerated storage life of the product by significantly reducing the number of spoilage microorganisms. The heat treatment necessary to kill the microorganisms is, like that which causes coagulation of protein, a function of both time and temperature. Lower temperatures require longer pasteurization times and higher temperatures permit shorter times. The heat treatment desirably causes at least a "nine log cycle" (9D) reduction in the count of viable Salmonella organisms, i.e., the number is reduced 99.9999999%. Typically, the count of spoilage causing microorganisms is reduced sufficiently to provide at least two weeks storage at refrigerator temperature, i.e. 4° C. Preferred degrees of heat treatment will enable refrigerator storage without spoilage for 30 days to 12 months, most preferably greater than 3 months.
Referring now to the Figure, liquid egg composition is shown held in suitable vessel 10 under agitation by suitable mixing means 12 at a temperature preferably between 1.5° and 5.5° C.
Typically, the low-cholesterol liquid egg compositions of the invention will have liquid egg white as the major component. Preferred low-cholesterol egg compositions comprise at least 95%, e.g., from 97 to 99.5%, egg white. Minor amounts of a variety of other ingredients, include water, vegetable oil, vegetable gums, vitamins, minerals, emulsifiers, stabilizers, and coloring. Metal salts and/or organosulfur compounds can be added to suppress coagulation during heating. Solid particulate foods such as meat, potato, pepper, onion and the like can be packaged with the liquid egg composition.
Preferably, the coagulation-suppressing polyvalent metal compound is a salt of a metal selected from the group consisting of aluminum, iron, copper, nickel, manganese, cobalt, zinc, and cadmium. Most desirably, the metal comprises aluminum. The disclosure of U.S. Pat. No. 3,251,697 to Lineweaver and Cunningham is incorporated herein by reference.
The organosulfur compound is desirably added to the egg in an amount effective to suppress coagulation, thereby permitting pasteurization at higher temperatures and/or for longer times. Typically, the organosulfur compounds will be used at levels of from 0.005 to 0.5 percent of the weight of the egg. Preferred amounts will be in the range of from 0.01 to 0.1 percent. This is disclosed by Rapp in U.S. patent application Ser. No. 07/686,911, filed Apr. 15, 1991, now U.S. Pat. No. 5,096,728.
Small amounts of vegetable oil can be added to help solubilize water-insoluble ingredients. In addition, small amounts of vegetable oil seem to impart certain subtle organoleptic characteristics of real egg (e.g. mouthfeel and texture), but the content typically remains low since it increases the caloric content of the product. Colorants are added to impart a color characteristic of whole egg. Preferred colorants include beta-carotene and/or approved FD & C food colorants (e.g. FD & C yellow #5 and #6).
Gums can be added to provide stablization, viscosity and suitable texture. In addition, they can reduce separation and syneresis. Preferably, gums such as guar gum, xanthan gum, locust bean gum, carrageenan and CMC are used. These can be added individually and in combination at levels of 0.05 to 0.5% by weight.
Prior to pasteurization, the egg composition is desirably tested and adjusted as necessary to achieve a pH typically in the range of 7.5 to 8.5. This can be accomplished with lactic acid or other suitable food acids. If necessary, a suitable alkaline material such as potassium carbonate may be used to adjust pH. Preferably, the egg white will have previously been pasteurized by a process that includes the use of hydrogen peroxide (i.e. Standard Brands and Armour processes, USDA, Egg Pasteurization Manual, ARS 74-78, pp. 19 et seq. and Egg Product Inspectors Handbook, AMS PY-Instruction No. 910, pp. 34 et seq.), which destroys natural catalase present in egg white.
From the vessel 10, the liquid egg is pumped through a suitable heat exchanger 14 such as a scraped surface, high velocity tube-in-shell or noncontacting heating mechanism such as microwaves, electrical resistance or radio frequency to bring the temperature rapidly up within the range of 60° to 75° C., e.g. preferably at least 70° C. At this point or elsewhere before final cooling, the liquid egg composition can be treated with hydrogen peroxide as set forth in commonly assigned, copending U.S. patent application Ser. No. 07/807,306 filed Dec. 13, 1991 in the names of A. Cascione and H. Rapp, now U.S. Pat. No. 5,266,338. For example, the heated egg can be homogenized such as by means 16 (e.g. suitable dairy homogenizer) and the hydrogen peroxide can be injected, such as via line 18, at a location which assures contact temperatures (e.g., at least 58° C.) and times effective to reduce the population of viable organisms as necessary to meet the requirements of the storage conditions.
The heated liquid egg composition can be held, such as in holding tube 22, for a short time effective at that temperature, to achieve the desired reduction in microoganisms. This is followed immediately by cooling, such as in heat exchanger 24, to below coagulation temperature, e.g. below 54° C. The liquid egg composition is then preferably subjected to homogenization by means 20. This can be done in a suitable dairy homogenizer by operating at 500 to 5000 psig.
If desired, catalase or ozone can be added such as by injection downstream via line 26, to eliminate residual peroxide. A holding tube 28 can be provided following catalase injection to allow sufficient time for catalase to break down peroxide. If catalase injection is necessary, the temperature should be effective for its purpose. The composition could then be deaerated by suitable means 30. Final cooling can be provided by a suitable heat exchanger 32 to a temperature preferably less than 4.5° C.
The resulting product has a smooth, homogenous texture. The homogenization by means 20 is preferably sufficient to reduce the size of the coagulated conalbumin particles to less than 2 microns in diameter and produce a dispersion of coagulated conalbumin particles in a liquid matrix. Desirably, at least 96% by weight of the particles should be within the range of from 0.5 to 2.0 microns. This particle size and distribution has the advantage of improving the texture of the product for eating and stability during storage. The dispersed particles also impart a degree of opacity which eliminates the need for including additives for this purpose. The composition has a smooth-pouring viscosity at this point, typically in the range of from about 10 to about 500 centipoises when measured by Brookfield Viscometer (Model RV) at 10 rpm using spindle 1 and a product temperature of 4.5° C. The amount of coagulated conalbumin can act as an indicator of the degree of heat treatment received by the product. The degree of conalbumin denaturation can be determined by DSC (differential scanning calorimetry).
The processed liquid egg is then packaged by feeding it into a heat-sealable package, typically a polymer-coated, fiberboard, gusseted-top container. Other acceptable containers would include cups made of plastics such as polypropylene, other suitable materials or laminates, as well as rectangular packages composed of paper/aluminum foil/polymer laminates. Following filling, the container is sealed. Desirably, filling and sealing will be under aseptic conditions. The filled and sealed containers are then refrigerated. Products prepared and packaged in this manner will preferably be stable against spoilage at refrigerator temperature (4° C.) for at least 2 weeks, preferably at least 30 days, typically from 60 to 180 days. If desired, they can be frozen.
The following example is presented to further illustrate and explain the invention and is not to be taken as limiting in any regard. Unless otherwise indicated, all parts and percentages are based on the weight of the composition at the indicated point in the process.
EXAMPLE
A refrigerator-stable liquid egg product is prepared employing the following formulation and using processing equipment as schematically shown in the Figure.
______________________________________INGREDIENT PARTS______________________________________Egg White 99.066Gums 0.200Color 0.070Vitamins and Minerals 0.029Vegetable oil 0.300Metal Salt Sol'n 0.065Acid 0.070Water 0.200______________________________________
The egg composition is fed from vessel 10 to heat exchanger 14 which raises the temperature of the composition to about 72° C. and held in pasteurization holding tube 22 at that temperature for 0.25 to 6 minutes. Prior to entry into the hold tube, the composition is homogenized at 16 in a suitable dairy homogenizer operated at 500 to 5000 psi, and hydrogen peroxide is added at a level of 30-1500 ppm at line 18 and mixed into the liquid egg by means of an in-line mixer not shown. Following the holding tube 22, the liquid egg composition is cooled to 49° C. in heat exchanger 24.
This is followed by homogenization at 20 in a suitable dairy homogenizer operated at 500-5000 psi to obtain a finished product with the desired smooth, homogeneous and opaque appearance. The product is then cooled in heat exchanger 32° to 4.5° C. or less. The liquid egg composition at this point exhibits a viscosity of 10-500 centipoise as measured by a Brookfield Viscometer (Model RV) at 10 rpm using spindle No. 1 with product at 4.5° C. The process causes selective denaturation, in this case about 70 to 90%, of the conalbumin, but not ovalbumin. In addition, the appearance is opaque due to the suspension and dispersal of the coagulated particles, and this has the advantage of reducing the need for opacifiers (cloud). The composition is then packaged in sealed containers under aseptic conditions. The product is stable at refrigerator temperature (4° C.) for 3 months.
The above description is for the purpose of teaching the skilled worker how to practice the invention and is not intended to detail all of the obvious modifications and variations of it which, while not specifically set forth, are included within the scope of the invention which is defined by the following claims. | The invention enables processing eggs, especially low-cholesterol egg products based principally on egg whites, at high temperatures to provide liquid, pasteurized egg products which exhibit improved stability during refrigerated storage. Liquid egg composition is heated to a temperature (e.g. 60° to 75° C.) and for a time effective to reduce the population of viable organisms with some coagulation of the conalbumin, but without significantly coagulating the ovalbumin. A dispersion of coagulated conalbumin in a liquid matrix is homogenized (average particle size is preferably less than 2 microns) to form a smooth-textured, liquid egg composition. The resulting liquid egg compositions have unique textural and visual characteristics. | 0 |
BACKGROUND OF THE INVENTION
[0001] This application claims priority to United States Provisional Patent Application No. 60/688,586, filed Jun. 8, 2005.
FILED OF THE INVENTION
[0002] The invention relates generally to alloys of cast iron and, more specifically, to alloys of cast iron to which boron has been added and which increase the annealability of carbidic ductile iron in articles cast using the alloy and/or promote the formation of ferrite.
BACKGROUND OF THE ART
[0003] Cast iron is an alloy of iron and carbon in which the carbon is in excess of the amount that can be retained in solid solution in austenite at the eutectic temperature. Carbon is usually present in the range of 1.8% to 4.5%, in addition, silicon, manganese, sulfur, phosphorus and other residual or specifically added alloying elements, all in varying amounts. Specific types of cast iron include gray, malleable, ductile and white irons. Magnesium is typically added to a low sulfur iron to produce ductile (spheroidal graphitic) iron. Because of the high carbon content, the structure of cast iron, as opposed to that of steel, exhibits a rich carbon phase. Depending primarily on composition, cooling rate and melt treatment, cast iron can solidify according to the thermodynamically metastable Fe-Fe 3 C system or the stable Fe-Gr system.
[0004] In the Fe-Fe 3 C system, the rich carbon phase in the eutectic is iron carbide. In the Fe-Gr system, the rich carbon phase is graphite. An example of the Fe-Fe 3 C system is what is known as “white iron.” White iron exhibits a white, crystalline fracture surface because fracture occurs along the iron carbide plates; it is the result of metastable solidification (Fe 3 C eutectic). An example of the Fe-Gr system is what is commonly known as ductile iron, but has also been called spheriodal, nodular or SG iron. The graphite in this iron is present as nodules as compared to the graphite flakes in gray iron.
[0005] However, the properties of ductile iron are controlled not only by the spheriodal shape of the graphite, but also by the metallurgical structure of the matrix. This matrix microstructure is controlled by the alloy content, whether deliberately added or as generally called “residuals,” and the cooling rate. Thus it is possible to have the graphite present with a spheriodal graphite morphology and also have a matrix that contains both primary carbides, ferrite and pearlite. Until the matrix structure is entirely ferritic, the impact strength and ductility of the casting will not be maximized. This maximization is often achieved by an annealing process in conjunction with minimizing the deleterious elements.
[0006] Previous research efforts include Ball, D L, Nucleation of Euctectic Graphite in Cast iron by Boron Nitride, AFS Transactions, 1967 P 428-432; Ball, D L, Transactions of the Metallurgical Society of AIME, V 239 January 1967 P 31-36; Pehlke, R D, Wasa, H, Strong, G R Nitrogen in Malleable Iron Production, AFS Transactions 1978 P 125-134; Dawson, J V, Smith, W L, Bach, B B, Some Effects of Nitrogen in Cast Iron, Journal of Research and Development of the BCIRA, Research Report 355, 1953 and Sandoz, G, White Cast Iron Inoculation Effect on Graphitization AFS Transactions 1962 P 13-17 have shown that nitrogen can be present as dissolved (monatomic nitrogen) in cast iron that this nitrogen will affect both graphite morphology and matrix microstructure. Work also showed the boron will react with the dissolved nitrogen during solidification to form boron nitride (BN). Work by Ball in cast iron showed that the boron nitride formed a BN nucleus upon which graphite would form during solidification. This nucleus has a crystallographic structure similar to graphite.
[0007] Other research work showed that boron additions during the processing of molten steel ties up nitrogen, again forming BN, and prevents problems associated with monatomic nitrogen.
[0008] There is a need, accordingly, for a ductile iron that will readily respond to an annealing treatment and/or will exhibit a higher percentage of as-cast ferrite and a minimization of primary and intercellular carbide. It is known that nitrogen is an element that is present in molten iron and that nitrogen is a carbide stabilizer. Thus there is a need for an element or alloys of elements that can be added to molten ductile iron that will not only reduce the impact of dissolved nitrogen but will also promote the formation of ferrite, thus negating some of the influence of other carbide/pearlite stabilizing elements and/or to promote the annealability of the iron, which may be a necessary process to remove carbides from a rapidly cooled casting such as might be encountered when producing ductile iron pipe by the centrifugal casting process.
[0009] SUMMARY OF THE INVENTION
[0010] The invention consists of alloys used to promote the formation of ferrite and enhance the annealability of ductile iron. The alloys are characterized in that a source of boron is added to provide boron between about 10 and 150 ppm and preferably between about 35 and 85 ppm. The addition of boron is observed to increase the nodule count and enhance the annealability of the ductile iron such that the solutioning time (time to eliminate primary carbides) and the cooling rate (time to avoid the presence of pearlite in the final room-temperature structure) can be significantly reduced as compared to non-boron treated ductile iron.
BRIEF DESCRIPTION OF THE DRAWINGS
[0011] FIG. 1 is a 100X photomicrograph of a chill cast section (½ inch thick) of non-boron treated ductile iron
[0012] FIG. 2 is a 100X photomicrograph of a chill cast section (½ inch thick) of a boron treated (57 ppm) ductile iron.
[0013] FIG. 3 is a 100X photomicrograph of a chill cast section (½ inch thick) of a non-boron treated iron after heat treatment at 1600° F. for three-quarters of an hour—open door furnace cool.
[0014] FIG. 4 is a 100X photomicrograph of a chill cast section (½ inch thick) of a boron treated (80 ppm) ductile iron after heat treatment at 1600° F. for three-quarters of an hour—open door furnace cool.
DETAILED DESCRIPTION OF PREFERRED EMBODIMENTS
[0015] Ductile iron as used in this disclosure is defined as an iron composition having the components and ranges as set out in Table 1.
[0016] Non-chill cast iron as used in this disclosure is defined as iron cast in a sand mold, such mold not containing any type of insert that accelerates the rate of heat removal compared to sand.
TABLE 1 Composition of Ductile Iron Weight Percent Element 2.0-4.0 Carbon 1.5-4.0 Silicon .1-1.5 Manganese .005-.05 Sulfur .01-.05 Magnesium Balance Iron and other incidental residual elements
[0017] It is recognized that the spheriodal graphite shape in ductile iron is a result of treatment of the molten iron with magnesium. There are other treatments, such as with rare earths, that will also produce the desired spheroidal structure. The method of treatment to achieve the spheriodal graphite structure is not critical to this invention.
[0018] The solubility of nitrogen (monotomic nitrogen) in molten iron is influenced significantly by both temperature and the composition of the molten iron. Carbon and silicon both reduce the equilibrium value of nitrogen in what would commonly be called molten cast iron. Uda and Pehlke (Uda & Pehlke, Part 1 -Solubility of Nitrogen in Cast Irons, AFS Transactions, 1971, Paper No. 82) showed that the solubility of nitrogen in a molten alloy at 1500C (2732° F.) in an iron alloy with 3.5% C −2% Si is approximately 120 ppm. The paper thoroughly describes the mathematical relationships between the variables of carbon and silicon content and temperature. Numerous nitrogen analyses on gray and ductile irons show that the typical nitrogen content is between approximately 60 ppm and 110 ppm. It is also known that desulfurization processes and magnesium treatment processes will lower the dissolved nitrogen; but essentially never below 50 ppm.
[0019] Boron has an atomic radii of 0.97A and nitrogen has an atomic radii of 0.71A and atomic weights of 10.82 and 14.08 respectively. As written in a paper by Gloria M. Faulring (Faulring, Nitrogen Scavenging with Boron, Electric Furnace Conference Proceedings, 1989, Pages 155-161): “The amount of boron required for scavenging nitrogen depends on the nitrogen content of the steel (iron). To optimize the effectiveness of the boron, the contained amount should be 0.8 to 1.0 times the nitrogen content, preferably about 0.8 i.e. % B/% N=0.8 to 1.0. The stoichiometric ratio of the amounts of boron and nitrogen in BN is 0.77.”
[0020] However, boron is a strong carbide former and any amount in excess of the stoichiometric amount needed to tie up nitrogen as BN promotes the formation of very stable carbides, which can be difficult to remove during normal heat treatments. These carbides are typically present as intercellular carbides and are detrimental to impact strength of an annealed ductile iron.
[0021] Trials have been run with boron levels above 150 ppm and intercellular carbides were observed as a result of this boron level. In cases, where trials were run with and without boron, with chemistries designed to promote carbides, boron additions in the 150 ppm plus range always generated more intercellular carbides than the same alloys without the boron addition.
[0022] Thus one can conclude that boron levels must be kept below that which will cause the formation of boron containing carbides because these carbides will not be removed under the same annealing conditions as those alloys that do not exhibit boron-induced carbides. At those boron levels, even though a higher nodule count may be observed, the ductile iron will resist annealing. The intercellular carbides remaining after the annealing process will reduce the impact strength and ductility of the annealed ductile iron.
[0023] Thus to successfully utilize this boron practice, the boron level must be kept below that which will create stable boron-alloy carbides. One would then conclude that the optimum desired practice of the art would include a nitrogen analysis and the boron level should not exceed this nitrogen level. In the absence of nitrogen analysis, and based on numerous published and published studies of nitrogen levels of ductile iron after magnesium treatment, the boron level in the alloy should not exceed about 60 ppm.
EXAMPLE I
[0024] Boron was added to a ladle of molten iron in the form of FeB. The alloy used to make the boron addition is understood not to be critical to the observed results. The chemistry of the molten iron used in this Example I is provided in Table 2.
TABLE 2 Composition of Alloy Element Percentage (%) Carbon 3.67 Silicon 2.88 Manganese .33 Sulfur .008 Magnesium .049 Copper .15 Chromium .03 Nickel .04 Molybdenum .01 Vanadium N.D. Tin .01 Aluminum .032 Titanium .006 Boron .0057 Nitrogen .0035 Iron and other Balance incidental residual elements
[0025] Samples of non-boron treated and boron treated iron as represented by the chemistry in Table 2 were heat treated to remove primary carbides and minimize the amount of ferrite. Table 3 summarizes the results of a heat-treatment cycle of 1600° F. for three-quarters of an hour followed by open-furnace door cooling
TABLE 3 Summary of Microstructural Results After Heat Treatment Sample Identification Microstructural Analysis Non boron Treated Chill Cast 3-5% carbide - 10-15% pearlite Ductile Iron Boron Treated Chill Cast Ductile Iron <1% carbide - 3-5% pearlite
[0026] Photomicrographs of these results are shown in FIGS. 1-4 . FIG. 1 (400X) shows the as-cast microstructure of the non-boron treated chill cast ductile iron. FIG. 2 shows (400X) shows the as-cast microstructure of the boron treated chill cast ductile iron. FIGS. 3 and 4 respectively show the two structures after a solutioning heat treat of 1600° F. for three-quarters of an hour followed by an “open-door” furnace cool. It is apparent that the boron greatly enhanced the annealability of the ductile iron and that the graphite nodule count of the boron treated ductile iron was greater than the non-treated iron.
EXAMPLE II
[0027] Experimental samples of ductile iron, having the nominal composition and ranges set out in Table 4, were treated with boron.
TABLE 4 Composition of Alloy Element Percentage (%) Carbon 3.3-3.4 Silicon 2.0-2.15 Manganese 0.33-0.40 Sulfur 0.001-0.002 Magnesium 0.024-0.040 Copper 0.30-0.37 Chromium 0.17-0.20 Tin 0.009-0.012 Iron and other Balance incidental residual elements
[0028] The alloy used to make the boron addition is understood not to be critical to the observed results. The molten alloy was produced in a commercial pipe (deLavaud process) foundry. The metal had been cupola melted and dosed with 5% magnesium ferrosilicon to provide nominally 0.03% magnesium to provide sufficient magnesium to produce the residual magnesium concentration set out in Table 4 at the treatment temperature of the foundry. Samples of molten alloy were removed from the deLavaud machine with a ladle. The samples were treated with two different sources of boron, FeB and TiB 2 , in nominal amounts to provide 80 ppm of boron. The sources of boron were added to a pouring ladle, molten alloy was added to the pouring ladle and, after brief stirring with a steel rod, the samples were poured into chill molds to simulate the solidification rate of metal in the deLavaud molds. To dissolve any carbides and produce a ferritic matrix, the samples were then heat treated at between about 1700° F. and 1850° F. for 20-25 minutes, temperatures typical of the pouring temperatures for deLavaud pipe. Samples of untreated iron were also cast and subjected to heat treatment under the same conditions. Three castings of the untreated iron were prepared and two castings each of the FeB-treated the TiB 2 -treated iron were prepared. After heat treatment, the samples were allowed to cool and then cut into sections. The microstructures of twenty-five sections of each sample were examined and the nodules per square millimeter counted to determine if the boron-treated irons had increased nodule count, indicating that the boron treatments could be used to reduce the heat treatment time and energy required. The results are summarized in Table 5.
TABLE 5 Nodule Counts of Treated and Untreated Iron Addition of Addition of Control FeB (80 ppm) TiB 2 (60 ppm) Alloy Addition Type None FeB TiB 2 Alloy Addition Amount 0 1 g 0.33 g Ave. Nodule Count 426 565 516 Std. Dev. 165 140 110
[0029] The results show that the addition of nominally 80 ppm boron in the form of FeB or approximately 60ppm in the form of Titanium Diboride increased the nodule counts by between about 20 to 35%. No attempt was made to optimize the amount of boron added to the alloy. Those skilled in the art will recognize that higher nodule counts can be expected to substantially decrease the time required both for carbide dissolution and heat treatment time and energy.
[0030] The foregoing description and drawings comprise illustrative embodiments of the present inventions. The foregoing embodiments and methods described herein may vary based on the ability, experience, and preference of those skilled in the art. Merely listing the steps of the method in a certain order does not constitute any limitations on the order of the steps of the method. The foregoing description and drawings merely explain and illustrate the invention, and the invention is not limited thereto, except insofar as the claims are so limited. Those skilled in the art who have the disclosure before them will be able to make modifications and variation therein without departing from the scope of the invention. | The alloy of ductile cast iron to which boron has been added is found to have improved annealability as compared to a non-boron treat ductile iron. The addition of boron in amounts between about 10 ppm and 150 ppm by weight effectively combines with nitrogen dissolved in the molten iron and thus serves to minimize the influence of nitrogen on the stability of carbides and pearlite and also forms BN, which can serve as nuclei for the precipitation of graphite. | 2 |
[0001] This invention relates to improvements in Surface Acoustic Wave [SAW] devices and particularly layered SAW devices used as sensors.
BACKGROUND OF THE INVENTION
[0002] SAW devices are usually used in a closed loop with an amplifier to make an oscillator. There are patents which describes setting up a stable oscillator using a SAW device to generate clock pulses for electronic circuits. U.S. Pat. No. 3,979,697 discloses an oscillator in which the “tank circuit” or feedback element is a surface acoustic wave (SAW) bandpass filter (delay line). U.S. Pat. No. 4,868,524 discloses an RF circuit to generate a stable carrier signal using a Voltage Controlled Saw Oscillator. U.S. Pat. No. 5,126,694 discloses A SAW stabilized oscillator includes a phase locking circuit which is phase locked to a lower frequency reference signal having an odd order difference with respect to the fundamental frequency of the SAW oscillator.
[0003] SAW devices have been used as sensors in liquid and gaseous environments. U.S. Pat. No. 4,562,371 discloses a SAW device comprising a ZnO piezo layer on a cut crystalline silicon substrate that propagates Rayleigh waves.
[0004] The surface acoustic waves polarizes in 3 directions and can be classified as longitudinal wave motion, Normal waves or shear horizontal waves. A class of shear horizontal [SH] waves are called Love waves which are propagated in layered devices that concentrate the wave energy in a highly confined region near to the surface.
[0005] Rayleigh wave sensors have been useful in gaseous environments but they are not suitable for liquid environments because the surface-normal displacement causes strong radiative loss into the liquid. For sensing in liquids shear horizontal [SH] polarised wave modes are preferred since the particle displacement is parallel to the device surface and normal to the direction of propagation. This allows a wave to propagate in contact with a liquid without coupling excessive acoustic energy into the liquid. However the SH wave is distributed through the substrate and therefore does not have the same sensitivity as the SAW. For increased sensitivity Love waves which are SH-polarised guided surface waves may be used. The waves propagate in a layered structure consisting of a piezoelectric substrate and a guiding layer which couples the elastic waves generated in the substrate to the near surface. They are extremely sensitive to surface perturbations due to the energy confinement to the near surface. By observing the magnitude of perturbations it is possible to measure the strength of the interaction. The interactions may be caused by mass density, elastic stiffness, liquid viscosity, electric and dielectric properties. The more sensitive is the device the smaller the quantities that can be measured.
[0006] U.S. Pat. Nos. 5,130,257, 5,216,312, 5,283,037 and 5,321,331 disclose love mode SAW sensors used in liquid environments. The love waves are produced by cutting the piezo electric material such as lithium niobate, lithium tantalate or quartz to couple energy from the interdigital transducers [IDT's] of the SAW device into shear transverse or love waves that enable the wave energy to be trapped at the substrate surface.
[0007] U.S. Pat. No. 5,705,399 discloses a SAW sensor for liquid environments having an AT cut quartz piezo substrate with electrodes connected to a first side in contact with a liquid and a second side that is not in contact. The sensor may be used to detect biological species such as antigens.
[0008] WO02/095940 discloses a love mode SAW sensor using a piezo layer of ZnO on a piezo electric quartz crystal.
[0009] To improve the sensitivity of sensors the stability of the frequency of the device needs to be addressed. U.S. Pat. No. 6,122,954 discloses a SAW sensor with a resonant frequency range of 200 to 2000 MHz and a temperature control system. It is an object of this invention to improve the reliability of SAW sensors and to optimise the operational performance of the sensors.
BRIEF DESCRIPTION OF THE INVENTION
[0010] To this end the present invention provides a surface acoustic wave sensor which incorporates
a) a first layered SAW device consisting of a piezoelectric crystal with interdigital electrodes on its surface, and second piezoelectric layer over said interdigital electrodes b) a second layered SAW device consisting of a piezoelectric crystal with interdigital electrodes on its surface, a second piezoelectric layer over said interdigital electrodes and an analyte sensitive surface on said second piezoelectric layer c) both SAW devices are fabricated on the same substrate d) reflectors are located adjacent the interdigital electrodes in each saw device to reduce the bandwidth of the device e) the resonator circuits of each saw sensor incorporate amplifiers which are dependent.
[0016] When the SAW device interacts with a target analytes the operating frequency changes. The change of operating frequency is proportional to the magnitude of the target analyte in the environment. The oscillation system needs to have a high Q and a stable frequency response.
[0017] By using the first layered SAW device as a reference sensor and fabricating them on the same substrate the effect of environmental noise can be reduced. By using reflectors to reduce the bandwidth the Q of the devices is increased.
[0018] Preferably the piezoelectric substrate is cut for propagation of Love mode waves and may be quartz crystal, lithium Niobate [LiNbO 3 ], lithium tantalate [LiTaO 3 ], langasite or langatite.
[0019] Preferably the second layer is a piezoelectric film such as layer is zinc oxide, AlN LiTaO3, LiTaO3 or quartz
[0020] The second layer can be a non-piezoelectric which has a capability to confine the acoustic energy with itself such as silicon nitride, different types of metal oxides, polymers or metal compounds.
[0021] A preferred piezo substrate is 90° rotated ST-cut quartz crystal which has a propagation speed of 5000 m/s and the dominant wave is SSBW (Surface Skimming Bulk Wave) and has zero coupling to other modes. It is dominantly a Shear Horizontal (SH) bulk wave and has a low temperature coefficient. Its major disadvantage is a high insertion loss as it changes from SSBW to love mode. When a film material is deposited on the surface it should load the substrate which means the speed of propagation in the film is less than in the substrate. In this case the mode of propagation changes to Love mode. When metal oxides films are deposited on the substrate the insertion loss is decreased as the mode of operation changes from SSBW to Love mode. Its main advantage is a lower insertion loss as it decreases from SSBW to Love mode.
[0022] Other suitable substrates are the substrates that allow the generation of leaky SAWs. These include LST quartz, 64 YX-LiNbO 3 , 41 YX-LiNbO 3 and 36 YX-LiTaO3 substrates.
[0023] Other substrates cuts, which allow propagation of Rayleigh or other type of waves, can be used for gas sensing applications. Again addition of an acoustic confining layer increases sensitivity of the device.
[0024] Substrates that we have employed and tested are: ST cut quartz, XY and Yz LiNBO 3 , 128 X LiNbO 3 , 110 Bismuth germanium oxide, different cuts of LiTaO 3 , GaAs, langatite and langasite.
[0025] Different types of second layers are used: metal compounds, metal oxides, metal nitrides, binary compounds, polymers, nano-particle compounds and amorphous materials.
[0026] One of the simplest, most economic and most reliable methods of operating a SAW device is to place it in a feedback-loop. Implementing this, the system oscillates at a frequency, which is a function of the width of the finger pairs of the SAW device pattern and the speed of propagation of the delay line. A change in the operational frequency of the system is resulted from the change in the acoustic wave propagation speed which itself is changed via the interaction with an analyte.
[0027] A biologically sensitive layer is deposited on the second piezo layer of the second SAW device to interact with the appropriate biochemical components to be detected. A gold film may be deposited on the surface. Gold interacts with high affinity to proteins. It can be used with specific antibodies for antigen detection. This deposit can be made on a porous surface as well as a smooth surface. A simple SAW oscillator may contain and amplifier, a SAW device, an output coupler and a means of setting loop phase shift for instance via a length of a coax cable. The saturation of the loop amplifier provides the gain compression. A very important aspect in the design and implementation of a SAW sensing system, which operates based on an oscillator, is the stability of the frequency. Different types of phenomenon may cause a frequency deviations from the base frequency in a sensing system. They can be categorized as follow:
1—Random deviations generated by random noise 2—Drift as a constant frequency shift. This can be a short term or a long term drift 3—Electromagnetic effects. Although shielding dramatically reduces this effect but affinity of any metal or material with high permittivity to the system may generate a frequency change 4—Noise due to the mechanical component of the system such as pumps and injection of the analyte 5—Frequency changes caused by warming up of the electronic circuits and random noise generated in them
[0033] The frequency stability for a SAW oscillation system is divided into systematic and random categories:
1. Systematic are the predictable effects 2. Random effects are different regarding prediction and spectral densities than systematic effects
[0036] Random noises are generally difficult to quantify, as they are not a state of frequency which is changing at a specific time period. Furthermore, random noise value strongly depends on the number of samples and the total length of measurement. For the study of random noise, the spectra of the frequency are normally the most common parameters to inspect.
[0037] Among random noises, the parameter which has the most important effect on oscillation frequency, is the change in temperature. It has effect both on the SAW device and on the electronic components of the loop's amplifier.
[0038] The characteristics of the temperature coefficient of frequency is largely dependant on the cut of the crystal. Generally, the frequency change generated by the temperature change can be dramatically suppressed by employing a dual delay line device and looking at the difference of the two oscillations.
DETAILED DESCRIPTION OF INVENTION
[0039] The present invention adds to the proposals disclosed in WO 02/095940 the content of which is incorporated herein by reference.
[0040] FIG. 1 is a cross section of a saw sensor to which the invention is applicable;
[0041] FIG. 2 is a schematic illustration of a preferred sensor and analyser of this invention;
[0042] FIG. 3 illustrates the frequency shift performance of the invention;
[0043] FIG. 4 illustrates the random noise of a SAW device of the invention;
[0044] FIG. 5 illustrates the band width reduction achieved by the present invention;
[0045] FIG. 6 illustrates the response of the sensor of this invention to hydrogen gas;
[0046] FIG. 7 illustrates the response of the sensor of this invention to carbon monoxide gas;
[0047] FIG. 8 illustrates the response of the sensor of this invention to nitrogen dioxide gas;
[0048] FIG. 9 illustrates the response of the sensor of this invention to biochemicals in a liquid;
[0049] FIG. 10 illustrates the effect of ZnO SiO 2 layers on frequency shift;
[0050] FIG. 11 illustrates the mass sensitivity of layered SAW devices based on 36 LiTaO 3 and 64 LiNbO 3 with ZnO guiding layers;
[0051] FIG. 12 illustrates the effect of conductivity change vs layer thickness.
[0052] This invention provides piezoelectric layers on piezoelectric substrates. The Substrate's cut belongs to a class of crystal cuts that support Surface Skimming Bulk Wave (SSBW) and leaky wave for liquid sensing applications and other cuts for gas sensing applications. The layers are of different of piezoelectric materials that can be deposited as a highly directional film on the substrate, which let acoustic waves propagate onto its environment. Speed of propagation of acoustic wave in the layers must be less than the substrate to support Love mode of propagation, otherwise it allows other modes of propagation as well.
[0053] In FIG. 1 a first wave generating transducer 3 and a first receiving transducer 4 are fabricated onto the surface of a piezoelectric substrate 1 . The transducers 3 and 4 are any suitable interdigital transducer used in SAW devices. The wave transmitting layer 5 , a piezoelectric layer, is fabricated onto the substrate 1 such that the transducers 3 and 4 lie between the substrate 1 and the layer 5 .
[0054] A sensing layer 6 is deposited on to the wave propagation layer 5 to form a surface which is physically, chemically or biologically active, selectively to agents in the liquid or gaseous media to which the surface 6 is exposed. The surface may be treated to detect any biological target. For quality control in food production the surface can be treated to detect quantitatively the presence of Salmonella, E Coli, or other enteric pathogens. For environmental monitoring pathogens such as legionella can be detected.
[0055] The transitional layer 9 is preferably an acoustically sensitive layer such as SiO 2 which increases the velocity shift and as a result increases the electromechanical coupling factor. The transition layer 9 lies between the wave transmitting layer 5 and the substrate 1 so that the distance between the first IDT and layer 5 is increased to facilitate a higher coupling coefficient and reduce the acoustic wave transmission energy loss which otherwise occur. The protective layer 10 lies between the sensing layer 6 and the piezo layer 5 to protect layer 5 from damage. The protective layer 10 may be SiO 2 , other metal oxides, metal compounds or polymers.
[0056] In FIG. 2 the SAW device of this invention is shown in a detector device.
[0057] In FIG. 2 second wave generating transducer 7 and a second receiving transducer 8 above the substrate layer and below the wave transmitting layer and near the first generating transducers 3 and receiving transducers 4 . Both sets of transducers are located on the same substrate. No sensing layer is located above the second set of transducers 7 and 8 so that they can function as a reference sensor.
[0058] A frequency counter 11 determines frequency of the output signals and a computing device 12 calculates the concentration of the detectable components in the liquid or gaseous media. The output from the first receiver transducer 4 contains the sensing signal which is a consequence of the interaction between the sensing layer and the target molecules. The output from the second receiving transducer 8 contains only the operational characteristics of the sensing device because thee is no sensing layer 6 above it. This enables the analyser to compute accurately a signal indicative of the concentration of the target molecule.
[0059] There are many parameters which effects the long term stability. Generally a final bake of the device makes a SAW device more stable. It is believed that the diffusion of metal into crystal is reduced in time with such a bake. This bake may generate a saturated diffusion level which reduces the room temperature diffusion.
[0060] The spectral density of frequency fluctuations S(f) is the magnitude of the mean square frequency fluctuation in a 1 Hz bandwidth. Another parameter used for quantifying random-frequency fluctuations is Allan variance. Allan parameter is the average value of one half of the square of the fractional change in frequency between two adjacent frequency measurements.
[0061] The issue of frequency deviation for the SAW sensors has been investigated. The differences for a SAW sensing system are as follow:
1—The system is in touch with an analyte. This analyte can be either gas or liquid. Contact with such materials may generate extra noise in the system. It results in more unpredictable behaviour of the system. 2—Generally a layered SAW device is used for liquid sensing applications. Most of the available studies so far are conducted for blank SAW devices.
[0064] Even for a blank device, the source of the frequency noise in SAW oscillators is not generally well understood. Contact with different analytes dramatically increases the complexity of the system.
[0065] In this invenstion the following methods were employed to reduce noise of the system and increase the frequency stability of the oscillation frequency:
[0066] 1. Adding Gratings Between Transducers
[0067] Layered SAW devices are fabricated on to a crystal cut that allows the propagation of surface transverse wave (STW) (Leaky SAW and SSBW are in STW family). STW devices have:
Low device loss High intrinsic Q Low 1/f noise and low vibration sensitivity
[0072] Currently, STW based resonators are widely used in modern communication and wireless remote sensing, weapon guiding systems.
[0073] By the deposition of a guiding film a layered SAW device is fabricated. The way to move to fabrication of a stable sensor is to design a high Q SH resonator.
[0074] The SH-type acoustic waves are excited by means of IDTs in a direction perpendicular to X-axis on selected temperature compensated rotated Y-orientation on the piezoelectric substrate. If IDTs are separated by a free surface from each other then SH-wave is a SSBW (surface skimming bulk wave) or leaky wave. For these modes of propagations the power is radiate into the bulk of the crystal, which increases the insertion loss. If a metal strip grating with a period equal to that of the IDTs is depostited between IDTs it slows down the SSBW and leaky waves and changed them to STW. The wave energy is confined onto the surface and does not dissipate into the bulk of the device.
[0075] In this invention the grating may be patterned either in between the guiding layers or on the surface of the SAW sensors. In both cases the insertion losses are decreased more than 15 dB.
[0076] 2. Optimising Material Choice (For Example, the Use of Zinc Oxide)
[0077] Combination of different materials as the guiding layers and the substrate play a significant role in designing the sensitivity of the device. A layer with the shear horizontal speed of propagation less than that of the substrate usually confines the energy of acoustic waves into the layer. This near the surface energy increases the penetration of acoustic waves into the sensitive layer and target analytes. As a result, increasing the sensitivity of the device.
[0078] SAW wafers that allow the propagation of SSBW or leaky wave have to be employed for the fabrications of such devices. The guiding layers can be piezoelectric materials such as ZnO or non-piezoelectric materials such as SiO 2 and Si 3 N 4 .
[0079] 3. The Number of Reflectors
[0080] Adding Reflectors reduces the bandwidth in a SAW device. This will increase the Q of the device, which has a dramatic effect on the signal to noise ratio of the operating system. Adding reflectors decreases the bandwidth of the device. Adding more than 50 reflectors for SAW devices based on LiTaO3 and LiNbO3 substrates have increased the Q of the devices up to one order of magnitude. For ST-cut quartz based devices, more than 150 reflectors are required but it increases the Q of the device up to 15 times.
[0081] 4. Changing the Q of the Device by Changing the Cavity Length
[0082] Cavity length increases the Q of the device. For a better frequency stability the delay line should have a long delay time as possible. To ensure that only one frequency can satisfy the oscillation conditions at any given time, the combined length of the two transducers should be approximately no less than 90 percent of the centre-to-centre distance of the two transducers. The number of fingers in each transducers may be limited to approximately 120. Additional fingers can be used to achieve lower insertion loss, but this increases the undesirable influence of metal on turnover temperature and triple transit reflections.
[0083] A number of factors, such as propagation loss, physical size and phase error between groups of fingers contribute to limiting the length of the SAW transducer. At 400 MHz and achievable delay time for a single-mode delay line is about 4μ seconds.
[0084] Another advantage of large cavity size is that it increases the power handling capability of the resonator.
[0085] 5. Fabricate both Devices (the Reference and the Sensor) on the Same Substrate.
[0086] This will dramatically decrease the environmental effects. Noises have generally the same effect on both sensor and reference oscillation frequencies and shift them with an equal magnitude. Substraction of these two frequency suppress the effect of environmental noise on the system.
[0087] 6. Employing Dependant Amplifiers
[0088] The reference and sensor are better to be run by dependant amplifiers. The inventors have used arrays of transistors to reduce the effect of temperature on is the gain of the transistors and the environmental noise. When transistors are fabricated onto the same substrates then they show the same change in their gain, specially as temperature drifts.
[0089] Though the SAW device has by far the largest delay time of all oscillator components the other components play a significant role in the frequency stability of the oscillator.
[0090] In comparison to BAW resonators, SAW devices have one or two order of magnitude lower Q, as a result the influence of frequency stability of electronics is greater. To reduce the effect of stability of loop amplifier should have a large bandwidth. Employment of a negative feedback may help. It is also convenient to use a 50 ohm environment.
[0091] The best performance is obtained if bipolar silicon transistors are used as they give lower flicker noise than FETs. Their performance should not be sensitive to a source or load which is not exactly 50 ohm as in most cases SAW devices show different impedance than that of what they are designed for.
[0092] 7. Optimising the Aperture Size
[0093] Aperture size has an important role when the sensor is operating in contact with a liquid. A typical delay line, in air, will have an insertion loss of approximately 20 dB if 120 fingers are used in each transducers and the acoustic aperture is approximately 200 wavelengths.
[0094] In contact with liquid the phase shift of the SAW device decreases. A large aperture compensates such a decrease.
[0095] 8. Grooved Gratings
[0096] Grooved gratings usually give better frequency stability than metal grating since the only metal in the active acoustic area comes from the transducers. Despite such an advantage a larger cost may reduce the attractiveness of this method.
[0097] 9. Device Packaging and Sensitivity to Vibration
[0098] The long term frequency stability related to the effect of analyte onto the surface of the SAW device. Ultra clean liquid is required when test for the long term SAW stability is tested. Otherwise a continuous drift is observed.
[0099] The vibration sensitivity is strongly dependant on the details of how the SAW device is mounted and packaged. Although normally the magnitude of vibration is small compared to temperature effects and long term drifts. Change in pressure of the liquid cell has a significant effect on the device. Even the pressure can be changed by small drops of liquid trickling from the outlet of a liquid delivery system.
[0100] The behaviour of the sensor of this invention is shown graphically in FIGS. 3 to 9 . FIG. 3 shows the warming up of a SAW sensing system with and without applying the enhancement of the invention. Random noise is less and drift is smaller. System reaches a stable condition in a shorter time. FIG. 4 shows the random noise of the enhanced system of this invention.
[0101] FIG. 5 illustrates the reduction of the bandwidth of a SAW device before and 25 after introducing the changes. FIG. 5A shows the insertion loss of a SAW device before introducing the enhancements. FIG. 5B shows the insertion loss of a SAW device after introducing the enhancements. Bandwidth is at least 10 times smaller.
[0102] FIG. 6 illustrates the response of the layered SAW sensor (Structure: LiTaO 3 /ZnO/WO 3 /Au) to hydrogen gas.
[0103] FIG. 7 illustrates the response of the layered SAW sensor (Structure: LiTaO 3 /ZnO/WO 3 /Au) to CO gas.
[0104] FIG. 8 illustrates the response of the layered SAW sensor (Structure: LiNbO 3 /ZnO/InO x (20 nm)) to NO 2 gas.
[0105] FIG. 9 illustrates the response of the sensor of this invention to biochemicals in a liquid. The system shows a freq response linear to mass addition of the analyte in the solution for masses less than 500 ng for IgNAR. 100 ng, 200 ng, 200 ng and 500 ng of IgNAR has been introduced to the cell and then thoroughly washed.
COMPARATIVE EXAMPLES
[0106] Passive layers such as SiO 2 thin films are inefficient on 36 LiTaO 3 and Piezoelectric thin films such as ZnO have a better performance.
[0107] To show the mass sensitivity for SiO 2 layer different thicknesses of SiO 2 layers were deposited. The frequency shifts were measured.
[0108] On an approximately 100 MHz device the frequency shift is only 600 kHz for each μm of SiO 2 as shown in FIG. 10
[0109] As can be seenin FIG. 10 the frequency shift for a 1.5 μm ZnO/36 LiTaO 3 device is approximately 3 MHz but for a 3 μm SiO 2 devices is approximately 1.2 MHz.
[0110] The frequency shift for a 1.5 μm SiO 2 device is approximately 900 kHz
[0111] According to the measurements the ZnO/36 LiTaO 3 device is between 2.5 to 6 times more mass sensitive than SiO 2 /36 LiTaO 3 device depending on the layer thickness and the type of mass added.
[0112] Mass sensitivity comparison between ZnO/64° LiNbO 3 and ZnO/36° LiTaO 3 as two typical substrates for the fabrication of layered SAW devices have been presented.
[0113] As can be seen in FIG. 11 , the thickness for obtaining the optimum mass sensitivity for 64° LiNbO 3 is less than 36°LiTaO 3 . At this optimum thickness, the 64° LiNbO 3 is about 2.5 times more mass sensitive.
[0114] The advantages of 64° LiNbO 3 over 36° LiTaO 3 are:
1—ZnO layer is smaller 2—Mass sensitivity is larger 3—It can be fabricated on a smaller wafer area as the piezoelectric constant coefficient is larger and makes the structure smaller
[0118] However the temperature coefficient of frequency is larger for LiNbO 3 . The ZnO layer on both sides has to have the exact thickness to eliminate the effect of temperature change
[0119] The effect of conductivity change vs. the thickness of layer is shown in FIG. 12 Substrate 36 LiTaO 3 and layer is ZnO. WO 3 has been used as the selective layer to H 2 gas. 0.5% and 1% H 2 gas in air has been used in the measurements.
[0120] Magnitude of frequency shift vs ZnO thickness when exposed to H 2 . The device structure is ZnO/36 LiTaO 3 . The operational frequency is approximately 200 MHz.
[0121] FIG. 12 shows that the thickness of the layer has a significant effect on the conductivity and charge response of the device. Although this example is for gas sensing, the results are also applicable for the surface conductivity change which may occur in bio-sensing applications. The response in a bio-sensing situation will be some unknown combination of mass and conductivity contributions.
[0122] Those skilled in the art will realise that variations and modifications may be made to the invention as described without departing from the core teachings of the invention. | A surface acoustic wave sensor which incorporates: a) a first layered SAW device consisting of a piezoelectric crystal such as lithium niobate or lithium tantalate with interdigital electrodes on its surface, and second piezoelectric layer such as zinc oxide over said interdigital electrodes b) a second layered SAW device consisting of a piezoelectric crystal with interdigital electrodes on its surface, a second piezoelectric layer over said interdigital electrodes and an analyte sensitive surface such as gold on said second piezoelectric layer c) both saw devices are fabricated on the same substrate d) reflectors are located adjacent the interdigital electrodes in each saw device to reduce the bandwidth of the device e) the resonator circuits of each saw sensor incorporate amplifiers which are dependent. | 6 |
FIELD OF THE INVENTION
The present invention is related to an improvement for electroblowing a multiple layered sheet.
BACKGROUND OF THE INVENTION
Fabrics and webs made from fibers can be used in a variety of customer end-use applications, such as filtration media, energy storage separators, protective apparel and the like. A process to make these webs is electroblowing wherein a polymer solution is spun through a nozzle in the presence of an electrostatic field and a blowing or forwarding fluid to evaporate the solvent and form fibers that are collected on a screen. Typically, not all of the solvent is removed from the fibers at laydown requiring additional solvent removal processes. However, if too much solvent remains in the fiber at fiber laydown on the screen, then the web can stick to the screen resulting in web damage when removing the web from the screen. Also, if too little solvent remains in the fiber at fiber laydown on the screen, then the web does not exhibit sufficient tackiness for good surface stability to allow for web handling.
What is needed is a process for electroblowing a sheet structure that can be removed from the collection screen while having sufficient surface stability for handling.
SUMMARY OF THE INVENTION
The present invention is directed to a process for electroblowing a multiple layered sheet comprising spinning an electrically conductive liquid stream comprising a polymer dissolved in a solvent through at least two spinning beams comprising a linear array of spinning nozzles in the presence of a forwarding gas and an electric field to form fibers and deposit the fibers onto a collecting screen, wherein: (a) a first spinning beam provides fibers that are deposited onto the collecting screen with a solvent concentration of about 0 to about 30 weight percent that make a first web; and (b) a second spinning beam provides fibers that are deposited onto the first web with a solvent concentration of about 30 to about 70 weight percent that make a second web, wherein the difference in solvent concentration between the webs is at least about 10 weight percent.
DETAILED DESCRIPTION OF THE INVENTION
The present invention is related to an improvement for a multiple layered sheet made from webs produced by an electroblowing process described in World Patent Publication No. WO 03/080905, corresponding to U.S. patent application Ser. No. 10/477,882, incorporated herein by reference in its entirety.
The electroblowing method comprises feeding a stream of polymeric solution comprising a polymer and a solvent from a storage tank to a series of spinning nozzles within a spinneret, to which a high voltage is applied and through which the polymeric solution is discharged. Meanwhile, compressed air that is optionally heated is issued from air nozzles disposed in the sides of, or at the periphery of the spinning nozzle. The air is directed generally downward as a blowing gas stream which envelopes and forwards the newly issued polymeric solution and aids in the formation of the fibrous web, which is collected on a grounded porous collection screen above a vacuum chamber.
The polymer solution can be mixed with additives including any resin compatible with an associated polymer, plasticizer, ultraviolet ray stabilizer, crosslink agent, curing agent, reaction initiator and etc. Although dissolving most of the polymers may not require any specific temperature ranges, heating may be needed for assisting the dissolution reaction.
It has been observed that in preparing a web according to this electroblowing process, if the web contains fibers with too much solvent at laydown on the collection screen, then the web sticks to the screen causing damage to the web upon removal from the screen. The sticking problem can be averted if the web at laydown has a solvent concentration of about 0 to about 30 weight percent.
It has been further observed that in preparing a web according to this electroblowing process, if the web contains fibers with too little solvent at laydown on the collection screen, then the fibers do not have sufficient tackiness to stick to each other in order to develop enough surface stability to prevent web damage when handling the web. The surface stability can be improved if the web at laydown has a solvent concentration of about 30 to about 70 weight percent.
A multiple layered sheet according to the invention can be made by combining a low solvent containing web with a high solvent containing web that does not stick to the collection screen while providing sufficient surface stability for web handling. The multiple layered sheet can be made by spinning a polymer solution through a first spinning beam that provides fibers that are deposited onto the collecting screen with a solvent concentration of about 0 to about 30 weight percent to make a first web and a second spinning beam provides fibers that are deposited onto the first web with a solvent concentration of about 30 to about 70 weight percent to make a second web, wherein the difference in solvent concentration between the webs is at least about 10 weight percent.
One way to make webs with different solvent concentrations at laydown is to control the liquid stream throughput of the polymer solution exiting the spinning beam. The first web can be prepared by spinning the fiber from a spinning beam that has a liquid stream throughput per nozzle of about 0.5 to about 2.0 cc/hole/min. The second web can be prepared by spinning the fiber from a spinning beam that has a liquid stream throughput per nozzle of about 2.0 to about 4.0 cc/hole/min. The difference in throughput between the two liquid streams is at least about 1 cc/hole/min.
Another way to make webs with different solvent concentrations at laydown is to control the forwarding gas temperatures. The first web can be prepared by spinning the fiber with a first forwarding gas with a temperature of about 50° C. to about 150° C. The second web can be prepared by spinning the fibers with a second forwarding gas with a temperature of about 25° C. to about 50° C. The difference in temperature between the forwarding gases is at least about 25° C.
Alternative process variables that can be manipulated to independently control the fiber spun from each spinning beam to achieve the desired level of solvent concentration at laydown include spinning cell temperature and die to collector or beam to collection screen distance.
Additional spinning beams can be added to the process to deposit additional webs between the first and second webs, onto the second web or a combination of both.
The process further comprises removing the solvent from the collected webs to a desired solvent content depending on the end use.
A preferred polymer/solvent combination is polyamide dissolved in formic acid to prepare a polyamide multiple layered sheet.
TEST METHOD
Solvent Content in a web is measured by weighing the as produced web, then drying the web and reweighing the web and is calculated by the formula:
%
solvent
=
(
weight
of
solvent
containing
web
-
weight
of
solvent
free
web
)
(
weight
of
solvent
containing
web
)
×
100
%
EXAMPLES
Hereinafter the present invention will be described in more detail in the following examples.
Webs used to make a multiple layered sheet of the present invention can be produced by the electroblowing process described in World Patent Publication No. WO 2003/080905, corresponding to U.S. patent application Ser. No. 10/477,882, incorporated herein by reference in its entirety.
Comparative Example A
A web is prepared from a polymer solution having a concentration of 24 wt % of nylon 6,6 polymer, Zytel® FE3218 (available from E. I. du Pont de Nemours and Company, Wilmington, Del.) dissolved in formic acid solvent at 99% purity (available from Kemira Oyj, Helsinki, Finland). The polymer solution is electrospun at room temperature using blowing air at a temperature of about 50° C. and potential difference between the spinning beam and the collector of 50 kV. A spinning beam has a polymer solution throughput of about 4.0 cc/hole/min which produces fibers that are collected on a screen to form a web with about 60% formic acid content. The web sticks to the collection screen causing damage to the web when it is removed.
Comparative Example B
Another web is prepared in a similar manner to Comparative Example A except the spinning beam has a polymer solution throughput of about 1.0 cc/hole/min which produces fibers that are collected on a screen to form a web with about 25% formic acid content. The web does not stick to the collection screen when it is removed. However, the surface stability of the web is insufficient to stop damage to the web when handling.
Example 1
A multiple layered sheet according to the invention is made by combining Comparative Examples A and B in a specific order. As in Comparative Example B, a first spinning beam has a polymer solution throughput of about 1.0 cc/hole/min which produces fibers that are collected on a screen to form a first web with about 25% formic acid content. As in Comparative Example A, a second spinning beam has a polymer solution throughput of about 4.0 cc/hole/min which produces fibers that are collected on top of the first web to form a second web with about 60% formic acid content. The two webs produce a multiple layered sheet. The sheet is removed from the screen without sticking to the screen. Furthermore, the additional tackiness of the second web helps to hold the sheet together with good surface stability allowing the web to be handled. The multiple layered sheet is solvent stripped to remove residual formic acid. | A process for electroblowing a multiple layered sheet using multiple spinning beams to produce different component webs wherein the sheet doesn't stick to the forming screen and has improved web stability. | 3 |
BACKGROUND OF THE INVENTION
This invention relates to thermal insulating materials which may be installed during building construction in the manufacture of extreme weather clothing equipment and gear, auto or sea, and air crafts. More particularly, the invention relates to insulating material which minimize heat transfer through conduction by minimizing the cross-sectional area of contact, and minimize heat transfer through convection by evacuating any fluids from the system. Heat insulation utilizing vacuums are well known. However, insulations utilizing vacumms have generally been limited to containers which are relatively rigid. U.S. Pat. No. 3,179,549 which issued Apr. 20, 1965 to Strong, et al., is an example of this type of system. In that patent a panel including spaced wall is employed wherein the space between the walls is filled at least in part with a filler material comprising filaments of glass or materials of similar characteristics, and the filaments are oriented as perfectly as practicable in a plurality of substantially parallel planes being disposed at random in the parallel planes, the disposition of the planes being transverse or normal to the direction of heat flow between the walls. The space between the walls was evacuated and the filler material supported the walls in the desired space relationship against the inwardly acting force of the atmosphere. In another system described in U.S. Pat. No. 3,936,553, which issued on Feb. 3, 1976 to Rowe, the insulation material is described as having a pair of generally parallel space surface sheets of impervious materials sealed together through thermally insulating material at their free edges. The surface sheets were held together in space relation by a series of transverse pins spaced apart over the area of the surface sheets and the space between the later was evacuated. The edges of the surface sheets are sealed together by means of synthetic foam and the interior is evacuated. This system has the disadvantage that rigid material such as aluminum is used for the surface sheets. Sealing is effectuated by a joinder of dissimilar material which is undesirable for vacuum properties. No means for securing the panels to a wall or method of sizing the panels are disclosed.
The systems of the prior art had the disadvantages of being relatively rigid, heavy, or fragile, while at the same time being difficult to manufacture and relatively expensive. An additional disadvantage is that the seals have been inadequate for the maintenance of a vacuum. These systems are not suited for adaptation for use in different geometries. Rather they have to be custom made for each geometry.
SUMMARY OF THE INVENTION
In accordance with this invention there is provided insulation material comprising a pair of laminated flexible films, or film and metallic foil, surrounding a plurality of pellets of low conduction material. The pellets may be retained in place by a low conductive mesh or screen which provides for dimensional stability. The laminated flexible films are fused at the edges with a border provided for attachment to buildings or other fabrication.
BRIEF DESCRIPTION OF THE DRAWINGS
Further details are explained below with the help of the examples illustrated in the attached drawings in which:
FIG. 1 is a perspective with cutaway view of an insulation modular quilt;
FIG. 2 is a cross-section through the insulation modular quilt;
FIG. 3 is an alternative embodiment of an insulation modular quilt;
FIG. 4 is a cross-section through a piece of typical foam material;
FIG. 5 is a cross-section through a piece of foam material that has been subjected to a vacuum; and
FIG. 6 is an alternate embodiment of an insulation modular quilt.
DESCRIPTION OF THE PREFERRED EMBODIMENT
As shown in FIG. 1, a flexible insulation modular quilt 11 comprises two opposed flexible laminate films 12 and 13. Each flexible laminate film comprises a first flexible film 14 of soft plastic such as polyethylene, vinyl, or other similar plastics on the inner surface and an outer flexible film 15 of harder nylon polyester or similar harder plastic material or aluminum foil on the outer surface. The flexible laminate films 12 enclose a plurality of pellets 16 of low conduction material such as expanded polystyrene foamed pellets or other shaped fillers. The pellets 16 are used as structural members to maintain the spacing between the opposed flexible laminate films 12. The voids 17 between the pellets 16 and those within the foamed material are evacuated to provide a substantial vacuum in the insulation. The flexible laminate films 12 and 13 are sealed by fusing the softer polyethylene inner surface using conventional heat at the edges, so as to provide a margin 21 of sufficient width to accomodate conventional attaching means such as staples and the like. The combination of the use of low conduction pellets or other foamed shapes within an evacuated volume surrounded by a flexible envelope provides the advantage of good heat insulation while maintaining a flexible, easy to manage, insulation ensemble. The flexible laminate film 12 comprised of films 14 and 15 may be heat fused, glued, or sealed at the edges by any conventional means.
As can be appreciated from the description of the embodiment depicted in FIG. 1, the insulation panel provided above is not only flexible but quite malleable and may be conformed to a number of different shapes on the site. The embodiment of FIG. 2 is specially suited for applications where a more rigid form of insulation panel is desired, such as one that would retain its form once it has been bent to the desired form. As shown in FIG. 2 a mesh or screen of low conduction material 27 is used to maintain the position of the small bead-like pellets 16; to maintain dimensional stability along a plane under normal atmospheric pressure from the perimeters and sides; and to maintain flexibility when the enclosed volume is air evacuated thus permitting decrease in the thickness and bulk of the insulation as desired.
In order to provide for the manufacture of large sections of insulation and to prevent the destruction of the insulative qualities of an entire panel due to accidental tears of the laminate flexible film, an alternative embodiment shown in FIG. 3 is preferrable. In that embodiment a large sheet 31 of laminate flexible film is provided. The sheet 31 comprises a sheet of soft plastic material 33 such as polyethylene, vinyl or other similar plastic, bonded or coated where applicable, to a sheet of harder plastic material 35, such as nylon, polyester, acrylic or aluminum foil. A plurality of isolated groupings of pellets of insulating material 43 are provided in a repetitive pattern, with or without the intermediate mesh 27. The border 45 between each grouping 43 of insulating pellets is sealed by gluing, or heat fusing, thereby isolating each group of pellets from the other. The voids 17 between the pellets in each grouping 43 is evacuated. The insulation areas are therefore isolated one from the other and any accidental tear of the laminate film covering one of the groupings will not degrade the insulation quality of the entire quilt and allows repair by means of removal of damaged section and replacement with an undamaged module. A border 47 is provided so that the insulation quilt can be attached at the perimeter to a surface by conventional means. Also, panels or portions thereof consisting of one or more modules may be adhesively bonded to fabric, metals or other fabrication as required.
The advantage of utilizing foamed material as structural members to maintain the spacing between the opposed flexible laminate film 12 and 13 can be appreciated by reference to FIGS. 4 and 5. There are three types of heat transfer: conduction, convection and radiation. Of these only radiation can occur through a vacuum. Convection occurs in fluids, and conduction occurs both in fluids and in solids.
The basic relation for heat transfer by conduction was proposed by the French scientist, J. B. J. Fourier, in 1822. It states the qk, the rate of heat flow by conduction in a material, is equal to the product of the following three quantities:
1. k, the thermal conductivity of the material.
2. A, the area of the section through which heat flows by conduction, to be measured perpendicularly to the direction of heat flow.
3. dT/dx, the temperature gradient at the section i.e., the rate of change of temperature T with respect to distance in the direction of heat flow x.
To write the heat conduction equation in mathematical form, we must adopt a sign convention. We specify that the direction of increasing distance x is to be the direction of positive heat flow. Then, since according to the second law of thermodynamics heat will automatically flow from points of higher temperature to points of lower temperature, heat flow will be positive when the temperature gradient is negative. Accordingly, the elementary equation for one-dimensional conduction in the steady state is written
qk=-kA (dT/dx)
It is apparent from the formula above that by minimizing the area A, the rate of heat transfer is minimized.
The rate of heat transfer by convection between a surface and a fluid may be computed by the relation
q.sub.c =h.sub.c A T
where
q c =rate of heat transfer by convection, Btu/hr;
A=heat transfer area, sq. ft.; T=difference between the surface temperature T and a temperature of the fluid T at some specified location (usually far away from the surface, F;
h c =average unit thermal convective conductance (often called the surface coefficient of heat transfer or the convective heat-transfer coefficient) Btu/hr sq. ft. F.
Engineers have used this equation for many years, even though it is a definition of h c rather than a phenomeno-logical law of convection. The numerical value of h c in a system depends on the geometry of the surface and the velocity, as well as on the physical properties of the fluid and often even on the temperature difference T. One of the important physical properties of the fluid that affects the value of h c is density. The lower the density the lower the value of h c .
The microscopic cross-section of a piece of typical foam pellet 51, shown in FIG. 4, illustrates that such material is made of a plurality of shaped bubbles 52 contained within a matrix of plastic material 53. The shape of the bubbles 52 is due to the equal pressure that exists when the material is blown into expanded form. The lines 53 form the filament like grid due to many bubble walls being compressed together. The shape 52 is created by a mutually shared wall of many bubbles and are consequently very thin. Each bubble 52 contains gas such as air which can transfer heat both by conduction and by convection. The total rate of heat transfer is then sum of
q.sub.total =qk.sub.plastic qk.sub.gas +qc.sub.gas
where
qk plastic is the rate of heat transfer by conduction for the plastic.
qk gas is the rate of heat transfer by conduction for the gas bubbles, and
qc gas is the rate of heat transfer by convection through the gas in the bubbles.
When the foamed plastic material is subjected to a vacuum the material is modified. FIG. 5 shows a cross-section of such material which has been subjected to a vacuum. The walls of the bubbles 52 explode outwardly due to the pressure differential between the gas in the bubble and the exterior vacuums. As the bubbles burst the gas contained in the bubbles is evacuated so that what is left is a cribiform matrix of plastic material 53 of low conductivity, which under the load of atmospheric pressure does not totally collapse but deforms from the surface inwardly, leaving the matrix elements intact throughout the greater cross-section and intact but deformed at the points of pressure contact. Thus, heat flow channelization remains lengthy.
The pellet 51 which has been subjected to a vaccuum is incorporated into the insulation quilt 11 shown in greater detail in FIG. 6. The vacuum is maintained by the fusing of flexible laminate film 14 made as described above. With such a configuration heat transfer convection is reduced greatly because there is very little fluid contained in the insulation quilt. Conduction is also reduced because the cross-sectional of each pellet 51 is greatly reduced by the numerous holes left by the burst bubbles 52. The heat transfer by conduction is also reduced because the direction of positive heat flow x is increased in distance by being channelized along the filaments of the matrix only. That is the heat flow must now travel a circuitous route through the cribriform matrix of plastic material 53. Finally, heat transfer by radiation can also be decreased if a thin layer of highly reflective material 59 is bonded to the flexible laminate film 12 and/or 13. The end result is a highly efficient insulation quilt 11. | A flexible modular insulation quilt is disclosed having two thin flexible layers fused to the borders and surrounding a plurality of shaped foamed material in a vacuum. | 4 |
FIELD OF INVENTION
The present invention relates to a method and apparatus for testing materials, and more particularly, to a method and apparatus and for processing and testing asphalt-containing composite materials, such as bituminous paving mix used for producing asphalt concrete.
BACKGROUND OF THE INVENTION
Asphalt concrete is a useful material in the road construction industry. Federal and state guidelines require that asphalt concrete laid at certain thicknesses must have certain properties that evidence its safety and long-term performance. If these guidelines are not met, the roadway surface will fail over time when exposed to severe conditions of heat, cold, and moisture. Therefore, samples of asphalt concrete roadway material must be tested to determine proper composition and properties.
When employing composite materials, for example, a bituminous paving mixture, it is generally desirable to test the composition of the materials before installation to ensure that the installed material has desired properties of structural strength, durability, etc. For example, the "hot-mix" asphalt concrete used to pave roads, airport runways, etc., desirably has a predetermined proportion of asphalt binder to aggregate, and a predetermined gradation of aggregate size to help ensure that the material will have adequate and uniform application and wear properties.
Pyrolysis techniques which provide for both content and gradation analyses are known whereby the asphalt binder in a sample of asphalt is burned off to leave an aggregate residue. Pyrolysis techniques are generally described in "Historical Development of Asphalt Content Determination by the Ignition Method," by Brown et al., and in "Solvent-Free, Nuclear-Free Determination of Asphalt Content and Gradation of Hot-Mix Asphalt Concrete," by Todres et al., ASTM Journal of Testing and Evaluation, November 1994, 564-570.
According to these techniques, a sample of asphalt concrete is heated to volatilize and combust the asphalt binder, thus separating the binder from the sample and leaving an aggregate residue. However, insufficient temperatures may not completely separate the binder. Excessive temperatures can lead to aggregate loss and gradation changes induced by chemical changes and thermal shock in the aggregate. Several furnace-type apparatuses have been developed for performing asphalt pyrolysis, including furnaces which incorporate an integral weighing scale in order to allow measurement of a sample of asphalt concrete during pyrolysis as described in, for example, U.S. Pat. No. 5,081,046 to Schneider et al.
Variations in characteristics at installation sites also may lead to variation in combustion conditions. For example, a specimen of hot-mix asphalt may be divided into several samples which may be processed in different furnaces, even different furnaces at different testing sites. Variable combustion conditions in any of the furnaces may lead to inaccurate or nonuniform results among the furnaces. Moreover, nonoptimal combustion may lead to deleterious side effects such as poor emissions quality, formation of soot deposits in the furnace and exhaust system, and gaseous discharges into the testing site which may be harmful to personnel and equipment. Afterburners and filters may trap or burn some pollutants which otherwise might be discharged, but still may not produce the combustion and exhaust characteristics to the levels needed to reduce unwanted emissions.
Under currently practiced protocols, hot asphalt concrete samples are placed in stainless steel trays and positioned within a furnace that is pre-heated to an elevated temperature, typically in excess of 500° C. Inside the furnace, the sample is heated by conductive and convective heat transfer to achieve ignition. Heating the sample to the ignition temperature and thereafter combusting the asphalt binder content can require several hours or longer. Weight loss is measured during combustion by an internal balance incorporated in the furnace floor, and final asphalt content is determined.
It has now been discovered that these processes may be inherently inaccurate due to such factors as incomplete combustion, mineral loss, and aggregate gradation changes. For example, furnace temperatures may reach levels for periods of time that cause decomposition of some of the aggregate as well as the binder. In particular, extensive heating can cause cracking and decomposition of the aggregate, resulting in loss of aggregate from the sample and reduction of the aggregate particle size, adversely affecting the accuracy of the overall assay.
SUMMARY OF THE INVENTION
The present invention utilizes radiation heat transfer for pyrolyzing samples of a bituminous paving mix in order to ascertain the asphalt binder content. In a more specific aspect, the present invention uses an infrared heater which emits radiation at an infrared wavelength which heats the asphalt binder in the sample by radiation heat transfer and rapidly elevates the binder to its flash point temperature, at which it ignites. As the infrared heater continues to heat the ignited binder, the asphalt binder present in the sample is combusted. In addition, effluent gases discharged from the binder are also combusted.
The molecular structure of typical asphalt binder shows two infrared (IR) absorption bands at 3.4 μm and 7.0 μm. However, typical minerals in aggregate are less absorbent to infrared radiation with wavelengths of from 2 μm to 7 μm. For example, quartz, olivine, and orthoclase have absorption peaks at 9 μm. By irradiating the sample with radiation having wavelengths within the infrared spectrum, energy can be more efficiently transferred directly to the asphalt binder with less heating of the surrounding aggregate. The IR radiation is preferably emitted at wavelengths of from about 2 μm to about 7 μm, more preferably from about 2 μm to about 4 μm, to closely approximate the absorption bands of the asphalt binder. Hence, the selective heating of the binder results in minimized mineral loss and thermal degradation of the surrounding aggregate, as well as much faster ignition and combustion times.
According to one embodiment of the present invention, a method is provided for assaying the asphalt content of a bituminous paving mix. The method comprises the steps of:
placing a sample of a bituminous paving mix containing aggregate and a combustible asphalt binder in a sample container;
placing the sample container with the sample of bituminous paving mix in a combustion chamber;
exposing the sample to radiation from an infrared heater which emits radiation at an infrared wavelength;
heating the asphalt binder in said sample by radiation heat transfer from said infrared heater until said binder reaches its flash point temperature and ignites; and
continuing to heat the ignited binder in said sample by radiation heat transfer from said infrared heater while combusting the asphalt binder present in said sample and effluent gases discharged therefrom.
According to a further embodiment of the invention, an apparatus is provided for pyrolysis of a bituminous paving mix containing aggregate and a combustible asphalt binder. The apparatus comprises:
an oven having a floor, a top wall, and side walls defining a combustion chamber;
a sample support provided within said combustion chamber for receiving and supporting a sample of the paving mix;
an air inlet for admitting air into the combustion chamber;
an outlet for discharging combustion gases from the combustion chamber; and
a radiation source mounted within said oven, said radiation source being constructed and arranged for emitting radiation at an infrared wavelength toward said sample holder so as to heat the sample of paving mix by means of radiation heat transfer.
BRIEF DESCRIPTION OF THE DRAWINGS
While some of the objects and advantages of the present invention having been stated, others will be more fully understood from the detailed description that follows and by reference to the accompanying drawings in which:
FIG. 1 is a perspective view illustrating a preferred embodiment of an apparatus for analyzing composite materials according to the present invention;
FIG. 2 is a view of the IR radiation source embedded in the top wall of the oven chamber of the apparatus; and
FIG. 3 is a cross-sectional front view of the apparatus of FIG. 1.
DETAILED DESCRIPTION OF THE INVENTION
The present invention now will be described more fully hereinafter with reference to the accompanying drawings, in which a specific embodiment of the invention is shown. This invention may, however, be embodied in many different forms and should not be construed as being limited to the embodiments set forth herein. This illustrated embodiment is 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 thickness of layers and regions are exaggerated for clarity, and like numbers refer to like elements throughout.
FIGS. 1-3 illustrate one embodiment of an apparatus for analyzing and assaying asphalt-containing composite materials, e.g., asphalt concrete, roofing materials and the like, according to the present invention. As shown in FIG. 1, the apparatus includes an oven 100 having a floor 101, a top wall 102, opposing side walls 103, and a rear wall 104 which collectively define a combustion chamber 110. A door 113 is mounted to one of the side walls 103 by a hinge 115 for providing access to the combustion chamber 110. A window 117 in the door 113 allows viewing into the combustion chamber 110 when the door is closed. In the embodiment illustrated in FIGS. 1 to 3, the oven walls 101, 102, 103, 104, and door 113 are provided with a lining 300 of a refractory insulation material. However, the oven chamber may use other forms of insulation besides a refractory material, and may be lined by steel or other materials which are reflective to IR radiation so as to enhance the effect of the IR radiation by redirecting the radiation to the sample. It is further contemplated in a simplified embodiment, that no insulation or minimal insulation is required.
Provided within the chamber 110 adjacent the floor is a sample support adapted for receiving and supporting a sample pan 120 containing a sample of the paving mix. In the embodiment illustrated, the sample support comprises a pair of support rails 118. However, the sample support may take other forms, such as a flat panel or sheet. The support rails 118 are positioned above the floor 101 of the chamber 110 atop a plurality of posts 108 which pass through openings 109 in the floor 101, with the openings 101 preferably having a larger diameter than the posts 108 to allow air to enter the chamber around the posts 108. The lower ends of posts 108 are in turn supported by a weighing device, preferably a load cell 128 beneath the floor 101 of the combustion chamber 110. In this manner, a sample placed within the chamber 110 may be continuously weighed during the pyrolysis procedure.
An infrared heater 122 is mounted within the combustion chamber 110 adjacent the top wall 102 for emitting infrared radiation downwardly toward the sample contained in sample pan 120. The infrared heater includes a block 123 of a refractory material of high heat capacity which is heated by a heating element 124 to a high temperature such that the block radiates energy in the infrared spectrum. Any infrared heater capable of emitting radiation at a predetermined wavelength may be suitably employed. The heating element 124 for the infrared heater may be of the gas fired type or may comprise resistance electric heating elements. One suitable commercially available IR heater is the Casso-Solar type FHT infrared heater available from Casso-Solar Corp., Pomona, N.Y. According to the present invention, the infrared heater is operated at a temperature such that infrared radiation is emitted mostly in the wavelength range of from about 2 to about 7 um. This corresponds to the infrared absorption bands found in typical asphalt binder, and is outside of the range where most aggregate materials have their absorption spectra. For the specific infrared heater noted above, infrared energy of the desired wavelength spectra is emitted when the infrared heater block 123 is heated to a temperature of about 1000 degrees Celsius.
The temperature of the IR heater block 123 is monitored by a suitable temperature sensor 128, such as a thermocouple or thermistor, embedded in the block 123.
The temperature sensor is connected to a temperature controller 124, which controls operation of the heating element 123 to maintain a desired set point temperature. The heater block temperature and the set point temperature are displayed by a digital readout display 126 on the front panel of the oven. An additional temperature sensor 129 may be optionally provided within the combustion chamber for monitoring the chamber temperature.
In the embodiment illustrated, an exhaust outlet opening 111 is provided in a side wall 103 of the oven for discharge of combustion gases produced by pyrolysis of a sample of composite material. Exhaust pipes or ducts 130 may be directly connected to the exhaust outlet opening to carry the combustion gases directly into the atmosphere or into additional pollution treatment devices, or laboratory hoods or similar ventilation apparatus to which the outlet may be connected. Unlike the heavy black combustion gases which are produced when burning a sample in a conventional convection oven, the combustion gases produced from the infrared oven of the present invention are much cleaner, and if desired, may be released directly to the atmosphere without requiring filtration or afterburning. The infrared radiation is believed to be scattered by airborne smoke particles, increasing the efficiency of the oxidization of the smoke particles. However, an afterburner and/or filters optionally may be provided to further combust and/or trap airborne byproducts prior to their release into the atmosphere.
The oven may also be provided with an additional air inlet, preferably on the side wall 104 opposite the side wall where the outlet opening is provided. This air inlet may be provided with an adjustable air flow regulator 112 which can be adjusted to compensate for variations in the exhaust configuration characteristics of the particular installation. Those skilled in the art will appreciate that other embodiments of an adjustable airflow regulator may be used with the present invention. For example, the air intake control or regulator may be any type, but is preferably a rotatable or sliding shutter mechanism. A blower optionally may be included and may include an electrically-powered fan which may be controlled, for example, by a variable speed control which varies the speed of the fan to vary the output of the blower. The adjustable airflow regulator may also include, for example, a restrictable opening such as a mechanically or electromechanically actuated damper or similar device installed at the exhaust outlet housing, in portions of the exhaust system connected thereto, or at the holes in the floor of the oven chamber, which may be adjusted to vary the negative pressure produced by the blower and thus vary the rate at which gases are exhausted from the oven.
The sample pan or tray 120 may be made from any non-reactive material able to withstand repeated heating and cooling cycles. The preferred tray must have sufficient perforations to allow radiation to reach the sample from multiple directions. However, the tray material perforations must be small enough to retain composite material, such as aggregates which are left behind following the liberation of the asphalt from the sample. A wire mesh, or metal screen made from steel or stainless steel able to withstand temperatures in excess of 1200° to 1500° C. are particularly preferred. Other non-metal materials such as ceramics or other refractory materials may be used to make the trays.
Conventional furnace trays have a perforated stainless steel lid to reduce the loss of fine aggregates from the tray system during ignition. It was determined that the preferred trays for use with the apparatus of the present invention require no lid in order to provide maximum IR radiation transfer to the samples. However, the use of quartz or ceramic lids (highly transparent to infrared radiation) are also contemplated by the present invention.
In one embodiment of the present invention, the IR heater source is gas powered. Using such a heater would require only a small amount of electrical power for the controls, and optionally a blower fan. It is therefore contemplated that the gas fired infrared oven of the present invention could be electrically powered with a small battery thus making the unit portable and deliverable to work and testing sites. This would obviate the testing delay resulting from sending samples to testing facilities having ovens located remotely from the site where the asphalt composite is being made and applied.
The furnace of the present invention requires a shorter initial warm-up time than a conventional convection or conduction furnace, since it is only necessary to raise the infrared radiator block 123 to operating temperature, and it is not necessary that the entire combustion chamber be preheated to an elevated temperature. In fact, the operating temperature of the combustion chamber is considerably lower than that of a convection furnace. The IR furnace takes about 15 minutes to warm up whereas a conventional furnace needs a 1 to 3 hour warm up period. In addition, the use of the IR heater facilitates a shorter sample burn time. The IR furnace takes about 30-40 minutes to complete combustion whereas a conventional furnace needs at least 1 hour. Since the infrared radiation from the heater heats only the sample, and not the air in the combustion chamber, the overall temperature of the combustion chamber is much lower. The air is heated only by the combustion itself and by the heat of the sample.
In addition, it is further contemplated that no preheating time may be required, and that sample may be admitted to the IR furnace prior to activating the IR heater. The ignition and combustion times in this "cold start" mode will still be much faster than those obtained using convection-type furnaces.
Having a lower chamber temperature provides significant advantages. When a cold sample pan is first introduced into an oven, temperature differences between the relatively cold sample and its pan and the surrounding environment set up air currents. Because of the necessarily high operating temperature of a conventional convection oven, and resulting large temperature differences, significant air currents are created in the vicinity of the sample pan, which introduce weight measurement errors when attempting to measure the initial weight of the sample. The temperature differences are much lower in the furnace of the present invention, and the resulting air currents have minimal error introducing effect. Further, since the aggregates present in the sample are heated to lower temperatures and for shorter periods of time, changes to or losses in the aggregate as a result of charring, spalling or explosion are minimized. The use of the IR furnace therefore minimizes mineral losses and thermal degradation (alteration) of the aggregate. The minimized heating facilitated by the apparatus and methods of the present invention further minimize the risk of loss of minerals through calcination and also lowers the rate of carbonate dissociation; all of which affects weight measurement accuracy.
Still further, a lower chamber temperature is desirable to decrease the effect of temperature "plunge" as the oven door is opened to admit the sample trays. In convection ovens, opening of the furnace door realized a temperature drop on the order of 100° C. or more, which increased the reheating cycle time. The combustion chamber temperature in the furnaces of the present invention typically do not exceed about 300° C. during operating when empty, and only sustain a plunge of about 25° C. as the sample is admitted.
Overall, the chamber temperature is not critical with the present invention since the radiation is targeted specifically to the asphalt component of the composite sample. The asphalt is irradiated with IR radiation and heats up much more quickly, thus liberating byproduct gases from the asphalt which are then ignited in the furnace at much lower temperatures. The flash point of the asphalt gases is about 315° C. This is the highest temperature required by the furnaces of the present invention. Once the gas ignites, the sample will burn and the reaction temperature will rise in excess of 500° C.
In addition, since the overall internal chamber temperatures of the present invention are lower, infrared furnaces may not need thick refractory walls. This will provide a smaller, lighter structure, and economize manufacturing. This is important in allowing for the design of a portable structure that can be used on site.
The following example serves only to further illustrate aspects of the present invention and should not be construed as limiting the invention.
EXAMPLE 1
Combustion of Asphalt-Containing Composite Samples
Two stainless steel sample trays (2.125"×9"×13") were used to contain and orient the asphalt concrete. The tray had perforations having a 0.125" hole size with 0.1875" hole spacing. This perforation provided transmission to infrared radiation, with the stainless steel acting as a reflector for infrared radiation such that a sufficient amount of infrared radiation penetrated the perforated bottom of the top tray and heated the sample in the bottom tray. The perforations also provided adequate air circulation necessary for asphalt binder ignition and provided for a more complete asphalt burn. The sample trays were not covered in order to provide a more complete transfer of infrared heat from the infrared source to the sample on the top tray. A polished stainless steel flat plate was placed on a regular catch pan. Metal spacers of about 0.25" height were placed on the flat plate. On the spacers, were placed the two trays. The flat metal plate functions as act as a reflector for infrared and confine the radiation in the sample volume and keeps any fall-out of asphalt coated grains of aggregate near the bottom of the second pan. When the asphalt cement in the second pan ignited, the flames move towards the flat plate and ignite grains on the plate. The spacers provide good air circulation through the sample for quicker ignition and a more even and complete burn.
After powering up the infrared heaters, it took about 15 minutes to heat the infrared panel to 975° C. The chamber temperature was 185° C. The tray system was weighed using an external balance. A sample of 1000 g of hot asphalt on each sample tray (CC Magnum asphalt concrete with about 6.5% asphalt content, total sample weight about 2000 g). The sample was weighed in the tray system using an external balance. The tray system was then placed in the furnace. In less than 2 minutes, the asphalt in the top tray ignited, and the process continued igniting asphalt layer-by-layer downward. Within about 6-8 minutes, the asphalt in the bottom pan ignited. The chamber temperature reached a maximum of about 230° C. within 10 minutes after placing the sample into the furnace. When the burn was over, the sample tray system was removed from the furnace and allowed to cool down in open air. The total weight of the tray system was measured using the external balance.
Many modifications and other embodiments of the invention will come to mind in one skilled in the art to which this invention pertains having the benefit of the teachings presented in the foregoing descriptions and the associated drawings. Therefore, it is to be understood that the invention is not to be limited to the specific embodiments disclosed. In the drawings and specification, there have been disclosed typical embodiments of the invention and, although specific terms are employed, they are used in a generic and descriptive sense only and not for purposes of limitation, the scope of the invention being set forth in the following claims. | An apparatus and method for assaying an asphalt-containing composite material by irradiating the sample using a radiation source having a tunable preselected wavelength selected to closely approximate the absorbance wavelength of a particular material or materials found in the composite material to reduce the overall time and temperatures ordinarily needed to combust and assay such samples. | 8 |
CROSS-REFERENCE TO RELATED APPLICATIONS
This is a divisional of application Ser. No. 12/174,706, now U.S. Pat. No. 7,909,913 B2, filed on Jul. 17, 2008, which is incorporated herein by reference in its entirety.
BACKGROUND OF THE INVENTION
Hydrogen production is a multi-million dollar industry supplying high purity hydrogen for chemical producing industries, metals refining, petroleum refiners and other related industries. A typical commercial source for the production of hydrogen is the reforming of natural gas or other methane-rich hydrocarbon streams. The reforming is carried out by reacting the hydrocarbon with steam and/or with oxygen-containing gas (e.g. air or oxygen-enriched air), producing a hydrogen containing gas stream with accompanying amounts of oxides of carbon, water, residual methane and nitrogen. Unless it is desired to recover carbon monoxide, it is customarily converted to carbon dioxide by water gas shift (WGS) reaction to maximize the hydrogen content in the stream. Typically, this gas stream is then purified by adsorbing impurities using a regenerable solid adsorbent, usually regenerating the adsorbent by pressure swing adsorption (PSA) in a PSA unit. The PSA vessels generally contain a layer of activated carbon, for bulk CO 2 removal, followed by molecular sieve for CO and N 2 removal. A layer of activated alumina is sometimes used at the feed end of the bed for moisture removal. Other hydrogen-rich gas sources which can be upgraded by PSA technology to a high purity product include refinery off-gases with C 1 -C 6 hydrocarbon contaminants and effluent streams from partial oxidation units.
Precursors for hydrogen other than natural gas can be used for example coal, petroleum coke, biomass and other cheap precursors. The production of hydrogen from coal or petroleum coke typically would involve gasification or partial oxidation of the solid material. This gasification step combines coal, oxygen and steam at high temperature and pressure to produce a synthesis gas. The resultant synthesis gas can be treated by the water gas shift reaction (CO+H 2 O═CO 2 +H 2 ) to supplement hydrogen production.
The synthesis gas derived from gasification processes using coke, petroleum coke or biomass is inherently different from the synthesis gas produced by steam reforming of hydrocarbons like natural gas. In the case of steam reforming of natural gas, the resultant synthesis gas is very clean and contains a few impurities in the hydrogen-rich feed stream to the PSA. In the case of gasification-derived synthesis gas, the gas contains numerous impurities including sulfur species (H 2 S, COS, mercaptans), metals (Hg), various chlorides, carbonyls (Ni and Fe carbonyl), arsenic, heavy hydrocarbons, ammonia, HCN, olefins, diolefins, acetylenics and aromatics. The presence of these species in the synthesis gas presents a problem for the PSA system. Some of these species like carbonyls, heavy hydrocarbons and aromatics will be very strongly adsorbing and hence difficult to desorb. If these strongly adsorbing components do not desorb during the regeneration step, the capacity of the PSA decreases and the hydrogen production rate of the PSA decreases. Other species, e.g. the sulfur species, can react with the adsorbent surface resulting in sulfur plugging of the adsorbent (and consequent loss in adsorption capacity). This is especially a problem with H 2 S since the concentration of this impurity in gasification-derived synthesis gas can be up to 5 vol %.
Other important aspects that need to be considered with non-natural gas derived synthesis gas are as follows. Small, unreacted amounts of oxygen may be present in the synthesis gas stream. The presence of oxygen in the synthesis gas stream greatly enhances the amount of sulfur deposition on adsorbents via the reaction H 2 S+½O 2 =S+H 2 O. Also, nitrogen in significant concentrations can be present in the synthesis if air is used for the oxidation process. To produce high purity hydrogen, this nitrogen must be removed by the PSA. For this nitrogen removal step, a zeolite adsorbent is required. Since H 2 S is very strongly adsorbed on zeolites, care must be taken in the PSA design to ensure H 2 S does not reach the N 2 -removing zeolite layer. Finally, CO removal from the synthesis gas will be required. CO removal will require a zeolite adsorbent which as in the case of N 2 removal must avoid contact with H 2 S.
Gasification systems have also recently been considered for clean power production with reduced CO 2 emissions. The solid carbonaceous fuel is gasified to synthesis gas, shifted in a sour WGS reactor, cooled, and separated into a CO 2 /H 2 S containing stream and a decarbonized H 2 product stream. The latter is combusted with air or oxygen-enriched air in a gas turbine to produce power with essentially N 2 and H 2 O in the vent stack. In this case, high purity H 2 (99.9+%) is not necessary. Generally the process goal is to remove 50-90% of the carbon species in the syngas feed—some of the carbon species can be tolerated in the product H 2 gas. High recovery of H 2 is critical for successful implementation of this approach since it impacts the solid fuel feed rate to the gasifier and hence the size of all of the equipment from gasifier to H 2 PSA. Integration of the separation process with the rest of the power generation process is also vital.
In most gasification to hydrogen schemes an acid gas removal system is employed prior to the PSA. This acid gas removal step (typically done by absorption with amines, cold methanol, glymes etc.) keeps H 2 S away from the PSA ensuring a robust system. If the gasification-derived synthesis gas could be fed directly into a PSA, then the cost and expense of the acid gas removal system could be avoided.
Typical H 2 PSA systems used for upgrading synthesis gas derived from natural gas will quickly lose performance over time (lower H 2 production rate, lower H 2 recovery) if used in the same way to purify gasification derived synthesis gas owing to the different impurities present.
Thus, it would be desirable to provide a robust adsorption system which can tolerate all the impurities present in gasification-derived synthesis gas.
Previous proposals for dealing with the production and purification of H 2 by pressure swing adsorption (PSA) from gas streams that contain significant amounts (1 vol % and higher) of sulfur containing species like H 2 S primarily fall into two categories: 1) art which shows that H 2 S and acid gases should be removed prior to the PSA and 2) art which suggests that H 2 S can be put directly into a PSA system, although generally without addressing specific issues relating to the stability or longevity of the process.
U.S. Pat. No. 4,553,981 teaches a process to produce high purity H 2 (99.9+%) from gas streams obtained by reforming of hydrocarbons, partial oxidation of hydrocarbons and coal gasification. The system consists of a synthesis generator (e.g. a gasifier), a water gas shift reactor (to convert CO and H 2 O to CO 2 and H 2 ), a liquid scrubber and a PSA system. The liquid scrubber is used to remove acid gases (like CO 2 and H 2 S) from the feed stream prior to the PSA. Other references that suggest H 2 S removal should be accomplished prior to introduction into the PSA include U.S. Pat. No. 5,536,300; GB 2,237,814 and WO 2006/066892.
U.S. Pat. No. 4,696,680 teaches putting an H 2 S containing feed directly into a PSA bed. It is said that H 2 S can be selectively and reversibly removed from coal-derived synthesis gas using either activated carbon and/or zeolite adsorbents.
US 2002/0010093 appreciates the fact that reaction of activated carbon with H 2 S can occur in H 2 PSA processes. To obviate this, the activated carbon is acid washed prior to use. The acid washing step removes inorganic impurities which may help catalyze the formation of elemental S in the adsorbent pores. This reference also teaches a layered bed approach to H 2 production from an H 2 S containing stream which consists of a first layer of alumina or silica gel, a second layer of acid washed carbon and a final layer of zeolite.
U.S. Pat. No. 5,203,888 teaches a pressure swing adsorption process for the production of hydrogen where H 2 S could be present in the feed gas and that suitable adsorbents include molecular sieves, carbons, clays, silica gels, activated alumina and the like. U.S. Pat. No. 6,210,466 similarly teaches that H 2 S can be put directly into a PSA to produce purified methane.
EP 486174 teaches a process for producing hydrogen via partial oxidation of various hydrocarbon feedstocks (e.g. refinery off-gas). The synthesis gas produced by this process could contain high levels of H 2 S (up to 4 vol %). The synthesis gas produced is passed directly into a PSA for H 2 purification. There is no reference to the preferred PSA cycle or adsorbents required.
US 2005/0139069 teaches a process for the purification of a hydrogen stream that contains H 2 S. The adsorbent materials cited for the application include carbon, zeolite, alumina and silica gel. The PSA is coupled with an integrated compressor for recycle of purge or residual gas to the hydrodesulfurization process.
U.S. Pat. No. 4,696,680 states as adsorbents activated carbons, zeolites, or combinations thereof. Izumi et al (Fundamentals of Adsorption; Proc. IVth Int. Conf. on Fundamentals of Adsorption, Kyoto, May 17-22, 1992) concludes that the best H 2 S adsorbent is silicalite or alumina.
U.S. Pat. No. 7,306,651 states that the H 2 PSA beds should consist of at least two adsorbents chosen from activated carbons, silica gels, aluminas or molecular sieves, preferably with ‘a protective layer composed of alumina and/or silica gel at the feed end of the bed.
U.S. Pat. No. 5,797,979 teaches the separation of H 2 S from gas streams using ion exchange resins. Useful materials are macroreticular anion exchange resins containing a basic anion for which the conjugate acid has a pK a value ranging from 3 to 14. Specific examples are the fluoride or acetate form of Amberlyst A26 resin. The resin contains a quaternary ammonium moiety and either fluoride or acetate counterions. A cited H 2 S capacity for the fluoride containing resin was 1.0 mmol/g at 25 C and 0.05 atm H 2 S. Adsorption occurs via a chemical reaction between H 2 S and the basic anion as described in Sep. Sci. Tech, 38, 3385-3407 (2003). Regeneration of the H 2 S free adsorbent was accomplished by heating to 50 C while purging with inert gas, humidified inert gas, or dynamic vacuum.
A PSA or other swing adsorption purification of hydrogen would normally be operated using hydrogen as a purge and repressurisation gas. The beneficial use of nitrogen purge or repressurization has been proposed. U.S. Pat. No. 4,333,744 describes a ‘two-feed PSA process’ in which a portion of the PSA feed gas is first sent to a CO 2 separation unit and the CO 2 -lean product gas is processed in the PSA followed by the remaining PSA feed gas. N 2 can be used as a purge gas or a repressurization gas to form an ammonia synthesis gas.
U.S. Pat. No. 4,375,363 described the use of nitrogen purge and repressurization in a typical PSA cycle to produce a nitrogen/hydrogen product used for ammonia synthesis. High pressure nitrogen is used to help displace hydrogen from the bed after the feed step, again for the production of ammonia synthesis gas. U.S. Pat. No. 4,414,191 extends this approach by utilizing a nitrogen purge step at elevated pressure, to incorporate more of the nitrogen in the H 2 product.
U.S. Pat. No. 4,578,214 utilized a nitrogen purged PSA unit integrated with a fuel cell system to produce ammonia synthesis gas. The fuel cell provides electrical power and supplies the source for the N 2 stream (O 2 -depleted air).
U.S. Pat. No. 4,813,980 describes production of ammonia syngas via a PSA process utilizing two sets of adsorber beds, one to remove CO 2 and the second to remove other impurities, from a feedstock consisting of bulk H 2 , CO 2 , and N 2 and <10% other impurities. The beds of the second set are purged and repressurized with a nitrogen-containing gas. This gas could be a portion of the N 2 /H 2 product, a recycle stream from the ammonia process, or N 2 obtained from other sources.
U.S. Pat. No. 4,696,680 describes the use of a guard bed for hydrogen sulfide removal upstream of a separate vessel for PSA purification of hydrogen by the removal of other impurities. The guard bed contains activated carbon, zeolites, or combinations thereof for removing both hydrogen sulfide and carbon dioxide.
WO2005/118126 teaches a bed of chemisorbent (e.g. ZnO) as a guard bed to remove H 2 S prior to a H 2 PSA. The ZnO bed works by reaction of with H 2 S and is not a regenerable bed. Also, the H 2 S concentration in the feed gas in '126 is only in the ppm range because the source of H 2 is natural gas.
BRIEF SUMMARY OF THE INVENTION
The present invention now provides in a first aspect a process for the removal of hydrogen sulfide from a feed gas containing at least hydrogen sulfide as an impurity, said process comprising contacting the feed gas with an adsorbent for hydrogen sulfide, and adsorbing hydrogen sulfide from said feed gas to produce a hydrogen sulfide depleted feed gas, said adsorbent for hydrogen sulfide having a sulfur deposition rate of less than 0.04 wt % S per day H 2 S exposure when continuously exposed to a 1% H 2 S dry gas at 20° C. (these conditions hereinafter being implicit in the term ‘sulfur deposition rate’).
In an alternative aspect, the invention includes a process for the removal of hydrogen sulfide from a feed gas containing at least hydrogen sulfide as an impurity, said process comprising contacting the feed gas with an adsorbent for hydrogen sulfide, and adsorbing hydrogen sulfide from said feed gas to produce a hydrogen sulfide depleted feed gas, said adsorbent for hydrogen sulfide having an average loss of adsorption capacity for carbon dioxide upon accumulation of sulfur on the adsorbent produced by continuous seven day exposure to a 1% H 2 S dry gas at 20° C. of less than 2.0% capacity loss/wt % S loading, more preferably less than 1.8, still more preferably less than 1.6.
The adsorbents may be used to adsorb both carbon dioxide and hydrogen sulfide, or may be used as a guard bed upstream of a separate carbon dioxide adsorbent. As discussed above, various adsorbents for removing H 2 S from a gas stream such as hydrogen have been proposed, including activated carbons, aluminas and silica gel. Our studies indicate however that there are significant differences in the performance of these and other adsorbents over time. It has been found that elemental sulfur or sulfur containing compounds will accumulate in such adsorbents and will not be removed by the normal process of adsorbent regeneration in for instance a PSA process. Different adsorbents will accumulate sulfur at different rates. The accumulation of sulfur on the adsorbent will gradually decrease the capacity of the adsorbent to adsorb H 2 S and also its capacity to adsorb CO 2 , which will be relevant where the bed is intended to adsorb both impurities.
This rate of sulfur deposition can be measured by passing an H 2 S containing feed gas continuously over an adsorbent to be tested, withdrawing a sample of the adsorbent and measuring its sulfur content and continuing the process and repeating the measurements. The H 2 S concentration in the gas throughout the adsorbent bed will after a relatively short time rise to the inlet concentration as the bed's capacity to adsorb H 2 S is exhausted. The sulfur deposition rate is then calculated by measuring the change in sulfur wt % (i.e. final S wt %−initial S wt %) divided by the days of continuous H 25 exposure.
The experimental set up used is not critical, but the sulfur deposition rate is dependent on certain parameters that should therefore be standardized and controlled. In particular, it is dependent on the water content of the feed gas and the temperature. It is also dependent on the H 2 S concentration in the feed gas
A suitable protocol is as follows. A test column is prepared containing a packed bed (e.g., 1″ (2.5 cm) inside diameter×8″ (20 cm) long stainless steel tube) of the adsorbent under test. Thirty to 100 grams of the adsorbent are packed into the column. A dry gas mixture containing by volume 1% H 2 S, 8% CO, 37% CO 2 and balance H 2 is passed through the bed at 350 cm 3 /min at 400 psig (2758 kPa) and 20° C. Samples are taken from the feed end of the adsorbent at intervals Sulfur content is measured using X-ray fluorescence analysis.
A plot of wt % sulfur against days H 2 S exposure may not be linear. However an average value for the sulfur deposition rate may be obtained by drawing a straight line through the initial sulfur wt % and final sulfur wt % values. Seven days exposure is a suitable period. The slope of the resulting line is defined as the sulfur deposition rate. Thus, the sulfur deposition rate is calculated by measuring the change in sulfur wt % (i.e. final S wt %−initial S wt %) divided by the days of continuous H 2 S exposure. Seven days exposure is a suitable period.
Furthermore however, the impact of the sulfur on the capacity of the adsorbent for impurity gases such as H 2 S and carbon dioxide also varies. Some adsorbents we find can tolerate accumulating sulfur better than others.
This can be measured by passing an H 2 S and CO 2 containing feed gas over an adsorbent to be tested, periodically regenerating the adsorbent by desorbing adsorbed H 2 S and CO 2 therefrom, withdrawing a sample of the adsorbent and measuring its sulfur content, and measuring the CO 2 capacity of the adsorbent, and continuing the process and repeating the measurements. The CO 2 capacity may be considered to be of interest both in its own right and as a surrogate measurement for H 2 S capacity as the two gases behave similarly and measuring CO 2 capacity is more convenient.
As the sulfur content of the adsorbent gradually increases, changes in the capacity of the adsorbent for CO 2 will be observed. The experimental set up used is not critical, but a suitable protocol is as follows. A test column is prepared containing a packed bed (e.g., 1″ (2.5 cm) inside diameter×8″ (20 cm) long stainless steel tube) of the adsorbent under test. Thirty to 100 grams of the adsorbent are packed into the column. A dry gas mixture containing by volume 1% H 2 S, 8% CO, 37% CO 2 and balance H 2 is passed through the bed at 350 cm 3 /min at 400 psig (2758 kPa) and 20° C. Samples are taken from the feed end of the adsorbent at intervals following a bed purge using N 2 at 100 cm 3 /min, 400 psig (2758 kPa) for 24 hours at 20° C. Sulfur content is measured using X-ray fluorescence analysis. Carbon dioxide capacity is measured in a TGA by first heating the samples to 200° C. in flowing N 2 to remove volatile components, cooling to 40° C. in N 2 , and then exposing the sample to CO 2 at 1 atmosphere at 40° C. and measuring its weight gain.
A plot of % capacity loss against sulfur content may not be linear. However an average value for the CO 2 capacity loss per wt % sulfur loading may be obtained from a plot of relative CO 2 capacity (i.e. actual CO 2 capacity/initial CO 2 capacity) against S loading by drawing a line through the initial and final values. A period of 30 days exposure is suitable.
As shown below, we have found that certain materials suggested in the prior art analyzed above suffer a more rapid accumulation of sulfur than others and also that certain such materials suffer a significantly more severe loss of capacity for a given sulfur loading than others. Activated carbons and activated alumina perform significantly less well than silica gel. However, whilst the art has until now drawn no distinction between commercially available silica gels for use in hydrogen purification, we have found that high purity silica gels, having therefore a low alumina content, perform substantially better than a commercial grade of silica gel exemplified by Sorbead Plus from Engelhard which contains 1% or more of alumina. Alumina is included in such silica gels in order to provide resistance to loss of mechanical strength upon exposure to water.
Preferably, the sulfur deposition rate of the adsorbent is less than 0.01 wt % S/day, more preferably less than 0.0075 and still more preferably less than 0.004.
Accordingly, according to the invention, the adsorbent may preferably comprise or consist of a silica gel having an SiO 2 content of at least 99% (hereinafter referred to as ‘high purity silica gel’. Preferably the SiO 2 content is at least 99.2%, more preferably at least 99.5%, e.g. 99.7% by weight.
Preferably, the adsorbent may comprise an upstream (with respect to the direction of feed of the feed gas) portion of relatively low surface area high purity silica gel and a down stream portion of relatively high surface area high purity silica gel. The surface area of the relatively low surface area silica gel may for instance be below 400 m 2 /g and the surface area of the relatively high surface area silica gel may for instance be above 600 m 2 /g.
Other adsorbents having a better performance than Sorbead Plus are also preferred. These, as will be shown, include titania. Accordingly, the adsorbent for hydrogen sulfide may comprise or consist of titania. Suitable titania adsorbents include Hombikat K03/C6 from Sachtleben Chemie GmbH and CRS 31 from Axens.
Preferably, the feed gas contains at least 0.2 vol % hydrogen sulfide, more preferably at least 1%, more preferably at least 2%. The hydrogen sulfide content may for instance be up to 5%. Preferably the feed gas is hydrogen rich and the process is one for producing purified hydrogen. For instance, the feed gas may contain at least 50 vol % hydrogen. Preferably, the principal impurity by volume to be removed is carbon dioxide. Thus, the feed gas may contain at least 80 vol % of hydrogen and carbon dioxide combined and may contain at least 20% or at least 30% carbon dioxide.
In certain preferred embodiments, the feed gas contains hydrogen as a desired component and at least hydrogen sulfide and carbon dioxide as impurities and purified hydrogen is obtained as an end product by contacting the feed gas with a single homogeneous adsorbent which has a sulfur deposition rate of less than 0.04 wt % S per day H 2 S exposure. Thus, the use of layered beds containing a number of different adsorbents for different impurities may be avoided.
This further makes it possible to refresh the adsorbent progressively as it reaches the end of its working life if sulfur accumulation renders it partially inoperative. Some of the adsorbent can be removed from the upstream end of the vessel containing the adsorbent, which may then be topped up from the downstream end of the vessel. To facilitate this, it is preferred that the vessel be oriented such that an inlet for feed gas is at or toward the lower end thereof and the feed gas flows upwardly to reach an outlet from the vessel.
Said feed gas is preferably a synthesis gas produced by gasification of a carbon source which is solid or liquid at STP, followed by a water gas shift reaction. Gasification is conventionally carried out by treating the carbon source with steam and either oxygen or air. Alternatively, the feed gas may be a carbon monoxide and hydrogen mixture containing impurities which is produced by a said gasification, without the water gas shift reaction.
In a second aspect, the invention provides a process for the removal of hydrogen sulfide from a feed gas containing at least hydrogen sulfide as an impurity, said process comprising contacting the feed gas with an adsorbent for hydrogen sulfide, and adsorbing hydrogen sulfide from said feed gas to produce a hydrogen sulfide depleted feed gas, wherein the adsorbent for hydrogen sulfide comprises or consists of a cross-linked resin having no ionic groups and no hydrogen sulfide reactive functional groups.
Whilst the sulfur deposition rate and CO 2 capacity sensitivity to sulfur loading is not necessarily as good as a conventional silica gel such as Sorbead Plus, these resins have the advantage that they are more hydrophobic so that their CO 2 capacity may be less sensitive to water where that is a component of the feed gas.
Features indicated to be preferred above in relation to the first aspect of the invention may be applied to the second aspect also. The resin may be used as a single homogeneous adsorbent as described above and may be used in combination with one or more or all of the adsorbents described with reference to the first aspect of the invention.
The invention includes apparatus for use in purifying hydrogen by removal of impurities from a hydrogen feed gas, said apparatus comprising a flow path for said feed gas containing an adsorbent for hydrogen sulfide, said flow path having a feed direction, and said a sulfur deposition rate of less than 0.04 wt % S per day H 2 S exposure, and an adsorbent for carbon dioxide in said flow path downstream in said feed direction from said adsorbent for hydrogen sulfide.
The apparatus may further comprise a gasifier for steam reforming of a carbon source and a water gas shift reactor for producing said hydrogen feed gas connected in said flow path and located upstream with respect to said feed direction from said adsorbent for hydrogen sulfide.
The apparatus may further comprise an air separation unit (ASU) for producing separate flows of nitrogen and of oxygen respectively, said flow of oxygen being directed to said gasifier.
The apparatus may further comprise a power generating combustor connected to receive hydrogen purified by said adsorbent for hydrogen sulfide and said adsorbent for carbon dioxide and further connected to receive said flow of nitrogen to act as a diluent for combustion of said purified hydrogen in said combustor. The combustor is suitably a gas turbine.
Preferably, said flow of nitrogen is connected to flow counter current to said feed direction as a regeneration gas flow through said adsorbent for hydrogen sulfide and the apparatus further comprises a flow controller for selecting between feed gas flow through said adsorbent for hydrogen sulfide and regeneration gas flow therethrough. The invention includes in a further aspect a process for the purification of a hydrogen rich feed gas containing at least carbon dioxide and hydrogen sulfide as impurities, comprising contacting the feed gas with a first adsorbent contained in a first adsorbent vessel and thereby removing hydrogen sulfide from said feed gas to form a hydrogen sulfide depleted feed gas and contacting said hydrogen sulfide depleted feed gas with at least a second adsorbent contained in a second adsorbent vessel to remove at least carbon dioxide from said hydrogen sulfide depleted feed gas, and at intervals regenerating said first adsorbent and at different intervals regenerating said second adsorbent, wherein said first adsorbent is silica gel, titania, or a cross-linked resin having no ionic groups and no hydrogen sulfide reactive functional groups.
This aspect of the invention includes apparatus for use in purifying hydrogen by removal of impurities from a hydrogen feed gas, said apparatus comprising a flow path for said feed gas containing a first adsorbent in a first adsorbent vessel for adsorbing hydrogen sulfide, said flow path having a feed direction, a second adsorbent in a second adsorbent vessel for adsorbing at least carbon dioxide in said flow path downstream in said feed direction from said first adsorbent vessel, a source of at least one regeneration gas, a regeneration controller for at first intervals directing a regeneration gas from said source of regeneration gas to regenerate said first adsorbent, and for at second intervals directing a regeneration gas from said source of regeneration gas to regenerate said second adsorbent, wherein said first adsorbent is silica gel, titania, or a cross-linked resin having no ionic groups and no hydrogen sulfide reactive functional groups. The first adsorbent vessel (guard bed) may contain further adsorbents, e.g. as separate layers, for removing other impurities, such as metal carbonyls, aromatics, heavy hydrocarbons, or other sulfur containing species such as mercaptans.
The first adsorbent containing vessel (or guard bed) may preferably contain an upstream portion of lower surface area silica gel and a downstream portion of higher surface area silica gel, each of the kind previously described.
Regeneration of the guard bed may be by waste gas from the regeneration of the carbon dioxide adsorption or may be by ASU nitrogen, even where the carbon dioxide regeneration is by hydrogen. Also, the manner of the regeneration of the guard bed and carbon dioxide adsorbent bed may be different, e.g. the former being by TSA or a variant thereof (e.g. TPSA or TEPSA) or VSA, whilst the carbon dioxide adsorbent is regenerated by PSA.
BRIEF DESCRIPTION OF SEVERAL VIEWS OF THE DRAWINGS
FIG. 1 shows graphs showing rates of sulfur deposition on various adsorbents;
FIG. 2 shows plots of sulfur deposition on various adsorbents from a wet feed gas;
FIG. 3 shows the effect of sulfur deposition on the relative carbon dioxide adsorption capacity of various adsorbents, the lowest S loading performance being shown enlarged in FIG. 3 a;
FIG. 4 shows a schematic arrangement of apparatus for producing high purity hydrogen;
FIG. 5 shows plots showing the effect of temperature on the rate of sulfur deposition on two grades of silica gel;
FIG. 6 shows a schematic arrangement of apparatus for producing high purity hydrogen including a guard bed for hydrogen sulfide removal;
FIG. 7 shows a schematic arrangement of apparatus for producing purified hydrogen and for combusting the same for power generation;
FIG. 8 shows plots of the hydrogen recovery percentage against the amount of purge gas used in scenarios described below; and
FIG. 9 shows a plot of the hydrogen recovery percentage against feed productivity in scenarios described below.
FIG. 10 shows the effect of hydrogen sulfide exposure on the carbon dioxide capacity of various adsorbents.
DETAILED DESCRIPTION OF THE INVENTION
The current invention, in typical embodiments, provides a PSA process for the production of an enriched hydrogen product stream in which the feed gas contains at least 0.2 vol % (2000 ppm) H 2 S. The invention is not however limited to the use of PSA. As discussed above, H 2 S can react with various adsorbents surfaces and over time result in plugging of the adsorbent with elemental sulfur. This adsorbent plugging with elemental sulfur reduces the adsorption capacity of the adsorbent which lowers the performance (lower H 2 production rate and lower H 2 recovery) of the PSA over time.
In preferred embodiments H 2 PSA beds contain a layer (preferably a first or only layer) of adsorbent that can tolerate the various impurities found in gasifier syngas, particularly >0.2% H 2 S.
We have conducted experimental work that indicates that a preferred PSA treating H 2 S-containing syngas should have a first layer or only layer composed of either silica gel of high purity and low surface area, titania, or a polymeric adsorbent. Whereas the resins described for use in U.S. Pat. No. 5,797,979 are chemically reactive with H 2 S, resins of the current invention consist of crosslinked polymers, typically polystyrene crosslinked with divinylbenzene. So-called “hypercrosslinked” resins undergo additional crosslinking resulting in a more uniform pore size distribution and improved sorption properties. The current resins contain no charge moieties or reactive functional groups. In fact, these polymeric resins are generally considered to be chemically inert and, unlike the resins of '979, undergo no chemical reaction with adsorbed H 2 S. Useful resins for the current invention include but are not limited to Amberlite XAD4, XAD7, and XAD16 supplied by Rohm and Haas, Dowex Optipore V493 and V503 from Dow Chemical, and MN-200 resin supplied by Purolite, Inc.
FIG. 4 gives a block diagram of a first system to produce pure H 2 from a high H 2 S containing gas stream. A carbonaceous feed stock containing sulfur species (e.g., coal, petcoke, biomass, sour liquid oils or tars) is gasified in steam and oxygen in a gasifier. The hot effluent gases containing predominantly CO, H 2 , and CO 2 are quenched and/or cooled and energy is recovered. They are then fed to a water gas shift reactor where CO and water are reacted to CO 2 and H 2 . The effluent gas containing predominantly H 2 and CO 2 with relatively low levels of CO, H 2 S, CH 4 , inerts (N 2 , Ar), and other contaminants (e.g., Hg, As, NH 3 , HCl, etc) is then cooled to 30-70° C., washed with water to remove soluble components, and passed to the sour PSA unit.
The feed gas containing at least 0.2 vol % H 2 S is directed into the Sour H 2 PSA unit which contains a first layer of polymeric resin, titania or high purity silica gel or mixtures thereof. H 2 S is adsorbed in this layer, and an H 2 S-free synthesis gas is passed to subsequent layers of alumina, activated carbon, and/or molecular sieves in the Sour H 2 PSA to produce 95% or higher hydrogen product. In customary practice, to purify H 2 streams with significant levels of hydrocarbons, the PSA beds are usually layered. Generally an alumina layer is used at the feed end of the bed to remove heavy hydrocarbons. The feed gas then passes through a layer of silica gel for intermediate hydrocarbon removal (C 4 and C 5 ). A carbon layer is used to remove CO 2 and CH 4 and a zeolite layer is used to remove N 2 , Ar, and CO. The data presented herein shows alumina and activated carbon cannot be used with H 2 S containing streams with levels at 1 vol %. However, since a supplementary first layer of polymeric resin, titania, or high purity silica gel adsorbent will adequately remove the H 2 S, these adsorbents can be used in subsequent PSA layers without risk.
The Sour H 2 PSA could preferably contain anywhere from 4 to 16 beds. The process steps utilized in the illustrative Sour H 2 PSA would be those practiced for conventional H 2 PSA's—feed, pressure equalizations, provide purge, blowdown, receive purge, and repressurization. Feed pressure could range from 50 to 1000 psig (345−6900 kPa) and the purge step would be carried out at 5 to 30 psig (35−207 kPa). Feed temperature could range from 0 to 60° C. Adsorbent particle size could range from 1 mm to 5 mm.
FIG. 6 illustrates an alternative approach where the adsorbents described herein as the first adsorbent layer to be contacted with the feed gas could be present as guard bed in front of the H 2 PSA. The main advantages of using a guard bed are 1) a concentrated H 2 S containing stream can be reclaimed from the guard bed, 2) in the event of adsorbent fouling, simply the guard bed needs to be replaced, 3) regeneration mode of the guard bed can be different from that of the H 2 PSA, and 4) the guard bed can be optimized (e.g., by adding additional adsorbent layers) to remove other undesirable species possibly present in the feed gas including metal carbonyls, aromatics, heavy hydrocarbons, other sulfur containing species etc.
The guard bed removes essentially all of the H 2 S in the feed gas. In this way, the PSA vent gas from the H 2 PSA (regeneration effluent) is sulfur-free and can be burned, converted and treated without special sulfur removal technology. In addition, the waste gas from the guard bed can be obtained in concentrated form. Regeneration of the guard bed could use waste gas from the PSA or could use waste N 2 from the air separation plant.
The feed gas containing at least 0.2 vol % H 2 S is directed into the guard bed. The guard bed contains polymeric resin, titania or high purity silica gel or mixtures thereof. H 2 S is adsorbed in the guard bed and an H 2 S-free synthesis gas is directed into a typical H 2 PSA. Product gas consisting of 95% or higher hydrogen is produced for the H 2 PSA.
This illustrative H 2 PSA could contain anywhere from 4 to 16 beds. The adsorbents inside the H 2 PSA vessels could include alumina, activated carbon, silica gel and zeolites. Generally an alumina layer is used to remove heavy hydrocarbons passing through the silica gel layer, a carbon layer is used to remove CO 2 and CH 4 and a zeolite layer is used to remove N 2 , Ar, and CO. The data presented herein shows alumina and activated carbon can not be used with H 2 S containing streams with levels at 1 vol %. However, since the guard bed adequately removes the H 2 S, these adsorbents can be used in the main H 2 PSA without risk.
The process steps utilized in the H 2 PSA would be those practiced for conventional H2PSA's—feed, pressure equilizations, provide purge, blowdown, receive purge, and repressurization. Feed pressure could range from 50 to 1000 psig (345−6900 kPa) and the purge step would be carried out at 5 to 30 psig (35−207 kPa). Feed temperature could range from 0 to 60° C. Adsorbent particle size could range from 1 mm to 5 mm.
The guard bed could suitably consist of 2-4 beds. If the beds are run in a PSA mode the various cycle steps that could be employed include feed, pressure equalization, blowdown, purge and repressurization. Purge gas can come from one of the guard beds or, preferably, from the H 2 PSA vent gas. Repressurization gas can be from the sour feed gas, one of the guard bed product gas flows or from some of the H 2 PSA product gas. The PSA guard bed would represent the lowest capital cost guard bed system. However, it is likely that all the waste gas from the main PSA would be required to clean the guard bed. That would result in all the waste gas from the system containing H 2 S.
If the guard bed were run in VSA (vacuum swing adsorption) mode, less regeneration gas would be required. In this way, two waste streams could be produced from the system, one waste gas from the guard bed which contains H 2 S and the other waste stream from the PSA which does not contain H 2 S. The concentrated H 2 S waste stream could be treated with a different technology (e.g. S collection via Claus reaction) than a more dilute H 2 S containing stream. The VSA cycle steps could include feed, pressure equalization, blowdown, evacuation, purge and repressurization. The vacuum level employed could be 0.1 to 0.7 bar absolute.
If the guard bed was run in TSA mode, regeneration gas could be supplied by waste nitrogen from the cryogenic oxygen system or could be supplied by the H 2 PSA vent gas. In this way a H 2 S concentrated reject stream could be generated by the TSA. The regeneration temperature could vary from 50 to 200° C. Typical process steps could be feed, pressure equalization, blowdown, heating, cooling and repressurization. The regeneration temperature could be reached using waste heat in the synthesis gas generation process.
There could also be integration steps between the ASU, guard bed and the H 2 PSA. For example, gas released during pressure reduction steps in the guard bed could be sent to the H 2 PSA to improve the overall H 2 recovery. High pressure waste N 2 from the oxygen production plant could be used as a displacement gas in the H 2 PSA to improve the overall H 2 recovery. Still more preferably, the high pressure waste N 2 could be used as displacement gas in the guard bed units, again to improve H 2 recovery of the overall process.
Another aspect of the guard bed is that the time on stream for the guard bed can be longer than the time on stream for the H 2 PSA. For the H 2 PSA the feed time can range from 0.5 to 5 minutes, while for the guard bed, the feed time can vary from 10 to 60 minutes. The regeneration interval can be substantially longer for the guard bed than for the H 2 PSA even where both are regenerated by PSA because of the high H 25 capacity of the guard bed. However, the guard bed may instead be regenerated by TSA.
As noted above, the concept of a guard bed prior to the H 2 PSA has been previously described. In FIG. 2 of U.S. Pat. No. 4,696,680 a guard bed for CO 2 and H 2 S removal from synthesis gas is described. However, there the adsorbents suggested were activated carbon and zeolites. Such adsorbents do not satisfy the requirement herein for low sulfur deposition or low loss of capacity for CO 2 upon sulfur loading provided herein by adsorbents such as polymeric resins, high purity silica gel and titania. Further, the guard bed in the current invention is intended for H 2 S removal without substantial removal of CO 2 . Owing to the H 2 S over CO 2 selectivity of the suggested adsorbents, guard bed sizes could be much smaller if H 2 S removal only is desired. In envisioned practice current invention, the bulk of CO 2 enters into the H 2 PSA in contrast to the teachings of '680.
Incorporation of the sour H 2 PSA concept with gasifier-based power production yields a number of advantages. An overall process schematic is illustrated in FIG. 7 . A carbonaceous feed stock containing sulfur species (e.g., coal, petcoke, biomass, sour liquid oils or tars) is gasified in steam and oxygen in a gasifier. The hot effluent gases containing predominantly CO, H 2 , and CO 2 are quenched and/or cooled and energy is recovered. They are then fed to a water gas shift reactor where CO and water are reacted to CO 2 and H 2 . The effluent gas containing predominantly H 2 and CO 2 with relatively low levels of CO, H 2 S, CH 4 , inerts (N 2 , Ar), and other contaminants (e.g., Hg, As, NH 3 , HCl, etc) is then cooled to 30-70° C. and passed to the sour PSA unit.
The goal of this sour PSA unit is to remove effectively 1) essentially all of the H 2 S and other contaminants (>99% removal) and 2) most (e.g. 90%) of the carbon species from the syngas. The decarbonized product gas from the PSA is then combined with a suitable diluent (e.g., N 2 from the ASU) and combusted with air in a gas turbine for power production. The flue gas from the turbine combuster is predominantly nitrogen and water, with much lower levels of CO 2 than if the carbonaceous feed stock or the sour syngas was directly combusted. The low pressure waste gas from the sour PSA unit is enriched in CO 2 , H 2 S, and the other contaminants. It is processed further to produce a compressed CO 2 -rich, H 2 S free stream that can be sequestered or vented to the atmosphere. An additional sulfur-rich byproduct stream will be created in this processing that will capture the H 2 S and other contaminants (e.g., sulfur via a Claus plant or sulfuric acid via US 2007/0178035).
A conventional H 2 -PSA unit would not work well in this context. Conventional PSA units typically utilize a layer of carbon followed by a layer of zeolite in each adsorber bed. Carbon is used to remove CO 2 , H 2 O, and some CH 4 , while the zeolite layer removes CH 4 , CO, Ar and N 2 . Other options utilize a layer of alumina at the bottom of the bed. Our experiments have shown that the sour syngas reduces the capacity of the carbon and alumina adsorbent, thus beds packed with these materials at the feed end would slowly lose capacity to remove CO 2 and H 2 S from the feed gas. These impurities would move to the zeolite layer where they are adsorbed even more strongly—to the point where they do not effectively desorb during regeneration. The effective capacity of the adsorption bed would be severely reduced and process performance would deteriorate.
Conventional PSA units are generally configured with the zeolite layer in order to remove CH 4 , CO and the inert gases from the hydrogen product. In power generation though, there is no need to remove the inerts, as N 2 is added to dilute the hydrogen product once it leaves the sour PSA. There is also little reason to remove the CO and CH 4 , as they generally account for a relatively small amount of carbon in the sour syngas. Using a conventional PSA unit with a zeolite layer for this particular application would yield high purity hydrogen product at relatively low H 2 recovery. This embodiment of the PSA process of this invention overcomes this limitation and yields much higher H 2 recovery.
In all of the above cases, the enriched H 2 from the sour PSA can be fed to a gas turbine for combustion and power production. It will first be diluted with N 2 (from the ASU) or steam to limit the gas temperature in the turbine to acceptable levels. It is clearly not important to keep inert gases (N 2 , Ar) from the PSA product gas. This leads to a second way for improving H2 recovery from the sour PSA system—by purging or pressurizing the PSA beds with N 2 rather than H 2 . The next example describes simulations the PSA beds purged with N 2 rather than the typical H 2 product gas.
We have conducted some simulations of performance of the Sour H 2 PSA option and the Guard bed/H 2 PSA approach which are described below.
Example 1
The stability of various adsorbents was tested upon exposure to H 2 S containing synthesis gas. The adsorbents tested included two activated carbons (Calgon 12×300LC, coconut-based and Calgon 4×10 BPL, coal-based), an activated alumina (Alcan 8×14 AA300), high purity silica gel (Grace Grade-40 99.7% SiO 2 ), a low purity silica gel (Engelhard Sorbead Plus, 99.0% SiO 2 ) a polymeric resin (Dowex Optipore V-493) and a titania (Hombikat K03/C6). Packed beds were filled with 20-50 g of the above samples and exposed to approximately 350 cc/min gas flow at 400 psig (2760 kPa) and 20° C. The gas consisted of a flow of 1% H 2 S, 8% CO, 37% CO 2 , and balance H 2 . Seven additional beds were packed with the same adsorbents and were exposed to the same feed gas, although saturated with water at room temperature. The beds were held at ambient temperature during the experiments.
Adsorbent samples were removed from the beds at various time intervals to evaluate the adsorbents chemical composition and adsorption properties. Before sampling, all beds were purged with 100 cc/min of N 2 at 400 psig for 24 hours. All samples (2-5 g) were taken from the top of the beds (feed end). Analyses were conducted on fresh adsorbent samples as well as the exposed samples. Chemical compositions of the samples were determined by X-ray fluorescence analysis. A TGA unit was used to determine the amount of volatiles desorbed on heating to 200° C. (100° C. for resin) in N 2 . This regenerated sample was then cooled to 40 C and exposed to 1 atm of CO 2 . The final steady weight yielded a measure of the CO 2 adsorption capacity. Conventional low temperature N 2 adsorption techniques were used to quantify the adsorbent surface area and provide details on the pore volume of the samples (conducted after an initial regeneration under vacuum at 200° C.).
FIG. 1 shows a plot of the sulfur content of the various adsorbents upon exposure to a dry stream as a function of treatment time. The results clearly show that an increase in sulfur loading is detected as a function of exposure time for all the adsorbents tested. However, the high purity silica gel, and titania are the most resistant showing lower levels of rate of accumulation of sulfur than the lower purity silica gel or the activated carbon or activated alumina. These results would suggest that using an initial adsorbent layer of lower purity silica gel, activated carbon or activated alumina in a PSA system would result in a rapid decay in performance over time.
FIG. 2 shows a similar plot to that in FIG. 1 except this time the feed gas stream is wet (saturated with water at feed conditions). In the wet feed stream, the activated carbons still show rapid increase in sulfur content. In the wet feed stream the activated alumina and the Sorbead Plus (for which the 0 day and 7 day figures coincide with those for the activated alumina) show a lower rate of sulfur deposition. Nonetheless, even in the wet feed gas streams, the titania and the high purity silica gel show the lowest rate of sulfur deposition.
FIG. 3 shows the effect of sulfur loading on the resultant CO 2 capacity of the adsorbent. FIG. 3 also contains results of testing of a low surface area, high purity silica gel (99.7% SiO 2 ), Grace Grade 59. While sulfur loading of the adsorbent is an undesired effect, the important aspect of this sulfur loading is its effect on the adsorption capacity of the material. Clearly, the most robust surfaces with respect to sulfur loading are the high purity silica gel, titania and polymeric resin. The interesting aspect of FIG. 3 is that the effect of sulfur loading vs. reduction in CO 2 capacity is different for different adsorbents, as indicated by the slopes of the graphs. At a sulfur loading of 2 wt %, the polymeric resin retains 95% of its original CO 2 capacity while the alumina sample only retains 80% of its original CO 2 capacity at that sulfur loading. Both activated carbon samples show a more pronounced effect of sulfur loading on CO 2 capacity than the polymeric resin.
FIG. 10 further illustrates deleterious effects of H 2 S exposure on adsorbents discussed in commonly referred to in the prior art. After 30 days exposure to H 2 S at ambient conditions, the CO 2 capacity of BPL carbon decreases by 64%. OLC Carbon is even more adversely affected, with its CO 2 capacity decreasing by 80%. Alumina too decreases in capacity by 56% after 30 days of H 2 S exposure. Both the high purity silica gel and the polymeric resin show remarkable CO 2 capacity retention after H2S exposure, with the resin only losing 9% capacity, and the high purity silica gel remaining essentially unchanged.
Example 2
To better understand the effect of surface chemistry on the reaction of adsorbents with H 2 S, the zero point of charge (zpc) of the various adsorbents was tested. The zpc of a material is the pH at which the surface of the material carries no net electric charge. The zero point of charge for the various materials was determined by placing 20 grams of adsorbent in 100 ml of water and testing the pH after 24 hours. The pH of the initial solution was 7.2 and N 2 was bubbled through the solution during the 24 hour hold period. Table 1 below shows various properties of the adsorbents tested including BET surface area, zpc, the sulfur deposition rate determined from FIG. 1 up to 7 days of exposure (slope of FIG. 1 from linear regression best fit) and the percentage loss in CO 2 capacity as a function of sulfur loading derived from FIG. 3 (slope of FIG. 3 from linear regression up to seven days S accumulation). This value then corresponds to the percentage of CO 2 capacity lost for each wt % loading of sulfur in that period. Clearly, the lower value of this slope, the less affected the adsorbent is by sulfur loading.
TABLE 1
(% capacity loss/
(m 2 /g)
(change in
% S)
BET
wt % S/day)
CO2 capacity
surface
(pH units)
S deposition
reduction/S
Adsorbent
area
zpc
rate
loading
BPL
1100
9.5
0.23%/day
9.47
OLC
1200
9.2
0.15%/day
9.10
AA-300
325
9.9
0.05%/day
31.43
Grade 40
750
5.6
0.0014%/day
1.18
Grade 59
300
5.8
0.0013%/day
1.54
(at 60 deg C.)
Optipore
1100
7.2
0.078%/day
1.79
Sorbead Plus
700
6.3
0.06%/day
2.38
Hombikat
100
7.8
0.0003%/day
0.80
titania
It can be seen that whilst the best of the prior art materials (Sorbead Plus) has a sulfur deposition rate of 0.06%/day, the materials according to the first aspect of the invention have a deposition rate of no more than 0.0014%/day. Also, the rate of capacity loss for Sorbead Plus is 2.38% whereas that for the materials used in the first aspect of the invention is not more than 1.54%.
Example 3
Experiments were carried out to determine the effect of adsorption temperature on sulfur deposition as well as the effect of silica gel type on sulfur deposition. The experiments were carried out as those described in Example 1 with Grace Grade 40 silica gel and Engelhard Sorbead Plus silica gel at 20 and 60° C. feed temperatures. The results of that testing are shown in FIG. 5 . The results clearly show that 1) the type of silica gel impacts the rate of sulfur deposition and 2) the higher the feed temperature, the higher the sulfur deposition rate. These data suggest that 1) low feed temperatures to the PSA are desired and 2) high purity silica gel (greater than 99%) is more robust than lower purity silica gel, having not only the lower loss of capacity with a given sulfur loading demonstrated in FIG. 3 , but also a lower sulfur loading in a given period of use.
Example 4
Performance of a Sour H 2 PSA unit containing high purity silica gel, carbon, and 5A zeolite in a range of volume ratios was simulated using a proprietary computer program. Feed gas contained approximately 54% hydrogen, 42% carbon dioxide, 1.5% hydrogen sulfide, 0.03% carbon monoxide, and trace amounts of argon, nitrogen, and methane. A 10-bed PSA cycle utilizing four pressure equalization steps, interbed purge, and product repressurization was simulated at a feed pressure of approximately 32 atm. Carbon monoxide in the product was specified at 5 ppm and interbed purge amount was optimized. Results are shown in Table 2.
TABLE 2
Adsorbent Ratio
H2S (ppm)
CO2
H2
(silica/carbon/5A
at carbon
(ppm) at
Recovery
Relative
zeolite)
layer
5A layer
%
Productivity
1.3/1.4/1
119
3488
92.0
1.00
1.8/2.4/1
104
104
91.7
0.99
2/2.2/1
20
99
91.5
1.00
2.2/2/1
6
93
91.3
1.00
1.8/1.5/1
7
532
91.7
1.01
The silica gel layer is capable of limiting the H 2 S level at the carbon layer to levels that are tolerable (<1000 ppm). High purity H 2 can be produced at high level of recovery with the adsorbent layers described in the current invention.
Example 5
The performance of a 4-bed “guard” PSA system containing silica gel for the removal of hydrogen sulfide was simulated using a proprietary computer program. Feed gas contained approximately 54% hydrogen, 42% carbon dioxide, 1.5% hydrogen sulfide, 0.03% carbon monoxide, and trace amounts of argon, nitrogen, and methane. A cycle utilizing two pressure equalization steps, product repressurization, and a purge of waste gas from an H 2 PSA was simulated at a feed pressure of approximately 32 atm. Purge amount was optimized, and performance was predicted for hydrogen sulfide in the product specified at 5 ppm and 100 ppm. Results are shown in Table 3.
TABLE 3
H2
H2S
CO2
Recovery
(ppm) in
(ppm) in
% from
Relative
product
product
feed
Productivity
5
16
91.7
1.00
100
21
93.0
1.13
A simple Guard Bed PSA system containing high purity silica gel is capable of efficiently reducing the H 2 S in the syngas to levels that can be tolerated by a conventional H 2 PSA system (<1000 ppm).
Example 6
Performance of a PSA unit containing carbon and 5A zeolite in a range of volume ratios was simulated using a proprietary computer program. Feed gas composition was equivalent to the product stream from Example 5 (5 ppm case), such that an integrated PSA system was simulated. A 10-bed PSA cycle utilizing four pressure equalization steps, interbed purge, and product repressurization was simulated at a feed pressure of approximately 32 atm. Carbon monoxide in the product was specified at 5 ppm and interbed purge amount was optimized. Results are shown in Table 4.
TABLE 4
Adsorbent
Ratio
CO2
H2
(carbon/5A
(ppm) at
Recovery
Relative
zeolite)
5A layer
%
Productivity
1.5/1
12
86.8
1.00
1.14/1
105
87.3
1.03
This indicates that overall recovery for the combined guard bed PSA+H2PSA process will be 0.917*0.873=80%.
Example 7
Computational simulation results are provided in the following examples to illustrate the performance of the sour PSA process for this application.
In all of these cases the sour PSA process was designed to reject 90% of the carbon species (CO, CO 2 , CH 4 ) in the feed gas to yield a decarbonized, hydrogen-rich product gas. The feed gas was assumed to be cooled, shifted syngas from a conventional coal gasifier and consisted of 49.32% H 2 , 44.70% CO 2 , 3.47% CO, 1.36% H 2 S, 0.72% Ar, 0.42% N 2 , and 0.01% CH 4 . It was assumed to be available at 100° F. (38° C.), 30 atm. The PSA process used 10 packed beds, each undergoing the steps illustrated in Table 4 (two beds on feed at a time, four pressure equalizations). Individual step time (as illustrated in Table 4) was 30 seconds, so each bed completed a full cycle in 600 seconds. The low pressure blowdown and purge steps vented to a tank maintained at a pressure of 1.7 atm.
Simulations were conducted by solving the heat, momentum, and mass balance equations for each step of the process, and repeating the process for additional cycles until the system attained cyclic steady state conditions (defined as the point where time-dependent temperature, composition, and pressure variables for two consecutive cycles are identical). Process performance was characterized by evaluating the hydrogen recovery (moles of hydrogen in the product gas divided by moles of hydrogen in the feed gas) and the feed loading (total lb mole of feed gas processed per hour divided by the total bed volume).
In the first set of simulations, bed loadings of 17′ (5.2 m) of silica gel followed by 13′ (4 m) of activated carbon were assumed. A series of simulations were conducted with different amounts of purge gas. The amount of purge gas used is referenced by a purge parameter evaluated as the change in the ‘providing bed’ pressure during the ‘provide purge’ step divided by the sum of the change in ‘providing bed’ pressure during the ‘provide purge’ and ‘blowdown’ steps (in essence, the amount of gas used to purge the beds divided by the maximum amount available (total amount of purge plus blowdown gas)). These results are plotted in FIG. 8 .
The high purity silica gel layer was used to limit the H 2 S level to the carbon layer to less than 300 ppm. This H 2 S level is acceptable for continuous operation of activated carbon in a PSA unit.
The amount of feed gas in the simulations was manipulated in each run to yield 90±1% carbon rejection to the waste gas. Surprisingly high hydrogen recoveries, greater than 92% and approaching 96% for the lowest purge case, are predicted from the simulations. They are beyond the level normally associated with conventional H 2 —PSA technology (typical recovery<90%). The reasons for this improvement are 1) elimination of the ineffective zeolite layer and 2) operation of the PSA so significant Ar, N 2 , CO, CH 4 , and CO 2 slip to the product.
Example 8
In the next set of simulations the adsorption columns were considered packed with 30 ft (9.2 m) of high purity silica gel. In this case, the silica gel removes all of the undesirable components of the sour syngas. Identical conditions as above were assumed, and carbon recovery of 90±1% was maintained.
The H 2 recovery and feed productivity are plotted in FIG. 8 . For a given purge parameter, the PSA process with silica gel-only yields slightly higher H 2 recovery (up to ½ pt) with a 5-7% lower feed productivity compared to the process of Example 7.
An advantage of this approach is elimination of all adsorbents that are potentially sensitive to high H 2 S exposure (carbon, zeolite). This process would be much easier to operate than one based on mixed layer beds as one does not need to worry about limiting the H 2 S exposure to the second layer of adsorbent. It will be beneficial to adopt this strategy when the potential for adsorbent degradation are severe, e.g. with first time units or processes with varying feed H 2 S levels or flow rates.
Partial adsorbent replacement is also much simpler with an all silica gel process. Adsorbent in the feed section of the adsorber is more likely to need periodic replacement as it is contacted with all components of the sour feed gas, whereas the product end bed sees a more or less typical syngas composition. Since the entire bed is silica gel, provisions may be made within the vessels to permit removal of a bottom fraction of adsorbent (e.g., the lowest 5 ft (1.5 m) of the bed). Silica gel in upper portions of the bed would fall by gravity to lower layers as the bottom fraction is removed. Fresh silica gel can then be added to the top of the beds to complete the partial adsorbent exchange. This approach is not feasible in a bed containing multiple layers of adsorbent.
Example 9
In this set of simulations bed loadings of 1) 17′ (5.2 m) high purity silica gel and 13′ (4 m) carbon and 2) 30′ (9.2 m) high purity silica gel were used. The results are plotted in FIG. 9 . Process parameters were kept the same as in the previous simulations, and 90% carbon rejection was maintained. N 2 was used to purge the adsorber beds rather than some of the product gas.
Using an N 2 purge introduces higher levels of N 2 in the H 2 product—the H 2 level drops from 88-89% to 81-84%, and the inert gas content (Ar+N 2 ) increases from 2 to 8-10%. Even so, further dilution of the H 2 product would be required before introduction to the turbine (typically H 2 is limited to 50%), so this product gas composition from the PSA is acceptable. The big advantage of using the N 2 purge is illustrated in FIG. 9 —much higher feed loadings are achieved (at high H 2 recovery) than obtained for the ‘product gas purge’ processes. Smaller, lower cost adsorber vessels are then possible for a given feed gas flow.
In this specification, unless expressly otherwise indicated, the word ‘or’ is used in the sense of an operator that returns a true value when either or both of the stated conditions is met, as opposed to the operator ‘exclusive or’ which requires that only one of the conditions is met. The word ‘comprising’ is used in the sense of ‘including’ rather than in to mean ‘consisting of’. All prior teachings acknowledged above are hereby incorporated by reference. No acknowledgement of any prior published document herein should be taken to be an admission or representation that the teaching thereof was common general knowledge in Australia or elsewhere at the date hereof. In so far as they are not incompatible, preferred features of the invention as described above may be used in any combination. | Hydrogen sulfide is removed from a hydrogen rich gas stream using adsorbents having a low loss of carbon dioxide adsorption capacity upon sulfur loading including high purity silica gels, titania or highly cross-linked, non-chemically reactive resins. The adsorbents may be used to adsorb both carbon dioxide and hydrogen sulfide, or may be used as a guard bed upstream of a separate carbon dioxide adsorbent. | 8 |
CROSS REFERENCE TO RELATED APPLICATIONS
This application claims priority based on Provisional application Ser. No. 60/015,172 filed Apr. 10, 1996.
BACKGROUND OF THE INVENTION
1. Field of the Invention
This application relates to plumbing apparatus, and more particularly, to a plumbing connector system that is useful for connecting in-wall potable water supply lines to plumbing fixtures and appliances.
2. Description of Related Art
Cross linked polyethylene (PEX) tubing and various connector fittings have previously been used by the building industry as an alternate way to heat homes and to keep driveways and steps clear of snow and ice. More recently, builders have begun to use PEX tubing for the potable water systems in homes, replacing the use of copper tubing. The valves presently available for use with PEX potable water tubing are typically angle stops that are stubbed in through the wall.
A connection device said to be useful for outlet fittings in an installation for conveying water for industrial or domestic use is disclosed in EP 0 085 329 B1. This publication discloses flexible pipe lines laid in dummy pipes in a building, having a connection piece secured under the wall surface in a connection box. The flexible pipe lines are said to be made of plastics, preferably PEX, and means are disclosed for joining the pipe lines to the connection piece. Plumbing connector systems utilizing various connector fittings for attaching water service boxes to chlorinated polyvinyl chloride (CPVC) water supply lines have also been disclosed. Such systems are believed to have been marketed by Oatey and IPS.
SUMMARY OF THE INVENTION
The invention disclosed herein is a plumbing connector system comprising a recessed, in-wall water service box, at least one valve having an inlet extension connected to the water service box, and connector fittings particularly adapted for use in connecting in-wall potable water supply lines made of PEX to the valve inlet extension. The valve outlet can comprise any conventional means useful for connecting a valve to appliances and fixtures such as washing machines, ice makers, sinks, and the like, using flexible hose or tubing with conventional fittings. Water service boxes used in such applications typically comprise one or more valves and optionally, depending upon the use, single or multiple waste drains.
According to one preferred embodiment of the invention, the valve inlet extension of the subject connector system has an externally threaded male end that threadedly engages the valve inlet, a hexagonal flange section for use in tightening and untightening the valve inlet extension relative to the valve inlet; an externally threaded section for use in securing the valve inlet extension and valve to the water service box, and a barbed end for attachment to a PEX water supply line. The barbed end of the valve inlet extension can be integrally formed at the end of the extension that is opposite the inlet valve, or can be separately made as an adapter and then attached to a male iron pipe (MIP) valve extension.
According to another preferred embodiment of the invention, the barbed end of the valve inlet extension is attached to the free end of a PEX water supply line using a metal crimp ring.
According to another preferred embodiment of the invention, the barbed end of the valve inlet extension is attached to the free end of a PEX water supply line using a PEX crimp ring.
BRIEF DESCRIPTION OF THE DRAWINGS
The apparatus of the invention is further described and explained in relation to the following figures of the drawings wherein:
FIG. 1 is a simplified front elevation view of a water service box having two water inlet valves, each being connected to a PEX water supply line;
FIG. 2 is a side elevation view of the water service box of FIG. I with the connection to the PEX water supply line below the box exploded to better illustrate its parts;
FIG. 3 is an exploded side elevation view depicting a different connector fitting for attaching the valve inlet extension to a PEX water supply line;
FIG. 4 is an exploded side elevation view depicting a valve with a male iron pipe extension, a barbed adapter and a connector fitting for attaching the male iron pipe extension to a PEX water supply line;
FIG. 5 is a simplified front elevation view of a different style water service box having a single valve with a different style outlet and an inlet valve extension connected to a PEX water supply line; and
FIG. 6 is a side elevation view of the water service box of FIG. 5 with the connection to the PEX water supply line below the box exploded to better illustrate its parts.
DESCRIPTION OF THE PREFERRED EMBODIMENTS
Referring to FIGS. 1 and 2, one preferred connector system 10 of the invention preferably comprises a recessed, in-wall water service box 12, valves 14, 16 having threadedly engaged valve inlet extensions 18, 20 connected to water service box 12, and connector fittings as described below particularly adapted for use in connecting in-wall potable water supply lines 24, 26 made of PEX to the barbed ends of valve inlet extensions 18, 20. Water service boxes useful for practicing the invention are typically made of plastic or metal and are commercially available in a variety of different configurations depending, for example, on the intended application, the number of valves needed, and whether or not a waste water drain is also needed. Water service box 12 as shown is a molded plastic box having top, bottom, back and side walls, and an overall depth such that it can be recessed in a wall and attached to studs for support. Nails, screws or other fasteners can be inserted through ears 28; alternatively, where the stud spacing is such that ears 28 cannot be directly attached to a stud, brackets 30 are provided on each side of box 12 through which conventional extension pieces (not shown) can be inserted for attachment to stud(s) spaced away from the sides of box 12. Knockouts 32 are desirably provided in the bottom of box 12, and boxes can also be made having knockouts in the sides, back or top walls if desired. Many water service boxes are made with concentrically disposed knockouts of different diameters to permit removal of one knockout to facilitate attachment of a valve and a different knockout to facilitate insertion or attachment of a waste drain line. Although not shown in the drawings, faceplates that snap on or otherwise attach to the front of water service boxes are well known.
Valves 14, 16 are depicted as quarter turn ball valves, but those of ordinary skill in the art will appreciate upon reading this disclosure that other types of valves can also be used within the scope of the invention provided they are constructed in such manner as to permit use within the confines of water service box 12. Brass is a preferred material for use in fabricating valves 14, 16 and valve inlet extensions 18, 20 for use in the present invention, although other metal and plastic materials can also be used. Other metals useful for particular applications as valve inlet extensions 18, 20 include without limitation stainless steel, steel aluminum, and copper. Other plastics potentially useful as valve inlet extensions 18, 20 together with plastic valves include without limitation filled polyethylene, filled polypropylene, and polysulfone. Viewed externally, each valve 14, 16 typically comprises an outlet port 34, handle mechanism 36 for actuating the valve, and inlet port 38 and valve inlet extension 18 that is preferably threaded into inlet port 38. Alternatively, depending upon the materials used to make valve 14, 16 and valve inlet extensions 18, 20, the extension can be attached to the valve by gluing, soldering, or ultra-sonic welding.
Valve inlet extension 18 preferably comprises a centrally disposed, longitudinal bore 40, an external hexagonal flange section 42 used to tighten male threaded end 44 into water-tight engagement with female threads 46 inside valve inlet port 38, an externally threaded section 48 below hexagonal flange 42, a lower flange 50 comprising an annular shoulder 52, and a barbed end section 54 below annular shoulder 52 of lower flange 50. The transverse dimension of hexagonal flange 42 is desirably great enough large enough to support valve 14 above a coaxially aligned opening through a wall, here the bottom wall, of water service box 12, while the outside diameter of externally threaded section 48 is desirably slightly less than the diameter of the opening to permit attachment of a threaded locknut 56 that will releasably secure valve inlet extension 18 to water service box 12. Although use of a threaded locknut 56 is disclosed herein for releasably securing valve inlet extension 18 to water service box 12, it will be apparent that other similarly effective means such as push-nuts, clips, E-rings, and the like, can also be used within the scope of the invention. Alternatively, valve 14 and valve inlet extension 18 can be permanently attached to a water service box by means such as gluing if desired. Annular shoulder 52 is desirably provided adjacent to barbed end section 54 to limit insertion of the barbed end into free end 58 of PEX water supply line 24. Outlet port 34 as shown in FIGS. 1 and 2 is a conventional, internally threaded female valve outlet port suitable for connection to an externally threaded male connector fitting of the type known for use with a flexible connector hose or tubing (not shown), although it will be appreciated that an outlet port having an externally threaded male connection or a rotatable, female threaded hexagonal connector 60 as shown in FIGS. 5 and 6 can also be used within the scope of the invention.
Prior to pushing free end 58 of PEX water supply line 24 over barbed end 54 of valve inlet extension 18 as shown in FIG. 1, metal ring 62 as shown in FIG. 2 having a diameter slightly greater than the outside diameter of line 24 is desirably slipped over free end 58. Once free end 58 is in place over barbed end 54, metal ring 62 is positioned around barbed end 54, and crimped into place to complete the attachment of line 24 to valve 14. This means of attachment is typically preferred for use with PEX pipe or tubing made by the so-called "Silane" method.
According to another embodiment of the invention as shown in FIG. 3, free end 64 of PEX water supply line 66 is connected to barbed end 68 of valve inlet extension 70 using a PEX ring 72. According to this embodiment, which is typically preferred for use with PEX pipe made by the so-called "Engle" method, PEX ring 72 is slipped over end 64, and a tool is used to spread the inside diameter of end 64 and ring 72 so that barbed end 68 of valve inlet extension 70 can be inserted into end 64. Once end 64 and ring 72 are in place over barbed end 68, ring 62 relaxes around barbed end 68 to hold end 64 of PEX water supply line 66 in place relative to valve 74.
According to another embodiment of the invention as shown in FIG. 4, a male iron pipe (MIP) valve inlet extension 76 is threaded into the inlet side of valve 78. This MIP nipple desirably has external threads useful for securing it to a water service box using locknut 80. Lower end 82 of extension 76 desirably has a recessed counterbore 84 into which unbarbed end 86 of barbed adapter 88 is pressed and secured by means such as soldering. It will be appreciated, of course that other means of attachment such as threads, glue, welding, and the like, can also be used depending upon the materials of construction. Free end 90 of PEX water supply line 92 can then be attached to barbed end 94 using metal ring 96 as shown or by using a PEX ring as disclosed in FIG. 3, as appropriate.
Referring to FIGS. 5 and 6, connector system 100 of the invention comprises water service box 102 having a single valve 104 releasably secured inside it by locknut 106 threadedly engaging valve inlet extension 108 as described above. A rotatable threaded nut 110 is provided on the outlet side of valve 104 for attachment to a male threaded end fitting of a flexible hose connector (not shown). Free end 112 of PEX water supply line 114 can be attached to barbed end 116 of valve inlet extension 118 using either of the methods and apparatus previously described in relation to FIGS. 2 and 3 above. Water service box 102 illustrated in this embodiment is provided with a plurality of ears 120 for use in attaching box 102 to supporting studs (not shown) within a wall.
Other alterations and modifications of the invention will likewise become apparent to those of ordinary skill in the art upon reading the present disclosure, and it is intended that the scope of the invention disclosed herein be limited only by the broadest interpretation of the appended claims to which the inventors are legally entitled. | A plumbing connector system having a recessed, in-wall water service box, at least one valve connected to the water service box, and connector fittings particularly adapted for use in connecting in-wall potable water supply lines made of Cross linked polyethylene (PEX) to appliances and fixtures such as washing machines, ice makers, sinks, and the like. A valve inlet extension having a barbed end is disclosed for use in releasably securing the valve to the water service box and for connecting the valve to the Cross linked polyethylene water supply line. | 8 |
[0001] The present invention is a non-provisional of U.S. provisional application 62/299,387filed Feb. 26, 2016, entitled Fold Down Trampoline by inventor Samuel Chen, the disclosure of which is incorporated herein by reference.
[0002] The present invention also claims priority from China application 201621475238.0 filed Dec. 30, 2016, entitled A Trampoline with Separate Automatic Detent Structure by applicant Xiamen Dmaster Health Technology Co., Ltd., now assigned to Sportspower Limited, the disclosure of which is incorporated herein by reference.
FIELD OF THE INVENTION
[0003] The present invention is in the field of folding frame trampolines.
DISCUSSION OF RELATED ART
[0004] A variety of different trampoline enclosures can fold-down. These trampoline enclosures are used for improving safety of users to help them not fall out of the trampoline jumping area. For example, in U.S. patent publication 2012/0252634 published Oct. 4, 2012 by inventor Masato Ikegami entitled Trampoline With Collapsible Enclosure Assembly, an enclosure assembly has support arches that fold-down, the disclosure of which is incorporated herein by reference. Ikegami also discloses that hinge joints can be used.
[0005] As shown in FIG. 1 , the folded-type trampoline proposed by the prior art Taiwan patent publication document TW M285374 operates the second frame rod 12 from an unfolded position to a folded position after clamping the pivot 121 of the second frame rod 12 to the pivot connection groove 111 of the corresponding first frame rod, and finally inserts the locating assembly 13 into the corresponding locating hole 122 to fix the spacing and the trampoline is unfolded. However, the trampoline bed has a strong elastic contraction force. This causes several problems. First, if not completely clamped to the corresponding pivot connection groove 111 , the pivot 121 will eject from the pivot connection groove 111 when the second frame rod 12 is operated from the unfolded position to the folded position. Second, if the force interrupts when the second frame rod 12 is operated from the unfolded position to the folded position, the elastic contraction force of the trampoline bed will clamp the first frame rod 11 and the second frame rod 12 and thus users may be clamped by the trampoline frame like a fly in a Venus fly trap like what is happened with some Consumer Product Safety Commission recalled trampolines. Finally, even if the second frame rod is operated to the folded position, the locating assembly 13 needs to be inserted into the locating hole 122 . During this process, force must be exerted to ensure the second frame rod 12 is constantly in this folded position, otherwise the second frame rod 12 will be pulled by the trampoline bed, bounce back and hurt the users, which is indeed very dangerous. As is shown in FIG. 2 and FIG. 3 , when the second frame rod 12 is operated from the unfolded position to the folded position, force needs to be exerted to ensure the second frame rod 12 is located in this folded position. Then, a locating assembly 13 is inserted into a locating hole 122 to fix the spacing, during which users face the same risk of injury.
[0006] Therefore, a variety of different trampoline frames are made to be foldable. In U.S. Pat. No. 4,452,444, issued Jun. 5, 1984, inventor Schulze, Jr., discusses a “rebound exerciser” or trampoline that is foldable, the disclosure of which is incorporated herein by reference. Schulze, Jr. describes “a hinge with a locking means that secures symmetrical sections together. The locking member have substantially U-shaped rod having two threaded ends which are adapted to be inserted through said pair of spaced-apart, aligned bores when said sections are in said second extended position; and a pair of double threaded nuts adapted to be mated with said threaded ends when said threaded ends are inserted through said pair of bores so as to releasably secure said sections in said second extended position.” Additionally, U.S. Pat. No. 7,094,181 published Aug. 22, 2006, discusses a foldable trampoline. Inventor Hall describes legs and hinges configured to provide lateral flexibility in the framework, to thereby decrease the stress imposed on the hinges, thereby increasing the life of the hinges, when the trampoline is folded. The same inventor Hall in U.S. Pat. No. 6,648,799 published Nov. 18, 2003, discusses a Foldable Trampoline in which the “pivoting means include a pair of hinges and a set of hinges. The pair of hinges are disposed on opposite ends of the frame such that a pivot axis is along a diametrical line of the circular frame, including the pair of hinges. In such a configuration, the hinges permit the frame to be moved between a substantially planar open position and a folded position.”
[0007] Also, Wang et. al. discusses in U.S. Pat. No. 6,939,270 entitled Foldable Trampoline published Sep. 6, 2005, two pairs of overlapped lug portions to have two through holes provided thereon opposite to the shaft pin, so that a safety pin may be inserted into the through holes when the frame sections are in a fully extended position. The invention entitled titled Foldable Trampoline and Conversion Kit in U.S. Pat. No. 7,862,479 by inventor Goldwitz, published Jan. 4, 2011, discusses hydraulic cylinders connecting the base frame member to the center hinge, which, “may assist in controlling the movement of the frame assembly from a collapsed state to an expanded state or vice-versa. For example, the hydraulic cylinders may substantially or completely assist in preventing the frame assembly from “snapping” shut thereby causing injury to the user when moving the frame assembly from a collapsed state to an expanded state or vice-versa.”
[0008] Instead of a snapping hinge, inventor Tacquet in U.S. Pat. No. 6,110,074 published Aug. 29, 2000, discusses, “opening the trampoline for use involves using a crank to turn the screw and doing that, the pushrods will push against the thrusts and the distance between the ends of the adjacent frame sections will be increased. The more the user turns the screw, the more the distance between the ends of the adjacent frame sections increases, and when that distance increases, it also increases the diameter of the whole frame as well as its distance from the mat. As the mat is linked to the frame by means of the springs, the length of the springs is increased and the force applied via springs increases proportionally to their length. The maximum tension of the mat is obtained when the screws have been fully turned.”
[0009] Inventor Lai in U.S. Pat. No. 7,468,020 published Dec. 23, 2008, entitled Foldable Trampoline, discusses a safety feature in the summary of invention as, “When the coupling shaft is extended into the coupling notch, and the foldable frame unit is operated to move from the folded state to the unfolded state, the securing shaft is guided along the guiding edge of the first end part of the first frame section and is subsequently received in the securing notch such that the coupling shaft and the securing shaft cooperate with the first end part of the first frame section to secure the foldable frame unit in the unfolded state.”
[0010] U.S. Pat. No. 4,824,100 entitled Opposed Rebounding Exercise Device, published Apr. 25, 1989, by inventor Hall et al. discusses a safety feature where each sleeve is slidable along a leg of a U-shaped frame and is locked in desired position by a pair of set screws and that are threaded through the sleeve and into engagement with the leg. In U.S. Pat. No. 4,415,151 entitled Collapsible Rebound Exercise Device, published Nov. 15, 1983, inventor Daniels discusses a trampoline with framework that includes a first pair of opposed hinges disposed for permitting the framework to be moved between a substantially planar open position and a folded or collapsed position, and including a lock arrangement for retaining the framework in the open, or use, position.
SUMMARY OF THE INVENTION
[0011] A trampoline of the present invention has a frame that can fold to a flat folded position from a deployed position. A trampoline with a folding frame has a frame supporting a bed tensioned by springs across the frame. The frame has horizontal frame members including a horizontal frame member formed as a frame unit. The frame unit has a first frame rod and a second frame rod. The first frame rod connects to the second frame rod. Two locating assemblies pass the joint of the first and the second frame rods and multiple support rod bases where the first and the second frame rods extend downwardly. The first frame rod extends and includes two first ends.
[0012] A retaining plate is mounted to the first frame rod. The retaining plate has a pair of plate sides. The pair of plate sides extend downwardly from the retaining plate. The retaining plate is mounted on the first ends of the first frame rod. Each retaining plate has an end face formed toward a front of the two first ends. Two clamping grooves are indented at a pair of end faces. The pair of end faces is formed on the pair of plate sides. Two pivot connection grooves extend upwardly into a pair of undersurfaces. The pair of undersurfaces are formed on the lower surface of the pair of plate sides. Two stop grooves that extend laterally from the two pivot connection grooves. Two pivots are mounted on the second frame rod and configured to engage the two stop grooves. A locating hole is formed on the second frame rod at a side of the second frame rod. The locating hole is configured to receive a locating assembly that engages the two clamping grooves.
[0013] Optionally, the trampoline with folding frame may have a retaining plate with stop blocks on the lower surface. Each stop groove has an upper groove wall and a lower groove wall is set opposite to an upper groove wall. A groove sidewall is configured between the upper groove wall and the lower groove wall. Each upper groove wall, lower groove wall and groove sidewall is load bearing and may abut the frame rods. The second frame rod also includes two auxiliary supports connected to their corresponding auxiliary support bottom edges and auxiliary support pivots. The retaining plate has plate sides that are parallel to each other. The second frame rod also includes threading slots connected to corresponding locating holes. The two locating assemblies each comprise a rod and multiple fixture blocks that protrude and extend towards the outer periphery of the rod. Each rod and its corresponding fixture block respectively respond to their respective threading slot.
[0014] Each locating assembly also includes a bumper in an arc shape. An end of each bumper is connected to a first side end of the corresponding rod. The other end of each bumper is detachably nested in a second side end of the corresponding rod. Each retaining plate may have an inverted U-shape cross-section. The support rod bases have joint pipes connected to an outer periphery of the first frame rod and the second frame rod and legs connected to the joint pipes. The joint pipes are welded to the first frame rod and the second frame rod.
[0015] Through the design of the pivot connection grooves and the stop grooves, the locating assemblies can be first inserted into the corresponding locating holes. After the pivot is clamped to the corresponding pivot connection groove, the second frame rod is operated from the unfolded position to the folded position. Then the locating assemblies are respectively inserted into the corresponding locating holes and clamping grooves. Moreover, the pivot is clamped to the corresponding stop groove to complete the unfolding action. Hence, this design can enhance the operational safety of the product.
[0016] The trampoline also includes a trampoline frame including a trampoline frame ring supported by a trampoline frame. A trampoline bed is supported across the trampoline frame. Enclosure poles are oriented in a vertical orientation when the enclosure poles are in a deployed position. One or more hinge joints connect the enclosure poles to the trampoline frame. The enclosure poles are mounted to the trampoline frame ring at the hinge joints. The enclosure poles fold inward to a horizontal position when the enclosure poles fold to a folded position. The enclosure poles may overlap each other when folding to the folded position. In this way, the entire trampoline can fold for shipping or storage including the poles and frame.
BRIEF DESCRIPTION OF THE DRAWINGS
[0017] FIG. 1 is prior art partial exploded view, illustrating the corresponding positions of a pivot connection groove, a pivot, a locating assembly and a locating hole.
[0018] FIG. 2 is a prior art partial exploded-view, indicating the corresponding positions of a locating assembly and a locating hole.
[0019] FIG. 3 is an incomplete exploded-view drawing of the prior art, illustrating the corresponding positions of a locating assembly and a locating hole.
[0020] FIG. 4 is a diagram of an embodiment of the trampoline with folding frame in the present invention, demonstrating the combination relationship between a frame unit and a trampoline bed.
[0021] FIG. 5 is an incomplete partial enlarged diagram of an embodiment of the present invention, indicating the status where the first frame rod and the second frame rod is fixed by a locating unit.
[0022] FIG. 6 is an incomplete partial exploded-view drawing of an embodiment of the present invention, illustrating the corresponding positions of a pivot connection groove, a stop groove, a pivot, a locating hole and a locating assembly.
[0023] FIG. 7 is a diagram of an embodiment of the invention, suggesting the status where the second frame rod is unfolded and the first frame rod and the second frame rod are turned over.
[0024] FIG. 8 is an incomplete partial section view of an embodiment of the present invention, suggesting the status where the second frame rod is located in this unfolded position and the locating hole and its corresponding clamping groove are staggered.
[0025] FIG. 9 is an incomplete partial section view of an embodiment of the present invention, illustrating the status where the locating hole and its corresponding clamping groove are apposed.
[0026] FIG. 10 is a diagram of the assembled trampoline in upright configuration.
[0027] FIG. 11 is a diagram of the trampoline being disassembled.
[0028] FIG. 12 is a diagram of the trampoline being disassembled.
[0029] FIG. 13 is a diagram of the enclosure pole connector.
[0030] FIG. 14 is a diagram of the folding trampoline enclosure pole.
[0031] The following call out list of elements can be a useful guide for referencing the element numbers of the drawings.
11 First frame rod 111 Pivot connection groove 12 Second frame rod 121 Pivot 122 Locating hole 13 Locating assembly 200 Frame unit 20 First frame rod 21 First end 22 Retaining plate 221 End face 222 Clamping groove 223 Undersurface 224 Pivot connection groove 225 Stop groove 226 Stop block 227 Plate side 228 Upper groove wall 229 Lower groove wall 230 Groove sidewall 30 Second frame rod 31 Second end 32 Bottom edge 33 Pivot 34 Auxiliary support 35 Stopper 36 Locating hole 37 Threading slot 40 Locating assembly 41 Rod 42 Fixture block 43 Bumper 50 Support rod base 51 Joint pipe 52 Leg 600 Trampoline bed 60 Mesh 70 Fitting 80 Separate connector X Circumferential Direction 110 Trampoline Frame 115 Trampoline Frame Ring 116 Trampoline Frame Leg 120 Trampoline Bed 130 Enclosure Pole 131 Enclosure Pole Connector 132 Trampoline Frame Hinge Joint 133 Upper Enclosure Support 134 Pin 135 Pin Receiving Opening 136 Knob 137 Spring Cover Strap
DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENT
[0084] As is indicated in FIGS. 4, 5 and 6 , an embodiment of the trampoline with folding frame in the present invention includes a frame unit 200 , and a trampoline bed 600 . The frame unit 200 includes a first frame rod 20 , a second frame rod 30 which is connected to the first frame rod 20 in a hollow ring shape, two locating assemblies 40 which can pass the joint of the first and the second frame rods 30 , multiple support rod bases 50 where the first and the second frame rods 30 extend downwardly, and multiple separate connectors 80 which are respectively equipped in the outer periphery of the first frame rod 20 and the second frame rod 30 . The first frame rod 20 extends circularly and includes two first ends 21 set opposite and two retaining plates 22 respectively mounted on the first ends 21 .
[0085] Each retaining plate 22 has an end face 221 formed in the front, two clamping grooves 222 which depress towards the end faces 221 and extend circularly, multiple undersurfaces 223 which respectively intersect with the end faces 221 and are located at the bottom, two pivot connection grooves 224 which depress towards each undersurface 223 and two stop grooves 225 where one end of each pivot connection groove 224 and away from the end face 221 extends circularly, many stop blocks 226 which are located in the corresponding undersurfaces 223 , pivot connection grooves 224 and stop groove 225 , and multiple plate sides 227 which are respectively located at both sides and correspond to the pivot connection grooves 224 and the stop grooves 225 .
[0086] Each stop groove 225 has an upper groove wall 228 corresponding to the undersurface 223 , a lower groove wall 229 set opposite to the upper groove wall 228 and a groove sidewall 230 situated between the upper groove wall 228 and the lower groove wall 229 . In the present embodiment, the cross-section of each retaining plate 22 is in an inverted U-shape, and is fixed downward to the first end 21 . However, retaining two plates to both sides of the corresponding first end 21 can achieve the same effects as well.
[0087] The second frame rod 30 extends circularly and includes: two second ends 31 set opposite, two bottom edges 32 respectively formed at the bottom of the second end 31 , two pivots 33 which are respectively connected to the bottom edges 32 and nested in the stop grooves 225 via the corresponding pivot connection grooves 224 , two auxiliary supports 34 whose two ends are respectively connected to the corresponding bottom edges 32 and pivots 33 , many stoppers 35 formed at two ends of each pivot 33 , multiple locating holes 36 which respectively depress toward the second end 31 and are located at the corresponding two sides of the pivots 33 and many threading slots 37 that are connected to the corresponding locating holes 36 . More specifically, each upper groove wall 228 , lower groove wall 229 and groove sidewall 230 can press against the pivot 33 corresponding to the spacing. The pivots 33 and the locating holes 36 are configured in a radial direction that is perpendicular to the circumferential direction X.
[0088] Each locating assembly 40 includes a rod 41 , multiple fixture blocks 42 that protrude and extend towards the outer periphery of the rod 41 , and a bumper 43 in an arc shape. Each rod 41 and its corresponding fixture block 42 respectively respond to the threading slot 37 . One end of each bumper 43 is connected to one side end of the corresponding rod 41 , while the other end of each bumper 43 is detachably nested in the other side end of the corresponding rod 41 . Specifically, the locating assembly 40 has the effect of automatically stop so that the first frame rod 20 and the second frame rod can press against and fix each other.
[0089] The support rod base 50 has many joint pipes 51 alternately equipped and connected to the outer periphery of the first and the second rods 20 and 30 and many legs 52 connected to the corresponding joint pipes 51 . It should be noted that the joint pipes 51 are welded to the first and the second frame rods 20 and 30 , and that each joint pipe 51 is equipped in the adjacent corresponding separate connector 80 . The trampoline bed 600 is hung at this frame unit 200 , and includes the mesh itself 60 , multiple fittings 70 fixed around the mesh 60 . The fittings 70 are connected to the first and the second frame rods 20 and 30 .
[0090] As is shown in FIGS. 7, 8 and 9 , to facilitate storage and transport, in this embodiment, the first frame rod 20 is generally separate from the second frame rod 30 in order to save space. When this embodiment is unfolded and used, it is first turned over to the back, the locating assembly 40 is first inserted into the corresponding locating hole 36 , and then the pivot 33 is clamped to the corresponding pivot connection groove 224 . Next, the second frame rod 30 is pressed downward from an unfolded position where the locating hole 36 and the corresponding clamping groove 222 are staggered ( FIG. 8 ) to the front of the corresponding clamping groove 222 of the locating assembly 40 . Next, the pivot 33 is moved circularly to the corresponding stop groove 225 so that the second frame rod 30 is operated to a folded position ( FIG. 9 ) where the locating hole and its corresponding clamping groove are apposed.
[0091] Specifically, when the second frame rod 30 is located in this folded position, the locating assemblies 40 are respectively inserted into the corresponding locating holes 36 and the clamping grooves 222 , and the pivots 33 are clamped to the corresponding stop grooves and is pressed against and stopped by the stop blocks 226 . When operation is conducted between the unfolded position and the folded position, the stopper 35 can press against the corresponding plate side 227 ( FIG. 6 ), thereby preventing the pivot 33 from moving perpendicularly to the circular direction when the second frame rod 20 operates between the unfolded position and the folded position.
[0092] In conclusion, the present invention provides a trampoline with folding frame that includes a frame unit. In the prior art, force needs to be applied to ensure the second frame rod is located in this folded position before the locating assemblies 40 can be inserted into the corresponding locating holes 36 . In contrast, in the present embodiment, before unfolding, the locating assemblies 40 are first inserted into the corresponding locating holes 36 , and then after the pivot 33 is clamped to the corresponding pivot connection groove 224 , the second frame rod 30 is operated from the unfolded position where the locating hole 36 and the corresponding clamping groove 222 are staggered to the folded position where the locating hole 36 and the corresponding clamping groove 222 are apposed in order to complete the unfolding action. The danger caused by exerting a force on the folded position for a long time can be avoided so as to enhance the operational safety of the device.
[0093] The trampoline also has an enclosure that folds down. The trampoline has a trampoline frame 110 which supports the trampoline bed 120 . The trampoline frame 110 has a trampoline frame ring 115 that is substantially horizontally oriented for supporting the trampoline bed 120 in a horizontal position. The trampoline frame ring 115 is supported by one or more of the trampoline frame legs 116 .
[0094] The trampoline frame ring 115 also includes trampoline frame hinge joints 132 . The hinge joints 132 allow the enclosure poles 132 fold-down after the upper enclosure support 133 has been removed. The enclosure poles fold inward at an angle normal to the trampoline frame ring 115 .
[0095] The enclosure poles 132 are hinged to the trampoline frame ring 115 at the trampoline frame hinge joints 132 . The enclosure poles 132 are independent and cross over each other when the trampoline enclosure is in stowed configuration. The enclosure poles 132 fold inward when the enclosure is in stowed configuration and fold upward to an upright position when the enclosure is in the deployed position.
[0096] The enclosure pole connectors can be formed as sockets having a slot for receiving the upper enclosure support 133 . The upper enclosure support 133 can be formed as a horizontally suspended ring made of metal, plastic or fiberglass. The upper enclosures for 133 can be formed as segments of a plurality of connected rods. The hinge joint 132 can be stabilized by a pin 134 that is inserted into a pin receiving opening 135 on the hinge joint 132 to keep the enclosure pole 130 in upright position. The pin 134 preferably passes through the enclosure poles which are formed as hollow metal tubes. The hinge joint can also have a pair of flanges that have openings for the pin receiving opening 135 . The pin 134 receiving opening 135 passes through the pair of flanges and the enclosure pole for locking them together. The pin 134 receiving opening 135 and the pin 134 can be threaded for additional tightness and security and to avoid wobble.
[0097] A knob 136 can be formed on the trampoline frame leg 116 at the junction of the trampoline frame leg 116 and the trampoline frame ring 115 . The knob 136 can be connected to a bolt that bolts or connects the trampoline frame leg to the trampoline frame ring 115 . The knob 136 is located below the level of the trampoline frame ring 115 , but can also provide the same function as the pin 134 if the knob 136 is at least partially connected to a portion of the trampoline enclosure pole.
[0098] A spring cover strap 137 can be formed as a loop that has an opening that fits over the knob 136 . The spring cover strap 137 loop ends are connected to the spring cover. The spring cover covers the springs. The spring cover can be a sheet of plastic or can have a thicker expanded foam padding. Trampoline pads can have straps that loop over the head of the knob 136 . The trampoline pads traps can be formed of fabric or cord the as rope. The trampoline pads are typically placed along a circumferential periphery of the trampoline frame ring 115 . Trampoline pads can have an elastic strap for the spring cover strap 137 that fits over the head of the knob 136 . | A trampoline includes a trampoline frame including a trampoline frame ring supported by a trampoline frame. A trampoline bed is supported across the trampoline frame. The trampoline frame is foldable. Enclosure poles are oriented in a vertical orientation when the enclosure poles are in a deployed position. One or more hinge joints connect the enclosure poles to the trampoline frame. The enclosure poles are mounted to the trampoline frame ring at the hinge joints. The enclosure poles fold inward to a horizontal position when the enclosure poles fold to a folded position. The enclosure poles may overlap each other when folding to the folded position. | 0 |
CROSS-REFERENCE TO RELATED APPLICATIONS
This application claims the benefit of U.S. Provisional Application No. 60/133,377, filed May 10, 1999.
BACKGROUND OF THE INVENTION
1. Field of the Invention
This invention relates to the field of consumer electronics, and, in particular, to screening techniques for copy-protected material.
2. Description of the Related Art
Digital recordings have the unique property that copies of the content material have the same quality as the original. As such, the need for an effective copy-protection scheme is particularly crucial for the protection of content material that is digitally recorded. A number of protection schemes have been developed (or proposed) that record the content material in an encrypted form. Other protection schemes have been developed (or proposed) that record an encrypted key that controls the playback, or rendering, of the content material. In a number of these approaches, an attempt is made to minimize the value, or worth, of an illicit copy of copy-protected material by incorporating screens, or filters, in playback or recording devices that prevent the rendering or recording of these illicit copies. Because many alternative techniques are currently available, and because many other alternative techniques are being developed, the adoption of a single protection scheme by the providers of copy-protected material and the vendors of consumer electronic devices has been, and continues to be, a daunting task.
The Secure Digital Music Initiative (SDMI) has proposed a phased approach to enhanced methods of screening for illicit copies of copy-protected material. That is, because most security systems are embodied in programming code, it is relatively easy to upgrade a security system to effect alternative security measures as these measures are developed and standardized. Such an upgrade can be accomplished by sending a replacement memory device to a user, by having the user download the new programming code from an Internet site, and so on. Initially, for example, copy-protected material will contain an indication, or mark, that it is copy-protected material, or, in some cases, a mark that indicates that the material has been tampered with. For example, a mark may indicate that the content material has been converted to a compressed format when it should not have been compressed. A compliant player will not play content material that contains such a mark but does not contain the appropriate SDMI authorization. For ease of reference, content material that does not contain the appropriate SDMI authorization for the content material is termed Non-SDMI, or NSDMI. Also, for ease of understanding, the SDMI approach is used herein as a paradigm for security systems that utilize a phased approach to protection schemes.
A conventional SDMI screening process 100 is illustrated in FIG. 1 . User material 101 is received by the process 100 , and tested to determine whether it is material that has an appropriate SDMI authorization. If so, the SDMI material is provided to the processing components of the player or recorder, labeled “SDMI Functions” 120 , in FIG. 1 . These SDMI functions 120 process the material and provide the intended output 121 associated with the device; that is, a player renders the material via acoustic devices, a recorder records the material, typically in a secure form, on another medium, such as a recordable CD, and the like.
If, at 110 , the material 101 does not contain the appropriate SDMI authorization, it is screened for a mark, at 130 . If the material 101 does not contain the aforementioned mark, it is deemed not to be copy-protected material, and, therefore, freely playable or recordable. For example, copy-protected material may be marked using a “watermark” that cannot be removed from the material without destroying, or significantly degrading, the quality of the material. If a watermark is not detected at 130 , it is likely that the user material 101 is not copy-protected. Such material may be commercial material that has been provided before the use of a watermark is adopted, or material, such as, private recordings or other recordings, that are intentionally not copy-protected. If, at 130 , a mark is not found, the material 101 is processed, at 170 , to be SDMI-compatible, for subsequent rendering or other processing, via the SDMI functions 120 . Other security tests, such as commonly used existing copy-protection tests, may also be applied in block 130 to determine the validity of the user material 101 . Similarly, the SDMI functions 120 may also include further protection-providing functions that are used to determine whether the output 121 is provided.
If, at 140 , the material 101 is determined to be illicit, or potentially illicit, the state of the process 100 is assessed to determine whether it contains phase II security screens. That is, the aforementioned security mark will contain an indication that phase II security screens are available. When illicit copies of the content material containing this mark are made, they will also contain the mark. Thus, when the user of the illicit copy attempts to play or record from this illicit copy, the test at 140 will detect this indication, and will advise the user, at 150 , that there's a problem rendering the user material 101 , and will further advise the user that an upgrade is available for the user's system. When the user upgrades the user's system in response to this advice, advanced screening techniques are provided, as illustrated by block 160 . That is, when the user upgrades to the Phase II system, the block 160 is provided or upgraded, via a memory device upgrade, a download from an Internet site, and so on. Other blocks, such as the SDMI functions block 120 , the mark detection block 130 , and the pre-processing block 170 may also be enhanced or modified by the upgrade. Thereafter, subsequent attempts to render or otherwise process illicit material will be subject to these enhanced security techniques. It is expected, for example, that one of the enhanced techniques will be a trace of the source of illicit material. That is, for example, future recording or providing systems may add a unique identifier to each provided material, identifying itself; for example, material downloaded from a web-site may contain that web-site name. When such material is determined to be illicit, the block 160 may provide a message such as: “This material has been illicitly obtained from site xxx.com, and the performers are being deprived of their royalty rights. Please refrain from purchasing material from xxx.com.” In this manner, the unintentional purchaser of illicit material is advised of the nature of the product he or she is receiving from the identified site, and will seek another source for the desired material. Eventually, the identified providers of illicit material will lose their customer base to the authorized providers, and the economic infeasibility of providing such illicit material to a dwindling customer base will force the illicit operation to shut down. Also, advanced systems may be configured to communicate this information to a central authority, so that preventive measures may be taken to prevent future losses.
SUMMARY OF THE INVENTION
It is an object of this invention to improve the effectiveness of a phased approach to screening for illicit copies of copy-protected material.
This invention is based on the observation that, after some experience with the conventional phased approach of FIG. 1 , the intentional users of illicitly obtained copies of copy-protected material will “spread the word”, via, for example, the Internet, advising both the intentional users and unintentional users of illicit material of the perils associated with upgrading. Thereafter, a dwindling number of people will be expected to voluntarily upgrade their systems, and the phased approach to advanced security will likely fail.
The object of this invention is achieved by testing for the availability of an enhanced version of a screening system and forcing an upgrade to the advanced screening system when material that complies with the existing standards is being processed. When security standards change, and corresponding security techniques are available for downloading to existing consumer devices, newly published content material will contain an indication to that effect. When the newly published content material is processed by an existing consumer device, the consumer device will detect this indication of an available update, and will prevent the processing of this newly published content material until the update is received. In this manner, a phased approach to enhanced security can be effected.
BRIEF DESCRIPTION OF THE DRAWINGS
The invention is explained in further detail, and by way of example, with reference to the accompanying drawings wherein:
FIG. 1 illustrates an example conventional screening process for illicit copies of copy-protected content material;
FIG. 2 illustrates an example screening process for illicit copies of copy-protected content material in accordance with this invention; and
FIG. 3 illustrates an example block diagram of a system for screening for illicit copies of copy-protected content material in accordance with this invention.
Throughout the drawings, the same reference numerals indicate similar or corresponding features or functions.
DESCRIPTION OF THE PREFERRED EMBODIMENTS
As noted above in the Summary Of The Invention, the conventional approach to a phased upgrade of security measures, enforces the phased upgrade on users who attempt to play or otherwise process illicit copies of copy-protected material. That is, consistent with a non-intrusive approach to the enforcement of copy protection, the conventional approach does not impose a burden on the user until the user commits a wrong. Although this approach is minimally intrusive, it has the potential of being minimally effective. When wrong-doers determine that upgrading their system provide no benefit to them, they will cease such upgrades. Because messages can now be effectively communicated virtually worldwide to large portions of the population, the wrong-doers can also influence others, particularly unknowing wrong-doers, to also cease such upgrades. Thus, the conventional upgrade strategy of FIG. 1 that provides no tangible benefits for upgrading is likely to fail.
FIG. 2 illustrates an example alternative screening process 200 for illicit copies of copy-protected content material in accordance with this invention. This alternative screening process 200 does impose a burden on the users of legitimate copies of copy-protected material, but the burden is not considered to be overbearing. As in FIG. 1 , the user material 101 is tested for the presence of an SDMI-authorization, at 110 . If the material 101 is an SDMI-authorized copy of copy-protected material, the update status of the system is tested, at 220 . The SDMI-authorized material includes an indication of the phase of the upgrade strategy that was in effect when the material 101 was generated. If the current state of the system is not up-to-date with this phase, the user is advised to upgrade the system, at 150 . Alternatively, if the current state of the system is at the indicated phase, or at a higher phase, the system is up-to-date, and the SDMI-authorized material is provided to the SDMI functions 120 for rendering 121 or other processing.
By preventing access to the SDMI functions 120 when the system is determined to be out-of-date, the user's “incentive” for upgrading the system is the rendering of this new content material having the higher upgrade indication. In this manner, users are likely to continue to upgrade the system at each phase of a phased security-upgrade process. To ease the “surprise” factor associated with having to unexpectedly or inconveniently upgrade the system, the packaging of the content material could include an indication of the applicable upgrade level, and the user could effect the upgrade before attempting to render or otherwise process newly acquired content material. Alternative techniques, common in the art, may also be utilized, such as an automatic notification of new upgrades to users via e-mail messages, and the like.
As in the process of FIG. 1 , legitimate copies of non-SDMI material (SDMI(L)), typically copies that do not have a copy-protection marking, such as a watermark, are identified at 130 , and pre-processed for SDMI processing, at 170 . Non-legitimate copies of non-SDMI material (SDMI(NL)), typically copies of content material having copy-protection marking but not an appropriate SDMI-authorization, are rejected for rendering or other processing, at 260 . The processing will be dependent upon the current upgrade state the system. That is, for example, if the system has been upgraded to identify the source of the illicit material, the processing at 260 will include the “do not purchase material from xxx.com” messaging discussed above with regard to FIG. 1 .
FIG. 3 illustrates an example block diagram of a system 300 for identifying illicit copies of copy-protected content material in accordance with this invention. A format checker 310 checks the content material 101 to determine whether the material is authorized content material, using for example, standards established by the SDMI. A status determinator 320 extracts an upgrade status indicator from the authorized content material 311 , and compares it to a system upgrade state 302 , to produce an upgrade status 321 . As noted above, the upgrade status indicator is associated with the content material 101 , preferably cryptographically bound to the material 101 , and indicates a version of upgrade that is available for the system. This version indicator is typically the latest version of the upgrade that was available when the content material 101 was created. In the context of this invention, the upgrade version indicator facilitates an identification of a new phase of copy-protection in a copy-protection system, although the principles presented herein can be applied for other upgrade strategies and applications as well. Note that, in a conventional upgrade process, such as illustrated in FIG. 1 , the upgrade status indicator is encoded as an “in-band” signal relative to the content material. That is, the status indicator is conventionally encoded within the content material, so that it cannot be easily removed from the material. In accordance with this invention, on the other hand, the status indicator is determined after the content material is verified as being authorized, and there is little or no incentive to remove it. Alternatively, the format checker 310 can be configured to assure that a status indicator is present before declaring that the material is authorized. Thus, the status indicator in this invention can be encoded as an out-of-band signal, which, as is commonly known in the art, is often easier to extract and determine than a conventional in-band signal. As a further measure of security, the status indicator in a preferred embodiment is bound to the content material, using a digital signing technique or similar security measure.
A processor 330 processes the content material 101 in dependence upon the upgrade status 321 . If the system upgrade state 302 is at the level determined from the upgrade status indicator associated with the content material 101 , or higher, the processor 330 processes the content material 101 to provide a rendered output 121 . Note that an acceptable upgrade status 321 is only produced from authorized content material 311 . The upgrade status 321 is also provided to a notification device 340 that notifies a user when the system 300 is out-of-date relative to the status indicator included with the content material 101 .
If the content material 101 is not-authorized 312 , that does not necessarily imply that the material is illegitimate. A copy-protection detector 350 is configured to detect the presence of a copy-protection scheme, such as a watermark, on the not-authorized content material 312 . If the not-authorized material 312 contains a copy-protection mark, then it must be an illicit copy of copy-protected material, and the processor 330 is configured to prevent the rendering or other processing of the content material 101 if the copy-protection flag 351 is asserted, and, optionally, to utilize the notification device 340 to recommend an upgrade. Conversely, if the not-authorized material 312 does not contain a copy-protection mark, the copy-protection detector 350 does not assert the copy-protection flag, and the processor 330 renders or otherwise processes the content material 101 without constraint.
The foregoing merely illustrates the principles of the invention. It will thus be appreciated that those skilled in the art will be able to devise various arrangements which, although not explicitly described or shown herein, embody the principles of the invention and are thus within its spirit and scope. For example, the test block 220 or the processor 330 may be structured to allow the user material 101 to be rendered or otherwise processed for a limited number of times before preventing such rendering or other processing based on an out-of-date upgrade. That is, the system will display a message indicating that the system needs to be updated, and will cease to render the higher-upgrade-status content material after the next 5 plays. Contrarily, the test block 220 or the processor 330 may be structured to prevent any subsequent processing of content material 101 upon the first determination of an outdated upgrade status. That is, the test block 220 could prohibit subsequent access to the functions 120 regardless of the upgrade indicator on subsequent user material 101 . Combinations of these approaches, and others, will be evident to one of ordinary skill in the art. These and other system configuration and optimization features will be evident to one of ordinary skill in the art in view of this disclosure, and are included within the scope of the following claims. | Copy-protected content material is screened for an indication of the availability of an enhanced version of a screening system and forcing an upgrade to the advanced screening system by refusing to process the copy-protected content material until the upgrade is preformed. When security standards change, and corresponding security techniques are available for downloading to existing consumer devices, newly published content material will contain an indication to that effect. When the newly published content material is processed by an existing consumer device, the consumer device will detect this indication of an available update, and will prevent the processing of this newly published content material until the update is received. In this manner, a phased approach to enhanced security can be effected. | 6 |
CROSS-REFERENCE TO RELATED APPLICATIONS
[0001] This application is a U.S. national stage application of International Application No. PCT/EP2005/056048 filed Nov. 18, 2005, which designates the United States of America, and claims priority to German application number 10 2005 000 731.7 filed Jan. 4, 2005, the contents of which are hereby incorporated by reference in their entirety.
TECHNICAL FIELD
[0002] The invention relates to a fuel supply system for a motor vehicle having a fuel pump which is designed to deliver fuel via a feed line to an internal combustion engine of the motor vehicle, having a suction jet pump for delivering fuel, and having a valve for controlling the capacity of the suction jet pump.
BACKGROUND
[0003] Fuel supply systems of said type are often used in modern-day motor vehicles and are known from practice. The suction jet pump is arranged in a return line leading from the internal combustion engine into the fuel tank or is supplied by the fuel pump with fuel as a propellant. The valve of the known fuel supply system ensures that the suction jet pump has a sufficient delivery capacity even in the case of a low propulsion quantity of fuel. Since the propulsion pressure of fuel can be subject to intense fluctuations, the valve is preloaded by a spring force into a closed position. With increasing pressure, the valve is opened and the suction jet pump obtains fuel as propellant. With increasing pressure, the opening of the valve increases, as a result of which the delivery capacity of the suction jet pump increases.
[0004] A disadvantage of the known fuel supply system is that, in the case of a variable propulsion pressure, the delivery capacity of the suction jet pump varies. At a high propulsion pressure, the propulsion quantity is therefore too high. This however results in a loss of hydraulic power.
SUMMARY
[0005] According to an embodiment, a fuel supply system for a motor vehicle having a fuel pump which is designed to deliver fuel via a feed line to an internal combustion engine of the motor vehicle, comprising a suction jet pump for delivering fuel, and a valve for controlling a capacity of the suction jet pump, wherein the valve is designed to reduce, with rising propulsion pressure, the size of an opening which is designed to supply the suction jet pump with fuel as a propellant. Such a suction jet pump has a constant delivery capacity largely independently of the propulsion pressure.
BRIEF DESCRIPTION OF THE DRAWINGS
[0006] The invention permits numerous embodiments. Two of these are described below in order to further clarify its basic principle. In the figures:
[0007] FIG. 1 shows a fuel supply system according to an embodiment for a motor vehicle,
[0008] FIG. 2 is a greatly enlarged sectioned illustration of a nozzle of a suction jet pump of the fuel supply system from FIG. 1 ,
[0009] FIG. 3 shows a side view of the nozzle of the suction jet pump from FIG. 2 ,
[0010] FIG. 4 shows a side view of a further embodiment of the nozzle of the suction jet pump from FIG. 2 .
DETAILED DESCRIPTION
[0011] As a result of said design, it is possible to design the suction jet pump for a minimum propulsion pressure and a minimum propulsion quantity. With rising propulsion pressure, the opening of the valve is reduced in size, and therefore a loss of hydraulic power as a result of excessive delivery of fuel to the suction jet pump is avoided. As a result, the propulsion quantity falls with rising propulsion pressure. In the case in particular of internal combustion engines which operate on the Otto principle, it has proven to be advantageous if a nozzle of the suction jet pump is connected to the feed line. It is possible in this way for the fuel pump to also be controlled according to the fuel demand of the internal combustion engine, and to ensure that none of the hydraulic power generated by the fuel pump is lost.
[0012] The fuel supply system according to various embodiments is of particularly simple structural design if the valve and the nozzle of the suction jet pump are designed as a structural unit. A further advantage of this configuration is that the suction jet pump and the valve require a particularly small amount of installation space.
[0013] According to another embodiment, it is possible in a simple manner to ensure a sufficiently powerful propellant jet when the valve is partially closed if a valve body of the valve projects into the opening of the nozzle of the suction jet pump. As a result of said configuration, the opening of the valve is at the same time the opening of the nozzle of the suction jet pump.
[0014] The control of the cross section of the nozzle of the suction jet pump requires particularly little structural expenditure if a valve body is guided so as to be axially moveable and has a narrowing section and projects with the narrowing section into the opening of the nozzle of the suction jet pump. As a result of said configuration, the valve body is acted on with the pressure generated by the feed line and the lower, ambient pressure situated downstream of the nozzle. The position of the valve body and therefore of the narrowing section is thereby adjusted, which results in the setting of a corresponding cross section of the nozzle of the suction jet pump. In the simplest case, the narrowing section is of conical design.
[0015] According to another embodiment, in the case of a low propulsion pressure shortly after the start of the fuel pump, the suction jet pump obtains a sufficient quantity of fuel as propellant if the valve has a spring element which preloads the valve body into a basic position in which the opening is at its largest. As a result of said configuration, the spring element preloads the valve body counter to the flow direction of the fuel.
[0016] According to another embodiment, the axially moveable guidance of the valve body requires a particularly low structural expenditure if the valve body is connected to a guide section, and if the guide section is guided in a tubular section of the valve and supports the narrowing section.
[0017] According to another embodiment, a turbulence-inducing flow deflection of the valve can be simply avoided if the tubular section directly adjoins a branch which is connected to the feed line.
[0018] According to another embodiment, the valve and the suction jet pump are of particularly compact configuration if the spring element is supported on a housing part, which has the opening of the nozzle, and on the guide section.
[0019] The structural unit composed of the valve and nozzle of the suction jet pump can be produced particularly cost-effectively if the narrowing section of the valve body and the opening of the nozzle of the suction jet pump are in each case round. In this way, the flow cross section of the nozzle of the suction jet pump is of annular configuration in every position of the valve body.
[0020] According to another embodiment, a contribution to a further reduction of the turbulence in the region of the suction jet pump and of the valve is provided if the narrowing section of the valve body has at least one duct. As a result of said configuration, the nozzle of the suction jet pump can generate one or more sufficiently intense propellant jets in every position of the valve body. In the simplest case, the duct is formed by a flattened portion on the valve body. The narrowing is preferably formed here by the duct. Here, the valve body can be cylindrical.
[0021] According to another embodiment, a contribution to a reduction of the energy consumption of the fuel pump is provided if the output capacity of the fuel pump can be regulated according to the fuel demand of the internal combustion engine. In fuel supply systems of said type, a low electrical voltage is applied to the fuel pump if only a small quantity of fuel is to be delivered to the internal combustion engine. If the fuel demand of the internal combustion engine rises, then the voltage applied to the fuel pump is increased. Here, the valve ensures that the suction jet pump obtains a sufficient quantity of fuel as propellant.
[0022] In the event of a brief high fuel demand of the internal combustion engine, it is possible for the entire amount of fuel delivered by the fuel pump to be delivered to the internal combustion engine if the valve body completely closes the opening at a designated high pressure in the feed line.
[0023] FIG. 1 shows a fuel supply system for supplying an internal combustion engine 1 of a motor vehicle with fuel from a fuel tank 2 . The fuel supply system has a surge pot 3 arranged within the fuel tank 2 and a fuel pump 4 which delivers fuel from the surge pot 3 via a feed line 5 to the internal combustion engine 1 . The capacity of the fuel pump 4 is controlled as a function of the fuel demand of the internal combustion engine 1 . Furthermore, the fuel supply system has two suction jet pumps 6 , 7 , one of which delivers fuel from a chamber 8 of the fuel tank 2 into the surge pot 3 . The other suction jet pump 6 delivers fuel from the chamber 9 into the surge pot 3 . The suction jet pumps 6 , 7 are in each case supplied with fuel as propellant via a branch 10 , 11 which leads away from the feed line 5 , and have in each case one nozzle 14 , 15 arranged upstream of a mixing tube 12 , 13 . Furthermore, in each case one valve 16 , 17 is arranged in the branches 10 , 11 . The valves 16 , 17 serve to regulate the volume flow rate of fuel which the suction jet pumps 6 , 7 obtain.
[0024] FIG. 2 is a greatly enlarged sectioned illustration through a structural unit of the valves 16 , 17 and of the nozzles 14 , 15 of the suction jet pumps 6 , 7 from FIG. 1 . The structural units are of identical construction. It can be seen here that a valve body 18 of the valve 16 , 17 has a narrowing section 19 with which it projects into an opening 20 of the nozzle 14 , 15 of the suction jet pump 6 , 7 . The narrowing section 19 is of conical design and is connected to a guide section 21 . The valve body 18 is guided so as to be axially moveable in a tubular section 22 which adjoins the branch 10 , 11 which leads away from the feed line 5 from FIG. 1 . A spring element 23 preloads the valve body 18 counter to the flow direction in the tubular section 22 . With increasing pressure in the section 10 , 11 which branches off from the feed line 5 in FIG. 1 , the valve body 18 is moved counter to the force of the spring element 23 and reduces the flow cross section of the opening 20 of the nozzle 14 , 15 .
[0025] The valve 16 , 17 is illustrated in a central position in which the narrowing section 19 projects into the opening 20 of the nozzle 14 , 15 . In this way, the flow cross section of the opening 20 is of annular design, as can be clearly seen in FIG. 3 in a side view of the nozzle 14 , 15 . In order to completely close off the opening 20 , the valve body 18 can additionally have a bead (not illustrated).
[0026] FIG. 4 shows a further embodiment of the nozzle 14 , 15 of the suction jet pumps 6 , 7 from FIG. 1 in a side view, in which the valve body 18 of the valve 16 , 17 has ducts 24 . In this way, the nozzle 14 , 15 of the suction jet pump 6 , 7 generates individual propellant jets. | A fuel supply system for a motor vehicle has a sucking jet pump ( 6, 7 ) which is connected to a flow line ( 5 ). The valve ( 16, 17 ) reduces the cross-section of an opening ( 20 ) in a nozzle ( 14, 15 ) of the sucking jet pump ( 6, 7 ) with increasing pressure in the flow line ( 5 ). Hydraulic losses in supplying the sucking jet pump ( 6, 7 ) with fuel as a pump fluid are prevented and the conveying performance of the sucking jet pump ( 6, 7 ) is maintained, preferably, at a constant level. | 8 |
BACKGROUND OF THE INVENTION
[0001] 1. Field of the Invention
[0002] The present invention relates to a micro-sample processing and observation technology using a focused ion beam.
[0003] 2. Background Art
[0004] With the micronization of semiconductors, the need to observe and analyze microstructures has greatly increased. Focused Ion Beam (hereinafter abbreviated to FIB) apparatuses are capable of processing micro-samples, and can therefore be used, in particular, as sample pre-processing apparatuses for apparatuses capable of observing micro-samples, such as Scanning Electron Microscopes (hereinafter abbreviated to SEM), Scanning Transmission Electron Microscopes (hereinafter abbreviated to STEM), and Transmission Electron Microscopes (hereinafter abbreviated to TEM). Since FIB techniques allow the imaging of secondary particles (such as secondary electrons) generated by a sample and the setting of a processing region based on the images, it is possible to form a section at a desired point in the sample, and have a capability which is of great benefit in the diagnosis of faults. Since the micronization of semiconductor structures has proceeded further in recent years, the use of high resolution STEMs or TEMs in the observation of samples has increased. To allow observation by STEMs and TEMs, it is necessary to extract a sample from the substrate and process the extracted sample to a thinness that is transparent to an electron beams. The FIB has various uses in this process.
[Patent Document 1] JP Patent Application (Kokai) No. 5-52721 (1993).
SUMMARY OF THE INVENTION
[0006] The technological issue with regard to the micronization of the sample is to judge at what point to end the FIB processing, and to control the processing so that the portion to be observed is left over in the center of the thin film. To realize a solution, a method is now in use whereby an FIB and an SEM are installed in the same sampling chamber, the section being processed by the FIB is observed using the SEM, and the point at which to end the process is judged accordingly. However, to realize microstructures having special electrical properties materials which are extremely sensitive to electron beam radiation, known as low-k materials, are widely used, and consequently there are many instances where sample broken or deformed by the SEM observation. Various methods have been considered and tested as ways to prevent such damage. These include (1) reducing the amount of damage by cooling the sample, and (2) dramatically reducing the acceleration voltage of the electron beam so as to reduce an irradiation energy. Method (1) has the disadvantage that time is required for cooling and exchanging samples, dramatically reducing throughput of the process. Also, since electron-beam irradiation causes local damage, deformation will occur at the observed portion despite the cooling of the sample stage if the cooling path is insufficiently secure. Method (2) has the disadvantage that the imaging resolution is lower by the reduction in the acceleration voltage of the electron beam, making it difficult to check the microstructure.
[0007] The object of the present invention is to implement thin film processing with a high positional accuracy for a sample constructed from a material vulnerable to electron beam radiation while suppressing breakage and deformation, so as to allow observation of the microstructures of the sample.
[0008] The present invention relates to the provision of a capability to monitor a cross-sectional structure during FIB processing by making use of secondary particles generated from the sample as a result of the milling of the cross-section instead of an electron beam.
[0009] Display of the cross-section microstructure is possible by setting a strip-like processing region at an inclined portion of the sample cross-section, and enlarging the display on the processing monitor in a direction corresponding to a short-side of the strip-like processing region. It is then possible to check the structure of the cross-section without using an electron beam. Since it is possible to check the cross-section being processed without using an electron beam, the damage and deformation which would result from use of an electron beam on the cross-section being processed do not occur. By implementing the observation with a high-acceleration electron beam after creation of the thin film, it is possible to perform the observation with reduced sample damage, and then to fabricate an even thinner film using the FIB while observing a sample image resulting from an electron beam.
[0010] According to the present invention, it is possible to perform FIB cross-section processing and thin film processing while suppressing damage and deformation to a sample cross-section. Also, by combining the FIB with a high-acceleration SEM, STEM, and TEM, it is possible to observe the sample in which the damage and deformation have been minimized at a high resolution.
BRIEF DESCRIPTION OF THE DRAWINGS
[0011] FIG. 1 shows an image monitor window used in a first embodiment of the present invention.
[0012] FIG. 2 shows an image monitor window used in the first embodiment of the present invention.
[0013] FIG. 3 is a processing shift window used in the first embodiment of the present invention.
[0014] FIG. 4 shows an image monitor window used in a second embodiment of the present invention.
[0015] FIG. 5 is a system construction of the FIB apparatus used in the first embodiment of the present invention.
[0016] FIG. 6 is a block diagram of an image display circuit used in the first embodiment of the present invention.
[0017] FIG. 7 shows a construction diagram of the FIB-SEM apparatus used in a third embodiment of the present invention.
[0018] FIG. 8 shows a micro-sampling procedure used in the third embodiment of the present invention.
[0019] FIG. 9 is a process flowchart used in the first embodiment of the present invention.
[0020] FIG. 10 is a thin film processing procedure used in the third embodiment of the present invention.
[0021] FIG. 11 is a processing flow chart used in the third embodiment of the present invention.
[0022] FIG. 12 shows a construction of the FIB-SEM apparatus used in a fourth embodiment of the present invention.
[0023] FIG. 13 is a thin film processing procedure used in the fourth embodiment of the present invention.
DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS
[0024] The present invention makes it possible to monitor a cross-sectional structure during FIB processing using a secondary particle image generated from the sample as a result of the milling of the cross-section by FIB rather than as a result of an electron beam.
[0025] In a final stage of the milling of the cross-section, the processing region has a long thin strip-like form and the monitor image generally has a strip-like form. The judgment of the end point of the processing using the monitor image was conventionally performed based on an average brightness over the entire monitor. Hence, although it was possible to roughly gain an understanding of a process by which the cross-section processing proceeded from a surface towards a substrate side of the sample, it was difficult to gain an understanding of the structure of the cross-section. For this reason, the use of an SEM has been considered.
[0026] In the embodiments, the monitor picture was enlarged in a short-side direction of the strip-like form, making it possible to gain an understanding of the cross-sectional structure as the processing using the FIB alone proceeded.
[0027] The processing cross-section generally formed by FIB processing has an inclination of a few degrees relative to the angle of incidence of the ion beam because of a relationship between a local angle of the ion beam incident on the sample and a sputtering yield (J. Vac. Sci. Technol. B9(5). September/October 1991, pp 2636). In the embodiments it is possible to display the structure of the cross-section by making use of this physical phenomenon, setting the strip-like processing region in the inclined portion, and expanding the picture on the process monitor in the short-side direction. Since the beam irradiates from an inclined direction approximately parallel to the cross-section, the image resolution deteriorates more than the beam diameter, but it is possible to display an image of sufficient resolution to roughly gain an understanding of, for instance, whether a wiring structure is present in the cross-section structure. When the section structure is checked using the above-described function and the desired section has not been achieved, the desired cross-section can be achieved by repeatedly shifting the process region in the cross-section direction and making judgments about the cross-section structure. Since it is possible to create the desired section without using the SEM, the method is suitable for samples which are vulnerable to electron beam irradiation.
[0028] It is possible to manufacture the thin film sample with a high positional accuracy by applying the above-described method for forming the cross-section to at least one side of the thin film. When the thin film reaches a thickness of approximately 0.3 μm or less, conditions are reached under which an electron beam having an acceleration voltage of 15 kV or more is able to pass through the sample more easily and energy loss in the sample is small, and sample damage consequently becomes less likely. Hence, the sample can be formed into thin film using the FIB alone, and the resulting sample, for which damage and deformation have been suppressed, can be observed using an SEM, STEM, or TEM under high-acceleration conditions.
[0029] Also when additional processing is necessary, it is possible to form an even thinner thin film by performing additional FIB processing while monitoring at least one image from an SEM, an STEM, or a TEM under high-acceleration conditions. Since it is possible at this point to perform the monitoring using an electron beam having a high acceleration voltage, the end point of the FIB processing can be judged using a high-resolution image.
[0030] The present embodiments makes it possible to monitor the structure of the cross-section during FIB processing using a secondary particle image generated from the sample as a result of FIB milling of the cross-section. By setting a strip-like processing region at an inclined portion of the sample cross-section and enlarging the corresponding monitor picture in the short-side direction, it is possible to display the cross-section structure (section view). When the section structure is checked using the above-described function and the desired cross-section has not been achieved, the desired cross-section can be achieved by repeatedly shifting the processing region in the cross-section direction and making judgments about the cross-section structure. Since it is possible to create the desired cross-section without using the SEM, this method is suitable for processing samples which are vulnerable to electron beam radiation.
[0031] It is possible to manufacture the thin film sample with a high positional accuracy by applying the above-described method for forming the cross-section to at least one side of the thin film. By performing the observation using electrons which have been highly accelerated using a voltage of 15 kV or more after forming the thin film, the observation is possible in a manner which suppresses sample damage and deformation. Moreover, by performing further thin film processing while observing images obtained under the above-described conditions, it is possible to produce of a sample which is even thinner with a high degree of positional accuracy, and to observe the sample at high resolutions.
[0032] The following describes the embodiments with reference to the drawings.
First Embodiment
[0033] FIG. 5 shows a construction of an FIB apparatus used in a first embodiment of the present invention. An FIB 3 generated by the FIB column 100 is focused on and scanned across a sample 1 . Secondary electrons 2 emitted from the sample are detected by a detector 101 , converted to digital values via a signal processing unit 112 , and stored in an image memory in an image displaying unit 113 . The storage to the image memory is controlled using a deflection address from a deflection signal generation unit 110 . The apparatus includes an XY independent zoom ratio address converting unit 111 , and is capable of altering display ratios for the X and Y axes independently.
[0034] FIG. 6 shows circuits surrounding the image memory of the image display unit. Changes to the zoom ratios and the addresses are realized by a digital adder and a barrel shift circuit. Further, a dual port memory which is capable of performing the reading and writing of data is asynchronously used as the image memory.
[0035] FIG. 9 is a flowchart showing a procedure of the first embodiment. First, rectangle processing was performed in the region of a fault to form an initial cross-section. Next, a Scanning Ion Microscope (hereinafter SIM) image 201 was displayed in an image monitor window 200 as shown in FIG. 2 , a strip-like processing region 203 was set in a (minutely inclined) cross-sectional portion of the sample, and processing was started. When the processing is started, a processing monitor image 204 is displayed as shown in FIG. 1A . When a cross-section view display button 202 was pressed in the image monitor window 200 , the y-axis of the processing monitor was stretched as shown in FIG. 1B , and it became possible to recognize a cross-section structure in the image monitor (section view 205 ).
[0036] Since the desired section was not exposed by the initial processing, a shift amount and a shift direction for the processing region were set using the processing shift window shown in FIG. 3 , and the processing position was shifted in a cross-section direction. A shift amount of 2 dots (twice a minimum unit of a processing scanner) was set using a shift distance setting arrow button 212 a , and the shift was executed using a processing position shift arrow button 211 a . In the present embodiment, an observation and shift in processing position were executed 3 times. It was then possible to confirm that a desired cross-section structure had been realized, and the processing was ended. After completion of the processing, the sample was inclined and an SIM image observation of the cross-section was performed.
[0037] Since it is possible, according to the present embodiment, to check the cross-section structure during the processing of the cross-section using the FIB, the sample does not need not be inclined to check each cross-section, and an improvement in efficiency of output and throughput of FIB cross-sections can be achieved. Moreover, in the FIB cross-section processing before observation of the cross-section, observation of the cross-section using an electron beam during the FIB processing is unnecessary, and the processing method can therefore be said to be appropriate for the processing of materials which are vulnerable to electronic beam irradiation. In the present embodiment, the processing region was set to be strip-like in form, but trapezoidal and other forms other than strip-like forms may be used provided that it is possible to realize processing in the region of the cross-section.
Second Embodiment
[0038] FIG. 4 shows an image monitor window used in a second embodiment. In the second embodiment, the section view function includes a function for expansion of images in the x-direction as well as the function for the expansion of images in the y-direction. Moreover, the respective expansion ratios can be set individually. Hence, the display settings can be finely adjusted to match the sample, and judgments about the processing cross-section are simplified.
[0039] FIG. 4A shows the operation state of the standard processing monitor when the zoom ratios are “1” for both the x-direction and the y-direction. FIG. 4B shows the same section view display as in the first embodiment but with a y-axis zoom ratio of “8”.
Third Embodiment
[0040] The third embodiment describes an example in which the manufacture and observation of a thin-film sample are performed. The apparatus which was used is a compound apparatus having an FIB column 100 and an SEM column 150 installed in a same sample chamber. A gas source 170 for performing beam induced deposition and a manipulator 140 for handling the micro-samples are also installed in the sample chamber. Moreover, a large-sample stage 160 for holding and moving a sample 1 is installed in the sample chamber. Besides the sample 1 , a thin-film carrier 10 for mounting the micro-sample obtained by the sampling is also mounted on the sample stage.
[0041] FIG. 8 illustrates the (micro-sampling) method, implemented in the third embodiment, for extracting from a region to be observed. First, a first deposition film 1 is formed by FIB-induced deposition at the region of interest in the sample 1 which is fixed to the large-sample stage 160 . This was performed by supplying tungsten hexacarbonyl gas to the sample surface from the gas source 170 , and performing local irradiation with the FIB. Next hole processing was performed. The hole processing was implemented by performing groove processing on the surroundings of the first deposition film 1 and then inclining the sample and performing processing (FIB processing) to form slits at bottom portion. Next, the sample is returned to the original inclination, a tip of a probe (needle), which is attached to a tip of the manipulator 140 , is caused to contact an edge of the first deposition film 1 , and the first deposition film 1 is bonded to the probe tip by forming a second deposition film 2 using FIB-induced deposition. The connection between the substrate and the micro-sample is then cut by FIB irradiation and the probe is caused to rise so that the micro-sample including the region of interest is extracted. The large-sample stage 160 is then moved so that the thin-film carrier 10 enters the optical axis of the FIB. The micro-sample is then brought into contact with the thin-film carrier 10 and fixed to the thin-film carrier 10 using a third deposition film 3 . Thereafter, the second deposition film 2 is removed by FIB irradiation to separate the micro-sample and the probe.
[0042] According to this process, the micro-sample which includes the region of interest is transferred from the sample 1 to the carrier.
[0043] The micro-sample transferred to the carrier is then formed into a thin field using a process shown in FIG. 10 . The process to form the thin film is described below with reference the flowchart of FIG. 11 .
[0044] First, sectioning of the micro-sample was performed using the section view. The region of interest was a capacitor of a semiconductor sample, and the processing was completed when the cross-section at which a neighboring array of capacitors disappeared was found using the section view. A surface on a rear surface side of the sample was processed by setting a processing region that includes the capacitors and having a standard thickness of 0.3 μm, thereby forming the sample into a thin film. The processing of the rear surface can also be performed using the section view. Next, the film thickness was gradually reduced using FIB cross-section processing with the object of producing a section from a central part of the capacitors of interest. The end point of this process was found by checking cross-section information using an SEM with an acceleration voltage of 30 kV. Although the sample was composed of a material, known as a low-k material, which is vulnerable to electron beam irradiation, because the 30 kV electron beam passed through the thin film sample and the loss of energy in the sample was small, damage and deformation in the sample could be minimized.
[0045] The sample was then rotated 180°, and processing was performed on the rear surface in the manner described above with the result that a thin film containing a central portion of the capacitor and having a thickness of 60 nm is formed.
[0046] Thus, by performing final finishing processing to produce a thin film while checking the section using a high-acceleration electron beam after the thin film processing using of the section view, it is possible to realize thin film processing which minimizes damage and deformation and gives a high level of positional accuracy, even for materials which are vulnerable to damage and deformation by electron beam irradiation. The thin films of each carrier resulting from the processing were then transferred to the high acceleration STEM or TEM holders, and observation of high resolution images was performed.
Fourth Embodiment
[0047] The fourth embodiment is an example in which the cross-section monitoring during the finishing of the thin film is implemented with STEM imaging. The construction of the apparatus is shown in FIG. 12 . In the inclusion of an FIB, an SEM and a gas source, the present apparatus resembles that of FIG. 7 . However, the present apparatus further includes a side entry stage 180 and a STEM detector 102 . A needle-form carrier 8 is mounted on the side entry stage 180 , and a holder having mechanism for rotating the needle-form carrier 8 is installed in the side entry stage 180 .
[0048] The micro-sample 5 , which has been separated from the sample 1 , was fixed using FIB induced-deposition to the tip of the needle-form carrier 8 on the holder installed in the side entry stage 180 . The fixed micro-sample was then formed into a thin film using the procedure shown in FIG. 13 . The procedure of FIG. 13 resembles the procedure of FIG. 10 but differs in that an STEM is used in the electron-beam observation of the cross-section structure during the finishing processing. The STEM image is captured by detecting an electron beam which passed through the thin film using an STEM detector 102 . To proceed from (3) to (4) in the process shown in FIG. 13 , it is necessary to rotate the sample. In the present embodiment, the needle form carrier 8 was rotated using the rotation mechanism 190 in the holder.
[0049] The micro-sample which has been formed into a thin film is installed in the side-entry holder. It is then possible to perform imaging and observation at even higher resolutions by removing and transferring the holder to dedicated TEM and STEM devices. Since the present embodiment does not require the carrier to be attached and removed once the micro-sample has been installed, the risk of damage or loss to the sample during work on the sample is low. This method is therefore suitable for fault analysis in which it is difficult to secure a plurality of samples. | As sample sizes have decreased to microscopic levels, it has become desirable to establish a method for thin film processing and observation with a high level of positional accuracy, especially for materials which are vulnerable to electron beam irradiation. The technological problem is to judge a point at which to end FIB processing and perform control so that the portion to be observed ends up in a central portion of the thin film. The present invention enables display of structure in cross-section by setting a strip-like processing region in an inclined portion of a sample cross-section and enlarging the display of the strip-like processing region on a processing monitor in a short-side direction. It is then possible to check the cross-sectional structure without additional use of an electron beam. Since it is possible to check the processed section without using an electron beam, electron beam-generated damage or deformation to the processed section is avoided. Further, performing the observation using a high-speed electron beam after forming the thin film enables observation with suppressed sample damage. Processing of even thinner thin films using the FIB while observing images of the sample generated using an electron beam is then possible. | 7 |
FIELD OF THE INVENTION
The present invention relates generally to the field of surgical instruments utilizing light application via optical fibers placed within the body. More particularly, the present invention relates to endovenous laser therapy of the peripheral veins, such as greater saphenous veins of the leg, for treatment of varicose veins.
BACKGROUND OF THE INVENTION
Varicose veins are enlarged, tortuous and often blue in color and commonly occur in the legs below the knee. Varicose veins are the most common peripheral vascular abnormality affecting the legs in the United States. Varicose veins often lead to symptomatic venous insufficiency. Greater saphenous vein reflux is the most common form of venous insufficiency in symptomatic patients and is frequently responsible for varicose veins in the lower leg. This occurs in about 25% of women and about 15% of men.
All veins in the human body have valves that when functioning properly, open to allow the flow of blood toward the heart and close to prevent backflow of blood toward the extremities. The backflow of blood is also known as reflux. The venous check valves perform their most important function in the veins of the legs where venous return flow is most affected by gravity. When the venous valves fail to function properly, blood leaks through the valves in a direction away from the heart and flows down the leg in the wrong direction. The blood then pools in the superficial veins under the skin resulting in the bulging appearance typically seen in varicose veins. The pooling of blood in the leg veins tends to stretch the thin elastic walls of the veins, which in turn causes greater disruption in the function of the valves, leading to worsening of the varicosities. When varicose veins become severe, the condition is referred to as chronic venous insufficiency. Chronic venous insufficiency can contribute to the development of pain, swelling, recurring inflammation, leg ulcers, hemorrhage and deep vein thrombosis.
Traditionally, varicose veins have been treated by a surgical procedure known as stripping. In stripping, varicose veins are ligated and completely removed. More recently, varicose veins have been treated by endovenous laser therapy. Endovenous laser therapy treats varicose veins of the leg by eliminating the highest point at which blood flows back down the veins, thereby cutting off the incompetent venous segment. Endovenous laser therapy has significant advantages over surgical ligation and stripping. In general, endovenous laser therapy has reduced risks related to anesthesia, less likelihood of surgical complications, reduced costs and a shorter recovery period than ligation and stripping.
Endovenous laser therapy involves the use of a bare tipped or shielded tip laser fiber to deliver laser energy to the venous wall from within the vein lumen that causes thermal vein wall damage at the desired location. The subsequent fibrosis at this location results in occlusion of the vein that prevents blood from flowing back down the vein. Generally, endovenous laser therapy utilizes an 810 to 980 nanometer diode laser as a source of laser energy that is delivered to the venous wall in a continuous mode with a power of about 10 to 15 Watts.
An exemplary endovenous laser therapy procedure is disclosed in U.S. Pat. No. 4,564,011 issued to Goldman. The Goldman patent discloses the use of an optical fiber to transmit laser energy into or adjacent to a blood vessel to cause clotting of blood within the vessel or to cause scarring and shrinkage of the blood vessel.
A typical endovenous laser therapy procedure includes the location and mapping of venous segments with duplex ultrasound. An introducer sheath is inserted into the greater saphenous vein over a guidewire, followed by a laser fiber about 600 micrometers in diameter. The distal end of the laser fiber is advanced to within 1 to 2 cm of the sapheno-femoral junction. Laser energy is then applied at a power level of about 10 to 15 watts along the course of the greater saphenous vein as the laser fiber is slowly withdrawn. Generally, positioning of the laser fiber is done under ultrasound guidance and confirmed by visualization of the red aiming beam of the laser fiber through the skin. The application of laser energy into the vein utilizes the hemoglobin in red blood cells as a chromophore. The absorption of laser energy by hemoglobin heats the blood to boiling, producing steam bubbles which cause full thickness thermal injury to the vein wall. This injury destroys the venous endothelium and creates a full-length occlusion and destruction of the greater saphenous vein. An example of current techniques for endovenous laser therapy procedures is described in U.S. Patent Publication No. 2003/0078569 A1, the disclosure of which is hereby incorporated by reference.
While current endovenous laser therapy procedures offer a number of advantages over conventional ligation and stripping, challenges remain in successfully implementing an endovenous laser therapy procedure. The accurate localization of the bare distal end of the laser fiber can be difficult even with ultrasound assistance. In addition, a bare distal end of the laser fiber is transparent to fluoroscopy. Because of the relatively small diameter and sharpness of the laser fiber, the distal tip of the laser fiber can sometimes enter or puncture and exit the vein wall while the laser fiber is being advanced up a tortuous greater saphenous vein. Laser fibers used in current endovenous laser therapy procedures are glass optical fibers coaxially surrounded by protective plastic jacket or coating.
In current endovenous laser therapy procedures, a laser fiber is inserted into a vein while sheathed in a catheter. Because of the relative stiffness of the laser fiber and the fact that it is formed from glass, and the relatively sharp distal end of the laser fiber, the catheter allows for easier advancing of the laser fiber through the blood vessel. When the laser fiber-catheter combination has reached a desired location, typically slightly proximal from the sapheno-femoral junction, the laser fiber is advanced to extend beyond the distal end of the catheter by a significant distance. Laser energy is applied through the optical fiber and the catheter and laser fiber are withdrawn at the same time that the laser energy is applied.
An alternative approach includes placing a guidewire in the blood vessel, advancing the guidewire until it is in a desired location, then advancing a laser fiber which includes a structure for engaging the guidewire, along the guidewire until it is at the desired location, withdrawing the guidewire and then withdrawing the laser fiber while simultaneously applying laser energy to the blood vessel. In either case, these procedures require the insertion and removal of multiple structures into and out of the blood vessel. These multiple insertions and removals take time, and may also increase the likelihood of possible unintended injury or perforation of the blood vessel during the procedure.
Thus, there is still room for improvement to endovenous laser procedure and apparatus.
SUMMARY OF THE INVENTION
The present invention solves many of the above discussed problems. The present invention includes a laser fiber for endovenous therapy having a shielded laser emitting section and a guidewire distal to the shielded laser emitting section. The invention generally includes a hub for coupling the optical fiber to a laser source, an optical fiber, an insulative tip shield, a tip sleeve that surrounds the insulative tip shield and a guidewire tip.
The hub in accordance with the present invention is generally conventional and includes a coupling to be coupled to a laser console laser source as well as a strain relief to minimize stress on the optical fiber when the optical fiber is flexed relative to the laser source. In one aspect of the invention, the optical fiber is a 600 micron optical fiber with a plastic jacket. The plastic jacket may be marked with ruler marks to facilitate withdrawing the optical fiber from a vein at a desired rate. The optical fiber also may include an insulative tip shield secured to the optical fiber at its distal most end. In one aspect of the invention, the optical tip shield may be formed of a ceramic material.
The tip sleeve in accordance with the present invention is a generally cylindrical structure dimensioned to surround the distal end of the optical fiber. The tip sleeve may be formed of a metallic material, for example, an alloy of about 90% platinum and about 10% iridium is one suitable material. If an insulative tip shield is present the may also surround the insulative tip shield.
The tip sleeve surrounds the distal end of the optical fiber and extends beyond the distal end of the optical fiber by a significant distance. The tip sleeve in accordance with the present invention may include a pair of opposed proximal slits and three distal slits that are located more distal than the proximal slits. In one aspect of the invention, the proximal slits have a length significantly greater than the distal slits. The tip sleeve may be secured to the optical fiber and to the guidewire tip, for example, by crimping. In addition, the tip sleeve may be secured to the guidewire tip by welding and to the optical fiber by adhesives such as high temperature adhesives.
The guidewire tip may be crimped or otherwise secured to the distal end of the tip sleeve. In one aspect of the invention, the guidewire tip may be formed of stainless steel and have a diameter of about 0.035 inches. The guidewire tip may be formed as a coil wire having a core ribbon. The guidewire tip generally includes ball welds on each end full round in shape. The guidewire tip may be straight or curved as is known in the arts of guidewires in general. The guidewire may be any flexible extension that extends beyond the distal end of the optical fiber and that facilitates atraumatic advancement of the optical fiber through as bodily lumen. The guidewire may be formed of metal, polymer or any other suitable material.
BRIEF DESCRIPTION OF THE DRAWINGS
FIG. 1 is a plan view of a guidewire tipped optical fiber in accordance with the present invention.
FIG. 2 is a cross sectional view of an optical fiber tip and tip sleeve in accordance with the present invention taken along section line 2 - 2 of FIG. 1 .
FIG. 3 is a plan view of an optical fiber in accordance with the present invention.
FIG. 4 is a detailed plan view taken at designated area 4 of FIG. 3 .
FIG. 5 is a cross sectional view taken along section lines 5 - 5 of FIG. 3 .
FIG. 6 is a perspective view of the insulative shielded tip of an optical fiber in accordance with the present invention.
FIG. 7 is another plan view of optical fiber in accordance with the present invention.
FIG. 8 is a detailed view taken at designated area 8 of FIG. 7 .
FIG. 9 is a detailed view taken at detail area 9 of FIG. 7 .
FIG. 10 is a plan view of a tip sleeve and guidewire portion in accordance with the present invention.
FIG. 11 is an elevational view of the tip sleeve and guidewire portion as depicted in FIG. 10 .
FIG. 12 is a cross sectional view taken along section line 12 - 12 of FIG. 11 .
FIG. 13 is a plan view of a tip sleeve in accordance with the present invention.
FIG. 14 is an elevational view of a tip sleeve in accordance with the present invention.
FIG. 15 is a bottom plan view of a tip sleeve in accordance with the present invention.
FIG. 16 is a plan view of a guidewire portion in accordance with the present invention.
FIG. 17 is plain view of a cyrved guidewire in accordance with the present invention.
DETAILED DESCRIPTION
Referring particularly to FIGS. 1 and 2 , guidewire tip laser fiber 20 in accordance with the present invention, generally includes fiber hub 22 , optical fiber 24 , tip shield 26 , tip sleeve 28 and guidewire tip 30 . Starting from the most proximal end of guidewire tip laser fiber 20 , in an example embodiment, fiber hub 22 is coupled to and surrounds optical fiber 24 . The distal end of optical fiber 24 is surrounded by tip shield 26 . Tip shield 26 is surrounded by tip sleeve 28 , which terminates in guidewire tip 30 .
Referring to FIGS. 1 , 3 and 7 , fiber hub 22 is generally conventional in structure and includes coupler 32 and strain relief 34 . Coupler 32 is adapted to couple fiber hub 22 to a console laser source (not shown). Coupler 32 and strain relief 34 surround the proximal end of optical fiber 24 . Coupler 32 can be a standardized connector such as an SMA-905 connector for connection to a laser source console (not shown).
In one aspect of the invention, optical fiber 24 is a 400-600 micron glass optical fiber having a finely polished distal tip end. However, a polymer fiber can be used as well. Those skilled in the art will understand that the designated dimensions of the glass optical fiber refers to the diameter D of the fiber including the fiber core and cladding but exclusive of protective jacket 36 . The exterior dimensions of protective jacket 36 are larger. While a single optical fiber 24 is described herein, it should be understood that optical fiber 24 can also include a stranded arrangement of multiple optical fibers. Generally, optical fiber 24 is about 3.5 meters in length but this length should not be considered limiting.
The laser source console (not shown) may be, for example, a solid state diode laser console operating at a wave length of 810 nanometers, 940 nanometers or 980 nanometers and supporting a maximum power output of about 15 watts.
Protective jacket 36 coaxially surrounds optical fiber 24 throughout almost the entirety of its length. Protective jacket 36 is generally conventional in structure and may be formed from a biocompatible plastic material. Protective jacket 36 is removed from distal end 38 of optical fiber 24 . Typically, about one half to two centimeters of protective jacket 36 is removed.
Referring particularly to FIGS. 7 , 8 and 9 , protective jacket 36 , in one embodiment of the present invention, is marked with printed scale 40 . Printed scale 40 generally includes markings along the length of protective jacket 36 , for example, every centimeter. Printed scale 40 may be numerically identified, for example, every centimeter or every 10 centimeters or some other selected interval. Printed scale 40 may extend over substantially the entire length of protective jacket 36 of optical fiber 24 or may be limited, for example, to the distal eighty to one hundred centimeters.
Referring to FIGS. 2-6 , tip shield 26 covers substantially the entire exposed distal end 38 of optical fiber 24 . Tip shield 26 coaxially surrounds distal end 38 of optical fiber 24 while leaving distal tip face 42 exposed. Tip shield 26 may be formed of a rigid heat resistant insulative material such as ceramic or carbon. In one aspect of the invention, tip shield 26 extends slightly beyond distal tip face 42 of optical fiber 24 . Thus, distal tip face 42 of optical fiber 24 is recessed into tip shield 26 for example 0.005 inches plus or minus 0.003. This relationship is can be seen in FIGS. 5-6 .
Referring to FIG. 4 , tip shield 26 may be secured to optical fiber 24 , for example, by the use of high temperature adhesive 44 .
Referring to FIG. 2 , and 10 - 15 , tip sleeve 28 , in one embodiment of the invention, is a generally tubular cylindrical structure generally including body 46 , proximal crimp portion 48 , distal crimp portion 50 , proximal openings 52 and distal openings 54 .
Body 46 of tip shield 26 is a generally cylindrical structure which may be formed of a metallic material. In one embodiment of the invention, tip shield 26 may be formed of an alloy of approximately 90% platinum and 10% iridium. Body 46 is generally cylindrical in shape and is sized to fit over optical fiber 24 and tip shield 26 in a closely fitting relationship.
Proximal crimp portion 48 is positioned to cover distal jacket portion 56 of optical fiber 24 . Proximal crimp portion 48 may then be crimped or otherwise secured to distal jacket portion 56 . Proximal crimp portion 48 in one embodiment of the invention has a length of approximately one half millimeter.
Distal crimp portion 50 is sized to closely receive guidewire tip 30 therein. Distal crimp portion 50 may be secured to guidewire tip 30 by crimping or other fastening techniques such as welding.
Proximal openings 52 in one aspect of the invention are located near the proximal end of body 46 of tip shield 26 . In one aspect of the invention, proximal openings 52 may take the form of two elongate slits positioned opposite one another and extending lengthwise along body 46 .
In one embodiment of the invention, proximal openings 52 may have a length approximately 30% of the length of tip shield 26 . In one aspect of the invention, proximal openings 52 may be positioned to expose a proximal part of tip shield 26 and a portion of high temperatures adhesive 44 . As depicted, proximal openings 52 are positioned to be outside of proximal crimp portion 48 .
Distal openings 54 , in one aspect of the invention, are located proximal to and outside of distal crimp portion 50 . In one embodiment of the invention, distal openings 54 include three openings distributed evenly about the circumference of body 46 . Distal openings 54 in one aspect of the invention may have a length approximately five percent of the length of body 46 . Distal openings 54 in one aspect of the invention, are positioned to be located approximately at the distal end of tip shield 26 , and to extend beyond the distal end of tip shield 26 for a significant portion of their length.
Referring particularly to FIGS. 1 , 10 , 11 , 12 and 16 , guidewire tip 30 generally includes coil portion 58 , distal ball weld 60 and proximal ball weld 62 . Guidewire tip 30 may be straight, curved, bent, flexible, floppy, adjustable or non-adjustable similar to guidewires known in the guidewire arts. Guidewire tip 30 is sized to fit into distal crimp portion 50 of tip sleeve 28 .
Referring to FIG. 17 , in one example embodiment, guidewire tip 30 may be curved as pictured. Many other embodiments and shapes of guidewire tip 30 may be presented as well.
In operation, a physician prepares a laser console (not shown) in accordance with its operating instructions, and verifies that the guidewire tipped laser fiber 20 is properly connected to the laser console. The physician then maps the vessel treatment area using duplex ultrasound, being careful to mark the vessel location on the patient's skin for guiding treatment. The physician then preps and drapes the limb in sterile fashion and wraps the ultra sound transducer with a sterile cover. Using sterile technique, the physician opens the guidewire tipped laser fiber 20 and, if used, an introducer needle into the sterile field.
The physician can cannulate the vessel to be treated using a surgical cut down or the introducer needle. The guidewire tipped laser fiber 20 is inserted into the vessel through the incision or needle. If a needle is used, it is removed from the vessel. The guidewire tip laser fiber 20 is advanced through the vessel to the desired treatment site. The tip sleeve 28 in combination with the tip shield 26 prevents the vessel wall from contacting the optical fiber 24 . Guidewire tip 30 assists in advancing guidewire tip laser fiber 20 without the need for a catheter or separate guidewire. Anesthetic is delivered to bathe the surrounding tissue with dilute anesthetic to provide thermal protection.
The physician places the laser console in the ready mode and sets the power level to settings for the procedure. The physician holds the optical fiber 24 and activates the laser typically by stepping on a foot pedal. The physician then simultaneously withdraws the guidewire tip laser fiber 20 while delivering approximately 50-70 jewels per centimeter of laser energy. The physician should not compress or attempt to place the fiber in contact with the vein wall.
After the procedure is complete, the laser is turned to standby, guidewire tipped laser fiber 20 is removed from the blood vessel and compression is held on the wound until bleeding stops. A hemostatic bandage may be applied over the vessel entry site, and a compression stocking may also be applied over the entire treatment site length. The patient is then cared for under normal post-operative procedures and follow-up exams are scheduled as needed.
When guidewire tipped laser fiber 20 in inserted into a vein blood enters distal openings 54 and fills the interior of body 46 distal to distal tip face 42 of optical fiber 24 . Upon application of laser energy the blood is heated and gaseous products of the application to laser energy to the blood are expelled from the interior of body 46 through distal openings 54 . Tip sleeve 28 and guidewire tip 30 are also heated and transmit energy to the blood.
The present invention may be embodied in other specific forms without departing from the spirit of the essential attributes thereof, therefore, the illustrated embodiments should be considered in all respects as illustrative and not restrictive, reference being made to the appended claims rather than to the forgoing description to indicate the scope of the invention. | A device for application of energy within a tubular bodily structure including an optical fiber couplable to a source of laser energy and a guidewire tip. The optical fiber has a laser emitting portion remote from the source of laser energy and a distal end. The guidewire tip is operably secured to the optical fiber and extends distally outwardly away from the distal end of the optical fiber. The guidewire tip assists in advancing the device through the tubular bodily structure. | 0 |
CROSS REFERENCE TO RELATED APPLICATION
[0001] This application claims the benefit under 35 U.S.C. § 119(e) of the U.S. Provisional Application No. 60/705,370 filed Aug. 4, 2005, the disclosure of which is incorporated by reference in its entirety herein.
BACKGROUND OF THE INVENTION
[0002] The invention relates to a pharmaceutical formulation for oral administration comprising an effective amount of prednisolone acetate in a pharmaceutically acceptable, aqueous, suspension-stabilizing vehicle.
[0003] Corticosteroids are used to treat patients with inflammatory and immune diseases. Prednisolone is a corticosteroid that has been formulated into capsules, tablets and liquid preparations for oral delivery. The base form of prednisolone and the salt form, prednisolone sodium phosphate, are commercially available in oral liquid formulations. However, the bitter taste of the commercial compositions is described extensively in the medical literature and contributes to poor patient compliance with medical instructions for the use of the drug. U.S. Pat. No. 4,448,774 describes aqueous solutions comprising a steroid selected from the group of prednisolone, prednisolone sodium phosphate, prednisone and methyl prednisolone. The solution described in the patent is described as being preferable to previously known formulations because no alcoholic solvent is required and it is not a suspension. Suspensions of prednisolone are reported to be problematic because they are not stable and over time the active agent settles out of the formulation and gives variable dosage amounts. U.S. Pat. No. 5,763,449 describes the use of a combination of three well known taste masking agents to achieve a pleasant tasting liquid pharmaceutical composition. Prednisolone and prednisolone sodium phosphate are disclosed as bitter tasting drugs that may be used in the formulation.
[0004] Another form of prednisolone, prednisolone acetate, is commonly used for medicinal purposes. However, because of its poor aqueous solubility, prednisolone acetate is used in topical, parenteral and opthamalogical formulations, not oral formulations. The use of the acetate form could provide a taste advantage because it is insoluble in the aqueous environment of the mouth, and therefore prevents the interaction of the bitter-tasting molecules of the prednisolone with the taste buds.
[0005] The present disclosure is to a novel, organoleptic, oral, liquid suspension of prednisolone acetate that is an improvement over previously disclosed and commercialized oral prednisolone dosage forms.
SUMMARY OF THE INVENTION
[0006] The present invention is to a pharmaceutical composition for oral delivery comprising a pharmaceutically effective amount of prednisolone acetate, pharmaceutically acceptable vehicle and a thickening agent. The present composition contains between about 0.5 mg/mL to about 7 mg/mL of prednisolone acetate. More preferably the concentration of prednisolone acetate is between about 1 mg/mL to about 5 mg/mL. The most preferred compositions of the present invention will deliver 5 mg/5 mL prednisolone acetate or 15 mg/5 mL prednisolone acetate.
[0007] The inventive formulation has prednisolone acetate dispersed in an oral formulation comprising a vehicle and a thickening agent. The aqueous vehicle may be comprised of glycerin, and the preferred thickening agent is carbomer.
[0008] The prednisolone acetate of the present invention is within a fine range of particle size. The median particle size of the prednisolone acetate is between about 1 μm to 30 μm, particularly between about 5 μm to 10 μm, and more particularly between 6 μm to 8 μm. Ninety percent of the prednisolone acetate in the inventive composition has a median particle size of greater than 1 μm and less than 30 μm.
[0009] The inventive composition further comprises pharmaceutically acceptable excipients. The excipients include wetting agents, spreading agents, stabilizers, sweeteners and flavoring agents. The inventive composition is organoleptically pleasing.
[0010] The novel formulation has a pH of between about 4.0 to about 5.9, more preferably of between about 4.6 to about 5.4, most preferably 4.8 to 5.2.
[0011] The inventive composition is comprised of from about 29 to about 64% water (w/w), up to about 50% glycerin (w/w), up to about 20% sorbitol (w/w), up to about 10% propylene glycol (w/w), up to about 3% surfactant (w/w) and up to about 1% of a thickening agent (w/w).
[0012] The pharmaceutical composition of the invention comprises the following ingredients a) 0.1% poloxamer 188; b) 50% glycerin; c) 5% sorbitol crystalline; d) 5% propylene glycol; e) 0.065% disodium edetate; f) 0.2% sucralose; g) 0.44% carbomer; h) 0.04% butylparaben; and i) sodium hydroxide to a pH of between about 4.8 to about 5.2.
[0013] The inventive formulation may be used to treat a patient in need of an effective amount of the active pharmaceutical vehicle, prednisolone.
[0014] Among the medical conditions that may be treated by the formulation of the present invention are endocrine disorders, rheumatic disorders, collagen diseases, dermatologic diseases, allergic states, respiratory diseases, hemaologic disorders, neoplastic diseases, edema, gastrointestinal diseases or nervous diseases using an effective amount of the orally delivered prednisolone acetate composition.
DETAILED DESCRIPTION OF THE INVENTION
[0015] In describing embodiments of the present invention, specific terminology is employed for the sake of clarity. However, the invention is not intended to be limited to the specific terminology so selected. It is to be understood that each specific element includes all technical equivalents, which operate in a similar manner to accomplish a similar purpose. The above-described embodiments of the invention may be modified or varied, and elements added or omitted, without departing from the invention, as appreciated by those skilled in the art in light of the above teachings. Each reference cited herein is incorporated by reference as if each were individually incorporated by reference.
[0016] The formulation of the present invention is a palatable, oral formulation of prednisolone acetate. Prednisolone acetate has been used in ophthalmic and parenteral medicinal products, but has not previously been used in oral liquid preparations. Prednisolone acetate is practically insoluble in water. The low solubility presents a formulary challenge during product development of an aqueous liquid oral preparation. However, the use of the acetate form provides a taste advantage because the active does not dissolve in the aqueous environment of the mouth, and therefore prevents the interaction of the bitter-tasting molecules of the prednisolone with the taste buds.
[0017] The present invention is an aqueous suspension having a thickening component and a vehicle, or carrier, component and may include other pharmaceutically acceptable excipients. The vehicle is pharmaceutically acceptable, aqueous and suspension-stabilizing. Prednisolone acetate is evenly dispersed in the semi-solid aqueous vehicle. The suspension has a homogeneity so that the active ingredient is uniformly dispersed but undissovled in the vehicle. The formulation consists of mutually compatible components at room temperature. The suspension has a crystalline stability in that the prednisolone particles stay within a target particle size range over time.
[0018] The vehicle component serves as the external phase of the suspensions. The vehicle may be comprised of water, glycerin, propylene glycol and mixtures thereof. The vehicle component may contain glycerin up to about 50%. The vehicle may also comprise propylene glycol up to about 20% or from about 3% to about 10%. Purified water comprises the bulk of the vehicle component comprising from about 29% to about 64% of the formulation.
[0019] Purified water makes up the bulk of the vehicle component, comprising from about 29% to 64% (w/w) of the formulation. Water concentration can be less than about 50% (w/w) or even less than about 43% (w/w).
[0020] Thickening agents are pharmaceutically acceptable excipients that add a desired viscosity and flow to a formulation. Carbomers are synthetic high molecular weight polymers of acrylic acid. In one embodiment, carbomer 943P (Carbopol 974P) has been found to be a suitable thickening, or gelling agent, providing good sensory appeal and texture. The rheology of the carbomer provides for a high yield value, low shear thinning quality, in non-thixotropic liquid formulations.
[0021] The viscosity of the carbomer gel is pH dependent. Carbomer gels exhibit maximum viscosity at about pH 7.0. More acidic or basic pH's will cause the carbomer to lose viscosity. However, prednisolone acetate is most stable at slightly acidic pH's, and will degrade to undesirable breakdown products at the higher pH. At neutral pH's, prednisolone acetate will undergo oxidation and hydrolysis and form undesirable and less active degradation products. At a pH of 4.6 to 5.4, prednisolone acetate is stable in the formulation and the carbomer may retain its viscosity. The carbomer comprises up to about 1% (w/w) of the inventive formulation. In particular, we have found that the carbomer of the inventive formulation should be between about 0.40% to about 0.50%, more particularly, about 0.40% to about 0.48%.
[0022] The oral formulation of prednisolone acetate is a spill-resistant formulation. Spill resistant oral formulations are more extensively described in, for example, U.S. Pat. Nos. 6,071,253, and 6,102,254, herein incorporated by reference.
[0023] The pharmaceutical suspension comprising of the invention has prednisolone acetate uniformly dispersed in an aqueous vehicle, the active ingredient remaining in suspension without agitation during the product shelf-life. The shelf life may be up to about six, twelve, eighteen, twenty-four months, thirty months, or thirty-six months. The suspension has antimicrobial activity, is pharmaceutically effective and meets applicable regulatory requirements as would be understood by a person of ordinary skill. The viscosity may be about 5,000 to about 15,000 cps, about 5,000 to about 14,800 cps, about 9,000 to about 11,000 cps, or about 9,500 to about 10,500 cps. In inventive pharmaceutical suspensions there is no crystalline growth during a heat-cool study for three days at a temperature range of about 8° C. to about 45° C. The active ingredient particles may be crystals that neither dissolve or grow substantially when the sample is heated e.g. to 45° C. and cooled to room temperature repeatedly.
[0024] The formulation is dosed by volume, and specific gravity values were used to estimate the prednisolone acetate concentration in the composition. The 5 mg/mL dose was calculated, based on specific gravity to be 0.097% (w/w), which is equivalent to 0.087% (w/w) of the prednisolone base form. The 15 mg/mL dose was calculated to be about 0.293% (w/w), which is equivalent to 0.262% of prednisolone base form.
[0025] The particle size of the active pharmaceutical ingredient may have important effects on the bioavailability of a formulation. Smaller particle sizes have increased surface area and will dissolve faster than larger particles. However, decreasing the particle size may cause some agglomeration of the particles, and the increased surface area can result in faster degradation of the compound due to oxidation and hydrolysis. In the inventive formulation, a fine particle size was found to achieve the desired bioavailabilty. The prednisolone to acetate of the inventive formulation has a median particle size of approximately from about 1 μm to about 30 μm, more preferably about 5 μm to about 20 μm, most preferably from about 6 μm to about 8 μm. The particle size may be achieved using such methods air-jet milling, ball milling, mortar milling or any other method known in the art for decreasing particle size. For example, the prednisolone acetate particles of the disclosed formulation were micronized using a stainless steel, air-jet mill with a grinding chamber diameter of four inches (Sturtevant, Hanover, Mass., U.S.A., model no. SDM-4.)
[0026] The size of the particles may be measured using a light scattering device, sedimentation methods, centrifugal force measurements, or any method known to one skilled in the art. By means of an example, the Matersizer 2000 manufactured by Malvern Instruments, Ltd., Malvern U.K., may be used to measure the particle size.
[0027] Pharmaceutical excipients are pharmaceutically acceptable ingredients that are essential constituents of virtually all pharmaceutical products. Excipients serve many purposes in the formulation process. The inventive pharmaceutical suspensions may comprise at least one additional component selected from the group consisting of excipients, surface active agents, dispersing agents, sweetening agents, flavoring agents, coloring agents, preservatives, oily vehicles, solvents, suspending agents, dispersing agents, wetting agents, emulsifying agents, demulcents, buffers, salts, spreading agents, antioxidants, antibiotics, antifungal agents and stabilizing agents.
[0028] Spreading agents may be added to the vehicle component. Polyols, such as malitol, mannitol, polyethylene glycol and sorbitol may be added to the vehicle components to adjust the spreadability in the spoon bowl upon pouring. The present embodiment may contain sorbitol, in a concentration of less than 5%.
[0029] The suspensions of the present invention may also contain Edetate Disodium (EDTA). EDTA is a chelating agent that forms a stable water-soluble complex with alkaline earth and heavy metal ions. It is useful as an antioxidant synergist, sequestering metal ions that might otherwise catalyze autoxidation reactions. EDTA may also have synergistic effects as an antimicrobial when used in combination with other preservatives (Handbook of Pharmaceutical Excipients 4 th Ed.).
[0030] The suspension formulations may require a crystal conditioning surfactant, i.e. a wetting agent. The hydrophobic properties of prednisolone acetate may benefit from a wetting agent to disperse the steroid in the formulation. A concentration of from about 0.05% to about 0.5% poloxamer 188 was found to be effective at wetting the prednisolone acetate without excessive foaming and dispersion of the suspension.
[0031] The present formulation is an improvement over previously described prednisolone suspensions because the ingredient remains suspended indefinitely, without agitation; that is without stirring or shaking. The dispensed dose is always uniform over the shelf life of the product. The formulation of the invention can not be shaken easily, so the particles remain suspended without shaking.
[0032] The suspension has antimicrobial activity. Propylparaben (up to about 0.04%) and butylparaben (0.018% to about 0.18%) are suitable. Other antimicrobial excipients may also be used. These suspensions are alcohol-free.
[0033] The organoleptic ingredients improve the taste and appearance and do not negatively affect the suspension stability. The organoleptic agents in the following examples include coloring and flavoring agents, sweeteners and masking agents.
[0034] Mutual compatibility of the components means that the components do not separate in preparation and storage for up to the equivalent of two years at room temperature (as indicated by three month intervals of accelerated stability testing at 40° centigrade and at 75% relative humidity). Storage stability means that the materials do not lose their desirable properties during storage for the same period. Preferred compositions do not exhibit a drop in viscosity of more than 50% or an increase in viscosity of more than 100% during that period.
[0035] The following examples further illustrate the invention, but should not be construed as limiting the invention in any manner.
EXAMPLE 1
[0036] The prednisolone acetate oral suspension was formulated to contain the following ingredients:
TABLE I Composition of Oral Prednisolone Acetate Suspension 5 mg/5 mL INGREDIENTS (w/w %) 15 mg/mL Prednisolone Acetate 0.097 0.293 Poloxamer 188 0.1 0.1 Glycerin 50 50 Sorbitol Crystalline 5 5 Propylene Glycol 5 5 Edetate Disodium 0.065 0.065 Sucralose 0.2 0.2 Artificial Cherry Flavor 0.15 0.15 Bell Flavor Masking Agent 0.2 0.2 Carbomer 934 0.44 0.44 Butylparaben 0.04 0.04 Purified water to 100% to 100% NaOH pH 4.6-5.4 pH 4.6-5.4
EXAMPLE 2
Comparison of Different Prednisolone Actives for Sensory
[0037] Evaluation: A small sample of volunteers compared the different formulations of prednisolone for taste and flavor. Results are given in Table 2.
TABLE 2 Sensory Perception following different samples of Prednisolone Formulations Product Description Initial Taste After Taste Commercially Available Slightly sweet, Persistent, very bitter Prednisolone intense wild cherry 5 mg/5 ml Commercially Available Moderately sweet, Delayed moderately bitter Prednisolone sodium mild raspberry unpleasant taste persists for long phosphate time 5 mg./5 ml Taro Prednisolone Phosphate Pleasantly sweet, Delayed slightly bitter, Experimental Syrup 5 mg/5 mL cherry flavored Intensity increases with time Prednisolone Acetate Pleasantly sweet, No bitterness perceived Suspension 5 mg/mL cherry flavored
EXAMPLE 3
pH Screen Stability
[0038] Stability testing was performed on 1.0 kg portions of a 5.0 kg experimental batch of 5 mg/5 mL prednisolone acetate. NaOH was added to the portions to give various pH values (Batch A-E) and packaged in 4 ounce amber PETG bottles. The samples were left at the environmentally stressed conditions of 40° centigrade or 50° centigrade for one month. HPLC methods were used to measure the percent of prednisolone acetate retained in the bottle. The control sample used was a 5 mg/5 mL prednisolone acetate suspension exposed at room temperature and sampled after 4 months. The data is summarized in Table 3.
[0039] As demonstrated by the results shown in Table 3, in the pH range of 5.0 to 6.2, the micronized prednisolone acetate is more stable at the lower pH values.
TABLE 3 Stability of Prednisolone Acetate Oral Suspension (varying pH) Batch (%)Prednisolone (%)Prednisolone (%)Prednisolone No. pH Acetate 1 (RT) Acetate 1 (40° C.) Acetate 1 (50° C.) A 5.02 96.7 96.7 95.2 B 5.39 96.1 96.1 93.0 C 5.71 95.4 95.4 81.7 D 5.90 92.8 92.8 44.3 E 6.22 87.3 87.3 67.4
EXAMPLE 4
Suspension Dissolution
[0040] Dissolution tests are a qualitative tool that provides information about the biological availability of a drug formulation. Experimentally, suspension formulations are considered to disintegrate equivalently to tablet formulations, therefore dissolution testing is done comparing suspensions to tablets. A standard dissolution test (USP Apparatus 2 (paddle)) was followed to compare the prednisolone acetate suspension to a commercially available 5 mg tablet of prednicolone. As shown in FIG. 1, the dissolution curves of the suspensions were very similar to the dissolution curve for the tablet following a 15 minute period.
TABLE 4 Dissolution of Prednisolone Acetate Suspensions v. Prednisolone Tablets Prednisolone Acetate Prednisolone Suspension Tablets TIME 15 mg/5 ml 5 mg/5 ml 5 mg 5 48 45 69 15 85 82 93 30 95 93 96 45 97 95 98 60 97 96 98
EXAMPLE 5
[0041] Twenty three volunteers (male and female non- or ex-smokers) were orally administered a single 5 my dose of prednisolone in the morning after a ten hour overnight fast. The study design was a randomized, 6-sequence, 3-period, crossover design. Either 5 mL of a 5 mg/mL prednisolone acetate suspension, or one 5 mg tablet of a commercially available product, was administered. Blood samples were taken at determined intervals. Pharmacokinetic parameters used to evaluate and compare the relative bioavailability, and therefore bioequivalence, of the two formulations of prednisolone after a single oral dose administration under fasting conditions were C max , AUC T , AUC ∞ , K el and T 1/2el .
C max —Maximum Concentration. AUC T —Area under the Concentration-time Curve Using the Trapezoidal Method to the Last Measurable Concentration; AUC ∞ —Area under the Concentration-time Curve extrapolated to infinity; K el —Elimination Rate Constant; T 1/2el —Terminal Half-Life.
[0047] Bioequivalence was determined using the 90% confidence interval for the exponential of the difference between the tablet and the suspension. The test met the 80.00-125% confidence interval limits with a statistical power of at least 80%.
TABLE 5 Bioequivalency: Prednisolone 5 mg/5 mL Suspension versus 5 mg/5 mL Syrup versus 5 mg Tablets Following a 5 mg administration/Fasting State (100% prelims N = 23/23) Prednisolone 5 mg/ml Prednisolone 5 mg Suspension Tablet Coefficient Coefficient of of PARAMETER MEAN Variation MEAN Variation C max (ng/mL) 160.90 15.8 176.27 18.7 T max (hours) 1.33 41.6 1.00 33.2 AUC T (ng · h/mL) 821.73 20.2 812.39 17.7 AUC ∞ (ng · h/mL) 852.23 19.6 846.53 17.1 K el (hour −1 ) 0.2681 13.4 0.2629 9.7 T 1/2el (hours) 2.63 12.6 2.66 10.0 For Tmax, the median is presented.
[0048] In describing embodiments of the present invention, specific terminology is employed for the sake of clarity. However, the invention is not intended to be limited to the specific terminology so selected. It is to be understood that each specific element includes all technical equivalents, which operate in a similar manner to accomplish a similar purpose. The above-described embodiments of the invention may be modified or varied, and elements added or omitted, without departing from the invention, as appreciated by those skilled in the art in light of the above teachings. Each reference cited herein is incorporated by reference as if each were individually incorporated by reference. | The present invention relates to novel oral suspension formulation comprising prednisolone acetate, a pharmaceutically acceptable vehicle and a thickening agent. The present invention further provides a method of treating patients in need of prednisolone with the novel formulation. | 0 |
CROSS REFERENCE TO RELATED APPLICATIONS
[0001] This patent application claims priority to International Patent Application PCT/EP2011/006347, filed on Dec. 15, 2011, and thereby to German Patent Application 10 2010 054 540.6, filed on December, 2010.
STATEMENT REGARDING FEDERALLY SPONSORED RESEARCH OR DEVELOPMENT
[0002] No federal government funds were used in researching or developing this invention.
NAMES OF PARTIES TO A JOINT RESEARCH AGREEMENT
[0003] Not applicable.
SEQUENCE LISTING INCLUDED AND INCORPORATED BY REFERENCE HEREIN
[0004] Not applicable.
BACKGROUND
[0005] 1. Field of the Invention
[0006] The invention relates to a single circular knitting machine, consisting of a central rotatable needle cylinder (Z), around which a sinker ring (PR), which rotates simultaneously, comprising sinkers (P) as well as stationary cam systems (S), which act on the needles ( 1 ), which are in each case assigned to the sinkers (P) and which can be moved vertically up and down.
[0007] 2. Background of the Invention
[0008] The current state of knowledge is as follows.
[0009] Single circular knitting machines are an important branch in the use of knitting machines. Over decades, a structural design has thereby established itself, which has since not been questioned anymore. The basic elements of all of the single circular knitting machines, which are available today, are the central needle cylinder comprising the needle slots for the latch needles arranged on the periphery, of an invention from the year 1852. In response to the knitting loop formation process, the needles are moved back and forth by means of control bases, which stick out of the periphery, via control curves in sector cam systems, which are arranged side by side on the periphery. When pushing the latch needles forward, the last knitting loop, which is located in the hook, must open the latch and must overcome the increasing interior latch surface, so that it reaches the needle shaft behind the latch. A sinker ring, which is connected to the cylinder and which comprises sinkers arranged in horizontal slots, the pitch of which is staggered relative to the needles, ensures that the knitted fabric is thereby not lifted off the upper cylinder edge (=cast-off edge). The movements of the sinkers must be accurately coordinated with those of the needles. This is carried out in a laborious manner by means of a sinker cam plate, which is stationary in the space above the sinker ring and to which the sector-like sinker cams are fastened on the bottom, said sinker cams move the sinkers, which are also provided with control bases, back and forth when they are rotated past in operative connection with the needles. An adjusting possibility, which is not easily accessible, is thereby necessary in the sinker cams.
[0010] The enumeration makes it clear that many different courses of movement and functions take place simultaneously within a very small space of the knitting loop formation and that the stationary control systems, which are necessary for this, must be available. The demands on the accuracy have been increased extremely due to the needle pitches, which become finer and finer, so that fewer and fewer manufacturers can meet them, that is, a selection of only a few, who remain and who rule the market, is created. To alleviate the demands on accuracy, which meet in a confined space, the pitches of the cylinder and of the sinker ring, which meet directly, are particularly difficult.
BRIEF SUMMARY OF THE INVENTION
[0011] In a preferred embodiment, a single circular knitting machine consisting of a central rotatable needle cylinder (Z), around which a sinker ring (PR), comprising sinkers (P) as well as cam systems (S) are arranged, which act on the needles ( 1 ), which are in each case assigned to the sinkers (P) and which can be moved vertically up and down, characterized in that the sinkers (P) encompass a rocker ( 44 ) comprising an upper and a lower control bump ( 45 ) in each case on the end, which is spaced apart from the needle, that the sinker ring (PR) at the end below the sinkers (P), which is spaced apart from the needle, is embodied as a pivot point projection ( 40 ) comprising pivot point slits ( 41 ), in which the sinkers (P) are accommodated so that they are capable of being tilted with their pivot inlet ( 43 ) and in that they are laterally fixed in the needle gaps with sliding noses ( 47 ) at the end, which is spaced apart from the needle, such that the last knitting loops are transported to the needle shaft ( 1 ) behind the needle latches in response to the knitting loop formation.
[0012] In another preferred embodiment, the machine as disclosed, characterized in that the angle of inclination (a) of the sinker (P) and the x-y deflection of the sliding nose ( 47 ) are determined by means of the arrangement of the pivot point ( 42 ) of the sinker (P) at the outer diameter of the sinker ring (PR) with the distance dimensions (a, b) to the needle base and (c) to the cast-off edge of the cylinder (Z).
[0013] In another preferred embodiment, the machine as disclosed, characterized in that the sinker (P) encompasses a template ( 46 ) at the front, which transitions downwards into the sliding nose ( 47 ), for the insertion of the thread into the needle hook ( 2 ).
[0014] In another preferred embodiment, the machine as disclosed, characterized in that the sliding nose ( 47 ) of the sinker (P) can be controlled such that it clamps the last knitting loop on the upper edge of the needle slot side walls of the cylinder (Z) when the new thread loop is pulled through.
[0015] In another preferred embodiment, the machine as disclosed, characterized in that the sinker (P) forms the pivot point ( 42 ) in a pivot inlet ( 43 ) and is connected to a rocker ( 44 ), which is widened upwards and downwards, and the control bumps ( 45 ) of which on the end side encompass sliding surfaces for the pivot movement.
[0016] In another preferred embodiment, the machine as disclosed, characterized in that control cams ( 49 ), which are fastened in a support rail ( 48 ) on the cam system (S) as unit (E), are assigned to the control bumps ( 45 ) of the rocker ( 44 ), that the counterbalance ( 50 ) of the sinker (P) around the pivot point ( 42 ) is arranged between the control curves ( 49 ) and that the upper control cam ( 49 ) preferably includes mini slide or ball bearings.
[0017] In another preferred embodiment, the machine as disclosed, characterized in that the sinker ring (PR) encompasses an additional guide rim ( 51 ) comprising slits, which are laterally aligned with the pivot point slits ( 41 ), in the effective range of the lower control bump ( 45 ).
[0018] The machine according to one of claims 1 to 7 , characterized in that the sinker ring (PR), at its lower front surface, encompasses position slits ( 39 ), which are laterally aligned with the pivot point slits ( 41 ) and which can be inserted into the nose projections ( 38 ) at the cylinder insertion bars, which are known per se, whereby the pivot point slits ( 41 ) are oriented according to the needle gaps to a sufficiently accurate extent.
[0019] In another preferred embodiment, the machine as disclosed, characterized in that spacing bumps H or spacing springs or space maintainers are attached to the sinkers (P) above the cavity between needle cylinder (Z) and sinker ring (PR) such that they encompass the entire needle pitch at this location.
[0020] In another preferred embodiment, the machine as disclosed, characterized in that the space maintainer is embodied as a U-shaped slide.
[0021] In another preferred embodiment, the machine as disclosed, characterized in that the sinker shaft encompasses the full pitch distance above the cavity between needle cylinder (Z) and sinker ring (PR) and narrows laterally forwards for the engagement with the needle gaps, while lateral depressions, which form a guide latch ( 52 ) with the thickness of the pivot point slits ( 41 ), are preferably impressed in the back of the pivot inlet ( 43 ).
[0022] In another preferred embodiment, the machine as disclosed, characterized in that the sinker ring (PR) encompasses a plate area, which is embodied in particular so as to be flat.
[0023] In another preferred embodiment, the machine as disclosed, characterized in that the pivot point projection is embodied as an endless thread, which is arranged in a revolving groove, which is arranged in the outer periphery of the sinker ring.
[0024] In another preferred embodiment, the machine as disclosed, characterized in that the endless thread is made of rubber or highly elastic carbon or is embodied as a coil spring ring.
[0025] In another preferred embodiment, the machine as disclosed, characterized in that the thickness of the sinker (P) encompasses the full pitch distance at least at a distance to the end on the needle side.
[0026] A sinker for a single circular knitting machine, characterized in that the sinkers (P) encompass a rocker ( 44 ) comprising an upper and a lower control bump ( 45 ) in each case on the end, which is spaced apart from the needle, as well as a pivot inlet ( 43 ), wherein the thickness of the sinker (P) encompasses the full pitch distance at least at a distance to the end on the needle side.
[0027] In another preferred embodiment, the sinker as disclosed, characterized in that the sinker encompasses a spacing bump or a spacing spring or a space maintainer, which is preferably embodied as a U-shaped slide, at a distance to the end on the needle side.
[0028] In another preferred embodiment, the sinker as disclosed, characterized in that the sinker shaft narrow laterally forwards, starting at the distance to the end on the needle side, in which it encompasses the full pitch distance, for the engagement with the needle gaps, while lateral depressions, which form a guide latch ( 52 ) with the thickness of the pivot point slits ( 41 ), are preferably impressed in the back of the pivot inlet ( 43 ).
BRIEF DESCRIPTION OF THE DRAWINGS
[0029] FIG. 1 is a schematic diagram of a simplified design of a single circular knitting machine comprising novel grid sinkers (P), the geometric contexts of their embodiment, the automatic orientation of the sinker ring (PR) to the needle cylinder (Z) and the central structural unit of the machine with integrated control of all of the courses of movement.
[0030] Each of FIGS. 2 to 6 shows two different sinker alternatives for different fineness demands.
[0031] FIG. 2 shows the embodiment for average pitch fineness with the largest range of application.
[0032] FIG. 3 shows the embodiment for ultra-fine needle pitches with sinkers (P), which are stable for this purpose.
[0033] FIG. 4 shows the embodiment of the pivot point projection ( 40 ) according to the alternative of FIG. 3 .
[0034] FIG. 5 shows views of the sinker (P) with view from the left onto and from the right into the pivot inlet ( 43 ).
[0035] FIG. 6 shows the pivot point area of the sinker (P), which is introduced into the pivot point slit ( 41 ).
[0036] FIG. 7 shows the view from the top onto a formation of grid sinkers and onto the upper cylinder edge (Z).
[0037] FIG. 8 shows the partial section on the top through cylinder (Z) and sinker ring (PR) with exposed needle ( 1 ) and the sinker (P) in the lower end position.
[0038] FIG. 9 shows the arrangement according to FIG. 8 in the upper end position.
[0039] Each of FIGS. 10 to 14 shows the positions of the sliding nose ( 47 ) to the needle movement ( 1 ) in response to the formation of knitting loops.
[0040] FIG. 10 shows the cast-out position of the needle ( 1 ) with the sliding nose ( 47 ) being pivoted upwards for the insertion of the thread by means of the template ( 46 ).
[0041] FIG. 11 shows the insertion of the thread into the needle hook ( 2 ) in response to the return movement of the needle ( 1 ) and in response to simultaneous small downwards movement of the sliding nose ( 47 ).
[0042] FIG. 12 shows the clamping of the last knitting loop before pulling the new thread through on the upper edge of the needle cylinder with the sliding noses ( 47 ).
[0043] FIG. 13 shows the upwards movement of the sliding nose ( 43 ) into the capture position, so as to capture the new knitting loop, which hangs in the hook after the kinking in response to the forward movement of the needle ( 1 ) and, as can be seen in,
[0044] FIG. 14 , to bring it behind the open latch.
[0045] Each of FIG. 15 to FIG. 17 shows the difference of the knitting loop behavior according to the invention in response to the kinking.
[0046] FIG. 15 shows the knitting loop behavior in response to the current kinking
[0047] FIG. 16 shows the holding of the last knitting loop in response to the kinking.
[0048] FIG. 17 shows a possible advantageously small bevel of the upper edge of the needle cylinder in the area of the threading.
[0049] FIG. 18 shows the three-dimensional illustration of the central structural unit single circular knitting machine, consisting of needle cylinder sinker ring with grid sinker cam system with needle and sinker control.
[0050] FIG. 19 shows the exploded illustration of the components needle cylinder with needle and sinker ring—grid sinker—cam system for needle control—sinker control.
[0051] FIG. 20 shows the view from the front onto the simplified structural design single circular knitting machine with the combined cam system for the control of the needles and of the grid sinkers;
[0052] FIG. 21 shows the partial section on the top through cylinder (Z) and sinker ring (PR) with exposed needle ( 1 ) and the sinker (P) in the lower end position in an alternative embodiment of the invention.
[0053] FIG. 22 shows the arrangement according to FIG. 21 in the upper end position.
[0054] FIG. 23 a shows the three-dimensional illustration of the central structural unit of an alternative embodiment of a single circular knitting machine, consisting of needle cylinder, sinker ring and sinkers.
[0055] FIG. 23 b shows a sinker of the machine according to FIG. 23 a , which is arranged on the endless thread; and
[0056] FIG. 24 shows the view from the top onto a formation of grid sinkers and onto the upper cylinder edge (Z) of the alternative embodiment according to FIG. 23 a.
DETAILED DESCRIPTION OF THE INVENTION
[0057] The object of the invention characterized in claim 1 is to specify a single circular knitting machine, in the case of which the fixedly meeting pitches are replaced with a sinker grid system, which is flexible per se and which is oriented automatically in the needle gaps. The basic idea, which led to the invention, was to make the possible pitch accuracy in the needle cylinder to be the determining aspect for a more flexible allocation of the sinker in the functional area. The storage pitches of the sinkers could then be arranged further away on the sinker ring and the difficult taring of the tolerances of two pitches relative to one another, that is, the horizontal sinker slots would no longer be necessary. The connection of the sinker ring with the needle cylinder would be alleviated and would be possible without any problems. A more flexible sinker-grid formation is created in this manner from the storage to the needles in the cylinder. Different sinkers result, which are automatically oriented according to the needles when passing through in any system. Instead of the currently standard horizontal longitudinal movement, the sinkers are pivoted parallel to the needles. Advantageously, this has the result that, upon pushing the needles forward, the knitting loop is not only stopped, as has been the case until now, but is transported to the needle shaft in a more effective manner by means of a counter movement. In addition, the complicated sinker control by means of sinker cams, which are fixedly attached to a sinker cam plate above the rotating cylinder, becomes superfluous and the cam system takes over this task in a much more clearly arranged setup. The sinkers can furthermore be used as a template for inserting the thread into the needle hook, without having to additionally attach a thread guide. The current help from the take-up motion when casting off the old knitting loop by pushing it away by means of the sinker is replaced with a different measure. The described advantages have considerably simplifying effects on the overall design of the single circular knitting machine.
[0058] A basic idea of the invention is thus to equip the sinker ring with a plate area, which in particular does not encompass any sinker slots and which is thus substantially flat, so that the sinkers are arranged thereon so as to be movable relative to one another, wherein the sinkers are in particular supported only on the outer periphery of the sinker ring. The ends of the sinkers on the needle side can carry out movements transversally to their longitudinal axis, so as to align in the needle gaps. These transverse movements are thus not limited by the side walls of the sinker slots, which are known from the state of the art. In particular, the sinkers form a so-called sinker grid system, which is to be understood in the instant application as the plurality of sinkers, which are arranged on the sinker ring and which are in a detachable contact with one another at least at one point. The contact thereby preferably exists only in a lateral contact of adjacent sinkers, as is described below in more detail.
[0059] The invention can be used advantageously for all single circular knitting machine alternatives and considerably alleviates the demands on accuracy in the case of the ultra-fine needle pitches.
[0060] Advantageous further developments of the invention are specified in the subclaims.
[0061] The further development according to claim 2 relates to the geometric contexts in the determination of the pivot point of the sinkers (P) to the desired x-y movements of the sliding nose ( 47 ) in response to the knitting loop formation.
[0062] The further development according to claim 3 relates to the front design of the sinkers (P) for the thread insertion by means of a template ( 46 ) and of the sliding nose ( 47 ).
[0063] The further development according to claim 4 describes the possibility of the invention to hold the last knitting loop on the cast-off edge of the needle cylinder (Z) by means of the sliding nose ( 47 ) when pulling the new thread loop through.
[0064] The further development according to claim 5 relates to the design of the pivot inlet ( 43 ) of the sinkers (P) and to the embodiment of the rocker ( 44 ).
[0065] The further development according to claim 6 relates to the control of the sinkers (P) by means of the control curves ( 49 ), which are attached to a support rail ( 48 ) by means of the unit E.
[0066] The further development according to claim 7 relates to the embodiment of the sinker ring (PR) with additional guide slits for the rocker ( 44 ), which are available in the area of the control curve ( 49 ) so as to be aligned laterally with the pivot point slits ( 41 ) and also serves to stabilize the sinkers.
[0067] The further development according to claim 8 relates to the central connection of the needle cylinder (Z) to the sinker ring (PR).
[0068] The further development according to claim 9 relates to the embodiment of the sinker P as a composite element of a sinker-grid formation. For this purpose, spacing bumps H are preferably attached above the cavity between needle cylinder (Z) and sinker ring (PR) at the sinkers (P) so as to be capable of being released or spacing springs or other space maintainers, for example in the shape of U-shaped slides, such that they encompass the entire needle pitch at this location. The sinkers thus contact one another on the spacing bumps, spacing springs or space maintainers, so that the thickness of the sinkers at this location accounts for the entire needle pitch. The sinkers thereby form a sinker grid, which refers to the sinkers located next to one another, which are thus in particular not connected to one another so as not to be capable of being detached. The sinkers are in particular located next to one another in a circle of contact. A single one of these sinkers as component of this sinker grid can also be identified as grid sinker.
[0069] The further embodiment according to claim 11 relates to the stable embodiment of the sinkers (P) for the ultra-fine needle pitches. For this purpose, the sinker shaft preferably encompasses the full pitch distance above the cavity between needle cylinder (Z) and sinker ring (PR), and narrows laterally forwards for the engagement with the needle gaps, while lateral depressions, which form a guide latch ( 52 ) with the thickness of the pivot point slits ( 41 ), are preferably impressed in the back of the pivot inlet ( 43 ). It is thus possible for ultra-fine needle pitches to place the sinkers directly side by side, without providing for additional space maintainers, and to simply embody the area on the needle side to be narrower than the area, which is spaced apart from the needle.
[0070] According to a preferred embodiment, provision is made for the pivot point projection to be embodied as an endless thread, which is arranged in a revolving groove, which is arranged in the outer periphery of the sinker ring. An advantageous support of the sinkers can be attained through this.
[0071] Preferably, the endless thread is made of rubber or highly-elastic carbon or is embodied as a coil spring ring, which provides for a simple production.
[0072] A sinker according to the invention for a single circular knitting machine in each case encompasses at the end, which is spaced apart from the needle, a rocker ( 44 ) comprising an upper and a lower control bump ( 45 ) as well as a pivot inlet ( 43 ), wherein the thickness of the sinker (P) encompasses the full pitch distance at least at a distance to the end on the needle side. Through this, the sinkers are located laterally side by side at least at a distance when arranged in the machine and they are stabilized against one another, which makes it possible to use a flat plate area on the sinker ring instead of the otherwise common sinker rings comprising sinker slots, whereby the sinkers can be oriented according to the needle distances, because the transverse movements thereof are not limited by sinker slots.
[0073] According to a preferred embodiment of the invention, the sinker encompasses a spacing bump or a spacing spring or a space maintainer, which is preferably embodied as a U-shaped slide, at a distance to the end on the needle side. Through this, it is made possible to determine the desired pitch space in a simple manner.
[0074] According to an advantageous embodiment, the sinker shaft narrows laterally forwards, starting at the distance to the end on the needle side, in which it encompasses the full pitch distance, for the engagement with the needle gaps, while lateral depressions, which form a guide latch ( 52 ) with the thickness of the pivot point slits ( 41 ), are preferably impressed in the back of the pivot inlet ( 43 ). Such sinkers can be produced in a simple manner.
[0075] Exemplary embodiments of the invention will be defined by means of FIG. 1 to FIG. 24 . Unless otherwise specified, all of them are embodied in an enlarged scale of approx. 5:1. The direction of rotation of the cylinder (Z) and of the sinker ring (PR) is thereby clockwise.
DETAILED DESCRIPTION OF THE FIGURES
[0076] Referring now to the figures, The first housing, according to FIGS. 1 and 3 (e.g. a motor housing for holding an electric motor) is connected to a second housing, according to FIGS. 1 , 2 and 3 designed as a modular transmission housing 2 , according to the connection structure of the invention.
[0077] The motor housing 1 is designed with a cylindrical shape and on the output side has a bearing plate with a cylindrical flange 7 , in which the output shaft 9 of the electric motor is mounted.
[0078] The transmission housing 2 holds a planetary gear and comprises a motor flange 2 a with which the motor housing 1 is connected. In addition, the transmission housing has two gear stages 2 b and 2 c , each of which comprises an annular ring with sun gear, planetary gears and planetary carrier (not shown in the figures). The closure on the output side of the transmission housing 2 forms an output flange 2 d with an output shaft 10 .
[0079] For connecting the motor housing 1 with the transmission housing 2 , the motor flange 2 a is equipped with a hollow cylindrical recess 3 , which is formed of a circular collar 4 on the drive side of the transmission housing 2 . The inner diameter of the hollow cylindrical recess 3 formed by this collar 4 corresponds to the outer diameter of the motor housing 1 in the area of its bearing plate with the cylindrical flange 7 . This hollow cylindrical recess 3 also has a central pocket hole 3 a , the inner diameter of which corresponds to the outer diameter of the cylindrical flange 7 of the motor housing 1 .
[0080] As the cross section representation according to FIG. 3 shows, the motor housing 1 is inserted with its cylindrical flange into the recess 3 , whereby the flange 7 is held by the pocket hole 3 a for centering the transmission housing 1 . The face side 11 surface of the motor housing 1 lies flush on the recess base 12 of the recess 3 .
[0081] For axial and radial fixing and securing of the transmission housing 2 on the motor housing 1 , the transmission flange 2 a has two radially-running threaded screws 5 as tensioning elements in the area of the collar 4 , which are each screwed into a diametrically opposed threaded hole 13 , until they each engage in an engagement groove 6 on the lateral surface of the motor housing 1 and because of this the transmission housing 2 is tensioned against the motor housing 1 .
[0082] The motor flange 2 a is equipped with a drive shaft 8 in a ball bearing, which is in active connection as a four-cornered shaft with the output shaft 9 of the motor housing 1 , whereby this output shaft 9 has a hollow shaft profile with recessed square.
[0083] Naturally, the invention is not restricted to this active connection that is explained, rather any other suitable active connection can be provided between the output shaft 9 of the motor housing 1 and the drive shaft of the transmission housing 2 , e.g. a usual motor-side output shaft with motor pinion pressed on.
[0084] According to FIG. 3 , the drive shaft 8 of the motor flange 2 a is connected to a sun gear 14 of the gear stage 2 b mounted on the motor flange 2 a by means of a threaded connection 15 .
[0085] Finally, a tensioning element different from the threaded pins 5 shown in the exemplary embodiment can also be used; e.g. the use of a snap ring is also suitable.
LIST OF REFERENCE NUMBERS
[0000]
1 needle
2 needle hook
3 needle breast
4 needle slit
37 guide bulge on the sinker ring
38 nose projection on the cylinder insert bar
39 position slits at the lower front surface of the PR
40 pivot point projection on the outside of the PR outer diameter
41 pivot point slits on the sinker ring
42 pivot point in the projection on the PR
43 pivot inlet of the sinker
44 rocker of the sinker with control bumps on both ends for the pivot movement
45 control bump
46 template for the thread feed into the needle hook
47 sliding nose for knitting loop transport to needle shaft
48 support rail for sinker control unit
49 control curve
50 counterbalance of the sinker P between the control curves
51 guide rim
52 guide latch
54 peripheral groove
55 slide
56 endless thread
e cavity between cylinder and PR for latch movement
S upper part cam system (rope)
P sinker
PR plate ring
Z needle cylinder
[0114] The references recited herein are incorporated herein in their entirety, particularly as they relate to teaching the level of ordinary skill in this art and for any disclosure necessary for the commoner understanding of the subject matter of the claimed invention. It will be clear to a person of ordinary skill in the art that the above embodiments may be altered or that insubstantial changes may be made without departing from the scope of the invention. Accordingly, the scope of the invention is determined by the scope of the following claims and their equitable Equivalents. | In the case of a single circular knitting machine consisting of a central rotatable needle cylinder (Z), around which a sinker ring (PR) comprising sinkers (P) as well as stationary cam systems (S) are arranged, which act on the needles ( 1 ), which are in each case assigned to the sinkers (P) and which can be moved vertically up and down, so as to replace the pitches, which hit one another rigidly, with a sinker grid system, which is flexible per se, which is automatically oriented in the needle gaps, a rocker ( 44 ) comprising an upper and a lower control bump ( 45 ) being provided in each case on the end of the sinkers (P), which is spaced apart from the needle, the sinker ring (PR), at the end below the sinkers (P), which is spaced apart from the needle, is embodied as a pivot point projection ( 40 ) comprising pivot point slits ( 41 ), in which the sinkers (P) are accommodated with their pivot inlet ( 43 ) so that they are capable of being tilted and the sinkers (P) being are laterally fixed in the needle gaps with sliding noses ( 47 ) at the end, which is spaced apart from the needle, transport the last knitting loops to the needle shaft ( 1 ) behind the needle latches in response to the knitting loop formation. | 3 |
BACKGROUND OF THE INVENTION
[0001] 1. Field of the Invention
[0002] Applicant's invention relates to a purified natural zeolite pigment that can be used as a microparticle retention aid that produces a paper that exhibits improved characteristics over existing papers made with other retention aids.
[0003] 2. Background Information
[0004] Paper is a complex composite made up of a combination of biological, synthetic, and inorganic materials. The components include wood pulp or other fibers and fines (as well as other components of wood), inorganic (mineral) and organic fillers, natural and synthetic polymers (for sizing, retention and strength), and other additives to meet specific product or process requirements. Retention of the individual components in appropriate amounts is critical to the properties and quality of the paper sheet as well as minimizing pollution and cost.
[0005] Retention has been defined in the literature as the term used to describe the effectiveness of a given process to retain the components of the paper sheet or to describe the ability of a given material to be retained. 1 Retention describes the amount of a given material in the final product relative to the amount present at some earlier stage in the process. 1 Scott, W. E., Principles of Wet End Chemistry TAPPI Press: Atlanta (1996), p. 111.
[0006] In the past decade, retention has gained even more importance due to many changes in the paper industry. Paper machines have become bigger and run faster. Most fine paper mills have converted to alkaline papermaking conditions. This has permitted the use of new and less expensive filler systems, predominately calcium carbonate in some form (precipitated, ground, or chalk). In addition to a cost advantage, these fillers impart properties needed to meet more stringent product requirements. For example, very often the same sheet is expected to be suitable for both ink-jet printing and xerography. Generally the filler content of the sheet has increased and is likely to continue to increase. The switch to alkaline papermaking conditions has also resulted in a change in sizing chemistries. Synthetic sizes such as ASA (alkenyl succinic anhydride) and AKD (alkyl ketene dimer) are the predominant sizes used in alkaline papermaking. 2 How they interact with other components of the sheet and how and where they are retained is critical to the properties of the sheet. There are now trends toward neutral or alkaline conditions and increased filler usage in wood containing grades also. AS paper manufacturers recognize the costs of poor retention in terms of pollution abatement and product loss, they are striving to reduce or eliminate effluents from their mills. All these factors combine to make retention of papermaking materials one of the most important processes of the wet end operation. 3 2 Gess, J. M., Tappi Journal 75 (4): 80 (1992). 3 Doiron, B. E., 1994 TAPPI Papermakers Conference Proceedings , TAPPI Press: Atlanta (1994), p. 603.
[0007] Retention of the various components of the stock in the final sheet is generally considered to be due to chemical, mechanical, or a combination of both mechanisms. While the dissolved materials are retained by adsorption or chemical bonding to the suspended solids, the suspended solids are retained by mechanical filtration or entrapment with the forming web of fiber, or preferably by physico-chemical attachment to the fibers, which are much larger, or to one another. This will occur to some degree regardless of attractive or repulsive forces between the particles. Because of their relatively small size, the particles which make up the fines fraction (inorganic fillers and cellulosic fines) are difficult to retain in the web, and much more of this material would pass through the wire and end up in the white water system if it were not for the addition of retention aids which enhance the colloidal retention of the fines fraction. Retention aids are water-soluble polyelectrolytes which cause the fines fraction to flocculate either with themselves or by adsorption onto the long fiber portion of the furnish, thus bringing about greater retention by both chemical and mechanical means.
[0008] Theory says there are two ways in which the fine particles in a papermaking web can be retained through physicochemical mechanisms:
1. By gathering the fine particles into a macroparticle. 2. By attaching the fine particles to the large fibers that are in turn retained at a 100% level.
[0011] As a rule, agglomeration, flocculation or coagulation is accomplished by changing the charge of one particle in relation to another. This is done by adding a high cationic charge density, low molecular weight polymer (in the case of an acid papermaking system) to a papermaking furnish. It is expected that the fiber fines and small filler particles, because of their higher surface area in comparison to fibers, interact preferentially with the polymers. The high charge density of these polymers will cause the formation of cationic spots on the filler particles and fiber fines. It then is hypothesized that the cationic centers on the filler particles and fiber fines will be attracted to the anionic centers on the fibers, and this will result in the retention of the fines and small filler particles with the fibers. Too high of a dose of agglomerant or coagulant will result in fiber-fiber repulsion and a loss in retention.
[0012] The terms agglomeration, flocculation and coagulation are often used interchangeably in papermaking. Agglomeration or flocculation was used by those working directly with paper machine personnel, while coagulation was used by those personnel working in water treatment. Agglomeration or flocculation is that interaction that occurs between oppositely charged materials. Coagulation, on a purely theoretical level, tends to be formation of macroparticles that occurs when the zeta potential of a system approaches zero and there is a maximum physicochemical interaction between the elements of the furnish.
[0013] Microparticle retention systems are considered to influence fine particle retention through a physicochemical mechanism of coagulation. Such a mechanism has long been thought to have the greatest impact on small particle retention. 4 4 Unbehend, J. E, Tappi 59 (10): 74 (1976).
[0014] Modern microparticle systems include both soluble polyelectrolytes and a very small (5-10 nm) highly charged “microparticle” to destabilize a given colloidal particle suspension through a complex mechanism. Usually inorganic in nature, these particles typically possess a large anionic surface charge. Used in combination with soluble polyelectrolytes, such as cationic starch or polyacrylamides, wither cationic or anionic, microparticle retention systems provide a very powerful tool for optimizing retention.
[0015] Colloidal silica is the predominant microparticle used in papermaking retention systems today. The original colloidal silica micro particle introduced to the paper industry was a stable colloidal dispersion of spherical amorphous silica particles, about 5 nm in size. 5 A variety of particle sizes and three-dimensional silica sol structures have been presented in the last ten years. 6 Some of the three-dimensional silica aggregate structures have overall aggregate size small enough (20-50 nm) to maintain the colloidal dispersion properties of the individual silica particle. 5, 7 5 Sunden, O., Batelson, P. G., Johansson, H. E., Larsson, H. M., and Svenging, P. J., U.S. Pat. No. 4,388,150 (Jun. 14, 1983). 6 Johansson, H., International Patent WO 95/23021 (Aug. 31, 1995). 7 Moffett, R. H., Tappi Journal 77 (12): 133 (1994).
[0016] One of the silica aggregates has been developed specifically to work with high-charged cationic polyacrylamide. This product is a highly branched, three-dimensional, silica aggregate with an overall particle size of approximately 50-nm. 7 Moffett reported that the highly structured, larger sized silica aggregates appear to be the most efficient silica particles used in conjunction with a wide range of cationic polyacrylamides. 7
[0017] It can be seen that one of the shortcomings of silica microparticle systems is the need to use different physical structures for the various papermaking applications. Another limitation on the use of silica microparticle retention aids is their very high cost.
[0018] Colloidal bentonite clay with a high smectite component, specifically montmorillonite, is another mineral commonly used in microparticle retention systems. The attribute similar to the silica microparticles is the high surface area and high charge on the particle, which, in combination, promotes the coagulation mechanism of retention of small fillers and fines. Colloidal bentonites that are effective in microparticle systems are three-dimensional particles that are up to 300 nm long and have a very thin, uniform thickness of less than 1 nm. 8 High purity montmorillonite is critical for using colloidal bentonites as a microparticle in retention systems. 8 8 Kundson, M. I., 1993 TAPPI Papermakers Conference Proceedings , TAPPI Press: Atlanta, 1993, p. 141.
[0019] Other types of inorganic microparticle retention systems have been presented in the literature. 9,10,11 The filler retention performance of the system based on aluminum hydroxide in-situ in conjunction with cationic starch is close to that of silica and bentonite-based microparticle systems. From an economic standpoint, the level of cationic starch needed results in an expensive system and can result in paper quality problems, such as poor sheet formation. Additionally, because of the unique pH-dependent distribution of alumina species, fines retention is very dependent upon pH. While good retention performance can be obtained in a pH range from 7.8-8.6, a pH drop to only 7.5 can result in a 25% reduction in fines retention. 12 9 Bixler, H. J. and Peats, S., U.S. Pat. No. 5,071,512 (Dec. 10, 1990) 10 Jokinen, O. J. Petander, L. and Virta, P. J., U.S. Pat. No. 4,756,801 (Jul. 12, 1988). 11 Gill, R. A. and Sanders, U.S. Pat. No. 4,892,590 (Jan. 9, 1990). 12 Gill, R. I. S., Paper Tech., 32(8): 34 (1991).
[0020] Existing microparticulate retention aids, namely silica and bentonite, have many disadvantages, so a goal of the present invention was to develop a microparticle retention system that incorporates a zeolite pigment with at least the same or superior qualities to those of the existing microparticles.
[0021] A zeolite pigment that possesses the desirable combination of brightness, color, particle size distribution, surface area, internal void volume, rheology and hardness could also be useful in overcoming the limitations of conventional and other specialty pigments in various papermaking and paper coating applications including but not limited to: (1) more economical microparticle retention system chemistry; (2) toner bond improvement in laser and other dry toner imaged digital papers; (3) elimination of smudging and improvement of print quality in direct print flexography on coated linerboard used in corrugated containers; (4) elimination of print through on newsprint and ultra light weight coated papers; (5) improvement of dot fidelity and print quality on coated rotogravure printing papers; (6) low abrasion extender for titanium dioxide pigments; (7) improvement of coefficient of friction of paper and paperboard; (8) production of technical specialty papers such as anti-tarnish, gas filtration, and absorbent papers with improved properties and lower cost of manufacture; (9) additive to improve the efficiency of deinking systems; (10) additive to reduce problems with pitch, stickies and/or other organic deposits in pulping and papermaking systems.
[0022] Zeolites are crystalline, hydrated aluminosilicates of the alkali and alkaline earth metals. More particularly, zeolites are framework silicates consisting of interlocking tetrahedrons of SiO 4 and AlO 4 . In order to constitute a zeolite, the ratio of silicon and aluminum to oxygen must be 2. The aluminosilicates structure is negatively charged and attracts the positive cations that reside within. When exposed to higher charged ions of a new element, zeolites will exchange the lower charged element contained within the zeolite for a higher charged element. Unlike most other tectosilicates, zeolites have large vacant spaces or cages in their structures that allow space for large cations such as sodium, potassium, barium, and calcium and relatively large molecules and cationic molecules, such as water, ammonia, carbonate ions, and nitrate ions. In most useful zeolites, the spaces are interconnected and form long wide channels of varying sizes depending on the mineral. These channels allow ease of movement of the resident ions and 19 molecules into and out of the structure.
[0023] Zeolites are characterized by 1) a high degree of hydration, 2) low density and large void volume when dehydrated, 3) stability of the crystal structure of many zeolites when dehydrated, 4) uniform molecular sized channels in the dehydrated crystals, 5) ability to absorb gases and vapors, 6) catalytic properties, and 7) cation exchange properties.
[0024] There are several mentions of the use of synthetic zeolites as a wet end additive in papermaking. In U.S. Pat. No. 4,752,314 Rock teaches the use of a combination of titanium dioxide and synthetic Zeolite A wherein the sodium has been at least partially replaced with calcium and/or hydronium ion to improve the optical properties of paper. Rock teaches that the Zeolite A must have a composition: Zeolite (Ca.sub.x Na.sub.y)A zH.sub.2 O where x is in the range of 0.3 to 3.6, y is in the range of 9.6 to 11.85 and z is in the range of 20 to 27 or Zeolite (Ca.sub.x Na.sub.y Hy) zH.sub.2 O where x is in the range of 0 to 4.8, y is in the range of 0.6 and z is in the range of 20 to 27.
[0025] In U.S. Pat. No. 5,900,116 Nagan teaches the use of a synthetic zeolite crystalloid coagulant with particle size 4 to 10 nm in combination with cationic acrylamide polymer as a papermaking retention aid.
[0026] The use of natural zeolites in paper making has a long history, but has been almost unique to Japan where zeolite has been used as filler to improve bulkiness and printability. 13 Natural zeolites have also been used as fillers for paper in Hungary. These natural zeolites however are a low brightness material and this renders it unsatisfactory for application in the United States on uncoated office paper and on coated ink jet paper where high brightness is expected. 13 Japanese patent application No. 45-41044 with disclosure date Dec. 23, 1970.
[0027] Numerous families of natural zeolites exist and each has varying characteristics. Unfortunately, natural zeolites exhibit nonuniform properties that make them difficult to work with in many applications because ores from one location can vary with any other. It is however possible to manufacture zeolites with uniform properties. The preferred zeolite for use in the present invention is a processed form of the natural mineral clinoptilolite which is a hydrated sodium potassium calcium aluminum silicate having the formula (Na, K, Ca) 2-3 Al 3 (Al,Si) 2 Si 13 ) 36 —12H 2 O. This zeolite is within the family Heulandite that also includes the mineral heulandite, which is a hydrated sodium calcium aluminum silicate. The physical characteristics of raw clinoptilolite are listed in Table 2.
TABLE 2 PHYSICAL CHARACTERISTICS OF CLINOPTILOLITE Color is colorless, white, pink, yellow, reddish and pale brown. Luster is vitreous to pearly on the most prominent pinacoid face and on cleavage surfaces. Transparency: Crystals are transparent to translucent. Crystal System is monoclinic; 2/m. Crystal Habits include blocky or tabular crystals with good monoclinic crystal form. More tabular and proportioned than heulandite. Also commonly found in acicular (needle thin) crystal sprays. Cleavage is perfect in one direction parallel to the prominent pinacoid face. Fracture is uneven. Hardness is 3.5 B 4, maybe softer on cleavage surfaces. Specific Gravity is approximately 2.2 Streak is white.
[0028] Clinoptilolite's structure is sheet like with a tectosilicate structure where every oxygen is connected to either a silicon or an aluminum ion (at a ratio of [Al+Si]/0=2). The sheets are connected to each other by a few bonds that are relatively widely separated from each other. The sheets contain open rings of alternating eight and ten sides. These rings stack together from sheet to sheet to form channels throughout the crystal structure. The size of these channels controls the size of the molecules or ions that can pass through them. Clinoptilolite is well suited for various applications, such as in paper coating compositions, because it exhibits large pore space, high resistance to extreme temperatures, and has a chemically neutral structure.
[0029] The zeolite of the present invention is not anticipated by either Rock in U.S. Pat. No. 4,752,341 or Nagan in U.S. Pat. No. 5,900,116. The structure of the natural zeolite of the present invention falls outside of the range of structures specified by Rock in U.S. Pat. No. 4,752,341. The particle sizes of the natural zeolite of the present invention are 2 to 3 orders of magnitude greater than the 4 to 10 nm specified by Nagan in U.S. Pat. No. 5,900,116.
SUMMARY OF THE INVENTION
[0030] An object of the present invention is to provide a novel purified natural zeolite pigment that can be used as a microparticle in a retention aid system.
[0031] Another object of the present invention is to provide a novel purified natural zeolite that can be used as a catalyst in chemical processes.
[0032] In satisfaction of these and related objectives, Applicant's present invention provides a purified natural zeolite pigment that can be used as a microparticle for a retention aid system. Applicant's invention permits its practitioner to manufacture paper that exhibits improved characteristics over existing papers such as high print quality images and reduced cost. It also permits the practitioner to make other specialty and technical papers that exhibit quality and economic advantages over papers made with existing technology and commercially available materials.
BRIEF DESCRIPTION OF THE DRAWINGS
[0033] FIG. 1 is a graph of Britt Jar™ speed versus % filler retention for ZO Brite-1, ZO Brite-3 and silica.
[0034] FIG. 2 is a graph of Britt Jar™ speed versus % filler retention for ZO Brite-1 and ZO Brite-1 new.
[0035] FIG. 3 is a graph of Britt Jar™ speed versus % filler retention for bentonite, ZO Brite-1 and ZO-Brite-3.
[0036] FIG. 4 is a graph of Britt Jar™ speed versus % filler retention for ZO Brite-1, ZO Brite-Select and silica.
DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENT
[0037] The processed zeolite used in the present invention has several specific characteristics as indicated in Table 3.
TABLE 3 Characteristics of Zeolite Pigment Samples Zeolite Pigment Zeolite Pigment Specification Sample 1 Sample 2 GE Brightness 14 % 94+ 90+ L 15 98.46 98.00 a 0.43 0.44 b 1.25 1.72 Yellowness Index 2.48 2.05 Particle Size μ, <D90 2.0 2.0 Einlehner Abrasion, mg loss 12 18 Loose Density, lbs./cu.ft. 8 8 Packed Density, lbs./cu.ft. 12 12 Refractive Index 1.48 1.48 Surface Area, sq.m./g. 40-50 40-50 Oil Absorption, lbs./100 lbs. 70-80 70-80 Density, g/cc 2.2 2.2 r pH in Water 5.0 8.5 Cation Exchange Capacity 1.6-1.8 1.8-2.0 Brookfield Viscosity, 20 rpm 1000 cPs 1000 cPs @ 40% solids* Hercules Viscosity 1 dyne 1 dyne @ 1100 rpm* 14 GE Brightness is a directional brightness measurement utilizing essentially parallel beams of light with a wavelength of 457 nm to illuminate the paper surface at an angle of 45°. It is also referred to as TAPPI Brightness. GE or TAPPI Brightness is the value obtained by TAPPI Test method T646 om-94 “Brightness of Clay and Other Mineral Pigments” (45 degrees/0 degrees). *Nonoptimized dispersion in water 15 L, a, b values are the chromacity coordinates or color values of paper or paperboard measures with tristimulus filter colorimeters or spectrophotometers incorporating direction (45°/0°) geometry and CIE (International Commission on Illumination) illuminant C. “L” represents lightness, increasing from zero for black to 100 for white; “a” represents redness when plus, greenness # when minus and zero for gray; “b” represents yellowness when plus, blueness when minus, and zero for gray. This is referred to as TAPPI Test Method T 524 om-94 “Color of Paper and Paperboard (45°/0° Geometry).”
[0038] Pilot paper machine trials were run comparing the use of the zeolite of the present invention to precipitated calcium carbonate (PCC) as filler. The trials showed significant advantages of the present zeolite pigment as filler. These pilot machine filler trials were run without use of retention aid polymers. It was found that the filler retention for the present zeolite was 2.5 to 4 times as high as PCC, which facilitates running a cleaner wet end with improved sheet formation and uniform optical properties. The significantly higher retention achieved with the zeolite of the present invention is an indication that it can perform well as a substitute for silica or bentonite in microparticulate retention systems. Silicas currently used in this application are not cost effective. The improved retention of the zeolite pigment is an indication that it would be useful as an alternative to costly silica as a deinking aid.
[0039] In addition, porosity tests showed that the present zeolite produced a more open sheet, which would facilitate the use of this pigment in specialty gas filtration papers and anti-tarnish papers. It was also found that the zeolite pigment of the present invention produced papers that had higher tensile strength and tensile energy absorption or stretch. Papers filled with the present zeolite also had a higher coefficient of friction, which decreases the likelihood of misfeed and jams in copiers and also improves performance in converting equipment and print shops. The zeolite of the present invention can also be useful as a frictionizer for coefficient of friction control in recycled linerboard.
[0040] The capability of the zeolite pigment to reduce print-through was evaluated by printing samples from the pilot paper machine trials on a proof press and visually inspecting them for evidence of print show-through. The control sample with no filler showed severe print-through. The sample filled with 100 pounds of zeolite pigment (4.59% measured ash content) showed no evidence of print-through. Samples filled with PCC at levels up to 250 pounds per ton showed little improvement over the unfilled control with regard to print-through. The superior performance of the zeolite pigment in minimizing print-through is an indication that it would be useful in production of ultra lightweight-coated publication papers.
[0000] Microparticle Retention Systems
[0041] EKA's Compozil™ system using colloidal silica has become a standard against which other microparticulate retention systems are measured for highly-filled papermaking systems. Another very popular microparticle system in use is Ciba's Hydrocol™ system utilizing bentonite as the mineral microparticle. While there are other (colloidal polymer) microparticle systems in use, silica and bentonite dominate the mineral pigment sector of these systems.
[0042] Many laboratory devices and test methods have been developed in order to enable the investigator to evaluate pulps, retention aids, fillers, and other additives without resorting to a trial on a full-size paper machine. These include modifications of devices used to measure freeness and handsheet making equipment as well as devices designed specifically to measure retention.
[0043] Standard handsheet making equipment such as a British hand sheet mold equipped with a means of re-circulating white water can prove useful in laboratory studies. The advantage, in addition to being fast and simple, is that the resulting handsheets can also be tested. However, these are static methods and do not simulate the turbulence and shear forces that the furnish would be subjected to on a paper machine.
[0044] The Dynamic Drainage Jar developed by Britt and Unbehend attempts to simulate conditions encountered on a paper machine. 16 The device determines the relative tendency of the fines fraction to pass through the screen with the fluid phase or to remain adsorbed as a part of the solid phase. The result is expressed as retention of the fines fraction under selected and controlled turbulence conditions. 16 Li, H. M., and Scott, W. E, 2000 TAPPI Papermakers Conference Proceedings , TAPPI Press: Atlanta (2000), p. 1.
[0045] Because it is not possible to duplicate the performance of a paper machine in an experimental device without in effect building an experimental paper machine with all the complexity of a real paper machine, Britt and Unbehend argue that a laboratory device which measures the relative tendency of the fines fraction to be retained or to follow the water over a range of turbulence would be useful in evaluating retention for a wide range of machines. This is what the Dynamic Drainage Jar was designed to do, and it has been accepted as the industry standard throughout the world.
[0046] Because of the wide range of papermaking furnish combinations in commercial practice, our focus in this study was to identify a model system that would generate the most useful information for the intended initial screening. Value-adding pigments are most often found to be used in significant quantities in bleached free sheet furnishes, rather than in wood-containing (newsprint or magazine) or unbleached chemical (corrugated container) pulp systems. To that end, a general furnish of bleached northern kraft pulp was chosen, with a 60% hardwood (HW), 40% softwood (SW) blend refined to a Canadian Standard Freeness 17 of approximately 420 ml. 17 Canadian Standard Freeness is a measure of how much water a given papermaking pulp suspension will ‘hold’ under simple gravity. It is designed to give a measure of how easily a dilute suspension of pulp (3 grams in 1 Liter of water) may be drained. This is important in the papermaking process because it influences the amount of power needed to run the machine and ultimately the speed at which the machine may operate.
[0047] There are several important paper properties that are developed or enhanced by the addition of pigments (fillers), but the first challenge of papermaking is to keep the added pigments in the sheet during web formation and consolidation 18 from a suspension that is more than 99% water. This challenge is most often called “filler retention.” The classical method for evaluating filler retention potential is by the use of a dynamic drainage device, typically called a Britt Jar™. This screening evaluation was conducted using a Britt Jar™ at several internal propeller speeds to simulate paper machines running over a wide range of line speeds. 18 Web formation is defined as creating a loosely combined sheet structure, typically with fibers or filaments, which are consolidated (bonded) through any number of web methods. Web formation processes include spun bonded and spun melt composites, melt blown, carded, wet laid, air laid and porous film. Web consolidation processes include thermal bonded, resin or chemical product, spunlaced or hydroentangled, thru-air bonded, needle punched, and stitchbonded.
[0048] Pigments involved in this study were scalenohedral 19 precipitated calcium carbonate (PCC), the zeolite of the present invention, bentonite, and colloidal silica. The overall purpose of this study was to evaluate the zeolite of the present invention as a potential filler to a papermaking furnish and to evaluate the zeolite of the present invention as a potential contributor to a microparticle retention system in a rather highly-filled papermaking furnish. Specifically concerning the microparticulate retention system, the present inventors wanted to determine (1) if the zeolite of the present invention had the potential to replace colloidal silica or bentonite and (2) if so, is there any significant difference in performance among the different grades of zeolite of the present invention when used to replace the colloidal silica and bentonite. In order to determine the potential of the zeolite pigment of the present invention as a filler and in a microparticulate retention system, several zeolite pigment samples were used. The samples were designated as ZO Brite-1, ZO Brite-1 new, ZO Brite-select and ZO Brite-3 and their characteristics are listed in Table 3. 19 A scalenohedron is a six-sided polyhedron, similar to a bipyramidal hexagon, but the adjoining area at the center is diagonal between every side as opposed to being level. Other modifications might also be present.
TABLE 3 Specifications for ZO Brite-1, ZO Brite-1 new, ZO Brite-3, and ZO Brite-select samples Specifications ZO Brite-1 ZO Brite-1 new ZO Brite-3 ZO Brite - select GE Brightness 92+ 94+ 90+ 90+ L 97 98 96 96 a −0.1 −0.3 0.44 0.33 b 1.45 1 1.72 1.72 YI Yellowness 2.25 2 2.5 2.5 Index Particle Size 2 2 2 0.5 u < D90 Einlehner 12 12 18 18 Abrasion Loose Density 4 to 8 4 to 8 4 to 8 0.1-0.2 (lbs/cu.ft) Packed 12 to 16 12 to 16 12 to 16 2-4 Density (lbs/cu.ft) Refractive 1.48 1.48 1.48 1.48 Index Surface Area 40 to 50 40 to 50 40 to 50 2400-3200 (sq.m./g) Oil Absorption 70 to 80 70 to 80 70 to 80 NA (lbs/100 lbs) Density (g/cc) 2.2 2.2 2.2 2.2 pH in water 5 5 8.5 8.5 Cation 1.0-2.0 meq/g 1.0-2.0 meq/g 1.0-2.0 meq/g 1.0-2.0 meq/g Exchange Capacity Brookfield 820 820 27.5 NA Viscosity (cP@20 rpm) Hercules 138 138 1 NA Viscosity (kilodyne- cm@1100 rpm
[0049] As mentioned earlier in the specification, the present zeolite showed promise as filler in a papermaking furnish. That work was conducted at relatively low paper machine speed, about 200 fpm. These results were confirmed with the Britt Jar™ run at 500 rpm. Total solids retention with PCC was about 85% and with the present zeolite it was about 98%. Total solids retention remained very high with the present zeolite when used as the filler, even as Britt Jar™ speed was increased to 1500 rpm, as shown in Table 4. This was entirely unexpected.
TABLE 4 Total solids retention with varying Britt Jar ™ speeds Pigment 500 rpm 1000 rpm 1500 rpm 20% PCC 85% 78% 78% 20% ZOBrite-1 98% 98% 98%
[0050] These experiments were run with no retention aid added to the furnish and adjusted to pH 8. Even though these data represent total solids retention rather than retention of filler alone, they suggest that even under relatively high-shear conditions found on fast paper machines, the present zeolite may have a natural tendency to be retained in the sheet. The possibility exists that addition of the present zeolite as papermaking filler could reduce the need for expensive retention aids.
[0051] A series of Britt Jar™ runs were performed using a filler loading of 20% PCC. A suitable base retention aid system for this model furnish was determined to be 2 lb/ton cationic retention aid and 5 lb/ton cationic starch.
[0052] The summary data are presented below in Tables 5a-5c based on varying Britt Jar™ speeds.
TABLE 5a Britt Jar ™ results @ 1500 rpm % filler retention Std. Microparticle (avg.) deviation None 15.9 5.23 1 lb/ton silica 48.7 1.37 1 lb/ton ZO Brite-1 47.0 0.14 1 lb/ton ZO Brite-select 51.4 0.97 1 lb/ton ZO Brite-1 new 45.3 3.46 1 lb/ton ZO Brite-3 49.0 1.22 2 lb/ton bentonite 47.7 1.52 4 lb/ton bentonite 54.8 1.01
[0053]
TABLE 5b
Britt Jar ™ results @ 1000 rpm
% filler retention
Std.
Microparticle
(avg.)
deviation
None
50.7
3.52
1 lb/ton silica
63.6
0.64
1 lb/ton ZO Brite-1
63.6
0.35
1 lb/ton ZO Brite-select
64.6
1.07
1 lb/ton ZO Brite-1 new
60.9
3.98
1 lb/ton ZO Brite-3
68.7
0.53
2 lb/ton bentonite
68.9
2.7
4 lb/ton bentonite
71.8
0.8
[0054]
TABLE 5c
Britt Jar ™ results @ 500 rpm
% filler retention
Std.
Microparticle
(avg.)
deviation
None
97.8
0.98
1 lb/ton silica
85
2.23
1 lb/ton ZO Brite-1
89.8
1.46
1 lb/ton ZO Brite-select
85.6
1.38
1 lb/ton ZO Brite-1 new
84.1
1.8
1 lb/ton ZO Brite-3
96.9
1.26
2 lb/ton bentonite
94.8
2.01
4 lb/ton bentonite
93.4
2.68
[0055] The data in Table 5a represent the results one might expect on a relatively fast paper machine. Based on these runs, it was determined that adding a silica microparticle to the base retention aid system significantly improves filler retention, there is no statistical difference in performance between the silica used and ZO Brite-1 as a microparticle for filler retention, and there is no statistical difference in performance between ZO Brite-1 and ZO Brite-1 new as a microparticle for filler retention. However, it may be noteworthy that there is a large difference in the variation of performance of ZO Brite-1 new, compared to that of ZO Brite-1, as evidenced by the difference in standard deviations within each run. There is no statistically significant difference in performance between 2 lb/ton bentonite and 1 lb/ton ZO Brite-1 as a microparticle for filler retention. There is no statistically significant difference in performance between 2 lb/ton bentonite and 1 b/ton ZO Brite-3 as a microparticle for filler retention. But there is a statistically significant improvement in filler retention when using 4 lb/ton bentonite compared to using 2 lb/ton bentonite. This difference also exists when comparing 4 lb/ton bentonite to 1 b/ton ZO Brite-1 or 1 lb/ton ZO Brite-3. There is a statistically significant improvement in filler retention when using 1 lb/ton ZO Brite-select compared to using silica or ZO Brite-1. There is a statistically significant improvement in filler retention when using 1 lb/ton ZO Brite-select compared to using 2 lb/ton bentonite. 4 lb/ton bentonite generated better filler retention than 1 lb/ton ZO Brite-select when used as a microparticle for filler retention. Similar data were generated at Britt Jar™ speeds of 1000 rpm and 500 rpm. These are presented in Tables 5b and 5c.
[0056] The figures in the present application help illustrate the differences in performance that may exist between microparticles in this retention system under different paper machine operating speeds. This illustrates why retention aid systems need to be specifically tailored for a particular paper machine and grade of paper. The most significant conclusion from studying each of the following figures is that the present zeolite shows substantial promise as a microparticle for retention aid systems.
[0057] FIG. 1 illustrates the relative performance of the present zeolite, specifically ZO Brite-1 and ZO Brite-3, with silica over a range of Britt Jar™ speeds. The x-axis shows the range of Brift Jar™ speeds, 500 rpm, 1000 rpm and 1500 rpm, while the y-axis represents the % filler retention. At 500 rpm ZO Brite-1 and ZO Brite-3 have only slightly higher % filler retention than silica. Although visually encouraging, there is no statistical difference in performance between silica and ZO Brite-1 or ZO Brite-3 as a microparticle for filler retention at 500 rpm. When the speed is increased to 1000 rpm, the % filler retention for ZO Brite-1 and silica are the same with only ZO Brite-3 having a slightly higher % filler retention. At 1500 rpm, ZO Brite-1, ZO Brite-3 and silica show no significant difference in % filler retention. The present zeolites perform at least as well as silica over the entire range of Brift Jar™ speeds
[0058] FIG. 2 illustrates the relative performance of two zeolites of the present invention, namely ZO Brite-1 and ZO Brite-1 new. The x-axis shows the range of Britt Jar™ speeds, 500 rpm, 1000 rpm and 1500 rpm, while the y-axis represents the % filler retention. At 500 rpm, ZO Brite-1 had a higher % filler retention than ZO Brite-1 new. When the speed was increased to 1000 rpm, ZO Brite-1 had only a slightly higher % filler retention than ZO Brite-1 new. At 1500 rpm, the % filler retention for ZO Brite-1 and ZO Brite-1 new showed no significant differences.
[0059] While these two pigments appear to perform comparably, there is a statistically significant decrease in performance of ZO Brite- 1 new at low speed (500 rpm). While the difference at 1500 rpm is not statistically significant, it's most likely due to the variability of performance of the ZO Brite-1 new.
[0060] FIG. 3 illustrates the performance comparison between bentonite (2 lb/ton) and ZO Brite-1 and ZO Brite-3 (1 lb/ton). The x-axis shows the range of Britt Jar™ speeds, 500 rpm, 1000 rpm, and 1500 rpm, while the y-axis represents the % filler retention. There is no statistical difference between the bentonite performance (2 lb/ton) and that of the ZO Brite-1 or ZO Brite-3 (1 lb/ton) as the microparticle for filler retention, even at low speeds.
[0061] FIG. 4 illustrates the relative performance of silica, ZO Brite-1 and ZO Brite-select. The x-axis shows the range of Britt Jar™ speeds, 500 rpm, 1000 rpm and 1500 rpm, while the y-axis represents the % filler retention. At 500 rpm, ZO Brite-1 has a higher % filler retention than silica or ZO Brite-select. At 1000 rpm, each pigment shows approximately the same % filler retention. And at 1500 rpm, ZO Brite-select has a higher % filler retention than the other two pigments. As illustrated, there is a statistically significant improvement in filler retention at high Britt Jar™ speeds when using 1 lb/ton ZO Brite-select compared to using either silica or ZO Brite-1 as the microparticle in a retention aid system. It is evident from the data that the zeolite of the present invention can be used as a pigment filler for wet end addition, with a natural tendency to be retained at relatively high speeds, potentially reducing the need for retention aids.
[0062] The zeolite of the present invention can also be used in a microparticle retention aid system. ZO Brite-1 performed well against colloidal silica at comparable levels of addition. ZO Brite-1 also performed well at an addition level of 1 lb/ton against bentonite added at 2 lb/ton.
[0063] ZO-Brite-select, the smallest particle size tested for the zeolite of the present invention performed better at 1 lb/ton than either silica or ZO Brite-1 at comparable addition levels, and better than bentonite at 2 lb/ton.
[0064] Although the invention has been described with reference to specific embodiments, this description is not meant to be construed in a limited sense. Various modifications of the disclosed embodiments, as well as alternative embodiments of the inventions will become apparent to persons skilled in the art upon the reference to the description of the invention. It is, therefore, contemplated that the appended claims will cover such modifications that fall within the scope of the invention. | A microparticle retention aid for use in papermaking containing a high performance purified natural zeolite pigment is disclosed. Use of the pigment facilitates manufacture of papers with improved quality and economics. When used as filler, the novel zeolite pigment is readily retained and eliminates print-through in uncoated papers. The novel zeolite pigment is low in abrasion and provides improved coefficient of friction. | 3 |
BACKGROUND OF THE INVENTION
1. Field of the Invention
The present invention relates to centrifugal compressors in general and in particular to a roller positioning system for a variable pipe diffuser.
2. Background of the Prior Art
One of the major problems arising in the use of centrifugal vapor compressors for applications where the compressor load varies over a wide range is flow stabilization through the compressor. The compressor inlet, impeller and diffuser passages must be sized to provide for the maximum volumetric flow rate desired. When there is a low volumetric flow rate through such a compressor, the flow becomes unstable. As the volumetric flow rate is decreased from a stable range, a range of slightly unstable flow is entered. In this range, there appears to be a partial reversal of flow in the diffuser passage, creating noises and lowering the compressor efficiency. Below this range, the compressor enters what is known as surge, wherein there are periodic complete flow reversals in the diffuser passage, destroying the efficiency of the machine and endangering the integrity of the machine elements. Since a wide range of volumetric flow rates is desirable in many compressor applications, numerous modifications have been suggested to improve flow stability at low volumetric flow rates.
Many schemes have been devised to maintain high machine efficiencies over a wide operation range. In U.S. Pat. No. 4,070,123, the entire impeller wheel configuration is varied in response to load changes in an effort to match the machine performance with the changing load demands. Adjustable diffuser flow restrictors are also described in U.S. Pat. No. 3,362,625 which serve to regulate the flow within the diffuser in an effort to improve stability at low volumetric flow rates.
A common technique for maintaining high operating efficiency over a wide flow range in a centrifugal machine is through use of the variable width diffuser in conjunction with fixed diffuser guide vanes.
U.S. Pat. Nos. 2,996,996 and 4,378,194, issued to a common assignee, describe variable width vaned diffusers wherein the diffuser vanes are securely affixed, as by bolting to one of the diffuser walls. The vanes are adapted to pass through openings formed in the other wall thus permitting the geometry of the diffuser to be changed in response to changing load conditions.
Fixedly mounting the diffuser blades to one of the diffuser walls presents a number of problems particularly in regard to the manufacture, maintenance and operation of the machine. Little space is afforded for securing the vanes in the assembly. Any misalignment of the vanes will cause the vane to bind or rub against the opposite wall as it is repositioned. Similarly, if one or more vanes in the series has to be replaced in the assembly, the entire machine generally has to be taken apart in order to effect the replacement.
The efficiency of a compressor could be greatly enhanced by varying the outlet geometry of the diffuser. In U.S. patent application Ser. No. 08/658801, commonly assigned, a variable geometry pipe diffuser is disclosed. That application is hereby incorporated by reference. A variable geometry pipe diffuser (which may also be termed a split-ring pipe diffuser) splits the diffuser into a first, inner ring and a second outer ring. The inner and outer rings have complementary inlet flow channel sections formed therein. That is, each inlet flow channel section of the inner ring has a complementary inlet flow channel section formed in the outer ring. The inner ring and outer ring are rotatable respective one another. The rings are rotated to improve efficiency for varying pressure levels between a fully open position and a partially closed position. In the partially closed position the misalignment of the exit pipes of the diffuser causes an increase in noise. Rotation of the rings past an optimum design point results in excessive noise and efficiency degradation.
The geometrical tolerances within a centrifugal compressor are small. At the same time the loads within the compressor are large and dynamic in nature. In a split ring pipe diffuser the problem of maintaining tolerances in the face of the dynamic loading becomes quite onerous. There are both axial (thrust) loads and circumferential loads on the ring pair that need to be managed. The diffuser rings must be able to rotate relative to one another and at the same time tight control over their relative position must be maintained in order to ensure proper alignment of the flow channels and the ultimate efficiency of the compressor. The cost of maintaining the necessary tolerances in a split ring diffuser is generally very high.
Another problem with split ring diffusers is premature part wear. Lubricants are generally not used within the gas flow regions of centrifugal compressors to preclude contamination of the gases. The dynamic loads imposed upon the split ring diffuser by the gas flow exiting the impeller cause wear in the components of the diffuser to be accelerated by the absence of lubricating oil.
The drive system for accurately positioning the rings relative to one another must, among other things, be rigid to avoid any fretting of components. Because of circumferential loading on the rings there is a propensity for the inner ring to oscillate relative to the outer ring which could cause compressor instability, part wear and could adversely affect efficiency. This causes several problems that need to be overcome. A drive system is needed that is capable of preventing the relative movement between the inner and outer rings. A bearing concept is also needed which would allow for the relative rotation of the two rings and also be capable of withstanding the circumferential and thrust loads while maintaining tight geometric tolerances between the rings. There is also a need to provide a positioning system that includes positive minimum and maximum stops to avoid unnecessary noise and efficiency degradation as well as simple field retrofit. In addition, there is a need for the drive and bearing systems have a long operating life and be easy to install and adjust properly.
SUMMARY OF THE INVENTION
According to its major aspects and broadly stated, the present invention relates to a variable geometry pipe diffuser for a centrifugal compressor. More specifically the present invention relates to a roller positioning system for use in a variable geometry pipe diffuser for a centrifugal compressor.
Roller bearings of the ring support system of the present invention support the inner ring within the outer ring of a variable pipe diffuser. The roller bearings are mounted on the cylindrical bodies of the axle shafts about a first centerline. The axle shafts are mounted within the outer ring supported by shoulders concentric about a second centerline. The inner ring is positioned within the roller bearings and the axle shafts are rotated to about the second centerline to adjust the roller bearings to come in contact with the inner ring. A preselected amount of preload can be exerted by the roller bearings against the inner ring by varying the amount of rotation of the axle shafts. The roller bearings are then releasably fastened to secure the roller bearings at a selected adjustment position.
BRIEF DESCRIPTION OF THE DRAWINGS
In the drawings, wherein like numerals are used to indicate the same elements throughout the views;
FIG. 1 is a cross-section side view of compressor according to the invention having a variable pipe diffuser according to the present invention;
FIG. 2 is a perspective view of a variable pipe diffuser according to the invention;
FIGS. 3 and 4 are cross-sectional front views of a variable pipe diffuser in accordance with the invention in a first, fully open, and a second, partially closed position, respectively;
FIG. 5 is a top view of a compressor having a variable diffuser of the present invention;
FIG. 6 is a cross section view of a ring support mechanism of the present invention taken substantially along line 6--6 in FIG. 5;
Fig. 7 is a cross section view of a ring support mechanism of the present invention taken substantially along line 7--7 in FIG. 6;
FIG. 8 is a cross section view of a roller assembly of the present invention;
FIG. 9 is a cross section view of an axle of the present invention;
FIG. 10 is a cross sectional view of a positioning drive mechanism of the present invention of detail area 10 in FIG. 1;
FIG. 11 is a top view of a positioning drive mechanism of the present invention;
FIG. 12 is a perspective view of a rack gear of the present invention;
FIG. 13 is a performance diagram for a variable pipe diffuser according to the present invention;
FIG. 14 is a performance diagram for a compressor having inlet guide vanes only;
FIG. 15 is a performance diagram for a compressor according to the present invention having a variable pipe diffuser and inlet guide vanes; and
FIG. 16 is a cross sectional view of a compressor having an axial restraint mechanism according to the present invention.
DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS
Referring now to FIG. 1, the invention is shown as installed in a centrifugal compressor 10 as part of an HVAC system (not shown) having an impeller 12 for accelerating refrigerant vapor to a high velocity, a diffuser 14 for decelerating the refrigerant to a low velocity while converting kinetic energy to pressure energy, and a discharge plenum in the form of a collector 16 to collect the discharge vapor for subsequent flow to a condenser. Power to the impeller 12 is provided by an electric motor (not shown) which is hermetically sealed in the other end of the compressor and which operates to rotate a high speed shaft 19.
Referring now to the manner in which the refrigerant flow occurs in the compressor 10, the refrigerant enters the inlet opening 29 of the suction housing 31, passes through the blade ring assembly 32 and the guide vanes 33, and then enters the compression suction area 23 which leads to the compression area defined on its inner side by the impeller 12 and on its outer side by the housing 34. After compression, the refrigerant then flows into the diffuser 14, the collector 16 and the discharge line (not shown).
A variable geometry pipe diffuser 14 according to the present invention includes a first, inner ring 40 and a second outer ring 42, a ring support mechanism 35, and a positioning drive mechanism 121. Referring to FIGS. 3 and 4 the inner and outer rings have complementary flow channel sections 44 and 46 formed therein. That is, each flow channel section 44 of the inner ring 40 has a complementary channel section 46 formed in outer ring 42. Inner ring 40 and outer ring 42 are rotatable with respect to one another. In a preferred embodiment, inner ring 40 rotates circumferentially within a stationary outer ring 42.
When one ring is rotated with respect to the other, the alignment between each pair of complementary inlet flow channels of the inner and outer rings changes as seen with reference to FIGS. 3 and 4. Rings 40 and 42 are adjustable between a first fully open position, as illustrated in FIG. 3, wherein complementary channel sections are aligned and a maximum amount of fluid passes through inner and outer rings 40 and 42, and a second, partially closed position, as illustrated in FIG. 4, wherein complementary channels are misaligned and flow through the channel sections 44 and 46 is restricted.
In FIG. 5 a ring support mechanism 35 according to an embodiment of the present invention is shown. The embodiment shown illustrated the use of three such mechanisms spaced circumferentially equidistant about the diffuser. Referring now to FIGS. 6-7 the ring support mechanism of the present invention includes an inner bearing slot 41 and a cutout 43 disposed in inner ring 40, a roller assembly 54, a roller axle assembly 36 and an outer bearing slot 45 disposed in the outer ring. The roller assembly as shown in FIG. 8 includes a roller 55 having an outer bearing surface 56, and a pair of thrust bearing surfaces 57. The axle assembly as shown in FIGS. 6-7 includes an axle 37 and an axle bolt 39. As seen in FIG. 9 axle 37 includes a hex head 38 and an axle body 47, an axle body centerline 48, an axle bore 49 and an axle bore centerline 50. In addition the axle 39 includes a pair of shoulders 73, 74 concentric with axle bore centerline 50.
Another problem with split ring diffusers is premature part wear. Lubricants are generally not used within the gas flow regions of centrifugal compressors to preclude contamination of the gases. The dynamic loads imposed upon the split ring diffuser by the gas flow exiting the impeller cause wear in the components of the diffuser to be accelerated by the absence of lubricating oil. Due to the nonavailability of lubricating oils in most compressors it is usually necessary to take steps to minimize friction and fretting wear. Accordingly, in certain embodiments of the present invention and as described herein below, component interfaces are hard coated, parts are manufactured from ultra high molecular weight plastic materials, the ring assemblies are preloaded and backlash is eliminated from the gears of the positioning drive system.
Referring now to the manner in which the inner ring is assembled and its movement. The outer ring 42 is stationary with respect to the suction housing and three sets of ring support mechanisms 35 are installed into the outer ring by positioning the roller assembly 54 within the bearing slot 45 of the outer ring, passing the axle through the mounting hole 58 and the roller assembly and then installing the axle bolt 39 through the axle and loosely threading the axle bolt 39 into threaded holes 59 in the outer ring. The inner ring 40 is installed inside of the outer ring with the cutouts 43 of the inner ring circumferentially aligned with the bearing slot 45 and the roller assemblies 35 and then rotating the inner ring clockwise as shown in FIG. 7 to position the roller assemblies within the bearing slot 41. With the inner ring installed within the outer ring the ring support mechanisms are employed to properly center and position the inner ring by rotating the axle through the use of a wrench placed on the hex head 38. The axle body centerline 48, on which the roller 55 is mounted is offset from axle bore centerline 50, which is concentric with the shoulders 73, 74, by 0.021 inches. The rotation of hex head 38 causes the roller assembly to rotate about the shoulders within the outer ring and causes the roller assembly to be radially displaced relative to the outer ring. Once the inner ring is properly centered within the outer ring the hex head is further rotated to preload the outer bearing surface 56 of the roller assemblies against the inner ring. The axle bolt 39 is then tightened. The preload conditioned is preferred because it prevents the inner ring from movement due to tangential and circumferential loads. In an embodiment of the present invention the roller 55 and the inner ring 40 are aluminum and both the outer bearing surface 56 and the inner bearing slot 41 are hardened to prevent wear. The roller assemblies restrain movement of the rings in the axial direction due to thrust loads by positioning the thrust bearing surfaces 57 within the hardened inner bearing slot 41 and the relatively soft outer bearing slot 45. The thrust bearing surface 57 of the roller assembly must allow for the rotation of the inner and outer rings and at the same time withstand the thrust loads produced by the compressor. In a preferred embodiment the thrust bearing surface 57 is manufactured from ultra high molecular weight plastic having a low coefficient of friction of 0.16 and a hardness of 64 on the Shore D scale. The plastic thrust bearing surfaces prevent contact between the hardened roller and the soft outer bearing slot and are utilized to carry the thrust loads of the compressor and to adjust axial tolerances of the inner ring. An additional feature of the ring support mechanisms is that with the rings assembled as described above it is possible pre-assemble the inner and outer rings and transport them to the compressor for finally assembly.
Another embodiment of the present invention for limiting and precluding axial movement of the inner ring relative to the outer ring is shown in FIG. 16. There is shown an axial restraint system 90 comprising a threaded shaft 91, a threaded mounting hole 92, a bearing pad 93, a lock nut 94, a hex head 95, and a recess 96. During assembly of the diffuser the axial restraint mechanism 90 is installed such that the bearing pad 93 is positioned in the recess 96. The bearing pad positioned within the recess allows clearance for the shroud 34 to be mounted to outer ring 42 without accidental contact of the bearing pads with the inner ring. Once housing 34 is installed the threaded shaft 91 is rotated to bring the bearing pad in contact with the inner ring. With the bearing pad properly positioned the mechanism is releasably fastened by tightening lock nut 94. In a preferred embodiment the bearing pad is manufacture from an ultra high molecular weight plastic material. An embodiment of the present invention includes six such axial restraint mechanisms positioned circumferentialy equally spaced about the inner ring.
A positioning drive mechanism 121 for rotating inner ring 40 circumferentially within outer ring 42 is described with reference FIG. 10. Outer ring 42 has fixedly attached thereto rack gear 123 which extends radially outwardly from outer ring 42. In gearing relation with rack gear 123 is pinion gear 124 which is driven via pinion axle 126 by actuator 128. Actuator 128 is selected and controlled to effect movement of inner ring 40 in relation to outer ring 42 between a first fully open position and a second partially closed position and any number of intermediate positions therebetween. Axle 126 is housed in a containment housing 130 which hermetically seals axle 126 from compressor interior 132 and which prevents leakage of fluid out of compressor 10 through containment housing 130. The tangential and circumferential loading on the rings by the refrigerant flow within the diffuser causes the inner ring to have the propensity to chatter back and forth within the outer ring. Excess movement or chattering of the inner ring would cause the rack gear 123 and the pinion gear 124 to fret and also cause other parts to wear. Preloading the inner ring via the roller assemblies as discussed herein earlier prevents movement of the inner ring as well as chattering under normal operating conditions. In cases of abnormal conditions, such as operating in a surge, a secondary mechanism is needed to prevent motion of the inner ring. The present invention provides for a drive mounting system to prohibit adverse movement and chattering of the inner ring by preventing the backlash between the segment gear and the pinion gear via adjustment of the relative center positions of the pinion gear and the rack gear utilizing the axle containment housing 130. The axle housing outer surface 125 is concentric about housing centerline 127 and housing bore 129 is concentric about housing bore centerline 131. In an embodiment of the present invention the housing centerline 127 and the housing bore centerline 129 are offset by 0.060 inches. Referring to FIG. 11 there is shown wrench flats 135 and adjustment slots 134 of the positioning drive mechanism. After installation of the positioning drive mechanism into the suction housing 31 the backlash between the rack gear 123 and the pinion gear 124 is removed by rotating the drive positioning mechanism by placing a wrench (not shown) across wrench flats 135. Once minimal backlash is achieved the positioning drive mechanism is fixed in place by the tightening of cap screws 133. Once the backlash is eliminated the tendency for the inner ring to move is discharged directly by the actuator through the gear system.
The flow of fluid through diffuser 14 in a second partially closed position in relation to the fully open position flow rate is determined by the ratio of the minimum cross-sectional area of a flow channel of a diffuser in a partially closed position to the minimum cross-sectional area of a flow channel (defined by complementary channel sections 44 and 46) in a fully open position. This minimum flow channel area, known as the "throat area" will generally be determined by the smallest diameter of the flow passage 52 of the inner ring channel 44 when diffuser 14 is in a fully open position, and will be controlled by the width 53 at the interface between the inner and outer rings 40 and 42 when diffuser 14 is in a second partially closed position. For example, if a diffuser channel has a minimum area (throat area) of 1/8 sq. in. in a second partially closed position, and a minimum area (throat area) of 1/4 sq. in. in a fully open position then the volumetric flow rate of fluid through a diffuser in the partially closed position will be about 50% of the flow rate as in the fully open position. The flow rate of fluid through compressor 10 when diffuser 14 is in a second, partially closed position, will generally be between about 10% and 100% of the flow rate of fluid through compressor 10 when diffuser is in the first fully open position.
In a second partially closed position (FIG. 4), at least about 10% the volume of flow as in the fully open position should flow through diffuser 14 so as to prevent excessive thermodynamic heating, excessive noise and a degradation in the efficiency of the compressor. To this end, the amount of relative rotation between the two ring sections should be limited to an amount of rotation necessary to effect a second partially closed position. In other words, the rings should not be adjustable to completely close off a flow of fluid therebetween. The degree of allowable rotation between the two rings is determined by the desired flow between the rings in a fully closed position, and the number and volume of inlet flow channel sections 44, 46 in the ring sections 40 and 42 in relation to the volume of the ring sections 40 and 42.
Continuing with reference to FIG. 4, R 2 defines the radius of the impeller tip, R 3 defines the outside radius of inner ring 40, and R 4 defines the outside radius of outer ring. By making the thickness, defined by the Quantity T=R 3 -R 2 of inner ring 40 no larger than is necessary to block a desired portion (e.g. 50% of flow) of flow through outer ring channels 46, the flow of fluid through diffuser 14 can be efficiently controlled. Rotation of the inner ring with respect to the outer ring will reduce the diffuser throat area before any diffusion has taken place, thus preventing flow acceleration after diffusion. Also, the smaller the inner ring thickness, T, the smaller the turning angles of the flow through diffuser in the partially closed position. Both of the above-described effects tend to improve compressor efficiency under part-load operating conditions.
Referring now to FIGS. 5 and 12 an embodiment of the present invention is shown having a mechanism to provide positive positioning of the inner ring corresponding to a first fully open position and a second partially closed position. Cavity 137 is machined in outer ring 42 to accommodate rack gear 123. Rack gear 123 is accurately mounted to inner ring 40 in a tongue and groove fashion wherein the rack gear is provided with a circumferential groove 143 adapted to receive tongue section 139 of inner ring 40. To determine the fully opened position the inner ring is positioned within the outer ring and the rings are rotated relative to one another until flow passages 52 are fully aligned with outer flow channels 46. With the rings in this position, and the ring support mechanism adjusted as described herein above, the rack gear is mounted to the inner ring with gear face 145 in contact with full open stop 140 of cavity 137. Bolts (not shown) are then installed through gear mounting holes 142 and securely and tightened into threaded holes 138 in the inner ring. The rack gear and the cavity are sized to provide for a predetermined amount of closure of the pipe diffuser. For example in an embodiment of the present invention a is sized such that difference between the rack gear angular width and the cavity provide for a 10% open position. In this example the required travel of the rack gear is 10 degrees, the rack gear angular width is 35 degrees and the corresponding cavity angular width is 45 degrees. With the rack gear thusly positioned a positive stop is created between the rack gear and the cavity to accurately and repeatably position the rings at points corresponding to a fully open position and a partially closed position. The positive stops also allow for field retrofit of actuator 128 without the need to adjust the position of the inner and outer rings.
Operation and use of the present invention can be understood with reference to FIG. 5 showing a performance diagram for a compressor having a variable pipe diffuser according to the invention integrated therein. The performance diagram of FIG. 5, includes a plurality of performance plots 60, 62, 64, 66 and 68, each corresponding to a discreet positioning between inner and outer ring sections 40 and 42. Each performance plot, e.g. 60, is characterized by a surge point, e.g. 70, which is the point of maximum available pressure. Operating a compressor at a flow rate at or below the surge point will likely result in a surge condition, as discussed in the Background of the Invention section herein.
For purposes of illustrating the invention, plot 60 may correspond, for example, to a first, fully open position, plot 62 may correspond to an intermediate 2 degree partially closed position, plot 64 may correspond to an intermediate 4 degree partially closed position, and plot 68 may correspond to a maximum 8 degree partially closed position.
It is seen that adjusting ring sections 40 and 42 toward a closed position has the effect of adjusting the surge point e.g. 70, 72 in a performance plot for a compressor toward a lower flow rate. Thus, a surge condition can be avoided during periods of low flow demand by adjusting diffuser rings 40 and 42 toward a closed position.
It is helpful to understanding the invention to compare performance diagram of FIG. 5, for a compressor having a variable diffuser to the performance diagram shown in FIG. 6 corresponding to a compressor having adjustable inlet guide vanes only. In FIG. 6, plots 80, 82, 84, and 86 and 88 correspond to discreet positioning of guide vanes 33 in increasingly closed positions. It is seen that closing guide vanes 33, like the closing of diffuser ring sections 40 and 42 has the effect of lowering the surge point flow rate. Thus, a surge condition can often be avoided by adjusting inlet guide vanes 33 toward a closed position.
However, it is seen from the performance diagram of FIG. 6 that adjusting guide vanes 33 toward a closed position has the further effect of lowering the head pressure available from compressor 10 at the surge point. Hence, a low flow rate operating condition requiring a relatively high pressure cannot be satisfied by adjusting guide vanes 33 alone.
By contrast, it is seen from the performance diagram of FIG. 5 that surge point pressure available from compressor 10 remains essentially stable when diffuser rings 40 and 42 are adjusted toward a closed position. Hence an operating condition requiring a low flow rate and high compressor pressure can be satisfied by adjusting diffuser rings 40 and 42 toward a closed position.
An operating condition requiring a low flow rate and a high pressure ratio relative to the full load operating pressure ratio (e.g. 90% of full load) is common in the case where there is a large difference (e.g. about 50° F. or more) between the ambient air temperature and indoor temperature, but occasional light loading in a building being cooled. In such a situation, a relatively high compressor pressure ratio (e.g. above about 2.5) is required by the refrigerant saturation pressures corresponding to the condenser, and evaporation temperatures, but only a reduced flow rate e.g. 25% of full load is needed to remove the heat generated within the building.
FIG. 7 shows a performance diagram for a compressor having both adjustable guide vanes and a variable pipe diffuser in accordance with the invention. It is seen that efficiency of a compressor can often be optimized by combining an adjustment of guide vanes 33 with an adjustment of diffuser rings 40 and 42. With reference to FIG. 7 dash curves 111, 112, 113, 114, 115, and 116 show performance plots for a compressor having a variable diffuser in a fully open position for various positioning of inlet guide vanes 33, while solid curves 101, 102, 103, 104 and 105 show performance plots for a compressor having partially closed (here, there is about 40% of original flow rate in the closed position) diffuser rings at various guide vane positioning. As is well known to those skilled in the art, a compressor operates at optimum efficiency when operating at the "knee" (e.g. 81 at FIG. 6) of the performance plot characterizing performance of the compressor. With reference to diagram 7, the operating condition requiring, for example, a pressure of about 0.7 maximum, and a flow rate of about 0.3 maximum would be most efficiently satisfied by a compressor operating in accordance with plot 104, realized by adjusting diffuser rings 40 and 42 to a closed position and by adjusting guide vanes 33 to a 10 degree position.
While the present invention has been explained with reference to a number of specific embodiments, it will be understood that the spirit and scope of the present invention should be determined with reference to the appended claims. | A roller positioning system for use in a variable pipe diffuser having inner and outer rings. The roller positioning system having at least three axle shafts having a cylindrical body positioned about a first centerline and having a bore disposed axially therethrough about a second centerline. A roller bearing is rotatably mounted to the body of each of the at least three axle shafts. The at least three axle shafts also having a pair of shoulders positioned on either side of the body concentric about the second centerline. The at least three axle shafts circumferentially disposed in the outer ring about the shoulders in a diameter such that the roller bearings nearly contact the outside diameter of the inner ring. The at least three axle shafts rotatably operable to effect an adjustment of the roller bearings about the second centerline such that the roller bearings are brought into contact with the inner ring. | 5 |
This application is a continuation of Ser. No. 08/866,335 filed May 30, 1997 now U.S. Pat. No. 5,921,919.
FIELD OF THE INVENTION
This invention relates to apparatus and method for accessing within a working cavity a vessel to be harvested for use, for example, in coronary artery bypass surgery, and more particularly to a multi-component system and method for facilitating expansion of a working cavity along the course of a vessel of interest.
BACKGROUND OF THE INVENTOR
A perivascular cavity may be formed along the course of a vessel to be harvested using a cannula having a transparent tapered tip. Such devices and procedures dissect tissue planes adjacent the target vessel while visualizing the vessel and connective tissue through the transparent tip via an endoscope within the cannula. Devices and procedures of these types are disclosed in the literature (See, for example, U.S. patent applications Ser. Nos. 08/593,533 now abandoned, and 08/502,494 now abandoned).
Once the perivascular cavity is formed adjacent the target vessel, it is desirable to retain the cavity in expanded condition to facilitate the surgeon's manipulation of connective tissue and lateral or branch vessels in order to liberate, "or harvest", the target vessel from the surgical site. Insufflation of the perivascular cavity using gas such as CO 2 under pressure is commonly used to expand the working space within the cavity, but this procedure inhibits relatively free movement of instruments about the vessel of interest within the insufflated cavity due to the requirement for a gas-sealing port into the cavity. In contrast, mechanical retraction mechanisms are known which physically expand at least an entry portion of the cavity to facilitate direct visualization into the cavity, essentially via eye-level alignment with the separated tissue planes at the entry portion of the cavity. Simple traction mechanisms such as a stiff rod inserted into the perivascular cavity to lift up or otherwise retract the surrounding tissue away from the vessel of interest are known to be marginally useful because an additional hand may be occupied keeping adjacent tissue in tension via such retraction rod.
SUMMARY OF THE INVENTION
In accordance with the present invention, a self-retaining retractor and associated fixture allow a surgeon to use both hands freely for surgical manipulation and tissue dissection. An endoscope is held in position along the retractor to facilitate the surgeon's manipulation of two instruments at the same time in contrast to manipulating only one instrument while positioning the endoscope.
In one embodiment, a channeled retractor includes an upturned distal end above a grooved or channeled receptor that receives and supports therein the objective end of an endoscope. The upturned distal end promotes enhanced separation of connective tissue in view of the endoscope as the retractor is advanced into the perivascular cavity adjacent the target vessel. The grooved or channeled receptor receives the tip of an endoscope of, say, 5 mm diameter for clear visualization of tissue distal to the upturned end of the retractor as the retractor is advanced into the perivascular cavity. The channel of the retractor supports a tube which supports the endoscope therein, and such channel may be formed of a pair of stiff rods mounted in parallel spaced orientation, with the supporting tube disposed intermediate the space between rods that form the retractor.
The proximal end of the retractor includes a detachable coupler for convenient attachment to a handle to facilitate initial manual insertion of the retractor into the perivascular cavity, and thereafter for convenient attachment to a retractor frame for maintaining the retractor in elevated position relative to the target vessel.
BRIEF DESCRIPTION OF THE DRAWINGS
FIG. 1 is a side view of the retractor according to one embodiment of the present invention;
FIG. 2 is an end view of the retractor of FIG. 1;
FIG. 3A is a top view of the retractor of FIG. 1;
FIG. 3B is a bottom view of the retractor of FIG. 1;
FIG. 4 is a side view of the retractor of FIG. 1 illustrating an attached handle;
FIG. 5 is a side view of a retractor frame according to one embodiment;
FIG. 6 is an end view of the retractor frame of FIG. 5;
FIG. 7 is a top view of the retractor frame of FIG. 5;
FIG. 8 is a side view of the retractor of FIG. 1 and the retractor frame of FIG. 5 in assembled configuration;
FIG. 9 is an end view of the assembly of FIG. 8 in operation within and about a perivascular cavity;
FIG. 10 is a top view of the assembly of FIG. 8;
FIG. 11 is a side view of an endoscope support sleeve for longitudinally slidable engagement with and support by the retractor; and
FIG. 12 is a side view of the assembly of FIG. 8 including an endoscope and support sleeve disposed on the retractor of FIG. 1.
DETAILED DESCRIPTION OF THE INVENTION
Referring now to FIGS. 1, 2, and 3A there is shown a relatively rigid retractor formed of stiff rods 9, 11 that extend in substantially parallel spaced orientation to a distal end 13 that includes an upturned tip 15 and an underside channel or groove 17. The rods 9, 11 terminate at the proximal end via an upward bend 18 to rigid attachment to a connector block 19 that may, for example, include a longitudinal inverted "T"-shaped slot 21 therein. An elastic band 23 may be disposed near the distal end, for example, at the upward bend 18 to provide support near the proximal end for an endoscope support sheath, as later described herein. Of course other channeled or grooved configuration between proximal and distal ends of the retractor may also be used to provide rigidity, supporting space for an endoscope and detaching coupling to a handle at the proximal end.
Referring now to FIG. 3B, there is shown the underside of the elongated retractor with a protective and supportive sleeve or sheath 27 positioned, in the illustrated embodiment, substantially coplanarly with and between the rods 9, 11. An endoscope 53 is disposed within the protective sheath 27 and extends beyond the end of the sheath 27 to align within the underside groove 17 to a selected position in the tip 13 that provides adequate visualization during insertion of the retractor into a perivascular cavity. The sliding support 31 at the distal end of the sheath 27 may be configured to slide along the lengths of, and be retained by, the rods 9, 11 up to the cutout sections 20 of the rods 9, 11. In another embodiment, the sliding support 31 is formed with sufficiently larger dimensions than the spacing between rods 9, 11 to prevent the distal end of the sheath 27 from passing between the rods 9, 11. The cutout sections 20 thus permit the sliding support 31 to disengage from the rods 9, 11 to enable the objective end of endoscope 53 to be positioned into the underside groove 17. As the endoscope 53 is advanced into the underside groove, the sliding support abuts the distal end of the cutout sections 20 to prevent further extension of the endoscope 53 into the tip 13. The cutout sections 20 thus allow the endoscope 53 to be positioned into the underside groove 17 in the tip 13 with the endoscope sheath or sleeve 27 in place, and also provide a stop for the endoscope 53. In operation, the sleeve 27 is attached to the endoscope 53 prior to placement of the retractor into a perivascular cavity. The endoscope 53 is retained in fixed longitudinal position within the sheath 27, as later described herein, and the forward extension of the endoscope 53 and sheath 27 is stopped by the sliding support 31 against the distal end of the cutout sections 20 rather than by the lens of the endoscope and a wall of the underside groove 17.
Referring now to FIG. 4, there is shown the retractor of FIGS. 1, 2 and 3A including a handle 25 attached within the coupler 19, and the endoscope support sleeve 27 disposed along the channel or groove (i.e., spacing between spaced parallel rods 9, 11) substantially to the position of the distal tip 13. The sleeve or sheath 27 is a thin-wall rigid tube that includes at the proximal end a threaded endoscope coupling collar 29 for mating with and holding therein an endoscope with mating threaded proximal end, and includes at the distal end a sliding support 31. The sleeve or sheath 27 may be flexibly supported near its proximal end by the elastic band 23 positioned near and between the upturned section 18 of the rods, and may be supported at its distal end by the slidable support 31 within the channel between rods 9, 11. In this configuration, an endoscope disposed within the sleeve or sheath 27 may be supported thereby and may include an objective viewing end extended beyond the sheath 27, into the groove or channel on the lower side of the tip 13, substantially to a position near or beneath the upturned tip 15. Thus configured, the retractor with attached handle 25 and endoscope (not shown) within the sleeve or sheath 27 may be manually inserted into a perivascular cavity formed along the target vessel to be harvested, substantially to the entire length thereof to the upturned region 18. Then, the handle 25 may be conveniently detached from the coupler 19 for attachment to the elevator of the retractor frame, as shown in FIGS. 5, 6, and 7.
Referring to these figures, there is illustrated one embodiment of a supporting frame including a base formed of stiff rod 33 in a looped configuration, and a yoke 35 to retain the sides of the base formed by rod 33 in substantially parallel orientation. The distal end of the base may include upturned end loop 37, and the proximal end of the base may include the ends 39, 41 of the looped rod 33 bent in divergent pattern but in substantially planar configuration. A mating T-shaped receptor 43 is configured to facilitate sliding attachment to the T-shaped slot in the coupler 19 of the retractor of FIGS. 1, 2, 3A, and is disposed on a ratcheted, manually-adjustable vertical post 45. A T-shaped handle (or other conveniently-grippable knob) 47 on the upper end of the post 45 enables the surgeon to elevate the post 45 and attached retractor, assembled as illustrated in FIGS. 8, 9 and 10, to an extent that expands or distends a perivascular cavity 49 by elevating the adjacent skin and tissue 51, as illustrated in the end view of FIG. 9. In this way, the surgeon can retain tactile control on the extent or degree of stretching of skin and tissue 51, thereby to minimize vascular damage and possible skin necrosis. The base of the retractor frame 33 is positioned on the patient in proximity, and substantially along the course, of the target vessel.
Following elevation of the retractor 9, 11, the endoscope (which provided visualization during insertion of the tip 13, 15 into the perivascular cavity) may be withdrawn. The slidable support 31 at the distal end of the supporting sleeve or sheath 27 may engage the two rods 9, 11 for support therebetween to support the distal end during withdrawal, while the elastic band 23 supports the sleeve or sheath 27 near the proximal end during withdrawal of the sleeve or sheath 27 and the contained endoscope. The sleeve or sheath 27, as illustrated in FIG. 11, is thus slidably mounted in the space between rods 9, 11 (or within other channel or groove configuration), with the distal end thereof supported by the sliding support 31 for convenient sliding placement and withdrawal of the sleeve 27 and enclosed endoscope.
Referring now to FIG. 12, there is shown a side view of the assembled retractor, with endoscope 53 and retractor frame, shown at elevated position on the ratcheted vertical post 45. Of course, the endoscope 53 may include an imaging camera of conventional construction mounted at the location of the eyepiece for tradition television imaging of the operating site within the field of view of the endoscope. The elevational setting of the retractor relative to the rod 33 that forms the base of the retractor frame may be lowered against ratcheted stops by depressing release button 55 that disengages the ratcheting spring 57 from the ratchet stops 59 along the vertical post 45.
Therefore, the retractor and associated assemblies and procedures described herein greatly facilitate manually-controlled insertion (under endoscopic visualization) and elevation of a retractor within a perivascular cavity for maximum exposure and access to tissue therein. The parallel rods which comprise the elongated loop lifts a planar section of the cavity, but allows access to all tissue not in contact with the rods. In this way, a surgeon may form a distended or expanded perivascular cavity along the length of a vessel of interest (such as the saphenous vein), and may then proceed to dissect the vessel from connective tissue, occlude lateral or branch vessels, or otherwise perform tissue manipulations to harvest the vessel of interest in known manner within the ample space provided within the distended perivascular cavity by the elevated retractor and retractor frame assembly. Thereafter, the retractor may be released from the elevated position by releasing the ratcheted vertical post, and may then be withdrawn from the perivascular cavity, and the retractor frame can be removed from its position of the skin of the patient.
The combination of the sleeve or sheath with a sliding support tip at the distal end thereof, and with an elastic band near the proximal end of the retractor allows the endoscope to move along the cavity with the retractor while being maintained in the correct orientation to visualize the main bore of the perivascular cavity. The retractor may remain stationary and support the cavity while the position of the endoscope may be adjusted along the length of the cavity.
The coupling or connector block between the elongated retractor, the removable handle, and the retractor frame allows careful placement of the elongated retractor in the subcutaneous space under direct vision, without injury to the vessel of interest. The retractor frame can be added after placement of the retractor. The retractor frame may be positioned and the retractor may be elevated without disturbing the longitudinal position of the retractor, thereby avoiding shear forces against the vessel and surrounding tissue that may cause injury.
The ratchet lock system on the vertical post allows the operator to easily lift the ceiling of the cavity, and gauge the amount of force exerted on the skin. Excessive stretching which may cause devascularization of the skin, leading to skin necrosis, is avoided by relying upon direct mechanical lifting rather than upon a screw type of lift that can contribute increased mechanical advantage to elevate the ceiling of the perivascular cavity with concomitant increased possibility of injury to the skin due to excessive stretching under screw-magnified applied force. | Apparatus and method for expanding a perivascular cavity at a surgical site includes an elongated retractor having a tip at the distal end for convenient insertion into a perivascular cavity, and having a slidable coupler near the proximal end for convenient coupling to an elevator element supported in a retractor frame. The elongated retractor supports an endoscope thereon to facilitate visualization of surrounding tissue during insertion into the perivascular cavity. With the retractor inserted in the cavity, the retractor frame is positioned on the skin in alignment with and straddling the cavity, and the elevator element is selectively coupled to the retractor to elevate the retractor relative to the base of the retractor frame, thereby to expand or distend the cavity to provide ample access to tissues and vessels for surgical manipulations within the cavity. | 0 |
SUMMARY OF THE INVENTION
This invention relates to novel 5-carbamoylthieno[2,3-b]thiophene-2-sulfonamides which are useful in the reduction of elevated intraocular pressure. More particularly this invention relates to compounds having the structural formula: ##STR1## wherein R 1 and R 2 are hereinafter defined, as well as the pharmaceutically and ophthalmologically acceptable salts thereof. This invention also relates to pharmaceutical compositions for systemic and ophthalmic use employing a novel compound of this invention as active ingredient for the treatment of elevated intraocular pressure, especially when accompanied by pathological damage such as in the disease known as glaucoma. This invention also relates to processes for the preparation of 5-carbamoylthieno[2,3-b]thiophene-2-sulfonamides.
BACKGROUND OF THE INVENTION
Glaucoma is an ocular disorder associated with elevated intraocular pressures which are too high for normal function and may result in irreversible loss of visual function. If untreated, glaucoma may eventually lead to blindness. Ocular hypertension, i.e., the condition of elevated intraocular pressure without optic nerve head damage or characteristic glaucomatous visual field defects, is now believed by many ophthalmologists to represent the earliest phase of glaucoma.
Many of the drugs formerly used to treat glaucoma proved not entirely satisfactory. Indeed, few advanes were made in the treatment of glaucoma since pilocarpine and physostigmine were introduced. Only recently have clinicians noted that many β-adrenergic blocking agents are effective in reducing intraocular pressure. While many of these agents are effective in reducing intraocular pressure, they also have other characteristics, e.g. membrane stabilizing activity, that are not acceptable for chronic ocular use. (S)-1-tert-Butylamino-3[(4-morpholino-1,2,5-thiadiazol-3yl)oxy]-2-propanol, a β-adrenergic blocking agent, was found to reduce intraocular pressure and to be devoid of many unwanted side effects associated with pilocarpine and, in addition, to possess advantages over many other β-adrenergic blocking agents, e.g. to be devoid of local anesthetic properties, to have a long duration of activity, and to display minimal tolerance.
Although pilocarpine, physostigmine and the β-blocking agents mentioned above reduce intraocular pressure, none of these drugs manifests its action by inhibiting the enzyme carbonic anhydrase and, thereby, impeding the contribution to aqueous humor formation made by the carbonic anhydrase pathway.
Agents referred to as carbonic anhydrase inhibitors, block or impede this inflow pathway by inhibiting the enzyme, carbonic anhydrase. While such carbonic anhydrase inhibitors are now used to treat intraocular pressure by oral, intravenous or other systemic routes, they thereby have the distinct disadvantage of inhibiting carbonic anhydrase throughout the entire body. Such a gross disruption of a basic enzyme system is justified only during an acute attack of alarmingly elevated intraocular pressure, or when no other agent is effective. Despite the desirability of directing the carbonic anhydrase inhibitor only to the desired ophthalmic target tissue, no topically effective carbonic anhydrase inhibitors are available for clinical use.
However, topically effective carbonic anhydrase inhibitors are reported in U.S. Pat. Nos. 4,386,098; 4,416,890; 4,426,388; and 4,668,697, where the compounds reported therein are 5 (and 6)-hydroxy-2-benzothiazole-sulfonamides and acyl esters thereof and 5-(and 6)-hydroxy-2-sulfamoylbenzothiophenes and esters thereof, U.S. Pat. No. 4,677,115, where the compounds are reported to be 5,6-dihydro-thienothiophene sulfonamides, U.S. Pat. No. 4,798,831 where the compounds are reported to be thienofuran sulfonamides and U.S. Pat. No. 4,806,562 where the compounds are reported to be alkylenethienothiophene sulfonamides.
DETAILED DESCRIPTION OF THE INVENTION
The novel compounds of this invention have structural formula: ##STR2## or an ophthalmologically or pharmaceutically acceptable salt thereof, wherein
R 1 and R 2 are independently selected from hydrogen or C 1-6 straight or branched alkyl, either unsubstituted or substituted with one or more groups chosen from:
amino;
(C 1-6 alkyl)amino;
di(C 1-3 alkyl)amino;
di[(C 1-3 alkoxy)-C 2-4 alkyl]amino;
di[(C 1-3 alkoxy)-C 2-4 alkyl]amino;
[C 1-3 alkoxy-(C 2-4 alkoxy) n ](C 2-6 alkyl)amino,
wherein n=1-4;
di[C 1-3 alkoxy-(C 2-4 alkoxy) n ](C 2-6 alkyl)-amino, wherein n=1-4;
[C 1-3 alkoxy-(C 2-4 alkoxy) n ][C 1-3 -alkoxy) m ](C 1-6 alkyl)amino,
wherein n and m=1-4;
C 1-4 alkoxy;
C 1-4 alkoxy-(C 2-4 alkoxy) n , wherein n=1-4;
C 1-6 alkylamino-(C 2-4 alkoxy) n , wherein n=1-4;
di(C 1-6 alkyl)amino-C 2-4 alkoxy) n wherein n=1-4;
amino-(C 2-4 alkoxy) n wherein n=1-4; hydroxy;
C 1-3 alkylthio;
C 1-3 alkylsulfonyl;
C 1-3 alkylsulfinyl;
morpholino;
thiomorpholino;
thiomorpholino-S-oxide;
thiomorpholino-S-dioxide; ##STR3## provided that no more than one heteroatom is bonded to any one carbon.
Preferred species of the invention are:
5-[N-(2,2-Dimethylaminoethyl)carbamoyl]thieno[2,3-b]-thiophene-2-sulfonamide;
5-(N-Methylcarbamoyl)thieno[2,3-b]thiophene-2-sulfonamide;
5-(N-Methoxyethoxypropylcarbamoyl)thieno[2,3-b]-thiophene-2-sulfonamide;
5-[N-(3-Oxo-3-thia-n-butyl)carbamoyl]thieno[2,3-b]-thiophene-2-sulfonamide;
5-[N-(2,3-Dihydroxypropyl)carbamoyl]thieno[2,3-b]-thiophene-2-sulfonamide;
5-[N,N-Bis(Hydroxyethyl)carbamoyl]thieno[2,3-b]-thiophene-2-sulfonamide;
5-[N-2-(N'-Morpholino)ethylcarbamoyl]thieno[2,3-b]-thiophene-2-sulfonamide;
5-[N-2-(N'-Thiomorpholino)ethylcarbamoyl]thieno[2,3-b]thiophene-2-sulfonamide;
5-{N-[N',N'-Bis(2-Methoxyethyl)aminoethyl]carbamoyl}-thieno[2,3-b]thiophene-2-sulfonamide;
and pharmaceutically acceptable salts thereof.
The processes for preparing the novel compounds of the invention are shown by the following schematic illustration: ##STR4##
5-Methoxycarbonylthieno[2,3-b]thiophene-2-sulfonamide, a key intermediate for many of the novel compounds of this invention, is obtained by adding methylthieno[2,3-b]thiophene-2-carboxylate to a mixture of phosphorus pentachloride and chlorosulfonic acid to yield 5-methoxycarbonylthieno[2,3-b]thiophene-5-sulfonylchloride. This latter compound is then dissolved in an inert organic solvent and added dropwise to an excess of ammonium hydroxide with stirring. 5-Methoxycarbonylthieno[2,3-b]thiophene-2-sulfonamide is obtained by evaporating the excess ammonia and solvent.
The preferred process for preparing compounds of this invention wherein R 1 and/or R 2 is alkyl comprises heating 5-methoxycarbonylthieno[2,3-b]thiophene-2-sulfonamide suspended in alcohol or equivalent solvent in the presence of an alkylamine under pressure for 1 to 72 hours, preferably about 20 hours, until the reaction is substantially completed. The mixture is then cooled and the excess solvent (and ammonia, if any) may be evaporated in vacuo.
The preferred process for preparing compounds of this invention wherein R 1 and/or R 2 is alkoxyalkyl comprises refluxing 5-methoxycarbonylthieno[2,3-b]thiophene-2-sulfonamide and an alkoxyalkylamine in alcohol for 1 to 240 hours, preferably in the range of 90 to 100 hours. After cooling, the excess solvent may be evaporaed in vacuo.
Crystallization may be achieved by any of a number of suitable methods. In the preparation of 5-(methylamino)carbonylthieno[2,3-b]thiophene-2-sulfonamide, trituration of the reaction product with methanol and drying has been found to be effective. In the preparation of 5-(N-methoxyethoxypropylcarbamoyl)thieno[2,3-b]thiophene-2-sulfonamide, addition of ether to the resulting product and recrystallization of the final compound from 1,2-dichloroethane has been found effective.
The hydrochloride salts of this invention are prepared by reacting a 5-carbamoylthieno-[2,3-b]thiophene-2-sulfonamide having a basic substituent dissolved in alcohol with a solution of hydrochloric acid in alcohol. Crystallization may be achieved by any suitable method. In the preparation of 5-[N-(2,2-dimethylaminoethyl)]carbamoylthieno[2,3-b]thiophene-2-sulfonamide hydrochloride, crystallization has been successfully achieved by scratching and cooling the solution for several hours.
For use in treatment of conditions relieved by the inhibition of carbonic anhydrase, the active compound can be administered either systemically, or, in the treatment of the eye, topically. The dose administered can be from as little as 0.1 to 25 mg or more per day, singly, or preferably on a 2 to 4 dose per day regimen although a single dose per day is satisfactory.
When adminstered for the treatment of elevated intraocular pressure or glaucoma, the active compound is most desirably administered topically to the eye, although systemic treatment is, as indicated, also possible.
When given systemically, the drug can be given by any route, although the oral route is preferred. In oral administration, the drug can be employed in any of the usual dosage forms such as tablets or capsules, either in a contemporaneous delivery or sustained release form. Any number of the usual excipients or tableting aids can likewise be included.
When given by the topical route, the active drug or an ophthalmologically acceptable salt thereof such as the hydrochloride salt is formulated into an opthalmic preparation. In such formulations, from 0.1% to 15% by weight can be employed. The objective is to administer a dose of from 0.1 to 1.0 mg per eye per day to the patient, with treatment continuing so long as the condition persists.
Thus, in an ophthalmic solution, insert, ointment or suspension for topical delivery, or a tablet, intramuscular, or intravenous composition for systemic delivery, the active medicament or an equivalent amount of a salt thereof is employed, the remainder being carrier, excipients, preservatives and the like as are customarily used in such compositions.
The active drugs of this invention are most suitably administered in the form of ophthalmic pharmaceutical compositions adapted for topical administration to the eye such as a suspension, ointment, or as a solid insert. Formulations of these compounds may contain from 0.01 to 15% and especially 0.5% to 2% of medicament. Higher dosages as, for example, about 10%, or lower dosages can be employed provided the dose is effective in reducing or controlling elevated intraocular pressure. As a unit dosage from between 0.001 to 10.0 mg, preferably 0.005 to 2.0 mg, and especially 0.1 to 1.0 mg of the compound is generally applied to the human eye, generally on a daily basis in single or divided doses so long as the condition being treated exists.
These hereinbefore described dosage values are believed accurate for human patients and are based on the known and presently understood pharmacology of the compounds, and the action of other similar entities in the human eye. They reflect the best mode known. As with all medications, dosage requirements are variable and must be individualized on the basis of the disease and the response of the patient.
The pharmaceutical preparation which contains the active compound may be conveniently admixed with a non-toxic pharmaceutical organic carrier, or with a non-toxic pharmaceutical inorganic carrier. Typical of pharmaceutically acceptable carriers are, for example, water, mixtures of water and water-miscible solvents such as lower alkanols or arylalkanols, vegetable oils, polyalkylene glycols, petroleum based jelly, ethyl cellulose, ethyl oleate, carboxymethylcellulose, polyvinylpyrrolidone, isopropyl myristate and other conventionally employed acceptable carriers. The pharmaceutical preparation may also contain non-toxic auxiliary substances such as emulsifying, preserving, wetting agents, bodying agents and the like, as for example, polyethylene glycols 200, 300, 400 and 600, carbowaxes 1,000, 1,500, 4,000, 6,000 and 10,000, antibacterial components such as quaternary ammonium compounds, phenylmercuric salts known to have cold sterilizing properties and which are non-injurious in use, thimerosal, methyl and propyl paraben, benzyl alcohol, phenyl ethanol, buffering ingredients such as sodium chloride, sodium borate, sodium acetates, gluconate buffers, and other conventional ingredients such as sorbitan monolaurate, triethanolamine, oleate, polyoxyethylene sorbitan monopalmitylate, dioctyl sodium sulfosuccinate, monothioglycerol, thiosorbitol, ethylenediamine tetraacetic acid, and the like. Additionally, suitable ophthalmic vehicles can be used as carrier media for the present purpose including conventional phosphate buffer vehicle systems, isotonic boric acid vehicles, isotonic sodium chloride vehicles, isotonic sodium borate vehicles and the like.
The pharmaceutical preparation may also be in the form of a solid insert such as one which after dispensing the drug remains essentially intact, or a bio-erodible insert that is soluble in lacrimal fluids, or otherwise disintegrates.
EXAMPLE 1
5-[N-(2,2-Dimethylaminoethyl)carbamoyl]thieno-[2,3-b]thiophene-2-sulfonamide ##STR5##
Step A: Preparation of 5-Methoxycarbonylthieno-[2,3-b]thiophene-2-sulfonylchloride
Crystals of phosphorus pentachloride (9.80 g., 47.1 mmoles) were added in portions to chlorosulfonic acid (9 ml., 15.4 g., 132 mmoles) in an inert atmosphere. The solution was stirred for 15 minutes. To this solution small portions of methyl thieno[2,3-b]thiophene-2-carboxylate (8.49 g., 42.8 mmoles) were slowly added, allowing for subsiding of effervescence between additions. After the addition was complete, the solution was stirred in an inert atmosphere for 25 minutes. The resulting solution was poured carefully onto ice-water. The resulting mixture was triturated and the off-white crystals were collected and washed with water and dried in vacuo over phosphorus pentoxide to give 11.58 g of 5-methoxycarbonylthieno[2,3-b]thiophene-2-sulfonylchloride. This was used in the next step without purification.
Step B: Preparation of 5-Methoxycarbonylthieno[2,3-b]thiophene-2-sulfonamide
To stirred ammonium hydroxide (150 ml) was added dropwise 5-methoxycarbonylthieno[2,3-b]thiophene-2-sulfonyl chloride (11.58 g. 39.02 mmoles) dissolved in acetone (140 ml). After the addition was complete, the solution was stirred for 30 minutes. The reaction was worked up by evaporating the ammonia and acetone in vacuo. The crystals were collected and dried (9.66 g.) (89%). Recrystallization from nitromethane gave 7.02 g. mp 219°-220° C.
Calc. for C 8 H 7 NO 4 S 3 : C, 34.65; H, 2.54; N, 5.05. Found: C, 35.00; H, 2.51; N, 5.20.
Step C: Preparation of 5-[N-(2,2-Dimethylaminoethyl)-carbamoyl]thieno[2,3-b]thiophene-2-sulfonamide
5-Methoxycarbonylthieno[2,3-b]thiophene-2-sulfonamide (0.55 g., 2 mmoles) was suspended in methanol (5 ml). N,N-dimethylaminoethylamine (0.53 g., 2 mmoles) was added and the mixture refluxed for 3 days. The mixture was cooled in an ice-water bath and the product collected and washed with cold methanol. The dried product weighed 0.45 g. which was used directly to make the HCl salt.
Step D: Preparation of 5-[N-(2,2-Dimethylaminoethyl)carbamoyl]thieno[2,3-b]thiophene-2-sulfonamide hydrochloride
5-[N-(2,2-Dimethylaminoethyl)carbamoyl]thieno[2,3-b]thiophene-2-sulfonamide (0.45 g., 1.35 mmole) was dissolved in hot ethanol (100 ml) filtered and cooled. To this solution was added 0.265 ml of 5.10M HCl in methaol. The resulting solution was stirred and scratched then cooled in a refrigerator overnight. The resulting crystalline product, 0.46 g., mp 254°-255° C. (D), was collected and dried.
EXAMPLE II
5-(N-Methylcarbamoyl)thieno[2,3-b]thiophene-2-sulfonamide ##STR6##
5-Methoxycarbonylthieno[2,3-b]thiophene-2-sulfonamide (1.11 g., 4 mmol) and 3.60M. methylamine in methanol (20 mL., 2 mmole) were heated in a pressure bomb at 60° C. bath temperature for 20 hours. The mixture was cooled to room temperature and the excess methylamine and methanol were evaporated in vacuo. The resulting solid was triturated with methanol and dried to give 1.06 g. of 5-(N-methylcarbamoyl)thieno[2,3-b]thiophene-2-sulfonamide. m.p. 272°-273° C.
Calc. for C 8 H 8 N 2 O 3 S: C, 34.77; H, 2.92; N, 10.14. Found: C, 34.77; H, 2.88; N, 10.11.
EXAMPLE III
5-(N-Methoxyethoxypropylcarbamoyl)thieno[2,3-b]thiophene-2-sulfonamide ##STR7##
5-Methoxycarbonylthieno[2,3-b]thiophene-2-sulfonamide (0.55 g., 2 mmoles) and 3-(methoxyethoxy)propylamine (0.80 g., 6 mmoles) were refluxed in methanol (5 mL) for 96 hours. The solution was cooled and evaporated in vacuo to remove most of the methanol. Ether was added and the resulting product was recrystallized from 1,2-dichloroethane to give 0.49 g of 5-(N-methoxyethoxypropylcarbamoyl)thieno[2,3-b]thiophene-2-sulfonamide, m.p. 154°-155° C.
Calc. for C 13 H 17 N 2 O 5 S 3 : C, 41.36; H, 4.54; N, 7.42. Found: C, 41.40; H, 4.75; N, 7.40.
EXAMPLE IV
5-[N,N-Bis(Hydroxyethylcarbamoyl)]thieno[2,3-b]thiophene-2-sulfonamide ##STR8##
5-Methoxycarbonylthieno[2,3-b]thiophene-2-sulfonamide (1.11 g., 4 mmoles); bis(hydroxyethyl)amine (2.10 g., 20 mmoles); and anhydrous bis(methoxyethyl)ether (5 mL) were heated at bath temperatures of 110° to 120° C. for 6 hours. The reaction was cooled to room temperature and poured into water (20 mL). Concentrated hydrochloric acid was added until strongly acidic. The mixture was extracted with ethyl acetate five times. The combined ethyl acetate extracts were washed with water, dried (MgSO 4 ) filtered and the solvent removed in vacuo to leave a solid which was washed by decantation three times with ether. This crude material was chromatographed on a 50×150 mm column of silica gel eluting with 10% methanol in chloroform, to give 0.44 g of product, which was further purified by HPLC (waters C-18; 30×6.39; buffer 1 mL H 3 PO 4 /liter of water) reverse phase to give 0.16 g of pure 5-[N,N-Bis(hydroxyethylcarbamoyl)]thieno[2,3-b]thiophene-2-sulfonamide, m.p. 155°-156° C.
Calc. for C 11 H 14 N 2 O 5 S 3 : C, 37.70; H, 4.03; N, 7.99. Found: C, 37.31; H, 3.81; N, 7.84.
EXAMPLE V
5-(N-2,3-Dihydroxypropylcarbamoyl)thieno[2,3-b]thiophene-2-sulfonamide ##STR9##
5-Methoxycarbonylthieno[2,3-b]thiophene-2-sulfonamide (0.83 g., 3 mmoles) and 2,3-dihydroxypropylamine (1.37 g., 15 mmoles) were dissolved in hot methanol and refluxed for 48 hours. The reaction was worked up by evaporating the methanol in vacuo. Water (7 mL) was added followed by the dropwise addition of conc. HCl until strongly acidic (˜1.8 pH). The product crystallized out and was collected, washed with water and dried to give 0.90 g of crude product. Recrystallization from nitromethane gave 0.73 g of 5-(N-2,3-dihydroxypropylcarbamoyl)thieno[2,3-b]thiophene-2-sulfonamide, m.p. 117°-118° C.
EXAMPLE VI
5-[N-(3-Oxo-3-thia-n-butyl)carbamoyl]thieno[2,3-b]thiophene-2-sulfonamide ##STR10##
Step A: 5-[N-(3-Thia-n-butyl)carbamoyl]thieno[2,3-b]thiophene-2-sulfonamide
5-Methoxycarbonylthieno[2,3-b]thiophene-2-sulfonamide (1.11 g., 4 mmoles), 2-thia-n-butylamine (2.92 g., 32 mmoles) and methanol were refluxed with stirring for 5 days. The solution was cooled in the freezer for 2 hours and the product was filtered off to yield 1.10 g of 5-[N-(3-thia-n-butyl)carbamoyl]thieno[2,3-b]thiophene-2-sulfonamide which was used in the next step without further purification.
Step B: 5-[N-(3-Oxo-3-thia-n-butyl)carbamoyl]thieno[2,3-b]thiophene-2-sulfonamide
Sodium periodate (1.40 g., 6.54 mmoles) was dissolved in water (20 mL). THF (20 mL) was added followed by 5-[N-(3-thia-n-butyl)carbamoyl]thieno[2,3-b]thiophene-2-sulfonamide (1.10 g., 3.27 mmoles) were stirred at room temperature under Argon for 24 hours. The solution was filtered and then stripped of the THF and all but 2-2 mL of water. The product was then crystallized, collected and dried. Recrystallization from nitromethane gave 1.0 g. of 5-[N-(3-oxo-3-thia-n-butyl)carbamoyl]thieno[2,3-b]thiophene-5-sulfonamide, mp 242°-243° C.
Calc. for C 10 H 12 N 4 O 4 S 4 : C, 34.08; H, 3.43; N, 7.95. Found: C, 34.36; H, 3.23; N, 8.12.
EXAMPLE VII
5-[N-2-(N'-Morpholino)ethylcarbamoyl]thieno[2,3-b]thiophene-2-sulfonamide hydrochloride ##STR11##
Step A: 5-[N-2-(N'-Morpholino)ethylcarbamoyl]thieno[2,3-b]thiophene-2-sulfonamide
A mixture of 5-Methoxycarbonylthieno[2,3-b]thiophene-2-sulfonamide (0.83 g., 3 mmoles), 2-[N-(morpholino)]ethylamine (1.17 g., 9 mmoles) and methanol (4 mL) was refluxed for 72 hours. The methanol was evaporated in vacuo and the residue dissolved in hot THF. The product was adsorbed onto silica gel and the chromatographed product eluted with 10% methanol in chloroform to give 1.37 g of product.
Step B: 5-[N-2-(N'-Morpholino)ethylcarbamoyl]thieno[2,3-b]thiophene-2-sulfonamide hydrochloride
5-[N-2-(N'-Morpholino)ethylcarbamoyl]thieno[2,3-b]thiophene-2-sulfonamide (1.07 g., 2.04 mmole) was dissolved in hot methanol (150 mL) and ethanol (150 mL). This solution was cooled to room temperature, mixed with cold 5.62M HCl in ethanol (0.51 mL, 2.8 mmoles), and allowed to stand for 15 minutes. The mixture was filtered and boiled down to 100 mL. 150 mL of ethanol was added and the solution was boiled down to 100 ml again. This was repeated and allowed to crystallize to give 0.87 g of product, mp 267°-268° C. (D).
EXAMPLE VIII
5-[N-2-(N'-Thiomorpholino)ethylcarbamoyl]thieno[2,3-b]thiophene-2-sulfonamide hydrochloride ##STR12##
Step A: 5-[N-2-(N'-Thiomorpholino)ethylcarbamoyl]thieno[2,3-b]thiophene-2-sulfonamide
A mixture of 5-Methoxycarbonylthieno[2,3-b]thiophene-2-sulfonamide (0.83 g., 3 mmoles), 2-[N-(thiomorpholino)]ethylamine (1.17 g., 9 mmoles) and methanol (4 mL) was refluxed for 72 hours. The methanol was evaporated in vacuo and the residue dissolved in hot THF. The product was then adsorbed onto silica gel and the product eluted with 10% methanol in chloroform to give 1.37 g of product.
Step B: 5-[N-2-(N'-Thiomorpholino)ethylcarbamoyl]thieno[2,3-b]thiophene-2-sulfonamide hydrochloride
5-[N-2-(N'-Thiomorpholino)ethylcarbamoyl]thieno[2,3-b]thiophene-2-sulfonamide (1.07 g., 2.04 mmole) was dissolved in hot methanol (150 mL) and ethanol (150 mL). This solution was cooled to room temperature, mixed with cold 5.62M HCl in ethanol (0.51 mL, 2.8 mmoles), and allowed to stand for 15 minutes. The mixture was filtered and boiled down to 100 mL. 150 mL of ethanol was added and the solution was boiled down to 100 ml again, to give 0.87 g of product, mp 214°-215° C. (D).
EXAMPLE IX
5-{N-[(N',N'-Bis(2-Methoxyethyl)aminoethyl]carbamoyl}thieno[2,3-b]thiophene-2-sulfonamide hydrochloride ##STR13##
Step A: 5-{N-[(N',N'-Bis(2-Methoxyethyl)aminoethyl]carbamoyl}thieno[2,3-b]thiophene-2-sulfonamide
A mixture of 5-Methoxycarbonylthieno[2,3-b]thiophene-2-sulfonamide (0.83 g., 3 mmoles), N,N-Bis(2-Methoxyethyl)aminoethylamine(1.17 g., 9 mmoles) and methanol (4 mL) was refluxed for 72 hours. The methanol was evaporated in vacuo and the residue dissolved in hot THF. The product was then adsorbed onto silica gel, and the chromatographed product eluted with 10% methanol in chloroform to give 1.37 g of product.
Step B: 5-{N-[(N',N'-Bis(2-Methoxyethyl)aminoethyl]carbamoyl}thieno[2,3-b]thiophene-2-sulfonamide hydrochloride
5-{N-[N',N'-Bis(2-Methoxyethyl)aminoethyl]carbamoyl}thieno[2,3-b]thiophene-2-sulfonamide (1.07 g., 2.04 mmole) was dissolved in hot methanol (150 mL) and ethanol (150 mL). This solution was cooled to room temperature, mixed with cold 5.62M HCl in ethanol (0.51 mL, 2.8 mmoles) and allowed to stand for 15 minutes. This solution was then filtered and boiled down to 100 mL. 150 mL of ethanol was added and the resulting solution was boiled down to 100 ml. This step was repeated and crystallization yielded 0.87 g of product, mp 75°-80° C. (D).
Using similar reaction methods to those described in detail above, compounds of formula I having the following substituents are prepared:
__________________________________________________________________________ ##STR14##R.sub.1 R.sub.2__________________________________________________________________________ ##STR15##H ##STR16##H ##STR17##H ##STR18##H ##STR19##H ##STR20##CH.sub.3 ##STR21##CH.sub.3 ##STR22##CH.sub.3 ##STR23##CH.sub.2 CH.sub.2 OH ##STR24##(CH.sub.2).sub.2 O(CH.sub.2).sub.2 OCH.sub.3 CH.sub.2 CH.sub.2 NH(CH.sub.2 CH.sub.2 OC.sub.3 H.sub.7)(CH.sub.2).sub.2 O(CH.sub.2).sub.2 NHCH.sub.3 H(CH.sub.2).sub.2 O(CH.sub.2).sub.3 N(CH.sub.3)(CH.sub.2 CH.sub.2 OCH.sub.3) CH.sub.2 CH.sub.2 CH.sub.2 NH.sub.2(CH.sub.2).sub.2 SO.sub.2 CH.sub.3 ##STR25## ##STR26## H ##STR27## ##STR28##H ##STR29## ##STR30## ##STR31##__________________________________________________________________________ | Novel 5-carbamoylthieno[2,3-b]thiophene-2-sulfonamides and derivatives thereof are prepared in reactions of 5-methoxycarbonylthieno-[2,3-b]thiophene-2-sulfonamide with alkylamines, alkoxyalkylamines and hydroxyalkylamines. These compounds are useful for the treatment of elevated intraocular pressure in compositions including ophthalmic drops and inserts. | 2 |
CROSS REFERENCE TO RELATED APPLICATIONS
This application is a continuation of application Ser. No. 760,783, filed July 31, 1985, now abandoned.
FIELD OF THE INVENTION
The present invention relates to an apparatus for the release of a storage vessel from a riser. More particularly, the present invention relates to a connector for the quick-release of a floating storage vessel from the riser of a single-anchor-leg-mooring system.
BACKGROUND OF THE INVENTION
In the offshore production of oil and natural gas, floating vessels are frequently used to temporarily store the hydrocarbons prior to shipment to onshore production and refining facilities. The hydrocarbons are produced from an offshore structure which is usually anchored to the seafloor with piling or from a subsea production system (SPS). In both cases, the hydrocarbons are shipped, usually via a pipeline, to an offshore floating terminal which is occasionally referred to as a single-anchor-leg-mooring (SALM) system. A typical SALM is comprised of a base structure which is positioned on the marine bottom and a riser which is connected to the base structure and extends above the water surface. At the upper end of the riser is attached an articulated mooring arm which in turn is connected to a floating storage vessel. Usually, the floating vessel is a converted tanker and is permanently moored to the riser via the articulated mooring arm. The pipeline, which carries the hydrocarbons from the offshore structure or SPS, continues up along the riser and across the articulated mooring arm into the storage compartments of the floating vessel. Shuttle tankers then offload the hydrocarbons from the floating vessel for transportation to onshore facilities.
In an offshore environment the articulated mooring arm must be sufficiently flexible to accommodate the movement of the vessel relative to the riser. As the vessel is acted upon by forces induced by winds, waves, ice masses, ocean currents, etc., the vessel will roll, pitch and heave. In addition, the vessel will yaw about its mooring point as the direction of the forces vary.
During an emergency condition such as the arrival of a hurricane or ice masses, it may be necessary to effect a quick disconnection of the vessel from the riser. The emergency situation is aggravated by the fact that the disconnection must occur quickly enough to prevent damage to the vessel, articulated mooring arm, and riser. Once disconnected, the movement of the vessel forward into the articulated mooring arm as a result of sea movement can cause significant damage to the vessel, articulated mooring arm, and riser.
Accordingly, the need exists for an improved apparatus which effects the quick and accurately-timed disconnection of a floating storage vessel from the riser of an SALM in a manner which permits an operator time to safely reverse the vessel away from the riser before any contact is made.
SUMMARY OF THE INVENTION
Generally, the present invention is a quick-release connector for securing two offshore mooring sections of an articulated mooring arm which connect an offshore floating storage vessel to the riser of an SALM.
More precisely, the connector comprises a pin member in direct engagement with a latch member having a hook adapted for rotational movement about the pin member. The connector also includes a plunger which is capable of advancing from one position wherein the latch member is locked around the pin member and rotational movement is prohibited to another position wherein the plunger is displaced from the hook and the latch member is permitted to rotate around the pin member. The connector also includes means for displacing the plunger between the two positions and means for rotating the latch member about the pin member so that the vessel may quickly reversed and displaced from the riser before contact occurs.
The more important features of the present invention have been summarized rather broadly in order that the detailed description which follows may be better understood. There are, of course, additional features of the present invention which will be described hereinafter and which will also form the subject of the claims appended hereto.
DETAILED DESCRIPTION OF THE DRAWINGS
In order to more fully understand the drawings used in the detailed description of the present invention, a brief description of each figure is provided.
FIG. 1 is an isometric view of an SALM attached to an offshore floating storage vessel by means of an articulated mooring arm.
FIG. 2A is a plan view of the articulated mooring arm showing the present invention.
FIG. 2B is an elevation view of the articulated mooring arm showing the present invention.
FIG. 3 is a cross-sectional view taken along line 3--3 of FIG. 2B.
FIG. 4 is a detailed elevation view of the present invention showing the connector in an open position.
FIG. 5 is a detailed elevation view of the present invention showing the connector in a closed position.
DETAILED DESCRIPTION OF THE INVENTION
Referring now to FIG. 1, an SALM 10 is shown having a base structure 12 positioned on the marine bottom 14 and a riser 16 connected to the base structure and extending above the water surface 18. An articulated mooring arm 20 is attached at one end to the top of the riser and at its other end to the bow 22 of an offshore floating storage vessel 24. A shuttle tanker 26 is temporarily moored to the stern 28 of the vessel 24 and is unloading hydrocarbons from the vessel 24 by means of an offshore loading system 30.
With reference to FIGS. 2A and 2B, the mooring arm 20 is attached at one end 32 to the riser 16 and at its other end 34 to the bow 22 of the vessel 24. Generally, the articulated mooring arm 20 has a truss framework with interconnecting crossbraces 36 for added rigidity. The mooring arm is usually attached to the bow 22 of the vessel 24 with a pin arrangement 38 which provides a hinge connection permitting the arm 20 to rotate about the pin arrangement 38 in a vertical plane 40. Furthermore, the mooring arm 20 includes a roll shaft 21 to accomodate roll of vessel 10 about its longitudinal axis. Such pin arrangement 38 and roll shaft 21 are well know to those skilled-in-the art.
Attached at approximately mid-span of the articulated mooring arm are gusset plates 42 and a sheave 44. Sheave 44 would be supported between the plates 42 on a pin (not shown). A similar sheave 46 is located at the top of a brace assembly 48 which is attached to the deck 50 at the bow 22. The sheaves 44 and 46 are interconnected by a hoisting line 52 which has one end connected to a bracket 49 on brace assembly 48 and the other end connected to a winch 54. The sheaves 44, 46, hoisting line 52, winch 54, and brace assembly 48 are all part of a hoisting system for rotating the mooring arm 20 about the pin arrangement 38. Thus, it will be obvious based on this disclosure that the hoisting system is used to control and maneuver the mooring arm 20 during the attachment to or disengagement from the riser 16.
With reference to FIGS. 3, 4 and 5 also, a pin member 56 is located near the top of the riser 16. It is connected to the riser by means of gusset plates 58 which are attached at each end of the pin member 56 and extend back to a mooring swivel 60. Such mooring swivels 60 are well known to those skilled-in-the-art, see for example U.S. Pat. Nos. 4,362,325 and 4,391,298. The gusset plates 58 include a tapered portion 62 for guiding the engaging portion of the present invention onto the pin member 56, as described below. For purposes of the present invention, the gusset plates 58 may be regarded as a first mooring section while the mooring arm 20 may be regarded as a second mooring section.
With particular reference to FIGS. 4 and 5, the present invention includes a latch member 64 having a hook 66 at one end. The hook 66 is adapted to engage the pin member 56. The latch member 64 is connected at its upper end 68 by means of a clevis 69 which is attached to a hydraulic cylinder 70. Activation of the hydraulic cylinder 70 advances a piston rod 72 which rotates the latch member 64 about the pin member 56 once it is engaged. The latch member is restrained laterally by bearings 74 (see FIG. 3). The bearings 74 have a substantially circumferential lip 76 for vertically supporting the latch member. The latch member and the bearings 74 are attached to end 32 of the mooring arm 20 by vertical plates 78.
The present invention also includes a plunger 80 which is supported between the vertical plates 78 by crossbars 82. The plunger is adapted for axial displacement by means of a hydraulic cylinder 86. Once actuated, the hydraulic cylinder 86 advances a piston rod 88 which is attached to the plunger 80. In this manner, the plunger is capable of moving from a first position (as shown in FIG. 4) wherein the end 90 of the plunger is displaced from the interior or open region 92 of the hook 66 to a second position (as shown in FIG. 5) wherein the end 90 of the plunger is located within the open region of the hook.
In the operaion of the present invention, the mooring arm 20 is initially lowered via the hoisting system from a substantially vertical position (not shown) to a substantially horizontal position as generally shown in FIG. 2B. The latch member 64 is maintained in an open position as shown in FIG. 4, during engagement with the pin member 56. Once the hook 66 contacts the pin member 56, hydraulic cylinder 70 is actuated advancing piston rod 72 and thereby displacing the upper end 68 of the latch member. This rotates the latch member in a counterclockwise direction with respect to FIGS. 4 and 5. Once the piston 72 is fully extended and the hook 66 has completely rotated around the pin member, the hydraulic cylinder 86 is actuated advancing the piston rod 88 and thereby the plunger 80 from a first or open position as shown in FIG. 4 to a second or closed (locked) position as shown in FIG. 5. Once the piston 88 is fully extended, the end of the plunger is located within the open region 92 of the hook. This prevents any further rotational movement of the latch member, effectively locking the hook and latch member around the pin member and preventing the release of the mooring arm from the riser or the disconnection of the first mooring section from the second mooring section.
To quickly disengage the mooring arm from the top of the riser, hydraulic cylinder 86 is actuated retracting piston rod 88 and, therefore, the plunger from the closed position of FIG. 5 to the open position of FIG. 4. Hydraulic cylinder 70 is then actuated retracting piston 72 and, therefore, rotating the latch member in a clockwise direction (as shown in FIGS. 4 and 5) to the open position. The hoisting system is then actuated and the mooring arm is raised, thereby completely freeing the mooring arm from the riser.
By selecting the proper sizes of hydraulic cylinders based on the dimensions of the latch member, pin member and plunger, it is possible to initiate the lateral displacement of the plunger and rotation of the latch member within seconds. Such a selection of the proper sizes of hydraulic cylinders is well know to those skilled-in-the-art based on this disclosure. Similarly, it is possible to activate the hoisting system and displace the end of the mooring arm from the top of the riser within moments of the commencement of an emergency condition. The vessel would be made ready beforehand for lateral displacement with respect to the top of the riser to prevent contact between the bow of the vessel and the riser once disconnected. This could be accomplished by tugs or another vessel suitable for movement of the storage vessel to a safe harbor pending the duration of the emergency condition.
The present invention has been describe in terms of various embodiments. Obviously, many modifications and alterations based on the above disclosure will be apparent to those skilled-in-the-art. It is, therefore, intended to cover all such equivalent modifications and variations which fall within the spirit and scope of the claims appended hereto. | An apparatus is described for securing two offshore mooring sections together. The apparatus is a connector adapted to quickly disengage each mooring section so that an offshore floating storage vessel, having one mooring section attached to it, may be separated from the riser of an single-anchor-leg-mooring system, having the other mooring section attached to it. The connector comprises a pin member engageable with a hook of a latch member. The latch member is rotated once the hook engages the pin member and a plunger then advances into an open region of the hook prohibiting the rotational movement of the latch member and thereby locking the two mooring sections together. | 8 |
CROSS-REFERENCES TO RELATED APPLICATIONS
Not applicable
STATEMENT REGARDING FEDERALLY SPONSORED RESEARCH OR DEVELOPMENT
Not applicable
BACKGROUND
Air purification respirators (“APRs”), commonly referred to as “gas masks,” are in wide private and military use. APRs are wearable filtering devices used to create an envelope of clean air around at least a wearer's nose and mouth, providing protection to the wearer from the inhalation of undesired or harmful dust, fumes, vapors, or other gases.
APRs have multiple applications, particularly in the industrial and military fields. APRs are used in industry to protect workers from airborne industrial hazards such as fumes, gasses, dust, and particulate matter. Representative industrial uses would include in paint booths, grain storage facilities, and laboratories. In the military, APRs are employed to protect personnel who may be exposed to attack by poison gas or other airborne toxins.
APRs are generally manufactured in the form of a mask that covers at least the wearer's mouth and nose. APRs can include additional protective surfaces to guard the wearer's eyes, ears, facial skin, or even hair. When properly fitted and worn by a wearer, an APR creates an envelope of clean air within the APR by, in part, forming a seal between the APR and the wearer's face that substantially prohibits the entry of air from the outside environment. As a result, the air breathed by the wearer during use of the APR is, except for minimal leakage through the facial seal, the intake ports, or the exhalation valve, air that has been cleaned by filters connected to the APR intake ports or air that has been provided directly from a known clean air source such as an air tank.
APRs generally have one or more intake ports, usually disposed towards the sides of the mask apparatus. A filter apparatus or canister can be fitted into the intake port, usually by a sealing threaded connection or a sealing press-fit connection. Both filter ports can be fitted with filter apparatuses, or one can be so fitted and the other sealed shut with a threaded cap. This general modularity allows filters to be changed quickly and conveniently, and allows different filtering apparatus to be installed to optimize an APR for different environments. The ability to quickly replace filters also reduces cost by allowing the same APR mask body to be re-used even if the filters have to be replaced or changed. Alternatively, one or both intake ports can be coupled to a hose leading to a known clean air source, such as an air take.
APRs generally include a means to allow the wearer's exhaled breath to escape, most typically an outlet port disposed on a central portion of the mask. The outlet port of the APR typically comprises a port, generally round in shape, disposed over the area of the wearer's mouth. In many APRs in common use, this port includes one-way valve assembly, such as a flap valve, configured to allow air to escape from the APR during the wearer's exhalation, but which prevents air from the outside environment from entering the APR during inhalation. This one-way valve assembly is often removable via a sealing snap-on or sealing interference fit with the lip of the outlet port of the APR. In one common configuration, the outlet port of the APR includes a spoke-and-hub structures in which spokes support a donut-shaped hub in the center of the port opening. The hole in the center of the hub is sized to accept the stem of a mushroom-style membrane, which stem presses into the hole in the center of the hub and is there retained, with the membrane in general contact with the spokes of the spoke-and-hub structure and in generally sealed contact with a circumferential rim around the edge of the outlet port. The membrane is shaped and sized to cover the outlet port opening and a portion of this circumferential rim. When a wearer exhales, exhalation pushes the membrane away from the spoke-and-hub structure and from the rim, allowing the exhaled air to escape through the exhalation port. At other times, and particularly when a wearer inhales, the membrane is pulled by negative pressure against the spoke-and-hub structure and the circumferential rim, sealing the outlet port so that air from the outside environment (other than leakage in acceptable volumes, as would be known by one skilled in the art) does not enter the clean air envelope defined by the mask.
APRs may be either positive pressure or negative pressure devices. A positive pressure APR typically includes an external pump or pressurized vessel that forces clean air into the APR through an intake port. Positive pressure creates a more positively sealed clean air envelope, since the pressure within the clean air envelope is higher than the pressure of the external air. Such positive pressure reduces the occurrence of seepage or leakage of air from the outside environment into the clean air envelope of the APR.
A negative pressure APR is more common and less expensive, and uses the negative pressure generated by the wearer's inhalation to assist with sealing the APR to the wearer's face. A wearer's inhalation generates negative pressure inside the clean air envelope as it draws air into the APR through the intake ports. Filter apparatus attached to the intake ports clean air from the outside environment before it passes into the clean air envelope. The negative pressure generated by inhalation assists with maintaining the seal between the APR and the wearer's face and assists with maintaining the seal formed by the outlet port valve.
One disadvantage common to APRs is impairment of the wearer's ability to speak clearly or audibly. Maintenance of a clean air envelope within the APR restricts the volume of air going into or out of the APR. Even exhaled air must pass through a one-way valve before it reaches the outside environment. As a result, the volume of sound generated by a wearer's speech or other vocalizations is notably diminished to listeners, and such vocalizations may be garbled and difficult to understand. This impairment to clear and audible speech is a detriment in many of the APRs typical applications, particularly in military and industrial contexts where clear and audible communication may be imperative.
Several attempts to mitigate this impairment to a wearer's ability to speak and be heard clearly while wearing an APR are known to the art. Some APRs are equipped with a diaphragm element in proximity to the outlet port that acts as a mechanical emitter to more efficiently transmit vibrations created by the wearer's speech from the clean air envelope within the APR to the outside environment without allowing untreated air to pass into the APR. While diaphragms facilitate some improvement in sound transmission, they still result in speech that is largely muted, muffled, and difficult to understand.
Alternate attempts to solve this problem are disclosed by, for example, U.S. Pat. No. 5,463,693. These solutions involve amplifiers, microphones, or both, adapted to fit either on the outlet or inlet port of an APR (externally mounted solutions) or within the clean air envelope (internally mounted solutions). These known solutions generally require substantial modification of the APR, which is a disadvantage if clear vocalization is desired as an optional, but not a mandatory feature, for the APR. The modification to the APR required by these solutions also risks compromise of the integrity of the clean air envelope seal and does not allow a standard APR to be adapted quickly to allow improved vocal transmission. Further, since externally mounted solutions attempt generally to amplify sound transmitted through the APR, they still result in muted and muffled speech. Internally mounted solutions also often require piercing of components of the APR for the passage of wires or other structures, threatening the integrity of the clean air envelope.
It would be a decided advantage to have an enhanced speech transmission device that can be readily attached to an existing APR produced in large quantities, which places a microphone inside of the wearer's clean air envelope, but does not require piercing any portion of the APR, does not require substantial modification of the APR, and enables the wearer to transmit clear speech without substantial muting or muffling.
SUMMARY
Versions of the present invention are directed to an enhanced speech transmission device that can be readily attached to commonly-used APRs. Versions of the present invention are further directed to an enhanced speech transmission APR device. Versions of the present invention are further directed to methods of improving the audibility of the speech of an APR wearer. The present invention satisfies the need for a device that substantially enhances the volume and clarity of the speech of the wearer of an APR and can easily and quickly be attached to or removed from an APR without tools, without substantial modification of the APR, and without piercing any portion of the APR.
BRIEF DESCRIPTION OF THE DRAWINGS
These and other features, aspects, and advantages of the present invention will become better understood with regard to the following description and accompanying drawings, where:
FIG. 1 shows a perspective view of a commonly-used APR suited for modification by an enhanced speech transmission device as described herein;
FIG. 2 shows an exploded view of a commonly-used APR suited for modification by an enhanced speech transmission device as described herein;
FIG. 3 shows a perspective view of one embodiment of an enhanced speech transmission device as described herein;
FIG. 4 shows an exploded view of one embodiment of an enhanced speech transmission device as described herein;
FIG. 5 shows a perspective view of one embodiment of an enhanced speech transmission device as described herein, installed on a APR;
FIG. 6 shows an exploded view of one embodiment of an enhanced speech transmission device as described herein, installed on a APR.
DETAILED DESCRIPTION
Referring now to the specific embodiments shown above, FIGS. 1 and 2 show one commonly-used APR known to the art. In relevant part, this configuration of APR comprises a mask body ( 1 ), one or more APR intake ports ( 3 ), and an outlet port ( 5 ). The mask body ( 1 ) further comprises a gasket ( 7 ) shaped to seal to a wearer's face, and attachment pins ( 9 ). The APR outlet port includes an APR valve portion ( 11 ), in this case a mushroom-style valve membrane coupled to the hub-and-spoke structure within the APR outlet port ( 5 ) of the APR. In the embodiment shown in FIG. 1 , the outlet port ( 3 ) has a generally round protruding lip ( 13 ) to which a cover ( 2 ) can be attached, generally through a press fit. A typical APR further comprises a retaining member ( 15 ) that assists with keeping the APR in sealed connection with the wearer's face. In the APR shown in FIG. 1 , the retaining member ( 15 ) is a strap configured to wrap around the back of the wearer's head on one side, and, on the other side, connects to the APR through one or more attachment points ( 17 ) that attach to the APR attachment pins ( 9 ). It will be understood by one skilled in the art that while one form of commonly used APR is shown, the invention herein is not limited to the depicted APR and can be used with a variety of makes and types of APRs in a variety of configurations, including full masks, positive pressure APRs, APRs in other configurations, and APRs with other outlet port shapes or exhalation valve types.
Referring now to FIGS. 3 and 4 , the enhanced speech transmission device of this invention comprises a main housing ( 19 ), an amplifier assembly ( 21 ), and a microphone ( 23 ). The main housing ( 19 ) comprises a battery housing portion ( 25 ), an amplifier housing portion ( 27 ), and an outlet port portion ( 29 ).
The battery housing portion ( 25 ) comprises positive and negative connectors for an electric power supply. These connectors are operatively connected, such as through insulated wires, to the amplifier assembly ( 21 ). In the preferred embodiment depicted in FIGS. 3 and 4 , the power supply is two AAA size alkaline batteries, the battery housing portion ( 25 ) is shaped to house and secure those batteries, and the positive and negative connectors are metal tabs configured to operatively connect to the positive and negative terminals, respectively, of those batteries. In this preferred embodiment, the positive and negative connectors are operatively connected to at least the amplifier assembly by insulated wires. It will be appreciated by one skilled in the art that different battery sizes, different battery types, different battery configurations, different numbers of battery, and power sources other than alkaline batteries all may be used within the spirit and scope of this invention. It will be further appreciated by one skilled in the art that the device could be powered by a power source remote from the device.
The main housing ( 19 ) further comprises an amplifier housing portion ( 27 ). In the preferred embodiment depicted in FIGS. 3 and 4 , the amplifier housing portion ( 27 ) houses an amplifier assembly that includes at least one amplifier circuit board ( 31 ). The amplifier housing portion ( 27 ), in this preferred embodiment, further houses at least one speaker ( 33 ). Optionally, the amplifier housing portion ( 27 ) may comprise a grill or mesh to more easily allow the transmission of sound from the speaker ( 33 ) to the outside environment. In the preferred embodiment shown in FIGS. 3 and 5 herein, the amplifier housing portion ( 27 ) is located above the outlet port portion ( 29 ). It will be appreciated by one skilled in the art that the amplifier housing portion ( 27 ) may assume a large variety of shapes and sizes other than those depicted in the preferred embodiment discussed herein. It will further be appreciated that the amplifier housing portion ( 27 ) may house an amplifier assembly and one or more speakers ( 33 ), may house only the amplifier assembly with all speakers ( 33 ) located outside of the amplifier housing portion ( 27 ), or may house an amplifier assembly and one or more speakers ( 33 ), with additional speakers ( 33 ) located outside of the amplifier housing portion ( 27 ). It will further be appreciated by one skilled in the art that the amplifier housing portion ( 27 ) is not limited to a specific location on the device, and may be placed in a large number of configurations with respect to the outlet port portion ( 29 ) and the battery housing portion ( 25 ).
The main housing ( 19 ) further comprises an outlet port portion ( 29 ). The outlet port portion ( 29 ) comprises an extension body ( 35 ), a sealing member ( 37 ), a valve portion ( 39 ), and an aperture ( 41 ).
Referring to the preferred embodiment shown in FIGS. 3 and 4 , the outlet port portion ( 29 ) is a structure that generally corresponds to and extends the outlet port ( 5 ) of the APR. In this embodiment, the outlet port portion ( 29 ) is generally round. It will be appreciated by one skilled in the art that virtually any overall shape, size, or configuration of outlet port portion ( 29 ) may be used, so long as it couples to the outlet port ( 5 ) of an APR and includes, either integrally or by coupling, a valve portion ( 39 ) permitting exhalation.
The outlet port portion ( 29 ) further comprises an extension body ( 35 ). The extension body ( 35 ) has a first portion ( 43 ) that is shaped to form a removable sealing connection to the outlet port ( 5 ) of an APR, preferably after the valve ( 11 ) has been removed from the outlet port ( 5 ) of an APR. A sealing member ( 37 ) located on, and preferably circumscribing, the first portion ( 43 ) cooperates with the outlet port ( 5 ) of an APR to seal the connection between the outlet port portion ( 29 ) and the outlet port ( 5 ) of an APR. In the preferred embodiment shown in FIGS. 4 and 6 , the outlet port first portion ( 43 ) has a generally round profile corresponding to the generally round outlet port lip ( 13 ) of the outlet port ( 5 ) of an APR, the sealing member ( 37 ) is a gasket around the outer circumference of the first portion ( 43 ), and the first portion ( 43 ) forms a removable sealing connection to the round outlet port lip ( 13 ) of the outlet port ( 5 ) of an APR when the first portion ( 43 ) is pressed onto the outlet port lip ( 13 ) until the sealing member ( 37 ) engages the inner circumference of the outlet port lip ( 13 ). In a most preferred embodiment, tabs in the outlet portion ( 29 ) cooperate with recesses in the outlet port ( 5 ) of an APR to create an interference fit between the outlet port ( 5 ) of the APR and the device outlet portion ( 29 ) to assist with maintaining a sealed connection between the APR and the amplifier. The first portion ( 43 ) can have a variety of shapes and sizes, and can couple to the outlet port ( 5 ) of an APR in a variety of fashions within the scope and spirit of this invention, as will be appreciated by one skilled in the art, including through a press-on fit, a twist-in fit, a threaded fit, or an interference fit.
The sealing member ( 37 ) ensures that the connection between the first portion ( 43 ) and the outlet port ( 5 ) of an APR is substantially sealed against infiltration of air from the outside environment into the clean air envelope defined by the mask and the device. The sealing member ( 37 ) may comprise one or more gaskets, o-rings, washers, grommets, molded seals, or other sealing structures, as will be appreciated by one skilled in the art. The sealing member ( 37 ) may be made of any material capable of cooperating with another material to form a substantially airtight seal, including plastic, rubber, elastomers, metal, overmolded metal, and other materials that will be apparent to one skilled in the art. In a preferred embodiment, as shown in FIGS. 4 and 6 herein, the sealing member ( 37 ) is a rubber gasket located around the outer circumference of the first portion ( 43 ) of the extension body ( 35 ) that forms a seal between the first portion ( 43 ) and the lip ( 13 ) of the outlet port ( 5 ) of an APR. Although a specific shape and material for the sealing member ( 37 ) are disclosed in the preferred embodiment hereof, it should be understood that the sealing member ( 37 ) may be any structure that cooperates with both the first portion ( 43 ) and the outlet port ( 5 ) of an APR to form a detachable sealed connection. Accordingly, a variety of seal types, structures, shapes, sizes, and materials may be used for the sealing member ( 37 ) within the scope and spirit of this invention. Further, the sealing member ( 37 ) may be integral to one or more of the first portion ( 43 ) or outlet port ( 5 ) of an APR.
The extension body ( 35 ) further comprises a second portion ( 45 ) that may include a valve portion ( 39 ). The second portion ( 45 ) may comprise an integral valve portion, or it may be shaped to connect to a removable valve portion, including specifically a valve portion ( 39 ) that comprises a valve ( 11 ) removed from an APR. In the preferred embodiment shown in FIGS. 3, 4, and 6 , the second portion ( 45 ) comprises a spoke-and-hub structure that corresponds to the spoke-and-hub structure in the outlet port ( 5 ) of an APR with which the device is, in that embodiment, intended to be used. The second portion includes a central hub ( 47 ). A hole in the hub ( 47 ) is sized to receive and retain the stem ( 49 ) of a valve ( 11 ) removed from the APR, and the second portion ( 45 ) is sized and shaped to be sealed substantially in one direction by a valve ( 11 ) removed from the APR in generally the same fashion as the outlet port ( 5 ) of an APR was sealed by that same valve ( 11 ). It will, however, be appreciated by one skilled in the art that other sizes, shapes, and configurations may be used for the second portion ( 45 ) within the scope and spirit of this invention, so long as the second portion ( 45 ) includes (whether integrally or by coupling) a valve portion ( 39 ) that substantially permits air exhaled by the wearer to escape the clean air envelope and prohibits significant volumes of air from the outside environment from entering the clean air envelope defined by the APR and the device.
The valve portion ( 39 ) is a one-way valve structure that allows air exhaled by the wearer to escape from the clean air envelope without allowing significant volumes of air from the outside environment to enter the clean air envelope defined by the APR and the device, particularly when the wearer inhales. The valve portion ( 39 ) may be of virtually any size or shape, so long as it cooperates with the second portion ( 45 ) to substantially permit air exhaled by the wearer to escape from the clean air envelope and prohibit any significant volumes of air from the outside environment from entering the clean air envelope defined by the APR and the device. Preferably, the second portion ( 45 ) and valve portion ( 39 ) will cooperate to prohibit air from the outside environment from entering the clean air envelope at any rate exceeding 30 milliliters per minute at a suction pressure of 25 mmH 2 O. Most preferably, the second portion ( 45 ) comprises a structure corresponding to the valve retention structure of the outlet port ( 5 ) of the APR with which the device is intended to be used, and the valve portion ( 39 ) comprises a valve ( 11 ) removed from that APR.
The valve portion ( 39 ) may comprise one or more valves or valve assemblies shaped to couple to said second portion ( 45 ) or one or more valve membranes shaped to couple to said second portion ( 45 ). A membrane comprising a valve portion, in whole or in part, may be made of a variety of air-impermeable materials, including natural rubber, silicone rubber, or neoprene. The valve portion ( 39 ) may comprise virtually any style of exhalation valve used on a commercially available APR, including mushroom-style valves and their membranes sheet-style valves and their membranes. In the preferred embodiment shown in FIGS. 3 and 4 , the valve portion ( 39 ) is a mushroom-style valve membrane ( 11 ) removed from the outlet port ( 5 ) of an APR and reinserted by its stem ( 49 ) into a hub ( 47 ) located on the second portion ( 45 ).
The extension body ( 35 ) further comprises an aperture ( 41 ). The aperture ( 41 ) is a void passing through a portion of the wall of the extension body ( 35 ) between the sealing member ( 37 ) and the valve portion ( 39 ), such that the aperture is located within the clean air envelope but does not substantially interfere with the sealed removable connection between the extension body first portion ( 43 ) and the outlet port ( 5 ) of an APR. The aperture ( 41 ) can be of any size or shape, but is preferably sized to accommodate electrical connections, preferably insulated wires, running from a microphone ( 23 ) to the amplifier assembly ( 21 ). In the preferred embodiment, shown in FIGS. 3 and 4 , the aperture ( 41 ) is located at the top of the extension body ( 35 ). Preferably, the aperture ( 41 ) is sealed around the electrical connections to prohibit excessive leakage of air from the outside environment to within the clean air envelope.
The device further comprises an amplifier assembly. The amplifier assembly comprises one or more amplifier circuit boards ( 31 ). As will be appreciated by one skilled in the art, the amplifier circuit board ( 31 ) includes capacitors, resistors and other electrical components which cooperate to filter and amplify the signal received from the microphone ( 23 ). The one or more amplifier circuit boards ( 31 ) provide an amplified signal to one or more speakers ( 33 ), as will be appreciated by one skilled in the art. The amplifier circuit board ( 31 ) is operatively connected to a power source through the battery housing portion ( 25 ), and is further operatively connected to the microphone ( 23 ). In the preferred embodiment shown in FIGS. 3 and 4 , one amplifier circuit board ( 31 ) and one speaker ( 33 ) are contained within the amplifier housing portion ( 27 ). In this preferred embodiment, the amplifier circuit board ( 31 ) is operatively connected to two AAA-sized alkaline batteries located in the battery housing portion ( 25 ) by insulated wires, is further operatively connected to one speaker ( 33 ) located within the amplifier housing portion ( 27 ) by insulated wires, and is operatively connected to a microphone ( 23 ) located within the outlet port portion ( 29 ) by insulated wires running through the aperture ( 41 ), so that sound signals picked up by the microphone ( 23 ) are carried to the amplifier circuit board ( 31 ), are there filtered and amplified, and are projected in filtered and amplified form by a speaker ( 33 ) through a vent or grill in the amplifier housing portion ( 27 ). It will be understood by one skilled in the art that a large variety of amplifier circuit board types and speaker types may be used within the scope and spirit of this invention. It will further be understood that while the speaker is preferably located within the amplifier housing portion, one or more speakers may within the scope and spirit of this invention be located outside of the amplifier housing portion. Further, multiple amplifier circuit boards, or multiple speakers, or both, may be used within the scope and spirit of this invention.
The device further comprises a microphone ( 23 ) located within the outlet port portion ( 29 ). Virtually any size, shape, and style of microphone may be used, provided the microphone ( 23 ) fits within the outlet port portion ( 29 ) and can be powered by one or more of the amplifier assembly or directly by a power source connected to the battery housing portion ( 25 ). The microphone ( 23 ) is operatively connected to the amplifier assembly, preferably by insulated wires running through the aperture ( 41 ). The microphone ( 23 ) may be powered by the amplifier assembly ( 21 ) or may optionally be directly operatively connected to a power source through the battery housing portion ( 25 ). In the preferred embodiment shown in FIGS. 3 and 4 , the microphone ( 23 ) is a button-type microphone seated in and secured by a fitted socket located on the interior face of the second portion ( 45 ) of the extension body ( 35 ). As will be appreciated by one skilled in the art, the microphone ( 23 ) may be located in virtually any location within the clean air envelope defined by the outlet port portion ( 29 ) and may be secured to the outlet port portion ( 29 ) by a variety of mechanical or chemical connection means, such as sockets, screws, brackets, staples, ledges, interference fits, or glues.
Optionally, as shown in the preferred embodiment in FIGS. 5 and 6 , the main housing ( 19 ) may further comprise APR attachment points ( 17 ) configured to attach to APR attachment pins ( 9 ). In this preferred embodiment, an attachment point ( 17 ) is disposed on either side of the amplifier housing portion ( 27 ). When said attachment points ( 17 ) are coupled to the attachment pins ( 9 ) of an APR, they assist with holding the device in place on the APR, and specifically assist with maintaining a sealed connection between said outlet port portion ( 29 ) and the outlet port ( 5 ) of an APR. Further optionally, the main housing ( 19 ) may additionally comprise substitute attachment pins ( 53 ) for connection to a retaining member ( 15 ). In the preferred embodiment shown in FIGS. 5 and 6 , the substitute attachment pins ( 53 ) are coupled to the APR attachment points of a retaining member ( 15 ). The retaining member ( 15 ) optionally provides additional assistance and support in holding the APR in place on the wearer's face and in maintaining a sealed connection between said first portion ( 43 ) of said extension body ( 35 ) and the outlet port ( 5 ) of an APR.
As will be appreciated by one skilled in the art, embodiments of the present device may be configured to be certified for intrinsic safety. Other embodiments of the present device may be configured to not be certified for intrinsic safety.
Although the present invention has been described in considerable detail with reference to certain preferred versions thereof, other versions are possible. For example, other mask types, outlet port shapes, sealing member configurations, valve types, housing configurations, microphone types, speaker types, power sources, or amplification means than those disclosed herein may be used within the spirit and scope of this invention. | An electrical amplifier unit which removably attaches to a gas mask and includes a microphone for detecting voice sounds emitted by the wearer of the gas mask, circuitry for amplifying the detecting sound, and a loudspeaker for emitting the amplified sounds externally of the mask. The associated components are contained within a housing that attaches sealably to the outlet port of a gas mask. The amplifier unit is quickly and easily attachable to commercially available gas masks without additional hardware and does not affect the structural and functional integrity of the host mask. | 0 |
TECHNICAL FIELD
[0001] The present invention relates generally to combine harvesters but, more particularly, to improved sieve operation and grain cleaning.
BACKGROUND ART
[0002] Cleaning systems, for combine harvesters, will cleanse threshed grain by blowing air through a set of planar sieves, utilizing gravitational forces to urge cleaned grain through the sieve openings. However, with higher capacity harvesting machines, the capacity for threshing the grain has increased beyond the throughput capacity of the attendant cleaning systems and the sieve operations. Accordingly, it is desirable to increase both the capacity and the efficiency of the cleaning systems, in combine harvesters, so that such systems contribute to an increase in the combine's overall rate of harvesting.
[0003] In the past, this problem has been addressed in rotary cleaning systems by incorporating drive mechanisms compactly situated in a combine base unit where each of the individually driven components of the rotary cleaning device are rotatable about a common axis of rotation, i.e. a cleaning cylinder, an infeed mechanism, a fan, and an impeller are rotatable about said common axis of rotation and a composite drive shaft. The rotary system is discussed in, for example, U.S. Pat. No. 4,422,462 by Frans Decoene.
[0004] However, for non-rotary tailings conveyors in combine harvesters, such as disclosed in U.S. Pat. No. 7,028,457 by Schmidt, which enable more efficient conveying of tailings by utilizing threshing plate units installable in a housing with vertically stacked drive shafts, each having a separate axis of rotation, there is a need for improved cleaning efficiencies with far more limited space restrictions.
[0005] For example, a crop such as grain which is threshed into the clearances between the combine rotor and its housing, falls through perforations in the housing and is transported to a cleaning system which includes a chaffer sieve stacked atop a shoe sieve. The chaffer sieve and shoe sieve, as two members of the cleaning system, oscillate back and forth. Each sieve has a plurality of apertures for allowing the properly threshed grain to fall therethrough but not the chaff. A blower blows air up though the sieves and out the rear of the combine. The separated chaff will be blown outward along with the air, while the clean grain falls, theoretically, through the sieves onto an inclined plane. Clean grain then travels along the inclined plane and then through a grain elevator to a grain storage area. However, in order to save space, rail and seal attachments to the sieves are contoured in shape to accommodate, during oscillation, certain bearings and lock bars on drive shafts for the tailings conveyor or impeller that extends through the combine side sheets or walls. This contour permits an appreciable amount of clean crop such as grain, corn or beans to fall between the sieves and the side wall, failing therefore to fall onto the inclined plane, and thus never being carried to the grain elevator or storage bin. The combine side wall through which the drive shaft extends, serves as a common wall between the tailings conveyor unit and the combine itself. The wall structurally supports drive shafts, and impellers, from the tailings conveyor unit. Accordingly, there are bearings and lock collars required on the drive shaft which must be avoided by the chaffer sieve by way of a cut-out or a break in the rail and seal, or alternatively the rail and seal can be bent. This contour allows the chaffer sieve's oscillation to occur without rubbing against the bearing and lock collar, and without distorting the rotation of the drive shafts.
[0006] A combine design that would enable more perfect seal of the sieves against the combine side wall and inhibit loss of crop, without weakening the impeller drive shafts or distorting shaft rotation would not only reduce crop loss, but save space, and reduce wear and tear on the bearing and lock collar. This would, in turn, satisfy a longfelt need in the industry, provide unexpected efficiencies, and advance the art of combine harvesters.
SUMMARY OF THE INVENTION
[0007] What is disclosed is an improved tailings conveyor bearing assembly, including an improved drive shaft which overcomes one or more of the limitations and shortcomings set forth above.
[0008] It is a feature of this invention that the need for lock bars or lock collars for bearing assemblies on the end of the tailings impeller drive shafts located closest to the sieves, is negated.
[0009] It is another feature of this invention that the rails and seal will oscillate flush against the drive shafts and bearings without the need for bending or breaking the rail and seal, and will allow greater crop throughput during cleaning.
[0010] It is also a feature of this invention that the rotation of the drive shaft and impeller is protected from distortion during contact with the oscillating chaffer sieve's rail and seal.
[0011] These and other objects, features and advantages are accomplished according to the instant invention by providing a drive mechanism and assembly for the tailings conveyor cleaning function of a combine harvester. The invention comprises a shaft, having on one end, a self-locking flush mounted bearing, and at its opposite end, a non-locking bearing and a lock collar for mounting between a structural element such as a pulley or sheave and a wall. The first end portion of the drive shaft is configured to be received in a self-locking first bearing such that the shaft extends in a predetermined direction. The second end of the shaft is mounted through a second bearing in an opposite direction but having the same rotational axis as the first bearing, such that the drive shaft is receivable in a second bearing's receptacle but held in place by a spaced apart locking element, as, for example, a locking bar or lock collar.
[0012] The invention enables mounting the combine tailing impeller drive shaft adjacent to the body of the combine efficiently, i.e. without loss of crop, or weakening of support, or distorting shaft rotation. The functional areas will all have improved output performances and the drive system will have improved reliability.
BRIEF DESCRIPTION OF THE DRAWINGS
[0013] FIG. 1 is a simplified side view of a combine harvester embodying the relative positioning of the sieves, impellers and drive shafts which function more effectively as a consequence of my invention;
[0014] FIG. 2 is a close-up cutaway top view of a prior art combine harvester's bearing assembly and a bent rail seal from the chaffer sieve, which bending is necessitated by the construction of the bearing assembly;
[0015] FIG. 3 is a side view of a prior art combine harvester's bearing assembly of FIG. 2 but also illustrating the drive shaft impeller, and top pulley or sheave;
[0016] FIG. 4 is a side view of the combine harvester bearing assembly of my invention, further embodying an unbent rail and seal construction;
[0017] FIG. 5 is a top view of the combine harvester bearing assembly and the unbent rail and seal of my invention as illustrated in FIG. 4 ;
[0018] FIG. 6 is a cutaway along line 6 - 6 of FIG. 5 , illustrating a side view of the combine harvester bearing assembly of my invention, and also illustrating additional components of this invention;
[0019] FIG. 7 is a further side view of the harvesting machine of my invention as illustrated in FIG. 1 , depicting an embodiment of a tailings conveyor within the machine, with a cover or wall for the conveyor removed to show internal aspects such as the impeller design details;
[0020] FIG. 8 is a perspective view of an embodiment of the conveyor of FIG. 7 in association with a feed auger of the machine for feeding tailings to the conveyor;
[0021] FIG. 9 is a simplified perspective view of the tailings conveyor of FIG. 7 , showing embodiments of threshing plates of the invention;
[0022] FIG. 10 is a simplified perspective view of the tailings conveyor taken along line 10 - 10 of FIG. 9 ; and
[0023] FIG. 11 is a frontal view of the tailings conveyor housing of FIG. 7 with a cover or wall removed and illustrating tailings being conveyed through the conveyor in a turbulent manner as a result of contact with the threshing plates.
DETAILED DESCRIPTION OF THE INVENTION
[0024] Referring to FIG. 1 , an agricultural harvesting machine 10 , incorporating the principles of the instant invention, has a header 12 , and a feeder 16 . Crop material is collected by header 12 and taken into agricultural harvesting machine 10 through feeder 16 in a conventional manner.
[0025] A threshing assembly 18 includes a rotor 20 and a perforated housing 22 . Rotor 20 is rotated within perforated housing 22 . Crop is received from feeder 16 and is passed through clearances between rotor 20 and perforated housing 22 to thresh the crop, e.g. grain. Grain which is threshed in the clearances between housing 22 and rotor 20 falls through the perforations in housing 22 and is transported to a cleaning system 24 including a chaffer sieve 26 and a shoe sieve 28 . Chaffer sieve 26 and shoe sieve 28 are members that oscillate back and forth against wall 100 which is a common wall between the tailings housing 40 and the cleaning system. Sieves 26 and 28 have a plurality of apertures for allowing the properly threshed grain to fall through. A blower 30 blows air through sieves 26 and 28 and out the rear of agricultural harvesting machine 10 . Chaff will be blown outward along with the air. The clean grain falls through sieves 26 and 28 onto an inclined plane 32 . Clean grain travels along plane 32 and then through a grain elevator 34 , to a grain storage area 36 .
[0026] Grain and material other than grain (MOG), which is too heavy to become air borne and falls through chaffer sieve 26 but does not pass through shoe sieve 28 is commonly known as tailings. Tailings end up on a plane 38 and are rethreshed and conveyed in a tailings conveyor 40 and discharged from tailings conveyor 40 onto chaffer sieve 26 .
[0027] As is best seen in FIGS. 7 through 11 , tailings conveyor 40 includes a housing 42 including its wall 100 and an interior portion 43 ; a first opening 44 ( FIG. 9 ) communicating with interior portion 43 ; a first rotary impeller 46 and a second rotary impeller 48 located in interior portion 43 ; and a second opening 50 communicating with interior 43 and a conduit 52 . The first and second impellers 46 and 48 are each rotated in predetermined rotational directions A on shafts 58 and 51 , respectively, about substantially parallel rotational axes C and D extending longitudinally through the centers of shafts 58 and 51 , respectively.
[0028] Housing 42 receives the tailings through first opening 44 of wall 100 by means of a conventionally constructed and operable auger 54 , as depicted in FIG. 3 . Auger 54 , as shown in FIGS. 8 , 9 and 10 , rotates about rotational axis C on a shaft 56 coaxial with shaft 58 for moving the tailings toward tailings conveyor 40 , such that the tailings will be discharged by auger 54 through first opening 44 into interior portion 43 of housing 42 in a position to be propelled by rotating first impeller 46 through interior portion 43 to second impeller 48 . As an alternative, first opening 44 can be offset from the shaft 58 , such as depicted at 44 a in FIG. 9 , so that, for instance, tailings 60 are delivered into housing 42 at a lower location or more in the vicinity of the radial outer portion of first impeller 46 .
[0029] First impeller 46 , and second impeller 48 , each include a plurality of blades 47 extending generally radially outwardly relative to the rotational axis of the respective impeller. Each of the blades 47 is preferably curved or arcuate so as to have a concave surface 47 a facing oppositely of the rotational direction A, and a convex surface 47 b facing forwardly in or toward the rotational direction A, such that each blade 47 is swept back relative to the rotational direction A, as best shown in FIG. 11 .
[0030] The impellers 46 , 48 and the second opening 50 are preferably radially in-line or aligned, such that tailings 60 which enter housing 42 at opening 44 , or 44 a , are propelled in rotational direction A by first impeller 46 along a radially inwardly facing threshing surface 64 a of a first threshing plate 64 , and into the path of rotation of radially adjacent second impeller 48 , as denoted by large arrow B. Second impeller 48 will then propel tailings 60 in direction A along a radially inwardly facing threshing surface 68 a of a second threshing plate 68 , and through second opening 50 into conduit 52 . Tailings 60 exit through a discharge outlet 62 , so as to be spread over a predetermined region of chaffer sieve 26 , or another location if desired. In interior portion 43 of housing 42 , a radially inwardly facing common housing wall 66 guides and enhances the radial direction of travel of tailings 60 from first impeller 46 to second impeller 48 .
[0031] The preferred rotational direction A for both of impellers 46 and 48 is clockwise. The curved or arcuate or swept back shape of the blades 47 on impellers 46 and 48 has been found to cause a more aggressive threshing of tailings 60 and forces the tailings 60 to the radially outer portion of the blades 47 faster, which has been found to increase conveying capacity. Threshing plate surfaces 64 a and 68 a may each have a rough surface texture or smooth, and/or can include elements such as raised protuberances and the like, for imparting a desired turbulence to the tailings flow, for performing a desired threshing function, as discussed in more detail below.
[0032] Impellers 46 and 48 each include a mounting portion 82 which is preferably a hub, mountable to a rotatable member, such as shaft 58 of conveyor 40 in the instance of impeller 46 , for rotation with the rotatable member in a predetermined rotational direction, such as direction A, about a rotational axis, such as axis C, as best shown in FIG. 11 . Each impeller 46 and 48 includes a plurality of blades 47 , preferably four in number, which extend generally radially outwardly from mounting portion 82 at equally spaced locations around the rotational axis. As noted before, each blade 47 includes a surface 47 a facing in a direction opposite the rotational direction, and a surface 47 b facing in the rotational direction.
[0033] Referring back now to prior art FIGS. 2 and 3 , the prior art cleaning systems required a conventional bearing 102 and locking collar 110 on the end of shaft 51 on the opposite side of wall 100 from the impeller 48 . This construction necessitated bending of wiper seal 101 a which was connected to chaffer sieve 26 , which bending weakens the integrity of the seal and allows grain unseparated from the chaff to fall through the resulting opening between seal 101 a and wall 100 .
[0034] Referring to FIGS. 4 , 5 and 6 , the bearing assembly 102 of the present invention contains a polygonal or, preferably hexagonal interior profile within the bearing surface 109 which receives a congruently profiled stub shaft end 51 a of shaft 51 , which stub shaft end 51 a is therefore configured in a polygonal fashion for secure engagement with the inner surface 109 of bearing 102 . The walls 104 of bearing 102 define the inner race for the bearing. Walls 103 of bearing 102 define the inner race of bearing 102 . Shoulder 51 b of shaft 51 rests firmly against bearing 102 and walls 104 . Connectors, such as carriage bolts 107 and nut 108 , can secure, for example, a mounting flange 106 for mounting bearing 102 to the wall 100 , or side sheet or alternatively 100 can be a cover. The bearing assembly of the present invention enables a stronger wiper seal construction 101 as depicted in FIG. 5 which has greater integrity and can be flush mounted against wall 100 , thus preventing loss of grain or other crop and providing for a more efficient cleaning system.
[0035] Conventional bearing 121 is mounted around shaft 51 and locking collar 120 is spaced apart relationship between wall 200 and sheave or pulley 201 .
[0036] It will be understood that changes in the details, materials, steps, and arrangements of parts which have been described and illustrated to explain the nature of the invention will occur to and may be made by those skilled in the art upon a reading of this disclosure within the principles and scope of the invention. The foregoing description illustrates the preferred embodiment of the invention; however, concepts, as based upon the description, may be employed in other embodiments without departing from the scope of the invention. Accordingly, the following claims are intended to protect the invention broadly as well as in the specific form shown. | An improved bearing assembly for mounting a drive shaft and bearings, having an upper impeller drive shaft for the tailings conveyor of a combine harvester occupy the same space as the cleaning system rail and seal of a chaffer sieve, is disclosed. The assembly has a flush mounted bearing at one end of the shaft and a normal bearing and lock collar at the shaft's opposite end. | 0 |
FIELD OF THE INVENTION
[0001] The present invention relates to a combination formulation for oral administration comprising a sustained release formulation of a 3-hydroxy-3-methylglutaryl coenzyme A (HMG-CoA) reductase inhibitor and a rapid release film layer of an anti-hypertensive agent; and a method for preparing the same.
BACKGROUND OF THE INVENTION
[0002] Hypercholesterolemia, a representative example of hyperlipidemia, is caused by elevated serum LDL (low-density lipoprotein)-cholesterol and total cholesterol levels, and the treatment of hypercholestrolemia by reducing the level of lipid, especially LDL-cholesterol, in serum, makes it possible to lower the risk of cardiovascular disorders, which leads to delayed progression of arteriosclerosis ( American diabetes association , Diabetic care, 23 (suppl.), S57-S65, 2000). Therefore, there have been many studies on lipid-lowering therapy for delaying the progression of arteriosclerosis or alleviating arteriosclerosis so as to reduce the risk of cardiovascular disorders, e.g., coronary heart disease, in a patient diagnosed as hyperlipidemia or hypercholestrolemia.
[0003] 3-Hydroxy-3-methylglutaryl coenzyme A (HMG-CoA) reductase inhibitor used for hyperlipidemia such as hypercholesterolemia has been known to inhibit the conversion of HMG-CoA into mevalonate in the early stage of the cholesterol biosynthetic pathway, which results in lowering the total cholesterol and LDL-cholesterol levels, or elevating the high-density lipoprotein (HDL)-cholesterol level (S. M. Grundy, N. Engl. J. Med., 319(1), 24-32, 1988). However, such an HMG-CoA reductase inhibitor causes side effects such as liver toxicity, myopathy and rhabdomyolysis (Garnett W. R., Am. J. Cardiol., 78, 20-25, 1996; Dujovne C. A. et. al., Am. J. Med., 91, 25S-30S, 1991; and Mantell G. et. al., Am. J. Cardiol, 66, 11B-15B, 1990).
[0004] Accordingly, there have been numerous attempts to develop a sustained release formulation of an HMG-CoA reductase inhibitor in order to prevent or alleviate the side effects induced by the rapid release of HMG-CoA reductase inhibitor.
[0005] Many studies have suggested that a sustained release formulation of an HMG-CoA reductase inhibitor gives a lower bioavailability of the HMG-CoA reductase inhibitor for systemic circulation as compared with a rapid release formulation because most of the HMG-CoA reductase inhibitor absorbed into the body is metabolized in the liver (85% and more) while only 5% or less account for that transferred to the systemic circulation system. However, the drug delivering efficiency of a sustained release formulation to a target site is shown to be superior to that of a rapid release formulation (John R, Amer. J. Cardio. 89: 15, 2002). Accordingly, a sustained release formulation of an HMG-CoA reductase inhibitor has been reported to be more effective in lowering the LDL-cholesterol level in blood than a rapid release formulation (Monique P, Am. J. Drug Deliv. 1(4): 287-290, 2003).
[0006] Hypertension is accompanied by hyperlipidemia in many cases, which may cause cardiac disorders such as angina pectoris, and thus, it is very important to control hypertension together with administering an inhibitor of cholesterol-synthesis no matter whether or not the patent is suffering from coronary heart diseases, in order to reduce the risk or fatality arising from cardiovascular disorders.
[0007] For example, Kramsch et. al. have disclosed that a calcium channel blocking agent such as amlodipine, an antihypertension agent, can be administered together with a lipid-lowering agent to enhance the therapeutic effects against atherosclerosis (Kramsch et. al, Journal of Human Hypertension , Suppl. 1, 53-59, 1995), and Lichtlen P. R. et. al. have reported that early atherosclerotic disease in human can be effectively treated by administering with a calcium channel blocking agent (Lichtlen P. R. et. al., Lancet, 335, 1109-1139, 1990; and Waters D. et. al., Circulation, 82, 1940-1953, 1990).
[0008] Further, U.S. Pat. No. 4,681,893 disclosed that some statin drugs including atrovastatin are useful for treating atherosclerosis, and it has been reported that in case of administering a statin drug (pravastatin or lovastatin) together with a calcium channel blocking agent (amlodipine), atherosclerotic diseases can be better treated through the synergistic effects of the two drugs (Jukema et. al., Circulation, Suppl. 1, 1-197, 1995; and Orekhov et. al., Cardiovescular Drug and Therapy, 11, 350, 1997). However, Caduet® (Pfizer), a commercially available atrovastatin-amlodipine combination formulation, has the problem that both drugs are rapidly released causing liver toxicity, while therapeutic effects thereof cannot be maintained over a long period.
[0009] The present inventors have therefore endeavored to develop a combination formulation for oral administration of HMG-CoA reductase inhibitor and antihypertensive agent that is free from the above problems, and have found that a combination formulation for oral administration comprising a sustained release formulation of an HMG-CoA reductase inhibitor coated with a rapid release film layer of an anti-hypertensive agent exhibits unexpected synergistic effects of two drugs with minimal side effects.
SUMMARY OF THE INVENTION
[0010] Accordingly, it is an object of the present invention to provide a combination formulation of an HMG-CoA reductase inhibitor and an anti-hypertensive agent, which exhibits synergic effects of two drugs with minimal side effects.
[0011] It is another object of the present invention to provide a method for preparing said formulation.
[0012] In accordance with one aspect of the present invention, there is provided a combination formulation comprising a sustained release formulation of an HMG-CoA reductase inhibitor and a rapid release film layer containing an anti-hypertensive agent, the rapid release film layer being coated on the sustained release formulation.
[0013] In accordance with another aspect of the present invention, there is provided a method for preparing the combination formulation, which comprises the steps of:
[0014] 1) drying a mixture of a HMG-CoA reductase inhibitor, a solubilizing carrier and a stabilizing agent to obtain a solid dispersion;
[0015] 2) dry-blending the solid dispersion obtained in step 1 with a carrier for sustained release and a gel hydration accelerator, and formulating the dry-blended mixture to obtain a sustained release formulation; and
[0016] 3) coating the sustained release formulation obtained in step 2 with a rapid release film layer comprising the antihypertensive agent to obtain the combination formulation.
BRIEF DESCRIPTION OF THE DRAWINGS
[0017] The above and other objects and features of the present invention will become apparent from the following description of the invention, when taken in conjunction with the accompanying drawings which respectively show:
[0018] FIG. 1 : a cross-sectional diagram of a representative example of the inventive combination formulation;
[0019] FIG. 2 : the solubilities of the solid dispersions prepared in Examples 1 to 3 and Comparative Example 1;
[0020] FIG. 3 : the drug dissolution rates of the sustained release formulations prepared in Examples 4 to 6;
[0021] FIG. 4 : the drug dissolution rates of the sustained release formulations prepared in Examples 7 and 8;
[0022] FIG. 5 : the simvastatin dissolution rates of the combination formulations prepared in Examples 9 to 11;
[0023] FIG. 6 : the simvastatin dissolution rate of the combination formulation prepared in Example 9 at a spin velocity of 50, 100 or 150 rpm; and
[0024] FIG. 7 : the amlodipine dissolution rates of the combination formulations prepared in Examples 9 to 11, and Norvasc® (Pfizer).
DETAILED DESCRIPTION OF THE INVENTION
[0025] Hereinafter, the components of the combination formulation of the present invention are described in detail as follows:
[0000] 1. Sustained Release Formulation
[0026] The sustained release formulation corresponding to the nucleus of the inventive combination formulation comprises a solid dispersion comprising an HMG-CoA reductase inhibitor as an active ingredient, solubilizing carrier and stabilizing agent; a carrier for sustained release; and a gel hydration accelerator.
[0027] 1) Pharmacologically Active Ingredient
[0028] The HMG-CoA reductase inhibitor may be one of the known HMG-CoA reductase inhibitors used for treating hyperlipidemia and arteriosclerosis by lowering the lipoprotein or lipid level in blood. Representative examples thereof include mevastatin (U.S. Pat. No. 3,983,140), lovastatin (U.S. Pat. No. 4,231,938), pravastatin (U.S. Pat. Nos. 4,346,227 and 4,410,629), lactone of pravastatin (U.S. Pat. No. 4,448,979), velostatin, simvastatin (U.S. Pat. Nos. 4,448,784 and 4,450,171), rivastatin, fluvastatin, atrovastatin, cerivastatin and the like. The HMG-CoA reductase inhibitor may be employed in an amount ranging from 1 to 50% by weight, preferably from 2 to 30% by weight based on the total weight of the combination formulation. When the amount is less than 1% by weight, its therapeutic effect cannot be expected, and when more than 50% by weight, it exceeds the allowable daily dose.
[0029] 2) Solubilizing Carrier
[0030] Since most HMG-CoA reductase inhibitors are poorly water-soluble compounds, a solubilizing carrier is used for enhancing the drug's solubility in the present invention. Representative examples of the solubilizing carrier include vitamin E TPGS (d-α-tocopheryl polyethylene glycol 1000 succinate: Eastman), polyoxyethylene stearic acid ester (e.g., Myrj: ICI), polyethylene glycol, hydroxypropylmethylcellulose (HPMC, viscosity: 3 to 15 cps), polyoxypropylene-polyoxypropylene block copolymer and the like. The solubilizing carrier may used in an amount ranging from 0.05 to 20 parts by weight, preferably 0.1 to 10 parts by weight based on 1 part by weight of the HMG-CoA reductase inhibitor. When the amount is less than 0.05 parts by weight, it is difficult to achieve the drug solubilization, and when more than 10 parts by weight, the sustained release of the drug cannot be expected.
[0031] 3) Stabilizing Agent
[0032] The stabilizing agent used in the present invention may be any one of the known stabilizing agents which prevent the drug oxidation during the process of preparing the solid dispersion comprising the solubilizing carrier or forming the film layer comprising the antihypertension agent. Exemplary stabilizing agents include butylated hydroxy toluene (BHT), butylated hydroxy anisol (BHA), erythorbic acid, ascorbic acid, tocopherol and the like. The sustained release formulation of the present invention may comprise the stabilizing agent in an amount ranging from 0.001 to 3 parts by weight, preferably 0.002 to 2 parts by weight based on 1 part by weight of the HMG-CoA reductase inhibitor. When the amount is less than 0.002 parts by weight, it is difficult to attain the expected drug stability, and when more than 3 parts by weight, the stability of the stabilizing agent itself becomes poor. Further, the film layer comprising the antihypertension agent may comprise the stabilizing agent in an amount ranging from 0.004 to 6 parts by weight, preferably 0.008 to 4 parts by weight based on 1 part by weight of the antihypertension agent. When the amount is less than 0.004 parts by weight, the desired drug stability cannot be achieved, and when more than 6 parts by weight, it is difficult to form the film layer.
[0033] 4) Carrier for Sustained Release
[0034] In the present invention, a carrier for sustained release is used for forming a hydrogel and it is preferably a mixture of xanthan gum and locust bean gum. Generally, xanthan gum contributes to the structural integrity maintenance of the formulation, thereby minimizing the change in the dissolution rate by physical forces such as gastrointestinal motility, and locust bean gum enhances the structural integrity in combination with xanthan gum. If the carrier is a mixture of components having specific component ratio, the initial burst release and the change in dissolution rate caused by physical forces can be reduced.
[0035] The carrier for sustained release may be employed in an amount ranging from 0.5 to 20 parts by weight, preferably 1 to 10 parts by weight based on 1 part by weight of the HMG-CoA reductase inhibitor. When the amount is less than 0.5 parts by weight, the sustained release of the drug becomes unsatisfactory, and when more than 20 parts by weight, the drug may be released too slowly. Further, in case of using a mixture of xanthan gum and locust bean gum as the carrier for sustained release, locust gum may be used in an amount ranging from 0.01 to 5 parts by weight, preferably 0.05 to 2 parts by weight based on 1 part by weight of the xanthan gum.
[0036] 5) Gel Hydration Accelerator
[0037] When the sustained release formulation of the present invention is brought into contact with in vivo aqueous medium, the gel hydration accelerator allows water to rapidly infiltrate into the internal core of the formulation through rapid hydration leading to the formulation of a single homogeneous gelated core. In the present invention, the gel hydration accelerator may be preferably a mixture of propylene glycol alginate and hydroxypropylmethylcellulose (HPMC). The HPMC used therein preferably has a viscosity ranging from 4,000 to 100,000 cps.
[0038] The gel hydration accelerator may be used in an amount ranging from 0.1 to 20 parts by weight, preferably from 0.5 to 10 parts by weight based on 1 part by weight of the HMG-CoA reductase inhibitor. When the amount is less than 0.1 parts by weight, the gel hydration cannot be expected, and when more than 20 parts by weight, it is difficult to control the release rate of the drug. Further, propylene glycol alginate may be employed in an amount ranging from 0.05 to 20 parts by weight, preferably 0.1 to 10 parts by weight based on 1 part by weight of HPMC.
[0039] 6) Pharmaceutically Acceptable Additive
[0040] The sustained release formulation of the present invention may further comprise at least one of the known pharmaceutically acceptable additives such as a dispersing agent, binder, lubricating agent, sweetening agent, excipient and the like, in order to prepare a solid formulation suitable for oral administration. Representative examples of the pharmaceutically acceptable additive may include polyvinylpyrrolidone (PVP), gelatin, hydroxypropyl cellulose, sucrose fatty acid ester, talc, light anhydrous silicic acid, zinc and magnesium salts of stearic acid and the like.
[0000] 2. Rapid Release Film Layer
[0041] The rapid release film layer of the present invention comprises an antihypertension agent as an active ingredient, which may be selected from the group consisting of calcium channel blocking agents such as amlodipine, isradipine, lacidipine, nicardipine, nifedipine, felodipine, nisoldipine, verapamil, diltiazem and mibefradil; beta blocking agents such as atenolol, metoprolol, bucidolol and carvediol; angiotensin-converting enzyme (ACE) inhibitors such as enalapril, fosinopril, lisinopril, perindopril, benazepril, captopril, trandolapril, losartan, irbesartan, candesartan, valsartan, telmisartan and eprosartan; and potassium-sparing agent such as amiloride and bendroflumethiazide. The antihypertension agent may be employed in an amount ranging from 0.5 to 30% by weight, preferably 1 to 20% by weight based on the weight of the inventive combination formulation. When the amount is less than 0.5% by weight, its therapeutic effect cannot be expected, and when more than 30% by weight, it is difficult to form the film layer.
[0042] The rapid release film layer of the present invention may comprise the stabilizing agent which is used for preparing the sustained release formulation, in order to prevent oxidation of the antihypertension agent. In the rapid release film layer, the stabilizing agent may be used in an amount ranging from 0.04 to 6 parts by weight based on the antihypertension agent.
[0043] Further, the rapid release film layer may comprise at least one of the known film-forming materials such as hydroxypropylmethylcellulose (HPMC), hydroxypropylcellulose (HPC), hydroxyethylcellulose (HEC), celluloseacetatephthalate (CAP), ethylcellulose (EC), methylcellulose (MC), polymethacrylate, Kollicoat® (Basf) and Opadry® (Colorcon). It may further comprise plasticizers such as polyethyleneglycol (PEG), glycerol triacetate (triacetine) and acetylated monoglyceride (Myvacet), and conventional solvents capable of dissolving the film-forming materials such as purified water or ethanol may be used to form the film layer.
[0000] 3. Water-Soluble Film Layer
[0044] The inventive combination formulation may further comprise a water-soluble film layer disposed between the sustained release formulation and the rapid releasing film layer, which blocks the mutual contact of the HMG-CoA reductase inhibitor in the sustained release nucleus with the antihypertension agent in the rapid releasing film layer. The water-soluble film layer may be employed in an amount ranging from 0.5 to 20% by weight, preferably 1 to 10% by weight based on the weight of the inventive combination formulation. When the amount is less than 0.5% by weight, the blocking effect becomes unsatisfactory, and when more than 20% by weight, it adversely affects the drug release.
[0045] Further, the water-soluble film layer may comprise at least one of the known water-soluble film-forming materials such as hydroxypropylmethylcellulose (HPMC), hydroxypropylcellulose (HPC), hydroxyethylcellulose (HEC), celluloseacetatephthalate (CAP), ethylcellulose (EC), methylcellulose (MC), polymethacrylate, Kollicoat® (Basf) and Opadry® (Colorcon). It may further comprise plasticizers such as polyethyleneglycol (PEG), glycerol triacetate (triacetine) and acetylated monoglyceride (Myvacet), and conventional solvents capable of dissolving the film-forming materials such as purified water or ethanol may be used to form the film layer.
[0000] 4. Additional Film Layer
[0046] The inventive combination formulation may further comprise an additional film layer on the outside of the rapid releasing film layer for the protection of the drugs from unfavorable factors such as light and moisture, as well as for the convenience of administration (e.g., masking bitterness). The additional film layer may be a light-shielding film layer, moisture-proof film layer or sugar film layer, which may be employed in an amount ranging from 0.5 to 20% by weight, preferably 1 to 10% by weight based on the weight of the inventive combination formulation. When the amount is less than 0.5% by weight, its protecting effect cannot be achieved, and when more than 20% by weight, it adversely affects the drug release.
[0047] Further, the additional film layer may comprise at least one of the known film-forming materials such as hydroxypropylmethylcellulose (HPMC), hydroxypropylcellulose (HPC), hydroxyethylcellulose (HEC), celluloseacetatephthalate (CAP), ethylcellulose (EC), methylcellulose (MC), polymethacrylate, Kollicoat® (Basf) and Opadry® (Colorcon). It may further comprise plasticizers such as polyethyleneglycol (PEG), glycerol triacetate (triacetine) and acetylated monoglyceride (Myvacet), and conventional solvents capable of dissolving the film-forming materials such as purified water or ethanol may be used to form the film layer.
[0048] The inventive combination formulation for oral administration of a HMG-CoA reductase inhibitor and an antihypertension agent may be prepared by the following steps:
[0049] 1) drying a mixture of a HMG-CoA reductase inhibitor, a solubilizing carrier and a stabilizing agent to obtain a solid dispersion;
[0050] 2) dry-blending the solid dispersion obtained in step 1 with a carrier for sustained release and a gel hydration accelerator, and formulating the dry-blended mixture to obtain a sustained release formulation; and
[0051] 3) coating the sustained release formulation obtained in step 2 with a rapid release film layer comprising the antihypertensive agent to obtain the combination formulation.
[0052] In step 1, the solid dispersion may be prepared by a conventional method such as spray-drying, solvent evaporating, micropulverizing-wetting, melting, and freeze-drying methods, and may preferably have a particle size ranging from 5 to 200 μm in diameter. Further, the pharmaceutically acceptable additive as described above may be added to the solution for facilitating the formulation of the solid dispersion.
[0053] In step 2, the sustained release formulation may be formulated into a tablet by compressing the dry-blended mixture through direct compression, or by compressing, milling and tabletting the dry-blended mixture. Further, the blended mixture may further comprise a pharmaceutically acceptable additive for facilitating the formulation.
[0054] The above method may further comprise the step of coating the sustained release formulation obtained in step 2 with a water-soluble film layer before coating with the rapid release film layer in step 3.
[0055] Further, the above method may further comprise the step of coating the finally obtained combination formulation with an additional film layer for protecting the formulation from degenerative factors such as light and moisture as well as for enhancing the patient compliance (e.g., by blocking a bitter taste).
[0056] The oral combination formulation of the present invention comprising an HMG-CoA reductase inhibitor and an antihypertension agent have advantages in that it maximizes the therapeutic effects of the drugs by the synergism arising from combining the drugs having different release patterns or dosages: the antihypertension agent is rapidly released to enhance its therapeutic effect and the HMG-CoA reductase inhibitor is slowly released at a uniform rate to maintain its blood concentration. Further, the inventive combination formulation may further comprise a separating layer so as to minimize the contact between the two unstable constituent drugs. Accordingly, the inventive formulation can be effectively used for preventing and treating hyperlipidemia, arteriosclerosis, hypertension, cardiovascular disease and the combined disease thereof when orally administered once per day at a single dose.
[0057] The following Examples are intended to further illustrate the present invention without limiting its scope.
EXAMPLES 1 TO 3 AND COMPARATIVE EXAMPLE 1
Preparation of Solid Dispersion
[0058] Simvastatin (Hanmi Fine Chemical Co., Ltd., Korea), MYRJ (ICI, USA), HPMC 2910 (viscosity: 3 to 15 cps, Shin-Etsu, Japan), BHT (UENO Fine Chemical, USA) and light anhydrous silicic acid (as a dispersing agent) were dissolved in a mixture of ethanol and dichloromethane according to the amounts described in Table 1, respectively, and each of the resulting mixtures was subjected to spray-drying to obtain a solid dispersion having an average particle size of 100 μm or below. The solid dispersions of Examples 1 to 3 and Comparative Example 1 obtained thus are shown in Table 1.
TABLE 1 Comparative Component (mg/tablet) Example 1 Example 1 Example 2 Example 3 Acitve Simvastatin 20 20 20 20 ingredient Solubilizing MYRJ x 40 20 20 carrier MPMC 2910 10 10 10 5 Stabilizing BHT x 2 2 2 agent Additive Light anhydrous 5 5 5 5 silicic acid Solvent Ethanol 200 200 200 200 Dichloro Methane 700 700 700 700
EXAMPLES 4 TO 8
Preparation of Sustained Release Formulation for Oral Administration
[0059] The procedure of Example 1 was repeated using Simvastatin, lovastatin or fluvastatin as an active ingredient, together with MYRJ, HPMC 2910, BHT, and light anhydrous silicic acid according to the amounts described in Tables 2 to 4, respectively, to obtain solid dispersions. Then, each of the solid dispersions was mixed with xanthan gum (Kelco, USA), locust bean gum (Cesalpinia, Italy), propylene glycol alginate (ISP, USA), HPMC 2208 (viscosity: 4,000 to 100,000 cps, Shin-Etsu, Japan) and erythorbic acid for about 30 min; and sucrose fatty acid ester and light anhydrous silicic acid powders (finer than mesh 40) were added thereto, and mixed for 5 min. Each of the resulting mixtures was mold into a mass using a shaping assembler, and the mass was crushed down into particles having a mesh size ranging from 20 to 80. The particles were then formulated into a tablet by compressing in a formulator, to obtain a sustained release formulation. The sustained release formulations of Examples 4 to 8 obtained thus are shown in Tables 2 to 4.
TABLE 2 Component (mg/tablet) Example 4 Example 5 Example 6 Active Simvastatin 10 20 40 ingredient Solubilizing MYRJ 20 20 20 agent HPMC 10 10 19 2910 Stabilizing BHT 2 2 2 agent Erythorbic 15 15 15 Acid Gel HPMC 80 80 80 hydration 2208 accelerator Propylene 43 43 43 glycol alginate Carrier for Xanthan gum 80 80 80 sustained Locust bean 10 10 10 release gum Additive Light anhydrous 25 25 25 silicic acid Sucrose fatty 10 10 10 acid ester
[0060]
TABLE 3
Component (mg/tablet)
Example 7
Active
Lovastatin
60
ingredient
Solubilizing
MYRJ
20
carrier
HPMC 2910
10
Stabilizing
BHT
2
agent
Erythorbic acid
15
Gel hydration
HPMC 2208
80
accelerator
Propylene glycol alginate
43
Carrier for
Xanthan gum
80
sustained release
Locust bean gum
10
Additive
Light anhydrous silicic acid
25
Sucrose fatty acid ester
10
[0061]
TABLE 4
Component (mg/tablet)
Example 8
Active
Fluvastatin
60
ingredient
Solubilizing
MYRJ
20
carrier
HPMC 2910
10
Stabilizing
BHT
2
agent
Erythorbic acid
15
Gel
HPMC 2208
80
hydration
Propylene glycol alginate
43
accelerator
Carrier for
Xanthan gum
80
sustained release
Locust bean gum
10
Additive
Light anhydrous silicic acid
25
Sucrose fatty acid ester
10
EXAMPLES 9 TO 11
Preparation of Combination Formulation for Oral Administration
[0062] Each of the sustained release formulations obtained in Examples 5, 7 and 8 was coated with Opadry® AMB (Colorcon) film. Amlodipine camsylate (Hanmi Fine Chemical Co., Ltd., Korea), HPMC 2910 (viscosity: 3 to 15 cps) and acetylated monoglyceride (Myvacet) were dissolved in a mixture of ethanol and dichloromethane according to the amounts described in Table 5, respectively, which was coated on the previous film-coated formulation.
TABLE 5 Component (mg/tablet) Example 9 Example 10 Example 11 Sustained formulation nucleus Example 5 Example 7 Example 8 Active Amlodipine 7.9 7.9 7.9 Ingredient camsylate Coating HPMC 2910 10 10 10 Agent Plasticizer Myvacet 1.6 1.6 1.6 Stabilizing BHT 0.1 0.1 0.1 Agent Solvent Ethanol 120 120 120 Dichloro methane 30 30 30
[0063] Each of the formulations thus obtained was further coated with a mixture prepared according to the composition described in Table 6 in order to protect amlodipine from light, to obtain a combination formulation. The combination formulations of Examples 9 to 11 are shown in Table 5. Titanium dioxide and HPMC 2910 were used for light-shielding, and polyethylene glycol 6000 (PEG 6000) and talc, as a plasticizer.
TABLE 6 Component HPMC Titatium PEG Distilled 2910 dioxide 6000 Talc Ethanol water mg/tablet 8 1.6 1.2 0.3 80 30
TEST EXAMPLE 1
Solubility Test of Solid Dispersion
[0064] The solid dispersions of Comparative Example 1 and Examples 1 to 3, and a simvastatin powder as a control were each subjected to solubility test in distilled water using a dissolution-test system under the following conditions according to the 1 st Basket method described in Korea Pharmacopoeia.
Dissolution-test system: Erweka DT 80 (Erweka, Germany) Effluent: 900 ml of distilled water Temperature of effluent: 37±0.5° C. Rotational speed: 50, 100 and 150 rpm Analytic method: liquid chromatography Column: Cosmosil C 18 (Nacalai tesque) Mobile phase: acetonitrile/pH 4.0 buffer solution Flow rate: 1.5 ml/min Detector: ultraviolet spectrophotometer (238 nm) Injection volume: 20 μl
[0075] The pH 4.0 buffer solution was prepared by mixing 3 ml of glacial acetic acid with 1 L of distilled water and adjusting the pH of the mixture to 4.0 with NaOH.
[0076] As can be seen in FIG. 2 , the solid dispersions of Examples 1 to 3 showed higher solubilities as compared to the solid dispersion of Comparative Example 1 or the simvastatin powder, and the solubility seems to increase with the amount of MYRJ rather than that of HPMC.
TEST EXAMPLE 2
Dissolution Test of Sustained Release Formulation for Amount of Active Ingredient
[0077] The sustained release formulations prepared in Examples 4 to 6 were each subjected to drug dissolution test under the following conditions according to the 2 nd Paddle method described in Korea Pharmacopoeia. The amount of simvastatin eluted from the formulation during the test was measured by liquid chromatography at 1, 2, 4, 6, 8, 10, 12, 16, 20 and 24 hrs after starting the test.
Dissolution-test system: Erweka DT 80 Effluent: 0.01 M sodium phosphate buffer solution (pH 7.0) containing 0.5% sodium lauryl sulfate (SLS) Temperature of effluent: 37±0.5° C. Rotational speed: 100 rpm Analytic method: ultraviolet spectrophotometer (247 nm and 257 nm) Calculation of eluted amount: Cumulative release amount
[0084] The sample harvested at each designated time was reacted with 40 mg of pre-washed MnO 2 (under USP Simvastatin Tablet 1) for 30 min and centrifuged at 3,000 rpm for 5 min. Then, the absorbances at 247 and 257 nm of each sample were measured using an ultraviolet spectrophotometer and the actual absorbance was calculated by subtracting the absorbance at 257 nm from that at 247 nm.
[0085] As shown in FIG. 3 , the formulations obtained in Examples 4 to 6 exhibit similar dissolution rates regardless of the difference in the active ingredient content.
TEST EXAMPLE 3
Dissolution Test of Sustained Release Formulation for Kind of Active Ingredient
[0086] The formulations prepared in Examples 7 and 8 were subjected to dissolution test according to the same method as described in Test Example 2, except for measuring the amount of lovastatin or fluvastatin instead of that of simvastatin.
[0087] As a result, FIG. 4 shows that the sustained release formulations of Example 7 and 8 exhibit similarly sustained dissolution rates each other, irrespectively of kinds of the HMG-CoA reductase inhibitor used therein.
TEST EXAMPLE 4
Dissolution Test of Combination Formulation
[0088] The formulations prepared in Examples 9 to 11 were subjected to dissolution test according to the same method as described in Test Example 2, except for using a high performance liquid chromatograph (HPLC) instead of a ultraviolet spectrophotometer (UV) under the following conditions.
Dissolution-test system: Erweka DT 80 Effluent: 0.01 M sodium phosphate buffer solution (pH 7.0) containing 0.5% sodium lauryl sulfate (SLS) Temperature of effluent: 37±0.5° C. Rotational speed: 100 rpm Analytic method: liquid chromatography Column: Cosmosil C 18 (Nacalai tesque) Mobile phase: acetonitrile/pH 4.0 buffer solution Flow rate: 1.5 ml/min Detector: ultraviolet spectrophotometer (238 nm) Injection volume: 20 μl
[0099] The pH 4.0 buffer solution was prepared by mixing 3 ml of glacial acetic acid with 1 L of distilled water and adjusting the pH of the mixture to 4.0 with NaOH.
[0100] As shown in FIG. 5 , the combination formulations of Examples 9 to 11 exhibit dissolution rates similar to those of the sustained release formulations of Examples 4 to 8. This suggests that the dissolution rate of the HMG-CoA reductase inhibitor is not much affected by the coating layers.
TEST EXAMPLE 5
Dissolution Test of Combination Formulation for Rotational Speed
[0101] The formulation prepared in Example 9 was subjected to dissolution test according to the same method as described in Test Example 4, except for setting the rotational speed at 50, 100 or 150 rpm.
[0102] As a result, FIG. 6 shows that the combination formulation of the present invention did not show any significant difference in the dissolution rates of the HMG-CoA reductase inhibitor even the rotational speed was changed. This suggests that side effects due to initial burst effect of the HMG-CoA reductase inhibitor would be significantly reduced when inventive combination formulation is administered to a patient.
TEST EXAMPLE 6
Dissolution Test of Combination Formulation
[0103] The combination formulations prepared in Examples 9 to 11, and the commercially available Norvasc® (Pfizer) as a comparative formulation were each subjected to a drug dissolution test under the following conditions according to the 2 nd Paddle method described in Korea Pharmacopoeia. The amount of amlodipine eluted from the test formulation during the test was measured by liquid chromatography at 15, 30, 45 and 60 min after starting the test.
Dissolution-test system: Erweka DT 80 Effluent: 500 ml of 0.01 N aqueous HCl Temperature of effluent: 37±0.5° C. Rotational speed: 75 rpm Analytic method: ultraviolet spectrophotometer (237 nm) Calculation of eluted amount: Cumulative release amount
[0110] As shown in FIG. 7 , the combination formulations of Examples 9 to 11 exhibit high amlodipine dissolution rates (90% at 30 min), similarly to the comparative formulation.
[0111] While the invention has been described with respect to the above specific embodiments, it should be recognized that various modifications and changes may be made to the invention by those skilled in the art which also fall within the scope of the invention as defined by the appended claims. | A complex formulation for oral administration comprising a sustained release formulation of an HMG-CoA reductase inhibitor and a film layer for rapid release of an anti-hypertensive agent, the film layer being coated on the sustained release formulation, can achieve improved therapeutic effects of the anti-hypertensive agent by promptly releasing it, while maintaining a constant drug level of the HMG-CoA reductase inhibitor in blood through a slow release. Accordingly, the complex formulation is useful for preventing and treating diseases such as hyperlipidemia, atherosclerosis, hypertension and cardiovascular disease. | 0 |
CROSS-REFERENCE TO RELATED APPLICATIONS
[0001] This application is a continuation-in-part of U.S. patent application Ser. No. 13/851,890 filed Mar. 27, 2013, which is hereby incorporated by reference in its entirety.
BACKGROUND OF THE INVENTION
[0002] The idea of using radioactive materials as direct power sources for applications requiring long-lived power sources has been investigated for many decades. Nuclear power sources for deep space probes have been used on many NASA programs especially those that last for decades and where the probes will not have sufficient sunlight for solar panels to operate. Nuclear Batteries, also called atomic batteries, have been developed that attempt to exploit the heat or thermal energy of the radioactive materials as well as the alpha and beta particle emissions energy through various means. Typically these devices tend to be large in comparison to typical electrochemical batteries and also tend to suffer from the emissions of high energy particles including alpha, beta, gamma and neutrons which create human health risks. Besides space probes, small nuclear power sources have been successfully used in devices such as pace makers and remote monitoring equipment.
[0003] One area of much research has to do with the direct conversion of beta emissions, i.e. electrons, emitted from radioisotopes that are targeted on a semiconductor material to develop electron-hole pairs and thus generate an electrical current in the semiconductor. All of these devices suffer from very low efficiencies due to the poor electron capture cross section of the designs as well as the semiconductor material itself. This is the same phenomenon that solar cells continue to suffer from even after decades of work and hundreds of billions of dollars of investment.
[0004] Researchers have recently begun investigating nanotechnologies with which to implement nuclear power sources. Some of these include the development of micromechanical devices that vibrate or rotate in response to charge build up within the semiconducting materials.
[0005] The underlying reason for pursuing the development of nuclear batteries is the much wider goal of developing long lasting, low cost power sources. Along these lines, there are many other fields of research that are producing some interesting and potentially viable power sources. In particular, fuel cells and new electrochemical battery technologies look particularly promising for small, low cost, high density and long-lived power sources but none come close to the energy density and longevity that nuclear power sources offer.
[0006] Prior art describes four basic methods of converting radioisotopes into useable energy sources. Three of these require a double conversion process wherein the radioactive sources are used to first generate heat, light or mechanical energy which is then converted into electrical energy. These multiple conversion processes have extremely low efficiencies which puts them at a distinct disadvantage to compete with the fourth method which is referred to as direct conversion.
[0007] Of the direct conversion methods, the two that are the most studied are the semiconductor PN junction conversion and the capacitive charge storage conversion. The semiconductor conversion processes, also known as betavoltaics, employs semiconductor technology that suffers from device degradation and very low efficiencies. The capacitive charge storage devices have problems with large size and very high voltages that can reach hundreds of thousands of volts that create materials challenges that can withstand such high voltages. These problems are magnified as the devices are scaled down.
[0008] A common problem for all of the prior art is that the amount of energy that can be extracted from the radioactive material is a very low level and at a consistent output which doesn't provide a practical means to support real world applications that demand varying amounts of power at different times.
[0009] Of the most relevant descriptions of a nuclear batter disclosed in prior art, Baskis, 5825839, describes a direct conversion nuclear battery utilizing separate alpha and beta sources isolated by an insulating barrier and two charge collector plates, one to collect the negative beta particles and a another plate collect the alpha particles. The two plates become charged and thereby storing the energy in the form of an electric potential the same as a capacitor stores electrical energy in the form of positive and negative charges on parallel plates. This approach utilizes the balanced alpha/beta charge approach as the present invention, but for completely different purposes. In the Baskis disclosure, a load place across the “battery” allows electrons to flow from the negative charged plate to the positively charged plate that is saturated with alpha particles. The recombination of the electrons and the alpha particles is said to produce helium gas which is vented out of the cell. However, this description does not address the recombination of “free” electrons in the metal plate combining with the alpha particles producing He gas directly. However the net effect is the same, the positive plate will become increasingly positively charged by the alpha particles producing a stored electric potential across the device.
[0010] The preferred embodiment of the present invention also suggests the use of balanced alpha and beta charges for greater efficiencies, however, such a requirement is not necessary for it to operate. Additionally the present invention can store the energy of the alpha and or beta particles in chemical energy form as a chemical battery as well as in electric potential energy as in a capacitor, as described in alternative embodiments.
BRIEF SUMMARY OF THE INVENTION
[0011] The present invention incorporates aspects of four different energy generation and storage technologies, those being: Nuclear beta and/or alpha direct conversion, fuel cells, rechargeable electrochemical storage cells and capacitive energy storage. In the present invention, a radioisotope, or a mixture of radioisotopes, that emits beta and/or alpha particles is used as the primary energy source while an electrochemical cell is used as both a secondary energy source as well as an energy storage mechanism and a capacitor that may be used as a primary storage device as well.
[0012] This disclosure illustrates the core concepts for the construction and manufacture of the device but by no means limits the actual materials to only those used as examples and discussed herein nor the embodiments described. For example, almost any radioisotope can be used as the primary fuel source for this invention but those that are, at this time, considered safer, more optimal or more readily accessible are more desirable, especially for devices that could be used for equipment that will be in close proximity to humans or animals. As research continues and future advanced occur, it may become feasible that other radioisotopes may be well suited for use in this device and the following discussions are by no means intended to limit the invention to only the specific materials used or discussed herein. This is true for the materials used including those for the electrochemical and capacitive storage materials as well.
[0013] Additionally, no limitations to the embodiments of the described invention are to be inferred. This disclosure is to be interpreted in its broadest sense as to any materials that can be used as well as to the physical embodiments in which the concepts can be applied. For instance, there are hundreds of radioactive materials that can emit alpha and or beta particles and electrochemical batteries and capacitors can be built in an unlimited number of shapes, sizes, storage capacity, energy densities or materials. There are also many rechargeable battery chemistries that can be used in said present invention and no limitations as to the type of rechargeable battery or chemistry that can be used to implement such a device is implied.
[0014] Any radioisotopes or combination of radioisotopes that emit alpha and or beta particles can be used for this device. However, because the device takes advantage of both the positive charges of the alpha particle and the negative charge of the beta particle, to generate dc current directly as well as to provide a charging mechanism for the electrochemical cell, radioisotopes that produce both particles are expected to produce greater energy density and efficiencies than isotopes that produce only alpha or beta particles, however any combinations of radio isotopes or individual radioisotopes can be used. Radioisotopes that produce low energy alpha and or beta particles are particularly useful in this application since the emissions can be contained within the structure itself, thus eliminating the health issues of ionizing gamma and or neutron radiation. Isotopes that produce gamma rays and high-energy neutron are less desirable due to their associated health risks, and the inability to completely contain these emissions within the power cell itself. However, the power cell can be adapted for their use for certain applications where these issues are not a concern, for instance in generating electrical energy from nuclear waste products stored in long term storage facilities. In this case, the hazardous material is already placed in secured facilities where the high-energy emissions cannot harm persons or the environment. Using any or all available radioisotopes to generate electrical energy would be a good use for this invention. Additionally, space probes could, from a human safety standpoint, use any radioisotope material.
[0015] While the invention has been described with reference to some preferred embodiments of the invention, it will be understood by those skilled in the art that various modifications may be made and equivalents may be substituted for elements thereof without departing from the broader aspects of the invention. The present examples and embodiments, therefore, are illustrative and should not be limited to such details.
BRIEF DESCRIPTION OF THE DRAWINGS
[0016] FIG. 1 illustrates a cross-section of a device according to a preferred embodiment of the invention.
[0017] FIG. 2 illustrates a stacked cell configuration.
[0018] FIG. 3 illustrates an internal self-recharging process.
[0019] FIG. 4 illustrates an attachment and use of an external DC charge circuit.
[0020] FIG. 5 illustrates a discharge process.
[0021] FIG. 6 illustrates an embodiment of an implementation in a form of a standard cylindrical battery that is commonly available.
[0022] FIG. 7 illustrates a layered approach of placing an amorphous semiconducting material capable of producing large amounts of electron-hole pairs through bombardment of alpha or beta particles.
[0023] FIG. 8 illustrates the use of collector plates in or near the amorphous semiconducting material to aid in the collection of electron-hole pairs before they can recombine.
[0024] FIG. 9 illustrates the use of a mixture of radioactive material and amorphous semiconducting material in the cell.
[0025] FIG. 10 illustrates the cascade of electron-hole pair production within a mixture of the radioactive material and the amorphous semiconducting material.
DETAILED DESCRIPTION OF THE INVENTION
[0026] For the following discussion, refer to FIG. 1 . The device 10 , comprises a rechargeable electrochemical cell 20 , such as a Lithium Ion cell, which may be comprised of a cathode plate 19 such as aluminum, a Li ion capture material 18 such as LiCoO2 (or LiMnO2, or others), an electrolyte material 17 such as a lithium salt dissolved in organic solvent with a semipermeable membrane 16 separating the anode and cathode sides of the cell, a carbon anode 14 with an plate 13 such as copper, a layer of radio isotope material or a mixture of radio isotope materials 12 which emit alpha and or beta particles, with a bonding (agent not shown) and a proton exchange membrane layer 11 that is comprised of a highly negatively charged material, and a dielectric insulating layer (not shown). These layers can be rolled up to produce a typical cylindrical battery device, referred to in the industry as a “jelly roll,” and shown in FIG. 6 , or stacked on top of each other in many layers to produce irregular shapes and sizes that would be used in consumer electronic devices as shown in FIG. 2 . While the secondary battery technology described herein happens to be a Li-Ion type battery, any battery storage technology compatible with this invention can be used, and a person skilled in the art of battery chemistry and technologies could easily adapt any battery technology to be useful in this invention.
[0027] The amount of radioisotope material that would be needed in a particular power cell would depend upon the activity level of the particular material used and the amount of energy that the power cell would need to provide for a specific application.
[0028] FIG. 2 shows a cross section a stacked cell implementation of the invention as the cells would exist relative to each other. This orientation would exist whether individual cells are stacked on top of each other or a long single cell was rolled up into a cylindrical shape. In FIG. 6 , the layers of the cell would be rolled up upon themselves to create a cylindrical form similar in size and shape of common commercially available batteries such as “AA”, “AAA”, “C” and “D.” Of course any shape or size can be constructed by stacking the layers shown in FIG. 2 . When stacking layers, the PEM (Proton Exchange Membrane) layer 11 would be located between the radioisotope material layer 12 and the cathode plate 19 . Also note that the cathode plate 19 and the anode plate 13 are offset with respect to each other and with respect to the PEM layer 11 so as to prevent shorting the cells when they are assembled as well as to allow each cathode plates 19 to be connected together on one end or side of the cell and the anode plates 13 to be connected together on the other end or side of the cell. This also provides a means to connect the anode and cathode to the cell contacts for external connections.
Theory of Operation
[0029] Refer to FIG. 3 for the following discussion. A key aspect to the invention is the adoption of a proton exchange membrane 11 (PEM) similar to that used in fuel cell technologies. A common type of material used for this application is Nafion. There are a number of proton exchange membranes available that can be used in the present invention. In fuel cells, the PEM is a highly electronegative porous material that allows the positive charged “protons” to cross the membrane boundary between the anode and cathode while repelling the disassociated electrons and forcing them to flow around the cell, through an external circuit. These PEM characteristics are exploited in the present invention to allow the doubly positively charged alpha particles 23 , which are approximately the same size as methanol “protons” to pass through the PEM material 11 and collect in the cathode plate 19 , while forcing the beta particles 22 , i.e. electrons, to flow to the anode plate 13 and collect there. The positive charges carried by the alpha particles 23 and captured by the cathode plate 19 and the negative charges carried by the beta particles 22 and captured by the anode plate 13 will migrate to their respective cathode 18 and anode 14 regions causing the cell 10 to store the charges. These charges would then cause the lithium ions 20 to migrate from the cathode 18 through the electrolyte region 17 , across the separator membrane 16 , further across the solid electrolyte interphase (SEI) layer 15 , which is formed upon first charging, and finally to in situate themselves, intercalate, within the carbon layers of the anode 14 , thus completing the charging cycle for a pair of alpha 23 and two beta 22 particles.
[0030] Referring to FIG. 5 , when an electrical load is placed across the anode plate 13 and cathode plate 19 , an electric circuit would be completed causing electrons from the anode 14 to migrate to the anode plate 13 , through the external circuit 26 and returning to the cell at the cathode plate 19 . The ideal cell would be achieved when amount of radio isotopic material 12 and the external electrical load 26 were balanced where the total electrical current emanating from the radioisotope region into the anode plate 19 and cathode plate 13 were to equal the amount used by the electrical load 26 . This is an ideal condition that is unlikely to ever be achieved. Normally electrical loads have varying power requirements and this is where the rechargeable electrochemical storage portion 20 of the cell 10 plays it role. It will provide additional power to the load 26 when it is needed and it will store the excess energy coming from the radio isotope material 12 for later use.
[0031] If an electrical load were connected across the anode plate 13 and cathode plate 19 , an electric circuit would be completed causing electrons from the anode 14 to migrate to the anode plate 13 , through the external circuit 26 and returning to the cell at the cathode plate 19 . The ideal cell would be achieved when amount of radio isotopic material 12 and the external electrical load 26 were balanced where the total electrical current emanating from the radioisotope region into the anode plate 19 and cathode plate 13 were to equal the amount used by the electrical load 26 . This is an ideal condition that is unlikely to ever be achieved. Normally electrical loads have varying power requirements and this is where the rechargeable electrochemical storage portion 20 of the cell 10 plays it role. It will provide additional power to the load 26 when it is needed and it will store the excess energy coming from the radio isotope material 12 for later use.
[0032] Referring to FIG. 4 , as with any secondary electrochemical cell, the present invention can be recharged by means of an external charging circuit 25 placed across the cathode plate 19 and anode plate 13 . The charging circuit 25 injects electrons 21 into the anode plate 13 which migrate into the anode carbon layer 14 and speed up the lithium ion battery charging process as shown in FIG. 3 .
[0033] During discharge, the beta particles 22 (electrons) emitted by the radio isotope layer 12 will flow directly through the anode plate 13 to power the external load 26 while the alpha particles will accumulate at the anode, completing the circuit. The current developed from the radioisotope material 12 will power the load reducing the draw from the stored energy of the secondary electrochemical battery cell 20 . However, when the current drawn by the load 26 is less than the current developed by the radioisotope material 12 , then the excess current will charge the secondary battery cell 20 , thus acting as a charging circuit for the secondary electrochemical storage battery 20 , the same as if the secondary battery were being charged from an external charging device 25 .
[0034] Because of the affinity of the anode 14 to accept electrons and the highly electronegative characteristics of the proton exchange membrane (PEM) 11 , the beta particles 22 are attracted to the anode plate 13 and collect there developing an overall negative charge on the plate which is transferred to the anode carbon layer 14 . The increasingly negatively charged carbon anode 14 attracts positive lithium ions 20 from the electrolyte 17 causing the migration of the lithium ions 20 from the lithium metal oxide cathode 18 . At the same time, the alpha particles 22 are attracted by the overall negatively charged proton exchange membrane (PEM) 11 and migrate towards it. The PEM 11 doesn't have any binding sites for the alpha particle and its physical properties allow the alpha particles 22 to pass through it to the cathode plate 19 where they are able to bind with the cathode plate 19 and transfer their positive charges to the cathode plate 19 , thereby oxidizing the cathode layer 18 and liberating more lithium ions 20 to migrate across the cell to the anode 14 .
Alternative Embodiments
[0035] Since the radioisotope material 12 continually emits alpha and/or beta particles 22 and 23 , at some point the battery will become fully charged with all Lithium ions 20 being intercalated within the carbon material of the anode 14 but the radioisotope material 12 will still be developing an electrical potential. Some of this unused electrical potential can be stored in an integral super capacitor (not shown in drawings) surrounding the entire battery device but inside the enclosure 31 .
[0036] The super capacitor is created by connecting one thin metal plate (not shown in drawings) to the anode plate 13 , another thin metal plate (not shown in drawings) attached to the cathode plate 19 and a thin insulating material (not shown in drawings) separating said plates. However, depending upon the total energy storage capacity of the device and the system load demands, eventually one of two conditions will occur.
[0037] Either the cell will be completely depleted or it will become fully charged. In the event of a full charge within the electrochemical cell and any integral capacitor of the battery, the excess energy will have to be exhausted as heat. This excess energy is most effectively released through a resistive material (not shown in drawings) around the outer surface of the cell but inside the protective metal enclosure 31 or incorporated as an integral part of said enclosure 40 , so as to radiate off excess energy as heat into the surrounding environment. A built-in charging and discharging control circuit can be used to control the excess energy bleed off.
[0038] A second situation exists where the device becomes completely discharged and cannot provide sufficient power for the intended load. At this point, the equipment which is powered by the device is turned off or the power cells are changed out for fresh cells. In either circumstance, the radioisotope will recharge the cell. Current lithium battery technologies limit discharge to about 40 percent. A deep discharge will damage the battery and limit its lifespan. This situation is prevented by a charge control circuit which will prevent battery damage due to overcharging or over discharge.
[0039] Alternatively, a standalone self-charging nuclear capacitor is made by applying a thin layer of the radio isotope to one side of a thin metal foil then a layer of the PEM material over the radio isotope combined with a binding material followed by the second metal foil layer and finally a dielectric membrane is placed on the top of the second foil layer. These layers are then rolled up so that the two metal layers are separated by the dielectric membrane. The metal foil layers are chosen just as in any electrolytic capacitor so that the plates have a propensity to attract and store positive or negative charges. An example would be aluminum and tantalum foils.
[0040] As described above, this capacitor can be implemented directly in the nuclear rechargeable electrochemical power cell by adding the capacitor layers sandwiched in the radioisotope layer. If the cell design characteristics are chosen to incorporate a high voltage capacitor to store more power, a voltage regulator would be needed to regulate the charge voltage for the electrochemical cell to protect it from damage from over charging and over voltage. A large amount of energy can be stored within this super capacitor that can be used for loads that demand very high currents for very short periods of time or if regulated can produce lower voltages for longer periods of time, or even other voltages than that of the battery.
[0041] Since alpha particles possess a positive double (+2) charge, they are easily deflected by electric or magnetic fields. The electric field generated by the cell construction, with or without the high voltage capacitor may be effective in driving the alpha particles towards the cathode collector plate and thus, increasing efficiency. Similarly, the addition of a magnetic material layer that creates a magnetic field that directs the alpha particles towards the cathode may also be effective in increasing efficiency. These same phenomena may also serve to push the electrons towards the cathode as well.
[0042] The amount of radioactivity emissions from materials that are generally considered “safer” than other radioactive materials tend to be too low powered for use as a direct energy source for present day electronic devices. The goal of designing a high energy, long lasting and safe nuclear power source is confounded by fundamental material limitations where the amount of energy emitted is roughly inversely proportional to the half-life of the material. That is, the higher the energy output, the shorter the half-life. The goal is to develop devices that can last many years to several decades that can also produce the sufficient output power to run electronic devices or system without undue risks to human life or the environment.
[0043] Research into betavoltaics using P-N junctions in silicon and other semiconductor materials has been focused on creating electron-hole pairs near the P-N junction of the semiconductor material. These electron-hole pairs develop a voltage and current across the P-N junction when a beta particle is ejected from the radioactive material and travels through the semiconductor material. Much research has been spent on building 3D structures within the semiconductor materials to hold the radioactive material in such a manner that would capture as many beta particles as possible to produce the most electron-hole pairs as the beta particle travels through the semiconductor material. Some research suggests that as many as 2000 electron-hole pairs can be generated with each beta particle emitted from a tritium source. There are a couple major problems with this approach. The first being that these techniques require expensive silicon wafer production facilities and their associated high costs for the base semiconductor wafers. The second is that the semiconductor materials deteriorate from lattice destruction caused by the kinetic energy of the beta particles. These devices tend to fail in a relatively short period of time (months to a few years) from even the lowest energy beta emitters. Destruction of the P-N junction and semiconductor lattice structure renders the already low efficiencies of this method to steadily decrease over time.
[0044] To increase the electron-hole generation in the present invention, a layer of amorphous semiconducting material, or any other material found to be generous electron-hole pair generator, can be applied on either or both sides of the radioactive source material that will generate a cascade of electron-hole pairs as the alpha and or beta particles travel through it. See FIG. 7 . Since the present invention doesn't rely on a P-N junction to develop a voltage differential across the cell, very inexpensive amorphous semiconductor material of various kinds can be used as the electron-hole generation material. The electric field developed by the cell chemistry will naturally draw the electrons towards the anode plate while the holes will be drawn to the cathode plate. Recent research has shown very low cost amorphous metal oxide materials to be effective electron-hole generators as well. Additionally, since amorphous materials contain neither a P-N junction nor a regular lattice structure, electron-hole pairs can be generated for long periods of time without the concern of the material experiencing structure breakdown. A secondary benefit is that these materials are very inexpensive.
[0045] Research has also shown that the effective electron-hole generation capabilities of low energy beta emitters such as tritium extend only a few hundred microns deep into a semiconductor material. Two of the main processes that contribute to the inherent low efficiencies of the semiconductor P-N betavoltaic approach are that there is a high rate of reabsorption of the emissions from the bulk radioactive material and the recombination of the electron-hole pairs in the semiconductor material. The rate of reabsorption is proportional to the thickness of the bulk material used in the cell. If the radioactive material is thicker than a few hundred microns then the rate of reabsorption increases with the additional thickness since only those emissions close to the surface of the material are likely to escape to be used to generate power. On the other hand semiconductor P-N junctions that are deposited on the surface of a semiconducting chip structure are unable to capture many of the electron-hole pairs generated at deeper layers of the semiconductor because the electron-hole pairs have a greater chance of recombining within the bulk semiconductor body before they can migrate through it and combine at the anode and cathode to contribute to the cell's power output.
[0046] By depositing the radioactive material in a very thin layer, something on the order of hundreds of microns, the reabsorption can be reduced and almost eliminated since most of the emissions will be close enough to the surface of the material to escape into the surrounding materials where they can be captured and used for power generation. Since the distance that a particle will travel through a solid material depends upon its energy as well as the material it is traveling through, the optimal thickness of the radioactive material layer will probably be determined based upon these factors for various cell chemistries. This thin layer approach is the optimum structure for a radioactive material based power cell. When structured in this fashion, essentially all the emissions from within the radioactive material will be able to escape the bulk material and thereby limit the reabsorption effects. This is because the radioactive source material layer would be so thin that most of the emissions would have a high probability of escaping from the large surface areas of the layer and only the relatively few emissions that occur along the axis of the layer would have a high probability of recombination. See FIG. 7 . By placing layers of a semiconducting material 45 on one or both sides of the radioactive material layer, the kinetic energy of the escaping alpha and beta particles can be used to generate electron-hole pairs in the semiconducting material. This is described in greater detail below.
[0047] Referring to FIG. 10 . When alpha or beta particles are spontaneously emitted from the radioactive source material, they will invariably run into other atoms and release some of their kinetic energy to those atoms. A small percentage of these interactions result in an electron of the target atom being knocked free. The freeing of an electron 49 from an atom results in the atom having an overall positive charge. This is referred to as a “hole” and is denoted as “h + ” 50 . This process is shown in FIG. 10 . The physical interaction of the alpha particle 47 and the beta particle 48 within the semiconducting material can result in the formation of an electron-hole pair 51 . If the electron 49 is knocked free from the target atom so that it cannot immediately recombine with the positive hole 50 then the two charges have a chance to migrate across the cell and be absorbed by the anode 13 and cathode 19 . If the electron is immediately recaptured by the target atom from which it was liberated, or another atom with a positive charge, then the two charges will cancel out and no useful energy can be obtained. This is known as recombination. Since the amount of energy needed to free an electron in the semiconducting material is much much lower than the energy of the impinging alpha or beta particle, many electrons can be liberated and many holes formed within the semiconducting material before the particle's kinetic energy is absorbed. This process creates a cascade of electrons 49 and holes 50 from a single radioactive particle. FIGS. 7, 8 and 9 show variations of cell construction that can be used to optimize the electron-hole generation and capture based upon various cell chemistries and radioactive source particle energies. FIG. 10 shows the electron-hole generation that occurs within a mixture of radioactive source material and an amorphous semiconducting material. In this application, shown in FIG. 9 , the overall thickness of the mixture would necessarily need to be much thicker than the very thin layer of the pure radioactive layer described earlier in order to increase the probability that the particles will interact with many semiconductor material atoms to generate the greatest amount of electron-hole pairs 51 . The down side to a thicker layer is the higher probability of recombination as the electrons and holes migrate across this layer. Experimentation with the radioactive source material and the semiconducting material will need to be done to optimize the layer 46 thickness. The optimal thickness of 46 will, of course, depend upon the nature of the materials used.
[0048] Referring back to FIG. 7 , with a thin layer of amorphous semiconducting material 45 , or any other material found to be a generous electron-hole pair generator, on one or both sides of the radioactive material layer 12 , a single alpha or beta particle emission can be amplified hundreds or even thousands of times through interaction with the amorphous semiconducting material as shown in FIG. 10 . The resulting electrons 49 and holes 50 will migrate across the semiconductor and radioactive material regions towards the appropriate cell plates. The longer migration path will increase the probability that the electrons and holes recombine before they reach the opposite plate.
[0049] The thickness of the semiconducting layers 45 will require experimentation to determine the optimal thickness. Two competing processes will tend cancel each other out. First, if the semiconducting layer is too thin then too many of the alpha particles 23 and beta particles 22 will pass through the layer without creating a cascade of electron-holes 51 . Therefore, the thicker semiconductor layers 45 are, the greater the capture rate and the greater the electron-hole generation. Competing with that process is the rate of recombination which increases as the distance that the charges have to travel to reach the anode and cathodes increases. Just as in a betavoltaic semiconductor direct conversion device, a too thick amorphous semiconductor material layer will allow too many of the electron-hole pairs to recombine within the material itself canceling out their electrical usefulness in the cell.
[0050] Another issue to consider in cell construction are the electrical characteristics of the radioactive source material. The electrons 49 or holes 50 may not be able to migrate across the radioactive material layer either because the radioactive material may itself be a natural electrical insulator which would inhibit charge migration or perhaps it may have metal characteristics that promote the recombination of the electrons 49 and holes 50 as they migrate from the semiconducting material regions 45 across the radioactive source material region 12 . A solution to this problem, see FIG. 8 , could be to place porous collector plates 41 & 42 in or around the semiconducting material regions 45 with collector plate 41 connected to the anode 13 through connector 43 and collector plate 42 connected to the cathode 19 through connector 44 . The collector plates 41 & 42 and associated connections 43 & 44 would provide a direct path for the charges to reach the cell anode 13 and cathode 19 and would reduce the distance that they would have to travel through regions 12 & 45 which in turn would reduce the probability of recombination and eliminate the potential electrical characteristics issues of the radioactive source material. In this embodiment the collector plate 41 would allow the alpha particles 47 , and the holes 50 to pass through it to collect on the cathode plate 19 , while collecting the beta particles 48 the electrons 49 while also providing a low impedance path through connection 43 to the anode 13 . Conversely, collector plate 42 would allow beta particles 48 and electrons 49 to flow through it to the anode 13 while collecting the alpha particles 47 and the holes 50 while also providing a low impedance path through connection 44 to cathode 19 .
[0051] See FIG. 9 . Yet another embodiment would be to mix the amorphous semiconductor material with the radioactive material, as described above, and applying the mixture in a thin layer 47 that would allow the alpha and beta particles along with the electron-hole pairs they create to migrate across this region without a great probability of recombination or reabsorption could be a very effective technique. In this case, the alpha and beta particles 47 & 48 respectively, along with the electron-hole pairs 50 generated within the amorphous semiconducting material would migrate to the appropriate plates under the influence of the cell's electric field, thus producing far greater output capacity than the alpha and beta particles alone. One potential benefit to this embodiment is that the semiconducting material would work to counteract the electrical characteristics of the radioactive source material. The semiconducting material would act as a low impedance path for radioactive source material that is a natural insulating material but would have an insulating effect on those radioactive source materials that are metallic in nature and therefore good natural electrical conductors. The net result would be a beneficial semiconducting medium that produces cascades of electrons 49 and holes 50 for each alpha particle 47 and beta particle 48 . Again, experimentation to determine the optimum thickness of layer 46 and the relative amounts of the radioactive source material and semiconducting material would be required. This layer's characteristics will also be greatly influenced by the materials used.
[0052] While the terms amorphous semiconductor and semiconductor are used to describe a preferred embodiment of this technique, it is not to be interpreted to be the only kind of material state that can be used to generate the electron-hole pairs. In fact, any mater or materials that produce electron-hole pairs when bombarded with radioactive particles whether amorphous, crystalline, polysilicon, nano-materials or any other forms, can be a suitable potential source material for the present invention.
External Charging
[0053] The inherent nature of the self-recharging battery does not preclude the capability of a fast charging in an external charging device. A nuclear battery of this design can be quickly charged by means of inserting it into an external battery charger, similar to existing battery charging devices using standard charging techniques.
[0054] A self-monitoring circuit to indicate to the user the level of charge that the cell has at any given time can be incorporated into the device. Since the radioisotope would continuously charge the device, especially when it is not in use, power cells using this technology can be swapped out of equipment, set aside, and they will recharge automatically. Alternatively, they could be charged more quickly by an external charger device. The charge indicator would be powered by the device directly and would let the user know how much power is available at any given time.
[0055] An electronic circuit that could control the internal and external charging and discharging characteristics of the battery could be incorporated as a safety/security aspect of the device. This circuit could be used to control the total charge of the battery as well as to disable the battery recharge system to prevent automatic self-recharging or external recharging. This functionality would be useful in a battlefield situation where the battery may be lost or stolen. In such a situation, the battery could be rendered useless, or at least prevented from recharging. Such a system can be implemented by incorporating a built in electronic chip/circuit that would enable or disable recharging or it could force discharging of the battery under specific conditions through the resistive load material used to bleed off excess power. For instance, such a condition may be where a warfighter would carry a tiny wireless control device (perhaps built into some other equipment) that would communicate with the battery controlling its functionality. Should the battery become lost or stolen and unable to communicate with some approved remote control device, the battery could automatically render itself useless, either by discharging or not allowing itself to be recharged externally or internally, thus rendering it useless to anyone but those with the correct controller devices.
[0056] This same wireless control circuit could be used as a locator beacon that could be activated under any number of predefined conditions such as tampering or destruction of the cell in an attempt to obtain the nuclear materials.
[0057] While the invention has been described in detail and with reference to specific embodiments thereof, it will be apparent to those skilled in the art that various changes and modifications can be made therein without departing from the spirit and scope thereof. Thus, it is intended that the present invention cover the modifications and variations of this invention provided they come within the scope of the appended claims and their equivalents. | A method and apparatus for collecting and storing the energy emitted by radioisotopes in the form of alpha and or beta particles is described. The present invention incorporates aspects of four different energy conversion and storage technologies, those being: Nuclear alpha and or beta particle capture for direct energy conversion and storage, fuel cells, rechargeable electrochemical storage cells and capacitive electrical energy storage. | 7 |
BACKGROUND OF THE INVENTION
[0001] 1. Field of the Invention
[0002] The invention refers to a device for producing in particular reproducible medicinal foam or bubble suspension of a gaseous and a liquid medium. In particular, the invention refers to a mixing device for a reproducible preparation and administration of injectables such as sclerosing agents, diagnostic agents, therapeutic agents, homeopathic agents and autologous blood, for example.
[0003] 2. Related Prior Art
[0004] Sclerotherapy means the planned elimination of intracutaneous, subcutaneous and/or transfascial varices and the sclerotization of subfascial vessels in case of venous anomalies by injecting a sclerosing agent. The various sclerosing agents cause damage to the endothelium of the vessels. Thereafter, a secondary vascular occlusion occurs and, in the long term, the veins are transformed into a strand of fibrous tissue, i.e. sclerosis occurs. It is the purpose of the sclerotization treatment to definitely transform the veins into a fibrous strand. This can not recanalize and, in its functional result, corresponds to the surgical procedure for removing a varice. Besides a sclerotization with liquid sclerosing agents, the sclerotization with foamed sclerosing agents becomes ever more important. The foam remains in vein for a longer period. Here, surfactant sclerosing agents, such as Polidocanol, are most often made to achieve a foamy state by pumping the agent back and forth between two pumps or by shaking, whereafter it is injected in a conventional manner. At present, there is no approved technique that would allow a reproducible preparation of a standardized foam.
[0005] Further, a plurality of preparations suited for use as ultrasonic contrast media are known, some of which contain surfactants that support the formation of bubbles and stabilize these. The bubbles or a foam reflecting ultrasound are the true contrast medium and are produced only immediately before being administered.
[0006] A mixing device for producing medicinal foam or for producing bubbles is known from EP 0 564 505. Here, a mixer with a helically shaped mixing element is described. The mixer is an accessory element that may be permanently connected to a syringe. When a liquid and/or gaseous medium is expelled from a second syringe, the medium reaches the mixer that contains the gas in a defined volume and nature. Here, the gaseous phase and the liquid phase are mixed along the helical mixing element. Thereby, a therapeutic and/or diagnostic foam may be produced. Due to the helical mixing elements arranged in the mixer, the mixer is a component that can only be produced as an injection molded part with intricate injection molds.
[0007] Especially in producing foams for medicinal use, especially for sclerotherapy, it is necessary to produce a sterile foam. Should air be used to produce foam, it is possible to aspire air through a sterile filter into a syringe and to use the sterile air thus obtained to produce foam. However, this has the drawback of requiring an additional step and an additional component in the form of the sterile filter. This increases the costs. Further, the volume of waste is augmented.
[0008] It is further known from GB 2 369 996 to close a syringe filled with sterile air using a three-way valve. A second valve is filled with an active agent and is also connected to the three-way valve so that the syringes are oriented under an angle of 90° to each other. Thereafter, the three-way valve is rotated to a position in which both syringes are in communication so that by pumping the gas and the active agent back and forth, foam can be produced. Closing a syringe filled with sterile air using a three-way valve has the drawback that, for example, during transport or handling, inadvertent opening and thus a contamination and/or a change in the gas volume can occur. Furthermore, the handling of this system is complex, since after both syringes have been connected to the three-way valve, the latter also has to be opened. Moreover, it is difficult to produce a reproducible foam with this device, since the diameter of the passage changes already at a slightly false position of the three-way valve. This can cause the production of a foam with a different size of bubbles. Further, the orientation of the two syringes under an angle of 90° is disadvantageous, since this makes the handling more difficult.
[0009] Typically, after the production of foam both syringes contain foam. With the device described in GB 2 369 996, for therapy, one of the syringes filled with foam has to be unscrewed from the three-way valve. In order to additionally inject the foam remaining in the second syringe at a later time, if necessary, it is required to close the three-way-valve so as to avoid contamination. To then inject the remaining foam, the first syringe just used for therapy must be screwed to the three-way valve again and the valve has to be opened, to then transfer the remaining foam into the injection syringe, for example. Thus, this procedure is extremely complex.
[0010] It is an object of the invention to provide a device for producing medicinal foam from a gaseous and a liquid medium, the device being adapted to meet high sterility demands.
SUMMARY OF THE INVENTION
[0011] The present device for producing medicinal foam that is particularly suitable for use in scleroscopy, comprises a gas vessel for holding a sterile gas, especially sterile air. Further, an active agent vessel for holding a usually liquid active agent is provided. Preferably, both vessels are syringes, in particular disposable syringes. Both vessels are adapted for fluidic connection to a connecting element. Moreover, a feed means is provided for conveying the gas and the active agent back and forth between both vessels so as to produce the medicinal foam. In a preferred embodiment, the feed means comprises two feed elements, each feed element being connected with one of the two vessels, respectively. Preferably, the feed elements are the syringe pistons.
[0012] According to the invention, the connecting element is connected with one of the vessels, preferably the gas vessel. The connection is obtained for example by screwing, especially by means of a Luer lock. Similarly, the connecting element may be permanently connected with the vessel, e.g. glued thereto or formed integrally therewith. Specifically, the hub with the opening of the syringe can be formed as a connecting element. Preferably, the connecting element is surrounded by the Luer lock. According to the invention, the connecting element comprises a closure element for the sterile closing of the vessel. Thus, it is possible to provide a sterile gas, e.g. sterile air, in one of the two vessels, especially in the gas vessel, which can not escape from the vessel because of the closure element provided. An undesired intrusion of non-sterile air is also avoided because of the closure element provided according to the invention. Thus, in a particularly preferred embodiment, the connecting element is configured such that in the unconnected state, i.e. especially before the gas vessel together with the connecting element is connected to the active agent vessel, both an intrusion and an escape of gas and/or liquid into or from the vessel closed by the closure element is prevented. This has the advantage of ensuring a very good sterility of the medium contained in the vessel. Further, it is ensured that an unintentional change of the gas volume is avoided. Thereby, a good reproducibility of the medical foam is ensured.
[0013] Preferably, the closure element comprises a resilient rubber stopper. The stopper may comprise a slit serving to open the closure element. The slit is configured such that the slit walls abut each other in the unconnected state and close the vessel tightly, such that an intrusion or an escape of gas and/or liquid is avoided.
[0014] Preferably, the closure element is opened automatically upon connecting the connecting element with the second vessel, in particular the second syringe. In a preferred embodiment, this guarantees that by opening in the manner provided by the invention contamination is avoided by the connection, other than when removing a closure element in the form of a lid or the like. Further, no additional step such as removing a lid or opening a valve is required. According to the invention, this specifically allows to provide a closure element with a significantly lower risk of contamination.
[0015] The present device for producing medicinal foam has the particular advantage that the sterile gas is preferably already present in a sterile condition and does not have to be obtained first through a sterile filter. Further, due to the automatic opening, the gas remains sterile so that an inadvertent contamination by aspiration is avoided. Moreover, it is guaranteed that the exactly defined volume of gas, and thus the mixing ratio of gas and agent, will not be corrupted for example by an unintentional escape of gas. Thus, it is possible to produce a reproducible foam and to create a standard.
[0016] Creating a high standard or a high uniformity of the foam producible with the present device can be improved further by also prefilling the second vessel. To this effect, the second vessel, which is especially the active agent vessel, is closed by a closure member. The closure member may be configured similar to the closure element, in particular as a membrane or a plastics stopper. When two prefilled vessels are provided, one of which is closed with the connecting element including the closure element, this is further advantageous in that a further process step, i.e. filling the still empty vessel, usually the active agent vessel, can be omitted.
[0017] Preferably, the closure element is opened by penetrating a membrane of the closure element. The penetration of the membrane may be effected by a hub on the second vessel, especially provided at the syringe, in particular the hub of a Luer lock. In particular, the closure element is opened such that the process is reversible and the closure element therefore closes the vessel again, when in the unconnected state. Specifically, the membrane or the plastics stopper are configured such that it has a slit which may be spread open by means of a tubular element, for example, and closes again when the tubular element is withdrawn.
[0018] In a particularly preferred embodiment, the connecting element comprises a tube element. When connecting the second vessel with the connecting element, the membrane is penetrated by the tube. For this purpose, the closure element and/or the tube element are preferably arranged for displacement in the connecting element. Here, the tube element is preferably held fixed in the connecting element so that a displacement of the closure element causes a penetration of the membrane by the tube element. The closure element is preferably displaced by a hub of the vessel, in particular the Luer lock hub of a syringe.
[0019] As soon as the vessels are connected through the connecting element, the gas and the active agent can be pumped back and forth between the two vessels, in particular the two syringes, to produce the sterile foam. In doing so, the gas and the active agent preferably flow through the tube element. Specifically, there is no flowing around the closure element. This is advantageous in that clearly defined flow paths and thus a clearly predeterminable flow behaviour are given. This increases the reproducibility of the medicinal foam.
[0020] To ensure a secure closing of the first vessel prior to the connection with the second vessel, the closure element is preferably spring-loaded. Upon opening the closure element, the closure element is preferably urged against the spring force. The spring force may be caused, for example, by a coil spring or another resilient element. The provision of such a closure element guarantees that the filling amount in the vessel remains constant and is not changed, e.g., during transport or handling. Further, the gas vessel can be closed again and has good sterility.
[0021] Preferably, the connecting element comprises a mixing element. It is particularly preferred that the tube serving to open the membrane is designed as a mixing element. It is sufficient to provide a tubule with a small cross section so that turbulences are generated by the change in cross section, which turbulences serve to intermix the active agent with the gas. The tube element, preferably made of stainless steel or having a coating resistant against the active agent, has an inner diameter of up to 3 mm, for example. One of the openings of the tube may have its cross section reduced directly or indirectly by providing an additional element. The cross section is preferably reduced to a cross section of 0.3-2 mm. Tests have shown that a medicinal foam of very high quality can thereby be obtained with a very good reproducibility. In addition, barriers, deflecting elements and the like may for example be provided within the mixing element to ensure the generation of sufficient turbulences.
[0022] The present device has the particular advantage that, due to the design of the connecting element, it is not necessary, for example after the production of a foam, to close a valve or the like, to avoid contamination of foam remaining in one of the syringes, for example. This is not necessary since an automatic closure is performed by the closure element when the syringe is removed from the connecting element. In particular for a later removal of the foam remaining in the syringe, a simple and safe reconnection of the syringe used for injection and the connecting element can be made. The handling of the present device is thus very simple while ensuring great safety.
[0023] Further, the invention refers to a vessel, such as a syringe, particularly useful in the present device. The vessel, preferably filled with gas, is connected to a connecting element comprising a closure element. The connecting element, particularly adapted to be connected with a second vessel, especially a second syringe, is preferably embodied as described above.
[0024] The invention further refers to a kit for producing medicinal foam comprising the above described first vessel, in particular filled with gas and closed with the connecting element. Moreover, the kit comprises a second vessel which, as the first vessel, is a syringe, in particular. In addition, the kit may comprise an active agent vessel, such as an active agent ampoule containing a sclerosing agent, for example. To produce the medicinal foam, the active agent is filled from the active agent vessel into the second vessel. Preferably, this is done by suction into the second vessel configured as a syringe. Possible, the kit my additionally comprise a needle for that purpose.
[0025] In an alternative embodiment of the kit, the second vessel, in particular the second syringe, instead of the active agent vessel is already filled with an active agent and closed with a closure means as described above.
[0026] In a particularly preferred embodiment of the kit the two vessels, which are conventional syringes in particular, are prefilled and connected with each other through the connecting element. However, the connection is such that the closure element of the connecting element is not yet open. This may be achieved, for example, by the fact that the second vessel, especially the second syringe, is not yet fully screwed to the connecting element using the Luer lock. The connection between the two vessels is then established by fully screwing or connecting the second vessel with the connecting element.
[0027] Such a kit has the particular advantage that the medicinal foam can be produced very quickly. Not tome consuming preparatory steps are required. This may increase acceptance with practitioners. Further, the risk of contamination while connecting individual components is avoided.
BRIEF DESCRIPTION OF THE DRAWINGS
[0028] A full and enabling disclosure of the present invention, including the best mode thereof, to one of ordinary skill in the art, is set forth more particularly in the remainder of the specification, including reference to the accompanying drawings in which
[0029] In the figures:
[0030] FIG. 1 is a schematic sectional side view of the connecting element,
[0031] FIG. 2 is a schematic sectional side view of the connecting element connected with two vessels,
[0032] FIG. 3 is a schematic sectional partial view of the connecting element together with the closure element of another embodiment,
[0033] FIG. 4 a schematic top plan view of the embodiment illustrated in FIG. 3 , and
[0034] FIGS. 5-7 schematic sectional partial views of the connecting element together with the closure element of other embodiments.
DESCRIPTION OF PREFERRED EMBODIMENTS
[0035] A connecting element 10 comprises a cylindrical hub 12 with an inner thread 14 . A channel 18 is formed within the hub 12 by a tube element 16 , especially of circular cross section. A tube 20 is arranged in the channel 18 , extending over almost the entire length of the connecting element. At one end face 22 , the tube element 16 has an opening 24 opening into the channel 18 .
[0036] A housing element 26 is connected with the hub 12 . The connection may be obtained along a contact surface 28 by glueing. Similarly, the two parts may be screwed together or connected otherwise. A circular cylindrical cavity 35 is formed in the housing 26 . A coil spring 32 is arranged in the cavity 30 , which urges a closure element 34 , also provided in the cavity 30 , outward against a stop 36 which, in the embodiment illustrated, is a chamfer. The closure element 34 , which comprises a membrane 42 and a sleeve in the embodiment illustrated, is a resiliently deformable element which can be pushed into the housing element of FIG. 1 from the right in a compressed condition, restores to its original shape within the housing 26 and is then held in the housing 26 because of the stop 36 . Similarly, it is possible to design the housing 26 as two parts to facilitate the mounting of the closure element 34 . in this instance, the housing 26 can be separated such that the closure element 34 is possible from the left in FIG. 7 .
[0037] The closure element, as well as the housing 26 and the hub 12 , is rotational symmetric to a center line 38 of the closure element 10 . The front side 10 of the closure element 34 is closed by a membrane 42 . The membrane 42 has a slit 44 . The slit 44 is illustrated in the drawing for the sakes of clarification. Actually, the membrane portions abut each other in the state illustrated in FIG. 1 so that the slit 44 is closed, yet may be opened easily ( FIG. 2 ).
[0038] The connecting element 10 may be connected with a gas vessel 46 and an active agent vessel 48 , the two vessels 46 , 48 preferably being conventional syringes with Luer lock connections 50 or 52 , respectively. For transport and prior to mixing the gas in the gas vessel 46 with the active agent present in the active agent vessel 48 , only the gas vessel 46 is connected to the connecting element. To do this, the Luer lock connector 50 of the gas vessel 46 is screwed into the hub 12 . Because of the opening 24 , a fluidic connection exists between the inner space 54 of the gas vessel 46 and the channel 18 in which the tube 20 is arranged.
[0039] Prior to inserting or screwing the liquid vessel 48 or the Luer lock 52 , respectively, the vessel 46 is closed tightly due to the closure element 34 .
[0040] By screwing or inserting the Luer lock 52 into the housing 26 , the closure element 34 is pushed into the connecting element 10 in the direction of the arrow 56 . Here, the slit 44 of the membrane 42 is opened or the membrane 42 is penetrated. Because of the opening 58 provided in the tube, the inner space 60 of the active agent vessel 48 is also fluidically connected with the channel 18 .
[0041] By actuating the syringe pistons or a feed means, the active agent may be pumped from the inner space 60 through the tube 20 or the channel 18 into the inner space 54 , and the gas may be pumped from the inner space 54 through the tube 20 into the inner space 60 . This causes an intermixing of the gas and the active agent and then the gas and the active agent are pumped back and forth together between the two spaces 54 , 60 . Thus, the medicinal foam is produced. This has the advantage that the force exerted for example on the syringe piston, as well as the pump rate can be adjusted or are defined. Thereby, the standardization of the foam produced is further enhanced.
[0042] The tube 20 serves as the mixing element and may possibly comprise additional deflecting or mixing elements inside. Further, deflecting or mixing elements can also or additionally be arranged at the inlet and/or the outlet of the tube 20 . Possibly, in addition to or instead of the above described mixing elements, mixing elements may also be provided in other regions of the devices through which the active agent and the gas flow. Moreover, the length off the pipe 20 is selected feasibly, in particular empirically. According to the invention, the change in cross section caused by the opening 24 and the opening 58 is sufficient for intermixing.
[0043] FIGS. 3 to 7 illustrate further embodiments of the present connecting element with different closure elements. In FIGS. 3-7 , identical or similar components are given the same reference numerals.
[0044] In the embodiment shown in FIGS. 3 and 4 , a plastics or rubber stopper 62 is provided as a closure element in the housing 26 . The plastics stopper 62 may be mounted as described above with reference to the closure element 34 . the plastics stopper 62 has a slit 64 which is spread apart when the plastics stopper 62 is moved in the direction of the arrow 66 . When the plastics stopper 62 is pushed back into the position shown in FIG. 3 by the spring 32 , the slit 64 is closed again automatically.
[0045] In the embodiment illustrated in FIG. 5 , the plastics stopper 62 additionally comprises a recess 68 directed towards the tube 20 , so that the tube 20 is positively guided and a secure opening of the slit is guaranteed.
[0046] In the embodiments shown in FIGS. 6 and 7 , the plastics stopper 62 is not opened with the aid of the tube 20 , but with a needle 70 or 72 , respectively. In this case, the needle 70 is either open in the direction of the stopper or the needle 72 has a lateral opening 74 . By providing the lateral opening 74 turbulences are created which, depending on the active agent used, allow for an enhanced production of foam. When needles 70 , 72 are provided, the slits 64 may be omitted.
[0047] Although the invention has been described and explained with reference to specific illustrative embodiments thereof, it is not intended that the invention be limited to those illustrative embodiments. Those skilled in the art will recognize that variations and modifications can be made without departing from the true scope of the invention as defined by the claims that follow. It is therefore intended to include within the invention all such variations and modifications as fall within the scope of the appended claims and equivalents thereof. | A device for producing medicinal foam comprises a gas vessel for holding a sterile gas and an active agent vessel for holding an active agent. A connecting element connects both vessels. Further, a feeder for feeding the gas and the active agent back and forth between the two vessels is provided for producing the medicinal foam. The connecting element comprises a closure element for a sterile closure of one of the two vessels. | 0 |
FIELD OF THE INVENTION
[0001] The present invention relates to a method and an apparatus for the use of carbon-isotope monoxide in labeling synthesis. More specifically, the invention relates to a method and apparatus for producing an [ 11 C]carbon monoxide enriched gas mixture from an initial [ 11 C]carbon dioxide gas mixture, and using the produced gas mixture in labeling synthesis by photo-initiated carbonylation. Radiolabeled esters are provided using alkyl or aryl iodides and alcohols as precursors.
BACKGROUND OF THE INVENTION
[0002] Tracers labeled with short-lived positron emitting radionuclides (e.g. 11 C, t 1/2 =20.3 min) are frequently used in various non-invasive in vivo studies in combination with positron emission tomography (PET). Because of the radioactivity, the short half-lives and the submicromolar amounts of the labeled substances, extraordinary synthetic procedures are required for the production of these tracers. An important part of the elaboration of these procedures is development and handling of new 11 C-labelled precursors. This is important not only for labeling new types of compounds, but also for increasing the possibility of labeling a given compound in different positions.
[0003] During the last two decades carbonylation chemistry using carbon monoxide has developed significantly. The recent development of methods such as palladium-catalyzed carbonylative coupling reactions has provided a mild and efficient tool for the transformation of carbon monoxide into different carbonyl compounds.
[0004] Carbonylation reactions using [ 11 C]carbon monoxide has a primary value for PET-tracer synthesis since biologically active substances often contain carbonyl groups or functionalities that can be derived from a carbonyl group. The syntheses are tolerant to most functional groups, which means that complex building blocks can be assembled in the carbonylation step to yield the target compound. This is particularly valuable in PET-tracer synthesis where the unlabelled substrates should be combined with the labeled precursor as late as possible in the reaction sequence, in order to decrease synthesis-time and thus optimize the uncorrected radiochemical yield.
[0005] When compounds are labeled with 11 C, it is usually important to maximize specific radioactivity. In order to achieve this, the isotopic dilution and the synthesis time must be minimized. Isotopic dilution from atmospheric carbon dioxide may be substantial when [ 11 C]carbon dioxide is used in a labeling reaction. Due to the low reactivity and atmospheric concentration of carbon monoxide (0.1 ppm vs. 3.4×10 4 ppm for CO 2 ), this problem is reduced with reactions using [ 11 C]carbon monoxide.
[0006] The synthesis of [ 11 C]carbon monoxide from [ 11 C]carbon dioxide using a heated column containing reducing agents such as zinc, charcoal or molybdenum has been described previously in several publications. Although [ 11 C]carbon monoxide was one of the first 11 C-labelled compounds to be applied in tracer experiments in human, it has until recently not found any practical use in the production of PET-tracers. One reason for this is the low solubility and relative slow reaction rate of [ 11 C]carbon monoxide which causes low trapping efficiency in reaction media. The general procedure using precursors such as [ 11 C]methyl iodide, [ 11 C]hydrogen cyanide or [ 11 C]carbon dioxide is to transfer the radioactivity in a gas-phase, and trap the radioactivity by leading the gas stream through a reaction medium. Until recently this has been the only accessible procedure to handle [ 11 C]carbon monoxide in labeling synthesis. With this approach, the main part of the labeling syntheses with [ 11 C]carbon monoxide can be expected to give a very low yield or fail completely.
[0007] There are only a few examples of practically valuable 11 C-labelling syntheses using high pressure techniques (>300 bar). In principal, high pressures can be utilized for increasing reaction rates and minimizing the amounts of reagents. One problem with this approach is how to confine the labeled precursor in a small high-pressure reactor. Another problem is the construction of the reactor. If a common column type of reactor is used (i.e. a cylinder with tubing attached to each end), the gas-phase will actually become efficiently excluded from the liquid phase at pressurization. The reason is that the gas-phase, in contracted form, will escape into the attached tubing and away from the bulk amount of the liquid reagent.
[0008] The cold-trap technique is widely used in the handling of 11 C-labelled precursors, particularly in the case of [ 11 C]carbon dioxide. The procedure has, however, only been performed in one single step and the labeled compound was always released in a continuous gas-stream simultaneous with the heating of the cold-trap. Furthermore, the volume of the material used to trap the labeled compound has been relative large in relation to the system to which the labeled compound has been transferred. Thus, the option of using this technique for radical concentration of the labeled compound and miniaturization of synthesis systems has not been explored. This is especially noteworthy in view of the fact that the amount of a 11 C-labelled compound usually is in the range 20-60 nmol.
[0009] Recent technical development for the production and use of [ 11 C]carbon monoxide has made this compound useful in labeling synthesis. WO 02/102711 describes a system and a method for the production and use of a carbon-isotope monoxide enriched gas-mixture from an initial carbon-isotope dioxide gas mixture. [ 11 C]carbon monoxide may be obtained in high radiochemical yield from cyclotron produced [ 11 C]carbon dioxide and can be used to yield target compounds with high specific radioactivity. This reactor overcomes the difficulties listed above and is useful in synthesis of 11 C-labelled compounds using [ 11 C] carbon monoxide in palladium or selenium mediated reaction. With such method, a broad array of carbonyl compounds can be labeled (Kilhlberg, T.; Langstrom, B. J., Org. Chem. 1999, 9201-9205). The use of transition metal mediated reactions is, however, restricted by problems related to the competing β-hydride elimination reaction, which excludes or at least severely restricts utilization of organic electrophiles having hydrogen in β-position. Thus, a limitation of the transition metal mediated reactions is that most alkyl halides could not be used as substrates due to the β-hydride elimination reaction. One way to circumvent this problem is to use free-radical chemistry based on light irradiation of alkyl halides. We earlier succeeded in using free-radical chemistry for the carbonylation of alkyl iodides using amines to yield labeled amides. However, the attempt to yield labeled esters in an analogous way (using alcohols as a reactant instead of amines) is challenged by the low reactivity of alcohols in these reaction conditions (typically the yields of esters compared to those of amides are lower by 10 to 100 times). Therefore, there is a need for a method in order to use photo-induced free radical carbonylation with weakly reacting alcohols to circumvent the problem with β-hydride elimination to complement the palladium mediated reactions and provide target structures with high yield to further increase the utility of [ 11 C]carbon monoxide in preparing useful PET tracers.
[0010] Discussion or citation of a reference herein shall not be construed as an admission that such reference is prior art to the present invention.
SUMMARY OF THE INVENTION
[0011] The present invention provides a method for labeling synthesis, comprising:
[0012] (a) providing a UV reactor assembly comprising a high pressure reaction chamber, a UV spot light source with a light guide, wherein the light guide is used to provide photo irradiation of a reaction mixture through a window in the reaction chamber,
[0013] (b) dissolving or reacting a base with an alcohol or a solution of alcohol in another solvent,
[0014] (c) adding an alkyl or aryl iodides to the solution of step (b) to give a reagent volume to be labeled,
[0015] (d) introducing a carbon-isotope monoxide enriched gas-mixture into the reaction chamber of the UV reactor assembly via the gas inlet,
[0016] (e) introducing at high-pressure said reagent volume into the reaction chamber via the liquid inlet,
[0017] (f) turning on the UV spot light source and waiting a predetermined time while the labeling synthesis occur, and
[0018] (g) collecting labeled ester from the reaction chamber.
[0019] The present invention also provides a system for labeling synthesis, comprising: a UV reactor assembly comprising a high pressure reaction chamber, a UV spot light source with a light guide, wherein a light guide is used to provide photo irradiation of the reaction mixture through a window in the reaction chamber thereof, wherein the photo irradiation from the light source, which stands at the distance from the reaction chamber, is delivered through the window of the reaction chamber.
[0020] The present invention further provides a method for the synthesis of labeled esters using photo-initiated carbonylation with [ 11 C]carbon monoxide using alcohols pretreated with a base and alkyl or aryl iodides.
[0021] In yet another embodiment, the invention also provides [ 11 C]-labeled esters. In still another embodiment, the invention provides kits for use as PET tracers comprising [ 11 C]-labeled esters.
BRIEF DESCRIPTION OF THE FIGURES
[0022] FIG. 1 shows a flow chart over the method according to the invention
[0023] FIG. 2 is a schematic view of a carbon-isotope monoxide production and labeling-system according to the invention.
[0024] FIG. 3 is the cross-sectional view of the reaction chamber.
[0025] FIG. 4 is a view of the UV spot light source.
[0026] FIG. 5 shows how the reaction chamber, magnetic stirrer, and the UV spot light source are arranged into the UV reactor assembly.
[0027] FIGS. 6 a and 6 b show alternative embodiments of a reaction chamber according to the invention.
DETAILED DESCRIPTION OF THE INVENTION
[0028] The object of the invention is to provide a method and a system for production of and use of carbon-isotope monoxide in labeling synthesis that overcomes the drawbacks of the prior art devices. This is achieved by the method and system claimed in the invention.
[0029] One advantage with such a method and system is that nearly quantitative conversion of carbon-isotope monoxide into labeled products can be accomplished.
[0030] There are several other advantages with the present method and system. The high-pressure technique makes it possible to use low boiling solvents such as diethyl ether at high temperatures (e.g. 200° C.). The use of a closed system consisting of materials that prevents gas diffusion, increases the stability of sensitive compounds and could be advantageous also with respect to Good Manufacturing Practice (GMP).
[0031] Still other advantages are achieved in that the resulting labeled compound is highly concentrated, and that the miniaturization of the synthesis system facilitates automation, rapid synthesis and purification, and optimization of specific radioactivity through minimization of isotopic dilution.
[0032] Most important is the opening of completely new synthesis possibilities, as exemplified by the present invention.
[0033] Embodiments of the invention will now be described with reference to the figures.
[0034] The term carbon-isotope that is used throughout this application preferably refers to 11 C, but it should be understood that 11 C may be substituted by other carbon-isotopes, such as 13 C and 14 C, if desired.
[0035] FIG. 1 shows a flow chart over the method according to the invention, which firstly comprises production of a carbon-isotope monoxide enriched gas-mixture and secondly a labeling synthesis procedure. More in detail the production part of the method comprises the steps of:
Providing carbon-isotope dioxide in a suitable carrier gas of a type that will be described in detail below. Converting carbon-isotope dioxide to carbon-isotope monoxide by introducing said gas mixture in a reactor device which will be described in detail below. Removing traces of carbon-isotope dioxide by flooding the converted gas-mixture through a carbon dioxide removal device wherein carbon-isotope dioxide is trapped but not carbon-isotope monoxide nor the carrier gas. The carbon dioxide removal device will be described in detail below. Trapping carbon-isotope monoxide in a carbon monoxide trapping device, wherein carbon-isotope monoxide is trapped but not said carrier gas. The carbon monoxide trapping device will be described in detail below. Releasing said trapped carbon-isotope monoxide from said trapping device, whereby a volume of carbon-isotope monoxide enriched gas-mixture is achieved.
[0041] The production step may further comprise a step of changing carrier gas for the initial carbon-isotope dioxide gas mixture if the initial carbon-isotope dioxide gas mixture is comprised of carbon-isotope dioxide and a first carrier gas not suitable as carrier gas for carbon monoxide due to similar molecular properties or the like, such as nitrogen. More in detail the step of providing carbon-isotope dioxide in a suitable second carrier gas such as He, Ar, comprises the steps of:
Flooding the initial carbon-isotope dioxide gas mixture through a carbon dioxide trapping device, wherein carbon-isotope dioxide is trapped but not said first carrier gas. The carbon dioxide trapping device will be described in detail below. Flushing said carbon dioxide trapping device with said suitable second carrier gas to remove the remainders of said first carrier gas. Releasing said trapped carbon-isotope dioxide in said suitable second carrier gas.
[0045] The labeling synthesis step that may follow the production step utilizes the produced carbon-isotope dioxide enriched gas-mixture as labeling reactant. More in detail the step of labeling synthesis comprises the steps of:
Providing a UV reactor assembly comprising a UV spot light source and a high pressure reaction chamber having a liquid reagent inlet and a labeling reactant inlet in a bottom surface thereof. In a preferred embodiment, the UV reactor assembly further comprises a magnetic stirrer and a magnetic stirring bar. In another preferred embodiment, the UV reactor assembly further comprises a protective housing and a bench where the reaction chamber, UV spot light guide and the magnetic stirrer can be mounted. The UV reactor assembly and the reaction chamber will be described in detail below. Providing a reagent volume that is to be labeled. The reagent volume can be prepared in following steps: 1. Dissolve or react a base with an alcohol or a solution of an alcohol in another solvent; 2. Add alkyl or aryl iodide to the solution of step 1 to form a reagent volume as late as possible before being introduced into the high pressure reaction chamber. Definition and examples of base will be provided below. Introducing the carbon-isotope monoxide enriched gas-mixture into the reaction chamber via the labeling reactant inlet. Introducing, at high pressure, said liquid reagent into the reaction chamber via the liquid reagent inlet. Turning on the UV spot light source and waiting a predetermined time while the labeling synthesis occurs. Collecting the solution of labeled ester from the reaction chamber.
[0052] The step of waiting a predetermined time may further comprise adjusting the temperature of the reaction chamber such that the labeling synthesis is enhanced.
[0053] FIG. 2 schematically shows a [ 11 C]carbon dioxide production and labeling-system according to the present invention. The system is comprised of three main blocks, each handling one of the three main steps of the method of production and labeling:
Block A is used to perform a change of carrier gas for an initial carbon-isotope dioxide gas mixture, if the initial carbon-isotope dioxide gas mixture is comprised of carbon-isotope dioxide and a first carrier gas not suitable as carrier gas for carbon monoxide. Block B is used to perform the conversion from carbon-isotope dioxide to carbon-isotope monoxide, and purify and concentrate the converted carbon-isotope monoxide gas mixture. Block C is used to perform the carbon-isotope monoxide labeling synthesis.
[0057] Block A is normally needed due to the fact that carbon-isotope dioxide usually is produced using the 14N(p,α) 11 C reaction in a target gas containing nitrogen and 0.1% oxygen, bombarded with 17 MeV protons, whereby the initial carbon-isotope dioxide gas mixture comprises nitrogen as carrier gas. However, compared with carbon monoxide, nitrogen show certain similarities in molecular properties that makes it difficult to separate them from each other, e.g. in a trapping device or the like, whereby it is difficult to increase the concentration of carbon-isotope monoxide in such a gas mixture. Suitable carrier gases may instead be helium, argon or the like. Block A can also used to change the pressure of the carrier gas (e.g. from 1 to 4 bar), in case the external system does not tolerate the gas pressure needed in block B and C. In an alternative embodiment the initial carbon-isotope dioxide gas mixture is comprised of carbon-isotope dioxide and a first carrier gas that is well suited as carrier gas for carbon monoxide, whereby the block A may be simplified or even excluded.
[0058] According to a preferred embodiment ( FIG. 2 ), block A is comprised of a first valve V 1 , a carbon dioxide trapping device 8 , and a second valve V 2 .
[0059] The first valve V 1 has a carbon dioxide inlet 10 connected to a source of initial carbon-isotope dioxide gas mixture 12 , a carrier gas inlet 14 connected to a source of suitable carrier gas 16 , such as helium, argon and the like. The first valve V 1 further has a first outlet 18 connected to a first inlet 20 of the second valve V 2 , and a second outlet 22 connected to the carbon dioxide trapping device 8 . The valve V 1 may be operated in two modes A, B, in mode A the carbon dioxide inlet 10 is connected to the first outlet 18 and the carrier gas inlet 14 is connected to the second outlet 22 , and in mode B the carbon dioxide inlet 10 is connected to the second outlet 22 and the carrier gas inlet 14 is connected to the first outlet 18 .
[0060] In addition to the first inlet 20 , the second valve V 2 has a second inlet 24 connected to the carbon dioxide trapping device 8 . The second valve V 2 further has a waste outlet 26 , and a product outlet 28 connected to a product inlet 30 of block B. The valve V 2 may be operated in two modes A, B, in mode A the first inlet 20 is connected to the waste outlet 26 and the second inlet 24 is connected to the product outlet 28 , and in mode B the first inlet 20 is connected to the product outlet 28 and the second inlet 24 is connected to the waste outlet 26 .
[0061] The carbon dioxide trapping device 8 is a device wherein carbon dioxide is trapped but not said first carrier gas, which trapped carbon dioxide thereafter may be released in a controlled manner. This may preferably be achieved by using a cold trap, such as a column containing a material which in a cold state, (e.g. −196° C. as in liquid nitrogen or −186° C. as in liquid argon) selectively trap carbon dioxide and in a warm state (e.g. +50° C.) releases the trapped carbon dioxide. (In this text the expression “cold trap” is not restricted to the use of cryogenics. Thus, materials that trap the topical compound at room temperature and release it at a higher temperature are included). One suitable material is porapac Q®. The trapping behavior of a porapac-column is related to dipole-dipole interactions or possibly Van der Waal interaktions. The said column 8 is preferably formed such that the volume of the trapping material is to be large enough to efficiently trap (>95%) the carbon-isotope dioxide, and small enough not to prolong the transfer of trapped carbon dioxide to block B. In the case of porapac Q® and a flow of 100 ml nitrogen/min, the volume should be 50-150 μl. The cooling and heating of the carbon dioxide trapping device 8 may further be arranged such that it is performed as an automated process, e.g. by automatically lowering the column into liquid nitrogen and moving it from there into a heating arrangement.
[0062] According to the preferred embodiment of FIG. 2 block B is comprised of a reactor device 32 in which carbon-isotope dioxide is converted to carbon-isotope monoxide, a carbon dioxide removal device 34 , a check-valve 36 , and a carbon monoxide trapping device 38 , which all are connected in a line.
[0063] In the preferred embodiment the reactor device 32 is a reactor furnace comprising a material that when heated to the right temperature interval converts carbon-isotope dioxide to carbon-isotope monoxide. A broad range of different materials with the ability to convert carbon dioxide into carbon monoxide may be used, e.g. zinc or molybdenum or any other element or compound with similar reductive properties. If the reactor device 32 is a zinc furnace it should be heated to 400° C., and it is important that the temperature is regulated with high precision. The melting point of zinc is 420° C. and the zinc-furnace quickly loses it ability to transform carbon dioxide into carbon monoxide when the temperature reaches over 410° C., probably due to changed surface properties. The material should be efficient in relation to its amount to ensure that a small amount can be used, which will minimize the time needed to transfer radioactivity from the carbon dioxide trapping device 8 to the subsequent carbon monoxide trapping device 38 . The amount of material in the furnace should be large enough to ensure a practical life-time for the furnace (at least several days). In the case of zinc granulates, the volume should be 100-1000 μl.
[0064] The carbon dioxide removal device 34 is used to remove traces of carbon-isotope dioxide from the gas mixture exiting the reactor device 32 . In the carbon dioxide removal device 34 , carbon-isotope dioxide is trapped but not carbon-isotope monoxide nor the carrier gas. The carbon dioxide removal device 34 may be comprised of a column containing Ascarite® (i.e. sodium hydroxide on silica). Carbon-isotope dioxide that has not reacted in the reactor device 32 is trapped in this column (it reacts with sodium hydroxide and turns into sodium carbonate), while carbon-isotope monoxide passes through. The radioactivity in the carbon dioxide removal device 34 is monitored as a high value indicates that the reactor device 32 is not functioning properly.
[0065] Like the carbon dioxide trapping device 8 , the carbon monoxide trapping device 38 , has a trapping and a releasing state. In the trapping state carbon-isotope monoxide is selectively trapped but not said carrier gas, and in the releasing state said trapped carbon-isotope monoxide is released in a controlled manner. This may preferably be achieved by using a cold trap, such as a column containing silica which selectively trap carbon monoxide in a cold state below −100° C., e.g. −196° C. as in liquid nitrogen or −186° C. as in liquid argon, and releases the trapped carbon monoxide in a warm state (e.g. +50° C.). Like the porapac-column, the trapping behavior of the silica-column is related to dipole-dipole interactions or possibly Van der Waal interactions. The ability of the silica-column to trap carbon-isotope monoxide is reduced if the helium, carrying the radioactivity, contains nitrogen. A rationale is that since the physical properties of nitrogen are similar to carbon monoxide, nitrogen competes with carbon monoxide for the trapping sites on the silica.
[0066] According to the preferred embodiment of FIG. 2 , block C is comprised of a first and a second reaction chamber valve V 3 and V 4 , a reagent valve V 5 , an injection loop 70 and a solvent valve V 6 , and the UV reactor assembly 51 which comprises a UV lamp 91 , a concave minor 92 and a reaction chamber 50 .
[0067] The first reaction chamber valve V 3 has a gas mixture inlet 40 connected to the carbon monoxide trapping device 38 , a stop position 42 , a collection outlet 44 , a waste outlet 46 , and a reaction chamber connection port 48 connected to a gas inlet 52 of the reaction chamber 50 . The first reaction chamber valve V 3 has four modes of operation A to D. The reaction chamber connection port 48 is: in mode A connected to the gas mixture inlet 40 , in mode B connected to the stop position 42 , in mode C connected to the collection outlet 44 , and in mode D connected to the waste outlet 46 .
[0068] FIG. 3 shows the reaction chamber 50 (micro-autoclave) which has a gas inlet 52 and a liquid inlet 54 , which are arranged such that they terminate at the bottom surface of the chamber. Gas inlet 52 may also be used as product outlet after the labeling is finished. During operation the carbon-isotope monoxide enriched gas mixture is introduced into the reaction chamber 50 through the gas inlet 52 , where after the liquid reagent at high pressure enters the reaction chamber 50 through the liquid inlet 54 . FIGS. 6 a and 6 b shows schematic views of two preferred reaction chambers 50 in cross section. FIG. 6 a is a cylindrical chamber which is fairly easy to produce, whereas the spherical chamber of FIG. 6 b is the most preferred embodiment, as the surface area to volume-ratio of the chamber is further minimized. A minimal surface area to volume-ratio optimizes the recovery of labeled product and minimizes possible reactions with the surface material. Due to the “diving-bell construction” of the reaction chamber 50 , both the gas inlet 52 and the liquid inlet 54 becomes liquid-filled and the reaction chamber 50 is filled from the bottom upwards. The gas-volume containing the carbon-isotope monoxide is thus trapped and given efficient contact with the reaction mixture. Since the final pressure of the liquid is approximately 80 times higher than the original gas pressure, the final gas volume will be less than 2% of the liquid volume according to the general gas-law. Thus, a pseudo one-phase system will result. In the instant application, the term “pseudo one-phase system” means a closed volume with a small surface area to volume-ratio containing >96% liquid and <4% gas at pressures exceeding 200 bar. In most syntheses the transfer of carbon monoxide from the gas-phase to the liquid phase will probably not be the rate limiting step. After the labeling is finished the labeled volume is nearly quantitatively transferred from the reaction chamber by the internal pressure via the gas inlet/product outlet 52 and the first reaction chamber valve V 3 in position C.
[0069] In a specific embodiment, FIG. 3 shows a reaction chamber made from stainless steel (Valco™) column end fitting 101 . It is equipped with sapphire window 102 , which is a hard material transparent to short wavelength UV radiation. The window is pressed between two Teflon washers 103 inside the drilled column end fitting to make the reactor tight at high pressures. Temperature measurement can be accomplished with the thermocouple 104 attached by solder drop 105 to the outer side of the reactor. A magnet stirrer (not shown) drives small Teflon coated magnet stirring bar 106 placed inside the reaction chamber. The magnetic stirrer can be attached against the bottom of the reaction chamber. Distance between the magnet stirrer and the reactor should be minimal.
[0070] FIG. 4 shows a commercial UV spot light source 110 (for example, Hamamatsu Lightningcure™ LC5), which is an example of UV spot light sources that can be used in the instant invention. Light source 110 has necessary means of operating and controlling the photo irradiation that is produced, of the light source is available from the manufacturer (Hamamatsu Photonics K.K.). Thus intensity and time duration of the photo irradiation are easily adjusted by an operator. Light source 110 may be externally controlled by a computer, providing a possibility for automating the reactor assembly. The photo irradiation is delivered to the reaction vessel through a flexible light guide, which is an accessory of Hamamatsu Lightningcure™ LC5. Thus light source 110 may be placed at the distance from the reaction chamber providing the possibility to save precious space inside a sheltered hot-cell, where the radiolabeling syntheses are carried out. Light source 110 complies with the existing industrial safety standards. Further, optional accessories (e.g. changeable lamps, optical filters) are provided which may be advantageously used for adjusting the properties of the photo irradiation.
[0071] FIG. 5 shows the reaction chamber 50 situated a magnetic stirrer 201 , with gas inlet/product outlet 52 and liquid inlet 54 facing the magnetic stirrer 201 . Top of the reaction chamber 50 is connected through the flexible light guide 202 to the UV spot light source (not shown).
[0072] Referring back to FIG. 2 , the second reaction chamber valve V 4 has a reaction chamber connection port 56 , a waste outlet 58 , and a reagent inlet 60 . The second reaction chamber valve V 4 has two modes of operation A and B. The reaction chamber connection port 56 is: in mode A connected to the waste outlet 58 , and in mode B it is connected to the reagent inlet 60 .
[0073] The reagent valve V 5 , has a reagent outlet 62 connected to the reagent inlet 60 of the second reaction chamber valve V 4 , an injection loop inlet 64 and outlet 66 between which the injection loop 70 is connected, a waste outlet 68 , a reagent inlet 71 connected to a reagent source, and a solvent inlet 72 . The reagent valve V 5 , has two modes of operation A and B. In mode A the reagent inlet 71 is connected to the injection loop inlet 64 , and the injection loop outlet 66 is connected to the waste outlet 68 , whereby a reagent may be fed into the injection loop 70 . In mode B the solvent inlet 72 is connected to the injection loop inlet 64 , and the injection loop outlet 66 is connected to the reagent outlet 62 , whereby reagent stored in the injection loop 70 may be forced via the second reaction chamber valve V 4 into the reaction chamber 50 if a high pressure is applied on the solvent inlet 72 .
[0074] The solvent valve V 6 , has a solvent outlet 74 connected to the solvent inlet 72 of the reagent valve V 5 , a stop position 76 , a waste outlet 78 , and a solvent inlet 80 connected to a solvent supplying HPLC-pump (High Performance Liquid Chromatography) or any liquid-pump capable of pumping organic solvents at 0-10 ml/min at pressures up to 400 bar (not shown). The solvent valve V 6 , has two modes of operation A and B. In mode A the solvent outlet 74 is connected to the stop position 76 , and the solvent inlet 80 is connected to the waste outlet 78 . In mode B the solvent outlet 74 is connected to the solvent inlet 80 , whereby solvent may be pumped into the system at high pressure by the HPLC-pump.
[0075] Except for the small volume of silica in the carbon monoxide trapping devise 38 , an important difference in comparison to the carbon dioxide trapping device 8 , as well as to all related prior art, is the procedure used for releasing the carbon monoxide. After the trapping of carbon monoxide on carbon monoxide trapping devise 8 , valve V 3 is changed from position A to B to stop the flow from the carbon monoxide trapping devise 38 and increase the gas-pressure on the carbon monoxide trapping devise 38 to the set feeding gas pressure (3-5 bar). The carbon monoxide trapping devise 38 is then heated to release the carbon monoxide from the silica surface while not significantly expanding the volume of carbon monoxide in the carrier gas. Valve V 4 is changed from position A to B and valve V 3 is then changed from position B to A. At this instance the carbon monoxide is rapidly and almost quantitatively transferred in a well-defined micro-plug into the reaction chamber 50 . Micro-plug is defined as a gas volume less than 10% of the volume of the reaction chamber 50 , containing the topical substance (e.g. 1-20 μL). This unique method for efficient mass-transfer to a small reaction chamber 50 , having a closed outlet, has the following prerequisites:
A micro-column 38 defined as follows should be used. The volume of the trapping material (e.g. silica) should be large enough to efficiently trap (>95%) the carbon-isotope monoxide, and small enough (<1% of the volume of a subsequent reaction chamber 50 ) to allow maximal concentration of the carbon-isotope monoxide. In the case of silica and a reaction chamber 50 volume of 2004 the silica volume should be 0.1-2 μl. The dead volumes of the tubing and valve(s) connecting the silica column and the reaction chamber 50 should be minimal (<10% of the micro-autoclave volume). The pressure of the carrier gas should be 3-5 times higher than the pressure in the reaction chamber 50 before transfer (1 atm.).
[0079] In one specific preferred embodiment specifications, materials and components are chosen as follows. High pressure valves from Valco®, Reodyne® or Cheminert® are used. Stainless steel tubing with o.d. 1/16″ is used except for the connections to the porapac-column 8 , the silica-column 38 and the reaction chamber 50 where stainless steel tubing with o.d. 1/32″ are used in order to facilitate the translation movement. The connections between V 1 , V 2 and V 3 should have an inner diameter of 0.2-1 mm. The requirement is that the inner diameter should be large enough not to obstruct the possibility to achieve the optimal flow of He (2-50 ml/min) through the system, and small enough not to prolong the time needed to transfer the radioactivity from the porapac-column 8 to the silica-column 38 . The dead volume of the connection between V 3 and the autoclave should be minimized (<10% of the autoclave volume). The inner diameter (0.05-0.1 mm) of the connection must be large enough to allow optimal He flow (2-50 ml/min). The dead volume of the connection between V 4 and V 5 should be less than 10% of the autoclave volume.
[0080] The porapac-column 8 preferably is comprised of a stainless steel tube (o.d.=⅛″, i.d.=2 mm, 1=20 mm) filled with Porapac Q® and fitted with stainless steel screens. The silica-column 38 preferably is comprised of a stainless steel tube (o.d= 1/16″, i.d.=0.1 mm) with a cavity (d=1 mm, h=1 mm, V=0.8 μl) in the end. The cavity is filled with silica powder (100/80 mesh) of GC-stationary phase type. The end of the column is fitted against a stainless steel screen.
[0081] It should be noted that a broad range of different materials could be used in the trapping devices. If a GC-material is chosen, the criterions should be good retardation and good peak-shape for carbon dioxide and carbon monoxide respectively. The latter will ensure optimal recovery of the radioactivity.
[0082] Below a detailed description is given of a method of producing carbon-isotope using an exemplary system as described above.
[0083] Preparations of the system are performed by the steps 1 to 5:
1. V 1 in position A, V 2 in position A, V 3 in position A, V 4 in position A, helium flow on with a max pressure of 5 bar. With this setting, the helium flow goes through the porapac column, the zinc furnace, the silica column, the reaction chamber 50 and out through V 4 . The system is conditioned, the reaction chamber 50 is rid of solvent and it can be checked that helium can be flowed through the system with at least 10 ml/min. UV lamp 91 is turned on. 2. The zinc-furnace is turned on and set at 400° C. 3. The porapac and silica-columns are cooled with liquid nitrogen. At −196° C., the porapac and silica-column efficiently traps carbon-isotope dioxide and carbon-isotope monoxide respectively. 4. V 5 in position A (load). The injection loop (250 μl), attached to V 5 , is loaded with the reaction mixture. 5. The HPLC-pump is attached to a flask with freshly distilled THF (or other high quality solvent) and primed. V 6 in position A.
[0089] Production of carbon-isotope dioxide may be performed by the steps 6 to 7:
6. Carbon-isotope dioxide is produced using the 14N(p,α) 11 C reaction in a target gas containing nitrogen (AGA, Nitrogen 6.0) and 0.1% oxygen (AGA. Oxygen 4.8), bombarded with 17 MeV protons. 7. The carbon-isotope dioxide is transferred to the apparatus using nitrogen with a flow of 100 ml/min.
[0092] Synthesis of carbon-isotope may thereafter be performed by the steps 8 to 16
8. V 1 in position B and V 2 in position B. The nitrogen flow containing the carbon-isotope dioxide is now directed through the porapac-column (cooled to −196° C.) and out through a waste line. The radioactivity trapped in the porapac-column is monitored. 9. When the radioactivity has peaked, V 1 is changed to position A. Now a helium flow is directed through the porapac-column and out through the waste line. By this operation the tubings and the porapac-column are rid of nitrogen. 10. V 2 in position A and the porapac-column is warmed to about 50° C. The radioactivity is now released from the porapac-column and transferred with a helium flow of 10 ml/min into the zinc-furnace where it is transformed into carbon-isotope monoxide. 11. Before reaching the silica-column (cooled to −196° C.), the gas flow passes the ascarite-column. The carbon-isotope monoxide is now trapped on the silica-column. The radioactivity in the silica-column is monitored and when the value has peaked, V 3 is set to position B and then V 4 is set to position B. 12. The silica-column is heated to approximately 50° C., which releases the carbon-isotope monoxide. V 3 is set to position A and the carbon-isotope monoxide is transferred to the reaction chamber 50 within 15 s. 13. V 3 is set to position B, V 5 is set to position B, the HPLC-pump is turned on (flow 7 ml/min) and V 6 is set to position B. Using the pressurised THF (or other solvent), the reaction mixture is transferred to the reaction chamber 50 . When the HPLC-pump has reached its set pressure limit (e.g 40 Mpa), it is automatically turned off and then V 6 is set to position A. 14. UV spot light source 110 , magnetic stirrer 201 and magnet stirring bar 106 in reaction chamber 50 are turned on. 15. After a sufficient reaction-time (usually 5 min), V 3 is set to position C and the content of the reaction chamber 50 is transferred to a collection vial. 16. The reaction chamber 50 can be rinsed by the following procedure: V 3 is set to position B, the HPLC-pump is turned on, V 6 is set to position B and when maximal pressure is reached V 6 is set to position A and V 3 is set to position 3 thereby transferring the rinse volume to the collection vial.
[0102] With the recently developed fully automated version of the reaction chamber 50 system according to the invention, the value of [ 11 C]carbon monoxide as a precursor for 11 C-labelled tracers has become comparable with [ 11 C]methyl iodide. Currently, [ 11 C]methyl iodide is the most frequently used 11 C-precursor due to ease in production and handling and since groups suitable for labeling with [ 11 C]methyl iodide (e.g. hetero atom bound methyl groups) are common among biologically active substances. Carbonyl groups, which can be conveniently labeled with [ 11 C]carbon monoxide, are also common among biologically active substances. In many cases, due to metabolic events in vivo, a carbonyl group may even be more advantageous than a methyl group as labeling position. The use of [ 11 C]carbon monoxide for production of PET-tracers may thus become an interesting complement to [ 11 C]methyl iodide. Furthermore, through the use of similar technology, this method will most likely be applicable for synthesis of 13 C and 14 C substituted compounds.
[0103] The main advantage of the present invention is to overcome the limitations of transition metal-mediated reaction to synthesize 11 C-labeled esters using alkyl/aryl iodides and alcohols as precursors. The levels of specific radioactivity are high compared with alternative methods such as the use of Grignard reactions for preparation of [carbonyl- 11 C]esters. Iodides used in this invention have a formula RI, where R is linear or cyclic alkyl or substituted alkyl, aryl or substituted aryl, and may contain chloro, fluoro, ester and carboxyl groups, which are separated by at least one carbon atom from the carbon atom bearing the iodide atom. Alcohol used may be a primary, secondary or tertiary alcohol, or phenol. A base is defined as any organic or inorganic compound that produces RO − anion upon the reaction with alcohols (but does not produce any other products which may be reactive towards reagents, intermediates, and products that will hinder the desired radiolabelling transformation). Examples of base include alkali metal hydrides (for example, KH, NaH), hydroxides (for example, KOH), carbonates (for example, K 2 CO 3 , Cs 2 CO 3 ), alkali metal amides (for example, lithium hexamethyldisilylamide), alkyl or aryl metals (for example, butyl lithium, phenyl lithium). Alcohols are pretreated by such a base before mixing with RI. The term “pretreat” is meant such a base dissolves in or reacts with alcohols. Alternatively solutions of alkoxides, which in many cases are commercially available, may be used. The resultant labeled esters have a formula
[0000]
[0000] wherein R is defined as above. They provide valuable PET tracers in various PET studies. In an embodiment of the present invention, it provides kits for use as PET tracers comprising [ 11 C]-labeled esters.
[0104] Such kits are designed to give sterile products suitable for human administration, e.g. direct injection into the bloodstream. Suitable kits comprise containers (e.g. septum-sealed vials) containing the [ 11 C]-labeled esters.
[0105] The kits may optionally further comprise additional components such as radioprotectant, antimicrobial preservative, pH-adjusting agent or filler.
[0106] By the term “radioprotectant” is meant a compound which inhibits degradation reactions, such as redox processes, by trapping highly-reactive free radicals, such as oxygen-containing free radicals arising from the radiolysis of water. The radioprotectants of the present invention are suitably chosen from: ascorbic acid, para-aminobenzoic acid (i.e. 4-aminobenzoic acid), gentisic acid (i.e. 2,5-dihydroxybenzoic acid) and salts thereof.
[0107] By the term “antimicrobial preservative” is meant an agent which inhibits the growth of potentially harmful micro-organisms such as bacteria, yeasts or moulds. The antimicrobial preservative may also exhibit some bactericidal properties, depending on the dose. The main role of the antimicrobial preservative(s) of the present invention is to inhibit the growth of any such micro-organism in the pharmaceutical composition post-reconstitution, i.e. in the radioactive diagnostic product itself. The antimicrobial preservative may, however, also optionally be used to inhibit the growth of potentially harmful micro-organisms in one or more components of the kit of the present invention prior to reconstitution. Suitable antimicrobial preservatives include: the parabens, i.e., ethyl, propyl or butyl paraben or mixtures thereof; benzyl alcohol; phenol; cresol; cetrimide and thiomersal. Preferred antimicrobial preservative(s) are the parabens.
[0108] The term “pH-adjusting agent” means a compound or mixture of compounds useful to ensure that the pH of the reconstituted kit is within acceptable limits (approximately pH 4.0 to 10.5) for human administration. Suitable such pH-adjusting agents include pharmaceutically acceptable buffers, such as tricine, phosphate or TRIS [i.e. tris(hydroxymethyl)aminomethane], and pharmaceutically acceptable bases such as sodium carbonate, sodium bicarbonate or mixtures thereof. When the ligand conjugate is employed in acid salt form, the pH-adjusting agent may optionally be provided in a separate vial or container, so that the user of the kit can adjust the pH as part of a multi-step procedure.
[0109] By the term “filler” is meant a pharmaceutically acceptable bulking agent which may facilitate material handling during production and lyophilisation. Suitable fillers include inorganic salts such as sodium chloride, and water soluble sugars or sugar alcohols such as sucrose, maltose, mannitol or trehalose.
[0110] General reaction scheme for the synthesis of labeled esters are as illustrated below:
[0000]
[0000] wherein R is as defined above. *indicates the 11 C-labeled position. In alternative embodiments, an alcohol may be the reactant in the final step instead of an alkoxide.
EXAMPLES
[0111] The invention is further described in the following examples which are in no way intended to limit the scope of the invention.
Example 1
Precursors and Resultant Products
[0112] Precursors that were used to label esters are shown in List. 1.
[0000]
[0113] The following experiments illustrate the present invention. Radical carbonylation using submicromolar amounts of [ 11 C]carbon monoxide is performed yielding labeled with the esters shown in Table 1 as target compounds. Table 1 Radiochemical yields for 11 C-labelled esters
[0000]
TABLE 1
Radiochemical yields for 11 C-labelled esters
11 CO
Isolated
Additive
conv.
Purity
Yield b
Yield
n
Labelled compound a
Solvent
(mmol)
(%)
(%)
(%)
(%)
1
THF THF
LiHDMS (0.1) —
84 ± 1 19
97 ± 1 10
81 ± 3 2
67 ± 1 —
2
Me 2 CHOH
KOH (0.05)
87
86
75
3
MeOH Me 2 CO/MeOH (1:1)
— —
42 ± 1 86 ± 1
93 ± 2 85 ± 1
39 ± 2 72 ± 1
33 ± 1 56 ± 1
4
THF
BuLi (0.1)
80 ± 2
73 ± 2
58 ± 3
42 ± 3
5
THF/H 2 O (4:1) THF
KOH (0.1) BuLi (0.1)
99 69
56 82
55 57
38 49
6
THF/H 2 O (4:1) THF/CH 3 OH (5:2)
KOH (0.1) BuLi (0.1)
82 78
84 83
69 65
61 58
7
THF/CH 3 OH (5:1)
LiHDMS (0.02)
77 78
87 87
67 68
50 51
8
CH 3 OH
KOH (0.1)
84
74
62
57
0.05
9
THF/C 2 H 5 OH (4:1)
LiHDMS (0.05)
84 ± 1
93 ± 3
78 ± 2
53 ± 3
0.05
a The position of 11 C label is denoted by an asterisk.
b Decay-corrected radiochemical yield determined by LC.
c Number of runs.
d Unseparated peaks.
Example 2
Experimental Setup
[0114] [ 11 C]Carbon dioxide production was performed using a Scanditronix MC-17 cyclotron at Uppsala Imanet. The 14 N(p,α) 11 C reaction was employed in a gas target containing nitrogen (Nitrogen 6.0) and 0.1% oxygen (Oxygen 4.8), that was bombarded with 17 MeV protons.
[0115] [ 11 C]Carbon monoxide was obtained by reduction of [ 11 C]carbon dioxide as described previously (Kihlberg, T.; Långström, B. Method and apparatus for production and use of [ 11 C]carbon monoxide in labeling synthesis. Swedish Pending Patent Application No. 0102174-0).
[0116] Liquid chromatographic analysis (LC) was performed with a gradient pump and a variable wavelength UV-detector in series with a β+-flow detector. An automated synthesis apparatus, Synthia (Bjurling, P.; Reineck, R.; Westerberg, G.; Gee, A. D.; Sutcliffe, J.; Långström, B. In Proceedings of the VIth workshop on targetry and target chemistry ; TRIUMF: Vancouver, Canada, 1995; pp 282-284) was used for LC purification of the labelled products.
[0117] Radioactivity was measured in an ion chamber. Xenon-mercury lamp was used as a photo-irradiation source.
[0118] In the analysis of the 11 C-labeled compounds, isotopically unchanged reference substances were used for comparison in all the LC runs.
[0119] NMR spectra were recorded at 400 MHz for 1 H and at 100 MHz for 13 C, at 25° C. Chemical shifts were referenced to TMS via the solvent signals.
[0120] LC-MS analysis was performed with electrospray ionization.
[0121] Solvents: THF was distilled under nitrogen from sodium/benzophenone; all other solvents were commercial grade. The solvents were purged with helium.
[0122] Alkyl iodides were commercially available or otherwise prepared from commercial alkyl bromides by the Finkelstein reaction.
Example 3
Preparation of [Carbonyl- 11 C] Esters
[0123] General procedure: An alcohol (200 μmol) and appropriate base (Table 1) was placed in a capped vial (1 mL, flushed beforehand with nitrogen to remove air) and dissolved in THF (500 μL); in some cases the alcohol was used as a solvent instead of THF. An iodide (100 μmol) was added to the solution ca. 7 min before the start of the synthesis. The resulting mixture was pressurized (over 40 MPa) into the autoclave, pre-charged with [ 11 C]carbon monoxide (10 −8 -10 −9 mol) and helium gas mixture. The mixture was irradiated with the Xe—Hg lamp for 6 min with stirring at 35° C. The crude reaction mixture was then transferred from the autoclave to a capped vial, held under reduced pressure. After measurement of the radioactivity the vial was purged with nitrogen and the radioactivity was measured again. The crude product was diluted with acetonitrile or methanol (0.6 mL) and injected on the semi-preparative LC. Analytical LC and LC-MS were used to assess the identity and radiochemical purity of the collected fractions.
Specific Embodiments, Citation of References
[0124] The present invention is not to be limited in scope by specific embodiments described herein. Indeed, various modifications of the inventions in addition to those described herein will become apparent to these skilled in the art from the foregoing description and accompanying figures. Such modifications are intended to fall within the scope of the appended claims.
[0125] Various publications and patent applications are cited herein, the disclosures of which are incorporated by reference in their entireties. | Methods and reagents for photo-initiated carbonylation with carbon-isotope labeled carbon monoxide using alkyl/aryl iodides with alcohols pretreated by a base are provided. The resultant carbon-isotope labeled esters are useful as radiopharmaceuticals, especially for use in Positron Emission Tomography (PET). Associated kits for PET studies are also provided. | 2 |
TECHNICAL FIELD OF THE INVENTION
[0001] The present invention relates to the general art of dispensing, and to the particular field of mechanisms for dispensing material, such as toothpaste, from a tube.
[0002] Toothpaste for consumer use has long been sold in tubes requiring the user to squeeze part of the tube to extract the paste from a spout at one end of the tube. For many years, the tubes in which the toothpaste was distributed were fabricated from a malleable metal thereby permitting the user to readily extract the paste. In order to efficiently extract the maximum amount of paste from the tube, the user needed to progressively squeeze the tube from the bottom of the tube to the tube spout. As the tube was squeezed from the bottom, the metal tube could be rolled toward the tube spout, thereby effectively preventing the paste from being redistributed to the bottom of the tube should the user squeeze at a midpoint of the tube.
[0003] This process works fairly well; however, hand squeezing of such tubes to discharge the required quantity of the tube's contents often results in a badly twisted messed up partly full tube always lying in full view on top of bathroom equipment, thus spoiling the general appearance and neatness of the room. Furthermore, in many cases, the squeezing of the tube is done by careless adults or children, so that a great deal of the tube's contents is lost when the tube is discarded. Still further, it is not uncommon for children to neglect to replace the cap on a toothpaste, thus sometimes allowing the toothpaste to leak out and more often allowing the toothpaste to dry out in the tube neck. Furthermore, children have a tendency not to squeeze the tube from the end opposite the mouth, and the result is wasted toothpaste. Leakage can also result from this type of squeezing because creases tend to turn up in parts of the tube that still contain toothpaste.
[0004] The inventor has found that toothpaste tubes often become badly twisted which may cause a cracking of the tube wall thus resulting in loss of the product through the cracks when the tube is squeezed. It is not uncommon to find unsightly partially-squeezed tubes of toothpaste in bathrooms. Oftentimes, these partially-squeezed tubes are found on the bathroom counter, giving the bathroom a cluttered or messy appearance. In addition, it has been observed that a twisted tube cannot be squeezed sufficiently so as to completely expel the contents thereof thus resulting in the tube being discarded prior to complete evacuation.
[0005] Another concern with hand-squeezed toothpaste tubes is that the amount of toothpaste administered at each brushing is inconsistent. At times too much toothpaste is squeezed from the tube and administered to the toothbrush. At other times, and particularly with children, too little toothpaste is administered to the toothbrush. Furthermore, the time actually spent brushing varies from brushing to brushing and may often be less than the dentist-recommended time.
[0006] Yet another problem with hand-squeezing of toothpaste tubes is that as they are emptied, it becomes increasingly difficult to dispense toothpaste, and nine out of ten times the tube is discarded before all of the toothpaste is used. Both the over-administration of toothpaste and the difficulty of emptying the tube of toothpaste results in toothpaste being wasted.
[0007] It is also common that the toothpaste tube is shared by more than one member of a family. In the event that a toothpaste tube is shared by more than one person, hygiene considerations take effect as the toothpaste tube can spread germs from sick family members. Some people consider toiletry items, such as toothpaste tubes and toothbrushes, personal and instead of sharing a single toothpaste tube, several toothpaste tubes for each member of the family may necessarily be stored in the bathroom creating additional clutter and storage problems.
[0008] Still further, in recent years, the malleable metal tubes have been replaced by tubes fabricated from plastics materials. The new plastic tubes are still squeezable by the user to extract paste from the tube. However, the plastic material used in the new tubes tends to return to its original shape after it is deformed, thereby essentially making it impossible for the user to roll the bottom of the tube to prevent the paste from being redistributed thereto should the user squeeze at a midpoint of the tube.
[0009] Accordingly, there is a need for a toothpaste dispensing system which is capable of efficiently utilizing the toothpaste in the tube, preventing waste, and consistently administering toothpaste from brushing to brushing. What is also needed is a toothpaste system which is able to indicate the correct brushing time. What is further needed is a toothpaste dispensing system which requires minimal physical handling. Such a toothpaste dispensing system should be aesthetically pleasing, hygienic and practical in use.
[0010] Furthermore, it is very annoying to reach for the tube of toothpaste and then find that it is not in its usual spot. Therefore, there is a need for a means for storing a toothpaste tube in a readily accessible location that remains constant so that everyone will know where the toothpaste tube is.
[0011] The inventor is aware of several mechanical dispensers which can be used to dispense toothpaste. However, these dispensers require the squeezing member to travel along the length of the screw first to dispense product from a container and then reverse its direction along the screw without any work performed other than to return the squeezing member back to its origin. This requires unproductive time on the part of the user to reconfigure the dispenser for subsequent use. Further, this type of mechanism is inefficient and causes undue fatigue upon a user's fingers with manually actuated product dispensers and undue stress upon mechanical and electrical parts in an automatically actuated product dispenser, leading to accelerated mechanical and/or electrical failure of prior art product dispensers. In addition, these dispensers are generally complex in order to accommodate both forward and reverse travel of the squeezing member retained within the frame. These product dispensers have many moving parts and are not economical to manufacture or repair. Furthermore, these dispensers tend to be inconsistent in the amount of product dispensed. These dispensers are often cumbersome to use thereby making them difficult to use by small children or others who may have difficulty in coordinating the use of their hands.
SUMMARY OF THE INVENTION
[0012] The above-discussed disadvantages of the prior art are overcome by a dispensing mechanism that includes a gear system which moves a tube squeezer unit incrementally each time a button is pushed. The gear system includes a rack and pinion type unit which is connected by an interlock gear unit to a chain. A tube squeezing unit is mounted on the chain and contacts the tube to be squeezed. The chain rotates as the button is pushed and product is dispensed from the tube.
[0013] Using the embodying the present invention will permit all of the toothpaste from a tube to be used and at measured quantities. An aesthetically pleasing housing will contain the tube and the mechanism so that unsightly, partially used, twisted toothpaste tubes will not be left on a surface. Toothpaste can be dispensed without requiring the tube nozzle to touch a toothbrush thereby maintaining a sanitary condition which is not likely to pass germs from one person to another if there are multiple users.
[0014] Other systems, methods, features, and advantages of the invention will be, or will become, apparent to one with skill in the art upon examination of the following figures and detailed description. It is intended that all such additional systems, methods, features, and advantages be included within this description, be within the scope of the invention, and be protected by the following claims.
BRIEF DESCRIPTION OF THE DRAWING FIGURES
[0015] The invention can be better understood with reference to the following drawings and description. The components in the figures are not necessarily to scale, emphasis instead being placed upon illustrating the principles of the invention. Moreover, in the figures, like referenced numerals designate corresponding parts throughout the different views.
[0016] FIG. 1 is a cut away side view of a toothpaste tube squeezing mechanism embodying the present invention.
[0017] FIG. 2 is a cut away front view of a toothpaste tube squeezing mechanism embodying the present invention.
[0018] FIG. 3 is a perspective view of an interlocking gear unit included in the mechanism embodying the present invention.
[0019] FIG. 4 is an exploded perspective view of a portion of the interlocking gear unit shown in FIG. 3 .
[0020] FIG. 5 is shows a lock release mechanism included in the mechanism embodying the present invention.
[0021] FIG. 6 shows a tube squeezing unit included in the mechanism embodying the present invention.
DETAILED DESCRIPTION OF THE INVENTION
[0022] Referring to the figures, it can be understood that the present invention is embodied in a toothpaste tube squeezing mechanism 10 .
[0023] Mechanism 10 comprises a hollow housing 12 which includes a first wall 14 that is a rear wall when the housing is in a use orientation and which can be mounted on a support surface, such as a wall W or the like when the mechanism is in use. Housing 12 further includes a second wall 16 which is a top wall when the housing is in a use orientation such as shown in FIG. 1 and a third wall 18 which is a bottom wall when the housing is in a use orientation. The bottom wall has a first surface 20 which is an inside surface when the housing is in a use orientation, an indentation 22 in the inside surface and a dispensing hole 24 defined therethrough at the indentation. The use of the indentation and dispensing hole will be understood from the following description.
[0024] Housing 12 further includes a longitudinal axis 28 which extends between the top wall and the bottom wall, a fourth wall 30 which is a front wall when the housing is in a use orientation and two side walls 32 and 34 . Each side wall has an inner surface 36 with a groove 38 defined therein. The groove extends in the direction of the longitudinal axis and will serve a function that will be understood from the following disclosure.
[0025] A drive control mechanism 40 is mounted on the housing adjacent to the top wall and includes a shaft 42 which extends through the front wall toward the rear wall and which is movable toward the rear wall, the shaft can also move away from the rear wall, and shaft movement is indicated by double-headed arrow 44 . Shaft 42 has a first end 46 located near the front wall and which extends partially out of the front wall, a rear end 48 which is located near the rear wall and a body 50 which has a plurality of gear teeth 52 defined thereon.
[0026] A return spring 54 is interposed between the rear end of the shaft and the rear wall and biases the shaft toward the front wall. A second return spring 56 is located on the first end of the shaft and an operating button 58 is connected to the front end of the shaft.
[0027] Shaft 42 is moved toward the rear wall of the housing by pressing on the operating button 58 toward the rear wall of the housing. Operation of shaft 42 in this manner will operate mechanism 10 as will be understood from the teaching of the following disclosure.
[0028] An interlocking gear unit 60 is mounted on the housing to mesh with gear teeth 52 on the shaft to be rotated when shaft 42 moves toward the rear wall. Interlocking gear unit 60 includes an axle 62 having gear teeth 64 that mesh with gear teeth 52 on the shaft as shown in FIG. 3 . Axle 62 is mounted on the housing to rotate when the shaft is moved toward the rear wall of the housing.
[0029] Two primary drive gears 70 and 72 are mounted on axle 64 of the interlocking gear unit for rotation therewith. A secondary power gear 80 is mounted on the housing for rotation. Secondary power gear 80 is mounted on an axle 82 and is located to mesh with one of the primary drive gears to be rotated when the primary drive gear is rotated by rotation of the primary drive gear under the influence of the axle 62 being moved by movement of shaft 42 .
[0030] A lock release mechanism 90 is mounted on the housing and controls movement of the interlocking gear unit so that the gears will rotate in one direction when shaft 42 is pressed toward the rear wall of the housing, but will prevent reverse rotation of the gears when the shaft is released, but remains biased by spring 54 .
[0031] Lock release mechanism 90 is best shown in FIG. 5 and includes an elongate element 92 which has a head 94 that is located outside the housing adjacent to the top wall and a distal end 96 that is located adjacent to the primary drive gear. The head is accessible from outside the housing to operate the release mechanism.
[0032] A biasing element 98 is mounted on the distal end, and a primary drive gear engaging element 100 is mounted on the distal end of the biasing element. The biasing element biases the primary drive gear engaging element away from distal end 96 . Primary drive gear engaging element 100 is knife shaped to permit the primary drive gear to rotate in one direction when the primary drive gear engaging element is engaged with the primary drive gear but to prevent rotation of the primary drive gear in an opposite direction when the primary drive gear engaging element is engaged with the primary drive gear.
[0033] As indicated by double-headed arrow 102 , elongate element 92 is mounted for movement toward and away from the primary drive gear whereby the elongate element can be moved away from the primary drive gear to disengage the primary drive gear engaging element from the drive gear to permit rotation of the primary drive gear in the direction opposite to the direction of rotation of the primary drive gear under the influence of the interlocking gear unit. The elongate element 92 may be operated by a return spring around 96 and situated between 94 and 100 . This will allow mechanism 10 to be reset as will be understood from the teaching of the following disclosure.
[0034] A chain drive unit 110 is mounted on the housing to move in the direction of the longitudinal axis as indicated by double-headed arrow 112 . Chain drive unit 110 includes a chain element 114 which is meshed with secondary power gear 80 to be moved thereby when the secondary power gear is rotated as described above.
[0035] Chain element 114 is supported on a chain support 116 mounted on the housing. A chain return unit 120 is mounted on the housing and includes a return spring 122 connected to the chain and biasing the chain in a direction 112 ′ which is opposite to direction 112 ″ which is the direction of movement of the chain under the influence of the secondary power gear. Spring 122 is connected at one end thereof to chain element 114 by a plate 126 and at a second end thereof to a mounting element 128 which is fixedly mounted on the housing.
[0036] An idler gear 130 is mounted by an axle 132 on the chain support in a location that is spaced apart from the secondary power gear. Chain element 114 is trained over the idler gear to be guided thereby, and has appropriate gear engaging elements thereon.
[0037] A tube squeezing unit 140 is mounted on the housing and includes two pressure plates 142 and 144 mounted on chain 114 for movement therewith. The pressure plates have elements, such as rod 146 having balls on a distal end thereof, that slidably engage grooves 38 defined in the inner surfaces of the side walls for smooth guidance and are spaced apart from each other.
[0038] Two tensioning elements 148 and 150 are connecting the pressure plates together and bias the pressure plates toward each other.
[0039] A contact plate, such as contact plate 156 , is mounted on each pressure plat and bars, such as bars 158 , can be mounted to engage the tube if desired. The bars 158 can be small needle bearings.
[0040] Tube squeezing unit 140 is mounted on the chain element by a mounting unit 158 that includes a base 160 and two arms, such as arm 162 .
[0041] Means, such as a support frame mounted on the housing supports a tube 166 in place between the contact plates and adjacent to the chain with a dispensing port 168 of the tube accommodated in dispensing hole 24 of the bottom wall of the housing.
[0042] As can be understood from the teaching of this disclosure, the pressure plates press the tube and squeeze the tube to force product, such as toothpaste, contained in the tube out of the dispensing port when the chain is moved via the secondary power gear and the primary drive gear and the interlocking gear and the shaft of the drive control mechanism when the shaft of the drive control mechanism is moved toward the rear wall of the housing.
[0043] A cover unit 170 is located on the housing adjacent to the dispensing hole. The cover unit includes a cover element 172 hingeably mounted on the housing and an over-center element 174 which biases the cover element toward the dispensing hole when the cover has moved into a preset orientation. The cover element is moved away from the dispensing hole covering position shown in FIG. 1 to expose the dispensing portion of the tube for use, and is then moved back into the dispensing hole covering position after the product has been dispensed. Movement of the cover is indicated by double-headed arrow 176 .
[0044] Elements, such as dowels 180 , or the like, can be used to mount the housing to the wall W. Those skilled in the art will understand that other mounting elements can be used without departing from the scope of the present disclosure.
[0045] As can be understood from the foregoing disclosure, movement of shaft 42 in direction 44 ′ will rotate axle 62 in direction 62 ′ via the meshed engagement of gears 63 and 52 . Movement of axle 62 in direction 62 ′ will cause primary gears 70 and 72 to rotate in direction 72 ′. Rotation of primary gears 70 and 72 in direction 72 ′ will cause secondary gear 80 to rotate in direction 80 ′ due to the meshed engagement between those gears and the primary gears. Movement of the secondary gear in direction 80 ′ will cause movement of the chain element in direction 112 ″ which will cause tube squeezing unit 140 to move in direction 140 ′ toward the bottom wall of the housing. Movement of unit 140 in direction 140 ′ will squeeze tube 166 because the tube is stationary with respect to the squeezing unit. Such squeezing will force product from the tube out of dispensing port 168 . If a toothbrush is located beneath port 168 , the product, such as toothpaste, will move onto the toothbrush. The lock release mechanism 90 will allow chain movement in direction 112 ″, but will prevent reverse chain movement due to the jamming effect of the element 100 in the associated gear. Thus, once shaft 42 is forced toward the rear wall, the chain will move in direction 112 ″, but upon release of the shaft, return spring 54 will return the shaft into the ready-for-use position shown in FIG. 1 while the element 100 rides over the associated gears. This action will cause the tube squeezing unit to continue to move in direction 112 ″ until all of the product contained in tube 166 is exhausted.
[0046] Once the product in tube 166 is exhausted, the housing can be opened by moving front wall 30 and grasping tube 166 and removing it from the housing. The tube squeezing unit can be returned to the initial position shown in FIG. 1 by releasing lock release mechanism 90 by pulling shaft element 92 upward to disengage element 100 from the associated gear which will allow the return spring 120 to move the chain element in direction 112 ′ thereby moving tube squeezing unit 140 from adjacent to bottom wall 18 to the position shown in FIG. 1 . Once the squeezing unit is in its initial position, the lock unit can be returned to its gear locking position.
[0047] While various embodiments of the invention have been described, it will be apparent to those of ordinary skill in the art that many more embodiments and implementations are possible within the scope of this invention. Accordingly, the invention is not to be restricted except in light of the attached claims and their equivalents. | A toothpaste tube squeezing mechanism includes a housing in which a toothpaste tube is stored and a button which is pushed to dispense toothpaste from the tube. The button is connected to a tube squeezing mechanism by a gear system. | 1 |
Subsets and Splits
No community queries yet
The top public SQL queries from the community will appear here once available.