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TECHNICAL FIELD
The present invention relates to methods and devices for use in a cellular radio system using more than one uplink channel.
BACKGROUND
The Enhanced Uplink Channel (E-DCH) is a dedicated channel used by User Equipments (UEs) to transmit data in the uplink. Up to Release 8, a UE could only transmit data on one E-DCH. Third Generation Project Partnership (3GPP) is currently standardizing Dual-Cell HSUPA (High Speed Uplink Packet Access) also known as Dual Carrier HSUPA for HSPA in Release 9. In this release, a UE can transmit one E-DCH on each one of up to two uplink carriers. There have also been proposals in 3GPP to introduce multi-carrier High Speed Packet Access (HSPA) with 3-4 carriers.
When a UE configured for Dual Carrier High Speed Uplink Packet Access (DC-HSUPA) enters the CELL_DCH state only the primary uplink (hereinafter this refers to the serving E-DCH cell that corresponds to the serving HS-DSCH cell) will be activated. The other uplink carriers (hereon after referred to as secondary uplink carriers) will thus initially be deactivated. In order to allow the UE to transmit on these secondary uplink carriers the radio base station, also referred to as Node B needs to send a High Speed Shared Control Channel (HS-SCCH) activation order. Upon receiving such an order, the UE starts sending on the Dedicated Physical Control Channel (DPCCH) so that uplink synchronization can be established. Once this has been achieved the UE may start transmitting on the secondary carrier(s). Since UEs generally can achieve higher data rates by transmitting on multiple carriers simultaneously (as opposed to only transmit data on a the primary uplink carrier) the situation in which the Node B sends an activation order for the secondary uplink(s) just after entering CELL_DCH is believed to be frequently occurring.
Currently in 3GPP it has been agreed, see 3GPP Tdoc R1-092243, “Notes from RAN1 adhoc session on DC-HSUPA, DC-HSDPA MIMO, 2 ms TTI Extension and TxAA extension for non-MIMO UEs” [2] 3GPP Tdoc R1-092254, “Draft 25.214 CR for Introduction of DC-HSUPA” that when a UE receives an HS-SCCH order for activating the secondary uplink carrier the initial DPCCH transmit power should be computed as:
Uplink DPCCH transmit power= P DCCH,1 −UE_Sec — Tx _Power_Backoff. (equation 1)
Here P DCCH,1 is the DPCCH transmit power on the primary uplink carrier and UE_Sec_Tx_Power_Backoff is a parameter that is configured by the Radio Network Controller (RNC) when the UE enters CELL_DCH. In principle, this could take on either positive or negative values. The latter implies that the initial DPCCH power on the secondary carrier exceeds the DPCCH power used on the primary carrier. Note also that the back-off could reflect both static parameters (such as potential differences in carrier frequency) and dynamic parameters (e.g., cell load) which change over time.
For example, if the load on the secondary uplink carrier at the time-instance the UE enters CELL_DCH is higher than the loading on the primary carrier and the Node B would activate the secondary carrier within a time-period so short so that the loading conditions on the carriers would not have changed it could be advantageous to use a negative back-off value (i.e. an initial DPCCH power on the secondary that exceeds the DPCCH power level on the primary carrier) since this would reduce the time-duration until synchronization for the secondary uplink carrier is achieved.
There is a constant desire to improve performance in existing cellular radio systems. Hence, there exist a need for a method and a system that enables an improved setting of the back off for secondary carriers in a Multi carrier cellular radio system.
SUMMARY
It is an object of the present invention to provide an improved setting of back-off parameters for the secondary carrier(s) in cellular radio systems.
This object and others are obtained by the method and the device as set out in the appended claims.
As noted above the back-off (UE_Sec_Tx_Power_Backoff) is configured by the RNC when the UE enters CELL_DCH. However, as has been recognized by the inventor, the secondary uplink carrier can be activated, deactivated, and reactivated at numerous and different times. Thus, the load conditions for the two (or more) carriers may have changed as compared to when the UE initially entered CELL_DCH state. As the back-off UE_Sec_Tx_Power_Backoff is configured by the RNC the same value would have to be used every time the Node B activated (and/or reactivated) the secondary uplink carrier. Because it is undesirable that the UE use a too high initial DPCCH power on its secondary uplink carrier, the RNC would have to take potential load variations into account when determining the value of the back-off. In fact, this will require that the back-off UE_Sec_Tx_Power_Backoff is set conservatively, which in turn will result in unnecessary high delays for achieving synchronization on the secondary uplink carrier in the situation where it is activated just after the UE enters CELL_DCH state.
In accordance with one embodiment a method of selecting transmit power used for physical uplink Control Channel and Data Channel, such as a Dedicated Physical Control Channel, on a secondary carrier used by a user equipment when transmitting data on the secondary carrier in a cellular radio system is provided. The method can comprise the steps of determining a time-varying back-off value for the uplink Control Channel and Data Channel power level, and selecting the received time-varying back-off value to update the uplink Control Channel and Data Channel transmit power. Hereby, an improved performance in the cellular radio system can be achieved.
In accordance with one embodiment the time varying back-off value is received in a message signaled from the cellular radio system network over the air interface. The time varying back-off value can also be determined by some relation in the applicable standard in which case there is no need for signaling the back-off value over the air interface.
In accordance with the present invention a time-varying back-off value is used whereby differences in cell load can be taken into account for a restricted time-period during which the information is believed to be valid. Also, other time-varying variables of interest for the initial DPCCH power setting of the secondary carrier can be taken into account when setting the back-off value. Examples of such other variables can be the carrier frequency used or the user/service type.
In accordance with one embodiment the time varying back off value can be set:
When the UE enters the CELL_DCH state and the radio base station Node B subsequently sends an HS-SCCH order for activation of the secondary uplink carrier, When the UE is deactivated and subsequently reactivated and the elapsed time-duration between de and reactivation is smaller than a certain value. In this case the UE can base the initial DPCCH power of the secondary uplink carrier on the last used power level.
In accordance with one embodiment a method in a network node for generating transmit power value for use in a user equipment used for physical uplink Control Channel and Data Channel on a secondary carrier used by the user equipment when transmitting data on the secondary carrier in a cellular radio system is provided. The method can comprise the steps of generating a time-varying back-off value for the uplink Control Channel and Data Channel power level, and transmitting the time-varying back-off value to the user equipment.
It will be appreciated various processes and methods described may be substantially represented in a computer-readable medium and can be executed by a computer or processor.
The methods and functions in accordance with the above can be provided through the use of a device comprising dedicated hardware as well as hardware capable of executing software. When provided by a processor, the functions may be provided by a single dedicated processor, by a single shared processor, or by a plurality of individual processors, some of which may be shared or distributed. Moreover, a “processor” or “controller” may include, without limitation, digital signal processor (DSP) hardware, ASIC hardware, read only memory (ROM), random access memory (RAM), and/or other storage media.
BRIEF DESCRIPTION OF THE DRAWINGS
The present invention will now be described in more detail by way of non-limiting examples and with reference to the accompanying drawings, in which:
FIG. 1 is a general view of a cellular radio system
FIGS. 2 and 3 are views illustrating power control schemes,
FIG. 4 is a flow chart illustrating some procedural steps when selecting back off value,
FIG. 5 is a flow chart illustration some procedural steps performed when generating a time varying back off value,
FIG. 6 is a view of a user equipment adapted to use a time-varying back off value, and
FIG. 7 is a view of a control device for generating a time varying back off value.
DETAILED DESCRIPTION
The present invention will now be described in more detail by way of non-limiting examples. Although focus in the below description is on the case where the UE enters the CELL_DCH state (since Dual-Carrier HSUPA is limited to this state in Release 9 ), the invention is applicable to other states (e.g., CELL_FACH) as well if the UE is allowed to transmit on multiple carriers and some of the carriers can be deactivated. The description below is given in the context of a Wideband Code Division Multiple Access (WCDMA) system However, the invention can also be used for other technologies in which multiple carriers can dynamically aggregated (activated/deactivated) by the network on a demand basis. One such example is “carrier aggregation” for Long Term Evolution (LTE)-Advanced.
In FIG. 1 , a general view of a cellular radio system 100 is shown. The system 100 comprises a number of cells 101 together covering a geographical area in which the system 100 provides radio access. Each cell 101 is associated with a radio base station 103 , which communicates with a Radio Network Controller (RNC) 105 . The RNC is in turn connected to a Core Network (CN) 107 . In the geographical area covered by the cellular radio system a mobile station here termed user equipment (UE) 109 may connect to the cellular radio system via a radio base station 203 over an air-interface. The UE 109 can be connected to the system with two or more uplink carriers. The UE 109 can be connected to more than one radio base station 103 simultaneously.
In Dual-Carrier HSUPA a UE can be allowed to transmit data on two uplink carriers using two Enhanced Dedicated Channel (E-DCH) channels. In future releases the UE may be allowed to transmit data on even more carriers.
When a UE enters CELL_DCH and is configured on multiple cells on the uplink only the primary uplink carrier is activated. The initial state of secondary carriers is thus deactivated. In order for the UE to be allowed and transmit data on them the Node B needs to send an HS-SCCH activation order. Upon receiving this activation order the UE starts its synchronization procedure by sending DPCCH on the secondary uplink with an initial power level.
In 3GPP it has been agreed that if the UE receives HS-SCCH activation order the initial DPCCH power level on the secondary uplink carrier should be:
Uplink DPCCH transmit power= P DCCH,1 −UE_Sec — Tx _Power_Backoff (equation 2),
i.e. the DPCCH power level used on the primary carrier minus some back-off configured by the Radio network Controller (RNC) when the UE enters the CELL_DCH state. Note that this back-off can both be positive and negative. A negative back-off would reflect the situation where the initial DPCCH power on the secondary carrier is greater than the DPCCH power on the primary carrier. Because the initial state of the secondary carrier always is deactivated and UE in most circumstance can achieve higher data rate if it is allowed to transmit on both carriers the situation where the secondary uplink carrier is activated just after the UE enters CELL_DCH will be common. To achieve higher data rates in such situations it has been found advantageous to have a dynamic back-off that, for example, depends on some parameter(s) such as the relative cell loading.
In addition, the secondary carrier can be activated, de activated, and reactivated at numerous and different time-instances. As has been realized, the loading conditions at these may be very different from those that the UE experienced when it initially entered CELL_DCH. Hence, if the same back-offs are used every time the secondary carrier is activated it is not possible to account for time-varying aspects, such as cell load.
In order to exploit the fact that the situation in the system is time varying a time-dynamic power back-off is used. In accordance with one embodiment, this is achieved by configuring two back-off values when the UE enters CELL_DCH. These can be referred to as UE_Backoff_ 1 and UE_Backoff_ 2 . UE_Backoff_ 1 denotes the back-off that considers the cell load (and possibly other time-varying effects) while UE_Backoff_ 2 corresponds to a long-term default back-off that can be used when no (or only outdated) information about the cell load is available to the UE.
In accordance with one embodiment the two back off parameters for setting the Uplink DPCCH transmit power configured as UE_Backoff_ 1 and UE_Backoff_ 2 can be transmitted to the UE as UE_Backoff_ 1 and Δ=UE_Backoff_ 2 −UE_Backoff_ 1 since this can reduce necessary signaling overhead. Also this will allow the UE to retrieve UE_Backoff_ 2 =Δ+UE_Backoff_ 1 . Moreover, if the UE is in Soft Handover (SHO) the values of UE_Backoff_ 1 and UE_Backoff_ 2 can be set to depend on the relative loading in all of the carriers belonging to the activate set for the particular UE.
In accordance with one embodiment the UE that has entered CELL_DCH and obtained UE_Backoff_ 1 and UE_Backoff_ 2 can update the value of UE_Backoff_ 1 according to some method, for example expressed as:
( UE _Backoff — 1) t =f ( UE _Backoff — 1, t ) (equation 3)
so that it after a certain time-duration—beyond which the cell load when the UE entered the CELL_DCH state—is considered to be outdated. After this time-instance the UE utilizes UE_Backoff_ 2 . In the equation 3, UE_Backoff_ 1 is the initial value of the back-off that was configured when the UE entered CELL_DCH, t the time-duration that has elapsed since the UE entered CELL_DCH, and (UE_Backoff_ 1 ) t the value of the back-off that the UE should utilize after a time-duration t has elapsed, and f denotes a function.
Below some exemplary settings for a time dynamic setting of back off parameters in accordance with the above are given. Again the examples are given in the context of two parameters. A few examples on how the UE_Backoff_ 1 and UE_Backoff_ 2 could be configured and how UE_Backoff_ 1 could be updated are illustrated in FIG. 2 and FIG. 3 respectively. Note that other schemes for updating UE_Backoff_ 1 are possible.
In FIG. 2 an example illustrating how UE_Backoff_ 1 and UE_Backoff_ 2 can be configured and updated in a scenario where the cell load on the secondary serving E-DCH cell exceeds the load on the primary cell. In the figure the solid and dash-dotted curves represents two ways of updating the value of UE_Backoff_ 1 .
In FIG. 3 an example on how UE_Backoff_ 1 and UE_Backoff_ 2 can be configured in a setting where the cell load in a secondary serving E-DCH cell is smaller than the load in the primary serving E-DCH cell. In the figure the solid and dash-dotted curves represents two ways of updating the value of UE_Backoff_ 1 .
The UE_Backoff_ 1 can be updated when the UE has its secondary uplink carrier activated. In situations where the secondary carrier is deactivated and thereafter again reactivated the value of UE_Backoff_ 1 can be used as initial power DPCCH power level for the secondary carrier. This situation can for example occur when downlink synchronization is lost on the secondary and/or primary downlink carrier. Note also that the UE, once it stops transmitting on the secondary uplink carrier, can be configured to update its value of UE_Backoff_ 1 . This can for example be performed using the method described above in conjunction with equation 3 (used for updating UE_Backoff_ 1 when the UE has entered CELL_DCH) until it the information becomes outdated and the value of UE_Backoff_ 1 reaches UE_Backoff_ 2 .
In FIG. 4 a flowchart illustrating some procedural steps performed when selecting Uplink DPCCH transmit power on a secondary carrier used by a user equipment when transmitting data on the secondary carrier are depicted. First, in a step 401 a time-varying back-off value for the Dedicated Physical Control Channel power level of the secondary carrier is received. Next, in a step 403 , the received time-varying back-off value is selected to update the Dedicated Physical Control Channel transmit power of the secondary carrier.
In FIG. 5 , a flowchart is show that illustrates some procedural steps performed in control device of a system node of a cellular radio system when generating back-off value for the Dedicated Physical Control Channel transmit power of the secondary carrier used by a user equipment in uplink transmission. First, in a step 501 , a time a time-varying back-off value for the Dedicated Physical Control Channel power level of the secondary carrier is generated. Next, in a step 503 , the time-varying back-off value is transmitted to the user equipment.
In FIG. 6 a user equipment 600 adapted to implement the methods as described herein. The user equipment 600 can comprise a micro processor 601 operating on a set of computer program instructions stored in a memory 603 . The computer program instructions cause the user equipment to perform the methods as described herein when executed by the micro processor 601 .
In FIG. 7 , a control device 700 adapted to be implemented or integrated in a node of a cellular radio system is depicted. The control device can in particular be implemented in a radio network controller or a radio base station of a cellular radio system. The node in which the control device is implemented will typically depend of the technology used in the cellular radio system at hand for a particular implementation. The control device 700 can comprise a micro processor 701 operating on a set of computer program instructions stored in a memory 703 . The computer program instructions cause the control device to perform the methods as described herein when executed by the micro processor 701 .
While the above examples have been given in the context of UE being in CELL_DCH state the same method can be applied for other states, e.g., CELL_FACH state if the UE is allowed to transmit on multiple carriers and some of the carriers can be deactivated and activated such as a state. In addition, the invention can also be used in other technologies wherein multiple carrier can be dynamically aggregated (activated and deactivated) by the network on a demand basis such as for LTE (Advanced).
Using the method and device as described herein for selecting a dynamic back-off for the initial DPCCH power level of a secondary carrier, in particular a secondary serving E-DCH cell will reduce the synchronization delay when the secondary carrier is activated and knowledge about the current cell loadings exist, and at the same time minimize the risk that the UE uses an initial power level that is too high on its secondary carrier when the relative cell load information is outdated or otherwise inaccurate. | In a method and a device a time-varying back-off value is used whereby differences in cell load can be taken into account for a restricted time-period during which the information is believed to be valid. Also, other time-varying variables of interest for the initial DPCCH power setting of the secondary earner can be taken into account when setting the back-off value. | 7 |
FIELD OF THE INVENTION
[0001] The present invention relates to a plasma display panel. More particularly, the present invention relates to a closed cell type alternating current (AC) plasma display panel capable of improving the address margin.
BACKGROUND OF THE INVENTION
[0002] Plasma display panels (PDPs) are classified depending on how the discharge cells thereof are arranged. Two main types of PDPs are strip PDPs, in which gas discharge spaces are arranged in a strip pattern, and closed cell PDPs, in which individual cells are defined by enclosed partition barrier ribs.
[0003] Referring to FIG. 1A , the conventional AC plasma display panel 80 is provided with a front substrate 82 and a rear substrate 83 opposing each other and separated by a discharge space. A plurality of pairs of strip scanning electrodes 86 and sustaining electrodes 87 are arranged substantially in parallel and covered with a dielectric layer 84 and a protective coating 85 on the front substrate 82 . A plurality of strip address electrodes 88 are formed substantially in parallel on the rear substrate 83 in the direction perpendicular to the scanning electrode 86 and the sustaining electrode 87 . Strip barriers 89 are arranged between the address electrodes 88 . Phosphors 90 are formed between the barriers 89 and on the sidewalls of the barriers so as to cover the address electrodes 88 . Spaces surrounded by the surface substrate 82 , the rear substrate 83 and the barriers 89 form discharge cells 91 . The spaces in the discharge cells 91 are filled with gases radiating ultraviolet light due to discharge.
[0004] Referring to FIG. 1B , the phosphor 90 comprises a blue phosphor 90 b , a green phosphor 90 g and a red phosphor 90 r , one of which is formed in each discharge cell. Thus, the discharge cell provided with the blue phosphor 90 b constitutes a blue discharge cell 91 b , the discharge cell provided with the green phosphor 90 g constitutes a green discharge cell 91 g , and the discharge cell provided with the red phosphor 90 r constitutes a red discharge cell 91 r.
[0005] The above-described configuration, however, has a problem in that the discharge starting voltage of the green discharge cell 91 g is different from that of the other two discharge cells 91 b and 91 r . FIG. 1C shows write voltages necessary to perform a write discharge in a stable manner when a constant voltage is applied to the scanning electrodes 86 in the write operation in the address period (complete lighting write voltages) with respect to the discharge cells of respective colors. As described above, in the conventional panel, the discharge cells have write voltages that differ from color to color. As a result, as is clearly shown in FIG. 1C , the discharge cells have complete lighting write voltages that are considerably different depending on their colors. Thus, applying the same write voltage to all the discharge cells can cause unstable write discharge, erroneous discharge or discharge flicker, leading to improper display.
[0006] In order to perform a stable write operation, the write voltage applied to the address electrodes 88 must change depending on the colors of the discharge cells in accordance with the complete lighting write voltage of the discharge cells of respective colors. This complicates the voltage control, however, and increase the cost of the apparatus.
SUMMARY OF THE INVENTION
[0007] Embodiments of the invention provide a cell structure for an AC plasma display panel with equivalent complete lighting write voltages of the R, G, and B discharge cells to improve the address margin of the panel.
[0008] Embodiments of the present invention further provide different addressing electrode areas of respective colors for an AC plasma display panel with equivalent complete lighting write voltages of the discharge cells to improve the address margin of the panel.
[0009] To achieve these and other advantages, embodiments of the invention provide a closed cell type AC plasma display panel, comprising a first substrate and a second substrate opposing the first substrate. The first substrate and the second substrate are provided with a predetermined gap therebetween. Barrier ribs are interposed between the first substrate and the second substrate. The barrier ribs define a plurality sets of a first, a second and a third discharge cell. A plurality of address electrodes are formed on the first substrate in the first, the second, and the third discharge cells along a first direction. A plurality of sustain electrodes are formed on the second substrate in the first, the second, and the third discharge cells along a second direction, wherein each area of the sustain electrodes in the first, the second, and the third discharge cells are substantially equal, and at least one area of the address electrodes in the first, the second, and the third discharge cells is different from other areas of the address electrodes in the first, the second, and the third discharge cells.
[0010] It is understood that the first, the second and the third discharge cell sets corresponding to the first color, the second color, and the third color, and the discharge cells sets can be arranged in triangular shape. Each of the present individual discharge spaces is formed in a quadrangular shape or hexagonal shape.
BRIEF DESCRIPTION OF THE DRAWINGS
[0011] The present invention can be more fully understood by reading the subsequent detailed description in conjunction with the examples and references made to the accompanying drawings, wherein:
[0012] FIG. 1A is a partially cutaway perspective view illustrating a schematic configuration of a conventional AC type plasma display panel;
[0013] FIG. 1B is a cross section of FIG. 1A taken along the line B-B in the direction indicated by the arrow;
[0014] FIG. 1C shows write voltages necessary to perform a write discharge in a stable manner;
[0015] FIG. 2A is a schematic front view of rear substrate of an AC type plasma display panel according to the first embodiment of the present invention;
[0016] FIG. 2B is a cross section of FIG. 2A taken along the line V-V in the direction indicated by the arrow;
[0017] FIGS. 2C and 2D show the shape of large electrode portions of address electrode according to the first embodiment of the present invention;
[0018] FIG. 3 is schematic front view of the second substrate of an AC plasma display panel according to the second embodiment of the present invention; and
[0019] FIG. 4 is a schematic front view of rear substrate of an AC plasma display panel according to the third embodiment of the present invention.
DETAILED DESCRIPTION
First Embodiment
[0020] The embodiment of the invention provides a closed cell type AC plasma display panel. FIGS. 2A to 2 D illustrate the first embodiment of the closed cell type AC plasma display panel. In a plasma display panel (PDP) according to a first embodiment of the present invention, a plurality of discharge cell sets comprising R, G, and B colors are defined by barrier ribs partition, each set a substantially along the first direction (X) to forming a closed type PDP. Each discharge cell is independently controlled to display predetermined images.
[0021] Referring to FIG. 2A , the PDP 100 includes a first substrate 102 (also known as a rear substrate) and a second substrate 101 (also known as a front substrate). Rear substrate 102 and front substrate 101 are disposed substantially in parallel with a predetermined gap therebetween.
[0022] Barrier ribs 130 are disposed at a predetermined height between rear substrate 102 and front substrate 101 in a ladder-shaped pattern along the first direction (X). Barrier ribs 130 define a plurality of discharge spaces 140 R, 140 G, and 140 B. In the present embodiment of the invention, each set of discharge spaces 140 R, 140 G, and 140 B is arranged substantially in a first direction, while each of the individual discharge spaces 140 R, 140 G, and 140 B is formed in a quadrangular shape.
[0023] A plurality of address electrodes 110 is formed on rear substrate 102 along the second direction (Y). Address electrodes 110 are formed both within and outside of discharge spaces 140 R, 140 G, and 140 B. Also, a first dielectric layer 106 is formed over the surface of rear substrate 102 covering address electrodes 110 .
[0024] The address electrodes 110 include small electrode portions 110 a in Y direction, and large electrode portions 110 b formed within discharge spaces 140 R, 140 G, and 140 B. The widths of the large electrode portions 10 b vary with different discharge spaces 140 R, 140 G, and 140 B and denote as W R , W G , W B , respectively.
[0025] A plurality of sustain electrodes 120 are formed on front substrate 101 along direction X. Sustain electrodes 120 include main electrode portions 120 , which are positioned corresponding to portions of barrier ribs 130 extending along direction X, and branch electrode portions 124 , extending from main electrode portions 120 into areas corresponding to formation of discharge spaces 140 R, 140 G, and 140 B. Two branch electrode portions 124 extend from two main electrode portions 120 of different sustain electrodes in each discharge space 140 R, 140 G, and 140 B. Branch electrode portions 124 include first electrode portion 124 a that extends perpendicularly from main electrode portions 120 , and second electrode portion 124 b that enlarges on a distal end of first electrode portion 124 a extending parallel to the main electrode portions 120 . Within one discharge space, a gap G P is formed between two second electrode portions 124 b extending into discharge space from opposite directions, that is, from two different main electrode portions 120 .
[0026] In the present embodiment, a bus electrode can be formed on the main electrode portions 120 . The bus electrode comprises an opaque material, such as Ag metal or like, and the sustain electrodes 120 comprise a transparent material, such as indium tin oxide (ITO) or like. Referring to FIG. 2B , transparent second dielectric layer 104 is formed over front substrate 101 covering sustain electrodes 120 . Additionally, protective layer 105 comprising MgO or like is formed over second dielectric layer 104 .
[0027] Phosphor layers 108 R, 108 G, and 108 B are formed in discharge spaces 140 R, 140 G, and 140 B, respectively. Phosphor layers 108 R, 108 G, and 108 B cover first dielectric layer 106 and are formed extending up the side-walls of barrier ribs 130 . In present embodiment, BaMgAl 10 O 17 :Eu is used as the blue phosphor 108 B, Zn 2 SO 4 :Mn is used as the green phosphor 108 G, and (Y 2 Gd)BO 3 :Eu is used as the blue phosphor 108 B.
[0028] In FIG. 2A , address electrodes 110 include large electrode portions 110 b positioned in discharge spaces 140 R, 140 G, and 140 B, and small electrode portions 110 a are positioned under barrier ribs 130 between discharge spaces 140 R, 140 G, and 140 B. Large electrode portions 110 b have widths W R , W G , and W B that are greater than widths of the small electrode portions 110 a.
[0029] The widths W R , W G , and W B are made different depending on the material properties of the R, G, and B phosphor layers 140 R, 140 G, and 140 B. In present embodiment of the invention, widths W R , W G , and W B of large electrode portions 110 b for the R. G, and B pixels, respectively, satisfy the following condition.
W B ≦W R ≦W G .
[0030] The width W G of the large electrode portion 110 b for the G pixel is made larger than the widths W R and W B of large electrode portions 10 b for the R pixel and the G pixel, respectively, due to the creation of wall discharges on the phosphor layers by application of the write voltage during an address period. The creation of wall charges determines lighting of discharge cells in a sustaining period. As such, the write voltage of G phosphor layer 108 G exceeds the write voltages of R and B phosphor layers 108 R and 108 B. More specifically, by varying the widths W R , W G , and W B of large electrode portions 10 b , the address margins of the R, G, and B pixels can be improved.
[0031] The shape of large electrode portions 10 b of address electrodes 110 is not limited to a quadrangular shape and can be formed in a circular shape 110 b C as shown in FIG. 2C , and various polygonal shapes such as a hexagonal shape 110 b H as shown in FIG. 2D .
[0032] In the present embodiment, since discharge cells of all colors have substantially the same complete lighting write voltages, with increased address margins, write operations among the discharge cells of all colors during sustaining period are uniform, thus preventing display flickering, erroneous write operations and improving the address margins and voltage margins during the sustaining period in the panel. This indicates that a stable write operation (address operation) can be achieved as shown in FIG. 1C (dotted line II). Furthermore, the minimum voltage necessary for writing to the discharge cells of respective colors is considerably lower compared with that necessary for the conventional panel. Thus, a low-cost integrated circuit (IC) can be used for a write pulse generating circuit.
[0033] The configurations of discharge cells R, G, and B of present embodiments of the invention are not limited to a linear sequence and can be formed in triangular arrangement, while each of the individual discharge spaces R, G, and B is formed in a quadrangular shape as shown in FIG. 3 , and various polygonal shapes such as a hexagonal shape in an overall structure of a honeycomb as shown in FIG. 4 .
Second Embodiment
[0034] A plurality of discharge cells 240 R, 240 G, 240 B are defined by sets of barrier ribs, each set forming a substantially triangular arrangement (i.e., delta-nabla structure) sequence to realize a closed type PDP. Each discharge cell is independently controlled to display predetermined images, and each discharge cell is quadrangular shape.
[0035] Referring to FIG. 3 , address electrodes 210 include large electrode portions 210 b that are positioned in discharge spaces 240 R, 240 G, and 240 B, and small electrode portions 210 a positioned under barrier ribs 130 between discharge spaces 240 R, 240 G, and 240 B. Large electrode portions 210 b have widths W R , W G , and W B greater than widths W R , W G , and W B of small electrode portions 210 a.
[0036] Branch electrode portions 224 include first electrode portion 224 a that extends perpendicularly from main electrode portions 220 , and second electrode portion 224 b that enlarges on a distal end of first electrode portion 224 a to extend parallel to main electrode portions 220 . Within one discharge space, a gap G P is formed between two second electrode portions 224 b extending into the discharge space from opposite directions, that is, from two different main electrode portions 220 .
[0037] The widths W R , W G , and W B are made different depending on the material properties of the R, G, B phosphor layers 240 R, 240 G, and 240 B. In the present embodiment of the invention, the widths W R , W G , and W B of large electrode portions 210 b for the R, G, and B pixels, respectively, satisfy the following condition.
W B ≦W R ≦W G .
[0038] The width W G of the large electrode portion 210 b for the G pixel is made larger than widths W R and W B of large electrode portions 210 b for the R pixel and the B pixel, respectively, due to the creation of wall discharges on the phosphor layers by application of the write voltage during the address period. The creation of wall charges determines the lighting of discharge cells in the sustaining period. As such, the write voltage of G phosphor layer exceeds the write voltages of R and B phosphor layers. More specifically, by varying the widths W R , W G , and W B of large electrode portions 110 b , the address margins of the R, G, and B pixels can be improved.
[0039] The shape of large electrode portions 110 b of address electrodes 110 is not limited to a quadrangular shape and can be formed in a circular shape 110 b C as shown in FIG. 2C , and various polygonal shapes such as a hexagonal shape 110 b H as shown in FIG. 2D .
[0040] In the present embodiment, since discharge cells of all colors have substantially the same complete lighting write voltages, with increased address margins, write operations among the discharge cells of all colors during the sustaining period are uniformed, thus preventing display flickering, erroneous write operations, and improving address margins and voltage margins during the sustaining period in the panel. This indicates that a stable write operation (address operation) can be achieved as shown in FIG. 1C (dotted line II). Furthermore, the minimum voltage necessary for writing to the discharge cells of respective colors is considerably lower compared with that necessary for the conventional panel. Thus, a low-cost IC can be used for a write pulse generating circuit.
Third Embodiment
[0041] A plurality of discharge cells 340 R, 340 G, 340 B are defined by sets of barrier ribs, each set forming a substantially hexagonal (i.e., honeycomb structure) sequence to realize a closed type PDP. Each discharge cell is independently controlled to display predetermined images.
[0042] Referring to FIG. 4 , address electrodes 310 include large electrode portions 310 b that are positioned in discharge spaces 340 R, 340 G, and 340 B, and small electrode portions 310 a positioned under barrier ribs 330 between discharge spaces 340 R, 340 G, and 340 B. Large electrode portions 310 b have widths W R , W G , and W B greater than widths of small electrode portions 310 a.
[0043] Branch electrode portions 324 include first electrode portion 324 a that extends perpendicularly from main electrode portions 320 , and second electrode portion 324 b that enlarges on a distal end of first electrode portion 324 a to extend parallel to main electrode portions 320 . Within one discharge space, a gap G P is formed between two second electrode portions 324 b extending into the discharge space from opposite directions, that is, from two different main electrode portions 320 .
[0044] The widths W R , W G , and W B are made different depending on the material properties of the red (R), green (G), and blue (B) phosphor layers 340 R, 340 G, and 340 B. In the present embodiment of the invention, the widths W R , W G , and W B of the large electrode portions 310 b for the R, G, and B pixels, respectively, satisfy the following condition.
W B ≦W R ≦W G .
[0045] The width W G of the large electrode portion 310 b for the G pixel is made larger than widths W R and W B of large electrode portions 310 b for the R pixel and the B pixel, respectively, due to the creation of wall discharges on the phosphor layers by application of the write voltage during an address period. The creation of wall charges determines the lighting of discharge cells in the sustaining period. As such, the write voltage of G phosphor layer exceeds the write voltages of R and B phosphor layers. More specifically, by varying the widths W R , W G , and W B of large electrode portions 310 b , the address margins of the R, G, and B pixels can be improved.
[0046] The shape of large electrode portions. 110 b of address electrodes 110 is not limited to a quadrangular shape and can be formed in a circular shape 110 b C as shown in FIG. 2C , and various polygonal shapes such as a hexagonal shape 110 b H as shown in FIG. 2D .
[0047] In present embodiment, since discharge cells of all colors have substantially the same complete lighting write voltages, with increased address margins, write operations among the discharge cells of all colors during sustaining period are uniform, thus preventing display flickering, erroneous write operations, and improving the address margins and voltage margins during the sustaining period in the panel. This indicates that a stable write operation (address operation) can be achieved as shown in FIG. 1C (dotted line II). Furthermore, the minimum voltage necessary for writing to the discharge cells of respective colors is considerably lower compared with that necessary for the conventional panel. Thus, a low cost IC can be used for a write pulse generating circuit.
[0048] While the invention has been particularly shown and described with reference to preferred embodiments, it will be readily appreciated by those of ordinary skill in the art that various changes and modifications may be made without departing from the spirit and scope of the invention. It is intended that the claims be interpreted to cover the disclosed embodiment, those alternatives, which have been discussed above, and all equivalents thereto. | A closed type AC plasma display panel. A first substrate and a second substrate are provided with a predetermined gap therebetween. Barrier ribs are interposed between the first substrate and the second substrate. The barrier ribs define a plurality sets of a first, a second and a third discharge cell. A plurality of address electrodes is formed on the first substrate in the first, the second, and the third discharge cells along a first direction, and a plurality of sustain electrodes formed on the second substrate in the first, the second, and the third discharge cells along a second direction, wherein each area of the sustain electrodes are substantially equal and at least one area of the address electrodes is different from others area of the address electrodes in the first, the second, and the third discharge cells. | 7 |
FIELD OF THE INVENTION
The present invention is generally directed toward a system for supporting objects on a roof, or other surface.
BACKGROUND OF THE INVENTION
The roof-tops of commercial and industrial buildings are often used to support items such as pipes, HVAC components, cable trays, electrical conduits, walkways, and drainage systems. The items often need to be elevated above the surface of the roof-top to prevent damage to the roof.
Most commonly, pipes need to be supported above the roof-top. Some of these are for condensate drains for roof-top HVAC systems. Other pipes are used for roof-top drainage, or for steam and liquids, or even as electrical conduits. Because the roofs often have uneven surfaces, the pipes are raised above the roofs and are supported at regular intervals to prevent them from sagging. The supports are especially important at junctions, couplings, and turns because stress at these junctures is more likely to result in a leak.
SUMMARY OF THE INVENTION
Prior to the development of the present invention, roof-top installations required the use of several different types of supports such as boards, strut channel stands, and suspension straps. The present invention provides a support system that is easily adjustable in height and can easily be adapted for many different uses, including supporting pipes, pipe junctions, vertical struts, horizontal struts, and threaded rods. Due to the design, the present invention allows for fast installation, utilizes fewer supports, and reduces the likelihood of roof damage. It can easily be adjusted without tools as part of normal maintenance to accommodate shifts in roofs.
BRIEF DESCRIPTION OF THE DRAWINGS
Further advantages of the invention will become apparent by reference to the detailed description of preferred embodiments when considered in conjunction with the drawings:
FIG. 1 depicts a perspective view of the multi-purpose roof-top support from above.
FIG. 2 is a front elevation view of the multi-purpose roof-top support.
FIG. 3 is a side elevation view of the multi-purpose roof-top support.
FIG. 4 is top plan view of the multi-purpose roof-top support.
FIG. 5 is a bottom plan view of the base plate 2 .
FIG. 6 depicts a perspective view of the multi-purpose roof-top support form above.
FIG. 7 depicts a cross-section view along line 7 - 7 of FIG. 4 of the multi-purpose roof-top support with a vertical strut channel installed.
FIG. 8 depicts a multi-purpose roof-top support with threaded rods and a horizontal strut channel attached.
FIGS. 9 a and 9 b depicts a perspective view from above and below, respectively, of the multi-purpose roof-top support form above.
FIG. 10 depicts a perspective view of the top plate of the multi-purpose roof-top support with pipes and T-straps.
FIG. 11 depicts a perspective view of the top plate of the multi-purpose roof-top support with pipes with a T-junction, threaded rods, a horizontal strut channel, a vertical strut channel, and T-straps.
DETAILED DESCRIPTION
The following detailed description is presented to enable any person skilled in the art to make and use the invention. 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 invention. The present invention is not intended to be limited to the embodiments shown, but is to be accorded the widest possible scope consistent with the principles and features disclosed herein.
As can be seen from FIG. 1 , the multi-purpose roof-top support is comprised of two main components: a top plate 1 and a rotating base plate 2 . The top plate 1 serves to directly support the objects that are to be raised above the surface of the roof. The top plate 1 includes indentations 7 for pipes or pipe junctions to rest in. Additionally, the top plate 1 includes holes 6 for connecting fasteners and threaded rods 15 and a rectangular opening 8 that allows the support to accept a vertical strut channel 14 , such as those manufactured under the SUPERSTRUT or KINDORF strut brand (THOMAS & BETTS CORPORATION).
The top plate 1 has outer threads 4 which engage into the base plate's inner threads 21 . The base plate 2 , preferably, has a generally conical shape, with a flat perforated plate 11 on the side closest to the roof. The perforations 20 allow rain water to pass through the base plate 2 and also allow small roof-top aggregate to enter the base plate 2 , rather than being pushed into the roof and causing damage to the roof membrane.
Preferably, base plate 2 rests upon a mat 3 . The mat 3 can be made of any soft material, including an elastomeric material. The mat 3 serves to prevent the base plate 2 from sliding and further helps prevent aggregate from being pushed through the roof. Mat 3 also serves to distribute the vertical load across the bottom of base plate 2 .
Installation of this roof-top support is simple. The installer first places the mat 3 directly on the roof, with as little aggregate below it as possible. Base plate 2 will be placed directly on the mat 3 . The installer can then place the top plate 1 against the bottom of the object to be supported and lower the top plate 1 onto base plate 2 . Base plate 2 is then rotated such that outer threads 4 of top plate 1 engage with inner threads 21 of base plate 2 . As the installer continues to rotate base plate 2 , the overall height of the support decreases, and the object to be supported is lowered. The installer stops rotating base plate 2 when the desired height is reached.
As mentioned previously, top plate 1 is adaptable to support various objects. Top plate 1 includes wide indentations 7 to support pipes of larger diameter. It also can include narrow indentations 10 to support multiple pipes with narrower diameters. This is advantageous over prior art roof-top supports which can only support a single pipe per support. As will be appreciated from FIG. 10 , recessed area 9 allows pipe junctions to easily be supported with a single support device. This, too, is advantageous over prior art support devices that require supports on either side of the junction to protect this most vulnerable part of the pipe. The unique arrangement of the indentations 7 on top plate 1 allows the claimed device to support a 90-degree elbow junction or T-junction with just a single support.
The pipes 18 , may be secured with flexible T-straps 17 , which can be included as part of a kit. The T-straps 17 are narrow strips of flexible, but resilient, material with locking ends such that they will slide into T-slot 5 and spring open, causing their locking ends to be secured in the narrow sections of T-slot 5 . The T-straps 17 are removable by squeezing both ends of the T-strap 17 toward the pipe 18 such that they disengage from T-slot 5 . In a preferred embodiment, T-strap 17 is made of stainless steel, but any flexible material that will spring back to shape can be used. Alternatively, the pipes 18 may be secured through the use of twisted wire, metal ties, or plastic cable ties (such as those manufactured under the TY-RAP brand) passed through T-slot 5 .
If the support is not tall enough, threaded rods 15 may be attached to top plate 1 , as depicted in FIG. 8 . The threaded rods 15 pass through holes 6 and can be secured at the bottom of top plate 1 with lock nuts. The threaded rods 15 may be directly attached to the object to be supported, or the object can be connected to horizontal strut channel 16 . Holes 6 may also be used directly with nuts and bolts to secure an object directly to top plate 1 .
As will be appreciated from FIG. 7 , a vertical strut channel 14 can be inserted through rectangular opening 8 in top plate 1 . The vertical strut channel 14 can support more weight than threaded rods 15 and allows the roof-top support to be used for supporting heavy objects. The vertical strut channel 14 is received through a central opening in base plate 2 and rests upon a metal washer 13 and metal slug 12 . Metal washer 13 allows the downward force of the vertical strut channel 14 and its load to be distributed through the base plate 2 .
As can be appreciated from FIG. 11 , by simultaneously utilizing the various configurations available on the support system, multiple items can be supported at different heights. For example, a pipe 18 , including those with a T-junction 19 , can be supported by the indentations 7 and 10 , while a horizontal strut channel 16 can be supported at a greater height by threaded rods 15 attached to holes 6 in top plate 1 . The vertical strut channel 14 can even be used if rectangular opening 8 is not obstructed.
In a preferred embodiment, the support system is constructed of carbon-loaded polyethylene. This material is strong and withstands extreme hot and cold temperatures and is also UV resistant, a quality not seen in previous supports. Furthermore, base plate 2 has indentations 7 and perforations 20 to allow rainwater to escape, thus preventing damage due to ice. The perforations 20 also allow small aggregate to enter into the base plate 2 . This advantage is not appreciated in the prior art supports where aggregate was pushed into the roof, causing damage.
The presently disclosed device allows for fast and simple setup and a larger variety of configuration options that minimize the number of supports required, all while ensuring against roof damage. Because of the versatility, installers do not need to bring a variety of supports to the roof. Once the roof-top support has been installed, maintenance is simple. The base plate 2 is simply rotated to increase or decrease the height of the support. A particularly advantageous feature of the claimed design is that the rotation is accomplished without having to disengage the supported objects from the top plate 1 or the mat 3 . Because the base plate 2 pivots upon metal slug 12 , base plate 2 can be turned without disturbing the mat 3 or the objects on the top plate 1 . As a result, damage to fragile objects that are being supported, such as older pipes, is less likely to occur.
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.
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 resorting 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.
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. | A multi-purpose universal support is disclosed that can be configured to support multiple pipes, pipe junctions, vertical strut channels, horizontal strut channels, and thread rods. The disclosed support system allows for quicker installation, easy height adjustments, and a fewer supports than previously known supports. | 5 |
This invention relates to an electric motor servo system and, more particularly, to such a servo system with a capacitive position sensor having an exceptionaly fast response characteristic.
BACKGROUND OF THE INVENTION
A typical electric motor servo system includes an electric motor, a shaft mounted transducer for encoding the motor shaft position or motor speed, and an amplifier for providing a motor drive signal as a function of the difference between actual motor position or speed as compared to desired position or speed. In the design of a servo system it is important to avoid sources of instability in the feed-back loop. One of the more critical instability problems, which is often the limiting factor in the design, results from the torsional compliance which causes a lag between the transducer indication and the true rotor speed or position.
Normally the system designer tries to maintain the servo operation in a range below the mechanical resonance by a factor of 10 or more. For example, in a system including a two inch diameter, 0.1 inch thick, glass disk encoder and a 0.25 inch diameter by two inches long steel shaft coupling the encoder to the rotor, the expected torsional first resonance is about 1200 Hertz. Assuming a design factor of 10, the upper response frequency limit, i.e., the highest frequency of an applied signal which the servo system will reliably follow, would be about 120 Hertz. If the encoder disk is enlarged to a three inch diameter for greater accuracy, the response frequency for the system drops to below 60 Hertz. By increasing the shaft diameter to 0.5 inches to provide a stiffer coupling the response frequency limit could be increased to about 500 Hertz. From these examples it can be seen that the torsional compliance between the rotor and the encoder is often a critical factor in limiting the frequency response of a typical servo system.
An object of this invention is to provide a servo motor system wherein torsional compliance is virtually eliminated as a constraint to the frequency response in a fast response servo system.
Another object is to provide a fast response servo system which is more compact.
SUMMARY OF THE INVENTION
The servo motor system in accordance with this invention includes a position transducer or sensor located within the motor air gap. Preferably, the stator portion of the position transducer is attached to the inner surface of the stator core and the moving portion of the position transducer is attached surrounding the rotor. By locating the transducer elements within the air gap directly attached to the rotor and stator elements of the motor there is virtually no mechanical compliance between the rotor and transducer and, hence, the mechanical compliance is virtually eliminated as a contraint in the frequency response of the system design.
Normally, it is not possible to place a transducer in the air gap of an electric motor due to the geometry of the transducer and/or due to the interaction with the magnetic field of the motor. It has been found, however, that a capacitive position transducer can be designed to fit in the motor gap without materially increasing the size of the air gap. More importantly it has also been found that a capacitive position transducer can be designed so that it is insensitive to the magnetic field of the motor and so that the transducer has no significant detrimental effect upon the motor.
With the transducer elements attached directly to the rotor and stator elements of the motor, the servo loop approaches the ultimate in mechanical stiffness and, hence, the mechanical time constant in the servo loop is not a limiting constraint. The inductive time constant of the servo loop can generally be reduced as desired by operating at higher voltages. As a result, the response frequency of the servo system can be increased substantially over what could previously be achieved in a practical servo system with comparable components and is substantially limited only by the power transfer capability of the motor and the maximum speed of the motor.
BRIEF DESCRIPTION OF THE DRAWINGS
FIG. 1 is an illustration of a motor and position transducer combination in accordance with the invention together with a block diagram illustrating the servo loop.
FIG. 2 is a detail of the air gap portion of the motor illustrated in FIG. 1 showing the location of the transducer elements.
FIG. 3 is an illustration showing the conductor patterns of the rotor and stator portions of the transducer together with circuits for producing rotor position data.
FIG. 4 is an illustration showing various wave forms appearing in the system shown in FIG. 3.
FIG. 5 illustrates a system in accordance with another embodiment of the invention including both a coarse and a fine position transducer.
FIG. 6 is an illustration of the rotor and stator transducer patterns for the system of FIG. 5 and the associated circuits for providing rotor position data.
DETAILED DESCRIPTION OF THE INVENTION
The electric motor in the system according to the invention can be of any known type wherein an air gap exists sufficient to accommodate a capacitive type position transducer. As shown in FIG. 1, the motor may be of the brushless synchronous type with a rotor 10 including a ring 12 of permanent magnet material. The permanent magnet ring is magnetized to provide alternating north and south poles on the outer circumference of the ring. The permanent magnet ring can be formed by a plurality of successive alnico magnets or can be made of ceramic magnetic material like ferric oxide magnetized to provide the desired magnetic poles. Preferably, however, for high performance motors the magnet material is a samarium-cobalt composition which is magnetized to provide the desired magnetic poles. The magnet ring is suitably mounted for rotation on a motor shaft 14.
The stator portion of the motor includes a cylindrical laminated iron core structure with slots extending radially outwardly from the air gap. The windings for the motor are placed in the stator slots and can be in the form of a conventional three-phase Wye configuration. As will be explained hereinafter, energization of the windings through the commutation circuitry provides a rotating magnetic field.
As is best seen in the detail provided in FIG. 2, the position transducer is located in the air gap of the motor. The stationary portion of the transducer includes a series of capacitive plates formed by a printed circuit pattern 23 on a thin substrate 22. This printed circuit pattern is secured to the inner circumference of the stator core 18. Preferably the printed circuit pattern also includes a ground plane conductor pattern 24 on the reverse side of the substrate. The moving portion of the position transducer likewise includes a series of capacitive plates which are formed by a printed circuit pattern 27 on the surface of substrate 26. The reverse side of substrate 26 preferably also includes a conductor pattern 28 forming a ground plane. The moving conductor pattern is secured surrounding permanent magnet ring 12 of the rotor.
The moving transducer conductor pattern 27 is shown in the upper portion of FIG. 3 and includes two capacitive plates 30 and 34. Plate 30 is integral with a longitudinal strip 32 running the length of the pattern and plate 34 is similarly integral with a strip 36. The length of the pattern corresponds to the circumference of rotor permanent magnet ring 12 so that when the pattern is mounted strips 32 and 36 form conductive rings surrounding the rotor. Capacitive plates 30 and 34 each cover a 90 degree arc section of the rotor circumference. To minimize eddy current losses plates 30 and 34 are preferably in the form of comb-like patterns (shown in detail 42) where circumferentially extending fingers 37-40 are joined to strip 32 at one end by conductor 41.
The stationary conductor pattern for the transducer includes strips 50 and 52 which are aligned with strips 32 and 36, respectively, of the rotor pattern. Accordingly, when the stationary pattern is mounted on the inner circumference of the stator, strips 50 and 52 form stationary rings for coupling energy to the moving plates 30 and 34 via the rings formed by strips 32 and 36.
The stationary portion of the transducer also includes a pair of capacitive plates 54 and 56 which are aligned with plates 30 and 34 to provide a modulated sine wave output. Furthermore, the stationary pattern includes a second set of capacitive plates 60 and 62 which occupy the arcuate positions between plates 54 and 56 to provide a modulated cosine output. Thus, plate 54 occupies 0-90 degrees of arc, plate 60 occupies 90-180 degrees of arc, plate 56 occupies 180-270 degrees of arc and plate 62 occupies 270-360 degrees of arc. Plates 54, 56, 60 and 62 are shown each occupying approximately half the width of the transducer to provide the best signal separation but could be wider provided the separate plate identities are maintained. To reduce eddy current losses the plates can be formed in comb-like configurations as shown in detail 66 such that, for example, plate 56 is formed by strips 57 and 58 joined at the end not shown and plate 60 is formed by strips 63 and 64 joined at one end as shown. Strips 57 and 58 are aligned with strips 37 and 38 of the rotor pattern and strips 63 and 64 are aligned with strips 39 and 40.
Leads from the various sections of the stator conductor pattern can be brought out by any suitable means such as by through-hole connections to conductors on the opposite side of the substrate.
Ground planes 24 and 28 (FIG. 2) on the reverse side of the substrates are desirable for reducing noise in the transducer output signals. The ground planes are preferably formed by circumferential strips joined by a single transverse conductor to thereby avoid unnecessary eddy current losses.
The transducer is energized by an oscillator 70 preferably operating at about 100 Kilohertz. The oscillator is coupled to strips 50 and 52 via an amplitude control unit 72. Energy from the oscillator is coupled from strips 50 and 52 to strips 32 and 36 for energizing moving plates 30 and 34. In this manner the moving plates are energized without requiring brushes or slip rings.
The coupling of energy from the moving pattern to the stationary pattern to develop the position indicia is as illustrated in FIG. 4. If the rotor and stator patterns are aligned as shown in FIG. 3 (referred to as the zero position) there is a maximum coupling of signal to plates 54 and 56 to provide a sine signal of maximum amplitude. If the rotor moves 90 degrees the plates are misaligned so that there is a minimum coupling of energy. At 180 degrees coupling of energy is again maximum but of reverse polarity. At 270 degrees the coupled energy is again minimal. Thus, 360 degrees of rotor movement produces one cycle of the modulated sine wave shown in the upper trace in FIG. 4.
Plates 60 and 62 are displaced by 90 degrees relative to plates 54 and 56 and, therefore, they provide a similar modulated wave shape but it is displaced by 90 degrees, i.e., the cosine wave shown in the second trace from the top of FIG. 4.
Plates 54 and 56 are connected to a sine demodulator circuit 74 to demodulate the sine wave and recover the envelope shown in the third trace of FIG. 4. Similarly, plates 60 and 62 are connected to a cosine demodulator circuit 76 to demodulate the cosine wave and recover the envelope shown in the bottom trace of FIG. 4.
The outputs from demodulators 74 and 76 are supplied to automatic gain control (AGC) circuit 78 which computes the value of sin 2 X+cos 2 X using analog computing elements. Since the sum of sin 2 X and cos 2 X is always unity regardless of rotor position, this sum is suitable for use in controlling the amplitude of the energizing signal from oscillator 70. The amplitude of the energizing signal is automatically adjusted via amplitude control circuit 72 to maintain the value of sin 2 X+cos 2 X at unity. The values of the demodulated signals can then be taken as representative of position.
The output of sine demodulator 74 is supplied to an analog to digital (A/D) converter 83 through an amplifier 81 and the output of cosine demodulator 76 is supplied to analog to digital (A/D) converter 82 through amplifier 80. The digital outputs from converters 82 and 83 are supplied as the address inputs to a read only memory (ROM) 86.
From FIG. 4 it can be seen that the values of the demodulated sine and cosine signals taken together provide a unique set of values for each angular position of the rotor. Memory 86 is programmed to contain a look-up table for converting the sine and cosine address values into angular rotor positions in digital form.
FIG. 1 shows the servo loop using the position data provided by ROM 86 previously referred to in FIG. 3.
The stator windings are energized by a commutation circuit 98 controlled by rotor position signals from Hall detectors displaced 60 electrical degrees from one another. The signals from the Hall sensors are used to control solid state switches connected to the windings. A suitable arrangement including six transistors in a switching bridge configuration is shown in application Ser. No. 282,796 filed July 13, 1981 entitled "Brushless Motor Controller ", incorporated herein by reference.
The position transducer circuits 90, previously described in FIG. 3, supply the position address data to ROM 86 which converts the data into angular position values. A digital comparator 92 receives the actual position data from ROM 86 and the desired position data from an input circuit 94 and calculates the difference or error. The difference is supplied to a pulse width modulator (PWM) circuit 99 to control the average energization level to the windings via the commutation circuit 98. In conventional servo loop fashion, the motor tends to move toward the desired position to eliminate the error signal.
With the position transducer shown in FIG. 3, the pitch of the pattern is equal to one revolution, i.e., it requires one complete revolution of the pattern before it begins to repeat. If care is taken to minimize noise in the system, such a transducer can provide accurate position data to 1/100th of the pitch. The patterns shown in FIG. 3 can thus potentially indicate angular positions to within 4 degrees. Noise sources that can adversely affect accuracy are closure errors resulting from differences between the circumference dimensions and the length of the transducer patterns, air gap variations between the moving and stationary transducer elements, skew of the transducer pattern and pattern defects. Noise is also generated by the motor itself, the circuit components and temperature drift.
Finer position indications can be achieved by reducing the pitch of the transducer pattern to a fraction of a revolution. The system is still capable of indicating position to 1/100th of the pitch and, hence, the finer pitch transducer pattern provides correspondingly finer position indications. It is important that the air gap between the transducer elements not exceed a few percent of the pitch distance. Thus, for a motor airgap in the range of 0.008 to 0.010 inches, the reasonable minimum pitch distance for the transducer would be about 0.100 inches. Printed circuit techniques are available for producing transducers with a pitch as fine as 10 mils, but 100 mils is a better practical limit for most motor designs. Such transducers can be made to customer specifications by Farrand Industries Inc of Walhalla, N.Y.
The disadvantage of transducers in the motor with a pitch at a fraction of a revolution is that, where absolute position indications are required, an additional position indicator must be added to the system to indicate the present position sector. For example, if the pattern has a pitch of 1/12th of a revolution, the pattern of the transducer repeats 12 times per revolution and position is indicated within twelve-30 degree segments. A suitable system for indicating the specific sector can be provided by including a marker position on the transducer to indicate a zero position indication. The marker position indication would be used in combination with a counter for counting zero crossings of the demodulated transducer outputs. In such an arrangement the counter provides a course position indication, i.e, a sector position, and the normal transducer output provides the fine position indication within the sector.
Another technique for providing fine position indications using capacitive transducers located within the motor airgap is illustrated in FIGS. 5 and 6 wherein the transducer pattern includes a coarse pattern having a pitch equal to one revolution and a fine pattern having pitch equal to 1/12 of a revolution.
The moving portion of the transducer pattern is shown in the upper part of FIG. 6 and includes 3 parallel strips 102-104 which form rings surrounding the rotor when the pattern is in place. Capacitive plates 106 and 107 each cover 90 degrees segments of the surface and are integral with strips 103 and 102, respectively. Plates 106 and 107 are equally spaced and form the moving portion of the course position transducer.
The fine portion of the position transducer includes capacitive plates 108 which are integral with strip 104 and plates 109 which are integral with strip 103. Plates 108 and 109, as shown, form an interleaved comb-like pattern which repeats 12 times and hence has a pitch of 1/12 of a revolution.
The stationary transducer pattern includes strips 112-114 which are aligned with strips 102-104, respectively, of the rotating pattern. When in place inside the motor core, strips 112-114 form rings for coupling energy to the moving pattern.
The stationary pattern also includes plates 116 and 117 aligned with plates 106 and 107 for generating the sine signal and plates 118 and 119 interleaved therewith to provide the cosine signal. Plates 116-119 together with plates 106 and 107 form the coarse portion of the transducer which is similar to that previously described in FIG. 3.
The stationary pattern further includes interleaved comb-like patterns 120 and 121 aligned with the moving pattern formed by plates 108 and 109. Patterns 120-121 and 108-109 form the fine position portion of the transducer.
The transducer is energized from an alternating current source 130 via an amplitude control circuit 132. An alternating signal is applied to strips 113 and 114 for coupling energy to strips 103 and 104 of the moving pattern to energize plates 108 and 109. Similarly, energy is applied between strips 112 and 113 from where it is coupled to strips 102 and 103 to energize plates 106 and 107 of moving pattern.
Plates 116 and 117 are connected to a coarse sine demodulator circuit 137 and plates 118 and 119 are connected to a course cosine demodulators circuit 136. The outputs from modulator circuits 136-137 are coupled to an automatic gain control (AGC) circuit 140 which calculates the value of sin 2 X+cos 2 X. The automatic gain control circuit is connected to amplitude control circuit 132 to control amplitude of the energization signal supplied to the transducer in the manner previously described in connection with FIG. 3.
Patterns 120 and 121 are connected to a fine signal demodulator circuit 140 which decodes the modulated signal from the fine position portion of the transducer. The output of demodulator 140 is a sine wave including 12 cycles per motor revolution.
The outputs from demodulator circuits 136-138 are supplied to analog to digital (A/D) converters 146-148 via amplifiers 142-144 respectively. The digital outputs from the converter circuits are supplied as address inputs to a read only memory (ROM) 150. The ROM can be a conventional memory unit with a 16 bit addressing capability, 8 bits from A/D converter 148 indicating the fine position and 4 bits from each of the A/D converters, 146 and 147 indicating the course position sector. The combination of the outputs from A/D converters 146-148 provides a unique address for each position of the transducer.
A servo loop system including the position data as provided in FIG. 6 is illustrated in block diagram form in FIG. 5. Components 136, 137, 142, 143, 146 and 147 form the course position transducer circuits 160 and components 138, 144, and 148 form the fine position transducer circuit 162. Circuits 160 and 162 provide the previously discussed address inputs for ROM 150.
Since the output of ROM 150 provides a rotor position indication, this output can be used directly to control commutation thereby eliminating the need for Hall sensors or the like. Details on the use of a ROM output to control commutation in a brushless DC motor is more fully described in application Ser. No. 282,796 previously referred to herein.
A comparator circuit 168 is used to compare the actual position indication, as provided by the output of ROM 150, and the desired position indication, as provided by an input circuit 166. The output of comparator 168 is supplied to a pulse width modulation (PWM) circuit 170 which in turn controls the average amplitude of the winding energization signal furnished through commutation circuit 190. The system operates in conventional servo loop fashion where the motor is energized in a direction moving toward the desired position to thereby eliminate the error signal produced by comparator 168.
While only a few illustrative embodiments have been described in detail it should be apparent that there are numerous other variations within the scope of this invention. The invention is more particularly defined in the appended claims. | A servo motor system including a position sensor located within the motor air gap to virtually eliminate mechanical compliance in the servo loop. The transducer is of a capacitive type including interleaved capacitive plates and is designed to be substantially insensitive to the magnetic field of the motor. | 7 |
CROSS-REFERENCE TO RELATED APPLICATIONS
[0001] This application claims the benefit of priority to U.S. Provisional Application No. 61/681,355 filed on Aug. 9, 2012.
BACKGROUND OF THE INVENTION
[0002] 1. Field of the Invention
[0003] The invention relates generally to the field of metal buildings. More specifically, the invention relates to the field of insulating a building and maintaining a vapor barrier in a wall of the building.
[0004] 2. Description of the Related Art
[0005] Walls are typically supported horizontally by girts attached to columns constituting bays within the building structure. Typically the girts attach into the sides of the columns with the column located near the wall/girt attachment line. This method causes the typical wall insulation and vapor retarder to terminate into the side of the column. With various webs, flanges and stiffeners needed at the column it makes it very difficult to fully insulate and utilize a continuous vapor retarder. Also, by locating the column near the wall line the insulation is usually compressed significantly minimizing the thermal performance of the wall system.
SUMMARY
[0006] A typical pre-engineered building wall consists of an outer exposed surface (wall panel), then insulation (blanket or board), and then a vapor retarder (on the interior, conditioned, side of the wall) which can consist of insulation facing, flexible membrane, metal liner (or panels) or other hard interior wall substrates with a good perm rating to minimize water vapor from migrating through it. The problem with the vapor retarder is where it joins up at locations where the building structure causes a break in the continuation of the barrier. This joint must be as tight as the vapor retarder material to maintain the continuation of the barrier. The disclosed technology provides a method to easily seal the joints of the vapor retarder at the structural column lines.
[0007] The disclosed technology installs the girts outside of the column line and eliminates this issue of compressing the insulation. Also, a trim piece is installed on the outside flange of the column to provide a surface to seal the vapor retarder from one side of the column to the other side. This trim extends the full height of the column to make contact with the roof vapor retarder therefore providing an integral roof vapor retarder.
[0008] It is critically important to maintain a continuous vapor retarder in the wall construction of a pre-engineered building and to have it tie to the roof vapor retarder so a continuous, monolithic vapor retarder occurs between the roof and wall. Without this monolithic, continuous vapor retarder, anywhere there is a void condensation or moisture can occur due to the relative humidity of the interior air reaching a surface that is at the dew point temperature. By maintaining a barrier, that is insulated to keep its temperature higher than the dew point temperature, condensation and moisture will avoided.
[0009] The typical wall and structural construction of a pre-engineered metal building creates numerous challenges that make it difficult to maintain a continuous vapor retarder throughout the wall and then tie it to the vapor retarder in the roof plane. The disclosed system, method and kit eliminates one of the major obstacles at each structural column line. The disclosed technology also provides for an area where economical blanket insulation can be installed in significant thickness with numerous exterior and interior wall configurations to make it very versatile for all kinds of wall systems. The purpose is to provide the high “R-value” wall system with a very good vapor retarder solution, and to provide this in a very easy to install method for the installer of the wall.
BRIEF DESCRIPTION OF THE SEVERAL VIEWS OF THE DRAWINGS
[0010] Illustrative embodiments of the present invention are described in detail below with reference to the attached drawing figures, which are incorporated by reference herein and wherein:
[0011] FIG. 1 is a side view of the system 100 in assembled form;
[0012] FIG. 2 is an exploded view enabling many of the features to be seen as they exist before assembly;
[0013] FIG. 3 shows a horizontal section taken at a 3 - 3 in FIG. 1 ;
[0014] FIG. 4 is a perspective view showing the environment in which the wall system is used;
[0015] FIG. 5 is sectional view of a wall and roof of a pre-engineered building with insulation installed revealing outside and inside conditioned, i.e., heated or cooled, air; and
[0016] FIG. 6 is a sectional view of a column showing compressed insulation proximate the column flange.
DETAILED DESCRIPTION
[0017] Before describing the instant invention in detail, several terms used in the context of the disclosed technology will be defined. In addition to these terms, others may be defined elsewhere in the specification, as necessary. Unless otherwise expressly defined herein, terms of art used in this specification will have their art-recognized meanings.
[0018] Girt: a horizontal structural member in a framed wall that provides lateral support to the wall panel, primarily, to resist winds loads.
[0019] Wall line: the outermost perimeter of the wall of a building.
[0020] Perm rating: a measure of the diffusion of water through a material.
[0021] Vapor retarder: a vapor retarder is defined by ASTM Standard C 755 as a material or system that adequately retards the transmission of water vapor under specified conditions.
[0022] Embodiments of the disclosed technology provide a system, a kit and a method for establishing an insulated wall for a building.
[0023] Embodiments of the disclosed invention are shown in FIGS. 1-4 . FIG. 5 reveals a sectional view of a pre-engineered building wall and roof detailing the installation of insulation. FIG. 6 is a column sectional view, consistent with that shown in FIG. 3 , except that this figure details how the insulation is typically compressed between the column flange and the exterior wall panel 106 thereby reducing the capacity of the insulation to retard heat transfer. FIG. 1 shows an embodiment for a system 100 in assembled form. FIG. 2 is an exploded view enabling many of the features to be seen as they exist before assembly. FIG. 3 shows a horizontal section taken at a 3 - 3 in FIG. 1 , and discloses the roof/column interface of the system in more detail. FIG. 4 shows the environment in which the wall system is used.
[0024] Referring to FIGS. 1 and 2 , it can be seen that the system is mounted on to a typical metal column 102 and beam 104 arrangement which exists at a location where the wall and roof meet. In the environment of a typical building, FIG. 4 shows where the column 102 , beams 104 , and girts 118 might appear. Referring back to FIGS. 1 and 2 , it can be seen that a wall panel 106 is ultimately secured onto the outside of the building. In the embodiments disclosed, this panel 106 is metal, but could be constructed of other materials.
[0025] Also used to construct the system are a plurality of horizontally extending spacer blocks 108 . The spacer blocks 108 are typically made from a foam board insulation product. Blocks 108 are fastened onto the girts 118 over a blanket sheet of insulation 110 . Insulation blanket 110 might be constructed of a fiberglass insulation, but might be comprised of another sort of insulating material.
[0026] Also included in the system are top 111 , upper 112 , mid 113 , and lower 114 batts of insulation. The batts, in the preferred embodiment, are made of faced or unfaced commercially available fiberglass insulation material. But other insulating materials could be used instead.
[0027] Top batt 111 is contained within a pair of opposed metal C-members 115 . Below that, the upper batt 112 rests above one of the girts 118 . Below that, the slightly larger mid batt 113 is located above another girt 118 . Then below that, the lower batt 114 rests atop an upwardly facing receiving bracket 120 .
[0028] Referring to FIGS. 2 and 3 , a trim piece 122 is used to secure a vapor barrier 128 on the inside of the building and along with vapor barrier 128 , is used to create a seal. In an embodiment, piece 122 is constructed of metal, but it could be made of other materials. Vapor barrier 128 , is shown as having different embodiments. For example, in the disclosed FIGS. 1-3 , the liner is seen as being a corrugated metal liner. But it could instead consist of insulation facing, a flexible membrane, metal panels or other hard interior wall substrates with a good perm rating to minimize water vapor from migrating through it. Regardless, in the disclosed embodiments, the liner is fasted to the trim piece to complete the seal.
[0029] The installation, in embodiments, occurs according to the following process.
[0030] First, the column 102 and beam 104 are erected according to known processes. Then, the trim piece 122 is held up in line with and thus overlapping the outer flange 103 of the column 102 . With the trim piece 122 as thus, the external hardware, more specifically, the opposing C-members 115 , bracket 116 , girts 118 , and receiving bracket 120 are all installed in the positions and orientations shown. Each piece of hardware is secured using fasteners. In the disclosed embodiment the hardware is pre-punched or drilled so that it can accept bolts. Of course, other fastener arrangements could be used. The fasteners pass through the trim piece 122 (which can also be pre-punched) and then through predrilled holes into either the outer flange 103 of column 102 (for the girts 118 and receiving bracket 120 ) or the outer flange of the beam 104 (for the upper bracket 116 ). Nuts can be used to complete the securing of the bolts. Thus, the trim piece 122 is secured between the external hardware and outer flange of the column. Outer margins 126 of the trim piece will extend wider than the flanges (e.g., flange 103 of column 102 as seen in FIG. 3 ; also the outer flange of the beam 104 ), there being useful for receiving the vapor liner 128 . A flat center portion 124 of the trim piece 122 is in contact with the outer flange 103 of the column 102 after being sandwiched by the exterior hardware (e.g., girts 118 and receiving bracket 120 ) upon fastening. A small upper portion of the trim piece 122 extends into the space created by purlins (e.g., purlin 130 ) between the top of the beam 104 and an upper roof structure 132 .
[0031] Now, with the outer hardware being fastened into place, vapor barrier sheets 128 are installed by adhering them to the exposed outer margins 126 (see FIG. 3 ) of the trim piece 122 using an adhesive, double sided tape, or fasteners.
[0032] Next the batts of insulation 111 , 112 , 113 , and 114 are installed. Batt 111 is installed by pressing it between the opposing C-members 115 . Alternatively, it could be installed before that after the first outward facing C-member is fastened onto the bracket 116 . Then the outer C-member could be installed into the open C of the outwardly facing C-member, and the outer C-member then fastened into place thus containing the insulation batt 111 .
[0033] The remaining three batts are installed from outside the building. More specifically, batt 112 is placed between the upper bracket 116 , and the girt 118 right below it. Some batts include adhesive pin tabs about their periphery. This enables them to remain in place after being located in the space desired. Similarly, batt 113 is secured into place underneath the top girt and the girt immediately below it, and pinned. The lower batt 114 is pinned into place between the lower girt, and the receiving bracket 120 .
[0034] It should be noted that FIG. 3 shows only a single homogenous form 114 a of insulation. This figure, in embodiments, would include the same insulation features (e.g., a blanket and batt), but does not depict these features for simplicity sake. Alternatively, however, the trim piece 122 and vapor barrier features could be used with the single type insulation embodiments like the one shown in FIG. 3 . Regardless, it should be understood that the trim piece/vapor barrier arrangement could work equally well with numerous insulation arrangements.
[0035] Now with the internals being secured in place, the blanket of insulation 110 is draped over the outside of the frame, normally by tacking it up at the top somewhere (e.g., near the C-members 115 ), so that it extends all the way down to the ground. The blanket insulation 110 , which comes in rolls, can be premeasured and precut to size, or cut at the ground after it has been unfurled.
[0036] In the disclosed embodiment, the spacer blocks 108 are adhered to the inside surfaces of the exterior wall panel 106 in the appropriate orientations before the panel is installed. Then, the wall panel 106 is raised into position and mounted. This is done by installing fasteners (through pre-punched holes in the outside of the panel) through the blocks 108 (also pre-punched) and through predrilled holes existing in the outer hardware. For example, at the top of the assembly, bolts will be slid through the panel, through the holes through the respective spacer block, through the outside C-member 115 , and nuts will be secured thereon. Below that, bolts will be slid through the wall panel, blocks, through predrilled holes in the outer flanges of the girts 118 , and nuts will be secured thereon. Then, a last group of bolts will pass through holes in the panel and block, through the outer flange of the receiving bracket 120 , and nuts secured thereon.
[0037] It should be noted that alternative assembly of the components could be made. For example, after the installation of the hardware components 115 , 116 , 118 , and 120 , but before the installation of the liner 128 and batt insulation components 112 , 113 , and 114 , the blanket insulation 110 could be tacked and the wall panel 106 with blocks 108 could be installed thereover. Then, the batts 112 , 113 , and 114 could be installed from the inside of the building, and the vapor barrier liner 128 adhered to the trim flanges 126 .
[0038] Many different arrangements of the various components depicted, as well as components not shown, are possible without departing from the spirit and scope of the present invention. Embodiments of the present invention have been described with the intent to be illustrative rather than restrictive. Alternative embodiments will become apparent to those skilled in the art that do not depart from its scope. A skilled artisan may develop alternative means of implementing the aforementioned improvements without departing from the scope of the present invention.
[0039] It will be understood that certain features and sub-combinations are of utility and may be employed without reference to other features and sub-combinations and are contemplated within the scope of the claims. Not all steps listed in the various figures need be carried out in the specific order described. | A system for assembling a pre-engineered building with a monolithic vapor retarder to control the formation of condensation on the walls. The system allows for numerous different combinations of insulation thickness, different kinds of walls, inside vapor retarders in different rigid panels, different facings or membranes. The system further provides for finished inside surfaces with high thermal quality. | 4 |
BACKGROUND OF THE INVENTION
The present invention relates to a video signal processing apparatus for digitally enhancing the contours of a video signal and is especially useful in a television camera.
In a color television (or video) camera, one or more camera pickup devices, such as a camera tube or a charge-coupled device (CCD), converts light from an image into three video signals. Typically, the three video signals are initially analog signals representing the red, green, and blue components, collectively "RGB," of the light that forms an image. In modern camera systems, each of the video signals is subjected to a variety of signal processing operations to compensate for inherent characteristics of the system and of the methodology for producing the video signal. For example, such signal processing may include dynamic color shading, knee processing, static color shading, and gamma correction.
Certain video cameras incorporate a device for enhancing the contours of the image represented by the color video signals. Here the term "contour" is used to refer to the boundaries between colored areas in an image. Without contour enhancement, the image reproduced from a particular set of color video signals tends to have blurred contours. Often, such blurring is noticeable to a viewer and is perceived as poor image quality. To prevent such image deterioration, video signals are subjected to a contour enhancement process.
Both analog and digital contour enhancement circuitry have been developed utilizing somewhat analogous signal processing techniques. In the digital contour enhancement circuit each of the three (red, green, blue) analog color signals is converted into a respective digital signal. The digital red, green, and blue signals are weighted, e.g. multiplied by a particular factor, and summed to produce a luminance signal. The luminance signal is subjected to certain delay amounts to produce a number of delayed signals. Lastly, a detail signal is generated by combining the luminance signal with the delay signals by means of addition and subtraction operations. The resulting detail signal varies in pulse form across the contours (edges) of the luminance signal.
Unfortunately, the detail signal thus produced accentuates both distinct and blurred contours in the original image. Addition of this detail signal to the digital color signals enhances the blurred contours but overenhances the distinct contours resulting in image deterioration. To remedy this shortcoming, circuitry has been developed to clip the peak levels of the detail signal to a certain level to lessen the accentuation of already distinct contours By adding the clipped detail signal to the digital color signals, the blurred contours of the image represented by the color signals, and to a lesser extent the already distinct contours of that image, are enhanced. The resulting image is perceived to display an overall improvement in resolution.
Nonetheless, the clipping process still results in the overenhancement of distinct contours of the original image and tends to introduce other errors into the color signals. This overenhancement often appears as unnaturally wide contours in the reproduced image. Additionally, this phenomena, compounded by the conversion of the digital signals to an analog form, may appear in the reproduced image as areas of substantial distortion caused by false signals and overshoot. The clipping process, being severely nonlinear, creates higher harmonics in the detail signal which are distributed within the bandwidth of the color signals upon digital-to-analog signal conversion. These higher harmonics can be perceived in the reproduced image as image deterioration.
OBJECTS AND SUMMARY OF THE INVENTION
An object of the present invention is to provide apparatus for producing a contour enhancement signal that enhances the contours of a video signal without overenhancing already fine contours.
Another object of the present invention is to provide apparatus for producing a contour enhancement signal that enhances the contours of a video signal without introducing noise into the video signal which substantially affects the quality of the image represented by the video signal.
More specifically, it is an object of the present invention to prevent signal deterioration caused by contour enhancement which is characteristic of digital contour enhancement circuits utilizing a clipping circuit to limit the detail signal.
A still further object of the present invention is to provide apparatus for producing a contour enhancement signal that is limited between two predetermined levels without overshoot.
In accordance with an aspect of the present invention, a digital processing apparatus for correcting an image enhancement signal having a shape is provided which includes a peak detector for detecting and holding the peak levels of the image enhancement signal and an adjustment device, responsive to the peak levels, for correcting the image enhancement signal to reduce its peak levels while substantially maintaining its shape.
In accordance with another aspect of the present invention, a digital processing apparatus for correcting an image enhancement signal having a shape is provided which includes an envelope detector for detecting the envelope of the image enhancement signal and an adjustment device, responsive to the envelope, for correcting the image enhancement signal to reduce its peak levels while substantially maintaining its shape.
In accordance with yet another aspect of the present invention, a digital processing apparatus for generating a contour enhancement signal for a video signal is provided which includes a generating device for generating a contour signal representative of a contour represented by the video signal and a correction device for correcting the contour signal to prevent substantial overenhancement of a fine contour represented by the video signal.
Other objects, features, and advantages according to the present invention will become apparent from the following detailed description of illustrated embodiments when read in conjunction with the accompanying drawings in which the same components are identified by the same reference numerals.
BRIEF DESCRIPTION OF THE DRAWINGS
FIG. 1 is a block diagram of a video camera incorporating a contour enhancement circuit according to an embodiment of the present invention;
FIG. 2 is a block diagram of a contour enhancement circuit according to an embodiment of the present invention;
FIG. 3A and 3B are signal diagrams to which reference will be made in describing the operation of the contour enhancement circuit of FIG. 2;
FIGS. 4A and 4B are signal diagrams to which reference will be made in describing the operation of the contour enhancement circuit of FIG. 2;
FIGS. 5A and 5B are signal diagrams to which reference will be made in describing the operation of the contour enhancement circuit of FIG. 2; and
FIGS. 6A and 6B are signal diagrams to which reference will be made in describing the operation of a contour enhancement circuit incorporating a clipping circuit.
DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS
FIG. 1 illustrates a television camera system, indicated generally at 11, incorporating a contour enhancement circuit according to an embodiment of the present invention. Television camera system 11 is comprised of a lens system 12; image pickup devices 13R, 13G, and 13B; analog signal processors 14R, 14G, and 14B; analog-to-digital (A/D) converters 15R, 15G, and 15B; contour enhancement circuit 16; digital signal processors 17R, 17G, and 17B; encoder 18; digital-to-analog (D/A) converter 19, and lowpass filter 20. Preferably, the television camera system is contained in a single housing.
Lens system 12 is a conventional device, such as a lens followed by a dichroic mirror array, for acquiring an image and splitting light from the image into its basic components. Preferably, light from an acquired image is divided into its constituent red light (RL), green light (GL), and blue light (BL) components. Each of the three colored lights is focused upon a respective image pickup device 13R, 13G, and 13B. Preferably, the image pickup devices are solid-state charge-coupled devices (CCD). Each image pickup device generates an image signal representative of the light incident thereupon and supplies the image signal to a respective analog signal processor 14R, 14G, and 14B.
The analog signal processors 14R, 14G, and 14B convert the image signals into color signals and apply correction processes, such as shading correction, to correct the signals. The corrected red color signal is supplied to A/D 15R, the corrected green color signal is supplied to A/D 15G, and the corrected blue color signal is supplied to A/D 15B. Each A/D converter converts a respective analog color signal into a corresponding digital color signal, one of DR, DG, and DB. All three color signals are supplied to contour enhancement circuit 16.
Contour enhancement circuit 16 generates a detail signal representing the contours of the image represented by signals DR, DG, and DB. The detail signal is added to each of the digital color signals to enhance the contours represented by each. The contour enhanced signals DR1, DG1 and DB1, corresponding to signals DR, DG, and DB, respectively, are supplied to digital signal processors 17R, 17G, and 17B, respectively. A more detailed discussion of the preferred construction and operation of a contour enhancement circuit according to the present invention will be presented in connection with FIG. 2.
Digital signal processors 17R, 17G, and 17B process the signals DR1, DG1, and DB1, respectively, to adjust and further correct these signals for transmission and/or display. Such adjustment and correction processes may include, for example, gamma correction and knee processing. The processed digital color signals are supplied to encoder 18. Encoder 18 weights and combines the processed digital color signals to produce a digital luminance signal and digital color difference signals which are converted into analog forms by D/A converter 19. The analog luminance and color difference signals are low-pass filtered by filter 20 to limit their bandwidths, and the filtered signals thus produced comprise an output video signal SV.
FIG. 2 illustrates a preferred embodiment of the contour enhancement circuit 16 described briefly above. The contour enhancement circuit 16 is comprised of a detail signal generator 22; adders 23R, 23G, and 23B; and detail signal correction circuit 24. As described above, the contour enhancement circuit receives three digital color signals DR, DG, and DB, generates a detail signal DTL1, and adds the detail signal DTL1 to each digital color signal to produce contour enhanced signals DR1, DG1, and DB1, respectively.
Specifically, detail signal generator 22 receives each digital color signal DR, DG, and DB; adder 23R receives signal DR, adder 23G receives signal DG, and adder 23B receives signal DB. The detail signal generator generates a luminance signal by weighting and combining the digital color signals DR, DG, and DB. The luminance signal is delayed in the horizontal direction by two predetermined amounts of time to obtain two horizontally delayed versions of the luminance signal. The original luminance signal is combined, preferably in a linear manner, with the two horizontally delayed versions of the luminance signal to produce a horizontal contour signal representing the horizontal contours of the luminance signal.
The luminance signal is also delayed in the vertical direction by two predetermined amounts of time to obtain two vertically delayed versions of the luminance signal. The original luminance signal is combined, preferably in a linear manner, with the two vertically delayed versions of the luminance signal to produce a vertical contour signal representing the vertical contours of the luminance signal. The horizontal contour signal and the vertical contour signal are combined to produce detail signal DTL which is supplied to detail signal correction circuit 24.
As will be appreciated by one of ordinary skill, the present invention is not limited to any particular method of generating contour signals or a detail signal DTL since a variety of methods for generating such signals exist. Similarly, the following description of the correction of a luminance-based detail signal can be adapted to other types of detail signals or other correction signals and such adaptation clearly falls within the scope of the present invention. Accordingly, the luminance signal described herein is intended to facilitate clear explanation of the present invention and is not intended as a limit thereupon.
Detail signal correction circuit 24 is comprised of interpolator 30, absolute value forming circuit 33, polarity detector 31, peak-hold circuit 34, decimator 35, limiting circuit 36, gain setting circuit 32, and amplifier 25. The detail signal correction circuit processes detail signal DTL to limit the positive and negative peak levels of the signal to specified values while minimizing the introduction of errors into the corrected signal.
Detail signal DTL is supplied to interpolator 30 for interpolation, also referred to as "upsampling" or "upconverting." Preferably, interpolater 30 is comprised of a digital filter circuit which interpolates the sampling of detail signal DTL to produce a detail signal DTL INT with twice the sampling frequency of signal DTL. Detail signal DTL INT is supplied to absolute value forming circuit 33 which produces an absolute value signal representing the absolute value of detail signal DTL INT . The absolute value signal is supplied to peak-hold circuit 34.
Polarity detector 31 also receives detail signal DTL and detects the polarity of the signal. The detected polarity is supplied to peak-hold circuit 34 and to limiting circuit 36 in the form of a polarity signal.
Peak-hold circuit 34 tracks and holds the peak values of the absolute value signal to produce a peak signal. The peak values are held for a fixed interval which corresponds to a feature of signal DTL. Preferably, the time constant of peak-hold circuit 34 corresponds to the rising and falling time period of the signal level of detail signal DTL. In this manner, peak-hold circuit 34 functions as an envelope detector to smooth the absolute value signal. The envelope of the interpolated detail signal DTL INT is more easily and accurately detected than the original detail signal DTL because DTL INT has a higher sampling frequency. Without upsampling, the envelope detector is prone to erroneous detection caused by frequency beat components that can occur when the frequency of the input signal is near the frequency of an integral submultiple of the sampling frequency.
Circuit 34 also receives the polarity signal and supplies both the peak signal and the corresponding polarity signal to decimator 35. Decimator 35, preferably comprised of a digital filter, interpolates and converts the peak signal to produce an interpolated peak signal L having the original sampling frequency of detail signal DTL.
Signal L, the polarity signal, a predetermined positive limit signal Lp, and a predetermined negative limit signal Ln are supplied to limiting circuit 36. When signal L corresponds to a positive value of detail signal DTL, as indicated by the polarity signal, that does not exceed the value Lp, limiting circuit 36 outputs the Lp signal. Similarly, when signal L corresponds to a negative value of detail signal DTL, as indicated by the polarity signal, that does not exceed the value Ln, limiting circuit 36 outputs the Ln signal. Otherwise, circuit 36 outputs signal L. The signal output by circuit 36 and the polarity signal are supplied to gain setting circuit 32.
If the polarity signal indicates that detail signal DTL is positive, then gain setting circuit 32 divides the quantity Lp by the value represented by the signal output from circuit 36 to produce a gain signal. If the polarity signal indicates that detail signal DTL is negative, then gain setting circuit 32 divides the quantity Ln by the value represented by the signal output from circuit 36 to produce the gain signal. The gain signal is supplied to amplifier 25 to set the gain of the amplifier. As illustrated in FIG. 3A, the gain G is set at unity for values of L between -Ln and Lp and at values of less than unity for values of L outside of this range. Outside the range, the gain generally decreases for increasingly positive or increasingly negative values of L.
Optionally, the gain setting circuit 32 smoothly varies the gain for predetermined periods of time immediately prior to and immediately after peak values of detail signal DTL are reached. Such variation further insures that corrected detail signal DTL1 maintains a constant level during peak value periods of detail signal DTL and that signal DTL1 is not improperly distorted as compared to detail signal DTL.
Amplifier 25 is a variable-gain amplifier for amplifying detail signal DTL according to the gain signal supplied by gain setting circuit 32 to produce a corrected detail signal DTL1. Preferably, amplifier 25 functions as a multiplying circuit to multiply detail signal DTL by the gain signal to produce signal DTL1. By varying the gain signal as described above, detail signal DTL is corrected such that the positive and negative peak levels of the resulting detail signal DTL1 do not exceed Lp and Ln, respectively. Optionally, amplifier 25 may additionally produce signal DTL1 as a smoothly varying signal. As another alternative, the gain signal may be lowpass filtered to produce a smooth detail correction signal.
FIG. 3B illustrates the general relationship between detail signal DTL and corrected detail signal DTL1. As shown, detail signal DTL1 can be approximately defined as:
DTL1=-Ln for DTL<=-Ln;
DTL1=DTL for -Ln<DTL<Lp; and
DTL1=Lp for DTL>=Lp.
Detail signal DTL1 is added to each of digital color signals DR, DG, and DB by adders 23R, 23G, and 23B, respectively, to produce, respectively, contour enhanced signals DR1, DG1, and DB1. By the foregoing means, the contours of the image represented by digital color signals DR, DG, and DB are enhanced.
As compared to clipping, amplifier 25 corrects detail signal DTL according to a signal limiting process which causes relatively fewer higher harmonics to appear in the corrected detail signal DTL1. correspondingly, the occurrence of false signals and overshoot in the corrected signal are effectively prevented and waveform distortion is reduced. Further, unnatural widening of the contour and deterioration of the image represented by the color signals are prevented.
Additionally, the values of limit signals Lp and Ln can be manipulated to adjust the amount of contour enhancement which is produced to complement other processing of the color signals. For example, Lp and Ln can be adjusted so that the contour enhancement is not distorted by a gamma correction process. Specifically, if Lp is set to an amount appropriately greater than Ln, then balanced amounts of contour enhancement will remain in the color signals following gamma correction thereof.
Tests of the contour enhancement circuit according to an embodiment of the present invention confirm its efficacy in preventing the unnatural widening of contours and the generation of false signals. The results of these tests are illustrated in FIGS. 4A and 5A which depict the output signal SV of the camera system upon input of a luminance signal having a single 10%-to-90% pulse into the contour enhancement circuit.
FIG. 4A illustrates the output signal SV produced when detail signal DTL is not corrected, that is, when the gain of amplifier 25 is set to unity. For such a case, FIG. 4B shows detail signal DTL1 , having values that clearly exceed the range -Ln to Lp, that was generated and used to enhance the contours in output signal SV. In contrast, FIG. 5A illustrates the output signal SV produced when detail signal DTL is corrected in accordance with the present invention and when Ln and Lp are set to the same value. As shown, output signal SV tracks the input signal closely. FIG. 5B shows the detail signal DTL1 that was generated and used to enhance the contours in output signal SV. This signal has the same general shape as the waveform of FIG. 4B but is limited to the range -Ln to Lp.
For the purposes of comparison, a contour enhancement circuit incorporating a clipping circuit, supplied with a single 10%-to-90% luminance pulse input signal, produced the output signal of FIG. 6A. In FIG. 6A, it is clear that signal SV does not follow the input signal as quickly as did the output signal produced by the contour enhancement circuitry of the present invention. Further, the clipping circuit produces a ringing effect bordering the edges of the output pulse which deteriorate the quality of the image represented thereby. The detail signal DTL2 produced by the clipping process is shown in FIG. 6B. Although clipping is performed at the clipping level CL, overshoot occurred, false signals were generated, and a widening of the resulting waveform was observed.
Although illustrative embodiments of the present invention and modifications thereof have been described in detail herein, it is to be understood that this invention is not limited to these precise embodiments and modifications, and that other modifications and variations may be affected therein by one skilled in the art without departing from the scope and spirit of the invention as defined by the appended claims. | Digital processing apparatus for correcting an image enhancement signal having a shape includes a peak detector for detecting and holding peak levels of the image enhancement signal and an adjustment circuit, responsive to the peak levels, for correcting the image enhancement signal to reduce its peak levels while substantially maintaining its shape and to limit the signal levels of the image enhancement signal to a range of levels substantially between a first predetermined peak limit and a second predetermined peak limit. | 7 |
BACKGROUND OF THE INVENTION
[0001] 1. Field of the Invention
[0002] This invention relates in general to a dispensing system for use in a heating, ventilating or air conditioning (HVAC) air stream and, in particular, to a central or zoned forced air HVAC media dispensing system for dispensing water vapor and/or other water soluble air-flow borne materials.
[0003] More specifically, but without restriction to the particular embodiment and/or use which is shown and described herein for purposes of illustration, this invention relates to a user-programmable central or zoned HVAC dispensing system for introducing various media such as water vapor, fragrances or other air-treating materials to improve living and working environments.
[0004] 2. Description of Related Technology
[0005] The use of a humidification device for a central or zoned forced air HVAC system to improve living and working environments is known to those skilled in this art. Such systems generally comprise either passive evaporation of water from a reservoir adjacent to the HVAC air stream, or a circulating liquid retaining medium which passes in an endless path of movement through a water bath positioned within the HVAC air stream. While such systems are somewhat effective and simple, they are generally activated when an air stream is moving through the HVAC system and do not provide precise user control. If it is desired to dispense an additional medium into the air stream, the additional medium is manually added to the bath for dispensing into the air flow. Such systems consequently have wide variations in the amount of the media dispensed into the air stream which changes as the concentration of the media being dispensed varies, such as by evaporation, as well as the conditions of the ambient air.
SUMMARY OF THE INVENTION
[0006] It is therefore an object of this invention to improve central and zoned dispensing systems for dispensing materials into a HVAC air stream.
[0007] Another object of this invention is to provide a range of user-programmable operational controls for the dispensing of materials into an HVAC air stream.
[0008] A further object of this invention is to provide a user-programmable central dispensing system for dispensing and monitoring the dispensing of one or more water-soluble materials into the air stream of an HVAC system in a predetermined and programmable quantity.
[0009] These and other objects are attained in accordance with the present invention wherein there is provided a user-programmable monitoring and dispensing system for controlling the dispensing of water vapor and various other media into an HVAC air stream in residential or commercial structures. The various media to be dispensed are preferably water-soluble, and mixed with the system water supply to be dispensed with the water vapor added to the HVAC air stream. These materials may be fragrances or aromas, intended to produce an aesthetic effect, or they can be agents capable of pesticidal, bacteriacidal, fungicidal or sporacidal effect for use as acute or prophylactic treatment for infestation.
DESCRIPTION OF THE DRAWINGS
[0010] Further objects of this invention, together with additional features contributing thereto and advantages accruing therefrom, will be apparent from the following description of a preferred embodiment of the present invention which is shown in the accompanying drawings with like reference numerals indicating corresponding parts throughout and which is to be read in conjunction with the following drawings, wherein:
[0011] [0011]FIG. 1 is a mechanical schematic of a preferred embodiment of the dispensing system to better illustrate the components thereof and the manner in which such components interrelate in the system operation;
[0012] [0012]FIG. 2 is a logic block diagram of the system operation;
[0013] [0013]FIG. 3 is a logic block diagram of the operation of the user interface keypad/display through which the system is programmed; and
[0014] [0014]FIG. 4 is a logic block diagram of the system controls through which materials are dispensed into the HVAC air stream in response to the user-defined program inputs.
[0015] These and additional embodiments of the invention may now be better understood by referring to the following detailed description of the invention wherein the illustrated embodiment is described.
DETAILED DESCRIPTION OF THE INVENTION
[0016] Throughout this description, the preferred embodiment and examples shown should be considered as exemplars, rather than limitations on the apparatus and methods of the present invention.
[0017] Referring now to the drawings, there is illustrated in FIG. 1 the various air flow components of an HVAC system and the central dispensing system of this invention. The portion of the HVAC system illustrated includes an air movement generating device, such as a blower 10 which generates an air stream which pass through duct work 11 to a desired residential or commercial space. The HVAC system includes a heat exchanger 12 positioned in the air stream path to heat the air moving through the duct 11 in response to the temperature set by a HVAC thermostat controller 20 , the input of which is entered through a user operated keypad/display unit 100 . In addition, an A/C coil 14 is positioned in the air stream to cool the temperature thereof in response to the temperature programmed through the thermostat 20 . The blower 10 , duct work 11 , heat exchanger 12 and A/C coil 14 are standard components utilized in HVAC forced air systems. Positioned down stream from the blower 10 , heat exchanger 12 and A/C coil 14 , in the direction of air movement, is a pressure or flow sensor 21 , such as available from Sensotec Inc., 2080 Arlingate Lane, Columbus, Ohio 43228, a humidity sensor 23 and a temperature sensor 25 , such as a HE-6310 Series Duct-mount humidity/temperature sensor, available from Johnson Controls, Inc., 507 East Michigan Street, Milwaukee, Wis. 53202, all of which are connected to a system central processor 50 , such as an Intel Type 8051 Microcontroller DS89C420-QCS Dallas Semiconductor Ultra High Speed 8051 Based Microcontroller PLCC Package available from Newark Electronics, 3 Marcus Boulevard, Albany, N.Y. 12205-1129, for providing air stream sensor inputs as to the air movement, moisture content of the air stream and the air stream temperature to the system central processor. Further down stream from these sensors, is a dispenser 16 which may be in the form of an ultrasonic transducer, available from Keramos Advanced Piezoelectrics, 5460 W. 84 th Street, Indianapolis, Ind. 46268 and Etalon Innovative Piezo Transducers, P.O. Box 127, Lebanon, Ind. 46052, or vaporizer through which water vapor and/or water-soluble materials, available from Aroma Tech Co., 130 Industrial Parkway, Somerville, N.J. 088076, are dispensed into the HVAC air stream in response to a user-defined program input to the system central processor 50 by means of the keypad/display unit 100 , such as a Type XK-5LC or Type LCD-96M Multi Menu Keypad available from FBII, 149 Eileen Way, Soyosset, N.Y. 11791-5316 or JDS Technologies, 12200 Thatcher Ct., Poway, Calif. 92064-6876. While a single dispenser 16 is illustrated, it is to be understood that a single dispensing head may be utilized as illustrated or multiple dispensing heads may be utilized with each one of the multiple dispensing heads being connected by means of a dilution manifold to each individual media reservoir. The dispensing heads may be piezo-electric ultrasonic transducers, atomizer spray nozzles or a media saturated evaporation wick. The dispenser 16 , as illustrated in FIG. 1, is shown dispensing into the main plenum of an HVAC system for a centralized effect from the medium dispensed. However, it is to be understood that separate dispensers may be utilized in various trunk ducts as well as the central plenum for dispersal of the medium into specific locations serviced by the HVAC system.
[0018] The display/HVAC thermostat portion 20 of the keypad/display unit 100 is coupled to the system central processor 50 to provide the inputs illustrated in FIG. 2 to control the heating/cooling operation of the system central processor 50 .
[0019] The system central processor 50 is connected to a suitable standard power supply 51 to provide power to the unit upon start up. At this time a thermostat control signal is sent 20 c from the system central processor 50 to actuate one or more of the blower 10 , heat exchanger 12 , or A/C coil 14 , in response to an on/off signal determined from the thermostat setting.
[0020] The system central processor 50 is programmed in the manner illustrated in FIG. 3, to control the operation of the media dispensing system on a daily basis, to control the dispensing of a selected medium or media, and to control the intensity thereof during the programmed cycle. The system operation, in response to the user-defined program inputs, and the output from various component sensors used in controlling system operations, are controlled in the manner illustrated in FIG. 4.
[0021] Referring again to FIG. 1, the input from the user-defined program keypad/display unit 100 , including the thermostat signal, is coupled 20 a to the system central processor 50 and appropriate display information is coupled 20 b from the system central processor 50 back to the keypad/display 100 to confirm that the signals input from the keypad/display unit 100 have been received and processed by the system central processor 50 . While in the preferred embodiment disclosed herein as the best mode contemplated by the inventor for practicing the invention the keypad/display unit 100 is utilized, it is to be understood that the input coupled 20 a to the dispenser system central processor 50 could be from a home automation control system commonly used to network and integrate the control and function of several subsystems in the space being controlled, with the feedback 20 b from the system central processor 50 being coupled to such an automation control system instead of a keypad/display unit 100 . A suitable home automation control system, not shown, has been found to be an Omni, Omni LT, and Omni Pro models available from Home Automation, Inc., 5725 Powell Street, Suite A, New Orleans, La. 70123.
[0022] When the HVAC system is in operation, an input 21 a will be received from the pressure or flow sensor 21 to the system central processor 50 confirming the movement of the air stream in the duct 11 , and input signals will be received 23 a from the humidity sensor 23 and from the temperature sensor 25 to provide input 25 a to the system central processor 50 as to the moisture content and the temperature of the air stream moving through the duct 11 . This information will be processed through the system central processor 50 and control 30 a the operation of a water intake control valve 30 , available from South Bend Controls, 1237 Northside Boulevard, South Bend, Ind. 46615; HydraForce, Inc., 500 Barclay Boulevard, Lincolnshire, Ill. 60069; and Deltrol Controls, 2740 South 20 th Street, Milwaukee, Wis. 53215, through which water passes from a suitable municipal or domestic supply source 32 into a dilution manifold 34 wherein water soluble media to be dispensed into the air stream are added for dilution prior to dispensing.
[0023] The water from water supply 32 is also connected to one or more media reservoir tanks, illustrated in the preferred embodiment as three reservoirs 35 a, 35 b and 35 c. These reservoirs may be either permanent containers which are refillable, or be replaceable as modular units. In addition, each reservoir 35 a, 35 b and 35 c incorporates a recognition media such as a bar code, magnetic strip or holographic symbol so that the system central processor 50 will receive a signal that the reservoir is in proper position and the information contained therein will effect display of the particular medium being dispensed on the keypad/display unit 100 . In addition, it is to be understood that the contour of each of the reservoirs may be such that when the reservoir is properly positioned, such a signal will be provided to the system central processor.
[0024] Each of the reservoirs 35 a, 35 b and 35 c preferably contain an inner bladder which effectively creates a second chamber within the media reservoir and the space around the inner bladder is connected in parallel to the water supply 32 such that the water fills the space around the bladder to displace the media contained within the reservoir towards the mixing manifold. Each of the media reservoirs is connected to the dilution manifold 34 by media output valves 36 a, 36 b and 36 c such as inert proportional valves available from the water intake control valve supplier and which are individually activated 37 a, 37 b and 37 c by the system control processor 50 to control the dispensing of water soluble media into the dilution manifold 34 from the respective media reservoirs 35 a, 35 b and 35 c. The water soluble media is mixed with water in the dilution manifold 34 and passes to the ultrasonic transducer or vaporizer 16 in response to the actuation 38 a of a dispensing control valve 38 available from the water intake control valve suppliers previously identified and operated by the system central processor 50 in accordance with the information coupled to the central system processor by the temperature and humidity sensors 25 and 23 , respectively, and the programmed input entered by the user through the keypad/display unit 100 . The intensity of the media contained within the media reservoirs may be achieved by varying the amount of media dispensed during and “on” cycle wherein the media reservoirs contain a constant concentration of the media or the quantity of the medium dispensed may be held constant with the concentration of the media being controlled by controlling the dilution of the medium in the dilution manifold 34 .
[0025] The media reservoirs 35 a, 35 b and 35 c are each provided with a sensor 39 a, 39 b and 39 c, respectively, available from Gems Sensors, 1 Cowles Road, Plainville, Conn. 06062, coupled to the system central processor 50 to monitor the level of the medium contained within each reservoir for proper dispensing of the medium contained therein. Alternatively, instead of actively monitoring the level of the medium in the reservoirs 35 a, 35 b and 35 c, the system central processor 50 could calculate the quantity dispensed and thereby derive the amount remaining, assuming that the initial amount supplied to these reservoirs is constant, or otherwise “known” by the system central processor. The system central processor 50 can be programmed, as illustrated in FIG. 3, to dispense one or more of the media from the reservoirs 35 a, 35 b and 35 c into the dilution manifold 34 in increments stepped to vary the intensity or concentration of the media in the dilution manifold in accordance with the input to the system central processor 50 through the keypad/display unit 100 . A water supply pressure feedback input 33 a is connected to the system control processor 50 from a check valve and pressure sensor 33 , available from Sensotec Inc. 2080 Arlingate Lane, Columbus, Ohio 43228, carried in the municipal or domestic water supply line to ensure that an adequate supply of domestic water 32 at a desired pressure is available for use in the dispensing system.
[0026] Referring now to FIG. 2, there is illustrated the informational inputs that a user enters into the system through operation of the keypad/display unit 100 to control operation of the system central processor 50 to perform the desired functions. Upon initial system power-up, the user manually enters the time and date through the keypad/display unit 100 which is coupled 102 to the system central processor 50 . This information, once coupled to the system central processor 50 , will be used by the processor to accurately maintain current time in a manner known to those skilled in the art, and displayed on the keypad/display unit 100 .
[0027] The user then enters information to place the system central processor in either an “Active” or “Standby” mode. If the “Standby” mode is selected, the system central processor 100 will be idle and the keypad/display unit 100 will display that the system is in the “Standby” mode awaiting further instruction. If the user elects to operate the system, the “Active” mode is selected, displayed, and the user may elect to have the system operated in either a “Manual” or “Program” mode. If the “Manual” mode of operation is selected, the user can either elect to have the system operate in a “Default” sequence or a “Specified” sequence of operation.
[0028] In the “Default” sequence of operation, the system central processor 50 will sequentially actuate the first medium dispenser 35 a which will continue to operate to depletion. Upon depletion a signal will be sent by the sensor 39 a to the system central processor 50 which will then actuate the next available medium dispenser, e.g.: 35 b, which will continue to operate to depletion. At that time the sensor 39 b will send a signal to the system central processor 50 which will actuate the next available medium dispenser until all of the medium has been dispensed, at which time the system central processor 50 will cause a message to be displayed on the keypad/display unit 100 that the dispensers are empty and the system has been placed on “Standby”.
[0029] If the user elects to choose a “Specified” sequence rather than the “Default” sequence, the user can input a particular order by which the media will be used to depletion, by entering instructions through the keypad/display unit 100 for the system central processor 50 to start with a first programmed medium dispenser and then proceed upon depletion to a second specified medium dispenser and upon the depletion thereof to proceed to another specified medium dispenser. However, regardless of which mode of operation the user selects, in either of these modes the user is required to set the intensity level of each of the media to be discharged from the dispenser 35 a, 35 b, and 35 c into the dilution manifold 34 . The manner in which the intensity parameters are input to the system central processor 50 is illustrated in FIG. 3.
[0030] If the user chooses to operate the system in a “Program” mode, whereby individual medium and intensity parameters can be selected and set for individual days of the week, the user selects the “Program” option when the system “Active” display is presented.
[0031] Referring to FIG. 3, upon entering the “Program” mode the user is instructed to either accept or edit a previous program setting. If at this time the user elects not to enter the “Program” mode, an “Escape” instruction is provided which returns the user to the “Active” display whereby the system may be operated in the “Manual” mode or the user may return the system to the “Standby” mode. If, however, the user elects to proceed with the “Program” mode, the user must either “Accept” the previous program settings (or the factory settings if this is an initial installation) or select the “Edit” option if it is desired to make changes in the program previously entered. Throughout the operation in the “Program” mode, an “Escape” option is available to enable the user to return to the “Active” input level thereby cancelling all instructions entered to that point and the system returning to the previous program settings, or a “Menu Step Back” option is also available to permit the user to correct an entry error without losing the settings previously entered.
[0032] Upon selecting the “Edit” option, the user sequentially selects each day of the week to define the parameters of operation of the system for that day. These parameters include the time of program operation, identified as “Cycle 1”, “Cycle 2”, “Cycle 3” and “Cycle 4”. These times of operation are set for each day and may be individually accepted as presented previously, or edited. After the program cycle is selected, the particular medium, water vapor only or one of the media 35 a, 35 b, 35 c which is to be dispensed, may be chosen. The intensity level (concentration) of the selected medium which is to be dispensed may be selected as well as the time period selected for operation during the program cycle can be chosen and entered through the keyboard/display unit 100 into the system central processor 50 . This information is sequentially entered into the system central processor 50 through the keypad/display unit 100 for each day of the week.
Functional Description
[0033] Referring now to FIG. 4, the user inputs the initial information into the system central processor 50 through the keypad/display unit 100 in the manner previously described, selects the mode of operation and programs the system as desired. The temperature sensor 25 , humidity sensor 23 , flow sensor 21 , media sensors 39 a, 39 b, and 39 c, and water supply sensor 33 a all provide their respective input signals to the system central processor 50 . The keyboard/display 100 shows the status of the informational inputs. If the program cycle inputs, the operational sensor inputs and time of operation call for an activation of a dispensing sequence, dispensing operation is initiated and the keypad/display 100 shows that the system is dispensing as instructed. The selected media dispensing valve 36 a, 36 b or 36 c is opened the prescribed extent and duration. The water intake control valve 30 is opened allowing water and the selected medium to mix in the dilution manifold 34 . The dispensing control valve 38 is opened and the dispenser 16 is actuated for a time period determined by the parameters of the ambient air moving through the air duct 11 . The input from the ambient air flow sensors 21 , 23 and 25 coupled to the system central processor 50 prevent the system from dispensing media at a level beyond the capacity of the air stream flow to move the dispensed medium through the HVAC system.
[0034] While this invention has been described in the specification and illustrated in the drawings with reference to a preferred embodiment, the structure of which has been disclosed herein, it will be understood by those skilled in the art to which this invention pertains that various changes may be made, and equivalents may be substituted for elements of the invention without departing from the scope of the claims. Therefore, it is intended that the invention not be limited to the particular embodiment disclosed in the specification and shown in the drawings as the best mode presently known by the inventors for carrying out this invention, nor confined to the details set forth, but that the invention will include all embodiments, modifications and changes as may come within the scope of the following claims: | A user-programmable monitoring and dispensing system for controlling the dispensing of water vapor and various other media into an HVAC air stream in residential or commercial structures. The various media to be dispensed are preferably water-soluble, and mixed with the system water supply to be dispensed with the water vapor added to the HVAC air stream. These materials may be fragrances or aromas, intended to produce an aesthetic effect, or they can be agents capable of pesticidal, bacteriacidal, fungicidal or sporacidal effect for use as acute or prophylactic treatment for infestation. | 5 |
BACKGROUND OF THE INVENTION
1. Field of the Invention
The present invention relates to burner tripods and more particularly pertains to a new folding propane cooker with inlet support brace for providing a propane cooker that has improved air ventilation, more robust hinged couplings, and an improved inlet which is less susceptible to being inadvertently detached.
2. Description of the Prior Art
The use of burner tripods is known in the prior art. More specifically, burner tripods heretofore devised and utilized are known to consist basically of familiar, expected and obvious structural configurations, notwithstanding the myriad of designs encompassed by the crowded prior art which have been developed for the fulfillment of countless objectives and requirements.
Known prior art burner tripods include U.S. Pat. No. 5,423,308; U.S. Pat. No. 5,333,540; U.S. Pat. No. 4,949,701; U.S. Pat. No. 4,393,857; U.S. Pat. No. 4,210,118; and U.S. Pat. No. Des 256,316.
The prior art burner tripods further includes that which is shown in FIGS. 1-3. Such tripod includes a cylindrical central member with two legs pivotally mounted thereon and a third leg fixed with respect to the central member. The foregoing pivotal coupling is accomplished by way of an inferior compression fitting. The central member has a height which is approximately equal to that of the inboard extents of the legs. As shown in FIG. 3, a bottom face of the tripod has a bottom face with a washer welded therein for reasons that will soon become apparent. The prior art tripod further includes an inlet pipe which is constructed from a bendable brake line. As shown in FIG. 3, the brake line has a vertically oriented inboard portion welded within an aperture of the washer and having a grease zert mounted to a top end thereof. As such, ventilation is precluded. The prior art tripod further includes a horizontally oriented outboard portion spaced below the bottom face of the central member and extending therefrom in an adjacent spaced relationship with the fixed leg. As shown in FIGS. 1 & 2, the horizontally oriented outboard portion extends past an outboard extent of the fixed leg whereat a coupler is positioned for connecting with a gas supply hose. The inlet tube of the prior art tripod is highly susceptible to being broken off. The prior art device is constructed from a stainless metal.
In these respects, the folding propane cooker with inlet support brace according to the present invention substantially departs from the conventional concepts and designs of the prior art, and in so doing provides an apparatus primarily developed for the purpose of providing a propane cooker that has improved air ventilation, more robust hinged couplings, and an improved inlet which is less susceptible to being inadvertently detached.
SUMMARY OF THE INVENTION
In view of the foregoing disadvantages inherent in the known types of burner tripods now present in the prior art, the present invention provides a new folding propane cooker with inlet support brace construction wherein the same can be utilized for providing a propane cooker that has improved air ventilation, more robust hinged couplings, and an improved inlet which is less susceptible to being inadvertently detached.
The general purpose of the present invention, which will be described subsequently in greater detail, is to provide a new folding propane cooker with inlet support brace apparatus and method which has many of the advantages of the burner tripods mentioned heretofore and many novel features that result in a new folding propane cooker with inlet support brace which is not anticipated, rendered obvious, suggested, or even implied by any of the prior art burner tripods, either alone or in any combination thereof.
To attain this, the present invention generally comprises a vertically oriented cylindrical central member having a tubular side wall, an open bottom face, and an open top face. Both open faces are completely open in that they each define openings having a diameter equal to that of the central member. FIG. 4 shows that two cylindrical pipes are each mounted to an exterior surface of the side wall along an axis in parallel with that of the central member. Each pipe has a length less than that of the central member and a diameter about 1/4 that of the central member. Next provided are three legs each having a horizontally oriented linear top bar and a vertically oriented first linear side bar connected to one end of the top bar and extending downwardly therefrom. The first linear side bar is equipped with a first length which is about twice a height of the central member. A vertically oriented second linear side bar is connected to another end of the top bar and extends downwardly therefrom. The second linear side bar is equipped with a second length greater than the first length. An angled linear bottom bar is connected between bottom ends of the side bars such that each of the bars reside in a similar plane. The first linear side bar of two of the legs has a central extent being rotatably coupled within the two pipes. Further, a pair of spaced washers are welded to the forgoing two legs which extend radially therefrom in the form of flanges for precluding vertical movement within the pipes. The first linear side bar of one of the legs has a central extent being fixedly welded directly to the central member. As such, the forgoing leg resides in a plane extending radially from the central member. In use, the legs have deployed orientations extending radially from the central member and spaced by 120 degrees. Further, the legs are capable of stored orientations each directed in a similar direction and residing in parallel planes. Also included is a rigid inlet pipe which is linear along an entire length thereof. The inlet pipe has an inboard threaded end and an outboard threaded end. A first portion of the pipe adjacent to and spaced from the inboard end is welded to a lower peripheral edge of the central member. As such, the inlet pipe extends radially therefrom. A second portion of the pipe adjacent to and spaced from the first portion is welded to the first linear side bar of the fixed leg. The outboard threaded end of the inlet pipe terminates half way between the linear side bars, as shown in FIG. 4. For precluding the inlet tube from being inadvertently removed, a linear brace has a first end welded to an upper extent of the first linear side bar of the fixed leg at a point level with the top face of the central member. A second end of the brace is welded to an inboard extent of the bottom bar of the fixed leg such that the brace resides within the plane that includes the bars of the fixed leg. It should be noted that a central extent of the inlet pipe is welded just below a central extent of the brace. Mounted on the end of the inlet tube is a brass cap having a closed end, an open end, and a hexagonal side wall. The side wall defines an interior space having a threaded periphery adjacent the open end for attachment to the inboard threaded end of the inlet tube. The side wall has an orifice formed therein which remains in communication with the inlet tube.
There has thus been outlined, rather broadly, the more important features of the invention in order that the detailed description thereof that follows may be better understood, and in order that the present contribution to the art may be better appreciated. There are additional features of the invention that will be described hereinafter and which will form the subject matter of the claims appended hereto.
In this respect, before explaining at least one embodiment of the invention in detail, it is to be understood that the invention is not limited in its application to the details of construction and to the 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.
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.
It is therefore an object of the present invention to provide a new folding propane cooker with inlet support brace apparatus and method which has many of the advantages of the burner tripods mentioned heretofore and many novel features that result in a new folding propane cooker with inlet support brace which is not anticipated, rendered obvious, suggested, or even implied by any of the prior art burner tripods, either alone or in any combination thereof.
It is another object of the present invention to provide a new folding propane cooker with inlet support brace which may be easily and efficiently manufactured and marketed.
It is a further object of the present invention to provide a new folding propane cooker with inlet support brace which is of a durable and reliable construction.
An even further object of the present invention is to provide a new folding propane cooker with inlet support brace which is susceptible of a low cost of manufacture with regard to both materials and labor, and which accordingly is then susceptible of low prices of sale to the consuming public, thereby making such folding propane cooker with inlet support brace economically available to the buying public.
Still yet another object of the present invention is to provide a new folding propane cooker with inlet support brace which provides in the apparatuses and methods of the prior art some of the advantages thereof, while simultaneously overcoming some of the disadvantages normally associated therewith.
Still another object of the present invention is to provide a new folding propane cooker with inlet support brace for providing a propane cooker that has improved air ventilation, more robust hinged couplings, and an improved inlet which is less susceptible to being inadvertently detached.
Even still another object of the present invention is to provide a new foldable fuel cooker including a central member and a plurality of legs pivotally connected to the central member via pipes mounted thereon. An inlet tube is connected to an open bottom of the central member and extends therefrom to a central extent of one of the legs. A brace is mounted on one of the legs for preventing the inlet tube from being inadvertently removed.
These together with other objects of the invention, along with the various features of novelty which characterize the invention, are pointed out with particularity in the claims annexed to and forming a part of this disclosure. For a better understanding of the invention, its operating advantages and the specific objects attained by its uses, reference should be made to the accompanying drawings and descriptive matter in which there are illustrated preferred embodiments of the invention.
BRIEF DESCRIPTION OF THE DRAWINGS
The invention will be better understood and objects other than those set forth above will become apparent when consideration is given to the following detailed description thereof. Such description makes reference to the annexed drawings wherein:
FIG. 1 is a perspective view of a prior art propane cooker.
FIG. 2 is a top view of the prior art propane cooker.
FIG. 3 is a cross-sectional view of the inlet pipe of the prior art propane cooker.
FIG. 4 is a perspective view of a new folding propane cooker with inlet support brace according to the present invention.
FIG. 5 is a top view of the present invention in a stored orientation.
FIG. 6 is a top view of the present invention in a deployed orientation.
FIG. 7 is a side view of the present invention.
FIG. 8 is a cross-sectional view of the present invention taken along line 8--8 shown in FIG. 4.
FIG. 9 is a cross-sectional view of the present invention taken along line 9--9 shown in FIG. 6.
DESCRIPTION OF THE PREFERRED EMBODIMENT
With reference now to the drawings, and in particular to FIGS. 1 through 9 thereof, a new folding propane cooker with inlet support brace embodying the principles and concepts of the present invention and generally designated by the reference numeral 10 will be described.
The present invention, as designated as numeral 10, includes a vertically oriented cylindrical central member 12 constructed from black steel and having a tubular side wall 14, an open bottom face, and an open top face. Both open faces are completely open in that they each define openings having a diameter equal to that of the central member. Preferably, the central member is 2 inches in diameter.
FIG. 4 shows that two cylindrical pipes 16 are each mounted to an exterior surface of the side wall along an axis in parallel with that of the central member. Each pipe has a length less than that of the central member and a diameter about 1/4 that of the central member. The pipes are each constructed from black steel.
Next provided are three legs 18 constructed from black steel and each having a horizontally oriented linear top bar 20 and a vertically oriented first linear side bar 22 connected to one end of the top bar and extending downwardly therefrom. The first linear side bar is equipped with a first length which is about twice a height of the central member. A vertically oriented second linear side bar 24 is connected to another end of the top bar and extends downwardly therefrom. The second linear side bar is equipped with a second length greater than the first length. An angled linear bottom bar 26 is connected between bottom ends of the side bars such that each of the bars reside in a similar plane.
The first linear side bar of two of the legs has a central extent being rotatably coupled within the two pipes. This is accomplished in a manner shown in FIG. 9. Essentially, a pair of spaced washers 28 are welded to the forgoing two legs which extend radially therefrom in the form of flanges for precluding vertical movement within the pipes. This affords a superior coupling which allows the legs to support great amounts of weight. Ideally, the weld is effected on an upper and lower surface of the top and bottom washers, respectively. Note FIG. 9. The first linear side bar of another one of the legs 30 has a central extent being fixedly welded directly to the central member. As such, the present leg resides in a plane extending radially from the central member. In use, the legs have deployed orientations extending radially from the central member and spaced by 120 degrees. Further, the legs are capable of stored orientations each directed in a similar direction and residing in parallel planes.
Also included is a rigid inlet pipe 32 constructed from black steel which is linear along an entire length thereof. The inlet pipe has an inboard threaded end and an outboard threaded end. A first portion 34 of the pipe adjacent to and spaced from the inboard end is welded to a lower peripheral edge of the central member. As such, the inlet pipe extends radially therefrom. A second portion 36 of the pipe adjacent to and spaced from the first portion is welded to the first linear side bar of the fixed leg. The outboard threaded end of the inlet pipe terminates half way between the linear side bars, as shown in FIG. 4.
For precluding the inlet tube from being inadvertently removed, a linear brace 38 has a first end welded to an upper extent of the first linear side bar of the fixed leg at a point level with the top face of the central member. A second end of the brace is welded to an inboard extent of the bottom bar of the fixed leg such that the brace resides within the plane that includes the bars of the fixed leg. It should be noted that a central extent of the inlet pipe is welded just below a central extent of the brace. In the preferred embodiment, the brace is planar rectangular in form with a width equal to a cross-sectional diameter of the bars of the fixed leg.
Mounted on the end of the inlet tube is a brass cap 40 having a closed end, an open end, and a hexagonal side wall. Note FIG. 8. The side wall defines an interior space having a threaded periphery adjacent the open end for attachment to the inboard threaded end of the inlet tube. The side wall has an orifice 41 formed therein which remains in communication with the inlet tube. As shown in FIG. 8, a majority of the bottom open face of the central member remains open for optimum ventilation.
Finally, an elastomeric flexible hose 42 is provided including a first end having a threaded sleeve rotatably coupled thereto for releasably engaging the outboard threaded end of the inlet tube. A second end of the flexible hose has a quick release adapter 44 for removably attaching to a propane source.
As to a further discussion of the manner of usage and operation of the present invention, the same should be apparent from the above description. Accordingly, no further discussion relating to the manner of usage and operation will be provided.
With respect to the above description then, it is to be realized that the optimum dimensional relationships for the parts of the invention, to include variations in size, materials, shape, form, function and manner of operation, assembly and use, are deemed readily apparent and obvious to one skilled in the art, and all equivalent relationships to those illustrated in the drawings and described in the specification are intended to be encompassed by the present invention.
Therefore, the foregoing is considered as illustrative only of the principles of the invention. Further, since numerous modifications and changes will readily occur to those skilled in the art, it is not desired to limit the invention to the exact construction and operation shown and described, and accordingly, all suitable modifications and equivalents may be resorted to, falling within the scope of the invention. | A foldable fuel cooker is provided including a central member and a plurality of legs pivotally connected to central member via pipes mounted thereon. An inlet tube is connected to the central member and extends therefrom to a central extent of one of the legs. A brace is mounted on one of the legs for preventing the inlet tube from being inadvertently removed. | 8 |
BACKGROUND OF THE INVENTION
[0001] This invention relates generally to turbomachinery compressors and more particularly relates to rotor blade stages of such compressors.
[0002] A gas turbine engine includes, in serial flow communication, a compressor, a combustor, and turbine. The turbine is mechanically coupled to the compressor and the three components define a turbomachinery core. The core is operable in a known manner to generate a flow of hot, pressurized combustion gases to operate the engine as well as perform useful work such as providing propulsive thrust or mechanical work. One common type of compressor is an axial-flow compressor with multiple rotor stages each including a disk with a row of axial-flow airfoils, referred to as compressor blades.
[0003] For reasons of thermodynamic cycle efficiency, it is generally desirable to incorporate a compressor having the highest possible pressure ratio (that is, the ratio of inlet pressure to outlet pressure). It is also desirable to include the fewest number of compressor stages. However, there are well-known inter-related aerodynamic limits to the maximum pressure ratio and mass flow possible through a given compressor stage.
[0004] It is known to reduce weight, improve rotor performance, and simplify manufacturing by minimizing the total number of compressor airfoils used in a given rotor blade row . However, as airfoil blade count is reduced the accompanying reduced hub solidity tends to cause the airflow in the hub region of the rotor airfoil to undesirably separate from the airfoil surface.
[0005] It is also known to configure the disk with a non-axisymmetric “scalloped” surface profile to reduce mechanical stresses in the disk. An aerodynamically adverse side effect of this feature is to increase the rotor blade row through flow area and aerodynamic loading level promoting airflow separation.
[0006] Accordingly, there remains a need for a compressor rotor that is operable with sufficient stall range and an acceptable balance of aerodynamic and structural performance.
BRIEF DESCRIPTION OF THE INVENTION
[0007] This need is addressed by the present invention, which provides an axial compressor having a rotor blade row including compressor blades and splitter blade airfoils.
[0008] According to one aspect of the invention, a compressor apparatus includes: a rotor including: a disk mounted for rotation about a centerline axis, an outer periphery of the disk defining a flowpath surface; an array of airfoil-shaped axial-flow compressor blades extending radially outward from the flowpath surface, wherein the compressor blades each have a root, a tip, a leading edge, and a trailing edge, wherein the compressor blades have a chord dimension and are spaced apart by a circumferential spacing, the ratio of the chord dimension to the circumferential spacing defining a blade solidity parameter; and an array of airfoil-shaped splitter blades alternating with the compressor blades, wherein the splitter blades each have a root, a tip, a leading edge, and a trailing edge; wherein at least one of a chord dimension of the splitter blades at the roots thereof and a span dimension of the splitter blades is less than the corresponding dimension of the compressor blades.
[0009] According to another aspect of the invention, the solidity parameter is selected to as to result in hub flow separation under normal operating conditions.
[0010] According to another aspect of the invention, the flowpath surface is not a body of revolution.
[0011] According to another aspect of the invention, the flowpath surface includes a concave scallop between adjacent compressor blades.
[0012] According to another aspect of the invention, the scallop has a minimum radial depth adjacent the roots of the compressor blades, and has a maximum radial depth at a position approximately midway between adjacent compressor blades.
[0013] According to another aspect of the invention, each splitter blade is located approximately midway between two adjacent compressor blades.
[0014] According to another aspect of the invention, the splitter blades are positioned such that their trailing edges are at approximately the same axial position as the trailing edges of the compressor blades, relative to the disk.
[0015] According to another aspect of the invention, the span dimension of the splitter blades is 50% or less of the span dimension of the compressor blades.
[0016] According to another aspect of the invention, the span dimension of the splitter blades is 30% or less of the span dimension of the compressor blades.
[0017] According to another aspect of the invention, the chord dimension of the splitter blades at the roots thereof is 50% or less of the chord dimension of the compressor blades at the roots thereof.
[0018] According to another aspect of the invention, the chord dimension of the splitter blades at the roots thereof is 50% or less of the chord dimension of the compressor blades at the roots thereof.
[0019] According to another aspect of the invention, a compressor includes a plurality of axial-flow stages, at least a selected one of the stages includes: a disk mounted for rotation about a centerline axis, an outer periphery of the disk defining a flowpath surface; an array of airfoil-shaped axial-flow compressor blades extending radially outward from the flowpath surface, wherein the compressor blades each have a root, a tip, a leading edge, and a trailing edge, wherein the compressor blades have a chord dimension and are spaced apart by a circumferential spacing, the ratio of the chord dimension to the circumferential spacing defining a blade solidity parameter; and an array of airfoil-shaped splitter blades alternating with the compressor blades, wherein the splitter blades each have a root, a tip, a leading edge, and a trailing edge; wherein at least one of a chord dimension of the splitter blades at the roots thereof and a span dimension of the splitter blades is less than the corresponding dimension of the compressor blades.
[0020] According to another aspect of the invention, the solidity parameter is selected to as to result in hub flow separation under normal operating conditions.
[0021] According to another aspect of the invention, the flowpath surface is not a body of revolution.
[0022] According to another aspect of the invention, the flowpath surface includes a concave scallop between adjacent compressor blades.
[0023] According to another aspect of the invention, the span dimension of the splitter blades is 50% or less of the span dimension of the compressor blades.
[0024] According to another aspect of the invention, the span dimension of the splitter blades is 30% or less of the span dimension of the compressor blades.
[0025] According to another aspect of the invention, the chord dimension of the splitter blades at the roots thereof is 50% or less of the chord dimension of the compressor blades at the roots thereof.
[0026] According to another aspect of the invention, the chord dimension of the splitter blades at the roots thereof is 50% or less of the chord dimension of the compressor blades at the roots thereof
[0027] According to another aspect of the invention, the selected stage is the aft-most rotor of the compressor.
BRIEF DESCRIPTION OF THE DRAWINGS
[0028] The invention may be best understood by reference to the following description taken in conjunction with the accompanying drawing figures in which:
[0029] FIG. 1 is a cross-sectional, schematic view of a gas turbine engine that incorporates a compressor rotor apparatus constructed in accordance with an aspect of the present invention;
[0030] FIG. 2 is a perspective view of a portion of a rotor of a compressor apparatus;
[0031] FIG. 3 is a top plan view of a portion of a rotor of a compressor apparatus;
[0032] FIG. 4 is an aft elevation view of a portion of a rotor of a compressor apparatus;
[0033] FIG. 5 is a side view taken along lines 5 - 5 of FIG. 4 ;
[0034] FIG. 6 is a side view taken along lines 6 - 6 of FIG. 4 ;
[0035] FIG. 7 is a perspective view of a portion of a rotor of an alternative compressor apparatus;
[0036] FIG. 8 is a top plan view of a portion of a rotor of an alternative compressor apparatus;
[0037] FIG. 9 is an aft elevation view of a portion of a rotor of an alternative compressor apparatus;
[0038] FIG. 10 is a side view taken along lines 10 - 10 of FIG. 9 ; and
[0039] FIG. 11 is a side view taken along lines 11 - 11 of FIG. 9 .
DETAILED DESCRIPTION OF THE INVENTION
[0040] Referring to the drawings wherein identical reference numerals denote the same elements throughout the various views, FIG. 1 illustrates a gas turbine engine, generally designated 10 . The engine 10 has a longitudinal centerline axis 11 and includes, in axial flow sequence, a fan 12 , a low-pressure compressor or “booster” 14 , a high-pressure compressor (“HPC”) 16 , a combustor 18 , a high-pressure turbine (“HPT”) 20 , and a low-pressure turbine (“LPT”) 22 . Collectively, the HPC 16 , combustor 18 , and HPT 20 define a core 24 of the engine 10 . The HPT 20 and the HPC 16 are interconnected by an outer shaft 26 . Collectively, the fan 12 , booster 14 , and LPT 22 define a low-pressure system of the engine 10 . The fan 12 , booster 14 , and LPT 22 are interconnected by an inner shaft 28 .
[0041] In operation, pressurized air from the HPC 16 is mixed with fuel in the combustor 18 and burned, generating combustion gases. Some work is extracted from these gases by the HPT 20 which drives the compressor 16 via the outer shaft 26 . The remainder of the combustion gases are discharged from the core 24 into the LPT 22 . The LPT 22 extracts work from the combustion gases and drives the fan 12 and booster 14 through the inner shaft 28 . The fan 12 operates to generate a pressurized fan flow of air. A first portion of the fan flow (“core flow”) enters the booster 14 and core 24 , and a second portion of the fan flow (“bypass flow”) is discharged through a bypass duct 30 surrounding the core 24 . While the illustrated example is a high-bypass turbofan engine, the principles of the present invention are equally applicable to other types of engines such as low-bypass turbofans, turbojets, and turboshafts.
[0042] It is noted that, as used herein, the terms “axial” and “longitudinal” both refer to a direction parallel to the centerline axis 11 , while “radial” refers to a direction perpendicular to the axial direction, and “tangential” or “circumferential” refers to a direction mutually perpendicular to the axial and tangential directions. As used herein, the terms “forward” or “front” refer to a location relatively upstream in an air flow passing through or around a component, and the terms “aft” or “rear” refer to a location relatively downstream in an air flow passing through or around a component. The direction of this flow is shown by the arrow “F” in FIG. 1 . These directional terms are used merely for convenience in description and do not require a particular orientation of the structures described thereby.
[0043] The HPC 16 is configured for axial fluid flow, that is, fluid flow generally parallel to the centerline axis 11 . This is in contrast to a centrifugal compressor or mixed-flow compressor. The HPC 16 includes a number of stages, each of which includes a rotor comprising a row of airfoils or blades 32 (generically) mounted to a rotating disk 34 , and row of stationary airfoils or vanes 36 . The vanes 36 serve to turn the airflow exiting an upstream row of blades 32 before it enters the downstream row of blades 32 .
[0044] FIGS. 2-6 illustrate a portion of a rotor 38 constructed according to a first exemplary embodiment of the present invention and suitable for inclusion in the HPC 16 . As an example, the rotor 38 may be incorporated into one or more of the stages in the aft half of the HPC 16 , particularly the last or aft-most stage.
[0045] The rotor 38 includes a disk 40 with a web 42 and a rim 44 . It will be understood that the complete disk 40 is an annular structure mounted for rotation about the centerline axis 11 . The rim 44 has a forward end 46 and an aft end 48 . An annular flowpath surface 50 extends between the forward and aft ends 46 , 48 .
[0046] An array of compressor blades 52 extend from the flowpath surface 50 . Each compressor blade extends from a root 54 at the flowpath surface 50 to a tip 56 , and includes a concave pressure side 58 joined to a convex suction side 60 at a leading edge 62 and a trailing edge 64 . As best seen in FIG. 5 , each compressor blade 52 has a span (or span dimension) “S 1 ” defined as the radial distance from the root 54 to the tip 56 , and a chord (or chord dimension) “C 1 ” defined as the length of an imaginary straight line connecting the leading edge 62 and the trailing edge 64 . Depending on the specific design of the compressor blade 52 , its chord C 1 may be different at different locations along the span S 1 . For purposes of the present invention, the relevant measurement is the chord C 1 at the root 54 .
[0047] As seen in FIG. 4 , the flowpath surface 50 is not a body of revolution. Rather, the flowpath surface 50 has a non-axisymmetric surface profile. As an example of a non-axisymmetric surface profile, it may be contoured with a concave curve or “scallop” 66 between each adjacent pair of compressor blades 52 . For comparison purposes, the dashed lines in FIG. 4 illustrate a hypothetical cylindrical surface with a radius passing through the roots 54 of the compressor blades 52 . It can be seen that the flowpath surface curvature has its maximum radius (or minimum radial depth of the scallop 66 ) at the compressor blade roots 54 , and has its minimum radius (or maximum radial depth “d” of the scallop 66 ) at a position approximately midway between adjacent compressor blades 52 .
[0048] In steady state or transient operation, this scalloped configuration is effective to reduce the magnitude of mechanical and thermal hoop stress concentration at the airfoil hub intersections on the rim 44 along the flowpath surface 50 . This contributes to the goal of achieving acceptably-long component life of the disk 40 . An aerodynamically adverse side effect of scalloping the flowpath 50 is to increase the rotor passage flow area between adjacent compressor blades 52 . This increase in rotor passage through flow area increases the aerodynamic loading level and in turn tends to cause undesirable flow separation on the suction side 60 of the compressor blade 52 , at the inboard portion near the root 54 , and at an aft location, for example approximately 75% of the chord distance C 1 from the leading edge 62 .
[0049] An array of splitter blades 152 extend from the flowpath surface 50 . One splitter blade 152 is disposed between each pair of compressor blades 52 . In the circumferential direction, the splitter blades 152 may be located halfway or circumferentially biased between two adjacent compressor blades 52 , or circumferentially aligned with the deepest portion d of the scallop 66 . Stated another way, the compressor blades 52 and splitter blades 152 alternate around the periphery of the flowpath surface 50 . Each splitter blade 152 extends from a root 154 at the flowpath surface 50 to a tip 156 , and includes a concave pressure side 158 joined to a convex suction side 160 at a leading edge 162 and a trailing edge 164 . As best seen in FIG. 6 , each splitter blade 152 has a span (or span dimension) “S 2 ” defined as the radial distance from the root 154 to the tip 156 , and a chord (or chord dimension) “C 2 ” defined as the length of an imaginary straight line connecting the leading edge 162 and the trailing edge 164 . Depending on the specific design of the splitter blade 152 , its chord C 2 may be different at different locations along the span S 2 . For purposes of the present invention, the relevant measurement is the chord C 2 at the root 154 .
[0050] The splitter blades 152 function to locally increase the hub solidity of the rotor 38 and thereby prevent the above-mentioned flow separation from the compressor blades 52 . A similar effect could be obtained by simply increasing the number of compressor blades 152 , and therefore reducing the blade-to-blade spacing. This, however, has the undesirable side effect of increasing aerodynamic surface area frictional losses which would manifest as reduced aerodynamic efficiency and increased rotor weight. Therefore, the dimensions of the splitter blades 152 and their position may be selected to prevent flow separation while minimizing their surface area. The splitter blades 152 are positioned so that their trailing edges 164 are at approximately the same axial position as the trailing edges of the compressor blades 52 , relative to the rim 44 . This can be seen in FIG. 3 . The span S 2 and/or the chord C 2 of the splitter blades 152 may be some fraction less than unity of the corresponding span S 1 and chord C 1 of the compressor blades 52 . These may be referred to as “part-span” and/or “part-chord” splitter blades. For example, the span S 2 may be equal to or less than the span S 1 . Preferably for reducing frictional losses, the span S 2 is 50% or less of the span S 1 . More preferably for the least frictional losses, the span S 2 is 30% or less of the span S 1 . As another example, the chord C 2 may be equal to or less than the chord C 1 . Preferably for the least frictional losses, the chord C 2 is 50% or less of the chord C 1 .
[0051] The disk 40 , compressor blades 52 , and splitter blades 152 may be constructed from any material capable of withstanding the anticipated stresses and environmental conditions in operation. Non-limiting examples of known suitable alloys include iron, nickel, and titanium alloys. In FIGS. 2-6 the disk 40 , compressor blades 52 , and splitter blades 152 are depicted as an integral, unitary, or monolithic whole. This type of structure may be referred to as a “bladed disk” or “blisk”. The principles of the present invention are equally applicable to a rotor built up from separate components (not shown).
[0052] FIGS. 7-11 illustrate a portion of a rotor 238 constructed according to a second exemplary embodiment of the present invention and suitable for inclusion in the HPC 16 . As an example, the rotor 238 may be incorporated into one or more of the stages in the aft half of the HPC 16 , particularly the last or aft-most stage.
[0053] The rotor 238 includes a disk 240 with a web 242 and a rim 244 . It will be understood that the complete disk 240 is an annular structure mounted for rotation about the centerline axis 11 . The rim 244 has a forward end 246 and an aft end 248 . An annular flowpath surface 250 extends between the forward and aft ends 246 , 248 .
[0054] An array of compressor blades 252 extend from the flowpath surface 250 . Each compressor blade 252 extends from a root 254 at the flowpath surface 250 to a tip 256 , and includes a concave pressure side 258 joined to a convex suction side 260 at a leading edge 262 and a trailing edge 264 . As best seen in FIG. 10 , each compressor blade 252 has a span (or span dimension) “S 3 ” defined as the radial distance from the root 254 to the tip 256 , and a chord (or chord dimension) “C 3 ” defined as the length of an imaginary straight line connecting the leading edge 262 and the trailing edge 264 . Depending on the specific design of the compressor blade 252 , its chord C 3 may be different at different locations along the span S 3 . For purposes of the present invention, the relevant measurement is the chord C 3 at the root 254 .
[0055] The compressor blades 252 are uniformly spaced apart around the periphery of the flowpath surface 250 . A mean circumferential spacing “s” (see FIG. 9 ) between adjacent compressor blades 252 is defined as s=2πr/Z, where “r” is a designated radius of the compressor blades 252 (for example at the root 254 ) and “Z” is the number of compressor blades 252 . A nondimensional parameter called “blade solidity” is defined as c/s, where “c” is equal to the blade chord as described above. In the illustrated example, the compressor blades 252 may have a spacing which is significantly greater than a spacing that would be expected in the prior art, resulting in a blade solidity significantly less than would be expected in the prior art.
[0056] As seen in FIG. 9 , the flowpath surface 250 is depicted as a body of revolution (i.e. axisymmetric). Optionally, the flowpath surface 250 may have a non-axisymmetric surface profile as described above for the flowpath surface 250 .
[0057] The reduced blade solidity will have the effect of reducing weight, improving rotor performance, and simplify manufacturing by minimizing the total number of compressor airfoils used in a given rotor stage. An aerodynamically adverse side effect of reduced blade solidity is to increase the rotor passage flow area between adjacent compressor blades 252 . This increase in rotor passage through flow area increases the aerodynamic loading level and in turn tends to cause undesirable flow separation on the suction side 260 of the compressor blade 252 , at the inboard portion near the root 254 , and at an aft location, for example approximately 75% of the chord distance C 3 from the leading edge 262 , also referred to as “hub flow separation”. For any given rotor design, the compressor blade spacing may be intentionally selected to produce a solidity low enough to result in hub flow separation under expected operating conditions.
[0058] An array of splitter blades 352 extend from the flowpath surface 250 . One splitter blade 352 is disposed between each pair of compressor blades 252 . In the circumferential direction, the splitter blades 352 may be located halfway or circumferentially biased between two adjacent compressor blades 252 . Stated another way, the compressor blades 252 and splitter blades 352 alternate around the periphery of the flowpath surface 250 . Each splitter blade 352 extends from a root 354 at the flowpath surface 250 to a tip 356 , and includes a concave pressure side 358 joined to a convex suction side 360 at a leading edge 362 and a trailing edge 364 . As best seen in FIG. 11 , each splitter blade 352 has a span (or span dimension) “S 4 ” defined as the radial distance from the root 354 to the tip 356 , and a chord (or chord dimension) “C 4 ” defined as the length of an imaginary straight line connecting the leading edge 362 and the trailing edge 364 . Depending on the specific design of the splitter blade 352 , its chord C 4 may be different at different locations along the span S 4 . For purposes of the present invention, the relevant measurement is the chord C 4 at the root 354 .
[0059] The splitter blades 352 function to locally increase the hub solidity of the rotor 238 and thereby prevent the above-mentioned flow separation from the compressor blades 252 . A similar effect could be obtained by simply increasing the number of compressor blades 252 , and therefore reducing the blade-to-blade spacing. This, however, has the undesirable side effect of increasing aerodynamic surface area frictional losses which would manifest as reduced aerodynamic efficiency and increased rotor weight. Therefore, the dimensions of the splitter blades 352 and their position may be selected to prevent flow separation while minimizing their surface area. The splitter blades 352 are positioned so that their trailing edges 364 are at approximately the same axial position as the trailing edges 264 of the compressor blades 252 , relative to the rim 244 . This can be seen in FIG. 8 . The span S 4 and/or the chord C 4 of the splitter blades 352 may be some fraction less than unity of the corresponding span S 3 and chord C 3 of the compressor blades 252 . These may be referred to as “part-span” and/or “part-chord” splitter blades. For example, the span S 4 may be equal to or less than the span S 3 . Preferably for reducing frictional losses, the span S 4 is 50% or less of the span S 3 . More preferably for the least frictional losses, the span S 4 is 30% or less of the span S 3 . As another example, the chord C 4 may be equal to or less than the chord C 3 . Preferably for the least frictional losses, the chord C 4 is 50% or less of the chord C 3 .
[0060] The disk 240 , compressor blades 252 , and splitter blades 352 using the same materials and structural configuration (e.g. monolithic or separable) as the disk 40 , compressor blades 52 , and splitter blades 152 described above.
[0061] The rotor apparatus described herein with splitter blades increases the rotor hub solidity level locally, reduces the hub aerodynamic loading level locally, and suppresses the tendency of the rotor airfoil hub to want to separate in the presence of the non-axisymmetric contoured hub flowpath surface, or with a reduced airfoil count rotor on an axisymmetric flowpath. The use of a partial-span and/or partial-chord splitter blade is effective to keep the solidity levels of the middle and upper sections of the rotor unchanged from a nominal value, and therefore to maintain middle and upper airfoil section performance.
[0062] The foregoing has described a compressor rotor apparatus. All of the features disclosed in this specification (including any accompanying claims, abstract and drawings), and/or all of the steps of any method or process so disclosed, may be combined in any combination, except combinations where at least some of such features and/or steps are mutually exclusive.
[0063] Each feature disclosed in this specification (including any accompanying claims, abstract and drawings) may be replaced by alternative features serving the same, equivalent or similar purpose, unless expressly stated otherwise. Thus, unless expressly stated otherwise, each feature disclosed is one example only of a generic series of equivalent or similar features.
[0064] The invention is not restricted to the details of the foregoing embodiment(s). The invention extends any novel one, or any novel combination, of the features disclosed in this specification (including any accompanying claims, abstract and drawings), or to any novel one, or any novel combination, of the steps of any method or process so disclosed. | A compressor apparatus includes: a rotor having: a disk mounted for rotation about a centerline axis, an outer periphery of the disk defining a flowpath surface; an array of airfoil-shaped axial-flow compressor blades extending radially outward from the flowpath surface, wherein the compressor blades each have a root, a tip, a leading edge, and a trailing edge, wherein the compressor blades have a chord dimension and are spaced apart by a circumferential spacing, the ratio of the chord to the circumferential spacing defining a blade solidity parameter; and an array of airfoil-shaped splitter blades alternating with the compressor blades, wherein the splitter blades each have a root, a tip, a leading edge, and a trailing edge; wherein at least one of a chord dimension of the splitter blades at the roots thereof and a span dimension of the splitter blades is less than the corresponding dimension of the compressor blades. | 5 |
CROSS-REFERENCE
[0001] The invention described and claimed hereinbelow is also described in U.S. Provisional Patent Application 60/676,788, filed May 2, 2005, and also in European Patent Application No. 05009579.3, also filed May 2, 2005. The aforesaid US Provisional Patent Application, whose subject matter is incorporated here by reference, provides the basis for a claim of priority of invention under 35 U.S.C. 119 (e).
BACKGROUND OF THE INVENTION
[0002] The invention is a solid transdermal therapeutic system with UV absorber. The UV-stable transdermal therapeutic system (TTS) is particularly designed for photosensitive active pharmaceutical ingredients. It comprises a backing layer 1 , of at least one active ingredient-containing matrix 2 , and of a detachable protective film 3 . However an adhesive layer 4 and a separating layer 5 can optionally be introduced between the backing layer 1 and the active ingredient-containing matrix 2 . At least one hydroxyphenyltriazine acting as UV absorber can be embedded in the backing layer 1 , in the active ingredient-containing matrix 2 , or in the adhesive layer 4 .
[0003] Transdermal therapeutic systems, which contain a gestagen and/or an estrogen, are suitable for controlling fertility.
[0004] Attempts to employ photosensitive active ingredients, which absorb UV-A and UV-B rays, customarily used in sun creams, are known, as described by Briscart & Plaizier-Vercammen (Proc. 2 nd World Meeting on Pharmaceutics, Biopharmaceutics and Pharmaceutical Technology, APGI/APV, 1998, 1231-1232).
[0005] The patent literature further discloses the protection of transdermal therapeutic systems (TTS) provided with photosensitive active ingredients by visually conspicuous aluminized or lacquered covering films as backing layers of the TTS.
[0006] WO-A1-00/56289 describes a method for protecting therapeutic preparations, systems or their constituents, the intention being to achieve in each case specific protection from degradation by harmful factors, such as atmospheric oxygen, water, and/or light. Photo-protective substances, which absorb or reflect electromagnetic waves, are used, employing respectively absorbents or reflectants whose absorption or reflection spectrum covers the wave-length range responsible for the instability of the photosensitive substance or its constituents. Colored plastic films are used, inter alia, in this case as covering film, indicated by example of the 1,4-dihydopyridine derivative lacidipine.
[0007] The coloring of highly flexible plastic films proves to be difficult and does not provide reliable photo-protection owing to the frequently occurring fissures in the colored layer of the plastic film.
[0008] WO-A2-02/34200 further discloses transdermal therapeutic systems (TTS), which consist of an active ingredient-containing polymer matrix and of a backing layer. The polymer matrix and the backing layer are firmly connected or form a laminate. Both the polymer matrix and the backing layer comprise a colorless system, which absorbs in the UV range but has no intrinsic pharmacological effect. EP-A1-1452173 describes transdermal therapeutic systems, which consist of a backing layer, of at least one active ingredient-containing matrix and optionally of a detachable film and comprises a UV absorber. At least one UV absorber-containing adhesive layer is provided between the backing layer and the active ingredient-containing matrix furthest away from the surface of the skin. In addition, at least one separating layer, which is impermeable to active ingredient and impermeable to the UV absorber, is present between the adhesive layer containing the UV absorber and the active ingredient-containing matrix, which is furthest away from the surface of the skin. The UV absorber can be p-aminobenzoic acid, an aminobenzoic acid derivative, preferably 2-ethylhexyl 4-dimethyl-amino-benzoate and/or polyethoxyethyl 4-bis-(polyethoxyl)amino-benzoate, cinnamic acid, a cinnamic acid derivative, preferably isoamyl 4-methoxycinnamate or 2-ethylhexyl 4-methoxycinnamate, 3-benzylidenebornan-2-one, a benzylidene bornan-2-one derivative, preferably 3-(4′-methylbenzylindenebornan-2-one, 3-(4-sulphone)-benzylidenebornan-2-one, or 3-(4′-trimethylammonium)-benzylidenebornan-2-one methylsulphate, salicylic acid derivative, preferably 4-isopropylbenzyl salicylate, 2-ethylhexyl salicylate, or 3,3,3-trimethylcyclohexyl salicylate, a benzotriazole, preferably 2-(5-chloro-2H-benzotriazol-2-yl) -6-(1,1-dimethylethyl)-4-methylphenol, 3-imidazol-4-yl-acrylic acid, 3-imidazol-4-yl-3-imidazol-4-yl-acrylic ester, 2-phenylene benzimidazole-5-sulphonic acid, or its K, Na and triethanolamine (=TEA) salt, 2-cyano-3,3-diphenylacrylic acid, terephthaloylidene-dicamphorsulphonic acid, butylmethoxy-dibenzoylmethane, benzophenone, or a benzophenone derivative, preferably benzophenone-3 or benzophenone-4.
[0009] The known solutions have the disadvantage
that the protective effect produced by the added UV absorber for the active ingredient is incomplete, that owing to the incomplete protective effect in some cases higher concentrations of UV absorbers must be employed, which may have adverse effects on the compatibility of the TTS with skin.
SUMMARY OF THE INVENTION
[0012] It is therefore an object of the invention to provide a pharmaceutical preparation of the above-described kind with a UV absorber, which is provided with a photosensitive active ingredient, which is to be transdermally administered, and which ensures an increased protective effect for the active ingredient while using a minimum UV absorber concentration, so that the aforementioned disadvantages are avoided.
[0013] This object is achieved according to the invention by a solid transdermal therapeutic system (TTS) with a UV absorber, wherein the UV-stable TTS comprises a sequence of at least three layers, namely a backing layer 1 , at least one active ingredient-containing matrix 2 , and a detachable protective film 3 . Optionally an adhesive layer 4 and a separating layer 5 can be introduced between the backing layer 1 and the at least one active ingredient-containing matrix 2 . In the transdermal therapeutic system according to the invention the UV absorber comprises at least one hydroxyphenyltriazine compound and the UV absorber is embedded in the backing layer 1 , in the active ingredient-containing matrix 2 , or in the adhesive layer 4 .
BRIEF DESCRIPTION OF THE DRAWING
[0014] The objects, features and advantages of the invention will now be illustrated in more detail with the aid of the following detailed description and examples of the invention, with reference to the accompanying figures, in which:
[0015] FIG. 1 is a graphical illustration showing the percentage of photosensitive active ingredient remaining in a transdermal therapeutic system according to the invention with photo-protective features and the percentage of photosensitive active ingredient remaining in a comparative transdermal therapeutic system; and
[0016] FIGS. 2 to 4 are respective diagrammatic cross-sectional views through various embodiments of the transdermal therapeutic systems according to the invention.
DETAILED DESCRIPTION OF THE INVENTION
[0017] In a preferred embodiment according to the invention the UV absorber is 2,4-bis-([4-(2′-ethylhexyloxy)-2-hydroxy]phenyl)-6-(4-methoxyphenyl)-(1,3,5)-triazine.
[0018] In various embodiments of the transdermal therapeutic systems according the weight per unit area of the matrix 2 is from 30 to 150 g/m 2 . In this connection, a weight per unit area of from 50 to 120 g/m 2 is preferred, and of 100 g/m 2 is particularly preferred.
[0019] Similarly in various embodiments of the solid transdermal therapeutic system according to the invention the weight per unit area of the adhesive layer 4 is from 5 to 50 g/m 2 . In this connection, a weight per unit area of from 20 to 30 g/m 2 is preferred.
[0020] The UV absorber can be present according to the invention in the adhesive layer 4 in a concentration of from 0.5 to 5% (m/m) in dissolved form. In this connection, a concentration of from 1.0 to 4.0% is preferred, and of from 1.5 to 3.0% is particularly preferred.
[0021] Furthermore the matrix 2 and/or the adhesive layer 4 in the solid transdermal therapeutic system can be designed according to the invention to be self-adhesive and can consist substantially of polymers, which are selected from the group consisting of polyisobutylene, polybutene, polyacrylate, polydimethylsiloxane, styrene-isoprene block polymer and polyisoprene.
[0022] Preferred embodiments of the solid transdermal therapeutic systems according to the invention have a separating layer thickness of from 4 to 23 μm. In this connection, a layer thickness of from 4 to 10 μm is preferred.
[0023] In the solid transdermal therapeutic systems according to the invention the separating layer 5 is preferably impermeable to the active ingredient and impermeable to the UV absorber.
[0024] In preferred embodiments of the invention the separating layer 5 can consist of a barrier polymer. Preference is given in this connection to polyethylene terephthalate, polyacrylonitrile, polyvinyl chloride, polyvinylidene chloride, or its copolymers or co-laminates.
[0025] In preferred embodiments of the solid transdermal therapeutic system according to the invention the backing layer 1 is permeable to active ingredient and consists of polypropylene, of polyethylene, of polyurethane, of ethylene-vinyl acetate copolymer, or of a multilayer composite of these materials with one another or with other materials.
[0026] The UV absorber(s) in the solid transdermal therapeutic system according to the invention can be colorless or yellowish.
[0027] It is furthermore possible for the solid transdermal therapeutic system according to the invention to be transparent or slightly opaque.
[0028] The active ingredient in the solid transdermal therapeutic system according to the invention can be at least one hormone.
[0029] The active pharmaceutical ingredient according to the invention can be a progestogen, preferably gestodene or levonorgestrol. Furthermore an estrogen, preferably ethinyl estradiol, can be added to the progestogen in the solid transdermal therapeutic system according to the invention.
[0030] According to the invention the solid transdermal therapeutic system can also be used to control fertility.
[0031] It is also possible according to the invention for the solid transdermal therapeutic system to be equipped without a membrane controlling active ingredient release.
[0032] The transdermal therapeutic system according to the invention has the following advantages compared with conventional systems with photosensitive active ingredient content.
The protective effect provided by the hydroxyphenyltriazine compounds acting as UV absorber is enhanced. The concentration of the hydroxyphenyitriazine compounds acting as UV absorber, which is necessary to achieve a protective effect is reduced. It is thus possible in particular to avoid or reduce the risk of possible skin irritation.
[0036] The invention is further illustrated and explained by the following examples.
EXAMPLE 1
[0037] Two formulations (1 and 2) of a photosensitive active ingredient from the progestogens were prepared. Formulation 2 comprises an adhesive layer 4 and a separating layer 5 , and the adhesive layer comprises 2.5% by weight of a UV-absorbing substance from the hydroxyphenyltriazine compounds. Formulation 1 has no adhesive layer and no separating layer. Formulation 1 serves as comparative formulation. Both formulations comprise an active ingredient-containing matrix 2 with a photosensitive progestogen and are equipped with a backing layer 1 of polyethylene, resulting in a TTS in each case. Formulation 2 has the following composition:
1. Active ingredient-containing matrix:
1.9% progestogen 98.1% polyisobutylene-based adhesive;
2. Adhesive layer:
3% Tinosorb® S 97% polyisobutylene-based adhesive.
Tinosorb® S (from Ciba, Lampertheim) is a UV absorber of the hydroxyphenyltriazine class.
[0044] To investigate the photo-protective effect, both formulations were irradiated with light having a UV spectrum of 300-800 nm for a period of up to 34 h. The radiation source used was a xenon lamp. A filter system (type: Suprax® filter) was placed between the radiation source and the samples to be irradiated in order to simulate irradiation under realistic conditions of use of the TTS. The active ingredient content in the TTS after irradiation was then determined.
[0045] FIG. 1 reveals that the TTS of formulation 2, which comprised an adhesive layer with UV-absorbing substance and a separating layer, still comprised about 95% of the originally employed amount of the photosensitive active ingredient after irradiation for 34 h, whereas the TTS of formulation 1 comprised only about 3% of the originally employed amount of the photosensitive active ingredient after irradiation.
[0046] The system according to the invention has improved protection from the sun under realistic conditions-of-use, since the UV-protective effect of the system according to the invention (formulation 2) was considerably greater than that of the comparative system (formulation 1).
EXAMPLE 2
[0047] The formulations of example 2 have a photosensitive active ingredient from the progestogens, and in each case an adhesive layer and separating layer. The separating layer in each of these formulations consists of polyethylene terephthalate (Hostaphan® 1 from Mitsubishi Polyester, Wiesbaden). Each formulation has the following composition:
1. Active ingredient-containing matrix
1.9% progestogen 98.1% polyisobutylene-based adhesive;
2. Adhesive layer 1 and 2 :
2.5% Tinosorb® S 97.5% polyacrylate-based adhesive.
EXAMPLE 3
[0054] The formulations of example 3 have a photosensitive active ingredient from the progestogens, and in each case two adhesive layers and separating layers. The separating layers in each case consist of polyethylene terephthalate (Hostaphan® 1 from Mitsubishi Polyester, Wiesbaden). These formulations each have the following composition:
1. Active ingredient-containing matrix:
1.9% progestogen 98.1% polyisobutylene-based adhesive;
2. Adhesive layer 1 and 2 :
3% Tinuvin®400 97% polyacrylate-based adhesive.
Tinuvin®400 (from CIBA, Lampertheim) is a UV absorber of the hydroxyphenyltriazine class.
EXAMPLE 4 TO 12
[0061] The formulations of example 4 have a photosensitive active ingredient from the progestogens, and in each case at least one adhesive layer and separating layer. In these formulations in which the active ingredient-containing matrix is embodied analogous to examples 1 to 3 and the adhesive layer comprises a poly-isobutylene-based adhesive and has the compositions mentioned below.
[0000]
Composition of the adhesive
Example
layer
4
5
6
7
8
9
10
11
12
Tinosorb ® S [%]
2
2
2
3
3
3
4
4
4
Polyisobutylene-based
98
98
98
97
97
97
96
96
96
adhesive [%]
Weight per unit area [g/m 2 ]
20
30
50
20
30
50
20
30
50
EXAMPLE 13 TO 21
[0062] The formulations of examples 13 to 21 have a photosensitive active ingredient from the progestogens, and in each case at least one adhesive layer and separating layer. The active ingredient-containing matrix is embodied analogously to examples 1 to 3, and the adhesive layer comprises a polyacrylate-based adhesive and has the compositions mentioned below.
[0000]
Composition of the
Example
adhesive layer
13
14
15
16
17
18
19
20
21
Tinosorb ® S [%]
2
2
2
3
3
3
4
4
4
Polyacrylate-based
98
98
98
97
97
97
96
96
96
adhesive [%]
Weight per unit area [g/m 2 ]
20
30
50
20
30
50
20
30
50
[0063] While the invention has been illustrated and described as embodied in a solid transdermal therapeutic system with UV absorber, it is not intended to be limited to the details shown, since various modifications and changes may be made without departing in any way from the spirit of the present invention.
[0064] 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. | The UV-stable solid transdermal therapeutic system (TTS) with UV absorber for photosensitive active pharmaceutical ingredients has a backing layer ( 1 ), at least one active ingredient-containing matrix ( 2 ), and a detachable protective film ( 3 ). Optionally an adhesive layer ( 4 ) and a separating layer ( 5 ) are introduced between the backing layer ( 1 ) and the at least one active ingredient-containing matrix ( 2 ). At least one hydroxyphenyltriazine compound acting as UV absorber is embedded in the backing layer ( 1 ), in the active it matrix ( 2 ), or in the adhesive layer ( 4 ). The TTS according to the invention achieves high stability at low concentrations of UV absorber, preferably 0.5 to 3% (m/m), so as to reduce or avoid skin irritation. | 0 |
This application is a division of application Ser. No. 07/526,857 filed May 21, 1990, now U.S. Pat. No. 5,101,639.
BACKGROUND OF THE INVENTION
The present invention pertains to heating, ventilating and air conditioning (HVAC) systems in general, and to an air handling unit arrangement in which a direct expansion coil is utilized.
In some buildings, typically high rises, it is common to use one or more small air handling units per floor. These systems have the advantages of being inexpensive to purchase and install and a self-contained system may be provided for each tenant. For example, each floor of a high-rise building may therefore have one or more small air handling units.
Such systems are characterized by recurring problems related to equipment failure and occupant discomfort. The recurring equipment problems can be identified as being related to icing of the expansion coil and cooling compressor seizure.
The occupant discomfort problems typically are associated with wide variations in temperature due to compressor cycling and excessive removal of moisture from the air.
SUMMARY OF THE INVENTION
In accordance with the invention the foregoing and other problems associated with air handling systems are advantageously solved in an improved method and apparatus.
In accordance with one aspect of the invention, predictive algorithms are employed in a controller to avoid icing of the cooling coil, avoid compressor seizure by eliminating the possibility for certain modes of compressor operation from occurring and to maintain occupant comfort levels.
Another aspect of the invention is the control of variable air volume boxes by the controller in order to improve the comfort level in an occupied space. The controller, for small changes in space temperature requiring only a small cooling load, is programmed to change the air flow into the space, rather than cycle the compressor.
A further aspect of the present invention is the control of cooling agent flow to the condenser by the controller. For small changes in cooling load requiring only a small portion of cooling capacity, the controller is programmed to increase the load o the compressor by restricting a valve which controls cooling agent flow from a cooling tower to the condenser.
Yet another aspect of the invention is the artificial loading of the compressor by causing warm water leaving the condenser to flow through a pre-cool coil which is upstream in the air flow from the direct expansion coil.
BRIEF DESCRIPTION OF THE DRAWING
The invention will be better understood from a reading of the following detailed description in conjunction with the drawing in which like reference characters designate like drawing elements and in which:
FIG. 1 is a schematic drawing of a conventional air handling system of the type to which the present invention may advantageously be applied;
FIG. 2 is a schematic drawing of the system of FIG. 1 illustrating the use of self-contained diffusers;
FIG. 3 is a schematic drawing of an improved air handling system in accordance with the present invention;
FIG. 4 illustrates in block diagram form a controller of the type which may be advantageously employed in the system of FIG. 3;
FIG. 5 is a flow diagram of cooling operation; and
FIG. 6 is a flow diagram heating and cooling operation.
DETAILED DESCRIPTION
FIG. 1 illustrates a typical prior art air handling system in which a fan 1 supplies cooled air to a distribution system 2 which may include one or more zone terminals. Each zone terminal may in turn have a variable air volume (VAV) terminal 3 with one or more diffusers 4, or it may have a self-contained diffuser 41, i.e., a diffuser with self-contained controls), as shown in FIG. 2. FIGS. 1 and 2 are identical except for the use of self-contained diffusers in place of VAV's. The following discussion applies equally to FIGS. 1 and 2. Each zone terminal regulates the flow of air into a space to control cooling level and maintain occupant comfort based upon dry bulb temperature in the space.
Air is supplied to the fan primarily by means of return air and a fixed quantity of outside air. The return air flows through return duct 5. Building codes typically require a minimum outside, i.e., fresh air supply. In the illustrative system, the minimum outside air required by building code is supplied via outside air plenum 6.
The air is cleaned by means of filter 7 and passes through a precool coil 8. Precool coil 8 is required under certain building codes for energy conservation and uses cooling water supplied from a cooling tower 9 to provide so called "free cooling" from outside ambient air without the use of a compressor. From precool coil 8, the air flows through a direct expansion coil 10 which is coupled to a compressor 11 via an expansion valve 13. Compressor 11 in turn is coupled to a water cooled condenser 12. Condenser 12 receives a cooling agent, such as cooling water from cooling tower 9.
A controller 14 measures the discharge air temperature from the direct expansion coil 10 via a temperature sensor 17 and controls the output of compressor 11 by cycling compressor 11 on or off. It should be noted that although only one compressor is shown, two or more compressors may be coupled to controller 14. Controller 14 also controls the flow of cooling water to condenser 12 and to coil 8 via three way, two position valve 15 and flow valve 16, respectively.
Condenser 12 contains an internal control valve which monitors the compressor head pressure and varies the water flow to maintain a head pressure set point. The valve opens and closes to maintain the preset compressor head pressure.
Controller 14 is typically an electromechanical controller of a type well known in the art and is of a relatively simple construction, The purpose of controller 14 is to attempt to maintain a constant discharge air temperature, typically 55° F. from the direct expansion coil 10.
In operation, the fan 1 typically runs continuously and either coil 8 or direct expansion coil 10 is used to provide cooling of air. If the cooling water temperature in the supply line from the water tower is at or less than a predetermined temperature, the controller will turn off compressor 11, operate valve 15 to divert water flow from condenser 12 to coil 8 and operate valve 16.
As pointed out briefly above, this prior art arrangement has some significant problems. These problems are icing of the direct expansion coil, compressor seizure or occupant discomfort.
Icing of the direct expansion coil 10 may occur as a result of a low load condition. A direct expansion cooling system is inherently limited in its ability to throttle cooling capacity. Because of this, cooling is limited to discrete capacity steps. As the cooling load drops below the minimum throttling capacity of the cooling stage, icing of the coil 10 occurs.
It has also been determined that loose fan belts or dirty filters can result in icing of the coil 10. In all three cases the air flow through the coil 10 is reduced and the result may be icing.
Additionally, if valves 15 and 16 stay open such that cooling water always flows to coil 8, the load on the direct expansion coil 10 is reduced. If condenser 12 cooling water valve (controlled by head pressure) sticks open, this can lead to compressor failure. This condition will cause excessive compressor cycling due to automatic safety cutouts. A stuck condenser cooling valve can result in the condenser cooled to a lower temperature than the direct expansion coil. These conditions result in oil migration from the compressor, seizure and permanent failure. Valves 15 and/or 16 commonly stick open as a result of scale or dirt build up in the valves resulting from the use of water which flows directly from cooling tower 9.
Compressor failure as evidenced by compressor seizure may result from several causes. If the compressor cycles too often in a given time period, the resulting high pressure differential in the compressor may result in seizure. A controller 14 determines the number of cycles that it will initiate in a given time period as a function of a manual setting. Very often this cycle rate will be increased by maintenance personnel to resolve occupant discomfort. The actual number of cycles may be more than the controller setting. A reason for this is if the compressor begins overheating the temperature limit switch in the compressor opens up. This limit switch cycle may repeat multiple times during a single on cycle from controller 14.
Turning now to FIG. 3, the improved system in accordance with the invention is shown. In the improved system the cooling water passes through a heat exchanger 9a. The heat exchanger protects valves 15 and 16 from dirt and scale. Controller 14 of the prior system is replaced with a programmable controller 141 which will be described in further detail below. A temperature sensor 31 is connected to measure the temperature of the cooling water from the cooling tower. A pressure sensor 32 is provided to measure the air pressure downstream of the direct expansion coil 10. Alternatively, a pressure sensor 33 may be provided downstream of fan 1. Another pressure sensor 34 is provided downstream of the coil 10. In addition, a status sensor 35 is provided at compressor 11. The status sensor may be of any conventional type which would indicate whether the compressor 11 is energized and running or not. The sensors 32, 33 and 34 may be any conventional air pressure sensor. Likewise tower water sensor 31 may be any conventional temperature sensor. Also connected into the controller but not shown is one or more temperature sensors which measure the temperature in the spaces in the building which are to be controlled.
As was noted above, one problem associated with direct expansion cooling based air handling units in the past has been icing of the direct expansion coil. In accordance with the present invention, the coil resistance to air flow is measured. The controller 141 does this by calculating the pressure differential between pressure sensors 34 and 32 or 34 and 33 and determining air flow through the DX using air flow sensor 17. The controller then determines if the DX coil is iced by looking in a look up table stored in memory at an address determined from the air flow. If the pressure drop is greater than the value stored at the selected address, the controller determines that the DX coil is iced. If as a result of that comparison it is determined that the coil is iced, the controller will turn off the compressor and deice the coil. Meanwhile, the controller will continue to measure the pressure on either side of the coil 10 by means of pressure sensors 34 and 32 or 33. When the pressure differential drops to a level which is indicative of a deiced coil, the controller then permits the compressor to be turned on again if cooling is called for.
In addition, the controller can operate to determine whether or not there is a probability that a filter 7 is dirty and needs replacement or if the belt driven fan 1 has a loose belt. In either of those situations reduced air flow occurs which may be sensed by the sensors 32, 34 and 33. Depending upon the signature of the reduced air flow it may be determined whether the air flow reduction is due to a dirty filter, icing of the coil or a loose belt. Under each of those circumstances, the time period over which the air flow reduces will be different. The controller 141 can calculate the time rate of change in the air pressure and compare that time rate of change with data stored in the controller memory to determine whether there is icing of the coil, a loose belt or a dirty filter.
Compressor seizure may occur from excessive cycling. In accordance with the invention the status of the compressor is monitored or measured by means of sensor 35. Sensor 35 can, for example, monitor the current flow to the compressor and thereby determine whether or not the compressor is running. Controller 141 monitors the number of compressor cycles and will not allow the compressor to be activated if the compressor has reached a predetermined upper limit of cycles in a given period of time, i.e., an hour. With this arrangement, should a compressor cycle too many times in an hour, due, for example, to the thermal overload switch being tripped in the compressor, then the controller will not allow a manual override to cause the compressor to be operated. Furthermore, a diagnostic message may be generated by the controller 141 to let the system or building operator know that there is a potential problem.
Controller 141 can also calculate the load imposed on the fan system by utilizing the pressure sensors to measure the air flow and by measuring the temperature differential across the system. By using predictive techniques, increasing the discharge air temperature setpoint will increase the air flow across the direct expansion coil 10. The increased air flow will prevent icing on direct expansion coil 10.
The controller 141 also may be used to maintain the condenser pressure at the lowest allowed level to not only avoid compressor seizure but to provide for energy savings.
Controller 141 also can avoid a change over from use of the precoil 8 to compressor cooling at low loads. If the water temperature as measured by sensor 31 indicates that the temperature of cooling tower water reaches a level at which cooling tower water cannot provide adequate cooling and the compressor only has a relatively low load, then the flow versus temperature difference may be used to maintain a higher level temperature in the controlled space with a higher air flow. In other words, the discharge temperature from the fan would be allowed to float and the compressor would be turned on only when the cooling load is above a predetermined threshold level (e.g. 10-15% of cooling capacity). With this arrangement an intelligent decision is made to try to maintain occupant comfort within a particular comfort band, but if it is needed to save the equipment, the controller 141 will cause the system to operate such that it operates at the higher end of the comfort band. This is of course different than prior art systems in which there was no provision for automatic override of, for example, temperature sensors.
Controller 141 also operates to prevent compressor seizure by artificially loading the compressor during low load conditions. More specifically, under low load conditions, controller 141 may energize valves 15 and 16 such that the precool coil 8 is used as a preheater to increase the load on the compressor under low load conditions. As an additional strategy, controller 141 may use the valve 15 to decrease water flow through the condenser and to increase the new pressure thereby increasing the load on the compressor.
Turning now to the aforementioned problem of occupant discomfort, the use of multiple VAV boxes 3a eliminates wide variations in temperature by maintaining the manufacturers recommended cycle rate of the compressor as discussed above and by maintaining a cooling load by changing the zone terminal air flow rate as a result of fan discharge air temperature variation. Additionally, occupant discomfort due to dehumidification is minimized by utilizing controller 141 to maintain the proper balance between air flow rate and temperature differential to maintain the smallest temperature difference across the direct expansion coil 10. Turning now to FIG. 4, a representative controller is shown. Controller 141 includes CPU 441 of a type well known in the art, a random access memory (RAM) 42 which may be any conventionally available random access memory, a read only memory (ROM) 43 which contains the various data necessary for operation of the system and an IO or input/output interface 44. The IO interface 44 provides a buffer between the CPU and the various sensors and control points of the system. As is well known, such a device will include circuitry for providing appropriate voltage and/or current interface to the various sensors and to the various control devices such as valves 15 and 16 and for control of the compressor 11. Each and every one of the elements of FIG. 4 is well known. The controller 141 may in its totality be purchased from Honeywell Inc. as Honeywell's MICROCEL system controller.
Occupant discomfort and equipment failures can be traced to the performance of the central fan direct expansion cooling system under low load conditions. The system is inherently limited in its ability to throttle cooling capacity. In addition, cooling air is limited to discrete temperature steps. Low load conditions can result in fan coil icing as the cooling load drops below the minimum throttling capacity of the first cooling stage. Coil icing may lead to compressor failure or simply starve the air flow causing occupant discomfort.
Since direct expansion cooling is a staged process, the central fan discharge air temperature will cycle under less than full load conditions. Conventional VAV zone terminal control loops are not configured to compensate for rapid changes in the cooling supply air temperature. The response of a space temperature control loop is dominated by a time constant on the order of 12 minutes. This sluggish response results in unstable control of the space temperature and occupant discomfort.
The attached control diagrams shown in FIGS. 5 and 6 describe a zone terminal control which compensates for rapid variations in the central fan supply air temperature. Conventional zone VAV controllers use a similar cascade control loop with the output of the space temperature controller directly resetting the VAV flow control set point. The proposed strategy is different because it incorporates feed forward compensation for disturbances in the cooling air temperature.
A space temperature controller determines the amount of cooling or heating energy required (Q req ) to maintain a comfortable room temperature. As the space temperature PI controller output varies from 0 to 100, this signal is converted to the space energy required Q req to maintain occupant comfort.
Q.sub.req =Q.sub.clgdsgn +(Control.sub.output *(Q.sub.htgdsgn -Q.sub.clgdsgn)/100
where ##EQU1## and Q req is the required heat transfer to the conditioned space. Control out is the output of the space temperature controller.
For zone design cooling load:
Q.sub.clgdsgn =1.1 F.sub.max (T.sub.supclg -T.sub.spacemax)
where: T supclg is the design cooling supply temperature.
T spacemax is the design cooling season space temperature.
F max is zone terminal design maximum air flow. For zone design heating load:
Q.sub.htgdsgn =1.1 F.sub.min ×(T.sub.suphtg -T.sub.spacemin)
where: T suphtg is the design discharge air temperature of the air VAV box reheat coil. T spacemin is the design heating season space temperature.
Fmin is zone terminal design minimum air flow. If the zone terminal is cooling only, Q htgdsgn =0
The VAV flow controller setpoint is calculated based on the required space heat transfer, current supply air temperature as well as the space temperature.
F=Q.sub.req /1.1*(T.sub.sup -T.sub.s)
where F is the flow set point, T sup is the supply air temperature and T s is the space temperature.
Variations in the central fan supply air temperature will immediately affect the air flow distributed to the occupied space. An increase in fan supply temperature increases air flow while a decrease results in lower air flow. In all cases, the inner loop will attempt to maintain the space heat transfer dictated by the outer loop space temperature controller. Of course the VAV terminal air flow setpoint range is restricted between the minimum and maximum air flow limits.
Reheat coils located in a VAV terminal are controlled with a calculated heating discharge air temperature setpoint htg setpt .
IF Q req =0
THEN the Q htgsetpt =(Q req /1.1*F)+T
IF Q req >0
THEN heating off
Zones installed with heating convectors or radiators may use the Q req signal directly from the space temperature controller.
FIG. 5 and FIG. 6 illustrate the system and controller operation in a flow chart form. FIG. 5 illustrates the control of the VAV's boxes 3 in FIG. 3 for cooling only whereas FIG. 6 illustrates the flow control for heating and cooling with zone VAV's.
In FIG. 5, summer 505 creates an error signal as the difference between a user selected space temperature setpoint and the actual space temperature (T s ) signal produced by space temperature sensor 555. This error signal is then provided to a space temperature PI controller 510. The PI controller in turn produces a control out signal which is based on a first fraction of the error signal and a second fraction of the integral of the error signal. PI controllers are well known in the art, as are the methods of selecting the first and second fractions depending upon the control desired.
Once the Control out Q signal has been determined, the required heat transfer, Q req must be calculated, as shown in box 515. Once the Q req is calculated, the required air flow, F 1 into the space being controlled can be determined, as shown in box 520. Since F is dependent upon the space temperature T s and the supply air temperature T sup , block 520 is shown as receiving T s and T sup from space temperature sensor 555 and supply air temperature sensor 550. Once F is calculated, it is compared with actual flow (F act ) signal produced by air flow sensor 545. The difference is calculated by summer 525 and provided to terminal controller 530. Note that summers 505 and 525, PI controller 510 and blocks 515 and 520 are all parts of controller 3a.
Terminal controller 530 in turn responds to the difference signal provided to it. It also is a PI controller which operates in a manner similar to space temperature controller 510. Terminal controller produces a flow control signal which is then sent to damper 535. Damper 535 controls the amount of air flow into occupied space 540.
As we stated earlier, the system shown in FIG. 6 is basically the same as the system shown in FIG. 5, except that the system shown now includes elements so that a space can be heated as well as cooled. Block 520' now has two algorithms, one for heating and one for cooling. The heating algorithm is elected when Q req >0 and the cooling algorithms is selected when Q req <0. Note that for convenience, supply air temperature sensor 550 is shown twice although only one sensor is used.
Turning now to FIG. 6, four new parts have been added to the system of FIG. 5 so that heating may be accomplished. Block 522 creates a heating setpoint signal as a function of Q req , F act and T s ;. Summer 565 then adds T sup and heating setpoint to create a heating error signal. Both blocks 522 and summer 565 are additional blocks of controller 141 in a system which can heat as well as cool.
The heating error signal is then provided to a heating P controller. The heating P controller multiplies the error signal by a predetermined fraction to produce a heating control signal for heating coil 560. Heating coil 560 in turn heats up air passing through the damper into the occupied space.
In all other aspects, the system shown in FIG. 6 is the same as the system of FIG. 5.
The foregoing has been a description of a novel and non-obvious control system for HVAC systems. The embodiments described herein are not intended to limit the scope of the inventors property rights as defined by the appended claims. | A system for controlling the operation of an HVAC system which includes a direct expansion coil, a condenser, a pre-cool coil, and a control system. The control system includes a controller and sensors. The controller receives signals indicative of air flow through the direct expansion coil from the sensors, compares the received signal to a stored air flow rate, and disables the compressor if the stored air flow rate is equal to or greater than the stored value. The controller is also adapted to vary air flow into an occupied space for small changes in the cooling load. In addition, the controller can artificially load the compressor during periods of small cooling load by restricting flow of a cooling agent between the cooling tower and the condenser, or by directing warm water from the condenser through the pre-coil coil. | 5 |
TECHNICAL FIELD
[0001] The present disclosure relates to a semiconductor integrated circuit device entering into, during and coming out of a low power mode, and more particularly, to maintaining the input and/or output configuration and data state(s) during and when the semiconductor integrated circuit device comes out of the low power mode.
BACKGROUND
[0002] Integrated circuit devices are being fabricated with decreasing transistor geometry sizes that result in increased leakage currents during operation thereof. One solution to reducing leakage currents when operation of the integrated circuit device is not required is to shut down and/or remove power from some or most of the transistor logic circuits of the integrated circuit device. This puts the transistor logic circuits of the integrated circuit device into a “low power mode” that substantially reduces the power requirements of the integrated circuit device during extended standby conditions.
[0003] With current architecture implementations of a low power mode in an integrated circuit device, exiting from the low power mode is similar to performing a power-on reset (POR) of the integrated circuit device. While the internal logic states of the integrated circuit device may be woken-up and restored by software and/or firmware, it is important to keep the interaction between the integrated circuit device and other devices in an electronic system that are connected to the integrated circuit device static so as to avoid disturbing the system, and thereby causing unintended actions in and/or by the electronic system.
[0004] Through the use of standard input-output (I/O) “keeper” cells, the I/O control and data states of the outputs of the integrated circuit device (during the low power mode) may be retained so as not to upset operation of the other devices in the electronic system. However, upon waking from a low power mode, the I/O control and data states may be reset into a default reset state, e.g., logic 0, logic 1, or unknown, thereby possibly disturbing operation of the other devices in the electronic system. Thus, unintended actions may result to the other devices connected to the integrated circuit device when the integrated circuit device comes out of the low power mode.
SUMMARY
[0005] Therefore what is desired is a way upon exiting a low power mode, to re-initialize logic circuits and/or wake-up and restore logic states of any internal registers (if necessary), and re-establish the desired I/O configuration control and data states without distributing the operation of other devices in an electronic system. According to teachings of this disclosure, a “low power mode wake-up and restore” signal, e.g., a bit that may be set or reset by software, may be used to indicate to the I/O keeper cells to stop overriding the I/O configuration control and data states previously stored when the integrated circuit device entered into the low power mode.
[0006] According to a specific example embodiment of this disclosure, an integrated circuit integrated circuit device having a low power mode and a maintained input-output (I/O) configuration and data states may comprises: a plurality of logic circuits; and an input-output (I/O) node coupled to the plurality of logic circuits, the I/O node comprises an I/O keeper cell coupled to a driver and a receiver; wherein when the I/O keeper cell receives an enter low power mode signal the I/O keeper cell will maintain the driver data state and I/O configuration thereof; and wherein when the I/O keeper cell receives a wake-up and restore from low power mode signal the I/O keeper cell returns control of the driver data state and I/O configuration to the plurality of logic circuits.
[0007] According to another specific example embodiment of this disclosure, an integrated circuit integrated circuit device having a low power mode and a maintained output configuration and data state may comprise: a plurality of logic circuits; and an output node coupled to the plurality of logic circuits, the output node comprises an output keeper cell coupled to a driver; wherein when the output keeper cell receives an enter low power mode signal the output keeper cell will maintain the driver data state and output configuration thereof; and wherein when the output keeper cell receives a wake-up and restore from low power mode signal the output keeper cell returns control of the driver data state and output configuration to the plurality of logic circuits.
[0008] According to yet another specific example embodiment of this disclosure, an integrated circuit integrated circuit device having a low power mode and a maintained input configuration and data state may comprise: a plurality of logic circuits; and an input node coupled to the plurality of logic circuits, the input node comprises an input keeper cell coupled to a receiver; wherein when the input keeper cell receives an enter low power mode signal the input keeper cell will maintain the receiver data state and input configuration thereof; and wherein when the input keeper cell receives a wake-up and restore from low power mode signal the input keeper cell returns control of the receiver data state and input configuration to the plurality of logic circuits.
[0009] According to still another specific example embodiment of this disclosure, a method of maintaining input-output (I/O) configuration and data states during and when coming out of a low power mode in an integrated circuit device, said method may comprise the steps of: entering into a low power mode for logic circuits of the integrated circuit device; retaining input-output (I/O) configuration and data states in a keeper cell; controlling the I/O configuration and the data states from the keeper cell; restoring the logic circuits from the low power mode; exiting the low power mode; and returning control of the I/O configuration and data states to the logic circuits.
[0010] According to another specific example embodiment of this disclosure, a method of maintaining input-output (I/O) configuration and data states during and when coming out of a low power mode in an integrated circuit device may comprise the steps of: detecting assertion of an enter low power mode command; entering into a low power mode for logic circuits of the integrated circuit device when the enter low power mode command is detected; retaining input-output (I/O) configuration and data states in a keeper cell; controlling the I/O configuration and the data states from the keeper cell; restoring the logic circuits from the low power mode; detecting assertion of a wake-up and restore from low power mode command; exiting the low power mode when the wake-up and restore from low power mode command is detected; and returning control of the I/O configuration and data states to the logic circuits.
BRIEF DESCRIPTION OF THE DRAWINGS
[0011] A more complete understanding of the present disclosure thereof may be acquired by referring to the following description taken in conjunction with the accompanying drawings wherein:
[0012] FIG. 1 illustrates a schematic block diagram of an input-output (I/O) node having an I/O keeper cell in an integrated circuit device, according to a specific example embodiment of this disclosure;
[0013] FIG. 2 illustrates a schematic block diagram of an output node having an output keeper cell in an integrated circuit device, according to another specific example embodiment of this disclosure;
[0014] FIG. 3 illustrates a schematic block diagram of an input node having an input keeper cell in an integrated circuit device, according to yet another specific example embodiment of this disclosure;
[0015] FIG. 4 illustrates a schematic operational flow diagram of an integrated circuit device entering into and returning from a low power mode, retention of data states and I/O configurations of an input-output (I/O) node of the integrated circuit device, according to a specific example embodiment of this disclosure; and
[0016] FIG. 5 illustrates a schematic operational flow diagram of an integrated circuit device entering into and returning from a low power mode under software control and retention of data states and I/O configurations of an input-output (I/O) node of the integrated circuit device, according to another specific example embodiment of this disclosure.
[0017] While the present disclosure is susceptible to various modifications and alternative forms, specific example embodiments thereof have been shown in the drawings and are herein described in detail. It should be understood, however, that the description herein of specific example embodiments is not intended to limit the disclosure to the particular forms disclosed herein, but on the contrary, this disclosure is to cover all modifications and equivalents as defined by the appended claims.
DETAILED DESCRIPTION
[0018] Referring now to the drawings, the details of specific example embodiments are schematically illustrated. Like elements in the drawings will be represented by like numbers, and similar elements will be represented by like numbers with a different lower case letter suffix.
[0019] Referring to FIG. 1 , depicted is a schematic block diagram of an input-output (I/O) node having an I/O keeper cell in an integrated circuit device, according to a specific example embodiment of this disclosure. An integrated circuit device 102 , e.g., microprocessor, microcontroller, digital signal processor (DSP), programmable logic array (PLA), application specific integrated circuit (ASIC), etc., may comprise a configurable input-output (I/O) node 104 , a low power mode register 134 and a plurality of logic circuits 132 , some of which may be coupled to the configurable I/O node 104 and/or the low power mode register 134 .
[0020] The configurable I/O node 104 may comprise a driver 108 , a receiver 110 , and an I/O keeper cell 106 . An I/O configuration and data states signal line 130 may be used for configuring the configurable I/O node 104 as an input and/or an output node by asserting a desired configuration through the I/O keeper cell 106 and configuration control signal lines 128 and 126 . The I/O configuration and data states signal line 130 may also be used to configure the driver 108 as open collector, active pull-up, active pull-down, or tri-state having active logic high and active logic low with a high impedance third state. Selection of the pull-up or pull-down resistance value, slew rate, drive capabilities, etc., for the driver 108 may also be configured. These configurations may be performed by firmware in the integrated circuit device 102 and/or external program software having access to and configuration permission for the integrated circuit device 102 .
[0021] When the configurable I/O node 104 is configured as an output node, a data-out signal line 118 may be used to convey data from the plurality of logic circuits 132 of the integrated circuit device 102 , through the I/O keeper cell 106 , over the data signal line 122 to the driver 108 . The output of the driver 108 is coupled to the external I/O connection 112 of the integrated circuit package (not shown) containing the integrated circuit device 102 .
[0022] When the configurable I/O node 104 is configured as an input node, a data-in signal line 120 may be used to convey data to the plurality of circuits 132 of the integrated circuit device 102 , from the I/O keeper cell 106 , over the data signal line 124 from the receiver 110 . The input of the receiver 110 is coupled to the external I/O connection 112 of the integrated circuit package (not shown) containing the integrated circuit device 102 .
[0023] When the configurable I/O node 104 is configured as an input-output node, the data-in signal line 120 and the data-out signal line 118 function as described hereinabove. The driver 108 may remain active at all times wherein the receiver 110 will monitor the output state of the driver 108 , and/or the driver 108 may be placed in an inactive state, e.g., unasserted open collector or tri-state in high impedance, whenever an external data signal is expected to be received on the external I/O connection 112 .
[0024] When the integrated circuit device 102 goes into a low power mode, a signal on the enter low power mode signal line 114 will tell the I/O keeper cell 106 to latch-in (store, retain, etc.) the I/O configuration of the configurable I/O node 104 and the present data-in and/or data-out logic level on the data-in signal line 120 or data-out signal line 118 , respectively. This latched-in (stored, retained, etc.) I/O configuration and data logic level(s) may be retained during and after the integrated circuit device 102 goes into and comes out of the low power mode. The configurable I/O node 104 and low power mode register 134 remain operational with sustained power from a maintained power supply, V DD /V SS .
[0025] As the integrated circuit device 102 comes out of the low power mode, the plurality of logic circuits 132 will perform a systematic, well-defined sequence for waking up and for establishing proper logic levels on all internal signal paths of the integrated circuit device 102 . Only after all internal logic levels have been properly re-established may a wake-up and restore signal be sent on the wake-up and restore from low power mode signal line 116 , wherein the I/O keeper cell 106 will cease to latch-in (store, retain, etc.) the last I/O configuration and data logic level(s), and will become transparent again between circuits in the configurable I/O node 104 (e.g., driver 108 and/or receiver 110 ), and the data-out signal line 118 and/or data-in signal line 120 and the I/O configuration and data states signal line 130 . A bit from the low power mode register 134 may be used as the wake-up and restore signal sent over the wake-up and restore from low power mode signal line 116 .
[0026] It is contemplated and within the scope of this disclosure that the wake-up and restore from low power mode signal line 116 may be activated by software and/or firmware after the I/O configuration and data logic level(s), retained by the I/O keeper cell 106 , have been read by the software and/or firmware. Thus, software control of the wake-up and restore from low power mode signal line 116 may insure that the same I/O configuration and logic level(s) are retained, thereby not disturbing any external devices in the electronic system (not shown). The enter low power mode signal line 114 may also be activated by software and/or firmware before the integrated circuit device 102 goes into a low power mode.
[0027] It is also contemplated and within the scope of this disclosure that signal lines 114 and 116 may be combined into one signal line with a first logic level thereon indicating “enter low power mode” and a transition to a second logic level thereon indicating “wake-up and restore from low power mode.” Since the low power mode register 134 may be powered along with the configurable I/O node 104 from V DD /V SS , the single signal line “enter low power mode/wake-up and restore from low power mode” may be maintained in either the first logic level or second logic level when going into the low power mode or coming out of the low power mode, respectively, e.g., the transition from first logic level to second logic level, or visa-versa, would cause the change in operation of the configurable I/O node 104 from “enter low power mode” to “wake-up and restore from low power mode.”
[0028] Referring to FIG. 2 , depicted is a schematic block diagram of an output node having an output keeper cell in an integrated circuit device, according to another specific example embodiment of this disclosure. An integrated circuit device 102 , e.g., microprocessor, microcontroller, digital signal processor (DSP), programmable logic array (PLA), application specific integrated circuit (ASIC), etc., may comprise an output node 204 , a low power mode register 134 and a plurality of logic circuits 132 , some of which may be coupled to the output node 204 and/or the low power mode register 134 .
[0029] The output node 204 may comprise a driver 208 and an output keeper cell 206 . An output configuration and data states signal line 230 may be used for configuring the output node 204 by asserting a desired configuration through the output keeper cell 206 and configuration control signal line 226 . The output configuration and data states signal line 230 may also be used to configure the driver 208 as open collector, active pull-up, active pull-down, or tri-state having active logic high and active logic low with a high impedance third state. Selection of the pull-up or pull-down resistance value, slew rate, drive capabilities, etc., for the driver 208 may also be configured. These configurations may be performed by firmware in the integrated circuit device 102 and/or external program software having access to and configuration permission for the integrated circuit device 102 .
[0030] A data-out signal line 118 may be used to convey data from the internal logic circuits 132 of the integrated circuit device 102 , through the output keeper cell 206 , over the signal line 222 and to the driver 208 . The output of the driver 208 is coupled to the external output connection 212 of the integrated circuit package (not shown) containing the integrated circuit device 102 .
[0031] When the integrated circuit device 102 goes into a low power mode, a signal on the enter low power mode signal line 114 will tell the output keeper cell 206 to latch-in (store, retain, etc.) the present data-out logic level on the data-out signal line 118 . This latched-in (stored, retained, etc.) data logic level may be retained during and after the integrated circuit device 102 goes into and comes out of the low power mode. The output node 204 and low power mode register 134 remain operational with sustained power from a maintained power supply, V DD /V SS .
[0032] As the integrated circuit device 102 comes out of the low power mode, the plurality of logic circuits 132 will perform a systematic, well-defined sequence for waking up and for establishing proper logic levels on all internal signal paths of the integrated circuit device 102 . Only after all internal logic levels have been properly re-established will a wake-up and restore signal be sent on the wake-up and restore from low power mode signal line 116 , wherein the output keeper cell 206 will cease to latch-in (store, retain, etc.) the last output configuration and/or data logic level, and will become transparent again between circuits in the output node 204 (e.g., driver 208 ), and the data-out signal line 118 and the output configuration and data states signal line 230 . A bit from the low power mode register 134 may be used as the wake-up and restore signal sent over the wake-up and restore from low power mode signal line 116 .
[0033] It is contemplated and within the scope of this disclosure that the wake-up and restore from low power mode signal line 116 may be activated by software and/or firmware after the output configuration and data logic level, retained by the output keeper cell 206 , have been read by the software and/or firmware. Thus, software control of the wake-up and restore from low power mode signal line 116 may insure that the same output configuration and output logic level are retained, thereby not disturbing any external devices in the electronic system (not shown). The enter low power mode signal line 114 may also be activated by software and/or firmware before the integrated circuit device 102 goes into a low power mode.
[0034] It is also contemplated and within the scope of this disclosure that signal lines 114 and 116 may be combined into one signal line with a first logic level thereon indicating “enter low power mode” and a transition to a second logic level thereon indicating “wake-up and restore from low power mode.” Since the low power mode register 134 may be powered along with the output node 204 from V DD /V SS , the single signal line “enter low power mode/wake-up and restore from low power mode” may be maintained in either the first logic level or second logic level when going into the low power mode or coming out of the low power mode, respectively, e.g., the transition from first logic level to second logic level, or visa-versa, would cause the change in operation of the output node 204 from “enter low power mode” to “wake-up and restore from low power mode.”
[0035] Referring to FIG. 3 , depicted is a schematic block diagram of an input node having an input keeper cell in an integrated circuit device, according to yet another specific example embodiment of this disclosure. An integrated circuit device 102 , e.g., microprocessor, microcontroller, digital signal processor (DSP), programmable logic array (PLA), application specific integrated circuit (ASIC), etc., may comprise an input node 304 , a low power mode register 134 and a plurality of logic circuits 132 , some of which may be coupled to the input node 304 and/or the low power mode register 134 .
[0036] The input node 304 may comprise a receiver 310 and an input keeper cell 306 . An input configuration and data states signal line 330 may be used for configuring the input node 304 by asserting a desired configuration through the input keeper cell 306 and configuration control signal line 328 . The input configuration and data states signal line 330 may also be used to configure the receiver 310 for input impedance, speed, slew rate, power consumption, etc. These configurations may be performed by firmware in the integrated circuit device 102 and/or external program software having access to and configuration permission for the integrated circuit device 102 .
[0037] A data-in signal line 120 may be used to convey data to the plurality of logic circuits 132 of the integrated circuit device 102 , from the input keeper cell 306 , over the signal line 324 from the receiver 310 . The input of the receiver 310 is coupled to the external input connection 312 of the integrated circuit package (not shown) containing the integrated circuit device 102 .
[0038] When the integrated circuit device 102 goes into a low power mode, a signal on the enter low power state signal line 114 will tell the input keeper cell 306 to latch-in (store, retain, etc.) the present data-in logic level on the data-in signal line 120 . This latched-in (stored, retained, etc.) data logic level may be retained during and after the integrated circuit device 102 goes into and comes out of the low power mode. The input node 304 and low power mode register 134 remain operational with sustained power from a maintained power supply, V DD /V SS .
[0039] As the integrated circuit device 102 comes out of the low power mode, the plurality of logic circuits 132 will perform a systematic, well-defined sequence for waking up and for establishing proper logic levels on all internal signal paths of the integrated circuit device 102 . Only after all internal logic levels have been properly re-established may a wake-up and restore signal be sent on the wake-up and restore from low power mode signal line 116 , wherein the input keeper cell 306 will cease to latch-in (stored, retained, etc.) the last input configuration and/or data logic level, and will become transparent again between circuits in the input node 304 (e.g., receiver 310 ), and the data-in signal line 120 and the input configuration and data states signal line 330 . A bit from the low power mode register 134 may be used as the wake-up and restore signal sent over the wake-up and restore from low power mode signal line 116 .
[0040] It is contemplated and within the scope of this disclosure that the wake-up and restore from low power mode signal line 116 may be activated by software and/or firmware after the input configuration and data logic level, retained by the input keeper cell 306 , have been read by the software and/or firmware. Thus, software control of the wake-up and restore from the low power mode signal line 116 may insure that the same input configuration and input logic level are retained, thereby not disturbing any external devices in the electronic system (not shown). The enter low power mode signal line 114 may also be activated by software and/or firmware before the integrated circuit device 102 goes into a low power mode.
[0041] It is also contemplated and within the scope of this disclosure that signal lines 114 and 116 may be combined into one signal line with a first logic level thereon indicating “enter low power mode” and a transition to a second logic level thereon indicating “wake-up and restore from low power mode.” Since the low power mode register 134 may be powered along with the input node 304 from V DD /V SS , the single signal line “enter low power mode/wake-up and restore from low power mode” may be maintained in either the first logic level or second logic level when going into the low power mode or coming out of the low power mode, respectively, e.g., the transition from first logic level to second logic level, or visa-versa, would cause the change in operation of the input node 304 from “enter low power mode” to “wake-up and restore from low power mode”.
[0042] Referring to FIG. 4 , depicted is a schematic operational flow diagram of an integrated circuit device entering into and returning from a low power mode, retention of data states and I/O configurations of an input-output (I/O) node of the integrated circuit device, according to a specific example embodiment of this disclosure. In step 402 , an integrated circuit device enters into a low power mode. In step 404 , the input and/or output data state(s) and I/O configuration are retained in a keeper cell. In step 406 , the I/O configuration and data state(s) are controlled by the retained information in the keeper cell irrespective of the logic states from the plurality of logic circuits of the integrated circuit device. In step 408 , the plurality of logic circuits of the integrated circuit device wake-up from the low power mode and their logic circuit states are woken-up and restored after coming out of the low power mode. Once the logic circuit states of the plurality of logic circuits have been properly restored to a fully operational condition, an exit from low power mode will be asserted in step 410 , and then in step 412 control of the I/O configuration and data state(s) will be returned back to the now fully operational plurality of logic circuits.
[0043] Referring to FIG. 5 , depicted is a schematic operational flow diagram of an integrated circuit device entering into and returning from a low power mode under software control and retention of data states and I/O configurations of an input-output (I/O) node of the integrated circuit device, according to another specific example embodiment of this disclosure. Step 500 determines when an enter low power mode command is made from a software and/or firmware program. When the enter low power mode command is determined in step 500 , an integrated circuit device will enter into a low power mode in step 502 . In step 504 , the input and/or output data state(s) and I/O configuration are retained in a keeper cell. In step 506 , the I/O configuration and data state(s) are controlled by the retained information in the keeper cell irrespective of the logic states from the plurality of logic circuits of the integrated circuit device. In step 508 , the plurality of logic circuits of the integrated circuit device wake-up from the low power mode and their logic circuit states are woken-up and restored after coming out of the low power mode. Step 509 determines when a wake-up and restore from low power mode command is made from a software and/or firmware program. When the wake-up and restore from low power mode command is determined in step 509 , the integrated circuit device will exit from the low power mode in step 510 . Then in step 512 , control of the I/O configuration and data state(s) will be returned back to the now fully operational plurality of logic circuits.
[0044] While embodiments of this disclosure have been depicted, described, and are defined by reference to example embodiments of the disclosure, such references do not imply a limitation on the disclosure, and no such limitation is to be inferred. The subject matter disclosed is capable of considerable modification, alteration, and equivalents in form and function, as will occur to those ordinarily skilled in the pertinent art and having the benefit of this disclosure. The depicted and described embodiments of this disclosure are examples only, and are not exhaustive of the scope of the disclosure. | A semiconductor integrated circuit device upon exiting from a low power mode, wakes up and re-initializes logic circuits so as to restore previous logic states of internal registers without disturbing input-output (I/O) configuration control and data states present at the time the low power mode was entered. Thus not distributing the operation of other devices connected to the semiconductor integrated circuit device previously in the low power mode. Once all internal logic and registers of the semiconductor integrated circuit device have been re-initialized, a “low power state wake-up and restore” signal may issue. This signal indicates that the I/O configuration control and data states stored in the I/O keeper cell at the time the integrated circuit device entered into the low power mode have been reinstated and control may be returned to the logic circuits and/or internal registers of the semiconductor integrated circuit device. | 6 |
FIELD OF THE INVENTION
This invention relates to a process for preparing curcumin encapsulated chitosan alginate sponge useful for wound healing.
BACKGROUND OF THE INVENTION
Wound healing is a complex physiological response to the injury. It is a very systemic biological, chemical, and mechanical event where the invaded pathogens removed from the damaged wound site for complete or partial remodeling of injured tissue. In general, it precedes in a very orderly and efficient manner characterized by three interrelated dynamic and overlapping phases, namely, inflammatory phase (consisting the establishment of homeostasis and inflammation; proliferative phase (consisting of granulation, contraction and epithelialisation) and finally the remodeling phase [1-3]. However, in severe pathologic conditions this cascade healing process is lost and the wounds are locked into a state of chronic inflammation characterized by abundant neutrophil infiltration with associated release of inflammatory mediators including reactive oxygen species, reactive nitrogen species and their derivatives. These radicals will result in oxidative stress leading to lipid peroxidation, DNA breakage, and enzyme inactivations ultimately cause local and distant pathophysiological inflammatory effects [1,4]. Mitigation of this dysregulated chronic inflammation (the major cause of impaired wound healing) and finding a safe and efficacious anti-inflammatory agent is a frontier challenge in modern medicine. However, the role of oxidants in the pathogenesis of many inflammatory diseases suggests that antioxidant has effective strategy for therapeutic approaches to such disorders [5]. To this end, anti oxidant activities of the traditional medicine give a new horizon for better healing treatment. Topical applications of compound with free radical scavenging properties have shown significant improvement in wound healing and protect tissue from oxidative damage [6]. In this regard, topical application of the upcoming anti-inflammatory drug modality of natural herbal extracts curcumin and its antioxidants properties will be certainly benefit against oxidative damage and be helpful to the better healing of the wound.
Curcumin (diferuloylmethane), a naturally occurring photochemical derived from the rhizome of turmeric (Curcuma longa). It has low intrinsic toxicity but a wide range of pharmacological activity including anti-oxidant, anti-inflammatory and anti-infective properties [7-10]. The antioxidant activity of curcumin could be attributed to the phenolic and the methoxy groups in conjunction with the 1,3-diketone conjugated diene system, for scavenging of the oxygen radicals. In this view, several in vitro and in vivo studies have demonstrated the effectiveness of curcumin to decrease the release of inflammatory cytokines like interleukin (IL)-8 and tumour necrosis factor (TNF-α) from monocytes and macrophages and further to inhibit enzymes associates with inflammation, such as cyclo-oxygenase (COX)-2 and lipoxygenase (LOX) [11,12]. By reducing the effects of these enzymes, curcumin has shown to prevent the inflammation symptoms of many diseases like arthritis and alzheimer's disease [13]. Furthermore, various studies using rat models showed the accelerated wound healing activity of curcumin owing to its powerful anti-oxidant property. Also the ability of curcumin to assist wound healing in diabetic mice has been well demonstrated by various groups. Where curcumin treatment in diabetic wound demonstrated an increased formation of granulation tissue, neovascularization and enhanced biosynthesis of extracellular matrix (ECM) proteins, such as collagen [14]. Similarly, Panchatcharam et al in rat model demonstrated on treatment of curcumin, lipid peroxides (LPs) was decreased, while the levels of superoxide dismutase (SOD), catalase (CAT), glutathione peroxidase (GPx), activities were significantly increased exhibiting the antioxidant properties of curcumin in accelerating wound healing [4]. These observations demonstrated, curcumin has a property to scavenge free radicals, which is the major cause of inflammation during wound healing activity. Despite these unique biological activities, a major problem associated with curcumin delivery is its extreme low solubility in aqueous solubility in aqueous solutions, which limits its bioavailability and clinical efficacy [8,11,12]. One possible method to achieve this paradigm is encapsulating and delivering curcumin to inflammatory site with wound dressing sponge. This sponge are fabricated with various biocompatible and biodegradable materials, such as alginate, chitosan, gelatin and poly (ethylene glycol) and recently gained the attention in pharmaceutical and biomedical arena, as matrices for wound dressings [15,16]. Many types of polymers have been used for drug delivery system but the requirements of the biocompatibility and biodegradability have limited the choice of polymers used in clinical application. Some representatives of such materials are chitosan and alginate. Chitosan is a natural cationic mucoadhesive polymer, is biologically renewable, biodegradable, biocompatible, nonantigenic, nontoxic, and biofunctional. It can accelerate the wound healing process by enhancing the functions of inflammatory cells like macrophages and fibroblasts. It could inhibit nitric oxide production that has been shown to contribute to cytotoxicity in cell proliferation during inflammation of wound healing by the activated RAW 264.7 macrophages and allow the formation of granulation tissue with angiogenesis [17]. Furthermore, it is a penetration enhancer which can provide maximum bioavailability of delivered drug, at wound site [18]. Whereas, Alginate is an anionic polymer with additional characteristics like biocompatible, hydrophilic, and biodegradable under normal physiological conditions [18]. It is able to maintain a physiologically moist microenvironment that promotes healing and the formation of granulation tissue and achieves homeostasis [15,16]. In recent year the alginate-chitosan (AC) sponge with entrapped therapeutics are of special interest for wound healing purposes owing to their biocompatibility, biodegradaibility and ability to sustain therapeutic drug levels for prolonged periods of time. Moreover, its polymeric matrix can prevents the degradation of the drug, by protecting the encapsulated curcumin against hydrolysis and biotransformation for a longer time. Beside low aqueous solubility, the major concerned associated with curcumin delivery is its severe biodegradation and instability in biological pH. In this regard, coating the drug with large molecules, such as surfactants containing long-chain hydrocarbons, helps to provide more effective stabilization of entrapped drug in biological medium. Therefore research groups are using long chain surfactant such as oleic acid (OA) and its salt for the stabilization of various drug delivery systems.
In this scenario, the current approach was to prepare and characterize curcumin loaded sponge composed of oleic acid, chitosan and sodium alginate. We hypothesized that the hydrophobic drug curcumin would partition in to the coated oleic acid shell. Whereas, alginate and chitosan anchors at the interface of the OA shell and give the aqueous dispersibility and easy load of hydrophobic anticancer drug curcumin. Here the positively charged chitosan can be easily complexed with negatively charged polyanions sodium alginate to form porous AC sponge through the interionic interaction. The large surface area of the sponge facilitates the interaction with the healing tissue, thereby serving as a substrate for the sustained delivery of curcumin as well as improves wound healing by protecting tissues from oxidative damage. Thus, the aim of the present study is to evaluate the biological activity of the formulated curcumin-loaded AC sponge using in vitro and in vivo methods.
OBJECTS OF THE INVENTION
An object of this invention is to propose a process for preparing curcumin encapsulated chitosan alginate sponge;
Another object of this invention is to propose a curcumin encapsulated chitosan alginate sponge used for the better healing of the wound;
Further object of this invention is to propose an anti-inflammatory drug for topical application;
Still further object of this invention is to propose a natural herbal wound dressing sponge;
Another object of this invention is to propose a potential topical curcumin delivery system showing sustained release of entrapped curcumin for a longer period of its administration.
BRIEF DESCRIPTION OF THE INVENTION
According to this invention there is provided a process for preparing curcumin encapsulated chitosan alginate sponge comprising the steps of:
incorporating curcumin in a fluid phase of oleic acid;
subjecting the mixture to a step of emulsification with chitosan solution for few minutes homogenizing the resultant solution with alginate solution;
Lyophilizing the final emulsion by freeze drying to produce curcumin loaded AC sponge.
BRIEF DESCRIPTION OF THE ACCOMPANYING DRAWINGS
FIGS. 1 a : shows photograph of different formulations (1:1, 1:2 and 1:3) of alginate-chitosan sponge.
FIGS. 1 b : shows Scanning electron micrograph image for sponge containing a) 1:1 alginate-chitosan b) 1:2 alginate-chitosan c) 1:3 alginate-chitosan
FIG. 2 : FTIR spectra of (a) Alginate (b) Chitosan (c) curcumin (d) void sponge (e) 1:1 alginate-chitosan sponge (f) 1:2 alginate-chitosan sponge (g) 1:3 alginate-chitosan sponge
FIG. 3 a : shows in vitro water uptake ability of different formulation of alginate-chitosan sponges.
FIG. 3 b : shows in vitro degradation of alginate-chitosan sponge in PBS lysozyme solution.
FIG. 3 c : shows the in vitro release kinetics of curcumin from different formulation of alginate-chitosan sponge.
FIG. 4 : shows photographical representation of contraction rate of wound covered with (a) cotton gauze as control, (b) void 1:2 alginate-chitosan sponge and (c) curcumin loaded 1:2 alginate-chitosan sponge at different post wounding day of our observation.
FIG. 5 : shows total wound area of skin at different post wounding day as a percentage of original wound size.
DETAILED DESCRIPTION OF THE INVENTION
Preparation of Curcumin Encapsulated Chitosan-Alginate Sponge:
Briefly, Alginate solution (0.5% w/v) was prepared by dissolving sodium alginate powder (0.1 g) in 20 ml of deionised water at room temperature. Chitosan solution (0.5% w/v) was prepared by dissolving chitosan powder (0.1 g) in 20 ml of deionized water containing acetic acid (1.0% by weight) at room temperature. To form curcumin encapsulated AC Sponge, 50 mg of curcumin was incorporated in to fluid phase of 1.75 ml oleic acid. The oleic acid mixture was then emulsified with chitosan solution for 2 minute. The resultant solution was further homogenized (Biospacte Product Inc, Bartlesville, Okla.) for 3 minute with alginate solution. In this way, curcumin loaded AC sponge solution with different alginate: chitosan blend ratio (1:1, 1:2 and 1:3) were prepared (keeping curcumin and OA content constant) and pour out in a 6-well plate (well area: 9.6 cm 2 ). The suspension decant in 6 well plate was lyophilized for three days (−80° C. and <10 μm mercury pressure, LYPHLOCK, Labconco, Kansas City, Mo.) to get lyophilized sponge for further use.
Physicochemical Characterization of Chitosan-Alginate Sponges
Scanning Electron Microscope (SEM) Studies
The surface morphology of different formulation of curcumin encapsulated AC Sponge were characterized by SEM (JEOL JSMT220A scanning electron microscopy, MA) operating at an accelerating voltage of 10-30 Kv. The sponges were sputtered with gold to make them conductive and placed on a copper stub prior to the acquisition of SEM images.
Fourier Transform Infrared (FTIR) Spectral Study
FTIR spectra were taken in to observation (Perkin Elmer, Model Spectrum RX 1, USA) to investigate the possible chemical interactions between the curcumin and the AC sponge matrix. Native curcumin, alginate, chitosan, void sponge, different formulation of curcumin loaded sponge were crushed with KBr to get the pellets by applying a pressure of 300 kg/cm 2 . FTIR spectra of the above sample were obtained by averaging thirty two interferograms with resolution of 2 cm −1 in the range of 1000 to 4000 cm −1 .
Swelling Ability Study of Sponges
The swelling ability of different formulations of AC sponge was determined by equilibrium swelling study. The different formulation of sponges 1 cm×1 cm size were immersed in to PBS (0.01 M, PH 7.4). The weight of sponges was recorded every minute until equilibrium was reached. At each emersion interval, the samples were removed and the absorbed water gently removed with filter paper. The samples were then weighed immediately on a micro balance. Each experiment was repeated three times, and the average value was taken as the percentage water adsorption. The initial sample weight before immersion was recorded as W 0 and the sample weight after each immersion interval was recorded as W e . The percent swelling at equilibrium E sw was calculated from the Flory-Huggins swelling formula:
E SW (%)= W e −W 0 /W 0 ×100
In Vitro Degradation Study
The different formulation of AC sponges were incubated at phosphate-buffered saline (0.01 M, pH 7.4) with 500-1000 U/C.C. of lysozyme concentration in 6-well plate and kept at 37° C. [16]. At required period of time, the sponges were taken out, washed with deionized water, frozen, and lyophilized. The weights of the sponges were weighed in a microbalance and percentage of weight loss was calculated using the following equation:
Weight loss (%)=( W 0 −W t )/ W 0 ×100.
In Vitro Release Kinetics of Curcumin from Different Formulation of AC Sponge by (HPLC) Method
In vitro release kinetics of curcumin from different formulations of curcumin loaded sponges were determined in PBS (0.01M, pH 7.4) with little modification. A total of 10 mg of curcumin-loaded chitosan-alginate sponge was suspended in 3 ml of PBS (0.01M, pH 7.4). It was mixed properly by vortexing and kept in a shaker at 37° C., rotating at 150 rpm in an orbit shaking incubator (Wadegati Lab equip, India). At predetermined time intervals, the samples were collected and replaced with same volume of fresh PBS (0.01 M, Ph 7.4). The collected samples were then subjected to centrifugation at 13, 800 rpm, 4° C. for 10 min (SIGMA 3K30, Germany) to obtain the supernatant containing released curcumin. The released curcumins profile was analysed using reverse phase isocratic mode (RP-HPLC) system of Waters™ 600, Waters Co. (Milford, Mass., USA) as described earlier [12]. For this, 20 μl of the sample was injected manually in the injection port and analyzed in the mobile phase consisting of a mixture of 60% acetonitrile and 40% citric buffer [1% (w/v) citric acid solution adjusted to pH 3.0 using 50% (w/v) sodium hydroxide solution] which was delivered at flow rate of 1 ml/min with a quaternary pump (M600E WATERS™) at 25° C. with a C 18 column (Nova-Pak, 150×4.6 mm, internal diameter). The curcumin levels were quantified by visible detector at 420 nm with dual wave length absorbance detector (M 2489). All measurements were performed in triplicates and the cumulative percentage of curcumin release was calculated and plotted versus time.
In Vivo Wound Healing Test
The Sprague-Dawley (SD) rats (160-180 g, 6 weeks) were used for wound healing test. The animals were anaesthetized intramuscularly by ketamine (100 mg/kg) and xylazine (10 mg/kg). The dorsal hair of the rats was removed. Full-thickness wound of 1.5×1.5 cm 2 was excised from the back of the rats. Each wound was covered with an equal size of curcumin loaded sponge, or void sponge, or cotton gauge for comparison. All wounds are covered with a piece of non adherent occlusive bandage. Treated rats were placed in individual cages, and the healing wounds were observed on the 0 th , 4 th , 8 th and 10 th days using a digital camera (Sony, cyber-shot, DSC-H9). The area of wound was calculated by measuring the length and breadth of the wound with digital slide calipers.
Results
Physicochemical characterization of chitosan-alginate sponges AC sponges were successfully prepared as a result of interaction in between positively charged chitosan and negatively charged sodium alginate. We have prepared three different formulations of sponge by varying alginate to chitosan in different ratio (1:1, 1:2 and 1:3) as shown in FIG. 1 a . The resultant sponges were soft, light and fibrous in textures with adequate flexibility which will inevitably be required for in vivo applications.
Morphology Study
Scanning electron microscopy was employed to evaluate the morphological characteristics of the sponges. The cross section morphology of sponges appears porous and fibrillar structure in all the three formulations. However, it was observed that its morphology mainly depends on its alginate and chitosan content. To this end, we observed the sponge containing 1:1 ratio of alginate-chitosan was more irregular with highly interconnected cavities ( FIG. 1 b ) compared to other formulation. Further, with increase in ratio of chitosan to alginate we found a gradual enlargement of pore size as seen in sponge matrix ( FIG. 1 b ). This difference could be due to profound interanionic interaction between alginate and chitosan in sponge formulation containing equal proportionate of chitosan and alginate compared to other two formulations.
Fourier Transform Infrared (FTIR) Spectral Study
FTIR analysis was taken in to consideration to confirm the presence of curcumin in our AC sponge formulation as well as to examine any chemical (formation of chemical bonds) changes that might occurred in the polymer due to the addition of drug during the synthesis reaction. FIG. 2 shows the FTIR spectra's of alginate, chitosan, native curcumin void AC sponge and three different formulations of AC sponges. The characteristic band at 3434 cm −1 can be attributed to —NH2 and —OH groups stretching vibrations in the chitosan matrix and a band for amide I at 1651 cm −1 can be seen in the infrared spectrum of chitosan [18]. The alginate spectrum shows characteristic band of carbonyl (C═O) band at 1640 and 1424 cm −1 [16]. The FTIR spectrum of native curcumin exhibited an absorption band at 3510 cm −1 attributed to the phenolic O—H stretching vibration. Additionally, sharp absorption bands at 1605 cm −1 (stretching vibrations of benzene ring of curcumin), 1510 cm-1 (C═O and C═C vibrations of curcumin), 1627 cm −1 (C═C double bonds) and 1602 cm −1 due to aromatic C═C double bonds. These marker peaks were also found in different formulation of AC sponges and were not noticed in void sponge, suggesting curcumin exist inside the sponge matrix. Similar results were also observed by Yallapu et al. and Mohanty et al. [12, 19]. Further, no shifting of these signature peaks, attributing curcumin could be present in dispersed condition in different formulation of AC sponges.
Water Uptake Ability
The ability of the sponge to absorb water is one of the important factors in determining its biological activity. Here we used PBS to evaluate the uptake ability (at 37° C.) as it mimics the body fluid and conditions. The percent swelling in three formulation of sponge are given in FIG. 3 a . It was observed that all sample achieved equilibrium after immersion for 1 minute in to PBS solution. Similarly, all sponges exhibited good swelling as they had the ability to retain more water due to its high porous infrastructure. The result further demonstrated the sponge developed from alginate to chitosan ratio 1:1 (w/w proportion) showed minimum percent of swelling compared to other formulation. The 1:3 AC sponges showed a highest of about 35% and 1:2 sponges showed a medium of 31% water uptake ability. In contrast, the 1:1 AC sponge gave a minimum value of about 17% water uptake due to its micro porous configuration compared to other formulation.
In Vitro Degradation
Sponges used for wound healing should be biocompatible and biodegradable. Its degradation behavior is a crucial parameter needs to explain before imposing for long term dressing. So the percentage of weight loss of different formulation of sponges as a function of degradation time was taken in to observation and the results are presented in FIG. 3 b . The in vitro degradation result degradation result demonstrated the weight loss for different formulation of AC sponges ranges from 22% to 65%. Further, it was observed that 1:1 AC sponge showed 1.3 and 2.8 times higher weight loss compared to 1:2 and 1:1 AC sponges respectively. This result indicated that 1:1 AC sponge was more stable compared to 1:2 and 1:3 sponges, probably because cross linking degree of 1:1 sponge was stronger than the others.
In Vitro Release Kinetics
Therapeutic efficiency of drug loaded sponges solely depends on the dose and released of the entrapped drug from its matrix at wound site. In this view, while observing the in vitro release profile, we observed a biphasic release pattern of entrapped curcumin from all sponge formulations used in our study ( FIG. 3 c ). In 1:3 AC sponge, the burst release of curcumin (37.88±1.8%) was observed in first day which was followed by a slow and continuous release. Similarly, in 1:2 and 1:1 AC formulation, the release profile of curcumin was observed as 27.99±2.9 and 29.7±1.9% respectively in the first day followed by a slow and sustained release for a prolong time period of 10 days of our observation. The observed initial burst release might be due to the dissociation of surface absorbed drugs present in the polymeric matrix. Subsequently, sustained release activity of the drugs was due to the slow release of drugs entrapped inside the polymer matrix.
Wound Healing Test
After observing the in vitro release profile of curcumin from different formulation of AC sponges, we found 1:2 and 1:1 AC sponge formulation showed almost similar sustained release profile. However, 1:2 AC sponge formulations was chosen as suitable formulation for our wound healing experiment, because of its larger pore size and more water uptake ability compared to 1:1 formulation. This loose fabric structure or porosity could give proper ventilation to ensure no oxygen deficiency over the wound [20]. An ideal dressing sponge must achieve certain characteristics like good biodegradability, biocompatibility, slow sustained release of entrapped drug for longer time and moreover not to be associated with incidental adverse effects during healing process. In order to justify our formulated sponge's persuasive healing efficacy, in vivo healing studies were conducted with 1:2 AC sponge with or without curcumin. For control, the wound was covered with cotton gauze. The wound healing observation showed that on the 4 th postoperative day the cotton gauze adhered to wound surface and removal of it resulted in the loss of tissue and oozing of blood at the wound surface indicating tissues are under inflammation phase. However, AC sponge found to adhere at the wound surface and absorbed the bleed and exudation at the wound site. It suggests that the sponge containing alginate fiber absorbs the wound exudates to form a hydrogel protection layer that holds the moisture around the wound, on other hand chitosan enhances the infiltration of inflammatory cell and consequently accelerating wound cleaning. In this view, our observation also showed more healing of wound dressed with AC sponge compared to control. During dressing while removing the sponge from wound area, we have observed little bleeding and inflammation in void treated wound. In contrast, no sign of inflammation and oozing of blood with thicken underlying granulation tissue was marked in case of curcumin sponge treated wound, suggesting wound tissues are quickly preceded from inflammatory stage to proliferating stage. So, another prospective characteristic of using the AC sponge was its hydrogel layer which can reduces the frequency of dressing change (as it is biodegradable, biocompatible and absorbable) by holding the moisture around the wound. Further, the reduction in wound defect area was calculated by observing the wound area at various time intervals of our wound healing study.
From FIG. 4 , the significant difference of wound closure was clearly marked in between the control and AC sponge treated groups on 4 th postoperative day. Conversely, we have not marked any significant difference of wound closure in void and curcumin treated sponge on the same day of our observation, suggesting irrespective of curcumin content our formulated AC sponge is a good absorbent and suitable substrate for better wound healing. The photograph further demonstrated curcumin sponge treated wound showed no sign of inflammation compared to control and void sponge treated wound, suggesting its early recovery from inflammation phase. This observation could be due to constant and profound release of anti inflammatory and anti infective drug curcumin from curcumin loaded AC sponge at wounded site. Similarly, on 8 th day post wounding, it was observed that with time curcumin sponge-treated wounds showed more healing response compared to void sponge and cotton gauze-treated wounds. While measuring the wound size we found the wound area of curcumin loaded AC sponge is almost half and one third of the void and cotton gauze treated wound area respectively ( FIG. 5 ). On the 10 th postoperative day we observed the control, void sponge and curcumin sponge treated wounds contracted 68%, 80% and 94% respectively. It suggests though AC sponge is a good substrate showing better healing but curcumins anti oxidant and anti inflammatory properties accelerate the healing ability more profoundly with time. Thus, the results demonstrated curcumin loaded AC sponge may be useful as a therapeutic approach for better wound healing in near future.
The present study reveals that the mechanical release, water uptake, degradation and morphological properties of AC sponge are highly dependent on composition. The successful encapsulation of curcumin within AC sponge brought about a new avenue to improve the bioavailability of curcumin and can make the drug amenable for topical application in wound healing. Most importantly, the observed comprehensible results justified the curcumin loaded AC sponge was comparatively more effective than void AC sponge for wound healing therapeutic approach with time due to sustained drug retention and enhanced anti inflammatory effect. | A process for preparing curcumin encapsulated chitosan alginate sponge comprising the steps of: incorporating curcumin in a fluid phase of oleic acid; subjecting the mixture to a step of emulsification with chitosan solution by homogenization; emulsifying the resultant solution with alginate solution by homogenization; lyophilizing the final emulsion by freeze drying to produce curcumin loaded AC sponge. | 0 |
BACKGROUND OF THE INVENTION
1. Field of the Invention
The present invention relates to a lubricant and a magnetic recording medium using the same. More specifically, the lubricant allows for low friction, low abrasion sliding between two touching solids, regardless of high or low speeds, or high or low loads, and under all environmental conditions such as high or low temperatures, or high or low humidity. The present invention also pertains to the use of this lubricant in magnetic recording media having excellent durability and traveling performance.
2. Prior Art
With the aim of allowing for low friction, low abrasion sliding between two touching solids and lengthening the usage period of instruments and equipment, development is being carried out on the hardening of solid surfaces and on lubricants. The demand for size reduction in the OA instrument field is particularly strong, and every year precise mechanisms in the slidable portion area are introduced. In the future, precision parts will require increasing reductions in friction and abrasion when the sliding begins, ends and is in progress, and a greater reduction in the load on the motor, etc., than is provided by the current slidable instruments, when they operate continuously or discontinuously under a broad range of environmental conditions. In conventional protective lubrication systems, the slidable position has a hard surface layer which is difficult to abrade, and grease, oil, half-solid or liquid lubricants are used.
However, in precision equipment in which smoothing of the touching portions have been completed, a lubricant which allows low friction, low abrasion sliding between two touching solids regardless of high or low speeds, and high or low loads cannot be obtained. Thus, the problems of poor starting, or a sudden accidental increase in the friction force when sliding cannot be avoided.
When compared to coating type magnetic recording media, ferromagnetic metal thin film type magnetic recording media, which are made by depositing ferromagnetic metals or their alloys, etc. on a non-magnetic support by vacuum deposition, etc., can easily increase the anti-magnetization properties and decrease the thickness of the media, and have good high-density recording properties. On the other hand, they have disadvantages in that the coefficient of friction at the magnetic head increases, and they are easily abraded or damaged, since they use no tough binder resin, and the ferromagnetic metal thin film layer or the protective membrane has good surface smoothness. Thus, their durability and traveling performance are inferior.
Accordingly, durability and traveling performance are improved by the provision of various lubricants, such as ester-type lubricants, on the ferromagnetic metal thin film (see U.S. Pat. Nos. 4,735,848, 5,356,726 and 5,376,465, and Japanese Kokai Patent Publication Nos. 60-85427, 2-210615, 4-368621 and 6-274858).
However, the problem of smudging on the magnetic head or "drop out" has not been solved. The durability and traveling performance are insufficient, especially under high temperature and humidity conditions.
SUMMARY OF THE INVENTION
One object of the present invention is to provide a lubricant that can allow the low friction, low abrasion sliding between two touching solids regardless of high or low speeds, or high or low loads, even in the smoothing of the portion at the touching position, thereby ensuring future precision.
Another object of the present invention is to provide a magnetic recording medium which has excellent durability and traveling performance.
According to the first aspect, the present invention provides a lubricant comprising a branched aliphatic diester of the general formula:
R.sub.1 R.sub.2 R.sub.3 C--(CH.sub.2).sub.n --X--R--X'--(CH.sub.2).sub.n --CR.sub.4 R.sub.5 R.sub.6
wherein R 1 to R 6 are the same or different and represent a hydrocarbon group having 1-18 carbon atoms;
R is a hydrocarbon group or a fluorinated hydrocarbon group having 6 to 18 carbon atoms;
either one of X and X' represent either one of --OCO-- and --COO--, while the other of X and X' represent the other of --OCO-- and --COO--; and
n is an integer from 0 to 6.
The fluorinated hydrocarbon groups include perfluorinated hydrocarbon groups and partially fluorinated hydrocarbon groups.
According to the second aspect, the present invention provides a lubricant comprising a branched aliphatic diester of the general formula:
R.sub.1 R.sub.2 R.sub.3 C--(CH.sub.2).sub.n --X--R--X'--(CH.sub.2).sub.n --CR.sub.4 R.sub.5 R.sub.6
wherein R 1 to R 6 , R, X, X' and n are the same as defined above,
and an aliphatic amine of the general formula:
R.sub.7 NR.sub.8 R.sub.9
wherein R 7 , R 8 and R 9 are the same or different and represent a hydrogen atom or a hydrocarbon group having 1 to 26 carbon atoms.
According to the third aspect, the present invention provides a magnetic recording medium comprising a non-magnetic support and a magnetic layer on at least one side of said non-magnetic support, wherein the magnetic medium contains a lubricant which comprises a branched aliphatic diester of the general formula:
R.sub.1 R.sub.2 R.sub.3 C--(CH.sub.2).sub.n --X--R--X'--(CH.sub.2).sub.n --CR.sub.4 R.sub.5 R.sub.6
wherein R 1 to R 6 , R, X, X' and n are the same as defined above
within or on the surface of the magnetic layer.
According to the fourth aspect, the present invention provides a magnetic recording medium comprising a non-magnetic support and a magnetic layer on at least one side of said non-magnetic support wherein the medium contains a lubricant which comprises a branched aliphatic diester of the general formula:
R.sub.1 R.sub.2 R.sub.3 C--(CH.sub.2).sub.n --X--R--X'--(CH.sub.2).sub.n --CR.sub.4 R.sub.5 R.sub.6
wherein R 1 to R 6 , R, X, X' and n are the same as defined above,
and an aliphatic amine of the general formula:
R.sub.7 NR.sub.8 R.sub.9
wherein R 7 , R 8 and R 9 are the same as defined above within or on the surface of the magnetic layer.
BRIEF DESCRIPTION OF THE DRAWING
FIG. 1 is an IR spectrum of the branched aliphatic diester prepared in Preparation Example 1.
DETAILED DESCRIPTION OF THE INVENTION
In the present invention, the branched aliphatic diester, which has two ester groups per molecule and is represented by the general formula:
R.sub.1 R.sub.2 R.sub.3 C--(CH.sub.2).sub.n --X--R--X'--(CH.sub.2).sub.n --CR.sub.4 R.sub.5 R.sub.6
wherein R 1 to R 6 , R, X, X' and n are the same as defined above,
has excellent lubrication properties and, when used as a lubricant, can allow two touching solid surfaces to slide with low friction and low abrasion.
The branched aliphatic diester has good resistance to hydrolysis, since it has the branched groups. Several experiments have been carried out with varying temperature, moisture and oxygen concentration in an atmosphere, for revealing the mechanism of decomposition of the ester-type lubricants, and it has been found that the presence of water accelerates the decomposition, and thus the cause for the decomposition is a hydrolysis reaction. A hydrolysis reaction occurs as OH - ions or H 30 + ions attack the carbonyl group of the ester. Because the branched aliphatic diester used in the present invention has a very bulky branched hydrocarbon group close to the carbonyl group, there is a large steric hindrance and, as a result, hydrolysis of the ester linkage is not easily initiated even under high temperature and humidity conditions, and the diester is chemically stable. When using it in magnetic recording media, the formation of lubricant-modification products causing dirt marks on the head or "drop out" can be reduced.
Moreover, the branched aliphatic diester can be stable and firmly adsorbed on the surface of the ferromagnetic metal thin film or protective membrane due to the presence of two ester groups per molecule. As a result, the lubricant can remain stable and can demonstrate favorable sliding characteristics without being removed from the sliding surface even under high load conditions such as at the commencement of sliding.
Therefore, the branched aliphatic diester can allow sliding between two touching solids with low friction and low abrasion regardless of high or low speeds, or high or low loads. It is strongly adsorbed and remains stable on the magnetic layer surface or on the surface of the protective membrane, or it is included in a stable state inside the magnetic layer, when used for magnetic recording media. Accordingly, the excellent lubricating function is sufficiently demonstrated along with a significant reduction in dirty marks on the magnetic head or "drop out", and the durability and traveling performance of the magnetic recording media can also be sufficiently improved.
The branched aliphatic diester can sufficiently control hydrolysis, even under high temperature and humidity conditions, due to steric hindrance, because it has a tertiary carbon atom in a position adjacent or close to the carbonyl group. There may be a hydrocarbon group between the tertiary carbon and the carbonyl group. However, if this hydrocarbon group has 7 or more carbon atoms, then the efficacy of the steric hindrance caused by the branched hydrocarbon group cannot be sufficiently obtained because the tertiary carbon and the carbonyl group are too far away from each other. Therefore, there are preferably 0-6 carbon atoms in the hydrocarbon group between the tertiary carbon and the carbonyl group, more desirably, three or fewer and, at best, none.
Each of the individual hydrocarbon groups R 1 , R 2 , R 3 , R 4 , R 5 , and R 6 , which are bonded to the tertiary carbons of the branched aliphatic diester, preferably have no fewer than 1 but no more than 18 carbon atoms. This is irrespective of whether they are saturated or unsaturated, straight or branched or cyclic. Among them, the straight hydrocarbon is preferable. Having the hydrocarbon group within the molecule allows for easy treatment as it can be dissolved in a general-purpose solvent, which may help with cost reductions.
The R of the branched aliphatic diester is preferably a fluorinated carbon group or a hydrocarbon group with 6 to 18 carbon atoms. To reduce the surface free energy and to obtain favorable lubrication characteristics, a fluorinated hydrocarbon group is desirable. Furthermore, to obtain lubrication characteristics, it preferably has 6 or more carbon atoms, but no more than 18 carbon atoms. Nineteen or more carbon atoms cause an undesirable increase in the viscosity of the lubricant. The hydrocarbon or fluorinated hydrocarbon group may be a straight or branched group, and a straight hydrocarbon or fluorinated hydrocarbon group is preferable.
The branched aliphatic diester used in the present invention preferably has at least 20 carbon atoms in total. When the total number of constituent carbon atoms is 19 or less, a reduction in the lubrication occurs due to evaporation, and the sliding characteristics at high temperatures and after maintaining high temperatures are insufficient. More desirable are no fewer than 24 but no more than 130 carbon atoms.
The branched aliphatic diester may be synthesized by any process. As an example of an industrially viable synthesis, it can simply be synthesized by the reaction of, for example, a diol with a chloride of a tertiary fatty acid, or a dicarboxylic acid with a tertiary alcohol.
For this, as a diol, the following compounds can be used:
1H,1H,2H,3H, 3H-perfluorononane-1,2-diol, 1H,1H,2H,3H,3H-perfluoroundecane-1,2-diol, 1H,1H,6H,6H-perfluoro-1,6-hexanediol, 1H,1H,8H,8H-perfluoro-1,8-octanediol, 1H,1H,10H,10H-perfluoro-1,10-decanediol, 1H,1H,12H,12H-perfluoro-1,12-dodecanediol, 2,2-bis(4-hydroxyphenyl)-hexafluoropropane (F-TECH Co., Ltd. or HYDRUS Chemicals Ltd.), FOMBLIN Z DOL (AUSIMONT), 1,8-octanediol, 1,10-decanediol or 1,12-dodecanediol, and the like.
As the tertiary fatty acid, the following products may be used industrially:
Versatic 5, Versatic 10, Versatic 911, and Versatic 1516 (all available from Shell Company Ltd.); Ekacid 9 and Ekacid 13 (all available from Idemitsu Petrochemical Co., Ltd.); neodecanoic acid (available from Exxon); and the like. These tertiary fatty acids (except neodecanoic acid) are mixtures of the following tertiary fatty acids: 2-isopropyl-2,3-dimethylheptanoic acid; 2-ethyl-2,3,3-trimethylbutanoic acid; 2,2,4,4,-tetramethylpentanoic acid; 2,2,3,4-tetramethylpentanoic acid; 2,2,3,3-tetramethylpentanoic acid; 2-isopropyl-2,3,5,5-tetramethylhexanoic acid; 2,3,4-trimethyl-2-neopentylpentanoic acid; 2,2,4,4,6,6-hexamethylheptanoic acid; 2,4,4-trimethyl-2-tert-pentylpentanoic acid; 2-ethyl-2,3,3,5,5-pentamethylhexanoic acid; and so on.
Perfluorosebacic acid and perfluoro-1,10-decane dicarboxylic acid (available from HYDRUS Chemical Co., Ltd.), 1,8-octanedicarboxylic acid, 1,10-decanedicarboxylic acid, 1,12-dodecanedicarboxylic acid, and the like can be used as the dicarboxylic acid. 2-Methyl-2-pentanol and 2-methyl-2-hexanol and the like can be used as the tertiary aliphatic alcohol.
Furthermore, when an aliphatic amine of the general formula
R.sub.7 N(R.sub.8)R.sub.9
wherein R 7 , R 8 and R 9 are the same as defined is added to the branched aliphatic diester, then there may be an improvement in the sliding properties under high temperature and pressure.
Examples of the aliphatic amine are laurylamine, stearylamine, oleylamine, dilaurylamine, distearylamine, dioleylamine, phenyldodecylamine, N-methylstearylamine, N,N-dimethylstearylamine, tridodecylamine, tridecylamine, trioctylamine, or the like. Among them, stearylamine, oleylamine, and N,N-dimethylamine are more desirable.
The aliphatic amine is preferably added in a molar ratio of the aliphatic amine to the branched aliphatic diester of between 100:1 and 0.01:1, and more preferably in a ratio of between 10:1 and 0.1:1 respectively.
The branched aliphatic diester, or a lubricant comprising a branched aliphatic diester and an aliphatic amine may be used together with other lubricants where necessary. For example, they may be suitably used together with generally used lubricants such as fatty acids or their metal salts, aliphatic diesters, aliphatic amides, aliphatic alcohols, monosulfides, paraffins, silicone compounds, esters of aliphatic compounds and fluorides, perfluoropolyether, polytetrafluoroethylene, and the like. In this case, the general lubricant is preferably added to the branched aliphatic diester or to the lubricant comprising a branched aliphatic diester and an aliphatic amine, in a molar ratio of between 100:1 and 0.01:1, and more desirably in a molar ratio of between 10:1 and 0.1:1 respectively.
Furthermore, the lubricants may also be used together with phosphorus extreme pressure agents such as trioleyl phosphate, sulfur extreme pressure agents such as benzyl disulfide, halogen extreme pressure agents such as allyl bromide, and organometallic extreme pressure agents such as zinc di-isobutyl dithiophosphate, and the like.
When the lubricant is provided on the magnetic recording layer or the protective membrane, it is dissolved in a general-purpose solvent such as an alcohol, a hydrocarbon, a ketone, an ether, or the like, and this solution is applied or sprayed onto the pre-formed magnetic layer or the protective membrane, and then dried. Alternatively, the magnetic layer or the protective membrane is immersed in the above-mentioned solution and then dried.
For this, the following can be given as specific examples of a general-purpose organic solvent: n-hexane, heptane, octane, decane, dodecane, benzene, toluene, xylene, cyclohexane, methyl ethyl ketone, methyl isobutyl ketone, methanol, ethanol, isopropanol, diethyl ether, tetrahydrofuran, and cyclohexanone.
When the magnetic layer is a ferromagnetic metal thin film layer, a protective membrane may be formed on top of the ferromagnetic metal thin film layer by vacuum deposition, sputtering, or plasma coating, etc. This protective membrane may be an inorganic membrane comprising carbon, silicon dioxide, zirconium oxide, chromium oxide or an organic membrane. Moreover, the ferromagnetic metal thin film layer may also have a very small amount of water adhered on its surface and/or may be coated with rust proofing agents such as benzotriazole, etc.
Furthermore, the surface of the protective membrane may undergo oxygen and ammonia plasma treatment. With plasma treatment, while the protective membrane surface is being purified, chemically active species within the plasma can accumulate and the lubricants can become more stable without reducing the hardness of the protective membrane.
The lubricants can be made more stable through the treatment with glow discharge, ultraviolet irradiation, and heat treatments, and so on. These treatments may be conducted before or after the adhesion of the lubricants. Furthermore, they may even be conducted after the rinsing off with solvents of any excess lubricant after the adhesion of the lubricants.
In the case of a coating type magnetic recording media, the lubricant may be applied by coating, spraying or immersion as described above. Alternatively, the lubricant can be added to the magnetic layer by blended the lubricant with a magnetic powder, binder resins, and organic solvents, along with other additives to make up the magnetic paint, applying this magnetic paint on top of a non-magnetic support by a suitable method, and then drying it.
An additional lubricant may be applied on top of the magnetic layer which has been thus constructed using the same methods mentioned above such as coating, spraying, immersion, and so on of the solutions containing the dissolved lubricant.
Any excess lubricant may be washed off with a solvent after adhesion. Furthermore, the lubricant may be applied on the opposite side of the magnetic layer, and transferred to the magnetic layer side.
The amount of the lubricants applied on top of the ferromagnetic metal thin film layer is preferably in the range of 0.5 to 20 mg/m 2 relative to the surface of the ferromagnetic metal thin film layer. When the lubricants are contained in the magnetic layer, the amount of the lubricant is within the range of 10-100 mg/m 2 . With an amount of less than the lower limit, it is difficult to adhere the layer of lubricant evenly onto the surface of the ferromagnetic metal thin membrane layer and a sufficient improvement in the still durability cannot be obtained. Too much is also undesirable as it causes sticking between the magnetic head and the ferromagnetic metal thin film layer.
The amounts of lubricants applied and/or contained can be evaluated by immersing a magnetic tape, to which the lubricant has been applied in a solvent overnight, and then analyzing the extracted lubricant in the solvent by gas or liquid chromatography, or the like.
Plastics, such as polyethylene terephthalate, polyethylene naphthalate, polycarbonate, polyamide, polyimide, polyvinyl chloride, and the like, or aluminum or titanium alloys may be used as suitable non-magnetic supports. The non-magnetic support may be in any form, such as tapes, sheets, discs, cards, and so on, and it may even have lumps on the surface.
For the ferromagnetic metal thin film layer, the magnetic layer is formed from Co, Ni, Fe, Co--Ni, Co--Cr, Co--P, Co--Ni--P, Fe--Co--B, Fe--Co--Ni, Co--Ni--Fe--B, Fe--Ni, Fe--Co, Co--Pt, Co--Ni--Pt or various ferromagnetic materials made from the addition of oxygen to the above metal or alloys. These are adhered onto one or both sides of a non-magnetic support by a process such as vapor deposition, ion-plating, sputtering, plating, and the final thickness of the metal thin film layer is usually in the range of 0.03 μm and 1 μm.
For the coating type magnetic layer, it is formed according to the following process. A magnetic paint is prepared as a dispersion mixture of magnetic powder, binder resin, and organic solvent as well as other additives. This magnetic paint is applied onto a non-magnetic support by a suitable method such as spraying or roll coating or the like and then dried. The final thickness of the metal thin film layer is normally in the range of 0.05-10 μm.
As the magnetic powder for this, all magnetic powders known in the prior art may be used. Examples are oxide magnetic powders such as γ--Fe 2 O 3 , Fe 3 O 4 , an intermediate iron oxides of γ--Fe 2 O 3 and Fe 3 O 4 , Co-containing γ--Fe 2 O 3 , Co-containing γ--Fe 3 O 4 , CrO 2 , and barium ferrite, etc.; metal magnetic powders such as Fe, Co, and Fe--Ni--Cr alloys, etc.; and nitride type magnetic powders such as iron nitride, etc. For needle-like magnetic powders, those with an average particle size (major axis) normally in the range of 0.05-1 μm and an average axial ratio (average major axis length/average minor axis length) normally in the range of 5-10 are preferably used. For plate-like magnetic powders, those with an average major axis length normally in the range of 0.07-0.3 μm is preferably used.
As the binder resins, any binder resins used in magnetic recording media may be used. Examples are vinyl chloride-vinyl acetate copolymer, cellulose resin, polyurethane resin, polyester resin, polyvinyl butyral resin, polyacrylic resin, epoxy resin, phenol resin, polyisocyanate compounds, and the like.
All suitable solvents which will dissolve the binder resin, such as cyclohexane, methyl ethyl ketone, methyl isobutyl ketone, ethyl acetate, benzene, toluene, xylene, tetrahydrofuran, dioxane, and the like, can be used without any particular limitation. They may be used as a single solvent or a mixture of two or more
Any other additives that are usually used in magnetic paint may also be used, for example, abrasive powders, anti-static agents, dispersants, colorants, and the like.
When the magnetic layer is formed only on one side of the non-magnetic support, a backing coat layer may be formed on the opposite side. The backing coat layer is formed by preparing a dispersion mixture as a paint which contains a non-magnetic powder such as carbon black or calcium carbonate and a binder resin such as vinyl chloride-vinyl acetate copolymer, polyurethane resin, cellulose resin or the like in an organic solvent. This paint is applied to the opposite side of the non-magnetic support and dried.
EXAMPLES
The present invention will be explained with the following examples. However, these are only representative of practical application examples of magnetic recording media, and the uses, manufacturing methods, or substances of the invention are obviously not limited thereto. Furthermore, the branched aliphatic diesters 1 to 8 used in each example were manufactured according to the Preparation Examples 1 to 8 below.
Fourier transform infra-red spectrometer (PI-1000 manufactured by Mattson) was used in the identification of the prepared branched aliphatic diesters.
Preparation Example 1
Versatic 10 (1.2 moles) and thionyl chloride (1.4 moles) were introduced into a round-bottomed flask and allowed to react in benzene as a solvent at 70° C. for 12 hours. After cooling, the reaction mixture was distilled under reduced pressure, and the acid chloride of Versatic 10 was obtained.
Then, a diethyl ether solution of the acid chloride obtained above (1.0 mole) was slowly dropwise added into a diethyl ether solution of 1H,1H,10H,10H-perfluoro-1,10-decanediol (0.4 mole) and pyridine (1.0 mole). On completion of the addition, a reaction was conducted at 40° C. for 24 hours. After cooling, the diethyl ether solvent was distilled off. After that, the product was washed with water and purified by a reduced pressure distillation to obtain the desired branched aliphatic diester 1.
The IR spectrum of the diester 1 is shown in FIG. 1, which confirms the production of the desired diester since the peak assigned to the ester linkage was found around 1740 cm -1 .
Preparation Example 2
Neodecanoic acid (1.2 moles) and thionyl chloride (1.4 moles) were introduced into a round-bottomed flask and allowed to react in benzene as a solvent at 70° C. for 12 hours. After cooling, the reaction mixture was distilled under reduced pressure, and an acid chloride of neodecanoic acid was obtained.
Then, a diethyl ether solution of the acid chloride obtained above (1.0 mole) was slowly dropwise added into a diethyl ether solution of 1H,1H,10H,10H-perfluoro-1,10-decanediol (0.4 mole) and pyridine (1.0 mole). On completion of the addition, a reaction was conducted at 40° C. for 24 hours. After cooling, the diethyl ether solvent was distilled off. After that, the product was washed with water and purified by a reduced pressure distillation to obtain the desired branched aliphatic diester 2. The production of the desired product was confirmed by the IR spectroscopy as in Example 1.
Preparation Example 3
Ekacid 13 (1.2 moles) and thionyl chloride (1.4 moles) were introduced into a round-bottomed flask and allowed to react in benzene as a solvent at 70° C. for 12 hours. After cooling, the reaction mixture was distilled under reduced pressure, and an acid chloride of Ekacid 13 was obtained.
Then, a diethyl ether solution of the acid chloride obtained above (1.0 mole) was slowly dropwise added into a diethyl ether solution of 1H,1H,10H,10H-perfluoro-1,10-decanediol (0.4 mole) and pyridine (1.0 mole). On completion of the addition, a reaction was conducted at 40° C. for 24 hours. After cooling, the diethyl ether solvent was distilled off. After that, the product was washed with water and purified by a reduced pressure distillation to obtain the desired branched aliphatic diester 3. The production of the desired product was confirmed by the IR spectroscopy as in Example 1.
Preparation Example 4
Versatic 10 (1.2 moles) and thionyl chloride (1.4 moles) were introduced into a round-bottomed flask and allowed to react in benzene as a solvent at 70° C. for 12 hours. After cooling, the reaction mixture was distilled under reduced pressure, and an acid chloride of Versatic 10 was obtained.
Then, a diethyl ether solution of the acid chloride obtained above (1.0 mole) was slowly dropwise added into a diethyl ether solution of 1H,1H,12H,12H-perfluoro-1,12-dodecanediol (0.4 mole) and pyridine (1.0 mole). On completion of the addition, a reaction was conducted at 40° C. for 24 hours. After cooling, the diethyl ether solvent was distilled off. After that, the product was washed with water and purified by a reduced pressure distillation to obtain the desired branched aliphatic diester 4. The production of the desired product was confirmed by the IR spectroscopy as in Example 1.
Preparation Example 5
Versatic 10 (1.2 moles) and thionyl chloride (1.4 moles) were introduced into a round-bottomed flask and allowed to react in benzene as a solvent at 70° C. for 12 hours. After cooling, the reaction mixture was distilled under reduced pressure, and an acid chloride of Versatic 10 was obtained.
Then, a diethyl ether solution of the acid chloride obtained above (1.0 mole) was slowly dropwise added into a diethyl ether solution of 1H,1H,2H,3H,3H-perfluorononane-1,2-diol (0.4 mole) and pyridine (1.0 mole). On completion of the addition, a reaction was conducted at 40° C. for 24 hours. After cooling, the diethyl ether solvent was distilled off. After that, the product was washed with water and purified by a reduced pressure distillation to obtain the desired branched aliphatic diester 5. The production of the desired product was confirmed by the IR spectroscopy as in Example 1.
Preparation Example 6
Versatic 10 (1.2 moles) and thionyl chloride (1.4 moles) were introduced into a round-bottomed flask and allowed to react in benzene as a solvent at 70° C. for 12 hours. After cooling, the reaction mixture was distilled under reduced pressure, and an acid chloride of Versatic 10 was obtained.
Then, a diethyl ether solution of the acid chloride obtained above (1.0 mole) was slowly dropwise added into a diethyl ether solution of 1H,1H,2H,3H,3H-perfluoroundecane-1,2-diol (0.4 mole) and pyridine (1.0 mole). On completion of the addition, a reaction was conducted at 40° C. for 24 hours. After cooling, the diethyl ether solvent was distilled off. After that, the product was washed with water and purified by a reduced pressure distillation to obtain the desired branched aliphatic diester 6. The production of the desired product was confirmed by the IR spectroscopy as in Example 1.
Preparation Example 7
Versatic 10 (1.2 moles) and thionyl chloride (1.4 moles) were introduced into a round-bottomed flask and allowed to react in benzene as a solvent at 70° C. for 12 hours. After cooling, the reaction mixture was distilled under reduced pressure, and an acid chloride of Versatic 10 was obtained.
Then, a diethyl ether solution of the acid chloride obtained above (1.0 mole) was slowly dropwise added into a diethyl ether solution of 1,10-decanediol (0.4 mole) and pyridine (1.0 mole). On completion of the addition, a reaction was conducted at 40° C. for 24 hours. After cooling, the diethyl ether solvent was distilled off. After that, the product was washed with water and purified by a reduced pressure distillation to obtain the desired branched aliphatic diester 7. The production of the desired product was confirmed by the IR spectroscopy as in Example 1.
Preparation Example 8
Tert-butylacetic acid (1.2 moles) and thionyl chloride (1.4 moles) were introduced into a round-bottomed flask and allowed to react in benzene as a solvent at 70° C. for 12 hours. After cooling, the reaction mixture was distilled under reduced pressure, and an acid chloride of tert-butylacetic acid was obtained.
Then, a diethyl ether solution of the acid chloride obtained above (1.0 mole) was slowly dropwise added into a diethyl ether solution of 1H,1H,10H,10H-perfluoro-1,10-decanediol (0.4 mole) and pyridine (1.0 mole). On completion of the addition, a reaction was conducted at 40° C. for 24 hours. After cooling, the diethyl ether solvent was distilled off. After that, the product was washed with water and purified by a reduced pressure distillation to obtain the desired branched aliphatic diester 8. The production of the desired product was confirmed by the IR spectroscopy.
Examples 1-16 and Comparative Examples 1-3
A 0.15 pm thick ferromagnetic metal thin film made from Co--O was formed by oblique vapor deposition of cobalt (Co) in an oxygen atmosphere on top of a 6 μm thick polyethylene terephthalate film. After that, a 20 μm thick DLC (diamond-like carbon) protective membrane was formed by the plasma polymerization method using an RF of 13.56 MHz along with ethylene as a monomer gas and hydrogen as a carrier gas. Finally, the product was cut to a width of 8 mm.
Next, each of the lubricants shown in Table 1 was dissolved in a mixed solvent of n-hexane, methyl ethyl ketone, and isopropyl alcohol in a volume ratio of 7:2:1 to give a concentration of 0.2 wt. %. (When an aliphatic amine was added, the aliphatic amine concentration was 0.05 wt. %.) The above-mentioned tape was immersed in and coated with the lubricant solution and then dried to give each of the videotapes having a lubricant coating on top of the DLC protective membrane.
The lubricants A, B and C used in Comparative Examples were as follows:
Lubricant A: 1,1-dihydroperfluorobutyl 2-isopropyl-2,3-dimethylbutanoate
Lubricant B: H (CH 2 ) 6 COOCH 2 (CF 2 ) 8 CH 2 OCO(CH 2 ) 6 H
Lubricant C: C 9 H 19 COOCH 2 (CF 2 ) 2 CH 2 OCOC 9 H 19 (C 9 H 19 being a mixture of branched isomer)
With each of the videotapes, still durability, a coefficient of friction and magnetic head-smudging were measured or evaluated as follows for the evaluation of lubricating properties:
<Still durability>
Each of the videotapes obtained in the Examples and Comparative Examples was preserved for 168 hours at 60° C. and 80% RH. Then, it was set at a winding angle of 220° around a 4 cm diameter cylinder for 8 mm videotapes at 20° C. and 50% RH.
Then, the playback output was measured in the still mode having recorded a sine wave with a wavelength of 1.6 μm with a tape tension of 12.5 gf/cm and a videotape/magnetic head relative speed of 11.3 m/s. The still life span was taken as the time when the playback output was reduced to half the initial value.
<Coefficient of friction>
Each of the videotapes obtained in the Examples and Comparative Examples was preserved for 168 hours at 60° C. and 80% RH. Then, the coefficient of friction was determined on the twentieth cycle of a reciprocal sliding test with a counter stainless steel pin at 20° C. and 50% RH and with a sliding speed of 1 m/min, a sliding distance of 5 cm and a tension of 20 g for 20 cycles.
<Magnetic head-smudging>
After each of the videotapes obtained in the Examples and Comparative Examples had been preserved at 60° C. and 80% RH for 168 hours, 50 cm of each videotape was evaluated after traversing repeatedly for 100 times at 20° C. and 50% RH in an 8 mm VCR (EV-S900, manufactured by Sony). The magnetic head-smudging was evaluated as follows:
A: no head-smudging
B: some head-smudging
C: substantial head-smudging.
The results are shown in Table 1.
TABLE 1______________________________________Lubricant Still Branched dura- Magnetic Ex. aliphatic Aliphatic bility Coefficient head- No. diester amine (min.) of friction smudging______________________________________1 1 -- >180 0.24 A 2 2 -- >180 0.23 A 3 3 -- >180 0.26 A 4 4 -- >200 0.28 A 5 5 -- >200 0.23 A 6 6 -- >200 0.26 A 7 7 -- >160 0.28 A 8 8 -- >120 0.30 B 9 1 Stearylamine >180 0.20 A 10 1 N,N-Dimethyl- >180 0.22 A stearylamine 11 5 Stearylamine >200 0.22 A 12 5 N,N-Dimethyl- >220 0.24 A stearylamine 13 7 Stearylamine >200 0.25 A 14 7 N,N-Dimethyl- >200 0.27 A stearylamineC. 1 Lubricant A 20 0.25 B C. 2 Lubricant B 120 0.30 C C. 3 Lubricant C 40 0.27 B______________________________________
Examples 15-28 and Comparative Examples 4-6
A 0.15 μm thick ferromagnetic metal thin film made from Co--Ni--O [Co:Ni (weight ratio)=80:20] was formed by the oblique vapor deposition of Co--Ni on a 10 μm thick ethylene terephthalate film under an oxygen atmosphere, and then cut to a width of 8 mm.
Then, each of the lubricants shown in Table 2 was dissolved in a mixed solvent of n-hexane, methyl ethyl ketone, and isopropyl alcohol in a volume ratio of 7:2:1 to give a concentration of 0.2 wt. %. (When an aliphatic amine was added, the concentration of the aliphatic amine was 0.05 wt. %.) The above-mentioned tape was immersed in the lubricant solution and the respective videotapes having a lubricant coating on the ferromagnetic metal thin film layer made.
With each of the videotapes, still durability, a coefficient of friction and magnetic head-smudging were measured in the same manners as described above. The results are shown in Table 2.
TABLE 2______________________________________Lubricant Still Branched dura- Magnetic Ex. aliphatic Aliphatic bility Coefficient head- No. diester amine (min.) of friction smudging______________________________________15 1 -- >120 0.26 A 16 2 -- >140 0.25 A 17 3 -- >120 0.24 A 18 4 -- >140 0.25 A 19 5 -- >140 0.23 A 20 6 -- >140 0.23 A 21 7 -- >140 0.28 A 22 8 -- >100 0.28 B 23 1 Stearylamine >140 0.21 A 24 1 N,N-Dimethyl- >140 0.22 A stearylamine 25 5 Stearylamine >140 0.22 A 26 5 N,N-Dimethyl- >140 0.24 A stearylamine 27 7 Stearylamine >120 0.25 A 28 7 N,N-Dimethyl- >120 0.25 A stearylamineC. 4 Lubricant A 15 0.26 B C. 5 Lubricant B 45 0.28 C C. 6 Lubricant C 20 0.30 B______________________________________
Examples 29-44 and Comparative Examples 7-9
A magnetic paint was prepared by mixing and dispersing α--Fe magnetic powder (coercive force, 1500 Oe; saturation magnetization, 120 emu/g) (100 wt. parts), a vinyl chloride-vinyl acetate-vinyl alcohol copolymer (VAGH of UCC) (20 wt. parts), a polyfunctional isocyanate compound (5 wt. parts), carbon black (3 wt. parts), α--Al 2 O 3 powder (3 wt. parts), myristic acid (2 wt. parts), cyclohexanone (150 wt. parts) and toluene (130 wt. parts), in a ball mill for 72 hours.
Then, the magnetic paint was applied onto a 15 μm thick polyethylene terephthalate film so that it would have a thickness of 5 μm after drying. The film was then dried and a magnetic layer formed. After calendering, it was cut into 8-mm widths.
Then, each of the lubricants shown in Table 3 was dissolved in n-hexane, methyl ethyl ketone, and isopropyl alcohol in a volume ratio of 7:2:1 to give a concentration of 0.2 wt. %. (When an aliphatic amine was added, the concentration of the aliphatic amine was 0.05 wt. %.) The above-mentioned tape was immersed into the lubricant solution, dried, and thus each of the videotapes having a lubricant coat on the magnetic layer was made.
With each of the videotapes, still durability, a coefficient of friction and magnetic head-smudging were measured in the same manners as described above. The results are shown in Table 3.
TABLE 3______________________________________Lubricant Still Branched dura- Magnetic Ex. aliphatic Aliphatic bility Coefficient head- No. diester amine (min.) of friction smudging______________________________________29 1 -- >220 0.23 A 30 2 -- >220 0.24 A 31 3 -- >220 0.25 A 32 4 -- >240 0.26 A 33 5 -- >240 0.23 A 34 6 -- >240 0.23 A 35 7 -- >220 0.27 A 36 8 -- >180 0.28 B 37 1 Stearylamine >220 0.20 A 38 1 N,N-Dimethyl- >240 0.23 A stearylamine 39 5 Stearylamine >240 0.23 A 40 5 N,N-Dimethyl- >240 0.23 A stearylamine 41 7 Stearylamine >220 0.24 A 42 7 N,N-Dimethyl- >240 0.25 A stearylamineC. 7 Lubricant A 30 0.25 B C. 8 Lubricant B 100 0.29 C C. 9 Lubricant C 20 0.32 B______________________________________
As can be clearly seen from the results in Tables 1, 2 and 3, all the videotapes of Examples 1-42 had the still durability and coefficient of friction which were the same or better than those of the videotapes of comparative Examples 1-9 which used the conventional lubricants. Thus, the videotapes of the present invention have good cation properties.
Furthermore, the videotapes of Examples 1-42 caused magnetic head-smudging. | A lubricant containing a branched aliphatic diester of the general formula: R 1 R 2 R 3 C--(CH 2 ) n --X--R--X'--(CH 2 ) n --CR 4 R 5 R 6 in which R 1 to R 6 independently represent a hydrocarbon group having 1-18 carbon atoms; R is a fluorinated hydrocarbon group having 6 to 18 carbon atoms; either one of X and X' represent either one of --OCO-- and --COO--, while the other of X and X' represent the other of --OCO-- and --COO--; and n is an integer from 0 to 6, and optionally an aliphatic amine of the general formula: R 7 NR 8 R 9 in which R 7 , R 8 and R 9 independently represent a hydrogen atom or a hydrocarbon group having 1 to 26 carbon atoms. | 2 |
TECHNICAL FIELD
This invention is a baluster or spindle which has its primary use in railings, such as in outdoor decks and the like. It includes railing posts and fully constructed railings using the balusters.
BACKGROUND OF THE INVENTION
While balusters or spindles for deck and porch railings continue to be made of wood, the use of synthetic resins has many advantages, such as a reduction in or elimination of the necessity for painting or otherwise coating, good weatherability, excellent wear, good appearance, versatility of design, and inexpensive production. Wood may crack over time, frequently is chemically treated to prevent microbial and insect infestation, and can require frequent protective coatings. Combinations of angular and round surfaces are rare because the round parts must be individually turned on a lathe. In addition, wood naturally comes with inevitable imperfections such as knots and grain separation.
One of the negative aspects of using synthetic resins has been the more or less arbitrary prohibition and/or regulation of synthetic resin spindles on the theory that small children can distort them, sometimes pinching themselves between the spindles or otherwise injuring themselves. Although synthetic resins have wide ranges of tensile strength, impact resistance, stiffness and other relevant properties, regulatory agencies and sometimes the customers themselves may simply ignore the differences and assume that "plastic" is inferior. Accordingly there is a need for a synthetic resin spindle which is manifestly rigid.
Ease and particularly versatility of assembly are other attributes sought for spindles for railings. It would be desirable, for example, to be able to make railings of some variation in height using a spindle of a standard design.
It is known to encase a reinforcing member within a synthetic resin body. See, for example, Lemelson U.S. Pat. No. 4,043,721.
In U.S. Pat. No. 3,200,554, Goodman et al encase a metal tube in wood (saying plastic may be used also) to make a lamp pole. The encasement is accomplished by fabrication, however, not in a mold as in the present invention.
Bajorek et al, in U.S. Pat. Nos. 4,035,978 and 4,038,802, also fabricate covers for bars, spindles, or balusters. The covers have two sections having mating surfaces, in one case longitudinal and in the other sectional. Such a construction does not intimately embed the reinforcing rod or tube as does applicant's.
In Design Pat. No. 315,415, Anthony illustrates a "decorative vertical support" having a profile with a round central portion and two square end portions. This may be of interest to the reader because applicant's preferred end portions are also substantially square, but they are separate sleeves designed to pass over the ends of the reinforced portion.
SUMMARY OF THE INVENTION
Our invention is a synthetic resin spindle or baluster having at least two parts, the main body of which encases a metal or other rigid rod or tube for reinforcement. The parts are easily assembled by simple insertion of the ends of the main body into sleeves; the sleeves are then inserted into sockets of complementary profiles, usually routed into the upper and lower rails.
Because our reinforcement rod or tube extends substantially throughout the length of the main body of the spindle, i.e. well into its end portions which are inserted into the synthetic resin sleeves, it has improved strength after assembly.
The main body of the spindle is preferably injection molded and the other parts may be extruded. Injection molding of the main body is conducted so as to ensure that the rigid rod is and remains in the correct place during the molding process. This is accomplished preferably through the use of magnets; accordingly in the preferred process and spindle construction, the reinforcing rod or tube is made of a magnetic-responsive material, generally steel.
The main body of the spindle may also be compression molded and/or formed using a clam shell mold following the continuous extrusion of a strand surrounding a more or less continuous length of rod or tube which is later cut into the appropriate lengths. In a preferred compression-molding process, a reinforcing tube is held in place by a mandrel extending throughout its length and protruding from the mold at both ends; the ends may be trimmed after the synthetic material is set.
BRIEF DESCRIPTION OF THE DRAWINGS
In the drawings, FIG. 1 illustrates the main body of the spindle reinforced by a rod.
FIG. 2 shows an end piece juxtaposed next to an insert from the main body of the spindle.
FIG. 3 shows an assembled end of the spindle of our invention.
FIG. 4 is a railing of our invention in the process of assembly.
FIG. 5 shows the magnets holding a reinforcing tube in preparation for closing the mold prior to injection molding.
In FIGS. 6a, 6b, and 6c, another advantage of our invention is shown in that spindles of configurations more complex than simple straight poles are easily made.
FIG. 7 illustrates a variation of our invention requiring only one sleeve.
DETAILED DESCRIPTION OF THE INVENTION
Referring now to the drawings, in FIG. 1, the main body 1 is seen to be an elongated member which has a central design portion 2 terminating in ledges 3 and 4 which also define the limit of insert portions 5 and 6. Main body 1 is made of synthetic resin material, which encases reinforcing rod 7. By encasing the reinforcing rod or tube, we mean that a length of the reinforcing rod or tube is intimately in contact with the synthetic thermoplastic resin when the mold is filled with molten thermoplastic resin and continues to be intimately in contact with it after the resin solidifies. Encasement does not need to be continuous throughout the entire length of the reinforcing rod or tube, but the surface area of the rod or tube which is intimately in contact with the resin should be sufficient to provide substantial reinforcement to the finished structure. Reinforcing rod 7 may be of steel or other rigid material; it extends substantially throughout the length of main body 1. It will be understood that reinforcing rod 7 may be hollow, i.e. in the nature of a tube; it may also be equipped with appendages or rough surfaces to enhance its grip on the plastic.
In this preferred version, both insert portions 5 and 6 are present. They have profiles which are complementary to the internal profiles of a sleeve such as illustrated in FIG. 2. Magnet holes 37 are left in the insert portions 5 and 6 by magnets used during the molding process, as will be further illustrated below.
In FIG. 2, sleeve 8 is seen ready to receive insert portion 6 of main body 1. Sleeve 8 is preferably extruded, and has an internal profile 9 similar to and complementary to the external profile of insert portion 6. Insert portion 5 (FIG. 1) may be inserted into a second sleeve. It will be observed that the sleeves may be manufactured of different lengths in order to vary the height of the railing, i.e. the vertical distance between the upper railing and the lower railing.
In FIG. 3, a second sleeve 10 is seen enveloping insert portion 5 of main body 1, which encases reinforcing rod 7. Sleeve 10 covers magnet holes 37.
In FIG. 4, lower sleeves 15 have been inserted into the appropriate sockets 16 in lower rail 17, and the spindles 18 have been inserted into the sleeves 15. Upper rail 19 has been moved into position for the insertion of upper sleeves 20 into sockets 21.
FIG. 5 illustrates the spindle mold half 14 having a reinforcing rod 12 held in place with magnets 13 prior to closing of the mold. The mold half 14 contains negative pattern 11 for the main body 1 (FIG. 1) of the spindle. The magnets 13 touch reinforcing rod 12 on both ends and, together with similar magnets in the other mold half, hold the rod in place during the injection molding process. They are removed after the process is complete, leaving magnet holes 37 shown in FIGS. 1 and 3. The injection molding process is performed entirely as is well known in the prior art except for the placing and holding of the reinforcing rods 12 in place--that is, a complementary mold half similar to mold half 14 is placed opposite mold half 14 to form a full cavity, the cavity is filled with molten thermoplastic, and permitted to harden, after which the mold is opened and the molded spindle removed having the reinforcing rod intact within it.
In FIG. 6, the versatility of the injection molding process is displayed. FIG. 6a shows diamond shaped frames 22 located at three different heights in spindles 23. Spindles 23 each contains a reinforcing rod or tube 32 of the appropriate shape, which may be held in place during manufacture in the mold in the same manner as in FIG. 5. FIG. 6b illustrates the ease with which curves 24 may be placed in the spindles 25 while the square profiles of the sleeves 26 ensure proper orientation of the curves. Again the appropriate rod or tube 33 is embedded in the spindle 25. FIG. 6c shows an upright unit 27 representing intersecting spindles, which may be alternated with spindles 28 having diamond frames such as in FIG. 6a. Each spindle 27 and 28 encases a rigid reinforcing tube or rod 34 of the appropriate shape. A reinforcing rod 34 is also encased in post 35 in the same manner as illustrated for spindles. Many variations in design may be envisioned. It should be noted that in each of these configurations, a rigid reinforcing member of the appropriate geometry is embedded.
FIG. 7 shows a variation in which only one sleeve, such as sleeve 10 in FIG. 3, is necessary. In this case sleeve 29 has one stub or insert end 30 for insertion into a sleeve such as sleeve 10 (FIG. 3) and one fully integral end 31 which has the appearance of a sleeve. Fully integral end 31 need not be completely filled with synthetic resin, but may contain a hollow area 40 as depicted. As with the other variations, spindle 29 is reinforced with an embedded tube or rod 35.
Our invention is seen to include a method of making a spindle comprising providing a mold having a cavity of a desired spindle design, placing therein a magnetic responsive reinforcing member, positioning said reinforcing member with magnets, closing the mold, filling the cavity with molten thermoplastic molding material, and permitting the material to harden. Upon opening the mold to release the finished spindle, the magnets may be removed.
It should be noted that our invention does not require the ends of the sleeves to have square profiles, but they may be of any profile or cross section which will suitably fit into the rail. Likewise the internal profile of the sleeve and the external profile of the ends of the spindle need not be square; they may have any practical shape. | Spindles, balusters, and railing posts are injection molded to encase reinforcing rods or tubes. Preferably the rods or tubes are magnetically responsive, which permits them to be held in place by magnets during the molding process. | 4 |
CROSS-REFERENCE TO RELATED APPLICATIONS
None.
FIELD OF INVENTION
The invention relates generally to pump-through fluid loss control devices and, more specifically, to a pump-through fluid loss control device having two one-way valves for controlling fluid flow.
BACKGROUND OF INVENTION
Electrical submersible pumps (ESP) are used in the oil and gas production industry to pump production and other fluids upwards in the wellbore in deep water applications. Some large ESPs are generally capable of pumping from 10-40 k barrels per day depending on conditions and pump specifications. Typically, positioned above the ESP, or other submersible pump, is a standing valve which prevents back-flow (downhole) into the ESP when the pump is shut-off for maintenance, injection procedures, pressure tests, bleeding off produced gas, etc. The standing valve is closed by hydrostatic head when the pump is off, provided, for example, by production fluid in the tubing. For deep water applications, the standing valve can hold a substantial differential pressure across the valve to support hydrostatic head above the ESP and, when applicable, tubing pressure from operations above the ESP. The valve opens when the pump is turned on and produces a relatively low differential pressure drop across the valve to a designed pressure value. The valve remains open for production of hydrocarbons or pumping of fluids uphole.
An ESP may see hundreds of shut-offs each year, again depending on circumstances. It is important to prevent back-flow into most pumps, since such reverse flow tends to rotate the pump backwards, damaging the pump. The standing valve must be able to seal adequately against significant hydrostatic pressure, especially in deep water wells. For example, the standing valve may have to seal against about 8,000 feet of production fluid or hold 3500 psi differential pressure. The standing valve also must withstand the tubing pressure above the valve during uphole operations.
However, it is often desirable for the standing valve to allow leakage of fluid down into the pump to lubricate and prime the pump for when it is activated. Consequently, prior art tubing standing valves, are designed to open to downward fluid flow at a selected differential pressure. For example, the valve may open to a downward fluid differential pressure of 3600-4000 psi. Typically, the pressure differential sufficient to operate the standing valve to fluid flow downward is relatively higher than the differential pressure to open the valve to upward fluid flow.
These requirements, holding against a high pressure (hydrostatic and tubing), opening at a relatively low differential upward pressure for production, and opening at a relatively high pump-down pressure for leakage, make a workable design and manufacture more difficult. For example, relatively hard materials, such as tungsten carbide, and relatively exacting tolerances, for example, at the valve seat, may be required for the valve parts to adequately seal, provide a closely defined small cross-sectional differential area for opening, etc.
Commercially available pump-through fluid loss control devices are made by Halliburton Energy Services, Inc., and sold as PES® Pump-Through Fluid Loss Control Devices. A single valve is used for both production and pump-through, with biasing spring assemblies providing for a relatively lower differential pressure to open the valve for production and a relatively higher differential pressure (pump-down pressure) to open the valve for pump-through procedures. A movable valve element seals on a movable valve seat. Pressure from the ESP below acts on the lower side of the valve element, on a cross-sectional area radially inside the seat, to move the valve upward and allow production. The valve element is biased closed when insufficient pressure is provided from below. For pump-through of fluids downward, fluid pressure is built up in the tubing string above the valve, the differential pressure acting on a narrow annular cross-sectional area of the movable seat. The seat, which is at the upper end or as a shoulder of a slidable sleeve, for example, is biased upward by a biasing mechanism. Sufficient differential pressure moves the seat downward while the valve element is prevented from similar downward movement, thereby opening the valve assembly for downward fluid flow.
The invention disclosed herein is described largely in terms of a standing valve assembly for use above an ESP, for example, in deep water wells. However, such a standing valve assembly can be employed in combination with various tool and string configurations for various purposes, as those of skill in the art will recognize. For example, the tool assembly can be used to prevent the loss of completion fluids or kill fluids and to prevent contamination of the wellbore-perforated interval.
SUMMARY OF THE INVENTION
Presented are apparatus and methods for pump-through fluid loss control. In one embodiment, the fluid loss control device is positioned in a wellbore having a first and a second one-way valve therein. The first one-way valve is openable in response to a first, selected differential pressure acting upward across the first one-way valve. For example, fluid pumped from an ESP from below the device acts to open the first one-way valve. Fluid is flowed upward through the device through the first one-way valve while the second one-way valve is closed. The first one-way valve is closed by reducing the first differential pressure across the first one-way valve, for example, by turning off the ESP. The second one-way valve is opened in response to a second, selected differential pressure acting downward across the valve. Fluid is flowed downward through the second one-way valve while the first one-way valve is closed.
BRIEF DESCRIPTION OF THE DRAWINGS
For a more complete understanding of the features and advantages of the present invention, reference is now made to the detailed description of the invention along with the accompanying figures in which corresponding numerals in the different figures refer to corresponding parts and in which:
FIG. 1 is a schematic illustration of a well system including a pump-through fluid loss control device according to an embodiment of the invention;
FIGS. 2A-C are cross-sectional views of an exemplary embodiment of the invention with the primary valve open;
FIGS. 3A-C are cross-sectional views of an exemplary embodiment of the invention with the primary valve closed;
FIG. 4 is a cross-sectional detail of an alternate embodiment of the indicated portion of FIG. 2B ;
FIG. 5 is a cross-sectional view of an embodiment of the invention taken at line 5 - 5 indicated on FIG. 3 ; and
FIG. 6 is a detail cross-section of a pressure relief valve assembly of an exemplary embodiment of the invention.
It should be understood by those skilled in the art that the use of directional terms such as above, below, upper, lower, upward, downward and the like are used in relation to the illustrative embodiments as they are depicted in the figures, the upward direction being toward the top of the corresponding figure and the downward direction being toward the bottom of the corresponding figure. Where this is not the case and a term is being used to indicate a required orientation, the Specification will state or make such clear. “Uphole,” “downhole” are used to indicate location or direction in relation to the surface, where uphole indicates relative position or movement towards the surface along the wellbore and downhole indicates relative position or movement further away from the surface along the wellbore, regardless of the wellbore orientation (unless otherwise made clear).
DETAILED DESCRIPTION OF PREFERRED EMBODIMENTS
While the making and using of various embodiments of the present invention are discussed in detail below, a practitioner of the art will appreciate that the present invention provides applicable inventive concepts which can be embodied in a variety of specific contexts. The specific embodiments discussed herein are illustrative of specific ways to make and use the invention and do not limit the scope of the present invention.
The valve device 22 is alternately referred to as a standing valve assembly, pump-through fluid loss control device, or sometimes poppet valve assembly. These alternate terms alternately refer to preferred functions and forms of the valve assembly but are not intended to be limiting, merely descriptive.
FIG. 1 is a schematic illustration of a well system, indicated generally 10 , including a standing valve assembly or pump-through fluid loss control device 22 embodying principles of the present invention. A wellbore 12 extends through various earth strata, including a production zone 20 . Wellbore 12 has installed therein casing 16 and a tool string 14 , here, a production string. A packer assembly 18 is shown positioned above the standing valve assembly 22 , sealing the annulus 24 formed between the production string 14 and wellbore casing 16 and isolating the production interval. A downhole submersible pump, such as ESP 19 , is positioned downhole from the standing valve assembly 22 for pumping production fluid from the formation to the surface.
While shown here in a cased, vertical wellbore, and used as a standing valve, the invention will work in any orientation, and in open or cased hole. It is understood that the invention can be used in various methods, including production, work-over, completion, testing, drilling, fracturing, remedial procedures, etc. It is also understood that the string shown is exemplary only and that the invention may be used in conjunction with various other tools and in other configurations, such as cross-over tools, injection tools, junk baskets, retrievable or permanent packers, wireline locks, etc.
FIGS. 2A-C and 3 A-C are cross-sectional views of an exemplary embodiment of the invention. The device 22 has two valve assemblies, a primary valve assembly 30 and a pump-through valve assembly 80 . FIGS. 2A-C show the device with the primary valve assembly 30 in an open position. FIGS. 3A-C show the device with the primary valve assembly 30 in a closed position and the pump-through valve assembly 50 in an open position (in the detail).
A downhole standing valve assembly or pump-through fluid loss control device 22 is shown having a substantially cylindrical tool housing 24 comprised of upper and lower subassemblies 26 and 28 , for connecting the tool with other sections of a tool string as is known in the art, a primary valve housing member 27 and a pump-through valve housing member 29 . The housing members 26 - 29 are connected to one another, such as by cooperating threads, snap rings, or other mechanisms known in the art. The device defines a flow passageway 25 therethrough, for example, for allowing production fluid to flow toward the surface. The device is preferably made from material capable of withstanding a high-temperature, high-pressure, and/or corrosive environment. For example, in a preferred embodiment, the metal portions of the device are made of 13 chrome stainless steel, or similar (unless specifically called out as another material). This is especially the case where the device is to left in the well for extended periods of time and expected to repetitively function (open and close) a significant number of times.
Within the housing 24 are positioned two valve assemblies, a primary valve assembly 30 and a pump-through valve assembly 80 . The device 22 is intended to be used with the upper subassembly uphole from the lower subassembly in its primary configuration. The primary valve assembly 30 includes a valve element assembly 32 and a valve seat assembly 60 .
The valve element assembly 32 , in a preferred embodiment, has a valve element 34 attached to a sleeve member 36 , as shown. The attachment 35 is shown as a threaded screw and ball bearing locking assembly, seen in FIG. 3B . Other attachment methods may be used as are known in the art. The valve element and sleeve member define a fluid passageway 37 therethrough to allow fluid flow through the valve element assembly when in the open position. In a preferred embodiment, the valve element assembly 32 is a poppet valve assembly having a substantially cylindrical wall 59 and a lower end wall 69 which encloses the lower end of the element, as shown. The valve element 36 has one or more ports 31 to allow passage of fluid between the interior and exterior of the valve element assembly 32 .
The valve element 34 has a downward facing pressure surface 38 . The relatively large surface area of the pressure surface 38 is provided so that the poppet element 34 can be moved upward off its seat with a relatively lower differential pressure. In a preferred embodiment, the valve element 34 defines an arcuate surface 39 which seats on the cooperating valve seat discussed elsewhere herein.
The valve element assembly 32 abuts a bearing 40 and is preferably attached thereto, such as with split ring 41 . The bearing is slidably mounted within the housing 24 , as shown. The bearing is preferably made of a softer material than the device housing 24 , such as an aluminum ASM CU128, or the like, such that the bearing slides easily along the interior wall of the housing 24 . The bearing preferably has feet or annular protrusions 47 which provide a limited surface area of contact between the bearing and the interior surface of the housing. An annular space 48 may be defined between the bearing and the housing. A wiper seal 49 is preferably provided between the bearing and the valve assembly, as shown, to prevent well fluids or debris from entering the bearing and biasing spring assembly. In a preferred embodiment, the wiper seal 49 is a spring-energized lip seal made of PTFE.
The bearing 40 is biased towards the closed position by a biasing member, shown as biasing spring 42 . The biasing spring 42 is positioned between the bearing 40 and a stationary spring shoulder 43 . The spring shoulder can be a profile defined by a portion of the housing 24 as shown. The biasing spring 42 provides a biasing force to maintain the valve element assembly 32 in a closed position, as seen in FIG. 3B , unless and until a fluid provides the necessary differential pressure from below on the downward facing pressure surface 38 . The valve element assembly 32 is also acted on by the hydrostatic head above the assembly. The hydrostatic head pressures downward on the upward facing surfaces of the valve assembly 32 and tends to hold the valve assembly in a closed position. The valve must hold against such hydrostatic pressure, which may be substantial, especially in deep water wells.
The biasing spring is designed and selected to compress at a known pressure, thereby providing a mechanism for opening the primary valve at a pre-selected pressure differential across the valve assembly. In a preferred embodiment, the spring holds against differential pressures of less than 15 psi from below the poppet on the pressure surface. Stated another way, the valve assembly opens, as shown in FIG. 3B , when the pressure differential across the valve is 15 psi or greater. Pressure is balanced in the spring volume 50 by fluid from the housing interior through, for example, tortuous path 52 , which allows for fluid to enter the volume but excludes debris.
Movement of the valve assembly is limited by cooperating surfaces or shoulders. Downward movement of the valve assembly is limited, in the preferred embodiment, by movement of arcuate surface 39 and valve seat assembly 60 . The shoulder 44 is a thicker surface for enhanced wear resistance. Upward movement of the valve assembly 32 is limited by the upper surface 45 of the sleeve 36 abutting the shoulder 46 which further inhibits debris from entering chamber 50 .
The valve seat assembly 60 is positioned in the device below the primary valve assembly 30 . The valve seat assembly 60 includes a valve seat 61 which is defined by an insert 62 attached to the housing 29 . The valve seat 61 is preferably a conical surface which mates with the arcuate surface of the valve element. Other seat designs may be used as are known in the art. The valve seat insert 62 attaches to the housing by threaded connectors 63 extending through collar 67 , as shown, or by other mechanisms known in the art. The insert is not strictly necessary as the seat can be formed on the housing, etc. The collar 65 defines a plurality of passageways 64 therethrough which provide fluid communication from the interior passageway of the device (above the primary valve assembly) to the pump-through valve assembly and thence, when the pump-through valve is open, to the interior passageway of the device at the lower end. The passageway through the collar is not strictly necessary either, as the passageway can be provided elsewhere, such as through the housing wall, through the insert wall, etc.
In a preferred embodiment, an impact cushion 53 is provided, as best seen in FIG. 4 , which is the detail indicated in FIG. 2B , but with an alternative embodiment shown, including a cushion insert and wiper seal. To protect the primary valve elements and to prevent early leakage through the primary valve, an impact cushion 53 is provided to cushion the impact of the metal-on-metal seal. Additionally, a secondary seal for sand 54 and a wiping surface 55 is provided. The impact cushion 53 is preferably made of plastic, such as PEEK, PTFE, etc. The impact cushion also acts as a back-up ring for a spring-energized lip seal 54 . The seal 54 further seals against fluid passing through the primary valve. The spring 56 energizes the seal element 57 and is trapped in position by stay member 58 . In a preferred embodiment, a wiping surface 55 is provided to wipe sand from the surface of the valve element as it moves to the closed position. The lip seal 54 has a surface 55 for this purpose.
The pump-through valve assembly 80 is positioned in the device below the primary valve assembly 30 , preferably. Alternate positioning will be apparent to those of skill in the art. The pump-through valve assembly 80 is shown, in a preferable embodiment, defined by and positioned in the wall of the housing 24 . Alternate embodiments will be apparent to those of skill in the art.
The pump-through valve assembly, one-way valve assembly, or pressure relief valve assembly, can be of any type known in the art, although the preferred embodiment is shown. The pump-through valve can be a check-valve, a ball check valve, a poppet valve, a swing check valve, etc.
The pump-through valve assembly 80 includes a pressure relief valve 81 , a fluid passageway 82 , and filters 83 - 85 . Passageway 82 permits fluid communication from the interior passageway 25 of the device above the pump-through valve assembly 80 to the interior passageway of the device below the assembly. In the preferred embodiment, fluid flowing through the pump-down valve assembly passes through passageway 25 of the tool, passageway 37 of the sleeve 36 and valve element 34 , the ports 31 , and into annular space 86 adjacent the pump-through valve assembly. Alternate arrangements will be recognized by those of skill in art. For example, a fluid passageway can bypass the primary valve assembly altogether, communicating fluid from above the primary valve to the pump-through valve assembly directly.
The pump-through valve assembly 80 preferably has filters 83 and 84 at the upper end of the passageway 82 . In a preferred embodiment, the filter 83 is a multi-layered, sintered wire mesh screen. Filter 84 , in a preferred embodiment, is a double filter unit safety screen, as shown. A filter 85 is also preferably provided at the lower end of the passageway, shown as a double filter unit safety screen. This filter is secured with ring 66 and screws with lock washers 65 in a preferred embodiment. Such filters are available commercially, for example, from Lee Products.
FIG. 6 is a cross-sectional detailed view of a preferred embodiment of a pressure relief valve assembly 81 insert. The check valve 81 is shown schematically in FIGS. 2-3 . The pressure relief valve can take various forms, as is known in the art, and can be an insert, as shown, or assembled piece-meal in the tool. A preferable embodiment is shown at FIG. 6 and is commercially available from, for example, the Lee Company.
The pressure relief valve 81 includes a biasing spring 86 , a valve element 87 , a valve seat 88 , and a fluid passageway 89 . The check valve 81 is designed to open with a pressure differential from above while the primary valve remains closed. For example, with the primary valve closed, the pressure relief or check valve opens at a 4000 psi differential pressure. In a preferred embodiment for an 8,000 foot setting depth, the pressure relief valve has a cracking pressure of about 4000 psi differential and a flow rate of about 4 gallons per minute at the optimal pressure differential. The pressure relief valve is seen closed in FIG. 6 . When sufficient pressure differential is supplied from above, the valve element 87 unseats from seat 88 , compressing spring 86 , and fluid flows through passageway 89 and exits the valve assembly.
The pump-through valve assembly 80 preferably includes multiple pump-through valves spaced around the annular housing wall, as seen in FIG. 5 , to provide redundancy and to provide a minimum desired flow rate when opening pressure differential is applied from above. Threaded connectors 65 can also be seen in FIG. 5 .
The purpose of the relief valves is to fill the ESP cavity 11 , that is, the tubular space above the ESP and below the fluid loss control device 22 , with fluid for pump start up so the ESP will not have to start dry. However, when filling this cavity, which may be considerable given that various equipment and tools can be located between the ESP and fluid loss control device, the downward flow rate must be relatively low so that the pump is not caused to spin backwards. The cavity may be lengthened by the placement of tools, such as flow meters, environmental parameter sensors, lower chemical injectors, screens and the like. For the sake of discussion, the ESP has a critical reverse flow rate at which the pump will be caused to spin backwards or will suffer damage due to backwards spinning. A flow rate into the outlet of the pump below the critical rate will not cause the pump to spin backwards or will not damage the pump. The relief valves 81 are selected to fill the ESP cavity without exceeding the critical reverse flow rate. The number, size, maximum and optimal flow rates, cracking pressure, etc., of the pressure relief valve assemblies can be selected to provide fluid flow below the fluid loss control device below the critical flow rate of the pump. In a preferred embodiment, for example, two pressure relief valves provide for four gallons of flow per minute, providing a total of eight gallons of flow per minute to the ESP cavity and into the ESP.
The phrase “spin the pump backwards” and similar is used herein to indicate rotation of a pump element, such as the impeller, in the reverse direction to its normal direction of rotation. It is understood that the pump unit itself does not spin but rather an element within the pump.
In use, the pump-through fluid loss control device is placed into position at a downhole location within a wellbore. For example, the device can be placed in a well as part of a completion string. In the exemplary embodiment shown, the device is placed below a packer or similar device which isolates the lower wellbore. A pump, such as an ESP, is positioned below the device. When placed in the well, the primary valve assembly provides a metal-to-metal seal to hold against hydrostatic head. The primary valve is also biased closed by a biasing spring or similar. The primary valve opens when differential pressure across the valve, pressured from below, exceeds a selected pressure. The pump is in fluid communication with the wellbore fluid in the wellbore below the packer. When turned on, the pump suctions in fluid and pumps it up the string and into the interior space of the device. Pressure will build on the pressure surface of the primary valve element. The valve element and sleeve will displace upward in response to the minimum necessary pressure differential. Wellbore fluid then flows through the open primary valve, through the element ports, and up the string. When the pump is shut down, the primary valve displaces back to the closed position. The primary valve assembly prevents fluid flow downward, thereby preventing fluid from forcing the pump to rotate in reverse, from contaminating the wellbore below the valve, etc.
Once closed, it is then possible to flow fluid past the device downward, to lubricate the ESP, to fill the string below the device, to inject fluids, etc. The fluid in the string is pressured up such that a relatively higher differential pressure acts, from above, across the pressure relief valve assembly. The pressure relief valves (or pump-through valves) are opened by tubing pressure above the valves. The pressurized fluid forces the valve open (unseats the valve element) and fluid flows through the device passageway, into the annular space adjacent the pump-through valve, through filters if installed, through the pump-through valve passageway and provides pressure to the pump-through valve element. At a selected minimum crack pressure, the pump-through valve opens, providing fluid flow into the device passageway below the valve and thence to the lower well string and pump. When tubing pressure from above is reduced, the pump-through valve is biased shut and flow ceases. The pump, now primed and lubricated, can now be turned back on.
The invention has been described primarily in relation to use above a submersible pump. Alternate uses will be apparent to those of skill in the art where pump-through fluid loss control devices will be of service.
While this invention has been described with reference to illustrative embodiments, this description is not intended to be construed in a limiting sense. Various modifications and combinations of the illustrative embodiments as well as other embodiments of the invention, will be apparent to persons skilled in the art upon reference to the description. It is, therefore, intended that the appended claims encompass any such modifications or embodiments. | Presented are apparatus and methods for pump-through fluid loss control. In one embodiment, the fluid loss control device is positioned in a wellbore having a first and a second one-way valve therein. The first one-way valve is openable in response to a first, selected differential pressure acting upward across the first one-way valve. For example, fluid pumped from an ESP from below the device acts to open the first one-way valve. Fluid is flowed upward through the device through the first one-way valve while the second one-way valve is closed. The first one-way valve is closed by reducing the first differential pressure across the first one-way valve, for example, by turning off the ESP. The second one-way valve is opened in response to a second, selected differential pressure acting downward across the valve. Fluid is flowed downward through the second one-way valve while the first one-way valve is closed. | 4 |
BACKGROUND OF INVENTION
[0001] The present invention relates generally to a virtual reality method and apparatus with improved navigation. More specifically, the present invention relates to a virtual reality method and apparatus improving navigation through the use of way-points.
[0002] Virtual reality technology in applications have progressed from hollywood-based imaginations into practical and useful applications. These applications have found utility in a wide variety of fields and industries. One known genre of applications are known as training applications. Virtual reality training applications allow users to develop important skills and experience without subjecting them to the hazards or costs of training within the industrial environment. The automotive industry has looked towards the field of virtual reality in order to train employees without subjecting them to the hazards of an automotive plant.
[0003] Virtual worlds may be utilized to familiarize employees with the plant environment, train employees on the proper use of plant equipment, and provide a detailed understanding of plant operations. In this fashion, an employee may be properly trained in a wide variety of operations, procedures, and protocols. Although the subjective content of a virtual reality world may only be limited in terms of imagination or desired reality, a users interaction with the virtual world often does not provide such flexibilities.
[0004] Difficulties arise when attempting to provide the user with effective, simplistic, and convenient interaction with the virtual reality world. One approach to improve user interaction has been through the development of high tech I/O devices. These devices run the gambit from video headgear to electronic bodysuits. Although such complex devices often succeed in improving the user's immersion into the virtual reality world, their cost and complexity can often serve to limit the use of virtual reality applications in more practical applications. In these practical applications, often a computer keyboard, monitor, and mouse or track ball may provide the sole source of communication between the user and the virtual reality world. In these scenarios, the use of such standard interface devices in combination with known methodologies has proven to create difficulties for the user in navigation to the virtual reality world.
[0005] Navigation through the virtual reality world utilizing such I/O devices, although practical, can be impractical and time-consuming when utilizing standard techniques. Users may be required to concentrate more on their placement and orientation controls than on the important training procedures the virtual reality world is intended to impart. Often such training requires the user to be positioned at precise locations within the virtual reality environment or move between sequences in such positions in order to properly glean the required knowledge. Considerable effort has been expended to control the user's response within the environment to mouse clicks or keyboard strokes, but often such controls remain over-responsive or under-responsive and thereby provide inefficient interaction. It would be highly desirable to improve the methods of navigation through the virtual reality world such that the user can quickly and efficiently reach the desired positions within the virtual environment. This would not only succeed in improving the ease of navigation, but would additionally improve the overall effectiveness of the virtual reality application.
SUMMARY OF INVENTION
[0006] It is, therefore, an object of the present invention to provide a virtual reality method of assembly with improved navigation. It is a further object of the present invention to provide a virtual reality method and assembly that allows users to navigate through the virtual reality world in a simple and efficient manner.
[0007] In accordance with the objects of the present invention, a virtual reality assembly is provided. A virtual reality assembly includes a display element for depicting the virtual reality environment. The virtual reality assembly further includes a plurality of way-point elements positioned at locations within the virtual reality environment' Navigation through the virtual reality environment is simplified through the selection of one of the way-point elements as a travel destination.
[0008] Other objects and features of the present invention will become apparent when viewed in light of the detailed description of the preferred embodiment when taken in conjunction with the attached drawings and appended claims.
BRIEF DESCRIPTION OF DRAWINGS
[0009] [0009]FIG. 1 is an illustration of an embodiment of a virtual reality assembly in accordance with the present invention;
[0010] [0010]FIG. 2 is an illustration of an alternate display view angle of the virtual reality assembly illustrated in FIG. 1; and
[0011] [0011]FIG. 3 is an illustration of the virtual reality assembly as described in FIG. 1, the illustration depicting a sample path through the virtual reality environment.
DETAILED DESCRIPTION
[0012] Referring now to FIG. 1, which is an illustration of a virtual reality assembly 10 in accordance with the present invention. The virtual reality assembly 10 includes a display element 12 . The display element 12 is illustrated as a standard computer monitor display 14 . It should be understood, however, that a wide variety of display elements 12 are contemplated by the present invention. These display elements 12 include, but are not limited to, optical projectors, virtual reality goggles, and holographic imaging. The display element 12 is utilized to project or display an image of the virtual environment 16 to the user of the virtual reality assembly 10 .
[0013] As is understood, the virtual environment 16 can be designed to represent a wide variety of environments. Although an almost infinite range of such environments is contemplated by the present invention, the virtual environment 16 is illustrated representing an automotive manufacturing plant. Similarly, it is contemplated that virtual reality assembly 10 may be utilized to serve a wide variety of applications. These applications include, but are not limited to, familiarization of the user to the automotive plant environment, training of the user in plant operations, and education of the user in safety issues and procedures. In order to accomplish such applications, it is typically necessary for the user to navigate through the virtual environment 16 , Although not necessary for the practice of the present invention, a visual representation of the user 18 may be represented within the virtual environment 16 in order to assist the user's visualization and orientation within the virtual environment 16 . The visual representation 18 may additionally be useful for adequately displaying operational procedures or safety considerations.
[0014] Traditional navigation methods through the virtual reality environment 16 have often proven time-consuming and difficult. In addition, present navigational methods can cause user fatigue and negatively effect concentration. Precise placement and/or orientation of the user 18 can be crucial for the proper operation of the virtual environment assembly 10 . The present invention improves the efficiency and ease of use of such navigation by including a plurality of way-points 20 positioned throughout the virtual reality environment 16 . Each way-point 20 defines a specific placement 22 (also referred to as way-point position 22 ) within the virtual reality environment 16 . In addition, it is contemplated that each way-point 20 may further include an orientation element 24 in addition to the way-point position 22 such that the user 18 can be moved to both a correct location and orientation. Although the way-points 20 need not be physically represented within the virtual environment 16 , one embodiment contemplates the use of way-point icons 26 within the virtual environment 16 to represent way-point 20 locations and/or orientation.
[0015] It is contemplated that the way-points 20 may be utilized in a variety of fashions in order to facilitate navigation through the virtual environment 16 . In one embodiment, a cursor 28 may be utilized to select a particular way-point 20 , thereby directing the user 18 towards that way-point position 22 and/or way-point orientation 24 (see FIG. 2.) It should be understood that the way-point icons 26 need not be utilized in order to effectuate this mode of navigation. By selecting an area within the virtual environment 16 , the virtual environment assembly 10 can direct the user 18 to the nearest way-point 20 without the need for visual way-point icons 26 .
[0016] In an alternate embodiment (see FIG. 3), the plurality of way-points 20 may be sequenced. In this embodiment, the user 18 progresses through the virtual environment 16 by automatically progressing through way-points 20 in a predetermined order. This provides further reduced control complexity and may be highly valuable in applications requiring a precise sequence of movements. It should be understood that the arrows, indicating movement, illustrated in FIG. 3, are for illustrative purposes only and need not be physically represented within the virtual environment 16 . Furthermore, the use of sequenced way-points 20 may be utilized in combination with a variety of other known directional controls in order to direct the user 18 between the sequenced way-points.
[0017] The user 18 may be directed between way-points through the use of traditional navigational controls such as an orientational control element 30 and a directional control element 32 . Although one simplistic rendering of such control has been illustrated, a wide variety of orientational controls 30 and directional controls 32 would become obvious to one skilled in the art. The orientational controls 30 and directional controls 32 can be utilized to direct the user 18 towards a specific way-point 20 . In addition, the orientational controls 30 may be utilized to allow the user 18 to visually explore the virtual environment 16 from a given position. Although these navigational controls may be accessed through a variety of known input devices, in one embodiment it is contemplated that a navigation band 34 displayed on the display element 12 may be utilized to provide the user 18 with access to navigation. In this fashion, simplistic I/O devices such as a mouse or a touch screen can be utilized to provide access to the navigational controls. This can allow a virtual reality assembly 10 to be installed in a wide variety of environments where complex I/O arrangements may be impractical.
[0018] While particular embodiments of the invention have been shown and described, numerous variations and alternative embodiments will occur to those skilled in the Accordingly, it is intended that the invention be limited only in terms of the appended claims. | A virtual reality assembly 10 is provided, including a display element 12 projecting a virtual environment 16, and a plurality of way-point elements 20 each defined by its own way-point position 22. A user 18 can automatically move to one of said way-point positions 22 by simply selecting the corresponding way-point element 20. | 6 |
CROSS REFERENCE TO RELATED APPLICATION
[0001] This application is a divisional of U.S. patent application Ser. No. 12/107,825, filed Apr. 23, 2008 the entire content and disclosure of which is incorporated herein by reference.
FIELD OF THE INVENTION
[0002] The present invention relates to a semiconductor structure, and particularly to methods for enhancing the quality of image frames from a pixel sensor array.
BACKGROUND OF THE INVENTION
[0003] A pixel sensor comprises an array of pixel sensor cells that detects two dimensional signals. Pixel sensors include image sensors, which may convert a visual image to digital data that may be represented by a picture, i.e., an image frame. The pixel sensor cells are unit devices for the conversion of the two dimensional signals, which may be a visual image, into the digital data. A common type of pixel sensors includes image sensors employed in digital cameras and optical imaging devices. Such image sensors include charge-coupled devices (CCDs) or complementary metal oxide semiconductor (CMOS) image sensors.
[0004] While complementary metal oxide semiconductor (CMOS) image sensors have been more recently developed compared to the CCDs, CMOS image sensors provide an advantage of lower power consumption, smaller size, and faster data processing than CCDs as well as direct digital output that is not available in CCDs. Also, CMOS image sensors have lower manufacturing cost compared with the CCDs since many standard semiconductor manufacturing processes may be employed to manufacture CMOS image sensors. For these reasons, commercial employment of CMOS image sensors has been steadily increasing in recent years.
[0005] For typical CMOS image sensors, the images are captured employing a “rolling shutter method.” FIG. 1 shows a typical prior art rolling shutter image capture and read out sequence. In the rolling shutter method, the imaged is captured on a row-by-row basis within a pixel array, i.e., the image is captured contemporaneously for all pixels in a row, but the capture of the image is not contemporaneous between adjacent rows. Thus, the precise time of the image capture is the same only within a row, and is different from row to row.
[0006] For each pixel in a row, the image is captured in its light conversion unit, which is a photosensitive diode. Charges generated from the light conversion unit are then transferred to a floating diffusion node. The amount of charge stored in the floating diffusion node is then read out of each pixel via a transistor wired in the source follower configuration whose gate is electrically connected the floating diffusion node. The voltage on the source of said source follower is then read out to column sample circuits, thereby completing the read out of all the pixels in the selected row, before moving on to the next row. This process is repeated until the image is captured by the pixels in all the rows, i.e., by the entire array of the pixels.
[0007] Since the same column sample circuits are employed to read out the data row by row without delay between the exposure and the read out, the read out of the rows of the image sensor is staggered between rows. Therefore, the exposure of the image sensor needs to be staggered row by row. In other words, different rows are exposed at different times. The resulting image is one where the each row captured actually represents the subject at a different time. Thus, for highly dynamic subjects (such as objects moving at a high rate of speed), the rolling shutter methodology can create image artifacts.
[0008] To solve this image artifact issue of capturing high speed objects, a global shutter method may be employed. FIG. 2 shows a typical prior art global shutter image capture and read out sequence. The global shutter method employs a global shutter operation, in which the entirety of the array of image sensors is reset prior to exposure simultaneously. The image for the whole frame is captured in the light conversion units of the pixels at the exactly same time for all the rows and columns. The signal in each light conversion unit is then transferred to a corresponding floating diffusion node. The voltage at the floating diffusion nodes is read out of the imager array on a row-by-row basis. The global shutter method enables image capture of high speed subjects without image artifacts, but introduces a concern with the global shutter efficiency of the pixel since the integrity of the signal may be compromised by any charge leakage from the floating diffusion node between the time of the image capture and the time of the reading of the imager array.
[0009] Specifically, in the rolling shutter method, the image signal is held at the floating diffusion node (FD) for a significantly shorter time than the actual time of exposure in the light conversion unit, e.g., a photodiode. Thus the contribution of the generation rate of the FD is orders of magnitude smaller than the generation rate during the integration time in the light conversion structure, e.g., the photodiode.
[0010] In contrast, the image signal is held at the FD for varying amounts of time in the global shutter method. For example, the signal from the first row may have the least wait time, which is the time needed to read out a single row. The signal from the last row has the greatest wait time which corresponds to the full frame read-out time, which is equal to the product of the number of rows in the array with the time needed to read out a single row. The charge on the floating diffusion may be degraded due to charge leakage or charge generation during the wait time for the last row. Any charge generations or charge leakage that occurs on the floating diffusion node during the wait time can have a significant impact to the quality of the signal that is read out of the imager.
[0011] Referring to FIG. 3 , a prior art CMOS pixel sensor cell comprises a semiconductor substrate 8 and a transfer gate transistor formed thereupon. The semiconductor substrate 8 comprises a heavily-doped first conductivity type semiconductor layer 10 , a lightly-doped first conductivity type semiconductor layer 12 , an isolation structure 20 which may be shallow trench isolation, LOCOS, or other semiconductor isolation, and a surface pinning layer 34 .
[0012] The heavily-doped semiconductor layer 10 comprises a heavily doped semiconductor material having a first conductivity type doping. The first conductivity type is p-type or n-type. The lightly-doped first conductivity type semiconductor layer 12 comprises a lightly-doped semiconductor material having the first conductivity type doping, which is a low concentration doping with first conductivity type dopants. The surface pinning layer 34 has a doping of the first conductivity type.
[0013] The semiconductor substrate 8 further comprises a second conductivity type charge collection well 30 . A lightly-doped first conductivity type region 32 is a portion of the lightly-doped first conductivity type semiconductor layer 12 located directly underneath the second conductivity type charge collection well 30 . The lightly-doped first conductivity type region 32 typically has the same dopant concentration as the rest of the lightly-doped first conductivity type semiconductor layer 12 .
[0014] The lightly-doped first conductivity type region 32 and the second conductivity type charge collection well 30 collectively constitute a photodiode ( 32 , 30 ) that generates electron-hole pairs. Charge carriers of the second conductivity type are collected in the second conductivity type charge collection well 30 in proportion to the amount of photons impinging into the photodiode ( 32 , 30 ). Electron-hole pairs are generated within the depletion region of the photodiode ( 32 , 30 ), due to photogeneration processes. Particularly, if the carrier is a carrier of the second conductivity type, the carrier accumulates in the second conductivity type charge collection well 30 . The amount of charge that accumulates in the second conductivity type charge collection well 30 is nearly linear to the number of incident photons (assuming the photons have the same energy distribution).
[0015] The transfer gate transistor comprises a gate dielectric 50 , a gate electrode 52 , a gate spacer 58 , a source, which is the second conductivity type charge collection well 30 , and a drain, which is herein referred to as a floating drain 40 . Specifically, the transfer gate transistor is integrally formed with the photodiode ( 30 , 32 ) such that the second conductivity type charge collection well 30 , which comprises a lightly-doped second conductivity type semiconductor material, is also a source of the transfer gate transistor. The second conductivity type is the opposite of the first conductivity type. For example, if the first conductivity type is p-type, the second conductivity type is n-type, and vice versa.
[0016] The floating drain 40 has a doping of the second conductivity type, and is electrically floating when the transfer transistor is turned off to enable storage of electrical charges. A first conductivity type well region 42 is formed by implantation of first conductivity type dopants under the floating drain 40 .
[0017] Charge carriers of the second conductivity type, which are electrons or holes, accumulate in the second conductivity type charge collection well 30 when photons are incident on the photodiode ( 32 , 30 ). When the transfer transistor is turned on, the electrons in the second conductivity type charge collection well 30 are transferred into the floating drain 40 , which is a charge collection well and stores electrical charge from the photodiode ( 30 , 32 ) as data until a read circuit detects the amount of stored charge. Thus, the second conductivity type charge collection well 30 functions as the source of the transfer transistor while the transfer transistor is turned on. The turn-on of the transfer transistor corresponds to the transfer of the entire array from photosensitive diode to floating diffusion as described in FIG. 2 .
[0018] In general, a difficulty in global shutter imaging is that the charge needs to stored in the floating diffusion 40 for a long time—up to the read out time for the entire frame which can be up to a tenth of a second or more. During this time, the leakage on the diffusion directly impacts the image quality. Obtaining high quality digital images in the global shutter operation scheme requires preservation of the charge in the floating drain 40 without any significant change in the amount of stored charge until the read out. The greater the leakage current of the floating drain, the greater the change in the amount of charge between the transfer from the second conductivity type charge collection well 30 , which is a terminal of the photosensitive diode ( 30 , 32 ), and the read out. Most leakages are time dependent and are characterized by a rate measured in an amount of charge leaked to or from the diffusion per unit time.
[0019] Since images are typically read out from top to bottom, the data from the top row of the image will be on the diffusion for a very short time before being read out and therefore very little noise will be added to this row due to leakage on the read out diffusion. This will gradually get worse to the bottom of the image. The data on the bottom row of the image will sit on the diffusion for the full read time of the frame and thus will have the largest leakage current. Thus, rolling shutter images are of worse quality at the bottom than the top. Leakage both creates a loss of contrast as well as fixed pattern noise, and both of these can be visibly worse at the bottom of the image. The human eye is very sensitive to such correlated noise and images which appear worse at one side are unacceptable for consumer photography.
[0020] Further, the amount of data distortion and the loss of image fidelity are also affected by local variations in the leakage current and the voltage at the floating drain of a CMOS pixel sensor cell, which depends on the amount of charge stored therein.
[0021] In view of the above, there exists a need to provide a method of alleviating the impact of image degradation due to the variations in the charge hold time among the different rows of an array of a CMOS image sensor operated in global shutter mode.
[0022] Further, there exists a need to provide a method for compensating for the leakage current to improve the signal-to-noise ratio of the image frame of the array of CMOS image sensors operated in global shutter mode.
SUMMARY OF THE INVENTION
[0023] To address the needs described above, the present invention provides methods for enhancing the image quality of an image frame from a complementary metal oxide semiconductor (CMOS) image sensor array.
[0024] In the present invention, the image quality of an image frame from a CMOS image sensor array may be enhanced by dispersing or randomizing the noise introduced by leakage currents from floating drains among the rows of the image frame. Further, the image quality may be improved by accounting for time dependent changes in the output of dark pixels in dark pixel rows or dark pixel columns. In addition, voltage and time dependent changes in the output of dark pixels may also be measured to provide an accurate estimate of the noise introduced to the charge held in the floating drains. Such methods may be employed individually or in combination to improve the quality of the image.
[0025] According to an aspect of the present invention, a method of operating an array of pixel sensor cells comprising:
[0026] exposing an entirety of an array of pixel sensor cells, wherein each of the pixel sensor cells contains a light conversion unit and a floating drain;
[0027] simultaneously transferring electrical charges from the light conversion unit to the floating drain in each of the array of pixel sensor cells; and
[0028] sensing the electrical charges in the floating drains one row at a time and for each row in the array, wherein a temporal order of row sensing contains a sequence of rows in which at least one pair of sequentially neighboring rows is physically non-neighboring.
[0029] In one embodiment, the temporal order of row sensing may be determined by iterative partitioning of at least one physically contiguous block of rows and selecting of a predetermined number of physically non-neighboring rows from each partition of the at least one physically contiguous blocks, wherein the selected predetermined number of physically non-neighboring rows constitute sequentially contiguous rows in the temporal order.
[0030] In another embodiment, the method may further comprise:
[0031] generating a raw image frame comprising pixels having pixel values obtained by sensing of an entirety of the array; and
[0032] generating a processed image frame by image processing, wherein pixel values of pixels of the raw image frame are locally averaged with weighting to provide processed pixel values for pixels of the processed image frame, wherein weighting of each the local pixel value correlates with a sequential location of a row to which each the local pixel belong in the temporal order of row sensing.
[0033] The weighting may comprise a distance dependent component and a sensing-order dependent component, wherein the distance dependent component is the same for a pair of pixels equal distance apart from a pixel for which processed pixel values are determined and belonging to different rows, and wherein the sensing-order component is greater for a pixel among the pair of pixels that belong to a row that is sensed earlier.
[0034] According to another aspect of the present invention, another method of operating an array of pixel sensor cells is provided, which comprises:
[0035] simultaneously exposing an entirety of an array of pixel sensor cells, wherein each of the pixel sensor cells contains a light conversion unit and a floating drain;
[0036] simultaneously transferring electrical charges from the light conversion unit to the floating drain in each of the array of pixel sensor cells; and
[0037] sensing the electrical charges in the floating drains one row at a time and for each row in the array to generate raw pixel values for each pixel sensor cell;
[0038] measuring pixel values for dark pixels multiple times and generating wait-time-dependent background signal values for the array of pixel sensor cells; and
[0039] generating a set of noise-compensated pixel values by subtracting a corresponding wait-time-dependent background signal value from each of the raw pixel values.
[0040] The dark pixels may be located in an array of dark pixel rows and dark pixel columns interspersed among the array of pixel sensor cells, wherein the wait-time-dependent background signal values comprises an interpolated time-dependent map spanning the array of pixel sensor cells, and wherein the corresponding wait-time-dependent background signal value is interpolated from the interpolated time-dependent map.
[0041] According to yet another aspect of the present invention, yet another method of operating an array of pixel sensor cells is provided, which comprises:
[0042] exposing an entirety of an array of pixel sensor cells, wherein each of the pixel sensor cells contains a light conversion unit and a floating drain;
[0043] simultaneously transferring electrical charges from the light conversion unit to the floating drain in each of the array of pixel sensor cells; and
[0044] sensing the electrical charges in the floating drains one row at a time and for each row in the array to generate raw pixel values for each pixel sensor cell;
[0045] measuring pixel values for dark pixels multiple times and generating wait-time-dependent background signal values for the array of pixel sensor cells;
[0046] measuring time dependence of a voltage of a floating drain of test dark pixels pre-charged at a voltage different from a reset voltage, and generating wait-time-and-voltage-dependent signal offset values from a difference between time dependence of the voltage and time dependence of the wait-time-dependent background signal values for the pixel sensor cells; and
generating a set of noise-compensated pixel values by subtracting a corresponding wait-time-dependent background signal value and a corresponding wait-time-and-voltage-dependent signal offset value from each of the raw pixel values.
[0048] In one embodiment, each of the test dark pixels comprises:
[0049] a light conversion unit and an overlying light shield blocking entry of light into the instance of the light conversion unit;
[0050] a floating diffusion; and
[0051] a contact via electrically connected to the floating diffusion for providing electrical bias and measurement of voltage of the floating diffusion.
[0052] The method may further comprise repeating measuring time dependence of a voltage of a floating drain of test dark pixels pre-charged at different pre-charge voltages, and wherein the wait-time-and-voltage-dependent signal offset values are interpolated for measured values of pre-charge voltages.
BRIEF DESCRIPTION OF THE DRAWINGS
[0053] FIG. 1 is a prior art rolling shutter image capture and read out sequence.
[0054] FIG. 2 is a prior art global shutter image capture and read out sequence.
[0055] FIG. 3 is a vertical cross-sectional view of a prior art CMOS pixel sensor cell.
[0056] FIG. 4 is a first exemplary global shutter image capture and row read out sequence employing a first exemplary temporal order of row sensing according to a first aspect of the present invention.
[0057] FIG. 5 is a second exemplary global shutter image capture and row read out sequence employing a second exemplary temporal order of row sensing according to the first aspect of the present invention.
[0058] FIG. 6 is a top-down view of a first exemplary structure for an array of pixel sensor cells according to a second aspect of the present invention.
[0059] FIG. 7 is a graph of wait-time dependent background signal values as a function of wait time between global transfer and row read according to the second aspect of the present invention.
[0060] FIG. 8 is a top-down view of a second exemplary structure for an array of pixel sensor cells according to a third aspect of the present invention.
[0061] FIG. 9 is a graph of wait-time-and-voltage-dependent background signal offset values as a function of wait time according to the third aspect of the present invention.
DETAILED DESCRIPTION OF THE INVENTION
[0062] As stated above, the present invention relates to methods for enhancing the quality of image frames from a pixel sensor array, which are now described in detail with accompanying figures. It is noted that like and corresponding elements are referred to by like names or reference numerals in the figures.
[0063] Referring to FIG. 4 , a first exemplary global shutter image capture and row read out sequence employing a first exemplary temporal order of row sensing is shown according to a first aspect of the present invention. The first exemplary global shutter image capture and row read out sequence comprises a global shutter image capture sequence and a first exemplary row read out sequence.
[0064] The global shutter image capture sequence employs a global shutter operation for an array of pixel sensor cells. Each of the pixel sensor cells in the array comprises a light conversion unit and a floating drain. The light conversion unit generates charge carriers when exposed to incident light. The floating drain stores the charge carriers after the exposure. In case the pixel sensor cell comprises a CMOS image sensor pixel, the charge transfer is effected by a transfer gate transistor. If the array of pixel sensor cells is a CMOS image sensor, a photosensitive diode may be employed as the light conversion unit.
[0065] Prior to exposure, the entire array of pixel sensor cells is reset simultaneously to remove any residual charge that may have been present in the light conversion unit. If the pixel sensor cell comprises a CMOS image sensor pixel, such a reset may be effected by turning on a reset transistor connected to a photosensitive diode, which is the light conversion unit of the CMOS image sensor pixel.
[0066] The entire array of pixel sensor cells is exposed to light simultaneously. In other words, the image for the whole frame is captured in the light conversion units of the pixel sensor cells at the exactly same time for all the rows and columns. The signal in the form of electrical charges in each light conversion unit is then simultaneously transferred to a corresponding floating diffusion within the pixel sensor cell containing the light conversion unit. The floating diffusion of the pixel sensor cells in the array holds the data for the image frame in the form of electrical charges.
[0067] In the first exemplary row read out sequence, charges stored in the floating diffusions of the arraye read out one row at a time and for each row in the array. According to the present invention, a temporal order of row sensing in the read out sequence contains a sequence of rows in which at least one pair of sequentially neighboring rows is physically non-neighboring. Therefore, the temporal order of row sensing not the same as any physical order of rows from one end of the array to another end of the array. This contrasts with prior art temporal order of row sensing in which the order of row sensing coincides with a physical order of rows from one end of the array to another end of the array, e.g., from a first row to the last row of the array. Temporal order herein denotes an order in time of rows that are sensed during the first read out sequence. Physical order herein denotes an order in a physical space of rows in the array based on physical layout, i.e., geometry in the physical arrangement of the rows of the array.
[0068] The temporal order of row sensing is characterized as an out-of-order read out for the image frame from the global shutter operation. Instead of reading the rows according to the sequence of the physical arrangement of the rows, e.g., from a physical first row to a physical last row, the rows are read in a pattern which samples rows from different portions of the entire image, e.g., a top portion, a middle portion, and a bottom portion, early in the read out sequence. The unread rows at this point are subsequently read as more rows to be sensed are selected from the remaining unsensed rows. The unread rows in the array of pixel sensor cells are reduced as more and more rows are read in time until all of the rows are read out. Preferably, the local density of read rows increases uniformly across the array and steadily in time.
[0069] The sequential pattern of sensed rows, which is determined by the temporal order may vary among embodiments. For example, a binary pattern or random pattern of row read out may be employed for the temporal order. Preferably, at any point in the read, the number of rows read out from among the entirety of rows in the array is approximately the same for every portion of the image.
[0070] Such a read out pattern according to the present invention provides many advantages. First, the average noise in any part of the image is the same. The noise is generated by a leakage current from the floating drain during the time between the transfer of charges into the floating drain and the read out of the charges from the floating drain. Since the row read out order will be evenly distributed from the top to the bottom of the array, the noise will be evenly distributed across the entirety of the image instead of a distribution in a correlated fashion from the top of the image to the bottom, which results in a localized and concentrated distribution of the noise at the bottom of the image. Such a uniform distribution of the noise makes the image appear less noisy to the human eye than a correlated distribution of the noise in a localized manner.
[0071] Second, since the location of the rows read early in the sequence is known, de-noising techniques can be used which more heavily weight rows which are read out earlier over rows which are read later in the read sequence. Such weighted correction of the noise provides an enhanced noise reduction technique, in which the raw image frame from the array of pixel sensor cells may be processed to generate a processed image frame such as a contrast enhanced image frame.
[0072] Preferably, all pairs of sequentially neighboring rows in the temporal order are physically non-neighboring in the array. In other words, a row having a k-th position in the temporal order and another row having a (k+1)-th position in the temporal order are not physically neighboring in the array of pixel sensor cells. k may be any positive integer less than the total number of rows in the array of pixel sensor cells. For example, if the row having the k-th position in the temporal order is a physical l-th row, i.e., a row located separated from a first row at the edge of the array of pixel sensor cells by exactly (l-1) other rows, the row having the (k+1)-th position in the temporal order is not a physical (l-1)-th row or a physical (l+1)-th row. l may be any positive integer less than the total number of rows in the array of pixel sensor cells. 0-th row is considered to be non-existent.
[0073] Similarly, all pairs of physically neighboring pairs of rows in the arraye sequentially non-neighboring pairs in the temporal order. A physical l-th row and a physical (l+1)-th row are physically neighboring in the array of pixel sensor cells. l may be any positive integer less than the total number of rows in the array of pixel sensor cells. The physical l-th row and the physical (l+1)-th row are not sequentially neighboring in the temporal order. For example, if the physical l-th row has a k-th position in the temporal order, the physical (l+1)-th row does not have a (k-1)-th position or a (k+1)-th position in the temporal order. k may be any positive integer less than the total number of rows in the array of pixel sensor cells. 0-th row is considered to be non-existent.
[0074] Rows having adjacent positions in the temporal order are herein referred to as sequentially contiguous rows. For example, an m-th entry of the temporal order and an (m+1)-th entry in the temporal order are sequentially contiguous rows. The m-th entry of the temporal order is herein referred to as a temporal m-th row, and the (m+1)-th entry of the temporal order is herein referred to as a temporal (m+1)-th row.
[0075] The temporal order may comprise a set of sequentially contiguous rows, wherein each row in the set belongs to a different physically contiguous block of rows located in the array and having a number of rows, which is herein referred to as a first number of rows. Each of the physically contiguous blocks of rows is bounded by a pair of rows that precede the set in the temporal order or by a row that precedes the set in the temporal order and one of an outer edge of a physical first row and a physical last row in the array.
[0076] In the first exemplary temporal order of row sensing, the total row number N represent the number of the entirety of the rows in the array of pixel sensor cells. In this example, the first row to be read out is the physical N-th row. The second row to be read out is the physical (N/ 2 )-th row. The third row to be read out is the physical (N/ 4 )-th row. The fourth row to be read out is the physical ( 3 N/ 4 )-th row. The fifth row to be read out is the physical (N/ 8 )-th row. The sixth row to be read out is the physical ( 3 N/ 8 )-th row. The seventh row to be read out is the physical ( 5 N/ 8 )-th row. The eighth row to be read out is the physical ( 7 N/ 8 )-th row. The ninth row to be read out is the physical (N/ 16 )-th row; the tenth, the physical ( 3 N/ 16 )-th row; the eleventh, the physical ( 5 N/ 16 )-th row; the twelfth, the physical ( 7 N/ 16 )-th row; the thirteenth, the physical ( 9 N/ 16 )-th row; etc.
[0077] An exemplary set of sequentially contiguous rows in the above example include the fifth row to be read out, the sixth row to be read out, the seventh row to be read out, and the eighth row to be read out. In other words, one example of the set of sequentially contiguous rows include a temporal fifth row, a temporal sixth row, a temporal seventh row, and a temporal eighth row. The temporal fifth row is the physical (N/ 8 )-th row, a temporal sixth row is the physical ( 3 N/ 8 )-th row, a temporal seventh row is the physical ( 5 N/ 8 )-th row, and a temporal eighth row is the physical ( 7 N/ 8 )-th row.
[0078] Each row in the set belongs to a different physically contiguous block of rows located in the array and having a first number of rows. In this example, the temporal fifth row belongs to a first physically contiguous block of rows including the first row through the (N/ 4 -1)-th row. The temporal sixth row belongs to a second physically contiguous block of rows including the (N/ 4 +1)-th row through the (N/ 2 -1)-th row. The temporal seventh row belongs to a third physically contiguous block of rows including the (N/ 2 +1)-th row through the ( 3 N/ 4 -1)-th row. The temporal eighth row belongs to a fourth physically contiguous block of rows including the ( 3 N/ 4 +1)-th row through the (N-1)-th row. Each of the four physically contiguous block of rows are different. The first number of rows is N/ 4 -1.
[0079] Each of the physically contiguous blocks of rows is bounded by a pair of rows that precede the set in the temporal order or by a row that precedes the set in the temporal order and one of an outer edge of a physical first row and a physical last row in the array. In this example, first physically contiguous block of rows is bounded by a pair of an outer edge of a physical first row, which is one of the physical boundaries of the array of pixel sensor cells, and the (N/ 4 )-th row, which is the temporal third row that precedes the set in the temporal order. In other words, since the (N/ 4 )-th row is the temporal third row and the set of sequentially contiguous rows includes the temporal fifth row through the temporal eighth row, the physically contiguous block of rows is bounded by a row, i.e., the temporal third row, that precedes the set of sequentially contiguous rows. The second physically contiguous block of rows is bounded by a pair rows that precede the set, and particularly by the set of the (N/ 4 )-th row, which is the temporal third row, and the (N/ 2 )-th row, which is the temporal second row. Both the temporal third row and the temporal second row precede the set of temporal fifth through eighth rows in the temporal order. Similarly, the third physically contiguous block of rows is bounded by a pair rows that precede the set, and particularly by the set of the (N/ 2 )-th row, which is the temporal second row, and the ( 3 N/ 4 )-th row, which is the temporal fourth row. Both the temporal second row and the temporal fourth row precede the set of temporal fifth through eighth rows in the temporal order. The fourth physically contiguous block of rows is bounded by a row that precedes the set in the temporal order and a physical last row in the array, which is the pair of the physical ( 3 N/ 4 )-th row, which is the temporal fourth row, and the physical N-th row, which is the temporal first row. Both the temporal fourth row and the temporal first row precede the set of temporal fifth through eighth rows in the temporal order.
[0080] Variations of the first exemplary temporal order are explicitly contemplated herein in which a discrete number of rows are changed in position in the temporal order without rendering the temporal order identical to any physical order of rows from one end of the array to another end of the array. Specifically, moving the position of the physical N-th row from the temporal first row to other temporal row positions are explicitly contemplated herein. Also, moving the position of the physical first row to a temporal first position, a temporal second position, or a temporal third position is also explicitly contemplated herein. In general, any discrete number of changes among the positions in the temporal order so that at least one pair of sequentially neighboring rows is physically non-neighboring. Preferably, the temporal order is changed without substantially affecting the uniform distribution of overall density of sensed rows across the various portions of the array so that the noise is evenly distributed across the entirety of the array.
[0081] The temporal order may comprise another set of sequentially contiguous rows that follow the set of sequentially contiguous rows. Each row in the other set belongs to another different physically contiguous block of rows located in the array and having a second number of rows. The first number is greater than twice the second number.
[0082] For example, the other set of sequentially contiguous rows may comprise the temporal ninth row through temporal sixteenth row, which corresponds to a set of the physical (N/ 16 )-th row, the physical ( 3 N/ 16 )-th row, the physical ( 5 N/ 16 )-th row, the physical ( 7 N/ 16 )-th row, the physical ( 9 N/ 16 )-th row, the physical ( 11 N/ 16 )-th row, the physical ( 13 N/ 16 )-th row, and the physical ( 15 N/ 16 )-th row.
[0083] Each of the other physically contiguous blocks of rows is bounded by a row that precedes the set and another row that is in the set in the temporal order or by a row that is in the set in the temporal order and one of the physical first row and the physical last row in the array. For example, each of the other physically contiguous blocks of rows may be bounded by a row, which may be one of the temporal first row through the temporal fourth row, that precedes the set, i.e., the set of sequentially contiguous rows including the temporal fifth row through the temporal eighth row, and another row that is in the set in the temporal order. Alternately, each of the other physically contiguous blocks of rows may be bounded by a row that is in the set in the temporal order and one of the physical first row and the physical last row in the array. Similar analysis applies to the other set of sequentially contiguous rows containing temporal ninth row through temporal sixteenth row as the set of sequentially contiguous rows containing temporal fifth row through temporal eighth row.
[0084] The order of physical rows in some sets of sequentially contiguous rows may be mathematically expressed. In an array of pixel sensor cells includes a physically contiguous subset of the array of rows including (N-1) physically adjoined rows, row numbers from 1 to (N-1) may be assigned in a monotonically increasing order to each row in the physically contiguous subset of the array in an order corresponding to an order of monotonically increasing distance from an edge row of the physically contiguous subset of the array. In this case, N= 2 n , and n is a positive integer, and the subset comprises (N-1) rows.
[0085] The temporal order for this subset may be the same as the first exemplary temporal order less the first entry, i.e., a modification of the first exemplary temporal order by removing the physical N-th row. In this case, the temporal order may be determined based on an order of row numbers sequentially generated by a formula (2×j−1)×N/2i, wherein i is an integer that varies from 1 to n by an increment of 1, and wherein j is an integer that varies from 1 to 2 (i−1) for each value of i prior to incrementing a value of the i. For example, the temporal first row of this temporal order is obtained by setting i and j equal to 1, which generates a physical (N/ 2 )-th row for the temporal first row. The temporal second row and the temporal third row of this temporal order is obtained by setting i equal to 2 and by varying j from 1 to 2, which generates a physical (N/ 4 )-th row for the temporal second row and a physical ( 3 N/ 4 )-th row for the temporal third row. The temporal fourth row through the temporal seventh row of this temporal order is obtained by setting i equal to 3 and by varying j from 1 to 4, which generates a physical (N/ 8 )-th row for the temporal fourth row, a physical ( 3 N/ 8 )-th row for the temporal fifth row, a physical ( 5 N/ 8 )-th row for the temporal sixth row, and a physical ( 7 N/ 8 )-th row for the temporal seventh row.
[0086] Referring to FIG. 5 , a second exemplary row read out sequence employing a second exemplary temporal order of row sensing is shown according to the first aspect of the present invention. In general, the temporal order of row sensing may be determined by iterative partitioning of at least one physically contiguous block of rows. A predetermined number of physically non-neighboring rows from each partition of the at least one physically contiguous blocks may be selected. The selected predetermined number of physically non-neighboring rows constitute sequentially contiguous rows in the temporal order.
[0087] In the second exemplary row read out sequence, the predetermined number is 2. In light of this view, the predetermined number is 1 for the first exemplary row read out sequence of FIG. 4 .
[0088] In general, the integer is less than half of a total count of rows in each of the at least one physically contiguous block. This is because division of an array into a number of blocks that exceeds half of the total count of rows invariably generates neighboring rows in the temporal order. Each partition of the at least one physically contiguous blocks may, or may not, have a same number of rows therein. Preferably but not necessarily, each partition of the at least one physically contiguous blocks may, or may not, have the same number of rows therein.
[0089] According to the present invention, a raw image frame may be subjected to image processing to generate a processed image frame so that noise level of the processed image frame is reduced compared to the raw image frame. The raw image frame comprises pixels having pixel values obtained by sensing of an entirety of the array of pixel sensor cells. The processed image frame is generated by image processing.
[0090] During the image processing, pixel values of pixels of the raw image frame are locally averaged with weighting to provide processed pixel values for pixels of the processed image frame. The weighting of each the local pixel value correlates with a sequential location of a row to which each the local pixel belong in the temporal order of row sensing. Specifically, the earlier the sensing for a given pixel, the higher weighting is given to the pixel values of pixels of the raw image frame when other factors are the same such as the distance between the pixel, i.e. the target pixel, for which the processed pixel value is calculated and the local pixel that provides a compensatory adjustment to the pixel value for the target pixel.
[0091] For example, the weighting may comprise a distance dependent component and a sensing-order dependent component. The distance dependent component is the same for a pair of pixels equal distance apart from a pixel for which processed pixel values are determined and belonging to different rows. The sensing-order component is greater for a pixel among the pair of pixels that belong to a row that is sensed earlier. More weight to an early read pixel relative to a later read pixel reduces overall noise in the processed image frame. Thus, the information from the temporal order is applied to enhance dynamic range and reduce noise in the processed image frame.
[0092] Referring to FIG. 6 , a top-down view of a first exemplary structure is shown, which includes a semiconductor device including an array of pixel sensor cells according to a second aspect of the present invention. The first exemplary structure comprises an array of pixel sensor cells, dark pixel rows containing dark pixels, and dark pixel columns containing additional dark pixels. Each pixel sensor cell comprises a light conversion unit and a floating drain. For example, the light conversion unit may be a photosensitive diode and the pixel sensor cells may be complementary metal oxide semiconductor (CMOS) image sensor cells.
[0093] Dark pixels are formed at the edged of the array of pixel sensor cells. Each of the dark pixels comprises an instance of the light conversion unit and an overlying light shield blocking entry of light into the instance of the light conversion unit. The signal generated from a measurement on the dark pixel immediately after the charge transfer provides a “dark floor” which is an estimation of a voltage output from a pixel sensor cell that is not illuminated by any incident light during the simultaneous global exposure of the array of pixel sensor cells. The measured value of the dark floor is used to calibrate the output of the image signal from the array of pixel sensor cells.
[0094] The dark pixel rows are labeled DR 1 , DR 2 , . . . , DR(u- 1 ), DR(u), DR(u+ 1 ), DR(u+ 2 ), . . . , DR(p- 1 ), and DRp, i.e., the first exemplary structure comprises p number of dark pixel rows. The dark pixel rows may be grouped into top dark rows and bottom dark rows. The top dark rows include the dark pixel rows labeled DR 1 , DR 2 , . . . , DR(u- 1 ), DR(u) located in the top portion the first exemplary structure, of which the total count is an integer u. The bottom dark rows include the dark pixel rows labeled DR(u+ 1 ), DR(u+ 2 ), . . . , DR(p- 1 ), DR(p) located in the bottom portion the first exemplary structure, of which the total count is an integer p-u. The dark pixel columns are labeled DC 1 , DC 2 , . . . DC(v- 1 ), DC(v), DC(v+ 1 ), DC(v+ 2 ), . . . , DC(q- 1 ), and DCq, i.e., the first exemplary structure comprises q number of dark pixel columns. The dark pixel columns may be grouped into left dark columns and right dark columns. The left dark columns include the dark pixel columns labeled DC 1 , DC 2 , . . . , DC(v- 1 ), DC(v) located in the left portion the first exemplary structure, of which the total count is an integer v. The right dark columns include the dark pixel columns labeled DC(v+ 1 ), DC(v+ 2 ), . . . , DC(q- 1 ), DC(q) located in the right portion the first exemplary structure, of which the total count is an integer q-v. The number p is typically between 10 and 100 for an array having more than 500 rows. The number q is typically between 10 and 100 for an array having more than 500 columns. In a variation of the first exemplary structure, the dark pixel columns may be omitted. In another variation of the first exemplary structure, the dark pixel rows may be omitted.
[0095] While FIG. 6 corresponds to a case in which all dark pixel rows are classified into top dark rows and bottom dark rows, embodiments are contemplated herein in which a center row not belonging to the top dark rows or bottom dark rows is present. Further, embodiments that the dark rows are classified into more than two groups are explicitly contemplated herein. Further, while FIG. 6 corresponds to a case in which all dark pixel columns are classified into left dark columns and right dark columns, embodiments are contemplated herein in which a center column not belonging to the left dark columns or right dark columns is present. Further, embodiments that the dark columns are classified into more than two groups are explicitly contemplated herein.
[0096] Some of the dark pixels are located in the dark pixel rows are at the top and or the bottom of the array of pixel sensor cells. Some other dark pixels are located in the dark pixel columns that are at the left and or the right of the array of pixel sensor cells. In general, the dark pixels are located in an array, which is a dark pixel array, of dark pixel rows and dark pixel columns located at the edges of the array of pixel sensor cells. Although it is shown in FIG. 6 , there is no requirement for the dark columns to be on both sides of the array. Many imager designs contain dark columns on one side of the array only. Similarly, many imager designs contain dark rows only at the top or only at the bottom of the array. If dark rows are physically present on both sides of the array, there is no requirement that the number of dark rows be the same on both sides. Similarly, there is no requirement that the number of dark columns be the same on the top and the bottom. The physical location of the dark rows and columns is not of importance for the operation of this invention.
[0097] During operation, an entirety of the array of pixel sensor cells is exposed to incident light. Each of the pixel sensor cells contains a light conversion unit and a floating drain as described above. Each light conversion unit generates electrical charges. The electrical charges are then simultaneously transferred from the light conversion unit to the floating drain in each of the array of pixel sensor cells. The electrical charges in the floating drains are sensed one row at a time and for each row in the array to generate raw pixel values for each pixel sensor cell.
[0098] Employing the dark pixel rows and/or dark pixel columns, pixel values for dark pixels are measured throughout the sensing operation of the array of image sensor pixels. The dark pixels in dark columns are measured along with the row in which the pixels are located. Thus, the temporal order or row read described previously will also determine the times in which the pixels in the dark columns are read. The dark rows can be read at any point during the array read. Preferably, the read out of the dark rows will be dispersed in time through out the read of the array. Each measurement on the pixel values for the dark pixels generates a background signal value corresponding to the wait time of the measurement, which is the time interval between the charge transfer and the measurement. The collection of the background signal values as a function of wait time is compiled to generate wait-time-dependent background signal values for the pixel sensor cells.
[0099] The wait-time-dependent background signal values for the pixel sensor cells are advantageously employed to provide subtraction of a time dependent background signal from the raw pixel values of the pixel sensor cells. The wait-time-dependent background signal values are dependent on the row read wait time, unlike the dark floor value, which is the measurement of the background immediately after the charge transfer into the floating drains and which is a row read delay time independent quantity.
[0100] Specifically, a set of noise-compensated pixel values are generated by subtracting a corresponding wait-time-dependent background signal value from each of the raw pixel values. By performing a subtraction on all the data for raw pixel values in the array, a noise-compensated image frame is generated from the set of noise-compensated pixel values. The noise compensation reflects the physical environment in which the array of the pixel sensor cells is placed, such as ambient temperature, as well as time dependence of the cumulative effects of leakage currents from the floating drains.
[0101] Referring to FIG. 7 , an exemplary graph of wait-time-dependent background signal values as a function of row read wait time is shown. To generate such a graph, the measuring pixel values for dark pixels are fitted with an analytical function of wait time, which is the time period between the simultaneous transferring of electrical charges and the sensing of the electrical charges. The wait-time-dependent background signal values may be generated as a map encompassing the array of the pixel sensor cells. In this case, the wait-time-dependent background signal values comprise an interpolated time-dependent map spanning the array of pixel sensor cells. The corresponding wait-time-dependent background signal value is interpolated from the interpolated time-dependent map for the purposes of calculating noise-compensated pixel values.
[0102] Referring to FIG. 8 , a second exemplary structure for an array of pixel sensor cells is shown, which includes a semiconductor device including an array of pixel sensor cells according to the third aspect of the present invention. The second exemplary structure comprises an array of pixel sensor cells, dark pixel rows containing dark pixels, and dark pixel columns containing additional dark pixels, each of which provides the same functionality as in the first exemplary structure of FIG. 6 . In addition, the second exemplary structure comprises test dark pixels, which may be incorporated into one or more test dark rows TDR and/or a test dark columns TDC.
[0103] Each of the test dark pixels comprises an instance of the light conversion unit, an overlying light shield blocking entry of light into the instance of the light conversion unit, an instance of floating diffusion, and a contact via electrically connected to the photo diode for providing an external electrical bias which can be transferred to the floating diffusion. Thus, each floating drain of the test dark pixels may be electrically biased at a predetermined voltage to pre-charge the floating drain. After setting the pre-charging of the floating drain of the test dark pixels, the change in the voltage of the floating drain may be measured over a time scale that is needed for readout of the array of the pixel sensor cells.
[0104] The array of the pixel sensor cells of the second exemplary structure may be operated in the same manner as the array of the pixel sensor cells of the first exemplary structure. Specifically, the entirety of the array of pixel sensor cells is exposed to incident light. The electrical charges are then simultaneously transferred from the light conversion unit to the floating drain in each of the array of pixel sensor cells. The electrical charges in the floating drains are sensed one row at a time and for each row in the array to generate raw pixel values for each pixel sensor cell. The wait-time-dependent background signal values are measured and advantageously employed to provide subtraction of a time dependent background signal from the raw pixel values of the pixel sensor cells as in the operation of the first exemplary structure.
[0105] In addition to the noise compensation employed for the first exemplary structure, additional noise compensation is performed according to the third aspect of the present invention. Particularly, time dependence of the voltage of a floating drain of test dark pixels that are pre-charged at a voltage different from a reset voltage is measured. The wait-time-dependent background signal value measurements are now performed as a function of the bias at the transfer time.
[0106] For pixels which have no illumination, there will be no charge in the photo diode and the voltage on the floating diffusion after the charge transfer will be the reset voltage (the same voltage as before the transfer. As illumination increases, the charge in the photo diode increases. This charge is transferred to the floating diffusion lowering its potential. Thus the voltage on the floating diffusion right after the global transfer is a function of the illumination level. Charge may then leak away from the floating diffusion, typically to the substrate. The rate at which charge leaks may be dependent upon the starting voltage. Employing dark pixels to calibrate the wait-time-dependent background signal value accurately simulates pixels which shave little or no illumination. Employing test dark pixels with a forced bias can accurately simulate the row read wait-time leakage dependence of pixels which have varying amounts of illumination.
[0107] In general, the time dependence of the voltage of the floating drain can be dependent upon the starting voltage of the floating drain. The measurement of time dependence of voltage of a floating drain of test dark pixels may be repeated at different pre-charge voltages. Since the results of the measurement of time dependence of voltage of a pre-charged floating drain depends on the pre-charge voltage, the measured value from this measurement is herein referred to as wait-time-and-voltage-dependent background signal offset value. In other words, the background signal is offset by an amount that depends on the wait time and the pre-charge voltage, or the voltage employed to pre-charge the floating drain. Wait-time-and-voltage-dependent signal offset values are generated from the difference between time dependence of the voltage at a pre-charged floating drain, i.e., the time dependent change from the pre-charge voltage, and the time dependence of the wait-time-dependent background signal values, i.e., the time dependent change from the reset voltage of the floating drain, for the pixel sensor cells for each pre-charge voltage. The wait-time-and-voltage-dependent signal offset values may be interpolated between measured values of pre-charge voltages for any arbitrary initial voltage at the floating drain.
[0108] Referring to FIG. 9 , an exemplary graph of wait-time-and-voltage-dependent background signal offset values as a function of wait time is shown. If the floating drain is set at the reset voltage, i.e., if no charge is transferred into the floating drain, the “pre-charge” voltage is equal to the reset voltage, which is typically close to Vdd. The curve for this case, labeled “at V R ” and corresponding to the case of the pre-charge voltage being the same as the reset voltage.
[0109] As the pre-charge voltage deviates from the reset voltage, the wait-time-and-voltage-dependent background signal offset values as a function of wait time can change. The exemplary graph of FIG. 9 shows three curves corresponding to V 1 , V 2 , and V 3 .
[0110] From the wait-time-and-voltage dependence of the signal offset values, an initial voltage for any pixel sensor cell if the wait time and the voltage at the time of the read out are given. Thus, the combination of the wait-time-dependent background signal values and wait-time-and-voltage-dependent signal offset values enable reconstruction of the voltage at each pixel sensor cell once the voltage measurement at the time of the readout and the wait time for that row are known. A set of noise-compensated pixel values may be generated by subtracting a corresponding wait-time-dependent background signal value and a corresponding wait-time-and-voltage-dependent signal offset value from each of the raw pixel values. The noise-compensated pixel values reflect the estimated amount of charge in each pixel sensor cell after accounting for the impact of the circuit ambient, e.g., temperature, any inherent offsets of the array of pixel sensor cells due to variations during manufacture of the array, the differences in wait time between the charge transfer into the floating drain and the read out time for each row, and any voltage and time dependent offset due to the presence of charge in the floating region compared with the state of a charge-free floating drain. Such noise-compensation scheme generates high-fidelity wide dynamic range image frames from the array of pixel sensor cells.
[0111] While the invention has been described in terms of specific embodiments, it is evident in view of the foregoing description that numerous alternatives, modifications and variations will be apparent to those skilled in the art. Accordingly, the invention is intended to encompass all such alternatives, modifications and variations which fall within the scope and spirit of the invention and the following claims. | The image qualify of an image frame from a CMOS image sensor array operated in global shutter mode may be enhanced by dispersing or randomizing the noise introduced by leakage currents from floating drains among the rows of the image frame. Further, the image quality may be improved by accounting for time dependent changes in the output of dark pixels in dark pixel rows or dark pixel columns. In addition, voltage and time dependent changes in the output of dark pixels may also be measured to provide an accurate estimate of the noise introduced to the charge held in the floating drains. Such methods may be employed individually or in combination to improve the quality of the image. | 7 |
FIELD OF THE INVENTION
This invention relates to electroluminescent devices, and specifically to an electroluminescent device which includes a rare earth-doped silicon-rich layer as the light emitting element.
BACKGROUND OF THE INVENTION
The replacement of traditional copper interconnects in integrated circuitry with optical data transfer mechanisms solves problems associated with signal integrity, communication speed and chip reliability, however, a reliable and suitable light source, which may be fabricated on silicon substrates and which is compatible with CMOS processing has not been available. A class of materials, e.g., rare earth-doped oxides, has been shown to be capable of emitting light when electrically excited. Different rare earth elements emit light of different wavelengths. The fabrication of such known devices has been performed by ion implantation and high temperature annealing processes, however, this technique lacks control over the depth and the dose of the rare earth ion implant, and does not have the ability to heal any damage induced by the requisite high-temperature treatment.
For rare earth-doped silicon-rich oxide (SRO) electroluminescent (EL) devices, high power electric fields must be applied during the injection of hot electrons into rare earth doped SROs, and high currents are required in order to generate sufficient quantities of electroluminescent photons. Therefore, high quality rare earth doped SROs must be deposited, and the process integration induced damage must be repaired.
Castagna et al., High efficiency light emission devices in silicon , Mat. Res. Soc. Symp, Vol. 770, (2003) demonstrated a working electroluminescent (EL) device using silicon-rich silicon oxide as the light emitting material. Silicon nano particle based-EL devices have been a focus of research because of compatibility with existing silicon-based IC industry processes. Undoped silicon nano particles produce a broad light spectrum because of wide particle size distribution, in a range of between about 1 nm to 10 nm. Rare earth doped SROs emit light at discrete wavelengths, corresponding to the intra 4 f transitions of the rare earth atoms. For example, the main emission wavelengths for terbium, ytterbium, and erbium doped SROs are located at wavelengths of 550 nm, 983 nm, and 1540 nm, respectively. The relative monochromaticity of the rare earth based light emission provides much better control of the wavelength and may have many applications in optical communications. To fabricate doped SROs, rare earth ion implantation is normally used, Castagna et al., supra, and Sun et al., Bright green electroluminescence from Tb 3+ in silicon metal - oxide - semiconductor devices , J. Applied Physics 97 (2005). Although ion implantation provides purity and flexibility, it is expensive and limited by implantation dose. Dopant concentration vs depth is not uniform, and abrupt dopant concentration changes are not possible.
For rare earth doped nano-SRO EL devices, high power fields must be used for injection of hot electrons into the rare earth doped SRO, which generates the electroluminescence, hence, high quality rare earth doped SRO films have to be deposited, and the process integration induced damage must be removed.
Some of us have previously disclosed A method to make silicon nanoparticle from silicon rich oxide by DC reactive sputtering for electroluminescence application, Gao et al., U.S. patent application Ser. No. 11/049,594, filed Feb. 1, 2005, now abandoned.
SUMMARY OF THE INVENTION
An electroluminescent device includes a substrate having a well formed therein and a gate oxide layer formed thereon; a rare earth-doped silicon-rich layer formed on the gate oxide layer for emitting a light of a pre-determined wavelength; a top electrode formed on the rare earth-doped silicon-rich layer; and associated CMOS IC structures fabricated thereabout.
A method of fabricating an electroluminescent device includes preparing a substrate; forming a gate oxide layer on the substrate; depositing a rare earth-doped silicon-rich layer on the gate oxide layer as a light emitting layer; depositing a control oxide layer on the rare earth-doped silicon-rich layer; depositing a top electrode on the control oxide layer; patterning and etching the top electrode, the control oxide layer, the rare earth-doped silicon-rich layer, and the gate oxide layer; annealing and oxidizing the structure to repair any damage caused to the rare earth-doped silicon-rich layer; and incorporating the electroluminescent device into a CMOS IC.
It is an object of the invention to produce an electroluminescent device which emits in a specific wavelength.
Another object of the device is to provide a method of fabricating a rare earth doped SRO EL.
This summary and objectives of the invention are provided to enable quick comprehension of the nature of the invention. A more thorough understanding of the invention may be obtained by reference to the following detailed description of the preferred embodiment of the invention in connection with the drawings.
BRIEF DESCRIPTION OF THE DRAWINGS
FIG. 1 is a block diagram of the method of the invention.
FIGS. 2-5 depict steps in the fabrication of a device according to the method of the invention.
FIG. 6 depicts the EDX spectrum of a terbium-doped SRO sample.
FIG. 7 depicts the refractive index of terbium-doped SRO samples before and after thermal annealing, dry and wet oxidation processes.
FIG. 8 depicts the PL intensity of terbium-doped SRO samples before and after thermal annealing, dry and wet oxidation processes.
FIG. 9 depicts a normalized PL intensity of terbium-doped SRO thin films with various thermal annealing processes.
FIG. 10 depicts the break electric field of terbium-doped SRO devices with DC-plasma power of 300 W and various oxidations.
FIGS. 11 and 12 are photographs of light emitting of terbium-doped EL devices.
FIG. 13 depicts the light emission spectrum of terbium-doped SRO at several voltages.
DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS
This invention provides deposition and integration processes for fabrication of rare earth doped silicon-rich (SR) electroluminescent (EL) devices, including a DC-sputtering deposition method to deposit rare earth-doped silicon oxides, rare earth-doped silicon nitrides and silicon-rich oxides, post-annealing, dry and wet oxidation to improve the film qualities, and proper thermal annealing process to recover the process induced degradation after fabrication. An alternative, low cost method of fabrication, which easily may be tailored to form any thickness of rare earth doped silicon-rich oxide is provided.
For implanted oxides, very thin films are difficult, if not impossible to form, using conventional methods. This invention discloses a method by which a high quality rare earth-doped silicon-rich layer is formed, incorporating the rare earth-doped SR layer into an IC, and describes characteristics of the emitted light. The quality of the deposited film is a key factor because the film must tolerate high power fields and injection of electrons at high current densities without device degradation. A detailed fabrication process according to the method of the invention is shown in FIG. 1 , generally at 10 .
The method of the invention begins with preparation of a substrate, 12 , including well formation, threshold voltage adjustment and gate oxidation to from a gate oxide layer, which is taken from the group of oxides and insulators including SiO 2 , HfO 2 , ZrO 2 , Al 2 O 3 , La 2 O 3 and Si 3 N 4 . Another gate layer may be formed on the gate oxide layer in order to make a tunneling channel layer more functional. This is accomplished by forming multiple layers of different oxides/insulators. The gate layer may be formed of any of SiO 2 , HfO 2 , ZrO 2 , Al 2 O 3 , La 2 O 3 and Si 3 N 4 , so long as the selected material is different than the material used as the gate oxide layer. A rare earth-doped SR film is deposited, 14 , using DC-sputtering. The rare earth-doped SR film may be a rare earth-doped SR silicon oxide film, or a rare earth-doped SR silicon nitride film. In the example provided herein, terbium is selected as the rare earth element, although the method of the invention will work with other selected rare earth elements, and the SR film is a silicon rich silicon oxide (SRO). This is followed by an annealing step, 16 , and an oxidation process, 18 .
A layer of control oxide is deposited 20 , and a top electrode of indium-tin-oxide (ITO) is deposited, 22 . The control oxide is used to control electron injection from the silicon substrate to the tunneling gate oxide and into the terbium-doped SR layer(s) and to avoid electron injection from the top electrode into the terbium-doped SR layers. Thus, the thickness of the control oxide layer should be at least 1.5 times, or more, thicker than the gate oxide layer, which also includes any additional gate layers. The gate is patterned and etched, 24 , stopping at the level of the gate oxide. Another annealing process 26 , referred to herein as the repair or recover annealing step, is performed to repair any damage to the structure which may have occurred during the fabrication steps to this point in the method of the invention. The device is now incorporated into an integrated circuit, 28 , to complete the CMOS structure. Generally, a rare earth-doped SRO film emits light at a wavelength of between about 400 nm to 1600 nm. The rare earth-doped SRO film has a thickness of between about 40 nm to 150 nm. The EL intensity increases with an increase in rare earth-doped SRO film thickness, however, the operating voltage of the resultant device also increases with rare earth-doped SRO film thickness, thus, a rare earth-doped SRO film thickness of between about 40 nm to 150 nm is considered to be an optimum value.
Referring now to FIG. 2 , a wafer is prepared for use as the device substrate 30 . Gate oxide 32 is formed, and may be covered with additional gate material 34 . As previously noted, a single layer of gate oxide may suffice, however, plural layers of gate oxide an additional, different gate material may be provided to facilitate the function of the tunnelling layer.
FIG. 3 depicts the structure after deposition of a layer of rare earth-doped SR 36. In the preferred embodiment of the invention, terbium is used as the rare earth to produce a predetermined, desired wavelength of emitted light from the EL device, which is about 550 run, and the SR layer is SRO. FIG. 4 depicts the structure after deposition of a layer 38 of a control oxide, which is deposited to control electron injection, and formation of a top electrode 40 of ITO. FIG. 5 shows the EL device after patterning and etching to the gate stack. As shown in the drawings and as described in this Specification, the description includes all steps of the best mode of practicing the invention. There are no additional steps, and the various layers, as described, are formed and/or deposited in sequence without any intervening steps or layers.
An n-type or p-type silicon wafer may be used as substrate 30 . After treatment in an HF 20:1 dip etching, with or without growing of a gate oxide, terbium-doped SRO films having refractive index values ranging from 1.46 to 2.5 are deposited by DC-sputtering methods, as shown in Table 1, which depicts DC sputtering process parameters and properties of terbium doped SRO films.
TABLE 1
Deposition
Thickness
Refractive
Wafer #
Power (W)
Ambient
Time (min)
(Å)
Index
1865
125
15% O 2
30
102
1.58
1483
150
15% O 2
25
104
1.56
1775
300
15% O 2
12
80.5
2.07
In order to improve the film quality of the SRO films, oxidation processes are performed. In order to determine optimum process parameters for the EL device fabricated according to the method of the invention, the deposited terbium-doped SRO film had a refractive index of 1.56 or 2.07, controlled by the DC-sputtering deposition power. For each terbium-doped SRO deposition at a given power, a variety of different anneals or oxidations were performed, as follows, where “AET” and “MRL” are designations for annealing furnace equipment.
1. Annealed in AET, at 900° C. in argon for 10 min. 2. Annealed in AET, at 1000° C. in argon for 10 min. 3. Annealed in MRL dry oxygen at 950° C. for 80 min. 4. Annealed in MRL dry oxygen at 1050° C. for 20 min. 5. Annealed in MRL wet oxygen at 900° C. for 4 min. 6. Annealed in MRL wet oxygen at 950° C. for 4 min. 7. Annealed in MRL wet oxygen at 1000° C. for 4 min,
The EDX of these samples were measured. FIG. 6 shows the typical EDX spectrum of terbium-doped SRO samples, which confirmed that terbium-doped SRO films were deposited. The terbium peak intensity is almost unchanged with different post-annealing processes.
In order to improve the film quality of terbium-doped SRO thin films, thermal anneal, dry and wet oxidation processes were investigated for the terbium-doped SRO thin films. FIG. 7 shows the refractive index of terbium-doped SRO samples before (1) and after anneal or oxidation process (2-8). For low silicon richness, ie., lower refractive index, samples deposited at plasma power of 125 W and 150 W, after dry and wet oxidation the refractive index drops to around 1.46, which is close to stoichiometric SiO 2 . For higher silicon richness samples deposited at 300 W, after dry and wet oxidation the refractive index decreases but not to the stoichiometric value. With higher temperatures and/or longer times using wet oxidation, the refractive index decreases close to 1.46, but it is still silicon rich oxide. For any further oxidation, the refractive index of the higher silicon richness samples deposited at 300 W will drop to 1.46, and the silicon substrate may also be oxidized, which allows for a higher operating voltage.
FIG. 8 shows the 266 nm excited photoluminescence (PL) intensity of terbium-doped SRO samples before and after anneal, and before and after oxidation processes. With increased DC sputtering power, the PL intensity increases and reaches maximum values at a DC plasma power of 150 W, then decreases with further increasing DC plasma power. After MPL wet oxidation at 1000° C. for 4 minutes, and dry oxidation at 950° C. for 80 minutes, the refractive index of terbium-doped SRO samples deposited at 125 W, 150 W and 300 W is close to 1.46, as shown in FIG. 7 , which is almost stoichiometric SiO 2 . The highest PL intensity of terbium-doped SRO thin films is obtained from a DC sputter power of 150 W and annealed after dry oxidation at 950° C. for 80 minutes or wet oxidation at 950° C. for 4 minutes.
Another very important issue is integration process induced damage. A plasma oxidation process, used for photoresist stripping, top electrode etching, or any plasma process for that matter, induces degradation of the PL intensity of these terbium-doped SRO films. The PL signal levels can be recovered by using a proper thermal annealing process. FIG. 9 shows the normalized PL intensity of terbium-doped SRO thin films with various thermal annealing processes. The original PL intensity of an as-deposited terbium-doped SRO is shown at ( 1 ). Using a photoresist strip process ( 2 ), the PL intensity drops to 20% of original intensity. After a forming gas anneal at 410° C. for 30 minutes ( 3 ), the PL intensity partially recovers to about 53% of the original intensity. After a rapid thermal anneal (in AET) in argon at 400° C. ( 4 ) or 500° C. ( 5 ) for 30 minutes, the PL intensity recovers to around 60% of the original intensity. After a furnace oxidation (MRL) in dry oxygen at 900° C. for 10 minutes ( 6 ), the PL intensity recovers to around 91% of the original intensity. The most effective anneal process is RPT (AET) 900° C. in argon ( 7 ) or nitrogen ( 8 ) for 3 minutes where the PL intensity can be improved to be better than the initial intensity.
FIG. 10 depicts the best IV results of terbium-doped SRO devices fabricated using a DC-plasma power of 300 W, and various oxidation parameters. The terbium-doped SRO EL device with wet oxidation shows the highest break electric field around 10 MV/cm.
FIGS. 11 and 12 show the light emitting of terbium-doped EL devices. FIG. 11 shows the photograph of probe contact the top electrode of the terbium-doped EL device with device size 100 um×100 um. FIG. 12 shows the light emitting of the terbium-doped SRO EL device. FIG. 13 shows the spectrum of terbium-doped SRO EL device. The spectrum shows the typical terbium EL peaks, which confirms that the emitted light is generated by a terbium-doped SRO EL device.
In summary, terbium-doped SRO EL devices with structure of n-silicon/thermal oxide/terbium-doped SRO/thermal oxide/ITO have been made. The terbium concentration is estimated to be 2% for terbium/(Tb+Si) in the demonstrated device but can be up to 10%. The integration processes including DC-sputter deposition, wet oxidation and recovering anneal processes are critical steps for the successful fabrication of terbium-doped SRO EL devices.
In order to improve the film quality and reduce the process induced damage of the terbium-doped SRO films, the deposited silicon richness is optimized, thermal annealing and oxidation processes are provided at optimal process parameters to improve the film quality of terbium-doped SRO thin films, The highest PL intensity of terbium-doped SRO thin films is obtained from DC sputtering power of 150 W, and dry oxidation at 950° C. for between about 80 minutes to 160 minutes or wet oxidation at 950° C. for about four minutes. The integration process induced damage can be also recovered by a proper thermal anneal process. The best thermal annealing processes are a RTP (AET) at 900° C. in argon or nitrogen for about three minutes. The best EL properties are obtained from terbium-doped SRO EL devices with DC-plasma power of 300 W, thickness of around 100 nm, wet oxidation at 950° C. for about four minutes and recovering annealing at AET 900° C. in nitrogen for about three minutes, which are considered critical values because of the less than desirable performance of devices fabricated using other than these precise parameters.
Thus, a method to fabricate a terbium-doped SRO EL and a devices fabricated by the method of the invention has been disclosed. It will be appreciated that further variations and modifications thereof may be made within the scope of the invention as defined in the appended claims. | A method of fabricating an electroluminescent device includes, on a prepared substrate, depositing a rare earth-doped silicon-rich layer on gate oxide layer as a light emitting layer; and annealing and oxidizing the structure to repair any damage caused to the rare earth-doped silicon-rich layer; and incorporating the electroluminescent device into a CMOS IC. An electroluminescent device fabricated according to the method of the invention includes a substrate, a rare earth-doped silicon-rich layer formed on the gate oxide layer for emitting a light of a pre-determined wavelength; a top electrode formed on the rare earth-doped silicon-rich layer; and associated CMOS IC structures fabricated thereabout. | 7 |
[0001] This application claims the benefit of U.S. Provisional Application No. 61/675,511, entitled “Energy Efficient Carrier Aggregation for LTE-Adv Systems,” filed on Jul. 25, 2012, the contents of which are incorporated herein by reference.
BACKGROUND OF THE INVENTION
[0002] The present invention relates to carrier aggregation and, more particularly, to secondary component carrier allocation.
[0003] Carrier aggregation (CA) is an important feature of LTE-advanced that allows its users to aggregate upto 100 MHz of (dis-)contiguous spectral chunks to provide increased data rates. While the conventional approach of allowing LTE-adv users to be configured on all component carriers, results in maximum diversity gain for scheduling, it also increases the users' power consumption and processing that scale with the number of component carriers. We argue that it is possible to operate the LTE-adv users on a small subset of component carriers to reduce their energy consumption, without any appreciable loss to the scheduling gain. A step in realizing this goal however, is to address the joint problem of component carrier selection as well as scheduling.
[0004] We highlight the hardness of the joint problem when the number of component carriers that can be activated for a LTE-adv user is limited. Towards solving the problem, we consider various models that incorporate contiguous/discontiguous CA as well as backlogged/finite buffers and propose efficient, greedy algorithms with performance guarantees that are also simple to implement. Our evaluations based on LTE simulation parameters, reveal that our algorithms help realize 80-90% of the maximum scheduling gain with just half the component carriers and provide 15-25% throughput gain over conventional load and signal power (RSRP) based carrier selection schemes.
[0005] The conventional approach of allowing LTE-adv users to be configured on all component carriers, results in maximum diversity gain for scheduling. However, it also increases the users' power consumption and processing that scale with the number of component carriers.
[0006] The proliferation of mobile devices and the exponential growth of mobile data traffic has increased the demand for higher data rates from next generation cellular networks like LTE-advanced, WiMAX, etc. In addition to OFDMA being employed as the air interface in all these technologies, several other features such as small cells, carrier aggregation, etc. are being considered. While small cells increase the area spectral efficiency and are a key to increasing the system capacity, several challenges remain in realizing them in practice. On the other hand, carrier aggregation provides an immediate, effective solution for network operators to repurpose spectrum from older technologies 2/3G to 4G) and aggregate fragmented spectral allocations to deliver higher data rates.
[0007] Carrier aggregation (CA) can be of multiple types as shown in FIG. 1( a ). Component carriers (CC, spectral chunks) can be aggregated dis-contiguously either within a band (intra-band) or across bands (inter-band), but contiguously only within a band (intra-band). While CA is supported only by LTE adv users, LTE-adv (release 10 onwards) itself allows for backward compatibility with release 8/9 users that operate on only one CC. For every user, a CC is configured to be the primary CC (PCC) that is responsible for key operations such as location registration, RRC (re-)establishment, etc. and hence cannot be changed dynamically. On the other hand, the additional CCs (secondary CCs) in CA can be (de)activated dynamically for LTE-adv users.
[0008] In the conventional approach, where LTE-adv users are configured with all available CCs, the selection of CCs is restricted to the choice of PCC for each user, with the remaining CCs serving as SCCs. Due to the nature of operations on PCC, its selection is decoupled from scheduling and determined semi-statically based on load-balancing or reference signal received power (RSRP). While activating LTE-adv users on all CCs provides maximum diversity gain through scheduling, it also increases the energy consumption and processing at the user (device)—factors that scale with the number of CCs activated. Hence, we posit the following question: Is it possible to operate the LTE-adv users on a small subset of component carriers to reduce their energy consumption, without any appreciable loss to the scheduling gain? Given the plethora of network interfaces and applications being housed by smart mobile devices and their consequent impact on battery drainage, understanding the answer to the above question is both important and timely.
[0009] We answer in the affirmative and argue that it is indeed possible to operate the LTE-adv users on a small subset of CCs without an appreciable loss to scheduling performance. Note that selection of secondary CCs (SCCs) for LTE adv users now becomes an integral component and directly impacts scheduling performance. Given that SCCs can be (de)activated dynamically, a key to keeping the loss in performance small, is to integrate and couple CC selection with scheduling and address them jointly for LTE-adv users. Towards addressing this goal and hence seeking an answer to our motivating question, we make the following contributions:
We prove the hardness of the coupled problem of CC selection and scheduling when the number of CCs that can be activated for a LTE-adv user is limited. Towards solving the problem, we consider various models that incorporate contiguous(C)/dis-contiguous(D) CA as well as backlogged(B)/finite(F) user buffers and propose efficient, greedy algorithms with performance guarantees that are also simple to implement. Specifically, our algorithms yield approximation guarantees of ½, ¼, ½, and ⅓ for the models DB, DF, CB and CF respectively. Our evaluations based on LTE simulation parameters, reveal that our algorithms help realize 80-90% of the maximum scheduling gain with just half the component carriers and provide 15-25% throughput gain over conventional load-based and RSRP-based carrier selection schemes.
[0013] Our results are promising and indicate that with the help of efficiently designed joint CC selection and scheduling algorithms for LTE-adv users, it is possible to realize close-to the full performance benefits of CA (achieved with all CCs), while expending only a fraction of the user energy.
[0014] Existing solutions [1, 2, 3] restrict the number of component carriers for a user by load balancing users on different component carriers (CCs). However, since the allocation of specific CCs to users is done independent of scheduling, it comes at the expense of diversity gain and throughput performance.
REFERENCES
[0000]
[1] R. Ratasuk, a Tom, and A. Ghosh, “Carrier aggregation in lte advanced,” in IEEE VTC, May 2010.
[2] L. Garcia, K. Pedersen, and P. Mogensen, “Autonomous component carrier selection: interference management in local area environments for lte-advanced,” in IEEE Communications Magazine, September 2009.
[3] A. Li, K. Takeda, N. Miki, Yan, and H. Kayama, “Search space design for cross-carrier scheduling in carrier aggregation of lte-advanced system,” in IEEE ICC, June 2011.
BRIEF SUMMARY OF THE INVENTION
[0018] An objective of the present invention is to aim to jointly performed CC selection for users along with their resource scheduling. This helps determine the limited but appropriate set of CCs for each user. While energy consumption is lowered due to the reduced use of CCs, diversity gain and hence throughput performance is also not very sacrificed in the process.
[0019] An aspect of the present invention includes a method implemented in a mobile communications system. The method comprises selecting primary component carrier c p for a new user according to formula
[0000]
c
p
=
arg
max
c
r
avg
,
c
l
c
,
[0000] where r k,c avg is reference signal received power (RSRP) averaged over a spectrum for user k on component carrier c, and performing joint secondary CC selection for one or more Long Term Evolution (LTE)-Advanced users and resource scheduling for one or more LTE users and said one or more LTE-Advanced users.
[0020] Another aspect of the present invention includes a mobile communications system. The mobile communications system comprises a first selection unit to select primary component carrier c p for a new user according to formula
[0000]
c
p
=
arg
max
c
r
avg
,
c
l
c
,
[0000] where is r k,c avg is reference signal received power (RSRP) averaged over a spectrum for user k on component carrier c, and a performance unit to perform joint secondary CC selection for one or more Long Term Evolution (LTE)-Advanced users and resource scheduling for one or more LTE users and said one or more LTE-Advanced users.
BRIEF DESCRIPTION OF THE DRAWINGS
[0021] FIG. 1 depicts (a) types of CA and (b) discontiguous CA with 10 LTE-adv users.
[0022] FIG. 2 depicts performance of CA algorithms, especially with regard to (a) an impact of the number of CCs, (b) gain over load-based, (c) gain over RSRP-based, and (d) an impact of the number of LTE-Adv users,
[0023] FIG. 3 depicts an impact of Rel 8/9 users and finite buffers, especially with regard to (a) an impact of Rel 8/9 users, (b) gain over load-based, (c) gain over load-based (finite), and (d) gain over RSRP-based (finite).
[0024] FIG. 4 depicts an approach proposed in this document.
[0025] FIG. 5 depicts an approach for the joint CC selection in case of backlogged user buffers.
[0026] FIG. 6 depicts an approach for the joint CC selection in case of finite user buffers.
DETAILED DESCRIPTION
[0027] We provide a light-weight (low complexity) solution for joint CC selection and scheduling for LTE-advanced users. This allows for both better throughput performance of LTE advanced users while incurring only a fraction of the energy compared to conventional schemes. Further, the low complexity nature of the solutions allow for easier realization at the base stations.
II. System Description
A. Carrier Aggregation
[0028] To provide high data rates to next generation mobile devices, it becomes in-dispensable for network operators to aggregate several fragmented spectral chunks—a process referred to as carrier aggregation (CA). While CA and hence our contributions are common to next generation technologies (LTE-A, WiMAX) in general, we will describe them in the context of the more popular one, namely LTE-A.
[0029] CA can be of multiple types as shown in FIG. 1( a ). Contiguous or dis-contigous component carriers (CC) within a band (intra-band) can be aggregated, while only dis-contiguous CCs can be aggregated across bands (inter-band) by definition (for eg. CCs in 7(X) MHz and 2 GHz). LTE-A (3GPP release 10 onwards) allows for upto 5 CCs of 20 MHz maximum bandwidth to be aggregated, thereby allowing for LTE-A users to operate with 100 MHz spectrum. LTE-A provides backward compatibility with LTE (3GPP release 8/9) users that operate on only one CC. For every user, when it first (re-)establishes a radio control connection, a CC configured to be its primary CC (PCC). The PCC can then be used to configure additional CCs called secondary CCs (SCCs) that are accessible to LTE-A users. Unlike the PCC, the SCCs can be (de-)activated dynamically for LTE-A users during carrier aggregation using a bitmap.
[0030] Note that, the power consumption per user increases with the number of CCs (bandwidth size) it has to receive and process for control and data information (not just link measurements). Thus, while configuring a LTE-A user with all CCs will provide maximum scheduling diversity gain by allowing the user to be scheduled on any of the resource blocks in all CCs, it will also incur the maximum power consumption. Similarly, while contiguous CA might offer lower scheduling diversity compared to dis-contiguous CA, it will also potentially incur lower power consumption since its implementation can be realized with a single FFT module and a RE component unlike the latter. Hence, the RRM (radio resource management) process in LTE-A incorporates a new feature called CC configuration, whereby each LTE-A user can be configured to operate on a specific set of CCs.
B. Motivation
[0031] Given the multitude of interfaces and applications running on smart mobile devices and their power-hungry nature, configuring the LTE-A users (using CC configuration feature) to operate on a limited set of SCells to save power appears to be a natural solution. However, such energy savings will have to come at the cost of scheduling performance. Hence, a key question we try to address in this work is whether it is possible to save on LTE-A users' power consumption without an appreciable loss in scheduling performance?
[0032] Current approaches to CA configure a PCC based on load and user capabilities (decoupled from scheduling), while allowing all remaining CCs to be used as SCCs, purely from the perspective of maximizing scheduling diversity gain. Hence, to understand the tradeoff between scheduling diversity gain and power consumption reduction, we study the fraction of the maximum (aggregate) scheduling throughput that can be achieved when the number of CCs configured for LTE-A users is limited (compared to five CCs allowed in release 10). For this purpose, we consider two baselines, where we apply the PCC selection criteria to SCC selection as well (i.e. based on user load on CCs or average reference signal received power (RSRP) of CCs), thereby decoupling the latter from scheduling. We compare them against an integrated scheme, where selection of SCCs is determined jointly with scheduling. The performance of these schemes (algorithms employed explained in subsequent sections) is compared against an optimal scheme that allows for access to all CCs for LTE-A users. The result in FIG. 1( b ) clearly illustrates two points: (i) 80-90% of the maximum scheduling gain can be achieved with just half the CCs, namely 2-3 CCs, and (ii) to keep the loss in scheduling performance minimal while saving on user power, one needs to carefully pick the SCCs by integrating the SCC selection process with scheduling. This in turn motivates us to address the joint problem of SCC selection and scheduling for a limited number of CCs in this work.
C. Related Work
[0033] Carrier aggregation, being one of the recent advancements incorporated in LTE-A, is slowly garnering attention from the research community, which provides an overview of the various options and features associated with CA in LTE-A and how it would coexist with legacy LTE users. RRM (scheduling) in OFDMA networks with carrier aggregation has been studied recently in the past couple of years. In a system-level evaluation of CA, CC selection is restricted to only PCC based on load-balancing and LTE-A users are allowed to use all CCs. CA is employed to alleviate interference in heterogeneous networks (macrocells and femtocells), where CCs can be selected autonomously by different networks so as to alleviate interference. There is a problem of search space design (mapping) for control information signaling in CA with cross-CC scheduling. Another step is to extend MIMO scheduling in LIT to work with CA.
[0034] To the best of our knowledge, existing works thus far have not looked at the problem of configuring LTE-A users on a subset of CCs for energy efficiency purposes, wherein the joint problem of CC selection and scheduling becomes important and challenging.
III. Scheduling with Carrier Aggregation
[0035] Recall that there are two aspects to CC selection: PCC (semi-static) selection that is common to both LTE (Rel 8/9) and LTE-A users and SCC (dynamic) selection that is specific to LTE-A users. While our focus is on the joint (dynamic) SCC selection (tot LTE-A users) and scheduling (all users), we do need to specify how the PCCs are chosen first as this impacts the remaining set of SCCs available for each user.
A. PCC Selection
[0036] The choice of PCC is made either based on user load [4] or received signal power (RSRP) on the CCs in existing schemes.
Load-based: The CC that has the smallest number of users (l c ) configured on it thus far is chosen as the PCC for a given user k (P k =arg min c l c ). RSRP-based: The CC that yields the highest average RSRP (r k,c avg , averaged over the spectrum) for a given user (k) is chosen as its PCC (P k =arg max c r k,c avg ).
[0039] The load-based scheme allows for load balancing and utilization of all CCs but is agnostic to the rates seen by the users on the CCs, while the roles are reversed for the RSRP-based scheme. Hence, to strike a balance between the two factors, we employ PCC selection based on the following metric:
[0000]
c
p
=
arg
max
c
r
avg
,
c
l
c
.
B. Joint SCC Selection and Scheduling
[0040] 1) Scheduling Model: We consider a downlink, OFDMA system as in LTE, where data transmissions occur in frames. Every downlink frame is a two-dimensional structure of symbols and sub-channels. Resource allocations to users are made in the granularity of resource blocks (RBs), where an RB spans multiple sub-channels and all symbols in the frame.
[0041] The objective of our scheduling algorithms is to maximize the end-to-end system throughput subject to the popular proportional fairness (PR) model (max Σ k β k log r k ), where β k captures the priority weight of user's QoS class and r k its average throughput. The system solution can be shown to converge to the optimum PF allocation at longer time scales if the base station (BS) scheduler's decisions at each frame are made to maximize the aggregate marginal utility, S max =arg max s {Σ kεS ΔU k } [12]. ΔU k denotes the marginal utility received by user k in a feasible schedule S and is given by
[0000]
β
k
r
k
CA
r
_
k
[0000] for PF, where r k CA is the instantaneous rate received by the user in the frame in the presence of carrier aggregation.
[0042] Thus, at each frame t, user weight
[0000]
v
k
(
t
)
=
β
k
r
_
k
(
t
)
[0000] varies with {right arrow over (r)} k (t) and accounts for both fairness and QoS. The scheduling problem at the BS then reduces to determining the frame schedule that maximizes the following aggregate weighted rate subject to desired CA and resource allocation constraints.
[0000]
S
max
(
t
)
=
arg
max
S
∑
k
∈
S
v
k
(
t
)
·
r
k
CA
(
t
)
(
1
)
[0043] 2) Problem Formulation: The rate received by a user in a frame (r k CA ) depends on the set of RBs allocated to it and the rate obtained on those RBs. This in turn depends on the type of the user (LTE or LTE-A) as well as the CCs assigned to it. While the PCCs are pre-determined for all users (Sec. III-A), we still need to address the joint problem of SCC selection (for LTE-A users with limited number of CCs) and scheduling (for all users), which can be formally stated as follows.
[0000]
SCA
:
Maximize
∑
k
v
k
∑
c
∈
∑
m
∈
ℳ
y
k
,
m
,
c
x
k
,
c
r
k
,
m
,
c
s
.
t
.
∑
c
x
k
,
c
≤
{
n
,
1
}
,
∀
k
∈
{
LTE
-
A
,
LTE
}
∑
k
y
k
,
m
,
c
x
k
,
c
≤
1
,
∀
m
,
c
∑
c
,
m
y
k
,
m
,
c
x
k
,
c
r
k
,
m
,
c
≤
B
k
,
∀
k
x
k
,
c
=
1
,
if
x
k
,
c
-
1
·
k
k
,
c
+
1
=
1
,
∀
c
,
k
∈
LTE
-
A
[0000] x k,c and y k,m,c are indicator variables indicating the allocation of CC c to user k and the allocation of RB m in CC c to user k (whose corresponding rate is r k,m,c ) respectively. C and M represent the set of CCs and RBs in each CC, with |C|=N and |M|=M.
[0044] The first constraint limits the total number of CCs that can be allocated to LTE-A and LTE users to n and 1 respectively. Note that one of the CCs will be pre-assigned (PCC selection, X k,P k =1) for all users. Hence, SCCs need to be selected only for LTE-A users. The second constraint captures the conflict-free assignment of RBs in each CC to users. The third constraint is specific to the case, where users have finite data buffers (B k , corresponding to short-lived data sessions) that limits their net rate allocation. The final constraint is specific to the case, where LTE-A users must be allocated contiguous CCs (for contiguous CA). While this constraint reduces the scheduling flexibility in contiguous CA compared to dis-contiguous CA, it allows for lower power consumption in the former since its implementation can be realized with a single FFT module and a RF component unlike the latter [6]. Thus, depending on the nature of CA (contiguous, C or dis-contiguous, D) and user buffers (backlogged, B or finite, F), we can have four models under which the problem can be addressed, namely DB, FB, CB and CF.
[0045] While the current fairness model between LTE-A and LTE users is based on net throughput (over all CCs), we discuss how our proposed algorithms and guarantees would also apply to an a model favoring LTE-A users by considering per-CC fairness.
C. Problem Hardness
[0046] Theorem 3.1: SCA1 is NT-hard to solve.
[0047] We consider a simpler instance of the problem (SCA), namely with backlogged buffers and CC limit n=1, which is a special case of all the four models BD, BC, FD, FC. We prove its hardness by giving a polynomial-time reduction from the edge-2-colorable problem, thereby automatically establishing the hardness of the four models.
[0048] Given the hardness of our problem, we will now focus on designing efficient algorithms with approximation guarantees that are also easy-to-implement for each of the four models in subsequent sections.
IV. Dis-Contiguous Carrier Aggregation
[0049] In discontiguous CA, users are not constrained in picking CCs that are contiguous.
A. Backlogged User Buffers
[0050] Given a PCC assignment for each user (Sec. III-A), we need to select SCCs for LTE-A users as well as assign RBs in CCs to all the users (subject to their CC assignment) so as to maximize our objective of weighted sum rate. Considering users with backlogged user buffers makes it easier to handle the problem, where we can focus on users that provide the best rate on each RB without any buffer under-flow concerns. However, the hardness still remains, due to the limit on the number of CCs that can be assigned to users. We propose the following greedy algorithm (GCA-BD) to address the problem.
[0000]
Algorithm 1 Greedy Scheduler for SCA-BD: GCA-BD
1.
Input: CC limit n ; PCC List P = {(k, P k )}, ∀k ; rate r k,m,c , ∀k, m, c
2.
K ← K lteA ∪ K lte ; K lteA ← {1, . . . ,| K lteA |}, K lte ← {| K lteA | +1,
. . . ,| K |} ; S ← Ø
3.
Define K lteA ′ ← {k l : k ∈ [1,| K lteA |],l ∈ [1, n − 1]}, k l = k, ∀l
4.
Define φ u ← {(u,c) : c ∈ [1, N]} \ P, ∀u ∈ K lteA ′
5.
While K lteA ′ ≠ Ø
6.
f(S) = Σ c Σ m=1 M max u:(u,c)∈S∪P {v u r u,m,c }
7.
f(S∪(u′, c′)) = Σ c,m max u:(u,c)∈S∪P∪(u′,c′) {v u r u,m,c }
8.
(u*, c*) = arg max (u′,c′)∈φ u′ :u′∈K lteA ′ {f(S∪(u′,c′)) − f(S)}
9.
S ← S∪(u*,c*) ; K lteA ′ ← K lteA ′\u* ;
φ u ← φ u \ (u*,c*), ∀u = u*
10.
End while
11.
k m,c * = arg max k:(k,c)∈S∪P {v k r k,m,c }, ∀m, c
[0051] From the given set of LTE-A users (K lteA ), a virtual user set (k lteA ′) is formed, where each LTE-A user is replicated n−1 times, where n is the limit on the number of CCs (including PCC) that can be assigned to it (steps 2,3). Now the problem reduces to selecting one CC (other than PCC, from φ u ) for each user (u) in k lteA ′ (step 4). This in turn is determined greedily by finding the user-CC pair that yields the highest marginal utility (steps 6-8). Since users have backlogged buffers, the utility of an assignment amounts to finding the best weighted rate on each RB in a CC based on the users who are assigned to that CC and aggregating them (steps 6,7). Also note that, while we are determining CC assignments to LTE-A users, the utilities are determined accounting for both SCC and PCC assignments as well as LTE-A and LTE users (S∪P). Once a user-CC pair is selected, the remaining set of LTE-A users that require SCC assignment is updated (step 9) and the procedure repeats till all SCC assignments to LTE-A users are made (steps 5-10). Then, based on the final assignment of PCC and SCCs, the allocation of RBs to users in each CC can be easily computed (step 11). The bulk of the time complexity comes from step 8, which runs in O(KNMn). This along with the while loop that runs |K lteA|n times, results in a net time complexity of O(K 2 n 2 NM).
[0052] We will now establish an approximation guarantee for Algorithm GCA-BD. Since most of our algorithms leverage sub-modular maximization to provide performance guarantees, we first present some relevant definitions in this regard.
[0053] Partition Matroid: Consider a ground set Ψ and let S be a set of subsets of Ψ. S is a matroid if, (i) ØεS, (ii) If AεS and B ⊂ A, then BεS, and (iii) If A,BεS and |A|>|B|, there exists an element xεA\B, such that B∪{x}εS. A partition matroid is a special case of a matroid, wherein there exists a partition of Ψ into components, φ 1 ,φ 2 , . . . such that AεS if and only if |A∩φ i |≦1, ∀i.
[0054] Sub-modular function: A function ƒ(·) on S is said to be sub-modular and non-decreasing if ∀x, A, B such that A∪{x}εS and B ⊂ A then,
[0000] ƒ( A∪{x })−ƒ( A )≦ f ( B∪{x })−ƒ( B )
[0000] ƒ( A∪{x })−ƒ( A )≧0, and ƒ(Ø)=0
[0055] Theorem 4.1 GCA-BD's worst case performance is within ½ of the optimum.
[0056] Proof. The sub-optimality of maximizing a non-decreasing, sub-modular function over a partition matroid using a greedy algorithm of the form x=arg max xεφi ƒ(A∪{x})−ƒ(A) in every iteration was shown to be bounded by ½ in [13]. We will now show that GCA-BD is such an algorithm, with our scheduling objective corresponding to a non-decreasing, sub-modular function to obtain the desired result.
[0057] Let the ground set be composed of following tuples.
[0000] Ψ={( u,c ):∀ uεK lteA ′,cε[ 1 ,N]}\P
[0000] Now ψ can be partitioned into φ u ={(u,c):∀cε[1,N]}\P. Let S be defined on Ψ as a set of subsets of Ψ such that for all subsets AεS, we have (i) if B ⊂ A, then BεS; (ii) if element xεA\B, then Q∪{x}εS; and (iii) |A∩φ u |≦1, ∀u. This means that S is a partition matroid. Since the limit of n−1 SCCs on each LTE-A user has been translated to that of one CC for every virtual user in K lteA ′, the above conditions enable any AεS to provide a feasible schedule. This allows S (a partition matroid) to capture all feasible schedules and hence our scheduling problem. Our scheduling objective is given as,
[0000]
f
(
A
)
=
∑
c
∈
μ
c
(
A
)
;
where
,
μ
c
(
A
)
=
∑
m
=
1
M
max
u
:
(
u
,
c
)
∈
A
⋃
{
v
u
r
u
,
m
,
c
}
[0000] It can be seen that if B ⊂ A, then μ i (B)≦μ i (A). Further, the difference between A and B is that some CCs have more users assigned to them in A than in B. Hence, when a new user u is added on CC c, the marginal gain the user can contribute to c is potentially less in A than in B. Hence, for an element (u,c) such that A∪{(u,c)} forms a valid schedule, it follows that ƒ(A∪{(u,c)}−ƒ(A)≦ƒ(B∪{(u,c)})−ƒ(B). Note that although the scheduler focuses only on SCC selection for LTE-A users, ƒ(A) incorporates the utility of both SCC assignments to LTE-A users as well as PCC assignment to all users. Since the utility of the schedule corresponding only to the PCC allocation of all users is fixed (constant) and does not impact the SCC selection of LTE-A users (due to backlogged buffers), removing it from ƒ(A) would allow for normalization (ƒ(Ø)=0). This establishes that the function ƒ(A) is indeed sub-modular and non-decreasing. Further, our scheduling problem aims to maximize this non-decreasing, sub-modular function over a partition matroid. Thus, by picking the user-CC pair yielding the highest marginal utility in ƒ(A) in every iteration (steps 6-8), GCA-BD incurs a sub-optimality of ½ that follows from the result.
B. Finite User Buffers
[0058] A key difference with respect to backlogged buffers is that the rate on a RB in a CC for a user is dependent on its own as well as other users' prior allocations as they affect the remaining data in its buffer. We propose an algorithm (Algorithm GCA-FD) that considers all users (not just LTE-A) and assigns SCCs to LTE-A users sequentially in the sense that all SCC assignments to a user are completed before moving to another user. As we will show later, such an approach is crucial in establishing a performance guarantee for the algorithm.
[0000]
Algorithm 2 Greedy Scheduler for SCA-FD: GCA-FD
1. Input: CC limit n ; PCC List P = {(k,P k )}, ∀k ; rate r k,m,c , ∀k,m,c ;
Buffer limit B k , ∀k
2. K ← K lteA ∪K lte ; K lteA ← {1,...,|K lteA |}, K lte ← {|K lteA | + 1,...,|K|};
S ← Ø
3. Define φ u ← {(u,{right arrow over (c)} u ):∀u ε K} ;
{right arrow over (c)} u = <c u,1 ,...,c u,n−1 >,c u,j ε [1,N]\P u ,∀u ε K lteA ;
{right arrow over (c)} u = P u , ∀u ε K lte
4. For k ε [1,|K|]
5. For u ∉ S & u ε K lteA
6. For j ε [1,n − 1]
7. c u,j = arg max c∉ < c u,1 ,...,c u,j−1 > ∪P u {f(S ∪ (u,<c u,1 ,...,c u,j−1 ,c>)) − f(S ∪ (u,<c u,l ,...,c u,j−1 >))}
8. End for
9. End for
10. (u,{right arrow over (c)} u )* = arg max u∉S {f(S ∪ (u,{right arrow over (c)} u )) − f(S)}
11. S ← S ∪ (u,{right arrow over (c)} u )*
12. End for
13. Compute f(S) to obtain RB allocation in each CC.
14.
15. Computing f(S′)
16. Let D k = B k , ∀k ε K; A = Ø ; U = 0
17. For i ε [1,NM]
18. (u*,m*,c*) = arg max u,m,c:(m,c)∉A;(u,c)εS′∪P {v u min{r u,m,c , D u } }
19. U = U + min{r u * ,m * ,c *,D u *} ; D u * = D u * − min{r u * ,m * ,c *,D u *} ;
A ← A ∪ (m*,c*)
20. End for
21. Return U
[0059] The algorithm comprises of three and two levels of decision making for LTE-A and LTE users respectively, which can be explained in a top-down approach for easier exposition. At the highest level, it picks the user with its CC assignment ({right arrow over (c)} u , n−1 SCCs for LTE-A user, 1 fixed PCC P u for all users; step 3) that yield the highest marginal utility in each iteration (steps 10-11). However, to compute this, we need to first determine the assignment of n−1 SCCs if the user is an LTE-A user, of which there are exponential n) possibilities. Hence, the second level of decision making (only for LTE-A users) is to determine the assignment of SCCs for each un-assigned LTE-A user, which in turn is accomplished iteratively for a fixed user by picking the SCC that yields the highest marginal utility (steps 6-8). However, note that, utility is always computed with respect to the entire current allocation (to all users) and not just specific to the given user. Now, computing the utility with respect to a single SCC assignment to a user involves determining the allocation of RBs to users based at the current CC allocations and is still a hard problem due to the finite buffer constraints of users. This leads us to the third level of decision making (common to all users), whereby given an assignment of CCs to users and their finite buffer, we iteratively pick an RB in a CC along with a user allocation that yields the highest marginal utility (steps 15-21).
[0060] Thus, back-tracking the three levels of decision-making, the algorithm determines the assignment of CCs to a user in each iteration. Note that although PCC is fixed for LTE users, the order in which LTE users are picked by the scheduler impacts the assignment of SCCs to LTE-A users. Once the CC assignment to all users is complete, the RB allocation in each CC can be obtained by computing the utility corresponding to the final assignment (step 13). While the for loops (steps 4-12) run in O(K 2 Nn), the core component of utility computation in each iteration (steps 15-21) runs in O(N 2 M 2 K), resulting in a net time complexity of O(K 3 N 3 M 2 n).
[0061] In establishing a performance guarantee for GCA-FD, we will invoke nested sub-modularity, and leverage the following result from [1], [2].
[0062] Lemma 4.1 If the incremental oracle is only α—approximable, then the approximation guarantee of greedy sub-modular maximization changes to
[0000]
α
p
+
α
,
[0000] where the maximization is subject to a p—independence system.
[0063] We now have the following result.
[0064] Theorem 4.2 GCA-FD provides an approximation guarantee of ¼.
[0065] Proof. The proof is based on nested sub-modularity, where we will show that the three levels of decision making in GCA-FD correspond to three sub-modular maximization (SM) problems, each nested within the other.
[0066] Level 1: Specifically, at the highest level, we have the following SM problem.
[0000] Ψ={( u, c u,1 , . . . , c u,n−1 ):∀ uεK lteA ,∀c u,j ε[1 ,N]\P u }
[0000] ∪{( u,P u ):∀ uεK lte }
[0000] φ u ={( u, c u,1 , . . . , c u,n−1 ):∀ c u,j ε[1 ,N]\P u },if uεK lteA
[0000] ={( u,P u )}, if uεK lte
[0000] Now, the set of all feasible schedules S (tuples of user and CC assignments) would correspond to a partition matroid of Ψ, whereby there can be at most only one element from each φ u for any AεS (for LTE users the element is fixed). Note that, while PCC is given for all users, it is still considered as an element for LTE users to include them in scheduling. Further, the scheduling objective function, ƒ(A)=Σ kεK μ k (A), corresponds to the aggregate user utility resulting from the given CC assignment in A as well as finite user buffers. Now, it can be seen that,
[0000] ƒ( A ∪( u,{right arrow over (c)} u )−ƒ( A )≦ƒ( B ∪( u,{right arrow over (c)} u ))−ƒ( B ), where, B ⊂ A
[0000] Since one user is considered at a time, when more elements (users, A\B) are added to A, some of the existing CCs will have more users in A than in B. This in turn reduces the contribution of a new element to A more than to B. In addition to being non-decreasing, incorporating all users in the CC assignment process allows for normalizing ƒ(ƒ(Ø)=0)—although the PCC assignment for LTE users is fixed, it impacts the SCC assignment for LTE-A users due to finite buffer scheduling. Thus, our scheduling objective function is non-decreasing and sub-modular on S. Note that considering all SCC assignments to a LTE-A user before moving to another user is crucial for sub-modularity to hold with finite buffers—otherwise, existing users whose allocations are replaced on some RBs by a new user, will have their freed up data available for later allocations that could result in a higher marginal utility. Since GCA-FD employs a greedy algorithm (step 10) to maximize this non-decreasing, SM objective, its sub-optimality would be bounded by ½ [13], provided we can optimally compute the incremental function (step 10),
[0000]
arg
max
u
∉
A
{
f
(
A
⋃
(
u
,
c
→
u
)
)
-
f
(
A
)
}
(
2
)
[0067] Level 2: Computing the above incremental oracle is a hard problem in itself, with an additional level of hardness arising from the exponential number of SCC assignments possible for an LTE-A user. GCA-FD approximates it using the following SM problem for each LTE-A user.
[0000] Ψ u ={( u 1 ,c ), . . . , ( u n−1 ,c ):∀ cε[ 1 ,N]}P
[0000] with, φ u j ={( u j ,c ):∀ cε[ 1 ,N]}\P
[0000] where the user u is replicated n−1 times (u j =u,jε[1,n−1]). Now the set of all feasible schedules S u (tuples of user and CC) for user u forms a partition matroid of Ψ u . With ƒ(A u ) (A u εS u ) representing the same objective function as before, we can claim that
[0000] ƒ( A u ∪( u j ,c ))−ƒ( A u )≦ƒ( B u ∪( u j ,c ))−ƒ( B u )
[0000] where B u ⊂ A u . This is because, when a new CC is available for user u (assume u's buffer is already used up without loss of generality), we can move some of u's allocation on RBs in existing CCs to the new one, provided we have additional un-used buffer for other users in A for these vacated RBs. Now by adding a CC later in the schedule, we run the risk of using up more of the remaining buffer of other users in A during replacement on other CCs that were added prior to it. Hence, u's ability to replace RBs in the new CC and increase utility is reduced if added later in the schedule, resulting in ƒ being sub-modular on S u . Further, ƒ is non-decreasing and can be normalized to the utility prior to the consideration of user u. Now GCA-FD employs a greedy algorithm (step 7) to maximize this non-decreasing, SM objective. However, computing the incremental oracle arg max j,c {ƒ(A u ∪(u j ,c))−ƒ(A u )} in level 2 still remains a hard problem since it involves determining the optimal allocation of RBs to users in CCs, subject to the CC assignment in A u ∪(u j ,c) as well as finite user buffers, which brings us to the final level.
[0068] Level 3: Computing the incremental oracle in level 2 (level 1) for LTE-A (LTE) users is an extension (to multiple CC) of the RB allocation problem considered in [16] for a single CC with finite user buffers. Hence, its hardness follows from the hardness of the problem in [16]. GCA-FD approximates the problem using the following SM problem given the CC assignment and finite buffers of all users.
[0000] Ψ′={( u,c,m ):∀( u,c )ε A∪P,mε[ 1 ,M]}
[0000] with, φ c,m ={( u,c,m ): uεA∪P}
[0069] Now the set of all feasible schedules S′ (RB allocations) for a given CC assignment to users forms a partition matroid of Ψ′. The scheduling objective for any A′εS′ is given as,
[0000]
f
(
A
′
)
=
∑
u
∈
A
′
⋃
μ
u
(
A
′
)
where
,
μ
u
(
A
′
)
=
v
u
min
{
∑
(
c
,
m
)
:
(
u
,
c
,
m
)
∈
A
′
r
u
,
m
,
c
,
B
u
}
[0000] It is easy to see that ƒ(A′∪(u,c,m))−ƒ(A′)≦ƒ(B′∪(u,c,m))−ƒ(B′), where, B′ ⊂ A′ since the assignment of an RB on a CC to a user later in the schedule will bring potentially lesser utility due to reduced buffer availability (from prior RB allocations). Now, the greedy algorithm in GCA-FD that maximizes this non-decreasing, SM objective (step 18) would directly yield an approximation of ½ since ƒ(A′) can be computed optimally.
[0070] Since the incremental oracle in level 2 can be solved with ½ approximation (from level 3), using the result from lemma 4.1 and applying p=1 for matroids, we obtain that level 2 itself can be solved with
[0000]
1
/
2
1
+
1
/
2
=
1
3
[0000] approximation. However, since level 2 solves the incremental oracle for level 1, we obtain the final approximation for level 1 and hence the whole algorithm as
[0000]
1
/
3
1
+
1
/
3
=
1
4
.
V. Contiguous Carrier Aggregation
[0071] Constraining users with contiguous CC assignment helps energy efficiency but reduces the flexibility in diversity scheduling. However, it also reduces the number of assignment possibilities for a user, thereby simplifying the assignment problem.
A. Backlogged Buffers
[0072] With the PCC already assigned to users, the assignment of SCC to LTE-A users may now be contiguous as well as include the PCC. Hence, there are at most only N−n+1 such contiguous CC combinations for every LTE-A user. We now propose the following algorithm (GCA-BC). The algorithm is similar to the one for discontiguous CA with backlogged buffers (GCA-BD) with the following difference. Instead of assigning one SCC at a time, we now assign all n−1 SCCs jointly to a user, owing to the limited number of contiguous CC configurations that include the PCC n+1 combinations, step 3). Hence, at each iteration, we select a user with his n CC assignment that yields the highest marginal utility (steps 5-7). Once all users have received their CC assignments, we allocate the RBs in CCs to users yielding
[0000] Algorithm 3 Greedy Scheduler for SCA-BC: GCA-BC 1. Input: CC limit n ; PCC List P = {(k, P k )}, ∀k ; rate r k,m,c , ∀k, m, c K ← K lteA ∪ K lte ; 2. K lteA ← {1, . . . ,| K lteA |}, K lte ← {| K lteA | +1, . . . , | K |} ; S ← Ø 3. Define φ u ← {(u,[c, c + n − 1]) : P u ∈[c, c + n − 1]}, c ∈[1, N − n + 1]}, ∀u ∈ K lteA 4. while K lteA ≠ Ø 5. f(S) = Σ c Σ m=1 M max u:(u,c)∈S {v u r u,m,c } 6. f(S ∪(u′,[c u′ ,c u′ + n −1])) = Σ c Σ m=1 M max u:(u,[c u ,c u + n−1]∈S∪(u′,[c u′ ,c u′ + n−1]) {v u r u,m,c } 7. (u*,[c*, c* + n − 1]) = arg max (u′,[c′,c′+n −1])∈φ u′ :u′∈K lteA {f(S ∪ (u′,[c′, c′ + n − 1])) − f(S)} 8. S ← S ∪ (u*,[c*, c* + n − 1]); K lteA ← K lteA \u* 9. End while 10. k m,c * = arg max k:(k,c)∈S∪P {v k r k,m,c }, ∀m, c
the highest weighted rate on that RB and assigned to that CC (step 10). The hulk of the complexity comes from step 7, where the marginal utility calculation for a given new user assignment on n CCs incurs O(nM), with O(K(N−n+1)) such assignments possible, resulting in 0(KNMn). This coupled with O(K) iterations, results in a net complexity of O(K 2 NMn). The limited number of contiguous CC assignments results in a factor n complexity reduction compared to the discontiguous CA case.
[0073] Theorem 5.1: GCA-BC provides an approximation guarantee of 2 1 .
[0074] Proof: The proof is similar to that of GCA-BD, for a slightly different definition of partition matroid. Define the ground set as follows.
[0000] Ψ={( u,[c,c+n− 1]): P u ε[c,c+n− 1],
[0000] ∀ cε[ 1 ,N−n+ 1 ],uεK lteA }
[0000] φ u ={( u,[c,c+n− 1]): P u ε[c,c+n− 1 ],cε[ 1 ,N−n+ 1]}
[0075] Now, the set of all feasible schedules S (tuples of user and contiguous CC assignments) would correspond to a partition matroid of ψ, whereby there can be at most only one element from each φ u for any AεS. Further, our scheduling objective function, ƒ(A)=Σ cεC μ c (A), where
[0000]
μ
c
(
A
)
=
∑
m
max
k
:
(
k
,
c
)
∈
⋃
{
v
k
r
k
,
m
,
c
}
[0000] can be shown to be non-decreasing and sub-modular on S using an argument similar to that in the backlogged buffer case, and can be computed optimally. Hence, the result.
B. Finite Buffers
[0076] Our algorithm for contiguous CA with finite buffers (GCA-FC) is similar to its discontiguous counter-part, namely GCA-FD, with the following difference: the exponential number of discontiguous CC assignments to every user now reduces to just N−n+1 contiguous CC assignments. This reduces the 3 levels of decision making in GCA-FD to 2 levels in GCA-FC for all users. The first level remains to be the selection of the user with its CC assignment (n−1 SCCs for LTE-A user, 1 fixed PCC for all users) that yields the highest marginal utility in each iteration (steps 4-7). However, the second level of determining the set of SCCs in an assignment to the LTE-A user (steps 5-9 in GCA-FD) is completely bypassed given the fixed number of contiguous CC assignments (step 3). This directly leads us to the third level, where for a given assignment of CCs to users and their finite buffers, we iteratively pick an RB in a CC along with a user allocation that yields the highest marginal utility (similar to steps 15-21 in GCA-FD). The utility computation itself runs in O(N 2 M 2 K) as before, of which there are O(KN) use CC assignments possible to select from. This along with K iterations, results in a net time complexity of O(K 3 N 3 M 2 ). Once again, restricting to contiguous CC assignments brings in a complexity reduction factor of n (compared to GCA-FD).
[0000]
Algorithm 4 Greedy Scheduler for SCA-FD: GCA-FC
1.
Input: CC limit n ; PCC List P = {(k, P k )}, ∀k ; rate r k,m,c , ∀k, m, c ;
Buffer limit B k , ∀k
2.
K ← K lteA ∪ K lte ; K lteA ← {1, . . . , | K lteA |}, K lte ← {| K lteA | +1,
. . . ,| K |}; S ← Ø
3.
Define φ u ← {(u, {right arrow over (c)} u ) : ∀u ∈ K;
{right arrow over (c)} u = [c, c + n − 1]: P u ∈ [c, c + n − 1], c ∈ [1, N − n + 1]}, ∀u ∈
K lteA ; {right arrow over (c)} u = P u , ∀u ∈ K lte
4.
while K ≠ Ø
5.
(u, {right arrow over (c)} u )* = arg max (u,{right arrow over (c)} u )∈φ u :u∈K {f(S ∪ (u, {right arrow over (c)} u )) − f(S)}
6.
S ← S ∪ (u, {right arrow over (c)} u )* ; K ← K\u*
7:
end while
8:
Compute f(S) to obtain RB allocation in each CC (similar to
GCA-FD).
[0077] Theorem 5.2: GCA-FC provides an approximation guarantee of 3 1 .
[0078] Proof: The proof is along the lines of that for GCA-FD. The ground set however, incorporates only contiguous CC assignments.
[0000] Ψ={( u,[c,c+n− 1]):∀ uεK lteA ,P u ε[c,c+n− 1],
[0000] ∀ cε[ 1 ,N−n+ 1]}∪{( u,P u ):∀ uεK lte }
[0000] φ u ={( u,[c,c+n− 1]): P u ε[c,c+n− 1],
[0000] ∀ cε[ 1 ,N−n+ 1]}, if uεK lteA
[0000] ={( u,P u )}, if uεK lte
[0000] The definitions of ψ and φ u are essentially subsets of those in the discontiguous case, where all possible SCC combinations were allowed. Hence, the rest of the arguments for sub-modularity hold good given that the objective function is the same. However, unlike GCA-FD, we have only one level of nested sub-modularity. The computation of the incremental oracle (in step 5) amounts to the determination of RB allocations to users given their CC assignment and finite buffers. Latter being a non-decreasing SM problem, results in a half approximation, which in turn results in a net approximation of 1+1/2 1/2 = 3 1 (using lemma 4.1) for the complete algorithm.
VI. Performance Evaluation
A. Set-up
[0079] System Parameters: A frame-level simulator written in C++ is considered for evaluation of the proposed algorithms. A single-cell OFDMA downlink system based on LTE-A is considered, with a cell radius of 600 m. BS operates at P BS =35 dBm power. MS are uniformly distributed within the cell. The Okumura-Hata urban path loss model is employed and coupled with log-normal shadowing and fast (Rayleigh) fading. Each user's Rayleigh channel has a Doppler fading equivalent to a velocity of 3-10 Km/hour. We consider constant bit rate (CBR) applications as the generators of traffic. We consider an LTE-A downlink frame of 1 ms, which consists of two slots (sub-frames) of 0.5 ins each. Each slot consists of 7 symbols. Resource allocations to users are made at the granularity of physical resource blocks (PRB). Each PRB consists of 12 sub-carriers of 15 KHz each. The number of PRBs in the system scales with the available bandwidth (25 for 5 MHz, 50 for 10 MHz, etc.). Of the 14 symbols per frame, 11 are available for data. Given a maximum of five bits (64-QAM) that can be loaded in each symbol, the peak downlink (SISO) data rate for a 5 MHz CC is 16.5 Mbps, which in turn can get boosted to 82.5 Mbps by aggregating 5 such CCs. The rate supported by a user on a RB is obtained by mapping the received SNR at the user to one of the 27 MCS values in LTE-A.
[0080] Baselines and Metrics: We compare our proposed algorithms for joint CC selection and scheduling with two baselines: Load-based and RSRP-based, wherein the SCC selection is made based on metrics outlined in Section III-A for PCC selection, while scheduling itself (given a CC assignment) follows the same approach as in our proposed algorithms. The scheduling algorithms are evaluated per frame, where the main of evaluation is aggregate network throughput (v k =1, ∀k). The results are averaged over twenty topologies. The limit on the #SCCs, number of users, fraction of LTE users, and user buffers are the parameters of evaluation. The default parameters of operation (when not specified) include a system with: 10 users (all LTE-A users) with backlogged buffers and 5 total CCs (each with 5 Mhz spectrum in the 2.1 GHz band) with a limit of 2 CCs per LTE-A user.
B. Performance of Joint CC Selection and Scheduling
[0081] While limiting the number of SCCs helps reduce energy consumption for LTE-A users, we need to understand if the joint CC selection and scheduling will keep the degradation in throughput performance small. We consider the backlogged buffer case, where the problem is optimally solvable when there is no on the #CCs (assign all CCs to every LTE-A user). We compare the loss in throughput of our integrated (GRA-BD and GRA-BC) algorithms for discontiguous (dis) and contiguous (con) CA respectively due to limited #CCs against the optimal (allowing for all CCs). The result FIG. 2( a ) clearly shows that OUT algorithms help achieve 80-90% of the maximum performance in practice (compared to the worst case guarantees of half) while operating on just half the number of CCs. Thus, with the help of efficiently designed algorithms for joint CC selection and scheduling, energy reduction for LTE-A users can be realized without sacrificing any appreciable throughput performance.
[0082] We also evaluate the benefit of integrating CC selection with scheduling by comparing our algorithms against decoupled CC selection and scheduling schemes (Load-based and RSRP-based CC selection) in FIGS. 2( b ) and ( c ). Topologies with five and ten CCs are considered with five and ten LTE-A users respectively. Five observations can be made: (i) in the region of practical interest (limiting CCs to 2-3), we see that gains of 15-30% can be had from integrating CC selection with scheduling; (ii) gains for contiguous CA are slightly inferior to those of discontiguous CA as contiguous CC selection restricts scheduling diversity gain; (iii) gains decrease as the limit on)! CCs is relaxed since the need for careful CC selection diminishes in this case; (iv) gains are more over the RSRP-based scheme, indicating that load-balancing users across CCs is relatively more beneficial when CC selection is decoupled from scheduling; and (v) more CCs (10) provides increased room for scheduling diversity and hence higher gains.
[0083] In contrast to FIG. 2( a ), we now fix the limit on the #CCs and study the loss in performance as a function of the # users in FIG. 2( d ). It can be seen that to keep the loss in performance small, the system needs sufficient scheduling diversity. This can be achieved either with a larger limit on #CCs, or with a larger number of users. Hence, for a total of 5 CCs, a smaller limit (2) on CCs requires more users (10) to achieve over 90% of optimal performance, while a limit of 3 CCs requires only 5 users. Further, contiguous CA reduces the ability to leverage scheduling diversity. This coupled with a larger # of CCs (10), requires either a larger limit (3) on CCs or a larger number of users (20) to achieve over 90% of optimal performance.
C. Impact of User Heterogeneity and Finite Buffers
[0084] We study the impact of user heterogeneity (coexistence of LTE-A and LTE users) on the performance of CA as an increasing function of LTE users. The algorithms employed are GCA-BD and GCA-BC for the backlogged buffer case. FIG. 3( a ) indicates that when the system transitions from being predominantly LTE-A to predominantly LTE, the loss in performance can be as high as 30%. Access to more CCs allows LTE-A users to provide more scheduling diversity. Note that the loss in performance in FIG. 3( a ) is only due to diminishing gain in scheduling diversity across CCs since our fairness model (in scheduling) computes weights only based on net throughput of LTE-A users and not their per-CC throughput. If fairness based on per-CC throughput is employed, then one can expect the loss in performance with increasing number of LTE users to further increase.
[0085] The gain of our algorithms over the load-based scheme is studied as a fraction of the LTE users in the system in FIG. 3( b ). Two observations can be made: (i) Irrespective of the fraction of LTE users, gains of 15-20% can be had. This is because our algorithms employ a PCC selection mechanism that incorporates both load and RSRP metrics, along with a joint SCC selection and scheduling scheme. While the impact of the latter component reduces with increasing of LTE users, the impact of the former component increases as it applies to LTE users; (ii) The gain surprisingly increases with increasing fraction of LTE users for contiguous CA to as high as 25-35%. Recall that the ability to leverage scheduling diversity is lesser with contiguous CA. Hence, when the number of LTE-A users is very small, the need to carefully select their SCCs is all the more pronounced.
[0086] We finally study the impact of finite buffers on our algorithms, GCA-FD and GCA-FC and compare them against the baselines in FIGS. 3( c ) and ( d ). When the amount of user buffer is small, it becomes the performance bottleneck, leaving little room for any performance optimization and gains. However, as the buffer size increases, there is more room to leverage the increased scheduling diversity gain with CA, resulting in higher gains. The rest of the inferences comparing our algorithms for finite buffer against the baselines are similar to those in the backlogged buffer case.
[0087] Referring to FIG. 4 , the system picks the primary CC for a new user as
[0000]
c
p
=
arg
max
c
r
avg
,
c
l
c
[0000] in step 1 (block 402 ). Here, r k,c avg is the average reference signal received power (RSRP) averaged over the spectrum for user ‘k’ on component carrier ‘c’. l c is the load on carrier c and could represent the number of users already assigned to carrier c or the traffic demand on carrier c, etc. Then, the system proceeds with step 2 if joint CC selection and scheduling do not apply (block 404 ), and selects secondary CCs up to the allocated limit for a new LTE advanced user based on the same criteria as for PCC in step 2 (block 406 ). The system proceed with step 3 in case of joint CC selection and scheduling (block 404 ), and performs joint secondary CC selection (for LTE advanced users) and resource scheduling (for all users) in step 3 (block 408 ). The process of joint CC selection and scheduling in step 3 (block 408 ) would vary depending on whether the users have finite user buffers or backlogged user buffers. We describe the approach for both these cases separately.
[0088] An approach for the backlogged user buffers is shown in FIG. 5 . In step 1 (block 502 ), the system picks a user and CC pair such that assigning the CC as a secondary to the LTE-adv user yields the highest incremental value to the current schedule. In step 1 (block 502 ), the system determines the incremental value of a CC assignment to a user amounts to finding the best utility/metric (eg. weighted rate) on each resource block (RB) in a CC based on the users who are assigned to that CC and aggregating them. Further in step 1 (block 502 ), if the CCs that are assigned to a LTE-adv user are constrained to be contiguous, instead of assigning one CC at a time, the solution would consider all combinations (N−n+1) of ‘n’ CCs to an LTE-adv user in determining the best set of n−1 CCs that need to be assigned to the LTE-adv user. Here ‘n’ is the limit on number of secondary CCs that can be assigned to an LTE-adv user out of a total of N. Then, in step 2 (block 504 ), the system continues the assignment till all LTE-adv users have their limited share of secondary CCs assigned.
[0089] An approach for the finite user buffers is shown in FIG. 6 . In step 1 (block 602 ), the system picks a user along with its set of secondary CC assignments such that assigning the set of n−1 secondary CCs to the LTE-adv user yields the highest incremental value to the current schedule. In step 1a (block 604 ), the system picks secondary CCs one by one iteratively for the given user such that addition of the new CC provides the highest incremental value. In step lai (block 606 ), the sys em determines the value of assigning a CC to a user by allocating RBs in the CC to users based on current CC assignments: at each step the RB yielding the highest incremental value to a user taking its finite buffer into account is selected and assigned to the user. Then, in step 2 (block 608 ), the system continues the assignment till all LTE-adv users have their set of secondary CCs assigned.
[0090] In this document, we have looked at the problem of energy efficient carrier aggregation for LTE-A systems. We have shown that with the help of efficiently designed joint CC selection and scheduling algorithms, one can obtain close-to the maximum scheduling performance of CA systems, while expending only half the energy for its mobile devices. In this regard, we proposed algorithms with performance guarantees under various models of contiguous and discontiguous CA as well as backlogged and finite user buffers. Our extensive evaluations validated our hypothesis as well as highlighted the performance gains of our proposed solutions over baseline schemes.
[0091] The foregoing is to be understood as being in every respect illustrative and exemplary, but not restrictive, and the scope of the invention disclosed herein is not to be determined from the Detailed Description, but rather from the claims as interpreted according to the full breadth permitted by the patent laws. It is to be understood that the embodiments shown and described herein are only illustrative of the principles of the present invention and that those skilled in the art may implement various modifications without departing from the scope and spirit of the invention. Those skilled in the art could implement various other feature combinations without departing from the scope and spirit of the invention. | A method implemented in a mobile communications system is disclosed. The method includes selecting primary component carrier c p for a new user according to a formula, and performing joint secondary CC selection for one or more Long Term Evolution (LTE)-Advanced users and resource scheduling for one or more LTE users and said one or more LTE-Advanced users. Other methods, systems, and apparatuses also are disclosed. | 7 |
BACKGROUND OF THE INVENTION
1. Field of the Invention
The present invention provides nucleotide sequences from coryneform bacteria coding for the pgi gene and a process for increasing metabolic flux through the pentose phosphate cycle by attenuating the pgi gene.
2. Background Information
Nucleotides, vitamins and in particular L-amino acids, very particularly lysine and tryptophan, are used in the foodstuffs industry, in animal nutrition, human medicine and the pharmaceuticals industry.
It is known that these substances are produced by fermentation using strains of coryneform bacteria, in particular Corynebacterium glutamicum . Due to its great significance, efforts are constantly being made to improve the production process. Improvements to the process may relate to measures concerning fermentation technology, for example stirring and oxygen supply, or to the composition of the nutrient media, such as for example sugar concentration during fermentation, or to working up of the product by, for example, ion exchange chromatography, or to the intrinsic performance characteristics of the microorganism itself.
The performance characteristics of these microorganisms are improved using methods of mutagenesis, selection and mutant selection. In this manner, strains are obtained which are resistant to antimetabolites or are auxotrophic for regulatorily significant intermediates and produce nucleotides, vitamins or amino acids.
For some years, methods of recombinant DNA technology have also been used to improve strains of Corynebacterium which produce nucleotides, vitamins and L-amino acids.
A typical raw material for the production of these compounds is glucose, which is usually used in the form of starch hydrolysate. Sucrose is also used as a raw material.
On cellular absorption, glucose is phosphorylated with consumption of phosphoenolpyruvate (phosphotransferase system) (Malin & Bourd, Journal of Applied Bacteriology 71, 517-523 (1991)) and is then available to the cell as glucose-6-phosphate. Sucrose is converted into fructose and glucose-6-phosphate by a phosphotransferase system (Shio et al., Agricultural and Biological Chemistry 54, 1513-1519 (1990)) and invertase reaction (Yamamoto et al., Journal of Fermentation Technology 64, 285-291 (1986)).
During glucose catabolism, the enzymes glucose-6-phosphate dehydrogenase (EC 1.1.14.9) and glucose-6-phosphate isomerase (EC 5.3.1.9) compete for the substrate glucose-6-phosphate. The enzyme glucose-6-phosphate isomerase catalyses the first reaction step of the Embden-Meyerhof-Parnas pathway or glycolysis, namely conversion into fructose-6-phosphate. The enzyme glucose-6-phosphate dehydrogenase catalyses the first reaction step of the oxidative portion of the pentose phosphate cycle, namely conversion into 6-phosphogluconolactone.
In the oxidative portion of the pentose phosphate cycle, glucose-6-phosphate is converted into ribulose-5-phosphate, so producing reduction equivalents in the form of NADPH. As the pentose phosphate cycle proceeds further, pentose phosphates, hexose phosphates and triose phosphates are interconverted. Pentose phosphates, such as for example 5-phosphoribosyl-1-pyrophosphate are required, for example, in nucleotide biosynthesis. 5-Phosphoribosyl-1-pyrophosphate is moreover a precursor for aromatic amino acids and the amino acid L-histidine. NADPH acts as a reduction equivalent in numerous anabolic biosyntheses. Four molecules of NADPH are thus consumed for the biosynthesis of one molecule of L-lysine from oxalacetic acid.
The significance of the pentose phosphate cycle to biosynthesis and the production of amino acids, in particular L-lysine, by coryneform bacteria is known and has been the focus of much special interest.
Oishi & Aida (Agricultural and Biological Chemistry 29, 83-89 (1965)) have accordingly reported the “hexose monophosphate shunt” of Brevibacterium ammoniagenes . Investigations using 13 C isotope methods by Ishino et al. (Journal of General and Applied Microbiology 37, 157-165 (1991)) into glucose metabolism during glutamic acid and lysine fermentation indicate a correlation between lysine production and metabolic flux through the pentose phosphate pathway.
SUMMARY OF THE INVENTION
Object of the Invention
The inventors set themselves the object of providing a process for increasing metabolic flux through the pentose phosphate cycle.
Description of the Invention
Nucleotides, vitamins and in particular L-amino acids, very particularly L-lysine and L-tryptophan, are used in the foodstuffs industry, in animal nutrition, human medicine and the pharmaceuticals industry. There is accordingly general interest in providing improved processes for the production of these products.
The present invention provides an isolated polynucleotide containing a polynucleotide sequence selected from the group
a) polynucleotide which is at least 70% identical to a polynucleotide which codes for a polypeptide containing the amino acid sequence of SEQ ID no. 2,
b) polynucleotide which codes for a polypeptide which contains an amino acid sequence which is at least 70% identical to the amino acid sequence of SEQ ID no. 2,
c) polynucleotide which is complementary to the polynucleotides of a) or b), and
d) polynucleotide containing at least 100 successive bases of the polynucleotide sequence of a), b) or c).
The present invention also provides the polynucleotide as claimed in claim 1, wherein it preferably comprises replicable DNA containing:
(i) the nucleotide sequence shown in SEQ ID no. 1 or
(ii) at least one sequence which matches the sequence (i) within the degeneration range of the genetic code, or
(iii) at least one sequence which hybridises with the complementary sequence to sequence (i) or (ii) and optionally
(iv) functionally neutral sense mutations in (i).
The present invention also provides
a polynucleotide as claimed in claim 2, containing the nucleotide sequence as shown in SEQ ID no. 1,
a polynucleotide as claimed in claim 2 which codes for a polypeptide which contains the amino acid sequence as shown in SEQ ID no. 2,
a vector containing the polynucleotide as claimed in claim 1, indent d, in particular pMC1, deposited in E. coli DSM 12969.
and coryneform bacteria acting as host cells which contain the vector as claimed in claim 6.
“Isolated” means separated from its natural environment. “Polynucleotide” generally relates to polyribonucleotides and polydeoxyribonucleotides, wherein the RNA or DNA may be unmodified or modified.
“Polypeptides” are taken to mean peptides or proteins which contain two or more amino acids connected by peptide bonds.
The polypeptides according to the invention include the polypeptide according to SEQ ID no. 2, in particular those having the biological activity of glucose-6-phosphate isomerase and also those which are at least 70% identical to the polypeptide according to SEQ ID no. 2, preferably being at least 80% and particularly preferably at least 90% to 95% identical to the polypeptide according to SEQ ID no. 2 and having the stated activity.
This invention furthermore relates to a process for the fermentative production of nucleotides, vitamins and in particular L-amino acids, very particularly lysine and tryptophan, using coryneform bacteria which in particular already produce the stated substances and in which the nucleotide sequences coding for the pgi gene are attenuated, in particular expressed at a low level.
In this connection, the term “attenuation” describes the reduction in or switching off of the intracellular activity of one or more enzymes (proteins) in a microorganism, which enzymes are coded by the corresponding DNA, for example by using a weak promoter or a gene or allele which codes for a corresponding enzyme having low activity or inactivates the corresponding enzyme (protein) and optionally by combining these measures.
The microorganisms provided by the present invention are capable of producing nucleotides, vitamins and in particular L-amino acids, very particularly lysine and tryptophan, from glucose, sucrose, lactose, fructose, maltose, molasses, starch, cellulose or from glycerol and ethanol. The microorganisms may comprise representatives of the coryneform bacteria in particular of the genus Corynebacterium. Within the genus Corynebacterium, Corynebacterium glutamicum may in particular be mentioned, which is known in specialist circles for its ability to produce L-amino acids.
Suitable strains of the genus Corynebacterium, in particular of the species Corynebacterium glutamicum , are the known wild type strains
Corynebacterium glutamicum ATCC13032
Corynebacterium acetoglutamicum ATCC15806
Corynebacterium acetoacidophilum ATCC13870
Corynebacterium thermoaminogenes FERM BP-1539
Brevibacterium flavum ATCC14067
Brevibacterium lactofermentum ATCC13869 and
Brevibacterium divaricatum ATCC14020
and mutants or strains produced therefrom which produce nucleotides, vitamins or L-amino acids,
such as for example the 5′-inosinic acid producing strains
Corynebacterium ammoniagenes ATCC15190
Corynebacterium ammoniagenes ATCC15454 and
Corynebacterium glutamicum ATCC14998 or
such as for example the 5′-guanylic acid producing strains
Corynebacterium glutamicum ATCC21171 and
Corynebacterium ammoniagenes ATCC19216 or
such as for example the D-pantothenic acid producing strains
Corynebacterium glutamicum
ATCC13032/pECM3ilvBNCD, pEKEX2panBC and
Corynebacterium glutamicum ATCC13032/pND-D2 or
such as for example the L-lysine producing strains
Corynebacterium glutamicum FERM-P 1709
Brevibacterium flavum FERM-P 1708
Brevibacterium lactofermentum FERM-P 1712
Corynebacterium glutamicum FERM-P 6463
Corynebacterium glutamicum FERM-P 6464 and
Corynebacterium glutamicum DSM 5714 or
such as for example the L-tryptophan producing strains
Corynebacterium glutamicum ATCC21850 and
Corynebacterium glutamicum KY9218(pKW9901).
The inventors were successful in isolating the novel pgi gene coding for the enzyme glucose-6-phosphate isomerase (EC 5.3.1.9) from C. glutamicum.
In order to isolate the pgi gene or also other genes from C. glutamicum , a gene library of this microorganism is first constructed in E. coli . The construction of gene libraries is described in generally known textbooks and manuals. Examples which may be mentioned are the textbook by Winnacker: Gene und Klone, Eine Einführung in die Gentechnologie (Verlag Chemie, Weinheim, Germany, 1990) or the manual by Sambrook et al.: Molecular Cloning, A Laboratory Manual (Cold Spring Harbor Laboratory Press, 1989). One very well known gene library is that of E. coli K-12 strain W3110, which was constructed by Kohara et al. (Cell 50, 495-508 (1987)) in λ-vectors. Bathe et al. (Molecular and General Genetics, 252:255-265, 1996) describe a gene library of C. glutamicum ATCC13032, which was constructed using the cosmid vector SuperCos I (Wahl et al., 1987, Proceedings of the National Academy of Sciences USA, 84:2160-2164) in E. coli K-12 strain NM554 (Raleigh et al., 1988, Nucleic Acids Research 16:1563-1575). Börmann et al. (Molecular Microbiology 6(3), 317-326)) again describe a gene library of C. glutamicum ATCC13032 using cosmid pHC79 (Hohn & Collins, Gene 11, 291-298 (1980)). O'Donohue (The Cloning and Molecular Analysis of Four Common Aromatic Amino Acid Biosynthetic Genes from Corynebacterium glutamicum . Ph.D. Thesis, National University of Ireland, Galway, 1997) describes the cloning of C. glutamicum genes using the λ Zap Expression system described by Short et al. (Nucleic Acids Research, 16: 7583).
A gene library of C. glutamicum in E. coli may also be produced using plasmids such as pBR322 (Bolivar, Life Sciences, 25, 807-818 (1979)) or pUC9 (Vieira et al., 1982, Gene, 19:259-268). Suitable hosts are in particular those E. coli strains with restriction and recombination defects, such as for example strain DH5α ((Jeffrey H. Miller: “A Short Course in Bacterial Genetics, A Laboratory Manual and Handbook for Escherichia coli and Related Bacteria”, Cold Spring Harbor Laboratory Press, 1992).
The gene library is then inserted into an indicator strain by transformation (Hanahan, Journal of Molecular Biology 166, 557-580, 1983) or electroporation (Tauch et.al., 1994, FEMS Microbiological Letters, 123:343-347). The indicator strain is distinguished by having a mutation in the gene in question which causes a detectable phenotype. The E. coli mutant DF1311 described by Kupor & Fraenkel (Journal of Bacteriology 100: 1296-1301 (1969)) is of significance for the purposes of the present invention. This strain carries mutations in the pgi and pgl genes, as a result of which growth on glucose is severely inhibited. After transformation with a vector containing the pgi gene, growth on glucose is re-established. One example of such a vector containing the pgi gene is pAMC1 (FIG. 1 ).
The long DNA fragments cloned with the assistance of cosmids or other λ-vectors may subsequently in turn be sub-cloned in usual vectors suitable for DNA sequencing.
DNA sequencing methods are described inter alia in Sanger et al. (Proceedings of the National Academy of Sciences of the United States of America USA, 74:5463-5467, 1977).
The resultant DNA sequences may then be investigated using known algorithms or sequence analysis programs, for example Staden's program (Nucleic Acids Research 14, 217-232(1986)), Butler's GCG program (Methods of Biochemical Analysis 39, 74-97 (1998)), Pearson & Lipman's FASTA algorithm (Proceedings of the National Academy of Sciences USA 85,2444-2448 (1988)) or Altschul et al.'s BLAST algorithm (Nature Genetics 6, 119-129 (1994)) and compared with the sequence entries available in publicly accessible databases. Publicly accessible nucleotide sequence databases are, for example, the European Molecular Biology Laboratory database (EMBL, Heidelberg, Germany) or the National Center for Biotechnology Information database (NCBI, Bethesda, Md., USA).
These were the methods used to obtain the novel DNA sequence coding for the pgi gene from C. glutamicum , which is provided by the present invention as SEQ ID no. 1. The amino acid sequence of the corresponding protein was furthermore deduced from the above DNA sequence using the methods described above. SEQ ID no. 2 shows the resultant amino acid sequence of the product of the pgi gene.
Coding DNA sequences arising from SEQ ID NO.1 by the degeneracy of the genetic code are also provided by the present invention. Similarly, DNA sequences which hybridise with SEQ ID no. 1 or portions of SEQ ID no. 1 are also provided by the present invention. Finally, DNA sequences produced by the polymerase chain reaction (PCR) using primers obtained from SEQ ID no. 1 are also provided by the present invention.
The person skilled in the art may find instructions for identifying DNA sequences by means of hybridisation inter alia in the manual “The DIG System Users Guide for Filter Hybridization” from Boehringer Mannheim GmbH (Mannheim, Germany, 1993) and in Liebl et al. (International Journal of Systematic Bacteriology (1991) 41: 255-260). The person skilled in the art may find instructions for amplifying DNA sequences using the polymerase chain reaction (PCR) inter alia in the manual by Gait: Oligonucleotide synthesis: a practical approach (IRL Press, Oxford, UK, 1984) and in Newton & Graham: PCR (Spektrum Akademischer Verlag, Heidelberg, Germany, 1994).
The inventors discovered that, after attenuation of the pgi gene, coryneform bacteria exhibit an improved metabolic flux through the pentose phosphate cycle and produce nucleotides, vitamins and in particular L-amino acids, particularly preferably L-lysine and L-tryptophan, in an improved manner.
Attenuation may be achieved by reducing or switching off either the expression of the pgi gene or the catalytic properties of the enzyme protein. Both measures may optionally be combined.
Reduced gene expression may be achieved by appropriate control of the culture or by genetic modification (mutation) of the signal structures for gene expression. Signal structures for gene expression are, for example, repressor genes, activator genes, operators, promoters, attenuators, ribosome binding sites, the start codon and terminators. The person skilled in the art will find information in this connection for example in patent application WO 96/15246, in Boyd & Murphy (Journal of Bacteriology 170: 5949 (1988)), in Voskuil & Chambliss (Nucleic Acids Research 26: 3548 (1998), in Jensen & Hammer (Biotechnology and Bioengineering 58: 191 (1998)), in Patek et al. (Microbiology 142: 1297 (1996) and in known textbooks of genetics and molecular biology, such as for example the textbook by Knippers (“Molekulare Genetik”, 6th edition, Georg Thieme Verlag, Stuttgart, Germany, 1995) or by Winnacker (“Gene und Klone”, VCH Verlagsgesellschaft, Weinheim, Germany, 1990).
Mutations which result in modification or reduction of the catalytic properties of enzyme proteins are known from the prior art; examples which may be mentioned are the papers by Qiu & Goodman (Journal of Biological Chemistry 272: 8611-8617 (1997)), Sugimoto et al. (Bioscience Biotechnology and Biochemistry 61: 1760-1762 (1997)) and Möckel (“Die Threonindehydratase aus Corynebacterium glutamicum : Aufhebung der allosterischen Regulation und Struktur des Enzyms”, Forschungszentrum Jülich reports, Jül-2906, ISSN09442952, Jülich, Germany, 1994). Summary presentations may be found in known textbooks of genetics and molecular biology such as, for example, the textbook by Hagemann (“Allgemeine Genetik”, Gustav Fischer Verlag, Stuttgart, 1986).
Mutations which may be considered are transitions, insertions, deletions and transversions Depending upon the effect of exchanging the amino acids upon enzyme activity, the mutations are known as missense mutations or nonsense mutations. Insertions or deletions of at least one base pair in a gene give rise to frame shift mutations, as a result of which the incorrect amino acids are inserted or translation terminates prematurely. Deletions of two or more codons typically result in a complete breakdown of enzyme activity. Instructions for producing such mutations belong to the prior art and may be found in known textbooks of genetics and molecular biology, such as for example the textbook by Knippers (“Molekulare Genetik”, 6th edition, Georg Thieme Verlag, Stuttgart, Germany, 1995), by Winnacker (“Gene und Klone”, VCH Verlagsgesellschaft, Weinheim, Germany, 1990) or by Hagemann (“Allgemeine Genetik”, Gustav Fischer Verlag, Stuttgart, 1986).
One example of insertion mutagenesis is plasmid pMC1 (FIG. 2 ), by means of which the pgi gene may be mutated. Plasmid pMC1 consists of plasmid pBGS8, described by Spratt et al. (Gene 41: 337 (1986)), into which an internal fragment of the pgi gene, shown in SEQ ID no. 3, has been inserted. After transformation and homologous recombination into the pgi gene (insertion), this plasmid brings about a complete loss of enzyme function. Instructions and explanations relating to insertion mutagenesis may be found, for example, in Schwarzer & Pühler (Bio/Technology 9, 84-87 (1991)) or Fitzpatrick et al. (Applied Microbiology and Biotechnology 42, 575-580 (1994)).
In addition to attenuation of the pgi gene, it may additionally be advantageous for the production of nucleotides, vitamins and in particular L-amino acids, very particularly L-lysine and L-tryptophan, to amplify, in particular overexpress, one or more enzymes of the particular biosynthetic pathway.
For example, when producing nucleotides, it is thus possible
simultaneously to overexpress the purF gene coding for glutamine-PRPP amidotransferase and/or
simultaneously to overexpress the carAB gene coding for carbamoylphosphate synthetase.
For example, when producing L-lysine, it is thus possible
simultaneously to overexpress the dapA gene coding for dihydrodipicolinate synthase (EP-B 0 197 335), and/or
simultaneously to amplify a DNA fragment which imparts S-(2-aminoethyl)cysteine resistance (EP-A 0 088 166).
For example, when producing L-tryptophan, it is thus possible
simultaneously to overexpress the tkt gene coding for transketolase and/or
simultaneously to overexpress the prs gene coding for phosphoribosylpyrophosphate synthase.
Apart from attenuating the pgi gene, it may furthermore be advantageous for the production of nucleotides, vitamins and in particular L-amino acids, very particularly L-lysine and L-tryptophan, to switch off unwanted secondary reactions (Nakayama: “Breeding of Amino Acid Producing Micro-organisms”, in: Overproduction of Microbial Products, Krumphanzl, Sikyta, Vanek (eds.), Academic Press, London, UK, 1982).
The microorganisms containing the polynucleotide as claimed in claim 1 are also provided by the invention and may be cultured continuously or discontinuously using the batch process or the fed batch process or repeated fed batch process for the purpose of producing nucleotides, vitamins and in particular L-amino acids, very particularly L-lysine and L-tryptophan. A summary of known culture methods is given in the textbook by Chmiel (Bioprozesstechnik 1. Einführung in die Bioverfahrenstechnik (Gustav Fischer Verlag, Stuttgart, 1991)) or in the textbook by Storhas (Bioreaktoren und periphere Einrichtungen (Vieweg Verlag, Braunschweig/Wiesbaden, 1994)).
The culture medium to be used must adequately satisfy the requirements of the particular strains. Culture media for various microorganisms are described in “Manual of Methods for General Bacteriology” from American Society for Bacteriology (Washington D.C., USA, 1981). Carbon sources which may be used include sugars and carbohydrates, such as for example glucose, sucrose, lactose, fructose, maltose, molasses, starch and cellulose, oils and fats, such as for example soya oil, sunflower oil, peanut oil and coconut oil, fatty acids, such as for example palmitic acid, stearic acid and linoleic acid, alcohols, such as for example glycerol and ethanol, and organic acids, such as for example acetic acid. These substances may be used individually or as a mixture. Nitrogen sources which may be used comprise organic compounds containing nitrogen, such as peptones, yeast extract, meat extract, malt extract, corn steep liquor, soya flour and urea or inorganic compounds, such as ammonium sulfate, ammonium chloride, ammonium phosphate, ammonium carbonate and ammonium nitrate. The nitrogen sources may be used individually or as a mixture. Phosphorus sources which may be used are phosphoric acid, potassium dihydrogen phosphate or dipotassium hydrogen phosphate or the corresponding salts containing sodium. The culture medium must furthermore contain metal salts, such as for example magnesium sulfate or iron sulfate, which are necessary for growth. Finally, essential growth-promoting substances such as amino acids and vitamins may also be used in addition to the above-stated substances. Suitable precursors may furthermore be added to the culture medium. The stated feed substances may be added to the culture as a single batch or be fed appropriately during cultivation.
Basic compounds, such as sodium hydroxide, potassium hydroxide, ammonia or ammonia water, or acidic compounds, such as phosphoric acid or sulfuric acid, are used appropriately to control the pH of the culture. Antifoaming agents, such as for example fatty acid polyglycol esters, may be used to control foaming. Suitable selectively acting substances, such as for example antibiotics, may be added to the medium in order to maintain plasmid stability. Oxygen or gas mixtures containing oxygen, such as for example air, are introduced into the culture in order to maintain aerobic conditions. The temperature of the culture is normally from 20° C. to 45° C. and preferably from 25° C. to 40° C. The culture is continued until a maximum quantity of the desired product has been formed. This objective is normally achieved within 10 hours to 160 hours.
Metabolic flux through the pentose phosphate cycle is determined by using a culture containing C-1 labelled 13C glucose as the carbon source. This analytical method is based on the known fact that when glucose is catabolised by the pentose phosphate cycle, the C-1 position is converted into carbon dioxide, whereas when it is catabolised by glycolysis, the 13C-1 labelling is passed on to the C-3 position of the pyruvate. The 13C content of the C-3position of the pyruvate is determined at the appropriate time by using nuclear magnetic resonance or mass spectroscopy methods to investigate extracellular metabolites, such as for example lactate and in particular lysine. Alternatively, amino acids may be obtained by acid hydrolysis from the biomass and the 13C content in the individual carbon atoms of the particular amino acid may then be determined. The person skilled in the art may find comprehensive instructions, in particular in relation to computer-aided data evaluation of the 13C content in various carbon atoms of the investigated metabolites in Sonntag et al. (European Journal of Biochemistry 213, 1325-1331 (1993)), Sonntag et al. (Applied Microbiology and Biotechnology 44, 489-495 (1995)), Marx et al. (Biotechnology and Bioengineering 49, 111-129 (1996)) and Marx et al. (Biotechnology and Bioengineering 56, 168-180 (1997)).
Methods for determining nucleotides, vitamins and L-amino acids are known from the prior art. L-Amino acids may, for example, be analysed using anion exchange chromatography with subsequent ninhydrin derivatisation, as described by Spackman et al. (Analytical Chemistry, 30, (1958), 1190), or they may be analysed by reversed phase HPLC as described in Lindroth et al. (Analytical Chemistry (1979) 51: 1167-1174).
The following microorganism has been deposited with Deutschen Sammlung für Mikrorganismen und Zellkulturen (DSMZ, Braunschweig, [sic] The following microorganism has been deposited with Deutschen Sammlung für Mikrorganismen und Zellkulturen (DSMZ, Braunschweig, Germany) in accordance with the Budapest Treaty:
Escherichia coli strain DH5α/pMC1 as DSM 22969
DETAILED DESCRIPTION OF THE INVENTION
The following examples will further illustrate this invention. The molecular biology techniques, e.g. plasmid DNA isolation, restriction enzyme treatment, ligations, standard transformations of Escherichia coli etc. used are, (unless stated otherwise), described by Sambrook et al., (Molecular Cloning. A Laboratory Manual (1989) Cold Spring Harbor Laboratories, USA).
EXAMPLE 1
Construction of a Gene Library of Corynebacterium glutamicum Strain AS019
A DNA library of Corynebacterium glutamicum strain ASO19 (Yoshihama et al., Journal of Bacteriology 162, 591-597 (1985)) was constructed using λ Zap Express™ system, (Short et al., (1988) Nucleic Acids Research, 16: 7583-7600), as described by O'Donohue (O'Donohue, M. (1997). The Cloning and Molecular Analysis of Four Common Aromatic Amino Acid Biosynthetic Genes from Corynebacterium glutamicum . Ph.D. Thesis, National University of Ireland, Galway). λ Zap Express™ kit was purchased from Stratagene (Stratagene, 11011 North Torrey Pines Rd., La Jolla, Calif. 92037) and used according to the manufacturer's instructions. AS019-DNA was digested with restriction enzyme Sau3A and ligated to BamHI treated and dephosphorylated λ Zap Express™ arms.
EXAMPLE 2
Cloning and Sequencing of the pgi Gene
1. Cloning
Escherichia coli strain DF1311, carrying mutations in the pgi and pgl genes as described by Kupor & Fraenkel, (Journal of Bacteriology 100: 1296-1301 (1969)), was transformed with approx. 500 ng of the AS019 λ Zap Express™ plasmid library described in Example 1. Selection for transformants was made on M9 minimal media, (Sambrook et al., (1989). Molecular Cloning. A Laboratory Manual Cold Spring Harbor Laboratories, USA), containing kanamycin at a concentration of 50 mg/l and incubation at 37° C. for 48 hours. Plasmid DNA was isolated from one transformant according to Birnboim & Doly (Nucleic Acids Research 7: 1513-1523 (1979)) and designated pAMC1 (FIG. 1 ).
2. Sequencing
For sequence analysis of the cloned insert of pAMC1 the method of Sanger et al. (Proceedings of the National Academy of Sciences USA 74, 5463-5467 (1977)) was applied using primers differentially labelled with a coloured fluorescent tag. It was carried out using the ABI prism 310 genetic analyser from Perkin Elmer Applied Biosystems, (Perkin Elmer Corporation, Norwalk, Conn., U.S.A), and the ABI prism Big Dye™ Terminator Cycle Sequencing Ready Reaction kit also from Perkin Elmer.
Initial sequence analysis was carried out using the universal forward and M13 reverse primers obtained from Pharnacia Biotech (St. Albans, Herts, AL1 3AW UK):
Universal forward primer: GTA ATA CGA CTC ACT ATA GGG C (SEQ ID NO:4)
M13 reverse primer: GGA AAC AGC TAT GAC CAT G (SEQ ID NO:5) Internal primers were subsequently designed from the sequence obtained which allowed the entire pgi gene to be deduced. The sequence of the internal primers is as follows:
Internal primer 1: GGA AAC AGG GGA GCC GTC (SEQ ID NO:6)
Internal primer 2: TGC TGA GAT ACC AGC GGT (SEQ ID NO:7)
Sequence obtained was then analysed using the DNA Strider program (Marck, (1988)). Nucleic Acids Research 16: 1829-1836), version 1.0 on an Apple Macintosh computer. This program allowed for analyses such as restriction site usage, open reading frame analysis and codon usage determination. Searches between DNA sequence obtained and those in EMBL and Genbank databases were achieved using the BLAST program, (Altschul et al., (1997). Nucleic Acids Research, 25: 3389-3402). DNA and protein sequences were aligned using the Clustal V and Clustal W programs (Higgins and Sharp, 1988 Gene 73: 237-244).
The sequence thus obtained is shown in SEQ ID NO 1. The analysis of the nucleotide sequence obtained revealed an open reading frame of 1650 base pairs which was designated as pgi gene. It codes for a protein of 550 amino acids shown in SEQ ID NO 2.
EXAMPLE 3
Mutagenesis of the pgi Gene
1. Construction of a pgi disruption vector
An internal segment of the pgi gene was amplified by polymerase chain reaction (PCR) using genomic DNA isolated from Corynebacterium glutamicum ASO19, (Heery & Dunican, (1993) Applied and Environmental Microbiology 59: 791-799), as template. The pgi primers used were:
fwd. Primer: ATG GAR WCC AAY GGH AA (SEQ ID NO:8)
rev. Primer: YTC CAC GCC CCA YTG RTC (SEQ ID NO:9)
with R=A+G; Y=C+T; W=A+T; H=A+T+C.
PCR Parameters were as follows:
35 cycles
94° C. for 1 min.
47° C. for 1 min.
72° C. for 30 sec.
1.5 mM MgCl 2
approx. 150-200 ng DNA template.
The PCR product obtained was cloned into the commercially available PGEM-T vector received from Promega Corp., (Promega UK, Southampton) using strain E. coli JM109, (Yanisch-Perron et al., 1985. Gene, 33: 103-119), as a host. The sequence of the PCR product is shown as SEQ ID No. 3. The cloned insert was then excised as an EcoRI fragment and ligated to plasmid pBGS8 (Spratt et al., Gene 41: 337-342 (1986)) pretreated with EcoRI. The restriction enzymes used were obtained from Boehringer Mannheim UK Ltd., (Bell Lane, Lewes, East Sussex BN7 1LG, UK) and used according to the manufacturer's instructions. E. coli JM109 was then transformed with this ligation mixture and electrotransformants were selected on Luria agar supplemented with IPTG (isopropyl-β-D-thiogalactopyranoside), XGAL (5-bromo-4-chloro-3-indolyl-D-galactopyranoside) and kanamycin at a concentration of 1 mM, 0.02% and 50 mg/l respectively. Agar plates were incubated for twelve hours at 37° C. Plasmid DNA was isolated from one transformant, characterised by restriction enzyme analysis using EcoRI, BamHI and SalI designated pMC1 (FIG. 2 ).
2. Insertion Mutagenesis of the pgi Gene in Strain DSM5715
Strain DSM 5715 was then transformed with plasmid pMC1 using the electroporation method described by Liebl et al. (FEMS Microbiology Letters, 53:299-303 (1989)).
Transformant selection proceeded on LBHIS agar consisting of 18.5 g/l of brain-heart infusion bouillon, 0.5 M sorbitol, 5 g/l of Bacto tryptone, 2.5 g/l of Bacto yeast extract, 5 g/l of NaCl and 18 g/l of Bacto agar, which had been supplemented with 15 mg/l of kanamycin and 1% fructose. Incubation was performed for 2 days at 33° C. Transformants 1, 2 and 3 were obtained.
The resultant transformants were were tested using the polymerase chain reaction (PCR). To this end, chromosomal DNA was isolated from the transformants obtained and from strain DSM5715 as described in Eikmanns et al. (Microbiology 140: 1817-1828 (1994)). The following primer oligonucleotides were selected for PCR on the basis of the DNA sequence of the pgi gene, which is shown in SEQ ID NO:1:
pgi-1: 5′ ACC CAC GCT GTC CTA CCT TA 3′ (SEQ ID NO:10)
pgi-2: 5′ TGT CCC AAA TCA CGC CCT AG 3′ (SEQ ID NO:11)
pgi-3: 5′ gat gat agc ggc cag tgc at 3′ (SEQ ID NO:12).
The primers shown were synthesised by the company MWG Biotech (Ebersberg, Germany) and the PCR reaction performed using the standard PCR method of Innis et al. (PCR-Protocols. A guide to methods and applications, 1990, Academic Press). The chromosomal DNA of the transformants was used as the template, and the chromosomal DNA of DSM5715 was used as the control. Each template was used in two PCR reactions, one with the primer pair pgi-1/pgi-2 and one with the primer pair pgi-1/pgi-3.
The PCR batches were separated by electrophoresis in a 0.8% agarose gel. Using primer pair pgi-1/pgi-2, each of the four PCR reactions yielded a DNA fragment of a length of 0.5 kb. Using primer pair pgi-1/pgi-3, only the control with DSM5715 DNA showed an amplification product of a length of 0.7 kb. No PCR product could be detected in the batches with chromosomal DNA from the transformants.
Transformant no. 3 characterised in this manner was named strain DSM5715:pMC1.
BRIEF DESCRIPTION OF THE DRAWINGS
The following Figures are attached:
FIG. 1 : Map of plasmid pAMC1.
FIG. 2 : Map of plasmid pMC1.
The abbreviations and names are defined as follows:
Neo r: Neomycin/kanamycin resistance
ColE1 ori: origin of replication of plasmid ColE1
CMV: Cytomegalovirus promoter
lacP: lactose promoter
pgi: phosphoglucose isomerase gene
lacZ: 5′-end of β-galactosidase gene
SV40 3′ splice: 3′ splice site of Simian Virus 40
SV40 polyA: polyadenylation site of Simian Virus 40
f1(−)ori: origin of replication of filamentous phage f1
SV40 ori: origin of replication of filamentous phage f1
kan r: kanamycin resistance
pgi insert: internal fragment of gene pgi
ori: origin of replication of plasmid pBGS8
AccI: cut site of restriction enzyme AccI
ApaI: cut site of restriction enzyme ApaI
BamHI: cut site of restriction enzyme BamHI
ClaI: cut site of restriction enzyme ClaI
DraI: cut site of restriction enzyme DraI
EcoRI: cut site of restriction enzyme EcoRI
HindIII: cut site of restriction enzyme HindIII
MluI: cut site of restriction enzyme MluI
MstII: cut site of restriction enzyme MstII
NheI: cut site of restriction enzyme NheI
NsiI: cut site of restriction enzyme NsiI
PstI: cut site of restriction enzyme PstI
PvuII: cut site of restriction enzyme PvuII
SacI: cut site of restriction enzyme SacI
SalI: cut site of restriction enzyme SalI
SmaI: cut site of restriction enzyme SmaI
SpeI: cut site of restriction enzyme SpeI
SspI: cut site of restriction enzyme SspI
12
1
2811
DNA
Corynebacterium glutamicum
CDS
(373)..(2022)
1
aaaacccgag gggcgaaaat tccaccctaa cttttttggg atcccctttt tccggggaat 60
taattggttt gggtttcaat gggaaaacgg gaaacaatgg gccaaaggtt caaaaacccc 120
aaaagggggc cgggttcaaa ttcccaaaaa aaatggcaaa aaaggggggg ccaaaaccaa 180
gttggccccc aaaccaccgg ggcaacggcc cacccacaaa ggggttgggt taaaggaagg 240
acgcccaaag taagcccgga atggcccacg ttcgaaaaag caggccccaa ttaaacgcac 300
cttaaatttg tcgtgtttcc cactttgaac actcttcgat gcgcttggcc acaaaagcaa 360
gctaacctga ag atg tta ttt aac gac aat aaa gga gtt ttc atg gcg gac 411
Met Leu Phe Asn Asp Asn Lys Gly Val Phe Met Ala Asp
1 5 10
att tcg acc acc cag gtt tgg caa gac ctg acc gat cat tac tca aac 459
Ile Ser Thr Thr Gln Val Trp Gln Asp Leu Thr Asp His Tyr Ser Asn
15 20 25
ttc cag gca acc act ctg cgt gaa ctt ttc aag gaa gaa aac cgc gcc 507
Phe Gln Ala Thr Thr Leu Arg Glu Leu Phe Lys Glu Glu Asn Arg Ala
30 35 40 45
gag aag tac acc ttc tcc gcg gct ggc ctc cac gtc gac ctg tcg aag 555
Glu Lys Tyr Thr Phe Ser Ala Ala Gly Leu His Val Asp Leu Ser Lys
50 55 60
aat ctg ctt gac gac gcc acc ctc acc aag ctc ctt gca ctg acc gaa 603
Asn Leu Leu Asp Asp Ala Thr Leu Thr Lys Leu Leu Ala Leu Thr Glu
65 70 75
gaa tct ggc ctt cgc gaa cgc att gac gcg atg ttt gcc ggt gaa cac 651
Glu Ser Gly Leu Arg Glu Arg Ile Asp Ala Met Phe Ala Gly Glu His
80 85 90
ctc aac aac acc gaa gac cgc gct gtc ctc cac acc gcg ctg cgc ctt 699
Leu Asn Asn Thr Glu Asp Arg Ala Val Leu His Thr Ala Leu Arg Leu
95 100 105
cct gcc gaa gct gat ctg tca gta gat ggc caa gat gtt gct gct gat 747
Pro Ala Glu Ala Asp Leu Ser Val Asp Gly Gln Asp Val Ala Ala Asp
110 115 120 125
gtc cac gaa gtt ttg gga cgc atg cgt gac ttc gct act gcg ctg cgc 795
Val His Glu Val Leu Gly Arg Met Arg Asp Phe Ala Thr Ala Leu Arg
130 135 140
tca ggc aac tgg ttg gga cac acc ggc cac acg atc aag aag atc gtc 843
Ser Gly Asn Trp Leu Gly His Thr Gly His Thr Ile Lys Lys Ile Val
145 150 155
aac att ggt atc ggt ggc tct gac ctc gga cca gcc atg gct acg aag 891
Asn Ile Gly Ile Gly Gly Ser Asp Leu Gly Pro Ala Met Ala Thr Lys
160 165 170
gct ctg cgt gca tac gcg acc gct ggt atc tca gca gaa ttc gtc tcc 939
Ala Leu Arg Ala Tyr Ala Thr Ala Gly Ile Ser Ala Glu Phe Val Ser
175 180 185
aac gtc gac cca gca gac ctc gtt tct gtg ttg gaa gac ctc gat gca 987
Asn Val Asp Pro Ala Asp Leu Val Ser Val Leu Glu Asp Leu Asp Ala
190 195 200 205
gaa tcc aca ttg ttc gtg atc gct tcg aaa act ttc acc acc cag gag 1035
Glu Ser Thr Leu Phe Val Ile Ala Ser Lys Thr Phe Thr Thr Gln Glu
210 215 220
acg ctg tcc aac gct cgt gca gct cgt gct tgg ctg gta gag aag ctc 1083
Thr Leu Ser Asn Ala Arg Ala Ala Arg Ala Trp Leu Val Glu Lys Leu
225 230 235
ggt gaa gag gct gtc gcg aag cac ttc gtc gca gtg tcc acc aat gct 1131
Gly Glu Glu Ala Val Ala Lys His Phe Val Ala Val Ser Thr Asn Ala
240 245 250
gaa aag gtc gca gag ttc ggt atc gac acg gac aac atg ttc ggc ttc 1179
Glu Lys Val Ala Glu Phe Gly Ile Asp Thr Asp Asn Met Phe Gly Phe
255 260 265
tgg gac tgg gtc gga ggt cgt tac tcc gtg gac tcc gca gtt ggt ctt 1227
Trp Asp Trp Val Gly Gly Arg Tyr Ser Val Asp Ser Ala Val Gly Leu
270 275 280 285
tcc ctc atg gca gtg atc ggc cct cgc gac ttc atg cgt ttc ctc ggt 1275
Ser Leu Met Ala Val Ile Gly Pro Arg Asp Phe Met Arg Phe Leu Gly
290 295 300
gga ttc cac gcg atg gat gaa cac ttc cgc acc acc aag ttc gaa gag 1323
Gly Phe His Ala Met Asp Glu His Phe Arg Thr Thr Lys Phe Glu Glu
305 310 315
aac gtt cca atc ttg atg gct ctg ctc ggt gtc tgg tac tcc gat ttc 1371
Asn Val Pro Ile Leu Met Ala Leu Leu Gly Val Trp Tyr Ser Asp Phe
320 325 330
tat ggt gca gaa acc cac gct gtc cta cct tat tcc gag gat ctc agc 1419
Tyr Gly Ala Glu Thr His Ala Val Leu Pro Tyr Ser Glu Asp Leu Ser
335 340 345
cgt ttt gct gct tac ctc cag cag ctg acc atg gag acc aat ggc aag 1467
Arg Phe Ala Ala Tyr Leu Gln Gln Leu Thr Met Glu Thr Asn Gly Lys
350 355 360 365
tca gtc cac cgc gac ggc tcc cct gtt tcc act ggc act ggc gaa att 1515
Ser Val His Arg Asp Gly Ser Pro Val Ser Thr Gly Thr Gly Glu Ile
370 375 380
tac tgg ggt gag cct ggc aca aat ggc cag cac gct ttc ttc cag ctg 1563
Tyr Trp Gly Glu Pro Gly Thr Asn Gly Gln His Ala Phe Phe Gln Leu
385 390 395
atc cac cag ggc act cgc ctt gtt cca gct gat ttc att ggt ttc gct 1611
Ile His Gln Gly Thr Arg Leu Val Pro Ala Asp Phe Ile Gly Phe Ala
400 405 410
cgt cca aag cag gat ctt cct gcc ggt gag cgc acc atg cat gac ctt 1659
Arg Pro Lys Gln Asp Leu Pro Ala Gly Glu Arg Thr Met His Asp Leu
415 420 425
ttg atg agc aac ttc ttc gca cag acc aag gtt ttg gct ttc ggt aag 1707
Leu Met Ser Asn Phe Phe Ala Gln Thr Lys Val Leu Ala Phe Gly Lys
430 435 440 445
aac gct gaa gag atc gct gcg gaa ggt gtc gca cct gag ctg gtc aac 1755
Asn Ala Glu Glu Ile Ala Ala Glu Gly Val Ala Pro Glu Leu Val Asn
450 455 460
cac aag gtc gtg cca ggt aat cgc cca acc acc acc att ttg gcg gag 1803
His Lys Val Val Pro Gly Asn Arg Pro Thr Thr Thr Ile Leu Ala Glu
465 470 475
gaa ctt acc cct tct att ctc ggt gcg ttg atc gct ttg tac gaa cac 1851
Glu Leu Thr Pro Ser Ile Leu Gly Ala Leu Ile Ala Leu Tyr Glu His
480 485 490
acc gtg atg gtt cag ggc gtg att tgg gac atc aac tcc ttc gac caa 1899
Thr Val Met Val Gln Gly Val Ile Trp Asp Ile Asn Ser Phe Asp Gln
495 500 505
tgg ggt gtt gaa ctg ggc aaa cag cag gca aat gac ctc gct ccg gct 1947
Trp Gly Val Glu Leu Gly Lys Gln Gln Ala Asn Asp Leu Ala Pro Ala
510 515 520 525
gtc tct ggt gaa gag gat gtt gac tcg gga gat tct tcc act gat tca 1995
Val Ser Gly Glu Glu Asp Val Asp Ser Gly Asp Ser Ser Thr Asp Ser
530 535 540
ctg att aag tgg tac cgc gca aat agg tagtcgcttg cttatagggt 2042
Leu Ile Lys Trp Tyr Arg Ala Asn Arg
545 550
caggggcgtg aagaatcctc gcctcatagc actggccgct atcatcctga cctcgttcaa 2102
tctgcgaaca gctattactg ctttagctcc gctggtttct gagattcggg atgatttagg 2162
ggttagtgct tctcttattg gtgtgttggg catgatcccg actgctatgt tcgcggttgc 2222
tgcgtttgcg cttccgtcgt tgaagaggaa gttcactact tcccaactgt tgatgtttgc 2282
catgctgttg actgctgccg gtcagattat tcgtgtcgct ggacctgctt cgctgttgat 2342
ggtcggtact gtgttcgcga tgtttgcgat cggagttacc aatgtgttgc ttccgattgc 2402
tgttagggag tattttccgc gtcacgtcgg tggaatgtcg acaacttatc tggtgtcgtt 2462
ccagattgtt caggcacttg ctccgacgct tgccgtgccg atttctcagt gggctacaca 2522
tgtggggttg accggttgga gggtgtcgct cggttcgtgg gcgctgctgg ggttggttgc 2582
ggcgatttcg tggattccgc tgttgagttt gcagggtgcc agggttgttg cggcgccgtc 2642
gaaggtttct cttcctgtgt ggaagtcttc ggttggtgtg gggctcgggt tgatgtttgg 2702
gtttacttcg tttgcgacgt atatcctcat gggttttatg ccgcagatgg taggtgatcc 2762
aaagaattca aaaagcttct cgagagtact tctagagcgg ccgcgggcc 2811
2
550
PRT
Corynebacterium glutamicum
2
Met Leu Phe Asn Asp Asn Lys Gly Val Phe Met Ala Asp Ile Ser Thr
1 5 10 15
Thr Gln Val Trp Gln Asp Leu Thr Asp His Tyr Ser Asn Phe Gln Ala
20 25 30
Thr Thr Leu Arg Glu Leu Phe Lys Glu Glu Asn Arg Ala Glu Lys Tyr
35 40 45
Thr Phe Ser Ala Ala Gly Leu His Val Asp Leu Ser Lys Asn Leu Leu
50 55 60
Asp Asp Ala Thr Leu Thr Lys Leu Leu Ala Leu Thr Glu Glu Ser Gly
65 70 75 80
Leu Arg Glu Arg Ile Asp Ala Met Phe Ala Gly Glu His Leu Asn Asn
85 90 95
Thr Glu Asp Arg Ala Val Leu His Thr Ala Leu Arg Leu Pro Ala Glu
100 105 110
Ala Asp Leu Ser Val Asp Gly Gln Asp Val Ala Ala Asp Val His Glu
115 120 125
Val Leu Gly Arg Met Arg Asp Phe Ala Thr Ala Leu Arg Ser Gly Asn
130 135 140
Trp Leu Gly His Thr Gly His Thr Ile Lys Lys Ile Val Asn Ile Gly
145 150 155 160
Ile Gly Gly Ser Asp Leu Gly Pro Ala Met Ala Thr Lys Ala Leu Arg
165 170 175
Ala Tyr Ala Thr Ala Gly Ile Ser Ala Glu Phe Val Ser Asn Val Asp
180 185 190
Pro Ala Asp Leu Val Ser Val Leu Glu Asp Leu Asp Ala Glu Ser Thr
195 200 205
Leu Phe Val Ile Ala Ser Lys Thr Phe Thr Thr Gln Glu Thr Leu Ser
210 215 220
Asn Ala Arg Ala Ala Arg Ala Trp Leu Val Glu Lys Leu Gly Glu Glu
225 230 235 240
Ala Val Ala Lys His Phe Val Ala Val Ser Thr Asn Ala Glu Lys Val
245 250 255
Ala Glu Phe Gly Ile Asp Thr Asp Asn Met Phe Gly Phe Trp Asp Trp
260 265 270
Val Gly Gly Arg Tyr Ser Val Asp Ser Ala Val Gly Leu Ser Leu Met
275 280 285
Ala Val Ile Gly Pro Arg Asp Phe Met Arg Phe Leu Gly Gly Phe His
290 295 300
Ala Met Asp Glu His Phe Arg Thr Thr Lys Phe Glu Glu Asn Val Pro
305 310 315 320
Ile Leu Met Ala Leu Leu Gly Val Trp Tyr Ser Asp Phe Tyr Gly Ala
325 330 335
Glu Thr His Ala Val Leu Pro Tyr Ser Glu Asp Leu Ser Arg Phe Ala
340 345 350
Ala Tyr Leu Gln Gln Leu Thr Met Glu Thr Asn Gly Lys Ser Val His
355 360 365
Arg Asp Gly Ser Pro Val Ser Thr Gly Thr Gly Glu Ile Tyr Trp Gly
370 375 380
Glu Pro Gly Thr Asn Gly Gln His Ala Phe Phe Gln Leu Ile His Gln
385 390 395 400
Gly Thr Arg Leu Val Pro Ala Asp Phe Ile Gly Phe Ala Arg Pro Lys
405 410 415
Gln Asp Leu Pro Ala Gly Glu Arg Thr Met His Asp Leu Leu Met Ser
420 425 430
Asn Phe Phe Ala Gln Thr Lys Val Leu Ala Phe Gly Lys Asn Ala Glu
435 440 445
Glu Ile Ala Ala Glu Gly Val Ala Pro Glu Leu Val Asn His Lys Val
450 455 460
Val Pro Gly Asn Arg Pro Thr Thr Thr Ile Leu Ala Glu Glu Leu Thr
465 470 475 480
Pro Ser Ile Leu Gly Ala Leu Ile Ala Leu Tyr Glu His Thr Val Met
485 490 495
Val Gln Gly Val Ile Trp Asp Ile Asn Ser Phe Asp Gln Trp Gly Val
500 505 510
Glu Leu Gly Lys Gln Gln Ala Asn Asp Leu Ala Pro Ala Val Ser Gly
515 520 525
Glu Glu Asp Val Asp Ser Gly Asp Ser Ser Thr Asp Ser Leu Ile Lys
530 535 540
Trp Tyr Arg Ala Asn Arg
545 550
3
462
DNA
Corynebacterium glutamicum
3
atggagacca atggcaagtc agtccaccgc gacggctccc ctgtttccac tggcactggc 60
gaaatttact ggggtgagcc tggcacaaat ggccagcacg ctttcttcca gctgatccac 120
cagggcactc gccttgttcc agctgatttc attggtttcg ctcgtccaaa gcaggatctt 180
cctgccggtg agcgcaccat gcatgacctt ttgatgagca acttcttcgc acagaccaag 240
gttttggctt tcggtaagaa cgctgaagag atcgctgcgg aaggtgtcgc acctgagctg 300
gtcaaccaca aggtcgtgcc aggtaatcgc ccaaccacca ccattttggc ggaggaactt 360
accccttcta ttctcggtgc gttgatcgct ttgtacgaac acaccgtgat ggttcagggc 420
gtgatttggg acatcaactc cttcgaccaa tggggcgtgg aa 462
4
22
DNA
Artificial Sequence
Description of Artificial Sequence Universal
forward primer
4
gtaatacgac tcactatagg gc 22
5
19
DNA
Artificial Sequence
Description of Artificial Sequence M13 reverse
primer
5
ggaaacagct atgaccatg 19
6
18
DNA
Corynebacterium glutamicum
Internal Primer 1
6
ggaaacaggg gagccgtc 18
7
18
DNA
Corynebacterium glutamicum
Internal primer 2
7
tgctgagata ccagcggt 18
8
17
DNA
Artificial Sequence
Description of Artificial Sequence fwd. primer
8
atggarwcca aygghaa 17
9
18
DNA
Artificial Sequence
Description of Artificial Sequence rev. primer
9
ytccacgccc caytgrtc 18
10
20
DNA
Corynebacterium glutamicum
Primer pgi-1
10
acccacgctg tcctacctta 20
11
20
DNA
Corynebacterium glutamicum
Primer pgi-2
11
tgtcccaaat cacgccctag 20
12
20
DNA
Corynebacterium glutamicum
Primer pgi-2
12
gatgatagcg gccagtgcat 20 | The present invention is directed to isolated polynucleotides coding for phosphoglucose isomerase (pgi) from coryneform bacteria. In addition, the invention includes methods for increasing the metabolic flux through pentose phosphate cycle of bacteria by reducing or eliminating the activity of pgi. These methods may be used to increase the fermentative production of nucleotides, vitamins and amino acids. | 2 |
CROSS REFERENCE TO RELATED APPLICATIONS
[0001] The present application is a continuation in part of U.S. patent application Ser. No. 13/217,683 entitled “Automatic Door Closer”, filed on Aug. 25, 2011, which claimed priority to U.S. provisional patent application 61/379,347 entitled “Automatic Door Closer”, filed Sep. 1, 2010, the entirety of which are incorporated herein by reference for all purposes.
BACKGROUND
[0002] Power or automatic door openers and/or closers, such a garage door openers/closers, open and close their respective doors at the press of a button. In some situations, a door can be inadvertently left open, which can be a security risk. Therefore, it is generally important to verify that the door has been fully closed when the area of the door is going to be left unattended. Checking the status of the door can be difficult when multiple people have access to the door, such as children who may not remember to close it. Furthermore, doors may be temporarily left fully or partially open for venting or other purposes, requiring the user to remember to close them at a later time.
SUMMARY
[0003] Control devices that operate automatic door controllers and methods of operating automatic door controllers are disclosed. An embodiment of controller control device that operates with an automatic door closer includes a sensor that is attached to the door, the sensor operable to transmit data indicative of the orientation of the door. The controller also includes a receiver that is operable to receive the data from the sensor; monitor the orientation of the door based on the data received from the sensor; transmit a door closing instruction to the automatic door closer when the door orientation has been open for a first period; and pause the transmitting of door closing information to the automatic door closer for a second period when a pause input is received from a user.
BRIEF DESCRIPTION OF THE DRAWINGS
[0004] A further understanding of the various embodiments of the present invention may be realized by reference to the figures which are described in remaining portions of the specification. In the figures, like reference numerals may be used throughout several drawings to refer to similar components.
[0005] FIG. 1 depicts a block diagram of a wirelessly coupled transmitter and receiver in an automatic door closer in accordance with some embodiments of the present invention;
[0006] FIG. 2 depicts an overhead door with transmitter mounted thereon in accordance with some embodiments of the present invention;
[0007] FIGS. 3A and 3B depict front and back views, respectively, of an existing garage door switch connected to an automatic door closer receiver in accordance with some embodiments of the present invention;
[0008] FIGS. 4A and 4B depict front and back views, respectively, of another existing garage door switch connected to an automatic door closer receiver in accordance with some embodiments of the present invention;
[0009] FIG. 5 depicts an embodiment of a receiver of FIG. 2 showing the user interface;
[0010] FIG. 6 depicts a flowchart of an example operation for determining and transmitting a door status in accordance with some embodiments of the present invention;
[0011] FIG. 7 depicts a flowchart of an example operation for automatically closing a door in accordance with some embodiments of the present invention;
[0012] FIG. 8 depicts a block diagram of a receiver portion of an automatic door closer in accordance with some embodiments of the present invention; and
[0013] FIG. 9 depicts a block diagram of a transmitter portion of an automatic door closer in accordance with some embodiments of the present invention.
DETAILED DESCRIPTION
[0014] The drawings and description, in general, disclose various embodiments of a control device for controlling an automatic door opener/closer. The door opener/closer is sometimes referred to herein simply as the garage door closer or a mechanical device that changes the orientation of a door. The control device may include a sensor and transmitter mounted to a door, such as an overhead door, and a receiver connected to a garage door closer. The control device causes the door closer to automatically close the door after a delay. The delay may be paused for a period by a user on a one-time basis. For example, the control device may be set to automatically close the door if the door is ever open for a period of fifteen minutes. However, there may be one-time situations where the door needs to stay open for a long period of time, wherein after the long period, the door is to be closed after the above-described delay. The user may instruct the control device to pause the automatic door closing for a period, such as eight hours, after which, the control device will resume the process of closing the door after it has been left open for the delay period.
[0015] The control device can be easily connected to existing door closers such as conventional garage door openers/closers. In some embodiments, the receiver is connected to a garage door opener button or switch and draws power from the wiring to the button, so that power is maintained to the control device even when the garage door opener button is pressed.
[0016] The term “door closer” is used broadly herein to refer to any powered door opener and/or closer, and does not imply that the control device is limited to use on the door of a garage. Rather, the control device may be used with any overhead door or other door to which a sensor can be attached to detect whether the door is open or closed, and which can be automatically closed by the automatic door closer.
[0017] Turning now to FIG. 1 , the control device 10 includes a transmitter 12 , which is attached to the door to be monitored and closed, and a receiver 14 that may be connected to a door closer (not shown). The transmitter 12 and receiver 14 are in wireless communication using a radio frequency (RF) link 16 or other type of wireless connection. The transmitter 12 includes a position sensor 20 that detects the position of the door to which it is attached. The sensor 20 may comprise any suitable sensor for detecting the position or orientation of the door, such as a mercury switch, accelerometer, mechanical switch, proximity sensor, RFID, RF, RSSI, ball bearing tilt sensor, magnetic reed switch, optical or inductive sensors, ultrasonic sensors, infrared transmitter/receivers, etc.
[0018] In some embodiments, the transmitter 12 includes a microcontroller 22 that controls the operation of the transmitter 12 and that may read position information from the sensor 20 either periodically or continuously. The microcontroller 22 transmits door position or orientation information to the receiver 14 using an RF link 24 in the transmitter 12 , or any other suitable wireless link. The sensor 20 , microcontroller 22 and RF link 24 are powered by a power source 26 such as a battery. Power status in the transmitter 12 may be reported to users, for example by transmitting power status to the receiver 14 for display, or by displaying power status on the transmitter 12 with a status light-emitting diode (LED) or other display device (not shown in FIG. 1 ). The microcontroller 22 is replaced in some embodiments of the transmitter 12 by other devices such as a state machine, application specific integrated circuit (ASIC), programmable gate array (PGA), discrete logic circuits, etc.
[0019] Some embodiments of the receiver 14 includes a microcontroller 30 to control the operation of the receiver 14 . In other embodiments, the microcontroller 30 is replaced by other devices such as a state machine, discrete logic circuits, etc. The microcontroller 30 in the receiver 14 communicates with the transmitter 12 using an RF link 32 to obtain door position or orientation information. As described above, the power status of the transmitter 12 may be transmitted to the receiver 14 where it is processed by the microcontroller 30 . The microcontroller 30 automatically causes the door closer to close the door according to a number of control schemes, which are referred to as closing the door. For example, in some embodiments, the microcontroller 30 causes the door closer to close the door after a user-selected delay and if the transmitter 12 reports that the door is not fully closed. The microcontroller 30 also provides a user interface 34 in the receiver 14 that controls input devices, such as pushbuttons, and displays information on display devices, such as LEDs.
[0020] In some embodiments, the microcontroller 30 , RF link 32 and user interface 34 draw power from a power harness circuit 36 connected to a garage door button interface 40 . When the switch in the garage door button interface 40 is not being pressed by a user, a voltage potential appears across the terminals of the switch, and the power harness circuit 36 draws power from this voltage potential. The power harness circuit 36 also stores power so that when the switch in the garage door button interface 40 is closed and the voltage potential drops momentarily, the power harness circuit 36 is able to continue to power the receiver 14 . In other embodiments, the receiver 14 is powered from other sources such as a battery or an external power supply.
[0021] During operation, the microcontroller 30 monitors the door position as reported by the transmitter 12 and processes data from the user interface 34 . If the user interface 34 is programmed to close the door, and the transmitter 12 reports that the door is not closed, the microcontroller 30 causes the door to close by actuating the garage door button interface 40 . For example, the door closer may be designed to cause the door to close by pressing a button to create an electrical connection between two terminals. In such embodiments, the garage door button interface 40 is connected across the two terminals, and the microcontroller 30 causes the door to close by creating an electrical connection between the two terminals in the garage door button interface 40 .
[0022] Reference is made to FIG. 2 , which illustrates a garage door, sometimes referred to as an overhead door or simply a door 50 , on which the transmitter 12 may be mounted. In this example, the door 50 is made of a number of horizontal panels (e.g., 52 ), with the transmitter 12 mounted to the top panel 52 . The top panel 52 is in the fully vertical position only when the door 50 is closed, otherwise, the top panel 52 will be in an angled or horizontal orientation. In this embodiment, the sensor 20 is adapted to detect when the top panel 52 to which it is attached is in the fully vertical position or not. If the top panel 52 is not fully vertical, then the door 50 is open or partially open. The transmitter 12 may be attached to the door 50 in any suitable manner, such as with screws, double sided tape, adhesives, etc.
[0023] Turning now to FIGS. 3A and 3B , an example of an existing single-button garage door closer unit 60 is illustrated in front view ( FIG. 3A ) and rear view ( FIG. 3B ). The unit 60 has a push button 62 which is pressed by a user to open and close the door. The unit 60 may also include one or more mounting holes 64 and 66 or other attachment devices. A pair of electrical terminals 70 and 72 , such as screws, are located on the unit 60 and may be located in the back of the unit 60 . Wires 74 and 76 are connected to the terminals 70 and 72 . The wires 74 , 76 are used to send a signal, such as an open or close signal to the door closer (not shown). When the user presses the button 62 , the unit 60 shorts across and electrically connects the terminals 70 and 72 , which causes a signal to be sent to the door closer.
[0024] The receiver 14 , FIG. 1 , is connected to the unit 60 by an electrical cable 84 , with one wire 80 in the cable 84 being connected to one of the terminals 70 and the other wire 82 being connected to the other terminal 72 . The receiver 14 causes the door to close by shorting across the terminals 70 and 72 , mimicking a manual press of the button 62 .
[0025] In one embodiment of the installation of the receiver 14 , the unit 60 is removed, and the wires 74 and 76 are loosened. The wires 80 and 82 from the receiver 14 , FIG. 1 , are connected to the terminals 70 and 72 , and the terminals 70 and 72 are re-tightened with both the original wires 74 and 76 and new wires 80 and 82 from the receiver 14 . The receiver 14 may be installed in addition to the existing unit 60 so that they are connected in parallel. Proper polarity of the wires 80 and 82 may be indicated by color-coding, for example using a red wire (e.g., 80 ) to be connected to the positive terminal 70 of the unit 60 (commonly brass, or gold colored), and using a black wire to be connected to the negative terminal 72 of the garage door opener switch 60 (commonly silver).
[0026] The description herein generically refers to closing the door 50 , FIG. 2 , by actuating the unit 60 using the receiver 14 . It is important to note that the receiver 14 cause the door closer to activate by shorting the terminals 70 , 72 after a pre-determined amount of time or according to other control schemes. Therefore, if the door 50 is open or partially open, the direction of travel of the door 50 is determined by the door closer. Some door closer models allow the door to be left partially open in either direction. Other models will only allow the door to be left partially open when the door was previously opening or traveling in the up direction. In some embodiments of the control device 10 , if the receiver 14 activates the door closer and the door 50 opens instead of closes, the control device 10 will re-activate and close the door 50 within a predetermined period, such as 1 minute, because it still senses that the door 50 is open.
[0027] Reference is made to FIGS. 4A and 4B which show front and back plan views of different embodiments of an existing garage door opener unit 110 . The unit 110 may include a multi-function switch with multiple buttons and indicators. In the embodiment of FIG. 4 , the unit 100 includes a single switch 112 , which is a push button switch, and a single indicator 114 . The connection to the receiver 14 is similar to the embodiment of FIGS. 3A and 3B . The unit 110 is removed from the wall, exposing a circuit board or other access panel 116 , and the wires 74 and 76 that control the door 50 being monitored are loosened. The wires 80 and 82 from the receiver 14 are connected to the terminals 70 and 72 , and the terminals 70 and 72 are re-tightened with both the original wires 74 and 76 and new wires 80 and 82 from the receiver 14 . It follows that the receiver 14 is electrically connected in parallel with the unit 110 . In some embodiments, the above-described connection causes the receiver 14 to be connected in parallel with the switch 112 .
[0028] The receiver 14 may be installed in addition to and/or adjacent the existing unit 110 . Again, proper polarity of the wires 80 and 82 may be indicated by color-coding, for example using a red wire (e.g., 80 ) to be connected to the positive terminal 70 of the unit 110 (commonly brass, or gold colored), and using a black wire to be connected to the negative terminal 72 of the unit 110 (commonly silver). Using the proper polarity enables the receiver 14 to draw power from the wires 74 , 76 . The unit 110 may then be reattached as it was before the connection to the receiver 14 .
[0029] An example user interface 34 on the receiver 14 is illustrated in FIG. 5 . The user interface 34 includes a plurality of delay buttons 132 , a pause button 134 , and an off button 136 . The above-described buttons may be push-type switches that open or close a circuit upon being pressed. The delay buttons 132 activate the amount of time that the receiver 14 waits before it cause the door 50 , FIG. 2 , to close. In the embodiment of FIG. 4 , there are three delays that a user may select, one minute, five minutes, and fifteen minutes. The pause button 134 activates a one-time pause that pauses the door closing procedures. More specifically, the transmission of signals to close the door 50 that are transmitted from the receiver 14 are paused when the pause button 134 is activated. The off button causes the receiver 14 to turn off.
[0030] In addition to the switches described above, the user interface 130 may have a plurality of lights or indicators 140 , such as light-emitting diodes (LEDs). The delay buttons 132 are each associated with a delay indicator 140 . The delay indicators 140 provide the user information as to how long of a delay will occur before the receiver 14 transmits a signal to the door closer causing the door to close. The pause switch 134 is associated with a pause indicator 142 . The pause indicator 142 provides the user with information regarding the status of the pause function. If the pause indicator 142 is illuminated, the pause feature may be active so that the delays occur after the time set by the pause function. After the one-time pause, the receiver 14 may return to closing the door 50 after the delay has expired.
[0031] As described above, the receiver 14 also includes an off indicator 144 . The off indicator may illuminate when the receiver 14 has been turned off. As described above, the receiver 14 may receive power from the door closer, so leaving the off indicator 144 illuminated will not adversely affect the receiver 14 . The receiver of FIG. 5 includes a low battery indicator 146 , that provides an indication when the battery 26 in the transmitter 12 , FIG. 2 , is low.
[0032] It is noted that the user interface 34 is not limited to the example activation time delays or even to the use of fixed discrete activation time delays. The user interface 34 may be adapted to allow specific time delays to be programmed, or to use triggering events other than elapsed time delays, such as time of day. Furthermore, the control device 10 may include any suitable interface, including keypads, rotary switches, slide switches, toggle switches, touch sensitive screens, text or graphical displays, remote control such as using a computer, cellular telephone or other devices, etc.
[0033] Having described the components of the control device 10 , FIG. 1 , the operation of the transmitter 12 and receiver 14 will now be described. Reference is made to FIG. 6 , which is a flow chart illustrating the operation of an embodiment of the transmitter 12 . In this embodiment, the microcontroller 22 in the transmitter 12 includes a watchdog timer that resets the microcontroller 22 if the watchdog timer is not cleared before it reaches a predetermined value. In this embodiment, the operation of the transmitter 12 includes periodically clearing the watchdog timer as described in step 150 . The position sensor 20 is read at step 152 by the microcontroller 22 . At step 154 , the position or orientation information received from the position sensor 20 is transmitted to the receiver 14 . The transmission may be by wireless communications, such as the use of a RF signal using the RF link 16 . The RF signal may include a packet that includes a range of data, including for example, a door open or closed indication, and a low battery indicator. In one embodiment, the RF link 16 is address-based, with the transmitter 12 using the receiver 14 address to send the RF packet and with the receiver 14 responding to acknowledge receipt of the RF packet. The microcontroller 30 is then placed in a sleep mode to conserve power at step 156 until the process repeats. For example, in one embodiment, the microcontroller 30 is placed in the sleep mode for about eight seconds. Therefore, the door position data and other data is read and reported every eight seconds.
[0034] Reference is made to FIG. 7 , which is a flow chart illustrating the operation of one embodiment of the receiver 14 . As with the transmitter 12 , a watchdog timer in the microcontroller 30 is cleared at step 380 . Data, such as RF packets, from the transmitter 12 are serviced at step 382 by acknowledging the packets to the transmitter 12 and reading the information contained in the packets. The data in the packets may include information such as the orientation of the door 50 and the status of a battery located in the transmitter 12 .
[0035] In step 384 the delay as set by the switches 132 , FIG. 5 , is determined. In the embodiments described herein, there are three possible delays, one minute, five minutes, and fifteen minutes. It is noted that the delay may only be determined if the door 50 is determined to be open. Processing proceeds to decision block 386 where a determination is made as to whether the pause has been initiated. As described above, the pause is initiated by the user pressing the pause switch 134 . If the pause has been initiated, a one-time pause is initiated, which keeps the door 50 open for the time set by the pause. In some embodiments, the pause is eight hours. After the pause period, normal operation of the receiver 14 works by closing the door 50 after the delay period set by the switches 134 . If the decision of decision block 386 is affirmative, processing proceeds to step 388 and paused for the time of the pause. In some embodiments, the delay time is processed after the pause time. For example, if the delay is one minute and the pause set for a period of eight hours, the total time that the door will be open is eight hours and one minute. If the decision of decision block 386 is negative, processing proceeds to step 390 where processing is delayed for the amount of time set by the switches 132 . It is noted that the delay is automatic and the pause is a one-time function set each time by the user.
[0036] Processing from both step 388 and 390 proceeds to step 392 where a determination is made as to whether the door 50 has been closed. In some situations, the door 50 may have been closed during the delay or the pause. For example, a use may have closed the door during the delay and/or pause period. If a signal is sent to the door closer and the door 50 is closed, the closed door 50 may open. By assuring that the door 50 is open, initiating the switch 62 will cause the door 50 to close. If the door 50 is closed, processing returns to step 380 . If the door 50 is open, processing proceeds to step 394 where a signal is sent to close the door 50 . After the door 50 has closed, processing returns to step 380 .
[0037] Reference is made to FIG. 8 , which is a schematic illustration of an embodiment of the receiver 14 in the automatic door closer 10 . The microcontroller 30 and other active devices in the receiver 14 are powered in this embodiment by the power harness circuit 36 . The power harness circuit 36 in the receiver 14 is connected to the existing garage door opener switch 60 , FIG. 3B , or 110 , FIG. 4B , through a two lead input 200 , one lead of which is used as a voltage input 202 and the other lead is used as ground 204 . The voltage input 202 is connected to a voltage regulator 206 through a diode 210 . The output of the voltage regulator 206 is connected to a super-capacitor 212 (or other power storage device) through another diode 214 . When the button (e.g., 62 ) is pressed, the diode 214 prevents current from flowing from the super-capacitor 212 back toward the input 200 , maintaining power in the receiver 14 when the voltage input 202 is grounded through the button (e.g., 62 ). A transient voltage suppressor 216 may be connected to the voltage input 202 to protect the receiver 14 against voltage transients. Additional voltage regulators may be included as desired to provide multiple voltage levels in the receiver 14 .
[0038] A switch 220 such as a Darlington transistor, MOSFET transistor or any other suitable switch is connected between the microcontroller 30 and the voltage input 202 , enabling the microcontroller 30 to short the voltage input 202 to ground 204 to activate the garage door opener and close the overhead door 50 . A polyswitch 222 may be connected between the switch 220 and the voltage input 202 , providing overcurrent protection to the switch 220 . The polyswitch 222 allows current to flow through the switch 220 until a current limit is reached, when the resistance of the polyswitch 222 increases and limits the current through the switch 220 . Once the microcontroller 30 turns off the switch 220 and the polyswitch 222 cools, the resistance of the polyswitch 222 resets and returns to a normal low value. In other embodiments, a resistor or other device can be used to limit current through the switch 220 , as long as it is high enough to trigger the garage door opener.
[0039] A feedback signal 224 from the voltage input 202 can be connected to the microcontroller 30 , enabling the microcontroller 30 to detect when the button 62 in the garage door opener switch 60 is pressed by a user. The feedback signal 224 may pass through a resistor 226 to limit current if desired. The user interface 34 may be adapted for example to reset a timer in the microcontroller 30 when the user presses the button 62 , starting the countdown to the activation time delay over.
[0040] A program port 230 may also be connected to the microcontroller 30 , providing external access to change or update firmware in the microcontroller 30 . Any suitable interface may be provided for the program port 230 , based on the specific microcontroller 30 selected.
[0041] The RF link 32 connected to the microcontroller 30 may include a radio transceiver 234 and antenna 236 , or other devices suitable for transmitting and receiving information on the RF link 16 , FIG. 1 . The wireless protocol for the RF link 32 may be handled internally in the microcontroller 30 or in an external RF device as desired. Although the RF link 32 in the receiver 14 primarily receives information from the transmitter 12 , it may also transmit information to establish communication with the transmitter 12 according to the wireless protocol selected. Again, additional regulators may be included in the receiver 14 as needed to provide different voltage levels, for example if the microcontroller 30 and the transceiver 234 operate at different voltages.
[0042] Output devices such as the LEDs 140 - 146 and an audio device 240 are also connected to the microcontroller 30 , enabling the microcontroller 30 to implement the user interface 34 , FIG. 5 , and provide information to the user as described above. Again, the receiver 14 is not limited to the example described herein, and may use alternate switching devices, power sources, controlling circuitry, etc.
[0043] Reference is made to FIG. 9 , which shows an embodiment of a transmitter 12 in the control device 10 in block diagram format. The position sensor 20 is connected to the microcontroller 22 to report the position of the door 50 , FIG. 1 . The microcontroller 22 may be adapted to monitor the sensor 20 continuously or periodically, for example on the order of seconds or tens of seconds. The microcontroller 22 in the transmitter 12 communicates wirelessly with the receiver 14 via the RF link 24 , which may include a radio transceiver 250 and antenna 252 . A program port 254 may be provided as in the receiver 14 , enabling updates to firmware in the microcontroller 22 . An LED 256 or other indicator may be connected to the microcontroller 22 so that it can provide visual feedback to the user about battery status or other conditions. An audible indicator may be used in addition to or in place of the LED 256 . The microcontroller 22 and other active components in the receiver 14 may be powered by the power source 26 , such as a battery, referenced to a local ground 260 . As with the receiver 14 , the automatic door closer 10 is not limited to the use of a microcontroller 22 and may be adapted to any of a variety of other suitable control systems.
[0044] The control unit 10 may be embodied as an add-on or accessory to an existing garage door opener, or may be built into a garage door opener. The control unit 10 increases security and convenience in operating a door such as an overhead or garage door, automatically closing the door if inadvertently left open or if intentionally and temporarily left open. The control unit 10 is simple to install and to operate, and can help to prevent costly break-ins.
[0045] In conclusion, the present invention provides novel systems, devices, methods and arrangements for automatically closing a powered door. While detailed descriptions of one or more embodiments of the invention have been given above, various alternatives, modifications, and equivalents will be apparent to those skilled in the art without varying from the spirit of the invention. Therefore, the above description should not be taken as limiting the scope of the invention, which is defined by the appended claims. | Control devices that operate automatic door controllers and methods of operating automatic door controllers are disclosed. An embodiment of controller control device that operates with an automatic door closer includes a sensor that is attached to the door, the sensor operable to transmit data indicative of the orientation of the door. The controller also includes a receiver that is operable to receive the data from the sensor; monitor the orientation of the door based on the data received from the sensor; transmit a door closing instruction to the automatic door closer when the door orientation has been open for a first period; and pause the transmitting of door closing information to the automatic door closer for a second period when a pause input is received from a user. | 4 |
BACKGROUND OF THE INVENTION
This invention relates to cleaning material from a suppprt surface, such as an imaging surface of a photocopier. More particularly the invention relates to methods and apparatus in which a cleaning blade engages a surface to be cleaned and the surface is driven past the blade.
To facilitate a clear understanding of the invention it is to be understood that the expressions "upstream" and "downstream" used herein and in the claims have the following meanings. The expression "upstream" refers to that direction from which any point on a movable surface travels. The expression "downstream" refers to that direction towards which any point on a movable surface travels. A cleaning blade may be disposed normally to the surface to be cleaned or it may be tilted in leading or trailing relation to the direction of movement of the surface. Such tilted blades are generally referred to respectively as scraper and wiper blades. These expressions as used herein and in the claims are defined as follows. A "scraper blade" is one which extends towards the surface in the upstream direction and when pressed against the surface exerts a chiselling action on material on the surface. A "wiper blade" is one which extends toward the surface in the downstream direction.
It has been found desirable, for example, in the case of a plastics blade acting on a photosensitive surface to remove residual liquid developer therefrom, in the environment of a xerographic copier, to separate the blade from the surface during shut-down periods, as between copy cycles, to avoid cold flow resulting in deformation of one or both of the blade and the surface. When the blade is removed from the surface, particularly in the case of liquid, material which has piled up against the blade will tend to spread out beyond the blade position when the support from the blade is removed. In an effort to alleviate this problem it is proposed in U.S. Pat. No. 3,940,282 to Hwa, that before each shut-down period, the relative motion between the blade and the surface is reversed prior to removing the blade from the surface. Such reversal of relative motion tends to break up and remove the build-up of material.
SUMMARY OF THE INVENTION
From one aspect, the present invention consists in a method of cleaning a surface by moving the surface in one direction relative to a cleaning blade in engagement therewith with rest periods of no relative motion wherein said blade is moved out of contact with the surface at a first position during a said period of no relative motion and returned thereto at a second position downstream of said first position.
It is to be understood that so long as the blade is returned to the surface at a position downstream of the position at which it is removed, removal may be effected to correspond with cessation of motion of the surface or just before or after. Similarly, return of the blade to engagement with the surface may correspond with restart of the surface or it may occur just before or after restart.
It has also been found that with blade cleaning systems the build-up of the material being removed and also of contaminants, such as dust, will affect its cleaning seal with the surface. In order to reduce this problem it is a preferred feature of this invention to reverse the relative motion of the blade and surface prior to removal of the blade from the surface. This may be achieved by reversing the motion of the surface for cleaning or by moving the blade across the surface in the downstream direction before moving it out of contact with the surface. During this movement the blade may be pressed against the surface so as to flex the cleaning edge thereof out of contact with the surface.
While this invention has broad application to the cleaning of surfaces in general, it is particularly suitable for use in cleaning photosensitive surfaces in electrostatographic reproduction machines and from another aspect the invention consists in an electrostatographic reproduction method comprising forming a latent electrostatic image on a moving support surface, developing the latent image with developer, transferring the developed image on to support material and cleaning the remaining materials from the surface as set out hereinabove.
From a further aspect, the invention consists in apparatus for cleaning a surface including a cleaning blade engageable with said surface, drive means for moving the surface past the cleaning blade with rest periods of no relative motion, and blade translation means for moving the blade out of contact with the surface at a first position during a said period of no relative motion and for returning the blade into engagement with the surface at a second position downstream of said first position.
In a preferred embodiment, a blade translation mechanism is provided by which the blade is moved across the surface before being removed from the surface. Means are provided for moving the blade relative to the surface and the blade is guided during such movement by a cam which is engaged by a follower which is fixed with respect to the blade. The cam is pivotally mounted intermediate its ends, e.g., at the center, and the follower is biased against the cam such that the cam is urged to a first position in which the blade is engaged with the surface when the follower is to one side of the pivot and is urged to a second position in which the blade is disengaged from the surface when the follower is to the other side of the pivot. A solenoid is provided which is operable to override the biasing action of the follower and move the cam from said second to said first position.
In order that the invention, and in particular the operation of the preferred embodiment described in general terms above, may be more readily understood, reference will now be made to the accompanying drawings.
BRIEF DESCRIPTION OF THE DRAWINGS
FIG. 1 is a schematic cross-section illustrating the operation of one embodiment of electrostatographic reproduction machine utilizing the cleaning techniques of this invention;
FIG. 2 is a schematic cross-section illustrating a preferred embodiment of blade translating mechanism for performing the cleaning techniques of the invention showing the blade in its normal cleaning position;
FIG. 3 is a view like that of FIG. 2 showing the blade raised from the surface; and
FIG. 4 is a view like that of FIGS. 2 and 3 showing the blade in its position when returned to the surface.
DETAILED DESCRIPTION
Referring to the drawings, the general operation of an electrostatographic machine as illustrated will first be described with reference to FIG. 1. A moving photoconductive plate, in this instance having an endless surface constituting the periphery of a drum 1, is first uniformly charged at a charging station 2 and the surface then exposed at an exposure station 3 to a light pattern of the image sought to be reproduced thereby to discharge the charge in the area where light strikes the plate surface. The undischarged areas of the surface thus form an electrostatic charge pattern in conformity with the configuration of the original image pattern.
The electrostatic latent image is developed into visible form by the development system 4 by applying liquid developer material to the plate. Subsequent to the development operation the now visible image is transferred from the plate to a sheet of final support material 5, such as paper or the like, thereby to form a permanent print, at a transfer station in accordance with the present invention schematically illustrated at 6. The paper or the like is fed to the transfer station by means (not shown) programmed to deliver the paper in synchronism with the arrival of the developed image.
The development system of the illustrated embodiment employs the techniques described in U.S. Pat. No. 3,084,043 in which the liquid developer is applied to the plate by means of an applicator, in this embodiment in the form of a roll 8 having a peripheral surface comprising lands and valleys such that the liquid developer is contained in the valleys out of contact with the plates, while the surface of the lands are in contact with the plate. In such an arrangement the liquid developer is attracted from the valleys to the electrostatic latent image in image configuration. The illustrated embodiment exemplifies a typical example of such an arrangement in which the applicator is a rigid cylindrical member 8 having on its surface a pattern of grooves and ridges which comprise the lands and valleys respectively, the liquid developer being maintained in the valleys below the surface of the lands.
As a plate surface bearing the electrostatic latent image and the applicator are brought into moving contact, the liquid developer is drawn to the plate surface from the valleys of the applicator roll by the charges which form the electrostatic latent image.
The applicator roll 8 is supplied with liquid developer by a developer supply roll 9 the lower portion of which is disposed in a tray 10 containing liquid developer. The surface of the developer supply roll 9 is arranged in liquid transfer relationship with the peripheral surface of the applicator roll 8 which latter is, in operation, arranged in pressure contact with the surface of the drum 1. Means are provided for driving both of the rolls 8 and 9 in synchronism, or substantially so, with the drum 1. Following transfer, residual developer remaining on the plate surface is removed by a cleaning blade 7 and collected for subsequent disposal. The cleaning blade shown is a scraper blade which is arranged on the downhill or downwardly moving side of the drum 1. The blade may in another arrangement be arranged on the uphill side of the drum as shown for example in FIGS. 2 to 4.
Referring now to FIGS. 2 to 4 there is illustrated a blade translation mechanism in which the blade 7 is supported in a mounting 11 which is freely pivotally supported on a shaft 12 connected between a pair of suspension arms 13 (only one of which is visible). The arms 13 are themselves mounted on a programmer shaft 14 for rotation therewith. The shaft 14 is operated by a cam or other means (not shown) controlled by the machine logic to translate the blade upstream along the drum surface 1 between end positions in timed relation to the operation of the machine. The blade mounting 11 carries a roller follower 15 which is spring loaded (by a tension spring 16 connected to the machine frame 17) against a track member 18 for guiding the blade during movement along the photoreceptor surface. The track 18 is pivoted at its centers on pivot 19 for angular movement between limits defined respectively by the rest position of a solenoid 20 connected to the track, and a stop 21. The solenoid 20 is connected to the track 18 by a lever 22 and when activated urges the track into the position shown in FIG. 2.
The machine logic controls the shaft 14 to operate the blade in the following manner:
(a) At the end of a copy making cycle (following the making of one or a plurality of copies) when the drum is stationary, or as it comes to a rest, to apply a uniform pressure reverse wipe on the photoreceptor for a short distance and then retract the blade to a park position out-of-contact with the photoreceptor;
(b) At the start of a cycle, to return the cleaning blade to the photoreceptor in a position ahead of the parking line before the photoreceptor is moving, or as it begins to move.
The above operation is achieved by the illustrated embodiment in the following way. In the normal cleaning mode as shown in FIG. 2, the drum rotating clockwise, the track 18 is biased to a clockwise position by the follower 15 and the blade is against the photoreceptor 1. (As shown diagrammatically in FIG. 1 the blade is desirably in an interference relationship, e.g., of 2 mm, with the surface 1, the blade being deflected by the surface to a curved configuration as shown in broken lines). As the shaft 14 is rotated at the end of a copying cycle, after the drum 1 has stopped moving, the follower 15 rides along track 18 to cause the blade 7 to wipe in the downstream or reverse direction along the drum surface. This has the desirable effect of releasing developer and contaminants, such as dust, which may have built up underneath the blade and be affecting its cleaning seal with the photoreceptor.
As the follower 15 passes the pivot 19, it causes the track 18 to rotate anti-clockwise retracting the blade from the surface 1 to a park position as shown in FIG. 3. As illustrated, the blade edge may be spaced 2.5 mm from the photoreceptor in its park position. The blade remains in the park position until the machine logic is actuated to start another copy cycle.
Actuation of the machine logic activates the solenoid 20 to rotate track 18 clockwise and bring the blade into engagement with the photoreceptor surface 1 as illustrated in FIG. 4. Simultaneously with the activation of solenoid 20, the drive motor for the drum 1 is activated. It has been found that activation of solenoid 20 will occur more quickly than rotation of the photoreceptor drum 1 due to inertia and compliance in the photoreceptor drive; thus staggered activation of the solenoid and drive motor, with its attendant complications, is not necessary. In one specific embodiment, it has been found that the solenoid will act in 40-50 milliseconds with the photoreceptor beginning to rotate in 400-500 milliseconds. Following application of the blade 7 to the surface 1, the shaft 14 is rotated to return the blade, along the surface, to the normal cleaning position shown in FIG. 2. It will be noted that once the follower has passed the pivot 19, the solenoid may be disengaged since the spring-loaded follower 15 will hold the track in the desired, clockwise, position.
It will be understood that while a specific embodiment has been described, various modifications may be made without departing from the scope of the invention as defined in the appended claims. For example, a variation of the position where the blade 7 leaves the photoreceptor may be obtained by altering the position of pivot 19.
More uniform loading, when considering photoreceptor run-out, may be achieved by spring loading the blade within the cleaning blade assembly.
In FIG. 2 the track 18 has a curved profile which is preferred, but it may have a planar profile as shown in FIGS. 3 and 4. | A method and apparatus for cleaning a surface. The surface is moved in one direction relative to a cleaning blade in engagement therewith. Rest periods are provided of no relative motion wherein the blade is moved out of contact with the surface at a first position during the period of no relative motion. The blade is returned to the surface at a second position downstream of the first position. In accordance with a different embodiment the blade is removed from the surface after the surface has stopped, and is returned to the surface before relative motion commences. | 6 |
BACKGROUND OF THE INVENTION
1. Field of the Invention
This invention relates to welded wire termination and more specifically to a wire termination tab that is integrally formed with a conductive surface, and which is formable into a tubule for receiving a wire for welded termination.
2. Description of the Related Art
In many applications such as satellite solar arrays and printed circuit (PC) boards wires must be terminated to a conductive pad to interconnect circuitry and other electrical systems. Typically, the wire is soldered flat to the conductive pad. However, in high reliability thermally stressful environments solder is not a viable option. Because of the mismatch between the thermal coefficients of expansion (TCE) for the solder, the wire, the conductive pad and its underlying substrate, extended thermal cycling will fatigue the solder and may cause it to crack and eventually fail. A satellite, for example, will thermal cycle between -180° C. and +80° C. for approximately 1600 cycles in a geosynchronous orbit and will thermal cycle between -80° C. and +100° C. for approximately 30,000 cycles in a low earth orbit. Furthermore, direct exposure to an extremely high temperature may liquify the solder causing the joint to fail. The potential for extremely high temperatures exists in military satellites, space probes which utilize solar array aerobraking and some automotive applications. To satisfy the reliability requirements in these types of thermally stressful environments, a non-solder wire termination is required.
The wires, either stranded wire or solid wire, can be terminated to a conductive pad by direct welding. Welding stranded wire to the conductive pad is difficult because the strands separate and may remain loose, thus risking a short circuit. Ensuring each strand is welded is an expensive labor intensive process. Solid wires such as diode or other component leads are difficult to weld because they are typically round and relatively thick, approximately 0.1 cm. Because they are round, the leads present only a small surface contact area with the conductive pad, which weakens the weld joint. Furthermore, the leads cannot be pressed sufficiently to reduce their thickness without sacrificing material integrity. As a result, a high power weld that exerts an extremely high localized pressure, for example 10,000 lbs per square inch (psi), on the underlying substrate is required. The weld may damage the underlying solar panel substrate which is typically formed from a thin brittle material such as graphite or Kevlar®.
A known approach is to crimp a flat lug onto the end of the wire and then weld the flat lug onto the surface of the conductive pad. There are several disadvantages to this process. First, a crimp lug that is strong enough to mechanically hold the wire strands must be relatively thick, e.g. 0.015 to 0.025 cm. The crimp lug is welded to the conductive pad using a pincher weld, in which opposing weld tips are placed on the surface of the lug and underneath the conductive pad, respectively. Because the lug is so thick, a force of approximately 10,000 psi has to be exerted on the weld tips to successfully weld the crimp lug to the conductive pad. Once the conductive pad is mounted onto its substrate, any repairs must be done using a parallel gap weld from the top surface. The extreme force required during welding can damage the thin, brittle graphite or Kevlar® substrates below the conductive pad. Furthermore, crimping the wire strands is an expensive labor intensive process, in which it is difficult to capture every strand. Stray strands can potentially cause a short. Because this approach involves two connections, pad-to-lug and lug-to-wire, the overall reliability of the wire termination is reduced. In addition, the crimped lug increases the series resistance of the connection.
SUMMARY OF THE INVENTION
In view of the above problems, the present invention provides a welded wire termination device and method that reduces the cost and improves the reliability of the welded wire termination in thermally or mechanically stressful environments.
This is accomplished by forming a wire termination tab on a thin conductive pad to define a tubule for receiving a wire, either stranded or solid. The tubule is tweezer welded to form a welded termination joint between the wire and the conductive tab. The tubule easily captures all of the stranded wires and increases the surface area of the weld since it is welded on both sides. A tweezer weld exerts pressure laterally on the tubule, and thus does not exert a force on the underlying substrate that could damage the substrate. This approach creates only a single electro-mechanical connection from the wire to the conductive pad, which is inherently more reliable than multiple connections.
These and other features and advantages of the invention will be apparent to those skilled in the art from the following detailed description of preferred embodiments, taken together with the accompanying drawings, in which:
BRIEF DESCRIPTION OF THE DRAWINGS
FIG. 1 is a plan view of a welded wire termination blank in accordance with the present invention;
FIGS. 2a through 2d illustrate the process of forming the termination blank shown in FIG. 1 to provide a welded termination joint;
FIGS. 3a and 3b are sectional views of an alternate welded termination joint using pincher and parallel gap welding, respectively;
FIGS. 4a and 4b are sectional views of another alternate welded termination joint using pincher and parallel gap welding, respectively;
FIG. 5 is a plan view of an end termination tab for a solar array having integrally formed wire termination tabs;
FIG. 6 is a perspective view of a solar array in which the wires are connected using the welded termination joint of the present invention;
FIG. 7 is a plan view of a PC board having an integrally formed power bus with wire termination tabs;
FIG. 8 is a sectional view of the PC board with the wire termination tabs formed into tubules for receiving a wire; and
FIG. 9 is a perspective view of a pair of welded wire termination pad having tubules for terminating the solid diode leads.
DETAILED DESCRIPTION OF THE INVENTION
The present invention provides a high quality welded wire termination that exhibits a high reliability in a thermally stressful environment and can withstand exposure to extreme temperatures. A wire termination tab is formed on a conductive pad to define a tubule for receiving a wire, either stranded or solid. The tubule is tweezer welded to form a welded termination joint between the wire and the conductive tab. The tweezer weld does not exert a force on the underlying substrate that could damage the substrate. The tubule easily captures all of the stranded wires and increases the surface area of the weld to a solid lead.
FIG. 1 shows a termination blank 10 that includes a conductive pad 12 and a pair of wire termination tabs 14 that are integrally formed with the conductive pad 12 along an interior edge 16 and extend laterally therefrom. The wire termination tabs 14 preferably have opposing sides that extend laterally from the edge 16 and form a pair of rounded corners 15 with the edge, the corners 15 having a radius of curvature that reduces stress on the wire termination tab 14 when the tab is formed into a tubule. As detailed in FIGS. 2a through 2d, the wire termination tabs 14 are formed into tubules above the surface of the conductive pad 12 for receiving and terminating wires to the conductive pad. A layout designer specifies the number, size and position of the tubules on the conductive pad 12 as well as the size and shape of the pad itself. For example, an end termination tab for a solar cell may include three tabs that extend out of the conductive pad for connection underneath the solar cell and include two wire termination tabs for forming tubules to interconnect adjacent end termination tabs. A flat sheet of metal such as silver plated copper, molybdenum, kovar or invar is punched or etched to pattern the termination blank 10 as specified.
To form the tubules and terminate the wires, a die 18 is placed on the surface of the conductive pad 12 adjacent to the interior edge 16 of the wire termination tab 14 as shown in FIG. 2a The die preferably has an oval or circular shape so that the resulting tubule will have smoothed, and thus stronger, shape. The die has a diameter that is slightly larger than the diameter of the wire that will be inserted into the tubule.
As shown in FIG. 2b, the wire termination tab 14 is formed around the die 18 to define a tubule 20 between the wire termination tab 14 and the conductive pad 12. In the preferred embodiment, the exterior edge 22 of the wire termination tab 14 is positioned proximate to the surface of the conductive pad 12, either just touching or slightly spaced apart from its surface.
Once formed, the die 18 is removed and the conductive pad 12 is typically mounted onto a substrate 24 such as a solar panel as shown in FIG. 2c. A wire having strands 28 is inserted into the tubule 20 so that all of the strands 28 are captured by the tubule. Thereafter, the tubule 20 is tweezer welded to form a welded termination joint 30 that electro-mechanically connects the strands 28, and hence the wire, to the conductive pad. A tweezer weld entails placing a pair of electrodes 32 on opposites sides of the tubule 20 and forcing current through them while exerting an approximately lateral inward pressure of 15-20 lbs. The combination of heat and pressure produces the welded termination joint 30.
As shown in FIG. 2d, the pressure of the tweezer weld crushes the tubule inward which flattens the strands 28 and increases the surface area of the welded termination joint 30. To lower its profile, and thus reduce the chance that it could get ripped off of the conductive pad, the crushed tubule 20 is preferably bent down onto the surface of the conductive pad 12. A similar approach can be used for a solid wire.
Because the tweezer weld does not exert a downward force on the conductive pad 12, the underlying substrate 24 is not subjected to a localized force that could damage the substrate. Furthermore, tweezer welding the tubule produces a large and strong welded termination joint 30 that exhibits high reliability under extreme thermal conditions.
FIGS. 3a-3b and 4a-4b depict alternate embodiments of the welded termination joint. In FIGS. 3a and 3b, the wire termination tab 14 is formed so that it defines the tubule 20 and an exterior flange 34 on the surface of the conductive pad 12. The exterior flange 34 is welded to the conductive pad using a pincher weld (FIG. 3a) or a parallel gap weld (FIG. 3b). As long as the conductive pad 12 is not integrally formed with its substrate, the exterior flange 34 can be welded before the conductive pad 12 is attached to its substrate, thus avoiding any damage to the substrate. This approach provides a stronger and more well defined tubule 20 at the cost of an additional weld.
In FIGS. 4a and 4b, the wire termination tab 14 is formed so that it defines the tubule 20 and an interior flange 36 on one side of the tubule adjacent the interior edge 16 and an exterior flange 38 on the other side on the surface of the conductive pad 12. The interior and exterior flanges 36 and 38, respectively, are welded to the conductive pad using a pincher weld (FIG. 4a) or a parallel gap weld (FIG. 4b). A solid wire 39 is inserted into the tubule and tweezer welded. This approach provides an even stronger tubule that is offset from the edge of the conductive pad at the cost of two additional welds.
A particular application for the welded wire termination of the present invention is in interconnection of series connected solar cell strings in a satellite solar array. As shown in FIG. 5, an end termination tab blank 40 is patterned with a conductive pad 42, three solar cell termination tabs 44 that extend laterally from one side of the pad for termination to a solar cell, and three wire termination tabs 46 that extend laterally from the other side of the pad for forming respective tubules to terminate welded wires.
The end termination tab blank 40 is formed into an end termination tab 48 having three tubules 50a, 50b, and 50c and used to clamp the soldered wires in a satellite solar array 52 as shown in FIG. 6. The solar array 52 includes a plurality of solar cells 54 that are connected in series to produce a desired voltage and in parallel to produce a desired current, and mounted on a solar panel substrate 56. The substrate 56 provides a rigid support structure with sufficient axial and bending stiffness for carrying the solar cells through a dynamic launch environment into orbit and positioning them to receive illumination. The substrate 56 is suitably formed by bonding a pair of thin facesheets 60, suitably Kevlar®, graphite or aluminum, onto opposite sides of an aluminum honeycomb core 61. If the material used in the facesheets 60 is conductive, an insulation layer 62 is formed over the top facesheet to electrically isolate the solar cells 54. The combination of the honeycomb core with the stiff facesheets provides a lightweight yet strong substrate 56. The TCEs of graphite and Kevlar® are much lower than the TCEs of the end termination tab and strap. In fact graphite composite structures can have a negative TCE such that it expands when cooled and contracts when heated, which produces stress on the solar array's soldered wires.
The solar cells 54 are connected in series to form strings 63a, 63b, . . . 63n. Each string is terminated with an end termination tab 48 having tubules 50a, 50b, and 50c. The strings are connected in parallel by terminating one end of a wire 64a to via a hole 66 in the substrate to a terminal board (not shown) , typically ground reference potential or the supply voltage. The other end of wire 64a is inserted into the opening defined by the tubule 50a on the end termination tab 48. The ends of wire 64b are inserted into the tubule 50c on the first end termination tab and the tubule 50a on the second end termination tab. The center tubule 50b is unused in this particular application but can be used for redundant wiring or wire rework. The sequence is repeated for each of the n end termination tabs 48 until the last wire is terminated to the reference terminal. The tubules 50a and 50c are tweezer welded to form welded termination joints 68 that connect one end of the strings 63a, 63b, . . . 63n in series/parallel. The other end of the strings 63a, 63b, . . . 63n are similarly terminated to the other reference terminal to complete the series/parallel connection of the solar cells 52.
FIG. 7 is a plan view of a PC board 70 prior to the insertion of a stranded wire. A power bus 72 is integrally formed on the surface of the PC board 70 for distributing electrical signals to the circuitry on the board. A plurality of wire termination tabs 74 are integrally formed with the power bus 72 and extend laterally from the edge of the PC board 70. As shown in FIG. 8, the wire termination tabs 74 are formed on a die to define a tubule 76 over the surface of the power bus 72. i stranded wire 77 is inserted into the tubule 76 and tweezer welded to form a welded termination joint for communicating externals to the circuitry on the PC board 70.
The tubules can be used to rework terminated wires that have to be replaced. For example, if the weld joints between the leads of a diode and respective copper bus pads on a PC board become fatigued or fail, the terminated wires can be reworked by welding a pair of conductive pads formed with a tubule to the respective bus pads, inserting the leads into the tubules, and tweezer welding them to form a reliable weld termination joint. As shown in FIG. 9, a diode 78 is terminated between a pair of bus pads 80 and 82 on a PC circuit board 84 by welding its leads 86 and 88 to tubules 90 and 92, respectively. The tubules are integrally formed on a pair of conductive pads 94, 96, which are parallel gap welded to the bus pads 80 and 82. In an alternate embodiment, the conductive pads could be adhered directly to the PC board using a transfer adhesive.
While several illustrative embodiments of the invention have been shown and described, numerous variations and alternate embodiments will occur to those skilled in the art. For example, instead of patterning the wire termination tab integrally with the end termination tab or PC bus, a discrete wire termination tab could be formed into a yoke shape and either parallel gap or pincher welded to the end termination tab/PC bus to define the tubule. Such variations and alternate embodiments are contemplated, and can be made without departing from the spirit and scope of the invention as defined in the appended claims. | A welded wire termination for use in thermally and mechanically stressful environments is provided by forming a wire termination tab on a conductive pad to define a tubule for receiving a wire, either stranded or solid. The tubule is tweezer welded to form a welded termination joint between the wire and the conductive tab. The tubule easily captures all of the stranded wires and increases the surface area of the weld to a solid lead. A tweezer weld exerts pressure laterally on the tubule, and thus does not exert a force on the underlying substrate that could damage the substrate. This approach creates only a single electro-mechanical connection from the wire to the conductive pad, which is inherently more reliable than multiple connections such as those that are crimped first then welded. | 8 |
BACKGROUND OF THE INVENTION
The present invention relates to a signal generator able to generate at its output a variable output signal, said generator being of the type including at least one transfer device with at least two stages, clocking means to clock an input signal into said transfer device and to step the contents thereof, and an output circuit associated with at least one of said stages and able to collect portions of said input signal therefrom as a function of said variable output signal to be generated and to further process said signal portions.
Such a signal generator is already known from the published French patent application No. 7,520,394 now French Pat. No. 2,315,799. This known signal generator has an output or measuring circuit which includes two differential amplifiers, a sample- and-hold circuit and a switch, one of these differential amplifiers forming an integrator and having two inputs coupled to homologous portions of split electrodes or stages forming part of different cells each including three electrodes. This generator is only able to provide an output signal which varies in a monotonic manner.
SUMMARY OF THE INVENTION
An object of the present invention is to provide a signal generator of the above type but which is of a simpler structure and able to deliver a staircase-shaped variable output signal of any desired form for instance, a waveform with subsequent up and down steps. Such a waveform is particularly useful for converters in which it may be used to arrive at any desired value with a minimum number of steps, i.e. by starting at half the maximum value, by then adding or subtracting one quarter thereof, etc. instead of raise or decrease in a monotonic way.
According to the invention this object is achieved due to the fact that said output circuit includes gating means to selectively collect and gate said signal portions to said output.
By suitably controlling these gating means which can be made very simple, the variable output signal may have any desired staircase shape.
Another characteristic feature of the present signal generator is that prior to said gating means collecting and gating said signal portions from said stages coupled therewith, said clocking means clock said input signal (e.g. Qr/4 in FIG. 8) in all said stages and that said gating means afterwards selectively collect and gate said signal portions (e.g. FIG. 8 right hand table) from said stages to said output according to a predetermined law in order to form thereon successive portions of said variable output signal.
Thus, it is, for instance, possible to generate a staircase-shaped variable output signal having successive different portions or steps corresponding to different fractions of a same signal.
The present signal generator is further characterized in that it includes a second transfer device having an output which is coupled to said output to enable said selectively collected and gated signal portions (e.g. FIG. 8, right hand table) to be combined with, e.g. added to, signals (e.g. Qr/4 in FIG. 8) appearing at said output of said second transfer device and to thus provide a second variable output signal.
Still another characteristic feature of the present signal generator is that prior to said gating means collecting and gating said signal portions from said stages coupled therewith a same second input signal (e.g. Qr/4 in FIG. 8) is clocked in all cells of said second transfer device thus enabling said second input signal to be combined with, e.g. added to, said successive portions of the first variable output signal and thus to provide said second variable output signal.
The present signal generator is further also characterized in that said successive portions of said variable output signal all are fractions of said second input signal (e.g. Qr/4, FIG. 8).
Thus, it is, for instance, possible to add the above mentioned staircase-shaped variable output signal having a plurality of successive different portions or steps corresponding to any of a plurality of fractions of a same signal to the latter signal, i.e. the second reference signal, in order to form a second variable output signal. Such a variable second output signal is useful as a reference signal in converters, more particularly in analog-to-digital converters operating according to a segmented law, e.g. the A-law to determine the digital code of the fraction of the segment of the segmented A-law or / u -law to which an analog input value belongs, the second reference value being a measure of this segment.
The present signal generator is also characterized in that it includes a third transfer device with a set of auxiliary cells and second gating means associated with said auxiliary cells and able to selectively collect and remove portions of signals stored therein according to a second predetermined law and in order that the signal portions remaining in said third transfer device and stepped therein should form successive portions of a third variable output signal.
Thus, it is, for instance, possible to generate a third staircase-shaped output signal having portions or steps corresponding to the segments of the above mentioned segmented law. This variable output signal is again useful as a reference signal in converters, more particularly in analog-to-digital converters to determine the digital code of the segment of the segmented law to which an analog input value belongs.
The present signal generator is also characterized in that said clocking means, said gating means forming part of the first transfer device and said second gating means operate in such a way that said third variable output signal and said second variable output signal successively appear at said output of said second transfer device.
Thus, it is, for instance, possible to successively use the third and second variable output signals as reference signals in analog-to-digital converters to successively determine to which segment and to which fraction of a segment an analog input signal belongs.
The present invention also relates to a signal converter including a comparator for comparing an input signal with a reference signal and for providing an activated output signal when said input signal and said reference signal satisfy a predetermined relationship, said comparator having a first input for applying said input signal, a second input for applying said reference signal and an output at which appears said output signal, said reference signal being provided by a signal generator.
Such a signal converter, i.e. an Analogue-to-Digital converter or the reverse, is also already known from the above mentioned published French patent application No. 752,0394, now French Pat. No. 2,315,799. This known converter includes the above mentioned known signal generator and is, therefore, only able to compare the input signal with the reference output signal raising in a monotonic manner provided by this generator due to which the conversion takes relatively much time.
A further object of the present invention is to provide a signal converter of the above type, but which does not present this drawback.
According to the invention this object is achieved due to the fact that the present converter includes a signal generator according to the invention, as described above.
In accordance with a preferred embodiment the present signal converter includes a comparator the inputs of which are connected with the output of a signal generator and an input voltage. This generator produces successively a first staircase-shaped reference voltage with a monotonically decreasing part the steps of which correspond to the segments of the A- or /u-law and with a second monotonically raising part the end value of which corresponds to the segment to which the input voltage belongs, and an up-and-down going voltage which is superimposed on this end value and the steps of which correspond to the quanta of this segment.
BRIEF DESCRIPTION OF THE DRAWING
The above mentioned and other objects and features of the invention will become more apparent and the invention itself will be best understood by referring to the following description of an embodiment taken in conjunction with the accompanying drawings wherein:
FIGS. 1 and 2 together schematically represent a signal converter and a signal generator according to the invention;
FIGS. 3 to 5 show pulse waveforms generated by pulse generator PG represented in FIG. 2;
FIG. 6 shows the electric charges present in cells c1 to c16 and C1 to C16 of charge transfer devices ctd and CTD represented in FIG. 1 during the time intervals T1 to T37 and T1 to T17, respectively, and represents the electric charges then applied to the comparator COMP of FIG. 1;
FIGS. 7 to 11 represent electric charges present in the cells C1 to C6 of the charge transfer device CTD of FIG. 1 during time intervals T18 to T37 and for various cases and represent the electric charges then applied to the comparator COMP of FIG. 1;
FIG. 12 represents another embodiment of a signal converter according to the invention.
DESCRIPTION OF THE PREFERRED EMBODIMENTS
The signal converter shown in FIGS. 1 and 2 is an analog-to-digital converter able to convert a positive analogue value into a digital value according to the well known segmented A-law. This digital value has the form a2a1a0b3b2b1b0 wherein: a2, a1, a0 are the segment bits defining the 8 segments S1 to S8 of this A-law; b3, b2, b1, b0 are the mantissa bits defining the 16 quantums q1 to q16 in each of these segments.
This analog-to-digital converter includes two charge transfer devices ctd and CTD shown in FIG. 1 and a control device associated therewith and mainly represented in FIG. 2.
This control device (FIG. 2) includes a pulse generator PG, a code translation circuit CTT, bistable devices BS1 to BS9, D-flipflops DFF1 to DFF4, AND-gates G1 to G21, OR-gates or mixers M1 to M12 and inverter IV1. The means to reset PG, CTT, BS1-BS9 and DFF1-DFF4 to their rest condition are not shown.
The pulse generator PG generates at its outputs F1 to F3 three correspondingly-named control pulse waveforms F1 to F3 (FIGS. 3 to 5) which are time-shifted by one third T/3 of a period or time interval T and which are used for controlling the direct charge transfer in the charge transfer devices ctd and CTD (FIG. 1), as will be explained later. At its outputs f1 to f3 the pulse generator PG further generates three correspondingly-named control pulse waveforms f1 to f3 which are time-coincident with F1 to F3, respectively, but which have a higher amplitude, although this does not appear from FIGS. 3 to 5. The control pulse waveforms f1 to f3 are used for controlling the lateral charge transfer in the lateral charge transfer devices LCTD73 to LCTD103 forming part of the charge transfer device CTD, as will also be explained later. Finally, the pulse generator PG generates at its outputs P1 to P38 correspondingly-named sampling pulses P1 to P38 which appear at the output of the mixer M12 as a series P of 38 sampling pulses. These sampling pulses are synchronized with the pulses of the control pulse waveforms F1 to F3 and f1 to f3. Indeed, the rear edges of the pulses P1 to P38 occur in the center of the pulses of the control pulse waveforms F3 and f3 (FIGS. 3,4). The code translation circuit CTT is able to translate an input code applied to its inputs by the gates G7 to G14 into the segment codes 111; 110; 101; 100; 011; 010; 001; 000 associated to the segments S8 to S1 of the A-law respectively. This happens according to the following table:
______________________________________input code segment codesG7 G8 G9 G10 G11 G12 G13 G14 a2 a1 a0______________________________________1 0 0 0 0 0 0 0 1 1 10 1 0 0 0 0 0 0 1 1 00 0 1 0 0 0 0 0 1 0 10 0 0 1 0 0 0 0 1 0 00 0 0 0 1 0 0 0 0 1 10 0 0 0 0 1 0 0 0 1 00 0 0 0 0 0 1 0 0 0 10 0 0 0 0 0 0 1 0 0 0______________________________________
The bits b3, b2, b1 and b0 of the mantissa or quantum b3b2b1b0 of each of these segments are provided by the Q-outputs of the D-flipflops DFF1 to DFF4, respectively.
The charge transfer device ctd (FIG. 1) comprises:
an input diode electrode id having an input terminal i used for applying an input signal Vin thereto;
an input gate electrode ig having a control terminal P connected to the like-named output P of the mixer M12 associated with the pulse generator PG;
cells c1 to c16 each controlled by the charge transfer control waveforms F1 to F3. Cell c1 comprises four transfer electrodes or stages ate 13, tell, te12, te13, ate13 being an auxiliary transfer electrode, and each of the cells c2 to c16 comprises three transfer electrodes or stages. For instance, the cells c6, c7, c10 and c16 comprise the transfer electrodes te61, te62, te63; te71, te72, te73; te101, te102, te103; and te161, te162, te163, respectively. The electrodes te11, . . . , te61, . . . , te101, . . . , te161; te12, . . . , te62, . . . , te102, . . . , te162; and ate 13, . . . , te63, . . . , te103, . . . , te163 have control terminals connected to the outputs F1, F2 and F3 of the pulse generator PG, respectively;
an output gate electrode og with a control terminal og connected to the like-named 1-output og of the bistable device BS1 (FIG. 2); and finally
an output diode electrode od with an output terminal connected to an input I1 of a comparator COMP having an output terminal comp which is connected to the control device of FIG. 2.
The charge transfer device CTD comprises:
an input diode electrode ID with an input terminal I;
an input gate electrode IG with a control terminal P connected to the like-named output P of the mixer M12 associated with the pulse generator PG;
cells C1 to C16 each controlled by the charge transfer control waveforms F1 to F3. These cells are similar to the cells c1 to c16 of the ctd and are controlled in a like manner, except for the fact that the elements below the third transfer electrodes of the cells C1 to C10 are divided in two like halves by a small diffusion;
output gate electrode OG with control terminal OG connected to the like-named 1-output OG of the bistable device BS8 (FIG. 2);
a drain gate electrode DG with a control terminal DG connected to the like-named 0-output DG of the bistable device BS8;
an output diode electrode OD with an output terminal connected to an input 12 of the comparator COMP;
a lateral drain diffusion LDD with a control terminal connected to a DC-voltage DC;
lateral drain gates LDG13 to LDG63 associated with the third transfer electrodes TE13 to TE63 of the cells C1 to C6 and controlled by the like-named outputs LDG13 to LDG63 of the AND-gates G1 to G6 (FIG. 2), respectively;
a lateral drain diffusion LDD1 with a control terminal connected to the DC voltage DC;
lateral charge transfer devices LCTD73 to LCTD103 which are associated with the third transfer electrodes TE73 to TE103 of the cells C7 to C10, respectively, and which each comprise: a lateral input gate electrode LIG73 to LIG103, four transfer electrodes ALTE73, LTE71, LTE72, LTE73 to ALTE103, LTE101, LTE102, LTE103; a lateral output gate electrode LOG73 to LOG103, a lateral drain gain electrode LDG73 to LDG103; a lateral output diode LOD73 to LOD103; and a lateral drain diffusion LDD73 to LDD103. The LIG73 to LIG103 are controlled by the output LIG73-LIG103 of the AND-gate G15. The electrodes LTE71 to LTE101, LTE72 to LTE102; and ALTE73, LTE73 to ALTE103, LTE103 of the lateral cells LC7 to LC10 are controlled by the charge transfer control waveforms f1 to f3, respectively. The LOG73 to LOG103 have control terminals connected to the like-named outputs LOG73 to LOG103 of the mixers M6, M8, M10, M11 (FIG. 2), respectively, while the LDG73 to LDG93 are controlled by the like-named outputs of the AND-gates G17, G19, G21. The LDG103 is not used. The lateral output diode electrodes LOD73 to LOD103 have output terminals connected to the input I2 of the comparator COMP, while the lateral drain diffusions LDD73 to LDD103 are connected to the DC voltage DC.
The comparator COMP provides a 1-output when the difference of the signals applied to its inputs I1 and I2 are positive or zero, and a O-output when this difference is negative.
It should be noted that the shaded paths on the drawing represent stop diffusion layers.
The operation of the above described analog-to-digital converter is described hereinafter.
A positive analog input voltage Vin to be converted to a digital value according to the above mentioned segmented A-law is applied to the input terminal i of the charge transfer device ctd, while a reference voltage Vr/2 is applied to the input terminal I of the charge transfer device CTD to be compared with the input voltage Vin. The various charge transfer control waveforms F1 to F3 and f1 to f3, the sampling pulses P and the DC voltage DC are applied to the corresponding control terminals of the converter. It should be noted that the input voltage Vin, for instance, is already a sample, e.g. taken every 125 microseconds, of another input voltage which is sampled at a frequency of 8 kHz by a sample-and-hold device (not shown) and stored in the capacitor included therein. For this reason, during the operation to be described, Vin may be considered as a constant.
The converter is able:
with the help of the charge transfer device ctd and the control means associated therewith to continuously apply an electric charge Qin corresponding to Vin to the comparator input I1, from the time interval T17 on;
with the help of the charge transfer device CTD and the control means associated therewith:
to determine, during the time intervals T18 to T24, the segment to which the Vin belongs. Use is hereby made of the lateral drain gates LDG13 to LDG63 and the lateral drain diffusion LDD1 and by successively applying electric charges corresponding to the segments S8 to S1 to the comparator input I2;
to determine during the time intervals T24 to T37 the quantum to which the Vin belongs. Use is hereby made of the lateral charge transfer devices LCTD73 to LCTD103 and by applying electric charges corresponding to 8, 4, 2 and 1 segment quantums to the comparator input I2.
First the operation of the charge transfer device ctd is considered, reference being particularly made to FIGS. 1 to 3 and 6.
At the moment the input gate ig is activated by the sampling pulse P1 shortly after the start of the time interval T1 (FIG. 3) an electric charge Qin which is a measure of the input voltage Vin is formed under the auxiliary transfer electrode ate13 of the charge transfer device ctd because the latter electrode ate13 is at that moment activated by pulse 0 of the control pulse waveform f3 (FIG. 3). When this sampling pulse P1 ends, this electric charge Qin is isolated from under the input gate electrode ig. This means that the constant input voltage Vin has been sampled by the sampling pulse P1. When afterwards during the same time interval T1 the transfer electrode tell of the ctd is activated by pulse 1 of the transfer control pulse waveform F1 (FIG. 3) this electric charge Qin is spread-out under both the transfer electrodes ate13 and te11. Subsequently, at the moment the pulse 0 of the transfer control waveform F3 ends the electric charge Qin under the transfer electrode te11 is isolated. Thus, the electric charge Qin has been transferred from under the transfer electrode ate13 to under the transfer electrode te11. In an analogous way, the electric charge Qin is transferred from under the transfer electrode te11 to under the transfer electrode te12 and then from under the latter transfer electrode te12 to under the transfer electrode te13. This electric charge is situated solely under the latter electrode at the end of pulse 1 of the transfer control waveform F2, i.e. before the start of the time interval T2.
From the above it follows, as is represented on FIG. 6, that during the time interval T1 an electric charge Qin is entered in the cell c1 of the charge coupled device ctd. During the following time interval T2 a same electric charge Qin is entered in the cell C1, while that stored in the cell c1 is transferred to the cell c2 of the ctd, etc. Finally, during the time interval T16 a same electric charge Qin is entered in the cell c1 and the electric charges Qin stored in the cells c1 to c15 are shifted into the cells c2 to c16, respectively.
Shortly after the start of the time interval T17 and by the sampling pulse P17 (FIG. 3) the bistable device BS1 (FIG. 2) is triggered to its 1-condition wherein it activates output gate og. Because at that moment an electric charge Qin is stored under the transfer electrode te163 of cell c16 this electric charge Qin then appears on the output diode od from which it is supplied to the input I1 of the comparator COMP. The sampling pulse P17 and obviously also the following sampling pulses P18 to P38 applied to the input gate ig shift contents of the charge transfer device ctd so that also during the time intervals T18 to T37 an electric charge Qin is stored on the output diode od and supplied to the input I1 of the comarator COMP (FIG. 6).
The operation of the charge transfer device CTD is now considered in detail, reference being particularly made to FIGS. 1, 2, 4 and 6.
In an analogous way as described above for the charge transfer device ctd, and at the moment the input gate IG of the CTD is activated by the sampling pulse P1, shortly after the start of the time interval T1, an electric charge QR/2 which is a measure of the reference voltage Vr/2 is formed under the auxiliary transfer electrode ATE13 of the CTD because at that moment the latter electrode ATE13 is activated by pulse 0 of the waveform F3 (FIG. 4). When this sampling pulse P1 ends, this electric charge Qr/2 is isolated from under the input gate electrode IG, and when afterwards and during the same time interval T1 the transfer electrode TE11 of the CTD is activated by pulse 1 of the waveform F1 (FIG. 4) this electric charge Qr/2 is spread-out under both the transfer electrodes ATE13 and TE13. Subsequently, at the moment the pulse 0 of the waveform F3 ends the electric charge Qr/2 under the transfer electrode TE11 is isolated. In an analogous way this electric charge Qr/2 is transferred first from under the transfer electrode TE11 to under the transfer electrode TE12 (at the end of pulse 1 of waveform F1 the charge is situated solely under this electrode) and then from under the latter transfer electrode TE12 to under the transfer electrode TE13. This happens at the start of pulse 1 of the waveform F3. Because the element under the transfer electrode is split in two like portions, an electric charge equal to Qr/4 is then present under TE13.
From the above, as represented on FIG. 6, it follows that during the time interval T1 an electric charge Qr/2 is entered in the cell C1 of the charge transfer device CTD. During the following time interval T2 an electric charge Qr/2 is entered in the cell C1 and split in two equal portions equal to Qr/2 under the transfer electrode TE13, while the electric charge Qr/2 stored in the cell C1 is transferred to the cell C2 of the CTD. Because also under the third transfer electrode of this cell C2 the electric charge is split in two equal portions, two electric charges equal to Qr/4 are present under this transfer electrode near the end of this time interval T2, the total electric charge being however equal to Qr/2 (FIG. 6).
Shortly after the start of the time interval T3 (FIG. 4) the sampling pulse P3 triggers the bistable device BS2 (FIG. 2) to its 1-condition wherein the AND-gate G1 controlling the lateral drain gate LDG13 is activated. As a consequence, sampling pulses P3 to P38 may be supplied to this lateral drain gate LDG13. Because the lateral drain diffusion LDD1 is continuously activated by the DC voltage applied thereto the sampling pulse P3 has the effect that:
the electric charge Qr/4 stored in the lower half of the element situated under the transfer electrode TE13 is drained away, so that a total electric charge equal to Qr/4 remains under this electrode;
a new electric charge Qr/2 is entered in the cell C1 and stored under the auxiliary transfer electrode ATE13, which is still activated by the pulse 2 of the waveform F3. All this happens before the pulses 3 of the waveform F1, F2 and F3 are applied to the CTD. By these pulses the electric charges in the CTD are shifted so that at the end of the time interval T3 electric charges Qr/2, Qr/4 and Qr/2 are stored in the cells C1, C2 and C3, respectively, as represented on FIG. 6.
In an analogous way, during the time interval T4 a new electric charge Qr/2 is stored in cell C1, an electric charge Qr/4 is stored in cell C2, an electric charge Qr/4 is stored in cell C3, and an electric charge Qr/2 is stored in cell C4. It should be noted that the electric charge Qr/4 in cell C2 is split in two like portions equal to Qr/8.
Shortly after the start of the time interval T5 the sampling pulse P5 triggers the bistable device BS3 to its 1-condition wherein it enables AND-gate G2 which controls the lateral drain gate LDG23 (not shown) associated with the third electrode of cell C2. As a consequence, the samplling pulses P5 to P38 may be supplied to this lateral drain gate LDG23. Because the lateral drain diffusion LDD1 is continuously activated the sampling pulse P5 has the effect that:
the electric charge Qr/4 stored in the lower half of the element situation under the transfer electrode TE13 of cell C1 is drained away via LDG13 so that a total electric charge equal to Qr/4 remains under this electrode;
the electric charge Qr/8 stored in the lower half of the element situated under the transfer electrode TE23 (not shown) of cell C2 is drained away via LDG23 so that a total electric charge equal to Qr/8 remains under this electrode;
a new electric charge Qr/2 is entered in the cell C1 and stored under the auxiliary transfer electrode ATE13 which is still activated by the pulse 4 of the waveform F3. All this happens before the pulses 5 of the waveforms F1, F2 and F3 are applied to the CTD. By these pulses the electric charges in the CTD are shifted, so that at the end of the time interval T5 electric charges Qr/2 Qr/4 Qr/8 Qr/4 and Qr/2 are stored in the cells C1 to C5, respectively, as shown on FIG. 6.
In a similar way, as described above, the following happens
during time interval T6 electric charges are drained via the lateral drain gates LDG13 and LDG23 (not shown);
during time interval T7 the bistable device BS4 is triggered to its 1-condition wherein it activates AND-gate G3 controlling the lateral drain gate LDG33 (not shown) associated with the third transfer electrode TE33 (not shown) of cell C3. As a consequence, half of the electric charge under this electrode is drained away. The same happens with the electric charges in the cells C1 and C2; etc.
during time interval T13 the bistable device BS7 is triggered to its 1-condition wherein it activates AND-gate G6 controlling the lateral drain gate LDG63 associated with the third transfer electrode TE63 of cell C6. As a consequence, half of the electric charge under this electrode is drained away and the same is true for the electric charges in the cells C1 to C5. Hence, from the time interval T13 on the electric charges Qr/2 entered in the CTD are successively divided by two in all the cells C1 to C6, as shown in FIG. 6.
At the end of the time interval T16 an electric charge Qr/2 is stored under the third electrode TE163 of the cell C16 from the start of the pulse 16 of the waveform F3 on. Shortly after the start of the time interval T17 and by the sampling pulse P17 (not shown) the bistable device BS8 is triggered to its 1-condition whereby the output gate OG is enabled and the drain gate DG is inhibited. Because an electric charge Qr/2 is then stored under the transfer electrode TE163 of cell C16 this electric charge Qr/2 then appears on the output diode OD from which it is supplied to the input I2 of the comparator COMP.
From the above it follows that during time interval T17 electric charges Qin and Qr/2 are formed on the output diodes od and OD and supplied to the input terminals I1 and I2 of the comparator COMP. Although the electric charges Qin and Qr/2 are applied to separate inputs of this comparator, in the FIGS. 6 to 11 the charge applied to the comparator is represented by Qin-Qr/2 for simplicity reasons. This is always done in what follows.
Various cases are now considered, reference being particularly made to FIGS. 1, 2, 5 and 7 to 11.
When the input voltage Vin is equal to or larger than half the reference voltage, i.e. Vr/2, and therefore belongs to segment 8 of the A-law curve, the output comp of the comparator COMP is activated (1) so that the bistable device BS2 is then reset to its O-condition by the sampling pulse P18 because this pulse then activates the output of AND-gate G7. As a consequence, the AND-gate G1 is disabled and the output LDG13 thereof is de-activated so that electric charges can no longer be drained away via the lateral drain gate LDG13 and the LDD1. Also due to the output of AND-gate G7 being activated the outputs of the mixers M1 to M5 are successively activated, as a consequence of which the bistable devices BS3 to BS7 are reset to their O-condition so that electric charges also can no longer be drained away via the lateral drain gates LDG23 to LDG63 and the LDD1. Hence, during the successive time intervals T18 to T33 electric charges equal to Qr/2 are successively applied to the CTD and are no longer divided by 2 in the cells C1 to C6, so that the contents thereof vary as indicated on FIG. 7. Hereby the condition of the output comp of the comparator COMP obviously does not change. At the end of the time interval T33 the electric charges stored in the cells C1 to C16 all are equal to Qr/2, i.e. to a value corresponding to the beginning of segment 8, while the electric charges applied to the comparator inputs are equal to Qin and Qr/2, respectively.
It should be noted that as soon as the output of the gate G7 is activated, the code translation circuit CTT provides an output a2a1a0=111 indicating that the input voltage Vin belongs to segment S8 having code a2a1a0=111.
When, on the contrary, the input voltage Vin is smaller than half the reference voltage Vr/2 and, therefore, belongs to one of the segments S1 to S7, the output comp of the comparator COMP remains de-activated (O), so that the following sampling pulse P18 has no influence on the condition of the bistable device BS2 nor of the other bistable devices BS3 to BS6. Consequently, during the time interval T18 the contents of the CTD vary as indicated on FIG. 8 and during this time interval an electric charge equal to Qr/4 is supplied to the input I2 of the comparator COMP. An electric charge equal to Qin is simultaneously supplied to the input I1 thereof.
When the input voltage Vin is equal to or larger than Vr/4 and, therefore, belongs to segment S7 the output of the comparator COMP is activated (1) so that the bistable device BS3 is then reset to its O-condition by the sampling pulse P19 which then activates the output of AND-gate G8. As a consequence, the AND-gate G2 is inhibited and the output LDG23 thereof is de-activated so that electric charges can no longer be drained away via the lateral drain gate LDG23 and the LDD1. Also, due to the output of AND-gate G8 being activated, the outputs of the mixers M1 to M5 are successively activated, as a consequence of which the bistable devices BS4 to BS7 are reset to their O-condition so that electric charges can also no longer be drained away via the lateral drain gates LDG33 to LDG63 and the LDD1. Hence, during the successive time intervals T19 to T33 electric charges equal to Qr/2 are successively entered into the CTD and are only divided by 2 in cell C1 so that the contents of the CTD vary as indicated on FIG. 8. Hereby the condition of the output comp of the comparator COMP obviously does not change. At the end of the time interval T33 the electric charges stored in the cells C2 to C16 all are equal to Qr/4, i.e. to a value corresponding to the beginning of segment 7, while the electric charge supplied to the inputs of the comparator COMP are equal to Qin and Qr/4, respectively. It should be noted that as soon as the gate G8 is activated the code translation circuit CTT provides the output 110 indicating that the input voltage Vin belongs to segment S7 having code a2a1a0≡110.
When, on the contrary, the input voltage Vin is smaller than Vr/4 and, therefore, belongs to one of the segments S1 to S6, the output comp of the comparator COMP remains deactivated (0), so that the following sampling pulse P19 has no influence on the condition of the bistable device BS3 nor of the bistable devices BS4 to BS7. Consequently, during the time interval T19 the contents of the CTD vary as indicated on FIG. 9, and during this time interval an electric charge equal to Qr/8 is supplied to the input I2 of the comparator COMP. An electric charge equal to Qin is applied to the input I1 thereof.
In a similar way, as described above the following happens:
when Vin-Vr/8≧0 thus indicating that Vin belongs to segment S6, the output comp of the comparator COMP is activated (1) so that the bistable devices BS4 to BS7 are reset to their O-condition by the sampling pulse P20, the AND-gate G9 being activated. As a consequence, electric charges can no longer be drained away via the lateral drain gates LDG33 to LDG63. Therefore, during the successive time interval T20 to T33 electric charges equal to Qr/2 are entered into the CTD and are only divided by 2 in the cells C1 and C2 so that the contents of the CTD vary as indicated on FIG. 9. Hereby the condition of the output comp of the comparator COMP obviously does not change. At the end of the time interval T33 the electric charges stored in the cells C3 to C16 all are equal to Qr/8, i.e. to the value corresponding to the beginning of segment S6, while the electric charges supplied to the inputs of the comparator COMP are equal to Qin and Qr/8, respectively. It should be noted that as soon as the gate G9 is activated the CTT provides the output 101 indicating that Vin belongs to the segment S6 with code a2a1a0≡101;
when Vin-Vr/8<0, thus indicating that Vin belongs to one of the segments S1 to S5, during the time interval T20 an electric charge euqal to Qr/16 is applied to the input I2 of the comparator COMP, the condition of the bistable devices BS2 to BS8 remaining unchanged;
when Vin-Vr/16≧0 thus indicating that Vin belongs to the segment S5 the lateral drain gates LDG43 to LDG63 are inhibited, but the LDG13 to LDG33 remain activated. This happens during time interval T21. Hence, at the end of time interval T33 the electric charges stored in the cells C4 to C16 all are equal to Qr/16, i.e. the value corresponding to the beginning of segment 5, while the electric charges supplied to the inputs of the comparator COMP are equal to Qin and Qr/16 respectively. It should be noted that the segment code is a2a1aO≡100;
when Vin -Vr/16<0, thus indicating that Vin belongs to one of the segments S1 to S4, during time interval T21 an electric charge equal to Qr/32 is applied to the input I2 of the comparator COMP;
when Vin -Vr/32>0, thus indicating that Vin belongs to the segment S4, during time interval T22 the lateral drain gates LDG53 and LDG63 are inhibited, but the LDG13 to LDG43 remain activated. Consequently, at the end of time interval T33 the electric charges stored in the cells C5 to C16 all are equal to Qr/32, i.e. to the value corresponding to the beginning of segment S4, while the electric charges applied to the inputs of the comparator COMP are equal to Qin and Qr/32, respectively. The segmment code is a2a1a0≡011;
when Vin-Vr/32<0, thus indicating that Vin belongs to one of the segments S1 to S3, during time interval T21 an electric charge equal to Qr/64 is applied to the input I2 of the comparator COMP;
when Vin-Vr/64≧0, thus indicating that Vin belongs to the segment S3, during time interval T23 the lateral transfer gate LDG63 is inhibited, following the occurrence of the sampling pulse P23, but the LDG13 to LDG53 remain enabled. Consequently, at the end of time interval T33 the electric charges stored in the cells C6 to C16 all are equal to Qr/64, i.e. to the value corresponding to the beginning of the segment S3, while the electric charges applied to the inputs of the comparator COMP are equal to Qin and Qr/64, respectively. The segment code provided at the output of the CTT is equal to a2a1a0≡010;
when Vin-Vr/64<0, thus indicating that Vin belongs to one of the segments S1 and S2, during time interval T23 an electric charge equal to Qr/128 is applied to the input I2 of the comparator COMP;
when Vin-Vr/128≧0, thus indicating that Vin belongs to the segment S2, all the LDG13 to LDG63 remain activated. The gate G13 is activated by the sampling pulse P24 so that the CTT provides the output a2a1a0≡001. Consequently, at the end of the time interval T33 the electric charges stored in the cells C7 to C16 all are equal to Qr/128, i.e. to the value corresponding to the beginning of the segment S2, while the electric charges supplied to the inputs of the comparator COMP are equal to Qin and Qr/128, respectively (FIG. 10).
when Vin-Vr/128<0 (FIG. 11), thus indicating that Vin belongs to the segment S1, all the LDG13 to LDG63 remain activated. During time interval T24 and more particularly by the sampling pulse P24 activating the output of gate G14 because the comparator output is on O, the bistable device BS8 is reset to its O-condition whereby the output gate OG is inhibited and the drain gate DG is enabled. Electric charges can thus be drained away via the gate. Consequently, during the time intervals T24 to T33 the electric charges which all are equal to Qr/128 are prevented from being transferred on the output diode OD so that only the electric charge Qin is supplied to the comparator COMP. The CTT provides the output a2a1a0≡000.
From the above it follows that for each of the cases just considered, at the end of time interval T33 the electric charges stored in the cells C7 to C16 all have a value equal to Qr/2, Qr/4, . . . , Qr/128 corresponding to the beginning of the segments S8 to S2 to which the input voltage Vin belongs, while the electric charge applied to the input I2 of the comparator COMP also has this value. The code a2a1a0 of this segment is provided by the CTT.
However, for the segment S1 the electric charges stored in the cells C7 to C16 are the same as for segment S2, but the electric charge applied to the input I2 of the comparator COMP is O.
It will now be described how for the Vin and during the time intervals T34 to T37 the mantissa or quantum code b3b2b1b0 is obtained for each of the above considered segments S1 to S8. These quantums are indicated by q1 to q16 having, respectively, the codes b3b2b1b0≡1111 to b3b2b1b0≡0000.
By the sampling pulse P34 (FIG. 5) the bistable device BS9 is triggered to its 1-condition wherein the AND-gate G15 is activated. This gate allows the pulses P34 to P38 to be supplied to the lateral input gate electrodes LIG731 to LIG1031 associated with the lower halves of the elements situated below the third transfer electrodes TE73 to TE103 of the CTD and belonging to the lateral charge transfer devices LCTD73 to LCTD103. Because these transfer electrodes TE73 to TE103, activated by the pulse 33 of the control pulse waveform F3, are then at a lower voltage than the lateral transfer electrodes ALTE73 to ALTE103 which are activated by the pulse 33 of the control pulse waveform f3, the electric charges located under the lower halves of the elements situated under the transfer electrodes TE73 to TE103 are spread-out under the lateral input gates LIG73 to LIG103 and the lateral transfer electrodes ALTE73 to ALTE103 of the LCTD73 to LCTD103, respectively. At the end of the sampling pulse P34 these electric charges are completely located under the latter electrodes, these electric charges have the same value equal to a corresponding one of the values Qr/4, Qr/8, . . . , Qr/256, Qr/256 depending on the segment S8, S7, . . . , S2, S1 to which Vin belongs, because the total electric charge under the whole transfer electrodes TE73 to TE103 are all the same and have a value equal to a corresponding one of the values OR/2, Or/4, . . . , Qr/128, Qr/128.
The electric charge deviated into the cells LC7 to LC10 of the LCTD73 to LCTD103 are shown in FIGS. 7 to 11. It is clear that at the end of pulse P34 also the electric charges located under the third electrodes TE73 to TE103 of the CTD all are the same and have a value equal to a corresponding one of the values Qr/4, . . . , Qr/256, Qr/256.
By the pulses 34 of the control pulse waveforms f1 to f3 controlling the lateral transfer electrodes of the LCTD73 to LCTD103 these electric charges Qr/4, . . . , Qr/256 are transferred to these lateral charge transfer devices. Likewise, by the pulses 34 of the control pulse waveforms F1 to F3 controlling the transfer electrodes of the charge transfer device CTD the electric charges contained therein are shifted by one step so that the electric charges at the end of time interval T34 have values as indicated on the FIGS. 7 to 11.
Therefrom it follows that the electric charge applied to the comparator COMP at the end of the time interval T34 is the same as at the end of the time interval T33 so that the comparator output comp remains on 1.
For instance, when Vin was found to belong to the segment S8 (FIG. 7), at the end of the time interval T34 the contents of the cells C7 to C10 are Qr/2, Qr/4, Qr/4, Qr/4 respectively, while those of the cells LC7 to LC10 are Qr/4, Qr/4, Qr/4, Qr/4, respectively. Electric charges equal to Qin and Qr/2 are applied to the inputs of the comparator COMP respectively.
By the sampling pulse P35 (FIG. 5) generated shortly after the start of the time interval T35:
electric charges equal to half the total electric charge stored in the cells C7 to C10 of the CTD are laterally deviated therefrom and stored under the electrodes ALTE73 to ALTE103 of the cells LC7 to LC10 of the LCTD73 to the LCTD 103, respectively, in a similar way as described above for the sampling pulse P34. These electric charges are shown on FIGS. 7 to 11 (time interval T35);
the lateral output gate LOG73 forming part of the LCTD73 is enabled for the duration of the pulse P35 via the OR-gate M6 so that the electric charge, present under the third transfer electrode LTD73 of the LCTD73 since the end of time interval T34, i.e. Qr/4, . . . , Qr/256, is transferred under the lateral output diode LOD73. From the later diode it is applied to the input I2 of the comparator COMP so that the electric charges present at this input I2 shortly after the start of the time interval T35 is equal to Qr/2+Qr/4, . . . , Q/128+Q/256, Qr/256 when the Vin belongs to segment S8, . . . , S1, respectively. As a consequence, the condition of the output comp of this comparator COMP becomes 0 or remains on 1 depending on the Vin belonging to the 8 upper (q9-q16) or 8 lower (q1-q8) quantums of the corresponding segment. In the former case, the electric charge Qr/4, . . . , Qr/256 should be continued to be applied via the lateral output diode LOD73 to the comparator COMP during the remaining time intervals T36-T37, whereas it should be removed in case the comparator output comp becomes 0. For this reason, the condition of this output comp is registered in the D-flipflop DFF1 by the rear edge of the sampling pulse P35:
in case the comparator output comp remains on 1 (quantums q9-q16) this flipflop DFF1 is triggered to its 1-condition whereby the AND-gate G16 is activated so that the sampling pulses P36 to p38 appearing at the output of OR-gate M7 during the time intervals T36 to T38 will be supplied to the LOG73 via this gate and the OR-gate M6 and that the above electric charges Qr/4, . . . , Qr/256 will then be applied to the comparator;
when the comparator output comp becomes 0 (quantums q1-q8) the D-flipflop DFF1 remains in its 0-condition so that the LOG73 is inhibited and the AND-gate G17 is enabled. Consequently, the sampling pulses P36 to P38 generated during the T36 to T38 will thus be supplied to the lateral drain gate LDG73 via this gate G17 so that the above electric charges Qr/4, . . . , Qr/256 will then not be applied to the comparator.
It is clear from the above that the Q-output b3 of the D-flipflop DFF1 produces the bit b3 of the quantum code b3b2b1b0.
By the pulses 35 (FIG. 5) of the control pulse waveforms F1 to F3 and f1 to f3 the electric charges are then shifted in the CTD and in the LCTD73 to the LCTD103 so that at the end of the time interval T35 the contents of these charge transfer devices are as shown on FIGS. 7 to 11.
For instance, when earlier Vin was found to belong to one of the upper quantums q9-q16 of the segment S8, at the end of the time interval T35 the electric charges stored in the cells C7 to C10 are Qr/2, Qr/4, Qr/8, Qr/8, respectively, those stored under the third electrodes LTE73 to LTE103 of the cells LC7 to LC10 are Qr/4, Qr/8, Qr/8, Qr/8, respectively, and the electric charge applied to the inputs of the comparator COMP are equal to Qin and Qr/2+Qr/4, respectively (FIG. 7). For the other FIGS. 8 to 11 it is also supposed that the Vin belongs to one of the quantums q9 to q16.
By the sampling pulse P36 (FIG. 5) generated shortly after the start of the time interval T36:
electric charges equal to half the electric charges stored in the cells C7 to C10 of the CTD at the end of the time interval T35 are laterally deviated therefrom and stored under the electrodes ALTE73 to ALTE103 of the cells LC7 to LC10 of the LCTD73 to the LCTD103, respectively, in a similar way as described above for the sampling pulse P34. These electric charges are shown on FIGS. 7 to 11 (time interval T36):
when the comparator output comp was previously found to be on 1 (quantums q9-q16) the LOG73 is activated via the OR-gate M7, the AND-gate G16 and the OR-gate M6 for the duration of the pulse P36, whereas when this output was previously found to be on O (quantums q1-q8) the LDG73 is activated for the duration of this pulse P36. Consequently, the electric charge (Qr/4, . . . , Qr/256) present under the electrode LTE73 since the end of the time interval T35 either is continued to be applied to the comparator input I2 or is drained away, no electric charge being then applied to this input;
the lateral output gate LOG83 forming pat of the LCTD83 is activated for the duration of the pulse P36 via the OR-gate M8 so that the electric charge (Qr/8, . . . , Qr/512) present under the third transfer electrode LTE83 of the LCTD83 (not shown) at the end of the time interval T35 is transferred under the output diode LOD83 from which this charge is supplied to the input I2 of the comparator COMP. As a consequence, the electric charge applied to the input I2 is equal to the following values for the segments S8 to S1 and depending on the fact that the input voltage Vin belongs to the quantums q9 to q16 (LOG73 activated) or q1 to q8 (LDG73 activated) of these segments:
______________________________________ S8 ##STR1##.. S2 ##STR2## S1 ##STR3##______________________________________
In each of these cases the condition of the output comp of the comparator COMP is 1 or 0 depending on the Vin belonging to the set of quantums q13-q16, q5-q8 or to the set of quantums q9-q12, q1-q4 of the corresponding segment. In the former case, the electric charge Qr/8, . . . , Qr/512 should be continued to be applied via the lateral output diode LOD83 to the comparator COMP during the remaining time intervals, whereas this charge should be removed in case the comparator output comp is on 0. For this reason, the condition of this output is registered in the D-flipflop DFF2 by the rear edge of the sampling pulse P35:
in case the comparator output comp is on 1 (quantums q13-q16, q5-q8) this flipflop DFF2 is triggered to its 1-condition whereby the AND-gate G18 is activated, so that the sampling pulses P37 and P38 are allowed to be applied to the LOG83 via this gate and the OR-gate M8;
when the comparator output comp is on 0 (quantums q9-q12; q1-q4) the D-flipflop DFF2 remains in its 0-condition so that the LOG83 is inhibited and the AND-gate G19 is activated, the above sampling pulses P37 and P38 being thus allowed to be supplied to the lateral drain gate LDG73 via this gate G19 and during the time intervals T37 and T38.
It follows from the above that the condition of Q-output b2 of the D-flipflop DFF2 indicates the value of the bit b2 of the quantum code b3b2b1b0. By the pulses 36 (FIG. 5) of the control pulse waveforms F1 to F3 and f1 to f3 the electric charges are then shifted in the CTD and in the LCTD73 to the LCTD103 so that at the end of the time interval T36 the contents of these charge transfer devices are as shown on FIGS. 7 to 11. For instance, when Vin belongs to one of the quantums q13-q16 of the segment S8, at the end of the time interval T36 the contents of the cells C7 to C10 are Qr/2, Qr/4, Qr/8, Qr/16, respectively, those of the cells LC7 to LC10 are Qr/4, Qr/8, Qr/16, Qr/16, respectively, and the electric charge applied to the input I2 of the comparator COMP is equal to Qr/2+Qr/4+Qr/8 (FIG. 7). For the other FIGS. 8 to 11 it is also supposed that the Vin belongs to one of the quantums q13-q16.
In a similar way, as described above, the value of the bit b1 of the quantum code is determined during the time interval T37 and stored in the D-flipflop DFF3. This bit is 1 for the quantums q15, q16; q11, q12; q7, q8; q3, q4 and is 0 for the other quantums. At the end of this time interval the contents of the charge transfer devices CTD and LCTD73 to LCTD103 are as indicated on FIGS. 7 to 11.
For instance, when Vin belongs to one of the quantums q15-q16 of the segment S8, at the end of time interval T37 the contents of the cells C7 to C10 are Qr/2, Qr/4, Qr/8, Qr/16, those of the cells LC7 to LC10 are Qr/4, Qr/8, Qr/16, Qr/32, respectively, and the electric charge applied to the comparator COMP is equal to Qr/2+Qr/4+Qr/8+Qr/16 (FIG. 7). For the FIGS. 8 to 11 it is also supposed that Vin belongs to one of the quantums q15-q16.
Finally, during the time interval T38 the value of bit bo of the quantum code b3b2b1b0 is determined as follows.
By the sampling pulse P38 (FIG. 5) generated shortly after the start of this time interval T38:
electric charges equal to half the electric charges stored in the cells C7 to C10 of the CTD at the end of the time interval T37 are laterally deviated therefrom and stored under the electrodes ALTE73 to ALTE103 of the cells LC7 to LC10 of the LCTD73 to the LCTD103, respectively, in a similar way, as described above, for the sampling pulse P34. This operation is without importance;
the LOG73, LOG83, LOG93, LDG73, LDG83 and LDG93 are activated or inhibited depending on the condition of the DFF1, DFF2 and DFF3;
the lateral output gate LOG103 forming part of the LCTD103 is enabled for the duration of the pulse P38 via the OR-gate M11 so that the electric charge (Qr/32, . . . , Qr/2048) present under the LTE103 of the LCTD103 at the end of the time interval T37 is transferred under the output diode LOD103 from which this charge is supplied to the input I2 of the comparator COMP. As a consequence, a total electric charge, such as Qr/2+Qr/4+Qr/8+Qr/16+Qr/32 for S8 is applied to this input I2 and the D-flipflop DFF4 is accordingly triggered in its 1-condition (q16, q14, q12, . . . , q2) or O-condition (q15, q13, . . . , q1) at the end of the pulse P38. This condition indicates the value of the bit b0 of the quantum code b3b2b1b0.
By the pulses 38 (FIG. 3) of the control pulse waveforms F1 to F3 and f1 to f3 the electric charges are then shifted in the CTD and in the LCTD73 to the LCTD103, but this has no effect on the condition of the D-flipflops DFF1 to DFF4. It should also be noted that the drain gate LDG103 is not used and that it has been provided for reasons of uniformity.
From the above, it follows that at the end of the time interval T38 the segment bis a2a1a0 are provided by the CTT, while the mantissa or quantum bits b3b2b1b0 are stored in the D-flipflops DFF1 to DFF4.
In connection with the above it should be noted that the ctd is not absolutely necessary. However, as well known, electric charges transferred in a charge transfer device suffer from a charge loss which is proportional to the number of stages of this device. By the presence of the ctd having a same number of stages as the CTD the Qin is also submitted to a charge loss before being compared in the comparator COMP with the charge transferred through the CTD. Thus, the effect of these charge losses is compensated to a certain extent.
The principles described above in connection with an analog-to-digital converter are also applicable for a digital-to-analog converter. Such digital-to-analog converter is in fact formed by the CTD and the gating means or control device associated thereto. Indeed, by introducing in the CTD electric charges corresponding to the values of the constituent bits of a digital input value and by suitably controlling the gating means associated to the CTD it is clear that it is possible to build up an output voltage corresponding to this digital value. It is also clear that the above described converter can be easily modified to operate according to the so-called μ-law.
Reference is now made to FIG. 12 which shows an analog-to-digital converter able to convert a positive or negative input voltage Vin to a digital value. It comprises two charge transfer devices ctd1 and ctd2 which are similar to the charge transfer device ctd of FIG. 1 and two charge transfer device CTD1 and CTD2 which are similar to the charge transfer device CTD of the same figure. The outputs of the ctd1 and the CTD1 are both connected to the input I1 of the comparator COMP, while the outputs of the ctd2 and the CTD2 are both connected to the input I2 of this comparator COMP. This converter is able to determine first the sign of an analog voltage to be converted and then the digital value corresponding to this voltage.
To determine the sign of an input voltage Vin a sum voltage Vin+Vb, Vb being a bias voltage, is also applied to the input il of the ctd1 and this bias voltage Vb is supplied to the input i2 of the ctd2. Consequently, the output comp of the comparator COMP becomes 1 or 0 depending on the Vin being positive or negative, respectively.
To obtain the digital value of the Vin the voltages applied to the converter to determine the sign are maintained, but the bias voltage Vb is further applied to the input I1 of the CTD1 while a voltage Vb+Vr/2 or Vb-Vr/2, Vr/2 being a reference voltage, is applied via a switch S to the input I2 of the CTD2 depending on the sign of Vin being positive or negative, respectively. Because the CTD1 and the CTD2 at their output provide a signal proportional to a voltage kVb and k(Vb+Vr/2), respectively, while ctd1 and ctd2 provide at their output a signal corresponding to Vin+Vb and Vb, respectively, k being a fraction of unity and is modified in a stepwise manner, e.g. k=1/2, 1/4, 1/8, . . . the signals applied to the inputs I1 and I2 of the comparactor COMP are proportional to Vin+(1+k)Vb and ±(kVr/2)+(1+k) Vb, respectively. Consequently, the output voltage of this comparator COMP is proportional to
Vin±(kVr/2)
so that the Vin is in fact compared with ±(kVr/2) as in the case of FIGS. 1 and 2.
In connection with the above it should be pointed out that the described charge transfer device CTD is very compact and could, for instance, be replaced by a structure including the following units:
a charge transfer device which includes at least 6 cells each able to realize a division by 2 and corresponding in fact to cells C1-C6 of the CTD and which is able to provide output signals corresponding to the segments S1 to S8. Obviously, it would also be ossible to replace such a charge transfer device by a plurality of charge transfer devices each providing an output signal corresponding to a distinct one of these segments.
four other charge transfer devices corresponding to the lateral charge transfer devices LCTD73 to LCTD103 of the CTD, but including at least 7, 8, 9 and 10 cells, respectively, each able to realize a division by 2 so that these devices are able to provide output signals corresponding to the fractions of the segments.
Finally, it should be noted that the above described converter can be considered as comprising:
a signal generator formed by the CTD and the associated control device, because this generator produces a reference voltage which is compared with Vin;
a comparator COMP wherein this reference voltage is compared with Vin.
This reference voltage comprises a decreasing staircase-shaped voltage which is generated by means of the cells C1 to C6 of the CTD in a raising and decreasing staircaseshaped voltage which is generated with the help of the cells C7 to C10 and which is superimposed in a constant voltage which is provided at the output of the cells C11-C16.
While the principles of the invention have been described above in connection with specific apparatus, it is to be clearly understood that this description is made only by way of an example and not as a limitation on the scope of the invention. | The signal generator comprises a charge transfer device providing an output signal having any desired shape so that it is particularly useful in an A/D or D/A converter. In this device charges are transferred under electrodes of which some are split in order to obtain charge portions which are then removed or transferred to the output of the device where they are added to or subtracted from previous charge portions to finally obtain a desired output signal. | 7 |
BACKGROUND OF THE INVENTION
1. Field of the Invention
This invention relates, generally, to the management of cords. More specifically, it relates to the management of electrical cords connected to devices not equipped with a means for organizing and storing the electrical cords connected to said devices.
2. Brief Description of the Prior Art
There are many electronic devices that require electrical cords and yet fail to include a means for organizing and storing their respective electrical cords when the devices are not in use. These cords can become tangled or are left in a messy heap, which can be a tripping hazard. Some attempt to wrap the electrical cord around the object itself, but the cord rarely remains securely wrapped.
Accordingly, what is needed is a versatile cord management device that can be attached to nearly any object and provides a structure for securely restraining an electrical cord and the cord's plug. However, in view of the art considered as a whole at the time the present invention was made, it was not obvious to those of ordinary skill in the field of this invention how the shortcomings of the prior art could be overcome.
All referenced publications are incorporated herein by reference in their entirety. Furthermore, where a definition or use of a term in a reference, which is incorporated by reference herein, is inconsistent or contrary to the definition of that term provided herein, the definition of that term provided herein applies and the definition of that term in the reference does not apply.
While certain aspects of conventional technologies have been discussed to facilitate disclosure of the invention, Applicant in no way disclaims these technical aspects, and it is contemplated that the claimed invention may encompass one or more of the conventional technical aspects discussed herein.
The present invention may address one or more of the problems and deficiencies of the prior art discussed above. However, it is contemplated that the invention may prove useful in addressing other problems and deficiencies in a number of technical areas. Therefore, the claimed invention should not necessarily be construed as limited to addressing any of the particular problems or deficiencies discussed herein.
In this specification, where a document, act or item of knowledge is referred to or discussed, this reference or discussion is not an admission that the document, act or item of knowledge or any combination thereof was at the priority date, publicly available, known to the public, part of common general knowledge, or otherwise constitutes prior art under the applicable statutory provisions; or is known to be relevant to an attempt to solve any problem with which this specification is concerned.
BRIEF SUMMARY OF THE INVENTION
The long-standing but heretofore unfulfilled need for an aftermarket cord management device is now met by a new, useful, and nonobvious invention.
The novel structure includes a pair of outwardly facing hooks disposed in a longitudinally spaced configuration. The hooks are preferable attached to a top surface of a flexible substratum. The bottom surface of the substratum includes adhesive, magnet(s), or fastener(s), thereby allowing the device to be secured to an object in need of a cord management device.
An embodiment includes a receptacle secured between the pair of outwardly facing hooks. The receptacle has two or more apertures adapted to receive prongs extending from the plug end of an electrical cord. In an embodiment, the receptacle is offset from the midline between the two hooks, such that a surface opposite of the surface containing the two or more apertures is closer to the nearest hook than the surface having the apertures.
An embodiment includes a catch and a receptacle. The catch has a bottom surface with an adhesive, fastener, or magnet for attaching the catch to an object. The receptacle has a side containing two or more apertures adapted to receive prongs extending from a plug end of an electrical cord, and a bottom surface with an adhesive, fastener, or magnet for attaching the receptacle to an object. The catch is preferably secured to an object in an orientation where the catch is facing the side of the receptacle having the two or more apertures.
An embodiment includes a flexible substratum on which the catch and receptacle are secured. The substratum in turn has a bottom surface with an adhesive, fastener, or magnet, thereby allowing the device to be secured to an object in need of a cord management device.
In an embodiment, the receptacle and the catch are manufactured as a single unit and adapted to separate into two components prior to use, using for example a perforated seam.
These and other important objects, advantages, and features of the invention will become clear as this disclosure proceeds.
The invention accordingly comprises the features of construction, combination of elements, and arrangement of parts that will be exemplified in the disclosure set forth hereinafter and the scope of the invention will be indicated in the claims.
BRIEF DESCRIPTION OF THE DRAWINGS
For a fuller understanding of the invention, reference should be made to the following detailed description, taken in connection with the accompanying drawings, in which:
FIG. 1A is a side view of an embodiment of the present invention.
FIG. 1B is a top view of an embodiment of the present invention.
FIG. 2 is a perspective view of the present invention secured to a cylindrical object, highlighting the flexibility of the present invention.
FIG. 3 is a perspective view of the substratum wrapping around a curved corner of an object to highlight the flexibility of the present invention.
FIG. 4 is a perspective view of an embodiment of the invention with a cord coiled around the longitudinally spaced hooks.
FIG. 5A is a perspective view of the present invention displaying the apertures in the receptacle.
FIG. 5B is a perspective view of the present invention displaying the apertures in the receptacle.
FIG. 6 is a perspective view of an embodiment of the present invention that uses a receptacle without the hooks.
FIG. 7 is a perspective view of an embodiment having a receptacle and a catch.
FIG. 8 is a perspective view of an embodiment having a receptacle and a catch.
FIG. 9 is a perspective view of an embodiment in which the receptacle and catch are sold as a single separable unit.
DETAILED DESCRIPTION OF THE INVENTION
In the following detailed description of the preferred embodiments, reference is made to the accompanying drawings, which form a part thereof, and within which are shown by way of illustration specific embodiments by which the invention may be practiced. It is to be understood that other embodiments may be utilized and structural changes may be made without departing from the scope of the invention.
The present invention is a novel apparatus attachable to any device for securing an electrical cord and plug. As depicted in FIG. 1 , an embodiment of the present invention includes substratum 102 having top surface 104 and bottom surface 106 . Substratum 102 is preferably flexible to conform to the surface over which the substratum is laid. As depicted in FIGS. 2 and 3 , the flexibility of substratum 102 allows the apparatus to easily conform to cylindrical objects and rounded edges.
Bottom surface 106 includes an adhesive, fastener, one or more magnets, or another securing instrument known to a person of ordinary skill in the art (not shown) to ensure that substratum 102 can be secured to an object. Bottom surface 106 may use a fastener that provides temporary or permanent affixation to the object on which substratum 102 is secured.
Top surface 104 includes first hook member 108 proximate to a first end of substratum 102 and second hook member 110 proximate to a second end of substratum 102 . Hooks 108 , 110 are preferably curved or angular structural members directed away from each other. In an embodiment, first hook member 108 and second hook member 110 are arranged in opposing configuration such that the hooks are convexly oriented from the perspective of the midpoint of the substratum. Hooks 108 , 110 in combination provide a structure about which cord 112 can be coiled as depicted in FIG. 4 .
In an embodiment, top surface 104 of substratum 102 also includes receptacle 114 . Referring to FIG. 5 , receptacle 114 includes apertures 116 configured to receive the prongs extending from the plug end of electrical cord 112 . As depicted in FIG. 5A , an embodiment of receptacle 114 includes two slot-shaped apertures 116 to receive a two-prong electrical plug. Alternatively, FIG. 5B provides an embodiment of receptacle 114 having three apertures 116 to receive a three-prong electrical plug. The current figures depict receptacle 114 having various apertures 116 consistent with the most common electrical plugs found in the United States. It is considered, however, that an embodiment of receptacle 114 may have different aperture designs for receiving any configuration of prongs extending from any type of electrical plug.
Receptacle 114 is preferably located between hooks 108 , 110 , but it is considered that receptacle 114 may be located outside of the two hooks. In addition, surface 114 a of receptacle 114 having apertures 116 preferably faces one of the hooks 108 , 110 to ensure that the cord's plug aligns generally with coiled cord 112 , as depicted in FIG. 4 .
In an embodiment, receptacle 114 is offset from the midpoint line between hooks 108 , 110 such that surface 114 b , the surface opposite of 114 a , is closer to the nearest hook than surface 114 a . This is best illustrated in FIG. 1 , wherein surface 114 b is closer to hook 108 than surface 114 a . As a result, ample room is provided to accommodate the plug end of cord 112 , which is typically a more rigid section of the cord.
In an embodiment, surface 114 b may be the surface of the receptacle that is oppositely disposed from substratum 102 to account for “low profile” plugs, i.e. prongs that are perpendicular to the longitudinal axis of the plug end of the electrical cord. In addition, surface 114 b may be any surface except for the object-facing surface, i.e. the surface mated to substratum 102 or simply the surface having the ability to attach to an object.
Referring now to FIG. 6 , an embodiment of the present invention includes receptacle 114 without hooks 108 , 110 . Receptacle 114 may rest atop a substratum or simply rely on a bottom surface 114 d having an adhesive, fastener, one or more magnets, or another securing instrument known to a person of ordinary skill in the art (collectively denoted by reference numeral 118 ) to ensure that receptacle 114 can be secured to an object. The method of securing receptacle 114 may be temporary or permanent.
Referring now to FIG. 7 , an embodiment includes receptacle 114 with catch 109 . In an embodiment, both receptacle 114 and catch 109 are secured to top surface 104 of a single substratum 102 or each is secured to their own independent substratum 102 . Alternatively, receptacle 114 and catch 109 may be used without a substratum and include their own respective securing instrument for attaching to a particular object.
Referring now to FIG. 8 , regardless of whether a receptacle 114 and catch 109 are used with substratum 102 , catch 109 preferably faces surface 114 a . As a result, cord 112 can be wrapped around an object between catch 109 and receptacle 114 , and the plug end can mate with receptacle 114 while catch 109 prevents cord 112 from sliding off of the object around which cord 112 is wrapped. Preferably, catch 109 is secured to an object proximate to the point at which cord 112 attaches to the object because electrical cords tend to loosen and slide from the end at which they attach to an object.
Alternatively, receptacle 114 can be secured to the object such that the longitudinal axis (axis extending between surface 114 a and 114 b ) of receptacle 114 is misaligned with the longitudinal axis of catch 109 . For example, receptacle 114 may be perpendicularly oriented with respect to catch 109 such that receptacle 114 shown in FIG. 8 would rotated 90-degrees in a clockwise direction prior to being secured to the object. As a result, the plug end of cord 112 would be parallel with the section of cord secured with catch 109 when the plug end mates with receptacle 114 .
Referring now to FIG. 9 , an embodiment includes receptacle 114 and catch 109 being manufactured and sold as a single unit to reduce costs. The unit preferably includes a perforated seam to allow the two objects to easily separate and be positioned as desired.
It should be noted that catch 109 and hooks 108 , 110 may have the same shape and thus capable of performing the same function.
In an embodiment, receptacle 114 is adapted to receive a portion of cord 112 rather than the prongs extending from the plug end of cord 112 . Instead of having prong apertures 116 , the alternative receptacle design has a cord receiving area adapted to receive and temporarily secure a cord. The alternative receptacle may have any shape and design known to a person of ordinary skill in the art such that the alternative receptacle is capable of temporarily securing a cord.
In addition, it should be noted that the optimal use of the device includes the following sequential steps for identifying an attachment location: (1) identifying a preliminary attachment location for the device, (2) securing the cord with the device, (3) adjusting the location of the device to ensure that the cord remains taught when secured, and (4) attaching the device at the adjusted location. These steps will ensure that the cord can be consistently secured to the device in an optimal location on the object that was lacking a cord management device.
Glossary of Claim Terms
Cord: is a flexible elongated object, typically containing an electrical conduit.
Hook: is an angular or curved object for holding or suspending something.
Outwardly Facing: is an orientation in which the curved or obtusely angled portion of the hooks face away from each other.
The advantages set forth above, and those made apparent from the foregoing description, are efficiently attained. Since certain changes may be made in the above construction without departing from the scope of the invention, it is intended that all matters contained in the foregoing description or shown in the accompanying drawings shall be interpreted as illustrative and not in a limiting sense.
It is also to be understood that the following claims are intended to cover all of the generic and specific features of the invention herein described, and all statements of the scope of the invention that, as a matter of language, might be said to fall therebetween. | A cord management device securable to objects lacking a cord management system. An embodiment includes a flexible substratum on which two outwardly facing hooks are secured in a longitudinally spaced manner. An embodiment further includes a receptacle adapted to receiving and temporarily house the prongs on an electrical cord. The flexible substratum preferably includes an adhesive, magnet or fastener to temporarily or permanently secure the device to objects. The device is thereby attachable to an object to aid in the securement of an electrical cord. | 7 |
CROSS REFERENCE TO PRIOR APPLICATIONS
[0001] The present invention claims the benefit of Provisional Patent Application Ser. No. 61/403,403 filed Sep. 14, 2010.
FEDERALLY SPONSORED RESEARCH
[0002] The present invention was made in the course of work under Contract No. N68335-09-C-0095 and Contract N68335-11-C-0204 both with the United States Navy and the United States Government has rights in the invention.
FIELD OF THE INVENTION
[0003] The present invention relates to optical connectors and in particular to fiber optic rotary connectors.
BACKGROUND OF THE INVENTION
[0004] Fiber Optic Rotary Joints allow optical signals carried by fiber optic cables to traverse a rotating interface (for example between the rotating and stationary parts of a piece of equipment). Fiber optics are used in many different applications, and are rapidly replacing traditional copper wiring for communications of signals. Solutions such as slip-rings exist to allow traditional electrical signals to traverse a rotating interface with low loss, but currently existing Fiber Optic Rotary Joints tend to have much higher losses than their electrical counterparts (in addition, existing Fiber Optic Rotary Joints tend to be more complex as well, containing many moving parts such as gear trains and de-rotation prisms—potentially impacting their usable life & reliability).
[0005] Applications are numerous, and include rotating radars antennas, photonic control of phased array antennas, instrumentation of rotating equipment (even turbo machinery), data transmission on aircraft, and many other systems. These types of equipment and sensors are used in both the commercial and defense arenas.
[0006] Traditional fiber optic rotary joints have usually been built with a de-rotation prism that aims the laser beam from the rotating side of the rotational interface at a consistent stationary point on the stationary side of said interface (see Ames 1992, 1994, etc and Iverson 1978). This de-rotation prism (typically a Dove or Pechan prism) must rotate at ½ the rotational rate of the rotating half of the joint or alternatively can be thought of as rotating at an average of the speed of the two halves (in relative rotation sense). Because of this half speed rotation, these fiber optic rotary joints typically require a reducing gear train and a number of associated bearings, introducing additional sources of misalignment, wear, and failure modes. This patent proposes to utilize magnetic gears (which have been known for over a century—see Armstrong, 1901, Faus 1940), and potentially magnetic bearings as well to essentially suspend these de-rotation optics in mid air, and avoid these concerns—Magnets have actually been used in fiber optic rotary joints that do not include de-rotation optics (such as Spencer & Oliver, 1988), but to the best of our knowledge, magnetic gears and bearings have never been employed with de-rotation optics, which will allow many more channels to pass through the rotary joint simultaneously.
[0007] Magnetic gears have been known for many years. Early examples are Faus, U.S. Pat. No. 2,243,555; Iverson, U.S. Pat. No. 4,109,998; and Spencer & Waverly U.S. Pat. No. 4,725,116.
[0008] What is needed is a better fiber optic rotary joint.
SUMMARY OF THE INVENTION
[0009] Applicant has invented a novel approach to Fiber Optic Rotary Joints that relies on special collimation technology, and a K-Mirror de-rotation mechanism. This new Fiber Optic Rotary Joint has the potential to exhibit higher channel counts, lower loss, and higher reliability than competing technologies. In addition, it is bi-directional, wavelength independent, and can likely operate at higher rotational speeds than competing approaches.
[0010] The fiber optic rotary connector of the present invention provides communication between a first fiber optical bundle and a second fiber optical bundle rotating relative to said first bundle. The fiber optic rotary connector includes a K-mirror comprised of at least three mirror components and a set of gears adapted to rotate said K-mirror at a rotation rate equal to one half of the second bundle rotation rate. In a preferred embodiment the set of gears is a set of magnetic gears. And in another preferred embodiment the set of gears is a set of mechanical gears. Normally the first fiber optic bundle is stationary, but it may be rotating at a slower rate than the second bundle. In preferred embodiments the K mirror is comprised of three flat mirrors and two of the flat mirrors are positioned at about 30 degrees relative to the third flat mirror.
[0011] Applications are numerous, and include photonic control of rotating phased array antennas, instrumentation of rotating equipment (including turbo machinery), data transmission on aircraft, and many other systems. These types of equipment and sensors are used in both the commercial and defense arenas. In particular, for this topic, there is a strong interest in true time delay lines for photonic control of phased array antennas. One particularly nice benefit of this technology is the potential for large weight savings enabled by replacing heavy copper coaxial cables with lightweight fiber optic lines. Some of the particular motivations for this work include:
Moving to more fiber based devices & sensors Better Noise Floor than electrical cabling Immunity to Electromagnetic Interference, Eavesdropping, & Jamming Much Lower Weight than Large Numbers of Coaxial Cables Dramatically Increased bandwidth as compared to electrical cabling True Time Delay to Avoid Wavelength Dependent Angular Change & Squint Desire for lower loss, higher reliability, & more rugged solutions than existing FORJ's
BRIEF DESCRIPTION OF THE DRAWINGS
[0019] FIG. 1 is a first prospective view showing features of a preferred embodiment of the present invention.
[0020] FIG. 2 is a second prospective view showing features of a preferred embodiment of the present invention.
[0021] FIG. 3 is an exploded view showing features of a preferred embodiment of the present invention.
[0022] FIG. 4 shows a lens design for coupling a fiber output from a first optical fiber to a second optical fiber.
[0023] FIG. 5 shows a technique for optimizing coupling of light into a collimated beam.
[0024] FIG. 6 illustrates important features of the present invention.
[0025] FIG. 7 illustrates a relationship between optical path length and K-mirror angle.
[0026] FIG. 8 shows a square pattern of four collimation lenses.
DETAILED DESCRIPTION OF PREFERRED EMBODIMENTS
[0027] Applicant's fiber optic rotary joint concept is depicted in FIGS. 1 , 2 and 3 . The figures respectively show an upper view, a bottom view and an exploded view. Shown on the drawings are rotating fiber bundle 4 , a K mirror 6 rotating at half speed and a fixed bundle 8 . A set 10 of four magnetic gears set the half speed of the k mirror. This new K-Mirror concept utilizes mirrors rather than Pechan or Dove prisms, so that many wavelengths can be passed through the same Fiber Optic Rotary joint, and relies on magnetic gears to avoid the complexity and potential hit to reliability inherent in most traditional de-rotation base rotary joints. By rotating the K-Mirror portion 2 of this rotary joint at half the speed of rotation (or more generally speaking the average between the speed of the two halves), the alignment between input and output beams is maintained regardless of position. This half speed rotation is accomplished by non-contact magnetic gears, avoiding friction, wear, backlash, lubricants, and potential failures possible with traditional de-rotation based designs.
[0028] Some of the potential advantages of this approach include:
The Ability to Accommodate Many Simultaneous Channels (up to about 128 with Trex's CrossFiber collimator arrays)—Potentially more in the future Extremely Low Friction/Wear—High Reliability Wavelength Independence—K-Mirrors allow wavelength independent de-rotation (as opposed to Dove Prism or Pechan Prism) High Reliability Could Potentially Employ Magnetic Bearings in the future as well
Testing the Design
[0034] In a prototype design, the rotary joint is vertically clamped to a rigid tower. A drive motor attached to the tower is used to directly drive the rotation of the rotary joint. This external motor may be coupled through the idler magnetic gear shaft. A stepper or servo motor with an encoder for feedback will likely be used. This will enable precise positioning of the rotary joint angle for detailed examination of rotationally dependent losses.
[0035] There are two complementary approaches that may be used for configuring the rotary joint for testing. Both eliminate the need for externally coupling to the fibers on the rotating side of the rotary joint, greatly simplifying the overall test bed design.
Loopback Configuration
[0036] In the loopback configuration, input signals are coupled into half of the available channels on the static side of the rotary joint. On the rotating side, the input channels are looped back into the unused set of channels, making sure that none of the signals are looped back into an adjacent channel. After looping back, the input signals pass though the rotary joint as second time and are passed out though the stationary side of the rotary joint to the external test equipment.
[0037] In this configuration, the measured insertion loss is the cumulative sum of the losses of both the forward and return paths. The single channel performance can be extracted by performing three sets of measurements. For three given rotary joint channels, A, B, and C, the forward+return configurations are A+B, A+C, and B+C. The single channel performance can be extracted by adding any two measurements and subtracting the third. For example,
[0000] ( A+B )+( A+C )−( B+C )=2 A
Retro-Reflector Configuration
[0038] In the retro-reflector configuration, each rotary joint channel on the rotating side is coupled to a fiber retro-reflector. Input signals pass twice through the same channel and are returned on same input fiber. An optical circulator installed on the input fiber is used to couple the signal from a laser source into the fiber and the return signal into a calibrated photo-detector. This configuration has the advantage of enabling testing of all rotary joint input channels either sequentially or in parallel without having to open the environmental chamber. It also has the advantage of mixing multiple channels in a single measurement. The main disadvantage is that back reflection is not distinguished from signal returned from the retro-reflector, so high Optical Return Loss (ORL) could artificially improve insertion loss measurement results. However, this can be mitigated by performing separate ORL measurements.
Optical Return Loss Configuration
[0039] For Optical Return Loss measurements, the rotary joint output connectors on the rotating side will be terminated to prevent back reflection. This will enable direct ORL measurements using a Back Reflection Meter.
Test Equipment
[0040] All test equipment is remotely located external to the environmental chamber. The optical input signal will be provided by a fiber coupled laser. Lasers at 850 nm, 1310 nm, and 1550 nm are included in the conceptual design to enable testing at each wavelength. The output signal will be detected using a calibrated 1 R photo-detector. Typical photo-detectors that are sensitive over the range of interest (such as Germanium or InGaAs detectors) have significant dark current. This would need to be subtracted for DC signal measurements. An alternative approach that we will explore is to modulate the amplitude of the optical input signal (up to 100 kHz modulation frequency) and then read out the detected signal using a lock-in amplifier referenced to the same frequency. This approach enables rejection of signals at other frequencies, including DC. Thus any offset due to dark current and/or stray light is rejected from the measurement. The use of a lock-in amplifier also greatly improves the signal to noise ratio of the measurement, which is beneficial for small signal measurements such as crosstalk.
[0041] Applicant analyzed, designed, and built a prototype four-channel multimode fiber optic rotary joint. This rotary joint approach converts the signal from each input fiber optic channel to a collimated free-space beam. The beam is de-rotated using a k-mirror, and then coupled back into fibers on the other side of the rotary joint. The optical and mechanical design requires attention to several key areas. These include:
Fiber selection Lens selection Free space optical path length Magnetic gear design
Fiber and Lens Design Considerations
[0046] The selection of the multimode fiber for use in the prototype required consideration of the fiber diameter, and numerical aperture. Both of these parameters are subject to multiple constraints imposed by the overall system design.
[0047] Ordinarily to maximize the coupling of light into the fiber, the fiber diameter should be as large as possible. There is however a second constraint on the fiber diameter. The output of the bare fiber end is to be collimated by placing a lens one focal length away. If the fiber end was an ideal point source, the beam could be perfectly collimated. However, since the fiber diameter is finite in size, the collimated beam will have a divergence angle that is proportional to the fiber diameter. FIG. 4 depicts the collimation of the fiber output and subsequent coupling of the collimated beam into a second fiber using a two-lens system.
[0048] In FIG. 4 the output fiber (left side) has a radius of r 1 and its output half-angle is θ 1 . The output half angle is a characteristic of the fiber and is typically specified as the numerical aperture (NA), which is equal to sin θ 1 in air. The divergence angle of the collimated beam is determined by the ratio of the focal length of the collimating lens and the radius of the fiber.
[0000]
θ
D
=
r
1
f
1
[0049] Therefore, the divergence decreases with decreasing fiber radius and increasing lens focal length.
[0050] In order to maximize the coupling of light into the collimated beam, the numerical aperture of the lens must be at least as large as the NA of the fiber as shown in FIG. 5
[0051] The lens NA is also equal to sine. This fixes the ratio of the lens focal length to its diameter.
[0000]
NA
=
sin
θ
=
sin
(
tan
-
1
D
2
f
)
[0052] The f-number, N of the lens is defined as f/D. Therefore, using the small angle approximation, the relation reduces to:
[0000]
N
≈
1
2
·
NA
[0053] Optimizing the coupling of the collimated beam into the output fiber requires that the collecting lens have a numerical aperture at most the same as that of the output fiber. If the same fiber is used for input and output, then the optimal configuration is to use symmetric lenses with clear apertures equal to the fiber clear aperture.
[0054] The fiber-lens interactions discussed thus far impose constraints on the fiber and lens selection based on the acceptable collimated beam divergence. To determine what convergence is acceptable, the free space optical path length of the system must be known. For this initial prototype, it is reasonable to limit the expansion of the beam diameter to approximately 1.5× the initial diameter. Assuming a Gaussian intensity profile, approximately 2σ (or 95%) would be collected using a symmetric lens to couple the light into the output fiber (assuming the beam is visible to approximately 3σ (99.7%)).
K-Mirror Design Considerations
[0055] The optical path length of the prototype is determined primarily by the path length through the k-mirror. FIG. 6 shows the optical path though a k-mirror. The mirrors will be denoted as M 1 , M 2 , and M 3 from left to right along the optical path. As can be seen in the figure, the angles of mirrors M 1 and M 3 determine the placement of mirror M 2 . At shallow angles to the incident beam, the distance to mirror M 2 is very small. However, the clear aperture (CA) of the k-mirror becomes very small as well. In order to maintain a minimum CA, the length, d, of the mirrors must be increased. Conversely at steep angles, mirror M 2 must be placed far away to return the beam to the original optical axis when reflected back to M 3 . Note that the angles of mirrors M 1 and M 3 must be symmetric and are limited to the range between 0° and 45° (at 0° the mirror is parallel to the incident beam and at 45° the beam is reflected at a 90° angle).
[0056] The CA is typically fixed by the rest of the system, therefore optical path length through the k-mirror as a function of mirror angle (M 1 and M 3 ) can be determined for a given fixed CA. The relation between h and θ can be determined geometrically and is given by:
[0000]
tan
(
2
θ
)
=
h
l
2
→
h
=
l
2
tan
(
2
θ
)
[0057] The clear aperture is also related to the mirror angle by:
[0000] CA=d sin θ
[0058] From entry into the k-mirror, the optical path length can then be calculated
[0000]
Path
Length
=
2
(
d
2
cos
θ
+
h
sin
(
2
θ
)
)
[0059] Since the clear aperture is related to the mirror angle, the path length can be recast in terms of the CA
[0000]
Path
Length
=
2
[
d
·
sin
θ
2
·
tan
θ
+
l
2
·
tan
(
2
θ
)
tan
(
2
θ
)
cos
(
2
θ
)
]
[0060] Assuming no space between mirrors M 1 and M 3 (i.e. 1=d cos θ). In terms of CA, this yields:
[0000]
l
2
=
CA
2
tan
θ
[0061] Substituting in the relations for CA, the path length is now
[0000]
Path
Length
=
2
[
CA
2
·
tan
θ
+
CA
·
cos
(
2
θ
)
2
·
tan
θ
]
=
(
1
+
cos
(
2
θ
)
tan
θ
)
·
CA
[0062] The path length through the k-mirror as a function of mirror angle is shown in FIG. 8 . The minimum in path length of 5.196 CA is found to occur at a mirror angle of 30°.
Prototype Design
[0063] In the current prototype design, the multimode fiber was chosen to have a diameter of 0.25 mm and a numerical aperture of 0.5. This dictated that the lens also have a numerical aperture of 0.5 (f/#=1.0). A 0.5 inch (12.7 mm) diameter plastic aspheric lens with a 0.5 inch focal length was selected. The prototype was designed for four-channel operation. With four collimation lenses placed in a square pattern with 0.030 inch separation, the system clear aperture was set at 1.25 inches as shown in FIG. 8 .
[0064] The k-mirror was designed to minimize the free space optical path length. The angles mirrors M 1 and M 3 were set at 30°. For a CA of 1.25 inches, this yields a path length of 6.5 inches within the k-mirror. For the k-mirror assembly 31×77 mm, wave front surface mirrors were selected to closely match the clear aperture of the rest of the system.
[0065] The collimated beam divergence angle calculated for the selected components is 0.564°. At a path length of 6.5 inches, the beam diameter will have expanded to 0.628 inches from an initial diameter of 0.5 inches.
[0066] The relative rotational position of the upper collimator and the k-mirror are maintained at a 2:1 ratio by use of magnetic gears as shown in FIGS. 1 , 2 and 3 . The upper magnetic gear set attached to the upper collimator has 18 poles and a gearing ratio of 1:1. The lower set of magnetic gears has a gearing ratio of 2:1 with 24 poles on the gear attached to the k-mirror and 12 poles on the external gear. The upper and lower external gears are mounted to the same shaft, which maintains the relative position of the two sets. It should be noted that the use of magnetic gears has significant advantages over traditional gears in this application. Primarily, there is no backlash, and the contactless design requires no lubrication in the vicinity of the optics.
Description of System Alignment Procedure
[0067] System alignment was critical and consisted of aligning all rotational axes and the k-mirror optical output to a primary optical reference axis. This process is aided by use of a long lever arm at the output. In this experiment, a lever arm of approximately 2 meters was used. This was accomplished by placing a turning flat at the bottom of the de-rotation assembly to redirect the output beam parallel to the optical table. Two additional fold mirrors were used to position the end of the lever arm at an IR target within easy view from the rotary joint.
[0068] After removal of the k-mirror subassembly (leaving the rotating X-Y and kinematic mounts in place), the reference axis was defined by adjusting the X-Y and tip/tilt of the fiber launch rotating subassembly to eliminate precession of the output beam. The fiber launch global tip/tilt was also adjusted to make the beam vertical. The IR target position was then adjusted to center reference marker on the beam. This point was then used to define the output reference for the rest of the alignment procedure.
[0069] Once the reference axis was defined, an IR target was placed on the k-mirror kinematic mount the rotating X-Y position of the k-mirror mount was adjusted to eliminate visible precession. The global X-Y was then adjusted to center the rotational axis on the reference beam. The k-mirror was then reinstalled and the IR target was placed at the top of the k-mirror cage. The rotating assembly tip/tilt and global tip/tilt were used to respectively eliminate precession and center the rotational axis at the top of the k-mirror. At this point the de-rotation assembly was coarsely aligned to the reference axis.
[0070] The k-mirror, consisting of 3 flat mirrors (M 1 , M 2 , and M 3 in the order from top to bottom) was coarsely aligned next. The vertical angle of M 1 and M 3 were set to approximately +30° and −30° to the reference axis, respectively. The exact angle is not critical as long as it is large enough to provide a reasonable clear aperture and small enough to strike near the center of M 2 in a reasonable distance. The IR target was placed at M 2 and the position of M 2 was then adjusted so that the beam reflected by M 1 struck near its center. The horizontal angle of M 1 was adjusted to center the spot horizontally on M 2 as well. The IR target was then placed at the bottom of the rotating k-mirror assembly and the tip/tilt of M 2 was adjusted to center the beam on the rotational axis. Lastly, the tip/tilt of M 3 was adjusted to minimize the precession at the far target.
[0071] Fine alignment of the system was then performed as an iterative process. The global tip/tilt of the de-rotation assembly was adjusted to center the precession of the beam at the far target. An IR target was then placed at the top of the k-mirror and the de-rotation assembly tip/tilt was adjusted to re-center the beam on the rotation axis. The k-mirror alignment described in the preceding paragraph was then repeated. This process was iterated several times until the precession at the far target was minimized and checks of the rotational axis at the top and bottom of the k-mirror confirmed alignment to the reference beam. Further improvements to alignment could be realized by use of a longer lever arm and more iterations of this process.
[0072] The k-mirror has significant alignment flexibility. The positions and angles of the 3 mirrors can span a significant range. The only absolute requirement is that the mirrors be adjusted to bring the output back on to the axis of the input beam. A secondary effect of asymmetric angles in M 1 and M 3 is a reduction in the clear aperture. Therefore the positions and angles M 1 and M 3 should be near symmetric to minimize this effect.
[0073] Coupling losses observed in Phase I experiments are likely due to residual misalignment of the system. The best alignment achieved yielded approximately 0.5 mm of precession at 2 meters and thus approximately 0.25 milliradians misalignment. This could be further improved using a longer lever arm and additional alignment iterations.
Variations
[0074] The reader should understand that the present invention is not limited by the above described embodiments and that the scope of the invention should be determined by the appended claims and their legal equivalence. | A fiber optic rotary connector providing communication between a first fiber optical bundle and a second fiber optical bundle rotating relative to said first bundle. The fiber optic rotary connector includes a K-mirror comprised of at least three mirror components and a set of gears adapted to rotate said K-mirror at a rotation rate equal to one half of the second bundle rotation rate. In a preferred embodiment the set of gears is a set of magnetic gears. And in another preferred embodiment the set of gears is a set of mechanical gears. Normally the first fiber optic bundle is stationary, but it may be rotating at a slower rate than the second bundle. In preferred embodiments the K mirror is comprised of three flat mirrors and two of the flat mirrors are positioned at about 30 degrees relative to the third flat mirror. | 6 |
TECHNICAL FIELD
The present invention relates to power system control technologies, in particular to a converter bridge arm suitable for high-voltage applications and an application system thereof. The present invention is mainly applied in smart grids (e.g. ultrahigh voltage power transmission, AC-DC-AC conversion power electronic transformers, and high-voltage grid-connected power generation of new energies), high-power electrical drive (high-voltage, medium-voltage variable frequency drive), and electric traction.
BACKGROUND
High-voltage high-power converters have always been a key technology for the application of power electronics in power systems and high-power electrical drive. A switch series connection technology or a multilevel technology must be employed in the case that the voltage required in practical applications exceeds the withstanding voltage of a single power semiconductor device. The withstanding voltage of conventional high-voltage power semiconductor devices is approximately 1-5 kV, and among them, those ordinary devices IGBT that are commonly used only have a withstanding voltage of 1200V approximately. Thus, use of a device having a withstanding voltage of 3400V could lead to much higher cost than use of those conventional high-voltage power semiconductor devices; even if a device having a higher withstanding voltage is used regardless of its cost, the high-voltage operating requirements of a power system cannot still be met without using the switch series connection technology or the multilevel technology. On the other hand, continuous improvement of the withstanding voltage level of these devices makes it possible that switching frequency becomes lower and lower, thereby increasing the volume and weight of a converter system.
For a high-voltage converter circuit, direct series connection of devices is the last resort. This scheme indeed brings the advantage of a relatively simple structure, but an extremely high change rate in switching voltage could still lead to the problems in the aspect of electromagnetic compatibility, and also degrade the reliability of load equipment and shorten the service life thereof. Furthermore, the voltage sharing control method for devices will be more difficult as the number of series connections rises, and requires a larger withstanding voltage margin, therefore, it can be concluded that the switch series connection technology is unsuitable for independent use in the power system.
As a result, it stands to reason that a multilevel circuit is used in the converter. The multilevel circuit can be applied to DC/AC, DC/DC, AC/DC and AC/AC, and for ease of description, illustration is mainly made below from an inversion (i.e. DC/AC) view.
(1) Power Switch
Reverse conducting switch is commonly used in a voltage source converter, and it may be composed of two independent devices: power semiconductor switch and antiparallel power diode and may also be an integrated device; for simplicity, it is herein referred to as switch (K, its symbol is shown in the circuit of FIG. 3 ), and the positive and negative poles of the switch are in directions that are just opposite to the polarities of the antiparallel power diode. K that is commonly used includes insulated gate bipolar transistor (IGBT) and power metal-oxide-semiconductor field effect transistor (Power MOSFET) device with the antiparallel power diode, and may also be thyristor, integrated gate commutated thyristor (IGCT), junction field effect transistor (Power JFET), and other novel devices like various types of silicon carbide power switches. In the circuit of FIG. 10 , Power MOSFET is applied in K. A combined switch, which is formed by series connection of a plurality of reverse conducting switches, can still be perceived as a switch in the present invention.
(2) Several Important Multilevel Converter Circuits that Exist at Present
The first circuit: diode clamped multilevel circuit, which was first seen in the IEEE IAS conference paper (A. Naba) in 1980;
The second circuit: flying capacitor damped multilevel circuit, which was first seen in the IEEE PESC annual meeting paper (T. A. Meynard) in 1992;
The third circuit: unified clamped multilevel circuit, which was first seen in the IEEE IAS conference paper (F. Z. Peng) in 2000;
The fourth circuit: cascade multilevel circuit, which was first seen in the PESC conference paper (M. Marcheson) in 1988.
The first and second circuits have the major problem that: the complexity of these circuits is rapidly raised due to increase of the level number, the number of components and devices times fast (the former is switch devices and clamped diodes, and the latter is clamped capacitors); more seriously, impact from distributed inductance and control difficulty are also increased remarkably; in fact, applications of seven levels or above are rarely seen.
The third circuit has the major problem that increase of the level number results in faster rise of the number of components and devices in this circuit than the previous two circuits, and this circuit has not been put into practical application in industry yet. As a matter of fact, the third circuit is only theoretically meaningful, and the previous two circuits are special cases of the third circuit, respectively.
The foregoing shortcomings in the first, second and third circuits are not found in the fourth circuit; this circuit is capable of voltage balancing by means of an independent power source, is easy to realize modularization (H-bridge is served as unit module) and has been widely applied in medium-voltage variable frequency conversion, and its alternating current voltage is within 10 kV in general. Typically, a set of independent power source needs to be provided for every unit in the fourth circuit, so a quite complex structure of the main transformer of the apparatus is caused, which further places a limitation upon further rise of the level number.
In the field of reactive applications (e.g. one of the flexible power transmission devices for power system: STATCOM), the fourth circuit is free from the limitation of multiple paths of independent power sources, however, with the increase of the level number, there are still great challenges in voltage sharing problems.
(3) The Fifth Circuit, Balance Cascade Multilevel Converter
It is also known as “self-balance cascade multilevel”, its capability of realizing automatic voltage sharing of the converter units is the most prominent feature of the new circuit and was made public in the doctoral thesis of Zhejiang University (F. Zhang) 2006, and in fact, this circuit is a variant of the third circuit. However, this circuit also has a few problematic issues: low-voltage power supply and high-voltage output, so it is unsuitable for common high-voltage applications; energy needs to be transferred among units many times, making efficiency a great problem; during balance actions, there is no restriction mechanism for balancing current impact; and all circuit elements needs to be closely connected as a whole, causing a large difficulty in achieving modular combined manufacturing.
(4) The Sixth Circuit, Modular Multilevel Converter (MMC)
This circuit was first seen in the IEEE PowerTech Conference paper (A. Lesnicar and R. Marquardt) in 2003 The number of devices required in this circuit is linearly proportional to the level number, and this circuit is also suitable for modular manufacturing and particularly for ultrahigh-voltage applications (e.g. HVDC Light) in power system, however, voltage sharing control for its modules is still quite problematic, so its practical applications are rarely seen.
SUMMARY OF THE INVENTION
Like symbols in this disclosure refer to like electronic elements and/or connecting terminals. Given the advantages and disadvantages of the multilevel circuits above, the present invention proposes a free telescopic arm-based multilevel converter topology and various converter circuits formed therefrom in accordance with the special requirements of high-voltage high-power converter systems and by reference to the crawling bionics principle of silkworm, and in such circuits, the problems of modularization implementation and electric stress balancing among modules are taken into full consideration.
The body of silkworm is made up of many segments, silkworm needs to constantly shrink and stretch its body during a crawling process. It is easy to find that there is a change in the thickness of every segment instead of the volume during the shrinkage and stretching of silkworm. The converter bridge arm that acts as bionic target can be considered as a pair of connected silkworms, the upper and lower two telescopic arms are respectively corresponding to one of the silkworms, and each converter unit in the telescopic arms is corresponding to one segment of silkworm body.
Regulation for the neutral point potential of the bridge arm is achieved by regulating the switches in the converter units of the telescopic arms, and during this regulation process, the energy storage level of each unit does not change suddenly, but the terminal voltage of the unit can change fast. In the event that the terminal voltage (obtained by series overlap of the terminal voltages of a plurality of units) and the energy of the telescopic arm are corresponding to the length and volume of silkworm respectively, it can be seen that regulation for the neutral point potential is quite like silkworm's telescopic action and the regulation process is just like shrinkage or stretching of the telescopic arm. Change of the neutral point is promoted by complementary shrinkage or stretching of the two telescopic arms together. And based on this principle, a brand-new high-voltage converter circuit can be constructed.
The sixth circuit above is actually a topology that is in conformity with this telescopic arm concept, but in the MMC circuit, only a half-bridge circuit is used as the converter units, so the circuit cannot realize automatic voltage sharing for the units and cannot be used in an AC/AC converter circuit either.
To solve the technical problems, provided in the present invention is a converter bridge arm suitable for high-voltage applications, which includes an energy storage capacitor C and a plurality of reverse conducting switches; the converter bridge arm is formed by series connection of an upper telescopic arm Bu, a lower telescopic arm Bd and an inductor(s) Lb, wherein the upper telescopic arm Bu and the lower telescopic arm Bd are respectively formed by cascading connection of a plurality of symmetrical units.
The symmetrical unit is composed of a first switch K 1 , a second switch K 2 , a third switch K 3 , a fourth switch K 4 and an energy storage capacitor C; wherein, the first switch K 1 and the second switch K 2 as well as the third switch K 3 and the fourth switch K 4 are connected in series respectively; the positive terminal of the first switch K 1 is connected with the positive terminal of the third switch K 3 to serve as a positive terminal p* of the unit, and the negative terminal of the second switch K 2 is connected with the negative terminal of the fourth switch K 4 to serve as a negative terminal n* of the unit; the energy storage capacitor C is connected between the positive terminal p* and the negative terminal n*; the junction between the first switch K 1 and the second switch K 2 is a second cascading connection terminal Z 12 of the unit, and the junction between the third switch K 3 and the fourth switch K 4 is a fourth cascading connection terminal Z 22 of the unit.
The cascading connection mode of the plurality of symmetrical units is as follows: between two adjacent units, the fourth cascading connection terminal Z 22 of the former unit is connected with the second cascading connection terminal Z 12 of the latter unit;
The upper and lower terminals of the bridge arm are terminals P and N of the bridge arm, respectively;
In the units at the outer sides of the two ends of the upper telescopic arm Bu and the lower telescopic arm Bd, the positive terminals p* and the negative terminals n* are led out to serve as auxiliary terminals of the converter bridge arm; the second cascading connection terminal Z 12 is taken as terminal p and the fourth cascading connection terminal Z 22 is taken as terminal n, and the terminals p and n are arranged in a direction consistent with the terminals P and N of the converter bridge arm;
The neutral point of the bridge arm, i.e. terminal Ac, is led from the connection wire between the terminal n of the upper telescopic arm Bu and the terminal p of the lower telescopic arm Bd; and the inductor(s) Lb is(are) any of the following forms:
(1) There is one inductor Lb, which is located at any position of the series connection branch of the upper telescopic arm Bu and the lower telescopic arm Bd;
(2) There are two inductors Lb, which are respectively located at the two sides of the terminal Ac on the series connection branch of the upper telescopic arm Bu and the lower telescopic arm Bd; and
(3) There are a plurality of inductors Lb, which are respectively located in the various symmetrical units.
As an application of the foregoing converter bridge arm, the present invention proposes that: an AC voltage regulator is composed of one or a plurality of converter bridge arms;
In the case that the AC voltage regulator is composed of one converter bridge arm, the terminals P and N of the converter bridge arm constitute an alternating current port and the terminals Ac and N constitute another alternating current port, in this way, a single-phase electronic voltage regulator is formed; or,
In the case that the AC voltage regulator is composed of a plurality of converter bridge arms, a multiphase alternating current port is led from the terminals P and N of each of the converter bridge arms in accordance with a polygon or star connection method, and another multiphase alternating current port is led from the terminal Ac of each of the converter bridge arms, in this way, a multiphase AC/AC electronic voltage regulator is formed.
On the basis of the same implementation principle, the present invention proposes a modified converter bridge arm, which includes an energy storage capacitor C and a plurality of reverse conducting switches; the converter bridge arm is formed by series connection of an upper telescopic arm Bu, a lower telescopic arm Bd and an inductor(s) Lb, wherein the upper telescopic arm Bu and the lower telescopic arm Bd are respectively formed by cascading connection of a plurality of units; and the unit is any one or two of the balance asymmetrical unit or the balance symmetrical unit;
The balance asymmetrical unit is composed of: a first switch K 1 , a second switch K 2 , a third switch K 3 , a fourth switch K 4 and an energy storage capacitor C; wherein, the first switch K 1 and the second switch K 2 as well as the third switch K 3 and the fourth switch K 4 are connected in series respectively; the positive terminal of the first switch K 1 is connected with the positive terminal of the third switch K 3 to serve as a positive terminal p* of the unit, and simultaneously, this terminal is also a first cascading connection terminal Z 11 of the unit; the negative terminal of the second switch K 2 is connected with the negative terminal of the fourth switch K 4 to serve as a negative terminal n* of the unit, and simultaneously, this terminal is also a fourth cascading connection terminal Z 22 of the unit; the two terminals of the energy storage capacitor C are connected with the first cascading connection terminal Z 11 and the fourth cascading connection terminal Z 22 , respectively; the junction between the first switch K 1 and the second switch K 2 is a second cascading connection terminal Z 12 of the unit, and the junction between the third switch K 3 and the fourth switch K 4 is a third cascading connection terminal Z 21 of the unit.
The balance symmetrical unit is composed of: a first switch K 1 , a second switch K 2 , a third switch K 3 , a fourth switch K 4 , a filth switch K 5 , a sixth switch K 6 , a seventh switch K 7 , an eighth switch K 8 and an energy storage capacitor C; wherein, the first switch K 1 is connected with the second switch K 2 in series, and the junction therebetween is a first cascading connection terminal Z 11 of the unit; the third switch K 3 is connected with the fourth switch K 4 in series, and the junction therebetween is a third cascading connection terminal Z 21 of the unit; the fifth switch K 5 is connected with the sixth switch K 6 in series, and the junction therebetween is a second cascading connection terminal Z 12 of the unit; the seventh switch K 7 is connected with the eighth switch K 8 in series, and the junction therebetween is a fourth cascading connection terminal Z 22 of the unit; the positive terminals of the first switch K 1 , the third switch K 3 , the fifth switch K 5 and the seventh switch K 7 are connected to serve as a positive terminal p* of the unit, and the negative terminals of the second switch K 2 , the fourth switch K 4 , the sixth switch K 6 and the eighth switch K 8 are connected to serve as a negative terminal n* of the unit and the two terminals of the energy storage capacitor C are connected with the positive terminal p* and the negative terminal n*, respectively;
The cascading connection mode of the plurality of units is as follows: a connection relationship of two groups of cascading connection terminals exists between two adjacent units, which is specifically as follows: the third cascading connection terminal Z 21 of the former unit is connected with the first cascading connection terminal Z 11 of the latter unit, and the fourth cascading connection terminal Z 22 of the former unit is connected with the second cascading connection terminal Z 12 of the latter unit; wherein, connection of one group of cascading connection terminals is implemented through an inductor Ls or a resistor R or through a parallel circuit of the inductor Ls and the resistor R, and connection of the other group of cascading connection terminals is implemented in a direct way;
In the units at the outer sides of the two ends of the upper telescopic arm Bu and the lower telescopic arm Bd, the positive terminals p* and the negative terminals n* are led out to serve as auxiliary terminals of the converter bridge arm; the second cascading connection terminal Z 12 is taken as terminal p and the fourth cascading connection terminal Z 22 is taken as terminal n, and the terminals p and n are arranged in a direction consistent with the terminals P and N of the converter bridge arm:
The neutral point of the bridge arm, i.e. terminal Ac, is led from the connection wire between the terminal n of the upper telescopic arm Bu and the terminal p of the lower telescopic arm Bd; and the inductor(s) Lb is(are) any of the following forms:
(1) There is one inductor Lb, which is located at any position of the series connection branch of the upper telescopic arm Bu and the lower telescopic arm Bd;
(2) There are two inductors Lb, which are respectively located at the two sides of the terminal Ac on the series connection branch of the upper telescopic arm Bu and the lower telescopic arm Bd; and
(3) There are a plurality of inductors Lb, which are respectively located in the various symmetrical units.
As another modified converter bridge arm, the telescopic arm is formed by cascading connection of the balance asymmetrical units; in two adjacent units, one of the fourth switch K 4 of the former unit and the first switch K 1 of the latter unit is replaced by a diode, and the diode has the same polarities as those of the reverse conducting diodes in the replaced switch.
As another modified converter bridge arm, the telescopic arm is formed by cascading connection of the balance symmetrical units; in two adjacent units, one or two of the seventh switch K 7 , the eighth switch K 8 of the former unit and the fifth switch K 5 , the sixth switch K 6 of the latter unit are replaced by diodes, and the two switches in the same unit cannot be replaced by diodes at the same time; the diode has the same polarities as those of the reverse conducting diodes in the replaced switches.
As another modified converter bridge arm, the telescopic arm is formed by cascading connection of the balance symmetrical units; in two adjacent units, one or two of the seventh switch K 7 , the eighth switch K 8 of the former unit and the fifth switch K 5 , the sixth switch K 6 of the latter unit are replaced by diodes, and the two switches in the same unit cannot be replaced by diodes at the same time; the diode has the same polarities as those of the reverse conducting diodes in the replaced switches.
Simultaneously, the wire connection mode of the fifth switch K 5 , the sixth switch K 6 , the seventh switch K 7 or the eighth switch K 8 replaced by the diodes is changed: the positive terminal of the fifth switch K 5 and the negative terminal of the sixth switch K 6 are connected to the second cascading connection terminal Z 12 , and the positive terminal of the seventh switch K 7 and the negative terminal of the eighth switch KB are connected to the fourth cascading connection terminal Z 22 ; this change in connection only falls upon the diodes for replacement, not upon the non-replaced switches; and the positive and negative terminals described herein refer to the polarities of the original switches before replacement, not the polarities of the diodes after replacement.
As another modified converter bridge arm, the telescopic arm is formed by cascading connection of the balance asymmetrical units; in two adjacent units, the third cascading connection terminal Z 21 of the former unit is directly connected with the first cascading connection terminal Z 11 of the latter unit, and the fourth cascading connection terminal Z 22 of the former unit is directly connected with the second cascading connection terminal Z 12 of the latter unit; and one of the fourth switch K 4 of the former unit and the first switch K 1 of the latter unit is omitted.
As another modified converter bridge arm, the telescopic arm is formed by cascading connection of the balance symmetrical units; in two adjacent units, the third cascading connection terminal Z 21 of the former unit is directly connected with the first cascading connection terminal Z 11 of the latter unit, and the fourth cascading connection terminal Z 22 of the former unit is directly connected with the second cascading connection terminal Z 12 of the latter unit; one of the seventh switch K 7 of the former unit and the fifth switch K 5 of the latter unit is omitted; and one of the eighth switch KB of the former unit and the sixth switch K 6 of the latter unit is omitted.
As another modified converter bridge arm, adopted between the terminal n unit of the upper telescopic arm Bu and the terminal p unit of the lower telescopic arm Bd is double-wire connection, which is specifically as follows: the fourth cascading connection terminal Z 22 of the terminal n unit is directly connected with the second cascading connection terminal Z 12 of the terminal p unit, and connection of the third cascading connection terminal Z 21 of the terminal n unit and the first cascading connection terminal Z 11 of the terminal p unit is implemented through an inductor Ls or a resistor R or through a parallel circuit of the inductor Ls and the resistor R.
As another modified converter bridge arm, the cascading connection mode of the plurality of units is replaced by the followings: a connection relationship of two groups of cascading connection terminals exists between two adjacent units, which is specifically as follows: the third cascading connection terminal Z 21 of the former unit is connected with the first cascading connection terminal Z 11 of the latter unit through an inductor Ls 1 , and the fourth cascading connection terminal Z 22 of the former unit is connected with the second cascading connection terminal Z 12 of the latter unit through an inductor Ls 2 ; any of the following four relationships exists between the inductor Ls 1 and the inductor Ls 2 :
(1) Ls 1 and Ls 2 are separate inductors;
(2) Ls 1 and Ls 2 are coupled inductors, and magnetic fluxes of voltage Uc balanced current on the energy storage capacitor C are mutually enhanced in the two inductors;
(3) Ls 1 and Ls 2 are separate inductors, and one of the two inductors is connected with the resistor R in parallel; and
(4) Ls 1 and Ls 2 are coupled inductors, magnetic fluxes of voltage Uc balanced current on the energy storage capacitor C are mutually enhanced in the two inductors, and one of the two inductors is connected with the resistor R in parallel.
As an application of the converter bridge arm, the present invention proposes that: the converter circuit has a conventional converter topology, and is characterized in that: the common bridge arm is replaced by the converter bridge arm, both the upper telescopic arm Bu and the lower telescopic arm 6 d of the converter bridge arm are formed by cascading connection of the balance asymmetrical units, thus any of several following converter circuits is formed:
(1) A bidirectional DC/DC converter is composed of the converter bridge arm, the terminals P and N of the converter bridge arm are connected with the positive and negative terminals of one direct current source, and the terminal An of the converter bridge arm is connected with a filter inductor in series and then connected with the positive and negative terminals of another direct current source;
(2) A single-phase or multiphase DC/AC or AC/DC converter is composed of one or a plurality of converter bridge arms, the terminals P and N of the converter bridge arms are connected in parallel respectively to serve as direct current positive and negative terminals, and the terminals Ac of the converter bridge arms are alternating current terminals for various phases, respectively:
(3) A single-phase or multiphase back-to-back AC/DC/AC converter is composed of two or a plurality of converter bridge arms, the terminals P and N of the converter bridge arms are connected in parallel respectively to serve as direct current positive and negative terminals, the terminals Ac of the first group of converter bridge arms are connected with the various phases of a first alternating current source respectively, and the terminals Ac of the second group of converter bridge arms are connected with the various phases of a second alternating current source respectively.
As an application of the converter bridge arm, the present invention proposes that: the converter is a three-phase or multiphase converter formed by further connection of one or a plurality of telescopic arms on the converter bridge arm; and the converter is characterized in that, the telescopic arms as well as the upper telescopic arm Bu and the lower telescopic arm Bd in the converter bridge arm are all formed by cascading connection of the balance symmetrical units; the connection mode of the converter is any of the following connection modes:
(1) The terminals P and N of the converter bridge arm are connected with the two phases of a three-phase power source respectively, one end of the new telescopic arm is connected with the terminal Ac of the converter bridge arm, while the other end is connected with the remaining phase of the three-phase power source, in this way, a star converter is formed; a star multiphase converter is formed by further increasing the number of the telescopic arms; or
(2) The terminals P and N of the converter bridge arm are connected with the new telescopic arm in parallel and connected with the two phases of the three-phase power source respectively, the terminal Ac of the converter bridge arm is connected with the remaining phase of the three-phase power source, in this way, a triangle converter is formed; and a polygon multiphase converter is formed by connecting a plurality of telescopic arms in series and then connecting these telescopic arms with the terminals P and N of the converter bridge arm in parallel.
As an application of the converter bridge arm, the present invention proposes that: the AC/AC converter has one or a plurality of converter bridge arms, and the circuit structure thereof is any of the following three structures:
(1) The terminals P and N of a single converter bridge atm are an alternating current port and the terminals Ac and N are another alternating current port, in this way, a single-phase AC/AC frequency converter is formed; or
(2) A multiphase alternating current port is led from the terminals P and N of the converter bridge arms in accordance a polygon or star connection method, and another multiphase alternating current port is led from the terminals Ac of the converter bridge arms, in this way, a multiphase AC/AC frequency converter is formed; or
(3) The terminals P and N of the first group of three converter bridge arms are connected with various input phases respectively in accordance with the triangle or star connection method, and the terminals P and N of the second group of three converter bridge arms are connected with various output phases respectively in accordance with the triangle or star connection method; the terminals Ac of the two groups of converter bridge arms are connected with primary and secondary windings of a three-phase medium-frequency transformer respectively, in this way, an electronic transformer is formed.
The present invention further proposes converter control method based on the foregoing converter bridge arm: terminal voltages Us of the units in the telescopic arms are controlled by regulating drive pulses of the switches, so as to control the terminal voltages Uu and Ud of the upper telescopic arm Bu and the lower telescopic arm Bd; an average current I PN passing between the terminals P and N of the converter bridge arm is controlled by dynamically regulating the sum of Uu and Ud, so as to control the average values of Uc of all the units in the converter bridge arm; regulation for potential at the terminal Ac is achieved by complementarily regulating Uu and Ud; distribution of the currents I P and I N of the upper telescopic arm Bu and the lower telescopic arm Bd is changed by dynamically regulating the relative magnitude of Uu and Ud, so as to balance the difference between the average values of Uc of the both; and the differences of Uc of the units in the telescopic arms are balanced by regulating the relative magnitude of the average values of voltage plateaus Us between the unit ports in the upper telescopic arm Bu and the lower telescopic arm Bd.
As an improved converter control method, one of the following four modes is adopted for the switch modulation pulse phase of the units:
(1) A control mode of identical pulse phase is adopt the units in the same telescopic arm; or
(2) A control mode of phase-shift is adopted for the units in the same telescopic arm; or
(3) SPWM modulation in which carriers are equally phase-shifted based upon angle of circumference is adopted for the units in the same telescopic arm, and carriers phases of the corresponding units between the upper telescopic arm Bu and the lower telescopic arm Bd are complemented; or
(4) For a three-phase DC/AC, AC/DC converter formed by three bridge arms, six units, which are located at the same positions of the bridge arms, are grouped and controlled under a SVPWM mode, and modulated carriers of the units in the same telescopic arm are equally phase-shifted based upon angle of circumference.
Advantageous Effects and Innovations of the Present Invention
The present invention solves the problem that the complexity of most of the high-voltage multilevel circuits rises sharply along with increase of the level number, and also solves the problem that non-transformer cascade multilevel circuits can only be used for reactive conversion, but not for active conversion, such as high-voltage motor variable frequency drive; compared with transformer cascade multilevel circuits, supply of a multi-winding independent power source from the transformer is not needed in the present invention; and meanwhile, the present invention also solves the problem that balance cascade multilevel circuits fail to adapt to high-voltage input/output conversion at the same time.
The present invention has the advantages that:
(1) As the level number of the converter increases, the number of components and devices required therein increases linearly, but no significant increase is found in the aspect of circuit complexity.
(2) The modular circuit structure has good electromagnetic compatibility between the interior of the modules and the modules.
(3) A plurality of high-voltage bidirectional conversion functions, such as AC/DC, DC/AC, AC-DC-AC, DC/AC, AC/AC and the like, can be realized, and active and reactive conversion can be executed.
(4) The system is imparted with a unit voltage self-balancing function, and there are quite moderate design conditions for safety redundancy, so good safety and reliability are achieved.
(5) Input/output energy exchange is directly associated with the units, weakening macro transfer of the energy among the modules at all levels and improving the efficiency.
(6) The present invention, integrated with high-voltage and high-frequency properties, can accomplish an extremely high equivalent operating frequency, reduce electro-magnetic interference (EMI) noise from equipment remarkably, and greatly reduce the dimension of filter.
(7) Startup of the high-voltage circuit is very easy and convenient, so a special high-voltage pre-charging circuit is not needed.
(8) Auxiliary power supply can be readily acquired from the units themselves, so a high-voltage isolation auxiliary power source is not needed.
With the outstanding characteristics above, the present invention is suitable for medium-voltage, high-voltage, and even ultrahigh-voltage AC/DC, DC/AC, DC/DC conversion, can be widely applied to medium/high-voltage frequency conversion, power electronic transformers, direct grid-connected power generation of new energies and smart grid applications, and is particularly suitable for ultrahigh-voltage conversion applications in a power system.
BRIEF DESCRIPTION OF THE DRAWINGS
FIG. 1 illustrates the structure of the multilevel bridge arm;
FIG. 2 illustrates the number and position of the inductors in the bridge arm;
FIG. 3 illustrates the balance asymmetrical converter units and the connection thereof;
FIG. 4 illustrates the balance symmetrical converter units and the connection thereof;
FIG. 5 illustrates the telescopic arm composed of the balance units;
FIG. 6 illustrates the simplified balance asymmetrical converter units and the connection thereof;
FIG. 7 illustrates the simplified balance symmetrical converter units and the connection thereof;
FIG. 8 illustrates the units located at the same positions of the telescopic arms;
FIG. 9 illustrates a variety of alternating/direct current circuits composed of the balance asymmetrical units;
FIG. 10 illustrates a three-phase electronic voltage regulator composed of the symmetrical units;
FIG. 11 illustrates an AC converter circuit composed of the balance symmetrical telescopic arms;
FIG. 12 illustrates an alternating/alternating variable frequency conversion circuit composed of the balance symmetrical units.
DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS
For a better convenience of reading, sequential numbers of the switches and the cascading connection terminals are omitted in description of the present invention hereinafter. However, their corresponding relationships could still be clearly and undoubtedly identified in accordance with the disclosure in this description and the accompanying drawings, and are kept highly consistent with the expression of the inventive content. Clarification is hereby made.
1.1 The Basic Principle of Telescopic Arms and Bridge Arm
The telescopic arms in the present invention are similar to common switches in the aspects of blocking voltage/current or direct conduction, e.g. the terminal voltages of the telescopic arm may be under a short-circuit or circuit-breaking state. Further, the telescopic arms have a voltage limiting feature, and when a telescopic arm is under a blocked state, blocking voltages exist at the two ends of the telescopic arm in case of forcible passage of currents. Voltage on the energy storage capacitor C is Uc. Voltage spike that is caused by stray parameters on the line can be naturally absorbed by C of the telescopic arm when the telescopic arm is blocked rapidly, suggesting that there is a quite excellent electromagnetic compatibility in the circuit.
The largest difference between telescopic arm and common switch is that voltages at the two ends of the telescopic arm are controllable through switch control, and may be the algebraic sum of Uc of a plurality of units; and if the switches of the various units are controlled under a PWM pulse mode, the average value of the terminal voltages of the telescopic arm may be regulated continuously.
The telescopic arm proposed in the present invention is formed by cascading connection of converter units. The so-called converter units include, for example, common topologies like BUCK, BOOST, BUCK-BOOST, half-bridge and full-bridge, as well as more complex topologies that are formed on this basis. Highlighted by the dotted boxes in FIG. 3 and FIG. 4 are all examples of the converter unit. The converter units form a single telescopic arm through cascading connection, e.g. the aforementioned fourth and fifth circuits (i.e. cascade multilevel and balance cascade multilevel) can be both considered as a telescopic arm. The procedure of the present invention that the telescopic arms composed of the units further form the bridge arm is shown in FIG. 1 .
The two terminals P and N of the bridge arm are capable of withstanding voltage U PN , the voltages that the telescopic arms Bu and Bd withstand are Uu and Ud respectively, and cascade voltage (Us, see FIG. 10 ) of the converter unit can be regulated through pulse control for the switches therein, thus voltage U AcN of the terminal Ac to the terminal N can be regulated. When asymmetrical converter units are adopted for the bridge arm, U PN , Uu and Ud are forward voltages; and when symmetrical converter units are adopted for the bridge arm, all these voltages are allowed to be negative, i.e. the bridge arm and the telescopic arms have positive and negative symmetrical polarities. The telescopic arms, bridge arm and switches in the present invention are assumed to be arrayed in an upper-positive and lower-negative way, and this is for good convenience in principle description; and if their array is changed to be in an upper-negative and lower-positive way, the same functions will be achieved as well.
To inhibit current impact and pulsation of the bridge arm during the regulation process, a series inductor Lb between Bu and Bd is indispensable, and this Lb may be disposed at any position on the series branch, or divided into two Lbs and then disposed at the two sides of Ac on the series branch respectively, and may also be divided into a plurality of inductors and then disposed in the converter units respectively. Differences in position and number of the series inductors only result in a tiny difference in circuit properties, but there is no essential difference in operating principle of the bridge arm itself, several examples are shown in FIG. 2 . For such applications as motor drive, each bridge arm can operate with a single Lb because of inductors in motor load, and in case of general loads, two Lbs are still needed to smooth the currents on the terminals of the bridge arm.
Positive and negative terminals (p*, n*) are led from the units at the outer side of the telescopic arm to serve as auxiliary terminals for the bridge arm, and there are four pairs of auxiliary terminals in total as the bridge arm has two telescopic arms. For easiness in description, the bridge arm and the telescopic arms in the drawings are no longer drawn up one by one. These auxiliary terminals are for standby purposes, for example, a low-voltage power source can pre-charge the telescopic arm Uc through these auxiliary terminals during startup. These auxiliary terminals are ineffective in the telescopic arms composed of the symmetrical units and in the bridge arm.
The bridge arm of the present invention may take the place of common switches in various bridge circuits or similar circuits to form new circuits.
1.2 The Principle of Energy Balance of Telescopic Arms
Telescopic arm is essentially a switch for energy storage, and currents will cause change of Uc of the units in a telescopic arm as long as the telescopic arm is not under a short-circuit state. Therefore, those telescopic arms are used for the passage of alternating currents or pulse currents; passage of steady direct currents is not allowed except under the short-circuit state. The value of C in the units is determined on the premise of no significant change of Uc (e.g. not beyond 1-10%), this is associated with current magnitude, and in the case of alternating currents, this is also associated with frequency. Uc of the units in the telescopic arm should be basically kept unchanged during applications.
The current and voltage on the telescopic arm involve direct and alternating currents or pulses. To realize the function of conversion, the following conditions need to be met 1) periodical energy balance of the telescopic arm is maintained; and 2) the bridge arm is capable of meeting the input/output voltage relationship.
Based on the principles of electric and electronic engineering, active current is not generated from the current on the telescopic arm and the output alternating voltage in output regulation for DC/AC. And to achieve energy balance, larger currents (I N , I p ) pass through the telescopic arm when there is a low voltage of the telescopic arm (i.e. shrinkage) and smaller reverse currents pass through the telescopic arm when there is a high voltage (i.e. stretching); what is related to this is the fact that the average current that passes through the telescopic arm will create a direct current and the value of this average current is multiplied by the input voltage of the bridge arm to obtain an input power of circuit.
In the case of AC/AC conversion and different input/output frequencies, alternating current voltage overlap components of these two frequencies are contained in the telescopic arm. A voltage and a current, which have different frequencies, will not generate active current according to the circuit theory, thus the requirement of maintaining periodical energy balance of the telescopic arm can be met as long as the active powers of the two frequencies, i.e. input/output frequencies, on the telescopic arm are zeroed respectively or mutually offset through regulation
In the case of AC/AC conversion and identical input/output frequency (which is equal to the situation that a converter acts as the voltage regulator), in order to meet the requirement of maintaining periodical energy balance of the telescopic arm, active power caused by currents on the telescopic arm is required to be zero. There should be a difference of 90° for the voltage phase on the telescopic arm if only active currents related to U PN pass through the bridge arm, as a result, AC/AC conversion will be accompanied by phase shift of input/output voltages.
In the case of DC/DC conversion, the bridge arm cannot output a steady DC voltage in order to avoid accumulation of the energy of the telescopic arm. However, the bridge arm can still output pulse voltages, and it is assumed that the output voltage is U AcNO a voltage higher than U AcNO is output during the earlier stage of one period, a voltage lower than U AcNO is output during the later stage, and the average value of this whole period is determined as U AcNO ; larger bridge arm currents (I N , I P ) pass through the bridge arm when U AcN is low and smaller reverse currents pass through the bridge arm when U AcN is high, in order to maintain periodical energy balance of the telescopic arm. Pulse-type DC/DC output can be changed into steady DC by means of filtering.
While filtering is still required in the foregoing AC/DC and AC/AC conversions, output ripples are typically pulsations at the magnitude of Uc and accordingly are easily filtered out. It is clear from the principle of DC/DC conversion of the bridge arm that, DC/AC conversion and AC/AC conversion may also operate under a pulse mode, and they will not necessarily be accompanied by phase shift of input/output voltages during use for an electronic voltage regulator. This pulse-mode operation has the shortcomings of large output pulse and the need of filtering enhancement.
Symbols Uu and Ud represent the terminal voltages of Bu and Bd respectively, and represents the voltage of the neutral point Ac to the terminal N in the bridge arm. I p , I N and I Ac respectively represent the currents that pass through the terminals N and Ac of the bridge arm, and I Ac =I p −I N ; and I PN represents the average current that passes through the bridge arm, I PN =(I p +I N )/2. Reference is made to FIG. 1 .
If the terminals P and N of the bridge arm are connected to the positive and negative terminals of a direct current power source, then Uu+Ud=U PN ; the telescopic arm has the characteristic that voltages at the two ends thereof are rapidly changeable, while voltages Uc of the energy storage capacitors in the units of the telescopic arm are relatively steady; change of the terminal voltages Us of the units leads to change of I p , I N and I Ac , the existence of series inductors places a limitation upon the change rate of current, and the change of current will finally affect Uu, Ud and U AcN .
Overall control for those parameters like I p , I N , I Ac , Uu, Ud and U AcN is accomplished via multi-management in the present invention:
(1) Control for I Pn is accomplished by regulating the sum of Uu and Ud, e.g. I PN will increase if Uu+Ud<U PN .
(2) During control for U AcN , a complementary relationship needs to be kept between the regulations for Uu and Ud, that is to say, increase of Uu is basically equivalent to decrease of Ud, and only in this way can disturbances on the average current I PN passing through the bridge arm be avoided.
(3) Ud=U AcN and Uu=U PN −U AcN during output balancing. Distribution of I p and I N can be changed by regulating the relative magnitude of Uu and Ud, so as to change the current I Ac at the terminal Ac. For example, if Ud increases and Uu decreases, then Ud>U AcN and Uu<U PN −U AcN . Accordingly, if I P decreases and I N increases, then I Ac decreases as well.
(4) The differences of Uc of the units can be balanced by regulating the relative magnitude of the terminal voltages (Us) of the units in the telescopic arm. In fact, for a bridge arm that is composed of asymmetrical units and balance symmetrical units, the differences of Uc of the units can be inhibited through the balancing function of this bridge arm; but excessive energy flow among the units can be reduced by regulating and balancing Uc of the units in a pulse way, in order to achieve the purpose of loss reduction.
In terms of energy, total energy of the bridge arm can be controlled only if I PN is controlled, which means the average value of Uc of all the converter units in the bridge arm is controlled; and the average values I P and I N of Uc Bu and Bd can be controlled respectively only if I P and I N are controlled.
For two of the above-mentioned control objects, only one can be selected. For example, only control for one of the control objects U AcN and I Ac can be realized, the former corresponds to the terminal Ac connected with an independent load (e.g. connected with a motor), and the latter corresponds to the terminal Ac connected with a voltage source (e.g. connected to a power grid). And this also applies to the relationships between Uu and Ud and between I P and I N , so detailed description is not needed herein.
In the bridge arm of FIG. 1 , there is only one connection wire between two telescopic arms and energy transfer between Bu and Bd is infeasible, which possibly results in too much change of Uc in Bu and Bd on the conditions of DC/DC, extremely low frequency, as well as the requirement on alternating frequency conversion under steady output. The change directions of Uc are opposite, so adoption of two-wire connection provides a channel for energy exchange between Bu and Bd, contributing to reduction of Uc change. And in this case, arrangement of the Lb inductors at the junction of Bu and Bd is inappropriate, and instead, they should be arranged at the terminals P and N to avoid disturbing energy exchange between Bu and Bd.
However, due to unequal currents Ip and I N , macro energy transfer between the two telescopic arms is likely to be quite prominent sometimes, thereby increasing the loss of the converter. In some telescopic arms with two-wire connection between the units, this kind of situation seems to be much less prominent due to equal currents among the units of the same telescopic arm. Corresponding balance switches (e.g. K 3 of each unit in FIG. 3 , K 5 and K 7 of each unit in FIG. 4 , etc.) in one unit can be shut off to reduce loss as long as those various units deviate from energy storage balance points in an acceptable way.
Another benefit brought by the aforementioned two-wire connection is that, pre-charging for the telescopic arm Uc can be accomplished as long as the low-voltage power source is connected with a pair of auxiliary terminals (e.g. p* and n* of the terminal n unit of Ed) of the bridge arm during startup of the bridge arm. Reference is made to FIG. 9 and FIG. 12 .
1.3 Symmetrical Converter Units and the Connection Thereof
A cascade circuit composed of symmetrical converter units as shown in the dotted box of FIG. 10 ) may be adopted as the telescopic arm of the present invention, the symmetrical converter units may be common full-bridge circuits and other conventional symmetrical converter units, and cascading connection between the units is achieved by a connection wire. Each symmetrical converter unit has three levels: −1, 0, and, 1, and two connection terminals Z 12 and Z 22 are completely symmetrical, and voltage plateau between unit terminals is Us (i. e. voltage between Z 12 and Z 22 ).
The telescopic arm of the present invention is the same as the fourth circuit above. When the converter units are all connected to an independent power source, the telescopic arm can be applied to DC/AC conversion or AC/DC conversion; and when there is no independent power source for the converter units, only alternating current reactive conversion (e.g. STATCOM and APF applications) can be realized by the telescopic arm because of lack of direct current access points.
However, if the fourth circuit, is used as the telescopic arm of the present invention, then the bridge arm composed of these telescopic arms and the series inductors Lb can be used for DC/AC or AC/DC high-voltage conversion except that there is no automatic balancing for Uc of the converter units, thus large difficulty in balance control becomes its weakness.
1.4 Balance Asymmetrical Converter Units and the Connection Thereof
The balance asymmetrical converter units (asymmetrical units for short) in the present invention and an example of the cascading connection thereof are shown in FIG. 3 . In FIG. 3 , Ls is disposed between Z 21 of the first unit (the unit on the left) and Z 11 of the second unit (the unit on the right), achieving the effect similar to that when disposed between Z 22 of the first unit (the unit on the left) and Z 12 of the second unit (the unit on the right), so detailed description is not needed herein. For convenience, FIG. 3 is herein regarded as the example to illustrate the principle.
Referring to FIG. 3 , during operation of the converter units, within each converter unit, switches K 1 and K 2 cannot be turned on simultaneously, and similarly, switches K 3 and K 4 cannot be turned on simultaneously either. To prevent short circuit resulted from simultaneous turn-on of the upper and lower switches, there is a dead zone gap for the turn-on action of K 1 or K 2 (and K 3 or K 4 ) of each unit with the time being slightly longer than the error time of switch control, and a pair of switches is not turned on within the dead zone time. Unit cascade voltage Us is the voltage between Z 12 and Z 22 within each unit that has two levels: 0 and 1. Us can be controlled by controlling the two switches K 1 and K 2 within each unit. For example: Us is Uc if K 1 is turned on and K 2 is turned off; and Us is 0 if K 1 is turned off and K 2 is turned on. The average value of Us of the converter units can be controlled by controlling the turn-on/off time ratio and phase of the switches within a switch period, so as to reach the effect of conversion regulation. A special state is reached if both K 1 and K 2 within a unit are turned off, and Us is indeterminate while there is no current passage; Us presents itself as Uc if a current passes through the reverse conducting diodes of K 1 .
A mode of vertically-mismatched connection between the adjacent units is adopted in the telescopic arm composed of the balance asymmetrical converter units, so levels that can be utilized by each unit are 0 and 1, and 1 level corresponds to 1 Uc. The telescopic arm formed by cascading connection of N converter units has N+1 levels, and in the bridge arm composed of such two telescopic arms, the controllable level number of U AcN is still N+1. For example, three controllable levels of the telescopic arm are 0, Uc and 2 Uc respectively after cascading connection of two balance asymmetrical converter units.
K 3 and K 4 of each unit play a role of balancing in the asymmetrical converter units. The difference of Uc of the adjacent units will accomplish automatic voltage sharing by means of charge transfer of adjacent relevant switches (i.e. relevant switches of the adjacent units) during cascading connection of the converter units. In FIG. 3 , K 3 and K 4 of the unit on the left and K 1 and K 2 of the unit on the right all belong to the adjacent relevant switches.
When switches K 2 of the unit on the right and K 3 of the unit on the left among these adjacent relevant switches are turned on. C of the two adjacent units are connected in parallel through the switches, so that two Ucs are converged, wherein Ls or R plays a role of restricting voltage-sharing current impact. When connected with Ls in parallel, R plays a role of inhibiting oscillation of the balance current between units. For example, this oscillation can be inhibited effectively if R 2 <Ls 1 /C, however, use of R will increase the loss to some extent. Power consumption will increase if Ls is independently replaced by R. For easiness in description, only one Ls connection condition is given in FIG. 3 . If the balance current is too large, it can also be restricted by controlling the turn-on time of K 2 and K 3 of each unit. The reverse conducting diodes of K 1 and K 4 of each unit offer a follow current channel when K 2 and K 3 of each unit are turned off. And if only the balance current passes through K 3 and K 4 of each unit, their power capacity requirements will be lower than those of K 1 and K 2 of each unit.
In the telescopic arm formed by cascading connection of the asymmetrical converter units, energy exchange can be achieved between the units through cascading connection terminals, to automatically balance the voltages Uc of the units.
K 3 and K 4 of the terminal n unit of the telescopic arm are unnecessary, but n′ that is led out therefrom can be used for Uc balancing between Bu and Bd. It can be readily thought of that, on the basis of use of K 3 and K 4 , a −Uc level can be added for the terminal n unit (and the telescopic arm) in such a manner that the terminal n′ takes the place of the terminal n to serve as the negative terminal of the telescopic arm, thus imparting the telescopic arm with a Uc reverse voltage blocking function; and detailed description is not needed hereinafter.
1.5 Balance Symmetrical Converter Units and the Connection Thereof
FIG. 4 illustrates an example of the balance symmetrical converter units of the present invention and the cascading connection thereof. In FIG. 4 , Ls is disposed between Z 21 of the first unit (the unit on the left) and Z 11 of the second unit (the unit of the right), achieving the effect similar to that when disposed between Z 22 of the first unit (the unit on the left) and Z 12 of the second unit (the unit on the right), so detailed description is not needed herein. For convenience, FIG. 4 is herein regarded as the example to illustrate the principle.
Referring to FIG. 4 , during operation of the converter units, within each converter unit, switches K 1 and K 2 cannot be turned on simultaneous, and similarity, switches K 3 and K 4 , K 5 and K 6 , and K 7 and k 8 cannot be turned on simultaneously either. To prevent short circuit resulted from simultaneous turn-on of the upper and lower switches, there is a dead zone gap for the turn-on action of K 1 and K 2 (and K 3 and K 4 , K 5 and K 6 , K 7 and K 8 ) with the time being slightly longer than the error time of switch control, and a pair of switches is not turned on within the dead zone time. Unit cascade voltage Us is the voltage between Z 12 and Z 22 within one unit that has three levels: 0, 1 and −1. Us can be controlled by controlling the four switches K 1 , K 2 , K 3 and K 4 within one unit. For example: in one unit, Us is Uc if K 1 and K 4 are turned on and K 2 and K 3 are turned off; Us is −Uc if K 1 and K 4 are turned off and K 2 and K 3 are turned on; and Us is 0 if K 1 and K 3 are turned on or K 2 and K 4 are turned on. The average value of Us of the converter units can be controlled by controlling the turn-on/off time ratio and phase of the switches within a switch period, so as to reach the effect of conversion regulation. A special state is reached if K 1 , K 2 , K 3 and K 4 in one unit are all turned off, and Us is indeterminate while there is no current passage; Us presents itself as Uc if a current passes through the reverse conducting diodes of K 1 and K 4 ; and Us presents itself as −Uc if a current passes through the reverse conducting diodes of K 2 and K 3 .
K 5 , K 6 , K 7 and K 8 of each unit are used for balancing in the symmetrical converter units, and the difference of Uc of the adjacent units will accomplish automatic voltage sharing by means of charge transfer of adjacent relevant switches during cascading connection of the converter units. In FIG. 4 , K 3 , K 4 , K 7 and K 8 of the unit on the left and K 1 , K 2 , K 3 and K 4 of the unit on the right all belong to the adjacent relevant switches.
If K 3 and K 7 or K 4 and K 8 of the unit on the left among the adjacent relevant switches are turned on simultaneously, there will be zero level between the connection terminals Z 21 and Z 22 of the unit on the left; there will be zero level between the connection terminals Z 11 and Z 12 of the unit on the right if K 1 and K 5 or K 2 and K 5 of the unit on the right are turned on simultaneously; there will be levels 1 and −1 between the connection terminals Z 21 and Z 22 of the unit on the left if K 3 and K 8 or K 4 and K 7 of the unit on the left are turned on simultaneously; and there will be levels 1 and −1 between the connection terminals Z 11 and Z 12 of the unit on the right if K 1 and K 6 or K 2 and K 5 of the unit on the right are turned on simultaneously. Balancing of Uc of the two adjacent units can be normally conducted and voltages can be converged only if the levels of the terminals at the two sides are controlled to be consistent, wherein Ls or R plays a role of restricting voltage-sharing current impact. When connected with Ls in parallel, R plays a role of inhibiting oscillation of the balance current between units. For example, this oscillation can be inhibited effectively if R 2 <Ls 1 /C. Power consumption will increase if Ls is independently replaced by R. For easiness in description, only one Ls connection condition is given in FIG. 4 . If the balance current is too large, it can also be restricted by controlling the turn-on time of K 5 , K 6 , K 7 and K 8 of each unit; the turn-on/off conditions of these switches are similar to those of the switches in the asymmetrical converter units, so detailed description is not needed herein. And if only the balance current of Ls passes through K 5 , K 6 , K 7 and K 8 of each unit, their power capacity requirements will be lower than those of K 1 , K 2 , K 3 and K 4 of each unit.
1.6 Simplification of the Balance Asymmetrical and Balance Symmetrical Converter Units, Connection Between the Units and Application Characteristics
FIG. 6 illustrates an example of the simplified balance asymmetrical converter units and the cascading connection thereof, and K 14 in everyone converter unit is simplified as diode; referring to FIG. 9 , a similar effect is reached in the case that K 11 in everyone converter unit is simplified as diode. FIG. 7 illustrates example of the simplified balance symmetrical converter units and the cascading connection thereof, and K 16 and K 18 in everyone converter unit are simplified as diodes. In the above simplified circuits, the control mode for balance current is different because circulation of the current of Ls cannot be maintained through those switches.
Shown in FIG. 12 is an example of the simplified balance symmetrical converter units with a change in connection of the diode terminals, as shown by diodes K 36 and K 38 in each unit. This change in connection does not affect the follow current function of Ls, but a shortened channel for the balance current could reduce some losses. The mode of direct connection of Z 21 and Z 11 between the adjacent balance asymmetrical units can save elements. The telescopic arm formed by such a connection, which is similar to the fifth circuit above, pertains to the present invention if used for formation of the bridge arm, but it has the defect of tack of a restriction mechanism upon the balance current; it has the advantage of facilitating integration of the telescopic arms into one module to further promote high-voltage small-power applications. The mode of direct connection of Z 21 and Z 11 between the adjacent symmetrical units reaches a similar effect, so detailed description is not needed herein.
For a telescopic arm that is formed by mixed cascading connection of the asymmetrical units and the balance symmetrical units, the units therein may also be simplified by reference to the foregoing mode, so detailed description is not needed herein.
Generally, the simplification above does not apply to the switches at the outer sides of the two ends of the telescopic arm.
When the units are connected through two inductors, Ls 1 and Ls 2 may have the same value. Use of these separate inductors brings the benefit that, the series inductors Lb can be scattered among the units, thus large inductors are not required in the converter. Reference shall be made to FIG. 12 for the example of connection of coupled inductors, the mode of dotted terminal connection of Ls 1 and Ls 2 results in mutual enhancement of the magnetic fluxes of Uc balance currents in the two inductors, thereby increasing the difference mode inductance between the units. Use of these coupled inductors brings the benefit that, magnetic fluxes resulted from macro currents (i.e. I P and I N ) between the units are mutually offset in the coupled inductors, as a result, the volume of connection inductors can be reduced.
When two connection inductors are adopted between the units, two connection wires are actually under an equivalent condition, switches for balancing are no longer assigned in the asymmetrical and balance symmetrical units, and all the switches participate equally in power transmission and Uc balancing, which is favorable for improving the conversion power of the units.
R is a damping resistor, which plays a role of inhibiting oscillation of the balance current between the units. For example, in the case of the separate inductors, such an oscillation can be inhibited effectively if R 2 <2Ls1/C.
1.7 Application Characteristics of the Balance Asymmetrical Converter Units and the Balance Symmetrical Converter Units
Both the balance asymmetrical converter unit and the balance symmetrical converter unit belong to balance converter units, and for the example of a telescopic arm composed of the balance converter units, reference shall be made to FIG. 5 . The advantages of both the balance converter unit and the symmetrical converter unit are combined in the balance symmetrical converter unit, which can realize not only balancing for Uc between the units, but also the symmetry between the cascading connection terminals at the both sides.
The telescopic arms composed of the symmetrical and balance symmetrical units further form a bridge arm, which is mainly applied to AC/AC conversion (including alternating current active and reactive conversions) and may also be applied to AC/DC conversion or DC/AC conversion. In the AC/AC conversion, for example, if Bu and Bd have an equal unit number m, then the level numbers of U PN of the telescopic arms and U AcN of the bridge arm are both 2*m+1. And in the AC/DC conversion or DC/AC conversion, if U PN <m*Uc, then the amplitude of U AcN may exceed that is to say, the alternating current voltage amplitude is larger than direct current voltage source!
The telescopic arms composed of the balance asymmetrical units further form a bridge arm, which can be applied to AC/DC conversion and DC/AC conversion. If n′ is used as the negative terminal of the telescopic arm, then for AC/DC/AC conversion, DC voltage amplitude can be utilized better because the voltage at the point Ac can be one level higher or lower than U PN .
The telescopic arms formed by mixed cascading connection of the balance asymmetrical units and the balance symmetrical units further form a bridge arm, which is relatively suitable for being applied under the aliasing condition of AC and DC voltages. For example, in a DC/AC converter circuit; the telescopic arms that are formed by mixed cascading connection can be used if AC output voltage is higher than DC input voltage.
1.8 Pulse Control Modes of the Converter Bridge Arm
There may be a variety of switch pulse control modes for the present invention on the premise that the requirement of balancing Uc of the converter units in the bridge arm is met. In fact, many pulse modulation schemes for common two-level inverter bridges can be used for controlling the converter bridge arm of the present invention, e.g. staircase waveform method (low order harmonic content minimization method, selective harmonic elimination method, etc.), pulse width modulation (PWM) (including harmonic elimination method, switch frequency optimization method, phase-shifted pulse width modulation method and space vector modulation method, and pulse amplitude modulation method). Sinusoidal pulse width modulation (SPWM), especially sinusoidal phase-shifted pulse width modulation method therein, is relatively suitable for pulse control in the present invention.
The corresponding switch actions of all the converter units may be synchronous (e.g. K 1 of all the units is synchronous), however, this will lead to a quite high voltage change rate at the point Ac so as to be unhelpful to electromagnetic compatibility, and moreover, a very large filter typically needs to be configured for the circuit. This approach has the advantage that the energy storage capacitors C of the units can still operate even if their values are quite small.
If previous and later actions of the corresponding switches of all the converter units differ slightly in order (e.g. by 1 microsecond), namely pulse phases between the adjacent units are delayed, then voltage can rise and drop by a ramp, contributing to reduction of the impact on power source and load.
Adoption of the control mode of identical pulse phase or phase delay in the units of the same telescopic arm equals replacement of high-voltage power semiconductor switches by the telescopic arms, and this brings much better reliability in voltage sharing control compared with direct series connection of low-withstanding-voltage power semiconductor switches.
If the corresponding switches of all the converter units are orderly out-of-phase by an equal angle according to the same switch period, the most smooth voltage waveform can be generated at the point Ac, the frequency of switch ripple is obtained by multiplying the switch frequency of the converter unit by the number of the converter units under cascading connection, and this method is known as sinusoidal phase-shifted pulse width modulation. For example, in the case of 19-level triangular wave carrier SPWM, every two carriers are staggered by 20°, and if the switch frequency of each converter unit is 10 kHz, the equivalent switch frequency of the telescopic arm can reach 180 kHz.
In the bridge arm, the corresponding switch actions of the two telescopic arms are complementary since the sum of voltages that the upper and lower telescopic arms withstand keeps unchanged (direct current voltages). Reasonable out-of-phase among the two telescopic arms and the multiphase bridge arm in the bridge arm is favorable for further inhibition of the switch ripple, in order to reduce the requirement of the converter on litter circuit remarkably.
In general, if the switches of all the converter units in the telescopic arm adopt synchronous actions, only a weak unbalanced dynamic of Uc will be aroused owing to inconsistent switch characteristics and other factors, and the problem is not severe even in the absence of Ls or R; however, a large unbalance dynamic of Uc will be aroused if delay, or even phase shift, is adopted, and this problem can be effectively solved by the balance mechanism in the present invention!
The three-phase converter circuit in the present invention can employ not only the aforementioned sinusoidal phase-shifted pulse width modulation, but also sinusoidal space vector pulse width modulation (SVPWM) and phase-shifted SVPWM methods that are used in conventional three-phase six-switch converters; and its applications in both DC/AC conversion and AC/DC conversion can improve the voltage utilization rate of the circuit.
An example of the specific approach is as below: each telescopic arm in the three-phase bridge arm is regarded as a conventional two-level switch, the conventional space vector modulation method is used for every unit in the bridge arm, all the converter units under cascading connection adopt the same switch period, the appositional units in the three bridge arms are orderly out-of-phase by an equal angle in each group, in this way, the most smooth sinusoidal voltage waveform can be generated among the three points Ac, and simultaneously, the advantage of high voltage utilization rate of the direct current source in the space vector modulation scheme can be put into full use as well. FIG. 8 illustrate an example about differentiation of the appositional units in the telescopic arm, three telescopic arms in FIG. 8 are three telescopic arms Bu of the three bridge arms in FIG. 9 respectively, and the converter units in the dotted box, every three of which are grouped, are considered as the appositional units; in addition, three other telescopic arms Bd of the three bridge arms further have three other corresponding appositional units; therefore, there are six appositional units in each group in total.
1.9 Various Converters Composed of the Converter Bridge Arms
The asymmetric bridge arm of the present invention can be used for bidirectional DC/DC conversion. The terminal An is one of the direct current terminals in DC/DC conversion application, and is an alternating current terminal in DC/AC application. During DC/DC application, a buck DC/DC converter is formed if terminals P and N are input terminals and Ac (after connection with a filter inductor in series) and N are output terminals; on the contrary, a boost DC/DC converter is formed if Ac (after connection with a filter inductor in series) and N are input terminals and terminals P and N are output terminals. The telescopic arms are unsuitable for maintaining steady direct currents (I P or I N ) and the energy exchange efficiency is quite low by means of two-wire connection between Bu and Bd, so pulse voltage is often output from U AcN in a DC/DC circuit, and series connection of the filter inductors at the terminals Ac is necessary.
During alternating current applications, AC voltage is formed between N (or P) and Ac by the bridge arm, and Ac serves as an AC terminal. The scheme of the present invention is applicable to three-phase conversion of DC/AC and AC/DC, but not limited to three-phase.
If one direct current power source is shared by three bridge arm direct current terminals, three-phase voltage can be formed at the terminals Ac of three bridge arms. One of the examples shown in FIG. 9 is a high-voltage rectification/inversion circuit. A, B and C are three-phase input points of a power grid, the power grid provides direct current for three-phase inverter bridges of the present invention through rectifiers, and three-phase high-voltage frequency conversion voltage is output from points a, b and c at the inverter side to achieve motor drive. Sinusoidal voltage is typically output from the high-voltage rectification/inversion circuit, and as a matter of fact, square wave voltage or trapezoidal wave voltage can be output in a similar way to drive such loads as brushless permanent magnetic motor.
Another example shown in FIG. 9 is a DC/AC converter circuit for photovoltaic grid-connected inversion, wherein grid-connected current is the control object of the terminal Ac.
A high-voltage frequency conversion circuit composed of two back-to-back three-phase inverter circuits is another example shown in FIG. 9 . The AC-DC-AC rectification/inversion converter circuit is generally known as back-to-back high-voltage frequency converter, a three-phase alternating current terminal is led from Ac of the first group of three bridge arms, a second three-phase alternating current terminal is led from Ac of the other group of three bridge arms, and this circuit may be used for non-transformer high-power-factor frequency conversion drive of a high-voltage motor and may also be applied to power transmission/distribution conversion in a power system.
In DC/AC and AC/DC conversion applications, the units in Bu and Bd are typically identical to each other in number to save the units; however, in DC/DC application, the number of units may differ based upon the ratio of input/output voltages.
For a multiphase star connection method, the terminals P of a plurality of bridge arms can be used as input terminals for various phases, the terminals Ac of the bridge arms can be used as output terminals for various phases, and the terminals N of a plurality of bridge arms are connected together to serve as common neutral points for input and output. For a multiphase polygon connection method, the terminals P and N a plurality of bridge arms can be connected in sequence and these connection points are used as input terminals for various phases, and the terminals Ac of the bridge arms are used as output terminals for various phases.
For three-phase, the star connection method is exactly the Y connection method, the polygon connection method is exactly the triangle connection method. FIG. 10 illustrates a three-phase electronic voltage regulator that adopts the Y connection method. A three-phase four-wire connection method can also be formed if neutral wires are led from three bridge arm common connection points in FIG. 10 . This circuit is a three-phase circuit in which energy can flow in a bidirectional way, and may have the function of electronic voltage regulation. Alternating current is fed in from the input terminals (A, B and C), and alternating current with the same frequency can be acquired at the output terminals (a, b and c). When the units in Bu and Bd are identical to each other in number, the voltage regulation function with a transformation ratio from 0 to 2 (theoretical value) can be obtained by controlling the switches (K 21 , K 22 , K 23 , and K 24 ) of the telescopic arms; this circuit may also be applied in an opposite way, with the transformation ratio approximately being 2 to 20. When the input/output ratios in application are close and SPWM control is employed, the number of units in Bu may be smaller than that in Bd to save the units; at this point, the current that passes through Bd is significantly lower than Bu, which is similar to auto-transformer.
The electronic voltage regulator has the functions of voltage regulation, phase modulation and asymmetry correction, is a device with a very flexible transformation ratio and the function of bidirectional voltage regulation, and can be used for power distribution voltage regulation for important loads like power system.
FIGS. 11 ( a ) and ( b ) respectively illustrate the examples of Y-shaped and triangular converters composed of the symmetrical telescopic arms, wherein the units in each of the telescopic arms may be identical in number. The telescopic arm composed of the symmetrical units can be used for forming a three-phase reactive converter, which is actually the fourth converter circuit mentioned above. The present invention can solve the problem of difficult voltage balancing in the energy storage capacitors of the units in the fourth circuit by adopting the telescopic arms formed by cascading connection of the balance symmetrical units, and should be well used in alternating current reactive applications. It can be easily understood that, further addition of the telescopic arms can form a multiphase star converter or a polygon reactive converter.
From the view of principle, those symmetrical units may also be used for AC/AC frequency conversion, but better reliability is only achieved by use of the balance symmetrical units because balance control in the frequency conversion circuit is complex. An AC/AC frequency converter adopting the Y connection method in FIG. 12 is similar to the circuit in FIG. 10 in the aspect of form, but a function of frequency conversion is added in this AC/AC frequency converter.
For an AC/AC frequency converter that adopts the single-phase and star connection method, given that input and output voltages on the same bridge arm could sometimes have approximate amplitudes but opposite directions, it is appropriate to enable the number of units in Bu to be twice the number of units in Bd on the premise that the input/output transformation ratio is approximately 1.
Further shown in FIG. 12 are electronic transformers that adopt the Y connection method and the triangle connection method. For the triangle connection method, it is appropriate that the ratio of the number of units Bu to the number of units in Bd is 1:1; and for the Y connection method, it is more appropriate that the ratio of the number of units in Bu to the number of units in Bd is 2:1. Use of the AC/AC topology definitely saves more units than the conventional back-to-back AC/DC/AC topology (the ratio is approximately 3:4).
In the electronic transformers of the present invention, both conventional sinusoidal/sinusoidal frequency converters and sinusoidal/square wave converters can be adopted in AC/AC, enabling medium-frequency transformers to operate under square waves to improve the conversion efficiency. The volume of the transformers is greatly reduced since the medium frequency adopted (e.g. 5 kHz) is much higher than power frequency (50 Hz).
1.10 Description and Embodiments
The symbols p′ and n′ in the drawings represent Z 11 and Z 21 of the asymmetrical and balance symmetrical units respectively, and they are present on the units (which are terminal p and n units respectively) at the outer side of the telescopic arm. The symbol m in the drawings represents the number of units of the telescopic arm, and m 1 and m 2 represent the number of units in Bu and the number of units in Bd, respectively.
As an extension of the present invention, one switch of the present invention is replaced by a special telescopic arm (herein referred to as micro telescopic arm) of the present invention, thereby forming the telescopic arm, the bridge arm and the converter system. The corresponding switches (e.g. all K 1 ) of the units in the micro telescopic arm adopt the control mode of identical pulse phase, so that the capacitance of the micro telescopic arm can be much smaller than that of the units in the telescopic arm, facilitating adoption of modular encapsulation. In fact, the micro telescopic arm can be used as a high-voltage switch and accordingly tends to construct a converter system with higher voltage class.
The aforementioned various inventive contents set forth in this application may be implemented in an independent or mixed way. FIG. 9 , FIG. 10 , FIG. 11 and FIG. 12 all illustrate the embodiments of the present invention. And two of these embodiments are detailed below.
(1) 11-level non-transformer high-voltage frequency converter Shown as the back-to-back high-voltage frequency converter in FIGS. 9 , A, B and C are input three-phase voltages, and a, b and c are output three-phase voltages. The circuit is of a back-to-back AC/DC/AC converter structure; the telescopic arm is composed of the balance asymmetrical converter units; the Ls-added double-wire connection described in 1.2 is adopted between the upper and lower telescopic arms: two groups of the three-phase bridge arms both operate under the SVPWM mode described in 1.8, the unit switch frequency is 10 kHz, and the telescopic arm has an equivalent switch frequency of 100 kHz. The number of units in each telescopic arm is 10 and the level number of the bridge arm is 11. The circuit is used for making up a three-phase high-voltage frequency conversion drive, and line voltage can reach 14.1 kV alternating current if each level is 2000V.
A low-voltage power source can be added between p* and n* of the terminal n unit of Bd (or between p* and n* of the terminal p unit of Bu) during startup; and the bridge arm can be directly switched to high voltage without a special high-voltage pre-charging line only if Bu and Bd are shrunk and the telescopic arms are stretched after c in the units is charged and electrified. In addition, if double-wire connection between Bu and Bd exists, this will be advantageous for simplifying startup control. It would be more advantageous for starting up a power source that Lb below Bd is moved to the terminal Ac of the bridge arm in FIG. 9 , and this Bd is composed of asymmetrical units, so n* of the terminal n unit of this Bd is the terminal N of the bridge arm, and for the bridge arm, only a terminal p* of the terminal n unit of this Bd needs to be led.
(1) 15-Level Electronic Voltage Regulator
As shown in FIG. 15 , three bridge arms correspond to three-phase voltage regulation, each bridge arm is composed of two telescopic arms Bu and Bd and two Lb, and the telescopic arm is composed of seven symmetrical converter units, in consideration of 7 zero levels that overlap, the telescopic arm has 15 levels because each converter unit has three levels. The circuit has a unit switch frequency of 5 kHz, phase-shifted SVPWM modulation is adopted between the units, and the telescopic arm has an equivalent switch frequency of 35 kHz. The line voltage of the voltage regulator can reach 39.6 kV alternating current if each level is 4000V.
(2) Photovoltaic Grid-Connected Inverter Circuit Formed by Mixed Cascading Connection of Asymmetrical Units and Symmetrical Units
It is worth mentioning that, in the high-voltage rectification/inversion circuit of FIG. 9 , mixed cascading connection of asymmetrical units and balance symmetrical units is adopted in the combined switch if DC input voltage is not high enough, thus the circuit is capable of realizing the booster conversion function well. It can be determined that the series voltage of the asymmetrical unit Uc is equal to DC voltage and the series voltage of the balance symmetrical unit Uc is slightly higher than the DC-exceeding amplitude part of AC. When output voltage exceeds DC voltage, the telescopic arms can withstand this reverse voltage. For example, mixed cascading connection of 10 asymmetrical units and 5 symmetrical units is adopted in the combined switch, the value of output voltage peak at the neutral point of the bridge arm, which can be used during grid-connected power generation, can reach 30 kV under 20 kV DC voltage if each level is 2000V.
INDUSTRIAL APPLICABILITY
The present invention is suitable for multilevel, medium-voltage, high-voltage, and even ultrahigh-voltage AC/DC, DC/AC, DC/DC conversion, can be widely applied to medium/high-voltage frequency conversion, power electronic transformer, direct new energy grid connection and smart grid applications, and is particularly suitable for ultrahigh-voltage conversion applications in a power system. | A converter bridge arm suitable for high-voltage applications and an application system thereof. The converter bridge arm comprises an energy storage capacitor (C) and a plurality of reverse-conducting switches, and is formed by serial connection of an upper telescopic arm (Bu), a lower telescopic arm (Bd) and an inductor (Lb). The upper telescopic arm (Bu) and the lower telescopic arm (Bd) are respectively formed by cascading connection of a plurality of units. The converter bridge arm has a simple modular structure, is easy to control, reliable and convenient for starting a high-voltage circuit, has self-balancing voltage sharing effect, and can operate without a transformer and has the characteristic of power bidirectional flow, does not require high-voltage isolation auxiliary power supply, has the advantages of suitability for high-frequency operation and electromagnetic compatibility, and can remarkably reduce the dimension of a filter. | 7 |
BACKGROUND OF THE INVENTION
This invention relates to a binding lace for use in binding a material to be bound, and more particularly to a cable harness by means of an automatic binder developed by the present inventors.
Hitherto, cable harnesses are widely used for electric connections, for instance in electric equipment, in automatic telephone switchboards, air planes, or automobiles. At the present times, these cable harnesses are manually prepared by using fine fibers or nylon laces. In other words, a lace is wound around a group of cables at least two turns, and then tightened fast to form a knot by pulling the opposite free ends of the lace. In this respect, such binding or tightening operation requires a force of over 5 to 10 kg, so that the hands of an operator are sometimes injured and in addition there results a large range of differences in the condition of the lace thus bound, with the accompanying shortcoming of poor operational efficiency. In order to avoid these shortcomings, there has been proposed a binding or tightening tool which tightens around a material to be bound a plastic band having tightening ring portions at its opposite ends. More particularly, the plastic band is wound around the material one turn, and then, the tightening ring portions, through which the ends of the band are passed, are tightened together by means of a tightening tool by a given tightening force. This type tool is a partial success in improving the operational efficiency and consistent quality of bound portions or knots, but the plastic bands are costly, so that in case binding portions are tremendously large in number, an increase in expense is no longer negligible and presents a critical economical problem, unlike the less expensive use of the prior art fine fiber, nylon lace and the like.
For binding a material to be bound with a binding lace for cable harnesses by an automatic binder, the binding lace should be at least required to meet the following criteria.
First, the binding lace should be capable of running stably along guide channels of a lace guide while it is sent into the lace guide by means of a feed-in mechanism.
Secondly, the binding lace should be capable of holding the condition in which it is guided along the guide channels to form a loop around the bound material.
Thirdly, the binding lace should be capable of being tightened with ease around the bound material and the loops formed therewith should be concentrated in a narrow range.
Fourthly, the binding lace should be capable of holding stably the opposite ends thereof between loop portions and provide a reliable binding.
However, since binding laces which are well known are circular in cross section and have smooth surfaces since they are produced by extrusion, the binding surfaces slip with respect to each other to decrease rapidly the tightening force in binding a bounded material.
Further, an elastic force which could change the diameter of a binding lace is not given to the binding lace, so that a looseness of a knot cannot be avoided. To avoid the above looseness after binding, binding laces which are provided with a rough surface are proposed. These binding laces however are not capable of elastic recovery when the tightening force is added to the binding laces to avoid looseness after binding.
On the other hand, a vinyl chloride lace has not given a strong tension and a nylon lace has given a strong tension, but has easily slipped and loosened.
SUMMARY OF INVENTION
The present invention provides a novel automatic binder for use in binding operations, particularly in binding cable harnesses. The automatic binder is capable of performing binding operations more efficiently than the prior art and at less cost.
The primary object of the present invention is to provide a novel binding lace which is provided with a novel property and structure having an excellent effect in binding a material, particularly a group of cables with the above automatic binder.
The other object of the present invention is to provide a novel binding lace which is capable of an accurate and rapid winding operation around a material, in case a material is bound with a binding lace by an automatic binder having a lace guide positioned around the material.
Another object of the present invention is to provide a novel binding lace which is capable of an easy and accurate tightened operation to stabilize a tightening condition.
Still another object of the present invention is to provide a novel binding lace best for use in case the lace is wound around a material at least two turns so that an each loop of the lace is overlapped and thereby a leading end and a trailing end of the lace are held fast to be tightened near the overlapping portion between at least one loop and the bound material.
A further object of the present invention is to provide a novel binding lace with which a binding operation is carried out with ease and the tightened condition is stabilized to meet the above objects.
Other objects of the present invention will be apparent from the following description, drawings and the claims.
BRIEF DESCRIPTION OF DRAWINGS
FIG. 1 is a front view of a binding lace which shows a preferred embodiment according to the present invention;
FIG. 2 is a cross sectional view of the binding lace;
FIG. 3 is a front view of a binding lace which shows another embodiment according to the present invention;
FIGS. 4 to 11 are cross sectional views of varied embodiments according to the present invention;
FIGS. 12 to 14 are perspective views of other embodiments according to the present invention;
FIG. 15 is a perspective view illustrative of a condition in which the binding lace is wound around a material to form loops;
FIG. 16 is a front view, partly in cross section of the entire construction of a novel automatic binder;
FIG. 17 is a developed front view illustrative of a lace guide by which a winding operation of an automatic binder is carried out;
FIG. 18 is a cross sectional view, partly broken away, of a feed-in, primary tightening roller mechanism by which a feeding operation and primary tightening operation are carried out in an automatic binder;
FIG. 19 is a view of an operating condition of a lace guide in case a binding lace runs along a lace guide;
FIG. 20 is a view of an operating condition of a lace guide in case a binding lace is wound around a bound material and then partially tightened;
FIG. 21 is a view of an operating condition of a lace guide when a binding lace is fully tightened;
FIG. 22 is a front view showing the condition in which a bound material is tightened with a binding lace.
DESCRIPTION OF THE PREFERRED EMBODIMENT
The preferred embodiments of the binding lace according to the present invention will be described in more detail. First, an embodiment of the automatic binder through which a binding lace is utilized will be described with reference to FIGS. 16 to 18 in advance of a description of a binding lace, so that the spirit of the present invention will be understood with ease. In FIG. 16, a ring-shaped lace guide 2 is attached to the tip portion of a body 1 of the binder of a gun type. The lace guide 2 consists of a stationary guide element 3 and a movable guide element 4 in case of the embodiment illustrated in FIG. 16. The stationary guide element 3 is secured, through the medium of an attaching pin inserted in an attaching hole 6, to a supporting portion 5 depending from the tip portion of the body 1. The rear portion of the body 1 is formed with a grip portion 7 projecting downwards. The tail portion of the grip portion 7 is formed with an air plug 8, through which a working medium, such as air is introduced. A trigger valve stem 9 of a trigger valve projects from the side of the supporting portion 5 of the grip portion 7, while a trigger 10 is provided in opposing relation to the trigger valve stem 9 on the side of the supporting portion.
Formed on the lowermost portion of the supporting portion 5 but adjacent to the stationary guide element 4 is a feed-in, primary roller mechanism 12 which is adapted to feed a binding lace 11 of the present invention into the stationary guide element 4 from a lace source such as a reel (not shown). Positioned on the supporting portion 5 and provided adjacent to the roller mechanism 12 is a cutter mechanism 15 for cutting a binding lace 11 at the initial and terminal ends thereof, and the mechanism 15 consists of a cutter drive cylinder 13 and two cutters 14.
Positioned on an upper portion of the grip portion 7 on the body 1 is a secondary tightening, pneumatic cylinder 16 in projecting relation towards the movable guide element 3, and the pneumatic cylinder 16 is adapted to effect the secondary tightening of the binding lace 11. Provided on the tip portion of the secondary tightening pneumatic cylinder 16 is a lace gripping mechanism adapted to grip a tip portion 11a of a binding lace.
The movable guide element 4 is integral with a guide casing 19 which is rotatably supported at a root portion 17 thereof by the body 1 by means of a pin 18.
The stationary guide element 3 and the movable guide element 4 are coupled to each other by means of a connecting arm (not shown) disposed between the attaching hole 6 of the stationary guide 4 and the movable guide element 3. When the trigger 10 is pulled a drive shaft of the movable guide element 4 which is positioned adjacent to a root portion mating surface 21 is first drawn towards the stationary guide element 3 then rotated towards the same until the tip end mating portion 22 of the movable guide element 4 mates with the tip end mating portion 23 of the stationary guide element 3. The opening operation of the lace guide 2 is carried out by a force of a spring which biases the movable guide element 4 and is not shown.
Guide channels 28 are defined over the entire inner peripheral surface 26 of the lace guide 2. The guide channels 28 are adapted to guide the binding lace 11, which serves as a binding material for the material 64 to be bound, such as wires, around the outer periphery of the material 64. This material 64 is inserted into a central hole 27 provided in the lace guide 2. The guide channels 28 in lace guide 2, as shown in FIG. 17, are composed of parallel channel portions 29 defined in the movable guide element 4, and intersecting curved channel portions 30 defined in the stationary guide eledment 3. A lace lead-in hole 32 extends through a thickness-increased portion 31 of the stationary guide element 3 and is continuous with a first intersecting channel element 33. The first intersecting channel element 33 is formed with a curved portion 25 which projects to the left and runs to the right lower portion of the stationary guide element 3 and then from an end opening 33a to an end opening 33b in the movable guide element 4. The intersecting channel element 33 is continuous by way of the end openings 33a, 33b with the first parallel channel element 34 in the movable guide element 4. The first parallel channel element 34 is continuous by way of an end opening 34b with an end opening 34a in the second intersecting channel element 35 in the stationary guide element 3. The second intersecting channel element 35 runs aslant towards the left lower portion of the stationary guide element 3 as shown in FIG. 17, and intersects with a third intersecting channel element 36, and then with the first intersecting channel element 33. The second element 35 is in a deeper position than the first and third intersecting channel elements 33 and 36 at their intersections 40 and 41, while being continuous by way of an end openings 35a, 35b, with a second parallel channel element 37 in the movable guide element 4. The second parallel channel element 37 is continuous by way of an end opening 37b and an end opening 37a positioned in the left upper portion of the stationary guide element 3 with the third intersecting guide element 36. The third intersecting channel element 36 intersects with the first intersecting channel element 33 at 38 in a deeper position than the first intersecting channel element 33, and then the second intersecting channel element 35 at 40 in a less deeper position than the second intersecting channel element 35, and then with the first intersecting channel element 33 at 72 in a less deeper position than the first intersecting channel element 33, and is continuous with the lace lead-out hole 39.
In this manner, the guide channels 28 are defined in the movable guide element 4 and the stationary guide element 3 in such a manner that the first intersecting channel element 33 and the third intersecting channel element 36 are shallow, as compared with the second intersecting channel element 35 and thus discontinued at the first intersection 40 and the second intersection 41 of the intersecting channel elements 33 and 36. Accordingly, the curvature of the second intersecting channel element 35 in the direction to lead a lace outside, which curvature is associated with the depth of the channel, is increased in a range covering the first intersection 40 and the second intersection 41.
A plurality of feed rollers 42 are provided within the first parallel channel 34 and the second parallel channel 37 in the guide channels 28 and defined in the movable guide element 4, with the axes of the rollers 42 running at a right angle to the lead-out direction of the binding lace 11. The outer peripheral surfaces of feed rollers 42 are smooth and round as usual rollers, although the outer peripheral surface may be provided with feed guide channels so that the binding lace may travel without moving laterally.
Another embodiment of the automatic binder according to the invention has no feed rollers, either in the parallel channel 29 or the intersecting channel 30. In this case, the binding lace 11 is advanced by means of a vibration of the movable guide element 3.
On the other hand, an automatic binder which is provided with many feed rollers 42 in both the parallel channel 29 and intersecting channel 30 is also contemplated by the invention.
A feed-in, primary tightening roller mechanism for feeding the binding lace into the stationary guide element 4 is shown in FIG. 18. A drive gear 45 is secured to the tip portion of a drive shaft 44 of a pneumatic motor 43, which is driven by compressed air. The pneumatic motor 43 permits rotation in the normal direction (in which the binding lace is fed into the stationary guide element 3, and so forth) as well as rotation in the reserse direction (in which the binding lace is tightened against the stationary guide element 4, and so forth.).
The drive gear 45 meshes through the medium of an intermediate deceleration pinion 46 with a first gear 47. The first gear 47 is integrally secured to a first roller shaft 48. A first roller 50 is secured through the medium of a one-way clutch 49 to the first roller shaft 48 in a manner to be free wheeling or fixed with respect to the first roller shaft 48. When the first roller 50 rotates in the normal direction, the first roller 50 is free wheeling, under the action of the one-way clutch 49, to rotate relative to the first roller shaft 48. In the reverse direction roller 50 is fixed with respect to shaft 48.
A guide channel 51 is defined in the outer peripheral surface of the first roller 50, thereby providing a space, through which a binding lace is to pass. The depth of the guide channel 51 is smaller in dimension than the diameter of the binding lace 11. A first-hold down roller 52 is positioned adjacent to the first roller 50. Between the first roller 50 and the first-hold down roler 52 there is mounted on the supporting portion 5 a lace lead-in pipe 53 by means of a pin 54 as shown in FIG. 16. The binding lace 11 is paid out from a reel not shown and via the lace lead-in pipe 53 inserted between the guide channel 51 and the first hold-down roller 52 in a manner that the binding lace 11 is somewhat squeezed together. The reel is positioned rotatably on a supporting plate 55 positioned between the grip portion 7 and the cutter mechanism 15. At this time, a resistance produced in the binding lace 11 against the aforesaid squeezing force caused a tension in the binding lace 11.
A second gear 56 is positioned in a manner to mesh with the first gear 47. The second gear 56 is secured to a second roller shaft 57, while a second roller 58 is also secured to the second roller shaft 57. A guide channel 59 is defined in an outer peripheral surface of the second roller 58, while a second hold-down roller 60 is positioned adjacent to the second roller 58. The depth of the guide channel 59 is the same as in the case of the guide channel 51.
A spacing between the first roller 50 and the second roller 58 is sufficiently large as compared with the diameter of the binding lace, so that the binding lace may pass between the first roller 50 and the second roller 58.
Positioned adjacent to the lace lead-out hole 39 of the stationary guide element 3 is a lace gripping means (not shown) and the tip portion of the binding lace 11 lead out from the lace lead-out hold 39 is gripped by the lace gripping means.
In order to feed the binding lace 11 into the stationary guide element 3 by means of the feed-in, primary tightening roller mechanism 12, the tip portion of the binding lace 11 is first led through the lace lead-in pipe 53, the guide channel 51 in the first roller 50 and the guide channel 59 in the second roller 58, then into the lace lead-in hole 32 beforehand, and then the pneumatic motor 43 is put into rotation in the normal direction. The rotation of the pg,16 motor 43 in the normal direction causes the drive gear 45, intermediate deceleration pinion 46, first gear 47 and second gear 56 to rotate in the normal direction, so that a torque is transmitted to the second roller 58 to feed the binding lace 11 along the guide channels 28 in the lace guide 2. The first roller shaft 48 under action of the one-way clutch 49 cooperates with the first hold-down roller 52 to impart a resistance produced when the binding lace 11 is compressed, to the second roller 58 as a load to cause a tension in the binding lace 11. As a result, the binding lace 11 is not allowed to stand still between the rollers 50 and 58, and thus is smoothly fed into the stationary guide element 3 so as to travel along the guide channels 28, then out of the lace lead-out hole 39 to be gripped by means of the lace gripping means.
When the binding lace 11 is threaded around the bound material 64 to form loops therearound and then tightened, the pneumatic motor 43 reverses its rotation. The reverse rotation of the pneumatic motor 43 causes the reverse rotation in the second roller 58, while the first roller 50 causes the reverse rotation along with the first roller shaft 48 under the action of the one-way clutch 49. As a result, the binding lace 11 is tightened fast by means of two rollers 50 and 58, and thereby the contact area of the binding lace 11 with the rollers 50 and 58 is increased to make the tightening force large. In addition, even in case there is a slip between the second roller 58 and the binding lace 11 during the first tightening operation due to simultaneous rotation of the first roller 50 and the second roller 58, the first roller 50 may well compensate for a decrease in the tightening force arising from the aforesaid slip.
A pneumatic circuit for driving and controlling the above members is built in the automatic binder.
FIGS. 1 and 2 show respectively a front view and a sectional view of the binding lace according to the present invention. The binding lace is formed in a double construction consisting of a core portion 62 and outer portion 63. The outer portion 63 is of high viscocity and elasticity as compared with the core portion 62, and may be prepared of vinyl chloride and the like.
On the other hand, the core portion 62 is of high rigidity and tensile strength as compared with the outer portion 63, and may be prepared of nylon and the like.
In view of the double-construction of the binding lace, the outer portion 63 is adapted easily to enlongate and contract as compared with the core portion 62 and yields a large contraction of the diameter of the outer portion 63 during the tightening operation and a sufficient recover of the large contraction of the diameter of the outer portion 63 after the cutting operation by means of the cutter 14. As a result, retaining of the tightened condition is remarkably improved. The binding lace 11 is rapidly fed along the guide channels 28 from the lace feed-in hole 32 into the lace feed-out hole 39 without buckling in case the binding lace 11 is pushed into the lace guide 2 by means of the feed-in, primary tightening roller mechanism 12 from only one side of the binding lace.
In addition, when the binding lace runs in the lace guide 2, the binding lace expands with elasticity outwardly in a radial direction of the lace guide 2 to keep the form of loops stable, and thereby the quantity of the binding lace 11 fed is always fixed by the feed-in, primary tightening roller mechanism 12.
When the binding lace 11 is tightened after the binding lace 11 feed is stopped, the diameters of the loops are gradually reduced so as to be wound around the material 64 to be bound, while the initial and terminal ends of the binding lace 11 are held between any one of the loops and the bound material 64. In this case, a strong tightening force which is imparted from the outside is sufficiently supported by a large tensile strength of the core portion 62, at this time the outside diameter of the binding lace 11 becomes gradually small due to an elongation of the binding lace 11.
On the other hand, the outside diameter of the binding lace 11 recovers due to the elasticity of the outer portion 63 after the external force is removed by cutting the initial and terminal ends of the binding lace 11 and then the outer portions 63 get twisted together so as to engage each other and each loop. Since the initial and terminal ends of the binding lace 11 are held fast between the loops and the bound object, the tightening force acting on the core portion 62 remains stable during a long time. In this manner, the large tensile strength in the core portion 62 and the engagement effect impart a multiplied stable tightening effect to the binding lace 11.
In the guide channels 28 in the lace guide 2, the binding lace 11 expands outwardly in a radial direction of the lace guide 2 due to the character of the core portion 62 and thereby the binding lace 11 is controlled by right and left surface and the outside surface thereof slidably to travel in the guide channels 28. Particularly at the cubic intersections 38, 40, 41 and 72, the binding lace 11 travels while contacting bottom portions of the intersections 33, 35 and 36 to form smoothly overlapping loops.
Next the movable guide element 4 is rotated toward the stationary guide element 3 to form the ring shape of the lace guide 2 as shown in FIG. 19. The lace guide 2 is thereby formed around the material 64, while the guide channels 28 open toward the internal wall of the lace guide, in other words, the material 64 in the lace guide 2. In this condition, when the pneumatic motor 43 is simultaneously rotated in the normal direction, the binding lace 11 which is beforehand settled in the form of semi-"S" is fed via the lace feed-in hole 32 into the lace guide 2, travels guided along the guide channels 28, until its tip portion 11a projects outside the lace guide 2 via the lace feed-out hole 39. The operational condition at this stage is shown in FIG. 19. In this condition in which the binding lace 11 is wound around the material 64, the gripping mechanism (not shown) grips tightly the tip portion 11a projecting from the lace feed-out hole 39, while the rollers 50 and 58 are stopped and reversed. The condition is illustrated in FIG. 20. Loop portions of the binding lace 11 which has been positioned in the guide channels 28 of the lace guide 2 are pulled outwardly in the opposing directions via the lace feed-in hole 32 and the lace feed-out hole 39. The diameters of the loop portions are gradually reduced and thereby the loop portions leave the guide channels 28 towards the central hole 27. The binding lace 11 is further tightened in opposite directions from the condition shown in FIG. 20 fast to be wound around the material 64 as shown in FIG. 21. The binding lace 11 somewhat changes the shape thereof to give a stable tightened condition because of the flexibility of the binding lace 11. After the binding lace 11 is bound tightly around the material 64 as shown in FIG. 21, the binding lace 11 is cut off by the cutter mechanism 15 in the projecting outward portion at a knot 24 and thereby the binding operation is completed. The lace guide 2 is then opened to permit the bound material 64 to be taken out.
In this manner, after the binding lace is fed according to the above process, a subsequent binding operation is possible. In this case, the stable binding operation without any trouble is allowed to be repeated with the binding lace according to the present invention.
In addition, the binding lace 11 is fed at a high rate so that the binding operation may be carried out efficiently by means of the automatic binder A.
On the other hand, even in the event of a low rate, the binding lace 11 is squeezed down by the first roller 50 and the first hold-down roller 52, the second roller 58 and the second hold-down roller 60 and fed into the lace feed-in hole 32 and then travels in the guide channels 28 sliding along both side walls and the bottom walls of the guide channels 28. Accordingly, static electricity is created on the binding lace 11 so as to charge the vicinity of the guide channels 28 and the binding lace 11, which is charged particularly at the feeding-in end with electricity.
Static electricity prevents the binding lace 11 from travelling and being freely fed into the lace feed-in hole 32. The above shortcoming is particularly disadvantageous in case the binding operation is repeated.
Under these circumstances an anti-static agent is coated at least on the outer surface of the binding lace 11, prepared from a plastic to form a membrane, or blended in the binding lace 11 during molding according to the other embodiments of the present invention so that easy travelling of the binding lace 11 is not prevented even due to sliding between the guide channels 28 and the binding lace 11. Thereby a lighter travelling may be given to the binding lace 11 even when a fresh binding lace 11 is always fed into the lace guide 2. In addition, it is necessary to build special anti-static mechanisms into the automatic binder A, so that the construction of the automatic binder 11 need not be complicated.
A binding lace 87 is shown in FIG. 13, which lace meets the above conditions and is circular in cross-section. The anti-static agent is coated on the outer surface of the outer portion 89. The anti-static agent may be blended in with the synthetic plastic matter forming the binding lace 87. In this case, coating of the surface of the outer portion 89 may be omitted. A binding lace 88 is shown in FIG. 14, an outer surface of which is coated or blended with an anti-static agent. The outer portion of the binding lace 88 is formed with many projecting ribs 88b. The anti-static agents may be listed as follows. There are anionic anti-static agents such as alkyl phosphate ester salts and sulfonated polystyrene triethanolamine salts, cationic electrification anti-static agents such as alkylamine derivatives, quaternary ammonium salts and dual ionic anti-static agents such as imidazoline metal salts and non-ionic anti-static agents such as polyoxyethylene aliphatic esters polyoxyethylene alkyl ethers.
FIG. 3 is a front view of another embodiment according to the present invention. The surface of an outer portion 70 is formed with many projecting ribs 73 along an a core portion 71. The many projecting lines 73 increase the elasticity of the outer portion 70 effectively to engage on each other in binding.
FIGS. 4 to 11 are cross-sectional views of binding laces formed with different projecting ribs. FIG. 4 shows a binding lace 66 which is formed with six sharp projecting ribs 74 distributed equally on the outer portion. FIG. 5 shows a binding lace 67 which is formed with six rectangular projecting ribs 75 spaced equally on the outer portion. FIG. 6 shows a binding lace 68 which is formed with six circular projecting ribs 76 distributed equally over outer portion. Of course, the number of projecting ribs must not be limitted to six.
FIG. 7 shows a binding lace 69 having a hexagonal cross-section with six edge portions 69a. The projecting ribs 73 to 76 and the tip portion 69a of the binding laces 65 to 69 which are constructed in the above manner are squeezed, engaged or laid upon one another to be contacted at intersections the loops when binding the material 64. Thereby, the elasticity of the binding laces 65 to 69 prevents loosening of knots or slipping out of the binding laces 65 to 69.
FIGS. 8 and 9 show other embodiments of binding laces 77 and 80.
The effect of the grooves 79 and 80a is the same as that of the projecting ribs 73 to 76 and the tip portion 69a of the binding laces 65 to 69.
FIG. 10 shows a binding lace 81 which is formed with a star-shaped cross-section.
FIG. 11 shows a binding lace 84 which is formed with projecting ribs 82 of a semi-circular cross-section and with a core portion 83.
FIG. 12 shows a binding lace 85 which is formed with an outer portion 86 spirally wound about a core of the binding lace 85. With the above outer portion 86 formed in the manner of a spiral, the force of friction is improved in binding.
The projecting ribs or grooves are continuously formed axially of the binding laces. These projecting ribs or grooves may also be formed intermittently axially of a binding lace.
Sectional shapes of the binding laces may be modified within the scope of the present invention to provide a balance between an outer tightening force and a holding force for maintaining the bound condition.
In addition, the core portion of the binding lace may be formed separate from the outer portion of the binding lace, so that the outer portion may somewhat slide with respect to the core portion.
Also, the core portion and the outer portion may be made of the same flexible material, such as a synthetic plastic material, which is provided with a sufficient tensile stress against the outer tightening force, because the elasticity of the outer portion may be affected by the physical form.
The outer portion of the binding lace shown in FIGS. 1, 3 and 4 to 12 may be coated with an anti-static preventing agent on the surface thereof, while the anti-static agent may be blended into the synthetic plastic which forms the binding lace. | A binding lace for a novel automatic binder developed by the present inventors is disclosed. The binding lace is continuously thrusted from only one side of the binding lace into a lace guide positioned around an object to be bound and then travels while sliding along the lace guide without buckling to form loops of several turns overlapping each other. During travelling, the binding lace is sent in the lace guide without standing still, due to the properties of an outer portion and a core portion of the binding lace, while the binding lace always expands elastically outwardly in radial direction of the lace guide due to the larger rigidity and tensile stress of the core portion to hold a looped configuration with the loops having substantially the same diameter as the lace guide. After travelling stops, the binding lace is capable of holding the same diameter of the loops and a tip portion of the binding lace is held in the neighborhood of the overlap of the loops. The binding lace is pulled back to wind around the material to be bound. It has sufficient friction and elasticity in the outer portion of the binding lace, so that the tip portion of the binding lace is held by the bound material and at least one loop of the lace. In addition, the binding lace exerts a large tightening force by the core portion thereof, sufficient for binding a bundle of electric wires and gives a stable binding condition for a long time due to the outer portion thereof. | 3 |
CROSS-REFERENCE TO RELATED APPLICATIONS
This is a continuation of U.S. patent application Ser. No. 12/413,733, filed Mar. 30, 2009, now U.S. Pat. No. 7,801,764, issued Sep. 21, 2010, which is a continuation of U.S. patent application Ser. No. 10/942,742, filed Sep. 16, 2004, now U.S. Pat. No. 7,512,547, issued Mar. 31, 2009, both of which are incorporated herein by reference in their entirety.
BACKGROUND OF THE INVENTION
Payments for goods and services with data cards, such as credit cards and debit cards, has become increasingly popular in recent years due in part to the ease and speed of performing data card transactions. For example, in retail settings, goods and/or services to be purchased are first entered into a cash register or point-of-sale terminal to determine their total cost. Once the total cost is determined, a consumer or a retail establishment associate swipes the consumer's data card to access consumer financial account information linked to the data card. The consumer provides approval, typically by providing a signature, thereby confirming intent to authorize payment from the consumer financial account for the goods. Following approval, funds are transferred from the consumer financial account to a financial account associated with the retail establishment. Although faster than traditional payment methods, such as payment by check, the time needed to swipe the data card and to approve the transaction contributes to the overall time each consumer spends in the checkout line waiting to purchase goods.
SUMMARY OF THE INVENTION
One aspect of the present invention relates to a method of sale. The method of sale includes processing a plurality of purchases to be sold to a consumer, identifying a consumer financial account held by a financial institution, receiving authorization from the financial institution to enable payment for the plurality of purchases from the consumer financial account, and providing the consumer with an option to approve the payment from the consumer financial account. The option is provided during processing of the plurality of purchases. Other features and advantages are also disclosed.
BRIEF DESCRIPTION OF THE DRAWINGS
Embodiments of the invention will be described with respect to the figures, in which like reference numerals denote like elements, and in which:
FIG. 1 is a perspective view illustrating one embodiment of a transaction approval system, according to the present invention.
FIG. 2 is a flow chart illustrating one embodiment of a method of sale, according to the present invention.
FIG. 3 is a top view illustrating a portion of the transaction approval system of FIG. 1 during the method of sale of FIG. 2 .
FIG. 4 is a top view illustrating a portion of the transaction approval system of FIG. 1 during the method of sale of FIG. 2 .
FIG. 5 is a top view illustrating a portion of the transaction approval system of FIG. 1 during the method of sale of FIG. 2 .
FIG. 6 is a top view illustrating a portion of the transaction approval system of FIG. 1 during the method of sale of FIG. 2 .
DETAILED DESCRIPTION
A process and system for approving and confirming financial card transactions, according to embodiments of the present invention, decrease overall consumer time spent in checkout lines. Decreasing the overall time each consumer spends in the checkout line provides a more attractive shopping environment and experience, increases overall efficiency of the retail establishment, decreases the labor necessary to handle consumer purchases, and improves the bottom line of the retail establishment or other entity from which goods and services are purchased.
FIG. 1 illustrates one embodiment of a transaction approval system 10 including a cash register or point-of-sale terminal 12 , a financial transaction terminal 14 , and a stylus 16 . In one embodiment, point-of-sale terminal 12 is electrically coupled with financial transaction terminal 14 via a cord 18 or wireless connection, and stylus 16 is coupled with financial transaction terminal 14 via a cord 20 . Alternatively, stylus 16 is not mechanically coupled with financial transaction terminal 14 . Purchases by a consumer are processed or entered into point-of-sale terminal 12 to arrive at a total cost to be charged to the consumer for the entered purchases. Purchases include goods and/or services being sold to the consumer.
Financial transaction terminal 14 is configured to receive a financial transaction card 22 to access a related consumer financial account or source of funding and to charge the total cost of the purchases to the financial account by way of financial transaction card 22 . Financial transaction card 22 is one of a credit card, a debit card, or a stored-value card such as a gift card, to name several examples. Stylus 16 allows a user to enter a user signature and/or other confirmation indicator into financial transaction terminal 14 , to approve or confirm the transfer of funds from the financial account to complete the purchase and ultimately perform the associated financial transaction or withdrawal.
Point-of-sale terminal 12 includes a keyboard 30 , a scanner 32 , a monitor 34 , and a printer 36 . Item barcodes or other product information can be entered into point-of-sale terminal 12 via keyboard 30 or scanner 32 , which, in one embodiment, is capable of reading UPC or bar codes off of the purchases. Alternatively, point-of-sale terminal 12 includes a radio frequency identification (RFID) device capable of reading and/or registering cost data and other purchase data. The information entered into point-of-sale terminal 12 can be viewed by a worker or associate of the retail establishment and/or a consumer via monitor 34 . Finally, upon completion of the financial transaction or upon each addition of a new purchase or item to the point-of-sale terminal 12 , printer 36 prints transaction details to a receipt 38 including a list of the purchases processed as well as the cash or amounts charged to the consumer's financial account to pay for the registered purchases. In one embodiment, receipt 38 includes a printout of a digitally captured signature, as will be further described below.
Financial transaction terminal 14 is a financial transaction card reader in communication with at least one financial institution network. As such, in one embodiment, financial transaction terminal 14 includes a financial transaction card reception slot 40 for at least partially receiving financial transaction card 22 . In particular, financial transaction card 22 includes a magnetic strip 24 along one side of financial transaction card 22 including a magnetic representation of the information necessary to access the consumer financial account linked to or associated with financial transaction card 22 . Accordingly, reception slot 40 extends along a side of financial transaction terminal 14 and includes a reading mechanism capable of accessing magnetic strip 24 to obtain necessary information from financial transaction card 22 . Financial transaction terminal 14 is configured to selectively receive financial transaction card 22 as financial transaction card 22 is slid from a first end 42 of reception slot 40 to a second end 44 of reception slot 40 . As financial transaction card 22 is slid from first end 42 to second end 44 of reception slot 40 , the information on magnetic strip 24 is read by financial transaction terminal 14 and the associated financial account is electronically accessed based upon the information from the magnetic strip 24 .
Alternatively, in one embodiment, financial transaction terminal 14 includes an alternative financial transaction card reception slot 46 instead of financial transaction card reception slot 40 . Financial transaction card reception slot 46 is positioned at one end of financial transaction terminal 14 and is configured to receive financial transaction card 22 and to pull financial transaction card 22 fully within financial transaction terminal 14 for reading information from magnetic strip 24 of financial transaction card 22 to access the associated financial account.
Financial transaction terminal 14 additionally includes a user interface, monitor, or touch screen 48 on a top surface 45 of financial transaction terminal 14 . Touch screen 48 is configured to relay information to the consumer or to the worker or associate of the retail establishment utilizing financial transaction terminal 14 . In one embodiment, touch screen 48 also is configured to be contacted by stylus 16 to enter information into financial transaction terminal 14 . In particular, financial transaction terminal 14 may exhibit buttons such as button 62 in FIG. 3 on touch screen 48 that can be pressed or otherwise selected with stylus 16 . In one embodiment, stylus 16 is an elongated, pencil-like member including a pointed end configured to contact touch screen 48 . In addition, touch screen 48 may display boxes for receiving written information or signatures. Touch screen 48 is capable of presenting different touch buttons and messages to a user throughout the transaction approval process.
One embodiment of a method of sale 50 is generally illustrated with reference to FIG. 2 . At 52 , the purchases to be sold to the consumer begin to be processed. In particular, in one embodiment, at 52 , the product codes of the purchases are entered into point-of-sale terminal 12 by the worker of the retail establishment or the consumer via scanner 32 , manually via keyboard 30 , RFID device, or other entry device or system.
While purchases are being processed for sale at 52 , touch screen 48 displays a message giving the consumer an option to initiate the financial transaction. In one embodiment, the message notifying the consumer that they may initiate the transaction is a message such as “PLEASE INSERT CARD” as illustrated in FIG. 1 . If, at 54 , the consumer decides to initiate the transaction, the consumer slides financial transaction card 22 through reception slot 40 or inserts financial transaction card 22 into reception slot 46 of financial transaction terminal 14 at 56 . In one embodiment, only one financial transaction card reception slot 40 or 46 exists and, therefore, financial transaction card 22 must be inserted into or slide through the financial transaction card reception slot 40 or 46 existing in the particular financial transaction terminal 14 of transaction approval system 10 .
Once the financial transaction card 22 is inserted, financial transaction terminal 14 interfaces with magnetic strip 24 to read information from magnetic strip 24 . More specifically, financial transaction terminal 14 reads the information from magnetic strip 24 to remotely identify the financial institution or a financial network associated with the consumer financial account linked to financial transaction card 22 . In one embodiment, transaction approval system 10 uses the information to determine the type of financial transaction card 22 that has been inserted, more specifically, whether the financial transaction card 22 is a debit card, a credit card, stored-value card, etc. Alternatively, upon insertion of financial transaction card 22 , in one embodiment, transaction approval system 10 prompts the consumer to identify the type of financial transaction card 22 that has been inserted.
Accordingly, following insertion of financial transaction card 22 into financial transaction terminal 14 , at 58 the consumer decides whether he or she wishes to begin the transaction approval process. In particular, at 58 , touch screen 48 presents the consumer with confirmation approval page or graphical interface 59 indicating that upon approval by the consumer, the consumer agrees to pay for all charges incurred in accordance with the cardholder agreement with the financial institution holding the financial account linked to financial transaction card 22 , as illustrated in FIG. 3 . In one embodiment, graphical interface 59 on touch screen 48 includes a signature block 60 , for receiving a consumer signature, and/or a transaction confirmation button 62 .
In one embodiment, graphical user interface 59 additionally includes a charge box 64 for indicating whether the total charges or cost of purchases have been determined and, if so, what the total charges are. At 58 , charge box 64 is empty, indicating that the total charges for the purchases have not yet been determined (i.e. purchases are still being processed and a final, total charge has not yet been determined). In one embodiment, the empty charge box 64 is yellow or another bright color to draw consumer attention to the fact that the total charges are not yet determined. In one embodiment, once the total charges are computed, the color of charge box 64 is changed or removed. Alternatively, in one embodiment, charge box 64 remains a consistent color when empty and when displaying the total cost. Graphical interface 59 displayed by financial transaction terminal 14 as illustrated in FIG. 3 allows the consumer to determine whether or not they wish to continue approving the transaction at 58 .
More specifically, the objects displayed on touch screen 48 at this point allow the consumer to decide whether or not to provide a consumer signature within signature block 60 immediately or to wait until a subsequent time in the method of sale 50 . In particular, if the consumer chooses to continue approving the transaction, then at 70 the consumer provides and transaction approval system 10 receives a signature 72 within signature block 60 as illustrated with reference to FIG. 4 . If the consumer chooses not to continue approving the transaction at this time, the method 50 continues to 78 where processing of the purchases is completed, as will be further described below. Once signature 72 of the consumer is provided, the consumer determines whether or not they wish to finalize approval of the transaction at 74 .
If the consumer decides to continue the transaction approval process, then at 76 the consumer provides and the transaction approval system 10 receives final transaction approval or confirmation. If the consumer decides not to continue the transaction approval process, method 50 continues to 78 to complete processing of the purchases, as will be further described below. In one embodiment, the consumer provides final transaction approval by contacting confirmation button 62 of graphical user interface 59 with stylus 16 . Contacting confirmation button 62 also signifies to financial transaction terminal 14 that the consumer has finished providing signature 72 . At 78 , following receipt of the final transaction approval, processing of the purchases is completed and the total cost of the processed goods is displayed in charge box 64 as illustrated in FIG. 5 . In one embodiment, display box 64 , once colored to indicate that total charges had not yet been determined, optionally changes or removes the color once the cost is displayed in box 64 . In other embodiments, box 64 remains yellow or otherwise highlighted.
Following calculation of the total cost of purchases, the financial transaction terminal 14 uses the information from magnetic strip 24 of financial transaction card 22 to access the financial institution or network associated with the inserted financial transaction card 22 at 79 . The financial institution or network provides the financial transaction terminal 14 with an indication of whether the financial account is sufficiently funded or authorized to support the current transaction. In particular, the financial institution or network provides an authorization to use the financial account or an indication that use of the financial account is declined. If the financial institution or network authorizes the current transaction the method of sale 50 continues.
At 80 , data terminal 14 determines whether transaction approval is complete. If transaction approval is determined to be complete, then at 82 the transaction is completed by transferring funds, or at least an electronic representation of funds, or by authorizing such a transfer, from the consumer financial account linked to financial transaction card 22 to a financial account associated with the retail establishment. Upon conclusion of the financial transaction printed receipt 38 is created or finished and provided to the consumer detailing the purchases and the financial transaction. In one embodiment, printed receipt 38 includes a printed form of signature 72 digitally provided to financial transaction terminal 14 . Upon completion of the financial transaction, the consumer is free to take the purchases from the retail establishment to their car or other desired location outside of or away from the retail setting.
If, at 54 , the consumer decided not to begin the authorization process 50 or if at 58 or 74 the consumer decided not to continue the transaction approval process, the method of sale 50 continues directly to step 78 in which, as described above, processing of the purchases is completed and the total cost of the processed purchases is provided to the consumer, for example, by display of the cost within cost display box 64 as illustrated in FIG. 6 . At 80 , transaction approval system 10 determines if transaction approval is complete.
If, at 80 , transaction approval system 10 determines that the transaction authorization is not complete (as it will if the consumer chose not to begin or finish the transaction or approval process at 54 , 58 , or 74 ), the method of sale 50 continues to 84 . At 84 , transaction approval system 10 determines whether financial transaction card 22 has or has not yet been inserted into financial transaction terminal 14 to initiate the transaction. If financial transaction card 22 has not yet been inserted into financial transaction terminal 14 , transaction approval system 10 will continue to prompt the consumer to enter financial transaction card 22 into financial transaction terminal 14 via touch screen 48 . At 86 , a consumer eventually inserts financial transaction card 22 into financial transaction terminal 14 .
As described above, upon insertion of financial transaction card 22 , financial transaction terminal 14 interfaces with magnetic strip 24 to read the information from magnetic strip 24 to remotely identify the financial institution or at least a financial network associated with the financial account linked to financial transaction card 22 . In one embodiment, transaction approval system 10 uses the information to determine the type of financial transaction card 22 that has been inserted, and more specifically, whether the financial transaction card 22 is a debit card, a credit card, a stored-value card, etc. Alternatively, upon insertion of financial transaction card 22 , in one embodiment, transaction approval system 10 prompts the consumer to identify the type of financial transaction card 22 that has been inserted.
At 88 , following insertion of financial transaction card 22 into card terminal 14 , the consumer is prompted to provide consumer signature 72 via graphical interface 59 in a similar manner as described above with respect to receiving consumer signature 72 at 70 . Following 88 , in one embodiment, the consumer is presented with graphical interface 59 on touch screen 48 , such as that illustrated in FIG. 5 . At 90 , the consumer provides and transaction approval system 10 receives final transaction approval, and the consumer acknowledges consumer signature 72 is complete by contacting touch screen 48 , more particularly, by interaction with final approval button 62 via stylus 16 . At 82 , the funds are transferred or authorized to be transferred and receipt 38 is printed to complete the transaction. Once the transaction is complete, the consumer is free to leave the retail establishment with the purchases and receipt 38 in hand.
Alternatively, if at 84 it is determined that financial transaction card 22 has already been inserted into financial transaction terminal 14 , transaction approval system 10 determines, at 92 , whether consumer signature 72 has yet been received. If the consumer signature has not yet been provided, the method of sale 50 continues to 88 where consumer signature 72 is provided in signature box 60 . Continuing once again to 90 , final transaction approval is provided for receipt by transaction approval system 10 via consumer contact with approval button 62 via stylus 16 , and the transaction is completed at 82 as described above.
If, at 92 , transaction approval system 10 determines that a consumer signature 72 has already been received, the method of sale 50 continues directly to 90 where final transaction approval is provided by the consumer as described above. Once again, following final transaction approval, the transaction is completed at 82 , and a consumer is provided with receipt 38 , thereby leaving the consumer free to leave the retail establishment with the purchases and receipt 38 in hand.
A transaction approval system and method of sale, according to embodiments of the present invention, allow the consumer to decide when to start and finish consumer approval of a financial transaction. In particular, in order to speed the transaction process, a consumer can provide a signature and final transaction approval prior to the final processing of all the purchases. However, in other instances, a consumer may provide a signature while the purchases are being processed, but wait to provide final transaction approval until the total charges have been determined. In yet another instance, a consumer may wait until the total charge for the purchases is determined before providing a signature and a final transaction approval.
Although the invention has been described with respect to particular embodiments, such embodiments are for illustrative purposes only and should not be considered to limit the invention. Various alternatives and changes will be apparent to those of ordinary skill in the art. For example, other display screens or buttons may be presented to a consumer in order to provide the consumer with a two or three point transaction approval process that can be entered into at a time chosen by the consumer. In addition, one or more retail employees can prompt the consumer to complete one or more tasks in the process. Additional modifications and changes will be apparent to those of ordinary skill in the art. | A method of sale including processing a plurality of purchases to be sold to a consumer, identifying a consumer financial account held by a financial institution, receiving authorization from the financial institution to enable payment for the plurality of purchases from the consumer financial account, and providing the consumer with an option to approve the payment from the consumer financial account. The option is provided during processing of the plurality of purchases. Transaction approval systems provide additional advantages. | 6 |
BACKGROUND OF THE INVENTION
The present invention relates to paper machines.
In particular, the present invention relates to structure for damping pressure and flow rate disturbances in pulp suspension flowing toward a headbox.
Thus, the structure of the present invention is intended to be mounted in the pulp pipe system which delivers the pulp suspension to the headbox of the paper machine.
As is well known, disturbances will unavoidably occur in the pulp suspension flowing in an approach pipe system of a paper machine. Thus the pulp stock flows through this approach pipe system toward a headbox such as a hydraulic headbox. With respect to such disturbances, the situation is ideal in the event that each longitudinal element at the lip slice of the headbox continuously discharges precisely the same quantity of suspension per unit of time at a constant velocity. In the event that the rate of flow is the same over the entire breadth of the slice, but varies with respect to time, then there will be a dry weight variation in the machine direction in the paper manufactured thereby.
On the other hand, if the pulp suspension flow is constant with respect to time but varies depending upon the particular location in the cross-machine direction, then a transverse dry weight variation will occur in the paper. This latter type of variation cannot be eliminated by way of the present invention nor by any other damping systems located in the approach pipe system of the stock supply. It is well known that the adjustment of the profile in the cross-machine direction, which is the problem in this particular case, is carried out by way of fine adjustment spindles at the lip slice of the headbox.
Briefly, the output disturbance signals with which the present invention is concerned are in the form of dynamic pressure variations at the lip flow aperture, while input disturbance signals are derived from a number of different sources such as variation in hydrostatic pressure in the pipe system, variation in the output pressure of the pump, variation in the pressure drop of the flowing suspension, pulse pressures due to vibrations transmitted to the pipe system through its supports, and pressure variations caused by turbulence vortices in the pipe system, particularly at the location of valves, pipe bends, etc. It has been found in practice that the different disturbance signals each have their own specific, frequently rather wide frequency spectrum. However, the disturbance signals from pumps, for example, have spectra characterized by distinctly absorbable peaks at the frequencies which are consistent with the speed of rotation of the respective pump and with its multiplesand subharmonics.
In general, paper machine headboxes may be divided into three main groups:
(a) headboxes provided with an air cushion forming a part of the headbox, or so-called air cushion headboxes,
(b) hydraulic headboxes provided with an air cushion and mounted separately from the headbox itself, wherein air tanks are located either in the approach pipe system for the paper stock suspension in advance of the distribution header or subsequent to the distribution header, and
(c) hydraulic headboxes which do not have any air cushions.
The air cushions are normally used in connection with headboxes in an attempt to equalize pressure variations occurring in the pulp suspension flow prior to the discharge aperture or lip slice of the headbox. These variations may originate in the pulp stock system preceding the headbox or in the headbox itself.
In an air cushion headbox according to type a) referred to above, there is usually an efficient damping of pressure variations with respect to time, inasmuch as the surface area of the pulp stock contacting the air cushion is relatively large while the height of the pulp stock, measured perpendicularly to its direction of flow, is relatively small. A further advantage of such headboxes resides in the fact that the air cushion usually extends up to the vicinity of the discharge slice, so that there is little opportunity for new pressure variations to be generated in the flow between the air cushion and the lip slice.
However, even though the above type of construction has the above favorable features, these air cushion headboxes have in recent times yielded, particularly in the most modern fast paper machines, to hydraulic or fully hydraulic headboxes of the types (b) and (c) referred to above. This development has occurred because the latter two types of headboxes are easier to utilize and situate in connection with the relatively new twinwire formers, and in addition such structures have lower manufacturing costs. The greater turbulence of the pulp stock jet discharging from the lip and its more favorable intensity distribution, as well as the better homogeneity of the stock resulting, are also factors which favor the use of these hydraulic headboxes.
As opposed to these advantages, however, hydraulic headboxes have presented certain difficulties as a result of the pressure variations referred to above. Thus in many instances it has been necessary to provide a headbox initially meant to operate as a fully hydraulic headbox with one or more separate air tanks which tend to be a substitute for the air cushion in an air cushion headbox. Various designs are known with respect to the situation of such separate air tanks. Thus in some designs these air tanks are connected to the pulp stock pipe system in advance of the headbox, while in other designs these air tanks are situated above the headbox itself and connected to the upper part of the headbox by suitable connecting tubes or by a connecting duct.
However, these latter designs have a serious drawback in that an air tank situated above the headbox necessitates a relatively great height for the free liquid level over the central axis of liquid flow, or the communicating tubes or duct from the headbox to the air tank must be dimensioned in such a way that they are relatively narrow as compared with the main flow duct. In either case the damping capability is impaired, as contrasted with the pressure variation damping capacity of a normal air cushion headbox.
SUMMARY OF THE INVENTION
It is accordingly a primary object of the present invention to provide in the approach pipe system which delivers the pulp suspension stock to a headbox, a damping structure which will avoid the above drawbacks.
In particular it is an object of the present invention to provide for damping or pressure and flow rate disturbances while maintaining adequate air volume, a relatively large free surface, a distance from the flow duct to the free surface which is as small as possible, preventing admixture of air and accumulation of air along the flow path, and simplicity as well as reliability and durability of the construction, particularly in connection with start-up and shut-down, and also having the possibility of self-cleaning of the flow duct.
According to the invention there is situated in the approach pipe system which delivers the pulp suspension to the headbox a tank means which has in its interior an upper gas space and a lower liquid space adapted to contain a liquid the upper surface of which contacts the gas in the gas space. Within this tank means there is a diaphragm means which defines with the tank means a flow space for the pulp suspension, this flow space being separated from the liquid space by the flexible diaphragm means. Supply and discharge pipe means respectively deliver and discharge flow suspension to and from the flow space of the tank means, while the gas in the gas space acts through the liquid in the liquid space and the diaphragm means on the flow suspension flowing through the flow space to damp pressure and flow rate disturbances in the pulp suspension flow. Preferably the flow space is of an annular configuration surrounding the liquid space which is filled with a liquid such as water or the equivalent thereof, this liquid communicating at its upper surface with the gas space which may, for example, be filled with air.
BRIEF DESCRIPTION OF DRAWINGS
The invention is illustrated by way of example in the accompanying drawings which form part of this application and in which:
FIG. 1 is a schematic elevation of a damping structure of the invention shown with the lower part of a tank broken away to illustrate in section details of the structure of the invention which are situated within the tank;
FIG. 2 is a top plan view of the structure of FIG. 1;
FIG. 3 is a fragmentary schematic sectional plan view taken at the elevation of a supply pipe and showing a variation of the structure of FIGS. 1 and 2; and
FIG. 4 is a fragmentary sectional plan view taken at the elevation of a discharge pipe and also showing a variation of the structure shown in FIGS. 1 and 2.
DESCRIPTION OF PREFERRED EMBODIMENTS
Referring to FIGS. 1 and 2, there is schematically illustrated therein part of an approach pipe system for delivering a pulp suspension to a headbox in the manner schematically indicated. The structure of the invention includes a cylindrical tank means 10 which has an upright central axis and which is of a circular configuration in planes normal to this axis, while having substantially flat upper and lower ends. The upper end 10b of the tank means 10 is provided with a manhole 15 which is normally closed by a removable cover, as schematically illustrated. This cover fluid-tightly closes the upper interior portion of the tank means from the outer atmosphere. The lower end 10a of the tank means 10 is connected, as schematically illustrated, with a suitable drain pipe 18 which is provided with a valve as illustrated. Thus this drain pipe 18 is normally closed.
The approach pipe system includes a supply pipe means 20 for supplying a pulp suspension to the interior of the tank means 10, as indicated by the arrow F in . As is apparent from FIG. 2, the supply pipe means 20 communicates tangentially with the interior of the tank means 10. The approach pipe system also includes a discharge pipe means 22 which also communicates tangentially with the tank means 10 as is apparent from FIG. 2. As is apparent from FIG. 1, the discharge pipe means 22 is situated at an elevation higher than the supply pipe means 20, and the pulp stock suspension flows along the interior of the discharge pipe means 22 so as to continue its travel to the headbox, as indicated by the arrow F out . While the pipes 20 and 22 have the different elevations illustrated in FIG. 1, nevertheless these pipes have central axes which at least in the region of the tank means 10 are situated in a common vertical plane which is parallel to the central vertical axis of the cylindrical tank means 10.
The cylindrical wall of the tank means 10 includes a portion 19 which extends across the supply pipe means 20 and which is formed with perforations 19a, so that the pulp suspension flows through the foraminous wall portion 19 into the interior of the tank means 10. In a similar manner the wall of the tank means 10 has a portion 21 formed with openings 21a through which the pulp suspension discharges into the discharge pipe means 22, so that the pulp suspension also is required to flow through the foraminous wall portion 21 before reaching the discharge pipe means 22.
Situated in the interior of the tank means 10 is a diaphragm means 12 which is made of a flexible fluid-tight sheet material and which is preferably, though not necessarily, elastic. Thus the diaphragm means 12 may be made of an elastomeric sheet material such as rubber. The diaphragm means 12 has a lower flange 12a fixed directly to the outer peripheral portion of the lower wall 10a of the tank means 10. Also the diaphragm means 12 has an upper portion 12b fixed to a flat ring 14 which is fixedly carried by the wall of the tank means 10 in the interior thereof, this flat circular ring 14 being situated in a plane normal to the central upright axis of the cylindrical tank means 10. Thus it will be seen that the diaphragm means 12 is also of a cylindrical configuration, being coaxial with the tank means 10, and defining with the wall portion thereof which surrounds the diaphragm means 12 a flow space 11 which is of an annular configuration and which is adapted to receive the pulp stock suspension while it flows from the supply pipe means 20 to the discharge pipe means 22. As indicated by the arrows F c in FIG. 2, the pulp suspension flows in the flow space 11 from the supply pipe means 20 to the discharge pipe means 22 along an ascending helical path.
It is to be noted that it is not essential to utilize foraminous or perforated wall portions 19 and 21 for the tank means at the location of the supply and discharge pipe means. Instead, as shown in FIGS. 3 and 4, the tank means 10 can be formed at its outer wall with simple openings 20a and 22a through which the pipes 20 and 22 respectively communicate with the flow space 11. However, in this event the diaphragm means 12' is suitably reinforced with a reinforcing means at the locations of the diaphragm means which are in alignment with the openings 20a and 22a. For this purpose in the illustrated example the diaphragm means 12' is provided with vertically extending ribs 30 which may be integrally formed with the sheet material of the diaphragm means and which are situated at least at the portion of the diaphragm means which is in alignment with the openings 20a and 22a. Thus, either by way of the perforated wall portions 19 and 21 or by way of the reinforcing ribs 30 of FIGS. 3 and 4 the diaphragm means 12 is prevented from being deflected excessively at the locations where the pulp stock suspension flows respectively into and out of the flow space 11.
The flexible diaphragm means 12 surrounds an interior liquid space A in the tank means 10, this space A being adapted to be filled with a suitable liquid such as water, and the liquid in the liquid space A extends to an elevation somewhat higher than the diaphragm means. Thus the liquid in the space A is shown in FIG. 1 as having an upper surface S.
Situated within the tank means 10 is an upper gas space V, this gas space being adapted to be filled with a gas such as air maintained at a suitable pressure. Thus, the liquid in the liquid space A operates in such a way that it transmits movement of the diaphragm means 12 to the gas space V which forms the capacitance of the damping system and which of course occupies the space within the tank means 10 which is above the liquid surface S. A tube 17 communicates with the gas space V for introducing a suitable gas such as air under pressure into this gas space, this tube 10 communicating, for example, with an air compressor or with a tank of compressed air. The liquid supplied to the liquid space A is delivered to the interior of the tank through a liquid-supply pipe 16 communicating with any suitable source of liquid. Of course when the structure is not used the liquid can be drained out of the space A through the drain pipe 18.
Within the liquid space A, which is separated from the flow space 11 by the diaphragm means 12, there is a foraminous plate 13 in the form of a cylindrical member formed with openings passing therethrough and situated coaxially in the tank means 10 within the space surrounded by the diaphragm means 12. This perforated cylindrical wall 13 is provided at its top end with a flange which is fixed to the inner peripheral portion of the flat ring 14 so that in this way the position of the perforated, foraminous cylindrical wall 13 is determined within the tank means 10. The purpose of the plate 13 is to protect the diaphragm means 12 against excessive sudden expansion inwardly toward the axis of the tank means, in the event that there is for any reason a sudden drop in pressure in the gas space V. Thus if for any reason pressure should escape from the gas space V, the diaphragm means 12 will be protected by the foraminous wall 13. The outer wall of the tank means 10 which surrounds the diaphragm means 12 serves to protect the latter in the event that there is a pressure surge in the opposite direction. Thus it will be seen that the diaphragm means 12 can be deflected outwardly away from the axis of the tank means 10 only until the diaphragm means 12 engages the inner surface of the wall of the tank means 10.
The height of the liquid in the liquid space A is arranged so as to be relatively small as compared with previously known vertical damping tanks, for example. In this way there is the advantage that the distance from the flow duct to the liquid surface S is minimized. The height h of the tank means 10 is in a range which may as a minimum approximately equal the magnitude of the diameter D of the tank means 10 and which as a maximum will be approximately equal to twice the magnitude of the diameter D of the tank means 10. The height h m of the diaphragm means 12 is approximately one half of the tank height h. The height h s of the liquid surface S which transmits the pressure between the gas space V and the diaphragm means 12 is preferably only slightly greater than the height h m of the diaphragm means 12. Thus the height h s may be on the order of, for example, 5--20% greater than the height h m of the diaphragm means 12.
As contrasted with known damping structures which include elastic diaphragms, the structure of the invention achieves a particular advantage, among others, that by utilizing an intermediate liquid the diaphragm means of the invention is in its normal state (i.e. in the median position of its oscillatory movement) free of stresses inasmuch as it is not subject to hydrostatic heads of different heights. As a result the elastic force of the diaphragm means does not detract from the capacitance of the damping system and thereby from the damping capacity thereof. Of course, as is pointed out above, the diaphragm means need not be made of an elastic sheet material. In other words the sheet material used for the diaphragm means of the invention need not be stretchable. It can also be made of a flexible sheet material provided with a non-stretchable supporting fabric.
Inasmuch as with the structure of the invention the discharge pipe means is situated at an elevation higher than the supply pipe means, there is a reduction in the possibility of accumulating air in the pulp suspension flow. Furthermore, the structure of the invention is advantageous in that high-quality steel surfaces required are relatively few and small in size.
In addition, there is provided a flow which is free of vortices and which has no dead locations in which the pulp suspension can accumulate without flowing. This latter factor leads to lesser possibility of soiling and clogging the apparatus. With the invention there is also the advantage that the tank means has a relatively small height which, as pointed out above, need only be on the same order as the diameter of the tank, or which at most is only about twice as great as the diameter of the tank, so that in this way the space required by the structure of the invention is relatively small.
Of course, the invention is not to be narrowly confined to the specific examples illustrated in the drawings and described above. The details of the invention may of course vary within the scope of the inventive concept defined by the claims which follow. | An approach pipe system which delivers pulp suspension to the headbox of a paper machine includes a tank having in its interior an upper gas space and a lower liquid space adapted to contain a liquid the upper surface of which contacts the gas in the gas space. In its interior this tank carries a flexible diaphragm which defines with the tank a flow space separated from the liquid space by the flexible diaphragm. A supply pipe communicates with this flow space for delivering a pulp suspension thereto while a discharge pipe also communicates with the flow space for receiving a pulp suspension therefrom and for continuing the travel of the pulp suspension to a headbox. The gas in the gas space acts through the liquid in the liquid space on the diaphragm to damp pressure and flow rate disturbances in the pulp suspension flowing toward the headbox. | 3 |
BACKGROUND OF THE INVENTION
This invention relates to apparatus with which manual knitting operations can be performed to produce diverse types of knit fabrics.
It is an object of the invention to provide apparatus of a simple and economical construction which can be used with a minimum of instruction to perform diverse types of knitting operations and produce various different types of knitted fabrics.
It is another object of the invention to provide a knitting apparatus on which different forms of stitches and different knitting patterns can be produced by suitable manual manipulation of hooked needles used in conjunction with stationary knitting supports.
It is still another object of the invention, in one of its aspects, to provide a simple apparatus on which knit fabrics can be readily produced by manual operation, utilizing a plurality of yarns of different color and/or character while minimizing the possibility of such yarns becoming entangled during the knitting process.
It is a further object of this invention, in another of its aspects, to provide an apparatus on which knit fabrics can be produced having different spacing between selected stitches.
It is a still further object of the invention to provide apparatus on which a knitted fabric can be produced and into which velour or like staples can be incorporated to provide a pile fabric.
BRIEF SUMMARY OF THE INVENTION
In accordance with the invention, apparatus for use in producing knit fabrics comprises a plurality of upright supports with axially slotted upper end sections on which stitches are produced and on which the knitted fabric is supported and at least one hooked knitting needle having a pair of threading eyes for carrying a knitting thread or yarn and which is used to manipulate the yarn in conjunction with the stationary supports to produce the stitches.
One preferred embodiment of the invention, particularly useful in producing multi-colored knit fabrics comprises a pair of upright supports of rod-like form mounted on a base frame which has a series of holder devices on each side of the supports for a plurality of hooked needles, each of which needles can carry a thread or yarn from a different yarn supply. In use, the needles are all initially positioned in the holder devices on one side of the supports. When a particular yarn is required for knitting, its needle is manipulated in conjunction with the supports to form the requisite stitches and stitch rows and the needle is then placed in a holder device on the other side of the supports. The process can then be repeated with other selected needles and when all required needles have been moved across from one side to the other, the entire procedure can be reversed.
In another preferred embodiment of the invention particularly useful for producing knit pile fabrics or knit fabrics with variable stitch spacing, the apparatus comprises a series of relatively squat slotted supports arranged in line or around the circumference of a circle. This arrangement is primarily intended for use with a single hooked yarn-carrying needle which is manipulated in conjunction with selected supports in turn to form and support rows of stitches into which velour or like staples can be incorporated if required to form a pile fabric.
BRIEF DESCRIPTION OF DRAWINGS
In the accompanaing drawings, which illustrate the invention by way of example:
FIG. 1 is a perspective, semi-diagrammatic view of a first form of knitting apparatus shown in the course of stitch production;
FIGS. 2, 3 and 4 are detailed perspective views of part of the apparatus of FIG. 1 shown in different stages of stitch production;
FIG. 5 is a side view of the forward end of one of the yarn-carrying needles of the FIG. 1 apparatus;
FIGS. 6 and 7 are respectively a plan view and an elevation of a support structure of a second form of knitting apparatus;
FIGS. 8-12 are perspective views of a support of the apparatus of FIGS. 6 and 7 shown in progressive stages of stitch production;
FIG. 13 is a perspective view of a further form of knitting apparatus of the type shown in FIGS. 6 and 7; and
FIGS. 14-17 are perspective views of one of the supports showing progressive stages in the incorporation of a velour or like staple into a stitch to produce a pile fabric.
DETAILED DESCRIPTION OF PREFERRED EMBODIMENTS
The apparatus shown in FIGS. 1-5 comprises two suitably shaped support rods 1 and 2 which act in a similar manner to conventional knitting needles. At their free upper ends, the two rods have longitudinal notches or slots 5 and 6, 2 to 3 centimeters long. The rods themselves are about 30 to 40 centimeters long and pass through two collets 9 and 10 attached to a base member support 3. The rods themselves are secured to a downwardly depending lower section of the base member at locations 7 and 8. The two collets are open at the front as shown and have a diameter greater than the rods so that the rods can slide in the collets when they hold a knit fabric. The dimensions of the longitudinal openings 17 of the collets are such as to let the manufactured knitting on the rods pass through the collets while preventing the rods themselves from passing through the openings. The support 3 has an elongate form in the horizontal plane and to the right and left of the rods, the support has an upper section formed an equal number of grooves forming holders for a plurality of hooked needles 11-16 each of which carries the yarn from a separate cone or ball as diagrammatically shown in FIG. 1.
The hooked needles 11-16 as shown in FIG. 5 have substantially planar, curved forward ends and have a pair of eyes 30 and 32, eye 30 being located at a forward tip of the needle and eye 32 being located at the rear of the curved forward end on a projecting portion 33 of the needle. As clearly shown the eyes each have an axis perpendicular to the plane of the curved forward end of the needle. Further, the needles are channel-shaped in cross section up to an intermediate point approximately at the crest of the curved portion and the remainder of the curved portion up to the tip is an extension of one wall only of the channel. The needles are threaded with the yarn 18 from a yarn supply first through eye 32, the yarn then extending along the needle channel and passing through eye 30 onto the rods 1 and 2.
In operation, as shown in FIG. 1, there are six needles, 11, 12, 13, 14, 15 and 16 which can be used with different yarns as to color and/or quality. For knitting, each needle is manipulated with the rods 1 and 2 in turns according to the pattern and the type of knitting fabric to be obtained. When one needle has completed a knitting operation, it is deposited in a groove on the support 3, on the side opposite that from which it was taken before starting the knitting operation. In FIG. 1 needle 11 is shown with the yarn which has already been used and put down in groove 29. While this needle was in operation, the other needles 12, 13, 14, 15 and 16 were deposited in grooves on the right of the rods 1 and 2.
FIG. 1 shows needle 16 in the process of forming a stitch, the needle being shown in the position it occupies when taking over a loop 19 present on rod 2. To do this, the needle must be introduced by its tip into notch 6 of rod 2, and to carry out this operation it should be noted that before the tip of the needle goes beyond the notch, the loop 19 has been moved upwardly, so that the tip of the needle can hook the loop in question. Then, the needle is raised so that the loop 19 leaves the rod 2 and remains on the needle held by the needle projection 33. In FIG. 2, the stitch has been passed onto needle 16 and the needle with stitch 19 is then moved over to rod 1 so that the rod is introduced between the curve of the needle and the section of the yarn 18 coming from the ball. Then the needle is pulled in the direction indicated by arrow 23, so that section of thread 18 remains hooked on rod 1 and loop 19, previously from rod 2, leaves the needle and is cast off into the knit fabric. The needle, having formed the stitch, is free to carry out the same operation on loop 20, and then on loop 21 and all the way down the row of stitches on rod 2. When the hook has completed the row, it is deposited in the groove next to needle 11 and the same operation is repeated with one of the needles 12, 13, 14 or 15. When all of the needles have been used to take stitches from rod 2 and cast them off onto rod 1, the needles have been deposited into grooves on the side of rod 1. The work is then turned around and the operation is repeated taking stitches from rod 1 and casting them off onto rod 2 and passing the needles into the grooves on the side of the rod 2.
It will be understood that the apparatus can be operated with more or less needles than the six shown in FIG. 1 (depending on the number of different yarns to be used) and if only a single yarn is to be used, knitting can be performed with a single needle.
A method of joining two adjacent loops formed by two threads coming from different supplies of different color or quality is shown in FIG. 3. Thread 25 has already made loops 27 and 28 and the respective needle is not shown in the drawing. The thread 24 carried by needle 16 must, before it takes up loop 26, be passed under thread 25, then the operation of casting on and off of the stitch is carried out, taking loop 26 and then casting off the section of thread 18 on rod 1 in the same manner as explained above. After this operation has been carried out, needle 16 is brought back by pulling it from below thread 25 and in executing this operation the hand should not let go of the needle. Stitches formed by threads 24 and 25 are thus joined while the respective threads have not crossed but have remained parallel down to the thread supplies. This operation is repeated whenever needles are changed.
Forming a purl stitch as shown in FIG. 4 differs from the formation of a plain stitch as described above in only one detail, which is that the tip of needle 16 takes the loop 19 not from above, but from below.
To reduce the number of stitches in a row by one stitch a needle must take two loops together and cast only its own thread onto the other rod. To increase the number of stitches in the row by one stitch, the hook must not take any loop off the rod from which it casts off, but with its thread must form a new loop on the loading rod.
FIGS. 6-17 illustrate an alternative form of apparatus in accordance with the invention which employs a series of knitting supports 50 arranged in spaced relation on a base member 51 either around the periphery of the circle as shown in FIGS. 6 and 7 to produce tubular knit fabrics, or in a line as shown in FIG. 13 to produce knit fabric in sheet form. This type of apparatus is primarily intended for use with a single hooked needle 56 and can be operated to produce fabrics having a variable stitch spacing by omitting one or more supports as shown in FIG. 13 or to produce pile fabrics by the incorporation of staples as shown in FIGS. 14-17.
The supports 50 again have longitudinal slots 61 in their free upper ends and the outer faces are longitudinally grooved as shown to facilitate needle insertion as shown for example in FIG. 9. Needle 56 is similar in form to the needles described with reference to FIGS. 1-5 and has a substantially planar curved forward end with a pair of spaced eyes with axes perpendicular to that plane of the forward end and with yarn from a ball being threaded in use through the rear eye and then through the forward eye as shown. In this embodiment, however, the rearward eye of the needle is shown as being located substantially on the crest of the curved forward end of the needle.
In use, stitches are formed successively on individual supports by suitable manipulation of yarn-carrying needle 56, with the needle 56 carrying thread 60 from a supply having the function of taking loops off the supports 50 and discharging them into the fabric, at the same time preparing on the supports a new row of stitches for the next course. To take loops from the supports one or other of two different operating modes may be used.
In FIG. 8, for example, needle 56 has been introduced in notch 61 with the needle tip under loop 58 of a previously formed stitch. Alternatively, (FIG. 9) the needle can be introduced under loop 58 but upside down and on the outside of the support. After having operated by one of these two modes, the needle is raised from the support together with loop 58 (FIG. 10) leaving the support empty. In FIG. 11 the needle has been lowered again so that its thread 59 coming out of the tip of the needle is arranged around the perimeter of the support. Subsequently, FIG. 12, the needle is pulled back so that loop 58 leaves the needle and is released into the already formed knit fabric and the section of thread 59 forms a new loop around the perimeter of the support. This operation is then repeated on selected succeeding supports returning to the support first operated on. As shown in FIG. 13, the central support has been excluded from the operation to obtain greater spacing between a pair of stitches. In the arrangement shown in FIGS. 6 and 7, there are thirty-six supports to form a row with a maximum of thirty-six stitches. This operation can be operated leaving one or more supports idle in order then to return to them in the same row or in one of the following rows, or one can operate several times on the same supports. Also circular knitting can be effected. To produce pile fabrics, the procedure for adding pile staples to the knit fabric is shown in FIGS. 13-17. In FIGS. 13 and 14 a staple 62/63 has been placed on a support 50 above loop 59 which forms part of the fabric already knitted. In FIG. 15 a separate hook 57, not carrying other yarn, has been introduced with its tip under loop 59. Then the two ends of the staple are hooked to the hook. In FIG. 16 the hook protected by the two walls of notch 61 has been pulled above the support together with the two ends of the staple, without running into the loops to be protected which are present on the outside of the walls of the support. In FIG. 17 the part of the staple 62 which forms a loop 63 has been raised and hence freed from the support, so that a knot can be formed held only by loop 59. The knot having been formed, knitting is resumed as in FIGS. 8-12 thereby incorporating a pile staple into the knit fabric.
While the present invention has been described with reference to particular embodiments thereof, it will be understood that numerous modifications can be made by those skilled in the art without departing from the scope of the invention as defined in the appended claims. | Apparatus for manually producing a knit fabric comprises at least a pair of upright knitting supports with slotted top sections on which the fabric is produced and supported, and at least one curved needle having a pair of yarn-threading eyes, which needle carries yarn from a yarn supply and is manipulated in conjunction with the supports to produce stitches thereon. | 3 |
BACKGROUND OF THE INVENTION
The invention relates to an auxiliary device for use with a seam weaving machine serving to join the ends of a synthetic resin fabric flat-woven from longitudinal and transverse threads by forming a woven seam. Such a woven seam is formed from the exposed ends of the longitudinal threads used as weft threads and from the auxiliary warp threads in a weaving operation by means of the seam weaving machine. The auxiliary device serves to couple the auxiliary warp threads to tensioning strings in order to exert the required tension on the auxiliary warp threads required for forming the shed.
In general, transverse threads are used as auxiliary warp threads which are obtained by fraying a strip of the fabric to be provided with a woven seam. Said transverse threads have only limited length, namely a length corresponding to the width of the synthetic resin fabric. The weights used for tensioning the auxiliary warp threads therefore cannot be fastened to the auxiliary warp threads themselves and are fastened to tensioning strings which, in turn, are coupled to the auxiliary warp threads.
Regarding the seaming technique for joining the ends of flat-woven papermachine fabrics reference is made generally to the publication by B. Krenkel in "Das Papier", No. 3, 1984. page 100 et seq. An automatically operating seaming machine for synthetic resin fabrics is described in EP-B-O No. 043 441 where before the beginning of the seam of each papermachine fabric a multiplicity of very closely spaced auxiliary warp threads (up to 448 auxiliary warp threads) are individually tied to or adhered to the ends of the tensioning strings. The tensile force on the individual auxiliary warp threads required for the seam weaving operation ranges between about 70 and 240 N, depending on the type of fabric, and is generally achieved in that each tensioning string end is weighted with a corresponding weight. This tying or adhering of a multiplicity of auxiliary warp threads to tensioning strings is not only very time-consuming but it also brings about the risk of confusion or other imperfections which are not noticed until after weaving and which therefore can be eliminated only with great difficulties later on. If the thread ends are manually adhered or tied together an excessively high tension is easily exerted on the auxiliary warp threads, which may be so high as to cause breakage of the thread.
SUMMARY OF THE INVENTION
Therefore, the invention has the object of providing an auxiliary device for a seam weaving machine by which coupling of the auxiliary warp threads to the tensioning strings is simplified.
According to the invention, this object is realized by a coupling device for coupling each individual auxiliary warp thread to a tensioning string, said device comprising a barbed needle in a guide sleeve, said barbed needle having at one end a barb for seizing an auxiliary warp thread, while the other end is connected to a tensioning string. For coupling the two threads the end of the auxiliary warp thread is placed into the barb and the guide sleeve is pushed over the barb so that the free end of the auxiliary warp thread is folded back and firmly held by friction between the barb and the guide sleeve.
Furthermore, a storage plate is preferably provided which has bores for receiving a coupling device in each bore. The storage plate readies the coupling devices for coupling in a predetermined order so that the operator merely needs to pull them somewhat forwardly out of the storage plate in order to effect coupling to the auxiliary warp threads. The forward end of the guide sleeve facing the barb is widened, for example, to provide a stop in order that the coupling devices will not be pulled through the bores in the storage plate by the weights hanging from the tensioning strings. Preferably, the guide sleeve is provided to this end with lateral flattened portions adjacent the central region and a widened portion inbetween. The lateral flattened portions preferably serve at the same time as guide faces for a barbed needle having a flat shaft of rectangular cross-section.
To prevent the barbed needles from being pulled rearwardly out of the guide sleeves by the tensioning strings coupled thereto, they are preferably provided with a widened or thickened portion adjacent the forward end provided with the barb.
In order to couple the auxiliary warp threads of a fabric to be made endless by forming a woven seam the coupling means disposed in the holes bored along a vertical line in the storage plate are first twisted and aligned so that the longitudinal axes of the flattened portions of the guide sleeves are in alignment. To this end, a tweezers or a similar tool is pushed over the respective vertically spaced guide sleeves, and the two arms of the tweezers are pressed together so that the flattened portions of the coupling sleeves are vertically aligned.
The barbs of the barbed needles are then oriented upwardly or downwardly, but by no means sideways. After this alignment operation, the vertically spaced and aligned coupling means are seized by means of an adapter and are removed from the storage plate. The adapter is shaped as a fork with two parallel prongs spaced apart a distance corresponding to the width of the coupling means at the laterally flattened portions. By means of the adapter, the coupling means are pulled forward about 200 mm away from the storage plate and secured in this position. For initiation of a coupling operation for a particular auxiliary warp thread, the barbed needle is first pushed forwardly so that the barb is exposed. The auxiliary warp thread is placed into the barb, and by pulling the barbed needle at the other end, the latter slides back into the guide sleeve thereby carrying the inserted auxiliary warp thread along. This operation is repeated with all the vertically spaced coupling means seized by the adapter. Then the coupling means are removed from the adapter and take their operative position which is located about 200 mm before the storage plate and in which the tension is transmitted by the tensioning strings to the auxiliary warp threads. By means of the adapter, the next row of superposed coupling means is then seized, and so on.
In order to uncouple the group of auxiliary warp threads after the formation of a woven seam, a major number, preferably the superposed eight of said auxiliary warp threads, are simultaneously pulled out of their guide sleeves and thus uncoupled. The ends of the auxiliary warp threads then drop loosely from the barbs of the coupling means and the individual coupling means are then guided into their initial ready-for-use position in the storage plate.
The advantages attainable by the invention particularly reside in the simple and safe handling of the coupling means, in a substantial saving of time, and in the possibility of handling a plurality of coupling means by a simple fork-like adapter.
BRIEF DESCRIPTION OF THE DRAWINGS
FIG. 1 shows a general view of a portion of a seam weaving machine serving to tension the warp threads;
FIG. 2 shows the coupling means with a coupled auxiliary warp thread;
FIG. 3 is a section along 3--3 in FIG. 2;
FIG. 4 shows the coupling means of FIG. 2 with the barbed needle extended:
FIG. 5 shows the adapter with a coupling means held therein, and
FIGS. 6 and 7 show the adapter in two lateral views rotated 90° relative to one another; and
FIG. 8 illustrates the coupling means as applied to the storage plate.
DETAILED DESCRIPTION OF THE INVENTION
FIG. 1 shows a portion of a seam weaving machine which produces the required tension for the auxiliary warp threads 1. The tension is transmitted by tensioning strings 2 to the auxiliary warp threads 1, while the auxiliary warp threads 1 and the tensioning strings 2 are linked together by coupling means 13.
A plurality of tensioning strings 2, only one of which is shown in FIG. 1, which are to be coupled individually to an auxiliary warp thread 1 are guided around a cross bar 3 in the form of a gallows and are held under constant tension by weights 4. The weights 4 may have the form of small rods of 12 g mass since up to 448 tensioning strings 2 may be tightened simultaneously. The weights 4 consist of stainless steel and are each provided with an eye on top for threading the associated tensioning string 2. The ends of the tensioning strings 2 are threaded through squeeze tubelets 5 above the weights 4 which are then tightened by clamping. In order to prevent entanglement of the great number of weights 4 and to keep them mobile and in good order, the individual weights are guided through two perforated plates 6 screwed to the cross bar 3 before they are introduced into the weight box 7 provided for protection against external influences.
Each tensioning string 2 weighted down by a weight 4 is diverted to a horizontal plane by a grid 8 of known design and is guided toward a storage plate 9 secured to the front end of the horizontal portion of the gallows-like bar 3. The storage plate 9 has a bore 14 for each tensioning string 2 to be coupled to an auxiliary warp thread 1 for receiving a coupling means 13. In the storage plate 9, the bores 14 are arranged in eight horizontal rows of 56 individual bores each.
Each coupling means 13 includes a guide sleeve 10, having, for example, an external diameter of 1 mm and an overall length of 22 mm for an auxiliary warp thread 1 having a diameter in the range of 0.16 to 0.22 mm. For auxiliary warp threads 1 of a diameter within the range of 0.22 to 0.30 mm a guide sleeve of equal length but of an external diameter of 1.1 mm is used. A needle 11 is located in each guide sleeve 10 and is provided at its leading end with a barb 15 for sizing an auxiliary warp thread 1 and at its rear end with an eye 16 for tying a tensioning thread 2.
The tensile force produced by the weights 4 and transmitted by the tensioning strings 2 to the barbed needles 11 pulls the coupling means 13 into bores 14 in the storage plate 9 which provide seats for rotation of the coupling means 13. The guides sleeves 10 have slightly oval cross sections at both ends, while in the middle they are compressed into a highly oval cross section with lateral flat portions 19, as is apparent from FIGS. 2 and 3. This ensures positive engagement between the bores 14 in the storage plate 9 and the guide sleeves 10 to prevent the sleeves 10 from being pulled through the bores 14.
In the coupled state illustrated by FIG. 2, the barbed needle 11 has been drawn rearwardly into the guide sleeve 10 up to the abutment 18. The auxiliary warp thread placed into the barb 15 is pressed between the guide sleeve 10 and the barb 15 as shown in FIG. 3 and the end of the auxiliary warp thread 1 is covered by the guide sleeve 10, i.e. it is invisible and thus cannot interfere with the adjacent auxiliary warp threads 1.
For release or uncoupling of the group of auxiliary warp threads 1, the auxiliary warp threads 1 and needles 11 are simultaneously pulled out of their guide sleeves 10 while the latter are held in position. Thereafter the tension applied by each weight 4 draws the coupling means back into the bores 14 in the storage plate 9, as shown in FIG. 8.
For coupling the individual auxiliary warp threads 1 of a paper machine fabric to be made endless by means of a woven seam coupling means 13 disposed in the bores 14 vertically spaced in rows in the storage plate 9, are aligned with a pair of tweezers or the like so that all the guide sleeves 10 are disposed in the position shown in section in FIG. 3. In this position all the guide sleeves with their pronouncedly dual cross section are in vertical alignment. To accomplish this the tweezers are pushed over the vertically superposed coupling means 13 and compressed so that the pronouncedly oval central portions align themselves in the longitudinal direction of the tweezers. i.e., in the vertical direction. Upon achieving this alignment the barbs 15 of the barbed needles 11 are then automatically aligned in an upward or downward direction but by no means in a lateral direction.
After this alignment operation, the vertically arranged coupling means 13 are seized by means of a fork-like adapter 12 (FIGS. 6 and 7) in that the fork-shaped adapter 12 which is similar to a pair of tweezers, is pushed over the pronouncedly oval central portions of the coupling means 13. By way of the adapter 12, the coupling means 13 in a single row of eight are then removed from the storage plate 9, and the adapter 12 together with the coupling means 13 held between its two arms 17 is held in an adapter seat some distance, e.g. 200 mm, away from the storage plate 9; see FIG. 5. The relative position of said guide sleeve 10 and barbed needle 11 is initially the same as shown in FIG. 2, i.e. the barbed needle 11 is pushed fully back into the guide sleeve 11 so that the widened head 18 of the barbed needle 11 abuts against the forward end of the guide sleeve 10 Each barbed needle 11 is then pulled out of the guide sleeve 10 so that the barb 15 becomes accessible (see FIG. 5) and now the auxiliary warp thread 1 to be coupled is placed into the barb 15. By the application of tension at the rear end of the barbed needle 11 the latter is again pulled into the guide sleeve 10 carrying along the inserted auxiliary warp thread 1, the coupling means 13 is no longer pulled back into the storage plate 9 by the tensioning string 2 and remains at a point shortly behind the adapter position. The location of this point depends on the length of the free ends of the auxiliary warp thread 1 extending from the end of the papermachine fabric which is to be joined to the other end by a woven seam.
After this coupling operation is completed for all the vertically spaced coupling means 13 held by the adapter 12, said coupling operation is repeated by means of the adapter 12 for the next row of vertically spaced coupling means 13, and so on, until all the auxiliary warp threads 1 required for a woven seam are coupled to tensioning strings 2.
The use of an adapter 12 is not required in each case. The coupling means 13 can also be seized singly by hand in order to couple them to the auxiliary warp threads 1. Moreover, the central portions of oval cross-section are not necessary. Slipping of the coupling means 13 through the storage plate 9 can be prevented, for example, also by forming the bores 14 as shoulder bores widened in front, or by providing the coupling means 13 with an external bead at the leading end. Instead of the widened heads 18 at the leading ends of the barbed needles 11, the barbed needles can have a smaller dimension at the rear ends in the region of the eyes 16 so that they bear against a constriction at the rear ends of the guide sleeves 10. In that case it is not necessary that the barbed needles 11 have a rectangular cross-section. | An auxiliary device for a seam weaving machine for joining the ends of flat-woven fabrics by a woven seam couples each auxiliary warp thread to a tensioning string. The auxiliary device includes a barbed needle in a guide sleeve with the barbed needle having at one end a barb for seizing an auxiliary warp thread and holding it between the needle and the sleeve. The needle is connected at the other end to a tensioned string. A storage plate is provided having bores for receiving the coupling devices. | 3 |
TECHNOLOGICAL FIELD
[0001] The present invention is in the field of condition authentication or identification of a scattering object by using vibrational responsivity originated from the object.
BACKGROUND
[0002] Personal authentication systems using biological information, such as fingerprints, have recently been commercially available. The biological information utilizes, for example, a fingerprint, a palm print, a finger shape, a palm shape, voice, a retina, an iris, a face image, a dynamic signature, blood-vessel arrangements, or keystroke. The biometric information is superior in reliability to a password. Of biometric information, a fingerprint is used frequently.
[0003] In a personal authentication system using a fingerprint, a fingerprint is to be checked against all sample fingerprints by means of round-robin matching. For instance, the authentication system employs a matching method (matching technique) of so-called one-fingerprint-against-multiple-registered-fingerprints type (hereinafter simply called a “1-N fingerprint matching method”). Round-robin matching is a technique of checking a fingerprint against all the registered fingerprint data for matching purpose, in sequence from the top. If fingerprint data pertaining to a person of interest are coincidentally located at the head of the sequence, it is expected that matching processing can be terminated immediately without involvement of matching operation using a fingerprint pattern.
[0004] With regard to personal authentication using a fingerprint, various systems have so far been developed which, instead of the old-established method involving visual inspection, a laser, etc. is used and a pattern is inputted into a computer as an image and analyzed. A large number of techniques for a sensor section for detecting a fingerprint have been proposed; for example, an optical method in which a fingerprint pattern is directly captured into an image sensor by combining differences in scattering angle between peak and valley with total reflection conditions, and a method in which a pattern is extracted by utilizing a semiconductor sensor that detects differences in charge distribution on a contact face have been put into practice. Furthermore, a method in which personal authentication is carried out by extracting a vein pattern of a finger-tip or a palm of a hand by means of near-infrared light has been proposed.
GENERAL DESCRIPTION
[0005] The present invention relates to a method and system for condition authentication based upon temporal-spatial analysis of vibrational responsivity. Here, “object” may be a single element or subject, or a group of elements or subjects.
[0006] There is provided an object authentication method comprising the following steps: applying a stimulation field of a periodically changing stimulation frequency to an object; applying unfocused imaging to the object being stimulated, the unfocused imaging comprising illuminating the object by at least partially coherent light, collecting a plurality of sequential secondary speckle patterns, each originated from at least a portion of the object being stimulated, and generating image data indicative thereof, the image data comprising a sequence of the speckle patterns for each of the stimulation frequencies; and processing the image data, the processing comprising: segmenting each of the speckle patterns into a two-dimensional matrix of spatial regions; comparing the sequential speckle patterns to determine a spatial-temporal change of a correlation peak for each of the regions; determining the change in the correlation peak position in time in the two-dimensional matrix associated with two dimensional spatial locations along the inspected object image; determining a temporal frequency signature uniquely characterizing the at least portion of the object by calculating a temporal frequency profile of the two-dimensional correlation peak position per the stimulation frequency, thereby enabling authentication of the object. In some embodiments, the method comprises selecting a coherence length for the coherent illumination to provide a desired ratio between the size of the illumination spot and size of the speckles in the captured set of patterns. In this way, the spatial coherence is appropriately selected in order to allow illuminating a large area and yet having large speckles, inversely proportional to the coherence length of the illumination source (being shorter than the diameter of the illumination spot).
[0007] Therefore, the present invention relates to temporal tracking of reflected secondary speckle patterns generated when illuminating an object with a source of at least partially coherent beam and while applying a stimulated field (e.g. sinusoidal pressure stimulation) at different temporal stimulating frequencies via a support surface being for example a controlled vibration surface (CVS).
[0008] In some embodiments, the object comprises a body's part of at least one individual people. The body's part may be a passive soft tissue such as an individual's finger, or fingertip.
[0009] Alternatively, the method comprises applying stimulation to a body's part of a group of people. Each region of the two-dimensional matrix corresponds to the spatial signature authenticating an individual person.
[0010] In some embodiments, the periodic stimulation comprises applying sinusoidal pressure stimulation via the support surface contacting the object.
[0011] In some embodiments, the method comprises determining the temporal frequency range of the stimulation field variation. Indeed, the technique of the present invention determines the optimal temporal frequency range of the support surface contacting the object.
[0012] In some embodiments, the imaging step comprises collecting different portions of each secondary speckle patterns of the plurality of the secondary speckle patterns to reconstruct the full secondary speckle pattern of the object.
[0013] In some embodiments, the method comprises applying the stimulation field to an object being under dry and wet conditions and comparing the temporal frequency signature under the different conditions to provide a real-time scenario invariant (i.e. that remains unchanged when repeated under the same conditions) identification.
[0014] In some embodiments, the method comprises calculating a temporal frequency profile of a plurality of two-dimensional correlation peak positions per the stimulation frequency defining a spatial relationship of temporal frequency signatures for a plurality of two-dimensional spatial regions.
[0015] In some embodiments, the object comprises at least one rigid surface being a self-excited vibration surface. Such rigid surface may be a part of any mechanical systems including rotating machinery, machining tools, industrial turbomachinery, aircraft gas turbine engines etc.
[0016] In some embodiments, the stimulation field of the periodically changing stimulation frequency comprises a self-excited vibration field of the object. By applying the temporal-spatial analysis of vibrational responsivity as described above, the authentication of the object enables to determine a proper mode of functionality of the rigid surface as well as energetic consumption/tuning.
[0017] There is also provided a system comprising an object support surface configured for vibration in response to a stimulation field of a periodically changing stimulation frequency; an imaging device for performing defocused imaging of at least a portion of the object while on the support surface to thereby collect a plurality of sequential speckle patterns originated from at least a portion of the object while on the support being stimulated with the periodically changing stimulation frequency, and generating image data; and a processing unit adapted for processing the image data using stimulation field data, the processing unit being configured and operable to segment each speckle pattern into a two-dimensional matrix of spatial regions; compare the sequential speckle patterns to determine a spatial-temporal change of the correlation peak for each region of the two-dimensional matrix; determine the change in the correlation peak position in the two-dimensional matrix in time; and determine a temporal frequency signature uniquely characterizing the at least portion of the object by calculating the temporal frequency profile of the two dimensional correlation peak position per stimulation frequency, the temporal frequency signature being thereby enabled for use in determination of authentication of the object.
[0018] In some embodiments, the processing unit controls at least one stimulation field parameter applied to the support surface.
[0019] In some embodiments, the system comprises a source of a beam of at least partially coherent light. The source may include a highly coherent or partially coherent light emitting element.
[0020] In some embodiments, the system comprises a beam expander configured for expanding the spot of the beam on the object.
[0021] In some embodiments, the imaging device collects different portions of the plurality of the secondary speckle patterns reflected at a surface of the stimulated object.
[0022] In some embodiments, the support surface comprises a loud speaker controlled by the processing unit.
BRIEF DESCRIPTION OF THE DRAWINGS
[0023] In order to better understand the subject matter that is disclosed herein and to exemplify how it may be carried out in practice, embodiments will now be described, by way of non-limiting example only, with reference to the accompanying drawings, in which:
[0024] FIG. 1 a schematically represents a flow chart illustrating different steps of the technique of the present invention;
[0025] FIG. 1 b schematically represents a segmentation of the image data into a two-dimensional matrix of regions within a fingerprint image;
[0026] FIG. 2 a schematically represents a possible configuration of the system of the present invention according to some embodiments;
[0027] FIG. 2 b is a picture of the same;
[0028] FIGS. 3 a -3 c represent the temporal frequency signature of a fingerprint obtained by using the technique of the present invention for three different individual persons;
[0029] FIG. 4 a represents the temporal frequency signature of an index fingerprint obtained by using the technique of the present invention for a specific person; FIGS. 4 b -4 d represent the temporal frequency signature of an index, middle and ring fingerprints respectively obtained by using the technique of the present invention for a person different from the person tested in FIG. 4 a ; FIGS. 4 e -4 f represent the temporal frequency signature of an index, and ring fingerprints respectively obtained by using the technique of the present invention for a person different from the persons tested in FIG. 4 a and FIGS. 4 b -4 d ; FIGS. 4 g -4 i represent the temporal frequency signature of an index, middle and ring fingerprints respectively obtained by using the technique of the present invention for a person different from the persons tested in FIGS. 4 a - 4 f;
[0030] FIGS. 5 a -5 b illustrate the stability of the technique of the present invention by representing the temporal frequency signature of an index fingerprint of one person twice; FIGS. 5 c -5 e illustrate the stability of the technique of the present invention by representing the temporal frequency signature of an index fingerprint of a person different from the person tested in FIGS. 5 a -5 b three different times; FIGS. 5 f -5 g illustrate the stability of the technique of the present invention by representing the temporal frequency signature of a middle fingerprint for a person different from the person tested in FIGS. 5 a -5 e twice; and;
[0031] FIGS. 6 a -6 f represent the temporal frequency signature of middle and index fingerprints under dry and wet conditions respectively of different persons.
DETAILED DESCRIPTION OF EMBODIMENTS
[0032] The present invention relates authentication of an object using speckle patterns. Although the following examples are related to experiments aimed at determining fingerprint identification, it should be understood that the novel technique of the present invention should be used for any authentication of biometric information of a person, such as a fingerprint, facial image, voiceprint, retina pattern, iris pattern or the like. The imaging method may be used for imaging the object while moving. The movement may be associated with a vibration, e.g. of a living body's part. The vibration may correspond to a speech, a sequence of heart beats, a heart beat resolved to a heart beat's structure, as well as vibration of a cloth on a living body. The living body's part may be at least one of a hand joint, a chest, a throat, a temporal fossa, a stomach, a throat, a cheekbone, a head, a palm and a finger.
[0033] It should be noted that the size of the generated speckle can be estimated according to the following relation:
[0000]
δ
x
≈
λ
Z
min
{
D
,
L
}
[0034] where λ is the wavelength of the illuminating source, Z is the distance between the back reflecting object surface and the plane at which the specific speckle are generated. D is the diameter of the illumination spot and L is the coherence length of the partially coherent illumination source.
[0035] Referring to FIG. 1 a , there is schematically illustrated an object authentication method comprising the following steps: (1) applying a stimulation field of a periodically changing stimulation frequency to an object; (2) applying unfocused imaging to the object being stimulated, the unfocused imaging comprising illuminating the object by at least partially coherent light, collecting a plurality of sequential secondary speckle patterns, each originated from at least a portion of the object being stimulated, and generating image data indicative thereof, the image data comprising a sequence of the speckle patterns for each of the stimulation frequencies; and processing the image data, the processing comprising: (3) segmenting each of the speckle patterns into a two-dimensional matrix of spatial regions; comparing the sequential speckle patterns to determine a spatial-temporal change of a correlation peak for each of the regions; (4) determining the change in the correlation peak position in the two-dimensional matrix in time associated with two dimensional spatial locations along the inspected object image; (5) determining a temporal frequency signature uniquely characterizing the at least portion of the object by calculating a temporal frequency profile of the two-dimensional correlation peak position per the stimulation frequency, thereby enabling authentication of the object in step (6). According to the invention, in other words, the object thus is subjected to a stimulation field of a periodically changing stimulation frequency (frequency sweeping) and the so-stimulated object undergoes unfocused imaging using illumination by at least partially coherent light. It should be understood that using an unfocused imaging refers to using an imaging system being focused on a plane displaced from the object. Such imaging technique is described for example in the U.S. Pat. No. 8,638,991 of the same inventors of the present invention incorporated herein by reference. The image data, in the form of a plurality of sequentially acquired speckle patterns originated at the stimulated object each corresponding to a different stimulation frequency, is collected, and analyzed to determine a change in a two dimensional position of a correlation peak between the sequential frames in the time domain. To this end, as illustrated in FIG. 1 b , the processing includes segmenting the image data into a two-dimensional matrix of regions 100 within the object's image, each characterized by its dedicated parameter(s) of the correlation peak (e.g. position of the peak). As a result, the object's signature is obtained in the form of the correlation peak (intensity) as a two-dimensional position function per the stimulation frequency. This signature can then be verified using reference data for the authentication purposes. The novel technique of the present invention enables detecting personal identification with low rate of false alarms. The rate of false alarms is decreased by creating a segmented/sub-object data.
[0036] Reference is made to FIGS. 2 a -2 b illustrating a possible set up of the system of the present invention. The system 200 comprises an object support surface 202 configured for vibration in response to a stimulation field of a periodically changing stimulation frequency; an imaging device referred as camera 204 for performing defocused imaging of at least a portion of the object while on the support surface 202 to thereby collect a plurality of sequential speckle patterns originated from at least a portion of the object while on the support 202 being stimulated with the periodically changing stimulation frequency, and generating image data; and a processing unit 206 adapted for processing the image data using stimulation field data, the processing unit 206 being configured and operable to segment each speckle pattern into a two-dimensional matrix of spatial regions; compare the sequential speckle patterns to determine a spatial-temporal change of the correlation peak for each region of the two-dimensional matrix; determine the change in the correlation peak position in time in the two-dimensional matrix; and determine a temporal frequency signature uniquely characterizing the at least portion of the object by calculating a temporal frequency profile of the two dimensional correlation peak position per stimulation frequency, the temporal frequency signature being thereby enabled for use in determination of authentication of the object. It should be noted that all required processing operations (such as processing captured images, performing corresponding calculation operations, segmenting the speckle pattern into a two-dimensional matrix of spatial regions, comparing the sequential speckle patterns, determining a spatial-temporal change of the correlation peak for each region of the two-dimensional matrix, determining the change in the correlation peak position in time in the two-dimensional matrix, calculating a temporal frequency profile of the two dimensional correlation peak position per stimulation frequency, determining the frequency signature . . . ) may be performed by means of a processing unit 206 , such as a DSP, microcontroller, FPGA, ASIC, etc., or any other conventional and/or dedicated computing unit/system. The term “processing unit” should be expansively construed to cover any kind of electronic device with data processing capabilities, including, by way of non-limiting example, personal computers, servers, computing systems, communication devices, processors (e.g. digital signal processor (DSP), microcontrollers, field programmable gate array (FPGA), application specific integrated circuit (ASIC), etc.) and other electronic computing devices. The processor unit 206 may comprise a general-purpose computer processor, which is programmed in software to carry out the functions described hereinbelow. Although processing unit 206 is shown in FIG. 2 a , by way of example, as a separate unit from imaging device 204 , some or all of the processing functions of processing unit 206 may be performed by suitable dedicated circuitry within the housing of the imaging device or otherwise associated with the imaging device 204 . Unless specifically stated otherwise, as apparent from the following discussions, it is appreciated that throughout the specification discussions utilizing terms such as “processing”, “computing”, “calculating”, “determining”, “comparing”, “segmenting” or the like, refer to the action and/or processes of a computer that manipulate and/or transform data into other data, said data represented as physical, e.g. such as electronic, quantities. Also, operations in accordance with the teachings herein may be performed by a computer specially constructed for the desired purposes or by a general purpose computer specially configured for the desired purpose by a computer program stored in a computer readable storage medium. The processor unit 206 includes inter alia a signal generator, and at least one utility part (suitable software and/or hardware) for processing the image data using stimulation field data. The utility is preprogrammed to segment each speckle pattern into a two-dimensional matrix of spatial regions, compare the sequential speckle patterns to determine a spatial-temporal change of the correlation peak for each region of the two-dimensional matrix, determine the change in the correlation peak position in time in the two-dimensional matrix and determine a temporal frequency signature uniquely characterizing the at least portion of the object by calculating a temporal frequency profile of the two dimensional correlation peak position per stimulation frequency. The software may be downloaded to processing unit 206 in electronic form, over a network, for example, or it may alternatively be provided on tangible media, such as optical, magnetic, or electronic memory media. Alternatively or additionally, some or all of the functions of the processing unit 206 may be implemented in dedicated hardware, such as a custom or semi-custom integrated circuit or a programmable digital signal processor (DSP).
[0037] In some embodiments, the system comprises a source of a beam of at least partially coherent light 208 referred in the figure as an illumining laser. Optionally the illumining laser 208 is associated with a beam expander 210 in order to get a large spot on the object. In this way, the coherence length for the coherent illumination is appropriately selected to provide a desired ratio between the size of the illumination spot and size of the speckles in the captured set of patterns.
[0038] In the specific and non-limiting set-up used by the inventors of the present invention, the imaging device 204 was a camera of a model PixeLink PL-D721MU having an exposure time of 0.5 msec, a frame rate of 500, the number of frames acquired was about 5000, a scan time of about 10 sec, a signal gain of 0 dB; a Gamma non-linearity of: 2.2. The support surface 202 was a speaker of a model OSC LS13C050, 2¼″ Diameter, 50 ohm 0.5 Watt generating a sinusoidal wave at a frequency range of about 70-210 Hz and a voltage (Pk2Pk) of about 1.1 V. The source of a beam of at least partially coherent light 208 was a laser diode of a model Photop Suwtech Laser DPGL-2100F, having a wavelength of 532 nm max 100 mW with driver of a model Photop LDC-2500S having a driver current of 0.65 A, the beam expander used was of a model Thorlabs GBE05-A. The object was placed on the support surface 202 . The measured power of the laser 208 on the object was 10-12 mw. The processing unit 206 was connected to the imaging device 204 to process the image data and to the support surface 202 to control the stimulation field. In this example, the stimulation field is controlled by a signal generator such as Tektronix AFG1022 associated with the processing unit 206 . The signal generator may also be integrated with the processing unit 206 . The images of the secondary speckle pattern reflected from the object were captured at the rate of 400-600 fps. The processing unit 206 first extracts the speckle pattern in each frame and then calculates the change in the 2-D position of the correlation peak versus time due to the vibrations generated at the support surface 202 . The technique includes imaging of a coherent speckle pattern formed by an object or subject or, generally, a surface of interest. The pattern can be formed by illumination of the still or moving surface of interest by at least partially coherent light of a laser or another light source. Preferably, the surface movement includes a tilt component illustrated as a tilting angle α. The surface movement can be for example of vibration type. The vibration can be caused by a sound or vibration itself can produce a sound, thus making the motion of the surface of interest associated with the sound. In this specific and non-limiting example, the temporal movements of the object are produced due to acoustic vibrations of the support surface 202 . Due to those vibrations the object is also vibrated. The described configuration includes observation of the secondary speckle pattern that is created by illuminating the object. In order to monitor the object vibration, the correlation of each of the sequential images is measured. By analyzing the temporal changes in the correlation peak position, relative movement of the stimulated object was extracted.
[0039] Imaging is performed by imaging device 204 at two instances: when the diffusive object is at a position and orientation DO 1 and when the diffusive object is at a position and orientation DO 2 , DO 1 and DO 2 defining a certain tilting angle α. The imaging device 204 includes an imaging lens L and a pixel detector array PDA. The imaging device 204 is configured for focusing on a forward displaced plane IF. At both instances, the speckle pattern is formed as a reflection of at least partially coherent light beam LB (e.g. laser beam). With regards to speckle patterns the following should be noted. Speckle patterns are self interfered random patterns having relatively random amplitude and phase distributions. So-called “primary speckle patterns” can be generated by passage of illuminating light through a diffuser or a ground glass. So-called “secondary speckle patterns” can be generated by reflection of illuminating light from the diffuse surface of an object. The relative shift 13 of the speckle pattern is proportional to the change in the spatial position of the speckle pattern due to the object temporal movement:
[0000]
β
=
4
π
tan
α
λ
≈
4
π
α
λ
[0040] where α is the time varying tilting angle of the illuminated surface as shown in FIG. 2 a , λ is the illumination wavelength.
[0041] The temporal movement of the object is proportional to the change in the speckle pattern that is caused by the stimulation field.
[0042] In order to detect a personal authentication, the frequency response of the stimulated object was calculated at the excitation frequencies (main peak) when excited due to the applied stimulation field. The frequency response (raw data) is expressed as:
[0000]
X
(
k
)
=
∑
j
=
1
N
x
(
j
)
e
-
2
π
ijk
/
N
[0043] where x(j) is a temporal vector of the change in the position of the correlation peak vs. time, N is the number of frames that were captured during each sample.
[0044] The following experiments illustrated in FIGS. 3-6 were performed by using the set up of the system described above with reference to FIG. 2 a
[0045] Reference is made to FIGS. 3 a -3 c illustrating the temporal frequency signature of a fingerprint for three different individual persons. In this experiment the full fingerprint was measured for three different persons. Three fingerprints from each person were tested. The results show that each person has a unique temporal frequency signature.
[0046] Reference is made to FIGS. 4 a -4 i illustrating different temporal frequency signatures obtained for segmented image data of different persons for different fingers. In this experiment a segmented fingerprint was measured for five persons. In some embodiments, the method comprises calculating a temporal frequency profile of a plurality of two-dimensional correlation peak positions per the stimulation frequency defining a spatial relationship of temporal frequency signatures for a plurality of two-dimensional spatial regions. To this end, each image data area was divided into a two-dimensional matrix having four two-dimensional spatial regions (sub-area) and was analyzed separately. The analysis comprises for example that the movement profile of the correlation peak in spatial region X (not represented) is the largest at temporal excitation frequencies a and b while in region Y (not represented) the movement profile of the correlation peak is the largest at temporal frequencies of b and a respectively. Three fingerprints from each person were tested (index, middle, ring). For stability test, the measurement was repeated for each finger three times (total of 180 segmented fingerprints samples). The results show that each person and also each finger of a person have a unique temporal frequency signature response. More specifically, FIG. 4 a represents the temporal frequency signature of an index fingerprint for a person #1; FIGS. 4 b -4 d represent the temporal frequency signature of an index, middle and ring fingerprints for a person #2; FIGS. 4 e -4 f represent the temporal frequency signature of an index, and ring fingerprints respectively for a person #3; FIGS. 4 g -4 i represent the temporal frequency signature of an index, middle and ring fingerprints respectively for a person #4. It is clearly shown that each frequency response of different persons and finger is unique.
[0047] Reference is made to FIGS. 5 a -5 g showing stability test results demonstrating that the frequency response of each fingerprint is repetitive and fixed. FIGS. 5 a -5 b illustrate the stability of the technique of the present invention by representing the temporal frequency signature of an index fingerprint of person #1 twice respectively. FIGS. 5 c -5 e illustrate the stability results by representing the temporal frequency signature of an index fingerprint of person #2 three different times respectively. FIGS. 5 f -5 g illustrate the stability results by representing the temporal frequency signature of a middle fingerprint for a person #2 twice respectively. It can be clearly seen from the experiments that a similar temporal frequency signature is obtained when the fingerprint record is repeated.
[0048] FIGS. 6 a -6 f represent the temporal frequency signature of a middle and index fingerprints under dry and wet conditions respectively. More specifically, FIGS. 6 a -6 b represent the temporal frequency signature of an index fingerprint of a person #1 under dry and wet conditions respectively. FIGS. 6 c -6 d represent the temporal frequency signature of a middle fingerprint of a person #2 under dry and wet conditions respectively. FIGS. 6 e -6 f represent the temporal frequency signature of an index fingerprint of a person #2 under dry and wet conditions respectively.
[0000]
TABLE 1
Stability:
Sub-fingerprints:
CV [%]
Dry-Wet:
CV [%]
(3 experiments)
CV [%]
(4 sub-areas)
Person #1: Finger #2
4.70
73.84
5.93
Person #2: Finger #3
3.54
71.15
0.79
Person #2: Finger #4
6.58
71.98
1.59
Person #4: Finger #3
7.05
75.29
9.29
Total (180 samples)
4.72
73.76
3.45
[0049] Table 1 shows the statistic parameters for the measured values of the subjects according to the conclusions mentioned above. | The present invention relates to a method and system for condition authentication based upon temporal-spatial analysis of vibrational responsivity. In particular, the present invention provides temporal tracking of reflected secondary speckle patterns generated when illuminating an object with a source of at least partially coherent beam and while applying a stimulated field at different temporal stimulating frequencies. | 6 |
CROSS-REFERENCE TO RELATED APPLICATIONS
[0001] This application claims priority from and is a continuation of U.S. patent application Ser. No. 14/275,819, “MANAGEMENT OF DIGITAL ASSETS”, Attorney Docket omnetempus.00001.us.n.1, Mauro Marson, filed May 12, 2014, the entire disclosure of which is incorporated by reference herein, in its entirety, for all purposes. U.S. patent application Ser. No. 14/275,819 is co-pending and is related to, and herein incorporates by reference for all purposes the following U.S. patent application: U.S. patent application Ser. No. 14/275,825, “PRESENTATION OF HOMAGE TOKENS”, Attorney Docket omnetempus.00002.us.n.1, Mauro Marson, filed May 12, 2014, the entire disclosure of which is incorporated by reference herein, in its entirety, for all purposes.
BACKGROUND
[0002] The advent of the Internet and cloud storage has created new issues with regards to estate management. Property that was commonly stored in physical format is now increasingly stored and managed digitally in the cloud. In addition to storing digital content in the cloud, many people now maintain some form of an online presence, whether through accounts created on social networking sites or other web services requiring a user to create an account.
[0003] Many different systems and protocols exist for securely accessing digital assets across a variety of different platforms and devices. Unfortunately, these systems are not cross-compatible in their ability to transfer or even view assets associated with a common owner or account. Both the management and access to digital assets can be confusing and difficult for the end-user as authentication and permissions functionality is complex and disparate. Furthermore, the systems for access, storage, and modification of digital assets are changing with time. Many systems are rapidly developing and modifying their protocols and features, while others are sunsetting either partially or entirely. Thus, the maintenance of digital assets is difficult for users.
[0004] Managing the transfer of digital assets between parties can be even more complicated and cumbersome than managing one's own digital assets. Complicating matters, when one party is deceased or incapacitated, situations arise in which assets can be inaccessible or lost entirely. Thus, the transfer of digital assets stored in heterogeneous systems, formats, and protocols presents an increasingly difficult technical problem for system architects and engineers. While the emergence of the Internet and cloud computing have brought numerous improvements and conveniences in the area of information technology, the management and transfer of assets has become increasingly complex.
SUMMARY
[0005] Additional features and advantages of the disclosure will be set forth in the description which follows, and in part will be obvious from the description, or can be learned by practice of the herein disclosed principles. The features and advantages of the disclosure can be realized and obtained by means of the instruments and combinations particularly pointed out in the appended claims. These and other features of the disclosure will become more fully apparent from the following description and appended claims, or can be learned by the practice of the principles set forth herein.
[0006] Disclosed are systems, methods, and non-transitory computer-readable storage media for machine-based management and transfer of digital assets. An asset management system can enable creation and storage of digital assets, which can later be accessed, modified, etc., by one or more authenticated users. The asset management system enables designation of one or more inheriting users to have access to the digital asset(s) in the event that a programmatic trigger condition is satisfied.
[0007] A primary user can provide information identifying one or more inheriting users. In response to input from a primary user, the asset management system can be configured to create one or more programmatic trigger conditions with various inputs which must be satisfied in order for a digital asset transfer to take place. The primary user can also designate specific digital assets that the inheriting user is to inherit in the event that the programmatic trigger condition(s) is/are satisfied. Confirmation from any number of trusted external sources can be required for satisfaction of the programmatic trigger condition.
[0008] The asset management system is configured to define one or more actions to take place upon a determination that the programmatic trigger condition(s) is/are satisfied. For example, permissions associated with the digital asset(s) can be modified to authorize one or more inheriting users to access the digital assets in a manner authorized by the primary user. A variety of other automated actions can be defined by the system to occur in association with execution of the digital asset transfer.
BRIEF DESCRIPTION OF THE DRAWINGS
[0009] Embodiments of the present invention are illustrated by way of example, and not by way of limitation, in the figures of the accompanying drawings and in which like reference numerals refer to similar elements.
[0010] FIG. 1 illustrates an exemplary computer system in accordance with embodiments of the present invention;
[0011] FIG. 2 illustrates an exemplary embodiment of designating an inheriting user to inherit digital assets;
[0012] FIG. 3 illustrates an exemplary embodiment of providing a primary user's digital assets to an inheriting user upon the primary user passing away;
[0013] FIG. 4 illustrates an exemplary embodiment of presenting an homage token on a memorial;
[0014] FIGS. 5A and 5B illustrate an exemplary embodiment of a memorial for a deceased user;
[0015] FIG. 6 illustrates an exemplary embodiment of an interface for managing a user account on an asset management system; and
[0016] FIGS. 7A and 7B illustrate exemplary possible system embodiments.
DETAILED DESCRIPTION
[0017] Various embodiments of the disclosure are discussed in detail below. While specific implementations are discussed, it should be understood that this is done for illustration purposes only. A person skilled in the relevant art will recognize that other components and configurations may be used without parting from the spirit and scope of the disclosure.
[0018] The disclosed technology addresses the need in the art for management of digital assets. An asset management system can enable a primary user to create a user account and store digital assets, which can later be accessed, modified, etc., by the primary user. The asset management system can also enable the primary user to designate one or more inheriting users that will be authorized to access the digital assets in the event that the primary user passes away.
[0019] The primary user can provide contact information identifying the inheriting users. For example, the primary user can provide contact information such as an e-mail address, or, alternatively, an account identifier associated with the inheriting user's account with the asset management system. The primary user can also designate specific digital assets that the inheriting user is to inherit in the event that the primary user passes away.
[0020] Upon a determination that the primary user has passed away, the asset management system can authorize each inheriting user to access the digital assets designated to the inheriting user by the primary user. In some embodiments, the digital assets can be assigned to the inheriting user's account, and accordingly, they can be accessed by the inheriting user. For example, permissions attributes of the digital assets can be modified such that the digital assets are accessible by the inheriting user. In another example, the inheriting user's login credentials can be authorized to access the primary user's account, and thereby access the digital assets. Alternatively, in some embodiments, the inheriting user can be provided with login credentials to access the primary user's account.
[0021] Further, the asset management system can also enable creation of a memorial to a deceased individual. For example, a primary user can create their own memorial, which can be published upon the primary user passing away. Alternatively, an inheriting user can create a memorial for the primary user, which can be published when the primary user passes away.
[0022] Users can post to the memorial to show respect or homage to the deceased individual. For example, users can post homage tokens, such as digital candles, digital flowers, etc., to the memorial where they can be viewed by other users viewing the memorial. In some embodiments, the posted homage tokens can be associated with an expiration time, after which the posted homage token can be removed from the memorial.
[0023] FIG. 1 illustrates an exemplary system configuration 100 , wherein electronic devices communicate via a network for purposes of exchanging content and other data. As illustrated, multiple computing devices can be connected to a communication network 104 and be configured to communicate with each other through the use of the communication network 104 .
[0024] A communication network 104 can be any type of network, including a local area network (“LAN”), such as an intranet, a wide area network (“WAN”), such as the internet, or any combination thereof. Further, a communication network 104 can be a public network, a private network, or a combination thereof. A communication network 104 can also be implemented using any number of communications links associated with one or more service providers, including one or more wired communication links, one or more wireless communication links, or any combination thereof. Additionally, a communication network 104 can be configured to support the transmission of data formatted using any number of protocols.
[0025] Multiple computing devices can be connected to a communication network 104 . A computing device can be any type of general computing device capable of network communication with other computing devices. For example, a computing device can be a personal computing device such as a desktop or workstation, a business server, or a portable computing device, such as a laptop, smart phone, or a tablet PC. A computing device can include some or all of the features, components, and peripherals of computing device 7 of FIGS. 7A and 7B .
[0026] To facilitate communication with other computing devices, a computing device can also include a communication interface configured to receive a communication, such as a request, data, etc., from another computing device in network communication with the computing device and pass the communication along to an appropriate module running on the computing device. The communication interface can also be configured to send a communication to another computing device in network communication with the computing device.
[0027] As illustrated, the system 100 includes client devices 102 1 . . . 102 n (collectively “ 102 ”) and an asset management system 110 , connected to a communication network 104 to communicate with each other to transmit and receive data. The asset management system 110 can be configured to manage digital assets for user accounts. This can include storing digital assets and enabling a user to access the digital assets.
[0028] A user can interact with the asset management system 110 through the client devices 102 connected to the network 104 by direct and/or indirect communication. The asset management system 110 can support connections from a variety of different client devices 102 , such as desktop computers; mobile computers; mobile communications devices, e.g. mobile phones, smart phones, tablets; smart televisions; set-top boxes; and/or any other network enabled computing devices. The client devices 102 can be of varying type, capabilities, operating systems, etc. Furthermore, the asset management system 110 can concurrently accept connections from and interact with multiple client devices 102 .
[0029] A user can interact with the asset management system 110 via a client-side application installed on a client device 102 i . In some embodiments, the client-side application can include an asset management system-specific component. For example, the component can be a stand-alone application, one or more application plug-ins, and/or a browser extension. However, the user can also interact with the asset management system 110 via a third-party application, such as a web browser, that resides on a client device 102 i and is configured to communicate with the asset management system 110 . In either case, the client-side application can present a user interface (UI) for the user to interact with the asset management system 110 . For example, the user can interact with the asset management system 110 via a client-side application integrated with the file system or via a webpage displayed using a web browser application.
[0030] The asset management system 110 includes functionality to allow a user to store digital assets on the asset management system 110 , as well as perform a variety of digital asset management tasks, such as retrieve, modify, browse, and/or share the digital assets. Furthermore, the asset management system 110 includes functionality to allow a user to access the digital assets from multiple client devices 102 . For example, a client device 102 i can upload digital assets to the asset management system 110 via the communication network 104 . The digital assets can later be retrieved from the asset management system 110 using the same client device 102 or some other client device 102 j .
[0031] To facilitate the various digital asset management services, a user can create a user account with the asset management system 110 . The account information can be maintained in a user account database 150 . The user account database 150 can store account information for registered users. In some cases, the only personal information in the user account can be a username and/or email address. However, asset management system 110 can also be configured to accept additional user information.
[0032] The user account database 150 can also include account management information, such as user account type, e.g. free or paid; usage information, e.g. file edit history; maximum storage space authorized; storage space used; digital asset storage locations; security settings; personal configuration settings; digital asset sharing data; etc. The account management module 124 can be configured to update and/or obtain user account details in the user account database 150 . The account management module 124 can be configured to interact with any number of other modules in the asset management system 110 .
[0033] A user account can be used to store digital assets from one or more the client devices 102 authorized on the user account. Digital assets can be stored in the digital asset storage 160 . The digital assets can include but are not limited to digital data, documents (e.g., legal documents such as wills, trust agreements, etc.), text files, image files, audio files, video files, digital currency, etc. The digital assets can also include folders of various types with different behaviors, or other mechanisms of grouping digital assets together. For example, a user account can include a public folder that is accessible to any user. The public folder can be assigned a web-accessible address. A link to the web-accessible address can be used to access the contents of the public folder. In another example, an account can include a photos folder that is intended for photos and that provides specific attributes and actions tailored for photos (e.g., a web album interface to provide the photos for public viewing); an audio folder that provides the ability to play back audio files and perform other audio related actions; or other special purpose folders. A user account can also include shared folders or group folders that are linked with and available to multiple user accounts. The permissions for multiple users may be different for a shared folder.
[0034] In some embodiments, digital assets for the primary user, but not uploaded directly by the primary user, can be stored in the digital asset storage 160 . For example, the asset management system 110 can request information from the primary user and store information provided by the primary user in a digital asset. In a more specific example, the asset management system 110 may present the primary user with a questionnaire asking about confidential information of the primary user related to external accounts (e.g., username and password for a stock trading website or an online banking website), files (e.g., passwords to password-protected files on a computer device of the primary user), or otherwise (e.g., bank account information or the combination on a padlock), and store answers to the questions in a digital asset created by the asset management system 110 in response to the questionnaire. The digital asset may be a proprietary file format dedicated to storing such confidential information. In other embodiments, the information gathered directly from the primary user or indirectly from the primary user (e.g., through sources related to the primary user), may be stored in other formats (e.g., in a relational database).
[0035] The digital asset storage 160 can be a storage device, multiple storage devices, or a server. Alternatively, the digital asset storage 160 can be a cloud storage provider or network storage accessible via one or more communications networks. The asset management system 110 can hide the complexity and details from the client devices 102 so that information identifying exactly where the digital assets are being stored by asset management system 110 is not shared with the client device 102 . In one variation, the asset management system 110 can store the digital assets in the same folder hierarchy as they appear on a client device 102 i . However, the asset management system 110 can store the digital assets in a different order, arrangement, or hierarchy. The asset management system 110 can store the digital assets in a network accessible storage (SAN) device, in a redundant array of inexpensive disks (RAID), etc. Digital asset storage 160 can store digital assets using one or more partition types, such as FAT, FAT32, NTFS, EXT2, EXT3, EXT4, ReiserFS, BTRFS, and so forth.
[0036] The digital asset storage 160 can also store metadata describing digital assets, digital asset types, and the relationship of digital assets to various user accounts, folders, or groups. The metadata for a digital asset can be stored as part of the digital asset or can be stored separately. In one variation, each digital asset stored in the digital asset storage 160 can be assigned a system-wide unique identifier.
[0037] In some embodiments, the asset management system 110 can be configured to encrypt the digital assets stored in a user account. Adding encryption to the digital assets can provide an additional layer or protection and security for the digital assets. Further, in some embodiments, the asset management system 110 can be configured to back up the digital assets. For example, the digital assets can be backed up to remote file servers, disk, etc. In some embodiments, a user can select whether to include encryption and/or backup capability to their user account. For example, a user can pay a specified fee to upgrade their user account to add encryption and/or backup capability.
[0038] In some embodiments, the asset management system 110 can be configured to manage the digital asset in a user account in the event that the primary user associated with the user account passes away. For example, the asset management system 110 can be configured to determine that the primary user has passed away and authorize the appropriate inheriting users to access the digital assets. A primary user can be the user that created the user account and has authorization to access the user account.
[0039] In some embodiments, the asset management system 110 can be configured to enable a primary user to select one or more inheriting users that, in the event that the primary user passes away, can inherit the primary user's digital assets, meaning that the digital assets will become the property of the inheriting user. Initially, the primary user will be the only user authorized to access the digital assets in the primary user's account on the asset management system 110 . Upon confirmation of the primary user's death, the inheriting users can be authorized to access the primary user's digital assets stored on the asset management system 110 , thus transferring ownership of the digital assets to the inheriting users.
[0040] To accomplish this, the asset management system 110 can include an inheritance module 115 configured to enable a user to assign one or more inheriting users to inherit the primary user's digital assets. For example, the inheritance module 115 can be configured to prompt a primary user to enter information identifying one or more inheriting users.
[0041] In some embodiments, the inheritance module 115 can be configured to prompt a primary user to enter contact information for an inheriting user. For example, a primary user can enter an e-mail address, phone number, etc., for an inheriting user. Alternatively, in some embodiments, the inheritance module 115 can be configured to prompt a user to enter user account information for an inheriting user. For instance, an inheriting user may have an existing account with the asset management system 110 , and the inheritance module 115 can prompt the primary user to enter account information identifying the user account of the inheriting user, such as an account number, user name, etc.
[0042] In some embodiments, the inheritance module 115 can determine if an inheriting user has an existing user account with the asset management system 110 . For example, the inheritance module 115 can prompt a primary user to enter contact information identifying an inheriting user, and the inheritance module 115 can use this information to determine if there is an existing user account associated with the received contact information. To accomplish this, the inheritance module 115 can search the user account data in the user account database 150 to determine if an existing user account includes contact information matching the contact information provided by the primary user.
[0043] In some embodiments, the inheritance module 115 can be configured to notify an inheriting user that they have been designated as an inheriting user for the primary user's user account. For example, the inheritance module 115 can use contact information, such as an e-mail address, provided by the primary user to contact the inheriting user at the provided e-mail address. Alternatively, if a primary user provided data identifying the inheriting user's account with the asset management system 110 , the inheritance module 115 can gather the inheriting user's contact information from the user profile and contact the inheriting user.
[0044] In some embodiments, the inheritance module 115 can notify the inheriting user that the inheriting user has been designated as an inheriting user by the primary user. For example, the inheritance module 115 can send the inheriting user a message notifying the inheriting user that the primary user has designated the inheriting user to inherit digital assets of the primary user in the event that the primary user passes away.
[0045] In some embodiments, the inheritance module 115 can further prompt the inheriting user to create a user account with asset management system 110 . For instance, the asset management system 110 can be configured to require that an inheriting user have a user account with the asset management module 110 to inherit the primary user's digital assets in the event that the primary user passes away. The inheritance module 110 can transmit the inheriting user a message prompting the inheriting user to create a user account.
[0046] In some embodiments, the inheritance module 115 can prompt the inheriting user to create a standard user account such that the inheriting user is the primary user of the newly created user account. Alternatively, in some embodiments, the inheritance module 115 can prompt the inheriting user to create an inheriting user account with limited functionality that enables the inheriting user to inherit the primary user's digital assets, but does not include the other functionality of a standard user account, such as storing digital assets, designating inheriting users, etc., although the inheriting user can choose to create a standard user account if desired.
[0047] In some embodiments, the inheritance module 115 can require an inheriting user to acknowledge or accept being an inheriting user for a primary user's account. For example, the inheritance module 115 can require an inheriting user to read the terms of agreement and acknowledge acceptance of the presented terms as well as the responsibilities associated with being an inheriting user for the primary user's account. Further, the inheritance module 115 can enable an inheriting user to decline the primary user's designation as an inheriting user. For example, the inheritance module 115 can present the user with a user interface element, such as a button, that when selected, indicates that the inheriting user decline the invitation to be an inheriting user for the primary user's account.
[0048] If an inheriting user does decline the invitation to be an inheriting user for the primary user's account, the inheritance module 115 can be configured to notify the primary user of the inheriting user's decision. For example, the inheritance module 115 can transmit a notification to the primary user notifying the primary user of the inheriting user's decision to decline. The inheritance module 115 can further prompt the primary user to identify a substitute inheriting user.
[0049] The inheritance module 115 can store information regarding a designated inheriting user and associate the information with the primary user's account. For example, the inheritance module 115 can store the inheriting user's contact information in the user account database 150 and associate the contact information with the primary user's account. Alternative, the inheritance module 115 can store the inheriting user's information in the inheriting user's account in the user account database 150 and associate the inheriting user's account with the primary user's account. For example, the inheritance module 115 can store an account identifier identifying the inheriting user's account in the primary user's account in the user account database 150 .
[0050] Designating an inheriting user can result in the inheriting user being provided authorization to access the primary user's digital assets on the asset management system 110 in the event that the primary user passes away. For example, in some embodiments, the inheritance module 115 can transmit the inheriting user log in credentials to access the primary user's account upon the primary user passing away. Alternatively, in some embodiments, the inheritance module 115 can authorize an inheriting user's account to access the primary user's digital assets upon the primary user passing away. An inheriting user can thus use their login credential to login to their user account, where they can access the primary user's digital assets.
[0051] The inheritance module 115 can determine whether a primary user has passed away in numerous ways. For example, in some embodiments, the inheritance module 115 can enable a primary user to designate one or more trusted users that are trusted to notify the asset management system 110 that the primary user has passed away. For example, a primary user can designate a person that the primary user trusts, such as an attorney, friend, family member, etc., as a trusted person that is authorized to notify the asset management system 110 that the primary user has passed away, thus triggering the inheritance module 115 to provide an inheriting user access to the primary user's digital assets.
[0052] In some embodiments, the inheritance module 115 can enable a primary user to select any user to be a trusted user without restriction. Alternatively, in some embodiments, the inheritance module 115 can restrict the primary user to select a trusted user that is not an inheriting user for the primary user's account. A conflict of interest can arise if an inheriting user is also a trusted user because the inheriting user can cause the transfer of the primary user's digital assets to his/herself. To avoid this potential conflict of interest, the inheritance module 115 can restrict the users that are eligible to be designated as a trusted user to users that are not inheriting users.
[0053] To designate a trusted user, in some embodiments, the inheritance module 115 can require the primary user to enter contact information for the trusted user. For example, the inheritance module 115 can require the primary user to provide an e-mail address, phone number, address, etc., for the trusted user. Alternatively, in some embodiments, the inheritance module 115 can prompt a user to enter account information for the trusted user. For example, the primary user can designate a trusted user that has an existing account with the asset management system 110 by entering account information identifying the trusted user's account, such as an account identifier and/or username.
[0054] In some embodiments, the inheritance module 115 can contact a trusted user to notify the trusted user that they have been designated as a trusted user for the primary user's account. For example, the inheritance module 115 can transmit a notification message to the trusted user using the contact information provided by the primary user, or, alternatively, know contact information for the trusted user gathered from the trusted user's account.
[0055] In some embodiments, the inheritance module 115 can enable a trusted user to agree or decline to be a trusted user for the primary user's account. For example, the inheritance module 115 can provide the trusted user with a user interface element, such as a button, that when selected, indicates that the trusted user declined to be a trusted user for the primary user's account. Likewise, the inheritance module 115 can provide the trusted user with a user interface element that, when selected, indicates that the trusted user accepts the responsibility of being a trusted user for the primary user's account. This can include requiring the trusted user to read and accept terms and conditions associated with being a trusted user.
[0056] A trusted user can be trusted to notify the asset management system 110 that a primary user has passed away, thus causing the primary user's digital assets to be transferred to the inheriting users. In some embodiments, the inheritance module 110 can require a trusted user to notify the asset management system 110 that a primary user has passed away using a designated contact method. For example, the trusted user can be required to transmit a message from an e-mail address provided by the primary user for the trusted user. Alternatively, the trusted user can be required to make a phone call from a specified phone number, such as a number provided by the primary user.
[0057] In some embodiments, the trusted user can be required to transmit a message from their user account with the asset management system 110 . For example, the inheritance module 115 can require that a trusted user have a valid account with the asset management system 110 to be designated as a trusted user. The inheritance module 115 can enable a user to indicate that a primary user has passed away from their user account. For example, upon logging into their user account, a trusted user can be presented with a user interface element that, when selected, indicates that a primary user has passed away. Alternatively, in some embodiments, the inheritance module 115 can enable a trusted user to transmit a message from their user account indicating that the primary user has passed away. The message can be sent to an administrator of the asset management system 110 .
[0058] In some embodiments, the inheritance module 115 can determine that a primary user has passed away by receiving one or more trusted documents. A trusted document can be a document predetermined to be trusted to indicate that the primary user has passed away. For example, a trusted document can be an official copy of a death certificate. Upon receiving the death certificate, the inheritance module 115 can determine that the primary user has passed away.
[0059] Alternatively, in some embodiments, the trusted document can be an affidavit indicating that the primary user has passed away. For example, the affidavit can be received from an inheriting user, trusted user, other family member, government official, etc. In some embodiments, the inheritance module 115 can require that the trusted document, such as an affidavit, be received from or be executed by a specified person or a person from a group of specified people, to be accepted as a valid confirmation that the primary user has passed away.
[0060] In some embodiments, the inheritance module 115 can require multiple forms of confirmation that a primary user has passed away. For example, a trusted user can be required to confirm that a primary user has passed away using two or more of the contact methods described above. For example, a trusted user can be required to login to their user account on the asset management system 110 to indicate that a primary user has passed away. The inheritance module 115 can then require the trusted user to confirm that the primary user has passed away using one or more of the contact methods provided for the user. For example, the inheritance module 115 can send a confirmation message to the trusted user via an e-mail address or phone number of the trusted user. The confirmation message can require the trusted user to confirm that the primary user has passed away, for example, by responding to the confirmation message, providing a specified input, etc.
[0061] In some embodiments, the inheritance module 115 can require confirmation from multiple trusted users that a primary user has passed away. For example, the inheritance module 115 can require a primary user to designate two or more and trusted users and multiple users must notify the asset management system 110 that a primary user has passed away for the inheritance module 115 to determine that the primary user has passed away, causing the primary user's digital assets to be passed to the inheriting users.
[0062] In some embodiments, the inheritance module 115 can determine that a primary user has passed away based on information provided from a third party service/source. For example, a third party trusted service can confirm that a primary user has passed away and transmit a message to the asset management system 110 indicating that the primary user has passed away. In some embodiments, the third party service can notify the asset management system 110 when a primary user has passed away. In some embodiment, the asset management system 110 can query the third party service regarding whether a specified primary user has passed away. For example, the inheritance module 115 can be configured to periodically query the third party service regarding the status of one or more primary users.
[0063] Alternatively, the inheritance module 115 can query the third party service upon a specified trigger occurring. For example, the inheritance module 115 can query the third party service after receiving a notification that a primary user has passed away, such as a notice received from a trusted user. Alternatively, the inheritance module 115 can query the third party service upon a determination that a primary user has not logged into their user account for a specified amount of time. For example, the inheritance module 115 can query the third party service regarding the status of the primary user if the primary user has not logged into their user account in six months, a year, etc.
[0064] In some embodiments, the inheritance module 115 can transmit proof of life messages to a primary user requesting confirmation from the primary user that the primary user has not passed away. For example, the inheritance module 115 can transmit a proof of life message to the primary user every six months, year, etc. If a primary user does not respond to the proof of life message confirming that the primary user is still alive, the inheritance module 115 can determine that the user has passed away or, alternatively, initiate a secondary query regarding the status of the primary user. For example, the inheritance module 115 can query a third party service or a trusted user regarding the status of the primary user.
[0065] Upon a determination that the primary user has passed away, the inheritance module 115 can be configured to transfer the primary user's digital assets to an inheriting user. For example, in some embodiments, the inheritance module 115 can reassign the digital assets from the primary user's account to the inheriting user's account. Alternatively, in some embodiments, the inheritance module 115 can enable the inheriting user's account to access the contents of the primary user's account. In some embodiments, the inheritance module 115 can send a message to the inheriting user that includes login credentials enabling the inheriting user to login to the primary user's account and access the digital assets.
[0066] In some embodiments, the inheritance module 115 can transfer all of the primary user's digital assets to one or more inheriting users. Alternatively, in some embodiments, the inheritance module 115 can enable a primary user to select the digital assets that are transferred to each inheriting user. For example, a primary user may wish to disperse some digital assets to one inheriting user and some other digital assets to other inheriting users.
[0067] To accomplish this, the inheritance module 115 can be configured to enable a primary user to designate the inheriting user that will receive a digital asset upon the primary user's death. The inheritance module 115 can maintain a record of the inheriting user assigned to each digital asset. For example, in some embodiments, the inheritance module 115 can maintain an inheritance index that lists each digital asset along with the inheriting user that will receive the digital asset upon the primary user's death. Alternatively, in some embodiments, the inheritance module 115 can attach metadata to a digital asset that identifies the inheriting user designated to receive the digital asset.
[0068] In some embodiments, the inheritance module 115 can be configured to enable a primary user to create a directory that is designated to a specified inheriting user. For example, a primary user can create a multiple directories and assign each directory to a different inheriting user. The primary user can then place digital assets into the various directories to assign the digital asset to a selected inheriting user. Upon confirmation that the primary user has passed away, the inheritance module 115 can authorize an inheriting user to access all of the digital assets in the directory assigned to the inheriting user.
[0069] In addition to managing digital assets upon a primary user's death, in some embodiments, the asset management system 110 can be configured to provide an online memorial for a primary user. For example, digital assets, such as files, images, audio, etc., can be stored in a public folder in the primary user's account to create a memorial for the primary user that can be publicly accessed.
[0070] In some embodiments, the asset management system 110 can include a memorial module 120 configured to create a memorial for a primary user. The memorial module 120 can provide tools and templates for creating a memorial for a primary user. For example, the memorial module 120 can provide a memorial creation interface enabling a user to create and customize a memorial. In some embodiments, the memorial creation interface can enable a user to select available memorial templates and customize the selected memorial template by entering text, images, etc.
[0071] In some embodiments, the memorial creation interface can enable a user to select images, audio, video, etc., stored in the primary user's account to include in the memorial. Alternatively, the memorial creation interface can enable a user to upload images, audio, video, etc., from the user's client device to include in the memorial.
[0072] In some embodiments, the memorial module 120 can enable a primary user to create their own memorial, which will not be published until the primary user has passed away. For example, a primary user can use the memorial creation interface to create a memorial that will remain private at least until asset management system 110 determines that the primary user has passed away.
[0073] In some embodiments, the memorial module 120 can be configured to publish the primary user's memorial upon a determination that the primary user has passed away. Alternatively, in some embodiments, the memorial module 120 can require that an inheriting user select or recommend to an inheriting user to select to publish the memorial upon after the death of the primary user. This type of embodiment allows an inheriting user to complete the memorial prior to the memorial being published and made publicly available.
[0074] Alternatively, a user other than the primary user can also create and publish a memorial for the primary user. For example, an inheriting user can create a memorial for the primary user after the primary user passes away. In some embodiments, the primary user can designate the inheriting user that can be granted authorization to create and publish a memorial for the primary user.
[0075] In some embodiments, an inheriting user can create a memorial for the primary user prior to the primary user passing away. For example, an inheriting user can login to their user account and create a memorial for the primary user with the memorial creation interface. While the inheriting user can create a memorial for a primary user prior to the primary user passing away, in some embodiments, the memorial module 120 can be configured to restrict the inheriting user from publishing the memorial until it is determined that the primary user has passed away.
[0076] In some embodiments, the asset management system 110 can be configured to enable users to post messages, images, audio, etc., to a primary user's memorial after the memorial has been published and made publicly available. For example, friends of the primary user may wish to post comments, images, etc., to show respect or homage to the passing of their friend. Memorial comments, images, etc., posted to the primary user's memorial can be presented along with the memorial and made publicly available to other users that view the memorial.
[0077] In some embodiments, the memorial module 120 can be configured to enable users to post an homage token to a published memorial. An homage token can be a token posted to show respect or homage to a primary user that has passed away. In some embodiments, an homage token can be an icon or image of an item that is commonly left at a live memorial, such as a candle, flower, picture, etc. An homage token posted to a published memorial can be presented on the memorial and viewed by other users viewing the memorial. For example, an homage token depicting a candle can be presented on the primary user's memorial.
[0078] In some embodiments, the memorial module 120 can be configured to remove an homage token posted to a memorial after a predetermined amount of time passing after the homage token has been posted. For example, an homage token can have an expiration time based on the time the homage token is posted to a memorial, such as one hour, one day, one week, etc., after the homage token is posted, after which the homage token is removed from the memorial. The memorial module 120 can be configured to track the amount of time that has elapsed after an homage token has been posted to a memorial and determined that an homage token has expired when the predetermined amount of time has elapsed after the homage token was posted to the memorial. Upon a determination that an homage token has expired (e.g., the predetermined amount of time has elapsed after the homage token was posted to the memorial), the memorial module 120 can remove the homage token from the memorial such that the homage token is no longer visible to users viewing the memorial.
[0079] In some embodiments, the expiration time associated with an homage token (e.g., the predetermined amount of time that must elapse after the homage token is posted to a memorial for the homage token to expire) can be variable. For example, the expiration time associated with an homage token can be based on the type of object depicted by the homage token. For example, an homage token depicting a candle can be associated with a different expiration time than an homage token depicting flowers.
[0080] In some embodiments, the expiration time can be based on the expected life of the object depicted by the homage token. For example the expiration time associated with a candle can be based on a time that a real candle would last before burning out. Likewise, the expiration time associated with an homage token depicting flowers can be based on a time that real flowers would last before wilting.
[0081] In some embodiments, the expiration time associated with an homage token can be based on the depicted size of the homage token. For example, the expiration time associated with an homage token depicting a large candle can be longer than the expiration time associated with an homage token depicting a smaller candle.
[0082] In some embodiments, the expiration time associated with an homage token can be based on an amount of money paid by a user to post the homage token to a memorial. The memorial module 120 can require a user to pay a predetermined amount of money to post an homage token, or alternatively, to post a ‘premium’ homage token to a memorial. The expiration time associated with an homage token can be based on the amount of money paid by a user to post the homage token such that the more money that a user pays to post an homage token, the longer the expiration time associated with the homage token. In some embodiments, a user can renew the homage token before or after it reaches its expiration time, such that the homage token will continue to exist on the memorial until it reaches a second expiration time later than the original expiration time. Users may renew the homage token manually (e.g., after receiving an expiration notification) or set up an auto-renewal mechanism. Further, in some embodiments, a user can pay a specified amount to remove the expiration restriction from the homage token completely, and as a result the posted homage token may never expire.
[0083] In some embodiments, payment made toward an homage token or options of an homage token can be based on advertisements. For example, instead of receiving a monetary amount from a user for an homage token, the user can be required to watch one or more advertisements. Alternatively, a user can post an homage token that includes an advertisement. For example, to post an homage token representing flowers, the memorial module 120 can require the user to allow an homage token to include an advertisement for a flower service. For example, the homage token can include a link to the flower service's website. Alternatively, the homage token can display a logo or other indicator for the flower service.
[0084] In some embodiments, the size of the object depicted by an homage token and/or the type of object represented by an homage token can be based on the amount of money that a user pays to post the homage token to a memorial. For example, the more money the user pays, the larger the object depicted by the homage token, which can be associated with a longer expiration time than a smaller homage token. Likewise, in some embodiments, homage tokens can be based with varying costs based on the object depicted by the homage token. For example, homage tokens depicting flowers can be associated with a higher cost to post to a memorial than the cost to post an homage token depicting a candle.
[0085] In some embodiments, the memorial module 120 can be configured to modify the appearance of an homage token to indicate how much time remains until the homage token expires. For example, the memorial module 120 can indicate that an homage token depicting a candle is nearing its expiration time by modifying the appearance of the homage token to depict the candle becoming shorter and thus closer to burning out. Likewise, the memorial module 120 can indicate that an homage token depicting flowers is nearing its expiration time by modifying the appearance of the homage token to depict that the flowers are wilting.
[0086] In some embodiments, the memorial module 120 can modify the size of the homage token based on the expiration time of the homage token. For example, the homage token can represent an image such as a candle and the memorial module 120 can modify the size of the candle depicted by the homage token to appear as if the candle is burning down. In another example, the memorial module 120 can modify the size of the image of the homage token such that the image decreases in size until it disappears when the homage token expires.
[0087] In some embodiments, the memorial module 120 can be configured to provide a selection of ‘premium’ homage tokens that are only available for purchase. For example, the premium homage tokens can depict specified images, objects, etc., that are considered of higher value and hence are worth an additional cost to be posted. In some embodiments, premium homage tokens can include an animation, video, or other advanced feature, whereas free homage tokens can be limited to static images.
[0088] In some embodiments, a premium homage token can be customizable, whereas free homage tokens are not customized. For example, a premium homage token can include functionality enabling a user to customize a text portion, image, audio, etc. of the premium homage token. Although characteristics such as expiration times, appearance modifications, customizations, etc., have been used to differentiate a premium homage token from a free homage token, these are just examples and are not meant to be limiting. One skilled in the art would recognize that an homage token can be designed to provide any type of additional functionality or improved characteristic over a free homage token and this disclosure appreciates all such embodiments.
[0089] FIG. 2 illustrates an exemplary embodiment of designating an inheriting user to inherit digital assets. Although specific steps are show in FIG. 2 , in other embodiments the method can have more steps, less steps, and/or steps in a different order. As shown, the method begins at block 205 where a new user account on an asset management system is created. A user account on the asset management system can be an account that enables a primary user of the user account to store and manage digital assets. For example, the primary user can access the asset management system using login credentials associated with the primary account, and upload, download, access, edit, etc., digital media assets.
[0090] The method then continues to block 210 where the primary user is prompted to designate an inheriting user to inherit one or more of the digital assets stored in the primary user's account. In some embodiments, the primary user can be prompted to enter contact information for the inheriting user. In some embodiments, the primary user can be prompted to enter account information identifying the inheriting user's account with the asset management system. For example, the primary user can be prompted to enter an account identifier, username, etc., that identifies the inheriting user's account.
[0091] The method then continues to block 215 where the data identifying an inheriting user is received. Upon receiving the data identifying the inheriting user, the method continues to block 220 where the identified inheriting user is notified that they have been designated as an inheriting user for the primary user's account. For example, the inheriting user can be contacted using the contact information for the inheriting user provided by the primary user. The notification can notify the inheriting user that the inheriting user has been designated to inherit one or more digital assets of the primary user's account. Further, the notification can query the inheriting user regarding whether the inheriting user would like to be designated as an inheriting user for the primary user's account.
[0092] The method then continues to block 225 where it is determined whether the inheriting user accepted designation as an inheriting user for the primary user's account. If at block 225 it is determined that the inheriting user declined being designated as an inheriting user for the primary user's account, the method returns to block 210 where the primary user is prompted to enter data identifying an inheriting user.
[0093] Alternatively, if at block 225 it is determined that the primary user accepts to being an inheriting user for the primary user's account, the method continues to block 230 where the inheriting user is designated as an inheriting user for the primary user's account. The method may then end.
[0094] FIG. 3 illustrates an exemplary embodiment of providing a primary user's digital assets to an inheriting user upon the primary user passing away. Although specific steps are show in FIG. 3 , in other embodiments the method can have more steps, less steps, and/or steps in a different order. As show, the method begins at block 305 where a notification is received that the primary user of a user account has passed away.
[0095] In some embodiments, the notification can be received from a trusted user. A trusted user can be a user designated by the primary user as trusted to notify the asset management system when the primary user has passed away. For example, a primary user can designate an attorney as a trusted user.
[0096] In some embodiments, the notification can be received from a trusted third party service. For example, a trusted third party service can be periodically queried regarding whether the primary user has passed away. If the primary user has passed away, the third party service can transmit the notification that the primary user has passed away. Alternatively, in some embodiments, the third party service can transmit the notification that the primary user has passed away without being queried regarding the status of the primary user.
[0097] Upon receiving the notification that the primary user has passed away, the method continues to block 310 where it is determined whether the primary user has passed away. In some embodiments, the notification received can be sufficient to determine that the primary user has passed away, however further authentication measures can also be taken to determine whether the primary user has passed away.
[0098] In some embodiments, a confirmation message can be sent to determine whether the primary user has passed away. For instance, a confirmation message can be sent to a trusted user or a trusted third party service. If a confirmation that the primary user has passed away is returned in response to the confirmation message, it can be determined that the primary user has passed away.
[0099] In some embodiments, a proof of life message can be sent to the primary user. For example, a proof of life message can be sent using one or more known contact methods for reaching the primary user. The proof of life message can request that the primary user respond confirming that the primary user is alive. If a response is not received within a predetermined amount of time after transmitting the proof of life message, it can be determined that the primary user has passed away.
[0100] If at block 310 it is determined that the primary user has not passed away. The method ends. Alternatively, if it is determined that the primary user has passed away, the method continues to block 315 where an inheriting user is authorized to access digital contents of the primary user.
[0101] In some embodiments, a message including login credentials to access the primary user's account can be transmitted to the inheriting user. The inheriting user can then use the received login credentials to login to the primary user's account and access the primary user's digital assets.
[0102] Alternatively, in some embodiments, the primary user's digital assets can be assigned to the inheriting user's account. The inheriting user can then access the digital assets from the inheriting user's account. In some embodiments, the inheriting user's login credentials can be authorized to access the primary user's account. The inheriting user can then user their login credentials to login to the primary user's account and access the digital assets. The method may then end.
[0103] FIG. 4 illustrates an exemplary embodiment of presenting an homage token on a memorial. Although specific steps are show in FIG. 4 , in other embodiments the method can have more steps, less steps, and/or steps in a different order. As shown, the method begins at block 405 where an homage token is presented on a memorial. A user can select to post an homage token on a memorial as a sign of respect or homage for the deceased individual. The posted homage token can be presented on the memorial where it can be viewed by other users viewing the memorial.
[0104] Upon presenting the homage token on the memorial, the method continues to block 410 where it is determined whether the homage token has expired. An homage token can be associated with an expiration time indicating an amount of time that the homage token remains valid, after which the homage token is removed from the memorial. If at block 410 it is determined that the homage token has expired (e.g., a predetermined amount of time has elapsed since the homage token was posted to the memorial), the method continues to block 415 where the homage token is removed from the memorial. The method may then end.
[0105] FIG. 5A illustrates an exemplary embodiment of a memorial for a deceased user. As shown, a memorial 500 can include an image of a deceased user 505 as a central focus of the memorial. The memorial 500 can further include a biography section 510 that includes additional information about the deceased user 505 . For example, the biography section 510 can included the deceased user's name, birthdate, date of death, a biography about the deceased user, etc.
[0106] The memorial 500 can also include a testimonial section 515 , where users can post testimonial messages regarding the deceased user 505 . In addition to testimonials, users can also post homage tokens for the deceased user 505 . As shown, a user can post an homage token to an homage token section 520 located at the bottom of the memorial 500 . An homage token can include an image of an item or action such as a candle, flower, prayer, etc., that a person would place or perform at a memorial to pay homage to the deceased individual.
[0107] In some embodiments, the memorial 500 can include a premium homage token section 525 , where a user can post a premium homage token. For example, a user can pay a fee to post a premium homage token to the premium homage token section 525 , where the posted homage token can be presented prominently rather than at the bottom of the memorial 500 .
[0108] FIG. 5B illustrates the memorial 500 after homage tokens have been posted to the premium homage token section 525 . As shown, three homage tokens 530 , 535 , and 540 have been posted to the premium homage token section 525 . The premium homage tokens can be displayed prominently near the image of the deceased user 505 , rather than at the bottom of the memorial.
[0109] Further, a premium homage token can include multimedia content (audio, video, image, etc.) that can be displayed or played back for other users viewing the memorial 500 . For example, the premium homage token 530 includes an icon representing that the homage token 530 includes an audio recording. A user viewing the memorial 500 can select the homage token 530 to play back the recorded audio.
[0110] An homage token can also include data identifying the user that posted the homage token as well as other data such as the date and time that the homage token was posted. For example, the homage token 535 includes data indicating that the homage token 535 was posted at 9 : 45 by user “Mauro M” and the homage token 540 includes data indicating that the homage token 540 was posted at 10 : 03 by an anonymous user.
[0111] FIG. 6 illustrates an exemplary embodiment of an asset management interface. As shown, a user can be presented with an asset management interface 600 that can enable a user to manage their digital assets, manage inheriting users, and prepare their memorial. As shown, the asset management interface 600 includes a digital asset section 605 where a user can store digital assets. The digital asset section 605 can include multiple folders and/or directories that can be used by a user to manage their digital assets. A user can drag and drop digital assets into the folders included in the digital asset section 605 to store their digital assets.
[0112] The asset management interface 600 can also include an inheriting user section 610 that identifies the inheriting users designated for the primary user. For example, the inheriting user section 610 can include an icon that identifies each inheriting user designated by the primary user to inherit digital assets upon the passing away of the primary user. In some embodiments, the icon identifying the inheriting user can be selectable to access and configure user settings associated with designating a user as an inheriting user.
[0113] The asset management interface 600 can also include an inheriting user designation section 615 that identifies the user account for which the primary user has been designated as an inheriting users assigned to the primary user's account. For example, the inheriting user designation section 615 can include icons identifying the user accounts that have designated the primary user as an inheriting user. Further, the icons identifying each user account can be selectable to access and configure setting regarding the primary user's designation as an inheriting user. For example, the primary user can opt in or out of being an inheriting user.
[0114] The asset management interface can also include a memorial section 620 that enables a primary user to manage their memorial. For example, the memorial section 620 can enable a user to select to edit their bio, images, etc.
[0115] FIG. 7A , and FIG. 7B illustrate exemplary possible system embodiments. The more appropriate embodiment will be apparent to those of ordinary skill in the art when practicing the present technology. Persons of ordinary skill in the art will also readily appreciate that other system embodiments are possible.
[0116] FIG. 7A illustrates a conventional system bus computing system architecture 700 wherein the components of the system are in electrical communication with each other using a bus 705 . Exemplary system 700 includes a processing unit (CPU or processor) 710 and a system bus 705 that couples various system components including the system memory 715 , such as read only memory (ROM) 720 and random access memory (RAM) 725 , to the processor 710 . The system 700 can include a cache of high-speed memory connected directly with, in close proximity to, or integrated as part of the processor 710 . The system 700 can copy data from the memory 715 and/or the storage device 730 to the cache 712 for quick access by the processor 710 . In this way, the cache can provide a performance boost that avoids processor 710 delays while waiting for data. These and other modules can control or be configured to control the processor 710 to perform various actions. Other system memory 715 may be available for use as well. The memory 715 can include multiple different types of memory with different performance characteristics. The processor 710 can include any general purpose processor and a hardware module or software module, such as module 1 732 , module 2 734 , and module 3 736 stored in storage device 730 , configured to control the processor 710 as well as a special-purpose processor where software instructions are incorporated into the actual processor design. The processor 710 may essentially be a completely self-contained computing system, containing multiple cores or processors, a bus, memory controller, cache, etc. A multi-core processor may be symmetric or asymmetric.
[0117] To enable user interaction with the computing device 700 , an input device 745 can represent any number of input mechanisms, such as a microphone for speech, a touch-sensitive screen for gesture or graphical input, keyboard, mouse, motion input, speech and so forth. An output device 735 can also be one or more of a number of output mechanisms known to those of skill in the art. In some instances, multimodal systems can enable a user to provide multiple types of input to communicate with the computing device 700 . The communications interface 740 can generally govern and manage the user input and system output. There is no restriction on operating on any particular hardware arrangement and therefore the basic features here may easily be substituted for improved hardware or firmware arrangements as they are developed.
[0118] Storage device 730 is a non-volatile memory and can be a hard disk or other types of computer readable media which can store data that are accessible by a computer, such as magnetic cassettes, flash memory cards, solid state memory devices, digital versatile disks, cartridges, random access memories (RAMs) 725 , read only memory (ROM) 720 , and hybrids thereof.
[0119] The storage device 730 can include software modules 732 , 734 , 736 for controlling the processor 710 . Other hardware or software modules are contemplated. The storage device 730 can be connected to the system bus 705 . In one aspect, a hardware module that performs a particular function can include the software component stored in a computer-readable medium in connection with the necessary hardware components, such as the processor 710 , bus 705 , display 735 , and so forth, to carry out the function.
[0120] FIG. 7B illustrates a computer system 750 having a chipset architecture that can be used in executing the described method and generating and displaying a graphical user interface (GUI). Computer system 750 is an example of computer hardware, software, and firmware that can be used to implement the disclosed technology. System 750 can include a processor 755 , representative of any number of physically and/or logically distinct resources capable of executing software, firmware, and hardware configured to perform identified computations. Processor 755 can communicate with a chipset 760 that can control input to and output from processor 755 . In this example, chipset 760 outputs information to output 765 , such as a display, and can read and write information to storage device 770 , which can include magnetic media, and solid state media, for example. Chipset 760 can also read data from and write data to RAM 775 . A bridge 780 for interfacing with a variety of user interface components 785 can be provided for interfacing with chipset 760 . Such user interface components 785 can include a keyboard, a microphone, touch detection and processing circuitry, a pointing device, such as a mouse, and so on. In general, inputs to system 750 can come from any of a variety of sources, machine generated and/or human generated.
[0121] Chipset 760 can also interface with one or more communication interfaces 790 that can have different physical interfaces. Such communication interfaces can include interfaces for wired and wireless local area networks, for broadband wireless networks, as well as personal area networks. Some applications of the methods for generating, displaying, and using the GUI disclosed herein can include receiving ordered datasets over the physical interface or be generated by the machine itself by processor 755 analyzing data stored in storage 770 or 775 . Further, the machine can receive inputs from a user via user interface components 785 and execute appropriate functions, such as browsing functions by interpreting these inputs using processor 755 .
[0122] It can be appreciated that exemplary systems 700 and 750 can have more than one processor 710 or be part of a group or cluster of computing devices networked together to provide greater processing capability.
[0123] For clarity of explanation, in some instances the present technology may be presented as including individual functional blocks including functional blocks comprising devices, device components, steps or routines in a method embodied in software, or combinations of hardware and software.
[0124] In some embodiments the computer-readable storage devices, mediums, and memories can include a cable or wireless signal containing a bit stream and the like. However, when mentioned, non-transitory computer-readable storage media expressly exclude media such as energy, carrier signals, electromagnetic waves, and signals per se.
[0125] Methods according to the above-described examples can be implemented using computer-executable instructions that are stored or otherwise available from computer readable media. Such instructions can comprise, for example, instructions and data which cause or otherwise configure a general purpose computer, special purpose computer, or special purpose processing device to perform a certain function or group of functions. Portions of computer resources used can be accessible over a network. The computer executable instructions may be, for example, binaries, intermediate format instructions such as assembly language, firmware, or source code. Examples of computer-readable media that may be used to store instructions, information used, and/or information created during methods according to described examples include magnetic or optical disks, flash memory, USB devices provided with non-volatile memory, networked storage devices, and so on.
[0126] Devices implementing methods according to these disclosures can comprise hardware, firmware and/or software, and can take any of a variety of form factors. Typical examples of such form factors include laptops, smart phones, small form factor personal computers, personal digital assistants, and so on. Functionality described herein also can be embodied in peripherals or add-in cards. Such functionality can also be implemented on a circuit board among different chips or different processes executing in a single device, by way of further example.
[0127] The instructions, media for conveying such instructions, computing resources for executing them, and other structures for supporting such computing resources are means for providing the functions described in these disclosures.
[0128] Although a variety of examples and other information was used to explain aspects within the scope of the appended claims, no limitation of the claims should be implied based on particular features or arrangements in such examples, as one of ordinary skill would be able to use these examples to derive a wide variety of implementations. Further and although some subject matter may have been described in language specific to examples of structural features and/or method steps, it is to be understood that the subject matter defined in the appended claims is not necessarily limited to these described features or acts. For example, such functionality can be distributed differently or performed in components other than those identified herein. Rather, the described features and steps are disclosed as examples of components of systems and methods within the scope of the appended claims. | An asset management system implements machine-based management and transfer of digital assets. The system enables creation and storage of digital assets, which can be accessed and/or modified by one or more authenticated users. The asset management system enables designation of one or more inheriting users to have access to the digital asset(s) in the event that a programmatic trigger condition is satisfied. In response to input from a user, the asset management system creates one or more programmatic trigger conditions with various inputs which must be satisfied in order for a digital asset transfer to take place. The asset management system defines one or more actions to take place upon a determination that the programmatic trigger condition(s) is satisfied. Permissions associated with the digital asset(s) can be modified to authorize one or more inheriting users to access the digital assets in a manner authorized by a primary user. A variety of other automated actions can be defined by the system to occur in association with execution of the digital asset transfer. | 7 |
BACKGROUND OF THE INVENTION
[0001] The present invention relates to power converter apparatus and methods, and more particularly, to clamped converters, asymmetrical half-bridges, and similar power conversion apparatus that use a clamped inductance.
[0002] DC-DC converters and other power conversion apparatus often use “clamped converter” and “asymmetrical half-bridge” configurations. A common feature of such devices is the use of a power conversion cycle in which a transformer winding, inductor or other inductance is energized in an “on” phase by application of an input voltage (directly or via magnetic coupling) and then “clamped” during an “off” phase using a capacitor and/or other circuitry that receives magnetizing energy from the inductance. Examples of such converter configurations may be found in U.S. Pat. No. 4,441,146 to Vinciarelli; U.S. Pat. No. 4,959,764 to Bassett; U.S. Pat. No. 5,291,382 to Cohen; “Small-Signal Modeling of Soft-Switched Asymmetric Half-Bridge DC/DC Converter,” by Korotkov et al, IEEE Applied Power Electronics Conference, Record, 1995, p. 707-711.
[0003] Many conventional clamped converter and asymmetrical half-bridge designs use a capacitor to receive energy during the “off” phase. A potential drawback of such circuits is that an abrupt change in the converter's duty cycle can lead to an incomplete energy transfer during the “off” phase due to premature entry into the “on” phase. This can lead to undesirably large peak currents in the inductance. For example, in a transformer-type clamped converter, an abrupt change in duty cycle may lead to excessive magnetizing current in the transformer, which can, in turn, lead to saturation of the transformer. In circuits that use a transistor with an integral body diode to switch the clamping circuit, such premature entry into the “on” phase can also damage the transistor through uncontrolled reverse recovery of the body diode.
SUMMARY OF THE INVENTION
[0004] In some embodiments of the invention, a power converter apparatus, such as a DC-DC converter, power supply, or the like, includes an input port, an output port, an inductance, a clamping circuit coupled to the inductance and an output circuit coupled to the inductor and the output port. The inductance may include, for example, a transformer winding and/or a discrete inductor. The apparatus also includes a switch operative to control energy transfer between the input port and the inductance. The apparatus further includes a control circuit operative to control the switch responsive to a current in the inductance while current is being transferred between the inductance and the clamping circuit. For example, the control circuit may include a current sensor configured to be coupled in series with the inductance while current is being transferred between the inductance and the clamping circuit and operative to generate a current sense signal indicative of the current in the inductance, along with a switch control circuit operative to control the first switch responsive to the current sense signal. The switch control circuit may be operative to prevent transition of the switch from the first state to the second state until the current sense signal meets a predetermined criterion, e.g., a signal state indicative of a desired current condition, such as a current approximating zero or a current reversal.
[0005] In further embodiments of the invention, the switch includes a first switch. The clamping circuit includes an impedance, such as a capacitor, a second switch operative to control current flow between the impedance and the inductance, and a clamping control circuit operative to control the second switch. The second switch may include a transistor that is responsive to a clamping control signal, and a diode, such as a transistor body diode, coupled in parallel with the transistor. A current limiting circuit may be provided to limit current in the second switch. In some embodiments, the current limiting circuit may be asymmetrical, i.e., may provide a variable impedance responsive to the direction of the current between the impedance and the inductance.
[0006] In other embodiments of the invention, a power converter apparatus includes an input port, an output port, and an inductance. A first switch is coupled to the input port and the inductance and controls current flow between the input port and the inductance. A second switch is coupled to an impedance and the inductance, and controls current flow between the impedance and the inductance. A control circuit operates the first and second switches in a substantially complementary fashion to provide energy transfer between the inductance and respective ones of the input port and the impedance, and is further operative to control operation of the first switch responsive to a current in the inductance. An output circuit couples the inductance to the output port.
[0007] In method embodiments of the invention, a power converter apparatus that transfers energy from a power source to a load by cyclically energizing an inductance is operated. The power source is decoupled from the inductance. The inductance is then clamped while sensing a current therein. The power source is then coupled to the inductance responsive to the sensed current.
[0008] Embodiments of the invention may provide significant advantages over convention converter configurations. In particular, by controlling coupling of a clamped inductance to a power source responsive to current in the inductance while it is being clamped, e.g., responsive to a sensed current in the clamping circuit, the present invention may limit peak current generated in the inductance during transient conditions when the charging/clamping cycle of the inductance abruptly changes and, thus, may prevent saturation of the inductance. In some converter configurations, the invention may also reduce damaging effects, such as uncontrolled reverse recovery of switching diodes.
BRIEF DESCRIPTION OF THE DRAWINGS
[0009] [0009]FIG. 1 is a schematic diagram of a clamped converter apparatus according to embodiments of the invention.
[0010] [0010]FIG. 2 is a schematic diagram of a clamped converter apparatus according to other embodiments of the invention.
[0011] [0011]FIG. 3 is a schematic diagram illustrating a clamped converter apparatus with an exemplary control circuit configuration according to some embodiments of the invention.
[0012] [0012]FIGS. 4A and 4B are waveform diagrams illustrating exemplary operations of the converter apparatus of FIG. 3 according to embodiments of the invention.
[0013] [0013]FIG. 5 is a schematic diagram illustrating a clamped converter apparatus with an exemplary current limiting circuit configuration according to some embodiments of the invention.
[0014] [0014]FIG. 6 is a schematic diagram illustrating a power converter apparatus according to still further embodiments of the invention.
[0015] [0015]FIG. 7 is a schematic diagram illustrating a power converter apparatus with an exemplary current limit/current sense circuit according to some embodiments of the invention.
[0016] [0016]FIG. 8 is a schematic diagram illustrating still another power converter configuration according to embodiments of the invention.
[0017] [0017]FIG. 9 is a schematic diagram illustrating a power converter apparatus with an exemplary current limit circuit according to still further embodiments of the invention.
DETAILED DESCRIPTION
[0018] Specific embodiments of the invention now will be described more fully with reference to the accompanying drawings. This invention may, however, be embodied in many different forms and should not be construed as limited to the embodiments set forth herein; rather, these embodiments are provided so that this disclosure will be thorough and complete, and will fully convey the scope of the invention to those skilled in the art.
[0019] [0019]FIG. 1 illustrates a power converter apparatus 100 according to embodiments of the invention. The apparatus 100 includes an input port 110 a , 110 b at which a voltage v in , for example, a DC voltage produced by a rectifier, may be applied. The apparatus 100 also includes an output port 140 a , 140 b , an inductance in the form of a primary winding 122 of a transformer 122 , a clamping circuit 170 and an output circuit 130 , here shown as including a secondary winding 124 of the transformer 120 , coupled to the inductance 122 and the output port 140 a , 140 b . The apparatus further includes a switch 150 that is operative to couple and decouple the input port 110 a , 110 b and the inductance 122 to selectively apply the input voltage v in thereto. The apparatus 100 further includes a control circuit 160 , here shown as including a current sensor 162 coupled in series with the clamping circuit 170 and a switch control circuit 164 that is responsive to the current sensor 162 . The control circuit 160 is operative to sense a current in the inductance 122 while the clamping circuit 170 receives current from the inductance 122 . The control circuit 160 is further operative to control the switch 150 responsive to the current in the inductance 122 .
[0020] It will be understood that, in a particular application, the converter apparatus 100 will typically include other components. In particular, the control circuit 160 and/or the clamping circuit 170 may be further controlled responsive to, for example, a voltage and/or current at the output port 140 a , 140 b , or to another circuit state, such as a voltage and/or current of additional circuitry coupled to the apparatus. For purposes of the generality of description, detailed discussion of such voltage and/or current feedback control techniques will not be provided herein.
[0021] It also will be appreciated that the configuration of FIG. 1 may be modified within the scope of the invention. For example, rather than using a current sensor 162 coupled in series with a clamping circuit 170 as shown in FIG. 1, other current sensing techniques can be used with the invention, including, for example, a current sensor coupled in series with the inductance 122 .
[0022] It will also be understood that the invention is not limited to the “clamped converter” configuration shown in FIG. 1. In general, the invention is also applicable to a variety of power converter configurations, including configurations that use types of inductances other than transformer windings. The invention is also generally applicable to configurations using a variety of different types of clamping circuits, including, but not limited to, resonant (e.g., capacitive) clamping circuits, dissipative (e.g., resistive) clamping circuits, and combinations thereof. Moreover, the invention may be embodied in a variety of different types of devices, such as DC-DC converters, power supply devices, uninterruptible power supply (UPS) devices, and the like. The invention generally may be implemented using discrete electrical components, integrated circuits, and combinations thereof.
[0023] [0023]FIG. 2 illustrates a power converter apparatus 200 according to other embodiments of the invention. The apparatus 200 includes an input port 210 a , 210 b , an output port 240 a , 240 b , an inductance in the form of a primary winding 222 of a transformer 220 , and an output circuit 230 , here shown as including a secondary winding 224 of the transformer 220 , coupled to the inductance 222 and the output port 240 a , 240 b . A switch 250 , here shown as including a transistor Q and associated body diode DB, is operative to couple and decouple the input port 210 a , 210 b and the inductance 222 to selectively apply an input voltage v in thereto. A clamping circuit 270 includes a capacitor C and second switch 272 , here shown as including a transistor Q and a body diode DB, that is operative to control current flow between the capacitor C and the inductance 222 .
[0024] A current sensor 262 is coupled in series with the switch 272 and is operative to sense a current in the inductance 222 while the switch 272 couples the clamping capacitor C across the inductance 222 . A switch control circuit 264 generates respective control signals that are applied to respective ones of the switches 250 , 272 . In particular, the switch control circuit 264 is operative to control the switch 250 responsive to a current sense signal 263 generated by the current sensor 262 .
[0025] As illustrated in FIG. 3, a power converter apparatus 300 according to other embodiments of the present invention is similar to the apparatus 200 of FIG. 2, with like components being indicated by like reference numerals, description of which is provided in the foregoing discussion of FIG. 2. The apparatus 300 includes a switch control circuit 264 ′ including a switching signal generator circuit 310 that generates first and second switch control signals S 1 , S 2 . The switch control signal S 1 is applied to an AND gate circuit 320 , which also receives a current sense signal SCS generated by a current sensor 262 ′ coupled in series with a clamping circuit 270 . The AND gate 320 generates a control signal S 1 ′ that is applied to the switch 250 , which controls current flow between the inductance 222 and the input port 210 a , 210 b responsively thereto.
[0026] Exemplary operations of the apparatus 300 may be understood by reference to FIGS. 4A and 4B. In the embodiments illustrated in FIGS. 3, 4A and 4 B, the first and second drive signals S 1 , S 2 transition in a substantially complementary fashion, i.e., in a complementary fashion that may incorporate a small amount of “dead time” such that signal S 1 delays transition to a “high” state for a short period after transition of the signal S 2 to a “low” state, and/or vice versa. Generation of the control signals S 1 , S 2 may be achieved via any of a number of conventional control techniques commonly used in clamped converter apparatus, for example, using voltage and/or current feedback techniques.
[0027] Prior to a time t 1 , it is assumed that the first and second signals S 1 , S 2 transition at substantially constant complementary duty cycles such that the first signal S 1 has a duty cycle approaching 0% and such that the second signal S 2 has a duty cycle approaching 100%, i.e., such that the second signal S 2 is at nearly a continuous “high” state while the first signal is at nearly a continuous “low” state. As a result, the switch 272 of the clamping circuit 272 is “on” substantially more than the switch 250 . Accordingly, the current i 1 in the inductance 222 remains relatively low and, consequently, the voltage v C across the clamping capacitor C remains relatively low. Such a condition might occur, for example, when the apparatus 300 is lightly loaded at the output port 240 a , 240 b.
[0028] At time t 1 , however, the duty cycles of the signals S 1 , S 2 abruptly change such that the duty cycle of the signal S 1 abruptly increases to around near 50% and the duty cycle of the switch S 2 abruptly decreases to around 50%. Such a change might occur, for example, in response to an increase in load at the output port 240 a , 240 b . In a first “on” interval of the switch 250 from time t 1 to time t 2 , the current i 1 ramps up to a relatively high level, such that, when the switch 250 is turned off at time t 2 and the switch 272 turns “on” by forward biasing of the body diode D B shortly thereafter, a relatively large current i 2 begins to flow from the inductance 222 to the capacitor C. Because the decay time for this large initial current is relatively long due to the highly discharged state of the capacitor at time t 2 , the current i 2 remains relatively high when the signal S 1 goes “high” again at time t 3 . However, the current sense signal SCS remains “low” due to the positive, nonzero level of the current i 2 , maintaining the switch 250 in an “off” state until the current i 2 falls to near zero at time t 4 , several cycles of the signals S 1 , S 2 later. For the operations illustrated in FIGS. 4A and 4B, this current limiting action continues for subsequent cycles of the signals S 1 , S 2 . However, assuming that the duty cycles of the signals S 1 , S 2 remain relatively constant, the converter may approach a steady state, wherein the current i 2 reaches zero before each new rising edge of the signal S 1 and the voltage v C remains relatively constant. The action of the current sense signal SCS serves to limit the peak value of the current generated in the inductance 222 during the transient period following the abrupt change in the substantially complementary duty cycles of the signals S 1 , S 2 at time t 1 . This can prevent saturation of the transformer 220 . The action of the current sense signal SCS can also provide a more controlled reverse recovery of the body diode D B of the switch 272 .
[0029] It will be understood that apparatus and operations described with reference to FIGS. 3 and 4A- 4 B may be modified within the scope of the invention. For example, rather than configure the current sensor 262 ′ to transition the current sense signal SCS when the current i 2 is approximately zero, the current sensor 262 ′ could be configured to transition the current sense signal SCS at some other current level, such as a positive level that can still provide saturation protection, or a negative level that can provide better reverse recovery for the body diode D B of the switch 272 .
[0030] [0030]FIG. 5 illustrates a converter apparatus 500 according to other embodiments of the invention. The converter apparatus 500 is similar to the apparatus 200 of FIG. 2, with like components indicated by like reference numerals, description of which is provided in the foregoing description of FIG. 2. The converter apparatus 500 further includes an asymmetrical current limiting circuit 280 coupled in series with the clamping circuit 270 . Here shown as including a current limiting resistor R CL connected in parallel with a bypass diode D BP , the asymmetrical current limiting circuit 280 serves to limit current in the switch 272 of the clamping circuit 270 in an asymmetrical fashion. In particular, the current limiting circuit 270 allows relatively large currents to flow from the inductance 222 to the clamping capacitance C through the forward biasing of the bypass diode D BP , but limits reverse current through the action of the current limiting resistor R CL . This latter characteristic may be particularly advantageous in limiting currents in the switch 272 during transients in which the switch 250 transitions abruptly from a relatively high duty cycle, e.g., near 100% (corresponding to a heavily loaded condition) to a substantially lower duty cycle, with concomitant transitioning of the switch 272 from a relatively low duty cycle, e.g., near 0%, to a substantially higher duty cycle. Although the bypass diode D BP could be omitted, its presence can reduce unnecessary power dissipation in comparison to use of the current limiting resistor R CL alone.
[0031] As noted above, the invention is not limited to “clamped converter” embodiments, and is generally applicable to many types of converter configurations that cyclically charge a transformer winding, inductor, or other inductance and “clamp” the charged inductance using a resonant, dissipative or other type of clamping circuit. For example, as illustrated in FIG. 6, a converter 600 according to embodiments of the invention may have a structure like that found in an asymmetrical half-bridge converter. As shown, the converter 600 includes a first switch 620 that control current flow between and inductance L and an input port 610 a , 610 b at which an input voltage v in is applied. As shown, the first switch 620 includes a transistor Q and associated body diode D B . Current flow between the inductance L and a clamping capacitance C is controlled by a second switch 630 , here also shown as including a transistor Q and associated body diode D B . The inductance L may be coupled to an output port (not shown for purposes of generality of illustration) in a number of different ways, including, for example, via magnetic coupling (as in a transformer) or electrical coupling to the inductance L.
[0032] A switch control circuit 664 controls the first and second switches 620 , 630 . In particular, the switch control circuit 664 controls the first switch 620 responsive to a current sense signal generated by a current sensor 662 coupled in series with the clamping capacitor C. Much like the embodiments described above with reference to FIGS. 1 - 5 , the switch control circuit 664 operates the switches 620 , 630 in a substantially complementary fashion. The switch control circuit 664 is further operative to condition closure of the switch 620 responsive to the current in the inductance L while the capacitor C is still coupled to the inductance L. In this manner, peak current in the inductance L can be limited, and reverse recovery of the body diode DB of the switch 630 can be controlled.
[0033] [0033]FIG. 7 illustrates a converter apparatus 700 according to other embodiments of the invention. The apparatus 700 is similar to the apparatus 600 , with like components illustrated by like reference numerals, description of which is provided in the foregoing description of FIG. 6. The apparatus 700 includes a combined current limiting/current sensing circuit including a current limiting resistor R CL , a bypass diode D BP , and a current sense diode D CS coupled in series with the current limiting resistor R CL . A voltage v CS at a node 680 at which the current limiting resistor R CL is coupled to the clamping capacitor C serves as a current sense signal provided to a switch control circuit 664 ′ that controls the first and second switches 620 , 630 . Along the lines of the switch control circuit 664 of FIG. 6, the switch control circuit 664 ′ is operative to condition closure of the switch 620 responsive to the current sense signal v CS , which is representative of the current in the inductance L while the capacitor C is coupled to the inductance L.
[0034] In particular, assuming the voltage at the second terminal 610 b of the input port is signal ground (zero volts), when the current i C in the clamping capacitor C is positive (in the sense defined by the arrow), the voltage v CS is approximately one diode drop (e.g., 0.6 volts) positive due to the forward biasing of the bypass diode D BP . However, when the current ic approaches zero and passes to a negative value, the bypass diode becomes reversed biased, and the current sense diode D CS becomes forward biased. This causes the current sense voltage v CS to transition to at least one diode drop negative (e.g., −0.6 volts or lower). This change in voltage can be detected by the switch control circuit 664 ′, which may responsively enable closure of the first switch 620 . For example, the switch control circuit 664 ′ may include, for example, comparator and/or other signal detection circuitry that detects such a transition of the current sense voltage v CS . In this manner, saturation of the inductance L and/or reverse recovery of the body diode D B of the switch 630 can be controlled.
[0035] [0035]FIG. 8 illustrates yet another possible converter topology according to embodiments of the invention. The converter apparatus includes an inductance L and a clamping capacitance C. As with the converter apparatus of FIGS. 6 and 7, the inductance L may be coupled to an output port (not shown for purposes of generality of illustration) in a number of different ways, including magnetic and electrical coupling. A first switch 820 , including a transistor Q and associated body diode D B , is operative to control current flow between the inductance L and an input port 810 a , 810 b at which an input voltage v in is applied. A second switch 830 , also including a transistor Q and body diode D B , is operative to control current flow between the clamping capacitor C and the inductance L. A switch control circuit 864 operates the first and second switches 820 , 830 in a substantially complementary fashion, and is further operative to condition operation of the switch 820 on a current sense signal v CS generated at a node 880 at which the second switch 830 is connected to a current limit/current sense circuit including a current limiting resistor R CL , a bypass diode D BP , and a current sense diode D CS . The current limit/current sense circuit can operate in a manner similar to that described with reference to FIG. 7.
[0036] [0036]FIG. 9 illustrates a converter apparatus 900 according to yet other embodiments of the invention. The apparatus 900 is similar to the apparatus 800 of FIG. 8, with like elements indicated by like reference numerals, description of which is provided above with reference to FIG. 8. The apparatus 900 differs from the apparatus 800 in that the current limiting resistor R CL and bypass diode D BP are moved to the other side of the transistor switch 830 . This allows the switch 830 to operate in a linear, current limiting manner when current i C in the clamping capacitance C becomes excessive in the negative direction. A current sensor 862 coupled in series with the switch 830 provides a current sense signal to a switch control circuit 864 ′ that controls the first and second switches 820 , 830 .
[0037] In the drawings and foregoing description thereof, there have been disclosed typical embodiments of the invention. Terms employed in the description are used in a generic and descriptive sense and not for purposes of limitation, the scope of the invention being set forth in the following claims | A power converter apparatus, such as a DC-DC converter, includes a switch that controls current transfer between an input port and an inductance. A control circuit is operative, while current is being transferred between the inductance and a clamping circuit, to control the switch responsive to a current in the inductance. For example, the control circuit may include a current sensor configured to be coupled in series with the inductance and a switch control circuit operative to control the first switch responsive to a current sense signal generated by the current sensor. The switch control circuit may be operative to prevent transition of the switch from the first state to the second state until the current sense signal meets a predetermined criterion, e.g., a signal state indicative of a desired current condition, such as a current approximating zero or a current reversal. Related operating methods are also discussed. | 8 |
[0001] Related U.S. Pat. No. 5,919,471
[0000] This application is a continuation-in-part of application Ser. No. 11/118,197 filed May 2, 2005.
FIELD OF INVENTION
[0002] The present invention relates to a personal-skin-cleansing wipe incorporating a non-aqueous solvent, a surfactant, and an antimicrobial/antifungal/antiseptic component. The wipe contains PVP-iodine as an active, which is incorporated in substantially anhydrous form to produce a wipe that is substantially dry. The wipe is activated by the addition of water before use and residual debris, including PVP-iodine remaining on the skin following use are removed by rinsing with water. The structure of the wipe should preferably comprise synthetic fibers. The wipe can be used as an antiseptic hand washcloth, an antifungal body or skin wipe for first aid or wound cleansing, among other applications.
BACKGROUND OF THE INVENTION
[0003] It is well known that topical skin surfaces of humans, from time to time, need to be cleaned and desirably, sanitized.
[0004] Currently, there are only over-the-counter antimicrobial active ingredients enjoying unqualified approval by the U.S. Food and Drug Administration for use in antiseptic skin cleansing, for first aid and wound cleansing, and in antifungal cleansing wipes.
[0005] The first, ethyl alcohol, has a long history of safe and effective use. However, there is a long list of negative attributes associated with the use of the ethyl alcohol. It dries and irritates healthy skin and stings injured or abraded skin. Moreover, as ethyl alcohol is highly volatile; it dissipates rapidly and thus has a short duration of antimicrobial effectiveness.
[0006] The other disadvantages of ethyl alcohol include its stringent regulation by governmental agencies, its ability to erode some metals, its tendency to remove paint and varnish and to delaminate some plastics.
[0007] Other approved antimicrobial ingredient is PVP-iodine (also called Povidone-iodine), which is a stable complex of polyvinylpyrrolidone (PVP) and elemental iodine. While elemental iodine has been used in antiseptic applications (U.S. Pat. No. 4,045,364), elemental iodine is known to possess a number of undesirable properties. Free elemental iodine is highly toxic, irritative, sensitizing, odorous and it also causes stains and readily vaporizes due to sublimation. U.S. Pat. No. 2,739,922 teaches the complex of PVP and iodine, which possesses reduced objectionable properties and increased bactericidal activity as compared to free elemental iodine. PVP-iodine has a variety of uses in health care on both skin and hard surfaces as an effective germicide, bactericide, fungicide, virucide, and amebicide. The use of premoistened wipes to deliver aqueous solutions containing alcohol or PVP-iodine to sanitize skin or to disinfect hard surfaces is longstanding. But such wet wipes are expensive because they require barrier packaging to prevent evaporation or “dryout”. Also contributing to the expense of such wipes is the need for special binder-free substrates for hydro-alcoholic formulations and starch-free substrates for aqueous iodophor formulations. Thus, the use of these ingredients has been limited and reserved for higher risk healthcare and medical environments where other considerations justify the higher costs. U.S. Pat. No. 2,599,140 discloses an iodine-containing detergent using iodine dissolved in a mixture of polyalkylene glycol and glycerin to prevent fast evaporation of elemental iodine. U.S. Pat. No. 4,355,021 discloses a substantially dry virucidal wipe using a flexible paper substrate, having iodine stabilized in polyoxyethylene (40) sorbitol septaoleate. U.S. Pat. No. 4,045,364 discloses dry disposable paper tissues impregnated with elemental iodine or PVP-iodine, which can be packaged and stored for long term without undue deterioration. U.S. Pat. No. 5,919,471 discloses a substantially flexible, dry and antiseptic wipe impregnated with PVP-iodine present in at least one glycol compound.
SUMMARY OF THE INVENTION
[0008] The present invention is focused on an antiseptic skin-cleansing washcloth, or an antimicrobial/antifungal skin cleansing wipe. The wipe is manufactured as a substantially dry matrix into which PVP-iodine and one or more surfactants, in a waterless formulation are mechanically impregnated using glycols as diluents. The matrix is wetted with water and the wet matrix is rubbed on skin to develop a foaming and cleansing formulation which when rinsed washes away residual debris and PVP-iodine with no evident staining or discoloration.
DETAILED DESCRIPTION OF THE INVENTION
[0009] The presence of water is essential in all cleaning applications, such as hand cleaning. However, if these antiseptic wipes were supplied in wet form, the activated iodine risks rapid degradation in the presence of water, and the aqueous iodine would leave visible stains on skin, clothing or hard surfaces. These disadvantages add to the cost of packaging, storing and using the wipes, and most importantly reduce their shelf life time. It has now been found that wipes containing PVP-iodine can be manufactured using a non-aqueous solvent carrier that will yield substantially dry wipes that can be activated with water shortly before use by the end user.
[0010] As used herein, the terms “substantially dry” and “substantially anhydrous” means that less than 0.5% water is present.
[0011] The synthetic matrix is manufactured dry, meaning no water has been added other than the water naturally present in the basic fibers. Typically, these synthetic materials have a moisture content of less that 1%. The term “substantially dry” also encompasses a finished product, i.e., a wipe, into which the anhydrous or substantially anhydrous treatment solution and namely a solution containing less than 0.5% water and containing an antimicrobial and surfactant formulation has been impregnated. The matrix with the treatment solution normally feels dry, and lubricious to the touch.
[0012] The matrix for containing the anhydrous treatment solution used in the present invention comprises synthetic fibers, which may be processed into woven, non-woven or knitted form. Of particular interest for use in the matrix employed in the present invention are the following fibers: polypropylene, polyester, and other synthetics. The matrix can be made of one sole fiber or a mixture of at least two fibers. If the wipe matrix is made of polypropylene and polyester fibers, it is preferred that the matrix contains between 20% and 70% polypropylene and between 30% and 80% polyester fibers.
[0013] In accordance with the invention, PVP-iodine is the antiseptic active. Commercially, PVP-iodine complex is available in a pharmaceutical grade containing 10 parts active halogen per 100 parts of dry powder. For this reason, the commercial product has sometimes been referred to as “PVP-iodine 10.” There are two major suppliers of PVP-iodine: BASF Fine Chemicals and Napp technologies. PVP-iodine is completely soluble in cold water with mild agitation as well as propylene glycol in amounts up to and exceeding 10% (1.0% available iodine). Aqueous solutions of PVP-iodine have been marketed under the trademark BETADINE® microbicides by Purdue Frederick Company as a defense against topical infection from pre-surgical cleansing to hand and skin degerming, as being active against both gram-positive bacteria, fungi, protozoa and viruses, in vitro.
[0014] In general, to reduce microorganisms on skin and prevent infections in skin, topical solutions containing between about 1 and 15% PVP-iodine (0.1 and 1.5% available iodine) may be used. It is preferred that the solution contain between about 5 and 10% PVP-iodine (0.5 and 1% available iodine) and most preferably the solution contain about 10% PVP-iodine (1% available iodine). Anticipating the dilution with water upon wetting prior to use, the initial concentration of PVP-iodine in the manufactured anhydrous solution could contain higher concentration of PVP-iodine.
[0015] The substrate comprises synthetic, woven, non-woven or knitted fibers, or blends thereof. The intended use (hands, body, first aid) dictates the amount of add-on needed to achieve effective skin antisepsis.
[0016] The treatment solution may also contain from about 0.5% to 40% non-ionic or cationic surfactant and preferably about 5% to about 15%. In the case where an amphoteric is the sole surfactant, it is present in larger amounts up to and including about 50% and preferably 10 to 50%. The specific amount of the particular non-ionic or cationic surfactant which is employed within this range will depend upon the detergent activity desired as can be readily determined by one of ordinary skill in the art. Any of the well-known classes of non-ionic and cationic surfactants such as nonyphenol ethoxylates also known as Igepal may be employed in the wipe of the present invention. If the surfactant comprises a combination of nonionic and/or cationic and amphoteric surfactants, the total amount of dry surfactants can be up to about 65% of the total weight of solution. The amount of dry amphoteric surfactant is about 10% to about 45% of the weight of the solution. Illustrative of the nonionic surfactants having favorable detergency and foaming properties and are stable in the presence of iodine are the following:
[0000]
Alcohol Ethoxylate
R(OCH 2 CH 2 )nOH
Name
R
n
Conc.
Manufacturer
Neodol 25-7
C 12 -C 15
7
100%
Shell Manufacturer
Tergitol 15-S-7
C 11 -C 15
7
100%
Union Carbide
Biosoft EA-10
C 10 -C 12
6
100%
Stephan Co.
[0000]
Alkyl Phenol Ethoxylates
RC 6 H 4 (OC 2 H 4 )nOH
Name
R
n
Conc.
Manufacturer
Igepal CO-530
C9
6
100%
Rhone Poulenc
[0017] Amphoteric or zwitteronic surfactants contain two charged groups of different sign. Whereas the positive charge is almost always ammonium, the source of the negative charge may vary (carboxylate, sulphate, sulphonate). There can be cationic (positively charged) or non-ionic (no charge) surfactants in solution, depending on the acidity or the pH of the water.
[0018] The amphoteric surfactants are very mild, making them particularly suited for use in personal care and household cleaning products. The are also used in hand dishwashing liquids because of their high foaming properties.
[0019] Amphoteric surfactants are compatible with all other classes of surfactants and are soluble and effective in the presence of high concentrations of electrolytes, acids, and alkalis.
[0020] The advantage of using an amphoteric surfactant is that povidone iodine is stable in the presence of these foaming surfactants. On the other hand, povidone iodine is not stable in the present of high foaming anionic surfactants. Cationic surfactants tend to be low foamers and non-ionic surfactants are generally for industrial applications and low in foaming properties. A preferred instance of the amphoteric surfactant is cocamidopropyl betaine, the IUPAC name which is 1{[3(dodecanoylamino)propyl](dimethyl)ammonium acetate and CAS number is 86438-79-1. Its structure is shown below:
[0000]
[0021] Cocamidopropyl betaine is classed as a semi-synthetic surfactant/foaming agent. Cocamidopropyl betaine (CAPB) is made from coconut oil reacted with chemicals and is a zwitterionic surfactant with a quaternary ammonium cation in its molecule. It is a viscous pale yellow transparent liquid and is used as a surfactant in bath products like shampoos and hand soaps, and in cosmetics as an emulsifying agent and thickener, and to reduce irritation purely ionic surfactants would cause. It also serves as an antistatic agent in hair conditioners.
[0022] Cocamidopropyl betaine is a derivative of cocamide and glycine betaine. Cocamidopropyl betaine is a medium strength surfactant which most often does not irritate skin or mucus membranes. Some studies indicate it is an allergen. It also has antiseptic properties, making it suitable for personal sanitary products. It is compatible with the other cationic and nonionic surfactants.
[0023] The Goldschmidt Company in Europe an affiliate of Evonik Industries sells cocamidopropyl betaine under the trade name TEGO® BETAIN CK D which is a spray dried product. Other amphoterics include but are not limited to the following: lauryl dimethyl carboxymenthyl betaine, lauryl bis(2-hydroxylpropyl)alpha-carboxy ethyl betaine, cocodimethyl sulfopropyl betaine, myristyl amidopropyl betaine, sodium lauroamphoacetate, sodium alkylaminopropionate and sodium capryloampho hydroxypropyl sulfonate.
[0024] The dry article optionally may contain one or more fragrances for imparting a pleasant odor to the skin. As used herein, the term “fragrance” includes chemicals that can mask unpleasant odors and/or destroy unpleasant odors. When employed, the fragrance is present in the dry wipe in amounts up to 5% of the treatment solution.
[0025] The present invention uses a non-aqueous solvent carrier for PVP-iodine during the manufacturing and storage of the wipes. Glycols are the preferred non-aqueous solvents and propylene glycol is the preferred glycol. The non-aqueous solvent functions not only to dissolve the PVP-iodine, but these solvents also impart emolliency and lubricity to the treatment solution which helps prevent skin breakdown and maintain skin softness.
[0026] The use of propylene glycol instead of water as a solvent is essential. Propylene glycol does not precipitate the release of free iodine, and thereby deplete its effectiveness before its actual use. Propylene glycol, unlike water, actually does preserve the stability of PVP-iodine and facilitates an extended shelf life of the treated wipe. Propylene glycol is a lubricious emollient imparting soothing and softening qualities to the skin. Propylene glycol does not freeze in cold weather. The use of propylene glycol, as a non-aqueous solvent obviates the need for buffers, stabilizers and preservatives which are generally required to be used in aqueous solutions.
[0027] Propylene glycol is an active skin lubricant and emollient as well as the solvent for the PVP-iodine. Typically, propylene glycol the major component in the treatment solutions of the present invention. However, it can also be combined with similar glycols such as glycerin or low molecular weight polyethylene glycols such as PEG-200, PEG-400 etc. Preferably, not more than about 40% by weight of the propylene glycol is replaced with these other glycols.
[0028] The matrix prepared in accordance with one of the methods described above, from which the cleansing wipe or other products of the present invention are obtained, can be coated and impregnated with the non-aqueous treatment solution using any those described in U.S. Pat. No. 5,919,471. The coating/impregnation method enables a uniform and accurate application of all active ingredients and surfactants to the woven or nonwoven matrix of synthetic fibers without the use of carriers and without the need for a separate step to dry the residual solution from the matrix.
[0029] Prior to use by the end users, the wipes are wetted using water. Their use with water will enhance the release of free iodine for efficient antisepsis and will precipitate better cleansing performance. The exclusion of water from the treatment formulation, which is applied to the substrate during manufacturing, provides the many benefits described above in the manufacturing, storage and distribution of the wipe products.
[0030] The following examples are given in order to more completely illustrate the usage benefits of the invention, and are not to be construed in limitation thereof:
Example #1
[0031] Formulation #1 listed below was impregnated into a 4.0 oz. sq. yd. non-woven 100% polypropylene needle punched fabric. Wipes of 8×11 inches were cut from the fabric and were prepared using the technique described in U.S. patent application Ser. No. 10/021,395.
[0000]
Treatment of Wipes
Weight of
Wipes g.
add-on gram
% add on
7.4
1.9
25.7
7.7
1.8
23.4
7.9
1.8
22.8
[0000]
Formulation #1
Wt. Percentage
Ingredients
6.3%
Povidone iodine
30%
BIOSOFT EA-10 (100% water free
concentration manufactured by Stepan)
47.2
Propylene glycol
15%
Glycerine
1.5%
Menthol fragrance
Evaluation
[0032] The treated antiseptic hand wipes were evaluated by wetting both hands under a running faucet. The wet hands were then rubbed with the dry wipe to activate the ingredients. The wipe foamed readily when activated with water from the wet hands. There was very little iodine odor detected, and the cleansing action of the wipe was quickly evident. There was no irritation as the wet wipe was between 5-7 grams. This would produce an iodine concentration of about 1900-PPM. After a few minutes the wipe was discarded and the hands were rinsed under water. There was no staining of the hands, which felt soft and refreshed with a pleasing aroma.
Example #2
[0033] The 4 oz/sq. yd. needle punched 100% polypropylene wipes 8×11 inches were similarly impregnated with formulation #2 listed below:
[0000]
Formulation #2
Wt. Percentage
Ingredients
5%
Povidone iodine
20%
Glycerine
20%
Igepal CO-530 (100% water free concentration
Manufactured by Rhone Polenc.)
53.5%
Propylene Glycol
1.5%
Menthol fragrance
[0000]
TREATMENT OF WIPES
Weight of
Wipes g.
add-on gram
% of add on
7.7
1.1
14.2
7.7
1.3
16.8
Evaluation
[0034] A wipe was lightly wetted with water from a faucet. The wet wipe, which picked up 25 grams of water, was rubbed gently over the hands for one minute. The wipes foamed extensively as the hands were gently scrubbed with the wipe. No odor of iodine was detected. A lubricious feel was detected as the wipe was used on the hands. The wipe was then discarded and the hands were rinsed under water. No staining of the hands was observed and the hands felt smooth, soft and clean with a pleasant aroma. Based on the water pickup of the wipe, the iodine concentration is about 220-PPM.
Example #3
[0035] 11×8 inch wipes were cut from 3 oz./sq. yd. needle punched polyester fabric. Wipes were impregnated with the formulation below:
[0000]
Formulation #3
Wt. Percent
Ingredients
75.0%
Polypropylene glycol
Ethel DA-6 (100% non ionic polyoxyethylene
decyl ether foaming surfactant from Ethox
20.0%
Chemicala LLC)
5%
Povidone iodine
[0000]
Treatment of Wipes
Wt. of wipes
g. add-on
add on
5.7
1.9
33.3
5.6
1.4
25.0
5.6
1.5
26.7
Evaluation
[0036] Hands were wetted under a running faucet. One wipe treated with formulation #3 was rubbed over the wet hands to activate the treatment. The wipe foamed readily when wet and massaged on the hands. There was no odor of iodine detected and no staining of the hands was observed. After one minute of rubbing the wipe over the hands, the wipe was discarded and the hands rinsed in running water. The hands felt soft and clean.
Example #4
[0037] 3 oz./sq. yd. needle punched polyester fabric was cut into 10×8 in. wipes and treated with formulation #4 below.
[0000]
Wt. percentage
Ingredients
74.0%
Propylene glycol
20.0%
Ethal DA-6(non ionic polyoxyethylene
decyl ether foaming surfactant from Ethox
Chemicala LLC)
5.0%
Povidone iodine
1.0%
Crisp Morning Fragrance
[0000]
Wt. of wipe
g. add-on
% add on
5.3
1.4
26.4
5.2
1.5
28.8
5.3
1.6
30.2
Evaluation
[0038] Hands were wetted under a running faucet. A treated polyester needle punched wipe was rubbed over both hands and massaged into the hands for about one minute. Extensive foaming was produced as the wipe was rubbed over the wet hands activating the ingredients in the wipe. Hands felt lubricious and no iodine odor was detected. After one minute, hands were rinsed in running water. Hands were clean and soft and possessed a pleasant fragrance.
Example #5
[0039] 4 oz./sq. yd needle punched polyester fabric was into 8×8 in. wipes. Wipes were treated Formulation # 3 above.
[0000]
Treatment of Wipes
Wt. of wipe
g. add-on
% add on
5.6
2.1
37.5%
5.6
2.0
35.7%
5.7
1.7
29.8%
Evaluation
[0040] Hands were wetted under a running faucet and then treated polyester wipe was gently massaged into the hands for about one minute. The wipe produced an abundance of foam and felt smooth and soft on the skin. After one minute the hands were rinsed under running water and dried. Hands were clean and felt soft.
Example #6
[0041] 4 oz./sq. yd. needle punched polyester fabric was cut into 10×8 inch wipes. Wipes were treated with Formulation #4 above.
[0000]
Treatment of Wipes
Wt. of wipe
g. add-on
% add on
5.7
2.1
36.8%
5.6
1.7
30.3%
5.5
2.0
36.3%
Evaluation
[0042] The 8×8 inch treated needle punched wipe was lightly wetted with water under a faucet. The wipe was then massaged into the hands. Within a few seconds there was abundant foaming and cleaning action. After 30 seconds the wipe was discarded and the hands rinsed under a faucet. Hands felt clean, refreshed and exhibited a pleasant aroma.
Example #7
[0043] 1.5 oz./sq. yd. thermo-bonded polypropylene fabric was cut into 8×10 inch wipes. Wipes were treated with formulation #5 listed below.
[0000]
Wt. Percent
Ingredients
58.0%
Propylene glycol
25.0%
Igepal CO-530 (100% water free concentration
manufactured by Rhone Poulenc)
5%
Povidone iodine
12.0%
Glycerine
[0000]
Treatment of Wipes
Wt. of Wipe
g. add-on
% add on
2.5
0.50
20.0%
2.6
0.40
15.43%
2.6
0.50
19.2%
Evaluation
[0044] Hands were wetted under a running faucet. A treated wipe was rubbed over the wet hands. Foaming was observed within seconds. The wipe was easy to manipulate through the hands and cleaned the hands thoroughly. After 30 seconds the wipe was discarded and the hands rinsed under water. No staining of the hands was observed Hands felt refreshed and soft.
Example #8
[0045] TEGO® BETAIN CKD from Evonik Industries the trade name for a spray dried Cocamidopropyl betaine solid product containing less than 0.5% water. The dry TEGO® BETAIN CKD is dissolved in propylene glycol along with povidone iodine to make the solution listed below.
[0046] Formulation #6 listed below was impregnated into non woven roll goods which can be 100% polypropylene to 100% polyester or mixtures of both in various ratios. The treated roll goods were cut to a preferred size of 8.5×10 inches. The add on treatment can be varied within the range of 1.5 to 4 grams of treatment per 8.5×10 inch wipe.
[0000]
Formulation #6
Wt. Percent
Ingredients
78.4%
Propylene glycol
16.6%
TEGO ® BETAIN CKD
5.0%
Povidone iodine
Evaluation
[0047] The treated dry wipe can be used in various ways. The wipe can be lightly wetted under a faucet and then applied as a body wipe to clean and degerm skin. The wipe can also be placed in 8 to 16 ounces of water in a vessel and squeezed several times under the water to release the active ingredients. The wipe is then applied to skin which both cleans the skin from the functionality of the foaming surfactant and at the same time degerms the skin from the functionality of the povidone iodine. The wipe can be used over again by rewetting with the active solution.
[0048] All the treated wipes were tested on hands either first wetted or by wetting the wipe lightly with water. In all cases the wipes foamed readily providing effective cleansing without staining the skin. The odor of the iodine was either light or not detected at all. When hands were rinsed in water, they felt smooth, soft and appeared clean. | A personal skin cleansing wipe comprising a flexible substantially dry matrix formed from fabrics made of synthetic, woven, non-woven, or knitted fibers impregnated with a substantially anhydrous antimicrobial, antiseptic, antifungal solution in an amount wherein the matrix retains its substantially dry characteristics and the treatment solution includes an amount of PVP-iodine in solution in a glycol, glycerine or mixture thereof. The treatment solution in addition to an effective amount of PVP-iodine as active, contains surfactants (nonionic and/or cationic and/or amphoteric) and optionally a compatible fragrance. The wipe is activated with water just prior to use. | 3 |
CROSS-REFERENCE TO RELATED APPLICATIONS
This application claims the benefit of U.S. Provisional Application No. 60/331,887 filed on Nov. 21, 2001, entitled “METHOD FOR SEMI-AUTOMATIC GENERATION AND BEHAVIORAL COMPARISON OF MODELS,” the contents of which are incorporated herein by reference.
REFERENCE TO GOVERNMENT
This invention was made with Government support under Contract No. F30602-98-C-0046 awarded by the United States Air Force. The Government has certain rights in this invention.
BACKGROUND OF THE INVENTION
Simulating the behavior of a proposed or actual design reduces the effort required to realize and maintain the design. Before expending the time and resources to realize a design, designers may compare the desired and predicted behavior of a design using simulation. After realizing the system into dedicated hardware and software and throughout the design's lifecycle, simulation facilitates understanding of unexpected design behaviors and subsequent evaluation of proposed design modifications.
When designers employ a general purpose computer or special purpose simulation accelerator to conduct simulation, the simulated design behavior is usually many times slower than the realized design. Using simulation to predict the design's behavior over lengthy periods of simulated time generally requires undesirably long periods of actual or wallclock time, perhaps consuming days to simulate a mere second in the lifetime of the realized design. Delays before simulation results are available incur an expense in time, an expense in computing resources and delay initial design realization or modification. Therefore methods for improving simulation speed and accuracy, such as those taught in the present invention, are useful and valuable.
Design behavior may be simulated at many different levels of detail. Abstract models of design behavior, with comparatively little detail generally simulate comparatively fast. By adding more detail to the model of a design, the predicted and actual design behavior generally converge while the rate of simulated and actual design behavior diverge. Equivalently, simulation generally becomes increasingly slower as the accuracy of detail increases.
The most abstract simulations, and thus faster simulations, generally approximate the design's state to discrete values in both value and time. Such simulations are commonly known as “digital”. Simulations with more accurate detail represent a design using continuous values and time. Such continuous simulations are known as “analog”. Due to the speed penalty associated with analog simulation, large system simulations typically utilize a mixture of digital and analog simulation techniques, known as mixed signal simulation. Simulations using a mixture of digital and analog detail are known as “mixed signal”. The most accurate simulations represent a design using physically continuous fields and wave propagation, such as electronic and magnetic fields embodied in Maxwell's equations (and continuity equations). Such accurate but slow simulations are often known as “full-wave” simulations.
More detailed simulations are not only slower, they impose a significant effort on the design team in order to accurately “model” a system's behavior so that it can be simulated. Designers or model extraction tools typically represent a design's behavior using one or more modeling languages. Structure modeling languages, such as SPICE, represent a system in terms of flat or hierarchically connected components. A structural modeling language represents terminal components using behavioral models described using a conventional programming language, such as C or Fortran, or a behavioral modeling language, such as VHDL or Verilog (digital), VHDL-AMS or Verilog-AMS (mixed signal). Radio frequency and microwave (RF/MW) languages, perhaps augmenting a base language such as VHDL-AMS or Verilog-AMS, typically add modeling language features such as means for modeling distributed (rather than lumped) parameter components, means for component modeling in the frequency domain (rather than just the time domain) and means of effectively modeling noise and parasitic interactions.
A conventional programming language or behavioral modeling language represents system behavior using terminals, branches and equations representing an implicit relationship between quantities (the implicit relationship embodied as Kirchoff's laws for the analog and mixed signal or Maxwell's and continuity equations for full-wave modeling). Terminals, sometimes known as “nodes”, represent the connection point between two or more branches. The network formed by terminals connected by branches may be represented as one or more disconnected graphs embodying terminals and branches with associated across quantities, such as voltage, and through quantities or contributions, such as current.
FIG. 1 represents the relationship between terminals (such as 152 , 154 , 156 , 159 , 162 , 164 , 166 and 168 ), branches (such as 153 , 155 , 157 , 158 , 163 , 165 , 167 , 169 ) and implied quantities such as through quantity Q 2 ( 172 ) or across quantity Q 1 ( 151 ). Well known techniques provide for partitioning analog models which do not share terminals, branches or quantities, such as the partitions marked 150 and 169 in FIG. 1 . Recognizing such partitions early in the compilation process will become useful in the present invention; means for recognizing such disconnected partitions are well-known.
Beyond a structural view embodied in terminals, branches and quantities, analog modeling languages enable declaration and reference to continuously valued state variable quantities representing physical properties, such as voltage or current, and quantities implicitly or explicitly derived from such quantities. Mixed signal modeling languages enable reference to digital objects such as signals, shared variables, registers and comparable, discretely-valued objects. Such digital objects may be contained in a distinct digital partition, such as 170 in FIG. 1 and referenced from both the digital partition and zero or more analog partitions, such as 150 or 169 in FIG. 1 .
Source code references in a model using a mixed signal language, such as VHDL-AMS, Verilog-AMS or MAST, typically take the form of one or more constraints relating left and right hand side expressions at a specific instant in time to within an implicit or explicit tolerance. Sets of such equations referencing common quantities and digital objects (a partition) are commonly known as systems of equations, characteristic equations, simultaneous equations or constraint equations. Without loss of generality we will refer to these as equation systems in the following.
Many designs of practical interest build on algebraic differential equations by using integrals and differentials of quantities with respect to time (ordinary differential equations) or other state variables (partial differential equations). Three examples will help to illustrate the key differences. An idealized voltage source and resistor tree used as a voltage divider can readily be described using an algebraic equation system. A perfect capacitor integrates change over time, requiring an ordinary differential equation to describe an idealized voltage source driving a resistor and capacitor design. A pair of conductors in close proximity, driven by distinct signal sources generally requires a partial differential equation to model the voltage induced by one conductor on the second conductor.
The behavior of an analog partition may be modeled in the time domain (primary independent variable is time) or in the frequency domain (primary independent variable is frequency). For example the behavior of a voltage-controlled oscillator may be most conveniently modeled in the time domain whereas the transfer function of a filter or amplifier may be most easily and compactly captured in the frequency domain. The prior art effectively addresses many aspects of modeling in either domain, however prior art does not effectively address tight integration of digital inputs, analog time domain behavior and analog frequency domain behavior into a common analog partition or partitions.
Techniques are well-known to convert structural representations, such as commonly evolve from use of the SPICE modeling language using terminals and branches, into systems of equations. With this well-accepted transformation in mind, further discussion will speak of equation systems with the understanding that these systems may originate in many forms, including structural and graph-oriented languages.
The left or right hand side of inequalities within an equation system may result from evaluation of substantially complex expressions involving constructs such as procedural control flow, conditional statements and analog events. Without loss of generality, such notations may be compiled into a variety of equivalent forms corresponding to sets of equation systems where an expression and evolving state may be evaluated to identify an active equation system at any instant in time from among the set of equation systems potentially modeling an analog, mixed-signal or full-wave partition's behavior. Each such equation includes one or more language-defined means for evaluating an identifiable value or range of values on the left and right side of each inequality within the equation system. Such values are generally known to have either scalar or composite type.
From one instant in time to another, both quantity values and the equation system which is active within a set of equations systems describing an analog partition may change. The change may be implicit in the set of equations and therefore must be detected during simulation or may be explicitly denoted, as with a “break” statement denoting an expected discontinuity. For example, the model of a digital to analog converter commonly has such instantaneous discontinuities explicitly corresponding to changes in the digital value which is to be converted by the design into an analog value.
Behavioral, mixed-signal modeling languages, such as VHDL-AMS and Verilog-AMS, interleave or alternate simulation of analog and digital design partitions, increasing the opportunity for discontinuities between quantity values at two successive points in time. Digital values may be referenced in an analog partition by direct reference (such as VHDL-AMS) or by explicit interface mechanisms (such as Verilog-AMS). Analog quantities may be referenced in a digital partition directly, via threshold language mechanisms (such as VHDL-AMS) or via more complex interface mechanisms (such as Verilog-AMS).
Although common mixed signal modeling languages provide a wide variety of lexical and syntactic abbreviations which expand during analysis into equivalent sets of equation systems or sequential, imperative processes, the case of physically distributed terminals represent a very important exception. Modeling detail required to accurately represent such constructs depends critically on the operating frequency and other context generally only known during simulation. For example, accurate models of a transmission line expand at low frequency from a lumped parameter to a complex distributed parameter model at higher operating frequencies. In a like manner, an antenna's radiation pattern expands from a trivial, open-circuit static model at DC to a complex finite element model within interactions described by Maxwell's equations and continuity at more interesting frequencies.
From the standpoint of modeling practicality and accuracy, it is very useful for a design team to employ an incremental evolution of partition modeling detail, based on the design and thus simulation's actual operating domain, from a digital view, through an analog lumped parameter component model view, through a distributed parameter component model view, into a full-wave model view. Knowledge of the changing implementation internal to the component is then primarily modeled by a technology specialist associated with the design effort. Such a technology encapsulation and encapsulated continuity of views is not found in prior art. Anticipating this innovative modeling language step, we will thus consider the definition of analog partitions to embrace components of the partition which are lumped, distributed or full-wave in detail without loss of generality.
While representational languages and simulators exist to capture and simulate high-frequency phenomena, simulation delivers greater utility to a designer when high-frequency phenomena (lumped, analog and full-wave views) are transparently, selectively and semi-automatically conditionally introduced into the design representation in which the remainder of the system has been represented, using languages such as VHDL, VHDL-AMS, Verilog and Verilog-AMS. VHDL already provides a descriptive language mechanism by which physical phenomena such digital phenomena as tri-state and open-collector/emitter interconnect technology may be semi-transparently introduced into simulation while being ignored during uses such as the synthesis of hardware. The mechanisms are known as “resolution” functions.
VHDL resolution functions for digital interconnects, well-known prior art, may be associated with an existing type to form a new, resolved, subtype. The new, resolved subtype may then be used to define a “resolved signal”. At a specific point in time, the signal may appear on the left hand side (assignment target) of digital equations. After all assignments have taken place at each identifiable point in time at which any equations assign to the specific resolved signal, the resolution function originally associated with the signals subtype conceptually executes. Execution of this resolution function takes specific assigned values to the signal as inputs and returns a resolved value representing the tri-state, open-collector or other resolution behavior. The array of inputs and resolution function return value may either be an array of scalar types resolved to a scalar type or may hierarchically resolve a composite type consisting of zero or more composite scalar types.
The number of distinct inputs to a resolution function may not be known until after a system begins simulation. Some inputs to a resolution function may not actually be assigned at all or may not be assigned during a specific period of time. Conversely, during simulation additional drivers may be added which assign to a signal. Addition may occur as a result of executing the mixed signal design representation or more commonly through execution of a programming language fragment introduced through a programming language interface (PLI) to the system representation. In the prior art, code generated to perform simulation must accommodate the worst case resolution context and thus is less efficient than if code was generated for the actual number of active inputs to the resolution functions. Commonly resolved signals are driven by an expression's left hand side (or functionally equivalent left hand sides within a process) via the process equivalent's driver. Often the resolution function call for such signals may be eliminated or significantly simplified, for example if there is only one driver, thus improving performance.
During elaboration of a design hierarchy, the worst case number of drivers to a signal will be known in the absence of programming language interface calls creating a new driver. During a particular instant of simulation time, the exact number of drivers will be known. Unfortunately in the prior art, code implementing the resolution is commonly fixed prior to elaboration or at best prior to simulation. Thus the code implementing resolution embodies efficiencies associated with the more general case rather than the actual use. In the average case, this flexibility slows simulation.
Most analog design partitions of practical interest are non-linear. Non-linear systems include terms within their system of equations which depend on quantities or expressions involving quantities taken to powers other than one. For example, a non-linear component model may depend on the square of the voltage across a pair of terminals. Systems comprising non-linear components are computationally more complex to simulate and thus slower than linear system simulations.
Thus without loss of generality, in the following we may consider designs to be modeled using zero or more analog partitions and zero or more digital partitions. Each partition may refer to digital objects (such as signals or shared variables), analog objects (such as quantities or terminals) or values derived from these objects. Generally analog partitions and full wave partitions (subset of analog partitions) set the value of analog objects. Digital partitions set the value of digital objects. Sets of equation systems, of which one is identifiably active at any instant in time, represent behavior of each analog partition. Sets of concurrent processes, each conceptually having a sequential and imperative behavior, represent behavior of each digital partition. So as to focus on the innovations offered herein, the following will focus on this generalized representation of the design's model without implying exclusion of various equivalent design representations.
The set of all objects (analog and digital) referenced by a partition forms an operating space, such as the example shown in FIG. 2 . The domain of values which a given object may assume (based on its subtype) forms an axis of the operating space (such as 50 , 51 or 52 in FIG. 2 ). A partition's operating space has one dimension for each scalar element of each object. The three dimensions shown in the example of FIG. 2 correspond to two analog quantities A ( 50 ) and B ( 51 ) and open digital object, perhaps a signal ( 52 ).
Each dimension of the partition's operating space may be divided. When combined with divisions of other dimensions, this forms a subspace of the operating space or an operating context (by which it will be subsequently known). Operating points contained within a single context have closely related values.
During intervals time during simulation of a design's behavior, the observed object values can be contained within an operating context. Within the operating context, the non-linear system of characteristic equations can be approximated by a linear model. Techniques for deriving such approximations, known as “linearization” techniques, are well-known in the literature. At any point in a simulation, the analog partition is operating in a single, identifiable operating context with a corresponding linearization of an equation system (currently) representing the analog partition's behavioral model.
For the models of most designs, over time the analog partition will evolve during simulation through multiple operating contexts, corresponding to multiple linearizations of equation system(s). However as simulation continues, the total set of operating contexts being traversed typically develops a working set of operating contexts which encountered repeatedly, generally to the exclusion of new operating contexts.
Prior art commonly transforms equation systems, prior to the onset of simulation, into various implementations relating across and through quantity vectors by a sparse matrix. A sparse matrix implementation takes advantage of many zero-valued “conductance” matrix values to achieve substantially more compact representations than the square of the array dimensions would imply. Prior art teaches a variety of transformations on the sparse matrix representations which reduce the magnitude of off-diagonal elements (toward zero) and thus accelerate simulation. However for designs of practical interest, the off-diagonal elements of the conductance matrix are seldom all zero.
During simulation, software commonly known as an “analog-solver” iterates through an interpretation of the sparse matrix so as to identify across and through quantity values immediately consistent with the system of equations compiled into the sparse matrix formulation (and thus representing the analog partition's immediate model behavior). Integration and differentiation techniques for handling equation terms which are the time differential (such as an inductor model) or time integral of quantities (such as a capacitor model) are a well-documented aspect of the prior art.
Numerous techniques for approximating equivalence between left and right hand sides of a transformed characteristic equation by adjusting quantity values are another well-documented aspect of the prior art central to implementation of an analog solver. If transformed sides of a characteristic equation were required to match exactly at the end of each successful analog solver cycle, many simulations would fail to converge and thus terminate after reaching an iteration or time limit. At the possible expense of long-term simulation accuracy, most analog and mixed-signal modeling languages and simulators accept a tolerance within which left and right hand sides are considered to match.
In prior art, models implemented in programming languages, such as C or Fortran, are commonly compiled before execution. Compilation results in compiled assembly or binary machine code common to all operating points and across all discontinuities. Compiled code may refer to multiple lookup tables representing the relationship between across and through quantities. However in prior art, compilation completes before simulation begins and thus cannot benefit from any contextual information know only during and after simulation, thus decreasing simulation performance.
Prior art also teaches techniques by which the current and voltage relationships within an operating context may be approximated by one or more tables. Such tables are constructed prior to simulation, then interpreted by machine instructions common to more than one operating context. Significantly, the innovations taught here allow optimization of the machine instruction sequences for a specific operating context.
If an analog solver is split across more than one processor (multiprocessor), the lack of contextual information encountered when practicing prior art has an even more severe performance impact than with a single processor. In a sparse matrix implementation, it is difficult or impossible to predict and schedule reference patterns so as to effectively schedule multiple processors or functional units to execution distinct portions of the same analog solver, to avoid cache to cache conflicts or to avoid locking of data structures (and thus performance degradation due to contention). As a result, speed-ups in the analog solver resulting from additional processors are generally accepted in the prior art as significantly below the idealized (and desirable) linear speed-up curve. For example, with the prior art, four processors execute an analog simulation at significantly slower than one quarter the rate of a single processor.
Electronically re-configurable logic devices, such as field programmable gate arrays (FPGAs), are often used to accelerate simulation designs at digital levels of abstraction, either in the form of emulators or simulation accelerators. The parallelism available inside of such devices results in substantial speedups relative sequential simulation execution through the execution pipeline of a single processor or a modest number of processors within a multiprocessor. Prior art does not teach any efficient means for utilizing the parallelism of electronically re-configurable logic devices for the simulation of analog, mixed-signal or full-wave abstraction levels.
At least one electronically re-configurable logic device has been fabricated with electronically re-configurable analog modules, such as amplifiers and filters. From the standpoint of simulation use, this device substantially lacks accuracy, noise-immunity, dynamic range, capacity and flexibility required for effective simulation of analog, mixed-signal or full-wave abstractions. Fundamentally it represents quantity values as actual analog values rather than as their sampled digital equivalents.
For ease of reading following current common use, the following will refer to FPGA devices although the references are understood to generalize to the broader class of electronically re-configurable logic devices (no matter what their architecture or market positioning). The references to FPGA are understood to embrace electronically re-configurable interconnects, memory arrays and various configurations of logic cells from fully programmable gates to large logic blocks where only selective interconnect and functionality aspects are electronically programmable.
Large designs, especially when modeled at analog, mixed-signal or full-wave levels of abstraction may readily become too large to fit on a single electronically re-configurable logic device or FPGA, requiring partitioning of a single design across more than one such device to efficiently perform simulation. As device density increases the number of logic gates and storage elements inside FPGA, the number of gates and elements on the device increases as the square whereas the number of pins or ports available to communicate on and off the device increase linearly. As a result, pins on and off the device become an increasingly limiting resource.
Efforts to form and bond pads away from the FPGA's periphery help to reduce this problem at the cost of internal logic and memory functionality. However, off-chip interconnects are still more power-intensive than on-chip interconnects, resulting in an increasing incentive to reduce the number of off-chip interconnects required to fulfill a given functionality.
Prior art either maps digital signals directly to pins and traces connecting the pins of various devices or time-multiplexes several signals on the same pins. Commonly the value of a quantity at one time step numerically differs relatively little from the value at the next time step. This is especially true for analog, mixed-signal and full-wave quantities, however the same observation can be made to a lesser degree in the context of digital values. Inefficient use of scarce interconnect resources, as prior art does, results in less effective use of electronically re-configurable logic devices, requiring more devices to partition a design. Dividing a design into additional devices increases cost and slows simulation.
Although the pins of electronically re-configurable logic devices are becoming a limiting factor to effective design size and cost, it is also difficult to implement many arithmetic operators with both high precision and wide dynamic range on a given electronically re-configurable logic array. Frequently designs must accommodate the worst-case precision and range requirements in an operating specification. If the configured device in operation operates outside this specification, overflow, underflow or loss of precision may lead deviations between behavior of a design model and a realized design, ultimately having the potential to cause design failure.
Quantity values in the prior art rely almost exclusively on floating point representations (consisting of a mantissa, implied base and exponent). Since general purpose processors efficiently execute a small number of numeric representations (corresponding to those defined into the processor's instruction set and realization), use of floating point representations are the easiest way to gain increased range. However use of floating point representations has several significant drawbacks, especially in the context of FPGA implementations designed for maximum performance. Even serial implementations of floating point operators are significantly larger and more complex than integer representations, putting FPGA logic at a premium. Normalization and related floating point operations inherently require more time to execute than equivalent integer implementations. Numerical precision is much more difficult to formulate than for integer operations since precision changes as floating point values deviate from a central value, typically 1.0. Finally the flexibility of FPGA logic enables fabrication of almost arbitrary precision integer arithmetic logic, providing alternatives to floating point representation in order to increase usable numerical dynamic range.
Failure associated with overflow, underflow or loss of precision may only be avoided in the prior art through over-design of the specifications or careful and tedious exception handling. Given finite implementation resources, over-design must come at the expense of both decreased functionality and increased power consumption. Over-design throughout a design generally results in a significant decrease to both the design's user functionality and power, yet it only delays the potential for failure due to overflow, underflow or loss of precision.
Designs typically embody existing intellectual property, such as cell libraries or even entire microprocessors. For business reasons, owners of this intellectual property want to export models representing the behavior of these components while restricting the level of implementation or realization detail exposed. Previously such models either used code compiled into assembly language, such as the Synopsys Smart Model or inserted actual devices into the simulation, as in the Logic Modeling Real Chip product.
Compiling component models into an assembly code format is only useful when executing simulation on a general purpose processor for which a compiled representation exists. Such models must be decrypted before simulation begins, leading to the potential for disassembly of the model's assembly code representation and thus compromise of the owner's intellectual property. As an alternative to an assembly code model, prior art describes how to insert actual devices into a simulation.
Inserting actual devices requires an expensive test set in order to operate the isolated device with a suitable speed, timing, power and cooling. Prior art capable of introducing an actual device into a simulation do not address simulation at the analog, mixed-signal or full-wave abstraction levels. Prior art implies substantial time and therefore cost resulting from the need to maintain the chip's specific operating environment. These are important disadvantages to wide-spread use.
Development of accurate analog, mixed-signal, and full-wave models of a design or design component is time consuming and error-prone. In the prior art, such models tend to evolve manually, with ever-increasing complexity attempting to adapt existing models to new requirements or operating conditions. Even the evolution of such models requires specialized designer skill, a skill which is often in short supply.
Accurate analog, mixed-signal and full-wave models are essential to the synthesis of new analog designs, the retro-fit of existing designs and the modeling of complex designs with one or more missing component models. The prior art offers techniques for manually fitting a model around characterization of operating specifications, however both the gathering of such specifications and the effective fitting of data to achieve a new model is a slow, manual process in the prior art. The cost and time expenditure implicit in such a manual process are a significant disadvantage of the prior art.
Effective comparison techniques are a significant intermediate step in enabling the effective, semiautomatic generation of analog, mixed-signal and full wave component models. Such comparison provides an essential calibration in the process of semiautomatically developing a new analog, mixed-signal or full-wave model corresponding to an existing simulation or actual device. The most powerful prior art available to compare analog, mixed-signal or full-wave models relies on exhaustive simulation of a reference and comparison model under a wide variety of operating conditions.
Comparison of analog, mixed-signal or full-wave models via exhaustive simulation is both time consuming and ultimately fragile. Since it is not possible to simulate all operating modes in a bounded time, the risk of missing a key difference in the behavior of reference and comparison model must remain. Even the time required to conduct enough simulation to approach a given confidence level increases beyond practical limits as the complexity of devices being compared increases.
Textual comparisons of reference and comparison models are especially fragile. Models with closely related lexical and syntactic constructs may exhibit radically different behaviors. For example, a function which approaches positive infinity from one side of a critical value and negative infinity on the other side of the critical value will be extremely sensitive to behavior around this critical value. Conversely a trignometric function and its Taylor expansion can be lexically and syntactically very different, yet yield acceptably equivalent values over an interesting operating range. Therefore prior art based on textual comparison, such as the common available textual differencing utilities are of little practical value in the problem of analog, mixed-signal or full-wave model comparison.
SUMMARY OF THE INVENTION
An incremental compilation and execution method is taught for the optimized simulation of analog and mixed-signal designs using programmable processors. Prior art utilizes software to implement an analog solver by interpreting a design-specific data structure valid for all Operating Contexts. The innovative method taught herein implements a more efficient analog solver by inserting code fragments compiled for a specific Operating Context into the simulation cycle.
A code fragment for each possible Operating Context may be compiled prior to simulation. Since the num-ber of possible Operating Contexts can be large and comparatively few Operating Contexts will actually be encountered during most simulations, a further method for incrementally compiling analog solver code fragments on demand is taught. Once compiled, such code fragments may be retained for subsequent re-use (cached) during the same or subsequent simulation runs.
The method, illustrated in FIG. 8 , consists of four primary steps applied to each Analog Partition:
1. Computation of the current Operating Context ( 350 )
2. Map the Operating Context to a Context-Specific Analog Solver ( 351 , 356 , 357 , 354 , 355 , 358 )
3. Evaluate Context-Specific Analog Solver, updating Analog Object Values and values derived from Ana-log Object Values ( 352 )
4. Compare left and right hand side of equations in Analog Partition against applicable tolerances. If not above tolerance, continue with the Digital Simulation Cycle ( 359 ) and then Step 1. If above tolerance, either return directly to Step 1 or exit the loop (Steps 1 to 4 above) at a Breakpoint.
FIG. 7 illustrates a means of computing the Operating Context from the current values of objects refer-enced from the Analog Partition. From each value, the range of values needed to distinguish an Operating Context (see FIG. 2 ) in which referenced objects have a sufficiently linear relationship are extracted and form a Key ( 309 ). The Key ( 309 ) may then be used to identify a existing Context-Specific Analog Solver or create an appropriate Context-Specific Analog Solver from the Elaborated Representation (see FIG. 6 , 4 ) via the Incremental Compiler/Assembler/Loader (see FIG. 6 , 5 ).
Context-Specific Analog Solvers embody numerical solver algorithms known from the prior art including linearization of Algebraic Equations, Ordinary Differential Equations and Partial Differential Equations about an operating point within the Operating Context, numerical algorithms to update Analog Object Val-ues based on direct or iterative solution (such as Newton/Raphson iteration) and numerical algorithms to integrate or differentiate Analog Objects. As shown in FIG. 11 , Context-Specific Analog Solvers may be compiled into General Purpose Processor Instructions (such as 508 and 509 ) which may direct reference to Object Values via one of the many instruction set effective addressing modes well-known to assembly language programmers and computer designers.
Common Breakpoints include failure to approach tolerances during successive simulation cycles (failure to converge), failure to converge after a specified number of analog solver cycles at the same time point, reach-ing a specific time point, attaining specific object values or matching a specific data access pattern. Other sources of breakpoints are commonly known from the simulator or program debugging literature and are known to those skilled in the art of programming language interface or debugger design.
FIG. 6 illustrates the set of software components typically employed to implement this method. A Source Code Analyzer ( 1 ) compiles textual or graphical models of a design to a Post-Analysis Representa-tion ( 2 ). A Static Elaborator and Inliner ( 3 ) compiles the Post-Analysis Representation ( 2 ) into an Elabo-rated Representation ( 4 ). An Incremental Compiler/Assembler/Loader ( 5 ) then generates General Purpose Processor Instructions ( 508 and 509 ) used to implement Context-Specific Analog Solvers ( 7 ), Exe-cutable Digital Partitions ( 8 ) and Embedded Scheduling Executables ( 1000 of FIG. 24 ) needed to sched-ule the execution of Context-Specific Analog Solvers ( 7 ) and Executable Digital Partitions ( 8 ).
An innovative method is taught for generation of either structural or behavioral mixed-signal models using iterative probing of an existing model embedded in a simulation or an existing device embedded in a test set suitable for applying stimuli and retrieving the response. The technique is useful in the context of analog and mixed-signal simulation as a means to generate suitable textual models from other sources (avoiding the need to co-simulate with other simulators or insert actual devices into a running simulation), as a means of generating more abstract (and thus faster models) as shown in FIG. 9 ( 453 ) or for the semi-automatic synthesis of analog components matching a behavioral specification.
FIG. 19 shows the major steps required to practice the method. A Template Library ( 868 ) contains an incrementally extended collection of parameterized component templates in an intermediate format (such as FTL Systems' AIRE/CE Internal Intermediate Representation). A Template Selection Step ( 850 ), Equation Fitting ( 852 ) and Parameter Fitting Step ( 854 ) select and refine templates until Model Source Code Genera-tion ( 856 ) produces a Textual Representation as Source Code or Intermediate Format suitable for direct compilation into a simulation.
At each of the three steps in the selection and refinement process (Template Selection, Equation Fitting and Parameter Fitting), comparison of the evolving models and either Existing Component Simulation ( 853 ) or Actual Device on Interactive Test Set ( 855 ) produce an improving match between the observed behavior of reference and comparison models. The Test Model Generation and Analysis component ( 851 ) sets up an actual device or simulation for a particular Operating Context, then converse a response into a parametric equation form suitable for Template Selection, Equation Fitting and Parameter Fitting.
FIG. 20 provides additional detail on the Template Library ( 868 ) and Template Selection ( 852 ). The Template Selection ( 850 ) consists of three steps:
1. Matching to a template based on the number of ports and type, establishing the entity ( 904 )
2. Matching based on a Switch-Level Topology
3. Matching based on Equivalent Canonical Equation Forms ( 906 )
Template match ( 901 ) produces an incrementally refined match to Template Selection criteria by either generating a template on-the-fly to meet the specification, via the Template Generator ( 900 ) or via reference to a previously generated pair of behavioral and structural models. Behavioral models use an Equation System to define the behavior (potentially including conditional constructs and discontinuities between Operating Contexts) as well as a structural equivalent.
An innovative method is disclosed for the Semi-Automatic Behavioral Comparison of Analog and Mixed-Signal Models. The comparison method reduces the need for exhaustive simulation and comparison of sim-ulation results taught in the prior art (and in general practice). Such comparison techniques are particularly useful for practicing “Method for Semi-Automatic Generation of Mixed Signal Models via Behavioral Prob-ing” taught in a concurrent patent application.
FIG. 22 illustrates the comparison technique. Reference and comparison models are analyzed into a Post-Analysis Intermediate Representation ( 900 and 901 ), Elaborated and Statically In-lined into a Post-Elaboration Form ( 902 and 903 ), then converted into a canonical form suitable for graph matching ( 904 and 905 ). Comparison methods first attempt to build a correspondence between the two graphs ( 906 ). If a cor-respondence can be made, numerical values assigned to nodes and branch values are compared.
If a correspondence between nodes and branches in the Reference and Comparison Model can be made, an innovative graphical representation is useful, as shown in FIG. 23 . Icons represent hierarchical struc-ture, objects and equations. Each icon is divided such that portions of the icon may be colored, shaded or otherwise differentiated in appearance. Comparison of the two appearances of each icon provide a visual representation of how closely the reference and comparison structure, objects or equations match by com-paring the appearance of distinct icon regions. The match may be either a time-average or may vary dynamically to reflect the immediate difference in value. Structural icons denote the aggregate value of their component structure, objects and equations.
BRIEF DESCRIPTION OF THE FIGURES
FIG. 1 is a representation of partitioned, mixed signal design illustrating mixed signal objects such as terminals, branches, signals, shared variables, across quantities and through quantities.
FIG. 2 illustrates that instantaneous values of objects referenced within a logical analog solver partition correspond to a point in the partition's value space. The value space may be divided up into operating contexts. Each context contains those points which may be related by the same, linearized analog solver.
FIG. 3 illustrates that lumped parameter terminals may be incrementally expanded into distributed parameter representations of the same terminals to reflect requirements for greater behavioral detail.
FIG. 4 illustrates that incremental terminal expansion may be achieved by associating a distribution procedures with terminals. Technologist may then supply suitable distribution procedures representing specific kinds of interconnect and parasitic behavior.
FIG. 5 illustrates that during simulation, implementation of resolution functions and distribution procedures may be incrementally recompiled to more efficiently reflect specific driving conditions, abstractions of physical properties, operating frequencies, external noise and other factors altering operation of the design.
FIG. 6 illustrates the overall steps required for optimized simulation of a design using innovations taught herein.
FIG. 7 illustrates the detail of incremental compilation and execution functionality for optimized simulation using innovations taught herein.
FIG. 8 illustrates the modification of simulation cycle implementation to accommodate optimization.
FIG. 9 illustrates the detail of operating point key generation within analog solver cache.
FIG. 10 illustrates the management and allocation of simulation state.
FIG. 11 illustrations the direct simulation state reference from addressing fields of machine instruction.
FIG. 12 illustrates the logical architecture of a single simulation accelerator card
FIG. 13 illustrates the peripheral for insertion of one or more embedded component models into simulation.
FIG. 14 illustrates the analog solver mapping directly onto electronically re-configurable logic array.
FIG. 15 illustrates the analog solver mapping directly into electronically re-configurable logic array with embedded memory.
FIG. 16 illustrates the digital mapping directly onto electronically re-configurable logic array using delta representation of signals interfacing with another electronically re-configurable logic array.
FIG. 17 illustrates the full wave solver mapping directly onto electronically re-configurable logic array using delta representation of value propagation with another electronically re-configurable logic array.
FIG. 18 illustrates efficiently extending arithmetic range and precision using incremental recompilation on under-flow, overflow or loss of precision.
FIG. 19 illustrates the steps in the method for semi-automated extraction of model from behavioral simulation.
FIG. 20 illustrates the steps in the method of semi-automated extraction of model from actual device operation.
FIG. 21 illustrates an interactive representation of design comparison or model generation using graphical user interface.
FIG. 22 illustrates the steps in the method for formal comparison of two mixed signal models.
FIG. 23 illustrates the embedded scheduling of mixed signal designs for efficient simulation on multiple processors.
DETAILED DESCRIPTION OF PREFERRED EMBODIMENTS
In order to accelerate the simulation of designs containing digital, analog, mixed-signal or full-wave components, inter-related innovations in modeling languages, computer software for incremental compilation, computer software for simulation and hardware apparatus for simulation acceleration are useful. This sec-tion teaches the preferred embodiment of such inter-related innovations.
In lumped parameter modeling languages, terminals denote a point at which contributions from two or more branches converge, such as the lumped parameter terminal ( 202 ) at the top of FIG. 3 . Analogous to the introduction of resolution functions to associate a procedural code fragment with the technology implementing an interconnect (modeled as a terminal), the preferred embodiment allows a technologist to encapsulate a more detailed interconnect model (consisting of quantities and equation systems) as an implementation of the interconnect behavior.
By encapsulating the expanded interconnect behavior, technologists may replace the lumped parameter with an implied array of terminals (such as a transmission line) or a finite element lattice which can ultimately serve as the data structure for finite element implementation of a full-wave model (such as the model parasitic coupling within an electronics package or even an antenna acting as an element within a larger system model). FIG. 3 shows a comparatively simple expansion from a single terminal to an array of implied terminals. Connections made by the designer to the original terminal ( 202 ) may either be associated by default (as with resolution functions) or by explicit reference to elements of the terminal array (such as 202 and 206 ). Those skilled in the art of hardware description language design will readily generalize from the implied terminal array ( 204 ) into a two or three dimensional lattice suitable for finite element implementation of a full-wave equation solver.
FIG. 4 illustrates the corresponding fragment within an extended VHDL-AMS syntax. Lines 210 and 211 declare a very conventional definition of current and voltage. Lines 212 and 213 define a comparatively conventional nature and unconstrained array of natures. Innovatively Line 214 defines a procedure (or equivalently this could be a Verilog task) implementing the behavior of a distributed transmission line. Innovatively this procedure may then be used in the formation of a distributed subnature analogous to the association of a function and subtype to implement a digital resolution function. The subnature may then serve as the nature of a terminal declaration, as in Line 219 .
Parameters to a distribution function must be a terminal interface declaration of an unconstrained nature followed by zero or more interface declarations used to customize the distribution procedure's behavior for a specific terminal declaration. For example, the constant or variable interface declarations may represent a specific dielectric constant, characteristic impedance or even time-varying property such as the local temperature within the system model of a micro-electronic machine. Subsequent signal, shared variable or other terminal declarations may provide for modeling explicit induced noise or parasitic couplings.
Values may be associated with the distribution function's constant or variable parameters at the point where the nature is associated with a specific terminal declaration. For languages which allow terminals of unconstrained type, distribution function parameters and constraints must be syntactically distinguished. One means for distinguishing the distribution function parameters and constraints takes advantage of the need to provide a constraint for each unconstrained dimension of the nature at the point where the nature is associated with a terminal. Therefore the constraints, if any, may appear as a parenthetic list. Distribution parameter associations, if any, may then appear as a subsequent parenthetic list. Other means of synthactically denoting constraints and parameter values are possible and are commonly known to language designers.
Quantities then refer to terminals (and thus instances of distributed natures) to form branch quantities and thus characteristic, simultaneous or constraint equations representing the design's behavior. In the prior art, terminals are either scalars or composites ultimately defined in terms of scalars. Each scalar nature has an across and through type relative to an explicit or implied reference terminal. The reference terminal commonly represents a localized or global “ground”.
In the previous case of a resolution function associated with a signal, the resolution function's input dimensionality is imposed external to the resolution function by the set of drivers immediately contributing to the resolved signal's value. As an innovative step, the terminal subnature's distribution function must internally impose a constraint on a specific, unconstrained parameter based on the terminal's immediate modeling requirements chosen by the technologist who created the distribution function. To the system designer using the terminal with a nature having a distribution function, the terminal appears to be a lumped parameter with all the modeling ease of use commonly associated with a lumped parameter model.
Internal to the distribution procedure body, the technologist controls the dynamic degree of distribution, the modeling mechanism and even the parasitic couplings not explicitly denoted by interface associations at the point where the distributed nature was associated with the terminal through definition of the procedure's body. This degree of flexibility cleanly and orthogonally separates language design from modeling methodology, facilitating the independent efforts of mixed-signal system designers, technologists and tool developers. This de-coupling results in a technology-independent language design with broad applicability and thus an implementation expense spread over many application domains. Therefore it is a useful innovation.
Those skilled in the art of mixed signal language design will recognize three complications to the implementation of this innovative step. First, some mechanism must be provided to dynamically constrain the distribution procedure's dimensionality. Second, some means must be provided to dynamically associate specific elements of the terminal parameter with external contributions to quantities. Third, some means must be provided so only the modeling detail actually required is embodied in the code executed to implement the distribution procedure body.
First, various methods for constraining dimensionality of the terminal interface declaration sub-nature on each call (and thus dynamic elaboration) of the distribution procedure are known to those skilled in the art and can be employed with approximately equal ease. Most methods involve introducing a step at the point during call to the distribution procedure when the interface declaration is first elaborated, at which time arbitrary code can be executed. An immediately relevant precedent for such elaboration is found in VHDL's type conversion functions, only in this case the function called when mapping from actual to formal parameters in the association constrains the terminal nature dimension rather than transforming the value. Syntactically this may be accomplished by methods such as allowing the ‘length attribute to become an (assignable) right hand side value for VHDL. Comparable language extensions can readily be identified for other mixed signal languages, such as Verilog or Mast, by those skilled in the art.
Second, some mechanism must be provided to address the association between elements of the first terminal parameter to the distribution procedure and external quantities referencing the first terminal interface declaration. In this case VHDL's resolution functions are not of direct help. Indeterminate mapping between external signals and resolution function input elements for digital VHDL are one of the major sources of non-deterministic behavior within VHDL. Such non-determinism is generally recognized and somewhat reluctantly accepted as a compromise to achieve higher performance and language simplicity. One means of addressing both the digital resolution function parameter association problem and the more immediate need for association with the first parameter of a terminal declaration's distribution procedure is to make the unconstrained array explicit at points which refer to the terminal. For example, a terminal with a sub-nature having a distribution procedure could either be referenced with an indeterminate array type, in which case the association would be indeterminate, or via explicit array subscript expressions. For example, in the later case one end of a transmission line model might refer to terminal subscript zero whereas the opposite end would refer to terminal ‘length. Other methods for making the association and extensions to language other than VHDL will be obvious to those skilled in the art of language design.
This brings us back to the third concern for both the implementation of existing resolution functions and the innovative distribution procedures described above; performance inversely proportionate to the modeling detail required. The innovative method solving both concerns is shown in FIG. 5 . During analysis and elaboration the compiler predicts the configuration in which each signal, quantity, terminal and shared variable is predicted to operate ( 225 ). Then during code generation, the code generator implicitly inserts assertion or trap functionality to invoke the compiler if the assumed signal, quantity, terminal or shared variable configuration does not correspond to the most recently assumed configuration. Following this assertion, the compiler generates optimized code to implement the signal, quantity, terminal or shared variable based on the assumed configuration ( 226 ).
During simulation execution, general purpose processor instructions or configured logic (in an FPGA) result in a re-invocation of the compiler if the asserted signal, quantity, shared variable or terminal configuration does not actually occur ( 227 ). Iteratively the execution traps on the exception ( 230 ), potentially re-uses a cached implementation of an instruction sequence or configured logic matching the conditions actually occurring during a simulation and continues execution.
In the context of an innovative distributed terminal, the technologist may directly or indirectly include several implementations in the procedure representing interconnect functionality. If a quantity or variable rep-resenting frequency is below a threshold, the terminal may remain lumped. If the frequency exceeds the first threshold, the implementation may use a relatively coarse transmission line model. At still higher frequencies the procedure may use a full-wave model implemented using explicit finite element techniques. How-ever it is very important to note that our innovation simply supplies a very flexible and efficient method for a skilled technologist to implement many different kinds of condition-specific interconnect models; our innovation does not embody any specifics of device or interconnect technology and thus is extremely general and flexible. As with resolution functions, the innovation facilitates a decomposition of skill between the overall designer and the interconnect or device technologist.
FIG. 6 illustrates the overall software components within the preferred embodiment. Components 1 through 5 are processor instructions configuring the persistent storage system, memory and instruction cache(s) of a uniprocessor, shared memory multiprocessor or cluster of such processors (software). Components 6 , 7 , 8 , and 31 may be implemented in software or electronically re-configurable logic devices (often known as FPGA).
The Source Code Analyzer ( 1 ) is a means of incrementally translating from graphical or textual models of a digital, analog or mixed signal design into a post-analysis representation ( 2 ). One common example of such an analyzer is FTL Systems' Tauri source code analyzer translating into FTL Systems' AIRE/CE Internal Intermediate Representation (IIR). The Post-Analysis Representation ( 2 ) supplies representation elements such as literals, identifiers, strings and declarations to both directly to the Incremental Compiler/Assembler/Loader ( 5 ) and to the Static Elaborator and Inliner ( 3 ).
At designer-defined events, known as Design Epochs, the Post-Analysis Representation ( 2 ) triggers ( 11 ) the Static Elaborator and Inliner ( 3 ) which subsets of the Post-Analysis Representation ( 2 ) have changed since the start of compilation or the last Design Epoch. The Static Elaborator and Inliner ( 3 ) then incrementally queries the Post-Analysis Representation ( 2 ) to generate or update Elaborated Representations ( 4 ) through application of rewriting rules defined by the modeling language(s) in use or by conventional compiler optimizations such as subprogram inlining, loop unrolling, constant propagation and related transformations.
The Elaborated Representation ( 4 ) consists of constructs denoting digital objects, digital partitions, analog objects, analog partitions and full-wave partitions along with back-annotations to the Post-Analysis Representation ( 2 ) and eventually textual source code. Back-annotations are used for interactions with the designer such as source level debug, profiling, timing annotation and related functions.
As changes to an Elaborated Model Representation ( 4 ) resulting from previous Design Epoch(s) are reflected in the Elaborated Representation ( 4 ), the Incremental Compiler/Assembler/Loader ( 5 ) may begin compilation into an executable form, ultimately resulting in Executable Digital Partitions ( 8 ) and/or Executable Analog Partitions ( 7 ). Compilation cycles by the Incremental Compiler/Assembler/Loader ( 5 ) may ultimately be triggered by the Designer (resulting from design changes or interactive debug/profiling) or by the executing digital and/or analog simulation. The latter trigger is an innovative step.
The Incremental Compiler/Assembler/Loader ( 5 ) includes the following compiler functionality:
means of maintaining storage allocation for digital partitions, analog partitions, subprogram call stacks, stimuli, event traces and dynamically allocated storage means of maintaining and optimizing processor instructions synchronizing partitions, implementing digital partitions and implementing analog partitions means of maintaining and optimizing re-configurable logic code synchronizing partitions, implementing digital partitions and implementing analog partitions means of loading assembly code and logic for execution
While storage allocation, processor instruction generation, re-configurable logic generation and loading draw substantially from prior art in the compiler and synthesis literature, the present invention adds new and innovative mechanisms which enable analog, mixed-signal and full wave simulation as well as accelerating digital simulation.
Executable Digital Partitions ( 8 ), Executable Analog Partitions ( 9 ) or full-wave partitions (not shown) either use Embedded Scheduling techniques first taught by the present inventor in 1991 or an innovative generalization of these techniques to multiprocessor and re-configurable logic implementations. In essence, Embedded Scheduling combines processor instructions and re-configurable logic implementing models of design components with processor instructions and re-configurable logic implementing event transmission and execution scheduling.
Incremental compilation operations resulting in changes to Executable Digital Partitions ( 8 ), Executable Analog Partitions ( 7 ) or Executable Full-Wave Partitions (not shown) are often transient. Common examples of such changes include breakpoint insertion, callback insertion, optimization of digital resolution function implementations, linearizations of an equation system at an Operating Context and substitution of various interconnect components within an analog partition. Processor instruction sequences implement these changes by changing the target of instructions such as jump, conditional jump, branch, conditional branch, call and return or substituting an existing instruction by one of these jump, branch, call or return instructions. Re-configurable logic implements these changes by re-configuring one or more logic cells or altering interconnect configurations.
In order to accelerate restoration of previous instruction or logic functionality, previous instruction fragments or logic fragments may optionally be retained in a hardware or software cache. In order to accelerate fragment lookup and subsequent incorporation in an executable. Digital, analog and full-wave fragments may optionally be cached in separate caches such as the Cached Digital Partition Fragments ( 31 ) or the Cached Analog Solver Fragments ( 6 ). Requests for potentially cached fragments may be routed directly to the compiler, as in paths ( 23 / 25 ), or optionally requests may be routed via the corresponding cache ( 18 / 26 ), flowing on to the compiler in the case of a cache miss ( 19 / 28 ). The compiler may in turn supply the incrementally compiled fragment directly to the executable ( 15 / 16 ) for immediate loading or optionally via the cache ( 20 / 21 or 29 / 30 ).
If the cache is involved in the path from compiler to executable, the relevant cache lookup process is shown in FIG. 7 . Bit fields which define a partition's Operating Context from objects, their subtypes and sub-natures are extracted from the current object values to form a Cache Key ( 309 ). Bit fields which define a particular point within an Operating Context are not used in the key formation. The resulting key may be used directly for Cache Lookup ( 310 ) or indirectly by computing an additional Hash function ( 311 ). Due to the large number of bits often involved in a key, some means of lookup acceleration, such as a hash, is often a practical requirement. Lookup then uses both the key ( 310 ) and its hash ( 312 ) for lookup. A wide variety of techniques for computing hash functions and implementing a cache lookup are known to those skilled in the art.
The analog solver simulation cycle is shown in FIG. 8 . Conceptually the same sequence of steps occurs when executing using a sequence of instructions or re-configurable logic; the primary differences are in the implementation of Incremental Compilation ( 354 ) and Evaluation ( 352 ). At start ( 360 ) the compiler loads initial values, instructions and re-configurable logic configurations. Depending on a partition's executable implementation, instructions or logic implement a means of Operating Context Determination (as discussed above in the context of FIG. 7 ).
Using well-known software or hardware caching techniques, Operating Context Match Logic ( 351 ) deter-mines if an existing instruction sequence or logic configuration is already available to implement the partition's behavior in the partition's current operating context. The Operating Context Match Logic ( 351 ) will produce one of three outcomes: the partition's current instruction sequence or logic configuration is a suit-able implementation of the partition's behavior in the operating context ( 363 leading to 356 ), a suitable implementation is available in the cache ( 364 leading to 357 ) or a suitable instruction sequence must be compiled ( 365 leading to 354 ), loaded into the cache ( 370 leading to 355 ) and loaded for execution ( 371 leading to 358 ).
Once a current analog solver is loaded to implement each analog partition behavior at its Operating Context ( 352 ), the analog solver executes to identify new values to associated with analog objects. In the case of an analog partition's solver, the solver updates quantity values, evaluates left and right hand sides of each com-piled equation and compares the difference against the acceptable tolerance defined by the applicable language reference manual ( 353 ). If all compiled equations in the analog partition are less than a tolerance away from equality, the Digital Simulation Cycle ( 359 ) runs with an implementation comparable to the one shown in FIG. 8 , otherwise the updated quantity values lead to a new Operating Context Determination ( 374 leading to 350 ) and the analog solver cycle begins again.
A wide variety of numerical techniques for evaluating an analog solver are documented in the literature and well known to those skilled in the art (such as Newton-Raphson iteration). Virtually any of these techniques can be applied to the innovative approach taught here. However by using an instruction sequence or logic configuration which implements an analog solver specific for an Operating Context, linearizing within this context and then generating instructions or logic it is possible to innovatively avoid the need to either use a large but sparse matrix or employ interpretation techniques for traversing a sparse matrix data structure. Since the exact set of operators required and their data dependencies are known at the time code is compiled, all of the operations may be efficiently, pseudo-statically scheduled on multiple processors and/or re-configurable logic and immediate offsets into the memory layout may be incorporated directly in instructions or logic.
FIG. 9 details the means of Incremental Compilation (used at step 354 in FIG. 8 or the equivalent step during the digital simulation cycle ( 359 )). Post-Analysis Design Representations ( 2 ), changes in a partition's Operating Context ( 27 ) and Design Epochs in the Elaborated Representation ( 4 ) all result updates maintaining a revised logical view of digital or analog partitions. Such partitions are logical in the sense that compilation may further schedule the partition for execution on multiple processors and/or logic devices or multiple logical partitions may be combined on a single processor or re-configurable logic device using Embedded Scheduling.
A distinct compilation phase, Pseudo-Static Technology Binding and Scheduling ( 451 ) maps logical partitions onto specific processor and/or re-configurable logic devices. For each logical partition, the technology binding and scheduling step estimates the processor resources (clock cycles and number of processors) and logic resources (number of logic blocks and interconnects) required to implement the logical partition. Then using well-known techniques for static scheduling, this step determines which implementations and bind-ings to specific execution hardware are most efficient in reducing the partition's execution time. Subsequent compilation steps use this schedule to choose a subsequent implementation technology ( 474 , 475 , 476 , 477 and 478 ).
Three different code generators respond directly to specific kinds of bindings to generate digital ( 454 ), analog ( 456 ) and full-wave ( 455 ) instruction sequences or logic/interconnect configurations. Alternatively either scheduled digital or analog partitions may be identified as candidates for simplification using model abstractors ( 452 and 453 ). Model abstractors which can successfully implement an abstraction generate a revised resource estimate ( 474 ) which may in turn impact a more generate technology binding and scheduling ( 475 , 476 , 477 ).
Model Abstractors replace operators, data types and components within a design with a simpler form expected to have observably equivalent behavior based on expected use. If use expectations differ from actual use during simulation, the equivalent model must be transparently replaced (via re-compilation) and the more complex implementation restored. For example, adder logic using a multi-valued logic system may be abstracted into a processor's add instruction using a two-value logic system based on the (validated) expectation that only zero and one values occur and that the adder logic is correct. A comparable analog model abstractor might replace an amplifier circuit with an equivalent behavioral model.
Digital ( 454 ), analog ( 456 ) and full-wave ( 455 ) code generators create an intermediate representation which is exported to a sequence of back-end code generation steps for an instruction set sequence ( 483 , 484 , 495 ), re-configurable logic ( 485 , 486 , 487 ) or both. Generators may emit an intermediate format such as C, EDIF or XDL suitable for an external compilation or synthesis step. Such external steps attain an equivalent end result, generally with substantially higher compilation latency.
The incremental assembly step consists of an Incremental Assemblers ( 457 ), Incremental Linker ( 458 ) and Incremental Loader ( 459 ). The Incremental Assembler ( 457 ) may convert intermediate representations ( 483 , 484 , 495 ) to binary on an expression, subprogram, partition or other granularity. The resulting code fragments may be immediately used for execution, cached or stored in a file for subsequent use. Such back-end code generation steps ( 457 , 458 , 459 ) resemble many of the steps used by an integrated compiler back-end, such as the one produced by Green Hills.
The incremental synthesis path ( 460 , 461 , 462 , 463 ) in a like fashion resembles an incremental version of a conventional behavioral synthesis process. Such a process includes logic synthesis, hardware scheduling (so as to reuse the same hardware for several instances of the operator in the model source representation), re-timing (to insure that hardware cycle, setup, hold and related timings are actually met with the logic's target technology, partition and timings), placement of logic onto specific re-configurable logic devices, re-config-urable logic cells, routing between cells and devices, bit stream generation for configuring each devices and loading for immediate execution, caching, or storage in a file for subsequent use.
Technology Binding and Scheduling ( 451 ) not only maps execution to instructions and logic, it also maps objects as well as implicit storage (such as temporaries, events and other data) into one or more memories, as shown in FIG. 10 . When objects are common to two or more physical partitions (for example when partitioning divides a logical partition between two re-configurable logic devices or between a re-configurable logic device and general purpose processor such as 552 ), storage allocation must bind the object two or more locations (only one of which is generally read/write at a specific instant in simulation time). Furthermore since memory is more efficiently copied as a large block, storage may be allocated to objects using bins which provide for block memory copies from the read/write version of one or more objects to the other, read-only copies. As the optimal layout changes over time, either memory overlays or other techniques may be adapted to minimize the time required for memory to memory copy operations.
The same processors and re-configurable logic may be used to execute more than one compiled model. For example, to accomplish fault simulation a primary model may be spawned into two or more models with specific faults. Alternatively, an abstracted model (resulting from 452 or 453 ) may be simulated in parallel with the original component to explore equivalence of the two models.
It is understood that analog solvers for two or more Operating Contexts may be combined into a single logic configuration, potentially with parameterization, at the potential expense of performance or capacity reduction. Techniques for such hardware scheduling are already well-known from the synthesis literature.
As a result of linearizing equation systems around an Operating Context prior to code generation or synthesis, addressing of operands by processors or re-configurable logic is substantially simplified, as shown in FIG. 11 . For clusters of one or more memory arrays, a base address may be assigned ( 500 ) from which operands of interest may be referenced (such as Quantity 502 , Extended Literal 503 or Digital Signal Effective Value 504 ). A processor or logic may then reference the required object value by adding a known or computed offset to the base address ( 511 ), allowing a single instruction to generate an effective address needed to reference an operand ( 508 ). Reference patterns for declaratively nested subprograms and objects where the subtype constraints are dynamically elaborated are only slightly more complex. Techniques for handling these and related reference patterns are well known to those skilled in the art of compiler backends or behavioral synthesis.
FIG. 12 shows the preferred embodiment of an innovative apparatus used to compile and simulate digital, analog, mixed-signal and/or full-wave models of a design. This card fits into an apparatus previously disclosed in U.S. Pat. No. 5,999,734. Jacks marked 267 may be used to connect with other such cards using a switch, ring or other direct connection technology familiar to those skilled in the art of such designs. In a like fashion the Host Processor Bus ( 261 ), such as a PCI interconnect, may be used to access processors, accelerators, network and interconnect adapters, file systems and memory using device drivers or direct access via techniques common to those skill in implementing such interfaces. The following will then focus on explaining one such Accelerator Card ( 268 ) with the understanding that such discussion generalizes to apparatus where more than one such card is found on the same Host Processor Bus ( 261 ) or via interconnects in a cluster ( 267 ).
The switching controller ( 265 ) allows either other cards attached to the Host Processor Bus ( 261 ), one or more General Purpose Processors ( 267 ) present on the card or devices attached to the interconnect fabric ( 267 ) to access local Dynamic Memory ( 272 ), one or more Multiport Memory ( 262 ), other devices connected to the Host Processor Bus ( 261 ), other Accelerator Cards ( 268 ) attached via the Interconnect ( 267 ) or a Peripheral Bus ( 270 ). The Interconnect Controller ( 263 ) and Peripheral Control ( 271 ) respectively implement transmission and reception protocol for their respective Interconnects ( 267 and 270 ). Timers and I/O devices ( 266 ) support operating systems or real-time executives executing on one or more General Purpose Processors ( 264 ).
Each Multiport Memory ( 262 ) stores compiled logic configurations implementing executables for specific Models, Operating Configurations and partitions as well as object values and other temporary storage. Electronically Re-configurable Devices (FPGA) attached to the Multiport Memory support logic re-configuration for various models, partitions and Operating Contexts. Direct connections represent the change (delta) in quantity or signal values using encodings such as those shown in FIG. 16 . One or more Multiport Memory banks ( 262 ) with one or more associated FPGA devices may be located on each card. Furthermore the Multiport Memory ( 262 ) banks may be comprised of one or more device in order to achieve the desired width and depth. Direct connections representing the change in quantity or signal values may be made among FPGA devices connected to distinct Multiport Memory ( 262 ).
The Peripheral Interconnect, accessible via the Peripheral Controller ( 271 ), supports the attachment of component models with encapsulated simulation model(s) (for example, comparable to the Multiport Memory ( 262 ) contained directly on the Accelerator Card). For example, this interconnect and controller might follow the Universal Serial Bus or Firewire (IEEE 1394) protocols.
One such encapsulated simulation model for attachment via the Peripheral Interconnect ( 270 ) is shown in FIG. 13 . The Simulation Controller ( 600 ) provides some means of supplying simulation data and retrieving simulation data from the Multiport Memory ( 262 ). Operation of the Multiport Memory ( 262 ) and FPGA devices ( 260 ) closely follows such models running on the Accelerator Card. Since operations on the Peripheral Interconnect ( 270 ) do not allow retrieving a compiled model from the apparatus shown in FIG. 13 , the implementation of models contained within the Non-Volatile Configuration Memory ( 600 ) or burned onto FPGA devices is as secure as the device package. The package may be encapsulated so as to erase the model configuration data if the encapsulation is physical interrupted.
In order to avoid the need for incremental compilation, models contained within the encapsulated simulation peripheral shown in FIG. 13 must have suitable logic configurations compiled for any supported Operating Context and contained within either the Non-Volatile Configuration Memory ( 600 ) or retained in the FPGA ( 260 ). Comparable techniques pre-generating logic for all supported Operating Contexts may be used for FPGA devices on the accelerator card at the expense of substantial pre-simulation compilation time and usage of persistent storage capacity.
FIG. 14 illustrates the operating mode executing simulation of an analog partition using the apparatus shown on FIG. 12 . Execution starts with 612 , copying changes in the value of digital and analog objects which are altered outside of the partition and read by one or more equations mapped onto the current FPGA ( 260 ). Registers and/or memory arrays retain the current value of all objects (analog and digital) referenced or assigned by the current partition ( 610 ).
One or more means of evaluating expressions on either side of a characteristic equation must be provided on the FPGA device ( 602 ). Behavioral synthesis techniques for compiling expressions into such logic are well known to those skilled in the art of behavioral synthesis. In order to fit at least one characteristic equation from an equation system onto each FPGA, serial implementations of operators may be required. Such serial implementations for both floating point and integer representations are well-known to those skilled in the art of logic design. Furthermore, the same expression evaluation logic may be used for more than one characteristic equation evaluation using well-known hardware scheduling techniques.
When the left and right hand side of each characteristic equation has been evaluated, the value of the left and right hand side must be compared (such as by subtraction) and the magnitude of the result compared against the applicable tolerance (typically represented as a literal in storage or embedded in logic configurations). If the magnitude difference between left and right hand sides is less than the tolerance for all equations in the partition, the current object values result in analog solver convergence for the current cycle ( 604 ) and partition. Conversely, if the result is greater than the tolerance ( 605 ), the analog solver will continue iterating ( 623 ).
For each quantity, consider the set of all characteristic equation expressions referencing the quantity. For each such reference, some means of computing a delta change in the quantity value must be chosen to tend toward convergence with minimal overshooting. One such means is to combine the sign of the characteristic equation inequality, the magnitude of the left and right hand side difference, the slope (dependence) of the expression on the quantity (simplified by the implied linearization) and sensitivity of the expression to the quantity to arrive at a delta change in the quantity value implied by the expression. Other means with functionally comparable result will be evident to someone skilled in the art of numerical analysis.
Each quantity referenced on other FPGA devices must have a partial delta exported from each FPGA referencing the quantity to all other FPGA devices using the quantity resulting in a global delta ( 608 ) for each quantity on each cycle of the analog solver. If the quantity is used more than once on the same FPGA, the delta values may be combined with appropriately higher weighting when the delta is subsequently exported ( 609 ). Delta values are then imported ( 609 ) and combined to yield a composite delta value for each quantity on each cycle of the analog solver. This delta value is either separately combined on each FPGA using a quantity or exported and re-imported depending on the static availability of time-slots on FPGA pins to encode the delta. Delta values then generate a control signal for each means of up/down changes to the quantity values ( 601 ).
After quantities have been globally and consistently updated ( 601 ), the Analog Solver re-evaluates ( 611 ) the Operating Context associated with the quantity values resulting from Step 601 . This re-evaluation was previously described using FIG. 8 . Re-evaluation ( 611 ) comprises the constituent Steps 350 , 351 , 356 , 357 , 354 , 355 and 358 . Following re-evaluation the analog solver may continue with another iteration of the FPGA-based analog solver ( 629 ) or may complete the current analog solver using a software analog solver ( 629 ) via some means of initiating software intervention such as a trap. Trap to the software-based solver specifically results from the need to converge over a wider capture range than the hardware provides, resulting from a discontinuity in quantity values or a failure to converge after a specified number of cycles through path 629 . When the software-based analog solver completes it continues with execution of the Digital Simulation Cycle ( 609 ).
When the FPGA-based analog solver converges ( 604 ), any integral or differentials derived from quantity values must be updated ( 606 ). Concurrently any quantity or derived quantity values must be copied ( 607 ) from the FPGA ( 260 ) to Multiport Memory ( 262 ). As copying of the required quantity and derived quantity values completes, the interleaved digital simulation cycle may begin ( 628 ). As the new digital values result from the simulation cycle, the analog solver cycle may begin again ( 614 ) until reaching an implied or explicit breakpoint in time or other values.
Ideally all quantity values in the FPGA would be mapped directly to up/down counters. In order to simulate models for larger designs than could be directly implemented in counter logic, FIG. 15 shows how both explicit and implicit objects required for simulation of the partition may be partially or totally mapped into memory arrays ( 650 and 660 ) associated with the FPGA. The FPGA may contain the memory arrays internally or the memory arrays may be external. Objects contained in the arrays may include Read-only Literals such as tolerance values ( 651 ), Signal values ( 652 ), Shared Variables ( 653 ), Quantities ( 654 ), Terminals ( 655 ), Temporaries ( 656 ) and local or global Delta values ( 657 ). Even internal to an FPGA, multiple memory arrays are common and may be used for parallel evaluation of Equation System Expressions ( 602 ), expression comparisons ( 603 ), Delta values ( 601 and 608 ) and computing the Operating Context ( 611 ). Many variations on the register and arithmetic logic unit shown in FIG. 15 will be evident to those skilled in the art of processor design.
Pins used to interconnect logic internal to an FPGA ( 260 ) with logic external to the FPGA, such as another FPGA ( 260 ) or Multiport Memory ( 262 ) were previously used to represent signal values directly or using Time Division Multiplexing (TDM) to implement a digital simulation. Particularly in the context of analog simulation, mixed simulation or full-wave simulation (but also for digital simulation), representation of signals on pins (and associated interconnects) makes inefficient use of scarce pin and interconnect resources since some bits of the value (typically the more significant bits) change infrequently compared to the least significant bits.
FIG. 16 shows an improved, delta-based representation using pins and interconnects to represent the change in object value. A bit-wide interconnect may use both edges to represent transfer of a unit defined at compile time, such as a fixed number of charge or energy units ( 701 ). Such representation is exceptionally compact and makes efficient use of the power required during simulation to charge pins and interconnects. This representation is especially efficient for full-wave and high-frequency analog simulation. In general deltas consist of a sign (such as 703 ) and one or more bits of value (one bit shown at 704 , a range of bits shown as 704 to 705 ). Furthermore, the several delta representations may be time-multiplexed on the same pins and interconnect using either synchronous time division multiplexing (the same delta appears at regular intervals on the pins and interconnect) or may append an additional field to transmit a specific delta value on demand (where the field indicates which delta value is on the pins and wires on a given cycle).
Implementation of the full-wave solver in FIG. 17 closely tracks implementation of the analog and mixed-signal solver in FIG. 14 . Quantities implement elemental electrical and magnetic field intensity. Expressions reflecting finite element implementations of Maxwell's equations (and continuity) replace expressions implementing the left and right hand side of equation system inequalities. Continuity comparisons and delta computations closely track the analog and mixed-signal equivalent. Whereas there are many formulations of a full-wave field solver evident to those skilled in the art, the close correspondence with analog and mixed signal solvers both facilitates integration and facilitates integration of digital, analog, mixed-signal and full-wave simulation into an effective composite simulation. The closely related implementations also facilitate optimizations to solve common problems, such as concerns of numerical representation accuracy.
Analog, mixed-signal and full-wave simulation, like many iterative numerical problems, require representation of object values with substantial range and precision in order to maintain accuracy and minimize the impact of representation or arithmetic errors accumulating. Comparable challenges arise in control loops and signal processing applications.
FIG. 18 shows an arithmetic logic unit which accepts input ( 812 and 813 ) which may result in an output which is too large to represent, too small to represent or which approximates the least significant bits of the result. For example, if the arithmetic logic unit, associated data paths and registers is designed to represent a domain of integers from 0 to 7, adding the values 7 and 7 would result in a number too large to represent (overflow), subtracting 7 from 0 would result in a number too small to represent (underflow), dividing 4 by 3 would result in a number which cannot accurately be represent (loss of precision).
In order to reduce the probability and impact of overflow, underflow or loss of precision, iterative numerical applications commonly employ a floating point representation consisting of a mantissa, implied base and exponent. Arithmetic operations involving such floating point representations are more complex to implement, are more likely to contain an implementation error, require additional gate delays to implement. Designing using a numerical representation with a larger domain reduces the probability of underflow, over-flow or loss of precision at the expense of addition gate complexity, power and size (all usually undesirable properties of a design).
With a suitable initial choice of a numeric representation, the probability of overflow, underflow or loss of precision can be made arbitrarily low, however external factors such as the number of iterations actually taken by an algorithm often remain beyond the designer's control. Therefore most arithmetic implementations provide some means for executing trap or exception software to handle such cases with a more complex (but slower) implementation. In the prior art, once a value is outside of the range efficiently supported by hardware, the software implementation (trap handler) continues to take longer to implement arithmetic operations. In time-critical applications such as a control loop, such delays may then lead to consequential failures.
The present invention takes advantage of the flexibility provided by electronically re-configurable logic (FPGA) together with the tight proximity of an Incremental Compiler ( 5 ) so as to respond to hardware-detected underflow, overflow or loss of precision by a process consisting of reading the existing state related to the change, modification to the Elaborated Representation ( 4 ) so as to increase the domain range, shift the range or scale the range, Recompiling Related State and Logic ( 803 using 5 ), Incrementally Binding and Scheduling ( 451 ) the new functionality, Incrementally Re-synthesizing ( 460 ), Incrementally Scheduling ( 460 ), Incrementally Re-timing ( 460 ), Incrementally Placing and Routing ( 461 ), merging the previous state with the new logic configuration and incrementally re-loading the logic configuration and merged state. The computation then continues at full speed.
One may readily argue that the innovation is not useful since if resources were available initially on the FPGA to increase the domain, shift the range or scale the range it could be more efficiently and reliability be done during the initial design. This invention's utility lies in its ability to selectively expend FPGA resources based on actual usage rather arbitrarily resource usage, power and size based on the incomplete information available at design time (which may be years before the logic configuration is actually used).
As a further improvement of this invention, some functionality must be provided to effectively handle a Technology Binding and Schedule step ( 451 ) when no resources are efficiently available to implement a change in the Elaborated Representation ( 4 ). Periodic sampling of actual values, perhaps during the system's idle time, provides a general purpose processor with data on the most probable value ranges currently being encountered. Ranges and precision of logic may be immediately decreased in other areas to permit an incremental recompilation as long as the immediate values present at the time of recompilation can be fully and accurately represented. However if decreases in the range or precision of some logic immediately trigger a recompilation then the innovation may not be efficient. Therefore profile data on the range and precision of each value and arithmetic logic unit over time enables more efficient overall changes to the Elaborated Representation ( 4 ).
Particularly in the context of analog, mixed-signal and full-wave simulation using an FPGA, this innovation facilitates accurate and efficient use of an integer representation rather than requiring the size, latency and power requirements of a floating point representation within the FPGA. The resulting integer logic implementation can retain the same range as the floating point representation when required while achieving increased and uniform precision. Uniform precision across the entire domain of the representation increases numerical stability and accuracy of iterative numerical applications (such as simulation) since any precision errors introduced by eventual rounding are uniform across the domain. Fortunately with the present invention such rounding need not occur until FPGA resources are exhausted and then in a uniform and instantaneous fashion which further increases numerical accuracy.
At a broader level, the ability to create either more detailed (synthesized) or more abstract (higher performance) of an existing model or actual, realized device are important to the ability to accurately simulate a design using the invention disclosed here. The same capabilities are useful in the realization process when there is a need to synthesize a realizable analog or mixed signal model from a behavioral design. FIG. 19 illustrates a method for semi-automatically generating more detailed or more abstract models given an existing, black-box analog or mixed signal component simulation ( 853 ) or equivalently an actual device present in a test system allowing external presentation of simulus and response sampling ( 855 ).
Model generation begins with an incrementally formed Template Library ( 868 ), detailed in FIG. 20 . The template library iteratively translates a sequence of model specifications ( 870 ) either directly into a tem-plate match against an existing template in the library or indirectly via generation of a matching template via Template Generator ( 900 ). Each matching template consists of two views: one view as an equation system (perhaps with embedded conditionals and reference to digital interface objects) and the other view as a structural model in which the components are drawn from a small set of generally accepted terminal components. The preferred embodiment specifically uses the set of SPICE components augmented with BSIM models and RF/MW models such as transmission lines and specific antenna forms. The initial Template Library ( 868 ) must begin with a library of existing templates. In the preferred embodiment this library is read in from files and a directory hierarchy using FTL Systems' AIRE/CE File Intermediate Representation (FIR) however those skilled in the art will recognize that other intermediate representations may readily be adapted to the method.
The means of Template Selection ( 850 ) iterates between a refined specification of the required template ( 870 ) and iterative probing of the simulated ( 853 ) or actual ( 855 ) reference via the means of Test Model Generation and Analysis ( 851 ). Template selection evolves through three selection phases: a means of matching the template and reference based on the number and type of ports, establishing the VHDL-AMS entity to be generated ( 904 ), template matching based on switch-level topology ( 905 ) and matching based on equivalent canonical equation formulation ( 906 ). The preferred embodiment uses Verilog's predefined switch level models for convenience, however those skilled in the art will recognize that other switch level and equivalent representations may be adapted. Matching based on equivalent canonical form will be discussed below.
Following tentative selection of a template, equation specifics are fit to the model in the equation fitting step ( 852 ). Various techniques for experimentally fitting equations to data are well known, such as the excellent summary applied to non-linear and microwave devices by Turlington. Other comparable techniques are well known to those skilled in the art of numerical analysis. Finally the model formation concludes with parameter fitting, again using well-known techniques for fitting experimental data to a system of equations. Each refinement in the equation view drives an equivalent, incremental change to the structural view.
In FIGS. 19 and 20 , Steps 850 , 852 and 854 rely on a common module which provides a means of converting ambiguities in a system of equations into a self-contained test case (consisting of a test bench and stimuli), a means of submitting the test case to a simulated or actual device and a means of responding to 850 , 852 and 854 . For convenience interfaces 863 and 864 generate a well-known SPICE deck format and accept a table consisting of a value for each probed quantity at each time step. Other, equivalent formats are well known to those familiar with SPICE simulation. The test set interface ( 865 and 866 ) uses the same protocol as 863 and 864 . An interactive test set (written in Perl with network extensions) converts the SPICE inter-face to a set of equivalent General Purpose Interface Bus (GPIB) commands. Other, equivalent interfaces are well known to those skilled in the art of test equipment instrumentation.
Test Model Generation and Analysis ( 851 ) uses a parameterized, in-memory representation for the preferred embodiment, such as FTL Systems' AIRE/CE Internal Intermediate Representation (IIR). Other, comparable representations are known to those skilled in the art of intermediate format design and implementation.
Finally, IIR may be converted into a textual format ( 867 ) using an IIR to source code printer. Such a module is included with FTL Systems' Tauri source code analyzer, however other and comparable mechanisms for printing an intermediate format as text are commonly included in hardware description language compilers.
Both to implement Template Selection ( 850 ), Equation Fitting ( 852 ) and Parameter Fitting ( 854 ) as well as for purposes of manual design and optimization, it is useful to be able to compare two analog or mixed signal models without the need for simulation, as shown in FIG. 22 . When incorporated in model generation, the reference and comparison models may immediately be supplied as step 902 / 903 . When the models are first made available as source code, the source code must be analyzed ( 900 / 901 ) using 1, elaborated ( 902 / 903 ) using (3) and then converted into a canonical intermediate format, such as C. J. Shi's Determinant Decision Diagrams (DDD). Other canonical forms for equation systems are evident to those skilled in numerical array and graph algorithms.
Existing graph matching algorithms first match nodes and branches in the canonical representations ( 906 ), then compare attributes or values assigned to corresponding nodes or branches ( 908 ). If either graph matching fails to find a correspondence between the nodes and branches of the reference and comparison canonical forms, the match fails.
If the attribute values of reference and comparison models are “close”, it is useful for the designer to visually compare the two models, using the graphical user interfaces shown in FIG. 21 . In this interface partitions ( 950 ) and objects ( 951 ) have been brought into a one to one correspondence, then represented with an icon. Each icon is divided into segments with a distinct color assigned to each segment ( 952 ). The color represents the comparative aggregate value (average over space and time) of each attribute. When the two halves are of the same color, there is no aggregate difference ( 953 ). Conversely a wide disparity in color visually calls attention to the difference ( 954 ). A color bar associated with the user interface allows the designer to manually force the attribute value ( 955 ). The designer may then initiate re-computation of the comparison in order to manually perform a sensitivity analysis.
Those skilled in the art will further appreciate that the present invention may be embodied in other specific forms without departing from the spirit or central attributes thereof. In that the foregoing description of the present invention discloses only exemplary embodiments thereof, it is to be understood that other variations are contemplated as being within the scope of the present invention. Accordingly, the present invention is not limited in the particular embodiments which have been described in detail therein. Rather, reference should be made to the appended claims as indicative of the scope and content of the present invention. | An innovative method is taught for accelerating the simulation rate of differential equation systems having behavior piece-wise continuous in both value and time. Specifically, a system of differential equations representing the behavior of a physical system comprised of electronic, optical, or mechanical components may be simulated more rapidly using this method. The method utilizes incremental and iterative reconfiguration of digital logic wherein each configuration of the logic operates to yield a unique future value or range of values for each time-varying state variable within a system of equations representing a linear approximation of the original differential equation system for state variable values defined initially or at the onset of an iteration. Various configurations of the digital logic may be pre-computed or computed on demand, optionally caching such configurations for subsequent reuse. | 6 |
BACKGROUND OF THE INVENTION
The present invention relates to an arc welder and more particularly, the present invention firstly relates to a rectifier phase control type arc welder and more specifically to an arc welder which can fully contribute to the reduction of the number of components of a welder control circuit and a manufacturing cost thereof, the enhancement of performance of the welder, operability on a part of users and the feasibility of change of functions.
Secondly, the present invention relates to an arc welder in which welding condition setting signals determined in a welding process are stored and they are subsequently read out selectively to carry out the welding process.
Thirdly, the present invention relates to an arc welder in which an output voltage or an arc voltage and a welding current are controlled in unison or individually, and in the in-unison control mode an optimum output voltage or arc voltage and welding current relationship is continuously maintained to attain stable welding.
Regarding the first point, a prior art D.C. arc welder of the SCR firing phase control type has a disadvantage that the number of components of the control circuit is large. For example, the firing phase control circuits are provided one for each of the SCR's. Accordingly, it is troublesome to determine whether desired conditions are met. In addition, since it is based on analog control, automation of production of the circuits such as by IC circuits or LSI circuits is hard to attain and a manufacturing cost is high. From the view points of change of functions of the welding sequence and the enhancement of performance, the prior art system which is based on the analog control is not easy to change design or, if not impossible, a problem of price is encountered. Moreover, the circuits are utilized in the welding environment and are, therefore, subject to damage from, for example, heat generated during welding. The prior art system also did not provide sufficient protection with respect to the damage of the control circuit due to malfunctions of the control components.
Regarding the second point, it has been difficult in the past to determine the welding conditions suited for a particular article to be welded in known welding methods such as arc welding or resistor welding, and a considerable level of knowledge and experience were needed. For example, in a semi-automatic gas shield arc welding in which a consumable electrode is continuously fed to attain high efficiency welding, a welding current and a welding voltage are specifically determined by the experience and knowledge of a welding operator although general conditions of process are known for particular objects to be welded. Accordingly, it is difficult for an unexperienced operator to carry out the welding process. Furthermore, where the process is carried out under at least two process conditions, control elements for one process condition, which has once been met properly, has to be changed in order to meet the other process condition, and the conditions must be checked for their properness by a test arc whenever the conditions are changed. Even where a single process condition is used, if a control element such as a potentiometer is moved inadvertently, the original proper condition is lost.
In addition, the control element is preset to a position which is expected to meet the desired process condition, but whether it is a proper position or not is determined only after a welding power has been actually fed. In other words, whether the presetting is proper or not cannot be determined until welding occurs. Furthermore, since the adjustment is carried out using marking such as a scale or digits on a control panel of the control element, precision of setting is poor and the adjustment is difficult to attain. In the apparatus such as the semi-automatic gas shield arc welder described above in which the welding process conditions are determined by setting the welding voltage and the feed rate of the consumable electrode, if the process is started without having exactly set the control elements, a hole is formed in the article to be welded, defect beads are formed, or the welder is damaged or the lifetime thereof is shortened.
To resolve the above problems, it has been proposed to automate the setting of the welding conditions which were set in the past by the operator for each of the welding processes. In one proposed method, initial condition setting signals for welding and event signals (such as actual welding voltage and welding current) desired from the welding process carried out in accordance with the initial conditions are stored in storage means, and when the next welding process is to be initiated the initial condition setting signals are read from the storage means to start the welding process based on those signals, and after a predetermined time period has elapsed, the event signals are read from the storage means which are then used as the welding condition signals and the process are controlled to meet those conditions. (See Japanese Patent Publication No. 40182/73). However, in many cases, whether the settings are proper or not cannot be determined until after the welding process has actually been carried out, and the preset conditions are usually modified during the welding process. Accordingly, where the initial condition setting signals and the event signals stored are subsequently used on the assumption that they are correct, proper welding may not be attained. In addition, since the event signals in the welding period are all to be stored, a large capacity of storage means is required, and read and write operations to the storage means have to take place almost continuously.
Finally, regarding the third point discussed above, the prior art union/individual control circuit comprises a group of resistors. In order to generate an exact SCR firing reference voltage V BV for an arc voltage for a particular wire diameter based on an SCR firing reference voltage V BM of a wire feeding motor in the union control mode, high precision resistors are needed. However, the characteristics of the resistors change by temperature change which temperature changs are prevalant in a welding environment. Therefore, high precision is not attained in the union control mode. In addition, a compensation circuit for voltage fluctuation is not satisfactory although it is provided. A relation between the welding current and the welding voltage is non-linear and it is difficult to develop a proper relation by resistors. Furthermore, since the resistors are needed one for each of the wires of different diameters, the number of components is large, and the adjustment and the test for the potentiometers when the welder is shipped are troublesome. The operability is also poor.
SUMMARY OF THE INVENTION
It is an object of the present invention to provide an arc welder having a control circuit which has a reduced number of components, is simple in construction and is highly reliable.
It is another object of the present invention to provide an arc welder which can repetitively carry out the same desired process conditions, can carry out the welding process with proper process conditions and has a condition storage circuit which does not need a large capacity of storage means.
It is still another object of the present invention to provide an arc welder having a high precision and highly stable union/individual control circuit which does not need the adjustment and the testng of resistors.
The arc welder in accordance with the first mentioned object of the present invention is characterized by an SCR circuit responsive to an A.C. voltage input to regulate an arc welder power supply, a first detection circuit for detecting an output level of the arc welder power supply, a second detection circuit for detecting a predetermined point on a waveform of the A.C. voltage, a setting circuit for presetting the output level of the arc welder power supply, and a control circuit for receiving the outputs of the first detection circuit and the setting circuit each time when the second detection circuit detects the predetermined point on the A.C. voltage waveform to calculate firing timing of an SCR and count timing pulses to produce an SCR control signal when the count reaches the firing timing.
The arc welder in accordance with the mentioned object of the present invention is characterized by welding condition setting means, control circuit means for detecting and feeding back a welding output to control the welding output with a target value determined by condition setting signals derived from the welding condition setting means, storage means for storing one or more proper condition setting signals determined by the welding condition setting means, and storage signal readout circuit means for reading out the storage signals in the storage means to establish those signals as the target value in place of the condition setting signal determined by the welding condition setting means.
The arc welder in accordance with the third mentioned object of the present invention is characterized by storage means for previously storing one or more optimum relations between an arc voltage or an SCR output voltage (hereinafter represented by arc voltage) and a welding current or a rotation speed of a wire feeding motor (hereinafter represented by welding current), and control means for reading from the storage means an optimum value of one of the arc voltage and the welding current based on the other to control the welding current and the arc voltage.
BRIEF DESCRIPTION OF THE DRAWINGS
FIG. 1 shows an overall view of an embodiment of the present invention.
FIG. 2 illustrates a principle of control in the present invention.
FIG. 3 shows voltage waveforms in accordance with the principle of control of the present invention.
FIG. 4 shows detail of one embodiment of the present invention.
FIGS. 5 and 6 show flow charts of a control program.
FIG. 7 illustrates a table used in the program.
FIG. 8 illustrates an example of a welding sequence.
FIG. 9 shows an overall configuration of an embodiment of a condition storage circuit in accordance with the present invention.
FIG. 10 illustrates a flow of position data formation of a setting element.
FIG. 11 illustrates a flow of determination of a proper setting signal.
FIG. 12 shows an embodiment which enables fine adjustment.
FIG. 13 illustrates an example of monitoring of stored data by a meter.
FIG. 14 shows an example of an adder circuit used in a D-A converter.
FIG. 15 a relation between an adjusted position of a setting element and an output level.
FIG. 16 shows a block diagram of one embodiment of a union/individual control circuit of the present invention.
FIG. 17 shows detail of a union/individual selection circuit in FIG. 16.
FIG. 18 illustrates a flow of union/individual control operation in FIG. 17.
FIG. 19 shows an overall configuration of one embodiment of an arc welder having the union/individual control circuit.
DESCRIPTION OF THE PREFERRED EMBODIMENTS
FIG. 1 shows, in a block diagram form, an overall configuration of one embodiment of the present invention which uses a microcomputer.
In FIG. 1, voltages from a three-phase A.C. power supply 1 are stepped down by a welder transformer 2 to voltages suitable for welding and also converted to six-phase A.C. voltages each having a phase difference of 60 degrees. They are applied to anodes of SCR's 3. Numeral 4 denotes a feeding wire type torch electrode to which a D.C. voltage is supplied from the SCR's 3.
On the other hand, the A.C. voltages from the three-phase A.C. power supply 1 are also applied to motor SCR's 6 through a transformer 5. A motor M functions to feed a wire to the welder torch electrode 4 and it is driven by a D.C. voltage from the SCR's 6. A welding current of the welding torch is proportional to the feeding speed of the wire or the rotation speed of the motor M. Numeral 7 denotes a main control circuit for effecting SCR firing phase control, wire feed control for the motor, and gas shield control for arc, and it comprises a central processing unit CPU, a memory ROM for storing a control program, a memory RAM for temporarily storing data during processing, an input interface II, an output interface IO and an SCR firing timing circuit (T) 8. Input signals to the main control circuit 7 include signals supplied from an A.C. voltage zero-crossing point detection circuit 9, an arc voltage feedback circuit 10, a motor speed feedback circuit 11 and various input setting switches 12, and output signals include those signals which are supplied to the arc voltage regulating SCR's 3, the motor speed controlling SCR's 6 and a gas solenoid value MV. The timer circuit 8 is connected to the input and output interfaces II and IO in the main control circuit 7 so that on and off conditions thereof are program controlled.
The operation of the circuit of FIG. 1 is now explained. Each time a zero crossing point of the A.C. voltage from the A.C. power supply 1 is detected by the zero-crossing point detection circuit 9, an interruption signal is supplied to the CPU through the input interface II. When the CPU receives the interruption signal, it fetches the signals from the arc voltage feedback circuit 10 and the motor speed feedback circuit 11 in accordance with a predetermined program stored in the ROM to calculate firing timings for the SCR's 3 and the SCR's 6 for controlling the voltage and the current of the welding torch electrode 4. The calculation results are temporarily stored in the RAM. Then, the timer circuit 8 is turned on to count the elapsed time from the zero-crossing point. They are compared with the calculation results, and when a predetermined firing time is reached the signals are sequentially produced to fire the respective SCR's 3 and 6. Then, the timer circuit 8 is turned off. The CPU repeats the above process each time the interruption signal is received in response to the A.C. voltage zero-crossing detection. The CPU also reads in the signals from the input setting switches 12 upon power-on or upon demand to calculate the welding voltage and the welding current in accordance with the welding conditions.
Referring to FIG. 2, a principle of SCR firing phase control in the present invention is explained in detail. In FIG. 2, Ed represents a full-wave rectified voltage of one phase of the A.C. voltage, and ZPS represents a pulse signal which is applied to the CPU as the interruption signal through the input interface II in response to the zero-crossing detection by the zero-crossing detection circuit 9 shown in FIG. 1. When the pulse signal ZPS is applied, the CPU reads in the signals of the arc voltage feedback circuit 10 and the motor speed feedback circuit 11 in accordance with the procedures of an interruption analysis program P1 stored in the ROM and calculates firing timing t 1 for the welding voltage controlling SCR's and firing timing t 2 for the welding current controlling SCR's (i.e. motor speed controlling SCR's) to attain the desired welding voltage and welding current, and temporarily stores the calculation results in the RAM. After the completion of the above process, the timer circuit 8 shown in FIG. 1 is started to produce the timer pulse signals TPS of a predetermined frequency. When the timer pulse signals TPS are applied, as the interruption signal, to the CPU through the input interface II, the CPU follows another interruption analysis program P 2 to count the number of times of the interruption by the tLmer pulses TPS, compares the count with the numbers of pulses corresponding to the firing times t 1 and t 2 calculated in accordance with the program P 1 , and when they are equal, the CPU provides gate signals GPS 1 and GPS 2 to the corresponding SCR's through the output interface IO. The gate signals may be either pulses or square waves. When the count of the timer pulses TPS has not reached the preset count, the CPU, after having counted the TPS, moves to the execution of a main program PM to carry out another job until next timer pulse interruption signal is received.
FIG. 3 shows voltage waveforms for a pair of SCR's in accordance with the above principle. In FIG. 3, Ed represents the full-wave rectified voltage, ZPS represents the zero-crossing pulse signal, GPS represents a gate signal to the SCR's, V s represents an anode-cathode voltage of the SCR's, V q represents a load voltage when the SCR's are loaded, and V r represents a motor voltage when a motor is connected to the SCR's.
FIG. 4 shows embodiments of the arc voltage feedback circuit 10 and the motor speed feedback circuit 11 shown in FIG. 1 as well as signal lines between those circuits and an I/0 interface IIO (corresponding to the input interface II and the output interface IO shown in FIG. 1). In FIG. 4, the motor speed feedback circuit 11 comprises a comparator CMP 1 , an D/A converter D/A-1 for producing a reference motor speed analog data, and a comparator CMP 2 which receives a motor counter-e.m.f. The reference motor speed data is produced by a sequential comparison method in the following manner. The CPU first sends out a minimum or maximum scale reference motor speed digital data DAS through the interface IIO. The digital data is converted to an analog data by D/A-1, which is then compared with a voltage across a current regulating potentiometer VR 1 by the CMP 1 . A signal ADS representing the compared result is supplied to the CPU through the interface IIO. Depending on the compared result, the CPU increments or decrements the reference motor speed data DAS by one and presents the modified data to the D/A-1. The above process is repeated until the signal ADS reaches zero to finally produce the reference motor speed data DAS which corresponds to the voltage of VR 1 . The voltage of VR 1 , once it has been set, is usually not changed during the operation, and in a steady state operation the above comparison process is carried out once or twice. Each time the zero-crossing signal ZPS is supplied from the zero-crossing detection circuit 9, the analog signal corresponding to the reference motor speed data DAS is compared with the counter-e.m.f. which represents the actual speed of the motor M by CMP2 and the compared result is supplied to the CPU as a signal CMS through the interface IIO. Depending on the compared result, the CPU increments or decrements the previous motor SCR firing phase angle data by one and stores the modified data in the RAM. At the same time, the timer circuit 8 is started and when the count of the timer pulse signals TPS becomes equal to the data stored in the RAM, the gate signal GPS 1 is applied to the SCR's 6. The above process is repeated for each zero-crossing detection so that the motor speed M corresponding to the voltage of VR 1 is finally attained.
On the other hand, the arc voltage feedback circuit 10 comprises an arc voltage detector VD, a comparator CMP 3 and a D-A converter D/A-2. A selection switch SW 1 selects an individual control mode and a union control mode (controlled by VR 1 ) for the arc current and the arc voltage. A contact q is for the individual mode while a contact r is for the union mode. The operation of the arc voltage feedback circuit 10 is basically identical to that of the motor speed feedback circuit 11. In the individual control mode, CMP 3 compares a voltage across a voltage regulating potentiometer VR 2 with an output of the arc voltage detector VD and supplies a compared result signal CES to the interface IIO. Depending on the signal CES, the CPU increments or decrements the previous arc voltage SCR firing phase data by one each time the zero-crossing is detected, and stores the modified data in the RAM. When the count of the timer pulse signals TPS reaches the data stored in the RAM, the gate signal GPS 2 is supplied to the voltage SCR's. In the union control mode, a reference voltage data DES is calculated based on the reference motor speed data DAS instead of the voltage across VR2 and it is converted to an analog signal by D/A-2, the output of which is applied to one of the comparison input terminal of CMP 3. When the arc switch SW 2 is turned on upon ACS=0, the gas solenoid value signal MVS shown in FIG. 4 is turned on at a step 3 and the process waits for the zero-crossing interruption signal ZPS. When the zero-crossing interruption signal ZPS is read, the process branches to an interruption analysis program of FIG. 6 to be described later, and upon completion of the program the process goes back to the program of FIG. 5 and turns on the timer start signal ONS shown in FIG. 4 and waits for the interruption by the timer pulse TPS. When the timer pulse TPS is read, the process again branches to the interruption analysis program of FIG. 6, and upon completion of the interruption process, the process moves to a step 4. In the step 4, failure of arc in the welding process or other faults are detected and countermeasures therefor are executed. In case of failure of arc, for example, a high non-load voltage is applied to the comparator CMP 3. In order to prevent a malfunction caused thereby, a firing data calculated immediately before the failure of arc is produced so that normal control is restored when the arcing is started again. In the next step 5, a decision for ACS=ON is made again and if it is ON the process goes back to the step 4, and if it is OFF the process moves to a step 6. In the step 6, the interruption to the CPU is masked and all the SCR's are turned off. Then the process goes back to the step 1 to make decision for ACS=ON.
A flow shown in FIG. 6 is now explained. At a check point 1, the interruption is analyzed. If it is the interruption by the zero-crossing pulse ZPS, the process moves to IRQP, and if it is the interruption by the timer pulse TPS, the process moves to IRQT. In the IRQP, the ADS is first read and depending on the content thereof the DAS data calculated at the previous zero-crossing point is incremented or decremented and the modified DAS data is produced. This process is repeated until ADS reaches zero. Similarly, the firing angle calculated at the previous zero-crossing point, e.g. the data corresponding to t 1 in FIG. 2 is incremented or decremented and the modified data is stored in the RAM. Then, the status of the SW 1 is determined by CHS and if it is the individual control mode the process branches to a check point 3 where a similar process to that described above is executed. If it is the union control mode, the process moves to a check point 2 in which a reference voltage data is calculated based on the DAS data previously stored in the RAM and a table of relation between the DAS data and the DES data stored in the ROM, provides the calculated data to the DES and moves to the check point 3. Upon the completion of a series of IRQP program steps, the process goes back to the step of FIG. 5. The SCR firing angle calculation program includes a step to prevent overrun of the CPU to attain stable firing by providing limits (maximum and minimum) of the firing data to define a proper range for the firing angle. In the IRQT program, the number of the timer instruction pulses is counted and when the count reaches the firing time calculated in the IRQP program the arc voltage SCR's and the motor SCR's are fired. When the firing is completed or when the count has not reached the preset count, the process goes back to the main program or the step being executed at the time immediately after the timer interruption in FIG. 5.
FIG. 7 shows a relation between the reference motor data signal DAS and the reference voltage data signal DES when the arc current and the arc voltage are individually controlled. This relation is stored in the table in the ROM. FIG. 8 shows an example of a welding sequence. Various welding sequences can be carried out by altering the program stored in the ROM.
Referring now to FIG. 9, the condition storage circuit of the present invention is explained. FIG. 9 shows a block diagram of one embodiment in which an output voltage and a feed rate of a consumable electrode in a semi-automatic gas shield arc welder are simultaneously controlled. In FIG. 9, numeral 13 denotes a setting element for the welding current, and numeral 14 denotes a setting element for the welding voltage, both comprising potentiometers. When a target welding current is set by the setting element 13, a corresponding digital setting is produced by a closed circuit comprising a comparator 15 2 , a current setting signal processing circuit 16 and a D-A converter 17. When a target welding voltage is set by the setting element 14, a corresponding digital setting is produced by a closed circuit comprising a comparator 15 3 , a voltage setting signal processing circuit 18 and a D-A converter 19. For the target welding current setting provided by the setting element 13, the current setting signal processing circuit 16 first produces, in a digital form, an initial value of a comparison signal to be compared with the welding current setting. The digital value is then converted to an analog voltage by the D-A converter 17, which voltage is then compared with a voltage representing the welding current setting provided by the setting element 13, by the comparator 15 2 . Depending on the compared result, the current setting signal processing circuit 16 increments or decrements the previous initial value and retries the comparison. The above process is repeated until the outputs of the D-A converter 17 and the setting element 13 become equal to each other, when the current setting signal processing circuit 16 finally produces the digital value which corresponds to the welding current setting of the setting element 13. Similarly, the outputs of the setting element 14 and the D-A converter 19 are applied to the comparison circuit 15 3 where the comparison is repeated until both outputs become equal, when the voltage setting signal processing circuit 18 finally produces a digital value which corresponds to the welding voltage setting of the setting element 14. FIG. 10 shows a flow of operation of those closed circuits. The amount of increment or decrement for the comparison signal and the numbers of bit positions of the D-A converters 17 and 19 are determined in accordance with a required accuracy for the setting signals.
When the digital setting signals corresponding to the setting elements 13 and 14 have been determined, the welding process is carried out by a feedback control described below. In FIG. 9, numeral 3 denotes the welding voltage SCR's which receive a power from the A.C. power supply 1 through the welding transformer 2 and control the welding voltage applied to the torch electrode 4 arranged to oppose to the article to be welded, and numeral 6 denotes the motor SCR's which receives the power from the A.C. power supply 1 through the transformer 2 and control the speed of the feed motor M for the torch electrode 4. The welding current of the electrode 4 is proportional to the feed rate of the torch electrode 4 or the rotation speed of the motor M.
In the welding process, the digital welding current setting produced by the current setting signal processing circuit 16 is converted to an analog welding current setting by the D-A converter 17 and the analog setting is applied to one input terminal of a comparator 15 1 . Applied to the other input terminal of the comparator 15 1 is the output voltage of the motor speed feedback circuit 11 for detecting the speed of the electrode feed motor M. The analog welding current setting signal and the motor speed voltage are compared in the comparator 15 1 , and depending on the compared result a motor speed processing circuit 20 causes a motor speed control signal generating circuit 21 to generate a control signal to advance or retard the firing phase of the motor SCR's 6 by one step. As a result, the rotation speed of the motor M is controlled to follow the output of the D-A converter 17, that is, the welding current setting of the setting element 13. On the other hand, the digital welding voltage setting produced by the voltage setting signal processing circuit 18 is converted to an analog welding voltage setting signal by the D-A converter 19 and the analog signal is applied to a comparator 15 4 . Applied to the other input terminal of the comparator 15 4 is the output voltage of the arc voltage feedback circuit 10. The welding voltage setting signal and the detected welding voltage are compared in the comparator 15 4 , and depending on the comparison result an output voltage processing circuit 22 causes an output voltage control signal generating circuit 23 to generate a control signal to advance or retard the firing phase of the welding voltage SCR's 3 by one step so that the welding voltage of the torch electrode 4 is controlled to follow the welding voltage setting of the setting element 14. If proper welding is not attained by the above welding process, the setting elements 13 and 14 are adjusted to modify the setting conditions of the welding current and the welding voltage. As a result, the digital welding current setting and the digital welding voltage setting are modified by the closed circuit comprising the comparator 15 2 , the current setting signal processing circuit 16 and the D-A converter 17, and the closed circuit comprising the comparator 15 3 , the voltage setting signal processing circuit 18 and the D-A converter 18, respectively, and the motor speed and the welding voltage follow those settings.
Numeral 24 denotes a store instruction circuit which, when proper welding is attained in the welding process, issues a write instruction signal so that the digital welding current setting and the digital welding voltage setting determined by the processing circuits 16 and 18, respectively, are stored in a storage circuit 25. When the welding process is subsequently carried out based on the stored data, a stored data readout instruction circuit 26 issues a readout instruction signal. As a result, specified data stored in the storage circuit 25 is read out to the current setting signal processing circuit 16 and the voltage setting signal processing signal 18 so that optimum welding current setting and welding voltage setting are determined. When the data stored in the storage circuit 25 is read, the processing circuits 16 and 18 do not read in the outputs of the comparison circuits 15 2 and 15 3 .
A setting signal comparator 27 compare the digital data corresponding to the settings of the setting elements 13 and 14 determined by the processing circuits 16 and 18 with a data table of properly set data previously stored in the storage circuit 25. If both are equal in the comparison or not equal, signals are provided to a display 28 for identification. For example, when the welding current is set by the current setting element 13 and a proper welding voltage is to be determined by adjusting the voltage setting element 14, one may adjust the voltage setting element 14 while watching the display 28. In this manner, a proper setting position can be easily determined. FIG. 11 shows a flow of the operation of the display control. Alternatively, the output of the comparator 27 may be used to interlock the process so that the welding process is started only when the data corresponding to the settings of the setting elements 13 and 14 are equal to the proper data previously stored in the storage circuit 25. This reduces faults in the welding process such as failure of the arc.
In FIG. 9, when the data stored in the storage circuit 25 is read to use as the welding current and voltage settings, the welding conditions are fixed. Accordingly, it is inconvenient when the proper conditions shift by the variation of the size of article to be welded, change of environment and variation in individual operators. As a countermeasure therefor, an embodiment shown in FIG. 12 enables the fine adjustment in the reproduction operation. The embodiment of FIG. 12 shows an improvement in which the voltage comparator perform a dual function through switching of the circuit. When a switch 30 is thrown to a contact C, a comparator 37 corresponds to the comparator 15 4 shown in FIG. 9, and when the switch 30 is thrown to a contact D, the comparator 37 corresponds to the comparator 15 3 shown in FIG. 9. An adder 31, a linear amplifier 32 and resistors 33 and 34 correspond to the D-A converter 19 in FIG. 9. While only the portion pertinent to the welding voltage control is shown in FIG. 12, the portion pertinent to the welding current control may be similarly constructed.
In a standard welding process for checking the proper conditions, a switch 35 is thrown to a contact A to apply a power supply voltage +E to a potentiometer of the welding voltage setting element 14. The switch 30 is thrown to the contact C and a switch 36 is thrown to a contact E to establish an output feedback loop. Under this condition, the comparator 37 compares the feedback welding voltage with the reference welding voltage setting provided by the welding voltage setting element 14 to produce "1" or "0" output signal, in response to which the output voltage processing circuit 22 instructs the output voltage control signal generating circuit 23 to generate a control signal to increase or decrease the welding voltage to effect stabilization control of the welding voltage. When the setting position of the voltage setting element 14 is to be stored after the welding process, the switch 35 is kept at the contact A and the switch 30 is thrown to the contact D and the switch 36 is thrown to the contact F. As a result, a closed circuit is formed, which comprises the D-A converter including the adder 31 which receives the digital signal from the voltag setting signal processing circuit 18 and the linear amplifier for producing an analog-converted output, an auxiliary potentiometer 38, the comparator 37 and the voltage setting signal processing circuit 18, and the digital value corresponding to the potential of the welding voltage setting element 14 is established in the voltage setting signal processing circuit 18 by a similar operation to that of FIG. 9. The auxiliary potentiometer 38 is preadjusted to appropriately divide the output of the linear amplifier 32 with the divided output being supplied to the comparator 37. The digital value established in the voltage setting signal processing circuit 18 is stored in the storage circuit 25.
When the welding process is to be carried out based on the digital data read from the storage circuit 25, the switch 35 is thrown to the contact B, the switch 30 to the contact C and the switch 36 to the contact E. The welding voltage setting element 14 is set to a dividing point which corresponds to the dividing ratio of the auxiliary potentiometer 38. The dividing position can be readily set by displaying it on a control panel as the standard setting position in the stored data readout mode. By producing the stored data from the voltage setting signal processing circuit 18, the welding voltage setting corresponding to the stored data is applied to the comparator 37 through the adder 31, the linear amplifier 32 and the voltage setting element 14, and the stored data is compared with the feedback voltage so that stabilized feedback control of the welding voltage is attained. By appropriately adjusting the setting element 14, the voltage setting corresponding to the stored data applied to the comparator 37 changes so that the fine adjustment is attained.
FIG. 13 shows a circuit for monitoring the stored data in an inexpensive and simple way by an ammeter or voltmeter for indicating the welding phenomena such as welding voltage. The illustrated embodiment monitors the stored data of the welding voltage setting by a voltmeter 39 for indicating the welding voltage. Normally, a switch 40 is thrown to a contact G. Under this condition, the voltmeter 39 indicates the welding voltage across an output terminal 42 through a current limiting resistor 41. When the stored data is to be monitored, the switch 40 is thrown to a contact H to connect the output of the D-A converter comprising an adder 43 and a linear amplifier 44 to the voltmeter 39 through a potentiometer 45. As a result, the stored data corresponding to the welding voltage setting, applied to the voltage setting signal processing circuit 18 is converted to an analog voltage by the adder 43 and the linear amplifier 44 and the analog voltage is indicated by the voltmeter 39. By adjusting the potentiometer 42 or converting the stored data to give the same indication as that given by the actual welding voltage corresponding to the stored data, the check operation is further facilitated. Numerals 46, 47 and 48 denote resistors.
The D-A converter comprising the adder 43 and the linear amplifier 44 may be an exclusive circuit or it may be the circuit shown in FIG. 12. While FIG. 13 shows the circuit for indicating the analog signal converted from the stored data, the digital value provided by the voltage setting signal processing circuit 18 may be directly indicated by providing a digital display circuit.
An example of the adder circuit 31 shown in FIG. 12 is shown in FIG. 14. The adder circuit 43 shown in FIG. 13 is also basically similar. In the illustrated embodiment, a six-bit digital output is produced and the processing circuit 18 produces a binary coded digital output with bits P 0 -P 5 being either high level (+E) or low level (GND). Numerals 301-306 denote function resistors with a resistance ratio of adjacent two resistors being 2 with higher bit resistors being smaller. Accordingly, depending on the digital output P 0 -P 5 , the linear amplifier 32 produces an analog signal which changes stepwise. Because of six-bit configuration in FIG. 14, the analog signal is equidivided into 64 (=2 6 ) segments. In the welder, it is usually required to produce a certain level of output even at the lowest position of the function resistors of the setting element as shown in FIG. 15. Accordingly, a resistor 310 is connected to the power supply (+E) so that all of the bits of the digital output can be effectively used.
While the preferred embodiments of the present invention has been explained, the configuration of FIG. 9 as well as FIG. 12 may be constructed by a microcomputer. In such a case, the functions of the motor speed processing circuit 20, the current setting signal processing circuit 16, the voltage setting signal processing circuit 18 and the output voltage processing circuit 22 are consolidated by a central processor so that a desired process is carried out under a programmed control. The storage circuit 25 may be taken place by a RAM.
In FIG. 9, the closed circuit of 16, 17 and 15 2 or the closed circuit of 18, 15 3 and 19 is used to produce the digital signal corresponding to the setting signal of the setting elements 13 and 14, by sequential comparison. By inserting A-D converters between the setting elements 13 and 14, and the processing circuits 16 and 18, the digital signals corresponding to the setting signals can be directly produced.
Referring to FIG. 16, a union/individual control circuit of the present invention is explained. FIG. 16 shows a block diagram of one embodiment in which numeral 49 denotes the union/individual control circuit and a block 50 is a main control unit thereof. The control unit 50 comprises a storage circuit 51 which stores one or more optimum relations of the arc voltage and the welding current and a sequence control circuit 52 for reading out an optimum reference arc voltage for a welding current setting reference voltage from the storage circuit 51 in response to the setting signals to carry out the union control. Numeral 53 denotes a welding current setting element such as a potentiometer. A voltage E a thereacross is converted to a digital value E d by an A-D converter 54 and the digital signal is applied to the control unit 50. Numeral 55 denotes an arc voltage setting element such as a potentiometer which, in the union control mode, functions as a fine adjusting element for the arc voltage. Applied to the arc voltage setting element 55 in the individual control mode is a reference voltage E like in the prior art through a union/individual selection circuit 56, and in the union control mode an analog voltage E' a derived from a D-A converter 57 by converting a digital optimum arc voltage for the digital welding current setting provided by the control unit 50. FIG. 17 shows detail of the union/individual selection circuit 56. When a switch SW is thrown to a contact a, the individual control is carried out, and when the switch SW is thrown to a contact b, the union control is effected. The switch SW is actuated manually. Si represents a union/individual identification signal which supplies a high level signal to the control unit 50 in the individual control mode, and a low level in the union control mode.
In FIG. 16, E 1 represents the welding current setting reference voltage and E 2 represents the arc voltage setting reference voltage. SW represents a wire diameter signal which is produced by a wire diameter sense circuit 58 which senses the wire diameter by a contact voltage between a wire diameter selection roller of the motor and the wire. The wire diameter sense circuit 58 includes an A-D converter. The wire diameter may be set directly by a switch signal. Numeral 50 denotes a comparator for comparing a motor terminal voltage V M representing the actual speed of the motor with the reference voltage E 1 , and numeral 60 denotes a comparator for comparing the arc voltage V V with the reference voltage E 2 . S 1 and S 2 represent output signals of the comparators 59 and 60, respectively. Those signals are examined by the sequence control circuit 52 which produces a motor SCR control signal S M and an arc voltage SCR control signal S V .
The control unit 50 of FIG. 16 is preferably implemented by a microcomputer. In this case, the storage circuit 51 for storing the relations of the welding current and the arc voltage can be realized by a RAM. The sequence control circuit may comprises a ROM for storing a series of procedure programs and a CPU for executing the access to the RAM and other operations in accordance with the programs.
FIG. 18 shows a flow chart of a program previously stored in the ROM for the union/individual control when the control unit 50 is implemented by the microcomputer. Referring to FIG. 18, the operation of FIG. 16 is explained. In a step 1, the union/individual detection signal S i of the union/individual selection circuit 56 is read. In a step 2, the union or individual mode is determined based on the union/individual detection signal S i . If it is the union control mode, the process proceeds to a step 3 where the A-D converter 54 is activated to read the digital value E d of the welding current setting reference voltage E a and then the wire diameter signal S W (in digital form) is read. Based on the information E d and S W , the storage circuit 51 is accessed to determine the digital value E' d of the arc voltage setting reference voltage E' a from one or more stored relations of the welding current and the arc voltage. The D-A converter 57 is then activated to supply the arc voltage setting reference voltage E'.sub. a to the arc voltage setting element 55 through the union/individual selection circuit 56. On the other hand, if the individual control mode is determined in the step 2, the process moves to a step 4 to terminate the process without executing the above step. In the individual control mode, the voltage E is directly applied to the arc voltage setting element 55 by the union/individual selection circuit 56.
During the welding process, the output voltage E a from the welding current setting element 53 is applied to the comparator 59 as the welding current setting reference voltage E 1 , and the output voltage of the arc voltage setting element 55 is applied to the comparator 60 as the arc voltage setting reference voltage E 2 . The other inputs to the comparators 59 and 60 are the motor terminal voltage V M and the arc voltage V V , respectively. The sequence control circuit 52 reads in the output signals S 1 and S 2 of the comparators 59 and 60 at each zero-crossing point of the A.C. power supply and determines their polarities. Based on whether they are positive or negative, it produces the control signals S M and S V for advancing or retarding the firing phase angles of the motor SCR's and the arc voltage SCR's. A program for executing the above step may be stored in the ROM and is executed after the process of FIG. 18. In the above explanation, the polarities of the outputs of the comparators 59 and 60 are examined and based on the results the control signals S M and S V are produced to advance or retard the firing phase angles of the SCR's. Alternatively, the comparators 59 and 60 may detect a difference between E 1 and V M and a difference between E 2 and V V , those differences are converted to digital values by A-D converters, and the digital values are applied to the sequence control circuit 52 which produces the signals S M and S V indicating the firing timing of the SCR's.
FIG. 19 shows an overall configuration of an embodiment of an arc welder having a union/individual control circuit. In FIG. 19, numeral 61 denotes a motor speed feedback circuit which compares the terminal voltage V M of the wire feeding motor M with the reference voltage E 1 from the welding current setting element 53 to produce the motor terminal voltage feedback signal S 1 . It corresponds to the block 59 of FIG. 16. Similarly, numeral 62 denotes an arc voltage feedback circuit which compares the voltage V V of the welder torch electrode 4 with the reference voltage E 2 from the arc voltage setting element 55. It correspond to the block 60 of FIG. 16. Numeral 63 denotes an A-D/D-A converter which has a function of converting the welding current setting reference voltage E a of the welding current setting element 53 to the digital value E d and a function of converting the digital value E' d to the arc voltage setting reference voltage E' a . The A-D/D-A converter is thus a combination of the converters 54 and 57 of FIG. 16. Numeral 64 denotes a synchronizing signal detector which detects the zero-crossing points of the voltage waveform of the A.C. power supply 1. Numeral 65 denotes a block which corresponds to the control unit 50 of FIG. 16 and which may be implemented by a microcomputer. Numerals 2 and 5 denote the transformers, numeral 6 denotes the motor speed (or welding current) controlling SCR's, numeral 3 denotes the arc voltage controlling SCR's and numeral 58 denotes the wire diameter sense circuit.
As explained above in connection with FIG. 16, when the union control mode is selected by the output sign S i of the union/individual selection circuit 56, the control unit 65 of FIG. 19 reads in the wire diameter signal S W and the digital welding current setting E d prior to the welding process and produces the optimum digital arc voltage setting E' d based on the prestored relation of the welding current and the arc voltage. The corresponding analog voltage E' a is produced by the A-D/D-A converter 63 and applied to the arc voltage setting element 55 through the union/individual selection circuit 56. During the welding process, each time the synchronizing signal detection circuit 64 detects the zero-crossing point of the A.C. voltage waveform, the control unit 65 reads in the motor terminal voltage feedback signal S 1 and the arc voltage feedback signal S 2 to calculate the firing timings of the SCR's 3 and 6 for controlling the voltage and the current of the welder torch electrode 4 in order to produce the SCR firing control signals S M and S V . The operation of the control unit 65 in the welding process is not the subject of the present invention and hence it is not described in detail here.
In the embodiment shown in FIG. 16, two display means may be provided with one display means displaying the welding current setting voltage E a or its digital value E d while the other display means displaying the arc voltage setting digital value E' d or its analog value E' a for the welding current setting reference voltage E a read from the storage circuit 51 in order to display the optimum arc voltage for the welding current setting in the union control mode to an operator. Interlock means may be provided in the welding start operation so that the welding operation may be started only when the arc voltage setting corresponding to the welding current setting is read from the storage circuit 51 and the start of the welding operation is inhibited when the predetermined arc voltage setting is not obtained. This may be easily attained in the flow chart of FIG. 18 by adding a step "Retrieval Successed?" after the step "Retrieve and Read Stored Content". While the illustrated embodiment explains the case where the union control mode is performed by reading the optimum arc voltage for the welding current setting from the storage circuit 51, it should be understood that the present invention is equally applicable to the opposite case.
As is apparent from the foregoing description, the present invention provides the following advantages:
(1) The control circuit of the arc welder may be implemented by a microcomputer which can consolidate the complex circuits of the prior art. Accordingly, the number of components and parts can be reduced and the connecting wires can be shortened. Consequently, a highly reliable arc welder which is not influenced by external noise is attained. The change of the welding sequence or the addition of functions can be readily attained by modifying the program stored in the ROM. Thus, the problems encountered in the prior art are resolved.
(2) Since the setting position signals of the setting elements corresponding to the proper welding conditions are stored and they are used with the feedback stabilization control, the stored data are retrieved at the same conditions irrespective of the external disturbance such as fluctuation of the power supply voltage.
(3) The number of parts and components such as resistors in the union/individual control circuit can be substantially reduced. The troublesome adjustment of the potentiometers is not necessary. By using the optimum relations of the welding current and the arc voltage which are previously stored, the arc welder having the union control function which is more accurate than the prior art system using approximation control and less affected by the fluctuation of the power supply voltage is provided. | An arc welder is provided with a phase control circuit by rectifying elements to simplify the construction of the arc welder and improve the performance and operability. The arc welder is further provided with a storage control circuit to enable the retrieval of stored data of the same welding conditions. A union/individual control circuit is provided to eliminate troublesome adjustment of potentiometers. | 1 |
BACKGROUND OF THE INVENTION
1. Field of the Invention
This invention relates to a safety interlock device for preventing the accidental movement of a motor vehicle gear shift selector lever to a `drive` position, until a predetermined condition is satisfied, and more particularly to a gear shift lever lock mechanism which selectively inhibits movement of the gear shift selector lever to a drive position until an operator actuates the brake pedal.
2. Description of the Prior Art
It has long been recognized as a serious safety problem, that an automobile having an automatic transmission, may be inadvertently engaged to a drive position thereby resulting in a forward uncontrolled movement of the vehicle resulting in a serious personal and property damage. This can be particularly dangerous when the engine is freshly started and in a fast idle condition.
Each year, many accidents of this type occur when children who are left unattended in vehicles move the transmission gear shift selector lever to a "drive" or "reverse" position.
It is therefore, an object of the present invention to provide a transmission gear shift selector interlock mechanism which will prevent the accidental or inadvertent movement of an automobile gear shift selector lever to a "drive" or "reverse" position.
It is another object of the present invention to provide a gear shift selector interlock device of the type described, which cannot be moved from the lock position until the brake pedal has been actuated in a direction toward a braking position.
It is a further object of the present invention to provide a gear shift selector lever lock device which includes a control element located remotely from the lock device that must be actuated to operate the control element and permit the movement of the gear shift selector lever to a drive position.
It is yet another object of the present invention to provide a control system of the type described including a hydraulically, or mechanically energized spring, which moves a plunger between a position in the path of a gear shift selector lever, and a removed position out of the path, in response to actuation of a control element by the brake pedal.
It is another object of the present invention to provide apparatus which will enable a motor vehicle to be left safetly unattended, even with a small child in the vehicle.
Other objects and advantages of the present invention will become apparent to those of ordinary skill in the art as the description there of proceeds.
SUMMARY OF THE INVENTION
Apparatus for selectively preventing and permitting movement of a motor vehicle transmission gear shift selector mechanism to a drive position including a mechanism movable between a position in the path of the gear shift selector plate mechanism and a removed position out of the path of the gear shift selector plate mechanism when the brake pedal means is depressed.
In the mechanical variation, upon driver actuation of the brake pedal means a linkage leading to a brake interlock lever results in the movement of an interlock pin means in the direction of the fire wall, thereby releasing a "captured" interlock pin resting within a gear shift plate mounted upon the steering column sleeve. The gear shift lever is now free to be moved to a "drive" position resulting in engagement of the vehicle transmission.
In the hydraulic variation, upon driver actuation the brake pedal means, a pedal linkage leads to an increase in pressure within the brake fluid reservoir. An interlock feed line from the brake line beyond the brake fluid reservoir, leads to a hydraulic brake interlock cable, which then leads to an hydraulically-actuated interlock pin means. This interlock pin means pressure increase causes a piston to depress a spring thereby resulting in movement to a linkage to an interlock pin. The interlock pin then moves away from its "captured" position on the periphery of the gear shift plate mounted upon the steering column sleeve. The gear shift lever is now free to be moved to a "drive" position, resulting in engagement of the vehicle transmission.
BRIEF DESCRIPTION OF THE DRAWINGS
FIG. 1, is a fragmentary sectional side view of a motor vehicle incorporating the apparatus constructed according to the present invention.
FIG. 2, is a side view of the mechanical embodiment of the mechanical variation apparatus of the present invention.
FIG. 3, is a front view of the gear shift plate of the embodiment of FIG. 2.
FIG. 4, is a cross-sectional view of the interlock pin mechanism of the embodiment of FIG. 2.
FIG. 5, is a side view of the hydraulic embodiment of the apparatus of the present invention.
FIG. 6, is a cross-sectional view of the interlock pin mechanism of the embodiment of FIG. 5.
FIG. 7, is a front view of the gear shift plate of the embodiment of FIG. 5.
DESCRIPTION OF THE PREFERRED EMBODIMENT
FIG. 1 is a fragmentary, schematic, sectional, side view of a motor vehicle, incorporating the apparatus constructed according to the present invention for use with a motor vehicle. The motor vehicle is generally designated 10, including a frame generally designated 12, having a fire wall 14, separating an engine compartment 16, from a passenger compartment 18. The motor vehicle 10 also includes a brake hydraulic cylinder 15, as usually controlled by foot-actuated brake pedal 17, swingable about a pivot 19 as usual. Motor vehicle 10 is equipped with an automatic transmission, not shown.
FIG. 2 is a side view of the apparatus of the mechanical embodiment constructed according to the present invention.
The motor vehicle 10 (FIG. 1) includes a steering column assembly generally designated 20, having a stationary tubular steering sleeve 22, journaling a steering post 24, which is rotatable in a to and fro path about its axis by a steering wheel 26, fixed to one end of the steering post 24. The opposite end of the steering post 24 is coupled to motor vehicle steering tie rods, not shown, which function to turn the vehicle wheels in the normal manner when the vehicle operator turns the steering wheel 26. The steering column assembly passes through a suitable opening 23 provided in the fire wall 14. Mounted on the steering sleeve 22, via brackets 27, is an elongated shift bar 28, which is rotated about its longitudinal axis via a manually graspable and adjustable gear shift lever 30, fixed to the upper end thereof. FIG. 5, shows the lower articulated end of the shift bar 28 mounted to a lever arm 32, which is connected to a linkage 34, that is coupled to the vehicle transmission, generally designated by 36. By rotating the shift bar 28 about its axis through the movement of the shift lever 30, the operator s able to select the transmission gear most suitable for proper performance of the vehicle.
Automatic transmissions generally are designed to allow the gear shift selector lever 30 to be manually movable between the "park", "neutral", "drive" and "reverse" positions. The gear shift selector lever 30 is relatively easily moved to any of its designated positions. If the parking brake is not pre-set, and the gear shift selector lever 30 is moved in to a `drive` or `reverse` position, the vehicle will move in a forward or reverse direction depending on the gear selected. This may inadvertently be done by an adult or child who cannot subsequently control the vehicle, with an unexpected accident then resulting.
The apparatus of the mechanical embodiment constructed according to the present invention generally is designated 37a, and includes a gear shift plate 29, coupled to the upper end of the steering sleeve 22, via mounting bracket 38.
FIG. 3, is a front view of the gear shift plate of the mechanical embodiment shown in FIG. 2.
The gear shift plate 29 is a circular plate structure, with a circular central opening 31, through which the gear shift bar 28 projects. The shift plate 29 is fixably mounted, coplanar to, and immediately behind the steering wheel 26, via said mounting bracket 38.
Engraved on the periphery of the front surface of the gear shift plate 29, are gear position markings 35, which indicate the gear shift selector lever 30 controlled alignment positions for "park", "reverse", "neutral" and "drive" positions. The gear shift selector lever 30 is an elongated, thin rod, which is situated immediately behind the said shift plate 29 and coupled to the shift plate 29 and longitudinal shift bar 28. Movement of the gear shift selector lever 30, through an arcuate path around the longitudinal axis of the shift bar 28, allows the gear shift selector lever 30 to align the said pre-set markings 35 on the gear shift plate 29, with the index 29a, thereby indicating the correct position for the desired setting of said shift lever 30 when changing transmission gear positions.
Also located along the peripheral border of the gear shift plate 29, and oppositely opposed to the said gear position markings 35 on its front surface, are interlock pin holes 54, which serve to seat an interlock pin 47, which will prevent movement of the gear shift selector lever 30, until the brake pedal 17 is depressed by the operator. The operator actuation of the brake pedal 17 from its normal rest position, to a braking position toward the fire wall 14, around pivot point 19, causes the elongated rod-like brake interlock lever 42, of the present invention, which is coupled to the brake pedal linkage 17a, to also move in the direction of the fire wall 14, resulting in a simultaneous movement in the direction of the fire wall 14, of the incorporated spring-loaded interlock pin mechanism 44, situated at the upper end of the brake interlock lever 42.
FIG. 4 is a cross-sectional view of the interlock pin mechanism of the mechanical embodiment shown in FIG. 2. The interlock pin mechanism 44 consists of a tube-like interlock spring housing chamber 46, attached at its lower base point to the brake interlock lever 42, and oriented along its longitudinal axis, and containing an interlock pin spring 45, which occupies most of the interlock spring housing central chamber 46, of the said interlock pin mechanism 44. The interlock pin 47 is situated movably in said interlock spring housing chamber 46 with the pin-like upper end projecting through the upper cover of the interlock spring housing chamber 46. The base of said interlock pin 47, being a circular disc with its lower surface resting in contact with said interlock pin spring 45, and its upper surface the attachment point for the said pin-like projection.
The above described sequence of events following brake pedal 17 actuation, results in the interlock pin 47 being retracted from its "captured" position within one of the two interlock holes 54 located on the face of the circular shift plate 29. The interlock holes 54 are aligned such that the interlock pin 47 is "captured" within one of the two interlock holes 54, on the shift plate 29, when the gear shift selector lever 30 has aligned the index 29a with the engraved gear position markings 35, of either the "park" or "neutral" positions.
FIG. 5, is a side view of the apparatus of the hydraulic embodiment constructed according to the present invention. In the hydraulic embodiment of the present invention, operator actuation of the brake pedal 17, from its rest position to a "braking position" in the direction toward the fire wall 14, around the pivot point 19a, results in the movement of a brake pedal linkage 52, in the direction of the fire wall 14, causing the hydraulic brake line activator 51, to increase the brake fluid pressure within the hydraulic brake system cylinder 15. This increase in brake fluid pressure results in a pressure increase within the hydraulic feed line 43a leading to the hydraulic brake interlock cable 43. This in turn results in a fluid pressure increase within the hydraulic-operated interlock pin mechanism 48a housing chamber 48.
FIG. 6, is a cross-sectional view of the interlock pin mechanism of the hydraulic embodiment of FIG. 5.
This pressure increase further causes interlock pin piston 53 to move in the direction of the shift plate 29, thereby compressing spring 57. The linkage 58, oriented coplanar to shift plate 29, and coupled to the outer projecting end of piston 53, moves through an arcuate path around pivot point 59, resulting in the interlock pin 49, which is oriented at right angles to linkage 58, to rotate downward. This movement downward of the interlock pin 49, away from the periphery of shift plate 29, results in a "release" of the interlock pin 49 from its "captured" position within one of the shift plate interlock notches 55. This now allows an unimpeded arcuate movement of the gear shift selector lever 30 to any desired drive position, resulting in an engagement of the vehicle transmission.
FIG. 7, is a front view of the gear shift plate of the hydraulic embodiment of FIG. 5. The gear shift plate 29b of the hydraulic embodiment, is identical in all respects with that of the gear shift plate 29 of the mechanical variation, except for the replacement of interlock notches 55, instead of the interlock holes 54 that are found in the mechanical embodiment.
As in the above-described mechanical embodiment, the shift plate interlock notches 55, are aligned such that the interlock pin 49 is "captured" within one of the two interlock notches 55, on the shift plate 29b, when the gear shift selector lever 30 aligns the index 29a with the engraved gear position markings 35, of either the "park" or "neutral" positions.
It is to be understood that the drawings and descriptive matter are in all cases to be interpreted as merely illustrative of the principles of the invention, rather than as limiting the same in any way, since it is contemplated that various changes may be made in various elements to achieve like results without departing from the spirit of the invention or the scope of the appended claims. | An automobile transmission gear shift selector brake interlock mechanism, for selectively preventing inadvertent movement of a motor vehicle gear shift selector mechanism, between a non-drive `park` or "neutral" position, and a "drive" position, including a hydraulically, or mechanically-actuated interlock pin mechanism that is movable between a position in the path of the gear shift selector mechanism, and a removed position out of the path of the gear shift selector mechanism, when a motor vehicle brake pedal is actuated. | 8 |
[0001] This is a divisional of U.S. patent application Ser. No. 10/286,523, filed Nov. 1, 2002 and hereby incorporated by reference in its entirety.
BACKGROUND OF THE INVENTION
[0002] This invention relates generally to the art of film wrapping systems for use in wrapping objects with shrink wrap film, such as polyurethane wrapping film, and more particularly to improvements directed to dispensing such film from a film roll.
[0003] A wide variety of systems are known for wrapping packages in thermoplastic film. Some of these machines are known as L-sealers because they form “trim seals” utilizing a web of center folded film. More recent machines have utilized a continuous longitudinal sealer and a cross sealer which moves at approximately the velocity of the packages as they travel through the machine so that it is not necessary to stop the packages while performing the end sealing operation. Such prior art machines have generally been of three types. One type had a continuous side sealer and a complex series of multiple flighted end sealing jaws which were spaced for a particular product. This type required substantial set-up time for change in length of product to be wrapped. A second machine of this type, while making packages similar to those produced on an L-sealer worked by drawing film off a roll under tension, folding it around the product, drawing it past a hot knife side sealing mechanism and then formed the end seal with a moving end sealer.
[0004] A third type of machine had an overlapped longitudinal seal on the top or bottom of the wrapped packages. Since the overlap not only ran along the bottom of the packages but also ran halfway up both ends, the packages lacked the neat appearance and hence the sales appeal of the trim sealed packages as made on the L-sealers. Since many of the products so wrapped are sold in self-service retail stores, the appearance of the package has an important effect on the sales of the product. An additional disadvantage of the overlapped seal is that the width of the web of film must be precisely correct, requiring an exact width film for each size of product.
[0005] Shrink wrap packaging systems of these types process and wrap a variety of different products. Commonly, such products are of differing shapes, sizes and dimensions. For example, shrink wrap packaging systems may process and wrap a single compact disc (CD) package which is very thin or other consumer retail items which have a significantly greater height and larger vertical dimension.
[0006] One problem associated with most known shrink wrap packaging system is the difficulty to efficiently process and wrap a wide variety of packages and products, especially those having distinctly different dimensions and heights. For example, most known shrink wrap packaging systems utilize film which is provided on a roll in two plies with each ply being joined together by a longitudinal fold line. The two-ply film is dispensed from the supply roll typically in a direction generally perpendicular to the feed direction of the products to be wrapped. As the film is dispensed and delivered to a wrapping station of the shrink wrap packaging system, it is commonly inverted and reoriented to provide an opening for convenient access and entry of the products between the dual plies of the film. The film is reoriented by an upper and a lower film inverting rod or plow system. The upper and lower film inverting rods are positioned above and below, respectively, the feed conveyor which is advancing the products to be wrapped. Examples of such an arrangement are shown in U.S. Pat. Nos. 3,583,888; 3,583,889; 4,035,983; and 4,219,988, each of which are incorporated by reference herein.
[0007] The film inverter rods disclosed in the above-identified patents are each fixed relative to one another so that the spacing between the inverter rods is fixed. Recent advancements in the art of shrink wrap packaging systems have included adjustable film inverter rods to accommodate a variety of differing height products being wrapped. As such, the spacing between the film inverter rods may be adjustable.
[0008] However, one problem associated with adjustable film inverter rods is that the delivery of the two-ply film to the film inverter rods is often misaligned providing for poor geometry for the film being delivered to the film inverter rods once the spacing between the inverter rods is changed. Optimally the free edges of the upper and lower plies should be generally aligned with one another downstream from the film inverter rods for proper wrapping of the products and positioning of the side seam on the product. However, when the upper film inverter rod is moved relative to the lower film inverter rod for a different height product, the geometry of the film being delivered and processed at the wrapping station becomes misaligned. As a result, the film will not track properly and will not be in the required tubular configuration at the wrapping station. This requires readjustment and/or refeeding of the film through the various rollers, significant operator involvement and down time of the packaging system. The misalignment of the upper and lower plies of the film results in improperly wrapped products, side seals on the products which are located in a conspicuous or improper location, inefficient use or waste of the film wrapping material and other associated problems.
[0009] Therefore, a need exists in the shrink wrap packaging industry for a packaging system which can readily accommodate a wide variety of product configurations and heights without the above-described problems associated with known film delivery systems and wrapping operations.
SUMMARY OF THE INVENTION
[0010] These and other objectives have been achieved with this invention, which in one embodiment includes a film delivery unit for a shrink wrap packaging system. The film wrapping system includes a feed conveyor to delivery a series of products to a wrapping station. The wrapping station includes a pair of film inverter rods which are adjustable for spacing from one another to correspond to the height of the product being wrapped. A film delivery unit dispenses a supply of two-ply film in a direction generally perpendicular to the feed direction of the products. The two-ply film is inverted by the inverter rods at the wrapping station where the products are inserted between the plies of the film. The system includes a film inverter rod adjustment mechanism to adjust the spacing between the rods.
[0011] The system also includes a film delivery unit adjustment mechanism to adjust a position of the film delivery unit and the film being delivered to the wrapping station as a function of the spacing between the film inverter rods and, consequently, the height of the product being wrapped. In one embodiment of this invention, the film delivery unit adjustment mechanism moves the film delivery unit and the supply of film upstream in the feed direction relative to the film inverter rods for larger height products and downstream for smaller height products. Additionally, the system in another embodiment includes an adjustable roller positioned between the film delivery unit and the wrapping station to deliver the film to the wrapping station at a desired height relative to the position of the film inverter rods.
[0012] The shrink wrap packaging system also includes a side seal mechanism and an end seal mechanism each located downstream in the feed direction from the wrapping station to join the first and second plies together and enclose each of the products in individually wrapped packages. A heat shrink tunnel in one embodiment is located downstream from the sealing mechanisms to heat the film and thereby shrink it around the product as is well known in the industry.
[0013] As a result of the film delivery unit and associated adjustment mechanism according to this invention, a variety of product configurations and heights can be conveniently and efficiently wrapped while adjusting the spacing between the film inverter rods without fouling the geometry of the film delivery system and thereby avoiding the associated problems and disadvantages of shrink wrap packaging systems in the prior art.
BRIEF DESCRIPTION OF THE DRAWINGS
[0014] The objectives and features of the invention will become more readily apparent from the following detailed description taken in conjunction with the accompanying drawings in which:
[0015] [0015]FIG. 1 is a top view of a film wrapping system and associated method according to one embodiment of this invention;
[0016] [0016]FIG. 1A is a view similar to FIG. 1 of a portion of the wrapping system with a film delivery unit re-positioned;
[0017] [0017]FIG. 2 is a schematic view of a series of products as they travel through the system and in addition showing a film folding operation;
[0018] [0018]FIG. 3 is a perspective view of the film delivery unit and a product wrapping station of the system of FIG. 1;
[0019] [0019]FIG. 4 is schematic end view of the components of FIG. 3 with a portion of the film delivery unit removed to show the film path; and
[0020] [0020]FIG. 5 is plan view of the film delivery unit of FIG. 3.
DETAILED DESCRIPTION OF THE INVENTION
[0021] Referring now to FIG. 1, a top view of an exemplary automatic high-speed film packaging system 10 according to one embodiment of this invention is shown. The system 10 generally includes a feed conveyor 12 , a film delivery unit 14 , a wrapping station 16 , a side sealer 18 , an end sealer 20 , associated downstream conveyor(s) 22 and a heat shrink tunnel 24 . Products P to be wrapped in film 26 enter the system 10 via a feed conveyor 12 . The conveyor 12 delivers the spaced-apart and generally aligned products P to the wrapping station 16 where a folded film 26 from a film roll 28 in the film delivery unit 14 surrounds each product P. The folded film 26 enveloping each product P is sealed at its free edges 30 , 30 by the side sealer 18 to form a tube of film 26 enclosing the spaced products P. The film salvage 32 (FIG. 2) at the sealed edge 34 is severed and removed. The film 26 between the adjacent products P is sealed and severed at the end sealer 20 to produce individual sealed packages of the product P.
[0022] The system 10 wraps a product P in a flexible plastic film 26 in which the travel of the product P is essentially continuous through the system 10 in a feed direction indicated by arrow A. The film 26 may be any one of a variety of films well known in the art and is supplied to the system 10 as a folded web at right angles to the feed direction of the product P (shown in FIGS. 1 and 2) through the system. The film 26 is provided to upper and lower inverter rods 36 a , 36 b of the wrapping station 16 where the film 26 is redirected and turned inside out to travel in the feed direction with the products P delivered by the feed conveyor 12 .
[0023] The feed conveyor 12 pushes products P into the wrapping station 16 to cause them to be enclosed by the folded film 26 supplied by film delivery unit 14 on the top, bottom, and one side of the product P with the other side of the product P adjacent to the free edges 30 , 30 of the folded film 26 being open initially. The product P thus enclosed in the web of film 26 travels with the film 26 past the side sealing mechanism 18 in FIG. 1 which seals the two free edges 30 , 30 of the folded film 26 together to form a continuous tube of film which envelops the succession of products P which are being fed into the system 10 by feed conveyor 12 . The side sealer 18 also severs the excess width 32 of film 26 from the tube and this salvage 32 is removed by a salvage accumulator 38 , such as a vacuum or other take-up mechanism.
[0024] As the product P progresses further through the system 10 , the end sealing mechanism 20 seals the trailing edge 40 of each package while simultaneously sealing the leading edge 42 of the succeeding package in the system and it also severs one package from the other while the packages are traveling without stopping through the system 10 . The end seal mechanism 20 is so designed that it travels a short distance with the product P at substantially the same velocity while the seal is being made. After the seal has been made, the sealing mechanism 20 releases from the film 26 and returns to its original position to repeat the transverse seal for the next product. The wrapped product may then be conveyed through the shrink tunnel 24 for shrinking of the film around the product. While exemplary embodiments of the side sealer 18 , end sealer 20 and shrink tunnel 24 are shown and described herein as part of the system, specific models or embodiments of these components could readily be varied or changed as known by one of ordinary skill in this art without departing from the scope of this invention.
[0025] Because the product P being wrapped in the film proceeds through the system 10 at a substantially uniform velocity, the system 10 is capable of operating at film web speeds as high as 120 feet per minute although 60 to 100 feet per minute is a more typical speed. The system 10 is capable of wrapping in excess of one product P per second.
[0026] [0026]FIG. 2 shows the various stages of wrapping of successive products P 1 -P 5 with the plastic film 26 as the products proceed through the system 10 . Product P 5 is shown in FIG. 2 as being partially covered by the folded film 26 as it passes between the inverter rods 36 a , 36 b . Product P 4 is shown exiting the side sealer 18 with the salvage 32 of the film 26 being separated from the side sealed package P 4 and being collected by salvage accumulator 38 . The side sealer 18 produces the side seal 34 that completes the tube envelope of relatively loose plastic film 26 around the products P.
[0027] The end sealing mechanism 20 produces a trim seal between the packages P 3 and P 2 . The end sealing mechanism 20 also severs the film 26 to provide product P 3 with a leading edge 42 and product P 4 with a trailing edge 40 . The product P 1 is shown as it exits from the heat shrink tunnel 24 where the loose fitting film envelope is shrunk to form a tight fitting film cover. The system 10 is designed to accommodate a variety of product heights and configurations as shown by product P 3 having a greater height than the other products. It will be appreciated that FIG. 2 is schematic and the relative positions of the products P 1 -P 5 and associated components of the system 10 have been adjusted for simplification.
[0028] The component parts and the assembly in combination of the continuous high-speed wrapping system 10 of FIG. 1 will now be discussed in detail, focusing in particular on the wrapping station 16 and the film delivery unit 14 .
[0029] Preferably, the product P is centered with respect to the feed conveyor 12 by means of guides (not shown) as is readily understood by those skilled in this art. The film 26 is folded about a longitudinal fold 44 thereby forming upper and lower plies 46 a , 46 b in which each ply has a free edge 30 opposite from the fold line 44 . Commonly, the two-ply folded film 26 is provided on the supply roll 28 . Alternatively, single ply film may be provided on a supply roll and subsequently folded into the described two-ply configuration as is well known in the art.
[0030] As shown particularly in FIGS. 1, 2 and 4 , the two-ply film 26 is delivered from the supply roll 28 by the film delivery unit 14 in a direction indicated by arrow B generally perpendicular to the feed direction (arrow A) of the products P. As the film 26 enters the wrapping station 16 , each ply 46 a , 46 b is guided around one of the film inverter rods 36 a , 36 b and thereby redirected approximately 90° to travel in the feed direction of arrow A. The film inverter rods 36 a , 36 b are oriented approximately 45° with respect to the feed direction. In addition to being redirected, the film 26 is inverted by the film inverter rods such that confronting inner first faces 48 , 48 of the film 26 provided by the film delivery unit 14 are inverted so that previously outer second faces 50 , 50 of the plies 46 a , 46 b of the film 26 are juxtaposed to each other and around the product P downstream from the film inverter rods 36 a , 36 b.
[0031] As shown particularly in FIGS. 3 and 4, each film inverter rod 36 a , 36 b is joined to a pair of mounting rods 52 , 54 to form a generally triangular configuration. Mounting rod 52 is oriented generally parallel to the feed direction; whereas, mounting rod 54 is oriented generally perpendicular to the feed direction. An inclined guide tab 56 is mounted proximate the intersection of each film inverter rod 36 and the associated mounting rod 52 . The intersection between each film inverting rod 36 and the associated mounting rod 52 provides a reference point R which will be discussed herein below.
[0032] Film inverter rods 36 a , 36 b and the associated mounting rods 52 , 54 are mounted to a hub 58 a , 58 b , respectively. The hub 58 b for the lower film inverter rod 36 b is fixed beneath the feed conveyor 12 . The hub 58 a for the upper film inverter rod 36 a is mounted on a film inverter rod adjustment mechanism 60 to adjust a spacing S between the upper and lower film inverter rods 36 a , 36 b in a direction generally perpendicular to the feed direction (i.e., vertically) to accommodate products P of differing heights. The film inverter rod adjustment mechanism 60 in one embodiment includes an operator hand wheel 62 mounted atop a threaded rod 64 to rotate the rod 64 . The hub 58 a includes a threaded aperture 66 engaged with the threaded rod 64 as well as two additional apertures 68 , 68 through which guide rods 70 , 70 project. In operation of the system 10 , the operator rotates the hand wheel 62 in the appropriate direction to raise or lower the upper film inverter rod 36 a so that the upper ply 46 a of the film 26 is positioned slightly above the top upper surface of the product P being wrapped. The upper and lower film inverter rods 36 a , 36 b , as well as the film inverter rod adjustment mechanism 60 , are mounted to a block 72 which is supported on a platform 74 underlying the lower film inverter rod 36 b as well as the feed conveyor 12 . A frame 76 supports the wrapping station 16 , associated film inverter rod components as well as the film delivery unit 14 as shown in FIG. 3. The downstream conveyors 22 and associated components are not shown in FIG. 3 to provide a better view of the components in the wrapping station 16 and the film delivery unit 14 .
[0033] The film delivery unit 14 , as shown generally in FIGS. 3-5, is mounted adjacent to the wrapping station 16 in a direction generally perpendicular to the feed direction. The film delivery unit 14 supplies film 26 from the supply roll 28 to the wrapping station 16 . The supply roll 28 is supported by a cradle assembly 78 of the film delivery unit 14 . The cradle assembly 78 includes a pair of spaced cradle rollers 80 , 80 mounted for rotation between spaced end plates 82 , 82 of the cradle assembly 78 . The supply roll 28 is positioned atop the cradle rollers 80 , 80 and between a pair of film roll retainer posts 84 a , 84 b . Preferably, the gap between the film roller retainer posts 84 a , 84 b is adjustable to accommodate supply rolls 28 of different lengths. Specifically, in one embodiment, the downstream film roll retainer post 84 b is joined to a bracket 86 that is secured by a set screw 88 in a slot 90 of front frame member 92 in the cradle assembly 78 . To adjust the spacing between the film roll retainer post 84 a , 84 b for different length supply rolls 28 , the operator would loosen the set screw 88 and slide the bracket 86 and associated film roll retainer post 84 b along the slot 90 to the appropriate position to capture the supply roll 28 between the film roll retainer post 84 a , 84 b.
[0034] Referring to FIG. 4, the path of the film 26 from the supply roll 28 through the delivery unit 14 and to the wrapping station 16 is shown. The supply roll 28 rotates on the cradle rollers 80 , 80 and the film 26 is fed around a lower deflecting roller 94 toward a film splitter insert 96 . The film splitter insert 96 advantageously separates or loosens the two film plies 46 a , 46 b from one another to avoid difficulty downstream in the film path in case the film 26 has an excessive build-up of static electricity, is particularly tacky or otherwise resistant to having the plies 46 a , 46 b separated. After the film splitter insert 96 , the film 26 travels between a pair of nip rollers 98 , 100 and downwardly around a dancer roller 102 . The lower nip roller 98 is preferably rubber and is coupled to a belt drive 104 trained around the output shaft of a motor 106 . The motor 106 rotates the rubber nip roller 98 thereby pulling the film 26 from the supply roll 28 . The motor 106 which drives the roller 98 must turn the supply roll 28 in a direction to provide film 26 to the wrapping station 16 . The motor 106 must at all times provide film 26 in excess of the maximum speed of the feed conveyor 12 to ensure minimum tension of the film 26 as it passes over the film inverter rods 36 a , 36 b . The dancer roller 102 is coupled to a tension arm 108 for pivotal movement about a tension pivot 110 to maintain tension on the film 26 . If slack in the film 26 develops because of an interruption in the flow of products P, for example, the tension arm 108 is coupled to a controller (not shown) for the motor 106 to interrupt the dispensing of the film 26 until additional film is required by the wrapping station 16 . As such, film tension is controlled by the dancer roller 102 through the tension arm 108 in association with the control of the motor 106 .
[0035] The upper nip roller 100 may include a number of pins or spikes 112 to perforate the film 26 passing between the nip rollers 98 , 100 as is customary in the shrink wrap industry. The film 26 passes around an intermediate deflecting roller 114 and an upper deflecting roller 116 before exiting the film delivery unit 14 . The various rollers 94 , 98 , 100 , 102 , 114 and 116 extend between a pair of spaced sidewalls 156 , 156 of the film delivery unit 14 .
[0036] The system 10 includes a film delivery height adjustment roller 118 positioned between the film delivery unit 14 and the wrapping station 16 . The roller 118 is mounted between a pair of arms 120 , 120 which are coupled to corresponding links 122 mounted to the frame 76 . Advantageously, the position of the arms 120 , 120 and subsequently the position of the roller 118 is adjustable to deliver the film 26 to the wrapping station 16 at an appropriate height relative to the position of the film inverter rods 36 a , 36 b . Preferably, the vertical position of the roller 118 is equal distance between the upper and lower film inverter rods 36 a , 36 b . Since the spacing S between the film inverter rods is adjustable, the height of the film delivery roller 118 is likewise adjustable to provide for proper positioning relative to the film inverter rods 36 a , 36 b . The arm 120 supporting the roller 118 includes a set screw 124 which is captured within an arcuate slot 126 in a guide plate 128 . Adjustment of the roller 118 height is accomplished by the operator by loosening the set screw 124 and pivoting the arms 120 coupled to the roller 118 upwardly or downwardly as desired and then resecuring the set screw 124 with the roller 118 in the appropriate position approximately midway between the upper and lower film inverter rods 36 a , 36 b . As the film 26 passes around the roller 118 , the two plies 46 a , 46 b are separated and guided by the respective film inverter rods 36 a , 36 b to surround the product P on the conveyor 12 .
[0037] As shown particularly in FIGS. 3-5, the film delivery unit 14 is movably mounted relative to the frame 76 on a pair of spaced generally tubular rails 130 , 130 . In one embodiment, each of the rails 130 extends generally in the feed direction and is supported on one of a pair of spaced generally U-shaped brackets 132 mounted to a lower portion of the frame 76 . The film delivery unit 12 moves on the rails 130 , 130 by a series of support roller bearings 134 . Each support roller bearing 134 is mounted for rotation between a pair of downwardly depending support plates 136 , 136 mounted on a lower surface of the film delivery unit 14 . Preferably, each pair of support plates 136 , 136 has two upper and one lower support roller bearing 134 mounted therebetween for rotation along the respective rail 130 . The support roller bearings 134 are positioned as generally shown in FIG. 5 to provide support and stable movement along the rails 130 , 130 of the film delivery unit 14 as required.
[0038] The position of the film delivery unit 14 is adjustable on the rails 130 , 130 in a direction generally parallel to the feed direction in via a film delivery unit adjustment mechanism 138 . The film delivery unit adjustment mechanism 138 according to one embodiment of this invention provides for proper positioning and delivery of the film 26 to the wrapping station 16 as a function of the spacing S between the film inverter rods 36 a , 36 b . Specifically, in one embodiment, the film delivery unit adjustment mechanism 138 includes an adjustment knob 140 mounted for rotation and projecting from casing 142 mounted to the frame 76 . The adjustment knob 140 is mounted for rotation relative to the casing 142 and is coupled to a threaded rod 144 which is engaged in a threaded aperture 146 in one of the sidewalls 156 of the film delivery unit 14 . As such, rotation of the adjustment knob 140 and the threaded rod 144 attached thereto moves the film delivery unit 14 in a lateral direction, as shown in FIG. 5, or upstream/downstream relative to the feed direction. Proper positioning of the film delivery unit 14 and the supply roll 28 according to this invention provides for accurate and precise film 26 geometry as it is delivered through the film delivery unit 14 to the wrapping station 16 . Preferably, the film inverter rods 36 a , 36 b in the wrapping station 16 remain stationary as the position of the film delivery unit 14 is adjusted.
[0039] In particular, it has been determined that the relative position of the film inverter rods 36 a , 36 b in the feed direction compared to the leading or upstream edge 148 of the film supply roll 28 mounted on the delivery unit 14 is important to maintain proper geometry of the film 26 being dispensed from the supply roll 28 through the delivery unit 14 and applied at the wrapping station 16 to the products P on the conveyor 12 . The relative position of the upstream edge 148 of the supply roll 28 in comparison to the reference point R on the film inverter rods 36 a , 36 b is utilized to provide for proper film delivery geometry.
[0040] As the spacing S between the upper and lower film inverter rods 36 a , 36 b is adjusted to accommodate different height products P, movement of the film delivery unit 14 in a direction generally parallel to the feed direction is required to maintain proper film delivery geometry. For products P which are extremely thin and having little or no height such as a CD lying generally flat on the feed conveyor 12 , the reference point R on the film inverter rods 36 a , 36 b is generally aligned with the upstream edge 148 of the supply roll 28 on the film delivery unit 14 . However, the film delivery unit 14 must be moved in a direction generally parallel to the feed direction as the spacing S between the film inverter rods 36 a , 36 b is adjusted to accommodate different height products P.
[0041] In operation, the spacing S between the film inverter rods 36 a , 36 b is adjusted to accommodate the product P height. Once the film inverter rods 36 a , 36 b are so adjusted, the position of the film delivery height adjustment roller 118 is likewise set by the operator to be approximately equal distance between the film inverter rods 36 a , 36 b . The film delivery unit 14 is then moved relative to the reference point R on the film inverter rods 36 a , 36 b to provide for proper alignment, geometry and delivery of the film 26 to the wrapping station 16 . According to one embodiment of this invention, the film delivery unit 14 is moved via the adjustment knob 140 along the rails 130 one-half inch to adjust for each inch in package height to establish the correct film delivery geometry. The film inverter rods 36 a , 36 b at the wrapping station 16 should remain stationary as the film delivery unit 14 position is adjusted. For each inch increase in product height, the position of the film delivery unit 14 is adjusted one-half inch in the upstream direction. Conversely, for each inch decrease in package height or spacing between the film inverter rods 36 a , 36 b , a half-inch movement of the film delivery unit 14 in the downstream feed direction is required for correct film geometry.
[0042] For example, as shown in FIG. 1, the relative position of the edge 148 of the supply rod 28 compared to the reference point R provides appropriate tracking and film 26 delivery geometry for a product such as P 3 of FIG. 2. However, for a product P 4 of lesser height, the spacing S is decreased and the edge 148 is adjusted with the film delivery unit 14 downstream parallel to the feed direction to a position relative to reference point R as shown in FIG. 1A.
[0043] A product height indicator 150 is provided to indicate the spacing S between the film inverter rods 36 a , 36 b . A product height adjustment scale 152 is mounted on the frame 76 and an indicator 154 moves with the film delivery unit 14 so that the operator may accurately position the film delivery unit 14 relative to the inverter rods 36 a , 36 b . While the adjustment mechanisms 60 and 138 , as well as the positioning of roller 118 , are shown and described herein as being independent from each other, alternative embodiments of this invention include automatic adjustment of the positions of the film roll 28 and/or roller 118 in response to changes to the spacing S.
[0044] An important feature of this invention is the positioning of the film delivery unit 14 and the supply roll 28 thereon relative to the film inverter rods 36 a , 36 b in the feed direction. According to one embodiment of this invention, the film delivery unit adjustment mechanism 138 adjusts the position of the film delivery unit 14 in the upstream or downstream directions. Alternatively, the position of the film inverter rods 36 a , 36 b relative to the feed direction may be adjusted by movement of the block 72 relative to the frame 76 and supply roll 28 to provide for the appropriate relative position between the film inverter rods 36 a , 36 b and the supply roll 28 mounted on the film delivery unit 14 . Nevertheless, as a result of this invention, proper film delivery geometry from the supply roll to the film inverter rods can be easily and efficiently obtained in conjunction with the adjusted spacing between the film inverter rods to accommodate varying height products without fouling the delivery of the film along the film path and maintaining alignment of the free edges of the plies of the film wrapped around the products.
[0045] From the above disclosure of the general principles of the present invention and the preceding detailed description of at least one preferred embodiment, those skilled in the art will readily comprehend the various modifications to which this invention is susceptible. Therefore, I desire to be limited only by the scope of the following claims and equivalents thereof. | An automatic high-speed wrapping system for wrapping packages in heat sealable thermoplastic film includes a film delivery unit wherein the film is dispensed and wrapped around the packages at a high rate of speed as the packages travel through the system. The packages travel continuously in a straight line through the system and are delivered at the input end of the system by a feed conveyor into a wrapping station where the packages are surrounded by the film, thence to the side sealing mechanism which forms a seal while severing the salvage from the packages, then into an end sealing mechanism where both ends of the packages are sealed and the film web connecting succeeding packages is severed. The film is delivered to the wrapping station in two plies and subsequently inverted for wrapping around the products. The positions of the wrapping station and film delivery units are adjustable to efficiently accommodate a variety of product heights while providing proper film delivery geometry. | 1 |
CO-PENDING APPLICATION
The present Nonprovisional patent application is a Continuation application of U.S. Provisional Patent Application Ser. No. 61/805,221 titled “Lid-actuated Toilet Flusher” and filed on Mar. 26, 2013. The present Nonprovisional patent application claims the priority date of Provisional Patent Application Ser. No. 61/805,221. Furthermore, Provisional Patent Application Ser. No. 61/805,221 is hereby incorporated into the present Nonprovisional patent application in its entirety and for all purposes.
FIELD OF THE INVENTION
The present invention relates generally to plumbing fixtures and more particularly to toilets.
BACKGROUND OF THE INVENTION
The prior art includes flushing toilets. In the past, it has been suggested to modify such toilets to flush in response to a lowering of the toilet bowl lid toward the bowl of the toilet. This dynamic both reduces air contamination creating by a release of material from within the bowl of the toilet and generated during a flush process, and reduces the incidence of users later sitting down on the toilet when the seat is up.
The prior art systems, however, are not optimally adaptable to prior art toilets and preexisting toilet designs. There is thus a long felt need for a device designed to a lowering of the toilet bowl lid acts to trigger a flushing action of the instant toilet and that may be integrated into a wide variety of prior art toilets and toilet designs, including new toilet builds. It is an object of the present invention to couple the lid of a toilet to a mechanism of the same toilet to cause the toilet to flush upon a lowering of the toilet seat.
SUMMARY OF THE INVENTION
Towards this object and other objects of the present invention that will be made obvious in light of the present disclosure, an apparatus is provided that detachably couples a toilet bowl lid with a valve control, whereby motion of the toilet bowl lid causes the valve control to release water into a bowl of the toilet and thereby flush out at least most of the fluid and contents of the toilet bowl.
In a first preferred embodiment of the present version, an arm is detachably attachable with a lid element. The arm includes a flexible member joined with a coupling end. The coupling end and the lid element are detachably attachable and are magnetically attracted together in certain alternate preferred embodiments of the present invention. The toilet element is preferably securely and durably attached to the toilet bowl lid.
The flexible member is coupled with a pull chain of the prior art flush toilet within a water tank of the toilet and the coupling end is detachably coupled with the lid element when the toilet bowl lid is in an open position relative to the toilet bowl.
It is understood that the prior art pull chain is typically attached to a prior art flapper, and that the flapper is rotatably coupled within the water tank, wherein the flapper is adapted to alternately permit and block water from proceeding from flowing from the water tank and into the toilet bowl via a toilet tank drain.
The arm is dimensioned such that the arm and the flush chain in combination do not allow the coupling end to maintain contact with the lid element when the toilet bowl lid is lowered to substantively cover the toilet bowl (i.e. when the toilet bowl lid is in a lowered or down position relative to the toilet bowl).
In typical use, the coupling end is detachably coupled to the toilet bowl lid when the toilet bowl lid is substantively upright and rotated away from the toilet bowl. As a user lowers and rotates the toilet bowl lid toward the toilet seat, the arm is pulled toward an outside of the water tank of the toilet, whereby the flush chain is pulled substantively upwards within toilet tank and the flush chain rotates the flapper and the toilet tank drain is exposed. A water volume flows from the water tank and into the toilet bowl as the flapper is rotated to expose the toilet tank drain. The coupling of the flapper to the toilet tank and the flush chain limit the extent to which the arm can be pulled toward the outside of the water tank. The arm is preferably sized to cause the arm coupling element and the lid element to be pulled apart prior to the lowering of the toilet bowl lid fully into the down position. When the toilet bowl lid is later raised to a fully open position relative to the toilet bowl, the arm coupling end and the lid element are sized, adapted and positioned to cause the arm coupling end and the lid element to resume a detachable coupling.
In another alternate preferred embodiment of the present invention, a guide element is provided that guides and supports the arm flexible member in movement and positioning of the flexible member relative to the prior art flush chain, flapper and toilet tank. The guide element may be adapted to be coupled onto a wall of the toilet water tank and is adapted to support a curving of the arm flexible member as instantiated between the toilet tank wall and the flush chain.
In still other various alternate embodiments of the present invention, the arm coupling element may be or comprise a ferromagnetic material and the lid or portion of the lid may be or comprise a magnet or magnet material, whereby the arm coupling element and the lid are detachably attachable by magnetic force.
In yet other various alternate embodiments of the present invention, the arm coupling element may be or comprise a magnet or magnetic material and the lid or portion of the lid may be ferromagnetic or comprise a ferromagnetic material, whereby the arm coupling element and the lid are detachably attachable by magnetic force.
In a yet alternate preferred embodiment of the present version, a second arm is both (a.) durably attached to a flow valve of a tankless toilet comprising a flushometer, and (b.) detachably attached with a second toilet bowl lid. Movement of the second toilet bowl lid toward a toilet bowl of the tankless toilet pulls the second arm and thereby causes the flow valve to release water from a pressurized water source and into a toilet bowl of the tankless toilet. When the second toilet bowl lid is later raised to a fully open position relative to the toilet bowl of the tankless toilet, the arm coupling end and the second toilet bowl lid are sized, adapted and positioned to cause the arm coupling end and the second toilet bowl lid to resume a detachable coupling.
BRIEF DESCRIPTION OF THE DRAWINGS
FIG. 1 is a drawing of a cutaway view of a prior art toilet having a standard flush handle and a water tank (“toilet tank”), with a toilet tank lid removed, within which the present invention is not installed.
FIG. 2 is a drawing of a cutaway view of the toilet of FIG. 1 , with the toilet tank lid and the standard flush handle removed, within which a preferred embodiment of the present invention comprising an actuator linkage with a guide body installed.
FIG. 3A shows a side view of the toilet of FIG. 1 and a cutaway view of the toilet tank of FIG. 1 with the toilet bowl lid open and the actuator linkage of FIG. 2 in the ready-to-use state.
FIG. 3 b shows flushing of the toilet of FIG. 1 initiated with the flap open and the actuator linkage of FIG. 2 in contact with the toilet bowl lid as the toilet bowl lid is beginning to be lowered.
FIG. 3C shows the toilet of FIG. 1 releasing after flush, which the flap is open and the actuator linkage of FIG. 2 has separated from the toilet bowl lid of the toilet as the toilet bowl lid is lowered past a certain point.
FIG. 3D shows the toilet bowl lid of the toilet of FIG. 1 in a down position and ready for next use, while the actuator linkage of FIG. 2 is at rest and the flapper on the tank is closed.
FIG. 4A shows two rear spacers resting on top of the toilet tank of FIG. 1 , supporting the tank cover allowing space for the actuator linkage of FIG. 2 to move relative to the toilet tank of the toilet of FIG. 1 when in use.
FIG. 4B shows the optional use of decorative tape to cover the gap between the toilet tank and the lid of the toilet of FIG. 1 when the spacers and the guide body of FIG. 2 are installed on the tank of the toilet of FIG. 1 .
FIG. 5 is a line drawing of the actuator linkage of FIG. 2 in side view as the actuator linkage is shown in the vertical orientation, as it will rest on the top of the toilet tank of the toilet of FIG. 1 .
FIG. 6 is a front view of the actuator linkage and the guide body of FIG. 2 .
FIG. 7 shows several integral parts of the actuator linkage of FIG. 2 and several accessory spacers needed for installation, as well as optional decorative tape to cover the gap between the toilet tank and the tank cover when the actuator linkage is installed.
FIG. 8A is a perspective of an alternate flushometer toilet.
FIG. 8B is a perspective of the flushometer toilet with an alternate embodiment of the present invention.
FIG. 8C is a cut away detailed view of the flushometer toilet with an alternate embodiment of the present invention of FIG. 8B .
FIG. 9A is a top view of a third alternate embodiment of the invented linkage assembly that includes a thin plastic strip within a third arm.
FIG. 9B is a top view of a fourth alternate embodiment of the invented linkage assembly that includes a cord within a fourth arm.
FIG. 9C is a top view of a fifth alternate embodiment of the invented linkage assembly that includes a cable within a fifth arm.
FIG. 9D is a top view of a fourth alternate embodiment of the invented linkage assembly that includes a wire within a sixth arm.
The figures depict various embodiments of the present invention for purposes of illustration only. One skilled in the art will readily recognize from the following discussion that alternative embodiments of the structures and methods illustrated herein may be employed without departing from the principles of the invention described herein.
DETAILED DESCRIPTION
Wherever possible, the same reference numbers will be used throughout the drawings to refer to the same or like parts. The components in the drawings are not necessarily to scale.
Referring now generally to the Figures and particularly to FIG. 1 , a standard prior art gravity toilet 10 includes a toilet tank 12 coupled with a flush handle 14 that is attached through a hole 15 of a front tank wall 12 A, as shown in FIGS. 4 a and 4 B, toward the top of the toilet tank 12 , to a drain pull chain 18 . The drain pull chain 18 is further connected to a flapper 16 that rests over and alternately covers and releases the toilet tank drain 19 at the bottom of the toilet tank 12 . Manual rotation of the flush handle 14 pulls up the drain pull chain 18 . This in turn pulls the flapper 16 up, so that water in the toilet tank 12 drains out of the toilet tank 12 and into a toilet bowl 22 to flush out contents of the toilet tank 12 . The toilet tank 12 comprises four walls 12 A, 12 B, 12 C & 12 D.
Referring now generally to the Figures and particularly to FIG. 2 , the method of the present invention removes and replaces the prior art flush handle 14 with an actuator linkage 24 . The removal of the flush handle 14 leaves exposed the tank hole 15 , which can optionally be covered by a sticker (not shown).
A first end 24 A of the actuator linkage 24 is coupled to the drain pull chain 18 in place of the flush handle 14 . A second end 24 B of the actuator linkage 24 coupled with a permanent magnet 30 . The magnet 30 may be or comprise a SUPER MAGNET™ neodymium disc magnet marketed by Master Magnets, Inc. of Castle Rock, Colo. or other suitable magnet known in the art. The actuator linkage 26 may be formed to friction fit the magnet 30 into the actuator linkage second end 24 B.
A toilet tank clip 26 of a linkage guide body 28 that rests on the top of the front toilet wall 12 A. The linkage guide body 28 is a single piece construction that guides and supports the actuator linkage 24 and couples with a toilet tank front wall 12 A. The actuator linkage 24 includes of a flat, flexible plastic ribbon 24 C that moves forward over the linkage guide body 28 to enable a pulling of the drain pull chain 18 , which in turns enables a lifting of the flapper 16 so that the toilet tank 12 can empty water into the toilet bowl 22 to cause a flushing of the toilet bowl 22 .
After the toilet bowl lid 20 is separated from the magnet 30 , the actuator linkage 24 moves back into the toilet tank 12 under the influence of gravity, whereupon the flapper 16 lowers to close over and cover the toilet tank drain 19 and thereby stopping water from proceeding from the toilet tank 12 to the toilet bowl 22 . The linkage guide body 28 supports the weight of the actuator linkage 26 through out the usage cycle of the method of the present invention. The linkage guide body 28 is preferably sufficiently rigid to support the mass of actuator linkage 26 without deforming greater than 5 degrees, and may be made of a rigid material such as a metal a metallic compound, an acrylic plastice, and/or comprise other sufficiently rigid and durable materials known in the art.
Between flushing cycles, the second end 24 b and the magnet 30 of the actuator linkage 24 protrudes outside of toilet tank 12 towards the front of the toilet 10 and preferably beyond the front toilet tank wall 12 A. This positioning of the magnet 30 of the actuator linkage 24 beyond the end of the toilet tank front wall 12 A enables the magnet 30 to engage (connect) with a ferromagnetic disc 34 affixed to the toilet bowl lid 20 when the toilet bowl lid 20 is in the “up” position, as shown in FIG. 3A . It is understood that the ferromagnetic disk 30 may comprise iron, steel, and/or other ferromagnetic material.
In this “initial position” of FIG. 3A , the toilet 10 is ready for use and the actuator linkage 24 is positioned to pull the drain pull chain 18 to flush the toilet 10 when the toilet bowl lid 20 is lowered to a fully lowered position of FIG. 3D . As the toilet bowl lid 20 is lowered, the actuator linkage 24 is pulled from its initial position in the direction of the front of the toilet 10 by the magnet 30 in contact with the ferromagnetic disc 34 on the toilet bowl lid 20 . When the toilet bowl lid 20 is lowered past a certain point, the force of magnetic attraction between the magnet 30 and the ferromagnetic disc 34 is overcome by the movement of the toilet bowl lid 20 and magnet 30 and the ferromagnetic disc 34 separate.
The actuator linkage 24 thereupon returns to its initial position of FIG. 3A , wherein the magnet 30 protrudes from the toilet tank front wall 12 A. This action of the actuator linkage 24 moving back to its initial position enables the drain pull chain 18 to also lower by force of gravity and further allows the flapper 16 to close by force of gravity. At that point the toilet tank 12 can fill with water again.
The actuator linkage 24 also protrudes over the top of the toilet tank 12 when the toilet bowl lid 20 is down. The toilet bowl lid 20 in FIG. 2 is shown in the down, or closed position, which is the position between flushing cycles. Shown also on the end of the toilet bowl lid 20 is the ferromagnetic disc 34 that will contact the end of the actuator linkage 24 near the toilet tank 12 wall when the toilet bowl lid 20 is in the up position.
Referring now generally to the Figures and particularly to FIG. 3A , FIG. 3A is a side view of the toilet 10 with a cutaway of inside the toilet tank 12 when it is filled with water. The toilet tank cover 36 is shown resting atop two rear cylindrical spacers 40 , which rest on the top of a rear wall 12 C of the toilet tank 12 , and the linkage guide body 28 , which also rests on the top front wall 12 A of the toilet tank 12 . The linkage guide body 28 includes two integral cylindrical spacers 42 that exist to support one of three points of contact between the toilet tank 12 cover and the top of the toilet tank 12 . The two rear spacers 40 and the linkage guide body 28 each connect to the top of the toilet back wall 12 C via a respective integral toilet tank clips 44 . It is understood that each spacer 40 includes one individual integrated toilet tank clip 44 as a base.
In FIG. 3A the toilet bowl lid 20 is raised and the ferromagnetic disc 34 affixed to the toilet bowl lid 20 is in contact with the magnet 30 that is on the end of the protruding actuator linkage 24 . The magnet 30 on the end of the actuator linkage 24 must be a permanent magnet 30 and may be a neodymium magnet 30 or other type of permanent magnet 30 .
From the front of the toilet tank 12 , the actuator linkage 24 runs from the magnet 30 , over a front bearing 46 and over a rear bearing 48 , both bearings part of the linkage guide body 28 , to its connection to the drain pull chain 18 . Thus the actuator linkage 24 is suspended between the position of the magnet 30 on one end and the drain pull chain 18 on the other end. For example, when the toilet bowl lid 20 is in the up position, as shown in FIG. 3A , the position of the magnet 30 end of the actuator linkage is determined by its contact with the ferromagnetic disc 34 on the toilet bowl lid 20 , and remains so as the toilet bowl lid 20 is lowered until such point as the magnet 30 and ferromagnetic disc 34 release one another. When the toilet bowl lid 20 is in the down, or closed position, the position of the magnet 30 end of the actuator linkage is determined, instead, by the magnet retainer 50 . The magnet retainer 50 is a flat plastic piece with horizontal stoppers 52 integral to either side of the magnet retainer 50 , to which the magnet 30 is attached. The stoppers 52 contact the spacers 42 as the magnetic end of the actuator linkage 24 moves back towards the toilet tank 12 after flushing, preventing the magnet 30 end of the actuator linkage 24 from falling down into the toilet tank 12 .
The protrusion of the actuator linkage 24 over the top of the toilet tank 12 walls enables the magnet 30 to contact the ferromagnetic disc 34 affixed to the toilet bowl lid 20 . In the configuration shown in FIG. 3A , the flapper 16 is closed and holding water in the toilet tank 12 , ready for a flush cycle. The toilet seat 38 is down and ready for use, but the toilet seat 38 may also be raised.
To operate the actuator linkage 24 in the flushing process, as shown in FIG. 3B , after use, the toilet bowl lid 20 is beginning to be lowered, which causes the actuator linkage 24 to move over the linkage guide body 28 towards the front of the toilet 10 . The actuator linkage 24 continues to extend further beyond the top front of the toilet tank 12 as the toilet bowl lid 20 is lowered. The action of the ferromagnetic disc 34 affixed to the toilet bowl lid 20 engaged with and pulling the magnet 30 end of the actuator linkage 24 towards the front of the toilet causes the actuator linkage 24 to pull on the drain pull chain 18 . As shown in FIG. 3B , the drain pull chain 18 raises the flapper 16 to allow water from the toilet tank 12 to flow into the toilet bowl 22 . The toilet begins to flush as the toilet tank 12 drains.
Referring now generally to the Figures and particularly to FIG. 3C , FIG. 3C illustrates how further lowering of the toilet bowl lid 20 past a certain point causes the magnet 30 on the end of the actuator linkage 24 to ultimately release from the ferromagnetic disc 34 on the toilet bowl lid 20 . FIG. 3C further shows how the actuator linkage 24 will move back over the linkage guide body 28 towards its initial position, such that the drain pull chain 18 will lower and the flapper 16 will close. Before the flapper closes, as shown in FIG. 3C , the toilet tank 12 water has flowed out of the toilet tank 12 and into the toilet bowl 22 , and the flushing cycle has ended.
Referring now generally to the Figures and particularly to FIG. 3D , FIG. 3D the actuator linkage 24 is shown having returned back to its initial position, with the magnet 30 end of the actuator linkage 24 protruding over the top front of the toilet tank 12 , the flapper closed and the toilet tank 12 refilled. The toilet bowl lid 20 is closed and ready for the next use.
Referring now generally to the Figures and particularly to FIG. 4A , FIG. 4A shows how the two rear spacers 24 are affixed to the top of the toilet tank 12 to support the toilet tank 12 cover, along with the linkage guide body 28 , which is affixed to the top front of the toilet tank 12 via integral toilet tank clips 26 . This configuration allows space for the actuator linkage 24 to move over the linkage guide body 28 , between the toilet tank 12 cover and the toilet tank 12 , when flushing or releasing. The toilet tank 12 cover is shown suspended above the toilet tank 12 to provide a view of the configuration of the rear spacers and the linkage guide body 28 affixed to the top of the toilet tank 12 . The linkage guide body 28 must be positioned at the center of the top front of the toilet tank 12 such that the magnet 30 end of the actuator linkage 24 will make contact with the ferromagnetic disc 34 on the end of the toilet bowl lid 20 when the lid is in the up position.
Referring now generally to the Figures and particularly to FIG. 4B , a decorative tape 60 is shown as optional trim being applied to cover the gap between the top of the toilet tank 12 and the toilet tank cover 36 when the actuator linkage 24 is installed. The actuator linkage 24 is shown protruding over the top of the toilet tank 12 and slightly in front of the toilet tank cover 36 towards the front of the toilet.
Referring now generally to the Figures and particularly to FIG. 5 , the device is shown in side view in vertical orientation as it will rest on the top of the toilet tank 12 . The linkage guide body 28 includes an integral scaffold 54 to extend support from the tank wall clip 44 to the actuator linkage 24 . The actuator linkage 24 runs from a connection to the toilet pull chain 18 over a rear bearing 48 in the linkage guide body 28 to a front bearing 46 to the top of the linkage guide body 28 between the spacers. In one embodiment the front bearing 46 may be fixed, while in another embodiment the front bearing 46 may rotate on the horizontal axis to facilitate smooth movement of the actuator linkage 24 in a back and forth orientation. The front bearing 46 and the rear bearing 48 together facilitate both support and friction to the actuator linkage 24 , enabling it to move smoothly in a forward and backward motion with respect to the front of the toilet, as needed when pulling on or releasing tension on the drain pull chain 18 . The actuator linkage 24 is shown terminating in the round permanent magnet 30 .
Referring now generally to the Figures and particularly to FIG. 6 , FIG. 6 provides a front view of the actuator linkage 24 running over the linkage guide body 28 . On either side of the front of the linkage guide body 28 which mounts on top of the toilet tank 12 are two cylindrical spacers 42 . Between the spacers 42 is shown the round magnet 30 end of the actuator linkage 24 , which is attached to a magnet retainer 50 that is integral with the actuator linkage 24 , such that the actuator linkage 24 is maintained at rest in the initial position. The magnet retainer 50 is shown with two integral stoppers 52 on either side that hit the spacers 42 when the actuator linkage 24 moves back towards the toilet tank 12 after disengaging from the ferromagnetic disc 34 on the toilet bowl lid 20 after flushing. The end of the actuator linkage 24 that runs down into the toilet tank 12 is shown terminating at its connection with the drain pull chain 18 .
Referring now generally to the Figures and particularly to FIG. 7 , a self-install kit 700 is shown in FIG. 7 and includes the linkage guide body 28 , which includes two integral spacers 42 , depicted in side view such that only one spacer 42 is visible. In side view, the spacers 42 are shown as integral with the toilet tank clips 44 and a scaffold structure 54 , also integral to the linkage guide body 28 . The linkage guide body 28 shows the integral rear bearing 48 and front bearing 46 over which the actuator linkage 24 moves. The actuator linkage 24 is shown as a flat semi-stiff plastic ribbon 56 , which is terminated on one end by the magnet retainer 50 and magnet 30 and at the other end by an eye 58 through which the drain pull chain 18 can be hooked. The two separate spacers 40 are shown as necessary accessories to clip onto the toilet tank walls 12 A- 12 D to support the toilet tank cover 36 when the actuator linkage is installed. The ferromagnetic disc 34 is included for affixing to the center end of the toilet bowl lid 20 , positioned such that when the toilet bowl lid 20 is in the up position, the disc fully contacts the magnet 30 on the end of the actuator linkage 24 . The optional decorative tape 60 is included for covering the gap between the toilet tank 12 and the toilet tank cover 36 when the actuator linkage 24 is installed.
Referring now generally to the Figures and particularly to FIGS. 8A, 8B and 8C , in typical use of a standard flushometer 800 . As shown in FIG. 8A , a prior art handle 802 is attached to a vacuum breaker 804 that is connected to a tailpiece 806 that is further connected through a hole in the wall above the flushometer 800 .
The present invention as shown in FIG. 8B wraps an actuator linkage 808 to a handle 802 and is covered by an encapsulating cover 810 with a ferrous disc 34 affixed to a toilet bowl lid 20 in the “down” position.
FIG. 8C shows an actuator linkage 808 attached to a magnet 30 that is wrapped to a handle 802 covered by an encapsulating cover 810 . In the view water flows from the tailpiece 806 down through a vacuum breaker 804 and a vacuum breaker kit 812 .
FIG. 9A is top view of a third alternate embodiment 900 of the invented linkage assembly that includes a thin plastic strip 902 within a third arm 904 . An arm aperture 906 is adapted to accept coupling with the drain pull chain 18 . An alternate coupling end 908 is a ferromagnetic material that is attracted to a magnetic toilet bowl lid 910 whereby the third arm 904 is detachably attachable to the magnetic toilet bowl lid 910 . An attachment feature 911 durably couples the third arm 904 to the alternate coupling end 908 .
FIG. 9B is top view of a fourth alternate embodiment 912 of the invented linkage assembly that includes a cord 914 within a fourth arm 916 . A first cord loop assembly 918 A of the cord 914 is adapted to enable coupling of the cord 916 with the drain pull chain 18 . The second alternate coupling end 920 is a ferromagnetic material that is attracted to a magnetic portion 922 of a fourth alternate toilet bowl lid 924 whereby the fourth arm 916 is detachably attachable to the fourth alternate toilet bowl lid 924 . A second cord loop assembly 918 B of the cord 914 is adapted to enable coupling of the cord 916 with the second alternate coupling end 920 .
FIG. 9C is top view of a fifth alternate embodiment 926 of the invented linkage assembly that includes a cable 928 within a fifth arm 930 . A cable loop assembly 932 of the cable 928 is adapted to enable coupling of the fifth arm 930 with the drain pull chain 18 . The second alternate coupling end 920 is attracted to a magnetic disc 933 A that is attached to a fifth alternate toilet bowl lid 933 B whereby the fifth arm 916 is detachably attachable to the fifth alternate toilet bowl lid 933 B.
FIG. 9D is top view of a fourth alternate embodiment 934 of the invented linkage assembly that includes a wire 936 within a sixth arm 938 . A wire loop assembly 940 of the wire 936 is adapted to enable coupling of the sixth arm 938 with the drain pull chain 18 . A second weld 942 couples the sixth arm 938 with the magnet 30 .
Finally, the language used in the specification has been principally selected for readability and instructional purposes, and it may not have been selected to delineate or circumscribe the inventive subject matter. It is therefore intended that the scope of the invention be limited not by this detailed description, but rather by any claims that issue on an application based herein. Accordingly, the disclosure of the embodiments of the invention is intended to be illustrative, but not limiting, of the scope of the invention, which is set forth in the following claims. | A toilet bowl lid actuated linkage toilet flushing system wherein a conventional toilet-flushing flapper is actuated by a drain pull chain controlled relative to the positioning of the toilet bowl lid to the toilet. The toilet bowl lid must be moved from an upward position to a downward position to flush the toilet, which a magnetic plastic ribbon actuator mechanism is provided for completion of the toilet flush even when the toilet bowl lid remains in the downward position. Movement of the lid actuates a magnetic flush pull of a plastic ribbon that is linked to a drain pull chain connected to the flapper. An alternate version of the toilet bowl lid actuated linkage toilet flushing system is compatible with flushometer toilets and enables an opening and closing of a valve controlling outflow of a pressurized water source. | 4 |
CROSS REFERENCE TO RELATED U.S. PATENT APPLICATION
[0001] This patent application relates to U.S. provisional patent application Ser. No. 61/353,948 filed on 11 Jun. 2010 entitled FOLDING ENDOSCOPE AND METHOD OF USING THE SAME, filed in English, which is incorporated herein in its entirety by reference.
FIELD OF THE INVENTION
[0002] The present invention relates generally to the field of endoscopes, and more particularly the present invention relates to folding endoscopes with incorporated optical sensors and light source.
BACKGROUND OF THE INVENTION
[0003] Generally speaking, endoscopes are thin tubular cameras that are typically utilized in the diagnosis of a disease. These cameras are usually inserted into the body cavity either through a natural opening like the mouth or the anus or through a tiny incision made into the skin. The endoscopes are extensively used intra-operatively to assist the surgeon in visualizing the anatomy of interest to perform the procedure and to avoid damage to critical surrounding organs. Most of the endoscopes available in the market to date can be classified into either a rigid or a flexible endoscope. Commonly found endoscopes are available with two-dimensional cameras and have limited image resolution and depth perception. These endoscopes are disorienting to the surgeon after a prolonged use and lack the natural spectrum of direct human visualization.
[0004] Recently some manufacturers have started producing three-dimensional (stereoscopic) endoscopes. The optical version of these endoscopes use two tubular lenses inside a long shaft and two standard cameras mounted outside of the body. The next generation of stereo endoscopes employs custom designed semiconductor circuitry mounted at the tip of the endoscope (inside the body) that is capable of producing stereo images. In these endoscopes, either two close proximity mounted chips or a special chip with a large array of micro lenses manufactured onto the chip is utilized to create stereo images. In addition, such endoscopes also include LED or fiber optic light sources for illumination. FIG. 1 shows a conventional stereo endoscope.
[0005] U.S. Pat. No. 4,862,873 issued to Yajima et al. discloses a stereo endoscope that utilizes two thin optical guides mounted in a tubular shaft and two CCD image sensors mounted outside the body to create three-dimensional images of the organ.
[0006] U.S. Patent application US2002/0007110, to Irion discloses a stereo endoscope that utilizes two lateral mounted cameras with a flexible endoscope head to create three-dimensional images of the organ.
[0007] The field of surgical intervention has evolved from open invasive approach to the paradigm of minimally invasive surgery due to its benefits to the patients and the healthcare system. From the surgeon's perspective, the transition has resulted in a procedure with limited and un-natural field of view and surgical skills that have a steep learning curve. The existing three-dimensional endoscopes have resulted in incremental enhancement to the visualization, but have failed to match the natural spectrum of direct human visualization. The 3D depth perception of these endoscopes is also constrained by the limited physical separation between the two cameras. Additionally, it is projected that the surgical paradigm will shift from the three or four incision laparoscopic approach to a single incision (single port access (SPA)) surgery.
[0008] Thus, there is a need and good market potential for improved endoscopes that can provide a better visualization of the surgical site.
SUMMARY OF THE INVENTION
[0009] The present invention provides a foldable endoscope, comprising:
a) a housing having a first and second end and a longitudinal axis, said housing including at least one channel extending between said first and second end, and associated ports at said first and second end for inserting surgical instruments through said housing into a surgical site; b) at least two elongate arms each having a first and second end and each being pivotally connected at said first end thereof to said first end of said housing; c) at least one camera each camera being mounted on one of said at least two elongate arms; and d) a linkage mechanism connected to said at least two elongate arms, said linkage mechanism, upon activation, being configured to pivotally deploy said at least two elongate arms from a closed position in which said at least two elongate arms are aligned along said longitudinal axis to an open position in which said second ends of said at least two elongate arms radially spaced from said longitudinal axis.
[0014] The disclosed endoscope taps nicely into the emerging market due to its improved visualization capabilities and integrated support to pass surgical tools through the other ports making it a versatile surgical tool.
[0015] A further understanding of the functional and advantageous aspects of the invention can be realized by reference to the following detailed description and drawings.
BRIEF DESCRIPTION OF THE DRAWINGS
[0016] Preferred embodiments of the invention will now be described, by way of example only, with reference to the drawings, in which:
[0017] FIG. 1 shows a conventional prior art stereo endoscope;
[0018] FIG. 2 shows an embodiment of the foldable endoscope in a fully closed or retracted state;
[0019] FIG. 3 shows the foldable endoscope in a partially open state;
[0020] FIG. 4 shows the foldable endoscope in the fully open state;
[0021] FIG. 5 shows another embodiment of the foldable endoscope that includes a mirror arrangement; and
[0022] FIG. 6 shows the block diagram of the image processing of the images acquired by the cameras mounted on the foldable endoscope.
DETAILED DESCRIPTION OF THE INVENTION
[0023] Without limitation, the majority of the systems described herein are directed to folding endoscopes with incorporated optical sensors and light source. As required, embodiments of folding endoscopes are disclosed herein. However, the disclosed embodiments are merely exemplary, and it should be understood that the disclosure may be embodied in many various and alternative forms. In certain instances, well-known or conventional details are not described in order to provide a concise discussion of embodiments of the present disclosure.
[0024] The Figures are not to scale and some features may be exaggerated or minimized to show details of particular elements while related elements may have been eliminated to prevent obscuring novel aspects. Therefore, specific structural and functional details disclosed herein are not to be interpreted as limiting but merely as a basis for the claims and as a representative basis for teaching one skilled in the art to variously employ the present invention. For purposes of teaching and not limitation, the illustrated embodiments are directed to folding endoscopes with incorporated optical sensors and light source.
[0025] As used herein, the term “about” and “approximately”, when used in conjunction with ranges of dimensions, temperatures or other physical properties or characteristics is meant to cover slight variations that may exist in the upper and lower limits of the ranges of dimensions so as to not exclude embodiments where on average most of the dimensions are satisfied but where statistically dimensions may exist outside this region. For example, in embodiments of the present invention dimensions of components of a folding endoscope are given but it will be understood that these are not meant to be limiting.
[0026] Referring to FIG. 2 , herein is disclosed a foldable endoscope 10 that utilizes multiple cameras 30 to create three-dimensional images of the target. FIG. 2 shows the endoscope 10 in collapsed form, and FIG. 3 shows the endoscope 10 in half open form. In the collapsed form, the endoscope 10 assumes a very compact formation and can be easily introduced into the patient's body through a standard trocar. In the preferred embodiment, the endoscope 10 contains a slender body 12 that forms a generally cylindrical housing, a center spoke 40 , three connecting linkages 16 , and three folding arms 14 with cameras 30 and light sources 34 integrated into each of the arms. Each folding arm 14 in the preferred embodiment includes two hinge joints; a first hinge joint 18 with the endoscope body 12 and a second hinge joint 20 with the connecting linkage 16 . In the preferred embodiment, each connecting linkage 16 also has a hinge joint 22 with the center spoke 40 . The center spoke 40 includes a telescopingly movable hollow drive shaft 44 and may optionally include a plurality of integrated light sources 36 (light emitting diodes (LEDs), fiber optic light sources, etc).
[0027] The optical sensors or cameras are preferably charge coupled device (CCD) images sensors, but other types of image sensors may be used. For example, complementary metal-oxide-semiconductor (CMOS) image sensors may be preferred in some embodiments due to their low cost.
[0028] The endoscope 10 also includes one or more instrument ports 50 through which various surgical instruments can be introduced to perform the procedure. Non-limiting examples of such instruments include scalpels, incision devices, tweezers, scissors, etc. In the preferred embodiment, the diameter of slender body 12 is preferably about 10 mm and the diameter of each instrument port 50 is preferably about 2.5 mm. The disclosed invention is particularly suitable for the case of a single port access surgery where both the visualization and the surgical procedure is performed through one incision as opposed to the three or four of a typical laparoscopic procedure. Endoscope 10 may optionally include a fiber optic illumination port 42 mounted on the center spoke 40 to enhance visibility of the surgical site. In the preferred embodiment, the diameter of fiber optic illumination port 42 is preferably about 1.75 mm. The fiber optic illumination port 42 is a hollow shaft that runs concentrically through the center spoke 40 and the hollow drive shaft 44 .
[0029] FIG. 3 shows the preferred embodiment of the disclosed invention in the half open form. The hollow drive shaft 44 is designed to translate in and out through the center port 46 of the endoscope body 12 .
[0030] Here “in” motion is referred to as the motion of the center spoke 40 towards the endoscope body 12 and “out” motion is referred to as the motion of the center spoke 40 away from the endoscope body 12 . Each hinge joint ( 18 , 20 , and 22 ) is a low friction joint that allows two mating components to freely rotate with respect to each other about the hinge axis. A hollow drive shaft 44 is connected on one end to the center spoke 40 and is connected at the other end to the endoscope body 12 to create the linear “in” and “out” motion of the center spoke 40 with respect to the endoscope body 12 . In a preferred embodiment, this motion is provided by an actuator (not shown here, preferably located outside the body). Those skilled in the art will appreciate that any actuator may be used; some non-limiting examples include solenoids, motors with rack and pinion gears, hydraulic actuators, pneumatic actuators, cable actuators, worm gears, and wheels with tracks.
[0031] A fiber optic illumination source may be passed through the hollow shaft 44 to enhance visibility of the surgical site. Optionally, one of more of the illumination sources 36 on the center spoke 40 may be replaced with one or more cameras 30 that can facilitate easy insertion of the endoscope into patient's body cavity.
[0032] One preferred method of utilizing the disclosed invention in a single port access surgery can be as following. Initially with the endoscope 10 outside the body, the hollow shaft 44 is actuated such that the center spoke 40 is at its farthest “out” position and as a result the endoscope is fully collapsed (as shown in FIG. 2 ) and can be easily introduced into the patient's body through a standard trocar. Once inside the body, the hollow shaft 44 is actuated to cause “in” motion of the center spoke 40 towards the endoscope body 12 . The umbrella structure of the mechanism causes it to unfold and gradually take up its open shape as the center spoke 40 is actuated towards the fully “in” position (as shown in FIG. 4 ). The tile angle for cameras 30 can be simultaneously controlled by “in” and “out” motions of the center spoke 40 in the direction of arrow 64 . The actuator is used to control how much the umbrella structure opens up, and this depends on the user of endoscope and how much overlap is required between the cameras 30 .
[0033] Once fully deployed, endoscope 10 can be firmly held in place (outside the body) by an assistant, a passive support arm, or a robotic system. The endoscope 10 can also be rolled through the use of an optional second actuator about axis 60 in the direction of arrows 62 until desired visualization of the anatomy is achieved.
[0034] FIG. 5 shows another embodiment of the foldable endoscope that includes a mirror arrangement 14 that assists in the insertion of the endoscope into the body cavity. In its collapsed form (as shown), the mirror 14 is oriented such that it reflects light rays that are parallel to the longitudinal axis of endoscope body 12 onto the image sensor 30 thereby creating an image that is orthogonal to the endoscope longitudinal axis. This image is the same image as obtained using the conventional endoscopes as they are being inserted into the body cavity. Once inside the body and after the mechanism has been unfolded, mirror 14 has no function and the endoscope creates 3D images as explained before. This mirror arrangement obviates the need of another 2D image sensor on the center spoke 40 that can assist in endoscope insertion through the trocar. FIG. 6 shows the block diagram of the disclosed invention. The video outputs 122 from various cameras 120 go to an image processor 100 that performs various image processing algorithms for example stereo generation, image stitching etc. on these images. The processed images are provided to the surgeon's in either a two-dimensional or a three-dimensional format through the use of a display device 104 or 106 (monitor, projector, 3D monitor, 3D goggles, etc). The image processor 100 may also control camera tilt and roll system 110 in order to generate a view from a different orientation and perspective. The roll and tilt system is preferably composed of two actuators that cause the linear motion of center spoke 40 along arrows 64 and roll of body 12 about axis 60 (as shown by arrow 62 ). Depending upon the anatomy, the image processor may also control the illumination system 102 to adjust for optimal image quality. The illumination system 102 may automatically adjust camera parameters based on feedback from image signals received from the cameras. The illumination system 102 may include any manual input device such as a physical button, knob, or slider, or it may be a graphical user interface element displayed on a monitor. Further, when producing three-dimensional images, the image processor 100 may further rotate, translate, and scale the produced images either by decisions made from software control systems or from manual control from the user, or both.
[0035] The surgeon may interact with the image processor 100 through a user interface that includes an input device (computer mouse, keyboard, microphone, buttons, joystick, touch screen etc) to select various features and options. The surgeon can optionally switch between two-dimensional and three-dimensional views or can visualize them side by side on displays 104 and 106 . The surgeon may use the user interface to change views, to change brightness or contrast parameters, to rotate, scale, or translate 3D views, or to make other parameter changes that influences the display shown on monitors.
[0036] Those skilled in the art will appreciate that many computer vision algorithms may be performed by the image processor 100 including but not limited to: image stitching, 3D reconstruction from multiple views, shape from shading, depth from focus, feature detection, feature matching for pose estimation, optical flow algorithms, background subtraction, automatic object classification, and image segmentation. These techniques may be used to assist the user of the endoscope in performing operations with the device. Further, those skilled in the art that the image processor 100 may be a dedicated computer processor such as a CPU, DSP microchip, or microprocessor, or the image processor 100 may be integrated in a computer system such as a software program running on a desktop computer, laptop, mobile device, or mobile phone. The disclosed invention utilizes an umbrella type mechanism to mount and control one or more cameras (preferable two or more) that is not found in conventional two-dimensional and three-dimensional endoscopes. The increased physical separation between different cameras of the disclosed invention will lead to an improved 3D depth perception than that of the close mounted dual cameras in the existing systems. The increased number of cameras (preferably three or more) present in the disclosed invention will lead to enhanced visualization of the anatomy through image stitching. The mechanism disclosed herein is fairly simple and low cost to produce. The number of folding arms can be limited to two if reduced cost or functionality is desired.
[0037] As used herein, the terms “comprises”, “comprising”, “includes” and “including” are to be construed as being inclusive and open ended, and not exclusive. Specifically, when used in this specification including claims, the terms “comprises”, “comprising”, “includes” and “including” and variations thereof mean the specified features, steps or components are included. These terms are not to be interpreted to exclude the presence of other features, steps or components.
[0038] The foregoing description of the preferred embodiments of the invention has been presented to illustrate the principles of the invention and not to limit the invention to the particular embodiment illustrated. It is intended that the scope of the invention be defined by all of the embodiments encompassed within the following claims and their equivalents. | Disclosed is a folding endoscope with incorporated optical sensors and light sources. The foldable endoscope includes a housing having first and second ends and a longitudinal axis and at least one channel extending between the first and second ends and associated ports at the first and second ends for inserting surgical instruments through the housing into a surgical site. The endoscope includes three elongate arms having first and second ends and being pivotally connected at the first ends thereof to the first end of the housing. A camera and light source are mounted on each of the elongate arms such that when the elongate arms are deployed the cameras have a field of view in a generally forward direction away from the housing. A linkage mechanism is connected to the elongate arms, and an actuator is connected to the linkage mechanism. The linkage mechanism, upon activation by the actuator, is configured to pivotally deploy the three elongate arms from a closed position in which the elongate arms are aligned along the longitudinal axis to an open position with the second ends of the elongate arms radially spaced from the longitudinal axis. | 0 |
CROSS-REFERENCE TO RELATED APPLICATIONS
This application claims the benefit of U.S. Provisional application 60/579,883 filed Jun. 15, 2004, and hereby incorporated by reference.
STATEMENT REGARDING FEDERALLY SPONSORED RESEARCH OR DEVELOPMENT
BACKGROUND OF THE INVENTION
The present invention relates to automatic dishwashing machines (dishwashers) and in particular to a dishwasher vent for use in a low noise dishwasher.
Dishwashers, such as those found in many homes, provide a chamber holding one or more racks into which eating utensils and cookware may be placed for cleaning. The chamber may be closed by a door opening at the front of the chamber to allow loading and unloading of the chamber.
The door is closed during a washing cycle to prevent the escape of water sprayed within the volume of the chamber to wash items placed in the rack. Upon completion of the washing cycle, a drying cycle is initiated during which water is drained from the chamber and moist air is discharged through a vent. Cool air pulled into the chamber through a lower vent rapidly dries the heated dishes.
Dishwashers can be loud, particularly during the washing cycle, with noise coming from the agitated water, movement of the dishes, and the dishwasher mechanism of pump and motor. Some of this noise can be reduced by properly shrouding the washing chamber with acoustically absorbent material, nevertheless, even with a properly shrouded chamber, a substantial amount of noise can escape through the vent by diffraction.
One method of reducing vent-transmitted noise is by offsetting the inlet and outlet of the vent to provide a baffling that prevents direct passage of sound through the vent opening. This approach can also prevent water from passing through the vent.
A second method of reducing vent-transmitted noise is to close the vent with a valve plate or similar mechanism during the washing cycle and open the vent only during the drying cycle. A vent suitable for this purpose is described in U.S. Pat. No. 6,293,289 filed Nov. 8, 1999, assigned to the assignee of the present invention, and hereby incorporated by reference. This patent describes, in one embodiment, a wax motor operating a hinged valve plate that opens and closes to control air and sound flow through the vent. The hinged plate may also be independently opened by excess pressure in the washing machine so as to accommodate “surge pressures” resulting, for example, from pressure build up caused by an opening and closing of the dishwasher in mid-cycle where introduced cold air is rapidly heated by dishes and hot water when the door is resealed.
Superior drying requires that the vent area be made as large as possible when the vent is open and that the valve plate provide minimal obstruction to the flowing air. This may be done by placing the hinge axis of the valve plate generally parallel to the front and rear surfaces so that the valve plate opens to align with the natural flow lines of air.
The actuator for a valve plate in a vent may be positioned outside of the vent housing (defining the vent passage) to improve airflow and to protect the actuator from water. This may be accomplished by extending the shaft about which the vent plate rotates out of the vent housing through a journal hole in one wall of the vent to be engaged by an actuator. The journal hole is kept small to prevent the escape of water from the vent and may include a seal.
Mechanically, passing the shaft through a wall of the vent housing requires either that the vent plate be detachable from the shaft, so that the shaft may be inserted through a journal hole into the housing without obstruction, or that the housing be separable into two halves to allow an integral vent plate/shaft assembly to be positioned in the vent body and the housing closed over that. Both of these approaches increase the complexity of manufacturing the vent: the former requiring assembly of the shaft and vent plate from inside of the vent, and the latter requiring assembly of the vent housing from several pieces.
BRIEF SUMMARY OF THE INVENTION
The present invention employs a cam drive mechanism moving a valve plate within a dishwasher vent without the need for a direct connection between an actuator and the shaft about which the valve plate rotates. This approach allows the valve plate shaft to be retained wholly within the vent housing eliminating leaks along a rotating shaft passing through the housing or excess shaft friction, and allowing the vent housing to be molded or preassembled as one piece with the valve plate is snapped into place subsequent to the molding.
The drive mechanism allows the axis of the valve plate and the drive actuator (preferably a wax motor) to be parallel and closely adjacent to the valve plate pivot axis, providing an extremely compact mechanism that may fit easily between the front and rear panel of a dishwasher door. This advantage also applies to an embodiment in which the valve plate is supported by externally inserted pins or the like.
In one embodiment, the cam mechanism may open and close the valve plate without the need for a biasing spring element or reliance on gravity, and may accommodate over travel common in wax motors while still providing a large amount of mechanical amplification to fully open and close the valve plate with small amounts of actuator travel.
In one embodiment, the operator may extend along an axis parallel to, but displaced from, a pivot axis of the valve plate to provide an extremely compact assembly.
In one embodiment, a spring biases the valve plate to allow the valve plate to open independently of the wax motor to relieve surge pressures.
In one embodiment, an elastomeric seal is held in cantilevered fashion at the valve seat to provide a compliant seal blocking sound transmission.
These particular objects and advantages may apply to only some embodiments falling within the claims and thus do not define the scope of the invention.
BRIEF DESCRIPTION OF THE DRAWINGS
FIG. 1 is a simplified view of a dishwasher in perspective showing location of a door vent for venting moist air;
FIG. 2 is an exploded perspective view of the door vent of FIG. 1 as viewed from the inside of the dishwasher and as may be positioned between the front and rear door surfaces;
FIG. 3 is a cross-sectional view of the inlet port of the vent of FIG. 2 taken along lines 3 - 3 showing a snap-in engagement of an integrated vent plate and shaft at the inlet port;
FIG. 4 is a cross-sectional view taken along lines 4 - 4 of FIG. 3 showing the vent plate in a closed configuration for blocking sound and the flow of air;
FIG. 5 is a perspective view of the engagement between a wax motor actuator and a cam surface on the vent plate of FIG. 4 as viewed from inside the vent housing;
FIGS. 6 a through 6 c are rear elevational views of the cam surface with the vent plate in three states of closed, transition, and open;
FIG. 7 is a figure similar to that of FIG. 4 showing an alternative embodiment of the door vent in which the valve plate may move independently in response to surge pressures; and
FIG. 8 is a figure similar to FIG. 7 showing an alternative embodiment in which the valve plate has a default open position if the wax motor is removed.
DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENT
Referring now to FIG. 1 , a dishwasher 10 may include a housing 12 holding a washing chamber and a front door 14 that may be opened to obtain access to the washing chamber for loading and unloading of dishes. A door vent 16 provides an outlet port 18 in the front surface 20 of the door 14 to allow for the escape of moist air 22 .
Referring now to FIG. 2 , a vent housing 24 provides an air passage between the outlet port 18 on the front surface 20 and an inlet port 26 opening at the rear surface 28 of the door 14 facing the washing chamber. The outlet port 18 is positioned higher on the door than the inlet port 26 , both to provide a serpentine path for muting sound passing through the vent housing 24 and to cause water splashed into and condensation forming within the vent housing to drain downward out of inlet port 26 back into the wash chamber. Preferably, the vent housing 24 is manufactured as a single injection molded part avoiding a need for subsequent assembly of multiple components using screws or welds and eliminating the need to test for leakage of the seams or to provide expensive gasketing at the seams.
The air passage of the vent housing 24 is substantially continuous to prevent leakage of water into the door 14 , with the exception of a bore 30 opening between inlet port 26 and outlet port 18 , generally perpendicular to the airflow. The bore 30 may be created during the molding of the vent housing 24 using an injection mold with a removable core pin as is understood in the art.
The bore 30 allows an operator 32 of a wax motor 34 (the wax motor 34 positioned outside the vent housing 24 ) to enter the air passage. The operator 32 of the wax motor 34 has an o-ring seal 36 allowing movement of the operator within the bore 30 without the leakage of liquid there through as will be described below.
Referring still to FIG. 2 , the inlet port 26 is covered at the rear surface 28 of the door 14 by a removable vent cap 40 that attaches to the vent housing 24 by a twist lock formed from a set of interengaging tabs 41 molded into both the vent cap 40 and the inlet port 26 . The vent cap 40 provides an aperture 42 aligning with the opening of the inlet port 26 and the aperture 42 is covered by a grating 44 so as to deflect water and food particles away from the passageway of the vent housing 24 .
The vent cap 40 also provides a rear facing valve seat ring 46 extending into the inlet port 26 . This valve seat ring 46 cooperates with a valve plate 48 removably attached within the inlet port 26 to hinge about a hinge axis 51 . The hinge axis 51 is located beneath the valve plate 48 in a horizontal plane and is parallel to the front surface 20 and rear surface 28 .
When the valve plate 48 is in a closed position as shown in FIG. 4 , a rubber disk 50 forming the inner surface of the valve plate 48 abuts the edge of the valve seat ring 46 blocking the flow of moist air 22 into the vent passageway and providing a barrier against sound 52 . The rubber disk 50 is supported from front and its side removed from the vent cap 40 by a support disk 54 of slightly smaller diameter than the rubber disk 50 so that the peripheral edge of the rubber disk 50 extends in cantilevered fashion from the peripheral edge of the support disk 54 so as to flex to accommodate slight irregularities in the valve seat ring 46 of the vent cap 40 .
Referring now to FIG. 3 , the support disk 54 of the valve plate 48 includes four hooked tabs 56 extending through corresponding holes in the rubber disk 50 . The rubber disk 50 may be stretched to fit over the hooked tabs and thereby retained against the support disk 54 by the hooks on the hooked tabs 56 . Sizes of the openings 58 in the rubber disk 50 are relatively small being typically substantially less than 1/10th the total area of the rubber disk 50 . Accordingly, as shown in FIG. 4 , the rubber disk 50 covers the majority and the center of the support disk 54 providing improved sound absorption when the valve plate 48 is closed in comparison to systems which use an annular rubber gasket. Using a substantially continuous rubber disk 50 also provides a cost savings by eliminating the need for a thicker support disk 54 for sound absorption and by making use of the center portions of the rubber disk 50 that might otherwise be removed and discarded in the fabrication of a washer shape.
Referring now to FIGS. 2 and 3 , the support disk 54 has downwardly extending legs 60 supporting horizontal and opposed outwardly extending pivot pins 62 defining the hinge axis 51 described above. The support disk 54 , the leg 60 , and the pins 62 may be constructed of a material, such as injection moldable thermoplastic, providing sufficient flexibility so that the legs 60 may be compressed inward in order for the pins 62 to snap into corresponding pivot sockets 64 molded in the interior of the housing 24 adjacent to the inlet port 26 . The sockets 64 are blind, that is, they do not lead from the inside of the vent housing 24 to the outside of the vent housing 24 , and therefore the sockets 64 provide no passage for water or moisture splashing into the vent housing 24 to leak into the door 14 . Eliminating the need for the shaft supporting the valve plate 48 to pass wholly through the vent housing 24 simplifies single piece injection molding of the vent housing 24 , improves the integrity of the vent housing 24 , and reduces resistance of valve plate 48 to movement about the hinge axis 51 by allowing a small contact area between the pins 62 and sockets 64 .
The present invention also contemplates an alternate embodiment in which one or more metal pins (not shown) may be pressed into through holes aligned with but replacing the sockets 64 and serving as an axle for the valve plate 48 . As before, the advantages of being able to produce a single piece molding of the vent housing 24 , of limiting the path of water leakage, and of avoiding the excess resistance of a rotating drive shaft may be obtained.
Referring now to FIGS. 4 and 5 , actuation of the valve plate 48 is accomplished without external access to a supporting shaft of the valve plate 48 by a cam drive mechanism. As mentioned above, the operator 32 of the wax motor 34 may extend into the vent housing 24 through bore 30 . The end of the operator 32 has a ball tip 70 that engages a cam 72 extending from the side of the support disk 54 removed from the vent cap 40 . The cam 72 provides actuation surfaces that form a Z-shaped channel capturing the ball tip 70 and thus allowing opening and closing of the valve plate 48 with extension and retraction of the operator 32 by the wax motor 34 . The ball tip 70 may include a hook (not shown) to provide improved engagement with the cam 72 as will be understood to those of ordinary skill in the art.
Generally, the extension axis 74 of the operator 32 is parallel to the hinge axis 51 with the ball tip 70 of the operator 32 positioned closely to the hinge axis 51 . This produces an extremely compact mechanism and one that is desirably sensitive to small motions of the operator 32 . Yet the range of travel of the operator 32 of a wax motor 34 can vary over time, so capture of the ball tip 70 by the cam 72 requires an accommodation of assembly tolerance and over travel of the operator 32 .
Referring now to FIG. 6 , this accommodation is provided by creating over travel and under travel portions of the cam 72 . When the ball tip 70 is in its further extent from the wax motor (to the left in FIG. 6 a ), it is in the over travel position 79 and contacts cam surface 76 which extend generally horizontally so that further travel of the ball tip 70 does not provide further torsion or twisting of the valve plate 48 about the hinge axis 51 . In this over travel position 79 , the valve plate 48 is closed against the valve seat ring 46 as shown in FIG. 4 . Surface 77 may lie on a radius about axis 51 to allow free rotation of valve plate 48 in a closing direction without interference between the ball tip 70 and surface 77 , reflecting the constant radial distance between ball tip 70 and axis 51 . Ultimately, closing of the valve plate 48 is limited by the engagement of the valve plate 48 and the valve seat ring 46 .
When the ball tip 70 is retracted somewhat, it moves to an actuation position 82 as shown in FIG. 6 b , the ball tip 70 now held captive between upper surface 84 and lower cam surface 78 diagonal to the hinge axis 51 and causing an opening or closing of the valve plate 48 with retraction or extension of the ball tip 70 . This actuation position 82 may be relatively short and may be fit easily within the assured operating range of the wax motor 34 during its lifetime or caused by unit-to-unit variation.
As shown in FIG. 6 c , when the ball tip 70 is closest to the wax motor 34 , for example, prior to closure of the valve plate 48 or after opening of the valve plate 48 , it is held captive between surfaces 90 and 92 on its top and bottom sides in an under travel position 86 . The surfaces 90 and 92 are essentially horizontal so that the ball tip 70 may be threaded into engagement with the cam 72 when the wax motor 34 is installed on the housing 24 . Thus, over travel and under travel may be accommodated while maintaining a close coupling between the ball tip 70 and the cam 72 .
Referring now to FIG. 7 , in a second embodiment, the cam 72 may be modified to remove the surfaces 76 , 84 , and 90 shown in FIGS. 6 a , 6 b , and 6 c . As described above, these surfaces are used to allow extension of the ball tip 70 to close the valve plate 48 . Surfaces 78 and 92 which allow the ball tip 70 to open the valve plate 48 , remain in place. As a result, the entire surface of the cam 72 above surfaces 78 and 92 is lies on a constant radius about axis 51 to allow free rotation of valve plate 48 in a closing direction without interference between the ball tip 70 and surface 77
Closing of the valve plate 48 is performed in this embodiment by a helical compression spring 94 placed between the rear surface of the support disk 54 and a front surface of the rear wall of the housing 24 . Normally this spring 94 causes the valve plate 48 to close against the valve seat ring 46 absent contact between the ball tip 70 and the cam surfaces 78 or 92 . Moist air 22 of a predetermined pressure (for example, one half inch of water) as selected by varying the force of the spring 94 and the area of the valve plate 48 , will allow the valve plate 48 to swing open independent of the position of the ball tip 70 to relieve surge pressures as required.
In the absence of surge pressure, the valve plate 48 may be opened by the ball tip 70 interacting with cam surfaces 78 and 92 as described above. Other methods of biasing the valve plate 48 closed including gravity or other types of springs may also be employed as will be understood to those of ordinary skill in the art.
Referring now to FIG. 8 , an alternative embodiment of the door vent 16 provides both the surge pressure release, described above, and a default open position for the valve plate 48 . This default to an open position allows air to pass through the door vent 16 should the wax motor 34 (described above) be removed or the ball tip 70 and/or its connecting shaft be broken or damaged in such a way as to disengage from the cam 72 . In this way, the risk of suffocation to a child entrapped in a dishwasher that has been abandoned or partially disassembled is reduced.
In contrast to the embodiment shown in FIG. 7 in which compression spring 94 is used to close the valve plate 48 , in the embodiment of FIG. 8 , a torsion spring 100 is placed about pivot axis 51 so as to provide a clockwise bias 109 to the cam 72 about the hinge axis 51 . The bias provided by torsion spring 100 opens the valve plate 48 absent countervailing force by the ball tip 70 on the cam surface 76 (also shown in FIGS. 6 a - c ).
In this embodiment, the support disk 54 of the valve plate 48 is not rigidly attached to the cam 72 , but may pivot with respect to the cam 72 about a second hinge axis 102 on the cam 72 . A helical compression spring 104 fits between the rear surface of the support disk 54 and the front surface of an extension 106 to the cam 72 , so that the support disk 54 is biased forward toward the valve seat ring 46 in a counter-clockwise direction 108 about hinge axis 102 .
Movement of the support disk 54 in the counter-clockwise direction 108 is limited by a stop 110 extending rearward from the support disk 54 to oppose a rear surface of the upward extension 106 , allowing only limited relative travel between the support disk 54 and the cam 72 in a counter-clockwise direction 108 .
It will be understood from this description, that removal of the ball tip 70 will cause the cam 72 to move in a clockwise direction under the bias of the torsion spring 100 . This will cause valve plate 48 to open after its forward travel in a counter-clockwise direction 108 under the urging of spring 104 and is stopped by stop 110 .
Conversely in normal operation, when the ball tip 70 is fully extended from the wax motor 34 , the cam 72 is rotated in a counter-clockwise direction pressing the valve plate 48 and the rubber disk 50 against the valve seat ring 46 to close the vent. The helical compression spring 104 allows some over-travel of the cam 72 with no adverse effect.
In this position, a surge pressure of moist air 22 can nevertheless push against the valve plate 48 causing clockwise rotation against the spring 104 as described previously to open the valve plate 48 without movement of the cam 72 .
It is specifically intended that the present invention not be limited to the embodiments and illustrations contained herein, but include modified forms of those embodiments including portions of the embodiments and combinations of elements of different embodiments as come within the scope of the following claims. | A mechanized vent for a dishwasher employs a vent plate moving about a hinge axis as driven by a cam mechanism at a surface of the vent plate removed from the hinge axis. | 8 |
FIELD OF THE INVENTION
[0001] This invention relates to electrical circuits for system safety controls, and in particular to an emergency machine off for shutdown of equipment.
BACKGROUND
[0002] In many environments such as industrial environments, multiple pieces of equipment are utilized which may share energy or power hazards. Under these circumstances it is important for safety purposes to incorporate EMO (Emergency Off) initiated from any piece of equipment which will shut off all the equipment if a hazardous condition occurs. An example of a patented EMO feature is illustrated in US Patent Publication US 2009/0066502, published Mar. 12, 2009.
[0003] A possible straightforward design of EMO linkage utilizes N EMO switches each having N contacts, where N is the number of pieces of equipment in a test cell. An example of a test cell in a manufacturing environment might include: a puncher; a presser; a packager; and a handler. The various pieces of equipment in a test cell may cover a large physical area, but EMO connectivity must be maintained between all the pieces of equipment. FIG. 1 illustrates an example of the aforementioned EMO linkage design. In this example, four pieces of equipment 100 , 105 , 110 , and 115 share hazard conditions. Each piece of equipment includes a 4-contact EMO switch 120 . Four power loops 125 , 130 , 135 , and 140 are connected through each EMO switch, and a local EMO control circuit 145 is included in each power loop. If the power loop is closed, the local shut-down features are not activated. However, when any one of the EMO switches 120 are depressed, contacts 150 are broken for each power loop, thereby opening all four power loops. In this case, local EMO control circuits 145 are activated, shutting down all four pieces of equipment.
[0004] A problem with this aforementioned straightforward design is the difficulty in changing the equipment configuration, e.g., adding a new piece of equipment. Each time new equipment is added, an extra link in the chain (i.e. the power loops) is added, and one more contact must be added to the EMO switches for each piece of equipment in the cell. This makes field retrofit difficult, and may require design modification.
SUMMARY OF THE INVENTION
[0005] Disclosed herein is a simplified EMO linkage circuit that enables add-on equipment without retrofit, and eliminates the need for multi-contact EMO switches.
BRIEF DESCRIPTION OF THE DRAWINGS
[0006] FIG. 1 illustrates a traditional EMO linkage design.
[0007] FIG. 2 illustrates an embodiment of the inventive EMO linkage design.
DETAILED DESCRIPTION
[0008] FIG. 2 illustrates an embodiment of an inventive simplified EMO linkage circuit design. Each piece of equipment is associated with an identical EMO module 200 . The EMO modules for different equipment are daisy-chained in series into a complete circuit. Additional modules can be added very easily, as will be shown hereinafter. Power supplies 205 (e.g., +24 VDC) have their outputs 210 connected through optional diodes 215 to V+bus 220 , which is connected to the EMO switches 225 of all equipment modules. V+bus 220 provides power to the entire series of EMO modules through series linkage of all EMO switches 225 , which are connected as follows: Jumper 230 from V+bus 220 to EMO switch series circuit 235 connects V+bus 220 to a first contact 240 of the first EMO switch 225 . This contact is termed “EMO switch in”. Second contact 245 of the first EMO switch 225 is termed “EMO switch out”, and is linked to EMO switch in 240 of the second EMO switch 225 . The EMO switches are connected in the same way up through the last equipment, termed “Equipment N”. The EMO switch out for equipment N is jumped to EMO relay power bus 250 with jumper 255 . Assuming the circuit remains closed, EMO relay power bus 250 powers relay coils 260 in each module. Within each equipment module, EMO relay coil 260 is connected to EMO relay power bus 250 . When the EMO circuit is closed and EMO relay power bus 250 is powered, relay coils 260 are also powered. The powered relay coils 260 close contacts 270 which are in series with local EMO control circuits 275 in each EMO module. When contacts 270 are closed, local EMO control maintains power to the local equipment. However, if any of EMO switches 225 are activated, the EMO circuit is opened, EMO relay power 250 to each relay coil 260 is lost, and contacts 270 are opened. In this case, the local EMO control circuits 275 turn off the associated equipment under EMO mode. The serial module aspect of the inventive circuitry enables simple addition of new equipment. It may be accomplished by removing jumper 255 from Equipment N, adding an additional module 200 in series after module N, and repositioning jumper 255 after the new module. Alternatively, a new module can be inserted between two existing modules by breaking the original connections, then re-connecting to the inserted module. In either of these cases, no modification is necessary within the modules, as is necessary with the traditional circuitry.
[0009] Optional diodes 215 act as blocking diodes which prevent false EMO shutdowns if one of the power supplies 205 are off. Auxiliary contacts 280 , also controlled by relay coils 260 , may be used for controlling any equipment that does not have the inventive simplified EMO linkage designed in during EMO linkage integration. Power supply return bus 285 closes the circuit, i.e., is the return to all power supplies 210 .
[0010] The inventive EMO linkage circuit design provides simplification of test cells comprising equipment that shares energy or power hazards. The inventive EMO design utilizing equipment modules connected in series in a daisy-chain mode enables addition or movement of equipment simply, without requiring modifications within modules. Regardless of how many pieces of equipment are linked, only five signal paths are required for the EMO linkage: 1) EMO switch in; 2)EMO switch out; 3) EMO relay power; 4) power return; and 5) V+Bus. In addition, only one-contact EMO switches are needed, eliminating the need for costly and difficult-to-obtain multi-contact EMO switches, which would need to be modified if additional equipment were added.
[0011] It is not expected that the invention be restricted to the exact embodiments disclosed herein. Those skilled in the art will recognize that changes and modifications can be made without departing from the inventive concept. By way of example, details of the exact circuitry within each module may be different, while maintaining the serial modular aspects of the inventive design. The scope of the invention should be construed in view of the claims. | Disclosed herein is a simplified EMO linkage circuit that enables add-on equipment without retrofit, and eliminates the need for multi-contact EMO switches. | 5 |
CROSS REFERENCE
[0001] This application claims priority to German Patent Application No. 10 2011 112 838.0, filed Sep. 12, 2011.
BACKGROUND OF THE INVENTION
[0002] DE 44 42 850 A1 describes related art. A generic furnace would be expensive to design and would be susceptible to trouble due to the technology used for implementation of the blanks in the firing zone with the goal of reversing the direction. The same thing is also true of the cooling air supply that is used.
SUMMARY OF THE INVENTION
[0003] The object of the present invention is to design a method and/or a furnace of the type identified previously, so that it will be less susceptible to trouble and will be energy saving on the whole.
[0004] The object defined above is achieved by a method according to the invention as defined in claim 1 and by an object according to the invention as defined in claim 11 .
[0005] The method according to the invention is characterized in that the blanks to be moved in the opposite second direction B are loaded at a second end of the furnace section, which is opposite the first end with respect to the firing zone, the blanks are each moved through the firing zone on their respective furnace trains without a reversal in direction and they are unloaded from the furnace section at the end of the same, which is opposite the loading point. Due to the blanks moving past one another on both ends of the firing zone and/or waiting side by side during the standing times, the energy released by the blanks already leaving the firing zone is used for heating the blanks that have not yet entered the firing zone. There is no reversal of direction in the firing zones, so that these blanks need only pass through the firing zone. The structural complexity in the area of the firing zone is reduced accordingly. This device is less susceptible to trouble. Although the furnace section is designed to be linear in particular and a crosswise offset in the firing zone is omitted, the blanks can also be brought together slightly or guided apart in a narrower or wider firing zone, depending on the desired furnace bogie guidance.
[0006] Due to the lack of a reversal in direction and/or a turnover in the firing zone, the available space is utilized optimally. The turnover of the furnace bogies outside of the firing zone can take place more rapidly in the long run than within the firing zone in the prior art identified above, which in turn saves even more energy. The furnace according to the invention therefore also has a higher throughput than the furnace known from the prior art. A complex and susceptible turnover technology may be omitted in the high temperature range of the furnace.
[0007] The blanks in the firing zone are preferably heated by at least one heating and/or firing element arranged in a longitudinal channel between the trains. In this way, the heating energy that is used can be applied more directly to the blanks, which leads to an increased efficiency in the firing zone and also to a reduced energy consumption. The heating of the bricks or similar blanks may occur directly and uniformly over their structural height but distributed throughout the stock.
[0008] In another embodiment of the method according to the invention, the blanks are heated in the firing zone by at least one heating element arranged above the longitudinal channels. Such a design is advantageous in particular with a directed release of heating energy into the longitudinal channels between the furnace trains when there is not enough available space for heating elements in the longitudinal channels. In this case, the heating elements are then preferably arranged directly above the longitudinal channels.
[0009] The blanks of a train which are still upstream from the firing zone are preferably heated by the radiant heat of the blanks of the neighboring furnace train moving in the opposite direction in coming out of the firing zone; this occurs in radiant heat zones which are several furnace bogies long in particular and are connected along the furnace section on both ends of the firing zone. The same thing is also true of a furnace train, which is limited at both ends by furnace trains that can move in the opposite direction. Furnace bogies here are understood to refer to any type of conveyance means for raw blanks. For example, it may be a carriage or a carrier for raw blanks.
[0010] The raw blanks (not yet fired) are advantageously heated in the absence of cooling air (heated), which is passed along the furnace section and through the firing zone. This leads to great energy savings because heat losses due to cooling air that is carried away are prevented. Cooling air here is understood to refer to air that is injected to cool blanks that have already been fired in known furnaces, to absorb their heat and to release this heat downstream from the firing zone to raw blanks that have not yet been fired. Cooling air does not include secondary air, which is supplied for the purpose of enrichment of the oxygen content in the flue gas/air mixture, e.g., to produce a certain brick color. The blanks that have already been fired are also cooled in the absence of cooling air but with the heat released to the dry blanks.
[0011] There is thus no targeted guidance of the cooling air through the firing zone, and the heat that can be transported from the air/flue gas mixture in the radiant heat zone is negligible. In comparison with tunnel furnaces that operate with cooling air, the energy savings amount to as much as 40%. Due to the absence of cooling air systems, the furnace can also be manufactured less expensively and does not require as much maintenance.
[0012] The use of circulation zones on both ends of the firing zone is also particularly advantageous; in the circulation zone, air is circulated across the longitudinal direction of the furnace, achieving an equal temperature distribution among the blanks on the furnace bogie. The proportion of cross-circulated air is preferably much greater than that of air moving along the furnace section, wherein the air in the furnace is to be understood in the preceding and following discussions to refer to a flue gas or a flue gas/air mixture and/or a gas mixture. The latter gas mixture is composed of the flue gases optionally occurring in the combustion process, secondary air, if any, supplied for enrichment of oxygen to 10% to 15%, for example, as well as air optionally entering the furnace section through a lateral airlock. The ratio of cross-circulated gas mass flow to the gas mass flow directed along the furnace section is preferably >10, even more preferably >25 and especially preferably >50. Due to the great differences in the gas mass flow longitudinally and crosswise to the furnace section, it is clear that there is only a slight gas mass flow in the longitudinal direction of the furnace section. Accordingly only a small amount of heat is lost in suction removal of the flue gas/air mixture. An equal distribution of the temperature over the entire stock of all the furnace trains in parallel with one another with the blanks to be cooled and/or to be heated is the goal due to the great circulation of air in the circulation zones.
[0013] For cross-circulation, the gas mixture in the furnace is drawn in by at least one fan situated in particular above and/or at the side of the trains and is preferably guided in the crosswise direction above a wall or an intermediate ceiling of the furnace to be guided downward, as seen in the longitudinal direction of the furnace section at the side of the outer furnace trains, and to flow inward again toward the center of the furnace section through the blanks and/or through small gaps between the blanks. The natural convection tendency of the gas mixture is supported by using a fan situated above the blanks to obtain the most resistance-free flow and to minimize the labor required to do so. The fan is preferably designed as a radial fan and draws in air through a recess in an intermediate ceiling, above which the air is then guided to the end. In particular, the air is guided in a flow-optimized manner, for which purpose preferably rounded borders of the flow channel and extensive avoidance of breakaway edges or the like can take into account the contours that cause turbulence.
[0014] The alternative or supplementary arrangement of one or more fans at the ends of the furnace section, in particular with at least one on each end, can lead to especially high circulation rates with a low structural height of the furnace.
[0015] The firing curve is advantageously varied by varying the rate of the cross-circulated air in the circulation zone. In particular the firing curve, i.e., the temperature of the blanks along the furnace section, may be varied in a plurality of circulation channels arranged side by side in the circulation zone. In addition to varying the firing curve as a function of the thrust time and the gross firing temperature, the temperature of the blanks (already fired or unfired) in the circulation zone may be obtained as a function of the (crosswise) circulation rate(s) in multiple (crosswise) circulation channels. The circulation rate is preferably varied through control of the fans.
[0016] To support the shaping of organic material into blanks, oxygen may be supplied in particular in a temperature range of <700° C. along the furnace section. Ambient air is preferably used for this purpose. The proportion of air supplied is on the order of magnitude of the mass flow directed along the furnace section. The goal is to increase the oxygen content in the flue gas from 3% to 10% or 15%, for example. Oxygen may be supplied in the circulation zone, either alternatively or in addition to supplying oxygen in the combustion chamber.
[0017] The object defined in the beginning is also achieved by a furnace, which is designed in particular for performing a method according to the invention as described above or below and which is characterized in that loading of the blanks to be moved in the opposite direction, namely the second direction B, on a second end of the furnace section, which is opposite the first end with respect to the firing zone, is provided. In the furnace according to the invention, the blanks can be moved in both directions for the firing zone without having a reversal of directions, and can be unloaded at the end of the furnace section opposite its point of loading. An airlock through which the furnace bogies can travel to an a loading and unloading device, preferably having a transfer stage equipped with a number of track sections corresponding to the number of furnace trains may be provided for this purpose on both ends of the furnace section. Then the furnace bogies carrying fired and/or unfired blanks may be shifted onto the track sections of the transfer stage.
[0018] The furnace section has two radiant heat zones and in particular two circulation zones, preferably between the opposite ends with respect to the firing zone. In the radiant heat zone, there is a no cross-circulation of the air supported by fans or the like because the proportion of heat emitted via radiant heat from the fired blanks is much greater than the heat transport that can be achieved via circulation between the blanks to be cooled and those to be heated. At the same time, the proportion of cross-circulated air in the circulation zones is much greater, i.e., by at least one order of magnitude, than the proportion of air transported longitudinally in the direction of the furnace section because of the circulation means used, which is a fan in most cases. The term “air” used here is understood to refer to a corresponding mixture of flue gas, which may be combined in small portions with ambient air.
[0019] The furnace section of a furnace according to the invention has a main tunnel in which the furnace bogies can be moved in parallel furnace trains. Starting with a lateral end of the furnace section, there may be first be a circulation zone, then a radiant heat zone and a central firing zone, followed by another radiant heat zone and then another circulation zone on the other end following the firing zone. The furnace section ends after this circulation zone. The furnace trains typically run on rails through a water bath. Due to the plurality of blanks running side by side in opposite directions from one another through a shared firing zone and a shared tunnel, in the radiant heat zone, the blanks that have just come from the firing zone heat up the blanks that have not yet entered the firing zone. The blanks that have already been fired cool down. Due to the cross-circulation of the air in the tunnel in the circulation zone and the even temperature distribution, which is desired there, as seen in cross section, the blanks that have already been fired cool down further while the unfired blanks gradually heat up. Due to the absence of a reversal of direction in the firing zone, this device is technically much simpler to implement.
[0020] At the same time a cooling air feed may be omitted because the cooling of the blanks that have already been fired, said cooling taking place in the radiant heat zone and in the circulation zone due to the unfired blanks. There is no targeted cooling of the fired blanks due to additional supply of air. Any suction device or suction removal of flue gas can be designed to have smaller dimensions accordingly.
[0021] At least one fan is provided for cross-circulation of the gas that is present in the circulation zone. Such a fan may be installed either in a side wall of the main tunnel or in the ceiling. In particular, however, at least one of the circulation zones will have at least one separate wall by which the at least one circulation channel running mainly across the main tunnel is separated from a main tunnel of the furnace section. The fan may then be arranged in this wall with an inflow side toward the main tunnel. A wall and/or ceiling above the blanks and an arrangement of the fan above the blanks in this ceiling supports the transfer of circulation of air rising upward anyway, which is then transported along an outer wall of the furnace along the circulation channel toward the ends, optionally with slight cooling, and then can be introduced into the main tunnel again or through another channel section at the end, introducing it into the main tunnel directly at the end.
[0022] A plurality of circulation channels, which are separated from one another structurally, is preferably arranged in the longitudinal direction of the furnace section. To this extent, a plurality of cross-channels is formed above the main channel using an intermediate ceiling or external channels, e.g., in the form of pipes, preferably with at least one fan being assigned to each cross-channel. The use of an intermediate ceiling in particular permits systems that can be insulated well on the outside. By separate control of the fans, the temperature distribution in the zone can be controlled and the firing curve of the furnace can be designed to be variable.
[0023] In a furnace having a plurality of fans in the respective circulation zones, the arrangement of the fans is advantageously such that they are offset in relation to one another along the furnace section. In other words, they are different distances away from the longitudinal ends of the furnace section. This achieves an improved equal distribution of temperature due to a flow which reaches all the blanks.
[0024] A loading device and an unloading device are preferably arranged at both ends of the furnace section. These devices preferably each have a transfer stage, which can transfer a plurality of furnace bogies laterally in relation to the furnace section. Then the fired blanks can be transferred with a lateral offset by the furnace bogies or otherwise unloaded, and blanks to be fired can be loaded.
[0025] These aspects are merely illustrative of the innumerable aspects associated with the present invention and should not be deemed as limiting in any manner. These and other aspects, features and advantages of the present invention will become apparent from the following detailed description when taken in conjunction with the referenced drawings.
BRIEF DESCRIPTION OF THE DRAWINGS
[0026] Reference is now made more particularly to the drawings, which illustrate the best presently known mode of carrying out the invention and wherein similar reference characters indicate the same parts throughout the views.
[0027] Additional advantages and details of the invention can be derived from the following description of the figures.
[0028] The figures show schematically:
[0029] FIG. 1 a schematic top view of part of a furnace according to the invention,
[0030] FIG. 2 a cross section through another object according to the invention,
[0031] FIG. 3 a partial view of a section III-III through the object according to the invention as shown in FIG. 2 ,
[0032] FIG. 4 a loading situation,
[0033] FIG. 5 an unloading situation,
[0034] FIG. 6 a firing curve, which is varied over the variation in the cross-circulation rate in the circulation zones.
[0035] Parts which act in the same or similar ways are provided with identical reference numerals—if appropriate. Individual technical features of the exemplary embodiments, which are described below, can also lead to further embodiments of the invention having the features of the exemplary embodiments described above.
DETAILED DESCRIPTION
[0036] In the following detailed description numerous specific details are set forth in order to provide a thorough understanding of the invention. However, it will be understood by those skilled in the art that the present invention may be practiced without these specific details. For example, the invention is not limited in scope to the particular type of industry application depicted in the figures. In other instances, well-known methods, procedures, and components have not been described in detail so as not to obscure the present invention.
[0037] FIG. 1 shows a schematic and partially perspective top view of an object according to the invention. This shows a furnace section, which is labeled in general as numeral 1 , and on which a total of eight furnace trains are arranged. In the plane of the figure, furnace trains labeled with the numeral 2 travel in the direction A, i.e., to the right, while furnace trains labeled with the numeral 3 travel in the direction B, i.e., to the left. Each furnace train 2 , 3 has a plurality of furnace bogies and/or hearth furnace bogies 4 , which are arranged in a row in the longitudinal direction (A and/or B), identified partially by arrows 5 and/or 6 . The furnace bogies 4 of the furnace trains 2 are loaded at the left end in the figure and are unloaded at the right end, while the bogies with the furnace trains labeled with numeral 3 are loaded at the right end accordingly and are unloaded at the left end.
[0038] The furnace has a central firing zone 7 , in which a plurality of firing elements 8 is arranged. The lateral ends 9 and 10 of the furnace section are connected on both ends to radiant heat zones 11 which are in turn each adjacent to a circulation zone 12 .
[0039] Whereas all the blanks are heated in the firing zone 7 , the circulation zones as well as the radiant heat zones serve on the one hand to heat the blanks that have not yet been fired and on the other hand at the same time they cool the blanks that have already left the firing zone. A transition of blanks into the firing zone and/or out of the firing zone takes place by a movement of the trains arranged side by side in opposite directions. Blanks that are situated on furnace bogies 4 ′ and have left the firing zone 7 during one cycle of the furnace train are positioned next to the blanks already on the furnace bogies 4 ″ and heat is transferred from the blanks already fired to those that have not yet been fired.
[0040] After the blanks that have already been fired are cooled down to 700° C.-800° C. in the radiant heat zone, they enter one of the circulation zones 12 after repeated transfer of the trains. In each of the two circulation zones 12 there are fans 13 mounted on the ceiling with inflow openings above the blanks, creating a cross-circulation of the gases in the furnace tunnel. Arrows 14 , which are to be considered perspectively, indicate that air conveyed by the fans 13 is transported laterally to the longitudinal ends of the furnace section and is conveyed there further laterally and downward to the height of the blank. The arrangement of fans is shown in a slightly perspective arrangement where small circles 16 which have been filled in indicate the position of a fan with respect to the plane of the blanks. The blanks are loaded at both ends of the furnace section and are moved through the firing zone in both directions without any reversal of direction and without any transfer offset and then are unloaded from the furnace section at the opposite end with respect to their loading point.
[0041] The firing elements 8 , which are diagrammed schematically, are arranged between the trains in the longitudinal channels, which are not shown in greater detail, but they may also be arranged above the blanks. Due to the transfer of heat from the fired blanks to the unfired blanks and/or bricks, the bricks that have already been fired do not require extra cooling. There is no separate supply of cooling air. Nevertheless it may be appropriate to increase the oxygen content of the flue gas/air mixture to 10% to 15% by supplying a small amount of oxygen to the extent stipulated above.
[0042] With conventional tunnel furnaces, the ratio of cross-circulated mass to longitudinally circulate mass for unit of time is ≦1 but with the furnaces according to the invention, the ratio of the cross-circulated air/flue gas mixture to the air conveyed along the furnace section in the direction A or B is >50. For cross-circulation, for example, the air drawn in by one of the fans 13 and conveyed across the longitudinal extent of the furnace section is considered.
[0043] FIG. 2 shows a cross section through a circulation zone of another object according to the invention. In the exemplary embodiment presented here, twelve furnace trains 2 , 3 are arranged side by side, where numerals 1 . 1 , 1 . 2 , 2 . 1 , 2 . 2 to n. 2 denote the numbering of pairs of rails 18 . All the furnace trains 2 , 3 run in a water bath 17 , which is known per se, and run on rails 18 , which are also known per se. The furnace bogies 4 have corresponding side areas to reduce the heat input into the water bath.
[0044] In the circulation zone, there is a wall 19 , which is embodied as a ceiling through which circulation channels 22 run toward the ends 21 . Due to a fan 13 embodied as a radial fan, the flue gas/air mixture in the main tunnel 24 is conveyed in the direction of the arrows 26 . The ascending and rounded shape of the intermediate ceiling at the edges 27 improves the air flow in the circulation channel while preventing breakaway edges which lead to the formation of air turbulence. A type of ventilation grid is formed by the approximate grid-shaped stock structure of the blanks 25 arranged on the outermost right and left edges of the main tunnel 24 , so that the circulated air can flow uniformly through the blanks. Firing elements may be arranged as far as the bottom blank in the firing zone so they are arranged in the longitudinal channels between the blanks of individual bogies/trains running in opposite directions from one another.
[0045] FIG. 3 shows the cross section according to FIG. 2 . This is shown in a view that is cutaway at the right and left. It can be seen that neighboring circulation channels 22 are separated from one another by side walls 28 . In the present exemplary embodiment, a fan is provided for each circulating channel 22 , which is the length of one furnace bogie when considered in the longitudinal direction.
[0046] FIG. 4 shows the left end of the furnace section according to FIG. 1 in a loading situation and with a loading and unloading device 31 . The loading and unloading of the furnace section are performed by transfer stage 32 which has eight tracks and can move crosswise in direction C. In the situation indicated with dotted lines, the furnace bogies are loaded with unfired blanks. Next the transfer stage shifts the corresponding tracks ( 1 . 2 , 2 . 2 , 3 . 2 , n. 2 ) in direction C and the furnace bogies can be integrated into the trains 2 .
[0047] Next the transfer stage can be moved, having been offset by one track, into the position indicated with dotted lines in FIG. 5 to receive furnace bogies loaded with blanks that have already been fired. Next the transfer stage again moves into the position shown continuously in FIG. 5 , said position being next to the furnace section. In this position, the finished blanks are unloaded, whereupon dry blanks can again be placed on the bogies. The entrance into the furnace section may typically be provided with an airlock.
[0048] FIG. 6 shows the shape of two firing curves x. 1 and x. 2 as a function of the temperature (in ° C.) along the furnace section. This shows a solid line for a first track, while the firing curve for a neighboring second track is shown with dotted lines. Arrows drawn in the respective curves indicate the direction of movement of the blanks along the track. The line shown with a dotted line indicates blanks, which are moved from right to left in the plane of the figure.
[0049] The two curves have identical temperatures for the blanks in the firing zone 7 , while the temperatures dropped uniformly in the radiant heat zones 11 . The curves show a plateau on both ends of the radiant heat zones 11 due to the suitably adjusted fans for cross-circulation of the air in the circulation zones 12 , by means of which conversion processes of organic material in the blanks can be controlled in an improved manner, for example. Unloading of the blanks on both ends of the furnace section is performed at temperatures usually below 120° C.
[0050] The combustion chamber of a furnace according to the invention may also be operated as an external combustion chamber using energy sources of all types, for example, using pellets or combustible refuse, which can further improve the energy balance of the furnace.
[0051] The preferred embodiments of the invention have been described above to explain the principles of the invention and its practical application to thereby enable others skilled in the art to utilize the invention in the best mode known to the inventors. However, as various modifications could be made in the constructions and methods herein described and illustrated without departing from the scope of the invention, it is intended that all matter contained in the foregoing description or shown in the accompanying drawings shall be interpreted as illustrative rather than limiting. Thus, the breadth and scope of the present invention should not be limited by the above-described exemplary embodiment, but should be defined only in accordance with the following claims appended hereto and their equivalents. | A method for firing raw ceramic blanks in a furnace includes the steps of guiding trains of blanks running parallel to one another along a longitudinal furnace section having a firing zone, wherein the trains are moved in opposite directions during one movement operation, and the furnace is loaded using blanks to be moved in a first direction. A furnace for firing raw ceramic blanks having a plurality of trains which are arranged parallel to one another and can move along a longitudinal furnace section, so trains comprising a plurality of furnace bogies on which the blanks are to be arranged, wherein the furnace section has a firing zone, and wherein the trains are moved in opposite directions, and the furnace is at a first end of the furnace section for loading the blanks to be moved in a first direction into the furnace. | 8 |
BACKGROUND OF THE INVENTION
1. Field of the Invention
The invention relates to a hinge structure and, more particularly, to a cover hinge structure having self-protection function.
2. Description of the Related Art
As shown in FIG. 5, a conventional hinge 51, which is made of metal or plastic materials, connects a cover 52 with a body 53 by fixing the two leaves of hinge 51 onto the cover and body with screws 54. This prior hinge structure is quite durable; however, additional fixing members (not shown) for supporting the screws 54 are necessary when assembling the hinge 51, cover 52, and body 53. In addition, the hinge 51 is made separately from the cover 52 and body 53, thereby increasing the fabricating cost and complicating the assembling procedure. Besides, the screws and the additional fixing members also increase the size of a device.
Therefore, a simple hinge structure 60 shown in FIG. 6 is widely used for taking the place of the prior hinge 51. A hinge structure 60 includes a cylindrical hinge pin 61 integrated with a body 65 and a hook 62 integrated with a cover 64 (see FIG. 7A). The pin 61 is introduced into a hole 63 located at one end of the hook 62, thereby the hook 62 rotates around the pin 61 freely. When the cover 64 is lifted, the hook 62 rotates about the pin 61, thereby the cover 64 moves around the body 65. FIG. 7B shows a transformation of the hinge structure 60 shown in FIG. 7A, wherein a pin 61 is fixed on a hook 62 and a hole 63 is located at the body 65.
When assembling the hinge structure 60, the hook 62 is pulled outward slightly to let the pin 61 slip into the hole 63. After the hook 62 is released, the pin 61 is restricted within the hole 63 with the resilience of the hook 62. The hinge structure 60 is advanced in that it can be easily made with low cost and be quickly assembled. However, if the cover 64 is lifted up with great force or is continuously rotated after the pivotal motion of the cover 64 is restricted by the body 65, the pin 61 breaks at its base end. Besides, the pin 61 tends to escape from hole 63 easily.
Therefore, hinge pins with two base ends are provided to make the hinge structure more durable. Referring to FIG. 8A, a prior hinge structure 80 includes a pin 81 and a hook 82. The cylindrical hinge pin 81 connects to a body 85 at its both ends, while the hook 82 connects to the cover 84 at its base end. An engaging groove 83 forms at another end of the hook 82. As seen in FIG. 8A, an opening 86 for assembling of hinge structure 80 forms under the engaging groove 83. The width of the opening 86 is slightly larger then the diameter of the pin 81, thereby the pin 81 enters the engaging groove 83 easily by way of the opening 86 when assembling the pin 81 with the hook 82. Because of the weight of the cover 84, the hook 82 is forced downward during rotating of the cover 84, and the contact region for the pin 81 and the hook 82 is restricted between points P, Q, and R. Accordingly, undesired detachment of the pin 81 from the engaging groove 83 is prevented.
Referring to FIG. 8B, when the body 85 stops pivotal motion of the cover 84, that is, the cover 84 is lifted to the limit, since rotating direction a of the cover 84 differs from the opening direction of the opening 86 of the engaging groove 83, while the contact point A of the pin 81 and hook 82 is away from the opening 86, the pin 81 will not escape from the engaging groove 83. In addition, the conformation of the hook 82 is specially designed so that the pin 81 and the hook 82 can be detached only when they are adjusted to a particular angular range. Besides, the width of the opening 86 can be slightly smaller than the diameter of the pin 81 to avoid detachment of the pin 81 and the hook 82.
Another prior hinge structure 90 consists of a pin 91 and a hook 92, as seen in FIG. 9A. The base end of the hook 92 connects to a cover 94 and the engaging end of the hook 92 includes an extruding front jaw 98 and an extruding rear jaw 99. The front jaw 98 and rear jaw 99 are of the same length, while the opposite surfaces of both jaws are curved to jointly form a substantially C-shaped engaging groove 93 having an internal diameter substantially the same as the diameter of the pin 91. Distance between the extruding ends of the front jaw 98 and the rear jaw 99 is smaller than the diameter of the pin 91, thereby forming an opening 96 narrower than the pin 91. The hook 92 further includes an resilient slit 97 extending from the engaging groove 93 toward the base end of the hook 92. When assembling the pin 91 with the hook 92, the opening 96 is directed toward the pin 91 and the hook 92 is pressed against the pin 91. The pin 91 applies reaction forces onto the extruding ends of the front jaw 98 and the rear jaw 99, thereby pressing the front jaw 98 and the rear jaw 99 outwardly. Part of the hook 92 around the resilient slit 97 deforms outwardly, too, and the width of the opening 96 increases gradually. As the width of the opening 96 equals to the diameter of the pin 91 when the reaction forces coming from the pin 91 reaches a certain value (that is, the action force from the hook 92 to the pin 91 reaches a certain value), the pin 91 slips into the engaging groove 93. The pin 91 is held by the front jaw 98 and the rear jaw 99 since the internal diameter of the engaging groove 93 is substantially the same as the diameter of the pin 91. Because the width of the opening 96 is narrower then the diameter of the pin 91 and the hook 92 is elastic, the pin 91 stays within the engaging groove 93 during pivotal motion of the cover 94. Besides, as described above, the hook 92 is forced downward during rotating of the cover 94 because of the weight of the cover 94, and the contact region for the pin 91 and the hook 92 is restricted at the upper portion of the inner surface of the engaging groove 93. Accordingly, undesired detachment of the cover 94 from the body 95 is prevented.
However, the aforementioned hinge structures 80 and 90 may easily break down when the body stops the pivotal motion of the cover, that is, the cover is lifted to the limit. Referring now to FIG. 8B, if the cover 84 is forced to rotate after the cover 84 contacts a point B of the body 85, the rotating direction of the cover 84 points to direction a, the reaction force applied from the pin 81 to the hook 82 points to direction c and acts on a point A away from the opening 86. Thus, the hook 82 deforms. At this moment, if the applied force is large enough to make the deformation of the hook 82 exceed its elastic limit, the hook 82 is damaged or even breaks down.
On the other hand, if the hook 82 contacts point B of the body 85 after the cover 84 is lifted to the limit, as shown in FIG. 8C, the rotating direction of the cover 84 points to direction a, the reaction force applied from the pin 81 to the hook 82 points to direction e, and the opening direction of the opening 86 points to direction b. The direction b and direction e are substantially parallel; nevertheless, the reaction force applied from the pin 81 to the hook 82 acts on point C that is away from the opening 86. Therefore, undesired detachment of the pin 81 and the hook 82 is prevented. However, for the conventional plastic materials used for making the case of a device (e.g., ABS or the like), the pin 81 does not escape from the groove 83 if deformation of the hook 82 is under its elastic limit even though the reaction forces from the pin 81 deforms the hook 82 (FIG. 8D). Similarly, if the applied force is large enough to make the deformation of the hook 82 exceed its elastic limit, the hook 82 is damaged or even breaks down.
For the hinge structure 90, the hook 92 contacts a point B of the body 95 when the cover 94 is lifted to the limit, as seen in FIG. 9B. The rotating direction of the cover 94 points to direction a, the reaction force applied from the pin 91 to the hook 92 points to direction e and acts on point C of the front jaw 98. Thus, the hook 92 deforms. If the applied force is large enough to make the deformation of the hook 92 exceed its elastic limit, the hook 92 is damaged or even breaks down. In order to make the hinge structure 90 more durable, the front jaw 98 is thickened to increase its tolerance to the reaction force. However, damage or breaking down of the hinge structure remains unavoidable.
SUMMARY OF THE INVENTION
Therefore, the member of the invention is to provide a cover hinge structure having self-protection function, which can be easily made with low cost and can be easily assembled.
A cover hinge structure according to the invention consists of a cylindrical hinge pin and a hook. The hinge pin is integrated with a body wherein both ends of the pin connect to the body, while the hook is integrated with a cover at its base end. Thus the cover hinge structure according to the invention can be easily made with low cost. An engaging end of the hook includes an extruding front jaw and a rear jaw. The opposite surfaces of the front jaw and rear jaw are curved to jointly form a substantially C-shaped engaging groove having an internal diameter substantially the same as the diameter of the hinge pin. Distance between the extruding ends of the front jaw and the rear jaw is smaller than the diameter of the hinge pin, thereby forming an opening narrower than the hinge pin. The hook further includes an resilient slit extending from the middle of the bases of the front jaw and the rear jaw toward the base end of the hook. The size of the cover hinge structure according to the invention is small because of its simple construction.
The hinge structure according to the invention is characterized in that the reaction force acted by the pin on the hook directs toward the opening of the engaging groove and the direction of the reaction force is the same as the opening direction of the engaging groove of the hook when the cover is lifted to the limit. The hinge pin applies reaction forces onto the extruding ends of the front jaw and the rear jaw, thereby pressing the front jaw and the rear jaw outwardly. Part of the hook around the resilient slit deforms outwardly, too, and the width of the opening increases gradually. As the width of the opening equals to the diameter of the hinge pin when the reaction forces from the hinge pin reaches a certain value, the hinge pin slips out from the engaging groove. Therefore, the pin detaches from the hook automatically before damage to the hinge structure occurs when great force is applied.
BRIEF DESCRIPTION OF THE DRAWINGS
FIG. 1A is a schematic diagram showing a cover hinge structure according to the first embodiment of the invention.
FIG. 1B is a cross sectional view of the first embodiment of the invention taken along the line I-I' shown in FIG. 1A.
FIGS. 2A˜2D are diagrams showing the position and deformation of he cover hinge structure of FIG. 1A.
FIG. 3A is a schematic diagram showing a cover hinge structure according to the second embodiment of the invention.
FIG. 3B is a cross sectional view of the second embodiment of the invention taken along the line II-II' shown in FIG. 3A.
FIGS. 4A˜4D are diagrams showing the position and deformation of the cover hinge structure of FIG. 3A.
FIG. 5 is a diagram showing the construction of a prior hinge connecting a cover with a body.
FIG. 6 is a diagram showing the construction of another prior hinge connecting a cover with a body.
FIG. 7A is a cross sectional view taken along the line III-III' in FIG. 6 for showing one aspect of the prior hinge structure.
FIG. 7B is a cross sectional view taken along the line III-III' in FIG. 6 for showing another aspect of the prior hinge structure.
FIGS. 8A˜8D are diagrams showing another prior hinge structure.
FIGS. 9A˜9B are diagrams showing yet another prior hinge structure.
DESCRIPTION OF THE PREFERRED EMBODIMENTS
Referring to FIGS. 1A and 1B, a hinge structure 10 according to a first embodiment of the invention includes a pin 11 and a hook 12. The pin 11 is integrated with a body 15 and the hook 12 is integrated with a cover 14. The base end of the hook 12 connects to the cover 14 and the engaging end of the hook 12 includes an extruding front jaw 18 and a rear jaw 19. The opposed surfaces of both jaws are curved to form a substantially C-shaped engaging groove 13 having an internal diameter substantially the same as the diameter of the pin 11. Distance between the extruding ends of the front jaw 18 and the rear jaw 19 is smaller than the diameter of the pin 11, thereby forming an opening 16 narrower than the pin 11. The hook 12 further includes an resilient slit 17 extending from the middle of the bases of the jaws 18 and 19 toward the base end of the hook 12. FIG. 1B is a cross sectional view showing the conformation of the pin 11 and hook 12 shown in FIG. 1A.
When assembling the pin 11 with the hook 12, the opening 16 is directed toward the pin 11 and the hook 12 is pressed against the pin 11. The pin 11 applies reaction forces onto the extruding ends of the front jaw 18 and the rear jaw 19, thereby pressing the front jaw 18 and the rear jaw 19 outwardly. Part of the hook 12 around the resilient slit 17 deforms outwardly, too, and the width of the opening 16 increases gradually. As the width of the opening 16 equals to the diameter of the pin 11 when the reaction forces coming from the pin 11 reaches a certain value (that is, the action force from the hook 12 to the pin 11 reaches a certain value), the pin 11 slips into the engaging groove 13 and is held by the front jaw 18 and the rear jaw 19.
The pin 11 stays within the engaging groove 13 during pivotal motion of the cover 14 because the width of the opening 16 is smaller then the diameter of the pin 11. In addition, the hook 12 is forced downward during rotating of the cover 14 because of the weight of the cover 14, and the contact region for the pin 11 and the hook 12 is restricted at the upper portion of the inner surface of the engaging groove 13, as seen in FIG. 2A. Accordingly, undesired detachment of the cover 14 from the body 15 is prevented.
The hook 12 contacts a point B of the body 15 and rotates with taking point B as a rotating center when the cover 14 is lifted to the limit, as seen in FIG. 2B. The reaction forces applied from the pin 11 to the hook 12 point to direction e and act on the opening 16 of the engaging groove 13 (that is, on the extruding ends of both the front jaw 18 and rear jaw 19). Direction e of the reaction force is the same as the opening direction for the opening 16 of the engaging groove 13. Both the front jaw 18 and rear jaw 19 are pressed outwardly by the reaction force and the pin 11 tends to escape from the engaging groove 13 by way of the opening 16. However, resilient force of the hook 12 prevents the front jaw 18 and rear jaw 19 from being bent outwardly, thereby the hook 12 holds the pin 11 well and the cover 14 does not detach from the base 15.
Referring now to FIG. 2C, the front jaw 18 and the rear jaw 19 deform apparently if the reaction forces coming from the pin 11 is increased when additional force other then the gravity force of the cover 14 is applied to the cover 14. The resilient slit 17 deforms and the width of the opening 16 increases gradually. As the width of the opening 16 equals to the diameter of the pin 11 when the reaction forces coming from the pin 11 reaches a certain value, the pin 11 slips out from the opening 16 of the engaging groove 13 and the hook 12 detaches from the pin 11, as seen in FIG. 2D.
The force required for detaching the hook 12 from the pin 11 can be determined by controlling the thickness of the front jaw 18, the thickness of the rear jaw 19, the length and width of the resilient slit 17, and the original width of the opening 16. Deformation of every part of the hook 12 is controlled not to exceed the elastic limit, thereby forming a cover hinge structure 10 having self-protection function.
The hinge structure 10 according to the invention is different from the hinge structure 80 shown in FIGS. 8A˜8D in that the reaction force coming from the pin 11 acts on the opening 16 of engaging groove 13 when the cover 14 is lifted to the limit. For the hinge structure 80, the reaction force coming from the pin 81 is designed not to act on the opening 86 for preventing the hook 82 from detaching when the cover 84 is lifted to the limit. It is clear that the hinge structure 10 according to the invention has the function of self-protection, while the prior hinge structure 80 does not. In addition, the resilient slit 17 increases the resiliently deformable range of the hook 12, thus make the hook 12 more flexible. Besides, the hook 12 of the hinge structure 10 holds the pin 11 in the engaging groove 13 with resilient forces of the front jaw 18 and rear jaw 19, while the pin 81 is restricted by only one jaw of the hook 82.
Another hinge structure 30 according to a second embodiment of the invention is shown in FIGS. 3A and 3B. A hinge structure 30 consists of a pin 31, a pin frame 31a for supporting the pin 31, and a hook 32. Both ends of the pin 11 is fixed on one end of the pin frame 31a, while the other end of the pin frame 31a is integrated with a cover 34. The base end of the hook 32 connects to the body 35 and the engaging end of the hook 32 includes an extruding front jaw 38 and an extruding rear jaw 39. The opposed surfaces of both front jaw 38 and rear jaw 39 are curved to jointly form a substantially C-shaped engaging groove 33 having an internal diameter substantially the same as the diameter of the pin 31. Distance between the extruding ends of the front jaw 38 and the rear jaw 39 is smaller than the diameter of the pin 31, thereby forming an opening 36 narrower than the pin 31. The hook 32 further includes an resilient slit 37 extending from the middle of the bases of the jaws 38 and 39 toward the base end of the hook 32. FIG. 3B is a cross sectional view showing the conformation of the pin 31, pin frame 31a, and hook 32 shown in FIG. 3A.
The pin 31 stays within the engaging groove 33 during pivotal motion of the cover 34 because the width of the opening 36 is smaller then the diameter of the pin 31. In addition, the pin 31 is forced downward during rotating of the cover 34 because of the weight of the cover 34, and the contact region for the pin 31 and the hook 32 is restricted at the lower portion of the inner surface of the engaging groove 33 far away from the opening 36, as seen in FIG. 4A. Accordingly, undesired detachment of the cover 34 from the body 35 is prevented.
The pin frame 31a contacts a point B of the body 35 and rotates with taking point B as a rotating center when the cover 34 is lifted to the limit, as seen in FIG. 4B. The action forces applied from the pin 31 to the hook 32 point to direction e and act on the opening 36 of the engaging groove 33 (that is, the force act on the extruding ends of both the front jaw 38 and rear jaw 39). Direction e of the action force is the same as the opening direction for the opening 36 of the engaging groove 33. Both the front jaw 38 and rear jaw 39 are press outwardly by the action force and the pin 31 tends to escape from the engaging groove 33 by way of the opening 36. However, resilient force of the hook 32 prevents the front jaw 38 and rear jaw 39 from being bent outwardly, thereby the hook 32 holds the pin 31 well and the cover 34 does not detach from the base 35.
Referring now to FIG. 4C, the resilient slit 37, the front jaw 38 and the rear jaw 39 deform apparently if the action forces coming from the pin 31 increases when additional force other then the gravity force of the cover 34 is applied, and the width of the opening 36 increases gradually. As the width of the opening 36 equals to the diameter of the pin 31 when the action forces coming from the pin 31 reaches a certain value, the pin 31 slips out from the opening 36 of the engaging groove 33 of the hook 32, as seen in FIG. 4D.
Similarly, the force required for detaching the pin 31 from the hook 32 can be determined by controlling the thickness of the front jaw 38, the thickness of the rear jaw 39, the length and width of the resilient slit 37, and the original width of the opening 36. Deformation of every part of the hook 32 is controlled not to exceed the elastic limit, thereby forming a cover hinge structure 30 having self-protection function.
While the present invention has been described with reference to specific embodiments, the description is illustrative of the present invention and is not to be construed as limiting the present invention. Various modifications and applications may occur to those skilled in the art without departing from the true spirit and scope of the present invention as defined by the appended claims. | A cover hinge structure having self-protection function, which consists of a cylindrical hinge pin and a hook. The hinge pin and the hook are integrated with a body and a cover, respectively. An engaging groove with an opening narrower than the hinge pin forms at the engaging end of the hook. When the cover is lifted to the limit, the action force acted by the pin on the hook from directs toward the opening of the engaging groove and the direction of the action force is the same as the opening direction of the engaging groove. Thus, the pin detaches from the hook automatically before damage to the hinge structure occurs if great force is applied. | 8 |
CROSS-REFERENCES TO RELATED APPLICATIONS
Not Applicable
STATEMENT AS TO RIGHTS TO INVENTIONS MADE UNDER FEDERALLY SPONSORED RESEARCH OR DEVELOPMENT
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REFERENCE TO A “SEQUENCE LISTING,” A TABLE, OR A COMPUTER PROGRAM LISTING APPENDIX SUBMITTED ON A COMPACT DISK
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BACKGROUND OF THE INVENTION
The present invention relates to oximeters, and in particular to determining a pulse rate by multiple mechanisms in a detected waveform from a pulse oximeter.
Pulse oximetry is typically used to measure various blood chemistry characteristics including, but not limited to, the blood-oxygen saturation of hemoglobin in arterial blood, the volume of individual blood pulsations supplying the tissue, and the rate of blood pulsations corresponding to each heartbeat of a patient. Measurement of these characteristics has been accomplished by use of a non-invasive sensor which scatters light through a portion of the patient's tissue where blood perfuses the tissue, and photoelectrically senses the absorption of light in such tissue. The amount of light absorbed at various wavelengths is then used to calculate the amount of blood constituent being measured.
The light scattered through the tissue is selected to be of one or more wavelengths that are absorbed by the blood in an amount representative of the amount of the blood constituent present in the blood. The amount of transmitted light scattered through the tissue will vary in accordance with the changing amount of blood constituent in the tissue and the related light absorption. For measuring blood oxygen level, such sensors have typically been provided with a light source that is adapted to generate light of at least two different wavelengths, and with photodetectors sensitive to both of those wavelengths, in accordance with known techniques for measuring blood oxygen saturation.
Known non-invasive sensors include devices that are secured to a portion of the body, such as a finger, an ear or the scalp. In animals and humans, the tissue of these body portions is perfused with blood and the tissue surface is readily accessible to the sensor.
U.S. Pat. Nos. 6,083,172, 5,853,364 and 6,411,833 show multiple methods of calculating a pulse rate in a pulse oximeter, with a “best rate” module which arbitrates between the pulse rate calculations to select a best rate based on confidence levels associated with each. The confidence levels are calculated using various metrics to determine the reliability of the different pulse rate calculations. Also, U.S. Pat. No. 5,524,631 shows a fetal heart rate monitor that uses multiple parallel filter paths to identify the fetal heart rate, and uses a figure of merit operation to weight the different heart rate estimates.
N-100. The N-100 technology, dating to around 1985, accepted or rejected pulses based on pulse history of the size of pulses, pulse shape, expected time to occur (frequency) and ratio of R/IR.
In particular, the N-100 found pulses by looking for a signal maximum, followed by a point of maximum negative slope, then a minimum. The processing was done in a state machine referred to as “munch.” Each maximum was not qualified until the signal passed below a noise threshold, referred to as a noise gate. This acted as an adaptive filter since the noise gate level was set by feedback from a subsequent processing step to adapt to different expected signal amplitudes. The pulses are then accepted or rejected in a “Level3” process which was a filter which adapts to changing signals by comparing the amplitude, period and ratio-of-ratios (ratio of Red to IR, with Red and IR being expressed as a ratio of AC to DC) of a new pulse to the mean of values in a history buffer, then determining if the difference is within a confidence level. If the new pulse was accepted, the history buffer was updated with the values for the new pulse. The level3 process acted as an adaptive bandpass filter with center-frequency and bandwidth (confidence limits) being adapted by feedback from the output of the filter.
N-200. The N-200 improved on the N-100 since it could be synchronized with an ECG, and included ECG filtering. The N-200 also added interpolation to compensate for baseline shift between the time of measuring the pulse maximum and minimum. The N-200 included other filtering features as well, such as a “boxcar” filter which computed the mean of a varying number of signal samples.
The N-200, after various filtering and scaling steps, applies the digitized signals to a “boxcar” filter, which computes the mean of N samples, where N is set by feedback from a subsequent processing step according to the filtered heart rate. New samples are averaged into the boxcar filter, while the oldest samples are dropped. The boxcar length (N) is used to set three parameters: a pulse threshold, absolute minimum pulse and small pulse. An ensemble-averaging (a.k.a “slider”) filter then produces a weighted average of the new samples and the previous ensemble-averaged sample from one pulse-period earlier. The samples are then passed to a “munch” state machine and a noise gate, like the N-100. An interpolation feature is added to the N-100 process, to compensate for changes in the baseline level. Since the minimum and maximum occur at different times, a changing baseline may increase or decrease the minimum and not the maximum, or vice-versa.
“Ensemble averaging” is an integral part of C-Lock, which is NELLCOR's trademark for the process of averaging samples from multiple pulses together to form a composite pulse. This process is also known as “cardiac-gated averaging.” It requires a “trigger” event to mark the start of each pulse.
BRIEF SUMMARY OF THE INVENTION
The present invention is a pulse oximeter which determines multiple heart rates, and selects between them based on the metrics of only one of the heart rate calculations. A primary heart rate calculation method is selected, and is used unless its metrics indicate questionable accuracy, in which case an alternative rate calculation is available and is used instead.
In one embodiment, the primary heart rate calculation method does not use an ensemble averaged waveform, while the alternative heart rate calculation does use an ensemble averaged waveform. The alternative heart rate calculation is used if the primary calculation has disqualified its most recently detected pulse.
BRIEF DESCRIPTION OF THE DRAWINGS
FIG. 1 is a block diagram of an oximetry system incorporating an embodiment of the invention.
FIG. 2 is a diagram of the software processing blocks of an oximeter including an embodiment of the present invention.
FIG. 3 is a context diagram of the pulse rate calculation subsystem.
DETAILED DESCRIPTION OF THE INVENTION
FIG. 1 illustrates an embodiment of an oximetry system incorporating the present invention. A sensor 10 includes red and infrared LEDs and a photodetector. These are connected by a cable 12 to a board 14 . LED drive current is provided by an LED drive interface 16 . The received photocurrent from the sensor is provided to an I-V interface 18 . The IR and red voltages are then provided to a sigma-delta interface 20 incorporating the present invention. The output of sigma-delta interface 20 is provided to a microcontroller 22 which includes a 10-bit A/D converter. Controller 22 includes flash memory for a program, and EEPROM memory for data. The processor also includes a controller chip 24 connected to a flash memory 26 . Finally, a clock 28 is used and an interface 30 to a digital calibration in the sensor 10 is provided. A separate host 32 receives the processed information, as well as receiving an analog signal on a line 34 for providing an analog display.
Design Summary The design of the present invention is intended to deal with unwanted noise. Signal metrics are measured and used to determine filter weighting. Signal metrics are things that indicate if a pulse is likely a plethysmograph or noise, such as frequency (is it in the range of a human heart rate), shape (is it shaped like a heart pulse), rise time, etc. A similar technique was used in the Nellcor N200, described in the background of this application. The new design adds a number of different features and variations, such as the use of two ensemble averagers as claimed in the present invention.
Details of the architecture are shown in the diagram of FIG. 2 . This design calculates both the oxygen saturation, and the pulse rate, which are described separately below.
I. Oxygen Saturation Calculation.
A. Signal Conditioning—The digitized red and IR signals are received and are conditioned in this block by (1) taking the 1st derivative to get rid of baseline shift, (2) low pass filtering with fixed coefficients, and (3) dividing by a DC value to preserve the ratio. The function of the Signal Conditioning subsystem is to emphasize the higher frequencies that occur in the human plethysmograph and to attenuate low frequencies in which motion artifact is usually concentrated. The Signal Conditioning subsystem selects its filter coefficients (wide or narrow band) based on hardware characteristics identified during initialization.
Inputs—digitized red and IR signals Outputs—Pre-processed red and IR signals
B. Pulse Identification and Qualification—The low pass filtered and digitized red and IR signals are provided to this block to identify pulses, and qualify them as likely arterial pulses. This is done using a pre-trained neural net, and is primarily done on the IR signal. The pulse is identified by examining its amplitude, shape and frequency, just as was done in the Nellcor N-100. An input to this block is the average pulse period from block D. This function is similar to the N-100, which changed the upfront qualification using the pulse rate. The output indicates the degree of arrhythmia and individual pulse quality.
Inputs—(1) Pre-processed red and IR signals, (2) Ave. pulse period, (3) Lowpass Waveforms from the low pass filter. Outputs—(1) Degree of arrhythmia, (2) pulse amplitude variations, (3) individual pulse quality, (4) Pulse beep notification, (5) qualified pulse periods and age.
C. Compute Signal Quality Metrics—This block determines the pulse shape (derivative skew), period variability, pulse amplitude and variability, Ratio of Ratios variability, and frequency content relative to pulse rate.
Inputs—(1) raw digitized red and IR signals, (2) degree of arrhythmia, individual pulse quality, pulse amplitude variation (3) pre-processed red and IR signals, (4) average pulse period.
Outputs—(1) Lowpass and ensemble averaging filter weights, (2) metrics for sensor off detector, (3) Normalized Pre-processed waveforms, (4) percent modulation.
D. Average Pulse Periods. This block calculates the average pulse period from the pulses received.
Inputs—Qualified pulse periods and age. Outputs—Average pulse period.
E1. Lowpass Filter and Ensemble Averaging—Block E1 low pass filters and ensemble averages the signal conditioned by block A, and normalized by block C, for the pulse rate identification. The weights for the low pass filter are determined by the Signal Metrics block C. The signal is also ensemble averaged (this attenuates frequencies other than those of interest near the pulse rate and its harmonics), with the ensemble averaging filter weights also determined by Signal Metrics block C. Less weight is assigned if the signal is flagged as degraded. More weight is assigned if the signal is flagged as arrhythmic because ensemble-averaging is not appropriate during arrhythmia. Red and IR are processed separately, but with the same filtering weights. The filtering is delayed approximately one second to allow the signal metrics to be calculated first.
The filters use continuously variable weights. If samples are not to be ensemble-averaged, then the weighting for the previous filtered samples is set to zero in the weighted average, and the new samples are still processed through the code. This block tracks the age of the signal—the accumulated amount of filtering (sum of response times and delays in processing). Too old a result will be flagged (if good pulses haven't been detected for awhile).
Inputs—(1) normalized pre-processed red and IR signals, (2) average pulse period, (3) low pass filter weights and ensemble averaging filter weights, (4) ECG triggers, if available, (5) IR fundamental, for zero-crossing triggers. Outputs—(1) filtered red and IR signals, (2) age.
F. Estimate Filtered Waveform Correlation and Calculate Averaging Weight—this uses a noise metric similar to that used in the N100 and N200 described above, and doesn't use feedback. The variable weighting for the filter is controlled by the ratio-of-ratios variance. The effect of this variable-weight filtering is that the ratio-of-ratios changes slowly as artifact increases and changes quickly as artifact decreases. The subsystem has two response modes. Filtering in the Fast Mode targets an age metric of 3 seconds. The target age is 5 seconds in Normal Mode. In Fast Mode, the minimum weighting of the current value is clipped at a higher level. In other words, a low weight is assigned to the newest ratio-of-ratios calculation if there is noise present, and a high weight if no noise is present.
Inputs—(1) filtered red and IR signals and age, (2) calibration coefficients, (3) response mode (user speed settings). Outputs—averaging weight for ratio-of-ratios calculation.
H. Calculate Saturation—Saturation is calculated using an algorithm with the calibration coefficients and averaged ratio of ratios.
Inputs—(1) Averaged Ratio-of-Ratios, (2) calibration coefficients. Outputs—Saturation.
II. Pulse Rate Calculation.
E2. Lowpass Filter and Ensemble Averaging—Block E2 low pass filters and ensemble averages the signal conditioned by block A, for the pulse rate identification. The weights for the low pass filter are determined by the Signal Metrics block C. The signal is also ensemble averaged (this attenuates frequencies other than those of interest near the pulse rate and its harmonics), with the ensemble averaging filter weights also determined by Signal Metrics block C. Less weight is assigned if the signal is flagged as degraded. More weight is assigned if the signal is flagged as arrhythmic since filtering is not appropriate during arrhythmia. Red and IR are processed separately. The process of this block is delayed approximately one second to allow the signal metrics to be calculated first.
The filters use continuously variable weights. If samples are not to be ensemble-averaged, then the weighting for the previous filtered samples is set to zero in the weighted average, and the new samples are still processed through the code. This block tracks the age of the signal—the accumulated amount of filtering (sum of response times and delays in processing). Too old a result will be flagged (if good pulses haven't been detected for awhile).
Inputs—(1) pre-processed red and IR signals, (2) average pulse period, (3) Lowpass filter weights and ensemble averaging filter weights, (4) ECG triggers, if available, (5) IR fundamental, for zero-crossing triggers. Outputs—(1) filtered red and IR signals, (2) age.
I. Filtered Pulse Identification and Qualification—This block identifies and qualifies pulse periods from the filtered waveforms, and its results are used only when a pulse is disqualified by block B.
Inputs—(1) filtered red and IR signals and age, (2) average pulse period, (3) hardware ID or noise floor, (4) kind of sensor. Outputs—qualified pulse periods and age.
J. Average Pulse Periods and Calculate Pulse Rate—This block calculates the pulse rate and average pulse period.
Inputs—Qualified pulse periods and age Outputs—(1) average pulse period, (2) pulse rate.
III. Venous Pulsation
K. Detect Venous Pulsation—Block K receives as inputs the pre-processed red and IR signal and age from Block A, and pulse rate and provides an indication of venous pulsation as an output. This subsystem produces an IR fundamental waveform in the time domain using a single-tooth comb filter which is output to the Ensemble Averaging filters.
Inputs—(1) filtered red and IR signals and age, (2) pulse rate. Outputs—Venous Pulsation Indication, IR fundamental
IV. Sensor Off
L. Detect Sensor-Off and Loss of Pulse Amplitude—The Pulse Lost and Sensor Off Detection subsystem uses a pre-trained neural net to determine whether the sensor is off the patient. The inputs to the neural net are metrics that quantify several aspects of the behavior of the IR and Red values over the last several seconds. Samples are ignored by many of the oximetry algorithm's subsystems while the Signal State is not either Pulse Present or Sensor Maybe Off. The values of the Signal State variable are: “Pulse Present, Disconnect, Pulse Lost, Sensor Maybe Off, and Sensor Off.”
Inputs—(1) metrics, (2) front-end servo settings and ID Outputs—Signal state including sensor-off indication
Pulse Rate Calculation Subsystem
The subsystem averages qualified pulse periods from the Pulse Identification and Qualification subsystem. It outputs the average period and the corresponding pulse rate.
The oximetry algorithm contains two instances of this subsystem. The first instance receives input from the Pulse Identification and Qualification instance whose input waveform have been processed by the Signal Conditioning subsystem, then lowpass filtered, but not ensemble averaged, by the Ensemble Averaging subsystem. The second instance of the Pulse Rate Calculation subsystem receives input from two instances of the Pulse Identification and Qualification subsystem, the one described above and a second instance that receives input that has been ensemble averaged.
Selection of Pulse Period Source
One instance of the subsystem receives qualified pulse periods from two sources. The subsystem selects which of these two sources to use for its pulse rate calculation based solely on analysis of only one source, the “primary” source. The oximetry algorithm designates the Pulse Identification and Qualification instance that does NOT receive ensemble-averaged waveforms as the primary source, and designates the other Pulse Identification and Qualification instance as the “alternate” source of qualified pulse periods. Qualified pulse periods from the alternate source are only used if the most recent pulse from the primary source was rejected. When a qualified pulse period is received from the primary source, it is always used to update the pulse-rate calculation, and will prevent qualified pulse periods from the alternate source from being used until the primary source once again rejects a pulse period.
Calculation of Average Pulse Period and Pulse-Rate Estimate
When the subsystem uses a Qualified_Pulse_Period, it updates its average pulse period, Avg_Period, using a pulse-based, variable-weight IIR filter, then computes its Rate output from Avg_Period. The steps for this filtering operation are:
r t =(60/Δ t )/Qualified_Pulse_Period 1.
k =Consecutive_Qualified/max(| r t −r t−1 |, |r t−1 −r t−2 |, |r t−2 −r t−3 |, 1.0) 2.
x =bound(min(Avg_Period t−1 , Qualified_Pulse_Period), ¾ seconds, 2 seconds)/7 seconds 3.
If Rate_Age>10 seconds, x =min( x* Rate_Age/10 seconds, 0.3) 4.
k =max(1/Total_Qualified, min( k, x )) 5.
If Avg_Period t−1 < >0 Avg_Period t =Avg —Period t−1 *(Qualified_Pulse_Period/Avg_Period t−1 ) k 6.
If Avg_Period t−1 =0 Avg_Period t =Qualified_Pulse_Period 7.
Rate=(60/Δ t )/Avg_Period t 8.
Rate_Age=Rate_Age+ k* (Qualified_Period_Age−Rate_Age) 9.
where:
r t is the pulse rate corresponding to Qualified_Pulse_Period, in BPM the t−1 subscript denotes the previous qualified pulse. Δt is the oximetry algorithm's sample interval in seconds 60/Δt is the number of samples per minute x is a filter weight that targets a 7-second response time for typical adult pulse rates. k is the final filter weight, based on both x and the differences between consecutive values of r t . During the first few pulses, k is increased to at least 1/Total_Qualified so that the initial qualified pulses will be weighted equally.
Consecutive_Qualified is the number of consecutive qualified pulses, and Total_Qualified is the total number of pulses qualified since the subsystem was reinitialized. Both Consecutive_Qualified and Total_Qualified are incremented each time a Qualified_Pulse_Period is used, before k is calculated. Consecutive_Qualified is set to zero when a pulse is rejected by the pulse-period source currently in use.
The update formula for Avg_Period t , in step 6 above, is a geometric average of Avg_Period t , and Qualified_Pulse_Period. Geometric averaging helps to keep the subsystem responsive to large pulses-to-pulse period variations, and large, sustained changes in pulse rate.
Once Rate is initialized to a non-zero value, Rate_Age is incremented every sample, whether or not Rate is updated.
Context Diagram
FIG. 3 is a context diagram of the pulse rate calculation subsystem. The subsystem updates its Avg_Period and Rate outputs from Qualified_Pulse_Periods. It uses Qualified_Pulse_Periods from the Alternative_Period_Source only if it last received a Notify_Pulse_Rejected from the primary source. It updates its Rate_Age output based on Qualified_Period_Age. When Rate is updated, the subsystem sets its Pulse_Rate_Updated flag. The Reinitialize input tells the subsystem to reinitialize itself. Increment_Rate_Age notifies the subsystem to increment its Rate_Age every sample once Rate is initialized. | A pulse oximeter which determines multiple heart rates, and selects between them based on the metrics of only one of the heart rate calculations. A primary heart rate calculation method is selected, and is used unless its metrics indicate questionable accuracy, in which case an alternative rate calculation is available and is used instead. | 0 |
This application is a continuation in part of application No. 07/406,330, filed Sep. 12, 1989 now U.S. Pat. No. 5,132,322.
FIELD OF THE INVENTION
The present invention relates to compounds which are analogs of etoposide. These compounds possess antitumor activity. This invention also relates to a method for treating tumors by administering a safe and effective amount of the etoposide analog compounds.
BACKGROUND OF THE INVENTION
Podophyllotoxin is a naturally occurring compound extracted from the mandrake plant. Recently a therapeutically useful semi-synthetic glycoside of podophyllotoxin, etoposide (also known as VP-16), shown below, has been developed. ##STR5##
This compound exhibits therapeutic activity in several human neoplasms, including small cell carcinomas of the lung, testicular carcinomas, Hodgkin's disease, leukemia, lymphoma and Kaposi's Sarcoma.
It is believed that these drugs block the catalytic activity of DNA topoisomerase II by stabilizing an enzyme-DNA complex in which the DNA is cleaved and covalently linked to the enzyme. See Chen, G. L., Yang, L., Rowe T. C., Halligan, B. D., Tewey, K., and Liu, L., J. Biol. Chem., 259, 13560 (1984); Ross, W., Rowe, T., Glisson, B., Yalowich, J., and Liu, L., Cancer Res., 44, 5857 (1984); Rowe, T., Kuppfer, G., and Ross, W., Biochem. Pharmacol., 34, 2483 (1985), which are all herein specifically incorporated by reference. By way of background, topoisomerases are enzymes which control the topological state of DNA. Type II topoisomerases catalyze DNA strand passage through transient double strand breaks in the DNA. The resulting change in the linking number of DNA allows these enzymes to mediate DNA interconversions, such as supercoiling and relaxation of supercoiling, catenation and decatenation, knotting, and unknotting. See Wang, J. C., Annu. Rev. Biochem., 54, 665 (1985) and Maxwell, A., and Gellert, M., Adv. Protein Chem., 38, 69 (1986), which are herein specifically incorporated by reference.
Type II DNA topoisomerase enzymes have been shown to be involved in a number of vital cellular processes, including DNA replication and transcription, and chromosomal segregation. These enzymes, therefore, are a critical target for the action of a wide variety of anticancer drugs, including etoposide. The key step leading to cell death may be the capability of these drugs to block the catalytic activity of DNA topoisomerase II, as noted above.
Structure-activity studies have demonstrated a direct correlation between cytotoxicity, DNA breakage, and murine-derived topoisomerase II inhibition activities among the podophyllotoxin analogues. See Minocha, A., and Long, B., Biochem Res. Comm., 122, 165 (1984), which is herein specifically incorporated by reference. The isolation and purification of human type II topoisomerase from lymphocytic leukemia cells has provided the means to use this enzyme as a target to investigate the structure-activity relationships among etoposide and related congeners.
It has been shown that the substitution of etoposide's glycosidic moiety by an 4-alkoxy group, as in 4'-demethyl-epipodophyllotoxin ethyl ether, preserves the inhibitory activity of DNA topoisomerase II intact at higher concentrations. See Thurston, L.S., Irie, H., Tani, S., Han, F. S., Liu, Z. C., Cheng, Y.C., and Lee, K. H., J. Med. Chem., 29, 1547 (1986), which is herein specifically incorporated by reference. However, it has also been shown that a series of 4-acyl congeners are less active, even though some of them possessed potent cytotoxicity. See Thurston, L. S., Imakura, Y., Haruna, M., Li, D. H., Liu, Z. C./Liu, S. Y., Cheng, Y. C., and Lee, K. H., J. Med. Chem., 31, (1988), which is herein specifically incorporated by reference.
Although etoposide has been widely used at the clinical level, the development of drug resistance, myelosuppression, and poor oral bioavailability has encouraged synthesis of analogs related to etoposide which possess preferred pharmacological profiles. Previous studies by the inventors were directed at substituted amino analogs. These analogs are disclosed in U.S. patent application No. 07/313,826, filed Feb. 23, 1989, hereby incorporated by reference. These compounds are also disclosed in the literature, J. Med. Chem., 33:1364 (1990) and 33:2660 (1990). The compounds described therein have yielded numerous useful compositions which can be converted to water soluble products. Not only are many of these compounds more potent than etoposide in the inhibition of human DNA topoisomerase II and in causing protein linked DNA breakage, but these compounds also display activity against KB resistant cells.
Other etoposide analogs which possess anti-cancer activity have been disclosed in Japanese patent No. H1-197486 (August 9, 1989). The Japanese patent discloses compounds of the following formula: ##STR6## wherein R is a sugar moiety selected from arabinosyl, xyrosyl, hamnosyl, glucosyl, and 4,6-ethylene glucosyl. This patent also discloses a synthetic method for the intermediate of the formula: ##STR7## Better methods for the production of this compound have been disclosed by Lee et al. J. Nat. Prod., 52:606-13, May-June 1989. A preferred method for making this compound is also disclosed in Scheme 1 of the present application.
Another podophyllotoxin derivative synthesized in the art is 3',4'-didemethoxy-3',4'-dioxopodophyllotoxin of formula: ##STR8## Ayers and Lim disclosed the synthesis of this compound by reacting podophyllotoxin with nitric acid in Cancer Chemother. Pharmacol., 7:99 (1980). Nemec discloses a similar oxidation of Etoposide-3'4'-orthoquinone, and related compounds, in U.S. Pat. No. 4,609,664 using sodium periodate as an oxidizing agent.
SUMMARY OF THE INVENTION
The present invention provides novel etoposide analogs of formula I which exhibit antitumor activity. ##STR9##
wherein R is selected from ##STR10## wherein R 1 , R 2 , R 3 , R 4 and R 5 are each independently selected from H, CH 3 , C 2 H 5 , C 3 H 7 , i--C 3 H 7 , C 4 H 9 , CF 3 , OCH 3 , OC 2 H 5 , OC 3 H 7 , OC 4 H 9 , O--i--C 3 H 7 , O--i--C 4 H 9 , OCH 2 O, OCH 2 CH 2 O, CH 2 OH, C 2 H 4 OH, CH 2 Cl C 2 H 4 Cl, CH 2 F, C 2 H 4 F, CH 2 OCH 3 , COCH 3 , COC 2 H 5 , CO 2 CH 3 , CO 2 C 2 H 5 , NO 2 , NH 2 , NH 2 .HCl, NH 2 .HAc, NH 2 .1/2H 2 SO 4 , NH 2 .1/3H 3 PO 4 , N(CH 3 ) 2 , N(C 2 H 5 ) 2 , OH, CN, N 3 , SO 2 H, SO 2 NH 2 , SO 2 Cl, phenyl, substituted phenyl, phenoxy, substituted phenoxy, anilinyl, substituted anilinyl, cyclohexyl, piperidine, ##STR11##
wherein R 6 is selected from hydrogen, methyl, ethyl, n-propyl, i-propyl, butyl and bridged methylene;
wherein R 7 is selected from ##STR12##
More specifically, preferred compounds of the present invention are etoposide analogs wherein the glycosidic moiety is replaced by substituents which contain aryl groups. The compounds of the present invention have been shown to inhibit type II human topoisomerase and also to cause cellular protein-linked DNA breakage and, therefore, may be useful in the treatment of tumors. The compounds may also be useful in the treatment of papilloma virus.
Another aspect of the present invention is the use of the claimed compounds to treat tumors. A further aspect of the claimed invention is pharmaceutical compositions which contain the compounds of the present invention along with a pharmaceutically acceptable carrier.
A further aspect of the present invention is a process for synthesizing the compounds of the present invention.
Additional objects and advantages of the invention will be set forth in part in the description which follows, and in part will be obvious from the description, or may be learned from the practice of the invention.
DESCRIPTION OF THE PREFERRED EMBODIMENTS
Reference will now be made in detail to the preferred embodiments of the present invention, which together with the following examples, serve to explain the principles of the invention.
One aspect of the present invention is a group of compounds of formula II: ##STR13##
wherein R is ##STR14## wherein R 1 , R 2 , R 3 , R 4 and R 5 are each independently selected from H, CH 3 , C 2 H 5 , C 3 H 7 , i--C 3 H 7 , C 4 H 9 , CF 3 , OCH 3 , OC 2 H 5 , OC 3 H 7 , OC 4 H 9 , O--i--C 3 H 7 , O--i--C 4 H 9 , OCH 2 O, OCH 2 CH 2 O, CH 2 OH, C 2 H 4 OH, CH 2 Cl C 2 H 4 Cl, CH 2 F, C 2 H 4 F, CH 2 OCH 3 , COCH 3 , COC 2 H 5 , CO 2 CH 3 , CO 2 C 2 H 5 , NO 2 , NH 2 , NH 2 .HCl, NH 2 .HAc, NH 2 .1/2H 2 SO 4 , NH 2 .1/3H 3 PO 4 , N(CH 3 ) 2 , N(C 2 H 5 ) 2 , OH, CN, N 3 , SO 2 H, SO 2 NH 2 , SO 2 Cl, phenyl, substituted phenyl, phenoxy, substituted phenoxy, anilinyl, substituted anilinyl, cyclohexyl, piperidine, ##STR15##
These 4β-substituted benzylamino-4'-O-demethyl podophyllotoxins are a group of derivatives of etoposide which possess anti-cancer activity. It was surprisingly found that the activity of some of these compounds is two to ten times greater than the activity of etoposide. Table 1 illustrates the inhibitory activity of compounds of this type.
Preferred compounds of formula II are those where R is selected from benzylamino, 4"-nitro-benzylamino, 3"-nitrobenzylamino, 2"-nitrobenzylamino, 2"-fluorobenzylamino, 3"-fluorobenzylamino, 4"-fluorobenzylamino, 3"-cyanobenzylamino, 4"-cyanobenzylamino, 3",5"-dimethoxybenzylamino, 3"-aminobenzylamino, 2"-aminobenzylamino, benzoylamino, 2"-hydroxybenzoylamino, 4"-fluorobenzoylamino, 4"-acetoxybenzoylamino, 4"-acetylbenzoylamino, 3"-cyanobenzoylamino, 4"-cyanobenzoylamino, 3"-nitrobenzoylamino and 3"-aminobenzoylamino. Particularly preferred compounds of formula II are those where R is selected from 3"-fluorobenzylamino, 3"-cyanobenzylamino and 4"-cyanobenzylamino. The particularly preferred compounds demonstrate over twice the inhibition of DNA topoisomerase activity as etoposide and over twice the inhibition of cellular protein-DNA complex formation. The inhibition data for compounds of formula II is shown in tables 1 and 4.
Compounds of formula II are produced by the synthetic method disclosed in scheme 1. unlike the prior processes, which involved a difficult separation of the key intermediate (3) from its 4α-amino isomer (J. Natl Prod, 52:606 (1989); Japan Pat. HI197486). The process shown in scheme I allows the formation of the presently disclosed compounds by production of the β-isomer. This eliminates the need for the difficult separation disclosed previously.
Another aspect of the present invention is a group of compounds of formula III: ##STR16##
wherein R is ##STR17## wherein R 1 , R 2 , R 3 , R 4 and R 5 are each independently selected from H, CH 3 , C 2 H 5 , C 3 H 7 , i--C 3 H 7 , C 4 H 9 , CF 3 , OCH 3 , OC 2 H 5 , OC 3 H 7 , OC 4 H 9 , O--i--C 3 H 7 , O--i--C 4 H 9 , OCH 2 O, OCH 2 CH 2 O, CH 2 OH, C 2 H 4 OH, CH 2 Cl C 2 H 4 Cl, CH 2 F, C 2 H 4 F, CH 2 OCH 3 , COCH 3 , COC 2 H 5 , CO 2 CH 3 , CO 2 C 2 H 5 , NO 2 , NH 2 , NH 2 .HCl, NH 2 .HAc, NH 2 .1/2H 2 SO 4 , NH 2 .1/3H 3 PO 4 , N(CH 3 ) 2 , N(C 2 H 5 ) 2 , OH, CN, N 3 , SO 2 H, SO 2 NH 2 , SO 2 Cl, phenyl, substituted phenyl, phenoxy, substituted phenoxy, anilinyl, substituted anilinyl, cyclohexyl, piperidine, ##STR18##
These 4β-substituted anilinyl-3',4'-O-didemethyl podophyllotoxins are another group of derivatives of etoposide which possess anti-cancer activity. The activity of some of the preferred compounds of this type is surprisingly greater then that of etoposide itself. Table 2 illustrates the inhibitory activity of compounds of this type.
Preferred compounds of formula III are those where R is selected from anilino, 4"-fluoroanilino, 3"-hydroxyanilino, 4"-cyanoanilino, 4"-nitroanilino, 3"-methoxycarbonylanilino, and 3",4"-0-methylenedioxyanilino. A particularly preferred compound of formula III is a compound where R is selected from 4"-nitroanilino. This particularly preferred compound demonstrates over twice the inhibition of DNA topoisomerase activity as etoposide and over twice the inhibition of cellular protein-DNA complex formation.
Compounds of formula III are produced by the synthetic method disclosed in scheme 2. Ayres and Lim, in Cancer Chemother, Pharmacol., 1982, 7:99, disclosed the synthesis of 3',4'-dioxo-3',4'-didemethoxy podophyllotoxin of the following structure. ##STR19##
The enantiomer of this structure is used as an intermediate in the synthesis of the compounds of formula III. It is then reacted as shown in scheme 2 to produce the compounds of formula III.
A further aspect of the present invention are compounds of formula IV. ##STR20##
wherein R is ##STR21## wherein R 1 , R 2 , R 3 , R 4 and R 5 are each independently selected from H, CH 3 , C 2 H 5 , C 3 H 7 , i--C 3 H 7 , C 4 H 9 , CF 3 , OCH 3 , OC 2 H 5 , OC 3 H 7 , OC 4 H 9 , O--i--C 3 H 7 , O--i--C 4 H 9 , OCH 2 O, OCH 2 CH 2 O, CH 2 OH, C 2 H 4 OH, CH 2 Cl C 2 H 4 Cl, CH 2 F, C 2 H 4 F, CH 2 OCH 3 , COCH 3 , COC 2 H 5 , CO 2 CH 3 , CO 2 C 2 H 5 , NO 2 , NH 2 , NH 2 .HCl, NH 2 .HAc, NH 2 .1/2H 2 SO 4 , NH 2 .1/3H 3 PO 4 , N(CH 3 ) 2 , N(C 2 H 5 ) 2 , OH, CN, N 3 , SO 2 H, SO 2 NH 2 , SO 2 Cl, phenyl, substituted phenyl, phenoxy, substituted phenoxy, anilinyl, substituted anilinyl, cyclohexyl, piperidine, ##STR22##
wherein R 6 is selected from H, CH 3 , C 2 H 5 , C 3 H 7 , i--C 3 H 7 , and C 4 H 9 and wherein R 7 is H or CH 3 .
Preferred compounds of formula IV are those where R is selected from anilino, 4"-nitroanilino, 4"-ethoxycarbonylanilino, 4"-cyanoanilino, 4"-fluoroanilino, and 3"-hydroxyanilino; R 6 is hydrogen, and R 7 is selected from methyl and hydrogen. The results of DNA inhibition assays of DNA topoisomerase and of cellular protein-DNA complex formation inhibition, for these compounds, are shown in Table 3.
The synthesis of compounds of formula IV is shown in scheme 3. Schrier, in Helv. Chim. Acta., 47:1529 (1964) disclosed the synthesis of 6,7-0-dimethyl-6,7-0-demethylenepodophylotoxin, shown below. ##STR23## The related 6,7-dihydroxycompound serves as the intermediate in the synthesis of the compounds of formula IV, as seen in scheme 3.
Still another aspect of the present invention is compounds of formula V. ##STR24##
wherein R is ##STR25## wherein R 1 , R 2 , R 3 , R 4 and R 5 are each independently selected from H, CH 3 , C 2 H 5 , C 3 H 7 , i--C 3 H 7 , C 4 H 9 , CF 3 , OCH 3 , OC 2 H 5 , OC 3 H 7 , OC 4 H 9 , O--i--C 3 H 7 , O--i--C 4 H 9 , OCH 2 O, OCH 2 CH 2 O, CH 2 OH, C 2 H 4 OH, CH 2 Cl C 2 H 4 Cl, CH 2 F, C 2 H 4 F, CH 2 OCH 3 , COCH 3 , COC 2 H 5 , CO 2 CH 3 , CO 2 C 2 H 5 , NO 2 , NH 2 , NH 2 .HCl, NH 2 .HAc, NH 2 .1/2H 2 SO 4 , NH 2 .1/3H 3 PO 4 , N(CH 3 ) 2 , N(C 2 H 5 ) 2 , OH, CN, N 3 , SO 2 H, SO 2 NH 2 , SO 2 Cl, phenyl, substituted phenyl, phenoxy, substituted phenoxy, anilinyl, substituted anilinyl, cyclohexyl, piperidine, ##STR26##
Preferred compounds of formula V are those where R is selected from 4"-fluoroanilino, 4"-nitroanilino and 4"-ethoxycarbonylanilino. Results of the inhibition tests for these compounds are shown in table 5.
These modifications will produce changes in inhibitory activity which can be readily determined by assays known in the prior art through the exercise of routine skill in light of the teachings contained herein.
The compounds of the present invention were tested for their degree of inhibitory activity on human type II DNA topoisomerase, their effect on the formation of protein-linked DNA breakage, and their cytotoxicity. The inhibitory activity for compounds of the present invention correlated with the ability of the compounds to cause DNA strand breakage. However, the in vitro cytotoxicity of the compounds tested did not appear to correlate with the enzyme inhibitory activity and DNA strand break activity. The results of the tests on some of the compounds of the present invention are shown in Tables 1 to 5. For a description of the assays used with respect to the compounds listed in Tables 1 to 5 see Thurston, L.S., Irie, H., Tani, S., Han, F. S., Liu, Z. C., Cheng, Y.C., and Lee, K. H., Antitumor Agents 78. Inhibition of Human DNA Topoisomerase II by Podophyllotoxin and Peltatin Analogues, J. Med. Chem. 29, 1547 (1986), and the references cited therein, herein incorporated by reference.
Tables 1 to 5 illustrate the inhibitory activity, DNA strand breakage ability, as well as the cytotoxicity of etoposide and some of the compounds of the present invention.
Preparation of compounds within the scope of the present invention appear in the following examples.
EXAMPLE 1
4'-O-Demethyl-4β-azido-4-desoxypodophyllotoxin (1)
To 1.60 g (4.00 mmol) of 4'-O-Demethylepipodophyllotoxin (3) and 1.32 g (20.00 mmol) of sodium azide in 8 ml of CHCl 3 was added 4 ml trifluoroacetic acid (5.19 mmol) dropwise. The reaction mixture was stirred for 15 min. Saturated aqueous sodium bicarbonate solution was added. The organic layer was washed with water and dried over MgSO 4 . After the solvent was removed, the crude produce was purified by column chromatography (silica gel 100 g, chloroform:acetone:ethyl acetate =100:5:5) to give 1.5 g of product (94%): mp 215°-217° C., crystals from chloroform and ethyl acetate; 1 H-NMR (CDCl 3 ) 6.82 (s, 1H, 5-H), 6.60 (s, 1H, 8-H), 6.28 (s, 2H, 2',6'-H), 6.04 (s, 1H, OCHO), 6.02 (s, 1H, OCHO), 5.43 (s, 1H, OH), 4.78 (d, 1H, J=3.7Hz, 1-H), 4.64 (d, 1H, J=5.2Hz, 4-H), 4.32 (d, 2H, J=9.2Hz, 11-H 2 ), 3.79 (2, 6H, 3',5'-OCH 3 ), 3.18 (dd, 1H, J=5.1H 2 , 2-H) and 2.95 (m, 1H, 3-H); IR (KBr) 3400, 2920, 2100, 1720, 1602, and 1460 cm -1 .
EXAMPLE 2
4'-O-Demethyl-4β-amino-4-desoxypodophyllotoxin (2)
To a solution of 4 (1.5 g, 3.53 mmol) in 80 ml of ethyl acetate was added 300 mg of 10% palladium on active carbon. The mixture was stirred overnight under hydrogen. The reaction mixture was filtered and the filtrate was evaporated. The crude product was purified by column chromatography (silica gel 80 g, CHCl 3 :EtOAc=2:1 and CHCl 3 :EtOAc:MeOH=2:1:0.1) to give 1.18 of 5 (70%). The spectral data, specific rotation, and melting point of 5 are consistent with those reported (J. Natl. Prod., 1989, 52:606)
GENERAL PROCEDURE FOR THE SYNTHESIS OF EXAMPLES 3 TO 12
To a solution of substituted benzyl bromide (0.79 mmol) in acetone (3 ml) was added sodium iodide (128 mg, 0.85 mmol). The reaction mixture was stirred for 20 min and then filtered. The filtrate was evaporated to give the corresponding benzyl iodide. To compound 2 in 1,2-dichloroethane (4 ml) was added the substituted benzyl iodide (0.79 mmol) and the anhydrous barium carbonate (0.95 mmol) under nitrogen. After the mixture was stirred for 40 h at 75°-80° C., it was filtered and the organic solvent was removed. The crude product was purified by column chromatography (CHCl 3 :CH 3 COCH 3 :EtOAc=100:5:5).
EXAMPLE 3
4'-O-Demethyl-4β-benzylamino-4-desoxypodophyllotoxin:
Yield 54%; mp 180°-181° C.; crystals from chloroformethyl acetate; [α] D 25 -65° (c=0.25, CHCl 3 ); 1 H NMR (CDCl 3 ) 7.37 (m, 5H, 2", 3", 4", 5", 6"-H), 6.54 (s, 1H, 5-H), 6.48 (s, 1H, 8-H), 6.29 (s, 2H, 2',6'-H), 5.96 (s, 1H, OCHO), 5.94 (s, 1H, OCHO), 5.40 (s, 1H, OH), 4.54 (d, 1H, J=5.1 Hz, 1-H), 4.32 (m, 2H, 11-H 2 ), 3.94 (d, 1H, J=3.8 Hz, 4-H), 3.89 (d, 2H, J=2.7 Hz, NCH 2 ), 3.78 (s, 6H, 3'5'-OCH 3 ), 3.34 (dd, 1H, J=, 14.0, 5.2Hz, 2-H) and 2.82 (m,. 1H, 3-H); IR (KBr) 3300, 2850, 1760, 1590 and 1490 cm -1 .
EXAMPLE 4
4'-O-Demethyl-4β-(4"-nitrobenzylamino)-4-desoxypodophyllotoxin
Yield 48%; mp 216°-217° C.; crystals from chloroformethyl acetate; [α] D 25 -61° (c=0.25, CHCl 3 ); 1 H NMR (CDCL 3 ) δ 8.23 (d, 2H, J=8.5Hz, 3",5"-H), 7.55 (d, 2H, J=8.5Hz, 2",6"-H), 6.67 (s, 1H, 5-H), 6.52 (s, 1H, 8-H), 6.30 (s, 2H, 2',6'-H), 5.99 (s, 1H, OCHO), 5.95 (s, 1H, OCHO), 5.41 (s, 1H, OH), 4.57 (d, 1H, J=5.2Hz, 1-H), 4.29 (m, 2H, 11-H 2 ), 4.16 (d, 1H, J=14.3 Hz, NCH), 3.96 (d, 1H, J=3.9Hz, 4-H), 3.91 (d, 1H, J=14.3Hz, NCH), 3.75 (s, 6H, 3',5'-OCH 3 ), 3.32 (dd, 1H, J=, 14.0, 5.2Hz, 2-H) and 2.86 (m, 1H, 3-H); IR (KBr) 3380, 2890, 1750, 1600, 1515, 1470, 1470 and 1330 cm -1 .
EXAMPLE 5
4'-O-Demethyl-4β-(3"-nitrobenzylamino)-4-desoxypodophyllotoxin
Yield 45%; mp 196°-198° C.; crystals from chloroformethyl acetate; [α] D 25 -67° (c=0.25, CHCl 3 ); 1 H NMR (CDCl 3 ) δ 8.19 (s, 1H, 2"-H), 8.14 (d, 1H, J=8.0Hz, 4"-H), 7.70 (d, 1H, J=7.6Hz, 6"-H), 7.53 (t, 1H, J=8.0Hz, 5"-H), 6.63 (s, 1H, 5-H), 6.48 (s, 1H, 8-H), 6.26 (s, 2H, 2',6'-H), 5.99 (s, 1H, OCHO), 5.95 (s, 1H OCHO), 5.38 (s, 1H, OH), 4.54 (d, 1H, J=5.1 Hz, 1-H), 4.30 (m, 2H, 11-H 2 ), 4.12 (d, 1H, J=13.7 Hz, NCH), 3.94 (d, 1H, J=3.9Hz, 4-H), 3.88 (d, 1H, J=13.7 Hz, NCH), 3.75 (s, 6H, 3',5'-OCH 3 ), 3.28 (dd, 1H, J=14.0, 5.3Hz, 2-H) and 2.84 (m, 1H, 3-H); IR (KBr) 3360, 2900, 1760, 1610, 1470, 1520 and 130 cm -1 . Anal. Calcd for C 28 H 26 N 2 O 9 ; C, 62.92; H, 4.87; N, 5.24; found c, 62.65; H, 4.85; N. 5.19.
EXAMPLE 6
4'-O-Demethyl-4β-(2"-nitrobenzylamino)-4-desoxypodophyllotoxin
Yield 42%; mp 246°247° C.; crystals from chloroformethyl acetate; [α] D 25 -46° (c=)0.25, CHCl 3 ); 1 H NMR (CDCl 3 ) δ8.02 (d, 1H, J=)8.0Hz, 3"-H), 7.61 (m, 2H, 4",6"-H), 7.50 (t, 1H, J=8.2Hz, 5"-H), 6.64 (s, 1H, 5-H), 6.49 (s, 1H, 8-H), 6.29 (s, 2H, 2',6'-H), 5.96 (s, 1H, OCHO), 5.93 (s, 1H, OCHO), 5.41 (s, 1H, OH), 4.55 (d, 1H, J=5.2Hz, 1-H), 4.42-4.27 (m, 3H, 11-H 2 and NCH), 4.02 (m, 2H, 4-H, NCH), 3.78 (s, 6H, 3',5'-OCH 3 ), 3.31 (dd, 1H, J=14.0, 5.2 Hz, 2-H) and 2.88 (m, 1H, 3-H); IR (KBr) 3380, 2880, 1740, 1600, 1470, 1500 and 1330 cm -1 . Anal. Calcd for C 28 H 26 N 2 O 9 ; C, 62.92; H, 4.87; N, 5.24; found C. 62.85; H, 4.91; N, 5.19.
EXAMPLE 7
4-O-Demethyl-4β-(2"-fluorobenzylamino)-4-desoxypodophyllotoxin
Yield 46%; mp 174°-175° C.; crystals from chloroform-ethyl acetate; [α] D 25 -66° (c=0.25, CHCl 3 ); 1 H NMR (CDCl 3 ) δ 7.36 (m, 2H, 4",5"-H), 7.18 (m, 2H, 3",5"-H), 6.47 (s, 1H, 5-H), 6.44 (s, 1H, 8-H), 6.28 (s, 2H, 2',6'-H), 5.94 (s, 2H, OCH 2 O), 5.40 (s, 1H, OH), 4.53 (d, 1H, J=5.2 Hz, 4-H), 4.35 (d, 2H, J=5.2 Hz, 1-H), 4.35 (d, 2H, J=9.2 Hz, 11-H 2 ), 3.81 (m, 3H, 4-H and NCH 2 ), 3.78 (s, 6H, 3',5'-OCH 3 ), 3.34 (dd, 1H, J=14.0, 5.2 Hz, 2-H) and 2.83 (m, 1H, 3-H); IR (KBr) 3350, 2900, 1755, 1600, 1500 and 1475 cm -1 . Anal. Calcd. for C 28 H 26 NFO 7 ; C. 66.27; H. 5.13; N. 2.76. Found: C. 65.90; H. 5.11; N. 2.84
EXAMPLE 8
4-O-Dimethyl-4β-(3"-fluorobenzylamino)-4-desoxypodophyllotoxin
Yield 51%; mp 154°-155° C.; crystals from ethyl acetate-hexane; [α] D 25 -66 (c=0.25, CHCl 3 ); 1 H NMR (CDCl 3 ) δ 7.31 (m, 1H, 5"-H), 7.13-6.85 (m, 3H, 2",4' and 6"-H), 6.59 (s, 1H, 5-H), 6.49 (s, 1H, 8-H), 6.24 (s, 2H, 2',6'-H), 5.99 (s, 1H, OCHO), 5.95 (s, 1H, OCHO), 5.40 (s, 1H, OH), 4.55 (d, 1H, J=5.2 Hz, 1-H), 4.34 (m, 2H, 11-H 2 ), 3.85 (m, 3H, 4-H and NCH 2 ), 3.78 (s, 6H, 3',5'-OCH 3 ), 3.34 (dd, 1H, J=14.0, 5.3 Hz, 2-H) and 2.83 (m, 1H, 3-H); IR (KBr) 3390, 2905, 1760, 1610, 1520 and 1480 cm -1 . Anal. Calcd. for C 28 H 26 NFO 7 ; C. 66.27; H. 5.13; N. 2.76. Found: C. 66.12; H.5.21; N. 2.71.
EXAMPLE 9
4'-O-Demethyl-4β-(4"-fluorobenzylamino)-4-desoxypodophyllotoxin
Yield 45%; mp 148°-150° C.; crystals from ethyl acetate-hexanes; [α] D 25 -65° (c=0.25, CHCl 3 ); 1 H NMR (CDCl 3 ) δ 7.33 (m, 2H, 2",6"-H), 7.09 (m, 2H, 3",5"-H), 6.59 (s, 1H, 5-H), 6.49 (s, 1H, 8-H), 6.29 (s, 2H, 2',6'-H), 5.98 (s, 1H, OCHO), 3.94 (s, 1H, OCHO), 5.40 (s, 1H, OH), 4.54 (d, 1H, J=5.3 Hz, 1-H), 4.34 (m, 2H, 11-H 2 ), 3.90 (m, 2H, 4-H and NCH), 3.78 (m, 7H, 3',5'-OCH3 and NCH), 3.32 (dd, 1H, J=14.0, 5.2 Hz, 2-H), 2.85 (m, 1H, 3-H); IR (KBr) 3330, 2880, 1750, 1630, 1500 and 1480 cm -1 . Anal. Calcd. for C 28 H 26 NFO 7 ; C.66.27; H. 5.13 ; N. 2.76. Found. C. 66.09; H. 5.16; N. 2.74.
EXAMPLE 10
4'-O-Demethyl-4β-(3"-cyanobenzylamino)-4-desoxypodophyllotoxin
Yield 49%; mp 176°-178° C.; crystals from chloroform-ethyl acetate; [α] D 25 -66° (c=0.25, CHCl 3 ); 1 H NMR (CDCl 3 ) δ 7.61 (m, 3H, 2",4" and 6"-H), 7.48 (t, 1H, 5"-H), 6.62 (s, 1H, 5-H), 6.56 (s, 1H, 8-H), 6.28 (s, 2H, 2',6'-H), 5.97 (s, 1H, OCHO), 5.93 (s, 1H, OCHO), 5.41 (s, 1H, OH), 4.55 (d, 1H, J=5.1 Hz, 1-H), 4.26 (m, 2H, 11-H 2 ), 3.88 (m, 3H, 4-H and NCH 2 ), 3.71 (s, 6H, 3',5'-OCH 3 ), 3.30 (dd, J=14.0, 5.2 Hz, 2-H) and 2.84 (m, 1H, 3-H); IR (KBr) 3360, 2900, 2220, 1755, 1600, 1500 and 1480 cm -1 .
EXAMPLE 11
4'-O-Demethyl-4β-(4"-cyanobenzylamino)-4-desoxypodophyllotoxin
Yield 51%; mp 178°-180° C.; crystals from chloroform-ethyl acetate; [α] D 25 -64° (c=0.25, CHCl 3 ); 1 H NMR (CDCl 3 ) δ 7.65 (d, 2H, J=8.1 Hz, 3",5"-H), 7.48 (d, 2H, J=8.1 Hz, 2"6"-H), 7.26 (s, 2H, 2',6'-H), 6.64 (s, 1H, 5-H), 6.50 (s, 1H, 8-H), 5.95 (ABq, 2H, J=1.2 Hz, OCH 2 O), 5.40 (s, 1H, OH), 4.55 (d, 1H, J=5.2 Hz, 1-H), 4.31 (m, 2H, 11-H 2 ), 4.08 (d, 1H, J=14.0 Hz, NCH), 3.93 (d, 1H, J=3.9 Hz, 4-H), 3.86 (d, 1H, J=14.0 Hz, NCH), 3.75 (s, 6H, 3',5'-OCH 3 ), 3.30 (dd, 1H, J=14.0, 5.2 Hz, 2-H) and 2.84 (m, 1H, 3-H); IR (KBr) 3360, 2900, 2220, 1750, 1600, 1500 and 1450 cm -1 . Anal. Calcd. for C 29 H 26 N 2 O 7 ; C.67.70; H. 5.05; N. 5.44. Found C. 67.54; H. 5.11; N. 5.40
EXAMPLE 12
4'-O-Demethyl-4β-(3",5"-dimethoxybenzylamino)-4-desoxypodophyllotoxin
Yield 57%; mp 186°-187° C.; crystals from chloroform-ethyl acetate; [α] D 25 -65° (c=0.25, CHCl 3 ); 1H NMR (CDCl 3 ) δ 6.59 (s, 1H, 5-H), 6.51 (d, 2H, J=2.2 Hz, 2", 6"-H), 6.47 (s, 1H, 8-H), 6.41 (t, 1H, J=2.2 Hz, 4"-H), 6.28 (s, 2H, 2', 6'-H), 5.96 (s, 1H, OCHO), 5.92, (s, 1H, OCHO), 5.40 (s, 1H, OH), 4.54 (d, 1H, J=5.2 Hz, 1-H), 4.34 (m, 2H, 11-H 2 ), 3.92 (d, 1H, J=4.0 Hz, 4-H), 3.84 (s, 8H, NCH 2 and 2",6"-OCH 3 ), 3.77 (s, 6H, 2',6'-OCH 3 ), 3.32 (dd, 1H, J=14.0, 5.2 Hz, 2-H) and 2.81 (m, 1H, 3-H); Ir (KBr) 3360, 2920, 1750, 1600, 1510 and 1470 cm -1 . Anal. Calcd for C 30 H 31 NO 9 ; C. 65.57; H. 5.65; N. 2.55; Found. C. 65.23; H. 5.55; N. 2.49.
EXAMPLE 13
4'-O-Demethyl-4β-(3"-aminobenzylamino)-4-desoxypodophyllotoxin
Tin (II) chloride dihydrate 110 mg (0.5 mmol) was added to 50 mg (0.1 mmol) of 4'-O-demethyl-4β-(3"-nitrobenzylamino)-4-desoxypodophyllotoxin in ethyl acetate (2ml). After the mixture was refluxed under nitrogen for 1 h, the mixture was filtered, diluted with ethyl acetate, washed with water, dried over MgSO 4 and evaporated in vacuo. The crude product was purified by column chromatography (CH 2 Cl 2 :CH 3 CO 2 Et:MeOH=100:5:5) to give the title product; yield 75%; mp 209°-210° C.; crystals from ethyl acetate-hexane; [α] D 25 -66° (c=0.25, CHCl 3 ); 1 H NMR (CDCl 3 ) δ 7.17 (t, 1H, J=7.7 Hz, 5"-H), 6.73 (d, 1H, J=7.7 Hz, 6"-H), 6.68 (s, 1H, 2"-H), 6.64 (d, 1H, J=7.7 Hz, 4"-H), 6.56 (s, 1H, 5-H), 6.47 (s, 1H, 8-H), 6.29 (s, 2H, 2',6'-H), 5.96 (s, 1H, OCHO), 5.92 (s, 1H, OCHO), 5.40 (s, 1H, OH), 4.53 (d, 1H, J=5.1 Hz, 1-H), 4.33 (m, 2H, 11-H 2 ), 3.93 (d, 1H, J=3.9 Hz, 4-H), 3.79 (s, 6H, 3',5'-OCH 3 ), 3.34 (dd, 1H, J=12.0, 5.2 Hz, 2-H) and 2.80 (m, 1H, 3-H); IR (KBr) 3440, 3360, 2900, 1760, 1660, 1500 and 1480 cm -1 .
EXAMPLE 14
4'-O-demethyl-4β-(2"-aminobenzyl)-4-desoxypodophyllotoxin
This compound was prepared from the product of Example 6 in an analogous way as described above for the preparation of the compound of Example 13. Yield 60%; mp 138°-140° C.; crystals from ethyl acetate-hexane; [α] D 25 -85° (c=0.25, CHCl 3 ); 1 H NMR (CDCl 3 ) δ 7.15 (m, 2H, 3",5"-H), 6.75 (m, 3H, 4",6"-H and 5-H), 6.49 (s, 1H, 8-H), 6.27 (s, 2H, 2',6'-H), 5.98 (s, 1H, OCHO), 5.94 (s, 1H, OCHO), 5.40 (s, 1H, OH), 4.55 (d, 1H, J=5.2 Hz, 1-H), 4.16 (m, 2H, 11-H 2 ), 3.93 (m, 3H, 4-H and NCH 2 ), 3.78 (s, 6H, 3',5' -OCH 3 ), 3.20 (dd, 1H, J=14.0, 5.2 Hz, 2-H) and 2.84 (m, 1H, 3-H); IR (KBr) 3400, 3344, 2900, 1750, 1600, 1500 and 1470 cm -1 . Anal. Calcd for C 28 h 28 N 2 O 7 ; C. 66.67; H. 5.56; N 5.56. Found. C. 66.32; H. 5.82; N. 5.33.
EXAMPLE 15
3',4'-Didemethoxyl-3',4'-dioxoepipodophyllotoxin
A suspension of 4'-demethylepipodophyllotoxin (2.0 g, 5.0 mmol) in glacial acetic acid (25 ml) was cooled at 5° C. To which was added in one portion of a mixture of 90% nitric acid (3.0 ml) and glacial acetic acid (25 ml) precooled to 5° C. The mixture was stirred for 5 min and then poured into ice-water (500 ml). The precipitate was extracted by chloroform, and the combined organic layers were washed with brine until pH=5-6, dried (Na 2 SO 4 ), and evaporated to give the product (1.24 g 65%) after recrystallization from hexane-ethyl acetate: mp 245°-248° C.; 1 H NMR (CDCl 3 ) δ 6.83 (s, 1H, 5-H), 6.55 (s, 1H, 8-H), 6.54 (s, 1H, 6'-H), 6.02 (s, 2H, OCH 2 O), 5.21 (s, 1H, 2-H), 4.83 (d, J=3.4 Hz, 1H, 11-H), 4.52 (d, H=1.3 Hz, 1H, 4-H), 4.50 (d, J=3.4 Hz, 1H, 11-H), 4.30 (d, J=6.5 Hz, 1H, 1-H), 3.86 (s, 3H. 5'-OCH 3 ), 3.50 (dd, J=14.1, 5.6 Hz, 1H, 2-H), and 2.83 (m, 1H, 3-H); and IR (KBr) 3480, 2920, 1768, 1695, 1660, 1626, 1560, and 1485 cm -1 .
EXAMPLE 16
3',4'-O-Didemethylepipodophyllotoxin
A solution of the product of Example 15 (2.0 g, 5.2 mmol) in methanol (300 ml) was stirred with 10% pd/c (20 mg) under hydrogen at room temperature for 4 hr. The catalyst was filtered off, and the filtrate was evaporated to yield a solid, which was purified by column chromatography [Silica gel (100 g) with dichloromethane:acetone:methanol=100:10:5 as an eluant] to give 16 (1.6 g): Yield 80%; mp 220°-224° C.; crystals from methanol; [α] D 25 -116° C. (c=0.25 acetone); 1 H NMR (d 6 -acetone) δ 7.40 (d, 1H, 3'-OH), 7.32 (s, 1H, 4'-OH), 6.94 (s, 1H, 5-H), 6.52 (5, 1H, 6'-H), 6.47 (s, 1H, 8H), 5.99 (s, 2H, OCH 2 O), 5.95 (s, 1H, 2'-H), 5.62 (s 1H, 4-OH), 4.89 (d, J=3.1 Hz, 1H, 4-H), 4.52 (d, J=4.9 Hz, 1H, 1-H), 4.32 (m, 2H, 11-H), 3.73 (s, 3H, 5'-OCH 3 ), 5.28 (dd, J=14.1, 4.9 Hz, 1H, 2-H), 2.94 (m, 1H, 3-H); IR (KBr) 3460, 2900, 1740, 1605 and 1470 cm -1 .
General procedure for the synthesis of Examples 17 to 23.
A suspension containing 3',4'-O-didemethylepipodophyllotoxin (1.0 g, 2.4 mmol) in dry dichloromethane (35 ml) was kept at 0° C., and then bubbled with dry hydrogen bromide for 30 min. After removing the ice-water bath, the reaction was continued for 1 hr. the mixture was azeotropically distilled in vacuo with benzene to remove the water resulting from the reaction. The crude bromide (1.2 g) was used for next step.
A solution of the aforementioned bromide (500 mg, 1.11 mmol), anhydrous barium carbonate (439 mg, 2.33 mmol), and the appropriate substituted aniline (1.16 mmol) in 8 ml of freshly distilled THF under nitrogen was stirred overnight at room temperature. The mixture was filtered and the filtrate was evaporated to yield a solid. The solid was purified by preparative TLC (Silica gel, toluene:ethylacetate:methanol=9:3:0.2) to afford the desired products (Examples 17 to 23). The yields of these compounds from the starting material were in a range of 15-35%.
EXAMPLE 17
3',4'-O-Didemethyl-4β-anilino-4-desoxypodophyllotoxin
mp 170°-173° C.; crystals from ether; [α] D -60° (c=0.1, acetone); 1 H NMR (CDCl 3 ) δ 7.20 (t, J=7.8 Hz, 2H, 3",5"-H), 6.76 (t, J=7.8 Hz, 1H, 4"-H), 6.74 (d, J=1.8 HZ, 1H, 6'-H), 6.73 (s, 1H, 5-H), 6.51 (d, J=7.8 Hz, 2H, 2",6"-H), 6.48 (s, 1H, 8-H), 5.92 and 5.93 (s each, 2H, OCH 2 O), 5.84 (d, J=1.8 Hz, 1H,2'-H), 4.64 (dd, J=5.4, 4.4 Hz, 1H, 4-H), 4.54 (d, J=4.8 Hz, 1H,1-H), 4.35 (dd, J=8.4, 7.3 Hz, 1H, 11-H), 3.97 (dd, J=10.2, 8.4 Hz, 1H, 11-H), 3.87 (s, 3H, OCH 3 ), 3.79 (d, J=6.0 Hz, 1H, exchangeable, NH), 3.12 (dd, J=13.9, 4.6 Hz, 1H, 2-H), 3.04 (m, 1H, 3-H); IR (KBr) 3450, 3400, 1770, 1600, 1500 and 1480 cm -1 .
EXAMPLE 18
3',4'-O-didemethyl-4β-(4"-floroanilino)-4-desoxypodophyllotoxin
mp 175°-178° C.; crystals from ether; [α] D 25 -123° (c=0.3, acetone); 1 NMR (CDCl 3 ) δ 6.91 (dd, J=8.9, 8.6 Hz, 2H, 3",5"-H), 6.73 (d, J=1.5 Hz, 1H, 6'-H), 6.70 (s, 1H, 5-H), 6.44 (d, J=8.9, 4.1 Hz, 2H, 2",6"-H), 6.47 (s, 1H, 8-H), 5.92 and 5.93 (s each, 2H, OCH 2 O), 5.83 (d, J=1.5 Hz, 1H, 2'-H), 5.32-5.27(brs, 2H, 4',5'-OH) 4.54 (d, J=4.0 Hz, 1H, 4-H), 4.52 (d, J=4.7, 1H, 1-H), 4.33 (dd, J=8.2, 7.6 Hz, 1H, 11-H), 3.86 (s, 3 H, 3'-OCH 3 ), 3.95 (dd, J=9.7, 8.2 Hz, 1H, 11-H), 3.70 (brs, 1H, NH) 3.10 (dd, J=14.0, 4.9 Hz, 1H, 2-H), 3.02 (m, 1H, 3-H); IR (KBr) 3450, 3400, 1765, 1610, 1500 and 1475 cm -1 .
EXAMPLE 19
3',4'-O-Didemethyl-4β-(3"-hydroxyanilino)-4-desoxypodophyllotoxin
mp 218°-220° C., crystals from ether; [α] D 25 -64° (c=0.07, acetone); 1 H NMR (CDCl 3 ) δ 7.03 (t, J=8.0 Hz, 1H, 5"-H), 6.72 (d, overlap, 1H, 6'-H), 6.72 (s, 1H, 5-H), 6.48 (s, 1H, 8-H), 6.22 (dd, J=8.1, 2.0 Hz, 1H, 6"-H), 6.10 (dd, J=8.1, 2.0 Hz, 1H, 4"-H), 6.02 (dd, J=2.0, 1.5 Hz, 1H, 2"-H), 5.93 (brs, 2H, OCH 2 O), 5.84 (d, J=1.6 Hz, 1H, 2'-H), 5.31 (brs, 1H, 4'-OH), 5.23 (brs, 1H, 5'-OH), 4.61 (t, J=5.5 Hz, 1H, 4-H), 4.53 (d, J=4.7 Hz, 1H,1-H), 4.35 (dd, J=8.4, 7.6 Hz, 1H, 11-H), 3.98 (dd, J=10.1, 8.4 Hz, 1H, 11-H), 3.87 (s, 3H, 3'-OCH 3 ), 3.80(d, J=5.5 Hz, 1H, NH), 3.10 (dd, J=13.9, 4.7 Hz, 1H, 2-H), 3.02 (m, overlap, 1H, 3-H).
EXAMPLE 20
3',4'-O-Didemethyl-4β-(3",4"-methylenedioxyanilino)-4-desoxypodophyllotoxin
mp 181°-183° C.; crystals from ether; [α] D 25 -69° (c=0.2, acetone); 1 H NMR (CDCl 3 ) δ 6.73 (d, J=8.6 Hz, 1H, 5"-H), 6.71 (s, 1H, 5-H), 6.70 (d, J=1.7 Hz, 1H, 6'-H), 6.47 (s, 1H, 8-H), 6.05 (d, J=2.7 Hz, 1H, 2"-H), 6.03 (dd, J=8.6, 2.7 Hz, 1H, 6"-H), 5.92 and 5.93 (s each 2H, OCH 2 O), 5.85 (d, J=1.7 Hz, 1H, 2'-H), 5.36 (brs, 1H, OH), 4.53 (d, J=3.7 Hz, 1H, 4-H), 4.51 (d, J=4.8, 1H,1-H), 4.35 (dd, J=8.3, 7.5 Hz, 1H, 11-H), 4.00(dd, J=10.4, 8.3 Hz, 1H, 11-H), 3.86 (s, 3H, 3'-OCH 3 ), 4.22(m, 4H, 3",4"-OCH 2 CH 2 O--), 3.65 (brs, 1H, NH), 3.12 (dd, J=14, 5.0 Hz, 1H, 2-H), 3.00 (m, 1H, 3-H); IR (KBr) 3450, 3400, 1760, 1605, 1505 and 1475 cm -1 .
EXAMPLE 21
3'.4'-O-Didemethyl-4β-(3"-methoxycarbonylanilino)-4-desoxypodophyllotoxin
mp 167°-170° C.; crystals from ether; [α] D 25 -84° (c=0.4 acetone); 1 H NMR (CDCl 3 ) δ 7.44 (d, J=7.6 Hz, 1H, 4"-H), 7.24 (t, J=7.6 Hz, 1H, 5"-H), 7.18 (brs, 1H, 2"-H), 6.7 (m, overlap, 1H, 6"-H), 6.73 (d, J=1.8 Hz, 1H, 6'-H), 6.71 (s, 1H, 5-H), 6.49 (s, 1H, 8-H), 5.93 and 5.94 (s each, 2H, OCH 2 O), 5.84 (d, J=1.7 Hz, 1H, 2'-H), 5.27 (brs, 1H, 4'-OH), 5.16 (brs, 1H, 5'-OH), 4.76 (dd, J=5.7, 3.5 Hz 1H, 4-H), 4.54 (d, J=4.0 Hz, 1H, 1-H), 4.38 (dd, J=6.8, 6.2 Hz, 1H, 11-H), 3.90 (dd, overlap 1H, 11-H), 3.89 (s, 1H, 3"-COOCH 3 ) 3.87 (s, 3H, 3'-OCH 3 ), 3.09 (brs, overlap, 2H, 2, 3-H); IR (KBr) 3450, 3390, 1770, 1600, 1510 and 1480 cm -1 .
EXAMPLE 22
3'.4'-O-Didemethyl-4β-(4"-cyanoanilino)-4-desoxypodophyllotoxin
mp 210°-212° C., crystals from ether; [α] D 25 -114° (c=0.1, acetone); 1 H NMR (CDCl 3 ) δ 7.48 (d, J=8.7 Hz, 2H, 3",5"-H), 6.74 (d, J=1.6 Hz, 1H, 6'-H), 6.69 (s, 1H, 5-H), 6.53 (d, J=8.7 Hz, 2H, 2",6"-H), 6.50 (s, 1H, 8-H), 5.95 (s, 2H, OCH 2 O), 5.80 (d, J=1.6 Hz, 1H, 2'-H), 5.29 (s, 1H, 4'-OH), 5.24 (s, 1H, 5'-OH), 4.71 (m, 1H, NH), 4.55 (d, J=4.0 Hz, 1H, 1-H), 4.31 (dd, overlap, 1H, 11-H), 4.30 (d, overlap, 1H, 4-H), 3.87 (s, 3H, --OCH 3 ), 3.86 (dd, J=10.9, 8.7 Hz, 1H, 11-H), 3.06 (dd, J=14.0, 4.3 Hz, 1H, 2-H), 3.06 (m, overlap, 1H, 3-H); IR (KBr) 3450, 3360, 2200, 1765, 1600, 1510 and 1475 cm -1 .
EXAMPLE 23
3',4'-O-Didemethyl-4β-(4"-nitroanilino)-4-desoxypodophyllotoxin
mp 208°-210° C.; crystals from ether; [α] D 25 -105° (c=0.1 acetone) 1 H NMR (CDCl 3 ) δ 8.13 (d, J=8.9 Hz, 2H, 3",5"-H), 6.73 (d, J=1.8 HZ, 1H, 6'-H), 6.70 (s, 1H, 5-H), 6.53 (d, J=8.9 Hz, 2H, 2",6"-H), 6.51 (s, 1H, 8-H), 5.94 (s, 2H, OCH 2 O), 5.80 (d, J=1.8 Hz, 1H, 2'-H), 5.32 (s, 1H, 4'-OH), 5.21 (s, 1H, 5'-OH), 4.79 (m, 1H, NH), 4.56 (d, J=4.7 Hz, 1H, 1-H), 4.56 (d, overlap, 1H, 4-H), 4.36 (dd, J=9.0, 7.1 Hz, 1 H, 11-H), 3.87 (s, 3H, 3'-OCH 3 ), 3.85 (dd, J=11.2, 9.0 Hz, 1H, 11-H), 3.08 (m, overlap, 1H, 3-H), 3.02 (dd, J=14.3, 4.8 Hz, 1H, 2-H); IR (KBr) 3450, 3380, 1760, 1590, 1490 and 1470 cm -1 .
EXAMPLES 24 and 25
6,7-O-Demethylenepodophyllotoxin (24) and 6,7-O-demethylene-4'-O-demethylpodophyllotoxin (25)
To a dichloromethane (200 ml) solution containing boron trichloride (0.12 mole) at -70°--65° C. was added dropwise podophyllotoxin (12.4 g, 30 mmol) in CH 2 Cl 2 (for 2 hr. The reaction was continued at the same temperature for an additional 1 hr. The mixture was poured into 500 ml of ice-water, extracted with ethyl acetate. The combined organic layers were washed with brine until pH=5-6, dried (Na 2 SO 4 ), and filtered. The filtrate was evaporated to give a white solid (12.7 g). The solid was refluxed with a mixture of acetone-water-calcium carbonate (12 ml-120 ml-8 g) for 3.5 h. The white suspension was filtered off, and the filtrate was neutralized by 1N hydrochloric acid to pH=2-3, and then extracted with ethyl acetate. The combined organic layers were washed with brine, dried (Na 2 SO 4 ), and evaporated to afford a mixture of 29 and 30, which was purified by flash column chromatography [silica gel (200 g), chloroform-acetone-methanol (100-10-5)] to give 9.3 g of 24: mp 226°-228° C.; crystals from ethyl acetate; [α] D 25 -120° (c=0.5, C 2 H 5 OH); 1 H NMR (d6-acetone) δ 7.9 (brs, 2H, 6,7-OH), 7.20 (s, 1H, 5-H), 6.47 (s, 1H, 8H), 6.46 (s, 2H, 2',6'-H), 4.75 (d, J=9.7 Hz, 1H, 4-H), 4.50 (t, 2H, 11-H, and 1-H), 4.12 (t, J=10.3 Hz, 1H, 11-H), 3.68 (s, 9H, 3'4',5'-OCH 3 ), 3.04 (dd, J=14.3, 4.8 Hz, 1H, 2-H), 2.83 (m, 1H, 3-H); IR (KBr) 3518, 3400, 3000, 1760, 1578 and 1500 cm -1 .
Compound 25 was obtained from the aforementioned flash column by further elution as a white solid (0.9 g): crystals from ethyl acetate; mp 208°-211° C. (dec); [α] D 25 -101° (c=0.25. Acetone); 1 H NMR (d 6 -Acetone) δ 7.88 and 7.84 (s each, 2H, 6,7-OH), 7.19 (s, 1H, 5-H), 7.07 (s, 1H, 4'-OH), 6.47 (s, 1H, 8-H), 6.45 (s, 2H, 2',6'-H), 4.74 (d, J=9.5 Hz, 1H, 4-H), 4.71 (s, 1H, 4'-OH), 4.49 (m, 2H, 11-H and 1-H), 4.11 (t, J=10.2 Hz, 1H, 11-H), 3.69 (s, 6H, 3',5'-OCH 3 ), 2.96 (dd, J=14.2, 4.9 Hz, 1H, 2-H), 2.87 (m, 1H, 3-H); IR (KBr) 3430, 3160, 1772, 1638 and 1540 cm -1 .
GENERAL PROCEDURE FOR THE SYNTHESIS OF EXAMPLES 26-30
Through a suspension of compound 25 (5.5 g, 11.8 mmol) in dry dichloromethane (150 ml) cooled at 0°-5° C. was bubbled hydrogen bromide for 1h. The solution was azeotropically distilled with benzene to remove the water. The crude product (6.4 g) was used for the preparation of Examples 26-31.
A solution containing 25 (30 mg, 0.66 mmol), anhydrous barium carbonate (260 mg, 1.32 mmol), and the appropriate substituted aniline (0.66 mmol) in dry THF (5 ml) was stirred under nitrogen for 2-3 h at room temperature. The barium salts were filtered, and the filtrate was evaporated to dryness. The solid was purified via flash column chromatography [silica gel (10 g), TLC standard grade, toluene:ethylacetate (25:40)]. The yields were in a range of 40-80%.
EXAMPLE 26
6,7-O-Demethylene-4'-O-demethyl-4β-anilino-4-desoxypophyllotoxin
mp 150°-153° C.; crystals from ethyl acetate; [α] D 25 -112° (c=0.2, acetone); 1 H NMR (d 6 -acetone) δ 8.02 (brs, 2H, 6,7-OH), 7.13 (t, 3H, 4'-OH and 3",5"-H), 6.78 (s, 1H, 5-H), 6.72 (d, J=8.0 Hz, 1H, 4"-H), 6.62 (t, J=7.7 Hz, 2H, 2",6"-H), 6.38 (s, 1H, 2',6'-OCH 3 ), 5.19 (d, 1H, NH), 4.82 (d, J=3.9 Hz, 1H, 4-H), 4.46 (d, J=4.9 Hz, 1H, 1-H), 4.40 (t, 1H, 11-H), 3.89 (t, 1H, 11-H), 3.68 (s, 6H, 3",5"-OCH 3 ), 3.25 (dd, J=14.0, 4.9 Hz, 1H, 2-H), 3.12 (m, 1H, 3-H): IR (KBr) 3400, 3180, 1760, 1605 and 1515 cm -1 .
EXAMPLE 27
6,7-O-Demethylene-4'-O-demethyl-4β-(4"-nitroanilino)-4-desoxypodophyllotoxin
mp 185°-188° C. (dec); [α] D 25 -130° (c=0.25, acetone); 1 H NMR (D 6 -acetone) δ 8.04 (d, J=8.9 Hz, 2H, 3",5"-H), 6.89 (d, J=8.9 Hz, 2H, 2",6"-H), 6.82 (s, 1H, 5-H), 6.68 and 6.65 (s and s, 2H; 6.7-OH), 6.52 (s, 1H, 8-H), 6.37 (s, 2H, 2',6'-H), 5.13 (brs, 1H, 4-H), 4.51 (d, 1H, 1-H), 4.43 (t, 1H, 11-H), 3.85 (t, 1H, 11-H), 3.68 (s, 6H, 3',5'-OCH 3 ), 3.22 (m, 2H, 2-H and 3-H); IR (KRr) 3370, 2940, 1765, 1600, 1518 and 1320 cm -1 .
EXAMPLE 28
6,7-O-Demethylene-4'-O-demethyl-4β-[4"-(ethoxycarbonyl)anilino]-4-desoxypodophyllotoxin
mp 147°-152° C.; crystals from dichloromethane-ethyl acetate; [α] D 25 104° (c=0.5, acetone); 1 H NMR (d 6 -acetone) δ 7.99 and 7.96 (s and s, 2H, 6.7-OH), 7.83 (d, J=8.8 Hz, 2H, 3",5"-H), 7.09 (s, 1H, 4'-OH), 6.81(d, J=8.8 HZ, 2H, 2",6"-H), 6.79 (s, 1H, 5-H), 6.52 (s, 1H, 8-H), 6.40 (s, 2H, 2',6'-H), 6.02 (d, 1H, NH), 5.02 (dd, J=6.9, 2.7 Hz, 1H, 4-H), 4.50 (d, J=4.3 Hz, 1H, 1-H), 4.41 (t, J=6.7 Hz, 1H, 11-H), 3.85 (t=6.7 Hz, 1H, 11-H), 3.69 (s, 6H, 3',5'-OCH 3 ), 3.28-3.10 (m, 2H, 2-H and 3-H); IR (KBr) 3360, 2950, 1750, 1675, 1595 and 1510 cm -1 ; Anal. for C 29 H 29 NO 9 ; C, 65.04; H, 5.46; N. 2.61; Found C, 64:82; H, 5.82, N, 2.61.
EXAMPLE 29
6,7-O-Demethylene-4'-O-demethyl-4β-(cyanoanilino)-4-deoxypodophyllotoxin
mp 153°-156° C. (dec); crystals from ethylacetate-toluene; [α] D 25 -108° (c=0.5, acetone); 1 H NMR (d 6 -acetone) δ 8.08 and 8.00 (s and s, 2H, 6,7-OH), 7.50 (d, J=8.7 Hz, 2H, 3",5"-H), 7.13 (s, 1H, 4'-OH), 6.89(d, J=8.7 Hz, 2H, 2",6"-H), 6.81 (s, 1H, 5-H), 6.53 (s, 1H, 8-H), 6.38 (s, 2H, 2',6'-H), 6.21(d, J=8.6 Hz, 1H, NH), 5.03 (dd, 1H, 4-H), 4.51 (d, J=4.2 Hz, 1H, 1-H), 4.42(t, 1H, 11-H), 3.84 (dd, 1H, 11-H), 3.68(s, 6H, 3',5'-OCH 3 ), 3.20(m, 2H, 2-H and 3-H); IR (KBr) 3360, 2920, 2200, 1755, 1596 and 1510 cm -1 .
EXAMPLE 30
6,7-O-Demethylene-4'-O-demethyl-4β-(fluoroanilino)-4-desoxypodophyllotoxin
mp 151°-153° C.; crystals from ethyl acetate-toluene; [α] D 25 -80° (c=0.5 acetone); 1 H NMR (d 6 -acetone) δ 7.97 and 7.96 (s and s, 2H, 6,7-OH), 7.04(s, 1H, 4'-OH), 6.94(t, 2H, 3",5"-H), 6.86 (m, 3H, 5H and 2",6"-H), 6.51 (s, 1H, 8-H), 6.40 (s, 2H, 2',6'-H), 5.18 (d, 1H, NH), 4.80(d, J=4.1 HZ, 1H, 4-H), 4.51 (d, J=4.9 Hz, 1H, 1-H), 4.41(t, 1H, 11-H), 3.91 (t, 1H, 11-H), 3.69 (s, 6H, 3',5'-OCH 3 ), 3.26 (dd, J=13.1, 7.7 Hz, 1H, 2-H), 3.09 (m, 1H, 3-H); IR (KBr) 3400, 2950, 1755, 1615 and 1510 cm -1 .
Examples 31-33 were prepared according to the method analogous to that of examples 26-30. The yields were in the range of 25-40%.
EXAMPLE 31
6,7-O-demethylene-6,7-O-dimethyl-4'-O-demethyl-4β-(4"-fluoroanilino)-4-desoxypodophyllotoxin
mp 221°-224° C.; 1 H NMR (CDCl 3 ) δ 6.96 (t, 2H, 3"-H and 5"-H), 6.74 (s, 1H, 5-H), 6.55 (s, 1H, 8-H), 6.50 (t, 2H, 2"-H and 6"-H), 6.34 (s, 2H, 2'-H and 6'-H), 5.43 (s, 1H, 4'-OH), 4.65 (m, 2H, 1-H and 4-H), 4.39 (t, 1H, 11-H), 4.00 (t, 1H, 11-H), 3.86 (s, 3H, 6-OCH 3 ), 3.82 (s, 3H, 7-OCH 3 ), 3.75 (s, 6H, 3', 5'-OCH 3 ), 3.18 (dd, J=14.7, 4.9 Hz, 1H, 2-H), 3.01 (m, 1H, 3-H); IR (KBr) 3380, 2940, 1760, 1660, 1510 and 1460 cm -1 ; Anal. Calcd for C 28 H 28 FNO 7 1/4H 2 O: C. 65.42, H. 5.59, N. 2.27. Found C. 65.44, H. 5.75, N. 2.66.
EXAMPLE 32
6,7-O-demethylene-6,7-O-dimethyl-4'-O-demethyl-4β-(4"-cyanoanilino)-4-desoxypodophyllotoxin
mp 158°-161° C.; 1 H NMR (CDCl 3 ) δ 7.52 (d, J=8.0 Hz, 2H, 3"-H and 5"-H), 6.73 (s, 1H, 5-H), 6.60 (d, J=8.0 Hz, 2H, 2"-H and 6"-H), 6.57 (s, 1H, 8-H), 6.32 (s, 2H, 2'-H and 6'-H), 5.44 (s, 1H, 4'-OH), 4.81 (t, 1H, 4-H), 4.68 (d, J=3.6 Hz, 1H, 1-H), 4.40 (s.brs, 2H, 11-H), 3.88 (s, 3H, 6-OCH 3 ), 3.81 (s, 3H, 7-OCH 3 ), 3.79 (s, 6H, 3', 5'-OCH 3 ), 3.01 (m, 2H, 2-H and 3-H); IR (KBr) 3360, 2920, 2210, 1770, 1600, 1520 and 1460 cm -1 ; Anal. Calcd for C 29 H 28 N 2 O 7 1/2C 6 h 5 CH 3 : C.69.38, H. 5.73, N. 4.98. Found C. 69.26, H. 5.90, N. 4.79.
EXAMPLE 33
6,7-O-demethylene-6,7-O-dimethyl-4'-O-demethyl-4β-[4"-(ethoxycarbonyl)anilino]-4-desoxypodophyllotoxin
mp 125°-127° C.; 1 H NMR (CDCl 3 ) δ 7.95 (d, J=8.7 Hz, 2H, 3"-H and 5"-H), 6.76 (s, 1H, 5-H), 6.58 (d, J=8.7 Hz, 2H, 2"-H and 6"-H), 6.56 (s, 1H, 8-H), 6.33 (s, 2H, 2"-H and 6"H), 5.44 (s, 1H, 4'-OH), 4.82 (t, 1H, 4-H), 4.67 (d, J=4.5 Hz, 1H, 1-H), 4.36 (t, J=7.3 Hz, 1H, 11-H), 4.33 (q, J=7.0 Hz, 2H, CO 2 CH 2 CH 3 ), 3.94 (t, 1H, 11-H), 3.87 (s, 3H, 6-OCH 3 ), 3.82 (s, 3H, 7-OCH 3 ), 3.79 (s, 6H, 3', 5'-OCH 3 ), 3.14 (dd, J=13.3, 4.5 Hz, 1H, 2-H), 3.05 (m, 1H, 3-H), 1.38 (t, J=7.0 Hz, 3H, CO 2 CH 2 CH 3 ); IR (KBr) 3360, 2940, 1770, 1680, 1600, 1510 and 1460 cm -1 ; Anal. Calcd for C 31 H 33 NO 9 : 66.06, H. 5.90, N. 2.49. Found C. 66.23, H. 6.32, N. 2.30.
GENERAL PROCEDURE OF THE SYNTHESIS OF EXAMPLES 34-42
To a solution of appropriately substituted benzoic acid (0.25 mmol) in THF (3 ml) was added DCC (57 mg, 0.28 mmol). After 10 min, compound 2 (100 mg, 0.25 mmol) was added. After the reaction mixture was stirred overnight, it was filtered, and the filtrate was evaporated in vacuo. The crude product was purified by preparative TLC [chloroform:ethyl acetate:acetone:methanol (100:5:5:5)] to give the desired product.
EXAMPLE 34
4'-O-Demethyl-4β-(benzoylamino)-4-desoxypodophyllotoxin
Yield 73%; mp 213°-214° C.; crystals from chloroform-ethyl acetate; 1 H NMR (CDCl 3 ) δ 7.78 (d, J=7.4 Hz, 2H, 2",6"-H), 7.57-7.45 (m, 3H, 3",4",5"-H), 6.83 (s, 1H, 5-H), 6.57 (s, 1H, 8-H), 6.33 (s, 2H, 2',6'-H), 6.27 (d, J=6.8 Hz, 1H, 4-H), 6.01 and 5.99 (s and s, 2H, OCH 2 O), 5.45 (brs, 2H, NH and 4'-OH), 4.64 (d, 1H, J=4.3 Hz, 1H, 1-H), 4.51 (t, J=9.2 Hz, 1H, 11-H), 3.92 (t, J=9.2 Hz, 1H, 11-H), 3.80 (s, 6H, 3',5'-OCH 3 ), 3.06 (m, 1H, 3-H), 2.93 (dd, J=14.2, 4.8 Hz, 1H, 2-H); IR (KBr) 3500, 3300, 2910, 1750, 1720, 1610, 1500 and 1470 cm -1 .
EXAMPLE 35
4'-O-Demethyl-4β-[(2-hydroxylbenzoyl)amino]-4-desoxypodophyllotoxin
Yield 61%; mp 172°-174° C.; crystals from chloroform-ethyl acetate; 1 H NMR (CDCl 3 ) δ 7.45 (t, J=7.5 Hz, 1H, 4"-H), 7.35 (d, J=7.5 Hz, 1H, 6"-H), 7.04 (d, J=7.5 Hz, 1H, 3"-H), 6.88 (t, J=7.6 Hz, 1H, 5"-H), 6.82 (s, 1H, 5-H), 6.58 (s, 1H, 8-H), 6.47 (d, J=6.7 Hz, 1H, 4-H), 6.40 (s, 2H, 2',6'-H), 6.01 and 6.00 (s and s, 2H, OCH 2 O), 5.44 (brs, 2H, NH and 4'-OH), 4.64 (d, J=4.9 Hz, 1H, 1-H), 4.49 (t, 1H, 11-H), 3.87 (m, 1H, 11-H), 3.76 (6H, s, 3',5'-OCH 3 ), 3.05(m, 1H, 3-H), 2.96 (dd, J=14.3, 4.9 Hz, 1H, 2-H); IR (KBr) 3490, 3350, 3120, 2905 1760, 1630, 1590, 1550 and 1470 cm -1 .
EXAMPLE 36
4'-O-Demethyl-4β-[(4"-fluorobenzoyl)amino]-4-desoxypodophyllotoxin
Yield 69%; mp 242°-244° C.; crystals from chloroform-ethyl acetate; 1 H NMR (CDCl 3 ) δ δ 7.80 (m, 2H, 2",6"-H), 7.16 (m, 2H, 3",5"-H), 6.82 (s, 1H, 5-H), 6.57 (s, 1H, 8-H), 6.33 (s, 2H, 2',6'-H), 6.25 (d, J=6.8 Hz, 1H, 4-H), 6.01 and 6.00 (s and s, 2H, OCH 2 O), 5.43 (brs, 2H, NH and 4'-OH), 4.63 (d, J=4.7 Hz, 1H, 1-H), 4.50 (t, 1H, 11-H), 3.87 (m, 1H, 11-H), 3.80 (s, 6H, 3',5'-OCH 3 ), 3.04 (m, 1H, 3-H), 2.93 (dd, J=14.2, 4.7 Hz, 1H, 2-H); IR (KBr) 3410, 3120, 2910, 1760, 1630, 1590, 1510 and 1480 cm -1 ; Anal. Calcd. for C 28 H 24 NFO 8 C. 64.49; H. 4.61; N. 2.69. Found C. 64.31; H.5.09; N. 2.61.
EXAMPLE 37
4'-O-Demethyl-4β-[(4-acetoxybenoyl)amino]-4-desoxypodophyllotoxin
Yield 51%; mp 175°-176° C.; crystals from hexane-ethyl acetate; 1 H NMR (CDCl 3 ) δ 8.12 (d, J=8.7 Hz, 2H, 2",6"-H), 7.19(d, J=8.7 Hz, 2H, 3",5"-H), 6.82(S, 1H,5-H), 6.57 (s, 1H, 8-H), 6.33 (s, 2H, 2',6'-H), 6.25(d, J=6.8 Hz, 1H, 4-H), 6.01 and 6.00 (s and s, 2H, OCH 2 O), 5.43 (brs, 2H, NH and 4'-OH), 4.63 (d, J=4.7 Hz, 1H, 1-H), 4.50 (m, 1H, 11-H), 3.86 (m, 1H, 11-H), 3.76 (s, 6H, 3',5'-OCH 3 ), 3.04 (m, 1H, 3-H), 2.96 (dd, J=14.3, 4.8 Hz, 1H, 2-H), 2.33 (s, 3H, CH 3 CO 2 ), IR (KBr) 3350, 3100, 2980, 1760, 1740, 1620, 1590, 1505 and 1470 cm -1 ; Anal. Calcd for C 30 H 27 NO 10 ; C. 64.17; H. 4.81; N. 2.50. Found C. 64.01; H. 4.99; N. 2.44.
EXAMPLE 38
4'-O-Demethyl-4β-[(4"-acetylbenzoyl)]amino]-4-desoxypodophyllotoxin
Yield 70%; mp 178°-180° C. (dec), crystals from hexane-ethyl acetate; 1 H NMR (CDCl 3 ) δ 8.05 (d, J=8.2 Hz, 2H, 3",5"-H), 7.87 (d, J=8.2 Hz, 2H, 2",6"-H), 6.83 (s, 1H, 5-H), 6.58 (s, 1H, 8-H), 6.36 (m, 3H, 2',6'-H and 4-H), 6.02 and 6.00 (s and s, 2H, OCH 2 O), 5.45 (brs, 2H, NH and 4'-OH), 4.64 (d, J=4.8 Hz, 1H, 1-H), 4.51 (t, 1H, 11-H), 3.89 (m, 1H, 11-H), 3.73 (s, 6H, 3',5'-OCH 3 ), 3.06 (m, 1H, 3-H), 2.94 (dd, J=14.2, 4.8 Hz, 1H, 2 -H), 2.66 (s, 3H, CH 3 CO); IR (KBr) 3500, 3350, 2920, 1770, 1680, 1640, 1600, 1520 and 1480 cm -1 .
EXAMPLE 39
4'-O-Demethyl-4β-[(3"-cyanobenzoyl)amino]-4-desoxypodophyllotoxin
Yield 68%; mp 190°-192° C., crystals from hexane-ethyl acetate; 1 H NMR (CDCl 3 ) δ 8.06 (m, 2H, 2',6'-H), 7.84 (d, J=7.5 Hz, 1H, 4"-H), 7.62 (t, J=7.5 Hz, 1H, 5"-H), 6.82 (s, 1H, 5-H), 6.58 (s, 1H, 8-H), 6.38 (d, J=6.7 Hz, 1H, 4-H), 6.33 (s, 2H, 2',6'-H), 6.02 and 6.00 (s and s, 2H, OCH 2 O), 5.45 (brs, 2H, NH and 4'-OH), 4.64 (d, J=4.8 Hz, 1H, 1-H), 4.50 (t, 1H, 11-H), 3.87 (t, 1H, 11-H), 3.80 (s, 6H, 3',5'-OCH 3 ), 3.07 (m, 1H, 3-H), 2.94 (dd, 1H, J=14.3, 4.9 Hz, 2-H), IR (KBr) 3300, 3100, 2910, 2200, 1760, 1640, 1590, 1500 and 1470 cm -1 .
EXAMPLE 40
4'-O-Demethyl-4β-[(4"-cyanobenzoyl)amino]-4-desoxypodophyllotoxin
Yield 73%; mp 198°-202° C., crystals from chloroform-ethyl acetate; 1 H NMR (CDCl 3 ) δ 7.89 (d, J=8.5 Hz, 2H, 3",5"-H), 7.77 (d, J=8.5 Hz, 2H, 2",6"-H), 6.81 (s, 1H, 5-H), 6.58 (s, 1H, 8-H), 6.33 (m, 3H, 2",6"-H and 4-H), 6.02 and 6.00 (s and s, 1H, OCH 2 O), 5.44 (brs, NH and 4'-OH), 4.64 (d, J=5.0 Hz, 1H, 1-H), 4.50 (t, 1H, 11-H), 3.83 (t, 1H, 11-H), 3.80 (s, 6H, 3',5'-OCH 3 ), 3.06 (m, 1H, 3-H), 2.91 (dd, J=14.3, 5.0 Hz, 1H, 2-H), IR (KBr) 3320, 3100, 2980, 2200, 1760, 1640, 1600, 1500 and 1470 cm -1 .
EXAMPLE 41
4'-O-Demethyl-4β-[(3"-nitrobenzoyl)amino]-4-desoxypodophyllotoxin
Yield 80%; mp 194°-195° C., crystals from chloroform-ethyl acetate; 1 H NMR (CDCl 3 ) δ 8.58 (s, 1H, 2"-H), 8.38 (d, J=7.5 Hz, 1H, 4"-H), 8.21 (d, J=7.5 Hz, 1H, 6"-H), 7.26 (t, 5"-H), 6.82 (s, 1H, 5-H), 6.54 (m, 2H, 4-H and 8-H), 6.32 (s, 2H, 2',6'-H), 6.00 (s, 2H OCH 2 O), 5.45 (brs, 2H, NH and 4'-OH), 4.62 (d, J=4.7 Hz, 1H, 1-H), 4.49 (t, 1H, 11-H), 3.87 (t, 1H, 11-H), 3.80 (s, 6H, 3',5'-OCH 3 ), 3.08 (m, 1H, 3-H), 2.96 (dd, J= 14.4, 4.8 Hz, 1H, 2-H), IR (KBr) 3320, 3100, 2980, 2200, 1760, 1640, 1600, 1500 and 1470 cm -1 .
EXAMPLE 42
4'-O-Demethyl-4β-[(3"-aminobenzoyl)amino]-4-desoxypodophyllotoxin
A solution of the product from Example 41 (25 mg. 0.05 mmol) in ethyl acetate (3.0 ml) was stirred under hydrogen in the presence of 10% Pd/C (3 mg) at room temperature for 2 hr. The catalyst was removed by filtration, and the filtrate was evaporated to afford the desired product (20 mg): Yield 95%; mp 180°-182° C., crystals from chloroform-ethyl acetate; 1 H NMR δ 7.20 (t, J=7.6 Hz, 1H, 5"-H), 7.11 (s, 1H, 2"-H), 7.02 (d, J=7.6 Hz, 1H, 6"-H), 6.82 (m, 2H, 4"-H and 5-H), 6.55 (s, 1H, 8-H) 6.32 (s, 2H, 2',6'-H), 5.98 (d, J=5.1 Hz, 1H, 4-H), 5.99 and 5.97 (s and s, 2H, OCH 2 O), 5.40 (brs, 2H, NH and 4'-OH), 4.61 (d, J=4.6 Hz, 1H, 1-H), 4.48 (t, 1H, 11-H), 3.85 (m, 1H, 11-H), 3.79 (s, 6H, 3',5 '-OCH 3 ), 3.01 (m, 1H, 3-H), 2.90 (dd, J=14.3, 4.9 Hz, 1H, 2-H), IR (KBr) 3360, 3120, 2920, 1760, 1640, 1600, 1570 and 1460 cm -1 ; Anal. Calcd for C 28 H 26 N 2 O 8 ; C,64.86; H, 5.02; N. 5.41. Found C,64.73; H, 5.24; N, 5.25.
GENERAL PROCEDURE FOR THE SYNTHESIS OF EXAMPLES 43 TO 45
To a solution of the compounds from examples 18, 21 and 23 (0.1 mmol) in ether (0.5 ml) was added tetrachloro-1,2-benzoquinone (0.15 mmol) in ether (0.5 ml) at room temperature. After stirring for 10 min., the reaction mixture was filtered, and the solid was collected, washed with ether, and dried to give the compounds described in examples 43 to 45 with a range of yields of 90 to 100%.
EXAMPLE 43
3',4'-Didemethoxy-3',4'-dioxo-4β-(4"-fluoroanilino)-4-desoxypodophyllotoxin
mp 193°-194° C. (dec), crystals from ether; 1 H NMR (CDCl 3 ) δ 6.93 (dd, J=8.6, 8.4 Hz, 2H, 3",5"-H), 6.69 (s, 1H, 5-H), 6.51 (s, 1H, 6'-H), 6.50 (s, 1H, 8-H), 6.45 (dd, J=8.6, 4.2 Hz, 2H, 2",6"-H), 5.99 and 5.97 (s and s, 2H, OCH 2 O), 5.26 (s, 1H, 2'-H), 4.53 (dd, 1H, 11-H), 4.52 (brs, 1H, 4-H), 4.26 (d, J=5.4 Hz, 1H, 1-H), 4.10 (dd, 1H, 11-H), 3.83 (s, 3H, 5'-OCH 3 ), 3.32 (dd, J=14.0, 5.6 Hz, 1H, 2-H), 2.98 (m, 1H, 3-H), IR (KBr) 3380, 1760, 1685, 1650, 1620, 1550, 1495 and 1475; FAB MS m/3 (relative intensity) 478 (M+1)+.
EXAMPLE 44
3',4'-Didemethoxy-3',4'-dioxo-4β-(4"-nitroanilino)-4-desoxypodophyllotoxin
mp 234°-236° C. (dec), crystals from ether; 1 H NMR (CDCl 3 ) δ 8.14 (d, J=9.1 Hz, 2H, 3",5"-H), 6.70 (s, 1H, 5-H), 6.56 (d, J=9.1 Hz, 2H, 2",641 -H), 6.53 (s, 1H, 8-H), 6.50 (s, 1H, 6'-H), 6.00 and 5.98 (s and s, 2H, OCH 2 O), 5.25 (s, 1H, 2'-H), 4.78 (dd, J=6.7, 4.0 Hz, 1H, 4-H), 4.56 (dd, J=10.6, 8.2 Hz, 1H, 11-H), 4.54 (d, 1H, NH), 4.29 (d, J=5.6 Hz, 1H, 1-H), 3.98 (dd, J=10.6, 9.1 Hz, 1H, 11-H), 3.83 (s, 3H, 5-OCH 3 ), 3.25 (dd, J=14.2, 5.6 Hz, 1H, 2-H), 3.06 (m, 1H, 3-H), IR (KBr) 3360, 1760, 1685, 1650, 1615, 1590, 1550, 1492 and 1475 cm -1 ; FAB MS m/3 (relative intensity) 505 (M+1)+.
EXAMPLE 45
3',4'-Didemethoxy-3',4'-dioxo-4β-[(4"-ethoxycarbonyl)anilino]-4-desoxypodophyllotoxin
mp 205°-208° C. (dec), crystals from ether; 1 H NMR (CDCl 3 ) δ 7.92 (d, J=8.6 Hz, 2H, 3",5"-H), 6.71 (s, 1H, 5-H), 6.52 (d, J=8.6 Hz, 2H, 2",6"-H), 6.51 (s, 1H, 8-H), 6.50 (s, 1H, 6'-H), 5.99 and 5.97 (s and s, 2H, OCH 2 O), 5.26 (s, 1H, 2'-H), 4.72 (brs, 1H, 4-H), 4.54 (dd, 1H, 11-H), 4.32 (9, J=7.2 Hz, 2H, 4"-CO 2 CH 2 CH 3 ), 4.28 (d, J=5.2 Hz, 1H, 1-H), 3.98 (dd, 1H, 11-H), 3.83 (s, 3H, 5'-OCH 3 ), 3.28 (dd, J=14.1, 5.5 Hz, 1H, 2-H), 3.02 (m, 1H, 3-H), 1.36 (t, J=7.2 Hz, 3H, 4"-CO 2 CH 2 CH 3 ); FAB MS m/3 (relative intensity) 532 (M+1)+.
ISOLATION OF HUMAN DNA TOPOISOMERASE II
Human DNA topoisomerase II was isolated from peripheral blast cells of a patient with acute leukemia. The isolation procedure is described in Thurston, L., Imakura, Y., Haruna, M., Li, Z. C., Liu, S. Y., and Lee, K. H., J. Med. Chem., 31, COMPLETE (1988) and is a partial combination of the procedure described in Goto, T., Laiapia, P. and Wang, J., J. Biol. Chem., 259, 10422 (1984) and Halligan, B., Edwards, K., and Liu, L., J. Biol. Chem., 260, 2475 (1985) which are herein specifically incorporated by reference.
PREPARATIONS OF DRUGS
Drugs were dissolved in Me 2 SO at a concentration of 20 mM as the stock solution and diluted before use with water to the desired concentration of each drug.
DNA TOPOISOMERASE II ASSAY
The P4 unknotting reaction was a modification of the procedure described by Hseih, T., J. Biol. Chem., 258, 8413 (1985), which is herein specifically incorporated by reference.
The reaction mixture (20 μL), which contained 50 mM HEPES, pH 7.0, 50 mM KCI, 100 mM NaCl, 0.1 mM EDTA, 10 mM MgCl 2 , 1.0 mM ATP, 50 μg/mL bovine serum albumin, 0.4 μg P4knotted DNA, and enzyme, was incubated with or without drugs.
The reaction mixture was incubated at 37° C. for 30 min and terminated by adding 5.0 μl of a stop solution (2% sodium dodecyl sulfate, 20% glycerol, 0.05% bromophenol blue). These samples were loaded onto a 1% agarose gel and electrophoresed at 55 V overnight with an electrophoresis buffer that contained 90 mM Tris-boric acid, pH 8.3, and 2.5 mM EDTA. At completion, the gel was stained in 0.5 μg/mL of ethidium bromide. Then a photograph was taken of the DNA bands visualized with fluorescence induced by a long-wavelength UV lamp. The data reported in Table 1 reflect a 100 μM drug concentration.
K-SDS PRECIPITATION ASSAY FOR PROTEIN-DNA COMPLEXES
The intracellular formation of covalent topoisomerase II-DNA complexes was quantitated using the potassium SDS precipitation assay, a procedure adapted from the method described in Rowe, T. C., Chen, G. L., Hsiang, Y. H., and Liu, L., Cancer Res., 46, 2021 (1986) (hereinafter Rowe et al.), which is herein specifically incorporated by reference. KB ATCC cells were prelabeled with 0.05 mCi/ml 14 C-thymidine (specific activity 50.5 mCi/mmol) for 18 hr. A final concentration of 5×10 5 cells/sample were treated with 10 μM of the drugs at 37° C. for 1 hr and proceeded according to the procedure described by Rowe et al. to detect the protein linked DNA levels.
It will be apparent to those skilled in the art that various modifications and variations can be made in the processes and products of the present invention. Thus, it is intended that the present invention cover the modifications and variations of this invention provided that they come within the scope of the appended claims and their equivalents.
TABLE 1__________________________________________________________________________Biological Evaluation of 4β-substituted benzylaminoPodophphylloyoxins ##STR27## Inhibition of Cellular DNA Topo- Protein-DNA isomerase II Complex Cytotoxicity.sup.a Activity.sup.b FormationexampleR ID.sub.50 KB(μM) ID.sub.50 (%) 10 μM__________________________________________________________________________etoposide ##STR28## 0.20 50 100 ##STR29## 2.20 25 1804 ##STR30## 0.40 50 2155 ##STR31## <0.40 25 1296 ##STR32## 1.80 50 1437 ##STR33## 1.90 100 1258 ##STR34## 3.00 25 2159 ##STR35## >4.00 50 16810 ##STR36## <0.40 25 22411 ##STR37## <0.40 25 28312 ##STR38## 1.70 100 14313 ##STR39## <0.40 25 19014 ##STR40## <0.40 25 183__________________________________________________________________________ .sup.a ID.sub.50 was the concentration of drug which affords 50% reductio in cell number after three day incubation. .sup.b Each compound was examined with three concentrations at 25, 50, an 100 μM. The ID.sub.50 value was established based on the degree of inhibition at these three concentrations.
TABLE 2__________________________________________________________________________Biological Evaluation of 4β-substituted Anilino Derivatives of3',4'-O-Didemethylpodophyllotoxin ##STR41## Inhibition of Cellular DNA Topo- Protein-DNA isomerase II Complex Cytotoxicity.sup.a Activity.sup.b FormationexampleR ID.sub.50 KB(μM) ID.sub.50 (%) 10 μM__________________________________________________________________________etoposide ##STR42## 0.20 50 10017 ##STR43## 1.7 25 12818 ##STR44## 3.0 10 11719 ##STR45## 1.6 10 10520 ##STR46## 2.3 10 11921 ##STR47## 1.9 1.0 17522 ##STR48## 1.5 10 14623 ##STR49## 1.3 10 200__________________________________________________________________________ .sup.a ID.sub.50 was the concentration of drug which affords 50% reductio in cell number after three day incubation. .sup.b Each compound was examined with three concentrations at 10, 25, 50 and 100 μM. The ID.sub.50 value was established based on the degree of inhibition at these three concentrations.
TABLE 3__________________________________________________________________________Biological Evaluation of 4β-sbustituted anilino derivatives of6.7-O-dimethylene-4'-O-demethylpodophyllotoxin ##STR50## Inhibition of DNA Topo- Cellular isomerase II Protein-DNA Cytotoxicity.sup.a Activity.sup.b ComplexexampleR.sub.1 R.sub.2 R.sub.3 ID.sub.50 KB (uM) ID.sub.50 (%) 20 μM__________________________________________________________________________Etopo- H CH.sub.2 0.20 50 100side26 ##STR51## H H >1.00 25 8427 ##STR52## H H 0.76 20 9928 ##STR53## H H 0.78 20 13829 ##STR54## H H 1.00 20 6230 ##STR55## H H >1.00 25 5231 ##STR56## H CH.sub.3 0.40 50 10832 ##STR57## H CH.sub.3 <0.40 50 12533 ##STR58## H CH.sub.3 <0.40 100 127__________________________________________________________________________ .sup.a ID.sub.50 was the concentration of drug which affords 50% reductio in cell number after three day incubation. .sup.b Each compound was examined with three concentrations at 20, 25, 50 and 100 μM. The ID.sub.50 value was established based on the degree of inhibition at these three concentrations.
TABLE 4__________________________________________________________________________Biological Evaluation of 4β-Amide Derivatives of 4'-O-Demethylpodophyllotoxin ##STR59## Inhibition of Cellular DNA Topo- Protein-DNA isomerase II Complex Cytotoxicity.sup.a Activity.sup.b FormationexampleR ID.sub.50 KB(μM) ID.sub.50 (%) 20__________________________________________________________________________etoposide ##STR60## 0.20 50 10034 ##STR61## 0.64 >50 17735 ##STR62## <1.00 50 16036 ##STR63## 0.34 25 11737 ##STR64## 0.61 25 13738 ##STR65## 1.00 50 12439 ##STR66## 1.00 50 14940 ##STR67## 0.10 25 15941 ##STR68## 0.33 10 8642 ##STR69## 0.42 25 149__________________________________________________________________________ .sup.a ID.sub.50 was the concentration of drug which affords 50% reductio in cell number after three day incubation. .sup.b Each compound was examined with three concentrations at 10, 25, 50 and 100 μM. The ID.sub.50 value was established based on the degree of inhibition at these three concentrations.
TABLE 5__________________________________________________________________________Biological Evaluation of 4β-substituted Anilino Derivatives of3',4'-Didemethoxy-3',4'-dioxo-4-desoxypodophyllotoxin ##STR70## Inhibition of Cellular DNA Topo- Protein-DNA isomerase II Complex Cytotoxicity.sup.a Activity.sup.b FormationexampleR ID.sub.50 KB(μM) ID.sub.50 (%) 20 μM__________________________________________________________________________etoposide ##STR71## 0.20 50 10043 ##STR72## >2.1 25 9244 ##STR73## 1.5 10 12845 ##STR74## 1.1 25 110__________________________________________________________________________ .sup.a ID.sub.50 was the concentration of drug which affords 50% reductio in cell number after three day incubation. .sup.b Each compound was examined with three concentrations at 10, 25, 50 and 100 μM. The ID.sub.50 value was established based on the degree of inhibition at these three concentrations. ##STR75## | Compounds which are analogs of etoposide and which exhibit anti-tumor activity are disclosed. These compounds having the following structure: ##STR1## wherein R is selected from ##STR2## wherein R 1 , R 2 , R 3 , R 4 and R 5 are each independently selected from H, CH 3 , C 2 H 5 , C 3 H 7 , i--C 3 H 7 , C 4 H 9 , CF 3 , OCH 3 , OC 2 H 5 , OC 3 H 7 , OC 4 H 9 , O--i--C 3 H 7 , O--i--C 4 H 9 , --OCH 2 O--, --OCH 2 CH 2 O--, CH 2 OH, C 2 H 4 OH, CH 2 Cl C 2 H 4 Cl, CH 2 F, C 2 H 4 F, CH 2 OCH 3 , COCH 3 , COC 2 H 5 , CO 2 CH 3 , CO 2 C 2 H 5 , NO 2 , NH 2 , NH 2 .HCl, NH 2 .HAc, NH 2 .1/2H 2 SO 4 , NH 2 .1/3H 3 PO 4 , N(CH 3 ) 2 , N(C 2 H 5 ) 2 , OH, CN, N 3 , SO 2 H, SO 2 NH 2 , SO 2 Cl, phenyl, substituted phenyl, phenoxy, substituted phenoxy, anilinyl, substituted anilinyl, cyclohexyl, piperidine, ##STR3## wherein R 6 is selected from hydrogen, methyl, ethyl, n-propyl, i-propyl, butyl and bridged methylene;
wherein R 7 is selected from ##STR4## | 2 |
BACKGROUND OF THE INVENTION
1. Field of the Invention
The present invention relates to a sock donning assist device and, more particularly, to a new and improved device which enables a handicapped or infirm individual to put on a sock, stocking, or similar foot covering with great ease.
2. Description of Related Art
In my previous U.S. Pat. No. 4,066,194, issued Jan. 3, 1978, I describe a sock donning assist device which is a great improvement over like devices of the prior art. The latter includes the following United States Pat. Nos.: 1,315,096; 2,796,207; 2,828,057; 2,919,840; 3,070,271; 3,231,160; 3,452,907; 3,604,604; 3,692,217; 3,715,065; 3,727,812; 3,806,008; 3,853,252; and 3,860,156. Known prior art also includes Italian Pat. No. 717,012 and Swiss Pat. No. 343,094.
As stated above, the devices described in my earlier U.S. Pat. No. 4,066,194, while being a great improvement over the prior art, nevertheless suffers from several deficiencies. A major deficiency of my own earlier device is that it is extremely difficult for an arm amputee to easily operate the device. Since the device was designed to assist such handicapped persons I felt a need to improve same to enable a person having only one hand to more easily employ same.
Another disadvantage of my earlier device is that the means utilized to maintain the handle and insert members in a spread condition was unduly complicated, and somewhat unstable. After using the device for some time, it became clear to me that improvement in this area was also called for.
Another general disadvantage of my earlier design related to the overall arrangement and relative angular positioning of the components, which made use thereof somewhat more difficult than should be necessary. For example, the opening to the sock should be as wide and high as possible for facilitating entry of one foot, and the sock release means should smoothly and automatically release the sock without requiring undue manipulation.
It is towards overcoming the above-noted disadvantages of my own previous design that the present invention has been advanced.
OBJECTS AND SUMMARY OF THE INVENTION
It is therefore a primary object of the present invention to provide a new and improved device for assisting an individual in the donning of a sock, stocking, or like foot covering which overcomes all of the disadvantages noted above with respect to my own previous design.
Another object of the present invention is to provide a novel and unique device for assisting an individual in donning a foot covering, such as a sock or stocking, which is particularly designed to enable use by an individual having only one hand.
A further object of the present invention is to provide a sock donning assist device which more easily releases the sock from the device than previous designs.
Another object of the present invention is to provide an improved sock donning assist device which is simple in construction, easy to operate, may be inexpensively manufactured, and is sturdier than similar devices heretofore available.
A still further object of the present invention is to provide an improved sock donning assist device which provides greater ease of foot insertion and sock installation than previous devices of a similar nature.
The foregoing and other objects are attained in accordance with one aspect of the present invention through the provision of an improved device for assisting in the donning of a foot covering, which comprises handle means, insert means extending integrally from the handle means and adapted to be placed within a foot covering for spreading same, and means operatively coupled to the handle means for selectively maintaining the insert means in one of a plurality of spaced apart positions.
More particularly, the means operatively coupled to the handle means includes first means for maintaining the insert means relatively close together, and second means for maintaining the insert means relatively wide apart. The handle means more particularly comprises a pair of laterally spaced, elongated frame members, and the means operatively coupled to the handle means comprises a control bar pivotally mounted to one of the frame members. The first and second means more particularly comprise first and second notch means formed in the control bar for selectively releasably retaining the other of the frame members therein. The handle means may further include spring means connecting the elongated frame members at one end thereof for normally urging the insert means apart to spread the foot covering positioned thereover. The first notch means is positioned adjacent the one frame member during the initial installation of the foot covering thereon, while the second notch means is positioned adjacent the free end of the control bar for maintaining the foot covering in a spread position during donning.
In accordance with other aspects of the present invention, the control bar comprises a first transversely extending portion within which the first and second means are formed, a grip portion extending integrally vertically from the first portion, and a pivot portion extending transversely from the grip portion and also being pivotally coupled to the one frame member.
The insert means may comprise a pair of foot covering insert frames, each consisting of an upper frame member and a lower frame member, which in repose extend angularly away from one another from their point of connection to the handle means, thereby providing an automatic sock engaging action. Each of the lower frame members terminate in a rearwardly positioned foot covering holding device which extends downwardly and outwardly from the respective lower frame members to maintain a wide and deep opening in a foot covering to facilitate insertion of the user's foot.
In accordance with another important aspect of the present invention, there may be further provided holder means for permitting use of the device with one hand by, for example, an arm amputee. The holder means may comprise a spring device adapted to hold the sock donning assist device on the leg of a user while the sock is being initially placed thereon. The spring device in a preferred embodiment comprises a substantially U-shaped spring member adapted to be fitted over the thigh of the user to hold the sock donning assist device by engaging the handle means.
BRIEF DESCRIPTION OF THE DRAWINGS
The foregoing and other objects, aspects, uses and advantages of the present invention will be more fully appreciated as the same becomes better understood from the following detailed description of the present invention when considered in connection with the accompanying drawings, in which:
FIG. 1 is a perspective view which illustrates a preferred embodiment of the present invention;
FIG. 2 is a rear view in elevation of the preferred embodiment illustrated in FIG. 1;
FIG. 3 is a side view of the preferred embodiment illustrated in FIGS. 1 and 2, diagramatically illustrating a sock on the device and the foot of a user;
FIGS. 4 and 5 illustrate the steps involved in utilizing the device of the present invention;
FIG. 6 is a cross-sectional view of the preferred embodiment illustrated in FIG. 2 and taken along line 6--6 thereof;
FIG. 7 is a fragmentary view illustrating the lower portion of the device of the present invention in an initial operative position;
FIG. 8 is an enlarged, side view of a portion of the preferred embodiment of the present invention which is taken along line 8--8 of FIG. 7;
FIG. 9 is a perspective view which illustrates an auxiliary holding device of the present invention;
FIG. 10 is a diagramatic illustration of how the holding device of FIG. 9 and the preferred embodiment of FIG. 1 may be utilized; and
FIG. 11 illustrates a modified control bar in accordance with an alternate embodiment of the present invention.
DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENT
Referring now to the drawings, wherein like reference numerals represent identical or corresponding parts throughout the several views, and more particularly to FIG. 1 thereof, the improved sock donning assist device is therein indicated generally by reference numeral 10.
Sock donning assist device 10 includes a handle portion indicated generally by reference numeral 12, a sock expanding and gripping portion indicated generally by reference numeral 14, and a control portion which is indicated generally by reference numeral 16.
Handle portion 12 preferably comprises a pair of wire-like side frame members 18 and 20 which are joined at their upper end by a spring-imparting end member 22. Members 18 and 20 diverge from end member 22 towards their lowermost bent portions 24 and 26, respectively.
The sock expanding and gripping portion 14 comprises a pair of upper arms 28 and 30 which respectively extend integrally from lower bent portions 24 and 26 of side frame members 18 and 20. Upper arms 28 and 30 diverge from bent portions 24 and 26, for a purpose which will become more clear hereinafter.
From the distal ends of upper arms 28 and 30 extend downwardly projecting end portions 32 and 34 respectively, from which respectively integrally extend rearward lower arms 36 and 38, respectively. Arms 36 and 38 are preferably in the same vertical plane as upper arms 28 and 30, respectively, but form somewhat of an angle therewith, taking into account the end portions 32 and 34.
In order to provide a wider opening 40 for the foot of a user, a pair of downwardly bent portions 42 and 44 may extend from the lower arms 36 and 38, respectively. From bent portions 42 and 44 extend rearwardly into terminal portions 46 and 48, respectively. While portions 46 and 48 may be respectively parallel with upper arms 28 and 30, it should be appreciated that, if desired, portions 36, 42 and 46, as well as portions 38, 44 and 48, may be made straight but at an angle with respect to upper arms 28 and 30 respectively.
At the end of terminal portions 46 and 48 are respectively formed a pair of sock holder portions 50 and 52. Each of the sock holder portions 50 and 52 comprises a downwardly and outwardly somewhat U-shaped piece of wire which also assists in imparting a wide opening 40 for the foot of a user, as will be explained more fully hereinafter.
As illustrated in greater detail in FIGS. 1, 2, 3, 6, 7 and 8, control portion 16 comprises a substantially flat control rod or bar 54 which is of a length at least as wide as the widest opening desired for the sock extending and gripping portion 14. The control bar 54 is, in a preferred form, planar and includes at the free end thereof a plurality of notches 56 formed therein which are adapted to receive and retain side frame 20. A finger grip 58 may extend upwardly from the free end of control bar 54 adjacent the position of notches 56 for facilitating manipulation by a user.
Extending upwardly from the other end of control bar 54 is a side member 60 which may be utilized as a hand grip. From the top of side member 60 transversely extends a fastening pivot member 62. The control portion 16 is pivotally coupled to side frame member 18 by providing pivot holes 66 and 68 in pivot member 62 and one end of control bar 54, respectively. The control portion 16 may be installed on side frame member 18 by providing a cut or slit 64 from aperture 66 to aperture 68 along pivot member 62, side member 60, and control bar 54.
As indicated in FIG. 6, another notch 70 may be formed in control bar 54 at a position adjacent that of side frame member 18, for a purpose which will become more clear hereinafter. Side member 60 may be selectively positioned along the length of side frame member 18 by proper positioning of a rubber washer 72 or the like.
In utilizing the device of the present invention, a user having two hands may pull the gripping portion 14 together by grasping bent portions 24 and 26 and pulling same towards one another to the position illustrated in FIG. 7. With the other hand, the sock may be pleated and placed over the sock expanding and gripping portions 14 until the rearmost portion thereof is embraced by the sock holder portions 50 and 52. The divergence of upper and lower frame members 28, 30 and 36, 38 automatically grips the front closed portion of the sock S, while the holder portions 50 and 52, in combination with bent portions 24 and 26, maintain the open end of the sock on the device and provide a wide opening 40 for insertion of the foot of the user.
The user may then release bent portions 24 and 26 and may secure the right frame member 20 within one of the notches 56, as may be selected in accordance with the size of the sock and the foot of the user. At this point, the device is essentially in the state illustrated in FIG. 1.
A user then grasps the handle portion 12 and slips his foot into the wide opening 40 until it reaches the closed end of the sock. In the position illustrated in FIG. 4, the sock S is about to be placed around the heel H by rotating the handle 12 from the position of FIG. 4 to that of FIG. 5. No force or effort is required in this manipulation, and the sock S may then be easily slid over the heel and up the ankle and thigh of the user. At the conclusion of the operation, due to the rounded edges of sock holder portions 50 and 52, the latter simply glide out of the end of the sock, leaving the latter securely and properly in place. The control bar 54 may be released at the conclusion of the operation by swinging same so that side frame member 20 is released from notch 56. This may facilitate removal of the device from the sock at the conclusion of the operation.
Referring now to FIG. 9, reference numeral 74 indicates generally an auxiliary spring member which is adapted to be positioned about the leg of one who has but one hand for using the device of the present invention, such as an arm amputee. The auxiliary spring member 74 comprises a pair of substantially parallel, U-shaped projections 76 and 78 which are adapted to grip the sides of the user's thigh, as illustrated in FIG. 10. Projections 76 and 78 are connected by a transverse member 80, and free ends 82 and 84 may be provided for adjusting the spring action of the unit for various individuals.
FIG. 10 illustrates how the auxiliary spring member 74 of FIG. 9 could be utilized by an amputee having only one hand. Such a person initially grips the lower bent portions 24 and 26 and pulls same together to the position illustrated in FIG. 7. Side frame member 20 will then automatically drop within notch 70 in control bar 54 for maintaining this position without requiring the user to hold bent portions 24 and 26.
With the auxiliary spring member 74 in position on the leg L of the user as illustrated in FIG. 10, the handle portion 12 of the device 10 is placed between spring member 74 and the upper portion of the user's thigh in such a fashion that sock expanding and gripping portion 14 faces the user. Auxiliary spring member 74 therefore simply serves as a means for holding the device 10 while a one-armed user pleats the sock over the divergent arm members of portion 14. After the sock is initially placed over sock expanding and gripping portion 14 with one hand, bar 54 may be swung out of position to release side frame member 20 from notch 70. The user may reengage side frame member 20 in a notch 56 by manipulating finger grip 58 (FIG. 6).
The user may then release the handle portion 12 from the auxiliary spring member 74, and may then manipulate the device of the present invention in the same fashion described above for installing the sock S on his foot. The auxiliary holding spring member 74 is adjustable to fit differently sized legs, and the position of control portion 16 may be vertically adjusted along side frame members 18 and 20 with the aid of rubber washer 72.
Referring now to FIG. 11, there is illustrated an alternate embodiment of the present invention which utilizes a different form of separator or control bar, which is indicated generally by reference numeral 86. Handle portion 12 and sock insert and gripping portion 14 may be substantially identical to the embodiment described hereinabove.
The control portion 86 in this embodiment is designed to include an automatic sock release feature, similar to that set forth in my earlier U.S. Pat. No. 4,066,194. More particularly, control portion 86 may include a transversely extending control rod or bar 88 which is preferably planar and includes a plurality of notches 90 positioned on the front edge thereof and adapted to receive wire rod 20 of handle portion 12. A finger grip portion 92 may extend vertically from the end of bar 88 adjacent the position of notches 90.
At the other end of bar 88 is positioned a downwardly extending side portion 96 from the lower portion of which extends a transverse member 98. The end of bar 88 and transverse portion 98 are both pivotally mounted to wire frame member 18 of handle portion 12. A slit 104 may be provided to facilitate insertion onto the wire member 18.
Extending downwardly from transverse portion 98 is leg 100 which is substantially parallel with rod 18. Leg 100 extends to a position just below bent portion 24. Extending laterally from leg 100 is a sock gripping member 102 which functions in addition to sock holding portions 50 and 52 to hold the sock S prior to donning.
A notch 94 may be positioned on bar 88, in a position and for a function similar to that of notch 70 with respect to the first embodiment described above.
In operation, the sock S is initially placed over the insert portion 14 and around the holder portions 50, 52 and 102. After the sock S has been fully positioned on the leg of the user, substantially as described hereinabove with respect to the first embodiment, the control rod 88 is pivoted about rod 18 in the direction indicated by arrow 106. This pivotal movement rotates member 102 to the position indicated in dotted outline by reference numeral 108, which is in a direction parallel to the sock retaining members 14. This serves to automatically release the sock S from the device 10 of the present invention, in a manner analogous to that described in my earlier patent.
Obviously, 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 practiced otherwise than as specifically described herein. | An improved device for assisting one in the donning of a sock, stocking, or like foot covering. The device comprises a handle member from which laterally and transversely depend a pair of sock expanding and holding members which are adapted to be placed within a sock to spread same for permitting easy entry of the foot of a user. An improved control bar extends between the wire-like handle members and permits the spacing between same to be adjustable to any of a plurality of distances, correspondingly varying the distance between the sock engaging members. An auxiliary holding member may be provided for facilitating use of the device by an amputee. | 0 |
BACKGROUND OF THE INVENTION
The present invention relates to a semiconductor component with adiabatic transport in edge channels and relates in particular to a semiconductor radiation detector, above all for the detection of electromagnetic radiations in the far infrared region.
For the detection and observation of electromagnetic radiations in the region of the far infrared (50 μm to 1000 μm) two types of detectors are known in the prior art. The first type includes Si and Ge bolometers in which the detection mechanism relates to non-resonant thermal absorption at low temperatures T of approximately 1.6K. Such bolometers have a time constant, i.e. a time resolution of approximately 1 ms and an NEP (noise equivalent power) of approximately 10 -14 Watt/√Hz. Special bolometers of this kind are obtainable from the company Infrared Laboratories, Inc., Tucson, Ariz., USA.
The second type of far infrared detectors are pyroelectric detectors in which the detection method relates to a non-resonant heating of a pyroelectric crystal at room temperature. Here the time constant is approximately 0.2 ms and the NEP is about 8×10 -10 Watt√Hz. Such detectors are available commercially, for example in the form of the model 404 from Eltec Instruments S.A., Zurich, Switzerland.
The most serious disadvantages of Si and Ge bolometers lie in the lack of tunability which originates from the non-resonant thermal absorption and the time constants which are large for the same reason. The value of 1 ms does not permit any temporally highly resolved spectroscopy. For the physical detection of far infrared radiations very much shorter time constants are desirable. Bolometers are furthermore not integratable onto a chip as a result of their size and the principle of construction that is used. The mechanical stability of bolometer designs also leaves something to be desired.
In analogy to bolometers pyroelectric detectors are also relatively ill-suited for spectroscopic purposes because they cannot be tuned through a range of frequencies.
The material involved in the principle of design of pyroelectric detectors also does not permit integration with an electronic evaluation circuit on a chip. The detector only reacts to changing radiation intensity and can thus only be operated with modulation.
The object of the present invention is thus to provide a novel radiation detector which is in particular suited for the far infrared region, but can also be used for shorter and longer wavelengths, and which can be realized by semiconductor technology so that integration onto a chip is possible, for example together with the requisite electronic evaluation circuit. Furthermore, the detector should have a higher NEP and a shorter time constant in comparison to the known detectors and it should preferably also be tunable through a range of wavelengths and/or so designed that radiations of different wavelengths can be detected with one detector unit.
SUMMARY OF THE INVENTION
In order to satisfy this object by means of a semiconductor component with adiabatic transport in edge channels the solution of the invention is characterized by the use of the semiconductor component as a semiconductor radiation detector in which the adiabatic transport is disturbed by interaction with the electromagnetic radiation to be detected, i.e. an increase of the scattering rate between the edge channels is caused, that is to say an increase of the inter edge channel scattering, and by a means for detecting this disturbance or increase through detection of the change of resistance which occurs.
More precisely stated the present invention relates to a semiconductor radiation detector with layer-wise construction and a conductive region having a two-dimensional or quasi one-dimensional electron or hole gas in which an adiabatic transport takes place at least originally in edge channels (also termed edge states) and also with at least two contacts to this conductive region, with the transport in the edge channels being disturbed by interaction with the electromagnetic radiation to be detected, i.e. with an increase of the scattering rate between the edge channels being caused, which leads to a change of the resistance measurable between the contacts which can be detected with known measurement methods.
Adiabatic transport in two-dimensional electron gases (2DEG) and the occurring change of resistance during the transition to so-called equilibrated transport is known per se and is for example described in the article "Edge channels and the role of contacts in the quantum Hall-regime" in Physical Review B, Vol. 42, No. 12 of Oct. 15, 1990 by G. Muller, D. Weiss, S. Koch and K. von Klitzing and also by H. Nickel, W. Schlapp and R. Losch. There the change of resistance is realized by the application of suitable potentials to the gate electrodes that are provided which leads to a change of the filling factors and thus the number of the occupied edge channels (edge states) beneath the gate electrodes, and indeed independently of the filling factor in the material not influenced by the gate.
As can be read in the said article the Landauer-Buttiker model has been successfully applied in recent time in connection with the quantum Hall effect in order to describe the quantized resistance values which arise. Within this picture the transport in strong magnetic fields and at low temperatures is governed by one-dimensional channels at the boundaries of the two-dimensional electron gas (2DEG). These channels are formed by the intersection of the Fermi energy with the bent-up (due to confining potential) Landau-levels at the edges of the device. Classically considered these edge states correspond to skipping orbits moving along the edges in opposite directions on opposite sides of the sample. The number of the occupied edge channels is given by the filling factor in the 2DEG. A net current I flows due to a difference in the electrochemical potential Δμ between two sides of the Hall structure (Hall bar). Backscattering from one side of the sample to the other is the reason for dissipation and therefore finite resistance in this model.
The electrochemical potential of the edge channels is determined by the contacts, the current, the magnetic field and the gate electrodes. If all available edge channels are occupied up to the same electrochemical potential (on one side of the sample) with each channel carrying the same current then one speaks of equilibrated transport. In contrast the transport with a dissimilar distribution of the current between the edge channels is termed adiabatic transport, The measured resistance changes depend on whether the transport is adiabatic or equilibrated, The measurement of this resistance can for example be effected as a customary 4-point-resistance measurement as can be read in the cited article, A 2-point--resistance measurement is also possible.
For the sake of brevity the content of the named article will not be described further here, The content of the article is however incorporated by this reference into this application.
The starting point for the present invention is thus the concept of adiabatic transport (absence of scattering between the selectively occupied one-dimensional edge channels in high mobility two-dimensional electron and hole gases), The invention is thus based on the special recognition that the absorption of photons (photon energy approximately the same as the cyclation resonance energy) in a semiconductor component of this kind leads to a coupling of the selectively occupied edge channels, i.e. to a transition from adiabatic to equilibrium transport which brings about a pronounced change of the resistance which can be evaluated as an indication of the detection of the incident radiation. The conditions for an adiabatic transport at low temperatures can for example be realized by means of Schottky gates.
The inventive concept described here has already been successfully tested with AlGaAs/GaAs heterostructures and it has been shown that far infrared detection is possible with the radiation detector in accordance with the invention. The time constant of the measurements carried out with the radiation detector of the invention is at least a factor 1000 smaller than the time constant of known Si and Ge bolometers so that temporally highly resolved spectroscopy is possible with the radiation detector of the invention. The sensitivity is at least an order of magnitude better than the sensitivity of pyroelectric detectors so that detectors in accordance with the invention are best suited for far infrared astronomy, far infrared solid state spectroscopy, far infrared molecular spectroscopy and time resolved far infrared spectroscopy. Application possibilities for spatially resolved far infrared detection are also in sight. Furthermore, a radiation detector in accordance with the invention is absolutely predestined for integration onto a chip (electronic evaluation circuit and detector on one GaAs chip).
Although the operation of the detector of the invention would be conceivable without an applied magnetic field (with lateral constriction of the channels, which will be explained later), a particularly preferred practical embodiment is characterized by a means for generating a magnetic field which has at least one component and which can be applied perpendicular to the electron or hole gas, i.e. to the layers of the semiconductor component. In the non-irradiated state of the detector the magnetic field namely brings about a reduction of the scattering between the edge channels so that the resulting change and resistance at the transition into the irradiated state becomes even higher. On using the semiconductor radiation detector for the detection of a radiation of a given wavelength the strength of the said component of the magnetic field lies in the range up to approximately 15 Tesla, in particular at approximately 3 Tesla.
Through change of the strength of the said component of the magnetic field the frequency sensitivity of the radiation detector is displaced. In other words the semiconductor radiation detector in accordance with the invention can be tuned. A special embodiment of such a radiation detector is thus characterized in that a means is provided for changing the strength of the magnetic field or of the said components of the latter.
The means for generating the magnetic field is preferably a coil, with the conductive region of the detector preferably lying transverse to the axis of the coil in the immediate vicinity of the coil and thus within homogenous magnetic field. The coil is preferably a superconducting coil.
The semiconductor detector of the invention must namely be operated at low temperatures, for example at a temperature of approximately 4° K, preferably of approximately 1.3° K, so that the operating temperature is already so low that superconducting materials can be used without additional complexity of note. Such superconducting coils have moreover the advantage that the thermal dissipation is essentially zero, so that the cryostat which is necessary for these low temperatures is not unnecessarily burdened. The current in the superconducting coil can be induced once on starting the operation of the detector and can then remain in the coil until the measurements have been completed.
In the simplest embodiment the semiconductor radiation detector of the present invention is characterized in that the said contacts are formed by first and second contacts which are provided with a spacing from one another at respective ends of the conductive region, with at least one gate electrode being provided which is arranged between the first and the second contacts and covers over a part of the length of the conductive region.
The contacts serve for carrying out the required resistance measurement, while the gate electrode determines the filling factor in the underlying part of the conductive region. Even better is an arrangement in which a second gate electrode is provided which is arranged at a distance from the first gate electrode and likewise covers over the conductive region over a further part of its length, with the adiabatic transport being realized between the gates.
It is of advantage when at least one further gate electrode and preferably several gate electrodes are arranged at regular intervals over the length of a conductive region and preferably all have the same potential, for example in that they are connected together. Through the plurality of gate electrodes the resulting change in resistance and thus also the sensitivity of the detector is increased.
It is in particular preferable when the gate electrodes form a periodically applied gate structure which then serves as a grid coupler and brings about a pronounced change in resistance through magnetoplasmon coupling of the edge channels.
Through the application of a predeterminable potential to an additional gate electrode provided on the rear side of the sample the detector can also be tuned through the envisaged frequency range. This thus represents an alternative to achieving tunability through changing of the magnetic field. It can however also be useful to change both the gate potential and also the strength of the magnetic field.
Although only two ohmic, i.e. non-ordered, contacts are ultimately sufficient in order to measure the resistance of the conductive region two further contacts are preferably provided, whereby a known 4-point-measurement of the resistance of the conductive region can be carried out. In this way the accuracy of the measurement is increased.
A plurality of detectors in accordance with the invention can with advantage be built up on one chip. In this way it is, for example, possible to provide a certain redundancy so that on failure of the one detector a switch can be made to a further detector by means of a suitable circuit.
It is particularly favorable when a plurality of detectors are formed on one chip and individual detectors are laid out to detect radiation of different wavelengths. This can for example be achieved by the use of gate structures with different dimensions or periodicity through magnetoplasmon coupling, and/or by applying different gate potentials and/or by applying different magnetic fields and/or by the use of non-homogeneous magnetic fields.
As already indicated provision is made in accordance with the invention that the means for carrying out the resistance measurement and for the applying of control potentials to the chip are integrated onto the chip.
The coil for generating the magnetic field can likewise be integrated onto the chip, preferably in the form of a superconducting loop. A window which permits access of the radiation to the conductive region is also important.
Although the radiation detector of the invention can be realized with all semiconductor systems in which a two-dimensional electron or hole gas or a quasi one-dimensional electron or hole gas can be realized, i.e. in all known II-VI, III-V or IV-VI compositional semiconductors or in silicon or germanium semiconductors, preference is given in accordance with the invention to the GaAs/Al x Ga 1-x As compositional semiconductor system. A semiconductor radiation detector in accordance with this system is characterized by the following layer build-up:
a buffer layer arrangement and an intrisic GaAs layer with a thickness in the μm-range are first grown on a GaAs substrate by epitaxy, preferably by molecular beam epitaxy,
an undoped Al x Ga 1-x As-spacer with a layer thickness in the 100Å-range is grown onto the intrisic undoped GaAs layer,
followed by a further layer of the same material but with an impurity doping having a three-dimensional concentration of preferably 2-7×10 18 cm -3 , preferably in the form of a homogeneous doping or in the form of a delta doping (for example in accordance with U.S. Pat. No. 4,882,609),
wherein a cover layer of undoped GaAs is grown onto this doped layer, and
wherein the contacts to the 2DEG and also the gate electrodes are produced following photolithographic delimitation of the conductive region, in which the undesired regions are removed to a level beneath the two-dimensional electron gas which forms in the boundary region between the undoped GaAs layer and the Al x Ga 1-x As-spacer.
BRIEF DESCRIPTION OF THE DRAWINGS
FIG. 1 is a schematic illustration of the layer build-up of a semiconductor radiation detector in accordance with the invention,
FIG. 2 is a plan view of the radiation detector of FIG. 1 after completed etching and application of the contacts and gate electrodes,
FIG. 3 is a schematic illustration similar to that of FIG. 2 but of a modified embodiment of a radiation detector in accordance with the invention,
FIG. 4 is a further representation similar to FIGS. 2 and 3, but of a further inventive embodiment of the radiation detector,
FIG. 5 is a schematic illustration of two radiation detectors in accordance with the invention integrated onto a chip,
FIG. 6 is a schematic illustration similar to the FIG. 2 of a radiation detector in accordance with the invention which is laid out for the carrying out of a Hall resistance measurement,
FIG. 7 is a further illustration of a radiation detector in accordance with the invention similar to the detector of FIG. 2 but for carrying out a 2-point-resistance measurement,
FIG. 8 is a schematic illustration of the radiation detector of FIG. 5 in accordance with the invention but built into a cryostat,
FIG. 9 is a further embodiment of an inventive radiation detector with a single gate electrode,
FIG. 10 is a modified embodiment of the radiation detector of FIG. 9,
FIG. 11 is a further embodiment of a radiation detector in accordance with the invention with four contacts but with no gate electrode,
FIG. 12 is a modified embodiment of the radiation detector of the invention of FIG. 11 but with a single gate electrode,
FIG. 13 is a graph to prove the existence of adiabatic transport in a semiconductor radiation detector in accordance with the invention,
FIG. 14 is a graph to show the sensitivity of a semiconductor radiation detector in accordance with the invention,
FIG. 15 is the induced change of resistance of a semiconductor radiation detector in accordance with the invention as a function of the measurement current, this curve shows how the maximum of the resistance curve b) of FIG. 14 depends on the measurement current and,
FIG. 16 is the plot of the measured resistance a) when irradiation by photons, b) in the non-irradiated state.
DESCRIPTION OF THE PREFERRED EMBODIMENTS
FIG. 1 firstly shows the layer build-up of a semiconductor radiation detector 2 in accordance with the invention. As shown there a buffer layer arrangement 12 is first build-up by means of MBE on an insulated GaAs substrate 10 in order to provide a clean crystal structure and to prevent any impurities in the substrate from creeping into the active region of the semiconductor. Such buffer layer arrangements are well known, and are thus not be explained here in further detail. A further layer 14 of undoped gallium arsenid is deposited on the buffer layer arrangement 12 and has a layer thickness of approximately 2 μm. This layer 14 is followed by a spacer layer 16 comprising a nondoped Al 0 .25 Ga 0 .75 As spacer with a layer thickness of approximately 200Å. On this spacer layer a further layer of the same composition is then likewise deposited by MBE, i.e. a layer of Al 0 .25 Ga 0 .75 As with the layer thickness of for example 400 Å. This layer 18 is however a doped layer the task of which is to make available charge carriers in the form of electrons for the GaAs layer 14, so that these electrons form a two-dimensional electron gas adjoining the transition to the spacer layer 16. For this purpose the layer 18 is a doped layer and can for example be an homogeneously doped layer, or a Dirac-Delta doped layer such as is for example described in U.S. Pat. No. 4,882,609. In both cases the surface concentration of the impurity atoms (silicon) is approximately≈2.10 13 cm -2 . A terminal layer of undoped GaAs is then present on the layer 18.
After growing the different layers by MBE the chip is etched by means of a photolithographic process known per se in order to generate a semiconductor component with the topography for example of FIG. 2. The etching process is carried out in such a way that the chip is etched away down to the level 22, i.e. to a level beneath the 2DEG. The etched surface is illustrated with hatched lines in FIG. 2 (and also in the further FIGS. 3 to 8). There thus remains a bar 24 with two downwardly projecting transverse limbs 26 and 28, with the bar 24 projecting to the right and to the left beyond the limbs 28 and 26. As the two-dimensional electron gas extends beyond bar 24 into the limbs 26 and 28 a conductive connection exists between these regions.
Next of all first and second contacts 30 and 32 are provided to the respective ends of the bar and third and fourth contacts 34, 36 are provided to the respective free ends of the limbs 26, 28. Moreover two gate electrodes 38 and 40 are provided which are arranged spaced apart from one another above the central region of the bar 24. The four contacts 30, 32, 34, 36 are ohmic contacts of metal (AuGe/Ni) to the 2DEG. The two gates 38, 40 are in contrast Schottky gates which respectively consist of a 20 Å thick layer of a NiCr alloy and a 1000 Å thick layer of gold.
The ohmic contacts are defused into the crystal during a thermal treatment. The NiCr/Au Schottky gates are subsequently vapor-deposited onto the crystal.
The spacing d between the gate electrodes 38, 40 can be substantially shorter than the wavelength q to be detected, from which it can be seen how small the dimensions of the component itself can be. In the illustrated embodiment, d amounted to 50 μm. The electron concentration in the 2DEG amounted to 2.71×10 11 /cm 2 and the mobility was measured at 560,000 cm 2 /Vs.
In operation the semiconductor component in accordance with FIGS. 1 and 2 is placed in a cryostat at a temperature of preferably 1.3° K and a 4-point-resistance measurement is effected via the contacts 30, 32, 34 and 36, and indeed preferably in a magnetic field which penetrates in the direction of the arrow 42 of FIG. 1 through the conductive region of the bar 24., i.e. a magnetic field which lies perpendicular to the plane of FIG. 2.
When the strength of the magnetic field is matched in accordance with the cyclotron resonance conditions to the wavelength to be detected then a pronounced change of resistance is determined between the non-irradiated state of the semiconductor radiation detector (low resistance) and the irradiated state (increased resistance). Instead of operating with a predetermined magnetic field strength one can change the strength of the magnetic field, for example in the region up to approximately 15 Tesla, whereby the detector becomes tunable, i.e. can be tuned to different frequencies. It is necessary to apply special potentials to the gate electrodes 38, 40. The application of such potentials makes it possible to change the number of occupied edge states (edge channels) beneath the gate electrodes which in accordance with the theory has effects on the measured resistance. The use of such control potentials also makes it possible to set the resistance values in the desired regions and above all enables a pronounced change of resistance between the irradiated and the non-irradiated states.
As set forth in the named article in the Physical Review B, volume 42, No. 12 of Oct. 15, 1990 the 4-point-resistance in the non-irradiated state comprises: ##EQU1## with ν g being the filling factor beneath the Schottky gate electrodes and ν b the filling factor in the bar region beneath the gate electrodes, i.e. in the non-gated region. The designations R, h and e have the usual meaning. Furthermore ν is given by the following equation:
ν=hN.sub.s /eB (B)
with B being the strength of the magnetic field perpendicular to the 2DEG and N s being the electron density. The above quoted equation for the resistance applies as long as the transport is completely adiabatic. For a change of this transport into equilibrated transport, i.e. in the non-radiated state of the semiconductor radiation detector the following equation then applies: ##EQU2## (when the number of gate electrodes is 2).
FIG. 3 shows that the invention is in no way restricted to only two gate electrodes. Accordingly three gate electrodes are used in FIG. 3 which are all manufactured with a common connection electrode so that all gate electrodes have the same potential. This is however not necessary. The gate electrodes could be provided with different potentials which would be possible by the omission of the connection electrode.
FIG. 4 shows an alternative embodiment, with four gate electrodes 38, 40, 44 and 48 which are in turn connected electrically to one another, in this example via a connection electrode 46.
FIG. 5 shows an example with two semiconductor radiation detectors in accordance with the invention which are formed on a common chip 1. Here the detector 2 is formed in accordance with the detector of FIG. 2 with the distinction that in this case a common connection electrode 46 is provided between the two gate electrodes 38 and 40. The second semiconductor radiation detector 3 is formed approximately in accordance with the radiation detectors of FIGS. 3 and 4 but with five gate electrodes 38, 40, 44, 48 and 50. The number of gate electrodes can be substantially higher than five without restriction. These gate electrodes are connected together by a common electrode 46.
One notes that the two radiation detectors 2 and 3 have a common limb 28, i.e. it is not necessary to provide a separate limb 28 for each detector. It is likewise not necessary to provide first and second contacts for each detector, but rather first and second contacts 30 and 32 can be common to the two detectors, as shown here. For the measurement of the 4-point resistance for the detector 2 the contacts 30, 32, 34 and 36 are thus used in the embodiment of FIG. 5. For the measurement of the 4-point-resistance the contacts 30, 32, 36 and 52 are used for the detector 3.
FIG. 5 shows a further special feature. The gate electrodes 38, 40, 44, 48, 50 with a common connection electrode 46 form a periodic gate structure which leads, under the influence of the magnetic field that is used, to an excitation by the radiation to be detected of magnetoplasmons which are formed in the structure. A more pronounced change of resistance is caused by the coupling of the edge states via magnetoplasmons, so that the sensitivity of the measurement is increased.
An alternative measurement is possible with the arrangement of FIG. 6 in which the semiconductor radiation detector is laid out so as to carry out a measurement of the Hall resistance in accordance with the proposal in the named article in Physical Review B, vol. 42, No. 12 of Oct. 15, 1990. Here two further gate electrodes 54 and 56 are provided in addition to the gate electrodes 38 and 40 of FIG. 2, are likewise formed as Schottky electrodes and are arranged on respective limbs 58, 60 of a transverse bar 62, with the two-dimensional electron gas extending from the bar 24 into the limbs 58, 60 of the transverse bar 62. Two further contacts 64 and 66 are provided at the free ends of the respective limbs and serve during the resistance measurement as Hall sensors. The further gate electrodes 54 and 56 serve to electrically couple in or decouple the Hall sensor contacts 64, 66.
A less precise, but also less complex solution for the measurement of the resistance of the conductive region 24 is shown in FIG. 7. The semiconductor radiation detector of FIG. 7 namely has two contacts 30 and 32 which are arranged at respective ends of the bar 24. In this case two gate electrodes 38 and 40 are provided; this does not however represent a restriction. Thus, only one gate electrode can be provided or alternatively a plurality of gate electrodes can also be connected together in accordance with FIG. 5 to form a periodic gate structure. It is important that a free part of the conductive region is present, i.e. a part of this region which is not covered by a gate electrode.
FIG. 8 shows schematically the building of the semiconductor detector of FIG. 5 into a cryostat. The chip 1 is mounted on a stable holder 70 beneath a window 72 which transmits the radiation to be detected to the semiconductor radiation detector. When the detector is carried by a satellite or by a space vehicle then a cryostat is no longer necessary since the operating temperature in space lies at approximately 1° K.
The chip 1 is arranged within, or directly beneath, a coil 74 in the form of a closed loop which consists of a material which is superconducting at the operating temperature of the cryostat. In order to induce a current into this superconducting loop a conductor 76 extends perpendicular to the plane of the loop within the latter. The conductor 76 is connected via two feed lines 78 and 80 to an electronic system 82 which is supplied via the line 84 with current from a power supply 86. The conductor 76 in connection with the electronic control 82 is able to induce a current into the superconducting loop 74 and also to vary it in known manner. In this way the magnetic field B perpendicular to the plane of the loop 74, i.e. perpendicular to the surface of the chip 1, can be varied in order to tune the detector.
The contact electrodes and the gate electrodes of the detectors 2 and 3 are likewise connected via lines to the electronic system 82 which applies the necessary control potentials and carries out the resistance measurements. The results of the resistance of the measurement are received by a computer 90 via the line 88 which can further process the resistance values. The results of the processing by the computer are shown on the image screen 92 and can, if necessary, be printed out and stored.
At this point certain special variants of the subject of the application should be explained in more detail. It has already been mentioned that it is in principle possible to operate far infrared detectors in accordance with the invention in the adiabatic transport regime even without a magnetic field. A precondition for this is that the lateral width of the two-dimensional system (of the etched mesa bar or ridge) is so small that the two-dimensional system becomes a quasi one-dimensional system. For this case the one-dimensional sub-bands take over the function of the Landau levels. Instead of the spacing of the Landau levels (which is the same as the cyclotron energy) the energetic spacing of the one-dimensional sub--bands is determined solely by the now very pronounced lateral constriction of the system. The principal geometry with two gates, for example in accordance with FIG. 2, can be retained. Instead of the far infrared resonance at the cyclotron energy one would now observe a resonance at very low frequencies, the energetic position of which is determined by the lateral constriction of the original two-dimensional system.
One can realize excellent far infrared detectors in accordance with the invention with only one gate. For this there are two special possibilities. The first possibility is shown in FIG. 9.
The embodiment of FIG. 9 is very similar to that of FIG. 7, however only a single gate electrode 38 is provided which is preferably centrally arranged and which is formed as a semi-transparent gate. This gate lies above the strip-like mesa ridge with parallel side edges and is formed as a Schottky gate. The reference numerals 30 and 32 here signify ohmic contacts which are necessary to carry out a 2-point-resistance measurement. The arrangement could however also be executed in accordance with FIG. 2 with further contacts 34, 36 for the purpose of carrying out a 4-point-resistance measurement. Semi-transparent gate electrodes are known and are achieved by using thin gate layers.
In this example a filling factor of 2 is achieved in the ungated region, whereas the filling factor in the gated region is 4, which is achieved by the application of a positive potential to the gate.
As with other structures a coupling in of the two (under the gate) orbiting edge states to the two transmitted edge states is possible. Without coupling one has adiabatic transport and with coupling equilibrated transport. The transition from adiabatic to equilibrated transport again results in a change of resistance.
The second possibility is shown in FIG. 10 and is similar to the embodiment of FIG. 9, at least in its basic concept. Stated more precisely the embodiment of FIG. 9 is modified in the following way and manner. First of all a hole, preferably a rectangular hole 100, is etched into the two-dimensional system, i.e. into the bar 24. In addition to the contacts 30 and 32 a third contact 34 is provided which is placed centrally in the bar 24 and realizes a contact to the 2DEG. One gate electrode 38 is then placed over the central region of the conductive bar 24 and has a cut-out, for example in the form of a keyhole 102, so that the third contact lies within the square part of the keyhole 102. A free space around the third contact 34 should now be present within the keyhole. The precise shape of the cut-out is not critical; it could also have a square shape. One notes that the etched away rectangle 100 extends from the third contact 34 beneath the gate electrode 38.
The current I flows between the contacts 30, 32 while a potential U 34, 32 is applied between the third contact 34 and the second contact 32. A filling factor 4 arises in the non-gated region and a filling factor 2 beneath the gated region.
As in FIG. 9 the incident far infrared radiation at the cyclotron energy also leads from the transition from adiabatic transport to equilibrated transport. This again results in a resistance change of 30, 32; 34, 32. The formulae named in this application do not apply for this geometry, however analog formulae can be derived. Both the embodiment of FIG. 9 and also the embodiment of FIG. 10 are intended for the operation with a magnetic field applied perpendicular to the plane of the drawing.
In addition to the previously presented methods with one or more gates there is also a possibility which is very interesting for the envisaged applications of using a structure without any form of gate. An example of this kind is shown in FIG. 11 and is very similar to the example of FIG. 3, however the gate structure 38, 44, 40 and 46 is omitted.
One is concerned here with a high mobility 2DEG. A measurement is made of R 30 ,32;34,36 - as in other structures. A structure of this kind is very sensitive to cyclotron resonance photons in the following filling factor regions and thus also magnetic field regions:
7>ν>6
5>ν>4
3>ν>2
Within these three frequency windows the detector is again also tunable via the magnetic field. The physical process involved here is again a transition between adiabatic and equilibrated transport. This identification of the physical process results from the same current and temperature dependence of the resistance R 30 ,32;34,36 in these three magnetic field windows analogous to the adiabatic transport described in reference [11].
The disadvantage of this detector, namely that only three windows are present here which do not overlap, so that the detector cannot be continuously tuned with the magnetic field, can be avoided if one applies an additional gate electrode. This additional gate electrode has the function of changing the carrier density. By changing the carrier density the three filling factor windows at which the detector is sensitive are shifted to higher or lower magnetic fields depending on the sign of the applied potential. In this way one can also achieve continuous tunability, i.e. tunability throughout a continuous frequency range. It is possible to understand why one can observe adiabatic transport also with ungated samples if one assumes that intrinsic barriers are present in the semiconductor material which now take over the function of the gate fingers. There are also two possibilities of realizing this structure with an additional gate electrode. The first possibility is shown in FIG. 12 in which the structure of FIG. 11 is provided with a semi-transparent top gate 38 which not only covers the central region of the conducting strip 24 but also partly covers the two limbs 26 and 28.
One can however also operate with a second possibility, namely with a so-called "Backgate". For this purpose one must grind down the sample structure of FIG. 11 to a thickness of ca. 150 μm in the growth direction. This structure is then bonded, for example with a conductive silver adhesive onto a gold layer. This gold layer then serves as an electrode at the backside. Through the application of a gate potential between this backside electrode and the 2DEG one can then change the carrier density of the 2DEG.
For the sake of completeness the physical background will now be explained in more detail with reference to experiments which have been carried out with the semiconductor radiation detectors of the invention, and also with reference to FIGS. 13 to 16, which also gives details of scientific publications which serve for a better understanding of the invention.
Two-dimensional electron gases in high mobility AlGaAs/GaAs heterostructures are of interest for far infrared photoconductors because the photoresponse behavior in strong magnetic fields is determined by the sharp (Δ<1cm -1 ) and tunable cyclotron resonance (hω c αB).
In contrast to earlier work on photoconductivity in GaAs/A1GaAs heterostructures [1,2,3,4] measurement results will be presented in the following for a novel concept of cyclotron resonance (CR) photoconductivity which makes use of the electron density discontinuities which are induced by metallic front gates on the sample. The basic idea follows from the edge channel model [5,6] of the Quantum Hall effect which, in this transport regime, is used [7] for the interpretation of the results on these investigated samples. The aim of this explanation is to show that the sensitivity of these new photoconductors can be increased by more than an order of magnitude in comparison to homogeneous samples. In addition the evaluation of the experimental results within the framework of the edge channel model leads to new insights into the electronic processes which lead to photoconduction.
Within the Landauer-Buttiker-description [5,6] of the Quantum Hall effect the current is-carried via one-dimensional currents located at the boundary of the sample, as schematically illustrated in FIG. 2 by the reference numeral 28. The number of these edge channels is given by the filling factor. The direction of the current flow is determined by the direction of the magnetic field, so that currents on opposite sides flow in opposite directions. The net current through the sample is established by the difference of the currents at these opposite edges. Ideal ohmic contacts acting as metallic election reservoirs with the electrochemical potentials μ j feed the edge channels on one edge equally up to μ j [8]. The edge channels flowing out of this contact carry the current [8]. ##EQU3## where N is the number of the edge channels. The transport regime, where strong inter edge channel scattering leads to the same μ j of adjacent edge channels, is denoted as equilibrated. In contrast adiabatic transport is characterized by the absence of inter edge channel scattering maintaining an unequal current distribution among the channels.
In the radiation detector described here, e.g. in accordance with FIGS. 1 and 2 adiabatic transport can be realized by a selective population of the edge channels by the means of Schottky gates. The electron density underneath the gates can be adjusted in such a way that the upper edge channels are reflected at the gate boundaries. In FIG. 2 this situation is sketched for filling factor ν b =4 in the ungated region and ν g =2 underneath the gates 38 and 40 (spin is neglected). Under this condition the current in the region between the gates is only carried by the lower edge channel (spin degenerate). Then in the absence of inter edge channel scattering the upper edge channel between the two gates is decoupled from the lower one. This means that the ν j of the upper channel on opposite sides of the sample are equal. Therefore, it carries no current. An equilibration (scattering) process between the lower and the upper edge channel leads to a difference in ν j within the upper channel on the opposite edges. This is reflected in an enlarged longitudinal magnetoresistance. The basic idea of the present proposal is that FIR cyclotron resonance photons should couple the lower to the upper edge channel and increase the magnetoresistance from the adiabatic to the equilibrated value. For integer filling factors in the ungated and the gated regions, respectively one calculates the adiabatic four-terminal resistance of the geometry in FIG. 2 by the equation A: ##EQU4##
In this notation the current is applied between the contacts 30 and 32, whereas the voltage drop is measured between the contacts 34 and 36.
Measurement results for R (in kiloohms) as a function of the gate electrode potential V g in volts are shown in FIG. 13 (without irradiation by photons, current as parameter).
The same result applies for R ad 30 ,32;34,36 of the four gate electrode finger structure of FIG. 4.
The resistance of the equilibrated transport is given by ##EQU5##
Here N is the number of the fingers of the gate structure. From these two formulae it is clearly evident that one should expect an amplified photoresponse due to a larger N. Therefore samples were prepared with two and four gate fingers in accordance with FIGS. 2 and 4.
The basic material of the semiconductor components are, as explained with reference to FIG. 1, molecular beam epitaxy (MBE) grown AlGaAs/GaAs heterostructures with an electron density of n 3 =1.8-2.7.10 11 /cm 2 and a mobility of μ=0.6-1.2.10 6 Vs/cm 2 .
1000 Å thick NiCr/Au films as Schottky gates are evaporated on top of the etched Hall bar geometry to tune the electron density underneath. The samples were immersed in liquid helium and kept at a temperature of 1.3K. The magnetic field perpendicular to the samples is provided by a superconducting magnet. Parallel to the magnetic field the FIR beam of an optically pumped molecular gas laser is guided to the samples through lightpipes. For the measurements use was made of the λ=211,232,287,311, and 392 μm laser lines. The intensities at the output of the lightpipes are in the range from 10μW/cm 2 to 100μW/cm 2 . Above the samples a cold filter stops the blackbody radiation from the top of the cryostat. The photoconductivity measurements under FIR illumination were performed in AC technique. For this, the laser was chopped with 830 Hz while the current is modulated with 13 Hz. This additional lockin step (discrimination process) eliminates photovoltaic signals, which have been discussed in a recent paper
The first step for the experimental realization of the presented concepts is to verify whether the transport is adiabatic. This has been done by resistance measurements according to (A) and (E) for integer filling factors ν b ,ν g . In the experimental parameter range the results indicate nearly adiabatic transport. The same conclusion is drawn for noninteger ν b ,ν g . Here, the sum of the resistances R 30 ,32;34,36 with only gate 38 operating and R 30 ,32;34,36 with only gate 40 operating exceed the value for the case, where a gate voltage is applied simultaneously to both gates. This is consistent with the behavior at integer ν b ,ν g in accordance with (A) and (E), and is thus also a proof of adiabatic transport.
The striking performance of the photoconductor and the proof for the concept described above are demonstrated in FIG. 14. Here, photoconductivity spectra ΔR 30 ,32;34,36 for the two gate finger part of FIG. 2 are shown under three conditions. The spectacular amplification by more than one order of magnitude of the photoconductivity signal is evident by comparing the traces a and b. The first shows the signal, when no voltage is applied to the gates. For this homogeneous electron density in the 2DEG one observes a weak negative signal, which corresponds to a resonant CR heating. This conclusion is supported by measurements of the temperature dependence of the magnetoresistance in this magnetic field range. Trace b exhibits a strong positive signal for the case, that the gate voltage V g is applied to both gates as expected from our model. Similar amplification factors have been observed on different samples and laser lines as well.
The proof of the concept of the invention is demonstrated by the comparison of the signals, when the gate voltage is applied only to one gate and to two gates. If the voltage is applied only to one gate, there exist no decoupled topmost edge channel between the gates and we deal with equilibrated transport. Hence, an amplified photoresponse is not expected. This is confirmed by trace c, where the gate voltage is applied only to gate 38. The curve for gate 40 is identical and therefore omitted. The CR peak of b rises and is distinguished substantially from the peak of trace c. It is concluded that in the two gate case the CR photons raise the inter edge channel scattering rate monitored by the increase of the resistance.
Further support for the photoconductivity concept in the adiabatic transport regime is evident, if we apply the analysis of the transport data of Muller et al [11] to the current and temperature dependence of the photoresponse. For the two gate and the four gate structures at T=1.3K it is essential that the bias current is fixed well below 1μA to get the optimum performance, as can be seen for the two gate finger structure of FIG. 15. Increasing the temperature from 1.3K to 4.2K at a fixed current of I=100nA reduces the photosignal by a factor of 2. These observations are consistent with the transport measurements [11]. The inventors have demonstrated that both the rise in current and the rise in temperature lead to an equilibration among the edge channels. Under these circumstances the possibility for a photon induced equilibration is reduced and one obtains a smaller photoresponse.
The photoresponse for FIG. 2 for a two gate finger structure can be enlarged by a factor of two by using the four gate finger structure of FIG. 4. For the two gate finger and the four gate finger structures an increase in resistance of about 7% was obtained for a laser intensity of about 10 -5 W/cm 2 .
In the presented measurements the 232 μm laser line matches the CR at a filling factor in the ungated region ν b =3.5. The gate voltage V g =220 mV sets the filling factor underneath the gate to ν g =1 at the CR position. These settings fulfill the two general requirements for an amplified photoresponse. At first, the filling factor ν b has to be larger than 2, because the two lowest Landau levels are only separated by a spin gap. Here, no CR absorption is possible. This requirement was checked experimentally, where a laser line was selected for the CR at ν b =2. A small PC signal at V g =OmV disappeared by tuning the gate voltage. Second, the filling factor ν g has to be adjusted so that at least the topmost edge channel is decoupled from the others. This statement was verified by measuring the photoresponse for three different filling factors ν b with the corresponding three different laser lines.
With regard to the resonance position in FIG. 14 the same result was obtained in the photoconductivity and the corresponding transmission experiment.
The sensitivity of the detector structure without Schottky gates in accordance with FIG. 11 was demonstrated in an impressive manner in FIG. 16. The irradiation by the 392 μm line led in curve a) to a large resonance at a magnetic field of 1.8T. Outside of the resonant magnetic field the resistances of the irradiated detector (curve a) were not substantially distinguished from those of the non-irradiated detector (curve b). In this way the narrow bandwidth of the detector was demonstrated.
In summary, it has been demonstrated that photon induced inter edge scattering is the dominant photoconductivity contribution in the presented multi gate finger structures. Although the photoconductor has to be operated at low temperatures and in the presence of a magnetic field the achieved responsitivity of 6.10 4 V/W favors the device for an application as a narrow band FIR detector. Due to the high sample quality the resolution at 3.2T is already τ/Δτ=40. For further improvement of the device the signal dependence on the number and the spacing of the gate fingers has to be investigated. In addition, higher sample mobilities and lower temperatures should raise the performance of the photoconductor, because adiabatic transport under these conditions is approached more closely.
References
[1]J.C. Maan, Th. Englert, D. C. Tsui, and A. C. Gossard, Appl.Phys. Lett. 40,609 (1982)
[2]D. Stein, G. Ebert, K. v. Kiltzing, and G. Weimann, Surf. Sci. 142,406 (1984)
[3]R. E. Horstman, E. J. v. d. Broek, J. Wolter, R. W. van der Heijden, G. L. J. A. Ridden, H. Sigg, P. M. Frilink, J. Maluenda, and J. Halais, Solid State commun. 50,753 (1984)
[4]M. J. Chou, D. C. Tsui, and A. Y. Cho, Proc. of 18th Intl. Conf. on the Phys. of Semiconductors (World Scientific, Singapore, 1986), Stockholm, Sweden, 1986, p. 437
[5]R. Landauer, IBM J. Res. Dev. 1,223 (1957)
[6]M. Buttiker, Phys. Rev. Lett. 57, 1751 (1986)
[7]G. Muller, D. Weiss, S. Koch, K. v. Kiltzing, H. Nickel, W. Schlapp, and R. Losch, Phys. Rev. B 42, 7633 (1990)
[8]M. Buttiker, Phys. Rev. B 38, 9375 (1988)
[9]B. V. Alphenaar, P. L. McEuen, R. G. Wheeler, R. N. Sacks, Phys. Rev. Lett. 64, 677(1990)
[10]C. T. Liu, B. E. Kane, D. C. Tsui, and G. Weimann, Appl.Fhys. Lett 55,162 (1989)
[11]G. Miiller, D. Weiss, S. Koch, K. v. Kiltzing, H. Nickel, W. Schlapp, and R. Losch, Proc. of 20th Intl. Conf. on the Phys. of Semiconductors, Thessaloniki, Greece, 1990, to be published
[12]R. J. Haug and K. v. Klitzing, Europhys. Lett. 10,489 (1989). | A semiconductor radiation detector with layer-wise construction and a contive region having a two-dimensional or quasi one-dimensional electron or hole gas is provided in which adiabatic transport in edge channels occurs at least regionally and in which at least two contacts are provided to this conductive region. The transport in the edge channels is disturbed by interaction with the electromagnetic radiation to be detected, i.e. an increase of the scattering rate between the edge channels is caused. This leads to a change of the resistance measurable between the contacts, with a means being provided for measuring the change of resistance to thereby detect the incident radiation. | 7 |
BACKGROUND OF THE INVENTION
Masks used in X-Ray lithography must, of necessity be very thin and flat. The masks must be in the order of 0.5 to 10 microns or less in thickness to transmit the X-Ray beam in sufficient strength to adequately expose the photoresist coating of a wafer. The masks must be optically flat, e.g., ideally to half a wavelength or better to minimize overlay registration error. The present invention provides a method for providing such an optically flat X-Ray mask.
BRIEF SUMMARY OF THE INVENTION
In carrying out the method of the present invention a thin film of material of the type used in X-Ray masks is peripherally supported by a transfer ring. The membrane is then centered onto a support ring whose surface has been polished to a flatness of better than one quarter wavelength. The membrane is epoxied to the outer edge of the support ring which has been slightly beveled. An annular weight is placed on the outer periphery of the transfer ring to place uniform tension on the membrane while the epoxy cures.
BRIEF DESCRIPTION OF THE DRAWINGS
FIG. 1 is a sectional view showing the membrane mounted on the transfer ring;
FIG. 2 is a sectional view showing the membrane mounted on the support ring with the weight in place; and
FIG. 3 is an enlarged view of a section of the support ring showing the beveled portion.
DESCRIPTION
FIG. 1 shows a thin membrane 11 fixed as by adhesive to a transfer ring 12. One method of providing such a structure is described in an article entitled X-Ray Lithography Mask Technology appearing in the Journal of the Electrochemical Society, Vol. 128, No. 5 May 1981 pps. 1116 to 1120.
The membrane 11 which may be composed of such materials as titanium, SiC, PMMA (poly methyl methacrylate) or polymide is very thin, e.g., membranes of titanium have been produced as thin as 0.4 μm. These membranes which are useful masks in X-Ray lithography are surprisingly rugged and capable of withstanding a high degree of stress and tension. However, the membranes are relatively slack on the transfer ring after removal from the substrate on which they are initially formed.
To be effective for use in X-Ray lithography the masks must be very flat, e.g., not varying by more than half a wavelength, e.g., measured in the visable range over a 12.5 cm diameter. This is necessary to minimize overlay registration errors as a wafer is exposed to an X-Ray source through succeeding masks as circuit patterns are built up on the wafer.
In order to provide the required degree of flatness Applicant centers and places the membrane 11 onto support ring 13 as shown in FIG. 2. The inner periphery of the surface 13a of the support ring 13 is polished to a flatness of better than one quarter wavelength. This is critical since the flatness of the surface of the support ring 13 ultimately determines the flatness of the membrane 11. The outer edge of the support ring is slightly beveled at 13b which is exaggerated in FIG. 2 to make it more discernable.
FIG. 3 illustrates more clearly the polished surface 13a and the bevel 13b. The beveled surface 13b is coated with a thin layer of epoxy prior to placement of the membrane 11. An annular weight 14 is placed on the outer periphery of the membrane 11 at the position of the transfer ring to place a uniform tension on the membrane 11. The epoxy is then allowed to cure which secures the membrane 11 to the support ring 13 and imparts a flatness to the membrane 11 of better than one half wavelength over its diameter. After the epoxy has been cured, the portion of the membrane 11 extending beyond the outer periphery of the support ring 13 is removed, e.g. by cutting with a razor leaving a drum-like structure with a membrane of optical flatness.
The use of the beveled surface 13b for fixing the membrane 11 to support ring is critical to insure appropriate flatness of the membrane. To fix the membrane directly to the surface of a support ring by applying epoxy thereto degrades the quality of the polished surface which in turn lessens the flatness achievable by the above method. This problem is, of course, eliminated by having the beveled surface 13b to which the epoxy may be applied while the polished surface on which the membrane rests is unaffected. The angle of the bevel relative to surface 13a is very small, e.g., approximately 5°.
Other modifications of the present invention are possible in light of the above description which should not be construed as placing limitations on the present invention other than those expressly set forth in the claims which follow. | A method for tensioning a thin film on a support ring to achieve an optically flat membrane. The support ring is optically flat with a slight bevel at its outside edge where the membrane is epoxied to the support ring. | 8 |
FIELD OF THE INVENTION
The present invention relates to opening devices for packaging containers and more particularly to a method for distributing and preparing opening devices for application on packaging containers.
BACKGROUND OF THE PRIOR ART
Within the packaging industry, relating in particular to packages for liquid foods such as milk and juice, it is a normal occurrence that an opening device is applied on the outside of the packaging container in order to facilitate the consumer's access to the enclosed content. These opening devices are applied to the outside of the package in an applicator. This applicator most generally operates in such a manner that the opening devices must be oriented in a given way. In order to facilitate this operation, the opening devices should, in some way, be held together so that they are oriented in the same way. Furthermore, it should not be possible for the opening devices to catch in one another or lie against one another so that they run the risk of becoming deformed. Such an opening device which is applied may, for example, consist of an outer pouring part and a closing part.
OBJECTS AND SUMMARY
One object of the present invention is to devise a method of distributing relatively small parts intended to be applied to packaging containers so that the parts are brought, or marshalled, together into a web or a sheet form, which facilitates handling and permits the applicator to be run at a higher speed.
A further object of the present invention is, by an automatic, continuous process, to unite the individual parts together in a simple and economical manner.
These and other objects have been attained according to the present invention in which opening device the parts are connected in rows and are positioned and closed in that said pouring part is closed by a snap-in closure to the closing part. Either the pouring part or the closing part on two or more of the parts in a row, are provided with a projection and a number of similarly prepared rows are joined into a web or a sheet in that the projections on one row are welded together with the corresponding opening device parts on a neighbouring row.
BRIEF DESCRIPTION OF THE ACCOMPANYING DRAWINGS
One preferred embodiment of the present invention will now be described in greater detail hereinbelow, with particular reference to the accompanying Drawings, in which
FIG. 1 is a top view of a row of opening part devices;
FIG. 2A is a perspective view of a step of extruding opening parts from an extruder;
FIG. 2B is a perspective view of a step of reversing every other row of opening parts;
FIG. 2C is a perspective view of a step of closing the opening parts;
FIG. 2D is a perspective view of a step of arranging adjacent rows of opening parts;
FIG. 2E is a perspective view of a step of welding the rows of opening parts into sheets;
FIG. 2F is a perspective view of a sheet of opening parts of a size x by y;
FIG. 2G is a perspective view of a step of packaging a plurality of sheets in a box or crate; and
FIG. 3 is a side view partly in section, of the opening parts being welded together to form a web or sheet.
DESCRIPTION OF PREFERRED EMBODIMENT
The opening device parts which are intended to be distributed according to the present invention consist of a pouring part 2 and a closing part 3 manufactured in one piece, which is to be applied on the outside of a packaging container. Such a packaging container may be constituted by a parallelepipedic package consisting of a laminate with an outside of a thermoplastic layer. This parallelepipedic package is provided with an aperture which is covered by a so-called pull-tab, and the opening device part 1 is intended to be applied around and over the pull-tab.
FIG. 1 shows a number of parts 1, as they appear when they have been extruded. The parts 1 are manufactured from plastic material. In this phase, the opening device part 1 is open. The pouring part 2 is intended to be fixed against the outside of the packaging container, and the closing part 3 is passed over the pouring part 2. The pouring part 2 and closing part 3 of an opening device part 1 are united by the intermediary of a hinge piece 4. When the parts 1 are extruded, they are united in a row comprising an X number of opening device parts 1.
On two or more of the closing parts 3 of the opening device part 1, there are small projections 5 projecting outside the edge, these projections are intended to be used for the uniting of a number of rows into a web form. In FIG. 1, and in the preferred embodiment, the two outermost opening device parts 1 on each side are provided with projections 5, this in order to impart greater stability to the web. Alternatively the projections 5 are provided to the pouring part 2 of the opening device part 1.
The parts 1 may be applied on the packaging container in the appearance as shown in FIG. 1, but they may also be closed, in that the closing part 3 is brought together with the pouring part 2 by the whole opening device part 1 being folded over in its hinge piece 4, and closed by means of a snap-in closure.
FIGS. A-G show the process for obtaining a suitable distribution unit for the above described parts 1. When the parts 1 depart from the extruder 6, they arrive in a number of rows of length x. Since the extruder 6 is symmetrically designed and constructed, the rows are mirror-reversed in relation to one another, two-by-two. In order to marshal together the objects 1 to web form, every other row must, therefore, be positioned (FIG. 2B) in that, for example, every other row is lifted by suction cups and rotated through 180°.
In the preferred embodiment, the parts 1 are intended to be applied in the closed state, for which reason the closing part 3 must be brought together with the pouring part 2, as shown in FIG. 2C. Further, the now closed part 1 are marshalled together in a line in sequence after one another as shown in FIG. 2D.
The rows of parts 1 of length x are retained in a fixture device and are fused or welded together with the subsequent row at the projections 5 with which two or more of the opening device parts 1 are provided.
Given that this process is continuous and automatic, the opening device parts 1 will thus be marshalled together to a web or a sheet form. This may possibly be fed directly to an applicator machine, but since manufacture of the parts 1 most generally does not coincide with application of the objects 1 themselves, it is appropriate to sever the web form into suitable sheets of a size x by x which can be packed in a box or crate to a suitable height z. This is illustrated in FIGS. 2F-G.
FIG. 3 shows the welding operation, which is suitably carried out by means of an ultrasonic horn 7 since, by such means, a directed welding will be obtained of the small surfaces which are contemplated here. Another method of bringing together the projections 5 with the immediately subsequent row can be by heating the projections 5 on one row and the opening device parts 1 on the subsequent row to the melting temperature. The projections 5 are placed so that they rest against the hinge piece 4 on the subsequent row and should be suitably small that they do not obstruct the function of the opening device part 1, nor do they affect its appearance. At the same time, they constitute such slight material quantity that the cost increase will be negligible.
As illustrated in FIG. 3, the projections 5 have a minor indication of fracture 6 where they are secured to the hinge piece 4 of an adjacent opening device part 1. When the web or sheet parts 1 are fed into the applicator, the parts 1 are severed from one another partly on the x-axis and partly on the y-axis into individual parts 1 which are taken charge of by the applicator and secured to the outside of the package using a hot-melt process, or alternatively by heating of the opening device part 1 or the outer thermoplastic layer of the package, respectively.
As will have been apparent from the foregoing description, the present invention realises a method of distributing separate parts intended to be applied on a packaging container so that the parts are easy to handle and cannot be deformed in the event of unsuitable storage. The method also makes it possible for the applicator to operate with continuous and even advancement of the parts which are correctly oriented, and, as a result the applicator may be run at higher speed.
The present invention should not be considered as restricted to that described above and shown on the Drawings, many modifications being conceivable without departing from the spirit and scope of the appended claims. | The invention relates to a method of distributing opening devices and preparing the opening devices for application individually to a packaging containers. The opening devices are positioned, closed and marshalled together to form a web or a sheet. The prefabricated opening devices are arranged in rows of length x. Two or more of the opening devices in each row are provided with projections which are placed against corresponding opening devices in a neighboring row and are welded together using ultrasonic means. | 1 |
RELATED APPLICATIONS
This application is a continuation-in-part of application Ser. No. 243,575, filed Sept. 13, 1988, now abandoned.
FIELD OF THE INVENTION
The present invention relates to a process and composition for improving the printability, dyeability and/or whiteness of cellulosic fabrics. More particularly, the invention relates to a process for improving the whiteness and/or dyeing characteristics of cellulosic fibers and/or fabrics through the use of a chlorohydroxylalkyltrialkyl ammonium salt or an epoxy lower alkyl ammonium salt alone or in combination with sodium sulfate.
BACKGROUND OF THE INVENTION
Cellulosic textiles, prior to dyeing or printing in commercial operations, usually undergo treatment with caustic to remove fats, oils or other materials. The process is called "scouring" and is generally performed with a solution of caustic soda at elevated temperatures. Following the scouring process, the fabric is subjected to steaming.
To improve the whiteness of the fabrics, the fabrics are usually subjected to a bleaching step with a peroxide solution. Following bleaching, the fabrics are also subjected to steaming, washing and drying.
However, there are fabric treating operations which do not employ caustic scouring baths. In place of scouring a two step bleaching operation is commonly utilized.
It is known to treat cotton with quaternary salts to improve its dyeability. Choline chloride has been utilized but it has the drawback of being sensitive to changes in curing temperature.
The presence of the quaternary compound in the bleach bath results in a greater uptake of any anionic fabric brightener.
U.S. Pat. No. 3,685,953 to Cavelier et al, which is herein incorporated by reference, discloses the utilization of an epoxypropyl ammonium salt with a strong mineral base as a fixation catalyst during scouring in order to improve the dyeability of cellulosic fibers. The epoxypropyl ammonium salt is used with at least 0.5% of the base as a catalyst to cause fixation of the epoxypropyl ammonium salt.
The measurement of colors in the present application is pursuant to the Adams-Nickerson or AN/AB space known as CIELAB. In this color space, "a" represents red/green, "+a" being red, "-a" being green, "b" represents yellow/blue, "+b" being yellow, "-b" being blue.
The term "fabric" as used herein is intended to include textile materials such as filaments, yarns, tows, battings, woven and non-woven cloth, knitted fabric and the like.
SUMMARY OF THE INVENTION
The present invention relates to an improvement in the process of treating cellulosic fabrics so as to improve their whiteness and/or their dyeability or printability. More particularly, the invention is concerned with the treatment of a cellulosic fabric in a process which includes the steps of scouring and/or bleaching with a quaternary compound of the formula selected from the group consisting of: ##STR2## wherein R, R,' R" and R''' are each lower alkyl radicals and X is an anion, subsequent to scouring. Preferably, the compounds are chlorohydroxypropyltrimethylammonium chloride or epoxypropyl trimethylammonium chloride. The quaternary compound is utilized in an aqueous solution in an amount of about 0.1 to 15% by weight of solution, preferably, about 0.5-2.0%.
The chlorohydroxy alkyl trialkyl ammonium salt is utilized in processes which do not utilize a scouring bath, that is, only within a bleach bath.
The sodium sulfate is believed to enhance reactivity with available alcoholates, which are produced in the scouring step. It has been found that the use of the quaternary compound in the bleaching step improves the dyeability of the fabric. This treatment of the fabric has been found to produce leveling of pigment in the printing process and to reduce the pigment requirement in some cases as much as 20%. Generally, there was found to be an improvement in printing and dyeing with anionic dyes and pigments.
The present invention can be utilized with all cellulosic materials such as cotton, linen, flax, viscose, and the like. Cotton fabrics with enhanced durability press properties derived from treatment with crosslinking resins have also been improved in their dyeability with the process of the invention.
It is therefore an object of the present invention to improve the dyeability of cellulosic materials through the use of chlorohydroxyalkyltrialkylammonium salt or its epoxy form.
It is another object of the invention to provide a means for reducing the amount of pigment required in the printing of cellulosic fabrics.
It is a further object of the invention to improve uniformity in dyeing of cellulosic materials.
It is a yet still further object of the invention to improve the reactivity of chlorohydroxyalkyltrialkylammonium salts or epoxy lower alkyl ammonium salts with cellulosic fabrics.
Other objects and a fuller understanding of the invention will be had by referring to the following description and claims of preferred embodiments, taken in conjunction with the accompanying drawing.
BRIEF DESCRIPTION OF THE DRAWING
The drawing is a schematic representation of the treatment of cellulosic fibers prior to dyeing including a fabric treatment section according to the invention.
DESCRIPTION OF THE PREFERRED EMBODIMENT
Although specific terms are used in the following description for the sake of clarity, these terms are intended to refer only to the particular structure selected for illustration in the drawing, and are not intended to define or limit the scope of the invention.
The drawing schematically represents a typical fabric treatment process with several treatment areas which includes the various embodiments of the present invention so as to result in a cellulosic fabric of improved whiteness and/or improved dyeing characteristics. As shown, a cellulosic fabric 10 is preferably passed in countercurrent flow through a scouring bath 14 by means of rolls 12 in a continuous process. However, the process may be carried out step-wise or batchwise depending upon the fabric.
The scouring bath 14, which generally comprises a 2 to 10% solution of sodium hydroxide and about 0.1 to 0.5% detergent, is at ambient to elevated temperature (about 100° C). If desired, epoxypropyl trimethylammonium chloride may optionally be added to the bath according to the process. The scouring process produces alcoholates (for example, sodium alcoholates) in the fabric.
Following the scouring bath, the fabric may be conveyed to a steamer 18 after passage through contact or squeegee rolls 16, 16' and a conveyor roll 17. The treatment in the steamer 18 is usually for a period of about one half hour. However, in lieu of placing the epoxypropyl trimethylammonium chloride in the scouring bath it may be applied to the fabric prior to steaming.
After the steam treatment the fabric is conveyed from the steamer 18 over a conveyor roll 17 to a vacuum or aspirator means 20 for removal of a substantial portion of any residual sodium hydroxide solution. Also, the fabric may be washed with brine or water to remove alkaline residue from the fabric.
The fabric is then treated with about 0.1 to about 15%, preferably about 0.7-2% on weight fabric of epoxypropyl trimethylammonium chloride. As shown, the fabric 10 preferably passes in countercurrent flow through the bath 31 which contains the epoxypropyl trimethylammonium chloride.
In lieu of bath 31, the fabric may be sprayed or treated with a foam and vacuum process.
Advantageously, the bath also contains sodium sulfate in an amount up to about 35% by weight of solution, preferably, about 25-30% by weight. The presence of the sodium sulfate is believed to aid in the fixation of the epoxypropyl trimethylammonium chloride by increasing the availability of the alcoholate groups of the cellulosic fabric and the epoxy groups for reaction.
It is preferable, but not essential, that the fabric after treatment with epoxypropyl trimethylammonium chloride be steam treated. The steam treatment aids in affixing the epoxypropyl trimethylammonium chloride to the alcoholate groups of the cellulosic fabric 10. In some cases, the fabric is next washed, dried and then treated with an anionic dye without any other treatment steps.
In the procedure illustrated, the fabric 10 proceeds to a bleaching bath 26 wherein it is treated with a bleaching solution. The bleaching solution consists of a solution of hydrogen peroxide or sodium hypochlorite in an amount of about 0.5 to 6.0%, preferably about 0.5 to 2% by weight of solution.
It is understood however, that the employment of the quaternary compound, especially chlorohydroxypropytrimethylammonium chloride is preferably utilized where in lieu of the scouring bath a bleach bath is utilized.
When the bleaching solution comprises hydrogen peroxide, the bleach step is preferably followed by treating with steamer in steamer 28 and then a countercurrent rinsing in a water bath 30 as shown in the drawing. The fabric 10 may then be further processed as required prior to printing or dyeing, for example, aspirating and drying.
It is understood that all percentages as herein utilized are based on weight percentage.
Exemplary of the present invention are set forth in the following examples:
EXAMPLE 1
A. Scouring and Preparation of Alcoholates
A 2"×4" specimen of cotton twill cloth was immersed in 200 cc of boiling 10% NaOH, removed, passed through a laboratory padder, returned to the boiling NaOH solution and then refluxed for five minutes. The specimen was removed and washed ten times with 500 cc volumes of deionized water. The pH of the water squeezed from the cloth was neutral.
The above procedure was repeated using of 5% solution of LiOH instead of 10% NaOH.
B. Reaction with Epoxypropyl Trimethylammonium Chloride
Epoxypropyl trimethylammonium chloride was prepared by heating 200cc of 4% solution of 3-chloro, 2-hydroxypropyl trimethlyammonium chloride to 50° C. and a stoichiometric quantity of NaOH. 90 g. of Na 2 SO 4 was added to the solution and the temperature was raised to boiling. Cotton cloth which had been refluxed in alkali metal hydroxide and then washed as described in Part A, was placed in the epoxide solution. The solution was buffered to pH7. The cotton was removed, passed through a laboratory padder, returned to the liquid mixture and then refluxed for one hour. The specimens were then aspirated in a Buchner funnel to remove entrained moisture and placed in an oven at 120° C. for 30 minutes. The samples were then washed ten times with 500 cc volumes of deionized water and analyzed for Nitrogen using an ANTEC™ nitrogen analyzer.
______________________________________Specimen ppm N______________________________________NaOH alcoholate, washed 560LiOH alcoholate, washed 550Control (no alcoholate formation) 220______________________________________
EXAMPLE 2
A specimen of cotton cloth, treated with dimethylol dihydroxyethyleneurea (DMDHEU) crosslinking resin was treated according to the procedure described in Part A of Example 1, and then washed ten times in 500 cc volumes of deionized water. Then the specimen was cationized by reacting it in a bath of 4% epoxypropyl trimethylammonium chloride containing 20 g/100 cc of sodium sulfate. The reaction mixture was buffered to pH 7 and allowed to react for one hour. At the end of one hour, the cloth was removed from the reaction mixture and washed ten times with deionized water.
The specimen was then dyed with Althouse brand Superlitefast™ blue direct dye under the following conditions:
a) 30:1 ratio bath to cloth
b) 2% dye based on wt cloth
c) 100° C. for one hour
d) no salt used
Along with the alkali-treated specimen was also dyed a specimen of the identical durable press crosslinked fabric which had not been alkali-treated and washed. After dyeing, the specimens were washed in two liters of deionized water containing 0.5% detergent at 60° C. for one hour. Then the specimens were rinsed with deionized water and dried at room temperature. The dye uptake of the specimens was compared by taking reflectance measurements on the cloth with and without the alkali treatment. A Photovolt model 577 reflectance meter with a blue color filter was used. The lower the reflectance the greater the amount of dye uptake.
______________________________________Specimen Description Reflectance______________________________________1. NaOH treatment & deionized 7.4 water wash followed by treatment with epoxy compound2. NaOH treatment & deionized 32.2 water wash followed by boiling twice in deionized water3. Epoxy compound application 64.2 without NaOH treatment4. Control (blank cloth 68.8 without epoxy compound)______________________________________
EXAMPLE 3
The effect of Na 2 SO 4 on the level of Nitrogen Fixation in the Reaction of Epoxy Compound with Cotton Cloth
A. Alkali pre-treatment: two 2"×4" specimens of style #423 cotton twill test fabric were immersed in boiling 5% Lithium Hydroxide. They were removed, passed through a laboratory padder, returned to the LiOH solution and refluxed for 5 minutes. The specimens were then removed, drained on a paper towels and passed through a laboratory padder to remove most of the moisture.
B. A 2% solution of 3-chloro, 2-hydroxypropyl trimethylammonium chloride was brought to 50° C. and stoichiometrically neutralized with NaOH. It was divided into two portions wherein each contained a specimen. To one portion was added an excess of sodium sulfate. The solutions were brought to boiling (107° C. for the solution saturated with sodium sulfate) and allowed to reflux for one hour. The pH of the refluxing solution was 10-11. After one hour the specimens was removed, placed in a beaker of deionized water, neutralized with dilute HCI and then washed ten times with 500 cc volumes of deionized water. The specimens were analyzed for Nitrogen using an ANTEK™ Nitrogen analyzer.
______________________________________Results:Specimen Description N.ppm______________________________________1. Cotton cloth reacted in 752 the absence of Na.sub.2 SO.sub.42. Cotton cloth reacted in the 1085 system saturated with Na.sub.2 SO.sub.43. Control (untreated cotton essentially zero cloth)______________________________________
EXAMPLE 4
Pairs of enzyme desized and caustic scoured Testfabrics style 428R 100% cotton fabric patches are treated in 2% hydrogen peroxide baths at various pH's stabilized with 0.15% MgCl 2 6H 2 O, 0.25% (solids basic) Primacor 5980® Dow Adhesive Polymer Ethylene/Acrylic Acid Dispersion, 0.2% Synthrapol non-ionic wetting agent, and 0.5% Sorbitol. Each pair of patches is divided into a control and a test patch. Four control patches is are treated in the above described bleach baths which have each been modified by the addition of 0.5% (solids basic) Quat 188- Dow Chemical Company propyl chlorohydrin trimethyl ammonium chloride. The 11.5 inch by 6.75 inch patches are kept damp after the scouring step. Each patch is double dipped and double padded through its bath for an 85% to 90% wet pickup. The sample is sealed in a type 5A Launderometer container and immersed in a boiling water bath for 45 minutes. The bleached patches are washed in two changes of 50 to 1 liquor to goods ratio boiling deionized water and one 100 to 1 ratio cool deionized water wash. The patches are padded to 70% wet pickup and allowed to air dry at room temperature. The samples are then dyed in a beaker containing 1.0% OWG (on weight goods) direct green No. 26 dye at 95 degrees Centigrade and a 10:1 liquor to goods ratio for a duration of 60 minutes. After dyeing, the samples are rinsed in deionized water, air dried, and ironed flat. Color measurements are then made on each sample using a Hunterlab D25 colorimeter at six different points on the sample, taking L, a and b spectrum measurements. Data tabulated on this experiment are shown in Table 1.
TABLE 1__________________________________________________________________________Study of dyeability of 100% cotton printcloth treated withpropychlorohydrintrimethylammonium chloride .15% MgCl.sub.2.6H.sub.2 O , .25% EAA, .2%Synthropol,and .5% sorbitol in the bleach bath them dyed with green direct dye No.26SAMPLE 2 2C 3 3C 4 4C 6 6C__________________________________________________________________________Percent 86.1% 86.2% 88.4% 88.2% 87.0% 87.4% 86.8% 90.0%Wet PickupWt % Chptmac 0.50% 0.00% 0.50% 0.00% 0.50% 0.00% 0.00% 0.00%OWBWt % H.sub.2 O.sub.2 1.92% 1.97% 1.94% 2.00% 1.89% 1.95% 2.02% 1.98%OWBpH 10.00 10.00 10.33 10.33 10.67 10.67 11.00 11.00ColorCielab L 53.0 55.0 52.4 54.7 52.8 55.5 51.0 53.9Cielab a -20.6 -20.1 -20.6 -20.2 -20.3 -20.1 -20.8 -19.9Cielab b 1.1 1.5 1.2 1.2 1.4 1 1.5 1.1__________________________________________________________________________
EXAMPLE 5
Following the procedure of Example 4, however, direct blue No. 25 dye is used instead of direct green No. 26. In this experiment, pairs of enzyme desized and caustic scoured Testfabrics style 428R 100% cotton fabric patches are treated in 2% hydrogen peroxide baths at various pH stabilized with 0.15% MgCl 2 .6H 2 O, 0.25% (solids basic) Primacor 5980* Dow Adhesive Polymer Ethylene/Acrylic Acid Dispersion, 0.2% Synthrapol non-ionic wetting agent, and 0.5% Sorbitol. Each pair of patches is divided into a control and a test patch. Four control patches are treated in the above described bleach bath at individual experiment pH's of 10, 1033, 10.67, and 11. Four test patches are treated in the above described bleach baths which have each been modified by the addition of 0.5% (solids basic) Quat 188--Dow Chemical Company propyl chlorohydrin trimethyl ammonium chloride. The 11.5 inch by 6,75 inch patches are kept damp after the scouring step. Each patch is double dipped and double padded through its bath for an 85% to 90% wet pickup. The sample is sealed in a type 5A Launderometer container and immersed in a boiling water bath for 45 minutes. The bleached patches are washed in two changes of 50 to 1 liquor to gods ratio boiling deionized water and one 100 to 1 ratio cool deionized water wash. The patches are padded to 70% wet pickup and allowed to air dry at room temperature. The samples are then dyed in a beaker containing 1.0% OWG (on weight goods) direct blue No. 25 dye at 95 degrees Centigrade and a 10:1 liquor to goods ratio for a duration of 60 minutes. After dyeing, the samples are rinsed in deionized water, air dried, and ironed flat. Color measurements are then made on each sample using a Hunterlab D25 colorimeter at six different points on the sample, taking L, a and b spectrum measurements. Data tabulated on this experiment are shown in Table 2.
TABLE 2__________________________________________________________________________Study of dyeability of 100% cotton printcloth treated withpropychlorohydrintrimethylammonium chloride 15% MgCl.sub.2.6H.sub.2 O, .25% EAA, .2%Synthropol,and .5% sorbitol in the bleach bath them dyed with green direct dye No.25SAMPLE 2 2C 3 3C 4 4C 6 6C__________________________________________________________________________Percent 86.1% 86.2% 88.4% 88.2% 87.0% 87.4% 86.8% 90.0%Wet PickupWT % Chptmac 0.50% 0.00% 0.50% 0.00% 0.50% 0.00% 0.50% 0.00%OWB*Wt % H.sub.2 O.sub.2 1.92% 1.97% 1.94% 2.00% 1.89% 1.95% 2.02% 1.98%OWBpH 10.00 10.00 10.33 10.33 10.67 11.00 11.00 11.00ColorCielab L 53.4 56.2 51.8 55.2 51.8 55.3 49.4 54.1Cielab a -0.2 0.7 1.7 1 1 0.2 2.7 1.3Cielab b -29.8 -29.8 -32.1 -31 -30.8 -30.2 -33.3 -31.8__________________________________________________________________________ *On Weight Bath
EXAMPLE 6
The procedure of Example 4 was followed except that there was used a bleach bath stabilizer system containing less Sorbitol and MgCl 2 in solution. In this experiment, pairs of enzyme desized and caustic scoured Testfabrics style 428R 100% cotton fabric patches are treated in 2% hydrogen peroxide baths at various pH's stabilized with 0.075% MgCl 2 .6H 2 O, 0.25% (solids basis) Primacor 5980* Dow Adhesive Polymer Ethylene/Acrylic Acid Dispersion, 0.2% Synthrapol non-ionic wetting agent, and 0.2% Sorbitol. Each pair of patches is divided into a control and a test patch. Four control patches are treated in the above described bleach bath at individual experiment pH's of 10, 10.33, 10.67 and 11. Four test patches are treated in the above described bleach baths which have been modified by the addition of 0.5% (solids basic) Quat 188--Dow Chemical Company propyl chlorohydrin trimethyl ammonium chloride. The 11.5 inch by 6.75 inch patches are kept damp after the scouring step. Each patch is double dipped and double padded through its bath for an 85% to 90% wet pickup. The sample is sealed in a type 5A Launder-ometer container and immersed in a boiling water bath for 45 minutes. The bleached patches are washed in two changes of 50 to 1 liquor to goods ratio boiling deionized water and one 100 to 1 ratio cool deionized water wash. The patches are padded to 70% wet pickup and allowed to air dry at room temperature. The samples are then dyed in a beaker containing 1.0% OWG (on weight goods) direct blue No. 25 dye at 95 degrees Centigrade and a 10:1 liquor to goods ratio for a duration of 60 minutes. After dyeing, the samples are rinsed in deionized water, air dried, and ironed flat. Color measurements are then made on each sample using a Hunterlab D25 colorimeter at six different points on the sample, taking L, a and b spectrum measurements. Data tabulated on this experiment are shown in Table 3.
TABLE 3__________________________________________________________________________Study of dyeability of 100% cotton printcloth treated withpropychlorohydrintrimethylammonium chloride .15% MgCl.sub.2.6H.sub.2 O, .25% EAA, .2%Synthropol,and .5% sorbitol in the bleach bath them dyed with green direct dye No.25SAMPLE 7 7C 8 8C 10 10C 11 11C__________________________________________________________________________Percent 88.3% 87.3% 87.6% 86.9% 88.3% 83.0% 85.0% 82.8%Wet PickupWT % Chptmac 0.50% 0.00% 0.50% 0.00% 0.50% 0.00% 0.50% 0.00%OWB*Wt % H.sub.2 O.sub.2 1.96% 1.98% 1.97% 1.96% 1.96% 1.97% 1.94% 1.96%OWBpH 10.00 10.00 10.33 10.33 10.67 10.67 11.00 11.00ColorCielab L 52.2 54.5 52.7 56.4 51.6 55.8 51.7 56.5Cielab a -20.4 -20.1 -20.2 -20.0 -20.6 -19.9 -20.5 -19.7Cielab b 1.0 1.2 1.1 1.2 1.1 1.2 1.0 1.0__________________________________________________________________________ *On Weight Bath
EXAMPLE 7
The procedure of Example 4 was followed except that there was used a bleach bath stabilizer system containing less Sorbitol and MgCl 2 in solution. In this experiment, pairs of enzyme desized and caustic scoured Testfabrics style 428R 100% cotton fabric patches are treated in 2% hydrogen peroxide baths at various pH's stabilized with 0.075% MgCl 2 .6H 2 O, 0.25% (solids basic) Primacor 5980* Dow Adhesive Polymer Ethylene/Acrylic Acid Dispersion, 0.2% Synthrapol non-ionic wetting agent, and 0.2% Sorbitol. Each pair of patches is divided into a control and a test patch. Four control patches are treated in the above described bleach bath at individual experiment pH's of 10, 10.33, 10.67 and 11. Four test patches are treated in the above described bleach baths which have been modified by the addition of 0.5% (solids basic) Quat 188--Dow Chemical Company propyl chlorohydrin trimethyl ammonium chloride. The 11.5 inch by 6.75 inch patches are kept damp after the scouring step. Each patch is double dipped and double padded through its bath for an 85% to 90% wet pickup. The sample is sealed in a type 5A Launder-ometer container and immersed in a boiling water bath for 45 minutes. The bleached patches are washed in two changes of 50 to 1 liquor to goods ratio boiling deionized water and one 100 to 1 ratio cool deionized water wash. The patches are padded to 70% wet pickup and allowed to air dry at room temperature. The samples are then dyed in a beaker containing 1.0% OWG (on weight goods) direct blue No. 25 dye at 95 degrees Centigrade and a 10:1 liquor to goods ratio for a duration of 60 minutes. After dyeing, the samples are rinsed in deionized water, air dried, and ironed flat. Color measurements are then made on each sample using a Hunterlab D25 colorimeter at six different points on the sample, taking L, a and b spectrum measurements. Data tabulated on this experiment are shown in Table 3.
TABLE 4__________________________________________________________________________Study of dyeability of 100% cotton printcloth treated withpropychlorohydrintrimethylammonium chloride .15% MgCl.sub.2.6H.sub.2 O, .25% EAA, .2%Synthropol,and .5% sorbitol in the bleach bath them dyed with green direct dye No.25SAMPLE 7 7C 8 8C 10 10C 11 11C__________________________________________________________________________Percent 88.3% 87.3% 87.6% 86.9% 88.3% 83.0% 85.0% 82.8%Wet PickupWT % Chptmac 0.50% 0.00% 0.50% 0.00% 0.50% 0.00% 0.50% 0.00%OWB*Wt % H.sub.2 O.sub.2 1.96% 1.98% 1.97% 1.96% 1.96% 1.97% 1.94% 1.96%OWBpH 10.00 10.00 10.33 10.33 10.67 10.67 11.00 11.00ColorCielab L 51.6 55.6 51.3 56.0 49.8 56.5 50.1 56.0Cielab a 1.7 1.8 1.8 0.6 2.7 -0.1 3.4 1.2Cielab B -31.5 -32.0 -32.0 -30.3 -33.2 -29.2 -34.0 -31.4__________________________________________________________________________ *On Weight Bath
EXAMPLE 8
This experiment shows that propylchlorohydrin trimethyl ammonium chloride can be incorporated into a hydrogen peroxide bleach bath for the purpose of improving utilization of a fabric brightener also contained in the bleach bath. In this experiment, enzyme desized and 4% OWB caustic scoured Testgabrics style 428R 100% cotton fabric samples are treated in a 2% hydrogen peroxide bath at a pH of 10.8 stabilized with 0.15% Mg Cl 2 6H 2 O. 0.25% (solids basis), Primacor 598® (Dow Adhesive Polymer Ethylene/Acrylic Acid Dispersion), 0.2% Triton non-ionic wetting agent, and 0.2% dodecylbenzenesulfonic acid. All fabric samples measure approximately 10 inch by 7 inch. Caustic scouring is performed with each sample by first padding 4% OWB (on weight bath) caustic, 0.25% sodium laurel sulfate, and other additives required in the individual run on the fabric at an 85% wet pickup. The sample is then sealed in a type 2A launder-ometer container and held at 93 degrees for 30 minutes. The sample is then boiled in 800 mls. deionized water, padded to minimum wet pickup and left wet until bleaching is commenced. Fabric sample No. 1 is prepared in the unaltered bleach bath described above. Fabric sample No. 2 is treated in the previously described bleach bath additionally containing 0.5% OWB Mobay Phor-white BA brightener. Fabric sample No. 3 is treated in the above described bleach bath additionally containing 0.5% OWB Mobay Phor-white brightener. Fabric sample No. 3 is treated in the above described bleach bath additionally containing 0.5% OWB Mobay Phor-white 8a brightener and 1% OWB (solid basis) Dow Chemical Company Quat 188 propyl chlorohydrin trimethyl ammonium chloride. Fabric sample No. 4 is prepared just like sample No. 3 with the exception that 1% Quat 188 OWB is incorporated in the 4% caustic scouring bath. Fabric sample No. 5 is prepared just like sample No. 2 with the exception that 1% Quat 188 OWB is incorporated in the 4 % caustic scouring bath. Fabric sample No. 6 is prepared just like sample No. 2 with the exception that 1% Quat 188 OWB and 2% sodium borate are incorporated in the 4% caustic scouring bath. In each preparation, the sample is double dipped and double padded through its bleach bath for an 85% to 90% wet pickup. The sample is sealed in a type 5A Launder-ometer container and agitated in a 93 degree Celsius bath for 45 minutes. The bleached sample is boiled for 20 minutes each in two changes of 50 to 1 liquor to goods ratio boiling deionized water, padded to minimum wet pickup and then dried in a Kenmore dryer. The sample is steam-iron pressed and then allowed to equilibrate on the benchtop for one hour before being measured for Whiteness Index on the Hunterlab D25 colorimeter at six different points on the sample, taking L, a and b spectrum measurements. Data tabulated on the three samples in this experiment are shown in Table 5.
After the whiteness index is measured on each sample, an ultraviolet filter is used to remove the ultraviolet from the light source and the whiteness index is again measured. The difference between the whiteness indicies is tabulated as "whiteness differences".
TABLE 4______________________________________Study of whiteness index of 100% cotton army carded sateentreated with propychlorohydrin trimethylammonium chloride.15% MgCl.sub.2.6H.sub.2 O, .25% EAA, .2% dodecylbenzenesulonicacid in a pH 10.8, 2% OWB hydrogen peroxide bleach bathcontaining Mobay Phorwhite 8A fabric brightenerSAM-PLE 1 4 2 3 5 6______________________________________Percent 79.0% 80.40% 72.7% 79.6% 72.70% 76.0%WetpickupWt % 0.0% 1.0% 0.0% 0.0% 1.0% 1.0%ChptmacOWB incausticscourWt % 0.0% 0.0% 0.0% 0.0% 0.0% 2.0%sodiumborateOWB incausticscourWt % 0.0% 1.0% 0.0% 1.0% 0.0% 0.0%ChptmacOWB inbleachbathWt % 0.0% 0.5% 0.5% 0.5% 0.5% 0.5%bright-enerOWB inbleachbathColorCielab L 96.0 95.6 96.0 96.2 95.8 96.0Cielab a -0.4 3.6 3.3 3.5 3.7 3.9Cielab b -0.2 -6.8 -7.4 -7.6 -8.1 -8.4White- 90.7 128.2 133.0 135.2 136.4 139.0nessIndexWhite- 0.0 37.5 42.3 44.5 45.7 48.3nessDiffer-ence______________________________________
EXAMPLE 9
The following experiment was performed to illustrate that propylchlorohydrin trimethyl ammonium chloride can be incorporated into a hydrogen peroxide bleach bath for the purpose of improving the application of fiber reactive dye to the cellulosic fiber bleached and treated in the bath. In this experiment, enzyme desized and 4% OWB caustic scoured Testgabrics style 428R 100% cotton fabric samples are treated in a 1% hydrogen peroxide bath at a pH of 10.8 stabilized with 0.15% Mg Cl 2 6H 2 O. 0.25% (solids basis), Primacor 5980® (Dow Adhesive Polymer Ethylene/Acrylic Acid Dispersion), 0.2% Triton non-ionic wetting agent, and 0.2% dodecylbenzenesulfonic acid. Each fabric samples measures approximately 8 inch by 1.5 inch. Caustic scouring is done to each sample by first padding 4% OWB (on weight bath) caustic, 0.25% sodium laurel sulfate on the fabric at an 85% wet pickup. The sample is then sealed in a type 2A launder-ometer container and held at 100 degrees for 30 minutes. The sample is then boiled in 800 mls. deionized water, padded to minimum wet pickup and left wet until bleaching is commenced. Fabric sample No. 1 is prepared in the unaltered bleach bath described above. Fabric sample No. 2 is treated in the original bleach bath additionally containing 0.5% OWB Dow Chemical Company Quat 188 propylchlorohydrin trimethyl ammonium chloride. Fabric sample No. 3 is treated in the above described bleach bath additionally containing 1.0% OWB epoxy compound. Fabric sample No. 4 is prepared like sample No. 2 with the exception that 0.6% epoxy compound in the caustic scouring bath. In each preparation, the sample is double dipped and double padded through its bleach bath for an 85% to 90% wet pickup. The sample is sealed in a type 5A Launder-ometer container and agitated in a 100 degree C. bath for 1 hour. The bleached sample is washed in 50 to 1 liquor to goods ratio boiling water followed with several rinses in cool deionized water. It is then padded to minimum wet pickup and dried in a Kenmore clothes dryer. The samples are then dyed using a Cotton Incorporated procedure shown in Table 7A. The composition of the dye bath incorporates 0.5% (On Weight Fabric) OWF Reactive Blue 52, 0.5 g/l anionic dispersant, 75 g/l common salt, 2 g/l sodium bicarbonate, and 4 g/l soda ash. 1.0 g/l nonionic soaping agent is used for soaping off the unfixed dye. After dyeing, all samples are dried in a Kenmore dryer, steam iron pressed, and then analyzed for color with a Hunterlab D25 colorimeter at six different points on the sample, taking L, a and b spectrum measurements.
EXAMPLE 10
The following experiment was performed to illustrate that propylchlorohydrin trimethyl ammonium chloride can be incorporated into a hydrogen peroxide bleach bath for the purpose of improving the application vat dye to the cellulosic fiber bleached and treated in the bath. In this experiment, enzyme desized and 4% OWB caustic scoured Testfabrics style 428R 100% cotton fabric samples are treated in a 1% hydrogen peroxide bath at a pH of 10.8 stabilized with 0.15% Mg Cl 2 6H 2 O. 0.25% (solids basis), Primacor 5980® (Dow Adhesive Polymer Ethylene/Acrylic Acid Dispersion), 0.2% Triton non-ionic wetting agent, and 0.2% dodecylbenzenesulfonic acid, and 8 ppm ferric chloride to challenge the stabilizer system. Each fabric samples measures approximately 8 inch by 1.5 inch. Caustic scouring is done to each sample by first padding 4% OWB (on weight bath) caustic, 0.25% sodium laurel sulfate on the fabric at an 85% wet pickup. The sample is then sealed in a type 2A launderometer container and held at 100 degrees for 30 minutes. The sample is then boiled in 800 mls. deionized water, padded to minimum wet pickup and left wet until bleaching is commenced. Fabric sample No. 1 is prepared in the unaltered bleach bath described above. Fabric sample No. 2 is treated in the original bleach bath additionally containing 0.5% OWB Dow Chemical Company Quat 188 propylchlorohydrin trimethyl ammonium chloride. Fabric sample No. 3 is treated in the above described bleach bath additionally containing 1.0% OWB epoxy compound. Fabric sample No. 4 is prepared like sample No. 2 with the exception that 0.6% epoxy compound in the caustic scouring bath. In each preparation, the sample is double dipped and double padded through its bleach bath for an 85% to 90% wet pickup. The sample is sealed in a type 5A Launder-ometer container and agitated in a 100 degree C. bath for 1 hour. The bleached sample is washed in 50 to liquor to goods ratio boiling water followed with several rinses in cool deionized water. It is then padded to minimum wet pickup and dried in a Kenmore clothes dryer. The samples are then dyed using a Cotton Incorporated procedure modified slightly for Launder-ometer use. The composition of the dye bath incorporates 0.5% g/l nonionic detergent. After dyeing, all samples are dried in a Kenmore dryer, steam iron pressed, and then analyzed for color with a Hunterlab D25 colorimeter a six different points on the sample, taking L, a and b spectrum measurements.
The principles, preferred embodiments and modes of operation of the present invention have been described in the foregoing specification. The invention which is intended to be protected herein, however, is not to be construed as limited to the particular forms disclosed, since these are to be regarded as illustrative rather than restrictive. Variations and changes may be made by those skilled in the art without departing from the spirit of the invention. | In a process for treating a cellulosic fabric which includes the step of scouring and/or bleaching the improvement which comprises treating said fabric with a quaternary compound of the formula selected from the group consisting of: ##STR1## wherein R, R', R" and R"' are each lower alkyl radicals and X - is an anion prior to dyeing so as to improve its whiteness and/or dyeability. | 3 |
BACKGROUND OF THE INVENTION
1. Field of the Invention
The present invention relates to hydraulic turbines and more particularly pertains to a new hydraulic turbine assembly for deriving extra energy out of a conventional hydroelectric power generating system.
2. Description of the Prior Art
The use of hydraulic turbines is known in the prior art. More specifically, hydraulic turbines heretofore devised and utilized are known to consist basically of familiar, expected and obvious structural configurations, notwithstanding the myriad of designs encompassed by the crowded prior art which have been developed for the fulfillment of countless objectives and requirements.
Known prior art hydraulic turbines include U.S. Pat. Nos. 4,437,017; 4,963,780; 4,219,303; 4,816,697; 4,443,707 and 4,284,899.
While these devices fulfill their respective, particular objectives and requirements, the aforementioned patents do not disclose a new hydraulic turbine assembly. The inventive device includes a vertical water inlet pipe being extended into the water reservoir of a dam to deliver water to the conventional hydroelectric generating system. The vertical water inlet pipe has a water inlet point being positioned in the water reservoir to create an inlet free vortex formation. An outer housing tube having an inlet cone for collecting water from said inlet free vortex formation and an outlet draft in fluid communication with the vertical water inlet pipe to permit water to pass through the outer housing tube to the vertical water inlet pipe. A rotor and turbine assembly having a rotor unit and at least one generator unit for creating electrical energy is disposed within the outer housing tube to permit rotation of the rotor unit within the outer housing unit by water passing through the outer housing tube. Each of the generator units is operationally coupled to the rotor unit so that the rotational energy of the rotor unit is transferred by the generator units into electrical energy.
In these respects, the hydraulic turbine assembly according to the present invention substantially departs from the conventional concepts and designs of the prior art, and in so doing provides an apparatus primarily developed for the purpose of deriving extra energy out of a conventional hydroelectric power generating system.
SUMMARY OF THE INVENTION
In view of the foregoing disadvantages inherent in the known types of hydraulic turbines now present in the prior art, the present invention provides a new hydraulic turbine assembly construction wherein the same can be utilized for deriving extra energy out of a conventional hydroelectric power generating system.
The general purpose of the present invention, which will be described subsequently in greater detail, is to provide a new hydraulic turbine assembly apparatus and method which has many of the advantages of the hydraulic turbines mentioned heretofore and many novel features that result in a new hydraulic turbine assembly which is not anticipated, rendered obvious, suggested, or even implied by any of the prior art hydraulic turbines, either alone or in any combination thereof.
To attain this, the present invention generally comprises a vertical water inlet pipe being extended into the water reservoir of a dam to deliver water to the conventional hydroelectric generating system. The vertical water inlet pipe has a water inlet point being positioned in the water reservoir to create an inlet free vortex formation. An outer housing tube having an inlet cone for collecting water from said inlet free vortex formation and an outlet draft in fluid communication with the vertical water inlet pipe to permit water to pass through the outer housing tube to the vertical water inlet pipe. A rotor and turbine assembly having a rotor unit and at least one generator unit for creating electrical energy is disposed within the outer housing tube to permit rotation of the rotor unit within the outer housing unit by water passing through the outer housing tube. Each of the generator units is operationally coupled to the rotor unit so that the rotational energy of the rotor unit is transferred by the generator units into electrical energy.
There has thus been outlined, rather broadly, the more important features of the invention in order that the detailed description thereof that follows may be better understood, and in order that the present contribution to the art may be better appreciated. There are additional features of the invention that will be described hereinafter and which will form the subject matter of the claims appended hereto.
In this respect, before explaining at least one embodiment of the invention in detail, it is to be understood that the invention is not limited in its application to the details of construction and to the 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.
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.
It is therefore an object of the present invention to provide a new hydraulic turbine assembly apparatus and method which has many of the advantages of the hydraulic turbines mentioned heretofore and many novel features that result in a new hydraulic turbine assembly which is not anticipated, rendered obvious, suggested, or even implied by any of the prior art hydraulic turbines, either alone or in any combination thereof.
It is another object of the present invention to provide a new hydraulic turbine assembly which may be easily and efficiently manufactured and marketed.
It is a further object of the present invention to provide a new hydraulic turbine assembly which is of a durable and reliable construction.
An even further object of the present invention is to provide a new hydraulic turbine assembly which is susceptible of a low cost of manufacture with regard to both materials and labor, and which accordingly is then susceptible of low prices of sale to the consuming public, thereby making such hydraulic turbine assembly economically available to the buying public.
Still yet another object of the present invention is to provide a new hydraulic turbine assembly which provides in the apparatuses and methods of the prior art some of the advantages thereof, while simultaneously overcoming some of the disadvantages normally associated therewith.
Still another object of the present invention is to provide a new hydraulic turbine assembly for deriving extra energy out of a conventional hydroelectric power generating system.
Still a further object of the present invention is to allow, if required, water to be returned to the reservoir, utilizing the extra energy created, and thereby provide an alternative means of increasing the overall energy output of a conventional hydroelectric power generating system, by increasing the volume of water available to pass through that system.
Still yet a further object of the present invention is to allow, if required, any number of hydraulic turbine assemblies to be incorporated into the reservoir at various locations within the reservoir, their respective outlet pipes each ultimately joining with the main outlet pipe of the reservoir which leads to the conventional hydroelectric power generating system, thus multiplying the additional energy output of the hydraulic turbine assemblies within that system.
Yet another object of the present invention is to provide a new hydraulic turbine assembly which includes a vertical water inlet pipe being extended into the water reservoir of a dam to deliver water to the conventional hydroelectric generating system. The vertical water inlet pipe has a water inlet point being positioned in the water reservoir to create an inlet free vortex formation. An outer housing tube having an inlet cone for collecting water from said inlet free vortex formation and an outlet draft in fluid communication with the vertical water inlet pipe to permit water to pass through the outer housing tube to the vertical water inlet pipe. A rotor and turbine assembly having a rotor unit and at least one generator unit for creating electrical energy is disposed within the outer housing tube to permit rotation of the rotor unit within the outer housing unit by water passing through the outer housing tube. Each of the generator units is operationally coupled to the rotor unit so that the rotational energy of the rotor unit is transferred by the generator units into electrical energy.
Still yet another object of the present invention is to provide a new hydraulic turbine assembly that derives extra energy out of a conventional hydroelectric power generating system by incorporating a second turbine generator at the inlet from the reservoir while allowing the majority of the energy to be available to the conventional turbine arrangement of the dam.
Even still another object of the present invention is to provide a new hydraulic turbine assembly that has an inlet designed to allow a free vortex to form, the energy of which is currently lost in the form of other turbulence. The source of this energy is a combination of various parameters including initial pre-swirl in the water, the Coriolis effect from the rotation of the Earth and the shape of the reservoir.
These together with other objects of the invention, along with the various features of novelty which characterize the invention, are pointed out with particularity in the claims annexed to and forming a part of this disclosure. For a better understanding of the invention, its operating advantages and the specific objects attained by its uses, reference should be had to the accompanying drawings and descriptive matter in which there is illustrated preferred embodiments of the invention.
BRIEF DESCRIPTION OF THE DRAWINGS
The invention will be better understood and objects other than those set forth above will become apparent when consideration is given to the following detailed description thereof. Such description makes reference to the annexed drawings wherein:
FIG. 1 is a right side view of a new hydraulic turbine assembly according to the present invention.
FIG. 2 is a side view of the hydraulic turbine unit.
FIG. 3 is an exploded isometric illustration of the hydraulic turbine assembly main section.
FIG. 4 is a side view of the rotor & turbine assembly.
FIG. 5 is an exploded isometric illustration of the turbine assembly.
FIG. 6 is an exploded isometric illustration of the rotor and generator sub assembly.
FIG. 7 is a top plan view of the rotor unit.
FIG. 8 is a side view of the rotor unit taken along the line 8--8 of FIG. 7.
FIG. 9 is a side view of the rotor unit taken along the line 9--9 of FIG. 7.
DESCRIPTION OF THE PREFERRED EMBODIMENT
With reference now to the drawings, and in particular to FIGS. 1 through 9 thereof, a new hydraulic turbine assembly embodying the principles and concepts of the present invention and generally designated by the reference numeral 3 will be described.
More specifically, it will be noted that the hydraulic turbine assembly 3 comprises the vertical water inlet pipe (1), the outlet draft tube (8), and the rotor and turbine assembly (38).
As best illustrated in FIGS. I through 9, it can be shown that this hydraulic turbine assembly (3) is designed to derive extra energy out of a conventional hydroelectric power generation system by incorporating a second turbine generator at the vertical inlet from the reservoir.
The invention as shown in FIG. 1 consists of a modular designed removable electrical generation turbine unit attached to a vertically facing inlet water feed pipe that supplies water to the conventional down stream or lower electrical generation power plant.
As shown in FIG. 1, the vertical inlet pipe (1) presents itself with a flange receiving end (42) suitable for the attachment of the flange mount (30) of the hydraulic turbine unit (3) and may be fabricated from concrete, steel or other suitable materials in order to withstand the weight and torsional loading subjected by the unit.
The vertical inlet pipe's (1) horizontal positioning within the water reservoir (41) shall allow for adequate clearance from retaining or dam wall (31), base (32), water surface (33) and sides of the water reservoir (41) so as to enable the proper formation of a free inlet vortex (34) specific to the application. The water supply or flow can be slowed or stopped using a suitable form of valve or shut off gate (2) necessary for system shut down.
The flange mount (30) of the hydraulic turbine assembly (3) itself is flange mounted to the flange receiving end (42) of the water inlet pipe (1) and so can be easily disassembled and removed for repairs, maintenance or to enable the conventional hydroelectric generating system (35) to operate as previously.
The power output cable (4) is appropriately insulated and exits from the hermetically sealed generator unit (29) to the required supply feed point outside the water reservoir (41).
The height of the water inlet point (5) of the unit from the free surface of the water (33) is such as to allow for the formation of a free vortex (34) above the hydraulic turbine assembly (3) and depends on the particular application. A screened enclosure structure such as a mesh screen (6) may be required depending on the application for the prevention of material other than water from entering the system.
As depicted in FIG. 2, the hydraulic turbine assembly (3) consists of three sections the first of which is described as the inlet cone (7). Its function is to collect the inlet water and is shaped to minimize inlet hydraulic pressure losses according to the particular application as well as to locally increase water velocity entering the turbine main section (10). The inlet cone (7) can be made from concrete or steel or other suitable materials according to the specific application and must withstand the high water velocities in its proximity and also the weight of the whole of the unit for unit installation and disassembly. The inlet cone (7) is flange mounted at the flanged joint (36) to the main section (10) and can be disassembled from it.
The outlet draft tube (8) is diverging in shape and is shaped so as to reduce turbine exit water velocity and to further increase the energy potential across the turbine. Its construction is similar to that of the inlet cone (7). The outlet draft tube (8) is also flange mounted to the main section (10) at the flanged joint (43) and can also be disassembled from it.
The power outlet cable (4) exits the hydraulic turbine assembly (3) via one of the turbine support pillars (9) and may either pass through a hollow support pillar (9) from the hydraulic turbine assembly (3) or be attached along it. The exit point may also be a hermetically sealed junction box (37) where disconnection is possible separating the cable (4) from the rest of the unit.
The hydraulic turbine assembly (3) main section (10) completes the three part structure of the hydraulic turbine assembly (3) and is the working section containing the turbine rotor and electrical power generating equipment. Its outer housing tube (13) is made from similar materials to the inlet cone (7) and outlet draft (8) and mounts to each respectively at its inlet and outlet flanged joints (36, 43) mount to each respectively.
Continuing the modularity of the concept when separated from the inlet cone (7) and outlet draft (8), the main section (10) as shown in FIG. 3 can be further disassembled to reveal a top cap assembly (11) flange mounted between the main section (10) and inlet cone (7) containing the top support pillars (9) that help suspend the rotor and turbine assembly (38) in the middle of the water stream as well as the streamlined top cap (11). The purpose of the top cap assembly (11) is to minimize the hydraulic form losses of the rotor and turbine assembly (38) and does not rotate with the rotor unit (26).
The support pillars (9) are also hydrodynamically designed to minimize form drag and also do not rotate. Similarly, the lower cap assembly (12) is a structure that does not rotate but serves to support the rotor and turbine assembly (38) whilst minimizing drag. The flanged outer housing tube (13) completes the support structure for the rotor and turbine assembly (38) as well as of course containing the water.
As shown in FIG. 4, the rotor and turbine assembly (38) is supported by the upper support plate (14) and lower support plate (15) which do not rotate but serve to attach the contained unit to the top cap assembly (11) and bottom cap assembly (12) mentioned above.
The support plates (14, 15) also fix the support shaft (16) which also does not rotate thereby minimizing the actual number of components and hence weight of the parts that do rotate in the unit and mentioned later on. The actual method of fixing can be splining or keying or other suitable method to prevent the shaft (16) from rotating with respect to the fixed support plates (14, 15). The fixed support shaft (16) also carries the upper bearing assembly (17) and lower bearing assembly (18) about which the revolves the rotor (26).
The rotor unit assembly (26) may need to be sealed against water entry and for this, felt or any suitable seals may be used for the upper seal (19) and the lower seal (20). Upper retaining cap (21) and lower retaining cap (22) also serve to complete the sealing and to vertically locate the fixed support shaft (16). The rotor and generator sub-assembly (23) can be seen separated here from the upper and lower bearing assemblies (17, 18) and upper and lower support plates (14, 15).
The upper bearing plate (24) and lower bearing plate (25) are attached and rotate with the rotor (26). Their function is to support the rotor (26) in the first instance but also, in the case of the upper bearing plate (24), to transfer the rotational energy of the rotor (26) to the electrical generator unit (29) via a series of gears. The upper bearing plate (24) is itself an annular gear with internal teeth that act on the gear box (27).
As depicted in FIGS. 6 and 7, the rotor unit (26) is the main rotating element of the turbine containing three to six blades (40) depending on the application. These blades (40) are pitched at a greater angle at the tip and shallower at the hub to accommodate for differences in relative speeds between the blades (40) and the water for varying distance from the central axis of the rotor unit (26).
A gear box assembly (27) accepts the rotational energy from the upper bearing plate gear (24) and transforms the torque and speed to suitable values depending on the application feeding it to the generator units (29). The number of sets of gears (39) used depends on the number of modular generator units (29) deployed in the application. A gear carrier (28) that does not rotate and is fixed by keying or other suitable method to the central fixed support shaft (16) is used to maintain the gear box gears (39) in their relative positions and prevent them from revolving around with the upper bearing plate (24). The shape of the gear carrier (28) depends on the number of modular generator units (29) deployed in the application.
The mechanical rotational energy is finally converted to electrical energy by the use of generator units (29) that are firmly attached to flat sections of the fixed support shaft (16) and do not themselves move. The number of generator units (29) deployed depends on the particular application, the annular space considerations and the available torque generated. Each generator unit (29) is fully sealed and submersible, the output cable (4) being also fully sealed.
In use, the inlet of the hydraulic turbine assembly (3) is designed to allow a free vortex to form, the energy of which is currently lost in the form of other turbulence. The source of this energy is a combination of various parameters including initial pre-swirl in the water, the Coriolis effect from the rotation of the Earth and the shape of the water reservoir (41). The low operating head, large flow rate and significant water swirl thus lends itself to the use of an axial flow type of hydraulic turbine as in the present hydraulic turbine assembly (3).
In use, it should also be understood that this hydraulic turbine assembly (3) may be used separately from the conventional hydroelectric generating system (35) of the dam (31) as a stand alone hydroelectric generating system. That is, the hydraulic turbine assembly (3) may be used so that water passing from the hydraulic turbine assembly (3) does not have to enter the conventional hydroelectric generation system (35) of the dam or it may be used in a system that does not include the conventional hydroelectric generating system (35).
Because of the low operating hydraulic head across this hydraulic turbine assembly (3), the majority of the energy to the conventional turbine arrangement for the dam would still be available. Thus, the total energy output of the system with the added hydraulic turbine assembly (3) would then be greater than that using only the conventional turbine arrangement.
One of the greatest strengths of the hydraulic turbine assembly (3) is that by drawing upon the Coriolis effect this invention does not thereby interfere with the operation of the conventional hydraulic turbine system of the dam (31). Accordingly, this invention does not contravene the conservation of energy principle.
As to a further discussion of the manner of usage and operation of the present invention, the same should be apparent from the above description. Accordingly, no further discussion relating to the manner of usage and operation will be provided.
With respect to the above description then, it is to be realized that the optimum dimensional relationships for the parts of the invention, to include variations in size, materials, shape, form, function and manner of operation, assembly and use, are deemed readily apparent and obvious to one skilled in the art, and all equivalent relationships to those illustrated in the drawings and described in the specification are intended to be encompassed by the present invention.
Therefore, the foregoing is considered as illustrative only of the principles of the invention. Further, since numerous modifications and changes will readily occur to those skilled in the art, it is not desired to limit the invention to the exact construction and operation shown and described, and accordingly, all suitable modifications and equivalents may be resorted to, falling within the scope of the invention. | A new hydraulic turbine assembly for deriving extra energy out of a conventional hydroelectric power generating system by incorporating a second turbine generator at the inlet from the reservoir. The inventive device includes a vertical water inlet pipe being extended into the water reservoir of a dam to deliver water to the conventional hydroelectric generating system. The vertical water inlet pipe has a water inlet point being positioned in the water reservoir to create an inlet free vortex formation. An outer housing tube having an inlet cone for collecting water from said inlet free vortex formation and an outlet draft in fluid communication with the vertical water inlet pipe to permit water to pass through the outer housing tube to the vertical water inlet pipe. A rotor and turbine assembly having a rotor unit and at least one generator unit for creating electrical energy is disposed within the outer housing tube to permit rotation of the rotor unit within the outer housing unit by water passing through the outer housing tube. Each of the generator units is operationally coupled to the rotor unit so that the rotational energy of the rotor unit is transferred by the generator units into electrical energy. | 5 |
BACKGROUND
[0001] This invention relates generally to microwave and millimeter wave (mm-wave) radio frequency (RF) circuits, and more particularly to achieving broadband high isolation switch in Balanced Line Circuits.
[0002] [0002]FIG. 1 shows a balanced line. A balanced line 10 may be achieved by using two conductors 11 and in a symmetric environment. Such balanced lines can be achieved for example as in twisted pair cable or on insulating substrates. The input port 12 is composed of two terminal 12 a and 12 b . Due to symmetry, terminals 12 a and 12 b have opposing voltage V 1 and −V 1 and support equal currents 16 and 17 in opposite direction or opposing current. In a balanced line configuration because there is no other path available for the current, the forward going current has to be equal to the reverse going current at any location, for example position 18 , due to charge conservation. Moreover, voltage at any location 18 along the transmission line is also equal and opposite. If the balanced line is terminated in a balanced manner (i.e., same impedance on each line) using the output port terminal 13 a and 13 b , the output port 13 also has opposing voltages and currents, 14 and 15 , respectively, at the terminal 13 a and 13 b.
[0003] Such balanced lines are widely used in substrates where ground is not easily accessible. Examples include silicon substrates without vias, which are widely used for both mm-wave and microwave frequencies.
[0004] Prior art electronic switches in balanced lines are achieved in series 20 and shunt 30 configuration, as shown in FIG. 2 and FIG. 3, respectively.
[0005] In FIG. 2, the input lines 22 and 23 have, in series, diodes 24 and 25 , respectively. While diodes are depicted in this figure, in actual practice other devices that switch from a high impedance state (or blocking state) to a low impedance state (or transmitting state) may be used to perform the task. For example, the diodes could be replaced by a three terminal device, whose state is switched using one of the three terminals such as the base of a Bipolar Transistor, where the Emitter and Collector are the two ends of the switching device. In another configuration, the Emitter current is switched while the Base forms the input and the Collector the output. Considering FIG. 2, in the low impedance state when the diode is forward biased, the diodes 24 and 25 connect the input lines 22 and 23 to the output lines 26 and 27 , respectively. The signal is thus transmitted in high strength. The S-parameter for the forward transmission gain, S 21 , is high, being close to zero decibels (dB) S-parameters, or scattering parameters, are analogous to frequency response functions, but the terms are used at high and lower frequencies, respectively. In the other state the diodes are in the non-conducting state. In that state the signal is reflected back. Now the transmitted signal to the output lines 26 and 27 is attenuated and the S 21 transmission coefficient is low (−10's of dB), and is determined by the high impedance state. Since the high impedance is finite, a small amount of signal trickles through and is represented by δ 1 .
[0006] [0006]FIG. 3 shows a shunt mounted diode 30 in a balanced line for switch purposes. When the diode is reversed biased or is in the high impedance state, since it appears as open circuit between the lines, the signal is transmitted through or S 21 is high, i.e., close to 0 dB. In the other state, diode 33 is forward biased and is in the low impedance state. In this state, because the input balanced lines 31 and 32 are effectively shorted by the small impedance, the voltage induced at the input of the balanced line 34 and 35 is effectively small. This then has very little signal transmitted to the out balanced lines 34 and 35 .
[0007] In case of the series configuration 20 , the impedance in the high impedance state determines the isolation. Since the impedance is finite but high impedance, a signal always leaks to the output. At mm-wave, the impedance in the high conducting state is mostly capacitive and could greatly reduce the isolation (or the magnitude of minus S 21 , where S 21 is in dB). Similarly in the shunt configuration case the forward biased impedance or the low impedance state determines the isolation. Since the low impedance state has finite impedance (resistive at low frequency and reactive at mm-wave), the isolation is limited by this impedance.
SUMMARY
[0008] In an embodiment, a high isolation switch for a balanced line includes a switch connected in series between the input and output sections of each the two balanced line conductors and two switches cross connected between the input and output sections of the balanced line conductors. In an on-state, the series connected switches are in a low impedance state and the cross-connected switches are in a high impedance state. In an off-state, the series connected switches are in the high impedance state and the cross-connected switches are in the high impedance state, providing high isolation. The balanced line conductors and switches may be, e.g., diodes or bipolar junction transistors (BJTs), and may be integrated into a silicon substrate.
BRIEF DESCRIPTION OF THE DRAWINGS
[0009] [0009]FIG. 1 is a schematic diagram of a balanced line.
[0010] [0010]FIG. 2 shows a prior art implementation of a series switch in balanced configuration.
[0011] [0011]FIG. 3 shows a prior art implementation of a series switch in balanced configuration.
[0012] [0012]FIG. 4 shows a high isolation switch in balanced lines according to an implementation.
[0013] [0013]FIGS. 5A-5C show a simplified diode equivalent circuit in the forward biased state (low impedance state) and the reversed bias state (high impedance state).
[0014] [0014]FIG. 6 shows simulated S 21 in the on-state for the series mounted configuration, shunt mounted configuration and the high isolation switch.
[0015] [0015]FIG. 7 shows simulated S 21 in off-state for the series mounted configuration, shunt mounted configuration, and the high isolation switch.
[0016] [0016]FIG. 8 shows simulated S 21 in the off-state for a configuration according to an implementation with the cross diodes up to 10% smaller than the series diode.
[0017] [0017]FIG. 9 shows an alternative implementation of the high-isolation switch using bipolar junction transistors (BJTs).
DETAILED DESCRIPTION
[0018] [0018]FIG. 4 shows a high isolation switch according to an implementation. Diodes 43 and 44 are series mounted diodes connecting the input balanced lines 41 to the output balanced line 47 and input balanced line 42 to the output balanced lines 48 respectively. In addition, a set of diodes 45 and 46 are cross mounted and biased in the high impedance state in both of the states of the switch. The diode 45 connects input balanced line 41 to output balanced line 48 and diode 46 connects input balanced line 42 to output balanced line 47 respectively. The cross connection is important for high isolation.
[0019] The switch in FIG. 4 has two states. In the on-state, the diodes 43 and 44 are in a low impedance state while diodes 45 and 46 are in a high impedance state. In this state, the signal in the input balanced line is directly coupled to the output balanced through the low impedance states of 43 and 44 .
[0020] In the off-state, the diodes 43 and 44 are in a high impedance state while diodes 45 and 46 are also in a high impedance state. In this state, since the balanced lines have opposing voltages on line 41 and 42 as described in connection with FIG. 1, the opposing voltages couple to output lines 47 , 48 due to the two-diode cross-connections. Thus on line 47 a small signal (say −δ 3 ) couples from diode 43 from the input line 41 , while an opposing small signal (say +δ 3 ) couples through diode 46 from the input line 42 . Since 41 and 42 are in a balanced configuration, the voltage on each is negative of other provided that the diodes 43 , 44 , 45 , 46 have the same high impedance in the non-conducting or reversed biased state. Since the circuit is electrically symmetric, that is, line 47 couples same amount of voltage from both of the input lines 41 and 42 , exact cancellation occurs. As a result of this cancellation, isolation is theoretically infinite.
[0021] In real circuits there are number of reasons why the isolation degrades from the theoretical value. First of all, diodes are not the same due to process variance, nor is the bias exactly the same. This makes the off-state impedance different for the series and cross paths, thereby making the circuit asymmetric. Also, because of parasitic couplings, the isolation is limited by pad-to-pad and other couplings.
[0022] [0022]FIG. 5 shows a simplified equivalent circuit of a diode in the high impedance and the low impedance state. In the low impedance, or forward biased, state the diode can simply be represented by a forward bias resistance 51 . In the high impedance state, or the reverse biased state, the diode can simply be represented by a capacitor 52 . For example M/A-Com's diode MA4P165 (see http://www.macom.com/data/datasheet/pindiodeschip.pdf) has a forward bias resistance of less than 2.5-ohms at 10 mA forward bias and a capacitance of 0.05 pF at 10V reverse bias.
[0023] [0023]FIG. 6 shows a simulation of the switch in the on-state implement as shown in FIGS. 2, 3, and 4 . For the simulation of the series configuration shown in FIG. 2, the diodes 24 and 25 are replaced by 2.5-ohms. Similarly for the simulation of the shunt configuration in FIG. 3, the diode 33 is replaced by capacitance of 0.05 pF. Moreover for simulation of the high isolation switch in FIG. 4, diodes 43 and 44 are replaced by 2.5-ohm resistor to represent the forward state and diodes 45 and 46 are replaced by 0.05 pF capacitance to represent the reversed bias states, respectively. In FIG. 6, 61 represents the insertion loss for the series configuration shown in FIG. 2, 62 represents the insertion loss with shunt configuration shown in FIG. 3, while 63 represents the insertion loss with the configuration in FIG. 4. At high frequency, the insertion loss of the series mounted diode is the best and the high isolation switch of FIG. 4 is the worst.
[0024] [0024]FIG. 7 shows a simulation of the switches in FIGS. 2, 3, and 4 , respectively, in the off-state. For the simulation of the series configuration shown in FIG. 2, the diodes 24 and 25 are replaced by 0.05 pF, while for the simulation of the shunt configuration in FIG. 3, the diode 33 is replaced by resistance of 2.5-ohm, and finally for simulation of the switch in FIG. 4, the diodes 43 and 44 are replaced by 0.05 pF capacitors to represent the reverse bias state and the diodes 45 and 46 are replaced by 0.05 pF capacitance to represent the reversed bias states, respectively. Notice that diodes 45 and 46 are not switched between the on-state and the off-state. In FIG. 7, curve 71 represents the isolation with series mounted diode, curve 72 represents the isolation with shunt mounted diode, while curve 73 represents the isolation loss with the switch in FIG. 4. At high frequency the isolation of the series mounted diode is the worst and the switch in FIG. 4 is the best. Theoretically, if the diodes are exactly matched and the circuit is symmetric, the cancellation of the coupled signal to the output is infinite as shown in FIG. 7.
[0025] This tremendous increase of isolation is the desired feature of this invention. Because of the increased isolation the switch can include a larger size diode, thereby reducing the insertion loss in the on-state of the switch. Often in a circuit the loss of the switch is not important. Through this new technique, extremely high isolation is possible in a very small space, is broadband and in a single stage.
[0026] [0026]FIG. 8 provides a tolerance analysis of the isolation when the cross diodes are up to 10% lower than the series diode in capacitance. Even with 10% variance, substantial improvement in isolation is achieved. To reduce the effect of variance, the diode can be batch (or single wafer) processes and made in quad pair. Since the diodes would be close to each other and have similar variance, this diode-to-diode variance would not effect the isolation and one can expect substantial improvement in isolation.
[0027] [0027]FIG. 9 shows an implementation of a high isolation switch circuit using a three terminal device. While bipolar junction transistor (BJT) is shown here, any other three or multi-terminal device is also usable. In the figure, 91 and 92 are the input balanced line, 93 and 94 are the series mounted transistors, and 96 and 95 are the cross-coupled transistors. The transistors 95 and 96 are biased through 99 b and are always switched off, i.e., current through their collector is zero. The transistors 93 and 94 are biased through 99 a . In the off-state 93 and 94 are biased in the off-state similar to 95 and 96 , thereby the output signal at 97 and 98 are cancelled.
[0028] A number of embodiments have been described. Nevertheless, it will be understood that various modifications may be made without departing from the spirit and scope of the invention. For example, blocks in the flowcharts may be skipped or performed out of order and still produce desirable results. Accordingly, other embodiments are within the scope of the following claims. | A balanced line switching apparatus that provides high isolation at an expense of a marginal increase of loss. Practical implementation can give as much as 40 dB isolation in a single stage. | 7 |
BACKGROUND OF INVENTION
1. Field of Invention
The present invention relates to the measurement of the wavelength dispersion characteristic of devices under test (DUT) such as fiber pair, and in particular to the measurement of the wavelength dispersion characteristic by connecting separate measuring methodes on both ends of the DUT.
2. Description of the Related Art
In case of light being transmitted over a long distance, the transmission of light only through an optical fiber will involve considerable losses. Therefore, optical fiber transmission lines combined with optical amplifiers (EDFA) for amplifying optical signals are used for the optical fiber to prevent any possible losses. The optical amplifiers let light through only in one direction. Therefore, a bi-directional communication requires a cable integrating an optical fiber transmission line transmitting light in one direction and another optical fiber transmission line transmitting light in the direction opposite to the one direction. This cable is called a fiber pair.
The configuration of a fiber pair is shown in FIG. 6 ( a ). An optical fiber 112 combined with an optical amplifier 114 constitute an optical fiber transmission line 110 . The optical fiber transmission line 110 lets light through to the right. An optical fiber 122 combined with an optical amplifier 124 constitutes an optical fiber transmission line 120 . The optical fiber-transmission line 120 lets light through to the left. An optical fiber transmission line 110 and a optical fiber transmission line 120 constitutes an optical fiber pair 100 a . Incidentally, two sets of fiber pairs are called two fiber pairs as shown in FIG. 6 ( b ). Fiber pairs 100 a and 100 b constitute two fiber pairs 100 .
The configuration of the measurement system for measuring the wavelength characteristic of two fiber pairs is shown in FIG. 7 . At one end of a fiber pair 100 a , which is one of two fiber pairs 100 , a variable wavelength light source 202 is connected and at another end an O/E (optical/electric) converter 302 is connected. At one end of a fiber pair 100 b , which is one of the two fiber pairs 100 , a fixed wavelength light source 204 is connected, and at another end an O/E (optical/electric) converter 304 is connected. Incidentally, between the variable wavelength light sources 202 , 204 and single fiber pairs 100 a , 10 b , a light modulator may be installed.
To measure wavelength dispersion characteristics, the wavelength λx of the variable wavelength light source 202 is swept, while the wavelength λ0 of the fixed wavelength light source 204 is fixed. The phase difference between the output signals of the O/E converter 302 and the output signals of the O/E converter 304 is measured by the phase comparator 306 , to measure the wavelength dispersion characteristic of the two fiber pairs.
Here, in a bulk transmission line constituting a trunk line, two fiber pairs may be secured. In most lines already laid out, often only one fiber pair can be secured. Therefore, it is necessary to measure the wavelength dispersion characteristic of a single fiber pair.
SUMMARY OF INVENTION
Such a measuring method of the wavelength dispersion characteristic, however, cannot be applied to a single fiber pair. The reason is that two lines consisting of a line for letting a fixed wavelength light through and another line for letting a variable wavelength light through cannot be secured by a single fiber pair.
Further, even if such a measuring method of wavelength dispersion characteristic is applied to two fiber pairs 100 , the measurements may involve errors. In other words, due to physical quantitative variations including variations in the temperature, stress, etc. of the transmission line, the phase difference of light penetrating a fiber pair 100 a and another fiber pair 100 b may vary due to factors independent of wavelength. In such a case, the measurements may involve errors. Therefore, it is desirable that wavelength dispersion characteristics may be measured only by a single fiber pair without using two fiber pairs.
Therefore, the present invention has an object of providing an apparatus capable of measuring wavelength dispersion characteristic and other characteristics only through a single fiber pair.
According to a first embodiment, an optical characteristic measuring apparatus for measuring the characteristics of devices under test having the first optical transmission line letting light through in one direction only and the second optical transmission line letting light through only on the direction opposite to the aforementioned direction includes: a variable wavelength light source for generating a variable wavelength light, the wavelength of which is variable; a first light modulating unit for introducing into the first optical transmission line the first incident light obtained by modulating the variable wavelength light by the frequency of the electrical signal inputted; a first optical/electrical converting unit for converting by the optical/electrical conversion process the first incident light having penetrated the first optical transmission line; a fixed wavelength light source for generating a fixed wavelength light, the wavelength of which is fixed; a signal source for generating reference electrical signals of given frequencies; a second light modulating unit for injecting into the second optical transmission line the second incident light obtained by modulating the fixed wavelength light by the frequency of the reference electrical signals; and a second optical/electrical converting unit for converting by the optical/electrical conversion process the second outgoing light having penetrated the second optical transmission line; and for outputting the converted second outgoing light onto the first light modulating unit.
According to an optical characteristic measuring apparatus thus configured, once the wavelength of the fixed wavelength light is set in such a way that wavelength dispersion may be small in the second optical transmission line, the result of optical/electrical conversion of the second outgoing light produces a small phase difference than that of the second incident light. Thus, it is possible to consider that the result of optical/electrical conversion of the second outgoing light and the reference electrical signals may have the identical frequencies and phases. Thus, it is possible to consider that the first incident light may be same as the result of modulation of the variable wavelength light by the reference electrical signals. Thus, once the result of optical/electrical conversion of the first outgoing light and the reference electrical signals are obtained, the comparison of their phases can lead to the discovery of phase differences related to the first optical transmission line. And from the phase difference, wavelength dispersion characteristic and other factors can be computed.
According to a second embodiment, an optical characteristic measuring apparatus for measuring the characteristics of devices under test having the first optical transmission line for letting light through only in one direction and the second optical transmission line for letting light through only in the direction opposite to the one direction includes: a fixed wavelength light source for generating a fixed wavelength light, the wavelength of which is fixed; a first light modulating unit for introducing into the first optical transmission line the first incident light obtained by modulating the fixed wavelength light by the frequency of the electrical signals inputted; a first optical/electrical converting unit for converting by the optical/electrical conversion process the first outgoing light having penetrated the first optical transmission line; a variable wavelength light source for generating a variable wavelength light, the wavelength of which is variable; a signal source for generating reference electrical signals of given frequencies; a second light modulating unit for introducing onto the second optical transmission line the second incident light obtained by modulating the variable wavelength light by the frequency of the reference electrical signals; and a second optical/electrical converting unit for converting by the optical/electrical conversion process the second outgoing light having penetrated the second optical transmission line and for outputting the converted second outgoing light onto the first light modulating unit.
According to an optical characteristic measuring apparatus thus configured, the result of optical/electrical conversion of the second outgoing light will be electrical signals containing phase differences related to the second optical transmission line. Therefore, once the wavelength of the fixed wavelength light is set in such a way that wavelength dispersion may be small in the first optical transmission line, the first outgoing light containing phase differences related to the second optical transmission line and yet free of errors related to the first optical transmission line can be obtained. Thus, once the result of optical/electrical conversion of the first outgoing light and the reference electrical signals are obtained, the comparison of their phases can lead to the discovery of phase difference related to the second optical transmission line. And from the phase difference, wavelength dispersion characteristic and other factors can be computed.
According to a third embodiment, an optical characteristic measuring apparatus for measuring the characteristics of devices under test having the first optical transmission line letting light through only in one direction and the second optical transmission line letting light through only in the direction opposite to the one direction includes: a first variable wavelength light source for generating the first variable wavelength light, the wavelength of which is variable; a first light modulating unit for introducing onto the first optical transmission line the first incident light obtained by modulating the first variable wavelength light by the frequency of electrical signals inputted; a first optical/electrical converting unit for converting by the optical/electrical conversion process the first outgoing light having penetrated the first optical transmission line; a second variable wavelength light source for generating the second variable wavelength light, the wavelength of which is variable; a signal source for generating reference electrical signals of given frequencies; a second light modulating unit for introducing into the second optical transmission line the second incident light obtained by modulating the second variable wavelength light by the frequency of the reference electrical signals; and a second optical/electrical converting unit for converting by the optical/electrical conversion process the second outgoing light having penetrated the second optical transmission line and for outputting the converted second outgoing light onto the first light modulating unit.
According to an optical characteristic measuring apparatus thus configured, by using a first variable wavelength light source and a second variable wavelength light source, the wavelength dispersion characteristic and other factors of the first optical transmission line and the second optical transmission line can be computed.
According to a fourth embodiment, the optical characteristic measuring apparatus according to the second embodiment further includes a third optical/electrical converting unit for converting by the optical/electrical conversion process the reflected light generated when the second light modulating unit introduces the second incident light into the second optical transmission line.
According to a fifth embodiment, the optical characteristic measuring apparatus according to the first embodiment further includes: a phase comparing unit for measuring the phase difference between the electrical signals for measurement outputted by the first optical/electrical converting unit and the reference electrical signals; and a characteristic computing unit for computing the group delay characteristic or the dispersion characteristic of the devices under test by using the phase difference.
According to a sixth embodiment, the optical characteristic measuring apparatus according to the fourth embodiment further includes: a phase comparing unit for measuring the phase difference between the electrical signals for reflection measurement outputted by the third optical/electrical converting unit and the reference electrical signals; and a characteristic computing unit for computing the group delay characteristic or the dispersion characteristic of the devices under test.
According to a seventh embodiment, a light generating apparatus used in an apparatus for measuring the characteristics of devices under test having the first optical transmission line letting light through only in one direction and the second optical transmission line letting light through only on the direction opposite to the one direction includes: a variable wavelength light source for generating a variable wavelength light, the wavelength of which is variable; a first light modulating unit for introducing into the first optical transmission line the first incident light obtained by modulating the variable wavelength light by the frequency of electrical signals inputted; and a second optical/electrical converting unit for converting by the optical/electrical conversion process the second outgoing light having penetrated the second optical transmission line and for outputting the converted second outgoing light onto the first light modulating unit.
According to an eighth embodiment, an optical characteristic measuring apparatus for measuring the characteristics of devices under test having a first optical transmission line letting light through only in one direction and a second optical transmission line letting light through only in the direction opposite to the one direction includes: a first optical/electrical converting unit for converting by the optical/electrical conversion process the first incident light having penetrated the first optical transmission line; a fixed wavelength light source for generating a fixed wavelength light, the wavelength of which is fixed; a signal source for generating reference electrical signals of given frequencies; and a second light modulating unit for introducing into the second optical transmission line the second incident light obtained by modulating the fixed wavelength light by the frequency of the reference electrical signals.
According to an ninth embodiment, a light generating apparatus used in a measuring apparatus of the characteristics of devices under test having the first optical transmission line letting light through only in one direction and the second optical transmission line letting light through only in the direction opposite to the one direction includes: a fixed wavelength light source for generating a fixed wavelength light, the wavelength of which is fixed; a first light modulating unit for introducing into the first optical transmission line the first incident light obtained by modulating the fixed wavelength light by the frequency of electrical signals inputted; and a second optical/electrical converting unit for converting by the optical/electrical conversion process the second outgoing light having penetrated the second optical transmission line and for outputting the converted second outgoing light onto the first light modulating unit.
According to a tenth embodiment, an optical characteristic measuring apparatus for measuring the characteristics of devices under test having the first optical transmission line letting light through only in one direction and the second optical transmission line letting light through only in the direction opposite to the one direction includes: a first optical/electrical converting unit for converting by the optical/electrical conversion process the first outgoing light having penetrated the first optical transmission line; a variable wavelength light source for generating a variable wavelength light, the wavelength of which is variable; a signal source for generating reference electrical signals of given frequencies; a second light modulating unit for introducing into the second optical transmission line the second incident light obtained by modulating the variable wavelength light by the frequency of the reference electrical signals.
According to an eleventh embodiment, a light generating apparatus used in a measuring apparatus of the characteristics of devices under test having the first optical transmission line letting light through only in one direction and the second optical transmission line letting light through only in the direction opposite to the one direction includes: a first variable wavelength light source for generating the first variable wavelength light, the wavelength of which is variable; a first light modulating unit for introducing into the first optical transmission line the first incident light obtained by modulating the first variable wavelength light by the frequency of electrical signals inputted; and a second optical/electrical converting unit for converting by the optical/electrical conversion process the second outgoing light having penetrated the second optical transmission line and for outputting the converted second outgoing light onto the first light modulating unit.
According to a twelfth embodiment, an optical characteristic measuring apparatus for measuring the characteristics of devices under test having the first optical transmission line letting light through only in one direction and the second optical transmission line letting light through only in the direction opposite to the one direction includes: a first optical/electrical converting unit for converting by the optical/electrical conversion process the first outgoing light having penetrated the first optical transmission line; a second variable wavelength light source for generating the second variable wavelength light, the wavelength of which is variable; a signal source for generating reference electrical signals of given frequencies; a second light modulating unit for introducing into the second optical transmission line the second incident light obtained by modulating the second variable wavelength light by the frequency of the reference electrical signals.
According to a thirteenth embodiment, an optical characteristic measuring method for measuring the characteristics of devices under test having the first optical transmission line letting light through in one direction only and the second optical transmission line letting light through only on the direction opposite to the aforementioned direction includes: a variable wavelength light generating step for generating a variable wavelength light, the wavelength of which is variable; a first light modulating step for introducing into the first optical transmission line the first incident light obtained by modulating the variable wavelength light by the frequency of the electrical signal inputted; a first optical/electrical converting step for converting by the optical/electrical conversion process the first incident light having penetrated the first optical transmission line; a fixed wavelength light generating step for generating a fixed wavelength light, the wavelength of which is fixed; a signal generating step for generating reference electrical signals of given frequencies; a second light modulating step for injecting into the second optical transmission line the second incident light obtained by modulating the fixed wavelength light by the frequency of the reference electrical signals; and a second optical/electrical converting step for converting by the optical/electrical conversion process the second outgoing light having penetrated the second optical transmission line; and for outputting the converted second outgoing light onto the first light modulating step.
According to a fourteenth embodiment, an optical characteristic measuring method for measuring the characteristics of devices under test having the first optical transmission line for letting light through only in one direction and the second optical transmission line for letting light through only in the direction opposite to the one direction includes: a fixed wavelength light generating step for generating a fixed wavelength light, the wavelength of which is fixed; a first light modulating step for introducing into the first optical transmission line the first incident light obtained by modulating the fixed wavelength light by the frequency of the electrical signals inputted; a first optical/electrical converting step for converting by the optical/electrical conversion process the first outgoing light having penetrated the first optical transmission line; a variable wavelength light generating step for generating a variable wavelength light, the wavelength of which is variable; a signal generating step for generating reference electrical signals of given frequencies; a second light modulating step for introducing onto the second optical transmission line the second incident light obtained by modulating the variable wavelength light by the frequency of the reference electrical signals; and a second optical/electrical converting step for converting by the optical/electrical conversion process the second outgoing light having penetrated the second optical transmission line and for outputting the converted second outgoing light onto the first light modulating step.
According to a fifteenth embodiment, an optical characteristic measuring method for measuring the characteristics of devices under test having the first optical transmission line letting light through only in one direction and the second optical transmission line letting light through only in the direction opposite to the one direction includes: a first variable wavelength light generating step for generating the first variable wavelength light, the wavelength of which is variable; a first light modulating step for introducing onto the first optical transmission line the first incident light obtained by modulating the first variable wavelength light by the frequency of electrical signals inputted; a first optical/electrical converting step for converting by the optical/electrical conversion process the first outgoing light having penetrated the first optical transmission line; a second variable wavelength light generating step for generating the second variable wavelength light, the wavelength of which is variable; a signal generating step for generating reference electrical signals of given frequencies; a second light modulating step for introducing into the second optical transmission line the second incident light obtained by modulating the second variable wavelength light by the frequency of the reference electrical signals; and a second optical/electrical converting step for converting by the optical/electrical conversion process the second outgoing light having penetrated the second optical transmission line and for outputting the converted second outgoing light onto the first light modulating step.
According to a sixteenth embodiment, a light generating method used in a method for measuring the characteristics of devices under test having the first optical transmission line letting light through only in one direction and the second optical transmission line letting light through only on the direction opposite to the one direction includes: a variable wavelength light generating step for generating a variable wavelength light, the wavelength of which is variable; a first light modulating step for introducing into the first optical transmission line the first incident light obtained by modulating the variable wavelength light by the frequency of electrical signals inputted; and a second optical/electrical converting step for converting by the optical/electrical conversion process the second outgoing light having penetrated the second optical transmission line and for outputting the converted second outgoing light onto the first light modulating step.
According to a seventeenth embodiment, an optical characteristic measuring method for measuring the characteristics of devices under test having a first optical transmission line letting light through only in one direction and a second optical transmission line letting light through only in the direction opposite to the one direction includes: a first optical/electrical converting step for converting by the optical/electrical conversion process the first incident light having penetrated the first optical transmission line; a fixed wavelength light generating step for generating a fixed wavelength light, the wavelength of which is fixed; a signal generating step for generating reference electrical signals of given frequencies; and a second light modulating step for introducing into the second optical transmission line the second incident light obtained by modulating the fixed wavelength light by the frequency of the reference electrical signals.
According to a eighteenth embodiment, a light generating method used in a measuring method of the characteristics of devices under test having the first optical transmission line letting light through only in one direction and the second optical transmission line letting light through only in the direction opposite to the one direction includes: a fixed wavelength light generating step for generating a fixed wavelength light, the wavelength of which is fixed; a first light modulating step for introducing into the first optical transmission line the first incident light obtained by modulating the fixed wavelength light by the frequency of electrical signals inputted; and a second optical/electrical converting step for converting by the optical/electrical conversion process the second outgoing light having penetrated the second optical transmission line and for outputting the converted second outgoing light onto the first light modulating step.
According to a nineteenth embodiment, an optical characteristic measuring method for measuring the characteristics of devices under test having the first optical transmission line letting light through only in one direction and the second optical transmission line letting light through only in the direction opposite to the one direction includes: a first optical/electrical converting step for converting by the optical/electrical conversion process the first outgoing light having penetrated the first optical transmission line; a variable wavelength light generating step for generating a variable wavelength light, the wavelength of which is variable; a signal generating step for generating reference electrical signals of given frequencies; a second light modulating step for introducing into the second optical transmission line the second incident light obtained by modulating the variable wavelength light by the frequency of the reference electrical signals.
According to a twentieth embodiment, a light generating method used in a measuring method of the characteristics of devices under test having the first optical transmission line letting light through only in one direction and the second optical transmission line letting light through only in the direction opposite to the one direction includes: a first variable wavelength light generating step for generating the first variable wavelength light, the wavelength of which is variable; a first light modulating step for introducing into the first optical transmission line the first incident light obtained by modulating the first variable wavelength light by the frequency of electrical signals inputted; and a second optical/electrical converting step for converting by the optical/electrical conversion process the second outgoing light having penetrated the second optical transmission line and for outputting the converted second outgoing light onto the first light modulating step.
A twenty-first embodiment includes an optical characteristic measuring method for measuring the characteristics of devices under test having the first optical transmission line letting light through only in one direction and the second optical transmission line letting light through only in the direction opposite to the one direction including: a first optical/electrical converting step for converting by the optical/electrical conversion process the first outgoing light having penetrated the first optical transmission line; a second variable wavelength light generating step for generating the second variable wavelength light, the wavelength of which is variable; a signal generating step for generating reference electrical signals of given frequencies; a second light modulating step for introducing into the second optical transmission line the second incident light obtained by modulating the second variable wavelength light by the frequency of the reference electrical signals.
A twenty-second embodiment includes a computer-readable medium having a program of instructions for execution by the computer to perform an optical characteristic measuring process for measuring the characteristics of devices under test having the first optical transmission line letting light through in one direction only and the second optical transmission line letting light through only on the direction opposite to the aforementioned direction, the optical characteristic measuring process including: a variable wavelength light generating processing for generating a variable wavelength light, the wavelength of which is variable; a first light modulating processing for introducing into the first optical transmission line the first incident light obtained by modulating the variable wavelength light by the frequency of the electrical signal inputted; a first optical/electrical converting processing for converting by the optical/electrical conversion process the first incident light having penetrated the first optical transmission line; a fixed wavelength light generating processing for generating a fixed wavelength light, the wavelength of which is fixed; a signal generating processing for generating reference electrical signals of given frequencies; a second light modulating processing for injecting into the second optical transmission line the second incident light obtained by modulating the fixed wavelength light by the frequency of the reference electrical signals; and a second optical/electrical converting processing for converting by the optical/electrical conversion process the second outgoing light having penetrated the second optical transmission line; and for outputting the converted second outgoing light onto the first light modulating processing.
A twenty-third embodiment includes a computer-readable medium having a program of instructions for execution by the computer to perform an optical characteristic measuring process for measuring the characteristics of devices under test having the first optical transmission line for letting light through only in one direction and the second optical transmission line for letting light through only in the direction opposite to the one direction, the optical characteristic measuring process including: a fixed wavelength light generating processing for generating a fixed wavelength light, the wavelength of which is fixed; a first light modulating processing for introducing into the first optical transmission line the first incident light obtained by modulating the fixed wavelength light by the frequency of the electrical signals inputted; a first optical/electrical converting processing for converting by the optical/electrical conversion process the first outgoing light having penetrated the first optical transmission line; a variable wavelength light generating processing for generating a variable wavelength light, the wavelength of which is variable; a signal generating processing for generating reference electrical signals of given frequencies; a second light modulating processing for introducing onto the second optical transmission line the second incident light obtained by modulating the variable wavelength light by the frequency of the reference electrical signals; and a second optical/electrical converting processing for converting by the optical/electrical conversion process the second outgoing light having penetrated the second optical transmission line and for outputting the converted second outgoing light onto the first light modulating processing.
A twenty-fourth embodiment includes a computer-readable medium having a program of instructions for execution by the computer to perform an optical characteristic measuring process for measuring the characteristics of devices under test having the first optical transmission line letting light through only in one direction and the second optical transmission line letting light through only in the direction opposite to the one direction, the optical characteristic measuring process including: a first variable wavelength light generating processing for generating the first variable wavelength light, the wavelength of which is variable; a first light modulating processing for introducing onto the first optical transmission line the first incident light obtained by modulating the first variable wavelength light by the frequency of electrical signals inputted; a first optical/electrical converting processing for converting by the optical/electrical conversion process the first outgoing light having penetrated the first optical transmission line; a second variable wavelength light generating processing for generating the second variable wavelength light, the wavelength of which is variable; a signal generating processing for generating reference electrical signals of given frequencies; a second light modulating processing for introducing into the second optical transmission line the second incident light obtained by modulating the second variable wavelength light by the frequency of the reference electrical signals; and a second optical/electrical converting processing for converting by the optical/electrical conversion process the second outgoing light having penetrated the second optical transmission line and for outputting the converted second outgoing light onto the first light modulating processing.
A twenty-fifth embodiment includes a computer-readable medium having a program of instructions for execution by the computer to perform a light generating process used in a process for measuring the characteristics of devices under test having the first optical transmission line letting light through only in one direction and the second optical transmission line letting light through only on the direction opposite to the one direction, the light generating process including: a variable wavelength light generating processing for generating a variable wavelength light, the wavelength of which is variable; a first light modulating processing for introducing into the first optical transmission line the first incident light obtained by modulating the variable wavelength light by the frequency of electrical signals inputted; and a second optical/electrical converting processing for converting by the optical/electrical conversion process the second outgoing light having penetrated the second optical transmission line and for outputting the converted second outgoing light onto the first light modulating processing.
A twenty-sixth embodiment includes a computer-readable medium having a program of instructions for execution by the computer to perform an optical characteristic measuring process for measuring the characteristics of devices under test having a first optical transmission line letting light through only in one direction and a second optical transmission line letting light through only in the direction opposite to the one direction, the optical characteristic measuring process including: a first optical/electrical converting processing for converting by the optical/electrical conversion process the first incident light having penetrated the first optical transmission line; a fixed wavelength light generating processing for generating a fixed wavelength light, the wavelength of which is fixed; a signal generating processing for generating reference electrical signals of given frequencies; and a second light modulating processing for introducing into the second optical transmission line the second incident light obtained by modulating the fixed wavelength light by the frequency of the reference electrical signals.
A twenty-seventh embodiment includes a computer-readable medium having a program of instructions for execution by the computer to perform a light generating process used in a measuring process of the characteristics of devices under test having the first optical transmission line letting light through only in one direction and the second optical transmission line letting light through only in the direction opposite to the one direction, the light generating process including: a fixed wavelength light generating processing for generating a fixed wavelength light, the wavelength of which is fixed; a first light modulating processing for introducing into the first optical transmission line the first incident light obtained by modulating the fixed wavelength light by the frequency of electrical signals inputted; and a second optical/electrical converting processing for converting by the optical/electrical conversion process the second outgoing light having penetrated the second optical transmission line and for outputting the converted second outgoing light onto the first light modulating processing.
A twenty-eight embodiment includes a computer-readable medium having a program of instructions for execution by the computer to perform an optical characteristic measuring process for measuring the characteristics of devices under test having the first optical transmission line letting light through only in one direction and the second optical transmission line letting light through only in the direction opposite to the one direction, the optical characteristic measuring process including: a first optical/electrical converting processing for converting by the optical/electrical conversion process the first outgoing light having penetrated the first optical transmission line; a variable wavelength light generating processing for generating a variable wavelength light, the wavelength of which is variable; a signal generating processing for generating reference electrical signals of given frequencies; a second light modulating processing for introducing into the second optical transmission line the second incident light obtained by modulating the variable wavelength light by the frequency of the reference electrical signals.
A twenty-ninth embodiment includes a computer-readable medium having a program of instructions for execution by the computer to perform a light generating process used in a measuring process of the characteristics of devices under test having the first optical transmission line letting light through only in one direction and the second optical transmission line letting light through only in the direction opposite to the one direction, the light generating process including: a first variable wavelength light generating processing for generating the first variable wavelength light, the wavelength of which is variable; a first light modulating processing for introducing into the first optical transmission line the first incident light obtained by modulating the first variable wavelength light by the frequency of electrical signals inputted; and a second optical/electrical converting processing for converting by the optical/electrical conversion process the second outgoing light having penetrated the second optical transmission line and for outputting the converted second outgoing light onto the first light modulating processing.
A thirtieth embodiment includes a computer-readable medium having a program of instructions for execution by the computer to perform an optical characteristic measuring process for measuring the characteristics of devices under test having the first optical transmission line letting light through only in one direction and the second optical transmission line letting light through only in the direction opposite to the one direction, the optical characteristic measuring process including: a first optical/electrical converting processing for converting by the optical/electrical conversion process the first outgoing light having penetrated the first optical transmission line; a second variable wavelength light generating processing for generating the second variable wavelength light, the wavelength of which is variable; a signal generating processing for generating reference electrical signals of given frequencies; a second light modulating processing for introducing into the second optical transmission line the second incident light obtained by modulating the second variable wavelength light by the frequency of the reference electrical signals.
BRIEF DESCRIPTION OF THE DRAWINGS
FIG. 1 is a block diagram showing the configuration of an optical characteristic measuring apparatus related to the first preferred embodiment of the present invention.
FIG. 2 is a flowchart showing the operation of the first preferred embodiment of the present invention.
FIG. 3 is a block diagram showing the configuration of an optical characteristic measuring apparatus related to the second and third preferred embodiments of the present invention.
FIG. 4 is a flowchart showing the operation of the second preferred embodiment of the present invention.
FIG. 5 is a flowchart showing the operation of the third preferred embodiment of the present invention.
FIGS. 6 ( a ) and 6 ( b ) are illustrations showing the structure of a fiber pair according to the prior art.
FIG. 7 is an illustration showing the configuration of the measuring system used to measure the wavelength dispersion characteristic of two fiber pairs according to the prior art.
DESCRIPTION OF THE PREFERRED EMBODIMENTS
The preferred embodiments of the present invention are described below with reference to the drawings.
The First Preferred Embodiment
FIG. 1 is a block diagram showing the configuration of an optical characteristic measuring apparatus related to the first preferred embodiment of the present invention. The optical characteristic measuring apparatus related to the first preferred embodiment includes a light source system 10 connected to an end of a fiber pair 30 and a characteristic measuring system 20 connected to another end of the fiber pair 30 .
A fiber pair 30 includes a first optical fiber transmission line 32 and a second optical fiber transmission line 34 . The optical fiber transmission line 32 includes an optical fiber 32 a and an optical amplifier 32 b that amplifies light and is connected to the midway of the optical fiber 32 a . The optical fiber transmission line 32 lets light through to the right. The optical fiber transmission line 34 includes an optical fiber 34 a and an optical amplifier 34 b that amplifies light and is connected to the midway of the optical fiber 34 a . The optical fiber transmission line 34 lets light through to the left.
In the first preferred embodiment, the measurement of the first optical fiber transmission line 32 is assumed, and the light source system 10 is connected to the input (left) side of the first optical fiber transmission line 32 and the characteristic measuring system 20 is connected to the output (right) side.
The light source system 10 includes a variable wavelength light source 12 , a first light modulator 15 , a second optical/electrical converter 16 and an amplifier 18 . The variable wavelength light source 12 generates a variable wavelength light, the wavelength of which is variable. The variable wavelength light source 12 can sweep the wavelength λx of the variable wavelength light. The first light modulator 15 modulates the variable wavelength light by the frequency of electrical signals outputted by the second optical/electrical converter 16 . The first light modulator 15 normally contains lithium niobate (LN), but it can dispense with LN provided that it can modulate. The light outputted by the first light modulator (the first incident light) is inputted into the first optical fiber transmission line 32 . The second optical/electrical converter 16 converts by the optical/electrical conversion process the second outgoing light outputted from the second optical fiber transmission line 34 . The amplifier 18 amplifies the electrical signals outputted by the second optical/electrical converter 16 and inputs them into the first light modulator 15 .
The first incident light inputted into the first optical fiber transmission line 32 penetrates the first optical fiber transmission line 32 . The light having penetrated the first optical fiber transmission line 32 is called as the first outgoing light.
The characteristic measuring system 20 includes a fixed wavelength light source 21 , a first optical/electrical converter 22 , a second light modulator 23 , an amplifier 24 , a power source (signal source) 25 , a phase comparator 26 and a characteristic computing section 28 .
The fixed wavelength light source 21 generates a fixed wavelength light, the wavelength of which is fixed. It is desirable to fix the wavelength of the fixed wavelength light at a wavelength λ0 at which the wavelength dispersion will be reduced to the minimum in the second optical fiber transmission line 34 .
The first optical/electrical converter 22 converts the first outgoing light by the optical/electrical conversion process. The power source (signal source) 25 generates electrical signals of a frequency fm (reference electrical signals). The second light modulator 23 modulates the fixed wavelength light by the frequency fm of the electrical signals outputted by the power source (signals source) 25 . The second light modulator 23 includes lithium niobate (LN). The light outputted by the second light modulator 23 (the second incident light) is inputted into the second optical fiber transmission line 34 . Incidentally, the second incident light penetrates the second optical fiber transmission line 34 . The light having penetrated the second optical fiber transmission line 34 is called as the second outgoing light. The amplifier 24 amplifies the output of the first optical/electrical converter 22 .
The phase comparator 26 receives the electrical signals generated by the power source (signal source) 25 at a terminal Ref_In and the electrical signals outputted by the amplifier 24 at a terminal Prob_In. The phase comparator 26 takes the electrical signals received at the terminal Ref_In as a reference for computing the phase of the electrical signals received at the terminal Prob_In.
The characteristic computing section 28 records the phases measured by the phase comparator 26 and computes the group delay characteristic and the wavelength dispersion characteristic of the first optical fiber transmission line 32 based on the phases recorded. The group delay characteristic can be computed from the relationship between the phases measured by the phase comparator 26 and the modulation frequency fm. The wavelength dispersion characteristic can be computed by differentiating the group delay characteristic by the wavelength.
And now, the operation of the first preferred embodiment of the present invention will be described with reference to the flowchart in FIG. 2 . On the left side the operation of the characteristic measuring system 20 is shown, and on the right side the operation of the light source system 10 is shown. Referring to the left side to begin with, the fixed wavelength light source 21 generates a fixed wavelength light (λ=λ0) (S 20 ). Then, the fixed wavelength light is modulated by the frequency fm of the reference electrical signals generated by the power source (signal source) (S 22 ). And the process returns to the generation of the fixed wavelength light source (S 20 ).
The fixed wavelength light modulated by the frequency fm is the second incident light. The second incident light penetrates the second optical fiber transmission line 34 and is inputted into the light source system 10 as the second outgoing light.
At this point, let us refer to the right side of FIG. 2 . The wavelength λx of the variable wavelength light is changed (S 10 ). Then, the variable wavelength light source 12 generates a variable wavelength light (λ=λx) (S 12 ). The second outgoing light is converted by the optical/electrical conversion process by the second optical/electrical converter 16 (S 14 ).
Here, the wavelength λ0 of the fixed wavelength light is set in such a way that the wavelength dispersion may be reduced to the minimum in the second optical fiber transmission line 34 . Therefore, the result of the optical/electrical conversion of the second outgoing light has a smaller phase difference than that of the second incident light. Thus, the result of the optical/electrical conversion of the second outgoing light and the reference electrical signals can be considered to have the identical frequencies and phases.
And the output of the second optical/electrical converter 16 is amplified by the amplifier 18 (S 16 ). Then, the variable wavelength light is modulated by the first light modulator 15 by the frequency of the electrical signals outputted by the second optical/electrical converter 16 (S 18 ). The frequency of the electrical signals outputted by the second optical/electrical converter 16 can be considered to be equal to the frequency fm of the reference electrical signals. In the meanwhile, the light modulated by the first light modulator 15 (the first incident light) is inputted into the first optical fiber transmission line 32 .
And now, the process returns to the change (sweep) of the wavelength λx of the variable wavelength light (S 10 ). And the operation is terminated by switching off the power at any time (S 19 ).
Then, let us refer to the left of FIG. 2 . The first incident light penetrates the first optical fiber transmission line 32 and becomes the first outgoing light. The first outgoing light is converted by the optical/electrical conversion process by the first optical/electrical converter 22 (S 24 ). The electrical signals outputted by the first optical/electrical converter 22 is amplified by the amplifier 24 (S 26 ). Then, the phase comparator 26 receives the reference electrical signals generated by the power source (signal source) 25 at its terminal Ref_In and the electrical signals for measurement outputted by the amplifier 24 at its terminal Prob_In. The phase comparator 26 takes the electrical signals received at the terminal Ref_In as a reference for computing the phase of the electrical signals received at the terminal Prob_In (S 28 ). And the phases measured are recorded at the characteristic computing section 28 .
And the phases of the electrical signals for measurement received at the terminal Prob_In are affected by wavelength dispersion by the first optical fiber transmission line 32 . But, the phase of the reference electrical signals received at the terminal Ref_In are not affected by the wavelength dispersion by the first optical fiber transmission line 32 . Thus, the measurement of the phases of the electrical signals for measurement received at the terminal Prob_In by taking the reference electrical signals received at the term Ref_In as references enables to compute the characteristics of the first optical fiber transmission line 32 .
When the light source system 10 stops operating, the characteristic computing section 28 computes the group delay characteristic and the wavelength dispersion characteristic of the first optical fiber transmission line 32 (S 29 ). The group delay characteristic can be computed from the relationship between the phases measured by the phase comparator 26 and the modulation frequency fm. The wavelength dispersion characteristic can be computed by differentiating the group delay characteristic by the wavelength.
According to the first preferred embodiment, it is possible to measure the wavelength dispersion of the first optical fiber transmission line 32 even if only one fiber pair can be secured.
The Second Preferred Embodiment
The optical characteristic measuring apparatus related to the second preferred embodiment is different from the first preferred embodiment in that the characteristic measuring system 20 has a variable wavelength light source and that the characteristic measuring system 20 converts by the optical/electrical conversion process and amplifies the reverberation of the second incident light and compares the phases with those of the reference electrical signals.
FIG. 3 is a block diagram showing the summarized configuration of an optical characteristic measuring apparatus related to the second preferred embodiment. Hereafter, the portions similar to the first preferred embodiment will be marked by the codes of similarity and their descriptions will be omitted.
The light source system 10 includes a fixed wavelength light source 11 , a first light modulator 15 , a second optical/electrical converter 16 and an amplifier 18 . The fixed wavelength light source 11 generates a fixed wavelength light, the wavelength of which is fixed. It is preferable to set the wavelength of the fixed wavelength light at a wavelength λ0 at which the wavelength dispersion will be reduced to the minimum in the first optical fiber transmission line 32 .
The characteristic measuring system 20 includes a variable wavelength light source 29 , a first optical/electrical converter 22 a , a third optical/electrical converter 22 b , a second light modulator 23 , amplifiers 24 a and b , a power source (signal source) 25 , a phase comparator 26 and a characteristic computing section 28 .
The variable wavelength light source 29 generates a variable wavelength light, the wavelength of which is variable. The variable wavelength light source 21 can sweep the wavelength λy of the variable wavelength light. The third optical/electrical converter 22 b converts by the optical/electrical conversion process the reverberations of the second incident light. The amplifier 24 b amplifies the electrical signals outputted by the third optical/electrical converter 22 b.
The phase comparator 26 receives the electrical signals generated by the power source (signal source) 25 at a terminal Ref_In, the electrical signals outputted by the amplifier 24 a at a terminal Prob_In 1 and the electrical signals for the measurement of reverberations outputted by the amplifier 24 b at a terminal Prob_In 2 . The phase comparator 26 takes the electrical signals received at the terminal Ref_In as a reference for computing the phase of the electrical signals received at the terminal Prob_In 1 and the terminal Prob_In 2 .
The operation of the second preferred embodiment will be described with reference to the flowchart in FIG. 4 . On the left side the operation of the characteristic measuring system 20 is shown, while on the right side the operation of the light source system 10 is shown. Let us refer to the left side to begin with. The wavelength λy of the variable wavelength light is changed (S 20 ). Then, the variable wavelength light source 12 generates a variable wavelength light (λ=λy) (S 21 ). Then, the variable wavelength light is modulated by the frequency fm of the reference electrical signals generated by the power source (signal source) (S 22 ). And then the process returns to the generation of the variable wavelength light (S 20 ).
The fixed wavelength light modulated by the frequency fm is the second incident light. The second incident light penetrates the second optical fiber transmission line 34 and is inputted into the light source system 10 as the second outgoing light.
At this point, let us refer to the right side of FIG. 4 . To begin with, the fixed wavelength light source 21 generates a fixed wavelength light (λ=λ0) (S 10 ). The second outgoing light is converted by the optical/electrical conversion process by the second optical/electrical converter 16 (S 14 ).
Here, the result of optical/electrical conversion of the second outgoing light is affected by the wavelength dispersion of the second optical fiber transmission line 34 .
And the output of the second optical/electrical converter 16 will be amplified (S 16 ). Then, the variable wavelength light will be modulated by the first optical/electrical converter 15 by the frequency of the electrical signals outputted by the second optical/electrical converter 16 (S 18 ). In the meanwhile, the light modulated by the first light modulator 15 (the first incident light) will be injected into the first optical fiber transmission line 32 .
Here, the wavelength λ0 of the fixed wavelength light is set in such a way that the wavelength dispersion may be reduced to the minimum in the first optical fiber transmission line 32 . Thus, the result of the optical/electrical conversion of the first outgoing light is not affected by the wavelength dispersion of the first optical fiber transmission line 32 and is affected only by the wavelength dispersion of the second optical fiber transmission line 34 .
And the process returns to the generation of the fixed wavelength light (S 10 ). In the meanwhile, the whole operation is terminated by switching off the power at any time (S 19 ).
Then, let us refer to the left of FIG. 4 . The first incident light penetrates the first optical fiber transmission line 32 and becomes the first outgoing light. The first outgoing light is converted by the optical/electrical conversion process by the first optical/electrical converter 22 a (S 24 ). And the third optical/electrical converter 22 b converts by the optical/electrical conversion process the reverberations of the second incident light (S 24 ). Then, the electrical signals outputted by the first optical/electrical converter 22 a and the third optical/electrical converter 22 b are respectively amplified by the amplifiers 24 a and b (S 26 ). Then, the phase comparator 26 receives the reference electrical signals generated by the power source (signal source) 25 at its terminal Ref_In, the electrical signals for measurement outputted by the amplifier 24 a at its terminal Prob_In 1 and the electrical signals for measurement of reverberations outputted by the amplifier 24 b at its terminal Prob_In 2 . The phase comparator 26 takes the electrical signals received at the terminal Ref_In as a reference for computing the phase of the electrical signals received at the terminals Prob_In 1 and Prob_In 2 (S 28 ). And the phases measured are recorded at the characteristic computing section 28 .
And the phases of the electrical signals received at the terminals Prob_In 1 and Prob_In 2 are affected by wavelength dispersion by the second optical fiber transmission line 34 . But, the phase of the reference electrical signals received at the terminal Ref_In is not affected by wavelength dispersion by the second optical fiber transmission line 34 . Thus, the measurement of the phases of the electrical signals received at the terminals Prob_In 1 and Prob_In 2 by taking the reference electrical signals received at the term Ref_In as references enables to compute the characteristics of the second optical fiber transmission line 34 .
When the light source system 10 stops operating, the characteristic computing section 28 computes the group delay characteristic and the wavelength dispersion characteristic of the first optical fiber transmission line 32 (S 29 ). The group delay characteristic can be computed from the relationship between the phases measured by the phase comparator 26 and the modulation frequency fm. The wavelength dispersion characteristic can be computed by differentiating the group delay characteristic by the wavelength.
According to the second preferred embodiment, it is possible to measure the wavelength dispersion of the second optical fiber transmission line 34 even if only one fiber pair can be secured.
The Third Preferred Embodiment
The optical characteristic measuring apparatus related to the third preferred embodiment is different from the second preferred embodiment in that the light source system 10 has a variable wavelength light source.
The configuration of the third preferred embodiment is described with reference to FIG. 3 . The light source system 10 includes a variable wavelength light source 12 , a first light modulator 15 , a second optical/electrical converter 16 and an amplifier 18 . The first variable wavelength light source 12 generates the first variable wavelength light, the wavelength of which is variable. The first variable wavelength light source 12 enables to sweep the wavelength λx of the first variable wavelength light. The configuration of other parts is similar to that of the second preferred embodiment. Also the configuration of the characteristic measuring system 20 is similar to that of the second preferred embodiment. However, the variable wavelength light source 21 in the second preferred embodiment is replaced by the second variable wavelength light source 21 in the third preferred embodiment.
The operation of the third preferred embodiment will be described with reference to the flowchart in FIG. 5 . On the left side the operation of the characteristic measuring system 20 is shown, while on the right side the operation of the light source system 10 is shown. Let us refer to the left side to begin with. The wavelength λy of the second variable wavelength light is changed (S 20 ). Then, the variable wavelength light source 12 generates the second variable wavelength light (λ=λy) (S 21 ). Then, the second variable wavelength light is modulated by the frequency fm of the reference electrical signals generated by the power source (signal source) (S 22 ). And then the process returns to the generation of the second variable wavelength light (S 20 ).
The fixed wavelength light modulated by the frequency fm is the second incident light. The second incident light penetrates the second optical fiber transmission line 34 and is inputted into the light source system 10 as the second outgoing light.
At this point, let us refer to the right side of FIG. 5 . The wavelength λx of the first variable wavelength light is changed (S 10 ). Incidentally, the change (sweep) of λy and that of λy will be synchronized. Then, the first variable wavelength light source 12 generates the first variable wavelength light (λ=λx) (S 12 ). The second outgoing light is converted by the optical/electrical conversion process by the second optical/electrical converter 16 (S 14 ).
And the output of the second optical/electrical converter 16 will be amplified (S 16 ). Then, the first variable wavelength light will be modulated by the first light modulator 15 by the frequency of the electrical signals outputted by the second optical/electrical converter 16 (S 18 ). In the meanwhile, the light modulated by the first light modulator 15 (the first incident light) will be inputted into the first optical fiber transmission line 32 .
And the process returns to the generation of the first variable wavelength light (S 10 ). In the meanwhile, the whole operation is terminated by switching off the power at any time (S 19 ).
Then, let us refer to the left of FIG. 5 . The first incident light penetrates the first optical fiber transmission line 32 and becomes the first outgoing light. The first outgoing light is converted by the optical/electrical conversion process by the first optical/electrical converter 22 a (S 24 ). And the third optical/electrical converter 22 b converts by the optical/electrical conversion process the reverberations of the second incident light (S 24 ). Then, the electrical signals outputted by the first optical/electrical converter 22 a and the third optical/electrical converter 22 b are amplified by the amplifiers 24 a and b (S 26 ). Then, the phase comparator 26 receives the reference electrical signals generated by the power source (signal source) 25 at its terminal Ref_In, the electrical signals for measurement outputted by the amplifier 24 a at its terminal Prob_In 1 and the electrical signals for measurement of reverberations outputted by the amplifier 24 b at its terminal Prob_In 2 . The phase comparator 26 takes the electrical signals received at the terminal Ref_In as a reference for computing the phase of the electrical signals received at the terminals Prob_In 1 and Prob_In 2 (S 28 ). And the phases measured are recorded at the characteristic computing section 28 .
When the light source system 10 stops operating, the characteristic computing section 28 computes the group delay characteristic and the wavelength dispersion characteristic of the first optical fiber transmission line 32 (S 29 ). The group delay characteristic can be computed from the relationship between the phases measured by the phase comparator 26 and the modulation frequency fm. The wavelength dispersion characteristic can be computed by differentiating the group delay characteristic by the wavelength.
According to the third preferred embodiment, it is possible to measure the wavelength dispersion of the first optical fiber transmission line 32 and the second optical fiber transmission line 34 even if only one fiber pair can be secured.
In the meanwhile, the embodiment described above can be realized by having a media reading apparatus of a computer provided with a CPU, a hard disk, memory media (a floppy disk, a CD-ROM, etc.) read a program executing various functions described above and installing the program on a hard disk. In this way, the functions described above can be performed.
According to the present invention, it is possible to measure group delay characteristic and other characteristics even if the device under test is a single fiber pair. | An apparatus including a variable wavelength light source for generating a variable wavelength light, a first light modulator for inputting into a first optical fiber transmission line a first incident light obtained by modulating the variable wavelength light by a frequency of an electrical signal inputted, a first converter for converting the first incident light, a fixed wavelength light source for generating a fixed wavelength light, a signal source for generating a reference electrical signal, a second light modulator for inputting in a second optical fiber transmission line a second incident light obtained by modulating the fixed wavelength light by a frequency of the reference electrical signal and a second converter for converting the second incident light and for outputting the electrical signal into the first light modulator. | 6 |
The Government has rights to this invention pursuant to Contract No. DASG60-87-C-0014, awarded by the Department of the Army.
BACKGROUND OF THE INVENTION
This invention relates to an electronically scanned phased array radar and more particularly to an apparatus and method for improving angular measurement of an antenna beam by decorrelating peak phase quantization errors of digital phase shifters in the antenna using digital randomization.
A phased array antenna comprises a plurality of radiating elements typically arranged in planar and doubly periodic grid. Such an antenna in a radar system is well adapted to electronic scanning techniques which permit a pencil beam of electromagnetic energy to be moved rapidly from one direction to another by means of a plurality of phase shifter elements.
The phased array antenna can be corporate-fed or optically-fed from one or more radio-frequency (RF) sources. Uncollimated and unsteered power from such one or more RF sources equally distributed to individual elements passes through the phase shifter device and is radiated therefrom with a phase relationship determined by the setting of the individual phase shifter so as to provide the desired collimated and steered radiated wavefront. By the reciprocity theorem the device is reciprocal, i.e., energy reflected from distant objects and impinging on the array in the form of plane wavefront will be focused by the array in a direction corresponding to the setting of the individual phase shifter.
In U.S. Pat. No. 4,445,119, entitled "Distributed Beam Steering Computers," issued Apr. 24, 1984, to George A. Works, and assigned to the present assignee, a microcomputer is co-located with each phase shifter of a phased array antenna for calculating a phase shift steering command for each element of the phased array antenna. Such a distributed microcomputer or controller approach significantly reduces wiring, cables and differential drive cards and improves reliability.
Furthermore, in the prior art, it is well known that a digital phase shifter produces a phase quantization error which increases the pointing error of the antenna beam and antenna pattern sidelobe levels. For example, in an article entitled "Minimizing the Effects of Phase Quantization Error in an Electronically Scanned Array", by C. J. Miller, Proc. of Symposium on Electronically Scanned Array Techniques and Applications, RADC-TDR-64-225, Vol. 1, Jul. 1964, pp. 17-38, Miller suggests introducing variable lengths in the lines of a corporate-fed phased array antenna in order to minimize the peak phase quantization errors. To accomplish this phase error reduction, a piece of cable or waveguide segment has been inserted in series with each phase shifter in order to decorrelate this phase quantization error. Such an approach is referred to as "cable randomization" and it has been used in phased array radar systems such as the Cobra Dane (AN/FPS-108) Radar System used by the U.S. Air Force. (See "Cobra Dane Wideband Pulse Compression System," by E. Filer and J. Hartt, Paper No. 61, 1976 IEEE EASCON, Washington, D.C., Sept. 1976, pages 26-29). In this phased array radar system, 6-bit cable randomization was implemented with a 4-bit phase shifter for peak pointing error reduction of the antenna beam at reasonable cost.
However, more recent applications of phased array radars require higher angular measurement for antenna beam steering accuracies, which require phase quantization errors of digital phase shifters to be reduced significantly. For an angle accuracy specification of 50 microradians, an 8-bit cable randomization would be required in certain applications, but 6-bit cable randomization is a practical limit.
SUMMARY OF THE INVENTION
Accordingly, it is therefore an object of this invention to provide a distributed controller at each element of a phased array antenna to reduce phase shift error by performing digital randomization.
It is a further object of this invention to decorrelate peak phase quantization errors of digital phase shifters using digital randomization in order to improve angular measurement of the antenna beam and to reduce sidelobe levels of the antenna.
The objects are further accomplished by providing a phased array radar system comprising a source of electromagnetic energy, a plurality of antenna array elements for providing a directed beam of the electromagnetic energy, each of the array elements comprises a distributed controller, a phase shifter coupled to the distributed controller and an antenna element coupled to the phase shifter, means for feeding the electromagnetic energy to the plurality of antenna array elements through the plurality of phase shifters, means for coupling phase shift data to each distributed controller in the array elements, such data being used to compute a phase shift command word for each of the antenna elements in accordance with the position of each antenna element in the array, and the distributed controller comprises means for decorrelating the peak phase quantization error. The decorrelating means comprises means for computing the phase shift command word using digital randomization data. The distributed controller comprises means for storing constant data, variable data and random phase adjust data for each of the array elements, arithmetic means for multiplying the variable data by the constant data to obtain product terms of the phase shift command word for each of the array elements, and means for adding the product terms to the random phase adjust data in accordance with a predetermined beam steering angle equation for each of the array elements to accomplish digital randomization of the peak phase quantization error. The distributed controller further comprises an output controller for generating transmit and receive signals, providing external control data, storing a phase shift command word output and providing built-in test (BITE) operations.
The objects are further accomplished by a phased array antenna comprising a plurality of array elements, each of the array elements comprising a distributed controller, a phase shifter coupled to the distributed controller, and an antenna element coupled to the phase shifter, input means coupled to the distributed controller for providing control data, variable data, random phase adjust data and modes of operation data, the distributed controller comprises means for decorrelating peak phase quantization error in accordance with a predetermined phase shift command word equation calculation using the random phase adjust data, the distributed controller means further comprises arithmetic means for computing the phase shift command word, means coupled to the input means for controlling the arithmetic means and the transfer of the input data into the distributed controller, and means coupled to the controlling means and the arithmetic means for storing the input data provided by the input means. The arithmetic means comprises means for multiplying the variable data by the constant data to obtain product terms of the phase shift command word for each of the array elements, and means for adding the product terms to the random phase adjust data in accordance with the phase shift command word equation for each of said array elements to accomplish digital randomization of the peak phase quantization error. The distributed controller comprises an output controller for generating transmit and receive command signals, providing external control data, storing a phase shift command word output and providing BITE operations.
The objects are further accomplished by providing a method of reducing peak phase quantization errors in a phased array radar system comprising the steps of providing a source for electromagnetic energy, directing a beam of the electromagnetic energy with a plurality of antenna array elements in the antenna system, each of the array elements comprising a distributed controller, a phase shifter coupled to the distributed controller and an antenna element coupled to the phase shifter, feeding the electromagnetic energy to the plurality of antenna array elements through the plurality of phase shifters, and coupling phase shift data to each distributed controller in the array elements for computing a phase shift command word for each of the antenna elements in accordance with the position of each antenna element in the array, and decorrelating peak phase quantization error by means in the distributed controller. The step of providing means for decorrelating peak phase quantization error comprises using digital randomization data. The step of computing a phase shift command word comprises the steps of storing constant data, variable data and random phase adjust data for each of the array elements, multiplying the variable data by the constant data to obtain product terms of the phase shift command word for each of the array elements, and adding the product terms to the random phase adjust data in accordance with a predetermined beam steering angle equation for each of the array elements to accomplish digital randomization of the peak phase quantization error.
BRIEF DESCRIPTION OF THE DRAWINGS
Other and further features and advantages of the invention will become apparent in connection with the accompanying drawings wherein:
FIG. 1 is a simplified block diagram of a phased array radar system embodying the invention of digital decorrelator in a beam steering distributed controller which provides digital randomization at each phase shifter element of a phased array antenna;
FIG. 2 is a flow chart of the present invention of digital randomization for reducing peak phase quantization error;
FIG. 3 is a block diagram of the distributed controller embodying a digital decorrelator for reducing peak phase quantization error;
FIGS. 4(a)-4(d) show the effect of randomization techniques on decorrelating peak phase errors due to quantization of the phase shifter in a corporate-fed phased array antenna;
FIG. 5 is a graph showing a correlated peak pointing error of the steered beam and reduced pointing error of the steered beam decorrelated by using digital randomization;
DESCRIPTION OF THE PREFERRED EMBODIMENT
Referring to FIG. 1, there is shown a phased array radar system 10 having a phased array antenna 25 comprising a plurality of antenna elements 26 l-n , each element having a radiating aperture 27 l-n fed by a phase shifter 24 l-n and a beam steering distributed controller 20 l-n coupled to said phase shifter 24 l-n comprising a digital decorrelator invention employing digital randomization for reducing peak phase quantization error. The distributed controller 20 l-n comprises a very large scale integrated (VLSI) circuit chip employing CMOS technology for calculating the phase shift for each particular element of the phase array antenna 25 based primarily on the phased array antenna 25 geometry and the element 26 l-n location. Electromagnetic energy is distributed by a feed system 14 through the phase shifters 24 l-n for determining the direction of the energy beam 28 emitted from the phased array antenna 25. The beam steering command is accomplished by calculating the amount of phase shift to be applied to the radiant energy of the phase shifter from the feed system 14 and such phase shift calculation, depending on application requirements, may include a temperature correction (TC) factor for temperature effects at each antenna element location as described in U.S. patent application Ser. No. 608,047, filed Oct. 31, 1990 by John C. Murray et al., and assigned to the present assignee.
A source of electromagnetic energy is provided by a transmitter 11, and a duplexer 12 controls the energy being transmitted and received by the array antenna 25. A radar return signal is sent to a receiver 16 and an electronic unit 18 provides timing and control signals for the complete phased array radar system 10. A control computer 19 performs the data processing of the radar data and performs built-in test (BITE) or self-test capability for aiding in diagnostics and fault isolation of the distributed controllers 20 l-n . The control computer 19 provides initialization data comprising algorithm constants to each of the distributed controllers 20 l-n . Three serial control lines, clock 32, mode 34 and data 36 are coupled from the control computer 19 to the distributed controllers 20 l-n and one serial BITE line is coupled from the distributed controllers 20 l-n to the control computer 19. The three serial control lines enable the distributed controllers 20 l-n to be communicated with individually or all controllers 20 l-n simultaneously.
Each distributed controller 20 l-n in the present
embodiment performs a phase shifter command (Φ MN ) calculation using the following phase shift algorithm in order to determine a global beam steering angle command:
Φ.sub.MN =MDCX.sub.MN *S+MDCY.sub.MN *T +DP.sub.MN *TR+MΔΦ.sub.COL +NΔΦ.sub.ROW +γ
where:
(a) M,N are the array column and row geometry indices (16 bits each).
(b) ΔΦ COL and ΔΦ ROW are the incremental column and row phase shift commands (16 bits each).
(c) CP MN *TR is the addition of 0 degrees (TRA) or 180° (REC) for half of the elements, where DP is 180° and TR is zero or one for transmit and receive duplexing.
(d) γ is a random phase adjustment term generated using digital randomization.
(e) MDCX MN and MDCY MN are the array deflection compensation terms, as a function of M and N.
(f) S and T are two array deflection variables that are extracted from a look-up table when the array is tilted at a specific angle in the elevation plane.
In the above equation, Φ MN is the amount of phase shift per array element required to achieve a certain overall beam direction 28 as illustrated in FIG. 1. However, one skilled in the art readily knows that certain terms of such equation other than the column and row phase shift terms and the random phase adjustment term may vary depending on the architecture of the specific phased array antenna design. The computed result of the phase shift command word comprises an integer part plus a fractional part. Only the fractional part, or least significant bits, are needed to control the phase shifter in a phase steered antenna. In a time-delay steered antenna, the complete phase shift command word would be used.
The M and N index constants provide coordinate information for each element in an array antenna in order to form the beam 28 coherently in a specific direction. Typically, the ΔΦ COL variable equals (sin α)/λ and ΔΦ RPW equals (sin β)/λ where alpha (α) represents the elevation steering angle and beta (β) represents the azimuth steering angle; lambda (λ) represents the wavelength of the radial frequency emitted on antenna beam. Other variables may be defined depending on the type of phased array antenna and application requirements known to one skilled in the art. Sin α, sin β, etc. and 1/λ phase shift parameters are simultaneously sent to all array elements for determining a specific amount of phase shift to form the antenna beam 28 in a desired direction. Therefore, the constants are stored in each distributed controller and the phase shift parameters are received via serial data 36 lines as shown in FIG. 2. When the reciprocal of λ is sent to the distributed controller, a multiplication is performed instead of a division when calculating the phase shift command, Φ MN . Any number and combination of constants may be used in this phase shift algorithm depending on system requirements. After the calculations have been completed, the distributed controller 20 l-n can format the phase shift value into various types of outputs, including digital outputs of up to 8 bits for diode phase shifter applications and pulsed outputs for systems using ferrite phase shifters.
Referring now to FIG. 2 and FIG. 3, FIG. 2 is a flow chart of the present invention of a digital decorrelator routine 40 employing digital randomization. FIG. 3 is a block diagram of the distributed controller 20 l-n embodying the digital correlator routine 40. The digital decorrelator routine 40 operates on data received from the control computer 19 which is stored in a RAM 72 of the distributed controller 20 l-n . The decorrelator routine 40 is also located in RAM 72, and the purpose of this routine is to reduce peak phase quantization error, which if not reduced results in large pointing error of the antenna beam direction 28 (α). When power-up 42 occurs, a clear signal is generated which clears all the registers and RAM 72 in the distributed controller 20 l-n . Next a load program control word 44 (as defined in Table 4) operation is performed wherein the program control word is loaded into the distributed controller 20 l-n and stored in the RAM 72. Then initialize constant data 46 operation occurs which loads constant data of the array geometry and element location from the control computer 19 into the RAM 72. Next, a load random phase adjust term 48 occurs which provides a unique random number having an upper bound of a least significant bit of the phase shifter for each phase shift element location of the array; such phase adjust terms are stored in RAM 72. As a result of this random number being added into the phase command, a stochastic resonance is produced in the phased array, that is, a cooperative effect of the stochastic perturbation (random phase adjust data) and periodic forcing, which is the product term of the phase command, leads to an amplification of the peak of the power spectrum requiring only small amounts of phase command, due to a mechanism such as a phased array antenna. With stochastic resonance any small amount of force (phase command) can steer the beam away from its "old" position. A compute phase shift command word 50 operation is then performed which performs the operation of load variable word of beam steering command 52, multiply variable word with constant data of element location 54 and add random phase adjust term 56. The computed phase shift command word (Φ MN ) is then forwarded to the phase shifter 24 l-n , and next phase shift command word is computed for another element location.
To understand the operation of the present invention, the pointing error of a 10-foot X-band phased array is evaluated. Such an array contains 21,504 elements each containing a 6-bit digital ferrite phase shifter 24 l-n with a 16-bit distributed controller 20 l-n . The formats of constants (C2-C7) and variables (φ1-φ6) for the phase shift algorithm is shown in Table 1 and their value ranges are shown in Tables 2 and 3. Note that for M and N, the LSB is 2°. The random phase adjust term (γ) is generated by a random number generator and its value is ranged from 2 -6 to 2 -16 for maximizing decorrelation capability and minimizing artificially injected error. The first column in Table 1 further shows the sequence of the calculations performed to solve the equation for Φ MN as defined above. The 16-bit distributed controller 20 l-n operates such that the result of multiplying the LSB's of the constants and variables equals the LSB of the result. Thus, for the six bits of the phase shifter to be at the correct outputs, the LSB of the result must be 2 -16 as shown in Table 1.
TABLE 1______________________________________Φ.sub.MN FORMATTERMS BITS +/MSB LSB C/V______________________________________MDCX.sub.MN 10 S 2.sup.-1 2.sup.-2 2.sup.-3 2.sup.-9 C7S 16 2.sup.8 2.sup.7 2.sup.6 2.sup.5 2.sup.-7 Φ1+MSCY.sub.MN 10 S 2.sup.-1 2.sup.-2 2.sup.-3 2.sup.-9 C6*T 16 2.sup.8 2.sup.7 2.sup.6 2.sup.5 2.sup.-7 Φ2+DP.sub.MN 10 S 2.sup.7 2.sup.6 2.sup.5 2.sup.-1 C5*TR 16 2.sup.0 2.sup.-1 2.sup.-2 2.sup.-3 2.sup.-15 Φ3+M 16 S 2.sup.14 2.sup.13 2.sup.12 2.sup.0 C4*ΔΦ.sub.COL 16 2.sup.-1 2.sup.-2 2.sup.-3 2.sup.-4 2.sup.-16 Φ4+N 16 S 2.sup.14 2.sup.13 2.sup.12 2.sup.0 C3*ΔΦ.sub.ROW 16 2.sup.-1 2.sup. -2 2.sup.-3 2.sup.-4 2.sup.-16 Φ5+γ 16 S 2.sup.-2 2.sup.-3 2.sup.-4 2.sup.-16 C2*1 16 2.sup.15 2.sup.14 2.sup.13 2.sup.12 2.sup.0 Φ6= MSB LSBΦ.sub.MN 16 2.sup.-1 2.sup.-2 2.sup.-3 2.sup.-4 2.sup.-16 (BITS 2.sup.-1 to 2.sup.-6 used for Φ.sub.MN______________________________________ Command)
TABLE 2______________________________________CONSTANT MAX VALUE LSB NOTES______________________________________MDCX.sub.MN ±2.sup.-2 ±2.sup.-9 0.3 Inch Maximum DeflectionMDCY.sub.MN ±2.sup.-2 ±2.sup.-9 0.3 Inch Maximum DeflectionDP.sub.MN 2.sup.-1 2.sup.-1 DUPLEXING (Transmit or Receive)M ±2.sup.6.46 ±2.sup.0 +88 to -87 dx = .69992" Element Spacing in ColumnN ±2.sup.7.29 ±2.sup.0 +157 to -156 dy = .4041" Element Spacing in Rowγ 2.sup.-6 -2.sup.-16 -2.sup.-16 ROUNDING (2.sup.-7) & RANDOM PHASE ADJUST______________________________________
TABLE 3______________________________________VARIABLE MAX VALUE LSB NOTES______________________________________S,T 2.sup.0 2.sup.-7 Deflection Look-Up (Elevation Angle)TR 2.sup.0 2.sup.-15 DuplexingΔΦ.sub.COL 2.sup.0 -2.sup.-16 2.sup.-16ΔΦ.sub.ROW 2.sup.0 -2.sup.-16 2.sup.-161 2.sup.0 2.sup.-1 To Align γ______________________________________
Referring now to FIG. 4, the improvement in angular measurement resulting from decorrelation of the peak quantization error using either cable or digital randomization is illustrated schematically for a worst-case situation. This illustration using cable randomization was provided in an article by Rainer H. Sahmel and Roger Manasse, "Spatial Statistics of Instrument--Limited Angular Measurement Errors in Phased Array Radars," IEEE Transactions on Antennas and Propagation, Vol. AP-21, No. 4, Jul. 1973, pp. 524-532. A one dimensional case has been considered where the desired phase is a linear function of the aperture coordinate X. As illustrated in FIG. 4(a), the beam steering of the array normal is small, and the commanded phase causes only the phase shifters at the very edge of the aperture to switch out of the zero state. In FIG. 4(b), the difference between the commanded and actual phase function is a linear phase error term which will cause an angular error approximately equal to the commanded steering angle. FIG. 4(c) illustrates the effect of randomized quantization levels. The horizontal dashes indicate the location of the nearest quantization levels for each phase shifter. In all cases, the commanded phase is quantized to the nearest available quantization level. The resulting phase errors at each phase shifter shown in FIG. 4(d) are seen to have a random character which will not give rise to a large angular error.
Referring now to FIG. 5, a graph of pointing error (μR) of the antenna vs. array scan (μR) shows the correlated (peak) error in the phased array antenna without randomization and the resulting significantly reduced decorrelated error when the digital randomization of the present invention is employed.
Referring again to FIG. 3, the beam steering distributed controller 20 l-n shown is implemented with VLSI CMOS gate-array technology on a 0.300"×0.300" die. Differential receivers 62 receive the differential forms of the three serial control signals clock 32, mode 34 and data 36 and provide these signals to a chip controller 64. The chip controller 64 converts the serial mode 34 and data 36 signals into parallel control words for use by other portions of the distributed controller 20 l-n . A program control register 68 within the chip controller 64 stores a 20-bit program control word which determines the terms and variable word length used for a phase shift algorithm and defines the current BITE mode. Table 4 lists the individual bit functions of the program control word. A mode control register 66 stores the mode word received from the control computer 19 and the mode word is decoded and used both in a direct form and in a pulsed form to provide required mode control. The functions of the decoded mode word are listed in Table 5. The functions of the BITE mode bits of the program control word are listed in Table 6.
The random access memory (RAM) 72 receives data from the serial data 36 input under the control of the chip controller 64. The RAM 72 stores the constants for each element location, beam steering command data and a random phase-adjust term of the phase-shift algorithm until needed by an arithmetic unit 74.
The arithmetic unit 74 comprises a 17-bit serial multiplier and serial adder (not shown but known to one skilled in the art) which forms partial product terms and subsequently a full product term. The product term size is that of a BAMS (Binary Angular Measurement System) variable. The full product term is added to any other accumulated terms such as γ of the phase-shift algorithm using the 17-bit serial adder within the arithmetic unit 74. Any negative constant term is taken care of by including a 2's compliment adjustment at the input to the serial adder. The final accumulated result is truncated to eight most significant fractional bits (MSBs) for parallel output to an output controller 76.
TABLE 4______________________________________ProgramControlWord Bit Function Description______________________________________ 1 Start Bit 2 B0 3 B1 Built-In Test Mode 4 B2 5 Spare 6 Phase Adj. Selects Phase ADJ Term 7 Spare 8 T/R Transmit/Receive 9 Out Mode Activates Pulse Mode for Ferrite Shifters10 Spare11 VLO12 VLI Selects Variable Word Length13 VL214 C7 MDCX.sub.MN15 C6 MDCY.sub.MN Phase Shift16 C5 TR.sub.MN Algorithm17 C4 M Constant18 C3 N Enables19 C2 γ20 C1 Not Used______________________________________
TABLE 5______________________________________Mode WordM3 M2 M1 M0 Mode Function______________________________________0 0 0 1 Initialization0 0 1 0 Compute0 0 1 1 Output Trigger0 1 0 0 Master Clear0 1 0 1 Data Clear0 1 1 0 BITE Trigger1 0 0 0 Receive Trigger1 0 0 1 Reset Trigger1 0 1 1 Load External Control Register1 1 0 1 Load Program Control Word1 1 0 1 Load BITE1 1 1 0 BITE Enable1 1 1 1 BITE Reset______________________________________
TABLE 6______________________________________BITE Mode Code (B2 to B0) BITE MODE FUNCTION______________________________________000 Data Rebound001 External Control010 Parallel Output100 Pulse Output101 T/R Control111 Bit Wiggle______________________________________
If it is desired in a specific application to compensate for temperature variations at each element of the array antenna 27 l-n , a temperature correction (TC) factor for the phase shift algorithm may be generated from an ambient temperature measurement made by a thermal sensor and fed into the distributed controller 20 l-n as described in U.S. patent application Ser. No. 608,047 referenced hereinbefore. The temperature correction (TC) factor would be fed to the serial adder input of the arithmetic unit 54 which may be added into the sum of products in the beam steering calculation producing a phase output which has been corrected for temperature at the antenna element location.
Still referring to FIG. 3, the eight MSBs of the phase-shift calculated in the arithmetic unit 74 are transferred to an output controller 76 where they are loaded into an 8-bit phase output register 82. In a bit wiggle mode of operation a phase value can be loaded directly from the input data 36 line and then transferred to the phase output register 82. The output controller 76 comprises a 16-bit external control register which is loaded directly from the data 36 input and it is used to store external control words to control, for example, attenuators. Transmit (TRA) and receive (REC) control signals are derived from a decoded T/R mode signal fed to a T/R control 78 in the output controller 76. The TRA and REC control signals are used to switch monolithic microwave integrated circuit (MMIC) devices and subsequently control the transmit/receive duty cycles.
The output controller 76 also comprises a built-in test (BITE) decoder 84. A BITE code (B 2 B 1 B 0 ) of the program control word (Table 4) is decoded and used to select one of four BITE return modes listed in Table 6 comprising data rebound BITE, external control BITE, parallel output BITE (PARBITE) and T/R control BITE. In a data rebound mode, data sent by the chip controller 64 is automatically returned on the BITE 38 line to confirm correct reception by the distributed controller 20 l-n . The external control BITE mode allows any data stored in the 16-bit external control register (ECR) 80 to be transferred serially to the BITE 38 line. In the parallel output BITE (PARBITE) mode any phase value stored in the phase output register 82 can be clocked-out serially onto the BITE 38 line by first transferring the 8-bit value to the eight least significant bit (LSB) positions of the external control register 80. The T/R control BITE mode verifies that the distributed controller 20 l-n has been placed in the transmit mode or receive mode. The logic-OR of the transmit (TRA) or receive (REC) control signals is placed on the BITE 38 line for verification. The BITE 38 line is connected to a differential driver 86 for transferring BITE data to the control computer 19. The control computer 19 sets up each distributed controller 20 l-n into the BITE mode and tests the data sent back over the BITE 38 line. The distributed controller 22 l-n may be embodied by a CMOS VLSI chip, Part No. 295A089, manufactured by Raytheon Company of Lexington, Mass., the present assignee.
This concludes the description of the preferred embodiment. However, many modifications and alterations will be obvious to one of ordinary skill in the art without departing from the spirit and scope of the inventive concept. Therefore, it is intended that the scope of this invention be limited only by the appended claims. | An improved means of decorrelating phase quantization errors in a phased array radar antenna using digital randomization at each of the array elements to reduce peak steering erorrs and to reduce peak sidelobe levels of the antenna. A random phase adjust term is provided to each of the array's antenna elements which comprises a distributed controller (DC) co-located with a digital phase shifter. The distributed controllers are each programmed with a random phase adjust term which represents a phase shift adjustment statistically independent from element to element. The random phase adjust term is stored in a memory located in each disbtributed controller. The distributed controller drives each element's digitally controlled phase shifter in response to a beam steering command received over a serial line. The performance improvement achieved with this decorrelation method is equivalent to that obtained by using more expensive phase shifters and adding costly randomized cables in the path to each element. | 7 |
FIELD OF THE INVENTION
The present invention relates generally to the art of snow plows and more particularly to snow plows of the type which are suitable for use with small vehicles, such as cars.
BACKGROUND OF THE INVENTION
Many different types of snow plows are known to the art. Conventional plows include a blade and a frame for coupling the blade to the front of a vehicle. More sophisticated plows also include means for adjusting the angular orientation of the plow blade relative to the longitudinal axis of the vehicle and for elevating the plow blade relative to the road surface to permit the vehicle to be driven from one location to another.
Prior art snow plows are also known for use with many different sizes of vehicles. For example, plows are known which can be used with very large vehicles. These plows are typically used for large snow removal jobs such as airport runway clearing and the like. Smaller plows are known which can be coupled to dump or garbage trucks for use in road clearing operations, and still smaller snow plows are know which may be coupled to yet smaller trucks for use in driveway or parking lot clearing and the like. A typical example of the latter would be the type of plow frequently employed by the owner of a gasoline station for use with his tow or pick-up truck. Following a snowfall, such a plow would be coupled to the front end of the tow truck for use in clearing the station as well as for other snow clearing jobs in the neighborhood.
The type of plow just referred to is usually quite expensive, requires considerable time to attach to a vehicle, and includes structural features which makes them impractical for use with cars. For example, such plows commonly include a hydraulic pump assembly mounted externally of the vehicle, a feature which increases the exposure of the operating components to adverse weather conditions and increases the likelihood of theft or vandalism of the equipment. Moreover, such plows also include a bulky, view-obstructing plow lifting system mounted immediately adjacent the front end of the vehicle which includes a hydraulic cylinder oriented upwardly to engage a lifting arm which in turn is coupled to the plow by a chain. Extension of the cylinder causes the arm to be elevated which in turn causes the chain to lift the plow blade above the road surface. This type of lift system, both because of its bulk and because of its tendency to shift weight off the back wheels of the vehicle, make this type of plow unsuitable for smaller vehicles such as cars. Typical examples of this type of plow are described in Simi's U.S. Pat. No. 3,037,275, issued Mar. 7, 1967, for "Vehicle Accessory Unit and Power Unit Therefore," and in Micelli's U.S. Pat. No. 3,706,144, issued Dec. 19, 1972, for "Control Means for a Snowplow." Also, the devices described in these patents make no provision for locking the blade in its elevated position. Driving a snow plow at a high rate of speed with an elevated blade is potentially dangerous, because any failure of the hydraulic system could cause the blade to fall to the road surface resulting in damage to the vehicle, or more importantly, injury to the driver. A similar result could occur if the lifting chain breaks or is accidently uncoupled from the plow.
Another related type of snow plow is described in Jackoboice's U.S. Pat. No. 3,524,269, issued Aug. 18, 1970, for "Mounting Means for Vehicular Implements." This device is different from that described above in that instead of using a vertical frame and upwardly directed hydraulic cylinder for raising the plow, it employs a horizontal cylinder which rotates a round member mounted to the plow blade frame to lift the plow. The vehicle's bumper supports one end of a lifting chain. The other end of the chain is attached to the round member and is wound therearound at the discretion of the driver to cause shortening of the chain length and resultant lifting of the blade. While the lifting mechanism is different, this type of plow still suffers from the same disadvantages as those discussed above which significantly impair the adaptability of this type of plow for use with small vehicles, such as cars.
Yet another type of lifting system for plow blades and the like is illustrated in Holopainen's U.S. Pat. No. 3,165,842, issued Jan. 19, 1965, for "Mechanism for Attaching Implements to Vehicles." In the described device a link is located intermediate the subframe assembly and the implement and a cylinder acts on the link to rotate it and push the implement upward.
None of the aforementioned systems are entirely satisfactory for use with small vehicles, such as cars. This special utility requires ease of attachment, a lift system which will not obstruct the driver's view and a blade lift system which does not cause detrimental weight distribution problems or alter the vehicle's normal driving characteristics. The development of a snow plow assembly which would obtain these objects and overcome the difficulties of the prior art would be a significant advance in this technology.
OBJECTS OF THE INVENTION
It is the primary object of the present invention to provide a snow plow assembly which can be used on a variety of sizes of vehicles, including fuel-efficient small cars.
Another object of the present invention is to provide a snow plow attachment means which includes an improved means for raising the plow blade above a surface.
Yet another object of the present invention is to provide a snow plow system in which the hydraulic means for causing movement of the plow blade is mounted within the engine compartment of a vehicle.
Still another object of the present invention is to provide a snow plow assembly which can be quickly coupled to or uncoupled from a vehicle. Another object of the present invention is to provide locking means for a snow plow, said locking means preventing a plow blade which has been elevated from falling to the road surface.
How these and other objects of the invention are accomplished will be described in the following specification, taken together with the FIGURES. Generally, however, they are accomplished by providing a vehicle subframe assembly coupled to the chassis of a vehicle, such as a car. A generally triangular plow support frame assembly is coupled to the subframe assembly by two pins. The plow frame support assembly includes a plow blade at its forward end as well as three hydraulic cylinders, two of which are for horizontally varying the angular orientation of the blade with respect to the longitudinal axis of the vehicle, and the third one of which is provided for lifting the plow blade with respect to the road surface. Each of the cylinders are coupled to a hydraulic system, the major components of which are located within the engine compartment of the vehicle. Quick connections are preferably made near the vehicle's front bumper and the controls for the cylinders are mounted in the vehicle at or near the dash board. The lifting system of the present invention includes a bell crank coupled to the free end of the piston rod of the third cylinder, to the plow frame behind the plow blade and to a support bracket mounted to a lifting bar located behind the front bumper. The bell crank itself includes two links which will be described in detail hereafter. Another feature of the preferred embodiment of the present invention is a lock sleeve which can be secured about the piston rod of the third cylinder to prevent retraction of the cylinder, even if the hydraulic system fails or any of the hydraulic hoses rupture or are punctured. Various component modifications are also described herein which are deemed to fall within the scope of the present invention.
DESCRIPTION OF THE DRAWINGS
FIG. 1 is a perspective view of the snow plow assembly according to one preferred embodiment of the present invention;
FIG. 2 is a detailed side view of the bell crank lifting system of the present invention; and
FIG. 3 is a schematic of the hydraulic system of the present invention.
DESCRIPTION OF THE PREFERRED EMBODIMENT
FIG. 1 is a perspective view of a snow plow assembly 10 according to the preferred embodiment of the present invention. Assembly 10, as illustrated, is coupled to the front end of a car 12, but the invention is not limited for use with cars. While it is true that the snow plow of the present invention is especially useful for smaller, fuel-efficient vehicles with which other commercially available plows are not suitable, assembly 10 could be readily adapted for use with jeeps, recreational vehicles, pick-up trucks, tow trucks and other types of trucks. Moreover, the system could be used with other vehicles such as tractors, bulldozers and the like.
A coupling frame 14 is also shown in FIG. 1, frame 14 includes two side bars 15, and a front connecting member 16. Side bars 15 are parallel to one another and are preferably made of angle steel and extend from an area generally below the front bumper 20 of vehicle 12, along the bottom of the vehicle chassis just inside the wheel to an area typically near the vehicle's transmission mount (not shown). The side members 15 are bolted or otherwise securely fastened to the chassis and preferably to the front hold-down brackets, but the details thereof are not provided because the particular configuration of side bars 15 will depend on the type of car 12 with which they are to be used. It should be mentioned, however, that the system employed for mounting side bars 15 should facilitate the easy coupling and uncoupling of frame 14 to the car, since frame 14 would not normally be employed during warm weather.
The front connecting member 16 is welded between the forward ends of side bars 15 generally below the car's front bumper 20. Again, this member is preferably constructed of steel. A pair of brackets 24, which in the illustrated embodiment comprise a pair of forwardly extending short plates 26, having axially aligned holes, are provided on front member 16 just inwardly of the corners of the car 12.
The second major component of the present invention is a plow blade support frame 30 which comprises a generally triangular frame consisting of a rear side member 31 and forwardly extending side members 32. Each component is preferably constructed of angle steel. Frame 30 also includes a pair of coupling plates 35 which are welded to frame 30 adjacent the rear corners thereof, plates 35 being arranged and adapted for being inserted between the brackets 24 of frame 14. The coupling plates 35 also include a hole therethrough so that quick disconnect pins 37 may be inserted through the three aligned holes to pivotally couple blade support frame 30 to frame 14. It will be appreciated then that the forward end of frame 30 is movable about a circular arc having an axis defined by pins 37.
A conventional plow blade 40 is pivotally connected to the forward end of support frame 30 so that the horizontal orientation of the blade may be adjusted relative to the axis of the vehicle and the present invention includes means for controlling such horizontal orientation and will be discussed in a later section of this specification. Blade 40 also includes a semi-circular segment 42 welded to the back of the blade. The segment includes a flate horizontal surface 43 and a vertical ridge 44 on the inner surface of the arc forming a track-like segment. A small triangular plate 45, is welded to the front of the support 30, the bottom of segment 42 being slidably received thereon. A restraining bracket 46 is bolted to triangular plate 45 to prohibit vertical movement of segment 42 with respect to plate 45, while permitting sliding movement of horizontal surface thereunder.
FIG. 1 also shows the snow plow assembly 10 to include a pair of springs 48 which permit the blade 40 to tip relative to the road surface if an obstruction is encountered. Springs 48 are connected between a pair of vertical supports 50 welded onto either side of segment 42 and a pair of adjustable eyelets 51 secured generally near the top of blade 40 on the back side thereof. Eyelets 51 include threaded stems 52 and lock nuts to vary the length of springs 48 and in turn control the tension applied thereby. Eyelets 51 are secured to the upper portion of the blade 40 through a pair of brackets 54. From this description it should be understood that, if the bottom of plow blade 40 is obstructed during forward movement of the vehicle, the top of blade 40 will tip forwardly to allow the lower edge of the blade to pass over the obstruction.
Before proceeding with the description of the blade maneuvering system of the invention, it should be pointed out that other conventional equipment may be employed with the snow plow assembly 10. For example, adjustable skids (not shown) can be mounted to the blade support or the blade itself for displacing the blade by a preselected distance from the road surface. Likewise, any shape of plow blade may be employed, whether it be of the concave variety shown in the FIGURES or of the V-shaped design known to the art.
Referring again to FIG. 1, snow plow assembly 10 also includes a pair of hydraulic cylinders 60 and 61, for controlling the horizontal orientation of blade 40. Cyclinder 60 and 61 each include an extensible piston rod 62 and 63 and hydraulic fluid hoses 64 and 65 respectively. The cylinders themselves are pivotally mounted to brackets 66 on the rear side 31 of blade support 30 and are spaced apart from one another but are relatively nearer the axis of the vehicle 12. The piston rods 62 and 63 are pivotally mounted to brackets 67 on the arcuate segment 42 intermediate the vertical supports 50 and the connections of segment 42 to the blade 40. In this manner, it can be seen that the extension of piston rod 61 and corresponding retraction of the other piston rod 62 will result in movement of the blade toward the right, and vice versa.
By further reference to FIG. 1 and now by reference also to FIG. 2, the blade lifting mechanism of the present invention can be understood. A third hydraulic cylinder 72, having a piston rod 73, and fluid hose 74, is pivotally coupled to bracket 75 located at the middle of rear side 31 of blade support 30. In this position, piston rod 73 is oriented generally toward triangular plate 45. Another bracket 76 is mounted horizontally to the rear surface of plate 45, bracket 76 including a pair of parallel plates 77 having aligned holes (not shown). Yet another bracket 79 is provided behind the car's bumper (see the cut-away portion of FIG. 1), bracket 79 in turn being welded to an elongated steel lift bar member 81 which is rigidly secured to the front of car 12 on the vehicle's bumper bracket (not shown) or to the car's frame. Bracket 79 also includes a pair of parallel short plates 80 having aligned holes therein, but this bracket is directed generally downwardly and slightly forwardly.
A bell crank assembly 85 is mounted between brackets 76 and 79 and the end of piston rod 73 as will now be described. Assembly 85 includes a first generally Y-shaped link member 86 which includes symmetrical side plates 87 and 88. Plates 87 and 88 are welded to one another at the top of link 86 and fit between the plates 80 of bracket 79 and are pivotally secured thereto by pin 90. Side plates 87 and 88 diverge from one another below bumper 20 and then are bent so as to be parallel to one another. A hole (not shown) is provided at the lower end of each of plates 87 and 88.
A second link member 92 is also included in crank assembly 85. Link 92 also includes a pair of side members 94 and 95 each of which is generally L-shaped, the angle between the long and short portions of sides 94 and 95 actually being acute in the preferred embodiment. The long portions of sides 94 and 95 are pivotally mounted to bracket 76 (by pin 97) and to link 86 by a pin 98 passing through sides 87, 88, 94 and 95. The shorter portion of sides 94 and 95 are pivotally coupled between bracket 76 and the end of piston rod 73. It will then be apparent that extension of pistion rod 73 will result in the lower end of link 92 being pushed forwardly under pin 97 causing the entire blade 40 and support 30 to be tilted upwardly. In FIG. 2, the cylinder 72, its piston rod 73, and the link members 86 and 92 are shown in the position they occuply when the blade is elevated.
The piston rod locking means of the present invention is also shown in FIG. 2 to include a cylindrical sleeve 100 adapted to surround the extended piston rod 73. The sleeve 100 is split along its length and is hinged on one side by a hinge 101 while a latch 102 is provided on the other side. Locking sleeve 100 is used as follows: When the blade is elevated (FIG. 2) the locking sleeve is opened and folded back about hinge 101. The sleeve is then placed around the piston rod 73 and locked into place by latch 102. When the sleeve is secured in place, the piston rod cannot be retracted, even if a failure occurs in the hydraulic fluid system.
FIG. 3 shows in schematic form the hydraulic and cylinder control system of the present invention. The placement of the operating components in the vehicle is not critical to the present invention, but it is preferred that the reservoir pump and valve components now to be described be mounted under the hood of the car 12 in its engine compartment.
The hydraulic system includes a tank 105 of hydraulic fluid 106 having inlet and outlet hoses 107 and 108 respectively. A pump P driven by an electric motor M powered by the car's electrical system is coupled to hoses 107 and 108 for supplying and receiving hydraulic fluid from a manifold valve assembly 115.
Valve assembly 115 in turn includes a directional control valve 116 and cross-over relief valve 117 for regulating the horizontal swing of blade 40 and a directional control valve 119 and lock valve 120 for control of the lift system. Hoses 121 and 122 leave the valve assembly swing components and are coupled respectively to hoses 64 and 65 while another fluid hose 123 from the valve lift components is coupled to hose 74. Quick disconnect couplings 128-130 are provided for allowing rapid coupling and uncoupling of the respective hoses between those mounted to the car and those mounted to plow assembly 10.
Toggle switches 136 and 137 are also included in the system, the toggle switches preferably being mounted on the dash board of the car or at some other interior location where they are readily accessible to the driver. Switch 136 is coupled to the valve swing components by wires 140 and controls the flow of fluid to and from cylinders 60 and 61, while switch 137 is connected to the valve lift components by wires 141 and controls the flow of fluid to cylinder 72.
Now that the major components of the present invention have been described, its operation will be explained. When cold weather approaches, frame 14 is bolted to the chassis of car 12. It is assumed that the hydraulic components have been mounted to the car and that switches 136 and 137 have been installed on the car's dash board. Hoses 121, 122 and 123 have their free ends located for ready access from outside the car 12.
When it is desired to use the plow assembly 10 it is connected to the car by merely inserting pins 37 in the two brackets coupling frame 14 to blade support frame 30 and by inserting an additional pin 80 in bracket 79 so that the link member 86 is secured behind bumper 20. The hydraulic hoses 64, 65 and 74 are then coupled hoses 121, 122 and 123 respectively to complete the mounting of assembly 10.
It will be apparent from the foregoing description that toggle switch 137 can be moved by the driver to control the elevation of blade 40 and that toggle switch 136 can be selectively moved to change the horizontal orientation or swing of blade 40.
While the present invention has been described in connection with a single preferred embodiment, it is not to be limited by such description but is to be limited solely by the claims which follow. For example, while the invention has been described in connection with a snow plow, the lift system of the present invention is adaptable for use with bulldozer blades, or other similar types of implements. | A snow plow especially suitable for use with small vehicles, such as cars, is disclosed. The snow plow features a hydraulic system for controlling movement of the plow from side to side as well as for elevating the plow. The blade elevating system of the present invention utilizes a bell crank means coupled intermediate the plow frame and a lifting bar located behind the vehicle's front bumper and provides important advantages over conventional lift systems. The snow plow of the present invention also includes a coupling system which permits the plow to be quickly coupled to the vehicle for snow plowing and quick removal of the plow when the vehicle is to be used for its conventional purposes. A system is also provided for locking the plow blade in its elevated position to keep it from falling while the vehicle is being driven from one snow removal location to another. Finally, the invention's hydraulic system is mounted in the vehicle's engine compartment where it can be locked to prevent theft. | 4 |
FIELD OF THE INVENTION
The present invention relates to a device for tool storage organizer and more particularly, a tool storage organizer that is designed for usage inside a truck.
BACKGROUND OF THE INVENTION
Tool box and tool chest are well known for most truck drivers or handyman. Tool boxes are typically piled with hardware inside and thus do not have the best visual display to quickly locate a tool. There is a need for a tool storage organizer with large display capacity for quick locating a tool needed so that the user can improve his/her work efficiency.
Any feature or combination of features described herein are included within the scope of the present invention provided that the features included in any such combination are not mutually inconsistent as will be apparent from the context, this specification, and the knowledge of one of ordinary skill in the art. Additional advantages and aspects of the present invention are apparent in the following detailed description and claims
SUMMARY OF THE INVENTION
The present invention features a tool storage organizer system. The system comprises a storage organizer installed on the back wall of the truck cabin. The organizer has a back support panel with multiple layers of pocket disposed in the front and multiple horizontal pockets disposed in the back. The multiple layer pockets in the front have various heights but the same bottom endng levels. A plurality of bits slots are attached to pockets of the out layer pockets. The back support panel has multiple grommets near the top edge, which are used to attach to brackets installed on truck wall through a plurality of nooks. A hard rod is attached to the top edge of the back support panel to keep the support in shape when the back support panel is hanged up.
BRIEF DESCRIPTION OF THE DRAWINGS
FIG. 1 shows an isometric view of the tool storage organizer.
FIG. 2 shows a side view of the tool storage organizer.
FIG. 3 shows a top view of the tool storage organizer.
FIG. 4 shows a front view of the tool storage organizer.
FIG. 5 shows an in-use view of tool storage organizer.
DESCRIPTION OF PREFERRED EMBODIMENTS
Referring now to FIG. 1-6 the present invention features a tool storage organizer system ( 100 ). The system comprises a truck ( 110 ) with cabin rear wall ( 111 ), a tool storage organizer ( 200 ).
A plurality of brackets ( 112 ) are disposed on a cabin wall ( 111 ) of a truck (not shown in Figure) preferably below a pickup rear window ( 110 ), wherein the bracket ( 112 ) has a first arm ( 113 ) with a distal end and proximal end, and a second arm ( 114 ) with a distal end and proximal end, wherein the first arm ( 113 ) are attached to the said wall ( 112 ) via a secure means ( 115 ), wherein the proximal and of the second arm ( 114 ) connected to the proximal end of the first arm ( 113 ) perpendicularly, wherein the second arm ( 114 ) has an opening disposed on the arm. In some embodiments, the wherein the brackets ( 112 ) are made of hard materials, such as metal, metal alloy or hard plastics.
The too organizer ( 200 ) comprises a rectangle back support panel ( 210 ) having a top edge ( 211 ), a bottom edge ( 212 ), a first edge ( 213 ), a second edge ( 214 ), a front surface ( 215 ) and a back surface ( 216 ), wherein the top edge ( 211 ) is parallel to the bottom edge ( 212 ), wherein the first edge ( 213 ) is parallel to the second edge ( 214 ), wherein the top edge ( 211 ) is perpendicular to the first edge ( 213 ), wherein a plurality of holes ( 217 ) are disposed near the top edge ( 211 ), where a grommet ( 218 ) is inserted into each said hole ( 217 ). In some embodiments, the grommet ( 218 ) is made of made of metal, plastic, or rubber. The grommet ( 218 ) is used to prevent tearing or abrasion of the pierced area of the back support panel ( 210 ). In some embodiments, the back support panel ( 200 ) is made of fabrics, cloth or denim
A rod support ( 220 ) is firmly attached to the top edge ( 211 ) of the said back support panel ( 210 ), wherein the rod support ( 220 ) has cylindrical shape with an elongated opening ( 221 ), wherein a hard rod ( 222 ) is inserted into the said elongated opening ( 221 ). In some embodiments, the elongated opening ( 221 ) of the rod support ( 220 ) and hard rod ( 222 ) is circular in cross-section. In some embodiments, the elongated opening ( 221 ) of the rod support ( 220 ) and the hard rod ( 222 ) is oval or rectangle or square in cross-section. The hard rod ( 222 ) is made of hard materials, such as metal, metal alloy, hard wood or Polyvinyl chloride (PVC
An inner layer ( 230 ) comprising a plurality of pockets ( 231 ) is disposed on the said front surface ( 215 ) of the back support panel ( 210 ), wherein the pockets ( 231 ) are adjacent to each other in parallel with top opening ( 232 ) and lower end ( 233 ), wherein the lower end ( 233 ) is aligned with the said bottom edge ( 212 ) of the said back support panel ( 210 ), wherein the top openings of the pockets ( 230 ) in the inner layer ( 230 ) are on the same height below the top edge ( 220 ) of the tool organizer ( 200 ). In some embodiments, the pockets ( 231 ) have the same opening width. In some embodiments, the pockets ( 231 ) have different opening width.
A middle layer ( 240 ) comprising a plurality of pockets ( 241 ) is disposed in front of the inner layer ( 230 ), wherein the pockets ( 241 ) are adjacent to each other in parallel with top opening ( 242 ) and lower end ( 243 ), wherein the lower end ( 243 ) is aligned with the said lower end ( 232 ) of the said ockets ( 231 ) in the inner layer ( 230 ), wherein the top openings of the pockets ( 241 ) in the middle layer ( 240 ) are on the same height below the top openings of the pockets ( 231 ) in the inner layer ( 230 ), wherein the pockets ( 241 ) in the middle layer ( 240 ) has an inner cavity ( 244 ) extending from the said top opening ( 242 ) to the said lower end ( 243 ). In some embodiments, the pockets ( 241 ) have the same opening width ( 245 ). In some embodiments, the pockets ( 241 ) have different opening width ( 245 ). In some embodiments, at least one of the pockets ( 241 ) in the middle layer ( 240 ) has a width ( 245 ) larger than the width ( 235 ) of the pockets ( 231 ) in the inner layer ( 230 ) and at least one of the pockets ( 241 ) in the middle layer ( 240 ) has a width ( 245 ) smaller than the width ( 235 ) of the pockets ( 231 ) in the inner layer ( 230 ). Such unequal width arrangements would be advantageous in properly stong tools of different width.
A front layer ( 250 ) comprising a plurality of pockets ( 251 ) is disposed in front of the middle layer ( 240 ), wherein the pockets ( 251 ) are adjacent to each other in parallel with top opening ( 252 ) and lower end ( 253 ), wherein the lower end ( 253 ) is aligned with the said lower end ( 252 ) of the said pockets ( 231 ) in the middle layer ( 240 ), wherein the top openings of the pockets ( 251 ) in the front layer ( 250 ) are on the same height below the top openings ot the pockets ( 241 ) in the middle layer ( 240 ), wherein the pockets ( 251 ) in the front layer ( 250 ) has an inner cavity ( 254 ) extending from the said top opening ( 252 ) to the said lower end ( 253 ) in some embodiments, the pockets ( 251 ) have the same opening width ( 255 ). In some embodiments, the pockets ( 251 ) have different opening width ( 255 ). In some embodiments, at least one of the pockets ( 251 ) in the front layer ( 250 ) has a width ( 255 ) larger than the width ( 235 ) of the pockets ( 231 ) in the inner layer ( 230 ) and at least one of the pockets ( 251 ) in the front layer ( 250 ) has a width ( 255 ) smaller than the width ( 235 ) of the pockets ( 231 ) in the inner layer ( 230 ). Such unequal width arrangements would be advantageous in property storing toots of different width.
A back layer ( 260 ) comprising a plurality of horizontal pockets ( 261 ) is disposed on the back surface ( 216 ) of the said back support panel ( 210 ), wherein the horizontal pockets ( 261 ) are adjacent to each other in parallel with an inner cavity extending from a first opening ( 262 ) to a second opening ( 263 ), wherein the first openings of all the pockets ( 262 ) in the back layer ( 250 ) are all aligned with the first edge ( 213 ) of the back support panel ( 210 ), wherein the second openings of all the pockets ( 263 ) in the back layer ( 250 ) are all aligned with the second edge ( 214 ) of the back support panel ( 210 ). In some embodiments, the horizontal pockets ( 261 ) in the said back layer ( 260 ) are all the same oval shape in cross-section. The horizontai pockets ( 261 ) have the longer center axis ( 265 ) parallel to the first edge ( 213 ) of the back support panel ( 210 ) and the shorter center axis ( 266 ) perpendicular to the first edge ( 213 ) of the back support panel ( 210 ). In some embodiments, the distance between the first arm ( 113 ) of the said bracket ( 112 ) and the distal end of the second arm ( 114 ) of the said bracket is the same or larger than the width ( 267 ) of the horizontal pockets ( 261 ) such that there is enough space for the bracket to hold the said tool organizer ( 200 ).
The tool storage organizes system ( 100 ) further comprises a plurality of hooks ( 310 ), wherein each of the hooks has a first end ( 311 ) and a second end ( 312 ), wherein the first end ( 311 ) is connected to the said second arm of the bracket ( 112 ), wherein the second arm ( 312 ) is connected to the said grommet ( 218 ).
In some embodiments, the tool storage organizer system ( 100 ) further comprises a plurality of bit slots ( 410 ) disposed on the said front layer ( 250 ), wherein each bit slot comprises a top piece ( 420 ) and bottom piece ( 430 ), wherein the top piece and bottom piece are not connected, wherein both the top piece and the bottom piece are cylindrical shape with the same inner diameter, where both the top piece ( 420 ) and bottom piece ( 430 ) are aligned to the same vertical axis ( 415 ), wherein the vertical axis ( 415 ) is parallel to the first edge of the back support panel ( 210 ). The top piece ( 420 ) has a top opening ( 422 ) and bottom opening ( 424 ), wherein the top opening ( 422 ) of the top piece ( 420 ) is blow the top opening ( 252 ) of the pockets ( 251 ) in the front layer ( 250 ), wherein bottom piece ( 430 ) has a top opening ( 432 ) and bottom end ( 434 ), wherein the bottom end ( 434 ) of the bottom piece ( 430 ) is above the bottom end ( 253 ) of the pockets ( 251 ) in the front layer ( 250 ), wherein the bottom end ( 253 ) of the bottom piece ( 430 ) is sealed. In some embodiments, the bit slots ( 410 ) have the same inner diameter. In some embodiments, the bit slots ( 410 ) have different inner diameter such that bits of different size can be selectably fitted in the proper bit slots. The inner diameter ranges from 1 millimetre to 15 millimetres or ranges from 1/8 inch to 5 inches
As used herein, the term ‘about’ refers to plus or minus 10% of the referenced number.
The disclosures of the following U.S. Patents are incorporated in their entirety by reference herein: U.S. Pat. No. 2,767,895, U.S. Pat. No. 6,763,986, U.S. Pat. No. 7,201,689, U.S. Pat. No. 7,350,681, U.S. Pat. No. 7,891,733, U.S. Patent Application Publication No. 2000/0283899. U.S. Pat. No. D266,195,195, U.S. Pat. No. D447,999 and U.S. Patent No. D487,656.
Various modifications of the invention, in addition to those described herein, will be apparent to those skilled in the art from the foregoing description. Such modifications are also intended to fall within the scope of the appended claims. Each reference cited in the present application is incorporated herein by reference in its entirety.
Although there has been shown and described the preferred embodiment of the present invention, it will be readily apparent to those skilled in the art that modifications may be made thereto which do not exceed the scope of the appended claims. Therefore, the scope of the invention is only to be limited by the following claima.
The reference numbers recited in the below claims are solely for ease of examination of this patent application, and are exemplary, and are not intended in any way to limit the scope of the claims to the particular features having the corresponding reference numbers in the drawings. | The present invention features a tool storage organizer system. The system comprises a storage organzer installed on the back wall of the truck cabin. The organizer has a back support per with multiple layers of pocket disposed in the front and multiple horizontal pockets disposed in the back. The multiple layer pockets in the front have various heights but the same bottom ending levels. A plurality of bits slots are attached to pockets of the out layer pockets. The back support panel has multiple grommets near the to edge, which are used to attach to brackets installed on truck wall through a plurality of hooks. A hard rod is attached to the top edge of the back support panel to keep the support in shape when the back support panel is hanged up. | 1 |
This is a division of application Ser. No. 726,264, filed Apr. 22, 1985 now U.S. Pat. No. 4,740,508.
BACKGROUND OF THE INVENTION
Natarajan et al. in Australian patent application No. 17,203 disclose acylalkylaminocarbonyl substituted amino and imino acid compounds of the formula ##STR2## wherein R 2 is certain aryl, aralkyl, heterocyclo, or alkylene-heterocyclo groups. These compounds possess angiotensin converting enzyme inhibition activity and enkephalinase inhibition activity depending upon the definition of X.
Almquist et al. in U.S. Pat. No. 4,329,473 disclose angiotensin converting enzyme inhibiting compounds of the formula ##STR3## wherein R 2 is aryl, alkyl, alkoxy or benzyloxy.
SUMMARY OF THE INVENTION
This invention is directed to novel compounds of the formula ##STR4## R is hydrogen, lower alkyl, halo substituted lower alkyl, --(CH 2 ) m --cycloalkyl, ##STR5## v is an integer from 2 to 6. R 1 and R 2 are independently selected from hydrogen, lower alkyl, halo substituted lower alkyl, --(CH 2 ) m --cycloalkyl, ##STR6## or R 1 and R 2 taken with the N atom form a heterocyclo ring of the formula ##STR7## R 26 is hydrogen or lower alkyl. X is an amino or imino acid or ester of the formula ##STR8## n is zero, one or two. R 25 is lower alkyl of 1 to 4 carbons or ##STR9## R 7 is hydrogen, lower alkyl, halogen, hydroxy, ##STR10## a 1- or 2-naphthyl of the formula ##STR11## a substituted 1- or 2-naphthyl of the formula ##STR12## a 1- or 2-naphthyloxy of the formula ##STR13## a substituted 1- or 2-naphthyloxy of the formula ##STR14## a 1- or 2-naphthylthio of the formula ##STR15## or a substituted 1- or 2-naphthylthio of the formula ##STR16## R 8 is halogen, ##STR17## -O-lower alkyl, a 1- or 2-naphthyloxy of the formula ##STR18## a substituted 1- or 2-naphthyloxy of the formula ##STR19## a 1- or 2-naphthylthio of the formula ##STR20## or a substituted 1- or 2-naphthylthio of the formula ##STR21## R 9 is keto, ##STR22## R 10 is halogen or --Y--R 16 . R 11 , R' 11 , R 12 and R' 12 are independently selected from hydrogen and lower alkyl or R' 11 , R 12 and R' 12 are hydrogen and R 11 is ##STR23## R 13 is lower alkyl of 1 to 4 carbons, lower alkoxy of 1 to 4 carbons, lower alkylthio of 1 to 4 carbons, chloro, bromo, fluoro, trifluoromethyl, hydroxy, phenyl, phenoxy, phenylthio, or phenylmethyl.
R 14 is lower alkyl of 1 to 4 carbons, lower alkoxy of 1 to 4 carbons, lower alkylthio of 1 to 4 carbons, chloro, bromo, fluoro, trifluoromethyl or hydroxy.
m is zero, one, two, three, or four.
p is one, two or three provided that p is more than one only if R 13 or R 14 is methyl, methoxy, chloro, or fluoro.
R 15 is hydrogen or lower alkyl of 1 to 4 carbons.
Y is oxygen or sulfur.
R 16 is lower alkyl of 1 to 4 carbons, ##STR24## or the R 16 groups join to complete an unsubstituted 5- or 6-membered ring or said ring in which one or more of the carbons has a lower alkyl of 1 to 4 carbons or a di(lower alkyl of 1 to 4 carbons) substituent.
R 4 is hydrogen, lower alkyl, ##STR25## R 5 is hydrogen, lower alkyl, ##STR26## r is an integer form 1 to 4 R 19 is lower alkyl, benzyl or phenethyl.
R 20 is hydrogen, lower alkyl, benzyl or phenethyl.
R 3 is hydrogen, lower alkyl, ##STR27## halo substituted lower alkyl, --(CH 2 ) m --cycloalkyl, ##STR28## wherein m, R 14 , p and r are as defined above. R 6 is hydrogen, lower alkyl, benzyl, benzhydryl, ##STR29## or a salt forming ion. R 17 is hydrogen, lower alkyl, cycloalkyl, or phenyl.
R 18 is hydrogen, lower alkyl, lower alkoxy or phenyl.
R 21 and R 22 are independently selected from hydrogen and lower alkyl.
R 23 is lower alkyl.
R 24 is hydrogen, lower alkyl, ##STR30##
DETAILED DESCRIPTION OF THE INVENTION
This invention in its broadest aspects relates to the amino and imino acid and ester compounds of formula I and to compositons and the method of using such compounds as pharmaceutical agents.
The term lower alkyl used in defining various symbols refers to straight or branched chain radicals having up to seven carbons. The preferred lower alkyl groups are up to four carbons with methyl and ethyl most preferred. Similarly the terms lower alkoxy and lower alkylthio refer to such lower alkyl groups attached to an oxygen or sulfur.
The term cycloalkyl refers to saturated rings of 4 to 7 carbon atoms with cyclopentyl and cyclohexyl being most preferred.
The term halogen refers to chloro, bromo and fluoro. The term halo substituted lower alkyl refers to such alkyl groups in which one or more carbons have been replaced by a halogen, i.e., CF 3 , CH 2 Cl 3 , CH 2 Br, etc.
The symbols ##STR31## represent that the alkylene bridge is attached to an available carbon atom.
The compounds of formula I are obtained by treating an amine of the formula ##STR32## particularly the hydrochloride salt thereof, wherein R 6 in the definition of X is an easily removable protecting group such as benzyl, benzhydryl, t-butyl, etc., with p-nitrophenyl chloroformate or phosgene in the presence of N-methylmorpholine followed by treatment with an amine of the formula ##STR33## Alternatively, the amine of formula III could first be treated with p-nitrophenyl chloroformate or phosgene and the resultant product then treated with the amino intermediate of formula II.
The compounds of formula I wherein R 1 and R 2 are both hydrogen can be prepared by employing ammonia as the reagent of formula III in the first procedure described above.
Removal of the R 6 protecting group, for example by hydrogenation when R 6 is benzyl, yields the acid products of formula I, i.e., R 6 is hydrogen.
The amino intermediate of formula II can be prepared as follows. An amino acid derivative of the formula ##STR34## wherein R 30 is t-butyl, --CH 2 --CCl 3 , benzhydryl, ##STR35## or --(CH 2 ) 2 --Si(CH 3 ) 3 is treated sequentially with isobutylchloroformate and a tertiary base such as N-methylmorpholine followed by reaction with diazomethane and treatment with hydrogen chloride to give ##STR36## The chloride of formula V is treated with a substituted benzylamine of the formula ##STR37## to give ##STR38## Removal of the benzyl protecting group, for example, by hydrogenation gives ##STR39##
The amine of formula VIII, particularly the p-toluenesulfonic acid salt thereof, is treated with the chlorocarbonylamine of the formula ##STR40## in the presence of a base such as triethylamine, wherein R 6 in the definition of X is an easily removable protecting group, followed by removal of the t-butyl, benzhydryl, --CH 2 --CCl 3 , --CH 2 ) 2 --Si(CH 3 ) 3 , or ##STR41## R 30 group, for example by treating with hydrogen chloride when R 30 is t-butyl, to yield the amino intermediate of formula II.
In the above reactions, if R is hydrogen then the N-atom is protected, for example by a t-butoxycarbonyl group which can be removed by hydrogenation following completion of the reaction. Also, if R 26 is hydrogen then that N-atom is protected, for example, by a benzyloxycarbonyl group which can be removed following completion of the reaction. Similarly, if any or all of R, R 1 , R 2 , R 3 and R 5 are ##STR42## then the hydroxyl, amino, imidazolyl, mercaptan or guanidinyl function should be protected during the reaction. Suitable protecting groups include benzyloxycarbonyl, t-butoxycarbonyl, benzyl, trimethylsilylethylcarbonyl, benzhydryl, trityl, etc., and nitro in the case of guanidinyl. The protecting group is removed by hydrogenation, treatment with acid, or other known methods following completion of the reaction.
The ester products of formula I wherein R 6 is ##STR43## may be obtained by employing the amino or imino acid ester of formula III in the above reactions with such ester group already in place.
The ester products of formula I wherein R 6 is ##STR44## can also be obtained by treating the product of formula I wherein R 6 is hydrogen with a molar excess of the compound of the formula ##STR45## wherein L is a leaving group such as chlorine, bromine, tolylsulfonyl, etc.
The ester products of formula I wherein R 6 is ##STR46## can be prepared by treating the product of formula I wherein R 6 is hydrogen with a molar excess of the compound of the formula ##STR47##
The ester products of formula I wherein R 6 is ##STR48## can be prepared by coupling the product of formula I wherein R 6 is hydrogen with a molar excess of the compound of the formula ##STR49## or the formula ##STR50## in the presence of a coupling agent such as dicyclohexylcarbodiimide and the optional presence of a catalyst such as dimethylaminopyridine followed by removal of the hydroxyl protecting group.
Similarly, the ester products of formula I wherein R 6 is ##STR51## can be prepared by coupling the product of formula I wherein R 6 is hydrogen with a molar excess of the compound of formula
HO--CH.sub.2 --CH.sub.2 --N--(CH.sub.3).sub.2 (XIV)
or the formula ##STR52## in the presence of a coupling agent such as dicylohexylcarbodiimide and the optional presence of a catalyst such as dimethylaminopyridine.
The products of formula I wherein R 7 is amino may be obtained by reducing the corresponding products of formula I wherein R 7 is azido.
Preferred compounds of this invention are those of formula I wherein:
X is ##STR53## R 6 is hydrogen, straight or branched chain lower alkyl of 1 to 4 carbons, or an alkali metal salt ion.
R 4 is cyclohexyl or phenyl and R 5 is hydrogen.
R 4 is hydrogen and R 5 is methyl, ##STR54## R 7 is hydrogen, cyclohexyl, lower alkoxy of 1 to 4 carbons, ##STR55## R 13 is methyl, methoxy, methylthio, Cl, Br, F, or hydroxy. m is zero, one or two.
t is two or three.
R is straight or branched chain lower alkyl of 1 to 4 carbons.
R 1 and R 2 are independently selected from straight or branched chain lower alkyl of 1 to 4 carbons or R 1 is cyclohexyl and R 2 is hydrogen or R 1 and R 2 taken together with the N atom to which they are attached complete a heterocyclo ring of the formula ##STR56## wherein R 26 is hydrogen or straight or branched chain lower alkyl of 1 to 4 carbons.
R 3 is straight or branched chain lower alkyl of 1 to 4 carbons, ##STR57## R 14 is methyl, methoxy, methylthio, Cl, Br, F, or hydroxy.
Most preferred compounds of this invention are those of formula I wherein:
X is ##STR58## R is methyl. R 6 is hydrogen or an alkali metal salt ion.
R 1 and R 2 are each methyl or R 1 is cyclohexyl and R 2 is hydrogen or R 1 and R 2 taken together with the N atom to which they are attached complete a heterocyclo ring of the formula ##STR59##
The compounds of formula I wherein R 6 is hydrogen form salts with a variety of inorganic or organic bases. The nontoxic, pharmaceutically acceptable salts are preferred, although other salts are also useful in isolating or purifying the product. Such pharmaceutically acceptable salts include alkali metal salts such as sodium, potassium or lithium, alkaline earth metal salts such as calcium, or magnesium, and salts derived from amino acids such as arginine, lysine, etc. The salts are obtained by reacting the acid form of the compound with an equivalent of the base supplying the desired ion in a medium in which the salt precipitates or in aqueous medium and then lyophilizing.
The compounds of formula I when R 3 is other than hydrogen contain an asymmetric center as represented by the * in formula I. Thus, the compounds of formula I can exist in diastereomeric forms or in mixtures thereof. The above described processes can utilize racemates, enantiomers or diastereomers as starting materials. When diastereomeric products are prepared, they can be separated by conventional chromatographic or fractional crystallization methods.
The products of formula I wherein the imino acid ring is monosubstituted give rise to cis-trans isomerism. The configuration of the final product will depend upon the configuration of the R 7 , R 8 and R 9 substituent in the starting material of formula III.
The compounds of formula I, and the pharmaceutically acceptable salts thereof, are hypotensive agents. They inhibit the conversion of the decapeptide angiotensin I to angiotensin II and, therefore, are useful in reducing or relieving angiotensin related hypertension. The action of the enzyme renin on angiotensinogen, a pseudoglobulin in blood plasma, produces angiotensin I. Angiotensin I is converted by angiotensin converting enzyme (ACE) to angiotensin II. The latter is an active pressor substance which has been implicated as the causative agent in several forms of hypertension in various mammalian species, e.g., humans. The compounds of this invention intervene in the angiotensinogen→(renin)→angiotensin I→angiotensin II sequence by inhibiting angiotensin converting enzyme and reducing or eliminating the formation of the pressor substance angiotensin II. Thus by the administration of a composition containing one (or a combination) of the compounds of this invention, angiotensin dependent hypertension in a species of mammal (e.g., humans) suffering therefrom is alleviated. A single dose, or preferably two to four divided daily doses, provided on a basis of about 0.1 to 100 mg., preferably about 1 to 50 mg., per kg. of body weight per day is appropriate to reduce blood pressure. The substance is preferably administered orally but parenteral routes such as the subcutaneous, intramuscular, intravenous or intraperitoneal routes can also be employed.
The compounds of this invention can also be formulated in combination with a diuretic for the treatment of hypertension. A combination product comprising a compound of this invention and a diuretic can be administered in an effective amount which comprises a total daily dosage of about 30 to 600 mg., preferably about 30 to 330 mg. of a compound of this invention, and about 15 to 300 mg., preferably about 15 to 200 mg. of the diuretic, to a mammalian species in need thereof. Exemplary of the diuretics contemplated for use in combination of this invention are the thiazide diuretics, e.g., chlorothiazide, hydrochlorothiazide, flumethiazide, hydroflumethiazide, bendroflumethiazide, methyclothiazide, trichloromethiazide, polythiazide or benzthiazide as well as ethacrynic acid, ticrynafen, chlorthalidone, furosemide, musolimine, bumetanide, triamterene, amiloride and spironolactone and salts of such compounds.
The compounds of formula I can be formulated for use in the reduction of blood pressure in compositions such as tablets, capsules or elixirs for oral administration, or in sterile solutions or suspensions for parenteral administration. About 10 to 500 mg. of a compound of formula I is compounded with physiologically acceptable vehicle, carrier, excipient, binder, preservative, stabilizer, flavor, etc., in a unit dosage form as called for by accepted pharmaceutical practice. The amount of active substance in these compositions or preparations is such that a suitable dosage in the range indicated is obtained.
The compounds of formula I wherein X is ##STR60## also possess enkephalinase inhibition activity and are useful as analgesic agents. Thus, by the administration of a composition containing one or a combination of such compounds of formula I or a pharmaceutically acceptable salt thereof, pain is alleviated in the mammalian host. A single dose, or preferably two to four divided daily doses, provided on a basis of about 0.1 to about 100 mg. per kilogram of body weight per day, preferably about 1 to about 50 mg. per kilogram per day, produces the desired analgesic activity. The composition is preferably administered orally but parenteral routes such as subcutaneous can also be employed.
The following examples are illustrative of the invention. Temperatures are given in degrees centigrade.
EXAMPLE 1
1-[[Methyl[(S)-2-oxo-4-phenyl-3-[(1-piperidinylcarbonyl)amino]butyl]amino]carbonyl]-L-proline
(a)
(S)-[3-Chloro-2-oxo-1-(phenylmethyl)propyl]carbamic acid, 1,1-dimethylethyl ester
To a stirred solution of N-[(1,1-dimethylethoxy)carbonyl]-L-phenylalanine (26.5 g., 100 mmole) in tetrahydrofuran (150 ml.) at -20° is added isobutylchloroformate (13 ml., 100 mmole). N-Methylmorpholine (11 ml., 100 mmole) is then added in drops. The solution is stirred between -15° C. and -20° C. for fifteen minutes and then filtered. Tetrahydrofuran (25 ml.) is used for the washings. The filtrate is added to a cold (ice bath) ethereal solution of diazomethane in drops. After the addition is over, the ice bath is removed, and the reaction mixture is stirred at ambient temperature for 2 hours. Nitrogen is blown over the solution and the volume is reduced to 400 ml. The reaction mixture is then stirred in an ice bath and hydrogen chloride in acetic acid (2N, 55 ml.) is added in drops. After the addition is over, the ice bath is removed and the reaction mixture is stirred for 15 minutes at room temperature. The reaction mixture is evaporated in vacuo and the residue on attempted dissolution in ether affords 6.2 g. of (S)-[3-chloro-2-oxo-1-(phenylmethyl)propyl]carbamic acid, 1,1-dimethylethyl ester; m.p. 104°-105°; [α] D 22 =+20.3° (c=2, chloroform). The mother liquor on concentration and after crystallization from ether/hexane gives an additonal 17.65 g. of product.
(b)
(S)-[3-[Methyl(phenylmethyl)amino]-2-oxo-1-(phenylmethyl)propyl]carbamic acid, 1,1-dimethylethyl ester, p-toluenesulfonate salt
A solution of (S)-[3-chloro-2-oxo-1-(phenylmethyl)propyl]carbamic acid, 1,1-dimethylethyl ester (6.43 g., 21.6 mmole), sodium bicarbonate (2.17 g., 25.9 mmole), sodium iodide (1.62 g., 11.0 mmole) and benzylmethylamine (2.76 ml., 2.14 mmole) in dimethylformamide (60 ml.) is stirred at room temperature for 4 hours. The resulting solution is concentrated and partitioned between ether and water. The ether layer is washed with water (twice) and extracted with 1N hydrochloric acid (five times). The combined extracts are made basic using sodium bicarbonate and extracted with ethyl acetate. The ethyl acetate extracts are dried (MgSO 4 ) and concentrated. The crude crystalline residue is dissolved in ether and a solution of p-toluenesulfonic acid (3.0 g., 28 mmole) in ethyl acetate is added. The resulting pink crystals are triturated with hot ethyl acetate and collected to give 6.5 g. of (S)-[3-[methyl(phenylmethyl)amino]-2-oxo-1-(phenylmethyl)propyl]carbamic acid, 1,1-dimethylethyl ester, p-toluenesulfonate salt as a white solid; m.p. 150°-152°.
(c)
(S)-[3-(Methylamino)-2-oxo-1-(phenylmethyl)propyl]carbamic acid, 1,1-dimethylethyl ester, hydrochloride salt
A mixture of the p-toluenesulfonate salt product from part (b) (6.5 g., 11.7 mmole) and palladium hydroxide (20%) in methanol is hydrogenated at atmospheric pressure and room temperature for 1.5 hours. The resulting solution is filtered, concentrated, and triturated with ether to give 4.75 g. of a white crystalline solid. A portion of this material is partitioned between ethyl acetate and 10% sodium bicarbonate. The organic layer is treated with hydrochloric acid/ether to give the crude hydrochloride salt as blue-green solid. Recrystallization from methanol/ether gives (S)-[3-(methylamino)-2-oxo-1-(phenylmethyl)propyl]carbamic acid, 1,1-dimethylethyl ester, hydrochloride salt; m.p. 164°-169°.
(d)
1-[[[(S)-3-[[(1,1-Dimethylethoxy)carbonyl]amino]-2-oxo-4-phenylbutyl]methylamino]carbonyl]L-proline, phenylmethyl ester
N-Methylmorpholine (0.46 ml., 4.2 mmole) is added to a stirring suspension of L-proline, phenylmethyl ester, hydrochloride salt (0.39 g., 1.6 mmole) in methylene chloride (dry, distilled) at -40° followed by phosgene in benzene (approximately 1M, 2.5 ml., 2.5 mmole). The mixture is stirred at -30° for one hour. The ice bath is removed and the mixture is stirred for an additional hour. The mixture is then concentrated in vacuo and diluted with methylene chloride. (S)-[3-(Methylamino)-2l -oxo-1-(phenylmethyl)propyl]carbamic acid, 1,1-dimethylethyl ester, hydrochloride salt (0.34 g., 1.0 mmole) is added to the solution and the mixture is stirred overnight. The resulting solution is diluted with methylene chloride and washed with 1N hydrochloric acid and 10% sodium bicarbonate, dried (MgSO 4 ) and concentrated. The crude product (0.61 g.) is combined with material from a previous run (0.56 g.) and chromatographed on LPS-1 silica gel using hexane:ethyl acetate (2:1) as the eluant. The combined fractions are rechromatographed on LPS-1 using ether:ethyl acetate (10:1) as eluent. Fractions containing the desired product (R f =0.43, hexane:ethyl acetate, 1:1) are combined and concentrated to give 0.26 g. of 1-[[[(S)-3-[[(1,1-dimethylethoxy)carbonyl]amino]-2-oxo-4-phenylbutyl]methylamino]carbonyl]-L-proline, phenylmethyl ester.
(e)
1-[[[(S)-3-Amino-2-oxo-4-phenylbutyl]methylamino]carbonyl]-L-proline, phenylmethyl ester
A solution of 1-[[[(S)-3-[[(1,1-dimethylethoxy)carbonyl]amino]-2-oxo-4-phenylbutyl]methylamino]carbonyl]-L-proline, phenylmethyl ester (7.12 g., 13.6 mmole) is stirred in a saturated solution of hydrochloric acid/ethyl acetate for one hour. The resulting precipitate is collected and washed with ethyl acetate to give 5.63 g. of 1-[[[(S)-3-amino-2-oxo-4-phenylbutyl]methylamino]carbonyl]-L-proline, phenylmethyl ester; m.p. 174°-175°; [α] D 25 =+16.20°. TLC (silica gel; chloroform:methanol:acetic acid, 4:1:1) R f =0.60.
(f)
1-[[[(S)-3-[[(4-Nitrophenoxy)carbonyl]amino]2-oxo-4-phenylbutyl]methylamino]carbonyl]-L-proline, phenylmethyl ester
N-Methylmorpholine (2.0 ml., 18.0 mmole) is added over a period of 5 minutes to a cooled (-30°) mixture of 1-[[[(S)-3-amino-2-oxo-4-phenylbutyl]methylamino]carbonyl]-L-proline, phenylmethyl ester (3.6 g., 8.0 mmole) and p-nitrophenyl chloroformate (1.6 g., 8.0 mmole) in methylene chloride (30 ml.). The resulting mixture is stirred for 15 more minutes in the cold bath and 20 minutes after removal of the bath. The mixture is washed with water (2×), 1N hydrochloric acid, 10% sodium bicarbonate (4×), and 1N hydrochloric acid. The organic layer is dried (MgSO 4 ) and concentrated to a red oil. The crude material is filtered through silica gel using chloroform and chloroform:ethyl acetate (1:1) as eluants. Fractions containing the desired product (R f =0.57, ethyl acetate) are combined and concentrated. The residue is dissolved in methanol and cooled. Crystals are filtered off and the filtrate is concentrated to give 2.95 g. of 1-[[[(S)-3-[[(4-nitrophenoxy)carbonyl]amino]-2-oxo-4-phenylbutyl]methylamino]carbonyl]-L-proline, phenylmethyl ester as a yellow oil.
(g)
1-[[Methyl[(S)-2-oxo-4-phenyl-3-[(1-piperidinylcarbonyl)amino]butyl]amino]carbonyl]-L-proline, phenylmethyl ester
A solution of piperidine (0.5 ml., 5.2 mmole) in toluene (15 ml.) is added dropwise over five minutes to a cooled solution (0°) of 1-[[[(S)-3-[[(4-nitrophenoxy)carbonyl]amino]-2-oxo-4-phenylbutyl]methylamino]carbonyl]-L-proline, phenylmethyl ester (1.48 g., 2.6 mmole) in toluene (40 ml.) in an ice bath. The solution immediately turns yellow. The resulting solution is stirred at room temperature for 30 minutes, diluted with water and washed sequentially with 1N hydrochloric acid, 10% sodium bicarbonate, and water. The organic layer is dried (MgSO 4 ) and concentrated. The residue (1.5 g.) is chromatographed on LPS-1 silica gel using an elution gradient of 50→100% ethyl acetate in hexane. Fractions containing the desired product (R f =0.54 traces at R f =0.4, 0.6, ethyl acetate) are combined and concentrated to a yellow oil (0.85 g.). The residue is then purified by preparative layer chromatography using ethyl acetate as eluant to give 0.81 g. of 1-[[methyl[(S)-2-oxo-4-phenyl-3-[(1-piperidinylcarbonyl)amino]butyl]amino]carbonyl]-L-proline, phenylmethyl ester as a pale yellow oil.
(h)
1-[[Methyl[(S)-2-oxo-4-phenyl-3-[(1-piperidinylcarbonyl)amino]butyl]amino]carbonyl]-L-proline
A suspension of the phenylmethyl ester product from part (g) (0.8 g., 1.5 mmole) in methanol and palladium hydroxide (20% on carbon) is hydrogenated at room temperature and atmospheric pressure for 30 minutes. The mixture is filtered, the solids are rinsed with methanol, and the filtrate is concentrated to give 0.42 g. of yellow oil. The residue is chromatographed on LPS-1 silica gel using an elution gradient of 3→10% acetic acid in chloroform. Fractions containing the desired material are combined and concentrated. The residue is dissolved in methanol/water, filtered, concentrated (methanol removed) and lyophilized to give a white solid. The material is rechromatographed on CC-4 silica gel using ethyl acetate as the eluant. Fractions containing the desired produced are combined and lyophilized from water/dioxane to give 1-[[methyl[(S)-2-oxo-4-phenyl-3-[(1-piperidinylcarbonyl)amino]butyl]amino]carbonyl]-L-proline as a white solid; m.p. 69°-72°; [α] D 25 =-37° (c=0.2, methanol). TLC (silica gel; toluene:acetic acid, 4:1) R f =0.18.
Anal. calc'd. for C 23 H 32 N 4 O 5 .1H 2 O: C, 59.72; H, 7.41; N, 12.11. Found: C, 59.86; H, 7.07; N, 11.67.
EXAMPLE 2
1-[[Methyl[(S)-3-[(4-morpholinylcarbonyl)amino]-2-oxo-4-phenylbutyl]amino]carbonyl]-L-proline
(a)
1-[[Methyl[(S)-3-[(4-morpholinylcarbonyl)amino]-2-oxo-4-phenylbutyl]amino]carbonyl]-L-proline, phenylmethyl ester
Morpholine (1 ml., 11.4 mmole) is added to a stirring solution of 1-[[[(S)-3-[[(4-nitrophenoxy)carbonyl]amino]-2-oxo-4-phenylbutyl]methylamino]carbonyl]-L-proline, phenylmethyl ester (0.9 g., 1.58 mmole) in toluene at 0° in one portion. The reaction mixture turns yellow in 15 minutes and TLC indicates complete loss of starting material after 30 minutes. The resulting solution is washed sequentially with water, 1N hydrochloric acid, and 10% sodium bicarbonate. The organic layer is dried (MgSO 4 ) and concentrated. The crude product is purified by preparative layer chromatography to give 0.26 g. of 1-[[methyl[(S)-3-[(4-morpholinylcarbonyl)amino]carbonyl]-2-oxo-4-phenylbutyl]amino]carbonyl]-L-proline, phenylmethyl ester as a yellow oil. TLC (ethyl acetate) R f =0.18.
(b)
1-[[Methyl[(S)-3-[(4-morpholinylcarbonyl)amino]-2-oxo-4-phenylbutyl]amino]carbonyl]-L-proline
A solution of the phenylmethyl ester product from part (a) (0.26 g., 0.48 mmole) in methanol containing palladium hydroxide on carbon is hydrogenated at room temperature and atmospheric pressure for 30 minutes. The mixture is filtered (Celite), the solids rinsed with methanol, and the filtrate is concentrated. The residue is triturated with ether and dried under vacuum to give 0.16 g. of 1-[[methyl[(S)-3-[(4-morpholinylcarbonyl)amino]-2-oxo-4-phenylbutyl]amino]carbonyl]-L-proline as a white solid; m.p. 75°-90°; [α] D =-38° (c=0.9, methanol). TLC (silica gel; chloroform:methanol:acetic acid, 4:1:1) R f =0.8, trace at R f =0.2.
Anal. calc'd. for C 22 H 30 N 4 O 6 .0.71H 2 O: C, 57.54; H, 6.89; N, 12.20. Found: C, 57.54; H, 6.78; N, 11.97.
EXAMPLE 3
1-[[[(S)-3-[[(Cylohexylamino)carbonyl]amino]-2-oxo-4-phenylbutyl]methylamino]carbonyl]-L-proline
(a)
1-[[[(S)-3-[[((Cyclohexylamino)carbonyl]amino]-2-oxo-4-phenylbutyl]methylamino]carbonyl-L-proline, phenylmethyl ester
Cyclohexylamine (1 ml., 8.7 mmole) is added to a cold (0°) solution of 1-[[[(S)-3-[[(4-nitrophenoxy)carbonyl]amino]-2-oxo-4-phenylbutyl]methylamino]carbonyl]-L-proline, phenylmethyl ester (0.9 g., 1.58 mmole) in toluene in one portion. The solution turns yellow immediately and TLC indicates all starting material has been consumed. The resulting solution is washed sequentially with water, 1N hydrochloric acid, and 10% sodium bicarbonate. The organic layer is dried (MgSO 4 ) and concentrated to a pale yellow oil. The crude product is purified (2×) by preparative layer chromatography using ethyl acetate as eluant to give 0.31 g. of 1-[[[(S)-3-[[(cyclohexylamino)carbonyl]amino]-2-oxo-4-phenylbutyl]methylamino]carbonyl]-L-proline, phenylmethyl ester as a clear, colorless salt.
(b)
1-[[[(S)-3-[[(Cyclohexylamino)carbonyl]amino]-2-oxo-4-phenylbutyl]methylamino]carbonyl]-L-proline
A suspension of the phenylmethyl ester from part (a) (0.31 g., 0.56 mmole) in methanol and palladium hydroxide on carbon is hydrogentated at room temperature and atmospheric pressure for 30 minutes. The resulting mixture is filtered (Celite), the solids washed with methanol, and the filtrate concentrated to give 0.27 g. of a clear glass. The residue is triturated with ether and dried under vacuum to give 0.175 g. of 1-[[[(S)-3-[[(cyclohexylamino)carbonyl]amino]-2-oxo-4-phenylbutyl]methylamino]carbonyl]-L-proline; m.p. 75°-110°; [α] D =27° (c=1, methanol). TLC (silica gel; toluene:acetic acid, 4:1) R f =0.18.
Anal. calc'd. for C 24 H 34 N 4 O 5 .0.8H 2 O: C, 60.93; H, 7.59; N, 11.84. Found: C, 60.93; H, 7.40; N, 11.89.
EXAMPLE 4
1-[[Methyl[(S)-3-[[(4-methyl-1-piperazinyl)carbonyl]amino]-2-oxo-4-phenylbutyl]amino]carbonyl]-L-proline, dihydrochloride
(a)
1-[[Methyl[(S)-3-[[(4-methyl-1-piperazinyl)carbonyl]amino]-2-oxo-4-phenylbutyl]amino]carbonyl]-L-proline, phenylmethyl ester
N-Methyl piperazine (1 ml., 9.0 mmole) is added to a cooled (0°) solution of 1-[[[(S)-3-[[(4-nitrophenoxy)carbonyl]amino]-2-oxo-4-phenylbutyl]methylamino]carbonyl]-L-proline, phenylmethyl ester (1.06 g., 1.8 mmole) in toluene (20 ml.) in an ice bath in one portion. The resulting solution is stirred for an additional 45 minutes as it warms to room temperature. The solution is washed sequentially with water and 10% sodium bicarbonate, dried (MgSO 4 ), and concentrated. The crude product is chromatographed on LPS-1 silica gel eluting with a solution of ethyl acetate:pyridine:acetic acid:water (300:20:6:11→100:20:6:11). Fractions containing the desired product are combined and concentrated to give 0.3 g. of 1-[[methyl[(S)-3-[[(4-methyl-1-piperazinyl)carbonyl]amino]-2-oxo-4-phenylbutyl]amino]carbonyl]-L-proline, phenylmethyl ester; TLC (silica gel; ethyl acetate:pyridine:acetic acid:water, 100:20:6:11) R f =0.26.
(b)
1-[[Methyl[(S)-3-[[(4-methyl-1-piperazinyl)carbonyl]amino]-2-oxo-4-phenylbutyl]amino]carbonyl]-L-proline, dihydrochloride
A solution of the phenylmethyl ester product from part (a) (0.3 g., 0.54 mmole) in methanol (20 ml.) is hydrogenated for one hour at room temperature and atmospheric pressure using palladium hydroxide as catalyst. The resulting mixture is filtered and concentrated to a yellow oil. The crude product is dissolved in water and washed with ether, ethyl acetate, and chloroform. The aqueous layer is treated with 1N hydrochloric acid (0.5 ml.) and chromatographed on HP-20 using a 0.01N hydrochloric acid:methanol (100→0%) gradient. Fractions containing the desired product are combined, concentrated and lyophilized to give 0.042 g. of 1-[[methyl[(S)-3-[[(4-methyl-1-piperazinyl)carbonyl]amino]-2-oxo-4-phenylbutyl]amino]carbonyl]-L-proline, dihydrochloride as a bright yellow solid; m.p. (95) 101°-106°; [α] D =-16° (c=0.4, methanol). TLC (silica gel; n-butanol:acetic acid:water:ethyl acetate, 1:1:1:1) R f =0.37.
Anal. calc'd. for C 23 H 33 N 5 O 5 .2HCl.1.7H 2 O: C, 49.06; H, 6.87; N, 12.44; Cl, 12.59. Found: C, 49.02; H, 7.08; N, 12.29; Cl, 12.37.
EXAMPLE 5
1-[[[(S)-3-[[(Dimethylamino)carbonyl]amino]-2-oxo-4-phenylbutyl]methylamino]carbonyl-L-proline
(a)
1-[[[(S)-3-[[(Dimethylamino)carbonyl]amino]-2-oxo-4-phenylbutyl]methylamino]carbonyl]-L-proline, phenylmethy ester
Diisopropylethylamine (1.5 ml., 8.75 mmole) is added to a cooled (0°) solution of 1-[[[(S)-3-[[(4-nitrophenoxy)carbonyl]amino]-2-oxo-4-phenylbutyl]methylamino]carbonyl]-L-proline, phenylmethyl ester (1.0 g., 1.75 mmole) and dimethylamine hydrochloride (0.71 g., 8.75 mmoles) in toluene (50 ml.) in one portion. The resulting yellow solution is stirred in a closed system at 0° for 4 hours and for 2 hours following removal of the ice bath. The resulting mixture is washed sequentially with water, 10% sodium bicarbonate, 1N hydrochloric acid, and 10% sodium bicarbonate. The solution is dried (MgSO 4 ) and concentrated to a pale yellow oil which is chromatographed on LPS-1 silica gel using 50→100% ethyl acetate in hexane as eluant. Fractions containing the desired product are combined and concentrated to give 0.68 g. of 1-[[[(S)-3-[[(dimethylamino)carbonyl]amino]-2-oxo-4-phenylbutyl]methylamino]carbonyl]-L-proline, phenylmethyl ester as a clear oil. TLC (silica gel, ethyl acetate) R f =0.2.
(b)
1-[[[(S)-3-[[(Dimethylamino)carbonyl]amino]-2-oxo-4-phenylbutyl]methylamino]carbonyl]-L-proline
A solution of the phenylmethyl ester product from part (a) (0.68 g., 1.37 mmole) in methanol is hydrogenated at room temperature and atmospheric pressure for three hours using palladium hydroxide on carbon as catalyst. The resulting solution is filtered and concentrated to a white foam which is lyophilized from dioxane/water to give 0.5 g. of 1-[[[(S)-3-[[(dimethylamino)carbonyl]amino]-2-oxo-4-phenylbutyl]methylamino]carbonyl]-L-proline; m.p. (60) 74°-104°; [α] D =-38.6° (c=1.0, methanol). TLC (silica gel; chloroform:methanol:acetic acid, 4:1:1) R f =0.73, trace at 0.33.
Anal. calc'd. for C 22 H 28 N 4 O 5 .1.1H 2 O: C, 56.62; H, 7.17; N, 13.20. Found: C, 56.63; H, 7.25; N, 13.14.
EXAMPLES 6-30
Following the procedure of Examples 1-5, the amine shown in Col. I is treated with 4-nitrophenyl chloroformate and then reacted with the amine shown in Col. II to yield the ester product shown in Col. III. Removal of the R 6 ester group yields the corresponding acid product.
Col. I Col. II Col. III ##STR61## ##STR62## ##STR63## Example R.sub.3 ##STR64## R X 6 ##STR65## NH.sub.2 CH.sub.3 ##STR66## 7 ##STR67## NHCH.sub.3 CH.sub.3 ##STR68## 8 ##STR69## N(C.sub.2 H.sub.5).sub.2 CH.sub.3 ##STR70## 9 ##STR71## ##STR72## CH.sub.3 ##STR73## 10 ##STR74## ##STR75## CH.sub.3 ##STR76## 11 ##STR77## ##STR78## CH.sub.3 ##STR79## 12 ##STR80## ##STR81## CH.sub.3 ##STR82## 13 ##STR83## ##STR84## CH.sub.3 ##STR85## 14 H.sub.5 C.sub.2H.sub.2 C ##STR86## CH.sub.3 ##STR87## 15 ##STR88## ##STR89## CH.sub.3 ##STR90## 16 ##STR91## ##STR92## CH.sub.3 ##STR93## 17 ##STR94## ##STR95## CH.sub.3 ##STR96## 18 ##STR97## ##STR98## CH.sub.3 ##STR99## 19 ##STR100## ##STR101## ##STR102## ##STR103## 20 ##STR104## ##STR105## ##STR106## ##STR107## 21 ##STR108## ##STR109## ##STR110## ##STR111## 22 ##STR112## ##STR113## ##STR114## ##STR115## 23 ##STR116## ##STR117## CH.sub.3 ##STR118## 24 ##STR119## ##STR120## CH.sub.3 ##STR121## 25 ##STR122## ##STR123## CH.sub.3 ##STR124## 26 ##STR125## N(CH.sub.3).sub.2 CH.sub.3 ##STR126## 27 ##STR127## ##STR128## CH.sub.3 ##STR129## 28 ##STR130## ##STR131## CH.sub.3 ##STR132## 29 ##STR133## ##STR134## CH.sub.3 ##STR135## 30 ##STR136## ##STR137## CH.sub.3 ##STR138##
The R 3 protecting group shown in Example 17, the R 1 protecting groups shown in Examples 15 and 16, the R protecting groups shown in Examples 21 and 22, the R 5 protecting group shown in Example 27, and the R 26 protecting group shown in Example 19 are removed as the last step in the synthesis. The R 6 ester groups shown in Examples 28 to 30 are not removed.
EXAMPLE 31
1000 tablets each containing the following ingredients:
______________________________________1-[[Methyl[(S)--2-oxo-4-phenyl-3- 100 mg.[(1-piperidinylcarbonyl)amino]-butyl]amino]carbonyl]-L-prolineCornstarch 50 mg.Gelatin 7.5 mg.Avicel(microcrystalline cellulose) 25 mg.Magnesium stearate 2.5 mg. 185 mg.______________________________________
are prepared from sufficient bulk quantities by mixing the 1-[[methyl[(S)-2-oxo-4-phenyl-3-[(1-piperidinylcarbonyl)amino]butyl]amino]carbonyl]-L-proline and cornstarch with an aqueous solution of the gelatin. The mixture is dried and ground to a fine powder. The Avicel and then the magnesium stearate are admixed with granulation. This mixture is then compressed in a tablet press to form 1000 tablets each containing 100 mg. of active ingredient.
In a similar manner, tablets containing 100 mg. of the product of any of Examples 2 to 30 can be prepared.
A similar procedure can be employed to form tablets containing 50 mg. of active ingredient.
EXAMPLE 32
Two piece #1 gelatin capsules are filled with a mixture of the following ingredients:
______________________________________1-[[Methyl[(S)--3-[(4-morpholinyl- 50 mg.carbonyl)amino]-2-oxo-4-phenyl-butyl]amino]carbonyl]-L-prolineMagnesium stearate 7 mg.Lactose 193 mg. 250 mg.______________________________________
In a similar manner capsules containing 50 mg. of the product of any of Examples 1 and 3 to 30 can be prepared.
EXAMPLE 33
An injectable solution is prepared as follows:
______________________________________1-[[[(S)--3-[[(Cyclohexylamino)- 500 g.carbonyl]amino]-2-oxo-4-phenyl-butyl]methylamino]carbonyl]-L-prolineMethyl paraben 5 g.Propyl paraben 1 g.Sodium chloride 25 g.Water for injection 5 l.______________________________________
The active substance, preservatives and sodium chloride are dissolved in 3 liters of water for injection and then the volume is brought up to 5 liters. The solution is filtered through a sterile filter and aseptically filled into presterilized vials which are closed with presterilized rubber closures. Each vial contains 5 ml. of solution in a concentration of 100 mg. of active ingredient per ml. of solution for injection.
In a similar manner, an injectable solution containing 100 mg. of active ingredient per ml. of solution can be prepared for the product of any of Examples 1, 2 and 4 to 30.
EXAMPLE 34
1000 tablets containing the following ingredients:
______________________________________1-[[[(S)--3-[[(Dimethylamino)- 100 mg.carbonyl]amino]-2-oxo-4-phenyl-butyl]methylamino]carbonyl]-L-prolineAvicel 100 mg.Hydrochlorothiazide 12.5 mg.Lactose 113 mg.Cornstarch 17.5 mg.Stearic acid 7 mg. 250 mg.______________________________________
are prepared from sufficient bulk quantities by slugging the 1-[[[(S)-3-[[(dimethylamino)carbonyl]amino]-2-oxo-4-phenylbutyl]methylamino]carbonyl]-L-proline, Avicel, and a portion of the stearic acid. The slugs are ground and passed through a #2 screen, then mixed with the hydrochlorothiazide, lactose, cornstarch, and remainder of the stearic acid. The mixture is compressed into 350 mg. capsule shaped tablets in a tablet press. The tablets are scored for dividing in half.
In similar manner, tablets can be prepared containing 100 mg. of the product of any of Examples 1 to 4 and 6 to 30. | Compounds of the formula ##STR1## are disclosed. These compounds are useful as hypotensive agents due to their angiotensin converting enzyme inhibition activity and depending upon the definintion of X may also be useful as analgesics due to their enkephalinase inhibition activity. | 2 |
CROSS-REFERENCE TO RELATED APPLICATION(S)
[0001] This application claims priority to the following US Provisionals: “High Voltage Apparatus for Aerosol Delivery”, 60/652,059; “Apparatus for Aerosol Delivery Using Capillary Pumping from a Reservoir”, 60/652,060; “Apparatus for Aerosol Delivery Using Capillary Pumping”, 60/652,064; “Capillary Tip Geometries”, 60/652,057; and “Capillary Wick Aerosol Candle”, 60/652,067, the contents of each of which are fully incorporated herein.
STATEMENT REGARDING FEDERALLY-SPONSORED RESEARCH OR DEVELOPMENT
[0002] Not applicable.
INCORPORATION-BY-REFERENCE OF MATERIAL SUBMITTED ON A CD
[0003] Not applicable.
BACKGROUND OF THE INVENTION
[0004] 1. Field of the Invention
[0005] This invention relates to a device and method for dispensing aerosol sprays in a manner which promotes rapid and consistent vaporization. In particular, the invention relates to dispensing aromas.
[0006] 2. Background
[0007] There are various known techniques for dispensing or dispersing aromas or olfactory stimulants. For example, aromatic oils are often dispersed by application of heat to an evaporation surface. The heat may, however, detrimentally affect the aroma being dispensed. As well, where the aroma dispensing device comprises an aromatic candle, the vapors carrying the aroma are often denatured or oxidized in the candle flame, reducing the intrinsic or “natural” quality of the fragrance. Other aroma dispensing devices rely on the use of propellants or aerosols to enable the dispersion. However, such propellants and aerosols may also detrimentally affect the aroma being dispersed.
[0008] In the conventional aroma delivery devices described above, it is difficult to consistently and precisely control delivery of the sprayed material. For example, in the case of an aromatic candle or other aroma delivery device that operates by using heat causing evaporation, some degree of evaporation will continue after the candle has been blown out or the device has been switched off. In addition, such devices generate an aroma a single aroma, continuously as long as the device is activated. This causes saturation of the olfactory senses and the perceived fragrance declines. Also, aerosol cans and pump sprays may produce large droplets which do not vaporize well and tend to rapidly fall under gravity and settle, also resulting in a continuous or lingering aroma which may degrade with time. Other devices, such as solid evaporative devices, experience a decay in aroma delivery rate over time.
[0009] U.S. Pat. No. 5,196,171 to Peltier describes the generation of vapors and/or aerosols by applying a DC voltage to a wick-like, porous emitter. In this case, the wick comprises a porous “capillament assembly” in which is disposed a central conductive electrode. In operation, the liquid provides a means of conducting the charge from the center of the wick to the outer surface where vaporization takes place due to corona discharge. The greatest concentration of vapors is created at the corners and edges (points or sharp radius edges) where the corona discharge forms.
[0010] Aerosols may also be created by the application of electrohydrodynamic (“EHD”) forces to a liquid. In doing so, the liquid forms a so-called Taylor cone at the EHD comminution site, becomes charged, and forms a jet or ligament which separates, or comminutes, into an aerosol. In utilizing EHD, it is desirable to keep voltages low to avoid corona discharge which is detrimental to the formation of aerosols. U.S. Pat. No. 5,337,963 to Noakes describes a spraying device which comprises a vertically-disposed capillary tube with one end immersed in a fragrance-producing oil. When an electrical potential is applied to the bulk liquid, generally near the submerged end of the capillary, the liquid is sprayed from the top end as a plurality of ligaments which break up into droplets. The applied electrical potential is reported to be in the range of 10-25 kV and must be high enough to cause EHD comminution at the top of the capillary. Liquid is fed by capillary action from a reservoir to the top end of the capillary for aerosolization. U.S. Pat. No. 5,503,335 to Noakes describes a similar spraying device, but which comprises a wick in place of the aforementioned capillary tube. The wick is fabricated from material having an open-celled structure. In this case as well, the high voltage is applied to the bulk liquid, generally near the submerged end of the wick. U.S. Pat. No. 5,810,265 to Cornelius et al. describes yet another similar spraying device, but which capillary structure comprises a hollow capillary tube having a convoluted inner surface to enhance capillary action. Similarly, the high voltage is applied to the bulk liquid, also generally near the submerged end of the capillary tube. Finally, U.S. Pat. No. 5,655,517 to Coffee describes a device for dispensing a comminuted liquid comprising a comminution site provided by fibers formed into a bundle projecting from an end surface or edge.
[0011] In the delivery devices described above, it is difficult to consistently and precisely control delivery of the spray. While EHD spraying offers many advantages, including the ability to produce consistent sprays of aerosol particles having a narrowly-tailored size distribution, significant inconsistencies were observed in the delivery rate of the liquid to the surrounding air.
[0012] It is, therefore, an object of the present invention to provide an aerosol delivery device that avoids or at least reduces adverse effects on an aroma resulting from the manner in which the aroma is delivered. It is another object of the present invention to provide an aerosol delivery device that enables improved control of delivery rate of the aerosol. It is yet another object of the invention to provide an aerosol delivery device that offers consistent aerosol delivery over the reservoir volume. It is a further object of the present invention to provide a method that offers the advantages of reduced adverse effects on the aroma, consistent aerosol delivery of the aroma, and improved capability for rapid vaporization.
[0013] It is a further object of the present invention to provide a device and method for delivering other formulations that benefit from dispersion as an aerosol. These include, for example, anti-microbial agents; insect repellants; attractants; sterilizers; confusants; pheromones; fumigants; odor neutralizers; therapeutic agents, such as menthol and eucalyptus; animal mood control agents; household cleaning products, such as surface cleaning agents, surface modification agents for aesthetic benefits, surface protection agents, and sanitization/disinfectant agents; household laundry care products, such as stain-removing agents, fabric fresheners, and other fabric treatment agents for aesthetic benefits; personal cosmetic care products for body cleaning, body lotion, and sunscreen products for humans; and consumer adhesives. Formulations, especially for aromas, are oil-based, but other carriers may be used such as water, polymers, or organic solvents.
BRIEF SUMMARY OF THE INVENTION
[0014] In one aspect, the present invention provides a method of using EHD to create a spray having a generally-consistent flowrate, preferably an aerosol spray that rapidly vaporizes; wherein capillary action wicks a liquid from a liquid source to an EHD comminution site; a first electrical potential, preferably a high-voltage potential, is applied to a location away from the liquid source and near the EHD comminution site, preferably in or near a tapered portion of a capillary element; a second electrical potential, preferably a ground, is applied to a location external to the EHD comminution site, preferably to enhance the spray without directing the spray.
[0015] In another aspect, the present invention provides a method of using EHD to create a spray, preferably an aerosol spray, wherein the spray is controllably emitted intermittently at a generally-consistent flowrate.
[0016] In another aspect, the present invention provides a method of using EHD to maintain a desired/perceived level of fragrance over an extended period of time (e.g., weeks or months).
[0017] In another aspect, the present invention provides a method of using EHD to create a spray, preferably an aerosol spray, by providing a length of capillary wick having a first and second segments contiguous at a first location, the second segment including at least one EHD comminution site; contacting the capillary wick first segment with a liquid source at a second location spaced from the first location; applying a first electrical potential to the capillary wick at the first location; positioning a reference electrode, preferably a ground, external to the capillary wick; and electrohydrodynamically producing a spray, preferably an aerosol spray, from the at least one EHD comminution site at a generally-consistent flowrate.
[0018] In yet another aspect, the present invention provides an EHD apparatus for creating a generally-consistent flowrate spray, preferably an aerosol spray, comprising a reservoir for containing a source of EHD-comminutable liquid; a capillary element, preferably a capillary wick, comprising an EHD comminution site, positioned to contact the liquid source; a first charge source, preferably a high-voltage electrode, positioned in a spaced-apart relation to the liquid source and operably proximate the EHD comminution site; and a second charge source, preferably a ground, positioned external to the EHD comminution site.
[0019] In yet another aspect, the present invention provides an EHD apparatus for creating a generally-consistent flowrate spray, preferably an aerosol spray, comprising a first charge source, preferably a high-voltage electrode, positioned in contact with the capillary element.
[0020] In yet another aspect, the present invention provides an EHD apparatus for creating two or more generally-consistent flowrate sprays, preferably aerosol sprays, comprising two or more optionally curvilinear capillary wicks in liquid contact with two or more sources of EHD-comminutable liquid.
[0021] In yet another aspect, the present invention provides an EHD apparatus for creating a generally-consistent flowrate spray, preferably an aerosol spray, comprising a housing formed to include an aperture, the aperture formed to include a charge source; a source of EHD-comminutable liquid; a capillary wick, comprising an EHD comminution site, the capillary wick at least partially within the aperture, the EHD site external to the housing, and the capillary wick in liquid communication with the liquid source; and a ground operably proximate the EHD comminution site.
BRIEF DESCRIPTION OF THE SEVERAL VIEWS OF THE DRAWINGS
[0022] The following detailed description of the embodiments of the invention will be more readily understood when taken in conjunction with the following drawings, wherein:
[0023] FIG. 1 is a schematic cutaway of an embodiment of the present invention and illustrating its components.
[0024] FIG. 2 is a partial detailed schematic cutaway of the embodiment of the present invention shown in FIG. 1 .
[0025] FIGS. 3 a - 3 h are schematic cutaways of various capillary means with associated electrodes according to further embodiments of the present invention.
[0026] FIG. 4 is a schematic cutaway of an embodiment of the present invention illustrating optional curvilinear capillary elements and an optional offset reservoir.
[0027] FIG. 5 is a schematic cutaway of an embodiment of the present invention illustrating a spray device comprising a taper-like candle configuration and showing a narrow and deep liquid reservoir.
DETAILED DESCRIPTION OF THE INVENTION
[0028] EHD comminution entails the use of high voltages to charge liquids so that the electric charge on the liquid overcomes the surface tension of the liquid and the liquid is broken up, or comminuted, into a spray of fine aerosol droplets. In doing so, droplet size and droplet size distribution may be closely controlled. Droplet size may be in the sub-micron range, thus enabling rapid vaporization of the aromatics without denaturing and effecting a rapid onset of a perceived fragrance. Turning to FIGS. 1 and 2 , to induce this action, the liquid must experience a high electric field, but preferably only at the point of comminution, known as the spray site, or EHD comminution site 35 . To accomplish this, the bulk liquid 29 in the reservoir 32 may be charged and the charge is conducted through the liquid to the EHD comminution site 35 at the tip of the delivery column 34 . To create the required electric field, an opposing electrode, often referred to as a reference or inducing electrode, and often a ground 26 , is spaced away from the spray site 35 to help generate a well-defined field. In applications where the liquid exhibits relatively high resistivity, such as with many aroma oils, or is semi-conductive, it is possible to induce a potential differential across the liquid itself if sufficiently high voltage is applied between the reservoir 32 and the reference electrode 26 and electric current flows through the highly-resistive liquid. As this happens, however, undesirably high levels of electric field pumping may occur.
[0029] There are, in fact, two liquid movement mechanisms at play. The first is the capillary action associated with the liquid interaction (liquid surface tension, dynes/cm) with the surface energy of the capillary means (dynes/cm). The second is the electric field pumping due to the high voltage imposed on the liquid to induce aerosolization. It has been found that when a high-voltage charge sufficient to induce EHD spraying is applied to the bulk liquid, even near the capillary inlet for aroma and aerosol generation, a high degree of liquid delivery variability results at the EHD spray site at the opposite end of the capillary. It is believed that high-voltage pumping may contribute to the mechanism of liquid movement in the capillary at voltages necessary for EHD spraying, and that the voltage gradient along the capillary results in inconsistent movement through the capillary voids, particularly when fluid levels' in a supply reservoir change over time.
[0030] Turning again to FIGS. 1 and 2 , an embodiment of the present invention is shown. The dispensing device 10 generally comprises a housing 12 ; a liquid source 29 , preferably contained within a reservoir 32 ; a voltage source, generally an electrode 31 ; a capillary element 34 terminating in an EHD comminution site 35 , generally, a capillary element with an associated electrode 31 ; and a reference electrode, or ground 26 , 27 . Additionally, the dispensing device 10 may comprise a removable cap 14 that allows access to the internal components of the device 10 , a base 16 to further contain the internal components and to provide a stable platform for the device 10 when placed upon a horizontal surface, a battery 18 , a high-voltage power supply 22 to convert voltage (e.g., 9V) from the battery 18 to the higher, kV-level voltage required for operation of the device 10 , a circuit board 20 to handle the electronics functions such as timing, voltage control, operational indicators (e.g., lights, and control of intensity and delivery rate), a high-voltage lead 30 running between the output of the high-voltage power supply 22 and the electrode 31 , and a switch 24 to control operation of the device 10 . The optional light (not shown) may optionally contribute to a burning candle-like appearance for the device 10 or may be used to illuminate the spray, evoking a fountain-like effect. Optionally, the device may also comprise various control features to allow a user to adjust the spray and timing of the device.
[0031] In operation, liquid is supplied to the delivery column 34 , 64 (e.g., FIG. 3 c ) from the liquid source 29 . The delivery column 34 , 64 generally comprises a capillary element 46 , 66 ( FIG. 3 ) which may be formed from a capillary tube 46 ( FIG. 3 a ) or a wick 66 ( FIG. 3 c ) which will enable the liquid to be drawn toward the EHD comminution site tip 35 where a voltage charge causes the liquid to EHD comminute into an aerosol. As described above, placement of the electrode 31 , 68 is important to providing consistent liquid and aerosol delivery rates. Capillary action has been shown to be an effective method for moving liquid from the reservoir 32 to the EHD comminution site 35 . However, there may be inconsistencies in delivery rate of the liquid to the site 35 and of the aerosol to the surrounding air, possibly caused by electric field pumping, the result of the high voltage imposed on the liquid to induce aerosolization causing electric current flow through the liquid. This high voltage over the entire length of the delivery column 34 , 64 , however, is believed to cause electric field pumping to contribute to and result in inconsistent liquid flow rates. By minimizing this electric potential differential over the liquid path, consistent liquid delivery rates may be achieved. Advantageously, by using the capillary element 46 , 66 to move liquid from the liquid source 29 to the EHD comminution site 35 , active pumping of any kind, including positive-displacement, is avoided. Importantly, too, the flowrate of the spray can remain generally-consistent over the delivery of the liquid in the reservoir 32 .
[0032] Many capillary elements are possible. The important attribute is the ability to deliver the liquid from the liquid source 29 to the EHD comminution site 35 . The rate of capillary delivery must be sufficient to at least match the rate of EHD comminution or the EHD comminution site 35 will be starved of liquid and aerosolization will cease, or at a minimum aerosolization oscillates as liquid partially replenishes the EHD comminution site 35 and is sprayed away. Capillary tubes 46 ( FIG. 3 a ), capillary tubes 46 filled with a porous material 56 ( FIG. 3 b ), and fiber-like wicks 66 ( FIGS. 3 c - 3 h ) have been used successfully. A sample of common off-the-shelf paper towel material formed into a capillary element has been used successfully.
[0033] Tubing materials include ABS, rigid PVC, polyester, polyamide, glass, Teflon® (poly-tetrafluoroethylene), PEEK, and polyimide. To maximize the capillary action using polymer tubes, an acceptable adhesion to the tube occurs when the surface energy of the polymer is greater than the surface tension of the liquid, preferably about 8-10 dynes/cm or more greater than the surface tension of the liquid. In spraying aromatic oils with surface tensions in the range of 27-30 dynes/cm, for example, preferred materials would include (with representative surface energy values) ABS (35-42 dynes/cm), rigid PVC (39 dynes/cm), polyester (41-44 dynes/cm), polyamide (ca. 36 dynes/cm), and polycarbonate (46 dynes/cm). While preferred, the capillary tube 46 need not be a single element. Multiple tubes and multiple tubes clustered together may be used. The capillary tube 46 need not be limited to a cylinder with a single opening. For example, two or more tubes may be coaxially combined to create a central aperture along with one or more annular apertures.
[0034] In accordance with the present invention, open-cell, porous, or fiber-like wicks are most preferred for spraying aromatic aerosols. By way of example only, and not limitation, wicks include plotter pen wicks, felt nibs, china bristles, twisted nylon twine, braided shoelaces, foam materials, and candle wicks. Materials may be polymeric, such as polyester, or natural, such as cotton. Exemplary, the porous wicking material has an open cell structure with a porosity of about 40 percent. Preferably, the voids have consistent size and shape and the wicks exhibit uniformity from one wick to another. Preferably, each wick has a well-defined tapered, conical tip that is consistent from wick to wick. Preferably, each conical tip has a low height-to-diameter aspect ratio, but high enough to provide an effective EHD comminution site 35 .
[0035] Further, the present invention enables flexibility in design. Multiple capillary elements or wicks ( FIG. 4 ) may be configured with multiple reservoirs (not shown) within the same dispensing device. As shown in FIG. 4 , the capillary elements 166 may have curvilinear shapes to allow for placement of the spray sites, and positioning of the reservoir(s) 132 and other internal operational elements as required for a particular application. The size and shape of the other elements or desired placement of replaceable reservoirs may dictate non-symmetrical apparatus designs, irregularly-shaped reservoirs 132 , and curvilinear capillary elements 166 . There may be multiple spray sites drawing from a single reservoir. Where there are multiple reservoirs (not shown), multiple liquids may be sprayed either simultaneously or in a timed sequence. This latter capability enables the ability to dispense a first aroma and then cycle through separate aromas, thereby providing a continuous level of perceived fragrances and avoiding the phenomenon of olfactory saturation.
[0036] A key element in the present invention is the placement of the electrode 48 , 68 relative to the capillary element 46 , 66 , specifically relative to the EHD comminution site 35 . As discussed above, if the electrode 48 , 68 is placed in the bulk liquid in the reservoir 32 , even if placed near the bulk liquid end of the capillary element 46 , 66 in the liquid, high voltages are required to effect aerosolization at the EHD comminution site 35 , especially with liquids having high resistivities, with resultant high levels of electric field pumping which produce inconsistent delivery rates.
[0037] Viewing the capillary element 46 , 66 as a column of liquid, it acts as a resistive element to the electric potential between the electrode 68 ′ ( FIG. 3 c ) and the EHD comminution site 35 at the end of the capillary element 46 , 66 . A longer path effects a higher resistance and voltage drop which leads to the need for a higher electric potential and a less-consistent flowrate of aerosol. By reducing the distance between the EHD comminution site 35 and the electrode 68 , the resistance and voltage drop decrease, the required voltage decreases, and a more-consistent flowrate of aerosol results. Thus, the present invention limits electric field pumping to a smaller length of the capillary element 46 , 66 . However, as shown in FIG. 3 , the electrode 48 , 68 , 78 , 88 , 88 ′, 98 , 98 ′, 108 does not extend beyond the EHD comminution site 35 ; some material of the capillary element covers or extends beyond the electrode. This is where the liquid gathers via capillary action to be available to the high-voltage charge to aerosolize it. As a result, the present invention improves delivery rates, allowing for consistent, repeatable delivery rates over time. In the field of aroma delivery, for example, this may be very desirable.
[0038] The main factors in placing the electrode 68 to reduce or eliminate electric field pumping is proximity to the spray tip 35 and sharpness of the tip 35 . Minor factors include liquid resistivity, capillary uptake, aerosolization rate, and position of the ground 26 . In practice, the electrode 68 must be placed operably, or effectively, proximate the EHD comminution site 35 . That is, the position of the electrode 68 relative to the EHD comminution site 35 must be adjusted to produce a consistent aerosol delivery rate given the properties noted above. Not only may consistent delivery rates be achieved during each “on” cycle (discussed below), consistent delivery rates may be achieved over extended periods of “on” and “off” cycles.
[0039] As a measure of consistency over a series of tests, the percent C v was calculated by dividing the standard deviation by the mean. This measurement allows for comparing equally various wicks and configurations. The lower the C v , the more consistent the flowrate. By changing the charge location, for example from 68 ′ to 68 , the percent C v improved (was reduced) in the range of three to 15 percentage points. For example, one wick improved from 28.7 percent C v to 19.3 percent C v . For aromas, the preferred percent C v is less than 20, more preferably less than ten. Much below ten percent is barely discernable by the average human olfactory senses. In general, the position of the charge electrode 68 has been found to be within the conical portion of the spray tip. As an example, for non-conducting wicks tested, the position of the charge source 68 has been in the range of 0.020 inches to 0.250 inches from the comminution site 35 to the charge point 68 . The measurement for a conducting wick would be virtually zero.
[0040] Numerous electrode embodiments are feasible, all producing the same desired result of improved consistency of aerosol delivery rates with reduced electric field pumping. Importantly, as discussed above, the electrode 68 is placed away from the bulk liquid and the liquid uptake and nearer the EHD comminution site 35 to reduce the large voltage differential between the electrode 68 and the EHD comminution site 35 . Illustrated in FIG. 3 are various possible electrode configurations relative to the capillary element 64 and the EHD comminution site 35 . FIG. 3 a shows a basic capillary element 44 comprising a capillary tube 46 with a voltage source electrode 48 positioned within the tube 46 . As liquid is drawn into the tube 46 , the electrode 48 provides a charge at the EHD comminution site 35 sufficient to aerosolize the liquid. The effects of electric field pumping are limited to that portion of the tube 46 between the voltage source electrode 48 and the EHD comminution site 35 . FIG. 3 b shows a similar arrangement, but with a porous material 56 disposed within the capillary tube 46 . Operation of the capillary element 54 shown in FIG. 3 b is similar to that of the capillary element 44 shown in FIG. 3 a . As shown in FIG. 3 c , a capillary element 64 may comprise a porous wick 66 into which is inserted a voltage source electrode 68 . The embodiment shown in FIG. 3 c provides a voltage source 68 inserted into the wick 66 near the EHD comminution site 35 . As in the previous embodiments, the electric field pumping is controlled and consistent aerosol delivery results. With just the voltage source electrode 68 operative, it is possible, in some embodiments, to have small amounts of undesirable electric field pumping downward and counter to the upward capillary action flow. This may be countered by positioning an additional voltage source electrode 68 ′ as shown. Thus, the electrical potential across the wick 66 may be equalized, or nearly so, and there is little or no counter electric field pumping. Turning now to FIG. 3 d , yet another embodiment of a capillary element 74 is shown. Here, a voltage source electrode 78 comprises a helical coil positioned coaxial with the porous wick 66 . As long as the voltage source electrode 78 is positioned operably proximate the porous' wick 66 , whereby a sufficient charge is imposed on the liquid, electric field pumping is controlled, and consistent aerosol delivery results. Counter electric field pumping is also minimized or eliminated. FIGS. 3 e - 3 h illustrate yet other embodiments of the capillary element 84 , 94 , 104 , 114 of the present invention. The voltage source electrode 88 , 98 , 108 , 118 may comprise a sheath surrounding the porous wick 66 as shown or, alternatively, the voltage source electrode may comprise arcuate tabs or the like (not shown) which may be positioned operably proximate the porous wick. Finally, FIGS. 3 g and 3 h illustrate an embodiment wherein a portion of the housing 12 or reservoir cover 33 is formed to include the voltage source electrode 108 , 118 . Plastic materials of construction (with their respective nominal ohm/square resistivities) for such voltage source electrodes 108 , 118 include anti-static (E9-E12), static dissipative (E6-E9), and conductive plastics (E3-E6).
[0041] To improve aerosol delivery, maximize aroma dispersion, and improve plume intensity and shape, it is preferred to place a ground or other reference electrode 26 operably proximate the EHD comminution site 35 . FIGS. 1 and 2 show an example of the placement of the ground 26 . If the ground 26 is placed too far from the EHD comminution site 35 , the charge at the site 35 does not “see” the ground 25 and its effects are not noticeable. If the ground 26 is placed too close to the EHD comminution site 35 , the aerosol spray may be misdirected toward the ground 26 . Preferably, the ground 26 is placed to generate an electric field required to produce an aerosol without causing the spray to be attracted to the ground 26 . The optimal position of the ground 26 will depend upon the particular configuration of the device 10 . The liquid properties, particle size, spray site geometry, and corresponding electric field potential needed may affect the placement of the ground 26 . Referring to FIG. 1 , the ground 26 is positioned off to the side and near the top of the delivery module 28 or just below the capillary element 34 . The ground 26 may be a neutral or opposite charge to the aerosol particles spraying from the EHD comminution site. Alternatively, depending upon the application, the electrode 26 may be disposed closer to the site 35 to purposely direct the aerosol spray. If desired, the ground 26 may comprise an adjustment (not shown) to allow varying of the position of the ground 26 . The materials used for the ground 26 may be any conductor, including, but not limited to, metals and plastics. The aerosol produced is preferably charged, but may be discharged and dispersed as neutral particles for selected applications. Alternatively, an external ground reference electrode 26 may be utilized. For example, an object or an animal, human or otherwise, may provide the ground reference.
[0042] Preferably, various timing and control mechanisms are included as elements on the circuit board 20 or elsewhere. When the device 10 is initially activated in a room to emit an aroma(s), for example, it may be desirable to introduce a quantity of aroma sufficient to provide scent to the entire room after which the device 10 would shut off. Later, it may be desirable to periodically introduce a “maintenance” amount of scent to keep the level in the room constant and to counter the tendency of aromas to deaden or desensitize the sense of smell over time. This could be done by timing short sprays of perhaps several seconds duration with longer periods of quiescence. Such timing could also be used with multiple sprays having the same or different formulations. Depending upon the strength of the aroma, longer “on” times, upwards of one minute or more, may produce “hot spots” where the fragrance may become overwhelming. In these situations, the “off” time may be a minute or more.
[0043] Having multiple fragrances in a single dispenser 10 enables several other types of operation. For example, fragrances that are related to each other may collectively produce a “bouquet” effect. By controlling dispensing to specific times of the day, one fragrance may induce an invigorating effect (morning), a calming, or stress-relieving effect (midday), and yet another, a relaxing effect (evening).
[0044] Using a timing mechanism the device 10 may maintain a constant delivery rate even if fluid flow rate declines over time. For example, the delivery rate may be maintained through shorter spray intervals within a spray cycle time. Thus, if less liquid flows through the capillary wick 66 over time, a spray “on” interval may increase from, for example, five seconds to greater than five seconds. Alternatively, or in combination, the “off” time interval may decrease from, for example, 45 seconds to less than 45 seconds. These timing schemes can create an effective or perceived level of constant aroma delivery to the air.
[0045] Many aromatic formulations have resistivities of greater than 5 E3 ohm-cm and surface tensions of between ten to about 50 dynes/cm. To produce an aerosol from these formulations, typical voltage levels are 3-10 kV and higher. For cost and battery-life considerations, it is preferred to maintain the required voltage to a minimum. Flowrates may be 0.005-0.100 μL/sec and delivery rates 5-50 mg/hr.
[0046] While the invention has been described in connection with specific embodiments for the purposes of illustration and description, it is not intended to be exhaustive or to limit the invention to the precise form disclosed. Numerous modifications and variations are possible in light of the above teaching. It is intended that the scope of the invention be limited not by this detailed description, but rather by the claims appended hereto. | A method for delivering an aerosol, especially an aromatic aerosol, comprising the steps of contacting a capillary wick, comprising an EHD comminution site, with a liquid source, whereby at least a portion of the liquid transports to the EHD comminution site; applying a voltage to the liquid within the capillary wick at a location spaced apart from the liquid source and proximate the EHD comminution site; and applying a ground reference at a location external to the EHD comminution site, wherein at least a portion of the liquid EHD comminutes to form a spray having a generally-consistent flowrate and a device therefor. | 1 |
REFERENCE TO RELATED APPLICATIONS
[0001] This application is a continuation of U.S. patent application Ser. No. 14/662,314, filed Mar. 19, 2015 and entitled “Cylindrical Collapsible Container”, now pending, which is a continuation of U.S. patent application Ser. No. 14/538,059, filed Nov. 11, 2014 and entitled “Cylindrical Collapsible Container”, now abandoned, which is a continuation of U.S. patent application Ser. No. 14/537,195, filed Nov. 10, 2014 and entitled “Cylindrical Collapsible Container”, now abandoned, which is a continuation of U.S. patent application Ser. No. 14/293,336, filed Jun. 2, 2014 and entitled “Cylindrical Collapsible Container”, now abandoned, which claims priority to EP13170288.8, filed Jun. 3, 2013 and entitled “Cylindrical Collapsible Container,” all of which are hereby incorporated by reference in their entirety.
TECHNICAL FIELD
[0002] The present invention relates to a container for holding a liquid. In particular the invention is related to such a container for medical use, such as a container for use in irrigation, e.g. rectal or urinary irrigation, or supply of liquid in other types of medical applications, for treatment of a human or animal patient. The container is particularly useable for rectal irrigation, and is suitable for self-administration of an irrigation liquid.
BACKGROUND OF THE INVENTION
[0003] Containers for storing, collecting or transporting liquids are widely used in e.g. the food industry or in the medical field. In the medical field, containers are frequently used for e.g. collecting or storing of body liquids or liquid medications but also for delivery of a liquid to a patient. Such a delivered liquid may be for e.g. intravenous, flushing, or rectal enema. A liquid to be delivered to a patient may also be known as an irrigation liquid.
[0004] Administrating an irrigation liquid is a common medical procedure whereby liquid is injected into a bodily cavity, such as into the rectum and lower intestine of a patient in order to induce bowel movement. The need for such a procedure typically arises in patients suffering from certain physical ailments in which voluntary bowel control is impaired or when the bowel needs to be cleaned before e.g. a coloscopy or a surgical operation. To this end, irrigation systems may be used e.g. by people suffering from spinal cord injuries, spina bifida or multiple sclerosis. For such users, irrigation may improve quality of life by preventing constipation, reducing time spent for bowel emptying procedures, reducing fecal incontinence, and by increasing independency in general.
[0005] Irrigation is nowadays often performed outside medical attendance premises, such as in the patient's home, and is also often performed by the patient himself, i.e. by self-administration. Hereby, the patient need to do multiple tasks at the same time, or immediately following on each other, such as inserting the probe in a correct position, adequately fixating the probe in the bodily cavity, enabling the liquid to be discharged for irrigation and discharge a correct dose of irrigation liquid, and removing the probe after use. Further, many of the users of irrigation systems have reduced dexterity, which makes the operation even more cumbersome.
[0006] It is further of importance that the irrigation system is of a limited size, and portable. Portability of the irrigation system is important to disabled persons who are not hospitalised or bed-ridden if they are to live as normal a life as possible. This is particularly important if they travel away from their home, for instance, to someone else's home or if they stay in a hotel. In this situation, they need to be able to deal with their bowel function easily.
[0007] Various irrigation systems are known in the art, such as is disclosed in WO 2008/087220, WO 2009/092380, WO 03/030969, WO 2011/023196 and WO 03/030968. However, despite the attempts to make these devices user friendly, all of these irrigation devices are still relatively large and complicated to use, especially for self-administration of the irrigation liquid, and also, most of these known devices are made of many different components and are relatively costly to produce.
[0008] For delivery of irrigation liquid stored in a container a certain pressure is often required in the container to enable a flow of liquid from the container. In some cases the container, for example for intravenous insertion, is hanged above the patient. In other cases the container is pressurized by external means such as physical deformation of the container or by pumping of air into the container.
[0009] In many cases it is desirable that the container may be collapsible in order to save space before and after usage. In particular, this is desirable when storing the container prior to use or when transporting containers to a user.
[0010] In US 2010/0174252 a container for rectal irrigation is disclosed. The disclosed container relies on air to be pumped into the reservoir in order to provide sufficient pressure for delivery of liquid.
[0011] U.S. Pat. No. 3,641,999 discloses another container for use as an irrigation liquid reservoir. It is arranged such that it may stand up on a rigid bottom portion and it has an outlet tube at the bottom portion. The container as disclosed in U.S. Pat. No. 3,641,999 is collapsible.
[0012] Another container to be used for irrigation is disclosed in U.S. Pat. No. 7,942,578. It is a collapsible container comprising seams for holding the container together. A hole is arranged for adding or withdrawing liquid form the container.
[0013] The known collapsible containers suffer from a number of drawbacks. For example, it would be desirable to allow a space efficient storage of the container without compromising the stability of the container, while allowing the container to be in a standing-up configuration when in use. Furthermore, it is desirable to allow an efficient withdrawal of the entire volume of liquid contained in the container, without leaving unnecessary residues when in use. It is also desirable to reduce the risk of continuing pumping when the container is empty, or almost empty. It is further desirable to facilitate handling of the container, such as filling of liquid into the container, for users having reduced dexterity. It is also desirable to have a container which is reusable, and which may easily be emptied, dried and compacted between uses. Still further, there is a need for containers of this type which can be made relatively cost-efficiently.
[0014] Thus, there is a need for an improved collapsible container, in particular for medical use, such as for holding and delivering of irrigation liquid.
SUMMARY OF THE INVENTION
[0015] In view of the above mentioned need, a general object of the present invention is to provide an improved container for holding e.g. irrigation liquid which at least to some extent alleviates the above-discussed problems of the prior art, and at least partly fulfils the above-discussed needs.
[0016] This object is achieved by means of a collapsible container and a method for reversably compacting a container in accordance with the appended claims.
[0017] According to a first aspect of the present invention, there is provided an apparatus comprising a container for medical use forming a closed compartment for carrying a liquid, comprising: a side wall member formed by a sheet material and forming a side wall of the closed compartment, the side wall member comprising oppositely arranged first and second open ends; a rigid bottom portion arranged at the first open end of the side wall member such that the bottom portion seals the first open end of the side wall member, thereby forming a bottom of the closed compartment; a rigid top portion arranged at the second open end of the side wall member such that the top portion seals the second open end of the side wall member, the top portion forming the top of the container, and having at least a first through going hole; and a flexible tube arranged inside the compartment, the tube having a first end portion and a second end portion; wherein, the first end portion of the tube is connected to the bottom portion, the first end portion being provided with an opening towards the compartment, and the second end portion is connected to the top portion and in fluid communication with the first hole of the rigid top portion; wherein the side wall member is flexible such that the container is reversibly foldable and unfoldable, thereby being arrangeable in a compact state, in which the rigid top and bottom portions are arranged relatively closer to each other, and in an expanded state, in which the rigid top and bottom portions are arranged relatively further apart, respectively.
[0018] The seal between the side wall member and the top and bottom portions, respectively, are preferably arranged as a fixed connection, e.g. obtainable by means of welding, adhesion or the like. However, reversible connections are also feasible.
[0019] The term “rigid” here indicates that the top and bottom portions are more rigid, and preferably substantially more rigid, than the side wall member. Preferably, the top and bottom portions maintain their shape during normal use.
[0020] The present invention is based on the realization that by arranging a collapsible wall between relatively rigid bottom and top portions, a very stable container is obtained, which may still be highly compressible. Further, the arrangement of an internal tube, connecting an outlet/inlet at the bottom to the top, the container becomes easy and reliable to drain/fill. This compressible container has several further advantages over prior art containers. A compressible container is easy to fill because the size of the container is relatively compact, with an efficient space utilization, and also, the shape may easily be adapted to e.g. different sized sinks. The container is also easy to fill in situations where a tap or filling station is at a different angle. In such case, the container may be appropriately flexed at the compressible side walls.
[0021] The container is further advantageous because the container may be very compact in the compacted disposition. This way, storing and transporting of the container, or a plurality of containers may be more efficient. In particular, the container may, in the compacted state, be relatively flat and disk shaped, which makes the container easy to carry around, e.g. in a pocket or a bag.
[0022] The rigid top and bottom portions makes the container have a high stability while having the flexible side walls. This is advantageous because it may allow e.g. a stable up-right position of the container when in use.
[0023] A flexible tube is advantageously connected at the bottom portion. This way, the container may more efficiently be emptied during use. Furthermore, it may prevent pumping air or the like out from the container since the opening of the tube inside the container is ensured to stay close to the bottom, and below a level of liquid in the container.
[0024] The container may be produced in a cost-efficient way. The container is further reusable and easy to clean, dry and compact after use.
[0025] According to an embodiment of the present invention, a second through going hole is arranged such that, when in use, liquid may pass through the tube and the first hole through a sealed connection between the tube and the top portion, and such that if pressurized gas is supplied through the second hole, when in use, liquid from inside the enclosure will be provided through the tube and through the first hole. This is advantageous because it allows a user-friendly way to withdraw liquid from inside the container. The second hole may be arranged such that it allows pressurized air to enter at the top portion such that it may pressurize the inside of the container. This way, liquid may be forced out from the container through the tube and the first hole.
[0026] The flexible tube is advantageously twisted, to curl up when the container is brought to the compact state. This is advantageous because it facilitates compacting of the container. This way, the flexible tube may be curled up into a compact state when the container is compressed into a compacted state. By the term “twisted” is here preferably meant that the first end portion and the second end portion of the tube are relatively rotated with respect to each other in comparison with a normal, unbiased state.
[0027] Further, the container may comprise at least one locking element to maintain the container in the compact state. This is advantageous because it may prevent the container from unfolding into a state different from a compacted state. This way, the container may be stored in a compacted state with reduced risk of unfolding to an expanded state. A locking member may be a pivotally arranged snap in connection. Such locking elements may also be realized as a stretchable or un-stretchable band movable around the container, by hooks, or the like.
[0028] The present invention may further comprises a handle in the top portion. A handle may be pivotally arranged such that it may be folded towards the top portion. This way, the overall size of the container may be reduced. A handle is advantageous because it may enable easier transportation of the container by a user. A handle may allow a user to move the container in a more user-friendly way. A handle may allow a user to hang the container from an appropriate element.
[0029] Similarly, the present invention further comprises a handle in the bottom portion. A handle may be pivotally arranged such that it may be folded towards the bottom portion. This way, the overall size of the container may be reduced. A handle is advantageous because it may enable easier transportation of the container by a user. A handle may allow a user to move the container in a more user-friendly way. A handle may allow a user to hang the container from an appropriate element. This is e.g. useable for drying the container after use.
[0030] According to an embodiment of the present invention, in the compact state, the top and bottoms portions are in contact with each other. This way, the size of the container is efficiently reduced for e.g. storage, filling, or transportation. Contact may be made at one or several contact points. At contact the top and bottom portions may be essentially parallel to each other. Hereby, the height of the container in the compact state will essentially correspond to the height of the top and bottom portions.
[0031] The top and bottom portions are preferably essentially equal in diameter and circumferential shape. This allows the side wall member to be shaped as a tube with even diameter. However, the top and bottom portions may also have different dimensions and/or shapes. Hereby, one of the top and bottom portions may e.g. be allowed to be at least partly accommodated by the other in the collapsed state.
[0032] Furthermore, in the compact state, the top and bottoms portions may be rotated relative each other compared to when in the expanded state. This is advantageous because it may allow the size of the container to be further reduced when in the compacted state. This, way the flexible side walls may collapse in a direction essentially perpendicular to a longitudinal direction of the container. In other words, in a direction essentially perpendicular to the direction the container may be compacted. This way, the side walls may collapse in both the longitudinal direction and in a transverse direction. However, collapsing solely in the longitudinal direction is also possible.
[0033] In the compact state, the container may be less than the height of the expanded state, and preferably less than ⅓, and more preferably less than ¼, and even more preferred less than ⅕. This is advantageous because it may allow more size efficient storage or transportation of the container. It may further allow filling of the container from taps or filling stations with reduced or cramped space. Preferably, the height of the container in the collapsed state is less than 5 cm, and most preferably less than 3 cm for a container capable of holding at least 1 liter in the expanded state.
[0034] Preferably, the side wall member is cylindrical in the expanded state. This way, the container may be easy to produce. Furthermore, it may facilitate compacting of the container.
[0035] The flexible side wall may be formed in various ways. It may e.g. be produced as a tubular member by means of extrusion or injection molding. It may also be formed by one or several sheet materials, e.g. connected together by means of welding or adhesion. However, other production methods may also be used, such as vacuum forming and the like.
[0036] According to an embodiment of the present invention, the container is advantageously adapted for use in an irrigation system, and preferably a system for rectal irrigation.
[0037] The tube is advantageously made from silicone. This is advantageous because it may facilitate production of the container. It may also make production cost efficient. It is further advantageous because silicone is a strong and flexible material. However, other materials may also be used.
[0038] According to an embodiment of the present invention, the top portion comprises a lid pivotally connected to the top portion and arranged to cover and seal a filling hole. This is advantageous because it may prevent unintentional spilling of liquid from inside the container. The lid may advantageously be attached to the top portion with a snap-in connection. When the container is in use, the lid may seal the filling hole of the container. There may advantageously be an o ring arranged between the filling hole and the lid.
[0039] The lid arranged on the top portion may further comprise a pressure valve arranged and configured to hold a pressure of at least 150 mbar inside the container, but release pressure when a certain threshold level has been obtained. This is advantageous because it may protect the container from overpressure. For example, the flexible tube may be clogged or otherwise prevented from allowing liquid to be withdrawn from the container when pressurized air is applied to the inside of the container. In such case, the pressure valve may prevent disruption of the container due to overpressure.
[0040] Moreover, the tube is attached to the bottom portion via a snap-in connection. This may advantageously keep the second end of the flexible tube connected at the bottom portion. A snap-in connection may be easy to fabricate and it may allow a user-friendly reversible attachment of the tube to the bottom portion.
[0041] The container may advantageously comprise a temperature sensor for sensing a temperature of the liquid. This is advantageous because it may allow a direct read-out of the temperature of the liquid before use. The temperature of the liquid may be important for some applications, or it may be important for comfort for a user.
[0042] Preferably, the side wall member is made from a plastic material, such as polypropylene, polyimide, polyethylene, EBA, or combinations thereof. This is advantageous because it may facilitate production of the container. It may also make production cost-efficient. It is advantageous because the above-mentioned materials are flexible materials. However, other materials are also useable.
[0043] According to another aspect of the invention, there is provided an irrigation system, comprising a collapsible container of the above-discussed type. The irrigation system is preferably a portable system, and preferably a system intended for self-administration. In addition to the container, serving as a reservoir for housing the irrigation liquid, the system may in addition comprise all, or at least some of the following additional elements:
a probe for arrangement in a user; A pump for directly or indirectly pumping irrigation liquid from the reservoir/container to the probe; a control unit for controlling the pump, and thereby also the transfer of said irrigation liquid; and tubing providing fluid communication between said reservoir, control unit and probe.
[0048] According to a further aspect of the invention, there is provided a method for reversibly compacting a container, comprising the steps of: moving a rigid bottom portion and a rigid top portion of the container towards each other, thereby collapsing a side wall member formed by a flexible material arranged between the rigid bottom and top portions; and locking the rigid bottom and top portions to each other in the compacted state; wherein the container further comprises a flexible tube arranged inside the compartment, the tube being connected to the bottom portion and the top portion to provide fluid communication between the interior bottom of the container and a discharge hole of the rigid top portion; wherein, the tube and the side wall member are reversibly foldable and unfoldable.
[0049] By means of these further aspects, similar advantages and advantageous embodiments as discussed above in relation to the first aspect are obtainable.
[0050] According to an embodiment, moving the top and bottom portions away from each other comprises rotating the top and bottom portions relative to each other. This is advantageous because it may allow the size of the container to be further reduced when in the compacted state. This, way the flexible side walls may collapse in a direction essentially perpendicular to a longitudinal direction of the container. In other words, in a direction essentially perpendicular to the direction the container may be compacted. It is further advantageous because it may allow collapsing the container in a more controlled way since the side wall is compacted more efficiently.
BRIEF DESCRIPTION OF THE DRAWINGS
[0051] For exemplifying purposes, the invention will be described in closer detail in the following with reference to embodiments thereof illustrated in the attached drawings, wherein:
[0052] FIG. 1 is an exploded view of a container according to an embodiment of the present invention;
[0053] FIG. 2 is a cross-sectional view of the embodiment illustrated in FIG. 1 ;
[0054] FIG. 3A is an illustration of a container according to the embodiment of FIGS. 1 and 2 in a partly collapsed state;
[0055] FIG. 3B is an illustration of a container according to the embodiment of FIGS. 1 and 2 in a collapsed state;
[0056] FIG. 4A is an illustration of the container of FIGS. 1 and 2 in an even more collapsed state, and having a first locking means for retaining the container in this collapsed state;
[0057] FIG. 4B is an illustration of the container of FIGS. 1 and 2 in an even more collapsed state, and having a second locking means for retaining the container in this collapsed state;
[0058] FIG. 4C is an illustration of the container of FIGS. 1 and 2 in an even more collapsed state, and having a third locking means for retaining the container in this collapsed state; and
[0059] FIG. 5 is a schematic illustration of an irrigation system in accordance with an embodiment of the present invention, and comprising a collapsible container as illustrated in the preceding figures.
DETAILED DESCRIPTION OF PREFERRED EMBODIMENTS
[0060] The present invention will now be described more fully hereinafter with reference to the accompanying drawings, in which a currently preferred embodiment of the invention is shown. This invention may, however, be embodied in many different forms and should not be construed as limited to the embodiments set forth herein; rather, these embodiments are provided for thoroughness and completeness, and fully convey the scope of the invention to the skilled addressee. Like reference characters refer to like elements throughout. The illustrated embodiment is shown with reference to be used in an irrigation system, and preferably a system for rectal irrigation.
[0061] The apparatus illustrated in the exploded view FIG. 1 comprises a container 1 which comprises a side wall member 2 , a rigid bottom portion 3 , a rigid top portion 4 , a flexible tube 5 , a handle 6 , a first lid 7 , a pressure valve 8 , and a second lid 9 .
[0062] In the embodiment illustrated in FIG. 1 , when assembled, the bottom portion 3 is arranged at a first open end 10 of the side wall member 2 such that it seals the first open end 10 . The rigid top portion 4 is arranged at a second open end 11 of the side wall member 2 such that it seals the second open end. There are a first 12 , a second 13 and a third 14 through-hole in the rigid top portion 4 . The third through hole being a filling hole 14 , may be used for filling the container 1 with a liquid, has an o-ring 15 arranged around the circumference of the hole 14 . Arranged on the o-ring 15 is a first lid 7 for sealing the filling hole 14 . The o-ring is arranged between the first lid 7 and the rigid top portion 4 . The first lid 7 is pivotally connected to the rigid top portion 4 . In the first lid 7 there is arranged a through-hole 16 . The through-hole 16 is arranged such that a pressure valve 8 may be arranged in the though-hole 16 . The pressure valve 8 may be arranged for maintaining a pressure of e.g. 150 mbar with 1500 ml of liquid at a temperature of 45° C. in the container 1 . A second lid 9 is arranged to cover the pressure valve 8 . For convenience, there is a handle 6 arranged at the top portion 4 . A flexible tube 5 is arranged inside the compartment 17 formed by the side wall member 2 and the top 4 and bottom portions 3 . At the bottom portion 3 , there is a snap-in connection 18 for connecting a first end portion 19 of the flexible tube 5 to the bottom portion 3 . A second end portion of the tube 5 is connected at the first hole 12 of the top portion 4 inside the compartment.
[0063] The lid 7 is preferably arranged to be maintained in a closed position, e.g. by means of a snap-lock arrangement or the like. For example, a hook or the like may be arranged on the inner side of the lid, to engage with an indentation, hole or the like on the outer wall of the upper top portion 4 . Other type of locking arrangements are however also feasible. Further, the lid is preferably arranged to stay in an opened position when being opened. This may e.g. be accomplished by having non-planar surfaces in the hinge, a further snap-lock arrangement, or the like.
[0064] The lid 7 is further preferably arranged to extend outside the edge of the upper top portion, as best seen in FIG. 2 . Hereby, the opening procedure is facilitated, and opening can e.g. be effected by using the side of the hand, an edge of a table, sink or the like. Thus, opening is made simple also for users with reduced dexterity.
[0065] The side wall 2 is made from a flexible sheet material. The material may be a plastic material such as polypropylene, polyimide, polyethylene, EBA, or combinations thereof. The side wall member 2 of the illustrated embodiment is cylindrical in the expanded state. The flexible tube 5 may be made from silicone. The flexible tube 5 may further be twisted such that if the container 1 is in a collapsed state, as illustrated in FIG. 3 b , the flexible tube 5 is curled up. A second through-hole is arranged in the top portion 4 . Pressurized air may be supplied through the second hole 13 for pressurizing the compartment 17 when in use. In one embodiment, a temperature sensor is arranged on the side wall member 2 . Further aspects of the container 1 will now be described with reference to FIG. 2 .
[0066] FIG. 2 illustrates a cross-section of the container 1 in FIG. 1 with the cross-section taken along A-A′. In FIG. 2 the cross-section is taken of the container 1 when assembled. In FIG. 2 , it is visible a container 1 which comprises a side wall member 2 , a rigid bottom portion 3 , a rigid top portion 4 , a flexible tube 5 , a handle 6 , a first lid 7 , a pressure valve 8 , and a second lid 9 . In this configuration, the flexible tube 5 is connected at a first end portion 19 to the bottom portion 3 at the snap-in connection. The flexible tube 5 is connected at a second end portion 21 to the top portion 4 at the first hole 12 and is in fluid connection with the first hole 12 such that fluid may flow though the tube 5 and through the first hole 12 . The container 1 is configured such that if the compartment is pressurized, for example by inserting pressurized air through an opening or by pressurizing the compartment by any other means, a liquid stored in the compartment will flow through the flexible tube 5 through the first hole 12 . The flexible tube 5 is connected at the bottom portion 3 which may facilitate emptying the container 1 when in use. The rigid bottom portion 3 enables a stable up-right position of the container 1 .
[0067] The flexible side wall is preferably made of transparent or semi-transparent material. The side wall may further be provided with markings indicating a volume scale, relatable to the surface level of the liquid within the container. Hereby, it is possible to determine the volume that has been filled, the volume that has been pumped during use, etc. The scale may be arranged from the bottom with upwardly increasing numbers, or from the top, with downwardly increasing numbers. Since the container preferably has a uniform cross-sectional shape in the height direction, the scale may be linear.
[0068] The flexible side wall is preferably connected around the outer sides of the top and bottom portions, and may be connected by welding, adhesion, shrink fitting, etc, or a combination of these.
[0069] When the container is filled, and also when the container is pumped by pumping air into the container, the container will be relatively stable even though a very flexible material is used in the side wall. However, it is preferred to use a flexible material which has some degree of form stability.
[0070] The rigid top portion is preferably provided with an outwardly protruding, upwardly convex shape. Such a shape makes the top portion more rigid and stable.
[0071] The rigid bottom portion is preferably also provided with an outwardly protruding, downwardly concave shape. Hereby, the bottom of the container is interiorly bowl-shaped, having the lowest part at, or in the vicinity of, the center of the bottom portion, where the snap-in connection 18 for connecting a first end portion 19 of the flexible tube 5 is arranged. This ensures that very efficient drainage is made possible, allowing the container to be almost completely emptied, without any risk of pumping air instead of liquid. On the outside of bottom portion, a flat bottom area may be provided, or alternatively, as is shown in e.g. FIG. 2 , an outer, and downwardly protruding rim may be provided, to ensure that the container is stable when standing on e.g. the floor.
[0072] Collapsing of the container 1 will now be described with reference to FIG. 3A and FIG. 3B where different states of the collapsible container 1 are illustrated.
[0073] The illustrated embodiment in FIG. 2 illustrates the container in an expanded state, whereas FIGS. 3A and 3B illustrates the same container in a partly collapsed state and a collapsed state, respectively. In FIG. 3B , the container 1 has been collapsed along a longitudinal axis 20 of the container 1 . In this state, the top portion 4 and the bottom portion 3 are relatively closer to each other as compared to in the partly collapsed state shown in FIG. 3A . The flexible tube 5 is twisted such that if the container 1 is in the collapsed state the flexible tube 5 is curled up. In one embodiment the top portion 4 is relatively rotated with respect to the bottom portion 3 in the expanded state as compared to in the collapsed state. The rotation is in a plane essentially perpendicular to the longitudinal axis of the container 1 . A height of the container 1 in the collapsed state, from the top portion 4 to the bottom portion 3 , is less than ½ the height of the expanded state, and preferably less than ⅓, and more preferably less than ¼, and even more preferred less than ⅕. In various embodiments, an element, for example a pivotally connected snap-in connection, is arranged to maintain the container 1 in the collapsed state. In an embodiment, the top 4 and bottom portion 3 are in contact with each other in a collapsed state.
[0074] In FIG. 4 , an even more collapsed state is illustrated. Here, the height of the collapsed container essentially corresponds to the heights of the top and bottom portions. In FIG. 4A , the collapsed container is retained in this state by means of locking means formed as a band 21 , which is attached to one of the top and bottom portions, and which may be reversibly wrapped around the opposite portion. The band may be made of an elastic, stretchable material, but other materials are also useable. The band may also function as, or replace one of the above-discussed handles. In FIG. 4A , the band is fixedly connected at both ends. However, alternatively, the band may be releasably connected at one end, as is schematically illustrated in FIG. 4B . Here, a hook 22 or the like is provided, on which a hole in the band 21 may be fixed when in the connected disposition. An alternative locking arrangement is illustrated in FIG. 4C . Here, the locking means comprises locking fingers or hooks 23 , being pivotably connected to one of the portions, and which may be pivoted into a locked state around the opposite portion.
[0075] The above-discussed collapsible container is particularly useful as a reservoir in an irrigation system. Such an irrigation system, which is schematically illustrated in FIG. 5 , typically comprises a reservoir, formed by the collapsible container 1 , and arranged to house an irrigation liquid, a probe 20 for arrangement in a user, and a control unit 30 .
[0076] Tubing connecting the reservoir to the rest of the irrigation system may be provided through the openings in the top portion of the collapsible container, but additional openings may also be provided.
[0077] In order to render the irrigation system as portable as possible, the container preferably has a capacity of less than 5 litres, more preferred less than 3 litres and most preferred less than 2 litres. If however the system is to be used for repeated irrigation, a larger capacity container may be necessary.
[0078] As discussed previously, the container preferably comprises an overpressure release valve, to release pressure over a predetermined maximum pressure to be allowed. Further, the reservoir preferably comprises a filter, such as a hydrophobic filter, which is impermeable to the irrigation liquid, but which allows air to enter the reservoir but not escape the reservoir. Such a filter ensures that the reservoir maintains its shape when irrigation liquid is being pumped out from the reservoir. This is of advantage, since it makes the reservoir more stable. It also makes it possible to use less costly materials and less rigid containers when producing the reservoir, thereby making the production more cost-efficient. This ensures that the reservoir remains stable during irrigation. However, alternative means for obtaining this are also feasible. For example, the reservoir may simply be provided with an air inlet, possibly provided with a back-valve to prevent outflow of irrigation liquid, should the irrigation liquid reach the inlet.
[0079] For pumping, one or several manual and/or electric pump(s) may be used. The pump(s) may be arranged to pump liquid from the container directly, or to pump air or any other gas into the container to provide an overpressure which effects pumping, in the above-discussed manner.
[0080] The probe 40 is preferably provided with a retention member, such as an inflatable balloon 41 , for fixing the catheter in a body cavity. Further, the probe may be provided with a rearward enlarged part 42 , providing an abutment to hinder too deep insertion. The probe is provided with two lumens—one lumen for transfer of irrigation liquid through the probe, for discharge at the forward end, and one lumen for inflation and deflation of the balloon.
[0081] The control unit may be realized as a unitary, hand-held unit. The control unit may comprise a display 33 , and one or several control elements 34 , 35 and 36 .
[0082] Tubing is arranged to connect the reservoir, control unit and probe together. Preferred materials for the bulb pumps and the balloon can be any suitable material e.g. such as PVC, latex, TPE or PU. However, other materials providing similar properties can likewise be used.
[0083] The irrigation liquid can be any liquid which is capable of irrigation the body cavity of interest. In order to stimulate bowel movements suitable irrigation liquids includes water, hypertonic aqueous salt solutions, solutions or suspensions of cathartic agents, such as bisacodyl or phenolphthalein, and mineral oil.
[0084] The person skilled in the art realizes that the present invention is not limited to the preferred embodiment. For example, the side wall member may be of a different shape than the described cylindrical shape. It may for example have a polygonal shape in a cross-section comprising a circumference of the side wall member. Furthermore, the pressure, volume and temperature of the liquid in the container are not limited to what is described in the embodiments, but are merely an example. Materials mentioned are examples and are not limiting the invention. Further, the collapsible container is particularly suitable for use as a reservoir for housing irrigation liquid for use in an irrigation system for rectal or urethral irrigation. However, the collapsible container may also be used in many other types of medical procedures and systems. Further, the collapsible container may be arranged so that the liquid is pumped directly from the container, or indirectly, by providing a pressure inside the container. The container may also be used for receiving liquid during a medical procedure.
[0085] Such and other obvious modifications must be considered to be within the scope of the present invention, as it is defined by the appended claims. It should be noted that the above-mentioned embodiments illustrate rather than limit the invention, and that those skilled in the art will be able to design many alternative embodiments without departing from the scope of the appended claims. In the claims, any reference signs placed between parentheses shall not be construed as limiting to the claim. The word “comprising” does not exclude the presence of other elements or steps than those listed in the claim. The word “a” or “an” preceding an element does not exclude the presence of a plurality of such elements. Further, a single unit may perform the functions of several means recited in the claims. | A container for medical use forming a closed compartment for carrying a pressurized liquid includes a side wall member; a rigid bottom portion; a rigid top portion having a through hole; a lid arranged to cover and seal a filling hole; a pressure valve; and a flexible tube arranged inside the closed compartment. The first end of the flexible tube being provided with an opening towards the closed compartment and the second end of the flexible tube is connected to the top portion and in fluid communication with the through hole in the rigid top portion. The side wall member is flexible such that said container is reversibly foldable and unfoldable to be arrangeable in a compact state and an expanded state. | 0 |
TECHNICAL FIELD
[0001] The present invention relates to methods for monitoring treatment of Helicobacter infection and in particular to methods for monitoring eradication of Helicobacter pylori infection using immunoglobulin G2 (IgG2). The invention also relates to methods for predicting the likelihood of successful eradication of Helicobacter infection in a subject to be treated or being treated for the infection and in particular, to methods for predicting the likelihood of successful eradication including determining the levels of interleukin-4, interferon-γ and IgG in the subject to be, or being treated.
BACKGROUND ART
[0002] Any discussion of the prior art throughout the specification should in no way be considered as an admission that such prior art is widely known or forms part of common general knowledge in the field.
[0003] [0003] Helicobacter pylori infection is now recognised as an essential pre-requisite for the development of gastric cancer. About 30% of the population become infected with this bacterium and commonly present with chronic gastritis. This may be complicated by gastric or duodenal ulceration, or may present as non-ulcer dyspepsia A sizeable number of carriers are asymptomatic. However, in a small number of patients with H. pylori , their condition evolves through stages (including epithelial cell metaplasia and dysplasia) into neoplasia.
[0004] Current Management Practice of H. pylori Infection
[0005] Eradication of infection with antibiotics induces an 80-90% cure rate of peptic ulceration. A widely accepted treatment paradigm is based on detection of infection using antibody assays, followed by combination antibiotic therapy without prior endoscopic diagnosis. Endoscopy, before eradication therapy is generally accepted when ‘danger’ symptoms (eg, severe pain, bleeding) occur, or a significant risk of gastric cancer is present However, endoscopy is a procedure which is associated with its own risks and is to be avoided if possible.
[0006] [0006] H. pylori initiates an IgG antibody response in saliva as well as serum. The serum IgG antibody is the basis of non-invasive diagnosis. Eradication of infection is followed by a very slow fall in serum antibody levels. There has been a study which suggests that IgG antibody levels at 6 months may be of value in assessing successful eradication. Saliva levels of IgG antibody however fall much quicker following eradication, with levels at 6 weeks regularly less than 80% of those prior to antibiotic therapy.
[0007] The concept that saliva IgG antibody levels may predict successful eradication, while attractive, proved not to be a practical proposition for monitoring of progress of treatment or eradication of Helicobacter because total IgG antibody levels were unstable to the extent that a viable test in clinical circumstances proved unreliable. At present, no non-invasive stable test exists which would allow successful monitoring of treatment designed to eradicate Helicobacter infection.
[0008] Further, in addition to monitoring eradication of H. pylori in individuals treated, it would be desirable to have a test which could be used prior to, or during treatment to determine the likelihood of successful eradication of H. pylori.
[0009] It is an object of the present invention to overcome or ameliorate at least one of the disadvantages of the prior art, or to provide a useful alternative.
SUMMARY OF THE INVENTION
[0010] According to a first aspect there is provided a method of monitoring eradication of Helicobacter infection in a subject treated for the infection, including:
[0011] a) determination of IgG2 anti- H. pylori antibody level in a saliva sample;
[0012] b) comparison of the IgG2 anti- H. pylori antibody level with a predetermined control IgG2 anti- H. pylori antibody level, wherein a reduction in the level of IgG2 anti- H. pylori antibody in the saliva sample compared to the control indicates eradication of Helicobacter.
[0013] According to a second aspect there is provided a method of monitoring efficacy of treatment of Helicobacter infection in a subject treated for the infection, including:
[0014] a) determination of IgG2 anti- H. pylori antibody level in a saliva sample;
[0015] b) comparison of the IgG2 anti- H. pylori antibody level with a predetermined control IgG2 anti- H. pylori antibody level, wherein a reduction in the level of IgG2 anti- H. pylori antibody in the saliva sample compared to the control indicates efficacious treatment of Helicobacter.
[0016] According to a third aspect there is provided a method of monitoring relapse or reinfection with Helicobacter in a subject treated for infection with Helicobacter, including:
[0017] a) determination of IgG2 anti- H. pylori antibody level in a saliva sample;
[0018] b) comparison of the IgG2 anti- H. pylori antibody level with a predetermined control IgG2 anti- H. pylori antibody level, wherein an increase in the level of IgG2 anti- H. pylori antibody in the saliva sample compared to the control indicates relapse or reinfection with Helicobacter.
[0019] According to a fourth aspect there is provided a method of detecting unresponsiveness of a subject to treatment of Helicobacter infection, including:
[0020] a) determination of IgG2 anti- H. pylori antibody level in a saliva sample;
[0021] b) comparison of the IgG2 anti- H. pylori antibody level with a predetermined control IgG2 anti- H. pylori antibody level, wherein lack of change in the level of IgG2 anti- H. pylori antibody in the saliva sample compared to the control indicates lack of response to treatment.
[0022] According to a sixth aspect there is provided a kit for monitoring treatment of Helicobacter infection, including,
[0023] a) Helicobacter antigen
[0024] b) reagent for determining IgG2 subclass antibody.
[0025] Preferably, the IgG2 anti- H. pylori antibody is detected by a near-subject assay. The assay may, however, also be a laboratory-based test. Preferably, the assay is an antibody assay although it will be understood that other known methods of measurement can also be effectively used. Most preferably, the assay is an immunoassay such as ELISA, RIA or a similar assay format.
[0026] Control levels of IgG2 anti- H. pylori antibody can be established in samples of saliva obtained from normal individuals, ie. those not having an established H. pylori infection. It is preferred however that control levels of IgG2 be determined in subject's own saliva prior to commencement of treatment for infection or, if monitoring relapse or reinfection, the levels of salivary IgG2 following successful eradication of Helicobacter.
[0027] According to a seventh aspect, the present invention provides a method of predicting the likelihood of successful eradication of Helicobacter infection in a subject to be treated or being treated for the infection, including:
[0028] (i) determination of IL-4 level in a sample from the subject;
[0029] (ii) comparison of the IL-4 level with a predetermined control or standard L-4 level,
[0030] (iii) wherein a level of IL-4 in the sample from the subject above the control or standard IL-4 level is predictive of the likelihood of successful eradication and a level of IL-4 below the control or standard IL-4 level is predictive of the likelihood of eradication failure.
[0031] Preferably, the sample is a blood sample.
[0032] Preferably, the IL-4 is detected by an immunoassay and more preferably, it is determined by ELISA.
[0033] The skilled addressee will readily be able to identify a suitable control or standard IL-4 level. For example, the control or standard level of IL-4 may be established from analysis of samples obtained from subjects not infected by H. pylori and/or subjects having successfully eradicated H. pylori and/or subjects infected by H. pylori.
[0034] According to an eighth aspect, the present invention provides a method of predicting the likelihood of successful eradication of Helicobacter infection in a subject to be treated or being treated for the infection, including:
[0035] (i) determination of interferon-γ (INF-γ) level in a sample from the subject;
[0036] (ii) comparison of the INF-γ level with a predetermined control or standard INFIX level,
[0037] (iii) wherein a level of INF-γ in the sample from the subject below the control or standard INF-γ level is predictive of the likelihood of successful eradication and a level of IFN-γ above the control or standard level is predictive of the likelihood of eradication failure.
[0038] Preferably, the INF-γ level is determined in a blood sample.
[0039] Preferably, the INF-γ level is detected by an immunoassay and preferably the assay is ELISA.
[0040] The skilled addressee will readily be able to establish a suitable control or standard. For example, the control or standard level of INF-γ may be established from analysis of samples obtained from subjects not infected by H. pylori and/or subjects having successfully eradicated H. pylori and/or subjects infected by H. pylori.
[0041] According to a ninth aspect, the present invention provides a method of predicting the likelihood of successful eradication of Helicobacter infection in a subject to be treated or being treated for the infection, including:
[0042] (i) determination of immunoglobulin G (IgG) level in a sample from the subject;
[0043] (ii) comparison of the IgG level with a predetermined control or standard IgG level,
[0044] (iii) wherein a level of IgG in the sample from the subject below the control or standard level is predictive of the likelihood of successful eradication and a level of IgG above the control or standard level is predictive of the likelihood of eradication failure.
[0045] Preferably, the IgG level is determined in a serum sample and, more preferably, the sample is a saliva sample.
[0046] The skilled addressee will readily be able to establish a suitable control or standard level of IgG. For example, the control or standard level of IgG may be established from analysis of samples obtained from subjects not infected by H. pylori and/or subjects having successfully eradicated H. pylori and/or subjects infected by H. pylori.
[0047] According to a tenth aspect, the present invention provides a method of predicting the likelihood of successful eradication of Helicobacter infection in a subject to be treated or being treated for the infection, including:
[0048] (i) determination a combination of IL-4 and/or INF-γ and/or IgG levels in a sample from the subject;
[0049] (ii) comparison of the IL-4 and/or INF-γ and/or IgG levels with a predetermined control or standard IL-4 and/or INF-γ and/or IgG level respectively,
[0050] wherein a level of IL-4 in the sample from the subject above the control or standard level is predictive of the likelihood of successful eradication and a level of IL-4 below the control or standard level is predictive of the likelihood of eradication failure, and
[0051] wherein a level of INF-γ in the sample from the subject below the control or standard level is predictive of the likelihood of successful eradication and a level of INF-γ above the control or standard level is predictive of the likelihood of eradication failure, and
[0052] wherein a level of IgG in the sample from the subject below the control or standard level is predictive of the likelihood of successful eradication and a level of IgG above the control or standard level is predictive of the likelihood of eradication failure.
BRIEF DESCRIPTION OF THE FIGURES
[0053] [0053]FIG. 1 Stability of salivary IgG2 anti- Helicobacter pylori antibody.
[0054] [0054]FIG. 2 Salivary IgG (panel A) and IgG2 (panel B) anti- H. pylori antibody before and after eradication of H. pylori.
[0055] [0055]FIG. 3 Salivary IgG (panel A) and IgG2 (panel B) anti- H. pylori antibody in subject with and without H. pylori infection.
[0056] [0056]FIG. 4 Correlation between IL-4 production in whole blood and gastric tissue cultures. Whole blood cultures or gastric antrum biopsy cultures were incubated for 24 hours at 37° C., after which time the levels of IL-4 were measured by ELISA capture assay. The results shown a correlation between mucosal and whole blood IL-4 (p<0.001).
[0057] [0057]FIG. 5 Levels of IL-4 in whole blood culture stimulated with H. pylori AGE antigen. Peripheral blood obtained from subjects with or without H. pylori infection, or with eradication failure was added to equal volume of AIM-V culture medium containing graded concentrations of H. pylori AGE antigen as indicated. After 24 hours of culture, levels of IL-4 were measured by ELISA capture assay. Results shown are the mean±standard error of the mean. *:p<0.05: compared with H. pylori -eradicated subjects; ¶: p<0.01 and p<0.05 compared with the values from subjects with H. pylori -eradicated and H. pylori -positive, respectively.
[0058] [0058]FIG. 6 INF-γ production in response to H. pylori acid-glycine extract stimulation in whole blood. Peripheral blood was collected from individual subject and cultured in the presence of graded concentration of H. pylori AGE antigen for 24 hours. Culture supernatants were collected and assayed for IFN-γ by ELISA. Results shown were mean±standard error of the mean. NS: Not Significant.
[0059] [0059]FIG. 7 Levels of specific H. pylori IgG antibody in serum and saliva. Serum and saliva samples were collected from individual subjects. Levels of specific H. pylori IgG were measured by ELISA. Results shown were mean±standard error of the mean. *: p<0.05 compared with mean from H. pylori -positive group; NS: Not Significant.
DESCRIPTION OF THE PREFERRED EMBODIMENTS
[0060] It has surprisingly been found that salivary IgG2 anti- H. pylori antibody is stable and allows a reliable test to be developed for monitoring progress of treatment and/or eradication of Helicobacter pylori infection in a subject undergoing treatment.
[0061] It was previously known that IgG anti- H. pylori antibody levels in blood and gastric mucosa can be used as an indicator of H. pylori status. There has been an attempt to use IgG anti- H. pylori antibody in saliva for a similar purpose but it proved to be unstable in such a sample. From the following examples it will be understood that while IgG anti- H. pylori may be useful as a general indicator of H. pylori status, it is the measurement of the IgG2 subclass anti- H. pylori antibody which allows a stable treatment monitoring test to be developed.
[0062] It has further surprisingly been found that IL-4 levels can be used as a predictor of successful eradication of H. pylori . It is envisaged that an IL-4 test could be used prior to, or during the treatment of H. pylori infection in order to predict the likelihood of eradication.
[0063] Techniques for measurement of antibodies and IL-4 in human samples are well-known in the art and protocols and reagents are readily available. Examples of some of the techniques used are indicated below as an illustration of how some measurements may be performed.
[0064] Unless indicated otherwise, standard techniques which can be ascertained from standard texts and laboratory manuals may be employed.
[0065] The invention will now be described in more detail with reference to non-limiting examples.
EXAMPLES
Example 1
Determination of Antibody Levels in Saliva Samples
[0066] Sample Collection
[0067] Saliva samples were collected from 4 patients infected with H. pylori who were treated with eradication triple therapy comprised of amoxycillin, omeprazole and clarithromycin for seven days. Samples were taken before treatment and after 10 days of eradication therapy.
[0068] [0068] H. pylori Antigen Preparation
[0069] [0069] H. pylori NCTC 11637 strain was used for H pylori antigen preparation according to modified methods described by Goodwin (#208). Protein concentration in the extract was measured using a bio-rad kit (Bio-rad laboratories Australia). Aliquots were stored at −70° C.
[0070] Antibody Detection by ELISA
[0071] For saliva anti- H. pylori antibody detection, wells of a 96-well flat-bottomed microtiter Polysorb plate (Nunc, Denmark) were coated with 7 μg/mL of H. pylori antigen at 4° C. overnight. After washing and blocking the plates with 5% skim milk (Diploma, Australia) in PBS-Tween 20, saliva samples at 1:2 dilution with 2% PEG 6000 were added to individual wells in triplicate. After incubation, the wells were washed and horseradish peroxidase conjugated-sheep anti-IgG or anti-IgG2 (Silenus, Australia) at 1:2000 dilution was added to each well. Following a further incubation, the plates were washed and then tetramethyl benzidine (TMB) substrate (Sigma, USA) was added to each well. The reaction was stopped using 1 mol/L H 2 SO 4 and the absorbance was read at 450 nm in an ELISA plate reader (BioRad 450, Japan). The results were expressed as ELISA INDEX being the mean OD 450 of a given saliva sample divided by the mean OD 450 of the calibrating sample. Positive and negative quality control samples were included in each run to control for intra- and inter-assay variation.
[0072] Saliva samples were obtained from 5 subjects infected with H. pylori . The samples were tested for IgG2 and total IgG anti- H. pylori antibody by the ELISA assay either fresh or after storage for up to 12 months. The results show that IgG2 antibody levels were more stable than IgG antibody levels (FIG. 1). Hence, IgG2 antibody is a reliable and a sensitive indicator of infection status due to its stability during storage and assay.
Example 2
Anti- H. pylori Antibody Levels in Saliva from Patients Undergoing Eradication therapy.
[0073] Saliva samples from subjects undergoing antibiotic eradication therapy were tested for anti- H. pylori antibody using the immunoassay method described in Example 1.
[0074] IgG and IgG2 antibody was measured before and after treatment with antibiotics. Ten days after treatment IgG2 antibody levels fell quicker than total IgG antibody levels (FIGS. 2A and 2B).
[0075] In a separate study it was shown that saliva from subjects with H. pylori infection have markedly elevated levels of IgG2 (FIG. 3A) when compared to subjects without infection (FIG. 3B). Subjects who failed to ultimately eradicate the infection did not demonstrate a significant drop in the level of IgG2 anti- H. pylori antibody.
Example 3
Interleukin-4/IFN-γ and IgG Studies
[0076] Subjects
[0077] Fifty-two subjects referred for investigation of dyspepsia, and 11 subjects with persistent H. pylori infection following one or more courses of antibiotics, were recruited for this study. Subjects with dyspepsia had not taken antibiotics within three months of the study. The study was approved by the Ethics Committee of the Centre for Digestive Diseases, Sydney, Australia Informed consent was obtained from all patients. Multiple biopsy specimens were obtained during upper gastrointestinal endoscopy from the antrum and the body of the stomach to be used for tissue culture, histology and a urease test (CLO test, Delta West, WA, Australia). Blood samples were incubated at 37° C. within 2 hours of collection. Serum was stored at −70° C. for H. pylori specific antibody.
[0078] Saliva Sample Collection
[0079] Saliva samples were collected before the endoscopy procedure. Samples were centrifuged at 1000×g for 10 minutes at 4° C., and aliquots were stored at −70° C.
[0080] Biopsy Culture
[0081] Gastric biopsy tissues were weighted and cultured at a ratio of 50 μL serum-free AIM-V medium (Life Technology, Australia) per mg tissue (wet weight) for 24 hours. The culture supernatants were collected and centrifuged. Aliquots were stored at −70° C. until assay.
[0082] [0082] H. pylori Antigen Preparation
[0083] [0083] H. pylori antigens from the NCTC 11637 strain were prepared by acid-glycine extraction (AGE) according to the method described by Goldwin et al ( J Infect Dis 1987; 155:488-94). H. pylori AGE was used for cell culture and specific antibody measurement.
[0084] ELISA Capture Assay for IL-4 in Whole Blood Culture
[0085] Cytokine levels in whole blood culture were measured following the method described previously (Ren et al, Helicobacter 2000; 5:135-41). Briefly, 150 AL of heparinized whole blood was added in triplicate to wells of a 96-well microtitre flat-bottomed plate pre-coated with mouse polyclonal anti-human IL-4 antibody (Endogen, MA, USA). An equal volume of AIM-V medium containing H. pylori AGE at either 0, 1 or 10 μg/mL was also loaded to wells. The cultures were incubated at 37° C. with 5% CO 2 for 24 hours, after which time supernatants were collected for interferon-γ (IFN-γ) assay. The amount of ‘captured’ IL-4 was measured by ELISA as following. Briefly, after washing the plates, biotinylated mouse monoclonal anti-human IL-4 antibody (Endogen, MA, USA) was added (0.5 μg/mL) to wells and incubated for 90 minutes at room temperature. The plates were then washed and incubated for a further 30 minutes at room temperature with streptavidin-conjugated horseradish peroxidase (Selinus, Australia) at a 1:400 dilution. The plates were thoroughly washed with washing buffer and finally incubated for 10 minutes at room temperature with 3,3′-5,5′ tetramethyl benzidine (TMB, Sigma-Aldrich, USA) substrate. The reaction was stopped using 1 mol/L H 2 SO 4 and optical density at 450 nm (OD 450 nm) was measured in an ELISA plate reader (Bio-Rad 450, Japan). Standard IL-4 (Endogen, MA, USA) was applied for each plate to control plate to plate variation. The limits of sensitivity for IL-4 was 9.4 μg/mL. The amount of IL-4 in samples was determined using a Softmax program (Version 2.3 FPU, USA).
[0086] INF-γ ELISA Assay
[0087] Wells of a 96-well flat-bottomed microtitre plate (Nunc, Denmark) were coated with mouse anti-human IFN-γ monoclonal antibody (Endogen, MA, USA) at 2 μg/1 mL overnight at 4° C. After washing and blocking, supernatants from whole blood culture or IFN-γ standards (Endogen, MA, USA) were added in duplicate, and incubated for 90 minutes. The plates were washed and biotinylated mouse monoclonal anti-human IFN-?γ antibody (Endogen, MA, USA) was added (0.25 μg/mL). After 90 minutes incubation, the wells were washed and streptavidin-conjugated horse-radish peroxidase (Selinus, Australia) was applied at a 1:2000 dilution. The plates were washed and TMB chromagen (Sigma-Aldrich, USA) was added to each well. The absorbance was read at 450 nm in an ELISA plate reader (Bio-Rad 450, Japan). The limits of sensitivity for INF-γ was 9.4 μg/mL. The amount of IFN-γ in samples was determined using a Softmax program (Version 2.3 FPU, USA).
[0088] Detection of H. pylori Antibody
[0089] Wells of a 96-well flat-bottomed microtitre plate were coated with H. pylori AGE at 5 μg/mL at 4° C. overnight. After washing and blocking, serum samples at 1:3000 dilution and saliva sample at 1:4 dilution were added to wells in triplicate. Horse-radish peroxidase conjugated-sheep anti-IgG (Selinus, Australia) was applied at 1:2000 dilution. Tetramethyl Benzidine (TMB) substrate (Sigma-Aldrich, USA) was used for colour development. The absorbance was read at 450 nm in an ELISA plate reader (Bio-Rad, 450, Japan). The results were expressed as ELISA Units against a reference standard of pooled positive sera. Intra- and inter-assay variation was less than 10%.
[0090] Statistical Analysis
[0091] Data were expressed as mean±standard error (SE). Correlation Z test was used to test for a correlation between mucosal and blood cytokine production. Differences of means among patient groups were analysed by ANOVA. All statistical analysis were performed by using a StatView 4.5 software program (Abacus Concepts, California, USA). Significant difference was considered when p value was less than 0.05.
[0092] Results
[0093] Subjects were divided into four groups according to H. pylori infection status and results of antibiotic treatment. There were 23 H. pylori -negative subjects; 20 H. pylori -positive subjects; 9 subjects with successful H. pylori eradication confirmed by histology or C 14 breath test at 6-8 weeks after eradication therapy; and 11 subjects with H. pylori resistance following antibiotic therapy. Details of diagnosis and therapeutic regimens in subjects with eradication failure are shown in Table 1.
[0094] Comparison of Blood and Mucosal IL-4 Response
[0095] To determine whether there is a correlation between blood and mucosal cytokine responses to H. pylori infection, levels of IL-4 production in whole blood cultures stimulated or unstimulated with H pylori antigens, were compared with levels in gastric mucosa cultures (FIG. 1) (data from antigen stimulated cultures not shown). The results from H pylori positive (n=6) and negative subjects (n=11) and subjects with failed eradication (n=8) showed that IL-4 production in whole blood cultures (stimulated or unstimulated) correlated with that in gastric mucosa (r 2 =0.549, p<0.001).
[0096] IL-4 and IFN-γ Production in Whole Blood Culture
[0097] Significantly lower levels of IL-4 were detected in whole blood stimulated or unstimulated with H. pylori AGE from subjects with eradication failure compared with subjects in whom H. pylori was successfully eradicated (p<0.05, 0 and 1.0 μg/mL H. pylori AGE; p<0.01, 10 μg/mL H. pylori AGE) or in subjects with untreated infection (p<0.05, 10 μg/mL H. pylori AGE) (FIG. 2). IL-4 levels were similar in non-infected and infected subjects, and were not significantly different when compared to subjects with successful eradication (though there was a trend towards increased levels following eradication). Although there was no statistically significant difference in the levels of IFN-γ between the different groups, lower levels were detected in subjects with successful H. pylori eradication (FIG. 3). Low levels of IL-4 secretion were seen in most subjects with ongoing infection with resistant H. pylori, irrespective of the number of courses of therapy (Table 2).
[0098] Anti- H. pylori IgG Levels in Serum and Saliva
[0099] Both serum and saliva IgG antibody levels were significantly lower in non-infected subjects (p<0.05) and in subjects at 6-8 weeks after eradication therapy (p<0.05) than in subjects who were positive for H. pylori. For both saliva and serum antibody, a trend towards lower levels of antibody in those failing to eradicate infection was seen, but this was short of statistical significance (FIG. 4).
TABLE 1 Clinical Characterisation of Subjects with Failed Antibiotic Therapy Number of Age Antibiotic Duration No. (years) Diagnosis Treatment Regimens Used Courses (months) 1 40 Hp-induced gastritis metronidazole/amoxicillin/bismuth/ranitidine HCl 1 24 clarithromycin/metronidazole/lansoprazole/amoxicillin 2 2 58 Hp-induced gastritis Losec HP7 1 12 3 55 Oesophagitis and Hp-induced gastritis Klacid HP7 1 >3 yrs Helidac/ranitidine HCl 1 lansoprazole 1 4 47 Hp-induced gastritis Losec HP7 2 20 5 37 Hp-induced gastritis metronidazole 1 5 Losec HP7 3 6 45 Hp-induced gastritis Losec HP7/ranitidine HCl 3 28 7 27 Hp-induced gastritis Losec HP7 3 6 clarithromycin/tetracycline/metronidazole/lansoprazole 1 8 33 Hp-induced gastritis and Helidac 2 >3 yrs duodenal ulcer disease 9 26 Hp-induced gastritis Losec HP7 2 10 10 47 Hp-induced gastritis Losec HP7 3 >3 yrs 11 73 Oesophagitis, Hp-induced gastritis and Losec HP7 3 >3 yrs duodenal ulcer disease
[0100] [0100] TABLE 2 IL-4 and H. pylori Antibody IgG in Subjects with Failure Eradication IL-4 levels H. pylori (pg/mL)* Antibody IgG* Times of No. H. pylori antigen H. pylori antigen H. pylori antigen Serum Saliva failure Subjects (0 μg/mL) (1 μg/mL) (10 μg/mL) (ELISA Unit) (ELISA Unit) One 1 20.76 28.21 44.20 214 116.3 Two 3 40.49 ± 29.36 54.07 ± 43.14 65.22 ± 45.86 224 ± 101.58 1000.2 ± 866.5 Three 5 45.16 ± 36.16 53.34 ± 44.34 55.63 ± 44.19 410.95 ± 167.29 418.9 ± 151.96 Four 2 18.82 ± 9.82 22.56 ± 13.58 12.60 ± 3.6 1453.6 ± 1244.4 523.7 ± 235.3
[0101] The skilled addressee will understand that, in light of the above, IL-4, INF-γ and IgG can be used to predict the likelihood of successful eradication of Helicobacter infection before or during treatment of the infection. As a corollary, it will be clear that the method can also be used to identify subjects unlikely to respond to treatment for Helicobacter infection.
[0102] Although the invention has been described with reference to specific examples, it will be appreciated by those skilled in the art that the invention may be embodied in many other forms without departing from the spirit or intent of the inventive concept. | The present invention relates to methods for monitoring treatment of Helicobacter infection and in particular to methods for monitoring eradication of Helicobacter pylori infection using immunoglobulin G2 (IgG2). The invention also relates to methods for predicting the likelihood of successful eradication of Helicobacter infection in a subject to be treated or being treated for the infection and in particular, to methods for predicting the likelihood of successful eradication including determining the levels of interleukin, interferon-γ and IgG in the subject to be, or being treated. | 6 |
BACKGROUND OF THE INVENTION
[0001] 1. Field of the Invention
[0002] The present invention relates to a novel process for preparing dimethyl ether, performed in such a manner that methanol is initially dehydrated over a hydrophilic solid acid catalyst and then unreacted methanol is continuously dehydrated over hydrophobic zeolite solid acid catalyst in the co-existence of the unreacted methanol and the products generated from the initial dehydration (dimethyl ether and water), which enables methanol dehydration to proceed in a more efficient manner. Therefore, the dimethyl ether useful as a clean fuel and a raw material in chemical industry may be obtained in higher yield.
[0003] 2. Description of the Related Art
[0004] Dimethyl ether has been acknowledged as a principal material having diverse applicabilities in chemical industry such as aerosol propellant and it has been recently approved as a clean fuel. Further, dimethyl ether would soon be able to replace some conventional fuels used for internal combustion engines and thus development of an economic process for its preparation is in high demand in the art.
[0005] Most of the processes for preparing dimethyl ether performed in industrial scale are carried out via dehydration of methanol as represented by the following Scheme I:
2CH 3 OH→CH 3 OCH 3 +H 2 O (I)
[0006] The preparation process of dimethyl ether via dehydration of methanol is performed at a temperature of 250-450° C. and commonly uses a solid acid catalyst. The reactant is passed through a fixed reactor charged with the solid acid catalyst. The solid acid catalyst useful in the process for preparing dimethyl ether includes gamma-alumina Japanese Patent Kokai 1984-16845), silica-alumina (Japanese Patent Kokai 1984-42333) and so on. However, water is very likely to adsorb on the surface of the gamma-alumina or silica-alumina due to its hydrophilicity, which leads to lowering active site thus decreasing its catalytic activity. Therefore, where hydrophilic gamma-alumina or silica-alumina is used as a catalyst for methanol dehydration, it is generally observed that the catalyst bed at the top of reactor shows effective dehydration but that at the bottom of reactor shows lower activity due to water generated during dehydration.
[0007] In this regard, there is need in the art for developing a novel catalyst system to overcome the shortcomings of the conventional techniques and permit the preparation of dimethyl ether in higher yield. To comply with the need, the process using hydrophobic zeolite catalyst has been suggested. However, where anhydrous methanol is used as a raw material, the catalyst deactivation occurs due to coke formation ( Bull. Korean Chem. Soc., 24:106(2003)).
SUMMARY OF THE INVENTION
[0008] The present inventors have carried out intensive researches to develop a novel process to surpass, in view of the yield of dimethyl ether, the conventional processes using hydrophilic solid acid catalyst such as gamma-alumina and silica-alumina. As a result, the present inventors have discovered that a dual-charged catalyst system comprising the upper part of a reactor charged with the hydrophilic solid acid catalyst such as gamma-alumina and silica-alumina and the lower part of a reactor charged with the hydrophobic zeolite catalyst, has catalyzed methanol dehydration with greater efficiency and enabled the catalysts to exhibit high activity for a long period of time, so that dimethyl ether may be given in higher yield. That is, the present inventors have found that the dual-charged catalyst system permitting the processes, performed in such a manner that methanol is initially dehydrated over a hydrophilic solid acid catalyst and then unreacted methanol is continuously dehydrated over hydrophobic zeolite solid acid catalyst in the co-existence of the unreacted methanol and the products generated from the initial dehydration (dimethyl ether and water), has enabled methanol dehydration to proceed in a more efficient manner. Based on the novel findings described above, the present invention has been finally completed.
[0009] Accordingly, it is an object of this invention to provide a process for preparing dimethyl ether, which employs a dual-charged catalyst system comprising the upper part of a reactor charged with the hydrophilic solid acid catalyst such as gamma-alumina and silica-alumina and the lower part of a reactor charged with the hydrophobic zeolite catalyst.
DETAILED DESCRIPTION OF THE INVENTION
[0010] In an aspect of this invention, there is provided a process for preparing dimethyl ether, which comprises the steps of: (a) dehydrating methanol by contacting with a hydrophilic solid acid catalyst; and (b) continuously dehydrating unreacted methanol by contacting with a zeolite as a hydrophobic solid acid catalyst in a state where said unreacted methanol and products generated from the step (a) coexist.
[0011] In particular, the present invention employs a dual-charged catalyst system that comprises: the upper part of a reactor charged with the hydrophilic solid acid catalyst selected from gamma-alumina and silica-alumina and the lower part of a reactor charged with the hydrophobic zeolite catalyst whose SiO 2 /Al 2 O 3 ratio ranges from 20 to 200. This catalyst system allows to provide more efficient methanol dehydration, thereby permitting much higher yield in dimethyl ether production.
[0012] The present invention will be described in more detail hereunder:
[0013] The present invention is directed to a novel process for preparing dimethyl ether useful as a raw material in chemical industry and a clean fuel, using the dual-charged catalyst system comprising the upper part of a reactor charged with the hydrophilic solid acid catalyst selected from gamma-alumina and silica-alumina and the lower part of a reactor charged with the hydrophobic zeolite catalyst, which enables methanol dehydration to proceed in a more efficient manner. The present process shows much higher yield of dimethyl ether. Where the dual-charged catalyst system of the present invention is used, it accompanies with higher yield of dimethyl ether and also high activity of a given catalyst can be maintained for a long period of time. Therefore, the methanol dehydration can be proceeded in a most efficient way.
[0014] The performance of the dual-charged catalyst system could be maximized when the upper part of a reactor is charged with 50-95 vol % of the hydrophilic solid acid catalyst and the lower part of a reactor is charged with 5-50 vol % of the hydrophobic zeolite catalyst.
[0015] The hydrophobic zeolite catalyst used in the lower part of a reactor includes, but not limited to, USY, Mordenite, ZSM-type zeolite, Beta and the like. According to a preferred embodiment, its SiO 2 /Al 2 O 3 ratio ranges from 20 to 200. If SiO 2 /Al 2 O 3 ratio of the zeolite is below 20, its hydrophilicity becomes manifest resulting in the catalyst deactivation due to the adsorption of water under the condition. If SiO 2 /Al 2 O 3 ratio of the zeolite exceeds 200, the amount of its acid site becomes negligible thus being unable to perform the efficient methanol dehydration. The hydrophilic catalyst used in the upper part of a reactor is gamma-alumina or silica-alumina.
[0016] As a result, by use of novel catalyst system for methanol dehydration, the present invention allows accomplishing higher yield of dimethyl ether than sole gamma-alumina or silica-alumina, and maintaining the higher yield for a long period of time.
[0017] In the present catalyst system described previously, gamma-alumina or silica-alumina as the hydrophilic solid acid catalyst used in the upper part of a reactor can be prepared as follows: The common catalyst available from Strem chemicals Inc. may be used as gamma-alumina. Silica-alumina catalyst may be prepared in such a manner that colloidal silica (Aldrich, 40 wt % SiO 2 solution) is impregnated into gamma-alumina catalyst (Strem chemicals) according to a conventional impregnation method and dried at 100° C., followed by calcination. Thus prepared silica-alumina comprises 1-5 wt % of silica. As the hydrophobic zeolite catalyst used in the lower part of a reactor, USY, Mordenite, ZSM-type zeolite and Beta whose SiO 2 /Al 2 O 3 ratio ranges from 20 to 200 may be used.
[0018] The process for preparing dimethyl ether by methanol dehydration over the dual-charged catalyst system will be generalized as follows: After the lower part of a vertical reactor, in which the fluid is to flow downward, is charged with 5-50 vol % of hydrophobic zeolite catalyst based on the total volume of the catalyst and then the upper part of the reactor is charged with 50-95 vol % of hydrophilic solid acid catalyst, the dual-charged catalyst is pretreated at 200-350° C. with flowing inert gas such as nitrogen at 20-100 ml/g-catalyst/min. The methanol is flowed into a reactor for contacting with the catalyst bed pretreated as above. At that time, the reaction temperature is maintained at 150-350° C. If the reaction temperature is lower than 150° C., the reaction rate may not be sufficient, so that the methanol conversion is decreased; however, if it exceeds 350° C., the reaction is unfavorable for production of dimethyl ether in terms of thermodynamics, so that the methanol conversion is lowered. It is preferred that the reaction pressure be maintained in the range of 1-100 atm. If the pressure is higher than 100 atm, the unfavorable conditions occur in terms of reaction operation. In addition, it is preferred that LHSV (liquid hourly space velocity) for methanol dehydration range from 0.05 to 50 h −1 based on absolute methanol. If the liquid hourly space velocity is lower than 0.05 h −1 , the productivity may be negligible; when it exceeds 50 h −1 , the methanol conversion may be poor owing to shortened contact time for a catalyst.
[0019] As described previously, the present invention employs the dual-charged catalyst system comprising the layer of hydrophilic solid acid catalyst such as gamma-alumina or silica-alumina and the layer of hydrophobic zeolite in a fixed bed reactor in which the reaction fluid contacts in the order: said layer of hydrophobic zeolite, which enables methanol dehydration to proceed in a more efficient manner. Therefore, the dimethyl ether useful as a clean fuel and a raw material in chemical industry may be obtained in higher yield.
[0020] The following specific examples are intended to be illustrative of the invention and should not be construed as limiting the scope of the invention.
EXAMPLE 1
[0021] H-ZSM-5(SiO 2 /Al 2 O 3 =30) zeolite catalyst and gamma-alumina catalyst were separately molded to have a size of 60-80 meshes with a pelletizer. In a fixed bed reactor, in which the reaction fluid is to flow downward, the lower part was charged with 0.5 ml of the molded zeolite and the upper part was charged with 2.0 ml of the molded gamma-alumina. Then, nitrogen gas was passed into the reactor at a flow rate of 50 ml/min and the temperature of the reactor was adjusted to 270° C. The methanol was passed into the catalyst bed under a condition where a reactor temperature is 290° C., a pressure is 10 atm and LHSV is 7.0 h −1 . The results are shown in Table I.
EXAMPLE 2
[0022] H-Beta zeolite catalyst and silica-alumina (silica: 1 wt %) catalyst were molded to have a size of 60-80 meshes with a pelletizer. In a fixed bed reactor, in which the reaction fluid is to flow downward, the lower part was charged with 0.25 ml of the molded zeolite and the upper part was charged with 2.25 ml of the molded silica-alumina. Then, the methanol dehydration was performed as Example 1. The results are shown in Table I.
EXAMPLE 3
[0023] H-USY zeolite catalyst and silica-alumina (silica: 5 wt %) catalyst were separately molded to have a size of 60-80 meshes with a pelletizer. In a fixed bed reactor, in which the reaction fluid is to flow downward, the lower part was charged with 1.0 ml of the molded zeolite and the upper part was charged with 1.5 ml of the molded silica-alumina. Then, the methanol dehydration was performed as Example 1. The results are shown in Table I.
EXAMPLE 4
[0024] H-MOR (Mordenite) zeolite catalyst and gamma-alumina catalyst were separately molded to have a size of 60-80 meshes with a pelletizer. In a fixed bed reactor, in which the reaction fluid is to flow downward, the lower part was charged with 0.5 ml of the molded zeolite and the upper part was charged with 2.0 ml of the molded silica-alumina. Then, the methanol dehydration was performed as Example 1. The results are shown in Table I.
EXAMPLE 5
[0025] The reactions were carried out by use of the same catalyst system as Example 1 except that the temperature for methanol dehydration was changed to 250° C. The results are shown in Table I.
EXAMPLE 6
[0026] The reactions were carried out by use of the same catalyst system as Example 1 except that the LHSV for methanol dehydration was changed to 9 h −1 . The results are shown in Table I.
EXAMPLE 7
[0027] The reactions were carried out by use of the same catalyst system as Example 1 except that the temperature and LHSV for methanol dehydration was changed to 250° C. and 9 h −1 , respectively. The results are shown in Table I.
COMPARATIVE EXAMPLE 1
[0028] Gamma-alumina catalyst was molded to have a size of 60-80 meshes with a pelletizer and a fixed bed reactor was charged with 2.5 ml of the molded catalyst. The methanol dehydration was carried out under the same reaction conditions as Example 1. The results are shown in Table I.
COMPARATIVE EXAMPLE 2
[0029] Silica-alumina (silica: 5 wt %) catalyst was molded to have a size of 60-80 meshes with a pelletizer and a fixed bed reactor was charged with 2.5 ml of the molded catalyst. The methanol dehydration was carried out under the same reaction conditions as Example 1. The results are shown in Table I.
COMPARATIVE EXAMPLE 3
[0030] H-ZSM-5(SiO 2 /Al 2 O 3 =30) zeolite catalyst was molded to have a size of 60-80 meshes with a pelletizer and a fixed bed reactor was charged with 2.5 ml of the molded zeolite. The methanol dehydration was carried out under the same reaction conditions as Example 1. The results are shown in Table I.
COMPARATIVE EXAMPLE 4
[0031] 0.5 ml of H-ZSM-5(SiO 2 /Al 2 O 3 =30) zeolite catalyst and 2.0 ml of gamma-alumina catalyst that were molded to have a size of 60-80 meshes with a pelletizer, were mixed and then a fixed bed reactor was charged with the mixture. The methanol dehydration was carried out under the same reaction conditions as Example 1. The results are shown in Table I.
[0032] The following Table I summarizes the results from the methanol dehydration in Examples 1-7 and Comparative Examples 1-4.
TABLE I Yield of dimethyl ether (%) Catalyst (vol %*) After Lower Upper Temp. LHSV Ini- 100 Examples part part (° C.) (h −1 ) tial hr Ex. 1 H-ZSM-5 Gamma- 290 7 90.5 91.1 (20%) alumina (80%) Ex. 2 H-Beta 1% 290 7 85.4 85.8 (10%) silica- alumina (90%) Ex. 3 H-USY 5% 290 7 84.3 84.8 (40%) silica- alumina (60%) Ex. 4 H-MOR Gamma- 290 7 88.1 88.6 (20%) alumina (80%) Ex. 5 H-ZSM-5 Gamma- 250 7 83.3 83.1 (20%) alumina (80%) Ex. 6 H-ZSM-5 Gamma- 290 9 84.4 84.0 (20%) alumina (80%) H-ZSM-5 Gamma- 250 9 77.2 77.7 (20%) alumina (80%) Com. Gamma-alumina(100%) 290 7 67.0 66.8 Ex. 1 Com. 5% silica-alumina (100%) 290 7 69.3 69.2 Ex. 2 Com. H-ZSM-5(100%) 290 7 90.0 16.5 Ex. 3 Com. H-ZSM-5(20%) + Gamma- 290 7 89.5 61.7 Ex. 4 alumina (80%) *representing ratio of the catalysts used in the upper and lower parts
[0033] As indicated in Table I, the methanol dehydrations using the present catalyst system in Examples 1-7 show significantly higher yields (above 80%) in dimethyl ether production and higher catalyst stability.
[0034] On the contrary, in the methanol dehydration using the gamma-alumina catalyst conventionally used in the industry and methanol as a raw material, lower yields (below 70%) in dimethyl ether production were observed (see Comparative Example 1). Where the silica-alumina was used as a catalyst, the yield in dimethyl ether production was relatively low, similar to that of gamma-alumina catalyst. Therefore, it could be understood that the present catalyst system exhibits about 10% higher yield in dimethyl ether production than sole gamma-alumina catalyst or silica-alumina.
[0035] In case of using sole H-ZSM-5 zeolite as a catalyst, although its initial activity was very high (the yield of dimethyl ether: 90%), the catalyst deactivation was manifest with time on stream due to coke formation, so that the yield of dimethyl ether was decreased to below 20% after 100 hr of reaction time (Comparative Example 3). Such operation was also observed when using the mixture of H-ZSM-5 zeolite and gamma-alumina without the localization in the bed.
[0036] Therefore, it could be appreciated that according to the present catalyst system, methanol is initially dehydrated over a hydrophilic solid acid catalyst including gamma-alumina or silica-alumina and then unreacted methanol is dehydrated by a zeolite, used as a hydrophobic solid acid catalyst, in the co-existence of the unreacted methanol and the products generated from the initial dehydration (dimethyl ether and water). During the latter dehydration, the formation of coke from the hydrophobic solid acid can be prevented by water, thus maintaining the catalyst activity.
[0037] As described above, the present invention employs the dual-charged catalyst system comprising the upper part of a reactor charged with the hydrophilic solid acid catalyst such as gamma-alumina and silica-alumina and the lower part of a reactor charged with the hydrophobic zeolite catalyst such as USY, Mordenite, ZSM-type zeolite and Beta, which enables the catalysts to exhibit high activity, thereby increasing the yield of dimethyl ether significantly. | The present invention relates to a process for preparing dimethyl ether from methanol. More particularly, this invention relates to an improved process for preparing dimethyl ether with high yield useful as a clean fuel as well as a raw material in chemical industry performed via a catalytic system, wherein dehydration of methanol is first carried out by using a hydrophilic solid acid catalyst and then subsequent dehydration of methanol is carried out continuously by using a hydrophobic zeolite solid acid catalyst in the concurrent presence of unreacted methanol, dimethyl ether produced and water. | 2 |
FIELD OF THE INVENTION
[0001] The present invention relates to the field of building materials, more specifically, relates to a composition used for high-strength impermeable concrete.
BACKGROUND OF THE INVENTION
[0002] Concrete is one of the most important civil engineering materials today. It is characterized by abundant raw material, low price and simple production process as well as high compressive strength, high durability and a wide range of strength grades, so it is widely used in various civil works.
[0003] Ordinary concrete is an artificial stone material formed after hardening of the mixture of cement, sand, stone, admixture and water. Sand and stone play a role of framework in concrete and inhibit the contraction of cement. Cement and water form cement paste, which covers the surface of sand and stone and fill the gap between the sand and the stone. Before hardening, cement paste plays a lubricating role and makes concrete mixture have desirable workability. After hardening, it cements the aggregate which plays a role of framework to form a firm body. Ordinary concrete has certain workability, strength, deformation and durability.
[0004] However, in the recent years, following the development of the construction industry, the requirements on building materials are getting stricter, particularly on concrete which has the widest use among building materials. Ordinary concrete can no longer meet the requirements of modern buildings on strength and impermeability. Although many kinds of novel concrete keep emerging, their strength and impermeability are still low and need to be improved further.
SUMMARY OF THE INVENTION
[0005] In order to overcome the low strength and impermeability of the prior art, the object of the present invention is to provide a new-type composition used for concrete which has high strength and good impermeability.
[0006] The present invention provides a composition used for high-strength impermeable concrete, the composition contains sand, stone, cement, water reducer and water, wherein the composition also contains reinforced impermeable sand, which includes aeolian sand and binder covering the surface of the aeolian sand.
[0007] In the present invention, by adding reinforced impermeable sand obtained from aeolian sand with surface modified and covered with binder to a composition used for concrete which contains sand, stone, cement, water reducer and water, the gap between the sand and the stone can be filled in a desirable way and all components of the composition are effectively combined, and the seepage phenomenon of the molded concrete is suppressed, thereby greatly improving the strength and impermeability of concrete. For example, the effect of Examples 1-5 of the present invention indicates the concrete made from the composition used for high-strength impermeable concrete provided by the present invention can achieve 100 MPa of compressive strength and 13 MPa of breaking strength, and the impermeability grade may reach P38.
DETAILED DESCRIPTION OF THE EMBODIMENTS
[0008] The present invention provides a composition used for high-strength impermeable concrete, the composition contains sand, stone, cement, water reducer and water, wherein the composition also contains reinforced impermeable sand, which includes aeolian sand and binder covering the surface of the aeolian sand.
[0009] Preferably, on the basis of the total weight of the composition, the content of the reinforced impermeable sand may be 1-10 wt %. More preferably, on the basis of the total weight of the composition, the content of the sand may be 10-35 wt %, the content of the stone may be 20-60 wt %, the content of the cement may be 10-30 wt %, the content of the water reducer may be 0.05-1 wt % and the content of the water may be 10-15 wt %. Still more preferably, the content of the sand may be 15-30 wt %, the content of the stone may be 30-50 wt %, the content of the cement may be 15-25 wt %, the content of the water reducer may be 0.1-1 wt %, the content of the reinforced impermeable sand may be 2-8 wt % and the content of the water may be 11-14 wt %. When the content of every component of the composition used for high-strength impermeable concrete provided by the present invention is in the foregoing preferable range, it can be assured that the concrete will have more desirable workability, strength, deformation and durability.
[0010] In the composition used for high-strength impermeable concrete according to the present invention, the preferred aeolian sand is the aeolian sand naturally formed in the desert, and the reinforced impermeable sand may be obtained by washing with water, drying and calcining the aeolian sand and then covering it with binder. Preferably, before washing with water, aeolian sand with a particle size of 75-850 μm is selected with a sieve. Then the dirt in the aeolian sand is washed away with water. After dried at 80-150° C., the aeolian sand is transferred to a calcining furnace and calcined at 200-2000° C. for 2-5 h. After calcining, it is cooled to 80-400° C. at a cooling speed of 25-650° C./h. Then it is transferred to a sand mixer. Binder is added and mixed evenly to obtain reinforced impermeable sand covered with binder. Alternatively, after mixing evenly, a curing agent may be further added and stirred 5-15 min to obtain reinforced impermeable sand. The curing agent may be a conventional curing agent in the art, such as: A-stage phenolic resin, and so on. Relative to 100 parts by weight of binder, the preferred amount of the curing agent is 10-50 parts by weight. Calcining aeolian sand at 200-2000° C., on the one hand may remove the impurities on its surface and on the other hand during heating and calcining, phase transition happens to the quartz of aeolian sand (reversible transition from α to β at 573° C., irreversible transition from β to γ at 870° C.), so the strength of aeolian sand may be improved significantly.
[0011] In the composition used for high-strength impermeable concrete according to the present invention, the average particle size of the reinforced impermeable sand may be 45-850 μm, preferably 50-200 μm, more preferably 75 μm. The average particle size of the reinforced impermeable sand may be measured by various common particle size testers. For example, it may be measured by a particle size sieve (standard sieve). The average particle size in the foregoing range helps the reinforced impermeable sand fill the gap of concrete in a better way and makes the concrete more compact. The average particle strength of the reinforced impermeable sand may be 20-60N, preferably 30-50N. The average particle strength of the untreated sand as described in the present invention, such as: aeolian sand, is typically 15-30N. The average particle strength of the reinforced impermeable sand may be measured by the following method for example: randomly select 30 sand particles, use a microcomputer controlled electronic universal testing machine (CMT4204, Shenzhen Sans Material Test Instruments Co., Ltd.) to test the maximum pressure endurable to the sand particles and choose the average value as average particle strength. The particle strength in the foregoing range helps improve the strength of concrete. The sphericity of the reinforced impermeable sand may be 0.5-0.8, preferably 0.6-0.8. The sphericity of the reinforced impermeable sand may be measured in accordance with SY/T5108-2006 Performance Index and the Recommended Test Method of Fracturing Propping Agent and in comparison with the reference sphericity plates. The sphericity in the foregoing range helps reinforced impermeable sand move in the gap of concrete, thereby filling the gap of concrete in a more desirable manner and making the concrete more compact.
[0012] In the composition used for high-strength impermeable concrete according to the present invention, the binder may be any binder that can realize the object of the present invention. In order that reinforced impermeable sand plays a better binding role in the gap of concrete and the components of concrete are combined more compactly, preferably the binder may be epoxy resin or phenolic resin. The epoxy resin or phenolic resin may be common epoxy resin or phenolic resin, with a weight-average molecular weight of 300-10000 typically. More preferably, the binder is epoxy resin, with a weight-average molecular weight of 8000-10000, and an epoxy value of 0.4-0.6 eq/100 g. The epoxy resin may be epoxy resin E44 (epoxy value 0.41-0.47 eq/100 g), epoxy resin E51 (epoxy value 0.48-0.54 eq/100 g) or epoxy resin E42 (epoxy value 0.38-0.45) produced by Beijing Heli Chemical Co., Ltd. The phenolic resin may be 939P phenolic resin produced by Beijing Heli Chemical Co., Ltd. These resins may be used separately or used in a combined matter. On the basis of the weight of the aeolian sand, the content of the binder may be 0.5-3 wt %, preferably 0.5-1.5 wt %.
[0013] In the composition used for high-strength impermeable concrete according to the present invention, the water reducer may be a water reducer typically used in the art. In order to reduce water consumption during mixing and improve concrete strength, preferably the water reducer may be at least one of polycarboxylic acid, polyamide, melamine and naphthalene series high efficiency water reducer. The weight-average molecular weight of the polycarboxylic acid and polyamide may be 6000-45000.
[0014] In the composition used for high-strength impermeable concrete according to the present invention, other additives may be contained too, provided that the properties of the composition of the present invention are not affected. For example, it may contain at least one of dispersible rubber powder, silica fume, fly ash, mineral powder and kaolin. The addition of the additives may significantly improve the comprehensive technical performance of concrete, such as: binding strength, compressive strength and breaking strength. All the additives are available in the market. Dispersible rubber powder may be JGB-101 dispersible rubber powder. Silica fume, also known as silica powder. Its main composition is SiO 2 , it is a byproduct of the smelting of ferrosilicon alloy or industrial silicon, formed from the cold oxidation and cold dust collection of the silicon vapor discharged in form of smoke. The silica fume produced by Beijing Linggan Technology Development Co., Ltd. for example may be used. The fly ash may be the fly ash produced by Beijing Electric Power Fly Ash Industrial Corporation for example. The mineral powder may be the GH mineral powder produced by Beijing Linggan Technology Development Co., Ltd. The kaolin may be the calcined kaolin produced by Beijing Eastern Allhand Co., Ltd. From the perspective of guaranteeing the strength and impermeability of concrete, on the basis of the total weight of the composition, the content of the additives may be 0.5-35 wt %.
[0015] In the composition used for high-strength impermeable concrete according to the present invention, the sand may be the untreated natural sand conventional in this field, such as: river sand, sea sand or aeolian sand. They are all available in the market and may be freely selected according to the actual need.
[0016] The stone may be conventional stone in this field, with a typical particle size of 5-25 mm. They are available in the market
[0017] The cement may be conventional silicate cement in the field. Cement may be produced by a conventional method: limestone, clay and iron ore powder is ground and mixed in proportion to obtain raw meal. The raw meal is calcined (normally the temperature is about 1450° C.) to obtain a calcination product (clinker). Then the clinker and plaster are finely ground and mixed in proportion to obtain cement. The cement is available in the market.
[0018] The components of the foregoing composition used for high-strength impermeable concrete are mixed and stirred 1-5 min to obtain a composition used for high-strength impermeable concrete.
[0019] In respect to the preparation method of the foregoing composition used for high-strength impermeable concrete, there is no specific limitation to mixing and stirring methods. Various existing mixing and stirring methods may be adopted. For example, a common concrete mixer may be adopted for the stirring and mixing. Various types of concrete mixer may be used, such as: 55-C0199 concrete mixer produced by Beijing Newlead Science & Technology Co. Ltd.
[0020] Below the present invention is described in more details in connection with examples, but the present invention is not limited to these examples.
[0021] In the following examples and comparison examples, sand (river sand, sea sand or aeolian sand) is bought from Beijing Chaoyue Building Material Trading Co., Ltd.; stone are bought from Beijing Chaoyue Building Material Trading Co., Ltd., with a particle size of 2.5-20 mm; cement is bought from Beijing Cement Plant Co., Ltd.; water reducer is KSM-830 polycarboxylic acid high efficiency water reducer bought from Beijing Kaisimei United Chemical Products Co., Ltd.
[0022] Preparation process of reinforced impermeable sand
[0023] Aeolian sand is screened to obtain aeolian sand with a particle size of 45-850 μm. The dirt in it is washed away with water. Then it is dried at 120° C. and the average particle strength is measured. It is 20N. The foregoing dried aeolian sand is transferred to a calcining furnace and calcined at 1000° C. for 3 h. After calcining, the temperature is kept 3.5 h. Then it is transferred to a sand mixer and naturally cooled to 200° C. Binder is added and mixed evenly. A-stage phenolic resin (Shanghai Ousheng Chemical Co., Ltd., model 2127) accounting for 20 wt % of the binder is added. After 5-15 min's stirring, the reinforced impermeable sand covered with binder is obtained.
Example 1
[0024] This example is intended to explain the composition used for high-strength impermeable concrete provided by the present invention.
[0025] The amount of each component is: river sand 50 kg, stone 80 kg, cement 37 kg, reinforced impermeable sand 10 kg, water reducer 1 kg and water 22 kg.
[0026] The river sand, stone and cement are added to a concrete mixer (Beijing Newlead Science & Technology Co. Ltd.; model 55-C0199). The mixer is started to carry out dry mixing. After evenly mixing, the reinforced impermeable sand obtained with the foregoing method for preparing reinforced impermeable sand is added. The composition and properties of the reinforced impermeable sand are as shown in Table 1. Stirred continuously till it is evenly, water reducer and water are added. Stirred at 150 r/min for 3 min, obtaining the composition used for high-strength impermeable concrete.
Comparison Example 1
[0027] This comparison example is intended to explain the composition used for ordinary concrete in the prior art.
[0028] The amount of each component is: river sand 60 kg, stone 80 kg, cement 37 kg, water reducer 1 kg and water 22 kg.
[0029] The river sand, stone and cement are added to a concrete mixer (Beijing Newlead Science & Technology Co. Ltd.; model 55-C0199). The mixer is started to carry out dry mixing. After evenly mixing, water reducer and water are added, Stirred at 150 r/min for 3 min, obtaining the composition used for ordinary concrete.
Example 2
[0030] This example is intended to explain the composition used for high-strength impermeable concrete provided by the present invention.
[0031] The amount of each component is: river sand 20 kg, stone 78 kg, cement 60 kg, reinforced impermeable sand 20 kg, water reducer 2 kg and water 20 kg.
[0032] The river sand, stone and cement are added to a concrete mixer (Beijing Newlead Science & Technology Co. Ltd.; model 55-C0199). The mixer is started to carry out dry mixing. After evenly mixing, the reinforced impermeable sand obtained with the foregoing method for preparing reinforced impermeable sand is added. The composition and properties of the reinforced impermeable sand are as shown in Table 1. Stirred continuously till it is evenly, water reducer and water are added. Stirred at 150 r/min for 5 min, obtaining the composition used for high-strength impermeable concrete.
Example 3
[0033] This example is intended to explain the composition used for high-strength impermeable concrete provided by the present invention.
[0034] The amount of each component is: river sand 70 kg, stone 77.9 kg, cement 20 kg, reinforced impermeable sand 2 kg, water reducer 0.1 kg and water 30 kg.
[0035] The river sand, stone and cement are added to a concrete mixer (Beijing Newlead Science & Technology Co. Ltd.; model 55-C0199). The mixer is started to carry out dry mixing. After evenly mixing, the reinforced impermeable sand obtained with the foregoing method for preparing reinforced impermeable sand is added. The composition and properties of the reinforced impermeable sand are as shown in Table 1. Stirred continuously till it is evenly, water reducer and water are added. Stirred at 150 r/min for 1 min, obtaining the composition used for high-strength impermeable concrete.
Example 4
[0036] This example is intended to explain the composition used for high-strength impermeable concrete provided by the present invention.
[0037] The amount of each component is: river sand 50 kg, stone 80 kg, cement 37 kg, reinforced impermeable sand 10 kg, silica fume 1 kg, water reducer 1 kg and water 21 kg.
[0038] The river sand, stone and cement are added to a concrete mixer (Beijing Newlead Science & Technology Co. Ltd.; model 55-C0199). The mixer is started to carry out dry mixing. After evenly mixing, the reinforced impermeable sand obtained with the foregoing method for preparing reinforced impermeable sand as well as silica fume (purchased from Dalian Qiannian Mining Co., Ltd.) are added. The composition and properties of the reinforced impermeable sand are as shown in Table 1. Stirred continuously till it is evenly, water reducer and water are added. Stirred at 150 r/min for 3 min, obtaining the composition used for high-strength impermeable concrete
Example 5
[0039] This example is intended to explain the composition used for high-strength impermeable concrete provided by the present invention.
[0040] The amount of each component is: river sand 30 kg, stone 40 kg, cement 29 kg, reinforced impermeable sand 10 kg, kaolin 70 kg, water reducer 1 kg and water 20 kg.
[0041] The river sand, stone and cement are added to a concrete mixer (Beijing Newlead Science & Technology Co. Ltd.; model 55-C0199). The mixer is started to carry out dry mixing. After evenly mixing, the reinforced impermeable sand obtained with the foregoing method for preparing reinforced impermeable sand as well as kaolin (purchased from Beijing Lanning Co., Ltd.) are added. The composition and properties of the reinforced impermeable sand are as shown in Table 1. Stirred continuously till it is evenly, water reducer and water are added. Stirred at 150 r/min for 3 min, obtaining the composition used for high-strength impermeable concrete
[0000]
TABLE 1
Composition and properties of the reinforced impermeable sand
Example 1
Example 2
Example 3
Example 4
Example 5
Type of binder (epoxy resin model)
E-51
E-44
E-42
E-44
E-44
Binder/aeolian sand (weight ratio)
1:100
1.2:100
1.5:100
0.5:100
0.8:100
Properties of reinforced impermeable sand:
Average particle size (μm)
106
150
75
300
212
Average particle strength
40N
42N
50N
35N
55N
Sphericity
0.6
0.7
0.6
0.7
0.6
Performance Testing of Concrete
1. Testing of Compressive Strength and Breaking Strength of Concrete
[0042] The test is performed according to GB/T 50081-2002 Testing Methods for Mechanical Performance of Ordinary Concrete.
2. Concrete Impermeability Grade Test
[0043] The test is performed according to GBJ82-85 Testing Methods for Long Term Properties and Durability of Ordinary Concrete.
Examples 6-10
[0044] The composition used for concrete is obtained from Examples 1-5 and cured in a standard curing box for 28 days. The compressive strength, breaking strength and impermeability grade are measured by the foregoing concrete property test methods. The test result is as shown in Table 2.
Comparison Example 2
[0045] The composition used for concrete is obtained from Comparison example 1 and cured in a standard curing box for 28 days. The compressive strength, breaking strength and impermeability are measured by the foregoing concrete property test methods. The test result is as shown in Table 2.
[0000]
TABLE 2
Ex-
Com-
Ex-
Ex-
Ex-
Ex-
ample
parison
ample 6
ample 7
ample 8
ample 9
10
example 2
Compressive
80
71
100
98
75.6
38.4
strength
(MPa)
Breaking
10
8
13
11.5
9.2
5
strength
(MPa)
Imperme-
35
33
38
38
36
14
ability grade
[0046] The data in Table 2 indicate the compressive strength of high-strength impermeable concrete of the present invention is as high as 100 MPa, the breaking strength is as high as 13 MPa and the permeability grade may reach P38. Compared with the ordinary concrete in the prior art, it has higher strength and impermeability. | A composition used for high-strength impermeable concrete. The composition contains sand, stone, cement, water reducer, water and reinforced impermeable sand. The reinforced impermeable sand includes aeolian sand and binder covering the surface of the aeolian sand. The reinforced impermeable sand can fill the gap between the sand and the stone, and well combine various components in the composition, and suppress the seepage phenomenon of the molded concrete, thereby greatly improving the strength and impermeability of the concrete. | 8 |
FIELD OF THE INVENTION
[0001] The present invention pertains to the field of reconfigurable logic circuitry. More particularly, this invention relates to the design and use of reconfigurable logic circuitry, such as special purpose Field Programmable Gate Array (FPGA) for use in emulation of integrated circuit (IC) designs.
BACKGROUND OF THE INVENTION
[0002] With advances in integrated circuit technology, various technologies have been developed to aid circuit designers in designing and debugging highly complex integrated circuits. In particular, emulation systems comprising reconfigurable logic elements have been developed for circuit designers to “realize” their designs in hardware for more rapid verification of these designs.
[0003] The first generation of prior art emulation systems were typically formed using general purpose FPGAs. To emulate a circuit design on one of such emulation systems, the circuit design would be “realized” by compiling a formal description of the circuit design; partitioning the circuit design into subsets, mapping the various subsets to the reconfigurable logic resources of the FPGAs of various logic boards of the emulation system, and then configuring and interconnecting the reconfigurable logic resources. The partitioning and mapping operations would typically be performed on workstations that are part of, or complementary to, the emulation systems, while the configuration information would be correspondingly downloaded onto the logic boards hosting the FPGAs, and then onto the FPGAs.
[0004] With advances in integrated circuit and emulation technology, some late model emulation systems employ “FPGAs” specifically designed for emulation purposes. For example, during emulation, test stimuli are generated either on the workstation or on a service board of the emulation system under the control of the workstation. The test stimuli are transferred to the various logic boards for application to the realized circuitry of the IC design being emulated. Debugging information such as state data of various circuit elements, as well as signal states of interest of the IC design being emulated, would correspondingly be read out of the applicable FPGAs, and then transferred off the logic boards, for analysis on the workstation.
[0005] To support these debugging resources, as well as requirements for increased logic emulation capability in light of today's larger circuits, these special “FPGAs” or emulation ICs would typically include a substantial amount of on-chip reconfigurable logic elements, memory and debugging resources. Notwithstanding an increase of interconnects on the boards containing these emulation ICs, the dramatic increase in the number of resources in today's emulators results in a longer compile time to map an IC design to the reconfigurable emulation resources of an emulator. Thus, emulation resources with improved routability, and emulation systems using such improved routability emulation resources are desired.
BRIEF SUMMARY OF THE INVENTION
[0006] The present invention provides methods and apparatuses that support a reconfigurable logic element (RLE) architecture for use in an emulation system. The RLE has lookup table logic circuitry for implementing a function. In addition, the RLE contains multi-stage coupling logic circuitry correspondingly coupling RLE inputs to the inputs of the lookup table logic circuitry. The present invention allows global routing of the emulation system by circuit design mapping software to be much more flexible, as the routing may be configured independently of input constraints due to the ability to reassign the inputs with a multistage coupling network. With one exemplary embodiment of the invention, the multistage coupling network utilizes six two-signal switching circuits, while a variation of the exemplary embodiment utilizes five two-signal switching circuits.
BRIEF DESCRIPTION OF THE DRAWINGS
[0007] Illustrative embodiments of the present invention are illustrated by way of example in the accompanying drawings. The drawings are not, however, intended to limit the scope of the present invention. Similar references in the drawings indicate similar elements.
[0008] [0008]FIG. 1 illustrates the major functional blocks of an illustrative embodiment of a logic board in accordance with at least one aspect of the present invention;
[0009] [0009]FIG. 2 illustrates an illustrative embodiment of a hosted emulation IC of FIG. 1 in further detail, in accordance with at least one aspect of the present invention;
[0010] [0010]FIG. 3 illustrates a portion of an illustrative reconfigurable logic element (RLE);
[0011] [0011]FIG. 4 illustrates a portion of an illustrative embodiment of a reconfigurable logic element (RLE) including swapper logic in accordance with at least one aspect of the present invention;
[0012] [0012]FIG. 5 illustrates an emulation system as may be used in accordance with at least one aspect of the present invention;
[0013] [0013]FIG. 6 shows an illustrative embodiment of the swapper logic of FIG. 4;
[0014] [0014]FIG. 7 shows a table of illustrative input/output mappings;
[0015] [0015]FIG. 8 shows a table containing an illustrative configuration of a six configuration bit swapper;
[0016] [0016]FIG. 9 is a continuation of the table that is shown in FIG. 8;
[0017] [0017]FIG. 10 shows another illustrative embodiment of signal swapper logic of FIG. 4; and
[0018] [0018]FIG. 11 shows an illustrative emulation system that may be used with at least one aspect of the present invention.
DETAILED DESCRIPTION
[0019] The following disclosure describes a novel architecture for a reconfigurable logic element (RLE) providing for increased routability of input signals associated with the RLE. The phrase “reconfigurable logic element” is used throughout this invention description, and is not intended to be limited to any particular reprogrammable logic block but should be interpreted, with the exception of the novel features of the disclosed invention, as one of any number of types of reconfigurable logic resource elements.
[0020] Referring to FIG. 1, an illustrative logic board 100 may include on-board data processing resources 102 , on-board emulation ICs 104 , on-board reconfigurable interconnects 106 , board bus 108 , and on-board trace memory 110 coupled to each other as shown (e.g. through board bus 108 ). Additionally, on-board emulation ICs 104 may also directly coupled to on-board trace memory 110 . Logic board 100 may further include a plurality of I/O pins (not explicitly illustrated). A first subset of the I/O pins may be employed to couple selected ones of outputs of reconfigurable interconnects 106 to reconfigurable interconnects of other logic boards and ultimately to emulation resources 120 of the other logic boards (thereby coupling the emulation resources of the logic boards). A second subset of the I/O pins may be employed to couple data processing resources 102 to certain control resources, such as a control workstation 115 .
[0021] One or more emulation ICs 104 may be used to “realize” the netlists of a digital or an analog IC design to be emulated. The emulation ICs 104 may each include reconfigurable logic resources and reconfigurable interconnect resources. Together, these are referred as emulation resources. These reconfigurable logic resources may include reconfigurable logic elements (RLEs), which also may be referred as configurable logic blocks (CLBs). Reconfigurable interconnects 106 may facilitate coupling of the emulation resources of the various emulation ICs 104 of the different logic boards 100 (or with the same logic board) employed to form an emulation system. Board bus 108 and trace memory 110 may perform their conventional functions of facilitating on-board communication/data transfers, and collection of signal states of the various emulation signals of the assigned partition of the IC design being emulated.
[0022] Referring to FIG. 2, emulation IC 104 may include reconfigurable logic resources (RLR) 202 , reconfigurable interconnects (RIN) 204 , emulation memory (MEM) 206 , debugging resources (DBR) 208 , and/or configuration registers (CR) 212 and 214 coupled to each other as shown. Reconfigurable logic resources 202 and emulation memory 206 may be used to “realize” circuit elements of a design (or a partition thereof) to be emulated. Reconfigurable interconnects 204 may be used to reconfigurably couple reconfigurable logic resources 202 , memory 206 , and/or other resources.
[0023] [0023]FIG. 3 illustrates an illustrative reconfigurable logic element (RLE), such as may be part of the reconfigurable logic resources 202 . As shown, RLE 300 includes a multiple input-single output truth table 302 , a pair of master-slave latches 306 - 308 , control logic 310 , and a plurality of input and output multiplexors coupled to each other as shown. Truth table 302 is used to reconfigurably generate an output in response to a provided set of inputs to the truth table. For the illustrated embodiment, truth table 302 has four inputs, 10 - 13 , and a single output. However, any number of inputs and outputs may be used. Thus, truth table 302 may be programmed to realize any one of a plurality of different Boolean functions. As shown in the drawing, the inputs 10 - 13 to truth table 302 may also be used as control signals, such as set, reset, enable and/or clock, for master-slave latches 306 , 308 . Thus, input functions for I 0 -I 3 may be fixed to the inputs of the RLEs.
[0024] A swapper 320 , as shown in FIG. 4, may be disposed between the inputs to the RLE 300 and the inputs of truth table 302 . Swapper 320 may provide a translation between inputs and outputs. However, other embodiments of the invention may utilize other types of logic entities to provide a corresponding switching functionality such as a switch matrix, crossbar switch, and/or multiplexer configuration. In one embodiment, swapper 320 includes configurable logic and/or circuitry that “bijectively” maps RLE inputs I 0 -I 3 312 - 318 to truth table input and clock control signals I 0 ′-I 3 ′ 322 - 328 . A mapping is bijective if the mapping is one-to-one mapping and onto. In other words, for a mapping to be bijective, an input maps to only one output but not to a plurality of outputs. For example, the swapper 320 maps RLE input I 0 312 to any of the swapper's 320 outputs, I 0 ′-I 3 ′ 322 - 328 . Similarly, the remaining inputs I 1 -I 3 314 - 318 may also be routed to any of outputs 10 ′- 13 ′ 322 - 328 except for the output to which I 0 312 was routed. Other embodiments of the invention may support other types of mapping, e.g., mapping an input to a plurality of outputs. In another embodiment, swapper 320 includes reconfigurable logic and/or circuitry to dynamically reconfigure the mapping between I 0 -I 3 312 - 318 and I 0 ′-I 3 ′ 322 - 328 . In another embodiment, the swapper 320 is reconfigurable independent from other configurable logic in the RLE, such as the truth table 302 .
[0025] In comparison with other switching configurations, such as crossbar switch, the swapper 320 may utilize less electrical power and may require less circuit complexity because an input to the swapper 320 does not map to a plurality of outputs, as may be the case with other switching configurations. Moreover, the swapper 320 may facilitate configuring the emulation board 100 because the swapper 320 provides an additional degree of freedom for switching logic signals with the emulation board 100 .
[0026] A swapper (as illustrated in FIGS. 6 and 10) may be used to support functionality (that is not limited to a RLE, e.g. RLE 300 ) in an emulation system. In an embodiment of the invention, a swapper may be incorporated in the reconfigurable interconnects 106 . The reconfigurable interconnects 106 may be implemented with at least one swapper and may also include other switching configurations, e.g. a crossbar switch, with the at least one swapper.
[0027] The inputs to the RLE may be completely undifferentiated. Thus, for instance, any one of the inputs may couple, in addition to any of the inputs of the truth table logic 302 , to any of the control signals feeding the control logic 310 of the sequential elements 306 , 308 .
[0028] [0028]FIG. 5 shows an illustrative embodiment of an emulation system including an emulator 506 and a control workstation 502 . In the embodiment shown, control workstation 502 contains design routing software 504 . One of the functions of design routing software 504 is to “compile” a design to be emulated. Such a compilation may involve partitioning the design among the various reconfigurable logic resources of the emulator as well as routing signals that are required to connect these resources. As will be appreciated by one skilled in the art of placement and routing of designs, as design size increases, and correspondingly the utilization of reconfigurable logic resources on emulation ICs 104 , the design routing software 504 will have a more difficult time performing the routing for a given placement of design elements in the reconfigurable logic resources on-board the emulation ICs 104 . As the reconfigurable logic resources fill, routing time becomes exponentially longer. Even more problematic, as resources become very highly utilized, the routing software, at times, will not be able to perform the routing for a given placement. This inability to route results in the design routing software 504 having to reassign the design in the reconfigurable logic resources and perform another routing of the design. By adding a swapper (such as swapper 320 ) to the input of some or all of the RLEs, an additional resource may be provided to the design routing software 504 to enable it to globally route designs that would otherwise not be routable or, in the cases where designs are routable, to route those designs more quickly. This added routing ability is facilitated by the fact that, as previously discussed, some, if not all, of the inputs to the RLE may now be completely undifferentiated. In one embodiment of the present invention, the swapper logic may be reconfigured independently from other elements in the design, even on a RLE-by-RLE basis. A potential advantage of this embodiment is the ability to perform minor design tweaks in a design and have the design routing software 504 provide very quick design rerouting as a result of the ability to simply change the configuration in a single RLE or small number of RLEs.
[0029] [0029]FIG. 6 illustrates one embodiment of the swapper 320 , in which the swapper 320 is an optimized matrix with reduced configurations points to create a one to one correspondence of four inputs to four outputs in a RLE used for emulation. In this embodiment, the logic circuitry 600 is a three-stage network of two-signal switching circuits 602 - 612 that, together, are capable of swapping four inputs, as discussed above, to four outputs. The six two-signal switching circuits 602 - 612 are each controlled by a configuration bit 622 - 632 . Each configuration bit informs the appropriate two-signal switching circuit as to whether each input to the two-signal switching circuit should be passed through or switched. For example, in one embodiment, where configuration bit 622 is set to zero, two-signal switching circuit 602 is commanded to pass outputs directly through. As a result, output 642 of circuit 602 would be driven by input IA and output 644 would be driven by input IB. Conversely, where configuration bit 622 is set to one, the outputs 642 , 644 are consequently swapped. In other words, input IA would drive output 644 while input 1 B would drive output 642 . Of course, the configuration bit may operate in an opposite manner as described above, i.e., a configuration bit set to zero is a command to switch and a configuration bit set to one is a command to pass.
[0030] The three stage network embodiment discussed above potentially provides an advantage over a standard crossbar interconnect for a four input to four output mapping. In such a traditional mapping, sixteen configuration bits would be required to configure the interconnect points of a four-to-four mapping. The above-described embodiment however, uses a scant six configuration bits and thus a savings of ten bits per RLE. Given that the current generation of emulation ICs have on the order of 1,000 RLEs on a device, a savings of on the order of 10,000 configuration bits per device may result. Moreover, with each emulation board 100 having upwards of forty-four emulation ICs 104 , this may result in the savings of a half million configuration bits per emulation board in an emulation system. Consequently, the savings during the configuration and reconfiguration of the emulation system can be significant.
[0031] Although swapper 320 supports four inputs and four outputs as shown in FIG. 4, FIG. 6, and FIG. 10, swapper 320 may support a different number of inputs and outputs, which may be generalized to N inputs and M outputs, where N and M may be the same or different. A swapper may comprise an input interface, an output interface, and a switching module. The input interface accommodates the N inputs by providing mechanical and/or electrical connectivity for the N inputs. The output interface accommodates the M outputs by providing mechanical and/or electrical connectivity for the M outputs. A switching module, which couples to the input interface and to the output interface, bijectively maps the N inputs to the M outputs. Where there are a greater number of inputs than outputs, then it may be decided that some of the inputs may not be used. Similarly, where there are a greater number of outputs than inputs, then some of the outputs may not be used. For example, where N=4 and M=6, then two of the outputs could be left unused (e.g., not mapped to an input) or even tied to other of the outputs. Thus, the swapper in such an example may be considered to have four inputs and four outputs, as well as two extra unused outputs.
[0032] [0032]FIG. 7 shows input to output pattern mappings and a mapping assignment in accordance with one embodiment. Note that with a four input and four output swapper there are a total of 24 (24=4×3×2×1=4!) different combinations of input to output mappings. As noted in the discussion associated with FIG. 6, there are six configuration bits 622 - 632 . FIGS. 8 and 9 together illustrate a truth table showing the different configurations bits possible (2 6 =64) and the corresponding input to output pattern mappings for this embodiment. The truth table indicates that there are a significant number of repeated pattern numbers 810 over all values of the configuration bits. (A pattern number is associated with a unique input-to-output mapping for swapper 320 . For example, pattern number 7 corresponds to a mapping IB to OA, IA to OB, IC to OC, and ID to OD.)
[0033] Referring to the embodiment as shown in FIG. 6, a “0” configuration bit for a two-signal switching circuit results in a non-swap of the two inputs, whereas a “1” configuration bit induces a swap. Reviewing the table entries for input/output pattern combinations in FIG. 8, while holding SW 11 at a “0”, one notes that all possible input/output pattern combinations occur (bolded-italicized rows). Since the case of holding SW 11 at a “0” is the same as logically replacing SW 11 with wires, it is possible to perform all input/output mappings with only five two-signal switching circuits as shown in FIG. 10. Further analysis of Tables 8 and 9 indicates that it is possible to remove any one of the six swappers and perform the complete input/output mapping. Empirical analysis can be verified with a more formal approach. There are 2 6 (64) possible configuration combinations, utilizing 6 configuration bits. However, there are only twenty-four combinations required to perform all input/output pattern mappings. Since five configuration bits provide for 2 5 (32) combinations, it follows that, while an embodiment uses six configuration bits, it is possible to provide for the twenty-four different input/output pattern mappings with five configuration bits with a variation of the embodiment.
[0034] [0034]FIG. 11 shows a block diagram of an emulation system formed using logic boards 100 . As illustrated, emulation system 1100 includes control workstation 1102 and emulator 1106 . Control workstation 1102 is equipped with design routing software 1104 . Emulator 1106 includes a number of logic boards 100 , each having a number of emulation ICs 104 , trace facilities (not shown) and reconfigurable interconnects 1110 disposed thereon. In addition to logic boards 100 , emulator 1106 also includes service and I/O boards 1108 . Boards 100 and 1108 are interconnected by inter-board interconnects 1110 . In one embodiment, various boards 100 and 1108 are packaged together to form a “crate” (not shown), and the crates are interconnected together via inter-board interconnects 1110 . The precise numbers of emulation ICs 104 disposed on each board, as well as the precise manner in which the various boards are packaged into crates, are not limited by the present invention and are application dependent. Design routing software 1104 may require modification for support of the swapping configuration logic in the RLEs as described herein. However, design routing software 1104 is otherwise intended to represent a broad range of the software typically supplied with an emulation system. Additionally, emulator 1106 is intended to represent a broad range of emulators known in the art.
[0035] Thus, a RLE equipped with an input line swapper, as well as an improved IC, logic board, and emulation system, along with methods associated therewith, have been described herein. While the apparatuses and methods of the present invention have been described in terms of the above illustrated embodiments, those skilled in the art will recognize that the various aspects of the present invention are not limited to the embodiments described. The present invention can be practiced with modification and alteration within the spirit and scope of the appended claims. The description is thus to be regarded as illustrative rather than restrictive of the present invention. | A novel reconfigurable logic element (RLE) architecture for use in an integrated circuit itself used in an emulation system is disclosed. The RLE has lookup table logic circuitry for implementing a function. In addition, the RLE contains multi-stage coupling logic circuitry correspondingly coupling RLE inputs to the inputs of the lookup table logic circuitry. This allows global routing of the emulation system by circuit design mapping software to be much more flexible, as the routing may be configured independently of those four input constraints due to the ability to reassign the inputs with the swapper. | 7 |
CROSS-REFERENCE TO RELATED APPLICATIONS
This application is a U.S. National-Stage entry under 35 U.S.C. §371 based on International Application No. PCT/EP2010/000452, filed Jan. 27, 2010, which was published under PCT Article 21(2) and which claims priority to German Application No. 102009017385.4, filed Apr. 14, 2009, which are all hereby incorporated in their entirety by reference.
TECHNICAL FIELD
The technical field relates to a composite pane arrangement, in particular for motor vehicles, with a composite pane and with at least one optical sensor device to detect moisture on an outer surface of the composite pane.
BACKGROUND
Modern motor vehicles are frequently equipped with an optical sensor device to detect moisture on an outer surface of the glass windshield, which is coupled with a control device for controlling a windshield wiper system of the glass windshield so that the wiping processes are able to be controlled automatically as a function of the degree of wetting of the glass windshield. Such optical sensor devices—generally designated as “rain sensors”—are used in practice in numerous variants and have already been described in many cases in the patent literature. They are based on the fundamental principle that the glass windshield serves as an optical waveguide. The light generated from an optical transmitter is coupled in on the inner side of the pane facing the passenger compartment and after total reflection on the outer side of the pane, facing away from the passenger compartment, is coupled out on the inner side of the pane and is picked up by an optical receiver. Depending on the degree of wetting of the outer surface of the glass windshield, which involves a change to the refractive index for the pane/air transition of the outer side of the pane, the proportion of the reflected light varies, so that indirectly a conclusion can be drawn as to the quantity of fluid or respectively the degree of wetting on the outer surface of the glass windshield.
On the one hand, rain sensors must be arranged in the wiping field of the glass windshield, but on the other hand they must at least not substantially impair the clear visibility for the driver. Usually, rain sensors are mounted for this purpose in the region of the interior rear-view mirror on the inner side of the glass windshield. In addition, in this case, the portion of the electric leads situated in the region of the glass windshield for supplying the rain sensor with electric power and for signal transmission to the control arrangement of the windshield wiper system can be kept relatively short.
In motor vehicles with composite panes, which typically have an outer and inner pane with an intermediate layer of, for example, polymer material, the light is coupled in on the inner side of the composite pane facing the passenger compartment, passes through the intermediate layer, and after total reflection on the outer side of the outer pane is coupled out again on the inner side of the composite pane.
In contrast, at least one object is to provide an improved composite pane arrangement. In addition, other objects, desirable features and characteristics will become apparent from the subsequent summary and detailed description, and the appended claims, taken in conjunction with the accompanying drawings and this background.
SUMMARY
A composite pane arrangement, in particular for motor vehicles, is shown. The composite pane arrangement comprises a composite pane which consists of at least two for example glass panes, which are connected with each other by an intermediate layer consisting for example of polymer material. In a motor vehicle, these are an inner pane arranged on the passenger compartment side and an outer pane, delimiting the composite pane towards the environment, which are connected to the composite pane via the intermediate layer. It further comprises at least one optical sensor device for the optical detection of moisture on an outer surface of the composite pane facing away from the intermediate layer. It is essential here that the optical sensor device is arranged between the two panes and is contacted electrically by means of transparent, laminar conductive traces. The optical sensor device comprises for this purpose an optical transmitter for the generation of light, and if applicable a light coupling-in element associated with the transmitter, through which the generated light can be coupled in in a suitable manner directly into the pane of which the wetting is to be detected. It further comprises an optical receiver for the detection of radiation reflected on the outer surface of the composite pane, and if applicable a light coupling-out element associated with the receiver, through which the generated light can be coupled out in a suitable manner from the pane of which the wetting is to be detected. Furthermore, the optical sensor device typically comprises an evaluation unit for the evaluation of electronic signals of the optical detector, the output signals of which, for example in a motor vehicle, can be fed to a control arrangement for controlling the windshield wiper system of a glass windshield. The evaluation unit can be integrated in particular into such a control arrangement.
The transparent, laminar conductive traces have an electrically conductive material, such as for example a thin layer of a metallic material vapor-deposited onto the intermediate layer, or a polymer material which is made to be conductive by the addition of a metallic material. In particular here, this can be a transparent, conductive oxide on the basis of oxidic semiconductors with a low specific resistance, for example indium tin oxide (In 2 O 3 :SnO 2 ), aluminum tin oxide (ZnO:Al) and fluorine tin oxide (SnO 2 :F).
In terms of this description, the expression “light” comprises electromagnetic radiation which can also lie outside the visible wavelength range.
By the composite pane arrangement, it can be achieved in an advantageous manner that light is coupled in directly into the pane on the other surface of which the wetting is to be detected. In the motor vehicle, this is the outer surface of the composite pane. In an advantageous manner, it can hereby be avoided that the light passes through the other pane (inner pane in the motor vehicle) of the composite pane and the intermediate layer, so that the measurement accuracy owing to unavoidable optical non-homogeneities and random imperfections can be improved. In a particularly advantageous manner, the clear visibility for the driver is not impaired due to the transparent, laminar conductive traces for the electrical contacting of the optical sensor device. It is therefore possible to guide the transparent conductive traces in any desired manner onto one or several edges of the composite pane.
In an embodiment of the composite pane arrangement, the optical sensor device is arranged in a recess or respectively depression of the intermediate layer which is open towards the outer surface of the composite pane. Through this step, the composite pane arrangement can be produced in a particularly simple manner, without substantially impairing the structure of the composite pane.
In a further embodiment of the composite pane arrangement, the transparent, laminar conductive traces for the contacting of the optical sensor device are applied on a surface of the intermediate layer, which makes possible a particularly simple producability of the conductive traces. Thus, the conductive traces can be produced for example by laminar coating of the intermediate layer with conductive material, for example by vapor deposition and subsequent forming of the conductive traces by selective removal of conductive material. The transparent conductive traces can be formed in particular on the surface of the intermediate layer which faces the outer surface of the composite pane, the wetting of which is to be detected. This facilitates the electrical contacting of the optical sensor device, because the transparent conductive traces can be guided in a simple manner up to the optical sensor device. However, it is also equally possible that the transparent conductive traces are formed on the surface of the intermediate layer which faces away from the outer surface of the composite pane, the wetting of which is to be detected. In this case, the optical sensor device can be connected electrically via electric bridges, for example contact pins, within the intermediate layer with the transparent conductive traces. It would also be conceivable to provide the intermediate layer for example with through-openings, which are filled with a transparent electrical material.
In a further embodiment of the composite pane arrangement, the above-mentioned evaluation unit for the evaluation of electronic signals of the optical receiver is arranged outside the composite pane. Through this step, the part of the optical sensor device, arranged in the region of the composite pane, consisting substantially of the optical transmitter and optical receiver, is configured so as to be relatively small in its dimensions. In particular in this case, the optical sensor device can also be placed in the field of vision of the driver of a motor vehicle, without substantially impairing the visibility.
According to a further embodiment of the composite pane arrangement in a motor vehicle, it can be advantageous if the optical sensor device is arranged in the vicinity of an interior rear-view mirror of the motor vehicle. In particular in this case, it can be advantageous furthermore if the transparent conductive traces are guided to the lateral edges and/or to an upper edge and/or to a lower edge of the composite pane, whereby electrical conductive connections between the optical sensor device and a voltage source (car battery, for example) for the supply of the sensor device with electrical power and/or of the evaluation unit for the evaluation of electrical signals of the optical receiver can be kept short, in order to save material and costs in an advantageous manner in industrial mass production.
According to a further embodiment of the composite pane arrangement, the composite pane extends in the form of a so-called “panoramic pane” up to a roof crossmember connecting the two opposite B-columns of a vehicle body with each other. In this case, a non-visible, electrical contacting of the optical sensor device through the transparent, laminar conductive traces is particularly advantageous.
A motor vehicle is also provided that is equipped with at least one composite pane arrangement as described above.
BRIEF DESCRIPTION OF THE DRAWINGS
The present invention will hereinafter be described in conjunction with the following drawing figures, wherein like numerals denote like elements, and:
FIG. 1 is a diagrammatic sectional view in the longitudinal direction of the vehicle of a composite pane arrangement of a motor vehicle according to an embodiment;
FIG. 2 is a detail view of the composite pane arrangement of FIG. 1 ;
FIGS. 3A-3D are diagrammatic perspective views of the composite pane of the composite pane arrangement of FIG. 1 to illustrate different example variants of the transparent conductive traces for the contacting of the optical sensor device.
DETAILED DESCRIPTION
The following detailed description is merely exemplary in nature and is not intended to limit application and uses. Furthermore, there is no intention to be bound by any theory presented in the preceding background or summary or the following detailed description.
In FIG. 1 a composite pane arrangement of a motor vehicle is illustrated, designated as a whole by the reference number 1 , in a diagrammatic overview representation. Accordingly, the composite pane arrangement 1 comprises a frontal composite pane 2 , serving as a windshield, which extends from a frontal body section 9 up to a roof crossmember 6 connecting the two B-columns 5 of the body with each other. The two B-columns 5 constitute, as usual, a bearing connection between the vehicle floor and the vehicle roof in the region of the middle of the passenger compartment. In this respect, the composite pane 2 can be divided into a front section 3 extending obliquely to the horizontal or respectively the roadway, and a roof section 4 extending at least approximately parallel to the horizontal or respectively the roadway. In the region of an interior rear-view mirror 8 of the motor vehicle, the composite pane arrangement 1 comprises an optical sensor for the detection of the wetting of the outer surface 10 of the composite pane 2 , designated below as rain sensor 7 .
In FIG. 2 the structure of the composite pane 2 is illustrated in further detail. Accordingly, the composite pane 2 comprises two glass panes, namely an outer pane 11 and an inner pane 12 , by which a passenger compartment 18 of the motor vehicle is separated from the external environment. The outer and inner panes 11 , 12 are connected with each other by an intermediate layer 13 of adhesive polymer material. The rain sensor 7 is arranged in the region between the outer and inner panes 11 , 12 of the composite pane 2 , wherein the rain sensor 7 is held in a recess 19 of the intermediate layer 13 opening towards the outer pane 11 . The recess 19 is formed as a depression of a first surface 20 of the intermediate layer 13 facing the outer pane 11 . On a second surface 21 of the intermediate layer 13 , facing the inner pane 12 , a plurality of optically transparent, laminar conductive traces 14 of an electrically conductive material are formed. An electrical connection between the rain sensor 7 and the transparent conductive traces 14 takes place through the electrical contact pins 15 . Alternatively, the transparent, laminar conductive traces 14 could be formed on the first surface 20 of the intermediate layer 13 , which makes the contact pins 15 dispensable.
The rain sensor 7 serves for the detection of a wetting of the outer surface 10 of the outer pane 11 of the composite pane 2 with fluid. For this purpose, the rain sensor 7 comprises an optical sensor 22 for the generation of light, which is coupled in directly into the outer pane 11 as an incident light beam 16 via a light coupling-in element which is not illustrated. An incident angle of the incident light beam 16 is selected here so that that light beam 16 is totally reflected on the outer surface 10 of the outer pane 11 . The intensity of the reflected light beam 17 depends here on the wetting of the outer surface 10 of the outer pane 11 . Via a light coupling-out element which is not illustrated in further detail, the reflected light beam 17 is detected by an optical receiver 23 of the rain sensor 7 , which generates an electrical signal based on the received light intensity. The structure and the mode of operation of the components of such a rain sensor 7 , including the light coupling-in and light coupling-out elements, are known per se to the specialist in the art, so that it is unnecessary to enter into this in further detail here.
The rain sensor 7 is connected via the transparent, laminar conductive traces 14 with a diagrammatically illustrated evaluation unit 25 for the evaluation of the electrical signals of the optical receiver, wherein the evaluation unit 25 is integrated into a diagrammatically illustrated control device 24 for the automatic control of a windshield wiper system, not illustrated in further detail, for the wiping of the composite pane 2 . The control device 24 and hence the evaluation unit 25 is situated outside the composite pane 2 .
The transparent, laminar conductive traces 14 consist of a transparent, conductive oxide on the basis of an oxidic semiconductor with a low specific resistance, for example indium tin oxide (In 2 O 3 :SnO 2 ). They are produced by vapor deposition of an oxide layer onto the second surface 21 of the intermediate layer 13 and subsequent selective removal of layer sections. Over the width of the laminar conductive traces 14 , their electrical resistance can be set systematically. It would also be conceivable, as an alternative, to mask the second surface 21 of the intermediate layer 13 , wherein the mask is left free in accordance with the desired conductive traces 14 , followed by a vapor deposition of an oxide layer onto the masked second surface 21 .
In FIGS. 3A-3D , different example variants are illustrated for the course of the transparent, laminar conductive traces 14 . In FIG. 3A , the transparent conductive traces 14 extend in the transverse direction of the vehicle to the two lateral edges 26 of the composite pane 2 . In FIG. 3B , the transparent conductive traces 14 extend in the longitudinal direction of the vehicle to an upper edge 28 of the composite pane 2 arranged on the roof crossmember 6 . In FIG. 3C , the transparent conductive traces 14 extend both in the transverse direction of the vehicle to the two lateral edges 26 and also in the longitudinal direction of the vehicle to a lower edge 27 of the composite pane 2 arranged on the frontal body section 9 . In FIG. 3D , the transparent conductive traces 14 extend both in the transverse direction of the vehicle to the two lateral edges 26 and also obliquely to the longitudinal direction of the vehicle to the upper edge 28 of the composite pane 2 .
As was already explained in connection with FIG. 2 , the transparent conductive traces 14 serve for an electrical connection of the rain sensor 7 with the control device 24 for the transmission of the electrical signals for the automatic control of the windshield wiper system as a function of the degree of wetting of the outer surface 10 of the composite pane 2 . The transparent conductive traces 14 serve furthermore for an electrical connection with a vehicle battery (not illustrated) for the supply of the rain sensor 7 with electrical power. As illustrated in connection with FIGS. 3A-3D , the respective course of the transparent conductive traces 14 can be adapted systematically to the position of the control device 24 or respectively vehicle battery, in order to keep the electrical connections as short as possible.
In the composite pane arrangement 1 according to the invention, the incident light beam 16 for detecting the wetting of the outer surface 10 of the outer pane 11 is coupled in directly into the outer pane 11 , so that optical inhomogeneities of the inner pane 10 or respectively intermediate layer 13 cannot have an effect. The rain sensor 7 can be configured to be comparatively small, because the evaluation unit 25 is arranged outside the composite pane 2 . By a course of the transparent conductive traces 14 which is able to be designed with a free choice, with said traces not impairing the clear visibility for the driver, short electrical connections can be realized between the rain sensor 7 and the evaluation unit 25 or respectively the vehicle battery.
While at least one exemplary embodiment has been presented in the foregoing summary and detailed description, it should be appreciated that a vast number of variations exist. It should also be appreciated that the exemplary embodiment or exemplary embodiments are only examples, and are not intended to limit the scope, applicability, or configuration in any way. Rather, the foregoing summary and detailed description will provide those skilled in the art with a convenient road map for implementing an exemplary embodiment, it being understood that various changes may be made in the function and arrangement of elements described in an exemplary embodiment without departing from the scope as set forth in the appended claims and their legal equivalents. | A composite pane arrangement, in particular for a motor vehicle, is provided with a composite pane that includes, but is not limited to at least two panes connected with each other by an intermediate layer, and with at least one optical sensor device for the optical detection of moisture on an outer surface of the composite pane facing away from the intermediate layer. The optical sensor device is arranged between the two panes and is electrically contacted by means of transparent, laminar conductive traces. | 1 |
BACKGROUND OF THE INVENTION
The present invention relates generally to a mat cutter for cutting openings in picture mats used to frame pictures. More specifically, the present invention relates to a reversible mat cutter suitable for cutting oversized mats.
Picture mats are formed of a heavy card stock. A mat cutter has a cutter head mounted on a hinged frame which cuts internal openings in a picture mat within which a picture is framed. Typically, the cutter head is mounted on a rod supported by the hinged frame. The rod serves to guide the cutter head across the picture mat to be cut. Since, in the usual case, the opening for the framed picture will be defined by beveled edges, the cutter heads have often been provided with two blades, one blade to cut through the picture mat vertically, at a 90 degree angle, and another blade to cut at an acute angle (typically about 55 degrees) to produce a beveled opening. Picture mats are typically cut from the back, the blade being angled such that the border of the picture mat is located on the side of the guide rod opposite where the hinged frame is attached.
In most of the prior art, the angled blade is positioned on the side of the guiding rod away from the edge of the base where the hinged frame is attached. Thus, the picture mat is inserted from the edge where the hinged frame is attached and between the hinges. Therefore, a picture mat larger than the distance between the hinges cannot be cut. Furthermore, many prior art mat cutters utilize a guide rod mounted on a flat mat bar. This mat bar has one beveled edge to guide the angled blade, and one straight edge for the vertical blade.
FIG. 1 is a representative example of a prior art mat cutter 110. A hinged frame 114 attaches to the base 112 at a pair of hinges 116. The frame carries a mat bar 122, upon the top surface is mounted a guide bar 124. Both the mat bar 122 and the guide bar 124 are securely fastened to the tame 114. A cutter head 130 slides along the guide bar 124. A squaring arm 152 is mounted on the base 112, and a mat guide 142l is attached to the squaring arm 152. The cutter head 130 has an angled blade 132 for cutting a beveled edge, and a straight blade 134. The mat bar has a tapered edge 126 for guiding the angled blade, and a straight edge 127 for guiding the straight blade.
U.S. Pat. No. 3,996,827 (Logan) discloses a mat cutter in which the angled blade is mounted on the guide rod on the side away from the hinge attachment. The cutter head is not designed to be removable nor is the guide rod able to be easily detachable from the hinged frame. In U.S. Pat. No. 4,413,542 (Rempel) the mat cutter disclosed also shows an angled blade mounted on a fixed guide rod on the side away from the hinges. The mat guide for positioning a mat is only mountable on this side as well. The squaring arm is also only mountable on one side of the guide rod and is not quickly and easily detachable. U.S. Pat. Nos. 4,747,330 (Carithers, Jr.) and 4,871,156 (Kozyrski et al.) both disclose similar arrangements in which a mat cutter is designed to only receive a picture mat from one side.
The disadvantage of the prior art is that although a normal size picture mat can be inserted between the hinges to have an opening cut in its interior with beveled edges, an oversized picture mat (whose length is greater than the distance between the hinges) will not fit. Nor can an oversized picture mat be inserted from the side opposite the hinges because then the angled blade (which is fixed on one side) will cut a reverse bevel. Also, a problem is encountered if an oversized picture mat is inserted from the side opposite the hinges because the distance between a blade and the hinges is typically around four inches. Thus, a border of only four inches can be cut and an oversized mat often requires a larger border.
U.S. Pat. No. 3,213,736 (Keeton) discloses a mat cutter in which the angled blade is positioned on the same side of the guide rod as the hinges. However, neither the guide rod nor the mat bar is easily detachable from the hinged frame. The cutter head is also not reversible so that the angled blade could cut on the other side of the guide rod. The mat cutter in Keeton also has a relatively small distance between the angled blade and the mat guide or the hinges, allowing only a smaller border to be cut for a picture mat.
Considering the above disadvantages of the prior mat cutters, a reversible mat cutter that is well suited for cutting oversized mats would be desirable.
SUMMARY OF THE INVENTION
To achieve the foregoing and other objects and in accordance with the purpose of the present invention, a reversible mat cutter for the cutting of oversized picture mats is disclosed. A substantially flat base is used to support a picture mat to be cut and to support a clamp frame that is pivotally attached to the base at one edge of the base. A linear guide assembly which serves to press the picture mat toward the base stretches longitudinally across the base and is attached at either end to the clamp frame. The guide assembly also guides the cutter head as it cuts the picture mat on a first side of the guide assembly.
The guide assembly is attached to the clamp frame in a manner that allows one end of the guide assembly to be quickly and easily removed from the clamp frame. Once free, the cutter head can be removed from the guide assembly, reversed and slid back onto the guide assembly so that the angled blade cuts on a second side of the guide assembly.
In one embodiment the guide assembly includes two parts, a flat-bottomed mat bar and a cutter head guide rod. The flat-bottomed mat bar presses the picture mat toward the base, and the cutter head guide rod is mounted on top of the mat bar. The cutter head slides along the guide rod as it cuts the picture mat. The cutter head may have only an angled blade on the first side, or it may have the angled blade and also a straight blade on the second side of the mat bar. Each edge of the mat bar is tapered in a latitudinal direction so as to guide the angled blade as it cuts a bevel in a picture mat. The base may have a cutting groove extending longitudinally on each side of the mat bar directly below a cutting blade. As the blade cuts through the picture mat the tip of the blade extends into the cutting groove so as to not contact the surface of the base.
In another embodiment a mat guide that is attachable on either side of the mat bar is provided to help position the picture mat. The mat guide runs longitudinally along the base and is adjustable to vary the distance between the edge of the mat guide and a cutting blade. In this manner, a border width for a picture mat can be varied. A mat guide mount is located on each side of the mat bar so that the mat guide can be mounted on either side. The mat guide mount may be recessed so that when the mat guide is removed a picture mat may lie flat on the base.
In another embodiment a squaring arm is also mounted on the base. The squaring arm runs latitudinally and is perpendicular to the mat guide. It can be mounted on either side of the mat bar. The squaring arm serves to help square the picture mat. Like the mat guide, the squaring arm is also quickly and easily detachable from the base.
In one arrangement of the mat cutter that is particularly well suited for cutting an oversized picture mat, the cutter head is reversed so that the angled blade cuts on the second side of the mat bar adjacent to the edge where the clamp frame is pivotally attached. The mat guide is mounted on this second side as well, and if a squaring arm is to be used, it too is mounted on this second side. The distance between the mat bar and the pivotal attachment is extended relative to standard mat cutters so a larger border can be cut on an oversized mat. The mat cutter is designed so that the base on the first side of the mat bar is a flush surface, and an oversized picture mat may lie flat upon the base.
In one embodiment the cutter head may be reversed by releasing one end of the mat bar from the clamp frame. The cutter head can then be slid off of the cutter head guide rod, reversed and slid back on to the guide rod. Next, the mat bar is reattached to the clamp frame. Thus, the cutter head can cut on the second side of the mat bar. The mat guide and squaring arm can also be quickly removed from the first side of the mat bar so that an oversized picture mat can lie flat.
BRIEF DESCRIPTION OF THE DRAWINGS
The invention, together with further objects and advantages thereof, may best be understood by reference to the following description taken in conjunction with the accompanying drawings in which:
FIG. 1 is a perspective view of a prior art mat cutter.
FIG. 2 is a perspective view of a mat cutter in accordance with the present invention.
FIG. 3 is a top view of the mat cutter shown in FIG. 2.
FIG. 4 is an end view of the mat cutter shown in FIG. 3.
FIG. 5 is a fragmentary end view of the cutter head of FIG. 3.
FIG. 6 is a fragmentary frontal view of a portion of the mat guide of FIG. 3.
FIG. 7 is a top view of the mat cutter of FIG. 2 showing the placement of a picture mat for conventional cutting.
FIG. 8 is a perspective exploded view of the mat cutter of FIG. 2 showing how the mat cutter may be reversed.
FIG. 9 is a top view of the mat cutter after the mat cutter has been reversed showing the placement of an oversized picture mat.
DETAILED DESCRIPTION OF THE INVENTION
Turning to the FIGS. 2-9 of the appended drawings, a reversible mat cutter embodying the present invention will be discussed. FIG. 2 shows in general a reversible mat cutter 10 in a traditional arrangement. A base 12 is provided to support a picture mat. A clamp frame 14 is attached to the base 12 at pivots 16. The pivots 16 may take the form of hinges or any other conventional hinging mechanism. The clamp frame 14 is shown in its cutting position, but it can also be pivoted upward around pivots 16 to a raised position to receive a picture mat.
The clamp frame 14 carries a guide assembly 20. A cutter head 30 slides along the guide assembly 20 to facilitate the cutting of a picture mat. Mat guide mounts 40 which serve to position a mat guide 42 are recessed on either side of the guide assembly 20. Squaring arm mounts 50 which serve to secure a squaring arm 52 are also recessed on either side of the guide assembly 20.
Turning next to FIG. 3, a more detailed top view of the described embodiment is shown. The mat cutter 10 is shown having a base 12 with the clamp frame 14 lowered into the cutting position. The actual size of the base may vary widely with the needs of particular mat cutters. By way of example, a base having dimensions of approximately forty-eight inches by twenty inches works well for use in many typical frame shops. The clamp frame 14 consists of two arms 2 and 4 joined by a handle 6. The two arms 2 and 4 extend from the pivots 16 along opposite edges of the base 12 and are joined by the handle 6. The handle 6 mounts on the top at the end of each arm to allow space in which to grasp the handle for raising the entire clamp frame 14.
The guide assembly 20 includes a mat bar 22 and a cutter head guide rod 24. The mat bar 22 has the cutter head guide rod 24 mounted on its top surface. The cutter head 30 is slidably mounted on the guide rod. The mat bar has two tapered edges 26 which serve to guide the cutting blades on the cutter head 30 when a mat is being cut. The mat bar also has a broad flat-bottomed surface for pressing a mat against the base during cutting. The guide assembly 20 is carried by the clamp frame 14 by inserting each end of the cutter head guide rod 24 into circular openings 28 in the arms 2 and 4. The circular opening 28 in arm 2 contains a spring 29 which firmly holds the cutter head guide rod 24 in place and also allows the quick and easy removal of the guide assembly 20 from the clamp frame 14.
As best shown in FIG. 3, the cutter head 30 has two cutting blades mounted thereon. These include an angled blade 32 and a straight blade 34. When cutting a picture mat, either blade will extend through the picture mat into one of the cutting grooves 13 in the base 12.
The mat guide 42 can be mounted on either mat guide mount 40. Each mat guide mount 40 has a slot 44. A bolt 46 goes through the mat guide 42 and into the slot 44 where it screws into a large nut 48 in order to hold the mat guide 42 in position. The large nut 48 is positionable within the slot 44 in order to adjust the distance from the mat guide 42 to the guide assembly 20. The squaring arm 52 is secured to either squaring arm mount 50 with a bolt 54.
FIG. 4 is a side view of the reversible mat cutter with the clamp frame 14 shown in the raised position. In this position a picture mat may be easily placed on the base 12 for cutting. When lowered, the mat bar 22 will press a picture mat towards the base 12. In the lowered position, the mat bar 22 is supported by an island formed in the base 12 by cutting grooves 13. Also shown in particular is the bolt 54 which secures the squaring arm 52 to the squaring arm mount 50. The bolt 54 has a large head which makes it quickly and easily detachable by hand. The handle 6 of the clamp frame 14 is also shown mounted on the top at the end of each arm 2 and 4.
FIG. 5 shows in detail a side view where the clamp frame 14 is lowered into the cutting position. The cutter head 30 is mounted on the cutter head guide rod 24, and the mat bar 22 presses a picture mat M to the base 12. The tapered edges 26 of the mat bar 22 help to guide the angled blade 32. Either blade when cutting the picture mat M will extend into a cutting groove 13.
FIG. 6 is a frontal view of the mat guide mount 40. A bolt 46 extends through the mat guide 42 into the slot 44 to engage with the large nut 48. The bolt 46 has a large knurled head which makes it quickly and easily detachable by hand.
FIG. 7 shows a picture mat M to be cut placed on the reversible mat cutter 10 of FIGS. 3 through 6. The mat M is placed face down such that the side to be viewed in a picture frame is face down toward the base 12. The clamp frame 14 (not shown) is in its raised position, thus moving the guide assembly 20 (not shown), and cutter head 30 (not shown) off of the base 12 which allows easy placement of the picture mat M on the base. In this embodiment the picture mat M is shown pressed up against the mat guide 42 and the squaring arm 52. The mat guide 42 helps to align the edge of the mat substantially parallel with the cutting grooves 13 and also adjusts the distance of the edge of the mat from the cutting grooves. The squaring arm 52 helps to keep the mat from moving in a direction substantially parallel to the cutting grooves 13.
Once the clamp frame 14 (not shown) is lowered into the cutting position, the picture mat can be cut. The clamp frame 14 will hold the picture mat M firmly to the base 12. Mat M is placed such that when cut, the cutter head 30 (not shown) will cut along edge B of mat M. Once cut, mat M is removed, rotated 90 degrees counter-clockwise and reinserted on base 12 up against the mat guide 42. Mat guide 42 can also be adjusted to cut a wider or narrower border. In this position, the cutter head 30 will cut along edge C of mat M. Subsequently, mat M is removed, rotated, reinserted and cut twice more in order to cut along edges D and E. In this manner, an opening defined by edges B, C, D, E is cut in mat M.
FIG. 8 well illustrates a novel feature of the described embodiment whereby the cutter head 30 is reversible as well as the mat guide 42 to allow cutting on a reverse side of the guide assembly 20 in order to accommodate oversized picture mats. Firstly, the guide assembly 20 and specifically the cutter head guide rod 24 are pressed in the direction of arm 2 of the clamp frame 14. End 23 of the cutter head guide rod 24 is pressed into the hole 28 in arm 2 in order to compress the spring 29. End 25 of the cutter head guide rod 24 releases from the hole 28 in arm 4 and the guide assembly 20 is free of the clamp frame 14. Next, the cutter head 30 is slid off of the cutter head guide rod 24 and is reversed. FIG. 8 shows the reversed cutter head 30 being slid back onto the cutter head guide rod 24. Once the reversed cutter head 30 is reattached, end 23 of the cutter head guide rod 24 can be pressed back into hole 28 in the arm 2 to compress the spring 29. End 25 of the cutter head guide rod 24 can then be reinserted into hole 28 of the arm 4 in order to secure the guide assembly 20 to the clamp frame 14.
In another embodiment of the present invention, the cutter head 30 could be detachable from the cutter head guide rod without having to remove the guide assembly 20 from the clamp frame 14. One such cutter head would snap open to allow its removal from the cutter head guide rod 24, would be reversed, and then snapped back onto the cutter head guide rod 24.
FIG. 8 also shows that the mat guide 42 has been removed from side 15 of the base and can be mounted on side 17 of the base. Also, squaring arm 52 has been removed from side 15 of the base. In this manner, side 15 of the base becomes a flat surface and an oversized picture mat can lie flat. Furthermore, the present invention is designed so that the distance from the guide assembly 20 to the pivots 16 is larger than the distance provided in standard mat cutters. This larger distance provides that a large border can be cut on oversized picture mats. By way of example, standard mat cutters generally position the hinges about four inches from the mat bar. In contrast, I have found larger spacing to work well, as for example a spacing of seven inches.
FIG. 9 shows how the reversible mat cutter reversed as in FIG. 8 can accommodate an oversized picture mat. The mat guide 42 and the squaring arm 52 have been removed from side 15 of the base, allowing an oversized picture mat M to lie flat on the base and have beveled or straight openings cut in its interior. The picture mat M will be pressed up against the mat guide 42, and the reversed cutter head 30 will cut a beveled edge in edge D of the picture mat. In another embodiment of the present invention, an oversized picture mat can be cut in this fashion without the use of the mat guide 42.
Although only a few embodiments of the present invention have been described in detail, it should be understood that the present invention may be embodied in many other specific forms without departing from the spirit or scope of the invention. Particularly, the cutter head may be removed from the guide rod by another means instead of by sliding if off of one end. The cutter head may snap off of the guide rod, or perhaps the cutter head splits in half allowing it to be removed. The cutter head itself does not necessarily have to have one angled blade and one straight blade, it could have only one blade, or could have two angled blades or two straight blades. The cutter head guide rod does not need to be circular in cross-section; it could be of another geometry. Also, the mat bar may have one edge which is not tapered but is straight. Additionally, the mat guide and squaring arms, which are easily removable from the base, could themselves be recessed into the base when not in use, thus providing a flush surface. The clamp frame may be attached to the base by conventional hinges, or by another method which allows the clamp frame to swing up and down.
Therefore, the present examples are to be considered as illustrative and not restrictive, and the invention is not to be limited to the details given herein, but may be modified within the scope of the appended claims. | A reversible mat cutter for cutting openings in oversized picture frame mats is disclosed. In one aspect of the invention, the guide rod and mat bar are easily detachable from the clamping frame of the mat cutter. Once detached, the cutter head assembly is then easily removed, reversed and remounted on the guide rod such that the cutter head then cuts on the opposite side of the guide rod. Both the mat guide and squaring arm are both quickly and easily detached from one side of the guide bar and remountable on the other side so that then an oversized picture mat may then be lain flat on the mat cutter and cut with the reversed cutter head. | 8 |
CROSS REFERENCE TO RELATED APPLICATIONS
N/A
STATEMENT OF FEDERALLY SPONSORED R & D
N/A
REFERENCE TO A “SEQUENCE LISTING”
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BACKGROUND OF THE INVENTION
The increased popularity and installations of swim spas in many thousands of residences throughout the world has allowed thousands of people the ability to take advantage of physical therapy while being supported by the buoyant nature of water in their own homes. For many of these people, this type of exercise is prescribed by their doctors to rehabilitate certain physical injuries, to slow the effects of disabling diseases or just to enhance their physical wellness.
Swim spas are generally large enough in size to allow swimming in place, jogging and other exercises in the buoyancy of warm or hot water as prescribed by a medical professional. The swim spa is heated and filtered in the same way as a larger swimming pool yet only taking up a small space at the residence. Most swim spas are supplied with covers which are designed to keep the heat in and keep debris out of the water. These covers are rigid, heavy and cumbersome which require two people, in fit condition, to move them on and off the spa. For those who are disabled, elderly or physically unable to move the covers, they have to arrange with others to take care of the cover removal and replacement so they can use the swim spa for rehabilitation, exercises or just physical relaxation. The cover handling is the main complaint of most swim spa users which is why an alternative is needed which will allow just the user to remove the cover by him or herself, or if unable to do even this, would only need one helper who could easily remove and replace the swim spa cover to help keep the heat in and any debris out.
A secondary problem with the hard covers which are supplied with the spa is the seal between the several sections is typically a flap with Velcro which has to be put in place after the spa covers have been put back on the spa. If done right, the seal between the spa covers is fair and keep most debris and rainfall out of the spa water as long as the spa covers haven't started sagging or warping. The process of doing it right is a nuisance which most people decide is not worth doing. This leads to a higher cost of operation as heat is lost through the gaps and debris is allowed into the water. The end result is more energy is used to keep the spa water heated, more chemical use to treat the dirtier water, longer filtration time and more frequent filter maintenance.
I have come up with several design ideas for handling the existing hard covers but decided that a different approach was needed which has led to my creation of a roll-up swim spa cover. This cover can be removed and reinstalled by one person in reasonable physical shape and it will seal the spa, keeping heat in, debris out and maintenance down.
BRIEF SUMMARY OF THE INVENTION
The roll-up swim spa cover is a multi-layered device which is flexible enough to be rolled up upon itself yet strong enough to shed rain and debris while keeping the heat in the water.
The layers of different materials used are supported by square metal or fiberglass tubes which span the approximate 7.5 feet interior width of most swim spas. The layered design and attachment of the layered materials allows for the soft pliable materials to directly contact the bartop of the spa shell which keeps the heat in and the debris out.
The entire swim spa roll up cover is heavy and requires two people to put in place at one end of the spa. Once in place covering the whole spa, a single person can grasp the end of it and start rolling as one would roll up a sleeping bag. The flexibility of the layers of materials allows the cover, once started rolling, to be pushed, like rolling a log, to the end of the spa or anywhere in between. The weight of the layered, flexible material and the square support tubes keeps the cover in place wherever it is rolled to on the spa bartop.
If complete removal of the rolled up cover from the bartop is desired, it can be rolled onto a cradle assembly at the end of the spa. If the cradle assembly is set up with casters, the whole cover roll can be moved out of the way or out of sight.
An important and aesthetic part of the whole assembly is what I call the rainfly cover. It is a weather shield over the top of the whole roll up assembly which when stretched and strapped down on the ends will provide a domed cover which sheds rain, debris, pets, etc
The rainfly fabric is precisely tailored to fit on top of ⅜″ fiberglass rods which arc from one side of a square support tube to the other end of the same square support tube. The rod attachment to the square support tube is accomplished by the use of a 6 inch long molded plastic insert which is pushed into the end of the hollow square support tube. Since the insert is just slightly smaller than the hollow tube end, it should slide right into the tube ends and be secured in place by short ½″ pan head screws to lock it in place. The solid insert will give plenty of structural strength to support the rainfly rods as well as keep the ends of the hollow tubes from being crushed. The inserts have a ⅜″ rod which is molded into the plastic and exits the outside cap end making an immediate 170 degree bend back over the top of the square support tube. The rainfly rods have hollow tubes on the ends which slip over the end of the insert rod at a 10 degree arc to the opposite end of the same square support tube with its insert also protruding at a 10 degree angle. The rainfly fiberglass rod is compressed in an arc between the two inserts at the ends of the square support tube which then supports the rainfly material which is stretched over the rods much like a rainfly on a camping tent.
The rainfly fabric has a loop sewn onto it into which the rainfly rods are inserted through before being compressed onto the tube insert end studs. The resulting arc supports the rainfly approximately 8 to 9 inches high in the center when the cover is unrolled but not high enough to impede the rollup flexibility of the cover.
The rainfly structure is then held in place on the ends by straps which when secured, stretches the fabric perpendicular to the support rods, creating a nice, clean, taut, sloped surface which will shed rain and debris. Unlike hard style spa covers, the rollup cover appears soft and flexible which will help to discourage people and pets from trying to walk or sit on it.
DETAILED DESCRIPTION OF THE INVENTION
The roll-up spa cover assembly is described below with reference to the accompanying figures, wherein the noted elements have the following reference numerals in the drawings:
11 —length adjustable latching strap; 12 —square support tubes; 13 —rainfly assembly; 14 —round fiberglass rods; 15 —stainless steel panhead sheet metal screw; 16 —rainfly rod support end cap; 17 —nylon Christmas tree fastener; 18 —spa shell bartop; 19 —spa siding skirt; 20 —foam sheeting; 21 —EDPM rubber sheet; 22 —laminated vinyl fabric; 23 —aluminized double bubble insulation; 24 —metal coupling; 25 —stainless steel panhead sheet metal screw; 26 —spa; 27 —spa shell.
The manufacture of the roll up spa cover assembly requires several steps and can be made using two different types of flexible, water and chemical resistant fabrics or membranes. STEP 1 a uses an EDPM rubber membrane and STEP 2 a uses a laminated vinyl fabric.
STEP 1 a : Assembly of the “Bladder” using EDPM rubber membrane. A sheet of 60 mil Firestone Ecowhite EDPM rubber membrane is cut so that its' dimensions are 15 inches larger on each side than the spa shell surface area it is supposed to cover. It is important to cut the rubber membrane so that any seams in the material run parallel to the end sides of the spa shell. The rubber membrane is placed white side down on the assembly surface and clamped to hold in place.
A sheet of 5/16 th inch thick aluminized heat-reflective double-bubble insulation is cut so that its' dimensions are 3 inches larger on each side than the spa shell surface area and placed on the initial layer of 60 mil Ecowhite EDPM rubber. This layer of insulation is then temporarily fastened in place so placement of subsequent layers of other materials will not move it off its' centered placement.
Two sheets of ¼″ thick polyethylene closed-cell foam are then cut to the exact same size as the aluminized double-bubble insulation which is 3 inches wider than the spa shell dimensions on all sides. The two thinner sheets of polyethylene foam are used instead of a single ½″ thick foam because the thinner sheets are more flexible, there is not as much rollup compression and expansion as the thicker foam will experience and the finished surfaces of the foam material provides a stronger, longer-lasting cohesiveness of the closed-cell foam. This ½″ thickness of foam provides the minimum air space that the manufacturer of the reflective double-bubble insulation recommends for optimum infrared heat refection back down towards the water in the spa. These two sheets of foam are centered on top of the reflective insulation and temporarily fastened in place.
A final sheet of 45 mil or 60 mil EDPM rubber membrane is cut to the exact same size as the layers of insulation and foam. This layer of rubber is centered on top of the layers of insulation. From the plan view, there should be 12 inches of the bottom (or very first) layer of 60 mil Ecowhite EDPM rubber membrane exposed on all sides of the stack of insulation and rubber.
To complete the bladder assembly, the 12 inches of exposed rubber membrane is folded over the top (or last layer) of rubber and permanently attached using the proper adhesives made specifically for seaming the EDPM rubber membranes together. Wherever there may be an overlap of rubber material due to the shape of the spa shell or corners, the rubber membrane is cut so there won't be any overlap of materials which would prevent the rubber bladder from making a nice tight seal on the spa bartop.
STEP 1 b : Assembly of the “Bladder” using a vinyl laminated fabric instead of the EDPM rubber membrane. Vinyl laminated fabric is used in place of the rubber membrane to encapsulate the same layers of insulation in the same layering sequences and the same sizes as was used in making the rubber membrane “Bladder.” The laminated vinyl fabric has to be heat welded, glued or sewn together in order to make sheets large enough to create the “Bladder” encasement. It is important that any welded, glued or sewn seams be parallel to the end sides of the spa shell. The end result is that there will be a “bladder” assembly which has the same materials within it and ends up measuring three inches larger on all sides than the spa shell it is being made for.
Now the bladder assembly is complete and if it were placed on top of the spa it was made to fit, it would overlap the outside perimeter edge of the spa by 3 inches on the entire outside perimeter of the spa shell.
STEP 2 : Attaching the rigid square support tubes to the bladder. On an assembly table, 1.5″×1.5″×96″ square tubes are secured onto a rack which holds them 12 inches on center for the entire length of the spa shell. On curved or rounded spa shell ends, the square tubes may be place as close as 6″ apart to accommodate the clean look of a tight fitting and attachment points for the rainfly assembly around the perimeter of the curved areas of the spa shell. These tubes which are located in the curved areas will be cut so that they extend the same distance beyond the edge of the bladder as anywhere else on the cover assembly. The tubes on the very ends are either solid or reinforced because these are the most handled by use and will have the rainfly assembly attached with screws
The “Bladder” assembly is then positioned on top of the square tubes which have been inserted into the rack. The “Bladder” assembly is placed upside-down on the square tubes so that the side of the bladder which will face the water is now facing up and away from the square tubes.
At each of the square tube locations, a hole-drilling template is positioned directly above the square tubes on which the Bladder now lays. From the center of the Bladder, in intervals of 6 inches, a hole is drilled through the Bladder and into the square support tube. The drill bits are properly sized for whatever fastener type and size is used for maximum holding strength according to the fastener manufacturing specifications. The holes are equally spaced until the holes come within 8 inches of the edge of the Bladder. Fasteners are not installed within the 8 inch wide area of the perimeter because they would compromise the nice seal which the roll-up cover needs in order to meet the energy saving design of a nice tight seal provided by the roll-up cover assembly. The only place where fasteners are installed within the 8 inch perimeter zone would be on the very ends of the cover where square tubes are attached for hold down strap anchoring and rainfly attachment.
Once all the holes are drilled, the hole-drilling template is removed and a nylon push-in locking Christmas tree type fastener is pushed into the holes and into the square support tube which locks the bladder assembly to the tubes. A light tap with a hammer pushes the head of the fastener into the Bladder creating a dimple in the bladder so that none of the fasteners will be able to contact any surface the cover is placed upon. This same process continues until all square tubes have fasteners every 6 inches along its length to a location not within 8 inches to the edge of the bladder assembly.
Now that the bladder assembly is completely attached to the square support tubes the whole assembly needs to be removed from the square tube placement rack and placed square tube side up as it would sit upon the spa shell surfaces.
STEP 3 : Attaching the rainfly assembly to the roll-up spa cover assembly. The ends of the square support tubes can now be filled or capped with one of two types of square tube end caps. The caps need to be as smooth as possible to minimize friction points that may over time cause premature wear of the rainfly as it is attached to the square tubes on the capped ends. Regular square tube end caps which just fill the square tube ends and allow for the attachment of the rainfly are inserted into the open ends of the square tubes and fastened to the square tube with a screw so that the end cap cannot fall off the cover assembly. The screw attachment is made on the vertical side of the square tubes to keep the screw heads from ever contacting the bladder assembly or the rainfly assembly. These regular end caps are installed on the square tubes starting on the ends and on every other square tube which should put them every two feet apart.
Rainfly support end caps which are designed to support fiberglass rods, which are compressed into an arc between the ends of the square support tubes, are inserted and fastened in place into the open ends of the square support tubes. The rainfly support end caps are solid plastic blocks that are sized to fit exactly within the square support tubes to a depth of approximately six inches which will give the square support tubes excellent resistance to being crushed and give extra torque strength since these are supporting the rainfly. A ⅜ th inch thick zinc plated steel rod approximately six inches long is bent to an acute angle of 20 degrees so that two inches of it are on one side of the tight bend and the remaining four inches are on the other side. The four inch side of the rod can be deformed so that when molded into the plastic block that it will be anchored in place so that the two inch side of the rod exits the plastic block and points at a 20 degree angle back over the top of the filler block. The rainfly support end cap is then inserted into the ends of the square support tubes so that the metal rod is pointing directly over the top of the square tube and directly towards the other end of the same support tube. As with the regular end caps, the rainfly support end caps are screwed to the square support tubes on the vertical sides of the square support tubes.
Once all the open ends of the square support tubes are filled in, the fiberglass rods are compressed into place between the receiver for the fiberglass rod on one side of the spa cover assembly and the other side, directly above and parallel to the square support tube. The arc height must be approximately 9 inches so that when the cover assembly is rolled up, the arched fiberglass rod fits nicely between the square support tubes which will not hinder the roll-up process. Once all the rods are put in place, looking down the ends of the cover assembly, all of the fiberglass rods need to arc at the same height except the two rainfly rods at the ends of the cover assembly which may only peak out seven inches high which will give the roll-up spa cover a nice sleek appearance once the rainfly is attached.
The rainfly is a water-resistant reinforced vinyl fabric which is made to perfectly fit on top of the arched fiberglas rods and attach along the spa perimeter which gives the roll-up spa cover its' sleek appearance and weather protection. The rainfly is designed to fit snuggly over the fiberglass rods and to be attached to the square tube end caps which will keep the rainfly fabric taut. In order to keep the rainfly support rods in the proper location, a series of loops which are sewn, welded or heat seamed are added to the underside of the rainfly at the highest point so that the fiberglass rods can be inserted into the loop directly above the square support tubes. Once this has been done for each of the fiberglass rods, each rod can then be inserted into the rainfly support receivers on the rainfly support square tube on either end. The rainfly can then be centered over the arched rods and attached to the square tube endcaps.
The rainfly should now be attached to the square tube endcaps using #8×¾″ Phillips Truss head stainless steel screws. Starting at the middle of the cover, the rainfly fabric will be centered from side to side on top of the fiberglass support rods and fastened onto one of the center square tube endcaps with a ⅜th″ stainless steel washer to help spread out the pressure of the screw on a larger area of fabric. Now on the opposite end of the same center square tube the fabric will be pulled taut and fastened to the endcap with a #8×¾″ SS Phillips truss screw, ⅜″ SS washer and two ½″ nylon washers. The order the hardware is applied is one nylon washer between the rainfly and rainfly support end cap, then another nylon washer so that the fabric is sandwiched between the nylon washers. The screws with a washer will be driven into predrilled holes in the endcaps far enough to bottom out the screw heads onto the washers which in turn compress the fabric onto the endcaps. This procedure is duplicated from the center down to the ends. A key step in this process is to ensure that as the rainfly is stretched over the fiberglass rods and attached to the endcaps that the fiberglass rods are straight up and down as viewed from the side endcap positions at every square tube which supports the rainfly assembly.
The rainfly attachment to the rollup spa cover on the very end square tubes on a square ended spa is done using the same hardware used on the attachment of the rainfly on the ends of the square tube except the screws will penetrate every 6 inches starting from the center into the long side of the square tube facing away from the spa. On round ended spas, the rainfly attachment is at the ends of the square tubes as they extend just beyond the bladder assembly every six inches along the perimeter of the circular spa shape.
Now that the rainfly is attached to the framework at the edges of the roll-up cover, the adjustable straps which will keep the rainfly taut from end to end needs to be attached to the square tubes at each end of the cover assembly. There should be a main strap at the center of each end which is attached to the end square tube with two #8×¾″ SS Phillips truss screws. The strap should be sufficient in length to allow for locking length adjustment hardware to be installed somewhere between the bottom of the roll-up cover and the spa siding or decking around the spa. When these two main straps are attached, the spa cover rainfly should be pulled taut from one end to the other and latched down. Finally at two locations on either side of the main straps and at desired intervals down the sides, locking hold-down straps are added for child safety and extra wind restraints. The appearance of the roll-up cover assembly, when completely unrolled and strapped down should be a taut slightly domed structure covering the entire spa. With a 6 inch valence attached to the rainfly and hanging around the entire perimeter, the spa shell is protected from the weather and the appearance is clean.
The assembly of the roll-up spa cover is now complete and ready for easy roll-on and roll-off use for many years to come.
BRIEF DESCRIPTION OF THE SEVERAL VIEWS OF THE DRAWING
FIG. 1 Side view of a swimspa with cover completely on which shows the domed appearance of the cover when strapped down taut. Side view of a 19 foot long by 7.5 foot wide swimspa rollup cover showing how the cover will be domed when rolled out on the spa and end straps are locked in place stretching the rainfly to a smooth surface from end to end.
FIG. 2 Plan view of a 19 foot long by 7.5 foot wide swimspa rollup cover without the rainfly which shows the 12″ spacing between the square support tubes down the whole length of the spa and perpendicular to its length.
FIG. 3 Section endview of a 19 foot long by 7.5 foot wide swimspa rollup cover showing the arched rainfly assembly from side to side. Please note that FIGS. 1 , 2 and 3 show a swimspa with rounded ends. The same construction applies to all other shapes and sizes of spas and swimspas.
FIG. 4 Detailed cross section view of a complete roll up spa cover as it rests on the spa bar top as viewed from the end of the spa. Starting from the top of the spa shell bartop, the bladder assembly rests directly on top of the bartop and in this area there are not any of the nonmetallic push-in fasteners which may keep a good thermal seal from occurring. The bladder is attached to the bottom of the square support tubes with nonmetallic push-in fasteners so the bladder assembly essentially hangs from the square support tubes over the water surface but not in contact with it. A rainfly support endcap is inserted into the end of the square support tube and fastened in place with a small panhead set screw. The endcap assembly has an attachment built into it so a fiberglass rod can be attached and arched over the width of the spa to the endcap assembly on the other end of the same square support tube. The fiberglass rod supports the water-repellant rainfly which is attached at each of the rainfly support endcap using a stainless steel screw.
FIG. 5 Cross section view of roll up spa cover materials used in the bladder assembly.
FIG. 6 Cross section view of the bladder assembly attached to square support tubes
FIG. 7 Detailed cross section view of complete rollup cover resting on a bartop of spa as viewed from the side of spa.
FIG. 8 Detailed drawing of rainfly support endcap application. The endcap assembly is injection molded to fit snuggly in the end of the square support tubes and with finished smooth edges on the side facing the rainfly material to keep friction to a minimum at any contact points. Molded into the endcap insert is a ⅜ th inch thick metal stud or a hollow receiver tube into which the fiberglass rod is inserted and bent between the two attachment points creating an arc. Attachment screws or similar fasteners hold the rainfly which is stretched over the fiberglass rods which arc from side to side over the bladder and square support tube assembly.
FIG. 9 Section long side view of spa with rollup cover partially removed for FRONT PAGE VIEW | A spa cover constructed of layers of pliable insulation encapsulated within a weatherproof vinyl reinforced fabric or a rubber membrane which is attached to rigid square support tubes that run parallel to the short end of the spa. The encapsulated insulation is fastened to the bottom of the square support tubes with corrosion-free nylon anchors which allows the soft insulation assembly to span over the water and rest directly on the spa bartop surface sealing the heat in and keeping debris out. An arched fiberglass rod structure supports a weatherproof rainfly which is permanently affixed to the flat cover assembly to shed rain and debris. The entire assembly is held in place at each end with adjustable straps which stretch the cover from end to end keeping the rainfly taut. Removing the cover to access the spa involves undoing the straps on one end and rolling the cover assembly towards the other end until the desired amount of spa exposure is reached. Covering the spa after use is just the opposite procedure. | 4 |
FIELD OF THE INVENTION
This invention relates to electrical connecting devices, particularly to an electrical adapter plug that may be inserted into the socket or receptacle of a direct-current electrical system cigarette lighter assembly to operate various electrical loads.
BACKGROUND OF THE INVENTION
In recent years, a great variety of electrical appliances have become available for operation by the low voltage power of direct-current electrical systems found in vehicles. Such appliances are generally interconnected to the electrical system by use of an adapter plug or connector, which is inserted into a cigarette lighter socket or receptacle. Electrical appliances and accessories that can be operated from a vehicle electrical system include battery chargers, portable televisions, cellular phones and the like.
There are generally two standard diameters of cigarette lighter sockets. The American and Japanese standard is about 20.9 millimeters, while the European standard is about 22.3 millimeters. Known adapter plugs are designed for use with only one standard receptacle size. Each prior art design includes by necessity dimensions tailored to the particular socket size intended for use. It is therefore desirable to design an adapter plug that is compatible with a plurality of standard sizes and which will not loosen or eventually lose electrical contact when subject to vibration or shock when positioned within any of the standard socket diameters.
In general, existing adapter plug designs each have only one or two spring contacts for mating with the socket receptacle. Some plug designs have placed contacts in varying positions around the plug surface to provide an offset force and thereby more soundly hold the plug in place.
If there are two or more contacts, they are typically angularly spaced around the periphery of an adapter plug. For example, U.S. Pat. No. 4,988,315 to Wharton, incorporated herein in its entirety by reference, discloses an adapter plug having two spring contacts radially positioned opposite each other at an angle of less than 180 degrees.
Another prior art design includes a cylindrical plug sleeve which slidably fits around the tubular adapter plug body perimeter to broaden the diameter of the plug body. However, the plug sleeve presents the user with the inconvenience of determining whether use of the sleeve is necessary, locating the sleeve and inserting the sleeve over the plug body in the proper position. Also, the sleeve adds a significant cost to the manufacture and shipment of the adapter plug.
Thus, none of these designs self-adjusts to a variation in the diameter of the socket. In a larger socket, a plug designed for a smaller diameter will be free to pivot around the contact points which is likely to cause the plug to loosen and eventually break electrical contact with the electrical system when subjected to vibration or jarring. Conversely, a plug designed for a larger diameter will not fit into a small standard sleeve size.
SUMMARY OF THE INVENTION
It is therefore a principal object of this invention is to greatly improve the retention of an adapter plug within a receptacle sleeve.
Another object of this invention is to attain a more reliable electrical connection between an adapter plug and its socket or retention sleeve in response to intense vibration or severe jarring.
A further object of this invention is to greatly improve the retention of an adapter plug within a receptacle sleeve regardless of minor variations in the standard diameter of such receptacle sleeves.
Still another object of this invention is to reduce pivoting of an adapter plug within a receptacle sleeve despite vibration and jarring of the plug relative to the sleeve.
Yet another object of this invention is to provide an electrical adapter plug comprising a cylindrically shaped housing, an electrical contact at one axial end of said housing and at least one additional electrical contact at the radial surface of said housing for connection to corresponding contacts within a hollow cylindrical connector, a mechanical compensator for providing a selected minimum frictional engagement between the housing and the connector despite differences in respective diameters of the housing and the connector to assure proper electrical interface between the plug contacts and the connector contacts. The mechanical compensator comprises a base member formed integrally with said radial surface, a tip member nominally extending away from said housing for engagement with said connector, and an elongated member integral to said base member and to said tip member and being flexible for limited radial movement relative to said housing.
The invention features a novel dimple, flexibly and integrally located on the periphery of an adapter plug body. The flexibly mounted dimple establishes improved mating contact with the cylindrical socket of a cigarette lighter receptacle when the adapter plug is inserted into the receptacle. Moreover, the improved mating characteristics of this invention are retained despite variations in standard receptacle sleeve diameter.
A preferred embodiment of the invention, includes two integral, flexible dimples. The dimples are preferably disposed diametrically opposite one another on the periphery of the adapter plug body, but may be disposed at various smaller angles. When used in conjunction with spring loaded electrical contacts, a plurality of contact points with the receptacle sleeve are formed.
BRIEF DESCRIPTION OF THE DRAWINGS
In order that all of the structural features for attaining the objects of this invention may be readily understood, reference is herein made to the drawings wherein:
FIG. 1 is a cross-sectional view of the adapter plug of the present invention.
FIG. 2 is a top view of the adapter plug of the present invention.
FIG. 3 is a cross-sectional view of the adapter plug of the present invention rotated ninety degrees relative to the view of FIG. 1.
FIG. 4A is a close-up view of the dimple feature of the present invention.
FIG. 4B is a cross-sectional close-up view of the dimple feature of the present invention.
FIGS. 5A, 5B and 5C show a cross-sectional view of the adapter plug of the present invention outside of a receptacle in a relaxed state (5A), inserted into a large diameter receptacle and partially compressed (5B), and inserted into a small diameter receptacle and fully compressed (5C).
DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENT
A preferred embodiment of electrical adapter plug 10 of the invention is shown in FIG. 1. The principal novel structural feature of this embodiment resides in the use of flexible dimples 8, flexibly and integrally located on the periphery of adapter plug casing 1. Biased outwardly from casing 1, the flexibly mounted dimples establish improved mating contact with the electrically conducting surfaces of a cylindrical sleeve of a cigarette lighter receptacle, such as shown in FIGS. 5B and 5C, when the adapter plug 10 is inserted into the receptacle sleeve in order to power an electric device connected to chord 100.
To provide electrical connection between the adapter plug 10 and a receptacle sleeve, retractable side electrical contacts 3 and tip contact 6 are located on either side of and on top of casing 1, respectively. These establish electrical contact with the receptacle sleeve conducting surfaces. Contacts 3 are preferably formed from a unitary strip of conductive material, shaped to provide an outward bias away from casing 1 in a manner known to a skilled artisan. Tip contact 6 is also outwardly biased by central contact spring 5, fastened to central connector 24. The key electrical components of the adapter plug are located on circuit board 2, predominantly within lower portion 28 of casing 1. Side contacts 3 are connected to lower connector 26. Tip contact 6 is electrically connected to central connector 24 via contact spring 5. Connectors 24 and 26 are electrically connected to circuit board 2. Cable 100, also connected to circuit board 2, completes the transmission of electrical power from the source, through the contacts and circuit board, and finally to the destination device.
Referring to FIG. 2, the top portion of a preferred embodiment of the present invention is shown in a fully relaxed state. Electrical contacts 3 and 6, as well as flexible dimpled members 8, will provide the necessary electrical and structural contact points, respectively, with a cigarette lighter sleeve receptacle to retain the desired electrical connection from the receptacle sleeve conducting surfaces to a device dependent on a DC power source.
To ensure proper fit of the plug 10 into a receptacle sleeve, when relaxed, the outer-most diameter of adapter plug 10 preferably exceeds slightly the largest internal diameter of standard receptacle sleeves. Similarly, the fully compressed diameter of the plug is preferably the same as or sightly less than the smallest internal diameter of standard receptacle sleeves.
FIG. 3 illustrates a cross-sectional view of a preferred embodiment of the present invention rotated 90 degrees from the view of FIG. 1. Dimple biasing spring 9 provides an outward bias for flexible dimples 8. The biasing force of spring 9 augments the biasing force provided by the nature of the plastic connection between flexible dimple 8 and casing 1. The pre-shaped and preferred plastic casing will resist any compression force of a receptacle sleeve wall. Spring guiding extension 7, integral with either of the flexible dimples 8, provides lateral support for dimple biasing spring 9. Inward pressure from a receptacle sleeve on contacts 3 and 6 and on dimples 8 is absorbed by the various biasing members described above.
FIGS. 4A and 4B provide close-up views of dimple member 8, integral with casing 1. Tip portion 11 is preferably convex, but may be any shape compatible with the intended use of the dimple member, i.e., rounded or circular. Tip 11 provides a primary physical contact point with the receptacle sleeve. Hinge points 12 delineate the preferred pivot line of member 8 relative to casing 1 when tip 11 is subjected to inward pressure from a receptacle surface. Elongate portion 13 is integral with tip portion 11. As illustrated in FIG. 4B, elongate portion 13 is preferably long enough to allow flexing of the dimpled member without breakage. The actual length of elongate portion 13 is, therefore, dependent upon the material used to fabricate casing 1 and the thickness of the dimpled member. Elongate portion 13 is preferably tapered along interior surface 14 to provide member 8 increased flexibility and to avoid decreasing the interior diameter of casing 1 upon compression of flexible member 8. Gap 15 appears between member 8 and casing 1 to allow free movement of the tip and elongate portions relative to the casing. Gap 15 need not surround member 8 on three sides, but could, instead, merely provide free movement of tip portion 11 relative to casing 1 sufficient to extend and narrow the outer-most diameter of plug 10.
FIGS. 5A, 5B and 5C illustrate the inventive element of the present invention in various states of use. FIG. 5A provides a cross-sectional view of top portion 22 of casing 1 in a relaxed position, revealing dimpled members 8, biasing spring 9, spring guiding extension 7 and side contacts 3 fully extended outwardly from casing 1. As shown in FIG. 5B, when top portion 22 is inserted into large diameter receptacle sleeve 20, a plurality of contact points are created around the plug periphery of adapter plug 10, in contact with receptacle sleeve 20. Dimple members 8 and side contacts 3 are partially compressed in response to the inward force applied by sleeve 20. The plurality of contact points function to provide plug retention despite the existence of gap 30 between plug 10 and sleeve 20. The various biasing mechanisms and springs diminish pivoting of the plug within the receptacle sleeve and reduce the effects of vibration and jarring which might tend to pull the plug out of the receptacle sleeve. Thus, though the fully relaxed outer diameter of plug 10 preferably exceeds a standard sleeve size, the plug will securely fit within the sleeve when inserted.
Similarly, as shown in FIG. 5C, when top portion 22 is inserted into small diameter receptacle sleeve 18, a continuous contact line or plurality of contact points is created around the periphery of casing 1 within receptacle sleeve 18. The various biasing mechanisms and springs provide the outward force necessary to hold plug 10 within receptacle 18 until the user desires to remove the plug.
A general description of the device of the present invention as well as a preferred embodiment of the present invention has been set forth above. One skilled in the art will recognize and be able to practice many changes in many aspects of the device described above, including variations that fall within the teachings of this invention. The spirit and scope of the invention should be limited only as set forth in the claims which follow. | An electrical adapter plug insertable into cigarette lighter-type sockets of varying diameters. The plug features a flexible dimpled member integrally joined with the periphery of the plug to provide a variable outer plug diameter. An internal spring provides an outwardly biasing force to increase resistance against vibration and jarring and improve retention of the plug within the socket. | 7 |
BACKGROUND OF THE INVENTION
[0001] The present invention relates to a pressure relief valve for a packaging container with significantly improved sealing properties.
[0002] Various embodiments of pressure relief valves for packaging containers are known from the prior art. The use of valves, especially on flexible packages for foodstuffs, has already been implemented by a large number of technical variants. A principal requirement on valves of this kind is that they should permit only slight excess pressures in the package through appropriate opening and otherwise should reliably prevent the penetration of ambient air. In this context, the penetration of ambient air must be prevented even when the pressure in the package is very low. In practice, however, the two above-mentioned aims are in conflict since, on the one hand, the pressure for opening the valve should only be low and, on the other hand, high vacuum tightness should be provided. Valves which have a high vacuum tightness therefore also have a very high opening pressure. In contrast, valves with only a low opening pressure do not have the necessary vacuum tightness.
[0003] EP 1 802 537 B1 has disclosed a pressure relief valve which is designed to be uneven in part in a recess in a main body. This results in differences in the distance between the recess and a valve diaphragm in different zones. This valve has fundamentally proven its worth but very recently there have been an increasing number of uses which require an improved opening characteristic and vacuum tightness.
SUMMARY OF THE INVENTION
[0004] In contrast, the pressure relief valve according to the invention for a packaging container has the advantage that it consists of a minimum number of parts and is constructed in a simple and economical manner. Moreover, the pressure relief valve according to the invention has high vacuum resistance (tightness), on the one hand, and, on the other hand, allows opening even with small pressure differences between a pressure in the interior of the packaging container and an outer side in order to release this pressure to the outside. According to the invention, this is achieved by virtue of the fact that the pressure relief valve has a main body with an inward-tapering sealing surface and a diaphragm which rests on the sealing surface in order to seal off a central through opening. On the side of the through opening oriented toward the diaphragm, said opening has an annular bead projecting from a recess in the main body. According to the invention, this ensures that, when the vacuum in the packaging container is very high, the diaphragm rests not only against the sealing surface of the main body but also against the annular bead around the through opening and thus provides very reliable sealing of the vacuum in the packaging container. A fluid is furthermore provided between the diaphragm and the tapering sealing surface, the inward-tapering form of the sealing surface ensuring that the thickness of the layer of fluid between the sealing surface and the diaphragm is somewhat greater on an inner side than on an outer side. As a result, larger capillary retaining forces are provided on the outer side, ensuring more secure seating of the diaphragm on the sealing surface. On the one hand, this ensures leaktightness relative to a high vacuum in the packaging container by virtue of the relatively high forces on the outer side of the sealing surface and, on the other hand, permits easier opening by virtue of the somewhat lower forces on the inner area of the sealing surface, with the opening forces during the opening process increasing continuously owing to the continuously increasing diaphragm surface area exposed to the excess pressure in the packaging container, thus ensuring more rapid opening.
[0005] The central through opening in the main body is preferably of tapering design. This makes it possible to influence the flow behavior of gases released to the outside from the packaging container. As a particularly preferred option here, the central through opening tapers in the direction of the interior space. This makes it possible to obtain a diffuser effect as gas flows out of the interior of the packaging container, thus providing more rapid opening and/or opening even with only very small pressure differences in a range of less than 500 Pa. The central through opening is preferably of conical design.
[0006] More preferably, a level of the annular bead relative to the inner side of the packaging container is below a level of an inner edge of the sealing surface of the main body. Here, the word “level” is intended to mean a plane perpendicular to a center line of the main body, said level being defined from a side of the pressure relief valve which is oriented toward the inside of the packaging container.
[0007] More preferably, the diaphragm has a deformable surface oriented toward the sealing surface in addition to the flexible properties. Even better vacuum resistance is thereby achieved since a deformation of the surface of the diaphragm takes place at the sealing surface during the sealing process, leading to reduced thicknesses of fluid between the diaphragm and the sealing surface.
[0008] According to another preferred embodiment of the invention, the pressure relief valve furthermore comprises an annular retaining device, which is formed integrally with the main body. This retaining device prevents the diaphragm coming away from the main body in an unforeseen manner.
[0009] More preferably, the central recess in the main body is formed in two stages with a base recess and a stepped region, which lies at a somewhat higher level. In this arrangement, an outer contour of the base recess is formed in such a way that it corresponds to an outer contour of an eight. In other words, the outer contour of the base recess describes the shape of two intersecting circles, it being possible for said circles to have the same radii or different radii.
[0010] The deformable surface of the diaphragm is preferably made of EPDM or NBR or silicone rubber. As an alternative, it is also possible for the entire diaphragm to be produced from one of these materials. These materials ensure the necessary flexibility of the diaphragm and the same or deformable surface while contributes to the improved sealing properties.
[0011] According to another preferred embodiment of the invention, the through opening has a bottom region with a perforation made therein. As an alternative, a filter element is arranged on the through opening. Both the perforation and the filter element have the filtering function in order to prevent the possibility of small particles accidentally entering the pressure relief valve.
[0012] The peripheral region of the main body, said region being used to fix the pressure relief valve to the inner side of the packaging container, is preferably designed in such a way that the peripheral region has an inner ring, an outer ring and a central ring, the central ring projecting further from a base surface than the inner ring and the outer ring. It is thereby possible, especially during an ultrasonic sealing operation, to ensure that any particles formed do not fall into the interior of the pressure relief valve or toward the outside during the sealing operation but are collected between the central ring and the outer ring or the inner ring.
[0013] The pressure relief valve according to the invention is preferably used on food packaging, especially that for powdered goods, e.g. coffee.
BRIEF DESCRIPTION OF THE DRAWINGS
[0014] A preferred illustrative embodiment of the invention is described in detail below with reference to the accompanying drawing, in which:
[0015] FIG. 1 is a schematic sectional view of a pressure relief valve in accordance with one illustrative embodiment of the invention,
[0016] FIG. 2 is a schematic sectional view, on an enlarged scale, of the main body of the pressure relief valve, said body being shown in FIG. 1 ,
[0017] FIG. 3 is a schematic plan view of the main body, and
[0018] FIG. 4 is a schematic sectional view of the main body.
DETAILED DESCRIPTION
[0019] A pressure relief valve 1 in accordance with a preferred illustrative embodiment of the invention is described in detail below with reference to FIGS. 1 to 4 .
[0020] As can be seen from FIG. 1 , the pressure relief valve 1 comprises a main body 4 and a diaphragm 6 . The main body 4 has a sealing surface 14 , which tapers conically inward in the direction of a center line X-X. A fluid 5 is arranged between the sealing surface 14 and the diaphragm 6 and forms a thin layer of fluid. This layer of fluid becomes continuously somewhat thicker from an outer edge 15 of the sealing surface 14 to an inner edge 16 .
[0021] A filter element 8 is provided in a small recess 8 a on a side 7 of the main body 4 which is oriented toward the inner side of a package in the assembled condition. More particularly, the filter element 8 covers a central through opening 9 and prevents small particles from being able to flow into the through opening 9 and thus into the pressure relief valve 1 .
[0022] The pressure relief valve 1 is arranged on an inner side 3 a of the package 3 . A plurality of outlet openings 3 b, the inner opening region of which is covered by the pressure relief valve 1 from the inner side 3 a, are furthermore arranged in the package 3 . On the one hand, the pressure relief valve 1 ensures that no gas or no fluid can enter an interior space 2 of the package 3 from an outer side 11 , and furthermore ensures that, when there is an excess pressure in the interior of the package 3 , said pressure can be released to the outside via the pressure relief valve 1 .
[0023] In addition to the sealing surface 14 , the main body 4 has a central recess 30 . The central recess 30 comprises a base recess 31 , which forms a bottom surface of the central recess 30 , and a stepped region 32 , which is arranged radially to the outside of the base recess 31 . In this arrangement, a level of the base recess 31 is lower than a level of the stepped region 32 . It should be noted that the term “level” is intended to refer to a plane perpendicular to the center line X-X, where defining a level as lower means that said level is closer to that side 7 of the pressure relief valve 1 which is oriented toward the inside in the package.
[0024] The central through opening 9 is also arranged in the central recess 30 and, as can be seen especially from FIG. 1 , the central recess 30 widens conically outward, i.e. in the direction of the diaphragm 6 . An annular bead 12 projecting from the base recess 31 is provided in the opening region of the central recess 30 . A level of the annular bead 12 is above a level of the stepped region 32 but below a level in which the encircling inner edge 16 is situated (cf. FIG. 2 ).
[0025] An encircling outer annular groove 13 is furthermore provided radially to the outside of the sealing surface 14 . A peripheral region 18 , by means of which the pressure relief valve 1 is fixed on the inner side 3 a of the package 3 , is furthermore arranged adjacent to the outer annular groove 13 . This fixing is preferably accomplished by means of an ultrasonic sealing method. As can be seen from FIG. 2 , the peripheral region 18 has a central ring 19 , an outer ring 20 and an inner ring 21 . The central ring 19 projects further relative to a base surface 25 than the outer ring 20 and the inner ring 21 . The base surface 25 thus forms recesses between the inner ring 21 and the central ring 19 and between the central ring 19 and the outer ring 20 . Any particles produced during the fixing process can be collected in these recesses, thus making it possible to prevent said particles from falling into an inner area of the pressure relief valve 1 . As can furthermore be seen from FIG. 2 , an encircling retaining ring 22 , which projects radially inward, is formed on a radial inner side of the inner ring 21 . The retaining ring 22 is likewise formed integrally with the main body 4 and prevents the diaphragm 6 coming away accidentally from the main body 4 . The retaining ring 22 thus serves to hold down the diaphragm 6 .
[0026] The diaphragm 6 is produced from a flexible material and has a soft and deformable surface 6 a. This soft and deformable surface 6 a is the surface of the diaphragm 6 which is oriented in the direction of the sealing surface 14 of the main body 4 .
[0027] As can furthermore be seen from FIG. 3 , an outer contour of the base recess 31 is formed in such a way that said outer contour corresponds substantially to an outer contour of an eight. Here, the central through opening 9 is arranged centrally. Designing the outer contour of the base recess 31 in the form of an eight in this way provides improved flow behavior when there is a release of gas from the interior 2 of the packaging container 3 to the outer side 11 . The constricted regions 33 of the outer contour allow directional outflow from the central through opening 9 , enabling an opening process of the diaphragm to be assisted. This ensures that the pressure relief valve 1 can open at even smaller pressure differences between the interior 2 and the outer side 11 .
[0028] The pressure relief valve 1 according to the invention operates as follows. If there is a strong vacuum in the interior 2 of the packaging container 3 , the pressure relief valve 1 must allow reliable sealing relative to the outer side 11 . The strong vacuum deforms the flexible diaphragm 6 , causing it to rest sealingly on the sealing surface 14 of the main body 4 . Given an appropriately high vacuum, the deformation can furthermore be such that the diaphragm 6 also rests on the annular bead 12 . Since the diaphragm 6 has a soft and deformable surface 6 a, there is additionally a deformation in the contact areas, and the inward-tapering sealing surface of the sealing surface 14 ensures that the deformation is somewhat more pronounced at the outer edge 15 than at the inner edge 16 . As a result, a thickness of a fluid 5 , especially in the region of the outer edge 15 , decreases to a very low level, with the result that high capillary forces and adhesion forces act here and ensure particularly high leaktightness. In this case, the fluid 5 forms a particularly thin film in the region of the outer edge 15 .
[0029] If the pressure in the interior of the package 3 is above a pressure on the outer side 11 , this pressure must be released via the internal pressure valve 1 and the through openings 3 b in order, in particular, to avoid inflation of the packaging container 3 . If there is an excess pressure in the interior 2 , a pressure-induced force thus acts on the inner side of the diaphragm 6 . If the diaphragm 6 is resting on the annular bead 12 in order to provide sealing, the pressure-induced force can thus act only via the area bounded by the inner edge of the annular bead 12 . Since, however, the central through opening 9 widens conically outward, the pressure in this region rises somewhat, thus ensuring that the diaphragm 6 lifts slightly from the annular bead 12 . Since the capillary or adhesive forces of the layer of fluid in the region of the inner edge 16 are furthermore somewhat lower, owing to the tapering arrangement of the sealing surface 14 , the pressure relief valve can open, since the pressure can now act on a larger area of the diaphragm 6 (namely the sealing surface defined by the inner edge 16 ), if the resulting pressure-induced forces on the diaphragm 6 are greater than the capillary or adhesive forces which hold the diaphragm 6 on the sealing surface 14 . Thus only comparatively small pressure-induced forces are required to overcome the capillary forces in the region of the inner edge 16 . Owing to the flexibility of the diaphragm 6 , the area of application increases further as a result, and therefore the internal excess pressure can then always act on an increasing area of the diaphragm 6 , and an opening process can be carried out correspondingly more rapidly. In this context, FIG. 1 shows an opened state of the pressure relief valve 1 , in which the gas can flow out of the interior via gaps between the diaphragm 6 and the peripheral region 18 into a region 10 between the diaphragm 6 and the inner side 3 a of the packaging body and from there via the passage openings 3 b to the outer side 11 .
[0030] It is thus possible, according to the invention, to provide a pressure relief valve 1 of simple construction which consists of just two parts, namely the main body 4 and the diaphragm 6 . By virtue of the arrangement according to the invention of the central through opening 9 with the corresponding annular bead 12 , it is possible, on the one hand, to obtain improved opening behavior and, on the other hand, also improved vacuum tightness. | The invention relates to a pressure relief valve for a packaging container ( 3 ), comprising a base body ( 4 ) with a central through opening ( 9 ), a sealing surface ( 14 ) and a peripheral region ( 18 ), wherein the peripheral region ( 18 ) may be sealingly connected to an inner side ( 3 a ) of the packaging container ( 3 ) and the sealing surface ( 14 ) has an inwardly tapering form and a membrane ( 6 ), making contact with the sealing surface ( 14 ) to permit a seal wherein a fluid ( 5 ) is arranged between the sealing surface ( 14 ) and the membrane ( 6 ). The membrane ( 6 ) is flexible and a recess ( 30 ) is made in the base body ( 4 ) into which the central through opening ( 9 ) opens out, wherein in the opening region of the central through opening ( 9 ), an annular bead ( 12 ) projecting in the direction of the membrane ( 6 ) is arranged, projecting into the recess ( 30 ). | 8 |
BACKGROUND OF THE INVENTION
1. Field of the Invention
This invention relates to apparatus for developing photographic materials, such as photographic sheets, photographic film and the like.
In particular, the invention relates to such a developing apparatus which has two or more containers for respective treating baths, through which the photographic material must travel in succession.
2. The Prior Art
Not all photographic materials are processed in the same way. Some require more processing steps or different treating chemicals than others. To make developing apparatus of the type here under discussion more flexible, i.e., more adaptable to these different requirements, it has already been proposed not to use a single large container and to subdivide it into a plurality of chambers for the treating baths, but instead to use a plurality of individual containers each of which is dimensioned to accommodate one of the treating baths. The apparatus can then be adapted for different requirements by simply adding or removing the requisite number of containers.
Such containers have a removable cover which closes them against the entry of light. Also, to permit travel of the photographic material into and out of the respective container, each such container has ports. The ports of successive containers are connected by guide elements through which the photographic material travels.
From time to time it is necessary to remove the cover of the respective container, e.g., for inspection purposes, for cleaning or for other reasons. When this occurs, it is important to prevent the incoming light from passing through the guide elements into the preceding and/or succeeding containers. For this purpose it has been proposed to mount a movable flap or door at each port, which closes automatically when the cover is removed. The disadvantage of this proposal is that the flaps contact the photographic material and tend to damage it (e.g., scratch the photographic emulsion). This is a particular danger if the machine is in operation and the material therefore in movement, when the cover is removed.
According to another proposal, lighttraps are arranged between the ports of the successive container. These traps prevent the travel of light between the containers by defining an interior passage in which the photographic material (e.g., a film) is forced to travel in a series of loops. Since the containers must usually be located close together to save space, the trap cannot be long and hence the loops must be very tight so that the requisite number of loops can be accommodated. Photographic material which is processed in this kind of apparatus must be available as a long band; hence, successive films, film strips or the like are glued or otherwise joined together to form this band which then travels through the apparatus. When the joints travel through the tight loops in the prior-art light traps, however, they tend to separate because of the small radii through which the material is deflected as it negotiates the loops.
SUMMARY OF THE INVENTION
It is an object of the invention to overcome the prior-art disadvantages.
More particularly, it is an object of the invention to provide a developing apparatus of the type under discussion, in which the travel of light from one to another container is reliably precluded without damage to the photographic material.
Another object is to provide such an apparatus in which separation of the joints of photographic material is avoided.
An additional object of the invention is to provide such an apparatus wherein the problem of preventing light-transfer between successive containers is solved in a simple and economical manner.
In keeping with these objects and with others which will become apparent hereafter, one aspect of the invention resides--in an apparatus for developing photographic material--in a combination comprising at least two adjacent containers each adapted to contain a treating bath for photographic material, the containers having respective ports which face one another; and means forming a passage which connects the ports and through which the photographic material travels from one to the other of the containers, and including a light trap in the passage and defining a substantially straight-line travel path for the photographic material.
The novel features which are considered as characteristic for the invention are set forth in particular in the appended claims. The invention itself, however, both as to its construction and its method of operation, together with additional objects and advantages thereof, will be best understood from the following description of specific embodiments when read in connection with the accompanying drawing.
BRIEF DESCRIPTION OF THE DRAWING
FIG. 1 is a fragmentary vertical section through two successive containers of an apparatus embodying the invention; and
FIG. 2 is a section on line II--II of FIG. 1.
DESCRIPTION OF THE PREFERRED EMBODIMENTS
The drawing shows only those elements of a developing apparatus for photographic materials (such as films) which are required for an understanding of the invention. In all non-illustrated respects the apparatus corresponds to those which are already known per se.
With this in mind it will be seen that reference numeral 1 designates a wall of a fragmentarily shown container C1. Adjacent to it is located a wall of a similarly fragmentarily shown container C2. Each of these containers is adapted to accommodate a treating bath, and a band of photographic material 17 (e.g., a series of appropriately joined films) is made to travel sequentially through these baths. Merely for completeness, a pair of transporting rollers T has been illustrated; these are intended to be representative of the transporting devices which are conventionally used in such developing apparatus to transport the material 17, and which are known per se.
The wall 1 has a (here circular) port 2 which faces a similar port 5 in wall 4. The containers C1 and C2 have respective removable covers 3, 6 which are shown only fragmentarily. The location and dimensioning of the ports 2, 5 is identical for all of the containers (there may self-evidently be more than the two illustrated containers C1, C2) so that any one container can be connected with any other container.
Such connection is established by means of a connecting element 7. As shown in FIG. 1 this element includes a conduit 8 of elastically deformable material (e.g., natural or synthetic rubber, or synthetic plastic material such as polyethylene, polyvinyl chloride or the like). Conduit 8 is connected to the containers C1, C2 by simply inwardly deforming its reduced-diameter end portions, inserting them into the ports 2, 5 and releasing the deformation pressure so that the end portions return to their original size and shape and snugly engage the surfaces bounding the ports 2 and 5. Since the center portion 9 has a larger outer diameter than the end portions it forms with them respective shoulders against which the walls 1 and 4 abut. Thus, the conduit 8 is firmly held against displacement. Of course, the conduit 8 could also have a constant outer diameter and be formed with grooves (e.g., annular grooves in its end portions) into which projections or the wall portions bounding the ports 2, 5 could engage to hold the conduit against movement.
A light trap in the conduit is composed of two identical semi-cylindrical shell sections 12 and 13 which are installed in the conduit in mirror-reversed relationship and contact one another with their edge faces (here in a longitudinal plane). Together, the semi-cylindrical walls 12a, 13a of the shell sections 12, 13 form a cylindrical wall having an outer diameter which is equal to the minor diameter of conduit 8 (or at most slightly greater than the same). Each shell section 12, 13 is provided (preferably of one piece by e.g., injection molding) with one or more projections 14 and 15; these extend into radial holes 10, 11 of conduit 8 to prevent any shifting or other displacement of the shell sections relative to the conduit.
Each shell section wall 12a, 13a is further provided with inwardly extending baffles 16. These extend substantially normal with reference to the path of travel in which the photographic material 17 advances through the light trap from container C1 to container C2. In the illustrated embodiment each of the shell sections has four of these baffles 16; the baffles of each shell section form with the baffles of the other shell section respective pairs of baffles which subdivide the interior of the light trap into three longitudinally adjacent compartments. There could, of course, be more than four baffles 16 in each shell section, to obtain a corresponding larger number of compartments. It is also possible to use only three baffles per shell section (thus obtaining two compartments); a smaller number is not advisable, however, because the light trap would then not fully fulfill its intended purpose.
The successive baffles 16 may be spaced lengthwise of the light trap by non-uniform (unequal) distances or, as illustrated, they may be equidistantly spaced. Their shape is best shown in FIG. 2 from which it will be evident that the inner (facing) edges of each pair of upper and lower baffles 16 abut one another at the lateral sides, i.e., transversely spaced from the photographic material 17. The center parts of these inner facing edges may be parallel to one another and recessed from the lateral sides, or they may be arcuate in the illustrated manner to define (instead of a rectangular slot) a generally elliptical slot 18 of small height. The illustrated configuration of the slot 18 is particularly advantageous (but a rectangular or still other shape is possible) because the height of the slot tapers towards the lateral sides so that, if the material 17 shifts laterally (e.g., because of guidance difficulties) only its edges will contact the baffles 16 at the inclined portions of the inner edge faces; these portions then tend to deflect the material 17 back to the illustrated center position so that damage (scratching) to the emulsion on the material 17 is avoided.
The inner surfaces of the walls 12a, 13a must be dark and matte (not shiny) to eliminate the reflections as much as possible. The same is true of the surfaces of baffles 16. This can be obtained by applying a suitable paint or coating, unless the material of the walls 12a, 13a and the baffles 16 itself has the desired characteristic.
Since the material 17 travels in each container in a treating bath, some of the bath liquid will adhere to it as it enters the light trap. Enough liquid would eventually accumulate in the compartments to fill the same, which is evidently undesirable. Also, there is the danger that the treating liquid would be taken along into the next container (here the container C2) and contaminate the bath in the same. To avoid this, the lower shell section 13 is provided at or near the lowest point of each compartment with one or more holes 19. A collecting channel 20 is provided at the outer side of section 13 (e.g., formed of one piece with it) and communicates with all of the holes 19; it also is open to the upstream container (here C1) so that the liquid is returned to the bath in the same.
The shell-sections 12, 13 are advantageously also made of an elastically deformable material (e.g., natural or synthetic rubber or synthetic plastic); this may be the same material from which the conduit 8 is made. The use of such elastically deformable material permits elastic deformation of the shell-sections 12, 13 for the purpose of inserting them into or removing them from the conduit 8. Shell-sections 12, 13 may each be of one piece with their baffles 16, e.g., by being made via injection molding.
Whenever the cover (3 or 6) of one of the containers (C1, C2) is removed, the light will enter the container from above. Any of this light which enters through the first slot 18 of the light trap (on its way to the other container which is not uncovered) will be reflected into the nearest (first) compartment by the material 17 and absorbed therein. Light which enters the uncovered container under a very flat angle relative to the plane of material 17, is reflected into the second and third compartment and thereby absorbed. Only that component of incoming light which enters in (or substantially in) the same plane as material 17, might travel through the light trap into the other container. In view of the construction of the containers, including the fact that light can enter only from above when the cover is removed, this component of light is so small, however, that it is negligible and poses no problems.
Thus, the invention provides a light trap which prevents substantially all light from entering one container from another container, which avoids damaging of the photographic material, and which allows the photographic material to pass through it in a straight-line path and thus avoids separation of the joints where segments of the photographic material are connected to one another.
While the invention has been illustrated and described as embodied in a developing apparatus, 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. | A developing apparatus for photographic material has at least two containers for treating baths. These are so arranged that the photographic material travels through them in succession. A light trap connects the containers and the photographic material issuing from the upstream containers travels in a straight-line path through the light trap to reach the downstream container. | 6 |
TECHNICAL FIELD
[0001] The present invention relates generally to a method of creating a three-dimensional woven textile fabric, and more particularly to a method of applying hydraulic energy in conjunction with a three-dimensional image transfer device, whereby a specific and desirable pattern defined by the image transfer device is durably imparted into the pre-colored fibrous component of the woven fabric.
BACKGROUND OF THE INVENTION
[0002] Woven textile fabrics, of which include a plurality of interwoven warp and weft yarns, are used for all manner of applications, including apparel, home furnishings, recreational products, and industrial applications. Because of the expense associated with spinning of yarns, and weaving of textile fabrics, techniques have been developed for manufacture of nonwoven fabrics from fibrous or filamentary materials. Typically, manufacture of nonwoven fabrics entails creating a web or batt of fibrous or filamentary material, and treating the web in a manner to provide the resultant fabric with the desired physical properties.
[0003] One manner of making nonwoven fabrics, which has met with widespread commercial success, involves hydraulically treating the fabric with high-pressure liquid (water) streams, which act to entangle and integrate the fibrous material. Such hydroentangling techniques are disclosed in U.S. Pat. No. 3,485,706, to Evans, hereby incorporated by reference.
[0004] More recently, hydroentangling techniques have been developed for manufacture of nonwoven fabrics whereby patterning and imaging of the fabric can be affected as the fabric is hydraulically formed on a three-dimensional image transfer device. U.S. Pat. No. 5,098,764, U.S. Pat. No. 5,244,711, U.S. Pat. No. 5,822,823, and U.S. Pat. No. 5,827,597, the disclosures of which are hereby expressly incorporated by reference, relate to the use of such three-dimensional image transfer devices. Use of these types of devices permits greatly enhanced versatility in the production of hydroentangled nonwoven fabrics.
[0005] Recognizing the efficient means by which three-dimensional patterns can be achieved through manufacture of nonwoven fabrics by hydroentanglement, efforts have been made to treat woven textile fabrics hydraulically in order to form images and patterns therein.
[0006] U.S. Pat. No. 4,967,456 and U.S. Pat. No. 4,995,151, hereby incorporated by reference, disclose techniques for hydro-enhancing and hydro-patterning fabric. Practice of the hydro-enhancing and hydro-patterning techniques requires the use of a mesh screen. The mesh screen is embossed with the desired three-dimensional pattern, which is then used as the foraminous surface against which woven fabrics are treated with hydraulic energy. The use of mesh screens, however, has an inherent and deleterious flaw which precludes the acceptable treatment on continuous yardages of woven material. In order to form a mesh screen to be used to treat continuous yardage of material, the screen must be linked at its terminal edges, thus forming a loop or belt. Where the terminal ends of the mesh screen meet to for the loop, there are a plurality of wire ends that must be adjoined. A seam is formed across the length of the formed loop, a seam that becomes part of the overall three-dimensional pattern and creates a repeating defect in the course of treatment of continuous yardage.
[0007] The present invention contemplates a method of applying hydraulic energy in conjunction with a three-dimensional image transfer device, whereby a specific and desirable pattern defined by the image transfer device is durably imparted to the woven fabric. The use of a three-dimensional image transfer device is necessary to facilitate the efficient and commercially viable use of the method.
[0008] It has been found that the use of an image transfer device allows for the controlled expression of the fibrous content of the warp and weft yarns (referred to as “blooming”) comprising a woven textile fabric. When these warp and weft yarns comprise variations in coloration, hue, luster, or intensity, unique aesthetic results are obtained. Such aesthetic results are most visually striking when the image transfer device used has a pronounced variation in the three-dimensional foraminous surfaces.
SUMMARY OF THE INVENTION
[0009] The present method of imaging a woven textile fabric having a plurality of interwoven warp and weft yarns, preferably comprising contrasting fibers, contemplates that a three-dimensional image transfer device be provided. The image transfer device has a foraminous, image-forming surface comprising a regular or irregular pattern of three-dimensional surface elements.
[0010] The woven textile fabric is positioned on the image transfer device, and hydraulic imaging of the fabric effected by subjecting the fabric to pressurized liquid streams applied to a surface of the fabric facing away from the image transfer device. By the action of the high-pressure liquid stream, the regular pattern defined by the image-forming surface of the image transfer device is imparted to the woven fabric. The pattern imparted to the fabric may include both an image which results from rearrangement and displacement of the fabric yarns, which can impart a three-dimensionality to the fabric, as well as patterning which results from differential blooming of the fabric yarns which corresponds to the pattern of the image transfer device.
[0011] The present method has been practiced for imparting an image to woven fabrics comprising aesthetically contrasting fibrous components. As will be appreciated, the technique can be employed for imparting an image to a wide variety of textile fabrics. Standard, low cost textile products can be transformed into high value, three-dimensional fabrics suitable for many apparel, home furnishing, upholstery, and other applications. A fabric which is otherwise substantially uniform in appearance can be provided with an aesthetically pleasing pattern, reflecting the three-dimensionality of the fabric and/or color variations therein.
BRIEF DESCRIPTION OF THE DRAWINGS
[0012] [0012]FIG. 1 is a diagrammatic view of an apparatus for imaging a woven textile fabric embodying the principles of the present invention;
[0013] [0013]FIG. 2 is a diagrammatic view of the image-forming surface of a three-dimensional image transfer device of the apparatus shown in FIG. 1, referred to as “small squares”;
[0014] [0014]FIG. 3 is a diagrammatic view of the image-forming surface of a three-dimensional image transfer device of the apparatus shown in FIG. 1, referred to as “small diamonds”;
[0015] [0015]FIG. 4 is a photograph of a woven material prior to imaging on a three-dimensional image transfer device taken with a top-light;
[0016] [0016]FIG. 5 is a microphotograph of the woven material as in FIG. 4 at a magnification level of approximately 12× taken with a top-light;
[0017] [0017]FIG. 6 is a photograph of a woven material after imaging on a three-dimensional image transfer device depicted in FIG. 2 taken with a top-light;
[0018] [0018]FIG. 7 is a microphotograph of the woven material as in FIG. 6 at a magnification level of approximately 12× taken with a top-light;
[0019] [0019]FIG. 8 is a photograph of a woven material prior to imaging on a three-dimensional image transfer device depicted in FIG. 3 taken with a top-light;
[0020] [0020]FIG. 9 is a microphotograph of the woven material as in FIG. 8 at a magnification level of approximately 12× taken with a top-light;
[0021] [0021]FIG. 10 is a microphotograph of the reverse side of the woven material as in FIG. 8 at a magnification level of approximately 12× taken with a top-light;
[0022] [0022]FIG. 11 is a microphotograph of the woven material as in FIG. 4 at a magnification level of approximately 12× taken with a back-light; and
[0023] [0023]FIG. 12 is a microphotograph of the woven material as in FIG. 8 at a magnification level of approximately 12× taken with a back-light.
DETAILED DESCRIPTION
[0024] While the present invention is susceptible of embodiment in various forms, there is shown in the figures, and will hereinafter be described a presently preferred embodiment of the invention, with the understanding that the present disclosure is to be considered as an exemplification of the invention, and is not intended to limit the invention to the specific embodiment illustrated.
[0025] The present invention contemplates patterning and imaging of woven textile fabrics, comprising a plurality of interwoven warp and weft yarns comprising aesthetically contrasting fibrous components. Positioning of such a woven fabric on the image-forming surface of a three-dimensional image transfer device in conjunction with hydraulic treatment of the fabric desirably acts to efficiently impart an image defined by the image transfer device to the fabric. Under the influence of high-pressure liquid (water) streams, hydraulic treatment of the woven fabric results in displacement of the interwoven yarns so that the fabric is patterned in a fashion corresponding to the pattern defined by the image transfer device. Additionally, imaging of the fabric can be effected as a result of the controlled blooming of the fibrous component of the yarns under the influence of the high-pressure liquid streams, thus enhancing the three-dimensional imaging which can be created and providing a pattern of color differentiation which can, in itself, be desirable.
[0026] The woven three-dimensional fabrics of the present invention are suitable for various applications, including, but not limited to apparel, home furnishing, and upholstery. Suitable apparel applications include bottom weights, such as pants or shorts. Home furnishing applications wherein the three-dimensionally imaged woven fabric can be utilized include draperies, slip-covers, and wall coverings. Furthermore, the fabric may be used in upholstery applications, such as backing fabric.
[0027] [0027]FIG. 1 illustrates an apparatus for hydraulically treating woven textile fabrics in accordance with the present invention. The apparatus includes a pre-wetting station 10 at which a precursor woven textile fabric F is positioned for pre-wetting. A pre-wetting manifold may be operated at a pressure on the order of 100 psi to thereby effect pre-wetting of the woven textile fabric F.
[0028] The apparatus illustrated in FIG. 1 further includes an imaging an patterning drum 14 comprising a three-dimensional image transfer device for effecting imaging and patterning of the woven textile fabric. The image transfer device includes a movable imaging surface defining a regular or irregular pattern which moves relative to a plurality of entangling manifolds 16 which act in cooperation with three-dimensional elements defined by the imaging surface of the image transfer device to effect imaging and patterning of the woven textile fabric.
[0029] The woven textile fabric is advanced onto the image transfer device so that the fabric is positioned on the image-forming surface of the device. The fabric is moved together with the imaging surface relative to the manifolds 16 so that high-pressure liquid streams are directed against the surface of the fabric which faces away from the image-forming surface of the image transfer device.
[0030] In current practice of the present invention, three manifolds 16 have been employed, each comprising a single row of orifices each having a diameter of 0.005 inches, with orifices spaced at 50 per inch. Line speeds on the order of 45 feet per minute have been employed, though commercial line speed can be increased significantly, with one stack of drying cans 18 provided operating at approximately 350° F. The manifolds can be operated across a broad range of pressures, 1000 to 4700 psi, with current examples of woven textile fabrics being hydraulically preferably treated with pressures ranging from 2800 to 4700 psi, and most preferably with pressures on the order of 4000 psi.
[0031] [0031]FIG. 2 illustrates the image-forming surface of an image transfer device having a “small squares” image pattern. FIG. 3 illustrates a so-called “small diamonds” pattern of the forming surface of the image transfer device.
[0032] Fabrics formed in accordance with the present method exhibited aesthetic properties as set forth in FIGS. 4 through 10. FIGS. 4 and 5 depict a representative starting substrate comprising a 100% polyester woven fabric of contrasting dark colored warp yarns and light colored weft yarns in a stagger fill pattern. FIGS. 6 and 7 depict the starting woven substrate after processing in accordance with the present invention utilizing a “small squares” image transfer device. FIGS. 8 and 9 depict the starting woven substrate after processing in accordance with the present invention utilizing a “small diamonds” image transfer device.
[0033] With reference to FIG. 9, two simultaneous effects of employing an image transfer device are particularly noted. Lighter colored weft yarns can be seen to have regions of both high compaction 80 , and high distention 90 . Further, the difference in blooming of the fibrous content of the weft yarns can be seen to be greater in the high distention region 90 as compared to the weft yarns found in the regions of high warp compaction 100 .
[0034] It is believed that the controlled redistribution and blooming of the composite yarns is uniquely bound to the foraminous surface of the image transfer device. The foraminous surface of the image transfer device comprises a compound structure of asperities and voids in multiple planes. As the hydraulic energy impacts upon the fabric juxtaposed upon the foraminous surface, deflection of the energy from the surface asperities, compounded by the vectoring of the force due to drainage patterns, allows the image transfer device to create variably compacted regions. Further, the surface asperities can act to constrain blooming of the same yarns such that variable presentation of the fibrous yarn components are expressed.
[0035] From the foregoing, numerous modifications and variations can be effected without departing from the true spirit and scope of the novel concept of the present invention. It is to be understood that no limitation with respect to the specific embodiment illustrated herein is intended or should be inferred. The disclosure is intended to cover, by the appended claims, all such modifications as fall within the scope of the claims. | A process of making a protective composite wrap, which exhibits the ability to protect metallic objects from corrosion environments, wherein a first thermoplastic resin and a vapor corrosion inhibitor are blended into a homogenous blend, wherein the homogenous blend is extruded into continuous thermoplastic filaments, which are collected into a nonwoven fabric, wherein a second thermoplastic resin is extruded into a continuous thin film, and wherein the nonwoven fabric and the thin film are affixed into a face to face juxtaposition to form the protective composite wrap. | 3 |
BACKGROUND OF THE INVENTION
1. Technical Field
The present invention relates in general to load operations by processors in a multiprocessor system and in particular to load operations which utilize data received prior to a coherency response window.
2. Description of the Related Art
Most contemporary high-performance data processing system architectures include multiple levels of cache memory within the storage hierarchy. Caches are employed in data processing systems to provide faster access to frequently used data over access times associated with system memory, thereby improving overall performance. Cache levels are typically employed in progressively larger sizes with a trade off to progressively longer access latencies. Smaller, faster caches are employed at levels within the storage hierarchy closer to the processor or processors, while larger, slower caches are employed at levels closer to system memory.
In multiprocessor systems, bus operations initiated by one processing segment—a processor and any in-line caches between the processor and the shared bus—are typically snooped by other processing segments for coherency purposes, to preserve data integrity within cache segments shared among the various processing segments. In such systems, a processor initiating a load operation may be required to wait for a coherency response window—for responses from other devices snooping the load operation—to validate data received in response to the load request.
In known processors, such as the PowerPC™ 620 and 630FP available from International Business Machines Corporation of Armonk, N.Y., the coherency response window is programmable from two bus cycles to as many as sixteen bus cycles. A timing diagram for a processor employing an eight cycle coherency response window or Time Latency to Address Response (TLAR) is depicted in FIG. 4 . Such larger TLARs may be required for slow bus devices or bridges which need to get information from down stream.
Processors utilizing a snoopy bus may receive data before the coherency response window and hold the data, for example, in a buffered read queue or a bus interface unit, until the coherency response window. However, the processor may not use the buffered data due to possible invalidation in the coherency response window. Thus, the processor load operation is limited by the latency associated with the coherency response window. Processors receiving data concurrently with the coherency response window, on the other hand, eliminate the buffering but still incur the latency associated with the coherency response window.
Where only one or two cache levels are implemented in a data processing system, the latency associated with a coherency response window for a load operation may be acceptable since a longer latency may be required to source the requested data from system memory or a bridge device. The frequency of occasions when an L2 cache hits but the processor must wait for the coherency response window may, as a result of the L2 cache's small size, be too low to be a significant performance concern. Where more cache levels are implemented, however, such as an L3 cache, circumstances may change. A larger L3 cache should result in more cache hits, where requested data could be sent to the processor prior to the coherency response window. However, current architectures do not permit the data to be utilized by the processor prior to the TLAR.
It would be desirable, therefore, to provide a mechanism allowing data received by a processor to be used by the requesting processor prior to the coherency response is window.
SUMMARY OF THE INVENTION
It is therefore one object of the present invention to improve load operations by processors in a multiprocessor system.
It is another object of the present invention to allow load operations to complete prior to a coherency response window.
It is yet another object of the present invention to allow a processor to utilize data received prior to a coherency response window.
The foregoing objects are achieved as is now described. Where a null response can be expected from devices snooping a load operation, data may be used by a requesting processor prior to the coherency response window. A null snoop response may be determined, for example, from the availability of the data without a bus transaction. The capability of accelerating data in this fashion requires only a few simple changes in processor state transitions, required to permit entry of the data completion wait state prior to the response wait state. Processors may forward accelerated data to execution units with the expectation that a null snoop response will be received during the coherency response window. If a non-null snoop response is received, an error condition is asserted. Data acceleration of the type described allows critical data to get back to the processor without waiting for the coherency response window.
The above as well as additional objects, features, and advantages of the present invention will become apparent in the following detailed written description.
BRIEF DESCRIPTION OF THE DRAWINGS
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 objects 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:
FIG. 1 depicts a block diagram of a multiprocessor system in which a preferred embodiment of the present invention may be implemented; and
FIG. 2 is a timing diagram for a load operation in which the processor receives the requested data prior to a coherency response window in accordance with a preferred embodiment of the present invention;
FIG. 3 is a high level flowchart for a process of accelerating data responses in accordance with a preferred embodiment of the present invention; and
FIG. 4 is a timing diagram for a load operation in accordance with the known art.
DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENT
With reference now to the figures, and in particular with reference to FIG. 1 , a block diagram of a multi-processor system in which a preferred embodiment of the present invention may be implemented is depicted. Multi-processing system 102 includes processors 104 and 106 , which preferably conform to the specifications of the PowerPC™ family of processors. Each processor 104 and 106 includes an on-chip L1 cache 108 and 110 , respectively, and in-line L2 and L3 caches 112 and 114 , respectively, and 116 and 118 , respectively. L2 caches 112 and 114 and L3 caches 116 and 118 connect the respective processors 102 and 104 to system bus 120 . For each processing segment, the respective L1 and L2 caches are onboard with the processor in the exemplary embodiment, while the L3 cache remains in-line.
Also connected to system bus 120 in the exemplary embodiment is system memory 122 and bridge 124 coupling nonvolatile storage 126 to system bus 120 . Those skilled in the art will recognize that multiprocessor system 102 may also include other components not shown such as a keyboard, mouse or other input devices, a display, a network interface card, etc. Such variations are within the spirit and scope of the present invention.
Multiprocessor system 102 in the exemplary embodiment includes a coherency protocol such as the MESI protocol or a variant. The modified (M) coherency state indicates that only one cache has the valid copy of the data, and that copy is “dirty” or modified with respect to the copy in system memory. The exclusive (E) coherency state is defined to signify that only one cache has a valid copy of the data, which is unmodified with respect to the data in system memory. The shared (S) coherency state denotes that one or more caches have copies of the data and that no copy is modified with respect to system memory. The invalid (I) coherency state indicates that no caches have a valid copy of the data. Additional coherency states may also be implemented.
In the exemplary embodiment, processors 104 and 106 may receive data requested by a load operation before the coherency response window. This data may be utilized by the processor, including forwarding the data to the execution units, provided the tag for the requested cache segment indicates that a null response will be received from snooping devices. To safely utilize data prior to the coherency response window, the processor must determine that no other processor or horizontal cache has a copy of the requested data in the modified, exclusive, or shared coherency state (i.e. the requested data is in the exclusive state within the storage device sourcing the data in response to the request) and that the snooped operation will therefore not be retried. This is accomplished utilizing a null response from the bus.
In the exemplary embodiment of FIG. 1 , because the L2 cache is on board with the processor, it need not wait for the coherency response to begin sourcing the data because it does not utilize the bus. The L3 cache is accessed through the bus, requiring the coherency window wait.
Referring now to FIG. 2 , a timing diagram for a load operation in which the processor receives the requested data prior to a coherency response window in accordance with a preferred embodiment of the present invention is illustrated. As may be seen, the requested data is sourced to the processor several cycles before the coherency response window, only two bus cycles after the address for the subject load operation is placed on the address bus. A null response is received in the coherency response window, as expected.
The capability of utilizing received data prior to a coherency response window requires only a few simple differences in state transitions to implement. Extra transitions are required for the ability to enter the data completion wait state prior to the response wait state. These differences are apparent from Tables I and II.
TABLE I Current State Next State Explanation Address Start Response Window The address is on the Wait bus; awaiting a response. Response Window Wait Data Completion Response received Wait concurrent with data; if data is verified as good, the data wait state must be entered until all data is received. Data Completion Wait Idle All data has been received.
Table I illustrates the state transitions required for a load operation in accordance with the known art, without data acceleration as described herein. Only four states are necessary, and the transitions sequence through the states with only one possible “Next State” for each “Current State.”
TABLE II Current State Next State Explanation Address Start Data Completion Data arrived before Wait the response window. Address Start Response Window Data arrives Wait concurrent with or after response window Data Completion Wait Idle All data and the response have been received. Data Completion Wait Response Window All data has been Wait received, but the response has not. Response Window Wait Data Completion Response has been Wait received concurrent with the data. If the data is deter- mined to be good, the data wait state must be entered until all data is received.
Table II illustrates the state transitions required for a load operation in accordance with the present invention, with data acceleration as described herein. Additional state transitions are required due to the possibility of the data arriving before the response. Three possible alternatives are necessary: data arriving before the response; data arriving with the response; and the response arriving during the data transfer. The state transitions in Table II accommodate all three alternatives.
With reference now to FIG. 3 , a high level flowchart for a process of utilizing accelerating data responses in accordance with a preferred embodiment of the present invention is depicted. The process is implemented within a processor receiving data from a lower level cache in the storage hierarchy. The process begins at step 302 which depicts initiation of a load operation initiated by the processor.
The process next passes to step 304 , which illustrates a determination of whether the data has been received. If not, the process passes to step 306 , which illustrates a determination of whether the coherency response window has been reached. This may occur when the data arrives concurrent with or after the coherency response window. If the coherency response window has not been reached, the process returns to step 304 . If the coherency response window has been reached, however, the process proceeds instead to step 308 , which depicts awaiting the arrival of the requested data, and then passed to step 310 , which illustrates the process becoming idle until another load operation is initiated.
Referring back to step 304 , if the requested data is received by the processor, the process proceeds instead to step 312 , which depicts a determination of whether the coherency response window has been reached. This may occur when the data arrives concurrent with the coherency response window. In that event, the process proceeds to step 308 , described above.
From step 314 , the process proceeds instead to step 318 , which illustrates using the received data if it is good (i.e., based on parity or ECC checking) and awaiting the coherency response. The data may-be forwarded to execution units within the processor as operands. The process then passes to step 320 , which depicts a determination of whether the response received during the coherency response window was null. If so, the process proceeds to step 310 , described earlier. If not, however, the process proceeds instead to step 322 , which depicts asserting an error condition, and then to step 310 . The error condition must be asserted to prevent damage to the data integrity where another processor has a copy of the data. However, this occurrence should be so infrequent as to be far outweighed by the performance increase achieved by utilizing accelerated data prior to the coherency snoop response window. In fact, the system should essentially guarantee that data will not be sent early without the null bus response, with the error checking implemented as a failsafe.
The present invention allows critical data to be sourced to a processor and utilized by the processor (returned to the execution units) prior to the coherency response window for snooping devices within the system. The data is used prior to the coherency response window if a null snoop response is expected, such as where the data is sourced by a cache having an exclusive copy of the data. If a non-null snoop response is subsequently received in the coherency response window, an error condition is asserted. The performance increase resulting from utilizing data without waiting for the coherency response window-outweighs the likely impact of any errors resulting from non-null snoop responses.
While the invention has been particularly shown and described with reference to a preferred embodiment, it will be understood by those skilled in the art that various changes in form and detail may be made therein without departing from the spirit and scope of the invention. | Where a null response can be expected from devices snooping a load operation, data may be used by a requesting processor prior to the coherency response window. A null snoop response may be determined, for example, from the availability of the data without a bus transaction. The capability of accelerating data in this fashion requires only a few simple changes in processor state transitions, required to permit entry of the data completion wait state prior to the response wait state. Processors may forward accelerated data to execution units with the expectation that a null snoop response will be received during the coherency response window. If a non-null snoop response is received, an error condition is asserted. Data acceleration of the type described allows critical data to get back to the processor without waiting for the coherency response window. | 6 |
CROSS-REFERENCE TO RELATED PATENT APPLICATIONS
[0001] This patent application claims priority from and is related to U.S. Provisional Patent Application Ser. No. 61/129,311, filed 18 Jun. 2008, this U.S. Provisional Patent Application incorporated by reference in its entirety herein.
FIELD OF INVENTION
[0002] The invention relates generally to spur, helical or worm gearboxes, and more particularly, to such gearboxes in which the backlash between the gears is eliminated by spring force.
BACKGROUND OF INVENTION
[0003] In the field of drive systems, there exist many types of gear arrangements: helical, spur, bevel, worm and other types.
[0004] The driving and driven shafts vary from parallel to vertical arrangements.
[0005] Properly functioning mechanical systems need to have a certain clearance/backlash (gap, play) between the components transmitting motion under load.
[0006] Clearance is necessary to avoid interference, wear and excessive heat generation, insure proper lubrication, compensate for manufacturing tolerances etc. Clearance in the gear mesh means that the gap between the teeth of one gear is by a small amount larger than the tooth width of the mating gear.
[0007] In some applications, especially at low speeds, where high accuracy is needed, for example, in closed loop tracking applications, zero or minimal backlash will enable better functioning of the system. There are many patents for mechanism that reduces or eliminates backlash in various types of gears.
SUMMARY OF INVENTION
[0008] The primary object of the present invention is to overcome the drawbacks caused with other “rigid” or non-flexible solutions of backlash elimination between spur, helical, worm types of gear, especially for low speed, tracking or positioning applications.
[0009] This object is achieved by using a spring loaded mechanism that tightens the meshing gear surfaces, thus eliminating the backlash between them. Another object of this invention is to create a repeatable, rotational positioning stage, with virtually zero backlash.
[0010] The present invention relates to a backlash eliminating mechanism, comprising a housing with a base portion that acts as a support structure. The present invention is a simple, reliable and low-cost solution, applicable especially for low-speed systems.
[0011] At the same time, the system has automatic compensation for wear of materials, hence re-adjustment is automatically achieved.
BRIEF DESCRIPTION OF THE DRAWINGS
[0012] For a better understanding of the invention and to show how the same may be carried into effect, reference will now be made, purely by way of example, to the accompanying drawings.
[0013] With specific reference now to the drawings in detail, it is stressed that the particulars shown are by way of example and for purposes of illustrative discussion of the preferred embodiments of the present invention only, and are presented in the cause of providing what is believed to be the most useful and readily understood description of the principles and conceptual aspects of the invention. In this regard, no attempt is made to show structural details of the invention in more detail than is necessary for a fundamental understanding of the invention, the description taken with the drawings making apparent to those skilled in the art how the several forms of the invention may be embodied in practice. In the accompanying drawings:
[0014] FIGS. 1A and 1B show a schematic construction of the worm gearbox internal parts of the invention, illustrating the backlash elimination mechanism applied to the driving element; and
[0015] FIGS. 2A and 2B show a schematic construction of the spur (or helical) gearbox internal parts of the invention, illustrating the backlash elimination mechanism applied to the driving element.
DETAILED DESCRIPTION OF PREFERRED EMBODIMENTS
[0016] The present invention provides a drive system used particularly (but not only) in low-speed tracking or positioning systems or applications.
[0017] For Worm Sear Systems:
[0018] FIGS. 1A and 1B depict a first embodiment of the present system for backlash elimination.
[0019] The system includes a driving (input) element ( 100 ) that is a worm pinion assembled on a shaft ( 105 ), or a combined wormshaft ( 100 + 105 ).
[0020] A driven element ( 110 ), a worm gear, rotates inside housing ( 115 ), around shaft ( 120 ), fixed in the housing by bearings ( 125 ).
[0021] The pinion ( 100 ) is usually a low speed element, a motor or a gear motor, or any other rotating element.
[0022] A compression spring ( 125 a ) or an extension spring ( 125 b ) (or other types of springs that cause similar effect) is fixed to the housing ( 115 ) on one end and connected to the shaft ( 105 ) through sliding (or other type) of bearing ( 145 ), or even directly wrapped around the shaft ( 105 ) with the ability to slide on it, tightening the pinion ( 100 ) and gear flanks ( 130 ) towards each other, thus eliminating the natural backlash of a normal worm gear set. The springs can be fixed or adjustable.
[0023] The shaft ( 105 ) is fixed to the internal part of a spherical (or other type) bearing ( 135 ), and is rotatable around its axis, but at the same time can have a small degree of freedom around the bearing center ( 140 ), to allow the backlash closing effect.
[0024] As a result, the backlash between driving element ( 100 ) and driven element ( 110 ) is eliminated ( FIG. 1B ).
[0025] The motor or gear motor that rotates shaft ( 105 ) must be rigidly mounted on shaft ( 105 ), or otherwise connected through a flexible element to shaft ( 105 ).
[0026] For Spur or Helical Gear System:
[0027] FIGS. 2A and 2B depict a second embodiment of the present system for backlash elimination.
[0028] The system includes a driving (input) element ( 200 ) that is a spur or helical gear (pinion) assembled on a shaft ( 205 ), or a combined gear+shaft ( 200 + 205 ). The driving element ( 200 ) rotates around shaft ( 205 ) by sliding or any type of bearings ( 245 ).
[0029] A driven element ( 210 ), a spur or helical gear, rotates inside a housing ( 215 ), around shaft ( 220 ) that is held by bearings ( 250 ).
[0030] The pinion ( 200 ) is usually a low speed element driven by a low speed motor or gearmotor, or any other rotating element.
[0031] A lever ( 225 ) carries the shaft ( 205 ) and is rotatable around the axis of shaft ( 230 ) through sliding (or other) bearing ( 255 ), enabling the lever ( 225 ) a small rotation angle around the axis of shaft ( 230 ).
[0032] A compression spring ( 235 a ) or an extension spring ( 235 b ) (or a torsion spring connected to shaft ( 230 ), that causes a similar effect) tightens the gears towards each other, thus eliminating the natural backlash of a regular spur or helical gear set. The springs can be fixed or adjustable.
[0033] The spring ( 235 a or 235 b ), extension or compression of any other type, is connected at one end to the housing ( 215 ) and on the other side to the lever ( 225 ).
[0034] In an alternative embodiment, shaft ( 230 ) may be rigidly connected to the lever ( 225 ), in which case the lever ( 225 ) acts as a tension spring and the spring ( 235 a or 235 b ) are not needed.
[0035] As a result, the backlash between driving element ( 200 ) and driven element ( 210 ) is eliminated ( FIG. 2B ).
[0036] The motor or gearmotor that rotates pinion ( 200 ) must be rigidly mounted on shaft ( 205 ), or otherwise connected through a flexible element to shaft ( 205 ).
[0037] The springs, in all the embodiments described above, may be at fixed preloaded, push or pull type, but also with an option of adjusting the push or pull force by changing the preloads, (for example, changeable tensioning or compressing the springs).
[0038] The invention may be embodied in other specific forms without departing from the spirit or essential characteristics thereof. The present embodiments are therefore to be considered in all respects as illustrative and not as restrictive, the scope of the invention being indicated by the appended claims rather than by the foregoing description, and all changes which come within the meaning and range of equivalency of the claims are therefore intended to be embraced therein.
[0039] The system according to the present invention has the additional advantage of automatically compensating for wear of materials, which has the effect of increasing the backlash effect in standard systems. | A zero backlash mechanism for a worm, spur or helical gears, using a spring loaded mechanism that tightens the meshing gear surfaces, thus eliminating the backlash between them. | 5 |
CROSS-REFERENCES TO RELATED APPLICATIONS
[0001] This application claims priority under 35 U.S.C. § 119 (e) to, and hereby incorporates by reference, U.S. Provisional Application No. 60/688,356, filed Jun. 6, 2005, and under 35 U.S.C. § 120 to, and hereby incorporates by reference, U.S. Design Application Nos. 29/231,516, filed Jun. 6, 2005, 29/231,615, filed Jun. 6, 2005, and 29/231,711, filed Jun. 7, 2005.
BACKGROUND OF THE INVENTION
[0002] 1. Field of the Invention
[0003] This invention relates to devices for securing displays and, in particular, this invention relates to devices for securing flat panel displays to surfaces, such as walls.
[0004] 2. Background
[0005] Flat panel displays, including plasma-screen television displays, are increasingly present. These displays are sufficiently thin to be mounted conveniently on walls in a manner similar to conventionally framed objects, such as photographs and pictures. Various mounting systems for flat panel displays have been proposed to secure the flat panel displays to a mounting device, the mounting device with its own panel attaching to the back of the flat panel display.
[0006] Using mounted devices having a generally solid panel attached to the flat panel display, as in prior devices, is often inconvenient, in part because the solid mounting panel impedes access to the rear of the flat panel display. Access to the rear of the flat panel display is often necessary during installation thereof due to the need to attach and/or access wires, cords, and other interfaces at the back of the display. Indeed, the presence of a generally solid panel on the mounting device creates an impediment to manipulating these wires, cords, and interfaces, especially when the flat panel display is attached to the mounting panel. Further, the solid mounting panel reduces the available space between the back of the flat panel display and the adjacent wall to which the flat panel display is attached, thus making it difficult to store wires and cords directly behind the flat panel display, where the wires and cords can be conveniently kept out of sight, as seen from the front of the flat panel display.
[0007] Additionally, the wall engaging portion of the prior display mounting devices is typically a substantially solid, rigid and flat panel. Panels of this nature require any in-wall wiring to exit above, below, or to the side of the panel. Alternatively, the panel must be cut to provide a relief for routing wiring. The construction of the wall to which the mounting device is to be attached and wiring locations within the wall, however, may effectively dictate the wall exit location for the wiring, thereby making it more difficult to provide an exit location, which is concealed behind the flat panel electronic display device as may be desirable for aesthetic reasons. On the other hand, cutting a relief into the mounting panel may weaken the panel structurally and may, itself, be unsightly.
[0008] Moreover, flat panel electronic displays, particularly plasma displays, may weigh more than one hundred pounds, thereby causing a significant moment force to be exerted on the wall at the points of attachment. When mounted in public areas, the displays may be subject to contact, further causing an even greater load on the wall and wall structure. One drawback with the prior art of mounting devices for flat panel displays is that these mounting devices typically attach to the wall construction along a relatively narrow horizontal band, thereby concentrating the load in a small area of the wall. The result of attaching these mounting devices along a relatively narrow horizontal band on a wall is that of sometimes overloading and failure of the wall construction or mount, thereby causing damage to the electronic display and possibly injury to persons nearby.
[0009] There is thus a need in the industry for a mounting device addressing the aforementioned drawbacks by enabling improved access for cable routing and by providing improved load distribution on the structure supporting the flat panel electronic display and mount.
SUMMARY OF THE INVENTION
[0010] This invention substantially meets the aforementioned needs of the industry by providing a flat panel display device enabling improved wiring access and structural load distribution. According to one embodiment of the invention, the mounting device includes a plurality of elongate members coupled in a frame and defining an open interior space. The vertical elongate members confronting the wall surface may have at least one portion set away from the wall surface to facilitate routing of conductors, such as cables and wires, between the vertical elongate members and the wall. These setback portions may be generally concave in some embodiments.
[0011] The open interior space defined by the separate elements may enable wiring the exit from the wall at virtually any desired location behind the flat panel electronic display, thereby enhancing concealment of the exit location of the conductors and obviating any need for cutting apertures into the mounting structure. Additionally, elimination of material in the instant structure, as compared to a solid plate, enables a generally lighter and stronger mounting device. The elongate members themselves may be provided with a plurality of apertures to enable a variety of fastener locations, thereby offering greater flexibility in the location to which the instant device is to be mounted.
[0012] The spaced-apart location of the elongate members enables the structural load imparted by the flat panel electronic display to be spread over a larger portion of the wall surface, thereby inducing less stress on the wall components. Spread loading of the structural load enables relatively greater loading to be imposed on the mount before wall system failure or damage occurs.
[0013] A latch mechanism retaining the flat panel display to the frame is also provided. Alternative embodiments of the invention may include tilt mechanisms for positioning the flat panel display at various viewing angles.
[0014] It is therefore an object of this invention to provide a display mounting assembly mountable to a surface and including a frame and a securing device. The frame may have at least one keyhole and a plurality of attachment openings for securing the frame to the surface. Each of the keyholes may have a first portion and a second portion, the second portion opening into the first portion. The first portion may be characterized by a first portion horizontal dimension and the second portion may be characterized by a second portion horizontal dimension, the first portion horizontal dimension being greater than the second portion horizontal dimension. The attachment openings may be positioned outboard each of the keyholes. The securing device may be proximate one of the at least one keyhole and may pivot between an open position and a closed position.
[0015] It is therefore another object of this invention to provide a display mounting assembly for attaching a device to the surface and including a frame and a securing device. The frame may be attachable to the surface and may define a plurality of keyholes, each of the keyholes having a first portion opening into a second portion. The first and second portions may each be characterized by a generally horizontal dimension, the first portion horizontal dimension being greater than the second portion horizontal dimension. The first portion may admit a fastener and the second portion may retain the admitted fastener. The securing device may be pivotally attached to the frame proximate one of the keyholes and may further secure the fastener when the fastener is disposed in the keyholes second portion.
[0016] It is therefore yet another object of this invention to provide a display mounting device comprising a frame and a securing device. The frame may include a plurality of horizontal frame elements and a plurality of vertical frame elements. Each of the vertical frame elements may have a keyhole and each of the keyholes may further include a first portion, characterized by a first portion horizontal dimension, and a second portion, characterized by a second portion horizontal dimension smaller than the first portion horizontal dimension. The securing device may define a cutout and may be movable between an open position and a closed position, the closed position positioning the securing device over the keyholes second portion.
[0017] It is therefore still another object of this invention to provide a method of manufacturing a display mounting device, the method including forming a frame attachable to a surface. The frame may include a plurality of keyholes and at least one securing device. Each of the plurality of keyholes may have an access portion with a maximum horizontal dimension and a notch. The notch may open into the access portion and may have a smaller horizontal dimension than the maximum horizontal dimension of the access portion. The at least one securing device may pivotally be secured to the frame proximate one of the plurality of keyholes. The formed frame may comprise a plurality of horizontal frame elements attached to a plurality of vertical frame elements. The plurality of keyholes and securing device may be disposed on at least one of the plurality of vertical frame elements. Forming the frame may also include attaching a plurality of horizontal frame elements to a plurality of vertical frame elements; and attaching a plurality of pivot arms to the horizontal frame elements or to the vertical frame elements. The plurality of pivot arms may include the plurality of keyholes, the securing device pivotally attached to one of the pivot arms. Forming the frame may yet further include attaching a pivot linkage element between each of the plurality of pivot arms and the vertical frame elements. Forming the frame may still yet further include attaching a plurality of pivot linkage elements between each of the plurality of pivot arms and the vertical frame elements. The frame may be formed such that the pivot arms are simultaneously pivoted and longitudinally translated. The frame may be additionally formed such that the pivot arms may be simultaneously pivoted and displaced away from the horizontal frame elements and the vertical frame elements.
[0018] These and other objects, features, and advantages of this invention will become apparent from the description which follows, when considered in view of the accompanying drawings.
BRIEF DESCRIPTION OF THE DRAWINGS
[0019] FIG. 1 is a perspective view of an embodiment of a mounting device of this invention.
[0020] FIG. 2 is a rear view of the mounting device of FIG. 1 .
[0021] FIG. 3 a is a front view of the mounting device of FIG. 1 .
[0022] FIG. 3 b is a fragmentary plan view of one embodiment of the instant securing assembly.
[0023] FIG. 4 is an end view of the mounting device of FIG. 1 .
[0024] FIG. 5 is a perspective view of another embodiment of the mounting device of this invention.
[0025] FIG. 6 is a front view of the mounting device of FIG. 5 .
[0026] FIG. 7 is a rear view of the mounting device of FIG. 5 .
[0027] FIG. 8 is an end view of the mounting device of FIG. 5 .
[0028] FIG. 9 is a perspective view of another embodiment of the mounting device of this invention.
[0029] FIG. 10 is a front view of the mounting device of FIG. 9 .
[0030] FIG. 11 is a rear view of the mounting device of FIG. 9 .
[0031] FIG. 12 is an end view of the mounting device of FIG. 9 .
[0032] FIG. 13 is a side view of the mounting device of FIG. 15 in an open position.
[0033] FIG. 14 is a side view of the mounting device of FIG. 15 in a closed position.
[0034] FIG. 15 is a perspective view of another embodiment of the mounting device of this invention.
[0035] FIG. 16 is a rear view of the mounting device of FIG. 15 .
[0036] FIG. 17 is a perspective view of another embodiment of the mounting device of this invention.
[0037] FIG. 18 is a front view of the mounting device of FIG. 17 .
[0038] FIG. 19 is a rear view of the mounting device of FIG. 17 .
[0039] FIG. 20 is an end view of the mounting device of FIG. 17 .
[0040] FIG. 21 is a side view of the mounting device of FIG. 17 in a closed position.
[0041] FIG. 22 is a side view of the mounting device of FIG. 17 in an open position.
[0042] FIG. 23 is a perspective view of another embodiment of the mounting device of this invention.
[0043] FIG. 24 is a rear view of the mounting device of FIG. 23 .
[0044] FIG. 25 is a front view of the mounting device of FIG. 23 .
[0045] FIG. 26 is a side view of the mounting device of FIG. 23 being translated from an open position to a closed position.
[0046] FIG. 27 is a side view of the mounting device of FIG. 23 in an open position.
[0047] It is understood that the above-described figures are only illustrative of the present invention and are not contemplated to limit the scope thereof.
DETAILED DESCRIPTION
[0048] Unless otherwise defined, all technical and scientific terms used herein have the same meaning as commonly understood by one of ordinary skill in the art to which this invention belongs. Although methods and materials similar or equivalent to those described herein can be used to practice the invention, suitable methods and materials are described below. In case of conflict, the present specification, including definitions, will control. In addition, the materials, methods, and examples are illustrative only and not intended to be limiting.
[0049] Any references to such relative terms as front and back, horizontal and vertical, or the like, are intended for convenience of description and are not intended to limit the present invention or its components to any specific positional or spatial orientation. All dimensions of the components in the attached figures may vary with a potential design and the intended use of an embodiment of the invention without departing from the scope of the invention.
[0050] Each of the features and methods disclosed herein may be utilized separately or in conjunction with other features and methods to provide improved devices of this invention and methods for making and using the same. Thus, a person of ordinary skill in the art will readily appreciate that individual components shown on various embodiments of the present invention are interchangeable without undue experimentation and may be added or interchanged on other embodiments without departing from the spirit and scope of this invention. Representative examples of the teachings of the present invention, which examples utilize many of these additional features and methods in conjunction, will now be described in detail with reference to the drawings. This detailed description is merely intended to teach a person of skill in the art further details for practicing preferred aspects of the present teachings and is not intended to limit the scope of the invention. Therefore, specific combinations of features and methods disclosed in the following detailed description may not be necessary to practice the invention in the broadest sense, and are instead taught merely to particularly describe representative embodiments of the invention.
[0051] One embodiment of the panel display mounting device of this invention is depicted in FIGS. 1-4 generally at 100 and includes a frame 102 and a securing assembly 104 . The frame 102 , in turn, has respective first and second vertical frame elements 110 and 112 and first and second horizontal frame elements 114 and 116 . Each of the vertical elements 110 and 112 includes a main portion 118 and tab elements 120 . The tab elements 120 extend generally laterally from each end of the main portion 118 and define tab apertures 122 therein. The vertical elements 110 and 112 are secured to the horizontal elements 114 and 116 by means of connectors such as threaded shanks 124 . In the embodiment shown, the threaded shanks 124 are attached to the horizontal elements 114 and 116 , e.g., by press fitting, welding, or the like, and are disposed thereon so as to be accommodated by the tab apertures 122 . The vertical frame elements 110 and 112 are secured in place by nuts 126 , or other equivalent means. In lieu of the threaded shanks 124 and nuts 126 , a person of ordinary skill in the art will readily recognize that other connectors, such as rivets, welds, or machine screws would be suitable for other embodiments of this invention. The vertical frame element main portions 118 may define respective first and second apertures 128 and 130 and a plurality of keyholes 132 disposed proximate the ends thereof. The apertures 128 are depicted as being generally circular and the apertures 130 are shown as generally diamond-shaped. However, a person of ordinary skill in the art will readily recognize that other shapes, e.g. oval, hexagonal, and the like, may be suitable for other embodiments of this invention. The keyholes 132 have an access portion 134 opening into a notch 136 . The keyholes 132 may be advantageously utilized with fastening buttons (not shown) attached to items to be mounted therewith, such as a flat panel displays. The keyholes 132 and fastening buttons are disclosed and described in U.S. patent application Ser. No. 10/821,395, hereby incorporated by reference in its entirety. Sides 138 and 140 extend from each of the main portions 118 so as to present a generally U-shaped cross-section. The sides 138 and 140 are generally arcuate in the embodiment depicted, arching upwardly from the ends of the vertical elements 110 and 112 . The arcuate shape of the sides 138 and 140 advantageously provide a cutaway portion to enable wires, cables, and the like to be routed between the vertical frame elements 110 and 112 and a surface to which the device of this invention is mounted. While a single cutout is defined by the sides 138 and 140 , a person of ordinary skill in the art will readily recognize that the sides 138 and 140 can be configured to define multiple cutouts if desired.
[0052] The first and second horizontal frame elements 114 and 116 include generally orthogonal main portions 142 and peripheral lips 144 . The main portions 142 define at least one, e.g., five, generally central apertures 146 and a plurality of slots 148 . In the embodiment depicted, the slots 148 are generally outboard with respect to the vertical frame elements 110 and 112 . The slots 148 , along with the apertures 146 , are used to mount the instant device to a structural component, such as a wall, by accommodating fasteners such as anchors or lag bolts therein. The horizontal frame elements of this invention are dimensioned so that the slots 148 are spaced apart so as to enable the structural load imposed by flat panel displays to be spread over larger portions of wall surfaces or the like, thereby inducing less stress in these structural components and an enabling relatively greater loading to be imposed on the mount before wall system damage or failure occurs.
[0053] The securing assembly 104 depicted includes a securing element 154 , which has a handle portion 156 and defines a cutaway 158 . The securing element 154 is pivotally attached to the first vertical element 110 by means of a connector, such as a bolt 160 , the bolt 160 secured in place by a nut 162 . Alternatively, other connectors, such as rivets or the like, can be used in other embodiments. Fastening buttons as described in U.S. patent application Ser. No. 10/821,395 are further secured in the notches 136 of the keyholes 132 by pivoting the instant securing element 154 from the open position depicted in FIG. 3 to a closed and secured position depicted in FIG. 4 and is depicted by the arrow 164 in FIG. 3 b . While the securing element of this invention is shown as attached only to the first vertical frame element 110 , a person of ordinary skill in the art will readily recognize that the instant securing element could be attached to the second vertical frame element 112 as well.
[0054] Another embodiment of the mounting device of this invention is shown in FIGS. 5-8 at 200 , wherein substantially similar elements to those shown in FIGS. 1-4 and described above are identified by identical numerals. The mounting device 200 includes a frame 202 and a securing assembly, such as the securing assembly 104 , with the features and advantages as described above with respect to the mounting device 100 . The frame 202 may have respective first and second vertical frame elements 210 and 212 and first and second horizontal frame elements 214 and 216 . The first and second vertical frame elements in the embodiment depicted each have a main portion 218 and tab elements 220 extending generally laterally from each end thereof. Each of the tab elements 220 defines a tab aperture 222 . The vertical frame elements 210 and 212 are secured to the horizontal frame elements 214 and 216 by connectors such as threaded shanks 124 and nuts 126 or equivalent connectors, as described above. In the embodiment depicted, each vertical frame element main portion 218 defines a first aperture 228 and at least one, e.g., three, second aperture 230 . In the embodiment depicted the first aperture 228 is generally circular and the second apertures 230 are circular or diamond-shaped. However, a person of ordinary skill in the art will readily recognize that other shapes, e.g., square, hexagonal, may be present as desired. Sides 238 and 240 extend generally orthogonally from each main element 218 in this embodiment. The sides 238 and 240 are generally and advantageously arcuate as described above with respect to the first and second vertical frame elements 110 and 112 . Additionally, the vertical frame elements of this embodiment may have the same variations in features and the same, or similar, advantages as discussed above with respect to the first and second vertical frame elements 110 , 112 .
[0055] The first and second horizontal frame elements 214 and 216 each have a main portion 242 and a peripheral lip 244 . Each main portion 242 defines at least one aperture 246 and a plurality, e.g. six, slots 248 . In the embodiment shown the aperture 246 is generally triangular; however, a person of ordinary skill in the art will readily recognize that other shapes, e.g., circular, square, hexagonal, may be present as well. The slots 248 are disposed outboard the aperture 246 . The apertures and slots of these and other embodiments in the instant horizontal frame elements are dimensioned and disposed to attach the mounting device 200 to a structural surface, such as a wall, in the manner, and with the advantages, discussed above with respect to the mounting device 100 .
[0056] Referring to FIGS. 9-12 , yet another embodiment of the mounting device of this invention is shown generally at 300 and includes a frame 302 and a securing assembly, such as indicated, and with the advantages discussed, above with respect to the securing assembly 104 . Certain aspects of the frame 302 and other frames disclosed herein are disclosed and described in U.S. Pat. No. 6,402,109, issued 11 Jun. 2002, hereby incorporated by reference. The frame 302 includes respective first and second vertical frame elements 310 and 312 , first and second horizontal frame elements 314 and 316 , and a pivoting assembly 318 . In the embodiment shown, the vertical frame elements 310 and 312 are mirror images of each other, characterized by respective first ends 322 and 324 , second ends 326 and 328 and having respective front portions 330 and 332 generally orthogonally joining outboard portions 334 and 336 and inboard edges 338 and 340 . The inboard edges 338 and 340 impart a generally concave shape to the front portions 330 and 332 . Consequently, the front portions 330 and 332 taper from maximum widths at their front ends 322 and 324 to minimum widths proximate the midpoints thereof. Apertures 342 are defined proximate the first ends 322 and 324 and the second ends 326 and 328 of the front portions 330 and 332 . Connectors, such as the threaded shanks 124 and nuts 126 may be disposed on the horizontal frame elements 314 and 316 as discussed above with respect to the mounting device 100 and alternative means of affixing the vertical frame elements 310 and 312 to the horizontal frame elements 314 and 316 , as also discussed above with respect to the mounting device 100 , may also be employed.
[0057] The outboard portions 334 and 336 may be characterized by respective first ends 344 and 346 and second ends 348 and 350 . Proximate the first ends 344 and 346 , and proceeding toward the second ends 348 and 350 , are respective curved slots 352 , first apertures 356 , second apertures 360 , generally linear slots 364 , and third apertures 368 . Peripheral cutouts 372 are disposed between the first apertures 356 and the second apertures 360 .
[0058] The first and second horizontal frame elements 314 and 318 are mirror images of each other in the embodiment depicted and may include a main element 375 and a peripheral lip 376 extending generally orthogonally from the main element 375 . The main element 375 may define at least one, e.g., five, generally central apertures 377 and a plurality of slots 378 disposed outboard the apertures 377 . A person of ordinary skill in the art will readily recognize that the apertures, while depicted as being circular, can be made in a variety of shapes as discussed above. The utility and locations of the slots 378 may be similar, or substantially the same as, the slots 148 discussed above with respect to the mounting device 100 .
[0059] The pivoting assembly 318 has respective first and second pivot arms 380 and 382 , pivot link elements 384 , spacer/friction elements 386 , and spacer/friction elements 387 . A pivot linkage element 384 links the first and second pivot arms 380 and 382 to the first and second vertical frame elements 310 and 312 . The first and second pivot arms 380 and 382 may be characterized by respective first ends 388 and 390 and second ends 390 and 392 , a spacer 386 being operably positioned between the second ends 390 and 392 of the first and second pivot arms 380 and 382 and the outboard portions 334 and 336 of the first and second vertical elements 310 and 312 .
[0060] The first and second pivot arms 380 and 382 may include rear portions 396 and 398 and outboard portions 400 and 402 extending generally orthogonally from the rear portions 396 and 398 . The rear portions 396 and 398 further define first apertures 404 and second apertures 406 . A plurality of keyholes such as those indicated at 132 may also be defined in the rear portions 396 and 398 and are depicted in the figures as being disposed proximate the first end 388 and 390 and the second ends 392 and 394 . The keyholes 132 and their features and advantages are discussed above with respect to the mounting device 100 . A securing assembly such as that indicated at 104 and discussed above with respect to the mounting device 100 may be pivotally mounted to one or both of the rear portions 386 and 388 using one or both of the apertures 404 . Slots 408 and 410 are defined in the respective outboard portions 400 and 402 proximate first ends 412 (first end 412 not shown) and 414 thereof and apertures 416 and 418 (not shown) are defined proximate second ends 420 and 422 (not shown) thereof.
[0061] Each of the pivot linkage elements 384 may define a generally curved slot 430 proximate one end thereof and an aperture 432 (not shown) disposed proximate the other end thereof.
[0062] The spacers (or friction washers) 386 may be made from such suitable materials is ultra-high molecular weight polyethylene (UHMWPE) or ultra-high density polyethylene (UHDPE). However, a person of ordinary skill in the art will readily comprehend that the instant spacers may be made from other materials, such as wood or other synthetic resins, such as disclosed and described in the Handbook of Plastics, Elastomers, and Composites, Third Edition, Charles A. Harper, Editor in Chief, McGraw-Hill (1996), hereby incorporated by reference.
[0063] The pivoting assembly 318 is assembled connecting the first and second pivot arms 380 and 382 to the first and second vertical frame elements 310 and 312 . Assembly is accomplished by first securing a connector, such as a nut and bolt or rivet, through the second apertures 360 and 362 of the outboard portions 334 and 336 and the apertures 432 of the pivot linkage elements 384 , friction elements 387 being disposed between the outboard portions 400 and 402 and the pivot linkage elements 384 and between the pivot linkage elements 384 and the connector, to thereby establish pivot points 434 and 436 (pivot point 436 not shown). Second securing a connector, such as a nut and bolt or rivet, through the curved slots 430 of the pivot linkage elements 384 and the apertures 416 and 418 of the outboard portions 400 and 402 ; and third by securing a connector, such as a nut and bolt or rivet, through the third apertures 368 and 370 of the outboard portions 334 and 336 , the spacers 386 , and the apertures 416 and 418 of the outboard portions 400 and 402 to establish pivot points 438 and 440 (pivot point 440 not shown).
[0064] Referring to FIGS. 9, 13 and 14 , the pivot arms 380 and 382 of the assembled pivoting assembly 318 are pivoted away from, and toward, the remainder of the mounting device 300 at the pivot points 438 and 440 as indicated by the arrow 442 . As the pivot arms 380 and 382 are pivoted, the pivot linkage elements 384 are pivoted at pivot points 434 and 436 as the connectors slide within the curved slot 430 of the pivot linkage elements 384 . Resistance to pivoting is imparted by the friction elements 386 and 387 . This resistance tends to maintain the pivot arms 380 and 382 at positions intermediate between those depicted in FIGS. 13 and 14 . Resistance to pivoting also imparts the tendency to maintain pivot arms of other embodiments of this invention when other friction elements are present.
[0065] Yet another embodiment of the mounting device of this invention is shown in FIGS. 13-16 generally at 500 . The mounting device 500 includes a frame 502 and a securing assembly such as that indicated at 104 and discussed above with respect to the mounting device 100 . The frame 502 includes first and second vertical frame elements 310 and 312 , first and second horizontal frame elements 514 and 516 , and a pivoting assembly 518 . The horizontal frame elements 514 and 516 each have a main portion 575 and a peripheral lip 576 , differing from the horizontal frame elements 314 and 316 by defining a generally central aperture 377 and a plurality of slots 378 disposed generally outboard the aperture 377 . While the aperture is shown as being generally triangular, apertures of other shapes may be used in other embodiments as discussed above. The plurality of slots are advantageous for mounting the mounting device 500 on surfaces in situations where it is desirable to fasten the device at several places on the surface, the slots allowing connectors to be extended into structural members, such as vertical studs. The pivoting assembly 518 may include the components described above with respect to the mounting device 300 , but with first and second pivot arms 580 and 582 in place of the first and second pivot arms 380 and 382 . The pivot arms 580 and 582 differ from the pivot arms 380 and 382 by defining at least one, e.g., two, apertures 584 . In this embodiment, the handle portion 156 (not shown) of the securing element 154 has one or more apertures (not shown) aligning with the apertures 584 when the securing element 154 is in the closed position. Thus, the securing element 154 can be further secured in the closed position by securing a connector, such as a nut and bolt or a rivet, though the aligned apertures or securing a hasp of a lock through the aligned apertures.
[0066] Another embodiment of the instant mounting device is shown in FIGS. 17-22 and is indicated generally at 600 . In the embodiment depicted, the mounting device 600 includes a frame 602 and may include a securing assembly, such as the securing assembly 104 discussed above with respect to the mounting device 100 . The frame 602 , in turn, may include respective first and second vertical frame elements 610 and 612 , first and second horizontal frame elements 614 and 616 , and a pivoting assembly 618 .
[0067] The first and second vertical frame elements 610 and 612 may be characterized as having respective first ends 622 and 624 and second ends 626 and 628 . Each of the vertical frame elements 610 and 612 has respective front portions 630 and 632 and outboard portions 634 and 636 extending generally orthogonally from the front portions 630 and 632 . Generally arcuate inboard edges 638 and 640 are opposite the respective outboard portions 634 and 636 on the respective front portions 630 and 632 . In the embodiment shown, the front portions 630 and 632 taper from maximum widths at first ends 622 and 624 and at second ends 626 and 628 to minimum widths at their mid-points therebetween. Apertures 642 are defined in the front portions 630 and 632 proximate the first and second ends thereof and apertures 644 are defined generally centrally therein. The apertures 642 are disposed and dimensioned to accept connectors, such as threaded shanks extending from the first and second horizontal frame elements 614 in 616 . The first and second frame elements 610 and 612 may be secured to the first and second horizontal frame elements 614 and 616 by nuts threaded on the connectors. A person of ordinary skill in the art will readily comprehend alternate structure, e.g., rivets, welds, and the like, to affix the instant vertical frame elements to the instant horizontal frame elements. Each of the outboard portions 634 and 636 , beginning proximate the first ends thereof, define generally curved slots 646 , first apertures 648 , generally linear slots 650 , and second apertures 652 . The first and second horizontal frame elements 614 and 616 , being mirror images in the embodiment shown, have main portions 654 and a peripheral lip 656 extending generally orthogonally from each main portion 654 . The main portions 654 , in turn, define generally central apertures 658 and slots 660 . The slots 660 are disposed proximate each end of the main portions 654 in the embodiment shown.
[0068] The pivot assembly 618 may include respective first and second pivot arms 666 and 668 and, in mechanical communication with each pivot arm, respective first and second pivot linkage elements 670 and 672 and respective first, second, and a pair of third spacer/friction elements 674 , 676 , and 678 . The pivot arms 666 and 668 may be characterized by respective first ends 680 and 682 , second ends 684 and 686 , and have respective rear portions 688 and 690 and outboard portions 692 and 694 extending generally orthogonally from the rear portions 668 and 690 , respectively. The rear portions 688 and 690 , in turn, define respective first and second apertures 696 and 698 and may have keyholes 132 defined proximate each of the first and second ends thereof. Securing structures, such as described above with respect to the securing assembly 104 , may be operably affixed to the rear portions 688 and 690 by securing connectors through the first apertures 696 . In the embodiment shown, the second apertures 698 are defined generally centrally on the rear portions 688 and 690 . The keyholes 132 are discussed above with respect to the mounting device 100 . The outboard portions 692 and 694 are generally mirror images of each other and define respective first, second, and third apertures 702 , 704 (not shown), and 706 , slots 708 , and cutouts 710 . Generally round first and second apertures 702 and 704 are defined proximate the first and second ends of the outboard portions 682 and 694 . The third apertures 706 are generally square in the embodiment shown.
[0069] The generally elongated first pivot linkage element 670 defines a pair of first apertures (not shown) proximate each end thereof, as well as a second aperture (not shown) positioned between the first apertures. The second pivot linkage element 672 is also generally elongate with a pair of apertures disposed proximate each end thereof.
[0070] When the pivoting assembly 618 is assembled, the first and second pivot arms 666 and 668 may be pivoted independently and are longitudinally displaced as they are pivoted away from the horizontal and vertical frame elements. The first and second pivot arms 666 and 668 are initially connected to a first pivot linkage element 670 to establish a first connection 712 by securing a connector through the pivot arm slot 708 and one of the first apertures in the first pivot linkage element 670 , a second spacer or friction element 676 being disposed between the pivot arm and the first pivot linkage element. A connector is then secured through the second (middle) aperture of the first pivot linkage element 670 and one of the apertures of the second pivot linkage element 672 to establish a second connection 714 , a second space or/friction element 676 disposed therebetween. The first pivot linkage element 670 is then connected to the outboard portions 692 and 694 of the first and second pivot arms to establish a third connection 716 by securing a connector through the other first aperture of the first pivot linkage element 670 and the first aperture 648 in the outboard portions 634 and 636 , a first spacer 674 being disposed therebetween. Assembly is then completed by establishing a fourth connection 718 by securing a connector through the other aperture in the second pivot linkage element 672 , the slot 650 of the outboard portions 634 , 636 and the second aperture 704 of the outboard portions 682 and 694 of the linkage arms, a spacer 678 being present between the second pivot linkage element 672 and the outboard portion 634 and 636 and between the outboard portions 634 and 636 of the vertical frame elements and the outboard portions 692 and 694 of the pivot arms, respectively.
[0071] As the pivot arms of this embodiment are displaced away from the frame elements in the direction indicated by the arrow 720 , the present pivot arms are also simultaneously longitudinally displaced. Stated otherwise, the linkage arms are pivoted from the closed position of FIG. 21 to the open position of FIG. 22 . Simultaneously pivoting away from the frame elements and longitudinal displacement occurs when the first connection 712 is displaced toward the first ends of the pivot arms as the pivot arms are displaced away from the frame elements in the direction of the arrow 722 , the first pivot linkage element 670 thereby pivoting on the third connection 716 . When the first pivot linkage element 670 is thusly pivoted, the first second connection 714 longitudinally displaces the second pivot linkage element 672 in the direction of the arrow 724 . The second pivot linkage element 672 is also simultaneously pivoted at the fourth connection 718 in the direction of the arrow 726 . The fourth connection 718 is simultaneously displaced longitudinally in the slot 650 , which longitudinally translates the pivot arm.
[0072] Referring to FIGS. 23-27 , yet another embodiment of the mounting device of this invention is shown at 800 . The mounting device 800 broadly includes a frame 802 and a securing assembly such as discussed above with respect to the mounting device 100 and indicated at 104 .
[0073] The frame 802 , in turn, has respective first and second vertical frame elements 810 and 812 , first and second horizontal frame elements 814 and 816 , and a pivoting assembly 818 . The generally concave-shaped first and second vertical frame elements 810 and 812 are generally mirror images of each other and, consequently, may be characterized as having respective first ends 822 and 824 and second ends 826 and 828 , and have front portions 830 and 832 and outboard portions 834 and 836 extending generally orthogonally from the front portions 830 and 832 . The inboard edges 838 and 840 of the respective front portions 830 and 832 are generally arcuate, thereby providing maximum widths proximate the first ends 822 and 824 and the second ends 826 and 828 and providing minimum widths proximate the longitudinal midpoints of the vertical frame elements 810 and 812 . Apertures 842 are defined proximate the first ends 822 and 824 and proximate the second ends 826 and 828 . The apertures 842 are disposed and dimensioned to accommodate connectors extending from the first and second horizontal frame elements 814 and 816 . In one embodiment, the connectors include threaded shanks and the vertical frame elements are affixed to the horizontal frame elements by threading nuts on the connectors. While threaded shanks and nuts are disclosed herein, connectors such as rivets, welds, and the like, may be suitable for other embodiments of this invention.
[0074] The first and second horizontal frame elements 814 and 816 are mirror images of each other, each having a main portion 844 and a peripheral lip 846 extending generally orthogonally from the main portion 844 . Each main portion 844 defines a generally triangular, central aperture 848 ; however, apertures of other shapes, e.g., circular, hexagonal, or the like, may be suitable for other embodiments. Each main portion 844 further defines a plurality of slots 850 extending generally longitudinally along the main portions 844 .
[0075] Referring to the outboard portions 834 and 836 , a curved slot is defined therein proximate the second ends 826 and 828 and a plurality, e.g., three, generally linear and longitudinally oriented slots 854 are present as well.
[0076] The pivoting assembly 818 has respective first and second pivot arms 860 and 862 . Associated with each pivot arm are first second and third pivot linkage elements 864 , 866 , and 868 . An optional pivot arm connecting element 870 may also be present. Additionally, the first, second, and third spacer/friction elements 674 , 676 , and 678 discussed and described above may be present.
[0077] The pivot arms 860 and 862 may be characterized as having first ends 874 and 876 and second ends 878 and 880 and may include respective rear portions 882 and 884 and outboard portions 886 and 888 extending generally orthogonally from the rear portions 882 and 884 , respectively. The rear portions 882 and 884 , in turn, may each define a first aperture 890 and a plurality of second apertures 892 . A securing assembly, such as discussed above with respect to mounting device 100 and designated at 104 , may be mounted via one or both of the first apertures 890 . One of the second apertures 894 is generally triangular and the other aperture 894 is generally circular; however, a person of ordinary skill in the art will readily recognize that other shapes, e.g., square, diamond-shaped, hexagonal, or the like, may be suitable in other embodiments. Additionally, a keyhole, such as the keyhole 132 discussed above with respect to the mounting device 100 , may be present proximate one or more of the first ends 874 , 876 and second ends 878 , 880 .
[0078] Each of the outboard portions 886 and 888 may define respective first and second apertures 894 and 896 , a slot 898 , a third aperture 900 (not shown), and a cutout 902 . The cut at 902 may impart a generally tapered appearance to the pivot arms 860 and 862 when viewed from the side. In the embodiment depicted, a pair of first apertures 890 is defined proximate each of the first ends 874 and 876 . The second aperture 896 is positioned proximate the cutout 902 . The slot 898 extends generally longitudinally proximate the cutout 902 . The third aperture 900 is positioned proximate each of the second ends 878 and 880
[0079] The first pivot linkage element 864 defines a pair of first apertures 906 (not shown) and a second aperture 908 (not shown). The first apertures 906 are positioned proximate each end of the pivot linkage element 864 . The second aperture 908 is positioned proximate one edge of the pivot linkage element 864 and in a position longitudinally intermediate the first apertures 906 . The generally elongate second pivot linkage element 866 and third pivot linkage element 868 have an aperture proximate each end thereof. The pivot arm connecting element 870 has a first member 912 and a pair of second members 914 , which are mirror images of each other in this embodiment. The second members 914 extend generally orthogonally from each end of the first member 912 and define an aperture (not shown) therein.
[0080] The instant pivoting assembly 818 is operably assembled by establishing a series of pivoting connections as described herein below. A first connection 918 is effected by securing a connector through one of the first apertures 906 of the first pivot linkage element 864 and through the slot 898 of the pivot arms 860 , 862 , a first spacer/friction element 674 optionally being disposed therebetween. A second connection 920 is established by securing a connector through the other of the first apertures 906 of the first pivot linkage element 864 and through each of the curved slots 852 of the outboard portions 834 , 836 , a first spacer/friction element 674 optionally being disposed therebetween. A third connection 922 is made by securing a connector in the second aperture 908 of the first pivot linkage element 864 and one of the apertures in the third pivot linkage element 868 . A fourth connection 924 is effected by extending and securing a connector in the other aperture of the third pivot linkage element 868 , a slot 854 of each outboard portion 834 , 836 , and one of the apertures present in the third pivot linkage element 868 . A fifth connection 926 occurs when a connector is secured in the other aperture of the third pivot linkage element 868 , the third aperture 900 in the outboard portions 886 , 888 , and the aperture of each of the second members 914 of the pivot arm connecting element 870 . While the pivoting assembly 818 can be efficiently assembled by establishing the connections in the order as described above, the person of ordinary skill in the art will readily recognize that other iterations may be suitable as well. When installed thusly, the pivot arm connecting element 870 itself pivots between a closed position as depicted in FIG. 26 and indicated by the arrow 928 and an open position depicted in FIG. 27 .
[0081] Functionally, the pivot arms 860 , 862 may be pivoted away from the frame elements from a closed position to a first pivoted position wherein the first ends 874 , 876 thereof are forced away from the frame elements while the second ends 878 , 880 thereof remain positioned proximate the frame elements. As the pivot arms 860 , 862 are pivoted away from the frame elements the first connection 918 is displaced longitudinally in the slot 898 in the direction indicated by the arrow 928 , thereby pivoting the first pivot linkage element 864 away from the frame elements and in the direction indicated by the arrow 930 . The pivoting first pivot linkage element 864 , via the third connection 922 , then simultaneously pivots and longitudinally displaces the second pivot linkage element 866 in the directions indicated by the arrows 932 and 934 , respectively. From the first pivoted position, the pivot arms 860 , 862 may be translated to a second pivoted position depicted in FIG. 27 . In doing so the pivot arm second ends 878 , 880 are forced away from the frame elements, simultaneously pivoting the third pivot linkage element 868 at the third and fourth connections 922 , 924 .
[0082] The instant pivoting assembly 818 , when assembled, simultaneously translates the pivot arms 860 and 862 longitudinally and away from the frame members.
[0083] Because numerous modifications of this invention may be made without departing from the spirit thereof, the scope of the invention is not to be limited to the embodiments illustrated and described. Rather, the scope of the invention is to be determined by the appended claims and their equivalents. | A display mounting assembly mountable to a surface, such as a wall, and having interconnected vertical and horizontal frame elements. The frame of the display mounting assembly having keyholes for attaching displays and a securing assembly for further securing attached displays. The frame may optionally include pivot arms for adjusting the positions of attached displays. It is emphasized that this abstract is provided to comply with the rules requiring an abstract that will allow a searcher or other reader to quickly ascertain the subject matter of the technical disclosure. It is submitted with the understanding that it will not be used to interpret or limit the scope or meaning of the claims. 37 C.F.R. § 1.72(b). | 5 |
CROSS-REFERENCE TO RELATED APPLICATIONS
[0001] This patent application claims priority to EP08305202.7 filed May 27, 2008, which is incorporated herein by reference in its entirety.
BACKGROUND
[0002] 1. Field
[0003] This disclosure relates to methods, systems, and computer program products for providing a semantic analysis of electronic emails.
[0004] 2. Description of Background
[0005] Electronic mail (email) is now a common form of communication that is used on a daily basis by individuals as well as businesses. In some cases, the individuals and/or businesses receive overwhelming amounts of emails per day. Sifting through the emails to try and determine who is sending the email, why the email is being sent, or if the email relates to other emails can be tedious and time consuming.
[0006] After sifting through the emails, in some cases, it is determined that a particular sender should be blocked, for example as a spam sender. In some cases, multiple spam senders can be related. To block all of the spam senders, each spam sender must be blocked individually. This process can be tedious and time consuming.
SUMMARY
[0007] The shortcomings of the prior art are overcome and additional advantages are provided through the provision of a method for analyzing email data. The method includes: parsing a first email into one or more email attributes; searching a social network datastore that stores email attributes of other emails; retrieving history data related to one or more or the email attributes from the social network datastore; and processing the one or more email attributes and the history data based on one or more configurable rules.
[0008] System and computer program products corresponding to the above-summarized methods are also described and claimed herein.
[0009] Additional features and advantages are realized through the techniques of the present invention. Other embodiments and aspects of the invention are described in detail herein and are considered a part of the claimed invention. For a better understanding of the invention with advantages and features, refer to the description and to the drawings.
TECHNICAL EFFECTS
[0010] As a result of the summarized invention, technically we have achieved a solution which enhances an email application by providing methods, systems, and computer program products that allow an email user to query and automatically generate statistical data about e-mail content, a sender of an e-mail, a subject of an e-mail, and/or social networks associated with an email.
BRIEF DESCRIPTION OF THE DRAWINGS
[0011] The subject matter which is regarded as the invention is particularly pointed out and distinctly claimed in the claims at the conclusion of the specification. The foregoing and other objects, features, and advantages of the invention are apparent from the following detailed description taken in conjunction with the accompanying drawings in which:
[0012] FIG. 1 is a block diagram illustrating a network of computers that include a social networking system in accordance with an exemplary embodiment;
[0013] FIG. 2 is a dataflow diagram illustrating a social networking application of the social networking system in accordance with an exemplary embodiment; and
[0014] FIG. 3 is a flowchart illustrating a social networking method that can be performed by the social networking application in accordance with an exemplary embodiment.
[0015] The detailed description explains the preferred embodiments of the invention, together with advantages and features, by way of example with reference to the drawings.
DETAILED DESCRIPTION
[0016] Turning now to the drawings in greater detail, it will be seen that in FIG. 1 a social networking system 10 comprises one or more computers 12 - 18 that are communicatively coupled via a network 20 . As can be appreciated, the network 20 can be any type or combination thereof of known networks including, but not limited to, a wide area network (WAN), a local area network (LAN), a global network (e.g. Internet), a virtual private network (VPN), and an intranet. As can be appreciated, the computers 12 - 18 can include, but are not limited to, a desktop computer, a laptop, a workstation, a portable handheld device, or any combination thereof.
[0017] The one or more computers 12 - 18 include a processor (not shown) and one or more data storage devices (not shown). The processor can be any custom made or commercially available processor, a central processing unit, an auxiliary processor among several processors associated with the computer, a semiconductor based microprocessor, a macroprocessor, or generally any device for executing instructions. The one or more data storage devices can be at least one of the random access memory, read only memory, a cash, a stack, or the like which may temporarily or permanently store electronic data. The computers 12 - 18 may be associated with a display device 22 and one or more input devices 24 that may be used by a user to communicate with the computers. As can be appreciated, such input devices 24 may include, but are not limited to, a mouse, a keyboard, and a touchpad.
[0018] According to an exemplary embodiment, one or more of the computers 12 - 18 includes an email social network application 26 that communicates electronic data to and/or from a social network datastore 28 . In various embodiments, the social network datastore 28 is a central datastore that is located on one of the computers 12 - 18 or remotely from the all of the computers. In various other embodiments, the social network datastore 28 includes one or more sub-datastores located on each of the computers 12 - 18 that communicate user data on a peer-to-peer basis.
[0019] The email social network application 26 processes incoming emails, stores the processed email data in the social network datastore 28 , and performs one or more analyses on semantically related email data stored in the social network datastore 28 . A user communicates with the email social network application 26 and views a result of the one or more analyses via a social network interface 30 displayed on the display device 22 . In one example, the email social network application 26 is called on demand by a user inquiring about, for example, a sender, connections (e.g., subjects, topics, other users) associated with the sender, topics covered by the sender, sender history, etc.
[0020] Turning now to FIG. 2 , a dataflow diagram illustrates the email social network application 26 of FIG. 1 in accordance with an exemplary embodiment. The email social network application 26 can include one or more modules. As can be appreciated, the modules can be implemented as software, hardware, firmware and/or other suitable components that provide the described functionality. As can be appreciated, the modules shown in FIG. 2 can be combined and/or further partitioned to similarly process email data. In this example, the email social network application 26 includes a mail parser module 32 , a rules interpreter module 34 , a search engine module 36 , an engine module 38 , an index module 40 , a graphical interface module 42 , and a textual interface module 44 .
[0021] The mail parser module 32 receives as input email 46 sent to a user of the computer 12 ( FIG. 1 ) by other users (e.g., a sender). The mail parser module 32 parsers the email 46 and generates parsed data 48 based on one or more pre-defined parsing rules. The parsing rules can be generally applicable to all email applications and/or applicable to specific email applications. In one example, the parsed data 48 includes, but is not limited to, a sender user name, a sender email address, a list of CC user names, a list of CC email addresses, a subject, mail contents and/or any combination thereof. In various embodiments, the mail parser module 32 stores the parsed data 48 in the social network datastore 28 (relationship not shown). The parsed data 48 can then be used for future analysis by the same or other users.
[0022] The rules interpreter module 34 receives as input rules 50 and generates rules data 52 to define how to carryout an inquiry. In various embodiments, the rules 50 are entered by a user via the social network interface 30 ( FIG. 1 ). In one example, the rules data 52 is configured to define a total or partial analysis, a search depth, a subject analysis, a contents analysis, a CC search, a BCC search, and/or any combination thereof.
[0023] The search engine module 36 interfaces with the social network datastore 28 to retrieve relevant history data 54 for processing based on the parsed data 48 . In one example, the history data 54 includes, but is not limited to, subject, contents, name or list of names, and a connection between other emails. In various embodiments, an index module is provided to assist the search engine module in accessing the history data 54 . The index module 40 manages an indexing scheme of the social network datastore 28 . Based on the indexing scheme, the index module 40 provides an index 56 to the search engine module 36 for retrieving the relevant history data 54 .
[0024] The engine module 38 receives as input the parsed data 48 , the rules data 52 , the history data 54 , and a request 57 for social network information. Based on the inputs, the engine module 38 processes the data and generates processed data 58 . In one example, the processing module 38 processes the parsed data 48 and the history data 54 based on one or more processing methods. Such methods can include, but are not limited to, methods known in the art, such as, correlation methods, aggregation methods, knowledge tree creation methods, and statistical methods.
[0025] The graphical interface module 42 and/or the textual interface module 44 then receive the processed data 58 . Based on the processed data 58 , the graphical interface module 42 generates a graphical display data 60 that is displayed via the social network interface 30 ( FIG. 1 ). In one example, the graphical display data can include one of graphs, charts, and structures. Based on the processed data 58 , the textual interface module 44 generates textual display data 62 that is displayed via the social network interface 30 ( FIG. 1 ).
[0026] Turning now to FIG. 3 and with continued reference to FIG. 2 , a flowchart illustrates an email social network method that can be performed by the email social network application 26 of FIG. 2 in accordance with an exemplary embodiment. As can be appreciated in light of the disclosure, the order of operation within the method is not limited to the sequential execution as illustrated in FIG. 3 , but may be performed in one or more varying orders as applicable in accordance with the present disclosure.
[0027] In one example, the method may begin at 100 . As new emails 46 are received, the new emails 46 are parsed at block 102 . The parsed data 48 is temporarily or permanently stored in, for example, the social network datastore 28 at block 104 . Thereafter, requests 37 for social network information are monitored at block 106 . If a request 37 for social network information is not received, the method loops back and continues to parse new emails 46 at block 102 .
[0028] However, once the request 37 for social network information is initiated at 106 . The search criteria is defined via the rules 50 at block 108 . The social network datastore 28 is searched at block 110 . The data is processed at block 112 . Based on the processing, the processed data 58 is output at block 114 , either textually or graphically. Thereafter, the method may end at 116 .
[0029] As one example, one or more aspects of the present invention can be included in an article of manufacture (e.g., one or more computer program products) having, for instance, computer usable media. The media has embodied therein, for instance, computer readable program code means for providing and facilitating the capabilities of the present invention. The article of manufacture can be included as a part of a computer system or sold separately.
[0030] Additionally, at least one program storage device readable by a machine, tangibly embodying at least one program of instructions executable by the machine to perform the capabilities of the present invention can be provided.
[0031] The flow diagrams depicted herein are just examples. There may be many variations to these diagrams or the steps (or operations) described therein without departing from the spirit of the invention. For instance, the steps may be performed in a differing order, or steps may be added, deleted or modified. All of these variations are considered a part of the claimed invention.
[0032] While the preferred embodiment to the invention has been described, it will be understood that those skilled in the art, both now and in the future, may make various improvements and enhancements which fall within the scope of the claims which follow. These claims should be construed to maintain the proper protection for the invention first described. | A method for analyzing email data including: parsing a first email into one or more email attributes; searching a social network datastore that stores email attributes of other emails; retrieving history data related to one or more or the email attributes from the social network datastore; and processing the one or more email attributes and the history data based on one or more configurable rules. | 6 |
[0001] This application claims benefit to U.S. Provisional Application 60/776,954, filed on Feb. 28, 2006, which is herein incorporated by reference.
BACKGROUND
[0002] The invention generally relates to mine safety and more specifically to an emergency safety pod developed for the purpose of sustaining the lives of miners in case of disaster.
[0003] The mining industry is subject to distinct and inherent risk of extremely hazardous and often fatal catastrophes which may occur with little or no warning. Consequently, mining accidents account for thousands of deaths each year, particularly in developing countries. Such accidents vary widely in magnitude and origin, ranging from seismic activity, poisonous gas and ignition of flammable gas, to sudden flooding, dust explosions and collapsing shafts.
[0004] In the face of a sudden, life-threatening emergency, the unfortunate individuals closest to the danger may be unable to reach an exit of the mine or the chamber in time. Accordingly, some mines may include life-saving pods which may be installed within the mine and transported to remain within the vicinity of areas where miners plan to carry out their work. A known life protection enclosure for mines is shown in U.S. Pat. No. 4,815,363 (“the '363 patent”). The enclosure of the '363 patent, however, is lacking in several respects. For example, the '363 patent does not provide means for monitoring interior and exterior atmospheric conditions, does not include a system for maintaining a positive interior air pressure, nor does it include a equipment for aiding in locating potentially buried pods, such as a system employing a transponder or the like. A life-saving pod capable of installation and transportation within a mine, for providing protection against the aforementioned dangers and other hazards, and remedying the above listed deficiencies is desired.
SUMMARY
[0005] The underground Mine Rescue Pod (“pod”) is an emergency safety pod developed for the purpose of sustaining lives of miners in case of disaster. The pod's exterior rigid steel frame, which may for example be constructed to MSHA canopy standards, is designed to withstand a typical mine-roof fall and to protect miners against possible secondary explosions and noxious atmospheric elements. Use of fire-resistant insulation creates heat-resistant walls for the pod. The pod also has a substantially airtight interior.
[0006] The pod's interior provides an atmosphere-controlled environment, housing emergency equipment such as an oxygen generator, nourishment, and a transponder for communication between occupants of the pod and persons and/or equipment outside the pod, such as a rescue team. Additionally, the pod is equipped with both interior and exterior air quality sensors for monitoring levels of various gases inside and outside the shelter, and other air quality characteristics.
[0007] In one aspect, the invention provides a pod comprising a substantially airtight structure, including an oxygen supply system, batteries, charging equipment and equipment for monitoring the interior atmosphere of the pod.
[0008] In another aspect, the invention provides a pod comprising a substantially airtight structure, including an oxygen supply system, batteries, charging equipment and equipment for monitoring the atmosphere in the vicinity of the exterior of the pod and relaying the information to the interior of the pod.
[0009] In another aspect, the invention provides a pod comprising a substantially airtight structure, including an oxygen supply system, batteries, charging equipment and equipment for maintaining a positive air pressure within the interior atmosphere of the pod. These and other features and advantages of the invention will be more clearly understood from the following detailed description and drawings of preferred embodiments of the present invention
BRIEF DESCRIPTION OF THE DRAWINGS
[0010] FIG. 1 is a plan view of an underground mine rescue pod according to a preferred embodiment of the invention.
[0011] FIG. 2 is a front view of the pod of FIG. 1 .
[0012] FIG. 3 is a side view of the pod of FIG. 1 .
[0013] FIG. 4 is a view of detail A of FIG. 1 .
[0014] FIG. 5 is a view of detail B of FIG. 1 .
[0015] FIG. 6 is a cross-sectional elevation view of an underground mine rescue pod according to an alternate embodiment of the invention.
[0016] FIG. 7 is a cross-sectional view of a door of the pod of FIG. 6 .
[0017] FIG. 8 is a view taken along section line VIII-VIII of FIG. 9 .
[0018] FIG. 9 is a view taken along section line IX-IX of FIG. 6 .
DETAILED DESCRIPTION OF PREFERRED EMBODIMENTS
[0019] In the following detailed description, reference is made to the accompanying drawings which form a part hereof, and in which are shown by way of illustration preferred embodiments of the invention. These embodiments are described in sufficient detail to enable those skilled in the art to make and use them, and it is to be understood that structural, logical or procedural changes may be made.
[0020] Refer now to FIG. 1 , there being shown an underground mine rescue pod, generally designated by reference numeral 10 , according to a preferred embodiment of the invention. The pod 10 is generally rectangular in shape having walls 20 , including sidewalls 22 and 24 , a front wall 23 , back wall 21 , a top wall 25 ( FIG. 2 ) and a bottom wall 26 . The front wall 23 has an aperture 28 sealable by a door 30 . The pod 10 contains supplies and equipment for life support for miners or other persons in emergency situations. The equipment includes a number of non-gas-emitting type batteries 61 for providing power to the pod 10 . Suitable charging equipment 69 for charging the batteries 61 is also provided. Typically, the pod 10 will be placed at or near a substation 70 for each such unit in the mine, or where power is available. A connection 71 may be provided on the pod 10 for connecting the pod 10 through power and communications equipment 73 into available power and communication lines at the substation 70 . The charging equipment 69 is also connectable with the substation 70 .
[0021] An oxygen supply system 62 may include tanks of oxygen or one or more oxygen generators. Suitable oxygen generators could include, for example, those provided by Chembio Shelter Inc. of Allentown, Pa. Alternatively, an oxygen candle and carbon monoxide (CO) curtain (not shown) may be used in the oxygen supply system 62 . An oxygen candle is a canister that, when activated, emits oxygen as a result of a chemical reaction. A CO curtain absorbs CO and is typically flat and flexible, and may be rolled up for storage. Suitable example of oxygen candles and CO curtains are also provided by Chembio Shelter, Inc.
[0022] Also within the pod 10 are a chemical commode 63 , line communication equipment 67 , which may be telephone equipment, and a location beacon 66 , which may be, for example, a transponder. Moveable components may be placed in an interior overhead shelf 68 that may also hold food and water. In use, the location beacon 66 may emit a signal to aid searchers, rescuers or other miners in locating the pod 10 .
[0023] Along the sides of the pod are bench seats 64 . The oxygen supply system 62 and other equipment may be stored under the seats 64 . The pod 10 may be made corresponding to the dimension of the mine shaft, in a preferred embodiment. In the illustrated embodiment, the pod 10 is about sixteen feet long, about fifty inches high and about seventy-seven inches wide. This size should be able to hold about fourteen people and support them for about ninety-six hours. Alternatively, the pod 10 may be sized to shelter sixteen people for approximately 600 hours. Other sizes could be used.
[0024] An exterior air quality display 65 provides information from an exterior air quality sensor 60 regarding the atmospheric and air quality conditions outside of the pod 10 . An interior air quality sensor and display unit 72 monitors and provides information regarding the atmospheric conditions within the pod 10 . As an additional safety measure, and in particular against any cracks or faults in the integrity of the pod 10 , an air pressure system 83 may be provided, such as a valve 84 responsive to a pressure sensor 85 to release oxygen at a rate to maintain a positive air pressure within the pod 10 . In use, the positive air pressure equipment maintains a slightly higher pressure inside the pod 10 as compared with air pressure outside the pod. As such, the air pressure system 83 minimizes the risk of noxious gases that may exist exterior of the pod from seeping into the interior of the pod 10 , and further endangering the occupants.
[0025] Referring now to FIG. 2 , the door 30 is shown in greater detail. In the illustrated embodiment, the door 30 has two hinges 40 . Four lever locks 50 are provided, one at each corner of the door 30 . In a preferred embodiment, the bottom wall 26 is lined with mild steel, which may be ⅝ inch mild steel, which functions as a sled when the pod 10 is moved. A pull eye 27 ( FIG. 3 ) is provided at each bottom corner, for example, for moving the pod 10 . FIG. 3 shows a side view of the pod 10 . The top wall 25 , side walls 22 , front wall 23 and back wall 21 are made of one-inch thick mild steel plate in a preferred embodiment.
[0026] With reference to FIG. 4 , the wall construction of detail A ( FIG. 1 ) is shown. The walls in a preferred embodiment may include structural H-beams 29 having faces, and plates 54 and 56 . In a preferred embodiment, all of the walls 21 , 22 , 23 , and 25 of the pod 10 are of similar construction. The space between the plates 54 and 56 is filled with a fire resistant insulation 58 . The fire resistant insulation 58 may be blown into the space as foam and allowed to harden. In one embodiment, the H-beams 29 are four-inch H-beams that are rated 14 pounds per foot.
[0027] With reference to FIG. 5 , detail B ( FIG. 1 ) of a portion of the door 30 is described. Hinges 40 include arms 41 that extend to pivot in the eye 42 attached to the front wall 23 , preferably proximate an H-beam 29 . The locks 50 can be rotated to engage the angled catch 51 with the angle iron 52 to lock the door 30 to seal the aperture 28 . A fire resistant door gasket 53 is compressed upon the engagement of the angle iron 52 by catch 51 . The gasket 53 may be similar to gasket materials used in oven doors. In use, the locking arrangement of FIG. 5 should result in an air-tight attachment of the door 30 to the wall 23 of the pod 10 .
[0028] Refer now to FIGS. 6 through 9 , there being shown an underground mine rescue pod, generally designated by reference numeral 110 , according to an alternate embodiment of the present invention. The pod 110 has wider spacing along its walls 120 between the H-beams 129 , as compared with the pod 10 . Also, the pod 110 has a circular door that is shown in its locked position in FIG. 7 . The door 130 has a groove 132 that engages an edge of a ring 131 of the pod 110 . The door 130 also has inner protrusions 133 that provide alignment with the ring 131 . The door 130 may be hinged (not shown).
[0029] While the invention has been described in detail in connection with preferred embodiments known at the time, it should be readily understood that the invention is not limited to such disclosed embodiments. Rather, 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. | An rescue pod is disclosed having walls providing a substantially airtight interior, a transponder for communication, interior and exterior atmospheric monitoring systems. The disclosed rescue pod also has support equipment, systems for powering the equipment, and a connection for providing access to external communications and power sources. The rescue pod also comprises a positive air pressure system. | 4 |
STATEMENT REGARDING FEDERALLY SPONSORED RESEARCH OR DEVELOPMENT
[0001] Not applicable.
FIELD OF THE INVENTION
[0002] The present invention pertains to woven soil stabilization systems and methods of constructing soil stabilization systems. In particular, it pertains to soil stabilization systems comprised of soil bags interfaced with geogrid materials.
BACKGROUND OF THE INVENTION
[0003] It is known to build retaining walls, containment systems, levies and/or other similar structures using soil bags. Often, soil bags in retaining walls are not affixed to each other. Rather, gravity and friction are often relied upon to help hold soil bags in place. It is also known to use an impervious plate having a plurality of spikes protruding therefrom to hold soil bags in place, and to anchor sheets of geogrid material extending from between courses of soil bags into the fill retained by the soil bag wall. Such plate is positioned on top of a first layer of soil bags, and then a second layer of soil bags is placed thereupon. Accordingly, the spikes, which generally extend from the top and the bottom of the plate, puncture the vertically and horizontally adjacent soil bags in contact with those spikes to help hold the soil bags in place. Such plates may also have projections to protrude through holes in the geogrid sheet to anchor the soil bag wall to the reinforced soil structure.
[0004] While gravity, friction and the known plates may initially hold soil bags in place, the soil bags may shift and move over time. In particular, impervious plates serve as a barrier to water and plant growth that might otherwise drain and grow through the soil bags. For example, such plates prevent plant growth from penetrating the soil bags to help lock them into place. As such, a retaining wall structure incorporating the known plates may be prone to deteriorate more quickly. Further, such plates are not recommended for use with soil bags comprised of material that may degrade or decompose over time as the material comprising the soil bags is needed to help retain particles in the soil bags and otherwise stabilize the structure incorporating the soil bags.
[0005] Thus, there is a long felt need for an improved system that may be used to help hold soil bags in place and otherwise strengthen a retaining wall, containment system, levy and/or other similar structure. In addition, there is a need for a system with components that may be easily penetrated by roots and water to support plant growth between soil bags.
SUMMARY
[0006] The present invention provides an improved system and method for stabilizing and securing a retaining wall or similar structure, comprising an interwoven system of soil bags and geogrid weaver strips.
[0007] The present invention overcomes the aforementioned drawbacks by providing an improved system for stabilizing a retaining wall comprising soil bags.
[0008] It is one aspect of the present invention to provide an apparatus and system having a plurality of passages therethrough to facilitate the draining of water and growth of plants through and between soil bags to improve the overall strength of a retaining wall or similar structure.
[0009] It is yet another aspect of the present invention to provide a system that may be successfully used with soil bags comprising a degradable or decomposable material.
[0010] In accordance with one aspect of the invention, a system is disclosed that comprises at least one geogrid weaver strip that may be woven or twined between a plurality of soil bags to bind the soil bags together as a unit.
[0011] This Summary is neither intended nor should it be construed as being representative of the full extent and scope of the present invention. The present invention is set forth in various levels of detail in the Summary as well as in the attached drawings and the detailed description of the exemplary embodiments, and no limitation as to the scope of the present invention is intended by either the inclusion or non-inclusion of the elements, components, etc., in this Summary. Additional aspects, features and advantages of the present invention will become more readily apparent from the Detailed Description of Embodiments, particularly when taken together with the drawings.
BRIEF DESCRIPTION OF DRAWINGS
[0012] The accompanying drawings, which are incorporated in and constitute a part of the specification, illustrate embodiments of the invention and together with the general description of the invention given above and the detailed description of the drawings given below, serve to explain the principles of these inventions.
[0013] FIG. 1 is a perspective view of an exemplary embodiment of a soil stabilization system.
[0014] FIG. 2 is a perspective view of an exemplary embodiment of a soil stabilization system.
[0015] FIG. 3 is a is a plan view of an exemplary embodiment of a geogrid strip.
[0016] FIG. 4 is a perspective view of an exemplary embodiment of a soil stabilization body.
[0017] FIG. 5 is a side view of an exemplary embodiment of a soil stabilization body.
[0018] FIGS. 6( a )- 6 ( p ) illustrate various exemplary methods for constructing exemplary embodiments of a soil stabilization system.
[0019] It should be understood that the drawings are not necessarily to scale. In certain instances, details which are not necessary for understanding the invention and/or which render other details difficult to perceive may have been omitted. In some drawings, soil bags which are normally positioned closely adjacent to each other are shown in spaced relation to facilitate a description and understanding of the weaving method employed. It should be understood, of course, the invention is not necessarily limited to the particular embodiments illustrated herein.
DETAILED DESCRIPTION OF EXEMPLARY EMBODIMENTS
[0020] Referring to FIGS. 1-2 , in one embodiment the soil stabilization system 100 comprises a plurality of generally horizontally-laid courses of soil bags 120 which form a soil retainer wall, each course being arranged substantially vertically relative to the others. As shown in FIG. 1 , the soil stabilization system 100 may also be substantially sloped if desired. In one exemplary embodiment, the soil stabilization system 100 may be stepped back at a 2 to 1 slope, wherein each succeeding course of bags is set back from the front of the underlying course of bags a horizontal distance of approximately one half the vertical thickness of the filled soil bags.
[0021] In the specification, “soil bag” 120 means a cover filled with any suitable fill material, including sand, soil, and mixtures thereof, and may also include fill mixed with seeds for grass or other plants. It is contemplated that the covers of the soil bags 120 may be formed from a variety of materials or combinations of such materials. In accordance with one embodiment, the covers of the soil bags 120 are comprised of needle-punch non-woven fabric such that, as will be described, plants may grow through the soil bags 120 and/or holes formed in at least the covers of the soil bags 120 . For example, the covers of the soil bags 120 may be a polypropylene, staple fiber, needle-punched, or non-woven geotextile. In one embodiment, the covers of the soil bags 120 may be comprised of woven fabric that allows plant growth to grow through the soil bags 120 and/or holes formed in the covers of the soil bags 120 , and may also ultimately decompose over time. The covers of the soil bags 120 may also comprise any other materials or combination of materials that will decompose or otherwise degrade over time.
[0022] The soil bags 120 and/or the fill material may include seeds that, after formation of the soil stabilization system 100 will produce plant growth 160 . In the specification, “plant growth” means any portion of any type of plant or plants, including portions such as roots and crowns of a plant or plants. A wide variety of seeds may be used to create various plant growth 160 from any number of types of plants including wild flowers, legumes, grasses, sedges and woody plants with extensive root structures. In one exemplary embodiment, indigenous plants and plant growth may be used. In one embodiment, as the plant growth matures, the plant growth extends through the soil bags 120 , and even into the ground or other surface below the soil stabilization system 100 , to reinforce the soil.
[0023] The soil stabilization system 100 further comprises at least one geogrid weaving strip 130 and/or geogrid twining strip 140 . In one embodiment, at least one geogrid weaving strip 130 is woven longitudinally between courses of soil bags of the soil stabilization system 100 . In one embodiment, at least one geogrid twining strip 140 is twined between courses of soil bags 120 in at least one of a substantially vertical and a substantially lateral direction relative to the soil stabilization system 100 . As will be shown below, the soil stabilization may advantageously comprise various combinations of soil bags and geogrid weaving and twining strips to hold the bags in a desired way. Because the soil stabilization system 100 utilizes plant growth and/or at least one geogrid strip 130 / 140 , one or more of the soil bags 120 used in forming the soil stabilization system 100 may comprise biodegradable, photo degradable, or otherwise decomposable material without substantially compromising the durability of the soil stabilization system 100 . As will be discussed in greater detail below, the soil stabilization system 100 may also comprise soil stabilizer bodies (not shown in FIGS. 1-2 ) to help hold the soil bags 120 and/or and geogrid strips 130 / 140 in a desired position.
[0024] Geogrid material is known and commercially available as plastic mesh sheet products commonly used for soil reinforcement. Conventional geogrid material is typically sold in roll of material having a sheet width of 12 to 14 feet, and such sheets are cut to desired lengths from a roll and embedded in soil and various applications to reinforce the soil and resist erosion thereof. FIG. 3 shows a modified geogrid material according to the present invention, wherein strips of material are specially fabricated in their desired widths for the purpose of weaving the strips around and between soil bags to anchor and retain the soil bags in position within a retaining wall or other soil retaining structure constructed of soil bags. While the overall length and width of each geogrid strip of the present invention may vary for various soil bag stabilization systems according to the present invention, the geogrid strips 130 / 140 are generally narrow in width to allow the strips to be wrapped under, over, around and between individual soil bags in a wall or other structure to lock or anchor the soil bags in position within an integrated wall structure wherein the individual soil bags and geogrid strips woven there through are held together by the combined action of the soil bags and woven geogrid material. Typically, the width of the weaving strips will be less than the width of the soil bags with which the strips will be used. In one embodiment, each geogrid strip 130 / 140 is between 2 inches and 6 inches in width and between 50 feet and 250 feet in length. In one embodiment, each geogrid strip 130 / 140 is approximately 4 inches in width and 100 feet in length. The only limits on the desired length of the strips are the size of the rolls produced, and the ease and economy of working with several rolls on a job to facilitate use by several workers on the same job.
[0025] Referring to FIGS. 4-5 , a perspective view and a side view of an exemplary embodiment of a soil stabilizer body 150 of the present invention are shown. As shown in FIG. 4 , in one exemplary embodiment, the soil stabilizer body 150 includes a circular-shaped outer frame 160 ; however, it is contemplated that the outer frame 160 may be formed in any of a variety of geometric shapes, including, without limitation, a trapezoid, rectangle, polygon, circle and/or oval.
[0026] In one embodiment, a plurality of truss members 170 extend within the margin of the outer frame 160 to provide additional structural support to the soil stabilizer body 150 . In one embodiment, a plurality of truss members 170 extend from the margin of the outer frame 160 to form a transverse web.
[0027] In one embodiment, the soil stabilization body 150 comprises at least one inner frame 190 interconnected to the truss members 170 . Each truss member 170 and the inner frame 190 and outer frame 160 define, at least in part, a plurality of passages within the margins of the outer frame 160 . While the truss members 170 , inner frame 190 and outer frame 160 are shown in FIG. 4 as having a rectangular cross section, the truss members may be tubular, rectangular, or take other cross-sectional forms.
[0028] As shown in FIG. 4 , in one embodiment, the collective passages are relatively large with respect to the overall structure of the soil stabilizer body 150 . For example, in various embodiments, it is contemplated that the collective passages may cover or otherwise comprise from 30% of the soil stabilizer body 150 up to and including 80% or more of the soil stabilizer body 150 . Thus, the frame and truss members of the body 150 are adapted to bear against the outer surface of a soil bag, while permitting moisture and the roots of vegetation to freely pass through the body members and into the soil bags.
[0029] In one embodiment, the soil stabilization body 150 includes a protruding member 180 extending from each side of the body. Each protruding member 180 may be of any shape or rigidity suitable for protruding spike-like into a soil bag. At least one of the distal ends of at least one protruding member 180 is generally tapered. In one embodiment, at least one of the distal ends of at least one protruding member 180 is substantially pointed, such as a spike or cleat. In the embodiment shown in FIGS. 4 and 5 the protruding members each comprise a plurality of radiating longitudinal ribs which resist twisting of the soil stabilization body 150 when the protruding members 180 are embedded in a soil bag.
[0030] It is contemplated that the soil stabilizer body 150 may be formed from a variety of materials or combinations of materials. For example, a soil stabilizer body 150 may be formed from plastic material. Additionally, the soil stabilizer body 150 may be formed from a biodegradable and/or photo-degradable material. For example, the soil stabilizer body 150 may be formed from a “green plastic,” such as corn starch polymer, wheat germ polymer, or other similar materials that eventually decompose to an organic material.
[0031] FIGS. 6( a )- 6 ( p ) illustrate steps in an exemplary method for constructing a soil stabilization system 100 according to the present invention. In one embodiment, ground 300 or other surface is suitably prepared as needed or desired for construction of a soil stabilization system 100 . For example, the ground 300 may be suitably prepared with a leveling pad or a concrete footing in order to support the retaining wall. Such ground 300 and/or surface preparation is conventional in the building of retaining walls.
[0032] Referring to FIG. 6( a ), in one embodiment, at least one geogrid weaving strip 130 is placed on the ground 300 or other surface along the length of the soil stabilization system 100 . In one exemplary embodiment, soil bags 120 are placed substantially above the geogrid weaving strip 130 at a first end of the soil stabilization system 100 , and at a second end of the soil stabilization system 100 , leaving a strip weaving end 210 at the first end of the soil stabilization system 100 and a strip remainder 220 at the second end of the soil stabilization system 100 . Referring to FIG. 6( b ), in one embodiment, a first plurality of soil bags 120 are then placed adjacent to each other on the geogrid weaving strip 130 between the soil bags 120 placed at the first and second ends of the soil stabilization system 100 to form a first course 230 of soil bags 120 . While the individual bags appear to be slightly separated in FIGS. 6( a )- 6 ( p ), for ease of illustration and understanding, it should be understood that the bags in the soil stabilization system of the present invention will normally be in tight abutment with each other and tamped in a known manner to provide a substantially continuous barrier wall to contain and stabilize soil fill 400 or other structure existing or to be placed behind the wall. Each soil bag 120 may have a seam running the length of one side of the soil bag 120 . In one or more exemplary embodiments, one or more soil bags 120 will be oriented in the soil stabilization system 100 seam side out to facilitate location of seeds for promoting plant growth, which seeds may be placed by hydroseeding of the finished wall. In one embodiment, the remainder 220 is wrapped around at least a portion of the soil bag 120 placed at the second end and over a portion of the first course 230 of soil bags 120 as shown in FIGS. 6( b )- 6 ( d ). In FIGS. 6( c )- 6 ( d ), the weaving end 210 is wrapped at least partially around the soil bag 120 placed at the first end of the soil stabilization system 100 and over at least a portion of the first course 230 . It should be noted that the weaving end 210 may be wrapped at least partially around at least one soil bag 120 located between the first and second ends, if so desired.
[0033] Referring to FIGS. 6( e )- 6 ( f ), in one embodiment, at least one geogrid twining strip 140 will be placed substantially cross-wise to the weaving strip 130 and under at least one of the plurality of soil bags 120 forming the first course 230 . The geogrid twining strips 140 may be oriented generally perpendicular to at least one of the longitudinal axes of the soil stabilization system 100 and the longitudinal axis of an overlying soil bag 120 . The geogrid twining strips 140 may be positioned such that there is at least one twining end 250 left uncovered by the overlying soil bag 120 . A twining remainder 260 may also remain uncovered by the soil bag, and may extend under the back fill (not shown) to be brought in and retained behind the soil bag wall being formed, or may be used for vertical double twining of the upwardly placed bags in the wall as shown in FIG. 6( o ).
[0034] In one embodiment, the twining end 250 is wrapped around a side of a soil bag 120 and over the top of the soil bag 120 . In one embodiment, the twining end 250 will be wrapped directly over a soil bag 120 and under a geogrid weaving strip 130 . In one embodiment, the twining end 250 is wrapped around and over the soil bag 120 and the geogrid weaving strip 130 atop that soil bag.
[0035] While gaps are shown between soil bags 120 in FIGS. 6( a )- 6 ( p ), the gaps are shown for ease of illustration. In various embodiments, the soil bags 120 will commonly be placed together tightly. Further, the geogrid weaving strips 230 and geogrid twining strips 240 should be woven and twined, respectively, quite tightly to the soil bags 120 and/or soil stabilization system 100 .
[0036] For example, as shown in FIGS. 6( c ), 6 ( h ), 6 ( k ), 6 ( l ) and 6 ( n ), as various courses are added, at least one soil bag 120 in each course may be pulled out from underneath the geogrid weaving strip 130 and re-placed in substantially the same location above the geogrid weaving strip 130 to help cinch and tighten the geogrid weaving strip 130 within and over that course and otherwise anchor it within the soil stabilization system 100 . Depending upon the length of each course of bags and the number of bags in each course, every third or fourth bag 120 in a course may be pulled from beneath the weaving strip 130 and replaced over the weaving strip back between the adjacent bags in its original position.
[0037] Referring to FIGS. 6( g )- 6 ( h ), in one embodiment, a second plurality of soil bags 120 are placed substantially above the first course 230 and at least one of the geogrid weaving strip 130 and geogrid twining strip 140 to form a second course 240 having a first end and a second end. In one embodiment, the weaving end 210 is wrapped around and over the soil bag 120 placed substantially at the second end of the second course 240 of the soil stabilization system 100 and over at least a portion of the second course 240 . FIGS. 6( g )- 6 ( a ) also show that it is advantageous to employ soil bags tied at the one-half full level at one end of a course of bags so that as the wall goes up, the bags will be staggered in brick-like fashion so that the full bags of each course rest upon each of two bags of the previous course. Alternatively, a full bag can be turned 90° at the end of a course to simulate a half full bag and maintain the overlapping positioning of the full bags.
[0038] As shown in FIG. 6( i ), in one embodiment, the twining end 250 of at least one geogrid twining strip 140 is wrapped at least partially around and over a soil bag 120 . In one embodiment, the twining end 250 may be wrapped directly over a soil bag 120 and under the geogrid weaving strip 130 substantially atop the second course of soil bags 120 . In one embodiment, the twining end 250 is wrapped around and over the soil bag 120 and the geogrid weaving strip 130 above that soil bag 120 . As further shown in FIGS. 6( i ), 6 ( j ), 6 ( m ) and 6 ( p ), the twining strip 140 may alternately pass around a single bag, then the end portion of the two bags lying on the single bag, and then a single bag lying on the two bags, and so on to bind the courses of bags together as a single unit. The twining strip 140 may be located at any point or points along the soil bag wall and bind any portions of the bags lying in a vertical path upwardly from such point in a single twined or double twined manner.
[0039] In an exemplary embodiment, the soil bags 120 of the second course 240 should be positioned such that each soil bag 120 comprising the second course 240 of soil bags 120 is placed on top of two soil bags 120 in the first course 230 in any staggered manner. In such an embodiment, completion of the second course 240 may require utilization of a less than a full soil bag 120 or lateral orientation of at least one soil bag 120 .
[0040] As shown in FIG. 6( i ), in one embodiment, one or more soil stabilizer bodies 150 may also be used in connection with the soil stabilization system 100 . In one exemplary embodiment, a plurality of soil stabilizer bodies 150 are placed over the geogrid strips 130 / 140 positioned above the soil bags 120 with the protrusions protruding down through holes in the geogrid strips 130 / 140 into the soil bags 120 . In one embodiment, the soil stabilizer bodies 150 may also be placed directly on top of soil bags 120 and the geogrid strips 130 / 140 may then be placed on top of the soil stabilizer bodies 150 and soil bags 120 so that the protruding member of the soil stabilizer body 150 protrudes through holes in the geogrid strips 130 / 140 . In one embodiment, when a second course 240 of soil bags 120 is put atop a first course of soil bags 120 , protruding members of the soil stabilizer body 150 will extend both into the underside of the second course 240 and through the geogrid strips 130 / 140 and into the top of the soil bags 120 in that first course 230 . The soil stabilizer bodies 150 may advantageously be placed, two on a bag, so that the bags of the next course, placed across the abutting ends of two bags in overlapping position, will each be engaged by two stabilizer bodies 150 , one projecting upward from each underlying overlapped bag.
[0041] Throughout the construction of the soil stabilization system 100 , one or more soil bags 120 may advantageously be tamped down in a conventional manner to help compact the soil bags 120 and/or help one or more soil stabilizer bodies 150 in contact with the soil bags 120 to be pierced by a protruding member of the soil stabilizer body 150 .
[0042] As shown in FIGS. 6( k )- 6 ( p ), construction of the wall may be continued in the same or similar manner until a soil stabilization system 100 of the required dimensions is completed. For example, additional courses may be added. During the construction of the soil stabilization system 100 , it may be necessary or desirable to utilize multiple geogrid weaving strips 130 and/or geogrid twining strips 140 during construction of the soil stabilization system 100 . Geogrid strips 130 / 140 may be tied together to lengthen the strips to allow completion of the soil stabilization system 100 . In another embodiment, the ends of the geogrid strips 130 / 140 may be wrapped around one or more soil bags 120 to help lock the geogrid strips 130 / 140 into place. In one embodiment, soil stabilization bodies 150 may be used to help anchor one or more geogrid strips 130 / 140 to the soil stabilization system 100 and to each other as desired.
[0043] In one embodiment, as discussed above, the soil bags 120 may contain a variety of seeds for vegetating at least a portion of the soil stabilization system 100 . To expedite the vegetation process, more mature vegetation 160 may be planted in the soil bags comprising the soil stabilization system 100 . Any combination of native plants, plugs, sod and seed may be so implanted. To implant the plants, plugs, sod and/or seed, one or more of the soil bags comprising the soil stabilization system 100 should be hydrated. In one exemplary embodiment, each soil bag is thoroughly soaked with water. By hydrating soil bags of the soil stabilization system 100 , the material comprising the soil bags may be punctured with minimal loss of soil and other soil bag content.
[0044] In one embodiment, any number of soil bags may be punctured where native plugs are to be inserted. One or more plugs may be inserted into each soil bag. In one exemplary embodiment, three native plugs are inserted into the top front face of a plurality of soil bags. The plugs may be pushed deeply into the soil bag until the soil bag fabric closes over the top of the soil core of the plug, leaving only the crown of the plug exposed. In one embodiment, the soil bag is tamped closely around the throat of the plug after insertion of the plug into the soil bag.
[0045] Plants, sod and/or seed may also be inserted between soil bags. In one exemplary embodiment, plants, sod and/or seed may be planted substantially where three soil bags meet and more specifically where two soil bags meet atop a soil bag of an underlying course. Flats made of sod may also be graded into the soil stabilization system 100 . In one embodiment, sod may be cut into strips and added between the soil bags and the outside of the soil bags as desired.
[0046] Vegetation of the soil stabilization system may be continued in the same manner, as desired. After the soil stabilization system is vegetated, the soil stabilization system may be watered immediately to help insure that vegetation 160 is hydrated.
[0047] The soil stabilization system 100 of the invention, consisting in combination of soil bags 120 , interwoven geogrid weaving and twining strips 130 / 140 , soil stabilizer bodies 150 and fibrous vegetation 160 , or selected ones thereof, effectively provides a uniform wall or other soil stabilization structure which will stabilize soil or fill material 400 retained behind the structure to minimize soil erosion in a substantially permanent manner, with the capability of becoming stronger and more securely bound together as the fibrous vegetation grows and matures.
[0048] While various embodiments of the present invention have been described in detail, it is apparent that modifications and alterations of those embodiments will occur to those skilled in the art. However, it is to be expressly understood that such modifications within the scope and spirit of the present invention, as set forth in the following claims. | A soil stabilization system comprised of recent courses of soil bags woven and/or intertwined with geogrid and soil stabilization bodies pierce the soil stabilization bodies and protrusions on sides which protrude into the soil bags of the adjacent courses. Protrusions on the soil stabilization bodies shall protrude through holes in the geogrid to help anchor the soil bags relative to each other. | 4 |
FIELD OF THE INVENTION
The invention relates to a hard seal plug valve.
DESCRIPTION OF THE RELATED ART
Owning to simple structure, quick opening and closing and relatively small pressure drop, plug valves are widely applied to a certain extent. The plug valves are divided into hard seal plug valves and soft seal plug valves.
Sealing and lubricating films must be established between the tapered outer surface of an existing soft seal plug valve and the tapered inner surface of a valve cavity. Axial seal pressure is arranged at the large end of a tapered plug, and the tapered plug still keeps the same seal pressure during rotation, thus the rotating torque is large, and the sealing surface also suffers from serious wear. High-temperature impact and vibration will damage the lubricating film, so that the plug is attached to the valve cavity, and cannot be rotated, opened and closed. When in use, the tapered plug is off the valve cavity once because of high temperature and sudden pressure rise in the line, causing the medium in the line to flow into the seal cavity, possibly washing the seal film away.
Although the hard seal plug valve is not provided with a seal film, the rotating torque is very large, and the sealing surface suffers from more serious wear.
Plug valves with plug being lifted firstly and then pressed after rotation once occurred, such as lift plug valves and double-acting plug valves. However, both need more than two operating mechanisms or more than two actions, so that the valves are complex in structure and inconvenient to operate. Therefore, the improved plug valves are not widely applied.
Invention patent ZL200710046094 discloses a floating tapered plug valve with simple structure, and “lifting the plug firstly, and then pressing it after rotation” can be completed by only one action. Although the patent solves the sealing and switching problems well, but it also has the following problems:
Firstly, a compression spring is used as the device for floating the tapered plug before the valve switching. When the tapered plug is jammed (locked) by the sealing surface of the seal cavity, the compression spring has static elasticity only instead of impact force, and the jammed (locked) tapered plug can be removed from the valve cavity by a rising impact force, thus the use of compression spring cannot reliably float the tapered plug. Meanwhile, the spring is required to have certain elasticity to float the tapered plug, but the elasticity needs to be overcome while the tapered plug is pressed. If there is no spring causing the tapered plug to float, an axial force of 10000N is applied to press the tapered plug to the seal pressure. After the floating spring is arranged, if the elasticity of the compression spring is 20000N after compression, additional 20000N axial force plus 10000N axial force is required to overcome the elasticity of the spring. Total axial force of 30000N is thus required to press the tapered plug, and the force applied is 3 times of the original force, that is, the driving force required to drive the valve rod is increased by 2 times additionally.
Secondly, a torque limiter is used to rotate the tapered plug. That is, when the tapered plug floats, the torque for rotating the tapered plug is fixed. A higher torque will cause the drive valve rod to remove from the tapered plug and skid, and the drive valve rod continues rotation and presses the tapered plug. When the valve is switched to the closed condition from the open condition, a swirling moment occurs as dynamic pressure caused by the flow rate of the fluid will prevent change in direction of the channel of the tapered plug. The swirling moment is the resistance stopping rotation of the tapered plug, and is associated with the pressure and flow rate of the fluid. Therefore, the torque limiter with fixed torque cannot ensure reliable rotation of the tapered plug in general.
SUMMARY OF THE INVENTION
The purpose of the invention is to provide a plug valve capable of closing and opening the valve quickly and reliably.
In order to achieve the purpose above, the technical solution of the invention provides a hard seal plug valve. The hard seal plug valve comprises a valve body which comprises a first through channel and a second through channel for flowing of a medium, a tapered valve cavity communicated with the first through channel and the second through channel, and a plug through port communicated with the first through channel and the second through channel in an open condition. A rotatable tapered plug for blocking the first through channel and the second through channel in a closed condition is arranged in the tapered valve cavity. A bonnet assembly is arranged at the upper part of the valve body, and a drive valve rod penetrates the bonnet assembly. A valve rod bearing seat is arranged at the bottom of the drive valve rod. The hard seal plug valve is characterized in that a telescopic mechanism allowing the tapered plug to move upward and an elastic hold-down mechanism allowing the tapered plug to move toward the tapered valve cavity are sheathed on the drive valve rod. A plug bearing seat is connected with the tapered plug, and the telescopic mechanism extends when the elastic hold-down mechanism retracts due to rotation of the drive valve rod. The tapered plug is pushed upward by the plug bearing seat, and the telescopic mechanism retracts and the elastic hold-down mechanism extends due to continual rotation of the drive valve rod. The tapered plug is pressed toward the tapered valve cavity by the plug bearing seat to be under the seal pressure. The valve rod bearing seat is provided with an upper limiting shaft shoulder and a lower limiting shaft shoulder, and a part between the upper limiting shaft shoulder and the lower limiting shaft shoulder is tapped on the valve rod bearing seat. A sun gear is sheathed on the threads of the valve rod bearing seat, and an inner gear coplanar with the sun gear is connected to the upper part of the valve body. Two or three planet gears are arranged between the inner gear and the sun gear, and a planet gear rotating shaft at the middle of the planet gears is connected with the tapered plug. When the drive valve rod begins to rotate, the sun gear only rotates upward and downward, but does not transfer torque. Only after the tapered plug moves upward and the sun gear is limited by the upper limiting shaft shoulder or the lower limiting shaft shoulder, the drive valve rod drives the sun gear to rotate, and drives the tapered plug to rotate to a certain angle and limit the tapered plug. At this moment, the planet gears slip while the drive valve rod can continue to rotate till completion of opening and closing operation.
In the invention, the telescopic mechanism driven by threads is used to float the tapered plug. When the tapered plug is floating, a planetary reduction mechanism is used to rotate the tapered plug. After rotation, the tapered plug is pressed toward the valve cavity by the elastic hold-down mechanism and is under seal pressure, thus achieving reliable floating, rotation and sealing of the tapered plug in any case. The driving moment of the plug valve is at least 7 times less than that of a general plug valve. For example, a DN100 and 4.0 MPa common hard seal plug valve needs the driving moment of 150N·m generally, but the driving force of 20N·m is enough for the valve of the invention.
BRIEF DESCRIPTION OF THE DRAWINGS
FIG. 1 is a schematic diagram of a hard seal plug valve in a closed condition;
FIG. 2 is a schematic diagram of fit between a drive valve rod and an inner screw rod of a telescopic mechanism;
FIG. 3 is a schematic diagram of the hard seal plug valve in an intermediate condition when the plug has been turned;
FIG. 4 is a schematic diagram of fit of an elastic hold-down mechanism;
FIG. 5A is a sectional view of the telescopic mechanism;
FIG. 5B is a schematic diagram of several assemblies of the telescopic mechanism;
FIG. 6A is a front view of an orthohexagonal upper switching pin;
FIG. 6B is a top view of the orthohexagonal upper switching pin;
FIG. 7A is a front view of an orthohexagonal lower switching pin;
FIG. 7B is a top view of the orthohexagonal lower switching pin;
FIG. 8A is a front view of a circular upper switching pin;
FIG. 8B is a top view of the circular upper switching pin;
FIG. 9A is a front view of a circular lower switching pin;
FIG. 9B is a top view of the circular lower switching pin;
FIG. 10 is a structural diagram of a planetary reduction mechanism when the valve is closed after the drive valve rod rotates clockwise;
FIG. 11 is a schematic diagram of a four-way plug valve with the telescopic mechanism arranged below the tapered plug; and
FIG. 12 is a schematic diagram of the four-way plug valve with the telescopic mechanism driven by magnetic induction arranged below the tapered plug.
DESCRIPTION OF THE PREFERRED EMBODIMENTS
The invention is further described in combination with examples as follows.
Example 1
The invention provides a hard seal plug valve, and the work process is generally as follows: a plug valve shown in FIG. 1 is in off state, and a plug through port 30 at the middle of a tapered plug 2 is communicated with a first through channel 33 and a second through channel 24 of a valve body 1 at the moment. When the plug valve is opened, a drive valve rod 5 is rotated anticlockwise and an elastic hold-down mechanism retracts intermediately. FIG. 2 shows that the drive valve rod 5 is in clearance fit with an inner screw rod 52 of a telescopic mechanism 15 . When elastic stroke of a disk spring 9 of the elastic hold-down mechanism extends to fully relaxed condition, the inner screw rod 52 of the telescopic mechanism 15 starts to rotate anticlockwise with the drive valve rod 5 , and the telescopic mechanism 15 starts to extend to push upward the plug bearing seat 14 , thus driving the tapered plug 2 upward. The drive valve rod 5 is continuously rotated anticlockwise when the tapered plug rises to a certain position, the tapered plug 2 is driven by a planetary reduction mechanism, both ends of the plug through port 30 are aligned with the first through channel 33 and the second through channel 24 respectively, the telescopic mechanism 15 retracts at the same time, while the elastic hold-down mechanism extends to press the plug bearing seat 14 so as to drive the tapered plug 2 down until the tapered plug 2 drops in place, then the valve is opened. The structure of the invention is further described below in combination with the drawings.
FIG. 1 and FIG. 3 show that the hard seal plug valve of the invention comprises the valve body 1 . The first through channel 33 and the second through channel 24 for flow of the medium are arranged on the left and right sides of the valve body 1 , and a tapered valve cavity 32 communicated with the first through channel 33 and the second through channel 24 is arranged in the valve body 1 . A valve body bearing seat 3 is arranged on the top of the valve body 1 by bonnet locking screws 25 on both sides. A flange locking gasket 26 is arranged between the valve body 1 and the valve body bearing seat 3 . A valve body flange 28 is fixed at the bottom of the valve body 1 by a valve body flange locking screw 27 . A bonnet 6 is arranged on the valve body bearing seat 3 , a lock nut 4 is inserted into the top end of the bonnet 6 , and a seal assembly 7 is arranged between the lock nut 4 and the bonnet 6 . The tapered plug 2 is arranged in the tapered valve cavity 32 of the valve body 1 , and the plug through port 30 is arranged at the middle of the tapered plug 2 . The plug through port 30 is communicated with the first through channel 33 and the second through channel 24 when the valve is in open condition. Balance holes 29 are arranged on both sides of the plug through port 30 . The tapered plug 2 can float up and down and rotate in the tapered valve cavity 32 . The first through channel 33 and the second through channel 24 are blocked by the tapered plug 2 when the valve is in closed condition. The drive valve rod 5 is arranged in the valve body bearing seat 3 after passing through the lock nut 4 , the bonnet 6 and the seal assembly 7 .
FIG. 4 shows that the elastic hold-down mechanism is sheathed on the drive valve rod 5 . The elastic hold-down mechanism comprises an inner hold-down housing 11 . The inner hold-down housing 11 is sheathed on the drive valve rod 5 , and an outer hold-down housing 12 is sheathed on the inner hold-down housing 11 . The inner hold-down housing 11 is coordinated with the outer hold-down housing 12 by a thread pair. Needle bearings 10 are arranged on the inner hold-down housing 11 and the outer hold-down housing 12 . The needle bearings 10 are sheathed on the drive valve rod 5 . The disk spring 9 is arranged between the needle bearings 10 and the valve body bearing seat 3 . The inner hold-down housing 11 and the outer hold-down housing 12 are arranged on the plug bearing seat 14 , and the plug bearing seat 14 is connected with the tapered plug 2 .
FIG. 5A and FIG. 5B show that the telescopic mechanism 15 is arranged outside the drive valve rod 5 . The telescopic mechanism 15 comprises a liner 51 with inner thread and outer thread on both sides, the inside and the outside of the liner 51 are provided with inner screw rods 52 and housings 48 respectively, and the liner 51 is arranged between the inner screw rod 52 and the housing 48 by a key. The inner screw rod 52 is sheathed on the drive valve rod 5 . The middle part of the inner screw rod 52 is an inner hole with a key slot in clearance fit with the drive valve rod 5 with a key pin. The inner screw rod 52 is driven to rotate with the drive valve rod 5 , but its axial movement is not limited. The first thread with an upper shaft shoulder 57 and a lower shaft shoulder 58 is arranged on the outside of the inner screw rod 52 . The first thread is a clockwise thread. The second thread with the upper and lower shaft shoulders are arranged on the inside of the housing 48 . The inside and the outside of the housing 51 are provided with inner thread and outer thread respectively. The outer housing 48 is sheathed on the liner 51 and coordinated with the outer thread of the liner 51 . The upper and lower shaft shoulders of the outer housing 48 can limit the movement range of the liner 51 . The length and pitch of the thread between the upper and lower shaft shoulders are equal to the length and pitch of the outer thread of the inner screw rod 52 . The inner thread of the liner 51 is coordinated with the first thread of the inner screw rod 52 and is short screw only moving between the upper shaft shoulder 57 and the lower shaft shoulder 58 of the inner screw rod 52 . The outer thread and the inner thread of the liner 51 have equal pitch but opposite rotation directions. Therefore, the first thread and the inner thread form a first thread pair, the second thread and the outer thread form a second thread pair, and the rotation directions of the first thread pair and the second thread pair are opposite. A rotating downward caging device 53 and a rotating upward caging device 54 are arranged between the outer housing 48 and the inner screw rod 52 . The rotating downward caging device 53 and the rotating upward caging device 54 are arranged above and blow the liner 51 respectively. The upper and lower ends of the inner part of the outer housing 48 are provided with key slots which are similar to the rotating downward caging device 53 and the rotating upward caging device 54 in shape, and cause the rotating downward caging device 53 and the rotating upward caging device 54 sheathed in the outer housing 48 to fail to relatively rotate. The shape of the outer part of the outer housing 48 can limit its rotation and prevent rotation of the outer housing 48 in coordination with the plug bearing seat 14 . The rotating downward caging device 53 and the rotating upward caging device 54 are two heads sheathed on the inner screw rod 52 and in the liner 51 .
The rotating downward caging device 53 comprises an upper switching pin 60 . The bottom of the upper switching pin 60 is provided with an upper fixture block 61 . An upper insertion slot 62 is arranged on the upper edge of the liner 51 . The upper insertion slot 62 is coordinated with the upper fixture block 61 so that the liner 51 can not rotate anticlockwise but can rotate clockwise. A first spring 50 is connected between the upper switching pin 60 and the inner screw rod 52 . The rotating upward caging device 54 comprises a lower switching pin 63 . The bottom of the lower switching pin 63 is provided with a lower fixture block 64 . A lower insertion slot 65 is arranged on the lower edge of the liner 51 . The lower insertion slot 65 is coordinated with the lower fixture block 64 so that the liner 51 can not rotate clockwise but can rotate anticlockwise. A second spring 55 is connected between the lower switching pin 63 and the inner screw rod 52 . Either of the upper switching pin 60 and the lower switching pin 63 of the rotating downward caging device 53 and the rotating upward caging device 54 is blocked in the slot of the liner 51 under the action of the first spring 50 and the second spring 55 .
The inner walls of the upper switching pin 60 and the lower switching pin 63 are a-step shape. The upper part of the inner screw rod 52 is provided with the upper shaft shoulder 57 which is coordinated with the step-shaped inner wall of the upper switching pin 60 . The lower shaft shoulder 58 is arranged on the lower part of the inner screw rod 52 , and the lower shaft shoulder 58 is coordinated with the step-shaped inner wall of the lower switching pin 63 .
If the first thread between the upper shaft shoulder 57 and the lower shaft shoulder 58 of the inner screw rod 52 is a clockwise thread with length L and the length of the liner 51 is T, the inner thread of the liner 51 is also a clockwise thread and the outer thread must be the anticlockwise thread, T must be less than L, and the pushed upward stroke S of the whole telescopic mechanism 13 is L−T.
When the telescopic mechanism 15 is in the condition as shown in FIG. 5B , the upper fixture block 61 of the upper switching pin 60 is blocked in the upper insertion slot 62 of the liner 51 , and the step-shaped inner wall in the lower switching pin 63 is blocked by the inner screw rod 52 , so the lower fixture block 64 is separated from the lower insertion slot 65 of the liner 51 . And the drive valve rod 5 is rotated anticlockwise. When the drive valve rod 5 is in clearance fit with the inner screw rod 52 through rotation, the inner screw rod 52 is driven to rotate with the drive valve rod 5 anticlockwise. As the upper fixture block 61 is blocked in the upper insertion slot 62 of the liner 51 and the liner 51 rotates anticlockwise, the second thread pair does not work. At the same time, the inner screw rod 52 rises under the action of the first thread pair. The upper switching pin 60 is driven upward after the upper shaft shoulder 57 of the inner screw rod 52 contacts the step-shaped inner wall of the upper switching pin 60 . When the inner screw rod 52 rises until the lower end surface D of the liner 51 is in contact with the end surface of the lower shaft shoulder 58 of the inner screw rod 52 , the upper fixture block 61 is completely separated from the upper insertion slot 62 , the liner 51 can rotate anticlockwise, and the lower fixture block 64 can be blocked in the lower insertion slot 65 (ready for clockwise rotation of the drive valve rod 5 ). The drive valve rod 5 is continuously rotated. As movement of the first thread pair is limited by the end surface of a lower lug 58 of the inner screw rod 52 , the inner screw rod 52 drives the liner 51 to drop with the liner 51 under the action of the second thread pair until the lower end surface D of the liner 52 is in contact with the surface E of the lower shaft shoulder of the outer housing 48 . Then the inner screw rod 52 is flush with the outer housing 48 to complete an extension and retraction process.
In order to ensure that the upper switching pin 60 and the lower switching pin 63 will not rotate relative to the outer housing 48 , the outer walls of the upper switching pin 60 and the lower switching pin 63 can be designed to be regular polygon as shown in FIG. 6A to FIG. 7B . Then the inner wall of the outer housing 48 without the second thread on both ends is a regular polygon which is coordinated with the shape of the outer walls of the upper switching pin 60 and the lower switching pin 63 .
If the outer walls of the upper switching pin 60 and the lower switching pin 63 are circular, as shown in FIG. 8A to FIG. 9B , straight stroke groove is arranged on the outer walls of the upper switching pin 60 and the lower switching pin 63 , and one side of an outer housing transmission flat key 49 is arranged in the straight stroke groove, while the other side is fixed onto the inner wall of the outer housing 48 .
FIG. 1 and FIG. 3 show that a valve rod bearing seat 16 is arranged at the bottom of the drive valve rod 5 , and a thread with an upper limiting shaft shoulder 17 and a lower limiting shaft shoulder 19 is set at the bottom of the valve rod bearing seat 16 . The thread passes through the planetary reduction mechanism. The tapered plug 2 is connected with the planetary reduction mechanism and rotates with the drive valve rod 5 along with the planetary reduction mechanism. When the drive valve rod 5 rotates until the elastic hold-down mechanism retracts entirely, the telescopic mechanism 15 totally extends and drives the tapered plug 2 upward to the highest position, and the upper limiting shaft shoulder 17 obstructs the sun gear 18 of the planetary reduction mechanism, thus driving the sun gear 18 to rotate. When the drive valve rod 5 rotates in an opposite direction until the elastic hold-down mechanism retracts entirely, the telescopic mechanism 15 totally extends and drives the tapered plug 2 upward to the highest position, and the lower limiting shaft shoulder 19 obstructs the sun gear 18 of the planetary reduction mechanism.
In combination with FIG. 10 , the planetary reduction mechanism comprises the sun gear 18 . The sun gear 18 is sheathed on the thread between the upper limiting shaft shoulder 17 and the lower limiting shaft shoulder 19 . When the drive valve rod 5 starts rotation, the sun gear 18 rotates upward and downward only without torque transmission. Only when the rotation between the sun gear 18 and the drive valve rod 5 is limited by the upper limiting shaft shoulder 17 , the drive valve rod 5 drives the sun gear 18 to rotate. An inner gear 23 is fixedly arranged at the upper part of the valve body 1 coplanar with the sun gear 18 . Three planet gears 22 engaged with the inner gear 23 and the sun gear 18 are arranged between inner gear 23 and the sun gear 18 , and a planet gear rotating shaft 21 connected with the tapered plug 2 is arranged among the planet gears 22 . Three continuous tooth sections with the same stroke are arranged on the inner gear 23 , and a planet gear 22 is engaged onto each continuous tooth section which is provided with 2 movable tooth assemblies.
For the purpose of limiting, an arc stroke groove is arranged on the inner gear 23 , and a valve core limiting pin 31 fixed on the tapered plug 2 is arranged in the arc stroke groove. Radian of the arc stroke groove is equivalent to the rotation angle required for the tapered plug 2 from the open condition to the closed condition or from the closed condition to the open condition (generally 90°).
The movable tooth assembly comprises a first movable tooth 40 and a second movable tooth 37 . The first movable tooth 40 is arranged symmetrical with the second movable tooth 37 . The first movable tooth 40 and the second movable tooth 37 rotate around a movable gear shaft 39 . A first movable tooth spring 42 and a second movable spring 38 are connected with the first movable tooth 40 and the second movable tooth 37 separately. A first limit stop 41 and a second limit stop 43 are arranged above and below the ends of the first movable tooth 40 and the second movable tooth 37 separately.
The drive valve rod 5 drives the sun gear 18 to rotate clockwise, and the sun gear 18 drives the planet gears 22 to rotate anticlockwise and the tapered plug 2 to rotate clockwise to point A. Then the teeth of planet gears 22 and the first movable tooth 40 slip, and planet gears 22 only rotate without driving the tapered plug 2 . Similarly, the second movable tooth 37 slips while the drive valve rod 5 drives the tapered plug 2 to point B when the sun gear 18 to rotates anticlockwise.
In combination with the drawings, the whole process from the open to closed condition of the hard seal plug valve provided by the invention is described below: as shown in FIG. 1 , after the drive valve rod 5 is rotated clockwise to the bottom, the plug valve is in off condition. The inner hold-down housing 11 and the outer hold-down housing 12 then stagger and extend, while the outer housing 48 is level with the inner screw rod 52 , and a certain stroke is reserved between the lower limiting shaft shoulder 19 and the sun gear 18 . After the drive valve rod 5 is rotated anticlockwise, driven by the drive valve rod 5 , the inner hold-down housing 11 rotates upward relative to the outer hold-down housing 12 , and the elastic hold-down mechanism retracts, while the inner screw rod 52 rotates upward by the drive valve rod 5 and push upward the plug bearing seat 14 , thus driving the tapered plug 2 to move upward. When the drive valve rod 5 is rotated until the elastic hold-down mechanism retracts entirely, the inner screw rod 52 rotates upward and drives the tapered plug 2 to the highest position. The lower limiting shaft shoulder 19 obstructs the sun gear 18 so as to drive the sun gear 18 to rotate anticlockwise and drive the planet gears 22 to rotate clockwise and revolves anticlockwise around the sun gear 18 , thus driving the tapered plug 2 to rotate. The tapered plug 2 is rotated from point A to point B. The valve core limiting pin 31 fixed onto the tapered plug 2 is moves to the position due to limitation by the arc stroke groove arranged on the inner gear 23 . Then the plug through port 30 on the tapered plug 2 is aligned with the first through channel 33 and the second through channel 24 on both ends. As shown in FIG. 3 , the plug valve is opened, the teeth of the planet gears 22 and the second movable tooth 37 slip, and the plant gears 22 rotate only without driving the tapered plug 2 . Meanwhile, the lower lug of the inner screw rod 52 is obstructed by the lower end surface D of the liner 51 . The inner screw rod 52 drives the liner 51 to rotate downward, and the telescopic mechanism 15 starts retraction and the elastic hold-down mechanism starts extension again until the inner screw rod 52 is level with the outer housing 48 and the inner hold-down housing 11 and the outer hold-down housing 12 stagger and extend to the maximum position. Then the tapered plug 2 is totally blocked in the tapered valve cavity 32 of the valve body 1 . If the plug valve needs to be closed, the drive valve rod 5 is rotated clockwise according to the same principle to open the valve.
Example 2
FIG. 11 is a schematic diagram of a four-way plug valve when a telescopic mechanism is arranged below the tapered plug. The difference between the plug valve in this example and the plug valve in example 1 is that the telescopic mechanism 15 is arranged below the tapered plug 2 while the tapered plug 2 has a four-way channel in coordination with the valve body 1 . Other mechanisms and their principles are the same as example 1.
Example 3
As shown in FIG. 12 , the difference between this example and example 2 is that the mechanism is driven by magnetic induction, that is, a ring of magnet 66 is arranged around the drive valve rod 5 at the top end of the drive valve rod 5 and is covered by a shielding cover 67 . The shielding cover 67 is made of a nonmagnetic material like stainless steel, copper or plastic so that the magnetic force of the magnet 66 will not be obstructed. In use, a ring of magnet is arranged outside the shielding cover 67 . The magnet inside the shielding cover 67 corresponds to the magnet outside the shielding cover but they have opposite polarity. When the magnet outside the shielding cover 67 rotates, it drives the magnet 66 in the shielding cover 67 to rotate, thus driving the drive valve rod 5 to rotate and achieve magnetic induction. Other mechanisms of this example and their principles are the same as example 1. | The invention provides a hard seal plug valve, comprising a valve body, wherein a tapered plug is arranged in the valve body, a bonnet is arranged at an upper part of the valve body, a drive valve rod penetrates the bonnet, an elastic hold-down mechanism is sheathed on the drive valve rod and arranged on a plug bearing seat, the plug bearing seat is connected with the tapered plug, and the plug bearing seat is held down when the elastic hold-down mechanism extends; and the hard seal plug valve characterized in that a telescopic mechanism is sheathed on the drive valve rod, the plug bearing seat is pushed upward when the telescopic mechanism extends, a valve rod bearing seat is arranged at the bottom of the drive valve rod, ends of the valve rod bearing seat pass through a planetary reduction mechanism, and the tapered plug is connected with the planetary reduction mechanism and rotates with the drive valve rod by the planetary reduction mechanism. In the invention, the tapered plug can reliably float and rotate under any circumstances. The drive torque of the plug valve is at least 7 times less than that of a general plug valve, therefore, when a motor is used, a general valve requires 2 minutes from opening to closing, and the valve of the invention only requires 3.8 seconds. | 5 |
BACKGROUND OF THE INVENTION
1. Field of the Invention
This invention pertains to the field of ultrasonic welding of plastics generally and specifically to a process for controlling compression of a seal or spring during the welding process.
2. Description of the Related Art
U.S. Pat. No. 4,631,685 to Peter, incorporated herein by reference, illustrates the prior art which applicants are aware of. Known processes for ultrasonic welding operate from dimensional stack up. Each component is dimensionally measured at the point of weld energy application and summed to other measurements to calculate a total stack up dimension of components at the intended weld site. Once the total stack up distance is calculated, a particular weld distance which has been determined through trial and error is summed with the stack up distance. This gives a calculated weld termination point.
In operation, the components are stacked together and positioned in line with the ultrasonic welding horn. The horn is caused to move towards the components with ultrasonic energy being supplied to the horn. The position of the horn is monitored by a linear position encoder. The position is compared to the earlier calculated weld termination point. Once the horn has reached the termination point, ultrasonic energy is ceased to be applied to the horn and the horn is briefly maintained in position. The weld junction is allowed to set and the horn then removed in preparation for the next weld cycle. Further details of the operation may be gleaned from the Peter disclosure.
While this welding process performs satisfactorily for certain types of operations, applicants have had the task of very reliably welding together two pieces of plastic which in turn apply a compressive force at a location remote from the weld to an elastomeric gasket. While stack up calculations provide some repeatability, unfortunately several variables are introduced which can not be determined based upon stack up measurements alone.
From lot to lot and even within lots, elastomeric gaskets vary in distance of compression required to produce a given compressive force. The reliability of a seal is dependent upon the compressive force applied to the seal, not the distance of compression. For example, if too great a compressive force is applied to the seal, relative motion between the parts being sealed results in greatly accelerated wear to the gasket. Where too light a force is applied, certain changes such as temperature variations which affect each of the components differently may result in a reduction of sealing force below that which would be required for liquid or vapor permeation of the seal.
Additionally, and similar to the elastomeric gaskets, from lot to lot and within lots the parts which are to be welded together have varying shapes and dimensions. The variations in shape are a direct consequence of the plastic molding operation used to form the parts. Some parts may exhibit much greater curvature from edge to center than others and there will likely be variances in thickness at particular points along the plastics depending upon shrinkage variations within the plastic during cooling after molding.
A measurement of stack up at the weld point does not identify dimensional variations which must be compensated for in order to provide a predictable sealing compression. Further, strictly dimensional measurements do not anticipate the variation of thickness between the weld location and the location of gasket compression which will result in different forces being transmitted to the gasket location from the weld site for a given identical horn displacement.
SUMMARY OF THE INVENTION
A method for ultrasonic bonding is disclosed which comprises the steps of supporting a component to be bonded in a nest, applying a force to said component along a first axis relative to said component, measuring a first displacement of a first portion of said component along said first axis at a first time, releasing said force, heating a second portion of said component by application of ultrasonic energy, measuring a second displacement of said first portion of said component along said first axis, and discontinuing said heating so as to produce a substantially permanent displacement of said first portion of said component substantially equal to said first displacement.
BRIEF DESCRIPTION OF THE DRAWINGS
FIG. 1 illustrates a station which may be used in conjunction with the first stage of the welding process.
FIG. 2 illustrates a station which may be used in conjunction with the second stage of the welding process.
FIG. 3 illustrates a component which may be welded using the welding process.
DESCRIPTION OF THE PREFERRED EMBODIMENT
Referring to FIG. 1, a target displacement measuring station 1 is generally illustrated. The station includes a adjustable force application device 2, a nest 3 for holding a part 6 to be measured, and a linear encoder 4 having an output 5. For the purposes of this disclosure the encoder is presumed to contain any necessary components required to produce a digital signal adequate for interpretation by computer 7. This may be accomplished either directly through the use of a gray scale encoder or other similar digital device or alternatively by an analog sensor combined with appropriate analog to digital conversion devices. The adjustable force application device 2 may be a combination of a load sensor made by Omega Engineering Incorporated of Stamford, Conn. and a force generator comprised of a servo-motor made by Aerotech Incorporated of Pittsburgh, Pa. and a precision lead screw made by Universal Thread Grinding Company of Fairfield, Conn., although other more basic designs such as a simple free weight balance could be used. The only requirement is that the adjustable force application device 2 be capable of applying a predetermined force to the part 6. In operation, the adjustable force application device 2 is caused to travel towards part 6 which is resting on nest 3. In the preferred embodiment the adjustable force application device 2 travels a sufficient distance to cause a force of predetermined magnitude to be applied to part 6. The force is measured by the adjustable force application device 2 internally. Once the predetermined force is achieved the position output 5 from the linear encoder 4 is sampled by a control computer 7 which could be an IBM AT type computer. The adjustable force application device 2 then releases in preparation for the next part to be tested. The part 6 is then transferred either mechanically or by hand to the second station illustrated in FIG. 2, although this could readily be accomplished in a single station by one skilled in the art.
Referring now to FIG. 2, the position output 5 is sampled by the computer 7. Once part 6 is loaded, the system is activated either manually or, in the event part 6 is mechanically loaded, by an activation signal from a sensor. The computer generates a signal which is translated by servo card 8, which could be DMC-400-10 available from Galil Motion Control Incorporated of Palo Alto, Calif., into a control signal 16 which is used to control DC servo motor 9. When DC servo motor 9 is activated, lead screw 12 is caused to rotate moving horn 13 towards nest 14 which holds part 6. Simultaneously, the computer forwards a control signal to the welder electronics 11 and through line 17 energizes horn 13 with ultrasonic energy. The horn 13 and welder electronics 11 are available for example from Branson Ultrasonics Corporation of Danbury, Conn. As horn 13 moves toward nest 14, eventually linear encoder 15 will be displaced. Computer 7 samples the output from linear encoder 15 through line 18 and when linear encoder indicates a position has been achieved which matches the position earlier determined from output line 5, the computer forwards a signal to the welder electronics which results in a de-energization of horn 13. The welder is briefly maintained in this position to allow the weld to harden and then the lead screw is rotated so as to remove horn 13 from contact with part 6. Part 6 may now be removed from nest 14 and forwarded on for any additional processing which may be required for the application. The ultrasonic welding process according to the preferred embodiment is now complete.
While the foregoing illustrates the use of a DC servomotor for generation of motion of the horn 13, other well known methods in the prior art such as pneumatic systems or hydraulic systems are contemplated and incorporated herein. One example of a suitable system is disclosed by Peter in U.S. Pat. No. 4,631,685 discussed hereinabove. The Peter system would replace components 9,10,11,12,13, and 17. There are advantages to be gained using a pneumatic system which will be known to those skilled in the art. Additionally, all components for a pneumatic system are available for example through Branson Ultrasonics Corporation earlier mentioned.
In an alternative embodiment, the target displacement measuring station 1 illustrated in FIG. 1 may be activated so as to only apply a force which causes all parts to come into contact without compressing the sealing gasket. For the part 6 which will be discussed in detail hereinbelow in reference to FIG. 3, the force required for flexure of the cover is significantly less than the force required for flexure of the cover and simultaneous compression of the sealing gasket. Therefore, the adjustable force application device may be programmed for a magnitude of force which is less than would be required for compression of the sealing gasket while still being of greater magnitude than that which would be required for flexure of the cover. In this embodiment computer 7 adds an incremental distance to the position indicated by output line 5 so as to produce a certain distance of compression of the sealing gasket during welding.
Referring now to FIG. 3 a cross sectional view of part 6 is illustrated. While the part may take any configuration which would be appropriate for operation of this invention, this figure is provided for an illustration of one industrial application of the invention and also serves to illustrate the test part configuration used to arrive at the comparison values detailed in table 1. The part 6 has a cover 19, a base 20, rotor 21 and sealing gasket 22. In operation, part 6 is sealed by an ultrasonic weld 24 between cover 19 and base 20. Additionally, cover 19 and base 20 are deformed under stress sufficiently to apply a compressive force to sealing gasket 22 through rotor 21 so as to enact a water tight seal therebetween. In operation, the part 6 is attached through rotor 21 to a rotating shaft (not illustrated) which spins rotor 21 relative to cover 19 and base 20. The shaft is on an axis which is parallel to arrow 23. Conveniently, this provides an access to rotor 21 during manufacture wherein the linear encoders 4 and 15 may contact rotor 21 to measure linear displacement. During welding, cover 19 is forced closer to arrow 23 by a displacement of material at weld 24. This results in compression of gasket 22, creating the necessary hermetic seal for the entire package while still enabling rotation of rotor 21.
EXAMPLE
Using the welding operation similar to that disclosed by Peter in U.S. Pat. No. 4,631,685 discussed hereinabove on a standard part manufactured by the present assignee, the finished stack up heights which relate to seal compression may vary within a range of 0.030". Using the system of the preferred embodiment, the variations are reduced to a range of 0.005".
CONCLUSION
While the foregoing details what is felt to be the preferred embodiment of the invention, no material limitations to the scope of the claimed invention is intended. Examples for application of the invention include the preferred embodiment and additionally include control of forces created during a welding process to limit the range of motion of a shaft in an axial direction. In such an instance, the various components intrinsically deform to produce the desired effect accomplished in the preferred embodiment by the gasket. Further, features and design alternatives which would be obvious to one of ordinary skill in the art are considered to be incorporated herein. Previously discussed was the use of pneumatic systems such as disclosed by Peter and sold by numerous vendors. The actual scope of the invention is set forth and particularly described in the claims hereinbelow. | A two stage process of ultrasonic welding is disclosed wherein a first stage determines the amount of displacement required to produce a desired compressive force upon a seal or spring. This displacement is sent to a second stage where the desired displacement is achieved through ultrasonic bonding.
In an alternative embodiment, the first stage determines the amount of displacement required to achieve non-compressive contact between the gasket (seal) and the component. This displacement is summed with an empirically determined displacement required to obtain a desired compressive force upon the gasket. The summed displacement is used as the desired displacement for the second stage. | 1 |
TTITLE OF INVENTION
CROSS-REFERENCE TO RELATED APPLICATION
This application claims priority from PCT patent application Ser. No. PCT/AT03/00278 filed 18 Sep. 2003, which claims priority from Austrian Patent Application A 1420/2002, filed 20 Sep. 2002.
FIELD OF THE INVENTION
The invention concerns a switching power supply to supply a load with a controlled output voltage/output current and having at least one switch controlled by a control circuit, by means of which an input direct voltage is switched, and having a cutoff control for overload conditions.
With respect to the invention, a switching power supply means any kind of power supply which also contains switched, i.e., clocked semiconductor components and which generates a direct or alternating output voltage controlled in the usual manner, from a direct or alternating voltage, usually from a power line alternating voltage, to feed one or more loads. In particular, the invention considers switching power supplies that produce a regulated output direct voltage of 40 volts, for example, from an unregulated alternating voltage of 230/400 volts, for example.
BACKGROUND OF THE INVENTION
In dimensioning of switching power supplies, especially those for industrial controls, calculation of the power consumption is a substantial expense if it is possible at all. Usually, only an estimate is possible, because the peak power consumption depends primarily on the control program that is running. Because of that, power supplies are often massively over-dimensioned, resulting, certainly, in higher costs and greater requirement for space.
Switching power supplies generally have a maximum output power which is, for instance, set at a fixed level by a current limiter, whereby the maximum output power is available as a continuous rating. In so doing, one assumes a maximum ambient temperature. At the state of the art, power supplies are known which can produce output currents or powers greater than the nominal value for short times. For instance, they can produce 3 times the nominal current for 25 ms. It has also become known that power supplies can be built so that they can provide a higher output power, e.g., 10 to 30% higher, at low ambient temperature (“derating”).
Transient overloads can also be supplied by batteries connected in parallel with the output; but that solution is quite disadvantageous because the lifetime and cost of the batteries must be considered, and a separate cutoff device to protect against deep discharge is also necessary, such as a special load circuit; and they have substantial volume and weight, aside from the cost.
The fundamental consideration of thermal capacities for fused supply of electrical loads is often recognized and is already accomplished in principle by fuses with slow response adapted to the load. For example, U.S. Pat. No. 5,283,708 A shows an electronic protection for an electrical motor connected to a three-phase line, which is to be protected against long-term load above the nominal load. In this system the current temperature of the motor can be calculated and applied for switching the motor off.
However, the problem on which the invention is based is not protection of a load and consideration of its characteristics, but provision of a switching power supply at a favorable price.
Then one objective of the invention is provision of a switching power supply with which unnecessarily high costs due to overdimensioning can be avoided and, in particular, intelligent adaptation to the existing situation, especially the load and temperature situation, is possible.
This problem is solved with a switching power supply of the type stated initially, in which, according to the invention, there is a control in which a thermal model is implemented, by means of which the temperature of at least one part can be calculated or estimated, whereby a load-dependent current value is made available to the thermal model as an electrical quantity, and the control is directed to producing at least one limiting signal when a limiting value that can be preset is reached, or a function of multiple limits, which limiting signal can be utilized in the sense of an interruption for temperature reduction, and at least one limiting signal can be sent to the control circuit, which acts on the control circuit in the sense of temperature reduction and thus power reduction.
Due to the invention, it is possible to provide a switching power supply which has only a relatively small structural size and lower costs than the usual power supplies, because it is dimensioned only for the average power consumption. In practice, one can actually reduce the dimensioning to about half the nominal power. The only added costs are those concerning the temperature monitoring.
In one practical variant it is provided that a limiting signal is used to cut off the power supply on the primary and secondary sides.
It is particularly convenient for a limiting signal to be used to control a cooling/ventilating device. In that way it is possible to prevent, or at least to delay, cutting off the power supply in the case of a transient overload.
In many cases it is desirable to use a limiting signal as an alarm signal because the user can take appropriate steps to avoid or reduce damage.
In preferred variants, it is provided that there is at least one temperature sensor to determine temperatures relevant to/for the power supply, whereby the signal from at least one temperature sensor can be used in the thermal model. In contrast to other operating parameter values, the temperature values are of direct and clear importance for an overload state of the power supply. It can be appropriate, if a temperature sensor is provided for the ambient temperature for the power supply or if a temperature sensor is provided to determine the temperature of a semiconductor component and/or its thermally relevant environment, or if a temperature sensor is provided to determine the temperature of a transformer and/or its thermally relevant environment.
On the other hand, it is appropriate in many cases if at least the output current from the power supply is provided to the thermal model as an electrical quantity, or if the primary current is provided to the thermal model as an electrical quantity. The thermal model can, from such current values, make an estimate of, for example, the chip temperature of power semiconductors.
In another variant, it can be provided for the thermal model to contain stored thermal time constants of individual parts which are taken into consideration in the calculation/estimation of component temperatures. In this way, the delay between an actual semiconductor (chip) temperature and, for instance, the housing or heat sink temperature, which is often substantial, can be taken into consideration. Here it is particularly effective if the thermal model is directed at continuously calculating the temperatures of components, considering the stored time constants.
Another variant, which can be accomplished simply, is characterized in that the thermal model contains a list of possible combinations of assignments of operating parameter values and limiting signals and the control circuit is aimed at selecting and outputting at least one limiting signal corresponding to measurements from this list.
Designs in which the control system contains at least one digital processor are particularly capable.
On the other hand, it is possible for the control system to be designed at least in part as an analog system. One can construct a thermal model, especially a simplified one, from operational amplifiers, resistances and capacitors.
BRIEF DESCRIPTION OF THE DRAWINGS
The invention, and other advantages, are explained in more detail in the following by means of embodiments clarified in the drawing. In the drawing,
FIG. 1 shows the basic circuit diagram of a power supply designed according to the invention as a switching converter, and
FIG. 2 shows another possible embodiment, also in a basic circuit diagram.
DETAILED DESCRIPTION OF THE INVENTION
As shown in FIG. 1 , an input voltage U E is rectified by a rectifier D 1 and the rectified voltage U ZK , applied to a capacitor C E , is led through a controlled switch to the primary winding WP of a transformer UET. A sensor resistance R S is in series with the controlled switch to determine the primary current.
The controlled switch S is controlled by a control circuit AST, which provides a signal, pulse-width-modulated in the usual manner, of constant or even variable frequency. The control circuit is supplied with a voltage U V from an auxiliary winding WH and an auxiliary rectifier D 2 . The voltage is applied to a capacitor C 4 . A relatively high-resistance resistor RV to which the voltage U ZK is applied serves for starting the circuit.
At the secondary side, the voltage on a secondary winding WS is rectified, using, for instance, diodes D 3 and D 4 and an inductance L, with the converter, in this case, being built on the flux converter principle. Here it should be noted that, obviously, flux converters or mixed converter types can also be used in connection with the invention.
The rectified output voltage U A is applied to a capacitor C A . A voltage detection circuit UEK on the secondary side provides information about the output voltage through an optocoupler OKO to the control circuit AST, so that output voltage can be regulated at a fixed value. Similarly, but not shown here, it is possible to provide information about the output current I A to the control circuit AST if, for example, a secondary current regulation is desired.
In the present case the output current I A is determined by a series resistance R D and supplied to a current detection unit IAK of a control STE. Other possibilities for current measurement, as through a current transformer, are also possible.
The sensor resistance R S at the primary side provides the course of the primary current for the control circuit AST in the known manner, and also provides a signal to a current detection unit IEK of the control STE. This STE circuit contains a thermal model THM which, in the present case, contains information about the output current and about the input current.
The thermal model THM calculates the temperatures of critical components, such as the diodes D 3 and D 4 or the switch S, or estimates those temperatures, from the values of the output current or, optionally, the input current. The thermal time constants, details of the heat sink, etc., are also considered in the thermal model THM. The temperatures in the windings of the transformer UET can, for instance, also be calculated/estimated using the thermal model THM, along with the semiconductor temperatures.
As soon as the circuit, using the thermal model, establishes that temperature limits, which can be specified, or critical combinations of such limits, have been reached, it produces at least one limit signal, in the present case, through an interface INT. Limit signals that are output can, also in different sequences, initiate various processes. For example, a signal 1st can first be output to a blower control LST, turning on or increasing the speed of the motor MOT of a blower, so as to force cooling of the temperature of certain components or the interior of a power supply housing by means of this blower. To the extent that this measure itself results in the temperatures or combinations of temperatures to drop below their critical values, nothing else will happen, or the blower control will be turned off again after some time. Even at the time when the blower control is activated, of course, an alarm signal asa can be output, to a control computer, for instance, or to a warning lamp. In case starting the blower has no effect, then a shutdown signal abs can be output to the circuit AST which lowers the power of the switching power supply, to stand-by operation, for instance, until the overload situation is eliminated.
It can be convenient for the user for the STE circuit also to contain a memory SPE together with a display ANZ, which displays a record of the current I particularly before the shutdown time. It can, for example, display a period of time t of 10 to 100 seconds. The user can decide about possible causes for the shutdown from this display.
The embodiment shown in FIG. 2 corresponds to its design as a flux converter to that shown in FIG. 1 . It differs from the embodiment of FIG. 1 , though, in that the thermal model THM is not based on electrical quantities of the power supply, but on temperatures measured with temperature sensors assigned to different components of the power supply.
In particular a temperature sensor TS 1 , which determines the room temperature or the ambient temperature of the power supply is provided next. Here another temperature sensor TS 2 measures the temperature of a heat sink KK of the primary switch S. A temperature sensor TS 3 measures the temperature of a heat sink KK which is common to the secondary diodes D 3 and D 4 , and a temperature sensor TS 4 which has, for instance, a thermally conductive link to the core of transformer UET, is assigned to the transformer UET.
Using the temperatures determined, the control, by means of the thermal model, can calculate or estimate the actual critical temperature value, such as the chip temperature of a semiconductor or the winding temperature of the transformer, and then output the previously discussed limiting signal or other appropriate signals if the limiting value, which can be specified in advance, or a critical combination of such limits, is reached.
With respect to temperature measurement, it must be noted that the actual critical temperatures can never be measured with reasonable cost, especially the temperatures on the chip of a semiconductor. It would be necessary to drill down into the various components, posing special requirements for insulation of the temperature sensors. Therefore temperatures related to the particular components are measured, such as the housing temperature of a semiconductor or the temperature at a certain point on a semiconductor heat sink. Even with a transformer, it can often be difficult to measure the winding temperature or the core temperature, so that, for example, one measures the circuit board temperature at the electrical connections to a transformer. The thermal model includes all those parameters needed to be able to determine the relevant, i.e., the critical, temperatures reliably and time-dependently, from the temperatures actually measured. In this respect one should note the heat transfer resistance and the thermal time constants. It is also known that both the load current and the input voltage are important for heating of the transformer; the load current because of the copper losses, and the input voltage because of the capacitive losses linked with increasing input voltage. This can also be taken into consideration, and it is shown in FIG. 2 that the input voltage and the input current are provided to the thermal model as parameters.
For example, in order to be able to determine the actual diode temperature of one of diodes D 3 or D 4 accurately, a signal derived from the known load current is added to the actually measured heat sink temperature. For a particular embodiment, for instance, each ampere of load current can have the effect of adding a signal to the heat sink measurement that makes that measurement appear two degrees Kelvin higher. Than can be taken into consideration appropriately for the transformer.
It should also be noted that other combinations aside from the possibilities shown in FIGS. 1 and 2 for determining operating parameters can also be used. For example, one can provide all the electrical quantities from the primary and secondary sides to the thermal model, and even a larger number of temperature values. Of course, one must make an appropriate economic choice according to the situation, considering, for instance, whether the optocoupler or other isolating measures which increase the cost of the design are necessary for the transmission.
In general, the control STE or the thermal model THM will contain a digital processor DSP, which, for instance, makes it possible to include permanently the heating of one or more parts. To be sure, that involves relatively high computing capability, as the thermal model must be updated often, e.g., several times per second.
Another possibility is to establish a list of the possible combinations of possible operating parameter values in an EPROM. Then the processor need only find the appropriate parameter list and carry out the command stored there. Such a list can, for example, contain a hundred “IF” instructions, such as the following:
“IF” ambient temperature <20° C. “AND” load current<1.2 i nominal , “THEN” warning signal in 32 seconds.
Control with the thermal model is fundamentally not tied to a digital processor DSP. Rather, the entire thermal model can also be simulated in analog form with operational amplifiers, capacitors and resistors. In general, though, that is more expensive and is not favorable with the desirable processors now available. | A switching power supply having at least one switch (S) controlled by a control circuit (AST), by means of which an input direct voltage (U V ) is switched, whereby a thermal model (THM) is implemented in a control (STE), by means of which the temperature of at least one component (S; D 3 , D 4 , UET) can be calculated or estimated, and at least one current value that is load-dependent is made available as an electrical quantity to the thermal model, the control (STE) is directed at outputting at least one limiting signal (abs, ala) when a limiting value or a function of multiple limiting values depending on calculated or estimated temperature values is reached, which is usable in the sense of an action to reduce temperature, and which produces at least one limiting signal (abs) to the control circuit in the sense of a temperature reduction and thus a power reduction. | 7 |
BACKGROUND OF THE INVENTION
1. Field of the Invention
The present invention relates to a particle size distribution measuring apparatus which detects a diffraction/scattering light generated by irradiating a laser beam onto a dispersing particle group, and measures a particle (grain) size distribution of the particle group on the basis of an intensity signal of the scattered light obtained by the detection.
2. Description of Related Art
In a particle size distribution measuring apparatus using a diffraction or scattering phenomenon of light by particles, an intensity distribution of diffraction light or scattering light, that is, a relationship between a diffraction or scattering angle and a light intensity is measured, and then, this measured result is subjected to operational processing based on a Fraunhofer diffraction theory or Mie scattering theory, and thereby, a particle size distribution of a sample particle is calculated (computed). The aforesaid particle size distribution measuring apparatus has been used for research and development of raw materials in a mining industrial field such as the cement or ceramic industry, and in ceramics, in particular.
In the development of new materials in the ceramic and polymer fields, a demand has been recently made to measure micro particles in a sub-micron region, and therefore, efforts have been made to develop instruments which can measure not only relatively large particles, but also particles in a sub-micron region.
An example of a particle size distribution measuring apparatus is disclosed in Japanese Examined Patent Publication (Kokoku) No. 6-43950. FIG. 4 is a view schematically showing a construction of the particle size distribution measuring apparatus disclosed in the above publication. In FIG. 4, a reference numeral 41 denotes a sample cell comprising a transparent container which contains a liquid (hereinafter, referred to as a sample solution) 42 prepared by dispersing a particle group of a target specimen for measurement in a medium liquid. A laser beam source 43 which is located on one side (rear side) of the cell 41 provides an enlarged parallel laser beam 44 from a beam expander (not shown) so as to irradiate the cell 41 .
A collective (condenser) lens 45 is located on the other side (front side) of the cell 41 , and a ring detector 46 is arranged on a focal position of the collective lens 41 . The ring detector 46 is constructed in such a manner that a plurality of photo-sensors having a ring or semi-ring like light receiving surface having mutually different radius are coaxially arranged around an optical axis of the collective lens 45 . Further, the ring detector 46 receives light scattered/diffracted at a relatively small angle off of the optical axis of the laser beam 44 which has been diffracted or scattered by the particles in the cell 41 for each scattering angle, and then, measures each respective light intensity.
An optical detector group 47 for wide-angle scattering light detects each light scattered/diffracted at a relatively large angle of the laser beam 44 which has been diffracted or scattered by the particles in the cell 41 for each scattering angle. Further, the optical detector group 47 for wide-angle scattering light is composed of the collective lens 45 and a plurality of photo-sensors 48 to 53 which are located at an angle different from the ring detector 46 , and can detect a wide-angle scattering light which exceeds a predetermined angle by particles in the cell 41 , in accordance with each located angle. More specifically, the photo-sensors 48 to 51 detect a forward scattering light, the photo-sensor 52 detects a side scattering light, and the photo-sensor 53 detects a backward scattering light.
A reference numeral 54 denotes a pre-amplifier for amplifying an output of the photo-sensors constituting the above ring detector 46 , reference numerals 55 to 58 individually denote pre-amplifiers for amplifying each output of the photo-sensors 48 to 51 for forward scattering light, and reference numerals 59 and 60 individually denote pre-amplifiers for output of the photo-sensor 52 for side scattering light and the photo-sensor 53 for backward scattering light. A multiplexor 61 successively captures each output of the pre-amplifiers 54 to 60 , and successively transmits the output to an A/D converter 62 , and a computer 63 functions as a processor to which an output of the A/D converter 62 is inputted.
The computer 63 stores a program for processing the outputs converted into a digital signal (the digital data relative to light intensity) of the ring detector 46 and photo-sensor 48 to 53 on the basis of a known Fraunhofer diffraction theory or Mie scattering theory and determining a particle size distribution of the particle group.
In the aforesaid particle size distribution measuring apparatus, when sample liquid 42 is contained in the cell 41 , the laser beam 44 is irradiated on the sample cell 41 from the laser beam source 43 and the laser beam 44 is diffracted or scattered by particles contained in the cell 41 . Of the diffraction light or the scattering light, a light having a relatively small scattering angle is imaged on the ring detector 46 by means of the collective lens 45 . In this case, the photo-sensor arranged on the outer peripheral side of the ring detector 46 receives a light having a larger scattering angle while the photo-sensor arranged on an inner peripheral side thereof receives light having a smaller scattering angle. Thus, a light intensity detected by the outer peripheral side photo-sensor reflects a particle quantity having a smaller particle size, and a light intensity detected by the inner peripheral side photo-sensor reflects a quantity of sample particle having a larger particle size. The light intensity detected by each photo-sensor is converted into an analog electric signal, and further, is inputted to the multiplexor 61 via the pre-amplifier 54 .
On the other hand, of the laser beam 44 diffracted or scattered by the particles, a relatively large scattering angle light, which is not converged by the collective lens 45 , is detected by means of the photo-sensors 48 to 53 , and then, the light intensity distribution is measured. In this case, the photo-sensors 48 to 51 for forward scattering light, the photo-sensor 52 for side scattering light and the photo-sensor 53 for backward scattering light, successively detect scattering light from a particle having a small particle (grain) size. A light intensity detected by each of these photo-sensors 48 to 53 is converted into an analog electric signal, and then, is inputted to the multiplexor 61 via pre-amplifiers 55 to 60 .
In the multiplexor 61 , measurement data from the ring detector 46 and photo-sensors 48 to 53 , that is, the analog electric signal is successively captured in a predetermined order. Then, the analog electric signal captured by the multiplexor 61 is made into a serial signal, and is successively converted into a digital signal by means of the A/D converter 62 , and further, is inputted to the computer 63 . The computer 63 processes light intensity data for each scattering angle obtained by each of the ring detector 46 and the photo-sensors 48 to 53 on the basis of a Fraunhofer diffraction theory and a Mie scattering theory.
As seen from the above description, in such a particle size distribution measuring apparatus, the light intensity distribution of the scattering light having a large particle size range is measured by means of the ring detector 46 while the light intensity distribution of the wide-angle scattering light having a small particle size range is measured by means of the photo-sensors 48 to 53 . Then, the outputs of these ring detector 46 and photo-sensors 48 to 53 are processed by means of the computer 63 , so that a particle size distribution of a particle group can be determined over a wide range from a relatively large particle size to a micro particle size.
However, the aforesaid particle size distribution measuring apparatus has the following problem. More specifically, in the particle size distribution measuring apparatus, a parallel beam is used as the laser beam 44 for irradiating the particle group contained in the cell 41 ; therefore, light having a small scattering angle is generated by particles having a relatively large particle size and the light is converged on the ring detector 46 . For this reason, the collective lens 45 must be interposed between the cell 41 and the ring detector 46 . As a result, this arrangement requires a long optical path length from the laser beam source 43 to the ring detector 46 .
Moreover, the aforesaid arrangement of the collective lens 45 is a factor in causing the following problem. More specifically, in order to detect scattering light from a smaller particle (light having a large scattering angle), a plurality of photo-sensors 48 to 53 must be located so as to constitute the optical detector group 47 for wide-angle scattering light. In order to make the wide-angle scattering light incident upon these photo-sensors 48 to 53 , there is a requirement of an accurate positional relationship between the collective lens 45 and the photo-sensors 48 to 53 , in particular, the photo-sensors 48 to 51 for forward scattering light. Thus, in the aforesaid conventional particle size distribution measuring apparatus, an arrangement space must be widened so that the scattering light from the cell 41 can be securely incident upon all of photo-sensors 48 to 53 .
As is evident from the above description, in the conventional particle size distribution measuring apparatus, the parallel laser beam 44 is irradiated on the cell 41 , and the collective lens 45 is interposed between the cell 41 and the ring detector 46 and for this reason the apparatus must be made into a large size.
U.S. Pat. No. 5,737,078 discloses a flow cell for a cytoanalyzer and U.S. Pat. No. 5,796,480 is cited of interest.
The prior art is still seeking to provide an economical and compact portable measuring apparatus.
SUMMARY OF THE INVENTION
The present invention has been made taking the aforesaid problems in the prior art into consideration. It is, therefore, an object of the present invention to provide a small and compact particle size distribution measuring apparatus which can securely measure a particle size distribution of particles over a wide range from a micro particle size to a large particle size.
To achieve the above object, the present invention provides a particle size distribution measuring apparatus which is constructed in such a manner that diffracted/scattered light generated by irradiating a laser beam from a laser light source on a particle group dispersed in a sample cell, a light intensity of a laser beam having a small scattering angle is detected by means of a ring detector for each scattering angle. The ring detector includes a plurality of concentric channels of photo detective material. A light intensity of a laser beam having a large scattering angle of the diffracted/scattered light is detected by means of a plurality of photo-sensors formed into an array, and thus, a particle size distribution of the particle group is measured on the basis of a scattering light intensity signal from the ring detector and the photo-sensors with a collective lens being interposed between the laser light source and the cell so that a laser beam converged by the condenser lens is irradiated on the particle group.
In the aforesaid particle size distribution measuring apparatus, the collective lens is interposed between the laser light source and the cell, and the laser beam is converged by the condenser lens to irradiated the particle group. It is possible to collect light having a small scattering angle generated by the particles having a relatively large particle size onto the ring detector without interposing the condenser lens between the cell and the ring detector. Further, it is possible to make a shorter optical path length from the laser beam source to the ring detector as compared with the case where the parallel beam is irradiated to the particle group in the sample cell. Furthermore, the condenser lens is not interposed between the cell and the ring detector; therefore, it is possible to sufficiently secure an optical path of the scattering light from cell, and to arbitrarily arrange photo-sensors on a position equivalent to respective scattering angles. Therefore, the construction of the particle size distribution measuring apparatus can be simplified and a small-size and compact particle size distribution measuring apparatus can be obtained.
In the aforesaid particle size distribution measuring apparatus, the plurality of photo-sensors may be individually located on a substrate such as an electric circuit board, and these photo-sensors may be collectively located on a single electric circuit board.
BRIEF DESCRIPTION OF THE DRAWINGS
The general purpose of this invention, as well as a preferred mode of use, its objects and advantages will best be understood by reference to the following detailed description of an illustrative embodiment with reference to the accompanying drawings in which like reference numerals designate like parts throughout the figures thereof, and wherein:
FIG. 1 is a view schematically showing a construction of a particle size distribution measuring apparatus according to a first embodiment of the present invention;
FIG. 2 is a view schematically showing a construction of a particle size distribution measuring apparatus according to a second embodiment of the present invention;
FIG. 3 is a view schematically showing a construction of a particle size distribution measuring apparatus according to a third embodiment of the present invention; and
FIG. 4 is a view schematically showing a construction of a conventional particle size distribution measuring apparatus.
DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS
The following description is provided to enable any person skilled in the art to make and use the invention and sets forth the best modes contemplated by the inventors of carrying out their invention. Various modifications, however, will remain readily apparent to those skilled in the art, since the general principles of the present invention have been defined herein specifically to provide a compact particle size distribution measuring apparatus with a unitary substrate for supporting an array of photo detector and associated circuitry.
In the Figures, like elements will have the same reference numbers.
FIG. 1 schematically shows a construction of a particle size distribution measuring apparatus according to one embodiment of the present invention. In FIG. 1, a reference numeral 1 denotes a cell comprising a transparent container which contains a liquid, thereinafter, referred to as a sample solution 2 prepared by dispersing a particle group of a target for measurement in a medium liquid. An optical path direction length or optical path length D is set shorter than that generally set in a type of conventional apparatus. A laser beam or light source 3 , which is located on one side of a rear side of the cell 1 emits parallel laser light. A condenser or collective lens 4 is interposed between the laser light source 3 and the cell 1 . A laser light or laser beam emitted from the laser light source 3 is made into a converged light hereinafter, referred to as a converged laser beam 5 so as to irradiate the sample solution 2 in the cell 1 .
A ring detector 6 is located on the other side or front side of the cell 1 , and is arranged at a position where the converged laser beam 5 , transmitted through the cell, 1 is focused. The ring detector 6 may be constructed in such a manner that a plurality of photo-sensors having a ring, semi-ring or quarter-ring light receiving surface or channel having mutually different radius are coaxially arranged around an optical axis of the condenser lens 4 . Further, the ring detector 6 receives a light scattered/diffracted at a relatively small angle of the converged laser beam 5 diffracted or scattered by the particles in the cell 1 for each scattering angle, and then, measures each light intensity. Consequently, there is no necessity to use a lens for converging the scattered laser beam on the other side of the cell 1 from the laser light source 3 . An example of a possible ring detector is shown in U.S. Pat. No. 5,936,729 which is incorporated herein by reference. A pre-amplifier 7 amplifies each output of the photo-sensors constituting the ring detector 6 .
Moreover, an optical detector group 8 for measuring wide-angle scattering light is located in the vicinity of the cell 1 . The optical detector group 8 for wide-angle scattering light detects each light scattered/diffracted at a relatively large angle of the converged laser beam 5 diffracted or scattered by the particles in the cell 1 for each scattering angle. Further, the optical detector group 8 for wide-angle scattering light is composed of a plurality of photo-sensors 9 to 14 which are located at an angle different from the ring detector 6 , and can detect a predetermined angle of scattering light which exceeds a predetermined angle by particles in the cell 1 , in accordance with each located angle. More specifically, the photo-sensors 9 to 12 detect a forward scattering light, the photo-sensor 13 detects a side scattering light, and the photo-sensor 14 detects a backward scattering light. A reference numeral 15 collectively denotes a substrate such as an electric circuit board which holds each of photo-sensors 9 to 14 at a predetermined angle and includes a pre-amplifier.
A reference numeral 16 denotes a multiplexor which successively captures each output of the pre-amplifier 7 of the electric circuit board 15 , and then, successively transmits the output to an A/D converter 17 . A computer 18 functions as a processor to which an output of the A/D converter 17 is inputted. The computer 18 stores a program for processing the outputs converted into a digital signal (the digital data relative to light intensity) of the ring detector 6 and photo-sensors 9 to 14 on the basis of a Fraunhofer diffraction theory or Mie scattering theory and determining a particle size distribution of the particle group. A color display 19 can display the processed results.
In the particle size distribution measuring apparatus constructed as described above, where the sample solution 2 is contained in the cell 1 and the laser beam is irradiated from the laser light source 3 , the laser beam is converged by means of the condenser lens 4 so as to be made into a converged laser beam 5 , and then, the converged laser beam 5 is irradiated to the sample solution 2 in the cell 1 . Then, the converged laser beam 5 is diffracted or scattered by particles contained in the cell 1 . Of the diffraction light or the scattering light, a light having a relatively small scattering angle is imaged on the ring detector 6 . In this case, the photo-sensor arranged on the outer peripheral side of the ring detector 6 receives a light having a larger scattering angle; on the other hand, the photo-sensor arranged on the inner peripheral side thereof receives a light having a smaller scattering angle. Thus, a light intensity detected by the outer peripheral side photo-sensor represents a particle quantity having a smaller particle size, and a light intensity detected by the inner peripheral side photo-sensor represents a quantity of sample particle having a larger particle size. The light intensity detected by each photo-sensor is converted into an analog electric signal, and further, is inputted to the multiplexor 16 via the pre-amplifier 7 .
On the other hand, of the converged laser beam 5 diffracted or scattered by the particles, a relatively large scattering angle light is detected by means of the optical detector group 8 for wide-angle scattering light, and then, the light intensity distribution is measured. In this case, the photo-sensors 9 to 12 for forward scattering light, the photo-sensor 13 for side scattering light and the photo-sensor 14 for backward scattering light, in this order, successively detects a scattering light from a particle having a small particle (grain) size. A light intensity detected by each of these photo-sensors 9 to 14 is converted into an analog electric signal, and then, is inputted to the multiplexor 16 via pre-amplifiers located on the electric circuit board 15 .
In the multiplexor 16 , measurement data from the ring detector 6 and photo-sensors 9 to 14 , that is, the analog electric signal is successively captured in the predetermined order. Then the analog electric signal captured by the multiplexor 16 is made into a serial signal, and is successively converted into a digital signal by means of the A/D converter 17 , and further, is inputted to the computer 18 .
The computer 18 processes light intensity data for each scattering angle obtained by each of the ring detector 6 and the photo-sensors 9 to 14 on the basis of a Fraunhofer diffraction theory and a Mie scattering theory.
As seen from the above description, in the particle size distribution measuring apparatus, the light intensity distribution of the scattering light having a large particle size range is measured by means of the ring detector 6 and the light intensity distribution of the wide-angle scattering light having a small particle size range is measured by means of the photo-sensors 9 to 14 . Then, the outputs of the ring detector 6 and photo-sensors 9 to 14 are processed by means of the computer 18 , so that a particle size distribution of the particle group can be collectively determined over a wide range from a relatively large particle size to a micro particle size.
In the above particle size distribution measuring apparatus, the collective lens 4 is interposed between the laser beam source 3 and the cell 1 , and the laser beam 5 , converged by the collective lens 4 , is irradiated to the particle group. Thus, unlike the conventional case, it is possible to collect light having a small scattering angle generated in particles having a relatively large particle size onto the ring detector 6 without interposing the collective lens between the cell 1 and the ring detector 6 . Further, it is possible to make shorter the optical path length from the laser beam source 3 to the ring detector 6 as compared with the case where a parallel beam is irradiated to the particle group in the cell. Furthermore, the collective lens is not interposed between the cell 1 and the ring detector 6 , therefore, it is possible to sufficiently secure a desired optical path of the scattering light from cell 1 to the optical detector group 8 for wide-angle scattering light from cell 1 to the optical detector group 8 for wide-angle scattering light, and to arbitrarily arrange photo-sensors 9 to 14 on a position equivalent to a scattering angle. Therefore, it is possible to simplify the construction of a particle size distribution measuring apparatus, and to obtain a small-size and compact particle size distribution measuring apparatus.
The present invention is not limited to the above embodiment, and various modifications can be carried out. More specifically, FIG. 2 shows a second schedule embodiment of the present invention with a quarter-ring detector 6 . In this second embodiment, the photo-sensors 9 to 14 constituting the optical detector group for wide-angle scattering light can be arranged on a single substrate, such as an electric circuit board 20 with each sensor at a predetermined angle. Although it is not illustrated, a pre-amplifier is also located on the electric circuit board 20 so as to correspond to each of the photo-sensors 9 to 14 . An output of the electric circuit board 20 is inputted to the multiplexor 16 .
According to the above second embodiment, there is the following effect in addition to the effect of the aforesaid first embodiment. More specifically, there is no need of providing an electric circuit board 15 for each of the photo-sensors 9 to 14 ; therefore, a construction of an optical system becomes simple, and it is easy to construct and arrange the optical detector group 8 for wide-angle scattering light. As a result, it is possible to make the whole of the apparatus into a small size, and to achieve a reduction in both individual part cost and manufacture cost.
FIG. 3 shows a third embodiment of the present invention. In this third embodiment, the electric circuit board 20 is provided with a pre-amplifier section 21 which amplifies an output of each of the ring detector 6 and the photo-sensors 9 to 14 , a multiplexor 22 which successively captures an output of the pre-amplifier 21 and outputs it to the computer 18 , and an A/D converter 23 which converts an analog signal successively outputted from the multiplexor 22 into a digital signal. According to this third embodiment, there is the following effect in addition to the effect of the above second embodiment. More specifically, it is possible to provide a relatively short signal line from the photo-sensors 9 to 14 , and to prevent noise from being mixed with the signals.
In the above embodiments, the sample solution 2 has been contained in the sample cell 1 . The cell is not limited to the form described in the above embodiments, and a so-called flow cell where a stream of material flows pass the sampling site may be used. Moreover, as a target for measurement, in addition to particles in a liquid, a powder or particle dispersed in a gas or solid may be used.
In the present invention, the condenser lens is interposed between the laser light source and the sample cell, and a laser beam, converged by the condenser lens, is irradiated to the particle group. Thus, a light having a small scattering angle generated in the particles having a relatively large particle size can be converged onto the ring detector, and the optical path length from the laser beam source to the ring detector can be made short as compared with the case where a parallel laser beam is irradiated to the particle group in the cell. Further, there is no need of interposing the condenser lens between the cell and the ring detectors; therefore, it is possible to sufficiently secure a desirable optical path of the scattering light from the cell, and to selectively arrange the photo-sensor on a position equivalent to the scattering angle.
Accordingly, the construction of the particle size distribution measuring apparatus can be simplified to provide a small and compact size apparatus and it is possible to securely measure a particle size distribution of particles having a range from a micro particle size to a large particle size.
Those skilled in the art will appreciate that various adaptations and modifications of the just-described preferred embodiments can be configured without departing from the scope and spirit of the invention. Therefore, it is to be understood that within the scope of the appended claims, the invention may be practiced other than as specifically described herein. | A particle size distribution measuring apparatus includes a source of laser light for providing a laser beam to a sample cell that can hold a sample to be measured. A condenser lens converges the laser beam towards the sample cell along an optical axis. The position on the other side of the sample cell is a ring detector unit that can be aligned with the optical axis to measure light intensity at relatively small scattering angles from contact with particles in the sample cell. An array of detectors can be operatively positioned on a substrate with appropriate amplifying multiplying and analog to digital conversion capacity for measuring light intensity at relatively large scatter angles. The outputs of the ring detector unit and the array of detectors can be used to determine the particle size distribution of particles in the sample. | 6 |
TECHNICAL FIELD
[0001] The present invention relates to fuel cells and is particularly concerned with the fuel supply to a fuel cell electrical power generating system.
BACKGROUND ART
[0002] Fuel cells convert gaseous fuels (such as hydrogen, natural gas and gasified coal) via an electrochemical process directly into electricity. A fuel cell continuously produces power when supplied with fuel and oxidant, normally air. A typical fuel cell consists of an electrolyte (ionic conductor, H + , O 2− , CO 3 2− etc.) in contact with two electrodes (mainly electronic conductors). On shorting the cell through an external load, fuel oxidises at the anode resulting in the release of electrons which flow through the external load and reduce oxygen at the cathode. The charge flow in the external circuit is balanced by ionic current flows within the electrolyte. Thus, at the cathode oxygen from the air or other oxidant is dissociated and converted to oxygen ions which migrate through the electrolyte membrane and react with the fuel at the anode/electrolyte interface. The voltage from a single cell under load conditions is in the vicinity of 0.6 to 1.0 V DC and current densities in the range 100 to 1000 mAcm −2 can be achieved.
[0003] Several different types of fuel cells have been proposed. Amongst these, the solid oxide fuel cell (SOFC) is regarded as the most efficient and versatile power generation system, in particular for dispersed power generation, with low pollution, high efficiency, high power density and fuel flexibility. SOFC's operate at elevated temperatures, for example 700-1000° C. Other fuel cells which operate at elevated temperatures include the molten carbonate fuel cell requiring a minimum temperature of 650° C. However, SOFC's are the primary interest for the invention and further discussion herein will be mainly directed to these without intending to be limited in any way.
[0004] Numerous SOFC configurations are under development, including the tubular, the monolithic and the planar design. The planar or flat plate design is the most widely investigated. Single planar SOFC's are connected via interconnects or gas separators to form multi-cell units, sometimes termed fuel cell stacks. Gas flow paths are provided between the gas separators and respective electrodes, for example by providing gas flow channels in the gas separators. In a fuel cell stack the components—electrolyte/electrode laminates and gas separator plates—are fabricated individually and then stacked together. With this arrangement, external and internal co-flow, counter-flow and cross-flow manifolding options are possible for the gaseous fuel and oxidant.
[0005] Traditionally hydrogen, usually moistened with steam, has been used as a fuel cell fuel. However, in order to be economically viable the fuel must be as cheap as possible. One relatively cheap source of hydrogen is natural gas, primarily methane with a small proportion of heavy hydrocarbons (C 2+ ). Natural gas is commonly converted to hydrogen in a steam reforming reaction, but the reaction is endothermic and, because of the stability of methane, requires a reforming temperature of at least about 650° C. for substantial conversion and a higher temperature for complete conversion. While high temperature fuel cell systems produce heat which must be removed, heat exchangers capable of transferring thermal energy at the required level of at least about 650° C. from the fuel cells to a steam reformer are expensive. Thus, hydrogen produced by steam reforming natural gas may not be a cheap source of fuel.
[0006] One proposal of a fuel cell electricity generation process in which a hydrocarbon fuel is converted to a fuel cell fuel stream including hydrogen in a steam pre-reformer is disclosed in EP-A-0435724. The temperature in the pre-reformer is described as 700 to 850° C. with a resultant product-gas composition of 65-80 vol % H 2 , 5-20 vol % CO, and 5-25 vol % CO 2 .
[0007] Another such proposal is disclosed in U.S. Pat. No. 5,302,470 in which the steam pre-reforming reaction is said to be carried out under similar conditions to those of known steam reforming reactions: for example, an inlet temperature of about 450 to 650° C., an outlet temperature of about 650 to 900° C., and a pressure of about 0 to 10 kg/cm 2 .G to produce a fuel cell fuel stream which is composed mainly of hydrogen and is fed to the fuel cell anode via a carbon monoxide shift converter.
[0008] Hydrocarbon fuels suggested for use in the above two proposals include, in addition to natural gas, methanol, kerosene, naphtha, LPG and town gas.
[0009] It has been proposed to alleviate the aforementioned problem of the cost of substantially complete steam pre-reforming of methane by using natural gas as a fuel source for a high temperature planar fuel cell stack and subjecting the natural gas to steam reforming within the stack, at a temperature of at least about 650° C., using catalytically active anodes. However, this arrangement can lead to carbon disposition problems on the anode from C 2+ hydrocarbons and is not suited to other higher hydrocarbon fuels for this reason. Furthermore, given the endothermic nature of the methane steam reforming reaction, too much methane in the fuel stream can lead to excessive cooling of the fuel cell stack. To alleviate this problem the fuel stream has been restricted to a maximum of about 25% methane (on a wet basis) with the natural gas being subjected to partial steam pre-reforming at elevated temperatures approaching 700° C. upstream of the fuel cell stack.
[0010] Another process for producing electricity in a fuel cell from hydrocarbon fuels such as gasified coal, natural gas, propane, naphtha or other light hydrocarbons, kerosene, diesel or fuel oil is described in EP-A-0673074. As described in that specification, the process involves steam pre-reforming approximately 5 to 20% of the hydrocarbon fuel at a temperature of at least 500° C. after start-up to convert ethane and higher hydrocarbons in that fraction to methane, hydrogen and oxides of carbon and to achieve a measure of methane pre-reforming in that fraction to oxides of carbon and hydrogen. Steam pre-reforming at this lower temperature alleviates carbon deposition in the pre-reformer. The hydrocarbon fuel with the steam pre-reformed fraction is then supplied to fuel inlet passages of the fuel cell stack which are coated with or contain a catalyst for steam reforming of the methane and remaining hydrocarbon fuel at 700-800° C. into hydrogen and oxides of carbon which are supplied to the anodes in the fuel cell stack.
[0011] Indirect internal steam reforming of the remaining hydrocarbon fuel within the fuel inlet passages is said to allow the use of reforming catalysts within the fuel inlet passages which are less likely to produce coking or carbon deposits from the internal steam reforming of the higher hydrocarbons than nickel cermet anodes. It is believed that steam pre-reforming of the hydrocarbon fuel in the described temperature range is restricted to 5 to 20% of the fuel in order to relatively increase the level of hydrogen in the fuel stream to the fuel cell stack and thereby alleviate carbon deposition when the fuel is internally reformed in the stack.
[0012] An alternative approach to providing a fuel stream for a fuel cell in which the proportion of methane derived from a higher carbon (C 2+ ) hydrocarbon fuel is increased is disclosed in our International Patent Application No PCT/AU00/00974 filed 16 Aug., 2000, the contents of which are incorporated herein by reference. In this proposal all the fuel is reacted with steam in a steam pre-reformer at a temperature in the pre-reformer of no greater than 500° C. to produce a fuel stream including hydrogen and no less than about 20% by volume methane (measured on a wet basis). The fuel stream is reacted at the anode of the fuel cell to produce electricity when an oxidant such as air is reacted at the fuel cell cathode.
[0013] By this proposal, any of a wide range of higher hydrocarbon fuels may be used, and the lower pre-reforming temperature of no greater than 500° C. not only results in a greater proportion of methane being produced but also enables a simpler and therefore cheaper pre-reformer system to be adopted.
[0014] It has been found advantageous to increase the proportion of methane in the fuel stream to a high temperature fuel cell in which the methane is internally reformed on the anode because consumption of the heat released from the exothermic fuel cell reaction by the endothermic steam/methane internal reforming reaction leads to better thermal management of the fuel cell. In turn this provides improved fuel cell efficiency because of reduced parasitic losses associated with cooling strategies otherwise required for the fuel cell. Any additional methane content in the fuel stream replacing hydrogen means more internal reforming and therefore lessened requirement for cell cooling which is normally achieved by flowing excess air through the cathode side of the fuel cell. However, a disadvantage of the proposal in PCT/AU00/00974 is that it is seeking to balance the production of methane in the fuel stream against the desire to pre-reform all the higher hydrocarbons in the initial fuel. Temperatures towards the upper limit of the range (no greater than 500° C.) defined in that application, or higher, may be required for full conversion of the higher hydrocarbons (because of practical limitations imposed by reaction kinetics and/or catalyst effectiveness), but thermodynamics require a temperature lower than this to optimize the proportion of methane in the fuel stream. The present invention seeks to alleviate this disadvantage.
SUMMARY OF THE INVENTION
[0015] Accordingly, the present invention provides process for producing electricity in a fuel cell which comprises:
a) pre-reforming a higher carbon (C 2+ ) hydrocarbon fuel in a pre-reformer under conditions effective to achieve substantially complete conversion of higher carbon (C 2+ ) hydrocarbons to produce a pre-reformed fuel stream; b) subjecting the pre-reformed fuel stream to methanation under conditions effective to produce a fuel stream having an increased concentration of methane relative to the pre-reformed fuel stream; and c) supplying the fuel stream and an oxidant to a high temperature fuel cell in which methane is reformed and electricity is produced by reacting the fuel stream at an anode of the fuel cell and reacting the oxidant at a cathode of the fuel cell.
[0019] In the process of the invention the necessary conditions to achieve substantially complete conversion of higher carbon hydrocarbons in the fuel may yield a methane lean (less than 20% by volume methane measured on a wet basis) fuel stream (mixture) by thermodynamically and/or kinetically favouring formation of hydrogen and a carbon oxide over formation of methane. Such thermodynamic and/or kinetic limitations may even convert some or all of the methane originally present in the higher carbon hydrocarbon fuel into hydrogen and a carbon oxide. However, it is desirable to include methane in the fuel for the fuel cell for internal reforming at the anode. In the process of the present invention the methane content of the fuel is subsequently enhanced by use of a methanator downstream of the pre-reformer, and the methanation is operated under conditions effective to produce a methane enriched fuel stream for the fuel cell. The crux of the invention resides in operating the pre-reformer in such a way to achieve the desired level of conversion of higher hydrocarbons and using a methanator to boost the methane content of the fuel prior to feeding it to the fuel cell. Use of the methanator may remedy any loss in methane concentration in the fuel following pre-reforming.
[0020] Typically, the temperature of the pre-reformer operation is adjusted to achieve the desired conversion though other parameters may also be varied. Similarly, it is the temperature of the methanator that is usually adjusted to provide the desired control of the methanation reaction. Usually, the methanator is operated at a temperature of from 250 to 450° C.
[0021] In one embodiment the higher carbon hydrocarbon fuel is reacted with steam in a steam pre-reformer to produce a pre-reformed fuel mixture comprising methane, hydrogen and carbon oxides. In this embodiment the steam pre-reformer is usually operated at a temperature of at least 300° C. Thus, in this embodiment the present invention provides a process for producing electricity in a fuel cell which comprises reacting a higher carbon (C 2+ ) hydrocarbon fuel in a steam pre-reformer at a temperature in the pre-reformer of at least 300° C. to produce a mixture of methane, hydrogen and oxides of carbon, subjecting the mixture to methanation at a temperature in a range of 250° C. to 450° C. which is less than the pre-reforming temperature to produce a fuel stream having an increased level of methane relative to the mixture, and supplying the fuel stream and an oxidant to a high temperature fuel cell in which the methane is reformed and electricity is produced by reacting the fuel stream at an anode of the fuel cell and reacting the oxidant at a cathode of the fuel cell.
[0022] In another embodiment the higher carbon hydrocarbon fuel is subjected to partial oxidation over a suitable catalyst to produce a mixture containing hydrogen and carbon monoxide. Typically, the partial oxidation takes place at a temperature of at least 400° C., preferably at least 500° C.
[0023] In yet another embodiment the higher carbon hydrocarbon fuel is processed using an autothermal reformer. The autothermal reformer combines catalytic partial oxidation and steam reforming reactions. The catalytic partial oxidation provides the heat for the endothermic steam reforming reaction. Following autothermal reforming the mixture prior to methanation comprises hydrogen, carbon monoxide and carbon dioxide. Typically, the autothermal reformer is operated at a temperature of at least 400° C., preferably at least 500° C.
[0024] Invariably, the subsequent methanation takes place at a temperature which is lower than that suitable for pre-reforming of the fuel and which is from 250 to 450° C. Management of the temperature regime for the fuel pre-reforming and methanation reactions favours conversion of higher carbon hydrocarbons in the fuel stream and subsequent methane formation.
[0025] By the present invention all of the advantages of the invention described in PCT/AU00/00974 can be achieved, that is a substantially wider source of fuel for the fuel cell than just methane and/or hydrogen, including ethane and liquid higher hydrocarbons such as propane, butane, liquefied petroleum gas (LPG), gasoline (petrol), diesel, kerosene, fuel oil, jet oil, naphtha and mixtures of these, relatively small reactor or reactors for the fuel processing and methanation reactions, and, due to the relatively low operating temperatures, simplified and therefore cheaper equipment for the fuel processing and the methanation. The fuel source may include non-higher hydrocarbons, such as methane, but preferably the higher hydrocarbons form the major component of the fuel source. The preferred fuel is selected from LPG, gasoline (petrol) and diesel.
[0026] In addition, the present invention allows both the reforming of the higher hydrocarbons and the production of methane to be optimised by separating the two steps at temperatures in the respective ranges. For instance, with reference to steam pre-reforming and methanation, the invention involves the following reactions.
[0027] In one aspect, the concept of the present invention concerns lowering the temperature of a pre-reformed gas mixture, as a lower temperature favours methanation of hydrogen and carbon oxides, formed from the processing of the higher hydrocarbons at a higher temperature, and thus increasing methane yield. In the present invention this is done by passing the pre-reformed gas mixture over a reforming/methanation catalyst in a reactor bed/reaction zone which is held at a temperature that is somewhat lower than the pre-reformer temperature. Conceptually, the methanation temperature only needs to be sufficiently lower than the pre-reforming temperature so that a reasonable increase in methane content is achieved. Thermodynamic calculations and experimentation have demonstrated that lowering the temperature by about 50° C. relative to the fuel pre-reforming temperature is capable of giving a significant boost to methane content of the fuel stream to the fuel cell, but smaller or greater temperature differences may be adopted.
[0028] Advantageously, the fuel pre-reforming and methanation may be carried out in a single reactor having a first heating zone for fuel pre-reforming and a second zone for methanation. Interstage cooling may be provided between respective catalyst beds in a single reactor, for example by means of a heat exchanger which may or may not be finned, and the two zones may have independent heating controls. Alternatively, two separate reactors may be provided in series, for example with independent heating controls, with the higher temperature reactor being first.
[0029] The size of the fuel pre-reforming reactor or heating zone will be partly dependent on the selected temperature as lower temperatures usually require lower space velocities and therefore larger volume. The size of the methanation reactor or heating zone will also be partly dependent upon the fuel processing temperature since this will affect the proportion of hydrogen and oxides of carbon relative to methane in the mixture.
[0030] When employed, steam pre-reforming is preferably performed at a temperature no greater than about 550° C., more preferably in the range of 350 to 450° C., and preferably the methanation is performed at a lower temperature in the range 300 to 400° C., more preferably 325 to 350° C. Heat may be supplied during the pre-reforming process, but preferably the pre-reforming and methanation processes are performed adiabatically so that the specified operating temperature is the respective inlet temperature.
[0031] A variety of different steam reformers and methanators have been proposed and any of these may be adopted, bearing in mind the defined operating temperature ranges, and the fact that both reactions may be performed in different zones of same the reactor. The common pre-reformer methanator catalysts are nickel-based, but may comprise, for example, platinum, rhodium, other precious metal, or a mixture of any of these. Steam pre-reforming and methanation are conveniently performed at atmospheric pressure, but higher pressures may be adopted if desired, for example up to 10 kgcm −2 G.
[0032] Commonly, steam reforming of hydrocarbons and methanation of hydrogen and oxides of carbon are carried out at a steam to carbon (S/C) ratio of greater than 2. In the present invention, this however would result in significant dilution of the resultant fuel stream with steam and thus reduction in the fuel value. For example, in the steam pre-reforming, for butane (C 4 H 10 ), eight volume parts of steam must be added to one volume part of fuel for an S/C ratio of 2. For diesel (C 10 ), twenty parts of steam must be added to one part of fuel to achieve an S/C ratio of 2, with the result that there is strong fuel dilution, leading to inefficient electricity production. Preferably therefore, the S/C ratio in the pre-reformer and methanator are below 1.5, more preferably below 1.25 and most preferably below 1.
[0033] Potential carbon deposition problems at the proposed low steam to carbon ratios are alleviated by the mild conditions used in the pre-reformer and methanator. If pre-reforming and methanation are carried out at very low steam to carbon ratios, additional steam may be introduced to the fuel stream entering the fuel cell. Advantageously, the addition of steam may be provided by recycling some of the anode exhaust stream.
[0034] When employed catalytic partial oxidation usually takes place in a first catalytic zone over a catalyst suitable for catalytic oxidation of the higher carbon hydrocarbon fuel. Typically, the catalyst comprises platinum, palladium or rhodium, preferably platinum and palladium, provided on a refractory metal oxide such as alumina, supported on a monolithic body. Useful catalysts supports and autothermal reforming reactors are known in the art and are commercially available. Desirably, the catalyst used to effect catalytic partial oxidation is effective in the presence of sulfur compounds. The temperature of this first catalytic zone is typically 400° C. to 900° C.
[0035] When used, an autothermal reformer uses the same kind of catalyst described for the catalytic partial oxidation. The steam reforming catalyst of the autothermal reformer is typically provided in a second catalyst zone. The catalyst used for the steam reforming reaction may comprise any of the catalytic metals known to be useful for steam reforming, such as nickel, cobalt, platinum and ruthenium and mixtures thereof. The catalyst may be used in the form of a particulate bed or supported on an inert carrier support, as mentioned above for the partial oxidation catalyst. The autothermal reformer is usually operated at a temperature of 300 to 900° C., preferably 400 to 800° C. The pressure is usually from 1 to 10, preferably, from 1 to 5, atmospheres.
[0036] The catalysts for the partial oxidation and steam reforming reactions may be provided in a single reaction zone within the vessel used for autothermal reforming.
[0037] The following equations summarise the catalytic partial oxidation and steam reforming of and higher carbon hydrocarbons (C x H y ) (reactions 1-3):
C x H y +(2 x+y/ 2)O 2 →x CO 2 +y/ 2H 2 O (1) Combustion
C x H y +x/y O 2 →x CO+ y/ 2H 2 (2) Partial oxidation
C x H y +H 2 O→CH 4 +CO+H 2 (3) Steam reforming
CO+H 2 O→H 2 +CO 2 (4)
Reaction (4) is the water-gas shift reaction which is normally at equilibrium.
[0038] Generally, the pre-reforming process will be carried out such that the C 2+ hydrocarbon fuel is resident over the catalyst used in the reforming for a sufficient time to ensure at least substantially complete conversion of the C 2+ hydrocarbons, for example to less than about 0.1% by volume (on a dry basis) in the mixture from the pre-reformer. This alleviates deposition of carbon on the anode of the fuel cell when heavier hydrocarbons are reformed on the anode. However, some C 2+ hydrocarbons may be present in the mixture and in the resultant fuel stream, and preferably there is 97.5% or greater conversion of the C 2+ hydrocarbons in the pre-reforming. More preferably, there is no more than about 0.5 vol % C 2+ hydrocarbons present in the fuel stream to the anode measured on a dry basis. If methane is consumed in the pre-reforming step it is regenerated and the concentration thereof boosted in the subsequent methanation.
[0039] Generally, the methanation process will be carried out such that the hydrogen and oxides of carbon in the pre-reformed mixture are resident over the methanation catalyst for a sufficient time to ensure complete methanation under the prevailing thermodynamic conditions.
[0040] Generally, the methane content of the fuel stream resulting from methanation will be at least 40% by volume, more preferably at least about 50% by volume, even more preferably at least about 60% by volume, and possibly at least about 70% by volume, measured on a dry basis.
[0041] The CH 4 in the fuel stream is internally reformed within the fuel cell in the presence of steam during the oxidation reaction at the anode to produce a waste stream of CO 2 and H 2 O. Steam present in the waste stream may be recycled to the fuel stream input of the fuel cell. The temperature in the fuel cell should be at least 650° C., more preferably at least 700° C. to ensure substantially complete reforming of the methane. In an SOFC the temperature is likely to be at least 700° C. so that complete reforming of the methane is likely to be achieved.
[0042] Preferably, the anode in the fuel cell comprises a nickel material, such as a nickel/zirconia cermet, which is used to catalyse the internal reforming reaction in the fuel cell. The fuel cell and its associated assembly can take any suitable form provided it operates at a temperature of at least 650° C. to provide at least substantial conversion of the methane in the internal reforming reaction. By way of example only, several different planar SOFC components and systems, SOFCs and materials are described in our International Patent Applications PCT/AU96/00140, PCT/AU96/00594, PCT/AU98/00437, PCT/AU98/00719 and PCT/AU98/00956, the contents of which are incorporated herein by reference, including the corresponding U.S. Pat. No. 5,942,349 and patent application Ser. Nos. 09/155,061, 09/445,735, 09/486,501 and 09/554,709, respectively. Other disclosures appear in our International patent applications PCT/AU99/01140, PCT/AU00/00630 and PCT/AU00/00631.
[0043] Generally, the fuel cell to which the fuel stream is supplied will be one of multiple fuel cells to which the fuel stream is also supplied, commonly called a fuel cell stack in the case of planar SOFCs. However, the invention also extends to the process being performed using a single fuel cell.
[0044] Generally, the heavy hydrocarbon fuel will pass through a desulphurising step upstream of the steam pre-reformer in order to alleviate sulphur poisoning the pre-reformer catalyst, the methanator catalyst and/or the anode. Desulphurising of heavy hydrocarbon fuels is well known and will not be described further herein.
[0045] The preferred relatively high levels of methane in the fuel stream to the fuel cell anode have the potential to cause excessive cooling of the fuel cell as a result of the endothermic methane internal steam reforming reaction. This problem is more likely to be encountered in a wholly ceramic SOFC fuel cell stack due to the low thermal conductivity of ceramic materials, but can be alleviated by incorporating metal or metallic components in the fuel cell stack, for example as the gas separators between individual fuel cells, to improve the thermal conductivity across the stack. Alternatively, or in addition, other means may be provided to alleviate excessive cooling at the fuel entry edge of each fuel cell assembly, including preheating of the fuel stream.
[0046] Advantageously, in the process of the invention waste heat from the fuel cell is recycled to the pre-reformer and methanator, which, as noted above, are preferably operated adiabatically. Since the pre-reformer and methanator are only required to operate at relatively low temperatures, any heat exchanger transferring the waste heat to them may be of relatively simple construction and be formed of relatively low-cost materials.
DESCRIPTION OF THE PREFERRED EMBODIMENT
[0047] One embodiment of a process in accordance with the invention will now be illustrated by way of example only with reference to the accompanying drawings which is a block diagram of the process illustrating a typical steam pre-reformer, a typical methanator and an SOFC stack.
[0048] Referring to the drawing, a vessel 10 comprises an upstream steam pre-reformer zone 12 containing a bed of nickel-based catalyst maintained at a temperature in the range 300 to 550° C. and a downstream methanation zone 14 containing a bed of nickel-based catalyst maintained at a lower temperature in the range 250 to 450° C. A heat rejector may be employed at or before the methanation zone 14 to achieve the required cooling. The pre-reformer zone 12 and methanation zone 14 are operated adiabatically, and the zones may take any typical form in which the mixture resulting from the pre-reformer zone 12 can be passed to the lower temperature methanation zone 14 , optionally by way of a heat exchanger 16 .
[0049] Desulphurised heavy hydrocarbon fuel (C 2+ ), such as LPG, is introduced to the vessel 10 at an inlet end 18 and steam is also introduced, at an S/C ratio of no greater than 2.0. The gas flows are such as to provide a sufficient residence time over the catalyst in the pre-reformer zone 12 to achieve at least a 97.5% conversion, and preferably at least substantially 100% conversion, of the heavy hydrocarbons to methane, hydrogen, carbon dioxide and carbon monoxide. At the preferred maximum temperature of 450° C., the resultant fuel mixture should have a minimum methane content, on a wet basis of about 20 vol % and preferably considerably higher at lower S/C values. The steam-containing fuel mixture from the pre-reformer zone 12 passes over the heat exchanger 16 to reduce its temperature and into the methanation zone 14 in which the catalyst is maintained at a lower temperature preferably in the range of 300 to 350° C. The gas flows in the methanation zone are such as to provide substantially complete methanation of the hydrogen and carbon oxides under the prevailing thermodyanmic conditions. At the preferred maximum temperature of 350° C. this may produce a fuel stream from the vessel 10 containing up to about 70% by volume methane on a dry basis.
[0050] The fuel stream, optionally with steam from an anode outlet side 20 of an SOFC stack 22 added to it, is introduced to the anode side of the stack. The fuel cells in the stack 22 operate at a temperature of at least 700° C. and when the fuel stream contacts the nickel/zirconia cermet anodes of the fuel cells the methane in the fuel stream is steam reformed to carbon monoxide and hydrogen.
[0051] At the same time oxygen, in the form of air, is supplied to the cathode side 24 of the fuel cell stack and, when the fuel cell stack is short-circuited through an external load (not shown), the fuel oxidises at the anodes producing electricity and resulting in a CO 2 and H 2 O waste stream at the anode outlet side 20 .
[0052] Waste heat from the SOFC stack 22 is advantageously recycled to the vessel 10 .
EXAMPLES
[0000] Thermodynamic Calculation
[0053] The process of the invention is shown to be feasible by carrying out the thermodynamic calculations, in Examples 1 and 2, and the calculations are compared with corresponding calculations for a process in accordance with PCT/AU00/00974.
Example 1
[0000]
Case 1: A single-stage reformer operated at 400° C.
Case 2: A two-stage reformer with the first stage operated at 450° C. and the second stage at 350° C.
A pure propane feed with a steam-to-carbon ratio of 1.5 is used in these calculations.
[0056] The results are as follows:
Case 1: Methane: 56.45% (v/v) Hydrogen: 24.71 Carbon Dioxide: 18.34 Carbon Monoxide: 0.50 Case 2 Methane: 66.48% (v/v) Hydrogen: 15.52 Carbon Dioxide: 17.86 Carbon Monoxide: 0.14
[0057] It may be seen that the resultant fuel stream methane content is higher in Case 2. In principle the methane content for Case 1 can be increased by operating at the lower temperature of 350° C. However, in practice most commercial catalysts will not have sufficiently high activity for full conversion of higher hydrocarbons at such low temperatures. Similarly, the temperature of the second stage of Case 2 can be lowered to 300° C. for higher methane content. Again, similar practical restrictions apply. From these considerations the above example is a reasonably practical one except for the fact that in practice the reformers (pre-reformer and methanator) will be operated adiabatically rather than isothermally.
Example 2
[0000]
Case 1: A single-stage reformer operated at 380° C.
Case 2: A two-stage reformer with the first stage operated at 380° C. and the second stage at 334° C.
[0060] A pure propane feed with a steam-to-carbon ratio of 1.5 is used in these calculations.
[0061] The results are as follows:
Case 1: Methane: 61.84% (v/v) Hydrogen: 22.45 Carbon Dioxide: 15.43 Carbon Monoxide: 0.28 Case 2: Methane: 71.4% (v/v) Hydrogen: 14.1 Carbon Dioxide: 14.4 Carbon Monoxide: 0.1
Experimental Work
Example 3
[0062] Example 2 was experimented in a dual-bed microreactor. In the first experiment, the first bed was loaded with 1 g of the catalyst C11-PR, a commercial pre-reforming catalyst obtained from United Catalysts Inc. The experiment was performed with the first bed maintained at 380° C. and with no catalyst placed in the second bed. The experiment was therefore a comparative example in accordance with Case 1 of Example 2 and with the process of PCT/AU00/00974. The experiment was performed over a period of 100 hours. Steam-to-Carbon ratio was 1.5 and the space velocity of the reactant was 1250 h −1 . The results are as follows:
TABLE 1 Propane pre-reforming in a single-bed microreactor Hours On Gas Composition Selectivity Stream C 3 H 8 CO 2 H 2 CH 4 CH 4 /H 2 2.2 0 13.6 25.8 60.5 2.35 4.8 0 13.7 25.3 60.8 2.4 7.3 0 13.6 26.2 60.0 2.29 25.3 0 13.9 23.82 61.6 2.59 27.8 0 13.9 24.8 61.2 2.47 30.3 0 13.8 25.3 60.7 2.4 96.8 0 13.8 25.5 60.5 2.37 99.3 0 13.7 26.2 59.9 2.29 101.8 0 13.7 26.3 59.8 2.28 102.8 0 13.7 26.5 59.7 2.25 Average 0 13.7 25.6 60.5 2.37
Example 4
[0063] In the second experiment, the first bed of the dual-bed microreactor was loaded with 0.5 g of the same catalyst and the second bed was loaded with another 0.5 g. The experiment was performed with the first bed maintained at 380° C. and the second bed 334° C. The experiment was therefore in accordance with Case 2 of Example 2 and with the present invention. Again, the experiment was performed over a period of 120 hours and the Steam-to-Carbon ratio and the space velocity of the reactant were the same as in the first experiment. The results are as follows:
TABLE 2 Propane pre-forming in a dual-bed microreactor Hours On Gas Composition Selectivity Stream C 3 H 8 CO 2 H 2 CH 4 CH 4 /H 2 23.2 0 13.2 19.2 67.7 3.53 25.2 0 13.2 19.1 67.6 3.55 27.7 0 13.0 19.6 67.4 3.44 46.2 0 13.3 18.2 68.4 3.75 48.8 0 13.2 18.1 68.7 3.81 51.3 0 13.3 19.3 67.3 3.48 52.3 0 13.2 19.1 67.7 3.55 118.4 0 13.3 19.3 67.3 3.50 119.5 0 13.1 18.6 68.2 3.66 Average 0 13.2 18.9 67.8 3.6
[0064] The results show that the dual-bed reactor increases the methane content in the gas by 12% relative to the single-bed reactor, a distinct advantage for internal reforming solid oxide fuel cell systems. Furthermore, the carbon dioxide contents in Examples 3 and 4 are virtually unchanged within the limits of experimental errors which shows that the fuel is not diluted by any additional CO 2 formation in Example 4. Only the ratio of CH 4 /H 2 is changed favourably towards high methane content in the pre-reformed gas.
[0065] The micro-reactor experiments show the feasibility of the concept. The methane content in the dual-bed reactor achieved in these experiments is lower than that expected from thermodynamics. This shows that in a full-scale reformer there is room for further optimisation of the operating conditions to achieve even higher methane content than that achieved in the microreactor experiments i.e. potentially up to about 71%. In terms of the methane content, the efficiency of the microreactor was 95%.
[0066] Unless otherwise specified, any reference herein to a volume percentage content of the fuel mixture or fuel stream is given on a dry basis that is without accounting for the steam present in the fuel mixture or fuel stream.
[0067] Those skilled in the art will appreciate that the invention described herein is susceptible to variations and modifications other than those specifically described. It is to be understood that the invention includes all such variations and modifications which fall within its spirit and scope. The invention also includes all of the steps and features referred to or indicated in this specification, individually or collectively, and any and all combinations of any two or more of said steps and features.
[0068] The reference to any prior art in this specification is not, and should not be taken as, an acknowledgment or any form of suggestion that that prior art forms part of the common general knowledge in Australia or elsewhere.
[0069] Throughout this specification, unless the context requires otherwise, the word “comprise”, and variations such as “comprises” and “comprising”, will be understood to imply the inclusion of a stated integer or step or group of integers or steps but not the exclusion of any other integer or step or group of integers or steps. | A process for producing electricity in a fuel cell which comprises: a) pre-reforming a higher carbon (C2+) hydro-carbon fuel in a pre-reformer under conditions effective to achieve substantially complete conversion of higher carbon (C2+) hydro-carbons to produce a pre-reformed fuel stream; b) subjecting the pre-reformed fuel stream to methanation under conditions effective to produce a fuel stream having an increased concentration of methane relative to the pre-reformed fuel stream; and c) supplying the fuel stream and an oxidant to a high temperature fuel cell in which methane is reformed and electricity is produced by reacting the fuel stream at an anode of the fuel cell and reacting the oxidant at a cathode of the fuel cell. | 7 |
BACKGROUND OF THE INVENTION
The present invention relates to a brake adjustment mechanism for adjusting a vehicle brake for wear, and more particularly to an automatic brakeshoe adjustor assembly to accommodate wear of brake linings on cam actuated air brakes of the type commonly employed on large heavy duty vehicles, such as trucks and truck trailers.
The air brakes that are used on heavy duty vehicles generally include an air brake chamber to which air is supplied when the vehicle is subjected to braking. When pressurized air is admitted to the brake chamber, a braking force is transmitted to a cam shaft via the action of a push rod and brake lever. Once the cam shaft is rotated, the cam at the end thereof, commonly an S-cam, simultaneously rotates against a roller engaged at both ends of the brakeshoe webs. This actuation on the respective rollers causes the brakeshoes to be spread apart forcing the brakeshoe lining against the brake drum, thereby causing the wheels of the vehicle to stop.
The brakeshoes generally employed on these types of vehicles can be of two types: a double web and/or a single web brakeshoe. The double web brakeshoe is used for brakes having a greater surface area which generally require a wider shoe and brake lining, and therefore necessitate a greater support in the form of a double web. This form of the brakeshoe is utilized on wheels of trailers and truck vehicles whose loads are substantial. The roller assemblies engaged at the ends of these webs for actuation by the cam shaft are generally made up of a hollow roller embodying a concentric pin axially extending from the roller along the roller's rotational axis, such as those set forth on pages 1-2 to 1-14, 1-18 to 1-30, and 1-52 to 1-54 of the Euclid Brake Parts Manual. The rollers are disposed between the ends of the double webs by having the pins engaged in semi-circular or circular openings positioned at the ends of the webs as illustrated in the parts drawings of the Euclid Brake Parts Manual.
The single web brakeshoe supports a lesser braking surface area for the brake lining and is generally used on the front of the truck where substantial weight loads are not a factor. Accordingly, these brakeshoes use a single web for supporting the shoe and corresponding brake lining. The type of roller assembly employed for actuation by the cam shaft usually consists of a pair of rollers on either side of an end portion of the single web and connected to each other by a pin concentrically fixed to each of the rollers. The exposed portion of the pin between the rollers is engaged in a semi-circular or circular opening in the end portion of the web, as illustrated on pages 1-2 and 1-16 of the Euclid Brake Parts Manual.
The foregoing braking systems used on heavy duty vehicles typically include some form of mechanism that will compensate for and progressively take up the slack that is generated by wear of the brake linings. An adjustment is needed because the clearance that normally exists between the brake drum and brakeshoe lining will eventually increase beyond a preset limit due to the wear of the brakeshoe lining. When these brakeshoe linings wear, the push rod of the air brake chamber has to be extended or pushed further to rotate the cam shaft against the brakeshoes to compensate for the increased clearance. The Department of Transportation imposes strict requirements for the clearance limits depending on the size and configuration of the braking system employed.
Common forms of brake adjustors generally employed include slack adjustors, which are usually positioned between the push rod and the cam shaft. Other forms include self adjusting brake adjustors that operate more directly at or near the brakeshoe(s) to compensate for wear. The present invention falls within this latter class of brake adjustors, and typical disclosures may be found in U.S. Pat. Nos. 1,875,064 and 1,875,065, both issued to Lyman (1932); U.S. Pat. No. 2,522,903 issued to Shively (1950); and U.S. Pat. No. 4,586,589 issued to Idesawa (1986). Unfortunately, the mechanisms disclosed therein contain a multitudinous number of parts, require extensive assembly and disassembly when the brakes are subjected to routine maintenance, and require extensive and frequent maintenance themselves by the replacement of worn, misaligned or failed parts which can lead to a costly and time consuming practice. These factors render the foregoing devices impractical for extensive and reliable use.
What is needed then is a self adjusting brakeshoe adjustor that consists of a minimum number of parts, is relatively inexpensive to manufacture, and which is dependable and reliable in its construction. It is also desirable that such a device be easily incorporated into existing braking configurations, installed or removed without disassembly, one that requires minimal maintenance, and optimally, one which can operate with or without the existence of an automatic slack adjustor.
The foregoing desirable characteristics of a self adjusting brake adjustor are accomplished by the invention herein which is described below.
SUMMARY OF THE INVENTION
The present invention provides a brakeshoe adjustor that is self adjusting and actuated by a cam shaft usually found in a vehicle air braking system. The brakeshoe adjustor according to the invention is preferably utilized in heavy duty air braking vehicles that employ single and/or multiple-web brakeshoes, the latter usually being double web brakeshoes. In both arrangements, the adjustor is deployed intermediate to the end of each brakeshoe web and a cam of a cam shaft for simultaneous actuation by the cam shaft.
For the double web brakeshoe, the brakeshoe adjustor includes a roller assembly, a cylindrical roller sleeve, and a pawl assembly. The roller assembly comprises a fixed eccentric roller and spindle arrangement for engagement with the cylindrical roller sleeve. The eccentric roller fixedly embodies a spindle eccentrically extended on both ends thereof for engagement with the end portions of each web of the brakeshoe. At least one portion of the spindle is provided with ratchet means for constant engagement with a mateable pawl. The ratchet means can be in the form of ratchet teeth disposed on the surface of the spindle extension or an annular ratchet wheel having ratchet teeth disposed about the wheel and concentrically mounted and secured to the spindle for engagement with the mateable pawl.
As noted above, a cylindrical roller sleeve is provided which is slidably mounted onto the eccentric roller. Means are also provided for limiting the rotation of the sleeve about the eccentric roller by a predetermined amount when the sleeve is actuated by the cam shaft. The roller sleeve preferably include at least one arcuate slot within one or both ends thereof for receiving a corresponding number of pins extending from one or both proximate ends of the eccentric roller to permit a corresponding arcuate rotation of the roller sleeve about the roller when the sleeve is actuated by the cam of a cam shaft, preferably an S-cam. The rotation of the roller sleeve about the eccentric roller is therefore limited by the protrusion of the pin extending from the roller into the arcuate slot of the roller sleeve. Multiple arcuate slots in each circumferential end of the roller sleeve, along with a corresponding number of pins extending from the eccentric roller, can also be provided to ensure the secure limited rotation of the roller sleeve about the eccentric roller, and also for fixedly securing the spindle within the roller if the spindle and roller are manufactured from separate components.
The brakeshoe adjustor further comprises a pawl assembly which in one embodiment may include (i) at least one bracket sleeve for slidable engagement with a corresponding web end of the brakeshoe and having an opening for slidably receiving one extension of the spindle therethrough; and (ii) at least one pawl secured to the side of the bracket sleeve for engagement with the ratchet means about the spindle extension to permit rotation of the spindle in one direction only, which will generally be to restrain the combined spindle and eccentric roller from turning in the direction of actuation of the cam shaft.
Another embodiment for the pawl assembly includes more than one bracket sleeve with the multi-webbed or double-webbed brakeshoe, one for mounting onto each web end to engage both the respective extensions of the spindle from the eccentric roller. Ratchet means are then provided about both spindle extensions, such as ratchet teeth about the ends thereof or annular ratchet wheels concentrically mounted onto the spindle extensions, for engagement with the respective pawl(s) secured to the side of each bracket sleeve.
As an alternative to the bracket sleeve, the pawl assembly can include a pawl mounted directly to the side of the web end of the brakeshoe for respective engagement with the ratchet means about the spindle extension(s). Constant engagement of the pawl with the ratchet means is required and is maintained by the constant engagement of the cam with the roller sleeve, which in turn holds the spindle extensions to the web ends of the brakeshoe by appropriately shaped openings about the web ends for receiving the spindle extensions therein. Constant engagement of the pawl with the ratchet means may also be obtained by the use of a spring clip disposed about the spindle extensions and secured to the web end. At least one pawl can be positioned on the side of both webs for engagement with the respective ratchet means provided about both spindle extensions.
The bracket sleeve is used to permit incorporation of the brakeshoe adjustor herein onto existing double webbed brakeshoes without any modification to the brakeshoe web, e.g., in the situation where a pawl or plurality of pawls are mounted directly to the web itself. As already noted, constant engagement of the pawl with one of the ratchet teeth of the ratchet means is required for the successful operation of the brakeshoe adjustor according to the invention herein.
For the single web brakeshoe configuration, the brakeshoe adjustor comprises a roller assembly, a cylindrical roller sleeve, and a pawl assembly. The roller assembly comprises a pair of eccentric rollers axially separated by and fixedly secured to a spindle for engagement of the spindle with the end portion of the brakeshoe web at a point between the eccentric rollers. The spindle is provided with ratchet means disposed about at least one portion thereof, and may be positioned about a point between the eccentric rollers or about one or both ends of the spindle if the spindle is extended beyond the eccentric rollers, for engagement with a corresponding number of pawls to restrain the rollers and spindle from turning in the direction of actuation of the cam shaft.
A pair of cylindrical roller sleeves are provided for slidably receiving each of the corresponding eccentric rollers therein. Means are also provided for limiting the rotation of the sleeve about the eccentric roller by a predetermined amount when one or both sleeves is actuated by the cam shaft. This is preferably accomplished by providing at least one arcuate slot about an end of at least one of the sleeves, preferably both, to receive a corresponding number of pins extending from a proximate end of the respective eccentric roller to permit corresponding arcuate rotation of the sleeve about its respective roller when one or both roller sleeves are tangentially engaged and actuated by the cam of the cam shaft. While it is desirable to have both roller sleeves provided with at least one arcuate slot about one or both ends thereof, only one roller sleeve need have the arcuate slot and pin combination about an end thereof for the operation of the brakeshoe adjustor according to the invention herein. In this case, the roller sleeve that is without the slot can be held into place on its respective eccentric roller by any conventional means known in the art, for example, by the employment of a cotter pin, snap ring, etc.
In one embodiment for the single web brakeshoe, the pawl assembly comprises (i) a bracket sleeve for slidable engagement with the end portion of the single web and having at least one opening for slidably receiving the spindle therethrough and beyond at least one of the eccentric rollers; and ii) at least one pawl secured to one or both sides of the bracket sleeve for engagement with a ratchet means disposed about the spindle portion extended beyond one or both rollers, as in the double web configuration, to permit rotation of the roller sleeves about their respective eccentric rollers in one direction only, which will generally be to restrain the spindle and eccentric rollers, which are in fixed engagement with respect to each other, from turning in the direction of actuation of the cam shaft. The ratchet means may be in the form of ratchet teeth provided about one or both spindle extensions, or annular ratchet wheels fixedly mounted onto the spindle extension(s), for engagement with the respective pawl(s) secured to one or both sides of the bracket sleeve.
As an alternative to the bracket sleeve, the pawl assembly can include at least one pawl mounted directly to one or both sides of the web end of the brakeshoe for respective engagement with the ratchet means disposed about one or both of the spindle extensions. Constant engagement of the pawl with the ratchet means of the spindle may be maintained by the constant engagement of the cam with the roller sleeve, which in turn holds the spindle to the web end of the brakeshoe at a point between the eccentric rollers, or by the use of a spring clip disposed about the spindle and secured to the web end.
In order to avoid extending the spindle beyond either or both eccentric rollers of the roller assembly, the foregoing annular ratchet wheels of the ratchet means may be employed interior of the eccentric rollers for engagement with the respective pawl(s) secured to one or both sides of the single web or bracket sleeve, as the case may be.
Inasmuch as there are two brakeshoes employed for each brake assembly on a given wheel, two brakeshoe adjustors according to the invention will be employed in the brake assembly, one at the end portion of each brakeshoe for simultaneous actuation by the cam shaft.
In operation, the push rod of the braking system is depressed which causes the brake lever to rotate the cam shaft. The cam in turn simultaneously actuates both of the roller sleeves at each end of the brakeshoe web, which in turn forces the brakeshoes and their respective linings outward into contact with the brake drum. The arcuate slot in the roller sleeve accommodates the permissible critical distance that the sleeve must travel for the brakeshoe lining to make contact with the brake drum when the brakes are applied.
As the lining of the brakeshoes wear, the roller sleeves will have to rotate a greater arcuate distance about the eccentric roller. Eventually, the sleeve will become engaged with the pin extending from the eccentric roller to cause a rotation of the rollers about their respective spindles. Once the spindles are rotated, the pawl will encounter the next ratchet tooth of the ratchet means and restrain the spindle and eccentric roller from moving in the direction of actuation of the cam shaft. In this manner, the distance that the push rod must be depressed will always stay within the limits of brake specifications as reflected by the arcuate length of the slot within the roller sleeve. Thus, the brakes will maintain their adjustment and be self adjusting to accommodate wear of the brakeshoe linings.
BRIEF DESCRIPTION OF THE DRAWINGS
A complete understanding of the present invention may be obtained by reference to the accompanying drawings, when taken in conjunction with the detailed description thereof and in which:
FIG. 1 is an exploded isometric perspective view of a self adjusting brakeshoe adjustor according to the invention for use with a conventional double webbed brakeshoe of a cam operated air brake for a heavy duty vehicle.
FIG. 1A is an exploded isometric perspective view of an alternative embodiment of the brakeshoe adjustor shown in FIG. 1.
FIG. 2 is an isometric perspective view of assembled cam operated, double webbed air brakeshoes of a heavy duty vehicle incorporating the brakeshoe adjustor shown in FIG. 1.
FIG. 3 is a detailed front elevational plan view of the left portion of the upper brakeshoe illustrated in FIG. 2.
FIG. 4 is a front elevational plan view of the right portion of the upper brakeshoe illustrated in FIG. 2, additionally showing an alternative embodiment of the brakeshoe adjustor according to the invention herein.
FIG. 4A is an alternative embodiment of the brakeshoe adjustor used for the upper brakeshoe illustrated in FIG. 2 according to the invention herein.
FIG. 5 is a front elevational plan view of a self adjusting brakeshoe adjustor according to the invention which is adapted for use with a single web brakeshoe of a cam operated air brake for a heavy duty vehicle.
FIG. 6 is an exploded isometric perspective view of a pair of single web brakeshoes incorporating an alternative embodiment of the brakeshoe adjustor according to the invention without the use of the bracket sleeve 24 shown in FIG. 5.
FIG. 7 is a front elevational plan view of an alternative embodiment of the brakeshoe adjustor assembly shown in FIG. 5.
FIG. 8 is an exploded isometric perspective view of the brakeshoe adjustor shown in FIG. 1 incorporating an alternative embodiment of the pawl assembly.
FIG. 9 is a front elevational plan view of the left portion of the upper brakeshoe illustrated in FIG. 2 incorporating the alternative pawl assembly embodiment shown in FIG. 8.
FIG. 10 is a front elevational plan view of the right portion of the upper brakeshoe illustrated in FIG. 2 incorporating an alternative embodiment of the pawl assembly shown in FIG. 9.
FIG. 11 is a front elevational plan view of the brakeshoe adjustor and pawl assembly shown in FIG. 9 adapted for use with the single web brakeshoe illustrated in FIG. 6.
FIG. 12 is a front elevational plan view of the brakeshoe adjustor shown in FIG. 11 incorporating a bracket arrangement for the pawl assembly also shown in FIG. 11.
DESCRIPTION OF THE PREFERRED EMBODIMENTS
The following is a description of a preferred embodiment of the self adjusting brakeshoe adjustor according to the invention herein for use with a cam operated double web brakeshoe that is typically employed in the trailer and/or truck portion of a heavy duty vehicle.
Referring to FIG. 1, a self adjusting brakeshoe adjustor 2 is shown in an exploded perspective view wherein a roller assembly is provided comprising a cylindrical eccentric roller 10 mounted onto a spindle 12 extended on both ends of the eccentric roller. A hollow cylindrical roller sleeve 16 is also provided to slidably receive eccentric roller 10 therein for rotational engagement therewith. Roller sleeve 16 contains a slot 18 at one proximate end for engagement with a pin 20 inserted into (with a press fit, or by any other conventional means known in the art) and extending from the roller 10 to limit rotational movement of the roller sleeve 16 relative to the roller 10 by the length of the arcuate slot 18.
As shown in FIG. 1A, an additional pin 21 may optionally be inserted into eccentric roller 10, which is circumferentially equidistant from pin 20, for engagement with a corresponding slot 18A provided about the edge of sleeve 16. Any number of pins and corresponding sleeve slots may be employed to insure engagement of roller 10 with sleeve 16.
Spindle 12 and eccentric roller 10 may be fabricated as a one piece construction, or as two separate units in which case the spindle 12 can be inserted into an off center opening of roller 10, and then fixed within roller 10 by means of pin 20 inserted through spindle 12 and into the roller. In the latter case, pin 20 will serve the dual function of maintaining spindle 12 and roller 10 in fixed engagement with respect to each other and limiting the rotational movement of roller 10 within the roller sleeve 16 by the arcuate distance of slot 18. In either case, care should be taken not to have pin 20 extend beyond the outside diameter of roller sleeve 16 to avoid impingement with the surface of S-cam 30 (illustrated in FIG. 2).
One portion of the spindle 12 is provided with a plurality of ratchet teeth 14 about its surface for continuous engagement with a mateable pawl 26 mounted to the side of a bracket 24. This is accomplished by the circular opening in bracket 24 adapted in size to slidably receive the ratcheted portion of spindle 12 therethrough. As illustrated in FIGS. 2, 3 and 9, bracket 24 is also sized and configured to slidably mount onto the web ends 41 and 43 of double web brakeshoes 39,40 for accommodating the disposition of the self adjusting brakeshoe adjustor between webs 43,44 and 41,42 for engagement with S-cam 30. It is to be noted that double web brakeshoe 40 can accommodate a bracket 24 on each web end as illustrated in FIG. 4A. In this case a plurality of ratchet teeth 14 is provided to both ends of spindle 12 for engagement with pawl 26 secured to each bracket 24 which in turn is slidably mounted to the end of webs 43 and 44. As an optional embodiment, an additional pawl 26A may be mounted to bracket 24 as shown in FIG. 3, to insure engagement with ratchet teeth 14. Securement of both ends of spindle 12 to the web of the brakeshoe by means of bracket 24 is important to insure and maintain continuous engagement of the pawl 26 with any one of ratchet teeth 14 on spindle 12 (FIGS. 2 and 3).
FIG. 2 illustrates the assembly of conventional double web brakeshoes 39 and 40 in a heavy duty vehicle incorporating the self adjusting brakeshoe adjustors shown in FIG. 1. Double web brakeshoes 39 and 40 are operatively joined to each other at one end in a hinged arrangement by means of pins 54 and 56 inserted through brake spider 50 for engagement with webs 41,42 and 43,44 which engage the self adjusting brakeshoe adjustors at the opposite ends. Brakeshoe spring 58 insures continuous return of the brakeshoes to their original position after engagement with the brake drum.
As shown in FIG. 2, two self adjusting brakeshoe adjustors, one for each end of the double web of each brakeshoe 39 and 40, are required to make up the entire double web brake assembly. The roller sleeves 16 of each self adjusting brakeshoe adjustor for brakeshoes 39 and 40 are brought to bear on S-cam 30 by means of brakeshoe spring 58 which insures continuous engagement of the S-cam with the roller sleeves. Upon actuation of the brake pedal by the driver of the heavy duty vehicle, rotational movement of S-cam 30 by cam shaft 32 exerts a force on the respective roller sleeves 16 to cause brakeshoes 39 and 40 to expand outwardly into contact with the brake drums (not shown), which in turn causes a braking of the vehicle.
FIG. 4 shows an alternative embodiment for the engagement of pawl 26 with ratchet teeth 14 of spindle 12, which differs from the arrangement shown in FIG. 3 in that pawl 26 is fixed directly to the side of web 44 (as opposed to pawl 26 being fixed to bracket 24 in FIG. 3). As an optional embodiment, pawl 26B may be mounted to the lower or end portion of web 44 as an added insurance for engagement with ratchet teeth 14. The self adjusting brakeshoe adjustor is held into place between and at the lower end of webs 43 and 44 by the engagement of roller sleeve 16 with the S-cam 30. The advantage of this configuration is that the need for bracket 24 as an extra component of the self adjusting brakeshoe adjustor is obviated. The advantage of the configuration shown in FIG. 3 utilizing bracket 24 is that the self adjusting brakeshoe adjustor can be easily incorporated into existing brake assemblies without the need for redesigning the brakeshoe webs for incorporation of pawl 26. Bracket 24 also provides additional support for securing spindle 12 into place between webs 43 and 44.
In accordance with another aspect of the invention, the bracketed configuration for brakeshoe web 43 illustrated in FIG. 3 can be duplicated for brakeshoe web 44 of FIG. 4. That is, an additional bracket, having a mirror image of bracket 24, with a corresponding pawl identical to pawl 26, can be made a part of the self adjusting brakeshoe adjustor for engaging ratchet teeth 14 and for securing spindle 12 to web 44. The additional bracket and pawl assembly, which mounts onto web 44 in the same manner as bracket 24 mounts onto web 43, will provide added insurance for the proper functioning of the self adjusting brakeshoe adjustor.
An alternative arrangement for the pawl assembly is illustrated in FIG. 8 wherein an annular ratchet wheel 82 is provided for slidable engagement with spindle 12, the ratchet wheel being provided with a plurality of ratchet teeth 84 radially extending from substantially the wheel's inner circumference to its outer circumference on the side of the wheel facing the pawl. A key member 86, extending inwardly from the inner circumference of the annular wheel 82, is provided for engaging a corresponding key slot 19 incorporated into the surface of spindle 12 such that when ratchet wheel 82 is slidably mounted onto spindle 12, the ratchet wheel is rotatably fixed in place and prevented from rotating about spindle 12. As will be seen in FIG. 9, one of the ratchet teeth 84 will engage pawl 27 mounted to bracket 24 when the ratchet wheel is concentrically mounted onto spindle 12 and moved up against bracket 24. In order to maintain constant engagement of the ratchet wheel with pawl 27, a coil spring 88 is slidably mounted onto spindle 12, followed by a circular locking ring 89, for urging the ratchet wheel 82 against bracket 24. A slot 13 is provided about the circumferential surface of spindle 12 (see FIG. 8) for fixedly securing the locking ring 89 in place. Additional pawls, such as that shown by reference numeral 27A, may be added to bracket 24 to insure proper alignment of the ratchet wheel with pawls 27 and 27A. Any number of pawls may be added about bracket 24 (or about web end 44 in FIG. 10).
The pawl assembly utilizing the annular ratchet wheel configuration (as illustrated in FIGS. 8, 9 and 10) offers an economical advantage in that the pawl assembly takes up less space. It also permits the ratchet means to be utilized between web 43 (and/or 44) and roller sleeve 16, as is illustrated by ratchet wheel 82A engaged with pawl 27B and held in place by disc spring 94.
The foregoing alternative arrangement for the pawl assembly can be modified as shown in FIG. 10 wherein the above-identified pawl(s) can be attached directly to each side of web 44 itself, thereby eliminating the need for the bracket configuration shown in FIG. 9. One configuration does not preclude the use of the other, and any of the pawl assemblies can be used in combination with each other, such as, for example, a combination of the arrangements shown in FIGS. 9 and 10.
Next follows a description of a preferred embodiment of the self adjusting brakeshoe adjustor when used with a cam operated single web brakeshoe which is typically employed in the front axle portion of a heavy duty vehicle.
Referring to FIG. 6, a single web brakeshoe assembly is illustrated showing the incorporation of a pair of corresponding self adjusting brakeshoe adjustors according to the invention herein. As shown in greater detail in FIG. 5, a spindle 12 is provided having a pair of eccentric rollers 72 and 73 eccentrically and fixedly engaged therewith in a spaced apart relationship. Spindle 12 extends through and beyond roller 73, whereas the opposite end is inserted in and fixed within roller 72. A corresponding pair of hollow cylindrical roller sleeves 70 and 71 are provided and adapted to receive rollers 72 and 73, respectively, therein, for rotational engagement with their counterparts. As illustrated in FIG. 5, roller sleeve 71 contains a slot 71' at its outer edge for engagement with pin 20 fixedly secured in and extending from roller 73 to limit rotational movement of roller sleeve 71 relative to roller 73 by the length of the arcuate slot 71'. In similar fashion, roller sleeve 70 on the opposite side of web 66, contains a slot 70' at its outer edge for engagement with pin 20A secured in and extending from roller 72 to limit rotational movement of roller sleeve 70 relative to roller 72 by the length of the arcuate slot 70'. Pins 20A and 20 are press fitted into rollers 72 and 73, respectively, after roller sleeves 70 and 71 are mounted onto to their counterpart rollers. Arcuate slots 70' and 71' are equidistant to provide synchronous rotational movement of both roller sleeves about respective eccentric
Spindle 12 and rollers 72 and 73 may be fabricated as a one piece construction, or as three separate units in which case the spindle 12 can be inserted through an off center (eccentric) opening of roller 73, and into an identical opening within (but not all the way through) roller 72. Spindle 12 is fixed within roller 72 by any conventional means (such as by a spline or key arrangement) and within roller 73 by means of extended pin 20 which can be press-fit through roller 73 and into spindle 12 after the respective sleeves are mounted onto spindle 12. With this latter arrangement, pin 20 will serve the dual function of (i) maintaining spindle 12 and roller 73 in fixed engagement with respect to each other, and (ii) limiting the rotational movement of roller 73 within the roller sleeve 71 by the arcuate distance of slot 20. Pin 20A will likewise serve to restrict the rotational movement of roller sleeve 70 about roller 72 by the arcuate distance of slot 70'.
The portion of spindle 12 extending beyond the roller assembly of rollers 70 and 71 is provided with a plurality of ratchet teeth 76 about its surface for continuous engagement with a mateable pawl 68 mounted to the side of a bracket identical to the bracket 24 shown in FIGS. 1 and 3. As in FIGS. 1 and 3, this is accomplished by the circular opening in bracket 24 which is sized to slidably receive the ratcheted portion of spindle 12 therethrough. Bracket 24 is then slidably mounted onto single web 66 of brakeshoe 60, which includes brakeshoe lining 64 and brakeshoe lining support plate 62, for positioning the brakeshoe adjustor onto the end of web 66 for engagement with S-cam 30. Securement of spindle 12 to the web of the brakeshoe by means of bracket 24 insures the continuous engagement of pawl 68 with any one of ratchet teeth 76 on the extended end of spindle 12, although when assembly of the brakeshoe is complete, the action of S-cam 30 on rollers 70 and 71 will serve to keep the adjustor assembly in place in the half moon opening 79 on the end of web 66.
FIG. 7 shows an alternative embodiment for bracket 24 and the brakeshoe adjustor assembly of FIG. 5 whereby pawls 68 and 69 are positioned on both sides of bracket 80 for corresponding engagement with ratchet teeth 76 and 77, respectively, provided on both ends of spindle 12. In this configuration, spindle 12 is extended through and beyond each roller 72 and 73 and fixedly secured therein either by conventional means or by pins 20 and 20A in the same manner as described for the configuration illustrated in FIG. 5. Bracket extensions 80A and 80B are provided with appropriate openings for the insertion of spindle 12 therethrough. The arrangement of the remainder of brakeshoe adjustor components, roller sleeves 70 and 71, rollers 72 and 73, pins 20 and 20A, and arcuate slots 70' and 71', are the same as shown in FIG. 5.
FIG. 6 shows the self adjusting brakeshoe adjustors engaged with pawls 68 and 68A which are mounted directly to the side of single webs 66 and 67, respectively. The advantage of this configuration is that the need for a bracket, such as those illustrated in FIGS. 4 and 6, is obviated. As with the brakeshoe adjustor used in the double web configurations of FIGS. 1-3, the use of a bracket allows the brakeshoe adjustor to be easily incorporated into existing brake assemblies without the need for redesigning the brakeshoe web for direct attachment of pawls 66 and 67. The bracket arrangement also provides additional support for securing spindle 12 into place at the end 79 of single webs 66 and 67.
Securement of the assembled self adjusting brakeshoe adjustor onto the end of web 79 (FIG. 6) is accomplished by the engagement of the roller sleeves 70,71 with S-cam 30 or by means of a wire clip (not shown) attached to bracket 24 and web 66 or 67, as the case may be. In the event no bracket is used, as with the configuration shown in FIG. 6, a spring clip (not shown) may be mounted onto the brakeshoe adjustor for engagement with the end of web 79.
As shown in FIGS. 11 and 12, the ratchet wheel 82 of the ratchet means can also be used in conjunction with the brakeshoe adjustor for a single web brakeshoe. FIG. 11 illustrates a pawl 92 secured directly to the side of single web 66 for engaging ratchet wheel 82. The ratchet wheel is held engaged with pawl 92 by means of a circular disc spring 94 mounted onto spindle 12 such that the presence of the roller and roller sleeve combination will provide the requisite support for urging disc spring 94 against annular ratchet wheel 82 to secure such engagement.
The configuration illustrated in FIG. 12 is identical to that shown in FIG. 11 with the exception that a U-shaped bracket 90 having pawl 92 secured to the side thereof is mounted onto single web 66. Bracket 90 is provided with the appropriate openings for having spindle 12 inserted therethrough. The ratchet wheel 82 is held engaged with pawl 92 in similar fashion by means of disc spring 94 mounted onto spindle 12 between bracket 90 and the roller and roller sleeve combination, 73 and 71.
To insure proper functioning of the brakeshoe adjustor during operation, an annular ratchet wheel and pawl assembly, identical to a mirror image of that set forth in FIGS. 11 and 12, may be added on the other side of the single web (not shown), i.e., between the roller and roller sleeve combination, 73 and 71, and single web 66.
The material used for the various components of the self adjusting brakeshoe adjustor is a metal whose structural integrity is capable of withstanding the force exerted by operation of the S-cam against the roller sleeve(s), and which will withstand the corrosive effects normally encountered during vehicle operation. The preferred metal is stainless steel, although other metals of a similar nature can be utilized.
The operation of any of the illustrated self-adjusting brakeshoe adjustors according to the invention herein, is achieved by the normal functioning of the cam-operated brakes typically employed on heavy duty vehicles. As already noted hereinbefore, and as shown in FIG. 2, a pair of brakeshoe adjustors is required for the proper functioning of the brakeshoes 39 and 40. Thus, when the vehicle's brake pedal is depressed by its operator, air under pressure is caused to be supplied to the air brake chamber (not shown), thereby transmitting a braking force to cam shaft 32 via the action of a push rod and brake lever (also not shown).
By additionally referring to FIGS. 3 and 4, once cam shaft 32 (shown in FIG. 2) is rotated, the S-cam 30 at the end thereof simultaneously rotates against roller sleeves 16 of each brakeshoe adjustor engaged at the end of each brakeshoe webs 41, 42 and 43,44. The outside surface of the roller sleeves for both arrangements of the single and double web brakeshoe adjustors are preferably knurled as indicated by the numeral 17 in FIGS. 1, 1A, 8 and 11. The actuation of S-cam 32 against roller sleeve 16 of each brakeshoe adjustor, causes roller sleeve 16 to rotate about roller 10, and operates to expand brakeshoes 39 and 40 for making contact of the brake linings 46 and 48, supported by brakeshoe lining support plates 45 and 47, respectively, with the brake drum (not shown), thereby causing the rotating wheels of the vehicle to come to a halt. The arcuate distance that roller sleeve 16 must travel, or the distance that the brakeshoes 39 and 40 must expand outward about pins 54 and 56, represents the distance or "play" that the push rod must travel before brakeshoes 39 and 40 engage the brake drum. Once contact is made between the brake linings and brake drum, the rotation of S-cam 30 and roller sleeve 16 (and roller sleeves 70 and 71 in the case of the single web arrangement) will cease.
The distance that brakeshoes 39 and 40 must expand outward about pins 54 and 56 will gradually increase due to the wear of the brake linings 46 and 48 coming into repeated contact with the brake drum. This will cause roller sleeves 16 and 70 and 71 to rotate further in order to make the necessary contact of the brake lining of the brakeshoe with the brake drum. Eventually, roller sleeve 16 (and 70 and 71) will make contact with corresponding pins 20 and 20', thereby actuating the eccentric roller and spindle arrangement. Once eccentric roller 10 (and 72 and 73), and thus spindle 12, is rotated, the brakeshoe lining will expand outwardly until the brake lining makes contact with the brake drum. After the brake is released by the vehicle operator, the distance between the brake lining and brake drum will be maintained by the engagement of pawl 26 with ratchet 14 at the end of spindle 12 to prevent spindle 12 from rotating back to its original position before being advanced by its corresponding roller sleeve. Thus, each engagement with the next ratchet tooth by pawl 26 will reflect a corresponding amount of wear experienced by the respective brake lining.
Stated another way, the arcuate distance of slot 18 (FIGS. 3, 4, 9 and 10) and slots 70' and 71' (FIGS. 5, 7, 11 and 12) represents the maximum distance that S-cam 30, and roller sleeve 16 and roller sleeves 70 and 71, can travel before engaging pins 20 and 20' to advance the eccentric rotation of spindle 12 for maintaining the proper clearance of the brake lining with the brake drum. Automatic adjustment of the brakeshoe is thereby achieved in an efficient and economical manner with a minimum of moving parts.
It will be readily seen that the ratchet and pawl assemblies represented in FIGS. 8 through 12 are another way of maintaining the rotational advance of spindle 12 for maintaining the proper clearance between the brake lining and brake drum.
In order to maintain a proper or predetermined distance between the brake linings and brake drum (when the brakes are not applied), the eccentric distance between the axis of spindle 12 and the axis of roller 10 (and rollers 72 and 73 in the single web configurations) will represent the maximum distance that the brakeshoes can be outwardly expanded for adjustment before making contact with the brake drum. This distance must be at least as great as the thickness of the brake lining in order that the distance between the brake lining and the brake drum will always be maintained. Thus, the diameter of roller 10 (double web) and rollers 72 and 73 (single web) in relation to the eccentric positioning of spindle 12 will vary depending on the diameter size of brakeshoes 39 and 40 and corresponding brake linings 48 and 46.
Since other modifications and changes varied to fit particular operating requirements and environments will be apparent to those skilled in the art, the invention is not considered limited to the example chosen for purposes of disclosure, and covers all changes and modifications which do not constitute departures from the true spirit and scope of this invention. | The present invention relates to a cam-operated, self-adjusting brakeshoe adjustor that is utilized in heavy duty air braking vehicles that employ single and/or multiple-web brakeshoes. The brakeshoe adjustor includes a roller assembly, a cylindrical roller sleeve, and a pawl assembly. The roller assembly comprises a fixed eccentric roller(s) and spindle arrangement for slidable engagement with a cylindrical roller sleeve(s) which in turn is actuated by the rotation of the cam shaft. At least one portion of the spindle is provided with a ratchet for constant engagement with a mateable pawl. The rotation of the roller sleeve(s) about the eccentric roller(s) is limited by the arcuate distance of a slot contained about the edge of the roller sleeve within which a pin, radially extending from the roller, is engaged. In one embodiment, the pawl assembly comprises (i) at least one bracket sleeve for slidable engagement with a corresponding web end of the brakeshoe and having an opening for slidably receiving one of the extensions of the spindle therethrough; and (ii) at least one pawl secured to the side of the bracket sleeve for engagement with the ratchet about the spindle to permit rotation of the spindle in one direction only, the effect of which will be to restrain the combined spindle and eccentric roller(s) from turning in the direction of actuation of the cam shaft. | 5 |
BACKGROUND OF THE INVENTION
1. Field of the Invention
Embodiments of the present invention relate, in general, to removable security structures designed to prevent entry through an opening from the exterior and particularly to a security grill structure utilizing telescoping members to secure an opening and that can be easily removed from the interior.
2. Relevant Background
Society has long recognized the need to enhance the security of windows and other openings in certain geographic areas. For example, it is common to find windows and doors alike in certain urban areas fashioned with some sort of security grating or structure. While security gratings and structures have long prevented unwanted visitors from entering a dwelling or building, they have also prevented, on occasion, the occupants of such structures from making a successful egress during times of emergency.
As the result of individuals being inadvertently locked inside buildings during life-threatening situations, building codes have been adopted in many states regulating the installation and use of security structures. Most states now require buildings employing security structures to provide at least one opening for emergency egress that must be free of bars or other security structures or offer the ability to quickly remove the security devices without the use of a key, special tool or specialized knowledge.
Providing a security structure for an opening that is essentially impassable from the exterior yet easily removable from the interior, and that does not offend the aesthetics of the architecture, remains a challenge. U.S. Pat. No. 4,756,122 by Snapka and U.S. Pat. No. 6,182,397 by Almond both provide a security bar design that is removable yet both fail to blend or conceal the structure within the existing window design. There remains, therefore, a need to provide a removable security structure that can be combined with the architecture of the building so as to provide security while retaining the opening's aesthetics.
SUMMARY OF THE INVENTION
A removable security assembly comprising vertical and horizontal members is hereafter described. The long felt need of adding security to a window or similar opening yet retaining the ability to remove such security devices easily in the event of an emergency is addressed by embodiments of the present invention. Embodiments of the present invention provide a security structure that is both functional in providing an impenetrable barrier over an opening that is also internally easy to remove and aesthetically pleasing.
According to one embodiment of the present invention, a security structure comprised of members or bars arranged in a horizontal and vertical configuration is interposed between an interior sash window and an exterior sash window. Each of the horizontal and vertical members is removably coupled to a security frame. The frame, while associated with the interior and exterior sash window, is also secured to the building in a manner beyond that of normal window installation. Once installed, the combination of the vertical and horizontal members and frame provide a barrier to any unwanted entry.
Each of the horizontal bars is configured to interconnect with the vertical bars such that upon rotation of at least one of the vertical members, each horizontal member telescopically retracts from the security frame. According to one embodiment of the present invention, each horizontal member is comprised of two sub-members, whose combined length would be less than that of the opening, and a sleeve. The sleeve, which is hollow, acts to couple the two sub-members by having one end of each sub-member inserted into the sleeve. In doing so, the combination of the components extends the member over the entire opening.
Each horizontal member is further functionally coupled with at least one vertical member. Upon rotation of the vertical member, a torsional force is applied to the horizontal member causing one of the sub-member components of the horizontal member to translate longitudinally within the sleeve. The resulting movement reduces the overall length of the horizontal member and removes the ends of that member from sockets in the frame. Once the horizontal members have been uncoupled from the frame, the security structure can translate vertically and be removed from the frame.
According to one embodiment of the present invention, the vertical members include a lever or similar latch that is operable to rotate the member. In a normal configuration of the security structure and the sash windows, the interior sash window prevents rotation of the vertical members. In addition, the lever is inaccessible from the exterior sash window. Thus, according to one embodiment of the present invention, the interior sash window is removable so as to provide access to the lever and enable vertical member rotation.
The features and advantages described in this disclosure and in the following detailed description are not all-inclusive. Many additional features and advantages will be apparent to one of ordinary skill in the relevant art in view of the drawings, specification, and claims hereof. Moreover, it should be noted that the language used in the specification has been principally selected for readability and instructional purposes and may not have been selected to delineate or circumscribe the inventive subject matter; reference to the claims is necessary to determine such inventive subject matter.
BRIEF DESCRIPTION OF THE DRAWINGS
The aforementioned and other features and objects of the present invention and the manner of attaining them will become more apparent, and the invention itself will be best understood, by reference to the following description of a preferred embodiment taken in conjunction with the accompanying drawings, wherein:
FIG. 1 shows a side view of a removable security structure interposed between two sash windows according to one embodiment of the present invention;
FIG. 2A shows a front view of a security structure including a plurality of horizontal and vertical members according to one embodiment of the present invention;
FIG. 2B shows an exploded front view of the security structure of FIG. 2A having a plurality of horizontal and vertical members according to one embodiment of the present invention;
FIG. 2C shows and expanded view of a gearing design for interconnecting the vertical and horizontal members of the security structure of FIG. 2A according to one embodiment of the present invention;
FIG. 3 shows one embodiment of a security frame configured to accept a security structure according to the present invention;
FIG. 4 shows a detailed side view of the interaction with an upper vertical member and a lower vertical member according to one embodiment of the present invention; and
FIG. 5 is a side view of one embodiment of a removable security structure of the present invention interposed between two sash windows showing the removal of the interior sash window components.
The Figures depict embodiments of the present invention for purposes of illustration only. One skilled in the art will readily recognize from the following discussion that alternative embodiments of the structures and methods illustrated herein may be employed without departing from the principles of the invention described herein.
DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS
A removable security structure interposed between two sash windows is hereafter described. Embodiments of the present invention include a security structure comprised of a plurality of interconnected horizontal and vertical members. The structure is coupled to a frame anchored to the dwelling. Upon rotation of at least one of the vertical members, the horizontal members are decoupled from the frame enabling the security structure to translate vertically and inwardly so as to be removed from the frame.
Specific embodiments of the present invention are hereafter described in detail with reference to the accompanying Figures. Like elements in the various Figures are identified by like reference numerals for consistency. Although the invention has been described and illustrated with a certain degree of particularity, it is understood that the present disclosure has been made only by way of example and that numerous changes in the combination and arrangement of parts can be resorted to by those skilled in the art without departing from the spirit and scope of the invention.
1 FIG. 1 shows a side view of one embodiment of a removable security structure 100 interposed between two sash windows 140 , 150 , according to one embodiment of the present invention. The security structure is, in this exemplary rendition, comprised of a lower security structure 105 and an upper security structure 110 . The mating or juncture 180 of the upper security structure 110 to the lower security structure 105 is shown and described in more detail in FIG. 4 and related text.
The security structure 100 is interposed between an exterior sash window 150 and an interior sash window 140 . Also shown in FIG. 1 is a screen 160 or similar device to allow filtered airflow through the opening when the window is open. A sash window or hung sash window is made of one or more movable panels or “sashes” that form a frame to hold panes of glass which are often separated from other panes (or “lights”) by narrow bars. Although any window with this style of glazing is technically “a sash”, the term is used almost exclusively to refer to windows where the glazed panels are opened by sliding vertically or horizontally. Sash windows are common in Europe, the United States and many developing nations.
To facilitate operation, the weight of the glazed panel is usually balanced by a counter-weight concealed within the window frame. This is connected to the window by a sash cord or chain which runs over a pulley at the top of the frame, although spring balances are sometimes used. Sash windows may be fitted with simple hinges or the like that allow the window to be locked into hinges on one side while the counterbalance on the other site is detached, allowing the window to be opened for escape or cleaning. This includes, as is subsequently described, an interior sash that possesses tilt-in or awning features.
A double hung window refers to two sashes that can move up and down in the window frame. A single hung window has two sashes but normally the top sash is fixed and only the bottom sash slides. Triple and quadruple hung sash windows are used for tall openings, common in New England churches. While the present description is versed using sash windows as described above, one skilled in the art will appreciate that the invention is described by way of example and that other window designs, and indeed opening coverings, can be utilized with the present invention without departing from the invention's scope and intent. Furthermore, the present invention can be implemented using existing tilt in (or the like) window systems. The security structure 105 can be installed to the exterior of the window maintaining the functionality and versatility of the system without imparting the need to replace an existing window structure.
The lower security structure 105 includes a plurality of vertical members 120 and a plurality of horizontal members 130 as can be seen in more detail in FIG. 2 . FIG. 2A is a front view of one embodiment of a lower security structure 105 of the present invention. According to one embodiment of the present invention, each horizontal member 130 is comprised of a first sub-member 220 , a second sub-member 230 and an interconnecting sleeve 240 . Each sub-member 220 , 230 is of a dimension so that the combined length of the first and second sub-members 220 , 230 is less than that of the opening. Each sub-member also possesses an exterior diameter or width that is sufficiently less than that of the internal diameter of the sleeve 240 so as to allow each sub-member to freely travel within the sleeve. Furthermore, the length of the sleeve 240 with respect to the portions of the sub-members 220 , 230 is of sufficient length so as to prevent buckling at the extended most position.
As the security structure is envisioned to enhance protection from unwanted intrusion, the members and components that comprise the security structure and the frame are ideally constructed of a material that is resistant to devices or techniques that would act to cut or damage the security structure. Hardened steel, Kevlar and other material are possible options, but as one skilled in the art will recognize, a variety of material consistent with this disclosure may be used without departing from the scope and intent of the present invention.
Each vertical member 120 shown in FIG. 2A interconnects with each horizontal member 130 . According to one embodiment of the present invention, each vertical member 120 also transverses a vertical support member 250 . As will be subsequently described, the vertical support member 250 maintains the configuration of the lower security structure 105 upon removal from the opening. Each vertical member 120 also includes, according to one embodiment of the present invention, a lever 260 fixed to the vertical member 120 and operable to rotate the member.
With additional reference to FIG. 2B it can be seen that each vertical member is also comprised of sub-members. FIG. 2B shows an exploded front view of the lower security structure 105 of FIG. 2A according to one embodiment of the present invention. Each vertical member 120 in this exemplary embodiment includes an upper component 265 to which the lever 260 is attached, a mid-component 280 and a lower component 290 . As one skilled in the relevant art will appreciate, the present depiction and description of two vertical members 120 and two horizontal members 130 can be altered without departing from the scope and intent of the present invention. As the number of members increases so, too, will the number of components and sub-members. Additionally, not all of the functional relationships between the components must remain as depicted to maintain the overall functional implementation of the lower security structure 105 .
As shown, the mid-component 280 of each vertical member 120 is configured to have two geared ends 270 having a maximum diameter less than that of the external diameter of the vertical member 120 . Each geared end is accepted into a hole 285 configured with an opposing set of teeth/gears of similar diameter to that of the geared ends 270 . Thus the upper geared end 270 of the vertical mid-component 280 is received into the geared hole 285 in the upper vertical component 265 , and the lower geared end 270 of the vertical mid-component 280 is received into the geared hole 285 of the lower vertical component 290 .
Referring now in addition to FIG. 2C it can be seen that the geared end 270 of each mid-component 280 traverses an opening 275 in the sub-members 220 , 230 of each horizontal member 130 . As can be seen in the expanded view of the opening 275 , the geared portion of the vertical mid-component 280 is, in one embodiment of the present invention, geared on only a portion of the surface. The remaining portion is smooth 278 . In addition, the opening 275 in the sub-member 220 , 230 is elongated with a receiving geared portion 282 configured to mesh with the geared portion of the geared ends 270 of the vertical mid-component.
As the horizontal sub-members are not fixed in either the frame or the sleeve 240 , a rotation of the vertical member 120 will result in the geared portion of the geared ends 270 of the mid-component engaging the receiving geared portion 282 of the sub-member 220 , 230 causing the sub-member to translate consistent with the direction of rotation. Thus, as shown, a clockwise rotation of the leftmost vertical member 120 will result in the horizontal sub-member 220 extending away from the sleeve and engaging the frame. Conversely, a counter clockwise rotation of the leftmost vertical member 120 will result in the horizontal sub-member 220 retracting from the frame and extending into the sleeve. Similarly, a clockwise rotation of the rightmost vertical member 120 will also result in the horizontal sub-member 230 retracting from the frame and a counter clockwise rotation of the rightmost vertical member 120 will resulting the horizontal sub-member 230 engaging the frame. In such a manner, rotation of the vertical members 120 can retract the horizontal sub-members 220 , 230 from the frame so as to enable removal of the security structure 105 .
These and other implementation methodologies for converting rotation of one component into translation of a different component can be successfully utilized by the present invention. These implementation methodologies are known within the art and the specifics of their application within the context of the present invention will be readily apparent to one of ordinary skill in the relevant art in light of this specification. For example and according to another embodiment of the present invention, springs can be used to assert a positive force on the vertical/horizontal member interaction to ensure the sub-members stay engaged within the frame until rotation or release of the springs is initiated.
FIG. 3 shows a perspective view of one embodiment of a security frame configured to accept the security structure of the present invention. The frame 300 can be part of a modular window design or installed in a dwelling separately. The frame 300 in one embodiment comprises a plurality of sockets 310 , 320 configured to receive the ends of the horizontal and vertical security members respectively. FIG. 3 also illustrate that in one embodiment the upper portion 110 of the security structure 100 is fixed and is not removable. While not shown, other embodiments of the present invention include a duplication of the removal system described above making both the upper and lower security structures removable.
FIG. 4 shows a detailed side view of the interaction with an upper vertical member and a lower vertical member first shown in FIG. 1 according to one embodiment of the present invention. The junction 180 of the upper security structure 110 and the lower security structure 105 shows a tongue and groove type of assembly. Specifically the lower security structure 105 comprising vertical members 120 and horizontal members 130 includes a vertical support member 250 that spans the opening but is not coupled to the frame. Note that the rotational lever 260 is positioned above the vertical support member 250 . In addition, each vertical member 120 includes a vertically orientated and offset extension 410 .
As shown in FIG. 4 , the vertical extension 420 of the vertical member 120 of the lower security structure 105 slides into the channel 425 created by a similar vertically orientated and slightly offset extension 410 from the vertical member 440 of the upper security structure 110 . Note that the channel 425 is formed by an interaction between the offset extension 410 and the vertical support member 250 . Furthermore, the interaction between the vertical extension 420 and the lower extension 410 prevents lateral movement as well as vertical travel. Horizontal movement (i.e. in and out of the paper) is prevented by the interaction between the vertical members 120 , 440 and the horizontal members 130 , 430 .
As was previously described, one or more of the lower vertical members 120 is configured to rotate via use of the rotate lever 260 affixed to the top of the vertical member 120 . Upon rotation of the vertical member 120 , the lower horizontal members 130 disengage from the frame by telescopically collapsing (i.e. shortening their length). The rotation of the vertical member 120 also rotates the vertical extension 420 from out of the channel 425 and out of the confines of the lower extension 410 . In doing so, vertical movement of the lower vertical member 120 is no longer constrained. According to another embodiment of the present invention the vertical extension 420 is an integral part of the rotate lever 260 such that rotation of the lever immediate disengages the vertical extension 420 from the channel 425 .
Also shown in FIG. 4 is a gap 450 between the upper vertical member 440 and the lower vertical member 120 . Once the lower vertical member 120 is rotated and the lower extension 410 is removed from the channel 425 , the lower vertical member 120 is free to travel vertically into this gap 450 . According to one embodiment of the present invention, the lower end of each lower member 120 rests in a receiving socket 320 in the frame 300 . With the horizontal members 130 disengaged from the frame 300 and the vertical members 120 rotated, the vertical members 120 , and indeed the entire lower security structure 105 can be lifted to disengage the ends of the vertical members 120 from the lower portion of the frame 300 . Once the lower portions of the vertical members 120 are disengaged from the frame 300 the entire lower security structure 105 can be removed from the opening. Alternatively, the upper portion of the lower security structure 105 can be lowered (rotated) from the opening and removed with minimal damage or impingement to the lower frame sockets 320 . Note that the lower extension 410 and the vertical support member 250 protect the vertical extension 420 and the rotate lever 260 from tampering.
FIG. 5 is a side view of one embodiment of a removable security structure of the present invention interposed between two sash windows showing the removal of the interior sash window components. As previously described, the upper and lower security structures 110 , 105 are interposed between an external sash window/screen 150 / 160 and an interior sash window 140 . As shown in FIG. 5 , the interior sash window 140 is comprised of two or more sliding components, here an upper window 520 and a lower window 510 . In normal operation and according to one embodiment of the present invention, the lower sash travels vertically along the window frame. In another version of the present invention both the upper and lower sash windows can travel vertically along the frame. And according to another embodiment of the present invention, the interior and exterior sash windows 140 , 150 are linked such that the operation of the interior sash window 140 is mimicked by that of the exterior sash window 150 . In addition and according to another embodiment of the present invention, the lower interior window 510 and the upper interior window 520 rotate away from the upper and lower security structures 110 , 105 . Significantly the rotation of the upper and lower interior windows 520 , 510 enable access to the juncture 180 of the upper security structure 110 and the lower security structure 105 .
As can be appreciated by viewing both FIG. 1 and FIG. 5 , when the window sashes are closed, the juncture 180 of the upper security structure 110 and the lower security structure 105 is at the same level as the lower portions of the upper sash and the upper portions of the lower sash. This feature conceals the functionality of the juncture 180 from the exterior. Indeed, the upper portion of the interior sash window 510 is always in close proximity to the juncture 180 . This close proximity physically prevents the rotational lever 260 from rotating the lower vertical members 120 .
To rotate the vertical members 120 as previously described, the interior upper window sash 520 must, at a minimum, be rotated away from the juncture 180 . To accomplish the rotation of the upper window sash 520 , the lower interior window sash 510 also must be rotated away from the juncture 180 .
According to one embodiment of the present invention, to remove the lower security structure 105 from the window frame 300 , a four step process is required. First the lower portion of the interior sash window 510 is rotated away from the window frame and optionally removed. Second, the upper portion of the interior sash window 520 is rotated away from the window frame and optionally removed. These two steps provide access to the juncture 180 of the upper and lower security structures 110 , 105 .
Next, one or more of the vertical members 120 is rotated via the rotational lever 260 . This process removes the vertical extension of the lower vertical members 120 interacting with the extension and channel 410 , 425 from the upper vertical members 440 and disengages the horizontal members 130 from the frame by telescopically collapsing the member. Finally, the lower security structure 105 is lifted and/or rotated out of the opening providing free access to the exterior and an unimpeded avenue for egress.
Although the invention has been described and illustrated with a certain degree of particularity, it is understood that the present disclosure has been made only by way of example and that numerous changes in the combination and arrangement of parts can be resorted to by those skilled in the art without departing from the spirit and scope of the invention.
While there have been described above the principles of the present invention in conjunction with a removable security structure, it is to be clearly understood that the foregoing description is made only by way of example and not as a limitation to the scope of the invention. Particularly, it is recognized that the teachings of the foregoing disclosure will suggest other modifications to those persons skilled in the relevant art. Such modifications may involve other features that are already known per se and which may be used instead of or in addition to features already described herein. Although claims have been formulated in this application to particular combinations of features, it should be understood that the scope of the disclosure herein also includes any novel feature or any novel combination of features disclosed either explicitly or implicitly or any generalization or modification thereof which would be apparent to persons skilled in the relevant art, whether or not such relates to the same invention as presently claimed in any claim and whether or not it mitigates any or all of the same technical problems as confronted by the present invention. The Applicant hereby reserves the right to formulate new claims to such features and/or combinations of such features during the prosecution of the present application or of any further application derived therefrom, | A removable security structure interposed between two window configurations is comprised of interconnecting horizontal and vertical members. The vertical members engage a gear junction of the horizontal members such that upon rotation of the vertical members, the horizontal members telescopically collapse. The reduction of length of each horizontal member disengages each horizontal member from a frame housing the window configurations. The rotation of the vertical members also frees the upper portion of the vertical members of the security structure. With the upper and side portions of the security structure freed, the security structure can be rotated and removed from the frame allowing egress. | 4 |
BACKGROUND OF THE INVENTION
Field of Invention
The present invention relates to the field of optical communications, and in particular, to a circuit for realizing passivation of an intelligent optical distribution interface disc in a machine disc enable manner.
Related Art
Pushed by FTTH (Fiber-To-The-Home, fiber-to-the-home) construction, an ODN (Optical Distribution Network, optical distribution network) embraces explosive growth. Because the FTTH mainly adopts a PON (Passive Optical Network, passive optical network) technology, which splits an OLT (Optical Line Terminal, optical line terminal) to dozens or hundreds of ONUs (Optical Network Unit, optical network unit), therefore a user end of the ODN network generates a large number of optical fiber lines, and distribution scheduling, maintenance, and management need to be performed.
Earlier optical cable lines are basically all point-to-point lines and the management is relatively easy. However, the ODN network serving the FTTH is a point-to-multipoint line, and continues to use a current character label only artificially identifiable to perform optical fiber distribution management, and thereby maintenance workload and management difficulty thereof are greatly increased. In addition, the PON technology has a one-to-many optical network feature. Therefore, on an optical branch network, a user may freely access to any branch to perform normal signal transmission, without being perceived by a network administrator. This feature makes manageability of the ODN greatly decrease. A loophole of artificial management will cause an error of inconsistency between network data and an actual network status. This bearer brings a lot of difficulties to subsequent network maintenance work.
To solve this problem, an intelligent ODN optical distribution management technology appears. This technology, based on an electronic label, gives each optical fiber moveable connector an ID chip with a globally unique code, manages optical fiber distribution in an electronic automatic collection manner, so as to eliminate the error that possibly occurs during the artificial management, and uses a computer network technology to provide guidance on optical distribution network maintenance. Thereby, a port needing to be operated may be highlighted among densely arranged distribution frame adapter arrays, to reduce labor strength.
To read electronic label information of the moveable connector inserted into the optical fiber adapter, on an optical distribution disc (or board or card, which is an independent structural unit body, and hereinafter is uniformly called the disc with differences among the disc, board, and card being omitted,), an appropriate optical port is needed, and additionally corresponding port drive and read-write circuits are also needed, so as to receive a signal sent by a management disc, drive the port of this disc to perform an relevant operation, and report insertion information of the optical fiber moveable connector to the management disc.
The drive and read-write circuits all include a certain number of digital integrated circuit chips, and these circuits all have certain static electricity protection limitations and anti-short circuit capability limitations.
To simplify designs of an ODF (Optical Distribution Frame, optical distribution frame) and an optical fiber cross connecting cabinet, in most cases, the designs of a fiber fusion function and a distribution function are required to be realized on one machine disc, that is, a fusion-distribution integration. In this case, during onsite construction of the ODN network, the optical distribution disc needs to be taken out for optical fiber fusion splice. Thereby, a machine disc circuit is exposed to a natural space environment, may not be protected by a device cabinet, and is easily encroached by static electricity.
Additionally, because the optical fiber cross connecting cabinets mostly work in an open-air environment, and the circuit will be contaminated by muddy water during construction on a rainy day, reducing insulation performance of the circuit, thereby the functions and features of the circuit are affected, and even a component such as a chip is damaged due to a short circuit. Because FTTH projects are widely carried out, onsite environments are in great variety, working levels of construction persons are different, and the foregoing cases are extremely difficult to be avoided, therefore, how to improve anti-static capability and fouling-resistant capability of a device is a very important aspect for preventing damage of an intelligent ODN device and improving reliability thereof.
Because basically only fiber fusion work is performed during the onsite construction of an optical distribution device, but what intelligent optical fiber distribution management deals with is electronized management of distribution information, so adopting a fusion-distribution separation manner may solve the foregoing problems well. That is, electronic circuits needed by intelligentized management are all designed onto a distribution machine disc, and a fiber fusion machine disc is taken independent and is connected through an optical fiber. In this way, during the onsite construction of the device, only a fiber fusion disc without the electronic circuit is processed, but a distribution disc circuit vulnerable to fouling and the static electricity is prohibited from onsite processing. In this way, the device may be protected from the damage by the onsite construction. However, this processing manner still has the following problems:
(1) Fusion-distribution separation deviates from a development direction of fusion-distribution integration, and reduces installation density of the device.
(2) A distribution disc is not without an optical fiber fusion splice point, but fusion splice is performed during device production, to prevent onsite fusion splice. However, the fusion splice point still fails to be free from a default during device running, and is still endangered by the fouling and static electricity harm during the onsite construction.
(3) A section of optical cable is added between the fiber fusion disc and the distribution disc, increasing device cost.
(4) After the fiber fusion disc is separated, a fiber fusion component still needs to be configured on the distribution disc, further increasing the device cost.
(5) The optical fiber fusion splice point is added to the device, increasing line loss, and reducing the reliability.
(6) A fiber fusion operation on the distribution disc adds a procedure of the device production, increasing production cost of the device.
(7) The optical cable between the fiber fusion disc and the distribution disc limits onsite operation space of fiber fusion construction, being unfavorable to improve onsite construction efficiency.
Therefore, the fusion-distribution separation manner for designing an intelligent optical distribution device may though solve the problem of the fouling and the static electricity harm during the onsite construction to a certain extent, but at the same time brings a series of other problems, limiting the development of the device and technology, limiting improvement of the onsite construction efficiency, increasing the production cost of the device, and raising a higher requirement for the onsite construction persons and a higher requirement for a management system; and these harms fail to be complete eradicated.
Another method is that: the optical distribution disc is installed in a rigorously designed protective shell, but a rear panel interface and an optical distribution interface of the machine disc must be exposed, and therefore the exposed circuit hard to be shielded still exists. Although the reliability of the optical distribution disc may be improved to a certain extent, accompanied increase of the cost cannot provide perfect circuit protection.
In summary, introduction of an electronic label technology into the ODN network for distribution management has an obvious advantage, but it requires the circuit to be arranged on an optical fiber distribution disc for identity information management of the distribution optical fiber connector. A defect of the electronic circuit being easily harmed by the static electricity and damaged by swage and the short circuit makes the distribution device difficult to withstand an impact of a harsh work environment for the onsite construction of the device, very easily causing the damage of the machine disc. Both a fusion-distribution separation design scheme and a scheme of adding a protective shell to the machine disc may alleviate the foregoing problems, but at the same time it brings a series of other problems, limiting the development of the device and technology, limiting the improvement of the onsite construction efficiency, and protecting the device not so closely. Therefore, no matter whether the fusion-distribution separation is required, the anti-static capability and fouling-resistant capability of an intelligent optical distribution disc must be able to be improved, and a good protection capability must be able to be provided for an interface that fails to be protected by a shell. Only in this way, the reliability of the device may be fundamentally increased. Undoubtedly, this is a very difficult technical problem that needs urgent settlement.
SUMMARY
The present invention aims to overcome a deficiency of the foregoing background technology, and provides a circuit for realizing passivation of an intelligent optical distribution interface disc in a machine disc enable manner. No matter whether in a fusion-distribution integration or fusion-distribution separation design, in an onsite construction phase, a distribution disc has both strong anti-static capability and fouling-resistant capability. When the fusion-distribution integration design is used, the device cost can be reduced, the device production process can be reduced, and the device performance and the distribution density can be increased. When the fusion-distribution separation design is used, even an optical fiber fusion splice point on the distribution disc generates failure, over-high requirements may not be put forward for maintenance and construction.
1The circuit for realizing passivation of an intelligent optical distribution interface disc in a machine disc enable manner provided by the present invention includes an intelligent distribution management disc and several distribution interface discs respectively connected to the intelligent distribution management disc, and further includes a port read-write bus and several machine disc enable lines. All distribution interface discs are passivated distribution interface discs, where the passivated distribution interface discs are connected respectively through a machine disc enable line to the intelligent distribution management disc, and the intelligent distribution management disc is further connected through the port read-write bus to the passivated distribution interface discs. All the passivated distribution interface discs are uniformly managed in a matrix manner.
2In the foregoing technical solution, the passivated distribution interface disc comprises several distribution information read-write interfaces and several distribution port indicators; each distribution information read-write interface comprises a reference control end and a signal read-write end; each distribution port indicator comprises a reference management end and a display control end; the intelligent distribution management disc uniformly manages a read-write operation of optical fiber distribution information of any distribution information read-write interface in each passivated distribution interface disc, and controls display information of the corresponding distribution port indicator.
3In the foregoing technical solution, the reference control end of each distribution information read-write interface and the reference management end of each distribution port indicator may be connected to a ground cable.
4In the foregoing technical solution, the reference control end of each distribution information read-write interface and the reference management end of each distribution port indicator may be connected to a power supply.
5In the foregoing technical solution, the intelligent distribution management disc may adopt a grouped port control manner to manage the distribution information read-write interfaces and the distribution port indicators.
6In the foregoing technical solution, the intelligent distribution management disc includes a port information read-write module, a port instruction control module and a machine disc enable control module. The port information read-write module draws forth several distribution information read-write lines. A signal read-write end of a distribution information read-write interface with a same port number in each passivated distribution interface disc is respectively connected parallel to the distribution information read-write line corresponding to the port number. The port instruction control module draws forth several port instruction control lines. A display control end of a distribution port indicator with the same port number in each passivated distribution interface disc is respectively connected parallel to the port instruction control line corresponding to the port number. Each distribution information read-write line and each port instruction control line jointly form a port read-write bus.
7In the foregoing technical solution, the machine disc enable control module in the intelligent distribution management disc adopts a combined machine disc enable manner to manage the distribution information read-write interfaces and the distribution port indicators.
8In the foregoing technical solution, the reference control end of each distribution information read-write interface in the passivated distribution interface disc is connected to the reference management end of each distribution port indicator, to form the machine disc enable line of the passivated distribution interface disc. The machine disc enable line of each passivated distribution interface disc is connected to the machine disc enable control module is connected to the machine disc enable control module 8 in the intelligent distribution management disc.
9In the foregoing technical solution, the machine disc enable control module in the intelligent distribution management disc adopts a grouped machine disc enable manner according to a certain rule to manage each distribution information read-write interface and each distribution port indicator.
10In the foregoing technical solution, the machine disc enable lines are grouped into a machine disc read-write enable line and a machine disc instruction enable line. The reference control end of each distribution information read-write interface in a passivated distribution interface disc is connected as a machine disc read-write enable line of the passivated distribution interface disc. The reference management end of each distribution port indicator in each passivated distribution interface disc is connected as a machine disc instruction enable line of the passivated distribution interface disc. The machine disc read-write enable line and the machine disc instruction enable line of each passivated distribution interface disc are connected to a machine disc enable control module in the intelligent distribution management disc.
11In the foregoing technical solution, the machine disc enable lines are divided into several machine disc read-write grouping enable lines and several machine disc instruction grouping enable lines. The distribution information read-write interfaces in each passivated distribution interface disc are divided into at least two groups according to a rule formulated in advance. The reference control ends of the distribution information read-write interfaces grouped into a same group are connected as the machine disc read-write grouping enable line of the distribution information read-write interfaces of this group. The distribution port indicators in each passivated distribution interface disc are also divided into at least two groups according to the same rule. The reference management ends of the distribution port indicators grouped into a same group are connected as the machine disc instruction grouping enable line of the distribution port indicators of this group. All machine disc read-write grouping enable lines and machine disc instruction grouping enable lines are connected to the machine disc enable control module in the intelligent distribution management disc.
12In the foregoing technical solution, the distribution information read-write interfaces and distribution port indicators in each passivated distribution interface disc are respectively divided into two groups according to parity of a port number. The distribution information read-write interfaces whose port number is an odd number is grouped to form a group, the distribution information read-write interfaces whose port number is an even number is grouped to form a group, the distribution port indicators whose port number is the odd number is grouped to form a group, and the distribution port indicators whose port number is the even number is grouped to form a group. The reference control ends of the distribution information read-write interfaces grouped into the same group are connected to form the machine disc read-write grouping enable line of the distribution information read-write interfaces of this group. The reference management ends of the distribution port indicators grouped into the same group are connected to form the machine disc instruction grouping enable line of the distribution port indicators of this group. All machine disc read-write grouping enable lines and all machine disc instruction grouping enable lines of each passivated distribution interface disc are connected to the machine disc enable control module in the intelligent distribution management disc.
13In the foregoing technical solution, the distribution information read-write interfaces and distribution port indicators in each passivated distribution interface disc are evenly divided into at least two groups respectively in an ascending order or a descending order of the port numbers. The reference control ends of each distribution information read-write interface grouped into a same group are connected to form at least two machine disc read-write grouping enable lines of the passivated distribution interface disc where the distribution information read-write interface is located. The reference management ends of each distribution port indicator grouped into a same group are connected to form at least two machine disc instruction grouping enable lines of the passivated distribution interface disc where the distribution port indicator is located. All machine disc read-write grouping enable lines and all machine disc instruction grouping enable lines of each passivated distribution interface disc are connected to the machine disc enable control module in the intelligent distribution management disc.
14In the foregoing technical solution, the machine disc enable lines are grouped into several machine disc grouping enable lines whose functions are basically the same. In each passivated distribution interface disc, the distribution information read-write interface whose port number is an odd number and the distribution port indicator whose port number is the odd number match each other and are grouped into a same group. In each passivated distribution interface disc, the distribution information read-write interface whose port number is an even odd number and the distribution port indicator whose port number is the even number match each other and are grouped into a same group. The reference control ends of each distribution information read-write interface grouped into the same group and the reference management ends of each distribution port indicator grouped into the same group are connected, to form one machine disc grouping enable line corresponding to this group. All machine disc grouping enable lines are connected to the machine disc enable control module in the intelligent distribution management disc.
15In the foregoing technical solution, the machine disc enable lines are grouped into several machine disc grouping enable lines whose functions are basically the same. Each distribution information read-write interface and each distribution port indicator in each passivated distribution interface disc are evenly divided into at least two groups respectively in an ascending order or a descending order of the port numbers. The distribution information read-write interface and the distribution port indicator with the same port numbers match each other and are grouped into a same group. The reference control ends of each distribution information read-write interface in each group the reference management ends of each distribution port indicator in this group are connected, to form one machine disc grouping enable line corresponding to this group. All machine disc grouping enable lines are connected to the machine disc enable control module in the intelligent distribution management disc.
16In the foregoing technical solution, the intelligent distribution management disc includes a port information read-write module, a port instruction control module, and the machine disc enable control module. The port information read-write module draws forth several distribution information read-write lines, and numbers the several distribution information read-write lines in sequence. The port instruction control module draws forth several port instruction control lines, and numbers the several port instruction control lines in sequence. Each numbered distribution information read-write line and each numbered port instruction control line jointly form a port read-write bus. The machine disc enable control module adopts the grouped machine disc enable manner according to a certain rule to manage each distribution information read-write interface and each distribution port indicator.
17In the foregoing technical solution, the machine disc enable lines are grouped into several machine disc grouping enable lines whose functions are basically the same. In each passivated distribution interface disc, the distribution information read-write interface whose port number is an odd number and the distribution port indicator whose port number is the odd number match each other and are grouped into a same group. In each passivated distribution interface disc, the distribution information read-write interface whose port number is an even number and the distribution port indicator whose port number is the even number match each other and are grouped into a same group. The reference control ends of each distribution information read-write interface grouped into the same group and the reference management ends of each distribution port indicator grouped into the same group are connected, to form one machine disc grouping enable line corresponding to this group. All machine disc grouping enable lines are connected to the machine disc enable control module in the intelligent distribution management disc.
18In the foregoing technical solution, the machine disc enable lines are grouped into several machine disc grouping enable lines whose functions are basically the same. Each distribution information read-write interface and each distribution port indicator in each passivated distribution interface disc are evenly divided into at least two groups respectively in an ascending order or a descending order of the port numbers. The distribution information read-write interface and the distribution port indicator with the same port numbers match each other and are grouped into a same group. The reference control ends of each distribution information read-write interface in each group the reference management ends of each distribution port indicator in this group are connected, to form one machine disc grouping enable line corresponding to this group. All machine disc grouping enable lines are connected to the machine disc enable control module in the intelligent distribution management disc.
19In the foregoing technical solution, after each distribution information read-write interface and each distribution port indicator in the passivated distribution interface disc are grouped according to a certain rule, in each group of each in each passivated distribution interface disc, the ports are grouped and numbered in sequence again. The signal read-write ends of each distribution information read-write interface with a same group number between each group in each passivated distribution interface disc are jointly connected parallel to the distribution information read-write line that the port information read-write module draws forth and is corresponding to this group number. The display control ends of each distribution port indicator with the same group number between each group in each passivated distribution interface disc are jointly connected parallel to the port instruction control line that the port instruction control module draws forth and is corresponding to this group number.
20In the foregoing technical solution, the intelligent distribution management disc adopts a combined port control management manner to manage the distribution information read-write interfaces and the distribution port indicators.
21In the foregoing technical solution, the intelligent distribution management disc includes the port information read-write module and the machine disc enable control module. The port information read-write instruction control module draws forth several port read-write control lines. In each passivated distribution interface disc, the signal read-write end of the distribution information read-write interface and the display control end of the distribution port indicator that have a same port number are jointly connected parallel to the port read-write control line corresponding to the port number. Each port read-write control line jointly forms the port read-write bus. The port information read-write instruction control module in the intelligent distribution management disc performs port combination, control, and management on the distribution information read-write interface and the distribution port indicator in each passivated distribution interface disc.
22In the foregoing technical solution, the machine disc enable control module in the intelligent distribution management disc adopts the grouped machine disc enable manner according to a certain rule to manage the distribution information read-write interfaces and the distribution port indicators.
23In the foregoing technical solution, the machine disc enable lines are grouped into a machine disc read-write enable line and a machine disc instruction enable line. The reference control end of each distribution information read-write interface in the passivated distribution interface disc is connected as the machine disc read-write enable line of the passivated distribution interface disc. The reference management end of each distribution port indicator is connected as the machine disc instruction enable line of the passivated distribution interface disc. The machine disc read-write enable line and the machine disc instruction enable line of each passivated distribution interface disc are connected to the machine disc enable control module in the intelligent distribution management disc.
24In the foregoing technical solution, the machine disc enable lines are divided into several machine disc read-write grouping enable lines and several machine disc instruction grouping enable lines. The distribution information read-write interfaces in each passivated distribution interface disc are divided into at least two groups according to a rule formulated in advance. The reference control ends of the distribution information read-write interfaces grouped into a same group are connected as the machine disc read-write grouping enable line of the distribution information read-write interfaces of this group. The distribution port indicators in each passivated distribution interface disc are also divided into at least two groups according to the same rule. The reference management ends of the distribution port indicators grouped into a same group are connected as the machine disc instruction grouping enable line of the distribution port indicators of this group. All machine disc read-write grouping enable lines and machine disc instruction grouping enable lines are connected to the machine disc enable control module in the intelligent distribution management disc.
25In the foregoing technical solution, the distribution information read-write interfaces and distribution port indicators in each passivated distribution interface disc are respectively divided into two groups according to parity of a port number. The distribution information read-write interfaces whose port number is an odd number is grouped to form a group, the distribution information read-write interfaces whose port number is an even number is grouped to form a group, the distribution port indicators whose port number is the odd number is grouped to form a group, and the distribution port indicators whose port number is the even number is grouped to form a group. The reference control ends of the distribution information read-write interfaces grouped into the same group are connected to form the machine disc read-write grouping enable line of the distribution information read-write interfaces of this group. The reference management ends of the distribution port indicators grouped into the same group are connected to form the machine disc instruction grouping enable line of the distribution port indicators of this group. All machine disc read-write grouping enable lines and all machine disc instruction grouping enable lines of each passivated distribution interface disc are connected to the machine disc enable control module in the intelligent distribution management disc.
26In the foregoing technical solution, the distribution information read-write interfaces and distribution port indicators in each passivated distribution interface disc are evenly divided into at least two groups respectively in an ascending order or a descending order of the port numbers. The reference control ends of each distribution information read-write interface grouped into a same group are connected to form at least two machine disc read-write grouping enable lines of the passivated distribution interface disc where the distribution information read-write interface is located. The reference management ends of each distribution port indicator grouped into a same group are connected to form at least two machine disc instruction grouping enable lines of the passivated distribution interface disc where the distribution port indicator is located. All machine disc read-write grouping enable lines and all machine disc instruction grouping enable lines of each passivated distribution interface disc are connected to the machine disc enable control module in the intelligent distribution management disc.
27In the foregoing technical solution, the intelligent distribution management disc further draws forth a disc in-position monitoring line; each passivated distribution interface disc further includes a disc in-position instruction signal line; one end of the disc in-position instruction signal line is connected through an unidirectional level clamper to any one of the machine disc enable lines, machine disc read-write enable lines, machine disc instruction enable lines, machine disc grouping enable lines, machine disc read-write grouping enable lines, or machine disc instruction grouping enable lines of the passivated distribution interface disc where the disc in-position instruction signal line is located, and the other end is connected to the disc in-position monitoring line.
28In the foregoing technical solution, the intelligent distribution management disc further draws forth several disc in-position monitoring lines; each passivated distribution interface disc further comprises the disc in-position instruction signal line; one end of the disc in-position instruction signal line is grounded, and the other end is connected through the disc in-position monitoring line to a disc in-position monitoring end corresponding to the intelligent distribution management disc, to perform independent disc in-position monitoring.
29In the foregoing technical solution, the intelligent distribution management disc further includes an interface disc type monitoring module; the interface disc type monitoring module is a CPLD, an FPGA, or an input bus of a microprocessor and a software management logic thereof having or not having a disc in-position instruction function. Each passivated distribution interface disc further includes a disc type encoder and several interface disc type instruction lines. One end of each interface disc type instruction line is connected through the disc type encoder to any one of the machine disc enable lines, machine disc read-write enable lines, machine disc instruction enable lines, machine disc grouping enable lines, machine disc read-write grouping enable lines, or machine disc instruction grouping enable lines of the passivated distribution interface disc where the interface disc type instruction line is located, and the other end is connected to the disc type instruction line corresponding to another passivated distribution interface disc according to code position configuration for a code of the instruction line, to form a disc type monitoring line; the disc type monitoring line is connected to the interface disc type monitoring module.
30In the foregoing technical solution, the intelligent distribution management disc further draws forth several disc in-position monitoring lines; each passivated distribution interface disc further comprises the disc in-position instruction signal line; one end of the disc in-position instruction signal line is grounded, and the other end is connected through the disc in-position monitoring line to the disc in-position monitoring end corresponding to the intelligent distribution management disc, to perform the independent disc in-position monitoring. The intelligent distribution management disc further includes the interface disc type monitoring module; the interface disc type monitoring module is the CPLD, the FPGA, or the input bus of the microprocessor and the software management logic thereof not having the disc in-position instruction function. Each passivated distribution interface disc further includes a disc type encoder and several interface disc type instruction lines. One end of each interface disc type instruction line is connected through the disc type encoder to any one of the machine disc enable lines, machine disc read-write enable lines, machine disc instruction enable lines, machine disc grouping enable lines, machine disc read-write grouping enable lines, or machine disc instruction grouping enable lines of the passivated distribution interface disc where the interface disc type instruction line is located, and the other end is connected to the disc type instruction line corresponding to another passivated distribution interface disc according to code position configuration for the code of the instruction line, to form the disc type monitoring line; the disc type monitoring line is connected to the interface disc type monitoring module.
31In the foregoing technical solution, the port information read-write module is the complex programmable logic device CPLD, the field programmable gate array FPGA, or the read-write bus of the microprocessor and the software management logic device thereof.
32In the foregoing technical solution, the port instruction control module is the CPLD, the FPGA, or an output bus of the microprocessor and a software management device thereof.
33In the foregoing technical solution, the port information read-write instruction control module is the CPLD, the FPGA, the read-write bus of the microprocessor and the software management logic device thereof, or the output bus of the microprocessor and the software management device thereof.
34In the foregoing technical solution, the machine disc enable control module 8 is an analog switch or a field-effect pipe controlled through a programmable hardware management logic of the CPLD or the FPGA or the output bus of the microprocessor and the software management logic, a high frequency enable controller with a radio frequency identification RFID, or a logic output device with high resistance forbidding or low level absorption current/high level supply current enable.
35In the foregoing technical solution, the distribution information read-write interface is an optical fiber adapter with a capability of reading identity information on an optical fiber moveable connector.
36In the foregoing technical solution, a carrier of the identity information on the optical fiber moveable connector is the RFID or an eID chip.
37In the foregoing technical solution, when the carrier of the identity information on the optical fiber moveable connector is an eID chip, the reference control end and signal read-write end of the distribution information read-write interface are both metal plug-in springs.
38In the foregoing technical solution, when the carrier of the identity information on the optical fiber moveable connector is an RFID, an information read-write antenna is configured between the reference control end and signal read-write end of the distribution information read-write interface.
39In the foregoing technical solution, the distribution port indicator is an indicator, a light emitting diode LED or a liquid crystal display LCD.
40In the foregoing technical solution, the unidirectional level clamper may be a diode or a unidirectional level damper circuit.
Compared with the prior art, advantages of the present invention are as follows:
(1) In the present invention, a distribution port is separated from distribution management, all management circuits on a distribution interface disc are moved out, and all control and management functions are achieved on a distribution management disc, to enable passivation to be performed on a distribution interface disc circuit, i.e. any active electronic devices such as integrated circuits, triodes, etc. which are easily damaged by static electricity and affected by fouling are not placed on the distribution interface disc any longer, and power lines are not introduced in the distribution interface disc. No matter whether in the fusion-distribution integration or fusion-distribution separation design, during the onsite construction, the distribution disc has both the strong anti-static capability and fouling-resistant capability.
(2) A passivation design of the circuit for an intelligent ODN distribution device interface disc may greatly increase the anti-static capability and fouling-resistant capability of the machine disc. In this way, no matter whether in the fusion-distribution integration or fusion-distribution separation design, the distribution device do not need to raise a special protection requirement for the distribution interface disc during the device onsite construction. Therefore limitations on a site and persons of the onsite construction may be reduced, and construction efficiency and convenience may be improved. There is no active electronic device on the machine disc. Therefore, no protective shell needs to be added to the machine disc, and an exposed rear panel interface and optical distribution interface of the machine disc naturally have the very strong anti-static capability and fouling-resistant capability without special protection. In this way, after the machine disc is pulled out, static protection may not need to be considered. Slight fouling or damage will not cause device damage and even not affect normal work of the device, as long as a short circuit resistance is not too small.
(3) When the fusion-distribution integration design is used by the device, the device cost can be reduced, the device production process can be reduced, and the device performance and the distribution density can be increased.
(4) When the fusion-distribution separation design is used by the device, even the optical fiber fusion splice point on the distribution disc generates the failure, the over-high requirements may not be put forward for the maintenance and construction.
(5) The distribution disc almost does not consume electrical energy after being passivated, and there are a large number of distribution interface discs in an intelligent distribution device, which is greatly helpful for reducing energy consumption of the device and extending continuous power supply work time.
The foregoing advantages have very important and positive significance for improving the reliability of the device, extending a service life of the device, and reducing the cost of purchasing, the construction, and the maintenance of a system and the device.
BRIEF DESCRIPTION OF THE DRAWINGS
FIG. 1 is an overall schematic structural diagram of a circuit for realizing passivation of an intelligent optical distribution interface disc in a machine disc enable manner according to embodiments of the present invention;
FIG. 2 is a circuit diagram according to embodiment 1.1 of the present invention;
FIG. 3 is a circuit diagram inside a passivated distribution interface disc according to embodiment 1.1 of the present invention;
FIG. 4 is a circuit diagram according to embodiment 1.2 of the present invention;
FIG. 5 is a circuit diagram inside a passivated distribution interface disc according to embodiment 1.2 of the present invention;
FIG. 6 is a circuit diagram according to embodiment 1.5 of the present invention;
FIG. 7 is a circuit diagram according to embodiment 1.7 of the present invention;
FIG. 8 is a circuit diagram according to embodiment 1.9 of the present invention;
FIG. 9 is a circuit diagram inside a passivated distribution interface disc according to embodiment 1.9 of the present invention;
FIG. 10 is a circuit diagram according to embodiment 2.1 of the present invention;
FIG. 11 is a circuit diagram inside a passivated distribution interface disc according to embodiment 2.1 of the present invention;
FIG. 12 is a circuit diagram inside a passivated distribution interface disc according to embodiment 2.9 of the present invention;
FIG. 13 is a circuit diagram according to embodiment 3.1 of the present invention;
FIG. 14 is a circuit diagram inside a passivated distribution interface disc according to embodiment 3.1 of the present invention;
FIG. 15 is a circuit diagram inside a passivated distribution interface disc according to embodiment 3.9 of the present invention;
FIG. 16 is a circuit diagram according to embodiment 4.1 of the present invention;
FIG. 17 is a circuit diagram inside a passivated distribution interface disc according to embodiment 4.1 of the present invention;
FIG. 18 is a circuit diagram inside a passivated distribution interface disc according to embodiment 4.9 of the present invention;
FIG. 19 is a circuit diagram according to embodiment 5.1 of the present invention; and
FIG. 20 is a circuit diagram inside a passivated distribution interface disc according to embodiment 5.9 of the present invention.
In the figures: 1 —intelligent distribution management disc, 2 —passivated distribution interface disc, 3 —distribution information read-write interface, 4 —distribution port indicator, 5 —disc type encoder, 6 —port information read-write module, 7 —port instruction control module, 8 —machine disc enable control module, 9 —interface disc type monitoring module, 10 —port information read-write instruction control module, and 11 —unidirectional level clamper.
DETAILED DESCRIPTION OF THE INVENTION
The following, with reference to attached figures and embodiments, further describes in detail the present invention.
Referring to FIG. 1 , the circuit for realizing passivation of an intelligent optical distribution interface disc in a machine disc enable manner provided by embodiments of the present invention includes an intelligent distribution management disc 1 and several distribution interface discs respectively connected to the intelligent distribution management disc 1 , and a port read-write bus and several machine disc enable lines. All distribution interface discs are passivated distribution interface discs 2 , where the passivated distribution interface discs 2 are connected respectively through a machine disc enable line to the intelligent distribution management disc 1 , and the intelligent distribution management disc 1 is further connected through the port read-write bus to the passivated distribution interface discs 2 . Ports of all the passivated distribution interface discs 2 are uniformly managed in a matrix manner.
Referring to FIG. 2 , the passivated distribution interface discs 2 include several distribution information read-write interfaces 3 and several distribution port indicators 4 , where each distribution information read-write interface 3 includes a reference control end and a signal read-write end, and each distribution port indicator 4 includes a reference management end and a display control end. The reference control ends of all the distribution information read-write interfaces 3 and the reference management ends of all the distribution port indicators 4 may be all connected to a ground cable or to a power supply.
The distribution information read-write interface 3 is an optical fiber adapter with a capability of reading identity information on an optical fiber moveable connector. A carrier of the identity information on the optical fiber moveable connector is an RFID (Radio Frequency Identification, radio frequency identification, also called a wireless electronic label) or an eID chip. When the carrier of the identity information on the optical fiber moveable connector is an eID chip, the reference control end and signal read-write end of the distribution information read-write interface 3 are both metal plug-in springs; when the carrier of the identity information on the optical fiber moveable connector is an RFID, an information read-write antenna is configured between the reference control end and signal read-write end of the distribution information read-write interface 3 . A distribution port indicator 4 is an indicator, an LED (Light Emitting Diode, light emitting diode) or an LCD (Liquid Crystal Display, liquid crystal display).
To further increase a port management capacity of a bus, or to manage the ports by type, various port devices needing to be managed may be grouped for management; to decrease the number of the buses, read-write control lines in different groups may further be combined, controlled, and managed according to a certain rule. In other words, the intelligent distribution management disc 1 may control the ports not only in a grouped port control manner, but also in a combined port control manner. On a basis of selecting the grouped port control manner, the intelligent distribution management disc 1 may enable the machine disc not only in a combined machine disc enable manner, but also in a grouped machine disc enable manner. On a basis of selecting the combined port control manner, the intelligent distribution management disc 1 may enable the machine disc in the grouped machine disc enable manner according to a certain rule. The grouped machine disc enable manner may be broken down into several types according to different grouping rules. For example, the ports of the distribution information read-write interface 3 and the distribution port indicator 4 may be respectively connected to form a group, and the ports of the distribution information read-write interface 3 and the distribution port indicator 4 may be also be divided into 2 groups respectively according to parity of a port number, or may be evenly divided into two or more groups respectively in an ascending order or a descending order of port numbers, to respectively perform grouped machine disc enable control.
On a basis of selecting the grouped machine disc enable control, combination may be performed for port control. All distribution information read-write interfaces 3 and all distribution port indicators 4 managed by different grouping enable lines respectively connect signal read-write ends or display control ends with the same number or the same group number in sequence to performs port combination, control, and management, and finally form various basic circuits that have only one distribution information read-write interface 3 or one distribution port indicator 4 at each cross point of a port control management line and a machine disc enable (or grouping enable) line, to uniformly manage a read-write operation of optical fiber distribution information of any distribution information read-write interface 3 in the passivated distribution interface discs 2 , and control display information of the corresponding distribution port indicator 4 .
In addition, on a basis of forming the foregoing various basic circuits, to enable the intelligent distribution management disc 1 and a upper-layer network management system thereof to know which distribution disc positions are installed with the passivated distribution interface discs 2 , and a disc in-position instruction signal line (further divided into 2 connection manners) may further be configured on each passivated distribution interface disc 2 , so that the disc position of this disc may be reported through the disc in-position instruction signal line. Because the passivated distribution interface discs 2 have multiple types, to make the intelligent distribution management disc 1 and the upper-layer network management system thereof perceive and discern the types of the passivated distribution interface discs 2 , an interface disc type instruction line may be configured on each passivated distribution interface disc 2 , so that the disc type of this disc may be reported through the interface disc type instruction line. A more preferable scheme may be adopted, to report the disc position and disc type of this disc at the same time.
The following respectively describes, through 11 specific embodiments, the basic circuits that adopt grouped/combined port control or grouped/combined machine disc enable.
Embodiment 1.1: Grouped Port Control+Combined Machine Disc Enable
Referring to FIG. 2 , a basic circuit connection of a grouped port control manner is as follows: an intelligent distribution management disc 1 includes a port information read-write module 6 , a port instruction control module 7 and a machine disc enable control module 8 . The port information read-write module 6 draws forth several distribution information read-write lines. Signal read-write ends of distribution information read-write interfaces 3 with the same port number in all the passivated distribution interface discs 2 are respectively connected in parallel to the distribution information read-write line corresponding to the port number; the port instruction control module 7 draws forth several port instruction control lines. Display control ends of distribution port indicators 4 with the same port number in all the passivated distribution interface discs 2 are respectively connected in parallel to the port instruction control line corresponding to the port number. All the distribution information read-write lines and all the port instruction control lines jointly form a port read-write bus.
The port information read-write module 6 is a CPLD (Complex Programmable Logic Device, complex programmable logic device), an FPGA (Field Programmable Gate Array, field programmable gate array), or a read-write bus of a microprocessor and a software management logic device thereof. The port instruction control module 7 is the CPLD, the FPGA, or an output bus of the microprocessor and a software management device thereof. The machine disc enable control module 8 is an analog switch or an MOS pipe (field-effect pipe) controlled through a programmable hardware management logic of the CPLD or the FPGA or the output bus of the microprocessor and a software management logic, a high frequency enable controller with a radio frequency identification RFID, or a logic output device with high resistance forbidding or low level absorption current (or high level supply current) enable.
On a basis of the grouped port control manner, the basic circuit connection of a combined machine disc enable manner is as follows: referring to FIG. 3 , the reference control ends of all the distribution information read-write interfaces 3 in the passivated distribution interface discs 2 are connected to the reference management ends of all the distribution port indicators 4 , to form the machine disc enable lines of the passivated distribution interface discs 2 . The machine disc enable lines of all the passivated distribution interface disc 2 are connected to the machine disc enable control module 8 in the intelligent distribution management disc 1 .
Embodiment 1.2: Grouped Port Control+Grouped Machine Disc Enable (Respectively Connected to Form a Group)
Referring to FIG. 4 and FIG. 5 , on a basis of the grouped port control manner in embodiment 1.1, each original machine disc enable line is divided into a machine disc read-write enable line and a machine disc instruction enable line. The reference control ends of all the distribution information read-write interfaces 3 in the passivated distribution interface discs 2 are connected as machine disc read-write enable lines of the passivated distribution interface discs 2 . The reference management ends of all the distribution port indicators 4 are connected as machine disc instruction enable lines of the passivated distribution interface discs 2 . The machine disc read-write enable lines and the machine disc instruction enable lines of all the passivated distribution interface discs 2 are connected to a machine disc enable control module 8 in the intelligent distribution management disc 1 .
Embodiment 1.3: Grouped Port Control+Grouped Machine Disc Enable (2 Groups Respectively for an Odd Number and an Even Number)
On a basis of the grouped port control manner in embodiment 1.1, the machine disc enable line is divided into a machine disc read-write grouping enable line and a machine disc instruction grouping enable line. The distribution information read-write interfaces 3 and distribution port indicators 4 in each passivated distribution interface disc 2 are respectively divided into two groups according to parity of a port number. The distribution information read-write interfaces 3 whose port number is an odd number is grouped to form a group, the distribution information read-write interfaces 3 whose port number is an even number is grouped to form a group, the distribution port indicators 4 whose port number is the odd number is grouped to form a group, and the distribution port indicators 4 whose port number is the even number is grouped to form a group. The reference control ends of the distribution information read-write interfaces 3 grouped into the same group are connected to form a machine disc read-write grouping enable line of the distribution information read-write interfaces 3 of this group. The reference management ends of the distribution port indicators 4 grouped into the same group are connected to form the machine disc instruction grouping enable line of the distribution port indicators 4 of this group. All machine disc read-write grouping enable lines and all machine disc instruction grouping enable lines of the passivated distribution interface disc 2 are connected to the machine disc enable control module 8 in the intelligent distribution management disc 1 .
Embodiment 1.4: Grouped Port Control+Grouped Machine Disc Enable (Evenly Divided into at Least Two Groups Respectively)
On a basis of the grouped port control manner in embodiment 1.1, the machine disc enable line is divided into a machine disc read-write grouping enable line and a machine disc instruction grouping enable line. The distribution information read-write interfaces 3 and distribution port indicators 4 in each passivated distribution interface disc 2 are evenly divided into at least two groups respectively in an ascending order or a descending order of the port numbers. The reference control ends of all the distribution information read-write interfaces 3 grouped into the same group are connected to form at least two machine disc read-write grouping enable lines of the passivated distribution interface discs 2 where the distribution information read-write interface 3 is located. The reference management ends of all the distribution port indicators 4 grouped into the same group are connected to form at least two machine disc instruction grouping enable lines of the passivated distribution interface discs 2 where the distribution port indicator 4 is located. All machine disc read-write grouping enable lines and all machine disc instruction grouping enable lines of the passivated distribution interface discs 2 are connected to the machine disc enable control module 8 in the intelligent distribution management disc 1 .
Embodiment 1.5: Grouped Port Control+Grouped Machine Disc Enable (2 Groups for an Odd Number and an Even Number)
Referring to FIG. 6 , on a basis of the grouped port control manner in embodiment 1.1, the machine disc enable lines are grouped into several machine disc grouping enable lines whose functions are basically the same. In each passivated distribution interface disc 2 , the distribution information read-write interface 3 whose port number is an odd number and the distribution port indicator 4 whose port number is the odd number match each other and are grouped into the same group. In each passivated distribution interface disc 2 , the distribution information read-write interface 3 whose port number is an even odd number and the distribution port indicator 4 whose port number is the even number match each other and are grouped into the same group. The reference control ends of all the distribution information read-write interfaces 3 grouped into the same group and the reference management ends of all the distribution port indicators 4 grouped into the same group are connected, to form one machine disc grouping enable line corresponding to this group. All machine disc grouping enable lines are connected to the machine disc enable control module 8 in the intelligent distribution management disc 1 .
Embodiment 1.6: Grouped Port Control+Grouped Machine Disc Enable (Evenly Divided into at Least Two Groups)
on a basis of the grouped port control manner in embodiment 1.1, the machine disc enable lines are grouped into several machine disc grouping enable lines (for a case where the machine disc enable lines are divided into two groups, refer to FIG. 6 ) whose functions are basically the same. All the distribution information read-write interfaces 3 and all the distribution port indicators 4 in each passivated distribution interface disc 2 are evenly divided into two groups are evenly divided into at least two groups respectively in an ascending order or a descending order of the port numbers. The distribution information read-write interfaces 3 and the distribution port indicators 4 with the same port number match each other and are grouped into the same group. The reference control ends of all the distribution information read-write interfaces 3 in each group and the reference management ends of all the distribution port indicators 4 in this group are connected, to form one machine disc grouping enable line corresponding to this group. All machine disc grouping enable lines are connected to the machine disc enable control module 8 in the intelligent distribution management disc 1 .
Embodiment 1.7: Group Number+Grouped Machine Disc Enable (2 Groups for an Odd Number and an Even Number)+Combined Port Control
Embodiment 1.8: Group Number+Grouped Machine Disc Enable (Evenly Divided into at Least 2 Groups)+Combined Port Control
Embodiment 1.7 performs port combination and control on a basis of Embodiment 1.5. Referring to FIG. 7 , Embodiment 1.8 performs the port combination and control on a basis of Embodiment 1.6. Specific connections of the port combination and control are as follows: the intelligent distribution management disc 1 includes a port information read-write module 6 , a port instruction control module 7 , and the machine disc enable control module 8 . The port information read-write module 6 draws forth several distribution information read-write lines, and numbers the several distribution information read-write lines in sequence. The port instruction control module 7 draws forth several port instruction control lines, and numbers the several port instruction control lines in sequence. All the numbered distribution information read-write lines and all the numbered port instruction control lines jointly form a port read-write bus. After all the distribution information read-write interfaces 3 and all the distribution port indicators 4 in the passivated distribution interface discs 2 are grouped according to a certain rule, in all the groups in each passivated distribution interface disc 2 , the ports are grouped and numbered in sequence again. Referring to FIG. 7 , the signal read-write ends of all the distribution information read-write interfaces 3 with the same group number among all the groups in all the passivated distribution interface discs 2 are jointly connected in parallel to the distribution information read-write line that the port information read-write module 6 draws forth and is corresponding to this group number. The display control ends of all the distribution port indicators 4 with the same group number among all the groups in all the passivated distribution interface discs 2 are jointly connected in parallel to the port instruction control line that the port instruction control module 7 draws forth and is corresponding to this group number.
Embodiment 1.9: Combined Port Control+Grouped Machine Disc Enable (Respectively Connected to Form a Group)
Referring to FIG. 8 , a basic circuit connection of a combined port control manner is as follows: an intelligent distribution management disc 1 includes a port information read-write instruction control module 10 and a machine disc enable control module 8 , where the port information read-write instruction control module 10 is a CPLD, an FPGA, a read-write bus of a microprocessor and a software management logic device thereof, or an output bus of the microprocessor and a software management device thereof. The port information read-write instruction control module 10 draws forth several port read-write control lines. In all the passivated distribution interface discs 2 , the signal read-write ends of the distribution information read-write interfaces 3 and the display control ends of the distribution port indicators 4 that have the same port number are jointly connected in parallel to the port read-write control line corresponding to the port number. All the port read-write control lines jointly form the port read-write bus. The port information read-write instruction control module 10 in the intelligent distribution management disc 1 performs port combination, control, and management on the distribution information read-write interfaces 3 and the distribution port indicators 4 in all the passivated distribution interface discs 2 .
On a basis of the combined port control manner, the basic circuit connection of the grouped machine disc enable manner is as follows: referring to FIG. 9 , the machine disc enable line is divided into a machine disc read-write enable line and a machine disc instruction enable line. The reference control ends of all the distribution information read-write interfaces 3 in passivated distribution interface discs 2 are connected as machine disc read-write enable lines of the passivated distribution interface discs 2 . The reference management ends of all the distribution port indicators 4 are connected as machine disc instruction enable lines of the passivated distribution interface discs 2 . The machine disc read-write enable lines and the machine disc instruction enable lines of all the passivated distribution interface discs 2 are connected to a machine disc enable control module 8 in the intelligent distribution management disc 1 .
Embodiment 1.10: Combined Port Control+Grouped Machine Disc Enable (2 Groups Respectively for an Odd Number and an Even Number)
On a basis of the combined port control manner in embodiment 1.9, the machine disc enable line is divided into a machine disc read-write grouping enable line and a machine disc instruction grouping enable line. The distribution information read-write interfaces 3 in each passivated distribution interface disc 2 are divided into two groups according to parity of a port number. The distribution information read-write interfaces 3 whose port number is an odd number is grouped to form a group, and the distribution information read-write interfaces 3 whose port number is an even number is grouped to form another group. The reference control ends of the distribution information read-write interfaces 3 grouped into the same group are connected as a machine disc read-write grouping enable line of the distribution information read-write interfaces 3 of this group. The distribution port indicators 4 in all the passivated distribution interface discs 2 are divided into two groups according to parity of a port number. The distribution port indicators 4 whose port number is the odd number is grouped to form a group, and the distribution information read-write interfaces 3 whose port number is the even number is grouped to form another group. The reference control ends of the distribution port indicators 4 grouped into the same group are connected as a machine disc instruction grouping enable line of the distribution port indicators 4 of this group. All machine disc read-write grouping enable lines and machine disc instruction grouping enable lines are connected to the machine disc enable control module 8 in the intelligent distribution management disc 1 .
Embodiment 1.11: Combined Port Control+Grouped Machine Disc Enable (Evenly Divided into at Least Two Groups Respectively)
On a basis of the combined port control manner in embodiment 1.9, the machine disc enable line is divided into a machine disc read-write grouping enable line and a machine disc instruction grouping enable line. The distribution information read-write interfaces 3 in each passivated distribution interface disc 2 are evenly divided into two or more groups in an ascending order or a descending order of the port numbers. The reference control ends of the distribution information read-write interfaces 3 grouped into the same group are connected as a machine disc read-write grouping enable line of the distribution information read-write interfaces 3 of this group. The distribution port indicators 4 in the passivated distribution interface discs 2 are evenly divided into two or more groups in the ascending order or the descending order of the port numbers. The reference management ends of the distribution port indicators 4 grouped into the same group are connected as the machine disc instruction grouping enable line of the distribution port indicators 4 of this group. All machine disc read-write grouping enable lines and machine disc instruction grouping enable lines are connected to the machine disc enable control module 8 in the intelligent distribution management disc 1 .
The functions and names of the functions for the enable lines of the machine disc in Embodiments 1.1 to 1.11 are not the same, where the enable lines are the machine disc enable line in Embodiment 1.1, the machine disc read-write enable line and the machine disc instruction enable line in Embodiment 1.2 and 1.9, the machine disc read-write grouping enable line and the machine disc instruction grouping enable line in Embodiments 1.3 to 1.4 and 1.10 to 1.11, and the machine disc grouping enable line in Embodiments 1.5 to 1.8. To simplify description and for easier understanding, in the following, same content is not repeated, and only different points are emphasized.
The following, through 11 specific embodiments that are Embodiments 2.1 to 2.11, respectively describes superimposition of a circuit where a disc in-position instruction signal line is connected to an enable line of a machine disc on the 11 basic circuits in Embodiments 1.1 to 1.11.
Embodiments 2.1 to 2.11 respectively add a disc in-position instruction function on a basis of Embodiments 1.1 to 1.11 in sequence, that is, add the disc in-position instruction signal line to connect to any enable line of the machine disc: a machine disc enable line, a machine disc read-write enable line, a machine disc instruction enable line, a machine disc grouping enable line, a machine disc read-write grouping enable line, and a machine disc instruction grouping enable line, and connection manners of the added lines are the same. Herein, the same connection manner of the added lines is emphasized: an intelligent distribution management disc 1 draws forth a disc in-position monitoring line; each passivated distribution interface disc 2 further includes a disc in-position instruction signal line; one end of the disc in-position instruction signal line is connected through an unidirectional level clamper 11 to any enable line (the machine disc enable line, machine disc read-write enable line, machine disc instruction enable line, machine disc grouping enable line, machine disc read-write grouping enable line, or machine disc instruction grouping enable line) of the passivated distribution interface discs 2 where the disc in-position instruction signal line, and the other end is connected to the disc in-position monitoring line that the intelligent distribution management disc 1 draws forth; the unidirectional level clamper 11 may be a diode or a unidirectional level clamper circuit. For an overall circuit connection in Embodiment 2.1, refer to FIG. 10 . For a circuit connection inside the passivated distribution interface discs 2 in Embodiment 2.1, refer to FIG. 11 . For the circuit connection inside the passivated distribution interface discs 2 in Embodiment 2.9, refer to FIG. 12 .
The following, through 11 specific embodiments that are Embodiments 3.1 to 3.11, respectively describes superimposition of a circuit where a disc in-position instruction signal line is connected to a ground cable of a machine disc on the 11 basic circuits in Embodiments 1.1 to 1.11, to perform independent disc in-position monitoring.
Embodiments 3.1 to 3.11 add a disc in-position instruction function on a basis of Embodiments 1.1 to 1.11 in sequence, that is, add the disc in-position instruction signal line to connect to the ground cable of the machine disc, and connection manners of the added lines are the same. Herein, the same connection manner of the added lines is emphasized: an intelligent distribution management disc 1 draws forth several disc in-position monitoring lines; a disc in-position instruction signal line is added to each passivated distribution interface disc 2 ; one end of the disc in-position instruction signal line is grounded, and the other end is respectively connected through a disc in-position monitoring line to a disc in-position monitoring end of the intelligent distribution management disc 1 , to perform the independent disc in-position monitoring. For an overall circuit connection in Embodiment 3.1, refer to FIG. 13 . For a circuit connection inside the passivated distribution interface discs 2 in Embodiment 3.1, refer to FIG. 14 . For the circuit connection inside the passivated distribution interface discs 2 in Embodiment 3.9, refer to FIG. 15 .
The following, through 11 specific embodiments that are Embodiments 4.1 to 4.11, respectively describes addition of a circuit of a disc type instruction function to the 11 basic circuits in Embodiments 1.1 to 1.11.
Embodiments 4.1 to 4.11 add the disc type instruction function on a basis of Embodiments 1.1 to 1.11 in sequence, and connection manners of the added lines are the same. Herein, the same connection manner of the added lines is emphasized: an interface disc type monitoring module 9 is added to an intelligent distribution management disc 1 ; the interface disc type monitoring module 9 is a CPLD, an FPGA, or an input bus of a microprocessor and a software management logic thereof having or not having a disc in-position instruction function. A disc type encoder 5 and several interface disc type instruction lines are added to each passivated distribution interface disc 2 . One ends of all the interface disc type instruction lines are connected through the disc type encoder 5 to any enable line (a machine disc enable line, a machine disc read-write enable line, a machine disc instruction enable line, a machine disc grouping enable line, a machine disc read-write grouping enable line, or a machine disc instruction grouping enable line) of the passivated distribution interface discs 2 where the interface disc type instruction line is located, and the other end is connected to the disc type instruction line corresponding to another passivated distribution interface disc 2 according to code position configuration for a code of the instruction line, to form a disc type monitoring line; the disc type monitoring line is connected to the interface disc type monitoring module 9 . For an overall circuit connection in Embodiment 4.1, refer to FIG. 16 . For a circuit connection inside the passivated distribution interface discs 2 in Embodiment 4.1, refer to FIG. 17 . For the circuit connection inside the passivated distribution interface discs 2 in Embodiment 4.9, refer to FIG. 18 .
The following, through 11 specific embodiments that are Embodiments 5.1 to 5.11, respectively describes addition of a circuit of a disc in-position instruction function and a disc type instruction function to the 11 basic circuits in Embodiments 1.1 to 1.11.
Embodiments 5.1 to 5.11 add the disc in-position instruction function and the disc type instruction function on a basis of Embodiments 1.1 to 1.11 in sequence, and connection manners of added lines are the same. Herein, the same connection manner of the added lines is emphasized: an intelligent distribution management disc 1 draws forth several disc in-position monitoring lines; a disc in-position instruction signal line is further added to each passivated distribution interface disc 2 ; one end of the disc in-position instruction signal line is grounded, and the other end is respectively connected through a disc in-position monitoring line that the intelligent distribution management disc 1 draws forth to a disc in-position monitoring end of the intelligent distribution management disc 1 , to perform the independent disc in-position monitoring. An interface disc type monitoring module 9 is further added to the intelligent distribution management disc 1 . The interface disc type monitoring module 9 is a CPLD, an FPGA, or an input bus of a microprocessor and a software management logic thereof not having a disc in-position instruction function. A disc type encoder 5 and several interface disc type instruction lines are further added to each passivated distribution interface disc 2 . One ends of all the interface disc type instruction lines are connected through the disc type encoder 5 to any enable line (a machine disc enable line, a machine disc read-write enable line, a machine disc instruction enable line, a machine disc grouping enable line, a machine disc read-write grouping enable line, or a machine disc instruction grouping enable line) of the passivated distribution interface discs 2 where the interface disc type instruction line is located, and the other end is connected to the disc type instruction line corresponding to another passivated distribution interface disc 2 according to code position configuration for a code of the instruction line, to form a disc type monitoring line; the disc type monitoring line is connected to the interface disc type monitoring module 9 . For an overall circuit connection in Embodiment 5.1, refer to FIG. 19 . For a circuit connection inside the passivated distribution interface discs 2 in Embodiment 5.9, refer to FIG. 20 .
The foregoing 55 embodiments are only examples for describing protection content of the present invention, and do not limit a protection scope of the present invention. Various changes and variations performed on specific grouping manners by a person skilled in the art are included in the protection scope of the present invention. Content not described in detail in this specification belongs to the prior art that is widely known by the person skilled in the art. | Disclosed is a circuit for realizing passivation of an intelligent optical distribution interface disc in a machine disc enable manner, which relates to the field of optical communications. In the present invention, a distribution port is separated from distribution management, all management circuits on a distribution interface disc are moved out, and all control and management functions are achieved on a distribution management disc, to enable passivation of a distribution interface disc circuit, i.e. any active electronic devices such as integrated circuits, triodes, etc. which are easily damaged by static electricity and affected by fouling are not placed on the distribution interface disc any longer, and power lines are not introduced in the distribution interface disc. Using the present invention, no matter whether in a fusion-distribution integration or fusion-distribution separation design, during onsite construction, a distribution disc has both strong anti-static capability and fouling-resistant capability. When the fusion-distribution integration design is used, the device cost can be reduced, the device production process can be reduced, and the device performance and the distribution density can be increased. When the fusion-distribution separation design is used, even an optical fiber fusion splice point on the distribution disc generates failure, over-high requirements may not be put forward for maintenance and construction. | 6 |
FIELD OF THE INVENTION
[0001] This invention relates generally to metallurgical bonding and more particularly to a method for bonding a porous metal layer, or mesh, e.g., titanium, to a metal substrate, e.g., titanium.
BACKGROUND
[0002] In certain applications, it is desirable to affix a porous metal layer to a metal substrate. For example, certain medical devices employ a biocompatible metal substrate and it is desired to attach a biocompatible metal mesh to the substrate to promote bone and/or tissue ingrowth. International Application PCT/US2004/011079 published 28 Oct. 2004 (incorporated herein by reference) describes one such structure which uses a porous layer attached to the periphery of a percutaneously projecting stud for promoting tissue ingrowth for anchoring the stud and creating an infection resistant barrier,
[0003] Although various techniques have been described for bonding a mesh to a substrate, they are generally not suited for applications which use a fragile open weave mesh (e.g., having a pore size on the order of 50 to 200 microns and a porosity between 60 and 95%) and/or a thin substrate wall which can be easily distorted by an applied force. For example, adhesive bonding can be used to affix a mesh to a substrate but the adhesive is typically difficult to control in a blind process and therefore can undesirably fill some of the mesh openings. Moreover, adhesive bonds may be insufficiently strong for some applications and can create biocompatibility and/or tissue reaction problems.
[0004] Metallurgical solutions such as laser welding and diffusion bonding generally avoid the limitations of adhesive bonding but introduce other limitations which restrict their use for affixing a fragile open weave mesh to a thin substrate wall. For example, direct laser welding (discussed in U.S. Pat. Nos. 6,049,054 and 5,773,789) is generally not suitable because the low density of the mesh prevents sufficient coalescence of the mesh wires to form an adequate bond. Laser welding with filler material can be used to achieve greater coalescence but the size of the resulting weldment can then obstruct open spaces in the mesh thus reducing the mesh efficacy to promote tissue ingrowth. This is especially true if many such weldments, or tacks, are required.
[0005] Diffusion bonding has also been discussed for bonding a mesh pad to a metal substrate. Typically, this involves first diffusion bonding the pad to an underlayer and then bonding the underlayer to the substrate at a lower temperature. The initial diffusion bonding step typically necessitates the use of a high contact pressure for a relatively long time interval. Such a high pressure exerted against a fragile open weave mesh pad can distort and compromise the openness of the mesh and additionally can potentially distort a thin substrate wall. Furthermore, the necessity of applying high pressure and high temperature to nonplanar components (i.e., mesh and substrate) presents a challenging production fixturing problem which can be costly and time consuming.
SUMMARY OF THE INVENTION
[0006] The present invention is directed to a method for metallurgically bonding a metal wire mesh to a metal substrate which method allows the use of a fragile open weave mesh (e.g., having a pore size on the order of 50 to 200 microns and a porosity between 60 and 95%) and/or a thin wall substrate. More particularly, the invention is directed to ametallurgical bonding process which avoids the necessity of applying a pressure sufficiently high to distort the mesh and/or substrate structures and avoids the use of bonding material which potentially could reduce the openness of the mesh.
[0007] A preferred bonding process in accordance with the invention will be described with reference to a medical device application which requires affixing an open weave wire mesh structure (e.g., titanium 150×150 mesh twill having a wire diameter of 0.0027″ and a width opening of 100 microns) to a thin housing wall, or substrate, (e.g., titanium having a wall thickness of 0.005″).
[0008] In accordance with the invention, a thin nickel based layer is placed between a titanium based substrate and a titanium based wire mesh. The mesh and substrate are lightly clamped in intimate contact against the nickel interlayer therebetween, e.g., by wire wrapping. The sandwich, or assembly, (i.e., substrate, interlayer, mesh) is then heated to a temperature, below the melting point of titanium and nickel but sufficient to form a eutectic titanium-nickel alloy (e.g., Ti 2 Ni). For example, in one preferred embodiment, the assembly is processed as follows:
A.) Place assembly in vacuum B.) Heat to 600° C. in 20 minutes. C.) Dwell at 600° C. for 10 minutes, D.) Heat to 1035° C. in 35 minutes, E.) Dwell at 1035° C. for 10 minutes. F.) Cool to 600° C. in 5 minutes. G.) Dwell at 600° C. for 5 minutes H.) Cool to Ambient Temperature under vacuum in 2 to 3 hours. I.) Release vacuum.
[0018] The foregoing procedure causes the nickel to diffuse into the titanium (mesh and/or substrate) to form a biocompatible alloy extending a short distance beneath the substrate surface. Wherever the nickel is in contact with both the mesh and the substrate, the alloy bonds the mesh wire and substrate together.
[0019] If a sufficiently thin layer of nickel is used, all the nickel will be completely absorbed in areas where it contacts the substrate or the mesh, thereby creating a minimal amount of fluid alloy. The nickel interlayer can be introduced either discretely in a sheet of nickel foil, or through conventional processes such as vapor deposition, electroless nickel or electroplated nickel. A 0.0001″ thickness of nickel is suitable to form a metallurgical bond for an exemplary mesh structure as specified above while avoiding excessive alloying with the substrate or filling the mesh openings. A greater nickel thickness, e.g., greater than 0.0002″ can result in excessive fluid alloy formation which can fill the mesh openings and diffuses into the substrate. The appropriate thickness of nickel for other configurations of mesh and substrate thickness can be readily experimentally determined,
BRIEF DESCRIPTION OF THE FIGURES
[0020] FIG. 1 is a perspective exterior view of an exemplary medical device which can be fabricated in accordance with the present invention;
[0021] FIG. 2 is an exterior plan view of the medical device of FIG. 1 ;
[0022] FIG. 3 is a sectional view taken substantially along the plane 3 - 3 of FIG. 2 ;
[0023] FIG. 4 is an exploded perspective view showing the multiple components of the medical device of FIGS. 1-3 ; and
[0024] FIG. 5 is a plot showing the diffusion of nickel into the titanium substrate in accordance with the present invention.
DETAILED DESCRIPTION
[0025] The present invention is directed to a method for bonding a porous metal layer to a metal substrate and to the bonded structure resulting therefrom. Although the invention can be advantageously employed in a variety of applications, it will be described herein primarily with reference to an implantable medical device carrying wire mesh adapted to promote tissue ingrowth.
[0026] The preferred medical device 10 (as depicted in FIGS. 1-3 ) is comprised of a housing 12 formed of a biocompatible material, typically titanium. The housing generally comprises a hollow cylindrical stud 14 having an outwardly extending lateral flange 16 . The stud 14 is comprised of a thin titanium wall 18 having an outer peripheral surface 20 and an inner peripheral surface 22 . The inner peripheral surface 22 surrounds an interior volume 24 intended to accommodate functional components, e.g., a transducer and drive electronics (not shown). The flange 16 defines a lateral shoulder surface 26 which is contiguous with the stud outer peripheral surface 20 .
[0027] As is discussed in the aforementioned International Application PCT/US2004/011079, it is desirable to affix a porous layer to the stud outer peripheral surface 20 and/or the flange shoulder surface 26 for promoting tissue ingrowth to create an infection resistant barrier and provide effective device anchoring. Although various porous structures can be used, the preferred porous layer which will be assumed herein comprises titanium wire mesh 27 having a pore size on the order of 50 to 200 microns and a porosity of 60 to 95%.
[0028] FIG. 3 depicts a stud wire mesh structure 28 formed of folded mesh layers mounted around the stud outer peripheral surface 20 and a second shoulder mesh structure 29 mounted on the shoulder surface 26 and extending around the peripheral surface 20 . The mesh structure 29 is comprised of multiple mesh layers 30 , 31 supported on a core plate 32 apertured to accommodate the stud 14 .
[0029] FIG. 4 is an exploded view of the medical device of FIGS. 1-3 and is useful to demonstrate the preferred method in accordance with the invention for bonding wire mesh structures to the surface of housing 12 . In accordance with the invention, a thin layer of nickel based material 48 , e.g., nickel foil, is placed on the shoulder surface 26 surrounding the stud 14 . Then, the shoulder mesh structure 29 (comprised of mesh layers 30 , 31 mounted on plate 32 ) is placed around the stud 14 and on the nickel layer 48 . Thereafter, a thin layer of nickel based material 50 , e.g., nickel foil, is placed around the stud peripheral surface 20 . Subsequently, the stud mesh structure 28 is placed around the nickel layer 50 . Light pressure is then applied around the mesh structure 28 (e.g., by wire wraps 54 ) to assure that the nickel interlayer 50 intimately contacts both the titanium substrate (i.e., stud peripheral surface 20 ) and the titanium wires of the mesh structure 28 . The pressure supplied by wire wraps 54 should be sufficiently light to avoid distorting the mesh structure 28 and/or thin wall substrate 18 . Light pressure is also applied (e.g., by wire wraps, not shown) to press mesh structure 29 against shoulder surface 26 to sandwich the nickel interlayer 48 therebetween. It is important for the nickel interlayer 48 to intimately contact both the titanium substrate, i.e., shoulder surface 26 , and the mesh structure 29 , but it is highly desirable to avoid distorting either the substrate or the mesh structure. Parenthetically, it is also pointed out that FIGS. 3 and 4 also shown a diaphragm or cap 60 which can be secured to the upper end of the housing wall 18 to seal the interior volume 24 .
[0030] The assembly so formed is then subjected to a heating-cooling procedure to form a biocompatible eutectic alloy of nickel and titanium for bonding the mesh to the substrate. A preferred processing of the assembly fabricated in FIG. 4 comprises the following steps:
A.) Place assembly in vacuum B.) Heat to 600° C. in 20 minutes. C.) Dwell at 600° C. for 10 minutes. D.) Heat to 1035° C. in 35 minutes. E.) Dwell at 1035° C. for 10 minutes. F.) Cool to 600° C. in 5 minutes. G.) Dwell at 600° C. for 5 minutes H.) Cool to Ambient Temperature under vacuum in 2 to 3 hours. I.) Release vacuum.
[0040] The foregoing procedure causes the nickel to diffuse into the titanium at the eutectic temperature of about 1035° C. to form a biocompatible titanium-nickel alloy (e.g., Ti 2 Ni). A bond is formed by the alloy wherever the nickel contacts both titanium substrate and the titanium mesh wires.
[0041] If a sufficiently thin nickel interlayer is used, all the nickel will be completely absorbed in areas where it contacts the substrate, the mesh wires, or both, thereby creating a minimal amount of fluid alloy. The nickel interlayer can be introduced either discretely in a sheet of nickel foil, or through conventional processes such as vapor deposition, electroless nickel or electroplated nickel. A 0.0001″ thickness of nickel forms a suitable metallurgical bond for an exemplary mesh structure as specified above while avoiding excessive alloying with the substrate or filling the mesh openings. A greater nickel thickness, e.g., greater than 0.0002″, can result in excessive fluid alloy formation which can fill the mesh openings and diffuses into the substrate. The appropriate thickness of nickel for various configurations of mesh and substrate thickness can be readily experimentally determined.
[0042] FIG. 5 is a plot depicting the exemplary penetration of nickel into the titanium substrate. At the substrate surface (i.e., zero depth), the eutectic alloy Ti 2 Ni can be readily discerned. The concentration of nickel diminishes with depth from about 33% at the substrate surface to about zero at a depth of 0.001 inches. In contrast, the concentration of titanium increases from approximately 66% at the substrate surface to about 100% at a depth of 0.001 inches.
[0043] The aforedescribed process is characterized by at least the following attributes. First, the process requires pressure only sufficient to maintain contact between the mesh, nickel interlayer and the substrate. Such light clamping is much simpler to create and maintain, e.g., using wire wrapping, at high temperature than the heavier clamping typically necessary for diffusion bonding. Second, neither the substrate nor the mesh is subjected to deforming pressures, which would be especially problematic for hollow substrates or open-weave meshes subject to elevated temperatures. Third, The entire assembly is subject to a minimal amount of time at high temperature. Fourth, the process requires only a very small amount of nickel to rapidly alloy with the titanium mesh and the substrate at the eutectic temperature indicated (i.e., about 1035° C.). Fifth, the bonding is continuous across the interface of the mesh and substrate, as in diffusion bonding or adhesive bonding, rather than being held at only a discrete number of tack points as in laser welding. Sixth, the interlying layer of nickel is completely absorbed in forming the biocompatible alloy of nickel and titanium thereby avoiding degradation of the mesh porosity. It should be understood that although these multiple attributes are particularly significant when bonding a fragile open weave, or low density, mesh structure to a thin wall substrate, due to the ease of fixturing and processing, this method also provides significant advantages over existing methods of attaching even dense mesh pads to solid implants such as are commonly used in orthopedics.
[0044] Although the foregoing describes a particular preferred method for forming a eutectic alloy to bond titanium based wires to a titanium based substrate, it should be understood that variations and modifications may readily occur to those skilled in the art which are nevertheless consistent with the spirit of the invention and within the intended scope of the appended claims. | A method for metallurigically bonding a metal wire mesh to a metal substrate which allows the use of a fragile open weave mesh and/or a thin wall substrate. A thin nickel based layer is placed between a titanium based substrate and a titanium based wire mesh. The mesh and substrate are lightly clamped in intimate contact against the nickel interlayer therebetween, e.g., by wire wrapping. The sandwich, or assembly, (i.e., substrate, interlayer, mesh) is then heated to a temperature, below the melting point of titanium and nickel but sufficient to form a eutectic titanium-nickel alloy (e.g. , Ti 2 Ni). | 0 |
BACKGROUND OF THE INVENTION
1. Field of the Invention
The present invention relates to a method of operating a (CT) computed tomography device, by means of which volume data with respect to a volume region of a test object can be recorded.
2. Description of the Prior Art
Normally, before the definition of a region with respect to which volume data are to be recorded, for example by means of a spiral scan, an X-ray shadow image (topogram) is recorded, using which the scanning area of the following spiral scan is defined graphically. The definition of a scanning area is carried out by means of graphical marking of a region, inter alia a rectangular region, in the X-ray shadow image, which includes the interesting region of the test object. The length of the rectangle defines the length of the spiral scan, the width of the rectangle defines the width of the field of view represented in the CT image.
When defining a number of spiral scans, the above procedure is applied repeatedly.
German OS 199 25 395, which claims earlier priority but is not a prior publication, discloses a method of operating a CT device, in which volume data obtained in the course of a volume scan is used to extract the data needed for the reconstruction of an X-ray shadow image.
U.S. Pat. No. 5,995,580 describes a method of reconstructing volume data pertaining to a volume region that is limited in the direction of the system axis of a CT device, in which the start and end surfaces of the volume region are curved.
SUMMARY OF THE INVENTION
An object of the present invention is to provide a method of the type initially cited which makes it easier for an operator to obtain the diagnostic information desired in each case.
The above object is achieved in accordance with the principles of the present invention in a method for operating a CT device wherein volume data pertaining to a volume region of a test subject are obtained, having the following steps:
(a) recording volume data pertaining to a volume region of a test object and creating and displaying an X-ray shadow image of the volume region from the volume data;
(b) inserting at least one marking into the X-ray shadow image for identifying a reconstruction region with respect to which image data are to be reconstructed from the volume data;
(c) reconstructing and displaying a slice of at least one of a start and an end of the reconstruction region from the volume data; and
(d) reconstructing image data pertaining to each reconstruction region.
It is therefore possible, within the volume data recorded during a spiral scan, for example, to mark one or more regions with respect to which a reconstruction of image data is then carried out. In this case, there is the possibility, beyond the monitoring of the position of the reconstruction regions provided on the basis of the X-ray shadow image, of performing monitoring on the basis of slices which illustrate the start and/or end of a reconstruction region, that is to say slices representing a layer of the test object containing a start or end, in order if required to be able to correct the position of the reconstruction regions.
The ordering of the items in method step a) need not necessarily be precisely as set forth above. Instead, the recording of the volume data can be carried out both before and after the creation and display of the X-ray shadow image.
In a preferred embodiment of the invention, at least one reconstruction region is assigned at least one reconstruction parameter, and the reconstruction of image data with respect to the reconstruction region is carried out by taking into account the reconstruction parameters assigned to it; according to one variant of the invention, the reconstruction parameters typical of the respective reconstruction region being the layer thickness on which the reconstruction is based—the so-called reconstructed layer thickness—and/or the convolution core to be used in the reconstruction. The assignment of further or different reconstruction parameters is possible within the scope of the invention.
The invention supports the clinical application of CT devices by means of easier operation and an optimized sequence, in particular in those applications for which it is necessary, for the diagnosis of an organ, for example, to reconstruct part sections of the organ with a different layer thickness than other part sections of the same organ, since this is carried out on the basis of volume data which has been obtained during a single spiral scan, since the marking of the reconstruction regions is carried out simultaneously in a single operation and in a single X-ray shadow image, and since, on the basis of the slices illustrating the start and/or end of a reconstruction region, additional monitoring of a plurality of correct position of the reconstruction regions is possible.
If a number of reconstruction regions are marked, these can at least partly overlap one another, according to a variant of the invention. This offers the advantage that regions of the test object that are contained in a plurality of reconstruction regions do not have to be scanned repeatedly and, in the process, be subjected to X radiation.
In a preferred embodiment of the invention, the volume data is recorded in the form of a spiral scan. However, there is also the possibility of obtaining the volume data in another way, for example by means of sequential scanning.
Modern multilayer CT devices, that is to say CT devices whose detector system has a plurality of rows of detector elements, are capable of scanning volumes with a high axial resolution, that is to say close collimation (low layer thickness of the layers of the test object scanned by means of the individual lines of the detector system) in a single spiral scan. This scanning results in volume data from which, for example, images of thin or thick layers can subsequently be reconstructed. It is therefore possible for the user to obtain various diagnostic information from volume data recorded during a single spiral scan with close collimation: thinner layers in order to be able to obtain information about high-contrast structures, for example bones, vessels filled with contrast media, bronchiae containing air or prepared intestine, and thicker layers, in order to be able to obtain information about low-contrast structures, for example soft tissue parts.
A typical example is a spiral scan of the skull with a collimation of 4*1 mm. For the base of the skull, the radiologist needs layer thicknesses of 3 mm or 4 mm thickness, for the cerebrum, layer thicknesses of 5 mm to 8 mm are normal. In the case of simultaneous CTA (CT angiography), the thinnest layers of 1 mm are required, for example for the display of the Circulus Willisis.
Similar requirements arise during the examination of other organs, such as lungs, with high-resolution images of 1 mm layer thickness and standard images of 5 mm layer thickness, or CTA of the abdomen or examination of the entire aorta with the various arterial exits.
If a number of spiral scans is carried out, such as in the case of a multiphase liver examination, then the procedure can be carried out in the manner described above with respect to each individual spiral scan.
DESCRIPTION OF THE DRAWINGS
FIG. 1 illustrates a CT device for conducting the inventive method in a partly perspective, partly block-diagram illustration.
FIG. 2 is a longitudinal section through the device of FIG. 1 .
FIGS. 3 through 5 respectively show displays at the operator interface of the CT device of FIGS. 1 and 2 , as occur during the execution of the inventive method.
DESCRIPTION OF THE PREFERRED EMBODIMENTS
In FIGS. 1 and 2 , a multilayer CT device of the third generation suitable for carrying out the method according to the invention is illustrated. Its measuring arrangement, designated overall by 1 , has an X-ray source, designated overall by 2 , with a collimator 3 ( FIG. 2 ) placed in front of it close to the source, and a detector system 5 constructed as a two-dimensional array of a number of rows and columns of detector elements—one of these is designated 4 in FIG. 1 having a collimator 6 ( FIG. 2 ) arranged in front of the system, close to the detector. The X-ray source 2 with the collimator 3 on the one hand, and the detector system 5 with the collimator 6 on the other hand are fitted in a manner which can be seen from FIG. 2 opposite each other on a rotary frame 7 in such a way that a pyramidal X-ray beam originating from the X-ray source during the operation of the CT device 2 , collimated by the adjustable collimator 3 and whose edge beams are designated by 8 strikes the detector system 5 . In the process, the collimator 6 is set to correspond to the cross section of the X-ray beam set by means of the collimator 3 , such that only that region of the detector system 5 is exposed which can be struck directly by the X-ray beam. In the operating state illustrated in FIGS. 1 and 2 , these are four rows of detector elements. The fact that there are further rows of detector elements covered by the collimator 6 is indicated dotted in FIG. 2 .
The rotary frame 7 can be set rotating about a system axis designated by Z by means of a drive device, not illustrated. The system axis Z runs parallel to the z-axis of a three-dimensional rectangular coordinate system illustrated in FIG. 1 .
The columns of the detector system 5 likewise run in the direction of the z-axis, while the rows, whose width b is measured in the direction of the z-axis and is 1 mm, for example, run transversely with respect to the system axis Z and the z-axis.
In order to be able to bring a test object, for example a patient, into the beam path of the X-ray beam, a mounting device 9 is provided, which can be displaced parallel to the system axis Z, that is to say in the direction of the z-axis.
In order to record volume data of a test object located on the mounting device 9 , for example a patient, the test object is scanned by a large number of projections from various projection directions being recorded while the measuring unit 1 is moved around the system axis Z. The data supplied by the detector system 5 therefore contains a large number of projections.
During the continuous rotation of the measuring unit 1 around the system axis Z, at the same time the mounting device 9 is displaced continuously relative to the measuring unit 1 in the direction of the system axis Z, there being synchronization between the rotational movement of the rotary frame 7 and the translational movement of the mounting device 9 with the effect that the ratio between translation and rotation speed is constant and this constant ratio is adjustable, by a value for the advance h of the mounting device 9 per revolution of the rotary frame 7 being selected which ensures complete scanning of the interesting volume of the test object. The focus F of the X-ray source 2 therefore moves, as viewed from the test object, on a helical spiral path, designated by S in FIG. 1 , around the system axis Z, for which reason the type of recording of volume data described is also designated spiral scanning or a spiral scan. The volume data supplied in the process by the detector elements of each row of the detector system 5 , which data is projections in each case associated with a specific row of the detector system 5 and a specific position with respect to the system axis Z, is read out in parallel, serialized in a sequencer 10 and transmitted to an image computer 11 .
Following preprocessing of the volume data in a preprocessing unit 13 of the image computer 11 , the resultant data stream passes to a memory 14 , in which the volume data corresponding to the data stream are stored.
The image computer 11 contains a reconstruction unit 15 which reconstructs image data from the volume data, for example in the form of slices of desired layers of the test object, in accordance with methods known to those skilled in the art. The image data reconstructed by the reconstruction unit 15 is stored in a memory 14 and can be displayed on a display unit 16 , for example a video monitor, connected to the image computer 11 .
The X-ray source 2 , for example an X-ray tube, is supplied with the necessary voltages and currents by a generator unit 17 . In order to be able to set these to the respectively necessary values, the generator unit 17 is assigned a control unit 18 with keyboard 19 and mouse 20 , which permits the necessary settings.
In addition, the other operation and control of the CT device is carried out by means of the control unit 18 and the keyboard 19 and also the mouse 20 , which is illustrated by the fact that the control unit 18 is connected to the image computer 11 .
In order to restrict the recording of volume data to the diagnostically necessary region, and therefore to save the test object from unnecessary X-radiation, before the volume data is recorded, an X-ray shadow image of the diagnostically relevant region of the test object is prepared. For this purpose, with the X-ray source activated but without rotation of the measuring unit 1 about the system axis Z, the mounting device 6 is displaced in the direction of the system axis 7 relative to the measuring unit 1 by that amount which is required to record the diagnostically relevant region of the test object. The output data from the detector system 5 which arise in the process are transmitted in serialized form to the image computer 11 , which uses the data, in accordance with known algorithms, to calculate an X-ray shadow image (topogram), display it on the display unit 16 and if desired store it in the memory 14 . The display of an X-ray shadow image designated RSB is illustrated in FIG. 3 , which shows the monitor of the display unit 16 .
As additionally can be seen from FIG. 3 , it is possible, by means of the mouse 20 , the associated cursor is designated 21 , to mark a rectangular region SB in the X-ray shadow image RSB, with respect to which region volume data permitting the reconstruction of image data is to be recorded.
As soon as an operator activates a corresponding icon designated SCAN and illustrated on the monitor, by using the cursor 21 and actuating the left key of the mouse 20 , the control unit uses the position and size of the marked region SB to calculate the start and end point of the displacement of the mounting device 9 in the direction of the system axis Z which is necessary to be able to record the volume data permitting the reconstruction of image data with respect to the marked region SB in the course of a spiral scan, and arranges for the appropriate spiral scan to be carried out.
By using the X-ray shadow image RSB obtained in the manner described previously, it is possible, in the way illustrated in FIG. 4 by means of the mouse 20 , the associated cursor is again designated 21 , for example to mark rectangular reconstruction regions, for example 22 , 23 , 24 and 25 , in the X-ray shadow image RSB within the region SB with respect to which volume data has been recorded in the course of the spiral scan, with respect to which regions the reconstruction of image data is to take place on the basis of the volume data recorded.
The individual reconstruction regions 22 to 25 can be allocated individual reconstruction parameters by an operator by actuating corresponding operating elements displayed on the monitor.
As an example, FIG. 4 illustrates, as reconstruction parameters, the convolution core to be used in the reconstruction of the respective reconstruction region, kernel 1 , kernel 2 , kernel 3 , and the reconstructed layer thickness d on which the reconstruction of the respective reconstruction region is based. The reconstructed layer thickness d is the half-value width of the layer sensitivity profile and therefore that layer thickness from which the data in a reconstructed slice contain substantially originates.
However, before the reconstruction of image data is carried out with respect to the marked reconstruction regions 22 to 25 , there is the possibility of checking the correct position of the reconstruction regions 22 to 25 , by a slice indicated only by its outlines in FIG. 5 and transmitted by TOMO, being reconstructed for the start and/or end of a reconstruction region 22 to 25 , as viewed in the z direction, and displayed in the manner illustrated in FIG. 5 instead of the X-ray shadow image RSB. Such a slice, designated a test slice below, therefore represents a layer of the test object which, for example in the case of the start of the reconstruction region 22 , contains its front end designated by a in FIG. 4 and, in the case of the end of the reconstruction region 22 , contains its end designated by e in FIG. 4 .
A return to the X-ray shadow image RSB and therefore the monitor display according to FIG. 4 is carried out by activating an icon designated RETURN by means of cursor 21 and mouse 20 .
The production of test slices is carried out by, firstly, by means of cursor 21 and mouse 20 , the icon TEST displayed on the monitor being activated and then the cursor 21 being moved to the start or the end of the respective reconstruction region of interest, the associated test slice being reconstructed and displayed in accordance with FIG. 5 in response to a mouse click.
In this way, with the aid of test slices, as required all or individual specially relevant reconstruction regions can be checked with regard to their correct start and/or end.
Should it be determined, on the basis of a test slice, that the start or the end of the associated reconstruction region was not chosen correctly, then there is the possibility of correcting the position and/or size of the marking corresponding to the respective reconstruction region and possibly checking again by using test slices which are to be produced anew and correspond to the changed conditions.
Once all the reconstruction regions have been chosen correctly, by means of cursor 21 and mouse 20 an icon designated REC and displayed on the monitor is activated, whereupon the image computer 11 uses the volume data recorded previously in the course of the spiral scan to reconstruct image data with respect to the reconstruction regions 22 to 25 in accordance with algorithms known to those skilled in the art, using as a basis the reconstruction parameters associated with the respective reconstruction region.
Reconstruction parameters are assigned to a reconstruction region 22 to 25 by the cursor 21 being moved onto the respective reconstruction region, for example the reconstruction region 23 , and this reconstruction region being set into an activated state by actuating the right key of the mouse 20 , whereupon, if a convolution core and a reconstructed layer thickness d have been chosen, these reconstruction parameters are assigned to the respective reconstruction region.
The reconstruction parameters are assigned to the respectively activated reconstruction region, as far as the convolution core is concerned, by the cursor 21 being moved onto the button 26 to 28 associated with the respectively desired convolution core kernel 1 to kernel 3 and said button being activated by clicking the left-hand key of the mouse 20 .
As far as the reconstructed layer thickness is concerned, this is set by displacing a slider 29 on a scale 30 to the desired value, it being possible for the slider 29 to be adjusted by the cursor 21 being moved onto the slider 29 and the latter being displaced by actuating the left-hand key on the mouse 20 .
As can be seen from FIG. 4 , the reconstruction parameters assigned to the reconstruction regions 22 to 25 are displayed in the X-ray shadow image RSB within the reconstruction regions 22 to 25 .
As can further be seen from FIG. 4 , reconstruction regions can be defined which are completely separated from one another, such as the reconstruction regions 22 and 24 . However, reconstruction regions can also overlap to some extent, as is the case in the reconstruction regions 23 and 25 . In addition, reconstruction regions can be defined which overlap completely, that is to say are nested in one another, as is the case in the reconstruction regions 24 and 25 .
In the case of the previously described operating mode of the device, the marking of the reconstruction regions is carried out on the basis of an X-ray shadow image obtained before the recording of the volume data.
For the case in which volume data with respect to a diagnostically relevant region is already present and, for example, is stored in the memory 14 , the procedure in a second operating mode can also be such that an X-ray shadow image permitting the marking of reconstruction regions is derived from the volume data in accordance with a method known per se. The X-ray shadow image determined from the volume data is then displayed, in order to be able to mark the desired reconstruction regions therein, to check the correct position of the reconstruction regions by using reconstructed slices with respect to the start and the end of the respective region, and to assign reconstruction parameters to the marked reconstruction regions, whereupon the appropriate image data is reconstructed on the basis of the volume data already available. With this procedure, in the course of a diagnosis made on the basis of a volume data set that is present with respect to different reconstruction regions with associated reconstruction parameters or already previously reconstructed reconstruction regions with changed reconstruction parameters, it is possible to reconstruct image data without renewed recording of volume data being required, with the associated radiation exposure of the test object.
It therefore becomes clear that the method according to the invention makes it possible to define various reconstruction regions with the respectively suitable reconstruction parameters, and check them with regard to their correct position, in a graphical manner in a simple, flexible and comprehensible manner in volume data which is or has been recorded by means of a spiral scan, for example. In the process, it is not necessary for a plurality of reconstruction regions to be marked as described previously. Instead, it is also possible to mark only a single reconstruction region.
The construction of the image computer 11 in the case of the above exemplary embodiment was described as though the preprocessing unit 12 and the reconstruction unit 13 were hardware components. This can be so in fact. As a rule, however, the aforementioned components are implemented by software modules which run on a universal computer which is provided with the necessary interfaces and which, differing from FIG. 1 , can also perform the function of the control unit 18 , which is then superfluous.
The CT device in the case of the exemplary embodiment described has a detector system 5 with rows whose width measured in the z direction is of equal size and, for example, is 1 mm. Differing from this, within the scope of the invention a detector system can also be provided whose rows are of different width. For example, two inner rows each of 1 mm width and, on both sides of the latter, in each case a row of 2 mm width can be provided.
In the case of the exemplary embodiments described, the relative movement between the measuring unit 1 and the mounting device 9 is in each case produced by the mounting device 9 being displaced. However, within the scope of the invention, there is also the possibility of leaving the mounting device 9 in a fixed location and displacing the measuring unit 1 instead. In addition, within the scope of the invention there is the possibility of producing the necessary relative movement by displacing both the measuring unit 1 and the mounting device 9 .
The exemplary embodiments described above are CT devices of the third generation, that is to say the X-ray source and the detector system are displaced jointly about the system axis during the production of images. However, the invention can also be used in connection with CT devices of the fourth generation, in which only the X-ray source is displaced about the system axis and interacts with a stationary detector ring, if the detector system is a two-dimensional array of detector elements.
The method according to the invention can also be used in CT devices of the fifth generation, that is to say CT devices in which the X radiation originates not only from one focus but from a plurality of foci of one or more X-ray sources displaced about the system axis, if the detector system has a two-dimensional array of detector elements.
The CT devices used in connection with the exemplary embodiments described above have a detector system with detector elements arranged in the manner of an orthogonal matrix. However, the invention can also be used in conjunction with CT devices whose detector system has detector elements arranged in a manner other than a two-dimensional array.
The exemplary embodiments described above relate to the medical application of the method according to the invention. However, the invention can also be applied outside medicine, for example in checking luggage or in material examination.
Although modifications and changes may be suggested by those skilled in the art, it is the invention of the inventor to embody within the patent warranted heron all changes and modifications as reasonably and properly come within the scope of his contribution to the art. | A method for operating a computed tomograph device is provided by which volume data pertaining to a volume area of a test object can be recorded. A marking for identifying a reconstruction area to be reconstructed is faded into an x-ray shadow image containing the volume area, wherein a split image of the beginning and/or end of the reconstruction area is reconstructed from the volume data in order to verify the position of the reconstruction area. | 0 |
CROSS REFERENCE TO RELATED APPLICATIONS
[0001] This application is based on and claims the benefit of priority from prior Japanese Patent Application No. 2007-104122, filed on Apr. 11, 2007, the entire contents of which are incorporated herein by reference.
BACKGROUND OF THE INVENTION
[0002] 1. Field of the Invention
[0003] The present invention relates to an absolute position length-measurement type encoder.
[0004] 2. Description of the Related Art
[0005] Incremental encoders and absolute encoders are known as devices for measuring travel distances of objects. The incremental encoders measure relative travel distances and absolute encoders allow for absolute position length-measurement.
[0006] In the case of photoelectric encoders, the incremental encoders have incremental tracks with incremental patterns including equally-spaced light and dark patterns. Based on these patterns, the incremental encoders count light and dark signals to detect relative travel distances. In addition, the incremental encoders may detect absolute travel distances by detecting origin detection patterns provided separately from the above-mentioned pattern with equally-spaced light and dark patterns, and then detecting relative travel distances from the origin. However, prior to the measurement, a scale must be moved to right and/or left directions in order to read origin detection patterns.
[0007] On the other hand, the absolute encoders have absolute tracks with absolute patterns representing pseudo-random codes such as M-sequence codes and detect absolute positions resulting from reading the absolute patterns for a corresponding object. Unlike the incremental encoders, the absolute encoders does not require any origin detection based on origin detection patterns and may start measurement from the very position when powered on, without moving the scale. However, the absolute encoders have a lower detection accuracy than the incremental encoders.
[0008] As such, an absolute position length-measurement type encoder is known where an incremental track with equally-spaced incremental patterns and an absolute track with absolute patterns representing pseudo-random codes are positioned in parallel on one scale, as disclosed in, e.g., JP H7-286861A. This encoder first detects the absolute position after powered on by reading absolute patterns on the absolute track. Then, the encoder detects a relative travel distance from that position by reading the incremental patterns on the incremental track. In this way, an absolute position length-measurement type encoder may be obtained that covers the shortcomings of each of the incremental and absolute encoders, while enjoying advantages of both encoders.
[0009] However, in encoders so configured, it is more difficult to form minute absolute patterns with respect to incremental patterns without positional errors, as incremental patterns have more minute light and dark pitches. In addition, as the entire length of a scale becomes longer, it is more difficult to maintain a relative phase relation between absolute patterns and incremental patterns throughout the scale.
[0010] Therefore, it is difficult to provide smaller absolute position length-measurement type encoders in which both absolute and incremental patterns are used.
SUMMARY OF THE INVENTION
[0011] An absolute position length-measurement type encoder according to the present invention comprises: a scale having an incremental track formed therein with incremental patterns including first light and dark patterns formed at equal intervals in first periods, an absolute track formed therein with absolute patterns representing absolute positions, and a reference position track formed therein with reference position patterns including second light and dark patterns formed at equal intervals in second periods longer than the first periods; a light source for emitting a measurement light to the scale; a photodetector for receiving the measurement light reflected at or transmitted through the scale; and a signal processing circuit for processing a received-light signal of the photodetector to detect an absolute position of the scale.
[0012] According to this encoder, the absolute patterns does not need to be formed precisely in relation to the incremental patterns with light and dark patterns formed therein at first periods, but rather it is sufficient to form the absolute patterns with a predetermined accuracy with respect to the reference position patterns that are formed at second periods larger than the first periods. Accordingly, the absolute patterns may accept larger position errors with respect to the incremental patterns, which may lead to more minute incremental patterns as well as improved accuracy encoders.
BRIEF DESCRIPTION OF THE DRAWINGS
[0013] FIG. 1 is a schematic diagram illustrating an entire configuration of an absolute position length-measurement type photoelectric encoder according to a first embodiment of the present invention:
[0014] FIG. 2 is a plan view illustrating a configuration of the scale 12 in FIG. 1 ;
[0015] FIG. 3 is a plan view illustrating a configuration of the photodiode array 14 in FIG. 1 ;
[0016] FIG. 4 illustrates operations of the absolute position length-measurement type photoelectric encoder according to the first embodiment;
[0017] FIG. 5 is a schematic diagram illustrating an entire configuration of an absolute position length-measurement type photoelectric encoder according to a second embodiment of the present invention;
[0018] FIG. 6 is a plan view illustrating a configuration of the scale 12 in FIG. 5 ;
[0019] FIG. 7 is a plan view illustrating a configuration of the scale 12 in FIG. 6 without hatching;
[0020] FIG. 8 is a plan view illustrating a configuration of the photodiode array 14 in FIG. 5 ;
[0021] FIG. 9 is a schematic diagram illustrating details of the configuration of the ABS/reference position integrated scale 34 in the scale 12 illustrated in FIG. 5 ;
[0022] FIG. 10 is a schematic diagram illustrating details of the configuration of the ABS/reference position integrated scale 34 in the scale 12 in FIG. 6 ;
[0023] FIG. 11 illustrates a configuration of the scale 12 of an absolute position length-measurement type photoelectric encoder according to a third embodiment of the present invention;
[0024] FIG. 12 illustrates a configuration of the scale 12 of an absolute position length-measurement type photoelectric encoder according to a fourth embodiment of the present invention;
[0025] FIG. 13 illustrates a configuration of the scale 12 of an absolute position length-measurement type photoelectric encoder according to a fifth embodiment of the present invention;
[0026] FIG. 14 illustrates a configuration of the scale 12 of an absolute position length-measurement type photoelectric encoder according to a sixth embodiment of the present invention;
[0027] FIG. 15 illustrates a configuration of the scale 12 of an absolute position length-measurement type photoelectric encoder according to a seventh embodiment of the present invention;
[0028] FIG. 16 illustrates a configuration of the scale 12 of an absolute position length-measurement type photoelectric encoder according to a eighth embodiment of the present invention; and
[0029] FIG. 17 illustrates a variation of the embodiments.
DETAILED DESCRIPTION OF THE EMBODIMENTS
[0030] Embodiments of the present invention will now be described in detail below with reference to the accompanying drawings.
First Embodiment
[0031] FIG. 1 is a schematic diagram illustrating an entire configuration of an absolute position length-measurement type photoelectric encoder according to a first embodiment of the present invention. The absolute position length-measurement type photoelectric encoder according to this embodiment comprises a light-emitting element 11 , a scale 12 , a lens 13 , a photodiode array 14 , and a signal processing circuit 20 .
[0032] The light-emitting element 11 is a light source, such as a laser diode, that emits a coherent light. As illustrated in FIG. 2 , the scale 12 is configured to form the following tracks on a transparent glass substrate: an incremental track 301 with incremental patterns 31 formed at an arrangement pitch Pi (e.g., 40 μm) that include equally-spaced light and dark regions, and an absolute track 302 with general absolute patterns 32 that represent absolute positions in pseudo-random patterns (in this case, M-sequence codes).
[0033] In addition to this, the scale 12 further comprises a reference position track 303 with reference position patterns 33 , each of which has a width of Wr in a direction of length-measurement. The reference position patterns 33 have a predetermined phase relation to the absolute patterns 32 and are formed at an arrangement pitch Pr (>Pi) with equally-spaced light and dark regions. That is, the absolute patterns 32 represent absolute positions of the equally-spaced patterns in the reference position patterns 33 . The arrangement pitch Pi of the incremental patterns 31 is set to be smaller than the arrangement pitch Pr of the reference position patterns 33 , e.g., by a factor of an integer. In this embodiment, for illustration, it is assumed that Pi=4Pr. For example, if Pi=40 μm, then Pr is set to 160 μm.
[0034] The incremental patterns 31 and the reference position patterns 33 may easily be formed in an accurate fashion throughout the whole length of the encoder, since both are formed at equally-spaced arrangement pitches (Pi, Pr) throughout the length, respectively. In contrast, the absolute patterns 32 are difficult to be formed in an accurate fashion throughout the length of the encoder, since none of the regions in the absolute patterns 32 is the same throughout the length.
[0035] In this case, It is assumed here that, as in the prior art, an encoder has only incremental patterns 31 and absolute patterns 32 , without any reference position pattern 33 . According to such the encoder, for example, provided that the arrangement pitch of the incremental patterns 31 is 40 μm, then the absolute patterns 32 must have an accuracy less than one-half of the arrangement pitch, i.e., less than ±20 μm, throughout the length of the scale 12 .
[0036] As in this embodiment, if the reference position patterns 33 are formed at an arrangement pitch Pr larger than the arrangement pitch Pi of the incremental patterns 31 , such a position accuracy is sufficient for the absolute patterns 32 that is set to the same level as the arrangement pitch Pr of the reference position patterns 33 . In this way, the absolute patterns 32 may accept larger position errors. For example, if the arrangement pitch Pr of the reference position patterns 33 is four times larger than Pi, i.e., 160 μm, then the absolute patterns 32 may accept position errors up to ±80 μm throughout the length of the scale 12 . This means that the arrangement pitch Pi of the incremental patterns 31 can be determined regardless of the accuracy of the absolute patterns 32 . For example, the arrangement pitch Pi may be smaller than the positional accuracy of the absolute pattern 32 . Therefore, this embodiment may provide a more minute pitch of the incremental patterns 31 , which would provide improved accuracy in the encoder.
[0037] The light-emitting element 11 emits the scale 12 . Then, the irradiated light transmitted through the scale 12 is projected through the lens 13 onto the photodiode array 14 .
[0038] As illustrated in FIG. 3 , the photodiode array 14 comprises an INC photodiode array 41 , an ABS photodiode array 42 , and a reference position photodiode array 43 , corresponding to the incremental track 301 , the absolute track 302 , and the reference position track 303 , respectively. Each of the photodiode arrays 41 to 43 is configured to arrange photodiodes therein at a respective arrangement pitch corresponding to each of the corresponding patterns 31 to 33 .
[0039] The INC photodiode array 41 has four sets of photodiode arrays, each with a phase difference of 90°, respectively, and detects light and dark signals based on the incremental patterns 31 to output a quadrature sine wave signal with a phase difference of 90°. The ABS photodiode array 42 outputs signals resulting from sweeping light and dark signals based on the absolute patterns in a direction of length-measurement. In addition, a dimension WPDR (WPDR>Pr+Wr) in a direction of length-measurement is set for the reference position photodiode array 43 such that at least one or more reference position patterns 33 can be detected. The reference position photodiode array 43 outputs signals resulting from sweeping light and dark signals based on the reference position patterns 33 in the direction of length-measurement.
[0040] Now returning to FIG. 1 , further description will be given below. By way of an example, a signal processing device 20 comprises a noise filter/amplifier circuit 21 , an A/D converter 22 , a relative position detection circuit 23 , a noise filter/amplifier circuit 24 , an A/D converter 25 , an absolute position detection circuit 26 , a noise filter/amplifier circuit 27 , an A/D converter 28 , a reference position detection circuit 29 , and an absolute position composition circuit 30 .
[0041] The noise filter/amplifier circuit 21 removes noises in an analog output signal (a quadrature signal with a phase difference of 90°) provided by the INC photodiode array 41 . Then, the noise filter/amplifier circuit 21 amplifies and outputs the analog output signal. The A/D converter 22 converts the analog output signal output from the noise filter/amplifier circuit 21 to a digital signal. Through an arc-tangent calculation on the amplitude of the resulting digital signal (with a phase difference of 90°), the relative position detection circuit 23 outputs a relative position signal D 2 that indicates a relative travel distance and a travel direction of the scale 12 .
[0042] The noise filter/amplifier circuit 24 removes noises in an analog output signal (absolute position signal) provided by the ABS photodiode array 42 . Then, the noise filter/amplifier circuit 24 amplifies and outputs the analog output signal. The A/D converter 25 converts the analog output signal output from the noise filter/amplifier circuit 24 to a digital signal. In this case, the converted digital signal includes data of M-sequence codes represented by the absolute patterns 32 .
[0043] The absolute position detection circuit 26 has a table (not illustrated) that indicates a relationship between the M-sequence codes and absolute positions represented by the M-sequence. The absolute position detection circuit 26 refers to the table to output an absolute position signal D 1 that indicates an absolute position of the scale 12 .
[0044] The noise filter/amplifier circuit 27 removes noises in an analog output signal provided by the reference position photodiode array 43 . Then, the noise filter/amplifier circuit 27 amplifies and outputs the analog output signal. The A/D converter 28 converts the analog signal output from the noise filter/amplifier circuit 27 to a digital signal. Then, the reference position detection circuit 29 outputs a reference position signal D 3 that indicates reference positions of the reference position patterns included in the digital signal.
[0045] Based on the absolute position signal D 1 , relative position signal D 2 , and reference position signal D 3 , the absolute position composition circuit 30 calculates minute absolute positions of the scale 12 . Referring to FIG. 4 , operations of the absolute position composition circuit 30 will be described below. The absolute position signal D 1 has information for absolute positions of the scale 12 . Since the absolute patterns 32 are formed with a predetermined accuracy with respect to the reference position patterns 33 , it is possible to determine which one of periods Pr the scale 12 is located in for the reference position patterns 33 by obtaining absolute positions from the absolute position signal D 1 (( 1 ) of FIG. 4 ).
[0046] After the one of the periods Pr is determined for the reference position patterns 33 , the amount of signal for the reference position signal D 3 is detected. Then, it is possible to determine which period the scale 12 is located in for the incremental patterns 31 (( 2 ) of FIG. 4 ). Since the incremental patterns 31 and the reference position patterns 33 are formed with equally-spaced light and dark patterns, respectively, it is easy to maintain a position accuracy between these patterns at a high level even if the ratio of the arrangement pitches Pr and Pi is high. Therefore, by determining the period in which the scale 12 is located for the reference position patterns 33 and detecting the amount of signal for the reference position signal D 3 , it is possible to determine which period the scale 12 is located in for the incremental patterns 31 . Thereafter, absolute positions of the scale 12 may be calculated and output by counting light and dark regions of the relative position signal D 2 obtained from the incremental patterns 31 .
[0047] As can be seen from the above, according to this embodiment, an absolute position of the scale 12 is detected in relation to the reference position patterns 33 , based on the absolute position signals D 1 obtained from the absolute patterns 32 . Then, precision absolute position information of the scale 12 may be obtained, according to the reference position signal D 3 based on the reference position patterns 33 and the relative position signal D 2 based on the incremental patterns 31 . The absolute patterns 32 are not required to have a position accuracy comparative to the incremental patterns 31 formed in a minute manner, but rather it is sufficient to form the absolute patterns 32 with a predetermined position accuracy with respect to the reference position patterns 33 with a larger arrangement pitch. Therefore, this embodiment may provide a more minute pitch of the incremental patterns 31 , which would provide improved accuracy in the encoder.
Second Embodiment
[0048] Referring now to FIGS. 5 through 10 , an absolute position length-measurement type photoelectric encoder according to a second embodiment of the present invention will be described below. In FIGS. 5 through 10 , the same reference numerals represent the same components as the first embodiment and detail description thereof will be omitted herein.
[0049] FIG. 5 is a schematic diagram illustrating an entire configuration of the second embodiment, and FIG. 6 illustrates a plan configuration of the scale 12 . This embodiment differs from the first embodiment in that, as illustrated in FIG. 6 , it comprises, instead of the absolute patterns 32 and the reference position patterns 33 , an ABS/reference position integrated track 304 with ABS/reference position integrated patterns 34 , wherein these two types of patterns are integrated into one track. As illustrated in FIG. 6 , the ABS/reference position integrated track 304 is formed with the following two types of patterns arranged in one track: absolute patterns 32 ′ representing pseudo-random patterns and reference position patterns 33 ′ arranged in gaps between the absolute patterns 32 ′, at an arrangement pitch Pr larger than the arrangement pitch Pi of the incremental patterns 31 . Besides, the reference position patterns 33 ′ have hatching in FIG. 6 , which is for clarity of illustration as the absolute patterns 32 ′ and the reference position patterns 33 ′ can be easily distinguished from each other. In an actual scale, as illustrated in FIG. 7 , the absolute patterns 32 ′ and the reference position patterns 33 ′ are formed with the same material on the scale 12 , different only in their shapes. In this embodiment, as described above, since the scale 12 involves only two tracks therein, the scale 12 may be easily made smaller in comparison to the first embodiment where three tracks are involved therein.
[0050] In addition, corresponding to the scale 12 configured as above, the photodiode array 14 includes an INC photodiode array 41 and an ABS/reference position photodiode array 44 corresponding to each of the incremental track 301 and the ABS/reference position integrated pattern track 304 , as illustrated in FIG. 8 .
[0051] Further, as illustrated in FIG. 5 , the signal processing circuit 20 of this embodiment has a configuration similar to the first embodiment for signal processing ( 21 to 23 ) based on the incremental patterns 31 . On the other hand, the signals based on the ABS/reference position integrated patterns 34 as mentioned above are different from the first embodiment in that they are input to a separation circuit 201 via the noise filter/amplifier circuit 24 and the A/D converter 25 . The separation circuit 201 has a function for separating a signal provided from the reference position patterns 33 ′ from another provided from the absolute patterns 32 ′ in the ABS/reference position integrated patterns 34 . Such separation between these signals may be achieved through a correlation calculation between a signal based on the patterns 34 and a designed value of the reference position patterns 33 ′. That is, as a result of the correlation calculation, those signals may be obtained that are based on the reference position patterns 33 ′. As a correlation calculation, both multiplication type and subtraction type may be employed. The separated signal provided from the reference position patterns 33 ′ is input to the reference position detection circuit 29 , which in turn outputs a reference position signal D 3 .
[0052] Alternatively, those signals may be obtained that are based on the absolute patterns 32 ′ as a result of calculation of a correlation between a signal based on the patterns 34 and a designed value of the absolute patterns 32 ′.
[0053] Referring now to FIGS. 9 and 10 , an exemplary configuration of the ABS/reference position integrated patterns 34 according to this embodiment will be described below. FIG. 9 illustrates a first configuration. In the first configuration, the absolute patterns 32 ′ and the reference position patterns 33 ′ illustrated in the upper part of FIG. 9 are integrated in one track, which results in a configuration as illustrated in the lower part of FIG. 9 . When these patterns are integrated, some of the absolute patterns 32 ′ and the reference position patterns 33 ′ overlap each other (in the regions indicated by arrow A). In the first configuration, the absolute patterns 32 ′ are omitted in the overlapping regions and each of the reference position patterns 33 ′ is formed at each of the positions (indicated by arrow A) instead. In this way, when the absolute patterns 32 ′ are omitted (erased) in the regions indicated by arrow A, absolute positions may be detected as if the absolute patterns 32 ′ were not omitted, as long as the designed values of the reference position patterns 33 ′ (including information for the position of each arrow A) are known to the absolute position detection circuit 26 .
[0054] FIG. 10 illustrates a second configuration. In this case, as illustrated in FIG. 10( a ), if there is a region where some of the absolute patterns 32 ′ and the reference position patterns 33 ′ overlap each other, as illustrated in FIG. 10( b ), the absolute patterns 32 ′ are reduced in size and formed to eliminate any overlapping regions, instead of omitting such overlapping regions.
Third Embodiment
[0055] FIG. 11 illustrates a configuration of an absolute position detection type encoder according to a third embodiment of the present invention. The entire configuration is substantially the same as the first embodiment ( FIG. 1 ) and illustration thereof is omitted here.
[0056] This embodiment is different from the first embodiment in that the two types of tracks, reference position tracks 303 A and 303 B, are provided on opposite sides of the incremental track 301 (correspondingly, two reference position photodiode arrays 43 are also provided in the photodiode array 14 , while not illustrated). According to this configuration, if the scale 12 is tilted (yawing), those errors due to the yawing may be compensated by averaging signals based on each of the two types of patterns, reference position patterns 33 A and 33 B.
Fourth Embodiment
[0057] FIG. 12 illustrates a configuration of an absolute position detection type encoder according to a fourth embodiment of the present invention. The entire configuration is substantially the same as the first embodiment ( FIG. 1 ) and illustration thereof is omitted hire.
[0058] This embodiment is different from the above-mentioned embodiments in that ABS/reference position integrated tracks 304 A and 304 B similar to the second embodiment are formed on opposite sides of the incremental track 301 . According to this configuration, if the scale 12 is tilted (yawing), those errors due to the yawing may be compensated by averaging signals based on each of the two types of patterns, ABS/reference position patterns 34 A and 34 B.
Fifth Embodiment
[0059] FIG. 13 illustrates a configuration of an absolute position detection type encoder according to a fifth embodiment of the present invention. The entire configuration is substantially the same as the first embodiment ( FIG. 1 ) and illustration thereof is omitted here.
[0060] The fifth embodiment relates to a modification of the first embodiment. Specifically, A piece of the reference position pattern 33 is not formed of a single pattern as shown in FIG. 1 but is formed of plural patterns S 1 -S 4 that are arranged in an unequal interval.
[0061] The plural reference position patterns 33 , each of which is formed of such the unequally-arranged patterns S 1 -S 4 , are arranged with a width Wr, respectively, and with a pitch Pr. Such the patterns S 1 -S 4 are disclosed in JP H07-318371A, for example, and used as a origin detection pattern therein. Also in this embodiment, the reference position pattern 33 with such the patterns S 1 -S 4 serves to allow larger position errors of the absolute pattern 32 as described above, and may also be used as a origin detection pattern.
Sixth Embodiment
[0062] FIG. 14 illustrates a configuration of an absolute position detection type encoder according to a sixth embodiment of the present invention. The entire configuration is substantially the same as the first embodiment ( FIG. 1 ) and illustration thereof is omitted here. The sixth embodiment is a modification of the second embodiment. Specifically, a piece of the reference position 33 ′ in the second embodiment is not formed of a single pattern as shown in FIG. 6 and FIG. 7 , but is formed of plural patterns S 1 -S 4 that are arranged in an unequal interval. The other configurations are the same as the second embodiment.
Seventh Embodiment
[0063] FIG. 15 illustrates a configuration of an absolute position detection type encoder according to a seventh embodiment of the present invention. The entire configuration is substantially the same as the first embodiment ( FIG. 1 ) and illustration thereof is omitted here.
[0064] The seventh embodiment is a modification of the third embodiment. Specifically, a piece of the reference position 33 A and 33 B in the third embodiment is not formed of a single pattern as shown in FIG. 11 , but is formed of plural patterns S 1 -S 4 that are arranged in an unequal interval. The other configurations are the same as the third embodiment.
Eighth Embodiment
[0065] FIG. 16 illustrates a configuration of an absolute position detection type encoder according to a eighth embodiment of the present invention. The entire configuration is substantially the same as the first embodiment ( FIG. 1 ) and illustration thereof is omitted here. The seventh embodiment is a modification of the fourth embodiment. Specifically, a piece of the reference position 33 ′ in the fourth embodiment is not formed of a single pattern as shown in FIG. 12 , but is formed of plural patterns S 1 -S 4 that are arranged in an unequal interval. The other configurations are the same as the fourth embodiment.
Other Embodiments
[0066] Although the embodiments of the present invention have been described as above, the present invention is not intended to be limited to the disclosed embodiments and various other changes and additions may be made thereto without departing from the scope of the invention. For example, although the above-mentioned embodiments have been described in the context of a transmissive type photoelectric encoder, as illustrated in FIG. 17 , the light-emitting element 11 may be positioned at the same end as the lens 13 and the photodiode array 14 as a reflective type optical system from the light-emitting element 11 . | An absolute position length-measurement type encoder includes a scale having an incremental track, an absolute track, and a reference position track. The incremental track has incremental patterns including first light and dark patterns formed at equal intervals in first periods. The absolute track has absolute patterns representing an absolute position. The reference position track has reference position patterns including second light and dark patterns formed at equal intervals in second periods longer than the first periods. A light source emits a measurement light to the scale. A photodetector receives the measurement light reflected at or transmitted through the scale. A signal processing circuit processes the received light signal of the photodetector to detect an absolute position of the scale. | 6 |
BACKGROUND OF THE INVENTION
Field of the Invention
The present invention relates to a micropump, and more particularly, to a micropump configured to include a planar electrode or a cylinder electrode installed so that a direct-current or alternating-current electric field is applied to a rectangular channel or a cylinder channel and to be capable of transporting an insulation fluid with low conductivity in the range of 10 −10 to 10 −12 S/m.
Description of the Related Art
In recent years, interest and development of microfluidic systems have increased internationally. Such microfluidic systems are systems using micro-electromechanical systems (MEMS) technologies and are very important systems applied to fields such as clinical diagnoses, bio-medicine studies such as DNA and peptide, chemical analyses for new medicine development, ink jet printing, small cooling systems, small fuel cell fields.
Micropump and microvalves are core components configured to enable a fluid to flow in such a microfluidic system and have fluid control functions of adjusting an amount of fluid and a rate of the fluid and blocking the flow.
Here, micropumps are devices, such as small mechanical devices, minute fluid dynamics devices, microrobots, and electromechanical devices, configured to transport a fluid in a variety of fields and are evaluated as very important technologies in the near future.
In the related art, since pump devices configured to realize mechanical pressure transduction mainly used to transmit a fluid have very large sizes, there are technical limitations in manufacturing the pump devices with very small sizes. Therefore, there is a problem that it is difficult to apply the pump devices to micropumps required to have very small sizes.
In order to overcome the foregoing problems, in the related art, technologies for transporting a fluid by electrohydraulic flow occurring at the time of application of an electric field to the fluid to transport the fluid with a simple structure without using many components have been used to manufacture micropumps.
As representative examples, there are an ion-drag pump and an electro-sensitive fluid micropump usable for an insulation fluid.
However, the ion-drag pump and the electro-sensitive fluid micropump of the related art have the following technical problems.
First, the technologies of the related art have the problems that a target fluid usable in a pump is specified and it is difficult to apply the technologies to a general-purpose insulation fluid with electric conductivity in the range of 10 −10 to 10 −12 S/m.
Second, in the technologies of the related art, a micropump is operated only by a direct-current (DC) electric field and a flow rate of an insulation fluid is adjusted only by a voltage.
SUMMARY OF THE INVENTION
Accordingly, the present invention has been made in an effort to solve the problems occurring in the related art, and an object of the present invention is to provide a micropump capable of transporting an insulation fluid with low conductivity in the range of 10 −10 to 10 −12 S/m.
In order to achieve the above object, according to one aspect of the present invention, there is provided a micropump configured to control flow of an insulation fluid include: a rectangular channel ( 370 ) configured to have a rectangular shape in which a movement passage of the insulation fluid; a planar electrode forming section ( 310 ) configured to be formed inside the rectangular channel and have a planar shape for applying an electric field; an inflow section ( 320 ) configured such that the insulation fluid flows in; and an outflow section ( 330 ) configured such that the insulation fluid flows out.
Since an insulation fluid with low conductivity in the range of 10 −10 to 10 −12 S/m is transported merely with a simple technical structure without using a complicated component, it is possible to obtain the advantage of cost saving and application to various minute dynamics devices.
BRIEF DESCRIPTION OF THE DRAWINGS
The above objects, and other features and advantages of the present invention will become more apparent after a reading of the following detailed description taken in conjunction with the drawings, in which:
FIG. 1 is a diagram for describing a first principle of a cylinder electrode type insulation fluid micropump according to a first embodiment of the present invention;
FIG. 2 is a perspective view illustrating a cylinder electrode-rectangular channel type micropump according to the first embodiment of the preset invention;
FIG. 3 is a diagram illustrating an inner electrode arrangement of the cylinder electrode-rectangular channel type micropump according to the first embodiment of the present invention;
FIG. 4 is a diagram for describing a second principle of a planar electrode type insulation fluid micropump according to second to fourth embodiments of the present invention;
FIG. 5 is a plan view illustrating a planar electrode-rectangular channel type micropump according to the second embodiment of the present invention;
FIG. 6 is a plan view illustrating an inner arrangement of the planar electrode-rectangular channel type micropump according to the second embodiment of the present invention;
FIG. 7 is a plan view illustrating arrangement of inner electrodes of the planar electrode-rectangular channel type micropump according to the second embodiment of the present invention;
FIG. 8 is a perspective view illustrating a planar electrode-cylinder channel type micropump according to a third embodiment of the present invention;
FIG. 9 is a perspective view illustrating arrangement of inner electrodes of the planar electrode-cylinder channel type micropump according to a third embodiment of the present invention;
FIG. 10 is a perspective view illustrating a planar electrode-cylinder type electrohydraulic motor according to a fourth embodiment of the present invention;
FIG. 11 is a perspective view illustrating arrangement of inner electrodes of the planar electrode-cylinder type electrohydraulic motor according to the fourth embodiment of the present invention; and
FIG. 12 is a perspective view illustrating an inner rotor of the planar electrode-cylinder type electrohydraulic motor according to the fourth embodiment of the present invention.
DETAILED DESCRIPTION OF PREFERRED EMBODIMENTS
Reference will now be made in greater detail to a preferred embodiment of the invention, an example of which is illustrated in the accompanying drawings. Wherever possible, the same reference numerals will be used throughout the drawings and the description to refer to the same or like parts.
Hereinafter, specific embodiments of the present invention will be described in detail with reference to the drawings.
FIG. 1 is a diagram for describing a first principle of a cylinder electrode type insulation fluid micropump according to a first embodiment of the present invention.
Referring to FIG. 1 , the cylinder electrode type insulation fluid micropump include a first cylinder electrode 110 , a second cylinder electrode 111 a , and a third cylinder electrode 111 b installed to form a triangle shape in a vertical direction perpendicular to rectangular channels 114 and 115 .
The first cylinder electrode 110 includes a (−) pole or a (+) pole. A direct-current (DC) or alternating-current (AC) voltage is applied to the first cylinder electrode 110 . A ground (GND) voltage is applied to the second cylinder electrode 111 a and the third cylinder electrode 111 b.
Hereinafter, an operation principle of the cylinder electrode type insulation fluid micropump according to the present invention will be described in brief.
When the insides of the rectangular channels 114 and 115 are filled with an insulation fluid and a direct-current (DC) or alternating-current (AC) voltage is subsequently applied to the first cylinder electrode 110 , irregular electrode fields 112 are formed between the first cylinder electrode 110 and the second cylinder electrode 111 a and between the first cylinder electrode 110 and the third cylinder electrode 111 b.
In the formed irregular electric fields 112 , a gradient of electric conductivity of the insulation fluid is formed due to the Onsager effect. The formed gradient of the electric conductivity forms free charges in the insulation fluid due to the Maxwell-Wagner polarization phenomenon.
The formed free charges transfer a momentum to the peripheral insulation fluid while moving due to the influence of an electric force, so that the insulation fluid moves in one direction along an illustrated path 113 . Thus, the cylinder electrode type insulation fluid micropump according to the present invention functions as a pump.
As the insulation fluid according to the present invention, a solution is used in which an ionic or non-ionic surfactant or an alcoholic additive is a little added to an organic or inorganic insulation fluid with very low electric conductivity in the range of 10 −10 to 10 −12 S/m. Preferably, an additive of 0.001 wt % to 10 wt % is contained. In an example of the present invention, a silicon oil, dodecane, or toluene is used as the insulation fluid. Sorbitane trioleate (Span 85) may be used as the ionic surfactant. Sodium di-2-ethylhexyl sulfosuccinate (AOT) may be used as the non-ionic surfactant. Tetrabutylammonium tetrabutylborate may be used an oil soluble salt and methanol may be used as the alcohol.
In the present invention, metal substances with a property which is not solved in the insulation fluid are used for all of the first cylinder electrode 110 , the second cylinder electrode 111 a , and the third cylinder electrode 111 b . An insulation substance such as glass, plastic, or rubber is used for the rectangular channels 114 and 115 . For example, iron, copper, tungsten, aluminum, gold, silver, or the like is used as the metal substance.
FIGS. 2 and 3 are a perspective view illustrating a cylinder electrode-rectangular channel type micropump according to the first embodiment of the preset invention and a diagram illustrating an inner electrode arrangement of the cylinder electrode-rectangular channel type micropump, respectively.
Referring to FIG. 2 , a cylinder electrode-rectangular channel type micropump 200 according to the present invention includes a channel upper plate 270 , a rectangular channel 250 including the channel upper plate and having a rectangular parallelepiped shape, an electrode forming section 210 , an inflow section 230 , and an outflow section 240 .
The electrode forming section 210 is configured to include a ground electrode connecting portion 211 , an external power supply connecting portion 212 , a first cylinder electrode upper joining portion 213 , a second cylinder electrode upper joining portion 214 , and a third cylinder electrode upper joining portion 215 .
The ground electrode connecting portion 211 has a structure in which the second cylinder electrode upper joining portion 214 and the third cylinder electrode upper joining portion 215 are connected to each other and the ground voltage (GND) may be applied thereto.
The external power supply connecting portion 212 has a structure which is connected to the first cylinder electrode upper joining portion 213 and a direct current (DC) or alternating current (AC) voltage supplied from an external power supply may be applied to first cylinder electrodes 216 connected to the first cylinder electrode upper joining portion 213 . Here, the direct current is preferably in the range of 10 V to 10,000 V and the alternating current is preferably in the range of 10 V rms to 10,000 V rms at 0.1 kHz to 10 kHz.
The first cylinder electrode upper joining portion 213 has a structure in which a plurality of first cylinder electrodes 216 a to 216 e having a cylinder shape are connected. Here, the cylinder electrodes 216 a to 216 e are distant at constant intervals and are preferably distant by 5 to 10 times a cylinder diameter. Likewise, the second cylinder electrode upper joining portion 214 and the third cylinder electrode upper joining portion 215 have structures in which a plurality of second cylinder electrodes 217 a to 217 e and a plurality of third cylinder electrodes 218 a to 218 e having a cylinder shape are connected at constant intervals, respectively.
The first cylinder electrode 216 a , the second cylinder electrode 217 a , and third cylinder electrode 218 a located at the first position are formed as one set to constitute a first electrode set S 1 with a triangle shape.
Likewise, the first cylinder electrode 216 b , the second cylinder electrode 217 b , and the third cylinder electrode 218 b located at the second position to the first cylinder electrode 216 e , the second cylinder electrode 217 e , and the third cylinder electrode 218 e located at the fifth position constitute a second electrode set S 2 to a fifth electrode set S 5 , respectively.
The plurality of electrode sets S 1 may be formed at constant intervals. As the number of electrode sets S 1 increases, a flow rate of the insulation fluid is higher. Therefore, the intensity of the pump increases.
In the case of the present invention, the flow rate of the insulation fluid may be adjusted not only by adjusting a voltage in a direct-current electric field but also by adjusting a voltage and an alternating-current frequency in a case of an alternating-current electric field.
In the case of the present invention, the five electrode sets S 1 to S 5 have been described, but the present invention is not limited thereto. Of course, various modifications may be made in consideration of the fact that the movement rate of the insulation substance is faster as the number of electrode sets increases.
FIG. 4 is a diagram for describing a second principle of a planar electrode type insulation fluid micropump according to second to fourth embodiments of the present invention.
Referring to FIG. 4 , the channels 124 and 125 include a first planar electrode 120 and a second planar electrode 121 on one side surface of the inside.
The channels 124 and 125 may use a rectangular shape or a cylinder shape.
The first planar electrode 120 includes a (−) pole or a (+) pole. A direct-current (DC) or alternating-current (AC) voltage is applied to the first planar electrode 120 . The second planar electrode 121 includes an electrode with a wide width planar shape. A ground (GND) voltage is applied to the second planar electrode 121 .
Hereinafter, an operation principle of the planar electrode type insulation fluid micropump according to the present invention will be described in brief.
When the insides of the channels 124 and 125 are filled with an insulation fluid and a direct-current (DC) or alternating-current (AC) voltage is subsequently applied to the first planar electrode 120 , an irregular electrode field 122 is formed between the first planar electrode 120 and the second planar electrode 121 .
In the formed irregular electric field 122 , a gradient of electric conductivity of the insulation fluid is formed due to the Onsager effect. The formed gradient of the electric conductivity forms free charges in the insulation fluid due to the Maxwell-Wagner polarization phenomenon.
The formed free charges transfer a momentum to the peripheral insulation fluid while moving due to the influence of an electric force, so that the insulation fluid moves in one direction along an illustrated path 123 . Thus, the planar electrode type insulation fluid micropump according to the present invention functions as a pump.
As the insulation fluid according to the present invention, a solution is used in which an ionic or non-ionic surfactant or an alcoholic additive is a little added to an organic or inorganic insulation fluid with very low electric conductivity in the range of 10 −10 to 10 −12 S/M. Preferably, an additive of 0.001 wt % to 10 wt % is contained.
In the present invention, metal substances with a property which is not solved in the insulation fluid are used for all of the first planar electrode 120 and the second planar electrode 121 . An insulation substance such as glass, plastic, or rubber is used for the channels 124 and 125 .
FIGS. 5, 6, 7 are a plan view illustrating a planar electrode-rectangular channel type micropump according to the second embodiment of the present invention, a plan view illustrating an inner arrangement of the planar electrode-rectangular channel type micropump, and a plan view illustrating arrangement of inner electrodes of the planar electrode-rectangular channel type micropump, respectively.
Referring to FIG. 5 , a planar electrode-rectangular channel type micropump 300 according to the present invention is configured to include an electrode forming section 310 , an inflow section 320 , an outflow section 330 , and a rectangular channel 370 including a channel bottom section 340 , a vertical division wall 350 , and an upper cover 360 .
In the electrode forming section 310 , the channel bottom section 340 is subjected to patterning with a metal substance. A channel in which the insulation fluid may move from the inflow section 320 to the outflow section 330 is formed by the vertical division wall 350 . The upper portion of the vertical division wall 350 is sealed by the upper cover 360 .
Hereinafter, the shape, disposition, and the like of the electrode forming section 310 will be described in detail with reference to FIG. 7 .
The electrode forming section 310 is configured to include a ground electrode connecting portion 311 , a second planar electrode upper joining portion 312 , an external power supply connecting portion 313 , and a first planar electrode upper joining portion 314 .
The ground electrode connecting portion 311 is connected to the second planar electrode upper joining portion 312 and has a structure in which a ground voltage (GND) may be applied to the plurality of second planar electrodes 312 a to 312 e connected via the second planar electrode upper joining portion 312 .
Likewise, the external power supply connecting portion 313 is connected to the first planar electrode upper joining portion 314 and has a structure in which a direct-current (DC) or alternating-current (AC) voltage supplied from an external power supply may be applied to a plurality of first planar electrodes 314 a to 314 e connected via the first planar electrode upper joining portion 314 .
The first planar electrodes 314 a to 314 e have the same planar shape, width, and length. The second planar electrodes 312 a to 312 e also have the same planar shape, width, and length. The first planar electrodes 314 a to 314 e preferably have a width of 10 μm to 10 mm, a length of 50 μm to 100 mm. The second planar electrodes 312 a to 312 e have the same length of the first planar electrodes 314 a to 314 e , but the width of the second planar electrodes is 2 to 5 times of the width of the first planar electrodes.
The first planar electrode 314 a and the second planar electrode 312 a located at the first position constitute a first electrode set S 1 . Likewise, the first and second planar electrodes located at the second to fifth positions constitute a second electrode set S 2 to a fifth electrode set S 5 , respectively.
In the case of the present invention, the five electrode sets have been described, but the present invention is not limited thereto. Of course, various modifications may be made in consideration of the fact that the movement rate of the insulation fluid is faster as the number of electrode sets increases.
FIGS. 8 and 9 are a perspective view illustrating a planar electrode-cylinder channel type micropump according to a third embodiment of the present invention and a perspective view illustrating arrangement of inner electrodes of the planar electrode-cylinder channel type micropump, respectively.
Referring to FIG. 8 , a planar electrode-cylinder channel type micropump 400 according to the present invention is configured to include an electrode forming section 410 , an inflow section 420 , an outflow section 430 , and a cylinder channel 440 .
The electrode forming section 410 includes a ground electrode connecting portion 411 , an external power supply connecting portion 412 , a first planar electrode 413 having a cylindrical narrow planar surface, and a second planar electrode 414 having a cylindrical large planar surface.
On the other hand, an operation principle and a basic configuration of the planar electrode-cylinder channel type micropump 400 according to the third embodiment are basically the same as those of the planar electrode-rectangular channel type micropump 300 according to the second embodiment. There are differences in that the shape of the planar electrode is modified to the cylindrical shape and the rectangular shape depending on whether the shape of the channel is cylindrical or rectangular.
Accordingly, the repeated description of the details of the forgoing second embodiment will be omitted.
FIGS. 10, 11, and 12 are a perspective view illustrating a planar electrode-cylinder type electrohydraulic motor according to a fourth embodiment of the present invention, a perspective view illustrating arrangement of inner electrodes of the planar electrode-cylinder type electrohydraulic motor, and a perspective view illustrating an inner rotor of the planar electrode-cylinder type electrohydraulic motor, respectively.
Referring to FIG. 10 , a planar electrode-cylinder type electrohydraulic motor 500 according to the present invention is configured to include a cylinder container 510 , an electrode forming section 520 , a rotor 530 , and an upper cover 540 .
The electrode forming section 520 is configured to include a ground electrode connecting portion 521 , and an external power connecting portion 523 and include first planar electrodes 524 with a narrow width and second planar electrodes 522 with a large width for which a plurality of planar electrodes are patterned in the vertical direction on the wall surface of the cylinder container 510 .
The electrode forming portion 520 of the fourth embodiment and the electrode forming portion 410 of the third embodiment are common in that the cylinder type channel has the planar electrode form, but differ in that the first and second planar electrodes of the electrode forming section are disposed in an intersection manner in a straight form in the vertical direction along the cylinder wall surface in the case of the fourth embodiment, but are arranged in an intersection manner in a circular form in the case of the third embodiment.
Due to this difference in the disposition of the electrodes, the insulation fluid is transported clockwise in the case of the fourth embodiment. In the case of the third embodiment, however, the insulation fluid is transported in a straight from in the direction from the inflow section 420 to the outflow section 430 .
The rotor 530 is located inside the cylinder container 510 moves rotor's wirings 532 and provides a momentum to the rotor's wirings using a force which is generated at the time of application of an external electric field to the electrode forming section 520 and by which the insulation fluid is transported clockwise along the wall surface of the cylinder container 510 . The rotor 530 dynamically works to the outside through a rotor shaft 531 connected to the dynamic body.
Accordingly, since a component configuration is simpler than the configuration of an electromagnetic motor of the related art, application to manufacturing of a small motor can be achieved.
Although the technical sprit of the present invention have been described for illustrative purposes with reference to the accompanying drawings, the preferred embodiments of the present invention are merely exemplified and do not limit the present invention. It should be apparent to those skilled in the art that various modifications, additions and substitutions are possible, without departing from the scope and the technical spirit of the present invention as disclosed in the accompanying claims. | A micropump configured to control flow of an insulation fluid includes: a rectangular channel 370 configured to have a rectangular shape in which a movement passage of the insulation fluid; a planar electrode forming section 310 configured to be formed inside the rectangular channel and have a planar shape for applying an electric field; an inflow section 320 configured such that the insulation fluid flows in; and an outflow section 330 configured such that the insulation fluid flows out. Since an insulation fluid with low conductivity in a range of 10 −10 to 10 −12 S/m is transported with a simple technical structure without using a complicated component, it is possible to obtain the advantage of cost saving and application to various minute dynamics devices. | 5 |
BACKGROUND
1. Field of the Invention
The present invention relates to a pneumatic structural element.
2. History of the Related Art
Beam-like pneumatic structural elements and also those having a surface formation have become increasingly known over the last few years. These are mostly attributed to EP 01 903 559 (D1). A further development of said invention is provided in WO 2005/007991 (D2). Here, the compression rod has been further developed into a pair of curved compression rods which can also absorb tensile forces and are therefore designated as tension/compression elements. These run along respectively one surface line of the cigar-shaped pneumatic hollow body. D2 is considered to be the nearest prior art.
The strong elevated bending rigidity of the tension/compression elements loaded with compressive forces is based on the fact that a compression rod used according to D2 can be considered as an elastically bedded rod over its entire length, wherein such a rod is bedded on virtual distributed elasticities each having the spring hardness k.
The spring hardness k is there defined by
k=π·p
where
k=virtual spring hardness [N/m 2 ]
p=pressure in hollow body [N/m 2 ]
with the result that the bending load F k is obtained as
F k =2 √{square root over (k·E·I)}[N]
where
E=modulus of elasticity [N/m 2 ]
I=areal moment of inertia [m 4 ]
SUMMARY OF THE INVENTION
The object of the present invention is to provide a pneumatic structural element having tension/compression elements and an elongated gas-tight hollow body which can be formed and expanded into both curved and/or surface structures, having a substantially increased bending load F k compared with the pneumatic supports and structural elements known from the prior art.
BRIEF DESCRIPTION OF THE DRAWINGS
A more complete understanding of the device of the present invention may be obtained by reference to the following detailed description, taken in conjunction with the accompanying drawings, wherein:
FIG. 1 shows a first exemplary embodiment of a pneumatic structural element according to the invention in plan view;
FIG. 2 shows the exemplary embodiment of FIG. 1 in longitudinal section BB;
FIG. 3 shows a cross-section AA through the exemplary embodiment of FIG. 1 with the acting forces;
FIG. 4 shows the cross-section AA with an exemplary embodiment of a tension/compression element;
FIG. 5A shows a cross-section through a first exemplary embodiment of a tension/compression element in detail;
FIG. 5B is a cross-sectional view of a tension/compression element according to an exemplary embodiment;
FIG. 5C is a cross-sectional view of a tension/compression element according to an exemplary embodiment;
FIG. 6 shows a second exemplary embodiment of a pneumatic structural element in side view;
FIGS. 7 a, b shows the region of one end of a pneumatic structural element according to FIG. 6 ;
FIG. 8 shows a cross-section through a roof element according to the invention;
FIG. 9 shows a roof element according to FIG. 8 in isometric projection; and
FIGS. 10 , 11 , 12 show an exemplary embodiment of the invention as elements of a domed roof.
DETAILED DESCRIPTION
Various embodiments of the present invention will now be described more fully with reference to the accompanying drawings. The invention may, however, be embodied in many different forms and should not be construed as limited to the embodiments set forth herein; rather, the embodiments are provided so that this disclosure will be thorough and complete, and fully convey the scope of the invention to those skilled in the art.
FIG. 1 shows the pneumatic structural element according to the invention in a first exemplary embodiment in plan view. It is formed from two elongated, for example, cigar-shaped gas-tight hollow bodies 1 comprising a casing 9 and respectively two end caps 5 . The casing 9 in each case consists of a textile-laminated plastic film or of flexible plastic-coated fabric. These hollow bodies 1 intersect one another, abstractly geometrically, in a sectional area 2 as can be seen from FIG. 2 , which forms a section BB through FIG. 1 .
When the two hollow bodies 1 are filled with compressed gas, they acquire the form shown in section AA of FIG. 4 , under the conditions described hereinafter. As a result of the pressure p in the interior of the hollow body 1 , a linear stress a is built up in its casings 9 , which is given by
σ= p·R
σ=linear stress [N/m]
p=pressure [N/m 2 ]
R=radius of the hollow body 1 [m]
A textile web 4 , for example, is inserted in the lines of intersection of the two hollow bodies 1 , in the sectional area 2 , to which the linear stresses a of the two hollow bodies 1 are transmitted in the line of intersection, as shown in FIG. 3 . FIG. 3 shows the vectorial addition of the linear stresses a to the linear force fin the web 4 :
{right arrow over ( f )}={right arrow over (σ)} 1 +{right arrow over (σ)} r
where
{right arrow over (f)}=linear force in the web 4
{right arrow over (σ)} 1 =linear stress in the left hollow body 1
{right arrow over (σ)} r =linear stress in the right hollow body 1
For the same pressure p and the same radius R, the absolute magnitude of {right arrow over (f)} is dependent on the angle of intersection of the two circles of intersection of the two hollow bodies 1 .
In order to absorb tensile and compressive forces of the pneumatic structural element which have thus built up, the web 4 is clamped into a tension/compression element 3 having the form shown in FIG. 2 . The tension/compression element 3 absorbs the part of this linear force determined by the vector addition, as shown above, and is thereby pre-tensioned in the direction given by the vector representation. By filling the hollow body 1 with compressed air, a pre-tensioning of the web 4 by the linear force {right arrow over (f)} is obtained as f=2σ sin φ. Since the radius along the structural element is not generally constant, the pre-tensioning of the web along the structural element varies. By a suitable choice of the casing circumference and web height, the pre-tensioning of the web can be optimised according to the use of the pneumatic structural element or even made constant. The pre-tensioning of the web 4 is then pR 0 , where 2R =diameter of the end caps 5 .
This pre-tensioning brings about a behaviour of the tension/compression element 3 similar to a pre-tensioned string which only responds with a change in length when the pre-tensioning force is exceeded. Only when this pre-tensioning force is exceeded is there a risk of the tension/compression element 3 being bent. As a result of the indicated type of elastic bedding of the tension/compression element 3 , the bending load P k is given by
P k ≈ 3 ( EF ) 2 / 9 · ( EI ) 1 / 3 L 2 / 9 · ( p · R 0 ) 4 / 9
where
P k =critical bending load
E=modulus of elasticity of the tension/compression element 3
F=cross-sectional area of the tension/compression element 3
I=areal moment of inertia of the tension/compression element 3 and
L=length of the tension/compression element 3 .
In the pneumatic structural element according to the invention, therefore, the compressed air is used for pre-tensioning the flexible web so that this can transmit tensile and compressive forces and optimally stabilise the compression member against bending. The pneumatic structural element thus becomes more stable and light and is better able to bear local loads.
The tension/compression element 3 is laterally stabilised by the linear stresses 6 in the casing 9 .
FIG. 4 shows a technical embodiment of the diagram according to FIG. 3 in the section AA according to FIG. 1 . The tension/compression element 3 in this case, for example, consists of two C profiles 8 which have been screwed together. The casing 9 of the hollow body 1 is, for example, pulled between the C profiles 8 without interruption and is secured externally on the tension/compression element 3 by means of a beading 10 . The web 4 is inserted between the external layers of the casing 9 and is clamped securely by the screw connection of the C profiles 8 .
FIG. 5A shows a section through the tension/compression element 3 thus executed in detail.
FIG. 5B is a cross-sectional view of a tension/compression element according to an exemplary embodiment. In an exemplary embodiment, each tension compression element 3 consists of a profile rod having three grooves for receiving beading 10 . Two grooves are disposed laterally and one groove is disposed centrally. The casing 9 is clamped by the lateral beading 10 and the web 4 is clamped by the centrally disposed beading 10 .
FIG. 5C is a cross-sectional view of a tension/compression element according to an exemplary embodiment. In a typical embodiment, each tension/compression element 3 consists of a profile rod having a suitable areal moment of inertia. Each profile rod is inserted in a pocket 11 running longitudinally to the tension/compression element 3 . The casing 9 of the hollow body 1 is connected to this pocket in a gas-tight manner. The web is likewise connected to the pocket 11 . The connections of the casing 9 and the web 4 to the pocket 11 are produced by welding or adhesive bonding or sewing with subsequent sealing. In various embodiments, the connection between the pocket 11 and the web 4 is made in a gas-tight manner. In various embodiments, means are provided for guiding the tension/compression elements 3 in a gas-tight manner out from the hollow bodies 1 . The nodes 14 are disposed outside the hollow body 1 .
FIG. 6 shows a side view of a second exemplary embodiment of a pneumatic structural element according to the present invention. Compared to that of FIGS. 1 and 2 , this is upwardly arched, its longitudinal axis, designated here with numeral 6 , therefore now lying closer to the lower tension/compression element 3 designated as 3 b than to the upper tension/compression element designated as 3 a . The forces are derived via two supports 7 which absorb both vertical compressive and also tensile forces.
The ratio of length to height of the pneumatic structural elements shown in FIG. 4 is about 15.
FIGS. 7 a, b show diagrams of one end of a pneumatic structural element according to the invention, for example, from FIG. 6 ; the end not shown is preferably executed mirror-symmetrically. At the ends of the tension/compression element 3 , the two tension/compression elements are brought together and there form a node 14 . This is produced by replacing the web 4 , for example, by a plate 13 which transmits the necessary forces from and to the tension/compression elements 3 . Depending on the tension/compression elements used however, such a solution can be differently configured for transmitting forces. These are accessible to the person skilled in the art without particular expense.
FIG. 7 a shows a side view of the node 14 and FIG. 7 b shows a cross-section.
FIG. 8 shows the front view of a roof element 16 composed of a plurality of structural elements according to FIG. 1 . In each case, these are assembled at a tension/compression element 3 located between the hollow bodies 1 . The spacing of the tension/compression elements 3 is in each case 2R 0 , the diameter of the end caps 5 . A roof element 16 according to FIGS. 7 a and 7 b can be placed on a suitable supporting structure. As long as the supporting surface is substantially flat, the type of support is non-critical: it is not necessary to place the roof element 16 on the tension/compression elements 3 ; it can also be placed on the hollow body 1 as long as there is no risk of injury. In order to erect a roof consisting of one or more roof elements 16 , such a roof element 16 is joined together, in an assembly hall for example, from tension/compression elements 3 , the webs 4 and the casings 9 of the hollow body 1 . Each hollow body 1 , with a gas-tight web 4 , has its own connection 18 for the compressed gas. These connections 18 are usually placed on a common compressed gas line 19 so that all the hollow bodies 1 have the same gas pressure.
After assembling these said individual parts, the entire roof element 16 can be transported to the building site, on a lorry for example, and placed under gas pressure there. The roof element that is now stabilised by the compressed gas is placed on the provided and prepared support by means of a crane and secured there.
Lateral terminations 17 are located at the lateral ends of a roof element 16 . These also consist of hollow bodies 1 as shown in FIG. 8 . Their maximum diameter substantially corresponds to the lateral spacing of respectively two tension/compression elements 3 . The form profile of the lateral terminations 17 can be seen from FIG. 8 .
For large roofs a plurality of identical roof elements 16 can be placed adjacent to one another and in each case secured to one another at the outermost tension/compression elements 3 .
FIGS. 10 , 11 and 12 show a third exemplary embodiment of a pneumatic structural element according to the invention. FIG. 10 shows a curved tension/compression element 30 which rests on two pivot bearings 29 on a pivot axis 20 and is pivotable about said axis. The curved tension/compression element 30 comprises an outer arc 21 and an inner arc 22 . These arcs 21 , 22 are connected by a number, for example five, of struts 23 which are parallel to one another and by a plurality of tension wires 24 and are thus pre-stabilised without pneumatic hollow bodies. Again, as in the exemplary embodiment of FIGS. 1 , 2 , a web 4 is inserted parallel to the family of tension wires 24 and is secured to the arcs 21 , 22 by means of a beaded connection.
FIG. 10 shows a dome-shaped roof 26 erected on curved pneumatic structural elements 25 . Similarly to the first exemplary embodiment according to FIGS. 1 and 2 , a number, for example eighteen, of hollow bodies 1 is produced and connected to the curved tension/compression elements 30 as shown. As executed for the roof element 16 , the roof 26 can be prefabricated in an assembly hall. On the building site, a node 27 must be secured or concreted in the ground. At their ends, the curved tension/compression elements 30 each have a connection, not shown, which allows the curved tension/compression elements 30 to be pivotally mounted about the axes 20 . Numerous solutions are known for this in construction engineering. After being transported to the building site, said connections are made at the node 27 .
The dome-shaped roof 26 is now erected by filling the individual curved structural elements 25 with compressed gas. Since all the connections 18 , as implemented in FIGS. 7 a and 7 b , are connected to a common compressed gas line 19 , the uppermost structural element 25 will initially assume the round shape, successively followed by those located thereunder. The roof 26 is divided into two halves, which seal the roof tightly when completely filled.
Alternatively, the termination can be made by two curved tension/compression elements 30 which can be closed together, instead of by hollow bodies 1 . For this purpose, a plurality of pneumatically or electrically actuated closure mechanisms (not shown) are distributed on said tension/compression elements 30 . Numerous solutions are known for this in mechanical engineering.
Although various embodiments have been illustrated in the accompanying Drawings and described in the foregoing Detailed Description, it will be understood that the invention is not limited to the embodiments disclosed, but is capable of numerous rearrangements, modifications, and substitutions without departing from the spirit and scope of the invention as set forth herein. | The pneumatic structural element comprises from one to a number of interconnected elements of the following construction: two hollow bodies made of textile material coated in a gas-type manner and each having two end caps are assembled such that they produce a common sectional area. The edging of this sectional area is formed by two curved tension/compression elements into which is clamped a gas-tight web made of a flexible material of high tensile strength. This web can be connected to the tension/compression elements in a gas-tight manner. By filling the two hollow bodies with compressed gas, a tensile stress σ pretensions said web. This pretensioning increases the bending rigidity of the tension/compression elements. If a plurality of such elements are combined to form a roof, every two adjacent hollow bodies thus form a sectional area with a tension/compression element and web. | 8 |
CROSS REFERENCE TO RELATED APPLICATIONS
This is a continuation application of U.S. patent application Ser. No. 09/911,934 filed on Jul. 23, 2001 now U.S. Pat. No. 6,597,176, entitled “Method And Apparatus For Making Measurements Of Patterns Of Magnetic Particles In Lateral Flow Membranes And Microfluidic Systems” which is a divisional patent application of U.S. patent application Ser. No. 09/451,660 filed on Nov. 30, 1999, now U.S. Pat. No. 6,437,563 entitled “Method and Apparatus for Making Measurements of Accumulations of Magnetic Particles”, which is a continuation-in-part patent application of U.S. patent application Ser. No. 08/975,569 filed on Nov. 21, 1997, now U.S. Pat. No. 6,046,585 entitled “Method and Apparatus for Making Quantitative Measurements of Localized Accumulations of Targets Particles Having Magnetic Particles Bound Thereto”.
BACKGROUND OF THE INVENTION
1. Field of the Invention
This invention relates generally to sensing the presence of magnetic particles, and more particularly to quantitatively measuring accumulations of such particles by means of AC magnetic excitation and inductive sensing of the amplitude of the resulting oscillations of the magnetic moments of the particles at the excitation frequency.
2. Discussion of Prior Art
Much attention has been given to techniques for determining the presence, and possibly the level of concentration, of minute particles in a larger mixture or solution in which the particles reside. It is desirable in certain circumstances to measure very low concentrations of certain organic compounds. In medicine, for example, it is very useful to determine the concentration of a given kind of molecule, usually in solution, which either exists naturally in physiological fluids (for example, blood or urine) or which has been introduced into the living system (for example, drugs or contaminants).
One broad approach used to detect the presence of a particular compound of interest, referred to as the analyte, is the immunoassay, in which detection of a given molecular species, referred to generally as the ligand, is accomplished through the use of a second molecular species, often called the antiligand, or the receptor, which specifically binds to the first compound of interest. The presence of the ligand of interest is detected by measuring, or inferring, either directly or indirectly, the extent of binding of ligand to antiligand.
A discussion of several detection and measurement methods appears in U.S. Pat. No. 4,537,861 (Elings et al.). That patent discloses several ways to accomplish homogenous immunoassays in a solution of a binding reaction between a ligand and an antiligand, which are typically an antigen and an antibody. Elings discloses creation of a spatial pattern formed by a spatial array of separate regions of antiligand material and ligand material dispersed to interact with the spatial array of separate regions of antiligand material for producing a binding reaction between the ligand and the antiligand in the spatial patterns and with the bound complexes labeled with a particular physical characteristic. After the labeled bound complexes have been accumulated in the spatial patterns, the equipment is scanned to provide the desired immunoassay. The scanner may be based on fluorescence, optical density, light scattering, color and reflectance, among others.
The labeled bound complexes are accumulated on specially prepared surface segments according to Elings, or within an optically transparent conduit or container by applying localized magnetic fields to the solution where the bound complexes incorporate magnetic carrier particles. The magnetic particles have a size range of 0.01 to 50 microns. Once the bound complexes are accumulated magnetically within the solution, the scanning techniques previously described are employed.
Magnetic particles made from magnetite and inert matrix material have long been used in the field of biochemistry. They range in size from a few nanometers up to a few microns in diameter and may contain from 15% to 100% magnetite. They are often described as superparamagnetic particles or, in the larger size range, as beads. The usual methodology is to coat the surface of the particles with some biologically active material that causes them to bond strongly with specific microscopic objects or particles of interest (e.g., proteins, viruses, cells, DNA fragments). The particles then become “handles” by which the objects can be moved or immobilized using a magnetic gradient, usually provided by a strong permanent magnet. Thus, the Elings patent is an example of tagging using magnetic particles. Specially constructed fixtures using rare-earth magnets and iron pole pieces are commercially available for this purpose.
Although these magnetic particles have only been used in practice for moving or immobilizing the bound objects, some experimental work has been done on using the particles as tags for detecting the presence of the bound object. This tagging is usually done by radioactive, fluorescent, or phosphorescent molecules which are bound to the objects of interest. A magnetic tag, if detectable in sufficiently small amounts, would be very attractive because the other tagging techniques all have various important weaknesses. For example, radioactive methods present health and disposal problems. The methods are also relatively slow. Fluorescent or phosphorescent techniques are limited in their quantitative accuracy and dynamic range because emitted photons may be absorbed by other materials in the sample. See Japanese Patent Publication 63-90765, published Apr. 21, 1988 (Fujiwara et al.).
Because the signal from a very tiny volume of magnetic particles is exceedingly small, it has been natural that researchers have tried building detectors based on Superconducting Quantum Interference Devices (“SQUID”s). SQUID amplifiers are well known to be the most sensitive detectors of magnetic fields in many situations. There are several substantial difficulties with this approach, however. Since the pickup loops of the SQUID must be maintained at cryogenic temperatures, the sample must be cooled to obtain a very close coupling to these loops. This procedure makes the measurements unacceptably tedious. The general complexity of SQUIDs and cryogenic components renders them generally unsuitable for use in an inexpensive desktop instrument. Even a design based on so-called “high Tc” superconductors would not completely overcome these objections, and would introduce several new difficulties. See Fujiwara et al.
There have been more traditional approaches to detecting and quantifying the magnetic particles. These have involved some form of force magnetometry in which the sample is placed in a strong magnetic gradient and the resulting force on the sample is measured, typically by monitoring the apparent weight change of the sample as the gradient is changed. An example of this technique is shown in U.S. Pat. Nos. 5,445,970 and 5,445,971 to Rohr. A more sophisticated technique measures the effect of the particle on the deflection or vibration of a micromachined cantilever. See Baselt et al., A Biosensor based on Force Microscope Technology, Naval Research Lab., J. Vac Science Tec. B., Vol 14, No.2 (pg. 5) (April 1996). These approaches are all limited in that they rely on converting an intrinsically magnetic effect into a mechanical response. This response must then be distinguished from a large assortment of other mechanical effects such as vibration, viscosity, and buoyancy.
There would be important applications for an inexpensive, room-temperature, desktop instrument which could directly sense and quantify very small amounts of magnetic particles.
SUMMARY OF THE INVENTION
Broadly speaking, the present invention provides a method and an apparatus for directly sensing and measuring very small accumulations of magnetically susceptible particles, e.g., magnetite, and consequently, their coupled substances of interest.
The magnetic particles or beads are coupled by known methods to analyte particles, thereby providing magnetic sample elements or magnetic bound complexes. A well-defined pattern of the magnetic sample elements is deposited on a surface on a holder. The surface may be flat. A high-amplitude, high-frequency magnetic field is then applied to excite the particles in the sample. The field causes the particles to behave as a localized dipole oscillating at the excitation frequency. The fields from the sample are closely coupled to a sensor, such as an array of inductive sensing coils, which may be fabricated in a gradiometer configuration. This configuration makes the sensing coils mostly insensitive to the large, uniform field that is used to excite the sample. Moreover, the geometry of the coils is designed to match the spatial pattern of the sample so as to provide a large response that varies distinctively with the relative positions of the sample and coils.
The voltage induced across the sensor is carefully amplified and processed by phase-sensitive detection. An inductive pickup from the drive field itself may serve as the reference signal to the phase detector circuit. The output of the phase detector is further filtered and digitized.
The signal amplitude is modulated by moving the sample with respect to the sensor. This allows the rejection of signals due solely to imbalance of the sensor, non-uniformity of the drive field, cross-talk in the circuitry, or any other source of apparent signal which is not due to the sample itself. The digitized shape of the signal amplitude with respect to the sample position is compared to the theoretical response shape using appropriate curve-fitting techniques, providing a very accurate estimate of the magnetic content of the sample in the face of inherent instrument noise and drift.
BRIEF DESCRIPTION OF THE DRAWINGS
The object, advantages and features of this invention will be more clearly seen from the following detailed description, when read in conjunction with the accompanying drawings, in which:
FIG. 1 is a perspective view of a desktop version of an embodiment of the present invention;
FIG. 2 is an enlarged plan view of an embodiment of the sensor, showing sensing coils in the embodiment of FIG. 1 ;
FIG. 3 is a mechanical schematic perspective view of the embodiment of FIG. 1 ;
FIG. 4 is an electrical schematic diagram of the embodiment of FIG. 1 ;
FIG. 4A is an enlarged plan view of the substrate holding the sensing coils of FIG. 1 ;
FIG. 4B is a perspective view of a metal shield for the connection end of the substrate;
FIG. 5 is an enlarged plan view of an alternative embodiment of the sensing coils of the embodiment of FIG. 1 ;
FIG. 6 is a signal waveform of the output of the sensing coils versus the position of the magnetic material;
FIG. 7 is an embodiment of a lateral flow membrane sample holder which may be used in an embodiment of the present invention;
FIG. 8 is an E-core magnet system which may be used as the magnetic field source according to an embodiment of the invention (note that no drive coils are shown for clarity);
FIG. 9 is an embodiment of a microfluidic sample holder which may be used in an embodiment of the present invention; and
FIG. 10 is an embodiment of a single magnet pole piece with attached sensor which may be used in an embodiment of the present invention.
DETAILED DESCRIPTION
Referring now to the drawing, and more particularly to FIGS. 1 and 3 thereof, there is shown a preferred embodiment of the invention.
I. Reader Module
The reader module includes several distinct subsystems. These include: a sample holder with a motion control. The magnetic bound complex samples for measurement reside on the holder, and the same also provides the necessary relative motion within the system. A magnetizer or magnetic field source applies the excitation signals to the samples. Sensors, such as sensing coils, act as the signal pick-up for the signals generated in the samples. A drive circuit supplies the drive current to the coils of the magnetic field source. An amplifier/phase detector/digitizer is coupled to the sensor to receive and process the output signals therefrom. A microcomputer chip provides two-way communication between the external personal computer (PC) and the reader module.
A. Sample Motion Control
Magnetic particles are coupled to analyte or target particles by conventional methods to create magnetic bound complex samples. The analyte particles may include atoms, individual molecules and biological cells, among others. It is noted here that the terms “target particle” and “analyte particle” are used substantially interchangeably. It is further noted that the term “target” is not intended to be limited to the definition of that term as used in the field of DNA recombinant technology.
The magnetic bound complex samples are deposited in accumulations of several to several hundred particles at a number of predetermined positions 11 near the perimeter of a sample holder, such as disc 12 (FIG. 3 ). Other sample holders which may be substituted include lateral flow membranes, plastic strips, or holders employing lateral flow but without membranes. An embodiment employing lateral flow membranes is described in more detail below.
Another type of sample holder may employ microfluidics. A microfluidics system may have a sample sensing chamber and appropriate channeling to move a sample in or out of the sensing chamber using variations in pressure. For example, referring to FIG. 9 , a microfluidic system 151 is shown having an inlet channel 152 . The inlet channel 152 is connected to a mixing chamber 164 . A number of reagent chambers 154 , 156 , and 158 may be provided to hold various chemicals or reagents. As described below, they may also hold magnetically susceptible particles if desired. Near the periphery, or elsewhere, a sample analysis chamber 166 may be located. The location of this chamber is a predefined location and is where the sample magnetic measurement would occur. Accordingly, the sample holder must be configured to allow this chamber to be accessible to the sensor and the magnetic field source. Otherwise, the magnetic measurement may proceed as described elsewhere in this specification. Further processing may occur after the magnetic measurement. For this reason, a measurement chamber 168 is provided, which may also have its own reagent chamber 160 . More reagent chambers may be provided if desired. An optional outlet or exit channel 162 may be provided. Such channels may not be necessary if the device is only a single-use device. Not shown in this figure for convenience but which may also be provided are various pressure inlets and valves which allow analyte particles, magnetically susceptible particles, and reagents to be shuttled around from chamber to chamber.
Analyte particles may be quantitatively measured via measuring their bound magnetically susceptible particles. In the microfluidic system, the samples may be introduced via the inlet channel as combinations of analyte and magnetically susceptible particles. Alternatively, the analyte particles may be introduced via the inlet channel and the two may be combined and mixed in the mixing chamber 164 .
Variations of this system may be manyfold. For example, the sensor may be located directly on the microfluidic chip to match the region of analysis especially well. In another variation, a different parameter on the chip may be varied at the same time or at a different time, such as temperature. Temperature control means may be located on the chip or outside of the chip, such as in the case of laser heating within the mixing chamber. Such a system requires an optical window, as would be understood. Other parameters which may be varied may be anything that affects the presence or property of the magnetic tag, i.e., the magnetically susceptible particle, or its binding to the analyte particle.
The ways the bound complexes may be adhered to the predefined spots on the disc are known and may employ standard technology. The disc is mounted on an axial shaft 13 which extends downwardly to a toothed wheel 14 . An appropriate rotational device, such as a stepper motor 16 , has a shaft 17 extending therefrom with a worm gear member 15 at the distal end thereof. The motor provides controlled rotary motion of disc 12 pursuant to signals applied from a PC 66 through a number of wires 18 . Of course, wireless coupling between the PC and the system of the invention could be used if desired.
In one preferred embodiment, as presently contemplated, disc 12 is about 47 mm in diameter and about 0.25 mm thick. It may be made of glass, plastic or silicon, for example. Its thickness range, for practical functional purposes, would be about 0.1 mm to about 1.0 mm.
In the case where the sample holder is a lateral flow membrane, the sample holder may be made partially porous so that passage of the analyte particles through the porous portion of the holder may be another parameter to be varied. In this case, the magnetically susceptible particles may be bound to the porous sample holder. For example, passage of the analyte particles through a porous portion of a holder may likely depend on the mass or size of the particles. Thus, the location of the particles within the porous portion may be mass-dependent or size-dependent. As the analyte particles pass through the porous sample holder, they may bind preferentially and in a predetermined manner to the bound magnetically susceptible particles. The bound samples, containing analyte particles combined with magnetically susceptible particles, may then be measured magnetically using the device embodied herein. The porous portion of the holder may be replaced with, e.g., a filter as is known in the art. Such filters may be chosen to provide a suitable mass- or size-dependency according to the requirements of the process.
For example, referring to FIG. 7 , a lateral flow membrane 101 is shown. Analyte particles may be flushed into a release pad 102 where they are released into a flow membrane 103 . The particles may then flow by capillary action down the membrane and past a test line 106 on which bound magnetically susceptible particles are located. A control line 108 may also be provided. Finally, an absorbent pad 104 may be located downstream if desired to collect the unbound analyte particles.
In operation, the test line may include colloidal iron particles coated with a material that specifically binds to a material in the analyte of interest. In this way, the test line collects analyte particles preferentially. The control line 108 may have a known amount of colloidal iron for calibration or other such purposes. It should be clear that such a lateral flow membrane may be replaced with, e.g., a gel electrophoresis test area. In this case, of course, the samples are not immobilized but may be moving past the sensing area.
The sample holder may also employ a reference device, such as a bar code 167 , to provide a unique machine-readable tag to identify or locate an individual region or regions and the assay(s) that are associated thereby. The reference device may spatially index the location of an individual region or regions of analysis. The reference device gives a convenient way to identify a sample of magnetic complex material. Besides bar codes, the reference device may alternatively employ a magnetic strip 169 , a microchip, an optical reference, and so on. The reference device may be optically aligned with its corresponding sample for ease of reference.
The computer/CPU may read the reference information along with the magnetic (assay) signal and then display and store the assay results in the appropriate context. For example, an assay to measure the presence of e. coli would likely have results displayed in a different form than an assay testing for the presence of binding of oligonucleotides. Since the substrate may be prepared specifically for each kind of assay, this information can be encoded on the substrate as a bar code or using one of the techniques described above.
In this particular exemplary embodiment, motor 16 rotates wheel 14 , which is connected to disc 12 by shaft 13 , through a 120-tooth worm gear reduction. Of course, rotational drives having different particulars could also be employed.
A magnetic field source 21 may be moved linearly with respect to disc 12 by a rotational device, such as a stepper motor 22 , having a 40 turn-per-circle lead screw 23 on a motor shaft 24 . A boss 25 is configured with a hole having internal threads to which the spiral lead screw threads are coupled. The control signals are applied from microcomputer 65 to motor 22 through a number of wires 26 . Again, the specifics of the rotational drive are set out here as an example only. Other appropriate elements having different characteristics could also be used.
For example, while the above system describes a situation where the magnetic field source is moved linearly with respect to the sample holder, another embodiment may be used in which the sample holder is moved relative to the magnetic field source. In this latter embodiment, the sample holder may be mounted to a shaft and mechanical drive system similar to the drive system shown in FIG. 3 . The drive system may move the sample holder into the gap of the magnetic field source in a controlled manner.
Numerous types of drive systems may be employed. These include stepper motors, screw and motor arrangements, hydraulics, magnetic drives, configurations in which a human operator physically moves the sample holder relative to the magnetic field source and relative to the sensor, pressure drives, pinch rollers, conveyor systems, etc.
The above describes the motion of the sample holder from a location in which samples may be loaded, such as on a disc, to a location near the magnetic field caused by the magnetic field source. Another motion that occurs in the system is the movement of the sample holder past the sensor. Various motions may be caused to accommodate this. For example, two-dimensional motion may be accommodated between the sensor and the sample holder. In the embodiment of FIG. 3 , one degree of freedom motion (e.g., along an arc of a circle) is shown using motor 16 . The drive system of motor 22 may also be employed to translate the sensor along another degree of freedom. Alternatively, another motor may be used to move the sample holder 12 along a similar degree of freedom. Finally, it should be noted that, by using appropriate gearing, the same motor may be used to provide any combination of the above or different motions.
In other exemplary embodiments, the drive system may include a pinch roller which grasps a plastic strip on which a sample is disposed, moving the same past the sensor in a controlled fashion. Such an embodiment may be particularly useful where the sample is placed in a strip on a plastic card similar to a credit card, which is then “grabbed” by a device similar to that used in ATM machines. Of course, the drive system may also be any of the systems described above as well as other alternate systems.
B. Magnetic Field Source
Referring to FIG. 4 , a ferrite toroid core 31 , which is about 30 mm in diameter in the particular embodiment being described, is formed with a gap 32 , which is about 1.5 mm wide. A drive coil 33 is wound as a single layer over about 270 of toroid 31 , symmetric with respect to the gap. A feedback loop 34 encircles the toroid body at a location about 180 from (opposite) the gap. Loop 34 may be outside of coil 33 or between coil 33 and the toroid core. It may include a few or many turns, as necessary and appropriate for the feedback function. The purpose of the feedback loop is to sense or represent the field in gap 32 and enable the signal processing or output circuit to self-correct for variations such as temperature drift. This loop is used to enhance precision and is not essential to proper operation of the system.
Various other magnetic field sources may also be used. For example, while most all employ electromagnets, the electromagnets may be in the form of, e.g., toroids or so-called “E-core”s which are magnets employing the shape of an “E” (see FIG. 8 ). In E-cores, the middle segment of the “E” is made somewhat shorter than the outer segments. Referring to FIG. 8 , two E-cores 112 and 112 ′ are placed with their open sides facing each other. The shorter middle segments then define a small gap 114 therebetween. A sample on, e.g., a plastic strip 116 may then be situated in this small gap. The sensor used to measure the oscillation of the magnetizations may be on a separate substrate 118 also located in the small gap or may alternatively be disposed on the end of one or both of the shorter middle segments. In any of the embodiments, in fact, the sensor may be disposed on a magnetic pole piece or other such element that forms a perimeter of the gap. In this way, the unit may be made more modular and the coil placement more uniform and consistent.
In other embodiments, no gap is needed at all. Referring to FIG. 10 , a single magnetic pole piece 201 may be situated with a sensor disposed thereon or disposed on a separate strip. In FIG. 10 , the sensor is shown as two sensing coils 202 and 204 . The pole piece can alternate the magnetic field, and the sensor can measure the oscillating magnetizations as above.
Referring back to FIG. 3 , the toroidal magnetic field source assembly is mounted in insulative housing 35 , which may be formed from fiberglass. Housing 35 has a slot 36 corresponding to the position of gap 32 . This slot/gap is shaped and configured to selectively receive the edge of rotatable disc 12 , and provides space for the sensing coil substrate, which is described in detail below.
C. Sensors
A sensor is used to measure the magnetic field strength of the samples. In this embodiment, the method used is AC susceptibility. A number of types of sensors may be employed. In the embodiments below, sensing coils connected in a gradiometer configuration are described. It should be noted that the gradiometer configuration is not necessarily required; moreover, other types of sensors may be used. These sensors may include Hall sensors, GMR sensors, or other such sensors capable of measuring magnetic field strength or magnetic flux.
With particular reference now to FIGS. 2 , 4 and 4 A, insulative substrate 41 is disposed in slot 36 in housing 35 and extends into gap 32 . Bonding pads 40 , 42 are provided at a proximal end of substrate 41 and a sensor, in particular sensing coils 43 , is mounted adjacent a distal end of substrate 41 . Preferably the substrate is made of sapphire or silicon and the sensing elements are thin film copper coils. Standard thin film fabrication techniques can be used to construct the substrate and sensing coils, where the leads to and from each coil are on separate different layers. For example, incoming traces 49 may be laid on the substrate surface by standard photolithographic processing methods, a layer of sputtered quartz may then cover the incoming leads, then coils 43 and output leads 44 are similarly applied and a protective layer of quartz may then be added on top. The usual means for connecting between the layers would be used.
The sensing coils, which are connected in series opposition creating a gradiometer configuration, are connected to bonding pads 40 and 42 by conductive traces 44 and 49 , and thence to signal processing circuitry by twisted-pair wires 45 . The twisted pair arrangement is employed to assist in reducing stray signal or interference pickup.
In the spiral form shown in FIG. 2 , the coil traces may be about 5 microns in width with about a 10-micron pitch between spiral traces. The thickness of the sensing coil traces may be about 1 micron. The diameter of each completed coil is about 0.25 mm.
By making substrate 41 relatively long and narrow, bonding pads 40 , 42 are relatively far away from the toroid gap, which helps minimize stray pickup in soldered leads 45 . Metal shield 46 ( FIG. 4B ) may be employed around the bonding area to further contribute to the reduction of stray signals or interference pickup. The shield is essentially a short piece of a thick-walled cylinder, typically formed of copper. The shield provides electrical shielding and facilitates mechanical handling, but is not essential to operation of the embodiment of the invention. The connection (proximal) end of the substrate is slid into slot 50 after the wire connections are made.
An alternative embodiment of the sensing coils is shown in FIG. 5 . The planar configuration of coils 47 is an elongated rectangle. The trace dimensions are about the same as for the FIG. 2 coils and the composite coil width is also about 0.25 mm. The coil length is about 1-2 mm and the coils are connected to bonding pads 52 , 53 by means of leads 48 , 51 .
In another alternative embodiment, two sets of coils may be used. One set of coils may be used as described above, to measure the magnetic moment of the sample. Another set of coils may be employed within the same substrate as a reference set of coils. This reference set of coils may be disposed, e.g., on the side of the substrate opposite that of the sample set of coils. In any case, the reference set of coils is disposed far enough from the sample that the effect of the sample magnetic moment is not detected by the reference set of coils. The reference set of coils is then used to measure the strength of the signal from an analysis region containing a predetermined amount of magnetic material or reference analyte. By comparison of the magnetic field detected by the sample set of coils with the magnetic field detected by the reference set of coils, an even more accurate measurement of the sample magnetic moment may be made. To provide another reference, a magnetic standard may be employed as one of the samples. When such a standard sample is measured, the results may be used to calibrate the system for future or previous measurements. This calibration may significantly help to reduce noise in the system. Auto-calibration may also be employed with such a system, using the differential between signals, to zero the signal.
D. Drive Circuit
The magnetic drive circuit, shown at the left side of FIG. 4 , is built around a pair of high-current, high-speed operational amplifiers 54 , 55 . With the power provided by transformer primary winding 56 , the amplifiers can provide in excess of about one ampere of drive current to magnetizing or drive coil 33 at about 200 kHz. This drive circuit is highly balanced to minimize common-mode noise pickup in sensing loops or coils 43 , 47 .
Small secondary winding 57 coupled to loop 34 around the magnetizing coil provides a feedback voltage to operational amplifiers 54 and 55 to sustain oscillations at a well-regulated amplitude and frequency. This secondary winding 57 also provides an optimum reference signal for the phase-detector circuitry, described below.
This embodiment describes an alternating field as the driving source for the complex of magnetic and analyte particles. In a separate embodiment, the driving source may be non-sinusoidal, e.g., may be a field pulse or a square wave. A variety of other such waveforms may also be used.
E. Amplifier/Phase Detector/Digitizer
A low-noise integrated instrumentation amplifier is the basis for this circuitry, although somewhat better noise performance could be obtained using discrete components. Amplifier 61 is transformer coupled to the sensing coils in order to reduce common-mode noise signals and to facilitate a convenient way to null out imbalance in the magnetic field source and in the sensor. The transformer coupling is conventional, is located in amplifier 61 , and is not specifically shown in the drawing. In an alternative embodiment, amplifier 61 may be replaced by or supplemented with a preamplifier disposed on the substrate. In other words, substrate 41 may have patterned thereon a preamplifier to modify the signals from the sensor prior to the phase-sensitive detection step. Phase sensitive detector 62 is also designed around a special purpose integrated circuit. Phase sensitive detector 62 may be a phase-locking device or alternatively any other type of phase-sensitive device. The output of the phase detector is applied to low-pass filter 63 and is then digitized in A/D converter 64 . The converter may be a high resolution, 20-bit sigma-delta converter, for example. Such a converter chip has adequate hum rejection at both 60 and 50 Hz, which proves to be very helpful in maximizing the sensitivity of the instrument. It is an off-the-shelf item, available from several manufacturers.
F. Microcomputer
Microcomputer 65 includes a microprocessor chip, such as a Motorola HC11, and has a built-in port which supports two-way serial communication to PC 66 by plugging into the serial port of the PC. It also has specialized ports for communication with serial A/D converter 64 and stepper motors 16 and 22 . A simple command language programmed directly into microcomputer 65 allows the PC to send commands and receive responses and data.
Microcomputer 65 may also perform many of the functions previously described above. For example, microcomputer 65 may be equipped with a phase-sensitive device of its own, such as a digital lock-in. Such a microcomputer 65 may acquire the signals, separate data from noise, and display the results.
G. Human Interface
The PC provides the operational command for the system. The PC runs the system through an RS-232 interface, e.g., from the microcomputer. The PC provides a display of the results of the measurements. The display may be, e.g., a computer monitor display or any other form of computer-assisted readout.
II. Operation of the System
In a relatively straightforward and known manner, a well-defined dot or pattern of the magnetic particle complexes comprising the samples is deposited on disc 12 at one or more locations 11 near the periphery thereof. Pursuant to control signals from the PC, stepper motor 22 is energized to rotate lead screw 23 to move the magnetic field source assembly towards sample disc 12 . When a sample position 11 near the peripheral edge of disc 12 is aligned with a sensor such as sensing coils 43 , 47 in the middle of toroidal gap 32 , stepper motor 22 stops and a high amplitude (1 ampere, for example), high frequency (200 kHz) signal is applied to toroidal drive coil 33 . Again, while sensing coils are described below, it should be understood that a variety of sensors may be employed. A signal from PC 66 then energizes stepper motor 16 to rotate the disc and thereby move the sample dot past the sensing coils. The high amplitude, high frequency magnetic field in gap 32 thereby excites the magnetic particles of the sample in the gap. The applied current is intended to drive the toroid to saturation, resulting in the field in the gap have a magnitude of about 1000 oersted. The particles then oscillate magnetically at the excitation frequency, behaving as a localized dipole. Given the close physical proximity of the magnetic particles to the sensing coils, the magnetic fields from the sample are closely coupled to the gradiometer configured sensing coils. Because of the gradiometer configuration of the sensing coils, the output of the sensing coils due to the large, uniform excitation field is substantially null or zero. In order to obtain the largest possible response, the geometry of the sensing coils is configured to match the spatial pattern of the samples. That is, the sample pattern dots are no larger than about 0.25 mm across. The response signal varies distinctively with the relative position of the sample and the coils.
The signal from the sensing coils in the presence of the drive field and in the absence of a sample may serve as the reference signal to the signal processing portion of the system. As the sample moves past one sensing coil and then the other, the phase of the coil output signal reverses by 180 as shown in FIG. 6 , thereby providing a very powerful detection technique. As shown in FIG. 6 , the output may be shown as the response of the sensing coils versus the position of the sample with respect to the sensing coils. The induced voltage is amplified by amplifier 61 and processed by phase detector 62 . That signal is filtered and digitized and passed to the PC through microcomputer 65 to provide the output signals to the PC. Indicator 67 may be any type of useable device to provide information to the system operator. Indicator 67 could be a visual indicator, conveying information numerically or graphically, or could also be a variety of lighting systems, audible indicators, or any combination of these or other possible indicators.
The output signal amplitude is modulated by moving the sample with respect to the array of the sensing coils. This permits rejection of signals due solely to system and external inputs and not due to the sample itself. The digitized shape of the signal amplitude with respect to sample position is compared to the theoretical response shape stored in PC 66 using appropriate curve fitting techniques. These techniques may include phase-sensitive techniques or other techniques yielding similar results. The result of this operation is a very accurate estimate of the magnetic content of the sample to the exclusion of inherent instrument noise and drift.
While a preferred embodiment of the invention has been presented above, some alternatives should be mentioned. Two sensor coil shapes have been shown but numerous other configurations may be employed. Moreover, as indicated above, sensors may be used which are patterned directly on one or more of the magnetic field source pole pieces. Furthermore, other varieties of sensors could be employed besides the types of coils disclosed. For example, balance hall sensors may be employed. In appropriate configurations, these may yield a frequency independent signal. Other sensors which may be advantageously employed include giant magnetoresistance (GMR) sensors, SQUID sensors, magneto-resistance sensors, etc.
In other variations, the magnetic field source is shown as moving with respect to the sample disc, but the disc and coupled stepper motor could be configured to move with respect to the magnetic drive assembly if desired. The toroid core is shown with a rectangular cross section but other shapes are also feasible. As to the number of sample particles in a dot 11 on disc 12 , by way of example, a 0.25 mm dot of sample elements could contain about 10 five-micron size magnetic particles, or about 1200 one-micron size particles.
Thus, in view of the above description, it is possible that modifications and improvements may occur to those skilled in the applicable technical field which are within the spirit and scope of the accompanying claims. | An apparatus is provided for quantitatively measuring samples whose amount or other characteristic quality is to be determined. The samples are arranged in a predefined pattern and are excited in a magnetic field. The magnetizations of the magnetic particles are thereby caused to oscillate at the excitation frequency in the manner of a dipole to create their own fields. These fields are inductively coupled to at least one substantially flat sensor such as sensing coils fabricated in a gradiometer configuration. | 8 |
[0001] Thus, U.S. Pat. No. 4,089,334 describes a disposal spray in which an immunization substance is “fired” without any needle directly through the skin. The immunization substance was located in a cylinder which was closed by a piston. The cylinder face opposite the piston had at least one opening through which the immunization substance could emerge after the propellant charge had been fired. It was fired by means of a firing cap.
[0002] A disposal spray without an injection needle is known from U.S. Pat. No. 4,124,024, in which the active substance could be injected through the skin into the human tissue. The disposal spray had an outlet channel which was provided with a protective capsule and tapered conically in the outward direction. The output channel was closed at its base by a bursting disk. The storage space for the active substance merged from a part with a circular-cylindrical cross section into a conically tapering part, at whose narrowest point the bursting disk was arranged. The active substance to be injected was enclosed between a piston and this bursting disk. The piston surface facing the active substance had a truncated conical space, which was matched to the storage space taper and on whose upper truncated conical surface a conical pyramid was arranged. The other piston surface was designed to be concave. A space was provided between the concave piston surface and the firing charge in order to allow the pressure of the propellant gases to build up against the piston after firing.
[0003] Once the firing charge had been fired, the piston was pressed against the outlet channel, resulting in the bursting disk breaking, but still being held against the channel wall at its edges. The active substance could now emerge through the outlet channel and through the skin. One particular feature in U.S. Pat. No. 4,124,024 was aimed at making it impossible for any explosive gases to reach the outlet channel. A number of sealing points were provided for this purpose: one seal by means of the concave piston surface, one seal approximately in the center of the side piston wall, a further seal in the area of the burst bursting disk, which was pressed against the conical piston surface.
[0004] WO 00/06965 describes a self-defense apparatus. The self-defense apparatus had at least two barrels each having an initial firing charge which could be ignited electrically as well as a shooting charge which had a propellant filling and an active filling, and the self-defense apparatus also had an initiating unit, with a piezoelectric high-voltage pulse source, and a switching unit. One of the initial firing charges could in each case be electrically connected via the switching unit to the high-voltage pulse source for firing. The initiating device had a trigger element, whose manual operation acted on the high-voltage pulse source in order to produce a high-voltage pulse. The switching unit was designed to automatically produce an electrical connection to in each case one initial firing charge which had not yet been fired, without any influence of the propellant filling which had been fired or a battery element. The two shooting fillings were installed in a barrel unit; the barrel unit could be replaced only as an entity. Each shooting filling had a nozzle unit immediately in front of a storage space for the propellant and active filling as well as a propellant charge in order to force the active filling out into free space once the propellant charge had been fired. Each nozzle unit was sealed by a closure element. The closure element was likewise shot out into free space on firing.
DESCRIPTION OF THE INVENTION
OBJECT OF THE INVENTION
[0005] The object of the invention is to provide a defensive apparatus, preferably a self-defense apparatus, which unit which can preferably be used in this defensive apparatus or self-defense apparatus and ensures safe, simple use, since its storage contents (filling) are reliably sealed and, once the storage contents have been “fired”, they are distributed in a predetermined distribution configuration in free space, and in which case only the store contents can emerge, but no other parts, on firing. This storage unit can be integrated in a manner which is not obvious in a self-defense apparatus according to the invention.
ACHIEVEMENT OF THE OBJECT
[0006] A defensive apparatus which is easy to use and has at least one storage unit pair, preferably a self-defense apparatus, which can be operated without any problems even by an untrained user and, furthermore, which cannot be recognized as a “handgun” by a potential opponent is achieved by designing the apparatus to be symmetrical. This means that it has a plane of symmetry with respect to which in each case one storage unit of each pair is located symmetrically. Furthermore, a single initiating device is provided, which has a single control slide, a so-called trigger, by means of which the filling of in each case only one storage unit can be released into free space with a predetermined distribution configuration. The control slide is located centrally between storage units of the pair or of the pairs in the plane of symmetry, in order that the self-defense apparatus can be operated by both left-handed and right-handed people.
[0007] Each storage unit of the storage unit pair has a solid (for example capable of being pulverized), gaseous and/or liquid filling which is stored in a storage space, as well as a pyrotechnically operating propellant charge, in order to force the filling out of the storage space into free space by means of a propellant gas which is produced when the propellant charge is fired, and by whose effect an attacker can be rendered harmless.
[0008] The defensive apparatus, preferably the self-defense apparatus, will preferably be designed to fit the palm of the hand, in order that it can be held in the hand well and, furthermore, can also be concealed well in the hand. One preferred embodiment of the self-defense apparatus has an aperture centrally in the front area, adjacent to the nozzle units, into which the operating slide projects, having an initiation movement which enlarges the aperture cross section. The aperture is designed to be sufficiently large that a free space for a finger is provided between the free edge of the control slide, before it has been pushed in, and the aperture edge. This allows correct operation.
[0009] Each storage unit of the defensive apparatus has a store output, in particular a nozzle unit. The housing contour configuration in the defensive apparatus is preferably chosen such that it does not have any similarity in appearance to a handgun. [lacuna] integrated outlet opening or openings of each nozzle unit will therefore be incorporated in the housing contour, and a flat housing external contour configuration, which fits the palm of the hand well, will preferably be chosen, preferably with a waist in order to improve the position in the hand. In addition to the first plane of symmetry, which has already been mentioned above, one particular embodiment of the housing has a further plane of symmetry which runs at right angles to the first plane of symmetry and, in particular, forms a half-and-half housing subdivision, with a groove, which runs along this housing subdivision, preferably an assembly groove, running centrally to the output of each storage unit, so that the groove can be used as an aiming aid.
[0010] The initiating device has a switching unit which, after ignition of the firing filling and release of the control slide switches the latter such that it interacts with a storage unit which can still be fired, provided such a storage unit is still present. Furthermore, a holding unit can be provided, by means of which it can be attached to the clothing of the person carrying it.
[0011] Safe use of the storage unit according to the invention on its own or installed in a defensive apparatus is achieved by making it impossible for any fragments of a closure element, which closes the storage space and bursts after firing of the propellant charge, to reach the exterior.
[0012] If the storage unit is used, for example, in a self-defense apparatus, the aim is to provide for the active substance to be forced out as uniformly as possible over a predetermined time period, in order to achieve a uniform jet pattern formed by the emerging storage contents (filling), thus increasing the accuracy of aiming at an attacker. Forcing it out in a uniform manner in this way firstly means that a nozzle entry space is provided between the closure element and the nozzle inlets, and acts, inter alia, as a stabilizing space. This nozzle entry space is also required for correct opening of the closure element and to provide the necessary space for its parts that are torn away. The presence of this nozzle entry space thus prevents nozzle channels from being blocked or their cross-sections from being reduced by parts torn away from the closure element. Once the filling has been released by the closure element, it flows first of all into the nozzle entry space, by which means it is very largely possible to dissipate peak pressures of the filling being fired into it, and vortices. Only then do the “stabilized” storage contents enter the nozzle channels, and can then leave these channels with the desired configuration and effect on the target.
[0013] If the storage unit is integrated in a defensive apparatus, then the configuration of the emerging filling, mainly the jet directed at the attacker, should have as constant a pressure as possible. The propellant filling is over designed in order furthermore to ensure that it is forced out in a uniform manner. In addition, an expansion space is provided between the piston surface which forces out the filling and the propellant filling. This results in the first pressure peak after firing being absorbed, thus assisting the process of forcing out with an approximately constant force, and hence with a filling configuration which is constant over the forcing-out period, into free space.
[0014] On the other hand, furthermore, a pressure relief means is provided which, in contrast to the storage unit which is described for example in U.S. Pat. No. 4,124,024 but is not of this generic type, ensures that the propellant gas escapes completely. When firing the filling which is stored in the storage unit, no solid parts reach the exterior. In addition, the fired storage unit has no internal space subjected to the pressure of the propellant gas; it thus no longer involves any dangers.
[0015] In order to achieve a predetermined filling distribution in free space, the propellant filling must be overdesigned. This means that the propellant filling cannot be chosen such that it would just be sufficient to drive the piston forward. A certain residue pressure must therefore also still be present when the piston is in the final position. This residue pressure is then dissipated by means of a special configuration, described below, of the piston, which forces out the filling, and of the store wall, so that this residue pressure can be discharged through the nozzle channels.
[0016] In order to achieve a predetermined filling distribution (active substance distribution) in free space, a number of nozzle channels will furthermore preferably be used: at least one nozzle main channel for the long-range effect (concentrated jet) and at least one secondary channel, and preferably a number of secondary channels, arranged around it for the short-range effect (jet with a wide opening angle). The closure element, which has already been mentioned above, closes all the nozzle channels via the nozzle entry space. When the propellant charge is fired, the closure element, which is preferably in the form of a bursting disk, is then torn open in such a way that the segments remain held such that they are secured well at their edges. The tearing-open process also takes place in such a way that the fragments do not impede the filling flow to the nozzles. The bursting disk can also have points with notches incorporated in them in advance, or points where the material is thinned, in order to tear open in a predetermined manner.
[0017] When the storage unit is used in a defensive apparatus, one nozzle unit will be designed with at least one main nozzle channel and at least one secondary nozzle channel, but generally with a number of secondary nozzle channels, arranged around it. If the filling is a liquid, the main nozzle channel should produce a straight jet up to a range of four meters, and the secondary nozzle channels should produce a large filling cloud up to two meters.
[0018] In order to allow the storage unit to be handled safely, care should be taken to ensure that the pressure does not remain raised after “firing” even with an overdesigned propellant filling. As described below, this raised pressure is produced by a special configuration of the piston, which forces out the filling, and/or of the end area of the storage space. When the piston reaches this end area, then the raised pressure can be dissipated past the piston sidewall, through the nozzles.
[0019] The complete dissipation of the residue gases through the nozzle unit also has another advantage: specifically, if the piston is located in the storage space in its limit position, then all the filling which is still located in the storage space, in the nozzle unit and in the nozzle entry space will be blown out here. The amount of filling can thus be predetermined in an optimum manner. No more filling can thus emerge from a defensive apparatus which has been disposed of or from a fired defensive apparatus to be disposed of; this precludes any danger retrospectively to those not involved with the apparatus.
[0020] If the storage unit is used in a self-defense apparatus, then an irritant liquid or an irritant gas is used as the filling (active substance), although powdery substances can also be used.
[0021] The substances listed below may be used, by way of example, as liquid active substances:
[0022] A Capsaicin solution is already used at the moment in known “pepper sprays”. Capsaicin is an extract from the chilly pepper plant which is generally dissolved in a concentration of between 1% and 4% in alcohol. Capsaicin leads to sudden, temporary inflammation of all the mucus membranes with which it comes into contact (for example eyes, breathing passages). Capsaicin is thus effective both against people and animals. In contrast to Lacrimonium, which is mentioned in the following text, it leads to involuntary closure of the eyes.
[0023] A CS solution can be used as a further liquid filling (active substance). CS is a Lacrimonium which produces tears. As an additional effect, it produces severe nettle rash on the skin. CS is effective only against people.
[0024] CN solutions may also be used. CN leads to nausea. However, it acts more slowly than the CS or Capsaicin solution.
[0025] Foul-smelling secretions can also be used as liquid fillings. Most foul-smelling secretions also lead to nausea.
[0026] CS and CN may also be used in gaseous form, instead of a liquid filling.
[0027] Capsaicin, for example, may also be used as a solid filling (active substance) for self-defense, and is crystalline in its pure form at room temperature. However, solutions act more quickly than fillings which are emitted in solid form and are then pulverized. Nonetheless, pulverizing fillings have the advantage that they remain as a cloud in space for a certain period of time.
[0028] Mixtures of liquid and gaseous substances may also be used as fillings. These are then often foams which adhere to the attacker being defended against. Once again, Capsaicin may be used here.
[0029] Mixtures of solid and liquid active substances likewise often contain Capsaicin. These are, for example, gels. Dies may also be used for subsequent identification and marking of a criminal.
[0030] Further advantages of the invention and its embodiment variants will become evident from the following statements.
BRIEF DESCRIPTION OF THE DRAWINGS
[0031] Examples of the storage unit according to the invention and of its preferred integration in a defensive apparatus according to the invention will be explained in more detail in the following text with reference to the following drawings, in which:
[0032] [0032]FIG. 1 shows a cross section through a storage unit according to the invention whose propellant charge has not yet been fired;
[0033] [0033]FIG. 2 shows a cross section through the storage unit illustrated in FIG. 1, shortly after firing of the propellant charge;
[0034] [0034]FIG. 3 shows a cross section through the storage unit illustrated in FIG. 1, after firing of the propellant charge and with the filling (active substance) having been forced out completely;
[0035] [0035]FIG. 4 shows a view of the rear face of the defensive apparatus according to the invention;
[0036] [0036]FIG. 5 shows a side view of the defensive apparatus illustrated in FIG. 4, viewed in the direction IV in FIG. 4;
[0037] [0037]FIG. 6 shows a plan view of the end face, facing a potential attacker, of the defensive apparatus illustrated in FIG. 4, looking in the direction V in FIG. 4;
[0038] [0038]FIG. 7 shows a plan view of the “interior” of the defensive apparatus illustrated in FIG. 4, with one half of the housing removed;
[0039] [0039]FIG. 8 shows an enlarged illustration of only the upper symmetrical part of the “interior” illustrated in FIG. 7;
[0040] [0040]FIG. 9 shows a schematic illustration of the movement sequence on operation of the control slide of the initiating device of the defensive apparatus in the direction of the arrow as shown in FIG. 4, with this figure still showing the rest position; the left half of the figure shows the rotor and the extension bolt in a “developed” illustration, and the right half of the figure shows a plan view of the extension bolt with the rotor lying on it (shown dotted and filled); the dashed lines show the guide curves 60 a , which are likewise shown by dashed lines in FIG. 8; in order to allow details to be identified well by their reference symbols, the illustration in this figure has been chosen to be larger than an analogous illustrations in the subsequent FIGS. 10 to 14 ;
[0041] [0041]FIG. 10 shows an illustration analogous to FIG. 9, with the control slide having been pushed in through the distance a shown in FIG. 9;
[0042] [0042]FIG. 11 shows an illustration analogous to FIG. 9, with the control slide having been pushed in completely, and the firing filling having just been fired;
[0043] [0043]FIG. 12 shows an illustration analogous to FIG. 9, with the control slide having just been released, and the rotor starting to rotate in the rotation direction;
[0044] [0044]FIG. 13 shows an illustration analogous to FIG. 12 with a rotor shortly before reaching its limit position;
[0045] [0045]FIG. 14 shows an illustration analogous to FIG. 9, with the rotor and the extension bolt being located in their new rest position, in which the rotor is ready to be pushed in once again in order to engage with another storage unit;
[0046] [0046]FIG. 15 shows a variant of the embodiment of a storage space end area of the storage unit illustrated in FIGS. 1 and 3;
[0047] [0047]FIG. 16 shows a variant of a defensive apparatus with piezoelectric firing;
[0048] [0048]FIG. 17 shows an “exploded illustration” of the defensive apparatus shown in FIG. 16, as a variant;
[0049] [0049]FIG. 18 shows a cross section through a variant of the defensive apparatus illustrated in FIGS. 4 to 8 as well as 16 and 17 ;
[0050] [0050]FIG. 19 shows an “exploded illustration” of the defensive apparatus illustrated in FIG. 18;
[0051] [0051]FIG. 20 shows a cross section through the front part of a storage unit which is illustrated in an analogous manner to the storage unit illustrated in FIGS. 1 and 3, but with the closure element being in the form of a moving “sealing ring”;
[0052] [0052]FIG. 21 shows a cross section analogous to FIG. 20, but with the closure element in this case releasing the filling to be forced out, however,
[0053] [0053]FIG. 22 shows a section along the line XXII-XXII in FIG. 20,
[0054] [0054]FIG. 23 shows a longitudinal section through a variant of the storage units illustrated in FIGS. 1 to 3 , before it has been fired,
[0055] [0055]FIG. 24 shows a longitudinal section through the storage unit illustrated in FIG. 23 after the filling has been forced out,
[0056] [0056]FIG. 25 shows a longitudinal section through the storage unit illustrated in FIGS. 23 and 24 with the filling tank removed, and
[0057] [0057]FIG. 26 shows a longitudinal section through the filling tank removed in FIG. 25, which is provided as a spare part.
APPROACHES TO IMPLEMENTATION OF THE INVENTION
[0058] The storage unit 1 illustrated in the form of a cross section in FIGS. 1 to 3 is designed as a so-called cartridge and is preferably used in a defensive apparatus, preferably a self-defense apparatus. On the left in FIGS. 1 to 3 , the cartridge 1 has a nozzle unit 3 . Furthermore, the cartridge 1 has a storage space 5 , a pyrotechnic propellant charge 7 and a pyrotechnic firing charge 9 for firing the propellant charge 7 . FIGS. 1 to 3 furthermore show a mechanical firing cap unit 10 which, however, is part of the self-defense apparatus 11 described in the following text. The striking unit 13 of the firing cap unit 10 is held in a catch 14 in its rest state as illustrated in FIG. 1. The striking unit 13 can be rotated by means of a mechanism, which is described in the following text, out of the catch 14 in order to release a free striking path.
[0059] Depending on the purpose, solid (which can also be pulverized), gaseous and/or liquid fillings (active substances) 15 can be stored in the storage space. Mixtures between powdery, gaseous and/or liquid different active substance components can also be stored. A liquid filling 15 is stored in the exemplary embodiment illustrated here. Since, in accordance with the description in the following text, the storage unit 1 is intended to be integrated in a self-defense apparatus 11 , the filling 15 is intended to achieve an immediate effect on the mucus membranes (eyes, breathing passages) of a potential attacker. The storage space 5 , which is filled with the filling 15 , is sealed toward the nozzle unit 3 by a closure element 19 which has material thinning lines 17 arranged in a star shape. The closure element 19 prevents the filling 15 from escaping from the storage space 5 through the nozzle unit 3 when it is not being fired.
[0060] The storage space 5 is closed in a sealed manner toward the propellant charge 7 by a piston 21 which is fixed in a clamped seat in the cylindrical wall 20 of the storage space 5 . The piston 21 is designed like a pan with a pan base 22 and a pan casing 23 . The piston 21 is also referred to as a propellant disk. The pan interior 24 , as a free space between the propellant charge 7 and the pan base 22 which is connected to the filling 15 , is used as an expansion space 24 in order to move the piston 21 forward as uniformly as possible, eliminating any pressure peaks, once the propellant gases have been produced from the ignited propellant charge 7 . The expansion space 24 has a volume which is approximately equivalent to one eighth of the liquid volume of the filling 15 . The seal can also be provided by an additional sealing element (O ring, lipseal, . . . ).
[0061] Pressure relief means 27 are arranged in the storage space end area 25 adjacent to the nozzle unit 3 . In this case, the pressure relief means 27 are designed, by way of example, as webs which project into the storage space end area 25 . As the name itself suggests, the pressure relief means 27 are used to reduce the pressure of the propellant gas in the storage area 5 once the filling has been forced out completely. The method of operation is explained in the following text. With the complete dissipation of the residue gases, the remaining residue of the filling is also blown out of the storage space 5 , out of the nozzle unit 3 and out of the nozzle entry area 29 . The amount of filling can thus be predetermined in an optimum manner.
[0062] A nozzle entry space 29 which, inter alia, can act as a stabilization space, is provided between the closure element 19 and the start of the nozzle channels in the nozzle unit 3 . The nozzle entry space 29 is in this case designed with a circular-cylindrical diameter; other cross sections are, of course, possible. The nozzle entry space 29 is used, as can be seen in particular in FIG. 2, to provide space for those parts 19 a of the bursting disk 19 which are torn off by the build up in pressure on firing, without blocking the nozzle main and secondary channels 31 and 32 , and on the other hand to stabilize the accelerated filling 15 and to minimize the vortices in the liquid in the nozzle channels. The depth h of the nozzle space 29 is preferably greater than its internal radius q/2. The bursting disk 19 is thus stretched freely in front of the nozzle entry space 29 while, in contrast, its edges are firmly clamped. Thus, once the burning propellant charge reaches a predetermined gas pressure, the bursting disk 19 tears in a star shape, that is to say starting from the center. This radial tearing in the form of segments ensures that no fragments of the bursting disk 19 are shot as solid bodies out of the nozzle unit 3 , since the edges of the bursting disk 19 are still held firmly. The torn off bursting disk segments then rest against the wall of the nozzle entry space at the side, without blocking the nozzle channels, since this is deeper than the length of the torn-open segments of the bursting disk 19 . The nozzle entry space 29 thus carries out two functions: it allows the closure element to open without parts of it being torn off or blocking the nozzle channels or in any way impeding the flow, and it produces the pressure peaks and vortices of the filling which is fired into it. It thus assists the filling being passed without vortices through the nozzle channels in a predetermined configuration. The nozzle entry space and the closure element (when in the open state) are matched to one another in order to carry out this function.
[0063] The nozzle unit 3 has a centrally arranged main nozzle channel 31 and a number of coaxially arranged secondary nozzle channels 32 , in this case four. A number of main nozzle channels and only one secondary nozzle channel or a number of main channels and a number of secondary channels may, of course, also be provided. The number and arrangement of the nozzle channels are governed by the application and the desired spatial distribution of the filling. The four secondary nozzle channels 32 open, for example, into an annular space 28 which surrounds the main nozzle channel 31 which, in order to “atomize” the liquid emerging from the secondary nozzle channels 32 , has a circumferential incline 30 on which the secondary jets are broken and atomized. The main nozzle channel 31 is designed such that an approximately straight liquid jet emerges from the filling 15 , which is forced out by the propellant gas, up to a distance of four meters, having large droplets after the droplet formation process. The secondary nozzle channels 32 are intended to produce a large scatter circle with finely distributed small droplets of filling as an active substance cloud.
[0064] In order to force out the filling 15 in the case of a storage unit 1 which is integrated in a self-defense apparatus 11 , the striking unit 13 is unlocked in a first step. The unlocking process takes place by rotating the catch 14 out of its holding position. The striking unit is then pushed to the right in FIG. 1, loading a spring 33 , and is then released. The force of the loaded spring 33 shoots the striking bolt 34 of the striking unit 13 against the firing charge 9 , which ignites and acts as an initial igniter for the propellant charge 7 . The propellant charge 7 starts to burn, with the propellant gases which are produced entering the expansion space 24 and, after a short time interval, the propellant gas expansion force exceeding the clamping force of the piston 21 with the storage space wall 20 , so that the piston 21 is driven in the direction of the nozzle unit 3 . The pressure in the filling 15 arises suddenly. This pressure rise acts on the bursting disk 19 , which tears open along its thinned material lines 17 , which are arranged in the form of a star. The bursting disk 19 is held well at its outer edges in front of the nozzle entry space 29 . Although it tears open, no fragments moving away from it are formed, however, since the bursting disk edge is held firmly even after the bursting disk has torn open. The bursting disk segments rest against the wall of the nozzle entry space 29 , as indicated in FIG. 2. They do not impede the liquid emerging through the nozzle unit 3 , since the depth h of the nozzle entry space 29 is deeper than the length of the torn-open bursting disk segments 19 a . The nozzle entry space 29 thus allows the bursting disk 29 to tear open in the form of a star into segments as desired, and on the other hand, also serves to prevent vortices in the active liquid (filling which is forced out) in the nozzle channels themselves. These vortices resulting from partially concealed and a blocked nozzle channel inlets would have a negative influence in particular on the range of the liquid jet emerging through the main nozzle channel 31 .
[0065] When the piston 21 enters the storage space end area 25 , its slides over the pressure relief means 27 , which are in the form of webs. This sliding-in process results firstly in deformation of the piston 21 and secondly in a braking effect, thus preventing it from striking the nozzle unit 3 . This prevents parts of the nozzle unit 3 or of the storage unit 1 a or 1 b from being torn off when the piston (propellant disk) 21 strikes in the storage unit end area, and flying away with high inertia. The transition between the nozzle unit 3 and the wall 20 need in consequence not be designed to be as robust, which allows a simpler structure. The deformation of the piston 21 results in side channels 35 between the wall 20 and the pan casing 23 . The remaining propellant gas can then escape through these channels 35 , as indicated by the arrows 37 in FIG. 3. The remaining gases are in this case blown out through the nozzle unit 3 . This also results in the nozzle channels being blown out completely so that no residue amount of filling remains in them. The self-defense apparatus can be placed down at any desired location after being fired without any possibility of the filling residue causing any effect whatsoever. After being fired, the remaining storage unit 1 can be handled and stored without any pressure, and thus without any problems.
[0066] The described configuration of the closure element, in this case the bursting disk 19 , of the nozzle entry space 29 which is matched to it, as well as the pressure relief means 27 ensures that no solid parts, such as parts of the nozzle unit 3 , of the piston 21 or of the closure element (bursting disk 19 ) can be shot out on firing. A self-defense apparatus 11 fitted with this storage unit 1 may thus be sold without any restrictions in most countries, since there is no risk of injury to an attacker being fired at by particles (fragments, bursting disk parts).
[0067] This storage unit may, but need not, be integrated in the self-defense apparatus according to the invention as described in the following text. The self-defense apparatus described in the following text may itself also understandably be fitted with other storage units, carrying a filling, for defense against attacks. Such integration achieves the object of providing a self-defense apparatus which on the one hand can be used without any problems by people without any training, and does not represent a residual risk after being “fired”. The self-defense apparatus can also be designed such that it has no similarity whatsoever to a handgun, and nevertheless allows good aiming.
[0068] Self-defense apparatuses which cannot be recognized as handguns are known. By way of example WO 98/38468 describes a self-defense appliance which cannot be recognized as a pistol. The appliance has the appearance of a key tag. It has two barrels, whose fillings can be initiated by means of in each case one initiating button per barrel. Firing bolts which can be prestressed are provided for igniting the firing filling. A solid body is fired as the projectile.
[0069] Self-defense appliances designed in an analogous manner to this are known from U.S. Pat. No. 1,741,902, DE 3 310 155 and FR 776 954. FR 776 954 allows the use of a large number of cartridges; among other cartridges, these also include teargas cartridges.
[0070] DE-A 196 24 582 describes a storage unit which can be used as a defensive apparatus for liquid fillings, which vaporize on use. A blocking sheet was arranged immediately in front of the nozzle inlets, sealing them. The blocking sheet was used to prevent the filling from emerging inadvertently through the nozzle passages. A firing charge was ignited in order to force out the filling, and its propellant gases acted on a piston which in turn built up a pressure in the filling until it burst the blocking sheet in front of the nozzle inlets. When the blocking sheet burst, its fragments were forced into the nozzle passages, following the filling either as parts through the nozzle channels to the exterior, or remaining stuck in these nozzle channels, thus impeding the process of forcing out the filling.
[0071] Instead of a blocking sheet, U.S. Pat. No. 2,432,791 used a wax plug in front of the nozzle inlet. When it is shot out, this wax plug also acts as a projectile and can cause injuries. If it is not shot out, it can also lead to blocking of the nozzle channel or to an adverse effect on the flow of the filling in the nozzle channel.
[0072] All these appliances lack safety in use and/or in final storage, however.
[0073] The object of providing a self-defense apparatus which can be used without any problems is achieved in that this apparatus has two storage units, which are arranged symmetrically with respect to a plane of symmetry, as well as only a single trigger for the storage units which can be “fired” successively, with automatic switching to a storage unit which can then still be fired. The self-defense apparatus is designed such that it can be operated by both left-handed and right-handed people. Further advantages of the self-defense apparatus are described in the following text.
[0074] The self-defense apparatus 11 as illustrated in FIG. 4 has a first plane of symmetry 41 , symmetrically with respect to which in each case one storage unit 1 a or 1 b , which cannot be seen directly, is integrated as a pair. Of the two storage units 1 a and 1 b only the nozzle outlets of the respective nozzle unit 3 of the main nozzle channel 31 and of the secondary nozzle channels 32 can be seen when a front view (FIG. 6) is viewed in detail. A single control slide 43 for initiating in each case one storage unit 1 a or 1 b and for operating a switching arrangement 97 is arranged in the plane of symmetry 41 . Ignoring a clip (holding unit) 45 for attaching the self-defense apparatus 11 to the clothing of a user, this self-defense device 11 is also designed to be symmetrical with respect to a further plane of symmetry 46 , which is illustrated in FIG. 5 and runs at right angles to the first plane of symmetry 41 through the center axes of the two storage units 1 a and 1 b and of the control slide (trigger) 43 . The two planes of symmetry 41 and 46 apply mainly to the housing and to the arrangement of the storage unit with the control slide 43 . The functional elements relating to the initiating unit 59 and to the switching arrangement 97 are not symmetrical together with these planes of symmetry 41 and 46 .
[0075] The self-defense apparatus 11 is designed to fit the palm of the hand. It has an aperture 47 centrally in the front area, through which the trigger finger can be passed. The control slide 43 projects into this aperture 47 . When the control slide 43 is operated in the direction of the arrow 49 , the free cross section of the aperture 47 is enlarged as a result of the initiation movement. The aperture cross section 47 between the free edge 44 of the control slide 43 and the aperture edge 50 is sufficiently large to provide space for a finger to be passed through. The outlet openings of each nozzle unit 3 are integrated in the housing contour (however, they could also project beyond it). The housing of the self-defense apparatus 11 is designed to be flat, in order that it fits well in the palm of the hand and can thus be carried concealed. Furthermore, a waisted indentation 51 a and 51 b is provided on each of the two sides, in the form of a waist in the housing, in order to allow better handling. In fact, one indentation would actually be sufficient but, since the self-defense apparatus 11 is intended to be usable by both left-handed and right-handed people, indentations 51 a and 51 b are required on both sides. The housing is designed in two parts. The two housing parts 53 a and 53 b are in this case, for example, connected to one another in a fixed manner, and cannot be opened up, in contrast to the housing which can be opened up as explained further below. The connecting point between the two housing parts 53 a and 53 b is a circumferential groove 55 , which lies on the plane of symmetry 46 . This groove 55 runs on the plane of symmetry 46 . This groove 55 can thus be used not only as a visible aiming aid but also as a tactile aiming aid for aiming at the potential attacker.
[0076] As shown in FIGS. 4 to 6 , the appearance of the self-defense apparatus is similar, for example, to the reel of a wind-up dog's lead unit, to a purse, to a credit card wallet, or to other objects, but not to a handgun. Since a potential attacker cannot recognize the self-defense apparatus 11 as a weapon, the attacker's aggressiveness is not increased by it either. On the contrary, the attacker will consider himself safe and superior. He will thus be completely surprised by view, in the right-hand half of the illustration in FIGS. 9 to 14 . FIGS. 9 to 14 show the relative movement sequence of the rotor 63 with respect to the extension bolt 61 , and the movement of the striking unit 13 b (FIG. 8). At their free ends, the webs 67 a to 67 f have two roof-like inclines 71 a and 71 b , which are designed to be symmetrical with respect to one another. The inclines 71 a and 71 b continue into the grooves 69 a to 69 f , to form in each case one V-shaped symmetrical incision 72 .
[0077] The rotor 63 has three coaxially running webs 75 a to 75 c , which are at equal angularly distances from one another, as well as three truncated webs 76 a to 76 c , which are arranged centrally between the webs 75 a to 75 c . The webs 75 a to 75 c and the truncated webs 76 a to 76 c each have an incline 77 , like a desktop. The inclines 77 on the rotor 63 and the inclines 71 a and 71 b on the extension bolt 61 engage in one another in conjunction with the guide curves 60 a analogously to the pressing mechanism of a ballpoint pen, with a point which can be pushed down and pulled in again. The catch, which has already been mentioned above and is annotated 14 b here, since it is part of the storage 1 b , is guided in the guide curve 60 b . The guide curve 60 b is not shown in FIGS. 9 to 14 .
[0078] When the control slide 43 is pushed in in the direction of the arrow 49 , then the movement sequence illustrated in FIGS. 9 to 14 takes place. The rotor 63 is in this case likewise pushed in this direction, and is rotated in the process. The rotor 63 does not rotate at all until the control slide 43 (FIG. 10) has been pushed in virtually completely. During the pushing-in process, both the return spring 65 and the spring 33 b which acts on the striking unit 13 b are loaded. Once this position has been reached, and only then, the rotor 63 is rotated in the direction 82 such that the desktop surfaces 77 slide on the roof inclines 71 b into the incisions 72 . As a result of this rotation 82 and the rotation of the striking unit in the guide curve 60 b , a projection 81 b slides on the striking unit 13 b into a groove 80 between the webs 75 a and 75 c . The striking unit 13 b is now shot against the firing charge 9 b by the force of the spring 33 b (FIG. 11), as a result of which this charge 9 b is ignited by the firing bolt 34 . The ignited firing charge 9 b then causes the propellant charge 7 to burn.
[0079] The propellant gases from the burning propellant charge 7 then flow into the pan interior 24 , which is used as an expansion space. Once a sufficient propellant gas pressure has built up, the piston 21 , which acts as a propellant disk, is driven forward. The piston 21 presses against the filling 15 which, for its part, acts on the closure element 19 which acts as a bursting disk. The closure element 19 tears open along its thinned material lines 17 , which are arranged in the form of a star; however, it remains held at its edges, as shown in FIG. 2. The piston 21 is driven by the propellant gases toward the storage space end area 25 , forcing out the filling 15 through the main nozzle channel 31 and through the secondary nozzle channel 32 . On reaching the storage space end area 25 , the entire piston 21 is deformed by the webs located on the store wall, as a pressure relief means 27 , or only its sealing elements are deformed. The deformation of the piston surface 22 also results in its side walls 23 being partially pushed in, thus forming channels 35 between the piston side wall areas and the store wall in the storage space end area 25 . The propellant gas can then escape through these channels 35 until the pressure is completely relieved. However, as a design variant, it is also possible to deform only one sealing element, which is fitted on the piston 21 (for example a lip seal).
[0080] When the control slide 43 is released, then the return spring 65 moves it back to its front position. In a first return step shown in FIG. 12, the webs 75 a to 75 c and the truncated webs 76 a to 76 c slide along an incline 83 on the guide curves 60 a , causing a small amount of further rotation in the direction 82 . The rotor 63 then slides back axially as far as a further incline 84 on the guide curves 60 b (FIG. 13). The desktop inclines 77 on the webs 75 a to 75 c and on the truncated webs 76 a to 76 c then slide on the inclines 71 a of the webs 69 a to 69 f of the extension bolt 61 into a new rest position (FIG. 14). In the new rest position, the projection 81 a which is associated with the striking unit 13 a is now ready to engage with the rotor 63 once again in order that the other storage unit 1 b can be “fired” when the control slide 43 is pushed in again.
[0081] In contrast to the statements made above, the thinned material lines 17 in the closure element 19 can be dispensed with. This element 19 is then, for example, in the form of a thin aluminum disk.
[0082] Instead of relieving the propellant gas pressure by deformation of the piston 21 by means of the webs 27 projecting into the storage space end area 25 as described above, it is also possible, as illustrated in FIG. 15, to form grooves 85 in the store wall, in the storage space end area 86 there. The grooves 85 must then be longer than the height d of the piston 87 , which is designed in an analogous manner to the piston 21 , by a tolerance allowance. Once the filling has been forced out, the piston 87 strikes against a step at the end of the storage space in this embodiment variant. This means that there is a hard stop after firing, while there is only a damped stop in the embodiment variant described above with the pressure relief means 27 .
[0083] A self-defense apparatus 90 which has a piezoelectric firing instead of a mechanical firing cap is illustrated in a longitudinally sectioned form in FIG. 16. The external contour of this self-defense apparatus 90 is identical to that described above. Its two storage units 91 a and 91 b are also constructed identically, except for the firing and propellant charge 93 a and 93 b . In this case as well, there is an expansion space 24 for the propellant gases in the exterior of the piston 21 , which is in the form of a pan.
[0084] An initiating device 94 for the self-defense apparatus 90 in this case, analogously to the self-defense apparatus 11 , has a control slide 95 as the “trigger”. The control slide 95 is held in its rest position by a compression spring 96 . An arrangement 97 having a piezoelectric high-voltage pulse generator and an integrated electrical switching arrangement is acted on only once a pushing-in movement has been overcome. The arrangement 97 is inserted into an electrical printed circuit board 99 with electrical connections, which are not shown, to the firing and propellant charges 93 a and 93 b.
[0085] Since the electrical components (high-voltage pulse generator, electrical switching, various contacts, conductors to the firing and propellant charge) of this embodiment variant are sensitive to moisture, importance is in this case placed on a water seal.
[0086] The electromechanical design of this self-defense apparatus 90 is shown schematically, in the form of an exploded drawing, in FIG. 17. The two housing parts 53 a and 53 b are shown at the top and bottom. The clip 45 is latched into the housing part 53 b ; although it could also be bodied or welded to it. A central injection molded part 100 has a rear cover which, after the “interior items” have been installed, is welded in a liquid-tight manner to the base housing (injection molded part) 100 . The sealing rings 110 (sliding seal) and 105 , which are likewise watertight, seal the base housing 100 in a liquid tight manner, as is necessary owing to the electromechanical devices contained in it. The housing parts 53 a and 53 b in this design variant thus have only a “bodywork function”, since the base housing 100 already contains all the technical functional parts and is sealed in a liquid-tight manner. The housing parts 53 a and 53 b in this case thus just need to be clipped to one another.
[0087] Furthermore, the two storage spaces 101 a and 101 b in the storage units 91 a and 91 b as well as a holding sleeve 103 for the piezoelectric high-voltage generator 104 are provided. A sealing ring 105 can be placed on each bursting disk 19 . The nozzle units 3 are located in recesses 109 and 107 in the respective housing parts 53 a and 53 b and press against in each case one of the sealing rings 105 , forming a seal. The control slide 95 is likewise sealed by a sealing ring 110 from the interior of the self-defense apparatus 90 . The control slide 95 is guided in a box-like sheath, although only the half box 111 , which is formed in the housing part 53 a , can be seen in the illustration in FIG. 17. The control slide 95 is protected against falling out in the direction of the aperture 47 by in each case one projection 113 at the side, which in the assembled state is formed into a corresponding groove, formed from the half boxes and the inserted injection molded part 100 . The two pistons 21 are likewise each sealed by a sealing ring 115 .
[0088] The storage units 1 a , 1 b , 91 a and 91 b according to the invention are used integrated in a self-defense apparatus in the exemplary embodiments described above. These storage units 1 a , 1 b , 91 a and 91 b may, however, also be used in a fixed position in the immediate vicinity of objects which are at risk. Objects such as these may be, for example, glass cabinets, shopwindows or entry doors to jewelry businesses, private villas etc. The firing charge for the storage units may, for example, be coupled to a glass-breakage sensor. As soon as someone breaking in breaks such a secured window, a storage unit installed in a fixed position is fired. The active substance (filling) which then emerges from the storage unit “forms a mist” in the room area in which the person breaking in is at that time located. The criminal is in this way kept away from his objective and, depending on the active substance that is used, is marked or is rendered incapable of movement for a predetermined time period. When the glass breakage sensor is triggered, an alarm is preferably triggered at the same time, and/or an alarm is sent to the police.
[0089] A cross section of a further variant of a self-defense apparatus 120 with respect to the variants illustrated in FIGS. 4 to 8 as well as 16 and 17 is shown in FIG. 18. The contour of the housing corresponds to that shown in FIGS. 4 to 6 . In this case as well, there are two storage units 121 a and 121 b for an active substance. In contrast to the self-defense apparatus shown in FIGS. 7, 8, 16 and 17 , the self-defense apparatus 120 has no rotating switching mechanism for firing the propellant filling, but a switching link 123 . While the rotating switching process takes place in three dimensions, the switching link operates in a two-dimensional manner. A control slide (trigger) 124 produced from plastic has two sprung arms 125 a and 125 b and is held in its rest position by a compression spring 127 . The switching link 123 and the sidewalls 129 a and 129 b for the storage spaces 130 a and 130 b form a single injection-molded part 130 . The firing pins 133 a and 133 b , which are used to fire a respective firing unit 134 a and 134 b , are always subject to the pressure of a respective spring 135 a or 135 b . The firing pins 133 a and 133 b are thus already prestressed in the rest state. The two firing pins 133 a and 133 b are held in the cocked position in a respective trough 141 a and 141 b by means of a respective locking slide 140 a or 140 b , which is provided with a respective aperture hole 137 a or 137 b and can be moved at right angles to the respective axis 139 a or 139 b of the respective firing pins 133 a or 133 b . The pressure of the spring 135 a or 135 b provides a secure lock. The self-defense apparatus 120 is also safe in the event of being dropped. The small weight of each locking slide 140 a and 140 b is not sufficient to cause movement in the event of the apparatus 120 striking the ground hard.
[0090] When the operating slide 124 is now pressed in the direction of the arrow 143 , then the end of the sprung arm 125 a moves in the guide groove 144 a of the switching link 123 as far as the point 145 a , and the sprung arm 125 b moves in the guide groove 144 b as far as the point 145 b . The end of the sprung arm 125 b does not in this case pass through the passage 146 . During this pushing-in movement, the sprung arm 125 a passes a projection 148 a of the locking slide 140 a , and in consequence pushes the locking slide 140 a in the direction of the arrow 147 , as a result of which the cocked firing pin 133 a strikes against the firing charge 134 a , through the aperture hole 137 a , and ignites it. The active substance is now forced out of the storage unit 121 a.
[0091] If the control slide 124 is now released, then the end of the sprung arm 125 b moves through the passage 146 and then remains at the point 149 . In the situation shown here, the control slide 124 thus does not slide back completely to its initial position. This no longer complete backward movement indicates that one storage unit has already been fired. If the control slide 124 is now pressed for a second time, then the end of the sprung arm 125 b slides along the groove 150 , in response to which the projection 148 b on the locking slide 140 b is pushed in, thus releasing the firing pin 133 b in order to ignite the firing unit 134 b.
[0092] A pot-like housing 152 a and 152 b at the end of the respective storage units 121 a and 121 b in each case holds one of the firing springs 135 a or 135 b , in each case one locking slide 140 a or 140 b , and in each case one firing charge 134 a or 134 b and the associated propellant charge 151 a or 151 b . These housings 152 a and 152 b are used as wall reinforcement in the rear area of the storage units 121 a and 121 b , where the highest pressure peaks occur during “firing”. The walls of the housings 152 a and 152 b are firmly connected to the ends of the storage units 121 a and 121 b by vibration welding.
[0093] The initiating mechanism described here is simpler than the previous initiating mechanism, which operated in a rotating manner, and can thus be produced at a lower cost.
[0094] The self-defense apparatus 120 is produced virtually completely from plastic. Only the pyrotechnic elements which hold the propellant and the firing charges 134 a / 151 a and 134 b / 151 b are composed of brass components. During assembly of the self-defense apparatus 120 , the propellant and the firing charges 134 a / 151 a and 134 b / 151 b must not be heated above 100° C. Encapsulation in the plastic is thus impossible, since this plastic is injection-molded at a higher temperature. The firing and the propellant charges 134 a / 151 a and 134 b / 151 b as well as the locking slides 140 a and 140 b together with the housings 152 a and 152 b , which hold the already cocked firing pin 133 a or 133 b , respectively, are thus not inserted until later. The plastic parts are then connected to one another in the “cold” state by means of vibration welding.
[0095] So far, self-defense apparatuses have been described in which a moving firing pin strikes a firing charge in order to ignite the propellant charge. However, a moving storage unit with a propellant filling and firing charge can also be shot at the stationary firing pin by means of spring force.
[0096] The storage units 1 a , 1 b , 91 a and 91 b may have considerably large mechanical dimensions. If water or some other fire extinguishing agent is then used as the active substance, storage units such as these can be used together with a smoke alarm or heat sensor for automatic firefighting. Portable firefighting appliances having a number of such storage units can also be produced.
[0097] A moveable sealing ring 155 , as illustrated in FIGS. 20 to 22 , can also be used as the closure element instead of the bursting disk 19 as shown in FIGS. 1, 2, 3 , 15 , 16 , 17 and 18 . In contrast to the bursting disk 19 , the closure element for releasing the filling (active substance) 15 is no longer destroyed (torn open) in this case, but is moved to a different position.
[0098] [0098]FIG. 20 shows only the front part of a storage unit 157 , which is analogous to the storage unit 1 , surrounding the nozzle area 159 . A mushroom-shaped web 160 with a cylindrical head 161 is mounted in the storage unit 157 , in front of the nozzle unit 3 on the inside. A circumferential retaining groove 163 is arranged on the head face surface, in which the sealing ring 155 is seated, forming a seal to the cylinder wall 164 of the storage unit 157 . The stem 165 of the web 160 has an interior 167 which is open to the nozzle unit 3 . The stem wall has four longitudinally running aperture openings 169 to the interior 167 . The stem length corresponds approximately to three times the diameter of the sealing ring 155 .
[0099] When ignition takes place in order to force out the filling (active substance) 15 , as already described above, a pressure is built up in the active substance 15 by the piston 21 . This pressure forces the sealing ring 155 out of its retaining groove 163 into the position shown in FIG. 21. As indicated by the arrows 170 , the active substance 15 can now flow through the free space 171 alongside the stem 165 , through the aperture openings 169 and the interior 167 , into the nozzle unit 3 . The free space 171 , the aperture openings 169 and the interior 167 now together form the nozzle entry area which is required to dissipate the pressure peaks in the active substance.
[0100] Means for deforming the piston 21 in order to completely dissipate the pressure of the propellant means, for example the pressure relief webs 27 , are not illustrated explicitly here but are also, of course, present.
[0101] As described above, the propellant charge is preferably in pyrotechnic form. However, propellant charges acting in different ways can also be used, depending on the field of application. For example, it is possible to use just a preloaded spring or a precompressed gas volume.
[0102] In the above description, the storage units form a unit. However, as is illustrated in FIGS. 23 to 26 , it is also possible to use reloadable storage units 173 . The storage unit 173 is now constructed in three parts. It has a base unit 175 with the nozzle unit which has already been described above and likewise has a nozzle entry area, and which is identified by 176 here. The nozzle unit 176 is, for example, designed analogously to the nozzle unit 3 . Furthermore, the storage unit 173 has a firing unit which is preferably in the form of a firing cap unit 177 and has a filling tank 179 for the active substance which, in this case as well, may be solid, liquid or gaseous. The firing cap unit 177 can be connected detachably, but in a robust manner, to the base unit 175 . The connection may be a screw connection, a bayonet fitting, a plug connection, . . . . However, the base unit 175 and the firing cap unit 177 are preferably integrated in a fixed manner in the defensive apparatus or self-defense apparatus. In addition to the solid, liquid or gaseous filling 180 , the filling tank 179 has a closure element 181 which can be torn open, a propellant charge 183 and a piston 184 which can be driven against the closure element 181 by the propellant gas from the ignited propellant charge 183 . The closure element 181 is part of the sleeve 189 mentioned below, and is designed analogously to the bursting disk 19 . Pressure relief webs 185 are formed in an analogous manner to the pressure relief webs 27 in the storage space end area adjacent to the closure element 181 . The piston 184 seals the filling tank 179 by means of a sealing ring 187 from the propellant charge 183 .
[0103] The geometry of the propellant charge 183 , as a pyrotechnic propellant cartridge, is designed such that the sleeve which is filled with the filling (which in this case is liquid) and is sealed by the piston 184 , preferably a metal sleeve 189 of the filling tank 179 , is pushed against it and can then be compressed in a force-fitting manner by means of rolling-in, clinching-in or in some similar way. After this connecting process, the filling tank 179 is a sealed unit, ready for use and intrinsically closed, which can be stored or carried without any problems even over a lengthy time period.
[0104] The metal sleeve 189 of the filling tank 179 preferably has thin walls. It may be deep-drawn or extrusion-molded. For economy and weight reasons, the wall thickness is preferably chosen to be sufficiently thin that it could not on its own withstand the pressures which occur when the filling is forced out. Adequate robustness is provided only with the assistance of the robustness of the wall 190 of the base unit 175 . The external diameter of the filling tank 179 is now chosen so as to ensure that pushing into a “cartridge chamber” 191 in the base unit 175 is just possible, with a small clearance tolerance. The filling tank 179 is held at the rear in the “cartridge chamber” 191 using a coupling; it could, of course, also be held at the front (at the side on the sleeve edge adjacent to the closure element 181 ). The coupling for holding purposes has as the first coupling part a step 193 which is arranged at the end of the base part 175 and which, together with the firing cap unit 177 , forms a groove in which an attachment 192 on the filling tank 179 is located as the second coupling part.
[0105] The base unit 175 and, in general, the firing cap unit 177 as well will be integrated in the self-defense apparatus. The housing can then be opened in order to insert a filling tank or filling tanks. Since the housing of the apparatus is constructed symmetrically in two parts, it can be opened, for example, on the groove 55 . | The invention relates to a defense device with a storage unit ( 1 ) that is provided with a nozzle unit ( 3 ), a solid, gaseous and/or liquid active substance stored in a storage compartment ( 5 ), a propelling charge and an igniting charge for igniting said propelling charge, in order to propel the active substance by way of a propellant that is produced when the propelling charge is ignited and to expel it from the storage compartment ( 5 ) through the nozzle unit ( 3 ) into free space. The storage device is further provided with a closing element ( 19 ) in the nozzle inlet zone, which prevents the active substance from escaping from the storage compartment ( 5 ) in the unignited state, but releases the nozzle unit ( 3 ) directly after ignition in such a way that no fragments of the closing element ( 19 ) can escape from the nozzle unit ( 3 ). A piston ( 21 ) in the storage compartment ( 5 ) can be displaced by the emerging propellant from a rest position into a final position of the piston in which it expels the active substance ( 15 ). Said piston ( 21; 87 ) interacts with a pressure-relief means ( 27, 85 ) which effects a complete pressure reduction of the propellant once the active substance ( 15 ) has been substantially completely expelled into free space. At least two of such storage devices ( 1 a , 1 b ) can be used together in a self-defense device ( 11 ). Said self-defense device ( 11 ) has a plane of symmetry ( 41 ) with respect to which the storage devices ( 1 a , 1 b ) are disposed. A trigger device that is provided with a single actuation slide ( 43 ), a so-called trigger, initiates expulsion of the active substance of only one storage device ( 1 a , 1 b ) at a time with a predetermined distribution configuration into free space. The actuation slide ( 43 ) lies in the plane of symmetry ( 41 ) so that the self-defense device ( 11 ) can be operated both by left- and by right-handed persons. | 5 |
CROSS REFERENCE TO RELATED APPLICATIONS
[0001] This application claims priority from U.S. Provisional Application Serial No. 60/294,471 filed on May 30, 2001 and entitled CT INJECTOR SYSTEM, incorporated by reference herein in its entirety.
BACKGROUND OF THE INVENTION
[0002] Computed tomography (hereinafter “CT”) is a medical procedure whereby an X-ray imaging machine is used to take cross-sectional images of a patient. The source of the X-rays is placed on one side of the body while an array of detectors is placed on the other side. The X-rays pass through the body and are read by the detectors on the other side. The signals received by the detectors are sent to a computer which compiles the data to create images. The detectors and X-ray source may be rotated around the body, while the body is being translated axially, to create a plurality of layered images.
[0003] CT differs from traditional X-ray imaging in that a computer is used to first “record” the image. Often, a contrast agent providing radiopaque contrast is injected into the patient intravenously to greatly enhance the images. Because the nature of CT is more like a continuous “movie” rather than a snapshot-like traditional X-ray, the flow and efficacy of the contrast agent may be monitored during the procedure.
[0004] Using radiopaque contrast agents for CT procedures, however, involves complications. For example, extravasation, the unintentional delivery of an injectate into the tissue surrounding the targeted vein or artery, can be a serious complication when injecting a radiopaque contrast agent during a CT procedure. These contrast agents are relatively thick solutions that are not easily absorbed by human tissue. Thus, whereas extravasation of an easily-absorbed solution, such as saline, is of relatively minor consequence, extravasation of a CT contrast agent can be a painful mishap often requiring an invasive, surgical removal procedure called a fasciotomy.
[0005] Extravasation occurs whenever the tip of the percutaneous needle is not located in the target vein and injectate is nonetheless delivered through the needle. There are various causes of extravasation. One cause involves a technician or nurse missing the lumen of the target vein, or passing completely through the vein with the needle tip, during introduction. Another cause involves the jetting force of the injectate creating a rearward, resultant force on the needle, pushing the needle out of the vein, or pushing the vein away from the needle tip until the tip is no longer in the lumen. Extravasation may also be caused by the jet force of the injectate eroding through the wall of the vessel.
[0006] Manual control of the injection flow rate by a skilled technician would effectively minimize extravasation caused by excessive jetting force. However, as previously mentioned, contrast agent continues to be injected into the vein during a CT procedure. A technician manually injecting the agent would thus be exposed to repeated, and cumulatively harmful, doses of X-ray radiation.
[0007] The need for precise control over the flow rate of CT contrast agent, along with the hazards of repeated exposure to X-ray radiation, has illuminated the need for the development of a computer controlled, automatic injector system. The applicants have developed a somewhat similar system for use in angiographic procedures. This system is described in U.S. Pat. No. 6,099,502, filed Oct. 24, 1997, and U.S. patent application Ser. No. 09/542,422, filed Apr. 4, 2000, both of which are incorporated herein by reference in their entireties.
[0008] Angiograms are similar to CT scans in that the same contrast agent is used to form an X-ray image. However, angiograms do not share many of the complications of CT scans. Angiograms involve the introduction of a long catheter into the aorta through an entry in the groin. The catheter is threaded through the aorta to the target site, such as the heart or brain, and used to deliver a larger volume of injected contrast agent in a short time. The goal is to create a slug of contrast agent that occupies substantially the entire lumen of the target site in order to form an image of the targeted vascular system. Once the agent is injected, a series of traditional X-rays are taken. If it is determined that more X-rays are needed, another slug of contrast agent is injected. Thus, extravasation is much less likely to happen as the catheter is positioned deep within the aorta and the location of the distal end is established before the agent is introduced. Further, there is sufficient time between the introduction of the agent and the taking of the X-rays for the attending physician and technicians to leave the X-ray room.
[0009] The aforementioned injector system was developed because technicians were unable to achieve the necessary injectate flow rate manually. However, this system is unsuitable for CT agent introduction. In addition to being too large, it requires the technician to be present in the X-ray room during operation.
[0010] It would be desirable to develop an automated injector system tailored to the unique needs of CT. Such a system would optimally provide remote operation, redundant safeguards against uncontrolled agent introduction, and the ability to alternate between two injectates. A need for a method of injecting a radiopaque contrast agent that reduces the risk of contrast agent extravasation is also needed.
SUMMARY OF THE INVENTION
[0011] In one aspect of the present invention, there is a method of injecting a contrast agent that minimizes the extravasation of the agent. The method involves the use of a preliminary injection of an easily absorbable liquid, such as saline, to establish the absence of extravasation.
[0012] While the preliminary injection of saline is being administered, the technician monitors the injection site by palpation for signs of extravasation. If extravasation is present, the technician repositions the needle and repeats the process of injecting saline and monitoring for signs of extravasation. Because saline is readily absorbed by the body, the extravasation of saline is much less painful and less likely to cause scarring than the extravasation of contrast. Thus, if extravasation occurs while injecting saline, a fasciotomy is typically unnecessary.
[0013] Once it is confirmed that extravasation is not present, the needle or catheter is held in place and fluidly connected to a supply of contrast agent. The contrast agent is introduced at a flow rate that may be approximately equal to that of the saline, thereby minimizing the possibility of extravasation caused by the jetting force of the injectate. Once the desired quantity of contrast agent has been administered, it is preferable to inject a second quantity of saline. Doing so flushes the introduction site of contrast agent, thereby reducing pain and preventing any inadvertent extravasation during needle extraction. Doing so also increases the patency of the contrast agent. It has been determined that providing such a saline boost following the agent allows a smaller dose of the expensive contrast agent to be used without sacrificing image quality. Additionally, this boost injection ensures that the intended dosage of contrast agent is actually delivered to the patient by flushing the remainder of the contrast bolus from the tubing connected to the percutaneous needle.
[0014] In order to present an environment in which a patient may receive a CT agent while being exposed to X-ray radiation, without the need for an attending technician, another aspect of the present invention is an automatic injector system. The system includes a remote operating panel which may be located in a radiation-free control room, adjacent to the room where the patient is located. The system generally comprises a mechanical linear actuator controlled by a computerized operating system. The linear actuator is operably connected to a plunger within a syringe to either force fluid from the syringe or draw fluid into the syringe. An operating system controlling the automatic injector system is enabled by software programs that allow a technician to input flow rates and quantities.
[0015] The linear actuator includes a plunger rod that is preferably magnetically coupled to the plunger. A magnetic coupling between the plunger rod and the plunger is advantageous over a traditional “snap fit” connection, commonly used in other automatic injector devices. This “snap fit” arrangement is found on systems wherein automatic engagement and disengagement of the plunger with the plunger rod is desirable to prevent contaminating the syringe pumping chamber and to simplify the operation of the injector system. In some situations, it is desirable to damage or destroy the connection portion of the plunger to prevent syringe reuse. As a result of the unsnapping and/or destruction of the connection, particles may remain in the connection area and cause problems during subsequent interconnections. Magnetically coupling the actuator to the plunger provides a connection which is broken cleanly and, lacking interlocking componentry, is not susceptible to clogging or other interference.
[0016] Another advantage of providing a magnetically coupled, actuator-plunger relationship is that a connection is established without requiring any connection force. One problem often encountered with automatic injectors using snap connections is that the force necessary for engagement is too high, while the force necessary for disengagement is too low. With snap connectors it may be difficult to maintain the plunger in a fixed position relative to the pumping chamber because the plunger may be driven forward during the engagement procedure. Additionally, it may be difficult to maintain the plunger in an engaged position with the plunger rod when the plunger rod is retracted. Instances where a connection is either never achieved, or not achieved until the plunger has reached the distal end of the syringe, are not uncommon. A magnetized plunger rod connects to a ferrous or magnetic plunger coupling with a zero, if not a negative, connection force.
[0017] Preferably, the magnetic connection employs rare earth neodymium iron boron magnets. Rare earth magnets are strong enough and small enough to maintain contact with the plunger while the plunger is being withdrawn to draw fluid into the syringe. A stack of such magnets may be used to increase the power of the magnetic field.
[0018] The performance of the magnetic connection is further enhanced by using an advanced plunger design with the syringe. The plunger includes a lip seal that prevents fluid within the syringe from leaking out, prevents contaminants and air from entering the syringe, and assists the gripping power of the magnets by reducing the friction between the inner walls of the syringe and the sides of the plunger. A thin ridge or lip is oriented radially outward and is angled forward from the leading edge of the side of the plunger. Upon the application of force from the injector actuator to the plunger assembly, the fluid pressure within the syringe increases. This increase in pressure forces the lip into closer contact with the internal surface of the syringe bore. The contact force between the lip and the syringe bore is directly proportional to the fluid pressure, reinforcing the seal between these surfaces with increasing pressure.
[0019] This lip seal may be used in combination with standard seal “bumps” that protrude radially around the circumference of the plunger assembly. A second lip seal, rearward of the first lip seal and angled rearward rather than forward, may be used to more effectively prevent the ingress of air into the syringe bore when the plunger is being withdrawn during a fill operation.
[0020] Notably, the existence of one or more of these lip seals greatly reduces the area of contact between the plunger and the bore compared to more conventional syringe designs. This reduction in contact area corresponds to a reduction in friction and thus enhances the performance of the magnetic connection between the plunger rod and the plunger.
[0021] Another aspect of the present invention provides an injectate delivery device that enables a technician or automated injector to easily switch between two different solutions using a common percutaneous introducer such as a needle or catheter. The device is preferably constructed and arranged for insertion into the aforementioned automatic injector system.
[0022] In one aspect of the delivery device, there are provided two separate syringes fluidly connected to the percutaneous needle or catheter with a fluid communications network. The network has one or more valves directing the fluid toward the lumen of the needle or catheter. This device reduces the possibility that the needle or catheter will be inadvertently displaced from the target vein when switching injectates.
[0023] Preferably, the device further includes connections to fluid supplies, and associated valves, such that one syringe may be filled with a liquid without affecting the operation of the other syringe. This device may be embodied using material that will result in a disposable, single-use device, or using a combination of materials such that portions of the device are reusable.
[0024] The valve network provided with the various embodiments of the injectate delivery device is constructed and arranged to automatically port a pressurized liquid to the introducing catheter. Manually actuated valves are either minimized or completely replaced, thus eliminating the potential for operator error and allowing the fluids to be alternated remotely.
[0025] Alternatively, there is provided a similar delivery device that provides only one syringe. Similar in design and construction to the two-syringe embodiment, this less expensive embodiment is ideally situated to applications where only one injectate is necessary. If necessary, this embodiment may be used to alternate injectates by switching the supply reservoir from which the device is drawing injectate.
[0026] Another aspect of the automatic injector system is a computerized operating system. The computerized operating system includes a remote operating panel located in an adjacent room, shielded from X-ray radiation. Because the present invention pertains to a computerized machine performing a medical procedure in the absence of immediate human contact, redundant safety measures are needed. A variety of safety features are thus incorporated into the present invention to preserve, or improve upon, the standards of safety exercised when contrast agents are injected manually.
[0027] The present invention includes components located in the vicinity of the patient, and remote components, located in an adjacent control room, that are used by physicians to operate and monitor components in the patient room. In addition to the components described above, the patient room also includes an injector head. As used herein, “injector head” generally refers to a computer controlling a motor connected to a linear actuator or plunger rod. As mentioned above, the linear actuator is operably attached to the plunger such that the plunger may be moved back and forth within the syringe. In the embodiment providing two syringes, the injector head preferably includes two motors and two linear actuators, controlled by the computer. Alternatively, the injector head includes one motor alternatingly engageable to two linear actuators.
[0028] The components in the control room include a monitor, such as a liquid crystal display (LCD) touch monitor, and a computer with a power supply. The computer communicates with and controls the injector head from the control room. Having introduced the basic components of the system, it is now possible to briefly summarize the basic safety features relating to the injector head of the present invention.
[0029] One aspect of the injector head of the present invention includes a watchdog computer program for ensuring all safety-critical computer programs or “tasks” that are supposed to be running during an injection operation are doing so without error. Computer-controlled, safety-critical medical devices must ensure that if the computer processor becomes inoperable for any reason, the system can be shut down in a manner that will not harm the patient or operators of the device. Electronic watchdog circuits that require the software to signal the watchdog circuit at a predetermined time interval are known. However, in a multitasking operating environment, it is possible that the task responsible for signaling the watchdog circuit remains operational while a separate task pertaining to patient safety becomes inoperable in a manner undetected by the electronic watchdog circuit. Thus, this watchdog program includes a code segment that monitors signals from each of the safety-critical tasks, either by passively receiving “operation normal” signals from the tasks, if they are so programmed to send these at predetermined intervals, or by requesting or pulling such signals from the tasks. The program also includes a code segment that verifies that such an “operation normal” signal has been received from each and every one of the designated safety-critical tasks. In other words, the program repeatedly performs a “roll call” at a predetermined interval.
[0030] This code segment, herein referred to as the “watchdog task” then sends a reset signal to a watchdog timer code segment. The watchdog timer code segment is a timer that runs continuously, beginning from zero, whenever it is reset. A shutdown code segment sends a shutdown signal to a motor shutdown logic circuit, discussed below, whenever the timer reaches a predetermined elapsed time. Thus, the watchdog computer program generates a shutdown signal unless it is verified that each of the safety tasks is operating normally during the predetermined interval.
[0031] One of the critical safety tasks monitored by the watchdog task is an interprocessor communications link task run by the microprocessors of the injector head and the remote operating panel. The two microprocessors communicate with each other via an acceptable communication link. The processors send messages to each other at predetermined intervals, verifying that they are operating normally. When it is established that the processors are operating normally, an operation normal signal is sent to the watchdog task, as described above.
[0032] Another aspect of the injector head of the present invention is a safety circuit that includes the aforementioned motor shutdown logic circuit. This safety circuit provides a degree of redundancy to the watchdog computer program. A plurality of comparators, each having a first input line, a second input line, and an output line are provided. The first input line of each comparator receives a voltage signal from a sensor measuring a selected operating parameter of the automatic injector system. Examples of such parameters include: plunger speed, plunger position, and motor torque, for both the saline and the contrast agent plungers and/or motors.
[0033] The second input line is preferably connected to a digital-to-analog converter which takes an inputted limit on one of the parameters, converts it to an analog signal, and sends it to the comparator. The comparator compares the signal from the first line to that of the second line. If the difference exceeds a predetermined threshold, the comparator sends a signal to the motor shutdown logic circuit. Thus the motor logic circuit is able to receive signals from any of the comparators and from the watchdog timer. The motor logic circuit is also connected to a relay electrically connecting the motor of the injector head to a power supply. The motor logic circuit is designed to trip the relay when it receives a signal from any of the comparators or the shutdown code segment.
[0034] Another safety feature of the injector head includes a computer program to control the flow rate created by the plunger being forced through the syringe by the motor. The computer program is embodied on a computer readable medium executable by a computer and generally comprises a velocity loop and a pressure loop. The velocity loop is a code segment capable of comparing data representative of actual plunger speed to a predetermined speed setting. The pressure loop is a code segment capable of comparing data representative of actual motor load to a predetermined motor load limit.
[0035] The velocity loop and the pressure loop work together to ensure the safe delivery of the contrast agent and/or saline to a patient. The velocity loop maintains the flow rate of the fluid within a predetermined range so that the contrast agent flow rate is high enough to be effective, but not excessive causing internal trauma, such as extravasation. The pressure loop monitors the load on the motor, becomes active at a selected setting, and prevents the load from exceeding the selected setting by a predetermined amount. Motor load is representative of pressure on the plunger. If a blockage were to occur in the fluid path, for example, the flow rate could be decreased. The velocity loop would note that the plunger speed has decreased and would send a signal to increase the motor speed. However, the presence of the blockage would result in an increased load condition on the motor, and an increase in pressure within the syringe. The pressure loop thus either shuts the system down or slows the motor speed if the motor load exceeds the selected setting by a predetermined amount. These loops are preferably software programs but may be solid state circuits or even mechanical feedback devices.
[0036] Because the automatic injector is driven by at least one microprocessor, the system must be capable of storing the data and software used for executing the application. It would be desirable to have the capability to install software after the device has been assembled. This capability facilitates ease of manufacture and allows immediate field upgrades without significant down time. Thus, it is preferable to provide the software and data storage capability on a modular memory card, such as CompactFlash™. The CompactFlash™ mass storage device is a card which can be unplugged and replaced through an access point on the injector device. Using a CompactFlash™ removable mass storage device for storing application software, calibration data, and device usage data, provides the ability to both download and retrieve the software and data from the injector using a connected computer, and to physically remove and replace the CompactFlash™ card with the data on it.
[0037] The microprocessor may be configured for connection to the Internet or an intranet, thereby allowing a physician in a remote location to program various injector parameters. Remote connectivity could also be used for manufacturer troubleshooting without requiring a technician to make an on-site service call.
BRIEF DESCRIPTION OF THE DRAWINGS
[0038] [0038]FIG. 1 is a flow chart that describes a method of preventing contrast agent extravasation of the present invention;
[0039] [0039]FIG. 2 is a perspective view of an automatic injector system of the present invention;
[0040] [0040]FIG. 3 a is a plan cutaway view of the syringes and fluid network of the present invention;
[0041] [0041]FIG. 3 b is a plan cutaway view of the catheter connector of the present invention;
[0042] [0042]FIG. 3 c is a perspective view of a preferred embodiment of the syringes and fluid network of the present invention;
[0043] [0043]FIG. 4 is a plan view of an injector head of the present invention;
[0044] [0044]FIG. 5 is an elevation view of a plunger of the present invention;
[0045] [0045]FIG. 6 is a section view of the plunger of FIG. 5 taken generally along lines 6 - 6 ;
[0046] [0046]FIG. 7 is a rear perspective view of a linear actuator assembly of the present invention;
[0047] [0047]FIG. 8 is a front perspective view of a linear actuator assembly of the present invention;
[0048] [0048]FIG. 9 is a side elevation sectional view of the linear actuator assembly of FIG. 8 taken generally along lines 9 - 9 ;
[0049] [0049]FIG. 10 is an enlarged view of the circled area bearing assembly 122 of FIG. 9;
[0050] [0050]FIG. 11 is a diagram of the basic components of the automatic injector system of the present invention;
[0051] [0051]FIG. 12 is a data flow diagram of the injector head operation of the present invention;
[0052] [0052]FIG. 13 is a flow diagram of the watchdog feature of the present invention;
[0053] [0053]FIG. 14 is a logic flow diagram of the safety circuit of the present invention;
[0054] [0054]FIG. 15 a is a perspective cutaway view of a docking plate equipped with a syringe lock assembly of the present invention;
[0055] [0055]FIG. 15 b is a perspective view of an alternative docking plate of the present invention; and,
[0056] [0056]FIG. 16 is a flow diagram of the velocity loop and pressure loop of the present invention.
DETAILED DESCRIPTION OF THE INVENTION
[0057] Method of Preventing Extravasation
[0058] [0058]FIG. 1 shows a flow diagram of the method of preventing extravasation 10 of the present invention. Beginning at 12 , an injection site is located by the attending health professional and prepared for injection at 14 using appropriate cleaning techniques. The needle or catheter is inserted at 16 to establish fluid communication between the needle or catheter and the targeted lumen of the patient.
[0059] At 18 , a supply of saline is fluidly connected to the needle or catheter and, at 20 , a quantity of saline is injected into the patient at a predetermined flow rate that may be approximately equal to the desired flow rate of the eventual contrast agent injection. It is preferred that the flow rate of the saline injection be at least as great as the planned flow rate of the contrast agent. Doing so ensures that extravasation complications caused by jetting forces will be revealed prior to the introduction of the contrast agent. While the saline is being injected, the attending professional is constantly monitoring by palpation, and visually, at 22 . If extravasation is suspected, the professional halts the injection at 24 and repositions the needle at 26 . The process then repeats back to step 20 whereby saline is injected and palpation is resumed at 22 .
[0060] If extravasation is not detected at 22 , the attending professional aligns or connects the radiopaque contrast agent to the needle or catheter at 28 . At 30 , the contrast agent is injected at the preferred flow rate. The flow rate of the contrast agent is chosen for maximum contrast effect. The flow rate of the saline is chosen based on the flow rate of the agent. While contrast agent is being injected, and imaging is occurring, the attending professional preferably leaves the patient room to minimize his or her exposure to radiation.
[0061] Upon completion of the contrast agent injection at 30 , the saline supply is again connected to the needle or catheter at 32 . At 34 , a quantity of saline is injected in order to clear the needle, flush the contrast agent away from the injection site, and increase the efficacy of the contrast agent.
[0062] Automatic Injector System
[0063] The present invention includes an automatic injector system that greatly enhances the method 10 , described above. The method 10 included two steps, 28 and 32 , where the inserted needle or catheter had to be connected to different fluids. The automatic injector system of the present invention allows this realignment to be performed remotely. The system also provides precise control over the flow rate at which the injectates are administered.
[0064] Referring now to FIG. 2, there is shown a preferred embodiment of the automatic injector system 40 of the present invention. The system 40 generally includes an injector head 42 operably attached to at least one, preferably two, syringes 44 . The syringes are attached to a fluid communications network 46 . All of the aforementioned components are located in the patient room 48 . In an adjacent control room 50 , the system 40 also includes a remote operating panel 52 . Each of these components will now be discussed in detail.
[0065] Syringes and Fluid Communication Network
[0066] The syringes 44 are connected to the patient with the fluid communication network 46 , as best shown in FIGS. 3 a - 3 c . The fluid communications network 46 is a series of valves and tubes. Syringe connector valves 54 connect the distal ends 56 of the syringes 44 to both supply tubes 58 and to cross tubes 60 . The supply tubes 58 lead to supply connectors 62 and the cross tubes 60 lead to a common shuttle valve 64 . The shuttle valve 64 is a three-way valve allowing fluid to flow from either cross tube 60 into a common tube 66 . The common tube 66 leads to a catheter connector 68 , which is designed to be attachable to a standard catheter via a port 70 . Additionally, the catheter connector may have a medicament port (not shown) that provides a site for injecting fluids other than saline and contrast agents. This medicament port may also be used as an attachment point for an air column detector.
[0067] [0067]FIG. 3 b shows the catheter connector 68 in greater detail. A coupling 69 removably couples the connector 68 to the common tube 66 . A plug 71 biased closed by a spring 73 allows fluid flow in only one direction by requiring the pressure created by the syringe 44 to overcome the force of the spring 44 .
[0068] The supply connectors 62 are attachable to containers 72 (FIG. 2), one of which preferably contains saline and the other preferably contains contrast agent. Because the two-syringe system is designed to allow an attending professional to remotely alternate between the injection of saline and a contrast agent, for ease of explanation, the components carrying saline are labeled “a”, and the components carrying contrast agent are labeled “b”, throughout the Figures.
[0069] The container 72 a , then, contains a supply of saline solution. The saline solution is loaded into the syringe 44 a by pulling the plunger 74 a away from the distal end 56 a , thereby creating a negative pressure within the syringe chamber 76 a . A close look at the syringe connector valve 54 a reveals a plug 78 a held in place against a shoulder 80 a by a biasing mechanism, preferably a spring 82 a . Alternatively, the plug 78 a is buoyant, such that the buoyancy of the plug constitutes the biasing mechanism. When the negative pressure created in the syringe chamber 76 a is sufficient to overcome the force of the spring 82 a , the plug 78 a is pulled toward the syringe 44 a , compressing the spring 82 a , and allowing the saline to flow between the plug 78 a and the shoulder 80 a and into the syringe chamber 76 a . Once the syringe 44 a is filled with a sufficient quantity of saline, the plunger 74 a is stopped, thereby causing the negative pressure created in the chamber 76 a to subside as the saline continues to fill the chamber 76 a . The spring 82 a quickly overcomes the effects of the negative pressure, and reseats the plug 78 a against the shoulder 80 a.
[0070] When the saline in the chamber 76 a is to be injected into the patient, the plunger 74 a moves toward the distal end 56 a of the syringe 44 a , creating a positive pressure in the chamber 76 a . The plug 78 a prevents the saline from reentering the supply tube 58 a . The saline instead is forced into the cross tube 60 a toward the shuttle valve 64 .
[0071] The shuttle valve 64 also uses a plug and shoulder arrangement. To accept fluid from either the saline supply tube 60 a or the contrast agent supply tube 60 b , the shuttle valve has a plug 84 a on its saline side which acts against a shoulder 86 a , and a plug 84 b on its contrast agent side which acts against a shoulder 86 b . The two plugs 84 a and 84 b are held apart by a spring 88 . The shuttle valve 64 connects the two cross tubes 60 a and 60 b to the common tube 66 . Note that the shuttle valve 64 is designed to insulate the common tube from any negative pressure forces arising in the cross tubes 60 when either of the syringes 44 are being filled.
[0072] Continuing with the saline injection explanation, when the saline is forced into the cross tube 60 a with sufficient pressure to overcome the spring 88 , the plug 84 a is displaced from the shoulder 86 a and the saline is allowed to pass around the plug 84 a . The saline, however, is blocked from passing around the other plug 84 b , which is seated, now with even greater force, against its respective shoulder 86 b . Thus the saline is forced into the common tube 66 , through the catheter connector 68 and into the patient via the needle or catheter.
[0073] The construction of the components on the contrast agent side of the fluid network 46 are virtually identical to those on the saline side, just described. The design of the syringe connector valves 54 and the shuttle valve 64 allow both syringes to be filled simultaneously and allow fluid from either syringe 44 to be injected alternately without requiring any alignment adjustments. The valves are aligned automatically based on the fluid forces in the network 46 .
[0074] The fluid network 46 preferably includes a plurality of connectors 89 (FIG. 3 c ). These connectors are placed between the various other components and allow the components to be replaced and rearranged. For example, the connectors 89 a and 89 b on either side of the shuttle valve 64 can be used to replace the shuttle valve 64 with a mixing valve (not shown) useable to mix the fluids from the two syringes 44 together. Additionally, the connector 69 can be used to disconnect the network 46 from one patient and use it on another patient without presenting sterility issues.
[0075] Injector Head
[0076] Referring to FIG. 4, the injector head 42 includes one plunger rod 90 per syringe 44 , an actuator assembly having one or more motors 110 arranged to move the plunger rods 90 , and a local control panel 94 . Each plunger rod 90 is connected to the plunger or wiper 74 of the syringe 44 . Preferably, the plunger rod 90 includes a magnet or magnetic stack 96 at its distal end that magnetically connects the plunger rod 90 to a ferrous metal insert 98 in the dry side of the plunger 74 . Using a magnetic connection between the plunger rod 90 and the plunger 74 is advantageous because it exerts no resistive force when a connection is being made. Neodymium iron boron (NIB) magnets, also known as rare earth magnets, provide sufficient strength to remain attached to the ferrous metal insert 94 when drawing a negative pressure on the syringe 44 during filling. A greater magnetic field may be obtained by using a stack of such magnets.
[0077] The performance of the connection between the magnet 96 and the ferrous metal insert 98 is enhanced by the design of the plunger 74 . FIGS. 5 and 6 show a preferred plunger 74 . The plunger 74 has a conical end 100 that substantially matches the shape of the distal end 56 of the syringe 44 . The plunger 74 also has an annular lip 102 angled forward that extends from the sidewall 104 of the plunger in both a forward and an outward direction. The lip 102 is shaped to create an inner surface 106 against which fluid pressure can act to press the lip 102 against the inner sidewall of a syringe 44 , thereby improving the seal between the syringe and the plunger. This improved seal reduces the amount of friction between the plunger 74 and the syringe 44 , thereby enhancing the performance of the connection between the magnet 96 and the ferrous metal insert 98 . Friction is further reduced by providing a rear ridge 108 . This ridge 108 also acts against the inner wall of the syringe 44 , thereby ensuring that the plunger 74 remains centered within the syringe 44 and also prevents air from seeping past the annular lip 102 when the plunger 74 is being withdrawn, such as when the syringe 44 is being filled. The ridge also prevents the entire sidewall 104 from contacting the inner wall of the syringe 44 , thus reducing the friction between the plunger 74 and the syringe 44 . It may be desired to provide a ridge 108 which has the same shape as the lip 102 , and faces rearward, to further enhance the seal between the ridge 108 and the syringe 44 when the plunger is being withdrawn.
[0078] Each of the plunger rods 90 is moved by a linear actuator assembly 92 . FIGS. 710 present detailed views of the linear actuator assemblies 92 . The assembly 92 converts rotational motion from the motor 110 into linear motion imparted to the plunger rod 90 . The motor 110 is mounted on a rear plate 112 . The shaft 114 of the motor 110 is attached to a motor gear 116 that is rotatably connectable to a plug screw gear 118 with a pulley, belt 119 , reduction gear or the like. The plug screw gear 118 is fixed to a plug screw 120 and imparts rotation thereto.
[0079] The plug screw 120 is supported by a bearing assembly 122 , the details of which are shown in FIG. 10. The bearing assembly 122 also prevents the plug screw from moving axially, relative to the rear plate 112 . On the external side 128 of the rear plate 112 , the bearing assembly 122 preferably includes a pair of angular contact bearings 124 separated by a spacer washer 126 , all held in place against the external side 128 of the rear plate 112 by a lock nut 130 and a lock nut washer 132 . On the internal side 134 of the rear plate 112 , the bearing assembly 122 includes an axial bearing 136 surrounded by two axial bearing washers 138 . One of the axial bearing washers 138 acts against the internal side 134 of the rear plate 112 while the other axial bearing washer 138 acts against a shoulder 140 of the plug screw 120 .
[0080] The plug screw 120 , thus rotates with the motor 110 . To impart linear motion to the plunger rod 90 , the plug screw 120 is threaded and carries a plug nut 142 that is attached to the plunger rod 90 . The plug nut 142 is attached to a guide flange 144 that slides along a tie rod 146 by way of a guide flange bearing 148 . The tie rod 146 prevents the plug nut 142 and guide flange 144 from rotating with the plug screw 120 , thereby forcing linear movement as the internal threads of the plug nut 142 necessarily interact with the external threads of the plug screw 120 . The tie rod 146 is preferably one of four tie rods 146 that connect the rear plate 112 to a front plate 150 .
[0081] The rearward end of the plunger rod 90 is attached to, and supported by, the plug nut 142 . Near the front plate 150 , the plunger rod 90 is supported by a linear bearing 152 that is attached to the front plate 150 . The plunger rod 90 slides through the linear bearing 152 as the rod 90 linearly advances and returns. In addition to the linear bearing 152 , the plunger rod 90 also slides through a rod wiper seal 154 , which is forward of the linear bearing 152 , and prevents dust from being picked up by the plunger rod 90 while in a forward position, from entering the housing 156 (FIG. 2) of the linear actuator assembly.
[0082] The plunger rod 90 is hollow and surrounds the plug screw 120 . The forward end of the plunger rod 90 contains the magnet or magnetic stack 96 that is secured to the end of the rod 90 with an end plug 158 . The stack is contained within a thin ferrous end cap 160 that is shaped to be received by the dry side 162 of the plunger 74 , best seen in FIG. 6. The dry side 162 of the plunger is lined with the ferrous metal insert 98 that is configured to mate with the end cap 160 .
[0083] Referring again to FIGS. 7 - 9 , it is shown that the front plate 150 is mounted to a docking plate 164 . The docking plate 164 includes two receiving grooves 166 for receiving the syringes 44 . Note the docking plate 164 is arranged to accept two linear actuator assemblies 92 .
[0084] The plunger rod 90 is sized such that when it is in the fully retracted position, as shown in FIG. 9, the forward end of the end cap is flush with the back face 168 of the receiving groove 166 . This allows a fresh syringe 44 to be slid into place prior to a procedure or midway through a procedure, if necessary. Securing the syringes 44 to the docking plate 164 by sliding them into place, instead of screwing or otherwise twisting them into place, is preferred because any twisting motion imparted to the syringe may twist the fluid communication network 46 . Locking the syringes 44 into the grooves 166 is accomplished with a syringe lock assembly 250 .
[0085] One embodiment of the syringe lock assembly 250 is best shown in FIG. 15 a . The lock assembly 250 includes two engagement members 252 pivotally attached to the docking plate 164 with pivot pins 254 . The engagement members 252 are spaced apart from the back face 168 of the docking plate 164 such that the flange 234 of the syringe 44 (FIGS. 3 a and 3 b ) is held between the engagement members 252 and the back face 168 . Preferably, the flange 234 includes a plurality of détentes 235 to add rigidity and strength to the flange 234 . The engagement members 252 are connected together with linkages 256 . The linkages 256 serve to move the engagement members 252 around the pivot pins 254 from an open position 258 to a locked position 260 . In FIG. 15, the syringe lock assembly 250 on the left is shown in the open position 258 while the syringe lock assembly 250 on the right is shown in the locked position 260 .
[0086] Looking at the syringe lock assembly 250 in the open position 258 , it can be seen that the linkages 256 fold inward, partially occluding the hole 262 in the docking plate 164 , through which the plunger rod 90 passes. When the syringe 44 is slid into the groove 166 and over the hole 168 , the flange 234 of the syringe 44 passes under the engagement members 252 and eventually contacts the linkages 256 . The flange 234 pushes the linkages upward, forcing the upper portions 264 above the pivot pins 254 apart, thus causing the lower portions 266 below the pivot pins 254 together. The engagement members 252 are shaped such that when the lower portions 266 come together, the engagement members 252 substantially surround the syringe 44 , above the flange 234 , thereby holding the syringe 44 in place. Furthermore, when fully engaged, the linkages 256 pass slightly beyond alignment with each other, thereby creating an affirming snap engagement into the locked position 260 . One or more stops 272 , attached to either the docking plate 164 or integral with the linkages 256 , prevent the linkages 256 from travelling past alignment to the extent that the linkages 256 begin to pull the upper portions 264 of the engagement members 252 together.
[0087] A release pin 268 passes through the docking plate 164 and engages the linkages 256 when the pin 268 is pressed. Depressing the pin 268 moves the linkages 256 downward, pulling the upper portions 264 of the engagement member 252 together, and forcing the lower portions 266 apart. The pin 268 also pushes the linkages 256 into the flange 234 of the syringe 44 , thereby forcing the syringe 44 out of the syringe lock assembly 250 . A biasing mechanism, such as a spring 270 , biases the pin 268 toward an inactive position, thereby preventing an accidental disengagement of the syringe 44 .
[0088] Another embodiment of a syringe locking device 251 is shown in FIGS. 2 and 4 and in detail in FIG. 15 b . The syringe locking device 251 is mounted on the same or similar docking plate 164 . It employs one catch 253 associated with each groove 166 . The catch 253 is an upwardly biased protuberance having an angled edge 255 that allows the catch 253 to be pressed downwardly when the flange 234 of the syringe 44 passes over the catch 253 . A substantially vertical edge 257 prevents the syringe 44 from retreating out of the groove 166 once the syringe 44 is fully inserted into the groove 166 and the catch 253 has snapped back into an engaged position. A release button 259 allows the operator to depress the catch 253 so that the syringe 44 may be removed.
[0089] Referring back to FIGS. 4 and 7- 9 , there is shown a linear position sensor 170 . The linear position sensor 170 includes a stationary rod 172 and a position detector 174 that rides on the guide flange 144 in close proximity to the stationary rod 172 . The position sensor 170 further includes a communications port 176 for relaying position data to the local control panel 94 . The operation of the position sensor 170 will be discussed in more detail below. Acceptable position sensors include magnetostrictive position sensors such as Temposonics® commercial sensors manufactured by MTS® Systems Corporation at Cary, N.C.
[0090] As shown diagrammatically in FIG. 11, the injector head 42 also includes a local control panel 94 . The local control panel is basically a computer 178 with an interface 180 for manipulating the software programs that control the motors 110 . A transceiver (not shown) operably connected to the computer 178 allows the injector head 42 to communicate with the remote operating panel 52 .
[0091] The injector head 42 is shown in the patient room 48 . A communications link 184 is established between the transceiver (not shown) inside the injector head 42 and the computer 178 , which is located in the control room 50 . Preferably, there is a computer 178 in both rooms. The computer 178 in the patient room 48 is considered part of the injector head 42 . The injector head 42 also receives direct current power from a power supply 186 (shown as integral with the computer 178 ) via a grounded power line 188 . A pendant 232 is also located in the patient room 48 . The pendant 232 is a tethered on/off switch attached to the local control panel 94 . The pendant 232 allows the operator to turn the system 40 on and off while verifying proper fluid flow using the method 10 .
[0092] Also located in the control room 50 is the remote operating panel 52 that establishes a communications link 190 with the computer 178 . The remote operating panel 52 preferably includes a touch monitor 190 . Both the remote operating panel 52 and the power supply 186 have power mains 192 that receive alternating current power from outlets in the control room 50 .
[0093] Injector Head Operation
[0094] The overall data flow operation of the injector head 42 is diagrammed in FIG. 12. The diagram introduces many of the safety features of the present invention. An overview explanation of FIG. 12 will be followed by a detailed analysis of these features.
[0095] Beginning with the processor 178 , it can be seen that data flows to and from the other components in the system via a peripheral component interconnect (PCI) bus interface 194 that includes memory designated to store logic and act as a buffer 196 . The computer 178 is also in electronic communication with the touch monitor 190 of the remote operating panel 52 . The computer sends the appropriate commands via the communications link 184 to the local control panel 94 (FIGS. 2 and 4).
[0096] The PCI bus interface 194 provides the interconnect for all of the various components to communicate with each other. Starting at the top of the diagram and working clockwise it can be seen that data 197 is received by the buffers 196 from the safety comparators 198 . These comparators are part of a software-based safety feature that automatically set a safety limit at a predetermined margin, e.g. on the order of 10%, above a parameter entered by the operator. The buffered data 202 that the comparators monitor originates as data 200 a and 200 b obtained from sensors on the motors 110 a (saline) and 110 b (contrast agent). Data 200 a and 200 b first undergoes digital/analog conversion and buffering at 204 . The data 200 a and 200 b includes motor torque and position and is measured or computed by sensors that will be discussed in more detail below. If the buffered data 202 exceeds 110% of the entered parameters, the safety comparator 198 may send a signal 206 that disables the power 208 to the motors by tripping the motor power relay 210 .
[0097] In addition to providing buffered analog data 202 to the safety comparators 198 , the digital/analog conversion and buffering process 204 supplies digital data 212 directly to the buffers 196 . This digital information 212 pertaining to the motors 110 is used by the computer 178 as feedback on whether the motors 110 are performing as expected. If the computer 178 determines adjustments need to be made, digital commands 214 are converted to analog signals at 204 and sent as commands 216 to the appropriate servo amplifiers 218 , which then send corrected direct current power to the motor 110 .
[0098] In addition to the sensors providing the torque and secondary position data 200 from the motors 110 , the motors also have quadrature encoders 182 (FIG. 14) providing primary position data 220 for plunger velocity control. This data 220 is also received by the processor 178 via the buffers 196 . Like the sensors, these encoders 182 will be discussed in detail below.
[0099] To prevent a computer problem, such as a single circuit failure, from adversely affecting the operation of the motors 110 , a watchdog timer 222 is provided that receives reset signals 224 from the processor 178 via the PCI bus interface 194 . The watchdog timer 222 is part of a watchdog safety feature that will be discussed individually. The timer 222 , like the comparators 198 , is able to send a motor power shutdown signal 226 to the motor power relay 210 .
[0100] Other sensors and devices 228 may also provide inputs 230 to the computer 178 via the buffers 196 . Examples of such inputs 230 include: air column alert, manifold position, travel limits, and pendant commands. An air column detector may be fashioned to the catheter connector 68 such that if an air column develops in the line leading to the catheter, the motors 110 may be stopped to prevent injecting air into the patient. Manifold position and travel limits are obtained from the linear position sensor 170 . The individual safety features and components will now be discussed. Watchdog Feature
[0101] Referring to FIG. 13, the watchdog feature 236 of the present invention is diagrammed. The watchdog feature 236 includes the aforementioned watchdog timer circuit 222 and motor power relay 210 , and also includes a watchdog task 240 that monitors a plurality of safety-critical tasks 238 . The watchdog feature 236 is a software-driven safety feature that ensures all of the software tasks 238 , deemed safety-critical, are operating normally. The safety-critical tasks 238 are those programs or subprograms that operate continuously during an injection and could adversely affect safety if they malfunction.
[0102] The watchdog task 240 is a code segment that takes “roll call”. At a predetermined interval, it determines if all of the safety-critical tasks 238 are operating normally. It preferably does this passively, requiring that each of the tasks 238 “check in”. If all of the tasks 238 report a normal operating status within the predetermined interval, the watchdog task sends a timer reset signal 224 to the watchdog timer circuit 222 resetting the timer 222 to zero. The watchdog timer circuit 222 is a timer circuit that continually runs or advances until a predetermined time is achieved. Once the predetermined time is achieved, the timer circuit sends the motor power shutdown signal 226 to the motor power relay 210 , tripping the relay 210 and cutting power to the motors 110 . As long as the watchdog task 240 sends reset signals 224 to the watchdog timer circuit 222 before the timer circuit 222 reaches the predetermined time, the timer circuit will not send the motor power shutdown signal 226 to the motor power relay 210 .
[0103] Interprocessor Communications Link
[0104] One of the safety-critical tasks 238 is an interprocessor communications link 244 (FIG. 11). The interprocessor communications link is signal sent over the communications link 184 between the processors 178 of the injector head 42 and the remote operating panel 52 . The two microprocessors 178 communicate with each other by sending pings back and forth at a predetermined interval. These pings indicate that each processor 178 is operating normally. At each interval, if normal operations have been confirmed, a corresponding signal is sent to the watchdog task 240 that the watchdog task 240 acknowledges as one of the necessary signals for a successful roll call before resetting the watchdog timer 222 .
[0105] Further safety may be provided by encoding the pings between the microprocessors 178 . Changing the code at each interval according to a predetermined schedule may prevent one of the processors 178 from sending a false positive ping.
[0106] Quadrature Encoders
[0107] The motors 110 are equipped with quadrature encoder 182 (FIG. 14). Quadrature encoder 182 are known sensors that include a stationary pickup in operable proximity to two flags, such as magnets, on a moving (in this case rotating) part. The flags are 90 degrees apart on the rotor of the motor 110 to create two sine waves or digital “square wave” pulse signals that are 90 degrees out of phase and distinguishable from each other. By monitoring the digital pulse signals, rotor speed and position can be calculated from the frequency of the pulses and the total number of the pulses, respectively. By monitoring two sets of pulses that are out of phase, rotor direction can be determined by detecting which wave is leading the other wave. Summing the number of pulses in one direction, and subtracting from the total the pulses occurring while the rotor is traveling in the opposite direction, the linear position of the plunger rod 90 can be calculated.
[0108] As noted in FIG. 12, digital quadrature encoder data 220 is generated by each motor 110 and sent to the processor 178 via the buffer 196 and PCI bus interface 194 . The processor 178 makes the calculations to determine the position and velocity of the plunger rod 90 . Notably, if a computer problem results in a loss of the flag count, rod position can no longer be calculated unless the rod 90 is moved to a zero position and the counter is reset.
[0109] Analog Data
[0110] Also introduced in FIG. 12, analog data 200 pertaining to motor torque and plunger rod position flows to the safety comparators 198 and to the processor 178 . The analog position data is obtained from the linear position sensor 170 , shown in FIG. 9 and described above. This analog position data provides safety redundancy to the digital position data generated by the processor 178 using inputs from the quadrature encoder 182 on the motors 110 . The linear position sensor 170 senses absolute position and, therefore, does not have to be reset.
[0111] The analog torque data is simply a measure of the current draw by the motors. Current draw provides an accurate indication of resistance to rotation. An increase in current draw, for any given flow rate, may be indicative of a problem such as a clog in the fluid communication network 46 , a mechanical problem within the motor 110 , or the possibility that the end of the catheter has abutted against the interior wall of the vessel into which it is inserted.
[0112] Safety Circuit
[0113] [0113]FIG. 14 shows an embodiment of the overall safety circuit 242 used by the computer 178 to prevent unsafe conditions. Limits 214 pertaining to torque and plunger rod position for both motors 110 a and 100 b are entered into the computer 178 and are stored in the buffer 196 (FIG. 12). When summoned, the limits 214 pass through the digital to analog converters 204 so they may be read by the analog comparators 198 . The comparators 198 compare actual readings for torque (current draw) and rod position (read from the linear position sensor 170 ) to the converted limits and feed digital (true/false) results to a status buffer 282 . The comparators 198 are programmed to add a predetermined percentage or constant to the inputted limit to allow for inaccuracies in the system, thereby preventing unwanted false shutdowns. The status buffer is in data flow communication with a shutdown logic program 280 , detailed below. The status buffer 282 may be the same buffer as buffer 196 .
[0114] In addition to the output from the comparators 198 , the shutdown logic program 280 receives inputs via buffer 282 from the frequency counter and magnitude comparator 284 . The frequency counter measures the encoder 182 pulse frequency by recording the amount of time between pulses (the period of the pulses). The period is inversely proportional to the frequency of the pulses and the flow rate of the injectate. The magnitude comparator detects when this frequency has exceeded a predetermined set point value. The digital output of the frequency counter 284 is stored in the status buffers 282 for use by the computer 178 to monitor the speed and positions of the plungers 74 .
[0115] The shutdown logic program 280 operates by monitoring the results from the comparators 198 and shutdown signals 226 from the watchdog timer 222 . If the shutdown logic program 280 receives a signal from any of the comparators 198 indicating that a limit has been exceeded, or a signal 226 from the watchdog timer 222 indicating that one of the safety-critical tasks has encountered an error, a trip signal is sent to the motor relay 210 , cutting power to both motors 110 .
[0116] Velocity Loop/Pressure Loop Program
[0117] [0117]FIG. 16 is a flow chart of how the computer 178 maintains the desired injectate flow rate during an injection. To maximize the efficacy of the contrast agent, an optimal volume of contrast agent must be flowing through the area of the body being imaged. Thus, a predetermined flow rate is maintained using motor speed. However, if the motor is hindered from rotation, such as due to a clog or a mechanical malfunction, the motor speed should be decreased to prevent harm to the patient or equipment. The program 286 charted in FIG. 16 maintains a desired flow rate without exceeding an upper pressure limit.
[0118] The velocity loop/pressure loop program 286 begins at 288 with the operator entering the desired injectate flow rate and upper pressure limit. At 290 the computer 178 calculates the motor speed that corresponds to the desired flow rate based on the cross-sectional area of the syringe 44 , the pitch of the plug screw 120 , and the reduction ratio of the motor gear 116 to the plug screw gear 118 . The computer also adds a tolerance around the computed motor speed to generate an acceptable velocity range, V R . The computer has preset upper absolute limits on velocity and change in velocity, V A , and torque and change in torque, T A . For simplicity, the absolute velocity limit and limit on change in velocity are both denoted as V A . The same convention is true for torque and change in torque.
[0119] Next, at 292 , the computer 178 calculates the upper torque limit T L based on the inputted upper pressure limit. The operator, when selecting the upper pressure limit, considers the viscosity of the fluid. The pressure limit should be set higher for more viscous liquids for a given flow rate. The computer 178 allows for resistance to flow due to the friction inherent in the mechanical system 40 . Torque, as discussed above, is calculated as a function of motor current draw.
[0120] At 294 the injection begins. At 296 , as a liquid is being injected, the computer 178 receives continuous velocity readings from the quadrature encoder 182 (FIG. 14) of the operating motor 110 . The computer 178 is also receiving torque data representing the current drawn by the operating motor 110 . The computer 178 is not only noting the velocity V and the torque T, but also the rate of change of velocity and torque.
[0121] At 298 , the computer 178 first checks to ensure the absolute limits on velocity and change in velocity, V A , are not exceeded. Exceeding these limits, V A , indicates a probable hardware or software failure resulting in an inability to control the motor. Thus, if V A , is exceeded, the computer sends a trip signal at 300 , which trips the motor power relay 210 .
[0122] At 302 , the computer 178 checks to ensure the absolute limits on torque and change in torque, T L , are not exceeded. If exceeded, the computer sends the trip signal 300 to the motor power relay 210 . Excessive torque and an abrupt change in torque are indicative of a clog or mechanical failure and warrant a shutdown signal.
[0123] At 304 , the computer 178 is comparing the actual torque T to the computed torque limit T L . If the actual torque T exceeds the limit, the motor speed is reduced at 306 .
[0124] At 308 , if the torque limit T L is not exceeded, the computer 178 determines whether the actual velocity V is within the acceptable velocity range, V R . If it is, the injection continues at the present motor speed and computer continues to monitor torque T and velocity V at 296 . If the velocity V is not within the acceptable velocity range V R , the computer 178 determines whether the velocity V is too high or too low at 310 . If the velocity V is too low, the motor speed is increased at 312 . If the velocity V is too high, the motor speed is decreased at 306 .
[0125] This program 286 operates independently from the circuit 242 . Thus, an overtorque situation could result in a shutdown generated by circuit 242 , or by the program 286 . However, controlling torque by decreasing motor speed is performed only by the program 286 . Importantly, the independence of these two programs, 286 and 242 , provides a degree of redundancy to the safety of the operation of the system 40 .
[0126] Modular Memory
[0127] To provide enhanced flexibility, and minimize downtime in the event of software problems, the above programs and buffers may be provided on a modular memory card 245 . Referring to FIG. 2, it can be seen that a mass storage device in the form of a modular memory card 245 , such as CompactFlash™, is provided on both the local control panel 94 and the remote operating panel 52 . The modular memory cards 245 can be unplugged and replaced through an access point on the injector device. Using these cards 245 to store application software, calibration data, and device usage data, provides the ability to both download and retrieve the software and data from the injector using a connected computer, and to physically remove and replace the cards 245 containing data.
[0128] The foregoing description addresses embodiments encompassing the principles of the present invention. The embodiments may be changed, modified and/or implemented using various types of arrangements. Those skilled in the art will readily recognize various modifications and changes that may be made to the invention without strictly following the exemplary embodiments and applications illustrated and described herein, and without departing from the scope of the invention, which is set forth in the following claims. | A method of preventing extravasation of contrast agent during a computed tomography injection. An automatic injector device facilitates ease of accomplishing the method. The method includes establishing the absence of extravasation using an absorbable injectate, such as saline, prior to injecting the contrast agent. The device includes a computerized injector head capable of switching between two injectates without physical human intervention. The device is controlled by a remote operating panel located in a control room that is protected from X-ray radiation. The device includes various software driven safety features that prevent the occurrence of unsafe conditions. | 0 |
FIELD OF THE INVENTION
[0001] The application relates generally to the manufacturing of tongue and groove profiles on wood floorboards and, more particularly, to a process for controlling the evenness of tongue and groove joints between adjacent floorboards.
BACKGROUND ART
[0002] The interlocking tongue and groove profiles along opposed longitudinal sides of hardwood floor boards, such as planks and strips, are typically made by milling. The boards are advanced on a table of a moulding machine (also known as a planning and grooving machine) between a pair of rotary cutters carrying cutting inserts or knives having cutting profiles corresponding to the profiles to be cut along the opposed sides of the boards. The relative height of the groove and tongue cutters must be precisely adjusted to ensure evenness of the boards when assembled together. Also, the position of the successive boards relative to the cutting tools must not vary from one board to another in order to provide for a smooth tongue and groove fit between the boards and ensure proper mating of the eased edges (also known as the micro-bevelled edges) of adjacent boards. If the vertical position of the boards relative to the groove and tongue cutters vary from one board to the next or if the relative vertical position of the groove and tongue cutters is not well adjusted, there will likely be a vertical offset V between the micro-bevelled edges of adjacent mating boards once assembled together, as shown in FIG. 4 b . This can also result in unevenness of the floor boards once laid down on the sub-floor.
[0003] In order to prevent the delivery of such “defective” floor boards, many floorboard manufacturers have established a quality control process at the exit of the moulding machine. Such a quality control process typically consists of manually measuring with a vernier the thickness of the top or bottom lip of the groove profile of the boards combined with a visual inspection of the evenness of the joint between two assembled sample boards. The visual inspection can be carried out by placing a level or the like on one face of two assembled boards and verifying if there is any visually perceivable gap between the assembled boards and the level. If the measured thickness is substantially the same from one board to another and the results of the visual inspection are satisfactory, it is assumed that the joining of the boards will provide even tongue and groove joints. If the thickness varies or the gap between the level and the assembled boards is considered outside of the acceptable manufacturing tolerances, then the defective floorboard production is rejected or, whenever possible, re-processed to ensure proper mating of the different board batches.
[0004] Such a quality control process has several drawbacks. First, the measurements obtained with a vernier may vary depending on the person taking the measurements. Also the visual inspection is subjective and the appreciation thereof may vary from one person to another. The results of the quality control process are, thus, greatly dependent on the skills of the operators and as such not always reliable.
[0005] Furthermore, even if the measurements are taken correctly, the thickness of the top or bottom lip of the groove profile may not be sufficient to guarantee perfect matching of the tongue and groove profiles or of the micro-bevelled edges of the boards.
[0006] There is thus a need to improve consistency in the production of tongue and groove floorboards.
SUMMARY
[0007] In view of the foregoing, it would be desirable to provide a new process by which the evenness of the tongue and groove joints between adjacent floorboards could be reliably and readily controlled.
[0008] According to a general aspect of the invention, it has been found that the precision of the quality control measurement process could be improved by using the undersurface of the floorboards as a reference surface and by measuring a depth on the groove profile and/or on the tongue profile of the boards relative to the undersurface of the boards rather than a thickness of the top or bottom lip of the groove profile. Such a depth can be measured by using a conventional depth gage, a laser or other electronic distance-measuring device. The selected measuring device or tool could, for instance, be used to measure the distance between the undersurface of a floorboard and the underside of the tongue thereof The manufacturing process could also be modified to integrate a recess or groove/undercut in the undersurface of the bottom lip of the groove profile of the boards and the depth of the undercut could be measured to evaluate the positioning of the groove profile relative to the undersurface of the floorboard.
[0009] According to a further general aspect, the depth of the undercut in the bottom lip of the groove profile can be measured with a spring-loaded plunger gage. The base of the gage is abutted against the undersurface of the board with the tip of the spring-loaded plunger abutting against the bottom of the groove or undercut. Such a measurement procedure with a depth gage has proven to be accurate and less sensitive to the skills of the person taking the measurement. The modification of the groove profile of the boards (and thus the modification of the cutting profile of the knives used to cut the groove in the boards) to incorporate the longitudinal undercut in the undersurface of the bottom lip of the groove profile allows the integration of a depth reading procedure relative to the undersurface of the board on the groove profile side thereof as part of a quality control process of the floorboard tongue and groove joints.
[0010] According to a further aspect of the present invention, a measurement can be taken not only on one side of the boards but on both sides thereof that is on the groove profile side and on the tongue profile side. The two measurements are taken from a common plane of reference, namely the undersurface of the board. These measurements allow to precisely adjusting the relative positioning of the groove and tongue cutter heads of the moulding machine in order to avoid any unacceptable mismatch or vertical offsets between the tongue and groove profiles of the floorboards when assembled together on a sub-floor structure. The measurement on the groove profile side of the board can be obtained by measuring a depth Y of the undercut defined in the bottom lip of the groove profile (i.e. the distance between the bottom surface of the undercut and the undersurface of the board). The measurement on the tongue profile side of the board can be obtained by using again the undersurface of the board as a reference plane to measure the distance X between the underside of the tongue and the undersurface of the board. The same depth measuring tool can be used to measure both the depth Y of the undercut on the groove profile side and the distance X between the undersurface of the board and the underside of the tongue on the tongue profile side of the board. If the groove and tongue cutters of the moulding machine are well adjusted, the difference between the X value and the Y value shall be equal (±the manufacturing tolerances) to the thickness Z of the bottom lip of the groove profile of the board, which is a constant fixed by the cutting profile of the groove cutter. The relative positioning of the groove and tongue cutters is adequate, when the equation: X−Y=Z is satisfied. Any deviations from constant Z provide a direct indication of the distance by which the groove cutter head and the tongue cutter head must be displaced relative to one another to avoid a vertical offset between the tongue and groove profiles of assembled floorboards.
[0011] According to a further general aspect of the present invention, the tongue and groove floorboard manufacturing process is characterized by taking measurements on both first and second longitudinal sides of a floorboard relative to a common plane of reference corresponding to an undersurface of the floorboard. A first measurement on the first longitudinal side of the floorboard is indicative of the position of the groove relative to the undersurface of the floorboard. A second measurement on the second longitudinal side of the floorboard is indicative of the position of the tongue relative to the undersurface of the floorboard. The first and second measurements are then used to adjust the position of the groove and tongue profile cutters relative to one another on the moulding machine.
[0012] According to a further general aspect of the invention, there is provided a tongue and groove floor board quality control process for the production of hardwood floorboards having interconnecting tongue and groove profiles defined along opposed longitudinal sides thereof, the process comprising: using the undersurface of the floorboards as a reference plane for taking some measurements, measuring a distance between a downwardly facing surface of at least one of said tongue and groove profiles and the undersurface of selected ones of the floorboards, and determining if the measured distance is contained within acceptable manufacturing tolerances.
[0013] According to a still further general aspect, there is provided a tongue and groove floorboard manufacturing process comprising milling interlocking tongue and groove profiles along opposed sides of incoming floorboards, the groove profile comprising a groove bounded by top and bottom lips, the bottom lip having an undercut defined therein; measuring a distance Y between the bottom of said undercut and an undersurface of selected ones of said floorboard, and determining if the measured distances fall within an acceptable range of deviations from a predetermined value.
[0014] The term “floorboard” should not be strictly construed to the preliminary meaning of the word and is intended to broadly refer to any floor planks, floor strips and the like used in the fabrication of hardwood and solid wood flooring.
[0015] The floorboard thickness is herein used to refer to the distance between the top surface and the undersurface of the boards.
BRIEF DESCRIPTION OF THE DRAWINGS
[0016] Reference will now be made to the accompanying drawings in which:
[0017] FIG. 1 is a schematic perspective view illustrating a solid wood floorboard in the process of being planed and profiled in a moulding machine according to a floorboard manufacturing process;
[0018] FIG. 2 is a schematic cross-sectional end view of a hardwood floorboard engaged between the moulding machine rotary cutters used to respectively cut the groove and tongue profiles along the opposed sides of the board while the same is being advanced through the machine shown in FIG. 1 ;
[0019] FIG. 3 illustrates a quality control inspection step of the floorboard manufacturing process, the inspection step comprising measuring with a spring-loaded plunger dial gage the depth of an undercut defined in the bottom lip of the groove profile cut in one side of the board by the rotary cutter shown on the left hand side of FIG. 2 ;
[0020] FIGS. 4 a and 4 b respectively illustrate even and uneven tongue and groove joints, the defective tongue and groove joint shown in FIG. 4 b illustrating a vertical offset between the micro-bevelled edges of two adjacent floorboards as one potential consequences of an undetected groove and tongue profiling error.
DETAILED DESCRIPTION
[0021] FIG. 1 illustrates a tongue and groove floorboard 10 in the process of being machined in a moulding machine M. Such machines typically include two or three pairs of top and bottom planer cylinders 12 , 14 and a pair of axially staggered rotary cutter heads 16 and 18 disposed for receiving therebetween the boards to be planed and profiled. The boards are advanced on a steel table 15 between the cylinders 12 , 14 and the profile cutter heads 16 and 18 . The top planer cylinders 12 planed the undersurface 20 (see FIG. 3 ) of the floorboards, whereas the bottom cylinders 14 planed what will constitute the top facing surface 22 (see FIG. 3 ) of the floorboards after final sanding and varnishing operations (not shown).
[0022] Referring to FIG. 2 , the rotary cutter head 16 carries a number of circumferentially distributed knives or cutting inserts having a cutting profile 17 configured for machining a tongue profile 24 along one longitudinal side of the board 10 . Likewise, the rotary cutter head 18 carries a number of circumferentially distributed knives having a cutting profile 19 configured for machining a corresponding groove profile 26 in the opposed longitudinal side of the board 10 . The tongue and grooves profiles 24 and 26 are configured to provide for tongue and groove interlocking engagement of adjacent floorboards 10 . In the illustrated example, both cutting profiles 17 and 19 include a slanted cutting edge portion 21 , 23 for forming eased edges or micro-bevelled edges 25 ( FIG. 3 ) at the top sides of the board 10 . The groove cutting profile 19 provided by the rotary cutter head 18 (i.e. the groove cutter head) comprises a central outwardly projecting cutting portion 28 adapted to cut a groove 30 ( FIG. 3 ) in the side of the board with a top lip 32 and a bottom lip 34 . In addition to the central outwardly projecting cutting portion 28 , the cutting profile 19 is provided at a top end thereof with an outwardly projecting cutting portion 36 for machining a groove or undercut 29 ( FIG. 3 ) in the undersurface of the groove bottom lip 34 . The groove bottom lip 34 is thus not only machined on a top side thereof but also on its bottom side. This provides for a constant thickness Z of the groove bottom lip 34 from one floorboard to another and that irrespective of possible height variations in the positioning of the boards relative to the groove cutter head 18 . However, there is still a need to ensure that the groove profiles of the boards all start at the same height from a common reference surface in order to ensure smooth tongue and groove fit and prevent vertical offsets between the eased edges of the boards when laid down side by side in interlocking engagement on a sub-floor structure.
[0023] This can be verified and controlled by referencing the profiled underside of the bottom lip 34 to the planed undersurface 20 of the boards 10 . As shown in FIG. 3 , this can be conveniently achieved by measuring the depth Y of the undercut 29 with a conventional spring-loaded plunger dial depth gage G at the exit of the boards from the moulding machine. The base B of the gage G is abutted against the undersurface 20 with the tip of the spring-loaded plunger P resting against the bottom of the undercut 29 . In the illustrated embodiment, a dial allows the operator to easily read the measured depth D of the undercut 29 . It is understood that other suitable depth gage could be used as well to measure the depth of the undercut 29 (i.e. the distance between the reference surface, namely the board undersurface 20 and the underside of the bottom lip 34 ). This measuring procedure has proven to be more precise and less sensible to human intervention. According to a further aspect, the measuring of the distance between the reference surface, (i.e. the undersurface 20 ) and the cut underside of the bottom lip 34 of the groove profile 26 could be automated and accomplished through the use of any suitable sensors, laser measuring devices or the like.
[0024] As shown in FIG. 4 a , if the measured depth D 1 , D 2 of boards 10 and 10 ′ respective undercuts 29 are substantially equal (i.e. contained within the established manufacturing tolerances), the top and bottom lips 32 and 34 will fit smoothly over the tongue 24 of board 10 with a perfect match of the micro-bevelled edges 25 , thereby providing for levelled and precise micro V joint between the boards with no vertical offset between the tongue and groove profiles of the boards when the same are laid down on an underlying sub-floor. If one board is thicker than the other, the top surface of thicker board can be readily sanded to remove the excessive thickness of material therefrom without altering the apex of the V joint and the overall interlocking tongue and groove profile of the boards 10 and 10 ′.
[0025] On the contrary if the measured undercut depths are different from one another (i.e. outside of the acceptable manufacturing tolerances) as illustrated in FIG. 4 b , where the depth D 3 is greater than the depth D 4 , then there will be a corresponding vertical offset “V” between the micro-bevelled edges and that even if the boards have the same overall thickness. If the difference between D 3 and D 4 is too important, it might even be difficult or even impossible to engage the tongue of the first board into the corresponding groove of the adjacent board when the same are laid down on the underlying sub-floor structure. The difference between D 3 and D 4 provides an indication that the position of the tongue and groove cutter heads 16 and 18 must be adjusted.
[0026] By using the depth of the undercut as the reference measurement in production instead of the thickness of the top lip of the groove profile, any variation of thickness between the floorboards can be corrected by sanding the top surface of the boards without altering the vertical match of tongue and groove profiles of the boards. By so measuring the floorboards during the production, it is possible to ensure consistency between the various production batches, thereby allowing floorboards of different batches to be assembled together in a substantially perfect co-planarity.
[0027] The relative vertical position of the tongue cutter head 16 and of the groove cutter head 18 must be well adjusted before the production of each batch of floorboards to ensure proper matching of the tongue and groove profiles of adjacent boards. This adjustment can be initially made and periodically verified by taking measurements on both the groove and tongue sides of the floorboards at their exit from the moulding machine M. For each inspected board, the board undersurface is used as a common plane of reference for the measurements taken on the two sides of the board.
[0028] As explained herein above, the measurement on the groove profile side of a floorboard can be obtained by measuring a depth Y ( FIG. 3 ) of the undercut 29 defined in the bottom lip 34 of the groove profile (i.e. the distance between the bottom surface of the undercut 29 and the undersurface 20 of the board). As shown in FIG. 3 , the measurement on the tongue profile side of the board 10 can be obtained by using again the undersurface 20 of the board as a reference plane to measure the distance X between the underside of the tongue 24 and the undersurface 20 of the board 10 . The same depth measuring tool can be used to measure both the depth Y of the undercut 29 on the groove profile side and the distance X between the undersurface 20 of the board 10 and the underside of the tongue 24 on the tongue profile side of the board. If the tongue and groove cutter heads 16 and 18 of the moulding machine M are well adjusted, the difference between the X value and the Y value shall be equal (±the manufacturing tolerances) to the thickness Z of the bottom lip 34 of the groove profile of the board 10 , Z being a constant fixed by the cutting profile 19 of the groove cutter head 18 . The relative positioning of the tongue and groove cutter heads 16 and 18 is adequate, when the equation: X−Y=Z is satisfied. Any deviations from the constant Z provide a direct indication of the distance by which the groove cutter head 18 and the tongue cutter head 16 must be displaced relative to one another to avoid a vertical offset between the tongue and groove profiles of the floorboards. This provides a very precise and rigorous method for adjusting the tongue and groove profile cutter heads 16 and 18 as compared to the prior art visual inspection of the evenness of two assembled boards.
[0029] The above description is meant to be exemplary only, and one skilled in the art will recognize that changes may be made to the embodiments described without departing from the scope of the invention disclosed. For example, it is understood that the same measuring methods could be used with floorboards having no micro-bevelled edges. Still other modifications which fall within the scope of the present invention will be apparent to those skilled in the art, in light of a review of this disclosure, and such modifications are intended to fall within the equivalents accorded to the appended claims. | The undersurface ( 22 ) of the floorboards ( 10 ) is used as a main reference for taking measurements in a tongue and groove floorboard quality control process. The process comprises measuring at least one distance (X, Y) between the undersurface ( 22 ) and a downwardly facing surface of at least one of a tongue and a groove profile of selected ones of the floorboards ( 10 ). Measurements can be taken from the undersurface ( 22 ) of the selected boards ( 10 ) on both sides thereof to vertically adjust the relative position of groove cutter head ( 18 ) and the tongue cutter head ( 16 ) of the moulding machine (M) used to manufacture the boards ( 10 ). A depth gage (G) can be used to take the measurements. | 4 |
CROSS REFERENCE TO RELATED APPLICATION
[0001] This application claims priorities from Japanese Patent Application No. 2010-171707 and Japanese Patent Application No. 2010-172318 each filed Jul. 30, 2010. The entire content of each of these priority applications is incorporated herein by reference.
TECHNICAL FIELD
[0002] The present invention relates to an inverter device and an electrical power tool.
BACKGROUND
[0003] Japanese Patent Application Publication No. 2009-219428 discloses an electrical power tool, such as, a mower provided with a motor driven with an electrical power.
SUMMARY
[0004] However, since a constant voltage is supplied to the motor in the above mower, an electrical power is wasted when the mower runs idle without mowing a lawn.
[0005] In view of the foregoing, it is an object of the invention to provide an electrical power tool capable of reducing a waste of an electrical power.
[0006] In order to attain the above and other objects, the invention provides an electrical power tool including: a motor; a load detecting unit that detects a load applied to the motor; a trigger switch that receives an instruction; and a power supplying unit that starts supplying of a driving electrical power to the motor when the trigger switch receives the instruction. The power supplying unit changes an amount of the driving electrical power based on the load detected by the load detecting unit.
[0007] Preferably, the power supplying unit determines a driving status of the motor based on the load detected by the load detecting unit, and changes the amount of the driving electrical power based on the determination.
[0008] Preferably, the power supplying unit reduces the amount of the driving electrical power when determining that the motor runs idle.
[0009] Preferably, the motor is driven with an AC electrical power. The power supplying unit includes: a controller that generates an inverter PWM signal based on the load detected by the load detecting unit; and an inverter circuit having an inverter switch element that is connected to the motor and performs an ON/OFF operation based on the inverter PWM signal to convert a DC electrical power supplied from a DC electrical power to an AC electrical power and supply the AC electrical power to the motor as the driving electrical power, the amount of the driving electrical power changing in accordance with the ON/OFF operation of the inverter switch element.
[0010] Preferably, the electrical power tool further includes a transformer switch element electrically connected to the inverter circuit. The controller generates a transformer PWM signal. The DC electrical power is supplied from a battery pack to the transformer switch element, the transformer switch element performing an ON/OFF operation based on the transformer PWM signal, the DC electrical power being converted to the AC electrical power with the ON/OFF operation of the transformer switch element and outputted to the power supplying unit. The power supplying unit further includes: a transformer that transforms the AC electrical power outputted from the transformer switch element; and a rectifying/smoothing unit that rectifies and smoothes the transformed AC electrical power. The inverter circuit converts the rectified and smoothed AC electrical power to the AC electrical power. The controller changes at least one of the inverter PWM signal and the transformer PWM signal based on the load detected by the load detecting unit.
[0011] Preferably, the controller generates an inverter PWM signal having a maximum duty and a transformer PWM signal having a maximum duty when the load detected by the load detecting unit is greater than a first threshold. The controller generates an PWM signal having a duty smaller than the maximum duty when the load detected by the load detecting unit is smaller than a second threshold smaller than the first threshold, the PWM signal including at least one of the inverter PWM signal and the transformer PWM signal.
[0012] Preferably, the power supplying unit stops supplying of the driving electrical power supplied to the motor when an overdischarge signal is inputted from the battery pack.
[0013] Preferably, the load detecting unit detects the load based on a current flowing into the motor.
[0014] Another aspect of the present invention provides an electrical power tool including: a motor; a load detecting unit that detects a load applied to the motor; a trigger switch that receives a first instruction; a power supplying unit that starts supplying of a driving electrical power to the motor when the trigger switch receives the first instruction; and a setting unit that receives a second instruction. The power supplying unit changes an amount of the driving electrical power when the setting unit receives the second instruction.
[0015] Another aspect of the present invention provides an electrical power tool including: an AC motor driven with an AC electrical power; a trigger switch that receives an instruction; an inverter circuit that converts a DC electrical power supplied from a battery pack to an AC electrical power, and supplies the AC electrical power to the AC motor; a controller configured to control the inverter circuit; and a power switch, a driving electrical power being supplied to the controller when the power switch is turned ON. The controller controls the inverter circuit to start converting the DC electrical power to the AC electrical power after the trigger switch receives the instruction.
[0016] Preferably, the electrical power tool further includes: a transformer switch element connected between the battery pack and the inverter circuit, the DC electrical power being supplied from the battery pack to the transformer switch element and converted to an AC electrical power by an ON/OFF operation of the transformer switch element; a transformer that transforms the AC electrical power outputted from the transformer switch element; a rectifying/smoothing unit that rectifies and smoothes the transformed AC electrical power, the inverter circuit converting the rectified and smoothed AC electrical power to the AC electrical power; and a transmitting unit that transmits the DC electrical power supplied from the battery pack to the controller via the AC motor when the trigger switch receives the instruction. The controller controls the inverter circuit to start converting the DC electrical power to the AC electrical power after the DC electrical power is transmitted via the AC motor.
[0017] Preferably, the power switch is disposed between the battery pack and the controller, and the transmitting unit is disposed between a connecting point between the power switch and the controller and the AC electrical motor.
[0018] Preferably, the electrical power tool further includes a trigger detecting unit having a plurality of resistors connected to the AC motor in series, the DC electrical power supplied from the battery pack being divided by the plurality of resistors and outputted to the controller. The controller controls the inverter circuit to start converting the DC electrical power to the AC electrical power after the divided DC electrical power is inputted.
[0019] Preferably, the electrical power tool further includes: a transformer switch element connected between the battery pack and the inverter circuit, the DC electrical power being supplied from the battery pack to the transformer switch element and converted to an AC electrical power by an ON/OFF operation of the transformer switch element; a transformer that transforms the AC electrical power outputted from the transformer switch element; and a rectifying/smoothing unit that rectifies and smoothes the transformed AC electrical power, the inverter circuit converting the rectified and smoothed AC electrical power to the AC electrical power. The inverter circuit includes a plurality of inverter switch elements connected between the rectifying/smoothing unit and the AC motor, the rectified and smoothed AC electrical power being converted to an AC electrical power by ON/OFF operations of the plurality of inverter switch elements. The controller controls the inverter circuit to start converting the DC electrical power to the AC electrical power after the DC electrical power is inputted via the AC motor. The controller controls one inverter switch element to turn ON and the other inverter switch element to turn OFF until the DC electrical power is inputted via the AC motor.
[0020] Preferably, the electrical power tool further includes a trigger detecting unit having a plurality of resistors connected to the AC motor in series, the DC electrical power supplied from the battery pack being divided by the plurality of resistors and outputted to the controller. The controller controls the inverter circuit to start converting the DC electrical power to the AC electrical power after the divided DC electrical power is inputted. The plurality of inverter switch includes a first switch, a second switch connected to the first switch, a third switch, and a fourth switch connected to the third switch, the first switch and the third switch being connected to a positive terminal of the battery pack, the second switch and the fourth switch being connected to a negative terminal of the battery pack, the AC motor being connected between a connecting point between the first switch and the second switch and a connecting point between the third switch and the fourth switch, the trigger detecting unit being connected to the fourth switch in parallel. The controller controls the first switch to turn ON and the second switch, the third switch, and the fourth switch to turn OFF until the DC electrical power is inputted via the AC motor.
[0021] Preferably, the electrical power tool further includes: a transformer switch element connected between the battery pack and the inverter circuit, the DC electrical power being supplied from the battery pack to the transformer switch element and converted to an AC electrical power by an ON/OFF operation of the transformer switch element; a transformer that transforms the AC electrical power outputted from the transformer switch element; and a rectifying/smoothing unit that rectifies and smoothes the transformed AC electrical power, the inverter circuit converting the rectified and smoothed AC electrical power to the AC electrical power. The controller controls the transformer switch element to start the ON/OFF operation after the trigger switch receives the instruction.
[0022] Preferably, the controller controls the inverter circuit to stop converting the DC electrical power to the AC electrical power when an overdischarge signal is inputted from the battery pack.
[0023] Another aspect of the present invention provides an inverter device including; a main body; a load detecting unit that detects a load applied to a motor which is connected to the main body; and a power supplying unit that starts supplying of a driving electrical power to the motor. The power supplying unit changes an amount of the driving electrical power based on the load detected by the load detecting unit.
[0024] Another aspect of the present invention provides an inverter device including: a main body; an inverter circuit that converts a DC electrical power supplied from a battery pack to an AC electrical power, and supplies the AC electrical power to a AC motor which is connected to the main body; a controller configured to control the inverter circuit; and a power switch, a driving electrical power being supplied to the controller when the power switch is turned ON. The controller controls the inverter circuit to start converting the DC electrical power to the AC electrical power after a trigger switch connected to the AC motor in series is operated.
BRIEF DESCRIPTION OF THE DRAWINGS
[0025] The particular features and advantages of the invention as well as other objects will become apparent from the following description taken in connection with the accompanying drawings, in which:
[0026] FIG. 1 is a side view of a mower according to a first embodiment of the present invention;
[0027] FIG. 2 is a circuit diagram of the mower according to the first embodiment;
[0028] FIG. 3 is a flowchart of a voltage control performed by a microcomputer according to the first embodiment;
[0029] FIG. 4 is an explanation diagram of the voltage control performed by the microcomputer according to the first embodiment;
[0030] FIG. 5 is a flowchart of a voltage control performed by the microcomputer according a variation of the first embodiment;
[0031] FIG. 6 is a circuit diagram of a mower according to a second embodiment of the present invention;
[0032] FIG. 7 is a flowchart of a voltage control performed by a microcomputer according to the second embodiment;
[0033] FIG. 8 is an explanation diagram of a voltage control performed by the microcomputer according to a first variation according to the second embodiment;
[0034] FIG. 9 is a flowchart of a control of a voltage control performed by the microcomputer according to a second variation according to the second embodiment;
[0035] FIG. 10 is a circuit diagram of a mower according to a third embodiment of the present invention;
[0036] FIG. 11 is a flowchart of a control of a voltage control performed by a microcomputer according to the third embodiment; and
[0037] FIG. 12 is a circuit diagram of a mower according to a fourth embodiment of the present invention.
DETAILED DESCRIPTION
[0038] A mower 1 (one example of an electrical power tool) according to a first embodiment of the present invention will be described with reference to FIGS. 1-4 .
[0039] FIG. 1 is a side view of the mower 1 . The mower 1 is provided with a main body 3 , an inverter 2 detachable from the main body 3 via a latch 2 A, and a battery pack 4 . When a trigger switch 31 is operated by a user, an electrical power is supplied from the battery pack 4 to an AC motor 32 via the inverter 2 . In the following explanation, it is assumed that the inverter 2 is connected to both the main body 3 and the battery pack 4 , though the inverter 2 is detachable from the main body 3 and the battery pack 4 . Further, a handle 5 , front wheels 6 , and rear wheels 7 for allowing the mower 1 to move are provided on the main body 3 . A lawn bag 8 for accommodating a lawn mowed by a rotating blade (not shown) connected to the AC motor 32 is detachably provided at a rear side of the main body 3 .
[0040] FIG. 2 is a circuit diagram of the mower 1 . As described above, the mower 1 includes the inverter 2 and the main body 3 . When the trigger switch 31 is operated, the inverter 2 converts a DC electrical power supplied from the battery pack 4 into an AC electrical power, and outputs the AC electrical power to the AC motor 32 of the main body 3 .
[0041] The inverter (inverter device) 2 includes a main body 2 ′ that is an outer frame. The main body 2 ′ accommodates a battery voltage detecting unit 21 , a power source 22 , a transforming unit 23 , a rectifying/smoothing circuit 24 , a transformed voltage detecting unit 25 , an inverter circuit 26 , a current detecting resistor 27 , a PWM signal outputting unit 28 , and a microcomputer 29 .
[0042] The battery voltage detecting unit 21 includes resistors 211 and 212 connected in series. The voltage supplied from the battery pack 4 is divided by the resistors 211 and 212 , and outputted to the microcomputer 29 . In the present embodiment, the battery pack 4 includes four lithium battery cells. Since each lithium battery cell has 3.6V of rated voltage, the battery pack 4 has 14.4V of rated voltage.
[0043] The power source 22 includes a power switch 221 and a voltage regulator circuit 222 connected in series between the battery pack 4 and the microcomputer 29 . The voltage regulator circuit 222 includes a three-terminal regulator 222 a and capacitors 222 b and 222 c for preventing an oscillation. When the power switch 221 is turned ON by a user, the voltage regulator circuit 222 transforms 14.4V of voltage supplied from the battery pack 4 to a predetermined voltage (for example, 5V), and outputs the predetermined voltage to the microcomputer 29 as a driving power. Note that when the power switch 221 is turned OFF, the inverter 2 is halted since the driving power is not supplied to the microcomputer 29 .
[0044] The transforming unit 23 includes a transformer 231 and an FET 232 . A primary side of the transformer 231 and the FET 232 are connected in series between the battery pack 4 and a GND. A gate of the FET 232 is connected to the microcomputer 29 . The FET 232 is turned ON/OFF in accordance with a first PWM signal (described later) outputted from the microcomputer 29 to the gate of the FET 232 . When the FET 232 is turned ON/OFF, the DC electrical power supplied from the battery pack 4 is outputted to the primary side of the transformer 231 as an AC electrical power. The AC electrical power is transformed by the transformer 231 and outputted from a secondary side of the transformer 231 .
[0045] The rectifying/smoothing circuit 24 , the transformed voltage detecting unit 25 , the inverter circuit 26 , and the current detecting resistor 27 are connected to the secondary side of the transformer 231 .
[0046] The rectifying/smoothing circuit 24 includes diodes 241 and 242 and a capacitor 243 . The AC voltage transformed by the transformer 231 is rectified by the diodes 241 and 242 , and the rectified voltage is smoothed to a DC voltage (for example, 141V) by the capacitor 243 .
[0047] The transformed voltage detecting unit 25 includes resistors 252 and 252 connected in series. The DC voltage outputted from the rectifying/smoothing circuit 24 is divided by the resistors 211 and 222 , and outputted to the microcomputer 29 .
[0048] The inverter circuit 26 includes four FETs 261 - 264 . The FETs 261 and 262 connected in series and the FETs 263 and 264 connected in series are connected to an output terminal A of the rectifying/smoothing circuit 24 in parallel. Specifically, a drain of the FET 261 is connected to the output terminal A, and a source of the FET 261 is connected to a drain of the FET 262 . In a similar manner, a drain of the FET 263 is connected to the output terminal A, and a source of the FET 263 is connected to a drain of the FET 264 .
[0049] The source of the FET 261 and the drain of the FET 262 are connected to a first terminal 32 a of the AC motor 32 of the main body 3 via the trigger switch 31 . The source of the FET 263 and the drain of the FET 264 are connected to a second terminal 32 b of the AC motor 32 . Gates of the FETs 261 - 264 are connected to the PWM signal outputting unit 28 . The FETs 261 - 264 are turned ON/OFF in accordance with second PWM signals (described later) outputted from the PWM signal outputting unit 28 . When the FETs 261 - 264 are turned ON/OFF, the DC electrical power outputted from the rectifying/smoothing circuit 24 is outputted to the AC motor 32 of the main body 3 as an AC power.
[0050] The current detecting resistor 27 is connected between sources of the FETs 262 and 264 and the GND. A high-voltage side terminal of the current detecting resistor 27 is also connected to the microcomputer 29 . With this construction, the current flowing into the current detecting resistor 27 , that is, the current flowing into the AC motor 32 is outputted to the microcomputer 29 as a voltage.
[0051] The microcomputer 29 controls the ON/OFF operation of the FET 232 based on the transformed voltage detected by the transformed voltage detecting unit 25 , so that an AC voltage having a target effective voltage is outputted from the transformer 231 . Specifically, the microcomputer 29 generates a first PWM signal based on the transformed voltage detected by the transformed voltage detecting unit 25 , and outputs the first PWM signal to the gate of the FET 232 to turn ON/OFF the FET 232 .
[0052] Further, the microcomputer 29 controls the ON/OFF operations of the FETs 261 - 264 based on the current flowing into the AC motor 32 detected by the current detecting resistor 27 , that is, based on the load applied to the AC motor 32 , so that an AC voltage suitable to the load is outputted from the inverter circuit 26 . Specifically, the microcomputer 29 generates second PWM signals based on the current (load) detected by the current detecting resistor 27 , and outputs the second PWM signals via the PWM signal outputting unit 28 to the gates of the FETs 261 - 264 to turn ON/OFF the FETs 261 - 264 .
[0053] In the present embodiment, when the current (load) detected by the current detecting resistor 27 is equal to or greater than a predetermined value, the microcomputer 29 determines that the main body 3 mows a lawn, and alternately turns ON a set of the FETs 261 and 264 (hereinafter called “first set”) and a set of the FETs 262 and 263 (hereinafter called “second set”) at 100% of duty by second PWM signals. Thus, since a greater voltage is supplied to the AC motor 32 when the main body 3 mows a lawn, it becomes possible to effectively mow a lawn.
[0054] On the other hands, when the current (load) detected by the current detecting resistor 27 is smaller than a predetermined value, the microcomputer 29 determines that the main body 3 runs idle, and alternatively turns ON the first set and the second set at a duty (for example, 40%) lower than 100% by second PWM signals. Thus, since a smaller voltage is supplied to the AC motor 32 when the main body 3 runs idle, it becomes possible to reduce a waste of an electrical power.
[0055] Further, the microcomputer 29 determines an occurrence of an overdischarge in the battery pack 4 based on the battery voltage detected by the battery voltage detecting unit 21 . Specifically, when the battery voltage detected by the voltage detecting unit 21 is equal to or smaller than a first overdischarge threshold, the microcomputer 29 determines that an overdischarge is occurring in the battery pack 4 , and stops the ON/OFF operation of the FET 232 by a first PWM signal and the ON/OFF operations of the FET 261 - 264 by second PWM signals.
[0056] Further, the battery pack 4 includes a protecting IC or a microcomputer (not shown) that have an overdischarge detecting function. The protecting IC or the microcomputer outputs an overdischarge signal to the microcomputer 29 via a LD terminal, when the battery voltage is equal to or smaller than a second overdischarge threshold larger than the first overdischarge threshold. When also receiving the overdischarge signal, the microcomputer 29 stops the ON/OFF operation of the FET 232 by a first PWM signal and the ON/OFF operations of the FET 261 - 264 by second PWM signals. With this construction, the life of the battery pack 4 is prevented from being shorten. The protection IC or the microcomputer outputs an overdischarge signal to the microcomputer 29 via the LD terminal, when the at least one cell voltage of the battery pack 4 is equal to or smaller than a third overdischarge threshold of the cell.
[0057] Next, a voltage control performed by the microcomputer 29 will be described with reference to FIG. 3 .
[0058] A flowchart shown in FIG. 3 starts when the power switch 221 is turned ON in a state where the battery pack 4 has been connected to the inverter 2 , or when the battery pack 4 is connected to the inverter 2 in a state where the power switch 221 has been turned ON.
[0059] First, the microcomputer 29 determines whether or not the trigger switch 31 has been turned ON (S 101 ). When the trigger switch 31 has been turned ON (S 101 : YES), the microcomputer 29 starts the ON/OFF operation of the FET 232 , that is, the transforming operation of the transformer 231 by a first PWM signal (S 102 ).
[0060] Next, the microcomputer 29 determines, based on the transformed voltage detected by the transformed voltage detecting unit 25 , whether or not the transformed voltage is greater than a target voltage (for example, 141V) (S 103 ). When the transformed voltage is greater than the target voltage (S 103 : YES), the microcomputer 29 reduces the duty of the first PWM signal (S 104 ). On the other hands, when the transformed voltage is smaller than the target voltage (S 103 : NO), the microcomputer 29 increases the duty of the first PWM signal (S 105 ).
[0061] Next, the microcomputer 29 sets the duty of second PWM signals to 40% to supply an AC voltage having 40V of effective voltage to the AC motor 32 (S 106 ). As described later, in the present embodiment, the duty of second PWM signals is set to one of 40% and 100%.
[0062] Next, the microcomputer 29 determines which of 40% and 100% the duty of the second PWM signals is set to (S 107 ). When the duty is set to 40% (S 107 : 40%), the microcomputer 29 determines whether or not the current (load) detected by the current detecting resistor 27 is greater than a first threshold (S 108 ). When the current (load) is greater than the first threshold (S 108 : YES), the microcomputer 29 determines that the main body 3 mows a lawn, and changes the duty of the second PWM signals to 100% to supply an AC voltage having 100V to the AC motor 32 as shown in FIG. 4 (S 109 ), and goes to S 112 . On the other hands, when the current (load) is equal to or smaller than the first threshold (S 108 : NO), the microcomputer 29 determines that the main body 3 runs idle, or the load applied to the AC motor 32 is small although the main body 3 mows a lawn, and goes to S 112 without going to S 109 .
[0063] On the other hands, when the duty is set to 100% (S 107 : 100%), the microcomputer 29 determines whether or not the current (lead) detected by the current detecting resistor 27 is smaller than a second threshold smaller than the first threshold (S 110 ). When the current (load) is smaller than the second threshold (S 110 : YES), the microcomputer 29 determines that the main body 3 runs idle, and changes the duty of the second PWM signals to 40% to supply an AC voltage having 40V to the AC motor 32 (S 111 ), and goes to S 112 . On the other hands, when the current (load) is equal to or greater than the second threshold (S 110 : NO), the microcomputer 29 determines that the main body 3 mows a lawn, and goes to S 112 without going to S 111 .
[0064] Next, the microcomputer 29 determines whether or not the battery voltage detected by the battery voltage detecting unit 21 is smaller than the first overdischarge voltage (S 112 ). When the battery voltage detected by the battery voltage detecting unit 21 is smaller than the overdischarge voltage (S 112 : YES), the microcomputer 29 determines that an overdischarge is occurring in the battery pack 4 , and stops the ON/OFF operation of the FET 232 by a first PWM signal and the ON/OFF operations of the FETs 261 - 264 by second PWM signals to stop the operations of the transforming unit 23 and the inverter circuit 26 (S 113 ). As the result, the power supply to the AC motor 32 is stopped.
[0065] When the battery voltage detected by the battery voltage detecting unit 21 is equal to or greater than the overdischarge voltage (S 112 : NO), the microcomputer 29 determines whether or not the overdischarge signal has been inputted from the battery pack 4 (S 114 ). When the overdischarge signal has been inputted from the battery pack 4 (S 114 : YES), the microcomputer 29 stops the ON/OFF operation of the FET 232 by a first PWM signal and the ON/OFF operations of the FETs 261 - 264 by second PWM signals to stop the operations of the transforming unit 23 and the inverter circuit 26 (S 113 ). On the other hands, when the overdischarge signal has not been inputted from the battery pack 4 (S 114 : NO), the microcomputer 29 returns to S 107 to continue a voltage control based on the current (load).
[0066] Thus, in the present embodiment, since the occurrence of the overdischarge in the battery pack 4 is detected by both the battery pack 4 and the inverter 2 , it becomes possible to reliably prevent the occurrence of the overdischarge.
[0067] As described above, the mower 1 according to the present embodiment changes the driving power supplied to the AC motor 32 based on the load applied to the AC motor 32 . Specifically, the mower 1 increases the driving power when the load applied to the AC motor 32 is equal to or greater than a predetermined value, and decreases the driving power when the load applied to the AC motor 32 is smaller than a predetermined value. With this construction, it becomes possible to reduce the waste of the electrical power when the mower 1 runs idle.
[0068] Note that the driving power supplied to the AC motor 32 may be changed by changing the duty of first PWM signals without changing the duty of second PWM signal. Further, the driving power supplied to the AC motor 32 may be changed by changing both the duty of first PWM signal and the duty of second PWM signals.
[0069] In this case, as shown in FIG. 5 , the microcomputer 29 controls the FET 232 with the first PWM signal so that the transformed voltage approaches the first target voltage in S 203 -S 205 , and sets the duty of the second PWM signals to 40% in S 206 . Then, when the duty of the second PWM signals is set to 40% (S 207 : 40%) and the current (load) is greater than the first threshold (S 208 : YES), the microcomputer 29 determines which of the first target voltage and a second target voltage greater than the first target voltage the duty of the first PWM signal is set to a value for (S 208 a ). When the duty of first PWM signal is set to a value for the first target voltage (S 208 a : first target voltage), the microcomputer 29 increases the duty of the first PWM signal to a value for the second target voltage (S 208 b ) and also increases the duty of the second PWM signals to 100% (S 209 ). Thus, the driving power supplied to the AC motor 32 is increased by increasing both the duty of first PWM signal and the duty of second PWM signals. On the other hands, when the duty of first PWM signal is set to a value for the second target voltage (S 208 a : second target voltage), the microcomputer 29 goes to S 209 .
[0070] On the other hands, when the duty of the second PWM signals is set to 100% (S 207 : 100%) and the current (load) is smaller than the second threshold (S 210 : YES), the microcomputer 29 determines which of the first target voltage and a second target voltage greater than the first target voltage the duty of the first PWM signal is set to a value for (S 210 a ). When the duty of the first PWM signal is set to a value for the second target voltage (S 210 a : second target voltage), the microcomputer 29 decreases the duty of the first PWM signal to a value for the first target voltage (S 210 b ) and also decreases the duty of the second PWM signals to 40% (S 211 ). Thus, the driving power supplied to the AC motor 32 is decreased by decreasing both the duty of first PWM signal and the duty of second PWM signals. On the other hands, when the duty of first PWM signal is set to a value for the first target voltage (S 210 a : first target voltage), the microcomputer 29 goes to S 211 .
[0071] With this construction, it becomes possible to not only reduce a waste of an electrical power but also suppresses the heat generated in the FETs 232 and 261 - 264 , when the mower 1 runs idle, or the load applied to the AC motor 32 is small although the mower 1 mows a lawn.
[0072] Next, a mower 1 according to a second embodiment of the present invention will be described with reference to FIGS. 6 and 7 .
[0073] In the second embodiment, the driving power supplied to the AC motor 32 can be manually changed, although the driving power supplied to the AC motor 32 is automatically changed based on the load applied to the AC motor 32 in the first embodiment.
[0074] FIG. 6 is a circuit diagram of the mower 1 according to the second embodiment. In FIG. 6 , like parts and components as FIG. 2 are designated by the same reference numerals, and the description is omitted.
[0075] The mower 1 according to the second embodiment is provided with an energy-saving switch 201 and a resistor 202 , while being not provided with the current detecting resistor 27 . The main body 3 is driven at an energy-saving mode when the energy-saving switch 201 is turned ON.
[0076] The energy-saving switch 201 and the resistor 202 are connected in series between the three-terminal regulator 222 a and GND so that the resistor 202 is directly connected to the three-terminal regulator 222 a . The connecting point between the resistor 202 and the energy-saving switch 201 is connected to the microcomputer 29 . With this construction, when the energy-saving switch 201 is turned ON (energy-saving mode), 0V (Low) is inputted to an input port B of the microcomputer 29 . On the other hands, when the energy-saving switch 201 is turned OFF, a predetermined DC voltage outputted from the three-terminal regulator 222 a is inputted to the input port B of the microcomputer 29 .
[0077] When the energy-saving switch 201 is turned OFF, the microcomputer 29 alternately turns ON the first set and the second set at 100% of duty by second PWM signals. On the other hands, the energy-saving switch 201 is turned ON, the microcomputer 29 alternately turns ON the first set and the second set at 70% of duty by second PWM signals. With this construction, a user can change the driving power supplied to the AC motor 32 in accordance with the user's wish. Therefore, for example, if the user turns ON the energy-saving switch 201 when mowing a little lawn, it becomes possible to reduce the waste of the electrical power.
[0078] Next, a voltage control performed by the microcomputer 29 will be described with reference to FIG. 7 . The descriptions of S 301 -S 305 and S 309 -S 311 are omitted, since the operations in S 301 -S 305 and S 309 -S 311 are identical with the operations in S 101 -S 105 and S 112 -S 114 in FIG. 3 , respectively.
[0079] In the second embodiment, in S 306 , the microcomputer 29 determines whether or not the energy-saving switch 201 has been turned ON (S 306 ). When the energy-saving switch 201 has been turned ON (S 306 : YES), the microcomputer 29 sets the duty of the second PWM signals to 70% (S 307 ). On the other hands, when the energy-saving switch 201 has not been turned ON (S 306 : NO), the microcomputer 29 sets the duty of the second PWM signals to 100% (S 308 ).
[0080] As described above, since the mower 1 according to the second embodiment is provided with the energy-saving switch 201 , a user can change the driving power supplied to the AC motor 32 in accordance with the user's wish. Therefore, for example, if the user turns ON the energy-saving switch 201 when mowing a little lawn, it becomes possible to reduce the waste of the electrical power.
[0081] Note that a variable resistor having a dial may be disposed instead of the energy-saving switch 201 . In this case, as show in FIG. 8 , the driving power can be changed at non-step form by changing the resistance value of the variable resistor with the dial.
[0082] Further, in the second embodiment, the microcomputer 29 decreases the driving power supplied to the AC motor 32 by decreasing the duty of the FETs 261 - 264 , when the energy-saving switch 201 is turned ON. However, the microcomputer 29 may decrease the driving power supplied to the AC motor 32 by decreasing the duty of the FET 232 when the energy-saving switch 201 is turned ON.
[0083] In this case, as shown in FIG. 9 , the microcomputer 29 controls the FET 232 with the first PWM signal so that the transformed voltage approaches the first target voltage in S 403 -S 405 . Then, when the energy-saving switch 201 is turned ON (S 406 : YES), the microcomputer 29 decreases the duty of the first PWM signal so that a third target voltage smaller than the first target voltage is outputted from the transforming unit 23 (S 406 a ), and sets the duty of the second PWM signals to 70% (S 407 ). On the other hand, When the energy-saving switch 201 is turned OFF (S 406 : NO), the microcomputer 29 increases the duty of the first PWM signal so that the second target voltage greater than the first voltage is outputted from the transforming unit 23 (S 406 b ), and sets the duty of the second PWM signals to 100% (S 408 ).
[0084] With this construction, it becomes possible to not only reduce a waste of an electrical power but also suppresses the heat generated in the FETs 232 and 261 - 264 .
[0085] Next, a mower 1 according to a third embodiment of the present invention will be described with reference to FIGS. 10 and 11 .
[0086] FIG. 10 is a circuit diagram of the mower 1 according to the third embodiment. In FIG. 10 , like parts and components as FIG. 2 are designated by the same reference numerals, and the description is omitted.
[0087] In the first embodiment, when the power switch 221 is turned ON, the battery voltage of the battery pack 4 is supplied to the microcomputer 29 via the power source 22 even if the trigger switch 31 is turned OFF. As the result, an electrical power is wasted. In the third embodiment, the mower 1 is provided with a power switch detecting diode 10 and a trigger detecting unit 11 in order to reduce a waste of an electrical power when the trigger switch is turned OFF.
[0088] An anode of the power switch detecting diode 10 is connected to a low-voltage side of the power switch 221 , and a cathode of the power switch detecting diode 10 is connected to the first terminal 32 a of the AC motor 32 via the trigger switch 31 . With this construction, when the power switch 221 is turned ON, the battery voltage of the battery pack 4 is applied to the AC motor 32 .
[0089] The cathode of the power switch detecting diode 10 is also connected to the source of the FET 261 . Therefore, when the FET 261 is turned ON, the DC voltage outputted from the rectifying/smoothing circuit 24 is applied to the AC motor 32 .
[0090] The trigger detecting unit 11 includes resistors 111 and 112 connected in series between the second terminal 32 b of the AC motor 23 and the GND, in other words, between the drain and the source of the FET 264 . When both the power switch 221 and the trigger switch 31 are turned ON, the battery voltage of the battery pack 4 is applied to the trigger detecting unit 11 through the power switch 221 , the power switch detecting diode 10 , the trigger switch 31 , and the AC motor 32 . The battery voltage of the battery pack 4 is divided by the resistors 111 and 112 , and outputted to the microcomputer 29 as a trigger detecting signal.
[0091] Note that the cathode of the power switch detecting diode 10 may be connected to the source of the FET 263 , and the trigger detecting unit 11 may be connected between the drain and the source of the FET 262 .
[0092] In the present embodiment, when the trigger switch 31 is turned OFF, that is, the trigger detecting signal is not inputted from the trigger detecting unit 11 into the microcomputer 29 , the microcomputer 29 stops the ON/OFF operations of the FETs 232 and 261 - 264 by a first PWM signal and second PWM signals. With this construction, it becomes possible to reduce a waste of an electrical power when the trigger switch is turned OFF.
[0093] Next, a voltage control performed by the microcomputer 29 will be described with reference to FIG. 11 .
[0094] A flowchart shown in FIG. 11 starts when the power switch 221 is turned ON in a state where the battery pack 4 has been connected to the inverter 2 , or when the battery pack 4 is connected to the inverter 2 in a state where the power switch 221 has been turned ON. When the power switch 221 is turned ON and the battery pack 4 is connected to the inverter 2 , a driving power is generated by the voltage regulator circuit 222 , and the drive of the microcomputer 29 is started with the driving power.
[0095] First, the microcomputer 29 determines whether or not the trigger detecting signal is inputted from the trigger detecting unit 11 , that is, the battery voltage of the battery pack 4 is applied to the trigger detecting unit 11 through the power switch 221 , the power switch detecting diode 10 , the trigger switch 31 , and the AC motor 32 (S 501 ). When the trigger detecting signal is inputted from the trigger detecting unit 11 (S 501 : YES), the microcomputer 29 determines that the trigger switch 31 is turned ON and starts the ON/OFF operation of the FET 232 , that is, the transforming operation of the transformer 231 by a first PWM signal (S 502 ).
[0096] Next, the microcomputer 29 determines, based on the transformed voltage detected by the transformed voltage detecting unit 25 , whether or not the transformed voltage is greater than a target voltage (for example, 141V) (S 503 ). When the transformed voltage is greater than the target voltage (S 503 : YES), the microcomputer 29 reduces the duty of the first PWM signal (S 504 ). On the other hands, when the transformed voltage is smaller than the target voltage (S 503 : NO), the microcomputer 29 increases the duty of the first PWM signal (S 505 ). Thus, the supply of the AC voltage to the AC motor 32 starts.
[0097] Next, the microcomputer 29 determines whether or not the battery voltage detected by the battery voltage detecting unit 21 is smaller than the first overdischarge voltage (S 506 ). When the battery voltage detected by the battery voltage detecting unit 21 is smaller than the overdischarge voltage (S 506 : YES), the microcomputer 29 stops the ON/OFF operation of the FET 232 by a first PWM signal and the ON/OFF operations of the FETs 261 - 264 by second PWM signals to stop the operations of the transforming unit 23 and the inverter circuit 26 (S 507 ). As the result, the power supply to the AC motor 32 is stopped.
[0098] When the battery voltage detected by the battery voltage detecting unit 21 is equal to or greater than the overdischarge voltage (S 506 : NO), the microcomputer 29 determines whether or not the overdischarge signal has been inputted from the battery pack 4 (S 508 ). When the overdischarge signal has been inputted from the battery pack 4 (S 508 : YES), the microcomputer 29 stops the ON/OFF operation of the FET 232 by a first PWM signal and the ON/OFF operations of the FETs 261 - 264 by second PWM signals (S 507 ).
[0099] On the other hands, when the overdischarge signal has not been inputted from the battery pack 4 (S 508 : NO), the microcomputer 29 determines whether or not the trigger detecting signal is inputted from the trigger detecting unit 11 again (S 509 ). When the trigger signal is inputted from the trigger detecting unit 11 (S 509 : YES), the microcomputer 29 returns to S 502 . On the other hands, when the trigger signal is not inputted from the trigger detecting unit 11 (S 509 : NO), the microcomputer 29 stops the ON/OFF operation of the FET 232 by a first PWM signal and the ON/OFF operations of the FETs 261 - 264 by second PWM signals (S 510 ), and returns to S 501 .
[0100] As described above, in the present embodiment, when the trigger switch 31 is turned OFF, the microcomputer 29 stops the ON/OFF operations of the FETs 232 and 261 - 264 . Thus, it becomes possible to reduce a waste of an electrical power. Further, since the ON/OFF operations of the FETs 232 and 261 - 264 is stopped when the trigger switch 31 is turned OFF, the heat is prevented from being generated in the FETs 232 and 261 - 264 , thereby the break of the FETs 232 and 261 - 264 being prevented.
[0101] Next, a mower 1 according to a fourth embodiment of the present invention will be described with reference to FIG. 12 .
[0102] FIG. 12 is a circuit diagram of the mower 1 according to the fourth embodiment. In FIG. 12 , like parts and components as FIG. 10 are designated by the same reference numerals, and the description is omitted.
[0103] The mower 1 according to the fourth embodiment is not provided with the power switch detecting diode 10 . In the present embodiment, when the power switch 221 is turned ON in a state where the trigger switch 31 is turned OFF, the microcomputer 29 starts the ON/OFF operation of the FET 232 by a first PWM signal. However, with respect to the FETs 261 - 264 , the microcomputer 29 turns ON only the FET 261 by second PWM signals. With this construction, when the trigger switch 31 is turned ON, the DC voltage outputted from the rectifying/smoothing unit 24 is applied to the trigger detecting unit 11 through the FET 261 , the trigger switch 31 , and the AC motor 32 , and divided by the resistors 111 and 112 , and outputted to the microcomputer 29 as the trigger detecting signal. Further, in the present embodiment, when the trigger detecting signal is inputted from the trigger detecting unit 11 into the microcomputer 29 , the microcomputer 29 starts the ON/OFF operations of all of the FETs 261 - 264 .
[0104] As described above, in the present embodiment, when the trigger switch 31 is not turned ON, the microcomputer 29 stops the ON/OFF operations of the FETs 261 - 264 . Thus, it becomes possible to reduce a waste of an electrical power. Further, since the ON/OFF operations of the FETs 261 - 264 is stopped when the trigger switch 31 is not turned ON, the heat is prevented from being generated in the FETs 261 - 264 , thereby the break of the FETs 261 - 264 being prevented.
[0105] Note that the trigger detecting unit 11 may be disposed between the drain and the source of the FET 262 . In this case, when the power switch 221 is turned ON in a state where the trigger switch 31 is turned OFF, the microcomputer 29 turns ON only the FET 263 instead of the FET 261 .
[0106] Further, the microcomputer 29 reduces the duty of the first PWM signal when the trigger switch 31 is not turned ON than when the trigger switch 31 is turned ON. With this construction, it becomes possible to more effectively reduce a waste of an electrical power when the trigger switch 31 is not turned ON. However, by the first PWM signal whose duty is reduced, a voltage such the microcomputer 29 can determine that the trigger switch 31 has been turned ON must applied to the trigger detecting unit 11 .
[0107] While the invention has been described in detail with reference to the embodiments thereof, it would be apparent to those skilled in the art that various changes and modifications may be made therein without departing from the spirit of the invention.
[0108] For example, the inverter 2 may be incorporated into the main body 3 , although the inverter 2 is detachable from the main body 3 in the above embodiments. In this case, the circuits provided in the inverter 2 in the above embodiments are provided in the main body 3 . Therefore, the manufacturing cost is greatly reduced by using the AC motor in a similar as the conventional AC mower.
[0109] Further, the microcomputer 29 may stop one of the FET 232 and FETs 261 - 264 in order to stop the power supply to the AC motor 32 .
[0110] Further, a DC motor may be used instead of the AC motor 32 . In this case, the voltage is adjusted before supplied to the DC motor.
[0111] Further, the mower 1 may be provided with another FET connected to the power switch 221 in series, and the battery pack 4 may be outputs the overdischarge signal to the gate of the FET when detecting the occurrence of the overdischarge. Thus, the life of the battery pack 4 is reliably prevented from being shorten, since the power supply to the microcomputer 29 is also stopped when the occurrence of the overdischarge is detected.
[0112] Further, at least one of the inverter 2 and the battery pack 4 may be provided with an alarm unit, such as, a display or a buzzer, that informing a user of the occurrence of the overdischarge, and stop the power supply to the microcomputer 29 after informing the user of the occurrence of the overdischarge. With this construction, the life of the battery pack 4 is prevented from being shorten without giving the user a feeling of strangeness.
[0113] Further, the second overdischarge threshold in the battery pack 4 may be set to a value smaller than the first overdischarge threshold in the inverter 2 , although the first overdischarge threshold is set to a value smaller than the second overdischarge threshold in the above embodiments. In this case, S 112 and S 114 of FIG. 3 , S 212 and S 214 of FIG. 5 , S 309 and S 311 of FIG. 7 , S 409 and S 411 of FIG. 9 , and S 506 and S 508 of FIG. 11 are performed in a reverse order. Further, the occurrence of the overcurrent may be also detected by both the battery pack 4 and the inverter 2 .
[0114] Further, the electrical power tool of the present invention is not limited to the mower. The present invention can be applied to an electrical power tool including a trigger switch and driven with an AC electrical power such as a hedge trimmer, a circular saw, a jigsaw, a grinder, and a driver.
[0115] Further, a plurality of battery pack 4 may be mounted on the main body 4 , and be used sequentially. With this construction, it becomes possible to use the mower 1 for a long time.
[0116] Further, the control of the transformed voltage performed in S 102 -S 105 of FIG. 3 , S 202 -S 205 of FIG. 5 , S 302 -S 305 of FIG. 7 , S 402 -S 405 of FIG. 9 , and S 502 -S 505 of FIG. 11 and the detection of the occurrence of the overdischarge performed in S 112 -S 114 of FIG. 3 , S 212 -S 214 of FIG. 5 , S 309 -S 311 of FIG. 7 , S 409 -S 411 of FIG. 9 , and S 506 -S 508 of FIG. 11 can be performed in any step in the flowcharts and can be performed at a same time.
[0117] Further, the duty is not limited to a value described in the above embodiments. | An electrical power tool includes a motor, a load detecting unit, a trigger switch, and a power supplying unit. The load detecting unit detects a load applied to the motor. The trigger switch receives an instruction. The power supplying unit starts supplying of a driving electrical power to the motor when the trigger switch receives the instruction. The power supplying unit changes an amount of the driving electrical power based on the load detected by the load detecting unit. | 7 |
GOVERNMENT LICENSE RIGHTS
This invention was made with government support and the U.S. Government has certain rights in this invention and may have the right in limited circumstances to require the patent owner to license others a reasonable terms as provided for by the terms of Subcontract SK70A0430M awarded by the Department of Defense.
This is a continuation of application Ser. No. 07/867,122, filed on Apr. 10, 1992 now abandoned.
This invention relates to a signal processing circuit and, more particularly, a signal processing circuit used for signal averaging and suppression of unipolar transient effects.
BACKGROUND OF THE INVENTION
The analog circuits embodied in semiconductor material are typically used for computation or sampling. When used for sampling, a number of undesirable effects are often seen, including gamma or unipolar transient effects. Typically such analog circuits are used as averagers or integraters where the incoming signal is sampled over a period of time. Analog sampling circuits responding as peak detectors often suffer from noise associated with signals which are corrupted with negative polarity gamma or other unipolar transient voltage shifts.
The prior art analog signal processing circuits could not perform the dual tasks of analog signal averaging and gamma suppression, also known as transient suppression. Prior art circuits have employed averaging techniques that require a substantial number of components. A prior art signal averager designed for 64 averages would require approximately 50 times the area of the present invention. The prior art's need for capacitors dictates large area usage. Also prior art signal averaging circuits are limited in the number of averages attained due to dynamic range considerations.
The circuit of the invention responds to small signals and works as a peak detector. The circuit of the invention differs from prior art peak detectors because it averages small signals.
It is therefore the motivation of the invention to provide a peak detector that averages small signals and requires small amounts of silicon real estate.
SUMMARY OF THE INVENTION
The invention provides a signal processing circuit that can be used for analog averaging or the suppression of gamma or other undesirable unipolar transient effects of analog signals. By employing a switching transistor, a signal can be sampled for a specified time. Signal current is sent to an integrating capacitor. The output of the invention increases the total source potential of an input transistor to a predetermined threshold value. The invention provides different effects depending on the behavior of the input transistor. The input signal can be sampled a number of times providing a final output after the predetermined time period. The final output voltage will be representative of the average of the signal samples taken. The circuit can be reset.
One object of the invention is to provide an improved analog processing circuit that performs analog signal averaging.
It is another object of the invention to provide an improved signal processing circuit useful for suppression of unipolar transient effects of analog signals.
It is yet another object of the invention to provide an improved circuit that requires fewer and smaller components.
It is yet another object of the invention to provide an improved signal processing circuit that can be realizable in a smaller silicon area.
It is yet another object of the invention to provide an improved signal processing circuit that does analog signal averaging and can be realized in a compact size.
It is a further object of the invention to provide an improved signal processing circuit having gamma suppression capabilities in staring infrared focal planes.
It is yet another object of the invention to provide an improved signal processing circuit that requires less power.
It is a further object of the invention to provide an improved circuit that performs as a peak detector.
It is yet a further object of the invention to provide an improved circuit that averages to small signals.
It is a further object of the invention to provide an improved long wave length infrared focal plane array signal processing circuit.
Other objects, features and advantages of the present invention will become apparent to those skilled in the art through the description of the preferred embodiment, claims and drawings herein where like numerals refer to like elements.
BRIEF DESCRIPTION OF THE DRAWINGS
To illustrate the invention, a preferred embodiment of this invention will be described hereinafter with reference to the accompanying drawings. The preferred embodiment concerns a signal processing circuit to perform signal averaging and suppression of unipolar transient effects.
FIG. 1 is a circuit diagram of one embodiment of the method of the invention.
FIG. 2 is a graph of the operating voltages of the circuit of the invention.
FIG. 3 is a signal level diagram showing the relationship between signals of the invention.
FIG. 4 is a diagram of the relationship of the noise versus samples.
FIG. 5 shows a diagram showing the phase relationship between signals of the invention.
FIG. 6 is another alternative embodiment of the invention utilizing a sample and hold.
FIG. 7 is a schematic drawing of one alternative of the embodiment of the invention using complementary circuit inversion.
FIG. 8A shows a compact signal averager alternate embodiment.
FIG. 8B shows the relationship of two control signals.
FIGS. 9A and 9B show a complementary version of one alternative embodiment of the invention.
DESCRIPTION OF THE PREFERRED EMBODIMENT
FIG. 1 shows a schematic representation of one embodiment of the signal processing circuit 100 of the invention. A first electrical signal V IN 10 is connected to the gate of field effect transistor 20. A second electrical signal V DD is connected to the drain of field effect transistor 20. The source of transistor M1 20 is connected in series to the drain of a second transistor M2 40. The gate of transistor M2 40 is attached to a third electrical signal, input signal 30 φ 1 . The source of transistor M2 40 is connected to one side of C1 capacitor 50. The other side of capacitor C1 50 is grounded. A third transistor M3 70 has a source which is grounded. The gate of the third transistor M3 70 is attached to input signal φ RS 80 and the drain of transistor M3 70 is further attached to V OUT which is also attached to the transistor M2 40 side of capacitor C1 50.
Now referring to FIG. 2 which shows the control signals used to operate the circuit of FIG. 1. φ RS 80 is driven following the voltage curve φ RS reset 110. φ RS reset 110 provides the signal used to reset the sampling circuit 100. φ 1 30 is driven following the voltage curve φ 1 sample 120. φ 1 sample 120 provides the signal used to sample the input V IN 10.
Circuit 100 will now be explained as to its operation in the preferred embodiment of the invention with reference to FIGS. 1 and 2. The first electrical signal V IN 10 is a constant signal with guassian noise distribution. The circuit can be initialized by discharging capacitor C1 50 to ground through transistor M3 70, line φ RS provides the control. Transistor M3 70 is turned on for time t 1 by applying a signal φ RS 80 to the gate of transistor M3 70.
The signal V IN 10 is sampled for time t 2 by switching transistor M2 40 on, allowing current to integrate onto capacitor C 1 50. The output signal V OUT increases until the source potential of transistor M1 20 rises to within approximately one threshold voltage from the first electrical signal V IN 10. At this point the sub-threshold behavior of the first transistor M1 20 determines the circuit behavior.
The first electrical signal V IN 10 is then sampled N-1 additional times, providing a final output after the Nth sample where N is any positive integer. The final output voltage V OUT 60 is representative of the average of the N samples. Following reinitialization by resetting output signal V OUT 60, the above procedure can be repeated.
The circuit of the FIG. 1 responds to small signals and functions as a peak detector. The circuit of the invention differs from prior art peak detectors because it averages small signals as well as behaves as a peak detector. The invention for smaller signals, averages, close to the optimum. The circuit of the invention is particularly useful for making long wave length focal plane arrays where there is a huge mismatch between the amount of current that the electronics has to deal with and the space available to do it in. The space factors are about 1000 to 1. The amount of current you can reasonably handle per unit area of silicon is about 1/1000 of what actually is coming in with prior art methods.
The circuit of FIG. 1 is capable of averaging around 100 pulses after which the voltage on C1 50 after 100 cycles is within 10% or so of being the true average of all the input voltages over the true average of all 100 input voltages.
Transistor M2 40 acts like a switch and enables the peak detector. In the circuit of FIG. 1 the problem is typically that the signal is a function of time that starts out very small and grows bigger. So that if the peak detector is not disabled it will always tend to be the smallest signal; which is essentially zero. So the circuit needs to be disabled. The invention effectively isolates the pixel capacitor out of the circuit so it cannot charge capacitor C1 50. If φ 1 is turned off then C1 50 cannot charge, no matter what voltage V IN is at. Transistor M3 70 resets the circuit of FIG. 1 by discharging everything. FIG. 3 shows the sampling behavior of the circuit of FIG. 1. V OUT 60 is shown integrating to the signal peak as the sampling φ 1 30 turns on transistor M2 40.
Small signal circuit behavior is shown in FIG. 4 where the output RMS noise 410, as a function of the number of averages, is plotted as a percentage of the input RMS noise 420. As expected for an averager, the noise decreases proportionately to the square root of N.
When the first electrical signal V IN 10 is a constant signal with guassian noise distribution with negative unipolar transient voltage shifts, operation is similar to that described above with the exception that the circuit responds as a peak detector. The circuit suppresses the noise associated with signals which are corrupted with negative polarity gamma or other unipolar transient voltage shifts. A differential transfer curve depicting this behavior is shown in FIG. 5. Response to guassian noise is the same as in FIG. 5.
The invention has several advantages over past applications. First, it performs two tasks, signal averaging and gamma or transient suppression, using a single, compact circuit. For averaging applications, the invention requires fewer and smaller components than past circuits performing similar functions. For example, using the same CMOS process, a typical signal averager designed for 64 averages would require approximately 50 times the area, most of which is needed for capacitors. This reduction in size allows for a significant reduction in silicon die area, applications which once required two silicon die can now be accomplished with a single die.
For the present invention of FIG. 1, the number of averages, N, which can be performed is not limited by the circuit configuration; N is continuously variable from one to approximately 200. Due to dynamic range considerations, other averaging circuitry must be designed for a specific number of averages, usually limited to less than 100. Moreover, the area required for other circuitry is directly proportional to the desired number of averages, while the present circuit remains at a constant, compact size.
FIG. 6 shows an embodiment of the invention used for gamma suppression applications in staring infrared focal planes, such as staring infrared focal plane 5 this circuit can be placed within the unit cell 6 of the multiplexer circuit, allowing suppression to occur immediately after the transimpedance stage of the readout circuitry. The invention provides a single readout circuit which eliminates the need for additional signal processing of focal plane information. As a result, system complexity and cost are all reduced while circuit simplicity is enhanced. Prior art implementations require more complex circuitry with greater silicon real estate and power requirements.
FIG. 6 shows the invention providing a peak detector utilizing a discrete sample and hold circuit prior to transistor M1 390 rather than using transistor M2 312 as a sampling switch. This approach is superior to the prior art since it employs C 1 350 for both the sample and hold and integration functions, reducing circuit complexity.
In the circuit of FIG. 6, original function of transistor M2 40 shown in FIG. 1 is omitted and the signal 310 is sampled explicitly prior to the input transistor, M1 390. Operation is the same as described for the circuit of FIG. 1, however, the current through M1 is not discretely shut off.
Referring now to FIG. 7, an alternate embodiment of the invention is shown which holds an inverted signal/transient polarity. For signals of opposite polarity of those described above, the circuit in FIG. 1 can be implemented in its complementary form shown in FIG. 7.
The circuit of the invention may be used in non-gamma/transient suppression applications. In focal plane applications where the suppression of transient signal corruption is not an issue, the circuit can be implemented as a peak detector with respect to the positive signal direction. This will allow averaging of the signal noise while also providing a novel on-focal plane target detection method for fast moving targets, i.e., across pixels at a rate faster than the time necessary for N samples.
From a signal that has been contaminated with a noise spike that is bigger than the other samples the invention prevents the spike from showing up on the output.
The reset rate of the detector is the sample rate of the pixel.
Signal φ RS 80 occurs a little bit before φ 1 30. The signals are synchronous with each other but the reset occurs a little bit before the input reset. The current from the detectors can be either positive or negative which is reflected in FIG. 7 as an alternate embodiment of FIG. 1.
In one alternative application of the invention the circuit of the invention can be employed in the signal path between a detector and a multiplexer. Some detectors contain typically an array of 64×64 sensors or an array of 128×128 sensors. Each detector comprises a preamplifier and a capacitor which stores the signal from the sensor. The capacitor cannot typically be made large enough.
In general, the V IN 10 would come from the sensor capacitor. In one example embodiment of the invention the detectors are photodiodes. The current under sensor capacitor is integrated by the circuit of the invention to form an average value of the sensed signal over a time interval. The problem in the prior art is the size of the capacitor limits the time interval below an acceptable level. The peak detector allows the use of the circuit of the invention in a radiation environment where high energy pulses are prevalent. These circuits can also act like a particle detector and produce a huge current spike which increases the noise level of the whole system quite dramatically. The peak detector of the invention does not respond to these huge spikes.
Now referring to FIG. 8A which shows an embodiment of the compact signal averaging circuit of the apparatus of the invention. The signal averaging circuit of FIG. 8A employs a transistor and a capacitor in one configuration. The transistor M1 452 is provided with a gate control signal 454 which is connected to the voltage to be averaged. The transistor is also connected to a reference voltage (VDD) 462 and is also connected to capacitor C1 456. Reset transistor 460 discharges capacitor C1 456 in response to control line 464.
Now referring to FIG. 8B which shows the control reset signal 464 and the voltage in to be sampled 454 plotted as a function of time. FIG. 8B shows the periodic signal VS and the output voltage V OUT 458 which is integrating in capacitor C1 456 as each V IN sample integrates into capacitor C1 456.
Now referring to FIG. 9 which shows the compact signal averaging circuit of the invention used to implement substantially the same signal averaging method of FIG. 8A except for the polarities are reversed. Capacitor 476 is charged in response to signal V IN applied to the gate of transistor 472 while reset signal φ R maintains transistor 478 nonconducting. Signal V S effects sampling of the input signal V IN . When reset signal φ R applies a reset pulse to the gate of transistor 478, it operates to reset capacitor 476.
The invention has been described herein in considerable detail in order to comply with the Patent Statutes and to provide those skilled in the art with the information needed to apply the novel principles and to construct and use such specialized components as are required. However, it is to be understood that the invention can be carried out by specifically different equipment and devices, and that various modifications, both as to the equipment details and operating procedures, can be accomplished without departing from the scope of the invention itself. | An analog signal processing circuit used to suppress unipolar transient effects and signal averaging. Two transistors and one capacitor are provided in series to sample and condition an input signal. An additional transistor is provided in parallel to the capacitor to provide further signal processing capabilities. The circuit can function as an analog signal average, suppressing unipolar transient effects and as a peak detector while using a conservative amount of fabrication material and can be operated with low power. | 6 |
FIELD OF THE INVENTION
[0001] The present invention relates generally to a device useful for wound healing, and more particularly to a magnetic device that draws wound edges in proximity to each other.
BACKGROUND OF THE INVENTION
[0002] Wounds usually occur when there is trauma to the skin and underlying tissue. Types of trauma include lacerations, abrasions, incisions, punctures, and penetrations. After trauma, the wound begins to heal in a complex series of biochemical processes occurring is several wound-healing phases. The phases of healing are often categorized into a hemostasis phase, an inflammatory phase, a proliferative phase and a remodeling phase. In hemostasis, active bleeding is controlled by clotting. In the inflammatory phase, pathogens are removed by the body away from the wounded area, and biological factors are released (which later cause the division of cells involved in the proliferative phase). In the proliferative phase, new blood vessels are formed and wound contraction occurs. Also in the proliferative phase, epithelial cells cover the wound, providing an area of growth for new tissue. During contraction, the wound is made smaller by myofibroblasts attaching to the wound edges, and finally, during the remodeling phase, collagen fibers are realigned along tension lines formed during the earlier phases of healing.
[0003] Not only is the process of wound healing complex, but it is also fragile, since many factors can lead to a disruption of proper wound healing, including re-injury of the tissue, bacterial infection, and physical stress on the damaged tissue. A variety of devices and methods have been used to aid in the wound healing process. These devices and methods are generally divided into one of three types: primary intention, secondary intention, and tertiary intention. The primary intention devices and methods bring the edges of the wounds together, so that the edges are reapproximated. Reapproximation helps to minimize scarring, and increases the speed at which wound contraction and healing occur. Examples of primary intention devices and methods include the use sutures, staples, tape, glue, and hooks. Primary intention techniques to heal wounds are the most common techniques used by practitioners. While not as commonly used, secondary intention devices and methods include first allowing the wound granulate without closing the wound, and thereafter packing and draining the wound several times to remove debris. Still less common are tertiary intension devices and methods, which delay the closure of the wound even longer, so that the practitioner can close the wound at a later time. Tissue grafting is an example of a tertiary method for wound healing.
[0004] Wound edge reapproximation is key to wound healing. If the edges of the wound are not immediately reapproximated soon after injury, healing may be delayed. This delay in healing may leads to scarring and infection. While in some circumstances a delay is advantageous, practitioners generally want to close an open wound as soon as possible. Therefore, quick and easy to use devices and methods are needed to reapproximate the wound edges.
[0005] The traditional method to reapproximate wound edges is by sutures, where a practitioner stitches a threading material to connect opposing sides of a wound. Sutures and suturing techniques are well known in the prior art, such as described in U.S. Pat. No. 8,267,959. Other devices and methods to reapproximate wound edges include hooking devices, such as the hook closure device in in U.S. patent application Ser. No. 13/266,825, where a band placed over a wound has a multiplicity of hook elements that engage a mesh on the opposing side of a wound.
[0006] The use of adhesive strips is another method to aid in wound closure. In U.S. Pat. No. 4,825,866, adhesive strips are placed on opposite sides of a wound and drawn together to reapproximate the wound edges. Stapling and clipping the edges of wound are other techniques to reapproximate wound edges, as described in U.S. Pat. No. 7,556,632.
[0007] The use of magnets to reapproximate wound edges has also previously been described. U.S. patent application Ser. Nos. 10/512,964 and 12/721,651 are two applications that have described tissue joining devices comprising interconnecting components where the magnetic components are attracted to each other and draw tissue together using magnetism.
[0008] Other compositions and methods to reapproximate wound edges include the use of medical adhesives, such as cyanoacrylate glues that provide for very tight, high-strength closure of wounds without the need for the physical closure accomplished with sutures. However, cyanoacrylate based glues have been associated with the formation of toxic byproducts, and even non-toxic versions are generally only useful for smaller, shallow lacerations in low-tension areas. These adhesives can be very unforgiving if the practitioner needs to remove the glue. Another disadvantage of using glues for wound closure is that leakage of glues can cause serious ramifications, especially if the adhesives are toxic and the wounds are near sensitive anatomical structures, such as the eye. Still another disadvantage is that adhesives can trap pathogens and other particles within the wound.
[0009] Each type of wound closure device and technique has advantages and disadvantages. Sutures pose the risk of needle stick injury to the patient, as well as to health care professions. The process of suturing also can take a substantial amount of time depending on the size of the wound. Using staples for wound closure is more rapid than suturing, however, unlike sutures, which may be absorbed by the body, staples usually have to be removed by a special tool. Sutures and staples also require applying local anesthesia, which could be painful and toxic to the patient. Furthermore, if the practitioner needs to enter the wound area, the sutures or staples need to be cut or removed, and both sutures and staples can lead to scarring.
[0010] Some of the more complex wound closure devices that reduce some of these disadvantages have many individual parts, are difficult to apply, or are expensive. Accordingly, it would be advantageous to make available a novel wound closure device that reduces these stated disadvantages.
SUMMARY OF THE INVENTION
[0011] The present invention relates to a wound closure device and methods of reapproximating wound edges, which lead to improved wound healing. It is an object of the present invention to provide a magnetic wound closure device, such that when two of the magnetic wound closure devices are attached to skin on opposites sides of a wound, the magnets attract each other, thereby pulling together the edges of the wound. There are several advantages to the described invention, including: 1) placement of the device on a patient is faster than using staples or sutures, 2) no need to wait for an anesthetic, less trauma, 3) no painful injections are needed, 4) inspection of the wound is simple because the device is easily removable, and 5) the device can be easily manufactured in a variety of sizes and shapes that accommodate various wound sizes.
[0012] The magnetic wound closure device is used as a pair of magnetic wound closure devices aligned in opposite polarity with respect to each other so that the magnetic edges of each device attracts the polar opposite edge of another device. In one embodiment, each of the magnetic wound closure devices has a magnet, an insulation layer adjacent to the magnet, an absorbent layer adjacent to the insulation layer, a polymer layer that has a plurality of holes capable of draining wound secretions to and from the absorbent layer, and an adhesive layer adjacent to the bottom surface of the polymer layer. The adhesive layer allows the magnetic wound closure device to adhere to the surface of the skin of a patient. When placed on the patient, the interior edges of each magnet are oriented in opposite polarity to each other, and on opposite sides of a wound (with the wound situated below and between two magnetic closure devices). Since the two magnetic wound closure devices are attached to the skin of the patient via an adhesive layer, when the two magnetic wound closure devices draw toward each other due to the magnetic forces between them, the skin edges surrounding the wound are drawn toward each other, thus making the wound opening smaller, thereby allowing the wound to heal more quickly.
[0013] In another embodiment, the magnetic wound closure device is enclosed within a polymer housing, which houses the magnet, insulation layer, and absorbent layer, and is contiguous with the polymer layer adjacent to the absorbent layer.
[0014] In yet another embodiment, the polymer layer and the polymer housing is a silicone polymer layer and a silicone polymer housing, respectively.
[0015] In yet another embodiment, the magnet is made from a plurality of segmented magnets capable of vertical and horizontal flexing. The plurality of segmented magnets allows the practitioner to curve and shape the device to the shape of the wound edges.
[0016] In yet another embodiment, the magnetic wound closure device has a removable adhesive cover that protects the adhesive layer. By covering the adhesive layer with the removable adhesive cover, the adhesive layer is protected until needed, and conserves the adhesive properties of the adhesive layer until the practitioner removes (such as by peeling off) the adhesive cover from the adhesive layer.
[0017] In still another embodiment of the invention, the wound closure device has a directional indicator marker for determining the correct directional alignment of the wound closure device with respect to the wound opening. In one embodiment of the directional indicators, the directional indicators are arrows pointing toward the edge of the magnetic device closest to the wound, such that when one magnetic device is placed on one edge of a wound with directional indicators pointing toward the wound, and a second magnetic device is placed on the opposite edge of the wound with directional indicators pointing toward the opposite wound edge, the pair of magnetic wound closure devices are oriented such that they attract, instead of repel each other. The directional indicators may point to the north pole magnetic end, the south pole magnetic end, and/or be color coded to help the practitioner determine the proper orientation of two magnetic wound closure devices with respect to each other and the wound.
[0018] It is another object of the invention to provide a method of reapproximating wound edges. The steps involve: adhering a first magnetic wound closure device on a patient substantially near a first edge of a wound, orienting a second wound closure device on a patient such that the inner edge of the second wound closure device is aligned in opposite polarity with the inner edge of the first wound closure device along a second (opposite) side of the same wound, and adhering the second wound closure device on the patient substantially near the second side of the wound. The inner edge of the first wound closure device and the inner edge of the second wound closure device attract each other due to aligning the magnetic wound closure devices in opposite polarity across a patient's wound.
[0019] In another embodiment of the method, adhering the magnetic wound closure devices on the patient is characterized as rolling the magnetic wound closure devices on the patient.
[0020] In another embodiment of the method, the user removes the adhesive cover from the wound closure device before the wound closure devices are placed on the patient.
BRIEF DESCRIPTION OF THE DRAWINGS
[0021] These and other features and advantages of the present invention will become appreciated, as the same becomes better understood with reference to the specification, claims and drawings herein:
[0022] FIG. 1 is a perspective view of an embodiment of a wound closure device illustrating the magnet layer, insulation layer, absorbent layer, polymer layer, adhesive layer, and removable cover.
[0023] FIG. 2 is a cross sectional view of FIG. 1 .
[0024] FIG. 3 is a top cross sectional view of a segmented magnet that can be used as the magnetic layer in the magnetic wound closure device.
[0025] FIG. 4 is a perspective exemplary view of one magnetic wound closure device being placed one side of a patient's wound.
[0026] FIG. 5 is a perspective exemplary view of two magnetic wound closure devices, each one placed on an opposite side of a wound, and oriented in opposite polarity to each other such that the two magnetic wound closure devices attract each other, thereby reapproximating wound edges.
DETAILED DESCRIPTION OF THE INVENTION
[0027] The invention now will be described more fully hereinafter with reference to the accompanying drawings, in which embodiments of the invention are shown. This invention may, however, be embodied in many different forms and should not be construed as limited to the embodiments set forth herein. Rather, these embodiments are provided so that this disclosure will be thorough and complete, and will fully convey the scope of the invention to those skilled in the art.
[0028] It will be understood that when an element is referred to as being “on” another element, it can be directly on the other element or intervening elements may be present therebetween. As used herein, the term “and/or” includes any and all combinations of one or more of the associated listed items.
[0029] It will be understood that, although the terms first, second, third etc. may be used herein to describe various elements, components, regions, layers and/or sections, these elements, components, regions, layers and/or sections should not be limited by these terms. These terms are only used to distinguish one element, component, region, layer or section from another element, component, region, layer or section.
[0030] As used herein, the singular forms “a,” “an,” and “the,” are intended to include the plural forms as well, unless the context clearly indicates otherwise. It will be further understood that the terms “comprises” and/or “comprising,” “includes” and/or “including,” and “have” and/or “having,” when used in this specification, specify the presence of stated features, regions, integers, steps, operations, elements, and/or components, but do not preclude the presence or addition of one or more other features, regions, integers, steps, operations, elements, components, and/or groups thereof.
[0031] Furthermore, relative terms, such as “lower” or “bottom,” and “upper” or “top,” and “inner” or “outer,” may be used herein to describe one element's relationship to another elements as illustrated in the Figures. It will be understood that relative terms are intended to encompass different orientations of the device in addition to the orientation depicted in the Figures.
[0032] Unless otherwise defined, all terms used herein have the same meaning as commonly understood by one of ordinary skill in the art to which this invention belongs. It will be further understood that terms, such as those defined in commonly used dictionaries, should be interpreted as having a meaning that is consistent with their meaning in the context of the relevant art and the present disclosure, and will not be interpreted in an idealized or overly formal sense unless expressly so defined herein.
[0033] Exemplary embodiments of the present invention are described herein with reference to idealized embodiments of the present invention. As such, variations from the shapes of the illustrations as a result, for example, of manufacturing techniques and/or tolerances, are to be expected. Thus, embodiments of the present invention should not be construed as limited to the particular shapes of regions illustrated herein but are to include deviations in shapes that result, for example, from manufacturing.
[0034] A wound closure device is provided for closing wounds without sutures. FIG. 1 and FIG. 2 depict one embodiment of a wound closure device 10 in perspective view and cross-sectional view, respectively. The wound closure device 10 , (illustrated as a first and second elongated strip 11 , 40 in FIG. 4 and FIG. 5 ) has a polymer enclosure 12 . The enclosure 12 may be made of any one of number of polymers, but in a preferred embodiment is a silicone enclosure 12 . Other materials for an enclosure may be made from natural or synthetic polymers including rubber, neoprene, polyvinyl chloride, polyvinyl butyral, polystyrene, polyethylene, polypropylene, nylon, polyacrylonitrile. Within the enclosure 12 is a magnet 14 , which may be a single magnet or a segmented magnet (as illustrated in FIG. 3 as 14 a and 14 b ). The magnet 14 may be made from a number of materials, such as ferromagnetic materials, or rare-earth elements, such as magnets made from alloys of neodymium, iron and boron. The advantage of rare-earth magnets, such as neodymium magnets is that their crystalline structures have very high magnetic anisotropy and can retain high magnetic moments in the solid state.
[0035] In a preferred embodiment, the magnet is a flexible magnet that is rolled or extruded in a magnetic film, and then cut to size into a magnetic sheet or strip. In one composition of a magnet useful for wound closure comprises NeFeB magnetic power, chlorinated polyethylene (CPE), and an annexing agent such as soybean oil.
[0036] In a preferred embodiment the magnet in the device is comprised of approximately 90.5% NdFeB powder, 8.5% CPE, and 1% annexing agent. In one embodiment, the NdFeB powder may be comprised of approximately 31.0-31.8% PrNd, approximately 64-66.5% Fe, approximately 1.00-1.03% B, approximately 1.5-1.8% Dy, approximately 0.5-0.8% Co, approximately 0-0.25% Nb, and approximately 0.0-0.2% Al. Deviations from the percentages above that also allow for a strong but flexible magnet are allowed and known by persons having ordinary skill in the art.
[0037] Adjacent and above the magnet 14 is an insulation layer 16 . The insulation layer is a vapor barrier protective layer that is waterproof and prevents moist secretions from getting absorbed by the magnet 14 . If moisture contacts the magnet 14 , the magnet may rust, and the magnetic material may leak into the absorbent layer 18 . The insulating layer 16 may be made from any number of waterproof materials known in the art, such as nylon or other waterproof polymers.
[0038] Adjacent to the insulation layer 16 is an absorbent layer 18 , which can absorb wound secretions. The absorbent layer 16 may be made from a variety of absorbent materials, including sterile gauze sponge, cotton, cellulose fibers, wool, silk, linen, acetate, nylon, and polyester materials. Adjacent and under the absorbent layer 18 is a polymer layer 20 , which has a plurality of holes 22 that allow for draining of potential build-up of secretions from a wound. The plurality of holes (or pores) 22 create a passageway from the absorbent layer 18 through the polymer layer 20 , through the adhesive layer 24 , to the skin of the patient. Capillary action allows the absorbent layer 18 to absorb potential secretions from the wound via the capillary properties of the absorbent layer 18 , and then diffuse the secretions via plurality of holes 22 in the device. There may also be a plurality of side holes 23 on the side surfaces of the polymer enclosure 12 that allow fluids not to only drain potential buildup to and from the surface of the skin, but drain fluids out of the sides of the device 10 as illustrated in FIG. 1 and FIG. 2 .
[0039] The polymer layer 20 on the bottom of the device 10 may be contiguous with the polymer enclosure 12 that houses the magnet 14 , insulation layer 16 , and absorbent layer 18 . On the bottom surface of the polymer layer 20 is an adhesive surface layer 24 . The adhesive surface 24 allows the magnetic wound closure device 10 to adhere to the skin of a patient, adjacent to a wound. The adhesive layer 24 may be made from any one of a number of adhesive compositions, including: reusable adhesives, pressure sensitive adhesives, contact adhesives, resins, epoxies, polyurethane, cyanoacrylate (CA), polymers, acrylic-based adhesives that cure under ultraviolet (UV) light, silicone based adhesives, and polyolefinic polymers. Protecting the adhesive layer 24 , is a removable cover 26 , such as peel-off tape, that protects the adhesive layer 24 from the environment, and prevents the adhesive from sticking to any surface until the cover 26 is removed. The practitioner removes this adhesive cover 26 before placing the device 10 on the patient's skin.
[0040] FIG. 3 illustrates one embodiment of the magnet 14 showing segmented magnet portions 14 a , 14 b , in cross sectional view. Each individual magnetic segment 14 a , 14 b is adjacent to a different segment within the polymer enclosure 12 (the non-magnetic elements within the polymer enclosure, illustrated in FIGS. 1 and 2 , are not shown in FIG. 3 , but may exist on one or more embodiments previously described and illustrated). The polymer enclosure 12 is comprised of a flexible polymer that allows for the polymer to flex when the magnet 14 within the polymer bends. The inclusion of plasticizers within the polymer composition of the enclosure 12 lowers the glass transition temperature (T g ) of the polymer, therefore allowing device 10 to flex when the magnet 14 within the polymer enclosure 12 flexes. Plasticizers are commonly known and used in the art, and may included phthalate ester plasticizers commonly used in medical devices such as: dicarboxylic/triboxylic ester-based plasticizers, including Bis (2-ethylhexyl) phthalate, Di-n-butyl phthalate, or Diisooctyl phthalate. The segmented magnet 14 a , 14 b has a spacer region 50 (which may be a void to allow movement) between the each magnet segment 14 a , 14 b , which allows the segments 14 a , 14 b of the magnet 14 to flex horizontally and vertically. This flexing is useful for easy placement of the device 10 on a patient's skin. One advantage of a segmented magnet 14 a , 14 b , having greater flexibility compared to a non-segmented magnet 14 is that the segmentation allows the practitioner to align the device 10 along a non-linear wound (i.e., a wound that traverses a curved surface on a patient, such as the curved features of an arm, or a leg), since the segments 14 a , 14 b combined with the voids 50 between each segment 14 a , 14 b , can curve to match the shape of non-linear wound. Shaping the device 10 to match the wound is advantageous because a pair of devices 10 can be placed in closer proximity to each other across a wound that is irregularly shaped if each device 10 is capable of flexing to match the shape of the wound.
[0041] FIG. 4 illustrates the placement of a first strip 11 of the magnetic wound closure device 10 on an arm 42 of a patient, adjacent to a wound 28 . The strip 11 has a directional indicator 30 , here illustrated as plurality of arrows pointing toward a first edge 32 of the wound 28 . The inner edge 44 of the first strip 11 is placed across from the inner edge 46 of a second strip 40 , which also has directional indictors 48 pointing toward a second edge 33 of the wound 28 . When using two strips 11 , 40 , the directional indicators 30 of the first strip 11 , and the directional indicators 48 of a second strip 48 are oriented such that they point toward each other, thereby ensuring that the inner edges 44 , 46 of each strip 11 , 40 are magnetically polar opposites of each, and thus attract each other, thereby drawing in the edges 32 , 33 of the wound 28 together. If the strips 11 , 40 are not oriented correctly (i.e. the north pole edge of the first strip 11 across from the the north pole of the second strip 40 ), then when the strips 11 , 40 are placed on opposite sides of a wound, the strips 11 , 40 would repel each other instead of attract each other, thus hindering wound recover.
[0042] Since the strips 11 , 40 are secured to the patient's skin via an adhesive layer 24 , when the strips 11 , 40 attract each other, the edges of the wound 28 are drawn together as the strips 11 , 40 are magnetically drawn together. The strips 11 , 40 can easily be applied by a practitioner, peeled off the patient if required, and reapplied if necessary. Since no sutures or staples are used when applying the strips 11 , 40 , the strips 11 , 40 are advantageous for emergency situations when medical personnel are overloaded, or even in non-emergency situations for use with young children who would be more apprehensive regarding traditional wound closure devices and methods. The strips 11 , 40 also do not require costly biohazard disposal, and cause less trauma. The strips 11 , 40 can be used not only on human patients, but animals as well.
[0043] The dimensions of the strips 11 , 40 can be of any length, but preferable between 3 cm and 10 cm in length, and 1 cm and 3 cm in width. Preferably, the height of the each magnetic wound closure strip 11 , 40 is between 0.5 mm and 5 mm, and preferably approximately 1 mm in height. A thin strip 11 , 40 , allows each strip 11 , 40 to be flexible, and to lay substantially flat on the patient's skin. This is advantageous because flat strips 11 , 40 prevent catching or snagging on clothing or other objects. In another preferred embodiment, the dimensions of the magnetic wound closure strips 10 , 40 are approximately 4 cm in length, 2 cm in width, and 1 mm in height.
[0044] Each component of the strips 11 , 40 can have dimensions that accommodate the size of the patient and size of the wound. In one embodiment, the magnet 14 within each strip 11 , 40 has a height of approximately 0.04 cm, a length of approximately 1.6 cm and width of approximately 0.8 cm. In one embodiment, the absorbent layer 18 is approximately 0.04 cm thick, the adhesive layer 16 is approximately 0.001 cm thick, the insulation layer 18 is approximately 0.001 cm thick, and the peelable cover 26 is approximately 0.003 cm thick.
[0045] While the invention has been described in terms of exemplary embodiments, it is to be understood that the words that have been used are words of description and not of limitation. As is understood by persons of ordinary skill in the art, a variety of modifications can be made without departing from the scope of the invention defined by the following claims, which should be given their fullest, fair scope. | A wound closure device using magnets to draw skin together without using stitches. When two skin adhering magnets are placed on opposite sides of a wound in a polar opposite configuration, the magnets attract each other, thus drawing the skin underneath the magnets together. Each device has a magnet, an insulation layer that separates the magnet from an absorbent layer that absorbs wound secretions, a polymer layer having a plurality of holes that allow drainage of potential build-up secretions away from the absorbent layer, and an adhesive layer on the bottom that allows the device to adhere to the patient's skin. The device may be enclosed within a polymer casing that use flexible magnets, or a plurality of segmented magnets to help align the device along a non-linear (curved) wound. | 0 |
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